全文获取类型
收费全文 | 2044740篇 |
免费 | 144344篇 |
国内免费 | 4217篇 |
专业分类
耳鼻咽喉 | 30171篇 |
儿科学 | 59768篇 |
妇产科学 | 56461篇 |
基础医学 | 288823篇 |
口腔科学 | 62319篇 |
临床医学 | 177395篇 |
内科学 | 395298篇 |
皮肤病学 | 44982篇 |
神经病学 | 161033篇 |
特种医学 | 80809篇 |
外国民族医学 | 501篇 |
外科学 | 319418篇 |
综合类 | 47720篇 |
现状与发展 | 7篇 |
一般理论 | 644篇 |
预防医学 | 143288篇 |
眼科学 | 48725篇 |
药学 | 155751篇 |
7篇 | |
中国医学 | 5197篇 |
肿瘤学 | 114984篇 |
出版年
2018年 | 18842篇 |
2016年 | 16785篇 |
2015年 | 18841篇 |
2014年 | 26174篇 |
2013年 | 39408篇 |
2012年 | 52188篇 |
2011年 | 55432篇 |
2010年 | 32937篇 |
2009年 | 31694篇 |
2008年 | 53215篇 |
2007年 | 56889篇 |
2006年 | 57868篇 |
2005年 | 56166篇 |
2004年 | 55341篇 |
2003年 | 53379篇 |
2002年 | 52386篇 |
2001年 | 101512篇 |
2000年 | 104328篇 |
1999年 | 88112篇 |
1998年 | 23188篇 |
1997年 | 20846篇 |
1996年 | 20233篇 |
1995年 | 19078篇 |
1994年 | 17788篇 |
1993年 | 16637篇 |
1992年 | 67855篇 |
1991年 | 65587篇 |
1990年 | 64194篇 |
1989年 | 62408篇 |
1988年 | 57813篇 |
1987年 | 56716篇 |
1986年 | 53773篇 |
1985年 | 51436篇 |
1984年 | 37921篇 |
1983年 | 32392篇 |
1982年 | 18585篇 |
1981年 | 16818篇 |
1979年 | 35947篇 |
1978年 | 25304篇 |
1977年 | 21998篇 |
1976年 | 19675篇 |
1975年 | 22167篇 |
1974年 | 26441篇 |
1973年 | 25544篇 |
1972年 | 24296篇 |
1971年 | 22772篇 |
1970年 | 21679篇 |
1969年 | 20634篇 |
1968年 | 19225篇 |
1967年 | 17280篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
L C Harlan B F Polk S Cooper T P Blaszkowski J Ignatius-Smith M Stromer H Mull 《American journal of preventive medicine》1986,2(5):256-261
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
992.
M M O'Kane P A King H D Edmondson 《International journal of oral and maxillofacial surgery》1986,15(4):422-424
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
993.
994.
995.
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
996.
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
997.
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
998.
Current status of research activity in American child and adolescent psychiatry: Part I 总被引:1,自引:0,他引:1
T Shapiro D Mrazek H A Pincus 《Journal of the American Academy of Child and Adolescent Psychiatry》1991,30(3):443-448
A survey of research activity of American academic child psychiatrists was completed in February, 1989. The survey demonstrated an increase in research activity since the 1983 report in the Current Status of Child Psychiatry. A definition of a researcher was derived from a study of internists and general psychiatrists and applied to the 488 respondents (78.5% of sample), and it was found that males outnumber females and that researchers contribute significantly more to the literature and education than nonresearchers. Early research exposure and mentoring are important influences on a research career. Recommendations by researchers for future training of researchers are presented. Periodic surveys are encouraged. 相似文献
999.
T Nakanishi 《Clinical neurology》1991,31(12):1326-1329
Recently, many attempts have been made to measure the difference in velocity between the fastest and slowest fibers in a nerve trunk or to estimate the nerve fiber conduction velocity distribution in a nerve bundle using several different methods, such as collision technique (Hopf 1963) and computer analysis of the compound action potentials (Cummins et al. 1979; Barker et al. 1979). For the computer analysis, however, some assumptions in regard to the quantitative relationship among conduction velocity, single fiber action potential and fiber diameter are necessary, and there has been little agreement about them. There is also a problem about the relationship between conduction velocity and refractory period in Hopf's technique. Using a collision technique with a method of 3-point stimulation, Gilliat et al. (1976) now suggested that surface recording was unsatisfactory for measuring the velocity of the slow-conducting nerve fibers. With this method, however, we had a preliminary experiment to analyze conduction velocities of so-called A fibers in the bullfrog's sciatic-peroneal nerve using fluid electrode, and they were divided into 3 groups (Nakanishi et al. 1986). These findings were in good agreement with those obtained by Erlanger and Gasser (1937) using monophasic recording. Therefore, clinical measurement of the nerve conduction velocities with a method of this collision technique was performed using surface recording. 相似文献
1000.
H M Meinck 《Der Nervenarzt》1991,62(12):762-765
The discovery of autoimmune processes in the stiff-man syndrome (SMS) not only raises questions concerning the syndrome itself, but may also lead to new insights into pathogenetic principles of neurological disorders. Autoantibodies against GAD, the GABA synthesising enzyme, may become a helpful (though not specific) diagnostic tool, and furthermore may serve as a plausible explanation for both the symptoms of the syndrome and the delayed development of type I diabetes mellitus. However, it remains unexplained why autoimmunity against such widespread inhibitory transmitter systems should induce a syndrome which by definition is confined to only a few symptoms, and for which the majority of neurological signs are regarded as exclusion criteria. It is therefore hypothesised that SMS is part of a broad spectrum of encephalomyelopathies with autoimmunity against GABAergic neurones in common, but with a heterotopic manifestation. Progressive encephalomyelitis with rigidity may be an extreme variant within this spectrum. 相似文献