The CCR4-NOT deadenylase complex controls Atg7-dependent cell death and heart function

Shortening and removal of the polyadenylate [poly(A)] tail of mRNA, a process called deadenylation, is a key step in mRNA decay that is mediated through the CCR4-NOT (carbon catabolite repression 4-negative on TATA-less) complex. In our investigation of the regulation of mRNA deadenylation in the heart, we found that this complex was required to prevent cell death. Conditional deletion of the CCR4-NOT complex components Cnot1 or Cnot3 resulted in the formation of autophagic vacuoles and cardiomyocyte death, leading to lethal heart failure accompanied by long QT intervals. Cnot3 bound to and shortened the poly(A) tail of the mRNA encoding the key autophagy regulator Atg7. In Cnot3-depleted hearts, Atg7 expression was posttranscriptionally increased. Genetic ablation of Atg7, but not Atg5, increased survival and partially restored cardiac function of Cnot1 or Cnot3 knockout mice. We further showed that in Cnot3-depleted hearts, Atg7 interacted with p53 and modulated p53 activity to induce the expression of genes encoding cell death-promoting factors in cardiomyocytes, indicating that defects in deadenylation in the heart aberrantly activated Atg7 and p53 to promote cell death. Thus, mRNA deadenylation mediated by the CCR4-NOT complex is crucial to prevent Atg7-induced cell death and heart failure, suggesting a role for mRNA deadenylation in targeting autophagy genes to maintain normal cardiac homeostasis

Performance Analysis of Thermoelectric Modules Consisting of Square Truncated Pyramid Elements Under Constant Heat Flux

System design of a thermoelectric (TE) power generation module is pursued in order to improve the TE performance. Square truncated pyramid shaped P-N pairs of TE elements are connected electronically in series in the open space between two flat insulator boards. The performance of the TE module consisting of 2-paired elements is numerically simulated using commercial software and original TE programs. Assuming that the heat radiating into the hot surface is regulated, i.e., the amount of heat from the hot surface to the cold one is steadily constant, as it happens for solar radiation heating, the performance is significantly improved by changing the shape and the alignment pattern of the elements. When the angle theta between the edge and the base is smaller than 72 degrees, and when the cold surface is kept at a constant temperature, two patterns in particular, amongst the 17 studied, show the largest TE power and efficiency. In comparison to other geometries, the smarter square truncated pyramid shape can provide higher performance using a large cold bath and constant heat transfer by heat radiation

Conversion of CO2 to CO gas using molten CaCl2 and ZrO2 anode

Preferential decomposition of CO2 gas to CO gas was examined by using a combination of CaCl2-CaO melt as a reaction media and ZrO2-8mol% Y2O3 solid-state electrolyte as anode. The conversion ratio of CO2 to CO became larger at the higher temperature, and approached the maximum (88.2%) at 1273 K. The highest CO concentration was generated at cell voltage of 2.55 V, which is close to theoretical decomposition voltage of CaO. Therefore, in addition to calciothermic reaction between precipitated Ca and CO2 gas bubbles, CO2 decomposes preferentially via the decomposition reaction of carbonate ions. Namely CO2 gas dissolves to form CO3 2- under coexistence of CaO in the melt, CO3 2- precipitates carbon or CO gas bubbles on the cathode, and a part of carbon reacts with the blown CO2 gas to form CO. CO gas is used as an effective fuel with easy handling in steel plants

Electrochemical and morphological characterization of porous alumina formed by galvanostatic anodizing in etidronic acid

Electrochemical and morphological characterization of the porous alumina formed by galvanostatic anodizing in etidronic acid under various operating conditions was performed. High-purity aluminum plates were anodized in 0.03-3 M etidronic acid solutions at 273-333 K and 0.25-500 Am-2 for up to 24 h. Galvanostatic anodizing in etidronic acid operated over a wide range voltage measuring from a few V to 246 V. The time required for the steady growth of porous alumina not only depends on the current density but also the temperature and the concentration of the electrolyte solution during galvanostatic anodizing. The average, maximum, and minimum cell sizes of the porous alumina were directly proportional to the anodizing voltage with a proportionality constant of 2.5, 3.5 and 0.7, respectively, and were independent of other parameters. The number density of the cell was also a function of the anodizing voltage and agreed with the theoretical value obtained for ordered porous alumina with an ideal honeycomb distribution. The maximum voltage measured during galvanostatic anodizing was linearly proportional to the plateau voltage with a proportionality constant of 1.4. (C) 2019 Elsevier Ltd. All rights reserved

Optimum Exploration for the Self-Ordering of Anodic Porous Alumina Formed via Selenic Acid Anodizing

Improvements of the regularity of the arrangement of anodic porous alumina formed by selenic acid anodizing were investigated under various operating conditions. The oxide burning voltage increased with the stirring rate of the selenic acid solution, and the high applied voltage without oxide burning was achieved by vigorously stirring the solution. The regularity of the porous alumina was improved as the anodizing time and surface flatness increased. Conversely, the purity of the 99.5–99.9999 wt% aluminum specimens without second phases of metals and metallic compounds was not affected by the regularity of the porous alumina formed by selenic acid anodizing. The porous alumina was also self-ordered on/around a defect, such as a grain boundary, under self-ordering high voltage anodizing conditions. A highly ordered cell arrangement measuring 111 nm in diameter was successfully fabricated over the whole aluminum surface by selenic acid anodizing using a 99.999 wt% aluminum plate at 273 K and 46 V for 24 h under vigorous stirring conditions

Fabrication of self-ordered porous alumina via anodizing in sulfate solutions

Self-ordered porous alumina was fabricated via anodizing in an acid salt electrolyte solution, sodium hydrogen sulfate (NaHSO4). High-purity aluminum specimens were anodized in a NaHSO4 solution under various operating conditions with adjusted concentrations, temperatures, applied voltages, and times. Self-ordering was achieved via NaHSO4 anodizing at appropriate applied voltages ranging from 20 to 28 V, and ordered cell arrangements with the cell size of 55-77 nm were successfully fabricated. Sulfur atoms originating from the electrolyte anions were incorporated into the ordered porous alumina. A honeycomb distribution consisting of a thick outer layer with a high concentration of sulfur and a very thin inner skeleton with a relatively low concentration sulfur was formed via NaHSO4 anodizing. Our results suggested that there are now many electrolyte options for the fabrication of self-ordered porous alumina with a wide range of nanosizes

Rapid fabrication of self-ordered porous alumina with 10-/sub-10-nm-scale nanostructures by selenic acid anodizing

Anodic porous alumina has been widely investigated and used as a nanostructure template in various nanoapplications. The porous structure consists of numerous hexagonal cells perpendicular to the aluminum substrate and each cell has several tens or hundreds of nanoscale pores at its center. Because the nanomorphology of anodic porous alumina is limited by the electrolyte during anodizing, the discovery of additional electrolytes would expand the applicability of porous alumina. In this study, we report a new self-ordered nanoporous alumina formed by selenic acid (H2SeO4) anodizing. By optimizing the anodizing conditions, anodic alumina possessing 10-nm-scale pores was rapidly assembled (within 1 h) during selenic acid anodizing without any special electrochemical equipment. Novel sub-10-nm-scale spacing can also be achieved by selenic acid anodizing and metal sputter deposition. Our new nanoporous alumina can be used as a nanotemplate for various nanostructures in 10-/sub-10-nm-scale manufacturing

Advancing and receding contact angle investigations for highly sticky and slippery aluminum surfaces fabricated from nanostructured anodic oxide

The fabrication of sticky and slippery superhydrophobic aluminum was achieved by anodizing in pyrophosphoric acid and modification with self-assembled monolayers (SAMs). In addition, the corresponding sliding behaviors of a water droplet were investigated by contact angle measurements and direct observations. For the formation of anodic alumina nanofibers, 4N aluminum plates were anodized in a concentrated pyrophosphoric acid solution at 25-75 V. The morphology of the anodic oxide successively changed to barrier oxide, porous oxide, nanofibers, bundle structures with many nanofibers, and then weak nanofibers during anodizing. The anodized specimens were immersed in a fluorinated phosphonic acid/ethanol solution to form SAMs on the surface of the anodic oxide. The contact angle hysteresis drastically changed with anodizing time: it increased with the formation of porous oxide, decreased for the nanofibers and bundle structures, and then increased once again for the weak nanofibers. Correspondingly, the adhesion interaction between the water droplet and the aluminum surface also drastically changed to show sticky, slippery, and sticky behaviors with anodizing time. More sticky and slippery aluminum surfaces can be obtained by anodizing at higher voltages. The slippery behavior was further improved through two distinct anodizing processes with the formation of ordered alumina nanofibers. A superhydrophobic aluminum surface with coexisting sticky and slippery properties was fabricated by the selective anodizing method