Search results for "ToF"
showing 10 items of 841 documents
Multispectral, Fluorescent and Photoplethysmographic Imaging for Remote Skin Assessment
2017
Optical tissue imaging has several advantages over the routine clinical imaging methods, including non-invasiveness (does not change the structure of tissues), remote operation (avoids infection) and ability to quantify the tissue condition by means of specific image parameters. Dermatologists and other skin experts need compact (preferably pocket-size), self-sustained and easy-to-use imaging devices. The operational principles and designs of ten portable in-vivo skin imaging prototypes developed at the Biophotonics Laboratory of Institute of Atomic Physics and Spectroscopy, University of Latvia during the recent five years are presented in this paper. Four groups of imaging devices are con…
Effects of hydrological events on morphological evolution of a fluvial system
2018
Abstract This study quantifies morphological evolution of the Dez River, Iran, from 1955 to 2016. The approach uses a sequence of Landsat images, aerial photos, and topographic maps. In addition, the hydrological data including average daily discharge and yearly maximum discharge at the Dezful hydrological station for the period (1955–2016) were used. The study reach was divided into 48 meander loops from upstream to downstream. Active channel width (w) was determined at 10 m intervals and changes assessed along the study reach of the Dez River. Morphological indices including sinuosity index; straight meander length; centerline flow length; erosion area; erodible length channel migration; …
Estudio de los mecanismos moleculares de estrés oxidativo, disfunción mitocondrial, estrés de retículo endoplasmático y autofagia en leucocitos de pa…
2015
Introducción: La diabetes mellitus tipo 2 (DM2) se presenta como un cuadro clínico que incluye diversas alteraciones en el metabolismo, incluyendo hiperglicemia, resistencia a insulina, dislipidemia e inflamación crónica de bajo grado. Supone un gran problema a nivel mundial dada su creciente incidencia y las complicaciones deletéreas que conlleva, principalmente en el sistema cardiovascular. El principal factor determinante de DM2 es la obesidad. A medida que aumenta el índice de masa corporal se desarrolla resistencia a la insulina lo que finalmente originará una pérdida del control homeostático de la glucosa. Entre las principales complicaciones vasculares de la diabetes están por una pa…
Performance of industrial strains of Saccharomyces cerevisae during wine fermentation is affected by manipulation strategies based on sporulation.
2002
Genetic manipulation of industrial wine yeast strains has become an essential tool for both the study of the molecular mechanisms underlaying their physiology and the improvement of their fermentative properties. The construction of null mutants for any gene in these usually diploid strains, by using a procedure based on sporulation of a heterozygote lacking one copy of the gene of interest, has been tested as an alternative to the tedious work of sequential disruption of the complete set of copies. Our results indicate that most of the homozygotes resulting from sporulation of wine yeast strains are defective in glucose consumption under microvinification conditions in synthetic must and p…
A short-range gradient of histone H3 acetylation and Tup1p redistribution at the promoter of the Saccharomyces cerevisiae SUC2 gene.
2003
Chromatin immunoprecipitation assays are used to map H3 and H4 acetylation over the promoter nucleosomes and the coding region of the Saccharomyces cerevisiae SUC2 gene, under repressed and derepressed conditions, using wild type and mutant strains. In wild type cells, a high level of H3 acetylation at the distal end of the promoter drops sharply toward the proximal nucleosome that covers the TATA box, a gradient that become even steeper on derepression. In contrast, substantial H4 acetylation shows no such gradient and extends into the coding region. Overall levels of both H3 and H4 acetylation rise on derepression. Mutation of GCN5 or SNF2 lead to substantially reduced SUC2 expression; in…
Assessment wine aroma persistence by using an in vivo PTR-ToF-MS approach and its relationship with salivary parameters
2019
To better understand wine aroma persistence, the nasal cavity of nine volunteers was monitored by Proton Transfer Reaction-Time of Flight-Mass Spectrometry (PTR-ToF-MS) after they rinsed their mouths with three rosé wines (one control and the same wine supplemented with two tannin extracts) during four minutes. Wines were aromatised with a mixture of five target aroma compounds. Results showed that wine aroma persistence was highly compound-dependent: while esters disappeared very fast, other compounds such as linalool remained in the oral cavity for longer times after wine expectoration. A low effect of tannins (at 50 mg/L) on nasal cavity parameters was observed, with the exception for th…
In vitro studies of adsorption of milk proteins onto tooth enamel
2006
Abstract The aim of this investigation was to study in vitro adsorption of milk proteins onto tooth enamel. In vitro “milk protein pellicles” were formed on enamel specimens incubated in fluid milk products: skimmed milk (pH 6.7), acidified skimmed milk (pH 4.2), yoghurt and neutralized yoghurt (pH 6.7). The enamel specimens were used as such or pre-incubated in saliva. The “milk pellicles” were desorbed from enamel surfaces, and proteins separated by sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE). Proteins were identified by their pattern of migration in SDS-PAGE or by matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS) fingerp…
Estimating the chance of success of archaeometric analyses of bone: UV-induced bone fluorescence compared to histological screening
2011
Abstract For most archaeometric analyses on archaeological bone material, such as the determination of the isotopic composition or genetic approaches, an advanced degree of diagenetic alteration can make designated analysis impossible. Since the lack of a positive signal is mostly seen only after time consuming and cost intensive sample processing, the need for an easy-to-apply screening method that allows a pre-selection of samples containing well-preserved biomolecules is obvious. In this study, we visually determined the UV-induced autofluorescence of 76 horse bone cross-sections, all from prehistoric archaeological sites of varying environmental and chronological background. In order to…
An Efficient Traceable Attribute-Based Authentication Scheme with One-Time Attribute Trees
2015
Attribute-based authentication (ABA) is a way to authenticate signers by means of attributes and it requests proof of possessing required attributes from the one to be authenticated. To achieve the property of traceability, required attributes should be combined with the signer’s attribute private keys in order to generate a signature. In some schemes, signers’ attribute keys are related to attribute trees, so changing attribute trees will cause the regeneration of all related attribute keys. In this paper, we propose an efficient traceable ABA scheme, where the generation of signers’ attribute keys is independent from attribute trees. Thus the same set of attribute keys can be used with a …
An Anonymous Delegatable Attribute-based Credential Scheme for a Collaborative E-health Environment
2019
We propose an efficient anonymous, attribute-based credential scheme capable of provisioning multi-level credential delegations. It is integrated with a mechanism to revoke the anonymity of credentials for resolving access disputes and making users accountable for their actions. The proposed scheme has a lower end-user computational complexity in comparison to existing credential schemes with delegatability and has a comparable level of performance with the credential standards of U-Prove and Idemix. Furthermore, we demonstrate how the proposed scheme can be applied to a collaborative e-health environment to provide its users with the necessary anonymous access with delegation capabilities.