TRPM5-expressing microvillous cells in the main olfactory epithelium

Background  

The main olfactory epithelium (MOE) in the nasal cavity detects a variety of air borne molecules that provide information regarding the presence of food, predators and other relevant social and environmental factors. Within the epithelium are ciliated sensory neurons, supporting cells, basal cells and microvillous cells, each of which is distinct in morphology and function. Arguably, the least understood, are the microvillous cells, a population of cells that are small in number and whose function is not known. We previously found that in a mouse strain in which the TRPM5 promoter drives expression of the green fluorescent protein (GFP), a population of ciliated olfactory sensory neurons (OSNs), as well as a population of cells displaying microvilli-like structures is labeled. Here we examined the morphology and immunocytochemical properties of these microvillous-like cells using immunocytochemical methods.     

Long-range energy transfer and ionization in extended quantum systems driven by ultrashort spatially shaped laser pulses

The processes of ionization and energy transfer in a quantum system composed of two distant H atoms with an initial internuclear separation of 100 atomic units (5.29 nm) have been studied by the numerical solution of the time-dependent Schr?dinger equation beyond the Born-Oppenheimer approximation. Thereby it has been assumed that only one of the two H atoms was excited by temporally and spatially shaped laser pulses at various laser carrier frequencies. The quantum dynamics of the extended H-H system, which was taken to be initially either in an unentangled or an entangled ground state, has been explored within a linear three-dimensional model, including the two z coordinates of the electrons and the internuclear distance R. An efficient energy transfer from the laser-excited H atom (atom A) to the other H atom (atom B) and the ionization of the latter have been found. It has been shown that the physical mechanisms of the energy transfer as well as of the ionization of atom B are the Coulomb attraction of the laser driven electron of atom A by the proton of atom B and a short-range Coulomb repulsion of the two electrons when their wave functions strongly overlap in the domain of atom B.     

Application of the finite element method to time-dependent quantum mechanics: I. H and He in a laser field

A finite element approach is described to solve the time- dependent Hartree-Fock equation of atoms in the presence of time-dependent electromagnetic fields. Time-dependent energy changes, ionization rates and high order nonlinear optical polarizabilities, 2n+1 (n >, 0) for the atoms H and He have been calculated. The finite element method is shown to be easily adaptable to treat intense short pulses and includes automatically both bound and continuum electronic states.     

Efficient and accurate numerical modeling of a micro–macro nonlinear optics model for intense and short laser pulses

In this work we are interested in the fast simulation of ultrashort and intense laser pulses propagating in macroscopic nonlinear media. In this goal, we consider the numerical micro–macro Maxwell–Schrödinger-Plasma model originally presented by Lorin et al. [9], [10]. Although this model is, in theory, applicable to large domains, due to its computational complexity, only short distances of propagation could be considered (less than 1 mm so far, see [9]). In the present paper, we explore some simple, but fast and accurate techniques allowing to reduce the computational complexity by a large factor (up to 60) and then to consider larger domains. This reduction is naturally essential to make this model relevant to study realistic laser–matter interactions at a macroscopic scale. Numerical simulations are proposed to illustrate the chosen approach.     

Asymmetric electron-nuclear dynamics in two-color laser fields: laser phase directional control of photofragments in H+2

Exact non-Born-Oppenheimer numerical solutions of the time-dependent Schrodinger equation for the 1D H+2 molecule in an intense, two-color (omega+2omega) laser field have been obtained. Both electron and proton kinetic energy spectra show spatial, correlated, asymmetric distributions. The calculated spectra exhibit the same unusual correlations as in experiments, in which both positively charged nuclear fragments and negatively charged photoelectrons were preferentially emitted in the same direction. The above asymmetries of photoemission of electrons seen in our quantum simulation are interpreted in the framework of a quasistatic tunneling model.     

Integral transform functions and separable potentials

General forms for asymptotic wave functions are derived from properties of the relevant Green's function. The use of separable potentials constructed from the asymptotic functions is described and the relation with integral transform functions is discussed.     

Muonic molecules in superintense laser fields

We study theoretically the ionization and dissociation of muonic molecular ions (e.g., dd mu) in superintense laser fields. We predict that the bond breaks by tunneling of the lightest ion through a bond-softened barrier at intensity I > or =10(21) W/cm(2). Ionization of the muonic atomic fragment occurs at much higher intensity I > or =6 x 10(22) W/cm(2). Since the field controls the ion trajectory after dissociation, it forces recollision of a approximately 10(5)-10(6) eV ion with the muonic atom. Recollision can trigger a nuclear reaction with sub-laser-cycle precision. In general, molecules can serve as precursors for laser control of nuclear processes.     

Phase dependence of enhanced ionization in asymmetric molecules

We study enhanced ionization (EI) in asymmetric molecules by solving the 3D time-dependent Schr?dinger equation for HeH2+ driven by a few-cycle laser pulse linearly polarized along the molecular axis. We find that EI is much stronger when the laser's carrier-envelope phase is such that the electric field at the peak of the pulse is antiparallel to the permanent dipole of the molecule (PDM). This phase dependence is explained by studying the molecule in the presence of a static electric field. When this field is antiparallel to the PDM, the energy of the dressed ground state moves up (with increasing internuclear distance R) to cross with excited states, leading to a stronger ionization via intermediate state resonances and via tunneling. We predict analytically the laser and molecular parameters at which these crossings are expected to occur in any asymmetric molecule.