Dental health in patients infected by human immunodeficiency virus (HIV). A study of 94 cases

The dental health of 94 HIV-positive patients was investigated by the sum of carious, missing and filling teeth (DMF index), plaque (Silness and Löe) and bleeding point indices (Lenox and Kopczyk). Blood parameters were evaluated, including total lymphocytes, CD4+ lymphocytes, beta-2-microglobulin, platelets, the Quick index, and immunoglobulins (IgG, IgM and IgA). Patient oral parameters were contrasted with risk group (intravenous drug users, homo- and heterosexuals) and controls. An evaluation was also made of differences in dental condition as a function of CD4+ cell number, according to the latest CDC classification (1992). HIV-positive intravenous drug users were found to present poorer DMF, plaque and bleeding point indices than the rest of the patients. No relationship was observed between CD4+ cell numbers in blood and dental condition, thus suggesting that the deteriorated dental health observed is a consequence of factors inherent to the risk groups involved rather than of the altered blood parameters.Une étude portant sur l’état de santé dentaire chez 94 patients VIH positifs a été réalisée, en évaluant l’index des dents cariées, manquantes ou plombées (DMF), l’index de plaque (Silness et Loe) et celui de points de saignement (Lenox et Kopczyk). Une évaluation de divers paramètres sanguins a été faite: le total des lymphocytes, les CD4 +, la beta 2 microglobuline, la numération plaquettaire, le temps de Quick et les immunoglobulines (IgG, IgM et IgA). Les différents paramètres oraux ont été comparés entre les patients appartenant à un groupe à risque (utilisateurs de drogues par voie veineuse, homo et hétérosexuels) et les patients d’un groupe de référence. Les différences dans l’état dentaire en fonction du nombre de cellules CD4 + , en accord avec la dernière classification de la CDC (1992), ont aussi été évaluées. Les patients VIH positifs utilisateurs de drogues par voie veineuse avaient un DMF, un index de plaque et de points de saignement plus faibles que ceux des autres patients. Aucune relation n’a été observée entre le nombre de cellules CD4+ présentes dans le sérum sanguin et l’état dentaire, ce qui suggère que la détérioration de l’état dentaire observée serait la conséquence de facteurs inhérents à chaque groupe à risque plutôt que d’une altération des paramètres sanguins

Purification of plasma membrane vesicles from Vitis vinifera cv. Gamay suspension cells by free electrophoresis

Research Not

The Turbulent Structure of the Arctic Summer Boundary Layer During The Arctic Summer Cloud‐Ocean Study

The mostly ice covered Arctic Ocean is dominated by low‐level liquid‐ or mixed‐phase clouds. Turbulence within stratocumulus is primarily driven by cloud top cooling that induces convective instability. Using a suite of in situ and remote sensing instruments we characterize turbulent mixing in Arctic stratocumulus, and for the first time we estimate profiles of the gradient Richardson number at relatively high resolution in both time (10 min) and altitude (10 m). It is found that the mixing occurs both within the cloud, as expected, and by wind shear instability near the surface. About 75% of the time these two layers are separated by a stably stratified inversion at 100–200 m altitude. Exceptions are associated with low cloud bases that allow the cloud‐driven turbulence to reach the surface. The results imply that turbulent coupling between the surface and the cloud is sporadic or intermittent

Growth of GaInTlAs layers on InP by molecular beam epitaxy

International audienceGrowth of GaInTlAs alloys on InP001 has been attempted by solid source molecular beam epitaxy. Thallium incorporation into Ga 1x In x As matrices was studied as a function of substrate temperature, arsenic overpressure, matrix composition, and growth rate. At high temperatures 350 °C thallium evaporates, whereas at intermediary temperatures 270-350 °C thallium segregates into droplets on the surface. Only in the low temperature range 180-260 °C can thallium be incorporated in some conditions, leading to mirror-like surfaces. Up to 18% Tl content was incorporated into a Ga 0.70 In 0.30 As matrix and up to 40% Tl into a GaAs matrix. For these high Tl concentrations, Tl droplets are avoided and Tl incorporation is achieved only when using high arsenic pressures. However, this limits surface adatom diffusion and leads to amorphous, polycrystalline, or twinned materials. Finally, a narrow window for single-crystal growth has been found for low Tl contents 4% using optimized growth conditions with low V/III pressure ratios and high growth rates

Studying the Boundary Layer Late Afternoon nd Sunset Turbulence (BLLAST)

At the end of the afternoon, when the surface heat fluxes start to sharply decrease, the CBL turns from a convective well-mixed layer to an intermittently turbulent residual layer overlying a stably-stratified boundary layer. This transition raises several observational and modeling issues. Even the definition of the boundary layer during this period is fuzzy, since there is no consensus on what criteria to use and no simple scaling laws to apply. Yet it plays an important role in such diverse atmospheric phenomena as transport and diffusion of trace constituents or wind energy production. This phase of the diurnal cycle remains largely unexplored, partly due to the difficulty of measuring weak and intermittent turbulence, anisotropy, horizontal heterogeneity, and rapid time changes. The Boundary Layer Late Afternoon and Sunset Turbulence (BLLAST) project is gathering about thirty research scientists from the European Union and the United States to work on this issue. A field campaign (BLLAST-FE) is planned for spring or summer 2011 in Europe. BLLAST will utilize these observations, as well as previous datasets, large-eddy and direct numerical simulations, and mesoscale modeling to better understand the processes, suggest new parameterizations, and evaluate forecast models during this transitional period. We will present the issues raised by the late afternoon transition and our strategy to study it.Peer ReviewedPostprint (published version

Studying the Boundary Layer Late Afternoon and Sunset Turbulence (BLLAST)

At the end of the afternoon, when the surface heat fluxes start to sharply decrease, the CBL turns from a convective well-mixed layer to an intermittently turbulent residual layer overlying a stably-stratified boundary layer. This transition raises several observational and modelling issues. Even the definition of the boundary layer during this period is fuzzy, since there is no consensus on what criteria to use and no simple scaling laws to apply. Yet it plays an important role in such diverse atmospheric phenomena as transport and diffusion of trace constituents or wind energy production. This phase of the diurnal cycle remains largely unexplored, partly due to the difficulty of measuring weak and intermittent turbulence, anisotropy, horizontal heterogeneity, and rapid time changes. The Boundary Layer Late Afternoon and Sunset Turbulence (BLLAST) project is gathering about thirty research scientists from the European Union and the United States to work on this issue. A field campaign (BLLAST-FE) is planned for spring or summer 2011 in Europe. BLLAST will utilize these observations, as well as previous datasets, large-eddy and direct numerical simulations, and mesoscale modelling to better understand the processes, suggest new parameterisations, and evaluate forecast models during this transitional period. We will present the issues raised by the late afternoon transition and our strategy to study it.Peer ReviewedPostprint (published version

Recrystallization of amorphous nano-tracks and uniform layers generated by swift-ion-beam irradiation in lithium niobate.

The thermal annealing of amorphous tracks of nanometer-size diameter generated in lithium niobate (LiNbO3) by Bromine ions at 45 MeV, i.e., in the electronic stopping regime, has been investigated by RBS/C spectrometry in the temperature range from 250°C to 350°C. Relatively low fluences have been used (<1012 cm−2) to produce isolated tracks. However, the possible effect of track overlapping has been investigated by varying the fluence between 3×1011 cm−2 and 1012 cm−2. The annealing process follows a two-step kinetics. In a first stage (I) the track radius decreases linearly with the annealing time. It obeys an Arrhenius-type dependence on annealing temperature with activation energy around 1.5 eV. The second stage (II) operates after the track radius has decreased down to around 2.5 nm and shows a much lower radial velocity. The data for stage I appear consistent with a solid-phase epitaxial process that yields a constant recrystallization rate at the amorphous-crystalline boundary. HRTEM has been used to monitor the existence and the size of the annealed isolated tracks in the second stage. On the other hand, the thermal annealing of homogeneous (buried) amorphous layers has been investigated within the same temperature range, on samples irradiated with Fluorine at 20 MeV and fluences of ∼1014 cm−2. Optical techniques are very suitable for this case and have been used to monitor the recrystallization of the layers. The annealing process induces a displacement of the crystalline-amorphous boundary that is also linear with annealing time, and the recrystallization rates are consistent with those measured for tracks. The comparison of these data with those previously obtained for the heavily damaged (amorphous) layers produced by elastic nuclear collisions is summarily discussed