阳泉市省道214阳泉过境公路李家庄河防洪评价研究

文章以双拱涵洞穿越省道214阳泉过境公路防洪影响评价为例,对涵洞的过水能力作了系统分析和探讨,论述了改建后的涵洞对50年一遇的洪水能顺利通过,并给出了防治措施。     

金刚砂楼地面的施工方法与质量控制

某大型仓库工程设计采用金刚砂楼地面,为确保施工质量,施工时需认真做好各项准备工作,严格根据气候、温度、砂浆配合比等因素控制好金刚砂撒布的时间.     

中医耳鼻喉科中文名词术语选词、定名与释义规范表述

中医耳鼻喉科中文名词术语规范与审定工作作为中医临床术语规范与审定工作中的一环,遵循中医临床术语规范与审定工作的普遍规律,同时又有着自身的特点。文章介绍了中医耳鼻喉科中文名词术语的选词、定名工作和注释的规范表述方法等,以期为中医临床各科术语规范与审定方法的探讨提供借鉴和参考。     

Genome sequence and analysis of the tuber crop potato

Potato (Solanum tuberosum L.) is the world's most important non-grain food crop and is central to global food security. It is clonally propagated, highly heterozygous, autotetraploid, and suffers acute inbreeding depression. Here we use a homozygous doubled-monoploid potato clone to sequence and assemble 86% of the 844-megabase genome. We predict 39,031 protein-coding genes and present evidence for at least two genome duplication events indicative of a palaeopolyploid origin. As the first genome sequence of an asterid, the potato genome reveals 2,642 genes specific to this large angiosperm clade. We also sequenced a heterozygous diploid clone and show that gene presence/absence variants and other potentially deleterious mutations occur frequently and are a likely cause of inbreeding depression. Gene family expansion, tissue-specific expression and recruitment of genes to new pathways contributed to the evolution of tuber development. The potato genome sequence provides a platform for genetic improvement of this vital crop.     

Oxysterols direct immune cell migration via EBI2

Epstein-Barr virus-induced gene 2 (EBI2, also known as GPR183) is a G-protein-coupled receptor that is required for humoral immune responses; polymorphisms in the receptor have been associated with inflammatory autoimmune diseases. The natural ligand for EBI2 has been unknown. Here we describe the identification of 7α,25-dihydroxycholesterol (also called 7α,25-OHC or 5-cholesten-3β,7α,25-triol) as a potent and selective agonist of EBI2. Functional activation of human EBI2 by 7α,25-OHC and closely related oxysterols was verified by monitoring second messenger readouts and saturable, high-affinity radioligand binding. Furthermore, we find that 7α,25-OHC and closely related oxysterols act as chemoattractants for immune cells expressing EBI2 by directing cell migration in vitro and in vivo. A critical enzyme required for the generation of 7α,25-OHC is cholesterol 25-hydroxylase (CH25H). Similar to EBI2 receptor knockout mice, mice deficient in CH25H fail to position activated B cells within the spleen to the outer follicle and mount a reduced plasma cell response after an immune challenge. This demonstrates that CH25H generates EBI2 biological activity in vivo and indicates that the EBI2-oxysterol signalling pathway has an important role in the adaptive immune response.     

S-nitrosylation of NADPH oxidase regulates cell death in plant immunity

Changes in redox status are a conspicuous feature of immune responses in a variety of eukaryotes, but the associated signalling mechanisms are not well understood. In plants, attempted microbial infection triggers the rapid synthesis of nitric oxide and a parallel accumulation of reactive oxygen intermediates, the latter generated by NADPH oxidases related to those responsible for the pathogen-activated respiratory burst in phagocytes. Both nitric oxide and reactive oxygen intermediates have been implicated in controlling the hypersensitive response, a programmed execution of plant cells at sites of attempted infection. However, the molecular mechanisms that underpin their function and coordinate their synthesis are unknown. Here we show genetic evidence that increases in cysteine thiols modified using nitric oxide, termed S-nitrosothiols, facilitate the hypersensitive response in the absence of the cell death agonist salicylic acid and the synthesis of reactive oxygen intermediates. Surprisingly, when concentrations of S-nitrosothiols were high, nitric oxide function also governed a negative feedback loop limiting the hypersensitive response, mediated by S-nitrosylation of the NADPH oxidase, AtRBOHD, at Cys 890, abolishing its ability to synthesize reactive oxygen intermediates. Accordingly, mutation of Cys 890 compromised S-nitrosothiol-mediated control of AtRBOHD activity, perturbing the magnitude of cell death development. This cysteine is evolutionarily conserved and specifically S-nitrosylated in both human and fly NADPH oxidase, suggesting that this mechanism may govern immune responses in both plants and animals.     

扎龙湿地土地覆盖变化分析

利用遥感与地理信息系统技术分析1979-2006年间的一系列卫星影像,研究了扎龙湿地土地覆盖的数量变化,速度变化,趋势变化及引起这些变化的水的空间分布的变化．     

基于MEMS的压电厚膜谐振梁能量收集器的研究

在谐振梁能量收集器中PZT膜材料的制备起着至关重要的作用,复合结构的锆钛酸铅(PZT)厚膜采用溶胶-凝胶方法旋涂在硅基的Au/Cr/SiO2/Si结构衬底的制备方法,主要因为溶胶-凝胶制备方法简单,成本低适合于集成制作.改进PZT组分和和0-3混合法及复合结构的Au/Cr/SiO2/Si衬底,使制备的PZT厚膜避免了厚...     

三亚景区游客游憩动机初探

运用因子分析方法研究了三亚景区游客的游憩动机,确立了社会交往与身体享受、逃避日常环境、增长见识、心灵享受四个动机因子,进一步运用聚类分析方法将游客分为求知型、逃避型、社交与享受型三个类别,在此基础上分析了三种不同游憩动机旅游者在人口统计特征及游憩行为上的差异.结果显示:三类旅游者在性别、年龄、受教育程度上等社会人口特征上都无显著差异,仅在人均月收入方面差异显著,收入者较高者出游多出于社交原因或者身体享受的动机,而低收入者的动机多为增长知识.     

一类恒化器模型解的稳定性

讨论一类含1个食饵和1个捕食者种群的恒化器模型的整体解.分析该模型解的一致有界性,运用线性化方法和Lyapunov函数方法研究该模型非负平衡点的局部渐近稳定性和全局渐近稳定性.