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   323篇
  免费   17篇
耳鼻咽喉   4篇
儿科学   9篇
妇产科学   17篇
基础医学   38篇
口腔科学   5篇
临床医学   47篇
内科学   82篇
皮肤病学   14篇
神经病学   9篇
特种医学   1篇
外科学   61篇
综合类   1篇
预防医学   5篇
眼科学   2篇
药学   40篇
肿瘤学   5篇
  2017年   3篇
  2016年   5篇
  2015年   8篇
  2014年   4篇
  2013年   10篇
  2012年   4篇
  2011年   2篇
  2010年   11篇
  2009年   9篇
  2008年   3篇
  2006年   4篇
  2005年   2篇
  2004年   2篇
  2003年   3篇
  2001年   5篇
  1999年   4篇
  1998年   13篇
  1997年   11篇
  1996年   16篇
  1995年   9篇
  1994年   13篇
  1993年   11篇
  1992年   5篇
  1991年   11篇
  1990年   7篇
  1989年   5篇
  1988年   2篇
  1986年   2篇
  1985年   3篇
  1984年   2篇
  1983年   6篇
  1981年   2篇
  1980年   3篇
  1979年   3篇
  1978年   2篇
  1977年   2篇
  1966年   1篇
  1965年   2篇
  1964年   1篇
  1959年   7篇
  1958年   17篇
  1957年   15篇
  1956年   21篇
  1955年   27篇
  1954年   21篇
  1950年   2篇
  1949年   1篇
  1948年   3篇
  1947年   1篇
  1937年   2篇
排序方式: 共有340条查询结果,搜索用时 15 毫秒
61.
PURPOSE: We address long-term within individual variation of serum prostate specific antigen (PSA) in men without clinical or biopsy evidence of prostate cancer. MATERIALS AND METHODS: We studied 943 men from a prostate cancer screening program with 2 PSA (PSA1 and PSA2) measurements available. A third PSA (PSA3) was obtained from 571 men. Only participants with no clinical evidence of cancer were included in the study. Within individual PSA variability was calculated based on indexes of percent coefficient of variation, ratio difference and PSA velocity. The relationship among these indexes, interval between measurements and number of PSA samples was assessed. RESULTS: Mean interval was 670.4 days between PSA1 and PSA2, and 801.8 days between PSA2 and PSA3 (p<0.001). Mean coefficient of variation was 18% after 2 and 15.7% after 3 PSA measurements. Mean ratio differences were -0.047 ng./ml. for 2 and 0.033 ng./ml. for 3 samples. Mean PSA velocity was -0.128 ng./ml. per year for 2 and -0.055 ng./ml. per year for 3 samples, with 95% confidence intervals of 0.634 and 0.315, respectively. Variability was higher if only 2 PSA measurements were done (p<0.001). No clear relationship was found between individual variability and interval between measurements. CONCLUSIONS: PSA velocity is within normal limits in almost all men (more than 95%) without clinically relevant prostate cancer. PSA individual variability is not fully dependent on the time between measurements when intervals are long, and can be substantially decreased with a third PSA sample.  相似文献   
62.
AMOXICILLIN AND CLAVULANIC ACID IN THE TREATMENT OF ACTINOMYCETOMA   总被引:1,自引:0,他引:1  
Background. Mycetoma is a relatively frequent disease in tropical countries. Drugs commonly used need a long period of treatment, and some cases are resistant to these drugs, especially those with bone or visceral involvement. The combination of amoxicillin-clavulanic acid has shown effectiveness against strains of Nocardia brasiliensis in vitro. Methods. We have used this combination in two cases of mycetoma caused by N. brasiliensis, both with bone involvement and resistance to the drugs usually used. A dose of three tablets a day for 5 to 6 months was given (each tablet contains 500 mg of amoxicillin and 125 mg of clavulanic acid). Results. Clinical and mycologic amelioration was observed in the two cases after completing the treatment. There were no side effects or relapses after 3 to 6 months of follow-up after treatment. Conclusions. We propose this antibiotic as a new option for the treatment of some special cases of actinomycetoma with bone or visceral involvement or resistance to the drugs commonly used in this disease.  相似文献   
63.
A family is described in which two sisters and their two female fifth-cousins were cases of mandibuloacral dysplasia. This syndrome is characterized by mandibular hypoplasia, delayed cranial suture closure, dysplastic clavicles, abbreviated terminal club-shaped phalanges associated with acroosteolysis and atrophy of the skin over hands and feet. Furthermore, in this family alopecia and loss of the lower teeth were noted. We stress the importance of the cutaneous alterations and the possible existence of partial forms of the disease as in one of the patients presented.  相似文献   
64.
Objective: To compare the rates of all-cause mortality in recipients of cardiac resynchronization therapy devices without (CRT-PM) versus with defibrillator (CRT-D).
Methods: Between February 1999 and July 2004, 233 patients (mean age = 69 ± 8 years, 180 men) underwent implantation of CRT-PM or CRT-D devices. New York Heart Association (NYHA) heart failure functional class II was present in 11%, class III in 69%, and class IV in 20% of patients; mean left ventricle ejection fraction (LVEF) was 26.5 ± 6.5 %, 48% presented with idiopathic dilated cardiomyopathy and 49% with ischemic heart disease. Cox multiple variable regression analysis was performed in search of predictors of death.
Results: The clinical characteristics of the 117 CRT-PM and 116 CRT-D recipients were similar, except for LVEF (28.2 ± 6.2% vs 25.0 ± 6.5%, respectively; P < 0.001), and ischemic versus nonischemic etiology of heart failure (41% vs 56%, respectively P = 0.02). Over a mean follow-up of 58 ± 15 months, no significance difference in overall mortality rate was observed between the two study groups. Male sex, NYHA functional class IV, and atrial fibrillation at implant were significant predictors of death.
Conclusions: There was no difference in long-term survival rate among patients with CRT-D versus CRT-PM, although CRT-D more effectively lowered the sudden death rate. Male sex, NYHA functional class IV, and atrial fibrillation predicted the worst prognosis.  相似文献   
65.
POLLAK, W.M., et al. : Clinical Utility of Intraatrial Pacemaker Stored Electrograms to Diagnose Atrial Fibrillation and Flutter. The purpose of this study was to determine if intraatrial electrograms (EGMs) are required to diagnose specific types of atrial tachyarrhythmias detected by pacemaker diagnostics. DDD pacemakers in 56 patients were programmed to store episodes of atrial tachyarrhythmias. Some episodes had a stored atrial EGM snapshot of the atrial tachyarrhythmia. The EGMs were analyzed to confirm whether the stored episodes were true atrial tachyarrhythmias or other pacemaker-sensed events. EGM confirmation of atrial tachyarrhythmias correlated with increasing duration and rate of episodes. In particular, using EGMs, 8 (18%) of 44 episodes < 10 seconds in duration confirmed atrial tachyarrhythmias compared to 16 (89%) of 18 episodes > 5 minutes in duration (  P < 0.001  ). Only 10 (18%) of 56 detected atrial arrhythmia episodes at rates < 250 complexes per minute were confirmed by the atrial EGM as true arrhythmias compared to 33 (57%) of 58 detected episodes at rates > 250/min (  P < 0.001  ) Twenty-nine (91%) of 32 EGM confirmed episodes of atrial fibrillation/flutter had an atrial rate > 250 complexes per minute and were a minimum of 10 seconds in duration. Fifteen (88%) of 17 episodes meeting the combined stored data criteria of > 250 complexes per minute and duration > 5 minutes were confirmed as atrial fibrillation or flutter by stored EGMs. Atrial EGMs identified that 71 (62%) of 114 stored high atrial rate (HAR) episodes were events other than true atrial tachyarrhythmias. Pacemaker diagnostic data with intraatrial EGMs can diagnose specific atrial tachyarrhythmias and identify other pacemaker-sensed events. Stored episodes > 250 complexes per minute and > 5 minutes in duration had a high correlation with atrial fibrillation and flutter.  相似文献   
66.
PURPOSE: Management of neurogenic incontinence is complex and available treatments are not satisfactory. Nociceptin/orphanin FQ, a recently discovered neuropeptide, has been reported to inhibit the voiding reflex in the rat. These experimental results prompted us to investigate the urodynamic and clinical effects of intravesical instillation of nociceptin/orphanin FQ in humans. MATERIAL AND METHODS: Our study involved 5 normal subjects (group 1) with a mean age of 40.4 years (range 21 to 54) and 9 patients (group 2) 40.4 years (24 to 54). All patients in group 2 presented with detrusor hyperreflexia refractory to standard therapy. They were invited to undergo a filling cystometrogram with saline solution and after 30 minutes, a new one with a solution containing 1 microM. nociceptin/orphanin FQ. The urodynamic parameters that were recorded included bladder capacity, volume threshold for the appearance of detrusor hyperreflexia and maximum bladder pressure. Clinical and urodynamic followup was performed after 15 days. The data were statistically analyzed with 1-way analysis of variance followed by the Dunnett test for multiple comparison considered statistically significant with p <0.05. RESULTS: Intravesical instillation of 1 microM. nociceptin/orphanin FQ in group 1 did not produce significant functional changes. This infusion in group 2 produced a statistically significant increase in mean bladder capacity and volume threshold for the appearance of detrusor hyperreflexia from 164 plus or minus standard deviation (SD) 84 to 301 +/- 118 and 93 plus or minus SD 41 to 231 +/- 104 ml. (p <0.05, respectively). Mean maximum bladder pressure decreased from 79 plus or minus SD 25 to 54 +/- 44 cm. water but was not statistically significant (p = 0.19). After 15 days an absence of clinical improvement was noticed in group 2, and the urodynamic control did not show any significant changes compared to the values before nociceptin/orphanin FQ treatment. No severe symptomatic reactions were observed during infusion of 1 microM. nociceptin/orphanin FQ. CONCLUSIONS: Our results demonstrate that nociceptin/orphanin FQ is able to elicit a robust inhibitory effect on voiding reflex in group 2 but not 1. The ideal dosage, route of administration of nociceptin/orphanin FQ and treatment interval are not yet established.  相似文献   
67.
POROKERATOSIS OF MIBELLI AND HIV-INFECTION   总被引:1,自引:0,他引:1  
Background. The exacerbation of porokeratosis of Mibelli associated with inmunosuppression has been well documented. Materials and Methods. We describe the clinical and histologic data of three cases of HIV-infected patients, who developed porokeratosis following HIV-contact. Results. The three reported patients were found to have the clinical and histologic features of porokeratosis of Mibelli. Either the exacerbation or development of the disease followed HIV infection. Conclusion. Although porokeratosis is not a disease indicative of AIDS, its flare-up or its presence in HIV-infected patients may serve as a marker of inmunodeficiency.  相似文献   
68.
69.
70.
Pocket hematoma is a common complication of cardiac implantable electronic device procedures and a potential risk factor for device infections, especially in patients on oral anticoagulation or antiplatelet treatment. There is a wide variability in the incidence of pocket hematoma and bleeding complications in the literature and the major cause for this seems to be the variability of the used definitions for hematomas. The lack of generally accepted definition for pocket hematoma renders the comparisons across the studies difficult. In this article, we briefly review the current literature on this issue and propose a uniform definition for pocket hematoma and criteria for grading the severity of hematoma in clinical practice and research.  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