全文获取类型
收费全文 | 2344301篇 |
免费 | 175815篇 |
国内免费 | 5852篇 |
专业分类
耳鼻咽喉 | 32274篇 |
儿科学 | 79140篇 |
妇产科学 | 64281篇 |
基础医学 | 339474篇 |
口腔科学 | 63737篇 |
临床医学 | 218283篇 |
内科学 | 456376篇 |
皮肤病学 | 48995篇 |
神经病学 | 190334篇 |
特种医学 | 88848篇 |
外国民族医学 | 914篇 |
外科学 | 340654篇 |
综合类 | 51680篇 |
现状与发展 | 2篇 |
一般理论 | 804篇 |
预防医学 | 191248篇 |
眼科学 | 52062篇 |
药学 | 173821篇 |
7篇 | |
中国医学 | 5077篇 |
肿瘤学 | 127957篇 |
出版年
2019年 | 18588篇 |
2018年 | 26181篇 |
2017年 | 19702篇 |
2016年 | 21561篇 |
2015年 | 24618篇 |
2014年 | 34052篇 |
2013年 | 52582篇 |
2012年 | 72147篇 |
2011年 | 76562篇 |
2010年 | 45093篇 |
2009年 | 42211篇 |
2008年 | 71336篇 |
2007年 | 75905篇 |
2006年 | 76184篇 |
2005年 | 73880篇 |
2004年 | 71238篇 |
2003年 | 68468篇 |
2002年 | 66628篇 |
2001年 | 108025篇 |
2000年 | 111789篇 |
1999年 | 94419篇 |
1998年 | 26688篇 |
1997年 | 24091篇 |
1996年 | 24197篇 |
1995年 | 23003篇 |
1994年 | 21709篇 |
1993年 | 20271篇 |
1992年 | 75622篇 |
1991年 | 74113篇 |
1990年 | 71873篇 |
1989年 | 68471篇 |
1988年 | 63338篇 |
1987年 | 62172篇 |
1986年 | 58615篇 |
1985年 | 56077篇 |
1984年 | 42331篇 |
1983年 | 35812篇 |
1982年 | 21181篇 |
1981年 | 19122篇 |
1979年 | 38121篇 |
1978年 | 26909篇 |
1977年 | 22430篇 |
1976年 | 21494篇 |
1975年 | 22646篇 |
1974年 | 27054篇 |
1973年 | 26324篇 |
1972年 | 24251篇 |
1971年 | 22324篇 |
1970年 | 20946篇 |
1969年 | 18994篇 |
排序方式: 共有10000条查询结果,搜索用时 8 毫秒
951.
P J Landrigan M G Cherniack F A Lewis L R Catlett R W Hornung 《Scandinavian journal of work, environment & health》1986,12(1):32-39
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
952.
Physiology and pathophysiology of skeletal muscle contractions 总被引:4,自引:0,他引:4
L. V. CHRISTENSEN 《Journal of oral rehabilitation》1986,13(5):451-461
An overview is presented of the physiology and pathophysiology of dynamic skeletal muscle contractions in the intact living organism. Dynamic muscle activities are divided into concentric contractions with shortening of muscle fibres and the production of positive work, and eccentric contractions with lengthening of muscle fibres and the production of negative work. In positive work, muscle tension overcomes external forces. In negative work, external forces overcome muscle tension. The latter phenomenon, with relatively few active motor units, explains the injuries induced by eccentric contractions. Both the contractile and non-contractile elements are involved in the muscle injuries and, clinically, they are referred to as myofibrositis. 相似文献
953.
L Paris M Giardina R Pacifici S Pichini P Zuccaro G Sideri 《The Italian Journal of Neurological Sciences》1991,12(5):447-451
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
954.
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
955.
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
956.
Child psychopathology and environmental influences: discrete life events versus ongoing adversity 总被引:1,自引:0,他引:1
P S Jensen J Richters T Ussery L Bloedau H Davis 《Journal of the American Academy of Child and Adolescent Psychiatry》1991,30(2):303-309
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
957.
Current transition assessment practices. 总被引:1,自引:0,他引:1
Although researchers have called for a movement away from prediction-related assessments to those which identify specific skill deficits, the extent to which professionals responsible for vocational assessment have shifted their focus is uncertain. The purpose of this investigation was to assess the frequency with which specified prediction-related and skill deficit-related vocational assessment procedures were administered by a sample of secondary-level teachers and employment training specialists. Additionally, the frequency with which these professionals used assessment data to aid in decision making was determined. The results revealed that teachers and employment training personnel used a variety of assessment procedures to make transition decisions. The implications of these findings are discussed. 相似文献
958.
We report a case of mild visuo-spatial neglect consequent upon right-hemisphere stroke. At the time of testing, the patient had a complete left visual field deficit but only a very slight left hemiparesis. Under conventional testing conditions, line bisection performed with the right hand showed more severe left neglect than when performed with the left hand. This pattern of performance could, however, be modified, both quantitatively and qualitatively, by changing the starting position of the patient's hand when bisecting horizontal lines. The results suggest that spatio-motor cueing has a more profound effect upon task performance than does differential hemispheric activation per se. We also provide a demonstration that, in a normal subject, the starting position of the hand is likewise a crucial determinant of task performance. In this case, however, there is also an interaction between the hand (and hence hemisphere) deployed and the position of that hand in space. 相似文献
959.
960.
R J Gatchel T G Mayer P Capra J Barnett P Diamond 《Archives of physical medicine and rehabilitation》1986,67(12):878-882
The present study evaluated the use of psychologic measures, in particular, the relatively new Million Behavioral Health Inventory (MBHI), in predicting change in physical function of chronic low back pain patients undergoing a functional restoration program. The first 134 consecutive patients completing this program were assessed. Results demonstrated that various clinical scales of the MBHI were predictive of improvement in physical function. In addition, various scales enabled discrimination between patients who completed the program and those who prematurely dropped out. Although this inventory shows promise in helping to predict response to treatment, no single psychologic test can reliably be used as the sole predictor in clinical cases. 相似文献