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   21553篇
  免费   1845篇
  国内免费   75篇
耳鼻咽喉   233篇
儿科学   636篇
妇产科学   493篇
基础医学   2559篇
口腔科学   472篇
临床医学   2594篇
内科学   3753篇
皮肤病学   249篇
神经病学   2005篇
特种医学   804篇
外科学   2808篇
综合类   772篇
一般理论   24篇
预防医学   2252篇
眼科学   485篇
药学   1630篇
  2篇
中国医学   47篇
肿瘤学   1655篇
  2022年   159篇
  2021年   290篇
  2020年   210篇
  2019年   260篇
  2018年   351篇
  2017年   271篇
  2016年   313篇
  2015年   357篇
  2014年   472篇
  2013年   734篇
  2012年   1061篇
  2011年   1038篇
  2010年   619篇
  2009年   585篇
  2008年   949篇
  2007年   1030篇
  2006年   949篇
  2005年   913篇
  2004年   902篇
  2003年   836篇
  2002年   854篇
  2001年   655篇
  2000年   601篇
  1999年   541篇
  1998年   338篇
  1997年   269篇
  1996年   290篇
  1995年   271篇
  1994年   224篇
  1993年   230篇
  1992年   406篇
  1991年   405篇
  1990年   432篇
  1989年   405篇
  1988年   406篇
  1987年   392篇
  1986年   372篇
  1985年   333篇
  1984年   258篇
  1983年   219篇
  1982年   151篇
  1981年   131篇
  1980年   126篇
  1979年   240篇
  1978年   170篇
  1977年   148篇
  1976年   136篇
  1975年   147篇
  1974年   165篇
  1973年   134篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
52.
53.
Corneal thickness measurements and endothelial cell counts were carried out in 34 patients undergoing treatment for glaucoma with 4% pilocarpine gel between 18 to 78 months after initiation of therapy. The corneal thickness and endothelial cell population were found to be within normal limits in all cases except two, one patient with increased corneal thickness who had recently undergone cataract and glaucoma filtering surgery and another patient with decreased cell count who had an old endothelial scar sustained prior to pilocarpine gel therapy. There was a very close correlation for both of these parameters noticed in patients treated with pilocarpine gel and in age-matched control group of patients with glaucoma. The present study has shown that there are no adverse corneal effects with pilocarpine gel therapy.  相似文献   
54.
OBJECTIVE: To examine corticomotoneuronal function in amyotrophic lateral sclerosis (ALS) patients carrying superoxide dismutase 1 (SOD1) mutations using peristimulus time histograms (PSTH). METHODS: Six I113T, 3 A4V, one G41D and one G114A patient were studied along with 21 healthy control subjects. Analyses included comparison with previously reported data from 8 D90A homozygous and 12 sporadic ALS (SALS) patients examined by the authors using identical methodology. RESULTS: Cortical threshold was significantly reduced in A4V patients (41.3%) compared to I113T (58%), SALS (57%) and D90A (71%) patients, as well as healthy controls (49.7%). Estimated excitatory postsynaptic potentials (EPSPs) were significantly larger in A4V patients (4.39 mV) compared to healthy controls (2.95 mV), I113T (2.71 mV) and SALS (2.39 mV) patients. Clinical features and PSTH parameters in I113T were similar to SALS, however, PSTH primary peaks (PP) were significantly more dispersed, 9.5 ms compared to 4ms in SALS. PSTHs from single G41D and G114A patients were unremarkable, apart from large EPSP amplitudes in the G114A patient. CONCLUSIONS: ALS patients with A4V and I113T SOD1 mutations have distinctive corticomotoneuronal changes that are different from those in D90A homozygous and SALS patients. SIGNIFICANCE: PSTH studies should be considered for future in vivo studies of SOD1 pathophysiology in ALS.  相似文献   
55.
56.
57.
58.
This paper reports the results of a survey in which pregnant women in London and Edinburgh were asked about their knowledge and understanding of the recent recommendations of expert committees (James, 1983; DHSS, 1984). In general, Londoners had a better understanding, although in both regions manual groups were less knowledgeable, with the Edinburgh manual group the least well informed.  相似文献   
59.
1. The kidney bean lectin, phytohaemagglutinin (PHA), induced a marked atrophy of skeletal muscle which was evident from the changes in tissue composition (protein, RNA, DNA and polyamine content) and from the reduction in weight and protein synthesis of hind leg muscles of rats fed on kidney bean-diets for four days. The beta-adrenoceptor agonist, clenbuterol, induced skeletal muscle hypertrophy by transiently stimulating protein synthesis. As a consequence, the muscle loss caused by a short exposure to PHA was, in part, ameliorated by clenbuterol treatment. 2. Cardiac muscle was affected to a lesser extent than skeletal muscle by both clenbuterol and the lectin. However, there was evidence that protein synthesis in heart was reduced by PHA. 3. PHA had opposite effects on the gut, the lectin-induced hyperplasia of the jejunum was accompanied by a large increase in protein synthesis. Clenbuterol alone had no effect on the jejunum whereas a combination of PHA and clenbuterol appeared to exacerbate the effect of the lectin on gut. 4. Both the lectin-induced gut growth and the hypertrophy of skeletal muscle caused by clenbuterol were preceded by the accumulation of polyamines in the respective tissues. Of particular note was the observation that a significant increase in the proportion of the intraperitoneally injected 14C-labelled spermidine or putrescine taken up by the growing tissues could be detected by the second day. Therefore, the measurement of uptake of labelled polyamines may be used as a sensitive indicator of early alterations in tissue metabolism.  相似文献   
60.
OBJECTIVE: This study prospectively evaluates the effectiveness and patient acceptability of professionally-led support groups in alleviating psychologic distress in infertility patients. METHOD: Sixty-four consecutive patients in a university hospital infertility program were administered a battery of psychologic tests before and after attendance at an 8 weekly session support group. The comparison group consisted of 35 consecutive infertility referrals to the same unit who were not initially offered the support group and were similarly tested over an 8 week period. RESULTS: Support group patients had significantly greater (p less than or equal to 0.01) entry than exit scores on several measures of psychologic distress and depression (the Beck Depression Inventory, the Hamilton Rating Scale for Depression, and the Global Severity Index, Anxiety, Depression, Hostility and Obsessive Compulsive Subscales of the Brief Symptom Inventory). The Avoidance Coping Style on the Moos Coping Responses Inventory was correlated with a higher Global Severity Index (p less than or equal to 0.01). Comparison group patients had similar psychometric scores to the support group patients at entry but showed no change over 8 weeks. Attenders expressed a high rate of satisfaction with the support group. CONCLUSIONS: Professionally-led support groups are a highly acceptable and effective intervention in self-referred patients in alleviating psychological distress related to infertility.  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