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   1622篇
  免费   91篇
  国内免费   3篇
耳鼻咽喉   10篇
儿科学   32篇
妇产科学   6篇
基础医学   206篇
口腔科学   27篇
临床医学   120篇
内科学   437篇
皮肤病学   11篇
神经病学   95篇
特种医学   74篇
外科学   219篇
综合类   13篇
预防医学   230篇
眼科学   50篇
药学   37篇
中国医学   2篇
肿瘤学   147篇
  2023年   4篇
  2022年   6篇
  2021年   15篇
  2020年   7篇
  2019年   18篇
  2018年   26篇
  2017年   25篇
  2016年   19篇
  2015年   32篇
  2014年   27篇
  2013年   43篇
  2012年   82篇
  2011年   61篇
  2010年   83篇
  2009年   61篇
  2008年   87篇
  2007年   148篇
  2006年   106篇
  2005年   102篇
  2004年   62篇
  2003年   62篇
  2002年   63篇
  2001年   49篇
  2000年   47篇
  1999年   60篇
  1998年   29篇
  1997年   26篇
  1996年   18篇
  1995年   14篇
  1994年   21篇
  1993年   19篇
  1992年   30篇
  1991年   31篇
  1990年   26篇
  1989年   26篇
  1988年   24篇
  1987年   20篇
  1986年   18篇
  1985年   25篇
  1984年   14篇
  1983年   15篇
  1982年   8篇
  1981年   5篇
  1980年   5篇
  1979年   5篇
  1978年   6篇
  1977年   6篇
  1976年   7篇
  1975年   7篇
  1971年   3篇
排序方式: 共有1716条查询结果,搜索用时 0 毫秒
71.
A 4 year old girl treated with a standard chemotherapy protocol for acute lymphoblastic leukaemia developed hepatic candidosis during the consolidation phase. This relapsed after a prolonged course of amphotericin B and flucytosine. An eight week course of liposomal amphotericin produced a marked clinical improvement which was sustained for one year. A subsequent relapse was associated with transformation to myelodysplastic leukaemia.  相似文献   
72.
In a case-control study in The Netherlands, we observed a significantly lower consumption of fermented milk products (predominantly yogurt and buttermilk) among 133 incident breast cancer cases as compared to 289 population controls (mean +/- SD among users only, 116 +/- 100 versus 157 +/- 144 g/day; P less than 0.01). The age-adjusted odds ratio of daily consumption of 1.5 glasses (greater than or equal to 225 g) of fermented milk versus none was 0.50 (95% confidence interval, 0.23-1.08). When fermented milk was entered as a continuous variable (per g) in either age-adjusted or multivariate analysis, the odds ratio expressed per 225 g was 0.63 (multivariate-adjusted 95% confidence interval, 0.41-0.96). After multivariate adjustment for intake of fat and other confounders, a statistically significant decrease in breast cancer risk was also observed for increasing intake of Gouda cheese. The multivariate-adjusted odds ratio expressed per 60 g of this fermented product was 0.56 (95% confidence interval, 0.33-0.95). For daily intake of milk, no statistically significant differences were observed between cases and controls. These results support the hypothesis that high consumption of fermented milk products may protect against breast cancer.  相似文献   
73.
The authors developed a simple and sensitive, fully validated HPLC-UV method for the determination of both 5-FU and its metabolite DHFU in small-volume plasma samples. The analytes were separated on a 4.6 x 250 mm ID Atlantis dC18 5-microm column with isocratic elution at room temperature. Chlorouracil was used as internal standard. The analytes were detected with an UV diode array detector. DHFU was detected at 205 nm, 5-FU at 266 nm, and chlorouracil at both wavelengths. The limits of quantification in plasma were 0.040 mug /mL for 5-FU and 0.075 microg/mL for DHFU. Linearity, accuracy, precision, recovery, dilution, freeze-thaw stability, and stability in the sample compartment were evaluated. The method appeared linear over a range from 0.04 to 15.90 microg/mL for 5-FU and from 0.075 to 3.84 microg/mL for DHFU. The method appeared very suitable for therapeutic drug monitoring and pharmacokinetic studies of 5-FU because of its simple extraction and small sample volume. Problems in earlier published methods with interfering peaks and variable retention times were overcome. The method appeared also to be suitable for detection of uracil and its metabolite dihydrouracil in plasma.  相似文献   
74.
The aim of this study was to assess if the pain observation scale for young children (POCIS) and the visual analogue scale (VAS) are reliable and valid instruments to measure procedural and background pain in burned children aged 0-4 years. Burn care nurses (n=73) rated pain from 24 fragments of videotaped children during wound care procedures and during periods of rest using the POCIS and the VAS. Intraclass correlations were used to assess inter-rater and intra-rater reliability for the POCIS and the VAS. Internal consistency for POCIS was assessed by Cronbach's alpha. The POCIS has shown poor to moderate inter-rater reliability, moderate to good intra-rater reliability and an acceptable internal consistency. The VAS turned out to have poor inter-rater reliability and poor to moderate intra-rater reliability. Due to poor results of inter-rater reliability in both scales, construct validation is left undone until more acceptable results are obtained. Factors explaining the results are the large number of raters, the manner they were trained and a lack of variation between pain classes in video fragments. Although not all results were satisfying, an easy to use scale as POCIS has promising qualities and deserves further reliability research.  相似文献   
75.
76.
OBJECTIVE: To outline the rationale, objectives and strategies used in a systematically designed research programmme to study specific weight gain-inducing behaviours, their social-psychological as well as environmental determinants, and the effects of interventions aimed at the prevention of weight gain. DESIGN: The evidence for potential behavioural determinants and strategies to prevent weight gain was reviewed, and the methods applied within the Netherlands Research programme weight gain prevention (NHF-NRG) project were described. The project is designed according to the Intervention Mapping protocol. SETTING: The Netherlands. SUBJECTS: The main target groups are (a) adolescents (12-16 y) in secondary school, (b) young adults (20-40 y) at the workplace and (c) recently retired people (55-65 y) at home. INTERVENTIONS: Each intervention includes an individual component, in which computer-tailored information is provided. Additionally, interventions are aimed at changing environmental components. RESULTS: The short-term results of this project can be expected by the beginning of 2005. Guidelines for nationwide weight gain prevention, based on this research programme, will become available in 2007. CONCLUSIONS: Based on the few interventions that were evaluated to date, no robust conclusions can be drawn regarding the effectiveness of obesity prevention. The systematic and multidisciplinary design of the NHF-NRG programme enables the identification of potentially effective methods and strategies for the prevention of weight gain.  相似文献   
77.
The aim of this study was to develop a tool that can aid nurse managers in planning nurse staffing levels and assessing workload in hematology-oncology wards. A task-oriented method based on a time-and-motion study was used. Three general nursing procedures and 7 specific oncologic and hematologic activities were clocked. It was checked in the charts of the patient, for each day of the admission, how often selected nursing procedures were performed. Then total amount of time needed for each patient was calculated. Data from 29 admissions to the ward were analyzed and divided into 5 categories based upon the treatment performed during that admission. The categories chosen were: autologous stem cell transplantation, allogeneic stem cell transplantation, graft versus host reaction, leukemia treatment, and chemotherapy for solid neoplasm. The results obtained are an estimate of the different daily workload that is required for these categories of patients in selected nursing procedures.  相似文献   
78.
6-Mercaptopurine (6MP) levels in serum of dogs were studied after long-term oral administration and intravenous injection. During long-term daily oral administration of 50 mg of 6MP, more or less constant levels of 6MP have been found after 1-3 weeks. After stopping administration of the drug, 6MP concentrations remained constant for a further period of 3-6 weeks and then declined within 1-2 weeks below the limit of detection. I.v. bolus injections of 50 mg of 6MP resulted in concentration v. time curves which fitted into an open two-compartment pharmacokinetic model. Half-life times were in a range of 13-21 and 125-151 min, respectively. Peak concentrations were from 2,500 to 10,500 nmol/l. Our data on i.v. push injections with a customary clinical dose revealed peak concentrations which were low in comparison to the concentrations used in in vitro studies by Tidd and Paterson to achieve maximal cell-kill. Moreover, the half-life times of the 6MP after i.v. bolus injections are short, so prolonged high plasma concentrations are not obtained by i.v. bolus injections. We suggest that prolonged infusions of 6MP at relatively high dose rates should result in higher and persisting plasma concentrations and so should promise a more potent antitumour activity.  相似文献   
79.
80.
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