Hepatitis B virus preS1-derived lipopeptide functionalized liposomes for targeting of hepatic cells

To enhance the liver-specific delivery, HBVpreS/2-48^myr (HBVP), a synthetic HBVpreS-derived lipopeptide endowed with compelling liver tropism, was conjugated to PEGylated liposomes (HBVP-Lip) for hepatic cell-specific delivery. Compared with the non-targeted liposomes, a significantly higher amount of HBVP-Lip were taken up by the primary mice hepatocytes through a receptor-mediated endocytosis mechanism. The endocytosis inhibition assay demonstrated that the endocytosis of HBVP-Lip was mediated mainly by caveolin and clathrin. After systemic administration in mice, HBVP-Lip could be specifically internalized into hepatocytes efficaciously. Furthermore, the hepatoprotective effects of HBVP-Lip loaded with silybin (SLB) on carbon tetrachloride induced acute liver damage were remarkably stronger than the SLB solution and SLB loaded non-targeted liposomes. Preliminary safety results suggested that no acute systemic toxicity or immunotoxicity was observed after intravenous administration with HBVP-Lip. These results indicated that the HBVP-Lip could deliver the payloads to the hepatocytes with high specificity in vitro and in vivo, and raise new possibilities for liver-specific drug delivery systems, gene delivery systems, and bio-imaging systems.     

医院感染监控系统的设计与实践

针对院内感染监测管理面临的问题,开发了一套医院感染管理监控系统软件.该系统嵌入医院HIS系统中,实现了全院范围内医院感染的前瞻性监测及环节质量控制,可及时监控耐药菌在院内的传播和流行以及抗菌药物合理应用的分线管理和围手术期用药的疗程控制.文章还对软件功能和应用效果进行了探讨,并对软件功能的进一步研发进行了展望.     

基于问题的学习共同体——大学英语教师自主发展的新视角

PBL(problem-based learning)一直是用于培养学生解决真实问题能力的学习方法或教学方法。本文在综述了与此相关的主要学习理论以及大学外语教师教育发展的一般进程后,指出一旦教师回归到学习者身份,PBL及基于问题的学习共同体就无疑可以成为适合高动机驱动的成年学习者实现自主学习、自我专业发展的有效方法。文章的新视角正在于把语言教师作为普通的学习者来研究,并探索语言教师如何在基于问题的学习共同体中,通过改进自主学习方法来实现自我专业的发展。     

Modeling the emergence of universality in color naming patterns

The empirical evidence that human color categorization exhibits some universal patterns beyond superficial discrepancies across different cultures is a major breakthrough in cognitive science. As observed in the World Color Survey (WCS), indeed, any two groups of individuals develop quite different categorization patterns, but some universal properties can be identified by a statistical analysis over a large number of populations. Here, we reproduce the WCS in a numerical model in which different populations develop independently their own categorization systems by playing elementary language games. We find that a simple perceptual constraint shared by all humans, namely the human Just Noticeable Difference (JND), is sufficient to trigger the emergence of universal patterns that unconstrained cultural interaction fails to produce. We test the results of our experiment against real data by performing the same statistical analysis proposed to quantify the universal tendencies shown in the WCS [Kay P & Regier T. (2003) Proc. Natl. Acad. Sci. USA 100: 9085-9089], and obtain an excellent quantitative agreement. This work confirms that synthetic modeling has nowadays reached the maturity to contribute significantly to the ongoing debate in cognitive science.     

口服番泻叶致变态反应1例

番泻叶是一种常见的导泻药,在医院中常把它作为肠道检查前的清肠剂,或用来为部分急性便秘病人解除便秘之苦,具有用法简单、效果可靠、病人依从性好等优点.2008年9月我科1例病人口服番泻叶后出现变态反应.现报告如下.     

Structural characterization of the tobramycin-piperacillin reaction product formed at pH 6.0

Tobramycin is an aminoglycoside antibiotic that loses a significant amount of activity in the presence of Zosyn at pH 6. As part of our investigation into ways to improve the compatibility of tobramycin with Zosyn (which contains piperacillin and tazobactam in an 8:1 ratio buffered at pH 6 by sodium citrate) by lowering the pH, we identified the reaction product of tobramycin and piperacillin at pH 6.0 and the order of the pK(a) values of tobramycin. The structure of the main reaction product of tobramycin and piperacillin at pH 6.0 was determined by 2D NMR to be the product of 3″-NH(2) reacting with the β-lactam of piperacillin. The order of the pK(a) values of the nitrogens of tobramycin was determined by (1)H and (15)N NMR titrations to be 6'-NH(2)>2'-NH(2)>1-NH(2)≈3″-NH(2)>3-NH(2). At pH 4.0, the reaction between tobramycin and Zosyn was almost negligible for a period of up to 2?h. The pH can be lowered by adding an acid such as HCl or citric acid to Zosyn to make a pH 4.0 buffer.