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   3243071篇
  免费   236672篇
  国内免费   5166篇
耳鼻咽喉   45895篇
儿科学   107123篇
妇产科学   87380篇
基础医学   469660篇
口腔科学   88649篇
临床医学   292401篇
内科学   628072篇
皮肤病学   70838篇
神经病学   257224篇
特种医学   123268篇
外国民族医学   1096篇
外科学   490951篇
综合类   68664篇
现状与发展   13篇
一般理论   1268篇
预防医学   255067篇
眼科学   75933篇
药学   241479篇
  14篇
中国医学   6245篇
肿瘤学   173669篇
  2019年   26365篇
  2018年   36588篇
  2017年   27485篇
  2016年   30665篇
  2015年   34653篇
  2014年   48915篇
  2013年   74173篇
  2012年   102053篇
  2011年   108618篇
  2010年   64692篇
  2009年   61114篇
  2008年   102135篇
  2007年   109219篇
  2006年   109926篇
  2005年   106756篇
  2004年   102878篇
  2003年   99172篇
  2002年   96512篇
  2001年   145524篇
  2000年   149592篇
  1999年   126889篇
  1998年   37542篇
  1997年   32953篇
  1996年   33333篇
  1995年   31649篇
  1994年   29340篇
  1993年   27478篇
  1992年   99051篇
  1991年   97040篇
  1990年   94433篇
  1989年   90622篇
  1988年   83490篇
  1987年   82249篇
  1986年   76926篇
  1985年   74102篇
  1984年   55577篇
  1983年   47283篇
  1982年   28464篇
  1981年   25739篇
  1979年   50798篇
  1978年   36168篇
  1977年   30403篇
  1976年   28818篇
  1975年   31072篇
  1974年   36801篇
  1973年   35231篇
  1972年   32773篇
  1971年   30685篇
  1970年   28602篇
  1969年   26869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.
996.
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   
997.
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   
998.
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   
999.
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   
1000.
We experienced one necropsy case of brainstem encephalitis of Iizuka type (BSE) and one necropsy case of the brain-stem syndrome (BSS) of typical neuro-Beh?et's disease, and compared them clinically and neuropathologically. Clinically both of these cases showed chronic progressive mental disturbance, pseudobulbar paresis, spastic tetraparesis, cerebrospinal fluid pleocytosis, increased protein, and brainstem atrophy observed by X-CT. Neuropathologically, irregular, boundary-indistinct demyelinating lesions and obsolete softening lesions were sporadically found, associated with perivascular lymphocytic infiltration and gliosis centering on the brainstem. In this way, both cases were similar in many points except for the presence or absence of cutaneo-muco-ocular signs specific for Beh?et's disease. Also BSE and BSS reports in the literature showed that both diseases were similar not only in clinical findings consisting of mental disturbance and brainstem signs but also in neuropathological findings with similar topographical distribution of the same histopathological changes, including the variations and diversity of these characteristics. Especially of much interest is their similarity in characteristic mental disturbance. In discriminating BSE from multiple sclerosis and other diseases with exclusive involvement of the brainstem, it is important to understand their clinical characteristics. The characteristic mental disturbance includes damage to memory and sentiment, a change in personality, and lowering in spontaneity, but calculation ability and orientation are comparatively preserved. Of course the similarity in clinical and neuropathological findings does not necessarily mean the identical etiopathogenesis. However, it is possible to consider that neuro-Beh?et's disease (syndrome) may form a wide spectrum with BSE and typical neuro-Beh?et's disease at the both ends, regarding the time and spatial diversity of the appearance of cutaneo-muco-ocular signs.  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