Structural Studies Research Articles

An fMRI study of phrase structure and subject island violations.

In principle, functional neuroimaging provides uniquely informative data in addressing linguistic questions, because it can indicate distinct processes that are not apparent from behavioral data alone. This could involve adjudicating the source of unacceptability via the different patterns of elicited brain responses to different ungrammatical sentence types. However, it is difficult to interpret brain activations to syntactic violations. Such responses could reflect processes that have nothing intrinsically related to linguistic representations, such as domain-general executive function abilities. In order to facilitate the potential use of functional neuroimaging methods to identify the source of different syntactic violations, we conducted an fMRI experiment to identify the brain activation maps associated with two distinct syntactic violation types: phrase structure (created by inverting the order of two adjacent words within a sentence) and subject islands (created by extracting a wh-phrase out of an embedded subject). The comparison of these violations to control sentences surprisingly showed no indication of a generalized violation response, with almost completely divergent activation patterns. Phrase structure violations seemingly activated regions previously implicated in verbal working memory and structural complexity in sentence processing, whereas the subject islands appeared to activate regions previously implicated in conceptual-semantic processing, broadly defined. We review our findings in the context of previous research on syntactic and semantic violations using event-related potentials. Although our results suggest potentially distinct underlying mechanisms underlying phrase structure and subject island violations, our results are tentative and suggest important methodological considerations for future research in this area.

Covalent modification of protein by chemical probe in living cells for structural and interaction studies.

Cellular activities are predominantly carried out by proteins that can dynamically adopt different structural conformations and differentially interact with other biomolecules according to cellular needs. Chemical probes are small molecules used to selectively interact and modulate the activities of specific proteins to study their functions such as the validation of potential drug targets. The remarkable performance of AlphaFold algorithms in the prediction of protein structures has pivoted interest toward elucidating the intracellular dynamics of protein structural conformation where covalent modification of proteins by chemical probes could be used to shed light upon. However, due to the barrier to entry by cell membrane and the general unfavorable reactive conditions of the intracellular environment, most studies using reactive chemical probes are still conducted on purified proteins and cell lysates. Nevertheless, recent progresses have been made in designing chemical probes with improved membrane permeability, stability and reactivity. This paper surveys the literature on recent advancements in membrane-permeable chemical probes and their applications with protein mass spectrometry for the intracellular studies of protein structural conformations and biomolecular interactions.

Anisotropic model observing pulsars from Neutron Star Interior Composition with modified Van der Waals equation of state

This paper is designed for heavy pulsars coming from the Neutron Star Interior Composition Explorer. The research model is describe by Einstein field equations for anisotropic fluid configuration with spherical symmetry. As per present perceptiveness, modified non-linear Van der Waals equation of state is used to relate physical variables. The continuity of inner and outer matter is obtained by comparing inner spacetime to outer Schwarzschild metric. The physical viability of this model is evaluated and further it is compared with observational data of pulsars PSR J0348+0432, PSR J0740+6620 and PSR J0030+0451. The model fulfils all physical and mathematical characteristics of the dense structure studies. It offers the factual proofs carried by evolution of celestial configurations. The working model presented here is physically viable and shows stable behaviour.

Synthesis, structural study, antimicrobial activity and theoretical treatment of Cr(III), Ni(II), Pt(IV) and Zn(II) complexes with 2-hydroxy-4-Nitro phenyl piperonalidene

The complexes of the 2-hydroxy-4-Nitro phenyl piperonalidene with metal ions Cr(III), Ni(II), Pt(IV) and Zn(II) were prepared in ethanolic solution. These complexes were characterized by spectroscopic methods, conductivity, metal analyses and magnetic moment measurements. The nature of the complexes formed in ethanolic solution was study following the molar ratio method. From the spectral studies, monomer structures proposed for the nickel (II) and Zinc (II) complexes while dimeric structures for the chromium (III) and platinum (IV) were proposed. Octahedral geometry was suggested for all prepared complexes except zinc (II) has tetrahedral geometry, Structural geometries of these compounds were also suggested in gas phase by using hyper chem-8 program for the molecular mechanics and semi-empirical calculations. The heat of formation and binding energy for the prepared compounds was calculated by using PM3 and AMBER methods. The method of PM3 was used for evaluate the vibration spectra for the imine and starting material as authentic compound. Preliminary in vitro tests for antibacterial and antifungal activity show that most of the prepared compounds display good activity to (Staphylococcus aureus), (Escherichia coli) and (Candida albicans).

The impact of fire source location on hot gas layer temperature in multi-compartment pre-flashover fires: Analysis and semi-empirical model development

A numerical study of a two-room structure (multi-compartment) subjected to fire in the inner room was carried out, employing the CFD (Computational Fluid Dynamics) software called FDS (Fire Dynamics Simulator), to (i) analyze the influence of the fire source position on the hot gas layer temperature, Tu, and its behavior in a multi-compartment fire, and (ii) develop a semi-empirical engineering calculation model to predict Tu in the adjacent room to a pre-flashover well-ventilated fire room, taking into account the fire source position. The results showed that when the fire origin occurs close to walls or elevated above the floor level, a reduced air entrainment is observed in the fire plume and flame, causing an increase in the Tu and a reduction of the smoke production in the fire room. This reduction in the smoke production led to a lower increase in the Tu of the adjacent room in relation to the case when the fire source was at the center of the fire room. It was also observed that the Tu in both rooms was inversely proportional to the ventilation factor (A.H0.5), with a significant increase observed as the ventilation factor decreases, depending on the fire source position. Furthermore, a semi-empirical engineering calculation model was developed to predict the Tu in the adjacent room, considering different fire source locations at ground level and elevated. The model was validated against experimental data from the literature, showing a good agreement (deviation of ≈20 %), thus demonstrating its applicability to other cases.

Improving Power Spectrum Estimation Using Multitapering: Efficient Asteroseismic Analyses for Understanding Stars, the Milky Way, and Beyond

Asteroseismic time series data have imprints of stellar oscillation modes, whose detection and characterization through time series analysis allows us to probe stellar interior physics. Such analyses usually occur in the Fourier domain by computing the Lomb–Scargle (LS) periodogram, an estimator of the power spectrum underlying unevenly sampled time series data. However, the LS periodogram suffers from the statistical problems of (1) inconsistency (or noise) and (2) bias due to high spectral leakage. Here, we develop a multitaper power spectrum estimator using the nonuniform fast Fourier transform (mtNUFFT) to tackle the inconsistency and bias problems of the LS periodogram. Using a simulated light curve, we show that the mtNUFFT power spectrum estimate of solar-like oscillations has lower variance and bias than the LS estimate. We also apply our method to the Kepler-91 red giant, and combine it with PBjam peakbagging to obtain mode parameters and a derived age estimate of 3.97 ± 0.52 Gyr. PBjam allows the improvement of age precision relative to the 4.27 ± 0.75 Gyr APOKASC-2 (uncorrected) estimate, whereas partnering mtNUFFT with PBjam speeds up peakbagging thrice as much as LS. This increase in efficiency has promising implications for Galactic archaeology, in addition to stellar structure and evolution studies. Our new method generally applies to time-domain astronomy and is implemented in the public Python package tapify, available at https://github.com/aaryapatil/tapify.

Optimization, characterization and biosafety of carotenoids produced from whey using Micrococcus luteus

This study aimed to optimize the production of carotenoid pigments from Micrococcus luteus (ATCC 9341) through the statistical screening of media components and the characterization of antimicrobial, antioxidant, cytogenetic and cytotoxic activities. A BOX-Behnken design was used to assess the effects of whey concentration, inoculum size, pH, temperature, and agitation speed on carotenoid yield. The optimum combination increased production to 2.19 g/L, with a productivity of 0.045 g L-1 h−1 and a productivity yield of 0.644 g/g, as confirmed by an observed carotene production of 2.19 g/L. The final response surface model fitting the data had an R2 of 0.9461. High-performance liquid chromatography (HPLC) analysis identified 12 carotenoid pigment compounds produced by M. luteus. The extracts displayed moderate antimicrobial efficacy against Gram-positive bacteria such as Bacillus cereus (ATCC 11778), Staphylococcus aureus (ATCC 6538), and E. faecalis (ATCC 19433), with inhibition zone diameters (IZD) of 29.0, 14.0, and 37.0 mm, respectively, at 1000 μg/mL. However, its effectiveness against Gram-negative bacteria is limited. In comparison, tetracycline exhibited greater antimicrobial potency. The IC50 value of carotenoids was used to indicate the antioxidant activity. IC50 value from the DPPH assay was 152.80 mg/100mL. An IC50 cytotoxicity value greater than 300 μg/mL was found against normal mouse liver cells, with over 68% cell viability even at 300 μg/mL, indicating low toxicity. Histological structure studies revealed normal myocardial muscle tissue, lung tissue, and kidney tissue sections, whereas liver tissue sections revealed ballooning degeneration of hepatocytes and disorganization of hepatic cords. Cytogenetic parameters revealed that the carotene treatment group had a mitotic index (70%) lower than that of the control but higher than that of the positive control, mitomycin, and did not substantially increase numerical (1.2%) or structural aberrations compared with those of the control, suggesting a lack of genotoxic effects under the experimental conditions. In conclusion, optimized culture conditions enhanced carotenoid yields from M. luteus, and the extracts displayed promising bioactivity as moderate antibiotics against certain gram-positive bacteria and as antioxidants. The high IC50 values demonstrate biosafety. Overall, this bioprocess for enhanced carotenoid production coupled with bioactivity profiling and low cytotoxicity support the application of M. luteus carotenoids.

Consolidated Curium Reprocessing Procedure Inspires Molecular Design for Sensitized Curium Circularly Polarized Luminescence.

Curium's stable redox chemistry and ability to emit strong metal-based luminescence make it uniquely suitable for spectroscopic studies among the actinide series. Targeted ligand and coordination compound design can support both fundamental electronic structure studies and industrial safeguards with the identification of unique spectroscopic signatures. However, limited availability, inherent radioactive hazards, and arduous purifications have long inhibited such investigations of this element. A consolidated reprocessing procedure for curium has been developed for the milligram scale. The recovery of not only standard legacy curium samples but also hazardous legacy perchlorate containing curium samples was achieved, culminating in column chromatography utilizing the extraction resin DGA (N,N,N',N'-tetra-2-ethylhexyldiglycolamide, branched). Surprisingly, controlled elution of the Cm band from the extraction resin was followed through bright pink luminescence triggered by an inexpensive hand-held UV-vis lamp (380-400 nm). This observation inspired the design of an enantiopure, C2-symmetrical ligand bearing a chiral (trans-1,2-diaminocyclohexane) backbone with achiral DGA moieties (N,N,N',N'-tetra-n-octylacetamide), that enabled rarely observed curium circularly polarized luminescence upon metal chelation. These combined achievements should unlock more luminescence and circularly polarized luminescence studies of curium, and enable the recovery of many curium and other trivalent actinide samples.

Synthesis and characterization of zinc-doped hematite nanoparticles for photocatalytic applications and their electronic structure studies by density functional theory

Hematite nanoparticles doped with 1, 3 and 5 % Zn (all % are in molar) were prepared using mechanical alloying. Morphological and phase structure studies using scanning electron microscopy and X-ray diffraction showed nanoparticles possessing a semi-spherical shape and particle size of <50 nm crystallized in rhombohedral structure. The lattice parameters of hematite increased upon Zn doping. The energy-dispersive X-ray and Fourier-transform infrared results demonstrated that Zn was successfully incorporated. The optical behavior of nanoparticles was examined by UV–Vis diffuse reflectance spectroscopy and revealed that Zn doping increased the absorption intensity in the visible light region and decreased the band gap from 1.95 (hematite) to 1.83 eV (3 % Zn). Methylene blue dye degradation by the 3 % Zn sample proved doubling of the photocatalytic activity due to electronic structure modification upon Zn doping. First principles studies using density functional theory performed to investigate the effect of Zn on the electronic band structure of hematite showed that Zn doping caused band gap reduction, causing formation of new energy states, mainly above the valence band. Eventually, the enhancement of Urbach energy and reduction of effective mass, respectively accountable for increasing the relaxation time and mobility of charge carriers, were considered the two main mechanisms regarding the increased photocatalytic behavior of hematite by Zn doping.

Structural studies and functional validation of Eugenol and Ferulic acid against Enterococcus faecalis Sortase A.

Enterococcus faecalis (E. faecalis) is commonly occurring pathogen associated with nosocomial infections. Infections are difficult to treat because of their multidrug-resistant (MDR) nature and their tendency to form biofilms. Therefore, it is essential to find alternative medicinal approaches of treatment. In this regard, targeting an important protein for drug development can be an alternative approach. Sortase A (SrtA) is an important enzyme involved in anchoring cell surface-exposed proteins to the cell envelope. SrtA is present in Gram-positive bacteria which catalyses the attachment of several virulence factors and other proteins to the cell membrane. It is involved in bacterial pathogenesis, therefore, it's a promising drug target for the development of anti-microbial drugs targeting cell adhesion, evasion, and biofilm development.To identify SrtA potential inhibitors, we havepurified E. faecalis Sortase A (EfSrtAΔN59). Structural studiesalong with molecular docking of protein with selected ligand molecules were done andconfirmed by MD simulation experiments. We have also performed functional validation of these compounds on bacterial growth, anti-biofilm assays and inhibition assay of selected ligands were also done against E. faecalis individually and in synergistic combinations. Results indicated that both Eugenol and Ferulic acid bind to EfSrtAΔN59 with significant interactions and show promising results.

Chemical assessment of three octahedral Ni(II) complexes with heterocyclic acylpyrazolone ligand: Crystal structure, DFT-NBO analysis, Hirshfeld and Magnetic study

We have synthesized three novel mononuclear Nickel(II) coordination complexes [Ni(DMBPTMP)2(EtOH)2], [Ni(PCBPMP)2(DMF)(H2O)] and [Ni(PCBPTMP)2(DMSO)2] with σ-donating acylpyarazolone ligands. All the complexes have been comprehensively characterized via FTIR, UV–Vis, TGA, and Magnetic study. Additionally, single crystal X-ray diffraction analysis was successfully used to characterize the three complexes. The findings showed that the geometry around Ni(II) is slightly distorted octahedral in [Ni(DMBPTMP)2(EtOH)2], [Ni(PCBPMP)2(DMF)(H2O)] complexes and also in the centrosymmetric [Ni(PCBPTMP)2(DMSO)2] complex. In all the complexes the metal is bischelated by two pyrazolone molecules via carbonyl and benzoyl carbonyl oxygen donors, but with a different configuration of ligands. In addition to the experimental studies and spectroscopic characteristics, DFT computational analysis and Natural bonding orbital (NBO) analysis have been performed using a B3LYP/LANL2DZ basis set for the optimization. All three Ni(II) complexes give three distinct absorption transitions which has been proved by Electronic spectral analysis. A paramagnetic nature of the complex is confirmed through magnetic study. Utilising Hirshfeld surface analysis, intermolecular interactions of complexes were evaluated.

Flavonoids as potential SARS-CoV-2 main protease inhibitors: In vitro activity evaluation, molecular docking, 3D-QSAR investigation and synthesis

The damage to public health posed by the COVID-19 epidemic remains non-negligible, and research into highly effective antiviral drugs is key to addressing the epidemic. The main protease (Mpro) is critical for SARS-CoV-2 replication and acts as an effective target for drug development. To date, many flavonoid compounds have been reported to exhibit inhibition of Mpro, and flavonoid structures are informative for the development of new inhibitors. In the present study, we first evaluated the ability of 35 flavonoid compounds to bind Mpro and found that the hydrophobic interaction generated between the benzene ring and the residues may be the main source of binding force. The in vitro inhibitory activity of these compounds was tested by the FRET method, and most of them showed significant inhibition of Mpro. Preliminary analysis revealed that the presence of the glycosidic group was detrimental to the activity of the compounds, in addition the position of the hydroxyl substituent had an effect on the activity of the compounds. Reliable and predictive CoMFA (q2 = 0.541, r2 = 0.998, SEE = 0.039) and CoMISA (q2 = 0.554, r2 = 0.999, SEE = 0.034) models were developed, and the compounds were analyzed by 3D-QSAR with modeled steric, electrostatic, hydrogen bond donor, and hydrophobic fields. A series of compounds were synthesized and characterized, which showed similar experimental and predicted activities, with the activity of 15d (IC50 = 0.74 ± 0.04 uM) exceeding that of the template molecule 15 (0.98 ± 0.13 uM). Subsequently, molecular docking revealed the binding mode of 15d to Mpro and verified the predictions of steric, hydrogen bond donor, and hydrophobic field. In conclusion, these findings provide ideas for subsequent structural studies of flavonoids that could be used in the development of flavonoid-type SARS-CoV-2 Mpro inhibitors.

Stable electrochemical properties of trace titanium doping layered P3-type K0.5Mn0.92Ti0.08O2 cathode material for potassium ion batteries

The wide application of potassium ion batteries (PIBs) urgently requires the development of ideal cathode materials with low cost, good reaction kinetics and structural stability. Here, a titanium-doped K0.5Mn0.92Ti0.08O2 cathode material for potassium ion batteries is developed by doping modification strategy using a high-temperature solid-state method. The structure and performance structure-activity relationship of binary K0.5Mn1-xTixO2 cathode materials doped with non-electrochemically active element Ti4+ are studied experimentally and theoretically. With the introduction of Ti4+, when the doping amount is <10 mol%, the doped solid solution is hexagonal P3 phase, and the transition metal layer spacing increases. The non-equivalent doping affects the relative content of Mn3+/Mn4+, smoothes the redox peak in the electrochemical process, reduces the doping formation energy, and improves the structural stability. The ex-situ XRD fine structure study of the electrochemical process shows that the structural change of the material during the discharge process is suppressed after doping. The best Ti-doped cathode material K0.5Mn0.92Ti0.08O2 has an initial discharge capacity of 126.9 mAh·g−1 at a current density of 20 mA·g−1, and the capacity retention rate is 53.7 % after 100 cycles. This work provides a feasible strategy for the construction of stable electrode materials for PIBs.

Unusually high oxidation states of manganese in high optical basicity silicate glasses

Unusually high oxidation states of manganese were stabilized within a cesium-barium silicate (CBS) glass system of extremely high optical basicity. The highest basicity was obtained for the metasilicate glass 40Cs2O–10BaO–50SiO2 (mol%) with an optical basicity of Λ = 0.81. The presence of Mn5+ (d2) as well as Mn6+ (d1) is confirmed by UV–Vis, photoluminescence, and Raman spectroscopy. The UV–Vis spectrum is dominated by the Mn3+ (d4) absorption at 526 nm for low-basicity glasses, which is replaced by a peak at 679 nm (Mn5+) and, finally, a band at 603 nm (Mn6+) in the glass with the highest basicity (Λ = 0.81). In this glass, the Mn5+/Mn6+ ratio varies with the melting conditions. Photoluminescence (PL) spectroscopy under 633 nm excitation confirms the presence of Mn5+, showing the narrow, forbidden 1E →3A2 transition located at 1191 nm with vibrational sidebands at 1245 nm and 1290 nm. The measured static fluorescence intensity due to Mn5+ grows exponentially with increasing optical basicity. The near infrared fluorescence decay was bi-exponential, with time constants of 14 and 51 μs. The absence of Mn4+ in CBS glasses was confirmed by PL and electron paramagnetic resonance (EPR) spectroscopy. Despite initial doping as MnO2, metastable Mn4+ disproportionates into lower and higher valent manganese species, followed by reduction or oxidation of manganese to a stable species as ruled by the basicity of the glass and oxygen availability during melting. A structural study of the glasses by Raman spectroscopy revealed a resonance enhancement effect for the symmetric stretching mode of MnO4-tetrahedra at ∼800 cm−1 with overtones observed at higher frequencies.

Synthesis, structural studies and Hirshfeld surface analysis of the substituted isoindole-1,3‑dione derivatives

In this study, we have performed the ring-opening reaction of 5-benzyl/ethyl-2-hydroxyhexahydro-4H-oxireno[2,3-e] isoindole-4,6(5H)‑dione (10) with HBr to the corresponding bromodiols, regioselectively. Structures of the synthesized compounds are elucidated through spectral methods (1H NMR,13C NMR and HRMS) Afterwards, the racemic products 11a-b were purified and the absolute geometries of 5‑bromo-2-ethyl-4,6-dihydroxyhexahydro-1H-isoindole 1,3(2H)‑dione (11a) and 2-benzyl-5‑bromo-4,6-dihydroxyhexahydro-1H-isoindole-1,3(2H)‑dione (11b) was determined by X-ray diffraction analysis. Effective O−H∙∙∙O (2.738–2.874 Å) hydrogen bonds between diol and ketone units are important interactions between the molecules. Hirshfeld surface analyses of the compounds (11a-b) have provided further insights into molecular, crystal structure and intermolecular interactions. The results indicated that the most important contributions for the crystal packings are from H∙∙∙H, O∙∙∙H/H∙∙∙O, C∙∙∙H/H∙∙∙C and Br∙∙∙H/H∙∙∙Br interactions. Finally, energy frameworks were analyzed to a better understanding of the packing of crystal structure and the supramolecular rearrangements for the structures (11a-b).

Negotiating pricing and payment terms for insurance covered mHealth apps: a qualitative content analysis and taxonomy development based on a German experience

BackgroundGermany was the first country worldwide to offer mobile digital health applications (mHealth apps, “DiGA”) on prescription with full cost coverage by statutory health insurances. Especially statutory health insurances criticize the current pricing and payment regulations in Germany due to “free and non-transparent” pricing in the first year and lack of cost use evidence. The study consists of two parts: The first part evaluates interests of digital health application providers and statutory health insurances in Germany to identify overlaps and divergences of interests. The second part includes the development of a comprehensive pricing and payment taxonomy for reimbursable mHealth apps in general.MethodsBoth parts of the study used the input from 16 expert interviews with representatives of digital health application providers and statutory health insurances in Germany. In part one the authors conducted a qualitative content analysis and in part two they followed the taxonomy development process according to Nickerson et al. (2013).ResultsA value based care model is expected to bring the greatest benefit for patients while statutory health insurances welcome the idea of usage based pricing. The final pricing and payment taxonomy consists of four design and negotiation steps (price finding, payment prerequisites, payment modalities, composition of negotiation board).ConclusionsAs healthcare resources are scarce and thus need to be optimally allocated, it is important to implement pricing and payment terms for reimbursable mHealth apps that result in the greatest benefit for patients. To the best of the authors’ knowledge, there has been no structured study yet that examines alternative pricing strategies for reimbursable mHealth apps.The developed pricing and payment taxonomy for reimbursable mHealth apps serves as planning and decision basis for developers, health policy makers and payers internationally.

Dinuclear zinc(II) acetate complexes derived from N,N',S-tridentate Schiff bases: synthesis, structural study and Hirshfeld surface analysis.

Three dinuclear zinc(II) acetate complexes of the general formula [Zn{Ln}(AcO)]2, namely, di-μ-acetato-κ4O:O'-bis[({2-[(pyridin-2-ylmethylidene)amino]phenyl}sulfanido-κ3N,N',S)zinc(II)], [Zn2(C12H9N2S)2(C2H3O2)2] (n= 1), 4, μ-acetato-1:2κ2O:O'-acetato-2κO-[μ-(2-{[1-(pyridin-2-yl)ethylidene]amino}phenyl)sulfanido-1κS:2κ3N,N',S][(2-{[1-(pyridin-2-yl)ethylidene]amino}phenyl)sulfanido-1κ3N,N',S]dizinc(II), [Zn2(C13H11N2S)2(C2H3O2)2] (n= 2), 5, and μ-acetato-1:2κ2O:O'-acetato-2κO-[μ-(2-{[phenyl(pyridin-2-yl)methylidene]amino}phenyl)sulfanido-1κS:2κ3N,N',S][(2-{[phenyl(pyridin-2-yl)methylidene]amino}phenyl)sulfanido-1κ3N,N',S]dizinc(II)-bis(2-aminophenyl) disulfide (2/1), [Zn2(C18H13N2S)2(C2H3O2)2]·0.5C12H12N2S2 (n= 3), 6·0.5(2-APS)2, were obtained from the reaction of 2-R-(pyridin-2-yl)benzothiazoline precursors (R= H, 1; R= Me, 2; R= Ph, 3) with zinc acetate dihydrate in a 1:1 ratio. All the complexes crystallized as dinuclear species and complex 6 cocrystallized with one molecule of bis(2-aminophenyl) disulfide (2-APS)2. The anionic Schiff base ligands {Ln}- displayed a κ2N,κS-tridentate coordination mode with the formation of two five-membered chelate rings. In 4, 5 and 6·0.5(2-APS)2, both ZnII ions are pentacoordinated and the coordination sphere of 4 was different with respect to those in 5 and 6·0.5(2-APS)2. For 4, the X-ray diffraction study showed a dinuclear complex containing two bridging acetate ligands linked to both ZnII ions. For 5 and 6·0.5(2-APS)2, the dinuclear complexes displayed one bridging acetate ligand linked to both ZnII ions, where the first ZnII ion includes a dative bond with one S atom from an adjacent anionic Schiff base {Ln}-, while the second ZnII ion is coordinated to one terminal acetate ligand. In each dinuclear complex, the geometry is the same for both ZnII metal centres. The local geometry of the ZnII cation in 4 is halfway between trigonal bipyramidal and square pyramidal local geometries; in 5 and 6, the local geometries are described as distorted square pyramidal. Hirshfeld surface analysis of 5 and 6 showed the predominance of H...H interactions, as well as the contribution of C-H...C, C-H...O and C-H...S noncovalent interactions to the cohesion of the crystalline network of the ZnII complexes.

Hydrogeological conditions of the Meshchera depression and their connection with the latest tectonic structure of the region

The article presents the results of a study of the geological structure, recent tectonics and hydrogeological conditions of the central part of the Meshchera depression, located on the border of the Moscow, Ryazan and Vladimir regions. The detailed characterization of the newest structure of the Klepikovsky trough made it possible to identify young growing uplifts that influence the structure and morphology of the trough. The reasons for the intense swampiness of the territory and the change in the orientation of the trough from meridional to latitudinal are determined. The studies carried out proved the influence of the latest tectonics of the trough on the hydrogeological conditions of the territory. It has been established that areas of groundwater recharge and discharge can be localized within the Klepikovsky trough.

Structural, dielectric, and electrical studies of Sm-doped Sr0.95Ba0.05Bi2Nb2O9 lead-free relaxor ceramics

Structural, dielectric, and electrical studies of Sm-doped Sr0.95Ba0.05Bi2Nb2O9 lead-free relaxor ceramics

Magnetron sputtered Zn-Ta2O5 thin films for electronic, thermoelectric, and optical applications

In the current study, the optical and electronic properties of Zn-Ta2O5 have been investigated as a potential optoelectronic material. Theoretically, the density functional theory was employed to pure and Zn doped Ta2O5 compositions using the Wien2k code. For experimental investigations uniform thin films were fabricated by magnetron co-sputtering technique on the silicon substrate. The optical, thermoelectric, electronic, and morphological properties were studied by relating the outcomes of simulations and experimental results providing the correlation among the findings. Graphs of the total density of states and partial density of states revealed the hybridization between the dopant and host orbitals. The p-d hybridization of O and Ta atoms was shown by the density of states. Structural studies reveal the growth of primary phase identified as orthorhombic Ta2O5. The grain growth of the Zn-Ta2O5 thin films gradually increase as the Zn content was increased and led to more compact film formation. Zn incorporation improves the thermal transport properties by increasing the Seebeck coefficient and reducing thermal conductivity. Band gap values were reduced by increasing the Zn concentration and recorded value was observed as 3.07 eV for Ta2O5 and 1.77 eV for maximum zinc concentration. Optical characteristics are measured in relation to photon energy which shows enhancement by the Zn doping. The outcomes of the current study manifest that these materials provide great potential for thermoelectric and optoelectronic applications.