145 research outputs found
Water Chemisorption and Reconstruction of the MgO Surface
The observed reactivity of MgO with water is in apparent conflict with
theoretical calculations which show that molecular dissociation does not occur
on a perfect (001) surface. We have performed ab-initio total energy
calculations which show that a chemisorption reaction involving a
reconstruction to form a (111) hydroxyl surface is strongly preferred with
Delta E = -90.2kJ/mol. We conclude that protonation stabilizes the otherwise
unstable (111) surface and that this, not the bare (001), is the most stable
surface of MgO under ambient conditions.Comment: RevTeX, 4 pages, 1 Encapsulated Postscript Figur
Artificial Pancreas: First Clinical Trials in Argentina
The first clinical trials using an Artificial Pancreas (AP) in Latin America have been defined in 2 stages. The first stage was carried out in November 2016 with the UVA controller (developed by the Center for Diabetes Technology and already clinically tested), and the second will be performed during the first semester of 2017 with the ARG (Automatic Regulation of Glucose) algorithm (developed by ITBA, UNQ, and UNLP in Argentina). Both tests are based on the DiAs (Diabetes Assistant) from the UVA, and are performed in the HIBA on 5 patients with Type 1 Diabetes Mellitus (T1DM), for 36 hours. For the first stage, Open-Loop (OL) insulin boluses were applied before meals and patient’s physical activity was included. On the other hand, for the second stage, patients will not be involved in physical activity, but no OL insulin boluses will be injected before meals. In this work, experimental results from the first stage with the UVA controller, and preliminary results with the ARG control algorithm tested on the UVA/Padova simulator are presented. Due to the final paper deadline, the experimental results from the second stage are not included here, but will be presented at the IFAC World Congress.Facultad de IngenieríaInstituto de Investigaciones en Electrónica, Control y Procesamiento de Señale
A Randomized Trial of Convalescent Plasma in Covid-19 Severe Pneumonia
BACKGROUND:Convalescent plasma is frequently administered to patients with Covid-19 and hasbeen reported, largely on the basis of observational data, to improve clinical outcomes.Minimal data are available from adequately powered randomized, controlled trials.
METHODS:We randomly assigned hospitalized adult patients with severe Covid-19 pneumoniain a 2:1 ratio to receive convalescent plasma or placebo. The primary outcome wasthe patient?s clinical status 30 days after the intervention, as measured on a six-pointordinal scale ranging from total recovery to death.
RESULTS:A total of 228 patients were assigned to receive convalescent plasma and 105 toreceive placebo. The median time from the onset of symptoms to enrollment inthe trial was 8 days (interquartile range, 5 to 10), and hypoxemia was the mostfrequent severity criterion for enrollment. The infused convalescent plasma had amedian titer of 1:3200 of total SARS-CoV-2 antibodies (interquartile range, 1:800 to1:3200]. No patients were lost to follow-up. At day 30 day, no significant differencewas noted between the convalescent plasma group and the placebo group in thedistribution of clinical outcomes according to the ordinal scale (odds ratio, 0.83(95% confidence interval [CI], 0.52 to 1.35; P=0.46). Overall mortality was 10.96%in the convalescent plasma group and 11.43% in the placebo group, for a risk difference of −0.46 percentage points (95% CI, −7.8 to 6.8). Total SARS-CoV-2 antibodytiters tended to be higher in the convalescent plasma group at day 2 after the intervention. Adverse events and serious adverse events were similar in the two groups.
CONCLUSIONS:no significant differences were observed in clinical status or overall mortality between patients treated with convalescent plasma and those who received placebo.(PlasmAr ClinicalTrials.gov number, NCT04383535.)Fil: Simonovich, Ventura A.. Hospital Italiano. Departamento de Medicina. Servicio de Clinica Medica.; ArgentinaFil: Burgos Pratx, Leandro D.. Hospital Italiano. Departamento de Medicina. Servicio de Clinica Medica.; ArgentinaFil: Scibona, Paula. Hospital Italiano. Departamento de Medicina. Servicio de Clinica Medica.; ArgentinaFil: Beruto, Maria Valeria. No especifíca;Fil: Vallone, Miguel Gabriel. No especifíca;Fil: Vázquez, C.. No especifíca;Fil: Savoy, N.. No especifíca;Fil: Giunta, Diego Hernan. No especifíca;Fil: Pérez, L.G.. No especifíca;Fil: Sánchez, M.L.. No especifíca;Fil: Gamarnik, Andrea Vanesa. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquímicas de Buenos Aires. Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas de Buenos Aires; ArgentinaFil: Ojeda, D.S.. No especifíca;Fil: Santoro, D.M.. No especifíca;Fil: Camino, P. J.. No especifíca;Fil: Antelo, S.. No especifíca;Fil: Rainero, K.. No especifíca;Fil: Vidiella, G. P.. No especifíca;Fil: Miyazaki, E. A.. No especifíca;Fil: Cornistein, W.. No especifíca;Fil: Trabadelo, O. A.. No especifíca;Fil: Ross, F. M.. No especifíca;Fil: Spotti, M.. No especifíca;Fil: Funtowicz, G.. No especifíca;Fil: Scordo, W. E.. No especifíca;Fil: Losso, M. H.. No especifíca;Fil: Ferniot, I.. No especifíca;Fil: Pardo, P. E.. No especifíca;Fil: Rodriguez, E.. No especifíca;Fil: Rucci, P.. No especifíca;Fil: Pasquali, J.. No especifíca;Fil: Fuentes, N. A.. No especifíca;Fil: Esperatti, M.. No especifíca;Fil: Speroni, G. A.. No especifíca;Fil: Nannini, Esteban. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Inmunología Clinica y Experimental de Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Médicas. Instituto de Inmunología Clinica y Experimental de Rosario; ArgentinaFil: Matteaccio, A.. No especifíca;Fil: Michelangelo, H.G.. No especifíca;Fil: Follmann, D.. No especifíca;Fil: Lane, H. Clifford. No especifíca;Fil: Belloso, Waldo Horacio. Hospital Italiano. Departamento de Medicina. Servicio de Clinica Medica.; Argentin
Influence of agar on in vitro cultures: I. Physicochemical properties of agar and agar gelled media.
Recommended from our members
RESPONSE TO COMMENTS ON ""KINETICS OF ENDOTHERMIC DESOMPOSITION REACTIONS 2. EFFECTS OF SOLID AND GASEOUS PRODUCTS.""
Recommended from our members
STRAIN INDUCED PHENOMENA IN Ca(OH)2 MADE BY REACTION OP CaO WITH WATER VAPOR
Recommended from our members
CHARACTERIZATION OF THE POROUS CaO PARTICLES FORMED BY DECOMPOSITION OF CaC03 AND Ca(0H)2 IN VACUUM
Adsorption of Paraffin Vapour on Oxidized Molybdenum Substrates at Nano and Micro Scales
Sputtered oxidized molybdenum surfaces were exposed at room temperature for different times to paraf\ufb01n vapors obtained at 150\u25e6C. Scanning polarization force microscopy (SPFM), optical and confocal microscopy were used to characterize the surfaces. The condensed morphologies are complex and strongly dependent upon the quantity of vapor molecules deposited on the substrate surface. A thin paraf\ufb01n \ufb01lm is initially formed
and quite uniform nano-height drops are nucleated randomly over it within 10\u201320 s time exposures. Their average contact angle ranged between 1\u25e6 + \u20132.5\u25e6. Further vapor deposition led to a more complex regime where nano-height drops do not show a clear interface with the \ufb01lm, while micro-sized drops do. The tangent approximation method adopted by Salmeron and Xu for the nano-drop regimes was extended to the micro-sized drop
regime obtaining an averaged effective contact angle equal to 4\u25e6 + \u20135\u25e6. Both nano-height and micro-sized drops shape and effective contact angles have been discussed taking into account their interactions between the \ufb01lm and the drops
- …