Governmental policies on HIV infection in China

EVOLUTION OF THE GOVERNMENT POLI- CIES Looking back 20 and more years, one could have hardly imagined that such great changes would have happened to the governmental policies on HIV/AIDS in China. In the earlier phase of the epidemic, laws and regulations were drafted based on the practices and experiences of preven- tion and control of other infectious diseases, such as isolation, quarantine and compulsory testing and examina- tions etc. When the HIV/AIDS epidemic was firstl…     

一种显微图像的拼接方法

描述了一种显微图像拼接的方法,共包括特征检测、特征匹配、空间坐标转换和图像混合等四个步骤。实验结果显示本方法对重叠面积在50％以上的显微图像,能够进行拼接并且都没有出现明显的缝隙、错位、变形、图像模糊、图像重影等错误。     

不同类型磁场对细胞作用的生物学研究

本文就不同参数的磁场的细胞生物学效应研究进行了综述 ,总结了不同类型不同物理参数的磁场对细胞生物学效应的研究成果 ,结合实验结果对磁场生物学效应的可能物理机制进行了初步探讨 ,并对磁场的细胞生物学效应的研究前景进行了展望。     

HIFU治疗下生物体焦域温度分布的研究与应用

高强度聚焦超声(HIFU)为无创治疗肿瘤带来了新的途径,本文对HIFU治疗下生物体焦域热分布和热传导模型的理论进行了初步的介绍,并在理论的指导下进行不同治疗剂量的实验研究,结果表明组织内具有热波传热效应,治疗时可以根据治疗剂量的需要选取不同的参数,以达到最佳治疗效果。     

Behavioral modification in choice process of Drosophila

Because of its clear genetic and developmental background, diversity of behavioral paradigms and neuroanatomy of the brain, Drosophila has become an important animal model for studying genetic, molecular and cellular bases of learning and memory[1]. Extensive research has explored the visual operant conditioning of Drosophila and related molecular bases[2—8]; recently, researchers began to address cognition-like functions and involved neural substrates[9—11]. In these studies, behavioral ana…     

PBOND： Web Server for the Prediction of Proline and Non-Proline cis / trans Isomerization

PBOND is a web server that predicts the conformation of the peptide bond between any two amino acids. PBOND classifies the peptide bonds into one out of four classes, namely cis imide (cis-Pro), cis amide (cis-nonPro), trans imide (trans-Pro) and trans amide (trans-nonPro). Moreover, for every prediction a reliability index is computed. The underlying structure of the server consists of three stages: (1) feature extraction, (2) feature selection and (3) peptide bond clas- sification. PBOND can handle both s...     

How Do Variable Substitution Rates Influence Ka and Ks Calculations？

The ratio of nonsynonymous substitution rate (Ka) to synonymous substitution rate (Ks) is widely used as an indicator of selective pressure at sequence level among different species, and diverse mutation models have been incorporated into several computing methods. We have previously developed a new γ-MYN method by capturing a key dynamic evolution trait of DNA nucleotide sequences, in consideration of varying mutation rates across sites. We now report a further improvement of NG, LWL, MLWL, LPB, MLPB, and ...     

模拟硫酸型、硝酸型及其混合型酸雨对油菜生理特性、生长和产量的影响

为了了解我国酸雨污染由硫酸型向硫-硝酸复合型转变所引起的环境效应,以油菜(Brassicanapus)为供试材料,在大田试验条件下,系统研究了模拟硫酸型(SAR)、硝酸型(NAR)及其混合型(MAR)酸雨对农作物生理特性、生长和产量的影响。结果表明,3种酸雨胁迫均能抑制油菜生理、生长和产量形成,但不同类型的酸雨间的抑制效应存在差异。当pH≤4.1时,SAR、NAR、MAR能破坏油菜叶质膜系统、降低光合色素含量及光合速率,从而抑制作物的光合作用;当pH≤3.1时,油菜叶面积减小,叶受害百分率明显增加。pH=4.1可作为酸雨对油菜产量的影响阈值。在pH=7.0–1.5的酸度范围内,油菜叶片膜透性、丙二醛含量、叶受害百分率表现为NARMARSAR,光合速率、光合色素含量、叶面积及产量则表现出SARMARNAR的变化特征。当pH4.1时,3种酸雨处理间差异均不明显,pH≤3.1时,3种酸雨间的胁迫效应差异显著增加(p0.05),且酸度越强,差异越大,其变化趋势为NARMARSAR。说明NAR和MAR胁迫对油菜生理、生长及产量的抑制较大。     

冷冻电镜密度图可视化软件VAT4M

基于冷冻电镜三维密度图的特征分析,研究开发了冷冻电镜密度图可视化软件VAT4M(Visual Analysis Tools for Macro-Molecule Map and Model),实现了对三维冷冻电镜密度图的可视化分析,其主要功能包括密度图和分子模型的可视化、密度图的分割和晶体结构在密度图中的匹配。在可视化方面,在实现等值面可视化方法的同时还实现了体绘制可视化模式。对于结构分析,VAT4M提供了自动分割工具,和所见即所得的分割浏览器。同时,VAT4M还提供了极值吸收法与梯度法相结合的自动匹配方法,而且,对于具有对称性的密度图,可根据一个亚基的匹配结果,迅速得到其准原子模型。最后给出了若干应用实例。实验表明,本平台对冷冻电镜密度数据具有良好的可视与分析功能。