全文获取类型
收费全文 | 1654614篇 |
免费 | 127249篇 |
国内免费 | 3682篇 |
专业分类
耳鼻咽喉 | 22082篇 |
儿科学 | 55197篇 |
妇产科学 | 48010篇 |
基础医学 | 238400篇 |
口腔科学 | 43881篇 |
临床医学 | 147060篇 |
内科学 | 328669篇 |
皮肤病学 | 38519篇 |
神经病学 | 133838篇 |
特种医学 | 63202篇 |
外国民族医学 | 501篇 |
外科学 | 248911篇 |
综合类 | 38984篇 |
现状与发展 | 4篇 |
一般理论 | 622篇 |
预防医学 | 127309篇 |
眼科学 | 37358篇 |
药学 | 116528篇 |
1篇 | |
中国医学 | 3918篇 |
肿瘤学 | 92551篇 |
出版年
2021年 | 12660篇 |
2019年 | 13471篇 |
2018年 | 19398篇 |
2017年 | 14772篇 |
2016年 | 16718篇 |
2015年 | 18699篇 |
2014年 | 26191篇 |
2013年 | 39267篇 |
2012年 | 52633篇 |
2011年 | 55610篇 |
2010年 | 33155篇 |
2009年 | 31471篇 |
2008年 | 51281篇 |
2007年 | 54544篇 |
2006年 | 54965篇 |
2005年 | 53246篇 |
2004年 | 50927篇 |
2003年 | 48528篇 |
2002年 | 46662篇 |
2001年 | 83047篇 |
2000年 | 84902篇 |
1999年 | 70302篇 |
1998年 | 19523篇 |
1997年 | 17710篇 |
1996年 | 17701篇 |
1995年 | 16824篇 |
1994年 | 15309篇 |
1993年 | 14376篇 |
1992年 | 52505篇 |
1991年 | 50404篇 |
1990年 | 48409篇 |
1989年 | 46344篇 |
1988年 | 42305篇 |
1987年 | 41281篇 |
1986年 | 38512篇 |
1985年 | 36842篇 |
1984年 | 27884篇 |
1983年 | 23492篇 |
1982年 | 14316篇 |
1981年 | 12535篇 |
1979年 | 24576篇 |
1978年 | 17402篇 |
1977年 | 14507篇 |
1976年 | 13564篇 |
1975年 | 14138篇 |
1974年 | 16990篇 |
1973年 | 16494篇 |
1972年 | 15431篇 |
1971年 | 14075篇 |
1970年 | 13452篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
Christopher N. Cooley Tyler J. Beranek Matthew A. Warpinski Robert Alexander Amanda O. Esquivel 《The American journal of emergency medicine》2019,37(2):199-203
Introduction
In the United States there has been a large increase in participation in lacrosse for both males and females. The purpose of this study was to analyze the number of head injuries, injury rates (calculated using the reported number of participants) and types of head injuries that are seen in emergency departments in the United States.Methods
We compared injuries between male and female lacrosse participants. This was a retrospective study using a publicly available database produced by the US Consumer Product Safety Commission and information about lacrosse participation from US Lacrosse.Results
A linear regression was performed and showed a positive correlation between number of head injuries to males and time from 2002 to 2010 (R2?=?0.823; p?=?0.001). While the number of injuries to the head in female lacrosse participants was not significant. There was a negative correlation between the number of head injuries to males from 2010 to 2016 (R2?=?0.800; p?=?0.007), but again, there was no significance for female injury count (R2?=?0.417; p?=?0.117). Other significant differences between head injuries in males and females included the mechanism of injury and the type of injury recorded.Conclusion
The most recent data from 2010 to 2016, suggest that both males and females have had a decrease in injury rate. However the total number of female head injuries is not significantly decreasing and as the sport continues to grow there will likely be more total head injuries and visits to the emergency department. 相似文献12.
13.
Chronic transplant dysfunction is a complex dynamic pathogenic process. Clinically, a decrease in glomerular filtration rate (GFR) becomes apparent leading to chronic renal insufficiency and dialysis or death from cardiovascular events. Chronic transplant dysfunction can develop into a chronic alIograft nephropathy (CAN) as a specific entity with dynamic progression. CAN includes a collection of immunologic and non-immunologic factors, rejection, ischemia time, donor and recipient characteristics and toxicity of calcineurin inhibitors. Despite improvements in immunosuppression, the long-range prognosis of renal allografts has not improved. Whether modern immunosuppressive concepts with reduction or avoidance of calcineurin inhibitors and a therapy based on antimetabolites, such as mycophenolate or mTOR-inhibitors could lead to a prolongation of transplant survival, remains to be seen. 相似文献
14.
15.
A Kotsiou M Tsamouri S Anagnostopoulou M Tzivras E Vairactaris C Tesseromatis 《European journal of drug metabolism and pharmacokinetics》2006,31(2):97-101
Liver disease alters the pharmacokinetic and pharmacodynamic properties of hepatically eliminated drugs. The main factors influenced are plasma albumin levels, enzyme balance (induction & inhibition) and drug binding to tissue proteins. The influence of lidocaine on serum, heart and liver propranolol levels in Wistar rats after liver injury induced by carbon tetrachloride CCl4 0.4 ml/kg x 2/wkl, was investigated. 40 male Wistar rats were divided into four groups (I, II, III, IV; n=10), Group I animals received only propranolol (labelled + cold substance) 40 mg/kg/12 h p.o., group II propranolol plus lidocaine in a single dose of 4mg/kg s.c., group III was treated with CCl4 for 6 weeks and received propranolol x2 at the same dosage as group I, while group VI was treated with CCl4 and the same drug dosage as group II. The simultaneous administration of H3-propranolol and lidocaine increased propranolol levels in the serum and tissues. The liver in damaged animals showed an increase of propranolol level under lidocaine co-administration, probably due to CCl4 induced liver enzyme activity, resulting in a rapid propranolol metabolism or to competition between both drug protein binding sites. The increased propranolol levels in the heart after lidocaine administration were probably due to attributed to its high affinity for heart tissue. Consequently, as regards the therapeutic approach for patients with liver disease receiving propranolol their propranolol dosage should be reduced when lidocaine is co-administered. 相似文献
16.
T C Friedman 《Experimental and clinical endocrinology & diabetes》2006,114(7):356-360
The overnight one-mg dexamethasone suppression test has been used for many years to screen for Cushing's syndrome. This test has usually been evaluated in controls versus patients with severe hypercortisolism. Under these conditions, the overnight dexamethasone suppression test has been reported to have high sensitivity and specificity. The objective of this study was to determine the sensitivity of the one mg overnight dexamethasone suppression test in patients with mild and/or periodic Cushing's syndrome. Therefore, an overnight dexamethasone suppression test was performed in 17 consecutive patients presenting to an endocrinology clinic with signs and symptoms of hypercortisolemia who were later proven to have Cushing's syndrome. The majority of patients were found to have both mild and periodic hypercortisolism. One mg of dexamethasone was given at midnight and a plasma cortisol was measured by radioimmunoassay at 08:00 the following morning. Using a cut-off for a morning cortisol following overnight dexamethasone of > 5 microg/dL, only three of 17 patients failed to suppress to a value less than this cut-off (sensitivity 18 %). A cut-off of > 2 microg/dL gave similar sensitivity. Even with a stringent cut-off point of > 1.8 microg/dL, only seven of 17 patients failed to suppress to a value less than this cut-off point (sensitivity of 41 %). These results demonstrate that the great majority of patients with mild and/or periodic Cushing's syndrome suppress to overnight dexamethasone. Since patients with mild and/or periodic Cushing's syndrome are the patients in whom the identification of hypercortisolism is difficult, our results from this relatively small study suggest that this test should no longer be used to exclude these patients from further workup for Cushing's syndrome. 相似文献
17.
18.
19.
20.