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   25368篇
  免费   1725篇
  国内免费   752篇
耳鼻咽喉   715篇
儿科学   405篇
妇产科学   310篇
基础医学   5431篇
口腔科学   1078篇
临床医学   1664篇
内科学   2637篇
皮肤病学   338篇
神经病学   1466篇
特种医学   701篇
外国民族医学   2篇
外科学   3196篇
综合类   3687篇
一般理论   1篇
预防医学   865篇
眼科学   1823篇
药学   2221篇
  18篇
中国医学   718篇
肿瘤学   569篇
  2023年   308篇
  2022年   455篇
  2021年   793篇
  2020年   804篇
  2019年   688篇
  2018年   662篇
  2017年   681篇
  2016年   587篇
  2015年   704篇
  2014年   1226篇
  2013年   1382篇
  2012年   1172篇
  2011年   1307篇
  2010年   1213篇
  2009年   1184篇
  2008年   1235篇
  2007年   1299篇
  2006年   1145篇
  2005年   1182篇
  2004年   1017篇
  2003年   939篇
  2002年   758篇
  2001年   677篇
  2000年   530篇
  1999年   558篇
  1998年   494篇
  1997年   438篇
  1996年   339篇
  1995年   359篇
  1994年   343篇
  1993年   269篇
  1992年   302篇
  1991年   262篇
  1990年   249篇
  1989年   241篇
  1988年   227篇
  1987年   200篇
  1986年   173篇
  1985年   259篇
  1984年   198篇
  1983年   148篇
  1982年   185篇
  1981年   153篇
  1980年   132篇
  1979年   89篇
  1978年   73篇
  1977年   67篇
  1976年   46篇
  1975年   22篇
  1973年   18篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
1.
2.
3.
BackgroundRacial disparities in extracorporeal membrane oxygenation (ECMO) outcomes in patients with a broad set of indications are not well documented.MethodsAdults requiring ECMO were identified in the 2016–2019 National Inpatient Sample. Patient and hospital characteristics, including mortality, clinical outcomes, and resource utilization were analyzed using multivariable regressions.ResultsOf 43,190 adult ECMO patients, 67.8% were classified as White, 18.1% Black, and 10.4% Hispanic. Although mortality for Whites declined from 47.5 to 41.0% (P = 0.002), it remained steady for others. Compared to White, Asian/Pacific Islander (PI) race was linked to increased odds of mortalty (AOR = 1.4, 95% CI = 1.1–2.0). Black race was associated with increased odds of acute kidney injury (AOR = 1.4, 95%-CI: 1.2–1.7), while Hispanic race was linked to neurologic complications (AOR 21.6; 95% CI 1.2–2.3). Black and Hispanic race were also associated with increased incremental costs.ConclusionsRace-based disparities in ECMO outcomes persist in the United States. Further work should aim to understand and mitigate the underlying reasons for such findings.  相似文献   
4.
PurposeTo compare the characteristics of polidocanol (POL) and ethanolamine oleate (EO) sclerosing foams produced by a Shirasu porous glass membrane (SPGM) device with those made using a 3-way stopcock (3WSC).Materials and MethodsFoam half-life times were measured in an ex-vivo benchtop study. Computed tomography (CT) images of each foam were obtained over the time course, and a CT texture analysis was conducted. The bubble size in each foam was measured by an optical microscope.ResultsMedian foam half-life times were longer in the SPGM group than in the 3WSC group (POL: 198 vs 166 s, P = .02; EO: 640 vs 391 s, P < .01). In the CT texture analysis, median standard deviation (SD) and entropy (randomness) were lower, and median energy (uniformity) and gray-level cooccurrence matrix (GLCM) homogeneity were higher in the SPGM group than in the 3WSC group (POL SD: at 30 s and 50–300 s; POL entropy: at 0–60 s; EO SD: at 0–600 s; EO entropy: at 0–460 s; POL energy: at 0–40 s; POL GLCM homogeneity: at 0–250 s; EO energy: at 0–360 s; EO GLCM homogeneity: at 0–480 s; all P < .05). Median bubble diameters in the SPGM group and in the 3WSC group were 69 and 83 μm (P < .01), respectively, in the POL foam; and 36 and 36 μm (P = .45), respectively, in the EO foam.ConclusionsPOL and EO foams had greater uniformity and longer foam half-life time when prepared with an SPGM device than with a 3WSC.  相似文献   
5.
6.
7.
8.
9.
Perinatal palliative care has grown out of both an historical necessity in attending to babies in the NICU that face difficult odds of survival, the increasing technology that may avail life-extending, yet technology-dependent, care, and the growth of fetal diagnostic and treatment centers. This review looks ta the history and ethical rationale for making available services from Pediatric and Perinatal Palliative Care to families in the prenatal and postnatal periods caring for a loved one with life-limiting circumstances.  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