全文获取类型
收费全文 | 2513072篇 |
免费 | 200146篇 |
国内免费 | 4560篇 |
专业分类
耳鼻咽喉 | 36791篇 |
儿科学 | 78236篇 |
妇产科学 | 66657篇 |
基础医学 | 354700篇 |
口腔科学 | 71929篇 |
临床医学 | 226075篇 |
内科学 | 492720篇 |
皮肤病学 | 51864篇 |
神经病学 | 213259篇 |
特种医学 | 102703篇 |
外国民族医学 | 925篇 |
外科学 | 382594篇 |
综合类 | 57207篇 |
现状与发展 | 1篇 |
一般理论 | 1006篇 |
预防医学 | 198117篇 |
眼科学 | 59158篇 |
药学 | 187204篇 |
4篇 | |
中国医学 | 4706篇 |
肿瘤学 | 131922篇 |
出版年
2018年 | 26561篇 |
2017年 | 20661篇 |
2016年 | 23166篇 |
2015年 | 26189篇 |
2014年 | 36691篇 |
2013年 | 55235篇 |
2012年 | 75292篇 |
2011年 | 78568篇 |
2010年 | 46236篇 |
2009年 | 44025篇 |
2008年 | 74858篇 |
2007年 | 79781篇 |
2006年 | 80726篇 |
2005年 | 79168篇 |
2004年 | 76092篇 |
2003年 | 73717篇 |
2002年 | 72686篇 |
2001年 | 116836篇 |
2000年 | 120980篇 |
1999年 | 102260篇 |
1998年 | 29230篇 |
1997年 | 26627篇 |
1996年 | 26324篇 |
1995年 | 25333篇 |
1994年 | 23885篇 |
1993年 | 22285篇 |
1992年 | 81412篇 |
1991年 | 78326篇 |
1990年 | 75431篇 |
1989年 | 72470篇 |
1988年 | 67299篇 |
1987年 | 66224篇 |
1986年 | 62654篇 |
1985年 | 59718篇 |
1984年 | 45214篇 |
1983年 | 38460篇 |
1982年 | 23455篇 |
1981年 | 20889篇 |
1979年 | 42408篇 |
1978年 | 29814篇 |
1977年 | 25051篇 |
1976年 | 23473篇 |
1975年 | 24834篇 |
1974年 | 30576篇 |
1973年 | 28896篇 |
1972年 | 27069篇 |
1971年 | 24953篇 |
1970年 | 23505篇 |
1969年 | 21768篇 |
1968年 | 19839篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
61.
Bifid mandibular canal. 总被引:1,自引:0,他引:1
PURPOSE: To determine the incidence and characteristics of bifid mandibular canals. METHODS: A retrospective study was performed using panoramic radiographs of 2012 patients subjected to dental treatment in the Dental Clinic of the Valencia University Dental School (Valencia, Spain) between 1996 and 1999. The goal was to investigate the presence of double mandibular canals. RESULTS: The extraoral panoramic radiographs revealed a total of 7 images suggestive of bifid canals. Mandibular computed tomography revealed the existence of this anatomic variant in 2 of 3 patients. An analysis was performed on the incidence of this type of image in extraoral panoramic radiography, its possible interpretations, and the clinical implications of bifid mandibular canals. CONCLUSIONS: In this study, 0.35% of canals were bifid. All cases were in women. 相似文献
62.
Contour defects resulting in deformity caused by lack of tissue can be improved by conventional surgery using autologous tissue, but there is always a donor site morbidity. Integra has been available since the early 1980's for use in acute burns and more recently in reconstruction. It has been shown histologically to act as a tissue regeneration template. The regenerated dermis is buried under an autologous thin split-skin graft. In this study, the principle of burying Integra (without the silicone layer) has been applied to deep tissue defects in 12 reconstructive cases. Such regenerated tissues survive at least 3 years after burying. Modification to the technique to avoid visible edges are being developed. 相似文献
63.
Terry J DuBose 《Journal of ultrasound in medicine》2003,22(12):1420-1; author reply 1421-2
64.
65.
66.
Ohne Zusammenfassung 相似文献
67.
68.
We evaluated the acquisition and performance of a high-precision locomotor task in patients with Parkinson's disease (PD) and healthy subjects. All subjects walked on a treadmill and had to step repetitively as low as possible over an obstacle without touching it. During blocks 1 and 2, the subjects had full vision and received additional acoustic warning and feedback signals. During block 3, vision became restricted. Changes in foot clearance and the number of obstacle hits were evaluated. Initially, PD patients performed poorer and improved foot clearance slower. After task repetition, the groups performed similarly. Restricting vision deteriorated performance in both groups. The similar performance of PD patients after task repetition might indicate that adequate training could improve adaptive locomotor behavior in PD patients. 相似文献
69.
J Müller-Quernheim K I Gaede E Fireman G Zissel 《The European respiratory journal》2006,27(6):1190-1195
An increase in chronic beryllium disease (CBD) has been suggested due to higher industrial use of beryllium alloys. Since occupational CBD is a perfect phenocopy of sarcoidosis, it might be misdiagnosed as sarcoidosis. In the current it was hypothesised that CBD exists in cohorts of sarcoidosis patients. In a prospective case study, sarcoidosis patients were evaluated for potential beryllium exposure. In those patients in whom beryllium exposure was confirmed and beryllium hypersensitivity demonstrated, the diagnosis of sarcoidosis was rejected and corrected to CBD. In 84 patients seen for re-evaluation or making a diagnosis of sarcoidosis, beryllium exposure was recognised and a diagnosis of CBD was made in 34 out of 84 patients. The time lag between clinical diagnosis of sarcoidosis and the final diagnosis of CBD ranged 0-18 yrs (median 3 yrs) and the mean (range) age at time of diagnosis of CBD was 43.9(25-80) yrs. Beryllium-contaminated workplaces causing disease encompassed a wide spectrum of industries and technical trades in which beryllium-exposure is generally not perceived as a health hazard. In conclusion, chronic beryllium disease still belongs to the spectrum of differential diagnoses of granulomatous disorders. 相似文献
70.
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