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   171662篇
  免费   9845篇
  国内免费   461篇
耳鼻咽喉   2235篇
儿科学   5581篇
妇产科学   3590篇
基础医学   23239篇
口腔科学   7526篇
临床医学   12578篇
内科学   38443篇
皮肤病学   4346篇
神经病学   14301篇
特种医学   5437篇
外国民族医学   26篇
外科学   21112篇
综合类   1405篇
现状与发展   1篇
一般理论   64篇
预防医学   17888篇
眼科学   3169篇
药学   10464篇
中国医学   688篇
肿瘤学   9875篇
  2023年   887篇
  2022年   1934篇
  2021年   3614篇
  2020年   2428篇
  2019年   3418篇
  2018年   4829篇
  2017年   3626篇
  2016年   3361篇
  2015年   3943篇
  2014年   5421篇
  2013年   6859篇
  2012年   10672篇
  2011年   11144篇
  2010年   5667篇
  2009年   5093篇
  2008年   8635篇
  2007年   9256篇
  2006年   8567篇
  2005年   8859篇
  2004年   8323篇
  2003年   7609篇
  2002年   5677篇
  2001年   4987篇
  2000年   4977篇
  1999年   4391篇
  1998年   1595篇
  1997年   1340篇
  1996年   1321篇
  1995年   1123篇
  1994年   1127篇
  1993年   1021篇
  1992年   2671篇
  1991年   2597篇
  1990年   2362篇
  1989年   2380篇
  1988年   2159篇
  1987年   1985篇
  1986年   1857篇
  1985年   1775篇
  1984年   1272篇
  1983年   1032篇
  1982年   578篇
  1981年   536篇
  1980年   507篇
  1979年   938篇
  1978年   621篇
  1977年   489篇
  1975年   551篇
  1974年   555篇
  1973年   552篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
This research presents reports of cases where a biocompatible and alloplastic biomaterial—Bioplastique—was used, associated with conventional plastic surgery or as a complement to it, with the aim of achieving a better final aesthetic result. Four cases are presented where Bioplastique was used in association with rhytidoplasty, rhinoplasty, and other surgical techniques. This material has shown itself to be appropriate to complement surgery; achieving a final result which would not be possible without any resort to a complement or any other hard procedure by the surgeon and is not more traumatic for the patient.  相似文献   
72.
Contradictory results have been reported about the inhibitory input to the medial rectus subdivision of the oculomotor nucleus of the cat. In the present ultrastructural study, we quantified the GABAergic and glycinergic terminals in the various subdivisions of the rabbit oculomotor nucleus with the use of post-embedding immunocytochemistry combined with retrograde tracing of horseradish peroxidase. The density of the GABAergic input to the medial rectus subdivision was as substantial as that to the other subdivisions and the postsynaptic distribution of the GABAergic and glycinergic innervation did not differ among the different oculomotor subdivisions.  相似文献   
73.
74.
The pharmacokinetics of midazolam and its metabolites were studied in 17 patients on mechanical ventilation in a general intensive care unit who were receiving a continuous intravenous infusion of midazolam, adjusted according to the level of induced sedation. Three patients were studied twice. Serum midazolam and alpha-hydroxymidazolamglucuronide levels were determined during and after infusion. The sedation level was scored on a four-point scale. Half of the observed patients were still drowsy or asleep 10 hours after termination of midazolam infusion. In only one patient was midazolam serum elimination half-life less than 2 hours and in six patients the half-life was greater than 10 hours. A wide range of midazolam serum levels was associated with adequate sedation, and similarly the midazolam levels at the moment of awakening were highly variable. The serum concentration ratio of midazolam/alpha-hydroxymidazolamglucuronide at the end of the infusion varied from 0.03 to 15.6. Renal function could account for only a part of this variation.  相似文献   
75.
A 67-year-old man with non-insulin-dependent diabetes mellitus progressively developed, over a 2-year period, lower extremity sensory and motor defects associated with impaired bladder function and perineal and perianal sensation related to a disease of the conus medullaris extending from T12 to S5. The magnetic resonance imaging scan suggested myelomalacia and the diagnosis of progressive necrotic myelopathy was confirmed by surgical intervention.  相似文献   
76.
Total global biodiversity is estimated at between 3 and 500 × 106 species of prokaryote and eukaryote organisms spread across 70 or more phyla. The marine macrofauna alone are estimated between 0.5 and 30 × 106 species and represents a broader range of taxonomic diversity than that found in the terrestrial environment, which has been the traditional source of natural products. With a typical eukaryote possessing 50,000 genes, the global marine macrofauna are the source of 2.5 × 1010 to 1.5 × 1012 primary products and an associated extensive range of secondary products. However, only a few thousand novel compounds from marine organisms have been described. These compounds have proven unique in chemical and pharmacological terms but, as yet, no therapeutic agents have resulted. Given a broader drug discovery strategy, and facilitated by technological advances, it is predicted that the characterisation of marine chemical diversity will be accelerated. Strategies for drug discovery from the virtually untapped chemical diversity of marine organisms are discussed. © 1994 Wiley-Less, Inc.  相似文献   
77.
Dexenfluramine, an effective and safe serotoninergic drug with anorectic and possible food-selection-tuning properties, was investigated in a placebo-controlled study of 1 year's duration in severe and refractory obesity. The aim of the study was to assess weight loss, and changes in cardiovascular risk factors, food intake and eating behaviour. Dexfenfluramine- and placebo-treated patients achieved a similar weight loss (greater than 10% of initial weight, by 39.5 and 30.0%, greater than 20% of initial overweight by 42.1% and 32.5% and greater than 10 kg by 41.4 and 33.3%, respectively, of the initial cohorts). Furthermore, the decreases in weight (10.7 vs. 8.0 kg), in body mass index (3.9 vs. 2.9 kg m2) and in waist/hip ratio (0.04 vs. 0.02) were not significantly different. After discontinuation of the drug, the increase in weight (2.8 vs. 1.0 kg) was significantly higher in the dexfenfluramine-treated group. Except for a borderline better effect on glucose of dexfenfluramine, both groups showed similar beneficial changes in food intake and cardiovascular risk factors. Eating behaviour in response to emotional and external stimuli was comparable in the two groups, but placebo-treated patients had to restrain their eating more in order to achieve the same weight loss. Notwithstanding the fact that weight losses and an associated amelioration of health-risk factors were of similar magnitude in dexfenfluramine- and placebo-treated patients, dexfenfluramine might have a useful role in promoting a less stressed adherence to prolonged restriction of energy intake in the severe and refractory obese subject.  相似文献   
78.
Hydrocephalus and cavernoma of the cauda equina   总被引:1,自引:0,他引:1  
F Ramos  B de Toffol  B Aesch  M Jan 《Neurosurgery》1990,27(1):139-142
The association of a tumor of the cauda equina and hydrocephalus is unusual. We report a case of hydrocephalus with normal pressure associated with an equally rare affliction, a cavernous angioma of the cauda equina, which regressed after surgical ablation. The physiological mechanism involved is discussed.  相似文献   
79.
To our knowledge, only 3 patients with an extragonadal germ cell tumor of the prostate have been described in the literature until now. We here present a patient with a germ cell tumor arising in the retroperitoneum, invading the prostate, which was successfully treated by a combination of chemotherapy and nonmutilating surgery.  相似文献   
80.
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