研究性学习——创新教育的重要途径

阐述了研究性学习的基本概念、实质,提出了在研究性学习中学校、教师和学生应扮演的角色,论述了研究性学习和创新教育的关系及其对社会的推动力。     

同时学习原则在临床护理教学中的应用

临床是护生将理论知识应用于实践场所，也是他们走上工作岗位前关键的必要准备。随着社会的发展和医疗改革的施行，培养高素质全面发展的护理人员成为迫在眉睫的事情。本文针对此问题，运用同时学习原则，对提高临床实习护生的水平提出了具体的策略。     

Telomeric (TTAGGG)n Sequences Are Associated With Nucleolus Organizer Regions (NORs) in the Wood Lemming

The distribution of the (TTAGGG)_n telomeric sequence was studied in chromosomes of the wood lemming, Myopus schisticolor, by fluorescence in-situ hybridization. As expected, the hybridization signals were observed at telomeres of all chromosomes. However, quite a number of interstitial telomeric sites were present in the pericentric heterochromatic regions. Consistent strong hybridization signals were also seen at one terminus of chromosomes 5, 7 and 12–15. By post-hybridization G-banding and silver-staining, the large blocks of the telomeric sequences on chromosomes 5 and 12 were localized to nucleolus organizer regions (NORs). This revised version was published online in August 2006 with corrections to the Cover Date.     

XY Sex Reversal in the Wood Lemming is Associated with Deletion of Xp21–23 as Revealed by Chromosome Microdissection and Fluorescence in situ Hybridization

In the wood lemming (Myopus schisticolor), XY sex reversal occurs naturally because of the presence of an X chromosome variant designated X*. The two types of X chromosome, X and X*, can be distinguished by G-banding, and analyses have demonstrated complex rearrangements of the short arm of X*. Here, chromosomal microdissection, degenerate oligonucleotide-primed polymerase chain reaction (DOP-PCR) and fluorescence in situ hybridization (FISH) techniques have been used to generate and map DNA probes for different parts of the X and X* chromosomes. The results showed that the region of Xp21–23 is deleted from the X* and some of the deleted DNA sequences are homologous to the mouse gamma-satellite. The deletion must be associated with the sex reversal in this species. FISH experiments with dissected probes of X and distal half of Xq provided evidence for presence of homologous sequences between large regions of the X and Y chromosomes, including euchromatic and heterochromatic parts of the sex chromosomes. The findings of this study will be of significance for further cloning of important candidate gene(s) responsible for the XY sex reversal.