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   96527篇
  免费   9358篇
  国内免费   5792篇
耳鼻咽喉   829篇
儿科学   1047篇
妇产科学   1098篇
基础医学   11918篇
口腔科学   1924篇
临床医学   12211篇
内科学   14629篇
皮肤病学   1187篇
神经病学   4831篇
特种医学   3930篇
外国民族医学   53篇
外科学   10483篇
综合类   14692篇
现状与发展   19篇
一般理论   17篇
预防医学   6457篇
眼科学   2911篇
药学   9473篇
  127篇
中国医学   5212篇
肿瘤学   8629篇
  2025年   18篇
  2024年   1252篇
  2023年   1990篇
  2022年   4034篇
  2021年   5236篇
  2020年   3812篇
  2019年   3279篇
  2018年   3448篇
  2017年   3018篇
  2016年   3045篇
  2015年   4459篇
  2014年   5540篇
  2013年   5070篇
  2012年   7641篇
  2011年   8016篇
  2010年   5122篇
  2009年   4241篇
  2008年   5333篇
  2007年   5138篇
  2006年   4961篇
  2005年   4380篇
  2004年   3170篇
  2003年   2837篇
  2002年   2436篇
  2001年   2020篇
  2000年   1999篇
  1999年   1961篇
  1998年   1159篇
  1997年   1155篇
  1996年   899篇
  1995年   764篇
  1994年   677篇
  1993年   438篇
  1992年   568篇
  1991年   435篇
  1990年   364篇
  1989年   380篇
  1988年   280篇
  1987年   271篇
  1986年   165篇
  1985年   160篇
  1984年   97篇
  1983年   80篇
  1982年   48篇
  1981年   50篇
  1980年   32篇
  1979年   49篇
  1978年   22篇
  1974年   18篇
  1973年   15篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
Several hormones, neurotransmitters, and neuropeptides were screened for the ability to stimulate inositol phosphate formation in cultured human retinal epithelial (RPE) cells. Carbachol, vasopressin and thrombin were found to be effective. Treatment of RPE cells with all three agents produced increases in inositol monophosphate, inositol bisphosphate and inositol trisphosphate in the presence of 10 mM LiCl. Carbachol stimulated a 4-fold increase in the total of inositol phosphates at 1 mM. Studies with cholinergic antagonists showed a rank order of 4 DAMP greater than QNX greater than pirenzepine greater than methoctramine, suggesting the presence of M3 muscarinic receptors. Vasopressin gave a 2.5-fold stimulation at 10 microM. Agonists of vasopressin were also tested and gave differential responses. Studies using a V1 agonist (PIOVP) and a V2 agonist (DAVP) showed DAVP matching the level of stimulation elicited by vasopressin whereas treatment with PIOVP only reached 50% of the vasopressin response. These data suggested the presence of V2 receptors in the RPE cells. Several proteases were tested for their ability to stimulate RPE inositol phosphates. Thrombin caused a 7-fold increase in inositol phosphate formation at 1 U/ml, whereas trypsin and plasmin elicited smaller responses (approximately 2-fold). The thrombin effect was blocked by the thrombin-specific inhibitor, hirudin, but not by other protease inhibitors. Several mediators of inflammation such as bradykinin, histamine and serotonin were also tested, and they were ineffective in stimulating inositol phosphate turnover in the RPE cells.  相似文献   
52.
宋朝估  刘文彦 《针刺研究》1992,17(3):171-174
<正> 8-精-催产素(8-arginine-vasotocin,AVT)又名管催产素,是松果体分泌的九肽激素,其环状结构部分与催产素(oxytocin,OT)相同,直链部分与精氨酸加压素(Argi-  相似文献   
53.
Announcement     
The name of one of the contributing authors to this paper was omitted from the list of authors that appeared on page 373. The correct list of authors and affiliations are printed below:  相似文献   
54.
Myocardial abscess is usually resulted from the septicemia ofvarious microorganisms such as Candida, Staphylococcus, Aspergillus,Streptococcus, and Salmonella species. Since  相似文献   
55.
56.
57.
Objective: To explore the therapeutic methods, surgical indications and clinical practice of minimally invasive surgery on traumatic epidural hematoma (EDH). Methods: Retrospective study was made on 135 patients with traumatic EDH admitted into our hospital from June 2002 to August 2005. Sixty-five patients were treated with mini-invasive negative pressure drainage (treatment group), 70 patients with comparable condition used traditional craniotomy (control group ). The mean time of operation, average days in hospital, expenditure and prognosis of two groups were recorded and analyzed. Results: There was no significant difference in therapeutic efficacy between two groups. Patients in treatment group had a shorter hospital stay and less expenditure than those in control group. Conclusion: Mini-invasive negative pressure drainage is simple, effective, economical and applicable to some traumatic EDH patients.  相似文献   
58.
This study was undertaken to compare the clinical and radiological results achieved using navigation-assisted minimally invasive surgery (NA-MIS) and conventional (CON) techniques in 42 bilateral total knee arthroplasty (TKA) patients with a minimum follow-up of one year. Clinical evaluations were performed using range of motion (ROM), Hospital for Special Surgery (HSS) scores, and Western Ontario and McMaster University (WOMAC) scores (pain, functional, and total) at 3, 6 and 9 months and one year postoperatively. Patients' subjective preferences and radiological indices, including mechanical axis and coronal inclinations of the prostheses, were compared at one year postoperatively. NA-MIS TKA yielded better HSS and WOMAC total scores than CON TKA up to six months, and a better WOMAC pain score up to 9 months. However, these differences were not significant at one year postoperatively. ROM was comparable in both groups at all times, but more patients preferred the NA-MIS side to the CON side. Radiological results showed no differences in mean values between the two surgical groups, although the NA-MIS group contained fewer outliers than the CON group. In conclusion, NA-MIS TKA was associated with better clinical results up to 6 or 9 months after surgery, giving more accurate leg alignment than CON TKA.  相似文献   
59.
Although breast milk is recommended as the optimal source of infant nutrition, breastfeeding initiation is below recommended levels, especially among teenage mothers. Breastfeeding initiation rates among Michigan (US) teenage mothers (12-19 y) were compared by demographics and health behaviors. Multivariate analyses determined which factors were significant independent predictors of breastfeeding initiation among teenage mothers enrolled prenatally in the Michigan Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) program in 1995. Significant predictors independently associated with breastfeeding initiation were race/ethnicity, education, marital status, postpartum anemia status, parity, prenatal trimester of WIC enrollment, and smoking. The strongest predictor of breastfeeding initiation differed for white mothers (positive predictor: education beyond high school [OR = 3.13]) and black mothers (negative predictor: multiparous [OR = 0.25]). Initiation rates for this population of teenage mothers fall below the national average for mothers of all ages and the US Healthy People 2010 goals. Research is needed concerning how breastfeeding support and education can be improved to reach the US national health goals.  相似文献   
60.
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