Search results for "Fluids"
showing 10 items of 1936 documents
Retention effect of human saliva on aroma release and respective contribution of salivary mucin and alpha-amylase
2014
International audience; As great differences were observed in the amount of alpha-amylase in human saliva, there is a need to better understand the effect of this protein alone or in mixture with mucin on aroma compound partitioning. We report. the respective role of mucin and alpha-amylase on the air/liquid partition coefficients of two series of 5 methylketones and 5 ethyl-esters. We confirm that mucin affects the release of aroma compounds and, for the first time, we demonstrate the ability of alpha-amylase to decrease the release of aroma compounds. For both proteins, we report the involvement of hydrophobic effects. Interestingly, no cumulative effect was observed when both proteins we…
SALMO and S3M: A Saliva Model and a Single Saliva Salt Model for Equilibrium Studies.
2014
A model of synthetic saliva (SALMO, SALiva MOdel) is proposed for its use as standard medium inin vitroequilibrium and speciation studies of real saliva. The concentrations come out from the literature analysis of the composition of both real saliva and synthetic saliva. The chief interactions of main inorganic components of saliva, as well as urea and amino acids, are taken into account on the basis of a complex formation model, which also considers the dependence of the stability constants of these species on ionic strength and temperature. These last features allow the modelling of the speciation of saliva in different physiological conditions deriving from processes like dilution, pH, a…
Conjunctival Sac Fluid Contains Elevated Levels of Soluble TRAIL: Implications for the Anti-Tumoral Surveillance of the Anterior Surface of the Eye
2008
Little is known on the ability of different epithelia to release soluble TNF-related apoptosis-inducing ligand (TRAIL) and the relevance of TRAIL secretion by epithelial cells is still incompletely understood. On these bases, we have measured the concentration of soluble TRAIL by ELISA in the conjunctival sac fluid. It was the highest ever detected in a biological fluid (mean value of 26,800 pg/ml), being approximately 20-fold greater than that found in human saliva and >200-fold greater than that detected in human serum. On the other hand, osteoprotegerin, the soluble decoy receptor of TRAIL, was almost undetectable in the conjunctival sac fluid. Of note, the levels of soluble TRAIL measur…
Salivary levels of IgE and ECP in patients with recurrent aphthous stomatitis
2019
Background Recurrent aphthous stomatitis is a common oral mucosa disease, with no specific etiology. Atopy has been implicated in the development of this disease. In this study, the salivary levels of immunoglobulin E (IgE) and eosinophil cationic protein (ECP) were measured as allergy-related biomarkers in patients with aphthous stomatitis. Material and Methods In this case-control study, non-stimulated saliva was collected from 85 participants and IgE and ECP were measured. Data were analyzed in SPSS 20 through the Mann-Whitney test, and p<0.05 was considered significant. Results The salivary levels of IgE and ECP were 1.11±0.65 Iu/ml and 26.93±6.95 ng/ml in the case group and 0.73±0/39 I…
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…
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…
Nonequilibrium thermodynamics of the RNA-RNA interaction underlying a genetic transposition program
2021
Thermodynamic descriptions are powerful tools to formally study complex gene expression programs evolved in living cells on the basis of macromolecular interactions. While transcriptional regulations are often modeled in the equilibrium, other interactions that occur in the cell follow a more complex pattern. Here, we adopt a nonequilibrium thermodynamic scheme to explain the RNA-RNA interaction underlying IS10 transposition. We determine the energy landscape associated with such an interaction at the base-pair resolution, and we present an original scaling law for expression prediction that depends on different free energies characterizing that landscape. Then, we show that massive experim…
Simple scheme for extracting work with a single bath
2019
We propose a simple protocol exploiting the thermalization of a storage bipartite system S to extract work from a resource system R. The protocol is based on a recent work definition involving only a single bath. A general description of the protocol is provided without specifying the characteristics of S. We quantify both the extracted work and the ideal efficiency of the process, also giving maximum bounds for them. Then, we apply the protocol to two cases: two interacting qubits and the Rabi model. In both cases, for very strong couplings, an extraction of work comparable with the bare energies of the subsystems of S is obtained and its peak is reached for finite values of the bath tempe…
Tunable Polarons in Bose-Einstein Condensates
2017
A toolbox for the quantum simulation of polarons in ultracold atoms is presented. Motivated by the impressive experimental advances in the area of ultracold atomic mixtures, we theoretically study the problem of ultracold atomic impurities immersed in a Bose-Einstein condensate mixture (BEC). The coupling between impurity and BEC gives rise to the formation of polarons whose mutual interaction can be effectively tuned using an external laser driving a quasi-resonant Raman transition between the BEC components. Our scheme allows one to change the effective interactions between polarons in different sites from attractive to zero. This is achieved by simply changing the intensity and the frequ…
Isotope dependence of the Zeeman effect in lithium-like calcium
2016
The magnetic moment μ of a bound electron, generally expressed by the g-factor μ=−g μB s ħ−1 with μB the Bohr magneton and s the electron's spin, can be calculated by bound-state quantum electrodynamics (BS-QED) to very high precision. The recent ultra-precise experiment on hydrogen-like silicon determined this value to eleven significant digits, and thus allowed to rigorously probe the validity of BS-QED. Yet, the investigation of one of the most interesting contribution to the g-factor, the relativistic interaction between electron and nucleus, is limited by our knowledge of BS-QED effects. By comparing the g-factors of two isotopes, it is possible to cancel most of these contributions an…