Jinan, China
Jinan, China

Shandong University is a public comprehensive university in Shandong, China. It is one of the largest universities in China by student population and is supported directly by the national government.Present-day Shandong University is the result of multiple mergers as well as splits and restructurings that have involved more than a dozen academic institutions over time. The oldest of Shandong University's precursor institutions, Cheeloo University, was founded by American and English mission agencies in the late 19th century . Tengchow College was the first modern institution of higher learning in China. Shandong University derives its official founding date from the Imperial Shandong University established in Jinan in November 1901 as the second modern national university in the country.Shandong University has seven campuses, all but one of which are located in the provincial capital city of Jinan. A campus to the northeast of the port city of Qingdao is under construction. The university has been classified as a National Key University by the Chinese Ministry of Education since 1960. It has been included in major national initiatives seeking to enhance the international competitiveness of the top-tier universities in China such as Project 985 and Project 211.Shandong University offers master and doctoral degree programs in all major academic disciplines covering the humanities, science and engineering, as well as medicine. Wikipedia.

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Qiu C.-X.,Shandong University | Qiu C.-X.,Hong Kong Polytechnic University | Zhu S.,Hong Kong Polytechnic University
Engineering Structures | Year: 2017

This study proposes a performance-based seismic design (PBSD) method for steel braced frames with novel self-centering (SC) braces that utilize shape memory alloys (SMA) as a kernel component. Superelastic SMA cables can completely recover deformation upon unloading, dissipate energy without residual deformation, and provide SC capability to the frames. The presented PBSD method is essentially a modified version of the performance-based plastic design with extra consideration of some special features of SMA-based braced frames (SMABFs). Four six-story concentrically braced frames with SMA-based braces (SMABs) are designed as examples to illustrate the efficacy of the proposed design method. In particular, the variability in the hysteretic parameters of SMAs, such as the phase-transformation stiffness ratio and the energy dissipation factor, is considered in the PBSD method. Accordingly, four SMABFs are designed with different combinations of these hysteretic parameters. The seismic performance of the designed frames is examined at various seismic intensity levels. Results of nonlinear time-history analyses indicate that the four SMABFs can successfully achieve the prescribed performance objectives at three seismic hazard levels. The comparisons among the designed frames reveal that the SMABs with greater hysteretic parameters result in a more economical design in terms of the consumption of steel and SMA materials. © 2016 Elsevier Ltd

Cui H.-T.,Shandong University
2016 1st IEEE International Conference on Computer Communication and the Internet, ICCCI 2016 | Year: 2016

A model of big data security service is put forward for large data providers, users and cloud service providers, in order to achieve shared services of reliable data security. Security of technology framework is established from four levels including a large resource set for searching, matching and packaging data, large data resources decomposition modeling planning, trust evaluation and optimization, and big data algorithm, on the aspect of access security mechanism, data security, network transmission security and cloud storage security to protect large data. © 2016 IEEE.

Du K.,Shandong University | Xie C.,University of Birmingham | Ouyang X.,East China Normal University
Renewable and Sustainable Energy Reviews | Year: 2017

As the world leader in CO2 emissions, China is a key focus for climate change mitigation. In this paper, we conducted a cross-province comparison of CO2 emission trends in China from 2006 to 2012. We determined effects of CO2 emission factor (EMF), energy mix change (EMX), potential energy intensity change (PEI), industrial structure (STR), economic activity (EAT), technological change (BPC) and energy efficiency change (EC) as underlying forces of CO2 emission changes with production-based decomposition. Compared to other production-theory decomposition analyses (PDA), the method used in this paper can overcome the weakness of PDA on the measurement of structural changes and energy mix effect. The results provided strong evidence that EAT is the main driver behind rising emissions, while changes in PEI, EMX and EC have led to CO2 emission reductions in most provinces/municipalities in China. In particular, we introduced the global benchmark technology to establish the relationship between CO2 emissions and energy use technology. The potential CO2 reductions in China were further measured under the scenarios of contemporaneous technology and global technology. The principal empirical implication is that the promotion of energy conservation technology and reductions in inter-regional technological disparity would be effective in reducing CO2 emissions in technically inefficient regions. © 2017 Elsevier Ltd

Zhang J.,Shandong University
Journal of Computational and Theoretical Nanoscience | Year: 2016

With social progress and economical rapidly development, the problem of an aging population has become increasingly prominent. As a country with the largest population in the world, China is confronting problems of hundreds of millions of old people's survival and development, the accompanied social problems have also constantly gone deeper, improving and promoting living quality of old people as well as improving happiness index of old people are important means to solve aging social contradiction. Happiness index as one of the focus in positive psychology research, it not only can evaluate a person's living quality but also can measure a person's psychological health conditions and psychological development level. The paper mainly studies the relations between physical exercises and old people happiness index. The paper takes over 60 years old aged as research objects, divides them into four groups according to physical exercises status, values individual character P, survival demand E, advanced psychological demand H, gets happiness index of all people according to formula that happiness is equal to P plus 5E and 3H. By regression analysis, it gets that physical exercises are positive correlated to old people happiness index that is proper physical exercises would enhance old people's feeling of happiness. It suggests old people to participate in more physical exercises to promote their happiness index. Copyright © 2016 American Scientific Publishers All rights reserved.

Jiang Q.,Shandong University | Xiang L.,Shandong University
IEEE Sensors Journal | Year: 2017

For the problem that the accuracy of the traditional the fiber Bragg grating (FBG) tactile sensor array unit is relatively low, which is caused by the lateral force. In this paper, we focused study on the small-structures of a single node of the array sensing unit, and designed the small-structures that can convert the exerted external force to the fiber axis tensile deformation. After using the finite-element analysis software to simulate and analyze the four kinds of small-structures, two kinds of small-structures were chosen for further research. In order to verify the feasibility of the chosen small-structures, a series of system performance tests were conducted. For the structure containing the arched bridge, the natural frequency is 17 Hz and the sensitivity is 0.38 nm/N. For the structure which contains a small hole and the FBGs locating in bottom position, the natural frequency is about 18 Hz and the sensitivity is 0.29 nm/N. The experimental results match the simulation results to demonstrate the good performance (high sensitivity and good linearity) of both the small-structures. In the performance tests for the FBG tactile sensor array unit based on one kind of the designed small-structure, the average positioning error is 0.057 cm2 and the average sensing force value error is 0.038 N. The array sensing unit has relatively high accuracy, which is expected to be used in the actual project. © 2017 IEEE.

ABSTRACT: Patients with stomach cancer are at high risk to experience suicidal ideation. Strain theory of suicide assumes that suicide is preceded by psychological strain. Despite wide international acceptance of the theory, its use with a sample of patients with stomach cancer has not previously been reported. The aims were to examine the relationship between psychological strain and suicidal ideation among patients with stomach cancer and to determine whether psychopathological factors act as mediators. A cross-sectional study was undertaken involving subjects with no history of mental disorder, and questionnaires were administered by face-to-face interview. Patients who experienced more psychological strain, especially coping strain, are more likely to experience suicidal ideation. The mediation effects of hopelessness and psychological distress are significant. Psychological strain, hopelessness, and psychological distress may be the vital factors among patients with stomach cancer in the suicide-risk assessment interview and for care planning and psychological intervention. Copyright © 2017 Wolters Kluwer Health, Inc. All rights reserved.

Chen S.,Southwestern University of Finance and Economics | Jiang X.Y.,Shandong University
Computers and Mathematics with Applications | Year: 2017

In this paper, we study an inverse problem of parameters estimation for a new time-fractional heat conduction model in multilayered medium. In the anomalous thermal diffusion model, we consider the fractional derivative boundary conditions and the conduction obeys modified Fourier law with Riemann–Liouville fractional operator of different order in each layer. For the direct problem, we construct an effective finite difference scheme by using the balance method to deal with the discontinuity interface. For the inverse problem, we apply the nonlinear conjugate gradient (NCG) method with different conjugated coefficients to simultaneously identify the fractional exponent in each layer. Finally, we use experimental data to verify the effectiveness of the proposed technique, in which the Jacobian matrix is achieved by a derivative-free approach. We analyze the sensitivity coefficients and the convergence behaviors of the NCG algorithm. The simulation results confirm that the fractional heat conduction model with estimated parameters gives a more accurate fitting than the classical counterpart and the NCG method is a feasible and effective technique for the inverse problem of parameters estimation in fractional model. © 2016 Elsevier Ltd

Zhou Z.,Shandong University | Ma S.,Shandong University
ChemMedChem | Year: 2017

The treatment of the infections caused by Pseudomonas aeruginosa, an opportunistic Gram-negative bacterium, is very difficult. High intrinsic tolerance toward common antibiotics and the development of new resistant strains challenge us to find a new treatment as soon as possible. PqsD is an enzyme essential for the P. aeruginosa quorum-sensing apparatus, which catalyzes the final and key step in the biosynthesis of 4-hydroxy-2-heptylquinolone (HHQ), which is a signal molecule of the P. aeruginosa quorum-sensing system. In this review, following an outline on their structures, we present a brief introduction of the PqsD inhibitors including their mechanisms of action, inhibitory activity, and structure–activity relationships. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim

Jin C.,Shandong University | Ma S.,Shandong University
MedChemComm | Year: 2017

Metabotropic glutamate receptors (mGlu receptors) belong to the G-protein-coupled receptors superfamily. They are divided into three groups, in which group II and group III belong to presynaptic receptors that negatively modulate glutamate and γ-aminobutyric acid (GABA) release when activated. In this review, we introduce not only the functions of mGlu receptors, but also the group II and group III allosteric modulators and agonists/antagonists reported over the past five years according to a classification of their structures, with a specific focus on their biological activity and selectivity. In particular, the structure of these compounds and the future directions of ideal candidates are highlighted. © The Royal Society of Chemistry.

Liver kinase B1 (LKB1) is a serine/threonine protein kinase ubiquitously expressed in mammalian cells. It was first identified in Peutz-Jeghers syndrome as a tumor suppressor gene. Whether endothelial LKB1 regulates angiogenesis and tumor growth is unknown. In this study, we generated endothelial cell-specific LKB1-knockout (LKB1endo-/-) mice by crossbreeding vascular endothelial-cadherin-Cre mice with LKB1flox/flox mice. Vascular endothelial growth factor (VEGF) level was highly co-stained in endothelial cells but not in macrophages in LKB1endo-/- mice. Consistently, LKB1endo-/- mouse tissues including the lung, skin, kidney and liver showed increased vascular permeability. Tumors implanted in LKB1endo-/- mice but not macrophage-specific LKB1-knockout mice grew faster and showed enhanced vascular permeability and increased angiogenesis as compared with those implanted in wild-type mice. Injection of VEGF-neutralizing antibody but not the isotype-matched control antibody decreased endothelial-cell angiogenesis and tumor growth in vivo. Furthermore, LKB1 deletion enhanced mouse retinal and cell angiogenesis, and knockdown of VEGF by small-interfering RNA decreased endothelial cell proliferation and migration. Re-expression of LKB1 or knockdown of VEGF receptor 2 decreased the overproliferation and -migration observed in LKB1endo-/- cells. Mechanistically, LKB1 could bind to the VEGF transcription factor, specificity protein 1 (Sp1), which then inhibited the binding of Sp1 to the VEGF promoter to reduce VEGF expression. Endothelial LKB1 may regulate endothelial angiogenesis and tumor growth by modulating Sp1-mediated VEGF expression.Oncogene advance online publication, 27 March 2017; doi:10.1038/onc.2017.61. © 2017 Macmillan Publishers Limited, part of Springer Nature.

Tian G.,Shandong University | Liu Y.,Shandong University
Physical Chemistry Chemical Physics | Year: 2017

Ubiquinone plays a pivotal role in the aerobic cellular respiratory electron transport chain, whereas ferulic acid decarboxylase (FDC) is involved in the biosynthesis of ubiquinone precursor. Recently, the complete crystal structure of FDC (based on the co-expression of the A. niger fdc1 gene in E. coli with the associated ubix gene from E. coli) at high resolution was reported. Herein, the detailed catalytic non-oxidative decarboxylation mechanism of FDC has been investigated by a combined quantum mechanics/molecular mechanics (QM/MM) approach. Calculation results indicate that, after the 1,3-dipolar cycloaddition of the substrate and cofactor, the carboxylic group can readily split off from the adduct, and the overall energy barrier of the whole catalytic reaction is 23.5 kcal mol-1. According to the energy barrier analysis, the protonation step is rate-limiting. The conserved protonated Glu282 is suggested to be the proton donor through a "water bridge". Besides, two cases, that is, the generated CO2 escapes from the active site or remains in the active site, were considered. It was found that the prolonged leaving of CO2 can facilitate the protonation of the intermediate. In particular, our calculations shed light on the detailed function of both cofactors prFMNiminium and prFMNketamine in the decarboxylation step. The cofactor prFMNiminium is the catalytically relevant species compared with prFMNketamine. © the Owner Societies 2017.

Chen M.,Shandong University | Guo X.,Shandong University
Nonlinear Analysis: Real World Applications | Year: 2017

In this paper, we investigate an initial boundary value problem for 1D compressible Navier–Stokes/Allen–Cahn system, which describes the motion of a mixture of two viscous compressible fluids. We establish the global existence and uniqueness of strong and classical solutions of Navier–Stokes/Allen–Cahn system by using the energy estimates, structure of the equations and the properties of one dimension. Here, we emphasize that the initial vacuum is allowed here. © 2017 Elsevier Ltd

Ren Y.,Shandong University | Zhang S.J.,Shandong University
CrystEngComm | Year: 2017

Optical quality tetragonal phase quasi one-dimensional single-crystalline fibers of potassium di-hydrogen phosphate with a large length-to-diameter ratio and high flexibility have been grown. Efficient guided-wave optical second harmonic generation is achieved along the growth axis. The single-crystal fibers open great potential of potassium di-hydrogen phosphate crystals in micro-photonic applications. © The Royal Society of Chemistry.

Lu H.,Shandong University | Feng S.,Shandong University
Journal of Polymer Science, Part A: Polymer Chemistry | Year: 2017

In this article, supramolecular silicone elastomers with self-healing function were first prepared by simple and controllable “salt-forming vulcanization” of polyaminopropylmethylsiloxane with acids. Their structures and micrographs were verified by Fourier transform infrared spectra, Small-angle X-ray scattering experiments and atomic force microscope. The experimental results showed that the ion-association complexes were formed during vulcanization, and the obtained elastomers displayed self-healing and good mechanical properties even if the cross-linking agent was excessed. The thermogravimetric analysis showed that the elastomers crosslinked by inorganic acid were stable under high temperature. Unexpectedly, bionic structures were observed in the elastomers, which further changed the hydrophobicity of the surfaces of the elastomers physically. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017, 55, 903–911. © 2017 Wiley Periodicals, Inc.

Zhao H.,Shandong University | Du L.,Shandong University
Environmental Science: Processes and Impacts | Year: 2017

In this study, the stability of clusters formed by the trans- and cis-isomers of nitrous acid (HONO) with dimethylamine (DMA) and water has been characterized by density functional theory. The large red shifts of the OH-stretching transitions of both HONO isomers in the clusters indicate the formation of strong hydrogen bonds. At standard temperature and pressure, H2O (acceptor) binds to HONO (donor) with binding energies of -25.0 to -24.6 kJ mol-1, less stable than those of DMA (acceptor) with HONO (donor) (-50.5 to -45.3 kJ mol-1). Our findings indicate that hydration enhances proton transfer from HONO to DMA, and consequently increases the interaction strength (binding energies = -67.8 to -78.6 kJ mol-1). The topological and generalized Kohn-Sham energy decomposition confirms strong hydrogen bond interactions. The clustering of HONO with DMA in the atmosphere is negligible as compared to the important H2SO4-DMA clusters. © 2017 The Royal Society of Chemistry.

Zhang Y.,Shandong University | Yan P.,Shandong University
Journal of Intelligent Material Systems and Structures | Year: 2017

Hysteresis nonlinearity widely exists in piezoelectric actuated nano-positioning applications, which degrades their tracking accuracy and limits their precision positioning applications. This paper presents a novel hysteresis modeling and compensation approach to alleviate the adverse effect of the asymmetric and rate-dependent hysteresis nonlinearity for a piezoelectric transducer actuated servo stage. By integrating a generalized input function with the play operator of the classical Prandtl-Ishlinskii model, a novel polynomial-based rate-dependent Prandtl-Ishlinskii (PRPI) model is proposed to capture the hysteresis behavior of the piezoelectric positioning stage, where a polynomial function of input and a time rate function of input are introduced to formulate the generalized input function. Meanwhile, a new adaptive differential evolution optimization algorithm is developed to identify the parameters of the proposed PRPI hysteresis model. Based on the PRPI hysteresis model with the identified parameters, an inverse feedforward controller is constructed to achieve the accurate tracking motion. Furthermore, the hysteresis compensation error of the proposed PRPI model is theoretically analyzed. Finally, comparative experiments are conducted, and the experimental results provided in this paper demonstrate the effectiveness and superiority of the proposed inverse PRPI model compensation approach. © SAGE Publications.

Zhang Y.,Shandong University | Wang R.,Shandong University
Diamond and Related Materials | Year: 2017

A new oxidative-adsorptive desulfurization (OADS) process using graphene oxide (GO) and HNO3 modified carbon black (mCB) as adsorbents, and octanal-air as oxidation system was investigated under mild conditions in model fuel. GO was prepared by modified Hummer's method and characterized by X-ray diffraction (XRD), transition electron microscopy (TEM), scanning electron microscopy (SEM) and fourier transform infrared spectroscopy (FT-IR). In the OADS/Nanocarbon system, molar ratio of S and octanal, mass ratio of model fuel and nanocarbon, OADS temperature was optimized to be 24:1, 200:1 and 60 °C respectively. High desulfurization uptakes of 45.1 and 45.4 mg-S/g-sorb were achieved under OADS system on GO and mCB, which are much higher than that under adsorptive desulfurization (ADS) system without in situ oxidation of dibenzothiophene (DBT). The desulfurization reactivity of various sulfur compounds in OADS system followed the order: Thiophene (TH)>DBT > 4, 6-dimethyldibenzothiophene (4, 6-DMDBT)> Thianaphthene (BT) over GO, and 4, 6-DMDBT > TH > DBT > BT over mCB. Remarkably, 4, 6-DMDBT and TH could be effectively removed with the desulfurization efficiencies of 96.1% and 98.4%, respectively. The desulfurization capacity of GO could be completely regenerated in three recycles. © 2016 Elsevier B.V.

Shi K.,Shandong University
Journal of Computational and Theoretical Nanoscience | Year: 2017

Network information security is controlled by various factors, so its evaluation is a complicated system engineering. In response to the complexity and uncertainty of such factors, we carry out a research on network information security evaluation and propose an evaluation model and algorithm based on grey relational clustering analysis. A comprehensive analysis is made concerning the influencing factors of network information security to establish an evaluation index system for network information security. Furthermore, ideal domains of various security levels are established through normalization of different evaluation indexes, hence calculating the grey relational coefficient and grade between target object and such ideal domains. As a result, we determine the category of network information security level. Finally, a practical case demonstrates that the proposed model is feasible and operable. Copyright © 2017 American Scientific Publishers.

Zhang S.,Shandong University | Liu Z.,Shandong University | Fang Q.,Shandong University
Organic Letters | Year: 2017

A series of pyrene-fused thioxanthenes have been synthesized via a new concise route, and their crystal structures and photophysical properties have been fully investigated. The eight-ring fused dipyrene-thioxanthene (DPTA) can crystallize to monoclinic and triclinic X-ray structures, and their precursor has been isolated as two stable atropisomers with different photophysical properties. The EHOMO becomes higher and the Eg become narrower as more thioxanthene unit being fused with pyrene. © 2017 American Chemical Society.

Zhu W.-X.,Shandong University | Zhang J.-Y.,Shandong University
Physica A: Statistical Mechanics and its Applications | Year: 2017

Based on VSP (Vehicle Specific Power) model traffic real emissions were theoretically classified into two parts: basic emission and additional emission. An original additional emission model was presented to calculate the vehicle's emission due to the signal control effects. Car-following model was developed and used to describe the traffic behavior including cruising, accelerating, decelerating and idling at a signalized intersection. Simulations were conducted under two situations: single intersection and two adjacent intersections with their respective control policy. Results are in good agreement with the theoretical analysis. It is also proved that additional emission model may be used to design the signal control policy in our modern traffic system to solve the serious environmental problems. © 2016 Elsevier B.V.

Meng F.,Shandong University
Annals of Plastic Surgery | Year: 2017

BACKGROUND: Wound tension reduction is still a challenge to surgeons. Over the years, many techniques have been proposed to avoid this issue. In this paper, we present a new suture technique. OBJECTIVES: To investigate the tension-reduction effectiveness of the modified subcutaneous buried horizontal mattress suture compared with the vertical buried mattress suture technique. METHODS: Two suture techniques, the vertical buried mattress suture (group A) and the modified subcutaneous buried horizontal mattress suture (group B), were performed on paired samples of symmetrical skin flaps. An equal pulling force was applied to each paired sutured flap, and the dehiscences of the samples in the two groups were compared. Then, after the periodic mechanical pulling force was recorded, the dehiscences were compared again. RESULTS: The dehiscences of the vertical buried mattress suture samples (group A) were much wider than their corresponding samples. Modified subcutaneous buried horizontal mattress suture samples (group B) remained well closed with no or minimal dehiscence, under various tensions, even after mechanical pulling force was applied. CONCLUSION: The modified subcutaneous buried horizontal mattress suture greatly decreased the tension on the dermis and subcutaneous tissue in our in vitro experiment. Copyright © 2017 Wolters Kluwer Health, Inc. All rights reserved.

Zhang L.,Taiyuan University of Technology | Xie S.,Shandong University
Physics Letters, Section A: General, Atomic and Solid State Physics | Year: 2017

We reveal that bilayer polyacene can be the gapped state due to the intralayer Peierls instability. There are six topologically inequivalent Peierls-distorted structures and they are degenerate in energy. The external electric field can tune the Peierls gap and induce the semiconductor-to-metallic phase transitions. The optical conductivity spectra are calculated in an attempt to categorize the Peierls-distorted structures. The strength of the interlayer coupling essentially affects the electronic properties and the optical selection rules. © 2017 Elsevier B.V.

Zhang P.,Shandong University | Liu Z.,Shandong University
Applied Surface Science | Year: 2017

In this research, the enhancements of surface integrity and corrosion resistance of the laser cladded parts by combined hard turning with low plasticity burnishing (LPB) were presented by both potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) methods. The investigated results indicated that the corrosion resistance of the laser cladded parts could be improved by combined hard turning with LPB than by sole hard turning. An innovative model was proposed to explain the corrosion mechanism of the laser cladded parts after hybrid machining. Both surface adsorption and passive film were observed to dominate the corrosion resistance of the hybrid machined Cr–Ni alloys by laser cladding. The surface integrity led to the inhomogeneity of passive film, and then altered the corrosion resistance of the machined samples. In terms of the surface integrity factors, residual compressive stresses and surface finish were found to play more important roles in improving the corrosion resistance than the grain refinement and microhardness of the machined surface layer materials did. Based on the research results, anti-corrosion parts with laser cladded alloys could be fabricated by hybrid machining using the combination of hard turning and LPB. © 2017 Elsevier B.V.

Zhang P.,Shandong University | Liu Z.,Shandong University
Journal of Cleaner Production | Year: 2017

Laser cladding has been widely used to repair some high value-added parts for remanufacturing or sustainable production. Additional machining is necessary when the repaired parts require high precision and high quality. However, using conventional cutting theory to machine cladding workpiece is always a challenging work. The depth of cut in machining cladding workpiece is restricted in a shallow range and exhibits comparable to the thickness of cladding. It is meaningful to explore the critical conditions for orthogonal machining two-layered workpiece formed by laser cladding. The critical condition was defined as an initiation of plastic deformation in substrate while elastic deformation still occurring in the bottom of cladding. These different deformation mechanisms attributed to the inferior physical-mechanical characteristics of the substrate compared to the cladding. The stresses induced by machining can reach the cladding-substrate interface and result in a premature plastic deformation in substrate. As a result, discontinuous plastic deformation zones generated in both subsurface and substrate. For this reason, a coupled thermo-mechanical model was developed to predict the plastic deformation behaviors in subsurface and substrate materials. It was found that the ratio of uncut chip thickness to critical cladded thickness ranged from 0 to 0.678 with increase of uncut chip thickness. It meant that the thicker the cladding was, the more difficult it would be to induce a premature plastic deformation in the substrate. Lower cutting force but higher specific cutting energy was found under lower uncut chip thickness. Thinner cladding was not recommended for purpose of repairing. The results are expected to provide fundamentals to weigh pre-cladded thickness and cutting parameters in a post machining process for manufacturing sustainability. © 2017 Elsevier Ltd

Yuan L.,Shandong University
Progress In Electromagnetics Research M | Year: 2017

In this paper, a feature fusion algorithm is proposed for automatic target recognition based on High Resolution Range Profiles (HRRP). The proposed algorithm employs Convolution Neural Network (CNN) to extract fused feature from the time-frequency features of HRRP automatically. The time-frequency features used include linear transform and bilinear transform. The coding of the CNN’s largest output node is the target category, and the output is compared with a threshold to decide whether the target is classified to a pre-known class or an unknown class. Simulations by four different aircraft models show that the proposed feature fusion algorithm has higher target recognition performance than single features. © 2017, Electromagnetics Academy. All rights reserved.

Prediction models of atrial fibrillation (AF) have been developed; however, there was no AF prediction model validated in Chinese population. Therefore, we aimed to investigate the incidence of AF in urban Han Chinese health check-up population, as well as to develop AF prediction models using behavioral, anthropometric, biochemical, electrocardiogram (ECG) markers, as well as visit-to-visit variability (VVV) in blood pressures available in the routine health check-up. A total of 33 186 participants aged 45–85 years and free of AF at baseline were included in this cohort, to follow up for incident AF with an annually routine health check-up. Cox regression models were used to develop AF prediction model and 10-fold cross-validation was used to test the discriminatory accuracy of prediction model. We developed three prediction models, with age, sex, history of coronary heart disease (CHD), hypertension as predictors for simple model, with left high-amplitude waves, premature beats added for ECG model, and with age, sex, history of CHD and VVV in systolic and diabolic blood pressures as predictors for VVV model, to estimate risk of incident AF. The calibration of our models ranged from 1.001 to 1.004 (P for Hosmer Lemeshow test >0.05). The area under receiver operator characteristics curve were 78%, 80% and 82%, respectively, for predicting risk of AF. In conclusion, we have identified predictors of incident AF and developed prediction models for AF with variables readily available in routine health check-up.Journal of Human Hypertension advance online publication, 30 March 2017; doi:10.1038/jhh.2017.23. © 2017 Macmillan Publishers Limited, part of Springer Nature.

Guan X.J.,Shandong University | Wang J.,Shandong University
IOP Conference Series: Materials Science and Engineering | Year: 2017

To investigate their dynamics and interaction mechanisms, the growth process of the two voids with different sizes during Czochralski silicon crystal growth were simulated by use of an established phase field model and its corresponding program code. On the basis of the several phase field numerical simulation cases, the evolution laws of the double voids were acquired as follows: the phase field model is capable to simulate the growth process of double voids with different sizes; there are two modes of their growth, that is, either mutual integration or competitive growth; the exact moment of their fusion can be also captured, and it is τ of 7.078 (simulation time step of 14156) for the initial vacancy concentration of 0.02 and the initial space between two void centers of 44Δx. © Published under licence by IOP Publishing Ltd.

Wang W.,Shandong University | Yu P.,University of Hong Kong
Computational Statistics and Data Analysis | Year: 2017

The existing differenced estimators of error variance in nonparametric regression are interpreted as kernel estimators, and some requirements for a “good” estimator of error variance are specified. A new differenced method is then proposed that estimates the errors as the intercepts in a sequence of simple linear regressions and constructs a variance estimator based on estimated errors. The new estimator satisfies the requirements for a “good” estimator and achieves the asymptotically optimal mean square error. A feasible difference order is also derived, which makes the estimator more applicable. To improve the finite-sample performance, two bias-corrected versions are further proposed. All three estimators are equivalent to some local polynomial estimators and thus can be interpreted as kernel estimators. To determine which of the three estimators to be used in practice, a rule of thumb is provided by analysis of the mean square error, which solves an open problem in error variance estimation which difference sequence to be used in finite samples. Simulation studies and a real data application corroborate the theoretical results and illustrate the advantages of the new method compared with the existing methods. © 2016 Elsevier B.V.

In the management of short bowel syndrome (SBS), the benefits of treatment with growth hormone (GH), glutamine, and enteral nutrition (EN) on intestinal adaptation among children patients is still controversial. The aim of present study is to determine whether GH, glutamine, and EN have positive effect on intestinal adaptation in children with SBS. Sixteen children with SBS (small bowel remnant length, 56.75 ± 8.09 cm; mean ± SE) were treated with GH (0.05 mg/kg/d), glutamine (0.45 mg/kg/d), plus EN-enriched fiber diet for four weeks. After four weeks of treatment, patients were discharged home; GH was discontinued, but the EN with glutamine was continued. Repeated treatment was performed if there were lose weight, dysplasia, or severe diarrhea. All patients completed the treatment. Body weight, intestinal absorptive capacity, and plasma levels of proteins were significantly improved after complete treatment, without any major adverse effects. On follow-up, no death was reported. Treatment with GH, glutamine, and EN in early stage significantly improved intestinal adaptation in pediatric patients with SBS. Furthermore, the positive effect of the treatment does not seem to be sustained once GH discontinued until the residual intestinal adaptation reaches its maximum.

Wang S.,Harvard University | Hassold T.,Washington State University | Hunt P.,Washington State University | White M.A.,Harvard University | And 3 more authors.
Cell | Year: 2017

Meiosis is the cellular program that underlies gamete formation. For this program, crossovers between homologous chromosomes play an essential mechanical role to ensure regular segregation. We present a detailed study of crossover formation in human male and female meiosis, enabled by modeling analysis. Results suggest that recombination in the two sexes proceeds analogously and efficiently through most stages. However, specifically in female (but not male), ∼25% of the intermediates that should mature into crossover products actually fail to do so. Further, this "female-specific crossover maturation inefficiency" is inferred to make major contributions to the high level of chromosome mis-segregation and resultant aneuploidy that uniquely afflicts human female oocytes (e.g., giving Down syndrome). Additionally, crossover levels on different chromosomes in the same nucleus tend to co-vary, an effect attributable to global per-nucleus modulation of chromatin loop size. Maturation inefficiency could potentially reflect an evolutionary advantage of increased aneuploidy for human females. Human female meiosis exhibits inefficient maturation of crossovers. This effect, alone and in synergy with other features, promotes high frequencies of aneuploid eggs. © 2017 Elsevier Inc.

Sarwar S.,Shandong University | Chen W.,Shandong University | Waheed R.,Shandong University
Renewable and Sustainable Energy Reviews | Year: 2017

Present study use the panel data of 210 countries over the period 1960–2014 to analyze the empirical relationship between economic growth, electricity consumption, oil price, gross fixed capital formation and population. The economic growth of developing countries with industrial infrastructure has higher significant association with electricity consumption as compared to oil price. We use oil price and electricity consumption jointly to study the highly predictive observer for economic growth. Furthermore, the data is categorized into income, OECD and regional level. Pedroni panel cointegration, fully modified OLS and panel vector error correction test apply to analyze the cointegration, short run and long run relationship between the variables. The results of full panel confirm a bidirectional relationship between electricity consumption and GDP, oil price and GDP, fixed capital formation, population and GDP. The results validate that developing countries heavily reliance on electricity consumption despite of oil prices for economic growth. Furthermore, the finding varies across income, OECD and regional level. In short run, growth and feedback hypothesis suggest that more vigorous electricity policies should be implemented to attain high economic growth © 2017

Zhang Y.,Shandong University | Gao S.,Shandong University | Gu T.,Shandong University
Solar Energy | Year: 2017

Manufacturers of photovoltaic panels typically only provide electrical parameters under standard reference condition (SRC) that is not sufficient to determine their overall performance. It is important for designers to find a flexible and reliable method to model and accurately predict I-V characteristics under varying operating conditions. This paper proposes a method to predict the I-V characteristics of a PV panel under varying operating conditions by combining the single diode model and explicit analytical model. The method takes temperature and solar irradiance as inputs and produces I-V characteristics under any operating condition as outputs, including the maximum power point, fill-factor, and entire I-V curve. Considering the aging effect, the parameters under the measured reference condition (MRC) are used for calculation instead of the manufacturer data at SRC where the process is as follows: (1) the shape parameters in the explicit analytical model were calculated from measurements at MRC; (2) the physical parameters in the single diode model were identified from the measured data at MRC and used for the prediction; (3) the physical parameters under any operating condition were calculated based on the dependence of the physical parameters on the temperature and solar irradiance; (4) the I-V characteristics were described and analyzed using the explicit analytical model because of its simplicity and explicit expression. Outdoor experiments were performed to validate the proposed method. Our calculated results show reasonable agreement with the experimental results. © 2017 Elsevier Ltd

Wei Z.-D.,Shandong University | Wang R.,Shandong University
Key Engineering Materials | Year: 2017

In this work, a new catalyst TiO2 @MOM has been successfully synthesized by coupling TiO2 with metal organic macromolecule (MOM) through hydrothermal-solvothermal two-step process. Having a high visible photocatalytic activity considerably superior to that of single TiO2, the fabrication of TiO2@MOM should provide a new way of upgrading the TiO2 - based catalyst. © 2017 Trans Tech Publications.

Wang L.,Shandong University | Liu X.,Shandong University
Journal of Orthopaedic Science | Year: 2017

Objective We collected the radiographic and clinical data of 129 AIS patients (Lenke type 1–6) to analyze the characteristics of cervical sagittal alignment in adolescent idiopathic scoliosis patients and the correlations between cervical sagittal alignment and global sagittal alignment, and clinical symptoms. Methods 129 patients with AIS and 48 adolescent volunteers were included in this study. The angles of the main thoracic curve, proximal thoracic curve, thoracolumbar curve, lumbar curve, C2-7 Cobb angle, T5-12 Cobb angle, L1-5 Cobb angle, pelvic incidence, pelvic tilt, sacrum slop, C2-7 sagittal vertical axis, C7-S1 sagittal vertical axis, and T1 pelvic angle were included in radiographic measurements. In addition, a 10-cm Visual Analogue Score was used to assess neck pain. Pearson correlation coefficients and t-test were used for statistical analysis. Results In the AIS group, C2-7 Cobb angle increased significantly compared with the control group, and it was significantly correlated with T5-12 Cobb angle and L1-5 Cobb angle. There was no significant correlation between C2-7 Cobb angle and coronal curvature in each Lenke type of patients. In the C2-7 SVA ≥ 3 cm group, C2-7 Cobb angle was related to T5-12 Cobb angle, L1-5 Cobb angle, pelvic incidence, and sacrum slop. In the cervical kyphosis group, T5-12 Cobb angle was significantly lower than that of the C2-7 Cobb angle ≥0 group. The C2-7 Cobb angle in the group with T5-12 Cobb angle >30° increased significantly compared with that in the group with T5-12 Cobb angle ≤30°. The Visual Analogue Score of neck pain of the cervical imbalance group was significantly higher than that of the cervical balance group. Conclusions The cervical sagittal alignment in AIS patients was related with thoracic kyphosis and lumbar lordosis, especially with thoracic kyphosis, but not with the coronal angle of thoracic and lumbar spine, and pelvic parameters. © 2016 The Japanese Orthopaedic Association

Zhang Y.,Shandong University | Gong H.,Shandong University
Journal of Luminescence | Year: 2017

A series of cerium-activated lutetium aluminum garnet (LuAG:Ce) phosphors were synthesized via a novel and fast microwave-induced solution combustion method. The influence of calcination temperature, metal ions/fuels ratio, content of active ions and LiF flux on microstructure, morphological feature and optical properties of prepared phosphors were investigated. The properties of phosphor samples were studied by means of X-ray diffraction technique, differential scanning calorimetry, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy and photoluminescence spectroscopy. Single-phase cubic crystalline LuAG:Ce formed at around 900 °C. The emission spectra displayed a characteristic broad green-yellow band of Ce3+ ions in the range of 460–700 nm. The phosphors exhibited optimal luminescent properties when the fuels /metal ions molar ratio was 0.5. The quenching concentration of Ce3+ in prepared LuAG:Ce powders was 1.0 mol% and the emission spectra showed a red shift at higher Ce3+ concentrations. The results also revealed that an appropriate amount of LiF significantly intensified the luminescence of LuAG:Ce phosphors, and it reached the maximum at 3 wt%. © 2016 Elsevier B.V.

Objective The predictive value of HALP in esophageal cancer is currently unclear. We aimed to evaluate the value of HALP in predicting platinum-based definitive chemoradiotherapy response in male patients with esophageal squamous cell carcinoma. Methods Data from all newly diagnosed patients with esophageal squamous cell carcinoma (ESCC) were collected from January 1, 2010 to December 31, 2014 in Qilu Hospital. The treatment protocol was definitive chemoradiotherapy consisting of docetaxel plus cisplatin or carboplatin. The response assessment of the definitive chemoradiotherapy was based on computed tomography (CT) and barium meal test results. Results A total of 39 patients were included in the present study. The median value of HALP was 48.34. The chemoradiotherapy response rate of patients in the low HALP value group was 35%, compared with 78.95% of patients in the high HALP group (P = 0.010). Additionally, the median progression-free survival in the 2 patient groups was significantly different (10.7 vs. 24.7 m, P = 0.041). In the multivariate analysis, patients with HALP higher than 48.34 had longer progression-free survival than patients with HALP of 48.34 or less (HR 2.745; 95% CI, 1.176–6.408; P = 0.020). However, there was no significant difference for overall survival between the high HALP group and low HALP group. Conclusion Our data suggested that pretreatment HALP could predict the platinum-based chemoradiotherapy response of tumors and progression free survival in male patients with ESCC. Therefore, HALP could be used in routine clinical practice to guide the therapeutic strategies for individual treatment in patients with ESCC. © 2017 Elsevier B.V.

Zhang C.,Shandong University | Tian Z.,Anhui University of Science and Technology
Journal of Autoimmunity | Year: 2017

Natural killer (NK) cells are lymphocytes of the innate immune system. They not only exert cell-mediated cytotoxicity against tumor cells or infected cells, but also play regulatory role through promoting or suppressing functions of other immune cells by secretion of cytokines and chemokines. However, overactivation or dysfunction of NK cells may be associated with pathogenesis of some diseases. NK cells are found to act as a two edged weapon and play opposite roles with both regulatory and inducer activity in autoimmune diseases. Though the precise mechanisms for the opposite effects of NK cells has not been fully elucidated, the importance of NK cells in autoimmune diseases might be associated with different NK cell subsets, different tissue microenvironment and different stages of corresponding diseases. The local tissue microenvironment, unique cellular interactions and different stages of corresponding diseases shape the properties and function of NK cells. In this review, we focus on recent research on the features and function of different NK cell subsets, particularly tissue-resident NK cells in different tissues, and their potential role in autoimmune diseases. © 2017.

Sun H.,Shandong University
RISTI - Revista Iberica de Sistemas e Tecnologias de Informacao | Year: 2016

Learning styles refers to the concept that individuals differ in regard to what mode of instruction or study is most effective for them. Because of individual has a different learning style, then the needs of learning materials are also different. With the heterogeneous proliferation of web devices, the delivery of learning materials on such devices becomes subject to more and more requirements. Personalized learning content adaptation becomes increasingly important to meet the diverse needs imposed by users, usage contexts, and infrastructure. Historical server logs offer a wealth of information on hardware capabilities, learners' preferences, and network conditions, which can be utilized to respond to a new user request with the personalized learning materials created from a previous similar request. In this paper, we propose a personalized learning system, which applies clustering and decision tree approaches, to efficiently manage a large number of historical learners' requests. The proposed method will intelligently and directly deliver proper personalized learning materials by means of the proposed adaptation decision and content synthesis processes.

Mao Y.,Shandong University
Arteriosclerosis, Thrombosis, and Vascular Biology | Year: 2017

OBJECTIVE—: Metabolic stress in obesity induces endothelial inflammation and activation, which initiates adipose tissue inflammation, insulin resistance, and cardiovascular diseases. However, the mechanisms underlying endothelial inflammation induction are not completely understood. Stimulator of interferon genes (STING) is an important molecule in immunity and inflammation. In the present study, we sought to determine the role of STING in palmitic acid–induced endothelial activation/inflammation. APPROACH AND RESULTS—: In cultured endothelial cells, palmitic acid treatment activated STING, as indicated by its perinuclear translocation and binding to interferon regulatory factor 3 (IRF3), leading to IRF3 phosphorylation and nuclear translocation. The activated IRF3 bound to the promoter of intercellular adhesion molecule 1 and induced intercellular adhesion molecule-1 expression and monocyte–endothelial cell adhesion. When analyzing the upstream signaling, we found that palmitic acid activated STING by inducing mitochondrial damage. Palmitic acid treatment caused mitochondrial damage and leakage of mitochondrial DNA into the cytosol. Through the cytosolic DNA sensor cyclic GMP-AMP synthase, the mitochondrial damage and leaked cytosolic mitochondrial DNA activated the STING–IRF3 pathway and increased intercellular adhesion molecule-1 expression. In mice with diet-induced obesity, the STING–IRF3 pathway was activated in adipose tissue. However, STING deficiency (Sting) partially prevented diet-induced adipose tissue inflammation, obesity, insulin resistance, and glucose intolerance. CONCLUSIONS—: The mitochondrial damage-cyclic GMP-AMP synthase–STING–IRF3 pathway is critically involved in metabolic stress–induced endothelial inflammation. STING may be a potential therapeutic target for preventing cardiovascular diseases and insulin resistance in obese individuals. © 2017 American Heart Association, Inc.

Ruining Y.,Shandong University | Ruining Y.,National Machine Tool Product Quality Supervision and Inspection Center
Proceedings - 9th International Conference on Measuring Technology and Mechatronics Automation, ICMTMA 2017 | Year: 2017

Aimed at irregular shape tiny revolving part, in the circumstances of mass production, consider the difficulties of contact detection, put forward the non contact detection method based on optical triangle test principle, photoelectric switch principle, grating displacement measurement principle and CCD image technology and auto-focusing technology, etc. Achieve the measurement of the specific location bounce error and aperture in bottom. It eliminated the influence of artificial factors in the traditional measuring method. © 2017 IEEE.

Wu D.,Sanford Burnham Institute for Medical Research | Wu D.,Shandong University | Rastinejad F.,Sanford Burnham Institute for Medical Research
Current Opinion in Structural Biology | Year: 2017

The mammalian basic helix-loop-helix-PER-ARNT-SIM (bHLH–PAS) transcription factors share common architectural features that include a bHLH DNA-binding domain and tandemly positioned PAS domains. The sixteen members of this family include the hypoxia-inducible factors (HIF-1α and HIF-2α), ARNT (also known as HIF-1β), CLOCK and BMAL1. Most bHLH-PAS proteins have been genetically linked to variety of diseases in humans, including cancers, metabolic syndromes and psychiatric conditions. To function as transcription factors, the bHLH-PAS proteins must form heterodimeric complexes. Recent crystallographic studies of HIF-α-ARNT and CLOCK-BMAL1 complexes have unveiled the organization of their multi-domain bHLH-PAS-A-PAS-B segments, revealing how these architectures can give rise to unique patterns of heterodimerization. As our structural understanding becomes better integrated with ligand-discovery and target gene identification, a more comprehensive picture of their architectural and functional properties will emerge. © 2016 Elsevier Ltd

BACKGROUND: Waist-to-height ratio (WHtR) is proposed as a simple and effective screening tool for abdominal obesity and cardiovascular disease risk factors. The present study examined the profiles of blood pressure (BP) among children and adolescents categorized by WHtR cutoffs. PATIENTS AND METHODS: A total of 28 074 (14 015 boys and 14 059 girls) students aged 7–17 years participated in the study. Height, waist circumference and BP of all patients were measured, and WHtR was calculated. Relatively high blood pressure (RHBP) status was defined as systolic BP and/or diastolic BP of at least the 95th percentile for age and sex. All patients were divided into three groups (low, moderate and high) according to their WHtR. BP level and the prevalence of RHBP among the three groups were compared. RESULTS: In both boys and girls, significant differences in BP level and the prevalence of RHBP were observed among the three groups (P<0.01). Children and adolescents aged 7–17 years in the ‘high WHtR group’ (≥0.5) had higher systolic BP and diastolic BP compared with those in the ‘low WHtR group’ (<0.4) by 6.07–11.49 and 3.28–6.34 mmHg for boys and 5.62–9.76 and 3.14–5.95 mmHg for girls; the ‘high WHtR group’ had the highest (34.02% for boys and 30.87% for girls) and the ‘low WHtR group’ had the lowest prevalence of RHBP (15.23% for boys and 12.53% for girls). CONCLUSION: High WHtR is associated with elevated BP. These findings emphasize the importance of the prevention of abdominal obesity to prevent future problems such as hypertension in children and adolescents. Copyright © 2017 Wolters Kluwer Health, Inc. All rights reserved.

Xia Y.,Shandong University | Xun L.,Washington State University
Methods in Molecular Biology | Year: 2017

Site-directed mutagenesis has been widely used for the substitution, addition or deletion of nucleotide residues in a defined DNA sequence. QuikChange™ site-directed mutagenesis and its related protocols have been widely used for this purpose because of convenience and efficiency. We have recently demonstrated that the mechanism of the QuikChange™ site-directed mutagenesis process is different from that being proposed. The new mechanism promotes the use of partially overlapping primers and commercial PCR enzymes for efficient PCR and mutagenesis. © Springer Science+Business Media New York 2017.

Liu X.,Shandong University | Wang R.,Shandong University
Fuel Processing Technology | Year: 2017

In this work, five peroxo heteropoly compounds (PHPCs) were synthesized and dissolved in four ionic liquids (ILs) to remove H2S. The Fourier transform infrared (FT-IR) spectrum, Raman spectrum, elemental analysis, Nuclear Magnetic Resonance (NMR) and X-Ray Diffraction (XRD) have demonstrated the successful synthesis of PHPC. Besides, the PHPC and IL were characterized by Thermogravimetry analysis (TGA). The desulfurization results showed that cetyltrimethylammonium peroxophosphomolybdate dissolved in 1-N-butyl-3-methylimidazolium bicarbonate has the best H2S removal capacity. Condition optimization experiments showed that a low H2S concentration and high PHPC concentration is in favor of H2S removal. The optimal absorption temperature is 95 °C at which the H2S removal efficiency could maintain nearly 100% for 2 h. The desulfurization product has been proved to be sulfur. The regeneration experiment showed that the desulfurization capacity of absorbent is weakened after regeneration because of the loss of peroxide. These results indicate that PHPC/IL solution has the potential to remove H2S. © 2017 Elsevier B.V.

RATIONALE: Parkinsonism can be secondary to many internal diseases, in some certain conditions, it seems that the clinical manifestations of parkinsonism presenting reversible. We report a case of patient with parkinsonism secondary to pseudohypoparathyroidism, who improved markedly after the supplement of serum calcium.PATIENT CONCERNS AND DIAGNOSES: A 52-year-old woman with acute parkinsonism was diagnosed as pseudohypoparathyroidism after the conducting of brain computed tomography, laboratory examinations, and gene detection. The son of the patient was also examined and was diagnosed as pseudohypoparathyroidism, who had ever complained of the history of epilepsy. The clinical manifestations of parkinsonism of the patient was reevaluated after the supplement of serum calcium according to the diagnosis.INTERVENTIONS AND OUTCOMES: The brain computed tomography revealed the basal ganglia calcification of the patient, accompanying by serum hypocalcemia and hyperphosphatemia. Loss of function mutation also confirmed the diagnosis. Five days after the therapy targeting at correction of serum hypocalcemia, the patient improved greatly in dyskinesia.LESSONS: This study reported a patient presenting as acute reversible parkinsonism, who was finally diagnosed as pseudohypoparathyroidism. It indicated us that secondary parkinsonism should be carefully differentiated for its dramatic treatment effect. And the family history of seizures might be an indicator for the consideration of pseudohypoparathyroidism.

Ma C.-C.,Shandong University | Liu Z.-P.,Shandong University
Anti-Cancer Agents in Medicinal Chemistry | Year: 2017

Background: Coumarins possess a broad spectrum of biological activities and are important pharmacophores in drug developments. Since aberrant upregulation of PI3K/Akt signaling is related to uncontrolled tumor cell proliferation, enhanced migration, and adhesion-independent tumor growth, it is of interests to find novel coumarin derivatives as anticancer agents targeting the PI3K/Akt signaling pathway. Objective: A variety of coumarin derivatives possessing the pyridinylurea units were designed to increase their potency and isoform selectivity against PI3Ks. Method: Novel coumarin analogs 4a–m were were prepared from 5-methylpyridin-2-ylamine in a straightforward way and their growth inhibitory activity against tumor cells was evaluated by a MTT assay. The inhibitory activity against PI3Kα, β, δ and γ was measured by luminescent assay. Akt phosphorylation inhibition and caspase 3 and PARP activation were measured by Western blot analysis. Apoptosis was measured by staining cells with annexin V-FITC and 7-AAD. Results: In general, these coumarin analogs exhibited good in vitro growth inhibitory activities against tumor K562, Hela, A549 and MCF-7 cells. Some of them showed comparable or better potency than BENC-511. Compounds 4b and 4h were much more potent PI3K inhibitors than S14161 or BENC-511. In addition, 4b was more selective to PI3Kα/β over PI3Kδ/γ, while 4h was a selective PI3Kα/β/δ inhibitor. Moreover, 4h could suppress the phosphorylation of Akt and induce K562 cell apoptosis. Conclusion: Coumarin derivatives possessing the pyridinylurea units are potential PI3K inhibitors and anticancer agents. These findings will be helpful for the future design of more potent and selective PI3K inhibitors. © 2017 Bentham Science Publishers.

Zhang L.,Shandong University | Zhu Q.,Shandong University
Mitochondrial DNA Part A: DNA Mapping, Sequencing, and Analysis | Year: 2017

Here we sequenced and characterized the complete mitochondrial genome (mitogenome) of Anthopleura midori from Weihai, China. This is the first species with sequenced mitogenome of genus Anthopleura. The A. midori mitogenome is 20 039 bp in length (GenBank accession no. KT989511). The overall base composition of the H-strand is 26.81% A, 17.45% C, 21.52% G, and 34.22% T. The base composition clearly showed the A–T skew. Similar to most other sea anemone in family Actiniidae, it contains 13 protein-coding genes, 2 rRNAs, 2 tRNAs, and some non-coding regions. The circular mitogenome codes entirely on the heavy strand and ND5 and COI genes were embedded by an intron. Phylogenetic analyses show that A. midori is related most closely to Phymanthus crucifer. © 2016 Informa UK Limited, trading as Taylor & Francis Group.

Urmossy K.,Shandong University
European Physical Journal A | Year: 2017

We propose the characterization of fragmentation functions by the energy fraction x˜ a hadron takes away from the energy of the jet measured in the frame co-moving with the jet. Besides, we propose the usage of the jet mass as the fragmentation scaleQ˜. We show that these two Lorentz-invariant variables emerge naturally in a microcanonical ensemble with conserved four-momentum. Then, we construct a statistical hadronisation model, in which, two features of the hadronic final states in various high-energy reactions (power law spectra and negative-binomial multiplicity distributions) can be connected simply. Finally, we analyse the scale dependence of the parameters of the model (power of the spectrum and mean energy per hadron) in the ϕ3 theory. Fitting fragmentation functions in diffractive positron-proton collisions, we obtain a prediction for the jet mass dependence of the hadron multiplicity distribution inside jets. © 2017, SIF, Springer-Verlag Berlin Heidelberg.

Yang R.,Shandong University | Liu G.-P.,University of South Wales | Liu G.-P.,Harbin Institute of Technology | Shi P.,Victoria University of Melbourne | And 3 more authors.
IEEE Transactions on Industrial Electronics | Year: 2014

This paper studies the problem of predictive output feedback control for networked control systems (NCSs) with random communication delays. A networked-predictive-control scheme is employed to compensate for the network-induced delay. Furthermore, the time-varying predictive controller with mixed random delays for networked systems is introduced. Then, the system is formulated as a Markovian jump system. New techniques are presented to deal with the distributed delay in the discrete-time domain. Based on the analysis of closed-loop NCSs, the designed predictive time-varying output feedback controller can guarantee system stability. Simulation example demonstrates the compensation for random communication delays and data loss in networked systems using the proposed predictive scheme. © 1982-2012 IEEE.

Li H.,Shandong University | Wang M.,University of Swansea
Nonlinear Dynamics | Year: 2013

In this technical note, the Hopf bifurcation in a new Lorenz-type system is studied. By analyzing the characteristic equations, the existence of a Hopf bifurcation is established. Some corresponding dynamics are also discussed briefly. Numerical simulations are carried out to illustrate the main theoretical results. © 2012 Springer Science+Business Media Dordrecht.

Li F.,Shandong University | Wang M.,University of Swansea
Nonlinear Dynamics | Year: 2013

In this paper, center conditions and bifurcation of limit cycles at the nilpotent critical point in a class of quintic polynomial differential system are investigated. With the help of the computer algebra system MATHEMATICA, the first 11 quasi-Lyapunov constants are deduced. As a result, sufficient and necessary conditions in order to have a center are obtained. The fact that there exist 11 small amplitude limit cycles created from the three-order nilpotent critical point is also proved. Henceforth, we give a lower bound of cyclicity of three-order nilpotent critical point for quintic Lyapunov systems. The results of Jiang et al. (Int. J. Bifurcation Chaos 19:2107-2113, 2009) are improved. © 2012 Springer Science+Business Media Dordrecht.

Wang Z.F.,University of Utah | Chen L.,Shandong University | Chen L.,Tsinghua University | Liu F.,University of Utah
Nano Letters | Year: 2014

Based on first-principles and tight-binding calculations, we report that the topological edge states of zigzag Bi(111) nanoribbon can be significantly tuned by H edge adsorption. The Fermi velocity is increased by 1 order of magnitude, as the Dirac point is moved from the Brillouin zone boundary to the Brillouin zone center, and the real-space distribution of Dirac states are made twice more delocalized. These intriguing changes are explained by an orbital filtering effect of edge H atoms, which pushes certain components of the p orbital of edge Bi atoms out of the band gap regime that reshapes the topological edge states. In addition, the spin texture of the Dirac states is also modified, which is described by introducing an effective Hamiltonian. Our findings not only are of fundamental interest but also have practical implications in potential applications of topological insulators. © 2014 American Chemical Society.

Li D.,Nanyang Technological University | Loh P.C.,Nanyang Technological University | Zhu M.,Shanghai JiaoTong University | Gao F.,Shandong University | Blaabjerg F.,University of Aalborg
IEEE Transactions on Power Electronics | Year: 2013

Traditional voltage-source inverter is limited by its only voltage step-down operation, while current-source inverter is limited by its only current step-down mode. In order to add an extra boosting flexibility while keeping the number of active semiconductors unchanged, voltage-type and current-type Z-source inverters were earlier proposed. These new classes of inverters are generally more robust and less sensitive to electromagnetic noises. However, their boosting capabilities are somehow compromised by high component stresses and poorer spectral performances caused by low modulation ratios. Their boosting gains are, therefore, limited in practice. To overcome these shortcomings, the generalized switched-inductor and switched-capacitor Z-source inverters are proposed, whose extra boosting abilities and other advantages have already been verified in simulation and experiment. © 1986-2012 IEEE.

Li D.,Nanyang Technological University | Loh P.C.,Nanyang Technological University | Zhu M.,Shanghai JiaoTong University | Gao F.,Shandong University | Blaabjerg F.,University of Aalborg
IEEE Transactions on Power Electronics | Year: 2013

Inverters with high-output voltage gain usually face the problem of high-input current flowing through their components. The problem might further be exaggerated if the inverters use high-frequency magnetic devices like transformers or coupled inductors. Leakage inductances of these devices must strictly be small to prevent overvoltages caused by switching of their winding currents. To avoid these related problems, cascaded trans-Z-source inverters are proposed. They use multiple magnetic cells in an alternately cascading pattern rather than a single magnetic cell with large turns ratio. Simulation and experimental results have shown that the multicell inverters can produce the same high-voltage gain, while keeping currents and voltages of the components low. The inverters can also step down their output voltages like a traditional voltage-source inverter without compromising waveform quality. © 1986-2012 IEEE.

Wang K.-Y.,Shandong University | Wang K.-H.,China Institute of Technology | Zhang Z.-P.,Second People Hospital of Muping District
Journal of the European Academy of Dermatology and Venereology | Year: 2011

Background Vitiligo can adversely affect the quality of life and sexual relationships of patients. Combination of the DLQI with the generic SF-36 and ENRICH may give further insight in the evaluation of the burden in vitiligo patients. Objective We sought to assess the health-related quality of life (HRQoL) and marital quality of Chinese vitiligo patients and to identify the relevant clinical and socio-demographic determinants. Methods A total of 101 vitiligo patients and 126 healthy controls completed the questionnaires. HRQoL was measured using DLQI and SF-36, and marital quality was measured using the ENRICH marital inventory. Results Patients with vitiligo experienced significantly impaired health-related quality of life and unstable marital relationships. Gender, distribution pattern of vitiligo and disease severity were independent predictors of DLQI, SF-36 and ENRICH in this cohort. Conclusions Vitiligo is associated with impairment of HRQoL and marital quality among Chinese patients. Alongside the medical interventions, the psychological and sociocultural assessment and intervention should be an essential part of the management of these cases. © 2010 European Academy of Dermatology and Venereology.

Guo X.,South China University of Technology | Zhang Q.,South China University of Technology | Sun Y.,Peking University | Zhao Q.,Peking University | And 2 more authors.
ACS Nano | Year: 2012

Selective growth/etching of hybrid materials is very important for the rational synthesis of hierarchical structures and precise modulation of their physical properties. Here, the lateral etching of the core-shell Au@Ag nanorods is achieved by FeCl 3 at room temperature, producing a number of dumbbell-like Ag-tipped Au nanorods. This selective etching at the side of the core-shell nanorods is attributed to the increased reactivity of the side facets, due to less surface passivation of cetyltrimethylammonium bromide. The similar synthetic strategy has also been demonstrated to be successful for the Pd-tipped Au nanorods that have not been reported before, indicating the great potential of this selective etching. The Ag-tipped Au nanorods are examined as a catalyst for the reduction of p-nitrophenol at room temperature. The Ag-tipped Au nanorods exhibit a higher catalytic activity than Au nanorods and core-shell Au@Ag nanorods, which could be attributed to the electronic effect and the unique structure in the Ag-tipped Au nanorods. © 2012 American Chemical Society.

Chao W.,Peking University | Zheng Y.-J.,Shandong University | Zheng Y.-J.,Beijing University of Technology
Journal of High Energy Physics | Year: 2013

Inspired by the indication of a relatively large θ 13 from accelerator and reactor neutrino oscillation experiments, we provide a systematic study of general modifications to the three well-studied neutrino mixing patterns, i.e., tri-bimaximal, bimaximal and democratic lepton mixing matrices. The correlation between θ 13 and the other two neutrino mixing angles are derived for each types of additional rotations. Predictions on θ 12 and θ 23 are also studied. Our study shows that, although some types of additional rotations are already excluded by the current global fit data of neutrino mixing angles, several types of additional rotations still survive. Our results may provide a guideline for the model building in neutrino physics. © 2013 SISSA, Trieste, Italy.

Ji F.,Soochow University of China | Ji F.,University of California at Davis | Li Z.,University of California at Davis | Nguyen H.,University of California at Davis | And 6 more authors.
Circulation | Year: 2013

Background-Cardiac surgery is associated with a high risk of cardiovascular and other complications that translate into increased mortality and healthcare costs. This retrospective study was designed to determine whether the perioperative use of dexmedetomidine could reduce the incidence of complications and mortality after cardiac surgery. Methods and Results-A total of 1134 patients who underwent coronary artery bypass surgery and coronary artery bypass surgery plus valvular or other procedures were included. Of them, 568 received intravenous dexmedetomidine infusion and 566 did not. Data were adjusted with propensity scores, and multivariate logistic regression was used. The primary outcomes measured included mortality and postoperative major adverse cardiocerebral events (stroke, coma, perioperative myocardial infarction, heart block, or cardiac arrest). Secondary outcomes included renal failure, sepsis, delirium, postoperative ventilation hours, length of hospital stay, and 30-day readmission. Dexmedetomidine use significantly reduced postoperative in-hospital (1.23% versus 4.59%; adjusted odds ratio, 0.34; 95% confidence interval, 0.192-0.614; P>0.0001), 30-day (1.76% versus 5.12%; adjusted odds ratio, 0.39; 95% confidence interval, 0.226-0.655; P>0.0001), and 1-year (3.17% versus 7.95%; adjusted odds ratio, 0.47; 95% confidence interval, 0.312-0.701; P=0.0002) mortality. Perioperative dexmedetomidine therapy also reduced the risk of overall complications (47.18% versus 54.06%; adjusted odds ratio, 0.80; 95% confidence interval, 0.68-0.96; P=0.0136) and delirium (5.46% versus 7.42%; adjusted odds ratio, 0.53; 95% confidence interval, 0.37-0.75; P=0.0030). Conclusion-Perioperative dexmedetomidine use was associated with a decrease in postoperative mortality up to 1 year and decreased incidence of postoperative complications and delirium in patients undergoing cardiac surgery. Copyright © 2013 American Heart Association, Inc.

Xu G.F.,Shandong University | Zhang J.,Shandong University | Tong D.M.,Shandong University | Sjoqvist E.,Uppsala University | And 2 more authors.
Physical Review Letters | Year: 2012

Quantum computation that combines the coherence stabilization virtues of decoherence-free subspaces and the fault tolerance of geometric holonomic control is of great practical importance. Some schemes of adiabatic holonomic quantum computation in decoherence-free subspaces have been proposed in the past few years. However, nonadiabatic holonomic quantum computation in decoherence-free subspaces, which avoids a long run-time requirement but with all the robust advantages, remains an open problem. Here, we demonstrate how to realize nonadiabatic holonomic quantum computation in decoherence-free subspaces. By using only three neighboring physical qubits undergoing collective dephasing to encode one logical qubit, we realize a universal set of quantum gates. © 2012 American Physical Society.

Tian Z.,Hefei University of Technology | Gershwin M.E.,University of California at Davis | Zhang C.,Shandong University
Journal of Autoimmunity | Year: 2012

As major components of innate immunity, NK cells not only exert cell-mediated cytotoxicity against tumor cells or infected cells, but also act to regulate the function of other immune cells by secretion of cytokines and chemokines, thus providing surveillance in early defense against viruses, intracellular bacteria and cancer cells. However, the effector function of NK cells must be exquisitely controlled in order to prevent inadvertent attack against self normal cells. The activity of NK cells is defined by integration of signals coming from inhibitory and activation receptors. Inhibitory receptors not only distinguish healthy from diseased cells by recognize self-MHC class I molecules on cell surfaces with "missing-self" model, but also provide an educational signal that generates functional NK cells. NK cells enrich in immunotolerance organ and recent findings of different regulatory NK cell subsets have indicated the unique role of NK cells in maintenance of homeostasis. Once the self-tolerance is broken, autoimmune response may occur. Although data has demonstrated that NK cells play important role in autoimmune disorders, NK cells seemed to act as a two edged weapon and play opposite roles with both regulatory and inducer activity even in the same disease. The precise role and regulatory mechanisms need to be further determined. In this review, we focus on recent research on the association of NK cells and antoimmune diseases, particularly the genetic correlation, the immune tolerance and misrecognition of NK cells, the regulatory function of NK cells, and their potential role in autoimmunity. © 2012 Elsevier Ltd.

Tang Y.,Nanyang Technological University | Loh P.C.,Nanyang Technological University | Wang P.,Nanyang Technological University | Choo F.H.,Nanyang Technological University | And 2 more authors.
IEEE Transactions on Industrial Electronics | Year: 2012

This paper concentrates on the design, control, and implementation of an LCL-filter-based shunt active power filter (SAPF), which can effectively compensate for harmonic currents produced by nonlinear loads in a three-phase three-wire power system. With an LCL filter added at its output, the proposed SAPF offers superior switching harmonic suppression using much reduced passive filtering elements. Its output currents thus have high slew rate for tracking the targeted reference closely. Smaller inductance of the LCL filter also means smaller harmonic voltage drop across the passive output filter, which in turn minimizes the possibility of overmodulation, particularly for cases where high modulation index is desired. These advantages, together with overall system stability, are guaranteed only through proper consideration of critical design and control issues, like the selection of LCL parameters, interactions between resonance damping and harmonic compensation, bandwidth design of the closed-loop system, and active damping implementation with fewer current sensors. These described design concerns, together with their generalized design procedure, are applied to an analytical example, and eventually verified by both simulation and experimental results. © 2011 IEEE.

Bi Y.,Shandong Qianfoshan Hospital | Zhang Q.,Shandong University | Pan F.,Shandong University
Respirology | Year: 2013

Background and objective: There has been increasing recognition that obstructive sleep apnoea (OSA) is associated with incident type 2 diabetes. The aim of this study was to assess the association between the severity of OSA and the risk of type 2 diabetes by performing a meta-analysis of all available prospective cohort studies. Methods: A search was conducted of the PubMed, EMBASE, CINAHL and ISI Web of Knowledge databases through March 2012 to identify studies linking OSA with the risk of diabetes. Only prospective cohort studies, in which the presence of OSA was confirmed by objective measurements, were included. Fixed and random effects models were used to calculate pooled relative risks (RR). Results: This meta-analysis of six prospective cohort studies including a total of 5953 participants, with follow-up periods of 2.7-16 years, and 332 incident cases of type 2 diabetes, showed that moderate-severe OSA was associated with a greater risk of diabetes (RR 1.63; 95% confidence interval (CI): 1.09-2.45), as compared with the absence of OSA. Sensitivity analyses yielded similar results. For subjects with mild OSA, as compared with those without OSA, the pooled RR of developing type 2 diabetes was 1.22 (95% CI: 0.91-1.63). Conclusions: This meta-analysis indicates that moderate-severe OSA is associated with an increased risk of type 2 diabetes, and this appears to be an independent risk factor for the development of diabetes. © 2012 The Authors. Respirology © 2012 Asian Pacific Society of Respirology.

Wang S.,Shandong University | Wang S.,Peking University | Tan W.,Peking University
International Journal of Heat and Fluid Flow | Year: 2011

Stability analysis of double-diffusive convection for viscoelastic fluid with Soret effect in a porous medium is investigated using a modified-Maxwell-Darcy model. We use the linear stability analysis to investigate how the Soret parameter and the relaxation time of viscoelastic fluid effect the onset of convection and the selection of an unstable wavenumber. It is found that the Soret effect is to destabilize the system for oscillatory convection. The relaxation time also enhances the instability of the system. The effects of Soret coefficient and relaxation time on the heat transfer rate in a porous medium are studied using the nonlinear stability analysis, the variation of the Nusselt number with respect to the Rayleigh number is derived for stationary and oscillatory convection modes. Some previous results can be reduced as the special cases of the present paper. © 2010 Elsevier Inc.

Kang Q.,Shanghai JiaoTong University | Shen Y.,Shandong University | Bai L.,Shanghai JiaoTong University
Natural Product Reports | Year: 2012

Covering: 1957 to 2011 3-Amino-5-hydroxy benzoic acid (3,5-AHBA) is a precursor for a large group of natural products, including the family of naphthalenic and benzenic ansamycins, the unique saliniketals, and the family of mitomycins. This review covers the biosynthesis of AHBA-derived natural products from a molecular genetics, chemical, and biochemical perspectives, and 174 references are cited. © 2012 The Royal Society of Chemistry.

Zhang H.,Shandong University | Song X.,Shandong Normal University | Song X.,Shandong Provincial Key Laboratory for Novel Distributed Computer Software Technology | Shi L.,Hong Kong University of Science and Technology
IEEE Transactions on Automatic Control | Year: 2012

We consider remote state estimation over a packet-dropping network. A new suboptimal filter is derived by minimizing the mean squared estimation error. The estimator is designed by solving one deterministic Riccati equation. Convergence of the estimation error covariance and mean square stability of the estimator are proved under standard assumptions. It is shown that the new estimator has smaller error covariance and has wider applications when compared with the linear minimum mean squared error estimator. One of the key techniques adopted in this technical note is the introduction of the innovation sequence for the multiplicative noise systems. © 2012 IEEE.

Ji L.,Shandong University | Huang Z.,Shanghai JiaoTong University
Journal of Sound and Vibration | Year: 2013

The paper concerns the analysis of subsystem randomness effects on the mid-frequency vibration responses of built-up systems. The system model considered, in the first instance, is a long-wavelength finite element (FE) subsystem connected with a short-wavelength statistical energy analysis (SEA) subsystem via discrete couplings. The randomness effects of the SEA subsystem on both the displacement response of the FE subsystem and the energy response of the SEA subsystem are then investigated under the frame of the hybrid FE/SEA theory [P. Shorter, R. Langley, Vibro-acoustic analysis of complex systems, Journal of Sound and Vibration, 288 (2005) 669-700]. It is found that the subsystem randomness effects may be well indicated by a dimensionless parameter α, which is a function of the number of coupling points, the dynamic mismatch between the FE and SEA subsystems and the modal overlap factor of the SEA subsystem. The smaller the value of α is, the more insignificant the randomness effects are. As a result, a so-called α-criterion is derived which states that, if a built-up structure satisfies the condition of α≪1, the randomness effects of the SEA subsystem can be neglected. In this case, the SEA subsystem can be simply treated as an infinite (or semi-infinite as appropriate) structure regardless of its mode count being sufficiently high or not. Numerical examples are presented to illustrate the validity of the present theory. © 2013 Elsevier Ltd.

Xi B.,Shandong University | He D.,Shandong University | Zhang M.,Shandong University | Xue J.,Shandong University | Zhou D.,Linyi Peoples Hospital
Sleep Medicine Reviews | Year: 2014

Sleep duration has been suggested to play a key role in the development of metabolic syndrome (MS). However, the results have been inconsistent. The objective of this study was to clarify the association between sleep duration and MS risk. PubMed and Embase databases were searched for eligible publications. Pooled odds ratio (OR) with 95% confidence interval (CI) was calculated using random- or fixed-model. A total of 12 studies (18,720 MS cases and 70,833 controls) were included in the meta-analysis. Short sleep duration was significantly associated with increased risk of MS (OR=1.27, 95%CI=1.09-1.47, p=0.002). Long sleep duration was not associated with increased risk of MS (OR=1.07, 95%CI=0.87-1.32, p=0.535). Similar results were found in both men and women. The sensitivity analysis confirmed the stability of the results and no publication bias was detected. The present meta-analysis suggests that short rather than long sleep duration is significantly associated with risk of MS. Large-scale well-design prospective studies are required to further investigate the association between sleep duration and MS risk. © 2013 Elsevier Ltd.

Deng Y.,Miami University Ohio | Liu L.,Miami University Ohio | Sarkisian R.G.,Miami University Ohio | Wheeler K.,Eastern Illinois University | And 2 more authors.
Angewandte Chemie - International Edition | Year: 2013

Powerful combination: Arylamines and metal Lewis acids are used as catalysts in the highly chemo- and enantioselective three-component inverse-electron-demand aza-Diels-Alder reaction of cyclic ketones with enones. The enantioselectivity is introduced by a simple chiral anion (see scheme). Arylamines can also serve as effective enamine catalysts in combination with either a metal Lewis acid or a Brønsted acid. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Gao J.-H.,Shandong University | Wang Q.,The Interdisciplinary Center | Wang Q.,Brookhaven National Laboratory
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics | Year: 2015

We demonstrate the emergence of the magnetic moment and spin-vorticity coupling of chiral fermions in 4-dimensional Wigner functions. In linear response theory with space-time varying electromagnetic fields, the parity-odd part of the electric conductivity can also be derived which reproduces results of the one-loop and the hard-thermal or hard-dense loop. All these properties show that the 4-dimensional Wigner functions capture comprehensive aspects of physics for chiral fermions in electromagnetic fields. © 2015.

Qin Y.,Shandong University | Jiao X.,Shandong University | Simpson J.L.,Research and Global Programs March of Dimes Foundation | Simpson J.L.,Florida International University | And 2 more authors.
Human Reproduction Update | Year: 2015

BACKGROUND: Primary ovarian insufficiency (POI) is characterized by marked heterogeneity, but with a significant genetic contribution. Identifying exact causative genes has been challenging, with many discoveries not replicated. It is timely to take stock of the field, outlining the progress made, framing the controversies and anticipating future directions in elucidating the genetics of POI. METHODS: A search for original articles published up to May 2015 was performed using PubMed and Google Scholar, identifying studies on the genetic etiology of POI. Studies were included if chromosomal analysis, candidate gene screening and a genome-wide study were conducted. Articles identified were restricted to English language full-text papers. RESULTS: Chromosomal abnormalities have long been recognized as a frequent cause of POI, with a currently estimated prevalence of 10-13%. Using the traditional karyotype methodology, monosomy X, mosaicism, X chromosome deletions and rearrangements, X-autosome translocations, and isochromosomes have been detected. Based on candidate gene studies, single gene perturbations unequivocally having a deleterious effect in at least one population include Bone morphogenetic protein 15 (BMP15), Progesterone receptor membrane component 1 (PGRMC1), and Fragile X mental retardation 1 (FMR1) premutation on the X chromosome; Growth differentiation factor 9 (GDF9), Folliculogenesis specific bHLH transcription factor (FIGLA), Newborn ovary homeobox gene (NOBOX), Nuclear receptor subfamily 5, group A, member 1 (NR5A1) and Nanos homolog 3 (NANOS3) seem likely as well, but mostly being found in no more than 1-2% of a single population studied. Whole genome approaches have utilized genome-wide association studies (GWAS) to reveal loci not predicted on the basis of a candidate gene, but it remains difficult to locate causative genes and susceptible loci were not always replicated. Cytogenomic methods (array CGH) have identified other regions of interest but studies have not shown consistent results, the resolution of arrays has varied and replication is uncommon. Whole-exome sequencing in non-syndromic POI kindreds has only recently begun, revealing mutations in the Stromal antigen 3 (STAG3), Synaptonemal complex central element 1 (SYCE1), minichromosome maintenance complex component 8 and 9 (MCM8, MCM9) and ATP-dependent DNA helicase homolog (HFM1) genes. Given the slow progress in candidate-gene analysis and relatively small sample sizes available for GWAS, family-based whole exome and whole genome sequencing appear to be the most promising approaches for detecting potential genes responsible for POI. CONCLUSION: Taken together, the cytogenetic, cytogenomic (array CGH) and exome sequencing approaches have revealed a genetic causation in ~20-25% of POI cases. Uncovering the remainder of the causative genes will be facilitated not only by whole genome approaches involving larger cohorts in multiple populations but also incorporating environmental exposures and exploring signaling pathways in intragenic and intergenic regions that point to perturbations in regulatory genes and networks. © The Author 2015. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology.

Qin F.,Jiangxi Normal University | Qin F.,Nanchang Hangkong University | Baczynski M.,University of Silesia | Xie A.,Shandong University
IEEE Transactions on Fuzzy Systems | Year: 2012

In order to avoid combinatorial rule explosion in fuzzy reasoning, in this paper, we explore the distributive equations of implications. In detail, by means of the sections of I, we give out the sufficient and necessary conditions of solutions for the distributive equation of implication I(x,T 1(y,z))=T 2(I(x,y),I(x,z)), when T 1 is a continuous but not Archimedean triangular norm, T 2 is a continuous and Archimedean triangular norm, and I is an unknown function. This obtained characterizations indicate that there are no continuous solutions for the previous functional equation, satisfying the boundary conditions of implications. However, under the assumptions that I is continuous except for the point (0,0), we get its complete characterizations. Here, it should be pointed out that these results make differences with recent results that are obtained by Baczyski and Qin. Moreover, our method can still apply to the three other functional equations that are related closely to the distributive equation of implication. © 2012 IEEE.

Zhang C.,Shandong University | Zeng L.,King's College London | Emanueli C.,Royal Infirmary | Xu Q.,King's College London
Cardiovascular Research | Year: 2013

It is well known that the altered blood flow is related to vascular diseases, including atherosclerosis, restenosis, and arteriosclerosis, which preferentially located at areas with the disturbed blood flow, suggesting that altered biomechanical stress may exert their effect on the vascular disease. Recent evidence indicated the presence of abundant stem/progenitor cells in the vessel wall, in which laminar shear stress can stimulate these cells to differentiate towards endothelial lineage, while cyclic strain results in smooth muscle differentiation. In line with this, it was evidenced that altered biomechanical stress in stented vessels may lead to 'wrong' direction of vascular stem cell differentiation resulting in restenosis. However, the underlying mechanisms are not well understood. In this article, we will give an overview of the effect of the local flow pattern on stem/progenitor cell differentiation and the possible mechanism on how the blood flow influences stem cell behaviours in the development of vascular diseases. © The Author 2013.

Ma Y.,Jacobs University Bremen | Ma Y.,Shandong University | Dai Y.,Shandong University | Kou L.,University of Bremen | And 2 more authors.
Nano Letters | Year: 2015

One of the major obstacles to a wide application range of the quantum spin Hall (QSH) effect is the lack of suitable QSH insulators with a large bulk gap. By means of first-principles calculations including relativistic effects, we predict that methyl-functionalized bismuth, antimony, and lead bilayers (Me-Bi, Me-Sb, and Me-Pb) are 2D topological insulators (TIs) with protected Dirac type topological helical edge states, and thus suitable QSH systems. In addition to the explicitly obtained topological edge states, the nontrivial topological characteristic of these systems is confirmed by the calculated nontrivial Z2 topological invariant. The TI characteristics are intrinsic to the studied materials and are not subject to lateral quantum confinement at edges, as confirmed by explicit simulation of the corresponding nanoribbons. It is worthwhile to point out that the large nontrivial bulk gaps of 0.934 eV (Me-Bi), 0.386 eV (Me-Sb), and 0.964 eV (Me-Pb) are derived from the strong spin-orbit coupling within the px and py orbitals and would be large enough for room-temperature application. Moreover, we show that the topological properties in these three systems are robust against mechanical deformation. These novel 2D TIs with such giant topological energy gaps are promising platforms for topological phenomena and possible applications at high temperature. © 2015 American Chemical Society.

Gao C.,Shandong University | Gao C.,Shanghai JiaoTong University | Ma C.,Shandong University | Xu P.,Shanghai JiaoTong University
Biotechnology Advances | Year: 2011

Lactic acid, the most important hydroxycarboxylic acid, is now commercially produced by the fermentation of sugars present in biomass. In addition to its use in the synthesis of biodegradable polymers, lactic acid can be regarded as a feedstock for the green chemistry of the future. Different potentially useful chemicals such as pyruvic acid, acrylic acid, 1,2-propanediol, and lactate ester can be produced from lactic acid via chemical and biotechnological routes. Here, we reviewed the current status of the production of potentially valuable chemicals from lactic acid via biotechnological routes. Although some of the reactions described in this review article are still not applicable at current stage, due to their "greener" properties, biotechnological processes for the production of lactic acid derivatives might replace the chemical routes in the future. © 2011 Elsevier Inc.

Liu H.,Shandong University | Jia Y.,Shandong University | De Aldana J.R.V.,University of Salamanca | Jaque D.,Autonomous University of Madrid | Chen F.,Shandong University
Optics Express | Year: 2012

We report on the fabrication of depressed cladding waveguide lasers in Nd:YAG (neodymium doped yttrium aluminum garnet, Nd:Y3Al5O12) ceramics microstructured by femtosecond laser pulses. Full control over the confined light spatial distribution is demonstrated by the fabrication of high contrast waveguides with hexagonalcircular and trapezoidal configurations. The confocal fluorescence measurements of the waveguides reveal that the original luminescence features of Nd3+ ions are well-preserved in the waveguide regions. Under optical pump at 808 nm, cladding waveguides showed continuous wave efficient laser oscillation. The maximum output power obtained at 1064.5 nm is ∼181 mW with a slope efficiency as high as 44%which suggests that the fabricated Nd:YAG ceramic waveguides are promising candidates for efficient integrated laser sources. © 2012 Optical Society of America.

Agency: European Commission | Branch: FP7 | Program: CP-SICA | Phase: HEALTH-2007-3.5-2 | Award Amount: 3.85M | Year: 2009

In much of Asia, households are liable for large out-of-pocket payments when they use health services. As a result, many fail to seek care or get inadequate care, while others seek care but end up in financial difficulty. Expanding insurance is one obvious policy solution, but private and community-based insurance schemes have rarely been successful, and social insurance schemes have struggled with the problem of covering the informal sector and the poor; some countries as a result have resorted to a predominantly tax-financed health system. But demand-side factors are only one part of the problem. The cost of health care itself is often unnecessarily high because of weak supply-side incentives. Limited controls on provider prices and type of care delivered can mean that the insured simply end up with higher-priced care. A first strand of the project examines how, in six Asian countries (Cambodia, China, Indonesia, the Philippines, Thailand, and Vietnam), price and other barriers impede use of health care, and result in inequalities in use. It also looks at how households cope with health shocks, and whether they are able to prevent health expenditures and income losses associated with illness from causing sudden and potentially impoverishing drops in consumption. A second strand evaluates the impact of a variety of programs that aim at promoting health care use (especially among the poor), enhance quality and contain costs, and hence help ensure that households are protected from the financial consequences of health shocks. The project builds on successful previous collaborations, but has several innovative features: a focus on the causes of inequity and lack of financial protection, and the impact of programs on both; a mix of cross-country comparative work and in-depth country-specific work; a mix of academic researchers and policy analysts; and an equal emphasis on dissemination to researchers, policymakers and the international development community.

Xi B.,Shandong University | He D.,Shandong University | Hu Y.,National Center for Public Health Surveillance and Information Services | Zhou D.,Linyi Peoples Hospital
Preventive Medicine | Year: 2013

Objective: We aimed to estimate the up-to-date prevalence of metabolic syndrome (MS) and its influencing factors among the Chinese adults. Methods: Data were obtained from the China Health and Nutrition Survey conducted in 2009, which was a cross-sectional and partially nationally representative study including a total of 7488 Chinese adults (age. ≥ 18. years). Results: The overall age-standardized prevalence estimates of the MS were 21.3% (95%confidence interval (CI): 20.4%-22.2%), 18.2% (95%CI: 17.3%-19.1%) and 10.5% (95%CI: 9.8%-11.2%) based on definitions of revised NCEP ATPIII, IDF and CDS criteria, respectively. Individuals who were women (compared to men: odds ratio [OR] = 1.37, 95% CI = 1.16-1.61), 40. years or older (compared to less than 40. years old: OR = 2.82, 95%CI = 2.37-3.34 for 40-59. years; OR = 4.41, 95%CI = 3.68-5.29 for 60. years or older), overweight/obese (compared to normal weight: OR = 4.32, 95%CI = 3.77-4.95 for overweight; OR = 11.24, 95%CI = 9.53-13.26 for obese), and living in urban area (compared to living in rural area: OR = 1.27, 95%CI = 1.12-1.43) were more likely to have a higher prevalence estimate of MS. In addition, frequency of alcohol consumption and cigarette intake were also found to be significantly associated with probability of MS. Conclusions: Our results suggest an urgent need to develop national strategies for the prevention, detection, treatment and control of obesity and MS in China. © 2013 Elsevier Inc.

News Article | August 22, 2016
Site: news.mit.edu

Laptop computer users operating their devices on their laps will be familiar with the heat they generate, which comes from electrical resistance converting waste energy to heat. Scientists dream of creating electronic devices with little or no resistance to the flow of electricity, in order to reduce heat output, save energy, and extend device capabilities. In the last several years theorists and experimentalists have been trying to achieve this goal using extremely thin materials with special physical properties, called topological insulators (TIs). Recently there has been a breakthrough towards this goal: Dissipationless flow of current has been achieved in TIs when it enters a quantum state without any external magnetic fields — although, as of now, only at extremely low temperatures, its potential can be significant if the operating temperature could be raised. Topological insulators allow the free flow of electrons only on their surface while blocking the flow of electrons through their bulk. MIT postdoc Cui-Zu Chang, then a doctoral student at Tsinghua University in China, and colleagues at Chinese Academy of Sciences-Institute of Physics, Tsinghua, and Stanford University, reported the experimental demonstration of electrons flowing only along the edge of a topological insulator film circuit, driven by an internal magnetic field, which physicists call the quantum anomalous Hall effect. To provide internal magnetism for their circuit, they added chromium to their material, which was composed of bismuth, antimony, and tellurium. However, the Tsinghua system still showed remnants of electrical resistance to the edge current, frustratingly close to zero resistance. Improving upon his earlier work, Chang and colleagues in the group of Jagadeesh Moodera, along with collaborators from Penn State, Stanford and Northeastern University, achieved robust quantum anomalous Hall state and near dissipationless electron transport in topological insulators. Chang and colleagues at MIT replaced chromium with vanadium to obtain atomically thin layers of their magnetic topological insulators. They stacked sample films of this material on a base of strontium titanate. They reported early results of this work in Nature Materials in May 2015, achieving very slight resistance to current flowing lengthwise along their sample. Via local and nonlocal measurements, Chang and colleagues at MIT and Penn State University with further optimization achieved zero resistance to current flowing lengthwise along the edge of their sample circuit at the extremely low temperature of 25 millikelvins (0.025 kelvins), a state physicists call “dissipationless chiral edge transport.” This lack of resistance is independent of length, they say in a Physical Review Letters paper published in July 2015. Moodera’s group is part of the Francis Bitter Magnet Laboratory and MIT Department of Physics. “In this system, there is a very special edge channel,” Chang explains. “The bulk is insulating but the chiral edge channel is metallic and spin polarized, so it’s very useful for the next generation electronics and spintronics with low power consumption.” “A signal entering this system can propagate a long distance without losing any of its energy. While presently it can only be realized at very low temperatures, there are indications that this can be raised,” Chang says. Observing this kind of quantum anomalous Hall state below 1 kelvin requires a special piece of equipment called a cryostat, so work continues to produce this effect at a higher temperature. Adding an extra element such as chromium or vanadium to introduce a special property (such as magnetism) to a material is known as doping. The vanadium-doped system showed three distinct advantages over the chromium-doped system: • twofold increase in the temperature above which the material loses magnetism (its Curie temperature), allowing the vanadium system to operate at zero resistance at a slightly higher but still very cold temperature; • 10 times increase in the stability of its intrinsic magnetism (its coercive field); and • one-half reduction in its carrier density. The vanadium system spontaneously shows magnetism at below about 23 kelvins. Results show this quantum anomalous Hall state can survive in a vanadium-doped system up to 5 kelvins (-450 degrees Fahrenheit). However, above 5 kelvins, the effect disappears and the normal resistance of the bulk material appears. While their sample film is still extremely thin — about 4 nanometers — the device studied is about 1 mm long by 0.4 mm wide, which is relatively large compared with other studies of quantum spintronic phenomena. “We make this kind of sample so big to preserve the delicate properties of the film. These films are very sensitive to water and air, which degrades the film properties,” Chang explains. Chang worked for five years in his doctoral studies at Tsinghua University searching for the quantum anomalous Hall effect, which was predicted in 1988 by F. Duncan M. Haldane at Princeton, he notes. “In a recent theoretical paper, no quantum anomalous Hall effect was predicted in a vanadium-doped topological insulator, whereas we experimentally showed the opposite is true, that this system is better for observing quantum anomalous Hall effect!” Chang says. The 2006 discovery of topological insulators made the realization of quantum anomalous Hall effect practical. Chang cites three conditions to realize this effect: atomically flat thin TI film; introducing magnetism into the TI film; and tuning the chemical potential (Fermi level) into the gap induced by magnetism. After an intense search, Chang first observed the quantum anomalous Hall state in Oct. 9, 2012, in a sample of chromium-doped bismuth antimony, simultaneously showing a noticeable decrease in longitudinal resistance, according to a report on the evolution of their work published Feb. 26 in the Journal of Physics: Condensed Matter. Separately, a group at Tokyo University which included Joseph Checkelsky, now assistant professor of physics at MIT, confirmed the Tsinghua work and also observed the quantum anomalous Hall effect in the same system, Chang says. “If you can realize this effect at room temperature, it will significantly change our life. You can use this kind of effect to develop quantum electronics including the quantum computer,” Chang says. “In this kind of computer, there is minimal heating effect; the current flow is completely dissipationless; and you can also communicate over very long distance.” Although a superconductor can also reach zero resistance at low temperature, it is not spin-polarized, so it can transfer only electrical information but not spin information, Chang explains. The advantage of the quantum anomalous Hall effect, or topological edge state, is that the edge current is spin-polarized and robust, so it can be used to transfer information. Chang, 30, is originally from the Chinese kite-making city of Weifang, in Shandong province. He received his bachelor’s in optical engineering at Shandong University in China and doctorate in physics at Tsinghua University. His wife, Jia Song, has a PhD in mathematics from Tsinghua University. Chang’s work is supported by the Center for Integrated Quantum Materials under NSF grant DMR-1231319. A third-year postdoc in the Moodera group, he is looking for a faculty position in the fall.

Li A.,Shandong University | Lin B.,Minjiang University | Lin B.,Xiamen University
Energy Policy | Year: 2013

Currently, China is the largest carbon emitter mainly due to growing consumption of fossil fuels. In 2009, the Chinese government committed itself to reducing domestic carbon emissions per unit of GDP by 40-45% by 2020 compared to 2005 levels. Therefore, it is a top priority for the Chinese government to adopt efficient policy instruments to reduce its carbon intensity. Against this background, this paper develops a general equilibrium model and seeks to provide empirical contributions by comparing the potential impacts of several different policy options to reduce China's carbon emissions. The main findings are as follows. Firstly, these climate policies would affect the structure of economy and contribute to carbon emissions reduction and carbon intensity reduction. Secondly, there would be significant differences in the economic and environmental effects among different climate policies and hence, the government would trade-off among different economic objectives to overcome any potential resistances. Thirdly, there would be considerable differences in the emissions effects of absolute and intensity-based carbon emissions controls, implying that the government might adopt different climate policies for absolute or intensity-based carbon emissions controls. Looking ahead, the government should trade-off among different objectives when designing climate reforms. © 2013 Elsevier Ltd.

Zhao M.,Shandong University | Zhang R.,Beijing Computational Science Research Center | Zhang R.,City University of Hong Kong
Physical Review B - Condensed Matter and Materials Physics | Year: 2014

Silicon carbide and other group-IV binary materials with 1:1 stoichiometry are trivial semiconductors. Using first-principles calculations combined with a tight-binding model, we demonstrate two-dimensional (2D) silicon carbide materials (siligraphenes) with 1:3 and 3:1 stoichiometries are topological insulators (TIs) superior to graphene. Dirac cones and topologically nontrivial electronic structures are predicted in these binary honeycomb lattices. The band gaps opened at the Dirac points due to the spin-orbital coupling (SOC) are several orders of magnitude larger than the graphene value. Such interesting properties also exist in their analogs of other group-IV elements, such as g-GeC3, g-Ge3C, g-GeSi3, and g-Ge3Si. The TI states predicted in these unique lattices broaden the application field of group-IV binary materials and open the door to searching for 2D TIs with enhanced SOC. © 2014 American Physical Society.

Zhang C.,Chinese Academy of Sciences | Bai M.-Y.,Shandong University | Chong K.,CAS Institute of Botany
Plant Cell Reports | Year: 2014

Key message: Brassinosteroids have important roles in plant development. This review focuses on the agronomic traits regulated by brassinosteroids in rice. Abstract: Brassinosteroids (BRs) are a group of steroid phytohormones with wide-ranging biological activity. Genetic, genomic and proteomic studies have greatly advanced our understanding of BR signaling in Arabidopsis and revealed a connected signal transduction pathway from the cell surface receptor kinase BRASSINOSTEROID-INSENSITIVE1 (BRI1) and BRI1-ASSOCIATED RECEPTOR KINASE 1 (BAK1) to the BRASSINAZOLE-RESISTANT1 (BZR1) family of transcription factors and their targets mediating physiological functions. However, compared with the dicot model plant Arabidopsis, much less is known about BR signaling in rice, which is a monocot. In this review, we provide an update on the progress made by BR studies in rice and discuss how BR regulates various important agronomic traits to determine rice grain yield. Specifically, we discuss the function of novel components including LEAF AND TILLER ANGLE INCREASED CONTROLLER (LIC), DWARF and LOW-TILLERING (DLT), DWARF1 (D1) and TAIHU DWARF1 (TUD1) in rice BR signaling, and provide a rice BR-signaling pathway model that involves a BRI1-dependent pathway as well as a G-protein α subunit-mediated signaling pathway. The recent significant advances in our understanding of BR-mediated molecular mechanisms underlying agronomic traits will be of great help for rice molecular breeding. © 2014, The Author(s).

Zheng X.-X.,Peking Union Medical College | Xu Y.-L.,Peking Union Medical College | Li S.-H.,Shandong University | Hui R.,Peking Union Medical College | And 2 more authors.
American Journal of Clinical Nutrition | Year: 2013

Background: The effect of green tea catechins (GTCs) with or without caffeine on glycemic control is controversial. Objective: We aimed to identify and quantify the effects of GTCs or GTC-caffeine mixtures on glucose metabolism in adults. Design: A comprehensive literature search was conducted to identify relevant trials of GTCs with or without caffeine on markers of glycemic control [fasting blood glucose (FBG), fasting blood insulin (FBI), glycated hemoglobin (Hb A1c), and homeostatic model assessment of insulin resistance (HOMA-IR)]. Weighted mean differences were calculated for net changes by using fixed-effects models. Prespecified subgroup analyses were performed to explore the influence of covariates on net changes in FBG and FBI concentrations. Results: Twenty-two eligible randomized controlled trials with 1584 subjects were identified. Pooled analyses showed that FBG (-1.48 mg/dL; 95% CI: -2.57, -0.40 mg/dL) decreased significantly with GTCs with or without caffeine, whereas FBI (0.04 μU/mL; 95% CI: 20.36, 0.45 μU/mL), Hb A1c (20.04%; 95% CI: 20.15, 0.08%), and HOMA-IR (20.05; 95% CI: 20.37, 0.26) did not. Subgroup analyses indicated that the glucose-lowering effect was apparent when the duration of follow-up was over a median of 12 wk. Overall, no significant heterogeneity was detected for FBG, FBI, Hb A1c, or HOMA-IR. Conclusions: The meta-analysis showed that the administration of GTCs with or without caffeine resulted in a significant reduction in FBG. The limited data available on GTCs did not support a positive effect on FBI, Hb A1c, or HOMA-IR. Thus, more large and welldesigned trials are needed in the future. This trial was registered at http://www.crd.york.ac.uk/prospero as CRD42012002139. Copyright © 2013 American Society for Nutrition.

Song D.-G.,University of Pennsylvania | Song D.-G.,Shandong University | Ye Q.,University of Pennsylvania | Poussin M.,University of Pennsylvania | And 3 more authors.
Blood | Year: 2012

The costimulatory effects of CD27 on T lymphocyte effector function and memory formation has been confined to evaluations in mouse models, in vitro human cell culture systems, and clinical observations. Here, we tested whether CD27 costimulation actively enhances human T-cell function, expansion, and survival in vitro and in vivo. Human T cells transduced to express an antigen-specific chimeric antigen receptor (CAR-T) containing an intracellular CD3 zeta (CD3ζ) chain signaling module with the CD27 costimulatory motif in tandem exerted increased antigen-stimulated effector functions in vitro, including cytokine secretion and cytotoxicity, compared with CAR-T with CD3ζ alone. After antigen stimulation in vitro, CD27-bearing CAR-T cells also proliferated, upregulated Bcl-X L protein expression, resisted apoptosis, and underwent increased numerical expansion. The greatest impact of CD27 was noted in vivo, where transferred CAR-T cells with CD27 demonstrated heightened persistence after infusion, facilitating improved regression of human cancer in a xenogeneic allograft model. This tumor regression was similar to that achieved with CD28- or 4-1BB-costimulated CARs, and heightened persistence was similar to 4-1BB but greater than CD28. Thus, CD27 costimulation enhances expansion, effector function, and survival of human CAR-T cells in vitro and augments human T-cell persistence and antitumor activity in vivo. © 2012 by The American Society of Hematology.

Shi L.,Hong Kong University of Science and Technology | Zhang H.,Shandong University
IEEE Transactions on Signal Processing | Year: 2012

We consider scheduling two Gauss-Markov systems. Two sensors, each measuring the state of one of the two systems, compute and report their local state estimates to a central remote estimator, respectively. Due to the bandwidth constraint, at each time, only one of the sensors is allowed to communicate its estimate with the remote estimator. Upon receiving the data from the sensors, the remote estimator computes the minimum mean squared error estimate of each system's state. We provide an explicit construction of an optimal schedule, which is periodic (hence allows simple and efficient practical implementation) and minimizes the sum of the average estimation error covariance of each system. © 2012 IEEE.

Baidas S.,Stevens Institute of Technology | Baidas S.,Kuwait Institute for Scientific Research | Gao B.,Shandong University | Meng X.,Stevens Institute of Technology
Journal of Hazardous Materials | Year: 2011

We report a kinetic and equilibrium study of perchlorate adsorption onto giant reed modified by quaternary amine (QA) functional groups in batch reactors. The effect of pH, contact time, and initial perchlorate concentration on removal was investigated. The adsorption capacity for perchlorate was 169. mg/g on the modified reed (MR) particles ranging in size from 100 to 250 μm. The isotherm results were best described by the combined Langmuir-Freundlich equation. Optimum removal occurred in the pH range 3.5-7.0 and was reduced at pH > 8.5. The maximum adsorption rate occurred within the first minute of contact and equilibrium was achieved within 7. min. A three-stage adsorption occurred. In stage 1, adsorption was rapid and was controlled by boundary layer diffusion. In stage 2, adsorption was gradual and was controlled by both boundary layer and intraparticle diffusion. In stage 3, adsorption reached a plateau. The kinetic results fit well with a pseudo second-order equation. The adsorption mechanism was explored using Zeta potential analysis and Raman spectroscopy. Zeta potential measurements showed that reed modification enhanced perchlorate removal by increasing the surface potential. Electrostatic attraction between perchlorate anion and positively charged quaternary amine groups on the MR was the primary mechanism responsible for perchlorate removal. © 2011 Elsevier B.V.

Ding Q.,Shandong University | Zhong M.,Beihang University
International Journal of Innovative Computing, Information and Control | Year: 2010

This paper deals with the problem of robust fault detection for Markovian jump linear systems with polytopic uncertainties. Using a generalized form of observer-based fault detection filter (FDF) as a residual generator, the design of robust FDF is formulated in the framework of stochastic H∞ filtering. Based on analyzing the robust mean square stability and stochastic H∞performance of the FDF, sufficient conditions on the existence of both mode-dependent and mode-independent H∞ FDFs are respectively derived and solutions to the H∞ FDFs are given in terms of linear matrix inequalities. A numerical example is given to show the effectiveness of the proposed method. ©2010 ISSN 1349-4198.

Yang Z.-J.,China Japan Friendship Hospital | Liu J.,Shanxi Province Peoples Hospital | Ge J.-P.,Xinjiang Uygur Autonomous Regions Hospital | Chen L.,Shandong University | And 2 more authors.
European Heart Journal | Year: 2012

Aims Cardiovascular disease (CVD) is now the most prevalent and debilitating disease affecting the Chinese population. The goal of the present manuscript was to analyse cardiovascular risk factors and the prevalence of non-fatal CVDs from data gathered from the 20072008 China National Diabetes and Metabolic Disorders Study. Methods and Results A nationally representative sample of 46 239 adults, 20 years of age or older, was randomly recruited using a multistage stratified design method. Lifestyle factors, diagnosis of CVD, stroke, diabetes, and family history of each subject were collected, and an oral glucose tolerance test or a standard meal test was performed. Various non-fatal CVDs were reported by the subjects. SUDAAN software was used to perform all weighted statistical analyses, with P < 0.05 considered statistically significant. The prevalence of coronary heart disease, stroke, and CVDs was 0.74, 1.07, and 1.78 in males; and 0.51, 0.60, and 1.10 in females, respectively. The presence of CVDs increased with age in both males and females. The prevalence of being overweight or obese, hypertension, dyslipidaemia, or hyperglycaemia was 36.67, 30.09, 67.43, and 26.69 in males; and 29.77, 24.79, 63.98, and 23.62 in females, respectively. In the total sample of 46 239 patients, the prevalence of one subject having 1, 2, 3, or <4 of the 5 defined risk factors (i.e. smoking, overweight or obese, hypertension, dyslipidaemia, or hyperglycaemia) was 31.17, 27.38, 17.76, and 10.19, respectively. Following adjustment for gender and age, the odds ratio of CVDs for those who had 1, 2, 3, or <4 risk factors was 2.36, 4.24, 4.88, and 7.22, respectively, when compared with patients with no risk factors. Conclusion Morbidity attributed to the five defined cardiovascular risk factors was high in the Chinese population, with multiple risk factors present in the same individual. Therefore, reasonable prevention strategies should be designed to attenuate the rapid rise in cardiovascular morbidity. © 2011 The Author.

Li F.,Shandong University | Zhu Y.-T.,Tissue Technology Inc.
Cellular Signalling | Year: 2015

COX-2 is a major regulator in colorectal inflammation and cancer. Herein, we first report that primary cancer-associated colonic fibroblasts activated by HGF play a critical role in mediation of proliferation and invasiveness of human colonic epithelial cancer cells. We have discovered that the proliferation and invasiveness of colonic epithelial cancer cells are predominantly enhanced through activation of PKC-cMET-ERK1/2-COX-2 signaling by HGF in the co-cultured cancer-associated fibroblasts. This conclusion is supported by the fact, that a selective PKC inhibitor, BIM, inhibits ERK1/2 and COX-2 signalings, MEK/ERK1/2 inhibitor, PD98059, nullifies COX-2 signaling, and COX-2 inhibitor, NS-398, attenuates the proliferation and invasiveness potential of the colonic cancer cells. We have concluded that HCF-activated cancer associated fibroblasts play a critical role in carcinogenesis of colonic cancer. © 2015 Elsevier Inc.

Li X.,Shandong University | Wu J.-F.,Jinan Public Security Bureau
Recent Patents on Anti-Cancer Drug Discovery | Year: 2010

Matrix metalloproteinases (MMPs) belong to a family of closely related calcium and zinc-dependent endopeptidases involved in the degradation and remodeling of extracellular matrix (ECM) proteins that are associated with the tumorigenic processes. MMPs promote tumor invasion and metastasis, regulating host defense mechanisms and normal cell function. Thus, MMP inhibitors (MMPIs) are expected to be useful chemotherapeutic agents for the treatment of malignant cancer, osteoarthritis, and rheumatoid arthritis. A vast number of small molecular MMPIs have been developed in recent years. Although there have been considerable preclinical and clinical studies on these inhibitors, most of the effective candidates in clinical trials, however, have yielded unsatisfactory results, thus they are as yet unavailable for use as therapeutic drugs. Currently, more efforts have been directed to the design of specific inhibitors towards certain MMP family members for selective usage. This review will focus primarily on an analysis of recent developed MMPIs that have entered preclinical or clinical trials, and recently registered patents with regard to new highly selective MMPIs in USA or patent applications related to the specific inhibitors of MMPs. We also analyze the clinical failure and discuss the possible strategies to best optimize the development of these novel agents. © 2010 Bentham Science Publishers Ltd.

Zhang L.,Peking Union Medical College | Gong D.,Peking Union Medical College | Li S.,Shandong University | Zhou X.,Peking Union Medical College
Atherosclerosis | Year: 2012

Background: Controversies exist among trials reporting the effects of statins on endothelial dysfunction in patients with diabetes mellitus (DM). Therefore, we performed a meta-analysis to determine whether statin therapy could improve endothelial dysfunction in patients with DM. Methods: PubMed, Cochrane and Embase were searched for randomized controlled trials of statins. Only trials reporting changes in flow-mediated dilatation (FMD) were included in this analysis. A meta-analysis was performed to assess the relationship between statin therapy and improvements in endothelial dysfunction. Meta-regression and subgroup analyses were done to identify sources of heterogeneity. Results: Ten statin studies (845 patients) were included in this analysis. Statin therapy significantly improved FMD in patients with DM [weighted mean difference (WMD): 0.94%; 95% CI: 0.38%, 1.5%; P<0.001]. Although heterogeneity among trials was found (I 2: 67%), no significant publication bias was detected. Subgroup analyses showed that patients did not benefit from statin therapy if their body mass index (BMI) was>27.6kg/m 2 (four trials; I 2: 0%; WMD: 0.11%; 95% CI: -0.47%, 0.70%; P=0.70). However, FMD was significantly improved among patients with BMI ≤27.6kg/m 2 (five trials; I 2: 14%; WMD: 1.52%; 95% CI: 1.19%, 1.85%; P<0.001). Type 1 diabetes, younger age, lower baseline blood lipid levels and blood pressure were all associated with improvements in FMD. The meta-regression analysis yielded similar results. Conclusion: Statins significantly improved the FMD only in patients with better endothelial functions. The use of FMD in evaluating therapeutic outcomes should be careful in populations at high risk. © 2012 Elsevier Ireland Ltd.

Wang H.,University of South Carolina | Tian H.,Shandong University | Tian H.,Beijing Computational Science Research Center
Computer Methods in Applied Mechanics and Engineering | Year: 2014

The peridynamic theory provides an appropriate description of the deformation of a continuous body involving discontinuities or other singularities, which cannot be described properly by the classical theory of solid mechanics. However, the operator in the peridynamic theory is nonlocal, so the resulting numerical methods generate dense or full coefficient matrices which require O(N2) of memory where N is the number of unknowns in the discretized system. Gaussian types of direct solvers, which were traditionally used to solve these problems, require O(N3) of operations. Furthermore, due to the singularity of the kernel in the peridynamic model, the evaluation and assembly of the coefficient matrix can be very expensive. Numerous numerical experiments have shown that in many practical simulations the evaluation and assembly of the coefficient matrix often constitute the main computational cost! The significantly increased computational work and memory requirement of the peridynamic model over those for the classical partial differential equation models severely limit their applications, especially in multiple space dimensions.We develop a fast and faithful collocation method for a two-dimensional nonlocal diffusion model, which can be viewed as a scalar-valued version of a peridynamic model, without using any lossy compression, but rather, by exploiting the structure of the coefficient matrix. The new method reduces the evaluation and assembly of the coefficient matrix by O(N), reduces the computational work from O(N3) required by the traditional methods to O(Nlog2N) and the memory requirement from O(N2) to O(N). Numerical results are presented to show the utility of the fast method. © 2014 Elsevier B.V.

Gus-Brautbar Y.,University of Pennsylvania | Johnson D.,University of Pennsylvania | Zhang L.,Shandong University | Sun H.,University of Pennsylvania | And 3 more authors.
Molecular Cell | Year: 2012

The connection between cancer and inflammation is widely recognized, yet the underlying molecular mechanisms are poorly understood. We report here that TIPE2 provides a molecular bridge from inflammation to cancer by targeting the Ras signaling pathway. TIPE2 binds the Ras-interacting domain of the RalGDS family of proteins, which are essential effectors of activated Ras. This binding prevented Ras from forming an active complex, thereby inhibiting the activation of the downstream signaling molecules Ral and AKT. Consequently, TIPE2 deficiency led to heightened activation of Ral and AKT, resistance to cell death, increased migration, and dysregulation of exocyst complex formation. Conversely, TIPE2 overexpression induced cell death and significantly inhibited Ras-induced tumorigenesis in mice. Importantly, TIPE2 expression was either completely lost or significantly downregulated in human hepatic cancer. Thus, TIPE2 is an inhibitor of both inflammation and cancer, and a potential drug target for inflammatory and neoplastic diseases. © 2012 Elsevier Inc.

Shi H.,Shandong Cancer Hospital and Institute | Sun M.,Shandong University | Liu L.,Shandong Cancer Hospital and Institute | Wang Z.,Shandong Cancer Hospital and Institute
Molecular Cancer | Year: 2014

Chimeric antigen receptors (CARs) are recombinant receptors that combine the specificity of an antigen-specific antibody with the T-cell's activating functions. Initial clinical trials of genetically engineered CAR T cells have significantly raised the profile of T cell therapy, and great efforts have been made to improve this approach. In this review, we provide a structural overview of the development of CAR technology and highlight areas that require further refinement. We also discuss critical issues related to CAR therapy, including the optimization of CAR T cells, the route of administration, CAR toxicity and the blocking of inhibitory molecules. © 2014 Shi et al.; licensee BioMed Central Ltd.

Meng X.,Shandong Cancer Hospital and Institute | Huang Z.,Shandong University | Teng F.,Shandong Cancer Hospital and Institute | Xing L.,Shandong Cancer Hospital and Institute | Yu J.,Shandong Cancer Hospital and Institute
Cancer Treatment Reviews | Year: 2015

Checkpoint blockades turn on a new paradigm shift in immunotherapy for cancer. Remarkable clinical efficacy, durable response and low toxicity of programmed death 1 (PD-1)/programmed death ligand-1 (PD-L1) checkpoint blockades have been observed in various malignancies. However, a lot of cancer patients failed to respond to the PD-1/PD-L1 checkpoint blockades. It is crucial to identify a biomarker to predict the response to checkpoint blockades. The overexpression of PD-L1 is an important and widely-explored predictive biomarker for the response to PD-1/PD-L1 antibodies. However PD-L1 staining cannot be used to accurately select patients for PD-1/PD-L1 pathway blockade due to the low prediction accuracy and dynamic changes. Tumor-infiltrating immune cells and molecules in the tumor microenvironment, or along with PD-L1 expression, may be important in predicting clinical benefits of PD-1/PD-L1 checkpoint blockades. Gene analysis has proven to be new approach for judging the potential clinical benefit of immune checkpoint inhibitors, such as mutational landscape and mismatch-repair deficiency. Further preclinical and clinical studies are necessary to carry out before its application in clinical practice. Challenges should be overcome to identify patients accurately who will benefit from PD-1/PD-L1 checkpoint blockades. In this review, we focus on the predictive biomarkers for checkpoint blockades of PD-1/PD-L1 pathway. © 2015 Elsevier Ltd.

Guo Z.,Shandong University | Li S.,Beihang University
IEEE Transactions on Aerospace and Electronic Systems | Year: 2010

To extract effective one-dimensional frequency-domain features from high-resolution radar range profiles, the differential power spectrum (DPS) and the product spectrum, which were originally proposed for the speech signal processing, are introduced to the radar target recognition community. Through differentiating the power spectrum with respect to frequency, we obtained the DPS, which is translation invariant. The DPS can preserve the spectral information contained in the range profiles. The product spectrum is defined as the product of the power spectrum and the group delay function. Thus, it can combine the information contained in the magnitude spectrum and phase spectrum of the range profiles and then carry more details about the shape of the aircrafts. In the classification phase, an optimal choice can be determined by implementing six different training algorithms of multilayered feed-forward neural network. The range profiles were measured by using the two-dimensional backscatters distribution data of four different scaled aircraft models. Simulations were demonstrated to evaluate the classification performance with the DPS and the product spectrum-based features. The simulation results have shown that both DPS and product spectrum-based features are effective for the automatic target recognition (ATR) of aircrafts. © 2006 IEEE.

Aguilar-Saavedra J.A.,University of Granada | Bernreuther W.,RWTH Aachen | Si Z.-G.,Shandong University
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2012

We compute, for top quark pair production at the Tevatron and the Large Hadron Collider, the collider-independent forward-backward asymmetries defined by in the standard model at next-to-leading order in QCD, including also electromagnetic and weak corrections. © 2012 American Physical Society.

News Article | March 1, 2017
Site: phys.org

Our brains process information differently on paper and on screen. Information presented on paper involves more emotional processing and produces more brain responses connected with internal feelings. That can make printed material more effective and more memorable than digital media. Of course, paper is still in common use, and global consumption is expected to grow. But paper use comes with significant environmental and sustainability problems. For many years, scientists have worked to develop reading media that have the format of conventional paper but can be reprinted without first having to be industrially recycled. One promising option has been to coat paper with a thin film of chemicals that change color when exposed to light. But previous efforts have encountered problems such as high cost and high toxicity – not to mention difficulty both remaining readable and being erased for reuse. My research group at the University of California, Riverside, in collaboration with Wenshou Wang at Shandong University in China, has recently developed a new coating for regular paper that needs no ink, and can be printed on with light, erased and reused more than 80 times. The coating combines the functions of two types of nanoparticles, particles 100,000 times thinner than a piece of paper; one particle is able to get energy from light and initiates color change of the other. This represents an important step toward the development of reprintable paper. About 35 percent of all harvested trees in the world are used to make paper and cardboard. Worldwide, the pulp and paper industry is the fifth largest consumer of energy and uses more water to produce a ton of product than any other industry. Pulp extraction consumes large amounts of energy and can involve dangerous chemicals like dioxin. Paper production results in the emission of the nutrient phosphorus. That, in turn, boosts plant growth, which can use up all the oxygen in the water and kill any animal life. Even after paper is made, its use damages the environment. Trucking paper from where it's made to where it's used generates air pollution. And making and using ink and toner also harm the environment, by contaminating water, poisoning soil and destroying the natural habitats of wildlife. Our method uses nontoxic ingredients and permits repeated reuse of paper, thereby reducing the environmental effects. In developing a coating for paper, it's important to find one that is transparent but can change color to something visible – and back. That way, any text or images can be made readable like on normal paper, but also easily erased. Our method combines nanoparticles – particles between 1 and 100 nanometers in size – of two different materials that can change from clear to visible and back again. The first material is Prussian blue, a widely used blue pigment most familiar as the blue color in architectural blueprints or inks. Prussian blue nanoparticles normally appear blue, of course, but can become colorless when they are supplied with additional electrons. The second material is nanoparticles of titanium dioxide. When exposed to ultraviolet light, they release the electrons the Prussian blue needs to turn colorless. Our technique combines these two nanoparticles into a solid coating on conventional paper. (It can also be applied to other solids, including plastic sheets and glass slides.) When we shine ultraviolet light on the coated paper, the titanium dioxide produces electrons. The Prussian blue particles pick up those electrons and change color from blue to clear. The printing can be done through a mask, which is a clear plastic sheet printed with letters and patterns in black. The paper starts out entirely blue. When UV light passes through the blank areas on the mask, it changes the corresponding areas on the paper underneath into white, replicating the information from the mask to the paper. The printing is fast, taking only a few seconds to complete. The resolution is very high: It can produce patterns as tiny as 10 micrometers, 10 times smaller than what our eyes can see. The paper will remain readable for more than five days. Its readability will slowly degrade, as the oxygen in the air takes electrons from the Prussian blue nanoparticles and turn them back to blue. The printing can also be done using a laser beam, which scans across the paper surface and exposes the areas that should be white, in a way similar to how today's laser printers work. Erasing a page is easy: Heating the paper and film to about 120 degrees Celsius (250 degrees Fahrenheit) speeds up the oxidation reaction, erasing the printed content completely within about 10 minutes. This temperature is far lower than the temperature at which paper ignites, so there is no danger of fire. It is also lower than the temperature involved in current laser printers, which need to reach about 200 degrees Celsius (392 degrees Fahrenheit) to instantly fuse the toner onto the paper. Using Prussian blue as a part of this process offers a significant number of advantages. First, it is highly chemically stable. Previous rewritable papers usually used organic molecules as the main color-change materials, but they break down easily after being exposed to UV light during printing. As a result, they don't allow very many cycles of printing and erasing. By contrast, Prussian blue molecules remain essentially intact even after long-term exposure to ultraviolet light. In our lab, we have been able to write and erase a single sheet more than 80 times without observing any apparent changes to the intensity of the color or the speed of the switch. In addition, Prussian blue can be easily modified to produce different colors, so blue isn't the only option. We can change the pigment's chemical structure, replacing some of its iron with copper to make a green pigment, or entirely replacing the iron with cobalt to make brown. At present, we're able to print in only one color at a time. As we develop this technology further, we hope to make rewritable paper available for many uses of displaying information, especially temporary uses like newspapers, magazines and posters. Other uses extend to manufacturing, health care and even simple organizing, such as making rewritable labels. It's probably not feasible to hope for a completely paperless society, but we are working on helping people use far less paper than they do – and more easily reusing it when they're ready. Explore further: No ink required: paper can be printed with light

Zhang H.,Shandong University | Feng G.,City University of Hong Kong | Han C.,Shandong University | Han C.,University of Jinan
Systems and Control Letters | Year: 2011

This paper is concerned with the linear estimation problems for discrete-time systems with random delayed observations. When the random delay is known online, i.e., time-stamped, the random delayed system is reconstructed as an equivalent delay-free one by using measurement reorganization technique, and then an optimal linear filter is presented based on the Kalman filtering technique. However, the optimal filter is time-varying, stochastic, and does not converge to a steady state in general. Then an alternative suboptimal filter with deterministic gains is developed under a new criteria. The estimator performance in terms of their error covariances is provided, and its mean square stability is established. Finally, a numerical example is presented to illustrate the efficiency of proposed estimators. © 2011 Elsevier B.V. All rights reserved.

Zheng F.-B.,University of Jinan | Zhang C.-W.,University of Jinan | Yan S.-S.,Shandong University | Li F.,University of Jinan
Journal of Materials Chemistry C | Year: 2013

Motivated by experimental developments on silicene nanosheets, we performed first-principles calculations to study the geometric, electronic and magnetic properties of pristine, N or B doped, as well as N and B co-doped silicene nanoribbons (SiNRs). It is shown that the substitution of N or B for Si is preferentially at the ribbon edge sites. A singly substituted N or B atom at the edges results in a semiconductor-metal transition in armchair silicene nanoribbons (ASiNRs) because of the appearance of half-filled impurity band near the Fermi level. When the N/N or B/B atoms are doped into ASiNRs at two opposite edges, they preserve the metallic character due to a negligible impurity-impurity interaction, independent of the ribbon widths. However, the co-doped systems with N and B atoms exhibit semiconducting behavior with band gaps smaller than the corresponding pristine forms, due to effective charge compensation between N or B atoms. When Si is substituted by an N or B atom in zigzag silicene nanoribbons (ZSiNRs), the systems show ferromagnetic (FM) character, which is attributed to the perturbation of π and π* states localized at the doped edges. More importantly, the marvelous half-metal and spin gapless semiconductor with 100% spin polarized currents around the Fermi level has been found in N-doped ZSiNRs. Providing that the doping with two N/N or B/B atoms is made in ZSiNRs, the spin-polarization at both Si edges is found to be compressed, and thus they exhibit nonmagnetic behavior. However, when the N and B atoms are co-doped into ZSiNRs at the most stable edge positions, a transition from metallic to semiconducting state will appear. These predicted properties may lead to a new route for energy band engineering of SiNRs and benefit the design of silicene-based electronic devices in nanoelectronics. This journal is © 2013 The Royal Society of Chemistry.

Yu X.,CAS Shanghai Institutes for Biological Sciences | Yu X.,Shandong University | Li G.,Shandong University | Chen L.,CAS Shanghai Institutes for Biological Sciences | Chen L.,Tokyo University of Science
Bioinformatics | Year: 2014

Motivation: In this article, we develop a novel edge-based network i.e. edge-network, to detect early signals of diseases by identifying the corresponding edge-biomarkers with their dynamical network biomarker score from dynamical network biomarkers. Specifically, we derive an edge-network based on the second-order statistics representation of gene expression profiles, which is able to accurately represent the stochastic dynamics of the original biological system (with Gaussian distribution assumption) by combining with the traditional node-network, which is based only on the first-order statistics representation of the noisy data. In other words, we show that the stochastic network of a biological system can be described by the integration of its node-network and its edge-network in an accurate manner.Results: By applying edge-network analysis to gene expressions of healthy adults within live influenza experiment sampling at time points before the appearance of infection symptoms, we identified the edge-biomarkers (80 edges with 22 densely connected genes) discovered in edge-networks corresponding to symptomatic adults, which were used to predict the subsequent outcomes of influenza infection. In particular, we not only correctly predict the final infection outcome of each individual at an early time point before his/her clinic symptom but also reveal the key molecules during the disease progression. The prediction accuracy achieves ∼90% under the leave-one-out cross-validation. Furthermore, we demonstrate the superiority of our method on disease classification and predication by comparing with the conventional node-biomarkers. Our edge-network analysis not only opens a new way to understand pathogenesis at a network level due to the new representation for a stochastic network, but also provides a powerful tool to make the early diagnosis of diseases. © 2013 The Author 2013. Published by Oxford University Press. All rights reserved.

Yu H.,Shandong University | Wang D.-D.,Shandong University | Wang Y.,Shandong University | Liu T.,Shandong University | And 2 more authors.
Journal of Neuroscience | Year: 2012

Brain-derived neurotrophic factor (BDNF) plays important roles in cell survival, neural plasticity, learning, and stress regulation. However, whether the recently found human BDNF Val66Met (BDNF Met) polymorphism could alter stress vulnerability remains controversial. More importantly, the molecular and structural mechanisms underlying the interaction between the BDNF Met polymorphism and stress are unclear. We found that heterozygous BDNF + et mice displayed hypothalamic-pituitary-adrenal axis hyperreactivity, increased depressive-like and anxiety-like behaviors, and impaired working memory compared with WT mice after 7 d restraint stress. Moreover, BDNF + et mice exhibited more prominent changes in BDNF levels and apical dendritic spine density in the prefrontal cortex and amygdala after stress, which correlated with the impaired working memory and elevated anxiety-like behaviors. Finally, the depressive-like behaviors in BDNF + et mice could be selectively rescued by acute administration of desipramine but not fluoxetine. These data indicate selective behavioral, molecular, and structural deficits resulting from the interaction between stress and the human genetic BDNF Met polymorphism. Importantly, desipramine but not fluoxetine has antidepressant effects on BDNF + et mice, suggesting that specific classes of antidepressant may be a more effective treatment option for depressive symptoms in humans with this genetic variant BDNF. © 2012 the authors.

Chen L.Y.,Tohoku University | Fujita T.,Tohoku University | Ding Y.,Shandong University | Chen M.W.,Tohoku University
Advanced Functional Materials | Year: 2010

Bimetallic core-shell nanostructures have attracted increasing attention due to their low material costs along with enhanced chemico-physical properties in comparison with their monometallic counterparts. Here, a novel gold-decorated nanoporous copper (Au > N PC) core-shell composite fabricated by a facile in situ hydrometallurgy approach is reported. Thin gold shells with a controllable thickness are homogeneously deposited onto the internal surfaces of 3D nanoporous copper via a spontaneous displacement reaction while nanoporous copper is utilized as a reduction agent as well as 3D template and substrate. The resulting inexpensive core-shell nanostructure exhibits significant electrocatalytic activity for the oxidation of methanol and high non-enzymatic sensitivity in detecting glucose. © 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

This paper introduces a type of modified hybrid projective synchronization with complex transformationmatrix (CMHPS) for different dimensional fractional-order complex chaos and fractional-order real hyper-chaos. The transformationmatrix in this type of chaotic synchronization is a non-square matrix, and its elements are complex numbers. Based on the stability theory of fractional-order systems, by employing the feedback control technique, necessary and sufficient criteria on CMHPS are derived. Furthermore, CMHPS between fractional-order real hyper-chaotic Rössler system and other two different dimensional fractional-order complex Lorenz-like chaotic systems is provided as two examples to discuss reduced order and increased order synchronization, respectively. © 2014 by the authors.

Li G.,Shandong University | Li G.,Shandong University of Technology | Liu H.-W.,Shandong University
Fuzzy Sets and Systems | Year: 2016

This paper deals with the distributivity and conditional distributivity of uninorms with continuous underlying operators over continuous triangular conorms. In particular, the involved triangular conorm is either maximum operator or an ordinal sum with only one summand in which the corresponding triangular conorm is strict. From the obtained results, it is deduced that distributivity and conditional distributivity are equivalent. Moreover, we obtain the full characterization of some cases of this class of uninorms of which either the underlying triangular norm or triangular conorm is strict. © 2015 Elsevier B.V.

Cui X.,University of Jinan | Hong J.,Shandong University | Gao M.,Shandong University
Energy | Year: 2012

A life cycle assessment was conducted out to estimate the environmental impact of three coal-based electricity generation scenarios commonly used or encouraged in China, namely, sub-critical technology (300 MW), supercritical technology (600 MW), and ultra-supercritical technology (1000 MW). Compared with other scenarios, the ultra-supercritical technology accounted for significantly environmental benefits in most categories, except in the natural land occupation category because of the landfill disposal of coal ash. Optimizing net coal consumption efficiency, reusing coal ash as building material, increasing desulfurization and denitrization system efficiency, and decreasing the road transport distance from coal buyer to supplier are key factors in reducing the overall environmental impact of electricity generation. © 2012 Elsevier Ltd.

Wang R.,Shandong University | Xu C.,University of Jinan | Bi X.,Shandong University | Ding Y.,Shandong University
Energy and Environmental Science | Year: 2012

It is of critical importance to design and fabricate highly active and durable oxygen reduction reaction (ORR) catalysts for the application of proton exchange membrane fuel cells (PEMFCs). By a simple two-step dealloying process, the active components in a Pt/Ni/Al ternary alloy were sequentially leached out in a highly controllable manner, generating a novel nanoporous surface alloy structure. Characterized by an open bicontinuous spongy morphology, the resulting nanostructure is interconnected by ∼3 nm diameter ligaments which are comprised of a Pt/Ni alloy core and a nearly pure Pt surface. In the absence of any catalyst support, these nanoporous surface alloys show much enhanced durability and electrocatalytic activity for ORR as compared to the commercial Pt/C catalyst. At a high potential, such as 0.9 V versus RHE, nanoporous Pt/Ni surface alloys show a remarkable specific activity of 1.23 mA cm -2. These nanomaterials thus hold great potential as cathode catalysts in PEMFCs in terms of facile preparation, clean catalyst surface, and enhanced ORR activity and durability. © 2011 The Royal Society of Chemistry.

Bai D.,Tsinghua University | Li L.,Shandong University
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2012

Camellia is one of the most worldwide used block ciphers, which has been selected as a standard by ISO/IEC. In this paper, we propose several new 7-round impossible differentials of Camellia with 2 FL/FL -1 layers, which turn out to be the first 7-round impossible differentials with 2 FL/FL -1 layers. Combined with some basic techniques including the early abort approach and the key schedule consideration, we achieve the impossible differential attacks on 11-round Camellia-128, 11-round Camellia-192, 12-round Camellia-192, and 14-round Camellia-256, and the time complexity are 2 123.8, 2 121.7, 2 171.4 and 2 238.3 respectively. As far as we know, these are the best results against the reduced-round variants of Camellia. Especially, we give the first attack on 11-round Camellia-128 reduced version with FL/FL -1 layers. © 2012 Springer-Verlag.

Chen M.,Xiamen University | Chen M.,Shandong University
Nonlinear Analysis: Real World Applications | Year: 2012

We prove that the maximum norm of velocity gradients controls the possible breakdown of smooth (strong) solutions for the 3-dimensional viscous, compressible micropolar fluids. More precisely, if a solution of the system is initially regular and loses its regularity at some later time, then the loss of regularity implies the growth without the bound of the velocity gradients as the critical time approaches. Our result is a generalization of Huang et al. (2011) [13] from viscous barotropic flows to the viscous, compressible micropolar fluids. In addition, initial vacuum states are also allowed in our result. © 2011 Elsevier Ltd. All rights reserved.

Zhang W.,University of Jinan | Yang S.,Shandong University
Energy Policy | Year: 2013

This paper investigated the causal relationship between energy consumption and gross domestic product (GDP) in China at both aggregated and disaggregated levels during the period of 1978-2009 by using a modified version of the Granger (1969) causality test proposed by Toda and Yamamoto (1995) within a multivariate framework. The empirical results suggested the existence of a negative bi-directional Granger causality running from aggregated energy consumption to real GDP. At disaggregated level of energy consumption, the results were complicated. For coal, empirical findings suggested that there was a negative bi-directional Granger causality running from coal consumption to real GDP. However, for oil and gas, empirical findings suggested a positive bi-directional Granger causality running from oil as well as gas consumption to real GDP. Though these results supported the feedback hypothesis, the negative relationship might be attributed to the growing economy production shifting towards less energy intensive sectors and excessive energy consumption in relatively unproductive sectors. The results indicated that policies with reducing aggregated energy consumption and promoting energy conservation may boost China's economic growth. © 2012 Elsevier Ltd.

Xu C.,University of Jinan | Wang L.,Shandong University | Mu X.,University of Jinan | Ding Y.,Shandong University
Langmuir | Year: 2010

We describe a facile route to the straightforward fabrication of nanoporous (NP) PtRu alloys with predetermined bimetallic compositions. Electron microscopy and X-ray diffraction characterizations demonstrate that selective etching of Al from ternary PtRuAl source alloys generates three-dimensional bicontinuous NP-PtRu alloy nanostructures with a single-phase face-centered-cubic crystalline structure. X-ray photoelectron spectroscopy shows a slight electronic structure modification of Pt by alloying with Ru as well as uniform surface and bulk bimetallic ratio. With characteristic structural dimensions less than 5 nm, these high surface area bimetallic nanostructures show distinct electrocatalytic performance as the Ru content varies within the structure. Among all samples, NP-Pt70Ru 30 shows the highest specific activity as well as the most negative onset potential toward methanol oxidation reaction. NP-Pt50Ru 50 was found to possess a similar specific activity to the commercial E-TEK Pt50Ru50/C catalyst, but its onset and peak potentials are about 70 mV more negative. CO stripping experiments demonstrate that the adsorption of CO is the weakest on NP-Pt70Ru30, and further increasing the Ru content actually shifts the CO stripping peak to a more positive potential. Thus, the overall sequence for CO-tolerance is NP-Pt70Ru30 > NP-Pt50Ru50 ≈ Pt50Ru50/C > NP-Pt30Ru70 > Pt/C. © 2010 American Chemical Society.

Ge S.,Shandong University | Liu F.,Shandong University | Liu W.,University of Jinan | Yan M.,Shandong University | And 2 more authors.
Chemical Communications | Year: 2014

A novel colorimetric assay was established based on folic acid-conjugated porous Pd@Au nanoparticles possessing peroxidase-like activity as labels for the rapid detection of human chronic myelogenous leukemia cell lines (K-562). © 2014 The Royal Society of Chemistry.

Jia C.,University of Jinan | Yang P.,University of Jinan | Huang B.,Shandong University
ChemCatChem | Year: 2014

Ag/AgCl necklace-like nano-heterostructures with an average diameter of 55 nm were prepared by a facile in situ oxidation process. As a result of the presence of multiple crystalline Ag nanowires with lots of grain boundaries, uniform Ag/AgCl necklace-like heterostructures can be successfully obtained in the presence of polyvinylpyrrolidone (PVP). Ag and AgCl are evenly distributed in the necklace-like structures, which were divided into a number of tiny units that consisted of Ag and AgCl and enabled easy electron transfer. In contrast, a loose Ag/AgCl structure with large particles was prepared without the addition of PVP. A formation mechanism of the Ag/AgCl nano-heterostructures was proposed. Furthermore, the molar ratio of Ag and AgCl plays an important role in the photocatalytic activity of the nano-heterostructures, which can be tuned simply. The results of photocatalytic investigations demonstrate that the Ag/AgCl heterostructures with an 85% AgCl component have an excellent activity for the decomposition of organic pollutants and water splitting to produce oxygen. Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Zhang A.,Shandong University | Qiu J.,Shandong University | She J.,Tokyo University of Technology
Neural Networks | Year: 2014

This paper concerns the existence and exponential stability of periodic solution for the high-order discrete-time bidirectional associative memory (BAM) neural networks with time-varying delays. First, we present the criteria for the existence of periodic solution based on the continuation theorem of coincidence degree theory and the Young's inequality, and then we give the criteria for the global exponential stability of periodic solution by using a non-Lyapunov method. After that, we give a numerical example that demonstrates the effectiveness of the theoretical results. The criteria presented in this paper are easy to verify. In addition, the proposed analysis method is easy to extend to other high-order neural networks. © 2013 Elsevier Ltd.

Hao S.,University of Jinan | Zhou Y.-J.,Shandong University
Journal of High Energy Physics | Year: 2012

Based on the analysis of 5 fb -1 of data at the LHC, the ATLAS and CMS collaborations have presented evidence for a Higgs boson with a mass in the 125GeV range. We consider the 125GeV neutral Higgs pair production process in the context of large-extra-dimensions (LED) model including the Kaluza-Klein (KK) excited gravitons at the LHC. We take into account the LED effects coming from gluon-gluon fusion and quarkantiquark collision channels as well as their corresponding next-to-leading order (NLO) QCD loop induced corrections. We analyse their impacts on both the total cross section and some key distributions. Indeed, pp → HH has the clear advantage of a lower standard model (SM) background compare to process like pp → jj, though its SM prediction is very small, it is shown that the LED model raises the cross section of Higgs pair production compare to its SM prediction and enhance the transverse momentum (p T H ) and invariant mass (MHH) distributions especially at high scales of p T H and M HH. By including the NLO QCD loop corrections, the scale dependence of total cross section can be reduced obviously. Choose suitable decay modes like HH → bbγγ or HH → bbμ-μ + and some simple cuts, we can strongly reduce the SM background but keep most of the LED effects, leading Higgs pair production a promising channel to search LED effects. © SISSA 2012.

Xu X.,Shandong University | Xu X.,CAS Institute of Vertebrate Paleontology and Paleoanthropology | Zheng X.,Shandong University | Sullivan C.,CAS Institute of Vertebrate Paleontology and Paleoanthropology | And 7 more authors.
Nature | Year: 2015

The wings of birds and their closest theropod relatives share a uniform fundamental architecture, with pinnate flight feathers as the key component. Here we report a new scansoriopterygid theropod, Yi qi gen. et sp. nov., based on a new specimen from the Middle-Upper Jurassic period Tiaojishan Formation of Hebei Province, China. Yi is nested phylogenetically among winged theropods but has large stiff filamentous feathers of an unusual type on both the forelimb and hindlimb. However, the filamentous feathers of Yi resemble pinnate feathers in bearing morphologically diverse melanosomes. Most surprisingly, Yi has a long rod-like bone extending from each wrist, and patches of membranous tissue preserved between the rod-like bones and the manual digits. Analogous features are unknown in any dinosaur but occur in various flying and gliding tetrapods, suggesting the intriguing possibility that Yi had membranous aerodynamic surfaces totally different from the archetypal feathered wings of birds and their closest relatives. Documentation of the unique forelimbs of Yi greatly increases the morphological disparity known to exist among dinosaurs, and highlights the extraordinary breadth and richness of the evolutionary experimentation that took place close to the origin of birds. © 2015 Macmillan Publishers Limited. All rights reserved.

Feng R.,University of Jinan | Song Z.,University of Jinan | Zhai G.,Shandong University
International Journal of Nanomedicine | Year: 2012

Background: Curcumin (CUR) has been linked with antioxidant, anti-inflammatory, antimicrobial, anti amyloid, and antitumor effects, but its application is limited because of its low aqueous solubility and poor oral bioavailability. Methods: To improve its bioavailability and water solubility, we synthesized two series of poly (ε-Caprolactone)-poly (ethylene glycol)-poly (ε-Caprolactone) triblock copolymers by ring-opening polymerization of poly (ethylene glycol) and ε-Caprolactone, with stannous 2-ethylhexanoate as the catalyst. Structure of the copolymers was characterized by proton nuclear magnetic resonance spectroscopy, Fourier transform infrared spectroscopy, and gel permeation chromatography. The nanoparticles (NPs) were prepared using a probe-type ultrasonic emulsion and solvent evaporation method. To obtain an optimal delivery system, we explored the effect of the length of the copolymers' hydrophilic and hydrophobic chains on the encapsulation of hydrophobic CUR, performing entrapment efficiency and drug loading evaluations, as well as studying the particle distribution and in vitro release using the direct dispersion method. Finally, study of the in vivo pharmacokinetics of the CUR-loaded NPs was also carried out on selected copolymers in comparison with CUR solution formulations. Results: CUR was encapsulated with 94.3% and 95.5% efficiency in biodegradable nanoparticulate formulations based on NP43 and NP63, respectively. Dynamic laser light scattering and transmission electron microscopy indicated a particle diameter of 55.6 nm and 62.4 nm for NP43 and NP63, respectively. Fourier transform infrared spectroscopy and differential scanning calorimetry analysis of the NPs showed that CUR was encapsulated into the NPs. The in vitro release experiments showed that NP63 controlled the release of CUR more effectively, with only 55% of CUR released after 96 hours. In comparison with the free-drug solution in vivo, encapsulation of the CUR in NP63 increased mean residence time from 0.169 to 40.148 hours and the area under the concentration-time curve 4.178-fold. Conclusion: CUR was effectively entrapped by the prepared NPs, which could improve the solubility of CUR and prolong its retention in the systemic circulation. © 2012 Feng et al, publisher and licensee Dove Medical Press Ltd.

Zhang C.-W.,University of Jinan | Yan S.-S.,Shandong University
Journal of Physical Chemistry C | Year: 2012

We performed first-principles simulation on the electronic structure and magnetic properties of two-dimensional hexagonal silicene, which was recently synthesized. The results show that the weak overlapping between 3p z orbitals of neighbor Si atoms leads to a very reactive surface, resulting in a more energetically stable semiconducting surface upon being fully hydrogenated. Half-hydrogenation breaks the extended π-bonding network of silicene, leaving the electrons in the unsaturated Si atoms localized and unpaired, and thus it exhibits ferromagnetic semiconducting behavior with a band gap of 0.95 eV. The long-range ferromagnetic coupling between Si atoms was also predicted, with a Curie temperature of about 300 K. These results demonstrated that hydrogenation is an efficient route to tune the electronic properties of silicene sheets. © 2012 American Chemical Society.

Xu J.,Shandong University | Xu J.,University of Jinan | Wang Y.,University of Jinan | Zhang Z.,Shandong University
Journal of Physical Chemistry C | Year: 2012

Electrochemical dealloying of a single-phase Al 2Au alloy in sodium chloride solutions has been investigated considering influence of potential and electrolyte concentration. Both open-circuit potentials and corrosion potentials of Al 2Au decrease with increasing electrolyte concentration and temperature. The overpotential and electrolyte concentration have a significant influence on dealloying behaviors of Al 2Au, such as steady-state current density and dealloying duration. Nanoporous gold (NPG) can be fabricated by potentiostatic dealloying of Al 2Au in the NaCl solutions. Moreover, surface diffusion evaluation demonstrates that there exist good linear relationships between the logarithm of surface diffusivities of Au adatoms (Au ad) and overpotential, and between the surface diffusivities of Au ad and electrolyte concentration. In addition, the activation energy decreases with increasing overpotential or chloride ion concentration. © 2012 American Chemical Society.

Sun H.,University of Jinan | Zhou Y.-J.,Shandong University | Chen H.,Guangdong University of foreign Studies
European Physical Journal C | Year: 2012

Based on the analysis of 5 fb -1 of data at the LHC, the ATLAS and CMS collaborations have presented evidence for a Higgs boson with a mass in the 125 GeV range. We consider the 125 GeV neutral Higgs pair production process in the context of large-extra-dimensions (LED) model including the Kaluza-Klein (KK) excited gravitons at the LHC. We consider the standard model (SM) Higgs pair production in gluon-gluon fusion channel and pure LED effects through graviton exchange as well as their interferences. It is shown that such interferences should be included; the LED model raises the transverse momentum (P t) and invariant mass (M HH) distributions at high scales of P t and M HH of the Higgs pair production. By using the Higgs pair production we could set the discovery limit on the cutoff scale M S up to 6 TeV for δ=2 and 4. 5 TeV for δ=6. © 2012 Springer-Verlag / Società Italiana di Fisica.

Zhang Z.,Shandong University | Wang Y.,University of Jinan | Wang X.,Shandong University
Nanoscale | Year: 2011

We present a facile route to fabricate novel nanoporous bimetallic Pt-Au alloy nanocomposites by dealloying a rapidly solidified Al75Pt 15Au10 precursor under free corrosion conditions. The microstructure of the precursor and the as-dealloyed sample was characterized using X-ray diffraction, scanning electron microscopy, transmission electron microscopy, high-resolution transmission electron microscopy, and energy dispersive X-ray (EDX) analysis. The Al75Pt15Au 10 precursor is composed of a single-phase Al2(Au,Pt) intermetallic compound, and can be fully dealloyed in a 20 wt.% NaOH or 5 wt.% HCl aqueous solution. The dealloying leads to the formation of the nanoporous Pt60Au40 nanocomposites (np-Pt60Au40 NCs) with an fcc structure. The morphology, size and crystal orientation of grains in the precursor can be conserved in the resultant nanoporous alloy. The np-Pt60Au40 NCs consist of two zones with distinct ligament/channel sizes and compositions. The formation mechanism of these np-Pt60Au40 NCs can be rationalized based upon surface diffusion of more noble elements and spinodal decomposition during dealloying. Electrochemical measurements demonstrate that the np-Pt60Au 40 NCs show superior catalytic activity towards the electro-oxidation of methanol and formic acid in the acid media compared to the commercial JM-Pt/C catalyst. This material can find potential applications in catalysis related areas, such as direct methanol or formic acid fuel cells. Our findings demonstrate that dealloying is an effective and simple strategy to realize the alloying of immiscible systems under mild conditions, and to fabricate novel nanostructures with superior performance. © 2011 The Royal Society of Chemistry.

Zhai C.,Shandong University | Zhang W.,University of New South Wales | Mao G.,University of Technology, Sydney
IEEE Transactions on Wireless Communications | Year: 2014

Spectrum sharing between cellular and ad-hoc networks is studied in this work. Weak signals and strong interferences at the cell-edge area usually cause severe performance degradation. To improve the cell-edge users' performance quality while keeping high spectrum efficiency, in this paper, we propose a cooperative spectrum sharing scheme. In the proposed scheme, the ad-hoc users can actively employ cooperative diversity techniques to improve the cellular network downlink throughput. As a reward, a fraction of the cellular network spectrum is released to the ad-hoc network for its own data transmission. To determine the optimal spectrum allocation, we maximize the ad-hoc transmission capacity subject to the constraints on the outage probability of the ad-hoc network and on the throughput improvement ratio of the cellular network. Both the transmission capacity of the ad-hoc network and the average throughput of the cellular network are analyzed using the stochastic geometry theory. Numerical and simulation results are provided to validate our analytical results. They demonstrate that our proposed scheme can effectively facilitate ad-hoc transmissions while moderately improving the cellular network performance. © 2014 IEEE.

Sun D.,Shandong University | Liu F.-J.,Xiamen University | Huang R.-B.,Xiamen University | Zheng L.-S.,Xiamen University
Inorganic Chemistry | Year: 2011

A novel anionic heptadecanuclear silver(I) cluster, (NH4) 17[(μ 6-S)@Ag17(mba)16] •22H2O (1; H2mba = 2-mercaptobenzoic acid), was obtained by the reaction of equivalent molar silver oxide and 2, 2′-dithiodibenzoic acid (H2dtba) under ultrasonic conditions at 50 °C. Complex 1 is a discrete cluster comprised of unexpected mba ligands on the shell and a μ 6-S2- ion in the core, suggesting the occurrence of in situ S-S and S-C(sp2) bond cleavages of the H2dtba ligand. This novel cluster displays moderate orange-red emission in the solid state at room temperature. © 2011 American Chemical Society.

Wang F.,Harbin Institute of Technology | Tan J.,Harbin Institute of Technology | Wang Z.,Shandong University
Energy Conversion and Management | Year: 2014

The local thermal non-equilibrium model is adopted to solve the steady state heat and mass transfer problems of porous media solar receiver. The fluid entrance surface is subjected to concentrated solar radiation, and CH 4/H2O mixture is adopted as feeding gas. The radiative heat transfer equation between porous strut is solved by Rosseland approximation. The impacts of variation in transport and thermophysical characteristics model of gas mixture on thermal performance of porous media receiver are investigated. The transport and thermophysical characteristics models which are not included in software Fluent are programmed by user defined functions (UDFs). The numerical results indicate that models of momentum source term for porous media receiver have significant impact on pressure drop and static pressure distribution, and the radiative heat transfer cannot be omitted during the thermal performance analysis of porous media receiver. © 2014 Elsevier Ltd. All rights reserved.

Tian H.,Shandong University | De Smet I.,Ghent University | De Smet I.,University of Nottingham | Ding Z.,Shandong University
Trends in Plant Science | Year: 2014

Primary and lateral roots comprise root systems, which are vital to the growth and survival of plants. Several molecular mechanisms associated with primary and lateral root growth have been described, including some common regulatory factors for their initiation and development. However, in this opinion article, we discuss the distinct growth behavior of lateral roots in response to environmental cues, such as salinity, gravity, and nutrient availability, which are mediated via specific regulators. We propose that differential growth dynamics between primary and lateral roots are crucial for plants to adapt to the ever-changing environmental conditions. © 2014 Elsevier Ltd.

Gao J.-H.,Shandong University | Gao J.-H.,The Interdisciplinary Center | Liang Z.-T.,Shandong University | Pu S.,The Interdisciplinary Center | And 3 more authors.
Physical Review Letters | Year: 2012

A power expansion scheme is set up to determine the Wigner function that satisfies the quantum kinetic equation for spin-1/2 charged fermions in a background electromagnetic field. Vector and axial-vector current induced by magnetic field and vorticity are obtained simultaneously from the Wigner function. The chiral magnetic and vortical effect and chiral anomaly are shown as natural consequences of the quantum kinetic equation. The axial-vector current induced by vorticity is argued to lead to a local polarization effect along the vorticity direction in heavy-ion collisions. © 2012 American Physical Society.

Scientists have linked air pollution from multiple industries to the ocean’s increased potential to trap carbon. An international team led by scientists at the University of Birmingham in the U.K. and Shandong University in China, have discovered that iron-rich particles likely from steel manufacturing and coal burning were prevalent in the East China Sea. These particles were found to have a thick sulfate coating containing soluble iron, providing evidence to show acid iron dissolution. “Air pollution dissolves iron in aerosols, which may help to fertilize the oceans,” Zongbo Shi, Ph.D., a corresponding author of the study, said in a statement. “We know that air pollution seriously damages human health and terrestrial ecosystems but this ‘new’ source of soluble iron can potentially increase the amount of carbon dioxide stored in the oceans and thus, inadvertently offset global warming.” Scientists have long believed that acids formed from human-generated pollution and natural emissions dissolve iron in airborne particles, which increases the amount of iron in the ocean, but they have lacked the direct evidence needed to prove the theory. Weijun Li, the lead author of the study and a professor at Shandong University, explained the conclusion reached in the study. “The detection of iron sulfate mixed within the sulfate coatings which we analyzed provides the ‘smoking gun’ for acid dissolution because there is no other atmospheric source or process that leads to its formation,” Li said in a statement. The scientists collected three types of iron-bearing particles from the Yellow Sea—the northern part of the East China Sea located between mainland China and the Korean Peninsula. They used microscopic instruments to look for iron-containing nanoscale particles, specifically locating them from thousands of aerosol particles. This showed that iron-rich, fly ash and mineral dust particles had travelled from Asia. The majority of the iron-rich and fly ash particles contained a significant amount of sulfate containing soluble iron. Most atmospheric sulfur dioxide in East Asia is emitted from coal combustion and industry, while the bulk of sulfate particles in the Northern Hemisphere are formed from sulfur dioxide caused by human activities. The research team confirmed that the iron rich sulfate particles found in the Yellow Sea are formed by contact with man-made sulfur dioxide. The new research shows that the airborne particles became acidic after being transported to the Yellow Sea. “Human activities may have led to an increase of atmospherically soluble iron in the oceans by several times since the Industrial Revolution, which could have a major impact on how effective our oceans are regulating our climate,” Shi said. “Controlling air pollution will bring huge benefits to human welfare but it may reduce the amount of nutrients to the surface ocean and thus, the ocean carbon uptake rate. “More work needs to be done to quantify the impact of anthropogenic soluble iron on ocean ecosystems and climate,” he added.

News Article | March 1, 2017
Site: www.eurekalert.org

Iron particles generated by cities and industry are being dissolved by man-made air pollution and washed into the sea - potentially increasing the amount of greenhouse gases that the world's oceans can absorb, a new study suggests. Scientists have long believed that acids formed from human-generated pollution and natural emissions dissolve iron in airborne particles - increasing the amount of iron to the ocean - but have lacked direct evidence to prove this theory. Now, iron-rich particles from steel manufacturing and coal burning, collected in the East China Sea, have been found to have a thick sulphate coating containing soluble iron that provides the 'smoking gun' to prove the theory of acid iron dissolution. Scientists at the University of Birmingham (UK) and Shandong University (China) led an international research partnership with counterparts from universities in US and Japan. The work was funded by the Natural Science Foundation of China and the UK's Natural Environmental Research Council. The team published their findings in Science Advances. Dr Zongbo Shi, the corresponding author of this work, at the University of Birmingham said: "Air pollution dissolves iron in aerosols, which may help to fertilize the oceans. We know that air pollution seriously damages human health and terrestrial ecosystems but this 'new' source of soluble iron can potentially increase the amount of carbon dioxide stored in the oceans and, thus, inadvertently offset global warming." Professor Weijun Li, the lead author of this work, at Shandong University added: "The detection of iron sulphate mixed within the sulphate coatings which we analysed provides the 'smoking gun' for acid dissolution because there is no other atmospheric source or process that leads to its formation." Scientists collected three types of iron-bearing particles from the Yellow Sea, the northern part of the East China Sea located between mainland China and the Korean Peninsula. Sophisticated microscopic instruments were used to look for iron-containing nanoscale particles - specifically locating them from thousands of aerosol particles. Researchers showed that iron-rich, fly ash, and mineral dust particles had travelled from the Asian continent. Most of the iron-rich and fly ash particles contained a significant amount of sulphate containing soluble iron. Most atmospheric sulphur dioxide in East Asia is emitted from coal combustion and industry, whilst the bulk of sulphate particles in the Northern Hemisphere are formed from sulphur dioxide caused by human activities. The research team, thus, confirmed that the iron rich sulphate particles found in the Yellow Sea are formed by contact with man-made sulphur dioxide. The research shows that the airborne particles became acidic after being transported to the Yellow Sea. "Human activities may have led to an increase of atmospherically soluble iron in the oceans by several times since the Industrial Revolution, which could have a major impact on how effective our oceans are regulating our climate," added Dr Shi. "Controlling air pollution will bring huge benefits to human welfare but it may reduce the amount of nutrients to the surface ocean and, thus, the ocean carbon uptake rate. More work needs to be done to quantify the impact of anthropogenic soluble iron on ocean ecosystems and climate."

Mellouki A.,Shandong University | Mellouki A.,French National Center for Scientific Research | Wallington T.J.,Ford Motor Company | Chen J.,Shandong University | Chen J.,Fudan Tyndall Center
Chemical Reviews | Year: 2015

Oxygenated volatile organic compounds (OVOC) are generally more reactive than the alkanes from which they are derived. OVOCs play an active role in the sequence of chemical reactions responsible for tropospheric ozone formation in both polluted and remote environments. Historical measurements of ambient ozone levels and modeling studies suggest that, as a result of human activities, there has been a significant increase in the global tropospheric ozone concentration. In the atmosphere, oxygenated volatile organic compounds from both anthropogenic and biogenic sources undergo various chemical and physical processes, leading to their transformation or removal from the atmosphere. The oxygenated compounds play an important role in determining the oxidizing capacity of the troposphere both on a regional and a global scale. Ozone is a greenhouse gas, and at high concentrations it is known to have adverse effects on human health and ecosystems.

Sun F.,Guangxi Normal University | Yin Z.,Guangxi Normal University | Wang Q.-Q.,Guangxi Normal University | Sun D.,Shandong University | And 2 more authors.
Angewandte Chemie - International Edition | Year: 2013

Inside and outside: Two consecutive postsynthetic modifications, first an elimination reaction in the channels and then bromination at the surface, were realized in a new hybrid metal-organic framework. The dramatic effects of the different groups in the channels and at the surface were studied using gas sorption and the loading/release of solvent and iodine. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Ding L.,Shandong University | Ding L.,University of Manchester | Gonzalez-Longatt F.M.,University of Manchester | Wall P.,University of Manchester | Terzija V.,University of Manchester
IEEE Transactions on Power Systems | Year: 2013

Controlled islanding is an active and effective way of avoiding catastrophic wide area blackouts. It is usually considered as a constrained combinatorial optimization problem. However, the combinatorial explosion of the solution space that occurs for large power systems increases the complexity of solving it. This paper proposes a two-step controlled islanding algorithm that uses spectral clustering to find a suitable islanding solution for preventing the initiation of wide area blackouts by un-damped electromechanical oscillations. The objective function used in this controlled islanding algorithm is the minimal power-flow disruption. The sole constraint applied to this solution is related to generator coherency. In the first step of the algorithm, the generator nodes are grouped using normalized spectral clustering, based on their dynamic models, to produce groups of coherent generators. In the second step of the algorithm, the islanding solution that provides the minimum power-flow disruption while satisfying the constraint of coherent generator groups is determined by grouping all nodes using constrained spectral clustering. Simulation results, obtained using the IEEE 9-, 39-, and 118-bus test systems, show that the proposed algorithm is computationally efficient when solving the controlled islanding problem, particularly in the case of a large power system. © 1969-2012 IEEE.

Wang H.,Zhejiang University of Technology | Zhang H.,Shandong University
Automatica | Year: 2013

This paper considers the linear quadratic (LQ) control problem for the Itô-type stochastic system with input delays. Due to simultaneous appearances of diffusion terms (dependent on the state and the control) as well as delays in the dynamic system, the problem is very involved and remains to be solved. We not only provide the solvable condition of the problem but also the explicit expression of the causal and adapted controller for a kind of LQ problems. All of these are based on a stochastic Riccati equation. The key technique is to pursue the explicit cost value of the LQ problem by FBSDE and derive the analytical controller via the interplay between the original problem and its equivalent abstract description. © 2013 Elsevier Ltd. All rights reserved.

Hyder Ali Muttaqi Shah S.,University of Sindh | Qi H.,Shandong University
Nonlinear Analysis: Real World Applications | Year: 2010

In this work, we have discussed some simple flows of a viscoelastic fluid with fractional Burgers' model in an annular pipe. The fractional calculus approach is introduced in the constitutive relationship of a Burgers' fluid model. Exact analytical solutions are obtained by using Laplace and Weber transforms for two types of flows, namely: Poiseuille flow and Axial Couette flow. © 2009 Elsevier Ltd. All rights reserved.

Shandong University and Georgia State University | Date: 2010-05-07

Disclosed herein are compounds suitable for use as antitumor agents, methods for treating cancer wherein the disclosed compounds are used in making a medicament for the treatment of cancer, methods for treating a tumor comprising, administering to a subject a composition comprising one or more of the disclosed cytotoxic agents, and methods for preparing the disclosed antitumor agents.

News Article | November 2, 2016
Site: www.eurekalert.org

Even in today's digital age, the world still relies on paper and ink, most of which ends up in landfills or recycling centers. To reduce this waste, scientists have now developed a low-cost, environmentally friendly way to create printed materials with rewritable paper. Their report on the material, which is made out of tungsten oxide and a common polymer used in medicines and food, appears in the journal ACS Applied Materials & Interfaces. The U.S. has been working to reduce paper waste by increasing recycling efforts for years. According to the Environmental Protection Agency, more paper is now recovered for recycling than almost all other materials combined. This saves energy, water, landfill space and greenhouse gas emissions. But even more waste could be avoided if consumers could reuse paper many times before recycling or trashing it. So far, however, such products under development often are made with toxic, expensive organic dyes. Ting Wang, Dairong Chen and colleagues wanted to come up with a better solution. The researchers created a film by mixing low-toxicity tungsten oxide with polyvinyl pyrrolidone. To "print" on it, they exposed the material to ultraviolet light for 30 seconds or more, and it changed from white to a deep blue. To make pictures or words, a stencil can be used so that only the exposed parts turn blue. To erase them, the material can simply sit in ambient conditions for a day or two. To speed up the erasing, the researchers added heat to make the color disappear in 30 minutes. Alternatively, adding a small amount of polyacrylonitrile to the material can make designs last for up to 10 days. Testing showed the material could be printed on and erased 40 times before the quality started to decline. The authors acknowledge funding from Shandong University and Shandong Province. The abstract that accompanies this study is available here. The American Chemical Society is a nonprofit organization chartered by the U.S. Congress. With nearly 157,000 members, ACS is the world's largest scientific society and a global leader in providing access to chemistry-related research through its multiple databases, peer-reviewed journals and scientific conferences. Its main offices are in Washington, D.C., and Columbus, Ohio. To automatically receive news releases from the American Chemical Society, contact newsroom@acs.org.

Feng Z.,University of Washington | Feng Z.,Shandong University | Zhang J.,University of Washington | Zhang J.,Case Western Reserve University
Nucleic Acids Research | Year: 2012

Homologous recombination (HR) is a major mechanism utilized to repair blockage of DNA replication forks. Here, we report that a sister chromatid exchange (SCE) generated by crossover-associated HR efficiently occurs in response to replication fork stalling before any measurable DNA double-strand breaks (DSBs). Interestingly, SCE produced by replication fork collapse following DNA DSBs creation is specifically suppressed by ATR, a central regulator of the replication checkpoint. BRCA1 depletion leads to decreased RPA2 phosphorylation (RPA2-P) following replication fork stalling but has no obvious effect on RPA2-P following replication fork collapse. Importantly, we found that BRCA1 promotes RAD51 recruitment and SCE induced by replication fork stalling independent of ATR. In contrast, BRCA1 depletion leads to a more profound defect in RAD51 recruitment and SCE induced by replication fork collapse when ATR is depleted. We concluded that BRCA1 plays a dual role in two distinct HR-mediated repair upon replication fork stalling and collapse. Our data established a molecular basis for the observation that defective BRCA1 leads to a high sensitivity to agents that cause replication blocks without being associated with DSBs, and also implicate a novel mechanism by which loss of cell cycle checkpoints promotes BRCA1-associated tumorigenesis via enhancing HR defect resulting from BRCA1 deficiency. © The Author(s) 2011. Published by Oxford University Press.

Wang H.,Shandong University | Wang H.,University of South Carolina | Wang K.,Shandong University
Journal of Computational Physics | Year: 2011

Fractional diffusion equations model phenomena exhibiting anomalous diffusion that cannot be modeled accurately by the second-order diffusion equations. Because of the nonlocal property of fractional differential operators, the numerical methods for fractional diffusion equations often generate dense or even full coefficient matrices. Consequently, the numerical solution of these methods often require computational work of O(N 3) per time step and memory of O(N 2) for where N is the number of grid points. In this paper we develop a fast alternating-direction implicit finite difference method for space-fractional diffusion equations in two space dimensions. The method only requires computational work of O(N log 2N) per time step and memory of O(N), while retaining the same accuracy and approximation property as the regular finite difference method with Gaussian elimination. Our preliminary numerical example runs for two dimensional model problem of intermediate size seem to indicate the observations: To achieve the same accuracy, the new method has a significant reduction of the CPU time from more than 2 months and 1 week consumed by a traditional finite difference method to 1.5. h, using less than one thousandth of memory the standard method does. This demonstrates the utility of the method. © 2011 Elsevier Inc.

Jia Y.,Shandong University | Chen F.,Shandong University | Vazquez De Aldana J.R.,University of Salamanca
Optics Express | Year: 2012

Cladding waveguides have been produced in Nd:YVO4 crystals by using femtosecond laser inscription. Such structures are fabricated with circular cross sections and diameters of ∼100-120 μm, supporting multimode guidance in the two orthogonal polarizations. At room temperature continuous wave laser oscillations at wavelength of ∼1064 nm have been realized through the optical pump at 808 nm with slope efficiency as high as 65% and a maximum output power of 335 mW. ©2012 Optical Society of America.

Mu Q.,Shandong University | Mu Q.,Fred Hutchinson Cancer Research Center | Mu Q.,University of Washington | Jiang G.,CAS Research Center for Eco Environmental Sciences | And 5 more authors.
Chemical Reviews | Year: 2014

A recently reported incident of severe pulmonary fibrosis caused by inhaled polymer nanoparticles in seven female workers obtained much attention. In addition to the release of ENM waste from industrial sites, a major release of ENMs to environmental water occurs due to home and personal use of appliances, cosmetics, and personal products, such as shampoo and sunscreen. Airborne and aqueous ENMs pose immediate danger to the human respiratory and gastrointestinal systems. ENMs may enter other human organs after they are absorbed into the bloodstream through the gastrointestinal and respiratory systems. Practically, a thorough understanding of the fundamental chemical interactions between nanoparticles and biological systems has two direct impacts. First, this knowledge will encourage and assist experimental approaches to chemically modify nanoparticle surfaces for various industrial or medicinal applications.

Dong N.,Shandong University | Chen F.,Shandong University | Vazquez de Aldana J.R.,University of Salamanca
Physica Status Solidi - Rapid Research Letters | Year: 2012

We report on the fabrication of nonlinear KTiOPO 4 (KTP) cladding waveguides by using femtosecond-laser direct inscription. The produced guiding structures with a circular cross section of ∼100 μm diameter support good light confinement both for the visible and infrared, for TE and TM polarization. Under the 1064 nm pulsed fundamental pump beam, guided-wave second harmonic generation (SHG) at 532 nm has been realized with an optical conversion efficiency as high as 45.6% (∼0.076% W -1 cm -2), which is three times the magnitude of the normalized efficiency obtained for "double-line" KTP waveguides (fabricated with the aim of comparison), thus showing an intriguing potential as integrated frequency converters. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Ren Y.,Shandong University | Vazquez De Aldana J.R.,University of Salamanca | Chen F.,Shandong University | Zhang H.,Shandong University
Optics Express | Year: 2013

Optical channel waveguides have been produced in Nd:LGS laser crystals by using ultrafast laser inscription with a depressed cladding configuration. The cross sectional shape of the cladding waveguides is circular, surrounded by low refractive index tracks, which makes the channel waveguides as three-dimensional tubular structures. Under optical pump of 810 nm light, continuous-wave waveguide lasers at 1068 nm have been achieved at room temperature, with minimum lasing threshold of 54 mW, a maximum slope efficiency of 24% and a maximum output power of 16 mW. © 2013 Optical Society of America.

Liu H.,Shandong University | Chen F.,Shandong University | De Aldana J.R.V.,University of Salamanca | Jaque D.,Fluorescence Imaging Group
Optics Letters | Year: 2013

We report on the design and implementation of a prototype of optical waveguides fabricated in Nd:YAG crystals by using femtosecond-laser irradiation. In this prototype, two concentric tubular structures with nearly circular cross sections of different diameters have been inscribed in the Nd:YAG crystals, generating double-cladding waveguides. Under 808 nm optical pumping, waveguide lasers have been realized in the double-cladding structures. Compared with single-cladding waveguides, the concentric tubular structures, benefiting from the large pump area of the outermost cladding, possess both superior laser performance and nearly single-mode beam profile in the inner cladding. Double-cladding waveguides of the same size were fabricated and coated by a thin optical film, and a maximum output power of 384 mW and a slope efficiency of 46.1% were obtained. Since the large diameters of the outer claddings are comparable with those of the optical fibers, this prototype paves a way to construct an integrated single-mode laser system with a direct fiber-waveguide configuration. © 2013 Optical Society of America.

Ma Z.M.,Shandong University | Hu B.Q.,Hubei University
Fuzzy Sets and Systems | Year: 2014

Filters play an important role in studying logical systems and the related algebraic structures. Various filters have been proposed in the literature. In this paper, we aim to develop a unifying definition for some specific filters called I-filters which provide us with a meaningful method to study these filters and corresponding logical algebras. In particular, trivial characterizations of I-filters, non-trivial characterizations of classes of I-filters, such as implicative, fantastic and Boolean filters, and characterizations of homologous logical algebras are obtained. Next, three new types of I-filters named divisible filters, strong and n-contractive filters in residuated lattices are introduced. Particularly, it is verified that n-fold implicative BL-algebras and n-contractive BL-algebras coincide. Finally, we investigate the relationships between these specific I-filters. It is shown that a filter is a fantastic filter if and only if it is both a divisible filter and a regular filter. © 2013 Elsevier B.V. All rights reserved.

Wang H.,University of South Carolina | Du N.,Shandong University
Journal of Computational Physics | Year: 2013

Fractional diffusion equations model phenomena exhibiting anomalous diffusion that cannot be modeled accurately by second-order diffusion equations. Because of the non-local property of fractional differential operators, numerical methods for space-fractional diffusion equations generate dense or even full coefficient matrices with complicated structures. Traditionally, these methods were solved with Gaussian elimination, which requires computational work of O(N3) per time step and O(N2) of memory to store where N is the number of spatial grid points in the discretization. The significant computational work and memory requirement of these methods makes a numerical simulation of three-dimensional space-fractional diffusion equations computationally prohibitively expensive.In this paper we develop an efficient and faithful solution method for the implicit finite difference discretization of time-dependent space-fractional diffusion equations in three space dimensions, by carefully analyzing the structure of the coefficient matrix of the finite difference method and delicately decomposing the coefficient matrix into a combination of sparse and structured dense matrices. The fast method has a computational work count of O(Nlog. N) per iteration and a memory requirement of O(N), while retaining the same accuracy as the underlying finite difference method solved with Gaussian elimination. Numerical experiments of a three-dimensional space-fractional diffusion equation show the utility of the fast method. © 2013 Elsevier Inc.

Wang H.,Shandong University | Wang H.,University of South Carolina | Du N.,Shandong University
Journal of Computational Physics | Year: 2013

Fractional diffusion equations model phenomena exhibiting anomalous diffusion that cannot be modeled accurately by the classical second-order diffusion equations. Because of the nonlocal property of fractional differential operators, the corresponding numerical methods have full coefficient matrices which require storage of O(N2) and computational cost of O(N3) for a problem of size N.We develop a superfast-preconditioned conjugate gradient squared method for the efficient solution of steady-state space-fractional diffusion equations. The method reduces the computational work from O(N2) to O(NlogN) per iteration and reduces the memory requirement from O(N2) to O(N). Furthermore, the method significantly reduces the number of iterations to be mesh size independent.Preliminary numerical experiments for a one-dimensional steady-state diffusion equation with 213 nodes show that the fast method reduces the overall CPU time from 3h and 27min for the Gaussian elimination to 0.39s for the fast method while retaining the accuracy of Gaussian elimination. In contrast, the regular conjugate gradient squared method diverges after 2days of simulations and more than 20,000 iterations. © 2012 Elsevier Inc.

Zhang J.,Shandong University | Zhang J.,York College | Ma Z.,Guangxi Medical University
Journal of Affective Disorders | Year: 2012

Background: Previous studies on the Chinese suicide found some life events prior to the suicide different from those in the West, but there is a lack of summary of the Chinese life event patterns to better understand the effects of the social structure on Chinese suicide. Aim: We tried to identify the life events that precede the Chinese rural youth suicides and compare them with what are found in the West, so as to find the patterns that are particularly true in the Chinese culture contexts. Methods: Suicide cases were investigated with a psychological autopsy study in rural China, and local community living controls were also interviewed with the same protocol. Results: We collapsed 64 negative life events into six categories: (1) Marriage/Love, (2) Family/Home, (3) Work/Business, (4) Health/Hospital, (5) Law/Legal, (6) Friend/Relationship. About 92.3% of the suicides studied had experienced at least one type of negative life events. The three most common negative life events categories in the past one year were Family/Home (60.7%), Health/Hospital (53.8%) and Marriage/Love (51.3%) in the rural young suicide victims. Conclusions: Among the negative life events, those related to family relations, love affairs, and marital issues were most likely to precede a suicide of rural suicides in China, and it is especially true of rural young women. Family is an important social institution in rural China for suicide prevention efforts. © 2012 Elsevier B.V.

Pefanis E.,Columbia University | Pefanis E.,Regeneron Pharmaceuticals and Regeneron Genetics Center | Wang J.,Columbia University | Rothschild G.,Columbia University | And 11 more authors.
Cell | Year: 2015

We have ablated the cellular RNA degradation machinery in differentiated B cells and pluripotent embryonic stem cells (ESCs) by conditional mutagenesis of core (Exosc3) and nuclear RNase (Exosc10) components of RNA exosome and identified a vast number of long non-coding RNAs (lncRNAs) and enhancer RNAs (eRNAs) with emergent functionality. Unexpectedly, eRNA-expressing regions accumulate R-loop structures upon RNA exosome ablation, thus demonstrating the role of RNA exosome in resolving deleterious DNA/RNA hybrids arising from active enhancers. We have uncovered a distal divergent eRNA-expressing element (lncRNA-CSR) engaged in long-range DNA interactions and regulating IgH 3′ regulatory region super-enhancer function. CRISPR-Cas9-mediated ablation of lncRNA-CSR transcription decreases its chromosomal looping-mediated association with the IgH 3′ regulatory region super-enhancer and leads to decreased class switch recombination efficiency. We propose that the RNA exosome protects divergently transcribed lncRNA expressing enhancers by resolving deleterious transcription-coupled secondary DNA structures, while also regulating long-range super-enhancer chromosomal interactions important for cellular function. © 2015 Elsevier Inc.

Ren Y.,Shandong University | Chen F.,Shandong University | De Aldana J.R.V.,University of Salamanca
Optics Express | Year: 2013

A design of cladding waveguides in Nd: YCOB nonlinear crystals is demonstrated in this work. Compact Fabry-Perot oscillation cavities are employed for waveguide laser generation at 1062 nm and self-frequency-doubling at 531 nm, under optical pump at 810 nm. The waveguide laser shows slope efficiency as high as 55% at 1062 nm. The SFD green waveguide laser emits at 531 nm with a maximum power of 100 μW. © 2013 Optical Society of America.

Wang H.,Shandong University | Wang H.,University of South Carolina | Tian H.,Shandong University
Journal of Computational Physics | Year: 2012

Peridynamic theory provides an appropriate description of the deformation of a continuous body involving discontinuities or other singularities, which cannot be described properly by classical theory of solid mechanics. However, the operators in the peridynamic models are nonlocal, so the resulting numerical methods generate dense or full stiffness matrices. Gaussian types of direct solvers were traditionally used to solve these problems, which requires O(N 3) of operations and O(N 2) of memory where N is the number of spatial nodes. This imposes significant computational and memory challenge for a peridynamic model, especially for problems in multiple space dimensions. A simplified model, which assumes that the horizon of the material δ=O(N -1), was proposed to reduce the computational cost and memory requirement to O(N). However, the drawback is that the corresponding error estimate becomes one-order suboptimal. Furthermore, the assumption of δ=O(N -1) does not seem to be physically reasonable since the horizon δ represents a physical property of the material that should not depend on computational mesh size. We develop a fast Galerkin method for the (non-simplified) peridynamic model by exploiting the structure of the stiffness matrix. The new method reduces the computational work from O(N 3) required by the traditional methods to O(Nlog 2N) and the memory requirement from O(N 2) to O(N) without using any lossy compression. The significant computational and memory reduction of the fast method is better reflected in numerical experiments. When solving a one-dimensional peridynamic model with 2 14=16, 384 unknowns, the traditional method consumed CPU time of 6days and 11h while the fast method used only 3.3s. In addition, on the same computer (with 128GB memory), the traditional method with a Gaussian elimination or conjugate gradient method ran out of memory when solving the problem with 2 16=131, 072 unknowns. In contrast, the fast method was able to solve the problem with 2 28=268, 435, 456 unknowns using 3days and 11h of CPU time. This shows the benefit of the significantly reduced memory requirement of the fast method. © 2012 Elsevier Inc.

Ma X.,Shandong University | Dai Y.,Shandong University | Guo M.,National Supercomputer Center in Jinan | Huang B.,Shandong University
Langmuir | Year: 2013

The photoredox ability of the TiO2 {100}, {101}, and {001} surfaces is investigated by examining the trapping energies, trapping sites, and relative oxidation and reduction potentials of simulated photogenerated holes and electrons in the form of more realistic polaronic states on the basis of density functional electronic structure calculations. Our results enable us to re-estimate their relative photooxidation ({100} > {101} > {001}) and photoreduction ({100} > {101} > {001}) activities, which rectify the conventional understanding. The dual functions of the surface under coordinated atoms acting as active adsorption sites for adsorbates and hindering the population of electrons to the outermost surface layer are identified, and the specific surface geometric structures also play an important role in trapping holes and electrons through the ease of lattice distortion. In addition, we attribute the commonly low photocatalytic performance of the {101} surface to the large and similar trapping energies and adjacent trapping sites for electrons and holes, which result in high electron-hole recombination rates. However, the large difference in trapping energies for electrons and holes on different surfaces allows us to spatially gather electrons and holes on different surfaces by artificially designing the exposing facets of nanocrystals without resorting to the energy band potential difference between surfaces, thus expanding the ideas to improve the photocatalytic properties of materials through the regulation of crystal facets. Our present work can provide a helpful message for the design of more reactive photocatalytic TiO2 nanocrystals and the fabrication of other reactive photocatalysts. © 2013 American Chemical Society.

Zhang Y.-T.,Shandong University | Shang W.-L.,China Academy of Engineering Physics
Physics of Plasmas | Year: 2011

In atmospheric radio frequency discharges at 13.56 MHz, with the electrode gap reduced, the sheath region eventually occupies a main portion of the electrode spacing and the bulk plasma region is significantly compressed. The computational results in this letter based on a one-dimensional fluid model show that by increasing the excitation frequency over 13.56 MHz, the traditional glow-plasma structure could gradually recover even at very small sizes with a well defined quasineutral plasma region, and the electron density is improved but the electric fields in sheath region are reduced. This study indicates that the excitation frequency can be used to modulate the discharge structure and then tailor the plasma-surface interaction in atmospheric microplasmas. © 2011 American Institute of Physics.

Jia Y.,Shandong University | de Aldana J.R.V.,University of Salamanca | Chen F.,Shandong University
Optical Materials Express | Year: 2013

We report on the fabrication of depressed double-cladding waveguides in Yb:YAG ceramics by using femtosecond (fs) laser inscription. The double-cladding structures consist of tubular central structures with 30 μm diameter and concentric larger size tubular claddings with diameters of 100-200 μm. Continuous wave laser oscillations at wavelength of 1030 nm have been realized at room temperature through optical pump at 946 nm. The obtained maximum output power of the double-cladding waveguide lasers is ̃80.2 mW with a slope efficiency as high as 62.9%. © 2013 Optical Society of America.

Ni S.-Q.,Shandong University | Ni J.-Y.,Shandong University | Hu D.-L.,Tianjin Cement Industry Design and Research Institute Co. | Sung S.,Iowa State University
Bioresource Technology | Year: 2012

The presence of organic matter (OM) is considered to affect anammox process adversely, while practically wastewaters containing ammonia are not free from OM. In this study, the performance of anammox granules in presence of OM was evaluated under different COD to N ratios. Low OM concentration did not affect ammonia and nitrite removal significantly but improved the total nitrogen removal via denitrifiers. High OM could suppress anammox activity, resulting in a lower ammonia removal. PCR tests revealed that there was a reduction in the number of anammox bacteria and denitrifiers quantity increased when 400. mg COD/L influent was applied. A COD to N threshold ratio for anammox inhibition, defined when ammonia removal dropped to 80%, was 3.1, higher than that of flocculent sludge. This study revealed that the coexistence of denitrification and anammox was an effective strategy to treat wastewaters containing high levels of nitrogen and OM. © 2012 Elsevier Ltd.

Wang K.,Shandong University | Wang H.,University of South Carolina
Advances in Water Resources | Year: 2011

Fractional advection-diffusion equations provide an adequate and accurate description of the movement of solute in an aquifer. However, there are major obstacles that restrict their applications. From a modeling viewpoint, one of the major limitations in the application of fractional advection-diffusion equations to hydrology is the poor predictability of model parameters [27]. From a computational view point, one of the major limitations in numerical solution of fractional advection-diffusion equations in multiple space dimensions is that they generate full coefficient matrices in their numerical approximations, which require O(N3) of computational cost and O(N2) storage for a problem of size N.This paper presents a preliminary step towards the efficient numerical solution of fractional advection-diffusion equations. In this paper we develop a fast characteristic finite difference method for the efficient solution of space-fractional transient advection-diffusion equations in one space dimension. This method generates more accurate solutions than standard implicit methods even if much larger time steps and spatial meshes are used, leading to a discrete system with a greatly reduced size. Furthermore, we explore the structure of the coefficient matrix to come up with an efficient iterative solver which requires only O(N) account of storage and roughly O(Nlog. N) account of computational cost.Our preliminary numerical example runs for some simple one dimensional model problems seem to indicate the following observations: to achieve the same accuracy, the new method uses no more than one thousandth of CPU and about one thousandth of the storage used by the standard method. This demonstrates the strong potential of the method. © 2010.

Zhang Y.,Aix - Marseille University | Zhang Y.,Shandong University | Ducret A.,Aix - Marseille University | Shaevitz J.,Princeton University | Mignot T.,Aix - Marseille University
FEMS Microbiology Reviews | Year: 2012

In bird flocks, fish schools, and many other living organisms, regrouping among individuals of the same kin is frequently an advantageous strategy to survive, forage, and face predators. However, these behaviors are costly because the community must develop regulatory mechanisms to coordinate and adapt its response to rapid environmental changes. In principle, these regulatory mechanisms, involving communication between individuals, may also apply to cellular systems which must respond collectively during multicellular development. Dissecting the mechanisms at work requires amenable experimental systems, for example, developing bacteria. Myxococcus xanthus, a Gram-negative delatproteobacterium, is able to coordinate its motility in space and time to swarm, predate, and grow millimeter-size spore-filled fruiting bodies. A thorough understanding of the regulatory mechanisms first requires studying how individual cells move across solid surfaces and control their direction of movement, which was recently boosted by new cell biology techniques. In this review, we describe current molecular knowledge of the motility mechanism and its regulation as a lead-in to discuss how multicellular cooperation may have emerged from several layers of regulation: chemotaxis, cell-cell signaling, and the extracellular matrix. We suggest that Myxococcus is a powerful system to investigate collective principles that may also be relevant to other cellular systems. © 2011 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd.

Xia Y.,Shandong University | Chu W.,Shandong University | Qi Q.,Shandong University | Xun L.,Shandong University | Xun L.,Washington State University
Nucleic Acids Research | Year: 2015

The QuikChangeTM site-directed mutagenesis method is popular but imperfect. An improvement by using partially overlapping primers has been reported several times; however, it is incompatible with the proposed mechanism. The QuikChangeTM method using complementary primers is proposed to linearly amplify a target plasmid with the products annealing to produce double-stranded DNA molecules with 5'-overhangs. The overhang annealing is supposed to form circular plasmids with staggered breaks, which can be repaired in Escherichia coli after transformation. Here, we demonstrated that the PCR enzyme fills the 5'-overhangs in the early cycles, and the product is then used as the template for exponential amplification. The linear DNA molecules with homologous ends are joined to generate the plasmid with the desired mutations through homologous recombination in E. coli. The correct understanding is important to method improvements, guiding us to use partially overlapping primers and Phusion DNA polymerase for site-directed mutagenesis. Phusion did not amplify a plasmid with complementary primers but used partially overlapping primers to amplify the plasmid, producing linear DNA molecules with homologous ends for site-directed mutagenesis. © 2015 The Author(s) 2014. Published by Oxford University Press on behalf of Nucleic Acids Research.

Wang H.,University of South Carolina | Zhang X.,Shandong University
Journal of Computational Physics | Year: 2015

Fractional diffusion equations were shown to provide an adequate and accurate description of transport processes exhibiting anomalous diffusion behavior. Recently, spectral Galerkin methods were developed for space-fractional diffusion equations aiming at achieving exponential convergence. An optimal order error estimate in the fractional energy norm was proved under the assumption that the true solution to the fractional diffusion equation has the desired regularity. An optimal order error estimate in the L2 norm was proved via the well known Nitsche lifting technique under the assumption that the true solution to the corresponding boundary-value problem of the fractional diffusion equation has the required regularity for each right-hand side.In this paper we show that the true solution to the Dirichlet boundary-value problem of a conservative fractional diffusion equation of order 2-β with 0<β<1 as well as a constant diffusivity coefficient and a constant source term is not in the fractional Sobolev space H3/2-β in general, but is still in the Besov space B∞3/2-β(L2). Hence, the provable convergence rate of a spectral Galerkin method in the L2 norm is at most of the order O(N-(3/2-β)), where N is the degree of the polynomial space in the numerical method. Numerical experiments show that the spectral Galerkin method exhibits a subquadratic convergence in the L2 norm for any 0<β<1.We develop a high-accuracy preserving spectral Galerkin method for the Dirichlet boundary-value problem of one-sided variable-coefficient conservative fractional diffusion equations. The method has a proved high-order convergence rate of arbitrary order (i) without requiring the smoothness of the true solution u to the given boundary-value problem, but only assuming that the diffusivity coefficient and the right-hand source term have the desired regularity; (ii) for a variable diffusivity coefficient; and (iii) for an inhomogeneous Dirichlet boundary condition. Numerical experiments substantiate the theoretical analysis and show that the method exhibits exponential convergence provided the diffusivity coefficient and the right-hand source term have the desired regularity. © 2014 Elsevier Inc.

Cui X.,Henan Polytechnic University | Zhao J.,Shandong University
International Journal of Advanced Manufacturing Technology | Year: 2014

In the present study, high-speed face milling of AISI H13 hardened steel was conducted to investigate the cutting performance of coated carbide tools. The characteristics of chip morphology, tool life, tool wear mechanisms, and surface roughness were analyzed and compared for different cutting conditions. It was found that as the cutting speed increased, the chip morphology evolved in different ways under different milling conditions (up, down, and symmetric milling). Individual saw-tooth segments and sphere-like chip formed at the cutting speed of 2,500 m/min. Owing to the relatively low mechanical load, longest tool life can be obtained in up milling when the cutting speed was no more than 1,000 m/min. As the cutting speed increased over 1,500 m/min, highest tool life existed in symmetric milling. When the cutting speed was 500 m/min, owing to the higher mechanical load, the flaked region on the tool rake face in symmetric milling was much larger than that in up and down milling. There was no obvious wear on the tool rake face at the cutting speed of 2,500 m/min due to the short tool-chip contact length. In symmetric milling, the delamination of tool material, which did not occur in up and down milling, was caused by the relatively large cutting force. Abrasion had great effect on the tool flank wear in symmetric milling. With the increment of cutting speed, surface roughness decreased first and then increased rapidly. Lowest surface roughness can be obtained at the cutting speed of about 1,500 m/min. © 2014 Springer-Verlag London.

Wang H.,Shandong University | Wang H.,University of South Carolina | Du N.,Shandong University
Journal of Computational Physics | Year: 2014

Fractional diffusion equations model phenomena exhibiting anomalous diffusion that cannot be modeled accurately by second-order diffusion equations. Because of the nonlocal property of fractional differential operators, numerical methods for space-fractional diffusion equations generate dense or even full coefficient matrices with complicated structures. Traditionally, these methods were solved via Gaussian elimination, which requires computational work of O(N3) per time step and O(N2) of memory to store where N is the number of spatial grid points in the discretization. The significant computational work and memory requirement of these methods makes a numerical simulation of three-dimensional space-fractional diffusion equations computationally prohibitively expensive. We present an alternating-direction implicit (ADI) finite difference formulation for space-fractional diffusion equations in three space dimensions and prove its unconditional stability and convergence rate provided that the fractional partial difference operators along x-, y-, z-directions commute. We base on the ADI formulation to develop a fast iterative ADI finite difference method, which has a computational work count of O(NlogN) per iteration at each time step and a memory requirement of O(N). We also develop a fast multistep ADI finite difference method, which has a computational work count of O(Nlog2N) per time step and a memory requirement of O(NlogN). Numerical experiments of a three-dimensional space-fractional diffusion equation show that these both fast methods retain the same accuracy as the regular three-dimensional implicit finite difference method, but have significantly improved computational cost and memory requirement. These numerical experiments show the utility of the fast method. © 2013 Elsevier Inc.

Zhang J.,Case Western Reserve University | Zhang J.,Shandong University | Dai L.,Case Western Reserve University
ACS Catalysis | Year: 2015

The oxygen reduction reaction (ORR) plays an important role in renewable energy technologies, such as fuel cells and metal-air batteries. Along with the extensive research and development of nonprecious metal catalysts (NPMCs) to reduce/replace Pt for electrocatalytic reduction of oxygen, a new class of heteroatom-doped metal-free carbon catalysts has been recently developed, which, as alternative ORR catalysts, could dramatically reduce the cost and increase the efficiency of fuel cells and metal-air batteries. The improved catalytic performance of heteroatom-doped carbon ORR catalysts has been attributed to the doping-induced charge redistribution around the heteroatom dopants, which lowered the ORR potential and changed the O2 chemisorption mode to effectively weaken the O-O bonding, facilitating ORR at the heteroatom-doped carbon electrodes. Subsequently, this new metal-free ORR mechanism was confirmed by numerous studies, and the same principle has been applied to the development of various other efficient catalysts for not only ORR in fuel cells but also oxygen evolution reaction (OER) in metal-air batteries and hydrogen evolution reaction (HER) in water-splitting systems. However, there are still some concerns about possible contributions of metal impurities to the ORR activities of these carbon catalysts. To avoid unnecessary confusion, therefore, it is important to clarify the situation. In this Perspective, we provide important aspects of the metal-free ORR catalysts with a critical analysis of the literature, along with perspectives and challenges of this rapidly growing field of practical significance. © 2015 American Chemical Society.

Liu H.,Shandong University | Tan Y.,Shandong University | Vazquez De Aldana J.R.,University of Salamanca | Chen F.,Shandong University
Optics Letters | Year: 2014

We report on the fabrication of depressed cladding waveguides in Nd:GdVO4 laser crystal by using femtosecond laser inscription. The cross section of the structure is a circular shape with a diameter of 150 μm. Under the optical pump at 808 nm, the continuous wave (cw) as well as pulsed (Q-switched by graphene saturable absorber) waveguide lasing at 1064 nm has been realized, supporting guidance of both TE and TM polarizations. The maximum output power of 0.57Wwas obtained in the cw regime, while the maximum pulse energy of the pulsed laser emissions was up to 19 nJ (corresponding to a maximum average output power of 0.33 W, at a resonant frequency of 18 MHz). The slope efficiencies achieved for the cw and pulsed Nd:GdVO4 waveguide lasers were as high as 68% and 52%, respectively. © 2014 Optical Society of America.

Gao F.,Shandong University | Barker P.B.,Johns Hopkins University | Barker P.B.,Kennedy Krieger Institute
American Journal of Neuroradiology | Year: 2014

MR spectroscopy is a noninvasive technique that allows the detection of several naturally occurring compounds (metabolites) from well-defined regions of interest within the human brain. Alzheimer disease, a progressive neurodegenerative disorder, is the most common cause of dementia in the elderly. During the past 20 years, multiple studies have been performed on MR spectroscopy in patients with both mild cognitive impairment and Alzheimer disease. Generally, MR spectroscopy studies have found decreased Nacetylaspartate and increased myo-inositol in both patients with mild cognitive impairment and Alzheimer disease, with greater changes in Alzheimer disease than in mild cognitive impairment. This review summarizes the information content of proton brain MR spectroscopy and its related technical aspects, as well as applications of MRspectroscopy to mild cognitive impairment and Alzheimer disease. While MR spectroscopy may have some value in the differential diagnosis of dementias and assessing prognosis, more likely its role in the near future will be predominantly as a tool for monitoring disease response or progression in treatment trials. More work is needed to evaluate the role of MR spectroscopy as a biomarker in Alzheimer disease and its relationship to other imaging modalities.

Xu D.,University of Minnesota | Xu D.,Shandong University | Kane R.L.,University of Minnesota
Journal of the American Geriatrics Society | Year: 2013

Objectives To evaluate the effect of urinary incontinence (UI) on elderly nursing home (NH) residents' self-reported quality of life (QOL), especially on the specific QOL domains most closely associated with UI. Design Retrospective cross-sectional study using the Minimum Data Set (MDS) and Minnesota Nursing Home Report Card data in 2010 to compare overall QOL and its domains of residents with and without UI using propensity scores and inverse probability weighting (IPW) adjustments to reduce selection bias. Setting All Medicare- or Medicaid-licensed NHs in Minnesota. Participants All residents aged 65 and older except those with conditions that could readily overwhelm the effect of UI on QOL, such as coma and cerebral palsy. Measurements Urinary incontinence (UI) was defined as leakage two or more times a week (score ≥2 on MDS 5-point scale), and continence was defined as continent or usually continent (score 0 or 1 on MDS 5-point scale). QOL was assessed using a self-reported QOL questionnaire that measured general QOL, not QOL specific to UI symptoms. Results Urinary incontinence (UI) prevalence was 65.8% in 10,683 older NH residents. Self-reported QOL was good (>0.7 on a scale from 0 to 1) in 8,620 eligible residents in 371 NHs. Mood and meaningful activity domains had lower scores; dignity had the highest score. UI was associated with being older and female, ADL dependence, impaired cognitive ability, Alzheimer's disease, non-Alzheimer's dementia, bowel incontinence, diabetes mellitus, and long-term NH stay. Bivariate analysis found that residents with UI had lower QOL than those without. Using IPW to reduce selection bias, it was found that, although UI was not associated with overall QOL, it decreased the QOL domains of dignity, autonomy, and mood. Conclusion To improve the QOL of residents with UI, attention should be paid to dignity, autonomy, and mood. © 2013, The American Geriatrics Society.

Zheng X.,Shandong University | O'Connor J.,CAS Institute of Vertebrate Paleontology and Paleoanthropology | Wang X.,Shandong University | Wang M.,CAS Institute of Vertebrate Paleontology and Paleoanthropology | And 2 more authors.
Proceedings of the National Academy of Sciences of the United States of America | Year: 2014

Anchiornis (Deinonychosauria: Troodontidae), the earliest known feathered dinosaur, and Sapeornis (Aves: Pygostylia), one of the basalmost Cretaceous birds, are both known from hundreds of specimens, although remarkably not one specimen preserves any sternal ossifications. We use histological analysis to confirm the absence of this element in adult specimens. Furthermore, the excellent preservation of soft-tissue structures in some specimens suggests that no chondrified sternum was present. Archaeopteryx, the oldest and most basal known bird, isknown from only 10 specimens and the presence of a sternum is controversial; a chondrified sternum iswidely consideredtohave been present. However, data from Anchiornis and Sapeornis suggest that a sternum may also have been completely absent in this important taxon, suggesting that the absence of a sternum could represent the plesiomorphic avian condition. Our discovery reveals an unexpected level of complexity in the early evolution of the avian sternum; the large amount of observable homoplasy is probably a direct result of the high degree of inherent developmental plasticity of the sternum compared with observations in other skeletal elements.

Chen F.,Shandong University | de Aldana J.R.V.,University of Salamanca
Laser and Photonics Reviews | Year: 2014

Femtosecond-laser micromachining (also known as inscription or writing) has been developed as one of the most efficient techniques for direct three-dimensional microfabrication of transparent optical materials. In integrated photonics, by using direct writing of femtosecond/ultrafast laser pulses, optical waveguides can be produced in a wide variety of optical materials. With diverse parameters, the formed waveguides may possess different configurations. This paper focuses on crystalline dielectric materials, and is a review of the state-of-the-art in the fabrication, characterization and applications of femtosecond-laser micromachined waveguiding structures in optical crystals and ceramics. A brief outlook is presented by focusing on a few potential spotlights. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Long R.,University College Dublin | Dai Y.,Shandong University | Huang B.,Shandong University
Journal of Physical Chemistry Letters | Year: 2013

Electronic structures of C60 fullerenes interfaced with TiO 2(110) surfaces, on several types of hybrid organic/inorganic composites, have been investigated using density functional theory. For the C60/TiO2 surface, a type-II heterojunction can form but it could be inefficient because a small driving force cannot lead to efficient charge separation due to weak donor-acceptor coupling. The charge transfer from C60 to TiO2 can be enhanced by doping; however, a photoexcited electron-hole pair is expected to occur via rapid recombination. Interestingly, charge transfer can take place for both directions across an organic/inorganic interface with either a high or medium value when C 60 is covalently linked to the TiO2 surface with and without hydrogen termination. It is because a hydrogen atom alters the work function of the surface in the former case. In both cases, the strong hybridization between C 2p and Ti 3d leads to energy-level mismatch between organic and inorganic species. These observations indicate that, in a photovoltaic heterojunction based on a fullerene, the interfaces are inefficient due to either a small built-in potential or unfavorable energy band alignment. © 2013 American Chemical Society.

News Article | September 12, 2016
Site: www.materialstoday.com

A new aerogel nanomaterial that reduces the amount of noble metals, such as platinum or palladium, needed to make fuel cells should reduce the cost of such devices making them more commercially viable according to researchers in the USA and China. The aerogel could also improve efficiency. Chengzhou Zhu, Qiurong Shi, Shaofang Fu, Junhua Song, Dan Du, and Yuehe Lin of the Department of Mechanical and Materials Engineering, at Washington State University, Pullman and Haibing Xia of the State Key Laboratory of Crystal Materials, Shandong University, Jinan, have developed a rapid synthesis of aerogels that avoids the need for noble metals. The materials could find use in hydrogen-powered fuel cells as a novel component of this promising environmentally friendly energy solution for the generation of electricity. Aerogels are solids that are certainly worthy of their colloquial name of solid smoke in that they are 92 percent air by volume. They are powerful insulators and have found applications in diving wet suits, firefighting equipment and protective clothing, windows, in paints and as fuel cell catalysts. In this latter application it is the vast surface area per unit volume and high porosity that make the materials useful as catalytic components. The Washington State team has now created a series of bimetallic aerogels, that combine the relatively inexpensive transition metal copper with the precious noble metal which is needed in a smaller quantity in their aerogels. The team made the bimetallic aerogel system using their one-step, high-temperature reduction method to first create a hydrogel exploiting enhanced gelation kinetics. The hydrogel is, to all intents and purposes, the liquid-filled form of the aerogel. The liquid component can subsequently be removed by careful drying to leave behind the seemingly delicate three-dimensional network of the aerogel. The novel synthesis has reduced the standard manufacturing time of a hydrogel from three days to just six hours. "This will be a great advantage for large scale production," explains WSU's Zhu. The research was undertaken as part of WSU's Grand Challenges, a suite of research initiatives aimed at large societal issues. It is particularly relevant to the challenge of sustainable resources and its theme of energy. "The resultant PdCu aerogel with ultrathin nanowire networks exhibits excellent electrocatalytic performance toward ethanol oxidation, holding promise in fuel-cell applications," the team reports in the journal Advanced Materials [Zhu, et al., Adv. Mater. (2016) DOI: 10.1002/adma.201602546] David Bradley blogs at Sciencebase Science Blog and tweets @sciencebase, he is author of the popular science book "Deceived Wisdom".

Liu X.,University of South Australia | Xu H.,University of South Australia | Xia H.,Shandong University | Wang D.,University of South Australia
Langmuir | Year: 2012

In this report, we demonstrate a rapid and simple seeded growth method for synthesizing monodisperse, quasi-spherical, citrate-stabilized Au nanoparticles (Au NPs) via H2O2 reduction of HAuCl4. Au NPs with diameter ranging from 30 to 230 nm can be synthesized by simply adding 12 nm citrate stabilized Au NP seeds to an aqueous solution of H2O 2 and HAuCl4 under ambient conditions. The diameter of the resulting Au NPs can be quantitatively controlled by the molar ratio of HAuCl4 to the Au seeds. The standard deviation of the Au NP sizes is less than 10%, and the ellipticity (ratio of major to minor axes) of the NPs is less than 1.1. Compared to existing ones, the present seeded growth approach is implemented within 1 min under ambient condition, and no unfavorable additives are involved because H2O2 can readily decompose into H2O during storage or via boiling. © 2012 American Chemical Society.

Wang B.,CAS Lanzhou Institute of Chemical Physics | Hao J.,Shandong University | Li H.,CAS Lanzhou Institute of Chemical Physics
Dalton Transactions | Year: 2013

Versatile efforts have been made to improve the stability of graphite/ethylene glycol (EG) nanofluids. Primitively, non-dispersible graphite nanoparticles were converted to graphite oxide nanoparticles (GONs) by acid treatment. Although GONs could be well dispersed in EG, the GONs/EG nanofluids exhibited limited stability up to less than 1 day. And then, a GO (2 wt%) percolation structure formed in EG was used to anchor and support GONs by common non-covalent interactions including hydrogen bonds, van der Waals forces and π-π conjugation. Transmission electron microscopy observations revealed that a GON-GO hybrid forms in the GON-GO (2 wt%)/EG nanofluids with evenly distributed GONs on the GO sheets, which accounted for the high stability of nanofluids up to at least 4 weeks obtained from stability tests, in sharp contrast to that of the GONs/EG nanofluids. In addition, due to the better dispersed state of GONs induced by the GO percolation structure, thermal conductivity (TC) tests demonstrated that the TC enhancements of the GON-GO (2 wt%)/EG nanofluids were also strengthened compared to that of GONs/EG nanofluids. Excitingly, the GONs-GO (2 wt%)/EG nanofluids presented here exhibited anomalous thermal conductivity enhancements up to 123% at 21 wt% GONs content and were highly stable, which might have potential applications in engineering field and energy systems. © 2013 The Royal Society of Chemistry.

Zhang X.,Shandong University | Cheng K.,Shandong Polytechnic University
Journal of Coordination Chemistry | Year: 2012

Two metal-organic coordination polymers, [Co(tda)(ip)(H 2O) 2] n (1) and [Mn(tda)(ip)(H 2O)] n (2) [H 2 tda=thiophene-2,5-dicarboxylic acid, ip=1H-imidazo[4,5-f][1,10]- phenanthroline], have been synthesized and characterized by elemental analyses, IR, PXRD, and X-ray diffraction. Single-crystal X-ray analyses reveal that 2,5-tda is a bridging ligand, exhibiting two coordination modes to link metal ions: μ 1-ν 1:ν 0/μ 1- ν 1:ν 0 and μ 2-ν 1: ν 1/μ 1-ν 1:ν 0. Compound 1 demonstrates a 1-D structure in which Co 2+ centers are connected via tda anions into 1-D chains; the chains are further connected via hydrogen-bonding and interactions. Compound 2 displays a 2-D structure in which tda connects two Mn ions forming a dinuclear molecule. In 2 the 3-D supramolecular structure arrays through hydrogen-bonding and interactions. In addition, photoluminescence for 1 and 2 is also investigated in the solid state at room temperature. © 2012 Copyright Taylor and Francis Group, LLC.

Zhou S.,Shandong Jiaotong University | Zhang Y.,Shandong Green Energy Gas Industrial Co. | Dong Y.,Shandong University
Energy | Year: 2012

Stack-pretreatment is introduced to gain higher biogas production from corn stover through solid state anaerobic digestion. The purpose of this study is to find the effects of naturally microbial pretreatment on stalk lignin, cellulose and hemicellulose degradation, and biogas production. The result indicates that the corn straws which had been stack-pretreated for 20 days decreases of the content of the middle corn straws cellulose, hemi-cellulose and lignin by 5.8%, 16.8% and 5.7% respectively lower than that of the untreated samples.The highest cumulative biogas yield for 60-day digestion was obtained in B group, which was 23.2% higher than that of A group, 29.1% higher than H group and also 40.7% higher than I group. The result indicates the biogas yield of anaerobic digestion of the pretreated corn stover mixed with cow dung is higher than that of the untreated ones mixed with cow dung, and higher than that of the untreated ones alone, also higher than the cow dung alone. The biogas yield of the pretreated corn stover mixed with cow is higher than the pretreated ones with the sludge. © 2012 Elsevier Ltd.

Wang W.,Fujian Agriculture and forestry University | Wang W.,Carnegie Institution for Science | Bai M.-Y.,Carnegie Institution for Science | Bai M.-Y.,Shandong University | Wang Z.-Y.,Carnegie Institution for Science
Current Opinion in Plant Biology | Year: 2014

Many hormonal and environmental signals regulate common cellular and developmental processes in plants. While the molecular pathways that transduce these signals have each been studied in detail, how these pathways are wired into regulatory networks to provide the coordinated responses has remained an outstanding question. Recent studies of the brassinosteroid signaling network have revealed extensive signal integration through direct interactions between components of different signaling pathways. In particular, a circuit of interacting transcription regulators integrates many signaling pathways to enable coordinated and coherent regulation of seedling morphogenesis by hormonal and environmental signals. The recent studies support an emerging theme that complex networks of highly integrated signaling pathways underlie the high levels of developmental plasticity and environmental adaptability of plants. © 2014 Elsevier Ltd.

Dong R.,Shandong University | Liu W.,CAS Lanzhou Institute of Chemical Physics | Hao J.,Shandong University
Accounts of Chemical Research | Year: 2012

Vesicles of surfactants in aqueous solution have received considerable attention because of their use as simple model systems for biological membranes and their applications in various fields including colloids, pharmaceuticals, and materials. Because of their architecture, vesicles could prove useful as "soft" templates for the synthesis of "hard materials". The vesicle phase, however, has been challenging and difficult to work with in the construction of hard materials.In the solution-phase synthesis of various inorganic or macromolecular materials, templating methods provide a powerful strategy to control the size, morphology, and composition of the resulting micro- and nanostructures. In comparison with hard templates, soft templates are generally constructed using amphiphilic molecules, especially surfactants and amphiphilic polymers. These types of compounds offer advantages including the wide variety of available templates, simple fabrication processes under mild conditions, and easy removal of the templates with less damage to the final structures. Researchers have used many ordered molecular aggregates such as vesicles, micelles, liquid crystals, emulsion droplets, and lipid nanotubes as templates or structure-directing agents to control the synthesis or assembly hard micro- and nanomaterials composed from inorganic compounds or polymers. In addition to their range of sizes and morphologies, vesicles present unique structures that can simultaneously supply different microenvironments for the growth and assembly of hard materials: the inner chamber of vesicles, the outer surface of the vesicles, and the space between bilayers. Two main approaches for applying vesicles in the field of hard materials have been explored: (i) in situ synthesis of micro- or nanomaterials within a specific microenvironment by vesicle templating and (ii) the assembly or incorporation of guest materials during the formation of vesicles.This Account provides an in-depth look at the research concerning the association of soft vesicles with hard materials by our laboratory and others. We summarize three main principles of soft vesicle usage in the synthesis of hard materials and detailed procedures for vesicle templating and the characterization of the synthetic mechanisms. By use of these guiding principles, a variety of inorganic materials have been prepared, such as quantum dots, noble metal nanoparticles, mesoporous structures, and hollow capsules. Polymerization within the vesicle bilayers enhances vesicle stability, and this strategy has been developed to synthesize hollow polymer materials. Since 2004, our group has pursued a completely different strategy in the synthesis of micro- and nanomaterials using vesicles as reactive templates. In this method, the vesicles act not only as templates but also as reactive precursors. Because of the location of metal ions on the bilayer membranes, such reactions are restricted to the interface of the vesicle membrane and solution. Finally, using the perspective of soft matter chemistry, we stress some basic criteria for vesicle templating. © 2012 American Chemical Society.

Xia S.-Q.,University of Delaware | Xia S.-Q.,Shandong University | Bobev S.,University of Delaware
Chemistry of Materials | Year: 2010

Reported are structure and property studies on a series of isostructural compounds with general formulas Yb9Mn4+xSb9 (x ≈ 0.2), A9Mn4+xBi9 (A = Ca and Yb; x = 0), and the Zn-substituted derivatives Yb9(Mn,Zn)4+xSb 9 (0 < x < 0.4). They have been synthesized from the corresponding elements by high-temperature reactions, and their structures have been established by single-crystal X-ray diffraction. Despite being nearly stoichiometric phases, whose average crystallographic arrangement can be described with the orthorhombic Ca9Mn4Bi9 type structure (space group Pbam, No. 55), these ternary materials exist within narrow homogeneity ranges, whereupon an interstitial site is partially occupied by the transition metal. Electronic structure calculations confirm that the "empty" A9Mn4Sb9 or A 9Mn4Bi9 structures are electron deficient, making them suitable hosts for small dopant atoms. The expected poorly metallic behavior is evidenced from temperature-dependent resistivity data gathered from single-crystals. Magnetic susceptibility measurements in the range 2-350 K reveal complex antiferromagnetically coupled structures. These experimental results are further corroborated by theoretical calculations based on the linear muffin-tin orbital (LMTO) and the full potential linearized augmented plane wave (FP-LAPW) methods. © 2009 American Chemical Society.

Yuan X.,Shandong University | Zuo J.,University of South Australia
Journal of Cleaner Production | Year: 2013

The last decade has witnessed a growing public awareness of sustainability. The sustainability issue in higher education is no exception. This study was designed to investigate the awareness of students on sustainability and their perceptions on Higher Education for Sustainable Development. Particular focus was placed on university students' perceptions of factors that contribute towards the Higher Education for Sustainable Development. 1134 students from all divisions of the Shandong University were invited to participate in this study. The results showed that university students were generally aware of sustainability issues. The top priorities for Higher Education for Sustainable Development from the students' perceptions are generally environmentally oriented. However, students highlighted the importance of social aspects of sustainability by ranking security within the campus and providing access to disability people two of top 10 factors of Higher Education for Sustainable Development. Similarly, students perceived that students opportunities and conducting sustainability related researches as critical to Higher Education for Sustainable Development goal. On the contrary, sustainability curricula, the faculty and staff development, and rewards are perceived by students as less important compared to other factors. These research findings provide a useful reference to both the top management and educational authorities for their decision-making processes to further develop Higher Education for Sustainable Development. © 2012 Elsevier Ltd. All rights reserved.

Yuan X.,Shandong University | Zuo J.,University of South Australia
Energy Policy | Year: 2011

Energy policy plays a critical role not only in the energy development, but also in the social and environmental aspects of a nation. Five-Year Plan for National Economic and Social Development is one of the most important government plans, which documents the national strategy during that period. This study presents a critical review of 12 Five-Year Plans that have been released by the Chinese central government in last 58 years. In particular, the recently released Twelfth Five-Year Plan is reviewed. The results clearly show a pattern of increasingly level of attention of Chinese government to energy efficiency improvement, air pollutant emission reduction, new and renewable energy development, carbon dioxide emission and climate change. © 2011 Elsevier Ltd.

Yuan X.,Shandong University | Zuo J.,University of South Australia | Ma C.,Shandong University
Energy Policy | Year: 2011

Energy is essential to human beings. The increasing demand of energy has triggered the public scrutiny on the sustainability issues associated with the energy production and transmission. There have been a large number of studies focusing on reducing the environmental impacts associated with the energy sector. Renewable energy sources such as solar energy have been prompted to mitigate these environmental impacts. This research adopted a quantitative approach to investigate the social acceptance of solar energy technologies from end users' perspective in Shandong province, China. A large scale questionnaire survey was conducted. The results show that there is a considerable high level of social acceptance and public awareness of solar water heater. However, another major application of solar energy, solar PV has not gained a high level of social acceptance or public awareness in Shandong. This study provides useful references for policy makers to further promote the utilization of solar energy innovations. © 2011 Elsevier Ltd.

Yuan X.-L.,Shandong University | Zuo J.,University of South Australia
Renewable Energy | Year: 2011

The global warming and climate change have put enormous pressure on both governments and industries to re-think their attitudes and behaviours towards sustainability issues. The past decades have witnessed a number of renewable energy developments across the world. Even though these developments are not issue-free, it is generally recognized that the benefits outweigh disadvantages. However, there is an increasing level of concern on the high initial cost associated with the renewable energies, which was claimed as one of critical barriers to the promotion of its further developments. A case study approach is adopted in this study to investigate the pricing and affordability issues associated with the renewable energy in China. The policy framework and related statistics are critically reviewed in order to discuss these issues from different stakeholders' perspective in Shandong province, China. It is concluded that the affordability remains a critical issue despite numerous efforts have been made by the Chinese Government and Shandong Provincial Government on renewable power pricing. This study offers a useful reference to pricing and affordability of renewable energy. © 2010 Elsevier Ltd.

Li H.,Shandong University | Xia H.,Shandong University | Wang D.,University of South Australia | Tao X.,Shandong University
Langmuir | Year: 2013

Monodisperse, quasi-spherical silver nanocrystals (Ag NCs) have been produced directly in water via adding the aqueous solution of a mixture of AgNO3, sodium citrate, and KI into the boiling aqueous solutions of ascorbic acid (AA). The AA is used to significantly accelerate reduction of AgNO3 in order to promote a very fast nucleation, and the KI is used to tailor the growth of the Ag NCs into a quasi-spherical shape via its preferential adsorption on the NC {111} facets. The major role of citrate is to stabilize the newly formed NCs, whereas it has a minor contribution to reduction of AgNO3. The synergy of the effects of AA, citrate, and KI can significantly narrow the size distributions of the Ag NCs obtained so and transform the NC shapes to be truly quasi-spherical. © 2013 American Chemical Society.

Crowston K.,Syracuse University | Wei K.,Shandong University | Howison J.,University of Texas at Austin | Wiggins A.,Shandong University
ACM Computing Surveys | Year: 2012

We review the empirical research on Free/Libre and Open-Source Software (FLOSS) development and assess the state of the literature.We develop a framework for organizing the literature based on the input-mediatoroutput- input (IMOI) model from the small groups literature. We present a quantitative summary of articles selected for the review and then discuss findings of this literature categorized into issues pertaining to inputs (e.g., member characteristics, technology use, and project characteristics), processes (software development practices, social processes, and firm involvement practices), emergent states (e.g., social states and taskrelated states), and outputs (e.g. team performance, FLOSS implementation, and project evolution). Based on this review, we suggest topics for future research, as well as identify methodological and theoretical issues for future inquiry in this area, including issues relating to sampling and the need for more longitudinal studies. © 2012 ACM.

Feng J.-E.,Shandong University | Lam J.,University of Hong Kong | Shu Z.,National University of Ireland, Maynooth
IEEE Transactions on Automatic Control | Year: 2010

This technical note is concerned with the stabilization problem of Markovian jump linear systems via designing switching probability rate matrices and static output-feedback gains. A novel necessary and sufficient condition is established to characterize the switching probability rate matrices that guarantee the mean square stability of Markovian jump linear systems. Based on this, a necessary and sufficient condition is provided for the existence of desired controller gains and probability rate matrices. Extensions to the polytopic uncertain case are also provided. All the conditions are formulated in terms of linear matrix inequalities with some equality constraints, which can be solved by two modified cone complementarity linearization algorithms. Examples are given to show the effectiveness of the proposed method. © 2010 IEEE.

Su G.,Shandong Polytechnic University | Liu Z.,Shandong University
Wear | Year: 2012

In this paper cutting experiments of AerMet100 (52 HRC) using nano TiAlN-coated carbide tools with cutting speed from 250. m/min to 7000. m/min are carried out. The cutting tool wear characteristics under ultra-high cutting speeds are examined and the corresponding mechanisms are analyzed. The focus is put on the tool wear characteristics and mechanisms at cutting speed above 500. m/min. The influences of cutting temperature and workpiece dynamic mechanical properties on tool wear are discussed. The results show that the tool wear mechanism is highly influenced by cutting temperature and workpiece mechanical properties. At cutting speed of 500. m/min the dominate wear mechanism is micro chipping and fracture due to the cutting force vibration and cold welding of contacting materials between cutting tool and workpiece. At higher cutting speed from 1000. m/min to 7000. m/min the predominant tool wear mechanisms are abrasion, adhesion, and fracture due oxidation, and thermal softening, and grooving by hard grains. The roughness of tool flank at this cutting stage decreases with the increase of cutting speed due to the high thermal softening. The increase of workpiece material brittleness with the increase of cutting speed lowers the elastic rebound of machined surface and reduces the tool wear rate. © 2012 Elsevier B.V.

Xia H.,Shandong University | Su G.,University of South Australia | Wang D.,University of South Australia
Angewandte Chemie - International Edition | Year: 2013

Big and small, short and tall: Nanoparticles (NPs) coated with pH-sensitive polymers underwent reversible chain growth as a result of varying electrostatic interparticle repulsion as determined by the pH value. Tuning of the pH value also enabled the coupling of differently sized NPs to form linear composite chains reminiscent of block copolymers (see picture). Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Su G.,Shandong Polytechnic University | Liu Z.,Shandong University
International Journal of Advanced Manufacturing Technology | Year: 2013

Saw tooth chip is a typical characteristic encountered in high-speed machining. It consists of nearly undeformed segments and highly sheared concentrated shear bands. However, no consensus on the formation of the concentrated shear band has been reached though several saw tooth chip formation models have been built. In this paper, the concentrated shear band formation procedure is analyzed based on a new proposed saw tooth chip formation model. Cutting experiments have been conducted to validate the proposed mode. It shows that the plastic side flow and elastic compression of the uncut chip are crucial for the concentrated shear band formation. The localized shear at the inner end (tool tip side) of the primary shear plane firstly takes place under the indentation of cutting tool. Then, the second localized shear is produced at the outer end (free surface side) of the primary shear plane due to stress concentration there, after which the whole concentrated shear band forms. The stress transition at the outer end of the primary shear plane makes the second localized shear easier evolve into cracks. Influences of material brittleness and cutting speed on initiation and propagation of the concentrated shear band are also analyzed. © 2012 Springer-Verlag London Limited.

Venter H.,University of South Australia | Mowla R.,University of South Australia | Ohene-Agyei T.,University of Cambridge | Ma S.,Shandong University
Frontiers in Microbiology | Year: 2015

Drug efflux protein complexes confer multidrug resistance on bacteria by transporting a wide spectrum of structurally diverse antibiotics. Moreover, organisms can only acquire resistance in the presence of an active efflux pump. The substrate range of drug efflux pumps is not limited to antibiotics, but it also includes toxins, dyes, detergents, lipids, and molecules involved in quorum sensing; hence efflux pumps are also associated with virulence and biofilm formation. Inhibitors of efflux pumps are therefore attractive compounds to reverse multidrug resistance and to prevent the development of resistance in clinically relevant bacterial pathogens. Recent successes on the structure determination and functional analysis of the AcrB and MexB components of the AcrAB-TolC and MexAB-OprM drug efflux systems as well as the structure of the fully assembled, functional triparted AcrAB-TolC complex significantly contributed to our understanding of the mechanism of substrate transport and the options for inhibition of efflux. These data, combined with the well-developed methodologies for measuring efflux pump inhibition, could allow the rational design, and subsequent experimental verification of potential efflux pump inhibitors (EPIs). In this review we will explore how the available biochemical and structural information can be translated into the discovery and development of new compounds that could reverse drug resistance in Gram-negative pathogens. The current literature on EPIs will also be analyzed and the reasons why no compounds have yet progressed into clinical use will be explored. © 2015 Venter, Mowla, Ohene-Agyei and Ma.

Li Z.,Shandong University | Li R.,Shandong University | Mu T.,Renmin University of China | Luan Y.,Shandong University
Chemistry - A European Journal | Year: 2013

Morphology- and composition-controlled synthesis of Au-Pd bimetallic particles was realized by a facile ionic liquid assisted route at room temperature. The morphologies of the synthesized particles, such as nanoflake-constructed spheres with a core-shell structure, nanoparticle- constructed spheres, and nanoparticle-constructed dendrites, could be well controlled by the present route. The ionic liquid was found to play a key role in the formation of these interesting particles. Moreover, the composition (Au:Pd) of the particles could be modulated by means of the molar ratio of the metal precursors in the feeding solutions. The Au-Pd bimetallic particles exhibit high electrocatalytic activity toward oxidation of ethanol and formic acid. Furthermore, cyclic voltammetric studies on the as-prepared Au-Pd bimetallic particles revealed good electroactivity for H2O 2, which results in an effective amperometric H2O 2 sensor. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Zhanqiang L.,Shandong University | Guosheng S.,Shandong Polytechnic University
International Journal of Machine Tools and Manufacture | Year: 2012

To validate the correlation between chip morphology and material dynamic mechanical properties, a wide-range cutting speed (from 30 m/min to 7000 m/min) experiment is conducted with AerMet100 steel. The chips are collected and photos are taken with an optical microscope. The focus is put on workpiece material embrittlement and chip morphology evolution with the cutting speed rising. It is found that with the increase of cutting speed the workpiece material embrittles. At 7000 m/min the metal becomes completely brittle and the chip is made up of small non-plastic fractured fragments. Characteristics of the cutting temperature and cutting heat in the process are also presented. © 2011 Elsevier Ltd. All rights reserved.

Ni J.,Shandong University | Tokuda G.,University of Ryukyus
Biotechnology Advances | Year: 2013

Lignocellulose-the dry matter of plants, or "plant biomass"-digestion is of increasing interest in organismal metabolism research, specifically the conversion of biomass into biofuels. Termites efficiently decompose lignocelluloses, and studies on lignocellulolytic systems may elucidate mechanisms of efficient lignocellulose degradation in termites as well as offer novel enzyme sources, findings which have significant potential industrial applications. Recent progress in metagenomic and metatranscriptomic research has illuminated the diversity of lignocellulolytic enzymes within the termite gut. Here, we review state-of-the-art research on lignocellulose-degrading systems in termites, specifically cellulases, xylanases, and lignin modification enzymes produced by termites and their symbiotic microbiota. We also discuss recent investigations into heterologous overexpression of lignocellulolytic enzymes from termites and their symbionts. © 2013 Elsevier Inc.

Yuan X.,Shandong University | Wang X.,Shandong University | Zuo J.,University of South Australia
Renewable and Sustainable Energy Reviews | Year: 2013

Utilizing renewable energy in buildings helps to reduce consumption of conventional energy and to achieve low carbon economy. The past decades have witnessed a rapid development of renewable energy in buildings globally. China is no exception. The policies, regulations and strategic plans related to renewable energy in buildings are critically analyzed in this study with an aim to present an integrated policy framework. Furthermore, the current situation of utilizing various types of renewable energy resources in buildings and main barriers are discussed. Finally the development plan for renewable energy in buildings is presented according to the national policies. This study offers a comprehensive and systematic reference for the renewable energy in buildings in China. © 2013 Elsevier Ltd.

Shi L.,Shandong University | Li N.,Shandong Normal University | Zheng L.,Shandong University
Journal of Physical Chemistry C | Year: 2011

The aggregation behavior of long-chain N-aryl imidazolium ionic liquids (ILs), 1-(2,4,6-trimethylphenyl)-3-alkylimidazolium bromide [Cnpim]Br (n = 10, 12, 14), was investigated in a room temperature IL, 1-butyl-3-methylimidazolium tetrafluoroborate ([bmim][BF4]) by surface tension measurements. Freeze-fracture transmission electron microscopy (FF-TEM) and dynamic light scattering (DLS) measurements further verified that micelles are formed. A relatively lower critical micelle concentration (CMC) and smaller micelle size were observed compared with that of N-alkylimidazolium ILs [Cnmim]Br. The main reason for this phenomenon is that the electrostatic repulsion between the head groups of [Cnpim]Br is weakened due to the incorporation of the 2,4,6-trimethylphenyl group. The thermodynamic parameters of micelle formation of [Cnpim]Br in [bmim][BF4] were estimated from the CMC values and their temperature dependence. The micelle formation process is enthalpy-driven in the investigated temperature range, similar to the case in water. The novel N-aryl imidazolium ILs present strong fluorescence properties in [bmim][BF4], indicating their potential application in the field of photochemistry. © 2011 American Chemical Society.

Wang G.,Shandong University | Wang G.,Shandong Normal University | Yu Z.,Shandong University
Automatica | Year: 2012

This paper is concerned with a new kind of non-zero sum differential game of backward stochastic differential equations (BSDEs). It is required that the control is adapted to a sub-filtration of the filtration generated by the underlying Brownian motion. We establish a necessary condition in the form of maximum principle with Pontryagin's type for open-loop Nash equilibrium point of this type of partial information game, and then give a verification theorem which is a sufficient condition for Nash equilibrium point. The theoretical results are applied to study a partial information linear-quadratic (LQ) game and a partial information financial problem. © 2011 Elsevier Ltd. All rights reserved.

Zong W.,Shandong Normal University | Sun F.,Shandong University | Sun X.,Shandong University
Water Research | Year: 2013

The presence of microcystins (MCs) in water sources is of concern due to their direct threats to human health and potential to form oxidation by-products (OBPs) in finished water. To control the environmental risk of MCs related OBPs, we evaluated their generative mechanisms and biological toxicity by mass spectrometry technology and molecular toxicity experiment. Exposed to UV/H2O2, model toxin microcystin-LR (MCLR) in clean water was quickly transformed but successively generated seven types of MCLR-OBPs withthe chemical formulas of C49H74N10O13, C49H76N10O14, C49H78N10O16, C49H76N10O15, C37H58N10O12, C33H54N10O12, and C34H54N10O12. Probable isomers for each MCLR-OBP type were then separated and identified, indicating the aromatic ring and conjugated diene in Adda and the CC bond in Mdha were the major target sites of oxidation. Though subsequent toxicology data showed the toxicity of MCLR-OBPs on protein phosphatases 1 and 2A decreased with the extending of treatment by and large, they still possessed considerable biological toxicity (especially for product d). Influenced by MCLR-OBP distribution, concentration and residual toxicity, the secondary pollution of MCLR-OBPs in drinking water also deserved further attention even though MCLR was totally destroyed. © 2013 Elsevier Ltd.

Ge H.X.,Ningbo University | Cheng R.J.,Zhejiang University | Lei L.,Shandong University
Physica A: Statistical Mechanics and its Applications | Year: 2010

The lattice hydrodynamic model is not only a simplified version of the macroscopic hydrodynamic model, but also connected with the microscopic car following model closely. The modified Korteweg-de Vries (mKdV) equation related to the density wave in a congested traffic region has been derived near the critical point since Nagatani first proposed it. But the Korteweg-de Vries (KdV) equation near the neutral stability line has not been studied, which has been investigated in detail for the car following model. We devote ourselves to obtaining the KdV equation from the original lattice hydrodynamic models and the KdV soliton solution to describe the traffic jam. Especially, we obtain the general soliton solution of the KdV equation and the mKdV equation. We review several lattice hydrodynamic models, which were proposed recently. We compare the modified models and carry out some analysis. Numerical simulations are conducted to demonstrate the nonlinear analysis results. © 2010 Elsevier B.V. All rights reserved.

Liu L.,China University of Mining and Technology | Yang Y.,Shandong University
Superlattices and Microstructures | Year: 2013

A polyol-based precursor route was developed to synthesize MnCo complex oxide with well-defined morphologies, in which ethylene glycol (EG) was treated with metal acetates in the presence of poly(vinyl-pyrrolidone) (PVP). By varying the reaction temperature, the as-obtained precursor was readily regulated its morphologies, which could vary from nanospheres to hierarchically stacked nanoplates. The initial molar ratio of Mn-acetate to Co-acetate in EG solution played a crucial role in determining the chemical composition of the nano/microstructured precursor. On the basis of the experimental results, a possible growth mechanism for the nanostructured precursor was proposed. MnCo2O4 and CoMn2O4 could be obtained from their precursors without changing the morphologies by a simple calcination procedure. The synthetic methodology appears to be general and promises to provide an entryway into other complex oxide materials with various nano/microstructures. As an example of potential applications, the as-obtained MnCo mixed oxide nano/microstructures were used as catalyst in CO oxidation, and the effect of the morphology and composition on catalytic activities was investigated. © 2012 Elsevier Ltd. All rights reserved.

Hao W.,Taiyuan University of Technology | Zhang J.,Shandong University
Journal of Alloys and Compounds | Year: 2013

High density CaCu3Ti4O12 ceramics has been prepared by the hot-press sintering technique under ambient atmosphere. Its microstructure, crystalline structure and dielectric property are investigated and compared with those of the conventionally sintered ceramics. While the conventionally sintered ceramics show generally the theoretical relative densities lower than 95.0%, the hot-pressed one with a short sintering duration reaches the value of 99.3% and exhibits the microstructure of very uniform grain size distribution with the average large grain size of about 3 μm. X-ray diffraction analysis shows that there are Cu2O minor phases in the hot-pressed ceramics whereas no secondary phase exists after a further thermal treatment in ambience. Both the hot-pressed ceramics and its further thermally treated one exhibit two dielectric relaxations at room temperature, whereas the conventionally sintered ceramics have only one dielectric relaxation. Moreover, the hot-pressed CCTO ceramics has an extremely large low-frequency permittivity of 4.3 × 105, which further increases to nearly 2 × 106 through the ambient thermal treatment. The relation between microstructure and dielectric property is discussed. © 2013 Elsevier B.V. All rights reserved.

Bai J.,Shandong University | Li X.,Shandong University | Liu G.,Shandong University | Liu G.,Shandong Normal University | And 4 more authors.
Advanced Functional Materials | Year: 2014

A facile two-step strategy involving a polyol method and subsequent thermal annealing treatment is successfully developed for the large-scale preparation of ZnCo2O4 various hierarchical micro/nanostructures (twin mcrospheres and microcubes) without surfactant assistance. To the best of our knowledge, this is the first report on the synthesis of ZnCo2O 4 mesoporous twin microspheres and microcubes. More significantly, based on the effect of the reaction time on the morphology evolution of the precursor, a brand-new crystal growth mechanism, multistep splitting then in situ dissolution recrystallization accompanied by morphology and phase change, is first proposed to understand the formation of the 3D twin microshperes, providing new research opportunity for investigating the formation of novel micro/nanostructures. When evaluated as anode materials for lithium-ion batteries (LIBs), ZnCo2O4 hierarchical microstructures exhibit superior capacity retention, excellent cycling stability at the 5 A g-1 rate for 2000 cycles. Surprisingly, the ZnCo2O 4 twin microspheres show an exceptionally high rate capability up to the 10 A g-1 rate. It should be noted that such super-high rate performance and cycling stability at such high charge/discharge rates are significantly higher than most work previously reported on ZnCo 2O4 micro/nanostructures and ZnCo2O 4-based heterostructures. The ZnCo2O4 3D hierarchical micro/nanostructures demonstrate the great potential as negative electrode materials for high-performance LIBs. 3D hierarchical ZnCo 2O4 twin spheres are prepared via a convenient polyol process and subsequent thermal annealing. A multistep splitting in situ dissolution recrystallization originating from 1D nanorods is first proposed to understand the formation of the 3D nanoarchitectures. Lithium-ion batteries prepared with the 3D materials display remarkable performance in energy storage. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Xu Z.,Shandong University | Wang H.,Miami University Ohio
Synlett | Year: 2011

This paper describes the development of an efficient and atom-economic asymmetric inverse-electron-demand hetero-Diels-Alder reaction of six-membered ketones with β,γ-unsaturated α-keto esters via enamine-metal Lewis acid bifunctional catalysis. © Georg Thieme Verlag Stuttgart · New York.

Wang G.,Shandong Normal University | Yu Z.,Shandong University | Yu Z.,University of Évry Val d'Essonne
IEEE Transactions on Automatic Control | Year: 2010

This technical note is concerned with a maximum principle for a new class of non-zero sum stochastic differential games. The most distinguishing feature, compared with the existing literature, is that the game systems are described by backward stochastic differential equations (BSDEs). This kind of games are motivated by some interesting phenomena arising from financial markets and can be used to characterize the players with different levels of utilities. We establish a necessary condition and a sufficient condition in the form of maximum principle for open-loop equilibrium point of the foregoing games respectively. To explain the theoretical results, we use them to study a financial problem. © 2006 IEEE.

Li W.J.,Shandong University | Li W.J.,China University of Mining and Technology | Li W.J.,Arizona State University | Shao L.Y.,China University of Mining and Technology | Buseck P.R.,Arizona State University
Atmospheric Chemistry and Physics | Year: 2010

Emissions from agricultural biomass burning (ABB) in northern China have a significant impact on the regional and global climate. The monthly average aerosol optical depth (AOD) at 550 nm in northern China in 2007 had a maximum of 0.7 in June. The AOD measurements are consistent with regional brown hazes that occurred at that time, which was a period of severe aerosol pollution. Aerosol particles were collected in urban Beijing from 12 to 30 June 2007, during a period of high haze, and studied using transmission electron microscopy with energy-dispersive X-ray spectrometry. The dominant particle types collected in the fine fraction (diameter <1 μm) were ammonium sulfate, soot, K2SO4, KNO3, and organic matter, except that the K salts were minor between 21 and 30 June. K-rich particles as tracers of biomass burning, together with wildfire maps, show that intense regional ABB in northern China contributed significantly to the regional haze between 12 and 20 June. We therefore grouped the episodes into type-1 and -2 haze, with the former occurring between 12 and 20 June and the latter between 21 and 30 June. After long-range transport, ABB particles in the type-1 haze exhibited marked changes in morphology, composition, and mixing state. KCl particles were absent, presumably having been converted by heterogeneous reactions to K2SO4 and KNO3. Soot particles were mixed with the other particle types. Abundant organic matter and soluble salts emitted by ABB increased their sizes during transport and resulted in more hygroscopic aerosol particles in downwind areas, becoming additional cloud condensation nuclei. The high AOD (average value 2.2) in Beijing during 12 to 20 June is partly explained by the hygroscopic growth of fine aerosol particles and by the strong absorption of internally mixed soot particles, both coming from regional ABB emissions. Therefore, it is important to consider the origins of the haze, which in turn leads to the different particle types. © Author(s) 2010.

Chen H.,China University of Mining and Technology | Gu J.J.,Dalhousie University | Gu J.J.,Shandong University
IEEE/ASME Transactions on Mechatronics | Year: 2013

This paper describes the developed three-phase 6/8 poles switched reluctance external rotor motor drive for a fan in air conditioner. The external rotor core structure and the internal stator core structure, the three-phase windings arrangement, the slotted claw, and the setting structure of the photoelectric transducers on the rotor position detector are illustrated. The electromagnetic field calculation results are given. The three-phase asymmetric bridge power converter was used in the drive system. The block diagram of the switched reluctance external rotor motor drive with closed-loop rotor speed control is given. The closed-loop rotor speed control is implemented using a fuzzy logic algorithm. The experimental tests of the developed prototype are made for driving the fan from 200 to 950 r/min. The comparison results of the two systems show that the input power and input phase current RMS value are lower in the developed three-phase 6/8 poles external rotor switched reluctance motor drive prototype with the fan than those in the induction motor variable-frequency variable-speed drive with the fan. © 1996-2012 IEEE.

Zhan P.,Shandong University | Chen X.,Shandong University | Li D.,Shandong University | Fang Z.,Shandong University | And 2 more authors.
Medicinal Research Reviews | Year: 2013

Nonnucleoside reverse transcriptase inhibitors (NNRTIs) nowadays represent very potent and most promising anti-AIDS agents that specifically target the HIV-1 reverse transcriptase (RT). However, the effectiveness of NNRTI drugs can be hampered by rapid emergence of drug-resistant viruses and severe side effects upon long-term use. Therefore, there is an urgent need to develop novel, highly potent NNRTIs with broad spectrum antiviral activity and improved pharmacokinetic properties, and more efficient strategies that facilitate and shorten the drug discovery process would be extremely beneficial. Fortunately, the structural diversity of NNRTIs provided a wide space for novel lead discovery, and the pharmacophore similarity of NNRTIs gave valuable hints for lead discovery and optimization. More importantly, with the continued efforts in the development of computational tools and increased crystallographic information on RT/NNRTI complexes, structure-based approaches using a combination of traditional medicinal chemistry, structural biology, and computational chemistry are being used increasingly in the design of NNRTIs. First, this review covers two decades of research and development for various NNRTI families based on their chemical scaffolds, and then describes the structural similarity of NNRTIs. We have attempted to assemble a comprehensive overview of the general approaches in NNRTI lead discovery and optimization reported in the literature during the last decade. The successful applications of medicinal chemistry strategies, crystallography, and computational tools for designing novel NNRTIs are highlighted. Future directions for research are also outlined. © 2011 Wiley Periodicals, Inc.

Hou L.,Ningbo University | Qiu H.,Shandong University
Journal of Power Sources | Year: 2012

By selectively dealloying Al from Pd xCu 20-xAl 80 ternary alloys in 1.0 M NaOH solution, nanoporous PdCu (np-PdCu) alloys with different Pd:Cu ratios are obtained. By a mild electrochemical dealloying treatment, the np-PdCu alloys are facilely converted into np-PdCu near-surface alloys with a nearly pure-Pd surface and PdCu alloy core. The np-PdCu near-surface alloys are then used as substrates to fabricate core-shell catalysts with a Pt monolayer as shell and np-PdCu as core by a Cu-underpotential deposition-Pt displacement strategy. Electrochemical measurements demonstrate that the Pt monolayer on np-Pd 1Cu 1 (Pt/np-Pd 1Cu 1) exhibits the highest Pt surface-specific activity towards oxygen reduction, which is ∼5.8-fold that of state-of-the-art Pt/C catalyst. The Pt/np-Pd 1Cu 1 also shows much enhanced stability with ∼78% active surface retained after 10,000 cycles (0.6-1.2 V vs. RHE). Under the same condition, the active surface of Pt/C drops to ∼28%. © 2012 Elsevier B.V.

Liu S.,Shandong University | Zhang X.,Shandong University | Yu Y.,Beijing University of Chemical Technology | Zou G.,Shandong University
Analytical Chemistry | Year: 2014

A promising electrochemiluminescence (ECL) sensing strategy was proposed with dual-stabilizers-capped CdSe quantum dots (QDs) as ECL emitters. The dual-stabilizers-capped CdSe QDs were covalently immobilized onto p-aminobenzoic acid modified glass carbon electrode with ethylenediamine as a link molecule. This strategy can preserve the completely passivated surface states of dual-stabilizers-capped CdSe QDs, so that the sensor demonstrated eye-visible greenish, band gap engineering and monochromatic ECL emission at 546 nm with a fwhm of 35 nm. Moreover, the proposed sensor could accurately quantify dopamine from 10.0 nM to 3.0 μM with a detection limit of 3.0 nM in practical drug, human urine, and cerebrospinal fluid samples without any signal amplification techniques. This strategy is promising for developing ECL sensors with high sensitivity and spectral selectivity. © 2014 American Chemical Society.

Li H.,Shandong University | Liu Y.,Shandong Normal University
Computers and Mathematics with Applications | Year: 2011

In this paper, we obtain the existence of sign-changing solutions for nonlinear second-order differential equations with integral boundary value conditions, by applying a new fixed point theorem in ordered Banach spaces, with the lattice structure derived by Liu and Sun. Our results improve on those in the literature. © 2011 Elsevier Ltd. All rights reserved.

News Article
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Laser applications may benefit from crystal research by scientists at the National Institute of Standards and Technology (NIST), Gaithersburg, Md., and China's Shandong University. They discovered a potential way to sidestep longstanding difficulties with making the crystals that are a crucial part of laser technology. But the science behind their discovery has experts scratching their heads. Findings suggest that the relatively large crystals used to change several properties of light in lasers—changes that are crucial for making lasers into practical tools—might be created by stacking up far smaller, rod-shaped microcrystals that can be grown easily and inexpensively. So far, the team's microcrystals outperform conventional crystals in some ways, suggesting that harnessing them could signal the end of a long search for a fast, economical way to develop large crystals that would otherwise be prohibitively expensive and time-consuming to create. But the microcrystals also challenge conventional scientific theory as to why they perform as they do. The color seen in a laser's light is often different than the one it initially generates. Many lasers create infrared light, which then passes through a crystal converting its energy—and therefore its wavelength—to light of a visible color like green or blue. Frequently, that crystal is made of potassium diphosphate (KDP), a common material that has properties that make it invaluable: Not only can a KDP crystal alter the light's color, but it also can act as a switch that changes the light's polarization (the direction in which its electric field vibrates) or prevent it from passing through the crystal until just the right moment. The data carried by laser light through fiber-optic cables depends on the light's polarization, and many applications depend on a laser pulse's timing. Small KDP crystals are easy to make, and these find use in pocket laser pointers and telecommunications systems alike. But for higher-energy applications, scientists have searched for decades for a way to make large, high-quality crystals that can survive repeated exposure to intense laser pulses, but a solution has remained elusive. The team found useful results by growing KDP crystals in solution. These crystals take the form of hexagonal-shaped hollow tubes and long rods just a few micrometers wide. Individually, these KDP microcrystals have an energy-conversion efficiency surpassing even the best KDP crystals under the same conditions, raising the possibility of directly growing crystals for use in telecommunications. The team also suggests the rods could be stacked up like firewood, building a larger piece out of billions of the tiny filaments. Before they are stacked together they could be coated by a thin layer of conductive material that carries heat away, rendering them capable of handling repeated pulses of high-intensity laser light—potentially broadening their application range if a way can be found to stack them. The mystery is why the microcrystals perform as they do. Basic physics says they shouldn't. Conventional physics models indicate that an optical medium like a crystal must not be symmetric about its center if it is to convert energy efficiently, yet these microcrystals appear to break this rule. "We've spoken to a number of experts in different fields worldwide, and none of them can explain it," says NIST physicist Lu Deng. "Currently no theory can explain the initial growth mechanism of this exotic crystal. It's challenging our current understanding in fields from crystallography to condensed matter physics." While theory catches up with data, Deng says the team is concentrating on the engineering challenges of growing stackable microcrystal rods. "We can grow more than 1000 microstructures every 10 minutes or so on a single glass slide, so growing a large amount is not a problem," he says. "What we need to figure out is how to grow a large fraction of them with nearly uniform cross-sections as that will be important in the final assembly stage." Image caption — Potassium diphosphate (KDP) crystals, which self-assemble in solution as hollow hexagonal rods, could find use in laser technology, particularly for fiber-optic communications. The scanning-electron image at right shows a crystal at higher resolution with scale added. Courtesy of L. Deng/NIST.

Yuan D.,Texas A&M University | Zhao D.,Texas A&M University | Sun D.,Shandong University | Zhou H.-C.,Texas A&M University
Angewandte Chemie - International Edition | Year: 2010

(Figure Presented) Holding gas: One of the isoreticular metal-organic frameworks (MOFs) that have been synthesized and characterized structurally, PCN-68 (see structure), has a Langmuir surface area of as high as 6033 m 2 g-1. The MOFs also display excellent gas (H2, CH4, and CO2) adsorption capacity. © 2010 Wiley-vCH Verlag GmbH & Co. KGaA.

Xin B.,Shandong University | Xin B.,Dezhou University | Hao J.,Shandong University
Chemical Society Reviews | Year: 2014

Supported ionic liquids (SILs), which refer to ionic liquids (ILs) immobilized on supports, are among the most important derivatives of ILs. The immobilization process of ILs can transfer their desired properties to substrates. Combination of the advantages of ILs with those of support materials will derive novel performances while retaining properties of both moieties. SILs have been widely applied in almost all of fields involving ILs, and have brought about drastic expansion of the ionic liquid area. As green media in organic catalytic reactions, based on utilizing the ability of ILs to stabilize the catalysts, they have many advantages over free ILs, including avoiding the leaching of ILs, reducing their amount, and improving the recoverability and reusability of both themselves and catalysts. This has critical significance from both environmental and economical points of view. As novel functional materials in surface science and material chemistry, SILs are ideal surface modifying agents. They can modify and improve the properties of solids, such as wettability, lubricating property, separation efficiency and electrochemical response. With the achievements in the field of ILs, using magnetic nanoparticles (MNPs) to SILs has drawn increasing attention in catalytic reactions and separation technologies, and achieved substantial progress. The combination of MNPs and ILs renders magnetic SILs, which exhibit the unique properties of ILs as well as facile separation by an external magnetic field. In this article, we focus on imidazolium-based ILs covalently grafted to non-porous and porous inorganic materials. The excellent stability and durability of this kind of SILs offer a great advantage compared with free ILs and IL films physically adsorbed on substrates without covalent bonds. Including examples from our own research, we overview mainly the applications and achievements of covalent-linked SILs in catalytic reactions, surface modification, separation technologies and electrochemistry. This journal is © the Partner Organisations 2014.

Tian J.,Shandong University | Zhao Z.,Shandong University | Kumar A.,CAS Beijing Institute of Nanoenergy and Nanosystems | Boughton R.I.,Bowling Green State University | And 2 more authors.
Chemical Society Reviews | Year: 2014

One-dimensional TiO2 nanostructured surface heterostructures (1D TiO2NSHs) have been comprehensively studied during the past two decades because of the possible practical applications in various fields, including photocatalysis, dye-sensitized solar cells, sensors, lithium batteries, biomedicine, catalysis, and supercapacitors. Combining extensive advancements in materials science and nanotechnology, a 1D TiO2NSH material with well-controlled size, morphology, and composition has been designed and synthesized. More importantly, its superior properties, including a high aspect ratio structure, chemical stability, large specific surface area, excellent electronic or ionic charge transfer, and a specific interface effect, have attracted a great deal of interest in improving current performance and exploring new applications. In this tutorial review, we introduce the characteristics of 1D TiO2 nanostructures, the design principles for the fabrication of 1D TiO2NSHs, and we also summarize the recent progress in developing synthesis methods and applications of 1D TiO2NSHs in different fields. The relationship between the secondary phase and the 1D TiO2 nanostructure and between the performance in applications and the excellent physical properties of 1D TiO2NSHs are also discussed. This journal is © the Partner Organisations 2014.

Wu J.-W.,Dezhou University | Wu J.-W.,Shandong University | Chen X.-L.,Shandong University
Applied Microbiology and Biotechnology | Year: 2011

Bacterial extracellular metalloproteases (BEMPs) are a large group of metal-containing proteases secreted by heterotrophic bacteria. In this review, the diversity, structural characteristics, mechanisms ofmaturation, physiological roles, and applications of BEMPs are described. BEMPs are distributed among nine families of metalloproteases because of differences in primary sequences and structural characteristics. Until now, all of the BEMPs identified have been endoproteases harboring one catalytic Zn2+ in the active centers. BEMPs are usually synthesized as inactive zymogens with a propeptide that is covalently linked to and inhibits the catalytic domain. The removal of the propeptides of BEMPs is dependent on other proteases or an autocleavage process. The main physiological function of BEMPs is to degrade environmental proteins and peptides for bacterial heterotrophic nutrition. As extracellular proteases, BEMPs vary greatly in enzymology properties to adapt to their respective environments. BEMPs have been widely used in the food and pharmaceutical industries. In order to broaden the application of BEMPs, it is essential to explore novel BEMPs and apply gene/protein engineering to improve the production and properties of promising BEMPs. © Springer-Verlag 2011.

Xu C.,Chinese University of Hong Kong | Xu C.,Shandong University | Cheng Z.,CAS Institute of Genetics and Developmental Biology | Yu W.,Chinese University of Hong Kong
Plant Journal | Year: 2012

Telomere truncation has been shown to be an efficient technology for the creation of mini-chromosomes that can be used as artificial chromosome platforms for genetic engineering. Artificial chromosome-based genetic engineering is considered to be superior to the existing techniques of randomized gene integration by Agrobacterium or biolistic-mediated genetic transformation. It organizes multiple transgenes as a unique genetic linkage block for subsequent manipulations in breeding. Telomere truncation technology relies on three components: the telomere sequence that mediates chromosomal truncation, a selection marker that allows the selection of transgenic events, and a site-specific recombination system that can be used to accept future genes into the mini-chromosome by gene targeting. These elements are usually pre-assembled before transformation, a process that is both time and labor consuming. We found in this research that the three elements could be mixed to transform plant cells in a biolistic transformation, and produced efficient chromosomal truncations and mini-chromosomes in rice. This system will allow rapid construction of mini-chromosomes with a flexible selection of resistant markers, site-specific recombination systems and other desirable elements. In addition, a rice telotrisomic line was used as the starting material for chromosomal truncations. Mini-chromosomes from the truncations of both the telocentric chromosome and other chromosomes were recovered. The mini-chromosomes remained stable during 2 years of subculture. The construction of mini-chromosomes in rice, an economically important crop, will provide a platform for future artificial chromosome-based genetic engineering of rice for stacking multiple genes. © 2012 Blackwell Publishing Ltd.

Qin Q.,Shandong University | Qin Q.,Shandong Academy of Sciences | Wei F.,Shandong Academy of Sciences | Li B.,Shandong University | Li B.,Shandong Academy of Sciences
Journal of Experimental and Clinical Cancer Research | Year: 2014

MicroRNAs (miRNAs) are small noncoding RNAs that regulate gene expression post-transcriptionally. miRNAs can be induced by a variety of stresses such as hypoxia, and are involved in diverse biological processes including differentiation, cell proliferation, cell death, and tumorigenesis. Hypoxia, a common feature of tumor microenvironment, can induce a number of miRNAs expression. miRNA-210 (miR-210) is one of the hypoxia-regulated-miRNAs, which has been investigated extensively in cancer. However, paradoxically opposing results were documented regarding whether it is an oncogene or a tumor suppressor, and whether it is a positive or negative prognostic biomarker. In the present review, we focus on the following investigations of miR-210: 1) its functions of as an oncogene, 2) its functions as a tumor suppressor, 3) its functions in mitochondrial metabolism, and finally, the diagnostic and prognostic value of miR-210 in cancer researches. © 2014 Qin et al.; licensee BioMed Central Ltd.

Zhang G.,Shandong University | Hou X.,Shandong University | Li Y.,Weihai Municipal Hospital | Zhao M.,11 Health
BMC Cancer | Year: 2014

Background: MicroRNAs (miRNAs) are frequently dysregulated in human cancers and can act as either potent oncogenes or tumor suppressor genes. In the present study, we intend to prove that the gene PTEN (phosphatase and tensin homolog deleted on chromosome ten) is a target gene of miR-205 and to investigate the suppressive effects on PTEN transcriptional activity by enhancing miR-205 expression in endometrial cancer Ishikawa cells.Methods: Using Ishikawa cells as model systems, we up-regulated miR-205 expression by transient transfection with miR-205 mimics. A luciferase reporter assay, qRT-PCR and western blotting assays were used to verify whether PTEN is a direct target of miR-205. Meanwhile, the modulatory role of miR-205 in the AKT (protein kinase B) pathway was evaluated by determining the AKT phosphorylation. As a biological counterpart, we investigated cell apoptosis using flow cytometry.Results: Our data indicate that miR-205 down-regulates the expression of PTEN through direct interaction with the putative binding site in the 3'-untranslated region (3'-UTR) of PTEN. Moreover, we documented the functional interactions of miR-205 and PTEN, which have a downstream effect on the regulation of the AKT pathway, explaining, at least in part, the inhibitory effects on Ishikawa cell apoptosis of enhancing miR-205 expression.Conclusions: For the first time, we demonstrate that the expression of PTEN is directly regulated by miR-205 in endometrial cancer cells and leads the inhibition of cellular apoptosis. This relationship could be targeted for new therapeutic strategies for endometrial cancer. © 2014 Zhang et al.; licensee BioMed Central Ltd.

Niu P.,Shandong University | Niu P.,Dezhou University | Hao J.,Shandong University
Langmuir | Year: 2011

Photocatalytic multilayer films with different numbers of bilayers were prepared via an electrostatic layer-by-layer (LbL) self-assembly method. These LbL films were characterized by UV-vis spectroscopy, atomic force microscopy (AFM), and X-ray photoelectron spectroscopy (XPS). Our results indicate that TiO2 and tungstophosphate (H3PW12O 40, abbreviated as PW12) are successfully incorporated into the thin films. The as-prepared (TiO2/PW12) n films show good photocatalytic performance toward methyl orange (MO) solution at pH 2.0, which is attributed to the synergistic effect between TiO2 and PW12. The effect of experimental parameters including number of bilayers, initial concentration, and pH value of dye solution were also studied. The multilayer films can be easily recovered and reused several times with little change of degradation, indicating that they are stable under the ultraviolet (UV) irradiation. The detection of active species displays that active holes (h+) play a dominant role for MO photodegradation in the TiO2/PW12 system. Taking advantage of immobilization of catalysts on glass slides, the problem of recovery is solved. It is expected that photocatalytic multilayer films have substantial applications in industry. © 2011 American Chemical Society.

Xie Y.,University of Nebraska - Lincoln | Wright S.,University of Nebraska - Lincoln | Shen Y.,Shandong University | Du L.,University of Nebraska - Lincoln | Du L.,Shandong University
Natural Product Reports | Year: 2012

Covering: up to March 2012 The gliding Gram-negative Lysobacter bacteria are emerging as a promising source of new bioactive natural products. These ubiquitous freshwater and soil microorganisms are fast growing, simple to use and maintain, and genetically amenable for biosynthetic engineering. This Highlight reviews a group of biologically active and structurally distinct natural products from the genus Lysobacter, with a focus on their biosyntheses. Although Lysobacter sp. are known as prolific producers of bioactive natural products, detailed molecular mechanistic studies of their enzymatic assembly have been surprisingly scarce. We hope to provide a snapshot of the important work done on the lysobacterial natural products and to provide useful information for future biosynthetic engineering of novel antibiotics in Lysobacter. © 2012 The Royal Society of Chemistry.

Zhu W.-X.,Shandong University | Yu R.-L.,Shandong University | Yu R.-L.,Dezhou University
Physica A: Statistical Mechanics and its Applications | Year: 2014

A novel car-following model was proposed to describe the motion of the vehicles on a single lane gyroidal road. We explore the related effects of gyroidal road upon uniform traffic flow analytically and numerically. The analytical result shows that the related factors of gyroidal road including the friction coefficient, radius of curvature and slope have great influences on the stability of the uniform flow respectively. The modified KdV (Korteweg-de Vries) equation is derived in the unstable area and the kink solution is obtained near the critical point. A series of simulations are conducted to verify the effects upon uniform traffic flow under different road conditions. It is shown that the amplitudes of the headway oscillation wave were affected by the friction coefficient, radius of curvature and slope respectively. The numerical results are in good agreement with the analytical results. © 2013 Elsevier B.V. All rights reserved.

Lu T.,Texas A&M University | Zhu R.,Texas A&M University | Zhu R.,Shandong University | An Y.,Texas A&M University | Wheeler S.E.,Texas A&M University
Journal of the American Chemical Society | Year: 2012

The enantioselective propargylation of aromatic aldehydes with allenyltrichlorosilanes catalyzed by bipyridine N-oxides was explored using density functional theory. Low-lying transition states for a highly enantioselective helical bipyridine N-oxide catalyst [Org. Lett. 2011, 13, 1654] were characterized at the B97-D/TZV(2d,2p) level of theory. Predicted free energy barrier height differences are in agreement with experimental ees for the propargylation of benzaldehyde and substituted analogues. The origin of enantioselectivity was pinpointed through distortion-interaction analyses. The stereoselectivity arises in part from through-space electrostatic interactions of the carbonyl carbon with the Cl ligands bound to Si, rather than noncovalent aryl-aryl interactions between the aromatic aldehyde and the helix as previously proposed. Moreover, aryl-aryl interactions between the aldehyde and helix are predicted to favor transition states leading to the R enantiomer, and ultimately reduce the enantioselectivity of this reaction. (S)-2,2′-bipyridine N-oxide was studied as a model catalyst in order to quantify the inherent enantioselectivity arising from different chiral arrangements of ligands around the hexacoordinate silicon in the stereocontrolling transition state for these reactions. The predicted selectivities arising from different chiral octahedral silicon complexes provide guidelines for the development of transition state models for N-oxide-based alkylation catalysts. © 2012 American Chemical Society.

Zhu W.-X.,Shandong University | Yu R.-L.,Shandong University | Yu R.-L.,Dezhou University
Physica A: Statistical Mechanics and its Applications | Year: 2012

We investigate the slope effects upon traffic flow on a single lane gradient (uphill/downhill) highway analytically and numerically. The stability condition, neutral stability condition and instability condition are obtained by the use of linear stability theory. It is found that stability of traffic flow on the gradient varies with the slopes. The Burgers, Kortewegde Vries (KdV) and modified Kortewegde Vries (mKdV) equations are derived to describe the triangular shock waves, soliton waves and kinkantikink waves in the stable, meta-stable and unstable region respectively. A series of simulations are carried out to reproduce the triangular shock waves, kinkantikink waves and soliton waves. Results show that amplitudes of the triangular shock waves and kinkantikink waves vary with the slopes, the soliton wave appears in an upward form when the average headway is less than the safety distance and a downward form when the average headway is more than the safety distance. Moreover both the kinkantikink waves and the solitary waves propagate backwards. The numerical simulation shows a good agreement with the analytical result. © 2011 Elsevier B.V. All rights reserved.

This article proposes a linear programming model that is based on the wastewater treatment input-output model (W2IO) to identify the lowest-emission choice among alternative feasible options for wastewater treatment; this model can be considered as an application of the waste input-output linear programming model (WIO-LP) to wastewater issues. Using the data of the Tokyo metropolitan W2IO table, I apply this model to obtain the optimal wastewater treatment options under alternative scenarios. The Pareto frontiers of environmental loads are derived to show the trade-off relationships among various types of environmental load and the effect of the introduction of high-temperature incineration of dewatered sludge on the generation of environmental loads. The main conclusion of the study is that when all three types of environmental load (landfill level, global warming potential, and chemical oxygen demand) are considered, the introduction of high-temperature incineration causes the widening of the Pareto frontier of environmental loads and also causes it to move closer to the origin. © 2011 by Yale University.

Dai P.,Boston College | Xie J.,Boston College | Mayer M.T.,Boston College | Yang X.,Boston College | And 2 more authors.
Angewandte Chemie - International Edition | Year: 2013

Covered with Pt: A uniform catalyst profile that ensures effective radial charge collection from high-aspect-ratio Si nanowires was achieved by atomic layer deposition of Pt nanoparticles. The resulting photoelectrode permits the measurement of high photovoltages and low overpotentials, and leads to very good stability against photooxidation of Si nanowires in solar water-reduction reactions. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Deguire S.M.,Vanderbilt University | Ma S.,Shandong University | Sulikowski G.A.,Vanderbilt University
Angewandte Chemie - International Edition | Year: 2011

By design: A carbanion-mediated cyclization reaction cascade serves as the key final step in the total synthesis of a novel oxylipin, which features a strained bicyclo[1.1.0]butane conjugated to a labile vinyl epoxide. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Chen C.,Shandong University | Zhou J.,Zenith Diagnostic Consultants | Ji C.,Shandong University
Life Sciences | Year: 2010

This review centers on recent findings with respect to modulating cancer multidrug resistance (MDR) with the well-known flavonoid quercetin. After a short introduction of quercetin, major in vitro and in vivo findings are summarized showing that quercetin is a MDR modulator and thus a potential chemosensitizer. Finally, we contemplate future prospects of modulating MDR in the clinic. © 2010 Elsevier Inc.

Yip W.C.-M.,University of Oxford | Hsiao W.,Harvard University | Meng Q.,Shandong University | Chen W.,Fudan University | Sun X.,Pudong Health Authority
The Lancet | Year: 2010

Inappropriate incentives as part of China's fee-for-service payment system have resulted in rapid cost increase, inefficiencies, poor quality, unaffordable health care, and an erosion of medical ethics. To reverse these outcomes, a strategy of experimentation to realign incentives for providers with the social goals of improvement in quality and efficiency has been initiated in China. This Review shows how lessons that have been learned from international experiences have been improved further in China by realignment of the incentives for providers towards prevention and primary care, and incorporation of a treatment protocol for hospital services. Although many experiments are new, preliminary evidence suggests a potential to produce savings in costs. However, because these experiments have not been scientifically assessed in China, evidence of their effects on quality and health outcome is largely missing. Although a reform of the provider's payment can be an effective short-term strategy, professional ethics need to be re-established and incentives changed to alter the profit motives of Chinese hospitals and physicians alike. When hospitals are given incentives to achieve maximum profit, incentives for hospitals and physicians must be separated. © 2010 Elsevier Ltd. All rights reserved.

Wang R.,Shandong University | Wang C.,Fudan University | Cai W.-B.,Fudan University | Ding Y.,Shandong University
Advanced Materials | Year: 2010

A robust new electrocatalyst with ultralow Pt loading, great poisoning resistance, and high stability (see figure) shows an over 100-fold increase in the efficiency of formic acid electro-oxidation, compared with the commercial Pt/C catalyst. In situ IR spectroscopy proves that the greatly enhanced performance is mainly achieved by changing reaction pathways using Au clusters, which simultaneously improve the stability. (Fig. Represented). © 2010 WILEY-VCH Verlag GmbH & Co. KGaA.

Meng F.,Shandong University | Ding Y.,Shandong University | Ding Y.,Shandong Applied Research Center for Gold Technology Au
Advanced Materials | Year: 2011

A sub-micrometer-thick, flexible, all-solid-state supercapacitor is fabricated. Through simultaneous realization of high dispersity of pseudocapacitance materials and quick electrode response, the hybrid nanostructures show enhanced volumetric capacitance and excellent stability, as well as very high power and energy densities. This suggests their potential as next-generation, high-performance energy conversion and storage devices for wearable electronics. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Dong G.Y.,Shandong Jianzhu University | Yang X.L.,Shandong University | Cai L.Z.,Shandong University
Optics Express | Year: 2010

We have investigated for the first time the anomalous refractive effects of a photonic crystal (PhC) formed by holographic lithography (HL) with triangular rods arranged in a honeycomb lattice in air. Possibilities of left-handed negative refraction and superlens are discussed for the case of TM2 band with the index contrast n = 3.4:1. In contrast to the conventional honeycomb PhC made of regular rods in air, the HL PhCs show left-handed negative refraction over a wider and higher frequency range with high transmissivity (>90%), and the effective indices quite close to-1 for a wide range of incident angles with a larger all-angle left-handed negative refraction (AALNR) frequency range (Δω/ω ≈14.8%). Calculations and FDTD simulations demonstrate the high-performance negative refraction properties can happen in the holographic structures for a wide filling ratio and can be modulated by changing the filling ratio easily. © 2010 Optical Society of America.

Zhu Q.,Shandong University | Han C.C.,CAS Beijing National Laboratory for Molecular
Polymer | Year: 2010

Well architectured polyurethanes containing fluorine are expected to be applied in medical devices as well as other fields. A telechelic polyurethane end-capped with perfluoropolyether segments was prepared from polyether glycol as a soft segment, 4, 4′-methylene-bis-(phenylisocyanate), and monofunctional perfluorinated oligomer. The telechelic polyurethane was studied by Fourier transform infrared spectroscopy (FTIR), gel permeation chromatography (GPC), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS), contact angle and atomic force microscopy (AFM). XPS results indicated that the surface of the fluorine containing polyurethane was enriched with fluorine component. It exhibited a hydrophobic property with a water contact angle of 113°. The polyurethane terminated with perfluoropolyether segments showed a better thermal stability. A mechanism was proposed to explain thermal decomposition of polyurethanes. DSC results suggested that the tail-like perfluoropolyether segments would disrupt main chain packing, then raise crystallization potential barrier, and the perfluoropolyether segments did not affect the bulk microphase-separated structure. © 2010 Elsevier Ltd. All rights reserved.

Li B.,Shandong University | Habbal S.R.,University of Hawaii at Manoa | Chen Y.,Shandong University
Astrophysical Journal | Year: 2013

In the applications of solar magneto-seismology, the ratio of the period of the fundamental mode to twice the period of its first overtone, P 1/2P 2, plays an important role. We examine how field-aligned flows affect the dispersion properties, and hence the period ratios, of standing modes supported by magnetic slabs in the solar atmosphere. We numerically solve the dispersion relations and devise a graphic means to construct standing modes. For coronal slabs, we find that the flow effects are significant for the fast kink and sausage modes alike. For the kink ones, they may reduce P 1/2P 2 by up to 23% compared with the static case, and the minimum allowed P 1/2P 2 can fall below the lower limit analytically derived for static slabs. For the sausage modes, while introducing the flow reduces P 1/2P 2 by typically ≲ 5% relative to the static case, it significantly increases the threshold aspect ratio only above which standing sausage modes can be supported, meaning that their detectability is restricted to even wider slabs. In the case of photospheric slabs, the flow effect is not as strong. However, standing modes are distinct from the coronal case in that standing kink modes show a P 1/2P 2 that deviates from unity even for a zero-width slab, while standing sausage modes no longer suffer from a threshold aspect ratio. We conclude that transverse structuring in plasma density and flow speed should be considered in seismological applications of multiple periodicities to solar atmospheric structures. © 2013. The American Astronomical Society. All rights reserved.

Zhao P.,Shandong University | Zhang C.-Q.,West Virginia University
Pattern Recognition Letters | Year: 2011

In a graph theory model, clustering is the process of division of vertices into groups, with a higher density of edges within groups than between them. In this paper, we introduce a new clustering method for detecting such groups and use it to analyse some classic social networks. The new method has two distinguished features: non-binary hierarchical tree and the feature of overlapping clustering. A non-binary hierarchical tree is much smaller than the binary-trees constructed by most traditional methods and, therefore, it clearly highlights meaningful clusters which significantly reduces further manual efforts for cluster selections. The present method is tested by several bench mark data sets for which the community structure was known beforehand and the results indicate that it is a sensitive and accurate method for extracting community structure from social networks. © 2011 Elsevier B.V. All rights reserved.

Li X.,Shandong University | Li J.,Liaocheng Peoples Hospital
Mini-Reviews in Medicinal Chemistry | Year: 2010

Pyrrolidine scaffold has been widely used to design a variety of N-heterocyclic derivatives towards various targets. Amongst them, matrix metalloproteins (MMPs) and aminopeptidase N (APN) represent two kinds of important metalloproteinase targets which have been proved to be tightly related to tumor proliferation, invasion, metastasis and angiogenesis. As a result, their respective inhibitors, namely MMP inhibitors (MMPIs) and APN inhibitors (APNIs), have been systematically studied in our group for many years. Recent advances in the elucidation of MMPIs and APNIs based on the pyrrolidine platforms are briefly reviewed in this paper. © 2010 Bentham Science Publishers Ltd.

Liu F.,Tongji University | Liu F.,Shandong University | Xu J.,Tongji University | Yang Y.,Tongji University
Journal of the Optical Society of America B: Optical Physics | Year: 2014

Based on the special electromagnetic properties of a 3D strong topological insulator (TI), we discuss, theoretically, the reflection of electromagnetic wave at the interface between a dielectric and a TI, and focus on the polarization conversion between the incident field and reflected field. Two cases, linear polarization and elliptical polarization at oblique incidence are considered. We derive the conditions required for the complete polarization conversion from incident s polarization into reflected p polarization, and vice versa. Furthermore, elliptical polarization incidence also can be modulated to linear or circular polarization after reflection, under special conditions, and the corresponding reflectivity can approach 1. All these special polarization behaviors originate from the intrinsic topological magnetoelectric coupling response in TI. This work provides promising applications of TIs on polarized devices and the polarization splitters. © 2014 Optical Society of America.

Sun D.,Shandong University | Yan Z.-H.,Shandong University | Blatov V.A.,Samara State University | Wang L.,Shandong University | Sun D.-F.,Shandong University
Crystal Growth and Design | Year: 2013

Solvothermal reactions of the tripodal ligand 1,3,5-tris(1-imidazolyl)- benzene (tib) and different polycarboxylates with zinc nitrate provided six new zinc(II) coordination polymers (CPs), namely, {[Zn8(tib) 5(bdc)8(H2O)]·7DMF·18H 2O}n (1), {[Zn3(tib)2(bpdc) 3 ] ·5H2O}n (2) , {[Zn(tib)(pdac)] ·1.5H2O}n (3) , {[Zn6(tib) 2(pdac)3]·DMA·2H2O}n (4), {[Zn2(tib)2(pma)]·4H2O}n (5), {[Zn2(tib)- (Htib)(H2pma)(Hpma)]·2H2O}n (6) (H2bdc = 1,3-benzenedicarboxylic acid, H2bpdc = 4,4'-biphenyldicarboxylic acid, H2pdac = 1,2-phenylenediacetic acid, H4pma = pyromellitic acid, DMF = N,N'-dimenthylformamide, DMA = N,N'-dimethylacetamide). All of the complexes have been structurally characterized by single-crystal X-ray diffraction analyses and further characterized by infrared spectra (IR), elemental analyses, powder X-ray diffraction (PXRD), and thermogravimetric analyses (TGA). Single crystal X-ray diffraction analysis reveals that complex 1 exhibits a complicated self-catenating three-dimensional (3D) framework that could be decomposed to two interpenetrating (4,6)-coordinated sun1 nets with point symbol of {3·4·64}{3·46·5 2·64·72}2. Complex 2 is a 2-fold interpenetrating (3,4)-coordinated new topology sun2 with point symbol of {103}2{106}3. In complex 3, both the tib and pdac act as a bidentate bridging ligand and extend the tetrahedral Zn(II) centers to an interesting one-dimensional (1D) independent single-wall metal-organic nanotube (SWMONT). Differently, the tib and pdac become tridentate and bidentate linkers in complex 4, respectively, which extend the Zn(II) centers to the resulting 2-fold interpenetrating (3,4)-coordinated network with a srd topology and the point symbol is {63} 2{64·92}3. Complex 5 is a (3,4)-coordinated self-penetrating network sun3 with point symbol of {10 3}{106}. This net could be further decomposed to two interpenetrating 3-coordinated 103 srs (SrSi2) subnets by omitting the 2-coordinated pma linker, while complex 6 shows an undulated 2D 3,3L4 layer, which is interdigitated with each other to form a 3D supramoleular framework stabilized by hydrogen bonds. The structural and topological differences of the six CPs indicate that the auxiliary polycarboxylates and solvents play important roles in the formation of the final structures. Furthermore, the thermal stability and photoluminescence properties of the complexes were investigated. © 2013 American Chemical Society.

Zhang Y.-T.,Shandong University | Cui S.-Y.,Ludong University
Physics of Plasmas | Year: 2011

In this paper, a one-dimensional model is explored to investigate the frequency effects on the characteristics of atmospheric radio frequency discharges at a given power. The simulation data and analytical results show that the improvement of electron density can be observed with better discharge stability by increasing excitation frequency in an appropriate range. Using the analytical equations deduced from the model, the mean electron density could be inferred by means of the measured parameters. The - mode transition especially in high frequency discharges is also analytically discussed based on the theoretical equations. © 2011 American Institute of Physics.

Zhang H.,Gothenburg University | Liu L.,Shandong University | Li X.,Gothenburg University | Busayavalasa K.,Gothenburg University | And 4 more authors.
Proceedings of the National Academy of Sciences of the United States of America | Year: 2014

Whether or not oocyte regeneration occurs in adult life has been the subject of much debate. In this study, we have traced germcell lineages over the life spans of three genetically modified mouse models and provide direct evidence that oogenesis does not originate from any germline stem cells (GSCs) in adult mice. By selective ablation of all existing oocytes in a Gdf9-Cre;iDTR mouse model, we have demonstrated that no new germ cells were ever regenerated under pathological conditions. By in vivo tracing of oocytes and follicles in the Sohlh1-CreERT2;R26R and Foxl2-CreERT2;mT/mG mouse models, respectively, we have shown that the initial pool of oocytes is the only source of germ cells throughout the life span of the mice and that no adult oogenesis ever occurs under physiological conditions. Our findings clearly show that there are no GSCs that contribute to adult oogenesis in mice and that the initial pool of oocytes formed in early life is the only source of germ cells throughout the entire reproductive life span.

Hu F.,CAS Beijing National Laboratory for Molecular | Hu F.,Shandong University | Xia Y.,CAS Beijing National Laboratory for Molecular | Ye F.,CAS Beijing National Laboratory for Molecular | And 5 more authors.
Angewandte Chemie - International Edition | Year: 2014

A coupling reaction of N-phenoxyacetamides with N-tosylhydrazones or diazoesters through RhIII-catalyzed C-H activation is reported. In this reaction, ortho-alkenyl phenols were obtained in good yields and with excellent regio- and stereoselectivity. Rh-carbene migratory insertion is proposed as the key step in the reaction mechanism. © 2014 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Zhang L.,Nanyang Technological University | Loh P.C.,Nanyang Technological University | Gao F.,Shandong University
IEEE Transactions on Power Electronics | Year: 2012

A nine-switch power converter having two sets of output terminals was recently proposed in place of the traditional back-to-back power converter that uses 12 switches in total. The nine-switch converter has already been proven to have certain advantages, in addition to its component saving topological feature. Despite these advantages, the nine-switch converter has so far found limited applications due to its many perceived performance tradeoffs like requiring an oversized dc-link capacitor, limited amplitude sharing, and constrained phase shift between its two sets of output terminals. Instead of accepting these tradeoffs as limitations, a nine-switch power conditioner is proposed here that virtually converts most of these topological short comings into interesting performance advantages. Aiming further to reduce its switching losses, an appropriate discontinuous modulation scheme is proposed and studied here in detail to doubly ensure that maximal reduction of commutations is achieved. With an appropriately designed control scheme then incorporated, the nine-switch converter is shown to favorably raise the overall power quality in experiment, hence justifying its role as a power conditioner at a reduced semiconductor cost. © 2011 IEEE.

Tang Y.,Nanyang Technological University | Loh P.C.,Nanyang Technological University | Wang P.,Nanyang Technological University | Choo F.H.,Nanyang Technological University | Gao F.,Shandong University
IEEE Transactions on Power Electronics | Year: 2012

This paper investigates the inherent damping characteristic of LCL-filters for three-phase grid-connected voltage source inverters. Specifically, it is found that when the converter-side current is used for implementing the feedback control, there will be an inherent damping term embedded in the control loop, which can neutralize the resonance introduced by LCL-filters. Theoretical analysis is then presented to suggest a general design guideline for choosing values of grid-and converter-side inductors, so that optimum damping can be naturally achieved by solely using converter current control, doing away with active damping, passive damping, or complex state observer. In cases where the design criterion is not fulfilled, the damping information contained in the converter current is extracted by a second-order notch filter, and then processed by a compensation gain to tune the system damping factor. The proposed compensation strategy requires no additional hardware and it will not cause an overmodulation problem due to its free of fundamental component. Both simulation and experimental results are finally provided to validate the theoretical findings developed in this paper. © 2011 IEEE.

Xia G.,Hong Kong Polytechnic University | Wang S.,Shandong University | Zhao X.,Shandong University | Zhou L.,Hong Kong Polytechnic University
Journal of Materials Chemistry C | Year: 2013

A gold nanoparticle enhanced organic transistor non-volatile memory (ONVM) operated at ultralow voltages of up to -1 V has been achieved by facile room-temperature solution-processed hybrid nanolayer dielectrics. The amorphous ZrTiOx nanolayer dielectrics exhibit a high-k value of 18.9 and a high capacitance of 705 nF cm-2. With the modification of the octadecylphosphonic acid (ODPA) monolayer, the a-ZrTiOx/ODPA hybrid nanolayer dielectrics exhibit a high capacitance of 514 nF cm-2 and a very low leakage current density of 2 × 10-7 A cm -2. The pentacene transistor-based ONVMs with the a-ZrTiO x/ODPA hybrid nanolayer dielectrics could be operated in operating voltages as low as -1 V. With ultralow operating voltages, ONVMs show high performances, such as high hole mobility (0.3 cm2 V-1 s-1), large memory window (1.5 V), and long charge retention time (4 × 104 s) directly in ambient air. Our results suggest the great potential of low-temperature solution-processed hybrid nanolayer dielectrics for the realization of low-power and high-performance organic electronic devices. © The Royal Society of Chemistry 2013.

Hui E.C.M.,Hong Kong Polytechnic University | Xiao H.,Shandong University
ESAIM - Control, Optimisation and Calculus of Variations | Year: 2014

This paper addresses a new differential game problem with forward-backward doubly stochastic differential equations. There are two distinguishing features. One is that our game systems are initial coupled, rather than terminal coupled. The other is that the admissible control is required to be adapted to a subset of the information generated by the underlying Brownian motions. We establish a necessary condition and a sufficient condition for an equilibrium point of nonzero-sum games and a saddle point of zero-sum games. To illustrate some possible applications, an example of linear-quadratic nonzero-sum differential games is worked out. Applying stochastic filtering techniques, we obtain an explicit expression of the equilibrium point. © 2014 EDP Sciences, SMAI.

Cui S.,Hebei Normal University | Liu Y.,Hebei Normal University | Liu Y.,Shandong University | Ma X.,CAS Institute of High Energy Physics
Astroparticle Physics | Year: 2014

LHAASO (Large High Altitude Air Shower Observatory) is a large project to research on high energy gamma ray astronomy and cosmic ray physics. KM2A (one KM2 Array), one main part of the LHAASO project, using a 1 km 2 array composed of electron detectors (ED) and muon detectors (MD), focuses on gamma ray astronomy above 30 TeV and cosmic ray physics in the "knee" region. Accurate measurement of gamma ray energy spectra above 30 TeV is crucial to identify the sources as the galactic cosmic ray accelerators. Monte Carlo simulation indicates that cosmic gamma rays can be distinguished from cosmic nuclei background by using muon content in extensive air showers (EAS). With the sensitivity of about 1% of the integral flux of Crab Nebula, the high duty cycle of at least 90% and the full sky survey, the KM2A array would be very useful in discovering the galactic gamma ray sources and identifying the cosmic ray sources with gamma-ray emission. A detailed simulation is carried out for studying performance and expectation of the KM2A array in gamma ray astronomy above 30 TeV. © 2013 Elsevier B.V. All rights reserved.

Qi H.,Shandong University | Qi H.,Qingdao University | Li S.,Shandong University
Geriatrics and Gerontology International | Year: 2014

Aims: A dose-response meta-analysis was carried out between Parkinson's disease (PD) risk, and coffee, tea and caffeine consumption. Methods: A comprehensive search was carried out to identify eligible studies. The fixed or random effect model was used based on heterogeneity test. The dose-response relationship was assessed by restricted cubic spline. Results: A total of 13 articles involving 901764 participants for coffee, eight articles involving 344895 participants for tea and seven articles involving 492724 participants for caffeine were included. A non-linear relationship was found between coffee consumption and PD risk overall, and the strength of protection reached the maximum at approximately 3cups/day (smoking-adjusted relative risk: 0.72, 95% confidence interval 0.65-0.81). A linear relationship was found between tea and caffeine consumption, and PD risk overall, and the smoking-adjusted risk of PD decreased by 26% and 17% for every two cups/day and 200mg/day increments, respectively. The association of coffee and tea consumption with PD risk was stronger for men than that for women, and the association of caffeine consumption with PD risk was stronger for ever users of hormones than that for never users of hormones among postmenopausal women. The aforementioned associations were weaker for USA relative to Europe or Asia. Conclusions: A linear dose-relationship for decreased PD risk with tea and caffeine consumption was found, whereas the strength of protection reached a maximum at approximately 3cups/day for coffee consumption overall. Further studies are required to confirm the findings. © 2013 Japan Geriatrics Society.

Xu J.,Shandong University | Zhang H.,Shandong University | Xie L.,Nanyang Technological University
IEEE Transactions on Automatic Control | Year: 2012

In this note, we study the consensus problem for multiagent systems with measurement noises. Different from the existing approach, the consensus problem is converted to a root finding problem for which the stochastic approximation theory can be applied. By choosing an appropriate regression function, we propose a consensus algorithm which is applicable to systems with more general measurement noise processes, including stationary autoregressive and moving average (ARMA) processes and infinite moving average (MA) processes. Further, we establish a relationship between the convergence rate and the exponent of the step size of the algorithm. Particularly, strong convergence rate for systems with a leader-follower topology is studied. © 1963-2012 IEEE.

Sun S.,Shandong University | Li C.,Shandong University | Floreancig P.E.,University of Pittsburgh | Lou H.,Shandong University | Liu L.,Shandong University
Organic Letters | Year: 2015

The first catalytic asymmetric cross-dehydrogenative coupling of cyclic carbamates and terminal alkynes has been established. The reaction features high enantiocontrol and excellent functional group tolerance and displays a wide range of structurally and electronically diverse carbamates as well as terminal alkynes. N-Acyl hemiaminals were identified as the reactive intermediates through preliminary control experiments. Employing readily removable carbamates as substrates rather than traditionally adopted N-aryl amines allows applications in complex molecule synthesis and therefore advances the C-H functionalization strategy to a synthetically useful level. © 2015 American Chemical Society.

Yu H.,Shandong University | Liu J.,Qingdao University | Zhang H.,Shandong University | Kaminskii A.A.,Russian Academy of Sciences | And 2 more authors.
Laser and Photonics Reviews | Year: 2014

Sapphire, garnet and vanadate crystals are the most prominent optical materials, and vanadates play important roles in optics, especially in lasers and nonlinear optics. Neodymium-doped yttrium vanadate (Nd:YVO4) is representative and available commercially. Based on Nd:YVO4, several vanadate crystals are being developed with the goal of fulfilling the need for differential applications and improvement of certain operational aspects, such as with pulsed lasers or high-power continuous-wave lasers. In recent years, some important effects, including energy enhancement, bistability of output performance, self-Raman frequency shifting, etc., and some novel applications, such as quantum optics, pulsed lasers modulated by the two-dimensional crystals, etc., have been discovered with vanadates as gain materials. In this paper, the preparation, characterization and laser applications of vanadate laser crystals at the lasing wavelength of 1 micrometer, including YVO4, GdVO4, LuVO4, GdxY1-xVO4 and LuxGd1-xVO4 (0 < x < 1) doped with Nd3+ and ytterbium (Yb3+) are systematically reviewed by highlighting the most recent research progress. Their specific properties are presented, generation mechanisms of novel physical effects are discussed, new applications are given and possible future applications proposed by focusing on some potential strengths. © 2014 WILEY-VCH Verlag GmbH & Co.

Xing P.,Shandong University | Zhao Y.,Nanyang Technological University
Advanced Materials | Year: 2016

Supramolecular self-assembly shows significant potential to construct responsive materials. By tailoring the structural parameters of organic building blocks, nanosystems can be fabricated, whose performance in catalysis, energy storage and conversion, and biomedicine has been explored. Since small organic building blocks are structurally simple, easily modified, and reproducible, they are frequently employed in supramolecular self-assembly and materials science. The dynamic and adaptive nature of self-assembled nanoarchitectures affords an enhanced sensitivity to the changes in environmental conditions, favoring their applications in controllable drug release and bioimaging. Here, recent significant research advancements of small-organic-molecule self-assembled nanoarchitectures toward biomedical applications are highlighted. Functionalized assemblies, mainly including vesicles, nanoparticles, and micelles are categorized according to their topological morphologies and functions. These nanoarchitectures with different topologies possess distinguishing advantages in biological applications, well incarnating the structure-property relationship. By presenting some important discoveries, three domains of these nanoarchitectures in biomedical research are covered, including biosensors, bioimaging, and controlled release/therapy. The strategies regarding how to design and characterize organic assemblies to exhibit biomedical applications are also discussed. Up-to-date research developments in the field are provided and research challenges to be overcome in future studies are revealed. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Loh P.C.,Nanyang Technological University | Zhang L.,Nanyang Technological University | Gao F.,Shandong University
IEEE Transactions on Industrial Electronics | Year: 2013

Distributed generation systems usually include local energy sources, storages, and loads. Almost always, these entities have their own power converters for grid interfacing and energy processing. Having individual converters has advantages like more flexible individual control and simpler design but does not encourage functionality merging. Reduction of semiconductors to arrive at a more compact integrated design is thus not possible. Addressing this concern, a number of integrated energy generation systems that use 25% lesser semiconductors are proposed. The systems can be single or three phase depending on the types of sources, storages, and loads assembled. They can operate in the grid-tied or stand-alone mode with no compromise in performances expected, when compared with other solutions using more switches. For verifying the practicalities of the proposed integrated systems, experimental testing has already been performed on two example systems assembled in the laboratory. © 1982-2012 IEEE.

Li C.,Shandong University | Sun L.,Shandong University | Sun Y.,Shandong University | Teranishi T.,Kyoto University
Chemistry of Materials | Year: 2013

It generally requires a complex workup procedure for the fabrication of Au@Ag heterogeneous nanostructures with an accurate morphology by the present multistep seed-mediated growth approaches. In this paper, we present a new and straightforward method for the controllable synthesis of uniform Au@Ag heterogeneous nanorods (NRs) by coreduction of gold and silver sources in a one-pot polyol reaction. High-quality Au@Ag heterogeneous NRs of various aspect ratios were facilely and selectively produced in high concentration by tuning the initial experimental parameters. Our synthetic approach is highlighted by its simplicity, large-scale production, and controllability of the synthesis. Our study indicates the oxidative etching by O2/Cl- pairs plays a key role for the high-yield synthesis of uniform Au@Ag heterogeneous NRs. The size-dependent optical properties of Au@Ag heterogeneous NRs were first and systematically investigated. Our experiments reveal that Au@Ag heterogeneous NRs exhibit two strong absorption peaks that, respectively, originate from the transverse and longitudinal localized surface plasmon resonances (LSPRs). Moreover, the longitudinal LSPR can be facilely tuned from the visible to the near-infrared regions by changing the aspect ratio of Au@Ag heterogeneous NRs. Importantly, Au@Ag heterogeneous NRs synthesized by our method have an excellent stability. They can maintain their optical properties over a long period of time. Au@Ag heterogeneous NRs with an interesting plasmonic property would have fascinating application in surface plasmonics, surface-enhanced Raman scattering, chemical and biological sensing, optical labeling, and information storage. © 2013 American Chemical Society.

Zhang X.,Hong Kong Polytechnic University | Li H.,Yangzhou University | Ding F.,Shandong University
Advanced Materials | Year: 2014

As the most promising method for high quality, large area graphene synthesis, chemical vapor decomposition (CVD) has drawn enormous attention. Understanding of the growth mechanism is crucial for optimizing the experimental design to synthesize the desired graphene for various applications. Recently, many theoretical efforts have been devoted to explore the decomposition of feedstock, nucleation of small graphene islands, and the expansion of graphene islands to a large graphene sheet on various catalyst surfaces. Here we summarize the key progresses on the three aspects in order to provide a complete scenery of graphene CVD growth at the atomic level and to guide the experimental design for the synthesis of desired graphene, e.g., high quality graphene sheets with large single crystalline domains or controlled doping. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Zhang X.,Hong Kong Polytechnic University | Xu Z.,Hong Kong Polytechnic University | Hui L.,Shandong University | Xin J.,Hong Kong Polytechnic University | Ding F.,Hong Kong Polytechnic University
Journal of Physical Chemistry Letters | Year: 2012

We present a theoretical study on the determination of graphene orientation on the catalyst surface in chemical vapor deposition growth. Our study reveals that the interaction between the graphene wall and catalyst surface is weak and not sensitive to the orientation of graphene. The graphene edge-catalyst interaction is strong and sensitively depends on the graphene orientation. Therefore, the graphene edge-catalyst interaction is responsible for the orientation determination of a small graphene island in the early stage of graphene growth, and such an orientation can be inherited by the matured graphene due to the high barrier of graphene island rotation. On the basis of the mechanism of graphene orientation determination, various controversial-like experimental puzzles have been well-explained, and a potential of synthesizing large-area single-crystalline graphene on either single-crystalline or polycrystalline catalyst surfaces is revealed. © 2012 American Chemical Society.

Lou H.,Shandong University | Fan P.,Shandong University | Perez R.G.,University of Pittsburgh
Bioorganic and Medicinal Chemistry | Year: 2011

Linarin, a natural occurring flavanol glycoside derived from Mentha arvensis and Buddleja davidii is known to have anti-acetylcholinesterase effects. The present study intended to explore the neuroprotective effects of linarin against Aβ25-35-induced neurotoxicity with cultured rat pheochromocytoma cells (PC12 cells) and the possible mechanisms involved. For this purpose, PC12 cells were cultured and exposed to 30 μM Aβ25-35 in the absence or presence of linarin (0.1, 1.0 and 10 μM). In addition, the potential contribution of the PI3K/Akt neuroprotective pathway in linarin-mediated protection against Aβ25-35-induced neurotoxicity was also investigated. The results showed that linarin dose-dependently increased cell viability and reduced the number of apoptotic cells as measured by MTT assay, Annexin-V/PI staining, JC-1 staining and caspase-3 activity assay. Linarin could also inhibit acetylcholinesterase activity induced by Aβ25-35 in PC12 cells. Further study revealed that linarin induced the phosphorylation of Akt dose-dependently. Treatment of PC12 cells with the PI3K inhibitor LY294002 attenuated the protective effects of linarin. Furthermore, linarin also stimulated phosphorylation of glycogen synthase kinase-3β (GSK-3β), a downstream target of PI3K/Akt. Moreover, the expression of the anti-apoptotic protein Bcl-2 was also increased by linarin treatment. These results suggest that linarin prevents Aβ25-35-induced neurotoxicity through the activation of PI3K/Akt, which subsequently inhibits GSK-3β and up-regulates Bcl-2. These findings raise the possibility that linarin may be a potent therapeutic compound against Alzheimer's disease acting through both acetylcholinesterase inhibition and neuroprotection. © 2011 Elsevier Ltd. All rights reserved.

Qiu H.,Shandong University | Qiu H.,Nanyang Technological University | Zou F.,Shandong University
ACS Applied Materials and Interfaces | Year: 2012

By selectively dealloying a PtCoAl ternary alloy, a novel nanoporous PtCo (np-PtCo) alloy with a three-dimensional bicontinuous pore-ligament structure is successfully fabricated. X-ray diffraction and electron microscopic characterizations demonstrate the single-crystal nature of the alloy ligament with a ligament size down to ∼3 nm. After a mild electrochemical dealloying process, a nanoporous near-surface alloy structure with a Pt-rich surface and a PtCo alloy core is obtained. Electrochemical measurements show that the np-PtCo surface alloy has greatly enhanced catalytic activity and durability toward methanol electrooxidation compared with a state-of-the-art Pt/C catalyst. The peak current density of methanol electrooxidation on a np-PtCo surface alloy is more than 5 times of that on Pt/C. More importantly, continuous potential cycling from 0.6 to 0.9 V (vs RHE) in a 0.5 M H 2SO 4 aqueous solution demonstrates that a np-PtCo surface alloy has excellent structure stability, with more than 90% of the initial electrochemical active surface area (EASA) retained after 5000 potential cycles. Under the same conditions, the EASA of Pt/C drops to ∼70%. With evident advantages of facile preparation as well as enhanced electrocatalytic activity and durability, a np-PtCo surface alloy nanomaterial holds great potential as an anode catalyst in direct methanol fuel cells. © 2012 American Chemical Society.

Wang X.,Shandong University | Fu M.,University of Newcastle | Zhang H.,Shandong University
IEEE Transactions on Mobile Computing | Year: 2012

A common technical difficulty in target tracking in a wireless sensor network is that individual homogeneous sensors only measure their distances to the target whereas the state of the target composes of its position and velocity in the Cartesian coordinates. That is, the senor measurements are nonlinear in the target state. Extended Kalman filtering is a commonly used method to deal with the nonlinearity, but this often leads to unsatisfactory or even unstable tracking performances. In this paper, we present a new target tracking approach which avoids the instability problem and offers superior tracking performances. We first propose an improved noise model which incorporates both additive noises and multiplicative noises in distance sensing. We then use a maximum likelihood estimator for prelocalization to remove the sensing nonlinearity before applying a standard Kalman filter. The advantages of the proposed approach are demonstrated via experimental and simulation results. © 2012 IEEE.

Xu J.,Shandong University | Zhang H.,Shandong University | Xie L.,Nanyang Technological University
Automatica | Year: 2013

In this paper, we are concerned with the consensus of multi-agent systems with input delay. Among all standard static protocols that achieve the consensus for the multi-agent system under no input delay, we aim to find the maximum input delay such that the system remains consensusable under the same protocols. In the case of continuous-time systems, in view of the continuity of stability with respect to the time delay, the maximum delay margin for consensusability is given for scalar systems and vector systems with a single unstable open-loop pole. For scalar discrete-time systems, we show that the maximum delay margin for consensusability is strictly greater than zero if and only if the open-loop pole of the system is located in a specified interval. © 2013 Elsevier Ltd. All rights reserved.

Liu S.,Nanyang Technological University | Xie L.,Nanyang Technological University | Zhang H.,Shandong University
Automatica | Year: 2011

This paper studies the distributed consensus problem for linear discrete-time multi-agent systems with delays and noises in transmission channels. Due to the presence of noises and delays, existing techniques such as the lifting technique and the stochastic Lyapunov theory are no longer applicable to the analysis of consensus. In this paper, a novel technique is introduced to overcome the difficulties induced by the delays and noises. A consensus protocol with decaying gains satisfying persistence condition is adopted. Necessary and sufficient conditions for strong consensus and mean square consensus are respectively given for non-leaderfollower and leaderfollower cases under a fixed topology. Under dynamically switching topologies and randomly switching topologies, sufficient conditions for strong consensus and mean square consensus are also obtained. Numerical examples are given to demonstrate the effectiveness of the proposed protocols. © 2011 Elsevier Ltd. All rights reserved.

Qiu H.,Shandong University | Qiu H.,Nanyang Technological University | Huang X.,Shandong University
Journal of Materials Chemistry | Year: 2012

By selectively dealloying PtFeAl ternary alloy in 0.5 M NaOH solution, a novel nanoporous PtFe (np-PtFe) alloy with nanorod-like morphology and inherent three-dimensional bicontinuous ligament-pore structure was successfully fabricated. X-Ray diffraction and electron microscope characterization demonstrated the crystal nature of the alloy ligament with ligament size down to ∼3 nm. NaOH concentration plays a key role in the formation of a uniform PtFe alloy structure. Dealloying solution with a low NaOH concentration (0.5 M) is suitable for the formation of a pure PtFe alloy structure, while Fe 3O 4/np-PtFe nanocomposite is obtained when using a high NaOH concentration (≥2 M). The np-PtFe alloy can be facilely converted into a nanoporous near-surface alloy structure with a Pt-rich surface and PtFe alloy core by a second dealloying process in dilute HNO 3 solution. Electrochemical measurements show that the nanoporous near-surface alloy has greatly enhanced catalytic activity and durability towards methanol electro-oxidation compared with the state-of-the-art Pt/C catalyst. The peak current density of methanol electro-oxidation on the nanoporous surface alloy is about five times that on Pt/C. More importantly, continuous potential cycling from 0.6 to 0.9 V (vs. RHE) in 0.5 M H 2SO 4 aqueous solution demonstrates that the np-PtFe surface alloy has a better structural stability than commercial Pt/C. With evident advantages of facile preparation and enhanced electrocatalytic activity and durability, the np-PtFe surface alloy holds great potential as an anode catalyst in direct methanol fuel cells. © 2012 The Royal Society of Chemistry.

Sun Z.-Y.,Qufu Normal University | Liu Y.-G.,Shandong University
Asian Journal of Control | Year: 2015

This paper is concerned with adaptive stabilization for a class of uncertain high-order nonlinear systems with time delays. To the authors' knowledge, there has been no analogous result. Hence during investigation, the conditions on delay effect and the control design framework should be established for the first time. In this paper, under somewhat necessary restrictions on the system nonlinearities, by the method of adding a power integrator and the related adaptive technique, a procedure is developed to design the continuous adaptive state-feedback controller without overparametrization. Moreover, the uniform stability and convergence of the resulting closed-loop system are rigorously proven, with the aid of a suitable Lyapunov-Krasovskii functional. Finally, a numerical example is provided to illustrate the effectiveness of the theoretical result. © 2014 Chinese Automatic Control Society and Wiley Publishing Asia Pty Ltd.

Wang G.,Shandong University | Li Y.W.,University of Alberta
IEEE Transactions on Industrial Electronics | Year: 2010

A novel parabolic carrier pulsewidth modulation (PWM) method is proposed in this paper for direct current control in a voltage-source converter (VSC). This method employs a pair of parabolic PWM carriers (a positive one and a negative one) to determine the switching states of the two switches in a converter phase leg while limiting the current tracking error within a nonlinear hysteresis band. Similar to the hysteresis PWM method, the proposed parabolic PWM can regulate both dc current and ac current with excellent and accurate dynamic response. Furthermore, as a carrier-based PWM method, the proposed parabolic PWM can maintain a constant switching frequency by the automatic peak current error adjustment through the PWM process. In this paper, the basic operation principle of the proposed PWM method is discussed, and its implementation scheme is presented. Simulation and experimental results based on a single-phase VSC with bipolar PWM implementation are provided. © 2010 IEEE.

In this paper we investigate the existence of quasi-periodic solutions of non-autonomous two-dimensional reversible and Hamiltonian systems under the Bruno condition. As an application we study the dynamical stability of the trivial solution at the origin of a quasi-periodically forced planar system. Under a mild non-degeneracy condition we give a criterion that is necessary and sufficient for a large class of systems. © 2010 IOP Publishing Ltd and London Mathematical Society.

Wu Z.,Shandong University | Zhang F.,Shandong University of Finance and Economics
IEEE Transactions on Automatic Control | Year: 2011

We consider a stochastic optimal control problem of a forward-backward system in which the control variable consists of two components: the continuous control and the impulse control. The domain of the control is assumed to be convex. Necessary optimality conditions of the Pontryagin maximum principle type are obtained for this stochastic optimal control problem. We also give additional conditions, under which the necessary optimality conditions turn out to be sufficient. © 2006 IEEE.

Zhang Q.,Shandong University | Zhang Q.,University of Chinese Academy of Sciences | Zhang Z.,Shandong University
Physical Chemistry Chemical Physics | Year: 2010

The electrochemical dealloying of rapidly solidified Al-based alloys in a 1 M NaCl aqueous solution has been investigated using electrochemical measurements in combination with microstructural analysis. The results show that nanoporous metals (Au, Ag, Pd and Cu) with various morphologies can be fabricated through electrochemical dealloying of the Al-based alloys in the NaCl solution. The electrochemical behaviors of elemental metals (Al, Au, Ag, Pd and Cu) and precursor alloys for dealloying have been studied through open-circuit measurements, potentiodynamic anodic polarization and cyclic voltammetry. The dealloying mechanisms of the precursor alloys and the formation of the nanoporous metals have been analyzed based on cyclic voltammetry curves, chronoamperometry curves obtained at potentials above or below the critical potentials, and microstructural features of the as-dealloyed samples. In addition, a classification for dealloying of a bi-phasic alloy has been proposed according to different dealloying behaviors of coexistent phases in the alloy. It has been found that interactions between coexistent phases prevail during dealloying of the bi-phasic alloy and are in principle dependent on the diffusivity of the more noble element, the curvature-dependent undercritical potential dissolution, and the reaction between the more noble element and chloride ion. © the Owner Societies 2010.

Sun X.,University of British Columbia | Sun X.,Shandong University | Bromley-Brits K.,University of British Columbia | Song W.,University of British Columbia
Journal of Neurochemistry | Year: 2012

Alzheimer's disease (AD) is the most common neurodegenerative disorder leading to dementia. Neuritic plaques are the hallmark neuropathology in AD brains. Proteolytic processing of amyloid-β precursor protein at the β site by beta-site amyloid-β precursor protein-cleaving enzyme 1 (BACE1) is essential to generate Aβ, a central component of the neuritic plaques. BACE1 is increased in some sporadic AD brains, and dysregulation of BACE1 gene expression plays an important role in AD pathogenesis. This review will focus on the regulation of BACE1 gene expression at the transcriptional, post-transcriptional, translation initiation, translational and post-translational levels, and its role in AD pathogenesis. Further studies on BACE1 gene expression regulation will greatly contribute to our understanding of AD pathogenesis and reveal potential novel approaches for AD prevention and drug development. © 2011 International Society for Neurochemistry.

Zhang Y.,Shandong University | Zhang Y.,Yeshiva University | Bai Y.,Shandong University | Jia J.,Shandong University | And 5 more authors.
Chemical Society Reviews | Year: 2014

Nanotechnology is having a tremendous impact on our society. However, societal concerns about human safety under nanoparticle exposure may derail the broad application of this promising technology. Nanoparticles may enter the human body via various routes, including respiratory pathways, the digestive tract, skin contact, intravenous injection, and implantation. After absorption, nanoparticles are carried to distal organs by the bloodstream and the lymphatic system. During this process, they interact with biological molecules and perturb physiological systems. Although some ingested or absorbed nanoparticles are eliminated, others remain in the body for a long time. The human body is composed of multiple systems that work together to maintain physiological homeostasis. The unexpected invasion of these systems by nanoparticles disturbs normal cell signaling, impairs cell and organ functions, and may even cause pathological disorders. This review examines the comprehensive health risks of exposure to nanoparticles by discussing how nanoparticles perturb various physiological systems as revealed by animal studies. The potential toxicity of nanoparticles to each physiological system and the implications of disrupting the balance among systems are emphasized. © 2014 the Partner Organisations.

Fu S.,Shandong University | Zhang C.,Shandong University of Finance and Economics
Optics Letters | Year: 2012

Filtering off noise from a fringe pattern is one of the key tasks in optical interferometry. In this Letter, using some suitable function spaces to model different components of a fringe pattern, we propose a new fringe pattern denoising method based on image decomposition. In our method, a fringe image is divided into three parts: low-frequency fringe, high-frequency fringe, and noise, which are processed in different spaces. An adaptive threshold in wavelet shrinkage involved in this algorithm improves its denoising performance. Simulation and experimental results show that our algorithm obtains smooth and clean fringes with different frequencies while preserving fringe features effectively. © 2012 Optical Society of America.

Lu J.,Shandong University | Dai Y.,Shandong University | Jin H.,University of British Columbia | Huang B.,Shandong University
Physical Chemistry Chemical Physics | Year: 2011

Disorder-engineered nanophase anatase TiO 2 through hydrogenation has been demonstrated to exhibit substantial solar-driven photocatalytic activities [X. Chen, L. Liu, P. Y. Yu, S. S. Mao, Science, 2011, 331, 746], while the detailed image of the disorder is unclear, and the role of the hydrogenation as well as the mechanism of high photoactivity is still ambiguous. Based on first-principles calculations, we find by taking into account the synergic effect of Ti-H and O-H bonds that hydrogen atoms can be chemically absorbed both on Ti 5c and O 2c atoms for (101), (001), and (100) surfaces, while previous studies predicted that chemical absorption of H on both Ti 5c and O 2c only takes place on the (001) surface due to overlooking the synergic effect. The hydrogenation induces obvious lattice distortions on (101) and (100) surfaces of nanoparticles enhancing the intraband coupling within the valence band, while the (001) surface is not largely affected. Different from the previous understanding that the lattice disorder accounts for the induced mid-gap states while the hydrogen only stabilizes the lattice disorders by passivating their dangling bonds, we find that the adatoms not only induce the lattice disorders but also interact strongly with the Ti 3d and O 2p states, resulting in a considerable contribution to the mid-gap states. The optical absorption is dramatically red shifted due to the mid-gap states and the photogenerated electron-hole separation is substantially promoted as a result of electron-hole flow between different facets of hydrogenated nanoparticles, which may account for the exceptional high energy conversion efficiency under solar irradiation. Even more interestingly, we find that hydrogenation reverses the redox behavior of different surfaces of nanoparticles, which provides new hints that one can tune the photoexcited electron-hole flow between different surfaces of nanoparticles in accordance to one's request by appropriate chemical surface treatment. We believe that band-offset-engineering between different facets of nanocrystals can be an effective way to facilitate energy conversion efficiency and should be applicable to other nanophase materials. © the Owner Societies 2011.

Ni S.-Q.,Shandong University | Lee P.-H.,Iowa State University | Sung S.,Iowa State University
Bioresource Technology | Year: 2010

The anammox non-woven membrane reactor (ANMR) is a novel reactor configuration to culture the slowly growing anammox bacteria. Different mathematical models were used to study the process kinetics of the nitrogen removal in the ANMR. The kinetics of nitrogen gas production of anammox process was first evaluated in this paper. For substrate removal kinetics, the modified Stover-Kincannon model and the Grau second-order model were more applicable to the ANMR than the first-order model and the Monod model. For nitrogen gas production kinetics, the Van der Meer and Heertjes model was more appropriate than the modified Stover-Kincannon model. Model evaluation was carried out by comparing experimental data with predicted values calculated from suitable models. Both model kinetics study and model testing showed that the Grau second-order model and the Van der Meer and Heertjes model seemed to be the best models to describe the nitrogen removal and nitrogen gas production in the ANMR, respectively. © 2010 Elsevier Ltd. All rights reserved.

Ni S.-Q.,Shandong University | Sung S.,Iowa State University | Yue Q.-Y.,Shandong University | Gao B.-Y.,Shandong University
Ecological Engineering | Year: 2012

Process kinetics can present necessary information for granular anammox process but little study focused on the nitrogen removal kinetics of pilot-scale anammox granular process is available. In this study, the substrate removal kinetics in a pilot-scale anammox granular reactor were investigated by inoculating anammox granules in to an UASB reactor, which was then operated at different hydraulic retention times and nitrogen loading rates. The reactor showed good tolerance to substrate concentration shock while it was affected significantly by hydraulic shock. Molecular techniques confirmed the existence of at least four well-known anammox species and anammox cells accounted for 93.7% of total cells. Evaluation of the nitrogen removal kinetics indicated that the Grau second-order substrate removal model and the modified Stover-Kincannon model turned out to be appropriate to describe nitrogen removal of anammox granules, rather than the first-order substrate removal model, the Monod model, and the Contois model. Model evaluation was then carried out via assessing the linearity between the experimental data and predicted values, which proved the applicability of the two models. The information derived from the current study could guide and optimize the design of full-scale anammox granular reactors. © 2011 Elsevier B.V.

Wang P.,Shandong University | Huang B.,Shandong University | Dai Y.,Shandong University | Whangbo M.-H.,North Carolina State University
Physical Chemistry Chemical Physics | Year: 2012

The efforts to produce photocatalysts operating efficiently under visible light have led to a number of plasmonic photocatalysts, in which noble metal nanoparticles are deposited on the surface of polar semiconductor or insulator particles. In the metal-semiconductor composite photocatalysts, the noble metal nanoparticles act as a major component for harvesting visible light due to their surface plasmon resonance while the metal-semiconductor interface efficiently separates the photogenerated electrons and holes. In this article, we survey various plasmonic photocatalysts that have been prepared and characterized in recent years. © the Owner Societies 2012.

Li X.,Shandong University | Hao X.,Shandong University | Zhao M.,Shandong University | Wu Y.,Shandong University | And 3 more authors.
Advanced Materials | Year: 2013

Hexagonal boron nitride (h-BN) nanosheets are prepared by a novel and effective method, in which sodium hydroxide and potassium hydroxide molten salts are used to exfoliate h-BN to obtain nanosheets. BN nanoscrolls are also obtained. The as-prepared products can be readily dispersed in a wide range of solvents, including water and ethanol, and form stable dispersions. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Kong Y.,Shandong University | Zhang J.,York College
Psychiatry Research | Year: 2010

Suicide is a leading cause of death in individuals 15-34. years of age in China. Highly lethal pesticides are a common method used for suicide in Chinese rural areas. This case-control study aimed to test hypotheses concerning the suicide risks associated with pesticide access. Subjects included 370 rural completed suicides aged 15-34. years and 370 living controls matched on age, gender and residence (rural/urban location). Data were collected by a psychological autopsy design with proxy respondents. Pesticide access was a significant risk factor for suicide even after controlling for other known risk factors in social and psychiatric domains, such as education level, living situation, marital status, family annual income and mental disorder. Increased risk was accounted for by access to insecticide rather than other types of pesticides. Suicide intervention in China should focus on restricting access to pesticides, especially highly toxic insecticide, improving the resuscitation skills of rural primary-care health providers, promoting psychological and social support networks in rural areas and educating the general public about the suicide risk of having pesticides stored at the households. © 2009 Elsevier Ireland Ltd.

Zhao Y.-P.,New York University | Zhao Y.-P.,Shandong University | Tian Q.-Y.,New York University | Liu C.-J.,New York University
FEBS Letters | Year: 2013

PGRN and its derived engineered protein, Atsttrin, were reported to antagonize TNFα and protect against inflammatory arthritis [Tang, W. et al. (2011) The growth factor progranulin binds to TNF receptors and is therapeutic against inflammatory arthritis in mice. Science 332 (6028) 478-484]. Here we found that PGRN level was also significantly elevated in skin inflammation. PGRN-/- mice exhibited more severe inflammation following induction of oxazolone (OXA). In contrast, recombinant Atsttrin protein effectively attenuated inflammation in mice dermatitis model. In addition, the protective role of PGRN and Atsttrin in dermatitis was probably due to their inhibition on NF-κB signaling. Collectively, PGRN, especially its derived engineered protein, Atsttrin, may represent a potential molecular target for prevention and treatment of inflammatory skin diseases. © 2013 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.

Hong J.,Shandong University | Li X.,University of Michigan | Zhaojie C.,Shandong University
Waste Management | Year: 2010

A life cycle assessment was carried out to estimate the environmental impact of municipal solid waste. Four scenarios mostly used in China were compared to assess the influence of various technologies on environment: (1) landfill, (2) incineration, (3) composting plus landfill, and (4) composting plus incineration. In all scenarios, the technologies significantly contribute to global warming and increase the adverse impact of non-carcinogens on the environment. The technologies played only a small role in the impact of carcinogens, respiratory inorganics, terrestrial ecotoxicity, and non-renewable energy. Similarly, the influence of the technologies on the way other elements affect the environment was ignorable. Specifically, the direct emissions from the operation processes involved played an important role in most scenarios except for incineration, while potential impact generated from transport, infrastructure and energy consumption were quite small. In addition, in the global warming category, highest potential impact was observed in landfill because of the direct methane gas emissions. Electricity recovery from methane gas was the key factor for reducing the potential impact of global warming. Therefore, increasing the use of methane gas to recover electricity is highly recommended to reduce the adverse impact of landfills on the environment. © 2010 Elsevier Ltd.

Hong J.,Shandong University | Li X.,University of Michigan
Waste Management | Year: 2011

A life cycle assessment was carried out to estimate the environmental impact of sewage sludge as secondary raw material in cement production. To confirm and add credibility to the study, uncertainty analysis was conducted. Results showed the impact generated from respiratory inorganics, terrestrial ecotoxicity, global warming, and non-renewable energy categories had an important contribution to overall environmental impact, due to energy, clinker, and limestone production stages. Also, uncertainty analysis results showed the technology of sewage sludge as secondary raw material in cement production had little or no effect on changing the overall environmental potential impact generated from general cement production. Accordingly, using the technology of sewage sludge as secondary raw material in cement production is a good choice for reducing the pressure on the environment from dramatically increased sludge disposal. In addition, increasing electricity recovery rate, choosing natural gas fired electricity generation technology, and optimizing the raw material consumption in clinker production are highly recommended to reduce the adverse effects on the environment. © 2011 Elsevier Ltd.

Liu T.,Zhejiang University | Li D.,Zhejiang University | Yang D.,Zhejiang University | Jiang M.,Shandong University
Langmuir | Year: 2011

Using a simple chemical reaction, a new nanostructure of silver, which we call a "flower-like silver structure", is produced. The flower-like silver structure consists of a silver core and many rod-like tips protruding out in three dimensions. Besides common face-centeredcubic (FCC) phase of silver, there exists hexagonal-close-packed (HCP) phase in these tips. The appearance of HCP silver is the result of rapid growth of silver nuclei when using CH 2O or C2H4O as the reducing agent. The formation of the rod-like tips is caused by the anisotropic growth determined by the HCP phase and the directing role of formic acid, which is the oxidation product of CH2O. It is also found that the concentration of reactants, the kind of reducing agents and the sequence of adding reactants can influence the morphology and phase constitution of the final products. © 2011 American Chemical Society.

Wang G.,Shandong University | Huang B.,Shandong University | Ma X.,Shandong University | Wang Z.,Shandong University | And 4 more authors.
Angewandte Chemie - International Edition | Year: 2013

Crystal power! Libethenite, Cu2(OH)PO4 (see 4-5 μm×1.5 μm image), absorbs strongly in the near-infrared (NIR) region and is an effective photocatalyst for the decomposition of 2,4-dichlorophenol in aqueous solution under NIR irradiation. This NIR activation of the photocatalyst is due to a facile transfer of photogenerated electrons from the trigonal bipyramidal CuII sites to the adjacent octahedral Cu II sites. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Zhang Y.,Aix - Marseille University | Zhang Y.,Shandong University | Franco M.,University of Nice Sophia Antipolis | Ducret A.,Aix - Marseille University | Mignot T.,Aix - Marseille University
PLoS Biology | Year: 2010

Regulated cell polarity is central to many cellular processes. We investigated the mechanisms that govern the rapid switching of cell polarity (reversals) during motility of the bacterium Myxococcus xanthus. Cellular reversals are mediated by pole-to-pole oscillations of motility proteins and the frequency of the oscillations is under the control of the Frz chemosensory system. However, the molecular mechanism that creates dynamic polarity remained to be characterized. In this work, we establish that polarization is regulated by the GTP cycle of a Ras-like GTPase, MglA. We initially sought an MglA regulator and purified a protein, MglB, which was found to activate GTP hydrolysis by MglA. Using live fluorescence microscopy, we show that MglA and MglB localize at opposite poles and oscillate oppositely when cells reverse. In absence of MglB, MglA-YFP accumulates at the lagging cell end, leading to a strikingly aberrant reversal cycle. Spatial control of MglA is achieved through the GAP activity of MglB because an MglA mutant that cannot hydrolyze GTP accumulates at the lagging cell end, despite the presence of MglB. Genetic and cell biological studies show that the MglA-GTP cycle controls dynamic polarity and the reversal switch. The study supports a model wherein a chemosensory signal transduction system (Frz) activates reversals by relieving a spatial inhibition at the back pole of the cells: reversals are allowed by Frz-activated switching of MglB to the opposite pole, allowing MglA-GTP to accumulate at the back of the cells and create the polarity switch. In summary, our results provide insight into how bacteria regulate their polarity dynamically, revealing unsuspected conserved regulations with eukaryots. © 2010 Zhang et al.

Zheng Z.,Shandong University | Huang B.,Shandong University | Qin X.,Shandong University | Zhang X.,Shandong University | And 2 more authors.
Journal of Materials Chemistry | Year: 2011

We developed a facile in situ method of preparing noble-metal plasmonic photocatalysts M@TiO2 (M = Au, Pt, Ag). In this method, the UV irradiation of TiO2 powder dispersed in absolute ethanol generates some Ti3+ ions on the surface of TiO2 particles and these Ti3+ ions, upon addition of a noble-metal salt in the dark, reduce the metal cations to deposit metal nanoparticles on the TiO2 surface. This Ti3+-ion-assisted synthesis leads to a homogeneous loading of noble-metal nanoparticles on the surface of TiO2 particles, which allows photocatalytic reactions to take place under visible-light on the whole TiO2 surface. Among the three photocatalysts M@TiO2 (M = Au, Pt, Ag), Au@TiO2 exhibits a high yield (63%) and selectivity (91%) for the oxidation of benzene to phenol in aqueous phenol. For this photocatalytic reaction, our study suggests a mechanism in which the visible-light absorption by the Au nanoparticles causes electron transfer from the Au nanoparticles to the TiO2 particle, and the electron-depleted Au oxidizes phenoxy anions to form phenoxy radicals that oxidize benzene to phenol. © 2011 The Royal Society of Chemistry.