全文获取类型
收费全文 | 670篇 |
免费 | 56篇 |
国内免费 | 6篇 |
专业分类
耳鼻咽喉 | 9篇 |
儿科学 | 36篇 |
妇产科学 | 19篇 |
基础医学 | 84篇 |
口腔科学 | 16篇 |
临床医学 | 88篇 |
内科学 | 137篇 |
皮肤病学 | 33篇 |
神经病学 | 17篇 |
特种医学 | 126篇 |
外科学 | 50篇 |
综合类 | 26篇 |
预防医学 | 25篇 |
眼科学 | 17篇 |
药学 | 21篇 |
1篇 | |
肿瘤学 | 27篇 |
出版年
2023年 | 2篇 |
2022年 | 3篇 |
2021年 | 3篇 |
2020年 | 4篇 |
2019年 | 8篇 |
2018年 | 10篇 |
2017年 | 3篇 |
2016年 | 11篇 |
2015年 | 12篇 |
2014年 | 17篇 |
2013年 | 19篇 |
2012年 | 7篇 |
2011年 | 17篇 |
2010年 | 32篇 |
2009年 | 32篇 |
2008年 | 14篇 |
2007年 | 25篇 |
2006年 | 24篇 |
2005年 | 21篇 |
2004年 | 10篇 |
2003年 | 9篇 |
2002年 | 12篇 |
2001年 | 9篇 |
2000年 | 8篇 |
1999年 | 7篇 |
1998年 | 38篇 |
1997年 | 48篇 |
1996年 | 38篇 |
1995年 | 19篇 |
1994年 | 33篇 |
1993年 | 24篇 |
1992年 | 15篇 |
1991年 | 12篇 |
1990年 | 17篇 |
1989年 | 26篇 |
1988年 | 26篇 |
1987年 | 13篇 |
1986年 | 14篇 |
1985年 | 11篇 |
1984年 | 16篇 |
1983年 | 14篇 |
1982年 | 12篇 |
1981年 | 12篇 |
1980年 | 7篇 |
1978年 | 4篇 |
1977年 | 2篇 |
1976年 | 4篇 |
1975年 | 2篇 |
1967年 | 1篇 |
1963年 | 1篇 |
排序方式: 共有732条查询结果,搜索用时 0 毫秒
91.
Hepatocellular carcinoma: assessment of resectability by computed tomography and ultrasound 总被引:2,自引:0,他引:2
A retrospective review of the CT and ultrasound scans from examinations of 30 patients who had hepatocellular carcinoma (hepatoma) was undertaken with special emphasis placed on evaluation of hepatic distribution of tumor, vascular invasion, and extrahepatic spread. Although both CT and ultrasound detected hepatoma in 29 of 30 patients (96%), CT showed more extensive hepatic parenchymal involvement in eight of the patients. Vascular invasion was seen more frequently with ultrasound than with CT. Invasion into the main portal vein was seen by ultrasound in 11 of 30 patients (37%). Extrahepatic spread of tumor was much more frequently detected by CT and was present in 21 of 30 patients (70%). A reasoned approach to the diagnostic workup of hepatomas that will minimize invasive procedures and unnecessary surgery is presented. 相似文献
92.
93.
94.
Teaching radiographic anatomy to pre-clinical medical students is important as it relates anatomical studies to clinical medicine and the same time prepares them for the radiology they will encounter in their clinical years. A programme is described in which radiographic anatomy is comprehensively covered without proving too great a commitment to clinical radiologists. The programmes consist of exhibits of X-rays in the dissecting room, slide-lecture demonstrations and a permanent museum of radiological anatomy. This programme has worked well and there has been a very favourable student response. 相似文献
95.
96.
97.
Sabine MP Verschueren Christophe Delecluse Albrecht L Claessens Patrick Haentjens Dirk Vanderschueren Steven Boonen 《Journal of bone and mineral research》2011,26(1):42-49
Sarcopenia and osteoporosis represent a growing public health problem. We studied the potential benefit of whole‐body vibration (WBV) training given a conventional or a high dose of daily vitamin D supplementation in improving strength, muscle mass, and bone density in postmenopausal women. In a 2 × 2 factorial‐design trial, 113 institutionalized elderly females aged over 70 years (mean age 79.6 years) were randomly assigned either to a WBV or a no‐training group, receiving either a conventional dose (880 IU/day) or a high dose (1600 IU/day) of vitamin D3. The primary aim was to determine the effects of 6 months of WBV and/or vitamin D supplementation on isometric and dynamic strength, leg muscle mass, and hip bone mineral density (BMD). Additionally, the increase in 25‐hydroxyvitamin D [25(OH)D] levels between conventional and high‐dose supplementation was compared. After 6 months of treatment, dynamic muscle strength, hip BMD, and vitamin D serum levels improved significantly in all groups, whereas isometric strength and muscle mass did not change. When compared with no training, the WBV program did not result in additional improvements. When compared with 880 IU, a high dose of 1600 IU of vitamin D did result in higher serum vitamin D levels but did not result in additional improvements. In institutionalized women older than 70 years, the WBV training protocol tested is not more efficient in enhancing muscle mass, strength, and hip BMD compared with vitamin D supplementation. A higher dose of 1600 IU of vitamin D does not provide additional musculoskeletal benefit in this population compared with conventional doses. © 2011 American Society for Bone and Mineral Research. 相似文献
98.
99.
Busch MP; Laycock M; Kleinman SH; Wages JW Jr; Calabro M; Kaplan JE; Khabbaz RF; Hollingsworth CG 《Blood》1994,83(4):1143-1148
Blood donations in the United States have been screened for antibody to human T-lymphotropic virus type I (HTLV-I) by HTLV-I enzyme immunoassay (EIA) since November 1988. Specimens repeatedly found to be reactive by EIA undergo confirmation by supplementary serologic tests. We assessed the accuracy of blood center testing of 994 HTLV-I EIA repeat-reactive specimens in five US blood centers between November 1988 and December 1991. Of 410 confirmed HTLV-I/II donations, 407 (99.3%) were infected with HTLV-I/II, as determined by polymerase chain reaction (PCR) (403 cases) and by repeat serologic testing (4 cases). The three false- positive results occurred in the first year of testing. Of 425 HTLV- indeterminate specimens, 6 (1.4%) were found to be infected by PCR (5 with HTLV-II and 1 with HTLV-I). None of 159 confirmatory test-negative donations was PCR positive. Of HTLV-I/II-seropositive specimens, 80.2% to 95.4% could be typed as HTLV-I or HTLV-II by type-specific serologic assays. These results support recommendations that HTLV-I/II- seropositive donors should be advised that they are infected with HTLV- I, HTLV-II, or HTLV-I/II (depending on results of type-specific assays). HTLV-indeterminate donors should be advised that their results only rarely indicate HTLV infection. HTLV confirmatory test-negative donors should be reassured that they are not infected with HTLV-I or HTLV-II. 相似文献
100.
Initiation of the extrinsic pathway of coagulation by human and rabbit alveolar macrophages: a kinetic study 总被引:3,自引:0,他引:3
We examined assembly and expression of the factor X activating complex on human and rabbit alveolar macrophages. Kinetic parameters of the factor X activating reaction were determined by functional titrations of factors VII and X with macrophage tissue factor (TF) added. We found rapid activation of factor X to Xa on alveolar macrophage surfaces. Detection of rapid factor Xa formation on macrophages required addition of exogenous factors VII and X. At plasma concentrations of the purified factors, factor Xa was formed on freshly isolated macrophages at approximately 5.4 pmol/min/10(6) cells. After macrophage maturation in culture for 20 hours with LPS (endotoxin) added, the factor X activation rate was increased two- to sixfold. The km' (apparent km) of TF-factor VII enzymatic complexes assembled on alveolar macrophages for factor X were (258 +/- 55 and 475 +/- 264 nmol/L for human and rabbit cells, respectively). The km' did not change during macrophage maturation in culture, but V'max (apparent Vmax) was consistently increased. The K1/2 of human factor VII (concentrations giving half maximal rates of factor X activation) for the interaction with human and rabbit alveolar macrophage TF were 0.191 +/- 0.096 and 1.7 +/- 0.7 etamol/L, respectively. The K1/2 were not significantly changed after maturation, whereas rates of Xa formation at saturation with factor VII were increased. The fast rates of factor X activation observed at physiologic concentrations of plasma-derived factors VII and X indicate that TF on alveolar macrophages is likely to provide sites for binding of factor VII and activation of factor X in vivo during clotting reactions associated with alveolar edema and inflammation. 相似文献