RESUMO
In order to understand the students'knowledge mastery,assess teaching effects and improve the quality of teaching,this article analyzed the test papers of Neurology among the five-year program clinical medicine students of Grade 2006 in our College.The results indicated that the mean score of the exam was 87.29 with a standard deviation of 7.90.The distribution was negatively skewed.The degree of difficulty was 0.78 and the discrimination is 0.19.The reliability was 0.59.It demonstrated that the test papers had a good reliability,the design of the test papers was too easy and could not reasonablely discriminate the degree in evaluating the students'mastery of the course.Therefore,we shoud pay attention to appropriate difficulty and ensare quality in preparing test papers to scientifically evaluate teaching quality.
RESUMO
Rotating wall vessel (RWV) was used for the ex-vivo expansion of umbilical cord blood stem cells to meet the requirement of clinical application in the aspect of quantity and quality of the stem cells. The mononuclear cells (MNCs) from umbilical cord blood were cultured in T-flasks for 24 h, and then inoculated in RWV to culture for 200 h. The nucleated-cell numbers, pH and osmolality of the culture medium were determined every 24 h. The CD34+ cells content was measured and CFU-GM culture was carried out at 144 h and 197 h. Nucleated cells (NC) and CD34+ cells had a 435.5 +/- 87.6 fold expansion and a 32.7 +/- 15.6 fold expansion respectively in 197 h, and CFU-GM (colony-forming unit-granulocyte/macrophage) cells had a 21.7 +/- 4.9 fold expansion. In the whole course of culture, the pH and osmolality of the medium in the RWV were kept in the optimal hematopoietic stem cells' expansion conditions. pH was kept from 7.2 to 7.4, and the osmolality was kept from 290 mmol/kg to 310 mmol/kg. Owing to its structural particularity, the RWV could ensure cells to grow in the suspension state, could simulate the micro-environment of umbilical cord blood, and thus could make the hematopoietic stem cells expand largely in the RWV in short time.