含CBS结构域的小麦TaCDCP1基因的克隆及其表达分析

利用电子克隆和RT-PCR技术,在本实验室前期构建的非亲和互作的SSH文库基础上,从条锈菌侵染的小麦水原11叶片中首次分离出一个含CBS结构域蛋白的基因,暂命名为TaCDCP1(Triticum aestivum CBS domain containing protein 1)。TaCDCP1包含一个完整的654 bp的开放阅读框,编码217个氨基酸。推测该基因拟编码的蛋白具有2个CBS保守结构域,不含跨膜区且无信号肽,定位在叶绿体基质内;经过同源比对,小麦TaCDCP1氨基酸序列与大麦、水稻和玉米等的同源序列的相似性较高;该基因表达量在小麦叶中显著高于在根和茎中;在小麦与条锈菌的非亲和、亲和组合中,TaCDCP1基因均受到条锈菌诱导,分别在接种后18 h和96 h达到表达高峰,非亲和组合表达量在侵染前期(接种后18~48 h)高于亲和组合,而在侵染后期(接种后96~120 h)低于亲和组合;外源植物激素脱落酸诱导该基因上调表达,苄基腺嘌呤,乙烯,赤霉素,茉莉酸甲酯和水杨酸处理后其表达量在不同程度上受到抑制;TaCDCP1在低温和干旱条件下表达量上升,在机械伤害和高盐处理下表达量无明显差异。表明TaCDCP1可能通过脱落酸等信号途径参与小麦对条锈菌的防御反应,同时参与低温和干旱环境下的信号转导途径。这些结果对于明确CBS结构域的功能以及CBS结构域蛋白尤其是TaCDCP1在小麦与条锈菌互作中的作用奠定了基础。     

CBS对食品卫生学教学效果的影响

食品卫生学是食品质量与安全专业和食品营养专业学生的一门重要专业课程,也是一门实用性非常强的学科。为了使学生更好地将理论与实际相结合,在教学中引入了CBS教学法。结果显示,该方法具有较好的提高食品卫生学教学效果的作用,是一种值得推广的有效教学模式。     

巧克力中可可脂与代可可脂的GC-MS分析与营养比较

根据可可脂与代可可脂中脂肪酸组成的不同,采用气相色谱-质谱联用法(GC-MS)分析巧克力中代可可脂(CBS)及可可脂(CB)的含量。从脂肪酸组成角度比较巧克力与代可可脂巧克力的营养价值。     

大炎肽在胰腺中相互作用蛋白的纯化鉴定

为研究大炎肽影响胰腺β细胞的机制,将大炎肽偶联到CNBr活化的Sepharose 4B亲和层析介质上,利用亲和纯化的方法垂钓其在胰腺组织中的相互作用蛋白,并对纯化蛋白进行胰蛋白酶水解,测定水解片段的分子质量和其中2个片段的氨基酸序列,在MASCOT数据库中检索,鉴定此蛋白为胱硫醚β-合成酶,结果提示大炎肽可能通过结合胱...     

Properties of thermoplastic composites with cotton and guayule biomass residues as fiber fillers

This study was conducted to evaluate the suitability of using residual plant fibers from agricultural waste streams as reinforcement in thermoplastic composites. Three groups of plant fibers evaluated included cotton burrs, sticks and linters from cotton gin waste (CGW), guayule whole plant, and guayule bagasse. The plant fibers were characterized for physical (bulk density and particle size distribution) and chemical properties (ash, lignin and cellulose contents). A laboratory experiment was designed with five fiber filler treatments, namely control (oak wood fiber as the filler - OWF), cotton burr and sticks (CBS), CBS with 2% (by weight) second cut linters (CBL), CBS with 30% (by weight) guayule whole plant (CGP), and CBS with 30% (by weight) guayule bagasse (CGB). The composite samples were manufactured with 50% of fiber filler, 40% of virgin high-density polyethylene (HDPE), and 10% other additives by weight. The samples were extruded to approximately 32 × 7 mm cross-sectional profiles, and tested for physico-mechanical properties. The CBS and CBL had considerably lower bulk density than the other fibers. Cotton linters had the highest α-cellulose (66.6%), and lowest hemicellulose (15.8%) and lignin (10.5%) of all fibers tested. Guayule whole plant had the lowest α-cellulose and highest ash content. Both CBS and guayule bagasse contained α-cellulose comparable to OWF, but slightly lower hemicellulose. Evaluation of composite samples made from the five fiber treatments indicated that fibers from cotton gin byproducts and guayule byproducts reduced the specific gravity of the composites significantly. However, the CBS and CBL samples exhibited high water absorption and thickness swelling, but the addition of guayule bagasse reduced both properties to similar levels as the wood fiber. The CGP exhibited significantly lower coefficient of thermal expansion. Composite samples with the five different fiber fillers showed similar hardness and nail holding capacity, yet oak fibers imparted superior strength and modulus under flexure and compression with the exception of the compressive modulus of CGB composites. In general, both cotton ginning and guayule processing byproducts hold great potential as fiber fillers in thermoplastic composites.     

内源性气体信号分子H_2S研究进展

H2S是继NO和CO之后发现的第3种内源性气体信号分子.在机体内主要由胱硫醚-β-合酶(cBS)和胱硫醚-γ-裂解酶(CSE)催化产生,广泛分布于机体各个部位.HzS在体内参与舒张血管、抑制平滑肌增殖等各种生理过程.并且在高血压、内毒素性休克、手术创伤等各种疾病病理过程中发挥着重要的作用.论文就H2S的生成、代谢、生理作用及其与疾病的关系等方面做了综述.     

Succession of mosses,liverworts and ferns on coarse woody debris,in relation to forest age and log decay in Tasmanian wet eucalypt forest

In managed forest landscapes, understanding successional processes is critical to management for sustainable biodiversity. Coarse woody debris is a key substrate for forest biodiversity, particularly because it undergoes complex succession reflecting the effects of changes in both forest structure and substrate characteristics. The present study used a chronosequence approach to investigate succession of mosses, liverworts and ferns on coarse woody debris following clearfell, burn, sow native forest silviculture in wet eucalypt forest in Tasmania, focussing on discriminating between the effects of forest age and log decay. It also compared successional processes following wildfire with those following clearfell, burn, sow silviculture. Forest regenerating after the latter form of regeneration showed clear ecological succession up to 43 years (the limit of available sites), characterised by increasing diversity and cover, and clearly delineated specialisation among species with regard to successional stage. Analyses of subsets of the full data-set indicated that the effects of forest age dominated this succession, with minimal effects of substrate change independent of forest age. Analysis of within forest microenvironments were consistent with the inference that microenvironmental changes related to forest age drive major successional changes in these forests. Comparative analysis indicated similarity between successional states in post-wildfire and post- clearfell, burn, sow regeneration after 43 years for logs of the same decay stages, and continuing succession on post-wildfire sites to at least 110 years. Overall, these data suggest that management to sustain fern and bryophyte diversity should ensure that areas of forest beyond 110 years are represented in the landscape at appropriate spatial scales.     

基于CBS-GM的时序数据短期预测方法

介绍了时序数据常用的参数回归和非参数回归方法,分析并比较了各自的优势和局限。结合这些特点提出一种基于B样条系数(CBS)与灰色模型(GM)的组合预测方法CBS-GM。此预测方法兼有参数和非参数的优点,具有较强的适应性和稳健性。最后将提出的方法应用于实际数据(常规数据和含异常值数据)。结果表明,综合预测精度和速度,CBS-GM相比于GM(1,1)、ARMA、BP神经网络和SVM等4种常用预测方法具有一定优势,是一种实用、高效的短期预测方法。