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   31篇
  免费   0篇
耳鼻咽喉   1篇
基础医学   1篇
临床医学   10篇
内科学   3篇
皮肤病学   5篇
神经病学   1篇
特种医学   2篇
预防医学   7篇
药学   1篇
  2013年   1篇
  2010年   1篇
  1998年   1篇
  1997年   5篇
  1996年   2篇
  1994年   2篇
  1993年   3篇
  1992年   1篇
  1990年   6篇
  1989年   1篇
  1988年   1篇
  1984年   1篇
  1981年   2篇
  1977年   1篇
  1957年   1篇
  1955年   1篇
  1954年   1篇
排序方式: 共有31条查询结果,搜索用时 17 毫秒
1.
SULKE, A.N., ET AL.: Supraventricular Tachycardia Control with Tachylog 11: Long-Term Follow-Up. Ten patients aged 16–63 years (mean 36.3) had the Siemens P56T "Tachylog II" pacemaker implanted for treatment of drug refractory supraventricular tachycardia. The pacemaker incorporates a noninvasive electrophysiological study (EPS) facility and a sophisticated Holter function combined with a unique "learning" self-search antitachycardia algorithm. The Holter reveals that new tachycardias arise that are not previously detected at conventional EPS. The number of stimuli in the initiation sequences during noninvasive EPS proved highly variable, however, termination sequences remained constant in the long term. There was variability of timing of stimuli in the long term that was significantly greater for "new" tachycardias than for "original" arrhythmias. Long-term follow-up [at 1 month, 6 months, and 1 year] have shown that 90% of patients have good tachycardia control without the need for drugs. All patients confirm the acceptability of this pacemaker for control of their arrhythmias in the long term.  相似文献   
2.
Successful percutaneous ablation of the bundle of His requires accurate localization together with delivery of the minimum effective energy to avoid unwanted effects. The energy output from laser sources can be controlled very precisely but is not easily directed to the bundle of His using conventional fiber optics. The laser thermal probe ("hot tip") consists of an optical fiber and a terminal metal cap that is rapidly heated during energy delivery. When applied to cadaver hearts at energies of 100-150 joules (10 watts for 10-15 seconds) the 2.0-mm diameter peripheral artery probe was able to damage the bundle of His without extensive surrounding damage. The right ventricular free wall and interventricular septum were perforated during some applications at these energies leaving a tract with a diameter of less than 2.0 mm. The atrioventricular (AV) membranous septum, Foramen Ovale, right atrial appendage, and septal leaflet of the tricuspid valve were more resistant at these energy levels and perforations were always less than 1.0 mm in diameter. The probe was modified for use during electrophysiological studies and good quality unipolar electrograms were recorded from the metal cap confirming that the probe could be accurately positioned adjacent to the bundle of His. The laser thermal probe deserves further study as a "self directing" ablation tool.  相似文献   
3.
While the experimental data upon which current concepts in mechanisticallybased risk assessment and molecular epidemiology are groundedderive almost entirely from rodent models, fish models haveseveral attributes (e.g., low background incidence, extremelylow cost tumor studies, nonmammalian comparative status forextrapolation of mechanisms to humans) that make them valuableadjuncts for addressing these concepts. This report providesan initial characterization of the dose dependency of dietaryN-nitrosodiethylamine (DEN) hepatocarcinogenicity in Shastastrain rainbow trout (Oncorhynchus mykiss) and the potentialof DEN to elicit ras proto-oncogene activation in this species.Carcinogen was administered in the diet at five concentrationsfor 12 months. Necropsies were per formed at 9, 12, and 18 months,the latter on fish maintained on control diet for 6 months aftercessation of DEN exposure. The incidence of hepatic neoplasmsat the lower dietary concentrations (70 ppm) did not consistentlyexceed that for control groups, which were higher in this particularstudy (2%) than expected (historically 0.1%). For the higherDEN concentrations, a linear relationship between the hepatictumor incidence (expressed as log odds, log [p/(1-p)1, wherep = proportion of fish bearing tumors), and the logarithm oftotal cumulative dose was observed, with response being independentof the length of time (9 or 12 months) during which the dosewas accumulated. The dose-response curve for fish maintainedan additional 6 months postexposure was shifted toward higherincidence but was parallel to the curve for fish killed at cessationof exposure. The model predicts that doubling the dose willproduce some what more than a doubling of the odds (pl(100 -p) for tumor incidence and that the odds for lesions 6 monthspostexposure will be approximately double those at cessationof exposure. Comparison of these results with previous studiesusing rats suggests an overall similarity in dose-response curves,with trout being somewhat less sensitive than rats to DEN hepatocarcinogenesis. To examine the molecular basis for DEN carcinogenesis in this species, seven liver tumors induced separatelyby short-term DEN treatment were probed by 3'-mismatch primerpolymerase chain reaction analysis for evidence of Ki-ras proto-oncogeneactivating point mutations. A very high proportion (6/7) oftumors was found to carry codon 12 GGA - AGA mutations, whereasno codon 61 mutants were detected in this sample. These initialresults differ from those reported using hepatic tumors fromDEN-treated mice, which exhibit frequent Ha-ras codon 61 mutations[Richardson et al., Carcinogenesis 13, 1277–1279 (1992)]and rats, which appear not to carry DEN-activated ras alleles[Bauer-Hoffman et al., Carcinogenesis 11, 1875–1877 (1990)].Thus the available oncogene data for the common carcinogen DENdo not suggest a simple, consistent oncogenic pathway or mutationalspectrum useful in the molecular epidemiology of human cancers.  相似文献   
4.
Dual sensor ventricular demand rate responsive (VVIR mode) pacing was compared with single sensor rate responsive pacing to assess whether this new development should be more widely incorporated in modern pacemaker devices. A within patient randomized, double-blind crossover study involving ten patients, mean age 67.4 years (70% male), had Medtronic Legend Plus dual sensor VVIR pacemakers implanted for high grade A V block and chronic or persistent paroxysmal atrial fibrillation. Performance values were compared to 20 healthy control subjects of a similar age and gender. Patients were both subjectively and objectively assessed after 2 weeks of out-of-hospital activity in VVIR mode (minute ventilation sensing), VVIR mode (activity sensing), VVIR mode (dual sensor), and VVI mode (no rate response). All patients were assessed for subjective preference for, and objective improvement in, any pacing modality as assessed by standardized daily activity protocols and graded exercise treadmill testing. Subjective perception of exercise capacity and functional status was significantly lower in VVI mode (P < 0.05) compared to any of the VVIR modes, which did not differ. After completion of the study 70% of patients chose VVIR as their preferred mode, with 30% expressing no preference. Forty percent preferred activity sensor WIR mode pacing, 30% preferred dual sensor VVIR mode pacing, and 70% found either dual sensor WIR mode, minute ventilation sensor WIR mode, or both modalities least acceptable. No patient found activity sensing WIR mode least acceptable. Graded treadmill testing revealed significantly lower exercise tolerance during WI mode pacing (P < 0.01) compared to the VVIR modalities, which did not differ. Overall, chronotropic response was best with dual sensor pacing during standardized daily activity protocols and during the standard car journey. The data from this study suggest that there is no marked clinical advantage obtained from the use of dual sensor devices over current activity sensing ventricular demand rate responsive pacemakers, but with the probable added disadvantages of increased size, complexity, cost, and decreased longevity.  相似文献   
5.
Hearing loss and treatment in young Down's syndrome children   总被引:1,自引:0,他引:1  
Summary Twenty-four home-reared Down's syndrome children aged 9–32 months were assessed by trained audiologists on three separate occasions (summer, autumn and spring 1977–1978). Distraction test procedures were used; all failed to pass the screening test and 80–85% registered as having moderate to profound losses. Seventy-five per cent were categorized as having a conductive loss and some improvements were found over the test sessions as a result of surgical and decongestant treatment. Approximately 50% of the infants had been passed on similar screening procedures by the local health services. The results are discussed in relation to language development and service needs.  相似文献   
6.
Summary The paper reports the results of detailed interviews with parents of Down's syndrome infants shortly after their being informed of the diagnosis. It reviews previous studies and confirms a number of findings. 1 The majority of parents wish to be told of the diagnosis as soon as possible and with the spouse present. 2 They do not automatically resent the ‘teller’. 3 They wish to be told directly but sympathetically, in private and have access to the baby. 4 Several interviews are needed at short intervals following the initial telling for parents to ask further questions and to assimilate more information about their child's condition.  相似文献   
7.
Social life of school children with Down''s syndrome   总被引:3,自引:0,他引:3  
Frequency of participation in organized activities and informal play contacts with other children were investigated for a group of 118 children with Down's syndrome. Measures were based on mothers' reports. As part of a study of child and family functioning, a wide range of child, parent and family variables was measured and the relationships of these to the extent of the children's social contacts were investigated in multivariable analyses. Family variables of social class, parental education, marital relationship, and achievement and recreational orientation were found to be significantly related to the measures of the child's social life. In addition, children at the lower end of the IQ range in this sample were likely to have fewer informal play contacts. These results point to the influence of the family in stimulating and maintaining the children's social activities.  相似文献   
8.
Abstract. Platelet size has been shown to reflect platelet activity. We prospectively measured the mean platelet volume (MPV) in 47 patients undergoing single vessel angioplasty for symptomatic angina. The patients underwent repeat angiography 4–8 months later irrespective of symptomatic status. Restenosis was assessed quantitatively by hand held calliper measurements of the lesion and qualitatively by a return of angina, ST segment changes on an exercise test and visual analysis of the lesion severity by two experienced angiogra-phers. Twenty-four patients developed recurrent angina during the follow-up period, the MPV in the group with chest pain was 8.54 ± 0.60 fl compared to 8.1±0.69 fl in the asymptomatic group (P = 0.04). Twenty two patients had significant ST segment changes at exercise. In this group the MPV was 8.6 ± 0.56 fl compared to 8.0 ±0.70 fl for the group with a negative test ( P = 0.002). Similarly visually assessed angiographic stenosis showed a significant increase in the restenotic group (8.6 ± 0.56 vs. 8.0 ± 0.61 fl, P=0.001). The relative odds for developing clinically defined restenosis were 10.2 times greater if the pre-procedural MPV lay in the upper compared to the lowest quartile.
There was a positive correlation between MPV and change in minimal luminal diameter between post angioplasty and follow-up angiography, assessed quantitatively, r=+0.56, P = 0.016. There was no association between clinical or angiographic definitions of restenosis and haemoglobin, red cell count, mean corpuscular volume, white cell count or platelet count. Platelet size may influence the development of restenosis after succeesful coronary angioplasty.  相似文献   
9.
Successful dual chamber pacing was achieved by implanting permanent pacemaker leads using an extra-peritoneal approach to the inferior vena cava in a 48-year-old patient with a single ventricle, transposition of the great vessels, and a right atrial pulmonary artery shunt (Glenn's procedure). The pacemaker generator was implanted into a subcutaneous pockel in the anterior abdominal wall.  相似文献   
10.
Amelanotic lentigo meligna melanoma is rare, only 10 cases over the face having been reported to date in the English literature. In none of these was the diagnosis suspected clinically, being made in all cases only after histopathological examination. We now report an unusual additional case of this uncommon lesion, which quickly progressed from an amclanotic lentigo maligna to an invasive melanoma in a short space of time, and review the literature concerning this condition.  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