全文获取类型
收费全文 | 2748篇 |
免费 | 155篇 |
国内免费 | 77篇 |
专业分类
耳鼻咽喉 | 9篇 |
儿科学 | 173篇 |
妇产科学 | 28篇 |
基础医学 | 299篇 |
口腔科学 | 63篇 |
临床医学 | 326篇 |
内科学 | 676篇 |
皮肤病学 | 82篇 |
神经病学 | 129篇 |
特种医学 | 409篇 |
外科学 | 246篇 |
综合类 | 68篇 |
预防医学 | 119篇 |
眼科学 | 19篇 |
药学 | 140篇 |
2篇 | |
肿瘤学 | 192篇 |
出版年
2021年 | 17篇 |
2020年 | 16篇 |
2019年 | 19篇 |
2018年 | 42篇 |
2017年 | 26篇 |
2016年 | 25篇 |
2015年 | 47篇 |
2014年 | 53篇 |
2013年 | 69篇 |
2012年 | 51篇 |
2011年 | 59篇 |
2010年 | 95篇 |
2009年 | 101篇 |
2008年 | 77篇 |
2007年 | 108篇 |
2006年 | 79篇 |
2005年 | 79篇 |
2004年 | 47篇 |
2003年 | 37篇 |
2002年 | 48篇 |
2001年 | 70篇 |
2000年 | 64篇 |
1999年 | 67篇 |
1998年 | 133篇 |
1997年 | 159篇 |
1996年 | 135篇 |
1995年 | 112篇 |
1994年 | 116篇 |
1993年 | 103篇 |
1992年 | 53篇 |
1991年 | 61篇 |
1990年 | 62篇 |
1989年 | 71篇 |
1988年 | 68篇 |
1987年 | 66篇 |
1986年 | 79篇 |
1985年 | 68篇 |
1984年 | 53篇 |
1983年 | 27篇 |
1982年 | 28篇 |
1981年 | 39篇 |
1980年 | 30篇 |
1979年 | 24篇 |
1978年 | 16篇 |
1977年 | 28篇 |
1976年 | 29篇 |
1975年 | 31篇 |
1974年 | 12篇 |
1972年 | 11篇 |
1970年 | 11篇 |
排序方式: 共有2980条查询结果,搜索用时 734 毫秒
11.
12.
13.
14.
15.
16.
Directly measured tissue oxygen tension and arterial oxygen tension assess tissue perfusion 总被引:8,自引:0,他引:8
Mean subcutaneous tissue PO2 (PsqO2) measurements were obtained in dogs with an unheated electrode placed in an implanted Silastic tonometer, while PaO2 was increased in increments from 40 to 600 torr during normal, increased, and reduced blood volume. These changes reflect that the mean PsqO2 is approximately 10 torr below the PO2 of venous blood draining that tissue. Since PaO2 was already known, the oxygen content of arterial and venous blood entering and leaving this tissue could be determined by reference to blood-oxygen dissociation curves. Therefore, relative changes in blood flow could be calculated using the Fick principle. After a 20% blood loss, the PsqO2 measured during breathing of room air fell to 20% of baseline, corresponding to an 80% fall in sc blood flow; it remained low until the shed blood was returned despite compensatory changes in cardiac output. Rapid infusion of electrolyte solutions in normovolemic animals produced a temporary increase in local blood flow. Subcutaneous oximetry seems capable of quantifying peripheral perfusion and may be clinically useful. 相似文献
17.
Ralls PW; Johnson MB; Kanel G; Dobalian DM; Colletti PM; Boswell WD Jr; Radin DR; Halls JM 《Radiology》1986,161(2):451-454
FM sonography - a signal-processing technique that uses frequency and phase information as well as amplitude data - shows promise in evaluation of patients with diffuse liver disease. In a prospective blinded review of 37 patients with biopsy-proved liver disease and 42 healthy volunteers, FM sonography was clearly superior to traditional amplitude-based (AM) sonography in distinguishing healthy from diseased subjects. Statistically significant differences were seen in accuracy (FM, 98.7%; AM, 84.8%), sensitivity (FM, 97.3%; AM, 70.3%), and negative predictive value (FM, 97.7%; AM, 78.8%). Our data also suggest that current FM sonographic techniques cannot differentiate among histologic findings associated with different hepatic parenchymal abnormalities. It is unclear, therefore, whether FM imaging can reduce the numbers of patients who require biopsy for diagnosis or the frequency of biopsy procedures in patients with known disease. 相似文献
18.
Pernes JM; Vitoux JF; Brenoit P; Raynaud A; Parola JL; Roth JP; Angel CY; Fiessinger JN; Roncato M; Gaux JC 《Radiology》1986,158(2):481-485
Thirty-five patients hospitalized for recent angiographically documented arterial occlusion in the legs (27 femoropopliteal arteries and eight grafts) benefited from local fibrinolytic therapy delivered at the site of the occlusion with a 4- or 5-F catheter. This therapy combined a continuous urokinase (UK) infusion of 1,000 U/kg/hour and a lysyl plasminogen (LYS-PLG) infusion of 15 microkatals every 30 minutes. Angiographically confirmed lysis was obtained in 85% of the cases. Only 3% of the patients had major and 6% had minor groin hematomas. Only two patients had concentrations of fibrinogen as low as 100 mg/dl. Intravascular infusion of UK-LYS-PLG is as effective as streptokinase. Its excellent tolerance makes it a good alternative in the treatment of acute ischemia in the lower limbs. 相似文献
19.
20.