Synergistic, Additive and Antagonistic Interactions of Grapes' Phenolic Compounds and Organic Acids.

The antioxidant interactions between several natural phenolic and non-phenolic compounds (catechin, quercetin, rutin, resveratrol, gallic acid and ascorbic acid) and organic acids (tartaric, citric and dihydroxyfumaric acids) have been investigated through the DPPH method. Main additive and antagonistic interactions have been found for the combinations of catechin, quercetin, resveratrol and gallic acid with tartaric and citric acids; such behavoir can be due to the enhanced stability of the phenolic compounds in the acidic media. Rutin and ascorbic acid demonstrated good synergistic effects with tartaric and citric organic acids, which may rely on the polymerization processes for rutin, and change of the mechanism of action in case of ascorbic acid.

Raman scattering and spectroscopic ellipsometry studies of SbS and SbSe bulk polycrystals.

Antimony sulfide (SbS) and antimony selenide (SbSe) compounds have attracted considerable attention for applications in different optoelectronic devices due to their notable optical and electrical properties, and due to the strong anisotropy of these properties along different crystallographic directions. However, the efficient use of these promising compounds still requires significant efforts in characterization of their fundamental properties. In the present study, Raman scattering and spectroscopic ellipsometry were used to investigate the vibrational and optical properties of SbSe and SbS bulk polycrystals grown by the modified Bridgman method.

Insights on aerosol properties using two decades-long ground-based remote sensing datasets in Moldova, Eastern Europe.

Aerosol optical properties were studied over Chisinau in Moldova, one of the longest running AERONET sites in Eastern Europe. During two decades (September 1999-November 2018), the mean aerosol optical depth (AOD) and Angstrom exponent (AE) were observed as 0.21 ± 0.

Mesoporous Materials for Metal-Laden Wastewater Treatment.

Rapid technological, industrial and agricultural development has resulted in the release of large volumes of pollutants, including metal ions, into the environment. Heavy metals have become of great concern due to their toxicity, persistence, and adverse effects caused to the environment and population. In this regard, municipal and industrial effluents should be thoroughly treated before being discharged into natural water or used for irrigation.

Modeling of the Charge-Transfer-Induced Spin Transition in the Tetranuclear Cyanide-Bridged [CoFe] Complex.

The course of the charge-transfer-induced spin transition demonstrated by the cyanide-bridged tetranuclear [CoFe(bpy*)(CN)(tp*)](PF)·2CP·8BN complex has been followed by DFT calculations of the single-point energies for different total spin values of the complex in a wide temperature range. With the aid of these calculations, the picture of spin conversion, that the compound undergoes, has been restored. It has been demonstrated that at 100 K the two crystallographically unique tetranuclear FeCo subunits A and B present in the structure contain diamagnetic low-spin Fe and low-spin Co ions.

Magnetization reversal through an antiferromagnetic state.

Magnetization reversal in ferro- and ferrimagnets is a well-known archetype of non-equilibrium processes, where the volume fractions of the oppositely magnetized domains vary and perfectly compensate each other at the coercive magnetic field. Here, we report on a fundamentally new pathway for magnetization reversal that is mediated by an antiferromagnetic state. Consequently, an atomic-scale compensation of the magnetization is realized at the coercive field, instead of the mesoscopic or macroscopic domain cancellation in canonical reversal processes.

Preparation, Chemical Composition, and Optical Properties of (-GaO Composite Thin Films)/(GaSSe Lamellar Solid Solutions) Nanostructures.

GaSSe solid solutions are layered semiconductors with a band gap between 2.0 and 2.6 eV.

Effects of Plasma Treatment on the Surface and Photocatalytic Properties of Nanostructured SnO-SiO Films.

In this work, we study the effects of treating nanostructured SnO-SiO films derived by a sol-gel method with nitrogen and oxygen plasma. The structural and chemical properties of the films are closely investigated. To quantify surface site activity in the films following treatment, we employed a photocatalytic UV degradation test with brilliant green.

Synthesis, Characterization and Cytotoxic Evaluation of New Pyrrolo[1,2-]pyridazines Obtained via Mesoionic Oxazolo-Pyridazinones.

New pyrrolo[1,2-]pyridazines were synthesized by 3 + 2 cycloaddition reaction between mesoionic oxazolo-pyridazinones and methyl/ethyl propiolate. The mesoionic compounds were generated in situ by action of acetic anhydride on 3(2)pyridazinone acids obtained from corresponding esters by alkaline hydrolysis followed by acidification. The structures of the compounds were confirmed by elemental analyses and IR, H-NMR, C-NMR, and X-ray diffraction data.

Local colonisations and extinctions of European birds are poorly explained by changes in climate suitability.

Climate change has been associated with both latitudinal and elevational shifts in species' ranges. The extent, however, to which climate change has driven recent range shifts alongside other putative drivers remains uncertain. Here, we use the changing distributions of 378 European breeding bird species over 30 years to explore the putative drivers of recent range dynamics, considering the effects of climate, land cover, other environmental variables, and species' traits on the probability of local colonisation and extinction.

Topological Avenue for Efficient Decontamination of Large Volumes of Fluids via UVC Irradiation of Packed Metamaterials.

Nowadays, metamaterials application enjoys notoriety in fluid decontamination and pathogen annihilation, which are frequently present in polluted fluids (e.g., water, blood, blood plasma, air or other gases).

Broadband magnetic resonance spectroscopy in MnSc[Formula: see text]S[Formula: see text].

Recent neutron scattering experiments suggested that frustrated magnetic interactions give rise to antiferromagnetic spiral and fractional skyrmion lattice phases in MnSc[Formula: see text]S[Formula: see text] . Here, to trace the signatures of these modulated phases, we studied the spin excitations of MnSc[Formula: see text]S[Formula: see text] by THz spectroscopy at 300 mK and in magnetic fields up to 12 T and by broadband microwave spectroscopy at various temperatures up to 50 GHz. We found a single magnetic resonance with frequency linearly increasing in field.

Spinodal decomposition introduces strain-enhanced thermochromism in polycrystalline VTiO thin films.

Processes of self-organization play a key role in the development of innovative functional nanocomposites, allowing, in particular, the transformation of metastable solid solutions into multilayers by activating spinodal decomposition instead of layer-by-layer film growth. We report the formation of strained layered (V,Ti)O nanocomposites in thin polycrystalline films using a spinodal decomposition. Already during the growth of VTiO films, spinodal decomposition was detected while producing atomic-scale disordered V- and Ti-rich phases.

On parametric representation of the Newton's aerodynamic problem.

Newton's problem of finding the surface shape of a rotation body based on the condition of minimal resistance of the body when it moves in a rarefied medium is discussed. The problem is formulated in the form of a classical isoperimetric problem in calculus of variations. The exact solution is given in the class of piecewise differentiable functions.

Paper-Based Humidity Sensors as Promising Flexible Devices, State of the Art, Part 2: Humidity-Sensor Performances.

This review article covers all types of paper-based humidity sensor, such as capacitive, resistive, impedance, fiber-optic, mass-sensitive, microwave, and RFID (radio-frequency identification) humidity sensors. The parameters of these sensors and the materials involved in their research and development, such as carbon nanotubes, graphene, semiconductors, and polymers, are comprehensively detailed, with a special focus on the advantages/disadvantages from an application perspective. Numerous technological/design approaches to the optimization of the performances of the sensors are considered, along with some non-conventional approaches.

Novel Antioxidants Based on Selected 3d Metal Coordination Compounds with 2-Hydroxybenzaldehyde 4,S-Diallylisothiosemicarbazone.

2-Hydroxybenzaldehyde 4,S-diallylisothiosemicarbazone (HL) was synthesized and characterized by 1H, 13C NMR and FTIR spectroscopies. It exists in solution in two isomeric forms: cis (~25%) and trans (~75%). Six stable complexes were obtained by interaction of HL with copper(II), nickel(II), cobalt(III) and iron(III) salts: [Cu(L)Cl] (1), [Cu(L)NO3] (2), [Cu(3,4-Lut)(L)NO3] (3), [Ni(L)OAc] (4), [Co(L)2]Cl (5), [Fe(L)2]NO3 (6).

Paper-Based Humidity Sensors as Promising Flexible Devices: State of the Art: Part 1. General Consideration.

In the first part of the review article "General considerations" we give information about conventional flexible platforms and consider the advantages and disadvantages of paper when used in humidity sensors, both as a substrate and as a humidity-sensitive material. This consideration shows that paper, especially nanopaper, is a very promising material for the development of low-cost flexible humidity sensors suitable for a wide range of applications. Various humidity-sensitive materials suitable for use in paper-based sensors are analyzed and the humidity-sensitive characteristics of paper and other humidity-sensitive materials are compared.

Application of Titanium Carbide MXenes in Chemiresistive Gas Sensors.

The titanium carbide MXenes currently attract an extreme amount of interest from the material science community due to their promising functional properties arising from the two-dimensionality of these layered structures. In particular, the interaction between MXene and gaseous molecules, even at the physisorption level, yields a substantial shift in electrical parameters, which makes it possible to design gas sensors working at RT as a prerequisite to low-powered detection units. Herein, we consider to review such sensors, primarily based on TiCT and TiCT crystals as the most studied ones to date, delivering a chemiresistive type of signal.

Rattling-induced suppression of thermal transport in cubic InOwith Sn-Ga diatomic defect.

We present the first principles study of cubic InOwith a diatomic defect composed of a Sn atom substituting the In atom at the-site and a Ga atom embedded in the nearest-site (structural vacancy) with lattice positions according to the Wyckoff notations. Structural, electronic, phononic and thermal properties were investigated within density functional theory formalism. The lattice anharmonicity effects were taken into account for all possible three-phonon scattering processes.

Current Trends in Nanomaterials for Metal Oxide-Based Conductometric Gas Sensors: Advantages and Limitations-Part 2: Porous 2D Nanomaterials.

This article discusses the features of the synthesis and application of porous two-dimensional nanomaterials in developing conductometric gas sensors based on metal oxides. It is concluded that using porous 2D nanomaterials and 3D structures based on them is a promising approach to improving the parameters of gas sensors, such as sensitivity and the rate of response. The limitations that may arise when using 2D structures in gas sensors intended for the sensor market are considered.

New magneto-polaron resonances in a monolayer of a transition metal dichalcogenide.

Transition metal dichalcogenide (TMD) semiconductors are two-dimensional materials with great potential for the future of nano-optics and nano-optoelectronics as well as the rich and exciting development of basic research. The influence of an external magnetic field on a TMD monolayer raises a new question: to unveil the behavior of the magneto-polaron resonances (MPRs) associated with the phonon symmetry inherent in the system. It is shown that the renormalized Landau energy levels are modified by the interplay of the long-range Pekar-Fröhlich (PF) and short-range deformation potential (DP) interactions.

Introducing N-Heteroaromatic Bases into Copper(II) Thiosemicarbazon Complexes: A Way to Change their Biological Activity.

Three new copper(II) complexes, [Cu(1,10-Phen)(L)] (1), [Cu(2,2'-Bpy)(L)] (2) and [Cu(3,4-Lut)(L)] (3), where H L=2-[(2,4-dihydroxyphenyl)methylidene]-N-(prop-2-en-1-yl)hydrazine-1-carbothioamide, 1,10-Phen=1,10-phenanthroline, 2,2'-Bpy=2,2'-bipyridine, 3,4-Lut=3,4-lutidine, have been synthesized and characterized by elemental analysis, FTIR spectroscopy and single crystal X-ray crystallography (1, 2). All compounds are mononuclear. The introduction of a monodentate N-heteroaromatic base (3,4-dimethylpyridine) has led to a significant increase of antimicrobial activity against Gram-negative Escherichia coli and antifungal activity against Candida albicans compared to the pro-ligand and the precursor complex [Cu(L)H O].

Photophysics of tetracarboxy-zinc phthalocyanine photosensitizers.

Zinc-tetracarboxy-phthalocyanine (ZnPc(COOH)) was synthesized by a melting method and basic hydrolysis. A ZnPc(COOH)/FeO/Ch composite was prepared by immobilization of ZnPc(COOH) onto FeO/chitosan nanoparticles by a simple immersion method. The photophysical properties were studied using UV-vis spectrophotometry, fluorescence spectroscopy and time-correlated single photon counting (TCSPC) in different aqueous solutions.

UVC radiation intensity dependence of pathogen decontamination rate: semiclassical theory and experiment.

A semiclassical (light classical and molecule quantum) model describing the dependence of DNA/RNA dimerization rate as function of the ultraviolet C (UVC) radiation's intensity is proposed. Particularly, a nonlinear model is developed based on the Raman-like processes in quantum optics. The main result of the theory shows that the process of dimerization in the DNA/RNA depends strongly on the UVC light's intensity, thus proving a possible quantum microscopical mechanism of the interaction of UV light with the DNA.

Topological transitions in ac/dc-driven superconductor nanotubes.

Extending of nanostructures into the third dimension has become a major research avenue in condensed-matter physics, because of geometry- and topology-induced phenomena. In this regard, superconductor 3D nanoarchitectures feature magnetic field inhomogeneity, non-trivial topology of Meissner currents and complex dynamics of topological defects. Here, we investigate theoretically topological transitions in the dynamics of vortices and slips of the phase of the order parameter in open superconductor nanotubes under a modulated transport current.