首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   129294篇
  免费   7003篇
  国内免费   178篇
耳鼻咽喉   1893篇
儿科学   5507篇
妇产科学   4259篇
基础医学   17948篇
口腔科学   3176篇
临床医学   9749篇
内科学   24766篇
皮肤病学   3585篇
神经病学   9933篇
特种医学   5659篇
外国民族医学   48篇
外科学   20781篇
综合类   1723篇
一般理论   35篇
预防医学   7093篇
眼科学   3554篇
药学   8943篇
中国医学   343篇
肿瘤学   7480篇
  2018年   1135篇
  2017年   928篇
  2016年   1320篇
  2015年   1460篇
  2014年   1919篇
  2013年   2802篇
  2012年   3694篇
  2011年   3740篇
  2010年   2308篇
  2009年   2278篇
  2008年   3818篇
  2007年   4047篇
  2006年   4191篇
  2005年   4281篇
  2004年   4208篇
  2003年   4090篇
  2002年   4008篇
  2001年   7495篇
  2000年   7479篇
  1999年   6321篇
  1998年   1810篇
  1997年   1706篇
  1996年   1481篇
  1995年   1327篇
  1994年   1201篇
  1993年   1231篇
  1992年   4112篇
  1991年   3869篇
  1990年   3843篇
  1989年   3595篇
  1988年   3245篇
  1987年   3114篇
  1986年   3058篇
  1985年   2845篇
  1984年   2128篇
  1983年   1762篇
  1982年   1023篇
  1981年   1006篇
  1980年   861篇
  1979年   1966篇
  1978年   1451篇
  1977年   1205篇
  1976年   1005篇
  1975年   1260篇
  1974年   1313篇
  1973年   1306篇
  1972年   1110篇
  1971年   1059篇
  1970年   940篇
  1969年   839篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
41.
A case of testicular cancer in 2 brothers is reported and a review of the literature about testicular malignancies and etiologic factors in closely related family members is given. The familial incidence of testicular tumor is found to be 3% in twins and 0.6-2.1% in less closely related men. Tumors were of the same histology in 70-77% of the twins, whereas in brothers and in other degrees of relationship tumors of different histology mostly occur. Following the diagnosis of the tumor in the first man, the average interval to presentation of the tumor in the relative was 3.7 years in twins, 7.7 years in nontwin brothers and 13.5 years for less closely related men. The need for a thorough checkup of other family members is advised.  相似文献   
42.
This study compares the weight of the human brain to gestational age and body dimensions. A new formula for calculating the rate of growth is proposed. It consists of a second order polynomial function: Y = A0 + A1X + A2X2, in which Y is brain weight, body weight, height, or body surface area; X is gestational age in weeks and A0, A1, and A2 are statistically estimated coefficients. In utero, the growth rate is most rapid for body weight, followed in decreasing order by brain weight, body surface area, and height. Brain growth is the same for both sexes in black and white races; it accelerates between the 20th and 45th weeks of gestation. The size of the newborn infant brain is directly related to gestational age and body size and is not determined by sex or race.  相似文献   
43.
Interest in inguinal hernia surgery has increased significantly with the introduction of new operating techniques during the past decade. This multicenter study compared short-term results in patients treated by the laparoscopic transabdominal preperitoneal patch technique (TAPP; n=518) and the Shouldice technique (n=524). We evaluated demographics, operative data, complications, hospital stay, postoperative pain, use of analgesics, functional status, sick leave, and complaints up to 3 months postoperatively. The median operating time was shorter in the Shouldice group (55 vs. 65 min), but there were no significant differences in complication rates, and major complications were rare. The hospital stay was 1 day or less in over 98% of cases in both groups, but more operations were performed on outpatient basis in the Shouldice group. In the TAPP group postoperative pain and analgesic consumption were less, postoperative functional status was better, and sick leave was shorter (10 vs. 14 days). These results show that the two methods are equally safe and have few major complications. The TAPP operation is associated with less postoperative pain, better postoperative functional status, and shorter sick leave, but at the price of a longer operating time. Electronic Publication  相似文献   
44.
45.
In 50 children, 4 months to 12 years of age, with minor head trauma non-target visual event-related potentials were performed and compared to a second registration of the potentials some months later. On following-up there was a clear tendency for a relative improvement of the latencies of the endogenous potentials. In this way non-target visual event-related potentials proved to be of value in the investigation of mental impairment in early childhood.  相似文献   
46.
Trypsin and Zymosan induce an increase in respiration activity of cultivated endothelial cells. These effects are not due to the production of oxygen radicals. The effect of trypsin will be explained by interfering with the cellular homeostasis of calcium. The stimulated respiration after incubation with zymosan may be connected with the increased phagocytosis.  相似文献   
47.
48.
Conformationally restricted analogues of the selective partial muscarinic agonist N-methyl-N-(1-methyl-4-pyrrolidino-2-butynyl)acetamide (BM 5; 2) were synthesized. The compounds were tested for muscarinic and antimuscarinic activity in the isolated guinea pig ileum and in intact mice. They were found to be moderately potent muscarinic antagonists or weak partial agonists. The new compounds were less potent than 2 in inhibiting (-)-[3H]-N-methylscopolamine binding in the rate cerebral cortex. Thus, structural modifications of 2 in which part of the amide moiety has been connected with the methyl group in the butynyl chain to form a five-membered ring decrease affinity and in most cases abolish efficacy.  相似文献   
49.
50.
The duodenal contents were examined in 81 patients with gastroduodenal ulcer. Bile acid concentrations, alkaline phosphatase activity, and sodium ion concentration were measured for the detection of duodenogastric reflux. Measurements of sodium ion concentration permitted estimation of the immediate volume of the duodenogastric reflux in the gastric contents. No methods for duodenogastric reflux detection should be given preference in examinations of peptic ulcer patients. Multiple-modality studies appear to be the most effective.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号