Histone modifications are key epigenetic regulatory features that have important roles in many cellular events. Lysine methylations mark various sites on the tail and globular domains of histones and ...their levels are precisely balanced by the action of methyltransferases ('writers') and demethylases ('erasers'). In addition, distinct effector proteins ('readers') recognize specific methyl-lysines in a manner that depends on the neighboring amino-acid sequence and methylation state. Misregulation of histone lysine methylation has been implicated in several cancers and developmental defects. Therefore, histone lysine methylation has been considered a potential therapeutic target, and clinical trials of several inhibitors of this process have shown promising results. A more detailed understanding of histone lysine methylation is necessary for elucidating complex biological processes and, ultimately, for developing and improving disease treatments. This review summarizes enzymes responsible for histone lysine methylation and demethylation and how histone lysine methylation contributes to various biological processes.
This article studies low-temperature sol–gel processed indium (In)-doped ZnO (IZO) for highly efficient organic photovoltaics (OPVs). Contrary to the prior research trends adopting doped sol–gel ...processed ZnO with an annealing temperature of over 400 °C for the hydrolysis reaction, IZO with an annealing temperature of 200 °C is studied. Similar to the high-temperature solvent system, it is elucidated that low-temperature sol–gel processed IZO effectively improves the performance of OPVs, increasing the power conversion efficiency from 6.80% to 7.35%. For further analyses, the current–voltage (J–V) characteristics and ideality factors (n) are examined as a function of In doping ratios, which revealed that In doping on ZnO effectively reduces trap-assisted recombination within devices.
Durability is a critical issue concerning energy-harvesting devices. Despite the energy-harvesting device’s excellent performance, moving components, such as the metal spring, can be damaged during ...operation. To solve the durability problem of the metal spring in a vibration-energy-harvesting (VEH) device, this study applied a non-contact magnetic spring to a VEH device using the repulsive force of permanent magnets. A laboratory experiment was conducted to determine the potential energy-harvesting power using the magnetic spring VEH device. In addition, the characteristics of the generated power were studied using the magnetic spring VEH device in a high-speed train traveling at 300 km/h. Through the high-speed train experiment, the power generated by both the metal spring VEH device and magnetic spring VEH device was measured, and the performance characteristics required for a power source for wireless sensor nodes in high-speed trains are discussed.
Herein, α-cellulose, d-xylose, and lignin, which are major lignocellulosic biomass constituents, are subject to being liquefied in scEtOH (supercritical ethanol). Biomass conversion, biocrude yield, ...gas composition and energy content resulting from the liquefaction are analyzed. When cellulose is used, the biocrude yield increased significantly from 1.6 to 48.4 wt% with an increase in temperature from 265 to 350 °C, while the yields of biocrudes obtained from lignin (25.2–28.8 wt%) and xylose (32.1–42.0 wt%) do not change significantly with varying temperature. The chemical composition of the biocrudes obtained from the cellulose and xylose liquefaction in scEtOH significantly differ when compared to those of the biocrudes obtained from fast pyrolysis and hydrothermal liquefaction. The unique chemical species in the scEtOH-liquefied biocrude include long-chain esters/ethers (C5–C10), long-chain acids (C4–C9), and tetrahydrofurans, which could be due to the enhanced esterification and hydrogenation reactions in the scEtOH medium. Plausible reaction pathways of xylose liquefaction in scEtOH are proposed.
•Cellulose, hydrolysis lignin, xylose are liquefied in supercritical ethanol.•Increase in biocrude yield when cellulose is used.•Biocrude yields are similar with temperature when lignin and xylose are used.•Long-chain esters/ethers/acids (C5–C10) and tetrahydrofurans form.•Esterification and hydrogenation are enhanced in supercritical ethanol.
Durability is one of the critical issues concerning energy harvesting devices. Even with the energy harvesting device’s excellent performance design, the moving components, such as the spring, get ...damaged during operation. In this study, an energy harvesting device was designed for durability improvement. The mechanical stopper of the energy harvesting device was selected as a new design component to prevent spring damage. An experimental and finite element analysis (FEA) was carried out on the amount of energy harvesting power possible using a mechanical stopper to improve the durability of the energy harvesting device. A performance evaluation of the energy harvesting device using the mechanical stopper was conducted under laboratory and driving conditions of a high-speed train traveling at 300 km/h. The measurement of the generated power gives the target value for the minimum performance of the newly designed energy harvesting device used as the power source of the wireless sensor node for high-speed trains.
This study is intended to identify the applicability of energy harvesting technologies that are regarded as new electrical power sources for the sensors on high-speed trains. The analytic estimation ...research is conducted on the amount of electric energy harvested from the high-speed trains, operating at a maximum speed of over 400km/h to verify the applicability of the energy harvesting technology converting the vibration energy of axle and bogie into electric power. Based on the data of the vibration acceleration on the axles and bogies, which were measured by using a 500 Hz analog filter, an analytic estimation on the amount of power harvested by an electromagnetic resonant harvester is conducted through the analysis of the main frequency. The power of the electromagnetic resonant harvester is based on a theoretical model of the mass-spring-damper system, and the harvested power from the axles and bogies in the vertical direction is analytically estimated in this study. The analytic calculations typically give the target value for the final performance of the electromagnetic resonant energy harvester. The targets of the analytic estimations are given to provide the basis for the detailed design and to give a basis for defining the basic design parameters of the electromagnetic resonant energy harvester.
Hard carbon is the most promising anode material for sodium‐ion batteries and potassium‐ion batteries owing to its high stability, widespread availability, low‐cost, and excellent performance. ...Understanding the carrier‐ion storage mechanism is a prerequisite for developing high‐performance electrode materials; however, the underlying ion storage mechanism in hard carbon has been a topic of debate because of its complex structure. Herein, it is demonstrated that the Li+‐, Na+‐, and K+‐ion storage mechanisms in hard carbon are based on the adsorption of ions on the surface of active sites (e.g., defects, edges, and residual heteroatoms) in the sloping voltage region, followed by intercalation into the graphitic layers in the low‐voltage plateau region. At a low current density of 3 mA g–1, the graphitic layers of hard carbon are unlocked to permit Li+‐ion intercalation, resulting in a plateau region in the lithium‐ion batteries. To gain insights into the ion storage mechanism, experimental observations including various ex situ techniques, a constant‐current constant‐voltage method, and diffusivity measurements are correlated with the theoretical estimation of changes in carbon structures and insertion voltages during ion insertion obtained using the density functional theory.
Li+, Na+, and K+ ions have identical storage mechanisms in hard carbon–adsorption followed by intercalation. The sloping voltage capacity is attributed to the adsorption of the carrier ions on defect sites, edge sites, and the surface of micropores, whereas the low‐voltage plateau capacity is caused by the intercalation of the carrier ions into graphitic layers.
Ferroptosis is an iron-dependent regulated necrosis mediated by lipid peroxidation. Cancer cells survive under metabolic stress conditions by altering lipid metabolism, which may alter their ...sensitivity to ferroptosis. However, the association between lipid metabolism and ferroptosis is not completely understood. In this study, we found that the expression of elongation of very longchain fatty acid protein 5 (ELOVL5) and fatty acid desaturase 1 (FADS1) is up-regulated in mesenchymal-type gastric cancer cells (GCs), leading to ferroptosis sensitization. In contrast, these enzymes are silenced by DNA methylation in intestinal-type GCs, rendering cells resistant to ferroptosis. Lipid profiling and isotope tracing analyses revealed that intestinal-type GCs are unable to generate arachidonic acid (AA) and adrenic acid (AdA) from linoleic acid. AA supplementation of intestinal-type GCs restores their sensitivity to ferroptosis. Based on these data, the polyunsaturated fatty acid (PUFA) biosynthesis pathway plays an essential role in ferroptosis; thus, this pathway potentially represents a marker for predicting the efficacy of ferroptosis-mediated cancer therapy.
This study investigates the influence of heating and cooling rate on liquefaction of lignocellulosic biomass in subH2O (subcritical water) or in scEtOH (supercritical ethanol), in dependency of final ...reaction temperatures (250–350 °C) and residence times (1–40 min). The heating rate has been identified as a crucial parameter in the subH2O-based liquefaction, whereas it has marginal influence in the scEtOH-based liquefaction. Detailed characterization of gas, liquid and solid products enables to identify the individual reaction steps, which results in a new insight into the reaction mechanisms, depending on the liquefaction solvents and conditions. Similar to fast pyrolysis, hydrothermal liquefaction consists of beneficial primary reactions (pyrolytic & hydrolytic degradation) and non-beneficial secondary reactions i.e. recombination and secondary cracking. In scEtOH, biomass was decomposed by pyrolysis and alcoholysis at relatively high reaction temperatures while the recombination of reaction intermediates are retarded by the unique reactions of scEtOH such as hydrogen donation and hydroxylalkylation.
•Fast heating rate enhances conversion and biocrude yield in subcritical water.•Heating rate has marginal effect on biocrude yield in supercritical ethanol.•In hydrothermal liquefaction, decomposition and recombination reactions compete.•Recombination reactions are retarded in supercritical ethanol-based liquefaction.
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•Ash-removal techniques were tested to enhance Na+ uptake capacity in hard carbon (HC).•Pre-acid treatment removed some hemicellulose and pectin fractions from raw cocoa pod husk ...(CPH).•HC from acid-treated CPH delivered 317mAhg−1 with ICE of 87%.
Biomass is a promising precursor for producing high-performance hard carbon as an anode for sodium-ion batteries (SIBs) because of its high low-voltage plateau capacity. However, the effect of residual ash in biomass on the electrochemical performance of hard carbons has rarely been investigated. This work describes an effective ash-removal approach as a critical step for preparing high-performance anodes for SIBs. A strong correlation between the ash removal techniques with structural and electrochemical properties of hard carbon was revealed. By examining various ash-removal techniques prior to carbonization and after carbonization using aqueous acid, neutral, and alkaline solutions, it was demonstrated that the removal of ash from raw cocoa pod husk (CPH) using aqueous acid and subsequent carbonization at 1300°C can produce hard carbon with high Na+ ion uptake in the low-voltage plateau region. During the acid pretreatment, ash and some hemicellulose fractions were removed, and carbonization of the acid-treated CPH resulted in hard carbon with a high degree of graphitization and reduced surface area. When tested as an anode in SIBs, the hard carbon produced from the acid-treated CPH exhibited an exceptionally high capacity of 317mAhg−1 and high plateau capacity of 244mAhg−1 at 0.05Ag−1, with a high initial Coulombic efficiency of 87%. At a high current density of 250mAg−1, a high capacity of 134mAhg−1 was maintained after 800 cycles. Post-treatment of hard carbon did not enhance the electrochemical performance. The physicochemical and electrochemical properties of hard carbons produced with the various pre- and post-treatment techniques were presented.
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