Anodization study of epitaxial graphene:insights on the oxygen evolution reaction of graphitic materials

The photoemission electron microscopy and x-ray photoemission spectroscopy were utilized for the study of anodized epitaxial graphene (EG) on silicon carbide as a fundamental aspect of the oxygen evolution reaction on graphitic materials. The high-resolution analysis of surface morphology and composition quantified the material transformation during the anodization. We investigated the surface with lateral resolution amp;lt;150 nm, revealing significant transformations on the EG and the role of multilayer edges in increasing the film capacitance.Funding Agencies| [EP/K035746/1]; [EP/M000605/1]</p

Digitalization of the construction industry of the Republic of Belarus as a major factor of growth of its competitiveness

Приведены направления и перспективы использования цифровых технологий в строительной отрасли, занимающей значимое место в структуре экономики Республики Беларусь на современном этапе развития. Цифровизация в строительной отрасли является драйвером инновационных преобразований, ускоряя внедрение технологических инноваций и сокращая длительность инновационного процесса. Основной акцент сделан на обобщение данных и систематизацию основных направлений применения цифровых технологий в строительной отрасли.The article presents the directions and prospects of using digital technologies in the construction industry, which occupies a significant place in the structure of the economy of the Republic of Belarus at the present stage of development. Digitalization in the construction industry is a driver of innovative transformations, accelerating the introduction of technological innovations and reducing the duration of the innovation process. The main emphasis is placed on the synthesis of data and systematization of the main areas of application of digital technologies in the construction industry

Peculiarities of piRNA-mediated post-transcriptional silencing of Stellate repeats in testes of Drosophila melanogaster

Silencing of Stellate genes in Drosophila melanogaster testes is caused by antisense piRNAs produced as a result of transcription of homologous Suppressor of Stellate (Su(Ste)) repeats. Mechanism of piRNA-dependent Stellate repression remains poorly understood. Here, we show that deletion of Su(Ste) suppressors causes accumulation of spliced, but not nonspliced Stellate transcripts both in the nucleus and cytoplasm, revealing post-transcriptional degradation of Stellate RNA as the predominant mechanism of silencing. We found a significant amount of Su(Ste) piRNAs and piRNA-interacting protein Aubergine (Aub) in the nuclear fraction. Immunostaining of isolated nuclei revealed co-localization of a portion of cellular Aub with the nuclear lamina. We suggest that the piRNA–Aub complex is potentially able to perform Stellate silencing in the cell nucleus. Also, we revealed that the level of the Stellate protein in Su(Ste)-deficient testes is increased much more dramatically than the Stellate mRNA level. Similarly, Su(Ste) repeats deletion exerts an insignificant effect on mRNA abundance of the Ste-lacZ reporter, but causes a drastic increase of β-gal activity. In cell culture, exogenous Su(Ste) dsRNA dramatically decreases β-gal activity of hsp70-Ste-lacZ construct, but not its mRNA level. We suggest that piRNAs, similarly to siRNAs, degrade only unmasked transcripts, which are accessible for translation

Repeat-associated siRNAs cause chromatin silencing of retrotransposons in the Drosophila melanogaster germline

Silencing of genomic repeats, including transposable elements, in Drosophila melanogaster is mediated by repeat-associated short interfering RNAs (rasiRNAs) interacting with proteins of the Piwi subfamily. rasiRNA-based silencing is thought to be mechanistically distinct from both the RNA interference and microRNA pathways. We show that the amount of rasiRNAs of a wide range of retroelements is drastically reduced in ovaries and testes of flies carrying a mutation in the spn-E gene. To address the mechanism of rasiRNA-dependent silencing of retrotransposons, we monitored their chromatin state in ovaries and somatic tissues. This revealed that the spn-E mutation causes chromatin opening of retroelements in ovaries, resulting in an increase in histone H3 K4 dimethylation and a decrease in histone H3 K9 di/trimethylation. The strongest chromatin changes have been detected for telomeric HeT-A elements that correlates with the most dramatic increase of their transcript level, compared to other mobile elements. The spn-E mutation also causes depletion of HP1 content in the chromatin of transposable elements, especially along HeT-A arrays. We also show that mutations in the genes controlling the rasiRNA pathway cause no derepression of the same retrotransposons in somatic tissues. Our results provide evidence that germinal Piwi-associated short RNAs induce chromatin modifications of their targets

Electrochemical Deposition of Copper on Epitaxial Graphene

Understanding the mechanism of metal electrodeposition on graphene as the simplest building block of all graphitic materials is important for electrocatalysis and the creation of metal contacts in electronics. The present work investigates copper electrodeposition onto epitaxial graphene on 4H-SiC by experimental and computational techniques. The two subsequent single-electron transfer steps were coherently quantified by electrochemistry and density functional theory (DFT). The kinetic measurements revealed the instantaneous nucleation mechanism of copper (Cu) electrodeposition, controlled by the convergent diffusion of reactant to the limited number of nucleation sites. Cu can freely migrate across the electrode surface. These findings provide fundamental insights into the nature of copper reduction and nucleation mechanisms and can be used as a starting point for performing more sophisticated investigations and developing real applications.Funding Agencies|Swedish Foundation for Strategic research (SSF)Swedish Foundation for Strategic Research [GMT14-0077, RMA15-024]; Angpanneforeningens Forskningsstiftelse [16-541]; VR grant [2018-04962]</p

Can Hybrid Na-Air Batteries Outperform Nonaqueous Na-O-2 Batteries?

In recent years, there has been an upsurge in the study of novel and alternative energy storage devices beyond lithium-based systems due to the exponential increase in price of lithium. Sodium (Na) metal-based batteries can be a possible alternative to lithium-based batteries due to the similar electrochemical voltage of Na and Li together with the thousand times higher natural abundance of Na compared to Li. Though two different kinds of Na-O-2 batteries have been studied specifically based on electrolytes until now, very recently, a hybrid Na-air cell has shown distinctive advantage over nonaqueous cell systems. Hybrid Na-air batteries provide a fundamental advantage due to the formation of highly soluble discharge product (sodium hydroxide) which leads to low overpotentials for charge and discharge processes, high electrical energy efficiency, and good cyclic stability. Herein, the current status and challenges associated with hybrid Na-air batteries are reported. Also, a brief description of nonaqueous Na-O-2 batteries and its close competition with hybrid Na-air batteries are provided.Funding Agencies|Swedish Government Strategic Research Area in Materials Science on Functional Materials at Linkoping University (Faculty Grant SFO-Mat-LiU) [2009-00971]</p

Insights into the Electrochemical Behavior of Mercury on Graphene/SiC Electrodes

Fast and real time detection of Mercury (Hg) in aqueous solutions is a great challenge due to its bio-accumulative character and the detrimental effect on human health of this toxic element. Therefore, development of reliable sensing platforms is highly desirable. Current research is aiming at deep understanding of the electrochemical response of epitaxial graphene to Mercury exposure. By performing cyclic voltammetry and chronoamperometry measurements as well as density functional theory calculations, we elucidate the nature of Hg-involved oxidation-reduction reactions at the graphene electrode and shed light on the early stages of Hg electrodeposition. The obtained critical information of Hg behavior will be helpful for the design and processing of novel graphene-based sensors.Funding Agencies|Swedish Foundation for Strategic research (SSF)Swedish Foundation for Strategic Research [GMT14-0077, RMA15-024]; Angpanneforeningens Forskningsstiftelse [16-541]; [2018-04962]</p

Correspondence on "Can Nanoimpacts Detect Single-Enzyme Activity? Theoretical Considerations and an Experimental Study of Catalase Impacts"

n/