全文获取类型
收费全文 | 2177篇 |
免费 | 284篇 |
国内免费 | 24篇 |
专业分类
耳鼻咽喉 | 26篇 |
儿科学 | 61篇 |
妇产科学 | 42篇 |
基础医学 | 149篇 |
口腔科学 | 88篇 |
临床医学 | 313篇 |
内科学 | 517篇 |
皮肤病学 | 79篇 |
神经病学 | 135篇 |
特种医学 | 308篇 |
外科学 | 236篇 |
综合类 | 21篇 |
预防医学 | 315篇 |
眼科学 | 16篇 |
药学 | 66篇 |
肿瘤学 | 113篇 |
出版年
2023年 | 53篇 |
2022年 | 19篇 |
2021年 | 20篇 |
2020年 | 46篇 |
2019年 | 29篇 |
2018年 | 64篇 |
2017年 | 44篇 |
2016年 | 58篇 |
2015年 | 69篇 |
2014年 | 108篇 |
2013年 | 137篇 |
2012年 | 82篇 |
2011年 | 85篇 |
2010年 | 80篇 |
2009年 | 101篇 |
2008年 | 79篇 |
2007年 | 107篇 |
2006年 | 88篇 |
2005年 | 70篇 |
2004年 | 66篇 |
2003年 | 43篇 |
2002年 | 35篇 |
2001年 | 30篇 |
2000年 | 27篇 |
1999年 | 39篇 |
1998年 | 71篇 |
1997年 | 92篇 |
1996年 | 84篇 |
1995年 | 62篇 |
1994年 | 63篇 |
1993年 | 55篇 |
1992年 | 22篇 |
1991年 | 18篇 |
1990年 | 41篇 |
1989年 | 50篇 |
1988年 | 35篇 |
1987年 | 37篇 |
1986年 | 33篇 |
1985年 | 37篇 |
1984年 | 16篇 |
1983年 | 14篇 |
1982年 | 29篇 |
1981年 | 37篇 |
1980年 | 22篇 |
1979年 | 9篇 |
1978年 | 7篇 |
1977年 | 16篇 |
1976年 | 16篇 |
1975年 | 10篇 |
1965年 | 5篇 |
排序方式: 共有2485条查询结果,搜索用时 15 毫秒
991.
992.
993.
994.
The author explores the costs and impact of capital punishment on society's ability to address social ills that precede criminal behavior–lack of access to health care, child abuse, domestic violence, drug addictions, and poverty. Two case studies are used to demonstrate that the death penalty is applied arbitrarily against the disadvantaged, the mentally ill, and the retarded. The author asserts that nurses must not support killing people, and challenges nurses to find ways to address community health issues to provide alternatives to capital punishment. 相似文献
995.
996.
Susceptibility locus for inflammatory bowel disease on chromosome 16 has a role in Crohn's disease, but not in ulcerative colitis 总被引:10,自引:1,他引:9
Ohmen JD; Yang HY; Yamamoto KK; Zhao HY; Ma Y; Bentley LG; Huang Z; Gerwehr S; Pressman S; McElree C; Targan S; Rotter JI; Fischel-Ghodsian N 《Human molecular genetics》1996,5(10):1679-1683
In the Western world, chronic inflammatory bowel disease (IBD) presents as
two major clinical forms, Crohn's disease (CD) and ulcerative colitis (UC)
[Targan, S.R. and Shanahan, F. (1994). In Retford, D.C (ed.), Inflammatory
Bowel Disease: From Bench to Bedside. Williams and Wilkins, Baltimore].
Genetic epidemiological studies, the occurrence of rare syndromes
associated with IBD, and animal models suggest that inherited factors play
significant roles in the susceptibility to both forms of IBD [Yang, H.-Y.
and Rotter, J.I. (1995) In Kirsner, J.B. and Shorter, R.G. (eds). Genetic
Aspects of Idiopathic Inflammatory Bowel Disease. Williams and Wilkins,
Baltimore, pp.301-331]. Recently, a genome-wide search on European families
with multiple affected members with CD identified a putative susceptibility
locus in the centromeric region of chromosome 16 [Hugot, J.-P. et al.
(1996) Nature, 379, 821- 823]. We have now tested this region in an
independent set of US families, confirmed that this region is likely to
contain a gene predisposing to CD, and further refined the chromosomal
location of this gene. Most importantly with respect to this locus, our
data also seem to indicate that there is heterogeneity both within the CD
group, and between the CD and UC groups with respect to this locus. The
susceptibility locus appears to be involved only in non-Jewish CD sibpairs
and not in our Ashkenazi Jewish CD sibpairs. Additionally, we have tested
sibpairs having either only UC or both UC and CD for involvement of this
locus, and have found no evidence that this region predisposes to IBD in
these patients.
相似文献
997.
998.
J W Wong E D Slessinger R E Hermes C J Offutt T Roy M W Vannier 《International journal of radiation oncology, biology, physics》1990,18(6):1455-1463
The comparison of a predicted portal dose image, calculated during treatment planning, with the measured image obtained during treatment is proposed as an approach to verify the correct implementation of a patient treatment plan. The comparison inherently verifies both the geometric alignment and the dose delivered. Feasibility studies were conducted with 60Co irradiation of a modular plastic phantom, an anthropomorphic phantom and a patient with lung cancer. Calculations were made with the 3-dimensional scatter ray-trace Delta Volume method. Calculated distributions and/or selected points of transmitted dose correction factors were compared with measurements made with TLD, scanning ionization chamber and film. For the two phantom studies, excellent agreement, usually to within 3%, was achieved when positioning of the phantoms were accurate. The patient study showed that selected point comparisons were inadequate in identifying the cause of errors when disagreement occurred. Simple subtraction of the calculated and measured images showed a 4 mm translational misalignment. The results are encouraging and demonstrate that portal dose images can be used to detect large geometric and dosimetric discrepancies between treatment plan calculations and measurements. The results also show that perfect verification is virtually impossible in the clinical situation. More work is required to use the verification information for improving the estimation of dose to the patient. 相似文献
999.
A linear specular reflection simulating a membrane was visualized along the back of the neck on sonograms of ten normal fetuses ranging in age from 10 to 14 menstrual weeks. Follow-up ultrasound studies of eight of the fetuses and postpartum clinical examinations of all subjects were normal, revealing no evidence of neck abnormalities. Although this pseudomembrane is similar in appearance to published examples of early cystic hygroma, it is a normal finding that can be distinguished from early cystic hygroma on the basis of its less bulbous appearance and the absence of underlying septations. This structure corresponds in distribution to the skin along the back of the fetus and likely represents a specular reflection from the skin surface. 相似文献
1000.