全文获取类型
收费全文 | 18671篇 |
免费 | 1582篇 |
国内免费 | 67篇 |
专业分类
耳鼻咽喉 | 326篇 |
儿科学 | 518篇 |
妇产科学 | 448篇 |
基础医学 | 2581篇 |
口腔科学 | 305篇 |
临床医学 | 2309篇 |
内科学 | 3536篇 |
皮肤病学 | 420篇 |
神经病学 | 1952篇 |
特种医学 | 725篇 |
外国民族医学 | 1篇 |
外科学 | 2548篇 |
综合类 | 281篇 |
一般理论 | 16篇 |
预防医学 | 1627篇 |
眼科学 | 382篇 |
药学 | 1167篇 |
中国医学 | 26篇 |
肿瘤学 | 1152篇 |
出版年
2023年 | 100篇 |
2022年 | 167篇 |
2021年 | 357篇 |
2020年 | 243篇 |
2019年 | 330篇 |
2018年 | 436篇 |
2017年 | 330篇 |
2016年 | 376篇 |
2015年 | 432篇 |
2014年 | 571篇 |
2013年 | 838篇 |
2012年 | 1138篇 |
2011年 | 1102篇 |
2010年 | 646篇 |
2009年 | 591篇 |
2008年 | 988篇 |
2007年 | 1019篇 |
2006年 | 977篇 |
2005年 | 943篇 |
2004年 | 853篇 |
2003年 | 775篇 |
2002年 | 757篇 |
2001年 | 397篇 |
2000年 | 382篇 |
1999年 | 369篇 |
1998年 | 180篇 |
1997年 | 173篇 |
1996年 | 124篇 |
1995年 | 131篇 |
1994年 | 135篇 |
1993年 | 118篇 |
1992年 | 261篇 |
1991年 | 258篇 |
1990年 | 248篇 |
1989年 | 205篇 |
1988年 | 236篇 |
1987年 | 235篇 |
1986年 | 236篇 |
1985年 | 201篇 |
1984年 | 183篇 |
1983年 | 177篇 |
1982年 | 132篇 |
1981年 | 128篇 |
1980年 | 108篇 |
1979年 | 185篇 |
1978年 | 131篇 |
1977年 | 107篇 |
1976年 | 130篇 |
1975年 | 125篇 |
1974年 | 130篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
941.
Down's syndrome and diabetes 总被引:2,自引:0,他引:2
942.
The total number of outpatient visits to 10 hospital emergency rooms declined 64 per cent and emergency admissions 35 per cent immediately after the February 1978 blizzard in Rhode Island; both quickly returned to normal levels. Three days after the storm, admissions for myocardial infarction increased markedly. Total mortality and ischemic heart disease deaths showed a considerable increase for the five-day period following the blizzard. The physical and psychological stress of the blizzard probably precipitated cardiac deaths in susceptible individuals. 相似文献
943.
944.
945.
946.
Reinvestigation of the conversion of folic acid to leucovorin [L-(+/-)-5-CHO-THF] led to improved methods for the synthesis of this drug, which is suitable for clinical use. Also, methods were developed for the chromatographic and nonchromatographic purification of less pure samples of L-(+/-)-5-CHO-THF. 相似文献
947.
948.
949.
950.
G J Avery H M Spotnitz E A Rose J R Malm B F Hoffman 《The Journal of thoracic and cardiovascular surgery》1979,77(2):267-276
Hemodynamic effects of isoproterenol, dopamine, and epinephrine were studied before and after acute beta-adrenergic blockade in 16 open-chest, anesthetized mongrel dogs. Beta blockade was induced with 1 mg. per kilogram of intravenous propranolol. Cardiac output measurements were obtained by thermal dilution, and pressure recordings were obtained in the right ventricle, pulmonary artery, left atrium, left ventricle, and aorta. Derived parameters included stroke volume, pulmonary and systemic vascular resistances, and peak left ventricular dP/dt. In the presence of propranolol, epinephrine became a lethal drug in large doses and did not increase cardiac output in standard doses. Dopamine, in 25 to 50 mcg. per kilogram per minute doses, increased arterial pressure and systemic resistance; cardiac output was diminished compared with dopamine, 10 mcg. per kilogram per minute, prior to propranolol, as a result of increased resistance and decreased LV contractility. Isoproterenol, 0.6 to 0.9 mcg. per kilogram per minute, 15 to 20 times standard dosages, had moderately positive inotropic effects and increased cardiac output. Left ventricular systolic pressure with isoproterenol after propranolol was reduced when compared with effects of smaller doses prior to propranolol. These observations suggest that none of the catecholamines studied would be optimal for circulatory support in heart failure in the presence of propranolol. The present results define a pharmacologic basis for design of appropriate drug combinations for circulatory support in beta-blocked animals. 相似文献