全文获取类型
收费全文 | 664篇 |
免费 | 42篇 |
国内免费 | 4篇 |
专业分类
耳鼻咽喉 | 1篇 |
儿科学 | 41篇 |
妇产科学 | 12篇 |
基础医学 | 89篇 |
口腔科学 | 28篇 |
临床医学 | 45篇 |
内科学 | 120篇 |
皮肤病学 | 16篇 |
神经病学 | 11篇 |
特种医学 | 144篇 |
外国民族医学 | 1篇 |
外科学 | 38篇 |
综合类 | 50篇 |
预防医学 | 51篇 |
眼科学 | 5篇 |
药学 | 22篇 |
中国医学 | 4篇 |
肿瘤学 | 32篇 |
出版年
2021年 | 8篇 |
2020年 | 6篇 |
2019年 | 5篇 |
2018年 | 13篇 |
2017年 | 11篇 |
2016年 | 14篇 |
2015年 | 12篇 |
2014年 | 18篇 |
2013年 | 31篇 |
2012年 | 31篇 |
2011年 | 19篇 |
2010年 | 43篇 |
2009年 | 44篇 |
2008年 | 23篇 |
2007年 | 21篇 |
2006年 | 12篇 |
2005年 | 8篇 |
2004年 | 7篇 |
2003年 | 5篇 |
2002年 | 4篇 |
2001年 | 6篇 |
2000年 | 6篇 |
1999年 | 7篇 |
1998年 | 34篇 |
1997年 | 33篇 |
1996年 | 34篇 |
1995年 | 35篇 |
1994年 | 23篇 |
1993年 | 20篇 |
1992年 | 4篇 |
1991年 | 4篇 |
1990年 | 7篇 |
1989年 | 15篇 |
1988年 | 14篇 |
1987年 | 10篇 |
1986年 | 13篇 |
1985年 | 9篇 |
1984年 | 12篇 |
1983年 | 14篇 |
1982年 | 12篇 |
1981年 | 13篇 |
1980年 | 15篇 |
1979年 | 4篇 |
1978年 | 8篇 |
1977年 | 2篇 |
1976年 | 8篇 |
1975年 | 5篇 |
1955年 | 1篇 |
1950年 | 1篇 |
1949年 | 1篇 |
排序方式: 共有710条查询结果,搜索用时 10 毫秒
31.
B. KAPPEL J. NIELSEN K. BROGAARD HANSEN M. MIKKELSEN AA. J. THERKELSEN 《BJOG : an international journal of obstetrics and gynaecology》1987,94(1):50-54
Summary. The clinical significance of placental perforation and bloodstained amniotic fluid was studied in a group of 7238 Danish women undergoing mid-trimester amniocentesis for prenatal diagnosis under ultrasound guidance. The risk of spontaneous abortion was significantly increased both in pregnancies where the placenta was perforated and in those with blood-stained amniotic fluid. The risk estimate nearly doubled after placental perforation and more than doubled with a bloody tap. It is concluded that for women at relatively low risk of a fetal genetic abnormality, the indication of the amniocentesis should be reconsidered if a placental perforation is unavoidable. 相似文献
32.
Moderate and severe malnutrition are endemic in much of the developing world and in association with pockets of deprivation in the developed world. The cost in terms of individual and social development is high. The principles of effective management are clearly documented. A low cost, community based treatment programme for moderately and severely malnourished children under 3 years of age was established at a health centre in rural Jamaica. Children were followed up monthly and defaulters were rigorously recalled. Management consisted of carefully delivered dietary advice, antibiotics, anthelminthics, and vitamin supplements. All children improved and the response of 36 children, who were treated in the first year, showed an accelerated weight gain, with catch-up growth and the maintenance of length gain. There was a significant increase in the weight for age, at 1.9% per month over six months, which exceeds the rate reported with food supplementation programmes and nutrition rehabilitation centres. 相似文献
33.
Pathophysiologic considerations as well as non-comparative clinical results suggest that very high purity concentrates may slow immunologic deterioration in human immunodeficiency virus (HIV)-infected hemophiliacs. In an attempt to evaluate this hypothesis, we prospectively compared CD4 cell counts, skin testing responses, and changes of the clinical status in 20 asymptomatic HIV-positive hemophiliacs, randomly assigned to continue the treatment with an intermediate purity concentrate or to receive a very high purity product, purified by immunoaffinity chromatography with monoclonal antibodies. In the group switched to the very high purity concentrate there was no significant change of the CD4 cell counts over the 96-week follow-up period, whereas in the group continued on the intermediate purity concentrate, a highly significant decline was detected (P less than .013). Furthermore, in the very high purity group, four of six anergic patients at entry acquired reactivity to skin testing. The results of this study clearly support the use of very high purity concentrates for the replacement therapy of HIV-infected hemophiliacs. 相似文献
34.
Masclee AA; Hopman WP; Corstens FH; Rosenbusch G; Jansen JB; Lamers CB 《Radiology》1989,173(2):407-410
Both ultrasonography (US) and cholescintigraphy are used to study gallbladder dynamics. The present study was undertaken to determine whether the two methods provide the same or different information relating to gallbladder emptying. Emptying was simultaneously studied with both methods during infusion of graded physiologic doses of cholecystokinin (CCK) in six healthy subjects. Infusion of stepwise increasing doses of CCK, ranging from 0.03 to 0.5 Ivy dog units per kilogram of body weight per hour (IDU/kg.h), induced significant dose-related increases in plasma CCK, decreases in gallbladder volume assessed with US, and gallbladder emptying assessed with cholescintigraphy. The threshold dose for inducing significant gallbladder emptying was 0.13 IDU/kg.h, as determined with both techniques, indicating similar detection limits. There was a highly significant correlation between decreases in gallbladder volume and decreases in radioactive counts over the gallbladder region, with a tendency toward greater gallbladder responses at sonography during the early phase of gallbladder contraction and toward greater responses at cholescintigraphy during the later phase of gallbladder contraction. It is concluded that these methods can be used interchangeably for the quantitation of gallbladder emptying. 相似文献
35.
36.
Direct demonstration of transsynaptic degeneration in the human visual system: a comparison of retrograde and anterograde changes 总被引:1,自引:0,他引:1 下载免费PDF全文
RM Beatty AA Sadun LEH Smith JP Vonsattel EP Richardson Jr 《Journal of neurology, neurosurgery, and psychiatry》1982,45(2):143-146
Transneuronal degeneration of retinal ganglion cells was directly demonstrated in a patient who had unilateral removal of the striate cortex forty years prior to necropsy. For comparison, another case is presented showing anterograde transneuronal atrophy forty years after enucleation of one eye. 相似文献
37.
CT evaluation of complications of abdominal aortic surgery 总被引:5,自引:0,他引:5
38.
39.
Introduction: Increased stress levels have been reported and it has been implicated for mental illness amongst service personnel. However no study has been reported among Indian naval sailors. 相似文献
40.