In vitro study on ribozyme against hepatitis C virus

Objective: To determine the effective nucleotide sites of ribozymes against HCV, and obtain a highly effective, nontoxic and inexpensive antisense ribozyme specific for HCV. Methods: Two effective ribozymes, targeted to HCV 5’NC region and C region, were designed and synthesized. Eukaryotic expression vectors, pSV2-gpt. CD-SR (, containing either HCRZNC or HCRZC were constructued and transfected into MT-2 cells, which had been infected by HCV. Quantitative PCR and hydridization were used to determine the effect of inhibition of HCV by ribozymes. Results: HCRZNC and HCRZC suppressed the replication of HCV by 54.7% and 62.1%, respectively. Furthermore, when both ribozymes were cotransfected into cells, they suppressed replication by 78.8%. Conclusion: Two specific antisense ribozymes have strong inhibitory effects on the replication of HCV in cultured cells, and have better effect when used together.     

Learning organic chemistry through natural products

Chemical methods to determine the conformations and absolute configurations of menthol, a cyclohexane derivative with 3 chiral centres, are described.     

Learning organic chemistry through natural products

Some interesting examples of the linkage between the structure and biological function of secondary metabolites in plants and animals are described.     

Understanding student pathways in context-rich problems

This paper describes the ways that students’ problem-solving behaviors evolve when solving multi-faceted, context-rich problems within a web-based learning environment. During the semester, groups of two or three students worked on five physics problems that required drawing on more than one concept and, hence, could not be readily solved with simple “plug-and-chug” strategies. The problems were presented to students in a data-rich, online problem-based learning environment that tracked which information items were selected by students as they attempted to solve the problem. The students also completed a variety of tasks, like entering an initial qualitative analysis of the problem into an online form. Students were not constrained to complete these tasks in any specific order. As they gained more experience in solving context-rich physics problems, student groups showed some progression towards expert-like behavior as they completed qualitative analysis earlier and were more selective in their perusal of informational resources. However, there was room for more improvement as approximately half of the groups still completed the qualitative analysis task towards the end of the problem-solving process rather than at the beginning of the task when it would have been most useful to their work.     

Classroom environments that foster a disposition for critical thinking

In this article, we examine the disposition for critical thinking (CT) from three perspectives and analyse the underlying constructs of the disposition for CT, such as one’s ability, sensitivity and inclination to engage in critical, mindful thought. Environmental factors that enhance or inhibit the development of a generalisable disposition for critical thought are discussed. Finally, we present a set of empirically-verified classroom practices that can help to foster a disposition for CT.