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   799篇
  免费   38篇
  国内免费   5篇
耳鼻咽喉   20篇
儿科学   41篇
妇产科学   37篇
基础医学   68篇
口腔科学   64篇
临床医学   72篇
内科学   123篇
皮肤病学   12篇
神经病学   40篇
特种医学   18篇
外科学   177篇
综合类   14篇
预防医学   32篇
眼科学   46篇
药学   36篇
中国医学   1篇
肿瘤学   41篇
  2023年   6篇
  2022年   11篇
  2021年   21篇
  2020年   17篇
  2019年   17篇
  2018年   14篇
  2017年   13篇
  2016年   35篇
  2015年   26篇
  2014年   25篇
  2013年   31篇
  2012年   66篇
  2011年   68篇
  2010年   36篇
  2009年   24篇
  2008年   63篇
  2007年   66篇
  2006年   48篇
  2005年   45篇
  2004年   27篇
  2003年   37篇
  2002年   39篇
  2001年   14篇
  2000年   14篇
  1999年   8篇
  1998年   10篇
  1997年   5篇
  1996年   9篇
  1995年   5篇
  1994年   4篇
  1992年   11篇
  1991年   6篇
  1990年   1篇
  1989年   5篇
  1988年   2篇
  1987年   2篇
  1986年   7篇
  1985年   2篇
  1978年   1篇
  1973年   1篇
排序方式: 共有842条查询结果,搜索用时 15 毫秒
1.
2.
OBJECTIVE: This study aimed to investigate the rate of occupational sensitization to horse hair in grooms and whether occupational exposure to horse hair increases respiratory and allergic symptoms and affects lung function in grooms or not. METHODS: This is a cross-sectional study. Two hundred grooms were randomly selected among 1000 grooms working in Veliefendi Hippodrome of Istanbul. One hundred and twenty-five subjects agreed to enter the study. Ninety-two workers who worked in the different parts of this hippodrome enrolled as the control group. A detailed questionnaire including respiratory and allergic symptoms was filled in, physical examination, skin prick tests and pulmonary function tests were performed. RESULTS: Sensitization to horse hair was 12.8% in grooms and 4.3% in controls. The difference was statistically significant (P = 0.0035). Asthma was found in 14.4% of the grooms and 5.4% of the controls, allergic rhinitis in 42.4% of the grooms and 18.4% of the controls, allergic conjunctivitis in 35.2% of the grooms and 15.2% of the controls, and allergic skin diseases in 32.8% of the grooms and 13% of the controls. The differences were statistically significant (P = 0.043, P = 0.0002, P = 0.001 and P = 0.0008, respectively). The means of FEV1, FEV1/FVC and FVC parameters were significantly lower in the groom group (P = 0.006, P = 0.001 and P = 0.003, respectively). In the multivariate analysis, being in the groom group and working years were found to be predictive factors for impairments of lung function (P < 0.001 and P = 0.002, respectively). CONCLUSION: Occupational exposure to horse increases the sensitization to horse hair, induces asthma and allergic symptoms and also impairs lung functions.  相似文献   
3.
In living donor liver transplantation (LDLT), obtaining the precise volume of the graft is very important to decrease volume-related postoperative complications, especially in cases with suspected small-for size grafts. We used stereology based on the Cavalieri method (CM), a new method to measure liver graft volume, and compared the results with those obtained through intraoperative measurement (IOM) and through multidetector computed tomography (MDCT) measurement. Liver volumes estimated using the 3 methods were well-correlated with each other (r(2) = 0.94 and P < 0.001 for IOM and CM; r(2) = 0.91 and P < 0.001 for IOM and MDCT, and r(2) = 0.95 and P < 0.001 for CM and MDCT); however, they were different from each other (in descending order, 908 +/- 124 cm(2), 861 +/- 121 cm(2), and 777 +/- 168 cm(2) for MDCT, CM, and IOM, respectively). Although MDCT and CM overestimated the volumes, the results of CM were almost similar to those obtained via IOM. In conclusion, our results suggest that CM measured the liver graft volume more reliably. Thus, its use, particularly in cases with suspected small-for-size graft, may prove useful.  相似文献   
4.
OBJECTIVE: The purpose of the present study was to determine the distribution and level of temperature, in a model of a maxillary canine, the surrounding periodontal tissues, and the bones, during a System B heat obturation technique simulation. STUDY DESIGN: The temperature distribution was determined by using a three-dimensional finite element analysis. The tooth was assumed to have undergone an endodontic treatment before the application. Heat applications of 200 degrees C and 100 degrees C were considered. RESULTS: By using the virtual model and the simulation technique, the maximum temperature in the periodontal ligament was found to be 43.5 degrees C. CONCLUSIONS: Within the assumptions and the limitations of the study, it was determined that the simulation of System B technique created no potentially harmful levels of temperature throughout the maxillary canine model.  相似文献   
5.

Background  

The Turkish Association of Medicine founded a Continuing Medical Education Accreditation Committee in 1993 to evaluate and accredit scientific meetings and publications. The aims of this project were to raise the standards of meetings and to introduce compulsory revalidation and re-certification for physicians in Turkey.  相似文献   
6.
BACKGROUND: This study aimed to investigate whether exposure to sunflower pollen (Helianthus annuus) increases both sensitization and respiratory symptoms, and whether or not it affects lung functions in sunflower processing workers. METHODS: The largest sunflower processing factories in the Thrace region of Turkey participated in this study. Workers from the units directly exposed to sunflower seed enrolled as the study group (n = 102) and workers who were not directly exposed to Helianthus annuus pollen (n = 102) were the control group. Detailed questionnaires covering respiratory and allergic symptoms were completed, and skin prick tests and lung function tests were performed. RESULTS: We found a very high rate (23.5%) of sensitization to Helianthus annuus in the study group compared to the controls (P<0.001). Logistic regression analysis showed that the risk of sensitization to H. annuus was increased 4.7-fold (odds ratio = 4.17, 95%) confidence interval = 1.3-16.7) if subjects were exposed to sunflower pollen in the workplace. While asthmatic symptoms and allergic skin diseases were not different between the two groups, workers in the study group had a higher rate of allergic rhinitis and conjunctivitis (P<0.05). We found that pulmonary function was significantly impaired in the study group (P<0.01). Using a multivariate analysis model, inclusion in the study group was found to be a predictive factor for impairment of lung function (P=0.002). CONCLUSIONS: We conclude that sunflower pollen has high allergenic potential, especially when there is close contact, and exposure to sunflower pollen in the workplace can result in impairment in lung function.  相似文献   
7.

This study aims to synthesize and characterize an economical and ecological adsorbent with high adsorption capacity. For this purpose, the peanut shells (Pistacia vera L.) were modified chemically. After the synthesis of activated carbon (AC), the optimum conditions for enrichment steps were performed using parameters: pH and contact time for uranium in the model solutions. The measurements were carried out by inductively coupled plasma-mass spectrometry (ICP-MS). From the shapes of the BET isotherms, the AC obtained exhibits type I. The study indicated that the surface area and total pore volume of the AC were found to be 679.9 m2 g−1 and 0.31 cc g−1, respectively. The adsorption capacity was found to be 260 mg g−1. The optimum pH was found to be 6.0 for enrichment using the AC obtained by sulfuric acid as a chemical-modifier. The optimized method was applied to enrichment of U at ppb levels in the model solutions.

  相似文献   
8.
BACKGROUND: Cauda equina syndrome occurring as a result of spontaneous spinal subarachnoid hemorrhage (SAH) from a spinal tumor is reported to be rare. CASE DESCRIPTION: A 28-year-old woman presented at our clinic with a history of severe back pain for 10 days, progressive paraparesis, and urinary retention. Her physical examination revealed a mass located intradurally at the level of L1-2 and a massive SAH. An L1-L2, laminectomy and a hemilaminectomy from D9 to D12 were performed and the SAH was evacuated and the cord was decompressed. CONCLUSION: At the first year follow-up, her restricted dorsal and plantar flexion continued. Post-gadolinium magnetic resonance imaging revealed no mass.  相似文献   
9.
OBJECTIVE: The aim of this study was to investigate whether the ovulation induction has relation with postneoplastic lesions. MATERIALS AND METHODS: Seventy-eight female, 90-day-old rats were enrolled for the trial. They were divided into three groups. In the first group, 13 rats received one cycle of ovulation induction with Follitropin Beta and human chorionic gonadotropin. The second group of 13 rats received three cycles of ovulation induction, and the third study group consisted of 13 rats which received six cycles of ovulation induction. Each group had a control group consisting of same number of rats that had not received ovulation induction. At the 12th month after the ovulation induction protocols ended, rat ovaries were extirpated for histopathological examination. In histopathological examination, malignant lesions, ovarian cyst and cyst diameter, epithelial stratification, epithelial tufting, mitotic index, polymorphism of epithelial cells and nucleus, epithelial cell nuclear diameter, chromatin density nuclear atypia, and mitotic activity in ovarian cyst epithelium were evaluated. RESULTS: No malignant ovarian lesion was found in the three groups. Ovarian cyst development was most frequent in the rats that underwent six cycles of ovulation induction. Epithelial stratification and tufting were most frequent in the rats which underwent ovulation induction six times. Significant difference was found between induction and control groups in second and third groups for cellular and nuclear polymorphism, presence of nucleolus, and nuclear chromatin density. CONCLUSIONS: Although development of malignant lesion were not found in any of the rat ovaries after ovulation induction, increase in the prevalence of epithelial dysplasia especially with increase in the number of induction cycles shows that some ovarian pathologies can occur subsequent to ovulation induction.  相似文献   
10.
A 52 year-old male patient with idiopathic hepatic cirrhosis complaining of diarrhea and weakness was accepted to the gastroenterology clinic. In order to find out the causative etiologic agent of diarrhea, stool samples were examined by different methods and stained using modified Kinyoun's acid-fast stain. Following examination, approximately 9 microns diameter, acid-fast variable wrinkled spheres were seen and diagnosed as Cyclospora cayetanensis. Confirmation of the diagnosis was established by fluorescent microscope (380 to 420 nm excitation filter), which showed bright green to intense blue autofluorescent oocysts. It has been shown that, Cyclospora cayetanensis is a coccidian parasite mainly found in immunocompromised patients and that it may be the agent of prolonged diarrhea. Only three cyclosporiosis cases have been previously reported in our country; all three cases were AIDS patients. We report here a further case of Cyclospora cayetanensis infection in a patient with hepatic cirrhosis and we consider that this is the first case, which was reported in hepatic cirrhosis.  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