Nanostructured polymer blends: Synthesis and structure

Nanostructured polymer blends prepared via anionic ring opening polymerizations of cyclic monomers in the presence of a pre-made polymer melt exhibit a number of special properties over traditional polymer blends and homopolymers. Here, we report on a simple and versatile method of in situ polymerization of macrocyclic carbonates in the presence of a maleic anhydride polypropylene (mPP) matrix and a surface-active compatibilizer (i.e. PC grafted onto a mPP backbone generated in situ) to yield a micro- and nanostructured polymer blends consisting of a polycarbonate (PC) minor phase, and a polypropylene (PP) major phase. By varying the processing conditions and concentration of the macrocyclic carbonate it was possible to reduce the size of the PC dispersions to an average minor diameter of 150 nm. NMR and TEM characterizations indicate that the PC dispersions do not influence crystal content in the PP phase. Overall, the results point to a simple strategy and versatile route to new polymeric materials with enhanced benefits.     

浅谈游戏UI

两年前，笔者的上司就告诫笔者UI有很大发展潜力。果然，随着现在越来越多的游戏公司把目光投向休闲游戏的开发，UI设计人员的需求也相应大幅增长。最近很多公司都开始招揽UI设计师，专业的游戏UI设计师一时供不应求，待遇也比以前上涨很多。     

风起云涌

已经过去的世界电子竞技大赛（即WCG）,谁还继续去关心？一路回忆WCG2008的点点滴滴,我突然又忍不住激动起来。WCG2008对于我来说,究竟有着怎么样的印象？也许很难和大家解释,也许很难说得清楚,可能这一次深刻的德国之行将会永远定义于众多比赛在大脑中的呈现,那么我现在就回忆着记住它的理由吧。     

Domains of DnaA protein involved in interaction with DnaB protein, and in unwinding the Escherichia coli chromosomal origin

DnaA protein of Escherichia coli is a sequence-specific DNA-binding protein required for the initiation of DNA replication from the chromosomal origin, oriC. It is also required for replication of several plasmids including pSC101, F, P-1, and R6K. A collection of monoclonal antibodies to DnaA protein has been produced and the primary epitopes recognized by them have been determined. These antibodies have also been examined for the ability to inhibit activities of DNA binding, ATP binding, unwinding of oriC, and replication of both an oriC plasmid, and an M13 single-stranded DNA with a proposed hairpin structure containing a DnaA protein-binding site. Replication of the latter DNA is dependent on DnaA protein by a mechanism termed ABC priming. These studies suggest regions of DnaA protein involved in interaction with DnaB protein, and in unwinding of oriC, or low-affinity binding of ATP.     

显示设备

显示器用的液晶面板价格近期呈全线上扬的态势，从17英寸、19英寸到19英寸宽屏，都有2～6美元的价格上涨，这很可能预示着主流液晶显示器的价格即将全面反弹。不过，20英寸以上的液晶面板将改用第七代生产线，因此成本又会大幅度下调。因此，业界的普遍预期是液晶显示器价格短期内会有所波动，而大屏幕产品价格将长期走低。     

Wetting Kinetics and the Strength of Adhesive Joints

The work of adhesion, depending solely on the contact angle and surface tension, is unreliable as a guide to the strength of a joint. The kinetics of joint formation, exemplified by the rate of wetting, is also important and can be measured by rate of change of contact angle, a process for which an empirical equation has previously been suggested. A proposed mechanism introduces a viscosity term into the differential form of this equation.

A series of metal lacquers was prepared from epoxy, U/F and M/F resins in various ratios and also epoxy/P/F and epoxy/acrylic mixtures. Stainless steel substrates, coated with these lacquers were then cemented together using polyethylene as an adhesive. It is shown that joint strength correlates better with a high wetting constant (γ/ηL) than with a low contact angle except where this is very low.     

Verification of cardiac tissue electrophysiology simulators using an N-version benchmark

Ongoing developments in cardiac modelling have resulted, in particular, in the development of advanced and increasingly complex computational frameworks for simulating cardiac tissue electrophysiology. The goal of these simulations is often to represent the detailed physiology and pathologies of the heart using codes that exploit the computational potential of high-performance computing architectures. These developments have rapidly progressed the simulation capacity of cardiac virtual physiological human style models; however, they have also made it increasingly challenging to verify that a given code provides a faithful representation of the purported governing equations and corresponding solution techniques. This study provides the first cardiac tissue electrophysiology simulation benchmark to allow these codes to be verified. The benchmark was successfully evaluated on 11 simulation platforms to generate a consensus gold-standard converged solution. The benchmark definition in combination with the gold-standard solution can now be used to verify new simulation codes and numerical methods in the future.     

Tobacco etch virus protease: mechanism of autolysis and rational design of stable mutants with wild-type catalytic proficiency

Because of its stringent sequence specificity, the catalyticdomain of the nuclear inclusion protease from tobacco etch virus(TEV) is a useful reagent for cleaving genetically engineeredfusion proteins. However, a serious drawback of TEV proteaseis that it readily cleaves itself at a specific site to generatea truncated enzyme with greatly diminished activity. The rateof autoinactivation is proportional to the concentration ofTEV protease, implying a bimolecular reaction mechanism. Yet,a catalytically active protease was unable to convert a catalyticallyinactive protease into the truncated form. Adding increasingconcentrations of the catalytically inactive protease to a fixedamount of the wild-type enzyme accelerated its rate of autoinactivation.Taken together, these results suggest that autoinactivationof TEV protease may be an intramolecular reaction that is facilitatedby an allosteric interaction between protease molecules. Inan effort to create a more stable protease, we made amino acidsubstitutions in the P2 and P1' positions of the internal cleavagesite and assessed their impact on the enzyme's stability andcatalytic activity. One of the P1' mutants, S219V, was not onlyfar more stable than the wild-type protease (~100-fold), butalso a more efficient catalyst.     

Effectiveness of a video-based motivational skills-building HIV risk-reduction intervention for inner-city African American men.

Interventions to reduce HIV risk behavior have shown promise but have demonstrated inconsistent effects with heterosexual men. This article reports a cognitive-behavioral HIV risk reduction intervention designed for heterosexually active African American men. Men (N?=?117) recruited from a public clinic were randomly assigned to either (a) a 6-hr video-based small group motivational-skills intervention, or (b) a 6-hr video-based contact-matched HIV education comparison group. Results showed men in the motivational-skills intervention reported lower rates of unprotected vaginal intercourse and higher rates of condom use at the 3-month follow-up. However, because of increased condom use in the comparison condition, differences between groups dissipated 6 months following the intervention. These findings are among the first to demonstrate effects from a motivational-skills intervention for reducing HIV risk in men who have sex with women using a model designed to facilitate transferring prevention technology to community settings. (PsycINFO Database Record (c) 2010 APA, all rights reserved)