Search results for "composition"

Understanding the release and metabolism of aroma compounds using micro-volume saliva samples by ex vivo approaches

2018

International audience; This study investigated the behaviour of key aroma compounds in the presence of human saliva (200 mu L) from different individuals (n = 3) submitted or not to centrifugation (whole vs clarified saliva). HS-GC results showed that human saliva strongly decreased the release of carbonyl compounds (aldehydes and ketones). This effect was dependent on i) the structure of the aroma compounds and ii) the saliva composition. Whole saliva exerted a higher effect than clarified saliva on aroma compounds. Moreover, this effect was individual-dependent and related to the total protein content and the total antioxidant capacity of saliva. HS-SPME and LLE-GC/MS analyses revealed t…

Role of saliva in oral food perception

2014

Saliva is the first fluid that comes into contact with food during oral processing. Because saliva is the medium that bathes the taste receptors, is the fluid through which taste and aroma compounds are released into the oral cavity and is mixed continuously with food during bolus formation, it is an essential actor in oral chemosensory perception. The complexity of saliva composition, with compounds originating from different salivary glands, from gingival crevicular fluid, from micro-organisms and from food debris, together with its variable nature increases the possibilities for interactions with food compounds and for different roles in perception. These factors are increasingly being t…

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…

Appendicular Muscle Mass, Thigh Intermuscular Fat Infiltration, and Risk of Fall in Postmenopausal Osteoporotic Elder Women

2020

<b><i>Background:</i></b> The association between the quantity and composition of skeletal muscle and the decline in physical function in elderly is poorly understood. Therefore, the primary aim of this cross-over study was to investigate the association between thigh intermuscular adipose tissue (IMAT) infiltration, appendicular muscle mass, and risk of fall in postmenopausal osteoporotic elder women. Second, we examined the differences in muscle mass, IMAT, and risk of fall in the same sample of older subjects after being classified as sarcopenic or nonsarcopenic on the basis of the dual-energy X-ray absorptiometry (DXA)-based Appendicular Skeletal Muscle Mass Inde…

Scalable Dense Factorizations for Heterogeneous Computational Clusters

2008

This paper discusses the design and the implementation of the LU factorization routines included in the Heterogeneous ScaLAPACK library, which is built on top of ScaLAPACK. These routines are used in the factorization and solution of a dense system of linear equations. They are implemented using optimized PBLAS, BLACS and BLAS libraries for heterogeneous computational clusters. We present the details of the implementation as well as performance results on a heterogeneous computing cluster.

SVG Rendering by Watershed Decomposition

2005

XRMA analysis and X-ray diffraction analysis of dental enamel from human permanent teeth exposed to hydrogen peroxide of varying pH

2019

Background This in vitroinvestigation shows how 3.3% H2O2, at different pH-values affects the enamel. Material and Methods A number of fifteen human premolars were used. The enamel of the coronal half in six of the teeth, were exposed by H2O2. Nine teeth were prepared to enamel powder. The enamel was exposed to 3.3% H2O2, at six different pH-values (pH range 4.5 - 7.0). Analyses of the topography of enamel performed by scanning electron microscope (SEM) and the chemical composition of enamel by X-ray microanalysis (XRMA). X-ray powder diffraction (XRD) analysed the crystallinity in enamel powder. Results The exposure to H2O2 at pH5.5 resulted in a decrease of O in the exposed enamel, and ch…

A new approach to the crystal growth of Hg1−xMnxTe by the cold travelling heater method (CTHM)

2001

Abstract In order to obtain crystals with a homogeneous composition and to reduce the Hg high pressure related to the temperature synthesis reaction between the components in elemental form, Hg 1− x Mn x Te bulk crystals were produced by the cold travelling heater method (CTHM). Following the technique initially proposed for the growth of CdHgTe by the Triboulet group, the feed material was a split ingot of two segments, one of HgTe and the other of MnTe, with cross-sectional areas chosen to establish the desired final composition. The growth was carried out at a temperature of 600°C and a rate of 2 mm/h. The Hg 1− x Mn x Te crystals have been characterised by scanning electron microscopy, …

Rod-like ferrites obtained through thermal degradation of a molecular ferrimagnet

2010

This paper presents the characteristics of iron oxides obtained through thermal degradation of a molecular ferrimagnet, {N(n-C4H9)4[Fe II

Ethylene homo- and copolymerization catalyzed by vanadium, zirconium, and titanium complexes having potentially tridentate Schiff base ligands

2021

Abstract New potentially tridentate Schiff base ligands, 2-[({4-[(3-N,N-dimethylamino)propyl] phenyl}imino)methyl]-4,6-di-tert-butylphenol (L1H) and 2-[{2-(N-phenyl-N-methylaminomethyl)-phenylimino}-methyl]-4,6-di-tert-butylophenol (L2H) were prepared and after deprotonation they were reacted with VOCl3 or MCl4 (where M = Zr or Ti) to produce corresponding complexes (L1-V, L2-V, L1-Zr, L2-Ti) with good yields. All new compounds were characterized by the 1H and 13C NMR as well as FTIR spectroscopic methods. Upon activation with Et2AlCl or EtAlCl2, both the vanadium complexes exhibited exceptionally high catalytic activities in the ethylene polymerization (up to 69,000 kg/(molV⋅h) for L1-V an…