无量山种子植物区系科属的两种不同排序

地处滇中南的景东无量山地区迄今计种了植物２０７科,１０２６属,２５４０种,按照传统的种的绝对数目进行科属的排序可以得到一个较为完整的区系组成,但无法反映这些属在该地区系建成中的相对重要性,本文提出了区系存在度,即某一科（属）在该地再现的次级分类群与它的所有次级分类的比值,按之再去进行排列,可得到一个迥然有异的排序,按绝对种数排序的大科在第二种排序中很少进入,相反,一些东亚特有或有邻近地区共有的科的     

研究生病理学实验带教的探索与实践

医学研究生教育的目的是培养高素质创新型医学人才,创新离不开科研,病理学是多学科科研究工作的基础。建立科研平台提高科研能力是研究生教育十分关注的问题。如何培养研究生病理学实验能力,使学到知识技术在今后的科研活动中得以运用,本文就近几年我们在研究生病理学实验带教实践过程中的一些方法作一介绍。     

CD44v6、MMP-9、VEGF在胃癌的表达及临床意义

目的:检测胃癌组织中CD44v6、MMP-9、VEGF表达情况及其与胃癌临床病理因素的关系,并探讨其表达与胃裸区侵犯的临床意义。方法:采用免疫组化方法测定60例胃癌组织CD44v6、MMP-9、VEGF表达情况,并结合患者的临床病理资料进行分析。结果:CD44v6、MMP-9、VEGF的表达与胃癌的TNM分期、浸润深度、淋巴结转移有关。胃裸区受侵组与未受侵组胃癌组织的CD44v6、MMP-9、VEGF的表达无明显差异。结论:CD44v6、MMP-9、VEGF的表达与胃癌的浸润转移密切相关,胃裸区是否受侵与胃癌组织的CD44v6、MMP-9、VEGF的表达无关,胃裸区这一解剖结构可能是胃癌预后较差的原因。     

高梁抗蚜研究进展

高粱(Sorghum bicolour)是世界上最重要的粮食、饲料、酿造和能源作物之一,也是C4植物研究的模式植物.蚜虫是农业生产上的重要害虫,几乎危害所有的栽培作物.危害高粱的蚜虫主要包括高粱蚜(Melanaphis sacchan)、麦二叉蚜(Schizaphis graminum)和玉米蚜(Rhopalosiphum maidis).高粱的抗蚜资源尚不丰富且缺乏深入系统的研究.目前研究较多的是麦二叉蚜的抗性遗传方面,已定位20个抗性QTLs,单一QTL对抗性差异贡献率最高可达80.3％,对高粱蚜和玉米蚜的研究尚需进一步加强.高粱的理化特性与其抗蚜性能相关,故可与育种实践相结合.高粱和蚜虫(Acyrthosiphon pisum)的全基因组测序工作已经完成,这将有助于蚜虫-植物间的相互作用关系及植物对蚜虫的抗性机制研究.目前已克隆到2个抗蚜基因,且多个抗蚜基因(位点)已被定位在染色体上.该文重点综述了上述研究成果并对高粱抗蚜的研究前景进行了展望.     

Protein-protein interaction site predictions with three-dimensional probability distributions of interacting atoms on protein surfaces

Protein-protein interactions are key to many biological processes. Computational methodologies devised to predict protein-protein interaction (PPI) sites on protein surfaces are important tools in providing insights into the biological functions of proteins and in developing therapeutics targeting the protein-protein interaction sites. One of the general features of PPI sites is that the core regions from the two interacting protein surfaces are complementary to each other, similar to the interior of proteins in packing density and in the physicochemical nature of the amino acid composition. In this work, we simulated the physicochemical complementarities by constructing three-dimensional probability density maps of non-covalent interacting atoms on the protein surfaces. The interacting probabilities were derived from the interior of known structures. Machine learning algorithms were applied to learn the characteristic patterns of the probability density maps specific to the PPI sites. The trained predictors for PPI sites were cross-validated with the training cases (consisting of 432 proteins) and were tested on an independent dataset (consisting of 142 proteins). The residue-based Matthews correlation coefficient for the independent test set was 0.423; the accuracy, precision, sensitivity, specificity were 0.753, 0.519, 0.677, and 0.779 respectively. The benchmark results indicate that the optimized machine learning models are among the best predictors in identifying PPI sites on protein surfaces. In particular, the PPI site prediction accuracy increases with increasing size of the PPI site and with increasing hydrophobicity in amino acid composition of the PPI interface; the core interface regions are more likely to be recognized with high prediction confidence. The results indicate that the physicochemical complementarity patterns on protein surfaces are important determinants in PPIs, and a substantial portion of the PPI sites can be predicted correctly with the physicochemical complementarity features based on the non-covalent interaction data derived from protein interiors.     

白芨的组培快繁(简报)

本文扼要地阐述了以白芨种子为培养材料,经筛选的培养基诱导、分化、生长,最终可获得苗质好、性状均一的白芨;为进一步研究快速繁殖白芨提供参考.     

Characterizing the structural diversity of a bacterial community associated with filter materials in recirculating aquaculture systems of Scortum barcoo

The bacterial community structure associated with filter materials in the recirculating aquaculture system of Scortum barcoo was investigated using the 16S rRNA gene clone library method. Preliminary results showed that the clone library constructed from the initial operation condition was characterized by 31 taxa of bacteria belonging to eight phyla including Proteobacteria, Acidobacteria, Firmicutes, Fusobacteria, Sphingobacteria, Bacteroidetes, Verrucomicrobiae, and Actinobacteria. There were 14 taxa of bacteria belonging to four phyla including Proteobacteria, Acidobacteria, Planctomycetacia, and Nitrospirae from the stable operation condition where the water quality was well maintained. Nitrospirae was only found under the stable operation condition in this study. Our results further indicated that Nitrospira was dominated by members of the Nitrospira sp. lineages, with a minor fraction related to Nitrospira moscoviensis and an unknown Nitrospira cluster. These great differences of both diversity and composition between two operation conditions suggested that the composition of the microbial community varied with the degree of water quality in the recirculating aquaculture system of S.?barcoo.