cDNA基因芯片数据分析软件的研发进展

数据分析与挖掘是基因芯片研究的关键和难点,而软件是数据分析方法实现的主要手段。我们从以下几个方面对cDNA基因芯片分析软件进行了综述。首先介绍了芯片数据的获取及分析的软件,然后概述了不同统计软件在芯片数据分析中的应用,并详细介绍几种常用的芯片数据分析软件,最后简述了基因网络分析及数据挖掘方面的软件。     

Structure and function of natural-killer-cell receptors

The function of natural-killer (NK) cells is modulated by the balance between a number of activating and inhibitory receptors. Killer immunoglobulinlike receptors (KIRs) are mostly inhibitory receptors. They play a critical role in recognizing self-class-I major histocompatibility complex (MHC) molecules and thus protect healthy host cells from NK-targeted lysis. In contrast, both NKG2D and CD16 are activating NK receptors that trigger the NK-cell lysis of various tumor and virally infected cells through either direct ligand engagement or antibody-dependent cellular cytotoxicity (ADCC). Through structural studies of members of these distinct receptor families, in particular, the structure and recognition between KIR2DL2 and HLA-Cw3, that between NKG2D and ULBP3, and that between CD16 and IgG Fc, considerable understandings have been achieved about their function and their ligand recognition.     

中国首批美沙酮维持治疗门诊病人入组情况及治疗维持率

目的：了解中国首批美沙酮维持治疗门诊病人数量变化情况并计算其治疗维持率。方法：使用美沙酮维持治疗管理系统软件收集中国首批8个美沙酮维持治疗门诊数据,并进行数据整理与分析。结果：除浙江舟山门诊、广西南宁门诊和贵州织金门诊以外,其余5个门诊的在诊病人数均在6个月以内超过100人。首批8个门诊6个月及12个月的平均维持率分别为63%和48%,其中个旧门诊6个月及12个月的治疗维持率均列8个门诊之首,分别为84%和65%。结论：中国首批8家美沙酮维持治疗试点门诊运转平稳,但仍需要提高病人治疗维持率。     

Rice as a model for centromere and heterochromatin research

Rice (Oryza sativa) has become an important model plant species in numerous research projects involving genome, molecular and evolutionary biology. In this review we describe the reasons why rice provides an excellent model system for centromere and heterochromatin research. In most multicellular eukaryotes, centromeres and heterochromatic domains contain long arrays of repetitive DNA elements that are recalcitrant to DNA sequencing. In contrast, three rice centromeres and the majority of the cytologically defined heterochromatin in the rice genome have been sequenced to high quality, providing an unparalleled resource compared to other model multicellular eukaryotes. Most importantly, active genes have been discovered in the functional domains of several rice centromeres. The centromeric genes and sequence resources provide an unprecedented opportunity to study function and evolution of centromeres and centromere-associated genes.     

Geometric modeling of the human torso using cubic hermite elements

We discuss the advantages and problems associated with fitting geometric data of the human torso obtained from magnetic resonance imaging, with high-order (bicubic Hermite) surface elements. These elements preserve derivative (C ¹) continuity across element boundaries and permit smooth anatomically accurate surfaces to be obtained with relatively few elements. These elements are fitted to the data with a new nonlinear fitting procedure that minimizes the error in the fit while maintainingC ¹ continuity with nonlinear constraints. Nonlinear Sobelov smoothing is also incorporated into this fitting scheme. The structures fitted along with their corresponding root meansquared error, number of elements used, and number of degrees of freedom (df) per variable are: epicardium (0.91 mm, 40 elements, 142 df), left lung (1.66 mm, 80 elements, 309 df), right lung (1.69 mm, 80 elements, 309 df), skeletal muscle surface (1.67 mm, 264 elements, 1,010 df), fat layer (1.79 mm, 264 elements, 1,010 df), and the skin layer (1.43 mm, 264 elements, 1,010 df). The fitted surfaces are assembled into a combined finite element/boundary element model of the torso in which the exterior surfaces of the heart and lungs are modeled with two-dimensional boundary elements and the layers of the skeletal muscle, fat, and skin are modeled with finite elements. The skeletal muscle and fat layers are modeled with bicubic Hermite linear elements and are obtained by joining the adjacent surface elements for each layer. Applications for the torso model include the forward and inverse problems of electrocardiography, defibrillation studies, radiation dosage studies, and heat transfer studies.     

Synthesis and Characterization of Segmented Poly(ether ester)s Containing H‐Bonding Units

A series of poly(ether ester)s containing different H‐bonding units (amide, carbamate, urea) was prepared by polycondensation in bulk, using Ti(OBu)₄ as a catalyst. The copolymers were obtained starting from PEG1000, 1,4‐butanediol, and a symmetrical, bis‐ester terminated monomer carrying H‐bonding units. These materials were designed for biomedical applications, in which ultimate biodegradability of the materials is required. The influence of the nature of the H‐bonding unit and of the length of the methylene spacer between H‐bonding groups on the thermal and solubility properties of copolymers was investigated. Amide containing copolymers were more thermally stable than ones containing carbamate, consistent with the observed behavior of the corresponding monomers. In most cases, differential scanning calorimetry (DSC) traces were quite complex because of phase separation and dependent on the applied cooling rate. Copolymers containing urea bonds were less soluble in most organic solvents, but their thermal properties were not significantly different than their amide containing counterparts.

Synthesis of amide‐based diester monomers.     

The topology of early- and late-replicating chromatin in differentially decondensed chromosomes

In this study we used a novel technique to reveal both longitudinal and transverse differentiation within mammalian mitotic chromosomes. Structural changes in chromosomes that we term ‘differential decondensation’ were produced in cells that were first incubated in hypotonic medium (15% Hanks’ solution), then adapted to normotonic conditions and thereafter exposed to a second short hypotonic shock. Such a double hypotonic treatment (DHT) is not critical for cell viability, but considerably elongates the G2 phase of the cell cycle. Giemsa staining of differentially decondensed chromosomes corresponds to standard G-banding, but does not need the standard post-fixation treatment. Using ‘dynamic’ BrdU banding, we show that such ‘differential’ staining is a result of differential resistance of the R- and G-bands to DHT. Thus, early-replicating foci, markers of R-bands, are localized in the peripheral chromatin halo, whereas late-replicating foci, corresponding to G-bands, remain associated with the axial regions of chromatids. Remarkably, despite these major changes in the structure of the chromosomal bands, the replication foci still preserve their discrete structure.     

影像导航计算机辅助手术系统中的空间数据结构模型研究

影像导航计算机辅助手术系统（ICAS）是一种为术者提供术野周围重要解剖结构信息的辅助工具，可提高手术安全性和成功率。合理的空间数据结构模型是确保ICAS实现导航功能的关键因素之一。本研究提出了组合邻接表线索化八叉树模型（MALTO），并就基本操作的可实现性和实时性，分析比较了MALTO与4种常用模型的性能。研究结果表明：MALTO不但可以实现数据查找、搜索和计算等基本操作，且具有时间效率优势。因此，MALTO是适合于ICAS的空间数据结构模型。