Search results for "molécula"
showing 10 items of 109 documents
Development and application of (bio)analytical methodologies in capillary electrophoresis. Enantioselectivity considerations
2014
El desarrollo de nuevos fármacos es un proceso largo, complejo y costoso que incluye la evaluación en diferentes etapas de propiedades farmacocinéticas y farmacodinámicas de la nueva molécula. En las primeras etapas del desarrollo de un fármaco es habitual el uso de métodos in vitro para el cribado de alto rendimiento de las propiedades de nuevas moléculas, con el objetivo de obtener datos preliminares sobre la potencial actividad farmacológica de una molécula y sobre su farmacocinética. Cuando se emplean moléculas quirales, tanto sus propiedades farmacocinéticas como las farmacodinámicas pueden presentar un cierto grado de enantioselectividad debido a la interacción con biomacromoléculas ó…
Contribution à l'étude des liaisons optiques atmosphériques : propagation, disponibilité et fiabilité.
2005
In this work we study the fog attenuation in the visible and infrared spectral band related to Free Space Optics (FSO). Based on the Mie scattering theory, fog extinction coefficients for different particle size distributions as a function of wavelength were derived. A simple analytical model allowing the prediction of atmospheric transmission for the 0.69 - 1.55 µm spectral band was developed. This model is valid for advection and convection fog and for visibility range between 50 to 1000 m. This model, implemented into software developed at FT R&D, allows the prediction of the Quality of Service of FSO links. Finally, we performed an experimental study to compare the fog effect on two FSO…
The 18S ribosomal RNA m 6 A methyltransferase Mettl5 is required for normal walking behavior in Drosophila
2020
RNA modifications have recently emerged as an important layer of gene regulation. N6-methyladenosine (m6A) is the most prominent modification on eukaryotic messenger RNA and has also been found on noncoding RNA, including ribosomal and small nuclear RNA. Recently, several m6A methyltransferases were identified, uncovering the specificity of m6A deposition by structurally distinct enzymes. In order to discover additional m6A enzymes, we performed an RNAi screen to deplete annotated orthologs of human methyltransferase-like proteins (METTLs) in Drosophila cells and identified CG9666, the ortholog of human METTL5. We show that CG9666 is required for specific deposition of m6A on 18S ribosomal …
Role of Electrical Charges on the Adsorption of Hydrogen: Something Old, Something New.
2022
The adsorption of H2 in zeolites by molecular simulations use, in many applications, single sphere model. Although this representation provides coherent results with ex- periments above 77K, below this temperature the usual hydrogen representation fails to reproduce experimental results. The disagreement can be associated to the interplay of the atomistic heterogeneity and the electric field produced by the zeolite faujasite. These aspects are generally excluded in classical force fields. For elucidating the influ- ence of these issues, we performed DFT simulations for the faujasite Na86X at 40K with and without guest hydrogen molecules for determining the electrical field generated by the …
Etude des interactions dans la formation d'agrégats thermiques mixtes entre globulines de pois et béta-lactoglobuline : application à l'élaboration d…
2016
In the context of protein source diversification, pea protein is a promising ingredient and may be associated with milk proteins such as whey proteins in the production of new food products. In the present work, the thermal aggregation (85°C - 1 h) of pea globulins (Glob) alone and in admixture with β-lactoglobulin (βlg), prior to acid gelation, was studied as a function of total protein concentration, βlg/Glob weight ratio and ionic strength. The characterization of soluble aggregates was carried out by combining different analytical methods such as surface hydrophobicity determination, disulfide bridge quantification, dynamic light scattering (DLS), size exclusion chromatography (SEC-HPLC…
Approches protéomiques en archéologie et héritage culturel : caractérisation de protéines anciennes préservées dans des coquilles de mollusques
2021
Archaeological mollusc shell artifacts and ecofacts are valuable sources to study past cultures and provide insights on how people exploited their environments. Mollusc shells were often used as raw materials to make personal ornaments and are abundantly found in archaeological sites. However, minute, heavily worked and/or fragmented shell ornaments are rarely identified at different taxonomic levels, due to limited availability of analytical approaches to determine taxon-specific (diagnostic) features. In recent years, proteomics, which exploits the high sensitivity of modern mass spectrometry techniques, has been successfully applied to the study of a variety of bioarchaeological remains,…
Desarrollo de nuevos sistemas separativos para la determinación de biomoléculas en matrices vegetales
2017
La presente memoria se enmarca dentro de las líneas de investigación del grupo de investigación, entre las que se encuentran: i) el desarrollo de materiales poliméricos con fines separativos, y ii) la puesta a punto de metodologías analíticas rápidas y fiables para el control de calidad en la industria de aceites vegetales y otros productos de interés agroalimentario. En consecuencia, los objetivos principales de esta Tesis Doctoral son: i) el diseño y optimización de soportes poliméricos modificados con nanopartículas metálicas (tales como el oro y la plata) para la extracción de proteínas en matrices vegetales, ii) la preparación y evaluación de sistemas de extracción de proteínas en dich…
Vers le contrôle de l'alignement et de l'orientation : théorie et expérience
2010
This thesis is about the control and characterisation of the alignment and orientation of molecules by ultra short laser pulses on a theoretical and experimental approach. Alignment corresponds to a symmetric angular distribution of the molecular axis peaked along the laser field axis, whereas orientation provides an asymmetric distribution favouring one spatial direction. Orientation by sudden two-colour (2+1) pulses is studied extensively for the non resonant case and conditions required for achieving significant orientation are explored. A second two-colour scheme, where the second harmonic is in quasi resonance with a vibrational level of the molecule, is also presented and discussed. T…
Ecologie moléculaire d'une relation hôte - parasite en contexte insulaire marin. Crabes parasites des oursins spatangues en Mer des Caraïbes
2014
Comparing the population genetic structures of two species documents on the environmental factors and life history traits that shape the dispersal of the individuals. For host-parasite couple, this approach also permits to predict local adaptation of these species. The investigated species in this work are the ectoparasitic crab Dissodactylus primitivus and its sea urchin host Meoma ventricosa, both species being endemic to the Caribbean and neighboring American coasts. Several molecular markers were used, namely microsatellites and cytochrome oxidase I (mitochondrial). Moreover, morphometric analyses (shape) were also done. By studying populations across the Antilles arc and along the Pana…
Contribution to development of microbial bioindicators for assessing the impact of agricultural pratices on soil
2015
Soil is the support of agricultural production. It performs many functions essential to the provision of ecosystem services necessary for the well-being of our societies. Soil physicochemical and biological properties have been altered by the development of intensive agriculture while it is a non-renewable resource, revealing the need to develop new management practices suitable for the sustainability of soil quality. This also marked the entry into the “Agroecology” era, which promotes the development of new agricultural systems optimizing services provided by biodiversity to reduce the use of inputs and energy use. To achieve this aim, the development of a range of indicators to assess th…