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   1813篇
  免费   108篇
  国内免费   2篇
耳鼻咽喉   19篇
儿科学   131篇
妇产科学   27篇
基础医学   174篇
口腔科学   71篇
临床医学   115篇
内科学   343篇
皮肤病学   12篇
神经病学   78篇
特种医学   66篇
外科学   184篇
综合类   47篇
一般理论   1篇
预防医学   112篇
眼科学   102篇
药学   260篇
中国医学   18篇
肿瘤学   163篇
  2023年   24篇
  2022年   44篇
  2021年   85篇
  2020年   51篇
  2019年   50篇
  2018年   62篇
  2017年   47篇
  2016年   41篇
  2015年   37篇
  2014年   73篇
  2013年   89篇
  2012年   120篇
  2011年   141篇
  2010年   75篇
  2009年   52篇
  2008年   72篇
  2007年   75篇
  2006年   74篇
  2005年   67篇
  2004年   83篇
  2003年   85篇
  2002年   65篇
  2001年   56篇
  2000年   42篇
  1999年   20篇
  1998年   13篇
  1997年   8篇
  1996年   12篇
  1995年   7篇
  1993年   5篇
  1992年   7篇
  1991年   14篇
  1990年   11篇
  1989年   15篇
  1988年   16篇
  1987年   25篇
  1986年   21篇
  1985年   16篇
  1984年   11篇
  1979年   6篇
  1977年   8篇
  1976年   8篇
  1975年   10篇
  1974年   13篇
  1973年   8篇
  1972年   10篇
  1971年   5篇
  1970年   5篇
  1969年   5篇
  1968年   8篇
排序方式: 共有1923条查询结果,搜索用时 187 毫秒
1.
2.
3.
Various 2-(4-biphenoxymethyl)-5-arylamino-1,3,4-oxadiazoles were synthesized by cyclization of the corresponding 1-(4-biphenoxyacetyl)-4-substituted thiosemicarbazides. These compounds were characterized by their elemental analyses and infrared, mass, and nuclear magnetic resonance spectral data. All substituted thiosemicarbazides (100 mg/kg, ip) and cyclized substituted oxadiazoles (100 mg/kg, ip) possessed anti-inflammatory activity, as reflected by their ability to provide protection against carrageenin-induced edema in the rat paw which ranged from 28 to 68% and 36 to 76%, respectively. Cyclization of the substituted thiosemicarbazides, in general, resulted in an increase in the anti-inflammatory activity of their corresponding substituted oxadiazoles, with the exception of those containing 2,4-dimethyl and 3,4-dimethyl substituents in their molecular structure. Hydrocortisone (10 mg/kg, ip) and oxyphenbutazone (40 mg/kg, ip) were used as the standard reference drugs and these provided 45 and 53% protection, respectively. All compounds (1 mM) possessed antiproteolytic activity and the in vitro inhibition of trypsin-induced hydrolysis of bovine serum albumin ranged from 13 to 75% for substituted thiosemicarbazides and 39 to 70% for substituted oxadiazoles. There was no relationship between the anti-inflammatory activity of substituted thiosemicarbazides and substituted oxadiazoles and their antiproteolytic effectiveness. The low toxicity of these compounds was reflected by their high approximate LD50 values, ranging from 500 to 1000 mg/kg.  相似文献   
4.
Morning glory syndrome, an unusual developmental anomaly of the optic nerve head, presenting with funnelled enlargement of the disc with a white dot in the centre and a peripheral vascular pattern along the disc margin, with features of typical entry and exit of retinal vessels on the optic nerve head and exceptionally good vision in the involved eye with old traumatic retinal detachment in the other, in a young Indian girl is described here for its rarity and indifferent clinical presentation. Various factors in its pathogenesis are postulated.  相似文献   
5.
6.
Monoamine oxidase inhibitory and anticonvulsant properties of 2-substituted styryl-6-bromo-3-(4-ethylbenzoate/4 benzhydrazide)-4-quinazoles are studied. All styryl quinazolone esters except compound number 9 exhibited monoamine oxidase inhibitory properties during oxidative deamination of kynuramine. Corresponding hydrazides were found to have relatively higher activity. All these quinazolones were able to protect against pentylenetetrazol induced seizures. These observations in general do not prove that monoamine oxidase inhibitory properties represent the biochemical basis for the anticonvulsant activity of these compounds.  相似文献   
7.
BACKGROUND: The diagnosis of hepatitis B virus (HBV) has until recently been based on traditional serologic methods targeting viral antigens and antibodies to viral proteins. The development of molecular methods allowing for the quantitation of HBV DNA is proving clinically valuable for monitoring therapy and detecting early treatment failures. OBJECTIVES: Here we report a new real-time (LightCycler) quantitative PCR for the detection of HBV DNA based on sequence specific hybridisation probes (designed in-house), targeting the HBV surface antigen. STUDY DESIGN: The assay was evaluated using a 10-fold dilution series of standard HBV DNA [Eurohep standard reference 1, genotype A, HBsAg subtype adw with a unitage of 10(6) WHO. i.u./ml] and 89 clinical serum samples. The performance was measured against a quantified standard HBV DNA working reagent (NIBSC code 98/780) and the sensitivity compared with our conventional thermal-block PCR. RESULTS AND CONCLUSION: Real-time PCR detected HBV DNA in 45% (40/89) and thermal-block PCR in 16% (14/75) of clinical samples. Results for 26 samples were below the detection limit of the thermal-block PCR but could be quantified by real-time (LightCycler) PCR. The LightCycler assay was at least 5 logs more sensitive than thermal-block PCR and could detect HBV in a linear range between 5 and 10(7) i.u. per reaction. The broad generic nature of the PCR primers coupled with the enhanced sensitivity and specificity of the fluorescent hybridisation probes makes this assay potentially valuable for both routine diagnostic and epidemiological work.  相似文献   
8.
BACKGROUND: Tight glycaemic control in people with type 2 diabetes can lead to a reduction in microvascular and possibly macrovascular complications. The use of near-patient (rapid) testing offers a potential method to improve glycaemic control. AIM: To assess the effect and costs of rapid testing for glycated haemoglobin (HbA1c) in people with type 2 diabetes. DESIGN OF STUDY: Pragmatic open randomised controlled trial. SETTING: Eight practices in Leicestershire, UK. METHOD: Patients were randomised to receive instant results for HbA1c or to routine care. The principal outcome measure was the proportion of patients with an HbA1c <7% at 12 months. We also assessed costs for the two groups. RESULTS: Of the 681 patients recruited to the study 638 (94%) were included in the analysis. The mean age at baseline was 65.7 years (SD = 10.8 years) with a median (interquartile range) duration of diabetes of 4(1-8) years. The proportion of patients with HbA1c < 7% did not differ significantly between the intervention and control groups (37 versus 38%, odds ratio 0.95 [95% confidence interval = 0.69 to 1.31]) at 12 months follow up. The total cost for diabetes-related care was 390 UK pounds per patient for the control group and 370 UK pounds for the intervention group. This difference was not statistically significant. CONCLUSION: Near-patient testing for HbA1c alone does not lead to outcome or cost benefits in managing people with type 2 diabetes in primary care. Further research is required into the use of rapid testing as part of an optimised patient management model including arrangements for patient review and testing.  相似文献   
9.
Scleredema adultorum is a rare connective tissue disorder reported usually following streptococcal infection, influenza, measles, and mumps. It has been reported occasionally following trauma and tuberculous lymphadenitis. This is a report of scleredema adultorum developing after chicken pox in an eight-year-old male child. The diagnosis was established by characteristic picture on skin biopsy using special stain. The patient had a benign course and a spontaneous recovery in two weeks. The case has been reported as the first case of scleredema adultorum developing after chicken pox.  相似文献   
10.
Enteric fever is a common infectious disease of the tropical world, about 80% of these cases occur in Asian countries. Enteric fever presenting with isolated cerebellar ataxia or nephritis is rare. We report three cases of enteric fever that presented with these complications. Isolated cerebellar ataxia usually occurs in the second week, whereas in our cases it presented within first four days of fever. The common complications of enteric fever related to the urinary tract are cystitis, pyelitis, and pyelonephritis. Glomerulonephritis is uncommon. Most patients with enteric glomerulonephritis present with acute renal failure, hypertensive encephalopathy, or nephritic syndrome. In comparison, our case had milder manifestations. All three patients were treated with parenteral ceftriaxone and showed a prompt recovery.  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