猪小肠抗菌肽对SPF鸡肠道黏膜免疫功能的影响

60只1日龄的SPF 鸡随机分为两组,来评价添加外源性抗菌肽对其肠道黏膜免疫功能的影响.结果表明:1)十二指肠、空肠和回肠内的上皮内淋巴细胞数量从第21日龄起,与对照组相比差异明显(p<0.05).2)自21日龄起,在抗菌肽处理组可以见到明显的肥大细胞,而在对照组少见(p<0.05).3)抗菌肽的处理能显著增加各段肠道内杯状细胞的数量(p<0.05).4)使用抗菌肽处理后,能提高各段肠道的sIgA的表达.添加外源性的抗菌物质,能显著提高SPF鸡的肠道黏膜免疫参数,并且有助于进一步深入了解抗菌肽对肠道黏膜免疫的调控机制.     

肥大细胞与针刺信息传递机制研究

我们过去的研究表明,在大鼠皮肤中存在多条纵贯全身的交感物质分布线,在这些线上的毛囊立毛肌上分布着极其丰富的交感肾上腺素能神经末梢[1-2].大鼠全身剃毛后,新生的毛首先在某些部位优先生长出来,形成新生毛线环路系统[1,3-4].针刺或皮内注射药物后会产生立毛运动线,立毛传递线下的皮肤显著充血.这种传递可以在去中枢支配的情况下,独立地沿着交感物质分布线或毛线环路传递,属于邻近毛囊间的连锁或接力传递过程,依赖于通过局部真皮网状层和皮下组织中的神经轴突反射[1,5].     

半胱胺对鸡十二指肠中肥大细胞数量的影响

84只1日龄小公鸡,分为四组,分别为对照组、新城疫弱毒疫苗免疫组(ND组)、饲喂半胱胺的试验组(CS组)以及饲喂半胱胺后,再用新城疫弱毒疫苗进行消化道粘膜的试验组(CN组).应用甲苯胺蓝染色技术研究了十二指肠中肥大细胞数量的变化.结果显示:新城疫疫苗首免后第三周,CN组十二指肠中肥大细胞数量比ND组明显增加(P0.01);首免后第五周,各试验组十二指肠中肥大细胞的数量均比对照组多,尤其是CN组,可能因为个体差异较大,各组间并无显著差异.本试验的结果提示,肥大细胞的数量可能反映了消化道粘膜的免疫水平.     

钢屋架桅杆吊装法施工技术研究

钢结构往往有多种可供选择的施工方法,每一种施工方法都有其自身的特点和不同的适用范围。文章针对某体育中心篮球馆梭形钢桁架结构的施工特点,介绍了工程中钢桁架拼装,龙门桅杆制作,以及吊装过程中的关键技术,在场地狭小的客观条件下为钢桁架安装提供一项成功经验。     

Bruton酪氨酸激酶Btk的生物学特性研究进展

酪氨酸激酶Btk是非受体酪氨酸家族的成员,它由PH结构域、TH结构域、SH3结构域、SH2结构域和催化结构域5部分组成.Btk参与多种信号通路,对细胞的增殖、分化和凋亡起着重要的调控作用.Btk的突变可导致X连锁无丙种球蛋白血症,一直以来都是研究热点.笔者将围绕Btk的结构、功能、X连锁无丙种球蛋白血症的临床表现等方面的内容加以综述,着重探讨Btk参与B细胞信号通路、TLR信号通路和肥大细胞脱颗粒等过程的具体机制.     

舰船封闭式桅杆雷达隐身优化分析

桅杆作为重要的雷达反射源,直接影响到舰船的整体隐身性能,对其进行外形雷达隐身优化非常有意义.在特定的雷达探测条件下,以某封闭式八边形桅杆为例,利用自适应遗传算法,分别以威胁区域内的雷达散射截面(RCS)最大值、平均值,被监测平均概率以及大于RCS临界值的概率4种评价指标为目标函数进行桅杆形状的特征参数优化,并对不同指标的优化结果进行对比分析.优化后桅杆的隐身性能均有明显提升,4种优化结果所对应的RCS面积分布具有一定的相似性,同时结果也表明针对特征角度的RCS优化是无效的.     

A model of calcium signaling and degranulation dynamics induced by laser irradiation in mast cells

Recent experiments show that calcium signaling and degranulation dynamics induced by low power laser irradiation in mast cells must rely on extracellular Ca^2＋ influx. An analytical expression of Ca^2＋ flux through TRPV4 cation channel in response to interaction of laser photon energy and extracellular Ca^2＋ is deduced, and a model characterizing dynamics of calcium signaling and degranulation activated by laser irradiation in mast cells is established. The model indicates that the characteristics of calcium signaling and degranulation dynamics are determined by interaction between laser photon energy and Ca^2＋ influx. Extracellular Ca^2＋ concentration is so high that even small photon energy can activate mast cells, thus avoiding the possible injury caused by laser irradiation with shorter wavelengths. The model predicts that there exists a narrow parameter domain of photon energy and extracellular Ca^2＋ concentration of which results in cytosolic Ca^2＋ limit cycle oscillations, and shows that PKC activity is in direct proportion to the frequency of Ca^2＋ oscillations. With the model it is found that sustained and stable maximum plateau of cytosolic Ca^2＋ concentration can get optimal degranulation rate. Furthermore, the idea of introducing the realistic physical energy into model is applicable to modeling other physical signal transduction systems.     

Hydrodynamics numerical investigation of hoistable masts for underwater vehicles

Using the unsteady incompressible Navier-Stokes equation as the governing equation, the large eddy simulation (LES) model is implemented to investigate the shedding of vortices, the flow pattern of turbulence, the unsteady pressure fluctuation and the time history of the lift coefficient and drag coefficient of hoistable masts with various mast shapes and various arrangements in this paper. Combining the FFT, combined time-frequency transform and wavelet power spectrum analysis, the characteristics of unsteady pressure can be obtained in both time and frequency domain. It shows that the main frequency of pressure fluctuation is near the frequency of vortex shedding in time domain using the FFT method. It can be inferred from the combined time-frequency transform that the unsteady pressure fluctuation has obviously the peak value and the second peak value in time domain. It could indicate that the fluctuation power varies from the fluctuation frequency through the power spectrum analysis. By the data analysis, it shows that the vortex shedding is the dominant cause of the periodically pressure fluctuation. And the interaction pattern of wake and interplay between wake and the walls of masts under different arrangements are also discussed in this paper.     

地基土性质对石油钻机井架动力特性的影响

对石油钻机井架的振动进行了研究。强调指出 ,在这种振动分析中忽略底座与地基对井架振动的耦合作用 ,将导致工程上不允许的误差。在此基础上着重研究了地基土力学性质对井架动力特性的影响。由实际算例确定 ,在岩土及碎石土和亚粘土两种不同地基上 ,井架系统的前四阶固有频率将有高达 2 6 %的波动。首次确定了由于地基土力学性质的波动而导致的井架振动系统随机性的程度 ,它对井架的动力设计和正确使用是有意义的     

“П”型井架背部杆联接刚度对其动力特性的影响

以一实际井架（ZJ20）作为算例,探讨了背部腹杆联接刚度对“П”型井架系统动力特性的影响,研究了背部腹杆节点在空间铰、柱形铰和刚性三种理想联接方式下井架系统的动力特性,给出了前6阶模态和自振频率。揭示出当背部杆节点在空间与刚性联接两种极端情况之间变化时,井架系统前6阶自振频率可发生27％－48％的对其均值的偏离。