褪黑素的生物合成及对繁殖性能的影响

褪黑素是一种广泛存在于动物体内的激素,不仅能够调节动物昼夜节律,还能够从多方面影响动物的繁殖性能,对于季节性繁殖动物,褪黑素根据日照时长的变化表现出抑制或促进繁殖性能的作用。对于幼年动物,褪黑素表现出抑制发情的作用,体成熟后则表现促进发情的作用。褪黑素主要通过下丘脑-垂体-性腺轴调控动物繁殖活动,除此之外,褪黑素还能够直接作用于生殖系统甚至早期胚胎,通过提高组织及细胞抗炎及抗氧化功能来改善动物繁殖性能。目前,褪黑素能够用于治疗精神疾病及炎症、促进畜禽繁殖和调节昼夜节律,是相关研究领域的热门话题。本文详细描述了褪黑素的生物合成以及分泌调控,并结合褪黑素的生理功能,阐述了对动物繁殖性能以及辅助生殖的影响。     

小麦饲料中添加木聚糖酶对高原型藏羊胃肠道发育的影响

旨在分析小麦粉中添加木聚糖酶(xylanase, Xyl)对藏羊羔羊胃肠道发育的影响。选择同质性良好的2～3月龄高原型藏羊公羔60只,随机分为两组,每组30只,各组内设置5个重复。对照组(Control group)饲喂不含木聚糖酶的日粮,试验组(Test group)饲喂含0.2%木聚糖酶的日粮,试验分为预饲期10 d和正试期90 d。饲养试验结束时,两组各随机选取5只羔羊进行屠宰,采集消化道组织置于多聚甲醛固定,并收集血液、瘤胃和空肠内容物。结果显示：1)与对照组相比,试验组瘤胃的角质层厚度、颗粒层厚度,瓣胃的乳头长度、乳头宽度、角质层厚度、颗粒层厚度,皱胃的黏膜厚度以及十二指肠的肌层厚度,空肠的绒毛高度、黏膜厚度,回肠的肌层厚度显著提高(P<0.05);2)对照组瘤胃和血清的LPS含量显著高于试验组(P<0.05);3)相较于对照组,试验组瘤胃的糜蛋白酶、胰蛋白酶、脂肪酶活性以及空肠的糜蛋白酶、α-淀粉酶活性显著提高(P<0.05);4)试验组瘤胃的总抗氧化能力水平、谷胱甘肽过氧化物酶及过氧化氢酶活性以及空肠的总抗氧化能力水平、谷胱甘肽过氧化物酶、超氧化物歧化酶...     

PA-X基因的长度变化对H3N2犬流感病毒复制能力和致病性的影响

H3N2犬流感病毒(canine influenza virus, CIV)已在中国多地的犬群中流行,是禽流感跨宿主感染并形成新分支的近期案例。研究表明,PA-X基因与甲型流感病毒适应新宿主的能力相关,且其长度能够影响甲型流感病毒的复制及致病能力。为了解PA-X基因的长度变化对H3N2 CIV复制能力及致病力的影响,本研究利用H3N2 CIV的8质粒操作系统,拯救了三株重组H3N2 CIV毒株：PA-X基因表达大小为232个氨基酸多肽的亲本病毒CIV＿PA-X＿232;对PA编码区第191、192位氨基酸的密码子进行改造,PA-X基因不表达蛋白的重组病毒CIV＿PA-X＿Knock;对PA+1编码区第232位氨基酸进行突变,PA-X基因表达大小为252个氨基酸多肽的重组病毒CIV＿PA-X＿252。通过比较3株重组病毒的聚合酶活性,在MDCK细胞中的复制效率及对小鼠致病性的差异,来评价表达不同长度的PA-X基因对H3N2 CIV的影响。结果显示,CIV＿PA-X＿252和CIV＿PA-X＿Knock的聚合酶活性显著(P<0.05)高于CIV＿PA-X＿232,且CIV＿PA-X＿...     

植物开花光周期反应的分子调控机制

植物开花时间受到日照长短季节性变化的调节,拟南芥和水稻中与光周期反应相关基因的分离,使人们得以认识植物开花光周期反应的分子调控机制。植物感知日照长短的变化主要由CONSTANS(CO)基因的表达所控制。CO能够将光信号与生物钟信号整合,调节开花基因FLOWERING LOCUS T(FT)的表达,并最终控制植物的开花时间。本文对这一研究的最新进展进行了综述。     

Analysis on Competition from the View of Law and Economics and the Inspiration

The establishment of the competition legal system is the response to the social and economical reality. The perfection of the competition legal system needs the support of economic theory. Therefore, analyzing the competition from the law and economic perspective is propitious to perfect the regulation of competition in the law system constantly, guarantee and promote competition, and thus to establish and maintain reasonable and efficient competition order, promote market-economy developing prosperously and harmoniously. The paper uses the study methods of economical and comparative analyze, explore the sorts of competition and their effectiveness, believe that the perfection of the competition legal system should firstly definite that its adjust object is the effective competition with monopoly factor; though the exemption of competition cant be avoid, it continuously appears shrinking trend. The competition legal system will play a more important role in the economical life.     

Clustering Analysis for Time Feature of User Power Consumption Based on Structural Self-adaptation ANN

In view of the important effect of clustering analysis in data mining, the clustering rules and its curve are studied to solve the problem of determining clustering number. A kind of self-adaptation clustering ANN is presented based on SOFM ANN, which can automatically determine the clustering number. Based on practical sales data, the time feature analysis of power user consumption are carried out by using the self-adaptation clustering ANN, whose conclusion has the important referenced values for adjusting power price correspondingly and arranging power producing reasonably.     

A Method for State Diagnosis of Grounding Grid

This paper discuses the method with which the corrosion of the grounding grid can be diagnosed .A grounding grid can handled as a circuit network. With the application of circuit network graph theory and the fault diagnosis theory of analog circuit and optimization, the fault diagnosis equations can be set up. This equations is figured out by Matlab, and the corrosion status of the grounding grid can be deduced from the result.     

Visualization of the FEM Analysis Data of 3D on the Cut Plane

The colored patterns on arbitrary cut plane is an important method in 3D data-field visualization of finite element.By using the technology of the Object-Oriented Programming and the method of scan-line,the colored patterns on arbitrary cut plane are given.The example by the OPENGL of Visual C++ R6 can support the theory satisfactorily.     

Exploration of the Sustainability Design for Industrial Building

Within the domain of comprehensive architecture, the general instructive principles for the sustainability design are applicable to that of industrial building. Based on the analysis of excellent precedents, in this paper, some useful experiences are summarized. It is pointed out that the sustainability design is feasible and should be compulsive for industrial building.