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   2161篇
  免费   211篇
耳鼻咽喉   25篇
儿科学   35篇
妇产科学   82篇
基础医学   399篇
口腔科学   36篇
临床医学   352篇
内科学   321篇
皮肤病学   26篇
神经病学   175篇
特种医学   123篇
外科学   211篇
综合类   27篇
一般理论   3篇
预防医学   175篇
眼科学   78篇
药学   232篇
中国医学   1篇
肿瘤学   71篇
  2021年   28篇
  2020年   18篇
  2019年   31篇
  2018年   29篇
  2017年   22篇
  2016年   30篇
  2015年   30篇
  2014年   46篇
  2013年   70篇
  2012年   95篇
  2011年   109篇
  2010年   49篇
  2009年   44篇
  2008年   87篇
  2007年   95篇
  2006年   103篇
  2005年   98篇
  2004年   81篇
  2003年   92篇
  2002年   63篇
  2001年   69篇
  2000年   69篇
  1999年   56篇
  1998年   25篇
  1997年   34篇
  1996年   28篇
  1995年   28篇
  1994年   22篇
  1993年   32篇
  1992年   60篇
  1991年   60篇
  1990年   53篇
  1989年   48篇
  1988年   55篇
  1987年   59篇
  1986年   39篇
  1985年   40篇
  1984年   22篇
  1983年   22篇
  1982年   25篇
  1981年   17篇
  1980年   17篇
  1979年   32篇
  1978年   17篇
  1976年   18篇
  1975年   17篇
  1974年   21篇
  1973年   21篇
  1971年   17篇
  1970年   21篇
排序方式: 共有2372条查询结果,搜索用时 15 毫秒
1.
The jobs of Latino manual laborers place their mental and physical health at risk. This study evaluates the associations among musculoskeletal pain, mental health, and work organization in Latino manual laborers. Farmworkers and nonfarmworkers (n = 189) in North Carolina were interviewed for self-reported musculoskeletal pain, depressive symptoms, stress, work safety climate, and precarious job status. More nonfarmworkers than farmworkers had neck and shoulder pain, but they did not differ in other areas of musculoskeletal pain. Depressive symptoms had a significant association with neck and shoulder pain (p < .05). Precariousness had a significant association with back pain (p < .05). Farmworker participants had H-2A visas and were afforded some protection compared to nonfarmworker manual workers. Research is needed to improve policy that relieves pain and improves mental health for all Latino manual workers.  相似文献   
2.
3.
4.
5.
The characteristics of [3H]-prazosin binding in renal cortical membranes of the rat have been assessed under a variety of buffer conditions. At 37 degrees, in Krebs' phosphate and Tris buffer, [3H]-prazosin bound to two sites, a small population of high affinity sites with properties of alpha1-adrenoceptors and a much larger population of low affinity sites with different characteristics. High affinity [3H]-prazosin binding was insensitive to Na+, K+, Ca2+ and Mg2+ ions, but low affinity [3H]-prazosin binding was markedly increased in Krebs' phosphate or sodium phosphate buffer and further enhanced in membranes pretreated with EGTA. Binding was decreased in the presence of Ca2+, the decrease in binding mainly being due to a decrease in the number of low affinity sites labelled by the ligand. Low affinity [3H]-prazosin binding was increased at 37 degrees and relatively insensitive to alpha-adrenoceptor antagonists which were weak competitors while catecholamines failed to compete for low affinity binding. Scatchard plots of [3H]-prazosin binding performed using (-)-noradrenaline (1 mM) to define non-specific binding defined binding only to alpha 1-adrenoceptors. This provides a means of differentiating high and low affinity [3H]-prazosin binding.  相似文献   
6.
7.
8.
9.
In 6 patients with Parkinson's disease (PD) and 6 age-matched controls, transcranial magnetic stimulation was applied at 56 regions over the motor cortex and premotor cortex of each hemisphere, with the first dorsal interosseous (FDI) muscle of both hands activated at 15% maximum voluntary contraction during stimulation. For each site, motor evoked potential (MEP) landmarks were recovered, including MEP amplitude, MEP onset latency, and silent period duration. Scaled MEP amplitudes were used to construct individual cortical maps of the FDI muscles. The maps revealed an anterior displacement of the muscle representation in PD patients. This anterior shift over motor cortical areas may reflect increased contributions of corticocortical connections between motor cortex and premotor cortical areas, possibly enhanced by the visual feedback aspect of the task. These alterations may reflect adaptations to the impairments in striatocortical circuits in PD.  相似文献   
10.
Cervical exploration was performed in 106 patients with primary hyperparathyroidism and in 19 patients with chronic renal failure. Initial exploration for primary hyperparathyroidism was successful in 97% of the cases. Single adenomas were found in 84, double adenomas in six, and multiple-gland hyperplasia in 12 patients. Two of the four patients in whom cervical exploration failed were ultimately given the diagnosis of benign familial hypocalciuric hypercalcemia. Thirteen adenomas were ectopic. Preoperative thallium-technetium scans and ultrasound correctly localized only 63% of the adenomas. Only 45% of the ectopic adenomas were correctly localized. All four glands should be examined at initial exploration. Because of the occurrence of double adenomas, contralateral exploration is always indicated regardless of whether an enlarged gland and a normal one are found on the first side. All enlarged parathyroids should be removed when dealing with single or multiple adenomas; subtotal parathyroidectomy (3 1/2 glands) should be performed in multiple-gland hyperplasia. Frozen section confirmation of excised parathyroid tissue is essential. If exploration is unsuccessful, ectopic locations such as the retroesophageal areas, thymus, anterior and posterior mediastinum, carotid sheath, and thyroid lobe must be searched carefully. Preoperative localization studies are not as reliable as an experience parathyroid surgeon.  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