Prebiotic properties of alternansucrase maltose-acceptor oligosaccharides

alpha-(1-6) and alpha-(1-3)-linked oligosaccharides were obtained from the reaction between sucrose and maltose, catalyzed by an alternansucrase isolated from Leuconostoc mesenteroides NRRL B-21297 and separated using a Bio-Gel P2 column in six fractions. Fractions 1, 2, and 3 were mainly composed of DP3, DP4, and DP5, respectively. However, fractions 4, 5, and 6 consisted of mixtures from DP5 to DP9, and they are identified here as DP5.7, DP6.7, and DP7.4, respectively. Potential prebiotic properties of these oligosaccharides were tested using pure and mixed cultures. Generally, in pure studies, most of the tested bacteria failed to grow or grew poorly using the DP6.7 and DP7.4 fractions and showed the greatest growth on DP3. Growth of fecal bacteria on the maltose-acceptor products was tested following an in vitro fermentation method. DP3 showed the highest prebiotic effect, followed by DP4 and DP6.7, whereas DP7.4 did not present any prebiotic activity.     

Presence of antibodies against rabies in wild boars

Serum samples of 746 shot wild boars collected throughout Slovenia during the hunting season of 2005/2006 were examined for the presence of antibodies against rabies virus: 541 samples were collected in areas subjected to yearly antirabies vaccination, and 205 samples were collected in areas where preventive antirabies vaccination was not practised. Using a modified enzyme-linked immunosorbent assay (ELISA), in 209 out of 746 sera (28%) the levels of antibodies against rabies virus were higher than 0.5 IU/ml and deemed positive. A total of 173/541 (32%) and 36/205 (18%) samples were positive in the vaccinated and nonvaccinated areas, respectively. Further analysis of 191 out of the 746 samples using the fluorescent antibody virus neutralisation (FAVN) test revealed the presence of antibodies against rabies virus in 122/191 (64%) samples. This is the first extended research reporting that antibodies against rabies virus that originate from preventive oral vaccination targeting the fox population are present in wild boar.     

MODFLOW 在井灌区地下水数值模拟

利用地下水数值模拟软件VISUAL MODFLOW，根据三河市的水文地质条件，建立三河市研究区的地下水流动模型，对三河市地下水水位进行分析和预测。模拟结果表明：计算地下水位和实测结果吻合较好，模型可以用来对该区的地下水位和水量进行模拟和预报。利用模型对该区域种植结构优化后的地下水水位进行模拟和预测。     

关于PSL602线路保护有关问题的探讨

针对国电南京自动化股份有限公司生产的PSL602线路保护,给出了3种情况下的阻抗元件躲负荷计算公式;对互感对零序补偿系数的影响进行了探讨;对PT断线时投入的过流保护以及合后继的使用给出了分析和建议.     

草籽喷播机自动导航控制器的研究——基于模糊控制

为了实现草籽喷播机自动导航控制,提高喷播机自动化、智能化的程度,以电动四轮车底盘为实验平台,开发了GPS、三维电子罗盘、超声波传感器数据采集程序和喷播机转向的模糊控制算法。在Lab VIEW环境下构建了自动导航模糊控制器,用GPS接收仪定位的两点来确定喷播机拟跟踪的直线,通过喷播机上的电子罗盘和GPS定位模块分别确定喷播机运行方向与直线的夹角α和喷播机到直线的距离λ。α和λ作为模糊控制算法中模糊控制器的输入,输出为转向驱动步进电机的转动次数n。通过实验验证得出:运用自动导航的模糊控制器,喷播机能够快速、准确地跟踪拟定的路径。     

Beta-lactoglobulin-dextran conjugates: effect of polysaccharide size on emulsion stability

A series of dextrans and beta-lactoglobulin were covalently conjugated and screened for their ability to stabilize oil-in-water emulsions. Dextrans with the molecular mass of 19.6 kDa, 87 kDa, 150 kDa, 500 kDa, and 2000 kDa were attached to beta-lactoglobulin via the Maillard reaction. The conjugates were then purified and evaluated as emulsifiers under neutral conditions. The ability to stabilize emulsions was determined by monitoring oil droplet size over time. Adsorption of the conjugates to the droplet surface was characterized by determining the protein surface load. The results show that increasing polysaccharide size increases emulsion stability up to 150 kDa before leveling off. Conversely, surface protein density remains constant until 150 kDa before decreasing with polysaccharide size. A model is presented to interpret the results.     

简析园林绿化工程的项目管理

分析园林绿化工程项目管理的现状,现场管理混乱,劳动生产率低,提出了强化项目管理的6个方面,主要包括编制合理的目标责任成本,切实做好施工前准备工作,严格按设计图纸施工,加强施工组织设计的应用,施工与养护相结合,防止成本管理流于形式.     

浅谈葫芦岛市五里河生态修复工程的创新点

简要介绍了实施葫芦岛市五里河生态修复工程的背景,重点阐述实施修复工程中排污治污、打造生态河道、建设生态园林,利用清洁可再生能源这些项目的措施.最后对五里河后期的管护提出建立强有力机构和"以河养地,以地促河"的建议.