Effect of traditional Chinese medicine berberine on type 2 diabetes based on comprehensive metabonomics

A comprehensive metabonomic method, in combination with fingerprint analysis and target analysis, was performed to reveal potential mechanisms of berberine action in the treatment of patients with type 2 diabetes and dyslipidemia. Serum samples of 60 patients before and after treatment with either berberine or placebo were collected. Ultra-performance liquid chromatography and quadrupole time-of-flight tandem mass spectrometry (UPLC Q-TOF MS) coupled with pattern recognition analysis were used to identify changes in global serum metabolites. Compared with placebo, patients before and after berberine treatment could be separated into distinct clusters as displayed by the orthogonal signal correction filtered partial least-squares discriminant analysis (OSC-PLS-DA) score plot, which indicated changes in circulating metabolites after berberine treatment. Among them, free fatty acids changed markedly. These were further quantified by UPLC combined with single quadrupole mass spectrometry (UPLC SQ MS). There was a highly significant decrease in the concentrations of 13 fatty acids following berberine administration. 10 fatty acids also differed statistically from placebo. These results suggest that berberine might play a pivotal role in the treatment of type 2 diabetes through down-regulating the high level of free fatty acids and that comprehensive metabonomic measurements are potentially very useful for studying the mechanisms of action of traditional Chinese medicines.     

An RNA folding algorithm including pseudoknots based on dynamic weighted matching

On the basis of maximum weighted matching (MWM) algorithm, we introduced a dynamic weight related with stem length and used a recursive algorithm to predict RNA secondary structures by searching the stem structure with maximum weight summation step-by-step. This algorithm not only avoids the complicated free energy calculation, but also it could attain higher prediction accuracy. Moreover, our algorithm can predict most types of potential pseudoknots in the RNA structure.     

THE POLYMERIZATION OF d-ELEOSTEARIC ACID IN THE DIPALMITOYLPHOSPHATIDYLCHOLINE-α-ELEOSTEARIC ACID LIPOSOME*

The polymerization of α-eleostearic acid (α-ESA) in the dipalmitoylphosphatidylcholine (DPPC)-α-ESA liposome was studied. The polymerization was carried out by UV irradiation and was kineticfirst order. The rate constant depends on the ratio of DPPC to α-ESA in the liposome. A transitionpoint of reaction rate could be observed in the course of the polymerization, and it appearedearlier with elevated temperature. Before the transition point, the higher the DPPC to α-ESAratio the higher was the reaction rate; while after the transition point, the higher the DPPC to α-ESAratio the lower wa the reaction rate.     

The synthesis and identification of new heavy neutron-rich nuclide237Th

The unreported heavy neutron-rich nuclide²³⁷Th has been identified for the first time. Sources of²³⁷Th prepared by 14-MeV neutron irradiation of uranium followed by radiochemical separation have been studied. The new activity of²³⁷Th was identified by following the time variation of the characteristic γ-rays. The half-life of²³⁷Th has been determined to be 5.0±0.9 min.     

聚苯胺用作乙醇脱氢反应中的电子传递介质

脱氢酶（ADH）在电化学氧化还原反应中是很重要的一种酶,但它在催化有机分子脱氢反应时需烟酰胺腺嘌呤二核苷酸（NAD＋）参与,后者从底物接收电子生成还原形NADH.脱氢酶电极是根据NADH的电化学氧化产生的阳极电流构成的[1－3].然而NADH与裸体炭电极和铂金电极之间的直接电子传递是非常困难的,往往需一个相当高的过电位[4].另一个问题是生成物易将电极玷污[5,6].克服这些问题的方法是使用均相电子传递介质,例如在底物溶液中加入Meldola蓝、Nile蓝A和NMP＋甲替硫酸盐等[7－9],及复相电子传递介质,例如将镍六氰基高铁酸盐固…     

Structure–Property Investigations of Substituted Triarylamines and Their Applications as Fluorescent pH Sensors

Fourteen triphenylamine derivatives functionalized with fluorophenyl, methoxyphenyl, and pyridinyl groups as respective donors and acceptors were synthesized and characterized. Their photophysical properties were systematically investigated in various solvents with different polarities. The solvent‐dependent Stokes shifts of these compounds were observed and analyzed by the Lippert–Mataga equation. The synthesized compounds, especially tris(4‐(pyridin‐4‐yl)phenyl) amine, presented pH‐dependent absorptions and emissions, indicating that these compounds might be used as pH sensors.     

CHARMM‐GUI Membrane Builder toward realistic biological membrane simulations

CHARMM‐GUI Membrane Builder, http://www.charmm‐gui.org/input/membrane , is a web‐based user interface designed to interactively build all‐atom protein/membrane or membrane‐only systems for molecular dynamics simulations through an automated optimized process. In this work, we describe the new features and major improvements in Membrane Builder that allow users to robustly build realistic biological membrane systems, including (1) addition of new lipid types, such as phosphoinositides, cardiolipin (CL), sphingolipids, bacterial lipids, and ergosterol, yielding more than 180 lipid types, (2) enhanced building procedure for lipid packing around protein, (3) reliable algorithm to detect lipid tail penetration to ring structures and protein surface, (4) distance‐based algorithm for faster initial ion displacement, (5) CHARMM inputs for P₂₁ image transformation, and (6) NAMD equilibration and production inputs. The robustness of these new features is illustrated by building and simulating a membrane model of the polar and septal regions of E. coli membrane, which contains five lipid types: CL lipids with two types of acyl chains and phosphatidylethanolamine lipids with three types of acyl chains. It is our hope that CHARMM‐GUI Membrane Builder becomes a useful tool for simulation studies to better understand the structure and dynamics of proteins and lipids in realistic biological membrane environments. © 2014 Wiley Periodicals, Inc.     

一类随机时延网络控制系统的神经网络自适应容错控制

针对一类随机时延网络控制系统,提出一种基于RBF神经网络自适应动态补偿的容错控制策略.该方法通过在线估计时延将系统建模为随机切换系统,并在模型参考自适应方法的基础上设计RBF神经网络动态补偿容错控制器,利用Lyapunov稳定性理论给出神经网络补偿器的在线权值学习算法,以保证网络控制系统在故障情况下的跟踪性能和状态一致最终有界稳定.最后通过仿真验证了该方法的有效性.     

Boson pairing and unusual criticality in a generalized XY model

We discuss the unusual critical behavior of a generalized XY model containing both 2π-periodic and π-periodic couplings between sites, allowing for ordinary vortices and half-vortices. The phase diagram of this system includes both single-particle condensate and pair-condensate phases. Using a field theoretic formulation and worm algorithm Monte?Carlo simulations, we show that in two dimensions it is possible for the system to pass directly from the disordered (high temperature) phase to the single particle (quasi)condensate via an Ising transition, a situation reminiscent of the "deconfined criticality" scenario.