维吾尔族饲鸽者肺IFN-r及IL-4 基因多态性研究

目的：探讨IFN-r(rs2069705)及IL-4(rs2070874)基因单核苷酸多态性与维吾尔族饲鸽者肺的关系。方法：根据纳入及排除标 准收集病例资料及血标本（总纳入92 例，其中患病组32 例，阴性对照组30 例，正常对照组30 例），对纳入者的全血标本进行 DNA提取，根据UCSC 数据库中SNP 位点附件的序列信息，利用MassARRAY技术平台设计引物、PCR扩增、SAP、单碱基延伸、 点样质谱检测IFN-r及IL-4 基因进行多态性分析，采用SPSS18.0 软件进行统计分析，基因型及等位基因分布频率的比较采用X2 检验。结果：IFN-酌(rs2069705) 基因存在CC、CT、TT 三种基因型，IL-4 (rs2070874) 基因存在CC、CT、TT 三种基因型，IFN-r (rs2069705) CC、CT、TT 基因型在患病组、未患病组、对照组中分布频数以及C、T 等位基因在各组中分布频率比较均无明显差异 （X2=2.607，P=0.626；X2=2.244，P=0.326）；并进行基因型分布频率的组间两两比较均无明显差异（X2=1.144，P=0.564；X2=0.534， P=0.766；X2=2.0，P=0.368）。IL-4(rs2070874)CC、CT、TT三种基因型在患病组、未患病组、对照组中分布频数以及C、T 等位基因在 各组中分布频率比较均无明显差异（X2=6.614，P=0.158；X2=5.408，P=0.067）；但进行基因型分布频率组间两两比较发现患病组与 未患病组中比较差异有统计学意义（X2=6.67，P=0.036）；患病组中纯合子TT数量较纯合子CC及杂合子CT数量相比较，纯合子 TT 发生PBL 的相对危险度OR（95%CI）分别为0.11（0.02 ~ 0.68）、0.16（0.03 ~ 0.79），P 值分别为0.018、0.025，差异有统计学意 义；纯合子CC 与杂合子CT 比较差异无统计学意义（P=0.402；P=0.134）。结论：IFN-r(rs2069727)基因多态性可能参与维吾尔族 PBL的发生发展，但未在PBL发病机制中起作用，需要加大样本量进一步证实。而IL-4(rs2070874)基因多态性可能参与维吾尔族 饲鸽者肺（Pigeon Breeder''s Lung , PBL）的发生发展，IL-4(rs2070874)的携带纯合子TT 可能是维吾尔族PBL 易感的一个危险因 素，可能会增加维吾尔族饲养鸽子者发生PBL的风险，需要增加样本量进一步验证。     

Sea Urchin Spines as a Model-System for Permeable, Light-Weight Ceramics with Graceful Failure Behavior. Part I. Mechanical Behavior of Sea Urchin Spines under Compression

The spines of pencil and lance urchins Heterocentrotus mammillatus and Phyllacanthus imperialis were studied as a modelof light-weight material with high impact resistance.The complex and variable skeleton construction ("stereom") of body andspines of sea urchins consists of highly porous Mg-bearing calcium carbonate.This basically brittle material with pronouncedsingle-crystal cleavage does not fracture by spontaneous catastrophic device failure but by graceful failure over the range of tensof millimeter of bulk compression instead.This was observed in bulk compression tests and blunt indentation experiments onregular,infiltrated and latex coated sea urchin spine segments.Microstructural characterization was carried out using X-raycomputer tomography,optical and scanning electron microscopy.The behavior is interpreted to result from the hierarchicstructure of sea urchin spines from the rnacroscale down to the nanoscale.Guidelines derived from this study see ceramics withlayered porosity as a possible biomimetic construction for appropriate applications.     

追溯山茱萸科植物的性状进化和生物地理学历史——方法选择的影响?

This study compares results on reconstructing the ancestral state of characters and ancestral areas of distribution in Cornaceae to gain insights into the impact of using different analytical methods. Ancestral character state reconstructions were compared among three methods (parsimony, maximum likelihood, and stochastic character mapping) using MESQUITE and a full Bayesian method in BAYESTRAITS and inferences of ancestral area distribution were compared between the parsimony-based dispersal-vicariance analysis (DIVA) and a newly developed maximum likelihood (ML) method. Results indicated that among the six inflorescence and fruit characters examined, "perfect" binary characters (no homoplasy, no polymorphism within terminals, and no missing data) are little affected by choice of method, while homoplasious characters and missing data are sensitive to methods used. Ancestral areas at deep nodes of the phylogeny are substantially different between DIVA and ML and strikingly different between analyses including and excluding fossils at three deepest nodes. These results, while raising caution in making conclusions on trait evolution and historical biogeography using conventional methods, demonstrate a limitation in our current understanding of character evolution and biogeography. The biogeographic history favored by the ML analyses including fossils suggested the origin and early radiation of Cornus likely occurred in the late Cretaceous and earliest Tertiary in Europe and intercontinental disjunctions in three lineages involved movements across the North Atlantic Land Bridge (BLB) in the early and mid Tertiary. This result is congruent with the role of NALB for post-Eocene migration and in connecting tropical floras in North America and Africa, and in eastern Asia and South America. However, alternative hypotheses with an origin in eastern Asia and early Trans-Beringia migrations of the genus cannot be ruled out.     

Combining molecular dynamics and docking simulations of the cytidine deaminase from Mycobacterium tuberculosis H37Rv

Cytidine Deaminase (CD) is an evolutionarily conserved enzyme that participates in the pyrimidine salvage pathway recycling cytidine and deoxycytidine into uridine and deoxyuridine, respectively. Here, our goal is to apply computational techniques in the pursuit of potential inhibitors of Mycobacterium tuberculosis CD (MtCDA) enzyme activity. Molecular docking simulation was applied to find the possible hit compounds. Molecular dynamics simulations were also carried out to investigate the physically relevant motions involved in the protein-ligand recognition process, aiming at providing estimates for free energy of binding. The proposed approach was capable of identifying a potential inhibitor, which was experimentally confirmed by IC₅₀ evaluation. Our findings open up the possibility to extend this protocol to different databases in order to find new potential inhibitors for promising targets based on a rational drug design process.