全文获取类型
收费全文 | 4368篇 |
免费 | 397篇 |
国内免费 | 17篇 |
专业分类
耳鼻咽喉 | 53篇 |
儿科学 | 134篇 |
妇产科学 | 98篇 |
基础医学 | 615篇 |
口腔科学 | 79篇 |
临床医学 | 363篇 |
内科学 | 965篇 |
皮肤病学 | 185篇 |
神经病学 | 420篇 |
特种医学 | 94篇 |
外科学 | 765篇 |
综合类 | 17篇 |
预防医学 | 397篇 |
眼科学 | 60篇 |
药学 | 255篇 |
中国医学 | 5篇 |
肿瘤学 | 277篇 |
出版年
2023年 | 36篇 |
2022年 | 44篇 |
2021年 | 131篇 |
2020年 | 68篇 |
2019年 | 120篇 |
2018年 | 142篇 |
2017年 | 98篇 |
2016年 | 95篇 |
2015年 | 111篇 |
2014年 | 163篇 |
2013年 | 193篇 |
2012年 | 271篇 |
2011年 | 268篇 |
2010年 | 137篇 |
2009年 | 134篇 |
2008年 | 203篇 |
2007年 | 214篇 |
2006年 | 197篇 |
2005年 | 214篇 |
2004年 | 180篇 |
2003年 | 187篇 |
2002年 | 163篇 |
2001年 | 134篇 |
2000年 | 131篇 |
1999年 | 108篇 |
1998年 | 45篇 |
1997年 | 37篇 |
1996年 | 30篇 |
1995年 | 29篇 |
1994年 | 40篇 |
1993年 | 29篇 |
1992年 | 79篇 |
1991年 | 89篇 |
1990年 | 75篇 |
1989年 | 67篇 |
1988年 | 66篇 |
1987年 | 65篇 |
1986年 | 55篇 |
1985年 | 54篇 |
1984年 | 39篇 |
1983年 | 32篇 |
1982年 | 19篇 |
1981年 | 21篇 |
1979年 | 22篇 |
1978年 | 17篇 |
1977年 | 16篇 |
1976年 | 12篇 |
1975年 | 13篇 |
1973年 | 11篇 |
1972年 | 17篇 |
排序方式: 共有4782条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
5.
6.
The effects of sulfated cholecystokinin (CCK-8S) and glucose on insulin secretion and polyphosphoinositide (PPI) metabolism were studied in isolated rat islets. Both agonists stimulate PPI hydrolysis, inositol phosphate accumulation, 3H efflux from [3H]inositol-prelabeled tissue, and 45Ca efflux from prelabeled cells. However, the effects of CCK-8S on PPI metabolism are considerably greater than those of glucose. Furthermore, the effects of CCK-8S on PPI and Ca2+ metabolism are observed whether islets are incubated in either 2.75 or 7 mM glucose, but CCK-8S only stimulates insulin secretion (a biphasic response) when the higher glucose concentration is present. Addition of 1 microM forskolin to islets incubated in media containing 2.75 mM glucose does not influence basal insulin secretion but sensitizes the islets to the action of CCK-8S. In the presence of forskolin, CCK-8S induces a very marked first phase but no second phase of insulin secretion. We postulate that CCK-8S acts in this tissue via receptor-linked PPI hydrolysis, leading to an inositol trisphosphate-induced Ca2+ efflux. These receptor-mediated effects of CCK-8S are not altered either by the ambient glucose concentration or the cAMP content of the islets, but these two factors determine the responsiveness of the islets (in terms of insulin secretion) to a given CCK-8S signal. 相似文献
7.
E Moreno González I Landa Garcia J Calleja Kempin M Gomez Gutierrez J Arias Diaz D Riano Carrera F Parez Cerda P Moral Gutierrez F Guillen Ramirez I Garcia Garcia 《Der Chirurg》1990,61(10):701-704
Between 4/1986 to 1/1989, 74 orthotopic liver transplantation were performed in 62 patients (62 first liver transplants, 10 as second graft and two as a third graft); 57 in adults and 17 in children. The main indication for the operation was liver cirrhosis (61.4%) (the most frequent etiology was alcoholic cirrhosis, 28.5%). Six cirrhotic patients had a hepatocarcinoma (9.6%). Two received a liver and kidney transplant due to terminal renal insufficiency and hemodialysis. The most frequent indication in children was biliary atresia (33.3%). Six patients had a fulminal liver failure (9.6%). AB0 blood group compatibility was identical in 87.5%, compatible in six and incompatible in three patients. Total orthotopic liver transplantation was performed in 67 patients, and size-reduced liver was indicated in 7 patients. Extracorporeal veno-venous bypass was used in adults but never in children. In 93.1% of the transplants a single hepatic artery was anastomosed to the recipient and in 6.9% a double anastomosis was performed. In 62.5% of the patients a end-to-end choledocho-choledochostomy was performed and in 34.8% hepatico-jejunostomy was indicated. Three months postoperative mortality rate was 12.9%. Arterial stenosis and thrombosis were the most frequent complication. 相似文献
8.
9.
10.
Abstract: Spontaneous intracranial hypotension (SIH) is a postural headache syndrome unrelated to dural puncture. Because of the increasing failure of epidural blood patch (EBP) to relieve headache in SIH, we retrospectively investigated the epidemiological features and treatment outcomes in 55 cases of SIH. The study population was stratified by age and sex; continuous variables were compared for differences by t -tests; categorical variables were compared by Chi-squared analysis or Fisher exact tests. Significant differences were identified by P values of 0.05 or less. The mean age of the study population was 44 ± 12 years with a female to male ratio of 1.3:1.0. Men presented with subdural hematomas ( P = 0.001) more often than women. Meningeal enhancement on contrast magnetic resonance imaging (MRI) was the most consistent radiographic finding. Radionuclide cisternography (RC) demonstrated thoracolumbar dural leaks in 16 of 22 patients. EBP failures were more common in patients aged 40 and younger than in older patients ( P = 0.003). Postural headache from SIH was not uniformly responsive to EBP, and had significant comorbidities, especially in men. The management of postural headache in SIH by other techniques to restore brain position and cerebrospinal fluid dynamics should be investigated. 相似文献