Search results for "Molecules"
showing 10 items of 1147 documents
The use of quantum dots in organic chemistry
2009
Abstract We discuss the main mechanisms of interaction between quantum dots (QDs) of different types and organic molecules within the framework of the use of photo-physical properties of colloidal semiconductor nanoparticles for sensing organic and biochemical compounds. We reviewed the recent literature in the field to provide a picture of the state of the art of our knowledge and perspectives on this challenging field. Bearing in mind analysis in organic chemistry based on luminescence and electrochemical changes, we discuss surface interaction based on the use of QDs capped with thiol, cystein, citrate, surfactant, purine and nitroxides, and we explain ligand-analyte, bioconjugate-analyt…
Collective Effects of Organic Molecules based on Holstein-Tavis-Cummings Model
2021
We study the collective effects of an ensemble of organic molecules confined in an optical cavity based on Holstein-Tavis-Cummings model. By using the quantum Langevin approach and adiabatically eliminating the degree of freedom of the vibrational motion, we analytically obtain the expression of the cavity transmission spectrum to analyze the features of polaritonic states. As an application, we show that the dependence for the frequency shift of the lower polaritonic state on the number of molecules can be used in the detection of the ultra-cold molecules. We also numerically analyze the fluorescence spectrum. The variation of the spectral profile with various numbers of molecules gives si…
Dynamic effects in nonlinear magneto-optics of atoms and molecules: review
2004
A brief review is given of topics relating to dynamical processes arising in nonlinear interactions between light and resonant systems (atoms or molecules) in the presence of a magnetic field.
Light flavor and heavy quark spin symmetry in heavy meson molecules
2012
We propose an effective field theory incorporating light SU(3)-flavor and heavy quark spin symmetry to describe charmed meson-antimeson bound states. At lowest order the effective field theory entails a remarkable simplification: it only involves contact range interactions among the heavy meson and antimeson fields. We show that the isospin violating decays of the X(3872) can be used to constrain the interaction between the D and a (D) over bar* mesons in the isovector channel. As a consequence, we can rule out the existence of an isovector partner of the X(3872). If we additionally assume that the X(3915) and Y(4140) are D*(D) over bar* and D*(s)(D) over bar*(s) molecular states, we can de…
Hall–Post inequalities: Review and application to molecules and tetraquarks
2019
A review is presented of the Hall–Post inequalities that give lower-bounds to the ground-state energy of quantum systems in terms of energies of smaller systems. New applications are given for systems experiencing both a static source and inner interactions, as well as for hydrogen-like molecules and for tetraquarks in some quark models. In the latter case, the Hall–Post inequalities constrain the possibility of deeply-bound exotic mesons below the threshold for dissociation into two quark–antiquark mesons. We also emphasize the usefulness of the Hall–Post bounds in terms of 3-body energies when some 2-body subsystems are ill defined or do not support any bound state.
Effects of conjugated linoleic acid isomers toward lipids metabolizing enzymes in male wistar rats
2000
International audience
Caractérisation des enzymes du métabolisme des xénobiotiques olfactives chez le rat : régulation et rôle dans la détection périphérique des molécules…
2010
Diplôme : Dr. d'Université; Les enzymes du métabolisme des xénobiotiques (EMX) jouent un rôle central dans la biotransformation et l’élimination de composés étrangers à l’organisme. Organisées en réseau de biotransformation, ces enzymes catalysent des réactions variées (oxydations, conjugaisons …) afin de rendre ces composés plus hydrophiles. Les EMX sont fortement exprimées dans l’épithélium olfactif de mammifères et des études in vitro ont montré qu’elles possèdent des activités élevées. Outre un rôle dans le métabolisme de molécules toxiques, ces enzymes pourraient être impliquées dans la modulation périphérique de l'olfaction. Les EMX pourraient contribuer à maintenir la sensibilité du…
A combined molecular dynamics and Monte Carlo study of the approach towards phase separation in colloid-polymer mixtures.
2011
A coarse-grained model for colloid-polymer mixtures is investigated where both colloids and polymer coils are represented as point-like particles interacting with spherically symmetric effective potentials. Colloid-colloid and colloid-polymer interactions are described by Weeks-Chandler-Andersen potentials, while the polymer-polymer interaction is very soft, of strength k(B)T/2 for maximum polymer-polymer overlap. This model can be efficiently simulated both by Monte Carlo and molecular dynamics methods, and its phase diagram closely resembles that of the well-known Asakura-Oosawa model. The static and dynamic properties of the model are presented for systems at critical colloid density, va…
Intermolecular potential and rovibrational states of the H2O–D2 complex
2012
International audience; A five-dimensional intermolecular potential for H2O-D-2 was obtained from the full nine-dimensional ab initio potential surface of Valiron et al. [P. Valiron, M. Wernli, A. Faure, L. Wiesenfeld, C. Rist, S. Kedzuch, J. Noga, J. Chem. Phys. 129 (2008) 134306] by averaging over the ground state vibrational wave functions of H2O and D-2. On this five-dimensional potential with a well depth D-e of 232.12 cm (1) we calculated the bound rovibrational levels of H2O-D-2 for total angular momentum J = 0-3. The method used to compute the rovibrational levels is similar to a scattering approach-it involves a basis of coupled free rotor wave functions for the hindered internal r…
Low energy electrons and swift ion track structure in PADC
2015
The current work aims at providing an accurate description of the ion track-structure in poly-allyl dyglycol carbonate (PADC) by using an up-to-date Monte-Carlo code-called TILDA-V (a French acronym for Transport d'Ions Lourds Dans l'Aqua & Vivo). In this simulation the ion track-structure in PADC is mainly described in terms of ejected electrons with a particular attention done to the Low Energy Electrons (LEEs). After a brief reminder of the most important channels through which LEEs are prone to break a chemical bond, we will report on the simulated energetic distributions of LEEs along an ion track in PADC for particular incident energies located on both sides of the Bragg-peak position…