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   981篇
  免费   20篇
  国内免费   1篇
耳鼻咽喉   4篇
儿科学   22篇
妇产科学   28篇
基础医学   65篇
口腔科学   17篇
临床医学   199篇
内科学   298篇
皮肤病学   72篇
神经病学   20篇
特种医学   1篇
外科学   82篇
综合类   2篇
一般理论   7篇
预防医学   57篇
眼科学   31篇
药学   83篇
肿瘤学   14篇
  2015年   10篇
  2013年   22篇
  2012年   7篇
  2011年   6篇
  2010年   24篇
  2009年   33篇
  2001年   15篇
  1999年   24篇
  1998年   44篇
  1997年   50篇
  1996年   50篇
  1995年   28篇
  1994年   30篇
  1993年   40篇
  1992年   28篇
  1991年   23篇
  1990年   21篇
  1989年   25篇
  1988年   23篇
  1987年   24篇
  1986年   24篇
  1985年   19篇
  1984年   18篇
  1983年   21篇
  1982年   20篇
  1981年   20篇
  1980年   18篇
  1979年   25篇
  1978年   10篇
  1977年   13篇
  1976年   15篇
  1975年   17篇
  1974年   13篇
  1973年   13篇
  1972年   6篇
  1971年   17篇
  1970年   8篇
  1969年   6篇
  1968年   9篇
  1967年   12篇
  1966年   11篇
  1965年   7篇
  1962年   12篇
  1961年   8篇
  1960年   11篇
  1959年   7篇
  1958年   8篇
  1957年   15篇
  1956年   9篇
  1955年   8篇
排序方式: 共有1002条查询结果,搜索用时 0 毫秒
51.
52.
International Journal of Paediatric Dentistry 2013; 23: 145–152 Background. Alternatives to vital pulpotomy treatment in primary teeth are being sought because of the high formaldehyde content of traditional formocresol (FC) pulpotomy medicaments. Aim. The aim was to compare the clinical and radiographic success of vital pulpotomy treatment in primary molars using 3% sodium hypochlorite (NaOCl) versus a 1 : 5 dilution of Buckley’s FC. Design. Pulpotomies were performed in primary molars of healthy children between 3 and 10 years old. Sixty‐five primary teeth were randomized into two groups that were evaluated for treatment outcomes. Following treatment, the pulp chamber was filled with zinc oxide eugenol (ZnOE) and restored with a stainless steel crown cemented with glass ionomer cement. Clinical and radiographic outcomes were recorded at 6 and 12 months. Results. The control (FC) and experimental (NaOCl) groups demonstrated 100% clinical success at 6 and 12 months. The NaOCl group had 86% (19/22) radiographic success at 6 months and 80% (12/15) at 12 months. The FC group had 84% (21/25) radiographic success at 6 months and 90% (9/10) at 12 months. No significant differences were found in the radiographic outcomes between the two groups at 6 and 12 months (Fisher’s exact test; P = 0.574 and P = 0.468, respectively). Conclusion. NaOCl demonstrated clinical and radiographic success comparable to FC.  相似文献   
53.
Background: The motives, objectives and design of a multicentreprospective study on job stress, absenteeism and coronary heartdisease in Europe (the JACE study) is presented in this paper.Some specific gaps in the reviewed literature are explicitlytapped into by the JACE study. Its objectives are i) to comparethe distributions of the Karasek job stress scales for the samebroad categories of occupations in different European countries(in males and females), ii) to study the predictive power ofthe job stress scales and the job strain model for one yearof sickness absence (in males and females) and iii) to studythe predictive power of the job stress scales and the job strainmodel for a three year incidence of coronary heart disease (Inmales only). Methods: In answering these questions, relationsare studied controlling for gender, age, level of education,company size, physical work risks and shift work, as well astraditional risk factors for CHD (i.e serum cholesterol, serumHDL cholesterol, smoking habits and blood pressure). The JACEstudy is a Biomed 1 concerted action. The JACE group consistsof eight participating centres from six countries, i.e. fromBelgium and Sweden (two centres), France, Italy, Spain, Swedenand The Netherlands (each one centre). The coordination of thegroup is in Brussels. The participating centres brought in over15, 000 European workers to test the hypotheses.  相似文献   
54.
55.
56.
Drug abuse research and HIV/AIDS: a national perspective from the US   总被引:1,自引:0,他引:1  
The National Institute on Drug Abuse (NIDA), the lead Federal agency charged with research on reducing the demand for illicit drugs in the US, has actively pursued the associated challenge of reducing drugs-related HIV transmission. Drug abuse-related spread of the virus occurs not only through sharing contaminated needles but also sexually to partners and perinatally from infected mothers to their offspring. Through a national research and demonstration program, NIDA supports primary AIDS risk reduction activities focused on identifying effective drug abuse prevention and treatment strategies. AIDS is increasingly a disease found in women, children, minorities, and people who live in rural areas. NIDA's efforts are clearly responsive to the changing nature of this epidemic. Among the many promising initiatives currently underway are a medications development program to find new pharmacotherapies for treating drug addiction; an array of National AIDS Outreach Demonstration Projects implementing alternative control strategies for drug abusers not attracted to or successful in drug abuse treatment; establishment of several treatment research units for designing and conducting studies on treatment effectiveness; and a variety of programs aimed at identifying and potentially reducing the risks of prenatal drug use to both mother and child. Effective dissemination of our findings is particularly critical to the overall impact of our research efforts. Collaborative activities teaming NIDA with a multitude of organizations also addressing AIDS related issues are designed to provide a synergistic impact on this complex and multifaceted public health crisis.  相似文献   
57.
Catheter ablation of AV conduction with radiofrequency energy can be challenging in the presence of structural abnormalities of the AV junction, either congenitally or after reconstructive surgery. We used transcoronary ethanol to ablate the AV node in a patient with classic tricuspid atresia and refractory intraatrial reentry tachycardia. This approach provides an alternative means of creating complete heart block with catheter-based techniques, when radiofrequency catheter ablation is technically impossible or ineffective.  相似文献   
58.
Effect of Obesity and OSA on Outcomes Post AF Ablation . Background: Obesity and obstructive sleep apnea (OSA) have a strong association with atrial fibrillation (AF). The purpose of this study was to prospectively determine the effects of obesity, assessed by the body mass index (BMI) and OSA on the efficacy of catheter ablation of AF. Methods: The patient population consisted of 109 patients (mean age: 60 ± 10 years, 79% male, 67% paroxysmal, mean BMI 28 ± 5 kg/m2) who underwent catheter ablation of AF. Based on BMI, patients were classified as normal (<25 kg/m2), overweight (≥25 and <30 kg/m2), or obese (≥30 kg/m2). OSA was assessed by the Berlin questionnaire. Clinical success was defined as at least 90% reduction in AF burden after 3‐month blanking period. Mean duration of follow‐up was 11 ± 4 months. Results: Of the 75 patients with clinical success, 25 (33%) had normal BMI, 29 (39%) were overweight, and 21 (28%) were obese. Among the 34 patients with failed outcome, 5 (15%) had normal BMI, 14 (41%) were overweight, and 15 (44%) were obese (P = 0.04). Twenty‐eight of the 48 patients with OSA (58%) had clinical success as opposed to 47 of the 61 patients (77%) without OSA (P = 0.036). On multivariate analysis, only BMI emerged as an independent predictor of procedural failure ((OR 1.11, CI: 1.00–1.21, P = 0.03). Conclusions: The results of this prospective study show that obesity, a modifiable risk factor, is an independent predictor of procedural failure after catheter ablation of AF. Whether treating obesity may improve the results of catheter ablation of AF warrants further investigation. (J Cardiovasc Electrophysiol, Vol. 21, pp. 521‐525, May 2010)  相似文献   
59.
Pediatric Ablation Charges and Costs Are Rising. Introduction: Catheter ablation has been shown to be effective for pediatric tachyarrhythmias, but the associated charges and costs have not been described in the recent era. Understanding such contemporary trends may identify ways to keep an effective therapy affordable while optimizing clinical outcomes. Methods: We used the 1997–2009 Kids’ Inpatient Databases to examine trends in charges and costs for pediatric catheter ablation and identify determinants of temporal changes. Results: There were 7,130 discharges for catheter ablation in the sample. Mean age at ablation was 12.1 ± 0.2 years. Patients with congenital heart disease (CHD) made up 10% of the sample. Complications occurred in 8% of discharges. Mean total charges rose 219% above inflation (from $23,798 ± 1,072 in 1997 to $75,831 ± 2,065 in 2009). From 2003 to 2009, costs rose 25% (from $20,459 ± 780 in 2003 to $25,628 ± 992 in 2009). Charges for ablation increased markedly relative to surgical procedures, but with a similar slope to other catheter‐based interventions. Multivariable analysis revealed that year (P < 0.0001), payer (P = 0.0002), CHD (P < 0.0001), valvular heart disease (P = 0.0004), cardiomyopathy (P = 0.0009), hospital region (P < 0.0001), length of stay (P < 0.0001), and complications (P < 0.0001) predicted increased charges. The same factors also predicted increased costs. Charges and costs varied considerably by region, particularly for high‐volume centers (P < 0.0001). Conclusions: Charges and costs for pediatric catheter ablation increased relative to other procedures and significantly outstripped inflation. Further study of complications, length of stay, and regional differences may help control rising costs while maintaining quality of care. (J Cardiovasc Electrophysiol, Vol. 24, pp. 162‐169, February 2013)  相似文献   
60.
Background: Right ventricular apical (RVA) pacing promotes tricuspid regurgitation (TR), electromechanical dyssynchrony, and ventricular dysfunction. We tested a novel intramyocardial bipolar lead to assess whether stimulation of the atrioventricular septum (AVS) produces synchronous ventricular activation without crossing the tricuspid valve (TV). Methods: A lead with an active external helix and central pin was placed on the AVS and the RVA in three dogs. High‐density electroanatomic (EA) mapping was performed of both ventricles endocardially and epicardially. Intracardiac echocardiography was used to access ventricular synchrony. Results: The lead was successfully deployed into the AVS in all cases with consistent capture of the ventricular myocardium without atrial capture or sensing. The QRS duration was less with AVS compared with RVA pacing (89 ± 4 ms vs. 100 ± 11 ms [P < 0.0001, GEE P = 0.03]). There was decreased delay between color Doppler M‐mode visualized peak contraction of the septum and the mid left ventricular free wall with AVS compared with RVA pacing (89 ± 91 ms vs. 250 ± 11 ms [P < 0.0001, GEE P = 0.006]). Activation time between the mid septum and mid free wall was shorter with AVS versus RVA pacing (20.4 ± 7.7 vs. 30.8 ± 11.6 [P = 0.01, GEE P = 0.07]). The interval between QRS onset to earliest free wall activation was shorter with AVS vs. RVA pacing (19.2 ± 6.4 ms vs. 31.1 ± 11.7 ms [P = 0.005, GEE P = 0.02]). Conclusion: The AVS was successfully paced in three dogs resulting in synchronous ventricular activation without crossing the TV.  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