Diagnostic value of Gram stain for assessment of vaginal smears during pregnancy

The main aim of this study was to compare the diagnostic value of Giemsa stained method with Gram stained method for the evaluation of vaginal smears among pregnant women. A study population comprised 111 pregnant between 6 and 30 weeks of gestation. The vaginal smears from every subject was diagnosed according to Giemsa and Gram stained method and micro-organisms were isolated by culture. In 29.3% cases diagnosed as normal flora (2a) on the basis of Giemsa method bacterial vaginosis was detected in Gram stains according to Spiegel's criteria and pathological microflora in concentration > or = 10(5) CFU/ml was cultured among 75.9% of them. Among 31.7% women who had grade 3a (abnormal) in Giemsa stains method normal flora was diagnosed on the basis on Gram's method and from 17.1% pregnant women from this group we did not isolated any pathogens. For evaluation of vaginal smears during pregnancy the Giemsa method should be replaced by Gram stained method.     

Comparison of 2 methods of determining the kinetics of a bicompartmental system. Application to the measurement of cutaneous blood flow

Peeling method and a non linear regressions method (Newton's method) have been tested on experimental and simulated data. Newton's method is the most accurate and precise when running on simulated data. Experimental curves artefacts make Newton's algorithm automatically running less efficient than classical peeling algorithm working in interactive mode.     

脑磁图神经活动源数目的估计

在脑磁图信号的分析中,正确估计出脑磁图神经活动源的数目是进一步分析脑磁图信号的前提。目前广泛采用的信息论方法和主成分分析方法都是根据特征值来确定源的数目,这两种方法在源数目较多、噪声较强的情况下,会导致误判。该文提出了一种噪声调节自动阈值的脑磁图源数目判断方法,利用基于噪声调节的主成分分析并结合聂曼- 皮尔逊准则对脑磁图源数目进行估计。同时,该方法采用了基于小波的噪声方差估计,实现了脑磁图信号中噪声方差的精确估计。通过对基于信息论方法、主成分分析方法以及该文所提议方法的实验结果的比较,表明该文所提议方法能更准确地估计脑磁图源数目,特别是在源数目较多、信噪比较小的情况下,仍能准确地估计脑磁图源数目,具有较大的实际意义。     

Identification of RNA-Recognizing Modules on the Surface of Ribosomal Proteins

Specific binding of ribosomal proteins to rRNA has been analyzed, and the method for determining the recognizing modules on the protein surface has been proposed. This method is based on the search for the atoms on the protein molecule that are involved in the conserved hydrogen bonds with rRNA and form invariant spatial structure in both free and RNA-bound ribosomal proteins. The potential of this method is illustrated by determining the rRNA-recognizing modules on the surface of ribosomal proteins S8, S15, and L5.     

溶菌酶的活性测定方法

溶菌酶是一种与单核 -巨噬细胞系统有关的非特异防御机制 ,参与机体的免疫作用 ,测定溶菌酶活性值日益受到临床重视。国内外目前采用比浊法 ,琼脂板扩散法 ,比色测定法 ,琼脂火箭糖电泳法和高效液相色谱法。前两种方法较为常用 ,但干扰因素多 ,实验结果的重现性差 ;比色法操作简单但误差较大。以琼脂火箭糖电泳法和高效液相色谱法的测定效果最为理想。     

Quantitation of immobilized proteins

A method for the quantitative determination of immobilized proteins based on the binding and subsequent elution of Coomassie Blue R is presented. Also presented is a method for the immobilization of proteins in solution by entrapment in polyacrylamide. These entrapped proteins are then available for use in the assay method presented. Other analytical procedures can also be performed on the entrapped proteins, either alone or in combination with the protein quantitation. The dye binding and elution method presented provides a sensitive and, in most applications, rapid method for the quantitative detection of immobilized proteins. Rather than immobilization being an obstacle to the assay method, this approach utilizes the advantages of immobilization for the removal of excess reagents. Application of this approach to several types of immobilized protein are presented.     

Stochastic mapping of morphological characters

Many questions in evolutionary biology are best addressed by comparing traits in different species. Often such studies involve mapping characters on phylogenetic trees. Mapping characters on trees allows the nature, number, and timing of the transformations to be identified. The parsimony method is the only method available for mapping morphological characters on phylogenies. Although the parsimony method often makes reasonable reconstructions of the history of a character, it has a number of limitations. These limitations include the inability to consider more than a single change along a branch on a tree and the uncoupling of evolutionary time from amount of character change. We extended a method described by Nielsen (2002, Syst. Biol. 51:729-739) to the mapping of morphological characters under continuous-time Markov models and demonstrate here the utility of the method for mapping characters on trees and for identifying character correlation.     

Identification of RNA-recognizing modules on the surface of ribosomal proteins

Properties of specific interaction between ribosomal proteins and ribosomal RNAs were analyzed and a method for determination of "recognizing modules" on the protein surface was proposed. The method is based on the search of protein atoms making conserved H-bonds with RNA and forming an invariant spatial structure in homologous rRNA-protein complexes and in the isolated protein. A potential of the method is demonstrated on the determination of the recognizing modules on the surfaces of ribosomal proteins S8, S15 and L5.     

Fractionation of the nucleotides of the acid-soluble liver fraction of rats

A method for separation of rat liver acid-soluble nucleotides was developed including ion exchange polyethyleneimine cellulose chromatography, followed by rechromatography of the separate fractions on Dowex 1 and Aminex MS resins. It is simple, reproducible and does not require expensive reagents and devices. The sensitivity of the method in respect to orotate is 100 pM in a sample. Data on the content of liver basic 5'-ribonucleotides and their derivatives were obtained by the proposed method.     

分子系统进化关系分析的一种新方法--贝叶斯法在硬蜱属中的应用

距离矩阵邻接法、最大简约法和最大似然法是重建生物系统关系的3种主要方法。普遍认为最大似然法在原理上优于前二种方法，但其计算复杂费时。由于现行计算机的能力尚达不到其要求而实用性差，特别是在处理大数据集样本(即大于25个分类单元)时，用此方法几乎不可能。新近提出的贝叶斯法(Bayesianmethod)既保留了最大似然法的基本原理，又引进了马尔科夫链的蒙特卡洛方法，并使计算时间大大缩短。本文用贝叶斯法对硬蜱属(Ixodes)19个种的线粒体16S rDNA片段进行了系统进化分析。从总体上看，分析结果与现有的基于形态学的分类体系基本吻合。但与现存的假说相反，莱姆病的主要宿主蓖籽硬蜱复合种组并非单系。通过比较贝叶斯法与其它三种方法的结果，我们认为贝叶斯法是一种系统进化分析的好方法，它既能根据分子进化的现有理论和各种模型用概率重建系统进化关系，又克服了最大似然法计算速度慢、不适用于大数据集样本的缺陷。贝叶斯法根据后验概率直观地表示系统进化关系的分析结果，不需要用自引导法进行检验。可以预料，贝叶斯法将会被广泛地应用到系统进化分析上[动物学报49(3)：380—388，2003]。     

T细胞亚群CD4测定方法的研究

为比较外周血T淋巴细胞亚群CD4不同测定方法的差别,以流式细胞术为定量手段,测定了猴外周血中三种不同方法处理后CD4的表达.结果表明：先标后溶法——先用异硫氰荧光素标记的单克隆抗体（FITC-CD4 McAb）标记后,再加入红细胞溶解液溶掉红细胞的处理方法,结果基本等同于传统的淋巴细胞分离法,但样本用量仅为传统方法的1/5,且操作简单.激光共焦显微术的形态学研究也证实：先标后溶法与淋巴细胞分离法相似,其细胞膜表面荧光标记清晰,优于先溶后标法.     

Effects of porcine faecal lactobacilli on the rate of growth of enterotoxigenic Escherichia coli O149: K88: K91

A quantitative method for screening the effects of Lactobacillus spp. on an enterotoxigenic strain of Escherichia coli is described. The method determines the effects of the lactobacilli on the specific growth rate of the coliform while in associative culture, so that the lactobacilli may be differentiated on the basis of the extent of inhibition. The method is reproducible and is not operator dependent.     

A comparison of four methods for measuring roots of field crops in three contrasting soils

Rooting measurements have been made at different growth stages for sugar beets (1987) and for cereals (1988) on three different sites using four different root measurement techniques: (a) the core method where roots were extracted and root length is directly measured, (b) the core-break method where the visible roots were counted on the faces of a broken soil column, (c) the trench profile wall method where the number of visible roots were counted and the root length density was estimated on a profile wall, and (d) the monolith method where the roots were extracted from monoliths dug out from a profile wall. The calibration curves between the field methods and the extraction methods were not linear, and regression coefficients differed significantly between different sites, crops and between fields with different agronomic management, e.g. irrigation and liquid manure application. Differences between growth stages were comparably low compared with those found between locations. Root length densities obtained with the trench profile method were on average 10-fold lower in the sand brown earth, 6-fold lower in the vertisol and 4 times lower in the cambisol compared to data obtained with the core method. It is therefore concluded that the core-break method and the trench profile wall method deliver no reliable data for comparing rooting intensities between different soils and between different crops if they are not calibrated with an extraction method for each site and crop.     

Condition Number Estimation of Preconditioned Matrices

The present paper introduces a condition number estimation method for preconditioned matrices. The newly developed method provides reasonable results, while the conventional method which is based on the Lanczos connection gives meaningless results. The Lanczos connection based method provides the condition numbers of coefficient matrices of systems of linear equations with information obtained through the preconditioned conjugate gradient method. Estimating the condition number of preconditioned matrices is sometimes important when describing the effectiveness of new preconditionerers or selecting adequate preconditioners. Operating a preconditioner on a coefficient matrix is the simplest method of estimation. However, this is not possible for large-scale computing, especially if computation is performed on distributed memory parallel computers. This is because, the preconditioned matrices become dense, even if the original matrices are sparse. Although the Lanczos connection method can be used to calculate the condition number of preconditioned matrices, it is not considered to be applicable to large-scale problems because of its weakness with respect to numerical errors. Therefore, we have developed a robust and parallelizable method based on Hager’s method. The feasibility studies are curried out for the diagonal scaling preconditioner and the SSOR preconditioner with a diagonal matrix, a tri-daigonal matrix and Pei’s matrix. As a result, the Lanczos connection method contains around 10% error in the results even with a simple problem. On the other hand, the new method contains negligible errors. In addition, the newly developed method returns reasonable solutions when the Lanczos connection method fails with Pei’s matrix, and matrices generated with the finite element method.     

PBL教学模式在我国医学本科生中教学效果的Meta分析

目的:系统评价我国以问题为基础的教学(problem-based learning,PBL)模式在医学本科生中的教学效果。方法:运用计算机检索中国知网、万方数据库、维普数据库收录的国内公开发表以问题为基础的本科医学生教育相关的临床研究文献,同时进行Meta分析。结果:共检索出783篇相关文献,通过筛选共有9篇文献纳入研究,共计纳入986例教学对象。纳入文献Jadad评分2-3分,纳入文献均说明基线资料均有可比性。对所有文献进行合并分析显示,PBL教学法的教学效果与传统教学组有显著差异(Z=6.52,P0.00001),PBL教学法优于传统教学法[SMD=7.72,95%CI[5.4,10.04],P0.00001]。结论:采用PBL教学法的教学效果优于传统教学法。但我国医学教育应用此方法仍不普及,其原因有待深入探讨,现有研究质量普遍不高,有待普及规范标准的研究方法。     

PACS辅助教学在医学影像学实习教学中的应用探讨

尝试应用影像存储及传输系统(Picture Archiving and Communication System,PACS),对我院临床本科生进行影像学实习教学。首先应用PACS建立电子影像学图片库,学生在PACS联网的计算机上学习教学内容,通过定期随堂测验、期末考试和课后问卷调查评估PACS辅助教学的教学效果,对PACS辅助教学在医学影像学实习教学中的应用价值进行探讨。与以往传统医学影像学实习教学方法相比,PACS辅助教学在医学影像学实习教学中具有激发学生学习主动性、提高学习效率和学生读片能力的优越性,显著提高教学效果和教学质量,对促进医学影像学教学改革具有重要意义。     

椰汁体外抑菌效应的研究

目的研究椰汁对常见致病菌的体外抑菌效应。方法采用纸片扩散法（K－B法）、试管稀释法（MIC法）、吸光度值测定法和生长曲线法来观察椰汁对常见致病菌的体外抑菌效应。结果椰汁对4种常见致病菌的生长均表现出抑制效应,尤其对伤寒沙门菌的抑制作用最强。结论椰汁对常见致病菌表现出一定的抑菌效应。     

Silver staining of proteins on electroblotting membranes and intensification of silver staining of proteins separated by polyacrylamide gel electrophoresis

A fast and convenient method for silver staining of proteins on electroblotting membranes was developed based on Gallyas' histochemical intensifier and applied to human endothelial cell proteins separated by one- and two-dimensional electrophoresis and electroblotted to polyvinyl difluoride membranes. The method allowed detection of proteins on membranes with a sensitivity equal to the sensitivity of the most sensitive silver-staining protocols for electrophoresis gels. Also, the method was compatible with preceding immunostaining on the same membrane. Furthermore, an intensifying method for proteins in silver-stained SDS-PAGE gels was developed based on Gallyas' histochemical intensifier. This method was applied to proteins separated by one- and two-dimensional gel electrophoresis and visualized by one of several silver-staining methods. Maximal intensification was achieved for the less sensitive but fast acidic silver-staining protocols, but even for the very sensitive alkaline protocols a significant increase in signal to noise ratio was obtained. In particular, negatively stained or invisible proteins on the silver-stained gels were found to be visualized by the Gallyas stain. Proteins from silver-stained and Gallyas-stained gels were identified by mass spectrometry, and the intensification procedure was fully compatible with mass spectrometry.     

棉蚜饲养技术——笼罩法

在长期的试虫饲养过程中 ,摸索出一种新的棉蚜饲养方法———笼罩法。利用A4幅面的透明胶片和纱网制成笼罩。并于室内催芽 ,培育棉花种苗 ,可利用自制笼罩于光照培养箱内隔离饲养棉蚜 ,经与琼脂叶片法和自制Blackmanbox方法比较 ,笼罩法具有省时省力、不受季节限制、棉蚜生长条件好以及取食活体植株等许多突出的优点。