Nanjing, China
Nanjing, China

Southwest University is a comprehensive university in Chongqing, China. Wikipedia.

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Zha X.,National University of Singapore | Zha X.,Southwest University | Xia Q.,Southwest University | Adam Yuan Y.,National University of Singapore
FEBS Letters | Year: 2012

The RISC-associated Argonaute (Ago) proteins play the catalytic role for RISC-mediated gene regulation by selecting small RNAs and subsequent targeting and cleavage of complementary mRNAs. Ago Mid domains are proposed to play essential roles in small RNA sorting. Here, we report the crystal structures of Arabidopsis Ago1 Mid domain and its chimera mutant with part of Ago1 replaced by Ago4. The structures demonstrate that a single amino insertion in the nucleotide specificity loop of AtAgo1 will change the nucleotide binding preference of AtAgo1 from "5′-U" to "5′-A". Moreover, we identify a long positively charged groove located along the "5′-end-nucleotide specificity loop" and occupied by several sulfate ions with the distance of 9-11 Å distance, indicating a putative mRNA target binding groove. © 2012 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.

Xie L.,Southwest University | Zeng J.,Southwest University | Luo H.,Southwest University | Pan W.,Shanghai University | Xie J.,Southwest University
Critical Reviews in Eukaryotic Gene Expression | Year: 2014

The GCN5-related N-acetyltransferase (GNAT) superfamily of proteins, widespread in eukaryotes and prokaryotes, can utilize acyl coenzyme A (acyl CoA) to acylate respective acceptor substrates and release both CoA and the acylated products. GNATs have been shown to be involved in multiple physiological events, including bacterial drug resistance, regulation of transcription, stress reaction, and metabolic flux, etc. In the last few years, the importance of GNATs has only emerged in eukaryotes, but bacterial GNATs, particularly those of pathogens, have only recently been explored. In this review, we summarize the main members, structures, inhibitors, and activators of proteins in the GNAT family. We focus on the roles of GNATs in bacteria, particularly Mycobacterium tuberculosis GNATs. © 2014 Begell House, Inc.

Jiang Y.,Southwest University | Jiang Y.,Eawag - Swiss Federal Institute of Aquatic Science and Technology
Applied Geochemistry | Year: 2012

Sulfur isotopic compositions (δ 34S) and major ions were measured in groundwater and surface waters in order to elucidate the source(s) of elevated SO42- content in some of these waters in the Nandong Underground River System (NURS), located in an agricultural and urbanization-dominated area in SW China. The major chemical composition of analyzed groundwater and surface water from NURS was characterized by Ca-HCO 3 or Ca (Mg)-HCO 3 type in forested and grass land areas, and Ca-Cl (+NO 3+SO 4) or Ca (Mg)-Cl (+NO 3+SO 4) type in urban and agricultural areas, respectively. The anomalously high SO42- concentrations in waters collected from urban and agricultural areas indicated a likely anthropogenic origin for SO42-. The groundwater collected from forested and grass land areas was characterized by relatively low δ34S-SO42-, from -1.7‰ to +4.3‰, and low SO42- concentrations of less than 10mgL -1, consistent with an origin for SO42- in these waters from a mixture of rainfall-derived SO42- and SO42- from oxidation of bedrock sulfide. High SO42- groundwater and surface water (>20mgL -1) collected from urban areas was characterized by elevated δ34S-SO42-, from +8.3‰ to +12.1‰, compared to lower δ34S-SO42- in samples from cultivated land areas (-3.7‰ to +6.4‰), indicating that the SO42- in these two groups of waters resulted from different anthropogenic sources. The S isotopic composition of SO42- in urban areas is consistent with addition of SO42- from detergent/sewage, whilst in cultivated land areas isotope composition indicates that additional SO42- could be derived from fertilizers and/or increased oxidation of sulfide. © 2012 Elsevier Ltd.

Zhou Y.,Southwest University | Huang H.,Beijing Tuberculosis and Thoracic Tumor Research Institute | Zhou P.,Southwest University | Xie J.,Southwest University
Cellular Signalling | Year: 2012

The IclR family transcriptional factor is widespread and involves in diverse bacterial physio-pathological events, such as primary and secondary metabolism, virulence, quorum sensing, sporulation. Unlike other transcriptional factors which function as either activators or repressors, IclR can assume both role simutaneously. Its N-terminal domain possesses a helix-turn-helix DNA binding motif which can dimerize or tetramerize to bind target promoters, while the C-terminal domain is for the effector binding. The function of IclR varies with the effectors bound. . Escherichia coli transcription factor IclR is the archetype of this family, which regulates the . aceBAK operon responsible for the glyoxylate shunt. The sophisticated regulatory mechanisms underlying iclR was largely based on . E. coli iclR. Information concerning the pathogen IclR, especially those of . Mycobacterium tuberculosis is poor, and is pivotal to our understanding of its biology and development of new effective TB control measures. © 2012 Elsevier Inc..

Zhao P.W.,Beijing University of Technology | Li Z.P.,Beijing University of Technology | Li Z.P.,Southwest University | Yao J.M.,Southwest University | And 3 more authors.
Physical Review C - Nuclear Physics | Year: 2010

A new parametrization PC-PK1 for the nuclear covariant energy density functional with nonlinear point-coupling interaction is proposed by fitting to observables of 60 selected spherical nuclei, including the binding energies, charge radii, and empirical pairing gaps. The success of PC-PK1 is illustrated in the description of infinite nuclear matter and finite nuclei including the ground-state and low-lying excited states. In particular, PC-PK1 provides a good description for the isospin dependence of binding energy along either the isotopic or the isotonic chain, which makes it reliable for application in exotic nuclei. The predictive power of PC-PK1 is also illustrated for the nuclear low-lying excitation states in a five-dimensional collective Hamiltonian in which the parameters are determined by constrained calculations for triaxial shapes. © 2010 The American Physical Society.

Li Z.P.,Southwest University | Song B.Y.,Southwest University | Yao J.M.,Southwest University | Vretenar D.,University of Zagreb | And 4 more authors.
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics | Year: 2013

The evolution of quadrupole and octupole shapes in Th isotopes is studied in the framework of nuclear Density Functional Theory. Constrained energy maps and observables calculated with microscopic collective Hamiltonians indicate the occurrence of a simultaneous quantum shape phase transition between spherical and quadrupole-deformed prolate shapes, and between non-octupole and octupole-deformed shapes, as functions of the neutron number. The nucleus 224Th is closest to the critical point of a double phase transition. A microscopic mechanism of this phenomenon is discussed in terms of the evolution of single-nucleon orbitals with deformation. © 2013 Elsevier B.V.

Guo X.,Chongqing Three Gorges University | Zou X.,Southwest University | Sun M.,Chongqing Three Gorges University
Carbohydrate Polymers | Year: 2010

Polysaccharides of Phellinus igniarius have many bioactivities. In this study, response surface methodology along with Box-Behnken design based on the single-factor experiments was firstly applied to optimize the extraction conditions by its liquid-cultured mycelia. According to analysis, extraction temperature and ratio of mycelia to water significantly affected extraction yield. The optimal conditions were extraction temperature 70 °C, extraction time 1.5 h and the ratio of mycelia to water 1:6.2. Under these conditions, the maximal yield of crude intracellular polysaccharide (IPS) from mycelia was 50.39 ± 0.41 mg/g, which was agreed with model predictions. The preliminary characterization was mainly β-galactan by gas chromatograph and infrared spectrum analysis. © 2009 Elsevier Ltd. All rights reserved.

Han T.,Southwest University | Han T.,National University of Singapore | Qiu C.-W.,National University of Singapore
Journal of Optics (United Kingdom) | Year: 2016

The full control of single or even multiple physical fields has attracted intensive research attention in the past decade, thanks to the development of metamaterials and transformation optics. Significant progress has been made in vector fields (e.g., optics, electromagnetics, and acoustics), leading to a host of strikingly functional metamaterials, such as invisibility cloaks, illusion devices, concentrators, and rotators. However, metamaterials in vector fields, designed through coordinate transformation of Maxwell's equations, usually require extreme parameters and impose challenges on the actual realization. In this context, metamaterials in scalar fields (e.g., thermal and dc fields), which are mostly governed by the Laplace equation, lead to more plausible and facile implementations, since there are native insulators and excellent conductors (serving as two extreme cases). This paper therefore is particularly dedicated to reviewing the most recent advances in Laplacian metamaterials in manipulating thermal (both transient and steady states) and dc fields, separately and (or) simultaneously. We focus on the theory, design, and realization of thermal/dc functional metamaterials that can be used to control heat flux and electric current at will. We also provide an outlook toward the challenges and future directions in this fascinating area. © 2016 IOP Publishing Ltd.

Peng S.,CAS Chengdu Institute of Mountain Hazards and Environment | Peng S.,University of Chinese Academy of Sciences | Guo T.,Southwest University | Liu G.,CAS Chengdu Institute of Mountain Hazards and Environment
Soil Biology and Biochemistry | Year: 2013

Soil aggregation is a crucial soil property that affects a wide range of physical and chemical processes in soil ecosystems. Arbuscular mycorrhizal (AM) association is recognised as an important promoter of soil aggregation through the action of individual roots, mycelia and an insoluble, glue-like and hydrophobic proteinaceous substance, which is (at least partly) of AM fungi origin, named glomalin-related soil protein. Considering the increasing application of commercial AM inoculants, we addressed how the soil aggregates respond to the hyphal functions of AM inoculation in the field with a resident AM community.To this end, we introduced a new system in which the hyphae were separated by mesh and regular rotation to break the ingrowing hyphae as a control and to demonstrate the causal link between the hyphae and soil aggregates under conditions simulating natural parameters. The results showed the following: (i) the hyphal length was positively correlated with the mean weight diameter (r = 0.384, P < 0.05), geometric mean diameter (r = 0.257, 0.05 < P < 0.10) and easily extractable glomalin (r = 0.296, P < 0.05); (ii) the colonisation rate of the roots in the cores was increased by constantly severing the extraradical mycelium and (iii) the colonisation rate of the control plant roots (approx. 10%) was significantly lower compared to those inoculated with AM fungi (ranging from 34% to 54%). It was concluded that the hyphal networks of AM inoculations can promote the formation and stability of soil aggregates under conditions that closely simulate those occurring in nature. © 2012 Elsevier Ltd.

Wang X.,Southwest University | Wang T.,Southwest University | Wang T.,Chongqing University of Arts and Sciences | Chen Z.,Beijing Normal University | And 3 more authors.
Neuropsychologia | Year: 2015

Individuals differ in the ability to utilize previous conflict information to optimize current conflict resolution, which is termed the conflict adaptation effect. Previous studies have linked individual differences in conflict adaptation to distinct brain regions. However, the network-based neural mechanisms subserving the individual differences of the conflict adaptation effect have not been studied. The present study employed a psychophysiological interaction (PPI) analysis with a color-naming Stroop task to examine this issue. The main results were as follows: (1) the anterior cingulate cortex (ACC)-seeded PPI revealed the involvement of the salience network (SN) in conflict adaptation, while the posterior parietal cortex (PPC)-seeded PPI revealed the engagement of the central executive network (CEN). (2) Participants with high conflict adaptation effect showed higher intra-CEN connectivity and lower intra-SN connectivity; while those with low conflict adaptation effect showed higher intra-SN connectivity and lower intra-CEN connectivity. (3) The PPC-centered intra-CEN connectivity positively predicted the conflict adaptation effect; while the ACC-centered intra-SN connectivity had a negative correlation with this effect. In conclusion, our data demonstrated that conflict adaptation is likely supported by the CEN and the SN, providing a new perspective on studying individual differences in conflict adaptation on the basis of large-scale networks. © 2015 Elsevier Ltd.

Luo Y.,Nanyang Technological University | Luo Y.,Xinyang Normal University | Luo J.,Nanyang Technological University | Jiang J.,Nanyang Technological University | And 10 more authors.
Energy and Environmental Science | Year: 2012

Highly ordered TiO 2α-Fe 2O 3 core/shell arrays on carbon textiles (TFAs) have been fabricated by a stepwise, seed-assisted, hydrothermal approach and further investigated as the anode materials for Li-ion batteries (LIBs). This composite TFA anode exhibits superior high-rate capability and outstanding cycling performance. The specific capacity of the TFAs is much higher than that of pristine carbon textiles (CTs) and TiO 2 nanorod arrays on carbon textiles (TRAs), indicating a positive synergistic effect of the material and structural hybridization on the enhancement of the electrochemical properties. This composite nanostructure not only provides large interfacial area for lithium insertion/extraction but should also be beneficial in reducing the diffusion pathways for electronic and ionic transport, leading to the improved capacity retention on cycling even at high discharge-charge rates. It is worth emphasizing that the CT substrates also present many potential virtues for LIBs as flexible electronic devices owing to the stretchable, lightweight and biodegradable properties. The fabrication strategy presented here is facile, cost-effective, and scalable, which opens new avenues for the design of optimal composite electrode materials for high performance LIBs. This journal is © 2012 The Royal Society of Chemistry.

Zhao W.,Hefei University of Technology | Zhang Y.,Hefei University of Technology | You X.-P.,Southwest University | Zhu Z.-H.,Beijing Normal University
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2013

Measurement of pulsar timing residuals provides a direct way to detect relic gravitational waves at the frequency f∼1/yr. In this paper, we investigate the constraints on the inflationary parameters, the tensor-to-scalar ratio r, and the tensor spectral index nt, by the current and future pulsar timing arrays. We find that the Five-hundred-meter Aperture Spherical Radio Telescope in China and the planned Square Kilometre Array projects have fairly strong abilities to test the phantomlike inflationary models. If r=0.1, then Five-hundred-meter Aperture Spherical Radio Telescope could give the constraint on the spectral index nt<0.56 and Square Kilometre Array could give nt<0.32, while an observation with total time T=20 yr, pulsar noise level σw=30 ns, and monitored pulsar number n=200 could even constrain nt<0.07. These are much tighter than those inferred from the current results of the Parkes Pulsar Timing Array, European Pulsar Timing Array, and North American Nanohertz Observatory for Gravitational Waves. By studying the effects of various observational factors on the sensitivities of pulsar timing arrays, we find that compared with σw and n, the total observation time T has the most significant effect. © 2013 American Physical Society.

Ye X.,Southwest University | Ye X.,CAS Nanjing Institute of Geography and Limnology | Zhang Q.,CAS Nanjing Institute of Geography and Limnology | Liu J.,Water Research Institute of Shandong Province | And 3 more authors.
Journal of Hydrology | Year: 2013

Under the background of global climate change and local anthropogenic stresses, many regions of the world have suffered from frequent droughts and floods in recent decades. Assessing the relative effect of climate change and human activities is essential not only for understanding the mechanism of hydrological response in the catchment, but also for local water resources management as well as floods and droughts protection. The Poyang Lake catchment in the middle reaches of the Yangtze River has experienced significant changes in hydro-climatic variables and human activities during the past decades and therefore provides an excellent site for studying the hydrological impact of climate change and human activities. In this study, the characteristics of hydro-climatic changes of the Poyang Lake catchment were analyzed based on the observed data for the period 1960-2007. The relative effect of climate change and human activities was first empirically distinguished by a coupled water and energy budgets analysis, and then the result was further confirmed by a quantitative assessment. A major finding of this study is that the relative effects of climate change and human activities varied among sub-catchments as well as the whole catchment under different decades. For the whole Poyang Lake catchment, the variations of mean annual streamflow in 1970-2007 were primarily affected by climate change with reference to 1960s, while human activities played a complementary role. However, due to the intensified water utilization, the decrease of streamflow in the Fuhe River sub-catchment in 2000s was primarily affected by human activities, rather than climate change. For the catchment average water balance, quantitative assessment revealed that climate change resulted in an increased annual runoff of 75.3-261.7. mm in 1970s-2000s for the Poyang Lake catchment, accounting for 105.0-212.1% of runoff changes relative to 1960s. However, human activities should be responsible for the decreased annual runoff of 5.4-56.3. mm in the other decades, accounting for -5.0% to -112.1% of runoff changes. It is noted that the effects of human activities including soil conservation, water conservancy projects and changes in land cover might accumulate or counteract each other simultaneously, and attempts were not made in this paper to further distinguish them. © 2013 Elsevier B.V.

Liu T.-B.,Rutgers University | Subbian S.,Rutgers University | Pan W.,Shanghai University | Eugenin E.,Rutgers University | And 2 more authors.
Cell Communication and Signaling | Year: 2014

Background: Cryptococcus neoformans is the most common cause of fungal meningitis among individuals with HIV/AIDS, which is uniformly fatal without proper treatment. The underlying mechanism of disease development in the brain that leads to cryptococcal meningoencephalitis remains incompletely understood. We have previously demonstrated that inositol transporters (ITR) are required for Cryptococcus virulence. The itr1aΔ itr3cΔ double mutant of C. neoformans was attenuated for virulence in a murine model of intra-cerebral infection; demonstrating that Itr1a and Itr3c are required for full virulence during brain infection, despite a similar growth rate between the mutant and wild type strains in the infected brain. Results: To understand the immune pathology associated with infection by the itr1aΔ itr3cΔ double mutant, we investigated the molecular correlates of host immune response during mouse brain infection. We used genome-wide transcriptome shotgun sequencing (RNA-Seq) and quantitative real-time PCR (qRT-PCR) methods to examine the host gene expression profile in the infected brain. Our results show that compared to the wild type, infection of mouse brains by the mutant leads to significant activation of cellular networks/pathways associated with host protective immunity. Most of the significantly differentially expressed genes (SDEG) are part of immune cell networks such as tumor necrosis factor-alpha (TNF-α) and interferon-gamma (IFN-γ) regulon, indicating that infection by the mutant mounts a stronger host immune response compared to the wild type. Interestingly, a significant reduction in glucuronoxylomannan (GXM) secretion was observed in the itr1aΔ itr3cΔ mutant cells, indicating that inositol utilization pathways play a role in capsule production. Conclusions: Since capsule has been shown to impact the host response during Cryptococcus-host interactions, our results suggest that the reduced GXM production may contribute to the increased immune activation in the mutant-infected animals. © 2014 Liu et al.; licensee BioMed Central Ltd.

Wang Y.,Southwest University | Liu J.,Southwest University | Chen F.,Southwest University | Zhao G.,Southwest University
Journal of Agricultural and Food Chemistry | Year: 2013

Few data were available on the interactions between polyphenols and polysaccharides. The effects of the chemical structure of polyphenols on their interactions with oat β-glucan were analyzed. Ultrafiltration was applied to determine the adsorption capacities of polyphenols into oat β-glucan. Hydroxylation favored the adsorption of flavonoids with three or fewer hydroxyl groups but deteriorated those with four or more hydroxyl groups. Among flavonoid isomers, the adsorption capacities increased in the order flavonol > flvaone > flavanone > isoflavone. Glycosylation exerted complicated influences on the adsorption capacities of flavonoids into oat β-glucan. In most cases, methylation and methoxylation of phenolic acids lowered their adsorption capacities into oat β-glucan. Esterification of gallic acid weakened its adsorption capacity into oat β-glucan, whereas o-coumaric acid presented higher adsorption capacity into oat β-glucan than p-and m-coumaric acids. Galloylation improved the adsorption capacities of catechins into oat β-glucan. © 2013 American Chemical Society.

Cao M.,University of California at Riverside | Du P.,University of California at Riverside | Du P.,Peking University | Wang X.,University of California at Riverside | And 7 more authors.
Proceedings of the National Academy of Sciences of the United States of America | Year: 2014

Antiviral immunity controlled by RNA interference (RNAi) in plants and animals is thought to specifically target only viral RNAs by the virus-derived small interfering RNAs (siRNAs). Here we show that activation of antiviral RNAi in Arabidopsis plants is accompanied by the production of an abundant class of endogenous siRNAs mapped to the exon regions of more than 1,000 host genes and rRNA. These virus-Activated siRNAs (vasiRNAs) are predominantly 21 nucleotides long with an approximately equal ratio of sense and antisense strands. Genetically, vasiRNAs are distinct from the known plant endogenous siRNAs characterized to date and instead resemble viral siRNAs by requiring Dicer-like 4 and RNA-dependent RNA polymerase 1 (RDR1) for biogenesis. However, loss of EXORIBONUCLEASE4/ THYLENE-INSENSITIVE5 enhances vasiRNA biogenesis and virus resistance without altering the biogenesis of viral siRNAs. We show that vasiRNAs are active in directing widespread silencing of the target host genes and that Argonaute-2 binds to and is essential for the silencing activity of vasiRNAs. Production of vasiRNAs is readily detectable in Arabidopsis after infection by viruses from two distinct supergroups of plant RNA virus families and is targeted for inhibition by the silencing suppressor protein 2b of Cucumbermosaic virus. These findings reveal RDR1 production of Arabidopsis endogenous siRNAs and identify production of vasiRNAs to direct widespread silencing of host genes as a conserved response of plants to infection by diverse viruses. A possible function for vasiRNAs to confer broad-spectrum antiviral activity distinct to the virus-specific antiviral RNAi by viral siRNAs is discussed.

Zhou Z.,Southwest University | Guo C.,Sichuan University of Arts and Science
Automatica | Year: 2013

In this paper, the stabilization of a linear heat equation with a heat source at intermediate point is discussed applying the backstepping method. Firstly, we prove the existence of kernels in the forward and inverse transformation by some special techniques; secondly, we obtain the exponential stability with any prescribed decay rate of a closed-loop system; finally, the effectiveness of the explicit feedback stabilization controller design is illustrated with some numerical examples. © 2012 Elsevier Ltd. All rights reserved.

Hu W.,Southwest University | Guan Z.,Southwest University | Deng X.,Southwest University | Deng X.,Sichuan University of Arts and Science | He Y.-H.,Southwest University
Biochimie | Year: 2012

Papain as a sustainable and inexpensive biocatalyst was used for the first time to catalyze the Knoevenagel reactions in DMSO/water. A wide range of aromatic, hetero-aromatic and α,β-unsaturated aldehydes could react with less active methylene compounds acetylacetone and ethyl acetoacetate. The products were obtained in moderate to excellent yields with Z/E selectivities of up to 100:0. This case of biocatalytic promiscuity not only widens the application of papain to new chemical transformations, but also could be developed into a potentially valuable method for organic synthesis. © 2011 Elsevier Masson SAS. All rights reserved.

Zhang H.,Southwest University | Liu J.,Beijing Normal University | Zhang Q.,Southwest University
Cortex; a journal devoted to the study of the nervous system and behavior | Year: 2014

Inventive conceptions amount to creative ideas for designing devices that are both original and useful. The generation of inventive conceptions is a key element of the inventive process. However, neural mechanisms of the inventive process remain poorly understood. Here we employed functional feature association tasks and event-related functional magnetic resonance imaging (MRI) to investigate neural substrates for the generation of inventive conceptions. The functional MRI (fMRI) data revealed significant activations at Brodmann area (BA) 47 in the left inferior frontal gyrus and at BA 18 in the left lingual gyrus, when participants performed biological functional feature association tasks compared with non-biological functional feature association tasks. Our results suggest that the left inferior frontal gyrus (BA 47) is associated with novelty-based representations formed by the generation and selection of semantic relatedness, and the left lingual gyrus (BA 18) is involved in relevant visual imagery in processing of semantic relatedness. The findings might shed light on neural mechanisms underlying the inventive process. Copyright © 2013 Elsevier Ltd. All rights reserved.

Yang Y.,Biomedical Research Center | Zhang Z.,Biomedical Research Center | Li S.,Biomedical Research Center | Ye X.,Southwest University | And 2 more authors.
Fitoterapia | Year: 2014

Herbal medicine, especially traditional Chinese medicine and Ayurvedic medicine have played and still play an important role in fighting against various diseases. Emerging clinical studies regarding traditional Chinese medicine have provided convincing evidence for the first time to gain credibility and reputation outside China. Although synergistic therapeutic actions of herbal ingredients have been frequently reported, few reports have offered clear underlying mechanisms. This might be the main reason for the conflicting views with respect to the therapeutic efficacy of medicinal herbs. Therefore, this paper reviews the herb synergisms reported in the recent literature and discusses thoroughly the mechanisms underlying synergistic actions of herbal ingredients. The authors conducted an electronic literature search to detect articles published mainly in the last five years. Articles were included if they pertained to synergy research of ethnomedicines or the active compounds derived from them, included verification of synergy effects using modern analytical tools and molecular-biological methods. Results have revealed that the multi-component nature of medicinal herbs makes them particularly suitable for treating complex diseases and offers great potential for exhibiting synergistic actions. The mechanisms underlying synergistic therapeutic actions of herb medicines are (1): different agents may regulate either the same or different target in various pathways, and therefore cooperate in an agonistic, synergistic way; (2): regulate the enzymes and transporters that are involved in hepatic and intestinal metabolism to improve oral drug bioavailability; (3): overcome the drug resistance mechanisms of microbial and cancer cells; and (4): eliminate the adverse effects and enhance pharmacological potency of agents by "processing" or by drug-drug interaction. The exploration of synergistic mechanisms of herbal ingredients will not only help researchers to discover new phytomedicines or drug combinations but also help to avoid the possible negative synergy. Further clinical research is required for verifying these reported drug combinations and discovered synergistic mechanisms. © 2013 Elsevier B.V. All rights reserved.

Ren W.,Beijing Normal University | Ren W.,Southwest University | Zhou E.,Beijing Normal University | Fang B.,Beijing Normal University | And 4 more authors.
Angewandte Chemie - International Edition | Year: 2014

The reaction of the base-free terminal thorium imido complex [{η5-1,2,4-(Me3C)3C5H2}2Th=N(p-tolyl)] (1) with p-azidotoluene yielded irreversibly the tetraazametallacyclopentene [{η5-1,2,4-(Me3C)3C5H2}2Th{N(p-tolyl)N=N-N(p-tolyl)}] (2), whereas the bridging imido complex [{[η5-1,2,4-(Me3C)3C5H2]Th(N3)2}2{μ-N(p-tolyl)}2][(n-C4H9)4N]2 (3) was isolated from the reaction of 1 with [(n-C4H9)4N]N3. Unexpectedly, upon the treatment of 1 with 9-diazofluorene, the NN bond was cleaved, an N atom was transferred, and the η2-diazenido iminato complex [{η5-1,2,4-(Me3C)3C5H2}2Th{η2-[N=N(p-tolyl)]}{N=(9-C13H8)}] (4) was formed. In contrast, the reaction of 1 with Me3SiCHN2 gave the nitrilimido complex [{η5-1,2,4-(Me3C)3C5H2}2Th{NH(p-tolyl)}{N2CSiMe3}] (5), which slowly converted into [{η5-1,2,4-(Me3C)3C5H2}{η5:κ-N-1,2-(Me3C)2-4-CMe2(CH2NN=CHSiMe3)C5H2}Th{NH(p-tolyl)}] (6) by intramolecular C-H bond activation. The experimental results are complemented by density functional theory (DFT) studies. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Zhu X.,Queensland University of Technology | Zhang S.,Zhejiang Normal University | Jin Z.,Peking University | Zhang Z.,Southwest University | And 2 more authors.
IEEE Transactions on Knowledge and Data Engineering | Year: 2011

Missing data imputation is a key issue in learning from incomplete data. Various techniques have been developed with great successes on dealing with missing values in data sets with homogeneous attributes (their independent attributes are all either continuous or discrete). This paper studies a new setting of missing data imputation, i.e., imputing missing data in data sets with heterogeneous attributes (their independent attributes are of different types), referred to as imputing mixed-attribute data sets. Although many real applications are in this setting, there is no estimator designed for imputing mixed-attribute data sets. This paper first proposes two consistent estimators for discrete and continuous missing target values, respectively. And then, a mixture-kernel-based iterative estimator is advocated to impute mixed-attribute data sets. The proposed method is evaluated with extensive experiments compared with some typical algorithms, and the result demonstrates that the proposed approach is better than these existing imputation methods in terms of classification accuracy and root mean square error (RMSE) at different missing ratios. © 2006 IEEE.

Pang L.,Southwest University | Tian X.,Yunnan University | Pan W.,Shanghai University | Xie J.,Southwest University
Journal of Cellular Biochemistry | Year: 2013

Glycopeptidolipids (GPLs) attached to the outer surface of the greasy cell envelope, are a class of important glycolipids synthesized by several non-tuberculosis mycobacteria. The deletion or structure change of GPLs confers several phenotypical changes including colony morphology, hydrophobicity, aggregation, sliding motility, and biofilm formation. In addition, GPLs, particular serovar specific GPLs, are important immunomodulators. This review aims to summarize the advance on the structure, function and biosynthesis of mycobacterium GPLs. © 2013 Wiley Periodicals, Inc.

He Y.,Southwest University | Li W.,Beijing Tuberculosis and Thoracic Tumor Research Institute | Liao G.,Southwest University | Xie J.,Southwest University
Journal of Proteome Research | Year: 2012

The phagosome is very important to host immunity and tissue homeostasis maintenance. The destiny of the phagosome is closely associated with the outcome of the pathogen within. Most pathogens are successfully delivered to the lysosome and destroyed via the fusion of the phagosome with the lysosome. Mycobacterium tuberculosis has evolved multiple tactics to deflect the normal fusion process, such as delaying the phagosome maturation and acidification, thereby evading the immune recognition and subsequent elimination. Identification of the specific constituents of M. tuberculosis phagosome and the underlying signaling pathways are pivotal to define the key molecular features of this process and better targets to control this recalcitrant pathogen. Proteomic profiling is a comprehensive approach to define the protein inventory. In this review, currently available mycobacteria-containing phagosome proteome data were compiled. Ten putative evolutionarily conserved phagosome proteins were summarized. Unique proteins of the M. tuberculosis-containing phagosome proteome were compiled via comparison with other phagosomes, especially the inert latex bead phagosome. Signaling events associated with these unique proteins, such as Rab GTPase and PI3P, were also found and discussed. The data will facilitate better characterization of the M. tuberculosis specific phagosome constituents and involved signaling, and host-derived targets for better tuberculosis control. © 2012 American Chemical Society.

Liu C.,Southwest University | Ma J.,Southwest University | Gan X.,Yibin University | Li R.,Southwest University | Wang J.,Southwest University
Composites Science and Technology | Year: 2012

Three novel organic-inorganic hybrid molecules, layered zirconium phosphates or phosphonates, were synthesized. To study the effects of organic chain length of them on the structure and properties of polymer nanocomposites, the polyurethane/α-zirconium phosphate (PU/ZrP), polyurethane/zirconium 2-aminoethylphosphonate (PU/ZrAEP) and polyurethane/zirconium 2-(2-(2-(2-aminoethylamino)ethylamino)ethylamino) ethylphosphonate (PU/Zr(AE) 4P) nanocomposites were prepared, and characterized by Fourier Transform Infrared (FT-IR) spectroscopy, wide-angle X-ray diffraction (XRD), transmission electron microscopy (TEM), thermal gravimetric analysis (TGA), differential scanning calorimetry (DSC) and tensile testing. It was revealed that morphological, mechanical, and thermal properties of these nanocomposites were strongly dependent on the organic chain length of the layered zirconium phosphonates. The results showed that the fillers with longer chain length exhibited better dispersion in the PU matrix. As expected, the mechanical properties and water resistance were improved with the increasing of organic chain length of fillers, which attributed to better interfacial adhesion between fillers and PU matrix. © 2012 Elsevier Ltd.

Jiang Y.,Southwest University | Jiang Y.,Eawag - Swiss Federal Institute of Aquatic Science and Technology | Hu Y.,Southwest University | Schirmer M.,Eawag - Swiss Federal Institute of Aquatic Science and Technology
Journal of Hydrology | Year: 2013

Variations in temperature, photosynthesis and respiration can force daily variations in pH, DO and DIC in surface water, potentially driving calcite precipitation or dissolution of calcium carbonate. Diel cycles of hydrochemistry and δ13CDIC were measured at high time-resolution (1h) to assess the relative magnitudes of biological and geochemical controls on carbonate chemistry and carbon cycling in a spring-fed pool with flourishing submerged plants in Chongqing, SW China under sunny weather. Results show that there were no diurnal variations in the physical and chemical parameters of the Shuifang spring water. However, during the daytime periods, SC, Ca2+, alkalinity, NO3- and pCO2 in the pool water decreased to less than those in the spring water, while pH, DO and δ13CDIC in the pool water became greater than those in the spring water. Conversely, during nighttime periods, pool water SC, Ca2+, alkalinity, NO3- and pCO2 returned to or even became greater than the spring water, while pH, DO and δ13CDIC decreased to less than the spring water. This work shows that photosynthesis and respiration of subaquatic communities are the dominant processes influencing the observed diel variations of hydrochemistry in karst spring-fed pool water. During the daytime, a simultaneous increase of δ13CDIC and DO, and decrease in DIC indicates that photosynthesis was the primary control on hydrochemistry of the pool water. Conversely, the water remained saturated with respect to calcite (SIc ranging from 0.04 to 0.15) and δ13CDIC values decreased at nighttime, indicating that respiration of the subaquatic community had a dominant influence over calcite dissolution and outgassing in the pool water. The total amount of DIC loss was estimated to be about 110,785mmol/day which represented about 1.33kgC/day. More specifically, the amount of DIC loss through carbonate precipitation was about 38,775mmol/day (0.47kg C/day), whereas photosynthetic uptake was about 60,700mmol/day (0.86kg C/day) in the pool water. On one hand, the loss of C through consumption of CO2 during carbonate precipitation was balanced by carbonate dissolution. On the other hand, the loss of C by photosynthetic uptake was diverted into organic C and constitutes a relatively long-term natural carbon sink in the karst system. In addition, the diurnal variations of NO3- and pH in the pool water, caused by photosynthesis and respiration, indicated that biogeochemical processes impact water quality on a daily timescale. © 2012 Elsevier B.V.

Zhu W.-Z.,CAS Chengdu Institute of Mountain Hazards and Environment | Xiang J.-S.,Sichuan Agricultural University | Wang S.-G.,Southwest University | Li M.-H.,Swiss Federal Institute of forest | Li M.-H.,CAS Shenyang Institute of Applied Ecology
Forest Ecology and Management | Year: 2012

Resprouting is the main regeneration mechanism of most Quercus species after severe disturbance such as fire or coppicing. Yet little is known about the relationships between the amounts of resources stored in the roots and resprouting ability when the total aboveground part of plants/trees was fully removed or destroyed, and about the resprouting ability in relation to increasing elevation associated with decreasing site productivity. The present study investigated the non-structural carbohydrate (NSC) concentrations and its pool size in roots of Quercus aquifolioides clumps grown at 3000. m, 3500. m, and 3950. m a.s.l. on Zheduo Mt., southwestern China, to test two competing hypotheses that (1) decreases in net primary productivity and growing season length with increasing elevation result in less allocation to storage of belowground NSC reserves, so that after coppicing, shrubs at higher elevations produce fewer resprouts and less total biomass than those at lower elevations, vs. (2) the shrubs growing at high-elevation sites with low-productivity produce more resprouts and biomass than those at low-elevation sites after coppicing, as it is expected that resprouting is favored in low-productivity environments. Our results indicated that early resprouting of Q. aquifolioides shrubs after coppicing is largely determined by the initial carbohydrate pool but not by the carbohydrate concentrations in roots. The large resprouting vigor of this species may be mainly ascribed to its large ratios of root to shoot biomass or root NSC pool to shoot NSC pool. The resprouting vigor of clumps decreased significantly with increasing elevation, which corresponds to significant decreases in the root biomass or root NSC pool size per clump with increasing elevation. Resprouts self-thinned more early and rapidly in clumps at lower elevations than at higher elevations, which may be mainly resulted from competition occurred more early in the more productive sites at lower elevations compared to higher elevations. Our results support the 1st but not the 2nd hypothesis. The present study has important implications for resources storage dealing with ecophysiology-based management strategy of coppicing woodland across scales. © 2012 Elsevier B.V.

Guo M.,Southwest University | He R.,Southwest University | Dai Y.,Southwest University | Shen W.,Southwest University | And 3 more authors.
Journal of Physical Chemistry C | Year: 2012

A mass of porphyrin sensitizers have been designed and synthesized for dye-sensitized solar cells in previous works, and almost all of them incorporated an electron-rich system as the π-spacer. We here adopted the electron-deficient pyrimidine as an effective π-spacer and combined a cyanoacrylic acid anchoring group, as such a design yields a more bathochromic shift of the spectral absorption of the dye and results in an improved spectral overlap with the solar spectrum and an enhanced light-harvesting efficiency. The result does tally with the performance of sensitizer adsorbing on a semiconductor. From the electron density difference plots of electron transitions, we found that not all electron transitions could make for the effective electron transfer from donor to acceptor groups, which means the sensitizer performance in dye-sensitized solar cells not only relies on the extrinsic spectral absorption intensity but also depends on the intrinsic character of electron movement related to electron excitation. Moreover, the introduction of electron-deficient pyrimidine could affect the energy levels of excited molecules in solution, further affecting the kinds of electron transfer processes. We presented several novel porphyrin sensitizers for comparison on how the π-spacer and anchoring group influence the optical absorption, electron transfer processes, and regeneration of the oxidized dyes, thereby gaining potential dye-sensitized solar cells with highly efficient photo-to-electric conversion performances. © 2012 American Chemical Society.

Zhang Z.,Southwest University | Xiong Z.,Southwest University
Plasmonics | Year: 2010

The extinction spectra and electric field distributions of hollow triangular nanoprisms are calculated using the discrete dipole approximation method and compared with those of the solid triangular nanoprisms. When light propagates along the prisms, the main plasmon peaks of hollow triangular nanoprisms red shift compared with those of the solid triangular nanoprisms. At the main plasmon peaks, the hollow triangular nanoprisms provide more hot spots than the solid triangular nanoprisms. Therefore, the hollow triangular nanoprisms are more surface-enhanced Raman scattering active than the solid triangular prisms and can be used to detect small amount of molecules. For the hollow triangular nanoprism, although the local electric field distribution extremely relates to the incident polarization, the extinction spectra are independent of the incident polarization. In addition, the main plasmon peaks red shift linearly with the edge length, while they blue shift exponentially with the increase of the thickness of the hollow triangular nanoprisms. These results could be used to engineer hollow triangular nanoprisms for specific plasmonic applications. © 2010 Springer Science+Business Media, LLC.

Jiang H.,Southwest University | Jiang H.,Kansas State University | Wei Z.,Kansas State University | Nachman R.J.,U.S. Department of Agriculture | And 2 more authors.
Scientific Reports | Year: 2014

The evolution of peptidergic signaling has been accompanied by a significant degree of ligand-receptor coevolution. Closely related clusters of peptide signaling molecules are observed to activate related groups of receptors, implying that genes encoding these ligands may orchestrate an array of functions, a phenomenon known as pleiotropy. Here we examine whether pleiotropic actions of peptide genes might influence ligand-receptor coevolution. Four test groups of neuropeptides characterized by conserved C-terminal amino acid sequence motifs and their cognate receptors were examined in the red flour beetle (Tribolium castaneum): 1) cardioacceleratory peptide 2b (CAPA); CAPAr, 2) pyrokinin/diapause hormone (PK1/DH); PKr-A, -B, 3) pyrokinin/pheromone biosynthesis activating hormone (PK2/PBAN); PKr-C, and 4) ecdysis triggering hormone (ETH); ETHr-b. Ligand-receptor specificities were established through heterologous expression of receptors in cell-based assays for 9 endogenous ligands. Based on ligand-receptor specificity analysis, we found positive pleiotropism exhibited by ETH on ETHR-b and CAPAr, whereas PK1/DH and CAPA are more highly selective for their respective authentic receptors than would be predicted by phylogenetic analysis. Disparities between evolutionary trees deduced from receptor sequences vs. functional ligand-receptor specificities lead to the conclusion that pleiotropy exhibited by peptide genes influences ligand-receptor coevolution.

Zhang H.-B.,University of Virginia | Zhang H.-B.,Southwest University | Bokowiec M.T.,University of Virginia | Rushton P.J.,University of Virginia | And 4 more authors.
Molecular Plant | Year: 2012

Biotic and abiotic stress lead to elevated levels of jasmonic acid (JA) and its derivatives and activation of the biosynthesis of nicotine and related pyridine alkaloids in cultivated tobacco (Nicotiana tabacum L.). Among the JA-responsive genes is NtPMT1a, encoding putrescine N-methyl transferase, a key regulatory enzyme in nicotine formation. We have characterized three genes (NtMYC2a, b, c) encoding basic helix-loop-helix (bHLH) transcription factors (TFs) whose expression is rapidly induced by JA and that specifically activate JA-inducible NtPMT1a expression by binding a G-box motif within the NtPMT1a promoter in in vivo and in vitro assays. Using split-YFP assays, we further show that, in the absence of JA, NtMYC2a and NtMYC2b are present as nuclear complexes with the NtJAZ1 repressor. RNA interference (RNAi)-mediated knockdown of NtMYC2a and NtMYC2b expression results in significant decreases in JA-inducible NtPMT1a transcript levels, as well as reduced levels of transcripts encoding other enzymes involved in nicotine and minor alkaloid biosynthesis, including an 80-90% reduction in the level of transcripts encoding the putative nicotine synthase gene NtA662. In contrast, ectopic overexpression of NtMYC2a and NtMYC2b had no effect on NtPMT1a expression in the presence or absence of exogenously added JA. These data suggest that NtMYC2a, b, c are required components of JA-inducible expression of multiple genes in the nicotine biosynthetic pathway and may act additively in the activation of JA responses. © 2011 The Author.

Ren W.,Beijing Normal University | Ren W.,Southwest University | Zhou E.,Beijing Normal University | Fang B.,Beijing Normal University | And 3 more authors.
Chemical Science | Year: 2014

The Si-H bond addition to a terminal actinide imido complex was comprehensively studied. The base-free thorium imido [η5-1,2,4- (Me3C)3C5H2]2ThN(p-tolyl) (1) activates Si-H bonds in PhSiH3 or Ph2SiH2 to give the thorium amido hydrido metallocenes [η5-1,2,4-(Me 3C)3C5H2]2Th(H)[N(p- tolyl)SiH2Ph] (2) and [η5-1,2,4-(Me3C) 3C5H2]2Th(H)[N(p-tolyl)SiHPh 2] (3), respectively. Complex 2 readily inserts unsaturated molecules into the Th-H bond, whereas complex 3 reversibly activates an intramolecular aromatic C-H bond to yield [η5-1,2,4-(Me3C) 3C5H2]2Th[η2-N,C- {N(p-MeC6H3)(SiHPh2)}] (4) and H2. The experimental results have been complemented by density functional theory (DFT) studies and provide a detailed understanding of the observed reactivity. In addition, a comparison between Th and early transition metals reveals that the Th4+ behaves more like an actinide than a transition metal. © the Partner Organisations 2014.

Hu Z.,Liaoning Normal University | Hanley J.R.,University of Essex | Zhang R.,Southwest University | Liu Q.,Liaoning Normal University | Roberson D.,University of Essex
Psychonomic Bulletin and Review | Year: 2014

Categorical perception (CP) of color manifests as faster or more accurate discrimination of two shades of color that straddle a category boundary (e.g., one blue and one green) than of two shades from within the same category (e.g., two different shades of green), even when the differences between the pairs of colors are equated according to some objective metric. The results of two experiments provide new evidence for a conflict-based account of this effect, in which CP is caused by competition between visual and verbal/categorical codes on within-category trials. According to this view, conflict arises because the verbal code indicates that the two colors are the same, whereas the visual code indicates that they are different. In Experiment 1, two shades from the same color category were discriminated significantly faster when the previous trial also comprised a pair of within-category colors than when the previous trial comprised a pair from two different color categories. Under the former circumstances, the CP effect disappeared. According to the conflict-based model, response conflict between visual and categorical codes during discrimination of within-category pairs produced an adjustment of cognitive control that reduced the weight given to the categorical code relative to the visual code on the subsequent trial. Consequently, responses on within-category trials were facilitated, and CP effects were reduced. The effectiveness of this conflict-based account was evaluated in comparison with an alternative view that CP reflects temporary warping of perceptual space at the boundaries between color categories. © 2014, Psychonomic Society, Inc.

Ren W.,Southwest University | Ren W.,Beijing Normal University | Zhao N.,Beijing Normal University | Chen L.,Beijing Normal University | Zi G.,Beijing Normal University
Inorganic Chemistry Communications | Year: 2013

Treatment of the chloride metallocene [η5-1,3-(Me 3C)2C5H3]2ThCl 2 or [η5-1,2,4-(Me3C)3C 5H2]2ThCl2 with 2 equiv of PhCH 2K in diethyl ether at room temperature gives, after recrystallization from a benzene solution, the benzyl metallocenes [η5-1,3-(Me3C)2C5H 3]2Th(CH2Ph)2 (1) and [η5-1,2,4-(Me3C)3C5H 2]2Th(CH2Ph)2 (2), respectively, in good yields. Complexes 1 and 2 have been characterized by various spectroscopic techniques, elemental analyses, and X-ray diffraction analyses. They are active catalysts for the polymerization of rac-lactide, leading to the atactic polylactides with high molecular weights and narrow molecular weight distributions. © 2013 Elsevier B.V.

Zou X.,Southwest University | Zou X.,Ohio State University | Zhou Y.,Ohio State University | Zhou Y.,Boprocessing Innovative Company | Yang S.-T.,Ohio State University
Biotechnology and Bioengineering | Year: 2013

Malic acid is a dicarboxylic acid widely used in the food industry and also a potential C4 platform chemical that can be produced from biomass. However, microbial fermentation for direct malic acid production is limited by low product yield, titer, and productivity due to end-product inhibition. In this work, a novel process for malic acid production from polymalic acid (PMA) fermentation followed by acid hydrolysis was developed. First, a PMA-producing Aureobasidium pullulans strain ZX-10 was screened and isolated. This microbe produced PMA as the major fermentation product at a high-titer equivalent to 87.6g/L of malic acid and high-productivity of 0.61g/Lh in free-cell fermentation in a stirred-tank bioreactor. Fed-batch fermentations with cells immobilized in a fibrous-bed bioreactor (FBB) achieved the highest product titer of 144.2g/L and productivity of 0.74g/Lh. The fermentation produced PMA was purified by adsorption with IRA-900 anion-exchange resins, achieving a ∼100% purity and a high recovery rate of 84%. Pure malic acid was then produced from PMA by hydrolysis with 2M sulfuric acid at 85°C, which followed the first-order reaction kinetics. This process provides an efficient and economical way for PMA and malic acid production, and is promising for industrial application. © 2013 Wiley Periodicals, Inc.

Ren W.,Beijing Normal University | Ren W.,Southwest University | Lukens W.W.,Lawrence Berkeley National Laboratory | Zi G.,Beijing Normal University | And 2 more authors.
Chemical Science | Year: 2013

Bipyridyl thorium metallocenes [η5-1,2,4-(Me 3C)3C5H2]2Th(bipy) (1) and [η5-1,3-(Me3C)2C5H 3]2Th(bipy) (2) have been investigated by magnetic susceptibility and computational studies. The magnetic susceptibility data reveal that 1 and 2 are not diamagnetic, but they behave as temperature independent paramagnets (TIPs). To rationalize this observation, density functional theory (DFT) and complete active space self-consistent field (CASSCF) calculations have been undertaken, which indicated that Cp′ 2Th(bipy) has indeed a Th(iv)(bipy2-) ground state (f 0d0π*2, S = 0), but the open-shell singlet (f0d1π*1, S = 0) (almost degenerate with its triplet congener) is only 9.2 kcal mol-1 higher in energy. Complexes 1 and 2 react cleanly with Ph2CS to give [η5-1,2,4-(Me3C)3C5H 2]2Th[(bipy)(SCPh2)] (3) and [η5-1,3-(Me3C)2C5H 3]2Th[(bipy)(SCPh2)] (4), respectively, in quantitative conversions. Since no intermediates were observed experimentally, this reaction was also studied computationally. Whereas coordination of Ph 2CS to 2 in its S = 0 ground state is not possible, Ph2CS can coordinate to 2 in its triplet state (S = 1) upon which a single electron transfer (SET) from the (bipy2-) fragment to Ph2CS followed by C-C coupling takes place. © 2013 The Royal Society of Chemistry.

Su L.,University of Connecticut | Jia W.,University of California at San Diego | Li C.-M.,Nanyang Technological University | Li C.-M.,Southwest University | Lei Y.,University of Connecticut
ChemSusChem | Year: 2014

As a new generation of power sources, fuel cells have shown great promise for application in transportation. However, the expensive catalyst materials, especially the cathode catalysts for oxygen reduction reaction (ORR), severely limit the widespread commercialization of fuel cells. Therefore, this review article focuses on platinum (Pt)-based electrocatalysts for ORR with better catalytic performance and lower cost. Major breakthroughs in the improvement of activity and durability of electrocatalysts are discussed. Specifically, on one hand, the enhanced activity of Pt has been achieved through crystallographic control, ligand effect, or geometric effect; on the other hand, improved durability of Pt-based cathode catalysts has been realized by means of the incorporation of another noble metal or the morphological control of nanostructures. Furthermore, based on these improvement mechanisms, rationally designed Pt-based nanoparticles are summarized in terms of different synthetic strategies such as wet-chemical synthesis, Pt-skin catalysts, electrochemically dealloyed nanomaterials, and Pt-monolayer deposition. These nanoparticulate electrocatalysts show greatly enhanced catalytic performance towards ORR, aiming not only to outperform the commercial Pt/C, but also to exceed the US Department of Energy 2015 technical target ($30/kW and 5000?h). Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Dong T.,Southwest University | Dong T.,Chongqing University of Posts and Telecommunications | Liao X.,Southwest University
Nonlinear Dynamics | Year: 2013

In this paper, a tri-neuron BAM neural network model with multiple delays is considered. We show that the connection topology of the network plays a fundamental role in classifying the rich dynamics and bifurcation phenomena. There is a wide range of different dynamical behaviors which can be produced by varying the coupling strength. By choosing the connected weights c21 and c31 (the connection weights through the neurons from J-layer to I-layer) as bifurcation parameters, the critical values where a Bogdanov-Takens bifurcation occurs are derived. Then, by computing the normal forms for the system, the bifurcation diagrams are obtained. Furthermore, some interesting phenomena, such as saddle-node bifurcation, pitchfork bifurcation, homoclinic bifurcation, heteroclinic bifurcation and double limit cycle bifurcation are found by choosing the different connection strengths. Some numerical simulations are given to support the analytic results. © Springer Science+Business Media Dordrecht 2012.

Huang S.,Southwest University | Su X.,Shanghai JiaoTong University | Hu Y.,Guangdong University of foreign Studies | Mahadevan S.,Vanderbilt University | And 3 more authors.
Knowledge-Based Systems | Year: 2014

Decision-making is an essential but difficult problem under uncertain environment. Many researchers have addressed it in the framework of the AHP. The AHP has many advantages. However, the incomplete information resulted from the limited precision of human assessments reduces its effectiveness in many applications. In this paper, a new method is proposed for decision-making by incomplete information based on evidence distance with using of DS theory to extend the AHP. The main feature of the proposed method is the weight of criteria are assigned with the consistency and similarity of the opinions from experts or decision makers. The operation of preferences is defined in the framework of DS theory. The final decision is obtained with pignistic probability transformation. Numerical examples are used to illustrate the reasonability of the proposed method. © 2013 Elsevier B.V. All rights reserved.

Valentini E.,University of Rome La Sapienza | Valentini E.,Instituto Of Ricovero E Cura A Carattere Scientifico | Betti V.,Instituto Of Ricovero E Cura A Carattere Scientifico | Betti V.,University of Chieti Pescara | And 4 more authors.
Cortex | Year: 2013

Introduction: Neuroimaging studies indicate that hypnotic suggestions of increased and decreased pain intensity and unpleasantness may modulate somatosensory and cingulate cortex activity, respectively. Methods: Using a within subject design and a strict subject selection procedure, we tested in High (Highs) and Low (Lows) hypnotically suggestible individuals whether hypnotic suggestions of sensory and affective hypoalgesia or hyperalgesia differentially affected subjective ratings of laser-induced pain and nociceptive-related brain activity in the time- and time-frequency domain. Results: Hypnotic modulation of pain intensity and unpleasantness affected subjective ratings of laser-induced pain only in Highs. Such modulation was more specific for unpleasantness manipulation and more evident for suggestions of hyperalgesia. Importantly, Highs and Lows showed increase and decrease of P2a and P2b wave amplitudes and gamma band power, respectively. Conclusions: Hypnotic suggestions exerted a top-down modulatory effect on both evoked and induced-cortical brain responses triggered by selective nociceptive laser inputs. Furthermore, correlation analyses indicated that gamma power modulation and suggestions of hyperalgesia may reflect the process of allocating control resources to salient and threatening sensory-affective dimensions of pain. © 2012 Elsevier Ltd.

Zhang X.,Southwest University | Deng Y.,Southwest University | Deng Y.,Vanderbilt University | Chan F.T.S.,Hong Kong Polytechnic University | And 3 more authors.
International Journal of Production Research | Year: 2013

The Job-Shop Scheduling Problem (JSP) is an important concern in advanced manufacturing systems. In real applications, uncertainties exist practically everywhere in the JSP, ranging from engineering design to product manufacturing, product operating conditions and maintenance. A variety of approaches have been proposed to handle the uncertain information. Among them, the Intuitionistic Fuzzy Sets (IFS) is a novel tool with the ability to handle vague information and is widely used in many fields. This paper develops a method to address the JSP under an uncertain environment based on IFSs. Another contribution of this paper is to put forward a generalised (or extended) IFS to process the additive operation and to compare the operation between two IFSs. The methodology is illustrated using a three-step procedure. First, a transformation is constructed to convert the uncertain information in the JSP into the corresponding IFS. Secondly, a novel addition operation between two IFSs is proposed that is suitable for the JSP. Then a novel comparison operation on two IFSs is presented. Finally, a procedure is constructed using the chromosome of an operation-based representation and a genetic algorithm. Two examples are used to demonstrate the efficiency of the proposed method. In addition, a comparison between the results of the proposed IFSJSP and other existing approaches demonstrates that IFSJSP significantly outperforms other existing methods. © 2013 Taylor and Francis.

Xie J.L.,Southwest University | Xie J.L.,Chongqing Key Laboratory for Advanced Materials and Technologies of Clean Electrical Power Sources | Guo C.X.,Southwest University | Guo C.X.,Chongqing Key Laboratory for Advanced Materials and Technologies of Clean Electrical Power Sources | And 2 more authors.
Energy and Environmental Science | Year: 2014

One-dimensional (1D) nanostructures can efficiently scatter incident light, resulting in improved absorption or complete absorption for solar energy conversion and storage. However, 1D nanostructures often lack good conductivity for fast charge transfer and/or transport. A thin-layer coating of graphene gives superior conductivity for improving the charge transport ability while its highly transparency does not deteriorate the light absorption. Thus, construction of 1D nanostructured materials on graphene as an electrode to synergistically boost high-efficiency energy conversion and storage have attracted great attention in recent years. In this feature review, starting with general concepts of 1D nanostructures on a substrate, various advanced methods for the design, fabrication and characterization of different 1D nanostructures comprising inorganic, organic and hybrid materials built on graphene are systematically surveyed. In particular, the significant progress in fabrication strategies, superior nanostructures and unique architectures is discussed, while the excellent electrical, optical, mechanical, and electrochemical properties of the nanostructured composites as well as their important applications in lithium-ion batteries, supercapacitors, solar cells, light-emitting diodes and nanogenerators are also presented. The enhancement mechanisms for the efficient energy conversion and storage are highlighted to elicit scientific insights. The challenges and prospects are also deliberated to spark our future researches. This review provides critical and updated knowledge for researchers to further explore new 1D-structured materials on graphene and their important applications in energy conversion and storage. This journal is © the Partner Organisations 2014.

Su X.,Shanghai JiaoTong University | Deng Y.,Southwest University | Deng Y.,Vanderbilt University | Mahadevan S.,Vanderbilt University | Bao Q.,Shanghai JiaoTong University
Engineering Failure Analysis | Year: 2012

Dempster-Shafer (D-S) evidence theory has been previously introduced in failure modes and effects analysis (FMEA) due to its effectiveness and flexibility in dealing with uncertain and subjective information. This study applies the modified D-S evidence theory to obtain the risk priority evaluation of failure modes by aggregating different opinions of experts which may be imprecise and uncertain. However, when experts give different and precise values of the risk evaluation factors, the basic belief assignments (BBAs) become highly conflicting evidence that cannot be fused by Dempster's combination rule. In this paper, we propose an improved method to construct the basic belief assignments (BBAs) for risk evaluation. We illustrate several examples and use the modified method to deal with the risk priority evaluation of the failure modes of rotor blades of an aircraft engine. The results show that the proposed approach is more flexible and reasonable for real applications. © 2012 Elsevier Ltd.

Zhang J.,Nanyang Technological University | Guo C.,Southwest University | Guo C.,Chongqing Key Laboratory for Advanced Materials and Technologies of Clean Electrical Power Sources | Zhang L.,Southwest University | And 4 more authors.
Chemical Communications | Year: 2013

Three-dimensional manganese oxide is directly grown on reduced graphene oxide (RGO) sheets, exhibiting comparable catalytic activity, higher selectivity and better stability towards oxygen reduction reaction than those of the commercial Pt/XC-72 catalyst. © 2013 The Royal Society of Chemistry.

Xiao L.,Southwest University | Yi T.,Southwest University | Yi T.,Macau University of Science and Technology | Liu Y.,Wuhan Medical Treatment Center
Drug Development and Industrial Pharmacy | Year: 2013

A new self-microemulsifying mouth dissolving film (SMMDF) for poorly water-soluble drugs such as indomethacin was developed by incorporating self-microemulsifying components with solid carriers mainly containing microcrystalline cellulose, low-substituted hydroxypropyl cellulose and hypromellose. The uniformity of dosage units of the preparation was acceptable according to the criteria of Chinese Pharmacopoeia 2010. The SMMDF was disintegrated within 20 s after immersion into water, released completely at 5min in the dissolution medium and achieved microemulsion particle size of 28.81±3.26nm, which was similar to that of liquid self- microemulsifying drug delivery system (SMEDDS). Solid state characterization of the SMMDF was performed by SEM, DSC and X-ray powder diffraction. Results demonstrated that indomethacin in the SMMDF was in the amorphous state, which might be due to self-microemulsifying ingredients. Pharmacokinetic parameters in rats including Tmax, Cmax, AUC were similar between the SMMDF and liquid SMEDDS. AUC and Cmax from the SMMDF were significantly higher than those from the common mouth dissolving film or the conventional tablet, and Tmax from SMMDF group was also significantly decreased. These findings suggest that the SMMDF is a new promising dosage form, showing notable characteristics of convenience, quick onset of action and enhanced oral bioavailability of poorly water-soluble drugs. © 2013 Informa Healthcare USA, Inc.

Deng Y.,Shanghai JiaoTong University | Deng Y.,Southwest University | Chan F.T.S.,Hong Kong Polytechnic University | Wu Y.,Shanghai JiaoTong University | Wang D.,Shanghai JiaoTong University
Expert Systems with Applications | Year: 2011

Multiple-criteria decision-making (MCDM) is concerned with the ranking of decision alternatives based on preference judgements made on decision alternatives over a number of criteria. First, taking advantage of data fusion technology to comprehensively consider each criterion data is a reasonable idea to solve the MCDM problem. Second, in order to efficiently handle uncertain information in the process of decision making, some well developed mathematical tools, such as fuzzy sets theory and Dempster Shafer theory of evidence, are used to deal with MCDM. Based on the two main reasons above, a new fuzzy evidential MCDM method under uncertain environments is proposed. The rating of the criteria and the importance weight of the criteria are given by experts' judgments, represented by triangular fuzzy numbers. Then, the weights are transformed into discounting coefficients and the ratings are transformed into basic probability assignments. The final results can be obtained through the Dempster rule of combination in a simple and straight way. A numerical example to select plant location is used to illustrate the efficiency of the proposed method. © 2010 Elsevier Ltd. All rights reserved.

Deng Y.,Southwest University | Deng Y.,Shanghai JiaoTong University | Chan F.T.S.,Hong Kong Polytechnic University
Expert Systems with Applications | Year: 2011

Supplier selection is a multi-criterion decision making problem under uncertain environments. Hence, it is reasonable to hand the problem in fuzzy sets theory (FST) and Dempster Shafer theory of evidence (DST). In this paper, a new MCDM methodology, using FST and DST, based on the main idea of the technique for order preference by similarity to an ideal solution (TOPSIS), is developed to deal with supplier selection problem. The basic probability assignments (BPA) can be determined by the distance to the ideal solution and the distance to the negative ideal solution. Dempster combination rule is used to combine all the criterion data to get the final scores of the alternatives in the systems. The final decision results can be drawn through the pignistic probability transformation. In traditional fuzzy TOPSIS method, the quantitative performance of criterion, such as crisp numbers, should be transformed into fuzzy numbers. The proposed method is more flexible due to the reason that the BPA can be determined without the transformation step in traditional fuzzy TOPSIS method. The performance of criterion can be represented as crisp number or fuzzy number according to the real situation in our proposed method. The numerical example about supplier selection is used to illustrate the efficiency of the proposed method. © 2011 Published by Elsevier Ltd.

Li H.,Southwest University | Liao X.,Southwest University | Huang T.,Texas A&M University at Qatar | Zhu W.,Chongqing University of Posts and Telecommunications
IEEE Transactions on Automatic Control | Year: 2015

In this note, the problem of second-order leader-following consensus by a novel distributed event-triggered sampling scheme in which agents exchange information via a limited communication medium is studied. Event-based distributed sampling rules are designed, where each agent decides when to measure its own state value and requests its neighbor agents broadcast their state values across the network when a locally-computed measurement error exceeds a state-dependent threshold. For the case of fixed topology, a necessary and sufficient condition is established. For the case of switching topology, a sufficient condition is obtained under the assumption that the time-varying directed graph is uniformly jointly connected. It is shown that the inter-event intervals are lower bounded by a strictly positive constant, which excludes the Zeno-behavior before the consensus is achieved. Numerical simulation examples are provided to demonstrate the correctness of theoretical results. © 1963-2012 IEEE.

Chen T.,Nanyang Technological University | Chen T.,Chinese University of Hong Kong | Hu W.,Nanyang Technological University | Hu W.,Southwest University | And 6 more authors.
Advanced Functional Materials | Year: 2012

The microstructures of photoa and countera electrodes play critical roles in the performance of dyea sensitized solar cells (DSSCs). In particular, various interfaces, such as fluorinateda tin oxide (FTO)/TiO2, TiO2/TiO2, and TiO2/electrolyte, in DSSCs significantly affect the final power conversion efficiency (PCE). However, research has generally focused more on the design of various nanostructured semiconducting materials with emphasis on optimizing chemical or/and physical properties, and less on these interface functionalizations for performance improvement. This work explores a new application of graphene to modify the interface of FTO/TiO2 to suppress charge recombination. In combination with interfaces functionalization of TiO2/TiO2 for low chargea transport resistance and high chargea transfer rate, the final PCE of DSSC is remarkably improved from 5.80% to 8.13%, achieving the highest efficiency in comparison to reported graphene/TiO2-based DSSCs. The method of using graphene to functionalize the surface of FTO substrate provides a better alternative method to the conventional prea treatment through hydrolyzing TiCl4 and an approach to reduce the adverse effect of microstructural defect of conducting glass substrate for electronic devices. Graphene is found to suppress carrier recombination occurring on fluorinated tin oxide (FTO) surfaces and at FTO/TiO2 interfaces in dyea sensitized solar cells. With a graphene interlayer between FTO and TiO2, the device efficiency can be increased by 40% when compared with those using solely TiO2 as an anode material. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Guo Y.,Southwest University | Li G.,Charles Sturt University
Journal of Soils and Sediments | Year: 2012

Purpose: Improper utilization of composted manure might increase risk of nutrients leaching and phosphorus (P) accumulation, hence causing eutrophication and threatening the ecological safety of river. In the current study, composted manure from a goat feedlot was applied to a perennial pasture in the Three Gorges region to evaluate its effects on pasture yield, NO3-N leaching, and phosphorus accumulation in soil. Materials and methods: Composted goat manure was either topdressed by hand or incorporated by hoe in the 0-20 cm soil depth between rows at four application rates (15, 22.5, 30, and 37.5 Mg DM ha-1) and an unamended control without application of composted manure. The composted manure was applied five times, with 20 % of the designated amount each, in July, September, and November 2005 and January and April 2006. A combination leaching-incubation experiment (soil-resin-core) was conducted to measure the amount of NO3-N leached from soils. Results and discussion: Soil total nitrogen and P concentrations increased as amount of composted manure applied was increased. Soil NO3-N and NO3-N leached from soil varied across seasons. Soil available P reached 92, 132, 225, and 261 mg kg-1 when 15, 22. 5, 30, and 37. 5 Mg ha-1 of composted manure was incorporated, respectively, and soil available P reached 39, 78, 86, and 132 mg kg-1 for corresponding treatments for topdressed treatment, indicating soil available P accumulated with increased manure applied. Pasture yield increased as application rate of composted manure increased. For the topdressed treatments, the highest pasture yields were obtained at 37. 5 Mg ha-1 of composted manure applied. As a comparison, the highest pasture yields was obtained at 22.5 Mg ha-1 when composted manure was incorporated, further increase of composted manure decreased the pasture yields. Conclusions: Excess use of composted goat manure significantly increased the risk of soil NO3-N leaching and P accumulation. It is suggested that the composted goat manure should be incorporated at rate of less than 22. 5 Mg ha-1 to minimize NO3-N leaching and P accumulation while maintaining high pasture production. The split application is also recommended to meet the growth requirement of pastures, hence less NO3-N leaching and soil P accumulation, which is of importance in the Three Gorges region. © 2012 Springer-Verlag.

Deng Y.,Southwest University | Deng Y.,Shanghai JiaoTong University | Deng Y.,Vanderbilt University | Chen Y.,Shanghai JiaoTong University | And 2 more authors.
Applied Soft Computing Journal | Year: 2012

A common algorithm to solve the shortest path problem (SPP) is the Dijkstra algorithm. In this paper, a generalized Dijkstra algorithm is proposed to handle SPP in an uncertain environment. Two key issues need to be addressed in SPP with fuzzy parameters. One is how to determine the addition of two edges. The other is how to compare the distance between two different paths with their edge lengths represented by fuzzy numbers. To solve these problems, the graded mean integration representation of fuzzy numbers is adopted to improve the classical Dijkstra algorithm. A numerical example of a transportation network is used to illustrate the efficiency of the proposed method. © 2011 Elsevier B.V. All rights reserved.

Guo C.X.,Southwest University | Guo C.X.,Nanyang Technological University | Shen Y.Q.,Nanyang Technological University | Dong Z.L.,Nanyang Technological University | And 5 more authors.
Energy and Environmental Science | Year: 2012

Through the PO4 3- groups regularly arranged on its sugar-phosphate backbone, DNA is used to direct the growth of a network structure of ultrasmall FePO4 nanoparticles on double-wall carbon nanotubes. The resulting structure has achieved nearly 100% theoretical storage capacity for the FePO4 active component as a cathode in lithium-ion batteries. © 2012 The Royal Society of Chemistry.

Ding J.,Georgia Regents University | Li T.,Georgia Regents University | Li T.,Southwest University | Wang X.,Chongqing Medical University | And 10 more authors.
Cell Metabolism | Year: 2013

Increased activation of the serine-glycine biosynthetic pathway is an integral part of cancer metabolism that drives macromolecule synthesis needed for cell proliferation. Whether this pathway is under epigenetic control is unknown. Here we show that the histone H3 lysine 9 (H3K9) methyltransferase G9A is required for maintaining the pathway enzyme genes in an active state marked by H3K9 monomethylation and for the transcriptional activation of this pathway in response to serine deprivation. G9A inactivation depletes serine and its downstream metabolites, triggering cell death with autophagy in cancer cell lines of different tissue origins. Higher G9A expression, which is observed in various cancers and is associated with greater mortality in cancer patients, increases serine production and enhances the proliferation and tumorigenicity of cancer cells. These findings identify a G9A-dependent epigenetic program in the control of cancer metabolism, providing a rationale for G9A inhibition as a therapeutic strategy for cancer. © 2013 Elsevier Inc.

Xu P.,Shanghai JiaoTong University | Deng Y.,Shanghai JiaoTong University | Deng Y.,Southwest University | Deng Y.,Vanderbilt University | And 2 more authors.
Knowledge-Based Systems | Year: 2013

Abstract The Dempster-Shafer evidence theory (D-S theory) is one of the primary tools for knowledge representation and uncertain reasoning, and has been widely used in many information fusion systems. However, how to determine the basic probability assignment (BPA), which is the main and first step in D-S theory, is still an open issue. In this paper, based on the normal distribution, a method to obtain BPA is proposed. The training data are used to build a normal distribution-based model for each attribute of the data. Then, a nested structure BPA function can be constructed, using the relationship between the test data and the normal distribution model. A normality test and normality transformation are integrated into the proposed method to handle non-normal data. The missing attribute values in datasets are addressed as ignorance in the framework of the evidence theory. Several benchmark pattern classification problems are used to demonstrate the proposed method and to compare against existing methods. Experiments provide encouraging results in terms of classification accuracy, and the proposed method is seen to perform well without a large amount of training data. © 2013 Elsevier B.V. © 2013 Elsevier B.V. All rights reserved.

Zhang L.,Chongqing University of Posts and Telecommunications | Tang Y.,Southwest University
Proceedings of the 8th International Conference on Computer Science and Education, ICCSE 2013 | Year: 2013

Keywords Extraction plays a very important role in the text mining domain, since the keywords can represent the asserted main point in a document. Based on term network and deleting actor index, an effective keywords extraction algorithm is proposed to extract high frequent terms as well as important terms with low frequency. The experiment results support the conclusion. © 2013 IEEE.

Guo Y.,Southwest University | Tang H.,Southwest University | Li G.,Charles Sturt University | Xie D.,Southwest University
Water, Air, and Soil Pollution | Year: 2014

A laboratory-scale study was conducted to test whether biochar from cow dung as a soil amendment can reduce nutrient leaching from soil irrigated with biogas slurry. Polyvinyl chloride (PVC) columns were packed with soils containing 0, 20, and 40 g kg-1 of biochar. The biogas slurry was applied at 0, 200, and 400 ml per column, equivalent to 0, 130, and 260 kg N ha-1. The biogas slurry was diluted to 1,500 ml with water and then applied five times every 6 days at 300 ml each time. All leached solutions were collected separately. Results showed that soil available phosphorus (P) and potassium (K) increased significantly with increased biogas slurry rates and biochar rates. The concentrations of total N, P, and K in leached solutions increased significantly as biogas slurry rates increased. Biochar significantly increased the concentrations of total and available P, total K, and electric conductance in leached solution. Contributions of biochar and biogas slurry treatments to the net amount ofN, P, and K in leached solution increased with increased biochar and biogas slurry rates except at 4 % biochar rate where total N was decreased. Nutrient removal rate of biochar was over 10.6 % for total N and negative for total K at 2 % biochar rate. Nutrient removal rate of biochar was over 7.19 % for total P and negative for total N and total K at 4 % biochar rate. It is suggested that both biogas slurry and biochar have the potential to pollute water when leaching happens although biochar has the ability to adsorb N and P from biogas slurry. © 2013 Springer Science+Business Media Dordrecht.

DiMartino A.,NYU Langone Medical Center | Fair D.A.,Oregon Health And Science University | Kelly C.,NYU Langone Medical Center | Satterthwaite T.D.,University of Pennsylvania | And 11 more authors.
Neuron | Year: 2014

The vast majority of mental illnesses can be conceptualized as developmental disorders of neural interactions within the connectome, or developmental miswiring. The recent maturation of pediatric invivo brain imaging is bringing the identification of clinically meaningful brain-based biomarkers of developmental disorders within reach. Even more auspicious is the ability to study the evolving connectome throughout life, beginning in utero, which promises to move the field from topological phenomenology to etiological nosology. Here, we scope advances in pediatric imaging of the brain connectome as the field faces the challenge of unraveling developmental miswiring. We highlight promises while also providing a pragmatic review of the many obstacles ahead that must be overcome to significantly impact public health. © 2014 Elsevier Inc.

Zhao X.,Southwest University | Zhao X.,Chongqing Key Laboratory of Agricultural Resources and Environment | Jiang T.,Southwest University | Jiang T.,Chongqing Key Laboratory of Agricultural Resources and Environment | And 2 more authors.
Chemosphere | Year: 2014

Batch experiments and sequential extraction analysis were employed to investigate the effects of soil organic matter and CaCO3 on the adsorption and desorption of cadmium (Cd2+) onto and from two purple paddy soils, an acidic purple paddy soil (APPS) and a calcareous purple paddy soil (CPPS). The Cd2+ adsorption isotherms on both soils could be well-described by the Langmuir and Freundlich equations. CPPS had a higher capacity and a stronger affinity for Cd2+ adsorption compared with APPS. The adsorption process of Cd2+ on APPS was dominated by electrostatic attractions, whereas the adsorption mechanism varied depending on the Cd2+ concentrations in equilibrium solutions on CPPS. At low equilibrium concentrations, the adsorption process was primarily specific adsorption, but nonspecific adsorption dominated at high equilibrium concentrations. Removal of organic matter decreased the amount of Cd2+ adsorption on both of the soils, slightly affected the Cd2+ desorption rate and exchangeable Cd (EXC-Cd) in APPS and increased the desorption rate and EXC-Cd in CPPS, suggesting that the effect of organic matter on Cd2+ adsorption-desorption depends on the soils. CPPS and APPS containing CaCO3 exhibited higher adsorption amounts but lower desorption rates and lower proportions of EXC-Cd than those of their corresponding soils without CaCO3, demonstrating that CaCO3 played an important role in Cd2+ specific adsorption on soil. The changes in the thermodynamic parameters, including free energy (δG0), enthalpy (δH0) and entropy (δS0), as evaluated by the Van't Hoff equations, indicated that the adsorption was a spontaneous and endothermic process with the primary interaction forces of dipole interactions and hydrogen bonds on APPS, whereas both physical and chemical interactions dominated the adsorption on CPPS. © 2013 Elsevier Ltd.

Wang Z.,Southwest University | Wang Z.,Hong Kong Baptist University | Wang L.,City University of Hong Kong | Szolnoki A.,Hungarian Academy of Sciences | And 2 more authors.
European Physical Journal B | Year: 2015

Networks form the backbone of many complex systems, ranging from the Internet to human societies. Accordingly, not only is the range of our interactions limited and thus best described and modeled by networks, it is also a fact that the networks that are an integral part of such models are often interdependent or even interconnected. Networks of networks or multilayer networks are therefore a more apt description of social systems. This colloquium is devoted to evolutionary games on multilayer networks, and in particular to the evolution of cooperation as one of the main pillars of modern human societies. We first give an overview of the most significant conceptual differences between single-layer and multilayer networks, and we provide basic definitions and a classification of the most commonly used terms. Subsequently, we review fascinating and counterintuitive evolutionary outcomes that emerge due to different types of interdependencies between otherwise independent populations. The focus is on coupling through the utilities of players, through the flow of information, as well as through the popularity of different strategies on different network layers. The colloquium highlights the importance of pattern formation and collective behavior for the promotion of cooperation under adverse conditions, as well as the synergies between network science and evolutionary game theory. © 2015, EDP Sciences, SIF, Springer-Verlag Berlin Heidelberg.

Su X.,Shanghai University of Electric Power | Mahadevan S.,Vanderbilt University | Xu P.,Shanghai JiaoTong University | Deng Y.,Southwest University
Risk Analysis | Year: 2015

Dependence assessment among human errors in human reliability analysis (HRA) is an important issue. Many of the dependence assessment methods in HRA rely heavily on the expert's opinion, thus are subjective and may sometimes cause inconsistency. In this article, we propose a computational model based on the Dempster-Shafer evidence theory (DSET) and the analytic hierarchy process (AHP) method to handle dependence in HRA. First, dependence influencing factors among human tasks are identified and the weights of the factors are determined by experts using the AHP method. Second, judgment on each factor is given by the analyst referring to anchors and linguistic labels. Third, the judgments are represented as basic belief assignments (BBAs) and are integrated into a fused BBA by weighted average combination in DSET. Finally, the CHEP is calculated based on the fused BBA. The proposed model can deal with ambiguity and the degree of confidence in the judgments, and is able to reduce the subjectivity and improve the consistency in the evaluation process. © 2015 Society for Risk Analysis.

Li H.,Southwest University | Liao X.,Southwest University | Huang T.,Texas A&M University at Qatar | Wang Y.,Chongqing University of Posts and Telecommunications | And 2 more authors.
Information Sciences | Year: 2014

This paper discusses the second-order globally nonlinear consensus in general multi-agent directed networks with both non-time-delay and time-delay couplings. Some easily manageable delay-independent algebraic criteria are presented to unravel the underlying mechanics for reaching the second-order consensus. The obtained results are associated with the underlying network interactive topologies, inner coupling matrices and coupling gains between agents. Theoretical derivation is complemented by its validation on a simulation example. © 2013 Elsevier Inc. All rights reserved.

Ji L.,Chongqing University of Posts and Telecommunications | Ji L.,Southwest University | Liu Q.,Chongqing University of Posts and Telecommunications | Liao X.,Southwest University
Information Sciences | Year: 2014

In this paper, the problems of group consensus for linearly coupled multi-agent networks including first-order and second-order are investigated, respectively. Based on the Laplacian matrix associated with the weighted adjacency matrix of the system, we present two novel linear protocols which can exactly reflect the interactive influence between the agents of the multi-agent network. Instead of relying on other conservative assumptions presented by the majority of the relevant research works, some promising criteria which can guarantee the reaching of group consensus of the multi-agent network are also obtained analytically. In addition, we also extend our work to study the group consensus for the multi-agent network with generally connected topology which neither needs to be strongly connected nor needs to contain a directed spanning tree. The conclusion that we have obtained should be more representative. Finally, the validity and correctness of our theoretical results are verified by several numerical simulated examples. © 2014 Published by Elsevier Inc.

Liao X.,Southwest University | Ji L.,Chongqing University of Posts and Telecommunications
Neurocomputing | Year: 2014

In this paper, we focus on investigating group consensus of dynamical multi-agent networks via pinning scheme. The topology of the network is a general digraph, which needs neither being symmetric nor containing a spanning directed tree, and some criteria are proposed to guarantee the realization of group consensus instead of relying on other conservative assumptions presented by majority of the relevant research works, such as in-degree balance. In addition, it is interesting to find that the nodes with zero in-degree should be pinned first based on the property of M-matrix. Furthermore, an adaptive pinning control approach is developed to obtain the appropriate control gains. Finally, the effectiveness and correctness of our theoretical findings are verified by some numerical simulations. © 2014 Elsevier B.V.

Liu Z.,Chinese Academy of science | Liu Z.,Chinese Academy of Geological Sciences | Dreybrodt W.,University of Bremen | Wang H.,Chinese Academy of science | Wang H.,Southwest University
Earth-Science Reviews | Year: 2010

The magnitudes, variations, locations and mechanisms responsible for the global atmospheric CO2 sink are uncertain and under continuing debate. Previous studies have focused mainly on the sinks in the oceans, and soil and vegetation on the continents. Here, we show, based on theoretical calculations and field monitoring evidence, that there is an important but previously underestimated sink for atmospheric CO2 as DIC-dissolved inorganic carbon that results from the combined action of carbonate dissolution, the global water cycle and the photosynthetic uptake of DIC by aquatic organisms in ocean and land. The sink constitutes up to 0.8242Pg C/a, amounting to 29.4% of the terrestrial CO2 sink, or 10.4% of the total anthropogenic CO2 emission. 0.244 PgC/a are transferred to the sea via continental rivers and 0.2278Pg C/a by meteoric precipitation over the seas. 0.119Pg C/a is released back to the atmosphere again, and 0.2334Pg C/a is stored in the continental aquatic ecosystem. Therefore, the net sink is estimated as 0.7052Pg C/a. This sink may increase with an intensification of the global water cycle as a consequence of global warming, rising anthropogenic emissions of CO2 and carbonate dust in atmosphere, and afforestation, which increases the soil pCO2 and thus the carbonate dissolution. Fertilization with the elements N, P, C, Fe, Zn, and Si increases the organic matter storage/burial by aquatic organisms and thus decreases the CO2 return to the atmosphere. Based on the ensemble mean projection of global warming for the year 2100 by IPCC, it is estimated that the atmospheric CO2 sink will increase by 21%, or about 0.18Pg C/a. However, the uncertainty in the estimation of this sink needs further exploration. © 2010 Elsevier B.V.

News Article | September 7, 2016

Edible ginger-derived nano-lipids created from a specific population of ginger nanoparticles show promise for effectively targeting and delivering chemotherapeutic drugs used to treat colon cancer, according to a study by researchers at the Institute for Biomedical Sciences at Georgia State University, the Atlanta Veterans Affairs Medical Center, and Wenzhou Medical University and Southwest University in China. Colorectal cancer is the third most common cancer among men and women in the U.S., and the second-leading cause of cancer-related deaths among men and women worldwide. The incidence of colorectal cancer has increased over the last few years, with about one million new cases diagnosed annually. Non-targeted chemotherapy is the most common therapeutic strategy available for colon cancer patients, but this treatment method is unable to distinguish between cancerous and healthy cells, leading to poor therapeutic effects on tumor cells and severe toxic side effects on healthy cells. Enabling chemotherapeutic drugs to target cancer cells would be a major development in the treatment of colon cancer. In this study, the researchers isolated a specific nanoparticle population from edible ginger (GDNP 2) and reassembled their lipids, naturally occurring molecules that include fats, to form ginger-derived nano-lipids, also known as nanovectors. To achieve accurate targeting of tumor tissues, the researchers modified the nanovectors with folic acid to create FA-modified nanovectors (FA nanovectors). Folic acid shows high-affinity binding to the folate receptors that are highly expressed on many tumors and almost undetectable on non-tumor cells. The FA nanovectors were tested as a delivery platform for doxorubicin, a chemotherapeutic drug used to treat colon cancer. The researchers found that doxorubicin was efficiently loaded into the FA nanovectors, and the FA nanovectors were efficiently taken up by colon cancer cells, exhibited excellent biocompatibility and successfully inhibited tumor growth. Compared to a commercially available option for delivering doxorubicin, the FA nanovectors released the drug more rapidly in an acidic pH that resembled the tumor environment, suggesting this delivery strategy could decrease the severe side effects of doxorubicin. These findings were published in the journal Molecular Therapy. “Our results show that FA nanovectors made of edible ginger-derived lipids could shift the current paradigm of drug delivery away from artificially synthesized nanoparticles toward the use of nature-derived nanovectors from edible plants,” says Dr. Didier Merlin, a professor in the Institute for Biomedical Sciences at Georgia State and a Research Career Scientist at the VA Medical Center. “Because they are nontoxic and can be produced on a large scale, FA nanovectors derived from edible plants could represent one of the safest targeted therapeutic delivery platforms.” Dr. Mingzhen Zhang of the Institute for Biomedical Sciences at Georgia State is the first author of the study. Co-authors of the study include Dr. Emilie Viennois, Dr. Zhan Zhang and Moon Kwon Han of the Institute for Biomedical Sciences at Georgia State; Dr. Bo Xiao of the Institute for Biomedical Sciences at Georgia State and Southwest University in Chonqing, China; and Dr. Changlong Xu of the Institute for Biomedical Sciences at Georgia State and Wenzhou Medical University in Wenzhou, China. The study was supported by the National Institute of Diabetes and Digestive and Kidney Diseases of the National Institutes of Health, the Department of Veterans Affairs, and the Crohn’s & Colitis Foundation of America.

News Article | April 8, 2016

Abstract: Nanoparticles designed to block a cell-surface molecule that plays a key role in inflammation could be a safe treatment for inflammatory bowel disease (IBD), according to researchers in the Institute for Biomedical Sciences at Georgia State University and Southwest University in China. The scientists developed nanoparticles, or microscopic particles, to reduce the expression of CD98, a glycoprotein that promotes inflammation. Their findings are published in the journal Colloids and Surfaces B: Biointerfaces. "Our results suggest this nanoparticle could potentially be used as an efficient therapeutic treatment for inflammation," said Didier Merlin, professor in the Institute for Biomedical Sciences at Georgia State and researcher at the Atlanta Veterans Affairs Medical Center. "We targeted CD98 because we determined in a previous study that CD98 is highly over-expressed in activated immune cells involved in IBD." In the United States, as many as 1.3 million people suffer from IBD, which includes ulcerative colitis and Crohn's disease, conditions with chronic or recurring abnormal response to the body's immune system and inflammation of the gastrointestinal tract. IBD gets worse over time and causes severe gastrointestinal symptoms, such as persistent diarrhea, cramping abdominal pain, fever, rectal bleeding, loss of appetite and weight loss. Surgery is required when medication can no longer control the symptoms, and patients also have an increased risk of colon cancer, according to the Centers for Disease Control and Prevention. This study suggests the development of nanotherapeutic strategies could be an alternative to currently available drugs, which are limited by serious side effects, in treating inflammatory conditions such as IBD. In the study, researchers formed the nanoparticles by combining CD98 siRNA, small interfering RNA that inhibit CD98 gene expression in macrophages (immune cells involved in IBD), with urocanic acid-modified chitosan (UAC). Chitosan is a polysaccharide obtained from the hard outer skeleton of shellfish. When introduced to macrophages, the nanoparticles had an anti-inflammatory effect on these immune cells. Researchers found the nanoparticles had a desirable particle size and no apparent toxicity against macrophages and colon epithelial cells. Cell studies showed nanoparticles with a weight ratio of 60:1 (UAC:siCD98) had the best anti-inflammatory capacity. ### Co-authors of the study include Emilie Viennois from the Institute for Biomedical Sciences at Georgia State and Atlanta Veterans Affairs Medical Center; Panpan Ma of Southwest University in Chongqing, China; and Bo Xiao from the Institute for Biomedical Sciences at Georgia State and Southwest University in Chongqing, China. The study was funded by the Department of Veterans Affairs, the National Institutes of Health's National Institute of Diabetes and Digestive and Kidney Diseases, and the National Natural Science Foundation of China. For more information, please click If you have a comment, please us. Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Home > Press > Nano-lipid particles from edible ginger could improve drug delivery for colon cancer, study finds Abstract: Edible ginger-derived nano-lipids created from a specific population of ginger nanoparticles show promise for effectively targeting and delivering chemotherapeutic drugs used to treat colon cancer, according to a study by researchers at the Institute for Biomedical Sciences at Georgia State University, the Atlanta Veterans Affairs Medical Center and Wenzhou Medical University and Southwest University in China. Colorectal cancer is the third most common cancer among men and women in the United States, and the second-leading cause of cancer-related deaths among men and women worldwide. The incidence of colorectal cancer has increased over the last few years, with about one million new cases diagnosed annually. Non-targeted chemotherapy is the most common therapeutic strategy available for colon cancer patients, but this treatment method is unable to distinguish between cancerous and healthy cells, leading to poor therapeutic effects on tumor cells and severe toxic side effects on healthy cells. Enabling chemotherapeutic drugs to target cancer cells would be a major development in the treatment of colon cancer. In this study, the researchers isolated a specific nanoparticle population from edible ginger (GDNP 2) and reassembled their lipids, naturally occurring molecules that include fats, to form ginger-derived nano-lipids, also known as nanovectors. To achieve accurate targeting of tumor tissues, the researchers modified the nanovectors with folic acid to create FA-modified nanovectors (FA nanovectors). Folic acid shows high-affinity binding to the folate receptors that are highly expressed on many tumors and almost undetectable on non-tumor cells. The FA nanovectors were tested as a delivery platform for doxorubicin, a chemotherapeutic drug used to treat colon cancer. The researchers found that doxorubicin was efficiently loaded into the FA nanovectors, and the FA nanovectors were efficiently taken up by colon cancer cells, exhibited excellent biocompatibility and successfully inhibited tumor growth. Compared to a commercially available option for delivering doxorubicin, the FA nanovectors released the drug more rapidly in an acidic pH that resembled the tumor environment, suggesting this delivery strategy could decrease the severe side effects of doxorubicin. These findings were published in the journal Molecular Therapy. "Our results show that FA nanovectors made of edible ginger-derived lipids could shift the current paradigm of drug delivery away from artificially synthesized nanoparticles toward the use of nature-derived nanovectors from edible plants," said Dr. Didier Merlin, a professor in the Institute for Biomedical Sciences at Georgia State and a Research Career Scientist at the VA Medical Center. "Because they are nontoxic and can be produced on a large scale, FA nanovectors derived from edible plants could represent one of the safest targeted therapeutic delivery platforms." ### Dr. Mingzhen Zhang of the Institute for Biomedical Sciences at Georgia State is the first author of the study. Co-authors of the study include Dr. Emilie Viennois, Dr. Zhan Zhang and Moon Kwon Han of the Institute for Biomedical Sciences at Georgia State; Dr. Bo Xiao of the Institute for Biomedical Sciences at Georgia State and Southwest University in Chonqing, China; and Dr. Changlong Xu of the Institute for Biomedical Sciences at Georgia State and Wenzhou Medical University in Wenzhou, China. The study was supported by the National Institute of Diabetes and Digestive and Kidney Diseases of the National Institutes of Health, the Department of Veterans Affairs and the Crohn's & Colitis Foundation of America. For more information, please click If you have a comment, please us. Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

News Article | April 8, 2016

​Nanoparticles designed to block a cell-surface molecule that plays a key role in inflammation could be a safe treatment for inflammatory bowel disease (IBD), according to researchers in the Institute for Biomedical Sciences at Georgia State University and Southwest University in China. The scientists developed nanoparticles, or microscopic particles, to reduce the expression of CD98, a glycoprotein that promotes inflammation. Their findings are published in the journal Colloids and Surfaces B: Biointerfaces. “Our results suggest this nanoparticle could potentially be used as an efficient therapeutic treatment for inflammation,” says Didier Merlin, professor in the Institute for Biomedical Sciences at Georgia State and researcher at the Atlanta Veterans Affairs Medical Center. “We targeted CD98 because we determined in a previous study that CD98 is highly over-expressed in activated immune cells involved in IBD.” In the U.S., as many as 1.3 million people suffer from IBD, which includes ulcerative colitis and Crohn’s disease, conditions with chronic or recurring abnormal response to the body’s immune system and inflammation of the gastrointestinal tract. IBD gets worse over time and causes severe gastrointestinal symptoms, such as persistent diarrhea, cramping abdominal pain, fever, rectal bleeding, loss of appetite, and weight loss. Surgery is required when medication can no longer control the symptoms, and patients also have an increased risk of colon cancer, according to the Centers for Disease Control and Prevention. This study suggests the development of nanotherapeutic strategies could be an alternative to currently available drugs, which are limited by serious side effects, in treating inflammatory conditions such as IBD. In the study, researchers formed the nanoparticles by combining CD98 siRNA, small interfering RNA that inhibit CD98 gene expression in macrophages (immune cells involved in IBD), with urocanic acid-modified chitosan (UAC). Chitosan is a polysaccharide obtained from the hard outer skeleton of shellfish. When introduced to macrophages, the nanoparticles had an anti-inflammatory effect on these immune cells. Researchers found the nanoparticles had a desirable particle size and no apparent toxicity against macrophages and colon epithelial cells. Cell studies showed nanoparticles with a weight ratio of 60:1 (UAC:siCD98) had the best anti-inflammatory capacity. Co-authors of the study include Emilie Viennois from the Institute for Biomedical Sciences at Georgia State and Atlanta Veterans Affairs Medical Center; Panpan Ma of Southwest University in Chongqing, China; and Bo Xiao from the Institute for Biomedical Sciences at Georgia State and Southwest University in Chongqing, China. The study was funded by the Department of Veterans Affairs, the National Institutes of Health’s National Institute of Diabetes and Digestive and Kidney Diseases, and the National Natural Science Foundation of China. Source: University of Georgia

Wen C.,Sichuan University | Xiaoming D.,Southwest University | Tao L.,Sichuan University | Tao Y.,Sichuan University
Knowledge-Based Systems | Year: 2014

Negative selection algorithm (NSA) is an important algorithm for the generation of artificial immune detectors. However, the randomly generated candidate detectors have to be compared with the whole self set to exclude self reactive detectors. The inefficiency of the comparing process seriously limited the application of immune algorithms. Therefore, a new negative selection algorithm GF-RNSA is proposed in the paper. Firstly, the feature space is divided into a number of grid cells, and then detectors are separately generated in each cell. As candidate detectors just need to compare with the self antigens located in the same cell rather than with the whole self set, the detector training can be more efficient. The theoretical analysis demonstrated that the time complexity of GF-RNSA is effectively reduced that the exponential relationships between self size and time complexity in traditional NSAs is eliminated. The experimental results showed that: not only the time cost of negative selection, but also the time cost of data preprocess and detection are reduced, while the detection accuracy is not much declined. © 2013 Elsevier B.V. All rights reserved.

Wu W.,University of New South Wales | Ao Z.,The Clean Tech Center | Wang T.,Zhejiang University | Li C.,Southwest University | Li S.,University of New South Wales
Physical Chemistry Chemical Physics | Year: 2014

An alternative approach for hydrogenation of silicene is proposed through applying an external electric field in order to reduce the reaction energy barrier based on density functional theory calculations. It is found that a positive perpendicular electric field F can act as a catalyst to reduce the energy barrier of H2 dissociative adsorption on silicene, which facilitates the hydrogenation of silicene. In addition, it is found that the barrier decreases as F increases, and when F is above 0.05 a.u. (1 a.u. = 5.14 × 1011 V m-1), the barrier is quite low and hydrogenation of silicene can take place efficiently at room temperature. The catalytic effect of the electric field on hydrogenation of silicene is induced by the redistribution of atomic charge under the electric field, which would change the chemical activity of silicene significantly. This journal is © the Partner Organisations 2014.

Li Y.,Southwest University | Wu Z.-M.,Southwest University | Zhong Z.-Q.,Southwest University | Yang X.-J.,Southwest University | And 3 more authors.
Optics Express | Year: 2014

Based on the framework of spin-flip model (SFM), the output characteristics of a 1550 nm vertical-cavity surface-emitting laser (VCSEL) subject to variable-polarization fiber Bragg grating (FBG) feedback (VPFBGF) have been investigated. With the aid of the self-correlation function (SF) and the permutation entropy (PE) function, the time-delay signature (TDS) of chaos in the VPFBGF-VCSEL is evaluated, and then the influences of the operation parameters on the TDS of chaos are analyzed. The results show that the TDS of chaos can be suppressed efficiently through selecting suitable coupling coefficient and feedback rate of the FBG, and is weaker than that of chaos generated by traditional variable-polarization mirror feedback VCSELs (VPMF-VCSELs) or polarization-preserved FBG feedback VCSELs (PPFBGF-VCSELs). © 2014 Optical Society of America.

Wu J.-G.,Southwest University | Wu Z.-M.,Southwest University | Wu Z.-M.,Nanjing Southeast University | Tang X.,Southwest University | And 3 more authors.
IEEE Photonics Technology Letters | Year: 2013

A fiber-optic chaos communication system for allowing bidirectional message transmission is first constructed and experimentally demonstrated. Using the synchronized chaos outputs of two authorized semiconductor lasers as communication carriers, two oppositely transmitted high frequency analog messages (3 and 4 GHz) can be encrypted and decrypted between two communication terminals over a 10-km single mode fiber channel. Furthermore, two data streams with bit rates of 2.5 Gb/s can also be bidirectionally encrypted and decrypted with bit-error-rates estimated below 10-4. © 1989-2012 IEEE.

Yang X.-B.,Southwest University | Wang Q.,Southwest University | Huang Y.,Ningxia Medical University | Fu P.-H.,Southwest University | And 2 more authors.
Inorganic Chemistry Communications | Year: 2012

Two novel copper (II) complexes 1 and 2 with Schiff base ligands derived from kaempferol and polyamines such as ethylenediamine and diethylenetriamine have been synthesized and characterized by elemental analysis, IR, UV-visible spectroscopy, 1H NMR, molar conductance measurements and molecular modeling studies. The interactions of complexes with DNA have been studied by absorption spectra, viscosity measurements and gel electrophoresis under physiological conditions. The experimental results indicated that two complexes could bind to CT-DNA via an intercalative mode. Noticeably, cleavage DNA (pUC 19) activity of the complex 2 is stronger than that of complex 1. The antimicrobial activities against Escherichia coli and Staphylococcus aureus of two complexes were evaluated by the minimum inhibition concentrations (MIC), which indicated that complex 2 possessed more active against E. coli. © 2012 Elsevier B.V.

Xie Y.,Southwest University | Xu J.,Hong Kong University of Science and Technology | Zhang J.,London South Bank University | Wu Z.,Southwest University | Xia G.,Southwest University
Journal of Lightwave Technology | Year: 2012

Crosstalk noise is an intrinsic characteristic of photonic devices used by optical router which is used in optical networks-on-chip. It also adds a new dimension to the design of the optical router based on the photonic devices. We analyzed crosstalk noise at device level and router level. Based on the detailed analysis, we proposed a general analytical model to study the transmission loss, crosstalk noise, optical signal-to-noise ratio (OSNR), and bit error ratio in the 5 × 5 hitless optical router. For the first time, this paper used the crossing angles of 60° or 120° instead of the conventional 90° crossing angle to design the optical router. It is obtained that by using this method OSNR is improved by about 10 dB. © 2006 IEEE.

Li M.-F.,Southwest University | Tang X.-P.,Shapingba Meteorological Bureau | Wu W.,Southwest University | Liu H.-B.,Southwest University
Energy Conversion and Management | Year: 2013

Abstract Empirical models, proposed to estimate solar radiation (Rs) in various areas, were site-specific in essence. However, it is questionable when they are applied to other stations where there is no record of Rs. This study aimed to develop general models to estimate daily Rs for different solar radiation zones in mainland China. Daily weather data including Rs, sunshine duration, relative humidity, maximum and minimum temperatures were collected and analyzed from 83 stations. Two types of simple empirical equations, namely, temperature- and sunshine-based models, were obtained for each site. Five Rs zones were determined by k-means clustering algorithm based on long-term mean daily Rs. For each zone, the general model for Rs estimation was developed based on geographical factors (latitude, longitude and altitude) and site-specific models. Coefficient of residual mass (CRM), mean bias error (MBE), mean percentage error (MPE), root mean square error (RMSE) and percent root mean square error (%RMSE) were used to investigate the model performance. The comparative results between measured and estimated daily Rs showed that the general models had an acceptable accuracy. It is believed that the general models developed in this work can be reliable and applicable for the locations without available Rs data in mainland China. © 2013 Elsevier Ltd. All rights reserved.

Yang X.-B.,Southwest University | Huang Y.,Ningxia Medical University | Zhang J.-S.,Guizhou Normal University | Yuan S.-K.,Southwest University | Zeng R.-Q.,Southwest University
Inorganic Chemistry Communications | Year: 2010

A series of copper (II) complexes a-d with Schiff bases ligands derived from the condensation reactions between 2-pyridinecarboxaldehyde and different polyamines (ethylenediamine, diethylenetriamine, triethylenetetramine and tetraethylenepentamine) were synthesized and characterized by elemental analysis, FT-IR spectroscopy, HRMS, molar conductance and molecular modeling studies. The interactions of the copper complexes a-d with DNA were investigated by the UV spectra, viscosity measurements and gel electrophoresis under physiological conditions. The experimental results indicated that four complexes could bind to DNA via an intercalative mode and showed a different DNA cleavage activity with the sequence: d > c > a > b. © 2010 Elsevier B.V. All rights reserved.

Bao H.-B.,Southwest University | Cao J.-D.,Nanjing Southeast University | Cao J.-D.,King Abdulaziz University
Neural Networks | Year: 2015

This paper investigates the projective synchronization of fractional-order memristor-based neural networks. Sufficient conditions are derived in the sense of Caputo's fractional derivation and by combining a fractional-order differential inequality. Two numerical examples are given to show the effectiveness of the main results. The results in this paper extend and improve some previous works on the synchronization of fractional-order neural networks. © 2014 Elsevier Ltd.

Wang Y.,Shaanxi Normal University | Qin Y.,Southwest University | Zhang Z.,Shaanxi Normal University | Zhang Z.,Southwest University
Plasmonics | Year: 2014

Optical transmission properties of periodic X-shaped plasmonic nanohole arrays in a silver film are investigated by performing the finite element method. Obvious peaks appear in the transmission spectra due to surface plasmon polaritons (SPPs) on the top surface of the silver film, to the Fabry–Ferot resonance effect of SPPs in the nanohole, and to the localized surface plasmon resonance of the nanohole. Besides the topologic shape parameters of the X-shaped nanohole, transmission properties strongly depend on incident polarization. The results of this study not only present a tunable plasmonic filter, but also aid in the understanding of the mechanisms of the extraordinary optical transmission phenomenon. © Springer Science+Business Media New York 2013.

Wu J.-G.,Southwest University | Wu J.-G.,University of Sichuan | Wu Z.-M.,Southwest University | Xia G.-Q.,Southwest University | And 2 more authors.
Optics Express | Year: 2012

In this paper, evolution of time delay (TD) signature of chaos generated in a mutual delay-coupled semiconductor lasers (MDC-SLs) system is investigated experimentally and theoretically. Two statistical methods, including self-correlation function (SF) and permutation entropy (PE), are used to estimate the TD signature of chaotic time series. Through extracting the characteristic peak from the SF curve, a series of TD signature evolution maps are firstly obtained in the parameter space of coupled strength and frequency detuning. Meantime, the influences of injection current on the evolution maps of TD signature have been discussed, and the optimum scope of TD signature suppression is also specified. An overall qualitative agreement between our theoretical and experimental results is obtained. © 2012 Optical Society of America.

Chen B.,Southwest University | Chen B.,Kunming University of Science and Technology | Huang Y.,Southwest University
Journal of Agricultural and Food Chemistry | Year: 2014

Dispersive liquid-phase microextraction with solidification of floating organic drop (SFO-DLPME) is one of the most interesting sample preparation techniques developed in recent years. In this paper, a new, rapid, and efficient SFO-DLPME coupled with high-performance liquid chromatography (HPLC) was established for the extraction and sensitive detection of banned Sudan dyes, namely, Sudan I, Sudan II, Sudan III, and Sudan IV, in foodstuff and water samples. Various factors, such as the type and volume of extractants and dispersants, pH and volume of sample solution, extraction time and temperature, ion strength, and humic acid concentration, were investigated and optimized to achieve optimal extraction of Sudan dyes in one single step. After optimization of extraction conditions using 1-dodecanol as an extractant and ethanol as a dispersant, the developed procedure was applied for extraction of the target Sudan dyes from 2 g of food samples and 10 mL of the spiked water samples. Under the optimized conditions, all Sudan dyes could be easily extracted by the proposed SFO-DLPME method. Limits of detection of the four Sudan dyes obtained were 0.10-0.20 ng g-1 and 0.03 μg L-1 when 2 g of foodstuff samples and 10 mL of water samples were adopted, respectively. The inter- and intraday reproducibilities were below 4.8% for analysis of Sudan dyes in foodstuffs. The method was satisfactorily used for the detection of Sudan dyes, and the recoveries of the target for the spiked foodstuff and water samples ranged from 92.6 to 106.6% and from 91.1 to 108.6%, respectively. These results indicated that the proposed method is simple, rapid, sensitive, and suitable for the pre-concentration and detection of the target dyes in foodstuff samples. © 2014 American Chemical Society.

Yao J.M.,Southwest University | Yao J.M.,Beijing University of Technology | Yao J.M.,Ludwig Maximilians University of Munich | Meng J.,Beijing University of Technology | And 3 more authors.
Physical Review C - Nuclear Physics | Year: 2010

The framework of relativistic energy-density functionals is extended to include correlations related to the restoration of broken symmetries and to fluctuations of collective variables. The generator coordinate method is used to perform configuration mixing of angular-momentum-projected wave functions, generated by constrained self-consistent relativistic mean-field calculations for triaxial shapes. The effects of triaxial deformation and of K mixing is illustrated in a study of spectroscopic properties of low-spin states in Mg24. © 2010 The American Physical Society.

Chuan Y.-M.,CAS Chengdu Institute of Organic Chemistry | Yin L.-Y.,Southwest University | Zhang Y.-M.,Southwest University | Peng Y.-G.,CAS Chengdu Institute of Organic Chemistry | Peng Y.-G.,Southwest University
European Journal of Organic Chemistry | Year: 2011

4-Aminothioureaprolinal dithioacetal 4a is a highly efficient catalyst for the asymmetric Michael addition of ketones and aldehydes to nitroolefins requiring only 3 mol-% catalyst loading. The reactions proceeded smoothly and gave syn selective adducts with excellent yields (up to 98a% yield), diastereoselectivity (up to >99:1adr), and enantioselectivity (up to 99a%aee) under solvent free conditions at room temperature. This extremely simple and practical procedure increases the attractiveness of this reaction. 4-Aminothioureaprolinal dithioacetal 4a is a highly efficient catalyst for asymmetric Michael additions of ketones and aldehydes to nitroolefins. Using only 3 mol-% catalyst loading, reactions proceededsmoothly and gave syn selective adducts in excellent yields with excellent diastereoselectivity and enantioselectivity under solvent-free conditions at room temperature. © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Miao H.,Southwest University | Zhong D.,Southwest University | Zhou Z.,University of Pennsylvania | Yang X.,Southwest University
Nanoscale | Year: 2015

Herein, papain-functionalized Cu nanoclusters (CuNCs@Papain) were originally synthesized in aqueous solution together with a quantum yield of 14.3%, and showed obviously red fluorescence at 620 nm. Meanwhile, their corresponding fluorescence mechanism was fully elucidated by fluorescence spectroscopy, HR-TEM, FTIR spectroscopy, and XPS. Subsequently, the as-prepared CuNCs were employed as probes for detecting H2O2. Using CuNCs as probes, H2O2 was determined in the range from 1 μM to 50 μM based on a linear decrease of fluorescence intensity as well as a detection limit of 0.2 μM with a signal-to-noise ratio of 3. More significantly, it has been proved that CuNCs could convert H2O2 to OH, which exhibited dramatic antibacterial activity. Both in vitro and in vivo experiments were performed to validate their antibacterial activity against Gram-positive/negative bacteria and actual wound infection, suggesting their potential for serving as one type of promising antibacterial material. © 2015 The Royal Society of Chemistry.

Jackson T.,Southwest University | Wang Y.,Southwest University | Fan H.,Bohai University
Journal of Pain | Year: 2014

In this research, meta-analyses were performed to evaluate associations between primary appraisals of pain as a source of threat and/or challenge and responses to 1) noxious laboratory stimuli and 2) chronic noncancer pain. Twenty-two laboratory pain studies comprising 2,031 participants and 59 chronic pain studies based on 9,135 patients were identified for analysis. For laboratory pain, elevated threat appraisals were linked to overall increases in reported pain, reduced pain tolerance, and high levels of passive coping. Method of measuring appraisal as well as type and duration of noxious stimulation moderated some of these associations. Challenge appraisals were related to more pain tolerance and less passive coping but not pain intensity. For chronic pain studies, threat appraisals had positive overall correlations with pain intensity, impairment, affective distress, and passive coping but were negatively related to active coping. The pattern of associations between challenge appraisals and outcomes was largely complementary. Appraisal scale used and gender were consistent moderators of appraisal-outcome relations in chronic pain samples. In sum, appraisals of pain as a source of potential damage or opportunity have robust associations with responses to acute laboratory pain and ongoing chronic pain. Perspective Meta-analyses evaluated associations between primary appraisals and responses to laboratory pain and chronic pain. Significant effect sizes for most outcomes suggest that appraisals of pain as a source of threat and challenge have important implications for functioning in response to pain. © 2014 by the American Pain Society. Published by Elsevier Inc. All rights reserved.

Zhang H.-F.,Military School of Engineering | Sun Z.,Chongqing University | Sang W.-L.,Southwest University | Sang W.-L.,CAS Institute of Theoretical Physics | Li R.,Xi'an Jiaotong University
Physical Review Letters | Year: 2015

With the recent LHCb data on ηc production and based on heavy quark spin symmetry, we obtain the long-distance matrix elements for both ηc and J/ψ productions, among which, the color-singlet one for ηc is obtained directly by the fit of experiment for the first time. Using our long-distance matrix elements, we can provide good description of the ηc and J/ψ hadroproduction measurements. Our predictions on J/ψ polarization are in good agreement with the LHCb data, explain most of the CMS data, and pass through the two sets of CDF measurements in the medium pt region. Considering all the possible uncertainties carefully, we obtained quite narrow bands of the J/ψ polarization curves. © 2015 American Physical Society.

Sun K.,Southwest University | Park K.,Virginia Polytechnic Institute and State University | Xie J.,Southwest University | Luo J.,Southwest University | And 4 more authors.
ACS Nano | Year: 2013

Single-molecule nanomagnets have unique quantum properties, and their potential applications require characterization and accessibility of individual single-molecule magnets on various substrates. We develop a gentle tip-deposition method to bring individual prototype single-molecule magnets, manganese-12-acetate (Mn12) molecules, onto the semimetallic Bi(111) surface without linker molecules, using low-temperature scanning tunneling microscopy. We are able to identify both the almost flat-lying and side-lying orientations of Mn12 molecules at 4.5 K. Energy-resolved spectroscopic mapping enables the first observation of several molecular orbitals of individual Mn12 molecules in real space, which is consistent with density functional theory calculations. Both experimental and theoretical results suggest that an energy gap between the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) of the almost flat-lying Mn12 is only 40% of such a gap for an isolated (free) Mn12 molecule, which is caused by charge transfer from the metallic surface states of Bi to the Mn12. Despite the reduction of this gap, STM images show that the local lattices of Bi(111) covered with Mn12 remain essentially intact, indicating that Mn12-Bi interactions are not strong. Our findings open an avenue to address directly the local structural and electronic properties of individual single-molecule magnets on solid substrates. © 2013 American Chemical Society.

Gao C.,Southwest University | Gao C.,Jilin University | Liu J.,Hong Kong Baptist University
PLoS ONE | Year: 2015

In response to an extreme event, individuals on social media demonstrate interesting behaviors depending on their backgrounds. By making use of the large-scale datasets of posts and search queries collected from Twitter and GoogleTrends, we first identify the distinct categories of human collective online concerns and durations based on the distributions of solo tweets and new incremental tweets about events. Such a characterization enables us to gain a better understanding of dynamic changes in human behaviors corresponding to different types of events. Next, we observe the heterogeneity of individual responses to events through measuring the fraction of event-related tweets relative to the tweets released by an individual, and thus empirically confirm the heterogeneity assumption as adopted in the meta-population models for characterizing collective responses to events. Finally, based on the correlations of information entropy in different regions, we show that the observed distinct responses may be caused by their different speeds in information propagation. In addition, based on the detrended fluctuation analysis, we find that there exists a self-similar evolution process for the collective responses within a region. These findings have provided a detailed account for the nature of distinct human behaviors on social media in presence of extreme events. © 2015 Gao, Liu This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Chen P.,Jilin University | Huang J.,Southwest University | Xiong Z.,Southwest University | Li F.,Jilin University
Organic Electronics: physics, materials, applications | Year: 2013

By investigating the turn-on and turn-off photovoltage dynamics as a function of aging time, we reported the roles of traps on the energy loss in organic solar cells composing of copper phthalocyanine (CuPc)/fullerene (C60). Illuminating the device with square pulses of light, a peak of transient photovoltage after turn-on was observed after device degradation. After turn-off, the transient photovoltage first goes to the negative before settling back to zero, which is the result of electron trapping in the C60 layer before being neutralized by re-injected holes. Furthermore, by adding a tris (8-hydroxyquinolinato) aluminum buffer to prevent the traps from propagating into C60 layer, the peak after turn-on is greatly suppressed and the negative peak after turn-off vanishes, supporting the trapped electrons in the C60 layer play the critical role in the appearance of peak of the transient photovoltage. © 2012 Elsevier B.V. All rights reserved.

Xia Y.,Georgia Institute of Technology | Xia X.,Georgia Institute of Technology | Wang Y.,Southwest University | Xie S.,Xiamen University
MRS Bulletin | Year: 2013

The ability to control the shape of metal nanocrystals is central to advances in many areas of modern science and technology, including catalysis, plasmonics, electronics, and biomedicine. This article provides a brief overview of our recent efforts toward the development of solution-phase methods for shape-controlled synthesis of metal nanocrystals. While the synthetic methods only involve simple redox reactions, we have been working diligently to understand the complex nucleation and growth mechanisms leading to the formation of metal nanocrystals with desired shapes and related properties. We hope this review will inspire new ideas and concepts in the general area of nanomaterial synthesis, expand our ability to engineer the properties of metals for various applications, and contribute to the realization of sustainable use for some of the scarcest materials. © 2013 Materials Research Society.

Jackson T.,Southwest University | Wang Y.,Southwest University | Fan H.,Bohai University
Journal of Pain | Year: 2014

A meta-analysis was performed to evaluate overall strengths of relation between self-efficacy (SE) and functioning (pain severity, functional impairment, affective distress) in chronic pain samples, as well as potential moderating effects of sociodemographic characteristics and methodologic factors on these associations. In sum, 86 samples (N = 15,616) fulfilled selection criteria for analysis. SE had negative overall correlations with impairment, affective distress, and pain severity although considerable heterogeneity was observed for all effect sizes. Age, pain duration, SE scale content (SE for functioning despite pain vs SE for pain control vs SE for managing other symptoms such as emotional distress) and type of impairment measure (self-report vs task performance) had significant moderating effects on SE-impairment associations. SE-affective distress relations were moderated by employment status and SE scale content. Finally, moderator analyses of studies having longitudinal designs indicated associations between baseline SE, and each outcome at follow-up remained significant in prospective studies that had statistically controlled for effects of baseline responses on that outcome. Hence, SE is a robust correlate of key outcomes related to chronic pain and a potentially important risk/protective factor that has implications for subsequent functioning in affected groups. Perspective Meta-analysis indicated that SE has significant overall associations with impairment, affective distress, and pain severity within chronic pain samples and identified several factors that contribute to variability in effect sizes. Findings highlighted SE as a robust correlate and potentially important risk/protective factor for subsequent adjustment in affected groups. © 2014 by the American Pain Society.

Xu B.,Southwest University | Shi L.-L.,Southwest University | Zhang Y.-Z.,Southwest University | Wu Z.-J.,CAS Chengdu Institute of Biology | And 5 more authors.
Chemical Science | Year: 2014

Two types of BINOL-related chiral aldehydes were used as organocatalysts for the direct α-functionalization of N-unprotected amino esters. The first chiral aldehyde catalysed α-alkylation of 2-aminomalonates with 3-indolylmethanols via imine activation was reported. Various tryptophan derivatives were produced in good yields and with high enantioselectivities. A reasonable mechanism was proposed and the core intermediates were identified by high resolution mass spectroscopy (HRMS). © 2014 the Partner Organisations.

Wu X.Y.,Southwest University | Yao J.M.,Southwest University | Yao J.M.,Tohoku University | Li Z.P.,Southwest University
Physical Review C - Nuclear Physics | Year: 2014

The low-energy structure of 46Ar is of particular interest due to the possible coexistence of different shapes and the possible existence of proton "bubble" structures. In this work, we apply a beyond relativistic mean-field approach to study the low-energy structure of 46Ar. Correlations beyond the mean field are introduced by configuration mixing of both particle-number and angular-momentum projected axially deformed mean-field states. The low-lying spectroscopy and charge density in a laboratory frame are calculated and an excellent agreement with available data is achieved. Even though an evident proton bubble structure is shown in the spherical state of 46Ar, it eventually disappears after taking into account the dynamical correlation effects. Moreover, our results indicate that the existence of a proton bubble structure in argon isotopes is unlikely. © 2014 American Physical Society.

Hagino K.,Tohoku University | Hagino K.,Japan National Astronomical Observatory | Yao J.M.,Tohoku University | Yao J.M.,Southwest University
Physical Review C - Nuclear Physics | Year: 2015

We describe low-lying collective excitations of atomic nuclei with the multireference covariant density functional theory and combine them with coupled-channels calculations for heavy-ion fusion reactions at energies around the Coulomb barrier. To this end, we use the calculated transition strengths among several collective states as inputs to the coupled-channels calculations. This approach provides a natural way to describe anharmonic multiphonon excitations, as well as a deviation of rotational excitations from a simple rigid rotor. We apply this method to subbarrier fusion reactions of Ni58+Ni58,Ni58+Ni60, and Ca40+Ni58 systems. We find that the effect of anharmonicity tends to smear the fusion barrier distributions, better reproducing the experimental data compared to the calculations in the harmonic oscillator limit. © 2015 American Physical Society.

Yao J.M.,Southwest University | Yao J.M.,Tohoku University | Zhou E.F.,Southwest University | Li Z.P.,Southwest University
Physical Review C - Nuclear Physics | Year: 2015

We report the first beyond-mean-field study of low-lying parity-doublet states in Ra224 by extending the multireference relativistic energy density functional method to include dynamical correlations related to symmetry restoration and quadrupole-octupole shape fluctuation with a generator coordinate method combined with parity, particle-number, and angular-momentum projections. We clarify microscopically that the origin of spin-dependent parity splitting in low-spin states is related to the octupole shape stabilization of positive-parity states, the shapes of which drift gradually toward those of negative-parity ones. © 2015 American Physical Society. ©2015 American Physical Society.

Yuan Y.,Southwest University | Gou X.,Sun Yat Sen University | Yuan R.,Southwest University | Chai Y.,Southwest University | And 3 more authors.
Biosensors and Bioelectronics | Year: 2011

A simple electrochemical aptasensor for sensitive detection of thrombin was fabricated with G-quadruplex horseradish peroxidase-mimicking DNAzyme (hemin/G-quadruplex system) and blocking reagent-horseradish peroxidase as dual signal-amplification scheme. Gold nanoparticles (nano-Au) were firstly electrodeposited onto single wall nanotube (SWNT)-graphene modified electrode surface for the immobilization of electrochemical probe of nickel hexacyanoferrates nanoparticles (NiHCFNPs). Subsequently, another nano-Au layer was electrodeposited for further immobilization of thrombin aptamer (TBA), which later formed hemin/G-quadruplex system with hemin. Horseradish peroxidases (HRP) then served as blocking reagent to block possible remaining active sites and avoided the non-specific adsorption. In the presence of thrombin, the TBA binded to thrombin and the hemin released from the hemin/G-quadruplex electrocatalytic structure, increasing steric hindrance of the aptasensor and decomposing hemin/G-quadruplex electrocatalytic structure, which finally decreased the electrocatalytic efficiency of aptasensor toward H 2O 2 in the presence of NiHCFNPs with a decreased electrochemical signal. On the basis of the synergistic amplifying action, a detection limit as low as 2 pM for thrombin was obtained. © 2011 Elsevier B.V.

Ren L.,Hohai University | Xiang X.-Y.,Southwest University | Ni J.-J.,Hohai University
Journal of Hydrologic Engineering | Year: 2013

There is no real periodicity in the changes of hydrological systems. Changes in a hydrological system take place with different periodic variations from time to time. In this paper, a new method was utilized to predict monthly runoff with a wavelet analysis technique. Taking advantage of localized characteristics of wavelet transform and the approximation function of an adaptive neural fuzzy inference system (ANFIS), the combined approach of wavelet transform and ANFIS was used to predict monthly runoff. The ANFIS forecast model for monthly runoff was established based on wavelet analysis. To solve the problems related to the large amplitudes of intra- and interannual variation of monthly runoff, a resolving and reconstructing technique of wavelets was utilized to decompose runoff series into different information subspaces, by which decomposition signals with different frequencies were obtained. Based on the evaluation of simulated and measured values in Yichang Station, it was found that the percent of the pass of relative error was 100% and the effect of prediction was acceptable. The certainty factor, dy, was 0.91 and the prediction level was A. By comparing the measured and predicted values, it was found that with this model, the trend of originals could be forecasted, but improvements are still needed. Because the new model is sensitive to sudden changes in rainfall, combined with the irregular monthly runoff variation, it is difficult to forecast runoff with this model, which should be improved in the future. © 2013 American Society of Civil Engineers.

Wang W.,Southwest University | Liu G.,Chinese Academy of Agricultural Sciences | Niu H.,Southwest University | Timko M.P.,University of Virginia | Zhang H.,Southwest University
Journal of Experimental Botany | Year: 2014

Jasmonate (JA) plays an important role in regulating plant male fertility and secondary metabolism, but its role in regulating primary metabolism remains unclear. The F-box protein CORONATINE INSENSITIVE 1 (COI1) is a critical component of the JA receptor, and mediates JA-signalling by targeting JASMONATE ZIM-domain (JAZ) proteins for proteasomal degradation in response to JA perception. Here, we found that RNA interference-mediated knockdown of NtCOI1 in tobacco (Nicotiana tabacum L. cv. TN90) recapitulated many previously observed phenotypes in coi1 mutants, including male sterility, JA insensitivity, and loss of floral anthocyanin production. It also affected starch metabolism in the pollen, anther wall, and floral nectary, leading to pollen abortion and loss of floral nectar. Transcript levels of genes encoding starch metabolism enzymes were significantly altered in the pollen, anther wall, and floral nectary of NtCOI1-silenced tobacco. Changes in leaf primary metabolism were also observed in the NtCOI1-silenced tobacco. The expression of NtMYB305, an orthologue of MYB305 previously identified as a flavonoid metabolic regulator in Antirrhinum majus flowers and as a floral-nectar regulator mediating starch synthesis in ornamental tobacco, was extremely downregulated in NtCOI1-silenced tobacco. These findings suggest that NtCOI1 functions upstream of NtMYB305 and plays a fundamental role in coordinating plant primary carbohydrate metabolism and correlative physiological processes. © The Author 2014. Published by Oxford University Press on behalf of the Society for Experimental Biology.

Nayak M.K.,Fisheries and Forestry | Nayak M.K.,Plant Biosecurity Cooperative Research Center | Collins P.J.,Fisheries and Forestry | Collins P.J.,Plant Biosecurity Cooperative Research Center | And 2 more authors.
Annual Review of Entomology | Year: 2014

Previously regarded as minor nuisance pests, psocids belonging to the genus Liposcelis now pose a major problem for the effective protection of stored products worldwide. Here we examine the apparent biological and operational reasons behind this phenomenon and why conventional pest management seems to be failing. We investigate what is known about the biology, behavior, and population dynamics of major pest species to ascertain their strengths, and perhaps find weaknesses, as a basis for a rational pest management strategy. We outline the contribution of molecular techniques to clarifying species identification and understanding genetic diversity. We discuss progress in sampling and trapping and our comprehension of spatial distribution of these pests as a foundation for developing management strategies. The effectiveness of various chemical treatments and the availability and potential of nonchemical control methods are critically examined. Finally, we identify research gaps and suggest future directions for research. © Copyright ©2014 by Annual Reviews. All rights reserved.

Gao G.,Southwest University | Xu J.,Jilin University
Critical Reviews in Eukaryotic Gene Expression | Year: 2013

Brucellosis caused by Brucella spp. is a common zoonosis in many parts of the world. Humans are infected through contact with infected animals or their dirty products. Many mechanisms are needed for this successful infection, although the mechanisms are still unclear. Host immune response and some signaling molecules play an important role in the infection event. Bacterial pathogens operate by attacking crucial intracellular pathways or some important molecules in each of these pathways for survival in their hosts. The crucial components (molecules) of immunity or pathway play a critical role in the whole process of Brucella infection. Here we summarize the findings of the Brucella-host interactions' immune system and signaling molecular cascades involved in the TLR-initiated immune response to Brucella spp. infection. The paper serves to deepen our understanding of this complex process and to provide some clues regarding the discovery of drug targets for prevention and control. © 2013 Begell House, Inc.

Chen W.,Southwest University | Deng S.,Southwest University | Deng S.,University of Chile
Zeitschrift fur Angewandte Mathematik und Physik | Year: 2015

In this paper, we study the multiplicity of solutions to equations driven by a nonlocal integro-differential operator LK with homogeneous Dirichlet boundary conditions. In particular, using fibering maps and Nehari manifold, we obtain multiple solutions to the following fractional elliptic problem (Formula Presented.) is a smooth bounded set in Rn, n >  2s with s∈(0,1), λ is a positive parameter, the exponents p and q satisfy (Formula Presented.). © 2014, Springer Basel.

Deng X.,Southwest University | Hu Y.,Sun Yat Sen University | Deng Y.,Southwest University | Deng Y.,Vanderbilt University | Mahadevan S.,Vanderbilt University
Expert Systems with Applications | Year: 2014

Environmental impact assessment (EIA) is a complex problem influenced by many aspects, such as environmental, social, economic, etc. Due to the involvement of human judgment, various uncertainties are introduced in the EIA process. One critical issue of EIA is the representation and handling of uncertain information. Many different theories are available to deal with uncertainty, however, deficiencies exist in these theories. In this paper, based on a more effective representation of uncertainty, called D numbers, a new method is proposed for the EIA problem. In the proposed method, the assessment results of environmental impacts are expressed and modeled by D numbers. An illustrative case is provided to demonstrate the effectiveness of the proposed method. © 2013 Elsevier Ltd. All rights reserved.

Deng X.,Southwest University | Hu Y.,Sun Yat Sen University | Deng Y.,Southwest University | Deng Y.,Vanderbilt University | Mahadevan S.,Vanderbilt University
Expert Systems with Applications | Year: 2014

Supplier selection is an important issue in supply chain management (SCM), and essentially is a multi-criteria decision-making problem. Supplier selection highly depends on experts' assessments. In the process of that, it inevitably involves various types of uncertainty such as imprecision, fuzziness and incompleteness due to the inability of human being's subjective judgment. However, the existing methods cannot adequately handle these types of uncertainties. In this paper, based on a new effective and feasible representation of uncertain information, called D numbers, a D-AHP method is proposed for the supplier selection problem, which extends the classical analytic hierarchy process (AHP) method. Within the proposed method, D numbers extended fuzzy preference relation has been involved to represent the decision matrix of pairwise comparisons given by experts. An illustrative example is presented to demonstrate the effectiveness of the proposed method. © 2013 Elsevier Ltd. All rights reserved.

Cui H.-J.,Chinese Institute of Urban Environment | Cui H.-J.,CAS Nanjing Institute of Soil Science | Wang M.K.,National Taiwan University | Fu M.-L.,Chinese Institute of Urban Environment | Ci E.,Southwest University
Journal of Soils and Sediments | Year: 2011

Purpose: Biochar amendments can alter phosphorus (P) availability in soils, though the influencing mechanisms are not yet fully understood. This work investigated the adsorption and desorption of P on ferrihydrite (F, a Fe-oxide widely distributed in surface environments) in order to evaluate the interactions between P and Fe-oxide in the absence or presence of biochar (F or ferrihydrite-biochar (F-B) interaction) in soils. Materials and methods: Biochar was produced by pyrolysis of rice straw at 600°C in steel ring furnaces. Two-line ferrihydrite was synthesized by dropwise addition of 1 mol L-1 KOH into Fe(NO3)3 solution until the pH reached 7-8 while stirring vigorously. An F-B complex was prepared under similar conditions, except that a mixture of 10 g biochar and the Fe(NO3)3 solution was used as the starting material instead of Fe(NO3)3 alone. A batch equilibration method was used to determine sorption or desorption of P. The mechanisms of P adsorption on F and F-B complex materials were discussed. Results and discussion: Adsorption of P on F decreased as the pH was increased from 3.0 to 10, but the adsorption capacity of F decreased by about 30-40% in the presence of biochar. The P chemisorption rates on F also decreased in the presence of biochar. The Freundlich model showed that the active adsorption sites on the surface of the F-B complex were energetically heterogeneous. The desorbability of adsorbed P on F was enhanced by combination with biochar. The mechanisms of P adsorption on F and F-B complex materials are different. Conclusions: The results showed that the amount and rate of P adsorption on the surface of ferrihydrite decreased with the presence of biochar, and the desorbability of adsorbed P on ferrihydrite can be enhanced when combined with biochar. Thus, the presence of biochar can decrease P adsorption on the Fe-oxides and enhance P availability in soils. © 2011 Springer-Verlag.

Lan C.,University of Electronic Science and Technology of China | Gong J.,Hohai University | Jiang Y.,Southwest University
Journal of Alloys and Compounds | Year: 2013

String-like ZnO/SnO nanowire/nanosheet nano-heterostructures were synthesized by a two-stage vapor transport and condensation method. ZnO nanowire backbones and SnO nanosheets were single crystalline. Several pieces of SnO nanosheets were threaded by a single ZnO nanowire, forming string-like nanoheterostructures. A preliminary growth model was proposed to explain the formation of the nano-heterostructures. PL measurements showed the band related emission of ZnO had a blue shift for ZnO/SnO nano-heterostructures, which was due to the doping of Sn in ZnO nanowires. A broad emission ranging from 450 to 730 nm of the ZnO/SnO nano-heterostructures might be related to defects in both ZnO nanowires and SnO nanosheets. This special nanostructure may find applications in gas sensors, photodetectors, etc. © 2013 Elsevier B.V. All rights reserved.

Li G.-F.,Hohai University | Xiang X.-Y.,Southwest University | Tong Y.-Y.,China Institute of Water Resources and Hydropower Research | Wang H.-M.,Hohai University
Stochastic Environmental Research and Risk Assessment | Year: 2013

The Yangtze River Delta region is the region with highest urbanization speed in China. In this study, 6 typical urbanization areas in Yangtze River Delta were selected as the objectives of study. Flood risk assessment index system was established based on the flood disaster formation mechanism, and analytic hierarchy process was utilized to define the weight of indices. The flood hazard, the exposure of disaster bearing body, the vulnerability of disaster bearing body and the comprehensive flood risk corresponding to three typical years in different urbanization stages, 1991, 2001 and 2006 were assessed. The results show that the flood hazard and the exposure of disaster bearing body in the 6 areas are all with an increasing trend in the process of urbanization, among which, the increasing trend of the exposure of disaster bearing body is especially obvious. Though the vulnerabilities of disaster bearing body in the 6 areas are all with decreasing trend owe to the enhancement of flood control and disaster mitigation capability, the comprehensive flood risks in the 6 areas increased as a whole, which would pose a serious threat to urban sustainable development. Finally, effective countermeasures for flood risk management of urbanization areas in Yangtze River Delta were put forward based on the assessment results. © 2013 Springer-Verlag Berlin Heidelberg.

Chen L.Q.,ECO International | Fang L.,ECO International | Ling J.,Yunnan University | Ding C.Z.,ECO International | And 2 more authors.
Chemical Research in Toxicology | Year: 2015

Silver nanoparticles (AgNPs) are increasingly being used as antimicrobial agents and drug carriers in biomedical fields. However, toxicological information on their effects on red blood cells (RBCs) and the mechanisms involved remain sparse. In this article, we examined the size dependent nanotoxicity of AgNPs using three different characteristic sizes of 15 nm (AgNPs15), 50 nm (AgNPs50), and 100 nm (AgNPs100) against fish RBCs. Optical microscopy and transmission electron microscopy observations showed that AgNPs exhibited a size effect on their adsorption and uptake by RBCs. The middle sized AgNPs50, compared with the smaller or bigger ones, showed the highest level of adsorption and uptake by the RBCs, suggesting an optimal size of ∼50 nm for passive uptake by RBCs. The toxic effects determined based on the hemolysis, membrane injury, lipid peroxidation, and antioxidant enzyme production were fairly size and dose dependent. In particular, the smallest sized AgNPs15 displayed a greater ability to induce hemolysis and membrane damage than AgNPs50 and AgNPs100. Such cytotoxicity induced by AgNPs should be attributed to the direct interaction of the nanoparticle with the RBCs, resulting in the production of oxidative stress, membrane injury, and subsequently hemolysis. Overall, the results suggest that particle size is a critical factor influencing the interaction between AgNPs and the RBCs. © 2015 American Chemical Society.

Wang D.,Southwest University | Wang D.,Cornell University | Xin H.L.,Cornell University | Wang H.,Cornell University | And 5 more authors.
Chemistry of Materials | Year: 2012

The rational synthesis of active, durable, and low-cost catalysts is of particular interest to fuel cell applications. Here, we describe a facile method for the preparation of Pd-rich Pd xCo alloy nanoparticles supported on carbon, using an adsorbate-induced surface segregation effect. The electronic properties of Pd were modulated by alloying with different amounts of Co, which affects the oxygen reduction reaction (ORR) activity. The electrocatalytic activity of the Pd 3Co@Pd/C nanoparticles for the ORR was enhanced by spontaneously depositing a nominal monolayer of Pt. The activities of the different catalysts for the ORR could be correlated with the oxygen adsorption energy and the d-band center of the catalyst surface, as calculated using density functional theory, which is in agreement with previous theoretical studies. The materials synthesized herein are promising cathode catalysts for fuel cell applications and the facile synthesis method could be readily adapted to other catalyst systems, facilitating screening of high efficiency catalysts. © 2012 American Chemical Society.

Shi L.-B.,Bohai University | Yuan H.-K.,Southwest University
Journal of Magnetism and Magnetic Materials | Year: 2011

By using the first principle method based on density functional theory (DFT), a study on the electronic structure and the ferromagnetic stability in C-doped (1 1 2̄ 0) ZnO thin films was conducted. It was found that the thin films have a FM ground state for a majority of configurations. It was also found that C atoms in the thin films have a clear clustering tendency. The ferromagnetism (FM) can be attributed to the coupling between C energy levels. The results showed that oxygen vacancies cannot stabilize the FM coupling of C-doped ZnO thin films. However, zinc vacancies can stabilize the FM coupling of the thin films, which indicates that hole-carriers play a crucial role in the observed FM behavior. In addition, the strain effect on the FM of C-doped ZnO thin films was also analyzed. © 2010 Elsevier B.V. All rights reserved.

Shi L.B.,Bohai University | Xu C.Y.,Liaoning University of Technology | Yuan H.K.,Southwest University
Physica B: Condensed Matter | Year: 2011

The CASTEP calculations based on the density function theory (DFT) have been carried out in studying magnetic properties of C-doped ZnO crystal. The long-range ferromagnetism (FM) can be attributed to coupling between C energy levels. We also investigate effects of oxygen vacancies and nitrogen impurities on FM properties. It is obvious that oxygen vacancies are unfavorable to stabilize the FM. However, nitrogen impurities can enhance FM coupling, which indicates that hole-carriers play a crucial role in the observed FM behavior. In addition, we also analyze strain effect on FM of C-doped ZnO. © 2011 Elsevier B.V. All rights reserved.

Sun B.,Southwest University | Sun B.,Chongqing Key Laboratory for Advanced Materials and Technologies of Clean Energies | Li C.M.,Southwest University | Li C.M.,Chongqing Key Laboratory for Advanced Materials and Technologies of Clean Energies
Physical Chemistry Chemical Physics | Year: 2015

A multiferroic BiMnO3 nanowire array was prepared using a hydrothermal process and its resistive switching memory behaviors were further investigated. The prominent ferroelectricity can be well controlled by white-light illumination, thus offering an excellent light-controlled resistive switching memory device using a Ag/BiMnO3/Ti structure at room temperature. This journal is © the Owner Societies.

Fan Y.,Southwest University | Fan Y.,University of Florida | Pereira R.M.,University of Florida | Kilic E.,University of Florida | And 2 more authors.
PLoS ONE | Year: 2012

Fire ants are one of the world's most damaging invasive pests, with few means for their effective control. Although ecologically friendly alternatives to chemical pesticides such as the insecticidal fungus Beauveria bassiana have been suggested for the control of fire ant populations, their use has been limited due to the low virulence of the fungus and the length of time it takes to kill its target. We present a means of increasing the virulence of the fungal agent by expressing a fire ant neuropeptide. Expression of the fire ant (Solenopsis invicta) pyrokinin β -neuropeptide (β-NP) by B. bassiana increased fungal virulence six-fold towards fire ants, decreased the LT 50, but did not affect virulence towards the lepidopteran, Galleria mellonella. Intriguingly, ants killed by the β-NP expressing fungus were disrupted in the removal of dead colony members, i.e. necrophoretic behavior. Furthermore, synthetic C-terminal amidated β-NP but not the non-amidated peptide had a dramatic effect on necrophoretic behavior. These data link chemical sensing of a specific peptide to a complex social behavior. Our results also confirm a new approach to insect control in which expression of host molecules in an insect pathogen can by exploited for target specific augmentation of virulence. The minimization of the development of potential insect resistance by our approach is discussed. © 2012 Fan et al.

Yuan W.,Southwest University | Lu Z.,Southwest University | Lu Z.,Chongqing Key Laboratory for Advanced Materials and Technologies of Clean Energies | Li C.M.,Southwest University | Li C.M.,Chongqing Key Laboratory for Advanced Materials and Technologies of Clean Energies
Journal of Materials Chemistry A | Year: 2013

It is very challenging to assemble microscale objects on a macroscale substrate due to the weak interaction and size/geometric mismatch. Herein a novel polyelectrolyte-mediated self-assembly approach with microsized ZnO nanoflowers as building blocks was successfully used to grow a hierarchical nanostructure on a substrate, which is mainly due to the loop and tail conformation of the weak polyelectrolyte used. Furthermore, a heating step was able to enhance the self-assembly process. The obtained ZnO flower hierarchical nanostructure possesses simultaneous non-light induced superhydrophilic, antifogging and antibacterial properties, thus providing great potential in applications such as biomedical devices, hospital building paints, and daily life uses. This demonstrated method could be extended to fabricate hierarchical nanostructures with other microscale nanostructured materials on various substrates for broad applications. This journal is © The Royal Society of Chemistry 2013.

Cui Z.,Nanyang Technological University | Guo C.X.,Southwest University | Guo C.X.,Chongqing Key Laboratory for Advanced Materials and Technologies of Clean Energies | Li C.M.,Southwest University | Li C.M.,Chongqing Key Laboratory for Advanced Materials and Technologies of Clean Energies
Journal of Materials Chemistry A | Year: 2013

Graphene sheets are modified by self-assembly of phosphomolybdic acid followed by in situ formation of polyaniline (PANI-HPMo-GS) to uniformly deposit small nanoparticles of Pt catalyst (∼3 nm) by interaction between PANI and PtCl6 2-. The Pt/PANI-HPMo-GS material exhibits significantly enhanced electrocatalytic activity (322 mA mg-1 Pt) and high stability (voltage degradation rate of 60 mV h-1 at a constant load of 4 mA cm-2 and peak current reduces by 22.7% after 100 voltammetry cycles) for methanol oxidation. This self-assembly strategy can be readily extended to the fabrication of other carbon based hybrid supports for precious metal catalysts for various applications. © 2013 The Royal Society of Chemistry.

Zhang J.,Nanyang Technological University | Li C.M.,Nanyang Technological University | Li C.M.,Southwest University | Li C.M.,Chongqing Key Laboratory for Advanced Materials and Technologies of Clean Energies
Chemical Society Reviews | Year: 2012

Nanoporous metals, a representative type of nanostructured material, possess intriguing properties to generate enormously promising potentials for various important applications. In particular, with the advances of fabrication strategies, nanoporous metals with a variety of superior properties including unique pore structure, large specific surface area and high electrical conductivity have fuelled up great interests to explore their electrocatalytic properties and greatly extend their emerging applications in electrochemical sensing and energy systems. This tutorial review attempts to summarize the recent important progress towards the development of nanoporous metals, with special emphasis on fabrication methods and advanced electrochemical applications, such as electrocatalysts, chemical sensors and energy systems. Key scientific issues and prospective directions of research are also discussed. © 2012 The Royal Society of Chemistry.

Li C.M.,Southwest University | Li C.M.,Chongqing Key Laboratory for Advanced Materials and Technologies of Clean Energies | Li C.M.,Nanyang Technological University | Hu W.,Southwest University | Hu W.,Chongqing Key Laboratory for Advanced Materials and Technologies of Clean Energies
Journal of Electroanalytical Chemistry | Year: 2013

The tremendous advances in nanoscience and nanoengineering have sparked the accelerated development of electroanalysis towards highly sensitive and specific detections. In particular, novel nanomaterials with unique physical and chemical properties have been synthesized for electroanalysis in micro- and nano-scales to qualitatively and/or quantitatively examine the changes of compositions and structures for scientific insights and practical applications. In this review, we mainly survey our recent works on electroanalysis in micro- and nano-scales, which covers micro- and nano-fabrication techniques, microelectrodes and powder microelectrodes, direct electrochemistry of proteins, electrochemical analysis of living cells, and electrochemical immunoassay, with emphasis on the performance improvement by engineered functional nanomaterials. These electroanalytical methods have demonstrated their ability and reliability to study fundamental science and provide practical applications. It is our intention that this review could attract increasing interest to explore new electroanalytical methods in micro- and nano-scales and further develop broad important applications for critical chemical/biological sciences. © 2012 Elsevier B.V. All rights reserved.

Li C.,University of Florida | Chen T.,University of Florida | Ocsoy I.,University of Florida | Zhu G.,University of Florida | And 8 more authors.
Advanced Functional Materials | Year: 2014

The development of nanomaterials that combine diagnostic and therapeutic functions within a single nanoplatform is extremely important for molecular medicine. Molecular imaging with simultaneous diagnosis and therapy will provide the multimodality needed for accurate diagnosis and targeted therapy. Here, gold-coated iron oxide (Fe3O4@Au) nanoroses with five distinct functions are demonstrated, integrating aptamer-based targeting, magnetic resonance imaging (MRI), optical imaging, photothermal therapy. and chemotherapy into one single probe. The inner Fe3O4 core functions as an MRI agent, while the photothermal effect is achieved through near-infrared absorption by the gold shell, causing a rapid rise in temperature and also resulting in a facilitated release of the anticancer drug doxorubicin carried by the nanoroses. Where the doxorubicin is released, it is monitored by its fluorescence. Aptamers immobilized on the surfaces of the nanoroses enable efficient and selective drug delivery, imaging, and photothermal effect with high specificity. The five-function-embedded nanoroses show great advantages in multimodality. Five functions in one probe: A gold-coated iron oxide (Fe 3O4@Au) nanorose with five distinct functions, which integrate aptamer-based targeting, magnetic resonance imaging (MRI), optical imaging, photothermal and chemotherapy into one single probe is developed. This multifunctional nanoplatform is used for cancer cell targeting, dual molecular imaging, and dual therapy, with enhanced specific binding, improved cellular uptake, minimum nonspecific toxicity, and side effects. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Luo Z.,Southwest University | Luo Z.,University of Florida | Qin Y.,University of Florida | Pei Y.,Southwest University | Keyhani N.O.,University of Florida
Environmental Microbiology | Year: 2014

Summary: For most organisms, carbon and nitrogen uptake are essential for growth, development and, where applicable, pathogenesis. The role of the carbon catabolite repressor transcription factor homologue BbcreA in the entomopathogenic fungus Beauveria bassiana was investigated. Deletion of BbcreA resulted in pleiotropic effects, including nutrient toxicity, leading to a novel cell lytic phenotype. Fungal growth in rich media and minimal media containing select amino acids/peptides was severely compromised, with microscopic examination revealing conidial-base germ tube degeneration and cell lysis occurring during growth, a phenomenon exacerbated at higher temperatures (32°C). Depending upon nutrient conditions, growth, pigment and aerial mycelium production, sporulation and dimorphic transition to blastospore production were also impaired in the ΔBbcreA strain. Although loss of BbcreA resulted in de-repression of secreted protease and lipase, enzymes critical in mediating pathogenesis, insect bioassays indicated severe defects in virulence using both topical and intra-haemocoel injection assays, with eruption and subsequent sporulation on host cadavers greatly reduced in the mutant. These data suggest that BbcreA functions as more than a carbon repressor and plays important roles in nutrient utilization, cell homeostasis and virulence. In particular, BbcreA is required for proper assimilation of select amino acids and peptides, including asparagine, arginine and proline. © 2013 Society for Applied Microbiology and John Wiley & Sons Ltd.

Wu G.-R.,Southwest University | Wu G.-R.,Ghent University | Marinazzo D.,Ghent University
Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences | Year: 2016

The haemodynamic response function (HRF) is a key component of the blood oxygen level-dependent (BOLD) signal, providing the mapping between neural activity and the signal measured with functional magnetic resonance imaging (fMRI). Most of the time the HRF is associated with task-based fMRI protocols, in which its onset is explicitly included in the design matrix. On the other hand, the HRF also mediates the relationship between spontaneous neural activity and the BOLD signal in resting-state protocols, in which no explicit stimulus is taken into account. It has been shown that resting-state brain dynamics can be characterized by looking at sparse BOLD 'events', which can be retrieved by point process analysis. These events can be then used to retrieve the HRF at rest. Crucially, cardiac activity can also induce changes in the BOLD signal, thus affecting both the number of these events and the estimation of the haemodynamic response. In this study, we compare the resting-state haemodynamic response retrieved by means of a point process analysis, taking the cardiac fluctuations into account. We find that the resting-state HRF estimation is significantly modulated in the brainstem and surrounding cortical areas. From the analysis of two high-quality datasets with different temporal and spatial resolution, and through the investigation of intersubject correlation, we suggest that spontaneous point process response durations are associated with the mean interbeat interval and low-frequency power of heart rate variability in the brainstem. © 2016 The Author(s) Published by the Royal Society. All rights reserved.

Dong Y.,Nanyang Technological University | Pang H.,Nanyang Technological University | Yang H.B.,Nanyang Technological University | Guo C.,Nanyang Technological University | And 6 more authors.
Angewandte Chemie - International Edition | Year: 2013

Helpful elements: A facile bottom-up method using citric acid and L-cysteine as a precursor has been developed to prepare graphene quantum dots (GQDs) co-doped with nitrogen and sulfur. A new type and high density of surface state of GQDs arises, leading to high yields (more than 70 %) and excitation-independent emission. FLQY=fluorescence quantum yield. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Zhu G.,Hunan University | Zhu G.,University of Florida | Zhang S.,Hunan University | Song E.,University of Florida | And 7 more authors.
Angewandte Chemie - International Edition | Year: 2013

DNA nanotrain: Anchoring of preformed fluorescent DNA nanodevices (NDs; see picture) and insitu self-assembly of fluorescent DNA NDs on target living cell surfaces are reported. The insitu self-assembly of the nanodevice was further shown on surfaces of living cells in cell mixtures. These DNA NDs exhibited fluorescence emission and underwent fluorescence resonance energy transfer (FRET) on living cell surfaces. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Li Z.,Southwest University | Wang Y.,U.S. Center for Disease Control and Prevention | Kong W.,Southwest University | Li C.,Southwest University | And 2 more authors.
Biosensors and Bioelectronics | Year: 2013

Nowadays, Β2-agonists are abused illegally as "lean meat agents" for food-producing animals, and cause increasing food-safety accidents in some countries. Due to their hazard to the human health, "lean meat agents" are banned in most countries and required to be routinely monitored. We herein report a disposable electrochemiluminescent immunosensors array for near-simultaneous assay of multiple Β2-agonist residues in swine urine, by using ractopamine and salbutamol as the models. In this investigation, a screen-printed carbon electrodes array was assembled and acted as the substrate of the immunosensors array. Then the immunosensors array was constructed by site-selectively immobilizing the antigens of ractopamine and salbutamol on the working electrodes of array. After the competitive immuno-binding, with the aid of a homemade single-pore-four-throw switch, the electrochemiluminescent signals of the two Β2-agonists were sequentially detected using a non-array detector. The limits of detection for ractopamine and salbutamol were 8.5 and 17pg/mL, respectively, which were much lower than those of the most previous reports. Compared with other routine methods based on chromatography and ELISA, this method is more suitable for screening of multiple Β2-agonists in quantities of samples, owing to its merits of low cost, user-friendliness and high throughput, and shows great promise in food safety and agonist surveillance. © 2012 Elsevier B.V..

Guo C.X.,Southwest University | Guo C.X.,Chongqing Key Laboratory for Advanced Materials and Technologies of Clean Energies | Ng S.R.,Nanyang Technological University | Khoo S.Y.,Nanyang Technological University | And 5 more authors.
ACS Nano | Year: 2012

It is always challenging to construct a smart functional nanostructure with specific physicochemical properties to real time detect biointeresting molecules released from live-cells. We report here a new approach to build a free-standing biomimetic sensor by covalently bonding RGD-peptide on the surface of pyrenebutyric acid functionalized graphene film. The resulted graphene biofilm sensor comprises a well-packed layered nanostructure, in which the RGD-peptide component provides desired biomimetic properties for superior human cell attachment and growth on the film surface to allow real-time detection of nitric oxide, an important signal yet short-life molecule released from the attached human endothelial cells under drug stimulations. The film sensor exhibits good flexibility and stability by retaining its original response after 45 bending/relaxing cycles and high reproducibility from its almost unchanged current responses after 15 repeated measurements, while possessing high sensitivity, good selectivity against interferences often existing in biological systems, and demonstrating real time quantitative detection capability toward nitric oxide molecule released from living cells. This study not only demonstrates a facial approach to fabricate a smart nanostructured graphene-based functional biofilm, but also provides a powerful and reliable platform to the real-time study of biointeresting molecules released from living cells, thus rendering potential broad applications in neuroscience, screening drug therapy effect, and live-cell assays. © 2012 American Chemical Society.

Liu Y.,Nanyang Technological University | Du Y.,Nanyang Technological University | Li C.M.,Nanyang Technological University | Li C.M.,Southwest University | Li C.M.,Chongqing Key Laboratory for Advanced Materials and Technologies of Clean Energies
Electroanalysis | Year: 2013

Direct electrochemistry of redox proteins provides exciting platforms for performance improvement of biosensors and power enhancement of biofuel cells. Nanomaterials with tailored structures and unique properties are promising building blocks to promote direct electron transfer (DET) between redox-active cofactors of proteins and electrodes. This paper reviews the advances of nanostructured materials for DET of redox proteins in recent years, and is divided into applications in biosensors and biofuel cells. Both of them focus on the performance improvement, together with discussion on major challenges and opportunities for future research. The enhancement mechanism for direct electrochemistry is also reviewed for fundamental insights. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Zhang J.,Chongqing Medical University | Wei L.,Chongqing Medical University | Hu X.,Chongqing Medical University | Xie B.,Chongqing Medical University | And 4 more authors.
Parkinsonism and Related Disorders | Year: 2015

Background: Parkinson's disease (PD) is a surprisingly heterogeneous neurodegenerative disorder. It is well established that different subtypes of PD present with different clinical courses and prognoses. However, the neural mechanism underlying these disparate presentations is uncertain. Methods: Here we used resting-state fMRI (rs-fMRI) and the regional homogeneity (ReHo) method to determine neural activity patterns in the two main clinical subgroups of PD (akinetic-rigid and tremor-dominant). Results: Compared with healthy controls, akinetic-rigid (AR) subjects had increased ReHo mainly in right amygdala, left putamen, bilateral angular gyrus, bilateral medial prefrontal cortex (MPFC), and decreased ReHo in left post cingulate gyrus/precuneus (PCC/PCu) and bilateral thalamus. In contrast, tremor-dominant (TD) patients showed higher ReHo mostly in bilateral angular gyrus, left PCC, cerebellum_crus1, and cerebellum_6, while ReHo was decreased in right putamen, primary sensory cortex (S1), vermis_3, and cerebellum_4_5. These results indicate that AR and TD subgroups both represent altered spontaneous neural activity in default-mode regions and striatum, and AR subjects exhibit more changed neural activity in the mesolimbic cortex (amygdala) but TD in the cerebellar regions. Of note, direct comparison of the two subgroups revealed a distinct ReHo pattern primarily located in the striatal-thalamo-cortical (STC) and cerebello-thalamo-cortical (CTC) loops. Conclusion: Overall, our findings highlight the involvement of default mode network (DMN) and STC circuit both in AR and TD subtypes, but also underscore the importance of integrating mesolimbic-striatal and CTC loops in understanding neural systems of akinesia and rigidity, as well as resting tremor in PD. This study provides improved understanding of the pathophysiological models of different subtypes of PD. © 2014 Elsevier Ltd.

Guo S.,Southwest University | Wang C.,State University of New York at Stony Brook | Yang Y.,State University of New York at Stony Brook
IEEE Transactions on Mobile Computing | Year: 2014

The emerging wireless energy transfer technology enables charging sensor batteries in a wireless sensor network (WSN) and maintaining perpetual operation of the network. Recent breakthrough in this area has opened up a new dimension to the design of sensor network protocols. In the meanwhile, mobile data gathering has been considered as an efficient alternative to data relaying in WSNs. However, time variation of recharging rates in wireless rechargeable sensor networks imposes a great challenge in obtaining an optimal data gathering strategy. In this paper, we propose a framework of joint wireless energy replenishment and anchor-point based mobile data gathering (WerMDG) in WSNs by considering various sources of energy consumption and time-varying nature of energy replenishment. To that end, we first determine the anchor point selection strategy and the sequence to visit the anchor points. We then formulate the WerMDG problem into a network utility maximization problem which is constrained by flow, energy balance, link and battery capacity and the bounded sojourn time of the mobile collector. Furthermore, we present a distributed algorithm composed of cross-layer data control, scheduling and routing subalgorithms for each sensor node, and sojourn time allocation subalgorithm for the mobile collector at different anchor points. We also provide the convergence analysis of these subalgorithms. Finally, we implement the WerMDG algorithm in a distributed manner in the NS-2 simulator and give extensive numerical results to verify the convergence of the proposed algorithm and the impact of utility weight, link capacity and recharging rate on network performance. © 2014 IEEE.

Yang X.,Xinjiang University | Ma X.,Xinjiang University | Li Q.,Xinjiang University | Li Q.,Central South University | Guo S.,Southwest University
Journal of Alloys and Compounds | Year: 2013

Bulk magnetic Fe80-xMoxP 13C7 (x = 0, 3, 6, 9 and 12 at.%) glassy alloys were successfully prepared by the fluxing technique and J-quenching technique. The effect of Mo substitution for Fe on the glass formation ability (GFA), thermal stability, mechanical properties and magnetic properties has been studied systematically. It was found that the substitution of a small amount of Mo for Fe can dramatically enhance the GFA, which in turn, the critical maximum diameter for fully glass formation reached to 5.5 mm for x = 3 and 6.0 mm for x = 6, respectively. However, excessive substitution will promote the formation of Fe2Mo3 competition crystalline phase leading to the degradation of the GFA. Furthermore, the substitution of proper content of Mo for Fe can obviously enhance the mechanical properties of the present Fe-based alloys, which can be identified that the current FeMoPC bulk metallic glass possesses a high fracture strength (over 3000 MPa) as well as a large room temperature plasticity (above 5%). In addition, the Mo doping FePC bulk metallic glasses exhibit good soft magnetic properties with a relatively high saturation magnetization of over 1.0 T at room temperature. © 2012 Elsevier B.V. All rights reserved.

Ma X.,Xinjiang University | Yang X.,Xinjiang University | Li Q.,Xinjiang University | Guo S.,Southwest University
Journal of Alloys and Compounds | Year: 2013

Magnetic Fe80xNixP13C 7 (x = 0, 5, 10, 15, 20, 25, 30 at.%) bulk metallic glasses (BMGs) with the diameters up to 2.5 mm were prepared by the combination method of fluxing treatment and J-quenching technique. The effect of Ni substitution for Fe on the glass formation ability (GFA), thermal stability, mechanical properties and magnetic properties has been systematically investigated. It was found that the partial substitution of Ni for Fe can enhance the GFA of Fe 80P13C7 alloy, while excessive substitution will lead to the degradation of the GFA. The saturation magnetization of Fe 80xNixP13C7 (x = 0, 5, 10, 15, 20, 25, 30 at.%) BMGs gradually decrease from 1.47 T to 1.15 T with increasing Ni content from x = 0 to x = 30, and the Curie temperature firstly increases with the Ni content and then deceases when × > 20. More importantly, the quaternary monolithic Fe60Ni20P13C7 glassy alloy shows a significant plastic strain of more than 10%, which is the largest one reported to date for Fe-based BMGs. The potential beneficial effects of Ni in enhancing the GFA and the compressive plasticity of the FePC alloy system are discussed. © 2013 Elsevier B.V. All rights reserved.

Caty G.,Catholic University of Louvain | Hu L.,Southwest University | Legrain V.,Catholic University of Louvain | Legrain V.,Ghent University | And 2 more authors.
Pain | Year: 2013

The aim of this study was to assess the function of the thermo-nociceptive system in 25 patients with long-lasting, medium-to-severe refractory complex regional pain syndrome (CRPS)-1 using behavioral (detection rates and reaction times) and electrophysiological (event-related brain potentials) responses to brief (50 milliseconds) and intense (suprathreshold for Aδ-nociceptors) carbon dioxide laser stimuli delivered to the affected and contralateral limbs, and by comparing these responses to the responses obtained in the left and right limbs of age- and sex-matched healthy controls. Compared with healthy controls and compared with the contralateral limb, the detection rate of pricking pain related to the activation of Aδ-fibers was markedly reduced at the affected limb. Furthermore, reaction times were substantially prolonged (>100 milliseconds in 84% of patients and >300 milliseconds in 50% of patients). Finally, the N2 and P2 waves of laser-evoked brain potentials were significantly reduced in amplitude, and their latencies were significantly increased. Taken together, our results show that in the majority of patients with chronic CRPS-1, thermo-nociceptive pathways are dysfunctional. A number of pathological mechanisms involving the peripheral nervous system and/or the central nervous system could explain our results. However, the primary or secondary nature of these observed changes remains an open question. © 2013 International Association for the Study of Pain. Published by Elsevier B.V. All rights reserved.

Guo C.X.,Southwest University | Guo C.X.,Chongqing Key Laboratory for Advanced Materials and Technologies of Clean Energies | Wang Y.,CAS Institute of Process Engineering | Li C.M.,Southwest University | And 2 more authors.
ACS Sustainable Chemistry and Engineering | Year: 2013

A hierarchical graphene material composed of micropore (∼0.8 nm), mesopore (∼4 nm), and macropore (>50 nm) and with a specific surface area up to 1305 m2 g-1 is fabricated for physisorption hydrogen storage at atmospheric air pressure, showing a capacity over 4.0 wt %, which is significantly higher than reported graphene materials and all other kinds of carbon materials. © 2012 American Chemical Society.

Zhu G.,Hunan University | Zhu G.,University of Florida | Ye M.,Hunan University | Donovan M.J.,Hunan University | And 5 more authors.
Chemical Communications | Year: 2012

The last two decades have witnessed the development and application of nucleic acid aptamers in a variety of fields, including target analysis, disease therapy, and molecular and cellular engineering. The efficient and widely applicable aptamer selection, reproducible chemical synthesis and modification, generally impressive target binding selectivity and affinity, relatively rapid tissue penetration, low immunogenicity, and rapid systemic clearance make aptamers ideal recognition elements for use as therapeutics or for in vivo delivery of therapeutics. In this feature article, we discuss the development and biomedical application of nucleic acid aptamers, with emphasis on cancer cell aptamer isolation, targeted cancer therapy, oncology biomarker identification and drug discovery. © 2012 The Royal Society of Chemistry.

Yao J.M.,Free University of Colombia | Yao J.M.,Southwest University | Bender M.,University of Bordeaux 1 | Bender M.,French National Center for Scientific Research | Heenen P.-H.,Free University of Colombia
Physical Review C - Nuclear Physics | Year: 2013

Background: Nuclei located in the neutron-deficient Pb region have a complex structure, rapidly evolving as a function of neutron and proton numbers. The most famous example is 186Pb where the three lowest levels are 0 + states, the two excited 0+ states being located at low excitation energy around 600 keV. Coexisting structures with different properties are found in the neighboring nuclei. Many experiments have been performed over the last few years in which in-band and out-of-band γ-ray transition probabilities have been measured. Purpose: A detailed interpretation of experimental data requires the use of a method going beyond a mean-field approach that permits to determine spectra and transition probabilities. Such methods have already been applied to selected isotopes in this mass region. Our aim is to provide a systematic investigation of this mass region in order to determine how well experimental data can be understood using a state-of-the-art method for nuclear structure. Method: The starting point of our method is a set of mean-field wave functions generated with a constraint on the axial quadrupole moment and using a Skyrme energy density functional. Correlations beyond the mean field are introduced by projecting mean-field wave functions on angular-momentum and particle number and by mixing the symmetry-restored wave functions as a function of the axial quadrupole moment. Results: A detailed comparison with the available data is performed for energies, charge radii, spectroscopic quadrupole moments, and E0 and E2 transition probabilities for the isotopic chains of neutron deficient Hg, Pb, Po, and Rn. The connection between our results and the underlying mean field is also analyzed. Conclusions: Qualitative agreement with the data is obtained although our results indicate that the actual energy density functionals have to be improved further to achieve a quantitative agreement. © 2013 American Physical Society.

Lei X.,Southwest University | Wang Y.,Southwest University | Yuan H.,Southwest University | Mantini D.,University of Oxford | Mantini D.,ETH Zurich
Human Brain Mapping | Year: 2014

Functional magnetic imaging (fMRI) studies showed that resting state activity in the healthy brain is organized into multiple large-scale networks encompassing distant regions. A key finding of resting state fMRI studies is the anti-correlation typically observed between the dorsal attention network (DAN) and the default mode network (DMN), which-during task performance-are activated and deactivated, respectively. Previous studies have suggested that alcohol administration modulates the balance of activation/deactivation in brain networks, as well as it induces significant changes in oscillatory activity measured by electroencephalography (EEG). However, our knowledge of alcohol-induced changes in band-limited EEG power and their potential link with the functional interactions between DAN and DMN is still very limited. Here we address this issue, examining the neuronal effects of alcohol administration during resting state by using simultaneous EEG-fMRI. Our findings show increased EEG power in the theta frequency band (4-8 Hz) after administration of alcohol compared to placebo, which was prominent over the frontal cortex. More interestingly, increased frontal tonic EEG activity in this band was associated with greater anti-correlation between the DAN and the frontal component of the DMN. Furthermore, EEG theta power and DAN-DMN anti-correlation were relatively greater in subjects who reported a feeling of euphoria after alcohol administration, which may result from a diminished inhibition exerted by the prefrontal cortex. Overall, our findings suggest that slow brain rhythms are responsible for dynamic functional interactions between brain networks. They also confirm the applicability and potential usefulness of EEG-fMRI for central nervous system drug research. Hum Brain Mapp 35:3517-3528, 2014. © 2013 Wiley Periodicals, Inc.

Weng Z.,University of Lausanne | Peng Z.,Southwest University | Nadarajah S.,University of Manchester
Extremes | Year: 2012

We derive the joint limiting distribution and the almost sure limit theorem for the maxima and minima for a strongly dependent stationary Gaussian vector sequence. © 2011 Springer Science+Business Media, LLC.

Ling C.,University of Lausanne | Peng Z.,Southwest University | Nadarajah S.,University of Manchester
Extremes | Year: 2012

In this paper, a new kind of location invariant Weiss-Hill estimator of the extreme value index γ ∈ ℝ is proposed. The new estimator is a combination of two estimators proposed by Weiss (Nav Res Logist Q 1:111-114, 1971) and Fraga Alves (Extremes 4:199-217, 2001a). The following properties of the new estimator are derived: weak consistency, strong consistency, and asymptotic expansions. A bias corrected version of the proposed estimator is given after determining an optimal sample fraction. Some finite simulation studies are performed. © 2011 Springer Science+Business Media, LLC.

Pu W.D.,Southwest University | Zhang L.,Southwest University | Zhang L.,Nanchang University | Huang C.Z.,Southwest University
Analytical Methods | Year: 2012

Because of its rich π electrons, graphene oxide (GO) can bind with single-stranded DNA (ssDNA) through π-π stacking, but it cannot bind with double-stranded DNA (dsDNA). This different binding ability of GO with DNA has found many applications. By combining this ability with aptamer chemistry, we have developed a highly selective method for the detection of adenosine triphosphate (ATP). The hybrid of ATP aptamer with fluorescein (FAM)-labelled complementary DNA (FAM-DNA) demonstrates a weak affinity for GO and strong fluorescence of FAM-DNA. If ATP is present the strong fluorescence of FAM-DNA is quenched, because the binding of ATP with its aptamer greatly inhibits hybridization of the aptamer with FAM-DNA, and the unhybridized FAM-DNA is adsorbed on to the surface of GO. The quenched fluorescence intensity was found to be in proportion to the concentration of ATP in the range 3-320 μM with a detection limit of 0.45 μM. This method of ATP detection is highly selective and the existence of GTP, CTP and UTP have scarcely effect the determination. © 2012 The Royal Society of Chemistry.

Ma M.,Southwest University | Chakraborty M.K.,Jadavpur University
International Journal of Approximate Reasoning | Year: 2016

Two conjectures on the covering-based rough set semantics for modal logics in [35] are answered. The C2 and C5 semantics give rise to the same modal system S4. There are Galois connections between C2 and C5 which lead to the covering-based semantics for the temporal logic system S4t. The P1 and C4 semantics give rise to the same modal system KTB. © 2016 Published by Elsevier Inc.

Gao C.,Hong Kong Baptist University | Gao C.,Southwest University | Liu J.,Hong Kong Baptist University
IEEE Transactions on Mobile Computing | Year: 2013

Viruses and malwares can spread from computer networks into mobile networks with the rapid growth of smart cellphone users. In a mobile network, viruses and malwares can cause privacy data leakage, extra charges, and remote listening. Furthermore, they can jam wireless servers by sending thousands of spam messages or track user positions through GPS. Because of the potential damages of mobile viruses, it is important for us to gain a deep understanding of the propagation mechanisms of mobile viruses. In this paper, we propose a two-layer network model for simulating virus propagation through both Bluetooth and SMS. Different from previous work, our work addresses the impacts of human behaviors, i.e., operational behavior and mobile behavior, on virus propagation. Our simulation results provide further insights into the determining factors of virus propagation in mobile networks. Moreover, we examine two strategies for restraining mobile virus propagation, i.e., preimmunization and adaptive dissemination strategies drawing on the methodology of autonomy-oriented computing (AOC). The experimental results show that our strategies can effectively protect large-scale and/or highly dynamic mobile networks. © 2002-2012 IEEE.

Yao J.-M.,Free University of Colombia | Yao J.-M.,Southwest University | Baroni S.,Free University of Colombia | Bender M.,University of Bordeaux 1 | And 2 more authors.
Physical Review C - Nuclear Physics | Year: 2012

Recent self-consistent mean-field calculations predict a substantial depletion of the proton density in the interior of 34Si. In the present study, we investigate how correlations beyond the mean field modify this finding. The framework of the calculation is a particle-number and angular-momentum projected generator coordinate method based on Hartree-Fock-Bogoliubov+Lipkin-Nogami states with axial quadrupole deformation. The parametrization SLy4 of the Skyrme energy density functional is used together with a density-dependent pairing energy functional. For the first time, the generator coordinate method is applied to the calculation of charge densities. The impact of pairing correlations, symmetry restorations and shape mixing on the density profile is analyzed step by step. All these effects significantly alter the radial density profile, and tend to bring it closer to a Fermi-type density distribution. © 2012 American Physical Society.

Gao C.,Southwest University | Liu J.,Hong Kong Baptist University
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2012

An extreme event such as a natural disaster may cause social and economic damages. Human beings, whether individuals or society as a whole, often respond to the event with emotional reactions (e.g., sadness, anxiety and anger) as the event unfolds. These reactions are, to some extent, reflected in the contents of news articles and published reports. Thus, a systematic method for analyzing these contents would help us better understand human emotional reactions at a certain stage (or an episode) of the event, find out their underlying reasons, and most importantly, remedy the situations by way of planning and implementing effective relief responses (e.g., providing specific information concerning certain aspects of an event). This paper presents a clustering-based method for analyzing human emotional reactions during an event and detecting their corresponding episodes based on the co-occurrences of the words as used in the articles. We demonstrate this method by showing a case study on Japanese earthquake in 2011, revealing several distinct patterns with respect to the event episodes. © 2012 Springer-Verlag.

Tang X.,Southwest University | Shao F.,Chongqing Educational Science Academy
Journal of Science Education and Technology | Year: 2014

Group preparation for teaching contest, or lesson polishing, is a teacher professional development activity unique to China. Through participant observation and discourse analysis of a typical case, this study explores how a science lesson evolved through lesson-polishing process and how such process influenced individual learning and the development of local teaching community. Our work illustrates both the values and the issues of lesson polishing as a type of teacher professional development activity. On one hand, combining professional interactions and trial lessons, lesson-polishing activity opens up space for critical yet cooperative professional interactions and tryouts of different designs and teaching strategies, providing opportunities for individual learning and development of practical rationalities within local community. On the other hand, the functions of such activities are greatly limited by the tendency of refining every detail in lesson design, the existence of overriding dispositions and authorities with overriding power, as well as the focus on practical suggestions that can be directly implemented. Suggestions for improvement are made in the final discussion. © 2013 Springer Science+Business Media New York.

Dai X.,Southwest University | Gao Z.,Northumbria University | Breikin T.,Sheffield Hallam University | Wang H.,University of Manchester
IEEE Transactions on Automatic Control | Year: 2012

This technical note analyzes the estimation delay in a high gain observer, where the state estimates may lag behind the actual states due to the observer's non-zero phase response. The technical note proves that, for a slowly time-varying system subject to bounded noises, the estimation delay depends on the observer gain, but is independent of the variations of system parameters. Rather than estimating the delay, a novel method is proposed to calculate the delay from the observer's phase response. In terms of system identification, the delay is compensated by aligning other measurements with the lagged estimate so that they have the same lag. The simulation results of an aero engine model show significant improvements in estimation. On one hand, the proposed approach improves the estimation accuracy, and on the other hand, it removes the assumption of zero delay and gives a new insight into the high-gain observer design. © 2011 IEEE.

Nanoparticles designed to block a cell-surface molecule that plays a key role in inflammation could be a safe treatment for inflammatory bowel disease (IBD), according to researchers in the Institute for Biomedical Sciences at Georgia State University and Southwest University in China.

News Article | November 21, 2016

Called a "replicon system," the new tool is the work of researchers from the University of Texas Medical Branch (UTMB) in Galveston, Southwest University in Chongqing, China, and the University of Leuven in Belgium. They describe how they developed and tested the system in the journal EBioMedicine. Zika virus is a mosquito-borne member of the genus flavivirus, which includes dengue fever, yellow fever, West Nile virus, and other viruses that cause significant human diseases. Many people infected with Zika do not have symptoms or only experience mild symptoms, including fever, rash, joint pain, muscle pain, red eyes (conjunctivitis), and headache. Zika infections are rarely serious enough to require hospitalization, and people very rarely die of it. Once a person has been infected, they are less likely to become infected again. However, Zika is risky for some people. Infection during pregnancy can cause severe fetal brain defects, such as microcephaly, and other problems that affect the eyes, hearing, and growth. There have also been reports that areas affected by Zika have higher rates of Guillain-Barré syndrome, a rare and serious disorder of the nervous system. The current epidemic of Zika virus disease in the Americas poses a global public health emergency. Yet despite urgent medical needs, there are no medicines or vaccines against the virus. Disease viruses spread by infecting host cells and taking over their machinery to make copies of themselves that go on to infect more cells. Replicons are portions of the viral genome that can replicate on their own, without relying on the machinery of the host cell. They are used in research and drug development for studying certain features of viruses, such as their replication machinery. The authors of the new study note that replicon systems have been widely used for other flaviviruses, such as dengue fever and West Nile virus. For their study, the researchers created an experimental system that generates replicons of the Zika virus that are stripped of the genes that give the virus its structure and make it infectious. This makes it less dangerous to work with. Senior author Pei-Yong Shi, a professor in the department of biochemistry and molecular biology at UTMB, explains: "One of these replicons can be used to locate portions of the viral molecule that block or halt viral replication, making it a powerful tool for vaccine development." "The other newly developed replicon was designed to study potential antiviral agents by differentiating between when the virus is making copies of itself and when it's altering its structure," Prof. Shi adds. An important feature of the system is it attaches genes to the replicons so the researchers can tag the parts of the virus they are interested in. For example, they are able to use Luciferase, the compound that makes fireflies glow, to light up targeted parts of the virus so they can more easily observe particular processes, such as replication.

Edible ginger-derived nano-lipids created from a specific population of ginger nanoparticles show promise for effectively targeting and delivering chemotherapeutic drugs used to treat colon cancer, according to a study by researchers at the Institute for Biomedical Sciences at Georgia State University, the Atlanta Veterans Affairs Medical Center and Wenzhou Medical University and Southwest University in China.

Chen B.,Southwest University | Li H.,Southwest University | Ding Y.,Southwest University | Rao J.,University of Massachusetts Amherst
Food Research International | Year: 2011

The potential of beet pectin for improving the physical and chemical stabilities of emulsions containing silk fibroin coated droplets was investigated. Five wt.% corn oil-in-water emulsions containing fibroin-coated droplets (0.5. wt.% fibroin) and anionic pectin (0.05 wt.%) were prepared at pH 7. The pH of these emulsions was then adjusted to pH 4, so that the anionic pectin molecules electrostatically deposited to the fibroin-coated droplets. The influence of pH (3 to 7) and sodium chloride concentrations (0 to 500 mM) on the properties of primary (0 wt.% pectin) and secondary (0.05 wt.% pectin) emulsions was studied. Pectin was deposited to the droplet surfaces at pH 3, 4, and 5, but not at pH 6 and 7. In addition, secondary emulsions were stable up to higher ionic strengths (<. 500 mM) than primary emulsions (<. 200 mM). The addition of beet pectin also prolonged the lag phase of lipid oxidation in the emulsions as determined by the formation of lipid hydroperoxides and headspace hexanal. The controlled electrostatic deposition method utilized in this study could be used to extend the range of application of silk fibroin in the industry. © 2011 Elsevier Ltd.

Zhang J.,Nanyang Technological University | Peng Z.,Southwest University | Soni A.,Nanyang Technological University | Zhao Y.,Nanyang Technological University | And 5 more authors.
Nano Letters | Year: 2011

We report on Raman spectroscopy of few quintuple layer topological insulator bismuth selenide (Bi2Se3) nanoplatelets (NPs), synthesized by a polyol method. The as-grown NPs exhibit excellent crystalline quality, hexagonal or truncated trigonal morphology, and uniformly flat surfaces down to a few quintuple layers. Both Stokes and anti-Stokes Raman spectroscopy for the first time resolve all four optical phonon modes from individual NPs down to 4 nm, where the out-of-plane vibrational A1g1 mode shows a few wavenumbers red shift as the thickness decreases below ∼15 nm. This thickness-dependent red shift is tentatively explained by a phonon softening due to the decreasing of the effective restoring force arising from a decrease of the van der Waals forces between adjacent layers. Quantitatively, we found that the 2D phonon confinement model proposed by Faucet and Campbell cannot explain the red shift values and the line shape of the A1g1 mode, which can be described better by a Breit - Wigner - Fano resonance line shape. Considerable broadening (∼17 cm-1 for six quintuple layers) especially for the in-plane vibrational mode Eg2 is identified, suggesting that the layer-to-layer stacking affects the intralayer bonding. Therefore, a significant reduction in the phonon lifetime of the in-plane vibrational modes is probably due to an enhanced electron - phonon coupling in the few quintuple layer regime. © 2011 American Chemical Society.

Guo S.F.,Southwest University | Zhang H.J.,Chongqing University | Liu Z.,Hong Kong Polytechnic University | Chen W.,Hong Kong Polytechnic University | Xie S.F.,Jiangxi Academy of science
Electrochemistry Communications | Year: 2012

It is well recognized that amorphous alloys usually offer much higher resistance to corrosion over their conventional counterparts in most aqueous solutions. Whereas, in this work, we reported an anomalous corrosion resistance of an arc melting Zr 62.3Cu 22.5Fe 4.9Al 6.8Ag 3.5 crystalline alloy, which was superior to that of the same composition in glassy state in simulated seawater. It was revealed that the easy formation of a highly protective Zr- and Al-enriched oxide layer at the surface of the crystalline alloy is responsible for the extremely high corrosion resistance. The current finding not only presents an excellent alloy candidate for potential application in seawater but provides a new insight into the understanding of corrosion behavior of amorphous/crystalline alloys in demanding corrosive media. © 2012 Elsevier B.V.

Wang J.,Southwest University | Wang J.,Xi'an Jiaotong University | Xu Z.,Xi'an Jiaotong University
Neural Networks | Year: 2010

For the nearly exponential type of feedforward neural networks (neFNNs), the essential order of their approximation is revealed. It is proven that for any continuous function defined on a compact set of Rd, there exist three layers of neFNNs with the fixed number of hidden neurons that attain the essential order. Under certain assumption on the neFNNs, the ideal upper bound and lower bound estimations on approximation precision of the neFNNs are provided. The obtained results not only characterize the intrinsic property of approximation of the neFNNs, but also proclaim the implicit relationship between the precision (speed) and the number of hidden neurons of the neFNNs. © 2010 Elsevier Ltd.

Fu A.,University of Massachusetts Amherst | Fu A.,Southwest University | Tang R.,University of Massachusetts Amherst | Hardie J.,University of Massachusetts Amherst | And 2 more authors.
Bioconjugate Chemistry | Year: 2014

The direct delivery of functional proteins into the cell cytosol is a key issue for protein therapy, with many current strategies resulting in endosomal entrapment. Protein delivery to the cytosol is challenging due to the high molecular weight and the polarity of therapeutic proteins. Here we review strategies for the delivery of proteins into cells, including cell-penetrating peptides, virus-like particles, supercharged proteins, nanocarriers, polymers, and nanoparticle-stabilized nanocapsules. The advantages and disadvantages of these approaches including cytosolar delivery are compared and contrasted, with promising pathways forward identified. (Figure Presented). © 2014 American Chemical Society.

Zhu L.,Southwest University | Yang H.B.,Nanyang Technological University | Zhong C.,Hubei University | Li C.M.,Southwest University
Dyes and Pigments | Year: 2014

Two new sensitizers based on triphenylamine-dicyanovinylene have been synthesized and used for p-type dye-sensitized solar cells. The best performance amongst solar cells was achieved by the dye with a ter-thiophene bridge ligand between carboxylic acid group and the triphenylamine part (with power conversion efficiency of 0.19%, short circuit current of 4.01 mA cm-2, open circuit voltage at 144 mV, and fill factor of 0.33). Results indicate that the ter-thiophene groups in the dyes strongly affects both charge recombination and hole injection in the photoelectrode. In addition, the hexyl chains on the bridged thiophene rings also help to avoid dye aggregation on the nickel oxide film and block I- in electrolyte from approaching the surface of nickel oxide, which leads to a reduction in the charge recombination between nickel oxide semiconductor and electrolyte. This study suggested that modification of the bridge moiety between triphenylamine and the carboxylic group by increasing thiophene units is a promising way for preventing charge recombination and increasing the power conversion efficiency. © 2014 Elsevier Ltd. All rights reserved.

Zhang L.Y.,Southwest University | Zhang L.Y.,Chongqing Key Laboratory for Advanced Materials | Zhao Z.L.,Southwest University | Zhao Z.L.,Chongqing Key Laboratory for Advanced Materials | And 2 more authors.
Nano Energy | Year: 2015

For the first time, herein formic acid is used to reduce precursor for uniformly distributed ultrasmall Pd nanocrystals on graphene as an electrocatalyst towards formic acid oxidation, demonstrating more negative half-wave potential, much higher catalytic current density, lower charge-transfer resistance and better stability than that of the commercial Pd/C catalyst. Except the contribution of the ultrasmall Pd nanocrystals and graphene to the better catalytic performance than the commercial one, we argue that it could be also attributed to the Pd nanoparticles formed by reduction of formic acid to naturally possess strong affinity for strong absorption towards its oxidation for fast electrooxidation process. © 2014 Elsevier Ltd.

Wang Y.,Xi'an Jiaotong University | Wang J.,Southwest University | Xu Z.,Xi'an Jiaotong University
Signal Processing | Year: 2014

In this paper, by generalizing the notion of restricted p-isometry constant (0<-rfpag≤1) defined by Chartrand and Staneva [1] to the setting of block-sparse signal recovery, we establish a general restricted p-isometry property (p-RIP) condition for recovery of (nearly) block-sparse signals via mixed l;bsubesubbsube-minimization. Moreover, we derive a lower bound on the necessary number of Gaussian measurements for the p-RIP condition to hold with high probability, which shows clearly that fewer measurements with smaller p are needed for exact recovery of block-sparse signals via mixed l;bsubesubbsube-minimization than when p=1. © 2014 Elsevier B.V.

Song E.-Q.,Wuhan University | Song E.-Q.,Southwest University | Hu J.,Wuhan University | Wen C.-Y.,Wuhan University | And 5 more authors.
ACS Nano | Year: 2011

Fluorescent-magnetic-biotargeting multifunctional nanobioprobes (FMBMNs) have attracted great attention in recent years due to their increasing, important applications in biomedical research, clinical diagnosis, and biomedicine. We have previously developed such nanobioprobes for the detection and isolation of a single kind of tumor cells. Detection and isolation of multiple tumor markers or tumor cells from complex samples sensitively and with high efficiency is critical for the early diagnosis of tumors, especially malignant tumors or cancers, which will improve clinical diagnosis outcomes and help to select effective treatment approaches. Here, we expanded the application of the monoclonal antibody (mAb)-coupled FMBMNs for multiplexed assays. Multiple types of cancer cells, such as leukemia cells and prostate cancer cells, were detected and collected from mixed samples within 25 min by using a magnet and an ordinary fluorescence microscope. The capture efficiencies of mAb-coupled FMBMNs for the above-mentioned two types of cells were 96% and 97%, respectively. Furthermore, by using the mAb-coupled FMBMNs, specific and sensitive detection and rapid separation of a small number of spiked leukemia cells and prostate cancer cells in a large population of cultured normal cells (about 0.01% were tumor cells) were achieved simply and inexpensively without any sample pretreatment before cell analysis. Therefore, mAb-coupled multicolor FMBMNs may be used for very sensitive detection and rapid isolation of multiple cancer cells in biomedical research and medical diagnostics. © 2011 American Chemical Society.

Wang Y.,Xi'an Jiaotong University | Wang J.,Southwest University | Xu Z.,Xi'an Jiaotong University
Eurasip Journal on Advances in Signal Processing | Year: 2013

Compressed sensing (CS) states that a sparse signal can exactly be recovered from very few linear measurements. While in many applications, real-world signals also exhibit additional structures aside from standard sparsity. The typical example is the so-called block-sparse signals whose non-zero coefficients occur in a few blocks. In this article, we investigate the mixed l 2/l q (0 < q ≤ 1) norm minimization method for the exact and robust recovery of such block-sparse signals. We mainly show that the non-convex l 2/l q (0 < q < 1) minimization method has stronger sparsity promoting ability than the commonly used l 2/l 1 minimization method both practically and theoretically. In terms of a block variant of the restricted isometry property of measurement matrix, we present weaker sufficient conditions for exact and robust block-sparse signal recovery than those known for l 2/l 1 minimization. We also propose an efficient Iteratively Reweighted Least-Squares (IRLS) algorithm for the induced non-convex optimization problem. The obtained weaker conditions and the proposed IRLS algorithm are tested and compared with the mixed l 2/l 1 minimization method and the standard l q minimization method on a series of noiseless and noisy block-sparse signals. All the comparisons demonstrate the outperformance of the mixed l 2/l q (0 < q < 1) method for block-sparse signal recovery applications, and meaningfulness in the development of new CS technology. © 2013 Wang et al.; licensee Springer.

Hu W.,Southwest University | Hu W.,Wuhan University | Chen H.,Southwest University | Shi Z.,Southwest University | Yu L.,Southwest University
Analytical Biochemistry | Year: 2014

Surface plasmon resonance imaging (SPRi) is an intriguing technique for immunoassay with the inherent advantages of being high throughput, real time, and label free, but its sensitivity needs essential improvement for practical applications. Here, we report a dual signal amplification strategy using functional gold nanoparticles (AuNPs) followed by on-chip atom transfer radical polymerization (ATRP) for sensitive SPRi immunoassay of tumor biomarker in human serum. The AuNPs are grafted with an initiator of ATRP as well as a recognition antibody, where the antibody directs the specific binding of functional AuNPs onto the SPRi sensing surface to form immunocomplexes for first signal amplification and the initiator allows for on-chip ATRP of 2-hydroxyethyl methacrylate (HEMA) from the AuNPs to further enhance the SPRi signal. High sensitivity and broad dynamic range are achieved with this dual signal amplification strategy for detection of a model tumor marker, α-fetoprotein (AFP), in 10% human serum. © 2014 Elsevier Inc. All rights reserved.

Wu C.,Southwest University | Wu C.,Chongqing Unis Chemical Co. | Long X.,Chongqing Unis Chemical Co. | Li S.,Southwest University | Fu X.,Southwest University
Tetrahedron Asymmetry | Year: 2012

Nine O-acylated threonines were screened as catalysts at loadings of 0.5-5 mol % for the direct asymmetric stoichiometric aldol reaction on water by using variable amounts of water. These threonine-based organocatalyst were simple, inexpensive, highly active and could be synthesized on a large-scale. Among them, the threonine-based organocatalyst 1a is applicable to the stoichiometric reactions of a wide range of aromatic and heteroaromatic aldehydes with ketones, with the aldol products being obtained with up to 99:1 anti/syn ratios and >99% ee. The threonine-based organocatalyst 1a can be easily recovered and reused, and only a slight decrease in the enantioselectivities was observed after six cycles. This novel threonine-based organocatalyst 1a can be efficiently used in large-scale reactions with the enantioselectivities being maintained at the same level, which offers great possibility for application in industry. © 2012 Elsevier Ltd. All rights reserved.

Shang Y.,Southwest University | Xiong Y.L.,University of Kentucky
Journal of Food Science | Year: 2010

In this study, the effect of xanthan on dynamic rheological properties, textural profile, and water binding of transglutaminase (TG)-treated myofibrillar protein (MP) gels was investigated. In experiment 1, MP suspensions (40 mg/mL protein, 0.6 M NaCl) at pH 6.45 with or without 0.05% xanthan were treated with 0%, 0.1%, 0.2%, 0.3%, 0.4%, and 0.5% TG; in experiment 2, MP suspensions (40 mg/mL protein, 0.6 M NaCl) at pHs 6.13, 6.30, 6.45, 6.69 with or without 0.05% xanthan were treated with 0.3% TG. Treated samples were analyzed with differential scanning calorimetry for thermal stability and oscillatory rheometry and Instron penetration tests for gelation properties. The TG treatments lowered the transition temperature (Tm) of MP by as much as 6 °C (P < 0.05) but increased apparent enthalpy of denaturation. However, there was no detectable thermal stability difference between MP samples with or without xanthan. The shear storage modulus (G′) of MP gels increased markedly upon treatments with ≥0.3% TG, and the presence of xanthan further enhanced the gel strength (P < 0.05). The addition of 0.05% xanthan decreased cooking loss of TG-treated MP gels by 17% to 23% when compared with gels without xanthan at all pH levels evaluated (6.13 to 6.67). Thus, the combination of TG and xanthan offered a feasible means to promote cross-linking and gelation of MP while reducing cooking losses. © 2010 Institute of Food Technologists®.

Diogo R.,Howard University | Peng Z.,Southwest University | Wood B.,George Washington University
Journal of Anatomy | Year: 2013

Here we provide the first report about the rates of muscle evolution derived from Bayesian and parsimony cladistic analyses of primate higher-level phylogeny, and compare these rates with published rates of molecular evolution. It is commonly accepted that there is a 'general molecular slow-down of hominoids', but interestingly the rates of muscle evolution in the nodes leading and within the hominoid clade are higher than those in the vast majority of other primate clades. The rate of muscle evolution at the node leading to Homo (1.77) is higher than that at the nodes leading to Pan (0.89) and particularly to Gorilla (0.28). Notably, the rates of muscle evolution at the major euarchontan and primate nodes are different, but within each major primate clade (Strepsirrhini, Platyrrhini, Cercopithecidae and Hominoidea) the rates at the various nodes, and particularly at the nodes leading to the higher groups (i.e. including more than one genera), are strikingly similar. We explore the implications of these new data for the tempo and mode of primate and human evolution. © 2013 Anatomical Society.

Hu L.,Southwest University | Peng W.,University of Hong Kong | Valentini E.,University of Rome La Sapienza | Valentini E.,Hospitalization and Health Care | And 2 more authors.
Journal of Pain | Year: 2013

Nociceptive stimuli can induce a transient suppression of electroencephalographic oscillations in the alpha frequency band (ie, alpha event-related desynchronization, α-ERD). Here we investigated whether α-ERD could be functionally distinguished in 2 temporally and spatially segregated subcomponents as suggested by previous studies. In addition, we tested whether the degree of dependence of nociceptive-induced α-ERD magnitude on the prestimulus α-power would have been larger than the degree of dependence on the poststimulus α-power. Our findings confirmed the dissociation between a sensory-related α-ERD maximally distributed over contralateral central electrodes, and a task-related α-ERD (possibly affected by motor-related activity), maximally distributed at posterior parietal and occipital electrodes. The cortical sources of these activities were estimated to be located at the level of sensorimotor and bilateral occipital cortices, respectively. Importantly, the time course of the α-ERD revealed that functional segregation emerged only at late latencies (400 to 750 ms) whereas topographic similarity was observed at earlier latencies (250 to 350 ms). Furthermore, the nociceptive-induced α-ERD magnitude was significantly more dependent on prestimulus than poststimulus α-power. Altogether these findings provide direct evidence that the nociceptive-induced α-ERD reflects the summation of sensory-related and task-related cortical processes, and that prestimulus fluctuations can remarkably influence the non-phase-locked nociceptive α-ERD. Perspective: Present results extend the functional understanding of α-oscillation suppression during pain perception and demonstrate the influence of prestimulus variability on this cortical phenomenon. This work has the potential to guide pain clinicians in a more accurate interpretation on physiological and psychological modulations of α-oscillations. © 2013 by the American Pain Society.

Jiang B.,Chongqing University of Technology | Wang M.,Chongqing University of Technology | Chen Y.,Southwest University | Xie J.,Chongqing University of Technology | Xiang Y.,Southwest University
Biosensors and Bioelectronics | Year: 2012

We demonstrated a new strategy for highly sensitive electrochemical detection of cocaine by using two engineered aptamers in connection to redox-recycling signal amplification. The graphene/AuNP nanocomposites were electrochemically deposited on a screen printed carbon electrode to enhance the electron transfers. The cocaine primary binding aptamers were self-assembled on the electrode surface through sulfur-Au interactions. The presence of the target cocaine and the biotin-modified secondary binding aptamers leads to the formation of sandwich complexes on the electrode surface. The streptavidin-conjugated alkaline phosphatases (ALPs) were used as labels to generate quantitative signals. The addition of the ALP substrate and the co-reactant NADH results in the formation of a redox cycle between the enzymatic product and the electrochemically oxidized species and the signal is thus significantly amplified. Because of the effective modification of the sensing surface and signal amplification, low nanomolar (1. nM) detection limit for cocaine is achieved. The proposed aptamer-based sandwich sensing approach for amplified detection of cocaine thus opens new opportunities for highly sensitive determination of other small molecules. © 2011 Elsevier B.V.

Hu L.,Southwest University | Valentini E.,University of Rome La Sapienza | Valentini E.,Hospitalization and Health Care | Zhang Z.G.,University of Hong Kong | And 2 more authors.
NeuroImage | Year: 2014

Nociceptive laser pulses elicit temporally-distinct cortical responses (the N1, N2 and P2 waves of laser-evoked potentials, LEPs) mainly reflecting the activity of the primary somatosensory cortex (S1) contralateral to the stimulated side, and of the bilateral operculoinsular and cingulate cortices. Here, by performing two different EEG experiments and applying a range of analysis approaches (microstate analysis, scalp topography, single-trial estimation), we describe a distinct component in the last part of the human LEP response (P4 wave). We obtained three main results. First, the LEP is reliably decomposed in four main and distinct functional microstates, corresponding to the N1, N2, P2, and P4 waves, regardless of stimulus territory. Second, the scalp and source configurations of the P4 wave follow a clear somatotopical organization, indicating that this response is likely to be partly generated in contralateral S1. Third, single-trial latencies and amplitudes of the P4 are tightly coupled with those of the N1, and are similarly sensitive to experimental manipulations (e.g., to crossing the hands over the body midline), suggesting that the P4 and N1 may have common neural sources. These results indicate that the P4 wave is a clear and distinct LEP component, which should be considered in LEP studies to achieve a comprehensive understanding of the brain response to nociceptive stimulation. © 2013.

Song Y.,Southwest University | Song Y.,University of Iowa | Buettner G.R.,University of Iowa
Free Radical Biology and Medicine | Year: 2010

The quinone/semiquinone/hydroquinone triad (Q/SQ.-/H2Q) represents a class of compounds that has great importance in a wide range of biological processes. The half-cell reduction potentials of these redox couples in aqueous solutions at neutral pH, E°', provide a window to understanding the thermodynamic and kinetic characteristics of this triad and their associated chemistry and biochemistry in vivo. Substituents on the quinone ring can significantly influence the electron density "on the ring" and thus modify E°' dramatically. E°' of the quinone governs the reaction of semiquinone with dioxygen to form superoxide. At near-neutral pH the pKa's of the hydroquinone are outstanding indicators of the electron density in the aromatic ring of the members of these triads (electrophilicity) and thus are excellent tools to predict half-cell reduction potentials for both the one-electron and two-electron couples, which in turn allow estimates of rate constants for the reactions of these triads. For example, the higher the pKa's of H2Q, the lower the reduction potentials and the higher the rate constants for the reaction of SQ.- with dioxygen to form superoxide. However, hydroquinone autoxidation is controlled by the concentration of di-ionized hydroquinone; thus, the lower the pKa's the less stable H2Q to autoxidation. Catalysts, e.g., metals and quinone, can accelerate oxidation processes; by removing superoxide and increasing the rate of formation of quinone, superoxide dismutase can accelerate oxidation of hydroquinones and thereby increase the flux of hydrogen peroxide. The principal reactions of quinones are with nucleophiles via Michael addition, for example, with thiols and amines. The rate constants for these addition reactions are also related to E°'. Thus, pKa's of a hydroquinone and E°' are central to the chemistry of these triads. © 2010 Elsevier Inc.

Chen Y.,Southwest University | Jiang B.,Chongqing University of Technology | Xiang Y.,Southwest University | Chai Y.,Southwest University | Yuan R.,Southwest University
Chemical Communications | Year: 2011

The preparation and use of a new class of signal amplification label, the CdTe quantum dot layer-by-layer assembled polystyrene microbead composite, for amplified ultrasensitive electrochemiluminescent detection of thrombin is described. © 2011 The Royal Society of Chemistry.

Zhang H.,Southwest University | Jiang B.,Chongqing University of Technology | Xiang Y.,Southwest University | Chai Y.,Southwest University | Yuan R.,Southwest University
Analyst | Year: 2012

In this work, by incorporating a specific DNAzyme sequence into a hairpin aptamer probe, we describe a label-free and sensitive method for electrochemical detection of cytokines using recombinant human IFN-γ as the model analyte. The hairpin aptamer probes are immobilized on a gold electrode through self-assembly. The presence of IFN-γ opens the hairpin structure and forms the hemin/G-quadruplex peroxidase-mimicking DNAzyme with subsequent addition of hemin. The peroxidase-mimicking DNAzyme catalyzes the electro-reduction of H 2O 2 and amplifies the current response for IFN-γ detection, which enables the monitoring of IFN-γ at the sub-nanomolar level. The proposed sensor also shows high selectivity towards the target analyte. Our strategy thus opens new opportunities for label-free and amplified detection of different types of cytokines. © The Royal Society of Chemistry 2012.

Zhang L.,Southwest University | Peng W.,University of Hong Kong | Zhang Z.,University of Hong Kong | Hu L.,Southwest University
PLoS ONE | Year: 2013

Transient event-related potentials (ERPs) and steady-state responses (SSRs) have been popularly employed to investigate the function of the human brain, but their relationship still remains a matter of debate. Some researchers believed that SSRs could be explained by the linear summation of successive transient ERPs (superposition hypothesis), while others believed that SSRs were the result of the entrainment of a neural rhythm driven by the periodic repetition of a sensory stimulus (oscillatory entrainment hypothesis). In the present study, taking auditory modality as an example, we aimed to clarify the distinct features of SSRs, evoked by the 40-Hz and 60-Hz periodic auditory stimulation, as compared to transient ERPs, evoked by a single click. We observed that (1) SSRs were mainly generated by phase synchronization, while late latency responses (LLRs) in transient ERPs were mainly generated by power enhancement; (2) scalp topographies of LLRs in transient ERPs were markedly different from those of SSRs; (3) the powers of both 40-Hz and 60-Hz SSRs were significantly correlated, while they were not significantly correlated with the N1 power in transient ERPs; (4) whereas SSRs were dominantly modulated by stimulus intensity, middle latency responses (MLRs) were not significantly modulated by both stimulus intensity and subjective loudness judgment, and LLRs were significantly modulated by subjective loudness judgment even within the same stimulus intensity. All these findings indicated that high-frequency SSRs were different from both MLRs and LLRs in transient ERPs, thus supporting the possibility of oscillatory entrainment hypothesis to the generation of SSRs. Therefore, SSRs could be used to explore distinct neural responses as compared to transient ERPs, and help us reveal novel and reliable neural mechanisms of the human brain. © 2013 Zhang et al.

Huang J.,Xihua University | Cai J.,Southwest University | Li C.M.,Southwest University | Fu X.,Southwest University
Inorganic Chemistry Communications | Year: 2014

A series of chiral Mn (III) salen are anchored on ZnPS-PVPA modified by onium salt and characterized. In the asymmetric epoxidation of unfunctionalized olefins with m-CPBA and NaIO4 as oxidants, the supported catalysts demonstrate higher catalytic activities than those of the corresponding homogeneous chiral Mn (III) salen catalyst under the same conditions both for experimental scale and for large-scale reactions. Moreover, the catalysts are stable could be recycled nine times without significant loss of activity, which are provided with the potentiality for application in industry. © 2014 Published by Elsevier B.V.

Wang W.,Southwest University | Zou X.,University of Western Ontario
Journal of Mathematical Biology | Year: 2014

Based on the new findings in a recent experimental study (Lee et al., Nature 467, 82-86, 2010) that antibiotic resistant mutants of bacteria produce indoles to protect the wild strain bacteria, we propose a mathematical model to describe the evolution of the wild strain, resistant strain and indoles with limited nutrient. We distinguish two cases: (i) mutation is negligible and a resistant strain preexists; (ii) mutation is not negligible. For (i), we establish conditions for co-persistence of both strains, which indicate that the wild strain can survive with the help from the altruistic resistant strain, whereas it dies out in the absence of such a benefit. This consolidates the experimental findings in Lee et al. (Nature 467:82-86 2010). Further analysis and simulations also reveal some new phenomena not reported in Lee et al. (Nature 467:82-86 2010), that is, periodic oscillations of the populations may occur within certain range of the parameters, and there exists bistability in the sense that a stable positive periodic solution coexists with a stable positive equilibrium. © 2013 Springer-Verlag Berlin Heidelberg.

Chen Y.,Southwest University | Jiang B.,Chongqing University of Technology | Xiang Y.,Southwest University | Chai Y.,Southwest University | Yuan R.,Southwest University
Chemical Communications | Year: 2011

The presence of exonuclease III leads to direct recycling and reuse of the target DNA, which in turn results in substantial signal amplification for highly sensitive, label-free impedimetric detection of specific DNA sequences. © 2011 The Royal Society of Chemistry.

Huang G.,University of Hong Kong | Xiao P.,Southwest University | Hung Y.S.,University of Hong Kong | Zhang Z.G.,University of Hong Kong | Hu L.,Southwest University
NeuroImage | Year: 2013

Pain is a subjective first-person experience, and self-report is the gold standard for pain assessment in clinical practice. However, self-report of pain is not available in some vulnerable populations (e.g., patients with disorders of consciousness), which leads to an inadequate or suboptimal treatment of pain. Therefore, the availability of a physiology-based and objective assessment of pain that complements the self-report would be of great importance in various applications. Here, we aimed to develop a novel and practice-oriented approach to predict pain perception from single-trial laser-evoked potentials (LEPs). We applied a novel single-trial analysis approach that combined common spatial pattern and multiple linear regression to automatically and reliably estimate single-trial LEP features. Further, we adopted a Naïve Bayes classifier to discretely predict low and high pain and a multiple linear prediction model to continuously predict the intensity of pain perception from single-trial LEP features, at both within- and cross-individual levels. Our results showed that the proposed approach provided a binary prediction of pain (classification of low pain and high pain) with an accuracy of 86.3. ±. 8.4% (within-individual) and 80.3. ±. 8.5% (cross-individual), and a continuous prediction of pain (regression on a continuous scale from 0 to 10) with a mean absolute error of 1.031. ±. 0.136 (within-individual) and 1.821. ±. 0.202 (cross-individual). Thus, the proposed approach may help establish a fast and reliable tool for automated prediction of pain, which could be potentially adopted in various basic and clinical applications. © 2013 Elsevier Inc.

Xu J.,Southwest University | Jiang B.,Chongqing University of Technology | Xie J.,Chongqing University of Technology | Xiang Y.,Southwest University | And 2 more authors.
Chemical Communications | Year: 2012

The hybridizations between the HIV target DNA and the capture probes as well as the signal probes conjugated to the multi-invertase/nanoparticle composites lead to the conversion of sucrose to glucose, which is monitored by the personal glucometer and provides quantitative digital readings for point-of-care diagnosis of HIV DNA fragments. © 2012 The Royal Society of Chemistry.

Xiang Y.,Southwest University | Zhang H.,Southwest University | Jiang B.,Chongqing University of Technology | Chai Y.,Southwest University | Yuan R.,Southwest University
Analytical Chemistry | Year: 2011

The preparation and use of a new class of signal amplification label, quantum dot (QD) layer-by-layer (LBL) assembled polystyrene microsphere composite, for amplified ultrasensitive electronic detection of uropathogen-specific DNA sequences is described. The target DNA is sandwiched between the capture probes immobilized on the magnetic beads and the signaling probes conjugated to the QD LBL assembled polystyrene beads. Because of the dramatic signal amplification by the numerous QDs involved in each single DNA binding event, subfemtomolar level detection of uropathogen-specific DNA sequences is achieved, which makes our strategy among the most sensitive electronic approach for nucleic acid-based monitoring of pathogens. Our signal amplified detection scheme could be readily expanded to monitor other important biomolecules (e.g., proteins, peptides, amino acids, cells, etc.) in ultralow levels and thus holds great potential for early diagnosis of disease biomarkers. © 2011 American Chemical Society.

Xu J.,Southwest University | Jiang B.,Chongqing University of Technology | Su J.,Southwest University | Xiang Y.,Southwest University | And 2 more authors.
Chemical Communications | Year: 2012

By using exonuclease I and biobarcode nanoparticles, we describe a novel background current reduction strategy for amplified electrochemical detection of uropathogen specific sequences at ultralow concentrations. © The Royal Society of Chemistry 2012.

Xiang Y.,Southwest University | Qian X.,Southwest University | Jiang B.,Chongqing University of Technology | Chai Y.,Southwest University | Yuan R.,Southwest University
Chemical Communications | Year: 2011

One-spot signal-on and simultaneous electronic detection of lysozyme and adenosine is achieved based on target-induced release of aptamers and back-filling hybridization of the resulting single stranded DNAs with redox-tags conjugated aptamers. © The Royal Society of Chemistry 2011.

Zhang H.,Southwest University | Jiang B.,Chongqing University of Technology | Xiang Y.,Southwest University | Zhang Y.,Southwest University | And 2 more authors.
Analytica Chimica Acta | Year: 2011

A novel strategy for "signal on" and sensitive one-spot simultaneous detection of multiple small molecular analytes based on electrochemically encoded barcode quantum dot (QD) tags is described. The target analytes, adenosine triphosphate (ATP) and cocaine, respectively, are sandwiched between the corresponding set of surface-immobilized primary binding aptamers and the secondary binding aptamer/QD bioconjugates. The captured QDs yield distinct electrochemical signatures after acid dissolution, whose position and size reflect the identity and level, respectively, of the corresponding target analytes. Due to the inherent amplification feature of the QD labels and the "signal on" detection scheme, as well as the sensitive monitoring of the metal ions released upon acid dissolution of the QD labels, low detection limits of 30. nM and 50. nM were obtained for ATP and cocaine, respectively, in our assays. Our multi-analyte sensing system also shows high specificity to target analytes and promising applicability to complex sample matrix, which makes the proposed assay protocol an attractive route for screening of small molecules in clinical diagnosis. © 2010 Elsevier B.V.

Le Cook B.,Harvard University | Wayne G.F.,Harvard University | Kafali E.N.,Harvard University | Liu Z.,Southwest University | And 2 more authors.
JAMA - Journal of the American Medical Association | Year: 2014

IMPORTANCE: Significant progress has been made in reducing the prevalence of tobacco use in the United States. However, tobacco cessation efforts have focused on the general population rather than individuals with mental illness, who demonstrate greater rates of tobacco use and nicotine dependence. OBJECTIVES: To assess whether declines in tobacco use have been realized among individuals with mental illness and examine the association between mental health treatment and smoking cessation. DESIGN, SETTING, AND PARTICIPANTS: Use of nationally representative surveys of noninstitutionalized US residents to compare trends in smoking rates between adults with and without mental illness and across multiple disorders (2004-2011 Medical Expenditure Panel Survey [MEPS]) and to compare rates of smoking cessation among adults with mental illness who did and did not receive mental health treatment (2009-2011 National Survey of Drug Use and Health [NSDUH]). The MEPS sample included 32 156 respondents with mental illness (operationalized as reporting severe psychological distress, probable depression, or receiving treatment for mental illness) and 133 113 without mental illness. The NSDUH sample included 14 057 lifetime smokers with mental illness. MAIN OUTCOMES AND MEASURES: Current smoking status (primary analysis; MEPS sample) and smoking cessation, operationalized as a lifetime smoker who did not smoke in the last 30 days (secondary analysis; NSDUH sample). RESULTS: Adjusted smoking rates declined significantly among individuals without mental illness (19.2%[95%CI, 18.7-19.7%] to 16.5%[95%CI, 16.0%-17.0%]; P < .001) but changed only slightly among those with mental illness (25.3%[95%CI, 24.2%-26.3%] to 24.9%[95% CI, 23.8%-26.0%]; P = .50), a significant difference in difference of 2.3%(95%CI, 0.7%-3.9%) (P = .005). Individuals with mental illness who received mental health treatment within the previous year were more likely to have quit smoking (37.2%[95%CI, 35.1%-39.4%]) than those not receiving treatment (33.1%[95%CI, 31.5%-34.7%]) (P = .005). CONCLUSIONS AND RELEVANCE: Between 2004 and 2011, the decline in smoking among individuals with mental illness was significantly less than among those without mental illness, although quit rates were greater among those receiving mental health treatment. This suggests that tobacco control policies and cessation interventions targeting the general population have not worked as effectively for persons with mental illness. Copyright 2014 American Medical Association. All rights reserved.

Zhang B.,Fuzhou University | Liu B.,Fuzhou University | Liao J.,Southwest University | Chen G.,Fuzhou University | Tang D.,Fuzhou University
Analytical Chemistry | Year: 2013

A novel homogeneous immunoassay protocol was designed for quantitative monitoring of small molecular biotoxin (brevetoxin B, PbTx-2, as a model) by using target-responsive cargo release from polystyrene microsphere-gated mesoporous silica nanocontainer (MSN). Initially, monoclonal mouse anti-PbTx-2 capture antibody was covalently conjugated onto the surface of MSN (mAb-MSN), and the electroactive cargo (methylene blue, MB) was then trapped in the pores of mAb-MSN by using aminated polystyrene microspheres (APSM) based on the electrostatic interaction. Upon addition of target PbTx-2, the positively charged APSM was displaced from the negatively charged mAb-MSN because of the specific antigen-antibody reaction. Thereafter, the molecular gate was opened, and the trapped methylene blue was released from the pores. The released methylene blue could be monitored by using a square wave voltammetry (SWV) in a homemade microelectrochemical detection cell. Under optimal conditions, the SWV peak current increased with the increasing of PbTx-2 concentration in the range from 0.01 to 3.5 ng mL-1 with a detection limit (LOD) of 6 pg mL -1 PbTx-2 at the 3Sblank criterion. Intra- and interassay coefficients of variation with identical batches were ≤6% and 9.5%, respectively. The specificity and sample matrix interfering effects were acceptable. The analysis in 12 spiked seafood samples showed good accordance between results obtained by the developed immunoassay and a commercialized enzyme-linked immunosorbent assay (ELISA) method. Importantly, the target-responsive controlled release system-based electrochemical immunoassay (CRECIA) offers a promising scheme for the development of advanced homogeneous immunoassay without the sample separation and washing procedure. © 2013 American Chemical Society.

Zhang H.,Southwest University | Jiang B.,Chongqing University of Technology | Xiang Y.,Southwest University | Su J.,Southwest University | And 2 more authors.
Biosensors and Bioelectronics | Year: 2011

An electronic DNAzyme sensor for highly sensitive detection of Pb 2+ is demonstrated by coupling the significant signal enhancement of the layer-by-layer (LBL) assembled quantum dots (QDs) with Pb 2+ specific DNAzymes. The presence of Pb 2+ cleaves the DNAzymes and releases the biotin-modified fragments, which further hybridize with the complementary strands immobilized on the gold substrate. The streptavidin-coated, QD LBL assembled nanocomposites were captured on the gold substrate through biotin-streptavidin interactions. Subsequent electrochemical signals of the captured QDs upon acid dissolution provide quantitative information on the concentrations of Pb 2+ with a dynamic range from 1 to 1000nM. Due to the dramatic signal amplification by the numerous QDs, subnanomolar level (0.6nM) of Pb 2+ can be detected. The proposed sensor also shows good selectivity against other divalent metal ions and thus holds great potential for the construction of general DNAzyme-based sensing platform for the monitoring of other heavy metal ions. © 2011 Elsevier B.V.

Xu M.,University of Texas at Austin | Xu M.,Southwest University | Xiao P.,University of Texas at Austin | Stauffer S.,University of Texas at Austin | And 3 more authors.
Chemistry of Materials | Year: 2014

A single-phase crystalline Na3V2O2(PO 4)2F material has been prepared by the solvothermal method. Partial ion exchange between Na and Li was then used to form Na 3-xLixV2O2(PO4) 2F. The two materials were studied as positive cathodes by physical characterization, electrochemical measurements, and simulation. With density functional theory calculations, four stable phases of NaxV 2O2(PO4)2F were identified at the Na concentrations of x = 0, 1, 2, 3. The transitions between these phases give rise to three values of the Na chemical potential and three voltage plateaus for Na intercalation. The lower two voltages, corresponding to removal of the first two Na per formula unit, agree well with the corresponding experimental electrochemical measurements. Removal of the third Na, however, is not observed experimentally, because it is outside of the (4.8 V) stability window of the electrolyte. This observation is consistent with our calculations that show that the last Na will only be removed at 5.3 V, owing to the stability of the V-O bonding state and a strong Coulomb attraction between the Na and the anions. Computational modifications of the material were considered to activate the third Na with an oxidation energy in the electrolyte stability window, including swapping the anions from O and F to less-electronegative Cl and Br. The most promising material, Na3V2Cl2(PO 4)2F, is found to be stable and a good candidate as a Na cathode because all three Na ions can be reversibly removed without significant reduction in the cell potential or energy density of the material. Finally, we show that Li can partially replace Na and that these Li intercalate into the material with a higher rate owing to a lower diffusion barrier as compared to Na. © 2014 American Chemical Society.

Fu A.,Southwest University | Zhao Z.,Beijing Institute of Technology | Gao F.,Southwest University | Zhang M.,Southwest University
Pharmaceutical Research | Year: 2013

Purpose: The peptide-based delivery system constitutes a potent approach to overcome the limitations of drug delivery in vitro and in vivo. We recently proposed a novel peptide RDP, which enables brain-targeting delivery of proteins into neuronal cells. Here we investigate the possible internalization mechanism of RDP, and identify the therapeutic effects of functional proteins when linked with RDP in brain disease. Methods: The RDP fusion proteins are produced through recombinant DNA technology, and cell culture is used to investigate the uptake mechanism of RDP and its fusion protein. Experimental Parkinson's disease (PD) model is prepared in mice by intra-striatal injection of 6-hydroxydopamine, and is tested by apomorphine- and amphetamine-induced rotation. Results: The results suggest that the possible route for RDP cellular uptake might involve GABA receptor-dependent, clathrin-mediated endocytosis pathway. Additionally, the conjugate of RDP and glial cell-derived neurotrophic factor (GDNF) exhibits the neuroprotective effect in experimental PD animals, including reduction of apomorphine- and amphetamine-induced rotation following toxin administration. Conclusions: RDP may become an effective tool for the targeted delivery of proteins into brain for disease treatment. © 2013 Springer Science+Business Media New York.

Peng W.,University of Hong Kong | Hu L.,Southwest University | Zhang Z.,University of Hong Kong | Hu Y.,University of Hong Kong
PLoS ONE | Year: 2014

Transient painful stimuli could induce suppression of alpha oscillatory activities and enhancement of gamma oscillatory activities that also could be greatly modulated by attention. Here, we attempted to characterize changes in cortical activities during tonic heat pain perception and investigated the influence of directed/distracted attention on these responses. We collected 5-minute long continuous Electroencephalography (EEG) data from 38 healthy volunteers during four conditions presented in a counterbalanced order: (A) resting condition; (B) innoxious-distracted condition; (C) noxious-distracted condition; (D) noxious-attended condition. The effects of tonic heat pain stimulation and selective attention on oscillatory activities were investigated by comparing the EEG power spectra among the four experimental conditions and assessing the relationship between spectral power difference and subjective pain intensity. The change of oscillatory activities in condition D was characterized by stable and persistent decrease of alpha oscillation power over contralateral-central electrodes and widespread increase of gamma oscillation power, which were even significantly correlated with subjective pain intensity. Since EEG responses in the alpha and gamma frequency band were affected by attention in different manners, they are likely related to different aspects of the multidimensional sensory experience of pain. The observed contralateral-central alpha suppression (conditions D vs. B and D vs. C) may reflect primarily a top-down cognitive process such as attention, while the widespread gamma enhancement (conditions D vs. A) may partly reflect tonic pain processing, representing the summary effects of bottom-up stimulus-related and top-down subject-driven cognitive processes. Copyright: © 2014 Peng et al.

Song J.,University of Texas at Austin | Xu M.,University of Texas at Austin | Xu M.,Southwest University | Wang L.,University of Texas at Austin | Goodenough J.B.,University of Texas at Austin
Chemical Communications | Year: 2013

Monoclinic NaVOPO4 is explored as a cathode material for a sodium ion battery. It exhibits electrochemical activity operating at an average potential of 3.6 V (vs. Na+/Na) and delivers a reversible capacity of 90 mA h g-1 at 1/15 C. This journal is © The Royal Society of Chemistry 2013.

Yang X.,Southwest University | Zhuo Y.,Southwest University | Zhu S.,Southwest University | Luo Y.,Southwest University | And 2 more authors.
Biosensors and Bioelectronics | Year: 2014

An innovative and green strategy to synthesize carbon dots (CDs) with a quantum yield (QY) of nearly 19.8% has been successfully established for the first time. Subsequently, the possible fluorescence (FL) mechanism was elucidated by fluorescence, UV-vis, high resolution transmission electron microscope (HR-TEM), Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) analyses. Significantly, not only the precursor of CDs and whole synthesis procedure was green, but also the CDs obtained here exhibited various advantages including high fluorescent QY, excellent photostability, non-toxicity and satisfactory stability. Additionally, the CDs were employed for assaying Fe3+ based on direct interactions between Fe3+ and COOH, OH and NH2 of CDs, resulting in aggregations that facilitate to quench their fluorescence. The decrease of fluorescence intensity permitted detections of Fe3+ in a linear range of 5.0×10-9-1.0×10-4mol/L, with a detection limit of 1.7×10-9mol/L at a signal-to-noise ratio of 3, suggesting a promising assay for Fe3+. Eventually, the CDs were applied for cell imaging and coding, demonstrating their potential towards diverse applications. © 2014 Elsevier B.V.

Xu M.-W.,Southwest University | Niu Y.-B.,Southwest University | Bao S.-J.,Southwest University | Li C.M.,Southwest University
Journal of Materials Chemistry A | Year: 2014

A facile and effective redox reaction is developed to build various morphologies and crystal phases of manganese-based compounds by using two kinds of raw material, d-maltose and KMnO4. Interestingly, not only different morphologies, but also different crystal phases could be precisely tailored by adjusting the mass ratio of d-maltose to KMnO4. After thorough analysis of the observations, a reasonable formation mechanism is proposed to offer physico-chemical insight, while promoting opportunities to explore novel properties of manganese oxides for the fabrication of important functional devices. To demonstrate the process-structure-property relationship of the as-prepared nanomaterials, various morphologies of α-Mn 2O3, including cubic, spindle and fusiform were used for lithium ion batteries. The results indicate that the improved material morphology and porous structure can significantly improve the discharge capacity and cycling stability. © 2014 The Royal Society of Chemistry.

Fan Y.,Southwest University | Fan Y.,Luohe Medical College | Shi W.,Southwest University | Shi W.,Yangtze Normal University | And 2 more authors.
Journal of Materials Chemistry A | Year: 2014

Mesoporous material supported CoFe2O4 magnetic nanoparticles possess unique peroxidase/oxidase-like activity, and react with luminol to yield a novel chemiluminescence without the need of H 2O2. Their oxidase-like activity shows pH and support dependence, and could be reversibly controlled by their pH. This offers a new method for manipulating the enzyme-like activity of nanoparticles. © 2014 The Royal Society of Chemistry.

Jackson T.,Southwest University | Gao X.,Southwest University | Chen H.,Southwest University
International Journal of Obesity | Year: 2014

Objective:Neuroimaging studies have documented differences in neural responses to food cues in obese versus lean samples but little is known about weight status differences in responsiveness to other key features of obesogenic environments, particularly cues reflecting physical activity. To address this gap, patterns of activation related to visual depictions of sedentary activities and vigorous physical exercise were assessed in overweight (O-W) and average weight (A-W) samples via functional magnetic resonance imaging (fMRI).Methods:Thirteen O-W and 13 A-W Chinese women were instructed to imagine engaging in 90 physical exercise activities and 90 sedentary activities and to watch 90 landscape images presented during three runs of an fMRI scan within a cross-sectional design.Results:Behavioral results indicated O-W women endorsed more negative attitudes toward physical activity than A-W did. Imaging analyses indicated that body mass index had a significant negative association with activation of the right putamen and a positive correlation with activation in the right medial frontal gyrus, specifically Brodmann Area 10 in the exercise-sedentary image contrast condition. For the sedentary-control contrast, significantly less activation in an insula area related to negative affect was observed for the O-W group. Finally, for the exercise-control contrast, O-W women also displayed comparatively weaker activation in a cingulate gyrus area implicated in kinesthetic memory of body movements and the re-experiencing real events.Conclusion:Together, results supported contentions that exposure to depictions of physical exercise corresponds to reduced activation of reward centers and heightened activation in regions associated with negative affect regulation among O-W women compared with leaner peers. © 2014 Macmillan Publishers Limited All rights reserved.

Zhang F.X.,Southwest University
Advanced Materials Research | Year: 2014

This paper focus on hierarchical scheduling for real-time applications for open embedded system environments constructed by the total bandwidth server, according to its algorithms, when a job at the head of the server's ready queue completes, the server budget is replenished immediately if the ready queue is not empty. This paper gives some examples to the solutions proposed by Deng et al for a two-level hierarchical scheduling model in which the global level of the system is earliest deadline first, and the local scheduler could be any algorithm. The scheduling algorithms and schedulability analysis for the tasks are reviewed in an open system where the applications could be modeled as executing on a slow processor. © (2014) Trans Tech Publications, Switzerland.

Zhou J.,Southwest University
Computers and Mathematics with Applications | Year: 2013

In this paper, a reaction-diffusion bimolecular model with autocatalysis and saturation law is investigated. Firstly, we provide some conditions for the stability/Turing instability of the constant positive solution. Then we mainly consider Hopf bifurcations and steady state bifurcations which bifurcate from the unique constant positive solution of the system. Our results suggest the existence of spatially non-homogeneous periodic orbit and non-constant positive steady state solutions, which implies the possibility of rich spatiotemporal patterns in this diffusive bimolecular model. Numerical examples are presented to support our theoretical analysis. Furthermore, non-existence of non-constant steady state is investigated in terms of parameters. © 2013 Elsevier Ltd. All rights reserved.

Zheng X.,Southwest University | Fang Y.,Southwest University
Proceedings of 2010 International Conference on Intelligent Control and Information Processing, ICICIP 2010 | Year: 2010

As the construction of malicious software has shifted from novices to commercial, malware attacks grew considerably in frequency and traditional antivirus software fails to detect many modern malware and its increasing complexity has resulted in vulnerabilities that are being exploited by many malwares. In this paper we advocate an artificial immune system (AIS) based cloud security model for malware detection as in-cloud service instead of local-based antivirus software. We discuss how cloud based cloud security model can effectively coexist with traditional scanning technologies, and what are the advantages and limitations of this new approach. In the model, we combine local-host based detector in host agent with multiple detection engines in the cloud. This model enables detection of malware by multiple detection engines in the cloud in parallel. To explore and validate the idea we construct a prototype which includes a lightweight host agent, multiple detection engines in the network, and an AIS-based detection engine. We evaluate the performance and efficacy of the system using a dataset of 1500 malware samples through Arbor Malware Library (AML) covering a one year period. © 2010 IEEE.

Wang J.,Southwest University | Liu C.,Southwest University | Shuai Y.,Southwest University | Cui X.,Southwest University | Nie L.,Southwest University
Colloids and Surfaces B: Biointerfaces | Year: 2014

In order to find new composite materials for the controlled release of drugs, a series of novel pH sensitive konjac glucomannan/sodium alginate (KGM/SA) and KGM/SA/graphene oxide (KGM/SA/GO) hydrogels were prepared, using GO as a drug-binding effector for anticancer drug loading and release. The hydrogels were characterized using Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). The effects of component ratio and pH on the swelling properties of hydrogels were studied. The release amount of 5-fluorouracil (5-FU) incorporated into KGM/SA/GO-3 hydrogels was about 38.02% at pH 1.2 and 84.19% at pH 6.8 after 6. h and 12. h, respectively. Therefore, the release rate of 5-FU from the functionalized KGM/SA using GO could be effectively controlled, Go has a great potential to be a promising drug-binding effector for hydrogel functionalization in drug delivery. © 2013 Elsevier B.V.

Wang J.-L.,Southwest University | Jackson L.A.,Michigan State University | Zhang D.-J.,Southwest University
Computers in Human Behavior | Year: 2011

Based on theory and previous research, we examined relationships among gender, social anxiety, self-disclosure, quality of real-world friendships and online communication by Chinese adolescent Internet users. Results indicated that online communication and self-disclosure are not related to quality of friendship, and online communication is positively related to self-disclosure. For adolescent boys and adolescents with high social anxiety, online communication can explain more variance in users' self-disclosure, indicating that gender and social anxiety moderate the relationship between online communication and online self-disclosure. © 2011 Elsevier Ltd. All rights reserved.

Wang Y.,Southwest University | Zhen S.J.,Southwest University | Zhang Y.,Southwest University | Li Y.F.,Southwest University | Huang C.Z.,Southwest University
Journal of Physical Chemistry C | Year: 2011

With unique structure and extraordinary properties, graphene has attracted tremendous attention in a wide range of fields recently. In terms of its biomedical applications, graphene has been used to be biosensors and drug carriers, including in vitro and in vivo studies. Therefore, how to clarify the behaviors of graphene in organism is a significant and long-term challenge. For that purpose, fabricating graphene-based materials which can give off some measurable signals become a fascinating topic. In this study, we report a facile noncovalent strategy to fabricate metal nanoparticle/graphene oxide (MNP/GO) hybrids, which can be used to directly illuminate graphene for optical imaging by employing the strong localized surface plasmon resonance (LSPR) light scattering of MNPs as an effective signal reporter, and thus the profiles of graphene can be observed with a dark-field microscope. The formation of MNP/GO hybrids has been confirmed successfully, and these new nanocomposites assembled from individual building blocks can be promising candidates for the applied purposes of biological imaging, drug delivery, and cancer therapy owing to their collective properties. © 2011 American Chemical Society.

Zhang H.,Southwest University | Guan L.,Southwest University | Qi M.,Southwest University | Yang J.,Southwest University
PLoS ONE | Year: 2013

Researchers have suggested that certain individuals may show a self-positivity bias, rating themselves as possessing more positive personality traits than others. Previous evidence has shown that people evaluate self-related information in such a way as to maintain or enhance self-esteem. However, whether self-esteem would modulate the time course of self-positivity bias in explicit self-evaluation has never been explored. In the present study, 21 participants completed the Rosenberg self-esteem scale and then completed a task where they were instructed to indicate to what extent positive/negative traits described themselves. Behavioral data showed that participants endorsed positive traits as higher in self-relevance compared to the negative traits. Further, participants' self-esteem levels were positively correlated with their self-positivity bias. Electrophysiological data revealed smaller N1 amplitude and larger late positive component (LPC) amplitude to stimuli consistent with the self-positivity bias (positive-high self-relevant stimuli) when compared to stimuli that were inconsistent with the self-positivity bias (positive-low self-relevant stimuli). Moreover, only in individuals with low self-esteem, the latency of P2 was more pronounced in processing stimuli that were consistent with the self-positivity bias (negative-low self-relevant stimuli) than to stimuli that were inconsistent with the self-positivity bias (positive-low self-relevant stimuli). Overall, the present study provides additional support for the view that low self-esteem as a personality variable would affect the early attentional processing. © 2013 Zhang et al.

Chen L.J.,Southwest University | Song Q.L.,Southwest University | Xiong Z.H.,Southwest University | Huang J.H.,Southwest University | He F.,Southwest University
Solar Energy Materials and Solar Cells | Year: 2011

An efficient single layer organic solar cell based on plain buckminsterfulerence (C60) has been fabricated. By inserting a very thin N,N′-bis(naphthalene-1-yl)-N,N′-bis(phenyl)benzidine layer between the indium tin oxide and single C60 active layer, a short-circuit current of 1.98 mA/cm2 and an open-circuit voltage of 0.52 V are obtained under 100 mW/cm2 AM1.5G simulated illumination. The highest power conversion efficiency of 0.414% based on plain C60 is thus demonstrated, which is the first step to realize an environment-friendly energy source. © 2010 Elsevier B.V. All rights reserved.

Luo J.H.,Southwest University | Li B.L.,Southwest University | Li N.B.,Southwest University | Luo H.Q.,Southwest University
Sensors and Actuators, B: Chemical | Year: 2013

A new electrochemical sensor was developed based on polyethyleneimine- functionalized graphene oxide (PEI-rGO) modified glassy carbon electrode (PEI-rGO/GCE). The synthetic positive charged PEI-rGO had good electron transfer ability, large specific surface area, prominent biocompatibility, and excellent adsorption. Its morphology and microstructure was characterized by scanning electron microscopy. The new electrode was firstly used for the detection of gallic acid, which exhibits superior performance in comparison to the bare glassy carbon electrode and graphene oxide modified glassy carbon electrode. The experimental conditions such as pH, adsorption time, and scan rate were optimized for the determination of gallic acid. Under optimum conditions, the linear regression equation of gallic acid was ip = 12.76c - 11.44 (ip: μA, c: mg/L, R = 0.9887) from 0.1 to 10 mg/L with a detection limit (S/N = 3) of 0.07 mg/L. The method has been successfully applied to the determination of gallic acid in samples of green tea and black tea. © 2013 Elsevier B.V.

Hu F.,Southwest University | Chen S.,Southwest University | Yuan R.,Southwest University
Sensors and Actuators, B: Chemical | Year: 2013

This paper reported the production of magnetic core-shell composite microspheres (Fe3O4@SiO2-Au@mSiO2) which consist of a silica-protected magnetite particle core, an active gold nanoparticle transition layer and an outer mesoporous silica shell with pore channels. During the synthesis of the microspheres, the shape of the nanocomposite was changed from hexagons or quadrangles of Fe3O 4 to well-defined spheres of Fe3O4@SiO 2-Au@mSiO2. The synthesized microspheres were characterized by scanning electron microscopy, transmission electron microscopy and X-ray photoelectron spectroscopy. A strategy was proposed for the fabrication of reagentless immunosensors based on direct electrochemistry of glucose oxidase (GOD), which employed multiwall carbon nanotubes and the prepared Fe3O4@SiO2-A6u@mSiO2 as immobilization matrix. The immobilized GOD exhibited direct electrochemistry with a rate constant of 1.8 s-1. The cyclic voltammetric (CV) and differential pulse voltammetric (DPV) peak currents of GOD decreased linearly with the increase of carbohydrate antigen 19-9 (CA19-9) concentrations from 0.01 to 1.11 U mL-1 and 11.11 to 476.11 U mL-1 with a relatively low detection limit of 0.004 U mL-1. Furthermore, this strategy avoided the addition of electron transfer mediator, which simplified the immunoassay procedure and decreased the analytical time. © 2012 Elsevier B.V. All rights reserved.

Wang S.,Southwest University | Feng J.,South China University of Technology | Tse C.K.,Hong Kong Polytechnic University
IEEE Signal Processing Letters | Year: 2014

In this letter, a new class of cubature Kalman filters (CKF) based on a spherical simplex-radial rule is proposed to further improve accuracy and efficiency of the traditional CKF. The transformation group of the regular simplex and the moment matching method are utilized to compute the spherical and radial integrals, respectively. In addition, with the increase of the state dimension, the new CKF of the fifth degree uses fewer quadrature points than the traditional CKF with the same degree. Simulations on moments calculation and nonlinear state estimation show that the proposed CKFs can achieve higher accuracy and better efficiency than the traditional CKFs. © 2013 IEEE.

Wang T.,Southwest University | Zhu X.-K.,Southwest University | Xue X.-T.,Southwest University | Wu D.-Y.,Southwest University
Carbohydrate Polymers | Year: 2012

A hydrogel sheet composed of chitosan, honey and gelatin (HS; 0.5:20:20, w/w) was developed as a burn wound dressing. HS showed powerful antibacterial efficacy up to 100% to Staphylococcus aureus and Escherichia coli, significantly superior to chitosan and honey used separately. A series of toxicological evaluations demonstrated that HS is not toxic and not irritant to skin and body. An animal burn model was performed on the back of New Zealand rabbit, and treated, respectively, with HS, MEBO ® ointment (Shantou MEBO Pharmaceuticals Co., Ltd., Guangdong, China) and sterile gauze. The macroscopic image and histopathology were examined. The results showed that HS had a significant effect on wound contraction with the shortest treatment duration of 12 days compared to MEBO ® ointment and no treatment. Histological examination revealed that HS-treated burn wound was repaired with intact epidermis on day 12, but the wound treated with MEBO did not completely heal. Therefore, HS demonstrated its potential as a treatment. © 2011 Elsevier Ltd All rights reserved.

Wei S.-Y.,Southwest University | Chen Y.,Southwest University | Xu X.-Y.,Southwest University
Chinese Journal of Natural Medicines | Year: 2014

Contemporary pharmacological research has demonstrated that puerarin, the most important phytoestrogen extracted from Pueraria lobata(Willd.) Ohwi, has protecting functions on the cardiovascular system, nervous system, osteoporosis, liver injury, and inflammation in vivo and in vitro. Most of these research studies focused on inhibiting oxidative stress and apoptosis through regulating various bioactivators and signal pathways. Among these, superoxide dismutase (SOD), endothelial nitric oxide synthase (eNOS) and malondialdehyde (MDA), and PI3K/Akt, MAPK, and NF-κB are of great importance. The data cited in this review were mainly obtained from articles listed in PubMed and Elsevier SDOL published from 1959 to 2013, and the search term used was "puerarin". © 2014 China Pharmaceutical University.

Zhang T.,Southwest University | Yang Y.,Southwest University | Xie D.,Southwest University
International Journal of Energy Research | Year: 2015

China, one of the countries in the world abundant in agricultural wastes, has a great potential for rural biogas production. As a strategy for building a new socialist countryside and sustainable agriculture in rural China, the development of biogas is an important means to convert agricultural wastes to clean and safe energy, thereby reducing the need for fossil fuel and alleviating environmental pollution. This study presents an assessment of the biogas production potential, its current development state, and perspectives of agricultural wastes in rural China. Estimated data show that annual biogas potential from agricultural wastes is approximately (3350.58±669.28)×108m3 (equal to 239.22±47.78 million tons of equivalent standard coal); such potential has been underutilized in the past. By analyzing and summarizing the direction for future development and various benefits of rural biogas in China, we present burning questions and countermeasures for biogas development and recommend that the future development of rural biogas in China should focus on both household-scale and large-scale development, giving priority to the establishment of large-scale biogas engineering and biogas plants, improvement of biogas comprehensive utilization level, and construction of a reticular model of systemized green agricultural engineering linked with biogas to solve completely the problem of agricultural waste accumulation and improve the living conditions in rural China. © 2015 John Wiley & Sons, Ltd

Zeng J.-B.,Southwest University | Li K.-A.,Southwest University | Du A.-K.,Chongqing Academy of Science and Technology
RSC Advances | Year: 2015

Poly(lactic acid) (PLA) is regarded as one of the most promising bio-based and biodegradable polymers, due to its excellent biodegradability, biocompatibility, renewability, high strength, and easy processibility. However, disadvantages such as brittleness and relatively high cost have restricted its applications significantly. Polymer blending provides an economic and efficient way to modify the properties of PLA. Most shortcomings of PLA are theoretically surmountable by blending with abundant polymers with various properties. But, unfortunately, PLA is thermodynamically immiscible with most existing polymers. High-performance PLA-based blends are usually unanticipated by direct blending. In order to obtain PLA-based blends with excellent overall properties, compatibilization is required during polymer blending. Various strategies have been employed or developed to compatibilize PLA blends with different polymers, as reported in recent studies. This article aims to review the development in compatibilization strategies employed in PLA-based blends. © 2015 The Royal Society of Chemistry.

Zhao X.J.,Southwest University | Yang J.H.,Southwest University | Liu Y.,Southwest University | Gao P.F.,Southwest University | Li Y.F.,Southwest University
RSC Advances | Year: 2014

A family of leaf-shaped lanthanide metal-organic coordination polymers, Tb2-xEux(BDC)3(H2O)n (0 ≤ x ≤ 2, BDC = 1,4-benzenedicarboxylate), was prepared through a surfactant-assisted one step method at room temperature, which showed tunable fluorescence emission and smart response toward aldehydes. © 2014 The Royal Society of Chemistry.

Zhong J.,Southwest University | Guan Z.,Southwest University | He Y.-H.,Southwest University
Catalysis Communications | Year: 2013

A novel catalyst combining pyrrolidinyl and cyclohexanediamine was designed and synthesized. Only 5 mol% of catalyst loading was required for enantioselective Michael additions of cyclohexanone and nitroolefins affording desired γ-nitroketones with > 99% yield, up to 91% ee and up to > 99/1 dr under mild conditions. The enantioselectivity of the product could be further improved to > 99% ee after a single recrystallization in petroleum ether/ethyl acetate. © 2012 Elsevier B.V.

Wang Q.,Southwest University | Huang X.,Southwest University | Long Y.,Southwest University | Wang X.,Southwest University | And 5 more authors.
Carbon | Year: 2013

Carbon dots (CDs) are luminescent nanomaterials with unique properties that show great potential in many applications. Herein, hollow CDs (HCDs) are prepared from bovine serum albumin by solvothermal reaction. The obtained HCDs are ca. 6.8 nm in diameter and have a quantum yield of 7%. Their bright photoluminescence means they can be used for cellular imaging. Structure and composition analyses indicate that the HCDs possess a hollow structure with a pore size of ca. 2 nm. The HCDs are used as a delivery system for doxorubicin (DOX). The DOX-HCD drug delivery system exhibits pH-controlled release, and is rapidly taken up by cells. Because of their specific nanostructure and photoluminescence properties, the multifunctional HCDs prepared here show potential for application in both cell imaging and cancer therapy. © 2013 Elsevier Ltd.

Zheng L.,Southwest University | Hart T.A.,Ryerson University | Hart T.A.,University of Toronto | Zheng Y.,Southwest University
Archives of Sexual Behavior | Year: 2015

Gay men across a variety of countries label themselves by their preferences for insertive anal intercourse or receptive anal intercourse. A “top” is defined as someone who prefers the insertive role, a “bottom” as someone who prefers the receptive role, and “versatile” as someone who has no preferences regarding anal sex role. Previous studies documented that tops showed a masculine profile and bottoms showed a feminine profile in gendered personality traits. In this study, we examined the association among sexual self-label groups and empathizing–systemizing (E–S) cognitive styles among 509 gay men across multiple cities in China. There were significant differences in systemizing among sexual self-label groups, with tops scoring higher on systemizing than bottoms and versatiles. Tops were more likely to have S > E and high E and S cognitive styles than bottoms. Bottoms were more likely to have E > S and low E and S cognitive styles than tops. There was a significant indirect effect of systemizing on sexual self-label through Self-MF. There was also a significant indirect effect of sexual self-label on systemizing through Self-MF. The findings suggest that sexual self-labels among adult gay and bisexual men may reflect more than preferences for anal sex. © 2015, Springer Science+Business Media New York.

Zheng L.,Southwest University | Zheng Y.,Southwest University
Archives of Sexual Behavior | Year: 2015

Previous studies have documented the correlation between preferences for male facial masculinity and perceived masculinity: women who rate their male partner as more masculine tend to prefer more masculine faces. Men’s self-rated masculinity predicts their female partner’s preference for masculinity. This study examined the association between other trait preferences and preference for male facial masculinity among 556 gay and bisexual men across multiple cities in China. Participants were asked to choose the three most important traits in a romantic partner from a list of 23 traits. Each participant was then asked to choose a preferred face in each of 10 pairs of male faces presented sequentially, with each pair consisting of a masculinized and feminized version of the same base face. The results indicated that preferences for health and status-related traits were correlated with preferences for male facial masculinity in gay and bisexual men in China; individuals who were more health- or status-oriented in their preferences for a romantic partner preferred more masculine male faces than individuals with lower levels of these orientations. The findings have implications for the correlated preferences for facial masculinity and health- and status-related traits and may be related to perceived health and dominance/aggression of masculine faces based on a sample of non-Western gay and bisexual men. © 2014, Springer Science+Business Media New York.

Gu W.-W.,Southwest University
Guangxue Jingmi Gongcheng/Optics and Precision Engineering | Year: 2014

A transmitted fluorescence detector induced by a Light Emitting Diode (LED) was established for integrating in a microfluidic cell chip. The detector overcomes the problems of system bulky in larger size, higher energy consumption and low coupling efficiency for inducing optical path, detection zone and fluorescence optical path. The angle for induced fluorescence optical path was designed to be 135°. The exciting light produced by the LED passed through an optical lens, an exciting light filter and a diaphragm aperture with a diameter of 200 μ m, and then reached the detection zone of microfluidic chip. The induced fluorescence light and stray light passed through emitting high pass interference thin film filter fabricated at the back of the microfluidic chip, and finally was collected by a photomultiplier (PMT). The performance of the fluorescence detection micro system was verified by using HepG2 hepatoma carcinoma cells as samples. The experimental results show when the working current for LED and the control voltage for PMT are respectively set to be 200 mA and 3.5 V, the output is a peak signal which is obviously distinguished from background noise. 8 peak signals with an average value of 0.7 V are obtained within 250 s, which agrees with that from a fluorescence microscope. It shows the detection system realizes the function of cell counting detection, and is a new technological approach to micro total cell analysis systems.

He Q.,Southwest University
Applied Mechanics and Materials | Year: 2014

In order to achieve a proper design and control, it is necessary to have an exact model of boost converter. In this paper, the mathematic model of boost converter is proposed by the state-space average method. In the next step, the open-loop transfer function model without compensation is deduced in detail according to the mathematic model of the boost converter, the controller is designed according to frequency domain. The phase margin and magnitude margin of the open-loop system of the boost converter with compensator have both been increased. After compensating, the control system becomes stable. Using Matlab 7.1, the simulation of the control system of boost converter was implemented. The simulation results of control system confirm that the controller can reduce steady state error and resist power supply disturbance. © (2014) Trans Tech Publications, Switzerland.

Yang Y.,Southwest University | He Y.-H.,Southwest University | Guan Z.,Southwest University | Huang W.-D.,Southwest University
Advanced Synthesis and Catalysis | Year: 2010

A new, simple bifunctional, recoverable and reusable L-prolinamide organocatalyst that promotes aldol reactions while achieving a respectable level of enantioselectivity is reported. This organocatalyst is applicable to the reactions of a wide range of aromatic and heteroaromatic aldehydes with cyclic and acyclic ketones, and the anti-aldol products could be obtained with up to 99:1 anti/syn ratio and 98% ee. The catalyst can be easily recovered and reused, and only a slight decrease of enantioselectivity was observed for five cycles. This novel catalyst can be efficiently used in large-scale reactions with the enantioselectivity being maintained at the same level, which offers a great possibility for application in industry. © 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

He Q.,Southwest University
Applied Mechanics and Materials | Year: 2014

A control system for DC motor should be designed to meet the desired performance objectives with the smallest control energy. LQR controller can satisfy the requirement. In this paper, the state space model of DC motor control system is proposed. The key problem to apply LQR controller is to choose the correct weighted matrix Q and R of performance index. At present, there is no formulaic approach for this problem. This kind of LQR controller based on PSO algorithms, which can obtain satisfying control results, is presented for DC motor control system. Using Matlab 7.1, the simulation of the DC motor control system is implemented. The simulation results of it confirm that the LQR controller can reduce steady state error, improve response speed, and resist power supply disturbance. © (2014) Trans Tech Publications, Switzerland.

Qi W.J.,Southwest University | Wu D.,Southwest University | Ling J.,Southwest University | Huang C.Z.,Southwest University
Chemical Communications | Year: 2010

Melamine can be sensitively detected in aqueous medium through its selective interaction with polythymine (polyTn) modified gold nanoparticles (AuNPs) by forming triple H-bonds, which results in aggregation of the polyTn-stabilized AuNPs, displaying variations of localized plasmon resonance features such as colour change from red to purple and enhanced localized surface plasmon resonance light scattering (LSPR-LS) signals. © 2010 The Royal Society of Chemistry.

Yang H.,Southwest University | Huang C.Z.,Southwest University
RSC Advances | Year: 2014

Nanofiber matrix loading Ag nanoparticles have been applied for SERS measurements with the limitation of poor reproducibility. By introducing polymethacrylic acid (PMAA) into the electrospun solutions in this contribution, fairly uniform PMAA/poly(N-vinylpyrrolidone) (PVP) ultrafine fibers containing silver nanoparticles (AgNPs) were successfully prepared via electrospinning by means of in situ photo reduction of silver ions. PMAA can significantly improve the absorbing amounts of silver ions in the polymer owing to its linear structure with abundant carboxyl groups, which makes the content and size of formed AgNPs in the polymer matrix to be easily controlled under different light sources (such as desk lamp, 365 nm UV lamp, and 254 nm UV lamp). With the electrospun AgNPs/PMAA/PVP fibrous membranes, malachite green (MG), a significant environmental organic pollutant known for its genotoxicity, was successfully detected with RSD values below 0.2% through SERS signals. © the Partner Organisations 2014.

Wang Y.,Southwest University | Li Y.F.,Southwest University | Wang J.,Southwest University | Sang Y.,Southwest University | Huang C.Z.,Southwest University
Chemical Communications | Year: 2010

We report a novel, simple, highly selective and versatile approach for the end-to-end assembly of gold nanorods (GNRs) by means of the specific molecular recognition between thymine-rich (T-rich) oligonucleotides and mercury(ii). © 2010 The Royal Society of Chemistry.

Ma X.,Southwest University | Wang Y.,Southwest University | Wang W.,Southwest University | Cao J.,Southwest University
Catalysis Communications | Year: 2010

In this paper, cinchonidine (CD) with the different arm lengths (n = 2-6) was covalently immobolized onto the backbone of zirconium phosphonate to afford a series of mesoporous zirconium phosphonates (4a-e) for the first time. It was found that zirconium phosphonates (4a-e) were conglomerated with the globular aggregates with the diameters of about 100-150 nm and possessed the surface areas of 20.8-36.2 m2 g-1, pore volumes of 0.219-0.498 cc g-1 and average pore sizes of 11.7-41.5 Å. The TEM images of 4a-e in organic solvent showed that these materials were easily swollen into the filiform structure with the length about several micrometers and thickness about 30-50 nm. In the field of the asymmetric catalysis, the preliminarily enantioselective addition of diethylzinc to various aldehydes catalyzed by 4a-e (35-62%e.e. in the 68-92% yield) was carried out and can be reused ten times without loss in the yield and enantiomeric excess. © 2009 Elsevier B.V. All rights reserved.

Hu Y.,Southwest University | He Y.-H.,Southwest University | Guan Z.,Southwest University
Catalysis Communications | Year: 2010

Primary natural amino acid l-tryptophan was used, for the first time, as a catalyst in Knoevenagel condensations of aliphatic, aromatic, hetero-aromatic and α,β-unsaturated aldehydes with less reactive acetylacetone and ethyl acetoacetate. The reactions were carried out at room temperature and gave good yields. It is a convenient entry for preparation of functionalized trisubstituted alkenes and α,β,γ,δ-unsaturated carbonyl compounds. © 2010 Elsevier B.V. All rights reserved.

Li T.,Southwest University | Wang Z.,Southwest University | Xie H.,Southwest University | Fu Z.,Southwest University
Journal of Chromatography B: Analytical Technologies in the Biomedical and Life Sciences | Year: 2012

Epinephrine (EP) is one of the most important neurotransmitters and hormones. Some previous literatures show that there is a close relation between its release and smoking. To compare the levels of EP in urines of smokers and nonsmokers, a sensitive chemiluminescence (CL) system, luminol-diperiodatocuprate (III) (K5[Cu(HIO6)2], DPC), has been developed and validated for the determination of EP after CE separation. The DPC-luminol-EP CL reaction showed very intensive emission and fast kinetic characteristics, thus led to a high sensitivity in the flow-through detection mode for capillary electrophoresis. With the peak height as a quantitative parameter, the relative CL intensity was linear with the EP concentration in the range of 2.0-400ng/mL, with a limit of detection of 0.82ng/mL (S/N=3). The reproducibility was assessed by intra- and inter-day relative standard deviations (RSDs) for 11 replicate determinations of EP standard samples at low, medium and high concentrations. The intra- and inter-day RSDs for CL signals were 5.5%-6.6% and 6.1%-7.5%, respectively, and those for migration times were 3.4%-5.8% and 4.3%-6.3%, respectively. The presented method was successfully applied to the determination of EP in EP injection and urine samples of smokers and nonsmokers. The recovery test results for urine samples ranged from 86.5 to 112.0%, which demonstrated the reliability of this method. The results for urine sample detection indicate that the average level of EP in the urines of the smoker group is obviously higher than that in the urines of the nonsmoker group, which may demonstrate that smoking can stimulate the release of EP in human body. © 2012 Elsevier B.V.

Zou X.,Southwest University | Fu X.,Southwest University | Li Y.,Southwest University | Li X.,Southwest University | And 3 more authors.
Advanced Synthesis and Catalysis | Year: 2010

Chiral Jacobsen's catalyst was axially immobilized onto phenoxy-modified zirconium poly(styrene-phenylvinylphosphonate)phosphate (ZPS-PVPA). The immobilized catalysts show comparable ee values for asymmetric epoxidation of styrene and much higher ee values for a-methylstyrene (73.7% vs. 54.0%) and indene (99.9% vs. 65.0%) than the homogeneous Jacobsen's catalyst. Moreover, the assynthesized catalysts are relatively stable and can be recycled at least five times without significant loss of activity and enantioselectivity. A point worth emphasizing is that the heterogeneous catalysts afforded remarkable increases of conversion and ee values in the absence of expensive O-coordinating axial bases for the asymmetric epoxidation of olefins, especially for the epoxidation of α-methylstyrene (conversion: from 24.3% to 99.9%; ee: from 29.4% to 73.7%), which may overcome the last obstacle for the potential industry application of chiral Jacobsen's catalyst. © 2010 Wiley-VCH Verlag GmbH & Co. KGaA.

Xie X.Y.,Southwest University | Luo H.Q.,Southwest University | Li N.B.,Southwest University
Journal of Electroanalytical Chemistry | Year: 2010

This paper describes the fabrication, characterization and application of a bismuth/poly (p-aminobenzene sulfonic acid) (Bi/poly(p-ABSA)) composite film-coated glassy carbon electrode for the electrochemical determination of azo compounds. This electrode was fabricated by depositing bismuth on the poly(p-ABSA) modified electrode at -0.9 V. Azo compounds such as 1-(2-pyridylazo)-2-naphthol (PAN), 4-(2-pyridylazo)-resorcinol (PAR) and azobenzene were determined on this electrode by differential pulse voltammetry. Factors influencing the determination performance including the film preparation and solution pH have been optimized. This new electrode presented well-defined, reproducible and sharp determination signals. The results confirmed that the Bi/poly(p-ABSA) electrode offered high-quality stripping performance compared with the bismuth film electrode. Under the optimum conditions, the detection limits of PAN, PAR and azobenzene were 4.1 × 10-8, 3.3 × 10-8 and 3.8 × 10-8 mol L-1, respectively. The influence of foreign substances on the signal was studied and the new electrode was successfully applicable to analysis of azo compounds in real beverage samples. © 2009 Elsevier B.V. All rights reserved.

Yang G.,Southwest University | Zhou L.,Southwest University
Catalysis Science and Technology | Year: 2016

Proline is an efficient and versatile catalyst for organic reactions while a number of issues remain controversial. Here, ab initio and density functional calculations were used to unravel a few key issues of catalytic mechanisms in water and organic solvents. Zwitterionic proline that predominates in water and DMSO is assumed to be the active conformation for catalysis, and reactivity differences in two solvents are revealed. Meanwhile, an abundance of experimental observations can be finely interpreted by the present computational results, including those seemingly contradictory. Although bearing lower activation barriers than that in DMSO, the production of enamines and further aldol products in water will be blocked at an early stage (J. Am. Chem. Soc., 2006, 128, 734) because the reaction in water is significantly driven towards acetyl formation that is kinetically and thermodynamically preferred. Due to significant promotion of the rate-determining proton transfer step, aldol reactions in organic solvents can be obviously initiated by the addition of some water (Angew. Chem., Int. Ed., 2004, 43, 1983). In order to show catalytic effects in water (an obviously environmentally benign solvent)roline has to be structurally modified so that canonical structures can be the principal (or sole) conformations, which is in line with the analyses of all proline-based catalysts available in water (e.g., J. Am. Chem. Soc., 2006, 128, 734, Catal. Commun., 2012, 26, 6). Thus, the present results provide insightful clues to mechanisms of proline-mediated catalysis as well as future design of more efficient catalysts. © The Royal Society of Chemistry 2016.

Kamruzzaman M.M.,Southwest University
14th International Conference on Computer and Information Technology, ICCIT 2011 | Year: 2011

In this paper, performance of a Turbo coded OFDM wireless link is evaluated in the presence of Rayleigh fading for SISO, SIMO, MISO and MIMO system. Data are encoded using turbo encoder then modulated by QPSK or 16 QAM or 64 QAM and further encoded using STBC, and the encoded data are split into n streams which are modulated by OFDM and simultaneously transmitted using n transmit antennas. It is observed that the turbo coded SISO-OFDM system provides 21 dB coding gain at 10 -4, turbo coded SIMO-OFDM system provides 20 and 13 db coding gain for 2 and 4 receive antennas respectively at a BER of 10 -6, turbo coded MISO-OFDM system provides 17 and 12 dB coding gain for 2 and 4 transmit antennas respectively at a BER of 10 -6 and turbo coded MIMO-OFDM system provides 11 to 13 dB coding gain for different combination of transmit and receive antennas at BER 10 -6 compare to uncoded SISO-OFDM, SIMO-OFDM, MISO-OFDM and MIMO-OFDM system. © 2011 IEEE.

Lu Y.,Southwest University | Peng Z.,Southwest University
Extremes | Year: 2016

In this paper, joint limit distributions of maxima and minima on independent and non-identically distributed bivariate Gaussian triangular arrays is derived as the correlation coefficient of ith vector of given nth row is the function of i/n. Furthermore, second-order expansions of joint distributions of maxima and minima are established if the correlation function satisfies some regular conditions. © 2016 Springer Science+Business Media New York

Du Z.,Southwest University | Hu D.,Southwest University
Advanced Materials Research | Year: 2011

TopDisc algorithm, one classic algorithm based on minimum dominating set, puts forward an effective method - approximate topology to set up network. TopDisc algorithm, which only needs local information, is a fully distributed and expandable network-control algorithm. The shortcomings of such algorithm are as follows: the algorithm expense is considerable without taking nodes residual energy into account. After a close analysis of TopDisc algorithm, the author proposes a modified algorithm. The modified algorithm makes good use of the nodes residual energy and reasonably chooses backbone node form heavily energy-loaded ones, which makes the energy evenly consumed, network topology stable and network lifetime endurable. Simulation data indicate that the modified algorithm is very flexible, making the energy evenly consumed, net work topology stable and network lifetime endurable. © (2011) Trans Tech Publications, Switzerland.

Jiang C.D.,Southwest University
Genetika | Year: 2011

Imprinted genes play significant roles in the regulation of fetal growth and development, function of the placenta, and maternal nurturing behaviour in mammals. At present, few imprinted genes have been reported in pigs compared to human and mouse. In order to increase understanding of imprinted genes in swine, a polymorphism-based approach was used to assess the imprinting status of three porcine genes in 12 tissue types, obtained from F1 pigs of reciprocal crosses between Rongchang and Landrace pure breeds. In contrast to human and mouse homologues, porcine PPP1R9A was not imprinted, and was found to be expressed in all tissues examined. The expression of porcine NAP1L5 was detected in pituitary, liver, spleen, lung, kidney, stomach, small intestine, skeletal muscle, fat, ovary, and uterus, but undetectable in heart. Furthermore, porcine NAP1L5 was paternally expressed in the tissues where it's expression was observed. For PEG3, pigs expressed the paternal allele in skeletal muscle, liver, spleen, kidney, and uterus, but biallele in heart, lung, fat, stomach, small intestine, and ovary. Our data indicate that tissue distribution of the three gene differs among mammals, and the imprinting of NAP1L5 and PEG3 is well conserved.

Zhong Z.-Q.,Southwest University | Wu Z.-M.,Southwest University | Wu J.-G.,Southwest University | Xia G.-Q.,Southwest University
IEEE Photonics Journal | Year: 2013

Time-delay (TD) signature performances of polarization-resolved chaos outputs from two mutually coupled vertical-cavity surface-emitting lasers (MC VCSELs) are investigated through detailed simulations by means of self-correlation function (SF) and permutation entropy (PE). The results show that, under suitable coupling strength (η) and frequency detuning (Δ f) between the two MC VCSELs, the TD signatures of two polarization modes from each VCSEL can be suppressed simultaneously. Furthermore, based on the map of TD signature evolution in the parameter space of Δ f and η, the optimal parameter region of TD signature suppression has been determined. © 2009-2012 IEEE.

Zhan C.,Southwest University | Gao K.,Southwest University
IEEE Wireless Communications Letters | Year: 2016

In this letter, we study the problem of distributing data to a group of partially connected cooperative D2D networks using network coding. In such a scenario, the transmission conflicts occur from simultaneous transmissions of multiple devices, where the scheduling decision should be made not only on the encoded packets but also on the set of transmitting devices. We formulate the joint optimization problem over the set of transmitting devices and the packet combinations with a conflict-free graph model, which contains both coding conflict and transmission conflict. We also propose a heuristic solution for this setup by finding the maximum independent set in the conflict-free graph. Simulation results show that our coding scheme significantly reduces the number of transmission slots. © 2012 IEEE.

Wang C.,Southwest University | Yuan R.,Southwest University | Chai Y.,Southwest University | Hu F.,Southwest University
Analytical Methods | Year: 2012

A simple and highly sensitive electrochemical method has been developed for the simultaneous determination of hydroquinone (HQ), catechol (CC), resorcinol (RC) and nitrite (NO 2 -). The electrode in this study exhibited high selectivity, well stability and reproducibility and good compatibility. © 2012 The Royal Society of Chemistry.

Zhang L.,Southwest University | Tian L.,Southwest University | Li M.,Southwest University | He R.,Southwest University | Shen W.,Southwest University
Dalton Transactions | Year: 2014

By imitating FIrpic, seven new platinum(ii) complexes with pic (pic = picolinate) ligand have been designed to be guest materials by means of adding different substituents to functionalized ligands (ppy and fpy, ppy = phenylpyridyl-N,C and fpy = 2-(9′,9′-diethyl-9H-fluorenyl)pyridyl-N, C). In order to reveal their molecular structures, photophysical properties and structure-property relationships with typical host materials, an in-depth theoretical investigation was performed via quantum chemical calculations. The electronic structures and photophysical properties of these complexes were investigated by density functional theory (DFT) and time-dependent density functional theory (TDDFT) using the B3LYP functional with LANL2DZ and 6-31G* basis sets. It turns out that electronic structures and photophysical properties can be tuned by substituent modifications on functionalized ligands. This work highlights that the match between guest materials and host materials in typical OLED structures can be weighed by the energy levels of the HOMO and LUMO and the adiabatic triplet energy of each complex. Also, a combined analysis of electronic structures, host-guest match, reorganization energies (λ) and triplet exciton generation fraction (χT) is helpful in exploring triplet emitters with high phosphorescence efficiency in OLEDs, which is an interesting and creative aspect of this work. Thereinto, λ reveals the capability of carrier transport and the balance between holes and electrons, whilst structural parameters and d-orbital splittings show that those complexes that have strong electron-withdrawing and electron-donating groups are nonemissive. Consequently, complexes 3-7 can be better triplet emitters than FIrpic. Moreover, the emission colors could be predicted by the 0-0 transition energy (E 0-0) instead of the triplet vertical transition energy (E vert). Accordingly, complexes 3, 4 and 6 would be efficient phosphorescent materials with different predicted emission colors. This journal is © the Partner Organisations 2014.

Qin T.T.,Southwest University | Li J.,Southwest University | Luo H.Q.,Southwest University | Li M.,Southwest University | Li N.B.,Southwest University
Corrosion Science | Year: 2011

2,5-Dimercapto-1,3,4-thiadiazole (DMTD) monolayer was self-assembled on the fresh copper surface to form protective monolayer against copper corrosion in acidic solution. Its corrosion inhibition was investigated in 0.5. M HCl by cyclic voltammetry, potentiodynamic polarization and electrochemical impedance spectroscopy methods. The results revealed that the DMTD monolayer inhibited the copper corrosion effectively with the optimum self-assembly time of 10. h and the optimum self-assembly concentration of 7.5. mM. Surface observation was performed using scanning electron microscope, contact angle goniometer and Fourier transform infrared spectrometer. The molecular simulation has been used to simulate the adsorption model of DMTD molecule on Cu(1. 1. 1) surface. © 2010 Elsevier Ltd.

Xie J.,Southwest University | Xie J.,Yuxi Normal University | Huang Y.,Southwest University
Analytical Methods | Year: 2011

In this study, Co 3O 4 nanoparticles were synthesized by a hydrothermal method and characterized using X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FT-IR). The as-prepared Co 3O 4 nanoparticles were used to amplify a weak chemiluminescence (CL) of a luminol-H 2O 2 system. The results of UV-visible absorption and CL spectra showed that the CL luminophor was 3-aminophthalate, indicating that the CL enhancement of the luminol-H 2O 2 system was attributed to the intrinsic catalytic effect of Co 3O 4 nanoparticles acting as the electron transfer accelerators and radical generation proliferators. Based on the H 2O 2 concentration dependence of the catalytic activity of Co 3O 4 nanoparticles, a simple, sensitive and relatively selective CL assay for H 2O 2 was constructed. Under the optimized conditions, a linear relationship was obtained between the CL intensity and H 2O 2 concentration in the range of 1.0 × 10 -8-1.0 × 10 -5 mol L -1 with a detection limit of 1.1 × 10 -9 mol L -1. When combined with the glucose oxidase-catalyzed oxidation reaction, the sensitive detection of glucose could be realized. The linear range for glucose was from 1.0 × 10 -7 to 1.0 × 10 -5 mol L -1 with a detection limit of 8.0 × 10 -8 mol L -1. This proposed method has been successfully applied to the determination of H 2O 2 in rain water and glucose in serum samples. © 2011 The Royal Society of Chemistry.

Qin D.B.,Southwest University
Zhongguo shi yan xue ye xue za zhi / Zhongguo bing li sheng li xue hui = Journal of experimental hematology / Chinese Association of Pathophysiology | Year: 2011

Objective of this study was to investigate the changes of cyclooxygenase-2 expression and mitochondrial membrane potential in apoptotic NB4 cells induced by arsenic trioxide (As(2)O(3)). The morphological changes in apoptosis process of NB4 cells treated by arsenic trioxide were observed under immunofluorescence microscope and DNA electrophoresis method, and the apoptosis rate of NB4 cells and the variations of mitochondrial membrane potential were detected by flow cytometry. Furthermore, the variations of expression level of cyclooxygenase-2 protein were analyzed by using Western blot method. The results indicated that after NB4 cells were treated with 2 μmol/L As(2)O(3) for 48 hours, some variations of NB4 cells were observed, such as pyknosis, chromatin segmentation, even fragmentation. Meanwhile, the typical DNA Ladder phenomenon was observed. The apoptosis rate of NB4 cells treated with 3 μmol/L As(2)O(3) for 48 hours was 33.34%, Furthermore the apoptosis rate of NB4 cells was enhanced along with the increase of concentration of As(2)O(3). After NB4 cells were treated with 0.5, 1, 2, 4 and 8 μmol/L As(2)O(3) for 48 hours, the mitochondrial membrane potential decreased by 12.8%, 21.6%, 66.9%, 83.7% and 83.8% respectively. The Western blot detection results showed that the expression level of cyclooxygenase-2 protein in NB4 cells was lower than that in control cells and decreased along with the rise of As(2)O(3) concentration, then the negative dose-dependent manner was observed between these 2 groups. It is concluded that As(2)O(3) can effectively induce NB4 cell apoptosis, and the dose-dependent manner existed in certain extent of concentrations. The decrease of mitochondrial membrane potential may be related with NB4 cell apoptosis induced by As(2)O(3). Cyclooxygenase-2 participates in the process of NB4 cell apoptosis induced by As(2)O(3).

Fu Y.,Southwest University | Han Q.,Southwest University | Chen Q.,Southwest University | Wang Y.,Southwest University | And 2 more authors.
Chemical Communications | Year: 2012

A new strategy is established for detecting chiral amino acids based on the electron transfer from hemoglobin Fe(ii) to Cu(ii) in copper complexes of the amino acids. The sensor shows a highly selective recognition of arginine enantiomers. © The Royal Society of Chemistry.

Lili W.,Southwest University | Chunlei T.,Southwest University
Acta Mathematica Scientia | Year: 2010

The existence of homoclinic orbits is obtained by the variational approach for a class of second order Hamiltonian systems over(q, ̈) (t) + ∇ V (t, q (t)) = 0, where over(q, ̈) (t) + ∇ V (t, q (t)) = 0 is neither a quadratic form in x nor periodic in t and W(t,x) is superquadratic in x. © 2010 Wuhan Institute of Physics and Mathematics.

Zhan C.,Southwest University | Gao K.,Southwest University
IEEE Wireless Communications Letters | Year: 2016

In this letter, we consider heterogeneous wireless network with storage capable wireless access points, and study the video delivery problem for video files that can be encoded with different layers in various qualities. We introduce a framework for the joint optimization of video file coding, cache content placement, and rate allocation for users with different quality requirements. We formulate the problem as a linear programming using network coding with non-overlapping windows and expanding windows, and the aim is to minimize the traffic load pressure on the base station. Simulation results show that significant caching and coding gains can be achieved with the proposed framework, which translates into a reduction of the extra traffic load on base station. © 2012 IEEE.

Xie W.Y.,Southwest University | Huang W.T.,Southwest University | Li N.B.,Southwest University | Luo H.Q.,Southwest University
Chemical Communications | Year: 2012

In the presence of graphene oxide, upon formation of cytosine-Ag-cytosine the fluorescence wavelength of FAM-labeled DNA exhibited a red shift, and its intensity significantly increased. A novel fluorescent DNA sensor for Ag + and cysteine detection, and a dual-output fluorescent DNA INHIBIT logic gate are designed. © 2012 The Royal Society of Chemistry.

Wei D.-D.,Southwest University | Shao R.,University of Queensland | Shao R.,University of The Sunshine Coast | Yuan M.-L.,Southwest University | And 3 more authors.
PLoS ONE | Year: 2012

Booklice (order Psocoptera) in the genus Liposcelis are major pests to stored grains worldwide and are closely related to parasitic lice (order Phthiraptera). We sequenced the mitochondrial (mt) genome of Liposcelis bostrychophila and found that the typical single mt chromosome of bilateral animals has fragmented into and been replaced by two medium-sized chromosomes in this booklouse; each of these chromosomes has about half of the genes of the typical mt chromosome of bilateral animals. These mt chromosomes are 8,530 bp (mt chromosome I) and 7,933 bp (mt chromosome II) in size. Intriguingly, mt chromosome I is twice as abundant as chromosome II. It appears that the selection pressure for compact mt genomes in bilateral animals favors small mt chromosomes when small mt chromosomes co-exist with the typical large mt chromosomes. Thus, small mt chromosomes may have selective advantages over large mt chromosomes in bilateral animals. Phylogenetic analyses of mt genome sequences of Psocodea (i.e. Psocoptera plus Phthiraptera) indicate that: 1) the order Psocoptera (booklice and barklice) is paraphyletic; and 2) the order Phthiraptera (the parasitic lice) is monophyletic. Within parasitic lice, however, the suborder Ischnocera is paraphyletic; this differs from the traditional view that each suborder of parasitic lice is monophyletic. © 2012 Wei et al.

Wang Y.,Georgia Institute of Technology | Wang Y.,Southwest University | Xie S.,Georgia Institute of Technology | Liu J.,Arizona State University | And 3 more authors.
Nano Letters | Year: 2013

Palladium octahedrons and tetrahedrons enclosed by eight and four {111} facets have been synthesized from cuboctahedral Pd seeds by using Na 2PdCl4 and Pd(acac)2, respectively, as the precursors. Our mechanistic studies indicate that the cuboctahedral seeds were directed to grow into octahedrons, truncated tetrahedrons, and then tetrahedrons when Pd(acac)2 was used as a precursor. In contrast, the same batch of seeds only evolved into octahedrons with increasing sizes when the precursor was switched to Na2PdCl4. The difference in growth pattern could be attributed to the different reduction rates of these two precursors. The fast reduction of Pd(acac)2 led to a quick drop in concentration for the precursor in the very early stage of a synthesis, forcing the growth into a kinetically controlled mode. In comparison, the slow reduction of Na 2PdCl4 could maintain this precursor at a relatively high concentration to ensure thermodynamically controlled growth. This work not only advances our understanding of the growth mechanism of tetrahedrons but also offers a new approach to controlling the shape of metal nanocrystals. © 2013 American Chemical Society.

Alzheimer's disease (AD) is a neurodegenerative disorder in which the death of brain cells leads to memory loss and cognitive decline. To reduce the death rate and improve the biological activity of neurocytes, neurotrophic factors (NTFs) exhibit therapeutic effect on AD. However, therapeutic application of exogenous NTFs in treatment of AD is largely limited due to short half-life, poor stability, etc. Various extracts of traditional Chinese medicine (TCM) have been shown to exhibit therapeutic effects on AD, and some of these effects are associated with regulation on the expression of nerve growth factor, brain-derived neurotrophic factor (BDNF), and glial cell line-derived neurotrophic factor (GDNF) and their associated receptors. This article reviews the progress on promotion of Panax ginseng, Rehmannia glutinosa Libosch., Epimedium, Polygala tenuifolia Willd, and seven other TCMs on secretion of NTFs during AD, with a view to preparation development and clinical application of these TCMs on AD. © 2016 Société Française de Pharmacologie et de Thérapeutique.

Hu L.,Southwest University | Hu L.,CAS Institute of Psychology | Cai M.M.,Southwest University | Xiao P.,Southwest University | And 2 more authors.
Journal of Neuroscience | Year: 2014

Intense radiant heat pulses concomitantly activate Aδ- and C-fiber skin nociceptors, and elicit a typical double sensation: an initial Aδ-related pricking pain is followed by a C-related prolonged burning sensation. It has been repeatedly reported that C-fiber laser-evoked potentials (C-LEPs) become detectable only when the concomitant activation of Aδ-fibers is avoided or reduced. Given that the saliency of the eliciting stimulus is a major determinant of LEPs, one explanation for these observations is that the saliency of the C-input is smaller than that of the preceding Aδ-input. However, even if the saliency of the C-input is reduced because of the preceding Aδ-input, a C-LEP should still be visible even when preceded by an Aδ-LEP response. Here we tested this hypothesis by applying advanced signal processing techniques (peak alignment and time-frequency decomposition) to electroencephalographic data collected in two experiments conducted in 34 and 96 healthy participants. We show that, when using optimal stimulus parameters (delivering >80 stimuli within a small skin territory), C-LEPs can be reliably detected in most participants. Importantly, C-LEPs are observed even when preceded by Aδ-LEPs, both in average waveforms and single trials. By providing quantitative information about several response properties of C-LEPs (latency jitter, stimulus-response and perception-response functions, dependency on stimulus repetitions and stimulated area), these results define optimal parameters to record C-LEPs simply and reliably. These findings have important clinical implications for assessing small-fiber function in neuropathies and neuropathic pain. © 2014 the authors.

Wan X.,Southwest University | Liu Y.,Southwest University | Zhang B.,Southwest University
PLoS ONE | Year: 2012

The oriental fruit fly, Bactrocera dorsalis, was initially recorded in Taiwan Island in 1912, and has dispersed to many areas in the Pacific-Asia region over the last century. The area of origin of the species may be confidently placed in South-East China. However, routes of range expansion to new areas and underlying population processes remain partially unclear, despite having been the subject of several studies. To explore the invasion history of this species, a partition of the cox1 gene of mitochondrial DNA was used to investigate genetic diversity, haplotype phylogeny and demographic history of 35 populations, covering China and South-East Asia and including marginal populations from Pakistan and Hawaii. Based on neighbor-joining tree analysis and the distribution of haplotypes, two main invasion routes are inferred: one from South-East China to Central China, another from South-East China to South-East Asia, with both routes probably coinciding in Central China. Populations in Taiwan Island and Hainan Island might have originated in South-East China. The marginal populations in Pakistan and Hawaii might have undergone founding events or genetic bottlenecks. Possible strategies for the control of this species are proposed based on the invasion history and reconstructed expansion routes. © 2012 Wan et al.

Ding R.,Southwest University | Zheng B.,Southwest University | Wang Y.,Southwest University | Peng Y.,Southwest University
Organic Letters | Year: 2015

A new approach has been developed for an asymmetric sulfur-mediated three-component intermolecular Michael/Mannich domino reaction using chalcones as Michael acceptors. This reaction is catalyzed by chiral quaternary ammonium salts derived from modified quinine and provides facile access to complex sulfur-containing compounds with three contiguous stereogenic centers in yields of up to 93%, with 95:5 dr and 95% ee. These compounds were further elaborated to give the equivalent of a chiral aza-Morita-Baylis-Hillman reaction involving chalcones and azetidines bearing four chiral centers. © 2015 American Chemical Society.

Xu Y.-H.,Southwest University
Communications in Computer and Information Science | Year: 2012

Method of active knowledge push based on capturing intention of collaboration was proposed aiming at the problem of low quality and efficiency in acquiring knowledge for collaborative product design. First of all, distributed model of capturing intention of collaboration was constructed through study on the relations between the capturing intentions of collaboration and the designers' behaviors. Then, the system framework and workflow of knowledge push based on capturing intention of collaboration were constructed. Finally, these methods were applied to engineering practices to validate its technical feasibility and effectiveness. © 2012 Springer-Verlag Berlin Heidelberg.

Ye C.,Southwest University | Zhong X.,Southwest University | Yuan R.,Southwest University | Chai Y.,Southwest University
Sensors and Actuators, B: Chemical | Year: 2014

A highly sensitive electrochemiluminescence (ECL) biosensor for glucose detection has been developed through immobilizing glucose oxidase (GOD) on a glassy carbon electrode (GCE) modified with C60 embedded in tetraoctylammonium bromide (TOAB+) film. C60 is a promising electron transfer mediator between GOD and GCE surface. Meanwhile, C60 has excellent catalytic performance to directly enhance the ECL intensity of luminol. In addition, the introduction of C60 and TOAB+ can immobilize more enzymes effectively onto the electrode so that they can enhance the sensitivity and detection limit of ECL biosensor. Under the optimum condition, the developed glucose biosensor exhibited the linear response range from 500 nM to 13 mM with a detection limit of 166.7 nM (at the signal-to-noise ratio of 3). The biosensor offers an alternative analytical method with excellent properties of high selectivity, long-term stability and outstanding reproducibility. © 2014 Elsevier B.V.

Liu Y.,Southwest University | Zhao Y.,Southwest University | Zhang Y.,Southwest University
Sensors and Actuators, B: Chemical | Year: 2014

High quantum yield carbon quantum dots (CQDs) are successfully synthesized via a simple, low cost, and green hydrothermal method using bamboo leaves as carbon source for the first time. Branched polyethylenimine (BPEI)-capped CQDs (BPEI-CQDs) are prepared by coating the CQDs with BPEI via electrostatic adsorption. The BPEI-CQDs are then employed as fluorescent probes for sensitive and selective Cu2+ detection. Experimental results show that the synthesized CQDs have average size of 3.6 nm in diameter with narrow size distribution. The biomass-based CQDs offer high quantum yield of 7.1%. The BPEI-CQDs-based sensing system renders a simple, reliable and sensitive Cu 2+detection with limit of detection (LOD) as low as 115 nM and a dynamic range from 0.333 to 66.6 μM. In addition, the BPEI-CQDs are successfully used to detect Cu2+ in river water, demonstrating its good selectivity and great potential for analysis of environmental water samples. © 2014 Elsevier B.V.

Yang C.,Southwest University | Wang Q.,Southwest University | Xiang Y.,Southwest University | Yuan R.,Southwest University | Chai Y.,Southwest University
Sensors and Actuators, B: Chemical | Year: 2014

A sensitive and selective electrochemical aptamer sensing platform for adenosine based on target-induced strand release and gold nanoparticle (AuNP) amplification labels is developed. The association of the target adenosine with the corresponding aptamer leads to the release of the thiol c-DNA strands from the aptamer/c-DNA duplexes. The released thiol c-DNA strands are captured on a gold sensing electrode by their complementary sequences through DNA hybridizations. The AuNPs are then attached to the surface-hybridized thiol c-DNA strands via Au-S bond. These AuNPs further adsorb a large number of electroactive species, thionine, on their surfaces, which leads to significantly amplified current response for highly sensitive monitoring of adenosine down to 0.05 nM. Besides, the proposed method shows excellent selectivity toward adenosine against other analogous interference molecules due to the high specificity of the aptamer recognition capability. Moreover, by changing the corresponding specific aptamer recognition strands, the proposed method can offer a more general sensing platform for the detection of low levels of various types of biomolecules (proteins, cells, amino acids, etc.). © 2014 Elsevier B.V.

Liang W.,Southwest University | Liu Z.,Southwest University | Liu S.,Southwest University | Yang J.,Southwest University | And 2 more authors.
Sensors and Actuators, B: Chemical | Year: 2014

A kind of novel Glyp-functionalized-CdTe/CdS Quantum dots (QDs) was successfully synthesized by coating Glyp on the surface of the CdTe/CdS QDs. The fluorescence emission of the modified QDs was enhanced greatly but with a low resonance Rayleigh scattering (RRS). When it interacted with calf thymus DNA (ct-DNA), the fluorescence intensity of the system was obviously quenched and the RRS was enhanced, both in good linear relations. Based on the above, a novel fluorescence biosensor for simple, sensitive and selective detection of ct-DNA was developed. Under the optimized conditions, the linear ranges of the functionalized QDs fluorescence intensity and RRS intensity versus the concentration of ct-DNA were 0.109-70 μg mL-1 and 0.482-90 μg mL-1, respectively. The corresponding detection limits by fluorescence quenching and by RRS enhancing methods were 0.0327 μg mL -1 and 0.146 μg mL-1, respectively. The proposed method was applied to detect ct-DNA in synthetic sample with satisfactory results. © 2014 Elsevier B.V.

Wu X.,Southwest University | Chai Y.,Southwest University | Yuan R.,Southwest University | Zhuo Y.,Southwest University | Chen Y.,Southwest University
Sensors and Actuators, B: Chemical | Year: 2014

The combination of catalyzed hairpin assembly reaction (CHA) and hybridization chain reaction (HCR) is introduced to develop an electrochemical biosensor without the assistance of enzyme for highly sensitive microRNA (miRNA) detection. Firstly, the hairpin-shaped capture probe H1 immobilized on the electrode surface was opened by target. In the presence of another hairpin probe H2, hybridization of H1 to H2 resulted in the release of target from H1-target complex by strand-displacement reaction. The released target further hybridized with the remaining capture probe H1. After the target recycling process, H1-H2 complex was achieved with an exposed stem of H2. Then, the exposed stem of H2 served as initiator to trigger HCR event, yielding long double strands (dsDNA) molecule. Ultimately, numerous methylene blue (MB) as redox probes intercalated into the minor groove of the long dsDNA polymers to achieve amplified electrochemical signal. The proposed miRNA biosensor achieved a linear range from 10 fM to 1 nM with a wide dynamic range of six orders of magnitude. © 2014 Elsevier B.V.

Wang Y.,Georgia Institute of Technology | Wang Y.,Southwest University | Wan D.,Georgia Institute of Technology | Xie S.,Georgia Institute of Technology | And 3 more authors.
ACS Nano | Year: 2013

Silver octahedra with edge lengths controlled in the range of 20-72 nm were synthesized via seed-mediated growth. The key to the success of this synthesis is the use of single-crystal Ag seeds with uniform and precisely controlled sizes to direct the growth and the use of citrate as a selective capping agent for the {111} facets. Our mechanistic studies demonstrated that Ag seeds with both cubic and quasi-spherical shapes could evolve into octahedra. For the first time, we were able to precisely control the edge lengths of Ag octahedra below 100 nm, and the lower limit of size could even be pushed down to 20 nm. Using the as-obtained Ag octahedra as sacrificial templates, Au nanocages with an octahedral shape and precisely tunable optical properties were synthesized through a galvanic replacement reaction. Such hollow nanostructures are promising candidates for a broad range of applications related to optics, catalysis, and biomedicine. © 2013 American Chemical Society.

Liang M.,University College London | Mouraux A.,Catholic University of Louvain | Hu L.,Southwest University | Iannetti G.D.,University College London
Nature Communications | Year: 2013

Whether primary sensory cortices are essentially multisensory or whether they respond to only one sense is an emerging debate in neuroscience. Here we use a multivariate pattern analysis of functional magnetic resonance imaging data in humans to demonstrate that simple and isolated stimuli of one sense elicit distinguishable spatial patterns of neuronal responses, not only in their corresponding primary sensory cortex, but in other primary sensory cortices. These results indicate that primary sensory cortices, traditionally regarded as unisensory, contain unique signatures of other senses and, thereby, prompt a reconsideration of how sensory information is coded in the human brain. © 2013 Macmillan Publishers Limited. All rights reserved.

Wen T.,Southwest University | Li N.B.,Southwest University | Luo H.Q.,Southwest University
Sensors and Actuators, B: Chemical | Year: 2014

A novel sensing system has been designed for the Cu2+ detection based on the quenched fluorescence signal of 6-carboxyfluorescein (FAM)-labeled DNA/polyethyleneimine. The FAM-labeled DNA showed weak fluorescence at the emission wavelength of 530 nm in a pH 4.8 acetic acid-sodium acetate buffer solution. When the polyethyleneimine was introduced to the FAM-labeled DNA solution, the fluorescence signal was greatly amplified. Subsequently, upon the addition of Cu2+, Cu2+ can be captured by the amino groups of the polyethyleneimine to form an absorbent complex, resulting in a strong quenching of the fluorescence of FAM-labeled DNA/polyethyleneimine via a fluorescence resonance energy transfer effect. Herein, we have demonstrated that this facile methodology can offer a rapid, reliable, and selective detection of Cu2+ with a detection limit as low as 20 nM and a linear range of 100-1600 nM. Furthermore, the detection results for Cu2+ in a lake water sample obtained by this sensing system agreed well with that by atomic absorption spectroscopy, suggesting the potential application of this sensing system. © 2013 Elsevier B.V. All rights reserved.

Wei M.,Shandong University | Tian D.,Shandong University | Liu S.,Shandong University | Zheng X.,Shandong University | And 2 more authors.
Sensors and Actuators, B: Chemical | Year: 2014

In the present paper, a β-cyclodextrin (β-CD) functionalized graphene modified carbon paste electrode (CD/GRs/CPE) was prepared and characterized by atomic force microscopy (AFM), Fourier transform infrared (FT-IR) and electrochemical impedance spectroscopy (EIS). The electrochemical behaviors of 2-chlorophenol (2-CP) and 3-chlorophenol (3-CP) on different electrodes were investigated by cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The results demonstrated that the CD/GRs/CPE exhibited remarkable enhancement effects towards these two chlorophenols, especially for 3-CP. Importantly, their oxidation peaks could be well separated by CVs and DPVs. Under the optimized conditions, the oxidation peak currents displayed a good linear relationship to concentration in the ranges from 0.5 to 40 μM for 2-CP and 0.4 to 77 μM for 3-CP, with detection limits of 0.2 and 0.09 μM, respectively. As a practical application, the proposed sensor was applied to quantitatively determine 2-CP and 3-CP in water samples with satisfying results. © 2014 Elsevier B.V.

An C.S.,Southwest University | Saghai B.,CEA Saclay Nuclear Research Center
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2015

Within an extended chiral constituent quark formalism, we investigate contributions from all possible five-quark components in the octet baryons to the pion-baryon (σπB) and strangeness-baryon (σsB) sigma terms: B≡N,Λ,Σ,Ξ. The probabilities of the quark-antiquark components in the ground-state baryon octet wave functions are calculated by taking the baryons to be admixtures of three- and five-quark components, with the relevant transitions handled via the P03 mechanism. Predictions for σπB and σsB obtained by using input parameters taken from the literature are reported. Our results turn out to be, in general, consistent with the findings via lattice QCD and chiral perturbation theory. © 2015 American Physical Society.

Zhang F.X.,Southwest University
Applied Mechanics and Materials | Year: 2014

This paper focus on two level hierarchical scheduling where several real-time applications are scheduled by the fixed priority algorithms. The application with its real-time tasks is bound to a server which can be modeled as a sporadic task with special care for the schedulability analysis. Different scheduling policies and servers can be applied for hierarchical fixed priority systems, this paper gives a closer review of schedulability analysis for applications and tasks when the global and local schedulers of a system are fixed priority. © (2014) Trans Tech Publications, Switzerland.

Han J.,Southwest University | Zhuo Y.,Southwest University | Chai Y.,Southwest University | Xiang Y.,Southwest University | And 3 more authors.
Biosensors and Bioelectronics | Year: 2013

A novel ultrasensitive electrochemical immunoassay for the determination of apurinic/apyrimidinic endonuclease (APE-1) using a three-step signal amplification process was reported in this work. The first-step signal amplification process was based on the labeled biotinylated alkaline phosphatase (bio-AP) on the nickel hexacyanoferrates nanoparticle-decorated Au nanochains (Ni-AuNCs) toward the biocatalysis of ascorbic acid 2-phosphate (AA-P) to in-situ produce ascorbic acid (AA). Then the signal was further amplified by electrochemical oxidation of the in-situ-produced AA because of the catalysis of Ni-AuNCs. Finally, with the nanochain-modified streptavidin (SA), the stoichiometry of bio-AP could be increased through the specific and high affinity interaction of streptavidin-biotin. On the other hand, a kind of organic material (PTC-NH2), owing the amino-functionalized interface and unique electrochemical properties, as matrix for primary antibodies (Ab1) immobilization could lower the background current signal and enhance the amount of immobilized Ab1. With a sandwich-type immunoreaction, the triple signal amplification greatly enhanced the sensitivity for the detection of APE-1. Under optimal conditions, the electrochemical immunosensor exhibited a linear range of 0.01-100pg/mL with an extremely low detection limit of 3.9fg/mL (signal/noise=3). © 2012 Elsevier B.V.

Chen H.,Southwest University | Ping R.-G.,CAS Institute of High Energy Physics
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2015

A large cross section for e+e-→Λc+Λ¯c- pair production near its threshold provides an opportunity to study the charm baryon Λc+/Λ¯c- at a τ-charm factory with e+e- collisions. We call for the determination of the Λc+/Λ¯c- spin using the process e+e-→Λc+Λ¯c-,Λc+→pKS0, and we present a formula and a method to estimate the statistical significance for spin assignment J=12 and J=32. A Monte Carlo study shows that the significance is sensitive to the number of observed events. A few hundred observed signal events will yield the statistical significance larger than five standard deviations. © 2015 American Physical Society.

He X.,Southwest University | Li C.,University of Ballarat | Huang T.,Texas A&M University at Qatar | Li C.,Southwest University
IEEE Transactions on Neural Networks and Learning Systems | Year: 2013

This brief reports a retarded functional differential equation modeling tri-neuron network with time delay. The Bogdanov-Takens (B-T) bifurcation is investigated by using the center manifold reduction and the normal form method. We get the versal unfolding of the norm forms at the B-T singularity and show that the model can exhibit pitchfork, Hopf, homoclinic, and double-limit cycles bifurcations. Some numerical simulations are given to support the analytic results and explore chaotic dynamics. Finally, an algorithm is given to show that chaotic tri-neuron networks can be used for encrypting a color image. © 2012 IEEE.

Dai X.,Southwest University | Gao Z.,Northumbria University
IEEE Transactions on Industrial Informatics | Year: 2013

This review paper is to give a full picture of fault detection and diagnosis (FDD) in complex systems from the perspective of data processing. As a matter of fact, an FDD system is a data-processing system on the basis of information redundancy, in which the data and human's understanding of the data are two fundamental elements. Human's understanding may be an explicit input-output model representing the relationship among the system's variables. It may also be represented as knowledge implicitly (e.g., the connection weights of a neural network). Therefore, FDD is done through some kind of modeling, signal processing, and intelligence computation. In this paper, a variety of FDD techniques are reviewed within the unified data-processing framework to give a full picture of FDD and achieve a new level of understanding. According to the types of data and how the data are processed, the FDD methods are classified into three categories: model-based online data-driven methods, signal-based methods, and knowledge-based history data-driven methods. An outlook to the possible evolution of FDD in industrial automation, including the hybrid FDD and the emerging networked FDD, are also presented to reveal the future development direction in this field. © 2013 IEEE.

Zhang Y.,Southwest University | Zhang Z.,Southwest University | Zhang Z.,Deakin University | Deng Y.,Southwest University | And 2 more authors.
Applied Soft Computing Journal | Year: 2013

By considering the uncertainty that exists in the edge weights of the network, fuzzy shortest path problems, as one of the derivative problems of shortest path problems, emerge from various practical applications in different areas. A path finding model, inspired by an amoeboid organism, Physarum polycephalum, has been shown as an effective approach for deterministic shortest path problems. In this paper, a biologically inspired algorithm called Fuzzy Physarum Algorithm (FPA) is proposed for fuzzy shortest path problems. FPA is developed based on the path finding model, while utilizing fuzzy arithmetic and fuzzy distance to deal with fuzzy issues. As a result, FPA can represent and handle the fuzzy shortest path problem flexibly and effectively. Distinct from many existing methods, no order relation has been assumed in the proposed FPA. Several examples, including a tourist problem, are given to illustrate the effectiveness and flexibility of the proposed method and the results are compared with existing methods.© 2013 Elsevier B.V. All rights reserved.

Yu J.,CAS Institute of Psychology | Yu J.,University of Chinese Academy of Sciences | Yu J.,Southwest University | Li J.,CAS Institute of Psychology | And 2 more authors.
BMC Psychiatry | Year: 2012

Background: A cross-sectional validation study was conducted in several urban and rural communities in Beijing, China, to evaluate the effectiveness of the Beijing version of the Montreal Cognitive Assessment (MoCA-BJ) as a screening tool to detect mild cognitive impairment (MCI) among Chinese older adults.Methods: The MoCA-BJ and the Mini-Mental State Examination (MMSE) were administered to 1001 Chinese elderly community dwellers recruited from three different regions (i.e., newly developed, old down-town, and rural areas) in Beijing. Twenty-one of these participants were diagnosed by experienced psychiatrists as having dementia, 115 participants were diagnosed as MCI, and 865 participants were considered to be cognitively normal. To analyze the effectiveness of the MoCA-BJ, we examined its psychometric properties, conducted item analyses, evaluated the sensitivity and specificity of the scale, and compared the scale with the MMSE. Demographic and regional differences among our subjects were also taken into consideration.Results: Under the recommended cut-off score of 26, the MoCA-BJ demonstrated an excellent sensitivity of 90.4%, and a fair specificity (31.3%). The MoCA-BJ showed optimal sensitivity (68.7%) and specificity (63.9%) when the cut-off score was lowered to 22. Among all the seven cognitive sub-domains, delayed recall was shown to be the best index to differentiate MCI from the normal controls. Regional differences disappeared when the confounding demographic variables (i.e., age and education) were controlled. Item analysis showed that the internal consistency was relatively low in both naming and sentence repetition tasks, and the diagnostic accuracy was similar between the MoCA-BJ and the MMSE.Conclusions: In general, the MoCA-BJ is an acceptable tool for MCI screening in both urban and rural regions of Beijing. However, presumably due to the linguistic and cultural differences between the original English version and the Chinese version of the scale, and the lower education level of Chinese older adults, the MoCA-BJ is not much better than the MMSE in detecting MCI, at least for this study sample. Further modifications to several test items of the MoCA-BJ are recommended in order to improve the applicability and effectiveness of the MoCA-BJ in MCI screening among the Chinese population. © 2012 Yu et al.; licensee BioMed Central Ltd.

Ybarra O.,University of Michigan | Ybarra O.,Southwest University | Winkielman P.,University of California at San Diego
Frontiers in Human Neuroscience | Year: 2012

A successful social interaction requires fast, on-line, and active construction of an ever-changing mental-model of another's person beliefs, expectations, emotions, and desires. It also requires the ability to inhibit inappropriate behaviors, problem-solve, take-turns, and pursue goals in a distraction-rich environment. All these tasks rely on executive functions (EF)-working memory, attention/cognitive control, and inhibition. Executive functioning has long been viewed as relatively static. However, starting with recent reports of successful cognitive interventions, this view is changing and now EFs are seen as much more open to both short and long term "training," "warm-up," and "exhaustion" effects. Some of the most intriguing evidence comes from research showing how social interaction enhances performance on standard EF tests. Interestingly, the latest research indicates these EF benefits are selectively conferred by certain on-line, dynamic social interactions, which require participants to engage with another person and actively construct the model of their mind. We review this literature and highlight its connection with evolutionary and cultural theories emphasizing links between intelligence and social life. © 2012 Ybarra.

Yuan W.,Southwest University | Yuan W.,Nanyang Technological University | Lu Z.,Southwest University | Lu Z.,Nanyang Technological University | And 3 more authors.
Advanced Functional Materials | Year: 2012

A unique delivery system to reversibly and controllably load and release proteins under physiological conditions is desirable for protein therapeutics. We fabricate an ultrafast exponentially growing nanoporous multilayer structure comprised of two weak polyelectrolytes, poly(ethyleneimine) and alginate with thickness and chemical composition controlled by the assembly pH. For the first time, the assembled multilayered structure demonstrates stimuli-free reversible protein loading and release capability at physiological conditions by a synthetic material. The protein loading and release time can also be controlled by the assembled bilayer number. The highest loading capacity for the target protein and longest release time of proteins for layer-by-layer films reported to date have been achieved with a 15-bilayered film fabricated in this work. The prominent properties of the assembled film provide great potential for various biomedical applications, especially as a delivery system for protein therapeutics. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Zhang X.,Southwest University | He S.,Southwest University | Chen Z.,Southwest University | Huang Y.,Southwest University
Journal of Agricultural and Food Chemistry | Year: 2013

Recently, the intrinsic enzyme-like activity of nanoparticles (NPs) has become a growing area of interest. However, the analytical applications of the NP-based enzyme mimetic are mainly concentrated on their peroxidase-like activity; no attempts have been made to investigate the analytical applications based on the oxidase mimic activities of NPs. For the first time, we report that CoFe2O4 NPs were found to possess intrinsic oxidase-like activity and could catalyze luminol oxidation by dissolved oxygen to produce intensified chemiluminescence (CL). The effect of sulfite on CoFe 2O4 NP oxidase mimic-mediated CL of aqueous luminol was investigated. It is very interesting that when adding sulfite to the luminol-CoFe2O4 system, the role of sulfite in the luminol-CoFe2O4 NP-sulfite system depends on its concentration. At a relatively low concentration level, sulfite presents an inhibition effect on the luminol-CoFe2O4 NP system. However, it does have an enhancement effect at a higher concentration level. Investigations on the effect of the solution pH and luminol and CoFe 2O4 NP concentrations on the kinetic characteristics of the studied CL system in the presence of trace sulfite suggested that the enhancement and inhibition of the luminol-CoFe2O4 NP-sulfite CL system also depended on the solution pH. It seems that the concentrations of luminol and CoFe2O4 NPs did not influence the CL pathway. The possible mechanism of the luminol-CoFe 2O4 NP-sulfite CL system was also discussed. On this basis, a flow injection chemiluminescence method was established for the determination of trace sulfite in this study. Under the optimal conditions, the proposed system could respond down to 2.0 × 10-8 M sulfite. The method has been applied to the determination of trace sulfite in white wine samples with satisfactory results. The results given by the proposed method are in good agreement with those given by the standard titration method. © 2013 American Chemical Society.

Wang S.,Southwest University | Wei M.,Southwest University | Huang Y.,Southwest University
Journal of Agricultural and Food Chemistry | Year: 2013

A new biosorbent material from eggshell membrane was synthesized through thiol functionalization, which is based on the reduction of disulfide bonds in eggshell membrane by ammonium thioglycolate. The thiol-functionalized eggshell membrane was characterized, and its application as an adsorbent for removal of Cr(VI), Hg(II), Cu(II), Pb(II), Cd(II), and Ag(I) from aqueous water has been investigated. The experimental results revealed that the adsorption abilities of the thiol-functionalized eggshell membrane toward Cr(VI), Hg(II), Cu(II), Pb(II), Cd(II), and Ag(I) improved 1.6-, 5.5-, 7.7-, 12.4-, 12.7-, and 21.1-fold, respectively, compared with that of the eggshell membrane control. The adsorption mechanism and adsorption performance, including the adsorption capacity and the kinetics of the thiol-functionalized eggshell membrane for the target heavy metals, were investigated. The effects of solution pH, coexisting substances, and natural water matrices were studied. The thiol-functionalized eggshell membrane can be used as column packing to fabricate a column for real wastewater purification. © 2013 American Chemical Society.

Yang Z.,Southwest University | Jackson T.,Southwest University | Chen H.,Southwest University
Journal of Pain | Year: 2013

Abstract In this study, effects of chronic pain and pain-related fear on orienting and maintenance of attention toward pain stimuli were evaluated by tracking eye movements within a dot-probe paradigm. The sample comprised matched chronic pain (n = 24) and pain-free (n = 24) groups, each of which included lower and higher fear of pain subgroups. Participants completed a dot-probe task wherein eye movements were assessed during the presentation of sensory pain-neutral, health catastrophe-neutral, and neutral-neutral word pairs. Higher fear of pain levels were associated with biases in 1) directing initial gaze toward health catastrophe words and, among participants with chronic pain, 2) subsequent avoidance of threat as reflected by shorter first fixation durations on health catastrophe words compared to pain-free cohorts. As stimulus word pairs persisted for 2,000 ms, no group differences were observed for overall gaze durations or reaction times to probes that followed. In sum, this research identified specific biases in visual attention related to fear of pain and chronic pain during early stages of information processing that were not evident on the basis of later behavior responses to probes. Perspective Effects of chronic pain and fear of pain on attention were examined by tracking eye movements within a dot-probe paradigm. Heightened fear of pain corresponded to biases in initial gaze toward health catastrophe words and, among participants with chronic pain, subsequent gaze shifts away from these words. No reaction time differences emerged. © 2013 by the American Pain Society.

Guo S.F.,Southwest University | Qiu J.L.,Southwest University | Yu P.,Chongqing Normal University | Xie S.H.,Shenzhen University | Chen W.,Yale University
Applied Physics Letters | Year: 2014

Fe-based bulk metallic glasses (BMGs) typically exhibit ultrahigh strength but a poor ductility. Here, an Fe62Ni18P13C7 BMG with a super large plasticity of above 50% is reported. Such a discovery is guided by understanding a composition-strength-ductility map, in which most of Fe-based BMGs are classified into three types: FeC(B)-based, FeB-based, and FeP(C)-based. We demonstrate that the mechanical properties of the different types of BMGs are linked with their different physical properties. Among the three types of BMGs, the FeP(C)-based BMGs often possess a lower glass transition temperature, a lower shear modulus, and a higher Poisson's ratio, resulting in a lower shear flow barrier and a higher plasticity. Our findings provide a guideline in understanding the mechanical behavior of Fe-based BMGs. © 2014 AIP Publishing LLC.

Wang Q.,Southwest University | Song Y.,Southwest University | Chai Y.,Southwest University | Pan G.,Southwest University | And 3 more authors.
Biosensors and Bioelectronics | Year: 2014

In this work, an ultrasensitive electrochemical immunosensor for detecting the Pebrine disease related spore wall protein of Nosema bombycis (SWP N.b) was fabricated based on the amplification of hemin/G-quadruplex functionalized Pt at Pd nanowires (Pt at PdNWs). The synthesized Pt at PdNWs possessed large surface area, which could effectively improve the immobilization amount of hemin/G-quadruplex DNAzyme concatamers produced via hybridization chain reaction (HCR). In the presence of SWP N.b, the hemin/G-quadruplex labeled Pt at PdNWs bioconjugations was captured on electrode surface and thus obtained electrochemical signal. After the addition of NADH into the electrolytic cell, hemin/G-quadruplex firstly acted as an NADH oxidase to locally produce H2O2 in the presence of dissolved O2. Then, the generated H2O2 would be quickly reduced via hemin/G-quadruplex as a horseradish peroxidase mimicking (HRP-mimicking) DNAzyme, which finally promoted the self-redox reaction of hemin/G-quadruplex and a greatly enhanced electrochemical signal was obtained. Furthermore, Pt at PdNWs with excellent electrocatalytic performance could also amplify electrochemical signal. With these amplification factors, the electrochemical immunosensor exhibited a wide linear range from 0.001ngmL-1 to 100ngmL-1 with a detection limit (LOD) of 0.24pgmL-1, providing a new promise for the diagnosis of Pebrine disease. © 2014 Elsevier B.V.

Yang X.,Southwest University | Luo Y.,Southwest University | Zhu S.,Southwest University | Feng Y.,Southwest University | And 2 more authors.
Biosensors and Bioelectronics | Year: 2014

Herein, a novel strategy for synthesizing fluorescent carbon nanoparticles (CPs) with a quantum yield of approximately 7.1% has been well established by mixing l-cysteine, diphosphorus pentoxide and water. Compared with other current protocols, the method described here displayed various advantages including friendly manipulations, low cost, and rapid reactions. Subsequently, we applied the CPs prepared here for detections of tetracyclines (TCs). Briefly, the fluorescence intensity of CPs was quenched once TCs were introduced. Based on this phenomenon, TCs were analyzed respectively accompanyed with satisfactory detection limits and linear ranges. Significantly, the practicability of this sensing method was further validated by assaying TC in human urine samples and pharmaceutical preparations, confirming its potential to broaden avenues for detecting TCs. Additionally, the CPs could serve as fluorescent powder and ink followed by a simple post-treatment, suggesting their promising applications. © 2014 Elsevier B.V.

Xu Y.,Southwest University | Zhou W.,Southwest University | Zhou M.,University of Washington | Xiang Y.,Southwest University | And 2 more authors.
Biosensors and Bioelectronics | Year: 2014

Based on a new signal amplification strategy by the toehold strand displacement-driven cyclic assembly of G-quadruplex DNA, the development of an enzyme-free and non-label aptamer sensing approach for sensitive fluorescent detection of thrombin is described. The target thrombin associates with the corresponding aptamer of the partial dsDNA probes and liberates single stranded initiation sequences, which trigger the toehold strand displacement assembly of two G-quadruplex containing hairpin DNAs. This toehold strand displacement reaction leads to the cyclic reuse of the initiation sequences and the production of DNA assemblies with numerous G-quadruplex structures. The fluorescent dye, N-Methyl mesoporphyrin IX, binds to these G-quadruplex structures and generates significantly amplified fluorescent signals to achieve highly sensitive detection of thrombin down to 5. pM. Besides, this method shows high selectivity towards the target thrombin against other control proteins. The developed thrombin sensing method herein avoids the modification of the probes and the involvement of any enzyme or nanomaterial labels for signal amplification. With the successful demonstration for thrombin detection, our approach can be easily adopted to monitor other target molecules in a simple, low-cost, sensitive and selective way by choosing appropriate aptamer/ligand pairs. © 2014 Elsevier B.V.

Cao H.,Southwest University | Chen Z.,Southwest University | Zheng H.,Southwest University | Huang Y.,Southwest University
Biosensors and Bioelectronics | Year: 2014

A simple, one-step facile route for preparation of water soluble and fluorescent Cu nanoclusters (NCs) stabilized by tannic acid (TA) is described. The as-prepared TA capped Cu NCs (TA-Cu NCs) are characterized by UV-vis spectroscopy, Fourier transform infrared (FT-IR) spectroscopy, luminescence, transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). The TA-Cu NCs show luminescence properties having excitation and emission maxima at 360nm and 430nm, respectively, with a quantum yield of about 14%. The TA-Cu NCs are very stable even in 0.3M NaCl, and their luminescent properties show pH independent. The fluorescence (FL) of Cu NCs is strongly quenched by Fe3+ through an electron transfer mechanism, but not by other metal ions. Furthermore, the FL of the TA-Cu NCs shows no changes with the addition of Fe2+ or H2O2 individually. On this basis, a facile chemosensor was developed for rapid, reliable, sensitive, and selective sensing of Fe3+ ions with detection limit as low as 10nM and a dynamic range from 10nM to 10μM. The proposed sensor was successfully used for the determination of iron contents in serum samples. Importantly, the Cu NCs-based FL probe showed long-term stability, good biocompatibility and very low cytotoxicity. It was successfully used for imaging ferric ions in living cells, suggesting the potential application of Cu NCs fluorescent probe in clinical analysis and cell imaging. © 2014 Elsevier B.V.

Zhou Z.,CAS Beijing National Laboratory for Molecular | Huang H.,CAS Beijing National Laboratory for Molecular | Chen Y.,CAS Beijing National Laboratory for Molecular | Liu F.,CAS Beijing National Laboratory for Molecular | And 2 more authors.
Biosensors and Bioelectronics | Year: 2014

A new metal-enhanced fluorescence (MEF) based platform was developed on the basis of distance-dependent fluorescence quenching-enhancement effect, which combined the easiness of Ag-thiol chemistry with the MEF property of noble-metal structures as well as the molecular beacon design. For the given sized AgNPs, the fluorescence enhancement factor was found to increase with a d6 dependency in agreement with fluorescence resonance energy transfer mechanism at shorter distance and decrease with a d-3 dependency in agreement with plasmonic enhancement mechanism at longer distance between the fluorophore and the AgNP surface. As a proof of concept, the platform was demonstrated by a sensitive detection of mercuric ions, using thymine-containing molecular beacon to tune silver nanoparticle (AgNP)-enhanced fluorescence. Mercuric ions were detected via formation of a thymine-mercuric-thymine structure to open the hairpin, facilitating fluorescence recovery and AgNP enhancement to yield a limit of detection of 1nM, which is well below the U.S. Environmental Protection Agency regulation of the Maximum Contaminant Level Goal (10nM) in drinking water. Since the AgNP functioned as not only a quencher to reduce the reagent blank signal but also an enhancement substrate to increase fluorescence of the open hairpin when target mercuric ions were present, the quenching-enhancement strategy can greatly improve the detection sensitivity and can in principle be a universal approach for various targets when combined with molecular beacon design. © 2013 Elsevier B.V.

Zhuo Y.,Southwest University | Gui G.,Southwest University | Gui G.,Bijie University | Chai Y.,Southwest University | And 3 more authors.
Biosensors and Bioelectronics | Year: 2014

In this work, a novel polyamidoamine (PAMAM) dendrimer-l-cysteine-hollow gold nanospheres nanocomposite was fabricated and used as the promoter for the peroxydisulfate/O2 ECL system to detect the concentration of the tumor marker carcinoembryonic antigen (CEA). Herein, the carboxyl-terminated PAMAM dendrimers were decorated with l-cysteine (l-Cys) by EDC/NHS coupling chemistry. Then, the hollow gold nanospheres (HGNPs) were employed as effective nano-carriers for the assembly of PAMAM-l-Cys via thiols-Au bonding, which was used for further loading of detection antibody (Ab2) to form the PAMAM-l-Cys-HGNPs-Ab2 bioconjugates. In the presence of target CEA, the sandwiched immuno-structure can be formed between the capture anti-CEA antibodies (Ab1), which self-assembled on deposited gold modified electrode, and the Ab2 on the PAMAM-l-Cys-HGNPs, thereby resulting in a proportional increase in ECL response, due to the significant enhancement of PAMAM-l-Cys-HGNPs toward peroxydisulfate/O2 ECL system. As a result, a sandwich ECL assay for CEA detection was developed with excellent sensitivity of a large concentration variation from 20fg/mL to 1.0ng/mL and a detection limit of 6.7fgmL-1. © 2013 Elsevier B.V.

Zhou W.,Southwest University | Su J.,Southwest University | Chai Y.,Southwest University | Yuan R.,Southwest University | Xiang Y.,Southwest University
Biosensors and Bioelectronics | Year: 2014

Naked eye-based detection has received increasing research interest due to the simplicity nature of this type of assay. However, improving the sensitivity of the naked eye detection method for the monitoring of trace amount of target molecules remains a major challenge. Herein, we describe a biobarcode and an enzyme-assisted DNA recycling hybrid amplification strategy for naked eye detection of sub-picomolar carcinoembryonic antigen (CEA), a cancer biomarker. The presence of CEA and the corresponding antibodies results in the formation of immunocomplexes and the capture of the biobarcodes in a microplate. The massive barcode DNAs released from the biobarcodes hybridize with the G-quadruplex inactive hairpin DNA probes and form catalytic nicking sites for N.BstNBI endonuclease, which cleaves the barcode DNA/hairpin partial dsDNA, releases the G-quadruplex active sequences and recycles the barcode DNA. Due to the barcode DNA recycling process, numerous G-quadruplex active sequences are generated and associate with hemin to form peroxidase mimicking enzymes, which convert colorless ABTS2- to green color intensified ABTS•- to achieve naked eye detection of CEA down to 0.025ngmL-1 (0.14pM). The naked eye detection strategy reported herein can be applied also to complicated serum sample matrix, making this approach hold great promise for point-of-care diagnostic applications. © 2013 Elsevier B.V.

Zhang P.,Southwest University | Lan J.,Southwest University | Wang Y.,Southwest University | Xiong Z.H.,Southwest University | Huang C.Z.,Southwest University
Biomaterials | Year: 2015

Silk is an excellent natural material and has been used for a variety of applications. Modification of the pristine silk is usually needed depending on the intended purpose. The technical treatments involved in the modification not only should be easy, rapid, environmentally friendly, and cheap but should also retain the features of the pristine silk. Herein, we demonstrate that luminescent silk and fabric can be produced through nanotechnology. The surface of the natural silk fiber is chemically coated with luminescent gold nanoclusters (AuNCs) composed of tens to hundreds of Au atoms through a redox reaction between the protein-based silk and an Au salt precursor. The luminescent silk coated with AuNCs (called golden silk) possesses good optical properties, including a relatively long wavelength emission, high quantum yields, a long fluorescent lifetime, and photostability. Moreover, golden silk prepared this way has better mechanical properties than pristine silk, is better able to inhibit UV, and has lower toxicity invitro. This work not only provides an effective strategy for in situ preparation of luminescent metal nanoclusters on a solid substrate but also paves the way for large-scale and industrialized production of novel silk-based materials or fabrics through nanotechnology. © 2014 Elsevier Ltd.

Xie S.,Southwest University | Chai Y.,Southwest University | Yuan Y.,Southwest University | Bai L.,Southwest University | Yuan R.,Southwest University
Biosensors and Bioelectronics | Year: 2014

Loop-mediated isothermal amplification (LAMP) is an outstanding DNA amplification procedure, in which the reaction can accumulate 109 copies from less than 10 copies of input template within an hour. While the amplification reaction is extremely powerful, the quantitative detection of LAMP products is still analytically difficult. Besides, the type of targets that LAMP can detect is also less, which to some extent limited the application of LAMP. In this study, we are reporting for the first time an efficient and accurate detection system which employs the integration of LAMP, aptamer and the electrochemical method for the sensitive detection of Ochratoxin A (OTA). Aptamers were designed as the forward outer primer to trigger the LAMP reaction, and then the LAMP amplification products were combined with a redox active molecule methylene blue (MB) and analyzed by an electrode using differential pulse voltammograms (DPV). As the reaction progresses, the MB intercalated into double-stranded regions of LAMP amplicons reduces the free MB concentration. Hence, the peak current of reaction mixture decreased with the amplification because of the slow diffusion of MB-amplified DNA complex to the electrode surface. The peak height of the current was related to the input amount of the aptamers, providing a ready means to detection the concentration of OTA. With such design, the proposed assay showed a good linear relationship within the range of 0.001-50nM with a detection limit of 0.3pM (defined as S/N=3) for OTA. © 2014.

Zhou W.,Southwest University | Gong X.,Southwest University | Xiang Y.,Southwest University | Yuan R.,Southwest University | Chai Y.,Southwest University
Biosensors and Bioelectronics | Year: 2014

Visual detections have attracted great research attentions recently due to their convenient monitoring of the target analytes without using any advanced instruments. However, achieving visual detection of trace amounts of biomolecules with PCR-like sensitivity remains a major challenge. In current work, we describe a new quadratic signal amplification strategy for sensitive visual detection of HIV DNA biomarkers based on exonuclease III (Exo III)-assisted DNA recycling amplification and DNAzymes. The presence of the target HIV DNA leads to two independent and simultaneous DNA recycling processes to achieve quadratic signal amplification with the assistance of Exo III. This quadratic signal amplification results in catalytic cleavage of the G-quadruplex sequence-locked hairpin probes to release numerous active G-quadruplex sequences, which further associate with hemin to form DNAzymes and cause significantly intensified color change for sensitive and visual detection of HIV DNA down to 2.5. pM. The proposed visual detection method employs un-modified hairpin DNA as probes, avoids using any complex and expensive instruments for signal transduction and is essentially simple. This method also shows single-base mismatch discrimination capability as well. All these features make our developed DNA detection method holds great potential for visual monitoring of various DNA biomarkers at ultralow levels with careful and proper probe designs. © 2013 Elsevier B.V.

Wang Q.,Southwest University | Yang C.,Southwest University | Xiang Y.,Southwest University | Yuan R.,Southwest University | Chai Y.,Southwest University
Biosensors and Bioelectronics | Year: 2014

Based on nicking endonuclease (NEase)-assisted target recycling and rolling circle amplification (RCA) for in situ generation of numerous G-quadruplex/hemin complexes, we developed a new, dual amplified and ultrasensitive electrochemical biosensor for mutant human p53 gene. The target mutant DNA hybridizes with the loop portion of a dithiol-modified hairpin probe (HP) self-assembled on a gold sensing electrode and forms nicking site for the NEase, which cleaves the HP and releases the target DNA. The released target DNA again hybridizes with the intact HP and initiates the DNA recycling process with the assistance of the NEase, leading to the cleavage of a large number of the HPs and the generation of numerous primers for RCA. With rationally designed, G-quadruplex complementary sequence-encoded RCA circular template, subsequent RCA results in the formation of long DNA sequences with massive tandem-repeat G-quadruplex sequences, which further associate with hemin and generate significantly amplified current response for highly sensitive DNA detection down to 0.25. fM. The developed method also exhibits high specificity for the target DNA against single-base mismatched sequence. With the ultrahigh sensitivity feature induced by the dual signal amplification, the proposed method can thus offer new opportunities for the detection of trace amounts of DNA. © 2013 Elsevier B.V.

He Y.-H.,Southwest University | Li H.-H.,Southwest University | Chen Y.-L.,Southwest University | Xue Y.,Southwest University | And 2 more authors.
Advanced Synthesis and Catalysis | Year: 2012

Chymopapain, a cysteine proteinase isolated from the latex of the unripe fruits of Carica papaya, displays a promiscuous activity to catalyze the direct asymmetric aldol reactions of aromatic and heteroaromatic aldehydes with cyclic and acyclic ketones in acetonitrile in the presence of a phosphate buffer. The excellent enantioselectivities of up to 96% ee and high diastereoselectivities of up to >99:1 (anti/syn) were achieved. The novel catalytic promiscuity of chymopapain widens the applicability of this biocatalyst in organic synthesis. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Li L.,Southwest University
Yi chuan = Hereditas / Zhongguo yi chuan xue hui bian ji | Year: 2013

Zebrafish (Danio rerio) is becoming more and more popular as a model organism to study vertebrate organogenesis and regeneration, taking the advantage of its extra-uterine development, transparency, strong regeneration ability and suitability for the large scale genetic screen. In the past decades, a series of useful methods have been established in zebrafish, which allows studies of important questions in developmental biology including cell fate determination, differentiation, morphogenesis, and regeneration after tissue/organ injury. Recently, using large scale mutagenesis screen and improved live imaging techniques, many questions that had not been well understood in mice have been successfully investigated in zebrafish. Therefore, we are confident that the zebrafish model system will further help decipher the cellular and molecular mechanisms of organogenesis and regeneration in the future, providing valuable references for the treatment of related clinical diseases. This review just summarized the progress in the studies of the important organs development using zebrafish, such as central nervous system(CNS), liver and pancreas, blood and vessel, recently. Meanwhile, the updated informations about the regeneration of tail fin, heart, liver, retina and so on in zebrafish were also included in this paper.

Zhang H.-Z.,Southwest University | Damu G.L.V.,Southwest University | Cai G.-X.,Southwest University | Zhou C.-H.,Southwest University
European Journal of Medicinal Chemistry | Year: 2013

A novel series of benzimidazole type of Fluconazole analogues were synthesized and characterized by 1H NMR, 13C NMR, IR, MS and HRMS spectra. All the new compounds were screened for their antimicrobial activities in vitro by two-fold serial dilution technique. The bioactive evaluation showed that 3,5-bis(trifluoromethyl)phenyl benzimidazoles gave comparable or even stronger antibacterial and antifungal efficiency in comparison with reference drugs Chloromycin, Norfloxacin and Fluconazole. The combination of 2,4-difluorobenzyl benzimidazole derivative 5m and its hydrochloride 7 respectively with antibacterial Chloromycin, Norfloxacin or antifungal Fluconazole showed better antimicrobial efficiency with less dosage and broader antimicrobial spectrum than the separated use of them alone. Notably, these combined systems were more sensitive to Fluconazole-insensitive Aspergillus flavus and methicillin-resistant MRSA. © 2013 Elsevier Masson SAS. All rights reserved.

Qi S.,Southwest University | Qi S.,Liaoning Normal University | Zeng Q.,Southwest University | Ding C.,Southwest University | And 3 more authors.
Brain Research | Year: 2013

Event-related potentials (ERPs) were used to investigate whether a physically non-salient and task-irrelevant stimulus feature previously associated with reward can capture attention. In the training phase, participants implicitly associated a certain color with reward. In the subsequent test phase, participants searched for a uniquely shaped singleton among non-target shapes, with color completely irrelevant to the current task demand. Response time was delayed on trials wherein the target was simultaneously presented with an associated distracter, compared with trials without one. In ERPs, a lateralized reward-associated distracter elicited an N2pc component when a concurrent target was presented on the vertical meridian. The control experiment discounted the possibility that this N2pc was caused by familiarity of the reward-associated distracter. Presenting both the target and reward-associated distracter on the opposite side elicited N2pc, with the reward-associated distracter-elicited N2pc preceding the target-elicited N2pc, albeit only in trials with slow responses. These results show that the participants shifted their attention to the target only after noticing the task-irrelevant reward-associated distracter in slow trials. Therefore, task-irrelevant reward-driven salience can capture attention. Distracter positivity was observed in fast distracter-present trials presenting both a lateral distracter and a midline target. Thus, the reward-associated distracter should be actively suppressed to efficiently select the task-relevant target. Lastly, the distracter-elicited N2pc was negatively correlated with individual differences in reward drive score. This correlation may provide insight into reward sensitivity problems. © 2013 Elsevier B.V.

Wu S.,Pennsylvania State University | Wu S.,Southwest University | Peiffer M.,Pennsylvania State University | Luthe D.S.,Pennsylvania State University | Felton G.W.,Pennsylvania State University
PLoS ONE | Year: 2012

The oral secretions of herbivores are important recognition cues that can be used by plants to mediate induced defenses. In this study, a degradation of adenosine-5′-triphosphate (ATP) in tomato leaves was detected after treatment with Helicoverpa zea saliva. Correspondingly, a high level of ATPase activity in saliva was detected and three ATP hydrolyzing enzymes: apyrase, ATP synthase and ATPase 13A1 were identified in salivary glands. To determine the functions of these proteins in mediating defenses, they were cloned from H. zea and expressed in Escherichia coli. By applying the purified expressed apyrase, ATP synthase or ATPase 13A1 to wounded tomato leaves, it was determined that these ATP hydrolyzing enzymes suppressed the defensive genes regulated by the jasmonic acid and ethylene pathways in tomato plant. Suppression of glandular trichome production was also observed after treatment. Blood-feeding arthropods employ 5′-nucleotidase family of apyrases to circumvent host responses and the H. zea apyrase, is also a member of this family. The comparatively high degree of sequence similarity of the H. zea salivary apyrase with mosquito apyrases suggests a broader evolutionary role for salivary apyrases than previously envisioned. © 2012 Wu et al.

Pang H.,Nanyang Technological University | Yang H.,Nanyang Technological University | Guo C.X.,Nanyang Technological University | Guo C.X.,Southwest University | And 3 more authors.
Chemical Communications | Year: 2012

Submicrometer-sized hollow TiO2 spheres are directly self-assembled from TiO2 nanoparticles without using any template or surfactant as a scattering layer for dye-sensitized solar cells, showing good visible light scattering match to significantly improve the photoconversion efficiency. © 2012 The Royal Society of Chemistry.

Zou J.,Southwest University | Zou J.,Chongqing University | Gao J.,Chongqing University | Xie F.,Chongqing University
Journal of Alloys and Compounds | Year: 2010

An amorphous free-impurity TiO2 sol was synthesized only by means of ultrasonic dispersing of Ti(OH)4 precipitation without any peptizing agents. Anatase sol was obtained by hydrothermally treating the amorphous TiO2 sol. Photocatalytic tests showed that the amorphous sol exhibited higher photocatalytic activity for the photodegradation of methylene blue (MB) under visible light and UV irradiation than anatase sol and P25 TiO2. The photocatalysts were characterized by UV-visible spectroscopy, Raman spectrometer, photoluminescence (PL), FTIR, TEM, XRD, and XPS. The results showed the peroxide titanium complexes were formed on TiO2 sol particles sensitized with H2O2. More peroxide complexes and stronger vis absorption were observed for the amorphous TiO2 sol sensitized with H2O2.The sensitization of H2O2 would completely quench PL of the amorphous sol, but little impact on the anatase sol. The surface structure with fewer physisorbed water molecules facilitated the sensitization of H2O2 to the amorphous TiO2 sol particles, which resulted in the generation of more OH radicals and higher photocatalytic activity under both visible light and UV irradiation. Crown Copyright © 2010.

Luo X.W.,Southwest University
Energy Education Science and Technology Part A: Energy Science and Research | Year: 2014

To find all solutions of NP problems with multi-peak, a novel adaptive GA based on cluster search is proposed. The algorithm is divided into two phases. In the first phase all individuals are evenly dispersed in question space and all potential peaks are searched as cluster centers in the procedure of genetic operation according to distance density.In the second phase limit the search near the selected clusters by reduction of cluster radius, gene transformation operator and limit of mutation radius to implement local adaptive refinement. Each cluster can transfer constantly towards a better area and carry out the transfer strategy of asymptotic solutions until all the candidate peaks have been searched.Taken n queens problem as an example, the algorithm has an excellent effect:the amount of solutions obtained in one calculation has been improved about 10 times more than that of SGA in similar circumstances.. © Sila Science. All rights reserved.

Xu H.,Southwest University | O'Brochta D.A.,University of Maryland College Park
Proceedings of the Royal Society B: Biological Sciences | Year: 2015

Genetic technologies based on transposon-mediated transgenesis along with several recently developed genome-editing technologies have become the preferred methods of choice for genetically manipulating many organisms. The silkworm, Bombyx mori, is a Lepidopteran insect of great economic importance because of its use in silk production and because it is a valuable model insect that has greatly enhanced our understanding of the biology of insects, including many agricultural pests. In the past 10 years, great advances have been achieved in the development of genetic technologies in B. mori, including transposon-based technologies that relyonpiggyBac-mediated transgenesis and genome-editing technologies that relyon protein- or RNA-guided modification of chromosomes. The successful development and application of these technologies has not only facilitated a better understanding of B. mori and its use as a silk production system, but also provided valuable experiences that have contributed to the development of similar technologies in non-model insects. This review summarizes the technologies currently available for use in B. mori, their application to the study of gene function and their use in genetically modifying B. mori for biotechnology applications. The challenges, solutions and future prospects associated with the development and application of genetic technologies in B. mori are also discussed. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

Li C.,Southwest University | Huang T.,Texas A&M University at Qatar | Wang H.,Chongqing Normal University
Neurocomputing | Year: 2013

In this article, a memcapacitor bridge circuit consisting of four identical memcapacitors is proposed. With this circuit, we can perform positive, negative and zero synaptic weightings. Weight programming is performed in a memcapacitor bridge circuit, while weight-multiplication processing is performed in a memcapacitor bridge synapse circuit. The current pulse is used in weight programming while the voltage pulse is used in weight-multiplication processing. Simulations are done with a nonlinear drift memcapacitor model. © 2013 Elsevier B.V.

Chen J.R.,Southwest University | Jiao X.X.,Southwest University | Luo H.Q.,Southwest University | Li N.B.,Southwest University
Journal of Materials Chemistry B | Year: 2013

Two novel probe-label-free electrochemical aptasensors based on methylene blue (MB)-anchored graphene oxide (GO) amplification were developed for thrombin (TB) and ATP detection, taking advantage of the specific binding affinity of the aptamer towards the target and the different affinities of GO for MB, ssDNA, dsDNA, and G-quadruplex. © The Royal Society of Chemistry 2013.

Wu Z.L.,Southwest University | Zhang P.,Southwest University | Gao M.X.,Southwest University | Liu C.F.,Southwest University | And 3 more authors.
Journal of Materials Chemistry B | Year: 2013

Nitrogen-doped carbon dots (CDs) have attracted great interest due to their extraordinary properties, especially their enhanced emission efficiency, and thus a facile synthesis of nitrogen-doped CDs with high emission efficiency is critical for practical applications. To improve the emission efficiency of CDs, herein we employed Bombyx mori silk, which has high nitrogen content, as a raw material to prepare photoluminescent nitrogen-doped carbon dots through one-pot hydrothermal synthesis, and found that the as-prepared CDs have a photoluminescence (PL) quantum yield of 13.9%, and display amphoteric properties depending on the pH, are highly photostable, have low toxicity and are suitable for bioimaging. © 2013 The Royal Society of Chemistry.

Qu F.,Southwest University | Dou L.L.,Southwest University | Li N.B.,Southwest University | Luo H.Q.,Southwest University