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   122120篇
  免费   7193篇
  国内免费   1597篇
耳鼻咽喉   1607篇
儿科学   3052篇
妇产科学   4192篇
基础医学   18614篇
口腔科学   3655篇
临床医学   9537篇
内科学   22637篇
皮肤病学   2527篇
神经病学   8192篇
特种医学   4111篇
外国民族医学   3篇
外科学   17317篇
综合类   5294篇
一般理论   38篇
预防医学   8866篇
眼科学   2881篇
药学   10361篇
中国医学   849篇
肿瘤学   7177篇
  2021年   1231篇
  2019年   1220篇
  2018年   1836篇
  2017年   1298篇
  2016年   1315篇
  2015年   1558篇
  2014年   2046篇
  2013年   2645篇
  2012年   3819篇
  2011年   4038篇
  2010年   2431篇
  2009年   2145篇
  2008年   3534篇
  2007年   3793篇
  2006年   3760篇
  2005年   3301篇
  2004年   3106篇
  2003年   2864篇
  2002年   2718篇
  2001年   6741篇
  2000年   6935篇
  1999年   5706篇
  1998年   1835篇
  1997年   1384篇
  1996年   943篇
  1995年   873篇
  1992年   3732篇
  1991年   3811篇
  1990年   3552篇
  1989年   3557篇
  1988年   3430篇
  1987年   3279篇
  1986年   3093篇
  1985年   2970篇
  1984年   2050篇
  1983年   1794篇
  1982年   985篇
  1979年   1910篇
  1978年   1185篇
  1977年   987篇
  1976年   919篇
  1975年   1192篇
  1974年   1361篇
  1973年   1413篇
  1972年   1358篇
  1971年   1247篇
  1970年   1138篇
  1969年   1122篇
  1968年   1026篇
  1967年   898篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
131.
The effect of bone drilling on pain in gonarthrosis   总被引:1,自引:0,他引:1  
Summary Seventy-seven patients with mild to moderate gonarthrosis of the knee were treated by subchondral bone drilling, and followed for from 2 to 7 years. Patients with generalised arthrosis benefited more than those with unicompartmental involvement. Pain, assessed by a visual analogue scale, was significantly reduced compared with a control group of 16 patients who had a diagnostic arthroscopy only. Drilling is a safe procedure with few complications and can be used in patients when more extensive surgery is not yet indicated or possible.
Résumé Vingt-sept cas d'arthrose légère ou modérée du genou, diagnostiqués par arthroscopie et traités par forage, ont été revus avec un recul moyen de 4 ans (de 2 à 7 ans). La douleur, évaluée selon la cotation VAS, était diminuée pendant 24 mois en moyenne (1 à 76) dans les deux tiers des cas. Les résultats étaient meilleurs chez les patients présentant une arthrose globale que chez ceux atteints d'une arthrose uni-compartimentale. Ils étaient obtenus aussi bien dans les cas douloureux au repos (n=39) que dans ceux douloureux lors de la mobilisation du genou (n=14). Les complications ont été exceptionnelles (n=1). La douleur était diminuée dans une proportion significativement supérieure dans les genoux traités par forage que dans un groupe de contrôle de 16 cas, n'ayant subi qu'une arthroscopie à visée diagnostique (p=0.006). Le forage est un procédé sûr, n'entraînant que de rares complications. Il est indiqué dans le traitement des douleurs du genou chez les patients ayant une arthrose légère ou modérée, lorsque des interventions plus importantes ne sont ni nécessaires, ni réalisables.
  相似文献   
132.
Prolongation of the action potential duration of dorsal root ganglion (DRG) neurons by low (nM) concentrations of opioids occurs through activation of excitatory opioid receptors that are positively coupled via Gs regulatory protein to adenylate cyclase. Previous results suggested GM1 ganglioside to have an essential role in regulating this excitatory response, but not the inhibitory (APD-shortening) response to higher (μM) opioid concentrations. Furthermore, it was proposed that synthesis of GM1 is upregulated by prolonged activation of excitatory opioid receptor functions. To explore this possibility we have utilized cultures of hybrid F11 cells to carry out closely correlated electrophysiological and biochemical analyses of the effects of chronic opioid treatment on a homogeneous population of clonal cells which express many functions characteristic of DRG neurons. We show that chronic opioid exposure of F11 cells does, in fact, result in elevated levels of GM1 as well as cyclic adenosine monophosphate (AMP), concomitant with the onset of opioid excitatory supersensitivity as manifested by naloxone-evoked decreases in voltage-dependent membrane K+ currents. Such elevation of GM1 would be expected to enhance the efficacy of excitatory opioid receptor activation of the Gs/adenylate cyclase/cyclic AMP system, thereby providing a positive feedback mechanism that may account for the remarkable supersensitivity of chronic opioid-treated neurons to the excitatory effects of opioid agonists as well as antagonists. These in vitro findings may provide novel insights into the mechanisms underlying naloxone-precipitated withdrawal syndromes and opioid-induced hyperalgesia after chronic opiatf addiction in vivo. © 1995 Wiley-Liss, Inc.  相似文献   
133.
134.
Clinicopathologic correlation of pigmented epiretinal membranes   总被引:1,自引:0,他引:1  
We performed clinicopathologic correlation on ten surgically removed pigmented epiretinal membranes causing macular pucker. All cases occurred in eyes with existing retinal holes or tears, including eight cases of macular pucker after previous retinal detachment. These cases probably represented a limited form of proliferative vitreoretinopathy. All membranes contained pigment epithelial cells with polarity, basement membrane, and melanosomes. Cytoplasmic melanin granules accounted for the clinical feature of pigmentation in these eyes.  相似文献   
135.
From Dec. 1990 to Dec. 1993, 278 cases of cervical spondylopathy were treated with electroacupuncture and massotherapy. The cure rate was 82.7%; but in the control group, it was only 61%, indicating that electroacupuncture may enhance the cure rate (P < 0.05). Of the 278 cases treated by three to five sessions, the pain and numbness disappeared in about 96% of the patients.  相似文献   
136.
A novel cardiokymograph system is introduced. The new system features a capacitance transducer with increased sensitivity and can be used in multichannel measurements. The novelty of this technique is the injection of a current into the patient coupled with the use of a capacitive displacement transducer and the possibility of multichannel monitoring. It provides for the possibility of removing breath noise when some signal processing technique, such as adaptive filtering, is used. Further investigation is needed to demonstrate clinical significance and pathologies.  相似文献   
137.
138.
139.
Changes in semen parameters are presented for 4708 patients treated for infertility. The largest group comprised patients with oligoasthenozoospermia of various grades (57.7%). Improvement in the seminal state was noted in 70.3%. The percentage of achieved normospermia increased proportionally to the initial semen state. Pregnancy rate also increased proportionally to the initial seminal state. Among the patients' wives 20.4% conceived: 28.2% of these pregnancies had occurred after having achieved normospermia, while in 71.8% the seminal states were still below the accepted normal values.  相似文献   
140.
2,3,7,8-Tetrachlorodibenzo-p-dioxin-induced oxidative stress in female rats   总被引:1,自引:0,他引:1  
Oxidative stress may play a role in the toxic manifestations of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). Therefore, the time-dependent effects of 100 micrograms TCDD/kg on various indices of oxidative stress including lipid peroxidation. DNA damage, membrane fluidity, calcium homeostasis, nonprotein sulfhydryl content, and NADPH content of hepatic subcellular fractions of female rats were followed for 12 days. Increases in lipid peroxidation of 400-500% occurred in mitochondrial and microsomal membranes and nuclei, with maximum increases occurring 5-6 days post-treatment. Decreases in the nonprotein sulfhydryl content of mitochondrial and microsomal fractions of approximately 80% were observed by Day 12 posttreatment. Membrane fluidity gradually decreased following administration of TCDD, with decreases of 30-40% being observed in mitochondria, microsomes, and plasma membranes. A sharp increase in the incidence of hepatic nuclear DNA single strand breaks was observed 3 days after treatment with an increase of approximately 600% by Day 9. Following the administration of TCDD, increases of 70-80% occurred in the calcium content of mitochondria and microsomes. An 18% increase in cytosolic calcium was present 12 days after the administration of TCDD. Cytosol and mitochondria both exhibited an initial increase in NADPH content following administration of TCDD, but by Day 12 both had decreased to approximately two-thirds of control values. The results clearly demonstrate that TCDD administration induces an oxidative stress in rat liver. The most pronounced effects were observed in membrane lipid peroxidation and DNA damage with gradual changes being observed in calcium and nonprotein sulfhydryl contents and membrane fluidity.  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