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   2391894篇
  免费   182533篇
  国内免费   4595篇
耳鼻咽喉   31757篇
儿科学   78858篇
妇产科学   68019篇
基础医学   348065篇
口腔科学   66128篇
临床医学   220315篇
内科学   468776篇
皮肤病学   53609篇
神经病学   194962篇
特种医学   89755篇
外国民族医学   702篇
外科学   347625篇
综合类   53634篇
现状与发展   4篇
一般理论   973篇
预防医学   193863篇
眼科学   54467篇
药学   171672篇
  7篇
中国医学   4906篇
肿瘤学   130925篇
  2019年   19197篇
  2018年   26494篇
  2017年   20247篇
  2016年   22589篇
  2015年   25526篇
  2014年   35949篇
  2013年   54296篇
  2012年   73595篇
  2011年   78485篇
  2010年   45952篇
  2009年   44004篇
  2008年   73191篇
  2007年   77985篇
  2006年   78006篇
  2005年   75943篇
  2004年   72920篇
  2003年   69644篇
  2002年   67443篇
  2001年   111883篇
  2000年   114229篇
  1999年   95382篇
  1998年   27154篇
  1997年   24637篇
  1996年   24965篇
  1995年   23688篇
  1994年   21771篇
  1993年   20365篇
  1992年   73839篇
  1991年   71700篇
  1990年   69070篇
  1989年   66522篇
  1988年   61332篇
  1987年   59969篇
  1986年   56563篇
  1985年   53753篇
  1984年   41012篇
  1983年   35279篇
  1982年   21194篇
  1981年   19187篇
  1979年   37636篇
  1978年   27192篇
  1977年   22661篇
  1976年   21215篇
  1975年   22324篇
  1974年   27128篇
  1973年   26456篇
  1972年   24944篇
  1971年   22983篇
  1970年   21720篇
  1969年   20361篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
11.
Heart Failure Reviews - The nitric oxide (NO)–guanylate cyclase (GC)–cyclic guanosine monophosphate (cGMP) pathway plays an important role in cardiovascular, pulmonary and renal...  相似文献   
12.
Comprehensive evidence regarding the treatment of non-anaemic iron deficiency in patients undergoing valvular heart surgery is lacking. This study aimed to investigate the association between non-anaemic iron deficiency and postoperative outcomes in these patients. We retrospectively analysed 321 patients of which 180 (56%) had iron deficiency (defined as serum ferritin < 100 ng.ml-1 or < 300 ng.ml-1 with transferrin saturation < 20%). While the iron-deficient group had lower pre-operative haemoglobin levels than the non-iron deficient group (median (IQR [range]) 134 (127–141 [120–172]) g.l-1, 143 (133–150 [120–179]) g.l-1, p = 0.001), there was no between-group difference in allogeneic red blood cell transfusion. Median (IQR [range]) days alive and out of hospital at postoperative day 90 was 1 day shorter in the iron-deficient group (80 (77–82 [9–85]) days vs. 81 (79–83 [0–85]) days, p = 0.026). In multivariable analysis, only cardiopulmonary bypass duration (p = 0.032) and intra-operative allogeneic red blood cell transfusion (p = 0.011) were significantly associated with reduced days alive and out of hospital at postoperative day 90. Iron deficiency did not exert any adverse influence on secondary outcomes except length of hospital stay. Our findings indicate that non-anaemic iron deficiency alone is not associated with adverse effects in patients undergoing valvular heart surgery when it does not translate into an increased risk of allogeneic transfusion.  相似文献   
13.
Cancer Causes & Control - Congenital malformations are strong risk factors for childhood cancer. Our objective was to determine whether cancer survival differs by birth defect status among...  相似文献   
14.
15.
Journal of Neuro-Oncology - Adjuvant radiation is often used in patients with low grade gliomas with high-risk characteristics with a recommended dose of 45–54&nbsp;Gy. We used the...  相似文献   
16.
Maternal and Child Health Journal - Early life exposures can have an impact on a child’s developmental trajectory and children born late preterm (34–36&nbsp;weeks gestational age)...  相似文献   
17.
BackgroundThe aim of this study was to estimate the prevalence of dental prosthetic treatment and to investigate the demographic, social, economic and medical factors associated with the use of fixed and removable dentures in a representative sample of adults living in France.MethodsThe data were obtained from the 2002–2003 Decennial Health Survey, a cross-sectional study of a representative sample of the population living in France, which included 29,679 adults. Information was collected by interview. The variables collected were fixed denture, removable denture, age, gender, number of children, area of residence, nationality, educational attainment, family social status, employment status, annual household income per capita, supplementary insurance, chronic disease, eyesight problems/glasses, hearing problems/hearing aids. Multinomial logistic regression models were used to study the relationship between prosthetic treatment and demographic, socioeconomic and medical characteristics unadjusted, adjusted for age and adjusted for all the characteristics.ResultsThe prevalence of prosthetic treatment was 34.6% (95% confidence interval (CI): [34.1; 35.2]) for fixed prosthetic dentures and 13.8% (95% CI: [13.4; 14.2]) for removable prosthetic dentures. We showed a gradient between educational attainment and removable dentures; the odds ratio adjusted for all the variables (aOR) associated with no or primary education compared to post-secondary education was 2.56; 95% CI: [2.09; 3.13]. When annual household income per capita was low, subjects were less likely to report fixed dentures (aOR = 0.68; 95% CI: [0.62; 0.75]) than those with high annual household income per capita. Individuals without insurance less often reported fixed dentures than those with private insurance. Those reporting chronic disease were less likely to report fixed dentures (aOR = 0.87; 95% CI: [0.79; 0.95]) but more likely to report removable dentures (aOR = 1.29; 95% CI: [1.17; 1.43]) than those without chronic disease.ConclusionThis study reveals social, economic and medical inequalities in fixed and removable prosthetic treatment among adults in France.  相似文献   
18.
19.
20.
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