全文获取类型
收费全文 | 2369094篇 |
免费 | 173383篇 |
国内免费 | 3376篇 |
专业分类
耳鼻咽喉 | 32181篇 |
儿科学 | 76542篇 |
妇产科学 | 63227篇 |
基础医学 | 350669篇 |
口腔科学 | 64267篇 |
临床医学 | 213526篇 |
内科学 | 460953篇 |
皮肤病学 | 52000篇 |
神经病学 | 187301篇 |
特种医学 | 88633篇 |
外国民族医学 | 492篇 |
外科学 | 356463篇 |
综合类 | 47946篇 |
现状与发展 | 12篇 |
一般理论 | 882篇 |
预防医学 | 184694篇 |
眼科学 | 54919篇 |
药学 | 176350篇 |
12篇 | |
中国医学 | 4607篇 |
肿瘤学 | 130177篇 |
出版年
2021年 | 19203篇 |
2019年 | 19798篇 |
2018年 | 27335篇 |
2017年 | 20631篇 |
2016年 | 23005篇 |
2015年 | 25920篇 |
2014年 | 36531篇 |
2013年 | 54622篇 |
2012年 | 75567篇 |
2011年 | 80493篇 |
2010年 | 47659篇 |
2009年 | 45070篇 |
2008年 | 75527篇 |
2007年 | 80376篇 |
2006年 | 81234篇 |
2005年 | 78755篇 |
2004年 | 75223篇 |
2003年 | 72544篇 |
2002年 | 70204篇 |
2001年 | 109276篇 |
2000年 | 111963篇 |
1999年 | 93956篇 |
1998年 | 27223篇 |
1997年 | 23868篇 |
1996年 | 24246篇 |
1995年 | 22889篇 |
1994年 | 21051篇 |
1993年 | 19902篇 |
1992年 | 72400篇 |
1991年 | 70434篇 |
1990年 | 68767篇 |
1989年 | 66006篇 |
1988年 | 60649篇 |
1987年 | 59425篇 |
1986年 | 55502篇 |
1985年 | 53280篇 |
1984年 | 39520篇 |
1983年 | 33604篇 |
1982年 | 20025篇 |
1979年 | 36106篇 |
1978年 | 25836篇 |
1977年 | 21388篇 |
1976年 | 20461篇 |
1975年 | 21939篇 |
1974年 | 26319篇 |
1973年 | 24960篇 |
1972年 | 23343篇 |
1971年 | 22155篇 |
1970年 | 20353篇 |
1969年 | 19408篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
161.
Birth weight on 12,644 singleton infants from 6,196 sibships born in Maryland between 1980 and 1984 were used to estimate the effects of nine maternal and infant covariates on the sibship correlation in birth weight. Assuming a homogeneous correlation across all families, the estimated intraclass correlation was 0.4664 (+/- 0.0099). This high sibship correlation makes it possible to predict, with reasonable accuracy, the birth weight of a child given information on previous sibs, as well as covariates on the mother and/or infant pertinent to a given pregnancy. The reduction in variance associated with incorporating information on the nine covariates used here was approximately equal to that obtained by conditioning on a single previous sib. Testing for heterogeneity in correlation among different groups of families showed that a crude measure of parity (first live birth vs. other), time between births, mother's marital status, and maternal age at the birth of the last child significantly influenced the sibship correlation in birth weight. 相似文献
162.
163.
164.
165.
166.
167.
K A Burkman R W Gaines S R Kashani R D Smith 《Archives of physical medicine and rehabilitation》1988,69(2):132-134
Herpes zoster probably occurs more often than generally thought. Since it produces a radicular distribution of pain, it should be included in the differential diagnosis of radiculopathy. A case is presented in which evaluating the radicular low back pain before the characteristic rash appears was misleading. Careful history-taking concerning the exact nature of the pain and sensory changes is needed to differentiate between zoster and radiculopathy, if no rash is evident. 相似文献
168.
169.
Eledoisin has been tried as a possible treatment for dry eye based on the hypothesis that it pharmacologically stimulates tear secretion when topically applied to the eye. To determine if topically applied eledoisin pharmacologically stimulates orbital lacrimal secretion, the orbital lacrimal gland excretory duct of normal rabbits was cannulated, and eledoisin was applied topically with and without prior administration of proparacaine. To determine if topically applied eledoisin stimulated accessory lacrimal gland secretion, isotonic buffer with and without eledoisin was tested in a rabbit model with only accessory lacrimal tissue remaining after the administration of proparacaine. Topically applied eledoisin did not pharmacologically stimulate lacrimal secretion but rather increased lacrimal gland secretion only in non-anesthetized eyes through a sensory reflex mechanism that is blocked by proparacaine. 相似文献
170.
R W Hertle A B Leahey S Bloom D B Schaffer S Bartlett 《Ophthalmic plastic and reconstructive surgery》1990,6(4):278-282
Chorioretinal folds have been reported as a result of many intraocular and extraocular inflammatory processes or tumors. Visual loss is usually secondary to a combination of the underlying process and chorioretinal folds involving the macula. We report a patient who developed decreased vision, metamorphopsia, chorioretinal folds, and a lamellar macular hole secondary to global compression by a bone fragment. The chorioretinal folds regressed and his vision stabilized following surgical decompression. Chorioretinal folds and lamellar macular hold formation are previously unrecognized complications of reconstructive craniofacial surgery. 相似文献