全文获取类型
收费全文 | 2260篇 |
免费 | 133篇 |
国内免费 | 25篇 |
专业分类
耳鼻咽喉 | 11篇 |
儿科学 | 178篇 |
妇产科学 | 30篇 |
基础医学 | 220篇 |
口腔科学 | 58篇 |
临床医学 | 253篇 |
内科学 | 566篇 |
皮肤病学 | 41篇 |
神经病学 | 55篇 |
特种医学 | 500篇 |
外科学 | 213篇 |
综合类 | 29篇 |
预防医学 | 76篇 |
眼科学 | 25篇 |
药学 | 68篇 |
中国医学 | 4篇 |
肿瘤学 | 91篇 |
出版年
2022年 | 10篇 |
2021年 | 23篇 |
2020年 | 20篇 |
2019年 | 17篇 |
2018年 | 42篇 |
2017年 | 22篇 |
2016年 | 33篇 |
2015年 | 36篇 |
2014年 | 62篇 |
2013年 | 87篇 |
2012年 | 67篇 |
2011年 | 67篇 |
2010年 | 87篇 |
2009年 | 76篇 |
2008年 | 62篇 |
2007年 | 50篇 |
2006年 | 63篇 |
2005年 | 38篇 |
2004年 | 43篇 |
2003年 | 44篇 |
2002年 | 40篇 |
2001年 | 28篇 |
2000年 | 45篇 |
1999年 | 43篇 |
1998年 | 136篇 |
1997年 | 126篇 |
1996年 | 132篇 |
1995年 | 93篇 |
1994年 | 75篇 |
1993年 | 84篇 |
1992年 | 30篇 |
1991年 | 35篇 |
1990年 | 26篇 |
1989年 | 62篇 |
1988年 | 53篇 |
1987年 | 60篇 |
1986年 | 48篇 |
1985年 | 53篇 |
1984年 | 26篇 |
1983年 | 32篇 |
1982年 | 36篇 |
1981年 | 21篇 |
1980年 | 37篇 |
1979年 | 16篇 |
1978年 | 17篇 |
1977年 | 18篇 |
1976年 | 25篇 |
1975年 | 25篇 |
1971年 | 8篇 |
1965年 | 10篇 |
排序方式: 共有2418条查询结果,搜索用时 15 毫秒
51.
Hemostatic plug (HP) formation was investigated in the ear bleeding time incision in normal and von Willebrand pigs. HP volume was calculated by integrating the areas of serial sections. In normal pigs (n = 11), platelets immediately formed a layer on the surface of the cut channel. Platelet aggregates formed at the ends of transected vessels and gradually enlarged. Finally, all transected vessels were occluded by HP and bleeding stopped. In contrast, large HPs were formed in the incision in von Willebrand's disease (vWD) pigs (n = 4); these HPs did not cover the ends of the transected vessels, which continued to bleed, allowing the formation of large hemostatically ineffective platelet aggregates in the incision. Canals traversed these HPs, and bleeding from the open vessels may have continued through them. After infusion of cryoprecipitate into a vWD pig, the bleeding time shortened, and the morphological findings of the HPs were similar to those of normal pigs. In normal pigs (n = 3) infused with an anti- Willebrand factor monoclonal antibody, which prolonged the bleeding time, a large HP formed in the incision, similar to that observed in the vWD pig. The volume of the normal and vWD HPs increased with time. These in vivo findings suggest that Willebrand factor is involved in the localization of the HP to the damaged vessel and may also play a role in platelet-platelet interaction. A computerized morphometric technique was used for measuring the volume of the hemostatic plugs and the distance of sequential points on the perimeter of the HP from the center of selected bleeding vessels. 相似文献
52.
53.
54.
J Tang DJ Humes E Gemmil NT Welch SL Parsons JA Catton 《Annals of the Royal College of Surgeons of England》2013,95(5):323-328
Introduction
The high mortality and morbidity associated with resection for oesophagogastric malignancy has resulted in a conservative approach to the postoperative management of this patient group. In August 2009 we introduced an enhanced recovery after surgery (ERAS) pathway tailored to patients undergoing resection for oesophagogastric malignancy. We aimed to assess the impact of this change in practice on standard clinical outcomes.Methods
Two cohorts were studied of patients undergoing resection for oesophagogastric malignancy before (August 2008 – July 2009) and after (August 2009 – July 2010) the implementation of the ERAS pathway. Data were collected on demographics, interventions, length of stay, morbidity and in-hospital mortality.Results
There were 53 and 55 oesophagogastric resections undertaken respectively for malignant disease in each of the study periods. The median length of stay for both gastric and oesophageal resection decreased from 15 to 11 days (Mann– Whitney U, p<0.001) following implementation of the ERAS pathway. There was no significant increase in morbidity (gastric resection 23.1% vs 5.3% and oesophageal resection 25.9% vs 16.7%) or mortality (gastric resection no deaths and oesophageal resection 1.8% vs 3.6%) associated with the changes. There was a significant decrease in the number of oral contrast studies used following oesophageal resection, with a reduction from 21 (77.8%) in 2008–2009 to 6 (16.7%) in 2009–2010 (chi-squared test, p<0.0001).Conclusions
The introduction of an enhanced recovery programme following oesophagogastric surgery resulted in a significant decrease in length of median patient stay in hospital without a significant increase in associated morbidity and mortality. 相似文献55.
In low- and middle-income countries, men who have sex with men (MSM) are 19 times more likely to be HIV positive compared with background populations. Criminalisation and social rejection of homosexuality in most sub-Saharan African countries reinforce stigma and exclude MSM from prevention activities, including HIV testing. This paper's purpose is to identify factors associated with never having been HIV tested (NHT), among a sample of Cameroonian MSM. In 2008, a community-based study was conducted in Douala, the economic capital city of Cameroon, by a local NGO Alternatives-Cameroun, recruiting participants through the snowball technique and administering a questionnaire during face-to-face interviews. Proximity to HIV was investigated according to the following criteria: knowing at least one person living with HIV and having been exposed to HIV prevention interventions. NHT was defined as reporting to have never been HIV tested. A logistic regression was used to identify factors associated with NHT. Among the 165 MSM of our study group who reported that they were not HIV positive, 19% reported NHT. Factors independently associated with NHT were as follows: being younger, being Muslim, not having a steady male partner, not knowing any person living with HIV and never having been exposed to HIV prevention interventions. In this MSM population, a small proportion reported that they had never been HIV tested and among these, the percentage was higher among individuals not in proximity to HIV. Despite the hostile context of sub-Saharan African countries towards MSM, local and national HIV testing campaigns to date may have played a substantial role in raising HIV awareness in the MSM population living in Douala, and peer-based counselling may have educated those in contact with Alternatives-Cameroun regarding the positive value of HIV testing. This result is a further argument for continuing community-based prevention and extending it to difficult-to-reach MSM. 相似文献
56.
57.
Infrequent isolation of extensively drug-resistant (XDR) Klebsiella pneumoniae resistant to colistin in Spain 总被引:1,自引:0,他引:1
58.
59.
60.