Search results for "Oran"
showing 10 items of 2425 documents
Multivariate statistical analysis of a large odorants database aimed at revealing similarities and links between odorants and odors
2017
International audience; The perception of odor is an important component of smell; the first step of odor detection, and the discrimination of structurally diverse odorants depends on their interactions with olfactory receptors (ORs). Indeed, the perception of an odor's quality results from a combinatorial coding, in which the deciphering remains a major challenge. Several studies have successfully established links between odors and odorants by categorizing and classifying data. Hence, the categorization of odors appears to be a promising way to manage odors. In the proposed study, we performed a computational analysis using odor descriptions of the odorants present in Flavor-Base 9th Edit…
Odorant Metabolism Analysis by an Automated Ex Vivo Headspace Gas-Chromatography Method
2015
International audience; In the olfactory epithelium (OE), odorant metabolizing enzymes have the dual function of volatile component detoxification and active clearance of odorants from the perireceptor environment to respectively maintain the integrity of the tissues and the sensitivity of the detection. Although emphasized by recent studies, this enzymatic mechanism is poorly documented in mammals. Thus, olfactory metabolism has been characterized mainly in vitro and for a limited number of odorants. The automated ex vivo headspace gas-chromatography method that was developed here was validated to account for odorant olfactory metabolism. This method easily permits the measurement of the f…
Chemical Profiles of Integumentary and Glandular Substrates in Australian Sea Lion Pups ( Neophoca cinerea )
2019
International audience; Recognition of individuals or classes of individuals plays an important role in the communication systems of many mammals. The ability of otariid (i.e., fur seal and sea lion) females to locate and identify their offspring in colonies after returning from regular foraging trips is essential to successful pup rearing. It has been shown that olfaction is used to confirm the identity of the pup by the mother when they reunite, yet the processes by which this chemical recognition occurs remain unclear. Using gas chromatography-mass spectrometry, we examined chemical profiles of integumentary and glandular secretions/excretions from pre- and post-molt Australian sea lion …
S2k guidelines for the use of topical preparations on the skin
2018
The present guidelines are aimed at dermatology residents and board-certified dermatologists as well as policymakers and insurance companies. Developed by dermatologists in collaboration with pharmacists using a formal consensus process (S2k), they include general aspects with respect to pharmacokinetics and regulatory terminology. Recommendations are provided on the various indications for extemporaneous preparations and their quality assurance. The importance of pharmaceutical vehicles and problems associated with substituting one vehicle for another are discussed. The guidelines include criteria for choosing a suitable pharmaceutical vehicle and for specific aspects in terms of treatment…
Stability of OBPs
2020
Odorant binding proteins (OBPs) are small proteins, some of which bind odorants with high specificity. OBPs are relatively easy to produce and show a pronounced stability toward thermal and chemical denaturation. This high stability renders OBPs attractive candidates for the development of odorant detections systems. Unfortunately, binding of odorants is not easy to quantify due to lack of spectroscopic signals upon binding. Therefore, a possible approach to detect binding is to employ the shift in thermal or chemical stability upon ligand-protein interaction. Being a rather indirect approach, the experimental setup should be done with care. Here, the experimental results on stability of OB…
Isolation and characterisation of new Gram-negative and Gram-positive atrazine degrading bacteria from different French soils
2001
The capacity of 12 soils to degrade atrazine was studied in laboratory incubations using radiolabelled atrazine. Eight soils showed enhanced degradation of this compound. Twenty-five bacterial strains able to degrade atrazine were isolated by an enrichment method from 10 of these soils. These soils were chosen for their wide range of physico-chemical characteristics. Their history of treatment with atrazine was also variable. The genetic diversity of atrazine degraders was determined by amplified ribosomal restriction analysis (ARDRA) of the 16S rDNA gene with three restriction endonucleases. The 25 bacterial strains were grouped into five ARDRA types. By sequencing and aligning the 16S rDN…
On the consistency of liking scores : insights from a study including 917 consumers from 10 to 80 years old
2004
Preference for 7 orange juices was recorded monadically. Three of the samples were replicates of the same juice (RJ). The 4 other samples were RJ slightly spiked with either sucrose, or citric acid, or quinine or an orange flavor. Each subject then performed a paired preference test composed of RJ and the modified juice whose score was the furthest from the RJ score. Finally, subjects were asked to choose one among 8 reasons why they preferred that sample. A number of individual statistics were computed in order to compare the consistency of liking scores within session, across ages and between genders. Women were slightly more consistent than men. However, no significant effect of age nor …
Third International Congress of Histochemistry and Cytochemistry
1968
The tissue distribution of enzymatic activities in intestinal metaplasia stomachs exhibiting chronic gastritis was compared histochemically with that of the small intestine in man.
Interaction between odorants and proteins involved in the perception of smell: the case of odorant-binding proteins probed by molecular modelling and…
2012
A joint approach that combines molecular modelling and fluorescence spectroscopy is used to study the affinity of an odorant binding protein towards various odorant molecules. We focus on the capability of molecular modelling to rank odorants according to their affinity with this protein, which is involved in the sense of smell. Although ligand-based approaches are unable to propose an accurate model attending to the strength of the bond with the odorant-binding protein, receptor-based structures considering either static or dynamic structure of the protein perform equally to discriminate between good, medium and low affinity odorants. Such approaches will be useful for further rational des…
Salt and Aroma Compound Distributions Influence Flavour Release and Temporal Perception While Eating Hot-Served Flans.
2021
International audience; To counteract the negative effect of salt overconsumption on health, strategies have been developed to reduce the salt content in food products. Among them, two promising strategies based on odour-induced saltiness enhancement and the heterogeneous distribution of flavour compounds were combined and assessed in four-layer cream-based snacks. To investigate the relationship between saltiness enhancement, temporal release and perception of flavour compounds in hot snacks with heterogeneous distribution of salt and aroma compounds, complementary techniques were used: nose space PTR-Tof-MS (Proton Transfer Reaction-Time of Flight–Mass Spectrometry) to assess the release …