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   2872篇
  免费   208篇
  国内免费   15篇
耳鼻咽喉   17篇
儿科学   104篇
妇产科学   49篇
基础医学   550篇
口腔科学   51篇
临床医学   261篇
内科学   454篇
皮肤病学   114篇
神经病学   289篇
特种医学   139篇
外科学   211篇
综合类   22篇
预防医学   235篇
眼科学   58篇
药学   248篇
中国医学   9篇
肿瘤学   284篇
  2023年   32篇
  2022年   96篇
  2021年   138篇
  2020年   86篇
  2019年   99篇
  2018年   122篇
  2017年   90篇
  2016年   88篇
  2015年   95篇
  2014年   105篇
  2013年   154篇
  2012年   223篇
  2011年   223篇
  2010年   144篇
  2009年   103篇
  2008年   169篇
  2007年   184篇
  2006年   131篇
  2005年   146篇
  2004年   98篇
  2003年   93篇
  2002年   87篇
  2001年   19篇
  2000年   22篇
  1999年   15篇
  1998年   14篇
  1997年   14篇
  1996年   6篇
  1995年   13篇
  1994年   8篇
  1993年   8篇
  1992年   8篇
  1991年   7篇
  1990年   12篇
  1989年   10篇
  1988年   20篇
  1987年   17篇
  1986年   7篇
  1985年   21篇
  1984年   10篇
  1983年   9篇
  1982年   8篇
  1980年   6篇
  1979年   19篇
  1978年   14篇
  1977年   14篇
  1976年   15篇
  1975年   13篇
  1974年   18篇
  1973年   14篇
排序方式: 共有3095条查询结果,搜索用时 0 毫秒
21.
Abdominal and pelvic computed tomography (CT) scans were performed on 17 patients with suspected complications of Crohn's disease. CT was superior to conventional barium studies and colonoscopy in demonstrating mural, serosal, and mesenteric pathology such as bowel wall thickening (100%), abscess (59%) and phlegmon (6%) formation, and fibrofatty proliferation of the mesentery (41%). While not advocated as the primary means of evaluating Crohn's disease, CT can provide information vital to the management of complications of this disease.  相似文献   
22.
Blocking the CD40‐CD154 pathway prevents allograft rejection and induces donor‐specific tolerance in various experimental models. However, the translation to clinical studies has been hampered by unexpected thromboembolic complications of CD154‐blocking antibodies. Thus, blocking CD40 instead is now considered as an alternative strategy. Here, we evaluated the role of donor CD40 in allospecific T‐cell responses in vitro and in an in vivo model for renal transplantation. Fully MHC‐mismatched allografts from CD40‐deficient donors displayed better renal function than wild type. These functional data correlated with a lower level of apoptosis in renal tubular epithelial cells and higher expression of PD‐L1, which is most probably because of a reduced Th17 response in recipients of a CD40‐deficient donor. This hypothesis was supported in vitro, where donor CD40 expression was important for the induction of direct allospecific T‐cell responses. Especially the induction of Th17 cells was critically dependent on donor CD40. IL‐17A in conjunction with interferon‐γ in turn rendered renal tubular epithelial cells to a more costimulatory state by upregulating CD40 and downregulating PD‐L1 expression. In conclusion, CD40 blockade not only reduces the allospecific T‐cell responses, but might also lead to protection of tubular epithelium from apoptosis and thereby preserve kidney allograft function.  相似文献   
23.
24.
BackgroundMinimal invasive surgery (MIS) is increasingly used for the correction of congenital diaphragmatic hernia (CDH) and esophageal atresia (EA). It is important to master these complex procedures, preferably preclinically, to avoid complications. The aim of this study was to validate recently developed models to train these MIS procedures preclinically.MethodsTwo low cost, reproducible models (one for CDH and one for EA) were validated during several pediatric surgical conferences and training sessions (January 2017–December 2018), used in either the LaparoscopyBoxx or EoSim simulator. Participants used one or both models and completed a questionnaire regarding their opinion on realism (face validity) and didactic value (content validity), rated on a five-point-Likert scale.ResultsOf all 60 participants enrolled, 44 evaluated the EA model. All items were evaluated as significantly better than neutral, with means ranging from 3.7 to 4.1 (p < 0.001). The CDH model was evaluated by 48 participants. All items scored significantly better than neutral (means 3.5–3.9, p < 0.001), with exception of the haptics of the simulated diaphragm (mean 3.3, p = 0.054). Both models were considered a potent training tool (means 3.9).ConclusionThese readily available and low budget models are considered a valid and potent training tool by both experts and target group participants.Type of studyProspective study.Level of evidenceLevel II.  相似文献   
25.
Hypoglycemia limits optimal glycemic management of patients with type 1 diabetes mellitus (T1DM). Fear of hypoglycemia (FoH) is a significant psychosocial consequence that negatively impacts the willingness of T1DM patients to engage in and profit from the health benefits of regular physical activity (e.g., cardiometabolic health, improved body composition, cardiovascular fitness, quality of life). Technological advances, improved insulin regimens, and a better understanding of the physiology of various types of exercise could help ameliorate FoH. This narrative review summarizes the available literature on FoH in children and adults and tools to avoid it.  相似文献   
26.
PURPOSE: To evaluate fundus photographic image analysis combining automated detection of red lesions, bright lesions, and image quality as a means of identifying treatment-requiring diabetic retinopathy in a screening population of diabetic patients. METHODS: This was a retrospective cross-sectional study of 106 patients from a diabetic retinopathy screening clinic referred for photocoagulation treatment in the period from January 1996 to May 2002 on the basis of mydriatic 60-degree 35-mm color transparency fundus photography. One fovea-centered fundus photograph and one centered nasal of the optic disk from each of a subject's two eyes was selected for digitization and analyzed using a previously tested computerized red-lesion detection algorithm in combination with a new algorithm for detection of bright lesions and image quality. The algorithm was calibrated on an independent set of fundus photographs. RESULTS: Automated red-lesion detection identified 104 of 106 patients requiring photocoagulation treatment, whereas bright-lesion detection identified only 91 of the 106 patients. Two patients who were not identified by either lesion detection algorithm were automatically detected as having poor image quality in one or both eyes. In the study sample, the risk of missing treatment-requiring retinopathy patients from being detected was 0.0% (estimated CI(95) 0.0-3.4%). CONCLUSIONS: The combination of automated detection of red lesions and poor image quality identified all treatment-requiring diabetic retinopathy patients in the study sample. No additional information was contributed by the automated bright-lesion detection.  相似文献   
27.
Immunohistologically linear IgA disease presents with unambiguous features, whereas clinical manifestations are variable. It sometimes shows similarity to other bullous dermatoses such as bullous pemphigoid and dermatitis herpetiformis. A 73 year old female patient was referred with the diagnosis of bullous pemphigoid. One day after admission clinical examination revealed the classical features of Stevens-Johnson syndrome (SJS): widespread confluent atypical target lesions, partly raised, partly flat with central blisters, and erythematous spots, but few typical targets, as well as blisters and large areas of skin detachment on her back and buttocks, accompanied by erosions of the oral and genital mucosa. Direct immunofluorescence performed on peri-lesional skin showed linear deposition of IgA along the basement membrane zone, leading to the diagnosis of linear IgA disease of adults. Our case report shows that linear IgA disease may present with the clinical pattern of SJS.  相似文献   
28.

Background

Survivors of brain tumors have a high risk for a wide range of cognitive problems. These dysfunctions are caused by the lesion itself and its surgical removal, as well as subsequent treatments (chemo‐ and/or radiation therapy). Multiple recent studies have indicated that children with brain tumors (BT) might already exhibit cognitive problems at diagnosis, i.e., before the start of any medical treatment. The aim of the present study was to investigate the baseline neuropsychological profile in children with BT compared to children with an oncological diagnosis not involving the central nervous system (CNS).

Methods

Twenty children with BT and 27 children with an oncological disease without involvement of the CNS (age range: 6.1–16.9 years) were evaluated with an extensive battery of neuropsychological tests tailored to the patient's age. Furthermore, the child and his/her parent(s) completed self‐report questionnaires about emotional functioning and quality of life. In both groups, tests were administered before any therapeutic intervention such as surgery, chemotherapy, or irradiation. Groups were comparable with regard to age, gender, and socioeconomic status.

Results

Compared to the control group, patients with BTs performed significantly worse in tests of working memory, verbal memory, and attention (effect sizes between 0.28 and 0.47). In contrast, the areas of perceptual reasoning, processing speed, and verbal comprehension were preserved at the time of measurement.

Conclusion

Our results highlight the need for cognitive interventions early in the treatment process in order to minimize or prevent academic difficulties as patients return to school. Pediatr Blood Cancer 2015;62:1805–1812. © 2015 The Authors. Pediatric Blood & Cancer, published by Wiley Periodicals, Inc.  相似文献   
29.

Background

The Institute of Medicine (IOM) report, The Future of Nursing, included recommendations to increase nurse diversity, the percent of nurses obtaining a bachelor’s degree, and inter-professional education.

Purpose

The purpose of this paper is to report the progress toward achievement of these recommendations.

Methods

We used a longitudinal, multi-state data from four cohorts of nurses newly licensed in 2004 to 2005, 2007 to 2008, 2010 to 2011, and 2014 to 2015 to examine and compare the trends.

Finding

The percentage of males who became licensed increased, from 8.8% in 2004 to 2005 cohort to 13.6% in the 2014 to 2015 cohort. The percentage of white-non-Hispanic nurses who were licensed decreased from 78.9% in 2007 to 2008 to 73.8% in 2014 to 2015. These differences primarily reflect an increase in white-Hispanic nurses. More nurses are obtaining a bachelor’s degree as their first professional degree, from 36.6% in 2004 to 2005 cohort to 48.5% in 2014 to 2015 cohort. About 40% of the 2014 to 2015 cohort reported that they learned to work in inter-professional teams. Collegial nurse-physician relations had an upward positive trajectory over time increasing almost 7%.

Discussion

The diversity and education of new nurses have increased, but are short of meeting the IOM recommendations.  相似文献   
30.
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