Homologies in both primary and secondary structure between nuclear envelope and intermediate filament proteins

The A, B and C lamins are the major proteins of the nuclear envelope. The complete nucleotide sequence of the coding region of the A and C lamins shows that these proteins are identical except for their carboxy termini. The most prominent structural feature of both lamins is an alpha-helical region of repeating heptads of amino acids that shows striking homology with the entire family of cytoplasmic intermediate filament proteins. These features suggest that the nuclear envelope is made up of a network of coiled-coil polymers.     

家兔晶状体蛋白质含量的测定

本文采用微量凯氏定氮法测定了家兔晶状体总蛋白和水溶性蛋白的百分含量，结果分别为３３８．１±５０．１ｍｇｇ－１和３０８．９±６３．２ｍｇｇ－１，晶状体水溶性蛋白含量约占晶状体总蛋白含量的９１．４％，这一结果对研究家兔晶状体生理生化变化具有一定的参考价值     

Biocompatibility of bio-Mg-Zn alloy within bone with heart, liver, kidney and spleen

A magnesium-zinc alloy rod was implanted into the marrow cavity of the distal femur in New Zealand rabbits. The femur with the implanted alloy was compared with the contralateral femur in which a bone tunnel without implant was formed as a control. Degradation of the magnesium-zinc alloy was analyzed via X-ray, scanning electron microscopy, and element energy spectrum analysis. Serum magnesium, liver and kidney function tests, and myocardial enzymes were measured. Heart, liver, kidney and spleen were sectioned for pathological analysis, and the effects of the implanted material on the histology and function of important organs were analyzed. Magnesium-zinc alloy was resorbed from the bone marrow cavity of the femur; 87% of the alloy was degraded within 14 weeks after the surgery. There were no significant differences in serum magnesium, liver or kidney function tests, or myocardial enzymes before the surgery and after degradation of the magnesium-zinc alloy. Histology of the heart, liver, kidney, and spleen did not change. This study demonstrated that magnesium-zinc alloy can be resorbed in bone, and that the degradation products have good biocompatibility with heart, liver, kidney, and spleen. Supported by the National Natural Science Foundation of China (Grant No. 30772182, and the Medical-Industial intersect study in Shanghai Jiaotong University (Grant No. YG2007MS26)     

Markov过程一致指数收敛速度与谱隙的关系

讨论了一般状态空间转移概率函数一致收敛速度α与谱隙λ的关系。用比可数状态空间较多的技巧得到同可数状态空间类似的结果，进而得到了谱隙λ的一个下界估计式。     

X-ray analysis of beta B2-crystallin and evolution of oligomeric lens proteins

The beta, gamma-crystallins form a class of homologous proteins in the eye lens. Each gamma-crystallin comprises four topologically equivalent, Greek key motifs; pairs of motifs are organized around a local dyad to give domains and two similar domains are in turn related by a further local dyad. Sequence comparisons and model building predicted that hetero-oligomeric beta-crystallins also had internally quadruplicated subunits, but with extensions at the N and C termini, indicating that beta, gamma-crystallins evolved in two duplication steps from an ancestral protein folded as a Greek key. We report here the X-ray analysis at 2.1 A resolution of beta B2-crystallin homodimer which shows that the connecting peptide is extended and the two domains separated in a way quite unlike gamma-crystallin. Domain interactions analogous to those within monomeric gamma-crystallin are intermolecular and related by a crystallographic dyad in the beta B2-crystallin dimer. This shows how oligomers can evolve by conserving an interface rather than connectivity. A further interaction between dimers suggests a model for more complex aggregates of beta-crystallin in the lens.     

广州城乡居民收入差距现状分析

在对广州城乡居民收入进行纵向和横向对比,以及剖析广州城乡居民收入来源和结构后,结合课题组的调研结果得出了影响广州城乡居民收入变化的主要因素:居民收入所占比重偏低、工资性收入差距较大、转移性收入差距较大和区域经济发展不平衡.有针对性地提出了缩小广州城乡居民收入差距的对策.     

An organic junction between the vein and membrane of the dragonfly wing

A dragonfly wing consists of membranes and both longitudinal and cross veins. We observed the microstructure cross-section at several locations in the dragonfly wing using environmental scanning electron microscopy (ESEM). The organic nature of the junction between the vein and the membrane was clearly identifiable. The membrane was divided into two layers, the upper epidermis and the lower epidermis. These layers extend around the sandwich structure vein, and combine with the adjacent membrane at a symmetrical location along the vein. Thus, we defined this as an organic junction between the vein and the membranes. The organic junction is able to form a tight corrugation angle, which dramatically increases both the warping rigidity and the strength of the wing, but not the torsional rigidity. The torsional deformation is primarily controlled by the microstructure of the longitudinal veins, and is based on the relative rotation angle between the epidermal layer and the inner layer of the vein that forms the zigzag section.