bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparative effects of gong’s mobilization and mobilization with movement in patients with adhesive capsulitis: a randomized clinical trial
Authors: Amjad Fareeha , Asghar Hasha
Published: February 2025

Adhesive Capsulitis results in a progressive contraction of the Glenohumeral joint capsule limiting active and passive range of motion, leading to functional disabilities. Joint mobilization plays a key role in the physical therapy treatment of Adhesive Capsulitis. A relatively new technique, Gong’s Mobilization, has been introduced for the treatment of Adhesive Capsulitis. It is focused on the correction of positional faults through controlled dynamic motion of the Glenohumeral joint. The mainstay of this clinical trial is a comprehensive comparative evaluation of MWM with Gong’s Mobilization as it remains insufficiently explored. The objective of this clinical trial was to compare the effects of Gong’s Mobilization and Mobilization with Movement on pain, range of motion and functional disability in patients with Adhesive Capsulitis. In this triple blinded randomized clinical trial, sixty patients of Adhesive Capsulitis were enrolled within group A (Gong’s Mobilization) and group B (Mobilization with Movement). The treatment protocol covered 12 treatment sessions for 4 weeks. Numeric Pain Rating Scale (NPRS), Goniometer, and Urdu version of Shoulder Pain and Disability Index (U-SPADI) were used to assess the pain, range of motion and functional status respectively. These outcome measures were assessed at baseline, after 6 treatment sessions (2 weeks) and conclusively after 12 treatment sessions (4 weeks). For data analysis, within the group differences were measured by Repeated Measure ANOVA and across the group differences were measured by independent t test. A significant difference within the mean values of baseline, week 2 and week 4 NPRS, ROM, and SPADI score was observed in both study groups (p < 0.001). Results of independent t test used to calculate across the group differences indicated that Gong’s Mobilization was more effective in reducing disability (SPADI)(p < 0.001) and improving ROM(p < 0.001), meanwhile both groups were equally effective in reducing NPRS scores(p = 0.78). Moreover, a medium to large effect size was also observed for all the outcomes, pain(d = 0.5), ROM (d = 0.5–2.7), SPADI(d = 0.5). It was concluded that Gong’s Mobilization is more effective than Movement with Mobilization. Following four weeks of treatment, it pronounced statistically significant and clinically relevant results in improving pain, ROM and functional status of patients with Adhesive Capsulitis.

Trial Registration Trial was registered in IRCT (Trial registration number: IRCT20190717044238N4 Trial Registration Date: 01-03-2023).
The unskilled-and-unaware problem and performance feedback in monotonous, easily accustomed, and repetitive work
Authors: Nakamoto Yasuhiro , Mori Tomoharu
Published: February 2025

The current research examined whether people predict their performance on monotonous, easily accustomed, and repetitive (MEAR) tasks accurately and confirm the effects of performance feedback on their MEAR work predictions. Considering typing on the keyboard as an MEAR task in modern society, 128 university students were asked to type a 12-digit number displayed on each monitor within 5 minutes, explaining that there would be 75 typing problems and participants would receive 20 yen per correct answer. Additionally, participants were informed that they could earn money by reaching a self-determined performance target, with the condition that if they did not reach their self-set goal, they would not receive any earnings. The main findings were as follows: Regardless of the performance levels of typing on keyboards, only 23% of the participants reached the goal, indicating that the absence of performance feedback led to individuals’ overestimation of performance. In contrast, providing feedback significantly improved performance predictions: 76% of the participants reached the goal with feedback on their own performance, 70% with feedback on others’ performance, and 88% with feedback on both their own and others’ performance information. Specifically, the effects between one’s own and others’ performance feedback did not vary at statistically significant levels.
Socio-demographic disparities in global trends of lip and oral cavity neoplasms from 1990 to 2021
Authors: Ghanem Amr Sayed , Tóth Ágnes , Nagy Attila Csaba
Published: February 2025

Oral cancer, the 13th most common globally, is primarily squamous cell carcinoma linked to tobacco, alcohol, and HPV. Despite advances in care, it remains a major health concern due to high mortality and its impact on quality of life. This study analyzed socio-demographic disparities in oral cancer burden using data from 1990 to 2021. We analyzed annual incidence, mortality, and DALYs across 204 countries, using age-standardized rates and the Socio-demographic Index (SDI) to assess development-related impacts. Statistical methods included Kruskal–Wallis tests, linear regression, joinpoint regression for trends, and Exponential Smoothing for forecasts (2022–2030), with analyses conducted in STATA and Python, and p < 0.05 as significant. Incidence was highest in high SDI countries, while mortality and DALYs were highest in low and middle SDI countries (p < 0.001). From 1990 to 2021, incidence increased (AAPC: 0.5–1.0%), while mortality (APC: − 0.5%) and DALYs (APC: − 0.6%) declined in low SDI regions. Significant disparities across SDI categories (p < 0.001) showed incidence rising with socio-demographic development (R2 = 0.102, p < 0.001), with high-middle SDI regions bearing the highest mortality and DALYs. These findings highlight the need for awareness, prevention, early detection, and accessible care, especially in lower SDI regions.
A microscale thermophoresis-based enzymatic RNA methyltransferase assay enables the discovery of DNMT2 inhibitors
Authors: Nidoieva Zarina , Sabin Mark O. , Dewald Tristan , Weldert Annabelle C. , Hoba Sabrina N. , Helm Mark , Barthels Fabian
Published: February 2025

RNA methyltransferases (MTases) have recently become increasingly important in drug discovery. Yet, most frequently utilized RNA MTase assays are limited in their throughput and hamper this rapidly evolving field of medicinal chemistry. This study developed a microscale thermophoresis (MST)-based split aptamer assay for enzymatic MTase investigations, improving current methodologies by offering a non-proprietary, cost-effective, and highly sensitive approach. Our findings demonstrate the assay’s effectiveness across different RNA MTases, including inhibitor characterization of METTL3/14, DNMT2, NSUN2, and S. aureus TrmD, enabling future drug discovery efforts. Using this concept, a pilot screening on the cancer drug target DNMT2 discovered several hit compounds with micromolar potency.
Dietary changes are associated with an increase in air pollution-related health and environmental inequity in China
Authors: Luo Biao , Huang Jianwei , Liu Xueying , Kwan Mei-Po , Tai Amos P. K.
Published: February 2025

Agriculture is an important contributor to air pollution and its health impacts, with ramifications for environmental and health inequity. A substantial fraction of these effects can be attributable to dietary changes, but the extent of such impacts remains unclear. Here we show that the PM2.5-related mortality attributable specifically to dietary changes and the associated rising agricultural emissions has a high Gini coefficient of 0.369 in China in 2010, and raises the Gini coefficient of all-cause PM2.5-related mortality from 0.189 to 0.197 with more uneven allocation among income groups, reflecting worsened health inequity and an export of pollution from richer coastal regions to poorer agricultural regions via food trade. Such mortality is associated positively with urbanization but negatively with green space and healthcare quality. Our results also provide empirical evidence for the environmental Kuznets curve hypothesis, and offer decision support for equitable clean air, food and health policies in China.
Integrated photonic programmable random matrix generator with minimal active components
Authors: Zelaya Kevin , Honari-Latifpour Mostafa , Miri Mohammad-Ali
Published: February 2025

Random matrices are fundamental in photonic computing because of their ability to model and enhance complex light interactions and signal processing capabilities. In manipulating classical light, random operations are utilized for random projections and dimensionality reduction, which are important for analog signal processing, computing, and imaging. In quantum information processing, random unitary operations are essential to boson sampling algorithms for multiphoton states in linear photonic circuits. Random operations are typically realized in photonic circuits through fixed disordered structures or through large meshes of interferometers with reconfigurable phase shifters, requiring a large number of active components. In this article, we introduce a compact photonic circuit for generating random matrices by utilizing programmable phase modulation layers interlaced with a fixed mixing operator. We show that using only two random phase layers is sufficient for producing output optical signals with a white-noise profile, even for highly sparse input optical signals. We experimentally demonstrate these results using a silicon-based photonic circuit with tunable thermal phase shifters and waveguide lattices as mixing layers. The proposed circuit offers a practical method for generating random matrices for photonic information processing and for applications in data encryption.
One-step synthesis of LYH:Tb and LYH:Eu film probes and their application in Bacillus anthracis recognition
Authors: Guo Yongping , Zeng Haoxuan , Chen Taihui , Wu Xiaoli
Published: February 2025

LYH:Tb and LYH:Eu film probes were prepared using the chemical bath method, which enhanced the fluorescence of Tb3+ and Eu3+ through energy transfer, enabling the visualization of the anthrax spore biomarker DPA.
Scalable copper current collectors with precisely engineered lithiophilic alloy “skins” for durable lithium-metal batteries
Authors: Wang Huiqun , Mao Yuxiang , Xu Peng , Ding Yu , Yang Huiping , Li Jian-Feng , Gu Yu , Han Jiajia , Zhang Li , Mao Bing-Wei
Published: February 2025

A lithiophilic copper-based alloy skin is fabricated on Cu current collectors via scalable ultrafast Joule heating. This skin enables uniform Li nucleation and dendrite-free growth, significantly improving cycling stability of Li-metal batteries.
Effect of protein texturization on amino acids and protein in vitro bioaccessibility of pea and rice protein
Authors: Peñaranda Irene , Garrido María Dolores , García-Segovia Purificación , Martínez-Monzó Javier , Igual Marta
Published: February 2025

The texturization process improved the functionality of pea and rice proteins, increasing their digestibility and accessibility, especially in pea. However, it decreased the bioaccessibility of certain essential amino acids, such as lysine.
Drug-loaded 3D-printed magnetically guided pills for biomedical applications
Authors: Myrovali Eirini , Chatzitaki Aikaterini-Theodora , Papadopoulos Kyrillos , Fatouros Dimitrios G.
Published: February 2025

A 3D-printed magnetically driven drug loaded magnetic pill for simultaneous heat generation and drug release within AC magnetic fields for the treatment of stomach cancer.
Dynamic bandgap modulation in CsPbBr3 perovskite nanocrystals through reversible ammonia intercalation
Authors: Fausia Karayadi H. , Nharangatt Bijoy , Muhsina Kavundath , Rappai John P. , Chatanathodi Raghu , Jose Deepthi , Sandeep Kulangara
Published: February 2025

Exposure to ammonia vapors on CsPbBr3-coated substrates results in the widening of a semiconductor's bandgap, which is reversible with time. The intercalation NH3-induced strain origins the bandgap widening.
New 8-hydroxyquinoline-based azo dyes as highly sensitive colorimetric chemosensors for nickel cation
Authors: Olaleye Sefiu Olalekan , Idowu Sunday Olakunle , Ahmed Shakil , Khan Maria Aqeel
Published: February 2025

A new series of sensitive 8-hydroxyquinoline azo-compounds (S1–S8) as sensors was synthesized by diazotization and diazo-coupling, and these compounds were characterized through UV, FTIR, 1H-NMR, 13C-NMR and ESI-MS investigations.
Development of a scalable and sustainable continuous-flow microreaction process for mononitration of aromatic compounds with high selectivity and yield
Authors: Xing Dong , Lei Xiangui , Fu Yufeng , Xu Zhijie , Luo Dengyun , Chen Jiujun , Xiang Yong , Wang Zhouyu , Song Qiao
Published: February 2025

This continuous-flow mononitration process for aromatic compounds features high yield and selectivity. It is easy to scale up, stable, and practical.
Origins of intrinsic p-type conductivity, p–n transition and substoichiometry in SrO
Authors: Liu Taifeng , Zhang Xingfan , Guan Jingcheng , Chen Xuebo , Lu You , Keal Thomas W. , Buckeridge John , Catlow C. Richard A. , Sokol Alexey A.
Published: February 2025

Formally charged double acceptors strontium vacancies prove to be the primary source of the hole excess over negative carriers supplied by donor species, contributing to the material's p-type conductivity.
XMM/HST monitoring of the ultra-soft highly accreting narrow-line Seyfert 1 RBS 1332
Authors: Middei R. , Barnier S. , Saturni F.G. , Ursini F. , Petrucci P.-O. , Bianchi S. , Cappi M. , Clavel M. , De Marco B. , De Rosa A. , Matt G. , Matzeu G.A. , Perri M.
Published: February 2025

Ultra-soft narrow-line Seyfert 1s (US-NLSy 1s) are a poorly observed class of active galactic nuclei characterised by significant flux changes and an extreme soft X-ray excess. This peculiar spectral shape represents a golden opportunity to test whether the standard framework commonly adopted for modelling local AGNs is still valid. We thus present the results of the joint XMM-Newton and HST monitoring campaign of the highly accreting US-NLSy RBS,1332. The optical-to-UV spectrum of RBS,1332 exhibits evidence for both a stratified narrow-line region and an ionised outflow that produces absorption troughs over a wide range of velocities (from ∼--1500 km s^-1 to ∼1700 km s^-1) in several high-ionisation transitions (Lyα, N V C IV ). From a spectroscopic point of view, the optical/UV/FUV/X-ray emission of this source is due to the superposition of three distinct components that are best modelled in the context of the two-coronae framework in which the radiation of RBS,1332 can be ascribed to a standard outer disc, a warm Comptonisation region, and a soft coronal continuum. The present dataset is not compatible with a pure relativistic reflection scenario. Finally, the adoption of the novel model reXcor allowed us to determine that the soft X-ray excess in RBS,1332 is dominated by the emission of the optically thick and warm Comptonising medium, and only a marginal contribution is expected from relativistic reflection from a lamppost-like corona.
Spatial and temporal super-resolution methods for high-fidelity solar imaging
Authors: Gugnin Olexandr , Wan Brian C.K. , Wong Charmaine S.M. , Ho Shirley
Published: February 2025

The Sun plays a significant role in space weather by emitting energy and electromagnetic radiation that influence the environment around the Earth. Missions such as SOHO, STEREO, and SDO captured solar observations at multiple wavelengths to monitor and predict solar events. However, the data transmission from these missions is often constrained, in particular, for those operating at greater distances from Earth. This limits the availability of continuous observations. We increase the spatial and temporal resolution of solar images to improve the quality and availability of solar data. By addressing telemetry constraints and providing more detailed solar image reconstructions, we seek to facilitate a more accurate analysis of solar dynamics and improve space weather prediction. We applied deep-learning techniques, specifically, a UNet-based architecture, to generate high-resolution solar images that enhance the intricate details of the solar structures. Additionally, we used a similar architecture to reconstruct solar image sequences with a reduced temporal resolution to predict missing frames and restore temporal continuity. Our deep-learning approach successfully enhances the resolution of solar images and reveals finer details of solar structures. The model also predicts missing frames in solar image sequences, which allows more continuous observation despite telemetry constraints. These advancements contribute to a better analysis of solar dynamics and set the stage for an improved space weather forecasting and future solar physics research.
Identification of differentiating sonographic features between fibroadenomas and malignant tumors of the breast mimicking fibroadenomas: 10-year experience in 421 histologically verified cases
Authors: Swoboda Michael , Deeg Johannes , Egle Daniel , Ladenhauf Valentin , Galijasevic Malik , Plöbst Christoph , Haushammer Silke , Amort Birgit , Pamminger Mathias , Gruber Leonhard
Published: February 2025

Ultrasound is a highly effective imaging tool for assessing abnormalities within the breast. However, especially the identification of malignant tumors of the breast mimicking fibroadenomas (MTMF) by means of breast ultrasound can be challenging. This study aimed to identify reliable imaging characteristics of MTMF.

This retrospective study was approved by the local ethics review board. After screening 623 patients, 421 cases with histologically verified fibroadenomas and MTMF between 2011 and 2021 were included. Sonographic features were compared to histopathological results and an algorithm-based quantitative ranking of predictors contributing most to the correct classification of malignant tumors was conducted.

A total of 363 benign, 18 intermediate, and 40 malignant lesions were analyzed. Algorithm-based quantitative ranking showed that the most predictive features indicating malignancy were a hyperechoic rim (gain ratio merit 0.135 ± 0.004), an irregular border (0.057 ± 0.002), perilesional stiffening (0.054 ± 0.002), pectoral contact (0.051 ± 0.003), an irregular shape (0.029 ± 0.001), and irregular vasculature (0.027 ± 0.002).

Ultrasound findings for fibroadenomas vary, making identification of MTMF challenging. Features such as indistinct margins and increased perilesional echogenicity are predictors for malignancy and should be considered during sonographic evaluation of fibroadenomas and MTMF.
SLEEP, CIRCADIAN RHYTHMS, AND LUNG CANCER
Authors: Cooper Daniel , Lopez Isaac , Kendzerska Tetyana
Published: February 2025

Lung cancer is the leading cause of cancer-related mortality worldwide, with the prevalence of the disease continually rising. Therefore, identifying disease-modifying risk factors is critical, with increasing recognition of the impact of sleep quality/sleep disorders. This narrative review summarizes the evidence on the role of five domains of sleep on lung cancer incidence and progression: (i) sleep quality/duration, (ii) sleep disordered breathing, (iii) circadian rhythm disturbances, (iv) sleep-related movement disorders and (v) personal, environmental and social factors that modulate each of these associations. Epidemiological evidence supports reduced sleep duration, increased sleep duration, poor sleep quality, insomnia, obstructive sleep apnea, evening chronotype, peripheral limb movements in sleep, and less robustly for night shift work and restless leg syndrome to be associated with increased risk of lung cancer development, with potential impacts on cancer survival outcomes. Proposed mechanisms underlying the biological plausibility of these epidemiological associations are also explored, with common theories relating to immune dysregulation, metabolic alterations, reductions in melatonin, sympathetic overactivation, increased reactive oxygen species, production of protumorigenic exosomes and inflammation. We also summarized potential treatments addressing impaired sleep quality/sleep disorders and their ability to attenuate the risk of lung cancer and cancer survival. While evidence on reversibility is inconsistent, there are trends toward positive outcomes. Future research should focus on clinical trials to confirm cause and effect relationships, large epidemiologic studies for incidence/prognosis, clarification on the relative efficacy of treatment modalities, and more in vivo animal models to establish the molecular mechanisms underlying these relationships.
LiClO4/EG as an Environmentally Benign Lewis Acidic Catalytic System for the Expeditious Synthesis of 2,3-Dihydroquinazolin-4(1H)-ones and NH-1,2,3-Triazoles
Authors: Chetia Swadhin , Sho Dimanta , Bora Pranjit Kumar , Dutta Apurba , yashmin Farnaz , Guha Ankur Kanti , Das Babulal , Konwar Manashjyoti , Sarma Diganta
Published: February 2025

An environmentally benign protocol has been developed for the synthesis of two biologically important N-heterocycles i.e. 2,3-dihydroquinazolin-4(1H)-ones and NH-1,2,3-triazoles. These two N-heterocyclic compounds are synthesized by readily available and inexpensive LiClO4 in ethylene glycol (EG) and PEG-400 with good to excellent product yield and providing an important benchmark for the rapid synthesis of these two heterocycles under operational simplicity. Sc-XRD of one of the products gives structural information and DFT calculations provide important information on mechanistic pathway.
Investigating the Role of Personalized Nutritional Counseling in Enhancing Oral Health Management: A Cross-Sectional Survey among Saudi Arabian Dental Practitioners
Authors: Parveen Sameena
Published: February 2025

Objectives This study evaluated Saudi Arabian dental practitioners' knowledge, practices, and perceptions regarding personalized nutritional counseling (PNC) and its integration into oral health management.

Materials and Methods A total of 207 dental practitioners in Saudi Arabia were the subjects of a cross-sectional survey.

The survey consisted of four sections: (1) knowledge and practices of PNC, (2) training and resources, (3) challenges and barriers, and (4) perceptions of the impact of PNC on oral health management. The data were stratified by age, gender, years of experience, specialization, and workplace setting.

Statistical Analysis Descriptive statistics were used to analyze the frequency of responses, and chi-square tests were performed to assess associations between demographic variables (e.g., gender, experience) and critical outcomes. A significance level of p <0.05 was considered statistically significant.

Results Out of 207 practitioners, most (80%) of respondents acknowledged the importance of nutrition in oral health, yet only 20% regularly provided nutritional counseling. Gender showed a significant association, with females more likely to consider dietary habits (72%, p = 0.003) and medical history (85%, p = 0.005) during counseling. Notably, confidence levels in nutritional counseling increased with experience, with those with more than 10 years of experience being significantly more confident (p < 0.001). Private clinic professionals were also more likely to offer personalized nutritional guidance (36.4%) compared to those in government (3.8%) and teaching institutions (30.3%; (p < 0.001). Common barriers identified included insufficient training (65%, p = 0.024) and time constraints (45%, p = 0.062). Moreover, the perceived impact of nutritional counseling on oral health management was significant, with 70% of participants agreeing that it enhances overall patient outcomes.

Conclusion The findings suggest that while dental practitioners recognize the value of PNC, significant barriers impede its consistent application. Addressing these barriers through enhanced training and resources is essential for integrating nutritional counseling into routine oral health care practices, ultimately benefiting patient outcomes. There is a strong call for improved training and resources to equip dental practitioners to provide personalized nutritional advice.
The pricing of sustainability-linked bonds on the primary and secondary bond markets
Authors: Poggensee Jannis
Published: February 2025

This paper investigates the yield differentials between sustainability-linked bonds (SLBs)—a novel fixed income instrument whose coupon payments are linked to the achievement of predefined sustainable performance targets—and conventional bonds issued by the same company, both on the primary and secondary bond markets. By fitting yield curves with the Nelson–Siegel Svensson method on the SLB’s pricing day and applying panel regressions to examine yield differentials thereafter, the study assesses whether SLBs trade at a premium, indicating higher prices and consequently lower yields. Fixed-effects panel regression is utilized to isolate the unobserved time-invariant yield differential between SLBs and a matched synthetic conventional bond with the same residual maturity. The results show a statistically significant but economically small premium for SLBs in both the primary and secondary market. The sustainability premium is not significantly driven by the SLB’s penalty structure and fluctuates over time. This research contributes to the literature by applying a novel methodological framework to examine the evolving nature of SLB premiums and their implications for both issuers and investors.
Reinforcement learning versus data-driven dynamic programming: a comparison for finite horizon dynamic pricing markets
Authors: Lange Fabian , Dreessen Leonard , Schlosser Rainer
Published: February 2025

Revenue management (RM) plays a vital role to optimize sales processes in real-life applications under incomplete information. The prediction of consumer demand and the anticipation of price reactions of competitors became key factors in RM to be able to apply classical dynamic programming (DP) methods for expected long-term reward maximization. Modern model-free deep Reinforcement Learning (RL) approaches are able to derive optimized policies without explicit estimations of underlying model dynamics. However, RL algorithms typically require either vast amounts of training data or a suitable synthetic model to be trained on. As existing studies focus on one group of algorithms only, the relation between established DP approaches and new RL techniques is opaque. To address this issue, in this paper, we use a dynamic pricing framework for an airline ticket market to compare state-of-the-art RL algorithms and data-driven versions of classic DP methods regarding (i) performance and (ii) required data to each other. For the DP techniques, we use estimations of market dynamics to be able to compare their performance and data consumption against RL methods. The numerical results of our experiments, which include monopoly as well as duopoly markets, allow to study how the different approaches’ performances relate to each other in exemplary settings. In both setups, we find that with few data (about 10 episodes) fitted DP methods were highly competitive; with medium amounts of data (about 100 episodes) DP methods got outperformed by RL, where PPO provided the best results. Given large amounts of training data (about 1000 episodes), the best RL algorithms, i.e., TD3, DDPG, PPO, and SAC, performed similarly achieving about 90% and more of the optimal solution.
First- and second-order phase transitions in Heisenberg’s quantum model with multispin exchange
Authors: Murtazaev A. K. , Favorskii I. A.
Published: February 2025

First- and second-order phase transitions in the isotropic Heisenberg model with multispin exchange were investigated with the help of the quantum Monte Carlo method. The calculations were performed for a system with spin S = 1/2 and N = L3 spins (L = 8, 12, and 16) on simple cubic lattices with periodic boundary conditions. A relation between the pair and multispin exchange constants for which the second- order phase transitions are replaced by first-order phase transitions is established. First-order phase transitions have not been studied previously by the quantum Monte Carlo method. Phase diagrams were constructed for the model under study. The computational results are compared with the method of Green’s functions and the molecular-field theory.
Investigation of the kinetic and structural characteristics of zirconium-doped Y–Ba–Cu–O ceramic
Authors: Anders É. E. , Batrak A. G. , Nechiporenko I. N. , Prokhvatilov A. I. , Startsev S. V. , Tikhenko É. V. , Yantsevich L. D.
Published: February 2025

Hysteresis phenomena were observed in the thermal conductivity of zirconium-doped 1-2-3 yttrium ceramic. Doping with zirconium increases the hysteresis phenomena in the thermal conductivity of 1-2-3 ceramic in the region of the superconducting transition. The characteristic features of the temperature dependence κ(T) are compared with the anomalies in the temperature dependences of the electric resistance and the lattice parameters in the region of the superconducting transition (90−120 K).
Spectrum of excitations of the superconducting SN superlattice in the current-carrying state
Authors: Kuplevakhskii S. V. , Fal’ko I. I.
Published: February 2025

The model system of Bogolyubov–de Gennes equations, which describes a superlattice formed by alternating layers of superconducting S and normal N metals, in the current-carrying state in the energy range E <Δ0 (Δ0 is the energy gap) is solved. It is shown that the spectrum is of a band character and depends on the coherent phase difference φ between the neighboring superconducting layers.
Low-temperature magnetoelastic properties of dilute Jahn–Teller DyxY1–xVO4 crystals
Authors: Vasil’ev A. V. , Kaplan M. D. , Kazeĭ Z. A. , Sokolov V. I.
Published: February 2025

The magnetic and magnetoelastic properties of dilute Jahn–Teller DyxY1–xVO4 single crystals and polycrystals are studied experimentally and theoretically. Particular attention is paid to the anomalies caused in the properties by random strains. The effect of random strains of various symmetries on the critical temperature of the structural phase transitions is considered.
Resonance properties of the four-sublattice antiferromagnet CuCI2·2H2O
Authors: Eremenko V. V. , Zvyagin S. A. , Pishko V. V. , Pashkevich Yu. G. , Shakhov V. V.
Published: February 2025

Antiferromagnetic resonance in CuCl22H2O is studied at various orientations of the external magnetic field and an original method is described for studying the resonance properties of multisublattice magnetic materials in the wavelength range 0.2–10 mm. The experimental results are compared with our previous dynamic susceptibility calculations for various phases of magnetic ordering. A number of distinctive features of interaction between exchange and acoustic modes in the antiferromagnet copper chloride dihydrate are discussed.
Helicon–phonon resonance in a superlattice
Authors: Bebenin N. G.
Published: February 2025

The propagation of electromagnetic and elastic waves in a periodic structure in a constant magnetic field is studied. It is assumed that a helicon–phonon resonance occurs in one of the layers of the superlattice–the metallic layer–while in the other layer the waves are independent. It is shown that if the elastic impedances of the media differ strongly from one another, then near the resonance point the wave vector of the elastic wave travelling in the superlattice depends strongly on the magnetic field; the effect of the resonance on the electromagnetic wave is weaker.
Spectral properties of weakly ferromagnetic dielectric crystals CoCO3 in a nearly saturated paramagnetic state
Authors: Shapiro V. V. , Kachur I. S. , Eremenko A. V. , Piryatinskaya V. G.
Published: February 2025

The absorption spectrum of the weakly ferromagnetic two-sublattice cobalt carbonate in strong magnetic fields is studied over a wide spectral region. It is shown that the CoCO3 spectrum consists of absorption bands with sharply different intensities, which correspond to spin-allowed as well as spin-forbidden transitions. The intensity of spin-allowed bands is practically insensitive to the spin-wave subsystem and, in contrast to spin-forbidden optical transitions, depends weakly on the magnetic structure. The fine structure of the optical absorption spectrum of CoCO3 is analyzed in detail in the vicinity of the pure excitation line, and a correlation between structure components and spin-wave dispersion is established.
Temperature dependence of the pyroelectric coefficient γ
σ (T) of lithium sulphate monohydrate in the temperature range 1.5–350 K
Authors: Esengaliev A. B. , Novik V. K. , Novikov V. N. , Gavrilova N. D.
Published: February 2025

It is shown that the temperature dependence of the pyroelectric effect of an LSM (lithium sulfate monohydrate) single crystal in the polar direction Y is described in the temperature range 1.5–300 K by the relation γyσ(T)=c0DΘD/T+∑i=13ciEΘEi/T where D and E are the Debye and Einstein functions. Consequently, the temperature variation of the spontaneous polarization PSy(T) is caused by the anharmonism of both acoustic and optical vibrations. It is found that spontaneous polarization components exist along the nonpolar directions X and Z. These components are formed below 110 K and have a much smaller magnitude than | PSy | : |PSx | | PSy |−1, | PSz | | PSy |−1 ≤ 10−4. The LSM symmetry is reduced to its lowest level 1, which leads to the assumption of the possibility of a “polar phase–polar phase” transition associated with the change of state of water molecules in the temperature region ∼100 K. Investigations of the effect of various doses of γ-radiation on the γyσ(T),γxσ(T),γzσ(T) dependences reveal a high stability of LSM single crystals to radiation
Experimental investigation of magnetic resonance in Nd2CuO4
Authors: Eremenko V. V. , Zvyagin S. A. , Pishko V. V. , Barilo S. N. , Zhigunov D. I.
Published: February 2025

The frequency–field dependences of absorption lines which correspond to acoustic modes of antiferromagnetic resonance of copper ions and to excitations of rare-earth ions in a disordered state, are investigated experimentally in high-quality Nd2CuO4 single crystals in an external magnetic field for various orientations.
Experimental overview of point-contact spectroscopy in metals
Authors: Jansen A. G. M. , Wyder P.
Published: February 2025

The smallness of metallic contacts (the contact size is smaller than the electron mean free path) permits spectroscopic studies to be made with respect to the well-defined excess energy eV of electrons by tuning the applied voltage V. Examples of point-contact spectroscopy will be given for the study of energy-dependent scattering of the electrons by quasiparticle excitations within a metal (phonons, magnons, paramagnetic impurities crystal field levels). The limitations of the point-contact technique will be discussed. The ballistic transport enables studies of other phenomena under the voltage-defined non-equilibrium state of the electrons, e.g., high-frequency rectification, thermal transport, weak localization, magnetic quantum oscillations, and noise.
Point-contact spectroscopy study of oscillatory spectrum of the organic conductor β-(BEDT-TTF)2l3
Authors: Kamarchuk G. V. , Pokhodnya K. I. , Khotkevich A. V.
Published: February 2025

Point homo- and heterocontacts (with copper and silver) of the organic conductor β-(BEDT-TTF)2I3 have been investigated. The current-voltage characteristics of the point contacts and their second order derivatives (point-contact spectra) in the voltage region of 0–250 mV have been measured. Features reflecting the oscillatory spectrum structure of the organic metal have been discovered. It is noted observation of nonlinearities at high voltages suggest an essential contribution of charge carriers interaction with intramolecular oscillations to the point-contact spectrum.
Reproducible fabrication of point contacts 10–100 nm in diameter and their electrical properties
Authors: Kasumov A. Y. , Kislov N. A. , Kononenko O. V. , Matveev V. N.
Published: February 2025

Point contacts were made using a transmission scanning electron microscope. A layer of metal about 100 nm thick was deposited onto a silicon membrane (SiO2 film on a Si substrate). Then two tracks 2 μm thick were etched in the metal and SiO2. The tracks were made in the shape of a cross so that they could divide the membrane into four electrically isolated parts. The membrane (SiO2 film) was cut through. In the space between the membrane edges the desirable microstructure was provided by electron beam scanning over the membrane surface and in the space beyond. The interaction between the electron beam and the hydrocarbon molecules adsorbed at the surface produced a hydrocarbon filament 10–100 nm in diameter (which depends on the scanning condition). The thread continued to grow beyond the membrane towards the beam scanning, which seems to be due to the surface diffusion of the hydrocarbon atoms stimulated by the electron irradiation.

One of the ways of making point contacts was as follows. Two hydrocarbon threads were being grown approaching each other from the opposite edges of the cut membrane until the clearing between the thread ends was about 10 nm. Then a layer 1–10 nm thick of metal or superconductor (ordinary or HTS) was evaporated onto the threads until the clearing gradually disappeared and a direct contact was formed. In parallel, the electric properties of the point contacts were studied in the process of transition from the tunnel contact to that with direct conductivity.
Temperature dependence of point-contact spectra for Ag:Nd1.85Ce0.15CuO4–δ heterocontacts
Authors: Smith C. W. , Reinertson R. C. , Dolan P. J.
Published: February 2025

Measurements of differential resistance as a function of voltage bias for Ag:Nd1.85Ce0.15CuO4–δ point contacts were made. A peak in the differential resistance centered around zero bias is observed below the superconducting critical temperature of Nd1.85Ce0.15CuO4–δ. Good agreement to theory for the temperature dependence of the zero-bias resistance is obtained.
Manifestation of the proximity effect in break junctions based on Bi–Sr–Ca–Cu–O:Pb
Authors: Aminov B. A. , Bush A. A. , Oskina T. E. , Ponomarev Ya. G. , Sethupathi K.
Published: February 2025

Tunneling effects in poly- and monocrystalline samples of BiSrCaCuO:Pb compounds (2212 and 2223 phases) have been investigated. A reproducible vertical rise of current of I(V) characteristics of break junctions at gap voltages has been found. A clearly defined “knee” structure has been observed at voltages V≈2Δ/e. The temperature dependences of 2Δ had behavior typical for bilayer supercondcutors with different critical temperatures, where the proximity effect plays an essential role.
Tunneling observation of phonon structures in superconducting La1.85Sr0.15CuO4
Authors: Ekino Toshikazu
Published: February 2025

Through the tunneling measurements on the superconducting La1.85Sr0.15CuO4 it has been found that the maxima and minima in the second derivative curve below 60 meV measured from the gap edge at 7 meV correspond to the generalized neutron phonon density of states reported by Renker et al. This fact suggests that phonons are presumably playing a role in paring interaction in this superconductor.
Point-contact spectroscopy of high-Tc superconductors
Authors: Yanson I. K.
Published: February 2025

The physical grounds of the direct conductivity pointcontact spectroscopy of high-Tc superconductors are described. The results of the energy gap measurements and the structure of derivatives of the I–V curves at overgap energies for LaSrCuO, YBaCuO, and BiSrCaCuO materials are reviewed. The temperature-dependent gap-like structure on the derivatives of I–V characteristics in the normal state was found, and a new phenomena of reversible destruction and restoration of superconductivity in the contact region by high voltage bias and relatively low magnetic field were observed.
On the energy distribution of gaps in GdBa2Cu3O7
Authors: Akimenko A. I. , Goll G. , van Löhneysen H. , Gudimenko V. A.
Published: February 2025

GdBa2Cu3O7 (polycrystalline) point-contact (PC) spectra exhibit a reproducible, gap-like structure that looks like a wide minimum between ≈ ±10 and ±35–40 meV. The PC spectra of single-phase (Tc = 91 K) polycrystalline YBa2Cu3O7, whose gap singularities occur at different energies (between 7 and 29 meV) and have different shapes (narrow and broad minima relative to the voltage), are analyzed here also. These variations can be the explained by taking into account the gap anisotropy and the different PC configurations ("orifice" or "channel"). As a result a histogram of the energy distribution of the gaps in YBa2Cu3O7 was obtained. Using the similar energy distribution in the BTK calculation, we find a good agreement between the calculated and experimental GdBa2 ⋅ Cu3O7 PC spectra.
Gap anisotropy and gapless superconductivity in the Zn-doped YBa2Cu3O7
Authors: Akimenko A. I. , Goll G. , van Löhneysen H. , Gudimenko V. A.
Published: February 2025

Point-contact (PC) spectra of polycrystalline YBa2 ⋅ (Cu1−xZnx)3O7 with x = 0.05 and 0.075 have been studied at various temperatures (counter-electrode is Ag). Two kinds of PC spectra have been found for PC spectra have been found for PC's with the same Tc (value of Tc has been determined by analyzing the temperature dependence of PC resistance at V ≈ 0). Apart from the well-known PC spectra with a gap minimum (or kink), which shifts to V = 0 with increasing temperature, we have found some spectra without gap minimum. Only a rather smooth dV/dI increase can be found at the bias voltages where the possible gap is expected. The voltage position of such a dV/dI enhancement does not change essentially with increasing temperature at T < Tc. Recently, almost the same results were obtained by theorists for the N–c–S point contact in the gapless superconductivity case. The data are interpreted in terms of a gap anisotropy with a vanishing gap, parallel to the c direction.
Investigation of electron–phonon interaction in Tc1–xMox–Ag(S–N) point contacts
Authors: Zakharov A. A. , Tsetlin M. B.
Published: February 2025

The first derivatives of the IVC of the TC1–xMox–Ag point contacts in superconducting state have been investigated. In the energy range 8–16 meV there are minima similar in shape and amplitude to those observed earlier in the Tc–Ag point contacts, which are connected with the manifestation of the EPI as it was shown. The amplitude of EPI peculiarities remains essentially unchanged when the Mo concentration increases and amounts to several percent for all investigated contacts. It is seen that as the Mo concentration grows, the observed peculiarities are shifted to the low-energy area. The displacement of the EPI peaks with increasing x correlates with the growth of the critical temperature in these alloys. As the Mo concentration increases from 0 to 20%, Tc increases 1.5 times and ω0 (the minimum position) decreases 1.7 times. Excess current in such contacts is evaluated for different x and the possible mechanisms of manifestation of the EPI on the IVC of the S-N contacts are considered.
I–V characteristics of S–c–N contacts based on the amorphous superconductor Zr2Ni
Authors: Naidyuk Yu. G. , Kvitnitskaya O. E.
Published: February 2025

The I–V characteristics (IVC) are measured on S–c–N contacts whose resistance varies from the tenths to several tens of ohms between Zr2Ni and the normal metal (Cu, Ag), as the temperature goes below Tc ≃ 2.5 K. The IVC nonlinearity is observed to increase significantly both upon decreasing temperature and upon a reduction of the contact resistance. In the latter case at a certain critical value of the current the IVC acquires a singularity of the voltage jump type. The singularity observed is accounted for by the processes of the Abrikosov vortex creation as the current becomes critical and the contact region transforms into the resistive state. The qualitative difference between the IVC of low-resistivity point contacts and high-resistivity ones is related to the effect of the contact size upon the vortices kinetics. The correlation is found for the values of the critical parameters of the superconductor and the positions of the specific points in the IVC of contacts studied.
Localized states induced by supercurrent in point contacts
Authors: Kuplevakhsky S. V. , Fal’ko I. I.
Published: February 2025

We show that the suppression of the Cooper pairing by supercurrent in point contacts leads to the formation of an Andreev-type localized state. The energy of this state, which is less than the gap in the bulk, is determined from the Bogolyubov–de Gennes equations. We also consider supercurrent-induced localized states in an infinite chain of point contacts and discuss some experimental implications.
High-frequency response of metal point contacts with small electron mean free paths
Authors: Balkashin O. P. , Kulik I. I. , Moslakets M. V.
Published: February 2025

The influence of external electromagnetic field on metal point contacts (copper–copper, nickel–nickel) with a small electron mean free path (heating regime) has been investigated. The frequency was changed from the sound to optical range. In terms of the microscopic theory the generated response signal as a function of the bias voltage has been calculated. The result is in good agreement with experimental data for the sound and microwave frequencies. But in the 4.3·1012–28·1012 Hz frequency range the bias-response dependence was observed to change. This effect is explained by heating of the sides due to irradiation. Calculation results agree well with experiment. The response nature in the same frequency range was observed also in ballistic contacts.
Triangular magnetic structures in an external magnetic field
Authors: Vitebskii I. M. , Loktev V. M. , Chabanov A. A.
Published: February 2025

The behavior of triangular antiferromagnetic structures is studied in an external magnetic field. It is shown that, in the exchange approximation, the spin orientation in the hexagonal plane and the activation part of the magnon spectral branches are described by a weak biquadratic exchange interaction. Equilibrium spin configurations and expressions for AFMR frequencies are obtained for the case of an easy-plane structure in a transverse field.
Probability distribution for a Langevin paramagnet
Authors: Sadaoui You. , Tsukernik V. M.
Published: February 2025

The probability distribution function for the transverse spin component (perpendicular to the constant external magnetic field) is constructed for a Langevin paramagnetic gas in thermodynamic equilibrium. It is shown that the quantum nature of spin affects the temperature-field probability dependence. The obtained asymptotic forms show that the probability distributions for classical spin and quantum spin of large magnitude are quite different. A characteristic function is obtained for determining the mean values of higher-order spin multipoles.
Low-temperature phase transitions in layered InI crystals
Authors: Kolin’ko N. I. , Kityk I. V. , Krochuk A. S.
Published: February 2025

X-ray diffraction studies point towards the existence of a structurally incommensurate phase in layered InI single crystals in the temperature interval 20–22.5 K. Piezo-optical and dilatometric techniques reveal that the transition is ferroelastic with a temperature hysteresis of about 5 K. Neutron irradiation leads to a decrease in spontaneous deformation.
Quantum-inertial mechanism of plastic deformation of lead-based alloys at temperatures around and below 1 K
Authors: Isaev N. V. , Natsik V. D. , Pustovalov V. V. , Shepel’ I. A. , Shumilin S. É.
Published: February 2025

The temperature dependences of the yield stress and sensitivity of the deforming stress to the deformation rate of Pb–Sn and Pb–Sb single crystals are studied in the temperature range 0.5–80 K. The parameters of the thermally activated motion of dislocations through impurity centers are determined. The low-temperature plasticity anomalies observed below 30 K are attributed to the inertial mechanism, while the anomaly observed at T < 10 K can be described satisfactorily by the quantum-inertial mechanism of dislocation movement through local barriers. A method is proposed for a quantitative estimation of the contribution from inertial and quantum properties of dislocations to the observed concentration and temperature dependences of the plasticity parameters.