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Search Results: 1 - 10 of 46052 matches for " HANG Hai-Feng "
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Molecular Dynamics Simulation of Phosphorylated KID Post-Translational Modification
Hai-Feng Chen
PLOS ONE , 2009, DOI: 10.1371/journal.pone.0006516
Abstract: Background Kinase-inducible domain (KID) as transcriptional activator can stimulate target gene expression in signal transduction by associating with KID interacting domain (KIX). NMR spectra suggest that apo-KID is an unstructured protein. After post-translational modification by phosphorylation, KID undergoes a transition from disordered to well folded protein upon binding to KIX. However, the mechanism of folding coupled to binding is poorly understood. Methodology To get an insight into the mechanism, we have performed ten trajectories of explicit-solvent molecular dynamics (MD) for both bound and apo phosphorylated KID (pKID). Ten MD simulations are sufficient to capture the average properties in the protein folding and unfolding. Conclusions Room-temperature MD simulations suggest that pKID becomes more rigid and stable upon the KIX-binding. Kinetic analysis of high-temperature MD simulations shows that bound pKID and apo-pKID unfold via a three-state and a two-state process, respectively. Both kinetics and free energy landscape analyses indicate that bound pKID folds in the order of KIX access, initiation of pKID tertiary folding, folding of helix αB, folding of helix αA, completion of pKID tertiary folding, and finalization of pKID-KIX binding. Our data show that the folding pathways of apo-pKID are different from the bound state: the foldings of helices αA and αB are swapped. Here we also show that Asn139, Asp140 and Leu141 with large Φ-values are key residues in the folding of bound pKID. Our results are in good agreement with NMR experimental observations and provide significant insight into the general mechanisms of binding induced protein folding and other conformational adjustment in post-translational modification.
An Efficient Control Strategy of Epidemic Spreading on Scale-Free Networks

HANG Hai-Feng,LI Ke-Zan,FU Xin-Chu,WANG Bing-Hong,

中国物理快报 , 2009,
Abstract: We present a novel and effective method for controlling epidemic spreading on complex networks, especially on scale-free networks. The proposed strategy is performed by deleting edges according to their significances (thesignificance of an edge is defined as the product of the degrees of two nodes of this edge). In contrast to other methods, e.g., random immunization, proportional immunization, targeted immunization, acquaintance immunization and so on, which mainly focus on how to delete nodes to realize the control of epidemic spreading on complex networks, our method is more effective in realizing the control of epidemic spreading on complex networks, moreover, such a method can better retain the integrity of complex networks.
Ultrafast Photodissociation Dynamics of the F State of Sulfur Dioxide by Femtosecond Time-Resolved Pump-Probe Method

ZHANG Dong-Dong,NI Qiang,LUO Si-Zuo,ZHANG Jing,LIU Hang,XU Hai-Feng,JIN Ming-Xing,DING Da-Jun,

中国物理快报 , 2011,
Using position specific scoring matrix and auto covariance to predict protein subnuclear localization  [PDF]
Rong-Quan Xiao, Yan-Zhi Guo, Yu-Hong Zeng, Hai-Feng Tan, Hai-Feng Tan, Xue-Mei Pu, Meng-Long Li
Journal of Biomedical Science and Engineering (JBiSE) , 2009, DOI: 10.4236/jbise.2009.21009
Abstract: The knowledge of subnuclear localization in eukaryotic cells is indispensable for under-standing the biological function of nucleus, genome regulation and drug discovery. In this study, a new feature representation was pro-posed by combining position specific scoring matrix (PSSM) and auto covariance (AC). The AC variables describe the neighboring effect between two amino acids, so that they incorpo-rate the sequence-order information; PSSM de-scribes the information of biological evolution of proteins. Based on this new descriptor, a support vector machine (SVM) classifier was built to predict subnuclear localization. To evaluate the power of our predictor, the benchmark dataset that contains 714 proteins localized in nine subnuclear compartments was utilized. The total jackknife cross validation ac-curacy of our method is 76.5%, that is higher than those of the Nuc-PLoc (67.4%), the OET- KNN (55.6%), AAC based SVM (48.9%) and ProtLoc (36.6%). The prediction software used in this article and the details of the SVM parameters are freely available at http://chemlab.scu.edu.cn/ predict_SubNL/index.htm and the dataset used in our study is from Shen and Chou’s work by downloading at http://chou.med.harvard.edu/ bioinf/Nuc-PLoc/Data.htm.
Synchronization and Pinning Control in Complex Networks with Interval Time-Varying Delay
Hai-Feng Jiang,Tao Li
Mathematical Problems in Engineering , 2012, DOI: 10.1155/2012/948495
Abstract: The problems on synchronization and pinning control for complex dynamical networks with interval time-varying delay are investigated and two less conservative criteria are established based on reciprocal convex technique. Pinning control strategies are designed to make the complex networks synchronized. Moreover, the problem of designing controllers can be converted into solving a series of NMIs (nonlinear matrix inequalities) and LMIs (linear matrix inequalities), which reduces the computation complexity when comparing with those present results. Finally, numerical simulations can verify the effectiveness of the derived methods.
Patterns and programming for ecoagricultural divisions in Jiansu Province

Li Hai-feng,

中国生态农业学报 , 1999,
Abstract: Based on the regional features of natural resources,development of production and social economic conditions, ecoagricultural divisions in Jiangsu Province were conducted in accordance with the principles of agricultural division. Suitable models for ecoagricultural construction for different regions were set up.
Effects of Naoerkang on expressions of β-amyloid peptide 1-42 and neprilysin in hippocampus in a rat model of Alzheimer's disease
Hai-feng YUAN,Xi LI
Zhong Xi Yi Jie He Xue Bao , 2010,
Abstract: Objective: To investigate the effects of Naoerkang (NEK), a compound traditional Chinese herbal medicine, on the expressions of β-amyloid peptide 1-42 (Aβ1-42) and neprilysin (NEP) in hippocampal tissues in a rat model of Alzheimers disease (AD). Methods: Forty-eight male SD rats were randomly divided into normal control group, untreated group, piracetam group, low-dose NEK group, medium-dose NEK group, and high-dose NEK group, with 8 rats in each group. Five microliters of Aβ1-42 (2 μg/μL) were injected into CA1 area of hippocampus in rat to establish AD model whereas the normal control rats were injected with same volume of normal saline for comparison. The rats in the NEK groups were treated respectively with high-, medium- and low-dose [60, 30, 15 g/(kg·d)] NEK for 28 days consecutively; piracetam [0.375 g/(kg·d)] was intragastrically administered to rats in the piracetam group; and normal saline was applied in the control and untreated groups. Y-maze test was used for behavioral study to test the learning and memory abilities of rats in different groups. The expressions of Aβ1-42 and NEP in hippocampus were determined by immunohistochemical method, and the results were analyzed by image acquisition and analysis system. Results: Injection of Aβ1-42 could induce learning and memory dysfunction and up-regulate Aβ1-42 expression in hippocampal tissue in rats of the untreated group. Compared with the normal control group, the abilities of learning and memory of rats in the untreated group were significantly decreased (P<0.01) and the expression of Aβ1-42 was significantly increased (P<0.01) after model establishment. After 28-day administration of NEK and piracetam, the abilities of learning and memory of AD rats in piracetam and low-dose, medium-dose and high-dose NEK groups were significantly improved as compared with the untreated group (P<0.01 or P<0.05); the expression of Aβ1-42 in hippocampal tissues was decreased (P<0.01 or P<0.05) and the expression of NEP was increased (P<0.01 or P<0.05), especially in the high-dose NEK group.Conclusion: NEK can play the role of anti-dementia by increasing the expression of NEP in hippocampal tissues of AD rats so as to reduce the quantity of Aβ1-42 and by improving the ability of learning and memory of rats with AD.
An Efficient and Flexible Engine for Computing Fixed Points
Hai-Feng Guo,Gopal Gupta
Computer Science , 2004,
Abstract: An efficient and flexible engine for computing fixed points is critical for many practical applications. In this paper, we firstly present a goal-directed fixed point computation strategy in the logic programming paradigm. The strategy adopts a tabled resolution (or memorized resolution) to mimic the efficient semi-naive bottom-up computation. Its main idea is to dynamically identify and record those clauses that will lead to recursive variant calls, and then repetitively apply those alternatives incrementally until the fixed point is reached. Secondly, there are many situations in which a fixed point contains a large number or even infinite number of solutions. In these cases, a fixed point computation engine may not be efficient enough or feasible at all. We present a mode-declaration scheme which provides the capabilities to reduce a fixed point from a big solution set to a preferred small one, or from an infeasible infinite set to a finite one. The mode declaration scheme can be characterized as a meta-level operation over the original fixed point. We show the correctness of the mode declaration scheme. Thirdly, the mode-declaration scheme provides a new declarative method for dynamic programming, which is typically used for solving optimization problems. There is no need to define the value of an optimal solution recursively, instead, defining a general solution suffices. The optimal value as well as its corresponding concrete solution can be derived implicitly and automatically using a mode-directed fixed point computation engine. Finally, this fixed point computation engine has been successfully implemented in a commercial Prolog system. Experimental results are shown to indicate that the mode declaration improves both time and space performances in solving dynamic programming problems.

SU Hang
, LI Zhi-bin, DU Jiang, JIANG Hai-feng, CHEN Zhi-kang, SUN Hai-ming, ZHAO Min

- , 2015, DOI: 10.3969/j.issn.1674-8115.2015.10.005

Abstract: 目的在一项5年的随访研究中探讨*********复吸预测因子气质、冲动性以及COMT基因多态性的性别差异。方法使用Barratt冲动量表、气质性格问卷评估564例*********依赖患者的冲动性、气质和性格特质。使用DNA序列检测系统检测COMT基因rs4680多态性。结果在564例*********依赖者中,完成5年随访的共有500例。在完成5年随访的患者中,有265例(53%)患者被确诊为*********复吸,其中男性127例,女性138例。Logistic回归分析显示:在5年随访过程中,男性冲动量表总分、美沙酮治疗史以及用药年限是*********复吸的预测因子;而在女性中,用药起始年龄、酒依赖史、美沙酮治疗史以及自我定向性得分是*********复吸的预测因子。结论气质、冲动性以及COMT基因多态性与*********复吸有关,这些因素在预测*********复吸的过程中存在性别差异。
: ObjectiveTo investigate gender differences of factors (temperament, impulsivity, and polymorphism of COMT gene) for predicting the relapse of heroin by a 5-year follow up.MethodsImpulsivity, temperament, and character of 564 heroin dependent patients were evaluated by Barratt impulsiveness scale (BIS) and temperament and character inventory. The polymorphism of COMT gene rs4680 was detected by a DNA sequence detection system.ResultsAmong 564 heroin dependent patients, 500 patients were followed up for 5 years. 265 (53%) of them relapsed into heroin and 127 patients were male and 138 patients were female. Logistic regression analysis showed that the total score of BIS, methadone maintenance treatment, and duration of heroin use were factors for predicting the relapse of heroin according to 5 years of follow up. For females, the starting age of heroin use, alcohol dependent, methadone maintenance treatment, and score of self orientation were factors for predicting the relapse of heroin.ConclusionThe impulsivity, temperament, and polymorphism of COMT gene are relevant to the relapse of heroin. Gender differences exist for predicting the relapse of heroin by these factors
Theoretical study of thermodynamic properties of metal Be

Song Hai-Feng,Liu Hai-Feng,

物理学报 , 2007,
Abstract: We present first-principles calculations combined with mean-field potential model to study the thermodynamic properties of hexagonal-close-packed (hcp) Be for pressures up to 150GPa and temperatures up to 1500K, including the properties of Be under ambient conditions, the isothermal equation of state up to high pressure, the temperature dependence of equilibrium volumes and bulk modulus under ambient pressure, and Hugoniot curve in the P-V plane. The equationof state at zero temperature is computed based on density-functional theory within the generalized-gradient approximation. The vibrational contributions are calculated by the mean-field potential model. Due to high Debye temperature of Be, we consider the zero-point energy correction to the free energy. The calculated properties are in good agreement with available static and shock-wave experimental measurements.
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