Search results for "Repeatability"
showing 10 items of 214 documents
Repeatability of lifetime exercise reporting
2001
The purpose of the study was to determine the reliability of lifetime exercise data obtained through a structured interview. Interviews were conducted in 1992-1993 and repeated in 1997 in 150 monozygotic male twins, aged 35-69 years, from the population-based Finnish Twin Cohort. Exercise mode, frequency, duration, intensity and period of participation were solicited for each regularly performed exercise from 12 years of age to the present. Questions related to the most common exercise mode reported in the initial interview were repeated in all subjects and the entire exercise interview was repeated in a subgroup of 38 subjects. The repeatability was highest for exercise years and mean hour…
Fast simultaneous determination of prominent polyphenols in vegetables and fruits by reversed phase liquid chromatography using a fused-core column
2015
A reversed-phase high-performance liquid chromatography method with photodiode array detection has been developed enabling the joint determination of 17 prominent flavonoids and phenolic acids in vegetables and fruits. A multi-segmented gradient program using a fused-core column for the separation of several phenolic classes (phenolic acids and flavonoids) has been optimised. The influence of extraction conditions (sample freeze-drying, ultrasound extraction, solvent composition and extraction time) has been also optimised using response surface methodology with tomato samples as a model. Complete recoveries (76-108%) were obtained for the phenolic compounds present in tomato. The developed…
Analysis of insecticides in honey by liquid chromatography–ion trap-mass spectrometry: Comparison of different extraction procedures
2010
The feasibility of different extraction procedures was tested and compared for the determination of 12 organophosphorus and carbamates insecticides in honey samples. In this sense, once the samples were pre-treated - essentially dissolved in hot water by stirring - and before they could be analyzed by liquid chromatography-ion trap-second stage mass spectrometry (LC-MS(2)), four different approaches were studied for the extraction step: QuEChERS, solid-phase extraction (SPE), pressurized liquid extraction (PLE) and solid-phase microextraction (SPME). The main aim of this work was to maximise the sensitivity of pesticides and to minimise the presence of interfering compounds in the extract. …
Gas chromatographic determination of organochlorine pesticides in cow milk.
2004
A gas chromatographic method of use in determining the following organochlorine pesticides in cow milk has been adapted and validated: alpha-hexachlorocyclohexane (alpha-HCH), beta-HCH, lindane, delta-HCH, hexachlorobenzene, aldrin, heptachlor, heptachlor epoxide, mirex, 2,4-dichlorodiphenyltrichloroethane (2,4-DDT), 4,4-DDT, 2,4-dichlorodiphenyldichloroethane (2,4-DDD), 4,4-DDD, 2,4-dichlorodiphenylethane (2,4-DDE) and 4,4-DDE. The method studied consists of three steps: the extraction of fat by centrifugation, mixing with anhydrous sodium sulfate, and transfer to a glass column and elution with hexane; purification of the extract via concentrated sulfuric acid treatment; and determination…
Assessment of Osstell ISQ's reliability for implant stability measurement: a cross-sectional clinical study
2013
Resonance frequency analysis (RFA) allows assess implant stability by measuring implant oscillation frequency on the bone. RFA is an objective and non-invasive method for implant stability measurement, although scarce evidence has been provided so far on its reliability. Objectives: Assess the Osstell ISQ system's reliability (i.e., its measurement reproducibility and repeatability) by means of the intraclass correlation coefficient (ICC) as statistical method. Study Desing: Implants stability registers were completed by means of Osstell ISQ on 85 implants on 23 patients. Six measurements were completed on each implant by means of two different SmartPegs (types I and II); that is, three con…
Intra‐ and inter‐instrument reliability of the Actiwatch 4 accelerometer in a mechanical laboratory setting.
2012
Intra- and Inter-Instrument Reliability of the Actiwatch 4 Accelerometer in a Mechanical Laboratory Setting This study aimed to quantify the intra-and inter-instrument reliability of the Actiwatch 4 accelerometer (AW4) in a mechanical setting. Twenty seven AW4 were attached to an isokinetic dynamometer and subjected to angular acceleration for 30 min at 50 deg/sec representing moderate intensity (MPA condition) and 200 deg/sec representing vigorous intensity (VPA condition), with a repeat trial conducted. Reliability was assessed using coefficient of variation (CV), absolute percent error (APE), and intraclass correlation coefficients (ICC). Mean AW4 activity counts displayed acceptable rel…
Comparison of two melting range analysis methods with lactitol monohydrate
2001
Abstract In pharmacopoeia, the melting point is determined by a standard method with a melting point instrument. The melting point can also be determined with differential scanning calorimetry (DSC). In this study, the standard method and DSC method are compared for determining the melting range of lactitol monohydrate. The effect of initial temperature, grinding, and drying on the melting range of different lactitol monohydrate samples was studied by a melting point instrument. The melting point and melting enthalpy of the stable form of lactitol monohydrate was identified by DSC. The statistical analysis of the results is based on a t-test. All studied variables had a small effect on the …
Validity and Reliability of a Single Question for Leisure-Time Physical Activity Assessment in Middle-Aged Women.
2020
Purpose: To investigate the validity and test–retest reliability of a single seven-level scale physical activity assessment question (SR-PA L7) and its three-level categorization (SR-PA C3). Methods: The associations of SR-PA L7 and C3 with accelerometer-measured leisure-time physical activity (ACC-LTPA) and with the results of four different physical performance tests (6-min walk [n = 733], knee extension [n = 695], vertical jump [n = 731], and grip force [n = 780]) were investigated among women aged 47–55 years participating in the Estrogenic Regulation of Muscle Apoptosis study (n = 795). The reliability was studied using Spearman correlations with 4-month test–retest period (n = 152). R…
Reliability and Intersession Agreement of Microperimetric and Fixation Measurements Obtained with a New Microperimeter in Normal Eyes.
2015
Purpose: To evaluate the reliability and intersession agreement of measurements of retinal sensitivity as well as of the fixation pattern obtained in healthy eyes with a microperimeter integrating the mechanism of the scanning laser ophthalmoscope (SLO) with the static perimetry. Methods: This study included a sample of 44 healthy eyes of 44 subjects of a mean age of 27.0 ± 8.5 years. In all cases, microperimetric exams with the MAIA system (Centervue, Padova, Italy) were performed in three different sessions to evaluate the intersession repeatability. The consistency of measurements was analyzed by using the Friedman test and by analyzing the correlation between consecutive measurements. A…
Multicommutation cold vapour atomic fluorescence determination of Hg in water.
2002
Abstract A multicommutation-based method has been developed for the on-line direct atomic fluorescence spectrometric (AFS) determination of Hg in waters without any previous sample treatment. The performance of the proposed procedure has been compared with that of a conventional AFS system based on continuous mode measurements. In short, the use of multicommutation, together with a reduction of the size of the liquid–gas phase separator, provides an increase of the laboratory productivity by improving the sample throughput by a factor of 3.6 and strongly reduces the sample consumed by a factor of 6 and reagent consumed by a factor of 8.4. The waste generation is reduced by a factor of 2.4 a…