用于输送siRNA的聚乙烯亚胺-聚乙二醇二丙烯酸酯纳米凝胶

阐述了一种新的用于输送小干扰核糖核酸(siRNA)的聚乙烯亚胺-聚乙二醇二丙烯酸酯纳米凝胶的合成及其表征.在反相微乳液体系中,聚乙烯亚胺(PEI)和聚乙二醇二丙烯酸酯(PEG-DA)通过麦克尔加成交联得到纳米凝胶.1H-NMR和FTIR的结果充分证明纳米凝胶的化学结构,而动态光散射则表明纳米凝胶的颗粒粒径均匀,约为180 nm,zeta电位为37.9 mV.同时,MTT结果表明纳米凝胶在高达1 mg/mL的浓度下对MCF-7细胞也基本没有毒性.凝胶阻滞实验证明纳米凝胶在体外可以通过静电相互作用稳定结合siRNA.转染实验结果表明纳米凝胶与GFP siRNA的复合物能降低MCF-7 KMRV细胞(一种能稳定表达GFP蛋白的MCF-7细胞系)GFP蛋白的表达.以上结果证明这种生物相容性的纳米凝胶可以结合并输送siRNA进入细胞,沉默相关基因的表达.     

微量沉淀保护剂对国画颜料耐久性影响的研究

基于古字画保护的完整性要求,本实验选取了6种国画颜料,研究了绢本字画保护剂对这6种国画颜料耐久性的影响。样品经干热、湿热和紫外光照老化实验后,通过测定各种颜料的色差值来评价保护剂对颜料的保护性能。结果表明:该微量沉淀保护剂处理的国画颜料经各种人工加速老化之后测得的色差值均比没有处理的小,可见该保护剂对国画颜料也起到保护作用。     

rPA(K)的原核表达及其产物的初步纯化

rPA(K)是经过缺失/定点突变技术所获得的t-PA突变体.本实验以IPTG诱导,实现了rPA(K)在原核系统中的表达.实验证明目的 产物的表达形式为包涵体,且当以IPTG诱导3h时,表达量最高,为41%.此后对该表达产物进行了初步纯化,即通过对不同超声破碎次数,包涵体洗涤液(脲,Trition Ⅹ-100,乙醇)的不同浓度对纯化的影响因素进行了摸索.结果表明,超声2次,2M脲,0.5%Triton Ⅹ-100,20%乙醇对目的蛋白纯化的效果最好,从而为进一步的纯化和复性奠定基础.     

纳米材料对纸质档案保护影响初探

一、纳米材料及其在造纸工业中的应用 纳米是一个长度单位,1nm=10^-9m,约相当于10个原子并列在一起的长度。目前国际上将处于1～100nm尺度内的超微颗粒及其致密的聚集体,以及由纳米微晶所构成的材料通称为纳米材料,其包括金属、非金属、有机、无机和生物等多种粉末材料。纳米材料具有许多优良的物理化学性能。如普通金属为导体,但纳米金属微粒在低温时由于量子尺寸效应会出现电绝缘性;铁磁性物质进入纳米级,由于由多畴变成单畴,于是显示极强的顺磁效应等等。有些纳米材料还有特别的化学催化性质、光催化性质、光电化性质、化学反应动力学性质等。     

健康新知

好消息：纳米抗菌纸用于健康生活 一种具有杀灭致病细菌能力的新型纸张可被应用到从抗菌绷带、食物保鲜到鞋子防臭的各个方面。介绍这一新型材料的文章发表在美国化学学会出版的《纳米》月刊上。据作者范春海等介绍,这种名为graphene的材料由英国人于2004年首次发现,其后各国科学家就其在太阳能电池、计算机芯片等领域的应用展开竞争。     

CaCO3填充母料产品开发及性能研究

填充母料是将片各种填充剂直接加入树脂中,然后混合、塑炼、挤出造粒。采用填充母料,可得到各组分均匀的制品,成型工艺稳定,生产效率高本文在PP或ABS中加入无机填料碳酸钙,以及钛酸酯偶联剂、液体石蜡、硬脂酸等其他助剂经过挤出合成了CaCO3填充母料,产品以熔体流动速率（MFR）和断裂伸长率以及拉仲强度等指标进行表征,得到了性能较好的产品配方。     

基于资源视角的IT能力对企业绩效的影响研究

为构建IT能力和企业绩效的关系,以2005-2008年“中国企业信息化500强”信息为基础,采用样本配对比较的方法,对沪深两市84家制造企业的财务表现数据进行统计分析。检验结果发现,具有较高IT能力的研究样本的总资产回报率、销售利润率和主营业务成本,都显著优于控制样本,而运营费用恰好相反。最后对结论进行详细解释和分析。     

基于KNN与自动检索的迭代近邻法在自动分类中的应用

本文研究了一种基于KNN与自动检索的自动分类算法———迭代近邻法 (IterativeKNN ,I KNN) ,用以解决KNN算法在小样本库的环境下分类效果不佳的问题。在无法得到足够的定类样本时 ,通过检索的方法将待分样本的局部主题特征放大 ,进而得到足够定类的相似样本。实验证明 ,迭代近邻法既增加了获取相似样本的几率 ,同时也有效地控制了样本相似度条件限制放宽后可能引入的分类噪声 ,在实际应用中能较好地提升自动分类系统的查全率和查准率。     

壳聚糖多孔支架电化学辅助沉积羟基磷灰石涂层研究

采用电化学辅助技术控制阴、阳两极溶液中的钙、磷离子定向迁移,进入壳聚糖多孔支架内部发生反应并在孔隙表面沉积,制备了有机-无机复合多孔支架.应用XRD、SEM、煅烧法、孔隙率测定和压缩实验对支架的组成、形貌、无机物沉积量、孔隙率以及压缩强度进行了表征.研究表明,处理后支架孔隙表面沉积了低结晶度的羟基磷灰石,低倍下沉积层均匀致密,在高的放大倍数下发现,沉积层中存在大量的微孔,沉积层表面存在着球状物,该球状物是由许多小片组成的.沉积6 h时沉积量为支架质量的2.81%,支架孔隙率由96.0%减少到89.8%.与纯壳聚糖支架相比,复合支架的压缩强度由0.0550 MPa提高到0.0998 MPa.     

多Agent学生模型及在考试系统中的应用研究

提出了一种基于多Agent考试系统的学生模型,采用模糊逻辑的方法,利用Agent的智能推理能力,准确地推理出学生的认知水平,实验证明该系统具有一定的自适应性、可行性。     

British Writings on Romania: From Travel Accounts to Studies

This article surveys a sample of sources of the information about Romania available to British readers in nineteenth century British newspapers and periodicals. It traces first contacts between the Romanian lands and Britain after the union of the principalities of Wallachia and Moldavia in 1859, then after their independence from the Ottoman Empire. The article highlights an increased Romanian interest in British periodicals, which reported and reviewed Romanian literature and scholarship. The article concludes that nineteenth century British newspapers and periodicals offer a great variety and wealth of new material previously unavailable or unknown to researchers. It also states that only a portion of a large quantity of this material has been indexed and is therefore available via the bibliographic sources mentioned in the article. The author argues for the need of a new and updated British-Romanian bibliography, which can draw on new online resources offering access to thousands of new newspapers and periodical records.     

Politicking for the Public Library

ABSTRACT

In today's current political environment raising support for millage renewals, bond campaigns or even millage continuations for public libraries is affected by national politics, and a tendency towards tax aversion on principle across the country. The lessons we can learn from the governing boards of small and rural public libraries are worth raising up to a greater national consciousness. Board governance, community consciousness, and facilities management are clear and logical tools that elected boards of public libraries can use to politick for support of libraries.     

Slavic Approval Plans: What Works and What Doesn't

ABSTRACT

The paper looks at library approval plans for material published in Slavic, East European, and Eurasian countries from the selector's point of view. Reasons why a selector would or would not want one are examined. Success with approval plans requires monitoring receipts, as well as good and ongoing communication among the selector, the acquistions department, and the vendor. A preliminary list of vendors offering approval plans for the countries of the region appears in the appendix.     

Architectures of Knowledge and Literary Tradition: A History of the Almanac in Croatia

ABSTRACT

The history of the almanac in Croatia is reconstructed through primary research in bibliographic and archival sources. The almanac is a vehicle for knowledge communication in informal contexts, engaging both oral tradition and literary forms traceable to medieval literacy and ways of structuring knowledge. The history of the almanac in Croatia reflects the changing context of the book trade, literacy, and the evolution of language. Four main stages are identified: (1) the beginning of the annual almanac in the seventeenth century; astrological almanacs reflecting the sensibility of the Baroque period; (2) the Enlightenment's stimulation of almanac publishing in the spirit of contemporary secular reforms in agriculture and education; (3) nineteenth-and twentieth-century almanac trade, showing complex and overlapping networks for the production, distribution and appropriation of printed almanacs;(4) roughly the end of World War II, when the almanac slowly moved out of the role of a popular mass medium and into specialized niches represented by regional, diaspora, and religious almanacs.     

How Digital Content Resellers are Impacting Trade Book Publishing

Some key questions for publishers in today’s market are: Could Amazon’s recent merger and acquisitions strategy create a disruptive or paradigm shifting business model in the publishing industry? Do their recent actions post mergers and acquisitions illustrate a predicable pattern of behaviour that publishers can strategize around? This paper will explore these questions and look at some of the possible reasons behind Amazon’s business practices and the possible consequences to publishers.     

由“资源集聚”向“需求导向”转变——对武汉科技信息服务平台建设的思考

为进一步提升武汉科技信息共享服务平台使用效率,本文从平台资源建设、资源应用、供需对接方式和供需特点等方面分析了武汉科技信息资源服务现状;基于需求和利用的角度,结合平台管理实践和走访用户、问卷调查等研究方法,从信息资源需求主体和平台自身建设管理两个维度,找出制约科技资源供需对接的主要因素;以市场化和制度化为创新理念,从政策创新、机制创新、市场化服务、环境营造、人才培养等方面提出平台建设由“资源集聚”向“需求导向”转变的对策建议.     

Germany's New Culture of Welcome—Our Libraries are an Essential Part of it

ABSTRACT

German authorities are expecting more than 1 million refugees by the end of 2015. These people come to Germany to seek protection and assistance and to build a new life, therefore it is important to welcome them and to assist them in their integration as soon as possible. This situation creates a versatile and perfectly fitting opportunity for cultural and educational programs, including libraries, which can play a vital role in this integration process. The key to integration is the knowledge of the German language, and the most important challenge now is to teach the necessary language skills to as many asylum-seekers as possible.     

Syndicating Rich Bibliographic Metadata Using MODS and RSS

Abstract

Many libraries use RSS to syndicate information about their collections to users. A survey of 65 academic libraries revealed their most common use for RSS is to disseminate information about library holdings, such as lists of new acquisitions. Even though typical RSS feeds are ill suited to the task of carrying rich bibliographic metadata, great potential exists for developing applications that can exploit metadata exposed to Web services via RSS. Using the MODS metadata format, entire catalog records can be seamlessly embedded in RSS 2.0 feeds. Existing tools, such as Library of Congress Java toolkits and XSLT stylesheets, can facilitate this process, while a new XSLT stylesheet may be used to create the RSS feeds complete with MODS records. As an example of the added functionality these MODS/RSS feeds can offer, records from a MODS-enriched RSS feed can be ingested into a non-RSS application such as Zotero. As more emerging library technologies use Web services architectures to handle data objects, the ability to syndicate catalog records will become more critical to providing innovative library Web services.     

Selling Women on PDAs from “Simply Palm” to “Audrey”: How Moore's Law Met Parkinson's Law in the Kitchen

This essay investigates key moments in the history of personal digital assistant (PDA) marketing to women. Analyzing promotional texts for three PDAs that received considerable press coverage from 1999 to 2001, this essay explores the cultural significance of the convergence of anxieties about women's place in the gendered division of labor with the computer industry's changing marketing imperatives. Drawing on an array of promotional texts, including news articles, press releases, promotional Web sites, and ads appearing in newspapers and magazines, this paper tells the story of how the computer industry aimed to sell smaller, faster computing devices to women while promising to mediate and thus reproduce women's overwork as paid and familial laborers. After experimenting with the PDA as a sexy fashionable gadget for working women, marketers approached women as mothers with “Audrey,” an Internet appliance designed for the kitchen.     

Communicating With Bank Stakeholders During Recession: Why It's Important,Who Is Doing It,and How to Stay in the Loop

This study explores the attitudes and actions of bank managers toward communication spending during recession. Results of this study indicate that organizational leaders cut communication spending early during recession and also erroneously rely on the bank's financials to mitigate irrational customer withdrawals. This research is used to illustrate the need for public librarians to meet the needs of bank stakeholders when their institution ceases to communicate during crises, for academic librarians to educate students in undergraduate and graduate programs regarding heightened information needs during recession, and for corporate librarians to understand a potential avenue for competitive advantage during recession.