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   491篇
  免费   33篇
  国内免费   32篇
耳鼻咽喉   3篇
儿科学   29篇
妇产科学   10篇
基础医学   46篇
口腔科学   42篇
临床医学   61篇
内科学   110篇
皮肤病学   3篇
神经病学   24篇
特种医学   62篇
外科学   26篇
综合类   20篇
预防医学   30篇
眼科学   4篇
药学   63篇
中国医学   3篇
肿瘤学   20篇
  2023年   4篇
  2022年   7篇
  2021年   6篇
  2020年   5篇
  2019年   10篇
  2018年   12篇
  2017年   8篇
  2016年   7篇
  2015年   12篇
  2014年   21篇
  2013年   24篇
  2012年   28篇
  2011年   33篇
  2010年   23篇
  2009年   26篇
  2008年   34篇
  2007年   31篇
  2006年   22篇
  2005年   14篇
  2004年   10篇
  2003年   8篇
  2002年   5篇
  2001年   5篇
  2000年   2篇
  1999年   13篇
  1998年   12篇
  1997年   17篇
  1996年   15篇
  1995年   13篇
  1994年   19篇
  1993年   14篇
  1992年   9篇
  1991年   8篇
  1990年   4篇
  1989年   11篇
  1988年   6篇
  1987年   10篇
  1986年   6篇
  1985年   6篇
  1984年   3篇
  1983年   3篇
  1982年   3篇
  1981年   10篇
  1980年   2篇
  1979年   2篇
  1977年   3篇
  1976年   4篇
  1975年   5篇
  1971年   1篇
排序方式: 共有556条查询结果,搜索用时 15 毫秒
31.
32.
33.
34.
35.
36.
We describe a middle-aged Chinese systemic lupus erythematosus (SLE) patient developing steroid refractory and transfusion dependent red cell aplasia. Oral danazol 200 mg twice per day was started together with low-dose prednisolone therapy. There was no further recurrence of anemia 1 month after this combined therapy.  相似文献   
37.
Forty patients that received prosthetic appliances as part of dental treatment were interviewed about satisfaction with the apparatus. The opinions of the guardians were also considered. The majority of children had complained about missing teeth, but even a greater percentage expressed satisfaction during wear of the prosthetic appliance. Among the guardians, only one of them expressed dissatisfaction with the appliance design. Rehabilitation plan should be discussed with children and guardians considering their perceptions and adequate indications for each case.  相似文献   
38.
The purpose of this report was to describe the radiographic findings of 6 uncommon situations of supernumerary teeth in a Brazilian pediatric dentistry and orthodontic clinic. Six cases of supernumerary teeth were diagnosed in association with other dental anomalies such as number, position, and form. The supernumeraries were asymptomatic and were detected through routine radiographic examination. The importance of routine radiographic examination is emphasized for the correct diagnosis of supernumerary teeth, and avoidance of associated complications.  相似文献   
39.
Although cardiac hypertrophy in hypertension has been well recognized, the molecular mechanisms for the development of hypertrophy are still largely unknown. In this study, the protein expression profiles of left ventricular myocardia in spontaneously hypertensive rats (SHR) and Wistar-Kyoto (WKY) rats at different ages were analyzed using 2-DE in combination with MALDI-TOF/TOF MS/MS. The results showed that 20 proteins were modulated in the hypertrophic myocardium. Out of these modulated proteins, 13 proteins presented significant changes in SHR at an early stage prior to the development of sustained hypertension, while the changes of the other 7 protein expres- sions occurred only at a late stage in SHR when the blood pressure was significantly elevated, and were largely reversible by treatment with rennin-angiotensin-aldosterone system inhibitors losartan or enalapril. These data demonstrate that the changes in energy metabolism in the hypertrophied heart favor an increase in glycolysis and a decrease in oxidation of fatty acid and glucose, which occur at an early stage in SHR without hypertension. Our results also provide evidence to support the hypothesis that oxidative stress plays an important role in the development of hypertensive cardiac hypertrophy.  相似文献   
40.

Background and purpose:

5-Hydroxytryptamine (5-HT) is a key regulator of the gastrointestinal system and we have shown that submucosal neuronal 5-HT3 receptors exerted a novel inhibitory effect on colonic ion transport. The aim of the present study was to investigate the precise mechanism(s) underlying this inhibitory effect.

Experimental approach:

Mucosa/submucosa or mucosa-only preparations from rat distal colon were mounted in Ussing chambers for measurement of short-circuit current (Isc) as an indicator of ion secretion. Somatostatin release was determined with radioimmunoassay. Intracellular cAMP content was measured with enzyme-linked immunoadsorbent assay (elisa). Immunohistochemical techniques were used to study the expression of 5-HT3 receptors, somatostatin and somatostatin receptors in colonic tissue.

Key results:

In rat distal colonic mucosa/submucosa preparations, pretreatment with 5-HT3 receptor antagonists enhanced 5-HT-induced increases in Isc. However, in mucosa-only preparations without retained neural elements, pretreatment with 5-HT3 receptor antagonists inhibited 5-HT-induced ΔIsc. Pretreatment with a somatostatin-2 (sst2) receptor antagonist in mucosa/submucosa preparations augmented 5-HT-induced ΔIsc. Combination of sst2 and 5-HT3 receptor antagonists did not cause further enhancement of 5-HT-induced ΔIsc. Moreover, both sst2 and 5-HT3 receptor antagonists enhanced 5-HT-induced increase in intracellular cAMP concentration in the mucosa/submucosa preparations. 5-HT released somatostatin from rat colonic mucosa/submucosa preparations, an effect prevented by pretreatment with 5-HT3 receptor antagonists. Immunohistochemical staining demonstrated the presence of 5-HT3 receptors on submucosal somatostatin neurons and of sst2 receptors on colonic mucosa.

Conclusion and implications:

Activation of neuronal 5-HT3 receptors in the submucosal plexus of rat colon suppressed 5-HT-induced ion secretion by releasing somatostatin from submucosal neurons.  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