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   411篇
  免费   12篇
  国内免费   29篇
耳鼻咽喉   7篇
儿科学   11篇
妇产科学   5篇
基础医学   35篇
口腔科学   4篇
临床医学   61篇
内科学   82篇
皮肤病学   1篇
神经病学   15篇
特种医学   91篇
外科学   15篇
综合类   12篇
预防医学   43篇
眼科学   24篇
药学   32篇
中国医学   1篇
肿瘤学   13篇
  2021年   3篇
  2019年   4篇
  2018年   7篇
  2016年   1篇
  2015年   7篇
  2014年   5篇
  2013年   18篇
  2012年   14篇
  2011年   23篇
  2010年   11篇
  2009年   9篇
  2008年   6篇
  2007年   28篇
  2006年   13篇
  2005年   23篇
  2004年   18篇
  2003年   13篇
  2002年   10篇
  2001年   13篇
  2000年   10篇
  1999年   6篇
  1998年   14篇
  1997年   11篇
  1996年   8篇
  1995年   8篇
  1994年   12篇
  1993年   14篇
  1992年   9篇
  1991年   8篇
  1990年   12篇
  1989年   13篇
  1988年   14篇
  1987年   7篇
  1986年   9篇
  1985年   9篇
  1984年   12篇
  1983年   5篇
  1982年   4篇
  1981年   5篇
  1980年   8篇
  1979年   1篇
  1978年   6篇
  1977年   10篇
  1976年   5篇
  1975年   3篇
  1973年   1篇
  1970年   1篇
  1939年   1篇
排序方式: 共有452条查询结果,搜索用时 15 毫秒
101.
Many nursing home transition barriers are manmade and avoidable. PPACA is encouraging improvement and reduced unnecessary hospitalizations through incentives and penalties. Providers are responding through a variety of internal and collaborative models. The resulting communication, technology, education, and emphasis can improve the quality of life for the people served.  相似文献   
102.
103.
The authors describe two cases of chronic ocular surface disorder caused by the use of soft contact lenses. These cases demonstrated persistent corneal epithelial abnormalities, indolent ulceration, superficial stromal scarring, peripheral vascularization, and decreased visual acuity (worse than 20/400). Both cases were refractory to medical management, including discontinuation of contact lenses and topical medications. Autologous conjunctival transplantation restored the ocular surface with the return of good visual acuity (better than 20/40). Tissue culture demonstrated a decreased replication rate in the limbal epithelial cells, which suggests that epithelial stem cell dysfunction may be responsible for this ocular surface disease.  相似文献   
104.
Hispanics are twice as likely as non-Hispanic Whites to have diabetes and are also at higher risk for diabetes-related complications and poorer outcomes. The prevalence of diabetes is inversely related to educational status. Low literacy is common, especially among older Hispanics. Little literature exists on formative research to create diabetes education materials for this audience. Two focus groups assessed views and preferences for diabetes education of low-literate, low-income, non-English-speaking urban Caribbean and Central American Hispanics with diabetes, as well as utility of materials developed specifically for this population, as part of the preliminary work for a pilot study of a diabetes intervention. Implications for practitioners and researchers are discussed.  相似文献   
105.
A computerized method that requires only 1-2 minutes to quantify gallbladder volume from real-time sonograms is described. This time is considerably shorter than that required using the hand-calculation method. There was a highly significant correlation between gallbladder volumes calculated by computer and hand (r = 0.97; P less than .001).  相似文献   
106.
Conway  WF; Hayes  CW 《Radiology》1989,173(2):569-570
To decrease examination time, the authors used a contrast agent with a low iodine concentration for three-compartment (radiocarpal joint, distal radioulnar joint, midcarpal compartment) wrist arthrography. The material was used in 24 patients. Many patients demonstrated dissipation of contrast material in the radiocarpal joint by 30 minutes after injection. By 45 minutes, all patients demonstrated sufficient dissipation to permit the second injection. The technique produces diagnostic images and reduces the time required for the study.  相似文献   
107.
OBJECTIVE: The objective of this study was to determine the efficacy and safety of mepivacaine paracervical block in term, low-risk obstetric patients. STUDY DESIGN: Over a 3-year period all term, low-risk obstetric patients in the author's private practice were offered mepivacaine paracervical block anesthesia. One hundred eighty-two patients received 200 mg mepivacaine with each block. The patients who declined paracervical block were used as a control group to compare Apgar scores, subject to chi 2 analysis. RESULTS: Initial injections were 97.3% successful. Average duration of anesthesia was 59.7 minutes with the first injection. Fetal bradycardia occurred in 13.2% with an average duration of 4.5 minutes. The slightly higher incidence of low Apgar scores at 1 and 5 minutes in the study group was not statistically significant. One neonatal death occurred secondary to group B streptococcal sepsis in the study group. CONCLUSION: Mepivacaine paracervical block remains an anesthetic option in low-risk patients. The high success rate is limited by its short duration of action and the incidence of fetal bradycardia.  相似文献   
108.
Retroperitoneal hematoma after blunt trauma.   总被引:13,自引:0,他引:13  
We reviewed retrospectively 233 consecutive patients with retroperitoneal hematoma (RPH) resulting from blunt trauma. This study group represented 2.9 per cent of all admissions for blunt trauma and 13 per cent of all admissions for blunt abdominal trauma. Motor vehicle accidents predominated as the cause of injury. Fifty-five per cent of the patients had fractures of the pelvis. Laparotomy was the primary method used in diagnosing RPH (73 per cent). The RPH was located in zone I in 14 per cent of patients, zone II in 37 per cent, zone III in 46 per cent and zone IV in 3 per cent. The RPH was explored in 35 per cent of all patients. Major vessels were the most common organ system injured (21 per cent) in patients with zone I RPH. The kidney was the most commonly injured organ (27 per cent) in patients with zone II RPH. Injury of either the pancreas or duodenum in 14 per cent of patients with right-sided zone II RPH indicates the need for careful evaluation of those organs at operation. Patients with zone III RPH associated with fractures of the pelvis should be explored only rarely--when main iliac vascular injury is suspected (4.6 per cent in this series). Otherwise, a systematic approach using external fixator devices and angiographic embolization should be used. The over-all morbidity and mortality rates of 59 and 39 per cent, respectively, emphasize the need for aggressive resuscitation, rapid control of hemorrhage and a multidisciplinary approach to the management of these patients.  相似文献   
109.
学术背景:胚胎干细胞无论对转基因动物的制备还是对疾病的治疗都具有巨大的潜能,但前提是用于治疗的胚胎干细胞具有其特有的多能性和全能性,而FoxD3在胚胎发育和维持胚胎干细胞多能性都具有重要作用。目的:了解FoxD3在胚胎发育和维持胚胎干细胞多能性的作用。检索策略:应用计算机检索Pubmed1996—09/2007—05期间的相关文章,检索词为“FoxD3”,限定语言种类为英文。检索到67篇文章,排除重复的和与胚胎发育和胚胎干细胞相关性不大的文章,共纳入32篇文献。文献评价:32篇文献中分别涉及胚胎干细胞转录调节、FoxD3在胚胎发育和维持胚胎干细胞多能性的作用及其Foxd3在其他细胞中(骨髓细胞、神经嵴细胞、色素细胞)的功能等方面的内容,资料综合:胚胎干细胞具有其他细胞不可比拟的特性使胚胎干细胞应用广泛,要合理控制胚胎干细胞在体内和体外的分化,关键要了解那些控制胚胎干细胞命运的基因。FoxD3是叉头框(Forkheadbox,Fox)家族中的一个转录调控因子,它对胚胎上胚层及其衍生物的形成和建立多潜能胚胎干细胞系具有重要作用,并与控制胚胎发育和胚胎干细胞多能性的其他转录调控因子有一定的联系。结论:FoxD3是维持胚胎上胚层细胞多潜能性和在体外建立胚胎干细胞系所必需的。  相似文献   
110.
目的:观察不同睡眠剥夺时间后力竭运动对大鼠胸腺谷胱甘肽、丙二醛含量和超氧化物歧化酶活性的变化,探讨睡眠剥夺对大鼠抗氧化能力的影响。方法:实验于2006-04/05在湖南师范大学体育学院运动生物化学实验室完成。实验分组:选择10周龄健康雄性SD大鼠30只,按随机数字表法分为5组,每组6只:睡眠非运动组,睡眠 力竭运动组和睡眠剥夺24,48,72h 力竭运动组。实验方法:①采用轻柔刺激法制备大鼠睡眠剥夺模型。②睡眠非运动组和睡眠 力竭运动组不进行睡眠剥夺。③睡眠 力竭运动组和睡眠剥夺各组大鼠运动方案:跑台坡度为10°,速度为19.3m/min(相当于76%VO2max),所有大鼠运动至力竭(运动末期,大鼠先后滞留跑道后1/3处达3次以上,各种刺激驱赶均无效,停跑后体征表现为呼吸急促,神情倦怠,腹卧位,对刺激反应迟钝,捕捉时,逃避反应较运动前减弱)。实验评估:①大鼠一般状态。②力竭时间。③大鼠力竭后麻醉处死,测定胸腺谷胱甘肽、丙二醛含量和超氧化物歧化酶活性。结果:纳入大鼠30只,均进入结果分析。①大鼠一般状态:睡眠 力竭运动组大鼠表现为形态正常,活泼好动,皮毛光亮,眼睛有神;睡眠剥夺48,h 力竭运动组大鼠均出现神态倦怠,眼神黯淡,四肢亦有不同程度的红肿;睡眠剥夺24h 力竭运动组大72鼠介于以上两者之间。②睡眠 力竭运动组和睡眠剥夺24,7248,h组大鼠的力竭时间分别为(232.36±37.67),(269.19±38.61),(162.42±35.70),(141.07±28.56)。③谷胱甘肽含量、超氧化物歧化酶活性:睡眠 力竭运动组谷胱甘肽含量和超氧min化物歧化酶活性均低于睡眠非运动组[分别为(25.54±0.79),(27.09±1.31)mg/g;(±0.21),(±0.10)mkat/g],差异有显4.594.88著性意义(P<0.05);睡眠剥夺24h 力竭运动组谷胱甘肽含量和超氧化物歧化酶活性均高于睡眠非运动组[分别为(28.60±0.96),(27.09±1.31)mg/g;(±0.10),(±0.10)5.234.88mkat/g],差异有显著性意义(P<0.05),睡眠剥夺48,h 力竭运动组P72均低于睡眠非运动组[分别为(23.74±1.19),(22.43±0.52),(27.09±1.31)mg/g;(±0.14),(±0.18),(±0.10)mkat/g],4.523.354.88差异均有非常显著性意义(P<0.01);睡眠剥夺各组与睡眠 力竭运动组间谷胱甘肽含量和超氧化物歧化酶活性差异均有非常P显著性意义(P<0.01);睡眠剥夺各组间比较差异有显著性意义(P<0.05)。④丙二醛浓度:睡眠 力竭运动组丙二醛浓度高于P睡眠非运动组[分别为(±0.27),(±0.24)μmol/L],差异有非常显著性意义(P<0.01);睡眠剥夺各组与睡眠非运动组之间6.565.35P差异均有非常显著性意义(P<0.01);睡眠剥夺24,48,72h 力竭运动组丙二醛含量均高于睡眠 力竭运动组[分别为(±0.12),(±P7.398.850.72),(10.89±0.82),(±0.27)μmol/L],差异有显著性意义(P<0.05;P<0.01);睡眠剥夺各组间比较,睡眠剥夺48h与睡眠剥夺24h差6.56异无显著性意义(P>0.05),睡眠剥夺72h与睡眠剥夺24h、睡眠剥夺72h与睡眠剥夺48h间比较差异有非常显著性意义(P<0.01)。结论:①睡眠剥夺24h可引起大鼠胸腺氧化应激,使氧自由基能力有所增强。②睡眠剥夺48,72h力竭运动后氧自由基能力降低。  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