全文获取类型
收费全文 | 3272篇 |
免费 | 315篇 |
国内免费 | 30篇 |
专业分类
耳鼻咽喉 | 26篇 |
儿科学 | 179篇 |
妇产科学 | 68篇 |
基础医学 | 551篇 |
口腔科学 | 91篇 |
临床医学 | 333篇 |
内科学 | 596篇 |
皮肤病学 | 87篇 |
神经病学 | 316篇 |
特种医学 | 302篇 |
外科学 | 311篇 |
综合类 | 67篇 |
一般理论 | 1篇 |
预防医学 | 178篇 |
眼科学 | 89篇 |
药学 | 191篇 |
1篇 | |
中国医学 | 2篇 |
肿瘤学 | 228篇 |
出版年
2023年 | 13篇 |
2022年 | 20篇 |
2021年 | 66篇 |
2020年 | 65篇 |
2019年 | 51篇 |
2018年 | 74篇 |
2017年 | 52篇 |
2016年 | 51篇 |
2015年 | 96篇 |
2014年 | 91篇 |
2013年 | 136篇 |
2012年 | 166篇 |
2011年 | 162篇 |
2010年 | 141篇 |
2009年 | 126篇 |
2008年 | 123篇 |
2007年 | 179篇 |
2006年 | 165篇 |
2005年 | 178篇 |
2004年 | 118篇 |
2003年 | 111篇 |
2002年 | 111篇 |
2001年 | 76篇 |
2000年 | 58篇 |
1999年 | 65篇 |
1998年 | 107篇 |
1997年 | 98篇 |
1996年 | 81篇 |
1995年 | 74篇 |
1994年 | 59篇 |
1993年 | 59篇 |
1992年 | 39篇 |
1991年 | 48篇 |
1990年 | 41篇 |
1989年 | 65篇 |
1988年 | 57篇 |
1987年 | 47篇 |
1986年 | 29篇 |
1985年 | 46篇 |
1984年 | 25篇 |
1983年 | 25篇 |
1982年 | 24篇 |
1981年 | 18篇 |
1980年 | 23篇 |
1979年 | 16篇 |
1978年 | 15篇 |
1977年 | 23篇 |
1976年 | 18篇 |
1975年 | 13篇 |
1972年 | 16篇 |
排序方式: 共有3617条查询结果,搜索用时 15 毫秒
1.
Kuo-yi Jade Chang MHealthEc MHM BSc Lisa Lorraine Dillon MSpecEd BPsych Lil Deverell COMS PhD MEd GradDipO&M BEd Mei Ying Boon PhD BOptom FAAO Lisa Keay PhD MPH BOptom 《Clinical & experimental optometry》2020,103(4):434-448
Despite orientation and mobility (O&M) being a significant factor determining quality of life of people with low vision or blindness, there are no gold standard measures or agreement on how to measure O&M performance. In the first part of this systematic review, an inventory of O&M outcome measures used by recent studies to assess the performance of orientation and/or mobility of adults with vision impairment (low vision and blindness) is presented. A wide variety of O&M outcome measures have been implemented in different fields of study, such as epidemiologic research and interventional studies evaluating training, assistive technology, vision rehabilitation and vision restoration. The most frequent aspect of outcome measures is efficiency such as time, distance, speed and percentage of preferred walking speed, followed by obstacle contacts and avoidance, and dis/orientation and veering. Other less commonly used aspects are target identification, safety and social interaction and self-reported outcome measures. Some studies employ sophisticated equipment to capture and analyse O&M performance in a laboratory setting, while others carry out their assessment in real-world indoor or outdoor environments. In the second part of this review, the appropriateness of implementing the identified outcome measures to assess O&M performance in clinical and functional O&M practice is evaluated. Nearly a half of these outcome measures meet all four criteria of face validity (either clinical or functional), responsiveness, reliability and feasibility and have the potential to be implemented in clinical or functional O&M practice. The findings of this review confirm the complicated and dynamic nature of O&M. Multiple measures are required in any evaluation of O&M performance to facilitate holistic assessment of O&M abilities and limitations of each individual. 相似文献
2.
3.
4.
5.
Pyomyositis: characteristics at CT and MR imaging 总被引:9,自引:0,他引:9
6.
A mutated intron sequence codes for an antigenic peptide recognized by cytolytic T lymphocytes on a human melanoma. 总被引:17,自引:0,他引:17
下载免费PDF全文
![点击此处可从《Proceedings of the National Academy of Sciences of the United States of America》网站下载免费的PDF全文](/ch/ext_images/free.gif)
P G Coulie F Lehmann B Lethé J Herman C Lurquin M Andrawiss T Boon 《Proceedings of the National Academy of Sciences of the United States of America》1995,92(17):7976-7980
We have identified an antigen recognized on a human melanoma by autologous cytolytic T lymphocytes. It is encoded by a gene that is expressed in many normal tissues. Remarkably, the sequence coding for the antigenic peptide is located across an exon-intron junction. A point mutation is present in the intron that generates an amino acid change that is essential for the recognition of the peptide by the anti-tumor cytotoxic T lymphocytes. This observation suggests that the T-cell-mediated surveillance of the integrity of the genome may extend to some intronic regions. 相似文献
7.
AJ Larner MRCP 《International journal of clinical practice》1994,48(5):272-274
SUMMARY A case is reported of pseudohyperphosphataemia in association with a monoclonal gammopathy of undetermined significance. 相似文献
8.
9.
D De AJ Kanwar S Handa 《Journal of the European Academy of Dermatology and Venereology》2006,20(7):853-859
BACKGROUND: Diagnosis of atopic dermatitis (AD) depends on clinical features because no definitive diagnostic test exists. Criteria proposed by Hanifin and Rajka (Acta Derm Venereol (Stockh) 1980; Suppl 92: 44-47) were acceptable for hospital-based studies but were found not to be suitable for field studies. A UK working party formulated clinical diagnostic criteria that could be used in both hospital and epidemiological settings. Validation studies of the criteria showed widely variable results, probably due to different clinical settings and ethnicity. AIM AND OBJECTIVE: This study was undertaken to validate Hanifin and Rajka's criteria and to assess the comparative efficacy of their criteria and the UK working party's diagnostic criteria in the diagnosis of AD in a hospital setting in North India. SUBJECTS AND METHODS: This study serially included 101 patients with AD and 48 controls of paediatric age group. The study period was from July 2003 to December 2004. RESULTS: Hanifin and Rajka's criteria (sensitivity 96%, specificity 93.75%, positive predictive value 97% (PPV) and negative predictive value (NPV) 91.84%) had a statistical advantage over the UK working party's diagnostic criteria (sensitivity 86%, specificity 95.83%, PPV 97.75% and NPV 76.67%), with a P-value < 0.005. 相似文献
10.
S den Boon N W White S W P van Lill M W Borgdorff S Verver C J Lombard E D Bateman E Irusen D A Enarson N Beyers 《The international journal of tuberculosis and lung disease》2006,10(8):876-882
SETTING: A tuberculosis (TB) prevalence survey was performed in 2002 in two urban communities in Cape Town, South Africa. The population was 36,334 in 2001, and the TB notification rate was 341 per 100,000 population for new smear-positive TB in 2002. OBJECTIVE: To evaluate the relative contributions of symptom and chest radiographic (CXR) screening in the detection of subjects with smear- and/or culture-positive TB in prevalence surveys. DESIGN: Information on symptoms, CXR abnormalities, sputum smear and culture was gathered from a random cluster sample of 1170 adults (aged > or = 15 years). Smear and/or culture-positive TB was used as the gold standard. RESULTS: Of 1170 adults, 29 had bacteriologically positive TB (smear- and/or culture-positive). The presence of any abnormalities on CXR had the highest sensitivity for detecting subjects with bacteriologically positive TB (0.97, 95%CI 0.90-1.00). Specificity for any abnormalities on CXR was 0.67 (95%CI 0.64-0.70). The specificity of any of five TB-related symptoms was 0.68 (95%CI 0.65-0.71). Individual symptoms had low sensitivities, ranging from 0.10 for fever to 0.54 for cough of > or = 2 weeks. CONCLUSION: In this TB prevalence survey, CXR screening, but not symptom screening, was a sensitive alternative to sputum examination of all participants. 相似文献