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   11453篇
  免费   701篇
  国内免费   22篇
耳鼻咽喉   141篇
儿科学   515篇
妇产科学   125篇
基础医学   1473篇
口腔科学   390篇
临床医学   846篇
内科学   2466篇
皮肤病学   172篇
神经病学   1138篇
特种医学   294篇
外科学   1612篇
综合类   266篇
一般理论   2篇
预防医学   634篇
眼科学   210篇
药学   871篇
中国医学   70篇
肿瘤学   951篇
  2023年   72篇
  2022年   160篇
  2021年   373篇
  2020年   182篇
  2019年   274篇
  2018年   311篇
  2017年   217篇
  2016年   236篇
  2015年   267篇
  2014年   403篇
  2013年   548篇
  2012年   849篇
  2011年   811篇
  2010年   446篇
  2009年   401篇
  2008年   613篇
  2007年   609篇
  2006年   578篇
  2005年   540篇
  2004年   483篇
  2003年   469篇
  2002年   394篇
  2001年   297篇
  2000年   294篇
  1999年   260篇
  1998年   114篇
  1997年   97篇
  1996年   68篇
  1995年   70篇
  1994年   58篇
  1993年   65篇
  1992年   165篇
  1991年   154篇
  1990年   129篇
  1989年   127篇
  1988年   107篇
  1987年   113篇
  1986年   89篇
  1985年   90篇
  1984年   77篇
  1983年   70篇
  1982年   33篇
  1981年   35篇
  1980年   24篇
  1979年   50篇
  1978年   37篇
  1975年   27篇
  1974年   30篇
  1973年   29篇
  1970年   26篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
H T Nair  G Little 《Journal of postgraduate medicine》1991,37(4):232B, 233-232B, 234
A case of bladder tumour arising as a metastasis of renal carcinoma and presenting as obstruction to urinary outflow is described. The possible mechanism of spread to bladder is also suggested.  相似文献   
32.
33.
The modulation of drug metabolising enzymes by Masheri extract (ME) and Benzo(a)Pyrene [B(a)P] was studied in male Sprague Dawley rats fed different dietary protein levels. Two groups of 21 days old male Sprague Dawley rats were put on a high protein diet (SHP) with 20% Casein, and a low protein diet (SLP) with 3% Casein semisynthetic based diets for 12 weeks. The SLP fed animals showed lower basal levels of the Phase I activating enzymes viz. Cytochrome P450, Benzo(a)Pyrene hydroxylase, Benzphetamine demethylase and Phase II glutathione detoxification system viz. Glutathione (GSH) and Glutathione-S-transferase. ME and B(a)P treatment significantly depleted the glutathione detoxification system in the SLP group whereas an opposite effect was observed in the SHP group. Interstingly, ME and B(a)P treated rats in the SLP group showed a higher percent increase in the hepatic and pulmonary Phase I enzyme activities than those observed in the treated ME/B(a)P treated SHP rats. Furthermore, both ME and B(a)P significantly decreased the hepatic pool of vitamin A while a concomittant increase in that of vitamin C was observed.  相似文献   
34.
A magnetic resonance imaging study of putamen nuclei in major depression.   总被引:7,自引:0,他引:7  
The basal ganglia are recognized as putative mediators of certain cognitive and behavioral symptoms of major depression. Moreover, patients with basal ganglia lesions have repeatedly exhibited significant affective symptomatology, including apathy, depressive mood, and psychosis. Using high resolution, axial T2 intermediate magnetic resonance images, and a systematic sampling stereologic method, we assessed putamen nuclei volumes in 41 patients with major depression (DSM-III) and 44 healthy volunteer controls of similar age. Depressed patients had significantly smaller putamen nuclei compared with controls. Age was negatively correlated with putamen size in both groups. These results are the first demonstration of diminished putamen volumes in depression and further support a role for basal ganglia structures in the etiopathogenesis of depression.  相似文献   
35.
Seventy-nine patients with moderate to severe left ventricular dysfunction who underwent aortocoronary bypass grafting between 1971 and 1977 had follow-up heart catheterization at a mean interval of 3 years. Thirty-three patients (42%) had angiographic improvement in left ventricular function at follow-up and 18 (25%) had a decrease in left ventricular end-diastolic pressure. Fifty-eight patients (73%) had improvement in angina of at least one New York Heart Association class at follow-up. There was no correlation between late improvement in left ventricular function and improvement in angina. Improvement in left ventricular function did not correlate with preoperative indices of severity of coronary disease or with indices of completeness of surgical repair.  相似文献   
36.
The quality of medical education during internship is a cause for concern. This paper describes a structured educational programme for interns that was based around learning modules, clinical attachments and bedside teaching. The programme was incorporated into the term rotation of interns within an Area Health Service, and evaluated. Learning modules were timetabled by a Programme Coordinator and interns were reminded to attend. Clinical attachments were organized by the interns from a list of willing supervisors. Attendance at timetabled learning modules averaged 67%, which was greater than the 27% attendance at clinical attachments. Both sessions received high ratings for quality and clinical relevance. This structured education programme was based upon adult learning methods and was both feasible and well received by interns. Intern training programmes need to be programmed into the working week to ensure attendance, and modified following evaluation by interns. Such programmes should be considered by all hospitals to which interns are allocated.  相似文献   
37.
38.
39.
OBJECTIVE: To investigate the cause of the transient weakness that occurs in recessive myotonia congenita (RMC) following sustained muscle contraction. METHODS: Nerve excitability studies were performed on a 35-year-old male with RMC due to a novel 696+1G>A CLCN1 mutation. The median nerve was stimulated at the wrist and compound muscle action potentials (CMAPs) were recorded from abductor pollicis brevis (APB). Stimulus-response behaviour using two stimulus durations, threshold electrotonus to 100-ms polarizing currents, a current threshold relationship and the recovery of excitability following supramaximal stimulation were recorded at rest. Excitability parameters were also recorded before and after maximal voluntary contraction (MVC) of APB against resistance for 60s. Results were compared to data obtained from 12 normal controls. RESULTS: Baseline axonal excitability parameters were all normal, indicating that axonal function was normal at the point of stimulation. Following one minute of MVC, excitability parameters demonstrated a significant increase in threshold when compared to controls (RMC 54.9%; controls 15.5+/-3.1%). In the RMC patient, this increase in threshold was associated with a 39% reduction in the amplitude of the maximal CMAP, which remained unaffected in controls. CONCLUSIONS: The reduction in maximal CMAP is likely to represent muscle activation failure due to depolarization block, with the increase in threshold possibly reflecting a compensatory attempt by motor axons to overcome prolonged contraction-induced changes in the muscle membrane. SIGNIFICANCE: The prolonged recovery of excitability following sustained muscle contraction is likely to be a contributing factor to symptoms of weakness and fatigue experienced by RMC patients.  相似文献   
40.
Extensive intraductal component (EIC) has been reported to have a prominent role in local recurrence after treatment of early-stage breast cancer with lumpectomy and irradiation. Pathologic specimens from 250 breasts (245 patients) treated between June 1982 and June 1990 with lumpectomy, immediate (boost) interstitial iridium-192 to 15-20 Gy, and external-beam irradiation to the entire breast to 45-50 Gy were reviewed. EIC was present in 61 breasts. At a median follow-up period of 58 months (range, 14-110 months), there were 10 recurrences in the 250 treated breasts. Of these 10, three were in patients from the group with EIC. The 10-year actuarial recurrence rates in breasts with and without EIC were 9.1% and 5.2%, respectively. The difference between the two rates was not significant. If an immediate boost with interstitial iridium is used in therapy, the influence of EIC on local failure is insignificant.  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