bluuebunny/crossref_metadata_2025 huggingface dataset:
Vaccine-induced T cell receptor T cell therapy targeting a glioblastoma stemness antigen
Authors: Chih Yu-Chan , Dietsch Amelie C. , Koopmann Philipp , Ma Xiujian , Agardy Dennis A. , Zhao Binghao , De Roia Alice , Kourtesakis Alexandros , Kilian Michael , Krämer Christopher , Suwala Abigail K. , Stenzinger Miriam , Boenig Halvard , Blum Agnieszka , Pienkowski Victor Murcia , Aman Kuralay , Becker Jonas P. , Feldmann Henrike , Bunse Theresa , Harbottle Richard , Riemer Angelika B. , Liu Hai-Kun , Etminan Nima , Sahm Felix , Ratliff Miriam , Wick Wolfgang , Platten Michael , Green Edward W. , Bunse Lukas
Published: February 2025

T cell receptor-engineered T cells (TCR-T) could be advantageous in glioblastoma by allowing safe and ubiquitous targeting of the glioblastoma-derived peptidome. Protein tyrosine phosphatase receptor type Z1 (PTPRZ1), is a clinically targetable glioblastoma antigen associated with glioblastoma cell stemness. Here, we identify a therapeutic HLA-A*02-restricted PTPRZ1-reactive TCR retrieved from a vaccinated glioblastoma patient. Single-cell sequencing of primary brain tumors shows PTPRZ1 overexpression in malignant cells, especially in glioblastoma stem cells (GSCs) and astrocyte-like cells. The validated vaccine-induced TCR recognizes the endogenously processed antigen without off-target cross-reactivity. PTPRZ1-specific TCR-T (PTPRZ1-TCR-T) kill target cells antigen-specifically, and in murine experimental brain tumors, their combined intravenous and intracerebroventricular administration is efficacious. PTPRZ1-TCR-T maintain stem cell memory phenotype in vitro and in vivo and lyse all examined HLA-A*02+ primary glioblastoma cell lines with a preference for GSCs and astrocyte-like cells. In summary, we demonstrate the proof of principle to employ TCR-T to treat glioblastoma.
A systematised review and evidence synthesis on the broader societal impact of vaccines against Salmonella
Authors: Demirtas Ezgi Dilek , Barnard Rosanna , Lee Jungseok , Jit Mark
Published: February 2025

Vaccines against Salmonella Typhi are available, while vaccines against invasive non-typhoidal Salmonella are in development. Investments in vaccine development and introduction need to be informed by a full value of vaccines assessment, including consideration of broader societal impacts of salmonellae disease. We reviewed literature on these broader impacts in low- and middle-income countries to inform a conceptual framework. We found 16 studies relevant to Salmonella, but only one study on non-typhoidal Salmonella. Despite variations in study design, methodology, and study quality, salmonellae infections were largely associated with negative broader societal impacts, including detriments in childhood physical development (very weak association), childhood educational development (strong to very strong association), household security (moderate association), public health spending (moderate association), and national income (moderate to strong association). Study quality was low for all impacts except childhood physical development. There were no studies measuring economic impact of antimicrobial resistance, changes in household behaviour or health inequalities.
An integrated dataset of spatiotemporal and event data in elite soccer
Authors: Bassek Manuel , Rein Robert , Weber Hendrik , Memmert Daniel
Published: February 2025

Data-driven match analysis in soccer is a growing discipline in both research and practice. However, public data is scarce, which raises the barrier for entering this field and decreases reproducibility of methods and results. To bridge this gap, this paper presents a dataset of official match information, event, and position data from seven matches of the German Bundesliga’s first and second division. The match information contains meta data about the matches and their participants. The event data contain timestamps along with descriptions of discrete events, like passes, shots, or fouls. The position data contain the x/y-coordinates of every player and the ball. By integrating multiple data modalities – i.e., event logs with timestamps, and x-y coordinates of player and ball positions — the dataset offers a multidimensional view of match dynamics. This dataset supports the validation of existing analytical techniques and facilitates the development of new methodologies in sports analytics. With availability under CC-BY 4.0, it promotes transparency, reproducibility, and the idea of open science in match analysis research.
Alpha synuclein overexpression can drive microbiome dysbiosis in mice
Authors: Sampson Timothy R. , Wallen Zachary D , Won Woong-Jai , Standaert David G. , Payami Haydeh , Harms Ashley S.
Published: February 2025

Growing evidence indicates that persons with Parkinson disease (PD), have a unique composition of indigenous gut microbes. Given the long prodromal or pre-diagnosed period, longitudinal studies of the human and rodent gut microbiome before symptomatic onset and for the duration of the disease are currently lacking. PD is partially characterized by the accumulation of the protein α-synuclein (α-syn) into insoluble aggregates, in both the central and enteric nervous systems. As such, several experimental rodent and non-human primate models of α-syn overexpression recapitulate some of the hallmark pathophysiologies of PD. These animal models provide an opportunity to assess how the gut microbiome changes with age under disease-relevant conditions. Here, we used a transgenic mouse strain, which overexpress wild-type human α-syn to test how the gut microbiome composition responds in this model of PD pathology during aging. Using shotgun metagenomics, we find significant, age and genotype-dependent bacterial taxa whose abundance becomes altered with age. We reveal that α-syn overexpression can drive alterations to the gut microbiome composition and suggest that it limits diversity through age. Taxa that were most affected by genotype-age interaction were Lactobacillus and Bifidobacteria. In a mouse model, we showed direct link between alpha synuclein geneotype (hallmark of PD), a dysbiotic and low-diversity gut microbiome, and dysbiotic levels of Bifidobacteria and Lactobacillus (most robust features of PD microbiome). Given emerging data on the potential contributions of the gut microbiome to PD pathologies, our data provide an experimental foundation to understand how the PD-associated microbiome may arise as a trigger or co-pathology to disease.
Exploring health related quality of life for women with breast cancer in Ireland and Québec, Canada throughout the COVID-19 pandemic
Authors: Myers Charlotte , Bennett Kathleen , Cahir Caitriona , Savard Josée , Lauzier Sophie
Published: February 2025

The long-term consequences from the COVID-19 pandemic on breast cancer (BC) is highly unknown, however persisting unmet needs and psychosocial difficulties are likely. The objectives of this study were to evaluate the change in health-related quality of life (HR-QoL) from the pandemic to post-pandemic for women living with a diagnosis of BC and to assess the association between COVID-19 stressor impact and HR-QoL in Ireland and Québec, Canada. Women with a diagnosis of BC were initially enrolled in the cohort study. HR-QoL was assessed during the pandemic (2020–2021) and post-pandemic periods (2022). COVID-19 stressor impact was computed post-pandemic, and change in HR-QoL during and post-pandemic was compared between Ireland and Québec using independent t-tests. Multivariable analysis of covariance (ANCOVA) was used to evaluate the association between COVID-19 stressor impact and changes in HR-QoL, and compare it between Ireland and Québec. 405 participants were included from both settings (Ireland n = 267; Québec n = 138). The average HR-QoL improved from the COVID-19 pandemic to post-pandemic, and there were no differences between Ireland and Québec. Women with high COVID-19 stressor impact (18.9% of participants) had a significantly smaller improvement in their overall HR-QoL compared to those with low COVID-19 stressor impact, and this was evident in Ireland (p < 0.004) and Québec (p < 0.0001) but there were no significant differences between Ireland and Québec (interaction p-value > 0.05). Overall, HR-QoL for women with BC improved from pandemic to post-pandemic period. However, similarly in both settings, women who experienced higher levels of COVID-19-related stress had a slower recovery in HR-QoL. These results can guide decisions about health services and policies to adequately address the on-going effect of the pandemic and also prepare for future health crises.
Changes in optic nerve head microvasculature following disc hemorrhage absorption in glaucomatous eyes
Authors: Yoon Jooyoung , Sung Kyung Rim , Kim Ko Eun , Han Hyo Ji , Kim Joon Mo
Published: February 2025

This study investigated the changes in optic nerve head (ONH) microvasculature, circumpapillary retinal nerve fiber layer (cpRNFL) thickness, and visual field (VF) sensitivity following the absorption of optic disc hemorrhage (DH). Intradisc vessel density (dVD) was calculated using a 3 × 3 mm optic disc scan in 60 eyes of 60 patients with primary open angle glaucoma and DH who had undergone two or more swept-source optical coherence tomography angiography exams. Clinical parameters at the time of DH occurrence and after absorption, as well as those between the subgroups based on DH recurrence and location, were compared. Linear regression analysis was performed to identify factors associated with changes in cpRNFL thickness in the DH-affected quadrant. Mean dVD, cpRNFL thickness, and VF sensitivity significantly decreased after DH absorption (all P < 0.05). The reduction in dVD was more pronounced in eyes with recurrent DH compared to those with a single episode (P = 0.032). Eyes with DH occurring within or at the margin of the disc cup showed a greater dVD reduction than those with DH occurring outside the disc cup (P = 0.049). The reduction in cpRNFL thickness in the DH-affected quadrant correlated with dVD reduction in the same quadrant (β = 0.370, P = 0.013) and DH recurrence (β = -2.617, P = 0.033). This finding suggests that DH pathogenesis may be associated with changes in optic disc vasculature, contributing to glaucomatous progression.
UPLC-QTOF-MS-based metabolomics and chemometrics studies of geographically diverse C. torulosa needles
Authors: Khanna Radhika , Bhadoriya Khushaboo , Pandey Gaurav , Varshney V. K.
Published: February 2025

Marker compounds identification by using metabolomics and chemometrics in Cupressus torulosa.
Transition-metal-free tunable regioselective [3+2] cycloaddition of diaryliodonium salts with 1,3-dicarbonyl derivatives
Authors: Yang Yixi , Wang Shaoqing , Wang Lin , Dang Na , Qin Tao , Zhou Heye , Liu Bin
Published: February 2025

A new [3+2] cycloaddition reaction of diaryliodonium salts with 1,3-dicarbonyl compounds for the synthesis of benzofuran derivatives is reported, involving the sequential selective coupling of dual electrophilic and nucleophilic reagents.
Unraveling the Infrared Detection Properties of Bi2Te3 Depending on Thickness from Semiconductor to Metal Surface States
Authors: Kao Qijun , Jia Yongfeng , Wu Zhihao , Zhou Zhangxinyu , Ge xun , Peng Jian , Martyniuk Piotr , Wang Jin , Wang C. B. , Wang Fang
Published: February 2025

Bi2Te3 emerges as a promising candidate material for the next generation of mid-wave to long-wave Infrared photodetection due to its exceptionally narrow bandgap (approximately 0.2 eV). Furthermore, its topological insulator...
Highly oxidative GaN:ZnO@α-Ga2O3 heterostructure as a visible-light-driven, round-the-clock photocatalyst for dye degradation and disinfection
Authors: Hu Yan-Ling , Zhao Zihan , Jiang Junjie , Huang Yadong , Ji Huayu , Zhu Di , Zhang Lianqi , Zhan Linhan , Wu Yurong , Zhang Yuhui , Wu Kun , Yang Yun , Chai Tian , Wu Sujuan , Song Guang-Ling
Published: February 2025

In a visible-light-driven GaN:ZnO@α-Ga2O3 heterostructure, the GaN:ZnO core absorbed O2 and stored photo-electrons at VO sites to form ·O2−, while the α-Ga2O3 shell absorbed H2O/O2 at VO and trapped photo-holes at VGa to generate ·OH/1O2.
Discovery of 19 strongly lensed, dual, or projected quasars in DESI-LS
Authors: He Zizhao , Chen Qihang , Deng Limeng , Shu Yiping , Li Rui , Li Nan , Shi Dongdong , Li Guoliang
Published: February 2025

We report the results of a follow-up spectroscopic confirmation of two lensed quasars, six dual quasars, and eleven projected quasars that had previously been identified as lensed-quasar candidates in our earlier work. The spectroscopic data were obtained from two different sources: Palomar 200-inch Double Spectrograph (P200/DBSP) in California and publicly available datasets, including SDSS and DESI-EDR. The two lensed quasars (both pairs) have the following properties: theta_E = 1arcsec.208, z_s = 3.105; theta_E = 0arcsec.749, and z_s = 2.395. The six dual quasars have redshifts ranging from 0.58 to 3.28 and projected separations ranging from 15.44 to 22.54 kpc, with a mean separation of 17.95 kpc. The eleven projected quasars have projected separations ranging from 10.96 to 39.07 kpc, with a mean separation of 22.64 kpc. Additionally, there are three likely lensed quasars that cannot be definitively confirmed, included for two reasons. Firstly, their image separations (0arcsec.83, 0arcsec.98, and 0arcsec.93) are small compared to the seeing conditions during our observations (around 1arcsec.2). Secondly, no high signal-to-noise (S/N) lensing galaxy can be feasibly detected in Improved spectroscopy and/or imaging would be needed to confirm their lensing nature.
University digital media co-occurrence networks reveal structure and dynamics of brand visibility in the attention economy
Authors: Petersen Alexander Michael
Published: February 2025

As universities compete for visibility to attract student enrollment and build scientific reputation, the management of institution of higher education (IHE) brand has emerged as an important strategic endeavor. Yet our understanding of the factors that condition the structure and dynamics of brand stratification within regional IHE ecosystems is limited. Instead, our best approximation for brand equity derives from widespread IHE rankings, which lack contextual and relational features for understanding the patterns of engagement in the fast-moving attention economy, and in particular how institutional partnerships can generate brand equity by leveraging ecosystem network effects. To this end, here we develop a framework for measuring two dimensions of brand equity, namely visibility, and association, according to the frequency of digital media articles featuring a university’s official name. We demonstrate this approach for 29 universities in California and Texas based upon 2 million media articles published between 2000 and 2020 and validate our approach by correlating university digital media visibility with ARWU Shanghai rankings and freshman enrollment growth. As roughly 10% of the article sample features >1 university, longitudinal analysis of institutional co-occurrence reveals the extent to which brand association stratifies according to regional proximity, institutional specialization, and prestige. Interestingly, despite the shared value generated from media co-visibility, the frequency of multi-university media articles has declined over time, which we attribute to paradigm shifts in media content production following the 2007–08 financial crisis and the COVID-19 infodemic, in addition to increased competitiveness of the attention economy. Topic classification of media article titles shows how specialized institutions may strategically manage their brand equity by aligning content production with dominant media topics to reinforce brand visibility with broader social, technological, and environmental narratives.
Temperature dependence of charge surface instability in liquid helium
Authors: Buntar’ V. A. , Kirichek O. I.
Published: February 2025

The instability of the charged liquid helium surface is investigated experimentally in the case of partial compensation of the confining electric field by the surface electron layer. The experiments reveal an unexpectedly strong temperature dependence of the critical confining field at which the breakdown of the liquid 4He surface is observed.
The effect of electron exchange on NMR spectra of impurity complexes due to nonisovalent substitutions or nonstoichiometry
Authors: Kovtun N. M. , Mitrofanov V. Ya. , Prokopenko V. K. , Fishman A. Ya. , Shemyakov A. A.
Published: February 2025

The spectral distribution of NMR frequencies of 3d-ions of a mixed valence is investigated in impurity complexes of a magnetically ordered crystal. It is shown that peculiarities of these spectra are due to the effects of spin density averaging. The effect of electron exchange on the NMR spectrum of chromium ions in Cd1–xInxCr2Se4 is studied experimentally, and the obtained results are interpreted by using the developed theory.
Critical parameters and electrochemical control of oxygen stoichiometry in YBa2Cu3O7–δ
Authors: Koshkin V. M. , Lyubomirskii I. V. , Ovechkina E. E. , Zaporozhskii V. D. , Mil’ner A. P.
Published: February 2025

The change in the critical parameters of YBa2Cu3O7–δ samples subjected to oxidation-reduction electrochemical treatment is studied. It is shown that the kinetics of electrochemical processes is determined by a rapid diffusion of oxygen at the grain boundaries of the ceramic
X-ray investigations of solid normal deuterium
Authors: Shcherbakov G. N.
Published: February 2025

The results of x-ray investigations of polycrystalline samples of n-D2 in the region of its existence in the solid state are presented. Lattice parameters, the molar volume, and the thermal expansion coefficient are measured, and several thermo-dynamic parameters are calculated for normal deuterium. It is shown that at temperatures above 10 K, the expansion of n-D2 crystals is highly anisotropic. The contribution of the rotational subsystem to the thermal expansion of solid n-D2 is determined.
Quantum galvanomagnetic effects in a nondegenerate two-dimensional electron gas at liquid helium surface
Authors: Monarkha Yu. P.
Published: February 2025

The longitudinal conductivity of a two-dimensional electron layer at the helium surface is investigated theoretically in the presence of a quantizing magnetic field normal to the liquid-vapor interface. It is shown by using Kubo’s expression for σxx and a semielliptical shape for the density of states that the electron-ripplon scattering in the low-temperature region may cause a peak on the temperature dependence of longitudinal conductivity and magnetoresistance. The obtained results help in explaining the experimentally observed low-temperature anomalies in the magnetoresistance of surface electrons in helium.
Ions in superfluid 3He–4He solutions
Authors: Kovdrya Yu. Z.
Published: February 2025

The earlier data on the mobility of positive and negative ions in 3He–4He solutions are analyzed for a wide range of temperatures and 3He concentrations. The most typical peculiarities of ion transfer in the solutions are established. It is shown that the radius R+ of positive ions, determined from the mobility of ions in the hydrodynamic region slightly increases with decreasing temperatures, passes through a peak at T ≲ Tλ, and then starts decreasing; the value of R+ also decreases with increasing concentration of the solution. It is found that the mobility of positive ions in the kinetic region, which is determined by scattering at 3He atoms, decreases at relatively high temperatures due to the localization of rotons near an ion as a result of a decrease in the roton energy gap and an increase in the effective cross section of scattering by the 3He impurity. At low temperatures, the mobility of negative ions corrsponding to the same concentration decreases with decreasing temperature and with increasing concentration due to a decrease in the range of scattering of a negative ion at the 3He impurity as a result of the condensation of several layers of 3He atoms on the surface of an electron bubble.
Spin injection in superconductors with paramagnetic impurities
Authors: Kosov A. A.
Published: February 2025

The equations of nonequilibrium spin kinetics for a tunnel junction between a ferromagnet and a superconductor with paramagnetic impurities are derived by using the microscopic theory. It is shown that the frequency of an NMR signal in a superconductor with spin injection strongly depends on the effectiveness of scattering of quasiparticles by magnetic impurities. The possibility of investigating the spin-orbit and exchange mechanisms of electron scattering by magnetic impurities as well as other parameters of the conduction band by using the dependence of the NMR frequency on the voltage across the junction is considered.
Nonlinear fluctuations of the order parameter and paraconductivity suppression in a magnetic field
Authors: Sergeeva G. G. , Chechkin A. V.
Published: February 2025

The expressions for the transverse and longitudinal components of the Aslamazov-Larkin fluctuational conductivity (paraconductivity) are obtained by taking into account the nonlinear interaction of fluctuations for layered HTS in a magnetic field H∥c. The introduction of the nonlinear interaction makes it possible to describe satisfactorily (i.e., without a fitting factor) the observed temperature dependence of resistivity in a magnetic field above Tc
Hall effect in one-dimensional quantum interferometer
Authors: Zagoskin A. M.
Published: February 2025

The transverse (Hall) resistance of a one-dimensional quantum interferometer is calculated in the field of vector potential, the resistance depending periodically on the magnetic flux (with period Φ0 = hc/e). The relevant contribution to the Hall coefficient of small samples (which is determined by their geometry and position of impurities) may lead to a considerable difference from the value of the Hall coefficient measured in bulk conductors.
Resistance oscillations in thin monocrystalline bismuth–tin threads under tensile strain
Authors: Bodyul P. P. , Garabazhiu V. F. , Kondrya E. P. , Nikolaeva A. A.
Published: February 2025

An oscillating dependence of the resistance of thin (d <2 μm) cylindrical Bi–0.03 at.% Sn single crystals at 4.2 K on the tensile strain is observed, the dependence being determined by the sample diameter, temperature and impurity concentration. An analysis of the nonmonotonic behavior of the resistance of thin samples is based on the idea of size-quantized spectrum of charge carriers and a noticeable variation of the exchange carrier concentration induced by impurities under a tensile strain.
Low-frequency magon absorption in α-oxygen
Authors: Pritula I. M. , Fugol’ I. Ya. , Khashchina L. V.
Published: February 2025

Far-infrared spectroscopic data on the low-frequency magnon M1 in α-oxygen are considered. The dependences of M1 intensity on the temperature and thickness of the sample are measured. The temperature shift in the M1 frequency is determined for the first time. It is shown that the shift over the entire temperature range between 9 and 23 K can be described only taking into account the dependences of exchange interaction on intermolecular spacing as well as on the libration value.
Raman scattering by low-energy electronic excitations of Fe2+ ion in ferrous fluosilicate
Authors: Gnezdilov V. P. , Eremenko V. V. , Peschanskii A. V. , Fomin V. I.
Published: February 2025

The results of experimental investigations of the lowest electronic excitation spectrum of Fe2+ ions in FeSiF6·6H2O crystal are presented. The lines corresponding to electronic transitions at 9.9, 14.0, and 47.6 cm−1 are detected by the Raman scattering method. The effect of an external magnetic field is studied and the low-energy levels of Fe2+ are found to be sensitive to the field orientation relative to the trigonal crystal axis.
Magnetic properties of cobalt orotate
Authors: Zvyagin A. I. , Kaplienko A. I. , Kobets M. I. , Mitkevich V. G. , Stepanov A. A. , Tret’yak S. M. , Khats’ko E. N.
Published: February 2025

The magnetic properties of cobalt orotate single crystals are investigated and the crystallographic structure of the material is decoded. It is found that in the temperature region 2–20 K, cobalt orotate is a paramagnet with a considerable anisotropy of susceptibility. The values of energies of six Kramers doublets corresponding to the lower level of the Co ion are determined by using the crystal field model together with the crystal field constants corresponding to the experimental set of g-factors.
Thermal conductivity of solid hydrogen with neon impurity
Authors: Gorodilov B. Ya. , Korolyuk O. A. , Zholonko N. N. , Tolkachev A. M. , Ezhovski A. , Belyaev E. Yu.
Published: February 2025

Results of measurements of thermal conductivity of parahydrogen crystals with neon atom impurity concentration of 0.02 and 0.0045% in the temperature interval 1.5–10 K are presented. The thermal conductivity of impurity crystals is compared with that of a specially prepared and investigated parahydrogen crystal containing 0.05% of the orthomodification. It is found that the thermal conductivity of crystals decreases by more than two orders of magnitude upon the introduction of the impurity. The curves of additional thermal resistance associated with the introduction of the neon impurity have a clearly manifested peak near 4 K which is displaced upwards on the temperature scale with increasing concentration.
Anomalous magnetoresistance of metals
Authors: Peschanskii V. G. , Lopes R. J. A.
Published: February 2025

It is shown that the resistance of metals with a nonconvex Fermi surface can be a complex function of a strong magnetic field due to a slow motion of charge carriers near the points of self-intersection of electron orbits in the momentum space.
Contact spectroscopy of high-temperature superconductors (a review). Part I. Physical and methodical foundations for contact spectroscopy of high-temperature superconductors. Experimental results for La2−xSrxCuO4 and their discussion
Authors: Yanson I. K.
Published: February 2025

An attempt is made to systematize the investigations of high-temperature superconductors by tunnel and point-contact spectroscopy. The main theoretical concepts forming the basis of the method are described. Various types of contacts are briefly discussed and classified. Departures of the current–voltage characteristics (IVC) from the predictions of the simplest theoretical models and observations in traditional superconductors are discussed. Special emphasis is laid on the properties of point contacts with a direct conductivity. The results of measurements of the energy gap and fine structure of IVC derivatives in the energy range beyond the gap for the high-Tc La2−xSrx CuO4 are reviewed.
Thermal conductivity of a YBa2Cu3O7−x single crystal in the temperature interval 2–300 K
Authors: Bondarenko A. V. , Gavrenko O. A. , Merisov B. A. , Obolenskii M. A. , Sologubenko A. V. , Khadzhai G. Ya.
Published: February 2025

The thermal conductivity λ(T) in the basal plane of a YBa2Cu3O7−x single crystal is studied in the temperature interval 2−300 K. In the temperature range 2−12 K, λ(T) is found to be proportional to T. Such a temperature dependence is associated with heat transport by flexural vibrations. The thermal conductivity peak lies in the region of 50 K. The superconducting transition (Tc = 90 K) results mainly in the emergence (or vanishing) of the electron contribution to heat transport. At higher temperatures, nonmonotonicities are observed in the temperature dependence of thermal conductivity. In all probability, these nonmonotonicities are associated with phase transitions. In the interval 200−300 K, the thermal conductivity of the single crystal is independent of temperature.
Surface spin waves in Heisenberg ferromagnets (a review)
Authors: Petrova T. G. , Syrkin E. S.
Published: February 2025

The properties of localized surface states in the one-magnon spectrum of Heisenberg ferromagnets with different types of lattices and exchange interactions are considered. The systems with “isotropic” as well as “anisotropic” exchange interaction are investigated. The case of “anisotropic” exchange determined by the long-range interaction between the spins arranged along a crystallographic axis is analyzed. The dispersion relations and damping decrements of localized surface waves are obtained without using the cumbersome apparatus of Green’s functions for simple and complex ferromagnets with “isotropic” exchange between nearest neighbors. The contribution of the surface to the magnon energy distribution function is determined. Spin-wave states localized at two-dimensional defects (like a free surface, foreign plane in an infinite lattice, or the boundary between two magnetic crystals are investigted for systems with a long-range exchange interaction. The long-range interaction is found to be essential for an analysis of stability of the ferromagnetic ordering in the defect plane in the case of alternating ferro- and antiferromagnetic “anisotropic” interaction. Surface-projectable spectral densities of one-magnon states are estimated.
On anisotropy of resistance in the basal plane of YBa2Cu3Ox single crystals in a magnetic field
Authors: Bondarenko A. V. , Dmitrenko I. M. , Obolenskii M. A. , Fogel’ N. Ya. , Cherkasova V. G.
Published: February 2025

Resistive transitions are investigated for different orientations of a magnetic field in the ab plane for orthorhombic YBaCuO single crystals with twins. It is shown that the anisotropy of resistance in the basal plane observed for such single crystals can be explained in analogy with resistance anisotropy induced by a magnetic field in HTS polycrystals. This anisotropy is a consequence of anisotropy in the conductivity and field Hc2 in the ab plane due to the presence of highly conducting CuO chains in orthorhombic crystals. In view of peculiarities in its symmetry, the observed anisotropy cannot be explained by the effect of twinning planes or magnetic flux creep. Single crystals with a low oxygen content containing no chains do not exhibit any anisotropy or R in the basal plane.
Percolation-localization crossover near a metal–nonmetal transition in cold-deposited thin-film sodium-formamide condensates
Authors: Moshenskii A. A. , Spasova M. A.
Published: February 2025

The metal-nonmetal transition in cold-deposited thin-film sodium-formamide condensates is investigated. The transition mechanism is determined by the superposition of localization and percolation effects. The metal-nonmetal transition in these systems is characterized by percolation-localization crossover.
On the increase in the critical parameters of heterophase superconductors during their cyclic treatment by an external magnetic field
Authors: Boiko V. S. , Obolenskii M. A. , Chashka Kh. B.
Published: February 2025

The effect of a magnetic field on the behavior of heterophase superconducting systems, viz., the systems in which the superconducting and the normal phase or phases with different superconducting transition temperatures coexist, is considered. The stresses acting in an external magnetic field on a transformation dislocation at the interface between two phases may lead to a displacement of the dislocation along the phase boundary. This can be accompanied by an increase in the volume fraction of the superconducting phase and in the superconducting parameters of a heterophase sample on the whole. Such assumptions are put forth for explaining the experimental results obtained during investigations of a heterophase superconductor NbSe2-hydrogen. Upon a cyclic treatment of this superconductor by an external magnetic field at temperatures below the superconducting transition temperature, the critical parameters Tc, Hc, and Jc of the superconducting state increase.
Magnetization studies in YBa2Cu3O7–x ceramic
Authors: Gamtsemlidze G. A. , Bibiluri D. I. , Gamkrelidze K. P. , Mirzoeva M. I. , Sharikadze L. A. , Shoniya G. K.
Published: February 2025

The ballistic method is used to study the behavior of magnetization of a YBa2Cu3O7–x ceramic sample as a function of the external field, past history, and temperature. The experimental data are interpreted by using the vortex model.
Raman spectroscopy in the crystal CsMnCl3·2H2O
Authors: Gnezdilov V. P. , Eremenko V. V. , Kurnosov V. S. , Fomin V. I.
Published: February 2025

Low-temperature polarized Raman spectra of the quasi-one-dimensional chain antiferromagnet CsMnCl3·2H2O are studied. The fundamental vibration frequencies of the crystal in the interval 0–350 cm−1 are determined. Group theory analysis of the vibrational modes of the crystal lattice is carried out, and a partial assignment of the observed lines is made. A weak temperature-dependent asymmetric wide band is observed and attributed to the two-magnon scattering of light in CsMnCl3·2H2O.
Magnetoresistance of a two-dimensional electron layer over liquid helium at temperatures below 1 K
Authors: Grigor’ev V. N. , Kirichek O. I. , Kovdrya Yu. Z. , Sokolov S. S.
Published: February 2025

The longitudinal magnetoresistance ρxx of the surface electron (SE) layer over liquid helium is measured in magnetic fields up to 6 kOe at temperatures T up to 0.4 K. It is shown that the dependence ρxx(T) in a constant magnetic field is in the form of a curve with a maximum and a minimum. Such a behavior of ρxx is in agreement with the theoretical concepts developed by Yu. P. Monarkha [Fiz. Nizk. Temp. 17, 146 (1991)] and is attributed to the quantum nature of charge movement in the liquid–vapor interface under conditions of competition of gas and rippion mechanisms of SE scattering.
Effect of anisotropic deformations on the frequency of “high-temperature” magnetoresistance oscillations in bismuth
Authors: Krasovitskii Vit. B. , Khotkevich V. V.
Published: February 2025

The effect of anisotropic compressive strain along the principal crystallographic directions on the frequencies of high-temperature oscillations (HTO) and Shubnikov-de Haas oscillations of the magnetoresistance of bismuth single crystals is studied experimentally. The obtained results are interpreted in the framework of theoretical concepts according to which the HTO are associated with intervalley quasielastic scattering of charge carriers at the band edges.
Long-range impurity states and insulator–metal transition in 2D- and quasi-3D systems
Authors: Ivanov M. A. , Loktev V. M. , Pogorelov Yu. G. , Skripnik Yu. V.
Published: February 2025

The theory of collective rearrangement of a spectrum, which was developed earlier for weakly doped 3D crystals, is generalized to the case of 2D systems. The spectrum and density of states of a 2D semiconductor doped with impurities creating a local level near the edge of the unperturbed band are analyzed by using the single-site perturbation model. It is shown that an incoherent rearrangement of the spectrum takes place in the model, but the insulator-metal transition for high concentrations of doping impurities is ensured by a relatively small capacity of the electron reservoir of the 2D system as compared to the 3D case. The applicability of the model for describing metallization in high-temperature superconductors is considered.
Low-temperature heat capacity of antiferromagnetic GdCu
Authors: Kourov N. I. , Tsiovkin Yu. N.
Published: February 2025

The heat capacities Cp(T) of antiferromagnetic compounds GdZnxCu1−x (x = 0, 0.02, 0.05, 0.07, 0.1, 0.2) and their “nonmagnetic analog” LaCu are measured in the temperature interval 2−30 K. It is shown that structural and magnetic instability of GdCu-based compounds is associated with the presence of a narrow peak in the density of states near the Fermi level due to hybridization effects.
The structure of YBa 2Cu 3O7−δ epitaxial films on LaAIO3 substrates
Authors: Arinkin A. V. , Palatnik L. S. , Stetsenko A. N. , Fedorenko A. I. , Fuks G. I. , Chirkin A. N. , Elyutin A. V. , Knyazev S. N. , Ponomarev N. M.
Published: February 2025

The structure of YBa2Cu3 O7−δ epitaxial layers on (111) LaAlO3 substrates is studied by x-ray diffraction methods. The films are characterized by the presence of three mutually perpendicular domains oriented so that the c-axis is directed along (100)-type directions in the substrate. An analysis of reflection positions reveals a tensile strain ε≃ 1.2 10−3 of the film, which is due to thermal stresses up to 220 MPa in the film–substrate system.
Superconducting current in the bisoliton model of superconductivity
Authors: Ermakov V. N. , Kruchinin S. P. , Ponezha E. A.
Published: February 2025

It is shown that the superconducting transition described by the bisoliton model of superconductivity involves spectral deformation of one-particle states of charge carriers. The deformation is proportional to the superconducting current. The residual resistance is absent in such states.
Effect of uniaxial pressure on the critical parameters of Sn-doped NbSe2
Authors: Chashka Kh. B. , Beletskii V. I. , Obolenskii M. A. , Poltoratskii Yu. B.
Published: February 2025

X-ray structural investigations of sintered single crystals of Sn-doped NbSe2 are reported. The elemental composition and the electronic structure are studied by x-ray photoelectronic spectroscopy. The effect of uniaxial pressure applied at right angles to the plane of crystal layers on the superconducting transition temperature and upper critical fields is studied. It is shown that Tc(p) is a nonmonotonic function of pressure. The results of investigations are used for calculating the microscopic characteristics, and the mean free path and coherence length are determined. An increase in the uniaxial pressure increases the Fermi velocity in the layer plane. The reasons behind the observed behavior of superconducting parameters are discussed.
Tunnel effect in contacts on a microcrack in Bi–Sr–Ca–Cu–O:Pb
Authors: Brandt N. B. , Broide E. L. , Givargizov M. E. , Pedyash M. V. , Petrov D. K. , Ponomarev Ya. G. , Rakhimov Kh. T. , Setupathi K. , Sudakova M. V. , Tennakun A. B. , Shevchenko A. D.
Published: February 2025

A comparative experimental investigation of current–voltage characteristics of contacts on a microcrack is carried out in ceramic samples of Bi–Sr–Ca–Cu–O:Pb (2:2:1:2-phase) with a large (L∼50 μm) and small (L ∼ 1 μm) grain size and Tc = 86 K. The Dynes method is used for calculating the gap parameter Δ(0) (2Δ(0)/kTc – 5.8), which is found to be in a fairly good agreement with the results obtained by other authors. The temperature dependence Δ(T) of the gap parameter in relative coordinates is in agreement with the formal BCS theory.
Manifestation of universal properties of glasses in solid solutions of diatomic molecules in crystals of inert gases
Authors: Burin A. L.
Published: February 2025

The low-temperature properties of the “glass-like” phase of solid solutions of molecules with rotational degrees of freedom in crystals of inert gases are studied theoretically. The temperature and concentration dependences of heat capacity obtained in the temperature range T ∼ 1 K are in qualitative agreement with experiments. A qualitative coincidence of the properties of the system with the properties of ordinary glasses is predicted for the range of ultralow temperatures T ≪ 1 K.
Isochoric thermal conductivity of solid CHCI3 and CH2CI2. The role of rotational motion of molecules
Authors: Konstantinov V. A. , Manzhelii V. G. , Smirnov S. A.
Published: February 2025

The isochoric thermal conductivity and thermal pressure of solid chloroform and methylene chloride are studied near the melting temperature. The connection between the temperature dependence of thermal conductivity and the nature of rotational motion of molecules is discussed.
Effect of hafnium doping on the phase composition and superconducting characteristics of yttrium-based ceramics
Authors: Braude I. S. , Khomenko V. G. , Sorin M. N. , Chaikovskaya N. M. , Vasil’chenko S. A. , Dotsenko V. I.
Published: February 2025

The possibility of synthesizing a ceramic with composition Y1Ba2Cu3–xHfx O7–δ (0 ≤ x ≤ 2) is investigated. The synthesis was carried out by using oxides according to standard ceramic technology. The material was annealed for six hours at a temperature of 945 °C. The obtained samples were used for x-ray and magnetic measurements. The x-ray structural analysis showed that for a hafnium concentration x ≤ 0.2 the samples contain the standard rhombic phase (1–2–3) and the “green phase” (not more than 10%). An increase in the hafnium concentration leads to the emergence of two new phases, viz., BaHfO3 and Ba2HfO4, whose amount increases considerably with increasing x. The superconducting transition temperature (dynamic susceptibility measurements) decreases from 91 K (initial ceramic) to 82.3 (for x = 1.0). For higher Hf concentrations, a superconducting transition in the samples is not observed.
Rate of flow of bcc crystals of 4He through a porous membrane
Authors: Dyumin N. E. , Zuev N. V. , Svatko S. V. , Grigor’ev V. N.
Published: February 2025

Results of measurements of the flow rate of helium through a porous membrane are used to obtain information about the coefficient of atomic self-diffusion and vacancy diffusion in bcc 4He. The diffusion processes are isotropic and can be treated as thermally activated under the assumption of a monovacancy mechanism. The entropy of self-diffusion activation, the enthalpy of vacancy formation, and the height of the potential barrier are estimated.
Topological transitions in normal metals (a review)
Authors: Kaganov M. I. , Gribkova Yu. V.
Published: February 2025

The complex geometrical structure of the Fermi surfaces of metals is responsible for the existence of various anomalies in the behavior of metals under extremal conditions, e.g., at low temperatures, in strong magnetic fields, during propagation of shortwave acoustic signals, and under high pressures. Many properties of metals can be put in correspondence with the geometrical structures connected with the Fermi surface, namely, the extremal cross-section, diameters of the extremal length, and “belts” in which the normal to the Fermi surface is orthogonal to a certain direction. The nature of the anomaly is determined by the variation of these geometrical structures under the action of external factors. Such anomalies are called topological transitions.
Theory of energy relaxation in a two-dimensional electronic crystal at liquid helium surface
Authors: Monarkha Yu. P. , Shikin V. B.
Published: February 2025

A theory of energy relaxation in a two-dimensional Wigner crystal at the free liquid helium surface is constructed. The energy relaxation time of surface electrons is calculated by using the self-consistent theory of coupled, phonon-ripplon modes for describing the dynamic form factor of the crystal. It is shown that this time is determined by processes in which a transverse phonon of the two-dimensional lattice is transformed into a pair of short-wave ripplons. The theory is compared with the available experimental results.
Collective pinning of vortex lines in amorphous Nb3Ge films
Authors: Prokhorov V. G. , Kaminskii G. G. , Tret’yachenko K. G.
Published: February 2025

Resistive measurements have been made for the critical current density as a function of the magnetic field in amorphous Nb3Ge films obtained by simultaneous evaporation in vacuum. The dominant role of plastic deformation of the vortex lattice on bulk pinning force in strong magnetic fields is shown. Some films prepared by a special technique reveal the existence of a mixed pinning state, as well as a crossover from one-particle interaction to a collective interaction of the vortex lattice with defects.
Atomic ordering in the normal and superconducting state characteristics of YBa2Cu3Ox HTS oxides
Authors: Sukharevskii B. Ya. , Zhikharev I. V. , Khokhlova S. I. , Shatalova G. E. , Duka A. Ya. , Tsybul’skii E. O. , Mikheenko P. N.
Published: February 2025

It is shown that when YBa2Cu3Ox ceramic samples with an initial value x = 6.86 are heated to temperatures in the interval 200–450 °C, held under isothermal conditions, and quenched, the ratio of oxygen to vacancy concentration in the CuOx-6 plane changes and this results in the formation of ordered states for x = 6.83, 6.80, 6.75, and 6.67. The ordering can be seen clearly in the dependences P(x) of the superconducting phase volume and σ(x) of room-temperature conductivity. The correlation between these characteristics enables us to substantiate the concepts about the superconducting cluster with a nearly ordered structure and a carrier concentration close to the value corresponding to the filling of an integral number of bands.
Magnetic susceptibility of multiconnected Josephson systems in a weak varying field
Authors: Demin A. V. , Khlus V. A.
Published: February 2025

Magnetic properties of granular superconducting systems in a weak varying magnetic field are considered. A model is used in which the existence of closed loops with weak couplings formed by granules is presumed. The periodicity condition for the superconducting order parameter leads to the existence of a family of stable energy states and saddle points in the phase space of the system. The dynamics of thermally activated transitions through the barriers separating adjacent stable states is investigated. The imaginary component χ″(ω) of the magnetic susceptibility is calculated for different temperatures and amplitudes of the varying magnetic field.
Prevalence and Mortality Trends of Hypertension Subtypes Among US Adults: An Analysis of the National Health and Nutrition Examination Survey
Authors: Tang Kevin S , Jones Jeffrey E , Fan Wenjun , Wong Nathan D
Published: February 2025

BACKGROUND

Hypertension (HTN) has been demonstrated as one of the leading risk factors for development of cardiovascular disease (CVD) and CVD mortality.

METHODS

This study examines the prevalence and distribution of HTN subtypes (isolated diastolic hypertension [IDH], isolated systolic hypertension [ISH], and systolic-diastolic hypertension [SDH]) across age, sex, and race/ethnicity per the nationally representative National Health and Nutrition Examination Survey (NHANES) from 1999 to 2020 based on the updated 2017 ACC/AHA HTN definition. We further examined for associations of each subtype with CVD and all-cause mortality using Cox regression analysis.

RESULTS

Among US adults, the overall prevalence of HTN is 47.4%. Across increasing age, the prevalence of IDH decreased, ISH increased, and SDH increased and peaked in the 6th decade of life after which SDH prevalence decreased. By age 80, over 80% of persons with HTN demonstrated ISH. A subcohort from NHANES 1999–2008 with follow-up until 2018 showed that ISH and SDH were most strongly associated with increased risk for CVD (HR = 1.18, 95% CI, 1.01–1.38; HR = 1.31, 95% CI, 1.07–1.60, respectively) and all-cause mortality (HR = 1.17, 95% CI, 1.06–1.28; HR = 1.21, 95% CI, 1.08–1.37, respectively).

CONCLUSIONS

Our data demonstrate the continuing importance of HTN subtype transitions across age and their differences in predicting future CVD and total mortality.