全文获取类型
收费全文 | 65017篇 |
免费 | 4862篇 |
国内免费 | 139篇 |
专业分类
耳鼻咽喉 | 507篇 |
儿科学 | 2415篇 |
妇产科学 | 2046篇 |
基础医学 | 8028篇 |
口腔科学 | 984篇 |
临床医学 | 10856篇 |
内科学 | 11748篇 |
皮肤病学 | 1039篇 |
神经病学 | 5607篇 |
特种医学 | 1411篇 |
外国民族医学 | 33篇 |
外科学 | 6207篇 |
综合类 | 1015篇 |
一般理论 | 87篇 |
预防医学 | 8675篇 |
眼科学 | 780篇 |
药学 | 3745篇 |
1篇 | |
中国医学 | 104篇 |
肿瘤学 | 4730篇 |
出版年
2023年 | 348篇 |
2022年 | 517篇 |
2021年 | 1202篇 |
2020年 | 805篇 |
2019年 | 1296篇 |
2018年 | 1481篇 |
2017年 | 1057篇 |
2016年 | 1193篇 |
2015年 | 1300篇 |
2014年 | 1762篇 |
2013年 | 3044篇 |
2012年 | 4248篇 |
2011年 | 4487篇 |
2010年 | 2442篇 |
2009年 | 2256篇 |
2008年 | 3992篇 |
2007年 | 4503篇 |
2006年 | 4313篇 |
2005年 | 4211篇 |
2004年 | 4097篇 |
2003年 | 3866篇 |
2002年 | 3672篇 |
2001年 | 711篇 |
2000年 | 631篇 |
1999年 | 720篇 |
1998年 | 830篇 |
1997年 | 668篇 |
1996年 | 574篇 |
1995年 | 499篇 |
1994年 | 472篇 |
1993年 | 481篇 |
1992年 | 549篇 |
1991年 | 490篇 |
1990年 | 447篇 |
1989年 | 415篇 |
1988年 | 351篇 |
1987年 | 393篇 |
1986年 | 352篇 |
1985年 | 405篇 |
1984年 | 356篇 |
1983年 | 362篇 |
1982年 | 377篇 |
1981年 | 350篇 |
1980年 | 286篇 |
1979年 | 277篇 |
1978年 | 211篇 |
1977年 | 228篇 |
1976年 | 209篇 |
1975年 | 181篇 |
1973年 | 187篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
171.
172.
Demetrius Ellis Ron Shapiro Mark L. Jordan Velma P. Scantlebury Nisan Gilboa Laszlo Hopp Nancy Weichler Andreas G. Tzakis Richard L. Simmons 《Pediatric nephrology (Berlin, Germany)》1994,8(2):193-200
Clinical aspects of FK-506 or cyclosporine immunosuppression regimens were evaluated in 48 consecutive pediatric renal transplant recipients. Tapering and discontinuation of prednisone was employed only in children receiving FK-506 who experienced minor or no rejection episodes during the 1st posttransplant month. At 1 year follow-up, 17 of 22 (77%) of all children with functioning allografts were receiving no prednisone (n=13) or a mean dosage of 0.07 mg/kg per day (n=4). During the 1st month, acute cellular rejection was more common in the FK-506 group (0.58 vs. 0.21 rejections per patient,P<0.05) but allograft survival (92%) and renal function at 1 year posttransplant were identical in both groups. Compared with the cyclosporine regimen, FK-506 immunosuppression may be associated with a higher incidence of cytomegalovirus or reversible Epstein-Barr virus-induced lymphoproliferative disease. However, the FK-506 group had less hirsutism and gingival hypertrophy and required fewer antihypertensive medications independent of steroid use. Height standard deviation scores and weight-for-height index improved only in preadolescents receiving FK-506 but no prednisone (P<0.02 andP<0.05, respectively), but did not differ between children on FK-506 plus prednisone and those in the cyclosporine group. We conclude that the major advantages of FK-506 over cyclosporine immunosuppression are a reduced severity of hypertension and an improved cosmetic appearance which may improve long-term medical compliance. When used as monotherapy, FK-506 also shows promise in relieving the growth retardation associated with cyclosporine regimens that include prednisone. 相似文献
173.
Amy S. Pikalow Mary E. Flynn Robert L. Searls 《Anatomical record (Hoboken, N.J. : 2007)》1994,238(3):407-414
Experiments were done to investigate the cause of the cranial (mesencephalic) flexure of the chick brain during stages 10 to 14. Measurements of the length and thickness of the roof and floor of the mesencephalon gave values similar to the values obtained previously by others. The labeling index was determined in the roof and floor of the prosencephalon, mesencephalon, and rhombencephalon as a preliminary measure of cell division. The labeling index was about the same in all regions, and was high enough to suggest that most of the cells were dividing. The labeling indices did not suggest that differential growth was caused by differential rates of cell division in the roof and floor of the mesencephalon. It was found through time lapse photography that the foregut and heart remained stationary along the rostrocaudal axis, whereas the prosencephalon moved rostrally and the mesencephalon underwent flexure. Measurements suggested that the neural tube cranial to the otic primordium grew in volume exponentially at a rate consistent with the labeling index. The rostral tip of the neural tube was observed to be linked to the rostral tip of the foregut by the ectoderm that formed Rathke's pouch at the neural tube and the pharyngeal membrane (prospective stomodeum) at the foregut. As the neural tube grew in length, the link between the neural tube and the foregut did not. We suggest that because of this link, the growing neural tube had to bend around the foregut, forming the cranial flexure, and the ectoderm folded where it attached to the prosencephalon, forming Rathke's pouch. © 1994 Wiley-Liss, Inc. 相似文献
174.
175.
176.
177.
178.
179.
The relationship of drinking and birth outcome in a US national sample of expectant mothers 总被引:3,自引:0,他引:3
Vivian B. Faden Barry I. Graubard & Mary Dufour 《Paediatric and perinatal epidemiology》1997,11(2):167-180
Alcohol consumption by pregnant women and birth outcome were studied in 9953 livebirths, 3309 fetal deaths and 5332 infant deaths from the 1988 National Maternal and Infant Health Survey. In crude analyses, race, age, mother's education, prenatal care, parity, low birthweight, gestational age, smoking and alcohol consumption during pregnancy were significantly related to the occurrence of fetal deaths and infant deaths. Among women having livebirths, race, age, mother's education, prenatal care, prematurity, gestational age, smoking and alcohol consumption during pregnancy were significantly related to having a low birthweight baby (< 2500 g). In this group, women who drank more during pregnancy also smoked more, were younger and less educated than women who drank at lower levels or not at all. The relationship of alcohol consumption during pregnancy and infant birthweight for those women having livebirths was studied using multivariable linear regression. The results indicated that race, mother's education, baby's sex, parity, mother's height, mother's body mass index and smoking, but not alcohol consumption, were significantly related to birthweight. Multivariable logistic regressions were performed for the occurrence of low birthweight, fetal death and infant death. The effect of alcohol was significant in all these analyses. These results indicate that alcohol has an important relationship with birth outcome, but that for the drinking reported in this study, the alcohol effect on mean birthweight is small relative to that of other risk factors, accounting for the non-significant result in the multiple linear regression. 相似文献
180.
Promoting autonomy and independence for older people within nursing practice: a literature review 总被引:1,自引:0,他引:1
Sue Davies Bsc Msc RGN RHV Sara Laker BA RGN Lorraine Ellis BA MSc RGN RNT 《Journal of advanced nursing》1997,26(2):408-417
The principles of promoting autonomy and independence underpin many approaches to improving the quality of nursing care for older people in whatever setting, and are in line with wider developments in health care such as the Patient's Charter. However, these concepts require careful definition if nursing practices which might promote autonomy and independence are to be identified. Although the generalizability of the research-based literature in this field is limited by a focus upon older people in continuing-care settings, a review of the literature found a number of indicators associated with attempts to promote patient autonomy and independence. These were grouped into the following categories: systems of care delivery which promote comprehensive individualized assessment and multidisciplinary care planning; attempts to encourage patients/clients to participate in decisions about their care; patterns of communication which avoid exerting power and control over patients/clients and attempts to modify the environment to promote independence and minimize risk. It is suggested that the review identifies a number of principles for nursing practice which can be applied in a range of care settings in order to promote the autonomy and independence of older people. 相似文献