茶尺蠖普通气味结合蛋白基因片段cDNA的克隆与序列分析

根据同源性设计简并性引物,采用RT-PCR方法扩增出了茶尺蠖普通气味结合蛋白GOBP1和GOBP2的基因cDNA片段,大小分别为415 bp和352 bp.测序结果在NCBI中经BLAST搜索,结果表明,两者与已报道的鳞翅目昆虫的气味结合蛋白基因片段或全长的同源性分别为79%~83%和78%~90%.根据两个核苷酸片段推导出的氨基酸残基数分别为138个和117个,均具有6个保守的半胱氨酸位点,符合典型的气味结合蛋白的特点.经BLAST搜索,与其他鳞翅目昆虫GOBP1和GOBP2氨基酸序列的同源性分别为62%~82%和76%~88%.     

6类布线系统的施工与安装

美国通信工业协会TIA早在2002年6月就正式通过了6类布线标准（ANSI／TIA／EIA 568B．2-1-2002）,该标准也被国际标准化组织（ISO）批准,标准号为ISO 11801-2002。标准规定6类布线系统必须向下兼容3类、5类、超5类布线产品,同时必须满足混合使用的要求。在标准通过6年多的今天,正是6类布线系统迎来普及应用的时候。目前非常多的新项目正用6类布线系统来取代超5类。     

基于LabWindows/CVI的工程机械振动测试与分析系统

本文介绍了一个利用虚拟仪器技术开发的工程机械振动测试与分析系统.系统以WBK14信号调理模块、WBKS12数据采集模块和计算机为主控平台,利用虚拟仪器开发软件LabWindows/CVI7.0与高级信号分析软件包等,实现对工程机械整机及各部件性能的多功能检测、分析、处理和显示存储,满足对测试过程高精度、自动化、智能化等各项测试要求.     

青岛和大连海区海带(Laminaria japonica)外生细菌的16S rRNA基因序列分析

从采集自青岛和大连的大型褐藻海带(Laminaria japonica)表面分离到22株革兰氏阴性海洋细菌。根据16SrRNA基因序列分析结果,将其分别鉴定为假交替单胞菌(Pseudoalteromonas,Cobetia)菌,嗜冷单胞菌(Psychromonas),交替单胞菌(Alteromonas),产碱杆菌(Alcaligens)和海杆菌(Marinobacter)。其中假交替单胞菌在两地样品中占据绝对优势,但每个产地的假交替单胞菌不能单独聚类在一起,不同海区的海带表面存在遗传关系非常接近的菌株。假交替单胞菌之外的其他菌株于两地样品之间存在种或属水平上的差异。本文结果提示外生细菌的种类既与环境相关,又受宿主的状况影响。对8株受试菌株的拮抗实验结果显示了外生细菌在寻找新型抗生素方面的潜力。     

尼龙6/POE/粘土纳米复合材料的形态、结构及性能研究

采用熔融方法制备了PA 6/POE/粘土纳米复合材料.PA 6/POE/粘土纳米复合材料具有良好的力学性能,其缺口冲击强度比PA 6有显著提高.研究结果表明,有机粘土剥离于PA 6基体中,POE相以岛状结构均匀分散于PA 6基体中;PA 6/POE/粘土纳米复合材料的储能模量比PA 6的低,并且随着有机粘土含量的增加而降低.PA 6/POE/粘土纳米复合材料的玻璃化转变温度(Tg)随着粘土含量的增加而升高,具有良好的热稳定性.     

The structure of latherin,a surfactant allergen protein from horse sweat and saliva

Latherin is a highly surface-active allergen protein found in the sweat and saliva of horses and other equids. Its surfactant activity is intrinsic to the protein in its native form, and is manifest without associated lipids or glycosylation. Latherin probably functions as a wetting agent in evaporative cooling in horses, but it may also assist in mastication of fibrous food as well as inhibition of microbial biofilms. It is a member of the PLUNC family of proteins abundant in the oral cavity and saliva of mammals, one of which has also been shown to be a surfactant and capable of disrupting microbial biofilms. How these proteins work as surfactants while remaining soluble and cell membrane-compatible is not known. Nor have their structures previously been reported. We have used protein nuclear magnetic resonance spectroscopy to determine the conformation and dynamics of latherin in aqueous solution. The protein is a monomer in solution with a slightly curved cylindrical structure exhibiting a ‘super-roll’ motif comprising a four-stranded anti-parallel β-sheet and two opposing α-helices which twist along the long axis of the cylinder. One end of the molecule has prominent, flexible loops that contain a number of apolar amino acid side chains. This, together with previous biophysical observations, leads us to a plausible mechanism for surfactant activity in which the molecule is first localized to the non-polar interface via these loops, and then unfolds and flattens to expose its hydrophobic interior to the air or non-polar surface. Intrinsically surface-active proteins are relatively rare in nature, and this is the first structure of such a protein from mammals to be reported. Both its conformation and proposed method of action are different from other, non-mammalian surfactant proteins investigated so far.     

Synthesis and characterization of Bi2MoO6/MIL-101(Fe) as a novel composite with enhanced photocatalytic performance: Effect of water matrix and reaction mechanism

The integration of Bi₂MoO₆ with MIL-101(Fe) as a novel structure enhanced photocatalytic activity for RhB degradation. Bi₂MoO₆/MIL-101(Fe) composites were synthesized via the solvothermal procedure and characterized by XRD, EDX, FE-SEM, TEM, FT-IR, BET, TGA, UV–vis DRS, and PL. The optimal molar ratio Bi₂MoO₆:MIL-101(Fe) equal to 1:1 showed better photocatalytic activity than Bi₂MoO₆ and MIL-101(Fe) and other heterostructure composites. The effect of pH (5–9), reaction time (60–120 min), catalyst concentration (0.1–0.5 g/L), and dye concentration (10–20 ppm) were investigated on the removal performance of RhB by using central composite face-centered (CCF). In the optimal process factors where the [Catalyst]:0.4 g/L, [RhB]:20 ppm, pH: 6.5, irradiation time: 120 min, the RhB and TOC removal efficiency were 85% and 84.2%, respectively. The holes and superoxide radicals played a major role in the degradation of RhB. The addition of salt (NaCl, Na₂SO₄, and NaHCO₃) at different concentrations (100, 200, 400, and 800 ppm) revealed that the salts have an inhibitory role in the photocatalytic performance. At low concentrations of 100 ppm, the salts had a negative effect on removal efficiency (k_{Pure water} = 0.0155 min^?1, k_NaCl = 0.0075 min^?1, k_Na2SO4 = 0.0132 min^?1, k_NaHCO3 = 0.006 min^?1). Increasing the salt concentration to 800 ppm caused improved efficiency for NaCl (k_NaCl = 0.0141 min^?1), while for Na₂SO₄ this trend was decreasing (k_Na2SO4 = 0.011 min^?1), and for NaHCO₃ sharply diminished (k_NaHCO3 = 0.0026 min^?1).