全文获取类型
收费全文 | 50447篇 |
免费 | 2707篇 |
国内免费 | 189篇 |
专业分类
耳鼻咽喉 | 648篇 |
儿科学 | 1240篇 |
妇产科学 | 1150篇 |
基础医学 | 6885篇 |
口腔科学 | 3020篇 |
临床医学 | 4177篇 |
内科学 | 11219篇 |
皮肤病学 | 1322篇 |
神经病学 | 4612篇 |
特种医学 | 1149篇 |
外国民族医学 | 1篇 |
外科学 | 5605篇 |
综合类 | 295篇 |
一般理论 | 13篇 |
预防医学 | 4825篇 |
眼科学 | 1000篇 |
药学 | 3691篇 |
中国医学 | 327篇 |
肿瘤学 | 2164篇 |
出版年
2023年 | 426篇 |
2022年 | 902篇 |
2021年 | 1720篇 |
2020年 | 973篇 |
2019年 | 1522篇 |
2018年 | 1828篇 |
2017年 | 1225篇 |
2016年 | 1331篇 |
2015年 | 1532篇 |
2014年 | 2023篇 |
2013年 | 2613篇 |
2012年 | 3949篇 |
2011年 | 4200篇 |
2010年 | 2190篇 |
2009年 | 1777篇 |
2008年 | 3125篇 |
2007年 | 3096篇 |
2006年 | 2800篇 |
2005年 | 2590篇 |
2004年 | 2477篇 |
2003年 | 2081篇 |
2002年 | 1939篇 |
2001年 | 962篇 |
2000年 | 958篇 |
1999年 | 763篇 |
1998年 | 303篇 |
1997年 | 213篇 |
1996年 | 219篇 |
1995年 | 160篇 |
1994年 | 146篇 |
1993年 | 115篇 |
1992年 | 295篇 |
1991年 | 293篇 |
1990年 | 267篇 |
1989年 | 207篇 |
1988年 | 203篇 |
1987年 | 190篇 |
1986年 | 167篇 |
1985年 | 148篇 |
1984年 | 146篇 |
1983年 | 119篇 |
1982年 | 71篇 |
1981年 | 85篇 |
1980年 | 70篇 |
1979年 | 93篇 |
1978年 | 71篇 |
1975年 | 56篇 |
1971年 | 60篇 |
1969年 | 49篇 |
1967年 | 69篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
Semi-structured interviews were conducted with a cohort of 22 test applicants who requested Huntington's disease (HD) predictive testing in South Wales, and a random sample of 32 non-requesters, drawn from the South Wales HD register. Apart from identifying differences between the groups, the study afforded the opportunity to listen, at length, to at-risk individuals' accounts of living at risk and their thoughts about predictive testing and genetic services. Emergent themes included difficulties in family communication and the uncertainties inherent in being at risk and undergoing testing. Important factors in decision making about testing were: moral imperatives to clarify one's genetic status; views about the controllability of the future; family attitudes and norms; and the impact of a test result on family members. At-risk individuals' perceptions of the genetics service were that contact with the service would result in pressure to be tested and a need for test applicants to present a favourable view of coping capacities to secure testing. In addition, there was an expectation of ongoing contact with HD families at the initiative of the service providers. Implications of the findings for the way in which predictive testing services are structured and introduced to the at-risk population are discussed. 相似文献
32.
C. A. Mangone E. M. Castaño E. Levy G. Abiusi T. Wisniewski M. R. Marques E. Faccio P. B. Gorelick B. Frangione and R. E. P. Sica 《Acta neurologica Scandinavica》1995,91(1):6-13
We report the clinical, SPET, immunohistochemical and DNA features of an early-onset familial Alzheimer's disease (FAD) in an Argentine pedigree of South American indian ethnic background. Pedigree spans 5 generations comprising more than 110 biological relatives. Clinical data supported the diagnosis of early onset FAD (mean age at onset 38.9 years) in 10 family members, including 3 with pathological confirmation (mean age at death 48.5). The pattern of transmission suggested autosomal dominant inheritance. Prominent features were mood changes, early language impairment, myoclonus, seizures and cerebellar signs. SPET displayed bilateral frontal, temporo-parietal and cerebellar hypoperfusion in early stages and in an asymptomatic member at risk, suggesting that SPET may have predictive value in this family. Immunohistochemistry showed β amyloid deposits within neuritic plaques and vessel walls and no anti-PrP immunoreactivity. DNA analysis showed no abnormalities in the β amyloid precursor protein gene. The identification of additional genetic defects in well characterized independent FAD pedigrees will contribute to the understanding of the pathogenesis of Alzheimer's disease. 相似文献
33.
J. Wayne Streilein Scott Cousins Jo S. P. Williamson 《International ophthalmology》1990,14(5-6):317-325
Regulation of T cell-dependent immune responses is mediated in part by bone marrow-derived antigen presenting cells (APC) that (a) process and present antigens which engage the T cell receptor and (b) secrete cytokines that influence the threshold of T cell activation. The anterior chamber of the eye is lined by the corneal endothelium (which rests on a stroma and epithelium that is devoid of class II MHC + APC) and iris/ciliary body (which contain significant numbers of bone marrow-derived cells, one third of which are class II MHC +). When tested in vitro, these potential APCs fail to present antigens in a form that activates T cells. Moreover, iris/ciliary body cells actually suppress activation of T cells exposed to antigens on conventional APC. In addition, aqueous humor under normal circumstances contains factors (one of which is TGFB) that are potent inhibitors of antigen-driven T cell activation, but spare other aspects of T cell function. Evidence suggests that the bone marrow-derived cells in iris/ciliary body are the source of this factor. Thus, the anterior chamber contains powerful forces that can prevent induction and can suppress expression of T cell mediated immunity. It is proposed that these forces are responsible for immunologic privilege and anterior chamber associated immune deviation, and for suppressing pathologic proliferation and inflammation in the anterior segment of the eye. 相似文献
34.
35.
36.
37.
38.
39.
Jong-Moon Lee Kun-Woo Park Woo-Keun Seo Moon Ho Park Changsu Han Inho Jo Sangmee Ahn Jo 《Movement disorders》2007,22(16):2446-2449
There have been a few studies and inconsistent results regarding the coincidence of Parkinson's disease (PD) and atherosclerotic diseases, such as cerebrovascular disease. Carotid intima-media thickness (IMT) is a known marker for subclinical atherosclerosis. The aim of this study was to investigate the carotid IMT between PD patients and controls. We studied 43 patients with PD and 86 matched controls. The carotid IMT in PD patients was significantly smaller than in controls (0.796 +/- 0.179 mm vs. 0.913 +/- 0.237 mm, P < 0.05). In multivariate analysis, the carotid IMT was inversely associated with the duration of levodopa medication and the severity of PD. These results suggest that PD patients have a lower risk of atherosclerosis. 相似文献
40.
Dong Hwee Kim Yoon Kyoo Kang Miriam Hwang Ho Sung Jo Ki Hoon Kim 《Clinical neurophysiology》2004,115(5):1021-1026
OBJECTIVE: To evaluate the usefulness of the TenElectrodes, a new stimulator for inching test, in the diagnosis and localization of ulnar neuropathy at the elbow (UNE). METHODS: Sixty-two ulnar nerves in 40 control subjects and 24 ulnar nerves in 23 patients with typical symptoms and signs of UNE were studied. The inching test of ulnar motor nerve using TenElectrodes was done along 8 cm across the elbow in the extended position. RESULTS: In the inching test of the control group, the mean segmental latency difference was 0.19+/-0.08 ms. Maximal latency difference over a 1 cm segment did not exceed 0.40 ms in any of the controls but exceeded 0.5 ms or more in all clinical UNE patients. In all UNE patients, the lesion sites were identified by the inching test using TenElectrodes: the retroepicondylar groove (54.2%), the humeroulnar arcade (29.2%), and dual compression (16.6%). CONCLUSIONS: TenElectrodes is a useful stimulator for the inching test in the diagnosis of UNE. The precise localization of compression was possible in all patients with UNE and the most common site was the retroepicondylar groove. 相似文献