首页 | 官方网站   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   17946篇
  免费   1170篇
  国内免费   129篇
医药卫生   19245篇
  2023年   218篇
  2022年   208篇
  2021年   962篇
  2020年   705篇
  2019年   849篇
  2018年   1008篇
  2017年   713篇
  2016年   772篇
  2015年   781篇
  2014年   1046篇
  2013年   1205篇
  2012年   1642篇
  2011年   1690篇
  2010年   998篇
  2009年   762篇
  2008年   1108篇
  2007年   984篇
  2006年   828篇
  2005年   704篇
  2004年   554篇
  2003年   454篇
  2002年   389篇
  2001年   48篇
  2000年   58篇
  1999年   58篇
  1998年   50篇
  1997年   44篇
  1996年   36篇
  1995年   35篇
  1994年   18篇
  1993年   33篇
  1992年   23篇
  1991年   17篇
  1990年   19篇
  1989年   20篇
  1988年   17篇
  1987年   10篇
  1986年   13篇
  1985年   12篇
  1984年   19篇
  1983年   17篇
  1982年   16篇
  1981年   11篇
  1980年   12篇
  1979年   13篇
  1978年   10篇
  1977年   6篇
  1976年   10篇
  1974年   8篇
  1973年   7篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
3.
Objective: To determine whether packed red blood cell (PRBC) transfusion affects post-prandial superior mesenteric artery blood flow velocities (SMA BFVs) in very-low birth weight (VLBW) neonates and if so, at what time point after transfusion restoration of previous SMA BFV patterns occurs.

Design/Methods: VLBW pre-term neonates, older than 14 days and tolerating bolus enteral feedings administered every 3?h were enrolled in this prospective observational study. Pulsed Doppler ultrasound was used to measure pre- and post-prandial (at 45?min) time-averaged mean, peak and end diastolic velocities (TAMV, PSV, EDV) immediately before and after 15?ml/kg of PRBC transfusion was given over 3?h; patent ductus arteriosus (PDA) status was also evaluated. Subsequent pre- and post-prandial SMA BFVs were recorded 24 and 48?h after the transfusion.

Results: Pre- and post-prandial measurements were obtained for 21 out of 25 enrolled infants. Post-prandial SMA BFVs were attenuated during the feedings immediately after transfusion; at 24 and 48?h after transfusion, changes in post-prandial SMA BFVs were similar to those measured prior to transfusion; the presence of the PDA did not affect results.

Conclusions: PRBC transfusion blunted SMA BFV responses to feedings immediately after the transfusion with normalization observed 24?h post-transfusion.  相似文献   
4.
ABSTRACT

Purpose

To investigate the expression of IL-11 and its receptor IL-11Rα and to quantify density of CD163+ M2 macrophages in proliferative diabetic retinopathy (PDR).  相似文献   
5.
Nonalcoholic fatty liver disease (NAFLD) is a major cause of liver‐related morbidity; its prevalence is elevating due to the rising epidemic of obesity. Several clinical trials have examined the effects of curcumin supplementation on anthropometric variables in NAFLD patients with inconclusive results. This dose–response meta‐analysis aimed to evaluate the impact of curcumin supplementation on body mass index (BMI), body weight, and waist circumference (WC) in patients with NAFLD. A systematic review of the literature was conducted using PubMed/Medline, ISI Web of Science, Scopus, Cochrane Library, EMBASE, Google Scholar, Sid.ir, and Magiran.com to identify eligible studies up to March 2019. A meta‐analysis of eligible studies was performed using the random‐effects model to estimate the pooled effect size. Eight randomized controlled trials with 520 participants (curcumin group = 265 and placebo group = 255) were included. Supplementation dose and duration ranged from 70 to 3,000 mg/day and 8 to 12 weeks, respectively. Curcumin supplementation significantly reduced BMI (weighted mean difference [WMD] = ?0.34 kg/m2, 95% CI [?0.64, ?0.04], p < .05) and WC (WMD = ?2.12 cm, 95% CI [?3.26, ?0.98], p < .001). However, no significant effects of curcumin supplementation on body weight were found. These results suggest that curcumin supplementation might have a positive effect on visceral fat and abdominal obesity that have been associated with NAFLD.  相似文献   
6.
7.
8.
9.
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-23

京公网安备 11010802026262号