新疆家蚕抗菌肽(Cecropin-XJ)毕赤酵母高密度发酵条件的研究

新疆家蚕抗菌肽具有明显的抑菌活性 ,利用基因工程技术生产新疆家蚕抗菌肽有助于实现工业化生产 .本研究探索通过巴斯德毕赤酵母工程菌 SMD1 1 68高密度发酵生产新疆家蚕抗菌肽 ( Cecropin-XJ)的条件 ,包括培养基中碳源、氮源、初始 p H值、磷酸盐等因素对毕赤酵母工程菌生长和抗菌肽分泌的影响 .通过多因素正交实验确定了生产新疆家蚕抗菌肽高密度发酵培养的最适培养条件 ,条件优化后毕赤酵母工程菌发酵后密度OD6 0 0 可达 48.92± 0 .5 9,较优化前提高了 3倍 ,为基因工程生产新疆家蚕抗菌肽奠定了基础     

丝素蛋白亚基研究

丝素蛋白亚基研究于同隐蔡再生黄伟达施华芳李宏杰（复旦大学高分子系）（复旦大学生物化学系上海２００４３３）关键词丝素蛋白，氨基酸，亚基组成，柱层析，聚丙烯酰胺凝胶电泳作为天然纤维的蚕丝在国防、工农业生产、医药卫生及人们日常生活中应用日益广泛，有关...     

Platinum determination by NAA in two road dust matrices

In this work, a method for platinum determination was studied. The method is based on neutron activation analysis coupled with a preirradiation concentration/separation procedure employing a Dowex ion exchange chromatographic column to overcome serious interferences from other elements.Two environmental matrices, Road Dust CW7 and Road Dust CW8, collected and prepared by the Bureau Communautaire de Reference as candidate reference materials, were analysed. Finally, only CW8 was certified as BCR 723. The results were compared with data obtained by other laboratories with various techniques.     

丝素膜上药物渗透量对溶液PH值的响应

蚕丝丝素蛋白膜是一种具有弱碱性和弱酸性的两性荷电膜。因此在丝素膜－水溶液体系中，水溶液ｐＨ值变化会影响丝素膜上溶质的渗透速度和渗透量。丝素膜的等电点ｐＨ≈４．５。丝素膜上药物渗透实验的结果表明：在ｐＨ＝３．０～９．０的范围内，当溶液的ｐＨ＜４．５时，丝素膜带正电，正离子苄三甲氯化铵的渗透系数下降；当溶液的ｐＨ＞４．５时，丝素膜带负电，负离子酚磺酸钠的渗透系数明显下降。中性分子间苯二酚在丝素膜上的透过不受外部溶液ｐＨ值变化的影响。当溶液的ｐＨ＞８或ｐＨ＞４．５时，离子化的药物５－氟尿嘧啶或维生素Ｃ的渗透系数明显变小，这是因为两者分别在ｐＨ＝８（ｐＫａ＝８．０）和ｐＨ＝４．５（ｐＫａ＝４．２５）以上变成带电离子。这表明离子化药物在蚕丝丝素膜上的渗透速度和渗透量对溶液ｐＨ值变化有较好的响应特性。     

丝素蛋白纤维的接枝聚合Ⅰ.用四价铈盐引发丝素蛋白纤维接枝烯类紫外稳定剂

本文研究了四价铈盐引发桑蚕丝素蛋白纤维接枝聚合烯类紫外稳定剂,2-羟基-4-丙烯酰氧二苯酮(HAOBP)的反应。有机溶剂作为反应介质对接枝聚合有重要影响,丝素蛋白纤维在不同溶剂中接枝聚合HAOBP,其接枝率具有下列顺序: DMSO>DMF>DMAc>Acetone>MeOH>EtOH 扫描电镜照片表明,接枝丝素蛋白纤维表面趋于粗糙,这种现象由接枝于表面的聚合物所引起。本文还用红外光谱和紫外光谱表征了接枝丝素蛋白纤维。热重分析结果表明,接枝丝素蛋白纤维的热稳定性和紫外稳定性都得到了显著的改善。力学性能测试结果说明,接技丝素蛋白纤维的断裂强度和断裂延伸率大幅度下降。     

Effect of degumming time on silkworm silk fibre for biodegradable polymer composites

Recently, many studies have been conducted on exploitation of natural materials for modern product development and bioengineering applications. Apart from plant-based materials (such as sisal, hemp, jute, bamboo and palm fibre), animal-based fibre is a kind of sustainable natural materials for making novel composites. Silkworm silk fibre extracted from cocoon has been well recognized as a promising material for bio-medical engineering applications because of its superior mechanical and bioresorbable properties. However, when producing silk fibre reinforced biodegradable/bioresorbable polymer composites, hydrophilic sericin has been found to cause poor interfacial bonding with most polymers and thus, it results in affecting the resultant properties of the composites. Besides, sericin layers on fibroin surface may also cause an adverse effect towards biocompatibility and hypersensitivity to silk for implant applications. Therefore, a proper pre-treatment should be done for sericin removal. Degumming is a surface modification process which allows a wide control of the silk fibre's properties, making the silk fibre possible to be used for the development and production of novel bio-composites with unique/specific mechanical and biodegradable properties. In this paper, a cleaner and environmentally friendly surface modification technique for tussah silk in polymer based composites is proposed. The effectiveness of different degumming parameters including degumming time and temperature on tussah silk is discussed through the analyses of their mechanical and morphological properties. Based on results obtained, it was found that the mechanical properties of tussah silk are affected by the degumming time due to the change of the fibre structure and fibroin alignment.     

Evaluation and analysis of the environmental noise of Messina, Italy

In this paper, the results of a study on the environmental noise pollution of the city of Messina (Italy) are presented. The investigation has included a preliminary classification of the territory in six acoustically homogeneous areas according to Italian noise regulations. On the basis of the resultant acoustic zoning 35 sites were selected for an experimental survey. This last has been carried out by extensive measurements of the main indexes for noise pollution (L_eq, L₁, L₁₀, L₅₀, L₉₀, L₉₉) and of the traffic flow and composition. Results indicate that: (a) main roads of Messina are overloaded by traffic flow during day-time period and that in all the examined sites daily average sound levels due to road traffic exceed environmental standards by about 10 dBA; (b) environmental noise exhibits a certain degree of spatial variance resulting primarily from the peculiar geo-morphological structure of the town and from the transport infrastructure and (c) more than 25% of residents should be highly disturbed by road traffic noise.     

Multiclass multicriteria mixed equilibrium on networks and uniform link tolls for system optimum

In this paper, we consider a unified framework of multiclass multicriteria mixed equilibrium, and the existence of uniform link tolls supporting such a mixed equilibrium as a system optimum. The network users are divided into different classes, and each class of traveler perceives his/her disutility associated with a route as a combination of two criteria given, respectively, by the travel time disutility and the time-irrelevant travel disutility. And users in a common class follow either user equilibrium (UE) principle or Cournot–Nash (CN) principle. A variational inequality model characterizing the multiclass multicriteria UE–CN mixed equilibrium behavior is developed. By utilizing the dual theory, we establish the existence of uniform link tolls supporting such mixed equilibrium as a system optimum.     

Assessment of environmental contamination risk by Pt, Rh and Pd from automobile catalyst

The main active components of present-day car catalysts are the noble metals Pt, Pd and Rh, belonging to the platinum group elements (PGEs). It is recognized that these elements are being spread into the environment to an as-yet incompletely known extent, mainly due to surface abrasion of the catalyst during car operation. These new pollutants have motivated extensive research on PGE determination. Our work is planned to ascertain the health and ecosystem risks of these PGEs emitted through a series of interrelated objectives that address the pathway of these elements from the catalyst to the different environmental compartments. Combined studies of catalyst surface abrasion and exhaust fumes analysis, the monitoring of Pt, Pd and Rh in airborne particles and road dust sediments and bioaccumulation studies in aquatic organisms, plants and urine enable a realistic assessment of the risk that this release represents for man and environment. In this work some previous results are presented.     

Advanced driver assistance system: Road sign identification using VIAPIX system and a correlation technique

We present a three-step approach based on the commercial VIAPIX® module for road traffic sign recognition and identification. Firstly, detection in a scene of all objects having characteristics of traffic signs is performed. This is followed by a first-level recognition based on correlation which consists in making a comparison between each detected object with a set of reference images of a database. Finally, a second level of identification allows us to confirm or correct the previous identification. In this study, we perform a correlation-based analysis by combining and adapting the Vander Lugt correlator with the nonlinear joint transformation correlator (JTC). Of particular significance, this approach permits to make a reliable decision on road traffic sign identification. We further discuss a robust scheme allowing us to track a detected road traffic sign in a video sequence for the purpose of increasing the decision performance of our system. This approach can have broad practical applications in the maintenance and rehabilitation of transportation infrastructure, or for drive assistance.