下缘芳香取代结构对杯[4]芳烃Langmuir膜的影响

The Langmuir monolayer properties of lower rim aromatically substituted calix[4]arenes, 5,11,17,23-tetra-tert-butyl-25,27-bis（2-naphth-1＇-ylacetylaminoethoxy）-26,28-dihydroxylcalix[4]arene （BNAEC）, 5,11,17,23-tetra-tert- butyl-25,27-bis（2-benzoylamino ethoxy）-26,28-dihydroxylcalix[4]arene （BBAEC） and 5,11,17,23-tetra-tert-butyl- 25,27-bis（2-cinnamoylaminoethoxy）-26,28-dihydroxylcalix[4]arene （BCAEC）, have been studied. Film balance measurements and Brewster angle microscopy （BAM） observation demonstrate that all the compounds can form Langmuir monolayers with different molecular limiting areas. BNAEC or BBAEC monolayer is able to form condensed domains during compression, while BCAEC monolayer can never form condensed domain. BNAEC monolayer is more readily to form condensed domain than BBAEC monolayer. Moreover, BNAEC monolayer can form the total condensed phase during compression even when T=28℃, while BBAEC monolayer can not when T 〉 10 ℃. The results imply that different lower rim aromatic substitutions affect essentially the intermolecular interaction and molecular packing in the monolayer at air/water interface.     

The Molecular and Pathophysiological Functions of Members of the LNX/PDZRN E3 Ubiquitin Ligase Family

The ligand of Numb protein-X (LNX) family, also known as the PDZRN family, is composed of four discrete RING-type E3 ubiquitin ligases (LNX1, LNX2, LNX3, and LNX4), and LNX5 which may not act as an E3 ubiquitin ligase owing to the lack of the RING domain. As the name implies, LNX1 and LNX2 were initially studied for exerting E3 ubiquitin ligase activity on their substrate Numb protein, whose stability was negatively regulated by LNX1 and LNX2 via the ubiquitin-proteasome pathway. LNX proteins may have versatile molecular, cellular, and developmental functions, considering the fact that besides these proteins, none of the E3 ubiquitin ligases have multiple PDZ (PSD95, DLGA, ZO-1) domains, which are regarded as important protein-interacting modules. Thus far, various proteins have been isolated as LNX-interacting proteins. Evidence from studies performed over the last two decades have suggested that members of the LNX family play various pathophysiological roles primarily by modulating the function of substrate proteins involved in several different intracellular or intercellular signaling cascades. As the binding partners of RING-type E3s, a large number of substrates of LNX proteins undergo degradation through ubiquitin-proteasome system (UPS) dependent or lysosomal pathways, potentially altering key signaling pathways. In this review, we highlight recent and relevant findings on the molecular and cellular functions of the members of the LNX family and discuss the role of the erroneous regulation of these proteins in disease progression.     

Thermal degradation of lyocell,modal and viscose fibers under aggressive conditions

Lyocell, modal and viscose fibers were subjected to mercerization or to solar degradation. The ulterior thermal degradation was analyzed by means of differential scanning calorimetry (DSC). Thermal analysis shows wide exothermic processes that began between 250 and 300°C corresponding to the main thermal degradation and are associated to a depolymerization and decomposition of the regenerated cellulose. Thermal degradation was analyzed as a function of concentration and time. Lyocell fiber is the most stable under thermal degradation conditions. Furthermore, mercerized samples are initially more degraded and present a lower thermal stability.     

Molecular dynamics study of the influence of calcium ions on the conformation of gelsolin S2 domain

Gelsolin is an actin-severing protein whose action is promoted by Ca²⁺ ions and inhibited by binding to lipid phosphoinositides incorporated in the inner leaflet of the plasma membrane inner lipid bilayer. In this study, we carried out molecular dynamics (MD) simulations to investigate the influence of calcium cations on the conformation of gelsolin S2 domain. First, gelsolin S2 domain taken from the crystal structure of apo-gelsolin (PDB code: 1D0N) was subjected to three 1100 ps MD simulations in a periodic water box with the 5.0 force field at T=298 K. In the first simulation (S2_Ca²⁺) excess concentration of Ca²⁺ was applied, in the second one (S2_phys) the concentration of Ca²⁺ ions was physiological and in the third one (S2_w) no Ca²⁺ ions were added. The results of MD simulations showed high conformational flexibility of the N-terminal part of the S2 domain. S2_w deviated from the starting structure considerably more that S2_phys and S2_Ca²⁺ suggesting that Ca²⁺ ions stabilize the conformation of the S2 domain of gelsolin.     

基于论域和量值二类错误逻辑变量求解的识别对象状态转化及其决策应用研究

研究了空间事物特征为确定常量的条件下,论域和量值参数为变量且未知时,错误识别对象状态的转化.研究发现,当对象识别状态的论域和量值都为Ⅱ类时,可以采用错误矩阵一类4集合方程A_s∨X_(qg)■B_g构建二元置换变换错误矩阵集合方程,将错误的对象识别状态转化为应该状态.最后,通过生产决策的实例说明其实际决策应用价值.     

Stability analysis of a polymer film casting problem

The polymer cast film process consists of stretching a molten polymer film between a flat die and a drawing roll. Drawing instabilities are often encountered and represent a drastic limitation to the process. Newtonian fluid film stretching stability is investigated using two numerical strategies. The first one is a ‘tracking’ method, which consists of solving Stokes equations in the whole fluid area (extrusion die and stretching path) by finite elements. The interface is determined to satisfy a kinematic equation. A domain decomposition meshing technique is used in order to account for a flow singularity resulting from the change in the boundary conditions between the die flow region and the stretching path region. A linear stability method is then applied to this transient kinematic equation in order to investigate the stability of the stationary solution. The second method is a direct finite element simulation in an extended area including the fluid and the surrounding air. The time‐dependent interface is captured by solving an appropriate level‐set function. The agreement between the two methods is fair. The influence of the stretching parameters (Draw ratio and drawing length) is investigated. For a long stretching distance, a critical Draw ratio around 20 delimitating stable and unstable drawing conditions is obtained, and this agrees well with the standard membrane models, which have been developed 40 years ago. When decreasing the stretching distance, the membrane model is no longer valid. The 2D models presented here point out a significant increase of the critical Draw ratio, and this is consistent with experimental results. Copyright © 2015 John Wiley & Sons, Ltd.     

Remarks on the Skorohod problem and reflected Lévy driven SDEs in time-dependent domains

We consider the Skorohod problem for càdlàg functions, and the subsequent construction of solutions to normally reflected stochastic differential equations driven by Lévy processes, in the setting of non-smooth and time-dependent domains.     

Experimental verification of structural alerts for the protein binding of cyclic compounds acting as Michael acceptors

This study outlines how a combination of and in vitro data can be used to define the applicability domain of selected structural alerts within the protein binding profilers of the Organisation for Economic Co-operation (OECD) Quantitative Structure–Activity Relationship (QSAR) Toolbox. Thirty chemicals containing a cyclic moiety were profiled for reactivity using the OECD and Optimised Approach based on Structural Indices Set (OASIS) protein binding profilers. The profiling results identified 22 of the chemicals as being reactive towards proteins. Analysis of the experimentally data showed 19 of these chemicals to be reactive. Subsequent analysis allowed refinements to be suggested to improve the applicability domain of the structural alerts investigated. The accurate definition of the applicability domain for structural alerts within in silico profilers is important due to their use in chemical category in predictive and regulatory toxicology.