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   28637篇
  免费   1959篇
  国内免费   113篇
耳鼻咽喉   294篇
儿科学   801篇
妇产科学   597篇
基础医学   4351篇
口腔科学   2576篇
临床医学   2280篇
内科学   5666篇
皮肤病学   614篇
神经病学   2227篇
特种医学   612篇
外国民族医学   1篇
外科学   3256篇
综合类   355篇
一般理论   8篇
预防医学   3278篇
眼科学   358篇
药学   2070篇
中国医学   284篇
肿瘤学   1081篇
  2023年   262篇
  2022年   568篇
  2021年   1110篇
  2020年   764篇
  2019年   958篇
  2018年   1113篇
  2017年   823篇
  2016年   830篇
  2015年   989篇
  2014年   1272篇
  2013年   1505篇
  2012年   2298篇
  2011年   2522篇
  2010年   1321篇
  2009年   1003篇
  2008年   1660篇
  2007年   1552篇
  2006年   1410篇
  2005年   1160篇
  2004年   1020篇
  2003年   931篇
  2002年   812篇
  2001年   553篇
  2000年   607篇
  1999年   485篇
  1998年   180篇
  1997年   119篇
  1996年   120篇
  1995年   110篇
  1994年   95篇
  1993年   77篇
  1992年   220篇
  1991年   206篇
  1990年   199篇
  1989年   190篇
  1988年   176篇
  1987年   132篇
  1986年   120篇
  1985年   121篇
  1984年   101篇
  1983年   80篇
  1979年   84篇
  1978年   75篇
  1977年   45篇
  1975年   54篇
  1974年   62篇
  1973年   63篇
  1970年   60篇
  1969年   47篇
  1967年   54篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
International Journal of Clinical Oncology - Immune-checkpoint inhibitors (ICIs) are standard treatments for metastatic non-small cell lung cancer (NSCLC). Patients with poor performance status...  相似文献   
2.
3.
4.
Neorickettsia helminthoeca (NH), the agent of salmon poisoning disease or canine neorickettiosis (CN), is a bacterial endosymbiont of the nematode Nanophyetus salmincola, and infections are spreading among specific fish‐eating mammalians. This article describes the pathologic and immunohistochemical findings associated with spontaneous NH‐induced infections in dogs from Southern Brazil. The principal pathologic findings were hypertrophy of Peyer patches and lymphadenopathy with lymphocytic proliferation, chronic interstitial pneumonia, and chronic enteritis associated with positive intralesional immunoreactivity to antigens of NH within macrophages and histiocytes. Positive immunoreactivity against canine parvovirus‐2 (CPV‐2) or/and canine distemper virus was not detected in the evaluated intestinal segments or in the samples from the cerebellum and lungs, respectively, from the dogs evaluated. These findings demonstrated that NH was involved in the enteric, pulmonary, and lymphoid lesions herein described, and provide additional information to confirm the occurrence of this bacterial endosymbiont within this geographical location. It is proposed that chronic pneumonia should be considered as a pathologic manifestation of NH‐induced infections. Additionally, our results show that the occurrences of CN seem to be underdiagnosed in Southern Brazil due to the confusion with the incidence of CPV‐2.  相似文献   
5.
6.
7.
8.
9.
10.
Pulmonary hypertension of the newborn (PHN) constitutes a critical condition with severe cardiovascular and neurological consequences. One of its main causes is hypoxia during gestation, and thus, it is a public health concern in populations living above 2500 m. Although some mechanisms are recognized, the pathophysiological facts that lead to PHN are not fully understood, which explains the lack of an effective treatment. Oxidative stress is one of the proposed mechanisms inducing pulmonary vascular dysfunction and PHN. Therefore, we assessed whether melatonin, a potent antioxidant, improves pulmonary vascular function. Twelve newborn sheep were gestated, born, and raised at 3600 meters. At 3 days old, lambs were catheterized and daily cardiovascular measurements were recorded. Lambs were divided into two groups, one received daily vehicle as control and another received daily melatonin (1 mg/kg/d), for 8 days. At 11 days old, lung tissue and small pulmonary arteries (SPA) were collected. Melatonin decreased pulmonary pressure and resistance for the first 3 days of treatment. Further, melatonin significantly improved the vasodilator function of SPA, enhancing the endothelial‐ and muscular‐dependent pathways. This was associated with an enhanced nitric oxide‐dependent and nitric oxide independent vasodilator components and with increased nitric oxide bioavailability in lung tissue. Further, melatonin reduced the pulmonary oxidative stress markers and increased enzymatic and nonenzymatic antioxidant capacity. Finally, these effects were associated with an increase of lumen diameter and a mild decrease in the wall of the pulmonary arteries. These outcomes support the use of melatonin as an adjuvant in the treatment for PHN.  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