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   644篇
  免费   31篇
  国内免费   7篇
耳鼻咽喉   14篇
儿科学   26篇
妇产科学   42篇
基础医学   52篇
口腔科学   9篇
临床医学   73篇
内科学   155篇
皮肤病学   31篇
神经病学   21篇
特种医学   27篇
外科学   132篇
综合类   7篇
一般理论   1篇
预防医学   27篇
眼科学   16篇
药学   20篇
肿瘤学   29篇
  2023年   4篇
  2022年   8篇
  2021年   10篇
  2020年   11篇
  2019年   13篇
  2018年   20篇
  2017年   21篇
  2016年   22篇
  2015年   35篇
  2014年   37篇
  2013年   41篇
  2012年   50篇
  2011年   32篇
  2010年   22篇
  2009年   18篇
  2008年   51篇
  2007年   38篇
  2006年   41篇
  2005年   43篇
  2004年   45篇
  2003年   34篇
  2002年   27篇
  2001年   18篇
  2000年   10篇
  1999年   9篇
  1998年   9篇
  1997年   4篇
  1996年   1篇
  1995年   3篇
  1994年   2篇
  1992年   1篇
  1991年   1篇
  1990年   1篇
排序方式: 共有682条查询结果,搜索用时 0 毫秒
41.
OBJECTIVE: To determine the effectiveness of postoperative local anesthesia in tonsillectomy patients using an intra-individual study design. METHODS: Thirty patients aged 5-15 were included in a prospective study. Patients received a local infiltration of 0.5% bupivacaine solution on the right tonsillar bed, and received a local infiltration of normal saline on the left tonsillar bed. Patients were asked to localize pain in terms of most disturbing side of the pharynx, on the 1st, 4th, 8th, 16th, 24th hours. RESULTS: Regarding pain over a 24-h period, there was a significant difference between two sides, after the 8th hour. CONCLUSION: Postoperative local bupivacaine infiltration in tonsillectomy patients was effective in children.  相似文献   
42.
OBJECTIVE: Constitutive activation of various hormone and growth factor receptors is newly recognised as a common cause of tumour development. This study investigated the presence of any mutation or polymorphism of prolactin receptor (PRLR) in 38 patients with breast cancer. RESEARCH METHODS: Genomic DNA was extracted and PCR amplification was carried out for exon 1-10 of PRLR from tumoral and adjacent non-cancerous breast tissue of tumour specimens from 38 breast cancer patients. PCR products were analysed by SSCP and automatic sequencing for mutations. RESULTS: For the first time, A150C (Leu-->Ile) transversion at exon 6 of PRLR in tumour tissues, in adjacent non-cancerous breast tissues, and in blood samples of two (5.3%) out of 38 patients with breast cancer were detected. In contrast to this finding, no polymorphism of PRLR in blood samples of 100 normal individuals were found. CONCLUSION: Polymorphism of prolactin receptors might play a role in mammary carcinogenesis as a consequence of intracellular changes of PRLR signalling.  相似文献   
43.
This study examined the perceptions of medical sales representatives of job related duties, job qualifications needed, and motivating factors and tested for differences based on gender, age, years of experience and education using prior research as a base. This study also explored issues that may arise between sales people and physicians. The authors surveyed 132 medical sales representatives from pharmaceutical firms located in Ankara, Turkey. The authors' findings highlight the need in Turkey for developing in-service training programs for medical sales representatives, especially in the areas related to technical aspects of the product, effective marketing and personal selling strategies, and consumer relations. Training in these areas will help salespeople to better manage the problems typically encountered in physician-sales representative relations. While the study was conducted in Turkey, the results are similar to findings in prior research conducted in other countries and therefore may be of interest to all sales managers.  相似文献   
44.
Leptin receptor variant in women with polycystic ovary syndrome   总被引:3,自引:0,他引:3  
  相似文献   
45.
CT fluoroscopy-guided percutaneous needle biopsies in thoracic mass lesions   总被引:5,自引:0,他引:5  
OBJECTIVE: We aimed to evaluate the usefulness of computed tomographic (CT) fluoroscopy guidance for transthoracic needle biopsies. METHODS AND MATERIAL: CT fluoroscopy-guided biopsies were performed in 81 patients with thoracic mass lesions. Interrupted CT fluoroscopy technique was used with 50-130 mA at 120 kV exposure parameters and slice thickness of 10 mm. We used aspirating needle in 41 patients, cutting needle in 28 patients, and both in 12 patients. We obtained adequate biopsy material in 69 patients at first attempt. Mean fluoroscopy time was 15.17 s and maximum procedure time was 18 min. RESULTS: Adequate samples for pathological diagnosis were obtained in all lesions. Pathological diagnoses were malignant in 41 patients, benign in 27 patients, and suspiciously malignant in 13 patients. There was no significant difference between diagnostic accuracy of the needles in malignant and benign lesions. Complications were observed in 11 patients (13.5%). DISCUSSION AND CONCLUSION: CT fluoroscopy-guided technique provides effective real-time needle biopsy in patients with small tumor size and with tumor located near blood vessels, and in non-compliant patients for diagnosing thoracic lesions.  相似文献   
46.
OBJECTIVE: To investigate the dose-related effects of theophylline in prevention of ischemia-reperfusion injury of the lung. DESIGN: Experimental study. SETTINGS: University hospital. PARTICIPANTS: Thirty Wistar rats. INTERVENTIONS: In experimental group 1 (G-I) (n = 5) 20 mg/L, in G-II (n = 5) 100 mg/L, in G-III (n = 5) 400 mg/L, and in G-IV (n = 5) 1000 mg/L of theophylline was added to modified Euro-Collins solution and perfused the lungs. Lungs were extracted without an ischemic period in control group 1 (C-I) and perfused with modified Euro-Collins solution in control group 2 (C-II). Lungs were kept in a hypothermic state for 6 hours and then ventilated for 30 minutes with 100% O(2). MEASUREMENTS AND MAIN RESULTS: Tissue levels of dien congugate (DC) and malonylaldehyde (MDA) were measured. Comparison of 6 groups revealed statistically significant differences for DC and MDA (p < 0.0001 for both comparisons). Both DC and MDA levels of C-II were found to be higher than G-III and G-IV (p = 0.008). DC and MDA levels of G-III and G-IV were significantly lower than G-I and G-II (p = 0.008 for all comparisons). CONCLUSION: The results of this study showed that 400 mg/L and 1000 mg/L of theophylline added to the modified Euro-Collins solution decreased the intermediate products of lipid peroxidation. Theophylline merits further investigation in ischemia-reperfusion studies as a potentially beneficial agent.  相似文献   
47.
OBJECTIVE: To compare two commonly used sperm-preparation techniques, density gradient centrifugation and swim-up procedures, with respect to their effects on acrosome reaction (AR), hypoosmotic swelling (HOS) and nuclear maturity in men with abnormal and normal semen analyses. STUDY DESIGN: In accordance with World Health Organization criteria, 23 men with abnormal (group I) and 20 men with normal (group II) semen analyses were included in a prospective, controlled study. Each semen specimen was divided into aliquots in order to assess AR, HOS and nuclear maturity, determined with acridine orange staining, in both raw and processed semen samples using the density gradient centrifugation and swim-up techniques. RESULTS: Initial semen samples in group I revealed diminished AR, HOS and nuclear maturity rates in comparison to those in group II. In group I, density gradient centrifugation improved AR, HOS and nuclear maturity rates more than did swim-up. However, in group II it improved only the AR; HOS rates were better than with swim-up. There was a significant positive correlation between sperm concentration and HOS rate in raw semen samples from group I. In the same group, motility and morphology correlated with the nuclear maturity rate but not with AR and HOS rates. Semen samples with better motility (> 20%) or morphology (> 25%) showed better nuclear maturity rates (> 50%) in men with abnormal semen analyses. Motility had a sensitivity of 77% and specificity of 90% in predicting nuclear maturity. Morphology had similar sensitivity but lower specificity (70%). CONCLUSION: Density gradient centrifugation is superior to the swim-up technique in improving AR, HOS and nuclear maturity rates in men with abnormal semen analyses. However, when only nuclear maturity rate is taken into account, the swim-up technique seems to be sufficient for selecting spermatozoa in men with normal semen analyses. The nuclear maturity rate also correlates with sperm morphology and motility.  相似文献   
48.
Objective The aim of this study was to test the validity and reliability of the Turkish version of the diabetes quality of life (DQOL) questionnaire for use with patients with diabetes. Methods Turkish version of the generic quality of life (QoL) scale 15D and DQOL, socio-demographics and clinical parameter characteristics were administered to 150 patients with type 2 diabetes. Study participants were randomly sampled from the Endocrinology and Diabetes Outpatient Department of Dr. Lutfi Kirdar Kartal Education and Research Hospital in Istanbul, Turkey. Results The Cronbach alpha coefficient of the overall DQOL scale was 0.89; the Cronbach alpha coefficient ranged from 0.80 to 0.94 for subscales. Distress, discomfort and its symptoms, depression, mobility, usual activities, and vitality on the 15 D scale had statistically significant correlations with social/vocational worry and diabetes-related worry on the DQOL scale indicating good convergent validity. Factor analysis identified four subscales: satisfaction”, impact”, “diabetes-related worry”, and “social/vocational worry”. Conclusion Statistical analyses showed that the Turkish version of the DQOL is a valid and reliable instrument to measure disease related QoL in patients with diabetes. It is a simple and quick screening tool with about 15 ± 5.8 min administration time for measuring QoL in this population.  相似文献   
49.
50.
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