全文获取类型
收费全文 | 4467篇 |
免费 | 459篇 |
国内免费 | 204篇 |
专业分类
耳鼻咽喉 | 57篇 |
儿科学 | 132篇 |
妇产科学 | 111篇 |
基础医学 | 350篇 |
口腔科学 | 60篇 |
临床医学 | 462篇 |
内科学 | 608篇 |
皮肤病学 | 56篇 |
神经病学 | 122篇 |
特种医学 | 242篇 |
外科学 | 513篇 |
综合类 | 784篇 |
预防医学 | 404篇 |
眼科学 | 71篇 |
药学 | 475篇 |
7篇 | |
中国医学 | 420篇 |
肿瘤学 | 256篇 |
出版年
2024年 | 19篇 |
2023年 | 52篇 |
2022年 | 91篇 |
2021年 | 138篇 |
2020年 | 118篇 |
2019年 | 72篇 |
2018年 | 106篇 |
2017年 | 89篇 |
2016年 | 93篇 |
2015年 | 164篇 |
2014年 | 198篇 |
2013年 | 226篇 |
2012年 | 323篇 |
2011年 | 332篇 |
2010年 | 254篇 |
2009年 | 257篇 |
2008年 | 242篇 |
2007年 | 266篇 |
2006年 | 220篇 |
2005年 | 155篇 |
2004年 | 116篇 |
2003年 | 115篇 |
2002年 | 113篇 |
2001年 | 90篇 |
2000年 | 50篇 |
1999年 | 21篇 |
1998年 | 38篇 |
1997年 | 39篇 |
1996年 | 38篇 |
1995年 | 40篇 |
1994年 | 30篇 |
1993年 | 45篇 |
1992年 | 31篇 |
1991年 | 32篇 |
1990年 | 24篇 |
1989年 | 23篇 |
1988年 | 31篇 |
1987年 | 22篇 |
1986年 | 32篇 |
1985年 | 36篇 |
1984年 | 30篇 |
1983年 | 33篇 |
1981年 | 15篇 |
1979年 | 17篇 |
1959年 | 49篇 |
1958年 | 103篇 |
1957年 | 108篇 |
1956年 | 80篇 |
1955年 | 83篇 |
1954年 | 67篇 |
排序方式: 共有5130条查询结果,搜索用时 15 毫秒
1.
多级图像对比度放大技术在膝关节摄影中的应用 总被引:1,自引:0,他引:1
目的:分析评价膝关节摄影中多级图像对比度放大技术(MUSICA)参数设定的成像效果,为实际临床应用提供理论指导。方法:随机抽取膝关节侧位软拷贝图像70例,以骨皮质、骨小梁、肌间隙、髌上囊、皮下脂肪为比对目标,由三位观察者对其显示情况进行分析,并对结果进行统计分析。结果:MUSICA处于较小值(0~2)时,适合于软组织显示,但图像锐利度欠缺;处于较高值时(4~6)适合于观察骨皮质、小梁等细节信息,但较多地出现伪影,共25例;处于2~4时整体影像对比度适中,如实反映人体密度结构。结论:作图像处理时应将MUSICA为2~4设定为常规,实际应用通常情况下可以选择该处理方法,但应根据具体要求适当调整MUSICA参数值。 相似文献
2.
以链脲佐菌素制备糖尿病大鼠模型,造模后以还原型谷胱甘肽(GSH)治疗12周,结果显示GSH治疗组较糖尿病组心肌组织病理学损害改善,NF—κB活性降低,诱导型一氧化氮合酶表达下降。 相似文献
3.
4.
5.
6.
We report the case of a 26-year-old man affected by a symmetrical keratoderma localized to the interdigital spaces of the fingers. No occupational, traumatic, or irritant factors were discovered. Clinical and histological features were consistent with the diagnosis of symmetrical interdigital hyperkeratosis, a sporadic disorder described by Frei in 1926. We believe this condition to be less rare than the few cases reported in the literature would suggest. 相似文献
7.
8.
Ian Gooding Vicky Dondos Khin Ma Gyi Margaret Hodson David Westaby 《Liver transplantation》2005,11(12):1522-1526
Autopsy and imaging studies show that liver involvement is common in cystic fibrosis. However, complications of chronic liver disease including portal hypertension and variceal bleeding are infrequently encountered, and the degree to which variceal hemorrhage affects prognosis in cystic fibrosis is unclear. This uncertainty has lead to debate as to whether liver transplantation is indicated in these patients. We describe a case series of 18 patients and compare their survival with a control group of cystic fibrosis patients without liver disease. The median age at first bleed was 20.0 years (range 9.7-30.9). The median survival after first bleed was 8.4 years, compared to 13.0 years in the control group (P = 0.15). A total of 14 patients have died, 9 from respiratory disease with no discernable contribution from their liver disease. Liver disease contributed to 4 deaths. Only 1 patient suffered a fatal hemorrhage, which may have been either variceal or bronchial in origin. Long-term survival is a frequent occurrence in patients with cystic fibrosis who suffer variceal hemorrhage, and age at death is comparable to the general cystic fibrosis population. In conclusion, this suggests that liver transplantation is not indicated in these patients without additional features of liver decompensation. 相似文献
9.
Maximal static expiratory and inspiratory mouth pressures (PEmax and PImax) and quadriceps femoris muscle strength were measured in 25 patients aged 16-28 years with cystic fibrosis (mean FEV1 46% predicted). Mean (SD) PEmax was 64% (18%) predicted (below 75% predicted in 16 of the 25 patients), and PImax was 64% (24%) predicted (below 75% predicted in 14 patients). Quadriceps muscle strength was 68% (20%) predicted (below 75% predicted in 17 patients). The relatively small reduction in respiratory muscle strength in these patients was unlikely to have contributed appreciably to their respiratory problems. 相似文献
10.
A H Cohen R Soden S A Martin S Liss W L Hodson M Meyer 《Journal of the American Optometric Association》1987,58(5):386-389
As an essential element of the comprehensive rehabilitation efforts at Northport VA Medical Center, and as a service whose demand is projected to increase substantially with the expanding proportion of aging veterans, eye/vision care has become increasingly important. As a result, the administration of the Medical Center decided to heed the suggestions of Congress and the Director of Optometry in VA Central Office and reorganize the delivery of eye/vision services so the ever-increasing demand could be met more rationally, efficiently and effectively. In this paper, the Northport VA Medical Center's Comprehensive Eye/Vision Program, including the residency program in rehabilitative optometry, will be described and the benefits of the reorganization will be discussed. 相似文献