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   570篇
  免费   21篇
  国内免费   5篇
耳鼻咽喉   1篇
儿科学   22篇
妇产科学   4篇
基础医学   33篇
口腔科学   19篇
临床医学   113篇
内科学   84篇
皮肤病学   24篇
神经病学   13篇
特种医学   115篇
外科学   37篇
综合类   51篇
预防医学   27篇
眼科学   4篇
药学   28篇
  1篇
中国医学   2篇
肿瘤学   18篇
  2023年   2篇
  2022年   3篇
  2021年   6篇
  2020年   4篇
  2019年   4篇
  2018年   5篇
  2017年   5篇
  2016年   1篇
  2015年   34篇
  2014年   44篇
  2013年   26篇
  2012年   12篇
  2011年   30篇
  2010年   21篇
  2009年   23篇
  2008年   20篇
  2007年   27篇
  2006年   30篇
  2005年   18篇
  2004年   14篇
  2003年   12篇
  2002年   10篇
  2001年   9篇
  2000年   7篇
  1999年   11篇
  1998年   14篇
  1997年   14篇
  1996年   17篇
  1995年   20篇
  1994年   24篇
  1993年   11篇
  1992年   3篇
  1991年   4篇
  1990年   1篇
  1989年   9篇
  1988年   9篇
  1987年   6篇
  1986年   9篇
  1985年   21篇
  1984年   8篇
  1983年   6篇
  1982年   3篇
  1981年   10篇
  1980年   8篇
  1979年   1篇
  1978年   6篇
  1977年   10篇
  1976年   3篇
  1957年   1篇
排序方式: 共有596条查询结果,搜索用时 15 毫秒
51.

Background  

Ankylosing spondylitis is a chronic inflammatory rheumatic disorder which usually begins in early adulthood. The diagnosis is often delayed by many years. MR imaging has become the preferred imaging method for detection of early inflammation of the axial skeleton in ankylosing spondylitis.  相似文献   
52.
目的:探讨结节性硬化症(TSC)的CT表现和鉴别诊断。方法:分析7例诊断为结节性硬化症的CT资料。重点观察病变部位、大小、钙化程度及其他改变。结果:7例均有室管膜下结节,共计77个,其中钙化结节39个.80%结节位于侧脑室体部室管膜下;5例皮质及皮质下多发结节均无钙化,额枕叶为著,其次为颞顶叶:4例皮质下白质有不同程度低密度改变,主要围绕侧脑室体部及额角周围。4例合并其他畸形。结论:室管膜下多发结节并钙化,皮质异常脑回及不规则形低密度影、脑白质放射状分布的低密度改变是CT诊断结节性硬化症的主要征象,其中室管膜下结节并钙化是较有特征性的表现。CT结合临床可做出明确诊断并发现其他畸形。  相似文献   
53.
侧脑室注射血管紧张素Ⅱ促进内源性洋地黄样因子释放   总被引:1,自引:7,他引:1  
目的 探讨侧脑室注射血管紧张素Ⅱ对内源性洋地黄样因子(EDLF)释放的影响。方法 大鼠侧脑室注射血管紧张素Ⅱ及侧脑室注射Saralasin或损毁第三脑室前腹区(AV3V)预处理,放射免疫方法测定血清EDLF浓度的变化。结果 侧脑室注射AngⅡ可引起血清EDLF浓度升高;Saralasin预处理或海人酸损毁AV3V区可阻断侧脑室注射AngⅡ引起的血清EDLF升高效应。结论 侧脑室注射血管紧张素Ⅱ促进EDLF释放。  相似文献   
54.
Children with cystic fibrosis have variable degrees of exocrine pancreatic insufficiency which, if untreated, is the main cause of fat malabsorption. The impact of pancreatic enzyme supplementation on fat digestion was measured in 41 children with cystic fibrosis, 11 healthy controls, and five children with mucosal diseases by a non-invasive test of intraluminal lipolysis using 13carbon (13C) labelled mixed triglyceride (1,3-distearyl, 2[13C] octanoyl glycerol). The children with cystic fibrosis without pancreatic supplements had a median (range) 13C cumulative percentage dose recovered over six hours (cPDR) of 3.1% (0-31.7), the controls 31.0% (21.8-41.1), and the subjects with mucosal disease 27.8% (19.7-32.5). In 23 subjects with cystic fibrosis the usual dose of pancreatic enzyme supplements increased the cPDR to a median of 23.9% (0-45.6), and twice the usual dose of enteric coated microspheres increased the cPDR to 31.1% (11.1-47.8). There was no significant difference between the median cPDR of normal controls and children with mucosal disease, but there was a highly significant difference between these groups and children with untreated cystic fibrosis. Thirteen children with cystic fibrosis had no 13C recovery in their breath without enzymes and 10 showed marked increases with regular enzymes. In eight children doubling the dose of enzymes caused no or minimal improvement. The mixed triglyceride breath test offers a simple, non-invasive way of assessing the need for pancreatic enzyme supplementation in children with cystic fibrosis and could be used to optimise treatment.  相似文献   
55.
Not only does breast milk provides an ideal nutrient composition for the newborn, but it also contains a variety of substances that may actively influence growth and development of the infant and stimulate neonatal protection against gastrointestinal diseases. Hormones, growth factors, cytokines and even whole cells are present in breast milk and act to establish biochemical and immunological communication between mother and child. In addition, milk nutrients such as nucleotides, glutamine and lactoferrin have been shown to influence gastrointestinal development and host defense. The unique properties of milk as a mediator of biochemical messages will be presented and the clinical significance of breastfeeding in the prevention of neonatal gastrointestinal diseases will be discussed.  相似文献   
56.
High-field surface coil magnetic resonance (MR) images were obtained of 12 ankles: two from healthy volunteers, seven from patients, and three from fresh cadavers. The cadaver ankles were sectioned in the coronal, sagittal, and axial planes for direct comparison with the MR images. Plain film confirmation of pathologic conditions was obtained in all patients, and five underwent arthroscopy or surgery, or both. MR imaging provided excellent delineation of ligaments and cartilaginous structures in all cases.  相似文献   
57.
Management of cerebral ischemia due to Takayasu''''s arteritis   总被引:2,自引:0,他引:2  
Aortoarteritis ,alsocalledTakayasu’sarteritis ,isachronicidiopathicinflammatorydiseasethataffectslargeandmediumsizearteries Clinicalfeaturesreflectlimbororganischemiaresultingfromstenosistoobliterationofinvolvedarteries Thisdisease ,describedbyTakayasuin…  相似文献   
58.
59.
OBJECTIVES: To demonstrate initial results using Khan Kinetic Treatment (KKT) as a chronic neck pain treatment and to present pain control mechanistic theory on which the treatment is based. METHODS: A self-reported functional assessment, neck pain questionnaire, and pain medication dose were used as outcome measures for 44 matched patients randomly split into 2 groups ("treatment" and "control"). The treatment group underwent a treatment period consisting of several individual KKT treatments, whereas the control group continued conventional therapy. RESULTS: Compared with a control group, the treatment group lowered both their self-recorded neck pain scores (P=0.012) and pain medication dose (P=0.048), although current functional assessment questionnaires (range of motion, overall activity, and recreation/work activities) did not detect changes (P=0.233, 0.311, and 0.472, respectively). DISCUSSION: We address the theory of the pain control mechanisms of the device in detail. Although we await randomized placebo controlled trials and additional results from ongoing mechanistic studies, initial results show that KKT is potentially an effective treatment for chronic neck pain and may contribute to the reduction of pain relieving medication.  相似文献   
60.
Adverse reactions in blood donors with a history of seizures or epilepsy   总被引:1,自引:0,他引:1  
BACKGROUND: Individuals with epilepsy or seizure disorders are restricted from donating blood because of concern that they are prone to adverse donor reactions such as syncope and convulsions. A study evaluating whether that concern is warranted is reported. STUDY DESIGN AND METHODS: During a 2-year period beginning in 1987, blood donors in Maryland with a history of seizures were actively recruited by the American Red Cross. Adverse donor reactions were classified as "slight", indicating dizziness and nausea without loss of consciousness; "moderate," denoting syncope; and "severe," indicating convulsive syncope. RESULTS: There were 329,143 satisfactory blood donations; 613 individuals reporting a history of seizures donated blood a total of 723 times. Among donors with seizures, 186 (35.7%) were taking antiepileptic medication, and 61 (8.4%) had had one or more seizures in the preceding year. Individuals with seizures had a low incidence of adverse reactions (3.34%). Although this incidence was slightly higher than that in the entire population (2.24%), the difference was not significant. In particular, the risk of syncope with or without convulsive activity was low for people with seizures (0.21%) and not significantly greater than that in other donors (0.28%). CONCLUSION: Individuals with seizures or epilepsy are not at greater risk for adverse reactions after blood donation, and major restrictions on their participation as blood donors are not warranted.  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