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   198901篇
  免费   46520篇
  国内免费   1188篇
耳鼻咽喉   2281篇
儿科学   6442篇
妇产科学   1416篇
基础医学   35005篇
口腔科学   10436篇
临床医学   20804篇
内科学   43529篇
皮肤病学   6146篇
神经病学   24170篇
特种医学   8178篇
外国民族医学   5篇
外科学   28895篇
综合类   6163篇
现状与发展   3篇
一般理论   13篇
预防医学   14525篇
眼科学   2988篇
药学   15298篇
  20篇
中国医学   4676篇
肿瘤学   15616篇
  2023年   1270篇
  2022年   2006篇
  2021年   5133篇
  2020年   8366篇
  2019年   17592篇
  2018年   17344篇
  2017年   16095篇
  2016年   12634篇
  2015年   12477篇
  2014年   13767篇
  2013年   14006篇
  2012年   12317篇
  2011年   12615篇
  2010年   10949篇
  2009年   7148篇
  2008年   7905篇
  2007年   6232篇
  2006年   5817篇
  2005年   5426篇
  2004年   5110篇
  2003年   4806篇
  2002年   4235篇
  2001年   3489篇
  2000年   2213篇
  1999年   1036篇
  1998年   671篇
  1997年   684篇
  1996年   567篇
  1995年   544篇
  1994年   496篇
  1993年   440篇
  1992年   396篇
  1991年   359篇
  1990年   285篇
  1989年   269篇
  1988年   256篇
  1987年   203篇
  1985年   3021篇
  1984年   3546篇
  1983年   2961篇
  1982年   3455篇
  1981年   3139篇
  1980年   2599篇
  1979年   2564篇
  1978年   2094篇
  1977年   1577篇
  1976年   2020篇
  1975年   1524篇
  1974年   1330篇
  1973年   1280篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
《Cancer cell》2022,40(3):318-334.e9
  1. Download : Download high-res image (268KB)
  2. Download : Download full-size image
  相似文献   
2.
3.
4.
5.
6.
The coronavirus disease 2019 (COVID-19) pandemic has rapidly created widespread impacts on global health and the economy. Data suggest that women are less susceptible to severe illness. However, sex-disaggregated data are incomplete, leaving room for misinterpretation, and focusing only on biologic sex underestimates the gendered impact of the pandemic on women. This narrative review summarizes what is known about gender disparities during the COVID-19 pandemic and the economic, domestic, and health burdens along with overlapping vulnerabilities related to the pandemic. In addition, this review outlines recommended strategies that advocacy groups, community leaders, and policymakers should implement to mitigate the widening gender disparities related to COVID-19.  相似文献   
7.
PurposeThe purpose of this study was to make a systematic review and meta-analysis to determine the stent diameter (8 mm vs. 10 mm) that conveys better safety and clinical efficacy for transjugular intrahepatic portosystemic shunt (TIPS).Materials and methodsFour databases were used to identify clinical trials published from inception until March 2020. Data were extracted to estimate and compare one-year and three-year overall survivals, hepatic encephalopathy, variceal rebleeding, and shunt dysfunction rates between patients with 8 mm covered stents and those with 10 mm covered stents.ResultsFive eligible studies were selected, which included 489 patients (316 men, 173 women). The 8 mm covered stent group had higher efficacy regarding one-year or three-year overall survival (odds ratio [OR], 2.88; P = 0.003) and (OR, 1.81; P = 0.04) and lower hepatic encephalopathy (OR, 0.69; P = 0.04) compared with 10 mm covered stent group. There were no significant differences in variceal rebleeding rate (OR 0.80; P = 0.67). However, shunt dysfunction was lower in 10 mm covered stent group (OR, 2.26; P = 0.003).ConclusionsOur results suggest that the use of 8 mm covered stents should be preferred to that of 10 mm covered stents for TIPS placement when portal pressure is frequently monitored.  相似文献   
8.
9.
PurposeTo review and to compare indirectly the outcomes of minimally invasive therapies for the treatment of lower urinary tract symptoms secondary to benign prostatic hyperplasia.Materials and MethodsA literature search via Medline and Cochrane Central databases was completed for randomized control studies published between January 2000 to April 2020 for the following therapies: Rezum, Urolift, Aquablation, and prostatic artery embolization (PAE). Data on the following variables were included: International prostate symptom score (IPSS), maximum urinary flow rate, quality of life, and postvoid residual (PVR). Standard mean differences between treatments were compared through a meta-analysis using transurethral resection of the prostate (TURP) to assess differences in treatment effect.ResultsThere was no significant difference in outcomes between therapies for IPSS at the 3, 6, and 12-month follow ups. Although outcomes for Rezum were only available out to 3 months, there were no consistently significant differences in outcomes when comparing Aquablation versus PAE versus Rezum. TURP PVR was significantly better than Urolift at 3, 6, and 12 months. No significant differences in minor or major adverse events were noted.ConclusionAlthough significant differences in outcomes were limited, Aquablation and PAE were the most durable at 12 months. PAE has been well studied on multiple randomized control trials with minimal adverse events while Aquablation has limited high quality data and has been associated with bleeding-related complications.  相似文献   
10.
ObjectiveNew-onset postoperative atrial fibrillation (POAF) after cardiac surgery is common, with rates up to 60%. POAF has been associated with early and late stroke, but its association with other cardiovascular outcomes is less known. The objective was to perform a meta-analysis of the studies reporting the association of POAF with perioperative and long-term outcomes in patients with cardiac surgery.MethodsWe performed a systematic review and a meta-analysis of studies that presented outcomes for cardiac surgery on the basis of the presence or absence of POAF. MEDLINE, EMBASE, and the Cochrane Library were assessed; 57 studies (246,340 patients) were selected. Perioperative mortality was the primary outcome. Inverse variance method and random model were performed. Leave-one-out analysis, subgroup analyses, and metaregression were conducted.ResultsPOAF was associated with perioperative mortality (odds ratio [OR], 1.92; 95% confidence interval [CI], 1.58-2.33), perioperative stroke (OR, 2.17; 95% CI, 1.90-2.49), perioperative myocardial infarction (OR, 1.28; 95% CI, 1.06-1.54), perioperative acute renal failure (OR, 2.74; 95% CI, 2.42-3.11), hospital (standardized mean difference, 0.80; 95% CI, 0.53-1.07) and intensive care unit stay (standardized mean difference, 0.55; 95% CI, 0.24-0.86), long-term mortality (incidence rate ratio [IRR], 1.54; 95% CI, 1.40-1.69), long-term stroke (IRR, 1.33; 95% CI, 1.21-1.46), and longstanding persistent atrial fibrillation (IRR, 4.73; 95% CI, 3.36-6.66).ConclusionsThe results suggest that POAF after cardiac surgery is associated with an increased occurrence of most short- and long-term cardiovascular adverse events. However, the causality of this association remains to be established.  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