"提高意识"活动在大学英语精读课中的体现 --对医学护理专业学生精读课改革的重新思考

语法翻译教学法多年来一直主宰着大学英语精读课的教学。随着中国经济突飞猛进的发展,各行各业的人们与国外同行交流的机会和要求也随之增加。面对社会发展而带来的这种变化,显然,古老传统的教学方法已不能适应。通过具体详尽的理论分析,对语法翻译教学法提出了自己的看法。     

A prospective, randomized, cross-over comparison of two methods of artificial insemination by donor on the incidence of conception: intracervical insemination by straw versus cervical cap

In a prospective, randomized study of insemination with donor semen, intracervical insemination by straw was compared with insemination using a cervical cap with an intracervical reservoir. A total of 91 patients completed 486 treatment cycles. There were no significant differences in age, parity, indication for insemination by donor, or method of cycle monitoring between women who became pregnant and those who did not conceive with either insemination method. In 236 standard intracervical insemination cycles, 14 patients became pregnant (5.9% per cycle), whereas 38 patients conceived in 250 cervical cap cycles (15.2% per cycle). Both the crude pregnancy rates and the cumulative pregnancy rates calculated by the Kaplan-Meier life-table method were significantly different (chi(2)-test, P < 0.001, and log-rank test, P < 0.005 respectively). Pregnancy rates in artificial insemination with cryopreserved donor semen may be improved by the use of a cervical cap when compared to cervical insemination by straw. The use of the cervical cap may prolong the exposure of the spermatozoa to the cervical mucus and prevent the backflow of semen into the vagina.      

间接荧光抗体试验检测日本血吸虫感染家兔血清中特异性抗体水平的动态变化

用尾蚴、雌虫、雄虫和血吸虫感染兔肝组织内虫卵冰冻切片抗原进行间接荧光抗体试验（ＩＦＡＴ），观察日本血吸虫感染家兔血清中特异性抗体的动态变化。抗尾蚴、成虫（雌、雄虫）、虫卵抗体检出的最早时间分别为３ｗｋ、３ｗｋ、４ｗｋ，其抗体滴度高峰分别在感染后７ｗｋ、１０～１２ｗｋ和１０ｗｋ。以抗尾蚴抗体水平最高，抗虫卵抗体次之，抗雌、雄虫抗体较低。这为全面了解感染宿主对血吸虫各期抗原（尾蚴、雌、雄虫、虫卵）的免疫反应及免疫学诊断提供了新的资料     

家兔急性不完全性脑缺血及重灌流的实验病理研究

采用低压低灌流方法造成家兔急性不完全性脑缺血，并进行重灌流。检测了脑电图（ＥＥＧ）及大脑组织中乳酸脱氢酶（ＬＤＨ）活性，观察了大脑皮层组织形态学变化。结果发现，脑缺血时大脑ＥＥＧ明显抑制，ＬＤＨ活性升高，脑组织超微结构表现为膜结构损伤。重灌流后ＥＥＧ严重抑制，ＬＤＨ活性升高，膜结构损伤进一步加重。     

刺激强度对黑质DA能神经元伤害性反应的影响

本研究用细胞外记录方法研究大鼠黑质多巴胺能神经元伤害性反应的特点。共记录了194个多巴胺能神经元。其中,大多数神经元(78％)可被尾部强电刺激(15mA,1.0ms)所抑制,15％被兴奋。兴奋和抑制反应均依赖于刺激强度。当刺激强度变化于0～20mA时,伤害性反应强度与刺激强度的对数显著相关。来自不同部位的刺激可会聚于同一神经元。反应潜伏期和阈值提示Aδ纤维参与伤害性信息传入黑质的过程。本文还讨论了多巴胺能神经元系统在痛觉机制中的作用。     

Effect of fathers'' age and birth order on occurrence of congenital heart disease.

STUDY OBJECTIVE--The aim was to examine if there is an effect of fathers' age and of birth order on the occurrence of congenital heart disease. DESIGN--This was a hospital based case-referent study including use of birth defects surveillance data. SUBJECTS--Subjects were 497 cases of congenital heart disease aged between 3 months and 5 years, born in Beijing and Hebei Province, China; 6222 children without congenital heart disease serve as reference baseline. MEASUREMENTS AND MAIN RESULTS--With stratified analysis and logistic regression analyses, congenital heart disease was found to be associated with fathers' age less than 25 years (odds ratio 2.63), independent of mothers' age and of birth order. There was also evidence to show a higher birth order effect on the occurrence of congenital heart disease independent of parental ages. CONCLUSION--Higher birth order and fathers aged less than 25 years were both independently associated with some categories of congenital heart disease and with congenital heart disease overall.     

Nebivolol induces endothelium-dependent relaxations of canine coronary arteries.

Nebivolol is a new beta 1-antagonist that acutely reduces arterial blood pressure without depressing cardiac function. The present study was designed to determine the effect of nebivolol on coronary arteries. Rings of canine left anterior descending coronary (LAD) artery with or without endothelium were suspended in organ chambers and the isometric tension was recorded. In some experiments, the transmembrane potential of the smooth muscle cells was recorded by electrophysiological methods. During contractions to prostaglandin F2 alpha, nebivolol induced concentration-dependent relaxations of the coronary arteries. The enantiomer, l-nebivolol, also induced comparable relaxations; however, d-nebivolol induced smaller relaxations. The relaxations induced by nebivolol and its enantiomer were significantly larger in tissues with than in those without endothelium. The differences between tissues with and without endothelium were abolished by nitro-L-arginine (3 x 10(-5) M) or methylene blue (10(-5) M). The nebivolol-induced relaxations were not affected by indomethacin (10(-5) M), phentolamine (5 x 10(-6) M), propranolol (5 x 10(-6) M), or methysergide (3 x 10(-6) M). Nebivolol at a subthreshold concentration for inducing relaxation (3 x 10(-7) M) did not significantly affect endothelium-dependent relaxations to acetylcholine but potentiated ADP-induced endothelium-dependent relaxations. The potentiation is stereoselective for l-nebivolol. Nebivolol induced a small hyperpolarization of the coronary smooth muscle with endothelium (1 mV).(ABSTRACT TRUNCATED AT 250 WORDS)