Addition of aromatic nucleophiles to a C=N double bond of 1,2,5-thiadiazole 1,1-dioxide

A new synthesis of 3,4-diphenyl-4-aryl-1,2,5-thiadiazolines 1,1-dioxide through the addition of aromatic derivatives to 1,2,5-thiadiazole 1,1-dioxide is presented. Anhydrous AlCl3 is used as catalyst.Facultad de Ciencias Exacta

Addition of aromatic nucleophiles to a C=N double bond of 1,2,5-thiadiazole 1,1-dioxide

A new synthesis of 3,4-diphenyl-4-aryl-1,2,5-thiadiazolines 1,1-dioxide through the addition of aromatic derivatives to 1,2,5-thiadiazole 1,1-dioxide is presented. Anhydrous AlCl3 is used as catalyst.Facultad de Ciencias Exacta

Separación de gases mediante difusión por presión en una tobera curva

La evolución de la concentración de cada especie en una mezcla de gases se puede obtener a través de la ecuación de transporte por difusión, derivada de la teoría cinética de gases. Éste es el problema a resolver en procesos de separación de gases, como son por ejemplo los procesos centrífugos, las toberas curvas y la expansión libre o free-jet. En este trabajo nos enfocamos en la separación de gases que se genera a partir del gradiente de presión obtenido en una tobera curva. Se resolvieron las ecuaciones de Navier-Stokes de flujo compresible utilizando el código FLUENT de volúmenes finitos. Con las soluciones obtenidas se modeló el proceso de difusión de especies a partir de una ecuación constitutiva para los flujos de entrada y salida de los volúmenes finitos, donde se tiene en cuenta el efecto del gradiente de presión. Los resultados se compararon con datos experimentales de concentración de oxígeno en un flujo de aire.Fil: Guouzden, T.. Comisión Nacional de Energía Atómica; ArgentinaFil: Clausse, Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica; Argentina. Universidad Nacional del Centro de la Provincia de Buenos Aires; ArgentinaFil: Cortizo, E.. Comisión Nacional de Energía Atómica; ArgentinaFil: Fainstein, Pablo Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica; ArgentinaFil: Fiol, Juan. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica; ArgentinaFil: Fregenal, Daniel Eduardo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica; ArgentinaFil: Fuhr, Javier Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica; ArgentinaFil: Kaul, Enrique Eduardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; Argentina. Comisión Nacional de Energía Atómica; ArgentinaFil: Knoblauch, Pablo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Invap S. E.; ArgentinaFil: Lamagna, Alberto. Comisión Nacional de Energía Atómica; ArgentinaFil: Maceira, P.. Comisión Nacional de Energía Atómica; ArgentinaFil: Rozas, G.. Comisión Nacional de Energía Atómica; ArgentinaFil: Zarco, Maximiliano Alfredo. Comisión Nacional de Energía Atómica; Argentin

Dual antibacterial mechanism of [K4K15]CZS-1 against Salmonella Typhimurium: a membrane active and intracellular-targeting antimicrobial peptide

Salmonella genus is a leading cause of food-borne infections with strong public health impact and economic ramifications. The development of antimicrobial resistance added complexity to this scenario and turned the antibiotic drug discovery into a highly important challenge. The screening of peptides has served as a successful discovery platform to design new antibiotic candidates. Motivated by this, the antimicrobial and cytotoxic properties of three cruzioseptins against Salmonella Typhimurium and RAW 264.7 murine macrophage cells, respectively, were investigated. [K4K15]CZS-1 was the most potent antimicrobial peptide identified in the screening step with a minimum inhibitory concentration (MIC) of 16 μg/mL (7.26 μM) and moderate cytotoxicity. From a structural point of view, in vitro and in silico techniques evidenced that [K4K15]CZS-1 is a α-helical cationic antimicrobial peptide. In order to capture mechanistic details and fully decipher their antibacterial action, we adopted a multidimensional approach, including spectroscopy, electron microscopy and omics analysis. In general lines, [K4K15]CZS-1 caused membrane damage, intracellular alterations in Salmonella and modulated metabolic pathways, such as the tricarboxylic acid (TCA) cycle, fatty acid biosynthesis, and lipid metabolism. Overall, these findings provide deeper insights into the antibacterial properties and multidimensional mode of action of [K4K15]CZS-1 against Salmonella Typhimurium. In summary, this study represents a first step toward the screening of membrane-acting and intracellular-targeting peptides as potential bio-preservatives to prevent foodborne outbreaks caused by Salmonella

Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector

A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements