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   20747篇
  免费   1122篇
  国内免费   91篇
耳鼻咽喉   271篇
儿科学   524篇
妇产科学   380篇
基础医学   2724篇
口腔科学   2080篇
临床医学   1540篇
内科学   4174篇
皮肤病学   466篇
神经病学   1575篇
特种医学   377篇
外国民族医学   2篇
外科学   2149篇
综合类   146篇
一般理论   3篇
预防医学   3022篇
眼科学   236篇
药学   1375篇
中国医学   230篇
肿瘤学   686篇
  2023年   189篇
  2022年   398篇
  2021年   801篇
  2020年   555篇
  2019年   670篇
  2018年   786篇
  2017年   573篇
  2016年   612篇
  2015年   701篇
  2014年   974篇
  2013年   1113篇
  2012年   1680篇
  2011年   1900篇
  2010年   898篇
  2009年   644篇
  2008年   1194篇
  2007年   1264篇
  2006年   975篇
  2005年   886篇
  2004年   784篇
  2003年   693篇
  2002年   587篇
  2001年   356篇
  2000年   351篇
  1999年   282篇
  1998年   105篇
  1997年   65篇
  1996年   44篇
  1995年   54篇
  1994年   60篇
  1993年   50篇
  1992年   139篇
  1991年   113篇
  1990年   133篇
  1989年   115篇
  1988年   108篇
  1987年   71篇
  1986年   81篇
  1985年   69篇
  1984年   44篇
  1983年   47篇
  1979年   63篇
  1978年   38篇
  1973年   43篇
  1971年   36篇
  1970年   58篇
  1969年   69篇
  1968年   49篇
  1967年   53篇
  1966年   47篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
5.
Acute lung injury (ALI) caused by systemic inflammatory response remains a leading cause of morbidity and mortality in critically ill patients. Management of patients with sepsis is largely limited to supportive therapies, reflecting an incomplete understanding of the underlying pathophysiology. Furthermore, there have been limited advances in the treatments for ALI. In this study, lung function and a histological analysis were performed to evaluate the impact of transient receptor potential vanilloid‐1 receptor (TRPV1) antagonist (capsazepine; CPZ) on the lipopolysaccharide (LPS)‐induced lung injury in mice. For this, adult mice pre‐treated with CPZ or vehicle received intraperitoneal injections of LPS or saline and 24 hr after, the mice were anaesthetized, and lung mechanics was evaluated. The LPS‐challenged mice exhibited substantial mechanical impairment, characterized by increases in respiratory system resistance, respiratory system elastance, tissue damping and tissue elastance. The pre‐treatment with CPZ prevented the increase in respiratory system resistance and decreased the increase in tissue damping during endotoxemia. In addition, mice pre‐treated with CPZ had an attenuated lung injury evidenced by reduction on collapsed area of the lung parenchyma induced by LPS. This suggests that the TRPV1 antagonist capsazepine has a protective effect on lung mechanics in ALI during endotoxemia and that it may be a target for enhanced therapeutic efficacy in ALI.  相似文献   
6.
7.
8.
Objective: Longitudinal data on cardiometabolic effects of egg intake during adolescence are lacking. The current analyses aim to evaluate the impact of usual adolescent egg consumption on lipid levels, fasting glucose, and insulin resistance during late adolescence (age 17–20?years).

Methods: Data from 1392 girls, aged 9 to 10 at baseline and followed for 10?years, in the National Heart, Lung, and Blood Institute’s National Growth and Health Study were used to examine the association between usual egg intake alone and in combination with other healthy lifestyle factors and late adolescent lipid levels, fasting glucose, and insulin resistance, measured as homeostasis model assessment of insulin resistance (HOMA-IR). Diet was assessed using 3-day food records during eight examination cycles. Girls were classified according to usual weekly egg intake, ages 9–17?years:?<1 egg/wk (n?=?361), 1 to <3 eggs/wk (n?=?703), and ≥3 eggs/wk (n?=?328). Analysis of covariance modeling was used to control for confounding by other behavioral and biological risk factors.

Results: Girls with low, moderate, and high egg intakes had adjusted low-density lipoprotein cholesterol levels of 99.7, 98.8, and 95.5 mg/dL, respectively (p?=?0.0778). In combination with higher intakes of fiber, dairy, or fruits and vegetables, these beneficial effects were stronger and statistically significant. There was no evidence that ≥3 eggs/wk had an adverse effect on lipids, glucose, or HOMA-IR. More active girls who consumed ≥3 eggs/wk had the lowest levels of insulin resistance.

Conclusion: These results suggest that eggs may be included as part of a healthy adolescent diet without adverse effects on glucose, lipid levels, or insulin resistance.  相似文献   

9.
10.
Melatonin, the main hormone produced by the pineal gland, is secreted in a circadian manner (24‐hr period), and its oscillation influences several circadian biological rhythms, such as the regulation of clock genes expression (chronobiotic effect) and the modulation of several endocrine functions in peripheral tissues. Assuming that the circadian synchronization of clock genes can play a role in the regulation of energy metabolism and it is influenced by melatonin, our study was designed to assess possible alterations as a consequence of melatonin absence on the circadian expression of clock genes in the epididymal adipose tissue of male Wistar rats and the possible metabolic repercussions to this tissue. Our data show that pinealectomy indeed has impacts on molecular events: it abolishes the daily pattern of the expression of Clock, Per2, and Cry1 clock genes and Pparγ expression, significantly increases the amplitude of daily expression of Rev‐erbα, and affects the pattern of and impairs adipokine production, leading to a decrease in leptin levels. However, regarding some metabolic aspects of adipocyte functions, such as its ability to synthesize triacylglycerols from glucose along 24 hr, was not compromised by pinealectomy, although the daily profile of the lipogenic enzymes expression (ATP‐citrate lyase, malic enzyme, fatty acid synthase, and glucose‐6‐phosphate dehydrogenase) was abolished in pinealectomized animals.  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