全文获取类型
收费全文 | 1559篇 |
免费 | 130篇 |
国内免费 | 2篇 |
专业分类
耳鼻咽喉 | 27篇 |
儿科学 | 21篇 |
妇产科学 | 18篇 |
基础医学 | 253篇 |
口腔科学 | 16篇 |
临床医学 | 174篇 |
内科学 | 253篇 |
皮肤病学 | 19篇 |
神经病学 | 108篇 |
特种医学 | 94篇 |
外科学 | 264篇 |
综合类 | 9篇 |
预防医学 | 102篇 |
眼科学 | 28篇 |
药学 | 110篇 |
中国医学 | 7篇 |
肿瘤学 | 188篇 |
出版年
2023年 | 17篇 |
2022年 | 15篇 |
2021年 | 75篇 |
2020年 | 34篇 |
2019年 | 63篇 |
2018年 | 63篇 |
2017年 | 39篇 |
2016年 | 39篇 |
2015年 | 46篇 |
2014年 | 64篇 |
2013年 | 78篇 |
2012年 | 119篇 |
2011年 | 108篇 |
2010年 | 56篇 |
2009年 | 61篇 |
2008年 | 77篇 |
2007年 | 89篇 |
2006年 | 79篇 |
2005年 | 74篇 |
2004年 | 71篇 |
2003年 | 59篇 |
2002年 | 46篇 |
2001年 | 44篇 |
2000年 | 35篇 |
1999年 | 40篇 |
1998年 | 10篇 |
1997年 | 11篇 |
1996年 | 12篇 |
1995年 | 11篇 |
1994年 | 3篇 |
1993年 | 4篇 |
1992年 | 20篇 |
1991年 | 14篇 |
1990年 | 18篇 |
1989年 | 17篇 |
1988年 | 20篇 |
1987年 | 5篇 |
1986年 | 11篇 |
1985年 | 5篇 |
1984年 | 5篇 |
1983年 | 2篇 |
1981年 | 2篇 |
1979年 | 2篇 |
1974年 | 4篇 |
1972年 | 4篇 |
1971年 | 4篇 |
1970年 | 4篇 |
1969年 | 4篇 |
1968年 | 3篇 |
1967年 | 2篇 |
排序方式: 共有1691条查询结果,搜索用时 15 毫秒
1.
Quang Ngoc Nguyen Linh Dieu Vuong Van-Long Truong To Van Ta Nam Trung Nguyen Hung Phi Nguyen Ha Hoang Chu 《Pathology, research and practice》2019,215(5):885-892
Genetic and epigenetic alterations importantly contribute to the pathogenesis of lung cancer. In the study, we measured the frequency and distribution of molecular abnormalities of EGFR as well as the aberrant promoter methylations of BRCA1, MGMT, MLH1, and RASSF1A in Vietnamese lung adenocarcinomas. We investigated the association between genetic and epigenetic alteration, and between each abnormality with clinicopathologic parameters. Somatic EGFR mutation that was found in 49/139 (35.3%) lung adenocarcinomas showed a significant association with young age, female gender, and non-smokers. EGFR overexpression was identified in 82 tumors (59.0%) and statistical relationships with EGFR or BRCA1 methylation but not EGFR mutation. In addition, EGFR, BRCA1, MGMT, MLH1, and RASSF1A methylations were found in 33 (23.7%), 41 (29.5%), 46 (33.1%), 28 (20.1%), and 41 (29.5%) cases of a total of 139 lung adenocarcinomas, respectively. The RASSF1A methylation was found to be linked to the smoking habit. Methylations in MGMT and RASSF1A were also found to correlate with metastasis status. Furthermore, the distribution of EGFR mutation and that of BRCA1, MGMT or RASSF1A methylation were significantly exclusive in lung adenocarcinomas. The main finding of our study demonstrate that epigenetic abnormalities might play a critical role for the lung tumorigenesis in patients with smoking history and metastasis, and partly affect the predictive value of EGFR mutations through blocking expression due to promoter EGFR hypermethylation. Mutually exclusive distribution of genetic and epigenetic alterations reflects differently biological characteristics in the etiology of lung adenocarcinomas. 相似文献
2.
3.
4.
5.
Diagnostic value of biparametric magnetic resonance imaging (MRI) as an adjunct to prostate‐specific antigen (PSA)‐based detection of prostate cancer in men without prior biopsies 下载免费PDF全文
Soroush Rais‐Bahrami M. Minhaj Siddiqui Srinivas Vourganti Baris Turkbey Ardeshir R. Rastinehad Lambros Stamatakis Hong Truong Annerleim Walton‐Diaz Anthony N. Hoang Jeffrey W. Nix Maria J. Merino Bradford J. Wood Richard M. Simon Peter L. Choyke Peter A. Pinto 《BJU international》2015,115(3):381-388
6.
7.
8.
Do LG Spencer JA Roberts-Thomson K Ha DH Tran TV Trinh HD 《Journal of the International Academy of Periodontology》2003,5(3):77-84
Information about periodontal disease patterns among the populations of developing countries is limited. These populations may illustrate the natural history of the disease owing to low or virtually no access to dental care, contributing to a more complete understanding of the disease process. The present study aimed to describe the patterns of periodontal loss of attachment (LOA) among representative middle-aged Vietnamese adults. A multi-stage, stratified random sampling technique was employed in two randomly selected provinces. The US NIDR protocol with two sites per tooth for the whole mouth, excluding third molars, was used to assess LOA. A total of 575 subjects aged 35-44 years were interviewed and periodontally examined (response 84.6%). Data were re-weighted to reflect the population of the two provinces. Oral hygiene status was poor with high accumulation of plaque and calculus. The prevalence, extent of sites with pockets (PD), recession (GR) and LOA exceeding various thresholds and the severity of LOA were calculated. Almost all subjects presented with at least one site with LOA > or = 2 mm but the higher levels of the disease were skewed. The extent of sites with GR, PD and LOA > or = 4mm was 1.35, 5.04 and 11.81 per cent respectively. More buccal sites had GR, while more mesial sites had PD and LOA. Severity score of LOA was 2.5 (SD: 0.7). LOA of 4+mm were observed more at maxillary molar buccal sites, followed by mandibular incisor mesial sites. LOA was prevalent among middle-aged Vietnamese adults. The loss of periodontal support was positively skewed and varied between teeth and sites. 相似文献
9.
Nguyen Thoa C Witter Dick J Bronkhorst Ewald M Truong Nhan B Creugers Nico HJ 《BMC oral health》2010,10(1):1-11
Background
Dental caries is one of the primary causes of tooth loss among adults. It is estimated to affect a majority of Americans aged 55 and older, with a disproportionately higher burden in disadvantaged populations. Although a number of treatments are currently in use for caries prevention in adults, evidence for their efficacy and effectiveness is limited.Methods/Design
The Prevention of Adult Caries Study (PACS) is a multicenter, placebo-controlled, double-blind, randomized clinical trial of the efficacy of a chlorhexidine (10% w/v) dental coating in preventing adult caries. Participants (n = 983) were recruited from four different dental delivery systems serving four diverse communities, including one American Indian population, and were randomized to receive either chlorhexidine or a placebo treatment. The primary outcome is the net caries increment (including non-cavitated lesions) from baseline to 13 months of follow-up. A cost-effectiveness analysis also will be considered.Discussion
This new dental treatment, if efficacious and approved for use by the Food and Drug Administration (FDA), would become a new in-office, anti-microbial agent for the prevention of adult caries in the United States.Trial Registration Number
NCT00357877 相似文献10.