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   238761篇
  免费   15317篇
  国内免费   999篇
耳鼻咽喉   2558篇
儿科学   6164篇
妇产科学   4475篇
基础医学   29947篇
口腔科学   4432篇
临床医学   24472篇
内科学   50210篇
皮肤病学   3260篇
神经病学   23926篇
特种医学   10221篇
外国民族医学   13篇
外科学   37552篇
综合类   2613篇
现状与发展   1篇
一般理论   178篇
预防医学   16868篇
眼科学   5617篇
药学   15665篇
  1篇
中国医学   323篇
肿瘤学   16581篇
  2023年   1352篇
  2022年   2209篇
  2021年   5381篇
  2020年   3069篇
  2019年   5102篇
  2018年   6117篇
  2017年   4480篇
  2016年   4888篇
  2015年   5791篇
  2014年   8408篇
  2013年   11361篇
  2012年   17437篇
  2011年   18192篇
  2010年   10141篇
  2009年   9374篇
  2008年   16014篇
  2007年   16818篇
  2006年   16358篇
  2005年   16197篇
  2004年   15224篇
  2003年   13917篇
  2002年   13319篇
  2001年   2042篇
  2000年   1567篇
  1999年   2123篇
  1998年   2830篇
  1997年   2265篇
  1996年   1950篇
  1995年   1804篇
  1994年   1552篇
  1993年   1527篇
  1992年   1078篇
  1991年   1028篇
  1990年   869篇
  1989年   845篇
  1988年   763篇
  1987年   696篇
  1986年   718篇
  1985年   753篇
  1984年   954篇
  1983年   840篇
  1982年   1085篇
  1981年   998篇
  1980年   865篇
  1979年   519篇
  1978年   548篇
  1977年   471篇
  1976年   466篇
  1975年   355篇
  1974年   352篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
101.
102.
103.
Geste antagonistes, or sensory tricks, are well described in focal dystonia affecting the neck, hand, and face. Improvement in dystonic movements is typically maintained while the trick is performed, but disappears when the geste ends. We investigated the phenomenological features of geste antagoniste maneuvers in 19 patients with idiopathic lower cranial dystonia who were prospectively evaluated over a period of 6 years. Of the 19, 10 were men, mean age of onset was 49.8 years, and the most commonly involved lower cranial area was the jaw (10 patients). In most patients, dystonia was task-specific. Taking advantage of the improvement with a sensory geste, we manufactured oral appliances that mimicked the geste in 8 patients, and 3 continue to use it.  相似文献   
104.
105.
106.
107.
AMPA receptor potentiators enhance AMPA receptor-mediated glutamatergic neurotransmission and may have therapeutic potential as cognitive enhancers or antidepressants. The anatomical basis for the action of AMPA receptor potentiators is unknown. The aim of this study was to determine the effects of the biarylpropylsulfonamide AMPA receptor potentiator, LY404187 (0.05 to 5 mg/kg subcutaneously), upon cerebral glucose utilization and c-fos expression using 14C-2-deoxglucose autoradiography and c-fos immunocytochemistry. LY404187 (0.5 mg/kg) produced significant elevations in glucose utilization in 28 of the 52 anatomical regions analyzed, which included rostral neocortical areas and the hippocampus, as well the dorsal raphe nucleus, lateral habenula, and locus coeruleus. No significant decreases in glucose utilization were observed in any region after LY404187 administration. The increases in glucose utilization with LY404187 (0.5 mg/kg) were blocked by pretreatment with the AMPA receptor antagonist LY293558 (25 mg/kg), indicating that LY404187 acts through AMPA receptor-mediated mechanisms. LY404187 (0.5 mg/kg) also produced increases in c-fos immunoreactivity in the cortex, locus coeruleus, and the dorsal raphe nucleus. These studies demonstrate neuronal activation in key brain areas that are associated with memory processes and thus provide an anatomical basis for the cognitive enhancing effects of AMPA receptor potentiators.  相似文献   
108.
The goal of the present study was to test the impact of administration time of the angiotensin II type 1-receptor blocker candesartan on cerebral blood flow (CBF), infarct size, and neuroscore in transient cerebral ischemia. Therefore, 1-hour middle cerebral artery occlusion (MCAO) was followed by reperfusion. Rats received 0.5-mg/kg candesartan intravenously 2 hours before MCAO (pretreatment), 24 hours after MCAO, every 24 hours after MCAO, or 2 hours before and every 24 hours after MCAO. Infarct size (mm3) and a neuroscore at day 7 were compared with controls. CBF was quantified by radiolabeled microspheres and laser-Doppler flowmetry. Compared with controls (95 +/- 8), infarct size in candesartan-treated groups was smaller (59 +/- 5, 68 +/- 10, 28 +/- 3, and 15 +/- 3, respectively; P<0.05). Although there was no difference in neuroscore between pretreatment and controls (1.55 +/- 0.18, 1.80 +/- 0.13), other treatment regimens resulted in improved neuroscores (1.33 +/- 0.16, 1.11 +/- 0.11, 0.73 +/- 0.15; P<0.05). CBF in pretreated animals at 0.5 hours after MCAO was significantly higher than in controls (0.58 +/- 0.09 mL x g(-1) x min(-1) and 44% +/- 7% of baseline compared with 0.49 +/- 0.06 mL x g(-1) x min(-1) and 37% +/- 6%, microspheres and laser-Doppler flowmetry; P<0.05). Thus, candesartan reduces infarct size even if administered only during reperfusion. Apart from pretreatment, other treatment regimens result in significantly improved neuroscores. In the acute phase of cerebral ischemia, candesartan increases CBF.  相似文献   
109.
110.
This study retrospectively evaluated the outcome for patients undergoing herniorraphy for chronic groin pain due to posterior inguinal wall deficiency, and correlated the outcome with preoperative investigation findings. There were 47 patients (with a total of 52 herniorraphies) who were contacted by phone between six and 50 months post surgery. Subjects had a diagnosis of posterior inguinal wall deficiency made on history and clinical examination. Thirty seven patients had an ultrasound scan prior to the surgery (three bilateral) with a total of 40 symptomatic groins scanned. There were 26 abnormal scans (22 posterior inguinal wall deficiency and four hernias) and 14 normal scans. Twenty nine patients had a technetium-99m bone scan with 22 having increased uptake at the symptomatic pubic tubercle, while 13 had increased uptake at other sites in the groin. Seventy seven percent of patients had a full return to sport after surgery and the average time to return to sport was four months. There was no significant difference in outcome between subjects who had an abnormal ultrasound scan on the symptomatic side and those who had a normal scan. There was a significant difference in outcome between patients who had a bone scan with increased uptake at the symptomatic pubic tubercle and those who did not (p < 0.04). Our study supports previous research that good results can be obtained with surgery when posterior inguinal wall deficiency is the sole diagnosis. Ultrasound scan does not appear to aid in predicting surgical outcome, while the role of isotope bone scanning requires further study.  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