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   8479篇
  免费   648篇
  国内免费   30篇
耳鼻咽喉   82篇
儿科学   300篇
妇产科学   191篇
基础医学   1174篇
口腔科学   140篇
临床医学   948篇
内科学   1561篇
皮肤病学   119篇
神经病学   859篇
特种医学   381篇
外国民族医学   2篇
外科学   1094篇
综合类   219篇
一般理论   18篇
预防医学   846篇
眼科学   159篇
药学   598篇
中国医学   8篇
肿瘤学   458篇
  2021年   92篇
  2019年   72篇
  2018年   131篇
  2017年   108篇
  2016年   130篇
  2015年   117篇
  2014年   175篇
  2013年   239篇
  2012年   396篇
  2011年   359篇
  2010年   227篇
  2009年   388篇
  2008年   328篇
  2007年   362篇
  2006年   334篇
  2005年   383篇
  2004年   383篇
  2003年   293篇
  2002年   317篇
  2001年   285篇
  2000年   304篇
  1999年   260篇
  1998年   110篇
  1997年   101篇
  1996年   83篇
  1995年   77篇
  1994年   80篇
  1993年   66篇
  1992年   207篇
  1991年   187篇
  1990年   180篇
  1989年   138篇
  1988年   158篇
  1987年   160篇
  1986年   172篇
  1985年   141篇
  1984年   108篇
  1983年   89篇
  1982年   68篇
  1979年   84篇
  1978年   59篇
  1976年   58篇
  1975年   56篇
  1974年   63篇
  1973年   81篇
  1972年   60篇
  1971年   73篇
  1970年   60篇
  1969年   91篇
  1968年   72篇
排序方式: 共有9157条查询结果,搜索用时 15 毫秒
81.
PURPOSE: This is a retrospective study comparing the clinical data and morbidity of transperitoneal radical nephrectomy (TRN) and simple nephrectomy. MATERIAL AND METHODS: From 1st January, 1989 to 1st January, 1996 a total of 90 simple nephrectomies and from 1st January, 1996 to 1st August, 1999 a number of 85 TRN were performed at the Department of Urology of the Saint Stephen Hospital. The analysis of clinical data included operative time, length of analgesics, postoperative hospital stay and blood loss, as well as morbidity. RESULTS: The mean operative time for TRN was 170 min., being 95 min. for simple nephrectomy. The mean blood loss for TRN was 250 ml, and 400 ml for simple nephrectomy. There were different types of morbidity for TRN and simple nephrectomy. The complications of TRN mean minimal risk and easy correctibility. CONCLUSION: Our results demonstrate an overall clear advantage of TRN when compared to simple nephrectomy.  相似文献   
82.
Amphetamine stimulates locomotor activity, in large part by activating central dopaminergic systems. Serotonin shares on overlapping distribution with dopamine and has been shown to modulate dopaminergic function and dopamine-mediated behaviors. The present study examined whether increasing serotonergic function, via the selective serotonin reuptake inhibitor fluoxetine, would alter the stimulatory effects of amphetamine on locomotor activity and dopamine overflow in the nucleus accumbens. In addition, the present study determined whether fluoxetine treatment would alter the metabolism of amphetamine. Results show that 5.0 mg/kg fluoxetine potentiated the locomotor activity induced by amphetamine (0.5–1.0 mg/ kg), and enhanced the increased dopamine overflow in the nucleus accumbens induced by amphetamine. Fluoxetine treatment also resulted in a higher concentration of amphetamine in the CNS. Together, these findings indicate that acute fluoxetine treatment potentiates the locomotor stimulating and dopamine activating effects of amphetamine. Further, the results indicate that fluoxetine potentiates the effects of amphetamine by decreasing the metabolism of amphetamine, probably through inhibition of cytochrome P450 isozymes. Received: 5 May 1998/Final version: 7 July 1998  相似文献   
83.
Previously, we have demonstrated that 5-hydroxytryptamine (5-HT) injected into the nucleus accumbens attenuates the potentiating effects of d-amphetamine on responding for conditioned reward (CR). The present studies examined the 5-HT receptor involved in this effect by investigating the effects of 5-HT agonists with differing affinities for 5-HT1 and 5-HT2 receptors on d-amphetamine-induced potentiation of responding for CR. Rats were trained to associate a light/tone stimulus (subsequently the CR) with water delivery. In a test phase, they were allowed access to a lever delivering the CR, and an inactive (NCR) lever. Responding on the CR lever was greater than responding on the NCR lever, indicating that the light/tone stimulus functioned as a CR. Responding for the CR was selectively potentiated by injections of d-amphetamine (10 μg) into the nucleus accumbens. This effect was reduced by injections into the nucleus accumbens of 5-CT (0.5 and 1 μg), RU24969 (10 μg), CP93,129 (1.25 and 2.5 μg) but not by DOI (10 μg) or 8-OH-DPAT (5 μg). The lower doses of 5-CT and CP93,129 did not reduce baseline responding for CR, or responding for water in a separate group of animals, indicating that the effects of these drugs were behaviourally selective. The higher doses abolished the CR effect, and in the case of 5-CT and RU24969 also reduced responding for water. All of the effective drugs share in common the ability to stimulate 5-HT1B receptors, albeit with differing selectivities. The effect of CP93,129, the most selective of the 5-HT1B agonists, to inhibit the response-potentiating effect of d-amphetamine was reversed by the5-HT1B/1D antagonist GR127935 (3 mg/kg). The results indicate that activation of 5-HT1B receptors within the nucleus accumbens attenuates the effects of a dopamine-dependent behaviour, and that activation of these receptors can oppose the behavioural effects of elevated mesolimbic dopamine transmission. Received: 22 April 1998/Final version: 28 July 1998  相似文献   
84.
Injection of the GABA(A) agonist muscimol into the dorsal raphe nucleus produces a marked and selective increase in voluntary ethanol intake. The purpose of the present study was threefold: first, to demonstrate that the effect of muscimol on ethanol consumption is mediated by GABA(A) receptors; secondly, to test the generalizability of this effect by examining the effects of another GABA(A) agonist, THIP, on ethanol drinking; and finally, to examine whether GABA(B) receptors within the dorsal raphe also play a role in modifying voluntary ethanol consumption under the same experimental conditions. Rats were trained to drink a 12% ethanol solution in a limited access paradigm with water concurrently available. Muscimol (50ng) injected into the dorsal raphe enhanced intake by at least 100%. Peripheral administration of the GABA(A) antagonist bicuculline (4mg/kg), but not the 5-HT(1A) antagonist (+)- WAY100135 (1 and 3mg/kg), antagonized the stimulatory effect of muscimol at a dose which, when administered alone, did not alter ethanol intake. This supports the suggestion that the effect of muscimol is mediated via GABA(A) receptors. This conclusion was further supported by the finding that another GABA(A) agonist, THIP (500ng), also selectively increased ethanol intake in this paradigm. Injection of bicuculline (60ng) into the dorsal raphe reduced ethanol intake, but also appeared to reduce water intake. Finally, intra-dorsal raphe injection of the GABA(B) agonist baclofen (62.5 and 125ng) did not produce any change in ethanol or water consumption. Together, these findings suggest that enhancement of GABAergic activity in the dorsal raphe increased voluntary ethanol intake via activation of GABA(A) but not GABA(B) receptors.  相似文献   
85.
Medicated compress for blister treatment   总被引:1,自引:1,他引:0       下载免费PDF全文
  相似文献   
86.
87.
K R Stevens  W S Fletcher  C V Allen 《Cancer》1978,41(5):2065-2071
Preoperative irradiation for adenocarcinoma of the rectum and sigmoid does not always limit the surgery to an abdominoperineal resection. From 1960 to 1976 anterior resection and primary anastomosis of the bowel has been performed in 13 patients with adenocarcinoma of the rectum and sigmoid whose tumor had been irradiated with 5000 rads with small pelvic fields. The inferior surgical resection line was within or very near the edge of the radiation field in 10 patients. In no instance was the superior resection line irradiated. Compared to a group of 79 patients treated with anterior resection only, the preoperatively irradiated patients had lower incidence of pelvic and anastomotic tumor recurrence, but a higher incidence of anastomotic leak and subsequent adhesions and intestinal obstruction. We stress that if irradiated rectum is considered for forming the anastomosis, a temporary "protective colostomy" should be strongly considered at the time of the surgery.  相似文献   
88.
89.
Selecting opportunities for process improvements in the health information management department can be achieved through a formal system analysis. This article covers the step-by-step examination of one department's quality improvement efforts.  相似文献   
90.
In Langerhans' cell histiocytosis, the prognostic significance of pulmonary disease is controversial. The clinical and radiological features and lung function tests of Langerhans' cell histiocytosis patients presenting to a single tertiary referral center between 1981 and 1987 were reviewed. Age at diagnosis ranged from 2 weeks to 16 years (median 1.7 years) and the male-female ratio was 2.4:1. No child presented with lung involvement alone. In 18 (40%) of 45 patients with multisystem disease there was clinical and/or radiological evidence of lung pathology. Another 6 children (13%) with normal chest roentgenograms had abnormal lung function tests, suggesting subclinical ("occult") involvement. Those with overt lung disease tended to present at a younger than average age (median 0.6 years). The most common functional disturbance was reduced lung or respiratory compliance with reduced lung volumes. Patients with and without lung involvement showed a similar pattern of involvement of other organs, with skin and bone most commonly affected. Of the 45 children with multisystem disease, 38 (84%) survived 2 to 7 years after diagnosis; there was a similar proportion of deaths in children with and without lung involvement. It is concluded that lung involvement occurs in nearly half of young children with multisystem Langerhans' cell histiocytosis but does not adversely affect outcome.  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