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   3773篇
  免费   182篇
  国内免费   19篇
耳鼻咽喉   18篇
儿科学   310篇
妇产科学   30篇
基础医学   274篇
口腔科学   99篇
临床医学   282篇
内科学   768篇
皮肤病学   39篇
神经病学   220篇
特种医学   107篇
外科学   895篇
综合类   86篇
一般理论   2篇
预防医学   161篇
眼科学   131篇
药学   252篇
中国医学   9篇
肿瘤学   291篇
  2024年   3篇
  2023年   40篇
  2022年   91篇
  2021年   202篇
  2020年   91篇
  2019年   131篇
  2018年   171篇
  2017年   121篇
  2016年   141篇
  2015年   140篇
  2014年   213篇
  2013年   241篇
  2012年   357篇
  2011年   376篇
  2010年   196篇
  2009年   170篇
  2008年   226篇
  2007年   220篇
  2006年   186篇
  2005年   145篇
  2004年   146篇
  2003年   104篇
  2002年   82篇
  2001年   27篇
  2000年   24篇
  1999年   30篇
  1998年   19篇
  1997年   5篇
  1996年   11篇
  1995年   5篇
  1994年   4篇
  1993年   2篇
  1992年   8篇
  1991年   5篇
  1990年   6篇
  1989年   4篇
  1986年   3篇
  1985年   1篇
  1984年   1篇
  1982年   1篇
  1978年   2篇
  1977年   1篇
  1974年   3篇
  1973年   1篇
  1972年   1篇
  1971年   3篇
  1970年   1篇
  1969年   2篇
  1968年   5篇
  1967年   4篇
排序方式: 共有3974条查询结果,搜索用时 8 毫秒
201.

Objective  

To compare efficacy and tolerability of levosalbutamol (Group 1) and racemic salbutamol (Group 2) for the treatment of acute exacerbation of asthma in children age 5 to 18 yr.  相似文献   
202.
203.
204.
OBJECTIVE: Computerised monitors can detect and, with clinical intervention, often prevent or ameliorate adverse drug events (ADEs). We evaluated whether a computer-based alerting system was useful in a community hospital setting. METHODS: We evaluated 6 months of retrospectively collected medication and laboratory data from a 140-bed community hospital, and applied the rules from a computerised knowledge base to determine if the resulting alerts might have allowed a clinician to prevent or lessen harm related to medication toxicity. We randomly selected 11% (n = 58, of which 56 were available) of charts deemed to be high- or critical-priority alerts, based on the likelihood of the alerts being associated with injury, to determine the frequencies of ADEs and preventable ADEs. RESULTS: In 6 months, there were 8829 activations of the rule set, generating a total of 3547 alerts. Of these, 528 were of high or critical priority, 664 were of medium priority and 2355 were of low priority. Chart review among the sample (56 charts) of high- or critical-priority alerts found five non-preventable and two preventable ADEs, suggesting that among the total high- or critical-priority alerts alone, there would be approximately 94 non-preventable ADEs and 37 preventable ADEs annually in this hospital that could be detected using this method. CONCLUSIONS: Computer-based rules engines have the potential to identify and, with clinical intervention, mitigate preventable ADEs, and implementation is feasible in community hospitals without an advanced information technology application.  相似文献   
205.

Background  

To assess the impact of knowing central corneal thickness (CCT) on glaucoma management in a United Kingdom district general hospital.  相似文献   
206.
Guanine ribonucleosides substituted at the 8 position of the guanine ring are a unique class of immunomodulators, the lead compound of which is 7-allyl-8-oxoguanosine (loxoribine). We conducted a double-blind randomized phase I study to evaluate the safety, pharmacokinetics, and immunologic effects of single ascending doses of loxoribine in patients with advanced cancer. Twenty-four patients were treated in three dose tiers of 8 patients each, utilizing a unique statistical design, so that within each group, patients were randomized in blocks of 4 to receive loxoribine initially and then placebo 4 weeks later--a sequence that was reversed in the remaining 4 patients. In 23 courses of loxoribine and 20 courses of placebo, toxicity was mild and infrequent at all dose tiers (1 mg/kg, 5 mg/kg and 10 mg/kg. Both antibody-dependent cellular cytotoxicity and lymphokine-activated killer cytotoxicity were transiently depressed following loxoribine administration at all doses. Loxoribine is safe at doses up to 10 mg/kg in patients with advanced cancer, and produces modest immunologic effects. Further testing, particularly in conjunction with other immunologic agents, is warranted.  相似文献   
207.
The study covers 78 children with typhoid fever who were hospitalized in April & May 1990. Serious complications were present in 32% (toxemia 22%, ileus 25% and myocarditis 8%). Blood cultures were positive in 30 of 49 tested. Others were diagnosed by positive Widal test.In vitro cultures ofS. typhi were resistant to chloramphenicol (90%), ampicillin (93%) and co-trimoxazole (97%). However all were highly sensitive to ciprofloxacin and moderately sensitive to cephalexin and gentamycin. Ciprofloxacin alone or in combination was given in 73 of the 78 children and found to be remarkably effective in controlling the disease and preventing relapse. No serious side effects were noted. The cohort is being followed up for possible long term adverse effects.  相似文献   
208.
A 15-year-old boy presented with chest pain and a new heart murmur. The clinical diagnosis of pulmonary stenosis was confirmed by two-dimensional and Doppler echocardiographic examinations. A large, encapsulated, partly solid and partly cystic tumor in the anterior mediastinum, visualized by ultrasonography, was compressing the main pulmonary artery and producing the right ventricular outflow tract obstruction. The tumor was removed surgically and was found to be a benign teratoma. Postoperative ultrasound examination of the right ventricular outflow tract showed no evidence of obstruction. We conclude that: (1) there are subtle clinical diagnostic differences between intrinsic and extrinsic pulmonary stenosis; (2) ultrasound examination can make cardiac catheterization unnecessary; and (3) relief of the extrinsic cause of pulmonary stenosis should be curative.  相似文献   
209.
Herpes simplex virus-mediated gene delivery to the rodent visual system   总被引:3,自引:0,他引:3  
PURPOSE: To determine the types of cells in the visual system of the mouse and rat that can express a transgene delivered by an attenuated replication competent Herpes simplex virus-1 (HSV-1) vector. METHODS: C57/BL6 x BALB/C mice and Albino rats were treated with 1 x 10(7) pfu of the HSV-1 ribonucleotide reductase mutant (hrR3) expressing the Escherichia coli lacZ gene. The hrR3 virus was delivered by topical application to the cornea, intravitreal (IV) injection, intracameral injection (IC), or stereotactic injection into the visual cortex (VC). At specified times postinfection, animals were killed and tissues were removed, fixed, sectioned, and stained with X-gal or hematoxylin and eosin for histochemical and histopathologic examination. RESULTS: Topical delivery after corneal scarification in both mouse and rat resulted in lacZ expression in 25% of the corneal epithelial cells and 25% of the retinal pigment epithelium (RPE) cells. Topical application without concurrent scarification also resulted in transgene delivery to 20% of the RPE cells of the rat but not the mouse. IV injection resulted in expression primarily in RPE cells, with up to 100% of the cells expressing lacZ in the mouse and rat. Other cells expressing the transgene included ciliary body (CB) and optic nerve cells. Up to 25% of the retinal ganglion cells in the rat expressed lacZ, but only rarely in mice. IC delivery in rats resulted in expression in trabecular meshwork, CB cells, RPE, and iris epithelium. Injection into area 17 of the rat VC resulted in efficient labeling of the VC neurons and neurons in the lateral geniculate nucleus without any evident pathology or inflammation. Neither inflammation nor disease pathology was observed in either the mouse or rat after any route of delivery. CONCLUSIONS: It was demonstrated that the hrR3 HSV-1 virus can deliver a functioning gene to several cell types in the eye and neurons in the VC and that the virus can move via retrograde transport to nuclei that project to the VC.  相似文献   
210.
The cardiometabolic syndrome, an interesting constellation of maladaptive cardiovascular, renal, metabolic, prothrombotic, and inflammatory abnormalities, is now recognized as a disease entity by the American Society of Endocrinology, National Cholesterol Education Program, and World Health Organization, among others. These cardiovascular and metabolic derangements individually and interdependently lead to a substantial increase in cardiovascular disease (CVD) morbidity and mortality, making the cardiometabolic syndrome an established and strong risk factor for premature and severe CVD and stroke. Established and evolving treatment strategies including moderate physical activity, weight reduction, rigorous blood pressure control, correction of dyslipidemia, and glycemic control have proven beneficial in reversing these abnormal responses and decreasing the CVD risk.  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