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   42366篇
  免费   2638篇
  国内免费   1359篇
耳鼻咽喉   641篇
儿科学   1030篇
妇产科学   1076篇
基础医学   4361篇
口腔科学   709篇
临床医学   4116篇
内科学   6427篇
皮肤病学   1854篇
神经病学   2838篇
特种医学   998篇
外国民族医学   1篇
外科学   1857篇
综合类   5878篇
现状与发展   3篇
预防医学   4532篇
眼科学   495篇
药学   6317篇
  28篇
中国医学   2154篇
肿瘤学   1048篇
  2024年   59篇
  2023年   472篇
  2022年   1005篇
  2021年   1444篇
  2020年   1247篇
  2019年   1129篇
  2018年   1209篇
  2017年   1232篇
  2016年   1229篇
  2015年   1303篇
  2014年   2501篇
  2013年   2915篇
  2012年   2543篇
  2011年   2735篇
  2010年   2240篇
  2009年   2076篇
  2008年   2100篇
  2007年   2187篇
  2006年   1838篇
  2005年   1720篇
  2004年   1417篇
  2003年   1248篇
  2002年   1024篇
  2001年   937篇
  2000年   814篇
  1999年   767篇
  1998年   604篇
  1997年   614篇
  1996年   545篇
  1995年   556篇
  1994年   489篇
  1993年   381篇
  1992年   424篇
  1991年   384篇
  1990年   320篇
  1989年   326篇
  1988年   316篇
  1987年   277篇
  1986年   229篇
  1985年   260篇
  1984年   201篇
  1983年   168篇
  1982年   182篇
  1981年   142篇
  1980年   121篇
  1979年   88篇
  1978年   77篇
  1977年   63篇
  1976年   48篇
  1975年   37篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
101.
Impairment of the auditory-vestibular system has been reported in patients with vertebrobasilar dolichoectasia (VBD), but little is known about the underlying cause of the symptoms. Auditory testing (pure tone audiometry, auditory brain stem response and stapedius reflex) and vestibular tests (assessment of nystagmus, eye tracking tests, caloric test and rotational test) were performed in 23 patients with auditory-vestibular symptoms and/or cranial nerve impairment associated with VBD. Specific evidence of auditory and/or vestibular system impairment was observed in 19 cases (83%). Among patients with abnormal test findings, 47% had evidence suggesting peripheral impairment, 16% evidence suggesting central dysfunction, and 37% evidence suggesting both peripheral and central dysfunction. Although compression of the vestibulocochlear nerve plays an important role in the genesis of the auditory-vestibular dysfunction in patients with VBD, mechanism such as brain stem-cerebellar ischemia and impaired blood supply to the vestibular labyrinth may be just as important.  相似文献   
102.
本文报道46例肝硬化患者口服葡萄糖胰岛素释放试验的结果,并与18名正常人和18名原发性糖尿病患者比较。肝硬化患者糖耐量减低者28例(60.9%),其中29例(43.5%)呈糖尿病型耐量曲线。胰岛素释放高峰值在服糖后2h;释放过多和分泌延迟者32例(69.6%),降低者4例(8.7%)。20例肝源性糖尿病患者的胰岛素释放指数明显高于原发性糖尿患者。笔者认为血浆胰岛素和胰岛素释放指数测定对鉴别这两种类型的糖尿病有很大价值。  相似文献   
103.
Abstract: The small-dose (20 mg) oral iron absorption test (OIAT) was performed in 76 hospitalized elderly patients and 30 healthy adults. Of the elderly patients, 34 were considered as iron deficient (serum ferritin level <20 μg/L) of whom 23 were anaemic and 11 not anaemic, 21 had the anaemia of chronic disorders (ACD) and another 21 were non-anaemic patients with a normal serum ferritin level. There was a significant inverse correlation between the serum ferritin level as a measure of iron store and the maximum increase in serum iron during a 3-h test (Cmax), in the elderly as well as in the healthy adult group. A decision limit of 80 μg/dL for Cmax is a good discriminant between absent (serum ferritin <20 μg/L) and adequate body iron stores. Sixty-eight per cent of the patients with a serum ferritin level <20 μg/L but virtually none of the ACD patients, non-anaemic elderly inpatients with normal serum ferritin levels and healthy adults had a Cmax level >80 μg/L. Although further investigation is needed before the OIAT can be recommended as a valuable test for evaluating iron absorption, predicting mild iron deficiency and differentiating between different categories of anaemia, it seems worthwile that more effort should be done to validate this simple and safe test.  相似文献   
104.
选择南方热区某特种部队战士52人,分两组分别口服5mgVitB1和VitB2,收集4h尿液,用荧光法进行负荷试验。结果:VitB1组,所测29人中,15人缺乏,9人不足,2人正常,3人充裕;VitB2组,所测23人中,11人缺乏,12人不足,反映该部队全年约5%的发病是由于VitB1、VitB2缺乏不足所致。其原因为膳食摄入不够  相似文献   
105.
This study demonstrated that distinct patterns of active behaviors are produced by antidepressants that selectively inhibit norepinephrine (NE) or serotonin (5-HT) uptake in the rat forced swimming test (FST). A behavior sampling technique was developed to score the active behaviors swimming, climbing and diving, as well as immobility. The rat's behavior was recorded at the end of each 5-s period during the test session. The sampling technique was both reliable, as demonstrated by test-retest reliability and inter-rater reliability, and valid, as shown by comparison to the timing of behavior durations. Five different antidepressant drugs which block monoamine uptake and two 5-HT1A receptor agonists were shown to decrease immobility in the FST; however, they produced distinct patterns of active behaviors. The selective NE uptake inhibitors desipramine and maprotiline selectively increased climbing, whereas the selective serotonin reuptake inhibitors (SSRIs) fluoxetine, sertraline and paroxetine selectively increased swimming. The 5-HT1A receptor agonists 8-OH-DPAT and gepirone also selectively increased swimming. These results show that:1) SSRIs are not false negatives in the FST; 2) at least two behaviorally distinct processes occur in the FST; and 3) enhancement of NE neurotransmission may mediate climbing in the FST, whereas enhancement of 5-HT neurotransmission may mediate swimming.  相似文献   
106.
Background: As in many parts of the world, the Schirmer tear test is the main test used by optometrists in Saudi Arabia for assessing adequacy of tear production. Variability of the test has been reported in different ethnic groups but not in Arabs. This paper looks at the mean and repeatability of the values obtained by the Schirmer test in a normal Arab population Method: The test was performed on the right eyes of 23 young adult Saudi male subjects at five visits over two weeks. Result: Results showed that for each subject the test values were not repeatable, varying widely over the period of evaluation. The mean value was estimated at 10.6 mm and the 95 per cent confidence limits were 7.9 and 13.3 mm. It was also established that the greater the amount of tears, the greater the variability. Conclusion: This study supports the claim that the Schirmer test is not repeatable and hence is unreliable. Therefore, caution should be exercised in employing it for clinical diagnosis. (Clin Exp Optom 1995; 78: 5: 190–193)  相似文献   
107.
正常人口腔粘膜不同部位表面感觉的测试   总被引:1,自引:0,他引:1  
目的 建立正常人口腔粘膜不同部位表面感觉的正常参考值,并测试各年龄组感觉值是否存在差异。方法 利用动静两点辨别觉试验,测试90例健康人口腔粘膜不同部位的表面感觉。结果 舌尖感觉功能最好,其次为舌背、舌腹、颊粘膜、口底和硬腭。健康人的口腔粘膜不同部位的表面感觉随着年龄增长有显著性变化。结论 口腔粘膜不同部位感觉辨别力存在差异,健康人口底、舌腹、舌背、颊和硬腭粘膜感觉功能有增龄性变化。  相似文献   
108.
人大肠癌细胞体外常温及温热环境中药物敏感性试验   总被引:1,自引:0,他引:1  
用MTT比色法对20例大肠癌患者术后标本在常温及温热环境中进行体外药物敏感性试验,结果显示,某些药物在温热环境中,对癌细胞的杀伤作用有显著提高,此项试验为临床温热化疗法提供了理论依据。  相似文献   
109.
Summary. Fifty-six asthmatics from an asthma ward or from an asthma out-patient clinic were challenged with two low concentrations (0–03 and 0–012 mg) of metacholine chloride in order to assess the relationship between pronounced hyper-responsiveness and asthma severity in a clinical setting. Only inhaled bronchodilators were stopped before challenge. Asthma severity was assessed retrospectively and prospectively on the basis of treatment, number of days in hospital, intensive care, number of emergency visits and days on sick-leave. The results show that pronounced hyper-responsiveness (n= 28) is not associated with asthma severity. It is concluded that a single simplified test of pronounced bronchial hyper-responsiveness, performed without taking into consideration the actual state of the disease and without stopping all medication, is of no help in identifying the patients with the clinically most severe asthma and worst prognosis.,  相似文献   
110.
应用以化学交联法制备的布鲁氏菌16M抗原-羧化胶乳制剂的羧化胶乳凝集试验(LAT)、试管凝集试验(SAT)、虎红平板凝集试验(RBPT)以及酶联免疫吸附试验(ELISA)、半胱氨酸凝集试验(CYT),对在四省布鲁氏菌病疫区收集的部分人、畜血清中布氏菌抗体进行对比检测。结果表明,LAT较之RBPT具有更高的特异性;与SAT相比,无论阳性或阴性符合率均较一致。另外,LAT可检测血清中IgG、IgM两类布氏菌特异性抗体。因而本试验对人、畜布病的诊断具有特异、敏感和简便的优点,更宜在基层推广应用。  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