全文获取类型
收费全文 | 1104篇 |
免费 | 86篇 |
国内免费 | 59篇 |
专业分类
耳鼻咽喉 | 2篇 |
儿科学 | 51篇 |
妇产科学 | 15篇 |
基础医学 | 99篇 |
口腔科学 | 19篇 |
临床医学 | 169篇 |
内科学 | 280篇 |
皮肤病学 | 25篇 |
神经病学 | 35篇 |
特种医学 | 235篇 |
外科学 | 79篇 |
综合类 | 39篇 |
一般理论 | 1篇 |
预防医学 | 104篇 |
眼科学 | 12篇 |
药学 | 51篇 |
中国医学 | 2篇 |
肿瘤学 | 31篇 |
出版年
2021年 | 15篇 |
2020年 | 8篇 |
2019年 | 7篇 |
2018年 | 19篇 |
2017年 | 12篇 |
2016年 | 8篇 |
2015年 | 25篇 |
2014年 | 23篇 |
2013年 | 37篇 |
2012年 | 33篇 |
2011年 | 34篇 |
2010年 | 26篇 |
2009年 | 31篇 |
2008年 | 25篇 |
2007年 | 58篇 |
2006年 | 12篇 |
2005年 | 18篇 |
2004年 | 23篇 |
2003年 | 22篇 |
2002年 | 13篇 |
2001年 | 11篇 |
2000年 | 12篇 |
1999年 | 17篇 |
1998年 | 53篇 |
1997年 | 41篇 |
1996年 | 63篇 |
1995年 | 47篇 |
1994年 | 43篇 |
1993年 | 55篇 |
1992年 | 18篇 |
1991年 | 16篇 |
1990年 | 30篇 |
1989年 | 38篇 |
1988年 | 41篇 |
1987年 | 50篇 |
1986年 | 34篇 |
1985年 | 45篇 |
1984年 | 18篇 |
1983年 | 13篇 |
1982年 | 16篇 |
1981年 | 22篇 |
1980年 | 22篇 |
1979年 | 12篇 |
1978年 | 13篇 |
1977年 | 20篇 |
1976年 | 12篇 |
1975年 | 11篇 |
1972年 | 5篇 |
1971年 | 4篇 |
1970年 | 3篇 |
排序方式: 共有1249条查询结果,搜索用时 31 毫秒
1.
Tarandovskiy Ivan D. Rajabi Ali A. Karnaukhova Elena Buehler Paul W. 《Journal of thrombosis and thrombolysis》2019,48(1):81-87
Journal of Thrombosis and Thrombolysis - C1-inhibitor (C1INH) was shown to enhance thrombin generation (TG) in the presence of thrombomodulin (TM) by reducing production of activated protein C.... 相似文献
2.
3.
4.
Public health surveillance of non-infectious chronic diseases: the potential to detect rapid changes in disease burden 总被引:5,自引:0,他引:5
The usefulness of surveillance in relating chronic disease trends to recent changes in risk exposures is often questioned on the grounds that these trends respond slowly, reflecting long periods between aetiological exposures and clinical onset of disease. We challenge this preconception on the basis of a review of several important risk factors and diseases: alcohol and liver cirrhosis; tobacco and stroke, cardiovascular disease, and lung cancer; and oestrogens and endometrial cancer. Data from cohort, cross-sectional, and modelling studies demonstrate that the time between removal of exposures and the onset of decline in morbidity or mortality is not defined by the time between initial exposure and disease occurrence. Rather, the pattern of lifetime exposures (with recent exposures often having a dominant effect), the dynamics of the disease process, and the segment of the population with reduced exposures determine how soon the decline begins. 相似文献
5.
6.
7.
8.
9.
Short-Ti inversion-recovery pulse sequence: analysis and initial experience in cancer imaging 总被引:2,自引:0,他引:2
Inversion recovery (IR), commonly considered a pulse sequence capable of producing T1-weighted images with excellent display of normal anatomy, is versatile: The null point and peak time provide a useful, succinct summary of the properties of IR and its capacity for producing both T1- and T2-weighted images. Shortening of the inversion time (TI) and creation of a short-TI inversion-recovery (STIR) pulse sequence increases sensitivity to malignancy and other abnormalities by making the effects of prolonged T1 and T2 on signal intensity additive and by nulling the signal from fat. The authors examined over 300 patients with various malignancies and compared STIR images with T1- and T2-weighted images obtained at 0.5 T. In 43 cases, signal-difference-to-noise ratios (SD/Ns) were calculated between tumor, fat, and muscle. In general, STIR images demonstrated tumor as a conspicuously high-intensity area in a background of muted, discernible anatomic detail. The good contrast achieved with STIR sequences between tumor and fat (SD/N = 18.1) and tumor and muscle (SD/N = 12.9) consolidated into a single image the information contained separately on T1- and T2-weighted images, which facilitates efficient detection and localization of malignancy. 相似文献
10.
Sixteen cases of histopathologically proved solitary rectal ulcer syndrome were encountered. Fifteen patients underwent barium enema study; in nine cases the findings--including rectal stricture, granularity of the mucosa, and thickened rectal folds-were nonspecific. In six cases the study was normal. All patients had a long history of defecation disorders, and defecography was performed in all. In seven cases, intussusception of the rectal wall was seen; in another case the intussusception was accompanied by a rectocele. One case showed rectal prolapse. In four cases, failed relaxation of the puborectalis occurred and prevented the passage of the bolus; in another case there was abnormal perineal descent. In two patients studies were normal. In patients with defecation disorders, the possibility of this syndrome should be considered. Defecography is the method of choice for establishing the diagnosis. 相似文献