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   1222篇
  免费   88篇
  国内免费   63篇
耳鼻咽喉   19篇
儿科学   54篇
妇产科学   5篇
基础医学   163篇
口腔科学   45篇
临床医学   121篇
内科学   216篇
皮肤病学   31篇
神经病学   73篇
特种医学   282篇
外科学   85篇
综合类   58篇
预防医学   72篇
眼科学   10篇
药学   109篇
中国医学   1篇
肿瘤学   29篇
  2023年   4篇
  2022年   5篇
  2021年   16篇
  2020年   11篇
  2019年   9篇
  2018年   10篇
  2017年   13篇
  2016年   24篇
  2015年   18篇
  2014年   30篇
  2013年   28篇
  2012年   29篇
  2011年   26篇
  2010年   29篇
  2009年   36篇
  2008年   27篇
  2007年   54篇
  2006年   26篇
  2005年   43篇
  2004年   26篇
  2003年   20篇
  2002年   25篇
  2001年   40篇
  2000年   25篇
  1999年   35篇
  1998年   63篇
  1997年   66篇
  1996年   62篇
  1995年   58篇
  1994年   35篇
  1993年   46篇
  1992年   24篇
  1991年   28篇
  1990年   38篇
  1989年   66篇
  1988年   45篇
  1987年   46篇
  1986年   25篇
  1985年   26篇
  1984年   15篇
  1983年   9篇
  1982年   16篇
  1981年   19篇
  1980年   20篇
  1979年   11篇
  1978年   5篇
  1977年   16篇
  1976年   11篇
  1975年   9篇
  1972年   2篇
排序方式: 共有1373条查询结果,搜索用时 15 毫秒
151.
152.
From the Finnish Twin Cohort (n = 27,100 pairs with known zygosity) all cases of diagnosed multiple sclerosis (MS) were reviewed and those with clinically verified MS were invited for further examinations at the Institute of Occupational Health, Helsinki, with their co-twins. Twenty one cases (19 pairs, of which 17 were discordant) fulfilled the strict criteria of MS. Detailed occupational history showed exposure to a mixture of solvents in six subjects, to lead in one, and to trichloroethylene in one. Of these seven, two monozygotic twins had MS whereas the other five cases were healthy co-twins. These results do not support a causal association between occupational exposure to chemicals and the aetiopathogenesis of MS.  相似文献   
153.
Orbital dermoids: features on CT   总被引:3,自引:0,他引:3  
The computed tomographic (CT) features of orbital dermoids were retrospectively reviewed in 17 patients; 15 of the lesions were proved histologically. On the basis of clinical and CT features, the tumors were classified as superficial or deep. All but one were extraconal in location. Seven lesions appeared cystic; only six showed typical fat density. The presence of a margin or rim, often partially calcified, was identified in ten lesions. Irregular scalloping of adjacent bone was a highly suggestive feature, occurring with 11 dermoids. Other bone changes, such as linear defects, thinning, or sclerosis, also occurred. Superficial dermoids showed less apparent bone changes. An extraconal orbital lesion associated with adjacent bone thinning or notching should raise the possibility of a dermoid, especially if a rim with calcification is seen. The appearance is pathognomonic if fat density is also present.  相似文献   
154.
Biliary lithotripsy: early observations in 106 patients. Work in progress   总被引:1,自引:0,他引:1  
Burhenne  HJ; Becker  CD; Malone  DE; Rawat  B; Fache  JS 《Radiology》1989,171(2):363-367
One hundred six patients underwent extracorporeal shock wave lithotripsy for cholelithiasis. Of these, 28 patients underwent cholangiographically guided lithotripsy for bile duct stones to assist nonoperative stone removal by endoscopic or radiologic intervention. Fragmentation occurred in 20 of 28 cases (71%) with an average of two lithotripsy sessions. Hemobilia was observed in four patients (14%) for a 24-hour period. Seventy-eight of the 106 were outpatients with symptomatic cholecystolithiasis with one to five calculi who underwent cholecystographic or ultrasound-(US) guided shock wave lithotripsy as definitive therapy. US examination showed stone fragmentation in 86% of cases. With an average of 1.6 treatment sessions and 4,750 shocks, fragments were 4 mm or smaller in 46% of patients. Nine percent of patients had no fragments after an average of 10 weeks, but long-term follow-up is not yet available. Two patients developed acute pancreatitis attributable to fragment passage and one patient acute cholecystitis, likely due to cystic duct obstruction by a fragment.  相似文献   
155.
Prevalence and Prognosis of Epilepsy in Patients with Multiple Sclerosis   总被引:9,自引:5,他引:4  
An analysis of 599 clinically definite multiple sclerosis (MS) patients including all known cases of the southern province of Finland in January 1, 1979 revealed epileptic seizures in 21 (3.5%) patients. On that date, 12 patients needed treatment (2.0%). The age-adjusted prevalence of active epilepsy was significantly higher than that in the general population. The percentage of partial seizures (67%) was significantly increased in proportion to a series of 100 adult epilepsy patients, with a comparable age distribution. In 10 patients (including three patients with symptomatic epilepsy), the attacks appeared before the MS symptoms. The mean follow-up after the first seizures was 19.3 years. In 10 patients, the seizures disappeared totally during the surveillance until September 1985. Our results show an increased comorbidity between MS and epilepsy. In most cases, however, the prognosis of epilepsy was good and there seemed not to be any clear correlation between the severity of MS and epilepsy.  相似文献   
156.
157.
158.
应用乙酰胆碱选择性微电极技术,观察到小剂量赛拉嗪(2.0和6.0mg·kg-1)可显著增加大鼠海马CA1区ACh的含量,而大剂量赛拉嗪(10.0mg·kg-1)及咪唑克生(0.6mg·kg-1)则作用相反。咪唑克生虽可明显拮抗赛拉嗪的作用,但海马CA1区ACh的含量仍显著低于正常水平。在去兰斑核的大鼠上,赛拉嗪(2.0和6.0mg·kg-1)及咪唑克生(0.6mg·kg-1)分别对海马CA1区ACh的含量具有减少和增加作用,且咪唑克生拮抗赛拉嗪的作用后,海马CA1区ACh的含量基本恢复至正常水平。结果提示,赛拉嗪对麻醉大鼠海马CA1区ACh含量呈双相性影响,咪唑可生虽能显著拮抗赛拉嗪的作用,但海马CA1区ACh的含量仍明显低于正常水平,可能分别与赛拉嗪和咪唑克生降低或提高中枢NE能系统的功能有关。  相似文献   
159.
160.
Temporal lobes: surface MR coil phased-array imaging   总被引:1,自引:0,他引:1  
Hayes  CE; Tsuruda  JS; Mathis  CM 《Radiology》1993,189(3):918
  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