35 research outputs found
Effects of the Fruit Ripening Stage on Antioxidant Capacity, Total Phenolics, and Polyphenolic Composition of Crude Palm Oil from Interspecific Hybrid Elaeis oleifera × Elaeis guineensis
Major histocompatibility complex class I molecules protect motor neurons from astrocyte-induced toxicity in amyotrophic lateral sclerosis
Astrocytes isolated from individuals with amyotrophic lateral sclerosis (ALS) are toxic to motor neurons (MNs) and play a non–cell autonomous role in disease pathogenesis. The mechanisms underlying the susceptibility of MNs to cell death remain unclear. Here we report that astrocytes derived from either mice bearing mutations in genes associated with ALS or human subjects with ALS reduce the expression of major histocompatibility complex class I (MHCI) molecules on MNs; reduced MHCI expression makes these MNs susceptible to astrocyte-induced cell death. Increasing MHCI expression on MNs increases survival and motor performance in a mouse model of ALS and protects MNs against astrocyte toxicity. Overexpression of a single MHCI molecule, HLA-F, protects human MNs from ALS astrocyte–mediated toxicity, whereas knockdown of its receptor, the killer cell immunoglobulin-like receptor KIR3DL2, on human astrocytes results in enhanced MN death. Thus, our data indicate that, in ALS, loss of MHCI expression on MNs renders them more vulnerable to astrocyte-mediated toxicity
Desarrollo de herramientas virtuales para la enseñanza de la termodinámica básica
Se construyeron herramientas virtuales para ser utilizados como apoyo docente en la enseñanza de la termodinámica básica de carreras de ingeniería de la Universidad de América. Los programas cuentan con una excelente interfase hombre maquina que facilita mucho su uso por parte de alumnos inexpertos en el área y fueron realizados en LabVIEW por estudiantes de semestres superiores de Ingeniería . El impacto de estas herramientas se midió en un curso de 25 estudiantes obteniendo excelentes resultados
Removal of an emergent contaminant by a palygorskite from Pontezuela/Cuban region
Water pollution associated to pharmaceutical and personal care products has become a serious environmental issue. A reasonable strategy to mitigate the problem involves adsorbing materials. In particular, the use of clays is an advantageous alternative considering their high adsorption capacity and compatibility with the environment. In the present work, the efficacy of an unmodified Cuban clay (palygorskite, Pal) as nanosupport of sulfamethoxazole (SMX)—an antibiotic considered an emerging contaminant (EC) was demonstrated. In order to establish the best conditions to increase the drug capture by the clay, the influence of physical–chemical parameters was studied. The amount of SMX incorporated onto the clay was determined by UV spectroscopy. The resulting composite material was characterized by infrared spectroscopy (IR), X-ray diffraction (XRD), thermogravimetric analysis (TG/DTG), zeta potential (ZP), nitrogen adsorption measurements, transmission electron microscopy (TEM) and scanning electron microscopy with energy dispersive spectroscopy (SEM–EDS). Drug desorption studies were performed on the SMX-charged clay, indicating the reversibility of the incorporation process. The results suggest the potential use of Cuban natural palygorskite for water decontamination.Fil: Hernández, D.. Universidad de La Habana; CubaFil: Quiñones, L.. Universidad de La Habana; CubaFil: Lazo Delgado, Lismet. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Física Aplicada "Dr. Jorge Andrés Zgrablich". Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto de Física Aplicada "Dr. Jorge Andrés Zgrablich"; ArgentinaFil: Charnay, C.. Centre National de la Recherche Scientifique; FranciaFil: Velázquez, M.. No especifíca;Fil: Altshuler, E.. Universidad de La Habana; CubaFil: Rivera, A.. Universidad de La Habana; Cub
New copper carboxylate pyrene dimers: synthesis, crystal structure, Hirshfeld surface analysis and electrochemical characterization
Two new copper dimers, namely, bis(dimethyl sulfoxide)tetrakis(μ-pyrene-1-carboxylato)dicopper(Cu—Cu), [Cu2(C17H9O2)4(C2H6OS)2] or [Cu2(pyr-COO−)4(DMSO)2] (1), and bis(dimethylformamide)tetrakis(μ-pyrene-1-carboxylato)dicopper(Cu—Cu), [Cu2(C17H9O2)4(C3H7NO)2] or [Cu2(pyr-COO−)4(DMF)2] (2) (pyr = pyrene), were synthesized from the reaction of pyrene-1-carboxylic acid, copper(II) nitrate and triethylamine from solvents DMSO and DMF, respectively. While 1 crystallized in the space group P\overline{1}, the crystal structure of 2 is in space group P21/n. The Cu atoms have octahedral geometries, with four oxygen atoms from carboxylate pyrene ligands occupying the equatorial positions, a solvent molecule coordinating at one of the axial positions, and a Cu...Cu contact in the opposite position. The packing in the crystal structures exhibits π–π stacking interactions and short contacts through the solvent molecules. The Hirshfeld surfaces and two-dimensional fingerprint plots were generated for both compounds to better understand the intermolecular interactions and the contribution of heteroatoms from the solvent ligands to the crystal packing. In addition, a Cu2+/Cu1+ quasi-reversible redox process was identified for compound 2 using cyclic voltammetry that accounts for a diffusion-controlled electron-donation process to the Cu dimer