首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   10671篇
  免费   838篇
  国内免费   50篇
耳鼻咽喉   87篇
儿科学   167篇
妇产科学   143篇
基础医学   1351篇
口腔科学   380篇
临床医学   1090篇
内科学   2427篇
皮肤病学   268篇
神经病学   1073篇
特种医学   868篇
外科学   1662篇
综合类   62篇
一般理论   8篇
预防医学   493篇
眼科学   191篇
药学   627篇
中国医学   13篇
肿瘤学   649篇
  2024年   14篇
  2023年   145篇
  2022年   326篇
  2021年   583篇
  2020年   284篇
  2019年   447篇
  2018年   511篇
  2017年   387篇
  2016年   418篇
  2015年   484篇
  2014年   575篇
  2013年   670篇
  2012年   988篇
  2011年   903篇
  2010年   511篇
  2009年   490篇
  2008年   642篇
  2007年   590篇
  2006年   494篇
  2005年   416篇
  2004年   388篇
  2003年   343篇
  2002年   269篇
  2001年   71篇
  2000年   51篇
  1999年   46篇
  1998年   58篇
  1997年   41篇
  1996年   25篇
  1995年   23篇
  1994年   24篇
  1993年   17篇
  1992年   20篇
  1991年   23篇
  1990年   17篇
  1989年   22篇
  1988年   15篇
  1987年   17篇
  1986年   20篇
  1985年   17篇
  1984年   12篇
  1982年   11篇
  1981年   9篇
  1980年   12篇
  1978年   10篇
  1977年   14篇
  1974年   7篇
  1973年   13篇
  1971年   13篇
  1967年   11篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
22.
23.
24.
A rare case of an infected chronic hematoma in a patient with immunodeficiency syndrome mimicking a soft tissue neoplasm is presented. There are few reported cases of hematogenous infection of chronic hematomas, which be difficult to differentiate from soft tissue neoplasms.  相似文献   
25.
Abstract: Limonene is a monoterpene present in citrus fruit and is used as flavouring agents of foods. It was shown that monoterpenes possess antioxidant activity. Previously, it was demonstrated that limonene exerts anti‐proliferative action on a lymphoma cell line without modifying normal lymphocyte viability. H2O2 has a modulator role in cell proliferation. In the present study, the effect of limonene on normal lymphocytes proliferation and its relation with H2O2 level modulation was analysed, evaluating its effect on the activity of cell antioxidant enzymes, such as catalase, peroxidase and superoxide dismutase. Limonene exerted a biphasic effect on cell proliferation; the increase in cell proliferation was related to the decrease in H2O2 level by the increase in catalase and peroxidase activities. Moreover, limonene protected the cells to the oxidative stress induced by exogenous addition of H2O2. In view of these results, it is possible that limonene could protect normal lymphocytes from diseases related to oxidative stress, including cancer, but further research is necessary to establish the role of limonene as a potential antioxidant that can effectively protect lymphocytes from oxidative stress and mitochondrial dysfunction.  相似文献   
26.
A polymerase chain reaction (PCR) method for the detection of the glmM gene, selected as Helicobacter pylori target sequence, was improved. While performing pathogenicity island cagA gene detection to discriminate pathogenic strains in atherosclerotic carotid samples, several cagA-positive but glmM-negative samples were found. Polymorphisms present in the region amplified in the nested PCR reaction could explain this result; primers were therefore designed to perform a seminested reaction; this modification optimized sensitivity while maintaining specificity. A real-time PCR for Helicobacter DNA detection was also setup. The combination of all 4 PCR reactions detected 83% of H. pylori DNA-positive samples in atherosclerotic carotid tissue, 64% of which were cagA gene positive.  相似文献   
27.
Accelerating cardiac cine 3D imaging using k-t BLAST.   总被引:1,自引:0,他引:1  
By exploiting spatiotemporal correlations in cardiac acquisitions using k-t BLAST, gated cine 3D acquisitions of the heart were accelerated by a net factor of 4.3, making single breathhold acquisitions possible. Sparse sampling of k-t space along a sheared grid pattern was implemented into a cine 3D SSFP sequence. The acquisition of low-resolution training data, which was required to resolve aliasing in the k-t BLAST method, was either interleaved into the sampling process or obtained in a separate prescan to allow for shorter breathhold durations in patients with heart disease. Volumetric datasets covering the heart with 20 slices at a spatial resolution of 2 x 2 x 5 mm3 were recorded with 20 cardiac phases in a total breathhold duration of 25-27 sec, or 18 sec if partial Fourier sampling was additionally employed. The feasibility of the method was demonstrated on healthy volunteers and on patients. The comparison of endocardial area derived from single slices of the 3D dataset with values extracted from separate single-slice acquisitions showed no significant differences. By shortening the acquisition substantially, k-t BLAST may greatly facilitate volumetric imaging of the heart for evaluation of regional wall motion and the assessment of ventricular volume and ejection fraction.  相似文献   
28.
Abstract A single blind 30 day study compared the reduction of plaque and gingivitis for the Hapika® Powerbrush to the Interplak® ultra 10 tuft. A longitudinal parallel group design was utilized and screening evaluation was performed to determine patient eligibility prior to study enrollment. 66 subjects were entered into the study and assigned to 1 of 2 groups, each using one of the toothbrushes. At baseline, subjects received an oral soft tissue exam, a dental hard tissue exam, and were scored by the Lobene modification of the Löe and Silness gingival index (GI). Plaque was then disclosed and scored both pre and post brushing using the modified Turesky plaque/debris examination and an interproximal bleeding examination was performed post-brushing. On days 15 and 30, after an oral soft tissue and GI examination, plaque was graded by the Modified Turesky plaque/debris exam. Subjects then brushed and were graded by the Modified Turesky plaque/debris examination and an interproximal bleeding index examination. The results showed that both brushes provided a similar change in clinical indices. All produced a statistically significant reduction from baseline to day 30 for the gingival index (26.5-29.1%), the bleeding index (13.8-24.1%), and the plaque index (16.9-19.4%), A comparison of pre and post brushing scores for the plaque index at 30 showed that both brushes reduced plaque similarly with a statistically significant reduction (P<0.05) from their pre-brushing plaque index scores at all time periods.  相似文献   
29.
In this paper the authors evaluate the long-term results of treatment for articular calcaneus fractures with Westhues method. This evaluation is performed with regard to triple measurement of B?hler's angle value and to subjective criteria. The clinical material from years 1985-2002 consists of 47 patients aged between 24 and 56 years (mean age 32 years) with articular calcaneus fractures--namely, 41 male patients (87.2%) and 6 female patients (12.8%). The follow-up examination was performed in 24 patients (51% of all patients), namely, in 23 male patients (48.8%) and in one female patient (2.2%). Minimum follow-up time was 12 months and maximum was 9 years. Acquired results suggest that Westhues method restores normal B?hler's angle value only in tongue-type calcaneous fractures.  相似文献   
30.
Venöse Thromboembolien (VTE) stellen eine häufige Morbiditäts- und Mortalitätsursache dar; die jährliche Inzidenz wird mit etwa 1 : 1 000 angegeben. Dabei sind verschiedene Risikogruppen zu unterscheiden, die sowohl durch endogene Faktoren (z. B. genetisch deteminierte Thrombophilie), viel häufiger aber durch exogene Faktoren (zugrundeliegende Erkankung) charakterisiert werden. Diese Heterogenität resultiert in Besonderheiten bei Prophylaxe und Therapie von VTE, auf die in dieser Darstellung eingegangen werden soll.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号