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   407篇
  免费   13篇
  国内免费   38篇
儿科学   10篇
妇产科学   3篇
基础医学   48篇
口腔科学   55篇
临床医学   52篇
内科学   70篇
皮肤病学   1篇
神经病学   30篇
特种医学   105篇
外科学   26篇
综合类   12篇
预防医学   13篇
药学   28篇
肿瘤学   5篇
  2022年   3篇
  2020年   2篇
  2018年   2篇
  2017年   3篇
  2016年   3篇
  2015年   5篇
  2014年   8篇
  2013年   15篇
  2012年   10篇
  2011年   9篇
  2010年   4篇
  2009年   10篇
  2008年   22篇
  2007年   33篇
  2006年   15篇
  2005年   20篇
  2004年   10篇
  2003年   9篇
  2002年   10篇
  2001年   12篇
  2000年   16篇
  1999年   9篇
  1998年   15篇
  1997年   10篇
  1996年   11篇
  1995年   18篇
  1994年   8篇
  1993年   11篇
  1992年   6篇
  1991年   6篇
  1990年   12篇
  1989年   21篇
  1988年   11篇
  1987年   10篇
  1986年   10篇
  1985年   7篇
  1984年   6篇
  1983年   6篇
  1982年   8篇
  1981年   10篇
  1980年   7篇
  1979年   2篇
  1978年   2篇
  1977年   4篇
  1976年   4篇
  1975年   5篇
  1972年   2篇
  1970年   2篇
  1960年   2篇
  1934年   2篇
排序方式: 共有458条查询结果,搜索用时 15 毫秒
91.
Synthetic fragments of galanin 1-29 were administered intraventricularly or into the paraventricular nucleus of the hypothalamus for analysis of the critical amino acid sequence necessary to stimulate feeding behavior in rats. Galanin 1-29 and galanin fragment 1-16 significantly increased feeding at doses of 6 nmol microinjected into the lateral ventricles and 1 nmol microinjected into the hypothalamus. There was no significant effect of D-TRP2 galanin 1-16 microinjected into the hypothalamus, and no significant effect of galanin fragments 1-9, 10-20, 12-29, 17-29, or 21-29 microinjected intraventricularly, on food consumption. Synthetic fragments of galanin 1-29 were assayed for displacement of 125I-galanin 1-29 binding to rat hypothalamic membranes. The efficacies of the galanin fragments in the feeding paradigm were consistent with the relative affinities of these fragments for the hypothalamic galanin receptor in equilibrium binding experiments. The first 16 N-terminal amino acids appear to contain galanin agonist activity on increasing food consumption and to bind to the galanin receptor in the rat hypothalamus.  相似文献   
92.
93.
94.
人白血病HL60细胞的分化状态对细胞凋亡的影响   总被引:2,自引:0,他引:2  
用细胞培养和流式细胞术等方法,研究人白血病HL60细胞诱导分化后,对三尖杉酯碱(Har)和喜树碱(Cam)诱导细胞凋亡的影响。结果表明,12-豆蔻酰及13-乙酸佛波酯以16nmol·L-1浓度处理HL60细胞24h,细胞向单核/巨噬细胞方向分化,阻断于G1期;分化细胞抗Har和Cam诱导的细胞凋亡,但其c-myc基因的表达无变化。1.4%二甲基亚砜处理HL60细胞48h,细胞向粒细胞方向分化,阻断于G1期;分化细胞抗Cam,而不抗Har诱导的细胞凋亡;分化细胞的c-myc基因表达明显下降。结果提示,人白血病HL60细胞的分化状态,明显影响三尖杉酯碱和喜树碱诱导的细胞凋亡,但可能与c-myc基因的表达变化无关。  相似文献   
95.
该指南是英国皮肤科医师协会针对皮肤科医生制定的 ,反映了当前文献报道中的最新研究资料。在解释这些资料时应慎重 ,因为未来的研究可能会改变现有的结论或推荐方案。在应用该指南时 ,需因人而异 ,因地制宜。遵守指南并不能确保万无一失 ,因此对实施指南时的偏离不应都归咎于疏忽 (该指南并不能保证面面俱到 ,在实际应用中可加以变通 )。简介 :甲真菌病是最常见的皮肤病之一。英国对 10 0 0 0人进行的一项大规模问卷调查显示发病率为 2 71%。芬兰和美国最近的真菌学对照调查表明 ,发病率为 7%~ 10 %。甲真菌病发病率的升高和有效抗真菌新…  相似文献   
96.
Middleton  WD; Melson  GL 《Radiology》1989,173(2):427-429
To determine the appearance of artifactual renal duplication in ultrasound (US) imaging, the authors analyzed 22 examples of such duplication in 20 patients. The artifact appeared as a duplication of the collecting system in 18, as a suprarenal mass in three, and as upper-pole cortical thickening in one. It occurred in the left kidney in 15 patients, in the right kidney in three, and bilaterally in two. To determine the frequency of the artifact, 50 additional patients were scanned. It was identified in eight of these patients. Imaging characteristics and the results of in vitro modeling proved the artifact was due to sound beam refraction between the lower pole of the spleen or liver and adjacent fat. This artifact is much more common in the left kidney and occurs more frequently in obese patients. Knowledge of the appearance and cause of this artifact should help radiologists avoid diagnostic errors.  相似文献   
97.
A new class of radio frequency (RF) coils for magnetic resonance (MR) imaging and spectroscopy is introduced. The coils consist of two loop-gap resonators of equal diameters positioned along a common axis. They are tuned to the mode in which the current in the two loops flows in opposite directions. These coils are "decoupled" from a uniform excitation field of arbitrary orientation (including circularly polarized fields) by intrinsic decoupling and by means of back-to-back fast recovery diodes. Measurements made with the coils and a phantom saline tank indicate that the signal-to-noise ratio obtainable with these coils is almost identical to that obtained with single loops. Imaging of several anatomic areas, including knee, wrist, and shoulder, has been performed with a 1.5-T MR system that uses circularly polarized RF. A small series of patients with torn rotator cuffs underwent imaging. Difficulties in establishing the diagnosis with MR imaging because of anatomic complexity are illustrated. The value of pulse sequences with long repetition times to increase the signal intensity of fluid in the joint is shown.  相似文献   
98.
Clinical pathogenesis and diagnosis of osteoarthritis   总被引:1,自引:0,他引:1  
New insights into the metabolism of cartilage have increased respect for efforts designed to prevent osteoarthritis. The aging of the population adds to the desire to diagnose and manage the disease before patients become seriously disabled.  相似文献   
99.
100.
This study was conducted to analyse the effect of childhood-onset diabetes mellitus on adult height. The height at time of diagnosis of 35 children with insulin-dependent diabetes mellitus (IDDM) was compared with growth reference data. Predictions of the adult height were made at the time of diagnosis using the target height and the Tanner-Whitehouse II method. The adult height was compared with both the predicted values and the height of healthy adults. The height at time of diagnosis of the prepubertal children was increased compared with growth reference data, in contrast to pubertal children who had normal heights. Only the prepubertal boys were taller at time of diagnosis. The adult height of the prepubertal patients was taller than growth reference data. The mean adult height in all patients did not differ significantly from the predicted heights. In conclusion, the increased height at the start of IDDM in prepubertal children persists until adulthood.  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