全文获取类型
收费全文 | 1195篇 |
免费 | 70篇 |
国内免费 | 60篇 |
专业分类
耳鼻咽喉 | 2篇 |
儿科学 | 58篇 |
妇产科学 | 25篇 |
基础医学 | 93篇 |
口腔科学 | 15篇 |
临床医学 | 182篇 |
内科学 | 330篇 |
皮肤病学 | 17篇 |
神经病学 | 46篇 |
特种医学 | 254篇 |
外科学 | 72篇 |
综合类 | 30篇 |
预防医学 | 124篇 |
眼科学 | 11篇 |
药学 | 38篇 |
中国医学 | 2篇 |
肿瘤学 | 26篇 |
出版年
2023年 | 3篇 |
2022年 | 5篇 |
2021年 | 17篇 |
2020年 | 7篇 |
2019年 | 14篇 |
2018年 | 24篇 |
2017年 | 13篇 |
2016年 | 6篇 |
2015年 | 21篇 |
2014年 | 24篇 |
2013年 | 37篇 |
2012年 | 39篇 |
2011年 | 36篇 |
2010年 | 39篇 |
2009年 | 38篇 |
2008年 | 48篇 |
2007年 | 78篇 |
2006年 | 33篇 |
2005年 | 55篇 |
2004年 | 45篇 |
2003年 | 31篇 |
2002年 | 28篇 |
2001年 | 24篇 |
2000年 | 18篇 |
1999年 | 16篇 |
1998年 | 52篇 |
1997年 | 37篇 |
1996年 | 60篇 |
1995年 | 45篇 |
1994年 | 41篇 |
1993年 | 51篇 |
1992年 | 10篇 |
1991年 | 14篇 |
1990年 | 18篇 |
1989年 | 28篇 |
1988年 | 39篇 |
1987年 | 37篇 |
1986年 | 28篇 |
1985年 | 31篇 |
1984年 | 18篇 |
1983年 | 11篇 |
1982年 | 12篇 |
1981年 | 22篇 |
1980年 | 19篇 |
1979年 | 6篇 |
1978年 | 9篇 |
1977年 | 15篇 |
1976年 | 8篇 |
1975年 | 9篇 |
1974年 | 2篇 |
排序方式: 共有1325条查询结果,搜索用时 15 毫秒
1.
C T Gan G P McCann J T Marcus S A van Wolferen J W Twisk A Boonstra P E Postmus A Vonk-Noordegraaf 《The European respiratory journal》2006,28(6):1190-1194
The aim of the current study was to investigate whether alterations in N-terminal pro brain natriuretic peptide (NT-proBNP) reflect changes in right ventricular structure and function in pulmonary hypertension patients during treatment. The study consisted of 30 pulmonary hypertension patients; 15 newly diagnosed and 15 on long-term treatment. NT-proBNP, right heart catheterisation and cardiac magnetic resonance imaging measurements were performed, at baseline and follow-up. There were no significant differences between newly diagnosed patients and those on treatment at baseline or follow-up with respect to NT-proBNP, haemodynamics and right ventricular parameters. Relative changes in NT-proBNP during treatment were correlated to the relative changes in right ventricular end-diastolic volume index (r = 0.59), right ventricular mass index (r = 0.62) and right ventricular ejection fraction (r = -0.81). N-terminal pro brain natriuretic peptide measurements reflect changes in magnetic resonance imaging-measured right ventricular structure and function in pulmonary hypertension patients. An increase in N-terminal pro brain natriuretic peptide over time reflects right ventricular dilatation concomitant to hypertrophy and deterioration of systolic function. 相似文献
2.
Michiel R. de Boer Jos Twisk Annette C. Moll Hennie J. M. Völker-Dieben Henrica C. W. de Vet Ger H. M. B. van Rens 《Ophthalmic & physiological optics》2006,26(6):535-544
Consecutive patients (n = 215) who were referred to optometric (55%) or multidisciplinary (45%) low-vision services and above 50 years of age were recruited from four hospitals in the Netherlands. They completed two vision-related quality of life questionnaires, the Vision Quality of Life Core Measure (VCM1) and the Low Vision Quality of Life Questionnaire (LVQOL), before their first visit with low-vision services and 1 year later. At follow-up, patients referred to multidisciplinary low-vision services had lower scores on the mobility subscale of the LVQOL than patients referred to optometric low-vision services [5.3 points; 95% confidence interval (CI): 0.2-10.5]. Paired sample t-tests for the two groups of patients taken together show improvement for the VCM1 (3.1 points; 95% CI: 0.6-5.6) and deterioration for the basic aspects of vision (3.5 points; 95% CI: 1.1-5.9) and the mobility (6.6 points; 95% CI: 3.7-9.5) subscales of the LVQOL. In conclusion, people referred to optometric services showed less deterioration in mobility than those referred to multidisciplinary services. No differences were observed for any of the other subscales of the LVQOL and the VCM1. Future research in this field should include randomized controlled designs comparing low-vision services with no treatment or placebo. 相似文献
3.
The use of additional epidural sympathetic block during and after microvascular surgery in the lower extremities to prevent vasospasm is generally agreed on. However, a significant fall in the perfusion rate of the transplants was seen after application of bupivacaine (Marcain) via the epidural catheter. This effect has, to our knowledge, not been described before and is probably caused by the sympathectomy effect of this type of analgesia. 相似文献
4.
5.
6.
7.
8.
Short-Ti inversion-recovery pulse sequence: analysis and initial experience in cancer imaging 总被引:2,自引:0,他引:2
Inversion recovery (IR), commonly considered a pulse sequence capable of producing T1-weighted images with excellent display of normal anatomy, is versatile: The null point and peak time provide a useful, succinct summary of the properties of IR and its capacity for producing both T1- and T2-weighted images. Shortening of the inversion time (TI) and creation of a short-TI inversion-recovery (STIR) pulse sequence increases sensitivity to malignancy and other abnormalities by making the effects of prolonged T1 and T2 on signal intensity additive and by nulling the signal from fat. The authors examined over 300 patients with various malignancies and compared STIR images with T1- and T2-weighted images obtained at 0.5 T. In 43 cases, signal-difference-to-noise ratios (SD/Ns) were calculated between tumor, fat, and muscle. In general, STIR images demonstrated tumor as a conspicuously high-intensity area in a background of muted, discernible anatomic detail. The good contrast achieved with STIR sequences between tumor and fat (SD/N = 18.1) and tumor and muscle (SD/N = 12.9) consolidated into a single image the information contained separately on T1- and T2-weighted images, which facilitates efficient detection and localization of malignancy. 相似文献
9.
Sixteen cases of histopathologically proved solitary rectal ulcer syndrome were encountered. Fifteen patients underwent barium enema study; in nine cases the findings--including rectal stricture, granularity of the mucosa, and thickened rectal folds-were nonspecific. In six cases the study was normal. All patients had a long history of defecation disorders, and defecography was performed in all. In seven cases, intussusception of the rectal wall was seen; in another case the intussusception was accompanied by a rectocele. One case showed rectal prolapse. In four cases, failed relaxation of the puborectalis occurred and prevented the passage of the bolus; in another case there was abnormal perineal descent. In two patients studies were normal. In patients with defecation disorders, the possibility of this syndrome should be considered. Defecography is the method of choice for establishing the diagnosis. 相似文献
10.