Cobalt(II) enters the trigonal channels of calcium-lanthanum and strontium-lanthanum germanate apatites, forming the nonlinear dioxocobaltate(II) ion [OCoO]2-. Samples reveal two magnetization relaxation processes: SR1 characterized by a Ueff of 47-48 cm-1 and SR2 with considerably extended relaxation times and a weak temperature dependence. The relaxation times of SR1 show an unusual steplike drop with increasing temperature, which correlates with the SR2 contribution to the magnetization. Temperature and field dependence of the magnetization are described by an axial zero-field splitting model, yielding negative D values corresponding well to the Ueff values obtained. Modeling the electronic structure of the dioxocobaltate(II) ion provides information about the Co-O distance ranges corresponding to two different ground states, a moderately anisotropic spin-only one with spin S = 3/2 and an extremely anisotropic non-Aufbau one with S = 3/2 and an orbital angular moment L = 3. Experimental D and g|| values correspond to certain Co-O distances in the spin-only state. The distances follow a qualitative relation with estimated Coulomb forces acting between ions in the host compound. These findings suggest that to convert the dioxocobaltate(II) anion into the desired non-Aufbau state, one must construct a host apatite crystal from ions with lower charges and larger sizes.

We report on the most efficient mediator-free bioelectrocatalysis by flavine adenine dinucleotide-dependent glucose dehydrogenase (FAD-GDH) achieved through its anchoring with poly(Methylene Green) (poly(MG)) nanoparticles upon immobilization. The ratio of direct-to-mediated currents, reflecting the fraction of the enzyme molecules involved into direct electron transfer, reaches the values up to 0.5. The half-wave potential of mediator-free glucose oxidation on FAD-GDH electrode equals to-140 mV, being thus determined by redox potential of the cofactor, rather than of poly(MG). Facilitated electron transport between the active site and the electrode results in a sharp current increase in polarographic wave with a slope of ti 35 mu A center dot cm-2 center dot V-1. Thereby, the limiting bioelectrocatalytic current plateau region starts from-100 mV, which ranks the elaborated enzyme electrodes with the most low-potential glucose biosensors. To circumvent low intrinsic activity of FAD-GDH we suggest using pulse amperometry readout, which provides more than 50-fold response amplification and significantly improved signal-to-background ratio. The achieved performances allow reliable continuous analysis of sweat with the on-skin device, which enables non-invasive glycemia monitoring.

The paper reports on ethanol and water vapors sorption and diffusivity in hardly oxidized Hummers graphene oxide (GO) membranes (flake size similar to 6 mu m, thickness similar to 100 nm) investigated with in situ and in operando X-ray scattering, IR spectroscopy, spin probe electron paramagnetic resonance (EPR) and permeance measurements. Both volumetric and mass sorption isotherms were established for swelling of GO membranes depending on partial pressure of water and ethanol vapors. It has been shown that the nanoslits widening in GO from similar to 0.75 to similar to 1.35 nm occurs with sorption of up to similar to 0.045 mol/g(GO) for water and similar to 0.009 mol/g(GO) for ethanol, corresponding accommodation of up to 1.24H(2)O or 0.24C(2)H(5)OH molecules per carbon atom. The membranes exhibit very low permeance towards ethanol vapors (<8.510(-10) mol m(-2) Pa-1s(-1)), while revealing typical GO permeance of similar to 110(-6) mol m(-2) Pa-1s(-1) for water molecules. A huge (>3 orders of magnitude) difference in H2O and C2H5OH permeance is explained with preferential sorption of water and significant difference of the activation barriers for water and ethanol transport in nanoslits. Sorption selectivity for H2O:C2H5OH pair of over 50 was disclosed with in-situ IR measurements, and the effect of nanoslit width on molecular diffusivity adding a factor of 10 was exposed with EPR of spin probes. Both preferential sorption and diffusivity of water was confirmed with semi-empirical modelling, exposing a strong impact of guest phase density on a barrier height. The results are instructive for application of GO in separation of water-alcohol and water-organic solvent mixtures.

The name of one of the authors of the article by Grigoryeva et al. [ J. Appl. Cryst. (2026), 59 , 1129–1138] is corrected.

In this work we characterize mixed Mo-W acidic deposition solutions with Mo content ranging from 0 to 100 mol.% by Raman and UV-Vis spectroscopy. The obtained distribution diagram of mixed isopolyanions allows one to explain the observed change in film deposition rate with increase in Mo content. It was found that the initial decrease in deposition rate correlates with decrease in [W10O32](4)(-) concentration, while the further increase in deposition rates correlates with the increase in [H3Mo3W15O60](9-) complex concentration in deposition solutions. The EDX and UV-Vis analysis of film compositions confirms the preferential deposition of mixed oxotungstate film with Mo:W ratio similar to 1:4 in solutions with >20 mol.% Mo. XRD and Raman confirmed that films consist of solid solutions with composition MoxW1-xO32H(2)O, with Mo fraction x ranging from 0 to 0.22. For the first time, the possibility of forming such single-phase solutions over a wide composition range was demonstrated. Potential-dependent optical absorption, coloration-decoloration kinetics, and capacity of the films are studied. Mo doping shifts the onset of coloration to more positive potentials and increases the optical density around 600 nm compared with undoped films. Although the coloration time increases slightly with Mo addition (from 1 to 3 s), the self-bleaching rate decreases by nearly an order of magnitude, indicating improved stability of the colored state.

Hydrogel-based evaporative cooling has emerged as a promising passive strategy for thermal management in photovoltaic (PV) systems. However, conventional bulk hydrogels suffer from severe structural deformation and limited water storage capacity, hindering their long-term performance in practical applications. Herein, we developed a polyacrylamide microparticle-assembled hydrogel (MPH) formed through the self-assembly of dehydrated microparticles triggered by water absorption. The as-reconstructed hydrogels establish dynamic interparticle interfaces via physical entanglements, facilitating rapid polymer chain mobility and local structural reorganization during hydration and dehydration. The flexible structure of the MPH mitigates drying-induced stress and reduces undesirable inhomogeneous deformation, ensuring sustained thermal contact between the hydrogel and the PV panel throughout evaporation. Meanwhile, the dynamic network enhances water molecule mobility and improves the water absorption capacity. Leveraging the fast water uptake of the MPH, we engineered a water-fed cooling system integrating a capillary-driven layer for a continuous water supply. The system achieved a significant temperature drop of 26 °C under an intense heat flux of 1000 W/m2 and demonstrated sustained cooling performance compared to natural convection. This work presents a novel material strategy for efficient and durable thermal management in solar energy applications.

Dysprosium-doped calcium-strontium vanadate(V) hydroxyapatites (Ca1-ySry)10(VO4)6(OH)2:Dy, y = 0-0.4, were synthesized by the solid-state reaction at temperatures between 900 and 1000 °C. Dy3+ substitutes for Ca2+ at the 6h Wyckoff site (Ca2) and displaces strongly toward the isolated oxygen anion imbedded in the trigonal channel. This results in the formation of dysprosyl ion DyO+ with a short bond length of 2.15 Å. In zero external magnetic field and below 65 K, the compounds exhibit slow relaxation of the magnetization. With increasing strontium content y, the energy barrier for remagnetization grows from 614 cm-1 to 699 cm-1, the magnetization blocking temperature changes from 3 to 5.5 K, and the magnetization hysteresis at T = 2 K extends from 12 to 16 kOe. The photoluminescence bands exhibit a large crystal field splitting that increases with y. The electronic energy level diagram of Dy3+ obtained from the luminescence data agrees well with the measured magnetic properties. That is the first example of the DyO+ single-ion magnet (SIM) in a nonphosphate compound. This provides an opportunity for comparative studies to reveal new relations between crystal structure details and SIM parameters.

Monitoring molecular processes at the single-cell level is vital for understanding cancer cell heterogeneity and drug responses. Here, we present gold-modified silicon microneedles (Au@Si-MNs) as a multifunctional platform combining single-cell immobilization with surface-enhanced Raman spectroscopy (SERS) for real-time intracellular analysis. These microneedles, fabricated with crown-shaped gold nanostructures at the tips, provide a SERS-active surface and enable spatially resolved detection of cellular components while maintaining cell viability for up to 72 h. Using SERS, we captured molecular signatures from MDA-MB-231 breast cancer cells immobilized on Au@Si-MNs. Distinct spectral peaks highlighted nucleic acid and protein distributions within the nucleus and cytoplasm. Au@Si-MNs preloaded with doxorubicin (DOX) enabled localized drug delivery, with real-time SERS monitoring revealing molecular changes associated with drug uptake and cytotoxicity over 48 h. Live/dead imaging confirmed effective DOX-induced cell death while demonstrating the biocompatibility of the microneedles. This study establishes Au@Si-MNs as a versatile platform for high-resolution single-cell analysis and precise intracellular drug delivery. The dual functionality of Au@Si-MNs paves the way for advanced applications in cancer research, enabling detailed insights into molecular mechanisms and drug-cell interactions crucial for the development of precision therapies.

We report on the approach enabling first-generation biosensor-based test-strips to respond linearly up to 40 mM glucose concentration. Glucose oxidase (GOD) has been chosen as the most selective biocatalyst. Decreasing its content in the enzyme containing membrane so that [E]0 approximate to [S]0, it is possible to increase an apparent Michaelis constant prolonging linear calibration range. Prussian Blue (PB) acting as a transducer practically prevents false-positive responses caused by reductants. Novel bi-pulse power generation readout with overall measurement duration of 5.005 s provides up to 10-fold enhanced sensitivity (17 +/- 3 mA & sdot;M-1 & sdot;cm-2), which compensates its obvious loss caused by the decrease of the enzyme content. Coupled with an advanced readout, the resulting test-strips become suitable for whole blood analysis even upon monitoring of diabetes.

The paper resolves a puzzling relation of water permeance of graphene oxide (GO) membranes on vapors activity and interlayer spacing. In-operando X-ray diffraction was involved to follow the interlayer spacing in thin (similar to 100 nm) and thick (similar to 6 mu m) GO membranes over a wide range of operation conditions. It is shown, the permeance of GO towards water vapors grows exponentially (from <0.15 to 250 m(3)(STP)m(-2)bar(-1)h(-1)) with a slit width, which depends on water activity at both feed and permeate sides. The interlayer spacing of GO membranes does not equilibrates with neither feed or permeate side activity during vapors permeation, but reaches equilibrium for GO contacted with liquid water in pervaporation experiments. In-depth analysis of the interlayer spacing with grazing incidence diffraction illustrates its uniform distribution over the membrane thickness and reveals very small water activity gradient within the membrane (similar to 10 % of the applied gradient). The permeability of graphene oxide layers evaluated with this gradient exposes an ultimate permeance up to similar to 3000 m(3)(STP)m(-2)bar(-1)h(-1) and corresponding permeability of 1-610(5) Barrer, providing an unambiguous experimental evidence for almost an unimpeded water transport through GO. That contraposes apparent activation energy of water transport similar to 25 kJ/mol. The restrain of water transport was explained by the heat-transfer limitation typical for condensation-transport-evaporation process and exposed with a strong temperature drop of similar to 6 degrees C at the permeate side of the membrane. The reported correlations of permeance, nanoslit sizes and water activity in feed and permeate are instructive for application of GO in dehumidification and pervaporation technologies.

Homofullerenes are the class of fullerene derivatives where all fullerene carbon atoms remain in the sp(2)-state. This is facilitated by cleavage of the skeletal C-C bonds between the adjacent sites of attachment of divalent addends, e.g. certain types of >CX2 groups. Homofullerenes rarely reveal any important differences in optical and chemical properties compared to pristine fullerenes. Here we report an important novel example of such rare differences: formation of new fullerene polymer phases under thermal and high-pressure treatment as evidenced by the in situ and ex situ studies by means of Raman spectroscopy, HRTEM and XPS. Initially, C-60(CF2) molecules undergo dimerization yielding double-caged multiply linked [C-60(CF2)](2) dimers. High-pressure treatment of C-60(CF2) with additional shear stress leads to phase transitions observed up to 27 GPa yielding high-pressure phases (IV and V) with partial defluorination. This behavior is qualitatively similar to that of pristine C-60, but due to the presence of the CF2 moiety, the pressures required are 5-8 GPa higher compared to pristine C-60. While the shear loads distort the crystal lattice of the C-60(CF2) sample, interplane distances are preserved, indicatively of the lack of long polymeric fullerene chains typical of pristine C-60. Most importantly, high-pressure phase V of C-60(CF2) demonstrates a transition at 45 GPa yielding an even harder phase which remains stable under 45-80 GPa loads.

Defect engineering in oxide materials is typically achieved through manipulation of oxygen pressure and temperature, followed by quenching which freezes the concentration of point defects. Unlike oxides, halide perovskites equilibrate with gaseous atmosphere at room temperature. Information on defect engineering in halide perovskites that utilize the concentration of gaseous species is scarce and controversial. In this report we address this controversy by studying the interaction of MAPbI(3) with molecular iodine over a wide range of partial pressures and reveal the two regimes of such interaction: defect control regime and polyiodide formation regime switching at similar to 20 % of the saturated iodine pressure. In defect control regime the material undergoes reversible changes in semiconductor properties, while in polyiodide formation regime the material undergoes irreversible changes in crystallinity and microstructure. These findings emphasize the manifold role of molecular iodine for this class of materials and provides researchers with the experimental framework that can be utilized to tune stoichiometry and conductivity of halide perovskites to further enhance the performance and stability metrics of the corresponding devices.

A comprehensive experimental investigation and theoretical description of liquid-gas pervaporative transport across nanoporous membranes is presented. Anodic alumina and track-etched membranes, featuring straight channels within a diameter range of 25-200 nm, were experimentally tested in pervaporation of liquid water, alcohols and hydrocarbons at various operation conditions. The pivotal role of the equilibrium saturation pressure of penetrants (varied from similar to 10 to similar to 50,000 Pa) on the membranes performance was exposed, while no significant influence of neither channel diameters nor membrane thickness was revealed. Pervaporative flux, exceeding 1.510(-5) molm(-2)s(-1)Pa-1 (similar to 10 kgm(-2)h(-1)atm(-1) for water at 60 degrees C), surpasses Knudsen permeability of the membranes, indicating liquid transport driven by Laplace pressure. However, it lies far below the theoretical Hertz-Knudsen limit for evaporating menisci, revealing heat transfer limitation. The study rivals a substantial temperature drop, reaching 30 degrees C at the evaporation plane. That is proportional to the square root of the saturation pressure of penetrants, as revealed by experimental results and theoretical description. It results in transport limitation with heat supply to the evaporation menisci, constrained especially at the membrane interfaces. Strong cooling of the evaporative plane suppresses pervaporative flux with diminishing local saturation pressure of penetrants. The provided description provides low relative deviation (<30 %) within the whole set of penetrants and membrane microstructures. It was successfully utilized for improving stability of nanoporous membranes in desalination pervaporation with deposition of highly permeable thin graphene oxide and MXene selective addlayers. Composite membranes reveal a slight lowering of the performance compared to the nanoporous substrates, while having a greatly enhanced long-term stability in pervaporative desalination with ions rejection.

In this study, a novel approach for simultaneous interferometric and surface-enhanced Raman spectroscopy (SERS) detection of bacteria utilizing porous silicon nanowires (pSi NWs) modified with silver and gold nanoparticles is reported. The pSi NWs were fabricated through gold-assisted chemical etching of p-type, single-crystal silicon wafers with a (100) crystallographic orientation and resistivity between 1 and 5 mΩ·cm. Following etching, the nanowires' surfaces were modified with silver, then gold nanoparticles by reduction from their respective salts in the presence of 5 M HF. This dual-mode sensing platform was tested with Listeria innocua, a nonpathogenic strain of Listeria, demonstrating significant interferometric fringe shifts after bacterial adsorption due to changes in the samples' effective optical thickness. This interferometric method achieved detection limits of L. innocua down to 6.4 × 106 CFU/mL. Additionally, the plasmonic nanoparticle-modified nanowires exhibited strong SERS activity, enabling Raman spectral detection of adsorbed bacteria with a sensitivity limit of 3.2 × 106 CFU/mL. This work demonstrates the potential of AuAg-modified pSi NWs as a versatile and highly sensitive dual-mode optical sensor for rapid bacterial detection, offering both real-time refractive index-based interferometric monitoring and molecularly specific SERS capabilities.

Variation of water permeance and interlayer spacing of graphene oxide (GO) is traced with in-situ X-ray diffraction upon its heating/cooling in dry (-1000 Pa), humid (-100 % RH) air and liquid water. Reversible variation of GO interlayer distance ranging 8.3-7.2 a in dry air, 11-7.5 a in humid air and 13.9-12.4 a in liquid water is revealed in the temperature range of 25-80 degrees C. Accounting for GO layer thickness of -6 a it corresponds manifold alterations of slit width with temperature and water vapor pressure, resulting in over 3 orders of magnitude variation of membrane performance. A typical rise of the permeance of 300-500 % within the temperature range at constant humidity is contraposed to a miserable increase in the activation energy for H2O transport, revealing the decisive impact of slit sizes on GO performance. The effect is addressed to entropy-driven variation of water absorption heat with slit sizes in GO. Variation of interlayer spacing of -10 % was also exposed with thermal dissociation of GO groups and H+ migration to the interlayer space as supported by semiempirical calculations. Reversible structural changes in GO are successfully exploited for fabrication thermally switched membranes for dehumidification with initial permeance of -1.1 & sdot;10-6 mol m- 2 Pa- 1 & sdot;s- 1 and its variation over 50 % at supplied power of -500 W/m2.

In this paper, the possibility of detecting viruses, specifically influenza A virus, based on changes in the spectra of total reflection from macroporous silicon (macro-pSi) films, is demonstrated for the first time. Macro-pSi films with a pore diameter of about 100 nm were produced by electrochemical etching of crystalline silicon substrates. The porosity of the macro-pSi, calculated using the Bruggeman effective medium model, was 75

Two new VIS-excited NIR-emitting ytterbium complexes Yb(HPTC)(H2O)2 (Yb1) and Yb(HPTC)(Phen) (Yb2) were obtained. Both compounds demonstrated low toxicity for healthy and cancer cells, moreover Yb1 demonstrated selective accumulation in cancer cells.

The early Russian glasses produced from 12th to 14th century, based on PbO-SiO2 and K2O-PbO-SiO2 systems, are a special artistic and productive phenomenon in European medieval culture. Being prepared from sand and washed ash and colored by manganese and copper compounds, they showed a wide variety of colors due to variability of concentrations of lead and chromophores. Here we discuss the color of specific examples of Russian glasses and their modern replica. It is shown that the coloring of lead glasses is affected not only by d-d transitions in metal ions but also by the shift of the fundamental edge caused by the metal ion acting as dopant. The blue coloration of lead glasses achieved by introduction of copper and manganese was a specific receipt developed by Russian glassmakers due to lack of cobalt ore. The inefficiency of manganese for discoloration of lead glasses is also shown. A brief history of Russian glassmaking in 12th–14th centuries is also given.

A first composite material containing uniformly dispersed disaggregated detonation nanocrystalline diamonds (DNDs) in SiO2 aerogel matrix was prepared. The synthetic protocol included hydrolysis of tetramethyl orthosilicate (Si(OMe)4, TMOS) by hydrosol of surface carboxylated DNDs with a typical size of 4‐5 nm with DMSO serving as a cosolvent and a stabilizer of DND single crystals. Composite samples containing DNDs in silica aerogel matrix in concentration 1.0, 0.1 and 0.01% w/w were prepared at ambient temperature. HRTEM data revealed that DNDs nanocrystals were uniformly distributed in aerogel and did not form aggregates. Textural and optical composites’ properties were determined.

Doping of the (Sr,Ba)10(PO4)6(OH)2 apatite ceramics with a small quantity of Dy2O3 was studied. Formation of the Dy3+ containing high-energy single-ion magnet (SIM) in the apatite structure was confirmed. Partial replacement of Ba for Sr in the structure resulted in a regular increase of the remagnetization energy barrier Ueff from 1043 to 1119 cm-1, while the solubility of Dy3+ in the compound dropped drastically. Ueff followed simple relations with the alkaline-earth metal cation size and the compound composition, highlighting predictability of SIM parameters.