全文获取类型
收费全文 | 998618篇 |
免费 | 75106篇 |
国内免费 | 2617篇 |
专业分类
耳鼻咽喉 | 12968篇 |
儿科学 | 34508篇 |
妇产科学 | 28468篇 |
基础医学 | 145500篇 |
口腔科学 | 27746篇 |
临床医学 | 90344篇 |
内科学 | 193725篇 |
皮肤病学 | 22944篇 |
神经病学 | 79199篇 |
特种医学 | 38399篇 |
外国民族医学 | 307篇 |
外科学 | 149619篇 |
综合类 | 23742篇 |
一般理论 | 385篇 |
预防医学 | 77863篇 |
眼科学 | 22612篇 |
药学 | 71987篇 |
3篇 | |
中国医学 | 2029篇 |
肿瘤学 | 53993篇 |
出版年
2018年 | 10575篇 |
2017年 | 8249篇 |
2016年 | 9388篇 |
2015年 | 10608篇 |
2014年 | 14447篇 |
2013年 | 22028篇 |
2012年 | 29024篇 |
2011年 | 30874篇 |
2010年 | 18520篇 |
2009年 | 17466篇 |
2008年 | 28826篇 |
2007年 | 30516篇 |
2006年 | 31000篇 |
2005年 | 29682篇 |
2004年 | 28973篇 |
2003年 | 27843篇 |
2002年 | 26847篇 |
2001年 | 46955篇 |
2000年 | 48066篇 |
1999年 | 40288篇 |
1998年 | 11182篇 |
1997年 | 10099篇 |
1996年 | 10163篇 |
1995年 | 9781篇 |
1994年 | 9094篇 |
1993年 | 8488篇 |
1992年 | 32261篇 |
1991年 | 31470篇 |
1990年 | 31017篇 |
1989年 | 29894篇 |
1988年 | 27188篇 |
1987年 | 27344篇 |
1986年 | 25455篇 |
1985年 | 24619篇 |
1984年 | 18402篇 |
1983年 | 15524篇 |
1982年 | 9292篇 |
1981年 | 8381篇 |
1979年 | 16864篇 |
1978年 | 12219篇 |
1977年 | 10320篇 |
1976年 | 9758篇 |
1975年 | 10180篇 |
1974年 | 12323篇 |
1973年 | 11844篇 |
1972年 | 10888篇 |
1971年 | 10114篇 |
1970年 | 9378篇 |
1969年 | 8724篇 |
1968年 | 8105篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
971.
972.
973.
974.
975.
976.
977.
978.
Urticaria is a common condition, seldom of allergic origin. It is however not always possible to find the provoking allergen. The aim of the present study was to analyze if there was a relationship between urticaria and sensitization to common airborne allergens. A representative sample of 402 12 to 13-yr-old children answered a questionnaire on allergic diseases, 397 were interviewed by the study nurse and 371 underwent skin prick tests to cat, dog, horse, birch, timothy-grass, house dust mites and Cladosporium mould. Specific IgE-antibodies were analyzed to birch pollen and cat dander. Urticaria was more common in sensitized children, but the relationship between urticaria and sensitization was only statistically significant for birch pollen sensitization (OR 1.99, 95% CL 1.04-3.83), when tested in a multiple logistic regression model with the specified allergens as independent variables. A similar pattern was seen for birch-specific IgE-antibody levels, which was higher in children reporting urticaria than in those without. IgE-levels to cat dander did not show such a difference. Urticaria was statistically significantly associated with sensitization to birch-pollen, but not to other common inhalant allergens. We propose that intake of birch-pollen cross-reactive food-stuffs may be a neglected cause of urticaria and relapsing urticaria, in birch-pollen sensitized subjects. 相似文献
979.
Iu A Popova L B Buravkova B N Pavlov 《Aviakosmicheskaia i ekologicheskaia meditsina》2005,39(5):31-36
Several metabolic and hormonal parameters were evaluated in blood of two human subjects during simulation of an extended saturation dive. Increases in creatine kinase and an upward trend in cholesterol and glucose were observed after decompression. The levels of TTH and thyroxin went up in both subjects during exposure. The significant changes in cortisol, ACTH, insulin and C-peptide were a fingerprint of stress-reaction. After eight days of recovery most of the parameters returned to baseline values. The investigation suggests that the recompression treatment table did not cause pathological changes in the biochemical and hormonal parameters of humans. 相似文献
980.
Peter B. Richman MD Shari Dominguez MD David Kasper MD Frederick Chen MD Jeremy Friese MD Joseph Wood MD JD Joseph Collins MD Jeffrey A. Kline MD 《Academic emergency medicine》2006,13(3):295-301
Objectives: To determine interobserver agreement between radiologists for computed tomography (CT) angiography and venography. CT venography of the lower extremities combined with standard CT angiography of the chest may result in an increased overall diagnosis rate of venous thromboembolism (pulmonary embolism or deep venous thrombosis).
Methods: The study had a retrospective cohort design. The population consisted of emergency department patients who were evaluated for suspected pulmonary embolism. A random sample of 50 patients diagnosed and treated for venous thromboembolism and 50 age- and gender-matched patients whose CT angiograms and venograms were read as negative were enrolled. The original reading (R1) was compared with readings of two study radiologists: R2, a general radiologist, and R3, a radiologist with fellowship training in cross-sectional imaging. All readers were blinded to each other.
Results: Both R2 and R3 found both CT angiogram and venogram components technically adequate in 95% (95% CI = 89% to 98%) and 86% (95% CI = 78% to 92%) of studies, respectively. The agreement was very good for CT angiography (lowest agreement = 92%; lowest κ = 0.83) and was good for CT venography (85%, κ = 0.65). In nine cases, R1 read the CT angiogram as negative but the venogram as positive for DVT, whereas both R2 and R3 read both components as negative in four of these nine, suggesting a false-positive isolated DVT rate of 44% (95% CI = 19% to 73%). In no case did R1 read both scan components as negative when R2 and R3 agreed on presence of pulmonary embolism or DVT.
Conclusions: Diagnosis of pulmonary embolism on CT angiography is more reliable than diagnosis of isolated DVT on CT venography. 相似文献
Methods: The study had a retrospective cohort design. The population consisted of emergency department patients who were evaluated for suspected pulmonary embolism. A random sample of 50 patients diagnosed and treated for venous thromboembolism and 50 age- and gender-matched patients whose CT angiograms and venograms were read as negative were enrolled. The original reading (R1) was compared with readings of two study radiologists: R2, a general radiologist, and R3, a radiologist with fellowship training in cross-sectional imaging. All readers were blinded to each other.
Results: Both R2 and R3 found both CT angiogram and venogram components technically adequate in 95% (95% CI = 89% to 98%) and 86% (95% CI = 78% to 92%) of studies, respectively. The agreement was very good for CT angiography (lowest agreement = 92%; lowest κ = 0.83) and was good for CT venography (85%, κ = 0.65). In nine cases, R1 read the CT angiogram as negative but the venogram as positive for DVT, whereas both R2 and R3 read both components as negative in four of these nine, suggesting a false-positive isolated DVT rate of 44% (95% CI = 19% to 73%). In no case did R1 read both scan components as negative when R2 and R3 agreed on presence of pulmonary embolism or DVT.
Conclusions: Diagnosis of pulmonary embolism on CT angiography is more reliable than diagnosis of isolated DVT on CT venography. 相似文献