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   3160889篇
  免费   248477篇
  国内免费   5662篇
耳鼻咽喉   45824篇
儿科学   101641篇
妇产科学   85279篇
基础医学   446465篇
口腔科学   90039篇
临床医学   287388篇
内科学   615347篇
皮肤病学   65738篇
神经病学   261177篇
特种医学   125886篇
外国民族医学   1301篇
外科学   477492篇
综合类   74312篇
现状与发展   2篇
一般理论   1252篇
预防医学   253274篇
眼科学   74002篇
药学   236473篇
  6篇
中国医学   5954篇
肿瘤学   166176篇
  2018年   32638篇
  2017年   24995篇
  2016年   27577篇
  2015年   31157篇
  2014年   44509篇
  2013年   67917篇
  2012年   92227篇
  2011年   97549篇
  2010年   57649篇
  2009年   55051篇
  2008年   92664篇
  2007年   98780篇
  2006年   99381篇
  2005年   96745篇
  2004年   93653篇
  2003年   90564篇
  2002年   89009篇
  2001年   146106篇
  2000年   151299篇
  1999年   128282篇
  1998年   37193篇
  1997年   33692篇
  1996年   33564篇
  1995年   32348篇
  1994年   30331篇
  1993年   28342篇
  1992年   103195篇
  1991年   100275篇
  1990年   96873篇
  1989年   93275篇
  1988年   86370篇
  1987年   85127篇
  1986年   80333篇
  1985年   76848篇
  1984年   58275篇
  1983年   49597篇
  1982年   29851篇
  1981年   26795篇
  1979年   54263篇
  1978年   38025篇
  1977年   32176篇
  1976年   30243篇
  1975年   32129篇
  1974年   39176篇
  1973年   37350篇
  1972年   34816篇
  1971年   32033篇
  1970年   30330篇
  1969年   28059篇
  1968年   25558篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
    
Zusammenfassung 103 Patienten wurden wegen akuter spontaner oder nach Trauma persistierender Scrotalschmerzen behandelt. 62mal wurde diagnostisch freigelegt. Die intraoperativen Befunde (32 Torsionen, 12 stielgedrehte Hydatiden, 3 Hodennekrosen, 3 Hodenrupturen, 7 komprimierende Haematome, 5 Epididymitiden) bestätigten unsere Indikationsstellung zur chirurgischen Exploration: Plötzlicher Spontanschmerz, vor allem beim jugendlichen Patienten, anhaltender Schmerz nach Hodenprellung und alle Zweifelsfälle! Ohne Alternative spart der komplikationslose und schnelle diagnostisch-chirurgische Eingriff Zeit für das gefährdete Organ bei simultaner Therapiemöglichkeit.  相似文献   
992.
The effects of labeling a person as hypertensive have important implications for hypertension screening. The Hypertension Detection and Follow-up Program (HDFP) provides an opportunity to examine the effects of labeling, treatment, and study assignment on a large group of hypertensives (n = 10,070). Their answers to questions regarding perceived health and general well-being asked at baseline and again one year later were analyzed. There was no significant change in the perceived health status of persons who were unaware of their hypertension at baseline and remained untreated at one year (labeling alone). The effect of labeling plus treatment was associated with a significant decrease in perceived health. The effect of antihypertensive drug therapy on perceived health status was examined in persons who were aware of their hypertension but not on treatment at baseline, and on treatment at one year. The stepped care group (SC) had a significant improvement in their perceived health and a significant decrease in the amount of time spent worrying about their health. The referred care group (RC) had no change. Program assignment effects were studied in individuals aware of their hypertension and on treatment both at baseline and one year later. Both the SC and RC groups had a significant improvement in their perceptions of their health status. The SC group had a significant decrease in time spent worrying about their health, while the RC group showed no change. These reassuring results fail to support the suggestion that labeling persons as hypertensive is necessarily followed by negative psychological consequences.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   
993.
In medical studies with censored data Kaplan and Meier's product limit estimator has frequent use as the estimate of the survival function. Simultaneous confidence intervals for the survival function at various time points constitute a useful addition to the analysis. This study compares several such methods. We consider in a simulation investigation two whole curve confidence bands and four methods based on the Bonferroni inequality. The results show that three Bonferroni-type methods are essentially equivalent, all being better than the other methods when the number of time points is small (3 or 5).  相似文献   
994.
Button wiring has been used as an alternative to eyelet wiring in the Department of Oral and Dental Surgery of Birmingham General Hospital since 1977. This clinical update reviews 65 patients with mandibular fractures in which button wires were utilised in their treatment.  相似文献   
995.
An industrial hygiene and medical survey was conducted in an iron foundry to study the occurrence of silicosis. Breathing zone exposures to respirable crystalline silica had been very high in 1977 [1 045 micrograms/m3 (geometric mean) for coremakers and 198 micrograms/m3 for fettlers]; exposures in 1980 and 1982 were substantially lower. A radiographic evaluation of 188 workers revealed silicosis in 18 (9.6%). Eight had category 1 profusion of small rounded pulmonary lesions (by the 1980 classification of the International Labour Office); two had category 2; and eight had category 3. Two had progressive massive fibrosis. Four workers without silicosis in 1977 had developed lesions by 1980. The prevalence increased from 1.5% among workers employed less than 20 years to 53% among longer term workers. No association was found between the prevalence of silicosis and cigarette smoking. Chronic cough was more common in workers with heavy current dust exposure than in those with light exposure, more common in smokers than in nonsmokers, and more common in silicotics than in nonsilicotics. A multiplicative interaction existed between dust exposure and smoking in the etiology of cough. Silicosis continues to exist in American foundries. Cigarette smoking does not contribute to the causation of silicosis, but it aggravates the attendant respiratory symptoms.  相似文献   
996.
We compared two groups of patients with idiopathic epilepsy, 41 patients whose seizure frequency was not controlled by adequate therapy and 39 patients in good seizure control, in respect of hematology, kidney and liver function tests, serum IgG, IgA and IgM concentrations and drug concentrations. The only difference that emerged were in the serum immunoglobulins, which were raised in the drug refractory group, significantly (p less than 0.01) so in the case of IgG. Failure of seizure control did not depend on inadequacy of drug dose or of blood concentration. Although the serum Ig changes do not warrant the assumption of an immunological origin for drug resistance, they do suggest a useful research line.  相似文献   
997.
This paper critically examines the pharmacological provocation and treatment of panic disorder. An analysis of research findings on how panic attacks are induced indicates that there are psychological and non specific factors that may mediate biochemical etiological models, and these individual differences need to be investigated further. This has important implications for the psychopharmacological management of panic. A review of studies on treating panic disorder with imipramine and alprazolam emphasizes the importance of several non specific factors that include the role of self-directed in vivo exposure and changes in dysphoria and self-efficacy (subjective beliefs regarding personal competency) in predicting outcome. It is recommended that any treatment of panic-related disorders include self-directed, in vivo exposure.  相似文献   
998.
In newly diagnosed adult patients with epilepsy followed prospectively on monotherapy, carbamazepine and phenytoin were associated with a fall in plasma uric acid, but sodium valproate and phenobarbitone were associated with a rise in plasma uric acid. The mechanisms and significance of these findings are discussed.  相似文献   
999.
Patterns of exposure to distinct types of life stressors were compared between 134 children attending a military child psychiatric clinic and a matched military community control sample. Compared with the community sample, clinic-referred children had experienced significantly higher levels of normative stressful events as well as events confounded with their own adjustment and events related to parental psychosocial functioning. Differences in levels of normative stressful events were no longer significant, however, when controlling for events related to parental functioning. Ratings of stressful events during the past year significantly underestimated the lifetime stress exposure differences between clinic and community control children. Although normative stressful events, parent-related events, and parent symptomatology ratings were significantly related to child behavior problem ratings, normative stressful events did not contribute to predictions of child behavior problems beyond the variance attributable to parent-related events and parent symptomatology. Implications of these findings for life stress and child maladjustment research are discussed.  相似文献   
1000.
Electrocardiograms were evaluated in 39 children and adolescents before and after the clinical use of imipramine and desipramine. The average increase in PR interval was 0.01 seconds. The PR interval increased by 0.02 seconds in 11 subjects, and a new first-degree atrioventricular block developed in two subjects. These changes were not related to the choice between imipramine and desipramine, the dose, or the method of administration. An increase in PR interval by 0.02 seconds or more did correlate with having an abnormality disclosed on a pretreatment electrocardiogram. The average increase in PR interval was 0.007 seconds for subjects with normal baseline electrocardiograms and 0.019 seconds for subjects with conduction and nonconduction abnormalities disclosed in baseline tracings. None of the electrocardiogram changes resulted in adverse clinical consequences.  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