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   1753篇
  免费   90篇
  国内免费   15篇
耳鼻咽喉   67篇
儿科学   86篇
妇产科学   161篇
基础医学   166篇
口腔科学   76篇
临床医学   135篇
内科学   294篇
皮肤病学   23篇
神经病学   102篇
特种医学   97篇
外科学   392篇
综合类   25篇
预防医学   32篇
眼科学   68篇
药学   63篇
肿瘤学   71篇
  2024年   3篇
  2023年   16篇
  2022年   14篇
  2021年   47篇
  2020年   30篇
  2019年   51篇
  2018年   72篇
  2017年   60篇
  2016年   86篇
  2015年   92篇
  2014年   86篇
  2013年   132篇
  2012年   158篇
  2011年   162篇
  2010年   87篇
  2009年   88篇
  2008年   140篇
  2007年   152篇
  2006年   124篇
  2005年   91篇
  2004年   68篇
  2003年   46篇
  2002年   20篇
  2001年   3篇
  2000年   4篇
  1999年   8篇
  1998年   4篇
  1997年   5篇
  1996年   3篇
  1995年   2篇
  1993年   2篇
  1992年   1篇
  1991年   1篇
排序方式: 共有1858条查询结果,搜索用时 11 毫秒
131.
Acute severe colicky pain in the flank region is termed as renal colic (RC), which is commonly diagnosed and treated in the emergency department (ED). The present study is designed to investigate the hospital costs of patients with RC admitted to the ED and factors affecting the figures. Retrospective analysis includes all patients diagnosed with RC following physical examination and X-ray, ultrasound, computed tomography together with laboratory investigations in the university-based ED between February 2007 and February 2009. The study included 574 patients eligible for the predefined criteria. Mean total hospital cost in patients admitted to the ED due to RC was calculated to be 55.77 Euro. The greatest contribution to the total cost was made by radiological investigations in the ED (40.5%) followed by treatment costs (19.7%). Size and location of the stone and stay times in the ED were the independent variables affecting the costs. The costs were higher as the stones were bigger and as they were more distal in the ureter. Renal stones were associated with the lowest hospital costs. Radiological investigations are the greatest contributors in the ED costs in patients with RC. Effective measures need to be undertaken to reduce resultant costs. Preventive measures as well as diagnostic and therapeutic procedures should be standardized in the ED in accordance with technological advances and also cost-effectiveness when appropriate.  相似文献   
132.

Background

Neuron-specific enolase (NSE) is the most sensitive tumor marker for small-cell lung carcinoma (SCLC) at the time of diagnosis. The main purpose of this study was to review the usefulness of serum NSE level as a prognostic factor in patients with SCLC and to determine the correlation between the NSE level and the stage of disease and response to chemotherapy.

Methods

In this prospective study, patients with SCLC were evaluated for response to chemotherapy, survival without disease progression, and overall survival. The end point was designated at patient death due to SCLC. NSE assays were performed before and after completion of chemotherapy.

Results

Sixty-five patients were included in study. NSE levels were significantly higher in patients who died of SCLC. The pre-treatment NSE levels in patients who responded to treatment were significantly lower. The post-treatment NSE levels were not significantly correlated with response to chemotherapy, progression-free survival, overall survival, and prognosis of patients. Change in the NSE level between the pre- and post-treatment periods was not significantly correlated with response to treatment, progression-free survival, and overall survival.

Conclusions

NSE levels might not be related with the stage of the disease. However, a low pre-treatment NSE level might be used in predicting good response to chemotherapy in patients with SCLC. The post-treatment serum NSE levels and the rate of change between pre- and post-treatment serum levels of NSE were not related with response to chemotherapy, progression-free survival, and overall survival.  相似文献   
133.
Melatonin, a major photoperiod-dependent hormone, regulates circadian rhythms and biological rhythms and acts as a prominent sleep promoter. Symptoms related to hypermelatoninemia have been reported in individuals supplemented with melatonin. However, spontaneous endogenous hypermelatoninemia has not been reported previously. A 6-year-old girl previously diagnosed with Shapiro's syndrome was admitted to our hospital on several occasions during a 1-year period with complaints of altered consciousness, syncope, hypothermia and episodes of sweating. The episodes occurred daily and during sleep and lasted for 1-6 h. During these episodes, she sweated profusely and felt faint and her skin was pale and cool. Other complaints included recurrent abdominal pain, urge incontinence and myopia. She was shown to have hypermelatoninemia (>1,000 pg/ml, normal range 0-150 pg/ml) during these episodes. The duration of her attacks decreased with phototherapy and she was successfully treated with propranolol. To our knowledge, this is the first case of hypermelatoninemia without any detectable organic pathology. We did not determine the exact mechanism of hypermelatoninemia in this patient; however, it might have been related to irregular control of pinealocytes by the suprachiasmatic nucleus or related pathways. Hypermelatoninemia should be considered in patients with spontaneous periodic hypothermia and hyperhidrosis, and also in patients with Shapiro's syndrome.  相似文献   
134.

Aim

The purpose of this study was to identify how remitters and relapsers view their everyday problem solving strategies.

Method

A total of 128 male alcohol dependent male inpatients who were hospitalized at the Ankara University Psychiatry Clinic, Alcohol and Substance Abuse Treatment Unit were recruited for the study. Subjects demographic status and alcohol use histories were assessed by a self-report questionnaire. Also, patients were evaluated with The Coopersmith Self-esteem Inventory (CSI), The Spielberger State-Trait Anxiety Scale (STAI-I-II), and The Problem Solving Inventory (PSI). Patients were followed for six months with monthly intervals after hospital discharge. Drinking status was assessed in terms of abstinence and relapse. Data were assessed with Student t-test, and univariate and multivariate analyses. In the logistic regression analysis, age, marital status, employment status and PSI subscores were taken as the independent variables and drinking state at the end of six months as the dependent variable.

Results

There were significant differences in reflective and avoidant styles, and monitoring style of problem solving between abstainers and relapses. It was found that subjects who perceived their problem solving style as less avoidant and less reflective were at greater risk to relapse.

Conclusions

The findings demonstrated that active engagement in problem solving like utilizing avoidant and reflective styles of problem solving enhances abstinence. In treatment, expanding the behavior repertoire and increasing the variety of ways of problem solving ways that can be utilized in daily life should be one of the major goals of the treatment program.  相似文献   
135.
BackgroundOsteoblasts and osteoclasts are known to express Ang II type I (AT1) receptor in cell cultures, suggesting the existence of local renin-angiotensin system (RAS) in bone. This study was designed to investigate the effects of losartan as AT1 receptor blocker on ovariectomized rats' femur.MethodsLosartan (5 mg/kg/day) was administered via oral gavage for 8 weeks. Bone mineral density (BMD) was measured using dual energy X-ray absorptiometry, while tensile and three-point bending tests were performed for evaluation of biomechanical properties of bone. The trabecular porosity was analyzed by scanning electron microscopy.ResultsThere was a significant decrease in BMD values of ovariectomized rats' femurs which were reversed by losartan treatment. According to tensile test results, ultimate tensile strength and strain values of losartan treated ovariectomized rats' femurs increased and decreased, respectively, when compared to that of ovariectomized animals. Losartan treatment also caused a significant recovery in flexural strength and modulus parameters regarding respective control values, which mean losartan treated ovariectomized rats' femur had more force tolerance until break than ovariectomized rats' femur. Quantitative microscopic analysis showed larger trabecular porosity in ovariectomized rats than control rat femurs and it was significantly decreased after losartan treatment.ConclusionBlockage of AT1 receptor increased strength, mass and trabecular connections of ovariectomized rat femurs. Therefore, it is tempting to speculate that drugs, including AT1 receptor blockers, may be used for the treatment of osteoporosis or reduction of its detrimental effects in the future.  相似文献   
136.
137.
Background  Cardiovascular complications are common in patients with end-stage renal disease (ESRD). We aimed to investigate left ventricular (LV) function and carotid intima-media thickness (cIMT) in children and adolescents with ESRD. Methods  This study included 38 ESRD patients (15 hemodialysis and 23 peritoneal dialysis) and 17 age- and sex-matched healthy subjects. Results  The ESRD patients had significantly lower mean mitral E/A ratio, and higher left ventricular mass index (LVMI) and cIMT than the control group. Compared with PD patients, HD patients had worse LV diastolic function. In stepwise linear regression analysis, LVMI (P = 0.043) and hemoglobin (P = 0.015) turned out to be independent variables for predicting diastolic dysfunction (reduced E/A ratio), and the only significant predictor of cIMT was indexed diastolic blood pressure (DBP) (P = 0.035). Conclusion  Cardiovascular structure and function abnormalities are also common in pediatric dialysis patients, as in adults. Furthermore our data indicated that hemodialysis was disadvantageous for preserving LV diastolic function as compared with peritoneal dialysis.  相似文献   
138.
We report an interesting morphological alteration in the adrenal of a 72-year-old woman suffering from severe hypertension due to primary hyperaldosteronism. The laparoscopic left adrenalectomy specimen revealed an adrenal cortical adenoma composed of varying proportions of oncocytic and clear cells, predominantly showing central oncocytic change. Oncocytes also exhibited numerous eosinophilic intracytoplasmic globular inclusions, which are not commonly observed in aldosterone-producing adrenal cortical adenomas. Ultrastructural study revealed that the inclusions originated in degenerating mitochondria, explaining their association with the oncocytic phenotype of the tumor.  相似文献   
139.
Background  Type III supracondylar humeral fracture is a common cause of emergency hospitalization among children requiring surgical treatment. The configuration of the internal fixation material, surgical technique, and optimal timing of surgery (TS) have always been popular topics of debate. The TS in uncomplicated cases is usually determined by surgeons. Methods  In this study, we prospectively followed children with type III supracondylar fractures. We aimed to clarify the effects of injury side, gender, and post-injury delay on switching to open surgery and the ease of the reduction. Results  Based on our results, the probability of switching to open surgery increased by a factor of 4 every 5 h beginning 15 h after injury. Open surgery was necessary after 32 h. Conclusion  Reduction became technically more difficult as TS increased.  相似文献   
140.
The thrombophilia in adult life has major implications in the hepatic vessels. The resulting portal vein thrombosis has various outcomes and complications. Esophageal varices, portal gastropathy, ascites, severe hypersplenism and liver failure needing liver transplantation are known well. The newly formed collateral venous circulation showing itself as pseudocholangicarcinoma sign and its possible clinical reflection as cholestasis are also known from a long time. The management strategies for these complications of portal vein thrombosis are not different from their counterpart which is cirrhotic portal hypertension, but the prognosis is unquestionably better in former cases. In this review we present and discuss the portal vein thrombosis, etiology and the resulting clinical pictures. There are controversial issues in nomenclature, management (including anticoagulation problems), follow up strategies and liver transplantation. In the light of the current knowledge, we discuss some controversial issues in literature and present our experience and our proposals about this group of patients.  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