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   881篇
  免费   66篇
  国内免费   5篇
耳鼻咽喉   11篇
儿科学   58篇
妇产科学   39篇
基础医学   93篇
口腔科学   19篇
临床医学   88篇
内科学   170篇
皮肤病学   50篇
神经病学   82篇
特种医学   23篇
外科学   159篇
综合类   17篇
预防医学   24篇
眼科学   21篇
药学   77篇
中国医学   2篇
肿瘤学   19篇
  2024年   2篇
  2023年   8篇
  2022年   16篇
  2021年   25篇
  2020年   25篇
  2019年   21篇
  2018年   25篇
  2017年   30篇
  2016年   39篇
  2015年   47篇
  2014年   42篇
  2013年   50篇
  2012年   65篇
  2011年   68篇
  2010年   40篇
  2009年   36篇
  2008年   81篇
  2007年   88篇
  2006年   72篇
  2005年   53篇
  2004年   44篇
  2003年   29篇
  2002年   18篇
  2001年   8篇
  2000年   1篇
  1999年   3篇
  1998年   2篇
  1996年   1篇
  1995年   2篇
  1992年   1篇
  1990年   2篇
  1988年   1篇
  1987年   1篇
  1986年   1篇
  1985年   1篇
  1983年   2篇
  1981年   1篇
  1974年   1篇
排序方式: 共有952条查询结果,搜索用时 11 毫秒
11.
12.
OBJECTIVE: The purpose of this trial was to determine the spectrum of diseases with fever of unknown origin (FUO) in Turkey. METHODS: A prospective multicenter study of 154 patients with FUO in twelve Turkish tertiary-care hospitals was conducted. RESULTS: The mean age of the patients was 42+/-17 years (range 17-75). Fifty-three (34.4%) had infectious diseases (ID), 47 (30.5%) had non-infectious inflammatory diseases (NIID), 22 (14.3%) had malignant diseases (MD), and eight (5.2%) had miscellaneous diseases (Mi). In 24 (15.6%) of the cases, the reason for high fever could not be determined despite intensive efforts. The most common ID etiologies were tuberculosis (13.6%) and cytomegalovirus (CMV) infection (3.2%). Adult Still's disease was the most common NIID (13.6%) and hematological malignancy was the most common MD (7.8%). In patients with NIID, the mean duration of reaching a definite diagnosis (37+/-23 days) was significantly longer compared to the patients with ID (25+/-12 days) (p=0.007). In patients with MD, the mean duration of fever (51+/-35 days) was longer compared to patients with ID (37+/-38 days) (p=0.052). CONCLUSIONS: Although infection remains the most common cause of FUO, with the highest percentage for tuberculosis, non-infectious etiologies seem to have increased when compared with previous studies.  相似文献   
13.
14.
Objective:To determine the total oxidant status (TOS), total antioxidant status (TAS), and the 8-hydroxy-2′-deoxyguanosine (8-OHdG) levels and their interrelationship in the saliva of children undergoing fixed orthodontic therapy.Materials and Methods:Thirty children were randomly divided into three groups. The attachments were bonded to all of the teeth using three different orthodontic composites: Transbond XT, Kurasper F, and GrenGloo. The salivary levels of TOS, TAS, and 8-OHdG were determined three times, as follows: before treatment (T1) and at 1 month (T2) and 3 months (T3) following appliance placement. All data were statistically analyzed.Results:There were no significant differences in TOS, TAS, and 8-OHdG within the same time periods among the three different orthodontic composites (P > .05). TAS in all composite groups decreased over time. These decreases were found to be significant for Kurasper F and GrenGloo at the T1–T3 and T2–T3 time periods (P < .05). In all composite groups 8-OHdG decreased between T1 and T2 (P < .05). However, 8-OHdG in all composite groups increased from T2 to T3. These differences in 8-OHdG were significant in Kurasper F and GrenGloo (P < .05).Conclusions:Fixed orthodontic appliances bonded with the tested composites did not increase the cytotoxicity markers in saliva.  相似文献   
15.
16.
17.
The authors investigated the prognostic relevance of serum carbohydrate antigen 125 (CA125) levels in nonischemic dilated cardiomyopathy (NICMP) and assessed whether increased levels relate to the degree of functional mitral regurgitation (FMR). Seventy-seven patients with NICMP were enrolled and followed-up for 10 ± 2 months in this prospective study. Receiver-operating characteristic analysis established a cutoff CA125 value of 25 U/mL for predicting mortality. Patients were divided into two groups according to their CA125 levels (CA125 <25 U/mL [n=58] and CA125 ≥ 25 U/mL [n=19]). Patients with high CA125 values had statistically worse functional status, higher B-type natriuretic peptide (BNP) levels, higher left ventricular volumes, lower ejection fraction, higher E/Em ratio, higher pulmonary artery systolic pressure, and more severe FMR. On the multivariate analysis, serum CA125 (P=.002) and severe FMR (P=.04) were identified as the independent predictors of mortality. Serum CA125 levels also correlated with BNP levels and FMR severity (P<.001). Serum CA125 is a powerful prognostic biomarker that is associated with the severity of heart failure, serum BNP levels and several echocardiographic parameters including left ventricular volumes, systolic and diastolic functions, pulmonary artery pressure, and the degree of FMR. Serum CA125 was also shown as an independent predictor of mortality during 10 ± 2 months of follow-up.  相似文献   
18.
Saving the zone of stasis is one of the major goals of burn specialists. Increasing the tissue tolerance to ischaemia and inhibiting inflammation have been proposed to enable salvage of this zone. After a burn, excessive inflammation, including increased vascular permeability, local tissue oedema and neutrophil activation, causes local tissue damage by triggering vascular thrombosis and blocking capillaries, resulting in tissue ischaemia and necrosis. Oxygen radicals also contribute to tissue damage after a burn. However, macrophages play a pivotal role in the response to burn. We studied β-glucan because of its many positive systemic effects that are beneficial to burn healing, including immunomodulatory effects, antioxidant effects (free-radical scavenging activity) and effects associated with the reduction of the inflammatory response.  相似文献   
19.
INTRODUCTIONEnteropathy-associated T-cell lymphoma (EATL) is a very rare malignancy. Reasons for hospital admission are variable.PRESENTATION OF CASE76 years old man admitted to emergency service with sudden and massive obscure gastrointestinal bleeding. There was no complaints in his history. After initial evaluation, emergency laparatomy had to be done. Bleeding lesion in proximal jejunum was resected. Histopathologically, the muscularis propria had abundant atypical lymphoid infiltrate in diffuse pattern. Atypical lymphoid cells expressed CD3 and CD30. The jejunal mucosa adjacent to the tumor showed effacement of normal villous architecture.DISCUSSIONEATL is known to cause anemia as a result of chronic bleeding. However in this case, the bleeding was abundant, irreplaceable and requiring emergency surgery. To our knowledge it is not reported previously.CONCLUSIONA sudden and massive gastrointestinal bleeding can be the first and unique sign of EATL.  相似文献   
20.
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