Thermodynamic Origin of Negative Thermal Expansion Based on a Phase Transition-Type Mechanism in the GdF-TbF System.

Multicomponent fluorides of (s-) are () materials. NTE-II occurs in F-F systems formed by "mother" single-component dimorphic F ( = Pm, Sm, Eu, and Gd) with a giant NTE-II. There are two structural types of F polymorphic modifications: low-temperature β-YF (-) and high-temperature LaF (-).

The Study of the Caudal Vertebrae of Thick-Toed Geckos after a Prolonged Space Flight by X-ray Phase-Contrast Micro-CT.

The proximal caudal vertebrae and notochord in thick-toed geckos (TG) (, Gray, 1864) were investigated after a 30-day space flight onboard the biosatellite Bion-M1. This region has not been explored in previous studies. Our research focused on finding sites most affected by demineralization caused by microgravity (G0).

Unlocking the out-of-plane dimension for photonic bound states in the continuum to achieve maximum optical chirality.

The realization of lossless metasurfaces with true chirality crucially requires the fabrication of three-dimensional structures, constraining experimental feasibility and hampering practical implementations. Even though the three-dimensional assembly of metallic nanostructures has been demonstrated previously, the resulting plasmonic resonances suffer from high intrinsic and radiative losses. The concept of photonic bound states in the continuum (BICs) is instrumental for tailoring radiative losses in diverse geometries, especially when implemented using lossless dielectrics, but applications have so far been limited to planar structures.

Laser-Induced Periodic Surface Structures on Layered GaSe Crystals: Structural Coloring and Infrared Antireflection.

We study structural and morphological transformations caused by multipulse femtosecond-laser exposure of Bridgman-grown ϵ-phase GaSe crystals, a van der Waals semiconductor promising for nonlinear optics and optoelectronics. We unveil, for the first time, the laser-driven self-organization regimes in GaSe allowing the formation of regular laser-induced periodic surface structures (LIPSSs) that originate from interference of the incident radiation and interface surface plasmon waves. LIPSSs formation causes transformation of the near-surface layer to amorphous GaSe at negligible oxidation levels, evidenced from comprehensive structural characterization.

Strategies for Anisotropic Fibrillar Hydrogels: Design, Cell Alignment, and Applications in Tissue Engineering.

Efficient cellular alignment in biomaterials presents a considerable challenge, demanding the refinement of appropriate material morphologies, while ensuring effective cell-surface interactions. To address this, biomaterials are continuously researched with diverse coatings, hydrogels, and polymeric surfaces. In this context, we investigate the influence of physicochemical parameters on the architecture of fibrillar hydrogels that significantly orient the topography of flexible hydrogel substrates, thereby fostering cellular adhesion and spatial organization.

Isolation of cubic SiP in the form of nanocrystals.

This article describes an approach for synthesizing silicon phosphide nanoparticles with a defective zinc blende structure under mild conditions through thermal annealing of hydrogenated silicon nanoparticles with red phosphorus. The synthesized SiP nanoparticles were analyzed using FTIR, XRD, electron diffraction, EDX, TEM, Raman spectroscopy, X-ray fluorescence spectrometry, and UV-vis spectrophotometry. For the isolated cubic SiP phase, a cell parameter of = 5.

Association of 2-oxoacid dehydrogenase complexes with respirasomes in mitochondria.

In the present study, cryo-electron tomography was used to investigate the localization of 2-oxoacid dehydrogenase complexes (OADCs) in cardiac mitochondria and mitochondrial inner membrane samples. Two classes of ordered OADC inner cores with different symmetries were distinguished and their quaternary structures modeled. One class corresponds to pyruvate dehydrogenase complexes and the other to dehydrogenase complexes of α-ketoglutarate and branched-chain α-ketoacids.

Hexakis-2-(β-carboxyethenylphenoxy)cyclotriphosphazene: Synthesis, Properties, Modeling Structure.

Condensation of hexakis-2-(formylphenoxy)cyclotriphosphazene with malonic acid yielded hexakis-2-(β-carboxyethenylphenoxy)cyclotriphosphazene (2-CEPP), whose structure was confirmed by P, H, C NMR spectroscopy and MALDI-TOF mass spectrometry. A quantum-chemical calculation for the 2-CEPP molecule using the ab initio methods in the 6-311G basis set and the DFT-PBE0/6-311g** method was performed with geometry optimization of all parameters by the standard gradient method. The acid strength of 2-CEPP was theoretically estimated.

The Synthesis, Structure, and Luminescent Properties of TmMgBO Crystals.

TmMgBO spontaneous crystals were synthesized via the flux-growth technique from a KMoO-based solvent. The crystal structure of the compound was solved and refined within the space group 2/. The first principles calculations of the electronic structure reveal that TmMg-pentaborate with an ideal not defected crystal structure is an insulator with an indirect energy band gap of approximately 6.

Two-Component Rare-Earth Fluoride Materials with Negative Thermal Expansion Based on a Phase Transition-Type Mechanism in 50 F-'F ( = La-Lu) Systems.

The formation of materials with () based on a () in 50 (temperature-composition) F-'F ( = La-Lu) systems out of 105 possible is predicted. The components of these systems are "" F compounds ( = Pm, Sm, Eu, and Gd) with (), which occur during heating between the main structural types of F: -(β-YF) → -( LaF). The PolTr is characterized by a : the (V) of the low-temperature modification (V) is higher than that of the high-temperature modification (V) by a value (up to 4.

doping of epitaxial diamond with germanium by microwave plasma CVD in GeH-CH-H mixtures with optical emission spectroscopy monitoring.

We report the growth of Ge-doped homoepitaxial diamond films by microwave plasma CVD in GeH-CH-H gas mixtures at moderate pressures (70-100 Torr). Optical emission spectroscopy was used to monitor Ge, H, and C species in the plasma at different process parameters, and trends for intensities of those radicals, gas temperature, and excitation temperature, with variations of GeH or CH precursor concentrations, were investigated. The film deposited on (111)-oriented single crystal diamond substrates in a high growth rate regime revealed a strong emission of a germanium-vacancy (GeV) color center with a zero-phonon line at ≈604 nm wavelength in photoluminescence (PL) spectra, confirming the successful doping.

The size effect of BiFeO nanocrystals on the spatial spin modulated structure.

The spatial spin modulated structure (SSMS) of the cycloid type present in bulk BiFeO prevents the linear magnetoelectric effect. One way to influence this structure is to reduce the crystal size to the nanoscale. Various opinions are circulating in the literature about the effect of nanocrystal size on SSMS, and to investigate this issue, we used a number of methods, with zero-field NMR (ZF NMR) spectroscopy at the forefront.

Preparation of high-crystalline and non-metal modified g-CN for improving ultrasound-accelerated white-LED-light-driven photocatalytic performances.

As a non-metallic organic semiconductor, graphitic carbon nitride (g-CN) has received much attention due to its unique physicochemical properties. However, the photocatalytic activity of this semiconductor faces challenges due to factors such as low electronic conductivity and limited active sites provided on its surface. The morphology and structure of g-CN, including macro/micro morphology, crystal structure and electronic structure can affect its catalytic activity.

Transformation of Specific Dispersion Interactions between Cellulose and Polyacrylonitrile in Solutions into Covalent Interactions in Fibers.

Morphological transformations in emulsions of cellulose and polyacrylonitrile (PAN) ternary copolymers containing acrylonitrile, methyl acrylate, and methylsulfonate comonomers in -methylmorpholine--oxide were studied over the entire range of concentrations depending on temperature and intensity of the deformation action. Based on the morphological and rheological features of the system, the temperature-concentration range of spinnability of mixed solutions was determined, and composite fibers were spun. The fibers are characterized by a heterogeneous fibrillar texture.

A Porous Nanostructured ZnO Layer for Ultraviolet Sensing with Quartz Crystal Microbalance Technique.

Porous films of metals and metal oxides have gained growing attention as potential materials for use in applications that require large, specific surface areas, such as sensors, supercapacitors, and batteries. In this study, a "black-metal"-like porous Zn-ZnO composite layer was grown by room temperature co-sputtering of Zn metal and ZnO:Ga (3 at/%) ceramic targets. Following deposition, a porous ZnO layer was obtained by a subsequent thermal annealing process at 400 °C in air.

Non-Fermi-Liquid Behavior of Superconducting SnH.

The chemical interaction of Sn with H by X-ray diffraction methods at pressures of 180-210 GPa is studied. A previously unknown tetrahydride SnH with a cubic structure (fcc) exhibiting superconducting properties below T  = 72 K is obtained; the formation of a high molecular C2/m-SnH superhydride and several lower hydrides, fcc SnH , and C2-Sn H , is also detected. The temperature dependence of critical current density J (T) in SnH yields the superconducting gap 2Δ(0) = 21.

Impact of Ge Doping on Structural and Magnetic Ordering in RMnGa and RMnGaGe (R = Tb, Dy; ≤ 0.25, ≈ 1.0-3.3).

Single crystals of RMnGa and their new quaternary derivatives RMnGaGe (R = Tb, Dy, ≤ 0.25, ≈ 1.0-3.

Vortex Phase Dynamics in Yttrium Superhydride YH at Megabar Pressures.

A comprehensive study of vortex phases and vortex dynamics is presented for a recently discovered high-temperature superconductor YH with (onset) of 215 K under a pressure of 200 GPa. The thermal activation energy () is derived within the framework of the thermally activated flux flow (TAFF) theory. The activation energy yields a power law dependence ∝ on magnetic field with a possible crossover at a field around 8-10 T.

Upconversion Nanoparticles Intercalated in Large Polymer Micelles for Tumor Imaging and Chemo/Photothermal Therapy.

Frontiers in theranostics are driving the demand for multifunctional nanoagents. Upconversion nanoparticle (UCNP)-based systems activated by near-infrared (NIR) light deeply penetrating biotissue are a powerful tool for the simultaneous diagnosis and therapy of cancer. The intercalation into large polymer micelles of poly(maleic anhydride-alt-1-octadecene) provided the creation of biocompatible UCNPs.

Chiral electroluminescence from thin-film perovskite metacavities.

Chiral light sources realized in ultracompact device platforms are highly desirable for various applications. Among active media used for thin-film emission devices, lead-halide perovskites have been extensively studied for photoluminescence due to their exceptional properties. However, up to date, there have been no demonstrations of chiral electroluminescence with a substantial degree of circular polarization (DCP) based on perovskite materials, being critical for the development of practical devices.

Laser Bioprinting with Cell Spheroids: Accurate and Gentle.

Laser printing with cell spheroids can become a promising approach in tissue engineering and regenerative medicine. However, the use of standard laser bioprinters for this purpose is not optimal as they are optimized for transferring smaller objects, such as cells and microorganisms. The use of standard laser systems and protocols for the transfer of cell spheroids leads either to their destruction or to a significant deterioration in the quality of bioprinting.

Proteolytic Resistance Determines Albumin Nanoparticle Drug Delivery Properties and Increases Cathepsin B, D, and G Expression.

Proteolytic activity is pivotal in maintaining cell homeostasis and function. In pathological conditions such as cancer, it covers a key role in tumor cell viability, spreading to distant organs, and response to the treatment. Endosomes represent one of the major sites of cellular proteolytic activity and very often represent the final destination of internalized nanoformulations.

S-nitrosylation and S-glutathionylation of GAPDH: Similarities, differences, and relationships.

The aim of this work was to compare the effect of reversible post-translational modifications, S-nitrosylation and S-glutathionylation, on the properties of glyceraldehyde-3-phosphate dehydrogenase (GAPDH), and to reveal the mechanism of the relationship between these modifications. Comparison of S-nitrosylated and S-glutathionylated GAPDH showed that both modifications inactivate the enzyme and change its spatial structure, decreasing the thermal stability of the protein and increasing its sensitivity to trypsin cleavage. Both modifications are reversible in the presence of dithiothreitol, however, in the presence of reduced glutathione and glutaredoxin 1, the reactivation of S-glutathionylated GAPDH is much slower (10% in 2 h) compared to S-nitrosylated GAPDH (60% in 10 min).

Comparative study of calcification in human choroid plexus, pineal gland, and habenula.

Choroid plexus, pineal gland, and habenula tend to accumulate physiologic calcifications (concrements) over a lifetime. However, until now the composition and causes of the intracranial calcifications remain unclear. The detailed analysis of concrements has been done by us using X-ray diffraction analysis (XRD), X-ray diffraction topography (XRDT), micro-CT, X-ray phase-contrast tomography (XPCT), as well as histology and immunohistochemistry (IHC).

Can the Sublimation Enthalpy Be Obtained Using Atomic Force Microscopy with Heating? A PETN Nanofilm Case.

Vaporization is an important aspect of the performance and detection of energetic materials. While the traditional techniques concentrate on bulk property changes during sublimation, atomic force microscopy (AFM) offers the possibility to track particle volume changes under heating. Ideally, this will enable the investigation of chemicals that are challenging to study using conventional vaporization analysis methods, i.