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   257篇
  免费   25篇
  国内免费   3篇
儿科学   15篇
妇产科学   11篇
基础医学   18篇
口腔科学   13篇
临床医学   20篇
内科学   69篇
皮肤病学   2篇
神经病学   11篇
特种医学   1篇
外科学   35篇
综合类   3篇
预防医学   8篇
眼科学   53篇
药学   21篇
中国医学   1篇
肿瘤学   4篇
  2024年   1篇
  2023年   3篇
  2022年   5篇
  2021年   5篇
  2020年   7篇
  2019年   9篇
  2018年   13篇
  2017年   17篇
  2016年   12篇
  2015年   9篇
  2014年   13篇
  2013年   20篇
  2012年   25篇
  2011年   18篇
  2010年   23篇
  2009年   17篇
  2008年   14篇
  2007年   27篇
  2006年   14篇
  2005年   7篇
  2004年   5篇
  2003年   4篇
  2002年   6篇
  2000年   1篇
  1995年   1篇
  1989年   4篇
  1987年   3篇
  1986年   2篇
排序方式: 共有285条查询结果,搜索用时 15 毫秒
71.
G‐protein‐coupled receptor 55 (GPR55) has been proposed as an atypical cannabinoid receptor, which is activated by lysophosphatidylinositols and some synthetic or endogenous cannabinoid molecules. The exact role of GPR55 receptors in the central nervous system especially in anxiety needs to be evaluated. In this study, the effects of intracerebroventricular (i.c.v.) administration of agonist and antagonist of GPR55 receptor on anxiety‐related behaviors in rats were investigated. Here, O‐1602 (GPR55 agonist) at the doses of 0.2, 1, and 5 μg/rat increased %OAT and %OAE but not the locomotor activity, showing an anxiolytic response, whereas i.c.v. injection of ML193 (GPR55 antagonist) at the doses of 0.1 and 1 μg/rat increased anxiety‐like behaviors while causing locomotor impairment. The antagonistic effect of ML193 on the anxiolytic‐like effect of O‐1602 was also evaluated. The results showed that ML193 decreased the anxiolytic‐like effect of O‐1602. Based on these results, it may be concluded that central GPR55 may have a role in modulation of anxiety‐like behaviors in rats. Further experiments are needed to elucidate the exact role of these receptors in anxiety.  相似文献   
72.
Left atrial appendage (LAA) contractile dysfunction is associated with thrombus formation and systemic embolism. LAA function is determined by its flow velocities and fractional area change. This study was performed in order to determine the LAA functions with the anatomic M-mode echocardiography (AMME). Our study comprised 74 patients who had sinus rhythm and underwent transesophageal echocardiography (TEE) for various reasons. LAA fractional change (LAAFAC) was measured by manual planimetry in a transverse basal short-axis approach and LAA emptying and filling velocities also were measured. The AMME values were determined by an M-mode cross section from a cursor placed beneath the orifice of the LAA in transverse basal short-axis imaging. From these values LAA fractional shortening (LAAFS) and ejection fraction (LAAEF) were calculated. LAAEF was calculated by the Teicholz method. The comparisons were conducted, and no correlations between the LAA late filling and the anatomic M-mode values were found (for LAAFS r = 0.18; P > 0.05 and for LAAEF r = 0.19; P > 0.05). There were significant but poor correlations among the LAA late emptying with the anatomic M-mode measurements (for LAAFS r = 0.26; P < 0.05 and for LAAEF r = 0.30; P < 0.01), whereas, there were significant and good correlations between the LAAFAC and the anatomic M-mode values (for LAAFS r = 0.75; P < 0.01 and for LAAEF r = 0.78; P < 0.01). There were significant differences between the valvular heart disease group and the normal group, and between the valvular heart disease group and the ASD group (for LAAFAC P < 0.01, for LAAEF P < 0.01, for LAAFS P < 0.01). There was no difference between the normal group and the ASD group. Our study showed that the LAAEF and LAAFS in patients with sinus rhythm obtained via anatomical M-mode echocardiography is a new method, which can be used instead of left atrial appendage area change.  相似文献   
73.
Left sinus of Valsalva aneurysms particularly acquired type are rare reported cases in the literature. We present a fistularized large pseudoaneurysm of the left sinus of Valsalva into the left ventricle caused by atherosclerotic changes in a 61-year-old man presenting with dyspenea and three episodes of chest pain since one month prior to surgery. We describe its characteristics, surgical approach and associated lesions.  相似文献   
74.
The long-term risk of malignancy among renal transplant patients is approximately 100 times that of the general population. Unlike North America and many European countries, Kaposi's sarcoma is the most common cancer after renal transplantation in most series reported from the Middle East. Human herpes virus-8 (HHV-8) has a major role in the pathogenesis of Kaposi's sarcoma. The risk of posttransplantation Kaposi's sarcoma is 23% to 28% among seropositive patients compared with 0.7% among seronegative patients. This study was conducted to investigate the seroprevalence of HHV-8 among our transplant recipients. The sera from 100 renal transplant recipients were examined by indirect immunofluorescence against latent nuclear antigen. Sixty of 100 patients were males. The overall mean age was 41.1 years (range, 17-74 years) with 17 patients older than 55 years. The mean transplantation duration was 41.6 months. Twenty-five percent of patients were seropositive for HHV-8. There was statistically significant seropositivity for HHV-8 among recipients older than 55 years (P=.02). Eight of 17 patients older than 55 years were seropositive (47%), whereas 17/83 patients younger than 55 years were seropositive (20%). There were no significant differences for HHV-8 seropositivity regarding sex, transplantation duration, and immunosuppressive regimen, including dose of immunosuppressive drugs and cyclosporine blood levels. In this study, we showed seropositivity for HHV-8 among a significant percentage of our renal transplant recipients, a finding which may render them at risk to develop Kaposi's sarcoma. Seropositive and seronegative patients were followed for 16 months. One HHV-8 seropositive patient (1/25) developed Kaposi's sarcoma.  相似文献   
75.
76.

Objective

To calculate cut-off point for the adenosine deaminase (ADA) activity in the CSF of patients with tuberculous meningitis (TBM).

Patients and methods

The ADA assay was based on the automatic indirect method in which ADA catalyzes adenosine to inosine. ADA activity in the CSF was calculated based on ammonia liberated from adenosine and quantified spectrophotometrically. Arithmetic mean values and standard deviation of each variable were measured. Mann–Whitney U and Fisher exact tests were applied to compare continuous and dichotomous variables between tuberculous and non-tuberculous groups. A receiver operating characteristic curve was plotted to identify various cut-off points to determine the best level for ADA activity.

Results

Totally 42 patients were enrolled into the study. The median of ADA activity in the TBM group was 22 and in the non-TBM group was 8.0. The mean CSF-ADA activity was found to be significantly higher in TBM group (23.05 ± 13.1 IU/L) than in the CSF from non-TBM patients (9.39 ± 5.18 IU/L). The highest accuracy is at the cut-off value of 10.5 IU/L. The sensitivity and specificity of the test at this cut-off to differentiate TBM from non-tuberculous meningitis is 81% and 86% respectively.

Conclusion

Considering that a high positive value of ADA activity cannot confirm TBM, however, in suspected patients it may lead the physician to treat patient earlier before the confirmatory diagnostic reports will be received. The suggested cut-off value in this pilot study is 10.5 IU/L with high sensitivity and specificity.  相似文献   
77.
78.
79.
Meniscal injuries are frequently associated with anterior cruciate ligament (ACL) tears. Clinical tests that are useful for detecting meniscal tears may not be valid in this setting. The Thessaly test, a newly described dynamic clinical examination, has been shown to have a very high diagnostic accuracy for detecting meniscal tears. This study evaluates the accuracy of the Thessaly test in patients with combined ACL and meniscus injuries. We examined eighty patients with ACL deficiency for meniscal injuries using the Thessaly test (at 20° of knee flexion), the lateral and medial joint line tenderness tests, and the McMurray test. Examiners were blinded to the MRI report on the conditions of the menisci. All patients underwent arthroscopic ACL reconstruction during which the menisci were evaluated by direct vision and probing. During the Thessaly test, six patients developed severe pain and could not complete the test. Sensitivity, specificity, likelihood ratios and predictive values were calculated for all tests. The Thessaly test had a sensitivity of 79%, specificity of 40%, positive predictive value of 56%, negative predictive value of 66%, positive likelihood ratio of 1.33, negative likelihood ratio of 0.51%, and overall accuracy of 60%. We concluded that the Thesally test has a low specificity in patients with combined ACL and meniscal injuries and can not be recommended as a diagnostic test in this setting.  相似文献   
80.
Background and Aim The relationship between blood group antigens and peptic ulcer disease has been widely evaluated in the past. Data concerning the same association with upper gastrointestinal bleeding are very limited. We aimed to evaluate this association and we thought it was worthwhile to try to determine whether these components take some part in this complication. Methods The study population consisted of 1,098 adults (364 patients and 734 volunteer blood donors as controls). Demographic features, comorbid illnesses, and use of aspirin/nonsteroidal anti-inflammatory drugs (NSAIDs) were recorded. Blood groups were examined by gel centrifugation method. We included only patients with bleeding from peptic ulcer disease and erosive gastropathy. Ulcers were classified by using Forrest’s classification system in terms of rebleeding risk. Helicobacter pylori was examined by histology. Results The gender distribution was similar in both groups. The ABO blood group phenotype distribution in patients and controls (respectively) was as follows: 46.2% versus 34.9% for group O, 32.4% versus 39.5% for group A, 15.7% versus 18.4% for group B, and 5.8% versus 7.2% for group AB. Blood group O was found to have higher frequency in the patient group than in the control group (P = 0.004). Rh positivity was also higher in patients than in controls (P = 0.007). H. pylori positivity was similar between blood groups among patients. The rebleeding and mortality rates between blood groups were also similar. Conclusion ABO blood group O had an important role in patients with upper gastrointestinal bleeding. The impact of blood group on rebleeding and mortality may be a focus for further studies.  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