Search results for "Laboratory"
showing 10 items of 923 documents
Anti-16-kilodalton mycobacterial protein immunoglobulin M levels in healthy but purified protein derivative-reactive children decrease after chemopro…
2007
ABSTRACT Serum responses against Mycobacterium tuberculosis HSP16 were determined for children with tuberculosis (TB) and for healthy purified protein derivative (PPD)-positive and PPD-negative children. Immunoglobulin G (IgG) and IgM responses were higher for TB patients than for other groups. After chemotherapy, IgM and IgG responses decreased for TB patients and PPD-positive subjects. Monitoring of anti- M. tuberculosis HSP16 responses could assist in the management of pediatric TB.
German-Wide Interlaboratory Study Compares Consistency, Accuracy and Reproducibility of Whole-Genome Short Read Sequencing.
2020
We compared the consistency, accuracy and reproducibility of next-generation short read sequencing between ten laboratories involved in food safety (research institutes, state laboratories, universities and companies) from Germany and Austria. Participants were asked to sequence six DNA samples of three bacterial species (Campylobacter jejuni, Listeria monocytogenes and Salmonella enterica) in duplicate, according to their routine in-house sequencing protocol. Four different types of Illumina sequencing platforms (MiSeq, NextSeq, iSeq, NovaSeq) and one Ion Torrent sequencing instrument (S5) were involved in the study. Sequence quality parameters were determined for all data sets and central…
Serum Copeptin and Midregion Proadrenomedullin (MR-proADM) After an Ultramarathon
2014
Background Although it is widely acknowledged that physical activity confers several health benefits, it remains uncertain whether strenuous and physically demanding exercise might determine biological effects that might turn to be ultimately unfavorable for health. Copeptin and midregion proadrenomedullin (MR-proADM) are emerging cardiovascular and stress biomarkers, but little is known about the influence of strenuous physical exercise on their concentrations. Methods The present study was performed to investigate the variation of copeptin and MRproADM, along with that of serum creatinine and estimated glomerular filtration rate before and after a 60 km ultramarathon in 16 healthy Caucasi…
„Die Photographie als Hülfsmittel mikroskopischer Forschung”? Joseph von Gerlach (1820-1896) und die frühen anatomischen Mikrophotographen
2005
The Erlangen anatomist Joseph von Gerlach was one of the first medical researchers who used microphotography for their scientific aims in basic tissue research. Already in 1863, Gerlach published a famous handbook on the methodology of the microphotographic technique, entitled Die Photographie als Hulfsmittel mikroskopischer Forschung. Here, he discussed the technological, practical and epistemological standards and constraints of the newly introduced visualisation technique of scientific photography. The efforts and setbacks of Gerlachs' innovative approaches shall be characterised in the present paper. Furthermore, some of the most important arguments put forward by some of his peers are …
Identification of microplastics using 4‐dimethylamino‐4′‐nitrostilbene solvatochromic fluorescence
2021
In this work, we introduce the use of 4-dimethylamino-4'-nitrostilbene (DANS) fluorescent dye for applications in the detection and analysis of microplastics, an impendent source of pollution made of synthetic organic polymers with a size varying from less than 5 mm to nanometer scale. The use of this dye revealed itself as a versatile, fast and sensitive tool for readily discriminate microplastics in water environment. The experimental evidences herein presented demonstrate that DANS efficiently absorbs into a variety of polymers constituting microplastics, and its solvatochromic properties lead to a positive shift of the fluorescence emission spectrum according to the polarity of the poly…
Analytical and mineralogical studies of ore and impurities from a chromite mineral using X-ray analysis, electrochemical and microscopy techniques
2007
A wide analytical study of South African chromite ore, material with high interest in ceramic industry, has been carried out. With this purpose, an accurate chemical identification and mineralogical characterization of the mineral and the gangue have been performed using X-ray fluorescence (XRF), voltammetry, X-ray diffraction (XRD), light microscopy (LM), and scanning electron microscopy (SEM/EDX). The elemental composition of the sample (ore and gangue) has been obtained by XRF. The voltammetric analysis has allowed to demonstrate that iron in the sample was as Fe(II). The main compound of the chromite ore was a spinel (magnesiochromite ferroan), identified by XRD from the sample, which c…
Study of two MTA cements
2014
Introduction: To determine and compare the pH, conductivity and calcium release of an experimental Portland cement (PE) consisting of trioxid mineral aggregate and a comercially available modified Portland cement (C.P.M.) after 1, 2, 3, 4, 8, 10, 15 and 30 days. Material and Methods: Cements were mixed following the manufacturer's instructions, with a powder: liquid ratio of 3:1. Each cement was placed in 12 PVC tubes 1 mm in diameter and 10 mm in length and allowed to set. Four empty tubes were used as negative controls. Tubes were submerged in plastic flasks containing 10 ml deionized water and stored at 37ºC and 100% humidity. After 1, 2, 3, 4, 8, 10, 15 and 30 days tubes were removed fr…
Microfungal Alkylation and Volatilization of Selenium Adsorbed by Goethite
2009
Selenium adsorbed in the oxyanionic form by Fe-oxides like goethite is considered of benefit for long-term stabilization of (79)Se under near field conditions of radionuclide waste disposal sites. However, microbe-mediated volatilization of the uranium fission product (79)Se has not yet been considered for risk assessment based on the use of the water-solid distribution coefficient K(D). We have performed incubation experiments in a ternary system selenium-microbe-goethite and show that mycobiota including the common black microfungi genera Alternaria alternata are capable of volatilizing the Se even if immobilized by goethite. The microfungi were incubated in a standardized nutrient broth …
Mitochondrial DNA haplotype frequencies in natural and experimental populations of Drosophila subobscura.
1998
Abstract The evolution of Drosophila subobscura mitochondrial DNA has been studied in experimental populations, founded with flies from a natural population from Esporles (Majorca, Balearic Islands, Spain). This population, like other European ones, is characterized by the presence of two very common (>96%) mitochondrial haplotypes (called I and II) and rare and endemic haplotypes that appear at very low frequencies. There is no statistical evidence of positive Darwinian selection acting on the mitochondrial DNA variants according to Tajima's neutrality test. Two experimental populations, with one replicate each, were established with flies having a heterogeneous nuclear genetic back…
MODELLING THE DISPERSION PROPERTIES OF MASS LINEAR CHAINS: EXPERIMENTS AND SIMULATIONS
2009
We analyze and discuss the results of an experiment with the goal of revealing the phonon-like acoustic dispersion curve. The experimental apparatus consists of a sonometer and an electromagnetic driver connected to a signal generator in order to establish standing waves along a stretched metal string (a guitar string) upon which a set of beads (used normally for fishing) has been fixed. The oscillation amplitude is measured by means of a detector connected to an MBL interface. We detect the resonance frequencies as function of the wave-number and obtain the corresponding dispersion curve. The results show that deviations from linearity occur when the wavelength is comparable with the dista…