Polyethylenimine-cyclodextrin-tegafur conjugate shows anti-cancer activity and a potential for gene delivery

Polyethylenimine-cyclodextrin-tegafur (PEI-CyD-tegafur) conjugate was synthesized as a novel multifunctional prodrug of tegafur for co-delivery of chemotherapeutic agent tegafur and enhanced green fluorescent protein (EGFP) reporter plasmid DNA. Conjugation of tegafur to PEI-CyD via chemical linkage was characterized by ¹H NMR spectrometry and ultraviolet (UV) spectrometry. PEI-CyD-tegafur was able to condense plasmid DNA into complexes of around 150 nm with positive charge at the N/P ratio of 25, in accordance with electron microscopy observation of compact and monodisperse nanoparticles. The results of in vitro experiments showed enhanced cytotoxicity and considerable transfection efficiency in B16F10 cell line. Therefore, PEI-CyD-tegafur may have great potential as a co-delivery system with anti-cancer activity and potential for gene delivery.     

基于专利合作网络的北京国际科技合作分析

以美国专利商标局申请库收录的2001-2013年北京国际科技合作专利为数据源,运用文献计量和社会网络的方法对北京国际科技合作专利的逐年发展情况,主要合作国家、重点科研机构、活跃人才以及热点领域的合作情况作出全面的分析和系统的解读,揭示了北京国际科技合作专利快速增长等现状特征,探讨了当前北京国际科技合作在知识产权共享、企业创新能力等方面的问题,从政府的支持力度和要素流动等角度提出了建议对策。     

论文献的科学评价功能

论文献的科学评价功能娄策群ＡＢＳＴＲＡＣＴＳｉｎｃｅｐｕｂｌｉｃａｔｉｏｎｓａｒｅｒｅｓｕｌｔｓｏｆｒｅｓｅａｒｃｈａｎｄｔｈｅｉｒｍｅ－ｄｉａ，ｔｈｅｙｒｅｆｌｅｃｔｖａｒｉｏｕｓａｓｐｅｃｔｓｏｆｓｃｉｅｎｃｅａｎｄｔｈｕｓｈａｖｅｔｈｅｆｕｎｃ...     

陈鹤琴办园理念的新实践

鼓楼幼儿园是陈鹤琴先生1923年创办的。80多年来幼儿园遵循陈老的办固理念，在幼儿教育中国化、科学化、时代化上进行了不懈的探索，并在努力探索新时期幼儿教育工作的规律和特点等方面有所成效。     

新型含硫萃淋树脂吸附贵金属的研究：石油亚砜萃淋树脂吸附富集金

测定了石油亚砜萃淋树脂的吸附性能，其饱和吸附容量Ｑ＝９０ｍｇＡｕ／ｇ树脂，金的吸附反应速率常数Ｋ＝１．０２×１０￣（－３）ｓ￣（－１），热焓△Ｈ＝－６．７０ｋＪ／ｍｏｌ，自由能变化△Ｇ￣（２９８）＝－２０．５９ｋＪ／ｍｏｌ，熵变△Ｓ＝４６．６Ｊ／ｍｏｌ·Ｋ．树脂吸附金的反应符合Ｆｒｅｕｎｄｌｉｃｈ等温吸附式．探讨了树胎吸附金的反应机理．用酸性硫脲或亚硫酸钠溶液均能定量洗脱吸附在树脂上的Ａｕ（Ⅲ），树脂可再生使用．     

合成生命之探索——人造噬藻体

人造生命是多种学科交叉、高新技术集成的系统工程,随着科学技术的发展,特别是基因组全人工合成技术的形成,这个梦想的实现开始变得可能。噬藻体是原核藻类（蓝细菌）的病原,结构相对简单,人工合成噬藻体、阐明其感染并杀灭蓝细菌的分子机制,有望实现对水华蓝藻的噬藻体控制,并可为人工合成更复杂的生命形式奠定理论基础和技术基础。     

中国大学-企业专利申请合作网络研究

 利用从中国国家知识产权局专利检索数据库中检索到的7736项中国大学和企业联合申请发明专利的数据,构建了中国大学-企业专利申请合作网络图,采用社会网络分析技术对专利申请合作网络的规模、密度、中心度和中心势等网络结构指标进行了测度。研究发现,1990年以来中国大学-企业专利申请合作网络的规模迅速增大;网络密度分析结果显示,各类型专利申请合作网络成员间的联系强度有所区别;企业的中心度和中心势尚未真正形成,反映出中国进一步推进产学合作的空间还很大。     

Managing the Progressive Publishing Company During Market and Technology Transitions

As new media technologies and platforms emerge and take hold in our society, traditional publishers are wondering: What’s in this new content climate for me? The simple answer is: a lot. The digital world, mobile content delivery mechanisms and the public’s increasing comfort—even preference for—a media menu from which they can pick and choose what they want and how they want to receive it, brings exciting and potentially lucrative opportunities. For publishers who understand how to leverage their brand and create authentic, identifiable value in the eyes of the customer, risk can be reduced and new revenue streams built. Here are four best practices to position your publishing company for growth.