Search results for "Reproducibility"

Ein unabh�ngiges Verfahren zur Messung der Zusammensetzung von Gasgemischen mit Hilfe der Gaschromatographie

1977

The volume fraction of gas mixtures may be measured gas chromatographically by application of the 100% method, provided they can be separated. In case of gases it is not necessary to calibrate with another method. The specific character of the detector signals can be eliminated by measurements with pure components. The procedure is compared with the Scholander method. In case of O2/N2 mixtures the results agree within reproducibility, but in case of O2/CO2/N2 mixtures a systematic deviation of the CO2 fractions to smaller values is found as concerns the Scholander method. A gas mixture with 5.6 Vol% CO2 shows a difference of approximately 0.3 Vol%. The gas chromatographic method is almost 1…

Diagnostic validity of ICDAS II, VistaProof and a combination of these two methods. An in vitro study in pre-cavitated lesions

2017

Purpose In view of the present fall in advanced cavitation lesion prevalence, diagnostic methods have been developed to assist in assessing and measuring pre-cavitation lesions. The purpose of this study was to assess the VistaProof fluorescence-based system in vitro and compare the results with those of visual examination using the ICDAS II criteria. Methods 100 permanent teeth were collected and 65 were chosen at random for this study. Two separate examiners each examined them twice, 3 weeks apart, assessing them in accordance with ICDAS II. They were subsequently examined with the VistaProof system and the images were stored in the computer program. After obtaining all these data, the te…

Rapid and Standardized Quantitation of Hemolytic Activity of the Fourth Component of Human Complement

1990

Based on a method that uses the fourth component of complement (C4)-deficient guinea pig serum to quantify the hemolytic activity of C4, we developed an assay that allows the processing of a large number of individual samples with high reproducibility. In contrast to the conventional procedure using titration curves of each sample to be determined, we can show that a single appropriate dilution of the sample allows accurate quantitation of hemolytic activity. The reliability of the procedure is demonstrated using either C4A- or C4B- deficient and normal individual samples.

On-line extraction coupled to liquid chromatographic analysis of hydrophobic organic compounds from complex solid samples-Application to the analysis…

2019

This work investigates the applicability of on-line extraction (OLE) directly coupled to liquid chromatography (LC) for the dynamic extraction of hydrophobic organic compounds from complex solid samples. The method operates within the existing apparatus of the LC by replacing the valve loop with an extraction vessel comprised of an empty guard column loaded with the sample. In this manner, extraction is accomplished by the mobile phase as it flows through the extraction vessel under high pressure without the need for additional apparatus other than those comprising the LC system or additional sample pretreatment steps. The experimental parameters affecting the extraction efficiency of the m…

Two optimizing procedures for the solution of complex systems of equations: a powerful tool for modelling and simulation of metabolism

2000

Introduction Standard calculations for the evaluation of indirect calorimetry (IC) are based on two-dimensional nonlinear systems of equations. For a more sophisticated evaluation metabolic models can be used, which are described by complex systems of equations. Since the solutions are multidimensional, a concrete result must be selected by means of constraints, using optimizing procedures. These multidimensional optimizations are critical concerning processing time and reproducibility of minimum detection. Methods In order to simulate the status of metabolism of ICU patients on the basis of IC data, a complex model of metabolism was developed. The model was described by a system of equatio…

2021

(1) Background: The purpose of this study was to evaluate the day-to-day variability and year-to-year reproducibility of an accelerometer-based algorithm for sit-to-stand (STS) transitions in a free-living environment among community-dwelling older adults. (2) Methods: Free-living thigh-worn accelerometry was recorded for three to seven days in 86 (women n = 55) community-dwelling older adults, on two occasions separated by one year, to evaluate the long-term consistency of free-living behavior. (3) Results: Year-to-year intraclass correlation coefficients (ICC) for the number of STS transitions were 0.79 (95% confidence interval, 0.70–0.86, p < 0.001), for mean angular velocity—0.81 (95…

A simple method for measurement of mechanical power in jumping.

1983

A simple test for the measurement of mechanical power during a vertical rebound jump series has been devised. The test consists of measuring the flight time with a digital timer (+/- 0.001 s) and counting the number of jumps performed during a certain period of time (e.g., 15-60 s). Formulae for calculation of mechanical power from the measured parameters were derived. The relationship between this mechanical power and a modification of the Wingate test (r = 0.87, n = 12 males) and 60 m dash (r = 0.84, n = 12 males) were very close. The mechanical power in a 60 s jumping test demonstrated higher values (20 W X kgBW-1) than the power in a modified (60 s) Wingate test (7 W X kgBW-1) and a Mar…

NMR relaxation times of trabecular bone—reproducibility, relationships to tissue structure and effects of sample freezing

2010

Nuclear magnetic resonance (NMR) spectroscopy provides a potential tool for non-invasive evaluation of the trabecular bone structure. The objective of this study was to determine the reproducibility of the NMR relaxation parameters (T(2), Carr-Purcel-T(2), T(1ρ)) for fat and water and relate those to the structural parameters obtained by micro-computed tomography (μCT). Especially, we aimed to evaluate the effect of freezing on the relaxation parameters. For storing bone samples, freezing is the standard procedure during which the biochemical and cellular organization of the bone marrow may be affected. Bovine trabecular bone samples were stored at -20 °C for 7 days and measured by NMR spec…

126. Dosimetric analysis of phenolic solid state pellets exposed to radio-therapeutic photon and electron beams through electron spin resonance techn…

2018

Abstract Purpose Among the various dosimetric techniques used for characterizing the radiation beams used in radiation therapy, the electron spin resonance (ESR) arouses increasing interest for applications in various therapy procedures. In this work we report the ESR investigation of particular phenol compounds exposed to clinical photon and electron beams [1] . Materials and methods Pellets were produced by mixing Phenol (IRGANOX 1076® Sigma Aldrich) and paraffin (10% by weight). The irradiations of dosimeters were performed with photon and electron beams with absorbed doses ranging from 0 to 13 Gy. Basic dosimetric properties of phenolic dosimeters, such as reproducibility, dose-response…

Lead acetate precursor based p-i-n perovskite solar cells with enhanced reproducibility and low hysteresis

2015

A low temperature approach for the fabrication of p-i-n perovskite solar cells is presented. Using lead acetate-based precursors, flat and homogeneous CH3NH3PbI3 films, compatible with the use of thin organic charge transport layers, can be obtained. The corresponding solar cells showed power conversion efficiency up to 12.5%, with remarkable reproducibility and very low hysteresis.