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Achieving ultranarrow absorption linewidths in the condensed phase enables optical state preparation of specific non-thermal states, a prerequisite for quantum-enabled technologies. The 4f orbitals of lanthanide(iii) complexes are often referred to as atom-like, reflecting their isolated nature, and are promising substrates for the optical preparation of specific quantum states. To better understand the photophysical properties of 4f states and assess their potential for quantum applications, theoretical building blocks are required for rapid screening. In this study, an atomic-level perturbative calculation (i.e., spin-orbit crystal field, SOCF) is applied to various Yb(iii) complexes to investigate their linear absorption and emission through a fitting mechanism of their experimentally determined transition energies and oscillator strengths. In particular, the optical properties of (thiolfan)YbCl(THF) (thiolfan = 1,1-bis(2,4-di-tert-butyl-6-thiomethylenephenoxy)ferrocene), a recently reported complex with an ultranarrow optical linewidth, are computed and compared to those of other Yb(iii) compounds. Through a transition energy sampling study, major contributors to the optical linewidth are identified. We observe particularly isolated f-f transitions and narrow linewidths, which we attribute to two distinct factors. Firstly, the ultra-high atomic similarity of the orbitals involved in the optical transition, along with the presence of an anisotropic crystal field, collectively contribute to the observed narrow transitions. Secondly, we note highly correlated excited-ground energy fluctuations that serve to greatly suppress inhomogeneous line-broadening. This article illustrates how SOCF can be used as a low-cost method to probe the influence of crystal field environment on the optical properties of Yb(iii) complexes to assist the development of novel lanthanide series quantum materials.

To unravel why computational design fails in creating viable enzymes, while directed evolution (DE) succeeds, our research delves into the laboratory evolution of protoglobin. DE has adapted this protein to efficiently catalyze carbene transfer reactions. We show that the previously proposed enhanced substrate access and binding alone cannot account for increased yields during DE. The 3D electric field in the entire active site is tracked through protein dynamics, clustered using the affinity propagation algorithm, and subjected to principal component analysis. This analysis reveals notable changes in the electric field with DE, where distinct field topologies influence transition state energetics and mechanism. A chemically meaningful field component emerges and takes the lead during DE and facilitates crossing the barrier to carbene transfer. Our findings underscore intrinsic electric field dynamic's influence on enzyme function, the ability of the field to switch mechanisms within the same protein, and the crucial role of the field in enzyme design.

The dynamic restructuring of Cu has been observed under electrochemical conditions, and it has been hypothesized to underlie the unique reactivity of Cu toward CO2 electroreduction. Roughening is one of the key surface phenomena for Cu activation, whereby numerous atomic vacancies and adatoms form. However, the atomic structure of such surface motifs in the presence of relevant adsorbates has remained elusive. Here, we explore the chemical space of Cu surface restructuring under coverage of CO and H in realistic electroreduction conditions, by combining grand canonical DFT and global optimization techniques, from which we construct a potential-dependent grand canonical ensemble representation. The regime of intermediate and mixed CO and H coverage─where structures exhibit some elevated surface Cu─is thermodynamically unfavorable yet kinetically inevitable. Therefore, we develop a quasi-kinetic Monte Carlo simulation to track the system's evolution during a simulated cathodic scan. We reveal the evolution path of the system across coverage space and identify the accessible metastable structures formed along the way. Chemical bonding analysis is performed on the metastable structures with elevated Cu*CO species to understand their formation mechanism. By molecular dynamics simulations and free energy calculations, the surface chemistry of the Cu*CO species is explored, and we identify plausible mechanisms via which the Cu*CO species may diffuse or dimerize. This work provides rich atomistic insights into the phenomenon of surface roughening and the structure of involved species. It also features generalizable methods to explore the chemical space of restructuring surfaces with mixed adsorbates and their nonequilibrium evolution.

PurposeTriple-negative breast cancer (TNBC) often metastasizes to the central nervous system (CNS) and has the highest propensity among breast cancer subtypes to develop leptomeningeal disease (LMD). LMD is a spread of cancer into leptomeningeal space that speeds up the disease progression and severely aggravates the prognosis. LMD has limited treatment options. We sought to test whether the common anti-helminthic drug mebendazole (MBZ) may be effective against murine TNBC LMD.MethodsA small-molecule screen involving TNBC cell lines identified benzimidazoles as potential therapeutic agents for further study. In vitro migration assays were used to evaluate cell migration capacity and the effect of MBZ. For in vivo testing, CNS metastasis was introduced into BALB/c athymic nude mice through internal carotid artery injections of brain-tropic MDA-MB-231-BR or MCF7-BR cells. Tumor growth and spread was monitored by bioluminescence imaging and immunohistochemistry. MBZ was given orally at 50 and 100 mg/kg doses. MBZ bioavailability was assayed by mass spectrometry.ResultsBioinformatic analysis and migration assays revealed higher migratory capacity of TNBC compared to other breast cancer subtypes. MBZ effectively slowed down migration of TNBC cell line MDA-MB-231 and its brain tropic derivative MDA-MB-231-BR. In animal studies, MBZ reduced leptomeningeal spread, and extended survival in brain metastasis model produced by MDA-MB-231-BR cells. MBZ did not have an effect in the non-migratory MCF7-BR model.ConclusionsWe demonstrated that MBZ is a safe and effective oral agent in an animal model of TNBC CNS metastasis. Our findings are concordant with previous efforts involving MBZ and CNS pathology and support the drug's potential utility to slow down leptomeningeal spread.

Though YB6 and LaB6 share the same crystal structure, atomic valence electron configuration, and phonon modes, they exhibit drastically different phonon-mediated superconductivity. YB6 superconducts below 8.4 K, giving it the second-highest critical temperature of known borides, second only to MgB2. LaB6 does not superconduct until near-absolute zero temperatures (below 0.45 K), however. Though previous studies have quantified the canonical superconductivity descriptors of YB6's greater Fermi-level (Ef) density of states and higher electron-phonon coupling (EPC), the root of this difference has not been assessed with full detail of the electronic structure. Through chemical bonding, we determine low-lying, unoccupied 4f atomic orbitals in lanthanum to be the key difference between these superconductors. These orbitals, which are not accessible in YB6, hybridize with π B-B bonds and bring this π-system lower in energy than the σ B-B bonds otherwise at Ef. This inversion of bands is crucial: the optical phonon modes we show responsible for superconductivity cause the σ-orbitals of YB6 to change drastically in overlap, but couple weakly to the π-orbitals of LaB6. These phonons in YB6 even access a crossing of electronic states, indicating strong EPC. No such crossing in LaB6 is observed. Finally, a supercell (the M k-point) is shown to undergo Peierls-like effects in YB6, introducing additional EPC from both softened acoustic phonons and the same electron-coupled optical modes as in the unit cell. Overall, we find that LaB6 and YB6 have fundamentally different mechanisms of superconductivity, despite their otherwise near-identity.

Nontrivial surface states in topological materials have emerged as exciting targets for surface chemistry research. In particular, topological insulators have been used as electrodes in electrocatalytic reactions. Herein, we investigate the robustness of the topological surface states and band topology under electrochemical conditions, specifically in the presence of an electric double layer. First-principles band structure calculations are performed on the electrified (111) surfaces of Bi2Te3, Bi2Se3, and Sb2Te3 using an implicit electrolyte model. Our results demonstrate the adiabatic evolution of the surface states upon surface charging. Under oxidizing potentials, the surface states are shifted upward in energy, preserving the Dirac point on the surface and the band inversion in the bulk. Conversely, under reduced potentials, hybridization is observed between the surface and bulk states, suggesting a likely breakdown of topological protection. The position of the Fermi level, which dictates the working states in catalytic reactions, should ideally be confined within the bulk bandgap. This requirement defines a potential window for the effective application of topological electrocatalysis.

The fundamental understanding of sluggish hydrogen evolution reaction (HER) kinetics on a platinum (Pt) surface in alkaline media is a topic of considerable debate. Herein, we combine cyclic voltammetry (CV) and electrical transport spectroscopy (ETS) approaches to probe the Pt surface at different pH values and develop molecular-level insights into the pH-dependent HER kinetics in alkaline media. The change in HER Tafel slope from ∼110 mV/decade in pH 7-10 to ∼53 mV/decade in pH 11-13 suggests considerably enhanced kinetics at higher pH. The ETS studies reveal a similar pH-dependent switch in the ETS conductance signal at around pH 10, suggesting a notable change of surface adsorbates. Fixed-potential calculations and chemical bonding analysis suggest that this switch is attributed to a change in interfacial water orientation, shifting from primarily an O-down configuration below pH 10 to a H-down configuration above pH 10. This reorientation weakens the O-H bond in the interfacial water molecules and modifies the reaction pathway, leading to considerably accelerated HER kinetics at higher pH. Our integrated studies provide an unprecedented molecular-level understanding of the nontrivial pH-dependent HER kinetics in alkaline media.

The Hydra nervous system is the paradigm of a simple nerve net. Nerve cells in Hydra, as in many cnidarian polyps, are organized in a nerve net extending throughout the body column. This nerve net is required for control of spontaneous behavior: elimination of nerve cells leads to polyps that do not move and are incapable of capturing and ingesting prey (Campbell, 1976). We have re-examined the structure of the Hydra nerve net by immunostaining fixed polyps with a novel antibody that stains all nerve cells in Hydra. Confocal imaging shows that there are two distinct nerve nets, one in the ectoderm and one in the endoderm, with the unexpected absence of nerve cells in the endoderm of the tentacles. The nerve nets in the ectoderm and endoderm do not contact each other. High-resolution TEM (transmission electron microscopy) and serial block face SEM (scanning electron microscopy) show that the nerve nets consist of bundles of parallel overlapping neurites. Results from transgenic lines show that neurite bundles include different neural circuits and hence that neurites in bundles require circuit-specific recognition. Nerve cell-specific innexins indicate that gap junctions can provide this specificity. The occurrence of bundles of neurites supports a model for continuous growth and differentiation of the nerve net by lateral addition of new nerve cells to the existing net. This model was confirmed by tracking newly differentiated nerve cells.

In acidic conditions, the electroreduction of CO or CO2 (noted CO(2)RR) on metal surfaces is conventionally hindered by intense competition with the hydrogen evolution reaction (HER). In this study, we present first-principles calculations of a mechanism wherein the formation of H-induced Cu adatoms on Cu(111) serves as a pivotal trigger for CORR in acidic environments. Through an analysis of the grand canonical surface state population, we elucidate that these newly formed adatoms create an array of active sites essential for both CO adsorption and subsequent reduction. Our ensemble-based kinetic models unveil the role of adatoms, enhancing the HER while simultaneously initiating CORR. Notably, the cumulative activity of the HER and CORR is contingent upon the combination of various surface states, with their individual contributions varying based on the electrode potential and pH. The interplay between surface state dynamics and electrochemical activity sheds new light on the potential-dependent nature of the active site and reaction kinetics governing CORR on Cu(111) in acidic media.

Polyatomic molecules equipped with optical cycling centers (OCCs), enabling continuous photon scattering during optical excitation, are exciting candidates for advancing quantum information science. However, as these molecules grow in size and complexity, the interplay of complex vibronic couplings on optical cycling becomes a critical but relatively unexplored consideration. Here, we present an extensive exploration of Fermi resonances in large-scale OCC-containing molecules using high-resolution dispersed laser-induced fluorescence and excitation spectroscopy. These resonances manifest as vibrational coupling leading to intensity borrowing by combination bands near optically active harmonic bands, which require additional repumping lasers for effective optical cycling. To mitigate these effects, we explore altering the vibrational energy level spacing through substitutions on the phenyl ring or changes in the OCC itself. While the complete elimination of vibrational coupling in complex molecules remains challenging, our findings highlight significant mitigation possibilities, opening new avenues for optimizing optical cycling in large polyatomic molecules.

Alloys of tungsten tetraboride (WB4) with the addition of C and Si were prepared by arc-melting of the constituent elements. The phase purity was established by powder X-ray diffraction (PXRD) and surface morphology by scanning electron microscopy (SEM) analysis. Vickers hardness measurements showed hardness enhancement for alloys with a nominal composition of (W0.98Si0.02):11.6B and (W0.95C0.05):11.6B of 52.2 ± 3.0 and 50.5 ± 2.5 GPa, respectively, compared to 41.2 ± 1.4 GPa for pure WB4. (W0.92Zr0.08):11.6B was determined in previous work to have a hardness of 55.9 ± 2.8 GPa. Bulk moduli were calculated following analysis of high-pressure radial diffraction data and were determined to be 329 ± 4 (K0′ = 2) and 390 ± 9 (K0′ = 0.6) GPa for 8 atom % Zr and 5 atom % C-doping, respectively, compared to 326-339 GPa for pure WB4. Computational analysis was used to determine the dopant positions in the crystal structure, and it was found that Zr primarily substitutes W in the 2c position, Si substitutes for the entire B3 trimers, and C inserts in the Bhex-layer. The hardness enhancement in the case of Zr-doping is attributed primarily to extrinsic hardness effects (nanograin morphology), in the case of C─to intrinsic effects (interlayer bond strengthening), and in the intermediate case of Si─to both intrinsic and extrinsic effects (bond strengthening and fine surface morphology).

Bonding interactions and spin-orbit coupling in the topological insulator SrAg4 Sb2 are investigated using DFT with orbital projection analysis. Ag-Ag delta bonding is a key ingredient in the topological insulating state because the 4dxy+4dx2-y2${4d_{xy} + 4d_{x^2 - y^2 } }$ delta antibonding band forms a band inversion with the 5 s sigma bonding band. Spin-orbit coupling is required to lift d orbital degeneracies and lower the antibonding band enough to create the band inversion. These bonding effects are enabled by a longer-than-covalent Ag-Ag distance in the crystal lattice, which might be a structural characteristic of other transition metal based topological insulators. A simplified model of the topological bands is constructed to capture the essence of the topological insulating state in a way that may be engineered in other materials.

The growing concern over the escalating levels of anthropogenic CO2 emissions necessitates effective strategies for its conversion to valuable chemicals and fuels. In this research, we embark on a comprehensive investigation of the nature of zirconia on a copper inverse catalyst under the conditions of CO2 hydrogenation to methanol. We employ density functional theory calculations in combination with the Grand Canonical Basin Hopping method, enabling an exploration of the free energy surface including a variable amount of adsorbates within the relevant reaction conditions. Our focus centers on a model three-atom Zr cluster on a Cu(111) surface decorated with various OH, O, and formate ligands, noted Zr3Ox (OH)y (HCOO)z/Cu(111), revealing major changes in the active site induced by various reaction parameters such as the gas pressure, temperature, conversion levels, and CO2/H2 feed ratios. Through our analysis, we have unveiled insights into the dynamic behavior of the catalyst. Specifically, under reaction conditions, we observe a large number of composition and structures with similar free energy for the catalyst, with respect to changing the type, number, and binding sites of adsorbates, suggesting that the active site should be regarded as a statistical ensemble of diverse structures that interconvert.

Abstract Background Chronic Kidney Disease (CKD) is characterized by a methionine-related metabolic disorder involving reduced plasma levels of hydrogen sulfide (H2S) and increased lanthionine. The gut microbiota influences methionine metabolism, potentially impacting sulfur metabolite dysfunctions in CKD. We evaluated whether gut microbiota dysbiosis contributes to H2S and lanthionine metabolic alterations in CKD. Methods The gut microbiota of 88 CKD patients (non-dialysis, hemodialysis, and transplant patients) and 26 healthy controls were profiled using 16 S-amplicon sequencing. H2S and lanthionine concentrations were measured in serum and fecal samples using the methylene blue method and LC-MS/MS, respectively. Results The CKD population exhibited a tenfold increase in serum lanthionine associated with kidney dysfunction. Despite lanthionine retention, hemodialysis and transplant patients had significantly lower serum H2S than healthy controls. Fecal H2S levels were not altered or related to bloodstream H2S concentrations. Conversely, fecal lanthionine was significantly increased in CKD compared to healthy controls and associated with kidney dysfunction. Microbiota composition varied among CKD groups and healthy controls, with the greatest dissimilarity observed between hemodialysis and transplant patients. Changes relative to the healthy group included uneven Ruminococcus gnavus distribution (higher in transplant patients and lower in non-dialysis CKD patients), reduced abundance of the short-chain fatty acid-producing bacteria Alistipes indistinctus and Coprococcus eutactus among transplant patients, and depleted Streptococcus salivarius in non-dialysis CKD patients. A higher abundance of Methanobrevibacter smithii, Christensenella minuta, and Negativibacillus massiliensis differentiated hemodialysis patients from controls. No correlation was found between differentially abundant species and the metabolic profile that could account for the H2S and lanthionine alterations observed. Conclusions The metabolic deregulation of H2S and lanthionine observed in the study was not associated with alterations in the gut microbiota composition in CKD patients. Further research on microbial sulfur pathways may provide a better understanding of the role of gut microbiota in maintaining H2S and lanthionine homeostasis.

Shipbuilding is a typical strategic industry and, due to its high importance, is known as a complex one. The authors, based on foreign primary sources, for the first time in Russian scientific literature explore the path that the shipbuilding industry of the PRC has taken from “emergence from nothing” to the position in the largest shipbuilding country in the world, i.e. five main stages of development. The article describes the key steps taken towards the formation of the industry, both at the level of the creation of ministries and departments, and at the level of the emergence and development of scientific centers. The important government documents related to maintaining and stimulating the development of shipbuilding are studied in sufficient detail. The authors analyze the achievements and weaknesses of the modern Chinese shipbuilding industry. It is shown how China gradually rose to a leading position in the world shipbuilding from stage to stage, and what efforts were made by the state along this path.

The article is dedicated to the reasons and process of choosing a company name in Xiaomi Corporation, whicn can be translated as “A small grain of rice”. Unlike many Chinese companies, Xiaomi Corporation’s choice of name was associated not only with a marketing move that would allow the company to successfully enter the international market and stand out from other brands, but also with the desire to demonstrate “its history”, which, by using certain symbols, would reflect such significant aspects of Chinese culture as respect for traditions, connection with historical memory, etc. The experience of Xiaomi Corporation shows how strongly traditions and history can influence modern ideas about the creation and development of a brand.

Hexagonal boron nitride (hBN) is a highly selective catalyst for the oxidative dehydrogenation of propane (ODHP) to propylene. Using a variety of ex situ characterization techniques, the activity of the catalyst has been attributed to the formation of an amorphous boron oxyhydroxide surface layer. The ODHP reaction mechanism proceeds via a combination of surface mediated and gas phase propagated radical reactions with the relative importance of both depending on the surface-to-void-volume ratio. Here we demonstrate the unique capability of operando X-ray Raman spectroscopy (XRS) to investigate the oxyfunctionalization of the catalyst under reaction conditions (1 mm outer diameter reactor, 500 to 550 °C, P = 30 kPa C3H8, 15 kPa O2, 56 kPa He). We probe the effect of a water cofeed on the surface of the activated catalyst and find that water removes boron oxyhydroxide from the surface, resulting in a lower reaction rate when the surface reaction dominates and an enhanced reaction rate when the gas phase contribution dominates. Computational description of the surface transformations at an atomic-level combined with high precision XRS spectra simulations with the OCEAN code rationalize the experimental observations. This work establishes XRS as a powerful technique for the investigation of light element-containing catalysts under working conditions.

Enzymes are versatile and efficient biological catalysts that drive numerous cellular processes, motivating the development of enzyme design approaches to tailor catalysts for diverse applications. In this perspective, we investigate the unique properties of natural, evolved, and designed enzymes, recognizing their strengths and shortcomings. We highlight the challenges and limitations of current enzyme design protocols, with a particular focus on their limited consideration of long-range electrostatic and dynamic effects. We then delve deeper into the impact of the protein environment on enzyme catalysis and explore the roles of preorganized electric fields, second coordination sphere interactions, and protein dynamics for enzyme function. Furthermore, we present several case studies illustrating successful enzyme-design efforts incorporating enzyme strategies mentioned above to achieve improved catalytic properties. Finally, we envision the future of enzyme design research, spotlighting the challenges yet to be overcome and the synergy of intrinsic electric fields, second coordination sphere interactions, and conformational dynamics to push the state-of-the-art boundaries.

How does a single amino acid mutation occurring in the blinding disease, Lebers hereditary optic neuropathy (LHON), impair electron shuttling in mitochondria? We investigated changes induced by the m.3460 G>A mutation in mitochondrial protein ND1 using the tools of Molecular Dynamics and Free Energy Perturbation simulations, with the goal of determining the mechanism by which this mutation affects mitochondrial function. A recent analysis suggested that the mutations replacement of alanine A52 with a threonine perturbs the stability of a region where binding of the electron shuttling protein, Coenzyme Q10, occurs. We found two functionally opposing changes involving the role of Coenzyme Q10. The first showed that quantum electron transfer from the terminal Fe/S complex, N2, to the Coenzyme Q10 headgroup, docked in its binding pocket, is enhanced. However, this positive adjustment is overshadowed by our finding that the mobility of Coenzyme Q10 in its oxidized and reduced states, entering and exiting its binding pocket, is disrupted by the mutation in a manner that leads to conditions promoting the generation of reactive oxygen species. An increase in reactive oxygen species caused by the LHON mutation has been proposed to be responsible for this optic neuropathy.

Increasing evidence suggests that the gut microbiota, through the “microbiota–gut–brain axis”, can regulate anxiety, mood, and cognitive abilities such as memory and learning processes. Consistently with this, treatments altering the gut microbiota, such as antibiotics and probiotics, may influence brain function and impact behavior. The mechanisms that underlie the interplay between the intestinal microbiota and the brain have been intensively studied. We aimed to investigate the effects of two probiotic lactobacilli strains, Lacticaseibacillus rhamnosus 12L and Lactiplantibacillus plantarum 8PA3, on behavioral disorders in mice induced by a two-week parenteral treatment with broad-spectrum antibiotics. On completion of the treatment, the mice were subjected to behavioral tests, including the open field test (OFT), novel object recognition test (ORT), and T-maze test. Antibiotic-treated mice demonstrated anxiety-related behavior, decreased cognition, and retarded exploratory activity that were ameliorated by the administration of probiotics. As was determined by high-performance liquid chromatography (HPLC), both tested strains produced serotonin and its metabolite 5-hydroxyindoleacetic acid (5-HIAA), as well as dopamine, which was further metabolized into norepinephrine by L. plantarum 8PA3 and epinephrine by L. rhamnosus 12L. Moreover, these lactobacilli were found to harbor catecholamines and 3,4-dihydroxyphenylacetic acid (DOPAC) in their biomass when grown on MRS broth. Additionally, L. plantarum 8PA3 and L. rhamnosus 12L were able to impact oxidative stress via H2O2 production and antioxidant activity, as determined in this study by the ferrous oxidation–xylenol orange (FOX) assay and the 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging assay, respectively. The results obtained in this study support the role of probiotics as a promising therapeutic for neurological disorders. However, more investigations are required to confirm the clinical significance of this finding.

Nanoscale oxides grown in c-silicon, implanted with low-energy (2 keV) H+ ions and fluences ranging from 1013 cm−2 to 1015 cm−2 by RF plasma immersion implantation (PII), have been investigated. The oxidation of the implanted Si layers proceeded in dry O2 at temperatures of 700 °C, 750 °C and 800 °C. The optical characterization of the formed Si/SiOx structures was conducted by electroreflectance (ER) and spectroscopic ellipsometric (SE) measurements. From the ER and SE spectra analysis, the characteristic energy bands of direct electron transitions in Si are elaborated. The stress in dependence on hydrogenation conditions is considered and related to the energy shifts of the Si interband transitions around 3.4 eV. Silicon oxides, grown on PII Si at a low H+ fluence, have a non-stoichiometric nature, as revealed by IR-SE spectra analysis, while with an increasing H+ fluence in the PII Si substrates and/or the subsequent oxidation temperature the stoichiometric Si-O4 units in the oxides become predominant. The development of surface morphology is studied by atomic force microscopy (AFM) imaging. Oxidation of the H+-implanted Si surface region flattens out the surface pits created on the Si surface by H+ implants. Based on the evaluation of the texture index and mean fractal dimension, the isotropic and self-similar character of the studied surfaces is emphasized.

Introduction: Iron deficiency is a common feature in athletes, and optimizing iron levels may become a contributing factor to improved athletic performance. Purpose: This study aimed to evaluate body iron stores and their relationship with sports performance. It also sought correlations between the swimmers’ hematological, hormonal, anthropometric, and functional status and their sports achievements. Methodology: The research involved 19 athletes (11 women and 8 men) from the Bulgarian national swimming team. They were tested for maximal aerobic capacity on a cycle ergometer and had blood samples taken to determine iron status and hematological and hormonal markers. Their swimming achievements (Swimming points) were evaluated as a percentage of the world records in the respective discipline. Results: There were statistically significant differences between the female and male swimmers for Unbound Iron Binding Capacity (UIBC) and ferritin. A higher UIBC in women indicated lower iron levels in them. Among female swimmers, five had ferritin levels below 40 ng/mL. In women, a highly reliable correlation between the Swimming points and ferritin concentration (r = .68) was observed. All male swimmers had ferritin values above 40 ng/mL, and there was no reliable correlation between ferritin concentration and Swimming points, probably because ferritin was in the optimal range and is no longer a significant performance factor. Conclusions: In swimmers, the optimal serum ferritin concentration is probably in the range of 40–90 ng/mL. Many female swimmers have a relative iron deficiency with sub-optimal ferritin values. In competitive female swimmers, low ferritin level is an indicator of both iron deficiency and inadequate diet. It can be expected that an adequate nutritional regime in athletes with low ferritin values will lead both to the replenishment of iron stores and to an increase in muscle mass and, ultimately, to an improvement in sports performance.

Abstract Small non-coding RNAs (sncRNAs) make up ~1% of the transcriptome; nevertheless, they play significant roles in regulating cellular processes. Given the complexity of the central nervous system, sncRNAs likely hold particular importance in the human brain. In this study, we provide sncRNA transcriptomic profiles in a range of adult and prenatal brain regions, with a focus on piRNAs, due to their underexplored expression in somatic cells and tissue-specific nature. Using the WIND workflow, which combines two detection methods, we found 1333 (731 miRNAs, 249 piRNAs, 285 snoRNAs, and 68 other sncRNAs) and 1445 unique sncRNAs (770 miRNAs, 307 piRNAs, 289 snoRNAs, and 79 other sncRNAs) in developing and adult brains, respectively. Significant variations were found upon comparison of fetal and adult brain groups, with 82 miRNAs, 17 piRNAs, and 70 snoRNAs enriched in fetal brains and 22 miRNAs, 11 piRNAs in adult brains. This dataset represents a valuable resource for exploring the sncRNA roles in brain function, their involvement in neurological diseases, and the molecular mechanisms behind brain region interactions.

Background. The relevance of this article is substantiated by the high interest of specialists in the field of subject-environment interactions in finding answers to questions about the abilities of the subject to interact with the spatial environment of everyday life, taking into account the psychological resourcefulness of this environment, with a focus on the potential of the spatial conditions of the living environment to ensure positive psychological functioning. Objectives. The article attempts to theoretically substantiate the possibility of using the “competence” construct in order to analyze subject-environment interactions. Methods. The analysis and systematization of theoretical and empirical research in the field of phenomenology of the subject-environment interaction was carried out (G.A. Kovalev, S.K. Nartova-Bochaver, V.I. Panov, etc.) with the focus on the possibility of referring to the methodology of the resource approach in psychology (N.E. Vodopyanova, D.A. Leontiev, V.I. Morosanova, E.A. Sergienko, V.A. Tolochek, S.A. Khazova, etc.), as well as in the field of ecopsychology of everyday life (S.E. Gabidulina, T.V. Drobysheva, A.L. Zhuravleva, O.A. Kaptsevich , S.K. Nartova-Bochaver, I.S. Samoshkina, T.V. Semenova, etc.). Results. Theoretical approaches are singled out, within the framework of which the interaction in the “environment-subject” system is operationalized with an emphasis, firstly, on the potential conditions of the spatial environment, secondly, on the individual psychological possibilities of the subject, in particular, the ability to be the subject of mental activity in determining resourcefulness of spatial environment in everyday life. The research in the field of determining the construct of “psychological resources” was analyzed as well as research connected with the description of psychological resourcefulness for the different types of living environment: urban, living, professional. The research directions of interactions between potential conditions of spatial environment of everyday life and subjectional possibilities of using these conditions as the psychological resource for optimization of psychological functioning were determined. The appeal to the construct of “competence” as a promising theoretical and applied direction of research in the field of the relationship between the subject and the spatial environment of everyday life is indicated. Conclusions. Considering statements of environmental psychology, ecopsycology of development, everyday life psychology, as well as being based on an opportunity to consider spatial environment of everyday life as a resource that is directed to the optimization of psychological well-being of the subject, it is proposed to consider competence in subject-environment interactions as the ability of the subject to transform conditions or potential of the spatial environment of everyday life into psychological resource, necessary to maintain optimal functioning.

Abstract Background Despite the success of antiretroviral therapy (ART), people living with HIV (PLWH) suffer from a high burden of pulmonary diseases, even after accounting for their smoking status. Cytotoxic CD8 T-cells are likely implicated in this phenomenon and may act as a double-edged sword. While being essential in viral infection control, their hyperactivation can also contribute to lung mucosal tissue damage. The effects of HIV and smoking on pulmonary mucosal CD8 T-cell dynamics has been a neglected area of research, which we address herein. Methods Bronchoalveolar lavage (BAL) fluid were obtained from ART-treated PLWH (median duration of supressed viral load: 9 years; smokers: n = 14; non-smokers: n = 21) and HIV-uninfected controls (smokers: n = 11; non-smokers: n = 20) without any respiratory symptoms or active infection. Lymphocytes were isolated and CD8 T-cell subsets and homing markers were characterized by multiparametric flow cytometry. Results Both smoking and HIV infection were independently associated with a significant increase in frequencies of total pulmonary mucosal CD8 T-cell. BAL CD8 T-cells were primarily CD69 + expressing CD103 and/or CD49a, at least one of the two granzymes (GzmA/GzmB), and little Perforin. Higher expression levels of CD103, CD69, and GzmB were observed in smokers versus non-smokers. The ex vivo phenotype of GzmA + and GzmB + cells revealed increased expression of CD103 and CXCR6 in smokers, while PLWH displayed elevated levels of CX3CR1 compared to controls. Conclusion Smoking and HIV could promote cytotoxic CD8 T-cell retention in small airways through different mechanisms. Smoking likely increases recruitment and retention of GzmB + CD8 Trm via CXCR6 and CD103. Heightened CX3CR1 expression could be associated with CD8 non-Trm recruitment from the periphery in PLWH.

Boron-containing materials, such as hexagonal boron nitride (h-BN), recently shown to be active and selective catalysts for the oxidative dehydrogenation of propane (ODHP), have been shown to undergo significant surface oxyfunctionalization and restructuring. Although experimental ex situ studies have probed the change in chemical environment on the surface, the structural evolution of it under varying reaction conditions has not been established. Herein, we perform global optimization structure search with a grand canonical genetic algorithm to explore the chemical space of off-stoichiometric restructuring of the h-BN surface under ambient as well as ODHP-relevant conditions. A grand canonical ensemble representation of the surface is established, and the predicted 11B solid-state NMR spectra are consistent with previous experimental reports. In addition, we investigated the relative sliding of h-BN sheets and how it influences the surface chemistry with ab initio molecular dynamics simulations. The B-O linkages on the edges are found to be significantly strained during the sliding, causing the metastable sliding configurations to have higher reactivity toward the activation of propane and water.

In analogy to natural enzymes, an elaborated design of catalytic systems with a specifically tailored local chemical environment could substantially improve reaction kinetics, effectively combat catalyst poisoning effect and boost catalyst lifetime under unfavourable reaction conditions. Here we report a unique design of 'Ni(OH)2-clothed Pt-tetrapods' with an amorphous Ni(OH)2 shell as a water dissociation catalyst and a proton conductive encapsulation layer to isolate the Pt core from bulk alkaline electrolyte while ensuring efficient proton supply to the active Pt sites. This design creates a favourable local chemical environment to result in acidic-like hydrogen evolution reaction kinetics with a lowest Tafel slope of 27 mV per decade and a record-high specific activity and mass activity in alkaline electrolyte. The proton conductive Ni(OH)2 shell can also effectively reject impurity ions and retard the Oswald ripening, endowing a high tolerance to solution impurities and exceptional long-term durability that is difficult to achieve in the naked Pt catalysts. The markedly improved hydrogen evolution reaction activity and durability in an alkaline medium promise an attractive catalyst material for alkaline water electrolysers and renewable chemical fuel generation.

Electrochemical carbon capture and concentration (eCCC) offers a promising alternative to thermochemical processes as it circumvents the limitations of temperature-driven capture and release. This review will discuss a wide range of eCCC approaches, starting with the first examples reported in the 1960s and 1970s, then transitioning into more recent approaches and future outlooks. For each approach, the achievements in the field, current challenges, and opportunities for improvement will be described. This review is a comprehensive survey of the eCCC field and evaluates the chemical, theoretical, and electrochemical engineering aspects of different methods to aid in the development of modern economical eCCC technologies that can be utilized in large-scale carbon capture and sequestration (CCS) processes.

The incorporation of charged groups proximal to a redox active transition metal center can impact the local electric field, altering redox behavior and enhancing catalysis. Vanadyl salen (salen = N,N'-ethylenebis(salicylideneaminato)) complexes functionalized with a crown ether containing a nonredox active metal cation (V-Na, V-K, V-Ba, V-La, V-Ce, and V-Nd) were synthesized. The electrochemical behavior of this series of complexes was investigated by cyclic voltammetry in solvents with varying polarity and dielectric constant (ε) (acetonitrile, ε = 37.5; N,N-dimethylformamide, ε = 36.7; and dichloromethane, ε = 8.93). The vanadium(V/IV) reduction potential shifted anodically with increasing cation charge compared to a complex lacking a proximal cation (ΔE1/2 > 900 mV in acetonitrile and >700 mV in dichloromethane). In contrast, the reduction potential for all vanadyl salen-crown complexes measured in N,N-dimethylformamide was insensitive to the magnitude of the cationic charge, regardless of the electrolyte or counteranion used. Titration studies of N,N-dimethylformamide into acetonitrile resulted in cathodic shifting of the vanadium(V/IV) reduction potential with increasing concentration of N,N-dimethylformamide. Binding constants of N,N-dimethylformamide (log(KDMF)) for the series of crown complexes show increased binding affinity in the order of V-La > V-Ba > V-K > (salen)V(O), indicating an enhancement of Lewis acid/base interaction with increasing cationic charge. The redox behavior of (salen)V(O) and (salen-OMe)V(O) (salen-OMe = N,N'-ethylenebis(3-methoxysalicylideneamine) was also investigated and compared to the crown-containing complexes. For (salen-OMe)V(O), a weak association of triflate salt at the vanadium(IV) oxidation state was observed through cyclic voltammetry titration experiments, and cation dissociation upon oxidation to vanadium(V) was identified. These studies demonstrate the noninnocent role of solvent coordination and cation/anion effects on redox behavior and, by extension, the local electric field.

The superconducting hydrides LaH10, EuH9 and UH8 are studied using chemically intuitive bonding analysis of periodic and molecular models. We find trends in the crystallographic and electronic structures of the materials by focusing on chemically meaningful building blocks in the predicted H sublattices. Atomic charge calculations, using two complementary techniques, allow us to assign oxidation states to the metals and divide the H sublattice into neutral and anionic components. Cubic [H8]q- clusters are an important structural motif, and molecular orbital analysis of this cluster in isolation shows the crystal structures to be consistent with our oxidation state assignments. Crystal orbital Hamilton population analysis confirms the applicability of the cluster model to the periodic electronic structure. A Jahn-Teller distortion predicted by MO analysis rationalises the distortion observed in a prior study of EuH9. The impact of this distortion on superconductivity is determined, and implications for crystal structure prediction in other metal-hydrogen systems are discussed. Additionally, the performance of electronic structure analysis methods at high pressures are tested and recommendations for future studies are given. These results demonstrate the value of simple bonding models in rationalizing chemical structures under extreme conditions.

BackgroundThere is a strong need to determine pandemic and postpandemic challenges and effects at the individual, family, community, and societal levels. Post–COVID-19 health and psychosocial effects have long-lasting impacts on the physical and mental health and quality of life of a large proportion of survivors, especially survivors of severe and critical COVID-19, extending beyond the end of the pandemic. While research has mostly focused on the negative short- and long-term effects of COVID-19, few studies have examined the positive effects of the pandemic, such as posttraumatic growth. It is essential to study both negative and positive long-term post–COVID-19 effects and to acknowledge the role of the resources available to the individual to cope with stress and trauma. This knowledge is especially needed in understudied regions hit hard by the pandemic, such as the region of Central and Eastern Europe. A qualitative approach could provide unique insights into the subjective perspectives of survivors on their experiences with severe COVID-19 disease and its lingering impact on their lives. ObjectiveThe aim of the study is to qualitatively explore the experiences of adult survivors of severe or critical COVID-19 throughout the acute and postacute period in 5 Central and Eastern European countries (Bulgaria, Slovakia, Croatia, Romania, and Poland); gain insight into negative (post–COVID-19 condition and quality of life) and positive (posttraumatic growth) long-term post–COVID effects; and understand the role of survivors’ personal, social, and other coping resources and local sociocultural context and epidemic-related situations. MethodsThis is a qualitative thematic analysis study with an experiential reflexive perspective and inductive orientation. The analytical approach involves 2-stage data analysis: national analyses in stage 1 and international analysis in stage 2. Data are collected from adult survivors of severe and critical COVID-19 through in-depth semistructured interviews conducted in the period after hospital discharge. ResultsAs of the publication of this paper, data collection is complete. The total international sample includes 151 survivors of severe and critical COVID-19: Bulgaria (n=33, 21.8%), Slovakia (n=30, 19.9%), Croatia (n=30, 19.9%), Romania (n=30, 19.9%), and Poland (n=28, 18.5%). National-level qualitative thematic analysis is currently underway, and several papers based on national results have been published. Cross-national analysis has started in 2024. The results will be submitted for publication in the third and fourth quarters of 2024. ConclusionsThis research emphasizes the importance of a deeper understanding of the ongoing health and psychosocial challenges survivors face and what helps them cope with these challenges and, in some cases, thrive. It has implications for informing holistic care and improving the health and psychosocial outcomes of survivors of COVID-19 and will be crucial for evaluating the overall impact and multifaceted implications of the pandemic and for informing future pandemic preparedness. International Registered Report Identifier (IRRID)DERR1-10.2196/57596

Summary: Background: Despite successful antiretroviral therapy (ART), frequencies and immunological functions of memory CCR6+ Th17-polarised CD4+ T-cells are not fully restored in people with HIV (PWH). Moreover, long-lived Th17 cells contribute to HIV persistence under ART. However, the molecular mechanisms underlying these observations remain understudied. Methods: mRNA-sequencing was performed using Illumina technology on freshly FACS-sorted memory CCR6+CD4+ T-cells from successfully ART-treated (ST), elite controllers (EC), and uninfected donors (HD). Gene expression validation was performed by RT-PCR, flow cytometry, and in vitro functional assays. Findings: Decreased Th17 cell frequencies in STs and ECs versus HDs coincided with reduced Th17-lineage cytokine production in vitro. Accordingly, the RORγt/RORC2 repressor NR1D1 was upregulated, while the RORγt/RORC2 inducer Semaphorin 4D was decreased in memory CCR6+ T-cells of STs and ECs versus HDs. The presence of HIV-DNA in memory CCR6+ T-cells of ST and EC corresponded with the downregulation of HIV restriction factors (SERINC3, KLF3, and RNF125) and HIV inhibitors (tetraspanins), along with increased expression of the HIV-dependency factor MRE11, indicative of higher susceptibility/permissiveness to HIV-1 infection. Furthermore, markers of DNA damage/modification were elevated in memory CCR6+ T-cells of STs and ECs versus HDs, in line with their increased activation (CD38/HLA-DR), senescence/exhaustion phenotype (CTLA-4/PD-1/CD57) and their decreased expression of proliferation marker Ki-67. Interpretation: These results reveal new molecular mechanisms of Th17 cell deficit in ST and EC PWH despite a successful control of HIV-1 replication. This knowledge points to potential therapeutic interventions to limit HIV-1 infection and restore frequencies, effector functions, and senescence/exhaustion in Th17 cells. Funding: This study was funded by the Canadian Institutes of Health Research (CIHR, operating grant MOP 142294, and the Canadian HIV Cure Enterprise [CanCURE 2.0] Team Grant HB2 164064), and in part, by the Réseau SIDA et maladies infectieuses du Fonds de recherche du Québec-Santé (FRQ-S).

We report the size-dependent activity and stability of supported Pt1,4,7,8 for electrocatalytic hydrogen evolution reaction, and show that clusters outperform polycrystalline Pt in activity, with size-dependent stability. To understand the size effects, we use DFT calculations to study the structural fluxionality under varying potentials. We show that the clusters can reshape under H coverage and populate an ensemble of states with diverse stoichiometry, structure, and thus reactivity. Both experiment and theory suggest that electrocatalytic species are hydridic states of the clusters (≈2 H/Pt). An ensemble-based kinetic model reproduces the experimental activity trend and reveals the role of metastable states. The stability trend is rationalized by chemical bonding analysis. Our joint study demonstrates the potential- and adsorbate-coverage-dependent fluxionality of subnano clusters of different sizes and offers a systematic modeling strategy to tackle the complexities.