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   2741篇
  免费   313篇
  国内免费   9篇
耳鼻咽喉   32篇
儿科学   100篇
妇产科学   58篇
基础医学   352篇
口腔科学   53篇
临床医学   285篇
内科学   513篇
皮肤病学   62篇
神经病学   267篇
特种医学   76篇
外科学   434篇
综合类   67篇
一般理论   2篇
预防医学   301篇
眼科学   46篇
药学   281篇
中国医学   1篇
肿瘤学   133篇
  2021年   39篇
  2020年   25篇
  2019年   45篇
  2018年   55篇
  2017年   35篇
  2016年   40篇
  2015年   50篇
  2014年   53篇
  2013年   84篇
  2012年   112篇
  2011年   132篇
  2010年   80篇
  2009年   57篇
  2008年   121篇
  2007年   127篇
  2006年   118篇
  2005年   119篇
  2004年   104篇
  2003年   100篇
  2002年   121篇
  2001年   116篇
  2000年   106篇
  1999年   66篇
  1998年   36篇
  1997年   40篇
  1996年   34篇
  1995年   34篇
  1994年   24篇
  1993年   26篇
  1992年   60篇
  1991年   68篇
  1990年   59篇
  1989年   65篇
  1988年   58篇
  1987年   57篇
  1986年   54篇
  1985年   48篇
  1984年   49篇
  1983年   33篇
  1982年   18篇
  1981年   23篇
  1979年   27篇
  1978年   23篇
  1977年   34篇
  1976年   25篇
  1975年   28篇
  1974年   31篇
  1973年   28篇
  1972年   16篇
  1968年   18篇
排序方式: 共有3063条查询结果,搜索用时 0 毫秒
31.
OBJECTIVE: Patients affected by schizophrenia show deficits in both visual perception and working memory. The authors tested early-stage vision and working memory in subjects with schizotypal personality disorder, which has been biologically associated with schizophrenia. METHOD: Eleven subjects who met DSM-III-R criteria for schizotypal personality disorder and 12 normal comparison subjects were evaluated. Performance thresholds were obtained for tests of visual discrimination and working memory. Both form and trajectory processing were evaluated for each task. RESULTS: Subjects with schizotypal personality disorder showed intact discrimination of form and trajectory but were impaired on working memory tasks. CONCLUSIONS: These data suggest that subjects with schizotypal personality disorder, unlike patients affected by schizophrenia, have relatively intact visual perception. Subjects with schizotypal personality disorder do show specific deficits on tasks of comparable difficulty when working memory demands are imposed. Schizotypal personality disorder may be associated with a more specific visual processing deficit than schizophrenia, possibly reflecting disruption of frontal lobe systems subserving visual working memory operations.  相似文献   
32.
This study was designed to compare the growth of Pakistani schoolchildren in the UK with the 1990 UK growth standards. Measurements of height, weight, and sitting height were performed on 785 Pakistani schoolchildren aged 5-14 years with the mean values for each age and sex being plotted on the UK growth standards. The results were expressed as SD scores relative to the 1990 reference data. The mean height for the boys was only 0.2 SD scores below the mean for the new growth standards with the mean height for the girls being 0.4 SD scores below the mean. The mean values for weight and body mass index were 0.3 and 0.5 SD scores less than the mean for boys and girls respectively. This study demonstrates that the growth of Pakistani schoolchildren in the UK is comparable to the 1990 UK growth standards with only minor differences. It is not safe to assume that short stature or low body weight in a Pakistani child is due to his or her ethnic background.  相似文献   
33.
Low-grade astrocytomas in children: evolving management strategies   总被引:2,自引:0,他引:2  
Developments in imaging and in neurosurgical techniques over the past decade have substantially altered the management of children with low-grade astrocytoma. Indications for surgery have become more clearly defined, and a larger proportion of children undergo complete or subtotal resection than in the past. Fewer receive adjuvant therapy, even though the options in this regard are more numerous now and theoretically likely to result in less morbidity than conventional external beam radiotherapy.

This review will address in particular the correlations between location, imaging appearance, and behavior that need to be more widely appreciated, and present recommendations regarding the management of these tumors.  相似文献   

34.
Objectives: To explore staff views on their roles, skills and training to deliver high quality and local intrapartum services in remote and rural settings against national recommendations.  相似文献   
35.
Advances in pediatric liver and intestinal transplantation   总被引:7,自引:0,他引:7  
BACKGROUND: Significant progress has been made with liver and intestinal transplantation in pediatric patients. Shortage of whole-organ cadaveric grafts has resulted in a high mortality rate for children awaiting transplantation. New surgical procedures such as split-liver transplantation and living-related liver transplantation have evolved over the last decade to maximize donor utilization in pediatric patients. METHODS: In this article we review the current indications and contraindications for liver and intestinal transplantation in children, the surgical innovations to expand an exceedingly small cadaveric liver pool, postoperative management, and the impact on patient and graft survival. RESULTS: Reduced-size liver transplantation provides children with much needed small grafts; however, split-liver transplantation may eliminate the need for reduced-size and living-related liver transplantation except in urgent situations. CONCLUSION: Liver transplantation is a durable procedure that provides excellent long-term survival. The use of living-related and split-liver transplantation has dramatically reduced the waiting periods for children and improved survival. In the past decade significant progress has been made with intestinal transplantation owing to improvements in surgical technique, immunosuppressive agents, and early identification and treatment of postoperative complications.  相似文献   
36.
37.
Malondialdehyde (MDA) is a product of lipid peroxidation and prostaglandin biosynthesis. It is mutagenic and carcinogenic and the major adduct formed by reaction with DNA, a highly fluorescent pyrimidopurinone (M1-dG), has been detected in healthy human liver and leukocyte DNA. Analytical methods used so far for the detection of M1- dG have not been applied to a large number of individuals or variety of samples. Often, only a few microg of DNA from human tissues are available for analysis and a very sensitive assay is needed in order to detect background levels of M1-dG in very small amounts of DNA. In this paper, the development of an immunoslot blot (ISB) assay for the measurement of MI-dG in 1 microg of DNA is described. The limit of detection of the assay is 2.5 adducts per 10(8) bases. A series of human samples were analysed and levels of 5.6-9.5 (n = 8) and 3.1-64.3 (n = 42) of M1-dG per 10(8) normal bases were detected in white blood cell and gastric biopsy DNA, respectively. Results on four human samples were compared with those obtained using an HPLC/32P-post- labelling (HPLC/PPL) method previously developed and indicated a high correlation between M1-dG levels measured by the two assays. The advantages of ISB over other assays including HPLC/PPL, such as the possibility of analysing 1 microg DNA/sample and the fact that it is less time-consuming and laborious, means that it can be more easily used for routine analysis of a large number of samples in biomonitoring studies.   相似文献   
38.
OBJECTIVE: To describe the attitudes that women with chronic pelvic pain (CPP) attending gynaecology clinics have to their consultations and to determine the ways in which their health care can be improved. DESIGN: Qualitative study using semistructured individual interviews. SETTING: UK gynaecology outpatient clinics in district general and teaching hospitals. SAMPLE: Twenty-six women with CPP. METHODS: Semistructured individual interviews were conducted. Data gathering and analysis followed a grounded theory approach. MAIN OUTCOME MEASURES: Women's wishes regarding their care and their actual experiences of care. RESULTS: Four main themes emerged. The women wanted (a) personal care, which they often did not receive; (b) to feel understood and to be taken seriously, although they often felt dismissed, which applied both to women with and without an explanation for their pain; (c) explanation as much as cure, but an adequate explanation was often not provided; and (d) to be reassured, which often they were not. Effective reassurance was complex as it included general reassurance and specific reassurance about cause and treatment. CONCLUSIONS: Improvements are needed in the outpatient care of women presenting with CPP. Changes should focus on providing more personal care, so that presenting problems are seen to be taken seriously, findings and management are appropriately explained, and women are more effectively reassured. Interventions need to be developed that meet these needs and tested to determine if they are feasible, acceptable, and improve outcomes.  相似文献   
39.
40.
Aims The aim was to estimate the incidence of severe hypoglycaemia requiring emergency ambulance assistance, its management and associated costs. Methods A retrospective observational study used routinely collected data for a 1‐year period from December 2009 to November 2010 from the South Central Ambulance Service National Health Service Trust, UK. The main outcome was episodes reported by ambulance personnel and costs were estimated from published data. Results During the 1‐year study period, 398 409 emergency calls were received, of which 4081 (1.02%) were coded as hypoglycaemia. The overall numbers (and annual rate) of hypoglycaemia recorded among people ≥ 15 years with presumed diabetes was 3962 (2.1%), but for those aged 15–35 years was 516 (7.5%) and for those aged ≥ 65 years was 1886 (1.9%). Of those attended, 1441 (35.3%) were taken to hospital. The estimated total cost of initial ambulance attendance and treatment at scene was £553 000; if transport to hospital was necessary, the additional ambulance costs were £223 000 plus emergency department costs of £140 000; and the cost of primary care follow‐up was estimated as £61 000. The average cost per emergency call was £263. The estimated annual cost of emergency calls for severe hypoglycaemia is £13.6m for England. Conclusions Our estimates suggest prevalence of severe hypoglycaemia attended by the emergency services is high in younger age groups and lower for older age groups, although the absolute numbers of severe events in older age groups contribute substantially to the overall costs of providing emergency assistance for hypoglycaemia.  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