Verification of the chemical subsystem of the regional climate model RegCM-CHEM4

New simulation results, obtained from the chemical version of the regional climate model RegCMCHEM4, are presented for Siberian region. The verification of the chemical subsystem of the model with non-hydrostatic dynamical core is carried out using the atmospheric chemical transfer scheme CBMZ (Carbon Bond Mechanism-Z). To define chemical emissions the global RCP (Representative Concentration Pathways) emission dataset prepared by the International Institute for Applied Systems Analysis (IIASA), is used. For gas phase species, we have prepared the 6 hourly chemical boundary conditions from our modified version of the Model for Ozone and Related chemical Tracers, version 4 (MOZART-4). Quantitative estimates of methane emission in the atmosphere of the Siberian region have been obtained.

Optimized extraction method enables quantitative analysis of surface metabolite recovery for exposomics and behavioral studies

Workplace chemical exposures are a major source of occupational injury. Although over half of these are skin exposures, exposomics research often focuses on chemical levels in the air or in worker biofluids such as blood and urine. Until now, one limitation has been the lack of methods to quantitatively measure surface chemical transfer. Outside the realm of harmful chemicals, the small molecules we leave behind on surfaces can also reveal important aspects of human behavior. In this study, we developed a swab-based quantitative approach to determine small molecule concentrations across common surfaces. We demonstrate its utility using one drug, cyclobenzaprine, and two human-derived metabolites, carnitine and phenylacetylglutamine, on four common surfaces: linoleum flooring, plastified laboratory workbench, metal and Plexiglass. This approach enabled linear small molecule recovery and quantification of molecule abundance on workplace built environment surfaces. Overall, this method paves the way for future quantitative exposomics studies.

Tackling the toxics in plastics packaging

The widespread use of plastic packaging for storing, transporting, and conveniently preparing or serving foodstuffs is significantly contributing to the global plastic pollution crisis. This has led to many efforts directed toward amending plastic packaging’s end of life, such as recycling, or alternative material approaches, like increasingly using paper for food packaging. But these approaches often neglect the critical issue of chemical migration: When contacting foodstuffs, chemicals that are present in packaging transfer into food and thus unwittingly become part of the human diet. Hazardous chemicals, such as endocrine disrupters, carcinogens, or substances that bioaccumulate, are collectively referred to as “chemicals of concern.” They can transfer from plastic packaging into food, together with other unknown or toxicologically uncharacterized chemicals. This chemical transfer is scientifically undisputed and makes plastic packaging a known, and avoidable, source of human exposure to synthetic, hazardous, and untested chemicals. Here, I discuss this issue and highlight aspects in need of improvement, namely the way that chemicals present in food packaging are assessed for toxicity. Further, I provide an outlook on how chemical contamination from food packaging could be addressed in the future. Robust innovations must attempt systemic change and tackle the issue of plastic pollution and chemical migration in a way that integrates all existing knowledge.

Characterizing the spatial distribution of dipeptides in rodent tissue using MALDI MS imaging with on-tissue derivatization

Combining a laser-assisted chemical transfer technique and hexafluoroisopropanol provides a highly effective on-tissue derivatization method for MALDI MS imaging of the spatial distribution of dipeptides.

Spontaneous membrane-less multi-compartmentalization via aqueous two-phase separation in complex coacervate micro-droplets

Multiphase coacervate droplets produced by internalised aqueous two-phase separation are used for the spatially dependent chemical transfer of sugar molecules.

Black silicon – correlation between microstructure and Raman scattering

Black silicon layers were formed on silicon substrate by the surface structure chemical transfer method and by anodic etching method. Properties of microstructure of formed layers were experimentally studied by the electron microscopy methods (TEM) and characterized by statistical, Fourier and multifractal methods. Theoretical structures with defined fractal properties and surface roughness were generated and their microstructure properties were evaluated. Obtained results were used for the explanation of the real structure development during the forming procedure. By using of this approach, we study the correlation of roughness and fractality with optical properties. Black silicon layers were also investigated by using of Raman scattering method. Optimized theoretical model describing the 1st order of black Si Raman scattering profile was constructed and used for evaluation of the biaxial tensile stress introduced during etching procedure.

Clay minerals related to the late magmatic activity of the Piton des Neiges (Réunion Island): consequence for the primitive crusts

ABSTRACTThis paper describes a detailed petrographic and isotopic study of hypabyssal sheets of quartz-syenite that represent the ultimate differentiation product of the oceanite alkaline magmatic reservoir of the Piton des Neiges stratovolcano (Réunion Island). Clay minerals of the corrensite to chlorite series crystallized during the late-magmatic activity, with quartz, carbonates and accessory minerals from juvenile fluids filling the primary porosity of the quartz-syenite. It is proposed that a double chemical transfer occurred at the end of the crystallization process: degassing of the exsolved CO2-rich and SiO2-rich fluid from the magmatic chamber through the porous quartz-syenite and diffusion of Al, Fe and Mg from the intruded basalts affected by the juvenile fluids towards the primary porosity of the quartz-syenite, feeding the crystallization of late-magmatic clays in the residual primary pores after quartz and carbonate deposition. This process may be generalized to alkaline plutonism, as well as to the primitive crusts of terrestrial planets, and may be the first source of clays in early planets.