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   851篇
  免费   44篇
  国内免费   2篇
耳鼻咽喉   38篇
儿科学   36篇
妇产科学   33篇
基础医学   63篇
口腔科学   69篇
临床医学   76篇
内科学   193篇
皮肤病学   7篇
神经病学   51篇
特种医学   16篇
外科学   120篇
综合类   11篇
一般理论   1篇
预防医学   42篇
眼科学   52篇
药学   32篇
中国医学   21篇
肿瘤学   36篇
  2023年   4篇
  2022年   9篇
  2021年   11篇
  2020年   10篇
  2019年   14篇
  2018年   23篇
  2017年   23篇
  2016年   38篇
  2015年   36篇
  2014年   34篇
  2013年   53篇
  2012年   68篇
  2011年   67篇
  2010年   48篇
  2009年   38篇
  2008年   51篇
  2007年   77篇
  2006年   63篇
  2005年   56篇
  2004年   42篇
  2003年   37篇
  2002年   33篇
  2001年   17篇
  2000年   9篇
  1999年   7篇
  1998年   2篇
  1997年   4篇
  1996年   3篇
  1994年   3篇
  1993年   1篇
  1992年   7篇
  1991年   5篇
  1989年   2篇
  1979年   1篇
  1974年   1篇
排序方式: 共有897条查询结果,搜索用时 15 毫秒
1.
Potential advantages of paediatric day-surgery are cost saving, improved utilization of staff and hospital facilities, and reduction of stress for the paediatric patient and their family. A successful programme requires careful case selection, full operating and anaesthetic facilities and good follow-up. Current practice is reviewed with regard to initial assessment, preparation for surgery and overall management during the day admission. To provide information on how patients and their parents experience essential aspects of daycare paediatric surgery, a questionnaire-based study on parental satisfaction of paediatric day-surgery was performed. Most children were back to normal, within a few days. Recovery from paediatric day-surgery was rapid and the overall level of parent satisfaction was high.  相似文献   
2.
Leukocyte arylsulphatase A (AS-A) was shown to be significantly high in newly-diagnosed breast cancer patients. Previous reports imply a connection between serum interleukin-6 (IL-6) and breast cancer, possibly through a modulation of enzymes involved in estrogen synthesis. Abnormal distribution of heparan sulphate proteoglycans (HSPGs) in malignant breast epithelial cells suggests that they play a key role in the regulation of cell growth. Estradiol is believed to be effective in modulating glycosaminoglycans (GAGs) and their depolymerizing enzymes. Therefore, in this study, attempts were made to evaluate the activity of leukocyte arylsulphatase A, serum interleukin-6, urinary GAGs and heparan sulphate (HS) in response to tamoxifen (TAM) therapy in mastectomised breast cancer patients. Thirty-four patients (aged 30-82 years) were administered TAM (20 mg twice daily). Blood and urine samples of each patient were collected three times (at the beginning, and in third and sixth month of TAM therapy), and biochemical parameters were measured. There was no difference between baseline leukocyte AS-A activity and that measured after three months. At the end of six months, enzyme activity was significantly higher than the former values (p=0.022), but within the reference intervals reported in the literature. Although this increase might imply a normalization, the duration of TAM therapy is not long enough to make a decision about either regression or aggravation of the disease. TAM did not have any effect on serum IL-6, urinary HS and GAG levels which may be due to insensitivity of these variables to TAM during the short period of therapy. Both urinary GAG and HS levels measured at sixth month exhibited a positive correlation with the baseline level of leukocyte AS-A (p=0.005 and 0.009, respectively), suggesting that positive responses to the drug might be seen in patients with low AS-A activity.  相似文献   
3.
Abstract Fructosamine assay, which is used in diagnosing and monitoring diabetic patients, is compared with the hemoglobin and plasma glucose assays in children and adolescent insulin-dependent diabetes mellitus patients. We demonstrated that the gingival index scores were correlated with fructosamine values in insulin-dependent diabetes mellitus patients but not in non-diabetic controls. We also found that there was no correlation between gingivitis scores and fasting plasma glucose and HbAlc values. Periodontitis was found to be rare in diabetic children and adolescents.  相似文献   
4.
Based on direct sequencing information from 5UTR and NS5B regions, we identified subtype 1b as a predominant hepatitis C virus genome in Turkey, which affected more than 91% of 79 patients studied. Next, the full genome sequence of a Turkish 1b isolate was obtained by the cloning of polypeptide-encoding region into 7 overlapping fragments. Turkish 1b isolate, which was named HCV-TR1, comprises 9361 nucleotides, including 306 nucleotides of 5UTR, a single long open reading frame of 9033 nucleotides, and 22 nucleotides of 3UTR. When compared to HCV 1b polypeptide sequences available at GenBank, the predicted polypeptide displayed a total of 36 amino acid substitutions, of which 16 was specific for HCV-TR1 isolate. Despite these changes, major structural and functional motifs of HCV proteins were maintained in HCV-TR1. In contrast, HCV-TR1 displayed amino acid substitutions in 6 out of 9 major cytotoxic T-cell epitopes. These data suggest that HCV-TR1 encodes functionally intact viral proteins, but it also encodes altered viral epitopes, which may affect host immune-response.  相似文献   
5.
Situated on mature B lymphocytes, CDw75 antigen is a sialylated carbohydrate epitope generated by the enzyme beta-galactosyl alpha-2,6-sialyltransferase. Although CDw75 antigen expression was found to be correlated with aggressive behaviour of tumour cells in gastric adenocarcinomas, its prognostic role still remains unknown. The objective of this study was to determine the value of CDw75 antigen expression as a marker of the metastatic potential and prognosis of gastric adenocarcinomas. CDw75 antigen expression was evaluated immunohistochemically in 64 tumours and their nodal metastases. The correlation was analysed between CDw75 antigen expression and selected clinicopathological variables, including survival. Positive staining was detected in 31 cases. Non-neoplastic gastric mucosa was consistently negative. CDw75 expression was correlated with larger tumour size (p<0.006), infiltrative growth pattern (p<0.044), advanced stage (p<0.0006), and positive lymph nodes (p<0.0003).The overall survival rate of patients with CDw75 expression was 28%, which was significantly worse than that of patients without CDw75 expression (53%) (p<0.0005). Multivariate analysis showed that CDw75 expression was an independent prognostic indicator, together with the growth pattern of the tumour. These results indicate that immunohistochemical detection of CDw75 antigen expression may be a good indicator of metastatic potential and of prognosis in patients with gastric carcinomas.  相似文献   
6.
The effects of air pollution on health are of concern worldwide. There are several pollutants of concern, among which are sulfur dioxide, total suspended particulates, nitrogen dioxide, carbon monoxide, and volatile organic chemicals. In several studies, researchers investigated the effects of those pollutants on lung and nasal functions, although in very few studies has nasal function been addressed. We evaluated the effects of air pollution on the prevalence of rhinitis in a metropolitan of Turkey, Istanbul. Until 1994, coal was used for both domestic heating and industrial processes in the city. Consequently, sulfur dioxide and total suspended particulate concentrations in the ambient air exceeded limits of air-quality standards. In recent years, especially during the early 1990s, hazardous air pollution levels were reached in Istanbul. In this study, we evaluated the incidence of rhinitis before and after installation of a natural-gas network in a polluted area of the city. In 1994, 62.5% of the individuals studied suffered from rhinitis, compared with 51% of the sample in 1996 (p < .05). Age, gender, smoking status, heating source, nor household crowding significantly affected this outcome. The findings strengthened the role of pollutant levels as risk factors for rhinitis.  相似文献   
7.
The efficacy of intra-arterial infusion chemotherapy (IACT) as the first step in a combined modality therapy in the treatment of locally advanced breast cancer was evaluated in a prospective clinical study consisting of 18 patients, 15 with stage IIIB, and three with stage IV breast cancer. A combined chemotherapy using adriamycin, mitomycin C and 5-Fluorouracil were administered at 3-week intervals until sufficient regression was achieved. Objective response rate was 66.6%. Among the 14 patients who received IACT for induction, plus surgery, simultaneous adjuvant chemotherapy and radiotherapy, 7 were disease-free at a mean of 19.5 (range 4-42) months. Six patients developed various relapses at a mean of 20.6 (range 12-28) months. IACT was found to be quite effective in local control. The early systemic relapse continues to be a serious problem that needs further intervention.  相似文献   
8.
The aim of this prospective study was to determine the diagnostic value of Tc-99m MDP scintimammography (SMG) for the detection of breast cancer in patients with breast masses and to compare the results with Tc-99m MIBI scintimammography. Twenty patients, categorized as suspicious, positive or benign for breast cancer according to the mammographic findings were included in the study. Dual phase Tc-99m MIBI and Tc-99m MDP SMG were performed in the prone lateral position within 5 days of each other. Although early and late Tc-99m MIBI SMG showed equal (90.4%) sensitivity, the specificity of late Tc-99m MIBI (87.5%) was found superior to early (62.5%) imaging. The overall sensitivity and specificity of early Tc-99m MDP SMG were 71.4% and 62.5%, respectively. Although late Tc-99m MDP imaging showed 100% specificity, its sensitivity was only 23.8%. In the patients with palpable masses, both early Tc-99m MDP and Tc-99m MIBI showed equal sensitivity (100%), but the sensitivity of early Tc-99m MIBI (37.5%) was found slightly higher than Tc-99m MDP (25.0%) for nonpalpable breast lesions. The sensitivity of Tc-99m MIBI and Tc-99m MDP SMG in detecting metastatic axillary involvement was 66.6% and 50%, respectively. High sensitivity and specificity together with its low cost, easy availability and the possibility of detecting bone metastases seems to make Tc-99m MDP a contributive agent in the evaluation of breast lesions as an alternative to Tc-99m MIBI.  相似文献   
9.
10.
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