全文获取类型
收费全文 | 5944篇 |
免费 | 386篇 |
国内免费 | 24篇 |
专业分类
耳鼻咽喉 | 37篇 |
儿科学 | 255篇 |
妇产科学 | 83篇 |
基础医学 | 690篇 |
口腔科学 | 141篇 |
临床医学 | 513篇 |
内科学 | 1206篇 |
皮肤病学 | 119篇 |
神经病学 | 486篇 |
特种医学 | 186篇 |
外科学 | 919篇 |
综合类 | 149篇 |
一般理论 | 2篇 |
预防医学 | 293篇 |
眼科学 | 282篇 |
药学 | 543篇 |
中国医学 | 22篇 |
肿瘤学 | 428篇 |
出版年
2023年 | 52篇 |
2022年 | 94篇 |
2021年 | 215篇 |
2020年 | 112篇 |
2019年 | 149篇 |
2018年 | 183篇 |
2017年 | 105篇 |
2016年 | 170篇 |
2015年 | 201篇 |
2014年 | 232篇 |
2013年 | 293篇 |
2012年 | 498篇 |
2011年 | 527篇 |
2010年 | 260篇 |
2009年 | 225篇 |
2008年 | 336篇 |
2007年 | 280篇 |
2006年 | 298篇 |
2005年 | 254篇 |
2004年 | 236篇 |
2003年 | 172篇 |
2002年 | 127篇 |
2001年 | 76篇 |
2000年 | 98篇 |
1999年 | 63篇 |
1998年 | 41篇 |
1997年 | 29篇 |
1996年 | 28篇 |
1995年 | 27篇 |
1994年 | 20篇 |
1993年 | 16篇 |
1992年 | 78篇 |
1991年 | 41篇 |
1990年 | 53篇 |
1989年 | 39篇 |
1988年 | 40篇 |
1987年 | 42篇 |
1986年 | 37篇 |
1985年 | 36篇 |
1984年 | 24篇 |
1979年 | 41篇 |
1978年 | 27篇 |
1977年 | 27篇 |
1975年 | 23篇 |
1974年 | 27篇 |
1973年 | 38篇 |
1972年 | 32篇 |
1971年 | 22篇 |
1970年 | 21篇 |
1935年 | 16篇 |
排序方式: 共有6354条查询结果,搜索用时 15 毫秒
1.
2.
Kevin Kyung Ho Choi Santosh Sanagapalli 《World journal of gastrointestinal oncology》2022,14(3):568-586
Barrett's esophagus (BE) is the precursor to esophageal adenocarcinoma (EAC). Progression to cancer typically occurs in a stepwise fashion through worsening dysplasia and ultimately, invasive neoplasia. Established EAC with deep involvement of the esophageal wall and/or metastatic disease is invariably associated with poor long-term survival rates. This guides the rationale of surveillance of Barrett’s in an attempt to treat lesions at an earlier, and potentially curative stage. The last two decades have seen a paradigm shift in management of Barrett’s with rapid expansion in the role of endoscopic eradication therapy (EET) for management of dysplastic and early neoplastic BE, and there have been substantial changes to international consensus guidelines for management of early BE based on evolving evidence. This review aims to assist the physician in the therapeutic decision-making process with patients by comprehensive review and summary of literature surrounding natural history of Barrett’s by histological stage, and the effectiveness of interventions in attenuating the risk posed by its natural history. Key findings were as follows. Non-dysplastic Barrett’s is associated with extremely low risk of progression, and interventions cannot be justified. The annual risk of cancer progression in low grade dysplasia is between 1%-3%; EET can be offered though evidence for its benefit remains confined to highly select settings. High-grade dysplasia progresses to cancer in 5%-10% per year; EET is similarly effective to and less morbid than surgery and should be routinely performed for this indication. Risk of nodal metastases in intramucosal cancer is 2%-4%, which is comparable to operative mortality rate, so EET is usually preferred. Submucosal cancer is associated with nodal metastases in 14%-41% hence surgery remains standard of care, except for select situations. 相似文献
3.
4.
5.
6.
Lungiswa L Nkonki Tanya M Doherty Zelee Hill Mickey Chopra Nikki Schaay Carl Kendall 《AIDS research and therapy》2007,4(1):27
Background
The objective of this study was to examine missed opportunities for participation in a prevention of mother-to-child transmission (PMTCT) programme in three sites in South Africa. A rapid anthropological assessment was used to collect in-depth data from 58 HIV-positive women who were enrolled in a larger cohort study to assess mother-to-child HIV transmission. Semi-structured interviews were conducted with the women in order to gain an understanding of their experiences of antenatal care and to identify missed opportunities for participation in PMTCT. 相似文献7.
Immunodiagnosis of Entamoeba histolytica and Ascaris lumbricoides infections in Caucasian and aboriginal Australians 总被引:1,自引:0,他引:1
J S Welch C Dobson S Chopra 《Transactions of the Royal Society of Tropical Medicine and Hygiene》1986,80(2):240-247
The immunodiagnostic efficiency of an indirect immunofluorescence test (IFAT) and in vitro lymphocyte proliferative responsiveness (cell mediated immunity test, CMIT) used to measure the immunological responses of individuals with known natural Entamoeba histolytica and Ascaris lumbricoides infections, was studied under survey conditions. E. histolytica was common among Aborigines from Cherbourg, Kowanyama and Central Australia, but it was not found in Brisbane Caucasians. The protozoan was selected for the study because it was prevalent and purified antigen was commercially available. Immunodiagnosis for A. lumbricoides was made using an antigen prepared by affinity chromatography. Diagnosis based on frequency distribution of immunological data gave valid assessment of the number of infected individuals in each population studied. 相似文献
8.
Sheetal Chopra Anna S Lev-Toaff Fatih Ors Diane Bergin 《Journal of ultrasound in medicine》2006,25(5):617-27; quiz 629
OBJECTIVE: The purpose of this presentation is to show the imaging findings of the common and uncommon variants of adenomyosis as seen on sonography and magnetic resonance imaging (MRI). METHODS: A 3-year database search was performed to identify women who had pelvic sonography and pelvic MRI within a 6-month interval. Images of these cases were retrospectively reviewed. RESULTS: Eighty women were identified. Adenomyosis was diagnosed on MRI, which was used as the reference standard, in 45 of these women. The correct diagnosis was made on sonography in 73% of the cases. CONCLUSIONS: Awareness of the spectrum of imaging features of adenomyosis is important to use sonography effectively for diagnosing this entity and to help avoid misdiagnosis. 相似文献
9.
A total of 168 strains of Salmonella were isolated in the Command Pathology Laboratory (WC) Delhi Cantt during the year 1990. Out of this, 143 were Salmonella typhi, 17 Salmonella paratyphi A, 7 Salmonella typhimurium and 1 Salmonella manhattan. The commonest phage type and biotype of Salmonella typhi was type E1 and type 1 respectively. The dominant biotype of Salmonella paratyphi A was type I. There was a very high degree of multidrug resistance of most of the strains. But all the strains were sensitive to ciprofloxacin and norfloxacin. 相似文献
10.
Comparison of survival in cardiac surgery at a Veterans Administration hospital and its affiliated university hospital 总被引:5,自引:0,他引:5
D C Kress G M Kroncke P S Chopra D J Cohen P W Rasmussen R D Nichols E S Beatty H A Berkoff 《Archives of surgery (Chicago, Ill. : 1960)》1988,123(4):439-443
Survival data were reviewed for 3330 open cardiac procedures from 1975 through 1984 at the William S. Middleton Memorial Veterans Hospital, Madison, Wis, and the University of Wisconsin Hospitals and Clinics, Madison. Respective operative survivals were 98.6% and 98.7% for myocardial revascularizations with vein graft or internal mammary artery (CABG), 96.2% and 96.8% for CABG reoperation, 97.8% and 95.9% for aortic valve replacement, 96.3% and 90.3% for aortic valve replacement plus CABG, 100.0% and 94.9% for mitral valve replacement, and 100.0% and 82.9% for mitral valve replacement plus CABG. There were no significant differences in six-year survival curves between hospitals despite threefold differences in average annual caseload (88 vs 294). This suggest that residency-directed cardiac surgery programs can function equally as well at a Veterans Administration hospital as at an affiliated university hospital. 相似文献