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   4590篇
  免费   241篇
  国内免费   29篇
耳鼻咽喉   52篇
儿科学   113篇
妇产科学   39篇
基础医学   382篇
口腔科学   67篇
临床医学   242篇
内科学   1297篇
皮肤病学   169篇
神经病学   244篇
特种医学   178篇
外科学   887篇
综合类   16篇
预防医学   102篇
眼科学   120篇
药学   279篇
中国医学   3篇
肿瘤学   670篇
  2024年   8篇
  2023年   58篇
  2022年   41篇
  2021年   172篇
  2020年   99篇
  2019年   116篇
  2018年   135篇
  2017年   129篇
  2016年   148篇
  2015年   151篇
  2014年   183篇
  2013年   223篇
  2012年   338篇
  2011年   365篇
  2010年   197篇
  2009年   141篇
  2008年   236篇
  2007年   276篇
  2006年   267篇
  2005年   267篇
  2004年   215篇
  2003年   225篇
  2002年   214篇
  2001年   83篇
  2000年   59篇
  1999年   55篇
  1998年   40篇
  1997年   29篇
  1996年   26篇
  1995年   22篇
  1994年   25篇
  1993年   17篇
  1992年   34篇
  1991年   26篇
  1990年   26篇
  1989年   24篇
  1988年   19篇
  1987年   18篇
  1986年   18篇
  1985年   14篇
  1984年   11篇
  1983年   19篇
  1982年   8篇
  1980年   7篇
  1979年   7篇
  1977年   5篇
  1974年   6篇
  1973年   8篇
  1972年   12篇
  1971年   11篇
排序方式: 共有4860条查询结果,搜索用时 15 毫秒
51.
52.
53.
54.
55.
56.
57.
58.
Prostaglandins and thromboxanes are important modulators of airway physiology. The synthesis of these mediators depends on two isoforms of cyclooxygenase (COX), constitutive COX-1 and inducible COX-2. COX-2 expression has been observed in various inflammatory diseases, but not all aspects of the expression and the role of COX-2 in conditions of allergic inflammation such as asthma are clear. In the present study, we examined the 72-h kinetics of the expression of COX-isoform mRNA in ovalbumin-sensitized and -challenged guinea-pig lungs. The sensitized animals showed a robust and transient induction of COX-2 mRNA expression within 1 h after ovalbumin challenge, whereas their COX-1 mRNA levels remained unchanged. Upregulation of the level and activity of COX-2 protein followed the induction of COX-2 mRNA. Lung slices harvested from ovalbumin-challenged animals released more prostaglandin D(2) and prostaglandin E(2) spontaneously or in response to A23187 (10 microM) ex vivo than did those from unchallenged animals. This response was significantly blocked by the COX-2 selective inhibitors, NS-398 and JTE-522. In vivo administration of NS-398 significantly inhibited the accumulation of eosinophils and neutrophils in the lungs. In conclusion, de novo COX-2 expression during allergic inflammation modifies prostanoid synthesis in the lung and airway pathophysiology.  相似文献   
59.
BackgroundEosinophilic chronic rhinosinusitis (ECRS) is often complicated by asthma and can be difficult to diagnose. This study aimed to clarify the usefulness of the self-administered odor questionnaire (SAOQ) and visual analog scale (VAS) to identify olfactory disorders in patients with asthma.MethodsThis retrospective study was conducted on patients with asthma who were referred to the Otolaryngology clinic between May and September 2018. The treatment step of asthma, asthma control test (ACT), pulmonary function test, peripheral blood eosinophils, and fractional exhaled nitric oxide (FeNO) were analyzed. ECRS was diagnosed based on the Japanese Epidemiological Survey of Refractory Eosinophilic Chronic Rhinosinusitis Study score. Olfactory dysfunction was evaluated using the SAOQ and VAS for olfactory disorders.ResultsThe study included 56 patients (18 males and 38 females), who were divided into two groups; those with ECRS (n = 18) and those without ECRS (n = 38). Age, sex, treatment step, ACT score, and pulmonary function were not significantly different between the groups. The ECRS group had a significantly higher FeNO value (89.1 ppb vs. 39.1 ppb) and a significantly lower SAOQ score (40.1% vs. 96.1%). The area under the receiver operating characteristic curve for the efficacy of ECRS diagnosis was 0.88, 0.889, 0.799, and 0.757 for SAOQ, VAS, blood eosinophil count, and FeNO, respectively.ConclusionThe SAOQ and VAS scores were useful tools that presented similar results to the blood eosinophil count and FeNO, and may help to improve the diagnosis of ECRS in patients with asthma.  相似文献   
60.
The systemic hemodynamic and coronary dilative responses to sublingual nitroglycerin were studied in patients receiving transdermal nitroglycerin. A total of 48 patients with coronary artery disease were divided into 4 groups: 12 patients receiving 1 tablet of sublingual nitroglycerin without transdermal nitroglycerin (Group 1), 12 patients receiving 1 tablet of sublingual nitroglycerin with 12-hour-daily intermittent therapy of transdermal nitroglycerin (Group 2), 12 patients receiving 1 tablet of sublingual nitroglycerin with continuous therapy of transdermal nitroglycerin (Group 3), and 12 patients receiving 2 tablets of sublingual nitroglycerin with continuous therapy of transdermal nitroglycerin (Group 4). Before and during administration of sublingual nitroglycerin, aortic pressure, left ventricular pressure, and coronary artery diameter were examined at diagnostic cardiac catheterization in all patients. During sublingual nitroglycerin, the decreases of aortic systolic pressure and left ventricular end-diastolic pressure were greater in Group 1, 2, and 4 than in Group 3. Dilation of coronary arteries by sublingual nitroglyerin tended to be greater in Group 1, 2, and 4 than in Group 3. Thus, the effects of sublingual nitroglycerin for the relief of ischemia might be more prominent in patients with intermittent therapy of transdermal nitroglycerin than in those with continuous therapy. The increased dose of sublingual nitroglycerin for the relief of ischemia might be more effective in patients with continuous therapy of transdermal nitroglycerin.  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