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Successive Measurements (successive + measurement)

Distribution by Scientific Domains
Medical Sciences50%

Selected Abstracts

Partial Left Ventriculectomy and Limited Heart Transplantation Availability

JOURNAL OF CARDIAC SURGERY, Issue 2 2001
Ph.D., sa Gradinac M.D.
Background and Aim: Partial left ventriculectomy, a novel cardiac volume reduction operation, is applied in countries without a developed heart transplantation program. We sought to determine its impact in our population of patients. Methods: Partial left ventriculectomy was performed in 38 patients during the last 4 years. Basic inclusion criteria were nonischemic dilated cardiomyopathy and poor response to medical therapy for heart failure. Hemodynamic evaluation was carried out before and after operation. A modified surgical technique of mitral valve repair and ventricle suturing was applied. Results: Thirty-day, 6-month, and 2-year survival rates were 82%± 7%, 65%± 8%. and 61%± 9%, respectively. Duration of heart failure symptoms was the only predictor of survival (p = 0.042). A high proportion of noncardiac causes of death was noted. Functional capacity in surviving patients improved at every successive measurement up to 1 year postoperatively. Conclusions: The introduction of partial left ventriculectomy in a country with limited heart transplantation availability had a great impact on the management of end-stage heart failure and may represent the only surgical option for some patients. The average cost per patient was substantially lower when compared to heart transplantation. [source]

The Influence of the Cathodic Pretreatment on the Electrochemical Detection of Dopamine by Poly(1-aminoanthracene) Modified Electrode

ELECTROANALYSIS, Issue 19 2010
Estela de Pieri Troiani
Abstract In this study we demonstrated the influence of the cathodic pretreatment of poly(1-aminoanthracene) (PAA) electropolymerized on a platinum electrode for determination of dopamine (DA). The DA electrochemical response was obtained after a cathodic pretreatment of the PAA electrode which consisted of applying a potential of ,0.7,V (vs. Ag/AgCl) for 3,s before each measurement. The pretreatment of the electrode changed the PAA electrocatalytic properties so that the electrode began to present electrochemical response to DA without interference of ascorbic acid (AA). The anodic peak currents determined by differential pulse voltammetry using pretreated PAA showed a linear dependence on the DA concentration from 0.56 to 100,µM with a detection limit of 0.13,µM and a correlation coefficient of 0.9986. The electrode exhibits a relative standard deviation of 1.2,% for ten successive measurements of a 0.5,mM DA solution. The analysis by scanning electron microscopy and atomic force microscopy show a homogeneous and nanostructured film with globular structures with diameter of about 20,nm. The analytical results obtained for DA determination at a pretreated PAA electrode in pharmaceutical formulation sample were in good agreement with those obtained by a comparative procedure at a 95,% confidence level. PAA electrode after the pretreatment showed electrochemical responses to DA with excellent selectivity, sensitivity, and high stability without interference of AA. [source]

Methodological issues related to exhaled nitric oxide measurement in children aged four to six years

PEDIATRIC PULMONOLOGY, Issue 2 2005
Edward Napier MBBS
Abstract This study was designed to test five methodological issues related to measurement of fractional exhaled nitric oxide (FENO) in children aged 4,6 years using commercially available apparatus. Participants attended two randomly selected schools. A respiratory questionnaire was completed. Measurements of FENO were made on successive days, using a NIOX® analyzer employing standard or modified methodologies. Ninety-one children participated in the study (mean age, 5.3 years; 46 boys). Using a standard methodology (n,=,61), FENO was successfully measured in 28 (46%) children, 1/12 aged 4 years, 12/25 aged 5 years, and 15/24 aged 6 years (trend test P,=,0.01). On the first assessment, FENO could be determined in more boys than girls (64% vs. 30%, respectively, P,=,0.008), but this gender difference was not apparent on the second assessment. Exhaled NO was reproducible over a 24-hr period; the mean difference between repeated measurements of natural log (ln) FENO was 0.016 parts per billion (ppb) (95% confidence limits, ,0.479, 0.511), n,=,20. Data from 35 assessments showed that values of FENO did not alter over nine individual, successive measurements. Use of a modified methodology in 30 children increased success in obtaining FENO, but these values were unreliable. In conclusion, measurements of FENO can be obtained in the majority of 5- and 6-year-old but not 4-year-old children. Exhaled NO measurements were reproducible over a 24-hr interval, and did not change over up to nine expiratory maneuvers in these young children. Pediatr Pulmonol. 2005; 40:97,104. © 2005 Wiley-Liss, Inc. [source]

Hysteretic magnetoresistance in polymeric diodes

PHYSICA STATUS SOLIDI - RAPID RESEARCH LETTERS, Issue 7-8 2009
Sayani Majumdar
Abstract We report on hysteretic organic magnetoresistance (OMAR) in polymeric diodes. We found that magnitude and lineshape of OMAR depend strongly on the scan speed of the magnetic field and on the time delay between two successive measurements. The time-dependent OMAR phenomenon is universal for diodes made with various polymers. However, the width and magnitude of OMAR varied with the polymeric material. The suggestive reason for this hysteretic behavior is trapped carriers, which in presence of a magnetic field change the ferromagnetic ground-state of the polymer leading to a long spin relaxation time. These experimental observations are significant for clarification of the OMAR phenomenon. (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]