全文获取类型
收费全文 | 947篇 |
免费 | 29篇 |
国内免费 | 22篇 |
专业分类
耳鼻咽喉 | 4篇 |
儿科学 | 37篇 |
妇产科学 | 248篇 |
基础医学 | 150篇 |
口腔科学 | 12篇 |
临床医学 | 51篇 |
内科学 | 79篇 |
皮肤病学 | 9篇 |
神经病学 | 8篇 |
特种医学 | 120篇 |
外科学 | 83篇 |
综合类 | 67篇 |
一般理论 | 1篇 |
预防医学 | 23篇 |
眼科学 | 28篇 |
药学 | 35篇 |
肿瘤学 | 43篇 |
出版年
2023年 | 3篇 |
2021年 | 4篇 |
2019年 | 4篇 |
2018年 | 8篇 |
2017年 | 5篇 |
2016年 | 8篇 |
2015年 | 10篇 |
2014年 | 12篇 |
2013年 | 19篇 |
2012年 | 15篇 |
2011年 | 36篇 |
2010年 | 34篇 |
2009年 | 15篇 |
2008年 | 21篇 |
2007年 | 43篇 |
2006年 | 40篇 |
2005年 | 31篇 |
2004年 | 29篇 |
2003年 | 20篇 |
2002年 | 33篇 |
2001年 | 40篇 |
2000年 | 28篇 |
1999年 | 21篇 |
1998年 | 41篇 |
1997年 | 36篇 |
1996年 | 37篇 |
1995年 | 36篇 |
1994年 | 35篇 |
1993年 | 28篇 |
1992年 | 29篇 |
1991年 | 25篇 |
1990年 | 31篇 |
1989年 | 22篇 |
1988年 | 12篇 |
1987年 | 10篇 |
1986年 | 24篇 |
1985年 | 20篇 |
1984年 | 19篇 |
1983年 | 13篇 |
1982年 | 15篇 |
1981年 | 8篇 |
1980年 | 22篇 |
1979年 | 21篇 |
1978年 | 13篇 |
1977年 | 8篇 |
1976年 | 4篇 |
1972年 | 1篇 |
1971年 | 3篇 |
1967年 | 1篇 |
1933年 | 1篇 |
排序方式: 共有998条查询结果,搜索用时 15 毫秒
1.
The authors studied the cumulative probability of pregnancy for up to 4 consecutive embryo transfer (ET) cycles with ICSI performed for male factor. Transfers could be either fresh or frozen. The clinical pregnancy rate (PR) for the first 4 cycles were similar [44% (61/366); 31% (44/138); 45% (14/31); 44% (4/9)]. Delivery rates were also similar. There was a lower PR on the second retrieval vs. the first retrieval (47% vs. 29%), but this may be related to most of the second retrievals occurring in the second transfer cycle (67%, 31/55); this may be explained by women who were poor responders and required another retrieval without a frozen ET. The majority of transfers in cycle 1 were fresh, whereas cycles 2-4 used primarily frozen-thawed embryos. These data should be helpful for patients requiring IVF with ICSI in deciding to continue with more IVF cycles or consider other 相似文献
2.
ZQ Yin MD SG Crewther PhD B Pirie BSc DP Crewther PhD 《Clinical & experimental ophthalmology》1997,25(4):107-109
Purpose: It was investigated whether alterations in neuronal structure and function occasioned by strabismic amblyopia also may be reflected in alterations in the expression on Y type neurons of a Cat-301 antibody sensitive antigen in the lateral geniculate nucleus (LGN) and cortex of our cat model of strabismic amblyopia. Methods/Results: The percentage of positively labelled cells was reduced in LGN laminae that received input from the deviated eye in strabismic amblyopic cats compared with normal cats. In the strabismic cortex, the density of immunopositive neurons was significantly reduced compared with normal, the effect being most pronounced in layer IV Conclusions: Despite previous physiological recordings indicating a decrease in X-cell associated acuity in strabismic amblyopia, the present findings imply that the changes in the early visual experience occasioned by strabismus also produce specific molecular changes in theY neuronal class. 相似文献
3.
The standard semen analysis frequently fails to identify subfertile males even when findings are normal and conversely often fails to identify fertile males with subnormal semen analyses. This has created the need to produce other tests of sperm physiology that will better distinguish a fertile from a subfertile specimen. Understanding more about the nature of the sperm defect should lead to the establishment of more specific and effective therapies. Until that time, it would still be reasonable to try some of the available empirical therapies even though they may work merely by a placebo mechanism. 相似文献
4.
5.
6.
7.
8.
A comprehensive anatomic and radiographic analysis of the peribursal fat plane in 12 cadavers confirmed that the fat plane seen on radiographs represents extrasynovial fat lining the subacromial bursa and documented the anatomic relations of the bursa. A three-part retrospective clinical evaluation of rotator cuff tears, calcific tendinitis, and rheumatoid arthritis was performed. Two osteoradiologists blindly graded the appearance of the peribursal fat plane with the shoulder in external versus internal rotation in 21 patients with arthrographically intact rotator cuffs and 21 patients with disrupted rotator cuffs. The peribursal fat plane was seen better with disrupted rotator cuffs. The peribursal fat plane was seen better with the shoulder in internal rotation and was seen in 60% of control subjects but only 21% of patients with rotator cuff tears. Partial or complete obliteration of this fat plane is a sensitive (79%) but less specific (60%) indicator of rotator cuff tears. Obliteration of the peribursal fat plane by inflammatory processes in adjacent tissues, including calcific tendinitis and rheumatoid arthritis, occurred with a high frequency. 相似文献
9.
J H Check J S Chase K Nowroozi G Goldsmith C Dietterich 《International journal of fertility》1992,37(3):165-166
We describe a woman who conceived by in vitro fertilization (IVF) and embryo transfer (ET). Transvaginal ultrasound demonstrated at least 1 week's difference in size of twin gestations from 1 month post-transfer of embryos to delivery. Differences in sac size, crown-rump length, and gestational growth are discussed, as are implications of ultrasound in early pregnancy. 相似文献
10.
Therapeutic insemination by donor (TDI) was just as successful in achieving pregnancies in couples in whom the male counterparts had subnormal motile densities as in those with normal levels. All wives in this study had an infertility factor that was corrected and remained so for at least 8 months. Thus, motile density may not be a particularly good predictor of male fertility potential. 相似文献