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   675篇
  免费   73篇
  国内免费   9篇
耳鼻咽喉   3篇
儿科学   30篇
妇产科学   11篇
基础医学   81篇
口腔科学   17篇
临床医学   87篇
内科学   110篇
皮肤病学   8篇
神经病学   144篇
特种医学   55篇
外科学   100篇
综合类   20篇
预防医学   27篇
眼科学   3篇
药学   35篇
肿瘤学   26篇
  2023年   3篇
  2022年   4篇
  2021年   5篇
  2020年   7篇
  2019年   11篇
  2018年   16篇
  2017年   8篇
  2016年   11篇
  2015年   16篇
  2014年   12篇
  2013年   24篇
  2012年   37篇
  2011年   31篇
  2010年   29篇
  2009年   25篇
  2008年   23篇
  2007年   47篇
  2006年   45篇
  2005年   28篇
  2004年   22篇
  2003年   18篇
  2002年   25篇
  2001年   24篇
  2000年   18篇
  1999年   14篇
  1998年   18篇
  1997年   23篇
  1996年   19篇
  1995年   11篇
  1994年   18篇
  1993年   15篇
  1992年   19篇
  1991年   12篇
  1990年   12篇
  1989年   8篇
  1988年   12篇
  1987年   16篇
  1986年   15篇
  1985年   13篇
  1984年   8篇
  1982年   4篇
  1981年   7篇
  1980年   2篇
  1978年   5篇
  1977年   2篇
  1976年   2篇
  1974年   2篇
  1973年   2篇
  1972年   2篇
  1970年   2篇
排序方式: 共有757条查询结果,搜索用时 15 毫秒
1.
ResearchGate is a world wide web for scientists and researchers to share papers, ask and answer questions, and find collaborators. As one of the more than 15 million members, the author uploads research output and reads and responds to some of the questions raised, which are related to type 2 diabetes. In that way, he noticed a serious gap of knowledge of this disease among medical professionals over recent decades. The main aim of the current study is to remedy this situation through providing a comprehensive review on recent developments in biochemistry and molecular biology, which can be helpful for the scientific understanding of the molecular nature of type 2 diabetes. To fill up the shortcomings in the curricula of medical education, and to familiarize the medical community with a new concept of the onset of type 2 diabetes, items are discussed like: Insulin resistance, glucose effectiveness, insulin sensitivity, cell membranes, membrane flexibility, unsaturation index (UI; number of carbon-carbon double bonds per 100 acyl chains of membrane phospholipids), slow-down principle, effects of temperature acclimation on phospholipid membrane composition, free fatty acids, energy transport, onset of type 2 diabetes, metformin, and exercise. Based on the reviewed data, a new model is presented with proposed steps in the development of type 2 diabetes, a disease arising as a result of a hypothetical hereditary anomaly, which causes hyperthermia in and around the mitochondria. Hyperthermia is counterbalanced by the slow-down principle, which lowers the amount of carbon-carbon double bonds of membrane phospholipid acyl chains. The accompanying reduction in the UI lowers membrane flexibility, promotes a redistribution of the lateral pressure in cell membranes, and thereby reduces the glucose transporter protein pore diameter of the transmembrane glucose transport channel of all Class I GLUT proteins. These events will set up a reduction in transmembrane glucose transport. So, a new blood glucose regulation system, effective in type 2 diabetes and its prediabetic phase, is based on variations in the acyl composition of phospholipids and operates independent of changes in insulin and glucose concentration. UI assessment is currently arising as a promising analytical technology for a membrane flexibility analysis. An increase in mitochondrial heat production plays a pivotal role in the existence of this regulation system.  相似文献   
2.
3.
OBJECTIVE: Colonic infarction is a recognized complication of abdominal aortic aneurysm (AAA) surgery. The clinical difficulty in establishing the diagnosis combined with the patient's poor physiological status is usually associated with a fatal outcome. We assessed our experience with this problem to identify a possible risk factor profile for these patients. METHOD: Patients records were identified from the operative logs, intensive care unit, Hospital Inpatient Enquiry system and vascular unit databases over a 6-year period. RESULTS: A total of 405 patients underwent AAA repair during this period; 140 as emergency ruptures. Nine patients were identified from the databases with known colonic infarction (2.2%). One was a woman. The mean age was 70 years. Seven patients had emergency ruptures (5%). Twenty independent risk factors were analysed using univariate and multivariate logistic regression models. Significant risk factors identified by using a multivariate analysis included the nature of the presenting patient, preoperative hypotension, prolonged cross-clamp time, intra-operative ischaemia and postoperative acidosis. Confirmatory diagnosis was made by colonoscopy in eight patients. One patient survived following the salvage surgery. The mean duration of survival was 10.5 days. The overall mortality was 89% of patients. CONCLUSION: In our unit infrarenal AAA repair has a 2.2% rate of colonic infarction. A definitive diagnosis is best made by colonoscopy. A risk factor profile for the development of colonic infarction may be constructed on the basis of specific clinical parameters. Earlier intervention on the basis of this profile may ultimately reduce the current excessive mortality.  相似文献   
4.
5.
As most of those experiencing traumatic brain injury tend to be young, disabled survivors will be gradually accruing in each locality as each year passes. How many need continuing care a decade after injury? How many need day care, or need help with finding work, or continuing support for carers? 190 patients who had been admitted to two UK regional neurosurgical units on average some 7 years earlier were followed up. With an average age of 29 years these patients stayed in hospital for an average 33 days. At follow-up 23% were classified as having moderate disability or worse on the Glasgow Outcome Scale, including 7.4% who had died subsequent to discharge. Survivors were given a neuropsychological assessment and a socioeconomic interview. Of the survivors, 17% had failed to make a good recovery, but 36% were failing to occupy their time in a meaningful way. Age over 30 at time of injury, not occupied before injury, and above-average length of stay were some of the predictors for failing to occupy time. Quality of life was severely curtailed for those who could not occupy their time, as was the case for their carers. Appropriate counselling, vocational evaluation and family support in the early years following injury may help to improve quality of life for both the head-injured person and their carers.  相似文献   
6.
7.
8.
BACKGROUND: Paediatric audiology services and screening programmes are currently under review. AIMS AND METHODS: To investigate current practice and performance of the school hearing screening programme (SHSP) by means of a questionnaire. RESULTS: SHSP was found to detect previously unrecognised hearing loss at low cost. Wide variation in practice was shown, and the majority of services had no computerised system for data collection. CONCLUSION: There is a need for nationally agreed protocols and quality assurance procedures.  相似文献   
9.
To investigate whether the secular trend for growth in Dutch children still exists, the Oosterwolde I study of 1980 was repeated in 1989. A persisting secular trend was visible for height while the z scores of body proportions show no change during the past 10 years, which suggests that there is no change in the timing of puberty.  相似文献   
10.
Summary The influence of tapering on the metabolic and performance parameters in endurance cyclists was investigated. Cyclists (n = 25) trained 5 days · week–1, 60 min·day–1, at 75–85% maximal oxygen consumption (VO2max) for 8 weeks and were then randomly assigned to a taper group: 4D (4 days;n = 7), 8D (8 days;n = 6), CON (control, 4 days rest;n = 6), NOTAPER (non-taper, continued training;n = 6). Muscle biopsy specimens taken before and after training and tapering were analysed for carnitine palmityltransferase (CPT), citrate synthase, ß-hydroxyacyl CoA dehydrogenase (HOAD), cytochrome oxidase (CYTOX), lactate dehydrogenase, glycogen and protein. Significant increases inVO2max (6%), a 60-min endurance cycle test (34.5%), oxidative enzymes (77–178%), glycogen (35%) and protein (34%) occurred following training. After the taper, HOAD and CPT decreased 25 % (P<0.05) and 26% respectively, in the CON. Post-taper CYTOX values were different (P<0.05) for 4D and 8D compared with CON. Muscle glycogen levels were increased (P<0.05) after tapering in the 4D, 8D and CON, but decreased in NOTAPER. Similarly, power output at ventilation threshold was significantly increased in the 4D (27.4 W) and 8D (27 W) groups, but decreased (22 W) in the NOTAPER. These findings suggest that tapering elicited a physiological adaptation by altering oxidative enzymes and muscle glycogen levels. Such an adaptation may influence endurance cycling during a laboratory performance test.  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