Influence of marine oligosaccharides on the response of various biological systems to UV irradiation

Low molecular weight alginate-derived oligosaccharide (ADO) (373–571 Da) and chito-oligosaccharide (COS) (855–1671 Da) were purified from alginate and chitosan, and known as marine oligosaccharides with polyanionic and polycationic properties, respectively. We compared the effects of ADO and COS on cell regulation using several biological models (Candida albicans, Escherichia coli and Bacillus subtilis spore), cellular uptake determination, erythrocytes haemolysis inhibition and antioxidant capacity assay to investigate stress response under UV radiation. Our results further confirmed the anti-UVR potential of ADO and COS and their potential for commercial UVR protector application in the area of functional foods as food ingredients.     

Effects of fermentation conditions and soybean peptide supplementation on hyaluronic acid production by Streptococcus thermophilus strain YIT 2084 in milk

To increase the hyaluronic acid (HA) yield from Streptococcus thermophilus YIT 2084, fermentation conditions (pH, temperature, agitation, aeration) were optimized in milk-based medium, and the effects of supplemental soybean peptides, which have different molecular weight distributions, were determined. HA production was enhanced to approximately 100 mg/l at pH 6.8 and 33–40 °C. Agitation speed and aeration rate slightly affected HA production. Soybean peptides including those of high molecular weight (approximately 27 to 130 kDa) further increased HA production to 208 mg/l under the optimal condition (pH 6.8, 35 °C, 100 rpm), which was 20-fold greater than non-optimal condition. HA production was no longer related to the specific growth rate. The HA produced under the optimal condition included a large amount of high-molecular-weight fraction of 100 to 2000 kDa, compared with under the basal condition without optimization.     

非确定性视角下的产业类历史地段更新探索——郑州市国棉三厂厂区更新设计

产业类历史地段的更新,是现阶段城市更新中的重要课题。从非确定性视角出发,对郑州市国棉三厂厂区的更新设计进行了一定的探索。结合现有城市规划中存在的问题,提出保护和保留原有的厂房和构件,采用拼贴式、微循环的模式进行更新,在设计中体现了变化的、动态的、整体的、弹性的思想观和"混合共生、灵活应变"的设计理念。     

Bursty Behaviour of Turbulent Particle and Energy Fluxes in Edge Plasma of HT-7 Tokamak

High time resolution measurements of the electrostatic fluctuations and the turbulent particle and energy fluxes have been performed with a Langmuir probe array in the edge plasma in HT-7 tokamak. Bursty behaviour was observed in the time resolved turbulent fluxes with positive skewness and large kurtosis. The contribution of the large sporadic bursts to the transport losses were estimated. The analysis shows that the turbulent fluxes have different behaviour in different frequency domains and the probability distribution functions （PDFs） of the particle and energy fluxes present two distinct scaling ranges. All these are essentially consistent with the predictions of the self-organized criticality （SOC） model, though further studies are needed.     

基于VB的山东省高速公路工程地质信息查询系统的建立

截至2003年底，山东省高速公路总里程已经位居全国第一位。建设覆盖全省高速公路工程地 质状况信息查询系统，不仅有利于该地区高速公路建设管理的信息化 |而且对未来该地区高 速公路维护、建设、规划开发具有良好的指导作用。在系统建设中，采用地理信息系统软件 ArcInfo7.1.1作为数据采集、处理的主要工具 |以地理信息系统软件ArcView3.2二次开发语 言Avenue、COM组件MapObjects2.1、通用软件开发平台Visual Basic6.0为平台 |结合DDE技 术，实现软件平台之间的通讯，从而实现了对高速公路工程地质样点分析信息的图像查询。 通过创建使用Excel的Active对象，实现对路段工程地质信息、地质灾害、路段基本信息空 间叠置查询。该查询系统设计思路新颖，适用于高速公路工程地质信息的管理、查询、分析 与计算，是一个较有实用价值的公路查询信息系统。     

用光声信号飞越时间法对纯铜脉冲激光烧蚀的研究

利用脉冲激光束轰击金属样品表面时在周围空气中激发的光声信号研究了纯铜的激光烧蚀。实验中,用He-Ne探测光束偏转方法检测光声信号,并根据光声信号飞越时间随激光能量密度的变化测定了纯铜的脉冲激光烧蚀阈值。文中还给出了一种理论估计脉冲激光烧蚀阈值的较为实用的方法。纯铜的脉冲激光烧蚀阈值的实测值约为3.0 J/cm2,理论估计值为3.2 J/cm2。两者符合较好。结果表明,光声信号方法是测定纯铜的脉冲激光烧蚀阈值的一种简单可行的方法。     

Preparation and Characterization in vitro of Sustained-release Captopril/Chitosan-gelatin Net-polymer Microspheres （Cap/CGNPMs）

The captopril/ Chitosan-gelatin net-polymer microspheres （ Gap/ CGNPMs ） were prepared using Chitosan （ CS ） and gelatin （ Gel ） by the methods of emulsification. A cross linked reagent alone or in combination with microcrystalline cellulose （ MCC ） was added in the process of preparation of microspheres to eliminate dose dumping and burst phenomenon of microspheres for the improvemeat of the therapeutic efficiency and the decrease of the side effects of captopril （ Cap ）. The results indicate that Cap/ CGNPMs have a spherical shape , smooth surface roorphology and integral inside structure and no adhesive phenomena and good roobility , and the size distribution is mairdy from 220 to 280 μm. Researches on the Cap release test in vitro demonstrate that Cap/ CGNPMs are of the role of retarding release of Cap compared with Cap ordinary tablets （COT）, embedding ratio （ER） , drug loading （ DL ）, and swelling ratio （ SR ）, and release behaviors of CGNPMS are influenced by process conditions of preparation such as experimental material ratio （EMR） , composition of cross linking reagents. Among these factors , the EMR（1/4）, CLR （ FOR ＋ TPP） and 0.75% microcrystulline cellulose （MCC） added to the microspheres are the optimal scheme to the preparation of Cap/CGNPMs. The Cap/CGNPMs have a good characteristic of sustained release of drug, and the process of emulsifieation and crossinking process is simple and stable. The CGNPMs is probable to be one of an ideal sustained release system for water-soluble drugs.     

壳寡糖对胰岛β细胞的保护及其体内抗氧化作用的研究

研究了体外研究酶解法制备的壳寡糖(COS)对胰岛β细胞的保护作用,并进一步探讨COS对链脲佐菌素(STZ)诱导的糖尿病(DM)大鼠胰腺的保护及其抗氧化保护机制.通过壳聚糖酶降解壳聚糖制备得到水溶性、低分子量的COS,在细胞水平上,通过形态学观察、四氮唑蓝(MTT)比色法、DNA凝胶电泳、彗星电泳等方法研究不同浓度的COS对链脲佐菌素损伤胰岛β细胞的保护和抑制细胞凋亡的作用;进行了体内实验,通过一般状态观察和病理组织学检查研究了COS对链脲佐菌素诱导的DM大鼠的胰腺保护作用,并对血清中谷胱甘肽过氧化物酶(GSH-PX)、超氧化物歧化酶(SOD)、丙二醛(MDA)浓度、总抗氧化能力(T-AOC)进行了测定.结果表明,COS可以抑制链脲佐菌素诱导的胰岛β细胞凋亡,对受损的胰岛β细胞有显著的保护作用;COS各剂量组对DM大鼠总抗氧化能力和SOD活力均有显著改善,MDA浓度与STZ损伤组比较均有极显著差异;胰腺组织学检查表明COS能减轻胰岛萎缩、数量减少、胰岛细胞丢失、核固缩等胰岛细胞退行性改变症状.     

Mixed nitrogen source effect in the hydrothermal synthesis of cubic BN

Mixed nitrogen source effect was applied in the synthesis of boron nitride (BN) by hydrothermal method. The experimental results revealed that, compared to those obtained by using only two kinds of nitrogen sources, when three kinds of nitrogen sources were used during the synthesis of BN, it was more easier to obtain BN samples with cBN as the dominant phase. Furthermore, if this effect was applied together with the two-step reaction method, nearly pure cBN can be obtained. The results of X-ray diffraction (XRD), Fourier transformation infrared spectroscopy (FTIR), transmission electron microscopy (TEM), selective area electron diffraction (SAED), high-resolution transmission electron microscope (HRTEM) and X-ray photoelectron spectroscopy (XPS) measurements proved that the major phases in the samples are cBN.