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   3061篇
  免费   371篇
  国内免费   5篇
耳鼻咽喉   26篇
儿科学   122篇
妇产科学   60篇
基础医学   411篇
口腔科学   98篇
临床医学   422篇
内科学   543篇
皮肤病学   48篇
神经病学   279篇
特种医学   127篇
外科学   316篇
综合类   141篇
一般理论   1篇
预防医学   342篇
眼科学   75篇
药学   235篇
中国医学   2篇
肿瘤学   189篇
  2022年   36篇
  2021年   103篇
  2020年   53篇
  2019年   76篇
  2018年   89篇
  2017年   57篇
  2016年   53篇
  2015年   50篇
  2014年   72篇
  2013年   109篇
  2012年   157篇
  2011年   117篇
  2010年   76篇
  2009年   66篇
  2008年   130篇
  2007年   141篇
  2006年   109篇
  2005年   126篇
  2004年   109篇
  2003年   107篇
  2002年   103篇
  2001年   92篇
  2000年   95篇
  1999年   91篇
  1998年   33篇
  1997年   26篇
  1996年   40篇
  1995年   35篇
  1994年   30篇
  1993年   32篇
  1992年   57篇
  1991年   62篇
  1990年   66篇
  1989年   56篇
  1988年   59篇
  1987年   42篇
  1986年   50篇
  1985年   37篇
  1984年   44篇
  1983年   31篇
  1980年   25篇
  1979年   36篇
  1978年   27篇
  1972年   24篇
  1971年   37篇
  1970年   29篇
  1969年   31篇
  1968年   22篇
  1967年   28篇
  1966年   31篇
排序方式: 共有3437条查询结果,搜索用时 15 毫秒
61.
Because of the limited number of case reports on the use of electroconvulsive therapy (ECT) in adolescent psychiatric patients, we retrospectively reviewed the medical records of 20 young patients who underwent ECT. They constituted all the patients 相似文献   
62.
We have seen two cases of traumatic subcapital fractures of the femoral neck which resembled pathologic fractures on plain radiography. We have named this entity pseudopathologic fracture of the femoral neck and offer suggestions for why it occurs.  相似文献   
63.
OBJECTIVE: Under the Pharmaceutical Benefits Scheme, the use of H2-receptor antagonists (H2A) in the treatment of dyspepsia and heartburn is only subsidised when there is a proven diagnosis of ulcer. This study compared the costs of this Australian practice with a simulation of British practice, which allows unrestricted prescribing of subsidised H2A. DESIGN: Patients with heartburn and/or dyspepsia were prospectively randomised to either a "British" group treated freely at the discretion of their general practitioner without necessarily being investigated or an "Australian" group where use of H2A was allowed only after gastroscopy or a barium meal had demonstrated a peptic ulcer or ulcerative oesophagitis. The patients were followed up for six months and all direct and indirect costs were recorded. SETTING: Forty-nine Sydney general practitioners recruited primary care patients for the study. PATIENTS: Any patient with heartburn or dyspepsia was considered for recruitment; 139 patients entered the study and 137 completed it. MAIN OUTCOME MEASURES: The outcome measures were the costs of general practitioner consultations, specialist consultations, radiology and gastroscopy, other tests, H2A, other medications, personal costs, and total cost per patient. RESULTS: The cumulative total cost per patient at the end of the study was equivalent in the "Australian" ($392) and "British" ($406) groups. A higher initial cost per patient of H2A in the "British" group was offset by a rapid decrease in the proportion that continued to use H2A and by the cost of specialist consultations and investigations in the "Australian" group. CONCLUSION: Over a six-month period the cost of early investigation of heartburn and dyspepsia was equivalent to the cost of a therapeutic trial of H2A.  相似文献   
64.
65.
OBJECTIVE: The authors' goal was to replicate a previous finding that smokers have lower brain monoamine oxidase B (MAO-B) levels than comparison nonsmoking subjects and to determine if levels recover after overnight cigarette abstinence. METHOD: Brain MAO-B levels were measured by means of positron emission tomography in six smokers who were scanned twice: 11.3 hours (baseline) and 10 minutes after smoking one cigarette. RESULTS: Average MAO-B levels in smokers in the present study were similar to those found in the previous study and averaged 39% (SD=17) lower than those found in a comparison group of nonsmokers. Brain MAO-B levels did not differ between baseline levels and 10 minutes after smoking. CONCLUSIONS: This study reinforces the need to investigate whether MAO-B inhibition may account for some of the behavioral and epidemiological features of smoking.  相似文献   
66.
The concentration of ethanol in blood, breath or urine constitutes important evidence for prosecuting drunk drivers. For various reasons, the reliability of the results of forensic alcohol analysis are often challenged by the defence. One such argument for acquittal concerns the notion that alcohol could be produced naturally in the body, hence the term 'auto-brewery' syndrome. Although yeasts such as Candida albicans readily produce ethanol in-vitro, whether this happens to any measurable extent in healthy ambulatory subjects is an open question. Over the years, many determinations of endogenous ethanol have been made, and in a few rare instances (Japanese subjects with very serious yeast infections) an abnormally high ethanol concentration (> 80 mg/dl) has been reported. In these atypical individuals, endogenous ethanol appeared to have been produced after they had eaten carbohydrate-rich foods. A particular genetic polymorphism resulting in reduced activity of enzymes involved in hepatic metabolism of ethanol and a negligible first-pass metabolism might explain ethnic differences in rates of endogenous ethanol production and clearance. Other reports of finding abnormally high concentrations of ethanol in body fluids from ostensibly healthy subjects suffer from deficiencies in study design and lack suitable control experiments or used non-specific analytical methods. With reliable gas chromatographic methods of analysis, the concentrations of endogenous ethanol in peripheral venous blood of healthy individuals, as well as those suffering from various metabolic disorders (diabetes, hepatitis, cirrhosis) ranged from 0-0.08 mg/dl. These concentrations are far too low to have any forensic or medical significance. The notion that a motorist's state of intoxication was caused by endogenously produced ethanol lacks merit.  相似文献   
67.
Dermofasciectomy in the management of Dupuytren's disease   总被引:5,自引:0,他引:5  
Dupuytren's disease may present with well-defined subcutaneous cords or as more diffuse disease with involvement of the skin. Fasciectomy is the procedure commonly carried out for the full range of disease, but is associated with rates of recurrence of up to 66%. We reviewed 143 rays in 103 patients undergoing dermofasciectomy for diffuse disease with involvement of the skin. We found recurrence in 12 rays (8.4% of rays; 11.6% of patients) during a mean follow-up of 5.8 years, eight as cords and four as nodules. We suggest that dermofasciectomy is a better method of disease control than fasciectomy for the more diffuse type of disease with involvement of the skin.  相似文献   
68.
BACKGROUND: Whole organ extracorporeal perfusion of a genetically modified humanized (transgenic) pig liver has been proposed as a technology that may sustain patients with severe liver failure while awaiting human liver transplantation. METHODS: We report on two cases of successful extracorporeal perfusion of a transgenic pig liver in patients awaiting transplantation for fulminant hepatic failure. The pig livers used were transgenic for human CD55 (decay-accelerating factor) and human CD59. These transgenic modifications are designed to reduce or eliminate the hyperacute rejection inherent in pig-to-primate xenotransplants. We also report on the results of serial surveillance testing for presence of the porcine endogenous retrovirus (PoERV) in these two patients. RESULTS: Extracorporeal perfusion in two patients was performed for 6.5 and 10 hr, respectively, followed by the successful transplantation of a human liver and resultant healthy patients (18 and 5 months later as of this writing). The porcine livers showed evidence of synthetic and secretory function (decreasing protime and bilirubin, bile production). Serial polymerase chain reaction analysis of these patients' peripheral blood mononuclear cells has failed to show presence of PoERV DNA sequences. CONCLUSIONS: The CD55/CD59 transgenic porcine liver appears capable of safely "bridging" a patient to liver transplantation. Human PoERV infection from these livers has yet to be demonstrated.  相似文献   
69.
70.
The optometric profession in the UK has a major role in the detection, assessment and management of ocular anomalies in children between 5 and 16 years of age. The role complements a variety of associated screening services provided across several health care sectors. The review examines the evidence-base for the content, provision and efficacy of these screening services in terms of the prevalence of anomalies such as refractive error, amblyopia, binocular vision and colour vision and considers the consequences of their curtailment. Vision screening must focus on pre-school children if the aim of the screening is to detect and treat conditions that may lead to amblyopia, whereas if the aim is to detect and correct significant refractive errors (not likely to lead to amblyopia) then it would be expedient for the optometric profession to act as the major provider of refractive (and colour vision) screening at 5-6 years of age. Myopia is the refractive error most likely to develop during primary school presenting typically between 8 and 12 years of age, thus screening at entry to secondary school is warranted. Given the inevitable restriction on resources for health care, establishing screening at 5 and 11 years of age, with exclusion of any subsequent screening, is the preferred option.  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