Insights on Structural Evolution and Charge Storage Mechanism of Na4Mn9O18 as Active Material for Aqueous Rechargeable Sodium-Ion Storage Systems

As a renewable and sustainable energy storage technology, aqueous rechargeable sodium-ion storage systems have raised great interest due to environmental friendliness, safety and low cost. Unlike conventional lithium-ion batteries, aqueous sodium-ion systems have some distinct advantages for large-scale stationary electric storage, such as the abundant natural resource of Na and the possibility to achieve long-term stability and reversibility. In addition, aqueous electrolytes are inherently safer and more eco-friendly than organic electrolytes [1]. On the other hand, the use of aqueous electrolytes poses significant challenges in the selection of electrode materials. First, their redox potentials should be within the electrochemical stability window of water. Second, the side reactions between electrode materials and H2O or residual O2 may tremendously affect their cyclic stability [2]. Among the different eligible materials, channeled structure Na4Mn9O18 (NMO) is still one of the most promising candidate as cathodic material for aqueous Na-ion storage systems, because of its abundance, low price ($7.6 kg-1[3]), relatively high theoretical capacity (121 mAh g-1), non-toxicity, and simple synthesis by different routes. However, this material has yet to be characterized in detail in terms of its storage mechanisms and stability performance in aqueous environment. In this study, we undertake an in depth characterization of the kinetics of NMO electrode processes in 1 M Na2SO4 electrolyte, within its safe potential window in thiselectrolyte, namely 0.25-1.1 VSHE, as defined in the present work. We use cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) to deconvolve the complex behavior of this system and discriminate the different contributions of double-layer capacitance, pseudocapacitance and sodium ion insertion to charge/discharge at varying potential. First, by the power law analysis of voltammetry we identify kinetic processes and make an evaluation of their respective contribution; then, the analysis and modeling of EIS measurements, performed at varying potential after equilibration of the system, allow us to calculate the currents associated with the above processes at varying potential and as a function of the frequency. In particular, the EIS method proves that the diffusional or intercalation contribution is dominant over the entire safe potential window. The latter methodology holds great promise to be a powerful tool for an effective deconvolution of the complex behavior of the NMO / aqueous electrolyte system, enabling an in depth understanding of the role of different processes in its dynamic performance

Biochemical, structural, and biological evaluation of tranylcypromine derivatives as inhibitors of histone demethylases LSD1 and LSD2.

LSD1 and LSD2 histone demethylases are implicated in a number of physiological and pathological processes, ranging from tumorigenesis to herpes virus infection. A comprehensive structural, biochemical, and cellular study is presented here to probe the potential of these enzymes for epigenetic therapies. This approach employs tranylcypromine as a chemical scaffold for the design of novel demethylase inhibitors. This drug is a clinically validated antidepressant known to target monoamine oxidases A and B. These two flavoenzymes are structurally related to LSD1 and LSD2. Mechanistic and crystallographic studies of tranylcypromine inhibition reveal a lack of selectivity and differing covalent modifications of the FAD cofactor depending on the enantiomeric form. These findings are pharmacologically relevant, since tranylcypromine is currently administered as a racemic mixture. A large set of tranylcypromine analogues were synthesized and screened for inhibitory activities. We found that the common evolutionary origin of LSD and MAO enzymes, despite their unrelated functions and substrate specificities, is reflected in related ligand-binding properties. A few compounds with partial enzyme selectivity were identified. The biological activity of one of these new inhibitors was evaluated with a cellular model of acute promyelocytic leukemia chosen since its pathogenesis includes aberrant activities of several chromatin modifiers. Marked effects on cell differentiation and an unprecedented synergistic activity with antileukemia drugs were observed. These data demonstrate that these LSD1/2 inhibitors are of potential relevance for the treatment of promyelocytic leukemia and, more generally, as tools to alter chromatin state with promise of a block of tumor progression

Comparison of Neck Skin Excision and Whole Carcass Rinse Sampling Methods for Microbiological Evaluation of Broiler Carcasses before and after Immersion Chilling

Sampling protocols for detecting Salmonella on poultry differ among various countries. In the United States, the U.S. Department of Agriculture Food Safety and Inspection Service dictates that whole broiler carcasses should be rinsed with 400 ml of 1% buffered peptone water, whereas in the European Union 25-g samples composed of neck skin from three carcasses are evaluated. The purpose of this study was to evaluate a whole carcass rinse (WCR) and a neck skin excision (NS) procedure for Salmonella and Escherichia coli isolation from the same broiler carcass. Carcasses were obtained from three broiler processing plants. The skin around the neck area was aseptically removed and bagged separately from the carcass, and microbiological analysis was performed. The corresponding carcass was bagged and a WCR sample was evaluated. No significant difference (alpha <= 0.05) in Salmonella prevalence was found between the samples processed by the two methods, but both procedures produced many false-negative Salmonella results. Prechill, 37% (66 carcasses), 28% (50 carcasses), and 51% (91 carcasses) of the 180 carcasses examined were positive for Salmonella by WCR, NS, and both procedures combined, respectively. Postchill, 3% (5 carcasses), 7% (12 carcasses), and 10% (17 carcasses) of the 177 carcasses examined were positive for Salmonella by the WCR, NS, and combination of both procedures, respectively. Prechill, E. coli plus coliform counts were 3.0 and 2.6 log CFU/ml by the WCR and NS methods, respectively. Postchill. E. coli plus coliform counts were 1.7 and 1.4 log CFU/ml by the WCR and NS methods, respectively

Novel non-covalent LSD1 inhibitors endowed with anticancer effects in leukemia and solid tumor cellular models

LSD1 is a histone lysine demethylase proposed as therapeutic target in cancer. Chemical modifications applied at C2, C4 and/or C7 positions of the quinazoline core of the previously reported dual LSD1/G9a inhibitor 1 led to a series of non-covalent, highly active, and selective LSD1 inhibitors (2–4 and 6–30) and to the dual LSD1/G9a inhibitor 5 that was more potent than 1 against LSD1. In THP-1 and MV4-11 leukemic cells, the most potent compounds (7, 8, and 29) showed antiproliferative effects at sub-micromolar level without significant toxicity at 1 μM in non-cancer AHH-1 cells. In MV4-11 cells, the new derivatives increased the levels of the LSD1 histone mark H3K4me2 and induced the re-expression of the CD86 gene silenced by LSD1, thereby confirming the inhibition of LSD1 at cellular level. In breast MDA-MB-231 as well as in rhabdomyosarcoma RD and RH30 cells, taken as examples of solid tumors, the same compounds displayed cell growth arrest in the same IC50 range, highlighting a crucial anticancer role for LSD1 inhibition and suggesting no added value for the simultaneous G9a inhibition in these tumor cell lines

Humanidades: la ética en el inicio del siglo XXI

La reflexión propuesta por el V Congreso: Humanidades: La Ética en el Siglo XXI, planteó un desafío que fue asumido con altura por los participantes en el evento. La crisis de la Ética, entendida como conjunto de reglas prácticas que a partir de la razón crítica dan sentido y finalidad a la acción de la persona y la sociedad, está presente en forma indubitable, desde las primeras décadas del Siglo XIX, cuando la idea del lucro, la utilidad y la libertad económica y de mercado, fue asumida, y se impuso en forma excluyente, sobre la libertad individual y la dignidad esencial del ser humano, entendido, desde el Renacimiento, como el sujeto y destinatario de la historia. V Congreso Latinoamericano de las Humanidades. Realizado del 25 al 28 de Septiembre 2001 en la Ciudad de Granada, Nicaragua, Convento San francisco.Prólogo del señor Serrano; Antecedentes del V Congreso; Ponencias: El humanismo esperanzado, Alejandro Serrano Caldera; Ética y política: Una nueva cultura política para america latina, Carlos Tunnermann; Ética en el ámbito de la política, Róger Mendieta Alfaro; Nietzsche y la política de la transvaloracion, Melvin Javier Paredes; Por una ética acrata: del dominio a la concertación, José Manuel Maldonado; Ética y corrupción, Oscar René Vargas; Ética y educación: La crisis de las humanidades, Erwin Silva; La memoria y el olvido, Víctor Valembois; Conocimiento historico y verdad, Elsie R. de Powell; Conflicto, convivencia y autonomia en las instituciones educativas, Manuel Bolivar Godoy; La mediación pedagógica: una nueva perspectiva en la formación de valores educativos, Olga María Abaunza y Francisco Mendoza; La construcción del curriculo: una opción ética, Alicia Sequeira; La comunidad educativa, Matilde Obando Enríquez; Reflexiones sobre la oferta y la demanda de la educación superior nicaragüense, Arturo Collado Maldonado; Ética y educación superior en la era de la globalización, perspectiva latinoamericana, Jacinto Ordóñez Peñalosa; Ética, desarrollo y genero: Ética y los problemas de desarrollo en América Latina, Norma Rusconi y Patricia Cubillos; Compromiso social de los medios de comunicación por el desarrollo acusticamente sostenible, Doraldina Zeledón Ubeda, Federico Miyara, Jordy Mulet Arias; Empoderamiento femenino: alternativa etica del conflicto entre sexismo e identidad de genero. Una oferta equitativa en las grietas económicas del sistema, Aura Violeta Aldana; La mejor etica, la que no se puede decir, Freddy Quezada; Ecología social: ética para una ecología latinoamericana, Ester A. Previtera; Ética, ciencia y tecnología: Ética, ciencia y tecnología, Moisés Ladrón de Guevara; Ética profesional, Juan Sánchez Barquero; Ética y religión: Cristianismo, universidad y desafío ético, Jerjes Ruiz Castro; La fe cristiana y su aporte a la etica en nicaragua, José Miguel Torres; Discurso de clausura de la señora Mimi Hammer; Reseña de autores