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   68296篇
  免费   3968篇
  国内免费   149篇
耳鼻咽喉   875篇
儿科学   1572篇
妇产科学   1370篇
基础医学   9058篇
口腔科学   2624篇
临床医学   5243篇
内科学   17090篇
皮肤病学   1679篇
神经病学   6007篇
特种医学   1796篇
外科学   9247篇
综合类   298篇
一般理论   26篇
预防医学   5840篇
眼科学   1261篇
药学   4478篇
中国医学   250篇
肿瘤学   3699篇
  2023年   453篇
  2022年   208篇
  2021年   1114篇
  2020年   656篇
  2019年   1182篇
  2018年   2090篇
  2017年   1250篇
  2016年   1333篇
  2015年   2043篇
  2014年   2080篇
  2013年   3046篇
  2012年   5919篇
  2011年   5781篇
  2010年   2665篇
  2009年   1983篇
  2008年   4916篇
  2007年   5084篇
  2006年   5278篇
  2005年   4977篇
  2004年   4482篇
  2003年   4042篇
  2002年   3903篇
  2001年   1586篇
  2000年   2096篇
  1999年   1016篇
  1998年   263篇
  1997年   217篇
  1996年   206篇
  1995年   184篇
  1994年   160篇
  1993年   159篇
  1992年   140篇
  1991年   128篇
  1990年   89篇
  1989年   123篇
  1988年   102篇
  1987年   90篇
  1986年   104篇
  1985年   106篇
  1984年   104篇
  1983年   88篇
  1982年   97篇
  1981年   91篇
  1980年   94篇
  1979年   53篇
  1978年   51篇
  1977年   55篇
  1976年   46篇
  1975年   44篇
  1974年   38篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.

The exercise pressor reflex is a feedback mechanism engaged upon stimulation of mechano- and metabosensitive skeletal muscle afferents. Activation of these afferents elicits a reflex increase in heart rate, blood pressure, and ventilation in an intensity-dependent manner. Consequently, the exercise pressor reflex has been postulated to be one of the principal mediators of the cardiorespiratory responses to exercise. In this updated review, we will discuss classical and recent advancements in our understating of the exercise pressor reflex function in both human and animal models. Particular attention will be paid to the afferent mechanisms and pathways involved during its activation, its effects on different target organs, its potential role in the abnormal cardiovascular response to exercise in diseased states, and the impact of age and biological sex on these responses. Finally, we will highlight some unanswered questions in the literature that may inspire future investigations in the field.

  相似文献   
2.
In the current immunosuppressive therapy era, vessel thrombosis is the most common cause of early graft loss after renal transplantation. The prevalence of IgA anti–β2-glycoprotein I antibodies (IgA-aB2GPI-ab) in patients on dialysis is elevated (>30%), and these antibodies correlate with mortality and cardiovascular morbidity. To evaluate the effect of IgA-aB2GPI-ab in patients with transplants, we followed all patients transplanted from 2000 to 2002 in the Hospital 12 de Octubre prospectively for 10 years. Presence of IgA-aB2GPI-ab in pretransplant serum was examined retrospectively. Of 269 patients, 89 patients were positive for IgA-aB2GPI-ab (33%; group 1), and the remaining patients were negative (67%; group 2). Graft loss at 6 months post-transplant was significantly higher in group 1 (10 of 89 versus 3 of 180 patients in group 2; P=0.002). The most frequent cause of graft loss was thrombosis of the vessels, which was observed only in group 1 (8 of 10 versus 0 of 3 patients in group 2; P=0.04). Multivariate analysis showed that the presence of IgA-aB2GPI-ab was an independent risk factor for early graft loss (P=0.04) and delayed graft function (P=0.04). There were no significant differences regarding patient survival between the two groups. Graft survival was similar in both groups after 6 months. In conclusion, patients with pretransplant IgA-aB2GPI-ab have a high risk of early graft loss caused by thrombosis and a high risk of delayed graft function. Therefore, pretransplant IgA-aB2GPI-ab may have a detrimental effect on early clinical outcomes after renal transplantation.  相似文献   
3.
Lasers in Medical Science - Studies reported the harmful effects of 2,4-D on body tissues, provoking changes in the anatomy and physiology of the kidneys, liver, and testicles. Thus, the objective...  相似文献   
4.
5.
6.
7.
8.
9.
10.

Background

Early dumping is a poorly defined and incompletely understood complication after Roux-en-Y gastric (RYGB).

Objective

We performed a mixed-meal tolerance test in patients after RYGB to address the prevalence of early dumping and to gain further insight into its pathophysiology.

Setting

The study was conducted in a regional hospital in the northern part of the Netherlands.

Methods

From a random sample of patients who underwent primary RYGB between 2008 and 2011, 46 patients completed the mixed-meal tolerance test. The dumping severity score for early dumping was assessed every 30 minutes. A sum score at 30 or 60 minutes of ≥5 and an incremental score of ≥3 points were defined as indicating a high suspicion of early dumping. Blood samples were collected at baseline, every 10 minutes during the first half hour, and at 60 minutes after the start.

Results

The prevalence of a high suspicion of early dumping was 26%. No differences were seen for absolute hematocrit value, inactive glucagon-like peptide-1, and vasoactive intestinal peptide between patients with or without early dumping. Patients at high suspicion of early dumping had higher levels of active glucagon-like peptide-1 and peptide YY.

Conclusion

The prevalence of complaints at high suspicion of early dumping in a random population of patients after RYGB is 26% in response to a mixed-meal tolerance test. Postprandial increases in both glucagon-like peptide-1 and peptide YY are associated with symptoms of early dumping, suggesting gut L-cell overactivity in this syndrome.  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