In vitro antioxidant activity and potential inhibitory action against α-glucosidase of polysaccharides from fruit peel oftea (Camellia sinensis L.)简

The conditions for extracting polysaccharides from tea (Camellia sinensis L.) fruit peel (TFPPs) were studied. Three parameters (temperature, time, and liquid/solid ratio) affecting the extraction of TFPP were optimized using response surface methodology (RSM). Under the optimized conditions, the yield of TFPP was predicted to be 4.98%. The physicochemical properties, in vitro antioxidant activities, and inhibitory effects on α-glucosidase of fractionated TFPPs (TFPP-0, TFPP-20, TFPP-40, and TFPP-60) were investigated. We found that the TFPPs were all acid protein-bound heteropolysaccharides, although with different chemical compositions. They had not only remarkable scavenging activity on 2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) and reducing activity, but also excellent inhibitory potential against α-glucosidase in vitro. Our results suggest that tea fruit peel could be treated as a potential bioresource for the development of polysaccharide antioxidants.     

“80后”网络话语对其形象的再现与建构

“80后”指中国1980-1989十年中出生的人,因其特殊的成长环境而备受公众和媒介的关注,是一个时代的文化潮流,具有鲜明的时代烙印.本文主要采用内容分析法,以“80后”网络话语文本为研究对象,从话语分析角度出发研究网络媒介构建的“80后”身份和形象特点及其构建方式,同时结合“80后”所处的时代背景和社会环境,分析“80后”网络媒介形象的成因.     

在CROMEMCO微型计算机上开发Z-80单板机

Z-80单板计算机在国内具有大量的用户,但怎样方便地开发Z-80单板计算机,使其强大的功能得以充分发挥是一个很重要的问题。本文叙述了利用微型计算机开发单板机的一般方法,并介绍了一个在CROMFMCO微机上开发TP801单板机的实例。     

“80后”员工组织激励维度测量及其对人才策略的启示

本文通过实证研究的方法,以"80后"基层员工为调查样本,运用探索性因子分析和验证性因子分析,提取并验证了组织激励具有领导特征、制度环境、职业发展、薪酬福利、同事关系等5个因子。在明确组织激励结构维度的基础上,对比样本对各测量指标及因子的重视程度,结果表明,"80后"对5个因子的重视程度依次是职业发展、薪酬福利、领导特征、同事关系和制度环境。文章以此为依据分析了在"80后"基层员工激励策略中应加以重视和强化的方面,以期对企业的人力资源管理工作提供参考和借鉴。     

Effect of high glucose levels on the calcification of vascular smooth muscle cells by inducing osteoblastic differentiation and intracellular calcium deposition via BMP-2/Cbfα-1 pathway

In this paper,we investigate the effect and the possible mechanism of high glucose levels on the calcification of human aortic smooth muscle cells (HASMCs).HASMCs were divided into four groups: normal glucose group (NG),osmolality control group (OC),high glucose group (HG,HASMCs culture medium containing 30 mmol/L glucose),and high glucose plus recombinant human Noggin protein (bone morphogenetic protein-2 (BMP-2) antagonist) group (HN).The mRNA levels and the protein expressions of BMP-2 and core binding factor alpha-1 (Cbfα-1) were measured by real-time quantitative polymerase chain reaction (PCR) and Western blot.After induced by 10 mmol/L β-glycerol phosphoric acid,cells were harvested for assessments of alkaline phosphatase (ALP) activities at Days 1,2,and 3,and intracellular calcium contents at Days 7 and 14,respectively.High glucose levels increased the mRNA levels and the protein expressions of BMP-2 and Cbfα-1 (P0.05).The expression of Cbfα-1 was partially blocked by Noggin protein (P0.05),while BMP-2 was not (P0.05).After being induced by β-glycerol phosphoric acid,high glucose levels increased the ALP activity [(48.63±1.03) vs.(41.42±2.28) U/mg protein,Day 3;P0.05] and the intracellular calcium content [(2.76±0.09) vs.(1.75±0.07) μmol/mg protein,Day 14;P0.05] in a time-dependent manner when compared with the NG group,while the ALP activity could not be blocked by Noggin protein [(48.63±1.03) vs.(47.37±0.97) U/mg protein,Day 3;P0.05].These results show that high glucose levels can evoke the calcification of HASMCs by inducing osteoblastic trans-differentiation and intracellular calcium deposition via the BMP-2/Cbfα-1 pathway,which can be partially blocked by Noggin protein.     

80后英语教师职业倦怠现状及其成因研究

目前教师职业倦怠研究的对象还十分宽泛,并没有针对某一特定阶段或时代的教师。中国80后是在特定的时代背景下成长起来的富有现代性文化内涵的一代,他们已在抗震救灾和奥运中崭露头角,而英语学科教师本身又具有某些特殊的个性,因此对80后英语教师职业倦怠问题的研究具有现实意义。     

长尾理论给网络出版带来的启示

作为对我们所熟知的“80／20法则”的悖反或补充,“长尾理论”被《商业周刊》评为2005年度最有商业价值的概念之一。该理论认为,运用信息技术可消除传统商业世界的很多约束,以至于需求不旺或销售不佳的产品共同占据的市场份额,可以和那些数量不多的热卖品占据的市场份额相匹敌甚至更大。长尾理论作为网络商业的一个新的理论基础,为网络出版的发展带来启示。     

Performance Improvement of DCF Supporting Multi-Rate in IEEE 802.11b Wireless LAN

Inrecent years ,IEEE802.11 wirelesslocal area net-work (WLAN) has emerged as a prevailing technology forthe (indoor) broadband wireless access to internet for themobile/portable devices . In IEEE 802.11 standards ,802.11b has become the most widely used v…     

Beauty and Character: Values Beyond Beauty in Architecture

Formalist conceptions of aesthetic goals began to give way from the 17^th century on to rationalist accounts of experience. Beauty as described as essential by Renaissance thinkers was reconceived as just one possibility, with the sublime in Burke's account as another. In the early 20^th century Clive Bell again asserted a formalist position with his argument for significant form. The weakness of the formality position, and the need for a richer, more contextual account of aesthetic goals and experience is argued with reference to the idea of thick and thin concepts as applied by Bernard Williams to ethics, Wittgenstein's attention to the way in which language is used in a specific context, and Scruton's emphasis on an informed conception of the object of aesthetic attention. Beauty, in Alberti's procedural account if not in his version of the Platonic ideal, can be seen to continue to have critical value. The idea of character, however, offers a broader range of possibilities for experience and of goals for design.