全文获取类型
收费全文 | 40256篇 |
免费 | 2162篇 |
国内免费 | 136篇 |
专业分类
耳鼻咽喉 | 434篇 |
儿科学 | 2572篇 |
妇产科学 | 955篇 |
基础医学 | 4979篇 |
口腔科学 | 702篇 |
临床医学 | 2824篇 |
内科学 | 7859篇 |
皮肤病学 | 1351篇 |
神经病学 | 2595篇 |
特种医学 | 1260篇 |
外科学 | 5350篇 |
综合类 | 998篇 |
一般理论 | 26篇 |
预防医学 | 2459篇 |
眼科学 | 1605篇 |
药学 | 3068篇 |
中国医学 | 165篇 |
肿瘤学 | 3352篇 |
出版年
2023年 | 304篇 |
2022年 | 652篇 |
2021年 | 1220篇 |
2020年 | 708篇 |
2019年 | 897篇 |
2018年 | 1148篇 |
2017年 | 826篇 |
2016年 | 1031篇 |
2015年 | 1045篇 |
2014年 | 1518篇 |
2013年 | 1862篇 |
2012年 | 2746篇 |
2011年 | 2768篇 |
2010年 | 1566篇 |
2009年 | 1287篇 |
2008年 | 2210篇 |
2007年 | 2292篇 |
2006年 | 2064篇 |
2005年 | 1919篇 |
2004年 | 1782篇 |
2003年 | 1652篇 |
2002年 | 1413篇 |
2001年 | 794篇 |
2000年 | 744篇 |
1999年 | 689篇 |
1998年 | 354篇 |
1997年 | 274篇 |
1996年 | 229篇 |
1995年 | 200篇 |
1994年 | 166篇 |
1993年 | 189篇 |
1992年 | 402篇 |
1991年 | 427篇 |
1990年 | 362篇 |
1989年 | 380篇 |
1988年 | 330篇 |
1987年 | 298篇 |
1986年 | 285篇 |
1985年 | 304篇 |
1984年 | 242篇 |
1983年 | 199篇 |
1979年 | 252篇 |
1978年 | 167篇 |
1977年 | 157篇 |
1976年 | 140篇 |
1975年 | 166篇 |
1974年 | 155篇 |
1973年 | 181篇 |
1972年 | 145篇 |
1971年 | 127篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
BackgroundLittle is known about the extent of ordering low-value services by.PurposeTo compare the rates of low-value back images ordered by primary care physicians (PCMDs) and primary care nurse practitioners (PCNPs).MethodWe used 2012 and 2013 Medicare Part B claims for all beneficiaries in 18 hospital referral ?regions (HRRs) and a measure of low-value back imaging from Choosing Wisely. Models included random clinician effect and fixed effects for beneficiary age, disability, Elixhauser comorbidities, clinician sex, the emergency department setting, back pain visit volume, organization, and region (HRR).FindingsPCNPs (N = 231) and PCMDs (N = 4,779) order low-value back images at similar rates (NP: all images: 26.5%; MRI/CT: 8.4%; MD: all images: 24.5%; MRI/CT: 7.7%), with no detectable significant difference when controlling for covariates.DiscussionPCNPs and PCMDs order low-value back images at an effectively similar rate. 相似文献
2.
3.
Gupta Archana A. Mammo Danny A. Page Michael A. 《Albrecht von Graefes Archiv fur klinische und experimentelle Ophthalmologie》2020,258(1):167-173
Graefe's Archive for Clinical and Experimental Ophthalmology - To evaluate the long-term safety and efficacy of intrastromal bevacizumab for treatment of deep corneal neovascularization in... 相似文献
4.
5.
Josh Greenstein Devjani Das Josie Acuna Monica Kapoor Cara Brown Abbas Husain Brendan Lally Barry Hahn 《The American journal of emergency medicine》2019,37(2):313-316
Background
In the emergency department, rib fractures are a common finding in patients who sustain chest trauma. Rib fractures may be a sign of significant, underlying pathology, especially in the elderly patients where rib fractures are associated with significant morbidity and mortality. To date, no studies have evaluated the ability of ultrasound to detect rib fractures using cadaver models and subsequently use this model as a teaching tool.Objectives
The purpose of this study was to determine if it is possible to generate rib fractures on cadaver models which could be accurately identified using ultrasound.Methods
This was a cross-sectional study performed during one session at a cadaver lab. A single hemithorax from four adult cadavers were used as models. Single rib fractures on each of rib five through eight were created. Four subjects, blinded to the normal versus fractured ribs, were asked to identify the presence of a fracture on each rib.Results
A total of 8 of 16 potential ribs had fractured induced by study staff. Mean accuracy was 55% for all subjects. The overall sensitivity and specificity for detecting rib fractures was 50% (CI: 31.89–68.11) and 59.38% (CI: 35.69–73.55) respectively. The overall PPV and NPV was 55.17% and 54.29% respectively.Conclusions
In this pilot study, subjects were not able to detect induced rib fractures using ultrasound on cadaver models. The use of this model as a teaching tool in the detection of rib fractures requires further investigation. 相似文献6.
7.
8.
Metabolic abnormalities of gastrointestinal mucosa in celiac disease: An in vitro proton nuclear magnetic resonance spectroscopy study 下载免费PDF全文
9.
Dinesh Singhal Nandini Vasdev Arvinder Soin Subash Gupta Samiran Nundy 《Indian journal of gastroenterology》2006,25(4):206-207
It is difficult to distinguish between carcinoid tumors of the pancreatic head and periampullary region and carcinomas preoperatively. Between 1996 and 2002, 125 consecutive pancreaticoduodenectomies done by us for periampullary tumors (14 carcinoids, 111 carcinomas) were analyzed. Patients with carcinoid tumors had significantly younger mean age (48 vs. 54 years), longer history (32 vs. 8 weeks), lower serum total bilirubin levels (1.4 vs. 6.3 mg/dL) and on CT scan, had larger, well-localized tumors (5 cm vs. 2 cm). Their postoperative course was better with no mortality or major morbidity, whereas after resection for carcinoma 7 (6.3%) patients died and 30 (27%) had major postoperative complications. Thus, a tumor of this region in a young patient with indolent history, low bilirubin level and with CT scan depicting a large expansile lesion suggests a carcinoid. Such tumors may be safely resected with low postoperative morbidity and mortality and good long-term prognosis. 相似文献
10.
Mariana Spitz Alexandre Aluízio Costa Machado Rodrigo do Carmo Carvalho Fernanda Martins Maia Monica Santoro Haddad Dagoberto Calegaro Milberto Scaff Egberto Reis Barbosa 《Movement disorders》2006,21(9):1520-1522
We report on 3 patients with pseudoathetosis, which are involuntary, slow, writhing movements due to loss of proprioception. 相似文献