Recubrimientos nanoestructurados de circonia estabilzada con itria (ysz) depositados mediante técnicas de termorrociado por plasma en suspensión

Las propiedades de los recubrimientos a base de circonia estabilizada con ytria (YSZ) les confieren un excelente desempeño como barreras térmicas (TBC). En el presente trabajo, recubrimientos de 8YSZ fueron depositados sobre Haynes 230 mediante el proceso de termorrociado por plasma por suspensión (SPS) con el fin de servir de enlace (subcapa) entre el sustrato y un recubrimiento más grueso de YSZ, depositado por termorrociado por plasma atmosférico (APS). Se estudió el efecto del espesor de la subcapa depositada por SPS y la influencia de los tratamientos térmicos posteriores (TT) a 300°C y 600°C sobre su desempeño tribológico a temperatura ambiente (Tamb) y 650°C, respectivamente. Durante los ensayos de desgaste deslizante con una carga de 2 N contra alúmina, se determinó que la reducción del espesor del recubrimiento de 75 μm a 25 μm incrementa la resistencia al desgaste aproximadamente 5 veces. Asimismo, para el espesor de 25 μm el TT a la temperatura de 600°C disminuye 6 veces su resistencia al desgaste con respecto a la condición original del recubrimiento. Similarmente, cuando el ensayo se realizó a 650°C, el comportamiento tribológico desmejoró significativamente. Los resultados han sido relacionados con los cambios morfológicos que tienen lugar durante el calentamiento

Nutrition in formation of alimentary-dependent pathology in adolescents

The aim of the study - was to assess the actual nutrition, nutritional status of adolescents in order to identify risk factors for alimentary-dependent pathologyЦель исследования – оценить фактическое питание, пищевой статус подростков с целью выявления факторов риска алиментарно-зависимой патологии

Reduced response to IKr blockade and altered hERG1a/1b stoichiometryin human heart failure

Heart failure (HF) claims 250,000 lives per year in the US, and nearly half of these deaths are sudden and presumably due to ventricular tachyarrhythmias. QT interval and action potential (AP) prolongation are hallmark proarrhythmic changes in the failing myocardium, which potentially result from alterations in repolarizing potassium currents. Thus,we aimed to examinewhether decreased expression of the rapid delayed rectifier potassiumcurrent, IKr, contributes to repolarization abnormalities in human HF. Tomap functional IKr expression across the left ventricle (LV), we optically imaged coronary-perfused LV free wall from donor and end-stage failing human hearts. The LV wedge preparation was used to examine transmural AP durations at 80% repolarization (APD80), and treatment with the IKr-blocking drug, E-4031, was utilized to interrogate functional expression. We assessed the percent change in APD80 post-IKr blockade relative to baseline APD80 (ΔAPD80) and found that ΔAPD80s are reduced in failing versus donor hearts in each transmural region, with 0.35-, 0.43-, and 0.41-fold reductions in endo-, mid-, and epicardium, respectively (p = 0.008, 0.037, and 0.022). We then assessed hERG1 isoform gene and protein expression levels using qPCR and Western blot. While we did not observe differences in hERG1a or hERG1b gene expression between donor and failing hearts, we found a shift in the hERG1a:hERG1b isoform stoichiometry at the protein level. Computer simulations were then conducted to assess IKr block under E-4031 influence in failing and nonfailing conditions. Our results confirmed the experimental observations and E-4031-induced relative APD80 prolongationwas greater in normal conditions than in failing conditions, provided that the cellularmodel of HF included a significant downregulation of IKr. In humanHF, the response to IKr blockade is reduced, suggesting decreased functional IKr expression. This attenuated functional response is associated with altered hERG1a:hERG1b protein stoichiometry in the failing human LV, and failing cardiomyoctye simulations support the experimental findings. Thus, of IKr protein and functional expression may be important determinants of repolarization remodeling in the failing human LV.We thank the Translational Cardiovascular Biobank & Repository (TCBR) at Washington University for provision of donor/patient records. The TCBR is supported by the NIH/CTSA (UL1 TR000448), Children's Discovery Institute, and Richard J. Wilkinson Trust. We also thank the laboratory of Dr. Sakiyama-Elbert for the use of the StepOnePlus equipment We appreciate the critical feedback on the manuscript by Dr. Jeanne Nerbonne. This work has been supported by the National Heart, Lung & Blood Institute (NHLBI, R01 HL114395). K. Holzem has been supported by the American Heart Association (12PRE12050315) and the NHLBI (F30 HL114310).Holzem, KM.; Gómez García, JF.; Glukhov, AV.; Madden, EJ.; Koppel, AC.; Ewald, GA.; Trénor Gomis, BA.... (2016). Reduced response to IKr blockade and altered hERG1a/1b stoichiometryin human heart failure. Journal of Molecular and Cellular Cardiology. 96:82-92. https://doi.org/10.1016/j.yjmcc.2015.06.008S82929

Development and recent progress on ammonia synthesis catalysts for Haber–Bosch process

Due to its essential use as a fertilizer, ammonia synthesis from nitrogen and hydrogen is considered to be one of the most important chemical processes of the last 100 years. Since then, an enormous amount of work has been undertaken to investigate and develop effective catalysts for this process. Although the catalytic synthesis of ammonia has been extensively studied in the last century, many new catalysts are still currently being developed to reduce the operating temperature and pressure of the process and to improve the conversion of reactants to ammonia. New catalysts for the Haber–Bosch process are the key to achieving green ammonia production in the foreseeable future. Herein, the history of ammonia synthesis catalyst development is briefly described as well as recent progress in catalyst development with the aim of building an overview of the current state of ammonia synthesis catalysts for the Haber–Bosch process. The new emerging ammonia synthesis catalysts, including electride, hydride, amide, perovskite oxide hydride/oxynitride hydride, nitride, and oxide promoted metals such as Fe, Co, and Ni, are promising alternatives to the conventional fused‐Fe and promoted‐Ru catalysts for existing ammonia synthesis plants and future distributed green ammonia synthesis based on the Haber–Bosch process