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Wu Y.,Chinese Academy of Sciences | Min G.,University of Bradford | Al-Dubai A.Y.,Napier University
IEEE Transactions on Wireless Communications | Year: 2012

The cognitive radio (CR) is an emerging technique for increasing the utilisation of communication resources by allowing the unlicensed users to employ the under-utilised spectrum. In this paper, a new analytical performance model is developed to evaluate the QoS of multi-hop CR networks. After validating its accuracy through extensive simulation experiments, the analytical model is adopted as a cost-effective tool to investigate the effects of the primary users' activities on the network performance. Moreover, the model can be used to study the strategy of employing under-utilised spectra so as to maximise the overall resource utilisation and network performance. © 2002-2012 IEEE.

Liu X.,CAS Lanzhou Institute of Chemical Physics | Liu X.,Chinese Academy of Sciences | Liang Y.,CAS Lanzhou Institute of Chemical Physics | Zhou F.,CAS Lanzhou Institute of Chemical Physics | Liu W.,CAS Lanzhou Institute of Chemical Physics
Soft Matter | Year: 2012

In this critical review, we summarize the recent developments of extreme wettability in nature and biomimetic examples, and then we focus on surface wetting behavior beyond nature, which means surface wetting properties that cannot be found in nature. They are: switchable wettability between (super)hydrophobicity and (super)hydrophilicity, switchable water/oil droplet adhesion between superhydrophobic pinning states and superhydrophobic rolling states, superoleophobicity at the air-solid interface or even under vacuum, and self-healing (super)amphiphobicity at the air-solid interface. © 2011 The Royal Society of Chemistry.

Bondarenko O.,Karlsruhe Institute of Technology | Liu X.,Chinese Academy of Sciences
Inverse Problems | Year: 2013

The inverse acoustic scattering by a penetrable obstacle with a general conductive boundary condition is considered. Having established the well posedness of the direct problem by a variational method, we study the factorization method for recovering the location and the shape of the obstacle. One by-product of the method is an explicit proof of uniqueness of the inverse scattering problem under certain assumptions. Some numerical experiments are also presented to demonstrate the feasibility and effectiveness of the factorization method. © 2013 IOP Publishing Ltd.

Guo H.,Chinese Academy of Sciences
International Journal of Digital Earth | Year: 2010

Since earthquakes, tropical storms, and floods are the three main global natural disasters causing the biggest loss, they should be the main focus of research in disaster science and disaster mitigation and prevention. This paper discusses the characteristics of these three global natural disasters from a scientific point of view, and analyses their patterns of distribution, origin and result, as well as the extent of their damage and measures of disaster mitigation and prevention. The paper, at the technical level, introduces the role of earth observation (EO) technologies in disaster mitigation, and real and quasi-real-time monitoring and assessment using advanced optical and microwaveEOcapacities,while digital earth technologies provide avery important role in rapidly acquiring spatial information of the disaster areas. The paper concludes by discussing the relationship between man and natural disasters, and proposes the viewpoint that man and nature should be able to harmoniously coexist, and the importance of understanding disasters from an earth system science perspective so as to better meet the challenges of natural disasters. © 2010 Taylor & Francis.

Zhang X.-G.,Chinese Academy of Sciences | Zhang X.-G.,Chinese Center for Antarctic Astronomy
Monthly Notices of the Royal Astronomical Society | Year: 2014

This is the first paper in a dedicated series to study the properties of the optically-selected broad-line-region-less (BLR-less) active galactic nuclei (AGNs; with no-hidden central broad emission line regions). We carried out a systematic search for the BLR-less AGNs through the Sloan Digital Sky Survey Legacy Survey (SDSS Stripe82 Database). Based on the spectral decomposition results for all the 136 676 spectroscopic objects (galaxies and quasars) with redshift less than 0.35 covered by the SDSS Stripe82 region, our spectroscopic sample for the BLR-less AGNs includes 22 693 pure narrow line objects without broad emission lines but with apparent AGN continuum emission RAGN > 0.3 and apparent stellar lights Rssp > 0.3. Then, using the properties of the photometry magnitude RMS (RMS) and Pearson's coefficients (R1, 2) between two different SDSS band light curves: RMSk 3 × RMSMk and R1, 2 > ∼0.8, the final 281 pure narrow line objects with true photometry variabilities are our selected reliable candidates for the BLR-less AGNs. The selected candidates with higher confidence levels not only have the expected spectral features of the BLR-less AGNs, but also show significant true photometry variabilities. The reported sample enlarges at least four times the current sample of the BLR-less AGNs, and will provide more reliable information to explain the lack of the BLRs of AGNs in our following studies. © 2013 The Author Published by Oxford University Press on behalf of the Royal Astronomical Society.

Li H.,Chinese Academy of Sciences
Zhongguo Zhong xi yi jie he za zhi Zhongguo Zhongxiyi jiehe zazhi = Chinese journal of integrated traditional and Western medicine / Zhongguo Zhong xi yi jie he xue hui, Zhongguo Zhong yi yan jiu yuan zhu ban | Year: 2013

To study the effects of Huannao Yicong Recipe (HNYCR)extract on the learning and memory ability, and the expressions of amyloid precursor protein (APP), beta-site APP-cleaving enzyme 1 (BACE1), presenilin-1 (PS-1), and beta amyloid protein (Abeta)in hippocampus CA1 area of APP transgenic mice, and to explore its mechanisms for treating Alzheimer's disease (AD). Totally 3-month-old APP695V7171 transgenic mice were used to establish the AD model in this research. They were randomly divided into the model group, the Donepezil group, the large dose HNYCR extract group, the small dose HNYCR extract group, and the normal control group (C57BL/6J mice), 15 in each group. These animals were gavaged for 4 continuous months. Relevant indicators were detected: Morris water maze test was used to measure the spatial learning and memory ability. The immunohistochemical assay was used to detect the expressions of APP, BACE1, PS-1, and Abeta. The times of crossing the original platform and the swimming time and distance in the fourth quadrant of the 7-month-old APP transgenic mice were significantly reduced in Morris water maze test, when compared with the normal control group (P < 0.01). The times of crossing original platform and the swimming time and distance in the fourth quadrant of all treatment groups significantly increased in Morris water maze test, when compared with the model group (P < 0.05). The expressions of APP, BACE1, PS-1, and Abeta in hippocampus CA1 area of 7-month-old model mice increased significantly (P < 0.01), when compared with the normal control group. The expressions of APP, BACE1, PS-1, and Abeta in each 7-month-old intervention groups were significantly reduced, when compared with the model group (P < 0.01). Early application of HNYCR extract can obviously improve the learning and memory ability of APP transgenic mice that has declined, reduce the expressions of APP, BACE1, PS-1, and Abeta in the hippocampal CA1 area, reduce the production of Abeta, and slow down the pathological process of brains in APP transgenic mice.

Zhang K.,University of Exeter | Kong D.,University of Exeter | Kong D.,Chinese Academy of Sciences | Schubert G.,University of California at Los Angeles
Astrophysical Journal | Year: 2015

The standard thermal wind equation (TWE) relating the vertical shear of a flow to the horizontal density gradient in an atmosphere has been used to calculate the external gravitational signature produced by zonal winds in the interiors of giant gaseous planets. We show, however, that in this application the TWE needs to be generalized to account for an associated gravitational perturbation. We refer to the generalized equation as the thermal-gravitational wind equation (TGWE). The generalized equation represents a two-dimensional kernel integral equation with the Green's function in its integrand and is hence much more difficult to solve than the standard TWE. We develop an extended spectral method for solving the TGWE in spherical geometry. We then apply the method to a generic gaseous Jupiter-like object with idealized zonal winds. We demonstrate that solutions of the TGWE are substantially different from those of the standard TWE. We conclude that the TGWE must be used to estimate the gravitational signature of zonal winds in giant gaseous planets. © 2015. The American Astronomical Society. All rights reserved.

Pang W.,Chinese Academy of Sciences
Dong wu xue yan jiu = Zoological research / "Dong wu xue yan jiu" bian ji wei yuan hui bian ji | Year: 2013

The pig-tailed macaque is an important non-human primate experimental animal model that has been widely used in the research of AIDS and other diseases. Pig-tailed macaques include Mentawai macaques (Macaca pagensis), Sunda pig-tailed macaques (M. nemestrina) and northern pig-tailed macaques (M. leonina). Northern pig-tailed macaques inhabit China and surrounding Southeast Asia countries. To our knowledge, no reports have been published regarding the hematology and blood chemistry parameters of northern pig-tailed macaques, which are important for the objective evaluation of experimental results. We measured and analyzed 18 hematology parameters and 13 blood chemistry parameters in juvenile (aged 2-4 years) and adult (aged 5-10 years) northern pig-tailed macaques. We found that red blood cells, hemoglobin and alkaline phosphatase values were lower in female macaques than male macaques in both juvenile and adult groups. White blood cells, lymphocyte, monocytes, platelet distribution width, cholesterol, aspartate aminotransferase and alkaline phosphatase values were higher in juvenile macaques than adult macaques, while creatinine and triglycerides values were lower in juvenile macaques. Mean corpuscular hemoglobin and creatinine values were positively correlated with weight in juvenile groups. In adult groups, mean corpuscular hemoglobin, percentage of granulocyte, hemoglobin and creatinine were also positively correlated with weight, and lymphocyte, percentage of lymphocyte, red cell distribution width, aspartate aminotransferase and cholesterol values were negatively correlated with weight. The results suggest that age, gender and weight of northern pig-tailed macaques affected their hematology and blood chemistry parameters. This hematological and blood chemistry study has great significance in biomedical research and animal models using northern pig-tailed macaque as an experimental animal.

Zhao J.,Chinese Academy of Sciences
Physics of Plasmas | Year: 2015

Analytical expressions for the dispersion relations and polarizations of low-frequency waves in magnetized plasmas based on two-fluid model are obtained. The properties of waves propagating at different angles (to the ambient magnetic field B0) and β (the ratio of the plasma to magnetic pressures) values are investigated. It is shown that two linearly polarized waves - namely, the fast and Alfvén modes in the low- β (β蠐1) plasmas, the fast and slow modes in the β∼1 plasmas, and the Alfvén and slow modes in the high- β (β蠑1) plasmas - become circularly polarized at the near-parallel (to B0) propagation. The negative magnetic-helicity of the Alfvén mode occurs only at small or moderate angles in the low-β plasmas, and the ion cross-helicity of the slow mode is nearly the same as that of the Alfvén mode in the high-β plasmas. It is also shown that the electric polarization δEz/δEy decreases with the temperature ratio Te/Ti for the long-wavelength waves, and the transition between left- and right-hand polarizations of the Alfvén mode in Te/Ti≠0 plasmas can disappear when Te/Ti=0. The approximate dispersion relations in the near-perpendicular propagation, low-β, and high-β limits can quite accurately describe the three modes. © 2015 AIP Publishing LLC.

Wang B.,CAS National Astronomical Observatories | Han Z.,Chinese Academy of Sciences
New Astronomy Reviews | Year: 2012

Type Ia supernovae (SNe Ia) play an important role in astrophysics and are crucial for the studies of stellar evolution, galaxy evolution and cosmology. They are generally thought to be thermonuclear explosions of accreting carbon-oxygen white dwarfs (CO WDs) in close binaries, however, the nature of the mass donor star is still unclear. In this article, we review various progenitor models proposed in the past years and summarize many observational results that can be used to put constraints on the nature of their progenitors. We also discuss the origin of SN Ia diversity and the impacts of SN Ia progenitors on some fields. The currently favourable progenitor model is the single-degenerate (SD) model, in which the WD accretes material from a non-degenerate companion star. This model may explain the similarities of most SNe Ia. It has long been argued that the double-degenerate (DD) model, which involves the merger of two CO WDs, may lead to an accretion-induced collapse rather than a thermonuclear explosion. However, recent observations of a few SNe Ia seem to support the DD model, and this model can produce normal SN Ia explosion under certain conditions. Additionally, the sub-luminous SNe Ia may be explained by the sub-Chandrasekhar mass model. At present, it seems likely that more than one progenitor model, including some variants of the SD and DD models, may be required to explain the observed diversity of SNe Ia. © 2012.

Luo G.-L.,North China Electrical Power University | Zhang X.,Chinese Academy of Sciences
Renewable and Sustainable Energy Reviews | Year: 2012

There are still more than 30% of the Tibetan administrative villages without power, and about 40% farmers there are suffering from a serious shortage of firewood. Tibet is abundant in the deposits of hydropower, geothermal, and solar energy. The practical ways to solve the universal service of Tibetan rural energy are researched in the paper. We find that there are two main objectives of the universal access to energy in Tibetan rural areas. One is to meet the demand of electricity consumption and daily energy consumption of the farmers and herdsmen without power, initially solve energy poverty, realize the equitable access to energy, and ensure the early access to modern civilization. The other is to guarantee the provision of energy required in Tibet's rural economic development and urbanization. Their accomplishment depends on the responsibilities' definition and implementation in the universal service of energy by the central and local governments, and on the establishment of a universal service mechanism of energy. The conflict between the need of energy development in the agricultural and pastoral areas of Tibet and its insufficient financial resources cannot be solved without the support and assistance from the central government and other developed provinces in China. © 2012 Elsevier Ltd. All rights reserved.

Li B.-J.,CAS Beijing National Laboratory for Molecular | Shi Z.-J.,CAS Beijing National Laboratory for Molecular | Shi Z.-J.,Chinese Academy of Sciences
Chemical Society Reviews | Year: 2012

In this tutorial review, we will summarize our recent efforts in transition metal-catalyzed oxidative coupling via C-H functionalization of aromatic, benzylic and allylic C-H bonds. Related works from other laboratories will be cited where suitable, aiming to give the readers a flavor of this field. Special emphasis is placed on the reaction design and development. © The Royal Society of Chemistry 2012.

Shao L.,Nanjing University of Information Science and Technology | Shao L.,University of Sheffield | Jones S.,University of Sheffield | Li X.,Chinese Academy of Sciences
IEEE Transactions on Circuits and Systems for Video Technology | Year: 2014

As digital video databases grow, so grows the problem of effectively navigating through them. In this paper we propose a novel content-based video retrieval approach to searching such video databases, specifically those involving human actions, incorporating spatio-temporal localization. We outline a novel, highly efficient localization model that first performs temporal localization based on histograms of evenly spaced time-slices, then spatial localization based on histograms of a 2-D spatial grid. We further argue that our retrieval model, based on the aforementioned localization, followed by relevance ranking, results in a highly discriminative system, while remaining an order of magnitude faster than the current state-of-the-art method. We also show how relevance feedback can be applied to our localization and ranking algorithms. As a result, the presented system is more directly applicable to real-world problems than any prior content-based video retrieval system. © 2014 IEEE.

BACKGROUND:: Intravenous chemotherapy administration is a high-risk process; attention must be paid to preventing errors that might occur during the administration of chemotherapy. OBJECTIVE:: The aim of this study is to investigate whether the healthcare failure mode and effect analysis (HFMEA) is a valid proactive method to apply to chemotherapy administration in the Chinese oncology inpatient setting. METHODS:: A multidisciplinary team created a flow diagram of the chemotherapy administration process and potential failure modes were identified and evaluated using a hazard-scoring matrix. Using a decision tree, failure mode recommendations were made. Chemotherapy error rates before and after the HFMEA were compared. RESULTS:: A total of 5 failure modes were identified with high hazard scores, and 15 recommendations were made. After the intervention, the chemotherapy error rate decreased significantly from 2.05% to 0.17%. CONCLUSIONS:: The complexity of intravenous chemotherapy makes it vulnerable to error, and with serious consequences. Multiple errors can occur during ordering, preparing, compounding, dispensing, and administering the chemotherapy. The process of HFMEA helped reduce the chemotherapy error rate in Chinese hospitalized patients. IMPLICATIONS FOR PRACTICE:: Clinicians in oncology can take effective measures to avoid chemotherapy errors using the HFMEA. Copyright © 2016 Wolters Kluwer Health, Inc. All rights reserved

Ma Y.L.,Chinese Academy of Sciences
Zhongguo Zhong xi yi jie he za zhi Zhongguo Zhongxiyi jiehe zazhi = Chinese journal of integrated traditional and Western medicine / Zhongguo Zhong xi yi jie he xue hui, Zhongguo Zhong yi yan jiu yuan zhu ban | Year: 2013

To observe the protection of Huanglian Jiedu Decoction (HJD) on high fat diet induced liver damage mice [hyperlipidemic mice lacking apolipoprotein E (ApoE(-/-))]. Wild type mice were divided into the wild common food group and the wild hyperlipidemia group. ApoE(-/-) mice were divided into the ApoE(-/-) common food group, the ApoE(-/-) hyperlipidemia group, and the ApoE(-/-) hyperlipidemia plus HJD group, 5 in each group. In the present study, wild type mice and homozygous apoE(-/-) mice were fed with a chow diet or a high cholesterol Western diet for 4 weeks. HJD at the daily dose of 5 g/kg was given to mice in the ApoE(-/-) hyperlipidemia plus HJD group by gastrogavage. The plasma levels of total cholesterol (TC), triglyceride (TG), low density cholesterol protein (LDL-C) were detected. The pathohistological changes of the liver were observed by Eosin and Hematoxylin (HE) staining. The liver macrophages and their subtype ratios, as well as macrophage surface receptor CD206 and CD36 were detected by flow cytometry. Typical pathological changes of simple fatty liver were manifested in the ApoE(-/-) hyperlipidemia group, TC, TG, and LDL-C increased, the macrophage ratio increased, the expression level of macrophage surface receptor CD206 decreased, showing statistical difference when compared with the ApoE(-/-) common food group (P < 0.01, P < 0.05). The ratio of alternatively activated macrophages (M2) subpopulations was lower in the ApoE(-/-) hyperlipidemia group than in the wild common food group (P < 0.05). There was no obvious change in the expression level of CD36. After intervened by HJD for 4 weeks, there was no obvious improvement in blood lipids. But the ratio of CD206+ M2 macrophages was significantly improved, when compared with the ApoE(-/-) hyperlipidemia group (P < 0.05). The pathological changes of fatty liver were significantly attenuated. The liver protection effect of HJD might be associated with immunoregulation of M2 macrophage subpopulations and injured tissue repairmen. Its immunoregulation and liver protection were independent from lipids lowering.

Yuan F.,Chinese Academy of Sciences | Narayan R.,Harvard - Smithsonian Center for Astrophysics
Annual Review of Astronomy and Astrophysics | Year: 2014

Black hole accretion flows can be divided into two broad classes: cold and hot. Whereas cold accretion flows consist of cool optically thick gas and are found at relatively high mass accretion rates, hot accretion flows, the topic of this review, are virially hot and optically thin, and occur at lower mass accretion rates. They are described by accretion solutions such as the advection-dominated accretion flow and luminous hot accretion flow. Because of energy advection, the radiative efficiency of these flows is in general lower than that of a standard thin accretion disk. Moreover, the efficiency decreases with decreasing mass accretion rate. Observations show that hot accretion flows are associated with jets. In addition, theoretical arguments suggest that hot flows should produce strong winds. Hot accretion flows are believed to be present in low-luminosity active galactic nuclei and in black hole X-ray binaries in the hard and quiescent states. The prototype is Sgr A, the ultralow-luminosity supermassive black hole at our Galactic center. The jet, wind, and radiation from a supermassive black hole with a hot accretion flow can interact with the external interstellar medium and modify the evolution of the host galaxy. Copyright © 2014 by Annual Reviews.

Zhang R.,Tongji University | Xie X.,Tongji University | Xie X.,Chinese Academy of Sciences
Acta Pharmacologica Sinica | Year: 2012

G-protein-coupled receptors (GPCRs) mediate many important physiological functions and are considered as one of the most successful therapeutic targets for a broad spectrum of diseases. The design and implementation of high-throughput GPCR assays that allow the cost-effective screening of large compound libraries to identify novel drug candidates are critical in early drug discovery. Early functional GPCR assays depend primarily on the measurement of G-protein-mediated 2nd messenger generation. Taking advantage of the continuously deepening understanding of GPCR signal transduction, many G-protein-independent pathways are utilized to detect the activity of GPCRs, and may provide additional information on functional selectivity of candidate compounds. With the combination of automated imaging systems and label-free detection systems, such assays are now suitable for high-throughput screening (HTS). In this review, we summarize the most widely used GPCR assays and recent advances in HTS technologies for GPCR drug discovery. © 2012 CPS and SIMM All rights reserved.

Li X.,Queens University | Yu Y.,Chinese Academy of Sciences | Funk C.D.,Queens University
FASEB Journal | Year: 2013

Cyclooxygenase-2 (COX-2)-derived prostaglandins are implicated in numerous inflammatory disorders. The purpose of these studies was to examine previously unexplored interactions between COX-2 induction and docosahexaenoic acid (DHA) via the free fatty acid receptor 4 (FFA4) signaling pathway in murine RAW 264.7 cells and peritoneal macrophages challenged with lipopolysaccharide (LPS). DHA dose (IC5018 M)- and time-dependently reduced COX-2 expression, without affecting COX-1. DHA (25 M for 24 h) decreased LPS-induced prostaglandin E2 (PGE2) synthesis by 81%, primarily through reducing COX-2 (60%), as well as down-regulating microsomal prostaglandin E synthase-1 (46%), but independently of peroxisome proliferator-activated receptors. FFA4 knockdown abrogated DHA effects on COX-2 induction, PGE2 production, and interleukin 6 (IL-6) gene expression. In the presence of inhibitors of eicosanoid metabolism via COX-2, 12/15-lipoxygenase and CYP450s (rofecoxib (1 M), PD146176 (2 M), or MS-PPOH (20 M)), DHA was still effective in attenuating COX-2 induction. Moreover, Toll-like receptor 4 signaling via Akt/JNK phosphorylation and p65 nuclear translocation was repressed by DHA-activated FFA4 coupling with arrestin 2, which was reversed by FFA4 knockdown. These data support DHA modulation of COX-2 expression and activity, in part, via FFA4, which provides a new mechanistic explanation for some of the anti-inflammatory effects of DHA.-Li, X., Yu, Y., Funk, C. D. Cyclooxygenase-2 induction in macrophages is modulated by docosahexaenoic acid via interactions with free fatty acid receptor 4 (FFA4). © FASEB.

Zhong Z.J.,Chinese Academy of Sciences
Zhonghua fu chan ke za zhi | Year: 2012

To assess the correlation of promoter methylation of DAPK1, RAR-β and MGMT with cervical lesions from cytology to histology, and to reveal the clinical value of DNA methylation in diagnosis of cervical intraepithelial neoplasia (CIN). A total of 103 random-selected cervical samples were collected from residual liquid-based cytology specimens after clinical use in cytopathological diagnosis in outpatient clinic of obstetrics and gynecology, Peking Union Medical Collage Hospital from March 2010 to October 2010. Informed consent was obtained from each woman before the initiation of the study. The methylation sensitive-high resolution melt (MS-HRM) assay was used to evaluate promoter methylation of three genes (DAPK1, RAR-β and MGMT) in 103 biopsy-confirmed liquid-based cervical cytology samples. Methylation levels and high-risk HPV DNA loading (HCII values) were analyzed in relation to both cytological and histological diagnosis. The methylation level of all three genes showed significant difference among the different cytological groups (P = 0.000, 0.011 and 0.002, respectively). The methylation level of DAPK1 and RAR-β showed significant difference among the different histological groups (P = 0.000 and 0.021), while there was no significant difference for MGMT. DAPK1 methylation levels was 1.47% in the CINII/high-grade precancerous lesions group, and 20.98% in the normal/CINI groups (P = 0.000), but there was no significant difference between CINII/high-grade precancerous lesions and normal/CINI groups for RAR-β and MGMT. The combination of DAPK1/HR-HPV loading showed a sensitivity of 0.825 and an area under the receiver operating characteristic curve (ROC) curve (AUC) of 0.695 as diagnostic methods for detecting CINII/high-grade precancerous lesions. DNA methylation such as DAPK1 and RAR-β, in combination with HR-HPV detection, may serve as biomarkers to detect CINII/high-grade precancerous lesions. Detection of methylated DNA from liquid-based cervical cytology specimens is technically feasible with the MS-HRM assay.

Jin S.,Chinese Academy of Sciences | van Dam T.,University of Luxembourg | Wdowinski S.,University of Miami
Journal of Geodynamics | Year: 2013

The interaction and coupling of the Earth system components that include the atmosphere, hydrosphere, cryosphere, lithosphere, and other fluids in Earth's interior, influence the Earth's shape, gravity field and its rotation (the three pillars of geodesy). The effects of global climate change, such as sea level rise, glacier melting, and geoharzards, also affect these observables. However, observations and models of Earth's system change have large uncertainties due to the lack of direct high temporal-spatial measurements. Nowadays, space geodetic techniques, particularly GNSS, VLBI, SLR, DORIS, InSAR, satellite gravimetry and altimetry provide a unique opportunity to monitor and, therefore, understand the processes and feedback mechanisms of the Earth system with high resolution and precision. In this paper, the status of current space geodetic techniques, some recent observations, and interpretations of those observations in terms of the Earth system are presented. These results include the role of space geodetic techniques, atmospheric-ionospheric sounding, ocean monitoring, hydrologic sensing, cryosphere mapping, crustal deformation and loading displacements, gravity field, geocenter motion, Earth's oblateness variations, Earth rotation and atmospheric-solid earth coupling, etc. The remaining questions and challenges regarding observing and understanding the Earth system are discussed. © 2013 Elsevier Ltd.

He J.H.,CAS Yunnan Astronomical Observatory | Takahashi S.,Academia Sinica, Taiwan | Chen X.,Chinese Academy of Sciences
Astrophysical Journal, Supplement Series | Year: 2012

A northern subsample of 89 Spitzer GLIMPSE extended green objects (EGOs), the candidate massive young stellar objects, are surveyed for molecular lines in two 1GHz ranges: 251.5-252.5 and 260.188-261.188GHz. A comprehensive catalog of observed molecular line data and spectral plots are presented. Eight molecular species are undoubtedly detected: H 13CO +, SiO, SO, CH 3OH, CH 3OCH 3, CH 3CH 2CN, HCOOCH 3, and HN 13C. The H 13CO +3-2 line is detected in 70 EGOs, among which 37 also show the SiO6-5 line, demonstrating their association with dense gas and supporting the outflow interpretation of the extended 4.5 μm excess emission. Our major dense gas and outflow tracers (H 13CO +, SiO, SO, and CH 3OH) are combined with our previous survey of 13CO, 12CO, and C 18O1-0 toward the same sample of EGOs for a multi-line, multi-cloud analysis of linewidth and luminosity correlations. Good log-linear correlations are found among all considered line luminosities, the explanation of which requires a universal similarity of density and thermal structures and probably of shock properties among all EGO clouds. It also requires that the shocks be produced within the natal clouds of the EGOs. Diverse degrees of correlation are found among the linewidths. However, both the linewidth and luminosity correlations tend to progressively worsen across larger cloud subcomponent size scales, depicting the increase of randomness across cloud subcomponent sizes. Moreover, the linewidth correlations among the three isotopic CO1-0 lines show data scatter as linear functions of the linewidth itself, indicating that the velocity randomness also increases with whole cloud sizes in a regular way. © © 2012. The American Astronomical Society. All rights reserved.

Shi Y.,University of Nebraska at Omaha | Shi Y.,Chinese Academy of Sciences
Knowledge and Information Systems | Year: 2010

Support Vector Machine, an optimization technique, is well known in the data mining community. In fact, many other optimization techniques have been effectively used in dealing with data separation and analysis. For the last 10 years, the author and his colleagues have proposed and extended a series of optimization-based classification models via Multiple Criteria Linear Programming (MCLP) and Multiple Criteria Quadratic Programming (MCQP). These methods are different from statistics, decision tree induction, and neural networks. The purpose of this paper is to review the basic concepts and frameworks of these methods and promote the research interests in the data mining community. According to the evolution of multiple criteria programming, the paper starts with the bases of MCLP. Then, it further discusses penalized MCLP, MCQP, Multiple Criteria Fuzzy Linear Programming (MCFLP), Multi-Class Multiple Criteria Programming (MCMCP), and the kernel-based Multiple Criteria Linear Program, as well as MCLP-based regression. This paper also outlines several applications of Multiple Criteria optimization-based data mining methods, such as Credit Card Risk Analysis, Classification of HIV-1 Mediated Neuronal Dendritic and Synaptic Damage, Network Intrusion Detection, Firm Bankruptcy Prediction, and VIP E-Mail Behavior Analysis. © 2009 Springer-Verlag London Limited.

Zhang N.,Fudan University | Zeng L.,Fudan University | Shan H.,Chinese Academy of Sciences | Ma H.,Fudan University
New Phytologist | Year: 2012

Organismal phylogeny provides a crucial evolutionary framework for many studies and the angiosperm phylogeny has been greatly improved recently, largely using organellar and rDNA genes. However, low-copy protein-coding nuclear genes have not been widely used on a large scale in spite of the advantages of their biparental inheritance and vast number of choices. Here, we identified 1083 highly conserved low-copy nuclear genes by genome comparison. Furthermore, we demonstrated the use of five nuclear genes in 91 angiosperms representing 46 orders (73% of orders) and three gymnosperms as outgroups for a highly resolved phylogeny. These nuclear genes are easy to clone and align, and more phylogenetically informative than widely used organellar genes. The angiosperm phylogeny reconstructed using these genes was largely congruent with previous ones mainly inferred from organellar genes. Intriguingly, several new placements were uncovered for some groups, including those among the rosids, the asterids, and between the eudicots and several basal angiosperm groups. These conserved universal nuclear genes have several inherent qualities enabling them to be good markers for reconstructing angiosperm phylogeny, even eukaryotic relationships, further providing new insights into the evolutionary history of angiosperms. © 2012 The Authors. New Phytologist © 2012 New Phytologist Trust.

Li N.,Chinese Academy of Sciences
Zhonghua yu fang yi xue za zhi [Chinese journal of preventive medicine] | Year: 2012

Based on the registered female breast cancer data from 1998 to 2007, to analyze the incidence of female breast cancer during the period and then to predict its trend from 2008 to 2015. The incidence data of breast cancer from 1998 to 2007 were sorted from National Cancer Registry Database, including 74 936 cases from urban areas and 8230 cases from rural areas, separately covering 164 830 893 and 55 395 229 person years. The crude incidence rates in urban and rural areas were calculated, and the age-standardized rate (ASR) was adjusted by World Segi's population composition. JoinPoint software was applied to analyze the 10 years' incidence trend and calculated the annual percentage of changing (APC), while Age-Period-Cohort Bayesian Model was used to fit the data and predict the incidence of breast cancer between 2008 and 2015. From 1998 to 2007, the incidence of breast cancer in the urban cancer registration areas was 45.46/100 000 (74 936/164 830 893), whose ASR was 31.28/100 000. While in rural registration areas, the incidence and ASR was 14.86/100 000 (8230/55 395 229) and 12.13/100 000. The breast cancer incidence in urban and rural areas separately rose from 36.17/100 000 (3920/10 838 355) and 10.39/100 000 (436/4 197 806) in 1998 to 51.24/100 000 (11 302/22 057 787) and 19.61/100 000 (1475/7 522 690) in 2007. During the 10 years, the breast cancer incidence increased both in urban and rural areas, but the increase rate in rural incidence (6.3%) was more significant than it in urban areas (3.9%). Age-Period-Cohort Bayesian Model predicted that the breast cancer incidence would increase to 53.87/100 000 (185 585 new cases) in urban areas and 40.14/100 000 (132 432 new cases) in rural areas, respectively. The breast cancer incidence has been increasing annually both in urban and rural areas in China; and an annually increase number of new cases have been predicted.

Wang A.-P.,Chinese Academy of Sciences
Acta Mechanica Sinica/Lixue Xuebao | Year: 2012

A new kind of quadrilateral assumed stress hybrid membrane element with drilling degrees of freedom and a traction-free inclined side has been developed based on an extended Hellinger-Reissner principle which is established by expanding the essential terms of the assumed stress field as polynomials in the natural coordinates of the element. The homogeneous equilibrium equations are imposed in a variational sense through the internal displacements which are also expanded in the natural coordinates, while the tractionfree conditions along the inclined side are satisfied exactly. The use of such special element in the finite element solution is shown to be highly accurate when only a very coarse element mesh is used for plates with V-shaped rounded notches or inclined sides. © The Chinese Society of Theoretical and Applied Mechanics and Springer-Verlag Berlin Heidelberg 2012.

Samokhvalov I.M.,Chinese Academy of Sciences | Samokhvalov I.M.,Guangdong Provincial Key Laboratory of Stem Cell and Regenerative Medicine
Cellular and Molecular Life Sciences | Year: 2014

Two different models describe the development of definitive hematopoiesis and hematopoietic stem cells (HSCs). In one of these, the visceral yolk sac serves as a starting point of relatively lengthy developmental process culminating in the fetal liver hematopoiesis. In another, the origin of adult hematopoiesis is split between the yolk sac and the dorsal aorta, which has a peculiar capacity to generate definitive HSCs. Despite a large amount of experimental data consistent with the latter view, it becomes increasingly unsustainable in the light of recent cell tracing studies. Moreover, analysis of the published studies supporting the aorta-centered version uncovers significant caveats in standard experimental approach and argumentation. As a result, the theory cannot offer feasible cellular mechanisms of the HSC emergence. This review summarizes key efforts to discern the developmental pathway of the adult-type HSCs and attempts to put forward a hypothesis on the inflammatory mechanisms of hematopoietic ontogenesis. © 2013 Springer Basel.

Zhao Y.,CAS Fujian Institute of Research on the Structure of Matter | Zhao Y.,Nanyang Technological University | Wu W.,CAS Fujian Institute of Research on the Structure of Matter | Li J.,CAS Fujian Institute of Research on the Structure of Matter | And 3 more authors.
Advanced Materials | Year: 2014

A tube-in-tube carbon nanostructure (TTCN) with multi-walled carbon nanotubes (MWNTs) confined within hollow porous carbon nanotubes is synthesized for Li-S batteries. The structure is designed to enhance the electrical conductivity, hamper the dissolution of lithium polysulfide, and provide large pore volume for sulfur impregnation. As a cathode material for Li-S batteries, the S-TTCN composite with 71 wt% sulfur content delivers high reversible capacity, good cycling performance as well as excellent rate capabilities. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

He Z.,Peking Union Medical College | Liu J.,Peking Union Medical College | Du L.,Chinese Academy of Sciences
Nanoscale | Year: 2014

Polyethylene glycol-functionalized gold nanoparticles (PEGylated AuNPs) have been widely used as nanocarriers for the delivery of various drugs. However, little attention has been paid to whether the PEGylated AuNPs could affect the primary function of human erythrocytes, which is the main cellular component in the blood. In the current study, we show that both the deformability and oxygen-delivering ability of erythrocytes are decreased when treated with PEGyalted AuNPs of various sizes, which can be attributed to the interaction between PEGylated AuNPs and erythrocyte membranes. It is observed that the PEGylated AuNPs could also induce the aggregation of band-3 and the ATP decrease of erythrocytes. In addition, the PEGylated AuNPs can accelerate the loss of CD47 on erythrocyte membranes, possibly enhancing the senescent process of erythrocytes and the following clearance by SIRPα-expressing leukocytes in bloodstream. The results suggested that PEGylated AuNPs have the potential to affect the primary function of human erythrocytes, which should be considered when using them as drug carriers. This journal is © the Partner Organisations 2014.

Li S.,Stevens Institute of Technology | Li Y.,Chinese Academy of Sciences | Wang Z.,University of Toronto
Neural Networks | Year: 2013

This paper presents a class of recurrent neural networks to solve quadratic programming problems. Different from most existing recurrent neural networks for solving quadratic programming problems, the proposed neural network model converges in finite time and the activation function is not required to be a hard-limiting function for finite convergence time. The stability, finite-time convergence property and the optimality of the proposed neural network for solving the original quadratic programming problem are proven in theory. Extensive simulations are performed to evaluate the performance of the neural network with different parameters. In addition, the proposed neural network is applied to solving the k-winner-take-all (k-WTA) problem. Both theoretical analysis and numerical simulations validate the effectiveness of our method for solving the k-WTA problem. © 2012 Elsevier Ltd.

Gu G.-F.,East China University of Science and Technology | Zhou W.-X.,East China University of Science and Technology | Zhou W.-X.,Chinese Academy of Sciences
Physical Review E - Statistical, Nonlinear, and Soft Matter Physics | Year: 2010

The detrending moving average (DMA) algorithm is a widely used technique to quantify the long-term correlations of nonstationary time series and the long-range correlations of fractal surfaces, which contains a parameter θ determining the position of the detrending window. We develop multifractal detrending moving average (MFDMA) algorithms for the analysis of one-dimensional multifractal measures and higher-dimensional multifractals, which is a generalization of the DMA method. The performance of the one-dimensional and two-dimensional MFDMA methods is investigated using synthetic multifractal measures with analytical solutions for backward (θ=0), centered (θ=0.5), and forward (θ=1) detrending windows. We find that the estimated multifractal scaling exponent τ (q) and the singularity spectrum f (α) are in good agreement with the theoretical values. In addition, the backward MFDMA method has the best performance, which provides the most accurate estimates of the scaling exponents with lowest error bars, while the centered MFDMA method has the worse performance. It is found that the backward MFDMA algorithm also outperforms the multifractal detrended fluctuation analysis. The one-dimensional backward MFDMA method is applied to analyzing the time series of Shanghai Stock Exchange Composite Index and its multifractal nature is confirmed. © 2010 The American Physical Society.

Li Y.,University of New Mexico | Suleimanov Y.V.,Massachusetts Institute of Technology | Yang M.,Chinese Academy of Sciences | Green W.H.,Massachusetts Institute of Technology | Guo H.,University of New Mexico
Journal of Physical Chemistry Letters | Year: 2013

The thermal rate constant of the O(3P) + CH4 → OH + CH3 reaction is investigated with ring polymer molecular dynamics on a full-dimensional potential energy surface. Good agreement with experimental and full-dimensional quantum multiconfiguration time-dependent Hartree results between 300 and 1500 K was obtained. It is shown that quantum effects, for example, tunneling and zero-point energy, can be effectively and efficiently included in this path-integral based approach implemented with classical trajectories. Convergence with respect to the number of beads is rapid, suggesting wide applicability for other reactions involving polyatomic molecules. © 2012 American Chemical Society.

Li N.,International Agency for Research on Cancer | Li N.,Chinese Academy of Sciences | Franceschi S.,International Agency for Research on Cancer | Howell-Jones R.,International Agency for Research on Cancer | And 2 more authors.
International Journal of Cancer | Year: 2011

Pooled data on human papillomavirus (HPV) type distribution in invasive cervical cancer (ICC) can help to predict the potential impact of HPV type-specific vaccines and screening tests, and to understand the carcinogenicity of HPV types. We performed a meta-analysis of HPV type-specific prevalence data published from 1990 to 2010, including a total of 243 studies and 30,848 ICC. The proportion of ICC associated with HPV16 and/or 18 (HPV16/18) was between 70 and 76% in all world regions except Asia. In Western/Central Asia, 82% of ICC was HPV16/18-associated compared to only 68% in Eastern Asia. The 12 most common HPV types identified, in order of decreasing prevalence, were HPV16 (57%), 18 (16%), 58, 33, 45, 31, 52, 35, 59, 39, 51 and 56. The prevalence of other types, phylogenetically related to those above, ranged from <0.1% for HPV85 to 0.6% for HPV68. Overall HPV prevalence increased significantly from 85.9% in studies published from 1990 to 1999 to 92.9% in studies published from 2006 to 2010. Prevalence increases were large for multiple infections (from 4.0 to 15.7%) and for HPV16 (from 51.8 to 60.0%, including HPV16 alone or in multiple infections). Smaller but significant increases in prevalence were also seen for HPV39, 53 and 58. A large amount of recently published data has improved the understanding of the contribution of a broad range of HPV types to ICC in different world regions. However, estimating the fraction of ICC attributable to different types is increasingly complicated by the detection of multiple HPV infections in ICC. Copyright © 2010 UICC.

Gao Y.,Chinese Academy of Sciences
Lixue Xuebao/Chinese Journal of Theoretical and Applied Mechanics | Year: 2011

In 1963, Dr. Qian Xuesen (Tsien Hsue-Shen) pointed out the significance of the study on in-terplanetary travel, and revealed the potential utilization of electric propulsion in his book "Introduction to Interplanetary Travel" (in Chinese). Compared to traditional chemical propulsion, the high-specific-impulse electric propulsion is promising to carry more payloads and achieve enhanced flight performance for interplanetary travel. Meanwhile, the design and optimization of continuous-thrust transfer trajectories resulting from the use of electric propulsion have brought new research contents to the traditional spacecraft's orbital dynamics, and meanwhile guides the future development of electric propulsion. This article will present technological progress of electric propulsion, continuous-thrust trajectory design, and comprehensive optimization of interplanetary flight, attempting to describe the fundamental content and approach of the utilization of electric propulsion for interplanetary travel, as well as for manned deep-space flight.

Su J.T.,CAS National Astronomical Observatories | Su J.T.,Chinese Academy of Sciences
Astrophysical Journal | Year: 2014

Observations from the Atmospheric Imaging Assembly (AIA) on board the Solar Dynamics Observatory are utilized to statistically investigate the propagating quasi-periodic oscillations in the solar polar plume and inter-plume regions. On average, the periods are found to be nearly equal in the three coronal channels of AIA 171 Å, 193 Å, and 211 Å, and the wavelengths increase with temperature from 171 Å, 193 Å, and 211 Å. The phase speeds may be inferred from the above parameters. Furthermore, the speed ratios of v 193/v 171and v 211/v 171are derived, e.g., 1.4 ± 0.8 and 2.0 ± 1.9 in the plume regions, respectively, which are equivalent to the theoretical ones for acoustic waves. We find that there are no significant differences for the detected parameters between the plume and inter-plume regions. To our knowledge, this is the first time that we have simultaneously obtained the phase speeds of slow-mode waves in the three channels in the open coronal magnetic structures due to the method adopted in the present work, which is able to minimize the influence of the jets or eruptions on wave signals. © 2014. The American Astronomical Society. All rights reserved..

Li X.,Pennsylvania State University | Ming P.,Chinese Academy of Sciences
Communications in Computational Physics | Year: 2014

Numerical error caused by "ghost forces" in a quasicontinuum method is studied in the context of dynamic problems. The error in the discrete W1,∞ norm is analyzed for the time scale O(å) and the time scale O(7sigma;) with å being the lattice spacing.

Chen N.,CAS Shanghai Institute of Applied Physics | Li J.,CAS Shanghai Institute of Applied Physics | Song H.,Chinese Academy of Sciences | Chao J.,CAS Shanghai Institute of Applied Physics | And 2 more authors.
Accounts of Chemical Research | Year: 2014

ConspectusHighly specific DNA base-pairing is the basis for both fulfilling its genetic role and constructing novel nanostructures and hybrid conjugates with inorganic nanomaterials (NMs). There exist many remarkable differences in the physical properties of single-stranded (ss) and double-stranded (ds) DNA, which play important roles in regulation of biological processes in nature. Rapid advances in nanoscience and nanotechnology pose new questions on how DNA and DNA structures interact with inorganic nanomaterials or cells and animals, which should be important for their biological and biomedical applications. In this Account, we intend to provide an overview on many facets of DNA and DNA structures in artificial and living systems, with the focus on their properties and functions at the interfaces of inorganic nanomaterials and biological systems.ssDNA, dsDNA, and DNA nanostructures interact with NMs in different ways. In particular, gold nanoparticles and graphene oxide exhibit strikingly different affinity toward ssDNA and dsDNA. Such binding differences can be coupled with optical properties of NMs. For example, DNA hybridization can effectively modulate the plasmonic and catalytic properties of gold nanoparticles. By exploitation of these interactions, there have been many ways for sensitive transduction of biomolecular recognition for various sensing applications. Alternatively, modulation of the properties of DNA and DNA structures with NMs has led to new tools for genetic analysis including genotyping and haplotyping.Self-assembled DNA nanostructures have emerged as a new type of NMs with pure biomolecules. These nanostructures can be designed in one, two, or three dimensions with various sizes, shapes, and geometries. They also have characteristics of uniform size, precise addressability, excellent water solubility, and biocompatibility. These nanostructures provide a new toolbox for biophysical studies with unparalleled advantages, for example, NMR-based protein structure determination and single-molecule studies. Also importantly, DNA nanostructures have proven highly useful in various applications including biological detection, bioreactors, and nanomedicine. In particular, DNA nanostructures exhibit high cellular permeability, a property that is not available for ssDNA and dsDNA, which is required for their drug delivery applications.DNA and DNA structures can also form hybrids with inorganic NMs. Notably, DNA anchored at the interface of inorganic NMs behaves differently from that at the macroscopic interface. Several types of DNA-NM conjugates have exerted beneficial effects for bioassays and in vitro translation of proteins. Even more interestingly, hybrid nanoconjugates demonstrate distinct properties under the context of biological systems such as cultured cells or animal models. These unprecedented properties not only arouse great interest in studying such interfaces but also open new opportunities for numerous applications in artificial and living systems. © 2014 American Chemical Society.

Wang C.,Brown University | Wei Y.,Chinese Academy of Sciences | Jiang H.,Brown University | Sun S.,Brown University
Nano Letters | Year: 2010

The effect of mechanical disturbance on one-dimensional nanocrystal growth in solution phase is investigated by controlled growth of Au nanowires with and without stirring. While a static growth leads to straight, single-crystal Au nanowires, the mechanic disturbance by stirring tends to bend the nanowire growth, yielding nanowire kinks abundant in various types of crystal defects including dislocations, twin boundaries, and grain boundaries. Mechanical modeling and analysis is introduced to elucidate the nanowire growth mechanisms in these two conditions. The provided fundamental understanding of crystal defect formation at nanoscale could be applied to guide the development of advanced nanomaterials with shape control and unique mechanical properties. © 2010 American Chemical Society.

Zhang C.,Central University of Finance and Economics | Bai J.,Chinese Academy of Sciences | Wahl T.I.,North Dakota State University
Food Control | Year: 2012

We analyzed consumers' willingness to pay (WTP) for traceable pork, milk and cooking oil, and its determinants using data from Nanjing, China, with particular focus on the effects of consumer knowledge. The major findings suggest that Nanjing consumers are willing to pay a significant positive price premium for food traceability despite variations across products. Meanwhile, consumers' WTP for food traceability was positively affected by consumer knowledge about food traceability and awareness of food quality- and safety-related certifications. A number of demographics such as income and age also have statistically significant impacts on the WTP. © 2012 Elsevier Ltd.

Dai Z.,Chinese Academy of Sciences
Zhonghua yu fang yi xue za zhi [Chinese journal of preventive medicine] | Year: 2012

Based on the data from National Cancer Registry between 1998 and 2007, to analyze the colorectal cancer incidence trend in China, and further to predict its incidence between 2008 and 2015. We picked up the incidence data of 111 281 cases of colorectal cancer in total from National Central Cancer Registry Database between 1998 and 2007, covering 446 734 668 person-year. The annual incidence rate of colorectal cancer both by area and gender were calculated; while the age standardized rate (ASR) was standardized by world's population age structure. The incidence trend was analyzed and the annual percentage change (APC) was calculated by JoinPoint software. Age-Period-Cohort Bayesian Model was applied to fit the colorectal cancer incidence trend in China between 1998 and 2007; and further to predict its incidence between 2008 and 2015. From 1998 to 2007, the colorectal cancer registered incidence was 24.91/100 000 (111 281/446 734 668), with the ASR at 17.67/100 000. The incidence in male population was 26.50/100 000 (60 015/226 508 545), with ASR at 19.90/100 000; and the incidence in female was 23.28/100 000 (51 266/220 226 123), with ASR at 15.73/100 000. In urban area, the male incidence rose from 23.29/100 000 (2617/11 237 967) in 1998 to 37.84/100 000 (8534/22 551 353) in 2007; while the female incidence increased from 21.75/100 000 (2357/10 838 355) to 31.34/100 000 (6913/22 057 787). And in rural areas, the male and female incidences rose from 10.36/100 000 (448/4 323 628) and 8.86/100 000 (372/4 197 806) in 1998 to 16.80/100 000 (1290/7 677 484) and 13.00/100 000 (978/7 522 690) in 2007 respectively. In this decade, the colorectal cancer incidence has increased both in urban and rural areas. In urban area, the male APC value was 5.5% and the female APC value was 4.0%; while in rural area, the male and female APC values were 6.0% and 4.3% respectively. After adjusted by age structure, the uptrend became gently; with the urban male and urban female APC values separately increased by 3.7%, 2.5% and 2.3%. The rural male APC value rocketed up by 8.4% after its inflection point in 2004. The Bayesian model predicted that the male and female colorectal cancer incidences would separately reach 33.92/100 000 (125 thousand cases) and 27.13/100 000 (93 thousand cases) in urban areas; and 13.61/100 000 (48 thousand cases) and 13.68/100 000 (45 thousand cases) in rural areas by year 2015. The colorectal cancer incidence in China has been increasing annually; and it will continue to rise in the next years.

Zeng H.M.,Chinese Academy of Sciences
Zhonghua yu fang yi xue za zhi [Chinese journal of preventive medicine] | Year: 2012

Based on the registered esophageal cancer data from 1998 to 2007, to analyze the incidence of esophageal cancer during the period and then to predict its trend between year 2008 and 2015. The incidence data of esophageal cancer between 1998 and 2007 were sorted from National Cancer Registry Database. Data from forty selected registries were qualified and recruited in the study, including 86 427 cases in total, covering 446 734 668 person years. Crude incidence rates were calculated by area and gender. The standardized incidence rate was adjusted by World Segi's population composition. JoinPoint software was applied to analyze the 10 years' incidence trend and calculated the annual percentage change, while Age-Period-Cohort Bayesian Model was used to fit the data and predict the incidence between 2008 and 2015. Between 1998 and 2007, the crude incidence rates among males and females in urban areas were separately 16.58/100 000 (28 207/170 131 309) and 7.14/100 000 (11 761/164 830 893), with standardized rates at 12.06/100 000 and 4.55/100 000, respectively. In rural areas, the crude incidence rates and the standardized rates were separately 51.98/100 000 (29 303/56 377 236) and 47.18/100 000 among males, and 30.97/100 000 (17 156/55 395 230) and 25.30/100 000 among females. During the ten years, the crude incidence trend of esophageal cancer among urban females decreased from 10.29/100 000 (1115/10 838 355) in 1998 to 6.29/100 000 (1387/22 057 787) in 2007. However, the crude incidence rate among rural males increased from 47.69/100 000 (2062/4 323 628) to 54.80/100 000 (4207/7 677 484) in the same period. And the rate among rural females and urban males did not change obviously. After adjusting population structure, in urban areas, the male incidence rate decreased by 2.1% annually and female incidence rate dropped by 7.5% annually. In rural areas, the female incidence rate fell by 1.3% annually, while the male incidence rate remained the same without significant changes. The prediction model estimated that there would be 134 474 new esophageal cancer cases diagnosed in year 2015, including 104 400 males and 30 074 females, while 52 506 cases came from urban areas and the other 81 968 cases were from rural areas. The esophageal cancer incidence showed a downtrend, especially among urban females. By year 2015, the threat of esophageal cancer will be alleviated.

Zhang X.-Y.,Chinese Academy of Sciences
Neurocomputing | Year: 2016

Correlation estimation plays a critical role in numerous applications of social network analysis. Traditionally, the numerical records of the interaction between users are used as quantitative metrics of correlation. The deficiencies are threefold. Firstly, a single source of interaction is far from sufficient to reveal the underlying correlation. Secondly, the data available are often partially observed result from the imperfection in data acquisition and storage techniques, thereby jeopardizing the reliability of estimation. Thirdly, the inference from the explicit features to the implicit correlation is far from straightforward. Simply taking interaction as correlation is neither theoretically nor practically plausible. The former issue can be addressed via matrix completion, whereas the latter is essentially a self-expressive matrix representation problem. Instead of solving the two problems separately, in this paper, we propose a simultaneous optimization algorithm for robust correlation estimation based on partially observed data. In this way, the global, rather than local, optima can be achieved in an effective manner. The experiments on both synthetic and real-world social network data demonstrate the advantage of the proposed method. © 2016 Elsevier B.V.

Chou S.-C.,Wichita State University | Gao X.-S.,Chinese Academy of Sciences
Journal of Automated Reasoning | Year: 2010

With dynamic mediums such as computer displays, we propose a new kind of visually dynamic presentation of proofs in plane geometry. In a single diagram for the proof, when the proof text goes on step by step with mouse clicks, the related geometry elements in the diagram are added, animated, or deleted dynamically with various visually dynamic effects. It solves not only the problem of identifying geometry elements in the proof text with those in the diagram, but also makes the proof more vividly visualized and intuitive. Our ongoing developing system "Java Geometry Expert" (JGEX) uses two methods to create such visually dynamic presentations: the manual input method and the automatic method. In this first part of the series of our work, we propose the main features of our visually dynamic presentation of proofs and present the manual input method to create such presentations. The manual input method mainly uses mouse clicks to create the dynamic geometry diagram and the proof text. © 2009 Springer Science+Business Media B.V.

Chen K.J.,Chinese Academy of Sciences
Zhongguo Zhong xi yi jie he za zhi Zhongguo Zhongxiyi jiehe zazhi = Chinese journal of integrated traditional and Western medicine / Zhongguo Zhong xi yi jie he xue hui, Zhongguo Zhong yi yan jiu yuan zhu ban | Year: 2011

Contemporary Chinese medicine supposes that the blood stasis is a pivotal pathogenic mechanism of coronary heart disease (CHD). The presentation and pathological changes in acute cardiovascular events of CHD, however, seem to exceed the etiological category of blood stasis. The toxin or the combination and transformation of toxin and blood stasis of Chinese medicine are involved in the pathogenesis of CHD according to the basic theory of Chinese medicine. Therefore, to establish a criterion of differentiation and diagnosis for stable CHD caused by etiological toxin of Chinese medicine applying clinical epidemiological method, which is correlated to concept of evidence based medicine, is significant in early recognizing high risk patients and improving treatment of CHD.

He Q.,Stowers Institute for Medical Research | He Q.,Chinese Academy of Sciences | Johnston J.,Stowers Institute for Medical Research | Zeitlinger J.,Stowers Institute for Medical Research | Zeitlinger J.,University of Kansas
Nature Biotechnology | Year: 2015

Understanding how eukaryotic enhancers are bound and regulated by specific combinations of transcription factors is still a major challenge. To better map transcription factor binding genome-wide at nucleotide resolution in vivo, we have developed a robust ChIP-exo protocol called ChIP-nexus (chromatin immunoprecipitation experiments with nucleotide resolution through exonuclease, unique barcode and single ligation), which utilizes an efficient DNA self-circularization step during library preparation. Application of ChIP-nexus to four proteins - human TBP and Drosophila NFkB, Twist and Max - shows that it outperforms existing ChIP protocols in resolution and specificity, pinpoints relevant binding sites within enhancers containing multiple binding motifs, and allows for the analysis of in vivo binding specificities. Notably, we show that Max frequently interacts with DNA sequences next to its motif, and that this binding pattern correlates with local DNA-sequence features such as DNA shape. ChIP-nexus will be broadly applicable to the study of in vivo transcription factor binding specificity and its relationship to cis-regulatory changes in humans and model organisms. © 2015 Nature America, Inc. All rights reserved.

Luo J.,Beijing University of Chinese Medicine | Xu H.,Chinese Academy of Sciences
Evidence-based Complementary and Alternative Medicine | Year: 2012

Objective. The aim of this overview was to summarize the outcome measures of Chinese herbal medicine (CHM) as the treatment of coronary heart disease (CHD) based on available systematic reviews (SRs), so as to display the current situation and evaluate the potential benefits and advantages of CHM on CHD. Methods. An extensive search included the Cochrane Database of Systematic Reviews, MEDLINE, and 4 databases in Chinese. SRs of CHM for CHD were included. Besides evaluating and summarizing the outcome measures, we also estimated the quality of the included reviews by PRISMA (preferred reporting items for systematic reviews and meta-analyses). Data were extracted according to predefined inclusion criteria by two independent reviewers. Results. 46 articles were included. 20 kinds of CHM were reviewed. 7 SRs were concerned with myocardial infarction (MI), 38 SRs were related to angina pectoris. 11 SRs had primary endpoints, while others focused on secondary endpoints to evaluate CHM for CHD such as angina pectoris and electrocardiogram (ECG). One SR reported more adverse effects of CHM for CHD and of the SRs analyzed quality of life. Many CHM appeared to have significant effect on improving symptoms, ECG, biomarkers and so on. However, most SRs failed to make a definite conclusion for the effectiveness of CHM in CHD patients due specifically to the poor evidence. And according to PRISMA we found most of the trials in the SRs were of low quality. Conclusion. Primary endpoints were not used widely. The benefits of CHM for CHD need to be confirmed in the future with RCTs of more persuasive primary endpoints and high-quality SRs. Copyright © 2012 Jing Luo and Hao Xu.

Shi Z.,Peking University | Zhang B.,Peking University | Cui Y.,Peking University | Jiao N.,Peking University | Jiao N.,Chinese Academy of Sciences
Angewandte Chemie - International Edition | Year: 2010

(Figure Presented) A cut and shut job: The highly selective title reaction proceeds, using O2 as the oxidant, to afford tetrahydroquinoline derivatives. This chemistry offers a new approach to polysubstituted 4, 5-dihydrocyclopenta[c]quinolines, and also valuable mechanistic insight into this ring-expansion reaction. © 2010 Wiley-VCH Verlag GmbH & Co. KGaA.

Chen H.-F.,Chinese Academy of Sciences
IEEE Transactions on Automatic Control | Year: 2010

For the multivariate ARMAX system A(z)yk=B(z)u k-1+C(z)wk recursive algorithms are proposed for estimating coefficients of A(z), B(z), and C(z) and the covariance matrix R w of wk, assuming that the orders of A(z), B(z), and C(z) are known and the control uk can be arbitrarily chosen. The new method consists in on-line solving the algebraic equations associated with ARMAX on the basis of observed data. The algorithms are easily computable, and the almost sure convergence of the algorithms is proved under reasonable conditions. © 2006 IEEE.

Shi Z.,Peking University | Tang C.,Peking University | Jiao N.,Peking University | Jiao N.,Chinese Academy of Sciences
Advanced Synthesis and Catalysis | Year: 2012

A rhodiumACHTUNGTRENUNG(III)-catalyzed direct dehydrogenative annulation of benzamides with alkynes through chelating-assisted C-H activation has been developed. Naphthylamide and isoquinolinone derivatives can be chemoselectively obtained by this protocol. © 2012 Wiley-VCH Verlag GmbH&Co. KGaA, Weinheim.

Wu Q.,Huazhong University of Science and Technology | Cao X.,Chinese Academy of Sciences | Wang D.-X.,Huazhong University of Science and Technology
Astrophysical Journal | Year: 2011

We investigate the correlation between 151MHz radio luminosity, L 151 MHz, and jet power, P jet, for a sample of low-power radio galaxies, of which the jet power is estimated from X-ray cavities. The jet power for a sample of Fanaroff-Riley I radio galaxies (FR Is) is estimated with the derived empirical correlation. We find that P jet/L Edd is positively correlated with for FR Is, where L Edd is the Eddington luminosity and L 2-10 keV X is the 2-10keV X-ray luminosity. We calculate the jet power of a hybrid model, as a variant of a Blandford-Znajek model proposed by Meier, based on the global solution of the advection-dominated accretion flow (ADAF) surrounding a Kerr black hole (BH). Our model calculations suggest that the maximal jet power is a function of the mass accretion rate and the BH spin parameter j. The hard X-ray emission is believed to be mainly from the ADAFs in FR Is, and the mass accretion rate is therefore constrained with the X-ray emission in our ADAF model calculations. We find that the dimensionless angular momentum of BH j ≳ 0.9 is required in order to reproduce the observed relation of for FR Is. Our conclusion will be strengthened if part of the X-ray emission is contributed by the jets. Our results suggest that BHs in FR Is are rapidly spinning, which are almost not affected by the uncertainty of the BH mass estimates. © 2011. The American Astronomical Society. All rights reserved..

Shi G.,KTH Royal Institute of Technology | Johansson K.H.,KTH Royal Institute of Technology | Hong Y.,Chinese Academy of Sciences
IEEE Transactions on Automatic Control | Year: 2013

In this paper, multi-agent systems minimizing a sum of objective functions, where each component is only known to a particular node, is considered for continuous-time dynamics with time-varying interconnection topologies. Assuming that each node can observe a convex solution set of its optimization component, and the intersection of all such sets is nonempty, the considered optimization problem is converted to an intersection computation problem. By a simple distributed control rule, the considered multi-agent system with continuous-time dynamics achieves not only a consensus, but also an optimal agreement within the optimal solution set of the overall optimization objective. Directed and bidirectional communications are studied, respectively, and connectivity conditions are given to ensure a global optimal consensus. In this way, the corresponding intersection computation problem is solved by the proposed decentralized continuous-time algorithm. We establish several important properties of the distance functions with respect to the global optimal solution set and a class of invariant sets with the help of convex and non-smooth analysis. © 1963-2012 IEEE.

Tong H.,Chinese Academy of Sciences | Xu R.X.,Beijing University of Technology
Astrophysical Journal Letters | Year: 2012

The spin-down behaviors of SGR 0418+5729 are investigated. The pulsar spin-down model of Contopoulos and Spitkovsky is applied to SGR 0418+5729. It is shown that SGR 0418+5729 lies below the pulsar death line and its rotation-powered magnetospheric activities may therefore have stopped. The compact star is now spun down by the magnetic dipole moment perpendicular to its rotation axis. Our calculations show that under these assumptions there is the possibility of SGR 0418+5729 having a strong dipole magnetic field, if there is a small magnetic inclination angle. Its dipole magnetic field may be much higher than the characteristic magnetic field. Therefore, SGR 0418+5729 may be a normal magnetar instead of a low magnetic field magnetar. © 2012 The American Astronomical Society. All rights reserved.

In order to understand long-term polar motion (so-called true polar wander), I present a large-scale and time-dependent solution of the Liouville equation based on the quasi-fluid approximation. The formulation includes the stabilizing effect of an oblate fossil shape memorized in an elastic lithosphere. Reorientation is assumed to be driven by a surface mass excess that is axi-symmetric and grows linearly with time. Without a fossil bulge, the time scale of true polar wander (specifically the time scale to settle to an equilibrium state) depends mainly on the time to build the load and its final magnitude. A fossil bulge works against reorientation such that the initial latitude of load emplacement now also influences the time scale. I conclude that it is necessary to consider where a load is emplaced in order to reconstruct paleo-poles on a planetary body with a remnant rotational bulge. © 2012 Elsevier Inc.

Richardson J.D.,Massachusetts Institute of Technology | Wang C.,Chinese Academy of Sciences
Astrophysical Journal Letters | Year: 2012

Voyager 2 (V2) entered the heliosheath in 2007 August at roughly the same time solar minimum conditions were reaching the outer heliosphere. Soon after crossing the termination shock the solar wind density at Voyager decreased by a factor of two and the temperature decreased by a factor of three. At the beginning of 2011 the plasma density in the heliosheath began to increase and in mid-2012 it was up by more than a factor of two. The temperature rose by about 50% and the speed remained constant, although the flow direction continues to turn tailward. These changes may signal the end of solar minimum conditions at V2 in the heliosheath, although we do not understand why the speed did not decrease. The increased dynamic pressure has lead to an outward movement of the termination shock from its very compressed state at solar minimum. © 2012. The American Astronomical Society. All rights reserved.

Seifert C.,Heidelberger Institute For Theoretische Studien Ggmbh | Grater F.,Heidelberger Institute For Theoretische Studien Ggmbh | Grater F.,Chinese Academy of Sciences
Biophysical Journal | Year: 2012

Heat-shock protein 90 (Hsp90) is an ubiquitous chaperone that is essential for cell function in that it promotes client-protein folding and stabilization. Its function is tightly controlled by an ATP-dependent large conformational transition between the open and closed states of the Hsp90 dimer. The underlying allosteric pathway has remained largely unknown, but it is revealed here in atomistic detail for the Escherichia coli homolog HtpG. Using force-distribution analysis based on molecular-dynamics simulations (>1 μs in total), we identify an internal signaling pathway that spans from the nucleotide-binding site to an ∼2.3-nm-distant region in the HtpG middle domain, that serves as a dynamic hinge region, and to a putative client-protein-binding site in the middle domain. The force transmission is triggered by ATP capturing a magnesium ion and thereby rotating and bending a proximal long α-helix, which represents the major force channel into the middle domain. This allosteric mechanism is, with statistical significance, distinct from the dynamics in the ADP and apo states. Tracking the distribution of forces is likely to be a promising tool for understanding and guiding experiments of complex allosteric proteins in general. © 2012 Biophysical Society.

Chen Z.,Beijing University of Chinese Medicine | Xu H.,Chinese Academy of Sciences
Evidence-based Complementary and Alternative Medicine | Year: 2014

Tanshinone IIA (Tan II A) is widely used in the treatment of cardiovascular diseases as an active component of Salvia miltiorrhiza Bunge. It has been demonstrated to have pleiotropic effects for atherosclerosis. From the anti-inflammatory and immunomodulatory mechanism perspective, this paper reviewed major progresses of Tan IIA in antiatherosclerosis research, including immune cells, antigens, cytokines, and cell signaling pathways. Copyright © 2014 Z. Chen and H. Xu.

Wei H.,Chinese Academy of Sciences | Wang Z.,University of North Carolina at Chapel Hill
Wiley Interdisciplinary Reviews: RNA | Year: 2015

With generations of efforts to understand RNA functions in diverse cellular processes, RNA-binding proteins (RBPs) have emerged to be one of the central players in regulating RNA-related pathways. RBPs control almost all aspects of RNA processing via recognizing their RNA target(s). Most of these proteins have a modular configuration, with one or more RNA-binding domain for target recognition and various functional modules to affect the metabolism and biological functions of RNA. Thus, engineering RNA-binding factors with customized specificity and function is extremely useful in biological and medical research. In this review, we discuss the current advances in engineering RBPs that specifically bind to diverse targets, with emphasis on the design strategies and their applications as new biological tools in various aspects of RNA metabolism and function. © 2014 John Wiley & Sons, Ltd.

Deng X.-M.,Chinese Academy of Sciences
Research in Astronomy and Astrophysics | Year: 2012

For tracking spacecraft and performing radio science, the transformation between the proper time (τ) given by a clock carried onboard a spacecraft and the barycentric coordinate time (TCB) is investigated under IAU resolutions. In order to more clearly demonstrate manifestations of a physical model and improve computational efficiency, an analytic approach is adopted. After numerical verification, it is confirmed that this method is adequate to describe a Mars orbiter during one year, and is particularly good at describing the influence from perturbing bodies. Further analyses demonstrate that there are two main effects in the transformation: the gravitational field of the Sun and the velocity of the spacecraft in the barycentric coordinate reference system. The combined contribution of these effects is at the level of a few sub-seconds. © 2012 National Astronomical Observatories of Chinese Academy of Sciences and IOP Publishing Ltd..

Liu S.,Chinese Academy of Sciences
Publications of the Astronomical Society of Australia | Year: 2012

Chromospheric brightening and H surges are evident and common phenomena along sunspot light bridges. In this paper, a coronal jet ejection from a sunspot light bridge is presented. Using data from the Solar Dynamics Observatory and Hinode satellites, it is confirmed that the jet has its root near the light bridge. This suggests that the jet may be a result of reconnection between the main sunspot and the light bridge. Due to the processing of jet ejecta, the intensity and width of the light bridge show changes to some extent. This also suggests that the jet is related to the interaction between light bridge and umbra, possibly owing to magnetic reconnection or heated plasma trapped in the light bridge escaping and moving along field lines. © 2012 Astronomical Society of Australia.

Niedzwiecki A.,University of Lodz | Ste pnik A.,University of Lodz | Xie F.-G.,Chinese Academy of Sciences
Astrophysical Journal | Year: 2015

We study the X-ray spectra of tenuous, two-temperature accretion flows using a model involving an exact, Monte Carlo computation of the global Comptonization effect as well as a general relativistic description of both the flow structure and radiative processes. In our previous work, we found that in flows surrounding supermassive black holes, thermal synchrotron radiation is not capable of providing a sufficient seed photon flux to explain the X-ray spectral indices as well as the cut-off energies measured in several best-studied active galactic nuclei (AGNs). In this work, we complete the model by including seed photons provided by nonthermal synchrotron radiation and we find that it allows us to reconcile the hot flow model with the AGN data. We take into account two possible sources of nonthermal electrons. First, we consider e± produced by charged-pion decay, which should always be present in the innermost part of a two-temperature flow due to proton-proton interactions. We find that for a weak heating of thermal electrons (small δ) the synchrotron emission of pion-decay e± is much stronger than the thermal synchrotron emission in the considered range of bolometric luminosities, L ∼ (10-4-10-2) LEdd. The small-δ model including hadronic effects, in general, agrees with the AGN data, except for the case of a slowly rotating black hole and a thermal distribution of protons. For large δ, the pion-decay e± have a negligible effect and, in this model, we consider nonthermal electrons produced by direct acceleration. We find an approximate agreement with the AGN data for the fraction of the heating power of electrons, which is used for the nonthermal acceleration η ∼ 0.1. However, for constant η and δ, the model predicts a positive correlation of the X-ray spectral index with the Eddington ratio, and hence a fine tuning of η and/or δ with the accretion rate is required to explain the negative correlation observed at low luminosities. We note a significant difference between the dependence of plasma parameters, Te and τ, on the Eddington ratio that is predicted by the large- and small-δ models. This may be the key property allowing for the estimation of the value of δ. However, a precise measurement of the spectral cut-off is required, and we note that differences between results available in the literature are similar in magnitude to the difference between the model predictions. In flows surrounding stellar-mass black holes, the synchrotron emission of pion-decay e± exceeds the thermal synchrotron only above ∼0.01 LEdd. Furthermore, in such flows, the nonthermal synchrotron radiation is emitted at energies of ≳1 keV, and therefore the Compton cooling is less efficient than in flows surrounding supermassive black holes. This may explain spectral differences between AGNs and black-hole transients around ∼0.01 LEdd (the latter being typically much harder). © 2015. The American Astronomical Society. All rights reserved.

Lin W.,Fudan University | Lin W.,Chinese Academy of Sciences | Ma H.,Fudan University
IEEE Transactions on Automatic Control | Year: 2010

This paper investigates complete synchronization of unidirectionally and adaptively coupled systems with discrete and distributed time delays. Instead of the conventional hypothesis of a uniform Lipschitz condition on the system's vector fields, only a local Lipschitz condition is adopted. It is proved that the local complete synchronization can be achieved through a unidirectional and adaptive coupling, and that the global complete synchronization can be realized when the nonlinear degree of the vector fields is smaller than some derived critical value. The results are illustrated in some representative models with time delays. Also considered is complete synchronization with an exponential convergence rate on the adaptively coupled time-delayed systems with vector fields that are one-sided uniformly Lipschitz (systems of this type can admit time-varying discrete and distributed delays). All the results can be further generalized to various types of synchronization between bidirectionally coupled time-delayed systems or among delayed kinetic systems of a complex network. © 2006 IEEE.

Li Y.,Nanjing University | Ding M.D.,Nanjing University | Qiu J.,Montana State University | Cheng J.X.,Chinese Academy of Sciences
Astrophysical Journal | Year: 2015

Chromospheric evaporation refers to dynamic mass motions in flare loops as a result of rapid energy deposition in the chromosphere. These motions have been observed as blueshifts in X-ray and extreme-ultraviolet (EUV) spectral lines corresponding to upward motions at a few tens to a few hundreds of km s-1. Past spectroscopic observations have also revealed a dominant stationary component, in addition to the blueshifted component, in emission lines formed at high temperatures (∼10 MK). This is contradictory to evaporation models predicting predominant blueshifts in hot lines. The recently launched Interface Region Imaging Spectrograph (IRIS) provides high-resolution imaging and spectroscopic observations that focus on the chromosphere and transition region in the UV passband. Using the new IRIS observations, combined with coordinated observations from the EUV Imaging Spectrometer, we study the chromospheric evaporation process from the upper chromosphere to the corona during an X1.0 flare on 2014 March 29. We find evident evaporation signatures, characterized by Doppler shifts and line broadening, at two flare ribbons that are separating from each other, suggesting that chromospheric evaporation takes place in successively formed flaring loops throughout the flare. More importantly, we detect dominant blueshifts in the high-temperature Fe xxi line (∼10 MK), in agreement with theoretical predictions. We also find that, in this flare, gentle evaporation occurs at some locations in the rise phase of the flare, while explosive evaporation is detected at some other locations near the peak of the flare. There is a conversion from gentle to explosive evaporation as the flare evolves. © 2015. The American Astronomical Society. All rights reserved..

Guo J.H.,CAS National Astronomical Observatories | Guo J.H.,Chinese Academy of Sciences
Astrophysical Journal | Year: 2011

A multi-fluid model for an atomic hydrogen-proton mixture in the upper atmosphere of an extrasolar planet is presented when the continuity and momentum equations of each component have already been solved with an energy equation. The particle-number density, temperature distribution, and structure of velocity can be found by using the model. I chose two special objects, HD 209458b and HD 189733b, for discussion and concluded that their predicted mass-loss rates are consistent with those observed. The most important physical process in coupling each component is the charge exchange, which couples atomic hydrogen tightly with protons. Most of the hydrogen escapes from hot Jupiters as protons, especially in the young star-planet system. I found that the single-fluid model can describe the escape of particles when the mass-loss rate is higher than a few times 109gs-1, while below 109gs -1 the multi-fluid model is more suitable because of the decoupling of particles. Assuming an energy limit, I found that the predicted mass-loss rates of HD 189733b are a factor of 10 larger than those calculated by my models because of a high degree of ionization. For ionized wind, which is mainly composed of protons, assuming an energy limit is no longer effective. I fitted the mass-loss rates of the ionized wind as a function of F UV by calculating the variation of the mass-loss rates with UV fluxes. © 2011. The American Astronomical Society. All rights reserved.

Yu C.,CAS Yunnan Astronomical Observatory | Yu C.,Chinese Academy of Sciences
Astrophysical Journal | Year: 2011

Motivated by coronal mass ejection studies, we construct general relativistic models of a magnetar magnetosphere endowed with strong magnetic fields. The equilibrium states of the stationary, axisymmetric magnetic fields in the magnetar magnetosphere are obtained as solutions of the Grad-Shafranov equation in a Schwarzschild spacetime. To understand the magnetic energy buildup in the magnetar magnetosphere, a generalized magnetic virial theorem in the Schwarzschild metric is newly derived. We carefully address the question whether the magnetar magnetospheric magnetic field can build up sufficient magnetic energy to account for the work required to open up the magnetic field during magnetar giant flares. We point out the importance of the Aly-Sturrock constraint, which has been widely studied in solar corona mass ejections, as a reference state in understanding magnetar energy storage processes. We examine how the magnetic field can possess enough energy to overcome the Aly-Sturrock energy constraint and open up. In particular, general relativistic (GR) effects on the Aly-Sturrock energy constraint in the Schwarzschild spacetime are carefully investigated. It is found that, for magnetar outbursts, the Aly-Sturrock constraint is more stringent, i.e., the Aly-Sturrock energy threshold is enhanced due to the GR effects. In addition, neutron stars with greater mass have a higher Aly-Sturrock energy threshold and are more difficult to erupt. This indicates that magnetars are probably not neutron stars with extreme mass. For a typical neutron star with mass of 1-2 M ∞, we further explore the cross-field current effects, caused by the mass loading, on the possibility of stored magnetic field energy exceeding the Aly-Sturrock threshold. © 2011. The American Astronomical Society. All rights reserved.

Ma Y.-Z.,University of British Columbia | Ma Y.-Z.,Canadian Institute for Theoretical Astrophysics | Zhao G.-B.,Chinese Academy of Sciences | Zhao G.-B.,University of Portsmouth
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics | Year: 2014

We investigate the imprint of dark energy on the kinetic Sunyaev-Zel'dovich (kSZ) angular power spectrum on scales of ℓ = 1000 to 10. 000, and find that the kSZ signal is sensitive to the dark energy parameter. For example, varying the constant w by 20% around w=-1 results in a ≳10% change on the kSZ spectrum; changing the dark energy dynamics parametrized by wa by ±0.5, a 30% change on the kSZ spectrum is expected. We discuss the observational aspects and develop a fitting formula for the kSZ power spectrum. Finally, we discuss how the precise modeling of the post-reionization signal would help the constraints on patchy reionization signal, which is crucial for measuring the duration of reionization. © 2014 Elsevier B.V.

Yu H.-D.,Institute of Materials Research and Engineering of Singapore | Zhang Z.,Chinese Academy of Sciences | Han M.-Y.,Institute of Materials Research and Engineering of Singapore | Han M.-Y.,National University of Singapore
Small | Year: 2012

The annual cost of corrosion has been increasing globally, and it has now reached beyond 3% of the world's gross domestic product. It remains a challenge to reduce or prevent unwanted corrosion effectively after many decades of effort. Nowadays, more efforts are being made to develop anti-corrosion platforms for decreasing the huge cost of corrosion. In parallel, it is also highly expected to be able to use corrosion for producing useful materials with reduced energy consumption. In this review, recent progress in how methods for controlling metal corrosion can be used to produce structure-diversified nanomaterials are summarized along with a presentation of their applications. As a valuable addition to the scientists' toolbox, metal corrosion strategies can be applied to different metals and their alloys for the production of various nanostructured materials; this also provides insights into how metal corrosion can be further prevented and into how corrosion wastage can be reduced. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Li T.,University of Chinese Academy of Sciences | Shi Y.,University of Chinese Academy of Sciences | Shi Y.,Chinese Academy of Sciences
Optics Express | Year: 2015

The well-known diffractive-imaging-based optical cryptosystem is breached in the paper. The decryption key of the system can be easily accessed by the opponent by using a new type of powerful phase retrieval method. Our result, to our best knowledge, is the first work to show the security risk of the diffractive-image cryptosystem. Meanwhile, we provide a set of numerical simulations to demonstrate the feasibility and robustness of the presented method. ©2015 Optical Society of America.

Li Z.,Peking University | Li Z.,Chinese Academy of Sciences
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2012

We note that the theoretical prediction of neutrinos from gamma-ray bursts (GRBs) by IceCube overestimates the GRB neutrino flux, because they ignore both the energy dependence of the fraction of proton energy transferred to charged pions and the radiative energy loss of secondary pions and muons when calculating the normalization of the neutrino flux. After correction, GRB neutrino flux is reduced by a factor ∼5 for typical GRB spectral parameters and may be consistent with the present zero event detected by IceCube. More observations are important to push the sensitivity below the prediction and test whether GRBs are the sources of ultrahigh energy cosmic rays. © 2012 American Physical Society.

Dong H.-R.,CAS Institute of High Energy Physics | Feng F.,Peking University | Jia Y.,CAS Institute of High Energy Physics | Jia Y.,Chinese Academy of Sciences
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2012

We investigate the O(α sv2) correction to the e +e -→J/ψ+η c process in the nonrelativistic QCD (NRQCD) factorization approach. Within some reasonable choices of the relative order-v2 NRQCD matrix elements, we find that including this new ingredient of correction only mildly enhances the existing NRQCD predictions. We have also deduced the asymptotic expressions for the O(α sv2) short-distance coefficients, and reconfirm the early speculation that at next-to-leading order in α s, the double logarithm of type ln2(s/mc2) appearing in various NRQCD short-distance coefficients is always associated with the helicity-suppressed channels. © 2012 American Physical Society.

Deng X.-M.,Chinese Academy of Sciences | Deng X.-M.,Nanjing University | Xie Y.,Nanjing University
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2012

Within the framework of the scalar-tensor theory, its second post-Newtonian (2PN) approximation is obtained with Chandrasekhar's approach. By focusing on an N-point mass system as the first step, we reduce the metric to its 2PN form for light propagation. Unlike previous works, at 2PN order, we abandon the hierarchized hypothesis and do not assume two parametrized post-Newtonian parameters γ and β to be unity. We find that although there exist γ and β in the 2PN metric, only γ appears in the 2PN equations of light. As a simple example for applications, a gauge-invariant angle between the directions of two incoming photons for a differential measurement is investigated after the light trajectory is solved in a static and spherically symmetric spacetime. It shows the deviation from the general relativity δθ STT does not depend on β even at 2PN level in this circumstance, which is consistent with previous results. A more complicated application is light deflection in a 2-point mass system. We consider a case that the light propagation time is much less than the time scale of its orbital motion and thus treat it as a static system. The 2-body effect at 2PN level originating from relaxing the hierarchized hypothesis is calculated. Our analysis shows the 2PN 2-body effect in the Solar System is one order of magnitude less than future ∼1nano-arcsecond experiments, while this effect could be comparable with first post-Newtonian component of δθ STT in a binary system with two Sun-like stars and separation by ∼0.1AU if an experiment would be able to measure γ-1 down to ∼10 -6. © 2012 American Physical Society.

Berardi M.,Harvard University | Chou J.,Harvard University | Chou J.,Chinese Academy of Sciences
Cell Metabolism | Year: 2014

Modulation of cellular energy expenditure is fundamental to normal and pathological cell growth and differentiation. Mitochondria stores energy as a proton gradient across their inner membrane. Uncoupling proteins (UCPs) can dissipate the gradient to produce heat or regulate metabolite fluxes. UCP-mediated proton currents require fatty acids (FAs) and are blocked by nucleotides, but the molecular basis of these processes is unknown. We find, by nuclear magnetic resonance and functional mutagenesis, that UCP2 can bind FAs laterally through its peripheral site, and this intramembrane molecular recognition is essential for UCP2-catalyzed FA flipping across the membrane, which in turn is essential for proton translocation. The antagonist GDP binds inside the UCP2 cavity and perturbs its conformation, which can displace FA from the peripheral site as a mean of inhibiting proton currents. Our data provide a biophysical perspective of the intricate interplay ofUCPs, FA, and nucleotides in determining proton fluxes in mitochondria. Using NMR and functional mutagenesis, Berardi and Chou elucidate how the uncoupling protein UCP2 uses free fatty acids (FAs) to dissipate the proton gradient in mitochondria by acting as a FA flippase. GDP directly binds inside the UCP2 cavity and blocks fatty acid recognition, which inhibits UCP2 activation. © 2014 Elsevier Inc.

Schubert W.,Otto Von Guericke University of Magdeburg | Schubert W.,Chinese Academy of Sciences
Journal of Molecular Recognition | Year: 2014

Understanding biological systems at the level of their relational (emergent) molecular properties in functional protein networks relies on imaging methods, able to spatially resolve a tissue or a cell as a giant, non-random, topologically defined collection of interacting supermolecules executing myriads of subcellular mechanisms. Here, the development and findings of parameter-unlimited functional super-resolution microscopy are described - a technology based on the fluorescence imaging cycler (IC) principle capable of co-mapping thousands of distinct biomolecular assemblies at high spatial resolution and differentiation (<40 nm distances). It is shown that the subcellular and transcellular features of such supermolecules can be described at the compositional and constitutional levels; that the spatial connection, relational stoichiometry, and topology of supermolecules generate hitherto unrecognized functional self-segmentation of biological tissues; that hierarchical features, common to thousands of simultaneously imaged supermolecules, can be identified; and how the resulting supramolecular order relates to spatial coding of cellular functionalities in biological systems. A large body of observations with IC molecular systems microscopy collected over 20 years have disclosed principles governed by a law of supramolecular segregation of cellular functionalities. This pervades phenomena, such as exceptional orderliness, functional selectivity, combinatorial and spatial periodicity, and hierarchical organization of large molecular systems, across all species investigated so far. This insight is based on the high degree of specificity, selectivity, and sensitivity of molecular recognition processes for fluorescence imaging beyond the spectral resolution limit, using probe libraries controlled by ICs. © 2013 The Authors.

Cao D.,Chinese Academy of Sciences | Liu Z.,Henan University | Wei J.,Chinese University of Hong Kong
Archive for Rational Mechanics and Analysis | Year: 2013

In this paper, we construct stationary classical solutions of the incompressible Euler equation approximating singular stationary solutions of this equation. This procedure is carried out by constructing solutions to the following elliptic problem where p > 1, Ω ⊂ ℝ2 is a bounded domain, Ω+ i and Ω− j are mutually disjoint subdomains of Ω and χΩ+i (resp. χΩ− j ) are characteristic functions of Ω+ i (resp. Ω− j ), q is a harmonic function. We show that if Ω is a simply-connected smooth domain, then for any given C1-stable critical point of Kirchhoff–Routh function W(x+ 1, …, x+ m, x− 1, …, x− n ) with κ+ i > 0 (i = 1, …, m) and κ− j > 0 ( j = 1, …, n), there is a stationary classical solution approximating stationary m + n points vortex solution of incompressible Euler equations with total vorticity. The case that n = 0 can be dealt with in the same way as well by taking each Ω− j as an empty set and set χΩ−j ≡ 0, κ− j = 0. © 2013, Springer-Verlag Berlin Heidelberg.

Li R.B.,U.S. National Institute of Standards and Technology | Li R.B.,CAS Wuhan Institute of Physics and Mathematics | Li R.B.,Chinese Academy of Sciences | Deng L.,U.S. National Institute of Standards and Technology | Hagley E.W.,U.S. National Institute of Standards and Technology
Physical Review Letters | Year: 2013

We demonstrate a fast Kerr phase gate in a room-temperature Rb85 vapor using a Raman gain method where the probe wave travels " superluminally". Continuously variable, zero to π radian nonlinear Kerr phase shifts of the probe wave relative to a reference wave have been observed at 333 K. We show rapid manipulation of digitally encoded probe waves using a digitally encoded phase-control light field, demonstrating the capability of the system in information science and telecommunication applications. © 2013 American Physical Society.

Chen G.-Y.,Xinjiang University | Zhao Q.,CAS Institute of High Energy Physics | Zhao Q.,Chinese Academy of Sciences
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics | Year: 2013

We study the anomalous cross-section lineshape of e+e-→DD̄ with an effective field theory. Near the threshold, most of the DD̄ pairs are from the decay of ψ(3770). Taking into account the fact that the nonresonance background is dominated by the ψ(2. S) transition, the produced DD̄ pair can undergo final-state interactions before the pair is detected. We propose an effective field theory for the low-energy DD̄ interactions to describe these final-state interactions and find that the anomalous lineshape of the DD̄ cross section observed by the BESII Collaboration can be well described. © 2012 Elsevier B.V.

Xing Z.-Z.,CAS Institute of High Energy Physics | Xing Z.-Z.,Peking University | Xing Z.-Z.,Chinese Academy of Sciences
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics | Year: 2013

The 3×3 Maki-Nakagawa-Sakata-Pontecorvo (MNSP) lepton flavor mixing matrix may be slightly non-unitary if the three active neutrinos are coupled with sterile neutrinos. We show that it is in principle possible to test whether the relation |Ve1|2+|Ve2|2+|Ve3|2=1 holds or not in a precision reactor antineutrino oscillation experiment, such as the recently proposed Daya Bay II experiment. We explore three categories of non-unitary effects on the 3×3 MNSP matrix: 1) the indirect effect in the (3+3) flavor mixing scenario where the three heavy sterile neutrinos do not take part in neutrino oscillations; 2) the direct effect in the (3+1) scenario where the light sterile neutrino can oscillate into the active ones; and 3) the interplay of both of them in the (3+1+2) scenario. We find that both the zero-distance effect and flavor mixing factors of different oscillation modes can be used to determine or constrain the sum of |Ve1|2, |Ve2|2 and |Ve3|2 and its possible deviation from one, and the active neutrino mixing angles θ12 and θ13 can be cleanly extracted even in the presence of light or heavy sterile neutrinos. Some useful analytical results are obtained for each of the three scenarios. © 2012 Elsevier B.V.

Gao S.,Chinese Academy of Sciences
Studies in History and Philosophy of Science Part B - Studies in History and Philosophy of Modern Physics | Year: 2013

According to Penrose, the fundamental conflict between the superposition principle of quantum mechanics and the principle of general covariance of general relativity entails the existence of wavefunction collapse, e.g. a quantum superposition of two different space-time geometries will collapse to one of them due to the ill-definedness of the time-translation operator for the superposition. In this paper, we argue that Penrose's conjecture on gravity's role in wavefunction collapse is debatable. First of all, it is still a controversial issue what the exact nature of the conflict is and how to resolve it. Secondly, Penrose's argument by analogy is too weak to establish a necessary connection between wavefunction collapse and the conflict as understood by him. Thirdly, the conflict does not necessarily lead to wavefunction collapse. The reason is that the conflict or the problem of ill-definedness for a superposition of different space-time geometries also needs to be solved before the collapse of the superposition finishes, and once the conflict has been resolved, the wavefunction collapse will lose its physical basis relating to the conflict. In addition, we argue that Penrose's suggestions for the collapse time formula and the preferred basis are also problematic. © 2013 Elsevier Ltd.

Su Y.,University of Graz | Veronig A.M.,University of Graz | Holman G.D.,NASA | Dennis B.R.,NASA | And 4 more authors.
Nature Physics | Year: 2013

Magnetic-field reconnection is believed to play a fundamental role in magnetized plasma systems throughout the Universe, including planetary magnetospheres, magnetars and accretion disks around black holes. This letter presents extreme ultraviolet and X-ray observations of a solar flare showing magnetic reconnection with a level of clarity not previously achieved. The multi-wavelength extreme ultraviolet observations from SDO/AIA show inflowing cool loops and newly formed, outflowing hot loops, as predicted. RHESSI X-ray spectra and images simultaneously show the appearance of plasma heated to >10 MK at the expected locations. These two data sets provide solid visual evidence of magnetic reconnection producing a solar flare, validating the basic physical mechanism of popular flare models. However, new features are also observed that need to be included in reconnection and flare studies, such as three-dimensional non-uniform, non-steady and asymmetric evolution. © 2013 Macmillan Publishers Limited. All rights reserved.

Ban X.,Chinese Academy of Sciences
Shuili Xuebao/Journal of Hydraulic Engineering | Year: 2011

Tennant method is used to attain the ecological flow requirement for Chinese sturgeon spawning habitat on the downstream of the Gezhouba Dam based on the analysis on hydrological data in recent 20 years. The results show that the optimal range is about 7800~13000 m3/s. Then, based on the survey topographic and hydraulic data, Instream Flow Incremental Method is used to make a further simulation for water depth, velocity and substrate. Habitat suitability index and GIS technique are used to connect the hydro-dynamic model and biological characteristic of Chinese sturgeon to obtain the fish habitat area as a function of stream flow for the spawning habitat. The result indicates the optimal flow range for spawning habitat is about 5000~15000 m3/s, which is validated with the surveyed flow in the spawning date annually. When the outflow is from both the Dajiang power plane and Erjiang power plant of Gezhouba Hydropower Station, the area of the spawing hahital is largest.

Kang L.,Chinese Academy of Sciences
Annual Review of Entomology | Year: 2014

Phase change in locusts is an ideal model for studying the genetic architectures and regulatory mechanisms associated with phenotypic plasticity. The recent development of genomic and metabolomic tools and resources has furthered our understanding of the molecular basis of phase change in locusts. Thousands of phase-related genes and metabolites have been highlighted using large-scale expressed sequence tags, microarrays, high-throughput transcriptomic sequences, or metabolomic approaches. However, only several key factors, including genes, metabolites, and pathways, have a critical role in phase transition in locusts. For example, CSP (chemosensory protein) and takeout genes, the dopamine pathway, protein kinase A, and carnitines were found to be involved in the regulation of behavioral phase change and gram-negative bacteria-binding proteins in prophylaxical disease resistance of gregarious locusts. Epigenetic mechanisms including small noncoding RNAs and DNA methylation have been implicated. We review these new advances in the molecular basis of phase change in locusts and present some challenges that need to be addressed. © Copyright ©2014 by Annual Reviews. All rights reserved.

Zhang L.,Tsinghua University | Xu T.,Tsinghua University | Zhao X.,Chinese Academy of Sciences | Zhu Y.,Tsinghua University
Applied Catalysis B: Environmental | Year: 2010

Highly crystalline orthorhombic Bi2MoO6 particles with high visible-light photocatalytic activity have been controllably synthesized via a facile hydrothermal process without adding any surfactant. The morphologies of Bi2MoO6 with nanosheet and microrod can be selectively obtained by adjusting the pH value of the reactant. The formation mechanisms of nanosheet and microrod structures were then discussed based on the H+ cations adsorption abilities on different crystal faces. The Bi2MoO6 samples prepared at acidic condition showed 12 times higher photocatalytic activity than that prepared at basic condition under visible-light irradiation. The reason for the big difference in the photocatalytic activities for the Bi2MoO6 samples obtained at different pH values were systematically studied based on their shape, size and the variation of local structure. © 2010 Elsevier B.V.

Zhang H.,Chinese Academy of Sciences
Zhonghua jie he he hu xi za zhi = Zhonghua jiehe he huxi zazhi = Chinese journal of tuberculosis and respiratory diseases | Year: 2012

To observe the immunohistochemical staining of IgG4 in nonspecific interstitial pneumonia (NSIP) and to study the clinicopathological features of IgG4-related NSIP. Retrospective analysis was carried out for 32 patients with NSIP who had been admitted into Peking Union Medical College Hospital from November 2002 to October 2010. The diagnosis of NSIP was established by surgical lung biopsy and all specimens were fixed in neutral formalin and embedded in paraffin. Sections were cut for HE and immunohistochemical stain. According to the diagnostic criteria for IgG4-related disease, 4 cases were confirmed to be IgG4-related NSIP. The clinicopathological features including clinical history, laboratory examination, and pathologic evaluation were studied. The 4 patients with IgG4-related NSIP included 1 man and 3 women, with a median age of 48 years (range, 44 - 56 years). The presenting symptoms were dry cough or shortness of breath. One patient (1/4, 25.0%) was found to have a positive autoantibody but no cases showed positive RF in serum. The histological finding of the 4 cases was characterized by inflammatory cell infiltration in interstitium with fibrosis, and 1 case showed obliterative arteritis. The numbers of IgG4-positive plasma cells in the 4 cases were 42/hpf, 22/hpf, 11/hpf, and 33/hpf respectively, while the percentages of IgG4-positive to IgG-positive plasma cells were 70%, 71%, 57%, 43% respectively. IgG4-related interstitial pulmonary disease can be characterized as the NSIP pattern. The pathological features of IgG4-related NSIP include infiltration of lympho-plasmacytes and eosinophils in interstitium with fibrosis, and lymphoid follicles are frequently identified in the area of lymphocyte aggregation, but obliterative arteritis is infrequently identified in the lesion. Immunohistochemical staining of IgG and IgG4 is very helpful for a definite diagnosis of IgG4-related disease.

Fan X.,Southwest University of Science and Technology | Qiao J.,Chinese Academy of Sciences
Yanshilixue Yu Gongcheng Xuebao/Chinese Journal of Rock Mechanics and Engineering | Year: 2010

The maximum horizontal distance(Lmax) and apparent coefficient of friction(Hmax/Lmax) are considered as the evaluation criteria of landslide movement. In order to analyze the landslide movement, five influence factors of large-scale seismic and rainfall landslide are considered including landslide volume(V), landslide height(H), landslide slope gradient(α), constraint angle of slope toe(θ) and ground type(X). The results show that, at the landslide maximum horizontal distance(Lmax), the landslide height H is the most important factor of rainfall landslides; and it follows by slope gradient(α), constraint angle of slope toe(θ) and ground type(X) in turn. When the volume is from 106 to 107 m3, the influence of ground type(X) on the seismic landslide is larger than rainfall landslide; and the influence factors of seismic landslides are H, X, α, θ in sequence. When the volume is larger than 107 m3, the landslide slope gradient α is the most important factor of seismic landslide; and it follows by landslide height(H), constraint angle of slope toe(θ) and ground type(X) in turn. By significant analysis, the landslide height(H) is significant influence factor of Lmax of large-scale rainfall landslide and seismic landslide with the volume from 106 to 107 m3. At landslide apparent coefficient of friction(Hmax/Lmax), the landslide slope gradient(α) is the most important factor of seismic landslides, it follows by landslide height(H), ground type(X) and constraint angle of slope toe(θ) in turn. The influence factors of rainfall landslide with the volume from 106 to 107 m3 and larger than 107 m3 are α, H, θ, X and H, α, X, θ respectively. The H, α, X are significant influence factors of Hmax/Lmax of seismic landslide with the volume larger than 107 m3 by significant analysis.

Ci W.M.,Precision for Medicine | Liu J.,Chinese Academy of Sciences
Physiology | Year: 2015

5-Methylcytosine (5mC) is a major epigenetic modification in animals. The programming and inheritance of parental DNA methylomes ensures the compatibility for totipotency and embryonic development. In vertebrates, the DNA methylomes of sperm and oocyte are significantly different. During early embryogenesis, the paternal and maternal methylomes will reset to the same state. Herein, we focus on recent advances in how offspring obtain the DNA methylation information from parents in vertebrates. ©2015 Int. Union Physiol. Sci./Am. Physiol. Soc.

Wang Y.,CAS Yantai Institute of Coastal Zone Research | Wang Y.,Chinese Academy of Sciences | Chen L.,Shandong Provincial Key Laboratory of Coastal Zone Environmental Processes
Nanomedicine: Nanotechnology, Biology, and Medicine | Year: 2011

Quantum dots (QDs) have proven themselves as powerful inorganic fluorescent probes, especially for long term, multiplexed imaging and detection. The newly developed QDs labeling techniques have facilitated the study of drug delivery on the level of living cells and small animals. Moreover, based on QDs and fluorescence imaging system, multifunctional nanocomplex integrated targeting, imaging and therapeutic functionalities have become effective materials for synchronous cancer diagnosis and treatment. In this review, we will summarize the recent advances of QDs in the research of drug delivery system from the following aspects: surface modification strategies of QDs for drug delivery, QDs as drug nanocarriers, QD-labeled drug nanocarriers, QD-based fluorescence resonance energy transfer (FRET) technique for drug release study as well as the development of multifunctional nanomedicines. Possible perspective in this field will also be discussed. © 2010 Elsevier Inc.

Gao S.,Chinese Academy of Sciences
Studies in History and Philosophy of Science Part B - Studies in History and Philosophy of Modern Physics | Year: 2013

Protective measurement is a new measuring method introduced by Aharonov, Vaidman, and Anandan, with the aim of measuring the expectation value of an observable on a single quantum system, even if the system is initially not in an eigenstate of the measured observable. According to these authors, this feature of protective measurements favors a realistic interpretation of the wave function. These claims were challenged by Uffink. He argued that only observables that commute with the system's Hamiltonian can be protectively measured, and that an allegedly protective measurement of an observable that does not commute with the system's Hamiltonian does not actually measure this observable, but rather another related one that commutes with the system's Hamiltonian. In this paper we identify a number of unresolved issues in Uffink's proofs and argue that his alternative interpretation of what happens in a protective measurement has not been justified. © 2013 Elsevier Ltd.

Feng L.,Chinese Academy of Sciences | Kang Z.,Peking University
Journal of Cosmology and Astroparticle Physics | Year: 2013

The first result of AMS-02 confirms the positron fraction excess observed by PAMELA, but the spectrum is somewhat softer than that of PAMELA. In the dark matter (DM) interpretation it brings a tension between AMS-02 and Fermi-LAT, which reported an excess of the electron plus positron flux. In this work we point out that the asymmetric cosmic ray from asymmetric dark matter (ADM) decay relaxes the tension. It is found that in the case of two-body decay a bosonic ADM around 2.4 TeV and decaying into μ-τ+ can significantly improve the fits. Based on the R-parity-violating supersymmetry with operators LLEc, we propose a minimal model to realize that ADM. The model introduces only a pair of singlets (X,) with a tiny coupling LH uX, which makes the ADM share the lepton asymmetry and decay into μ-τ+ along the operator LLEc. © 2013 IOP Publishing Ltd and Sissa Medialab srl.

Yuan Q.,Chinese Academy of Sciences | Yuan Q.,CAS Institute of High Energy Physics | Bi X.-J.,CAS Institute of High Energy Physics
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics | Year: 2013

The recently reported positron fraction up to ~350 GeV by AMS-02 seems to have tension with the total electron/positron spectra detected by Fermi and HESS, for either pulsar or dark matter annihilation/decay scenario as the primary positron sources. In this work we will show that the tension will be removed by an adjustment of the primary electron spectrum. If the primary electron spectrum becomes harder above ~50 GeV, similar as the cosmic ray nuclei spectrum, the AMS-02 positron fraction and Fermi/HESS data can be well fitted by both the pulsar and dark matter models. This result may be suggestive of a common origin of the cosmic ray nuclei and the primary electrons. Furthermore, this study also implies that the properties of the extra sources derived from the fitting to the AMS-02 data should depend on the form of background. © 2013 Elsevier B.V.

Zhang X.-S.,CAS Beijing National Laboratory for Molecular | Chen K.,CAS Beijing National Laboratory for Molecular | Shi Z.-J.,CAS Beijing National Laboratory for Molecular | Shi Z.-J.,Chinese Academy of Sciences | Shi Z.-J.,Nankai University
Chemical Science | Year: 2014

Transition metal-catalyzed direct C-H functionalization has drawn great attention in the past several decades owing to its advantages compared to conventional organic transformations, including higher atom-, step- and cost-economy and the avoidance of tedious prefunctionalization and waste emission. At the current stage, to make the C-H functionalization more applicable, chemists have devoted themselves to expanding the substrate and reaction scope. In the past decade, we exerted ourselves to develop new transformations based on direct C-H functionalization. In this minireview we report on our recent achievements on the addition of C-H bonds to carbonyls and imines. The addition of organometallic reagents, such as Grignard reagents, toward carbon-heteroatom double bonds is one of the most powerful reactions in organic synthesis to produce secondary and tertiary alcohols and amines. This chemistry is broadly used in both laboratory and industry. However, this powerful transformation suffers from some drawbacks: (1) the preparation of initial organohalides from easily available fossil feedstocks is tedious and sluggish; (2) substantial amounts of metal halide salts are emitted as waste; (3) last but not least, the manipulation of organometallic reagents is complicated due to their sensitivity to air and moisture. In contrast, direct insertion of polar double bonds to C-H bonds via transition-metal catalysis is ideal from the viewpoint of atom-, step- and cost-economy and the avoidance of the waste emission, as well as of the complex manipulation of sensitive reagents. Starting from this point, we made a commitment to this project years ago and have made credible achievements in this field. We first carried out Ir-catalyzed addition of pyridinyl C-H bonds to aldehydes promoted by silane, showing an unusual C-3 selectivity. Later on, we developed Rh-catalyzed addition of aryl C-H bonds with aldimines in the absence of any additives with directing strategy with highest atom- and step-economy. The mechanism was investigated in depth by the isolation of key intermediates and systematic thermodynamic and kinetic studies. Such a concept was expanded to the coupling of aryl/alkenyl C-H bonds with aldehydes and imines. Notably, a tandem process of relayed C-H activation/alkyne insertion/cyclization between benzoates/benzimide and alkynes was developed, indicating the potential of the direct coupling of esters and amides with C-H bonds. Ideally, this strategy opens a new window to approach the ideal reactions to produce amines and alcohols from hydrocarbons. This journal is © the Partner Organisations 2014.

Pan F.,CAS Beijing National Laboratory for Molecular | Shi Z.-J.,CAS Beijing National Laboratory for Molecular | Shi Z.-J.,Chinese Academy of Sciences
ACS Catalysis | Year: 2014

Carbon-sulfur bonds widely exist in natural products, pesticides, and drugs, and their activation, cleavage, and transformation via transition metal catalysis have become more and more important in organic chemistry. During the past several decades, great progress on transition-metal catalyzed carbon-sulfur activation of thioesters and their transformations has been achieved. Carbon-sulfur bonds linking to both heteroaryl and aryl groups can be cleaved to construct carbon-carbon bonds by coupling reactions or to construct carbon-hydrogen bonds by reductions. This perspective is focused on recent advances in cleavage and transformations of transition-metal-catalyzed carbon-sulfur bonds. © 2013 American Chemical Society.

Guan S.J.,Chinese Academy of Sciences
Zhongguo Zhong xi yi jie he za zhi Zhongguo Zhongxiyi jiehe zazhi = Chinese journal of integrated traditional and Western medicine / Zhongguo Zhong xi yi jie he xue hui, Zhongguo Zhong yi yan jiu yuan zhu ban | Year: 2012

To study the acute toxicity of the water extracts (ERWE) and 60% ethanol extracts (EREE) from different processed products of Radix Polygalae (crude Radix Polygalae, licorice, and honey processed Radix Polygalae), thus providing scientific evidence for toxicity study of Radix Polygalae and its safe clinical application. The ERWE and EREE were prepared from different processed products of Radix Polygalae. Their contents of saponins were respectively determined. The poisoning condition and death of the mice administered with ERWE and EREE by gastrogavage were observed within fourteen days. The modified Karber's method was used to calculate LD50 and 95% confidence interval (CI). The EREE of licorice processed Radix Polygalae had the maximum toxicity with highest content of saponins, while the ERWE of honey processed Radix Polygalae had the minimum toxicity with lowest content of saponins. Different processing methods have effects on the contents of saponins in Radix Polygalae. The experiment showed that the toxicity of Radix Polygalae is in direct proportion to the content of saponins. The higher the saponins contents, the higher the toxicity.

Zhao X.,Chinese Academy of Sciences | Dryer M.,National Oceanic and Atmospheric Administration
Space Weather | Year: 2014

One of the major solar transients, coronal mass ejections (CMEs) and their related interplanetary shocks have severe space weather effects and become the focus of study for both solar and space scientists. Predicting their evolutions in the heliosphere and arrival times at Earth is an important component of the space weather predictions. Various kinds of models in this aspect have been developed during the past decades. In this paper, we will present a view of the present status (during Solar Cycle 24 in 2014) of the space weather's objective to predict the arrival of coronal mass ejections and their interplanetary shock waves at Earth. This status, by implication, is relevant to their arrival elsewhere in the solar system. Application of this prediction status is clearly appropriate for operational magnetospheric and ionospheric situations including A - > B - > Csolar system missions. We review current empirical models, expansion speed model, drag-based models, physics-based models (and their real-time prediction's statistical experience in Solar Cycle 23), and MHD models. New observations in Solar Cycle 24, including techniques/models, are introduced as they could be incorporated to form new prediction models. The limitations of the present models and the direction of further development are also suggested. © 2014. American Geophysical Union. All Rights Reserved.

Wang W.G.,Chinese Academy of Sciences
Dong wu xue yan jiu = Zoological research / "Dong wu xue yan jiu" bian ji wei yuan hui bian ji | Year: 2012

Tupaia belangeri are small mammals with a squirrel-like appearance; they were formerly classified under the primates order despite the lack of derived features characteristic of primates. Given that T. belangeri are easy to raise, cheap to maintain, and have a small body size, a high reproductive rate, and close affinity to primates, these animals would be used as an alternative to primates in biomedical research. Three-month old T. belangeri chineses were infected with enterovirus 71 (EV71) via three different routes, namely, oral administration, nasal dripping, and tail intravenous injection, to study the infection in infant T. belangeri and find a feasible scheme to make them an ideal animal model of EV71 in place of primates. Daily activities were regularly observed, body temperatures were measured, and blood tests were conducted. Blood and fecal samples were regularly collected. The infection was examined via the neutralizing antibody test, reverse transcription polymerase chain reaction (RT-PCR), Real-Time PCR, and pathological analysis. The temperature, as well as the white blood cell count and the number of lymphocytes, increased four days after infection. Virus loads were determined in all three groups, and the peak appeared on, before, or after the tenth day, respectively. Thus, oral administration proved to be the best route. The highest serum antibody titer obtained was 1:16. Acute paralysis with urinary retention manifested after about two weeks, and pathological changes were observed in the brain, heart, lung, spleen, kidney, and other tissues. In conclusion, T. belangeri chineses can infected with EV71 via oral administration, nasal dripping, and tail intravenous injection. Therefore, T. belangeri are potential EV71 animal models for further studies on the mechanism of pathogenesis or vaccine evaluation.

Li S.A.,Chinese Academy of Sciences
Dong wu xue yan jiu = Zoological research / "Dong wu xue yan jiu" bian ji wei yuan hui bian ji | Year: 2012

Animal models are essential for the development of new anti-infectious drugs. Although some bacterial infection models have been established in rodents, small primate models are rare. Here, we report on two bacterial infection models established in tree shrew (Tupaia belangeri chinensis). A burnt skin infection model was induced by dropping 5×10(6) CFU of Staphylococcus aureus on the surface of a wound after a third degree burn. This dose of S. aureus caused persistent infection for 7 days and obvious inflammatory response was observed 4 days after inoculation. A Dacron graft infection model, 2×10(6) CFU of Pseudomonas aeruginosa also caused persistent infection for 6 days, with large amounts of pus observed 3 days after inoculation. These models were used to evaluate the efficacy of levofloxacin (LEV) and cefoperazone (CPZ), which reduced the viable bacteria in skin to 4log10 and 5log10 CFU/100 mg tissue, respectively. The number of bacteria in graft was significantly reduced by 4log10 CFU/mL treatment compared to the untreated group (P<0.05). These results suggest that two bacterial infection models were successfully established in tree shrew using P. aeruginosa and S. aureus. In addition, tree shrew was susceptible to P. aeruginosa and S. aureus, thus making it an ideal bacterial infection animal model for the evaluation of new antimicrobials.

Chang Z.,CAS Institute of High Energy Physics | Chang Z.,Chinese Academy of Sciences | Li M.-H.,CAS Institute of High Energy Physics | Wang S.,CAS Institute of High Energy Physics
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics | Year: 2013

Astronomical observations showed that there may exist a bulk flow with peculiar velocities in the universe, which contradicts with the ΛCDM model. The bulk flow reveals that the observational universe is anisotropic at large scales. In fact, a more reliable observation on the anisotropy of spacetime comes from the CMB power spectra. The WMAP and Planck satellites both show that there is a hemispherical power asymmetry at large-angular scales. In this Letter, we propose a "wind" scenario to the bulk flow (or the anisotropy of spacetime). Under the influence of the "wind", the spacetime metric could become a Finsler structure. By resolving the null geodesic equation, we obtain the modified luminosity distance, which has a dipolar form at the leading order. Thus, the "wind" describes well the bulk flow. In addition, we perform a least-χ2 fit to the data of type Ia supernovae (SNe Ia) in the Union2.1 compilation. The peculiar velocity of the bulk flow has an upper limit vbulk≲4000km/s, which is compatible with all the existing observational values. © 2013 Elsevier B.V.

Fang X.Y.,Chinese Academy of Sciences
Zhonghua liu xing bing xue za zhi = Zhonghua liuxingbingxue zazhi | Year: 2012

To group and characterize natural plague foci in China. A novel two-class typing method as well as a three-indication nomenclature method were established to group and characterize the natural plague foci, on the basis of eco-geographical landscapes of plague foci, genetics of Yersinia pestis, zoology of rodent reservoirs and the entomology of flea vectors. A total of 12 distinct natural plague foci (including 19 subtypes) as well as their biological features were characterized. Natural plague foci in China were grouped and characterized in this study.

Wang Z.,Chinese Academy of Sciences | Cui Z.,Qualcomm
IEEE Circuits and Systems Magazine | Year: 2011

Low-Density Parity-check (LDPC) code, being one of the most promising near-Shannon limit error correction codes (ECCs) in practice, has attracted tremendous attention in both academia and industry since its rediscovery in middle 1990's. Owning excellent coding gain, LDPC code also has very low error floor, and inherent parallizable decoding schemes. Compared to other ECCs such as Turbo codes, BCH codes and RS codes, LDPC code has many more varieties in code construction, which result in various optimum decoding architectures associated with different structures of the parity-check matrix. In this work, we first provide an overview of typical LDPC code structures and commonly-used LDPC decoding algorithms. We then discuss efficient VLSI architectures for random-like codes and structured LDPC codes. We further present layered decoding schemes and corresponding VLSI architectures. Finally we briefly address non-binary LDPC decoding and multi-rate LDPC decoder design. © 2006 IEEE.

Ji W.,Chinese Academy of Sciences | Zhang L.,Jilin University | Xie W.,Jilin University
Optics Letters | Year: 2012

Studies on phosphorescent organic light emitting devices (PhOLEDs) with phosphorescent emitter, fac-tris (2-phenylpyridine) iridium (Ir(ppy) 3), show that the lifetime of triplet exciton is modified by surface plasmon coupling of Au nanoparticles (NPs). Interactions between the triplet exciton and gold (Au) nanoparticles (NPs) lead to a decrease in the exciton lifetime and result in the spontaneous emission decay rate of triplet exciton faster as the distance between the phosphorescent material and the Au NPs becomes smaller. This interaction reduces the efficiency roll-off of Au NPs containing device. These results provide new guides for device design to improve efficiency performance. © 2012 Optical Society of America.

Meng H.,Chinese Academy of Sciences
Zhen ci yan jiu = Acupuncture research / [Zhongguo yi xue ke xue yuan Yi xue qing bao yan jiu suo bian ji] | Year: 2011

To Investigate the clinical efficacy of electroacupuncture (EA) at different frequencies for patients with impaired glucose tolerance (IGT). A total of 120 IGT outpatients were randomly divided into control, EA-5 Hz, EA-50 Hz, and EA-100 Hz groups (n = 30/group). EA (1 mA) was applied to bilateral Pishu (BL 20), Shenshu (BL23), Zusanli (ST 36) and Sanyinjiao (SP6) for 20 min, once daily for 60 sessions. Body mass index (BMI), fasting blood glucose (FBG) and 2-hour post-prandial blood glucose (2 h PBG) contents were detected by using BAYER Blood Sugar Analyzer and glycosylated haemoglobin (HbA1c) content was detected by enzymatic assay. Following the treatment, both HbA1c and 2 h PBG levels in the EA-5 Hz group were significantly lower than those of the control group and those of pre-treatment in the same one group (P < 0.05, P < 0.01). No significant differences were found between the EA-5 Hz and control groups, between pre-treatment and post-treatment in the EA-5 Hz group in BMI and FBG levels; between the EA-50 Hz and control groups, between the EA-100 Hz and control groups, and between pre-treatment and post-treatment in the EA-50 Hz and EA-100 Hz groups in BMI, FBG,2 h PBG and HbA1c levels (P > 0.05). Lower frequency EA of BL 20, BL 23, ST 36 and SP 9 can reduce HbA1c and 2 h PBG levels in IGT patients, suggesting a helpful effect of EA in controlling the development of diabetes.

Liu J.L.,Chinese Academy of Sciences
Zhongguo Zhong xi yi jie he za zhi Zhongguo Zhongxiyi jiehe zazhi = Chinese journal of integrated traditional and Western medicine / Zhongguo Zhong xi yi jie he xue hui, Zhongguo Zhong yi yan jiu yuan zhu ban | Year: 2010

To investigate the differential plasma protein profiles in patients with hyperlipidemia & atherosclerosis (H&A) of different patterns of phlegm-stasis syndrome (PSS) for seeking their biomarker proteins. Two-dimensional gel electrophoresis and gel screening graphical analysis were performed on plasma proteins got from 146 patients; corresponding protein spots were fetched from the gel for two-stage mass-spectrometric analysis by quadruple time-of-flight mass spectrometry; then the differential proteins for PSS were discriminated by Fisher discriminate analysis. Excepting two uncertain proteins, 7 differential proteins were screened out from the 11 differentially expressed plasma protein spots with variability over 100% in the inter-block matching. Classic analysis found that haptoglobin precursor and fibrinogen gamma chain were possibly the plasma biomarker proteins for H & A; fibrinogen beta chain and apolipoprotein A-I precursor were that set apart PSS from non-PSS; fibrinogen gamma chain, albumin and apolipoprotein A-I precursor were for phlegm syndrome; haptoglobin precursor, adrenomedullin binding protein precursor, albumin and complement component C4 were for stasis syndrome; albumin and adrenomedullin binding protein precursor were for the phlegm-stasis mutual blocking syndrome. Moreover, the above mentioned expressions of possible marker proteins had their own special rule of changing in the transforming progress of PSS. This study reported, for the first time, the existence of evident variation of functional protein constitution in different patterns of PSS, and definite compatibility being detected in some functional proteins, which may be the marker proteins for making diagnosis and prognosis of PSS in H&A. Besides, preliminary proof for the transformation of PSS has gained at the functional protein level.

Yu L.L.,Chinese Academy of Sciences
Zhen ci yan jiu = Acupuncture research / [Zhongguo yi xue ke xue yuan Yi xue qing bao yan jiu suo bian ji] | Year: 2011

Chronic stress often results in neurochemical changes in the central nervous system and may lead to the onset of depression. These neurochemical changes refer to alterations of activities of neurotransmitters, neuromediators, hormones and neuronal plasticity, etc. The underlying mechanism of acupuncture in the antidepressant effect is related to its regulatory effect on the neurochemical imbalance. In the present review, the authors summarize the progress of experimental researches on acupuncture treatment of depression from (1) monoamines neurotransmitters and their receptors, (2) gamma-aminobutyric acid and glutamate, (3) neuropeptide Y, (4) hypothalamus-pituitary-adrenal axis and hypothalamus-pituitary-throid axis activities, and (5) brain-derived neurotrophic factor. In addition, the authors also make an evaluation on the insufficiency of current studies and put forwards some suggestions on the future study.

Wang Y.,Chinese Academy of Sciences
The Cochrane database of systematic reviews | Year: 2013

The use of acupuncture for stress urinary incontinence is increasing in frequency, especially in Asian area. However, its effectiveness and side effects have not been evaluated. To assess the effectiveness and side effects of acupuncture for stress urinary incontinence in adults. We searched the Cochrane Incontinence Group Specialised Register (searched 28 January 2013), EMBASE, AMED, Chinese Biomedical Literature Database (CBM), Chinese Acupuncture Trials Register and China National Knowledge Infrastructure (CNKI) (all searched 20 February 2013). In addition, we searched the reference lists of relevant articles and contacted authors and trialists in the field. Randomised and quasi-randomised controlled trials of acupuncture interventions without other treatments for the management of stress urinary incontinence for adults. Two review authors independently assessed eligibility, trial quality and extracted data. We meta-analysed data where appropriate. We identified 17 possibly eligible studies but only one small trial with 60 women met our inclusion criteria. The trial compared acupuncture versus midodrine, a drug for treating hypotension. The risk of bias was high as there was no concealment of randomised allocation, and there was no blinding of assessment of outcome. In addition, it was not possible to blind participants or health providers to the interventions. The statistical methods were not described.More women improved in the acupuncture group (73% with acupuncture versus 33% with midodrine; risk ratio (RR) 2.20, 95% confidence interval (CI) 1.27 to 3.81) but the cure rates were low and not statistically significantly different (13% versus 7%; RR 2.00, 95% CI 0.40 to 10.11). There were adverse events in the drug group only. The effect of acupuncture for stress urinary incontinence for adults is uncertain. There is not enough evidence to determine whether acupuncture is more effective than drug treatment.

Gao S.,Chinese Academy of Sciences
Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences | Year: 2013

Energy non-conservation is a serious problem of dynamical collapse theories. In this paper, we propose a discrete model of energy-conserved wave function collapse. It is shown that the model is consistent with existing experiments and our macroscopic experience. Copyright © The Royal Society 2013.

Zhao G.-B.,Chinese Academy of Sciences | Zhao G.-B.,University of Portsmouth
Astrophysical Journal, Supplement Series | Year: 2014

Based on a suite of N-body simulations of the Hu-Sawicki model of f(R) gravity with different sets of model and cosmological parameters, we develop a new fitting formula with a numeric code, MGHalofit, to calculate the nonlinear matter power spectrum P(k) for the Hu-Sawicki model. We compare the MGHalofit predictions at various redshifts (z ≤ 1) to the f(R) simulations and find that the relative error of the MGHalofit fitting formula of P(k) is no larger than 6% at k ≤ 1 h Mpc-1 and 12% at k ∈ (1, 10] h Mpc -1, respectively. Based on a sensitivity study of an ongoing and a future spectroscopic survey, we estimate the detectability of a signal of modified gravity described by the Hu-Sawicki model using the power spectrum up to quasi-nonlinear scales. © 2014. The American Astronomical Society. All rights reserved..

Wang T.,Peking University | Jiao N.,Peking University | Jiao N.,Chinese Academy of Sciences
Journal of the American Chemical Society | Year: 2013

A novel TEMPO-catalyzed aerobic oxygenation and nitrogenation of hydrocarbons via C=C double-bond cleavage has been disclosed. The reaction employs molecular oxygen as the terminal oxidant and oxygen-atom source by metal-free catalysis under mild conditions. This method can be used for the preparation of industrially and pharmaceutically important N- and O-containing motifs, directly from simple and readily available hydrocarbons. © 2013 American Chemical Society.

Wang B.,Chinese Academy of Sciences
The Cochrane database of systematic reviews | Year: 2013

Iron deficiency and iron deficiency anaemia (IDA) are common in young children. It has been suggested that the lack of iron may have deleterious effects on children's psychomotor development and cognitive function. To evaluate the benefits of iron therapy on psychomotor development and cognitive function in children with IDA, a Cochrane review was carried out in 2001. This is an update of that review. To determine the effects of iron therapy on psychomotor development and cognitive function in iron deficient anaemic children less than three years of age. We searched the following databases in April 2013: Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, CINAHL, PsycINFO, LILACS, ClinicalTrials.gov and World Health Organization International Clinical Trials Registry Platform (ICTRP). We also searched the reference lists of review articles and reports, and ran citation searches in the Science Citation Index for relevant studies identified by the primary search. We also contacted key authors. Studies were included if children less than three years of age with evidence of IDA were randomly allocated to iron or iron plus vitamin C versus a placebo or vitamin C alone, and assessment of developmental status or cognitive function was carried out using standardised tests by observers blind to treatment allocation. Two review authors independently screened titles and abstracts retrieved from the searches and assessed full-text copies of all potentially relevant studies against the inclusion criteria. The same review authors independently extracted data and assessed the risk of bias of the eligible studies. Data were analysed separately depending on whether assessments were performed within one month of beginning iron therapy or after one month. We identified one eligible study in the update search that had not been included in the original review. In total, we included eight trials.Six trials, including 225 children with IDA, examined the effects of iron therapy on measures of psychomotor development and cognitive function within 30 days of commencement of therapy. We could pool data from five trials. The pooled difference in pre- to post-treatment change in Bayley Scale Psychomotor Development Index (PDI) between iron and placebo groups was -1.25 (95% confidence interval (CI) -4.56 to 2.06, P value = 0.65; I(2) = 33% for heterogeneity, random-effects meta-analysis; low quality evidence) and in Bayley Scale Mental Development Index (MDI) was 1.04 (95% CI -1.30 to 3.39, P value = 0.79; I(2) = 31% for heterogeneity, random-effects meta-analysis; low quality evidence).Two studies, including 160 randomised children with IDA, examined the effects of iron therapy on measures of psychomotor development and cognitive function more than 30 days after commencement of therapy. One of the studies reported the mean number of skills gained after two months of iron therapy using the Denver Developmental Screening Test. The intervention group gained 0.8 (95% CI -0.18 to 1.78, P value = 0.11, moderate quality of evidence) more skills on average than the control group. The other study reported that the difference in pre- to post-treatment change in Bayley Scale PDI between iron-treated and placebo groups after four months was 18.40 (95% CI 10.16 to 26.64, P value < 0.0001; moderate quality evidence) and in Bayley Scale MDI was 18.80 (95% CI 10.17 to 27.43, P value < 0.0001; moderate quality evidence). There is no convincing evidence that iron treatment of young children with IDA has an effect on psychomotor development or cognitive function within 30 days after commencement of therapy. The effect of longer-term treatment remains unclear. There is an urgent need for further large randomised controlled trials with long-term follow-up.

Lv C.,Chinese Academy of Sciences
Journal of insect science (Online) | Year: 2012

The potential of botanical extracts such as Celosia argenea L. (Caryophyllales: Amaranthaceae), Ricinus communis L. (Malpighiales: Euphorbiaceae), Mikania micrantha Humboldt, Bonpland & Kunth (Astrales: Asteraceae), and Catharanthus roseus (L.) G. Don (Gentianales: Apocynaceae) for the control of Brontispa longissima Gestro was evaluated in a bioassay and semi-field trial. Dose-response bioassay showed no significant difference in oral-toxicity among the extracts of C. argenea, M. micrantha, and C. roseus to larvae and adult of B. longissima. All extracts tested decreased the hatchability of B. longissima eggs. In particular, the extract of M. micrantha showed higher activity than others at the concentration of 5 mg/mL. In an antifeedant bioassay, the extract of C. argenea showed higher activity against the 1(st) larvae than that of other extracts (AF50 0.03 mg/mL), and C. roseus showed higher antifeedant activity to the 2(nd) to 5(th) larvae and adult of B. longissima (AF50 0.34, 0.33, 0.11, 0.43, and 0.20 mg/mL, respectively). The semi-field trial indicated that all extracts used in this study might reduce the pest population. Extracts of C. argenea and M. micrantha showed higher activities than that of C. roseus and R communis, and the decrease in population was 75.56% and 80.00% (without Abbott's correction) after seven days of treatment, respectively, at a concentration of 20 mg/mL. Therefore, these active botanical extracts may possess potential for use in control of B. longissima.

Fan Y.-Z.,Copenhagen University | Fan Y.-Z.,Chinese Academy of Sciences
Monthly Notices of the Royal Astronomical Society | Year: 2010

In this work, we numerically calculate the thermal radiation efficiency of the baryonic outflow. The possible outflow acceleration in the transparent stage, which lowers thermal radiation efficiency, has been taken into account. In the standard internal shock model for the prompt emission, the fast shells should move with a typical Lorentz factor ~5 Γi otherwise the γ -ray burst (GRB) efficiency will be in disagreement with the observations, where Γi is the bulk Lorentz factor of the shocked/emitting region. The photosphere radius of these fast shells is small and the thermal radiation is too strong to be effectively outshone by the internal shock emission. This is particularly the case for some extremely bright events having Γi ~ 103, like GRBs 080319B and 080916C. The absence of a distinct thermal component in the spectrum of most GRBs challenges the standard internal shock model and may suggest a non-baryonic (magnetic) outflow component. Though the magnetic outflow model seems favoured by more and more data, it can hardly reproduce the typical GRB spectrum. In the photosphere-gradual magnetic dissipation scenario, the spectrum cuts off at ~1 GeV, too low to account for the observations of GRBs 080916C. In the sudden magnetic energy dissipation model, the low- energy spectrum is expected to be Fν ∝ ν-1/2, too soft to be consistent with the data Fν ∝ ν0. We speculate that the low-energy spectrum puzzle could be unveiled by the mechanism that particles, in the magnetic dissipation process, are repeatedly accelerated. © 2010 The Authors. Journal compilation © 2010 RAS.

Zhu L.,Chinese Academy of Sciences
China and World Economy | Year: 2011

China's small farmers face increasing challenges because of land and water resource constraints and the effects of climate change. With the strengthened agricultural stimulus policies, poverty reduction and social protection programs, as well as the expanding international food trade, up to now China has achieved food security through small farm agriculture. During intensive economic restructuring, smallholders still coexist with large-sized farms and industrialized agricultural businesses, but are in a vulnerable position in market transactions. Oriented to 2050, China's agricultural development and food security policies should work to improve domestic market structure, to further release international trade control and to empower smallholders. © 2011 The Author China & World Economy © 2011 Institute of World Economics and Politics, Chinese Academy of Social Sciences.

Xu J.-J.,Chinese Academy of Sciences | Xu J.-J.,CAS Changchun Institute of Optics and Fine Mechanics and Physics
Chinese Optics | Year: 2015

A new method for fast image registration based on improved Harris-Sift algorithm is proposed. Firstly, classic Harris algorithm is improved by building Gaussian scale space to extract scale invariant Harris corners and they are refined to sub-pixel corners using Forsnter algorithm. Then the SIFT descriptor is utilized to characterize those feature points and the matching procedure is carried out via randomized kd trees. At last, RANSAC is used to remove wrong matches and the optimal transform parameters are estimated using the least square method to accomplish the image registration process. The experimental results demonstrate that compared with the classic SIFT algorithm the proposed method decreases the cost time of the registration procedure mostly by 64% while almost keeping the same performance. © 2015, Editorial Office of Chinese Optics. All right reserved.

Zhang Y.,Yale University | Jiang G.,Chinese Academy of Sciences | Sauler M.,Yale University | Lee P.J.,Yale University
FASEB Journal | Year: 2013

The lung endothelium is a major target for inflammatory and oxidative stress. Heme oxygenase-1 (HO-1) induction is a crucial defense mechanism during oxidant challenges, such as hyperoxia. The role of lung endothelial HO-1during hyperoxia in vivo is not well defined. We engineered lentiviral vectors with microRNA (miRNA) sequences controlled by vascular endothelium cadherin (VE-cad) to study the specific role of lung endothelial HO-1. Wild-type (WT) murine lung endothelial cells (MLECs) or WT mice were treated with lentivirus and exposed to hyperoxia (95% oxygen). We detected HO-1 knockdown (∼55%) specifically in the lung endothelium. MLECs and lungs showed approximately a 2-fold increase in apoptosis and ROS generation after HO-1 silencing. We also demonstrate for the first time that silencing endothelial HO-1 has the same effect on lung injury and survival as silencing HO-1 in multiple lung cell types and that HO-1 regulates caspase 3 activation and autophagy in endothelium during hyperoxia. These studies demonstrate the utility of endothelial-targeted gene silencing in vivo using lentiviral miRNA constructs to assess gene function and that endothelial HO-1 is an important determinant of survival during hyperoxia. © FASEB.

Li H.Y.,Chinese Academy of Sciences
Alternative therapies in health and medicine | Year: 2010

This study aims to gain an overview of the active fields of acupuncture research in the last 5 to 10 years and before that. Document co-citation clustering analysis method was used in this article. ISI web of knowledge-SCI-EXPANDED was used to retrieve the cited references of the documents published under the topic "acupuncture." In order to identify the highly frequently cited articles, the cited references were ranked by occurrence frequency; the frequent threshold value of highly frequently cited articles was set at 20, and their cumulative frequency percentage was nearly 10%. In order to identify the correlation between these highly frequently cited articles, a references co-occurrence matrix was constructed and then transformed into a correlation matrix for co-citation cluster analysis with SPSS 11.5 (SPSS Inc, Chicago, Illinois). Between 2006 and 2008, 985 original articles involving acupuncture were published, and their nearly 20000 references were downloaded. Forty-one frequently cited references ranging from 1976 to 2005 were identified, and a 41x41 co-citation matrix was acquired. The active fields of acupuncture research were identified after co-citation cluster analysis. The active fields in the last 5 to 10 years and previously could be identified as follows. (1) Clinical research on acupuncture; (a) studies on the safety of acupuncture; (b) the quest for the "placebo" needle and assessment of the placebo effect; (c) assessment of the efficacy of acupuncture for chronic back pain, osteoarthritis of the knee, and chronic headache. (2) Usage of acupuncture: (a) surveys on the trends of acupuncture use; (b) ethical guidelines of acupuncture experiments and quality assessment. (3) Experimental research on acupuncture mechanism: (a) the neurochemical basis of acupuncture analgesia and (b) evaluation of the effects of acupuncture using functional magnetic resonance imaging.

Ren Y.,Chinese Academy of Sciences
IEEE Transactions on Applied Superconductivity | Year: 2010

A superconducting magnet system that consists of a &Nb; 3Sn cable-in-conduit conductor (CICC) coil and two NbTi solenoid coils is being developed. The superconducting magnet will be capable of generating a central magnetic field of 12 T. The stored energy of the magnet is 2.05 MJ. As a result of possible misalignment between the 3Sn coil and NbTi coils during installation, there exists a radial or axial force between two types of coils. In this paper, we use the Grover's formulas with filament method to calculate the mutual inductance and its gradient between coils. Based on this method, we apply the mutual inductance gradient method to calculate the radial and axial force between coils. We confirm the validity of this method by comparing it with an exact 3-D semianalytical expression on axial force for coaxial but midplane offset coils. Results obtained by two methods are in excellent agreement. All results obtained on radial and axial forces are introduced. © 2006 IEEE.

Yu W.Y.,Chinese Academy of Sciences
Zhongguo Zhong xi yi jie he za zhi Zhongguo Zhongxiyi jiehe zazhi = Chinese journal of integrated traditional and Western medicine / Zhongguo Zhong xi yi jie he xue hui, Zhongguo Zhong yi yan jiu yuan zhu ban | Year: 2011

The syndrome differentiation standardization of Chinese medicine and treatment technologies is the premise of Chinese medicine's entry into the world. But its individualized diagnosis and therapeutic features are contrary to the specification of standardization. The achievement and existent problems in syndrome differentiation standardization of Chinese medicine and treatment technologies were summarized in this paper. The thinking ways and recommendations to solve were proposed as well.

Sun X.F.,Chinese Academy of Sciences
Zhonghua nei ke za zhi [Chinese journal of internal medicine] | Year: 2011

To investigate the clinical features and treatment protocol and prognosis for the hypophosphataemic osteomalacia related to adefovir dipivoxil. Analysis was made upon a case of patient with chronic hepatitis B developed hypophosphataemic osteomalacia after administration of adefovir dipivoxil. Literature review was carried out to survey the global prevalence of hypophosphataemic osteomalacia after administration of adefovir dipivoxil among patients with chronic hepatitis B. The clinical symptoms started paralleling to the time taking adefovir dipivoxil, and alleviated after the patient withdrawn adefovir dipivoxil 10 weeks and was given phosphorus. Meanwhile, serum inorganic phosphorus recovered to normal (0.98 mmol/L), which lowest level was 0.77 mmol/L. Systematic review of the literature showed that hyperphosphaturia related to adefovir dipivoxil was dose-dependent, time-dependent and reversible. All reported cases of hypophosphataemic osteomalacia secondary to adefovir dipivoxil (10 mg/d) were from Asian population. Adefovir dipivoxil induced hypophosphataemic osteomalacia is rarely seen in clinical practice. Those patients with chronic hepatitis B who take adefovir dipivoxil, no matter dosages, should take periodical examinations including blood calcium and serum inorganic phosphorus to monitor whether hypophosphataemic osteomalacia occurs. Other anti-virus drugs could be used when it happens.

Yang S.H.,Georgia Institute of Technology | Hu B.-G.,Chinese Academy of Sciences
IEEE Transactions on Knowledge and Data Engineering | Year: 2012

Feature selection is fundamental to knowledge discovery from massive amount of high-dimensional data. In an effort to establish theoretical justification for feature selection algorithms, this paper presents a theoretically optimal criterion, namely, the discriminative optimal criterion (DoC) for feature selection. Compared with the existing representative optimal criterion (RoC, [21]) which retains maximum information for modeling the relationship between input and output variables, DoC is pragmatically advantageous because it attempts to directly maximize the classification accuracy and naturally reflects the Bayes error in the objective. To make DoC computationally tractable for practical tasks, we propose an algorithmic framework, which selects a subset of features by minimizing the Bayes error rate estimated by a nonparametric estimator. A set of existing algorithms as well as new ones can be derived naturally from this framework. As an example, we show that the Relief algorithm [20] greedily attempts to minimize the Bayes error estimated by the k-Nearest-Neighbor (kNN) method. This new interpretation insightfully reveals the secret behind the family of margin-based feature selection algorithms [28], [14] and also offers a principled way to establish new alternatives for performance improvement. In particular, by exploiting the proposed framework, we establish the Parzen-Relief (P-Relief) algorithm based on Parzen window estimator, and the MAP-Relief (M-Relief) which integrates label distribution into the max-margin objective to effectively handle imbalanced and multiclass data. Experiments on various benchmark data sets demonstrate the effectiveness of the proposed algorithms. © 1989-2012 IEEE.

Sun B.,CAS Institute of Atmospheric Physics | Sun B.,University of Chinese Academy of Sciences | Wang H.,CAS Institute of Atmospheric Physics | Wang H.,Chinese Academy of Sciences
Journal of Climate | Year: 2014

In this study, a Lagrangian particle dispersion model, Flexible Particle (FLEXPART), is employed to simulate the trajectories of global air parcels during 2000-09 with the purpose of revealing the moisture sources of the semiarid grasslands of China, especially on precipitation days. Based on land-cover and precipitation data, two areas of semiarid grasslands are identified: one in North China and one in the Tibetan Plateau. Using the FLEXPART simulation results, air parcels reaching these two target regions are traced back for 10 days to examine their temporal variations in position (longitude, latitude, and altitude) and specific humidity. The moisture sources of these semiarid grasslands are discussed for different precipitation categories. Moreover, the contributions of different moisture sources to the precipitation in the target regions are computed and compared. The results indicate that the moisture released in the target regions is substantially from the Eurasian continent, in both summer and winter. During May-September, the southern and eastern adjacent land areas seem to be the main moisture sources of rainfall in the grasslands of North China, while the Eurasian continent on the north and west tends to be the predominant contributor to the rainfall over the grasslands of the eastern Tibetan Plateau. During October-April, moistures released in both target regions principally originate from the Eurasian continent on the north and west. Overall, although the moisture uptake over oceanic sources is also considerable, most released moisture over the target regions is from the Eurasian continent throughout the year, while little of the contribution of oceanic sources is due to great loss of moisture en route. © 2014 American Meteorological Society.

Wei W.Q.,Chinese Academy of Sciences
Zhonghua yu fang yi xue za zhi [Chinese journal of preventive medicine] | Year: 2010

To describe the mortality of esophageal cancer (EC) in China during 2004 - 2005, and its trends over past 30 years. The Third National Retrospective Sampling Survey of Death Causes in 2004 - 2005 was covered 142 660 482 person years (72 970 241 person years in male, 69 690 241 person years in female; 47 899 806 person years in urban, 94 760 676 person years in rural). All death records of EC cases were selected. Crude, age-adjusted mortality, the proportion to all cancer deaths, and age-standardized death rate by Chinese standard population (CASR) and world standard population (WASR) were calculated. The statistic indexes of mortality were compared with those of previous retrospective death surveys in 1973 - 1975 and 1990 - 1992. During 2004 - 2005, the crude death rate of EC was 15.21/100 000 (21 694/142 660 482), CASR was 9.98/100 000, EC death accounted for 11.19% (21 694/193 841) and ranked fourth of all cancer death causes. The CASR of male (14.32/100 000, 15 067 cases) was higher than that of female (5.75/100 000, 6627 cases). In rural areas, there were 16 437 deaths caused by EC with CASR of 12.01/100 000, it was higher than in urban areas (CASR was 6.48/100 000, 5257 deaths). There were little different of EC mortality among Eastern, Central and Western areas in China. EC crude death rate in Eastern was the highest with rate of 16.67/100 000 (8761/52 556 694) and the lowest rate was 12.92/100 000 (5209/40 322 563) in Western area. EC crude death rate was increased by age increasing and reached the peak with mortality of 180.55/100 000 (1984/1 098 885) at age group of 80-. The CASR of EC was reduced by 41.64% compared with the first survey (CASR was 17.10/100 000) in 1973 - 1975, and reduced by 33.56% compared with the second survey (CASR was 15.02/100 000) in 1990 - 1992. Although the EC mortality has dropped obviously in the past three decades, it is still the main cancer burden, especially in rural areas. EC prevention and control should be focused on the rural high risk areas in China in future.

Chao J.,CAS Institute of High Energy Physics | Chu P.,CAS Institute of High Energy Physics | Chu P.,Shanghai JiaoTong University | Huang M.,CAS Institute of High Energy Physics | Huang M.,Chinese Academy of Sciences
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2013

The recently discovered inverse magnetic catalysis around the critical temperature indicates that some important information is missing in our current understanding of conventional chiral dynamics of QCD, which is enhanced by the magnetic field. In this work, we provide a mechanism to explain that the inverse magnetic catalysis around Tc is induced by sphalerons. At high temperatures, sphaleron transitions between distinct classical vacua cause an asymmetry in the chiral number density due to the axial anomaly of QCD. In the presence of a strong magnetic field, the chiral imbalance is enhanced and destroys the pairings between the different chiralities, which naturally lowers the critical temperature of the chiral phase transition for increasing magnetic field. The inverse magnetic catalysis at finite baryon density and the critical end point in the presence of a strong magnetic field is also explored in this work. © 2013 American Physical Society.

Richardson J.D.,Massachusetts Institute of Technology | Richardson J.D.,Chinese Academy of Sciences
Astrophysical Journal | Year: 2011

The heliosheath is the shocked solar wind between the termination shock and the heliopause. Plasma properties are highly variable in this region, with factor-of-two variations of density and thermal speed on timescales from tens of minutes to hours to days. Gaussian distributions fit all the heliosheath plasma data well and are used to quantify these variations. We show that these fits can be used to compensate for data lost due to cutoffs in the instrument response and show that the flow angle in the RT plane is about 50% larger than previous determinations. The turbulent component of the flow has about 25% of the flow energy in the heliosheath, but this energy is not a significant percentage of the upstream solar wind flow energy. © 2011. The American Astronomical Society. All rights reserved.

Li M.,U.S. National Institutes of Health | Chen C.,Chinese Academy of Sciences | Davies D.R.,U.S. National Institutes of Health | Chiu T.K.,Louisiana State University Health Sciences Center
Journal of Biological Chemistry | Year: 2010

Prolyl peptidases cleave proteins at proline residues and are of importance for cancer, neurological function, and type II diabetes. Prolyl endopeptidase (PEP) cleaves neuropeptides and is a drug target for neuropsychiatric diseases such as post-traumatic stress disorder, depression, and schizophrenia. Previous structural analyses showing little differences between native and substrate-bound structures have suggested a lock-and-key catalytic mechanism. We now directly demonstrate from seven structures of Aeromonus punctata PEP that the mechanism is instead induced fit: the native enzyme exists in a conformationally flexible opened state with a large interdomain opening between the β-propeller and α/β-hydrolase domains; addition of substrate to preformed native crystals induces a large scale conformational change into a closed state with induced-fit adjustments of the active site, and inhibition of this conformational change prevents substrate binding. Absolute sequence conservation among 28 orthologs of residues at the active site and critical residues at the interdomain interface indicates that this mechanism is conserved in all PEPs. This finding has immediate implications for the use of conformationally targeted drug design to improve specificity of inhibition against this family of proline-specific serine proteases.

Zhang J.-F.,Tongren University | Xie F.-G.,Chinese Academy of Sciences
Monthly Notices of the Royal Astronomical Society | Year: 2013

Under the framework of the magnetized accretion ejection structures, we analyse the energy balance properties, and study the spectral energy distributions (SEDs) of the jet-emitting disc (JED) model for black hole X-ray transients. Various radiative processes are considered, i.e. synchrotron, bremsstrahlung, and their Comptonizations, and external Comptonization of radiation from the outer thin disc. With these cooling terms taken into account, we solve the thermal equilibrium equation self-consistently and find three solutions, of which the cold and the hot solutions are stable. Subsequently, we investigate the theoretical SEDs for these two stable solutions. We find the hot JED model can naturally explain the spectra of the Galactic microquasars in their hard states. As an example, we apply this model to the case of XTE J1118+480. © 2013 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society.

Xie Y.,Nanjing University | Deng X.-M.,Chinese Academy of Sciences | Deng X.-M.,Nanjing University
Monthly Notices of the Royal Astronomical Society | Year: 2013

The effects of the f (T) gravity have previously been investigated and constrained by using perihelion advances. As an extension of previous work and as an attempt to find more stringent constraints on its parameters, we investigate here its effects on astronomical observations and on experiments conducted in the Solar system. The expression for f (T) contains a quadratic correction of α*T2 (where α is a model parameter) and the cosmological constant. Using a spherical solution describing the Sun's gravitational field, the resulting secular evolution of planetary orbital motions, in addition to the light deflection, gravitational time delay and frequency shift are calculated up to the leading contribution. From these results, we find qualitatively that the light deflection provides a unique bound on α, without dependence on, and that the time delay experiments during inferior conjunction impose a clean constraint on, regardless of α. Based on observations and experiments, especially the supplementary advances in the perihelia provided by the INPOP10a ephemeris, we obtain the upper bounds quantitatively: |α| ≤ 1.2 × 102 m2 and || ≤ 1.8 × 10-43 m-2 which are at least 10 times tighter than the previous results.© 2013 The Authors. Published by Oxford University Press on behalf of the Royal Astronomical Society.

Tong H.,Chinese Academy of Sciences
Science China: Physics, Mechanics and Astronomy | Year: 2016

Pulsars are good clocks in the universe. One fundamental question is that why they are good clocks? This is related to the braking mechanism of pulsars. Nowadays pulsar timing is done with unprecedented accuracy. More pulsars have braking indices measured. The period derivative of intermittent pulsars and magnetars can vary by a factor of several. However, during pulsar studies, the magnetic dipole braking in vacuum is still often assumed. It is shown that the fundamental assumption of magnetic dipole braking (vacuum condition) does not exist and it is not consistent with the observations. The physical torque must consider the presence of the pulsar magnetosphere. Among various efforts, the wind braking model can explain many observations of pulsars and magnetars in a unified way. It is also consistent with the up-to-date observations. It is time for a paradigm shift in pulsar studies: from magnetic dipole braking to wind braking. As one alternative to the magnetospheric model, the fallback disk model is also discussed. © 2016, Science China Press and Springer-Verlag Berlin Heidelberg.

Xiong Y.,Chinese Academy of Sciences | Xiong Y.,Massachusetts General Hospital | Xiong Y.,Harvard University | Sheen J.,Massachusetts General Hospital | Sheen J.,Harvard University
Plant Physiology | Year: 2014

The target of rapamycin (TOR) kinase, a master regulator that is evolutionarily conserved among yeasts (Saccharomyces cerevisiae), plants, animals, and humans, integrates nutrient and energy signaling to promote cell proliferation and growth. Recent breakthroughs made possible by integrating chemical, genetic, and genomic analyses have greatly increased our understanding of the molecular functions and dynamic regulation of the TOR kinase in photosynthetic plants. TOR signaling plays fundamental roles in embryogenesis, meristem activation, root and leaf growth, flowering, senescence, and life span determination. The molecular mechanisms underlying TOR-mediated ribosomal biogenesis, translation promotion, readjustment of metabolism, and autophagy inhibition are now being uncovered. Moreover, monitoring photosynthesis-derived Glc and bioenergetics relays has revealed that TOR orchestrates unprecedented transcriptional networks that wire central metabolism and biosynthesis for energy and biomass production. In addition, these networks integrate localized stem/progenitor cell proliferation through interorgan nutrient coordination to control developmental transitions and growth. © 2014 American Society of Plant Biologists. All rights reserved.

Wang F.-Y.,Chinese Academy of Sciences
Shanghai Ligong Daxue Xuebao/Journal of University of Shanghai for Science and Technology | Year: 2011

Important issues and methods in the investigation of cyber-enabled or enhanced social movement organizations (CeSMOs) were addressed. After a brief discussion of CeSMOs and their significance in the age of connected world and social media, concepts and approaches in social computing and parallel systems were porposed to be used for CeSMOs studies. Specifically, artificial organizations were used for modeling and representation, computational experiments were applied in analysis and evaluation, and parallel execution was utilized to monitor, control, and manage CeSMOs. Based on CeSMOs, future directions and mechanisms for social computing and parallel systems were explored. Finally, remarks were presented for potential applications of proposed research work and their impacts on societal development.

Zhang X.-G.,Chinese Academy of Sciences | Zhang X.-G.,Chinese Center for Antarctic Astronomy
Monthly Notices of the Royal Astronomical Society | Year: 2013

In this paper, the properties of the proposed intermediate broad emission line region (BLR) are checked for the mapped AGN PG 0052+251. With the considerations of the apparent effects of the broad He II line on the observed broad Hβ profile, the line parameters (especially the line width and the line flux) of the observed broad Ha and the broad Hβ are carefully determined. Based on the measured line parameters, the model with two broad components applied for each observed broad Balmer line is preferred, and then confirmed by the calculated much different time lags for the inner/intermediate broad components and the corresponding virial black hole mass ratio determined by the properties of the inner and the intermediate broad components. Then, the correlation between the broad line width and the broad line flux is checked for the two broad components: one clearly strong negative correlation for the inner broad component and one positive correlation for the intermediate broad component. The different correlations for the two broad components strongly support the intermediate BLR of PG 0052+251. © 2013 The Authors. Published by Oxford University Press on behalf of the Royal Astronomical Society.

Zhang X.-G.,Chinese Academy of Sciences | Zhang X.-G.,Chinese Center for Antarctic Astronomy
Monthly Notices of the Royal Astronomical Society | Year: 2013

In this paper, we carefully check the correlation between the line width (second moment) and the line flux of the double-peaked broad Ha of the well-known mapped active galactic nucleus (AGN) 3C390.3 in order to show some further distinctions between double-peaked emitters and normal broad-line AGN. Based on the virialization assumption MBH αRBLR × V2(BLR) and the empirical relation RBLR α L~0.5, one strong negative correlation between the line width and the line flux of the double-peaked broad lines should be expected for 3C390.3, such as the negative correlation confirmed for the mapped broad-line object NGC5548, RBLR × V2x(BLR)αL~0.5 ×s2 =constant.Moreover, based on the public spectra around 1995 from the AGN WATCH project for 3C390.3, one reliable positive correlation is found between the line width and the line flux of the double-peaked broadHa. In the context of the proposed theoretical accretion disc model for double-peaked emitters, the unexpected positive correlation can be naturally explained, due to different time delays for the inner and outer parts of the disc-like broad-line region (BLR) of 3C390.3. Moreover, the virialization assumption is checked and found to be still available for 3C390.3. However, the time-varying size of the BLR of 3C390.3 cannot be expected by the empirical relation RBLR α L~0.5. In other words, the mean size of the BLR of 3C390.3 can be estimated by the continuum luminosity (line luminosity), while the continuum emission strengthening leads to the size of BLR decreasing (not increasing) in different moments for 3C390.3. Then, we compared our results of 3C390.3 with the previous results reported in the literature for the other double-peaked emitters, and found that before to clearly correct the effects from disc physical parametersvarying (such as the effects of disc precession) for long-term observed line spectra, it is not so meaningful to discussthe correlation of the line parameters of double-peaked broad lines. Furthermore, due to the probable 'external' ionizing source with so far unclear structures, it is hard to give one conclusion that the positive correlation between the line width and the line flux can be found for all double-peaked emitters, even after the considerations of disc physical parameters varying. However, once one positive correlation of broad-line parameters is found, the accretion disc origination of the broad line should be considered first. © 2012 The Author. Published by Oxford University Press on behalf of the Royal Astronomical Society.

Guo Z.-R.,Chinese Academy of Sciences
Yaoxue Xuebao | Year: 2012

Pharmacological activity and druggability are two essential factors for drug innovation. The pharmacological activity is definitely indispensable, and the druggability is destined by physico-chemical, biochemical, pharmacokinetic and safety properties of drugs. As secondary metabolites of animals, plants, microbes and marine organisms, natural products play key roles in their physiological homeostasis, self-defense, and propagation. Natural products are a rich source of therapeutic drugs. As compared to synthetic molecules, natural products are unusually featured by structural diversity and complexity, more stereogenic centers and fewer nitrogen or halogen atoms. Naturally active substances usually are good lead compounds, but unlikely meet the demands for druggability. Therefore, it is necessary to modify and optimize these structural phenotypes. Structural modification of natural products is intent to Circled digit one realize total synthesis ready for industrialization, Circled digit two protect environment and resources, Circled digit three perform chemical manipulation according to the molecular size and complexity of natural products, Circled digit four acquire novel structures through structure-activity relationship analysis, pharmacophore definition, and scaffold hopping, and Circled digit five eliminate unnecessary chiral centers while retain the bioactive configuration and conformation. The strategy for structural modification is to increase potency and selectivity, improve physico-chemical, biochemical and pharmacokinetic properties, eliminate or reduce side effects, and attain intellectual properties. This review elucidates the essence of natural products-based drug discovery with some successful examples.

Deng X.-M.,Chinese Academy of Sciences | Deng X.-M.,Nanjing University | Xie Y.,Nanjing University
Monthly Notices of the Royal Astronomical Society | Year: 2013

The Yukawa correction to the Newtonian gravitational force is accepted as a parametrization of deviations from the inverse-square law of gravity which might be caused by new physics beyond the standard model of particles and the general theory of relativity. We investigate these effects on the clock onboard a drag-free satellite: dynamics of the satellite and influence on the time transfer link. We find that the Yukawa signal in the time transfer is much more difficult to detect with the current state of clocks than those effects on the dynamics, especially the secular change of periastron, by laser ranging in the case of an artificial Earth satellite carrying a frequency standard with an orbit of a = 107 m and e = 0.01. © 2013 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society.

Zhang X.-G.,Chinese Academy of Sciences | Zhang X.-G.,Chinese Center for Antarctic Astronomy
Monthly Notices of the Royal Astronomical Society | Year: 2013

In this paper, the optical spectra index-luminosity relationship is checked for the well-known 17 individually mapped quasi-stellar objects (QSOs), in order to give one more clearer conclusion on the so far conflicting dependence of the spectral index on the luminosity for an active galactic nucleus (AGN). Unlike the global relationships based on the colour difference (photometry parameters) for samples of AGNs, a more reliable relationship is determined for the multi-epoch observed individually mapped QSOs with no contamination from the host galaxies, the line variabilities and the very different central properties. The final confirmed results are as follows. (i) No strong dependence of the optical spectral index on the continuum luminosity can be found for all 17 QSOs, besides two objects (PG 0026 and PG 1613) that have some weak trends (with 3σ confidence level) for the relationship. In other words, the common expectation that 'AGNs get bluer when they get brighter' is not so common. (ii) There are very different damped intrinsic variability time-scales for the variability modes of the optical spectral index and the continuum emission, through the well-applied damped random walk method for the AGN variability. In other words, there are some different intrinsic mechanisms controlling the variabilities of the optical spectral index and the power-law AGN continuum emission. Therefore, the much weaker dependence of the optical spectral index on the continuum luminosity can be further confirmed. © 2013 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society.

Xiao Y.,Chinese Academy of Sciences
Wei sheng wu xue bao = Acta microbiologica Sinica | Year: 2010

OBJECTIVE: To optimize the production of tiacumicin B in Dactylosporangium aurantiacum NRRL 18085, we developed a genetic manipulation system for disrupting genes involved in tiacumicin biosynthesis. METHODS: We developed a method of conjugation to transfer exotic DNA pSET152 into D. aurantiacum NRRL 18085. Using the PCR-targeting system, we disrupted a putative tiacumicin halogenase gene in vitro by "in-frame deletion" in E. coli, and then the resulting cosmid was transferred into D. aurantiacum NRRL 18085 by conjugation. RESULTS: The putative tiacumicin halogenase gene in D. aurantiacum NRRL 18085 was disrupted by in-frame deletion from a double-crossover recombination event. The resulting mutant strain lost the ability to produce tiacumicin B. CONCLUSION: We developed a genetic manipulation system for D. aurantiacum NRRL 18085, enabling the functional characterization of tiacumicin biosynthetic genes in vivo, and we offered a positive example for other Actinobacteria lacking an appropriate genetic manipulation system.

Macrophages produce a large volume of ROS (reactive oxygen species) through respiratory burst. However, the influence of iNOS [inducible NOS (nitric oxide synthase)] activation on ROS production remains unclear. In the present study, the kinetic generation of ROS in RAW264.7 murine macrophages was monitored by chemiluminescence. PMA induces a robust chemiluminescence in RAW264.7 cells, suggesting PKC (protein kinase C)-related assembly and activation of NOX (NADPH oxidase). The effects of iNOS induction on ROS production were examined. Induction of iNOS expression in RAW264.7 cells with LPS (lipopolysaccharide; 1 microg/ml) causes a significant increase in PMA-induced chemiluminescence, which could be enhanced by the NOS substrate, L-arginine, and could be abolished by the NOS inhibitor, L-NNA (NG-nitro-L-arginine). Further experiments reveal that induction of iNOS expression enhances the PMA-stimulated phosphorylation of the p47phox subunit of NOX, and promotes the relocalization of cytosolic p47phox and p67phox subunits to the membrane. Inhibition of PKCzeta by its myristoylated pseudosubstrate significantly decreased the PMA-stimulated phosphorylation of the p47phox in LPS-pretreated cells, suggesting that PKCzeta is involved in the iNOS-dependent assembly and activation of NOX. Taken together, the present study suggests that the induction of iNOS upregulates the PMA-induced assembly of NOX and leads to the enhanced production of ROS via a PKCzeta-dependent mechanism.

Fu Z.-L.,Chinese Academy of Sciences
Zidonghua Xuebao/Acta Automatica Sinica | Year: 2011

To solve the cost merging problem when multi-class cost-sensitive classification is transferred to two-class cost-sensitive classification, a cost-sensitive AdaBoost algorithm which can be applied directly to multi-class classification is constructed. The proposed algorithm is similar to real AdaBoost algorithm in algorithm flow and error estimation formula. When the costs are equal, this algorithm becomes a new real AdaBoost algorithm for multi-class classification, guaranteeing that the training error of the combination classifier could be reduced while the number of trained classifiers increased. The new real AdaBoost algorithm does not need to meet the condition that every classifier must be independent, that is to say, the independent condition of classifiers can be derived from the new algorithm, instead of being the must for current real AdaBoost algorithm for multi-class classification. The experimental results show that this new algorithm always ensures the classification result trends to the class with the smallest cost, while the existing multi-class cost-sensitive learning algorithm may fail if the costs of being erroneously classified to other classes are imbalanced and the average cost of every class is equal. The research method above provides a new idea to construct new ensemble learning algorithms, and an AdaBoost algorithm for multi-label classification is given, which is easy to operate and approximately meets the smallest error classification rate. Copyright © 2011 Acta Automatica Sinica.

Wang C.-T.,Beijing Technology and Business University | Shao J.-M.,Chinese Academy of Sciences
Plant Molecular Biology Reporter | Year: 2013

Calcium-dependent protein kinases (CDPKs) play a vital regulatory role in abiotic stress responses in plants. We isolated the ZmCK1 gene encoding a CDPK from maize seedlings. The predicted ZmCK1 protein contains a typical Ser/Thr protein kinase domain and four EF-hand calcium-binding motifs in its N-terminal and C-terminal halves, respectively. The catalytic and regulatory domains were linked by a well-conserved junction domain. A ZmCK1::hGFP fusion protein was found to localize into the cytoplasma and nucleus upon introduction into Arabidopsis mesophyll protoplasts. ZmCK1 transcription was highly activated by salt and cold, and moderately by drought and exogenous ABA in maize seedling. Isolation of the ZmCK1 promoter revealed some cis-acting elements responding to stresses. Overexpression of ZmCK1 improved drought, salt, and cold stress tolerance in transgenic Arabidopsis plants. Our results suggested that ZmCK1 produces a functional kinase that may play a regulatory role in abiotic stress response. © 2012 Springer-Verlag.

Dai C.,Zhejiang Agriculture And forestry University | Wang Y.,Zhejiang Agriculture And forestry University | Zhang X.,Chinese Academy of Sciences
Optics Express | Year: 2014

The PT-symmetric and PT-antisymmetric Akhmediev breather (AB) and Kuznetsov-Ma (KM) soliton train solutions of a (2+1)-dimensional variable-coefficient coupled nonlinear Schrödinger equation in PT-symmetric coupled waveguides with gain and loss are derived via the Darboux transformation method. From these analytical solutions, we investigate the controllable behaviors of AB and KM soliton trains in a diffraction decreasing system with exponential profile. By adjusting the relation between the maximum Zm of effective propagation distance and the peak locations Z1 of AB and KM soliton trains, we can control the restraint, maintenance and postpone excitations of AB and KM soliton trains. © 2014 Optical Society of America.

Ji L.,Smithsonian Astrophysical Observatory | Ji L.,Chinese Academy of Sciences | Smith R.K.,Smithsonian Astrophysical Observatory | Brickhouse N.S.,Smithsonian Astrophysical Observatory
Astrophysical Journal | Year: 2012

We describe the latest release of AtomDB, version 2.0.2, a database of atomic data and a plasma modeling code with a focus on X-ray astronomy. This release includes several major updates to the fundamental atomic structure and process data held within AtomDB, incorporating new ionization balance data, state-selective recombination data, and updated collisional excitation data for many ions, including the iron L-shell ions from Fe+16 to Fe +23 and all of the hydrogen- and helium-like sequences. We also describe some of the effects that these changes have on calculated emission and diagnostic line ratios, such as changes in the temperature implied by the He-like G-ratios of up to a factor of two. © 2012. The American Astronomical Society. All rights reserved.

Yuan F.,Chinese Academy of Sciences | Zhang B.,University of Nevada, Las Vegas
Astrophysical Journal | Year: 2012

Most gamma-ray bursts (GRBs) have erratic light curves, which demand that the GRB central engine launches an episodic outflow. Recent Fermi observations of some GRBs indicate a lack of the thermal photosphere component as predicted by the baryonic fireball model, which suggests a magnetic origin of GRBs. Given that powerful episodic jets have been observed along with continuous jets in other astrophysical black hole systems, here we propose an intrinsically episodic, magnetically dominated jet model for the GRB central engine. Accumulation and eruption of free magnetic energy in the corona of a differentially rotating, turbulent accretion flow around a hyperaccreting black hole lead to ejections of episodic, magnetically dominated plasma blobs. These blobs are accelerated magnetically, collide with each other at large radii, trigger rapid magnetic reconnection and turbulence, efficient particle acceleration, and radiation, and power the observed episodic prompt gamma-ray emission from GRBs. © 2012. The American Astronomical Society. All rights reserved.

Sun C.-L.,CAS Beijing National Laboratory for Molecular | Gu Y.-F.,CAS Beijing National Laboratory for Molecular | Huang W.-P.,CAS Beijing National Laboratory for Molecular | Shi Z.-J.,CAS Beijing National Laboratory for Molecular | Shi Z.-J.,Chinese Academy of Sciences
Chemical Communications | Year: 2011

Polycycles can be produced with different linkages (A, B = O, N, C, S) by constructing biaryl C-C bonds via neocuproine-KOtBu promoted cross coupling between C-Xs and C-Hs. © 2011 The Royal Society of Chemistry.

Wang C.,Chinese Academy of Sciences
Molecular genetics and genomics : MGG | Year: 2014

Bacterial blight (BB) caused by Xanthomonas oryzae pv. oryzae (Xoo) is the most devastating bacterial disease of rice (Oryza sativa L.), a staple food crop that feeds half of the world's population. In management of this disease, the most economical and effective approach is cultivating resistant varieties. Due to rapid change of pathogenicity in the pathogen, it is necessary to identify and characterize more host resistance genes for breeding new resistant varieties. We have previously identified the BB resistance (R) gene Xa23 that confers the broadest resistance to Xoo strains isolated from different rice-growing regions and preliminarily mapped the gene within a 1.7 cm region on the long arm of rice chromosome 11. Here, we report fine genetic mapping and in silico analysis of putative candidate genes of Xa23. Based on F2 mapping populations derived from crosses between Xa23-containing rice line CBB23 and susceptible varieties JG30 or IR24, six new STS markers Lj36, Lj46, Lj138, Lj74, A83B4, and Lj13 were developed. Linkage analysis revealed that the new markers were co-segregated with or closely linked to the Xa23 locus. Consequently, the Xa23 gene was mapped within a 0.4 cm region between markers Lj138 and A83B4, in which the co-segregating marker Lj74 was identified. The corresponding physical distance between Lj138 and A83B4 on Nipponbare genome is 49.8 kb. Six Xa23 candidate genes have been annotated, including four candidate genes encoding hypothetical proteins and the other two encoding a putative ADP-ribosylation factor protein and a putative PPR protein. These results will facilitate marker-assisted selection of Xa23 in rice breeding and molecular cloning of this valuable R gene.

Zhao H.-L.,Chinese Academy of Sciences | Liu R.-T.,Ningxia University
Catena | Year: 2013

In the moving sand dune of Horqin Sand Land (Inner Mongolia), the diversity of the soil macro-arthropod communities beneath the canopies of two shrub species (Caragana microphylla and Salix gordejevii) and in open areas was investigated in order to determine the effect of shrubs on these soil communities. The results showed that the shrubs facilitated the aggregation of soil macro-arthropods, resulting in significantly higher diversity and individual density of macro-arthropods in the soil beneath the shrub canopy compared to the open areas. This is known as the "bug island" effect. Although the dominant families in these three soil macro-arthropod communities were the same beneath the shrub canopy compared to open areas, many new macro-arthropod families also occurred in the shrub canopy communities, resulting in significant changes in the composition and structure of these soil communities. The "bug island" effect of the shrubs resulted from the "fertile island" effect generated by these shrubs, i.e., reduced wind velocity, retained dust and sand, increased soil litter biomass and soil moisture, improved soil texture and soil fertility. Between the two shrub species investigated C. microphylla had a greater "bug island" effect than S. gordejevii, as C. microphylla had a higher "fertile island" effect than S. gordejevii. © 2013 Elsevier B.V.

Pan F.,CAS Beijing National Laboratory for Molecular | Wang H.,Peking University | Shen P.-X.,CAS Beijing National Laboratory for Molecular | Zhao J.,Peking University | And 2 more authors.
Chemical Science | Year: 2013

A novel rhodium-catalyzed C-C bond formation was developed to construct biaryls through unreactive aryl C-S bond cleavage of thioethers with aryl boroxines. This protocol provided a supplemental method of traditional Suzuki-Miyaura coupling. This journal is © The Royal Society of Chemistry 2013.

Xu Y.-D.,Shanghai JiaoTong University | Cao X.,Chinese Academy of Sciences
Astrophysical Journal | Year: 2010

It is believed that the growth of local massive black holes was dominated by accretion during quasar phases, while a fraction of the local black hole mass was accumulated through accreting gases at very low rates. We derive the black hole mass density as a function of redshift with the bolometric luminosity function of active galactic nuclei (AGNs) assuming that massive black holes grew via accreting the circumnuclear gases, in which the derived black hole mass density is required to match the measured local black hole mass density at z = 0. Advection-dominated accretion flows (ADAFs) are supposed to be present in low-luminosity AGNs/normal galaxies, which are very hot and radiate mostly in the hard X-ray band. Most of the X-ray background (XRB) is contributed by bright AGNs, and a variety of AGN population synthesis models were developed to model the observed XRB in the last two decades. Based on our derived black hole mass density, we calculate the contribution to the XRB from the ADAFs in faint AGNs/normal galaxies with a given Eddington ratio distribution, which is mostly in the hard X-ray energy band with an energy peak at ∼200 keV. The growth of massive black holes during the ADAF phase can therefore be constrained with the observed XRB. Combining an AGN population synthesis model with our results, we find that the fitting on the observed XRB, especially at the hard X-ray energy band with ≳100 keV, is improved provided the contribution of the ADAFs in low-luminosity AGNs/normal galaxies is properly included. It is found that less than ∼15% of local massive black hole mass density was accreted during ADAF phases. We suggest that more accurate measurements of the XRB in the energy band with ≳100 keV in the future may help constrain the growth of massive black holes at their late stage. We also calculate their contribution to the extragalactic γ-ray background (EGRB), and find that less than ∼1% of the observed EGRB is contributed by the ADAFs in these faint sources. © 2010. The American Astronomical Society. All rights reserved.

To investigate the role of pre-chemotherapy hemoglobin and platelet levels in the effect of chemotherapy and prognostic outcome in patients with International Federation of Gynecology and Obstetrics (FIGO) stage Ib2-IIb cervical cancer treated with neoadjuvant chemotherapy followed by radical hysterectomy. From January 1999 to December 2010, 111 patients with FIGO stage Ib2-IIb who underwent chemosurgical treatment at the department of obstetrics and gynecology in Peking Union Medical College Hospital were reviewed. The median age of patients was 42 years (range: 21 - 68 years). The median level of prechemotherapy hemoglobin and platelet levels was 127 g/L and 266 × 10(9)/L, respectively. Chemotherapy response was evaluated according to the WHO criteria, including complete response (CR), partial response (PR), stable disease (SD) and progressive disease (PD). Patients who achieved CR or PR were defined as responder. Rates of clinical response were compared with the clinical-pathological variables using chi-square test. Multiple logistic regression was carried out to evaluate the relationship among the probability of achieving an optimal clinical response and the variables. The log-rank test was used to compare the homogeneity of progression-free survival and overall survival functions across strata defined by categories of prognostic variables. The Cox proportional hazard model was used to assess the significance of potential prognostic factors for progression-free survival and overall survival. All patients received one to three cycles of chemotherapy. After the neoadjuvant chemotherapy, 9 patients achieved CR, 77 patients PR, 23 patients SD, 2 patients PD. The overall response rate was 77.5% (86/111). By univariate analysis, the clinical response rate was associated with tumor grade (P = 0.026), deep cervical stromal invasion (P = 0.029) and positive lymph nodes (P = 0.048). By multiple logistic regression, deep cervical stromal invasion (P = 0.015) and positive lymph nodes (P = 0.031) were independent predictors of optimal clinical response. By log-rank test, 5-year overall survival rate and 5-year progression-free survival rate were associated with lymph nodes metastases status and lymphovascular invasion (P = 0.000), but not with hemoglobin and platelet levels (P > 0.05). By Cox regression model, lymph nodes metastases status and lymph-vascular space involvement (P < 0.01) were independently prognostic factors of 5-year overall survival rate and 5-year progression-free survival rate. Pretreatment hemoglobin and platelet levels were neither predictors of clinical response to chemotherapy nor prognostic factors.

Xia B.,Chinese Academy of Sciences
Cell Research | Year: 2016

The mixed lineage kinase domain-like (MLKL) protein is a key factor in tumor necrosis factor-induced necroptosis. Recent studies on necroptosis execution revealed a commitment role of MLKL in membrane disruption. However, our knowledge of how MLKL functions on membrane remains very limited. Here we demonstrate that MLKL forms cation channels that are permeable preferentially to Mg2+ rather than Ca2+ in the presence of Na+ and K+. Moreover, the N-terminal domain containing six helices (H1-H6) is sufficient to form channels. Using the substituted cysteine accessibility method, we further determine that helix H1, H2, H3, H5 and H6 are transmembrane segments, while H4 is located in the cytoplasm. Finally, MLKL-induced membrane depolarization and cell death exhibit a positive correlation to its channel activity. The Mg2+-preferred permeability and five transmembrane segment topology distinguish MLKL from previously identified Mg2+-permeable channels and thus establish MLKL as a novel class of cation channels.Cell Research advance online publication 1 April 2016; doi:10.1038/cr.2016.26. © 2016 Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences

Zhang X.,Institute of Neuroscience and State Key Laboratory of Neuroscience | Bao L.,Chinese Academy of Sciences
Neuroscience Bulletin | Year: 2012

μ-opioid receptor (MOR) agonists such as morphine are powerful analgesics used for pain therapy. However, the use of these drugs is limited by their side-effects, which include antinociceptive tolerance and dependence. Earlier studies reported that MOR analgesic tolerance is reduced by blockade of δ-opioid receptors (DORs) that interact with MORs. Recent studies show that the MOR/DOR interaction in nociceptive afferent neurons in the dorsal root ganglion may contribute to morphine analgesic tolerance. Further analysis of the mechanisms for regulating the trafficking of receptors, ion channels and signaling molecules in nociceptive afferent neurons would help to understand the nociceptive mechanisms and improve pain therapy. © 2012 Shanghai Institutes for Biological Sciences, CAS and Springer-Verlag Berlin Heidelberg.

Liu J.L.,Chinese Academy of Sciences
BMC complementary and alternative medicine | Year: 2014

Cumulating evidence has revealed the effectiveness of acupuncture therapy in relieving pain via immunoregulation. However, its underlying mechanism remains unknown. The present study was designed to determine the changes of immunogenic responses at different time-points of electroacupuncture (EA) interventions in neuropathic pain rats. The neuropathic pain model was established by ligature of the left sciatic nerve to induce chronic constriction injury (CCI). EA was applied at Zusanli (ST36) and Yanglingquan (GB34) for the EA groups. The thermal pain threshold was detected with an algesia-detector. The subgroups of plasma and splenic lymphocytes were determined via fluorescence-activated cell sorting. Specific inflammatory cytokines were assayed using an ELISA-based bead multiplex assay. The activities of splenic natural killer (NK) cells and cytotoxic T lymphocytes were detected by methyl thiazolyl tetrazolium colorimetric method. For confirming the involvement of NK cell in EA-analgesia, anti-asialo-ganglio-N-tetraosylceramide (anti-asialo-GM1) antibody was given to CCI rats before EA. Following CCI, the thermal pain threshold of the affected hind footpad was significantly decreased, and increased from the 3rd day to the 12th day after EA interventions, presenting a time-dependent tendency from the 5th day on. From day 3 to 5 of EA interventions, the percentages and activity of splenic NK cells, concentrations of splenic interleukin-2 (IL-2) and beta-endorphin (β-EP) were significantly increased. Meanwhile, the concentrations of plasma IL-2, IL-1β and gamma-interferon (IFN-γ) were significantly decreased and returned to the normal level on day 12 following EA. Plasma transforming growth factor-β (TGF-β) levels were considerably upregulated on day 5 and 12 following EA. The CD4+/CD8+ T cell ratio was markedly downregulated compared with the control and CCI groups on day 5 and returned to the normal level on day 12 following EA. After depleting NK cells by anti-asialo-GM1 antibody, the increased thermal pain threshold following EA intervention was obviously reduced. Repeated EA interventions have a time-dependent cumulative analgesic effect in neuropathic pain rats, which is closely associated with its regulatory effects on NK cells, splenic IL-2, β-EP, and plasma IL-2, IL-1β, IFN-γ and TGF-β levels.

Ding S.,Peking University | Yan Y.,Peking University | Jiao N.,Peking University | Jiao N.,Chinese Academy of Sciences
Chemical Communications | Year: 2013

The aerobic direct dehydrogenative annulation of N-iminopyridinium ylides with terminal alkynes leading to pyrazolo[1,5-a]pyridine derivatives has been developed. © 2013 The Royal Society of Chemistry.

Li Y.,CAS National Astronomical Observatories | Li Y.,Chinese Academy of Sciences
Astrophysical Journal | Year: 2012

Both observations and numerical simulations show that stellar convective motions are composed of semi-regular flows of convective rolling cells and a fully developed turbulence. Although the convective rolling cells are crucial for the properties of the stellar convection that transports heat and mixes materials in the stellar interior, their contributions have not been included in turbulent convection models proposed up to now. We simplify the structure of the convective rolling cells as a cellular pattern moving circle by circle with different angular velocities around the center, estimating their typical size by solving approximately for the temperature difference over the stationary temperature background and their average shear of velocity by evaluating approximately their kinetic energy transformed by themselves working as thermal engines from the heat involved in the convective rolling cells. We obtain a steady-state solution in the fully local equilibrium which is similar to what is obtained in the standard mixing-length theory (MLT), by applying such model assumptions to the standard k-ε model and properly choosing the model parameter c ε3. Accordingly, we propose a k-ω model to include the transport effect of turbulence in stars. Preliminary results of their applications to the sun and other stars with different masses and in different evolutionary stages show good agreements with results of the standard MLT and results of numerical simulations for the stellar convection. © © 2012. The American Astronomical Society. All rights reserved..

Yuan Q.,CAS Institute of High Energy Physics | Liu S.,Chinese Academy of Sciences | Bi X.,CAS Institute of High Energy Physics
Astrophysical Journal | Year: 2012

Shocks of supernova remnants (SNRs) are important (and perhaps the dominant) agents for the production of the Galactic cosmic rays. Recent γ-ray observations of several SNRs have made this case more compelling. However, these broadband high-energy measurements also reveal a variety of spectral shapes demanding more comprehensive modeling of emissions from SNRs. According to the locally observed fluxes of cosmic-ray protons and electrons, the electron-to-proton number ratio is known to be about 1%. Assuming such a ratio is universal for all SNRs and identical spectral shape for all kinds of accelerated particles, we propose a unified model that ascribes the distinct γ-ray spectra of different SNRs to variations of the medium density and the spectral difference between cosmic-ray electrons and protons observed from Earth to transport effects. For low-density environments, the γ-ray emission is inverse-Compton dominated. For high-density environments like systems of high-energy particles interacting with molecular clouds, the γ-ray emission is π0-decay dominated. The model predicts a hadronic origin of γ-ray emission from very old remnants interacting mostly with molecular clouds and a leptonic origin for intermediate-age remnants whose shocks propagate in a low-density environment created by their progenitors via, e.g., strong stellar winds. These results can be regarded as evidence in support of the SNR origin of Galactic cosmic rays. © 2012. The American Astronomical Society. All rights reserved..

Gao W.-H.,Nanjing Normal University | Gao W.-H.,Chinese Academy of Sciences
Astrophysical Journal | Year: 2012

Swift J164449+573451 is a peculiar outburst which is most likely powered by the tidal disruption of a star by a massive black hole. Within the tidal disruption scenario, we show that the periastron distance is considerably smaller than the disruption radius and the outflow should be launched mainly via magnetic activities (e.g., the Blandford.Znajek process), otherwise the observed long-lasting X-ray afterglow emission satisfying the relation L X ∝ M. cannot be reproduced, where LX is the X-ray luminosity and M. is the accretion rate. We also suggest that LX ∝ M. may hold in the quick decline phase of gamma-ray bursts. © 2012. The American Astronomical Society. All rights reserved..

Yu D.-G.,CAS Beijing National Laboratory for Molecular | Li B.-J.,CAS Beijing National Laboratory for Molecular | Shi Z.-J.,CAS Beijing National Laboratory for Molecular | Shi Z.-J.,Chinese Academy of Sciences
Tetrahedron | Year: 2012

In the past several decades, organic chemists have made significant contributions to approach direct C-H transformations. However, limited substrate scope and reaction classifications, harsh condition, and the use of noble and toxic late transition-metal catalysts typically with high loadings clogged its applications. This article summarizes our recent efforts to explore new reaction types and develop new catalytic systems in this field, which may open a new channel to consider organic synthesis from easily available chemicals. © 2012 Published by Elsevier Ltd.

Shen J.,Chinese Academy of Sciences | Shen J.,University of Texas at Austin | Gebhardt K.,University of Texas at Austin
Astrophysical Journal | Year: 2010

We apply the axisymmetric orbit superposition modeling to estimate the mass of the supermassive black hole (BH) and dark matter (DM) halo profile of NGC 4649. We have included data sets from the Hubble Space Telescope (HST), stellar, and globular cluster (GC) observations. Our modeling gives M ̇ = (4.5 1.0) × 109 M and M/L V, obs = 8.7 1.0 (or M/LV = 8.0 0.9 after foreground Galactic extinction is corrected). We confirm the presence of a DM halo, but the stellar mass dominates inside the effective radius. The parameters of the dark halo are less constrained due to the sparse GC data at large radii. We find that in NGC 4649 the dynamical mass profile from our modeling is consistently larger than that derived from the X-ray data over most of the radial range by roughly 60%-80%. It implies that either some forms of non-thermal pressure need to be included, the assumed hydrostatic equilibrium may not be a good approximation in the X-ray modelings of NGC 4649, or our assumptions used in the dynamical models are biased. Our new M ̇ is about 2 times larger than the previous published value; the earlier model did not adequately sample the orbits required to match the large tangential anisotropy in the galaxy center. If we assume that there is no DM, the results on the BH mass and M/L V,obs do not change significantly, which we attribute to the inclusion of HST spectra, the sparse GC kinematics, and a diffuse DM halo. Without the HST data, the significance of the BH detection is greatly reduced. © 2010 The American Astronomical Society.

Corel E.,University of Gottingen | Pitschi F.,Chinese Academy of Sciences | Morgenstern B.,University of Gottingen
Bioinformatics | Year: 2010

Motivation: Multiple sequence alignments can be constructed on the basis of pairwise local sequence similarities. This approach is rather flexible and can combine the advantages of global and local alignment methods. The restriction to pairwise alignments as building blocks, however, can lead to misalignments since weak homologies may be missed if only pairs of sequences are compared. Results: Herein, we propose a graph-theoretical approach to find local multiple sequence similarities. Starting with pairwise alignments produced by DIALIGN, we use a min-cut algorithm to find potential (partial) alignment columns that we use to construct a final multiple alignment. On real and simulated benchmark data, our approach consistently outperforms the standard version of DIALIGN where local pairwise alignments are greedily incorporated into a multiple alignment. Availability: The prototype is freely available under GNU Public Licence from E.C. Contact: ecorel@gwdg.de. © The Author 2010. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oxfordjournals.org.

Cao X.,Chinese Academy of Sciences
Astrophysical Journal | Year: 2010

A power-law time-dependent light curve for active galactic nuclei (AGNs) is expected by the self-regulated black hole growth scenario, in which the feedback of AGNs expels gas and shut down accretion. This is also supported by the observed power-law Eddington ratio distribution of AGNs. At high redshifts, the AGN life timescale is comparable with (or even shorter than) the age of the universe, which sets a constraint on the minimal Eddington ratio for AGNs on the assumption of a power-law AGN light curve. The black hole mass function (BHMF) of AGN relics is calculated by integrating the continuity equation ofmassive black hole number density on the assumption of the growth of massive black holes being dominated by mass accretion with a power-law Eddington ratio distribution for AGNs. The derived BHMF of AGN relics at z = 0 can fit the measured local mass function of the massive black holes in galaxies quite well, provided the radiative efficiency ∼0.1 and a suitable power-law index for the Eddington ratio distribution are adopted. In our calculations of the black hole evolution, the duty cycle of AGN should be less than unity, which requires the quasar life timescale τQ ≥ 5 × 108 years. © 2010. The American Astronomical Society.

Jiang T.,Chinese Academy of Sciences
Proceedings of the IEEE Conference on Decision and Control | Year: 2012

In this paper we develop a semiglobal robust output feedback controller for rotating stall and surge in axial flow compressors with certain kind of compressor characteristic uncertainties. The controller is designed by combining the backstepping control and the extended state observer (ESO). It is proven that the maximum pressure rise equilibrium can be robustly stabilized in the sense that the trajectory of closed loop system can arbitrarily close to the equilibrium after a finite time. The feasibility and effectiveness of the proposed method are further illustrated by simulating an example of a axial flow compressor with an uncertain compressor characteristic. © 2012 IEEE.

Kuang G.,Chinese Academy of Sciences
IEEE Transactions on Applied Superconductivity | Year: 2010

The Chinese National Project to develop new high magnetic field facilities began in 2008. It includes the construction of a 40 T hybrid magnet. The magnet will be built at the Chinese High Magnetic Field Laboratory (CHMFL) of the Chinese Academy of Sciences. It consists of a superconducting outsert magnet and a resistive insert magnet. The outsert magnet with a bore diameter of 580 mm at room temperature is expected to provide 11 T. It is composed of two coils: the inner coil is made of Nb3Sn cable-in-conduit-conductor (CICC), the outer coil of NbTi CICC. The insert magnet, which will be a 20 MW Florida-Bitter-type resistive magnet with a clear bore diameter of 32 mm, will produce 29 T. The construction of the hybrid magnet is scheduled to be completed in 2013. © 2006 IEEE.

Lei Y.,Chinese Academy of Sciences
Zhongguo Zhong xi yi jie he za zhi Zhongguo Zhongxiyi jiehe zazhi = Chinese journal of integrated traditional and Western medicine / Zhongguo Zhong xi yi jie he xue hui, Zhongguo Zhong yi yan jiu yuan zhu ban | Year: 2010

To explore the vascular structural and functional change in aged mice, and the intervention roles of extracts from ginseng, notoginseng and chuanxiong (Exs) on it. The mice model of natural aging was built, and all model mice were divided into 5 groups, the model group, the Vitamin E group treated with vitamin E, and the three Exs groups treated with high, middle and low dose Exs respectively. Besides, a normal control group was set up with young rats. Morphological change of aorta was observed by HE and Masson staining, levels of plasma angiotensin-II (Ang II), anti-superoxide anion, advanced glycation end products (AGEs), matrix metalloproteinase 2 (MMP-2) and tissue inhibitor of metalloproteinase 2 (TIMP-2) in vascular tissue, as well as the MMP-2/TIMP-2 were detected. Aged aortic morphologic change in model rats was ameliorated in the Exs treated groups, decreased vascular endothelial exfoliative cells and vascular smooth muscle cell (5MG) proliferation were shown in HE staining. Masson staining analysis showed relative content of collagen fibers reduced in all Exs treated groups (P < 0.05) and that of SMC decreased in high-dose Exs group (P < 0.05). Moreover, levels of vascular tissue anti-superoxide anion, TIMP-2 and MMP-2/TIM-2 ratio were obviously higher, AGEs and MMP-2 were significantly lower in all Exs treated groups than those in the model group respectively, showing statistical significance (P < 0.05). Exs can ameliorate the aged changes in aortic morphology, reduce the production of reactive oxygen species (ROS) and AGEs in vascular tissue, inhibit MMP-2 activity and regulate MMP-2/TIMP-2 equilibrium, so it reduces the vascular stiffness degree of senescent mice, decreases vascular remodeling and delays the occurrence of vascular aging ultimately.

Ward M.R.,University of Texas at Arlington | Zheng S.,Chinese Academy of Sciences
Telecommunications Policy | Year: 2012

A panel of province by year data for China from 1998 to 2007 is used to estimate own- and cross-price elasticities for fixed and mobile telephone service. Identification is achieved through the use of measures of the level of competition and privatization of the industry. Moreover, using neighboring province values ensures instrumental variable exogeneity. Estimates suggest that fixed and mobile subscriptions are fairly strong substitutes. This provides evidence for the development of competition between these platforms. © 2011 Elsevier Ltd.

Tian H.,Chinese Academy of Sciences
Zhongguo zhen jiu = Chinese acupuncture & moxibustion | Year: 2013

To observe the effect of bleeding and cupping therapy on postherpetic neuralgia (PHN) and preliminarily discuss the analgesic mechanism. Sixty-four cases of PHN were randomized into two groups, 32 cases in each one. In the bleeding and cupping group, the local pricking with syringe needle and cupping was applied in the local painful area, once every two days. And totally 8 treatments were required. In the pregabalin group, pregabalin was prescribed for oral administration, 150mg/time, twice a day. And totally 16 days of medication were required. Visual analogue scale (VAS) score and the changes of P substance content in the peripheral and local serum before and after treatment were observed in the two groups. VAS score and peripheral serum P substance after treatment were lower significantly than those before treatment in the two groups (all P<0.01). The result in the bleeding and cupping group was much more significant (P<0.01). The local serum P substance after treatment was reduced significantly than that before treatment in the bleeding and cupping group [(93.86 +/- 9.87) pg/mL vs (46.13 +/- 6.31) pg/mL, P<0.01]. Bleeding and cupping therapy achieves the definite efficacy on PHN and it can reduce significantly peripheral and local serum P substance content in the patients. It is possibly one of the mechanisms of analgesic effect.

Liu Y.,CAS Changchun Institute of Applied Chemistry | Liu Y.,Chinese Academy of Sciences | Ai K.,CAS Changchun Institute of Applied Chemistry | Lu L.,CAS Changchun Institute of Applied Chemistry
Chemical Reviews | Year: 2014

Polydopamine is fast becoming a popular polymer that is receiving increased attention from scientists from different areas of expertise. The physicochemical properties of polydopamine, as well as its potential applications are reviewed. Similar to the foot protein in mussels, polydopamine has also shown versatile adhesion capability to virtually all types of surfaces, and provides a general surface-coating strategy for researchers to functionalize some specific technique-related substrates. It easily reacts with numerous amine- and thiol-containing molecules based on Michael-type addition and Schiff base reactions and has strong metal chelating/redox capabilities, which imparts to materials with structural flexibility and the ability to tailor the coatings for producing diverse hybrid materials with specific functionalities. During investigations of the polymerization process, specific attention should be drawn to the thickness of the polydopamine film deposited on the substrates.

Jin B.,Sun Yat Sen University | Ding K.,Chinese Academy of Sciences | Pan J.,Sun Yat Sen University
Molecular Cancer Therapeutics | Year: 2014

Gain-of-function mutations of membrane receptor tyrosine kinase KIT, especially gatekeeper D816V point mutation in KIT, render kinase autoactivation, disease progression, and poor prognosis. D816V KIT is found in approximately 80% of the patients with systemic mastocytosis, and is resistant to the first and second generations of tyrosine kinase inhibitors (TKI). The purpose of this investigation was aimed at exploring whether ponatinib (AP24534), a novel effective TKI against T315I Bcr-Abl, was active against D816V KIT. We discovered that ponatinib abrogated the phosphorylation of KIT harboring either V560G (sensitive to imatinib) or D816V mutation (resistant to imatinib) and the downstream signaling transduction. Ponatinib inhibited the growth of D816V KIT-expressing cells in culture and nude mouse xenografted tumor. Ponatinib triggered apoptosis by inducing the release of cytochrome c and AIF, downregulation of Mcl-1. Furthermore, ponatinib abrogated the phosphorylation of b-catenin at the site Y654, suppressed the translocation of b-catenin, and inhibited the transcription and DNA binding of TCF and the expression of its targets (e.g., AXIN2, c-MYC, and CCND1). Moreover, ponatinib was highly active against xenografted D816V KIT tumors in nude mice and significantly prolonged the survival of mice with aggressive systemic mastocytosis or mast cell leukemia by impeding the expansion and infiltration of mast cells with imatinibresistant D814Y KIT. Our findings warrant a clinical trial of ponatinib in patients with systemic mastocytosis harboring D816V KIT. © 2014 American Association for Cancer Research.

Zhang Q.,Chinese Academy of Sciences | Damian M.F.,University of Bristol
Memory and Cognition | Year: 2010

The degree to which phonological codes constrain handwriting is at present controversial. Two experiments used a picture-word interference paradigm in which participants wrote down the names of pictures while attempting to ignore visual distractor words presented at various time intervals (SOAs). Distractors could be orthographically and phonologically related, orthographically related only, or unrelated. We found an exclusive effect of phonology at an early SOA, and orthographic priming at a later SOA. In a second experiment, we showed that the effect of phonology was diminished when writers engaged in concurrent articulatory suppression. The results suggest a role of phonology in the generation of handwritten words that is to some extent dependent on situational circumstances. © 2010 The Psychonomic Society, Inc.

Chang S.,Chinese Academy of Sciences
Zhonghua liu xing bing xue za zhi = Zhonghua liuxingbingxue zazhi | Year: 2012

To estimate the incidence, mortality and 5-year prevalence rates of lung cancer in China, in 2008. Data from 36 cancer registries and the Third National Death Survey in China (2004-2005) was used to estimate the incidence, mortality and 5-year prevalence rates of lung cancer in China in 2008. Mathematical models were used to predict the lung cancer incidence and mortality rates in the next 20 years. In 2008, the incidence of lung cancer was 522,050 (18.5%) with the incidence rate as 33.5/100,000, which ranked the first among all the cancers. Mortality of lung cancer in China was 452,813 (23.1%) with the mortality rate as 28.7/100,000, which also ranked the first among all the cancers. The 5-year prevalence rate of lung cancer in China was 487,815 (10.6%) with the proportion as 45.6/100,000, which ranked fourth among all the cancers. Lung cancer happened more frequently among people older than 45 years, particularly in males. Our data on prediction showed that the incidence and mortality of lung cancer in China would gradually increase in the next 20 years. Lung cancer was the leading cause for both incidence and mortality of all cancers in China and both kept increasing. The key population fell in those older than 45 years, particularly males, that should be under special prevention and control for lung cancer.

Li Q.,Chinese Academy of Sciences
Zhonghua liu xing bing xue za zhi = Zhonghua liuxingbingxue zazhi | Year: 2012

To estimate the incidence, mortality and 5-year prevalence rates of liver cancer in 2008, China. Data from both 36 cancer registries and the Third National Death Survey in China (2004 - 2005) were used to estimate the incidence, mortality and 5-year prevalence of liver cancer in 2008 in the country by using the mathematical models to predict the liver cancer incidence and mortality in the next 20 years. In 2008, the incident cases of liver cancer was 402 208 (14.3% of the total cancers) and the number of deaths from liver cancer was 372 079 (19.0% of the total cancers). The incidence rate was 25.7/100 000, ranking the third among all cancers. The mortality rate was 23.7/100 000, ranking the second among all the cancers. The 5-year prevalence of liver cancer was 296 082 (6.4% of the total cancers) with the proportion as 27.7/ 100 000, ranking the sixth among all the cancers. 72.8% of the liver cancer cases appeared in men and the sex ratio of male to female was 2.7:1. In terms of deaths due to liver cancer, 74.3% of them occurred in men, with sex ratio of male to female as 2.9:1. At any age group, the incidence and mortality of liver cancer among males were higher than those of females. Liver cancer happened more frequently among people older than 40 years of age, particularly among males. Data under our prediction showed that the incidence and mortality of liver cancer in China would gradually increase in the next 20 years. Liver cancer is one of the most important public health issues in China. Both incidence and mortality of liver cancer have been increasing in China. The key populations for liver cancer prevention and control programs should be those who were older than 40-year-old, particularly on men.

Chen W.Q.,Chinese Academy of Sciences
Zhonghua yu fang yi xue za zhi [Chinese journal of preventive medicine] | Year: 2012

Based on the national cancer incidence database from 1998 to 2007, to analyze the cancer incidence trend and predict the cancer burden between 2008 and 2015. We picked up the cancer incidence data of 40 cancer registry sites from National Central Cancer Registry Database between 1998 and 2007. In total, 1 109 594 cancer cases were registered, covering 446 734 668 person-year. The separate incidence by district and gender were calculated, and the standardized incidence rate was calculated by world's population age structure. The incidence trend between the 10 years was analyzed by JoinPoint software, as well as the age-percentage-changes (APC). Age-Period-Cohort Bayesian Model was applied to fit the cancer incidence data stratified by age, district and gender. The cancer incidence between 2008 and 2015 was then predicted. During the period of 1998 - 2007, in urban areas, the male cancer incidence rate was 277.61/100 000 (472 307/170 131 309), with the age standardized rate (ASR) at 202.05/100 000; while the female cancer incidence rate was 236.35/100 000 (389 586/164 830 893), with the ASR at 159.15/100 000; in rural areas, the male and female cancer incidence rates were separately 272.23/100 000 (153 478/56 377 236) and 170.09/100 000 (94 223/55 395 230), with the corresponding ASR at 244.34/100 000 and 137.90/100 000. Crude incidence rate in urban men increased from 247.00/100 000 (27 758/11 237 967) in 1998 to 305.76/100 000 (68 953/22 551 353) in 2007; while it increased from 207.37/100 000 (22 476/10 838 355) to 263.20/100 000 (58 055/22 057 787) among urban women. The crude incidence rate in rural men increased from 232.33/100 000 (10 045/4 323 628) to 303.65/100 000 (23 313/7 677 484) and it increased from 139.03/100 000 (5836/4 197 806) to 197.40/100 000 (14 850/7 522 690) among rural women. After age adjustment, the urban male APC value (95%CI) was 0.5% (-0.2% - 1.3%), showed no significantly statistical difference. However, the urban female APC value (95%CI), rural male APC value (95%CI) and rural female APC value (95%CI) were separately 1.7% (1.3% - 2.0%), 1.8% (0.9% - 2.6%) and 2.8% (1.8% - 3.7%), all showed an obvious uptrend. The outcome of Age-Period-Cohort Bayesian model predicted that by year 2015, the incidence cancer rate in urban areas will reach 309.13/100 000 (1.140 million new cases) among males and 303.79/100 000 (1.046 million new cases) among females; while in rural areas the rate will reach 288.66/100 000 (1.019 million new cases) among males and 222.59/100 000 (0.734 million new cases) among females. The cancer incidence has increased annually; the uptrend in rural areas was more obvious than it in urban areas; the uptrend in females was more obvious than it in males. It is predicted that the annual incidence will continue to increase in the next years, and effective control programs should be carried out immediately.

Zhu X.-G.,Chinese Academy of Sciences | Zhu X.-G.,CAS Institute of Plant Physiology and Ecology | Zhu X.-G.,University of Illinois at Urbana - Champaign | Long S.P.,University of Illinois at Urbana - Champaign | And 2 more authors.
Annual Review of Plant Biology | Year: 2010

Increasing the yield potential of the major food grain crops has contributed very significantly to a rising food supply over the past 50 years, which has until recently more than kept pace with rising global demand. Whereas improved photosynthetic efficiency has played only a minor role in the remarkable increases in productivity achieved in the last half century, further increases in yield potential will rely in large part on improved photosynthesis. Here we examine inefficiencies in photosynthetic energy transduction in crops from light interception to carbohydrate synthesis, and how classical breeding, systems biology, and synthetic biology are providing new opportunities to develop more productive germplasm. Near-term opportunities include improving the display of leaves in crop canopies to avoid light saturation of individual leaves and further investigation of a photorespiratory bypass that has already improved the productivity of model species. Longer-term opportunities include engineering into plants carboxylases that are better adapted to current and forthcoming CO 2 concentrations, and the use of modeling to guide molecular optimization of resource investment among the components of the photosynthetic apparatus, to maximize carbon gain without increasing crop inputs. Collectively, these changes have the potential to more than double the yield potential of our major crops. Copyright © 2010 by Annual Reviews. All rights reserved.

Guo C.,Chinese Academy of Sciences
Cancer Research and Clinic | Year: 2015

Objective: To investigate the tubulocystic carcinoma (TC) of kidney in diagnosis and differential diagnosis, clinical and pathological features. Methods: A case of TC was performed with HE and immunohistochemical staining, with review of the related literature. Results: A man of 43 years old, who was found an occupying in the upper pole of the right kidney by B ultrasound, was performed ill-circumscribed of the right kidney. A gray solid ill-circumscribed mass was found within the renal parenchyma,which was sized of 1.5 cm×1.5 cm×1.0 cm. Microscopically, the tumor showed an invasive growth, and that it was composed of small tubular and vesicular structure closely spaced with slender fibrosis mesenchymal. The epithelial cells lining the tubules and cysts were flattened, cuboidal and hobnail cells, with abundant eosinophilic cytoplasm and obvious nucleolus of Fuhrman grade 3. The tumor showed positive of cytokeratin, CD10+++and P504S+++, with low Ki-67 labeling index. Postoperative follow-up of 6 months, the patient showed no tumor recurrence and metastasis. Conclusions: TC is a special subtype of renal cell carcinoma, with a tubular and cystic structure, high nuclear grade and rare mitotic. The differential diagnosis mainly includes other renal cystic lesions. The biological behavior of TC is indolent with less recurrence and distant metastasis.

Fu H.,Tianjin University | Cao X.,Chinese Academy of Sciences | Tu Z.,University of California at Los Angeles
IEEE Transactions on Image Processing | Year: 2013

Co-saliency is used to discover the common saliency on the multiple images, which is a relatively underexplored area. In this paper, we introduce a new cluster-based algorithm for co-saliency detection. Global correspondence between the multiple images is implicitly learned during the clustering process. Three visual attention cues: contrast, spatial, and corresponding, are devised to effectively measure the cluster saliency. The final co-saliency maps are generated by fusing the single image saliency and multiimage saliency. The advantage of our method is mostly bottom-up without heavy learning, and has the property of being simple, general, efficient, and effective. Quantitative and qualitative experiments result in a variety of benchmark datasets demonstrating the advantages of the proposed method over the competing co-saliency methods. Our method on single image also outperforms most the state-of-the-art saliency detection methods. Furthermore, we apply the co-saliency method on four vision applications: co-segmentation, robust image distance, weakly supervised learning, and video foreground detection, which demonstrate the potential usages of the co-saliency map. © 1992-2012 IEEE.

The broad-line region (BLR) disappears in many low-luminosity active galactic nuclei (AGNs), the reason of which is still controversial. The BLRs in AGNs are believed to be associated with the outflows from the accretion disks. Most of the low-luminosity AGNs contain advection-dominated accretion flows (ADAFs) which are very hot and have a positive Bernoulli parameter. ADAFs are therefore associated with strong outflows. We estimate the cooling of the outflows from the ADAFs and find that the gases in such hot outflows cannot always be cooled efficiently by bremsstrahlung radiation. The ADAF may co-exist with the standard disk, i.e., the inner ADAF connects to the outer thin accretion disk at radius Rd,tr in the sources accreting at slightly lower than the critical rate mcrit (m = M/MEdd). For the ADAFs with Lbol/LEdd ≳ 0.001, a secondary small inner cold disk is suggested to co-exist with the ADAF due to the condensation process. We estimate the Compton cooling of the outflow, of which the soft seed photons either come from the outer cold disk or the secondary inner cold disk. It is found that the gas in the outflow far from the ADAF may be efficiently cooled to form BLR clouds due to the soft seed photons emitted from the cold disks, provided the transition radius of the ADAF to the outer cold disk is small [rd,tr = Rd,tr/(2GM/c2) ≳ 20] or/and the secondary small cold disk has a luminosity Lsd ≳ 0.003 LEdd. The BLR clouds can still be formed in the outflows from the outer cold thin disks, if the transition radius rtr is not very large. For the sources with Lbol/LEdd ≲ 0.001, the inner small cold disk is evaporated completely in the ADAF and the outer thin accretion disk may be suppressed by the ADAF, which leads to the disappearance of the BLR. The physical implications of this scenario on the double-peaked broad-line emitters are also discussed. © 2010. The American Astronomical Society. All rights reserved. Printed in the U.S.A.

Xu Z.,Peking University | Zhang C.,Peking University | Jiao N.,Peking University | Jiao N.,Chinese Academy of Sciences
Angewandte Chemie - International Edition | Year: 2012

A fragment-assembling strategy is used to form oxazoles from aryl acetaldehydes, amines, and molecular oxygen under mild conditions (see scheme). The transformation is highly efficient with the removal of six hydrogen atoms, including the cleavage of four C(sp3)-H bonds. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Li B.-J.,CAS Beijing National Laboratory for Molecular | Wang H.-Y.,CAS Beijing National Laboratory for Molecular | Zhu Q.-L.,CAS Beijing National Laboratory for Molecular | Shi Z.-J.,CAS Beijing National Laboratory for Molecular | Shi Z.-J.,Chinese Academy of Sciences
Angewandte Chemie - International Edition | Year: 2012

Doubled up: A rhodium(III)/copper(II) system co-catalyzes the annulation of benzimides with internal alkynes for the synthesis of indenones (see scheme; Cp*=C 5Me 5). The reaction involves an uncommon nucleophilic addition of a transition-metal-carbon bond to an imide moiety. This novel reaction provides a facile route to synthesize indenones from readily available benzimides and internal alkynes. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Wu B.,Chinese Academy of Sciences
Finite Fields and their Applications | Year: 2014

In this paper, the compositional inverses of a class of linearized permutation polynomials of the form P(x)=x+x2+tr(x/a) over the finite field F2n for an odd positive integer n, where "tr" is the trace function over F2n, are explicitly determined. © 2014 Elsevier Inc.

Ye C.,Chinese Academy of Sciences
BMC bioinformatics | Year: 2012

The very large memory requirements for the construction of assembly graphs for de novo genome assembly limit current algorithms to super-computing environments. In this paper, we demonstrate that constructing a sparse assembly graph which stores only a small fraction of the observed k-mers as nodes and the links between these nodes allows the de novo assembly of even moderately-sized genomes (~500 M) on a typical laptop computer. We implement this sparse graph concept in a proof-of-principle software package, SparseAssembler, utilizing a new sparse k-mer graph structure evolved from the de Bruijn graph. We test our SparseAssembler with both simulated and real data, achieving ~90% memory savings and retaining high assembly accuracy, without sacrificing speed in comparison to existing de novo assemblers.

Zhang Q.,CAS Wuhan Botanical Garden | Lou Z.,Chinese Academy of Sciences
Environmental Science and Policy | Year: 2011

The Three Gorges Dam (TGD) is by far the world's largest hydroelectric scheme. Due to its unprecedented magnitude, the TGD has been controversial ever since it was proposed in the early 20th century and building commenced in 1993. Recent problems, including geological disasters (e.g., landslides) in the uplands and algal blooms in the aquatic environment since the reservoir's partial filling to 156. m in 2006, suggest that the environmental challenge has never been greater than now. The environmental deterioration might be further intensified when the reservoir reaches its final water level of 175. m. Solving the environmental challenges will be essential for the sustainable development of the Three Gorges Reservoir region (TGRR), and environmental sustainability in the TGRR is a high priority for the nation considering its critical location in the Yangtze Basin, which contributes 40% of China's GDP. This article reviews primary environmental assessments for biodiversity conservation, the water environment, water level fluctuation zone, and the uplands after the partial filling in the reservoir region. It also discusses the success of mitigation efforts to date. Although there are successes in mitigation particularly in conservation of endangered plants and fishes, it seems likely that environmental conditions in the TGRR could only get worse in the short term. Building a partnership among the TGD stakeholders, including local residents, governments, and international communities is necessary to meet the mounting environmental challenge in the TGRR and beyond. © 2011 Elsevier Ltd.

Qin C.,Peking University | Shen T.,Peking University | Tang C.,Peking University | Jiao N.,Peking University | Jiao N.,Chinese Academy of Sciences
Angewandte Chemie - International Edition | Year: 2012

Ironing it out: An efficient and convenient nitrogenation strategy involving C-C bond cleavage for the straightforward synthesis of versatile arylamines is presented. Various alkyl azides and alkylarenes, including the common industrial by-product cumene, react using this protocol. Moreover, this method provides a potential strategy for the degradation of polystyrene. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Zhu X.-G.,Chinese Academy of Sciences
Journal of Biotechnology | Year: 2010

Photosynthesis produces the basic building block for crop biomass and yields; however, improving photosynthesis has not been effectively used as a breeding goal. More and more evidences suggested that improving photosynthesis can substantially increase crop yields. The complexity of photosynthesis however makes experimentally identifying new ways to engineer higher photosynthesis inherently time-consuming and costly. Combining systems modeling with evolutionary algorithm makes it possible to identify optimal engineering options for future global climate change scenarios and simultaneously consider environmental constraints, such as with constant or even decreasing nitrogen fertilizer application in the field. This method enables in silico examination of a large number of engineering options which natural selection has not explored, for higher photosynthetic energy conversion efficiency. The new approach comes particularly timely for now when our society is facing serious challenges in food security and global climate change. The traditional reductionist's approach will continue generating critical knowledge required to support this systems biology method to engineering higher photosynthesis. © 2010 Elsevier B.V.

Ding S.,Peking University | Jiao N.,Peking University | Jiao N.,Chinese Academy of Sciences
Angewandte Chemie - International Edition | Year: 2012

Often used as a common solvent for chemical reations and utilized widely in industry as a reagent, N,N-dimethylformamide (DMF) has played an important role in organic synthesis for a long time. Numerous highly useful articles and reviews discussing its utilizations have been published. With a focus on the performance of DMF as a multipurpose precursor for various units in numerous reactions, this Minireview summarizes recent developments in the employment of DMF in the fields of formylation, aminocarbonylation, amination, amidation, and cyanation, as well as its reaction with arynes. © 2012 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Liang Y.,Peking University | Jiao N.,Chinese Academy of Sciences
Angewandte Chemie - International Edition | Year: 2016

The unique regioselectivity and reactivity of cobalt(III) in the direct cyclization of N-nitrosoanilines with alkynes for the expedient synthesis of N-substituted indoles is demonstrated. In the presence of a cobalt(III) catalyst, high regioselectivity was observed when using unsymmetrical meta-substituted N-nitrosoanilines. Moreover, internal alkynes bearing electron-deficient groups, which are almost unreactive in the [Cp∗RhIII]-catalyzed system, display good reactivity in this transformation. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Xu X.,Chinese Academy of Sciences
BioEssays | Year: 2013

Many complex behaviors are genetically hardwired. Based on previous findings on genetic control of mating and other behaviors in invertebrate and mammalian systems, I suggest that genetic control of complex behaviors is modular: first, dedicated genes specify different behavioral patterns; secondly, separable genetic networks govern distinct behavioral components. I speculate that modular genetic encoding of complex behaviors may in part reflect modularity in brain development and function. © 2013 WILEY Periodicals, Inc.

Chen W.Q.,Chinese Academy of Sciences
Zhonghua yu fang yi xue za zhi [Chinese journal of preventive medicine] | Year: 2010

To analyze the mortality distribution characteristics and epidemiological trend of lung cancer in 2004 - 2005 in China. A total of 142 660 482 person years (72 970 241 person years in male, 69 690 241 person years in female) was covered in the Third National Retrospective Sampling Survey of Death Causes in China, 2004 - 2005. All death records of cancer of trachea, bronchus and lung were extracted. According to the different variations such as gender, urban or rural areas and three territory regions-Eastern, Central and Western China for lung cancer deaths, crude, age-adjusted, area-adjusted death rate, the constitute proportion to all cancer deaths, age-standardized death rate by Chinese standard population and by world standard population and rank of cancer-specific mortality were calculated. The statistic indexes of mortality were compared with that of previous retrospective death surveys in 1973 - 1975 and 1990 - 1992. In the National Death Survey 2004 - 2005, there were 43 993 deaths caused by lung cancer with crude death rate of 30.84/100 000, age-standardized death rate by Chinese standard population of 20.24/100 000 and 27.62/100 000 by world standard population, accounted for 22.70% of total cancer deaths (193 841 cases). There were a total of 30 167 cancer deaths in male with crude death rate of 41.34/100 000 and 13 826 in female with crude death rate of 19.84/100 000. Lung cancer mortality was increased with age. In urban areas, the lung cancer was ranked the first cancer death causes with crude death rate of 40.98/100 000 (19 628/47 899 806), accounted for 27.29% of all cancer deaths. While in rural areas, the lung cancer was the second cancer death following liver cancer with crude death rate of 25.71/100 000 (24 365/94 760 676), accounted for 19.99% of all cancer deaths (121 905 cases). There were different death rates by different location division. Lung cancer crude death rate in east was the highest with rate of 37.85/100 000 (19 893/52 556 694) and in west was the lowest with rate of 21.76/100 000(8774/40 322 563). Crude death rate of lung cancer increased by 75.83% compared with the second survey (crude death rate was 17.54/100 000) in 1990 - 1992, increased by 464.84% compared with the first survey (crude death rate was 5.46/100 000) in 1973 - 1975, showing a significant uptrend. Lung cancer is the most important cancer affecting the health of Chinese urban residents. The mortality has been increasing significantly.

You W.,Chinese Academy of Sciences
Zhen ci yan jiu = Acupuncture research / [Zhongguo yi xue ke xue yuan Yi xue qing bao yan jiu suo bian ji] | Year: 2010

To observe the effect of electroacupuncture (EA) on the expression of glucocorticoid (GC) mRNA and GC in the hippocampus, hypothalamus and pituitary in depression rats so as to study its mechanism underlying EA-resisting depression. Seventy SD rats were randomized into normal control, model, Fluoxetine (Flu), constraint-stress, EA, RU 486 (an antagonist of GC) and EA+ RU 486 groups (n = 10/group). Chronic depression model was established by lonely raising and chronic unpredictable mild stress for 21 days. EA (2 Hz, 0.6 mA) was applied to "Baihui" (GV 20) and "Yintang" (EX-HN 3) for 20 min, once daily for 21 days. Subcutaneous injection of RU 486 (20 mg/kg) was given to the rats from the 14th day on and con- tinuously for 7 days in order to block the negative feedback reflex of hypothalamus-pituitary-adrenal (HPA) axis. Cortisol (CORT) content of the adrenal gland tissue was detected by radioimmunassay. The expression of GC receptor (GR) mRNA in the hippocampus, hypothalamus and pituitary tissues was determined by real-time quantitative reverse transcription-polymerase chain reaction (RT-PCR). Compared with the normal control group, adrenal CORT content of model group was increased significantly (P < 0.05), and in comparison with model group, adrenal CORT level of EA group decreased evidently (P < 0.05). Comparison between the RU 486 and EA + RU 486 groups showed that the adrenal CORT content, and hippocampal GR mRNA expression level of the latter were remarkably lower than those of the former (P < 0.05). Compared with the normal control group, the expression level of GR mRNA of the hipppocampal and pituitary tissues in the model, constraint-stress, and RU 486 groups,and those of the hypothalamus in the constraint-stress and RU 486 groups were down-regulated significantly (P < 0.05). In comparison with the constraint-stress group, hippocampal, hypothalamic and pituitary GR mRNA expression level in the EA group were upregulated considerably (P < 0.05). No significant differences were found among model, Flu, constraint-stress, RU 486 and EA + RU 486 groups in the ardenal CORT contents, and hippocampal, hypothalamic and pituitary GR mRNA expression levels (P > 0.05). EA can effectively down-regulate adrenal CORT content and hippocampal GR mRNA expression and normalize the function of HPA axis negative feed reflex in the depression rats, which may contribute to its effect in relieving depression.

Fang Y.,Chinese Academy of Sciences
Renewable and Sustainable Energy Reviews | Year: 2011

Over the last years renewable energy sources have increased their share on electricity generation of China due to environmental and security of supply concerns. In this work author assesses the role of both the amount and share of renewable energy consumption in economic welfare using Cobb-Douglas type production functions. This assessment is carried out by multivariate OLS and SPSS software for China from 1978 to 2008. Results indicate that a 1% increase in renewable energy consumption (REC) increases real GDP by 0.120%, GDP per capita by 0.162%, per capita annual income of rural households by 0.444%, and per capita annual income of urban households by 0.368% respectively; the impact of renewable energy consumption share (SREC) on economic welfare is insignificant, and an increasing share of REC negatively affects economic welfare growth to a certain extent. In this paper, the cost, structural demand, accounting mechanism and policy reasons of renewable energy development are interpreted. Marginal effects analysis show that the shape of sound and robust renewable energy institutions and policies would matter for increasing the standards of economic welfare in the context of speeding up renewable energy development and increasing share of renewable energy consumption, especially the goal-oriented policy refinement should be addressed efficiently in improvement households income while increasing share of renewable energy consumption. © 2011 Elsevier Ltd. All rights reserved.

Yu P.,Chinese Academy of Sciences
Zhongguo shi yan xue ye xue za zhi / Zhongguo bing li sheng li xue hui = Journal of experimental hematology / Chinese Association of Pathophysiology | Year: 2012

This study was aimed to investigate the expression of c-MPL in acute myeloid leukemia (AML) and the correlation of the c-MPL expression with CD34 and CD38, so as to define the expression of c-MPL in leukemic stem cells. The expression levels of CD34, CD38 and c-MPL were detected by flow cytometry in bone marrow cells from 29 newly diagnosed AML patients. The relationship of c-MPL positive cell ratio with clinical parameters and correlation of c-MPL with CD34 and CD38 expression in AML patients were analyzed. The results showed that expression level of c-MPL in AML patients was significantly higher than that of normal controls (P < 0.05), and the expression level of c-MPL did not correlate with age, sex, white blood cell count, AML1-ETO fusion gene and remission after chemotherapy, but the expression of c-MPL in M2 and M5 patients was higher than that of normal control (P < 0.05). Expression of c-MPL in CD34 positive AML patients was obviously higher than that in CD34 negative AML patients (P < 0.01). c-MPL was significantly higher expressed in CD34(+) cells than that in CD34(-) cells (P < 0.001), while c-MPL expression was not significantly different between CD34(+)CD38(-) and CD34(+)CD38(-) cell groups. Positive correlation between c-MPL and CD34 expression was observed (r = 0.380, P = 0.042). It is concluded that expression of c-MPL is higher in AML patients, and positively correlates with the expression level of CD34. The c-MPL expresses in leukemic stem cells.

Tan S.,Georgia Institute of Technology | Tan S.,Chinese Academy of Sciences
Physical Review Letters | Year: 2012

Some novel two-body effects analogous to the well-known three-body Efimov effect are predicted. In the systems considered, particle A is constrained on a truncated or bent one-dimensional line or two-dimensional plane, or on one side of a flat mirror in three dimensions (3D). The constraining potential is fine-tuned such that particle A's ground state wave function is a constant in the region in which it is constrained. Particle B moves in 3D and interacts with particle A, resonantly. An infinite sequence of giant two-body bound states are found in each case. © 2012 American Physical Society.

Jiang Y.,Chinese Academy of Sciences | Hsu W.,Wuhan University
Meteoritics and Planetary Science | Year: 2012

Abstract-: Grove Mountains (GRV) 020090 is a "lherzolitic" shergottite found in the Grove Mountains, Antarctica. It exhibits two distinct textures: poikilitic and nonpoikilitic. In poikilitic areas, large pyroxene oikocrysts enclose subhedral olivine and chromite chadacrysts. Pyroxene oikocrysts are zoned from pigeonite cores to augite rims. In nonpoikilitic areas, olivine, pyroxene, and interstitial maskelynite occur as major phases, and minor phases include chromite and merrillite. Compared with typical "lherzolitic" shergottites, GRV 020090 contains a distinctly higher abundance of maskelynite (19 vol%). Olivine and pyroxene are more ferroan (Fa 28-40, En 57-72Fs 24-31Wo 4-14 and En 46-53Fs 17-21Wo 26-35), and maskelynite is more alkali-rich (Ab 43-65Or 2-7). The major phases, whole-rock (estimated) and fusion crust of GRV 020090, are relatively enriched in light rare earth elements (LREE), similar to those of the geochemically enriched basaltic shergottites, but distinct from those of LREE-depleted "lherzolitic" shergottites. Combined with a high oxygen fugacity of log fO 2=QFM-1.41±0.04 (relative to the quartz-fayalite-magnetite buffer), it is clear that GRV 020090 sampled from an oxidized and enriched mantle reservoir similar to those of other enriched shergottites. The calculated REE abundances and patterns of the melts in equilibrium with the cores of major phases are parallel to but higher than that of the whole rock, suggesting that GRV 020090 originated from a single parent magma and experienced progressive fractional crystallization in a closed system. The crystallization age recorded by baddeleyite is 192±10 (2σ) Ma, consistent with the young internal isochron ages of enriched shergottites. Baddeleyite dating results further demonstrated that the young ages, rather than ancient ages (>4Ga), appear to represent the crystallization of Martian surface lava flow. GRV 020090 shares many similarities with Roberts Massif (RBT) 04261/2, the first enriched "lherzolitic" shergottite. Detailed comparisons suggest that these two rocks are petrologically and geochemically closely related, and probably launch paired. © The Meteoritical Society, 2012.

Liu B.,University of Chinese Academy of Sciences | Li J.-L.,University of Chinese Academy of Sciences | Li X.,University of Chinese Academy of Sciences | Qiao C.-F.,University of Chinese Academy of Sciences | Qiao C.-F.,Chinese Academy of Sciences
Physical Review Letters | Year: 2012

We propose a practical entanglement classification scheme for general multipartite pure states in arbitrary dimensions under local unitary equivalence by exploiting the high order singular value decomposition technique and local symmetries of the states. By virtue of this scheme, the method of determining the local unitary equivalence of n-qubit states proposed by Kraus is extended to the case for arbitrary dimensional multipartite states. © 2012 American Physical Society.

Zhang Q.S.,CAS National Astronomical Observatories | Zhang Q.S.,Chinese Academy of Sciences | Zhang Q.S.,University of Chinese Academy of Sciences
Astrophysical Journal, Supplement Series | Year: 2013

Convective overshoot mixing plays an important role in stellar structure and evolution. However, overshoot mixing is also a long-standing problem; it is one of the most uncertain factors in stellar physics. As is well known, convective overshoot mixing is determined by the radial turbulent flux of the chemical component. In this paper, a local model of the radial turbulent flux of the chemical component is established based on hydrodynamic equations and some model assumptions and is tested in stellar models. The main conclusions are as follows. (1) The local model shows that convective overshoot mixing could be regarded as a diffusion process and the diffusion coefficient for different chemical elements is the same. However, if the non-local terms i.e., the gradient of the third-order moments, are taken into account, the diffusion coefficient for each chemical element should in general be different. (2) The diffusion coefficient of convective/overshoot mixing shows different behaviors in the convection zone and in the overshoot region because the characteristic length scale of the mixing is large in the convection zone and small in the overshoot region. Overshoot mixing should be regarded as a weak mixing process. (3) The diffusion coefficient of mixing is tested in stellar models, and it is found that a single choice of our central mixing parameter leads to consistent results for a solar convective envelope model as well as for core convection models of stars with masses from 2 M to 10 M. © 2013. The American Astronomical Society. All rights reserved.

Guo J.H.,CAS National Astronomical Observatories | Guo J.H.,Chinese Academy of Sciences
Astrophysical Journal | Year: 2013

In Paper I, we presented a one-dimensional hydrodynamic model for the winds of close-in exoplanets. However, close-in exoplanets are tidally locked and irradiated only on the day sides by their host stars. This requires two-dimensional hydrodynamic models with self-consistent radiative transfer calculations. In this paper, for the tidal-locking (two-dimensional radiative transfer) and non-tidal-locking cases (one-dimensional radiative transfer), we constructed a multi-fluid two-dimensional hydrodynamic model with detailed radiative transfer to depict the escape of particles. We found that the tidal forces (the sum of tidal gravity of the star and centrifugal force due to the planetary rotation) supply significant accelerations and result in anisotropic winds. An important effect of the tidal forces is that it severely depresses the outflow of particles near the polar regions where the density and the radial velocity are a factor of a few (ten) smaller than those of the low-latitude regions. As a consequence, most particles escape the surface of the planet from the regions of low latitude. Comparing the tidal-locking and non-tidal-locking cases, we found that their optical depths are very different so that the flows also emerge with a different pattern. In the case of non-tidal locking, the radial velocities at the base of the wind are higher than the meridional velocities. However, in the case of tidal locking, the meridional velocities dominate the flow at the base of the wind, and they can effectively transfer mass and energy from the day sides to the night sides. Further, we also found that the differences of the winds show a middle extent at large radii. This means that the structure of the wind at the base can be changed by the two-dimensional radiative transfer due to large optical depths, but the extent is reduced with an increase in radius. Because the escape is depressed in the polar regions, the mass-loss rate predicted by the non-tidal-locking model, in the order of magnitude of 1010 g s-1, is a factor of two lower than that predicted by the one-dimensional hydrodynamic model. The results of tidal locking show that the mass-loss rate is decreased an order of magnitude, only 4.3 × 109 g s-1, due to large optical depths on the night side. We also found that the distributions of hydrogen atoms show clear variations from the day side to the night side, thus the origin of the excess absorption in Lyα should be reexamined using multi-dimensional hydrodynamic models. © 2013. The American Astronomical Society. All rights reserved.

Guan C.-Z.,CAS Institute of Chemistry | Guan C.-Z.,Chinese Academy of Sciences | Wang D.,CAS Institute of Chemistry | Wan L.-J.,CAS Institute of Chemistry
Chemical Communications | Year: 2012

The construction of well-ordered 2D covalent networks via the dehydration of di-borate aromatic molecules was successfully realized through introducing a small amount of water into a closed reaction system to regulate the chemical equilibrium. © 2012 The Royal Society of Chemistry.

Gu M.,Chinese Academy of Sciences
Astrophysical Journal | Year: 2013

We have assembled a large sample of 5996 quasars at 2.0 ≤ z ≤ 2.4 (high-z) or 0.7 ≤ z ≤ 1.1 (low-z) from the Sloan Digital Sky Survey (SDSS) ninth and seventh data release and quasar catalogs. The spectral energy distributions of quasars were constructed by collecting WISE, UKIDSS, and GALEX photometric data in addition to SDSS data, from which the IR luminosity at 1-7 μm and bolometric luminosity at 1100 1 μm were calculated. A red tail is clearly seen in the distribution of the spectral index over 1100 1 μm for both the high-z and low-z sources; this tail is likely due to red or reddened quasars. The covering factor (CF) of the dusty torus is estimated as the ratio of the IR luminosity to the bolometric luminosity. We find significant anti-correlations between the CF and the bolometric luminosity, in both the high-z and low-z quasars; however, these two groups follow different tracks. At overlapping bolometric luminosities, the CF of high-z quasars is systematically larger than those of low-z quasars, implying an evolution of the CF with redshift. © 2013. The American Astronomical Society. All rights reserved.

Zuo F.,CAS Institute of High Energy Physics | Zuo F.,Chinese Academy of Sciences | Zuo F.,CAS Institute of Theoretical Physics
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2010

I propose to change the sign of the dilaton in the infrared (IR) soft-wall anti-de Sitter/QCD model, in order to implement confinement. The deformed model exhibits interesting properties, especially in describing chiral symmetry breaking. The expectation value of the scalar field X, which determines the quark mass and condensate, approaches a constant in the IR limit, rather than blows up in the original model. In contrast to the estimate in, this kind of solution will not lead to chiral symmetry restoration for highly-excited states due to the property of the harmonic-oscillator equation. Instead, it will guarantee the Regge behavior of the axial meson spectrum and also the pseudoscalar mesons. The value of the condensate can be fixed by requiring that the pion be massless in the chiral limit, but only under some approximation in the present model. We also find that, by relaxing the IR boundary conditions, the unphysical massless state in the vector channel can be eliminated. © 2010 The American Physical Society.

Li Z.,Peking University | Li Z.,Chinese Academy of Sciences
Astrophysical Journal Letters | Year: 2013

If gamma-ray bursts (GRBs) produce high-energy cosmic rays, neutrinos are expected to be generated in GRBs via photo-pion productions. However, we stress that the same process also generates electromagnetic (EM) emission induced by the secondary electrons and photons, and that the EM emission is expected to be correlated with neutrino flux. Using Fermi/Large Area Telescope results on gamma-ray flux from GRBs, the GRB neutrino emission is limited to be <20 GeV m-2 per GRB event on average, which is independent of the unknown GRB proton luminosity. This neutrino limit suggests that IceCube, operating at full scale, requires stacking of more than 130 GRBs in order to detect one GRB muon neutrino. © 2013. The American Astronomical Society. All rights reserved..

Tian Y.,University of Chinese Academy of Sciences | Wu X.-N.,CAS Academy of Mathematics and Systems Science | Wu X.-N.,Chinese Academy of Sciences
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2010

A gravitational potential in the relativistic case is introduced as an alternative to Wald's potential used by Verlinde, which reproduces the familiar entropy/area relation S=A/4 (in the natural units) when Verlinde's idea is applied to the black hole case. Upon using the equipartition rule, the correct form of the Komar mass (energy) can also be obtained, which leads to the Einstein equations. It is explicitly shown that our entropy formula agrees with Verlinde's entropy variation formula in spherical cases. The stationary space-times, especially the Kerr-Newman black hole, are then discussed, where it is shown that the equipartition rule involves the reduced mass, instead of the Arnowitt-Deser-Misner mass, on the horizon of the black hole. © 2010 The American Physical Society.

Lin H.,CAS Fujian Institute of Research on the Structure of Matter | Li L.,CAS Fujian Institute of Research on the Structure of Matter | Zhao M.,CAS Fujian Institute of Research on the Structure of Matter | Huang X.,Chinese Academy of Sciences | And 3 more authors.
Journal of the American Chemical Society | Year: 2012

The brookite phase of TiO 2 is hardly prepared and rarely studied in comparison with the common anatase and rutile phases. In addition, there exist immense controversies over the cognition of the light-induced liveliness of this material. Here, a novel, low-basicity solution chemistry method was first used to prepare homogeneous high-quality brookite TiO 2 single-crystalline nanosheets surrounded with four {210}, two {101}, and two {201} facets. These nanosheets exhibited outstanding activity toward the catalytic degradation of organic contaminants superior even to that of Degussa P25, due to the exposure of high-energy facets and the effective suppression of recombination rates of photogenerated electrons and holes by these facets as the oxidative and reductive sites. In contrast, irregularly faceted phase-pure brookite nanoflowers and nanospindles were inactive in catalytic reactions. These results demonstrate that the photocatalytic activity of brookite TiO 2 is highly dependent upon its exposed facets, which offers a strategy for tuning the catalysts from inert to highly active through tailoring of the morphology and surface structure. © 2012 American Chemical Society.

Xie J.,Chinese Academy of Sciences
Computers and Geosciences | Year: 2012

This paper introduces a parallel contour line interpolation algorithm from Digital Elevation Model (DEM). Contour generation from DEM is the basic task of the computer-aided mapping and one of the most important applications of DEM. With the increasing of DEM resolution, the Digital Terrain Analysis (DTA) has become one of the computing-intensive tasks in GIS. Many studies have been done on the implementation of parallel DTA algorithms based on different parallel hardware and software. In this paper, we use the open source GIS toolkit to implement a parallel contour generation algorithm. The Message Passing Interface (MPI) standard is used for the parallel algorithm programming. A slackly LAN (Local Area Network)-connected windows cluster is setup to implement and test the parallel contour line generation algorithm. The performance optimization method for the parallel algorithm is specifically discussed, including data redundancy method, group communication, packaging collection of results, and memory optimization method for results merging. The experimental results show the capacity and potential to implement the parallel GIS algorithms based on open source GIS toolkit in the LAN-connected PC environment. © 2012 Elsevier Ltd.

Dai M.,Chinese Academy of Sciences
Zhonghua liu xing bing xue za zhi = Zhonghua liuxingbingxue zazhi | Year: 2012

To estimate the incidence and mortality rates of cancers in China in 2008. Data from 36 cancer registry sites in China and from the Third National Death Survey in China (2004 - 2005) were used to estimate the incidence and mortality of cancer in China in 2008 by using mathematical models. Prediction on cancer incidence and mortality in the next 20 years was carried out. According to the age-standardized incidence rates, the top cancer sites were lung, stomach, liver, breast, oesophageal, colorectal, corpus uterine, cervical, leukemia and brain tumor. According to the age-standardized mortality rates, the top cancers in China were lung cancer, liver cancer, stomach cancer, oesophageal cancer, colorectal cancer, breast cancer, cervical cancer, leukemia, brain tumor and corpus uterine cancer. Cancer happened more frequently among people older than 40 years, particularly among males. Data related to prediction showed that the incidence and mortality of cancer in China would gradually increase in the next 20 years. Both incidence and mortality of cancers in China had been increasing, with the most common cancers appeared to be lung, breast and digestive tract cancers, in China. People older than 40 years should be under specific care to receive prevention and care on cancer, with males in particular.

To investigate the efficacy of adenosine triphosphate (ATP)-tumor chemosensitivity assay (TCA) directed chemotherapy in patients with recurrent epithelial ovarian cancer. From August 2010 to June 2012, recurrent epithelial ovarian cancer patients were prospectively enrollmented in Cancer Hospital, Peking Union Medical College,Chinese Academy of Medical Sciences.The entry criteria are as follows: (1) Histologically proven to be epithelial ovarian cancer. (2) Patients of recurrent ovarian cancer with bidimensionally measurable tumor, or ascitic or pleural fluid for testing. (3) Karnofsky performance status > 60. (4) A life expectancy of at least more than 6 months.According to patients desires, they were assigned into two groups: assay-directed therapy group and physician's-choice therapy group, patients' clinical and pathological characteristics, response rate to chemotherapy and progression-free survival (PFS) were compared between two groups. A total of 113 patients with recurrent epithelial ovarian cancer were prospectively enrollmented to assay-directed chemotherapy (n = 56) or physician's-choice chemotherapy (n = 57).There was no difference in median age,types of recurrence, surgical-pathological stage, pathological type, tumor grade, times of recurrence, residual disease at secondary cytoreductive surgery between assay-directed group and physician's-choice group. The overall response rate (ORR) and median PFS in the ATP-TCA group was 66% (37/56) and 7 months, while the ORR in the control group was 46% (26/57, P = 0.037), the median PFS was 4 months (P = 0.040). For platinum-resistant patients, the ORR between ATP-TCA directed chemotherapy 59% (16/27) and control group 25% (7/28) were significantly different (P = 0.010), and the median PFS between two groups were also significantly different (5 months and 2 months, respectively, P = 0.003). ATP-TCA directed chemotherapy could improve ORR and PFS in patients with recurrent epithelial ovarian cancer, especially in platinum-resistant patients.

Li C.,Nanjing University | Firoz K.A.,Chinese Academy of Sciences | Sun L.P.,Nanjing University | Miroshnichenko L.I.,Moscow State University
Astrophysical Journal | Year: 2013

High-energy particles were recorded by near-Earth spacecraft and ground-based neutron monitors (NMs) on 2012 May 17. This event was the first ground level enhancement (GLE) of solar cycle 24. In this study, we try to identify the acceleration source(s) of solar energetic particles by combining in situ particle measurements from the WIND/3DP, GOES 13, and solar cosmic rays registered by several NMs, as well as remote-sensing solar observations from SDO/AIA, SOHO/LASCO, and RHESSI. We derive the interplanetary magnetic field (IMF) path length (1.25 ± 0.05 AU) and solar particle release time (01:29 ± 00:01 UT) of the first arriving electrons by using their velocity dispersion and taking into account contamination effects. We found that the electron impulsive injection phase, indicated by the dramatic change in the spectral index, is consistent with flare non-thermal emission and type III radio bursts. Based on the potential field source surface concept, modeling of the open-field lines rooted in the active region has been performed to provide escape channels for flare-accelerated electrons. Meanwhile, relativistic protons are found to be released 10 minutes later than the electrons, assuming their scatter-free travel along the same IMF path length. Combining multi-wavelength imaging data of the prominence eruption and coronal mass ejection (CME), we obtain evidence that GLE protons, with an estimated kinetic energy of 1.12 GeV, are probably accelerated by the CME-driven shock when it travels to 3.07 solar radii. The time-of-maximum spectrum of protons is typical for shock wave acceleration. © 2013. The American Astronomical Society. All rights reserved.

Wu Q.,Huazhong University of Science and Technology | Cao X.,Chinese Academy of Sciences | Ho L.C.,Carnegie Institution for Science | Wang D.-X.,Huazhong University of Science and Technology
Astrophysical Journal | Year: 2013

Recent observations suggest that in black hole X-ray binaries jet/outflow formation is related to the hot plasma in the vicinity of the black hole, either in the form of an advection-dominated accretion flow at low accretion rates or in a disk corona at high accretion rates. We test the viability of this scenario for supermassive black holes using two samples of active galactic nuclei distinguished by the presence (radio-strong) and absence (radio-weak) of well-collimated, relativistic jets. Each is centered on a narrow range of black hole mass but spans a very broad range of Eddington ratios, effectively simulating in a statistical manner the behavior of a single black hole evolving across a wide spread in accretion states. Unlike the relationship between the radio and optical luminosity, which shows an abrupt break between high- and low-luminosity sources at an Eddington ratio of 1%, the radio emission - a measure of the jet power - varies continuously with the hard X-ray (2-10 keV) luminosity, roughly as . This relation, which holds for both radio-weak and radio-strong active galaxies, is similar to the one seen in X-ray binaries. Jet/outflow formation appears to be closely linked to the conditions that give rise to the hot, optically thin coronal emission associated with accretion flows, both in the regime of low and high accretion rates. © 2013. The American Astronomical Society. All rights reserved..

Melia F.,Chinese Academy of Sciences | Melia F.,University of Arizona
Astrophysical Journal | Year: 2013

One cannot understand the early appearance of 109 M ⊙ supermassive black holes without invoking anomalously high accretion rates or the creation of exotically massive seeds, neither of which is seen in the local universe. Recent observations have compounded this problem by demonstrating that most, if not all, of the high-z quasars appear to be accreting at the Eddington limit. In the context of ΛCDM, the only viable alternative now appears to be the assemblage of supermassive black holes via mergers, as long as the seeds started forming at redshifts >40, but ceased being created by z ∼ 20-30. In this paper, we show that, whereas the high-z quasars may be difficult to explain within the framework of the standard model, they can instead be interpreted much more sensibly in the context of the R h = ct universe. In this cosmology, 5-20 M⊙ seeds produced after the onset of re-ionization (at z ≲ 15) could have easily grown to M ≳ 109 M⊙ by z ≳ 6, merely by accreting at the standard Eddington rate. © 2013. The American Astronomical Society. All rights reserved.

Jia Y.,CAS Institute of High Energy Physics | Jia Y.,Chinese Academy of Sciences | Jia Y.,CAS Institute of Theoretical Physics
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2010

We study the first-order relativistic correction to the associated production of J/ψ with light hadrons at B factory experiments at √s=10.58GeV, in the context of nonrelativistic QCD (NRQCD) factorization. We employ a strategy for NRQCD expansion that slightly deviates from the orthodox doctrine, in that the matching coefficients are not truly of a "short-distance" nature, but explicitly depend upon physical kinematic variables rather than partonic ones. Our matching method, with validity guaranteed by the Gremm-Kapustin relation, is particularly suited for the inclusive quarkonium production and decay processes with involved kinematics, exemplified by the process e+e-→J/ψ+gg considered in this work. Despite some intrinsic ambiguity affiliated with the order-v2 NRQCD matrix element, if we choose its value as what has been extracted from a recent Cornell-potential-model-based analysis, including the relative order-v2 effect is found to increase the lowest-order prediction for the integrated J/ψ cross section by about 30%, and exert a modest impact on J/ψ energy, angular and polarization distributions except near the very upper end of the J/ψ energy. The order-v2 contribution to the energy spectrum becomes logarithmically divergent at the maximum of J/ψ energy. A consistent analysis may require that these large end-point logarithms be resummed to all orders in αs. © 2010 The American Physical Society.

Zhang X.-G.,Chinese Academy of Sciences | Zhang X.-G.,Chinese Center for Antarctic Astronomy
Monthly Notices of the Royal Astronomical Society: Letters | Year: 2013

In this Letter, under the widely accepted theoretical accretion disc model for the double-peaked emitter 3C 390.3, the extended disc-like broad-line region can be well split into 10 rings, and then the time lags between the lines from the rings and the continuum emission are estimated, based on the observed spectra around 1995. We can find one very strong correlation between the determined time lags (in units of light-day) and the flux-weighted radii (in units of RG) of the rings, which is well consistent with the expected results through the theoretical accretion disc model. Moreover, through the strong correlation, the black hole masses of 3C 390.3 are independently estimated as 109M⊙, the same as the reported black hole masses in the literature. The consistencies provide further evidence to strongly support the accretion disc origination of the double-peaked broad Balmer lines of 3C 390.3. © 2013 The Author Published by Oxford University Press on behalf of the Royal Astronomical Society.

Tong H.,Chinese Academy of Sciences | Xu R.-X.,Peking University
Research in Astronomy and Astrophysics | Year: 2013

The different timing results of the magnetar Swift J1822.3-1606 are analyzed and understood theoretically. It is noted that different timing solutions are caused not only by timing noise, but also because the period derivative is decreasing after the outburst. Both the decreasing period derivative and the large timing noise may originate from wind braking associated with the magnetar. Future timing of Swift J1822.3-1606 will help clarify whether or not its period derivative is decreasing with time. © 2013 National Astronomical Observatories of Chinese Academy of Sciences and IOP Publishing Ltd.

Deng X.,Chinese Academy of Sciences
Science China: Physics, Mechanics and Astronomy | Year: 2011

Searching for an intermediate-range force has been considerable interests in gravity experiments. In this paper, aiming at a scalartensor theory with an intermediate-range force, we have derived the metric and equations of motion (EOMs) in the first post-Newtonian (1PN) approximation for general matter without specific equation of state and N point masses firstly. Subsequently, the secular periastron precession $$\dot \omega$$ of binary pulsars in harmonic coordinates is given. After that, $$\dot \omega$$ of four binary pulsars data (PSR B1913+16, PSR B1534+12, PSR J0737-3039 and PSR B2127+11C) have been used to constrain the intermediate-range force, namely, the parameters α and λ. α and λ respectively represent the strength of the intermediate-range force coupling and its length scale. The limits from four binary pulsars data are respectively λ = (4.95±0.02)×10 8 m and α = (2.30±0.01)×10-8 if β = 1, where β is a parameter like standard parametrized post-Newtonian parameter β PPN. When three degrees of freedom (α, λ and β, $$\bar \beta \equiv \beta - 1$$ ) in 1σ confidence level are considered, it yields α = (4.21 ± 0.01) × 10-4, λ = (4.51 ± 0.01) × 107 m and $$\bar \beta = ( - 3.30 \pm 0.01) \times 10 - 3$$ . Through our research on the scalar-tensor theory with the intermediate-range force, it shows that the parameter α is directly related to the parameter γ (α = (1 - γ)/(1 + γ)). Thus, this presents the constraints on 1 - γ by binary pulsars which is about 10-4 for three degrees of freedom. © 2011 Science China Press and Springer-Verlag Berlin Heidelberg.

Huang Q.,CNRS Paris Institute of Global Physics | Huang Q.,Chinese Academy of Sciences | Wieczorek M.A.,CNRS Paris Institute of Global Physics
Journal of Geophysical Research E: Planets | Year: 2012

Newly obtained gravity and topography data of the Moon, combined with a lithospheric flexure model that considers both surface and subsurface loading, are used to place constraints on the density of the upper crust from a localized spectral admittance analysis. Subsurface loads are found to be relatively unimportant in the highlands, and when subsurface loads are neglected, the best fitting bulk densities for a number of highland regions are found to vary from 2590 to 2870 kg m -3, with a mean value of 2691 kg m -3. Crustal rock densities estimated from geochemical considerations and global iron and titanium abundances imply somewhat greater densities, which we interpret as porosity affecting the gravity-derived bulk density estimates. The average porosity in the upper few kilometers of crust is calculated to be about 7.7%, which is consistent with porosity estimates of impact-fractured meteorites and terrestrial impact craters. Copyright 2012 by the American Geophysical Union.

Qin B.,Chinese Academy of Sciences
Plant Physiology and Biochemistry | Year: 2013

The Rad6 gene of Saccharomyces cerevisiae encodes an ubiquitin-conjugating enzyme (E2) which is required for DNA repair, damage-induced mutagenesis, sporulation, etc. In this study, one Rad6 homolog, designated HbRad6, was cloned in rubber tree (Hevea brasiliensis). The putative protein sequence of HbRad6 contains 152 amino acids, a conserved UBC domain, and a conserved active-site cysteine in the UBC domain, which is required for E2 enzymes catalytic activity. HbRad6 shared high similarity with Rad6 from other species. It shared the highest similarity with rice OsRad6 and Arabidopsis thaliana AtUBC2 with 96.05% identical residues, and 63.16% sequence identity with yeast Rad6 (excluding the acidic tail). Comparing expression among different Hevea tissues demonstrated that HbRad6 was ubiquitously expressed in all tissues, but it revealed a preferential expression in the latex. Furthermore, HbRad6 expression was markedly induced by DNA-damaging agent H2O2, the latex stimulator ethephon (ET), and methyl jasmonate (MeJA), while NaCl and wounding treatments had relatively minor effect upon its expression. Genetic complementation experiment revealed that HbRad6 had minor effects on the complementation of the UV sensitivity of yeast rad6 null mutant, indicating that the Hevea Rad6 protein may partially suppress the UV sensitivity of the yeast rad6 mutant. These results suggested that HbRad6 was a multifunction gene involved in DNA damage repair, hormones and stress responses in rubber tree. © 2013 Elsevier Masson SAS.

Lemoine M.,CNRS Paris Institute of Astrophysics | Li Z.,Peking University | Li Z.,Chinese Academy of Sciences | Wang X.-Y.,Nanjing University
Monthly Notices of the Royal Astronomical Society | Year: 2013

The origin of magnetic fields that permeate the blast waves of gamma-ray bursts (GRBs) is a long-standing problem. The present paper argues that in four GRBs revealing extended emission at >100MeV, with follow-up in the radio, optical and X-ray domains at later times, this magnetization can be described as the partial decay of the micro-turbulence that is generated in the shock precursor. Assuming that the bulk of the extended emission >100 MeV can be interpreted as synchrotron emission of shock-accelerated electrons, wemodel themulti-wavelength light curves of GRB 090902B, GRB 090323, GRB 090328 and GRB 110731A, using a simplified then a full synchrotron calculation with power-law-decaying micro-turbulence εα tαt (t denotes the time since injection through the shock, in the comoving blast frame). We find that these models point to a consistent value of the decay exponent -0.5{less than or approximate} αt {less than or approximate} -0.4.

Chen Y.,Xinjiang Institute of Ecology and Geography | Ye Z.,Xinjiang Institute of Ecology and Geography | Shen Y.,Chinese Academy of Sciences
Quaternary International | Year: 2011

Desiccation of the Tarim River is increasingly severe, as shown by the increases in length affected and time of desiccation. If the tendency is not constrained, the difficulty in water transfer to the lower reach of the Tarim River will be greatly increased, and the ecological security in the river basin and the downstream "Green Corridor" protection will be severely impacted. This paper analyses the desiccation tendency and hydrological regime of the Tarim River, discusses the causes of this condition, the point of zero flow movement, and the influence on the ecological security in the Tarim River basin that may be caused by the further development of desiccation. The relationship between soil and water resource management and hydrological regime change in the Tarim River basin and river desiccation is analyzed. The main causes of the river desiccation were the increase in irrigated area of the headstream section in the upstream region, the rise in water consumption in the upper and middle reaches, and the construction of reservoirs in the mountain areas. Accordingly, possible countermeasures and ideas for mitigating the desiccation tendency are suggested, so as to provide decision-making references for water resource management and sustainable and healthy social, ecological and economic development in the Tarim River basin. © 2011 Elsevier Ltd and INQUA.

He J.,Peking University | He J.,Chinese Academy of Sciences | Tu C.,Peking University | Marsch E.,Max Planck Institute for Solar System Research | Yao S.,China University of Geosciences
Astrophysical Journal Letters | Year: 2012

To determine thewavemodes prevailing in solar wind turbulence at kinetic scales,we study themagnetic polarization of small-scale fluctuations in the plane perpendicular to the data sampling direction (namely, the solar wind flow direction, VSW) and analyze its orientation with respect to the local background magnetic field B0, local. As an example, we take only measurements made in an outward magnetic sector. When B0, local is quasi-perpendicular to VSW, we find that the small-scale magnetic-field fluctuations, which have periods from about 1 to 3 s and are extracted from a wavelet decomposition of the original time series, show a polarization ellipse with right-handed orientation. This is consistent with a positive reduced magnetic helicity, as previously reported. Moreover, for the first time we find that the major axis of the ellipse is perpendicular to B 0, local, a property that is characteristic of an oblique Alfv́en wave rather than oblique whistler wave. For an oblique whistler wave, the major axis of the magnetic ellipse is expected to be aligned with B0, local, thus indicating significant magnetic compressibility, and the polarization turns from right to left handedness as the wave propagation angle (.kB) increases toward 90.. Therefore, we conclude that the observation of a right-handed polarization ellipse with orientation perpendicular to B 0, local seems to indicate that oblique Alfv́en/ion-cyclotron waves rather than oblique fast-mode/whistler waves dominate in the "dissipation" range near the break of solar wind turbulence spectra occurring around the proton inertial length. © 2012. The American Astronomical Society. All rights reserved.

Li G.,Qufu Normal University | Zhao Q.,CAS Institute of High Energy Physics | Zhao Q.,Chinese Academy of Sciences
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2011

With the new measurements of J/ψ and ψ′→γη c(γηc′) from the CLEO and BES-III collaboration, we reinvestigate the intermediate meson loop (IML) contributions to these radiative decays in association with the quark model M1 transitions in an effective Lagrangian approach. It shows that the "unquenched" effects due to the intermediate hadron loops can be better quantified by the new data for J/ψ→γηc. Although the IML contributions are relatively small in J/ψ→γηc, they play a crucial role in ψ′→γηc(γηc′). A prediction for the IML contributions to ψ(3770) →γηc(γηc′) is made. Such unquenched effects allow us to reach a coherent description of those three radiative transitions, and gain some insights into the underlying dynamics. © 2011 American Physical Society.

Zhang P.,Chinese Academy of Sciences
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2011

We derive the exact analytical solution of the linear structure growth rate in ΛCDM cosmology with flat or curved geometry, under the Newtonian gauge. Unlike the well known solution under the Newtonian limit, our solution takes all general relativistic corrections into account and is hence valid at both the sub- and superhorizon scales. With this exact solution, we evaluate cosmological impacts induced by these relativistic corrections. (1) General relativistic corrections alter the density growth from z=100 to z=0 by 10% at k=0.01h/Mpc and the impact becomes stronger toward larger scales. We caution the readers that the overdensity is not gauge invariant and the above statement is restrained to the Newtonian gauge. (2) Relativistic corrections introduce a k -2 scale dependence in the density fluctuation. It mimics a primordial non-Gaussianity of the local type with fNLlocal∼1. This systematical error may become non-negligible for future all sky deep galaxy surveys. (3) Cosmological simulations with box size greater than 1 Gpc are also affected by these relativistic corrections. We provide a postprocessing recipe to correct for these effects. (4) These relativistic corrections affect the redshift distortion. However, at redshifts and scales relevant to redshift distortion measurements, such effect is negligible. © 2011 American Physical Society.

Zhai M.G.,Chinese Academy of Sciences | Zhai M.G.,CAS Institute of Geology and Geophysics
Science China Earth Sciences | Year: 2013

The main old lands in China include the North China Block (NCB), South China Block (SCB) and Tarim Block (TRB), all of which have individual tectonic evolving histories. The NCB experienced complex geological evolution since the early Precambrian onwards, and carries important records from the old continental nuclei, giant crustal growth episode and cratonization (stabilitization), then to the Paleoproterozoic rifting-subduction-accretion-collision with imprints of the Great Oxygen Event (GOE), and to the Late Paleoproterozoic-Neoproterozoic multi-stage rifting representing North China platform tectonic features. The TRB has two-layer basement of the Early Precambrian metamorphic complexes and Neoproterozoic sedimentary sequences. Three till sheets have been reported. The SCB consists of the Yangtze Block (YZB) and Cathaysia Block (CTB) that were cohered in the Neoproterozoic. The YZB recorded tectonic processes of the Early Precambrian crustal growth, 1.0-0.9 Ga and 0.8-0.6 Ga metamorphic-magmatic events, and two Neoproterozoic glaciations. The CTB consists of ca. 1.8 Ga, 1.0 to 0.9 Ga and ca. 0.8 Ga granitic gneisses and metamorphic rocks, indicating there was a vast Precambrian basement. The Neoproterozoic sedimentary rocks overlie partly on the basement. That the YZB and CTB have a Neoproterozoic uniform cover layer illustrates the SCB should form, at least, during 1.0-0.9 Ga, corresponding to the Rodinia Supercontinent. The Central Chinese Orogenic System with high-ultra-high-pressure metamorphic rocks supports a suggestion that the above-mentioned three old lands were collided to assemble a unified Chinese Continent during the Pangea orogenic period. © 2013 Science China Press and Springer-Verlag Berlin Heidelberg.