全文获取类型
收费全文 | 9387篇 |
免费 | 563篇 |
国内免费 | 41篇 |
专业分类
耳鼻咽喉 | 90篇 |
儿科学 | 209篇 |
妇产科学 | 258篇 |
基础医学 | 1309篇 |
口腔科学 | 198篇 |
临床医学 | 971篇 |
内科学 | 2143篇 |
皮肤病学 | 134篇 |
神经病学 | 767篇 |
特种医学 | 298篇 |
外科学 | 1219篇 |
综合类 | 116篇 |
一般理论 | 13篇 |
预防医学 | 737篇 |
眼科学 | 177篇 |
药学 | 698篇 |
中国医学 | 5篇 |
肿瘤学 | 649篇 |
出版年
2023年 | 55篇 |
2022年 | 78篇 |
2021年 | 168篇 |
2020年 | 137篇 |
2019年 | 157篇 |
2018年 | 173篇 |
2017年 | 137篇 |
2016年 | 118篇 |
2015年 | 211篇 |
2014年 | 265篇 |
2013年 | 427篇 |
2012年 | 673篇 |
2011年 | 688篇 |
2010年 | 363篇 |
2009年 | 316篇 |
2008年 | 597篇 |
2007年 | 662篇 |
2006年 | 655篇 |
2005年 | 624篇 |
2004年 | 598篇 |
2003年 | 544篇 |
2002年 | 580篇 |
2001年 | 114篇 |
2000年 | 98篇 |
1999年 | 133篇 |
1998年 | 115篇 |
1997年 | 99篇 |
1996年 | 89篇 |
1995年 | 94篇 |
1994年 | 74篇 |
1993年 | 67篇 |
1992年 | 71篇 |
1991年 | 78篇 |
1990年 | 56篇 |
1989年 | 45篇 |
1988年 | 43篇 |
1987年 | 39篇 |
1986年 | 48篇 |
1985年 | 36篇 |
1984年 | 40篇 |
1983年 | 29篇 |
1982年 | 59篇 |
1981年 | 30篇 |
1980年 | 30篇 |
1979年 | 36篇 |
1978年 | 27篇 |
1977年 | 34篇 |
1976年 | 17篇 |
1975年 | 25篇 |
1973年 | 22篇 |
排序方式: 共有9991条查询结果,搜索用时 15 毫秒
11.
12.
13.
Stomach rupture can occur as a consequence of the expansion of compressed air during rapid ascent after diving. We present
the case of a middle-aged woman who suffered a gastric tear from surfacing too quickly after diving, and discuss the diagnosis
and management of such patients by reviewing previously reported similar events. Gastric barotrauma should be suspected in
divers who complain of abdominal pain, even in the absence of frank signs of peritoneal irritation. Although pneumoperitoneum
is always present in these patients, it can also occur as a consequence of pulmonary barotrauma, making gastroscopy or radiological
contrast studies, or both, essential for a definitive diagnosis. Surgical repair represents the treatment of choice for an
active full-thickness tear and, if associated with arterial gas embolism or decompression sickness, should ideally be performed
in a center where a category I (intensive care-capable) hyperbaric unit is available.
Received: March 18, 2002 / Accepted: September 3, 2002
Reprint requests to: L.V. Titu 相似文献
14.
Michael B. Farnell Gerard V. Aranha Yuji Nimura Fabrizio Michelassi 《Journal of gastrointestinal surgery》2008,12(4):651-656
With improvements in the safety of Whipple resection in recent decades, surgeons have continued to explore the role of more
extensive lymphadenectomy in hope of improving long-term survival. A systematic literature search of level I evidence addressing
the role of the extent of lymphadenectomy was undertaken. Only reports of prospective, randomized controlled trials comparing
pancreaticoduodenectomy with standard lymphadenectomy to pancreaticoduodenectomy with extended lymphadenectomy where information
regarding survival, morbidity, mortality, the number of resected lymph nodes in each group and detailed operative technique
were included. Four prospective, randomized trials comprising some 424 patients and one meta-analysis were identified. In
aggregate, these studies confirmed that the number of resected lymph nodes was significantly higher in the pancreaticoduodenectomy
with extended lymphadenectomy group. Morbidity and mortality rates were comparable. Postoperative diarrhea in the early months
after operation was problematic in patients undergoing extended lymphadenectomy. In none of the studies was a benefit in long-term
survival demonstrated. Standard pancreaticoduodenectomy continues to be the operation of choice for adenocarcinoma of the
head of the pancreas.
Presented at The Society for Surgery of the Alimentary Tract Postgraduate Course “Systematic Reviews of Pancreaticobiliary
Disease Customized for the Gastroenterologist and Gastrointestinal Surgeon” on May 20, 2007, Washington, D.C. 相似文献
15.
16.
17.
18.
Gerard A. Riley 《Journal of developmental and physical disabilities》1998,10(2):153-165
The use of stimulus modifications in teaching involves altering the materials of a task in order to simplify its execution. Though their use in teaching stimulus discriminations to people with developmental disabilities has been extensively investigated, less attention has been given to their utilization in teaching response topography. This paper offers some general guidelines about their use for this purpose. In relation to their design, it is suggested that the aim should be to reduce the demands made by task components, to eliminate components, and/or to increase the attentional value of the discriminating features of the response topography. In relation to their application, guidelines are suggested about when they should be employed in conjunction with response prompts; when they should be used, either alone or in conjunction with response prompts, in preference to response prompts alone; whether one or a series of modifications is required; and at what point during teaching should probe trials on the unmodified task be introduced. 相似文献
19.
Insulin like growth factor I is an autocrine regulator of human colon cancer cell differentiation and growth. 总被引:4,自引:0,他引:4
The polyanionic compound suramin triggers enterocyte-like differentiation of the human colic adenocarcinoma cell clone HT29-D4. We now demonstrate that suramin interferes with the binding of IGF-I to its receptor at the surface of HT29-D4 cells. Half-maximum inhibition of 125I-IGF-I binding was obtained in the presence of 25 micrograms/ml suramin. Moreover, the drug was able to dissociate 125I-IGF previously bound to its cell surface receptor. Affinity labeling HT29-D4 cells were cultured in the presence of 10 micrograms/ml of alpha-IR3, a monoclonal antibody directed against the binding site of IGF-I, an inhibition of cell proliferation and a stimulation of cell differentiation was observed. After 10 days of treatment with alpha-IR3, HT29-D4 cells formed a regular monolayer of enterocyte-like cells exhibiting an apical brush border and tight junctions delimiting two domains of the plasma membrane (apical and basolateral). Furthermore, we show that IGF-I significantly increased the initial rate of glucose uptake by HT29-D4 cells, while we have previously shown that suramin decreased glucose consumption. From these data we conclude that IGF-I secreted by the cells themselves, stimulates proliferation of HT29-D4 cells via an autocrine mechanism. Blockade of this stimulation by suramin or by a specific monoclonal antibody inhibits cell growth, glucose uptake and triggers the process of enterocytic differentiation. 相似文献
20.
Georges Dellatolas Lucia Willadino Braga Ligia do Nascimento Souza Gilberto Nunes Filho Elizabeth Queiroz Gerard Deloche 《Journal of the International Neuropsychological Society》2003,9(5):771-782
The effect of the degree of illiteracy (complete or incomplete) on phonological skills, verbal and visual memory and visuospatial skills is examined in 97 normal Brazilian adults who considered themselves illiterate, and 41 Brazilian school children aged 7 to 8 years, either nonreaders or beginning readers. Similar literacy effects were observed in children and in adults. Tasks involving phonological awareness and visual recognition memory of nonsense figures distinguish the best nonreaders and beginning readers. Children performed better than adults at oral repetition of short items and figure recall, and adults better than children at semantic verbal fluency, digit span, and word list recall. A principal component analysis of the correlations between tasks showed that phonological awareness/reading, phonological memory/oral repetition, and semantic verbal memory/fluency tasks, generated different components. The respective role of culturally based preschool activities and literacy on the cognitive functions that are explored in this study is discussed. 相似文献