全文获取类型
收费全文 | 260893篇 |
免费 | 19063篇 |
国内免费 | 1132篇 |
专业分类
耳鼻咽喉 | 2906篇 |
儿科学 | 6813篇 |
妇产科学 | 4912篇 |
基础医学 | 34340篇 |
口腔科学 | 4699篇 |
临床医学 | 26549篇 |
内科学 | 55188篇 |
皮肤病学 | 3552篇 |
神经病学 | 25347篇 |
特种医学 | 8596篇 |
外国民族医学 | 11篇 |
外科学 | 39546篇 |
综合类 | 3684篇 |
一般理论 | 327篇 |
预防医学 | 22320篇 |
眼科学 | 6760篇 |
药学 | 17672篇 |
6篇 | |
中国医学 | 368篇 |
肿瘤学 | 17492篇 |
出版年
2023年 | 1376篇 |
2022年 | 2441篇 |
2021年 | 5540篇 |
2020年 | 3345篇 |
2019年 | 5436篇 |
2018年 | 6108篇 |
2017年 | 4593篇 |
2016年 | 5061篇 |
2015年 | 5953篇 |
2014年 | 8791篇 |
2013年 | 12050篇 |
2012年 | 18378篇 |
2011年 | 19266篇 |
2010年 | 10800篇 |
2009年 | 9600篇 |
2008年 | 16934篇 |
2007年 | 17814篇 |
2006年 | 17673篇 |
2005年 | 17666篇 |
2004年 | 16543篇 |
2003年 | 15382篇 |
2002年 | 14364篇 |
2001年 | 2452篇 |
2000年 | 1953篇 |
1999年 | 2608篇 |
1998年 | 3173篇 |
1997年 | 2668篇 |
1996年 | 2263篇 |
1995年 | 2195篇 |
1994年 | 1818篇 |
1993年 | 1639篇 |
1992年 | 1462篇 |
1991年 | 1358篇 |
1990年 | 1211篇 |
1989年 | 1177篇 |
1988年 | 1186篇 |
1987年 | 1140篇 |
1986年 | 1151篇 |
1985年 | 1128篇 |
1984年 | 1339篇 |
1983年 | 1255篇 |
1982年 | 1463篇 |
1981年 | 1393篇 |
1980年 | 1229篇 |
1979年 | 842篇 |
1978年 | 868篇 |
1977年 | 719篇 |
1976年 | 679篇 |
1975年 | 565篇 |
1974年 | 588篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
62.
The absolute activities of the pure beta-emitters 89Sr and 90Y have been determined by a direct method, namely the triple-to-double coincidence ratio (TDCR) efficiency calculation technique. This undertaking has extended further the number of radionuclides that have been standardized by this non-extrapolation liquid scintillation (LS) method. Both measurements were carried out within the framework of international key comparisons under the auspices of the International Bureau of Weights and Measures (BIPM). The TDCR results agreed well with those of other participating national laboratories, most using alternative (tracer) methods. 相似文献
63.
64.
Noriyoshi Kurihara Hua Zhou Sakamuri V Reddy Veronica Garcia Palacios Mark A Subler David W Dempster Jolene J Windle G David Roodman 《Journal of bone and mineral research》2006,21(3):446-455
We targeted the MVNP gene to the OCL lineage in transgenic mice. These mice developed abnormal OCLs and bone lesions similar to those found in Paget's patients. These results show that persistent expression of MVNP in OCLs can induce pagetic-like bone lesions in vivo. INTRODUCTION: Paget's disease (PD) of bone is the second most common bone disease. Both genetic and viral factors have been implicated in its pathogenesis, but their exact roles in vivo are unclear. We previously reported that transfection of normal human osteoclast (OCL) precursors with the measles virus nucleocapsid (MVNP) or measles virus (MV) infection of bone marrow cells from transgenic mice expressing a MV receptor results in formation of pagetic-like OCLs. MATERIALS AND METHODS: Based on these in vitro studies, we determined if the MVNP gene from either an Edmonston-related strain of MV or a MVNP gene sequence derived from a patient with PD (P-MVNP), when targeted to cells in the OCL lineage of transgenic mice with the TRACP promoter (TRACP/MVNP mice), induced changes in bone similar to those found in PD. RESULTS: Bone marrow culture studies and histomorphometric analysis of bones from these mice showed that their OCLs displayed many of the features of pagetic OCLs and that they developed bone lesions that were similar to those in patients with PD. Furthermore, IL-6 seemed to be required for the development of the pagetic phenotype in OCLs from TRACP/MVNP mice. CONCLUSIONS: These results show that persistent expression of the MVNP gene in cells of the OCL lineage can induce pagetic-like bone lesions in vivo. 相似文献
65.
66.
David L. Healey B.D.S. Nicholas P. Chandler B.D.S. F.D.S. F.F.D. 《The Journal of prosthetic dentistry》1991,66(6):727-729
Experiments were performed to determine the effect of pin channel preparation with standard and reduction speed handpieces, and pin seating by hand and with motor drive. The greatest retention was achieved by preparation with a standard handpiece at 6000 rpm, and manual pin placement with a hand driver. The most consistent retention values were achieved using the reduction handpiece. All preparation and placement combinations examined produced a clinically acceptable result. 相似文献
67.
D. W. Barnes, D. A. Sirbasku & G. H. Sato, (eds.): Cell culture methods for molecular and cell biology. P. M. Gootman (ed.): Developmental neurobiology of the autonomic nervous system. M. Sandler, C. Feuerstein, B. Scatton (eds.): Neurotransmitter interactions in the basal ganglia. Harry M. Zimmerman (ed). Progress in neuropathology. M. Yahr & K. J. Bergmann (eds.): Parkinson's disease. G. Bock & M. O'Connor (eds.): Selective neuronal death. H. Julia Hannay (ed.): Experimental techniques in human neuropsychology. D. Papakostopoulos, S. Butler, I. Martin (eds.): Clinical and experimental neuropsychophysiology J. C. Rothwell: Control of human voluntary movement. 相似文献
68.
Curative local excision of rectal adenocarcinoma 总被引:3,自引:0,他引:3
The records of all 28 patients with rectal adenocarcinoma treated by potentially curative local excision by one surgeon (A.M.C.) between 1970 and 1984 were reviewed. Patient age, sex, tumour size, site, degree of differentiation and level of invasion are reported. The procedure was associated with no mortality and minimal morbidity. Twenty-two patients, followed for an average of 51 months, have either died of other causes or remain free of recurrent or disseminated malignancy. Six patients have required further surgery for local recurrence. Of these, one patient has had a repeat local excision while the remaining five patients have had an abdominoperineal excision of the rectum. All six patients, followed since the second operation for an average of 50 months, are free of further recurrent or disseminated disease. The results reported in this review suggest that in a selected group of patients with rectal adenocarcinoma curative local excision may offer a safe alternative to more radical forms of surgery. 相似文献
69.
70.
In a study of rock music preferences, listening/watching behavior, and views on destructive rock lyrics, 894 adolescents in grades 9 through 12 in rural, urban, suburban public, and metropolitan parochial schools were administered a questionnaire. Demographic information on parents was also collected. It was found that 17.5% of the students were fans of rock music with lyrics that promote homicide, suicide, or satanic practices (HSSR). Loglinear and multiple regression analyses were used to analyze the data. Parents' marital status, student sex, race, and school environment (urban, rural, suburban, etc.) were found to be significant predictors of HSSR status. As compared with non-HSSR fans, the HSSR fans were more likely to have parents who were “Never married” or “Remarried” and less likely to have parents in the “married” category. The HSSR fans were more likely to be male, white, and enrolled in urban schools but not parochial schools than expected; HSSR status also significantly predicted other music-related attitudes and behaviors. The HSSR fans reported liking both the sound and the lyrics of rock music more often than did non-HSSR fans, as did females and urban students. The HSSR fans more often felt that children under 10 years of age should be allowed to listen to HSSR lyrics, and they more frequently expressed the conviction that HSSR music does not affect adolescents' homicidal or self-destructive behavior. The HSSR fans and females reported more nearly complete knowledge of lyrics than did non-HSSR fans and males. The HSSR fans reported that they watch more MTV than did any other group except rural students. 相似文献