Hybrid FeNiOOH/α‐Fe2O3/Graphene Photoelectrodes with Advanced Water Oxidation Performance

In this study, the photoelectrochemical behavior of electrodeposited FeNiOOH/Fe₂O₃/graphene nanohybrid electrodes is investigated, which has precisely controlled structure and composition. The photoelectrode assembly is designed in a bioinspired manner where each component has its own function: Fe₂O₃ is responsible for the absorption of light, the graphene framework for proper charge carrier transport, while the FeNiOOH overlayer for facile water oxidation. The effect of each component on the photoelectrochemical behavior is studied by linear sweep photovoltammetry, incident photon‐to‐charge carrier conversion efficiency measurements, and long‐term photoelectrolysis. 2.6 times higher photocurrents are obtained for the best‐performing FeNiOOH/Fe₂O₃/graphene system compared to its pristine Fe₂O₃ counterpart. Transient absorption spectroscopy measurements reveal an increased hole‐lifetime in the case of the Fe₂O₃/graphene samples. Long‐term photoelectrolysis measurements in combination with Raman spectroscopy, however, prove that the underlying nanocarbon framework is corroded by the photogenerated holes. This issue is tackled by the electrodeposition of a thin FeNiOOH overlayer, which rapidly accepts the photogenerated holes from Fe₂O₃, thus eliminating the pathway leading to the corrosion of graphene.     

Spin-Wave Optics in YIG Realized by Ion-Beam Irradiation

Direct focused-ion-beam writing is presented as an enabling technology for realizing functional spin-wave devices of high complexity, and demonstrate its potential by optically-inspired designs. It is shown that ion-beam irradiation changes the characteristics of yttrium iron garnet films on a submicron scale in a highly controlled way, allowing one to engineer the magnonic index of refraction adapted to desired applications. This technique does not physically remove material, and allows rapid fabrication of high-quality architectures of modified magnetization in magnonic media with minimal edge damage (compared to more common removal techniques such as etching or milling). By experimentally showing magnonic versions of a number of optical devices (lenses, gratings, Fourier-domain processors) this technology is envisioned as the gateway to building magnonic computing devices that rival their optical counterparts in their complexity and computational power.     

A New Data Layout Scheme for Energy-Efficient MapReduce Processing Tasks

Yet Another Resource Negotiator (YARN) is a framework to manage and allocate resource requests from applications that process big data stored in HDFS. However, dynamic power management methods are not efficient when YARN manage applications to process big data stored in the default data layout of HDFS. In this paper, we propose a new data layout scheme that can be implemented for HDFS. A comparison between our proposal and the existing HDFS data layout scheme shows that the new data layout algorithm significantly reduces the energy consumption at the slight expense of the mean response time of jobs.     

Antimicrobial functionalization of Ca alginate-coconut oil latent heat storing microcapsules by Ag nanoparticles

Latent heat storage by phase change materials (PCM) is a promising way of thermal energy storage for equilibrating the daily fluctuation of temperature in office- and home buildings. Bio-originated compounds have got great importance to evade further plastic contamination all over the world. Durability of biodegradable natural materials by means of environmentally friendly agents is an exciting challenge. In this study Ca alginate-coconut oil eco-friendly core-shell PCM microcapsules were functionalized with Ag nanoparticles, following their synthesis using harmless reducing agents. Throughout the preparation of the PCM microcapsules by repeated interfacial coacervation/crosslinking procedure, the Ag nanoparticles were homogeneously dispersed in the Ca alginate shell. High coconut oil content was achieved in the Ag nanoparticle-loaded microcapsules, which was not influenced by the Ag nanoparticle content. The high PCM content resulted in correspondingly high latent heat storing capability. The freezing and melting heat storing capacities were in the range of 83.6 and 85.6 J/g, as well as 89.7 to 92.6 J/g, respectively, matching to the extremely high PCM content in the range of 82.7% to 84.8% (m/m). Leaking of the heat storing microcapsules was not observed after 200 heating-cooling cycles. The Ag nanoparticle content did not influence the PCM ratio of the microcapsules, although as expected their antimicrobial potential was significantly enhanced by it. The highest Ag nanoparticle loading, that was 1.3% (m/m) related to the total mass of microcapsules, exerted excellent antibacterial and antifungal impact.     

Origin of Increased Solvent Accessibility of Peptide Bonds in Mutual Synergetic Folding Proteins

Mutual Synergetic Folding (MSF) proteins belong to a recently discovered class of proteins. These proteins are disordered in their monomeric but ordered in their oligomeric forms. Their amino acid composition is more similar to globular proteins than to disordered ones. Our preceding work shed light on important structural aspects of the structural organization of these proteins, but the background of this behavior is still unknown. We suggest that solvent accessibility is an important factor, especially solvent accessibility of the peptide bonds can be accounted for this phenomenon. The side chains of the amino acids which form a peptide bond have a high local contribution to the shielding of the peptide bond from the solvent. During the oligomerization step, other non-local residues contribute to the shielding. We investigated these local and non-local effects of shielding based on Shannon information entropy calculations. We found that MSF and globular homodimeric proteins have different local contributions resulting from different amino acid pair frequencies. Their non-local distribution is also different because of distinctive inter-subunit contacts.     

NMNAT1 Is a Survival Factor in Actinomycin D-Induced Osteosarcoma Cell Death

Osteosarcoma is a frequent and extremely aggressive type of pediatric cancer. New therapeutic approaches are needed to improve the overall survival of osteosarcoma patients. Our previous results suggest that NMNAT1, a key enzyme in nuclear NAD⁺ synthesis, facilitates the survival of cisplatin-treated osteosarcoma cells. A high-throughput cytotoxicity screening was performed to identify novel pathways or compounds linked to the cancer-promoting role of NMNAT1. Nine compounds caused higher toxicity in the NMNAT1 KO U2OS cells compared to their wild type counterparts, and actinomycin D (ActD) was the most potent. ActD-treatment of NMNAT1 KO cells increased caspase activity and secondary necrosis. The reduced NAD⁺ content in NMNAT1 KO cells was further decreased by ActD, which partially inhibited NAD⁺-dependent enzymes, including the DNA nick sensor enzyme PARP1 and the NAD⁺-dependent deacetylase SIRT1. Impaired PARP1 activity increased DNA damage in ActD-treated NMNAT1 knockout cells, while SIRT1 impairment increased acetylation of the p53 protein, causing the upregulation of pro-apoptotic proteins (NOXA, BAX). Proliferation was decreased through both PARP- and SIRT-dependent pathways. On the one hand, PARP inhibitors sensitized wild type but not NMNAT1 KO cells to ActD-induced anti-clonogenic effects; on the other hand, over-acetylated p53 induced the expression of the anti-proliferative p21 protein leading to cell cycle arrest. Based on our results, NMNAT1 acts as a survival factor in ActD-treated osteosarcoma cells. By inhibiting both PARP1- and SIRT1-dependent cellular pathways, NMNAT1 inhibition can be a promising new tool in osteosarcoma chemotherapy.     

Biodiesel production using enzymatic transesterification - Current state and perspectives

Biodiesel has attracted considerable interest in recent years as an alternative, biodegradable and nonpolluting transportation fuel. Conventional alkaline process for biodiesel production are energy-consuming and generate undesirable by-products such as soaps, that make difficult the separation and purification of biodiesel.Particular attention has been dedicated to the use of lipases as biocatalysts for biodiesel production due to their favorable conversion rate obtained in gentle conditions and relatively simple downstream processing steps for the purification of biodiesel and by-products. However, comparatively to conventional chemical processes, the major obstacles for enzymatic production of biodiesel remain the cost of lipases, the relatively slower reaction rate and lipases inactivation caused by methanol and glycerol.This review evaluates the current status and perspectives for enzymatic biodiesel production and indicates the key operational variables that influence lipase activity and stability together with the technological solutions for industrial implementation of enzymatic process.     

Cyanide-bridged bimetallic multidimensional structures derived from organotin(IV) and dicyanoaurate building blocks: ion exchange, luminescence, and gas sorption properties

The recent success of using methyltin(IV) cations in constructing multidimensional structures containing the Au–CN–Sn link with interesting physical properties will be surveyed. The methyltin(IV)-dicyanoaurates, Me₃Sn[Au(CN)₂] (1) and Me₂Sn[Au(CN)₂]₂ (2) containing the Au–CN–Sn link can be easily prepared by aqueous reaction of Me₃SnCl or Me₂SnCl₂ with stoichiometric amounts of an aqueous solution of K[Au(CN)₂]. The room temperature solid-state emission spectrum of 1 excited at 254 nm shows two intense emission bands at 442 and 670 nm, and a shoulder at 390 nm. When excited at 320 nm, the crystalline sample shows two intense emission bands at 442 and 720 nm, and a shoulder at 380 nm. After 2 min of grinding, only the blue emission band at 442 nm is observed. In contrast, the emission spectrum of 2 shows only one emission maximum at 422 nm. The porosity of 1 and 2 was probed by gas sorption measurements performed at 77 K. 1 exhibited no detectable microporosity as revealed by the inspection of the N₂, H₂, as well as, O₂ isotherms. The gas adsorption studies reveal that only a small amount of N₂ and H₂ (3.82 and 4.66 cm³ g⁻¹, respectively) is adsorbed by the framework of 2 at 77 K. However, a CO uptake of 11.20 cm³ g⁻¹ can be reached at 1 atm. The framework of 2 can take up significant amounts of O₂ (23.27 cm³ g⁻¹). In addition to intriguing photoluminescence and gas sorption behavior, these complexes also exhibit ion exchange properties in the presence of bivalent transition metal cations, such as cobalt(II), nickel(II), copper(II), and zinc(II).