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   3429篇
  免费   234篇
  国内免费   23篇
耳鼻咽喉   20篇
儿科学   126篇
妇产科学   100篇
基础医学   352篇
口腔科学   78篇
临床医学   274篇
内科学   1029篇
皮肤病学   33篇
神经病学   350篇
特种医学   202篇
外国民族医学   2篇
外科学   414篇
综合类   12篇
预防医学   105篇
眼科学   13篇
药学   162篇
中国医学   5篇
肿瘤学   409篇
  2023年   29篇
  2022年   39篇
  2021年   62篇
  2020年   55篇
  2019年   54篇
  2018年   67篇
  2017年   40篇
  2016年   62篇
  2015年   88篇
  2014年   91篇
  2013年   131篇
  2012年   173篇
  2011年   173篇
  2010年   112篇
  2009年   100篇
  2008年   161篇
  2007年   175篇
  2006年   157篇
  2005年   159篇
  2004年   149篇
  2003年   128篇
  2002年   109篇
  2001年   110篇
  2000年   108篇
  1999年   100篇
  1998年   67篇
  1997年   78篇
  1996年   69篇
  1995年   52篇
  1994年   57篇
  1993年   43篇
  1992年   66篇
  1991年   48篇
  1990年   50篇
  1989年   75篇
  1988年   60篇
  1987年   48篇
  1986年   49篇
  1985年   49篇
  1984年   28篇
  1983年   27篇
  1982年   26篇
  1981年   17篇
  1980年   19篇
  1979年   20篇
  1978年   18篇
  1977年   21篇
  1975年   12篇
  1974年   9篇
  1972年   13篇
排序方式: 共有3686条查询结果,搜索用时 15 毫秒
1.
2.
3.
Purpose: To evaluate the rate and onset of intraoperative and postoperative complications post-phacoemulsification. Methods: One hundred sixty-two eyes of 145 patients with uveitis who underwent phacoemulsification between 2006 and 2009 were identified through surgical record review. Fifty-nine eyes of 46 patients met the inclusion criteria. Hazard ratio (HR) and Kaplan-Meier survival probability were calculated for each class of uveitis. Results: Macular edema (ME) resulted to be associated to chronic postoperative inflammation (r?=?0.6; p?=?0.00) and mostly related to patients who presented more than one postoperative relapse/year (r?=?0.2; p?=?0.02). Fuchs uveitis resulted to be a risk factor for posterior capsule opacification (PCO) (HR 3.36 IC95%1.0-10.5; p?=?0.03). Hypotony and elevated intraocular pressure (IOP) were detected in the anterior uveitis group (0.02 EY). Conclusion: The HR to develop ME was significantly related to chronic anterior uveitis. PCO and elevated IOP are most frequent in Fuchs uveitis. The postoperative visual acuity result was good among all the uveitis groups.  相似文献   
4.
We report on 3 patients with pseudoathetosis, which are involuntary, slow, writhing movements due to loss of proprioception.  相似文献   
5.
Ruggieri  PM; Laub  GA; Masaryk  TJ; Modic  MT 《Radiology》1989,171(3):785-791
The technique and feasibility of magnetic resonance (MR) angiography of intracranial vessels were studied in 35 healthy volunteers. Variations in image orientation, repetition time (TR), and flip angle were evaluated to determine their effects on flow-related enhancement. Gradient modifications--including echo time (TE), motion compensation, bandwidth, and field of view--were also studied in an effort to reduce motion-induced phase shifts. Results indicated that a FISP (fast imaging with steady precession) sequence with a TR of 50 msec, TE of 15 msec, velocity compensation in the read and section-select directions, acceleration compensation in the read direction, anisotropic volume, and a 1.25-mm partition thickness produced three-dimensional angiographic MR images that were accurate and reproducible in the depiction of the major intracranial vessels. Difficulties with field of view, persistent signal void secondary to higher-order motion, and spatial resolution remain major problems requiring additional study.  相似文献   
6.
Prostaglandins (PGs) A1 and J2 were found to potently suppress the proliferation of human K562 erythroleukemia cells and to induce the synthesis of a 74-kDa protein (p74) that was identified as a heat shock protein related to the major 70-kDa heat shock protein group. p74 synthesis was stimulated at doses of PGA1 and PGJ2 that inhibited cell replication, and its accumulation ceased upon removal of the PG-induced proliferation block. PGs that did not affect K562 cell replication did not induce p74 synthesis. p74 was found to be localized mainly in the cytoplasm of PG-treated cells, but moderate amounts were found also in dense areas of the nucleus after PGJ2 treatment. p74 synthesis was not necessarily associated with cytotoxicity or with inhibition of cell protein synthesis. The results described support the hypothesis that synthesis of the 70-kDa heat shock proteins is associated with changes in cell proliferation. The observation that PGs can induce the synthesis of heat shock proteins expands our understanding of the mechanism of action of these compounds whose regulatory role is well known in many physiological phenomena, including the control of fever production.  相似文献   
7.
Motor evoked potentials (MEPs) from the arms and legs to transcranial stimulation of the motor cortex and somatosensory evoked potentials (SSEPs) from stimulation of the nerves of the arms and legs, were recorded in 11 patients with hereditary spastic paraplegia. Electrophysiological abnormalities were found to be distributed differently among the systems examined; the longer the pathway, the higher the incidence and severity of impairment. MEPs from the leg were either absent or clearly reduced or prolonged in all patients. Eight patients showed abnormal cortical SSEPs on stimulation of the leg (absent or reduced responses in four, slowed central conduction velocity in seven), but only two of these patients had abnormal MEPs from the arm (absent responses). Cortical SSEPs on stimulation of the median nerve were reduced in two patients. Mean values of amplitude and central conduction velocity for MEPs and SSEPs from the leg were significantly different between patients and controls. Such differences were not found for either MEPs or SSEPs from the arm. This distribution of abnormalities, which suggests a differential involvement of the spinal pathways, parallels the reported pathological pattern in which degeneration of axons is more common and severe in the motor and sensory fibres supplying the leg.  相似文献   
8.
Summary Three species of digeneans including 1 Gorgoderidae (Plesiochorus cymbiformis) from the urinary bladder, 1 Plagiorchiidae (Enodiotrema megachondrus) from the duodenum, and 1 Pachypsolidae (Pachypsolus irroratus) from the stomach were recovered from 2 of 3 olive ridley turtles (Lepidochelys olivacea) found stranded along the Pacific coast of Costa Rica. All trematodes represent new locality records. Histopathological changes associated with eggs of cardiovascular flukes (Digenea, Spirorchiidae) were described from the lungs, spleen, and intestine of a single turtle.  相似文献   
9.
10.
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