全文获取类型
收费全文 | 72699篇 |
免费 | 6560篇 |
国内免费 | 2157篇 |
专业分类
耳鼻咽喉 | 664篇 |
儿科学 | 1401篇 |
妇产科学 | 2289篇 |
基础医学 | 11919篇 |
口腔科学 | 1442篇 |
临床医学 | 7454篇 |
内科学 | 11523篇 |
皮肤病学 | 2104篇 |
神经病学 | 2931篇 |
特种医学 | 2372篇 |
外国民族医学 | 7篇 |
外科学 | 8147篇 |
综合类 | 7922篇 |
现状与发展 | 9篇 |
一般理论 | 7篇 |
预防医学 | 5718篇 |
眼科学 | 620篇 |
药学 | 5990篇 |
40篇 | |
中国医学 | 1144篇 |
肿瘤学 | 7713篇 |
出版年
2024年 | 136篇 |
2023年 | 1213篇 |
2022年 | 2213篇 |
2021年 | 2874篇 |
2020年 | 2995篇 |
2019年 | 2887篇 |
2018年 | 2700篇 |
2017年 | 2773篇 |
2016年 | 3081篇 |
2015年 | 3122篇 |
2014年 | 4670篇 |
2013年 | 5460篇 |
2012年 | 3955篇 |
2011年 | 4317篇 |
2010年 | 3503篇 |
2009年 | 3361篇 |
2008年 | 3228篇 |
2007年 | 3147篇 |
2006年 | 2918篇 |
2005年 | 2606篇 |
2004年 | 2388篇 |
2003年 | 2188篇 |
2002年 | 1910篇 |
2001年 | 1655篇 |
2000年 | 1448篇 |
1999年 | 1208篇 |
1998年 | 1104篇 |
1997年 | 967篇 |
1996年 | 880篇 |
1995年 | 791篇 |
1994年 | 796篇 |
1993年 | 599篇 |
1992年 | 648篇 |
1991年 | 475篇 |
1990年 | 430篇 |
1989年 | 379篇 |
1988年 | 359篇 |
1987年 | 246篇 |
1986年 | 238篇 |
1985年 | 338篇 |
1984年 | 277篇 |
1983年 | 134篇 |
1982年 | 139篇 |
1981年 | 154篇 |
1980年 | 150篇 |
1979年 | 108篇 |
1978年 | 81篇 |
1977年 | 53篇 |
1976年 | 54篇 |
1975年 | 20篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
22.
随着腔镜技术的进一步发展以及微创理念应用于结直肠外科疾病的诊治中,结直肠相关疾病的诊治发生了翻天覆地的变化。由传统的经腹手术到腹腔镜手术、经自然腔道手术,再到经自然腔道取标本手术(NOSES),结直肠疾病的外科诊治在微创领域取得了巨大成果。NOSES技术是目前结直肠外科在微创领域前沿的手术方式之一,它通过经直肠、阴道取标本来避免了腹壁的辅助取标本切口,从而将结直肠外科手术进一步微创化。NOSES技术集传统腹腔镜手术的优势与现代微创外科的理念于一体,它在确保手术效果的基础上集中体现了微创、加速康复外科、功能外科、"无疤"等理念的特点。本文主要就国内外各中心开展NOSES技术在结直肠外科诊治开展中的相关经验、心得和体会进行综述。 相似文献
23.
《Foot and Ankle Surgery》2022,28(4):460-463
The third-generation percutaneous chevron and Akin osteotomy (PECA) technique for surgical management of hallux valgus has shown improvement in clinical and radiographic outcomes. During this procedure, lateral translation and fixation of the first metatarsal head results in the formation of a bony prominence on the medial side of the distal aspect of the first metatarsal which can cause pain and discomfort to the patient. We describe two techniques to address this bony prominence; either i) excision osteotomy and removal of the fragment or ii) a dorsal closing wedge osteotomy retaining the bony fragment.Level of EvidenceLevel V, expert opinion 相似文献
24.
PNPLA3 gene polymorphism and response to lifestyle modification in patients with nonalcoholic fatty liver disease
下载免费PDF全文
![点击此处可从《Journal of gastroenterology and hepatology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
25.
26.
27.
28.
DNA mixture interpretation can produce opposing conclusions by qualified forensic analysts, even within the same laboratory. The long-delayed publication of the National Institutes of Standards and Technology (NIST) study of 109 North American crime laboratories in this journal demonstrates this most clearly. This latest study supports earlier work that shows common methods such as the Combined Probability of Inclusion (CPI) have wrongly included innocent people as contributors to DNA mixtures. The 2016 President's Council of Advisors on Science and Technology report concluded, “In summary, the interpretation of complex DNA mixtures with the CPI statistic has been an inadequately specified—and thus inappropriately subjective—method. As such, the method is clearly not foundationally valid” [7]. The adoption of probabilistic genotyping by many laboratories will certainly prevent some of these errors from occurring in the future, but the same laboratories that produced past errors can also now review old cases with their new software—without additional bench work. It is critical that laboratories adopt procedures and policies to do this. 相似文献
29.
A developmental validation was performed to demonstrate reliability, reproducibility and robustness of the ANDE System with the FlexPlex assay, including an integrated Expert System, across a number of laboratories and buccal sample variations. Previously, the related DNAscan™/ANDE 4C Rapid DNA System using the PowerPlex®16 assay and integrated Expert System Software received NDIS approval in March 2016. The enhanced ANDE instrument, referred to as ANDE 6C, and the accompanying 6-dye, 27-locus STR assay, referred to as FlexPlex, have been developed to be compatible with all widely used global loci, including the expanded set of the CODIS core 20 loci.Six forensic and research laboratories participated in the FlexPlex Rapid DNA developmental validation experiments, testing a total of 2045 swabs, including those obtained from 1387 unique individuals. The goal of this extensive and comprehensive validation was to thoroughly evaluate and document the ANDE System and its internal Expert System to reliably genotype reference buccal swab samples in a manner compliant with the FBI’s Quality Assurance Standards and the NDIS Operational Procedures.The ANDE System, including automated Expert System analysis, generated reproducible and concordant results for buccal swabs when testing various instruments at different laboratories by a number of different operators. When testing a number of non-human DNAs, including oral bacteria, the ANDE System and FlexPlex assay demonstrated limited cross-reactivity. Potential PCR inhibitors were evaluated as part of the validation and no inhibition was detected. Reproducible and concordant profiles were generated from buccal swab samples collected with a limit of detection appropriate for buccal swab collections from arrestees. The precision and resolution of the System met industry standards for detection of microvariants and single base resolution.The integrated Expert System appropriately demonstrated the ability to correctly pass or fail profiles for CODIS upload without human review. During this comprehensive developmental validation, the ANDE System successfully interpreted over 2000 samples tested with over 99.99% concordant alleles. The data package described herein led to the ANDE System with the FlexPlex assay receiving NDIS approval in June 2018. 相似文献
30.
Yuan Peng Yuman Li Haiyan Cao Liu Hong Yu Wang Mingxing Xie 《Journal of ultrasound in medicine》2019,38(2):539-544
A pulmonary artery (PA) sling is a very rare congenital cardiovascular anomaly, and only a few studies have reported PA slings in fetuses. The relationship of the PA, aorta, ductus arteriosus, and trachea can be evaluated in the 3‐vessel and 3‐vessel and trachea views during fetal echocardiography. A PA sling can be detected by abnormal positioning of the left PA in relation to the trachea when sweeping from the 3‐vessel view cranially to the 3‐vessel and trachea view. Here we report 3 cases of fetal PA slings and their follow‐ups. Two cases were confirmed by postnatal echocardiography, and the other case was confirmed by a cardiovascular cast after pregnancy termination. We emphasize that the 3‐vessel and 3‐vessel and trachea views are of crucial importance in the prenatal diagnosis of a PA sling. 相似文献