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   144929篇
  免费   33511篇
  国内免费   1253篇
耳鼻咽喉   2784篇
儿科学   4187篇
妇产科学   3538篇
基础医学   9478篇
口腔科学   5707篇
临床医学   31026篇
内科学   34241篇
皮肤病学   4169篇
神经病学   17595篇
特种医学   4778篇
外科学   22407篇
综合类   564篇
现状与发展   40篇
一般理论   69篇
预防医学   19170篇
眼科学   2781篇
药学   4341篇
中国医学   95篇
肿瘤学   12723篇
  2024年   579篇
  2023年   5536篇
  2022年   2091篇
  2021年   5096篇
  2020年   6618篇
  2019年   3957篇
  2018年   9051篇
  2017年   8708篇
  2016年   9421篇
  2015年   9669篇
  2014年   12493篇
  2013年   14786篇
  2012年   8220篇
  2011年   7876篇
  2010年   8955篇
  2009年   10870篇
  2008年   6498篇
  2007年   5307篇
  2006年   6341篇
  2005年   4680篇
  2004年   3821篇
  2003年   3188篇
  2002年   2845篇
  2001年   2051篇
  2000年   1313篇
  1999年   1919篇
  1998年   2411篇
  1997年   2165篇
  1996年   2173篇
  1995年   1865篇
  1994年   1217篇
  1993年   1023篇
  1992年   826篇
  1991年   714篇
  1990年   599篇
  1989年   609篇
  1988年   574篇
  1987年   425篇
  1986年   398篇
  1985年   348篇
  1984年   308篇
  1983年   353篇
  1982年   261篇
  1981年   240篇
  1980年   155篇
  1979年   96篇
  1978年   160篇
  1977年   151篇
  1976年   114篇
  1972年   93篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
871.
PURPOSE: The purpose of the study was to evaluate the incidence of incontinence pad use among patients admitted to medical wards, the reasons why nurses decide to use an incontinence pad, the extent to which the use of pads is avoidable, and the outcome of inappropriate pad use after discharge from the hospital. METHODS: A prospective cohort study was conducted; patients admitted to medical wards were observed during hospitalization and a 7-day follow-up period after discharge. SUBJECTS AND SETTING: The study was conducted in 2 acute-care units in Northern Italy. All new patients admitted to the units were recruited. RESULTS: At the time of admission to the hospital, in addition to the 120 patients who already used incontinence pads, there was a 34% incidence of new cases (98/286). The most frequent reason why nurses decided to use this aid was incontinence caused by space-time disorientation, followed by limited mobility, incontinence, patient request, nursing shortage, and involuntary urine leakage not perceived by patient. Seventy patients out of 208 used incontinence pads unnecessarily for a total of 544 days. CONCLUSIONS: Decisions about the use of the incontinence pads are not always consistent with research-based or literature-based suggestions. Nurses should develop clinical guidelines or protocols for the appropriate use of incontinence pads.  相似文献   
872.
A case history of a 32-year-old female Olympic pole vaulter is reported. Two months after endoscopic surgery for chronic Achilles tendinopathy, she developed a keloid lesion on the hindfoot area. She was treated with corticosteroids, topical and intralesional injections. A satisfactory result was obtained, and the athlete was able to resume her competitive activity at 5 months after surgery. Keloid pathogenesis, treatment, and prevention are briefly discussed.  相似文献   
873.
874.
875.
This paper reviews the literature on colorectal cancer from a sex and gender-based perspective. Colorectal cancer is a major cause of death in the developed world, with rates increasing in developing countries. Although described by some writers as an ‘equal opportunity’ disease, it presents more risk to men than women. Both biological, or sex-linked factors, and gender-linked factors play a part in the aetiology of the disease, while gender differences in the use of screening and treatment also help shape the mortality gap between women and men for this condition. Without an appreciation of the part played by sex and gender in the risk of colorectal cancer, and without a gender-sensitive approach to screening in particular, it is possible that the mortality gap between men and women for this condition will widen in the future.  相似文献   
876.
Hypertrophic scars (HS) are a consequence of abnormal wound healing. We examined fatty acids that are contained within, and participate in, every reaction through the membrane; then, we analyzed the percentage composition of the fatty acids in deepithelialized normal dermis (ND) and HS. In vivo HS samples were obtained from six patients undergoing surgical excision, and ND samples from five patients undergoing skin grafting surgery for excess. In vitro, cultured fibroblasts from HS and ND were also analyzed. The percentage composition of fatty acids extracted from all the samples was analyzed. In vivo, arachidonic acid (20:4) was significantly more abundant in HS than in ND, in the phospholipids from both whole tissue and cell membranes. In vitro, there were no significant differences among ND, HS, and 10% fetal calf serum. The results suggest that HS formation does not necessarily involve simple excess of 20:4; however, there are considerable differences in the percentage composition of 20:4 between ND and HS. Arachidonic acid probably participates in the formation and maintenance of HS, whereas in vitro cultured fibroblasts are affected largely by fetal calf serum.  相似文献   
877.
Morphometric data based on skin wounding offer important information for the characterization of the phenotype of transgenic mouse models. The goal of this study was the comparison of technical procedures concerning wounding, processing, and evaluation of samples in different mouse strains. The multitissue array technique was used to estimate its adaptability for standardized analysis in wound healing. Skin wounds between days 1 and 14 after wounding were analyzed. The influence of mouse strain (C57BI/6 vs. FVB/N mice), sex, size of the punch biopsies, and preparation of the tissue sections was investigated on 94 mice. The parameters distance between the migration tongues (deltaMT) and surface not covered by epithelium were evaluated to describe the reepithelialization, and the distance between the adnexa was chosen to measure wound contraction. In addition, the techniques to measure the area of granulation tissue (GT) were evaluated. The data illustrate the requirement of standardized conditions for skin wound-healing experiments and demonstrate that histological preparation in serial sections is mandatory to detect slight differences in wound contraction. For the analysis of cellular composition in GT, multitissue arrays are useful tools in wound-healing studies.  相似文献   
878.
We determined an operational value for the lumped constant to be used in measurements of the local rate of cerebral glucose use (lCMR(glc)) with FDG in normal adult male rats. METHODS: The standard quantitative autoradiographic method was used with 2-deoxy-d-(14)C-glucose ((14)C-DG) and with (14)C-FDG in awake normal adult male rats. Timed arterial blood samples were drawn for 45 min after the bolus and assayed for plasma glucose and (14)C concentrations. At the end of the 45-min experimental period, the rats were killed, and their brains were removed and divided in half sagittally. One hemisphere was immediately frozen and assayed for local (14)C concentrations by quantitative autoradiography; the other was weighed, homogenized in t-octylphenoxypolyethoxyethanol solution, and assayed for (14)C concentrations in the whole brain by liquid scintillation counting. Paired rats (3 pairs), one in each pair receiving (14)C-DG and the other receiving (14)C-FDG, were studied in parallel on the same day. Additional unpaired animals (n = 8) were studied with either (14)C-DG or (14)C-FDG but not in parallel on the same day. To calculate the lCMR(glc) in rats studied with (14)C-FDG, the rate constants for (14)C-FDG were estimated from the (14)C-DG values determined for rats and the (14)C-FDG/(14)C-DG ratios determined for humans. In all of the rats studied with either (14)C-DG or (14)C-FDG, the lCMR(glc) was first calculated in 12 representative brain structures with the lumped constant of 0.48 previously determined for (14)C-DG in rats. The ratio of the lCMR(glc) thus determined with (14)C-FDG to that determined with (14)C-DG for each structure was then multiplied by the lumped constant for (14)C-DG to estimate the lumped constant for (14)C-FDG. The lCMR(glc) and the lumped constant for FDG in the brain as a whole were similarly estimated from the tracer concentrations in the brain homogenates. RESULTS: The mean values for the lumped constant for FDG were found to be 0.71 and 0.70 in the autoradiographic assays and the assays with brain homogenates, respectively. CONCLUSION: The appropriate value for the lumped constant to be used in determinations of the lCMR(glc) in normal adult male rat studies with (18)F-FDG and small-animal PET scanners is 0.71.  相似文献   
879.
880.
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