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   57478篇
  免费   2832篇
  国内免费   533篇
耳鼻咽喉   351篇
儿科学   829篇
妇产科学   1465篇
基础医学   7618篇
口腔科学   1751篇
临床医学   6966篇
内科学   7495篇
皮肤病学   666篇
神经病学   4991篇
特种医学   4584篇
外国民族医学   2篇
外科学   6530篇
综合类   2105篇
现状与发展   8篇
一般理论   7篇
预防医学   5456篇
眼科学   744篇
药学   4679篇
  16篇
中国医学   957篇
肿瘤学   3623篇
  2024年   54篇
  2023年   3463篇
  2022年   4926篇
  2021年   4348篇
  2020年   4631篇
  2019年   2717篇
  2018年   2308篇
  2017年   2912篇
  2016年   2839篇
  2015年   2811篇
  2014年   5084篇
  2013年   3186篇
  2012年   2309篇
  2011年   1789篇
  2010年   3155篇
  2009年   2963篇
  2008年   1057篇
  2007年   1400篇
  2006年   1136篇
  2005年   795篇
  2004年   695篇
  2003年   768篇
  2002年   720篇
  2001年   719篇
  2000年   502篇
  1999年   730篇
  1998年   761篇
  1997年   571篇
  1996年   686篇
  1995年   94篇
  1994年   67篇
  1993年   79篇
  1992年   88篇
  1991年   51篇
  1990年   56篇
  1989年   29篇
  1988年   31篇
  1987年   22篇
  1986年   21篇
  1985年   25篇
  1984年   38篇
  1983年   29篇
  1982年   21篇
  1981年   19篇
  1980年   16篇
  1979年   21篇
  1978年   26篇
  1977年   15篇
  1976年   18篇
  1973年   8篇
排序方式: 共有10000条查询结果,搜索用时 312 毫秒
1.
2.
  1. Download : Download high-res image (173KB)
  2. Download : Download full-size image
  相似文献   
3.
4.
5.
6.
《Clinical therapeutics》2022,44(3):403-417.e6
PurposeEntecavir (ETV) and tenofovir disoproxil fumarate (TDF) are both recommended as first-line treatments for patients with chronic hepatitis B virus (CHB) infection according to international HBV treatment guidelines. However, recent studies reported conflicting results regarding the preferred antiviral in the prevention of hepatocellular carcinoma (HCC). This cohort study aimed to investigate this issue by using Taiwan's National Health Insurance Research Database, wherein a “finite” but not life-long treatment policy was applied.MethodsFrom January 2008 to December 2013, a total of 12,388 consecutive adult patients with CHB who received a finite course of TDF treatment (n = 1250) or ETV treatment (n = 11,138) were analyzed through screening for study eligibility followed by the 1:4 propensity score matching method.FindingsIn the entire cohort, the annual incidence and survival between the ETV and TDF groups were not significantly different regarding HCC occurrence (2.05 vs 2.74 per 100 patient-years [PY]; P = 0.055; hazard ratio [HR], 0.975; log-rank, P = 0.966), cirrhosis-related complications (1.9 vs 2.4 per 100 PY; P = 0.149; HR, 0.869; log-rank, P = 0.388), or all-cause mortality (2.16 vs 1.6 per 100 PY; P = 0.119; HR, 0.831; log-rank, P = 0.342), respectively. Propensity score matching analyses yielded similar results regarding HCC occurrence, cirrhosis-related complications, and all-cause mortality. In addition, these findings were consistently reproduced in the subgroups of patients with chronic hepatitis and cirrhosis that developed before antiviral treatment.ImplicationsETV and TDF did not significantly differ in prevention of HCC occurrence or reduction of cirrhosis-related complications and all-cause mortality in patients with CHB receiving a finite period of treatment.  相似文献   
7.
8.
9.
In forensic medicine, although various alcohols have been reported as indicators of decomposition in collected blood, no studies have examined short-chain fatty acids as indicators. In this study, the blood n-butyric acid concentration was quantified, and the association between n-butyric acid and decomposition was investigated to determine whether the detection of n-butyric acid could be a new indicator of decomposition. Among the forensic autopsies performed from 2016 to 2018 in our laboratory, the cases were divided into decomposed (n = 20) and non-decomposed (n = 20) groups based on macroscopic findings. Blood samples collected at the time of autopsy were derivatized with 3-nitrophenylhydrazine hydrochloride after solid-phase extraction. The n-butyric acid concentration was measured using liquid chromatography–tandem mass spectrometry. In addition, ethanol and n-propanol were measured using a gas chromatography-flame ionization detector. There was a significant difference (p < 0.01) in the concentrations of n-butyric acid between the decomposed and non-decomposed groups (0.343 ± 0.259 [0.030–0.973] and 0.003 ± 0.002 [0.001–0.007] mg/mL, respectively). In the decomposed group, n-butyric acid was detected at high concentrations, even in cases where n-propanol was low. These results suggest that n-butyric acid is more likely to be an indicator of blood decomposition than n-propanol.  相似文献   
10.
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