bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparing the predictive validity of four MCI definitions for incident dementia in demographically diverse community-dwelling individuals: Results from the Einstein Aging Study (EAS)
Authors: Chang Katherine H. , Wang Cuiling , Qin Jiyue , Katz Mindy J. , Byrd Desiree A. , Lipton Richard B. , Rabin Laura A.
Published: December 2024

Objective:

Research examining (MCI) criteria in diverse and/or health-disparate populations is limited. There is a critical need to investigate the predictive validity for incident dementia of widely used MCI definitions in diverse populations.

Method:

Eligible participants were non-Hispanic White or Black Bronx community residents, free of dementia at enrollment, with at least one annual follow-up visit after baseline. Participants completed annual neurological and neuropsychological evaluations to determine cognitive status. Dementia was defined based on DSM-IV criteria using case conferences. Cox proportional hazard models assessed predictive validity for incident dementia of four specific MCI definitions (Petersen, Jak/Bondi, number of impaired tests, Global Clinical Ratings) at baseline, controlling for age, sex, education, and race/ethnicity. Time-dependent sensitivity and specificity at 2–7 years for each definition, and Youden’s index were calculated as accuracy measures.

Results:

Participants (N = 1073) ranged in age from 70 to 100 (mean = 78.4 ± 5.3) years at baseline. The sample was 62.5% female, and educational achievement averaged 13.9 ± 3.5 years. Most participants identified as White (70.0%), though Black participants were well-represented (30.0%). In general, MCI definitions differed in sensitivity and specificity for incident dementia. However, there were no significant differences in Youden’s index for any definition, across all years of follow-up.

Conclusions:

This work provides an important step toward improving the generalizability of the MCI diagnosis to underrepresented/health-disparate populations. While our findings suggest the studied MCI classifications are comparable, researchers and clinicians may choose to consider one method over another depending on the rationale for evaluation or question of interest.
Association between chest-to-head circumference ratio at birth and childhood neurodevelopment: the Japan Environment and Children’s Study
Authors: J-P Naw Awn , Eitoku Masamitsu , Yamasaki Keiko , Mitsuda Naomi , Fujieda Mikiya , Maeda Nagamasa , Suganuma Narufumi ,   the Japan Environment and Children’s Study (JECS) Group
Published: December 2024

Children born growth-restricted are well recognized to be at an increased risk of poor neurodevelopmental outcomes. This prospective study examined the influence of chest-to-head circumference ratio at birth on neurodevelopment in the first three years among children enrolled in the Japan Environment and Children’s Study. We analyzed information of 84,311 children (43,217 boys, 41,094 girls). Children were divided into low, normal, and high chest-to-head circumference ratio groups. Neurodevelopment was assessed every six months (from 6 months to 3 years) using the Ages and Stages Questionnaire (Japanese translation), with delays defined as scores below 2 standard deviations from the mean. Additionally, we evaluated the contributions of chest and head circumference to the observed association. Linear mixed-effect regression revealed increased risk of delays in communication, gross motor, fine motor, problem-solving, and personal-social skills in the low-ratio group compared to the normal-ratio group. Adjusted risk ratios were in the range of 1.14 – 1.39 in boys and 1.16 – 1.37 in girls, with no such increase observed in the high-ratio group. The heightened risk in the low-ratio group was likely associated with a relatively narrow chest rather than a large head. The area under the ROC curves in predicting any developmental delay at three years for newborn measurements ranged from 0.513 to 0.526 in boys and 0.509 to 0.531 in girls. These findings suggest that a low chest-to-head circumference ratio may indicate children who are at risk for neurodevelopmental deficits. However, the ability to predict poor neurodevelopmental outcomes at three years of age is limited.
Quantitative Evaluation of Probabilistic Hazard Mapping With Polynomial Chaos Quadrature and Its Practical Application
Authors: Tanabe T. , Tsunematsu K. , Nishimura K.
Published: December 2024

Snow avalanches pose a significant threat to settlements and their inhabitants. Consequently, hazard maps that delineate avalanche runout areas serve as valuable tools for mitigating their destructive impact. Dynamic models have been used to visualize areas affected by avalanches; however, these models require uncertain inputs. This study develops probabilistic hazard maps by quantifying uncertain input variables through probability density functions. These maps represent the probability of model outputs, such as maximum flow thickness, exceeding specific thresholds, allowing for more quantitative hazard assessments. Three uncertainty quantification methods—Monte Carlo, Latin hypercube sampling, and polynomial chaos quadrature (PCQ)—are employed to generate probabilistic hazard maps for snow avalanches. These maps are compared with a reference hazard map created using parameter sets that cover the entire parameter space. Among the three methods, PCQ yields the most accurate results for a given number of simulations, assuming a uniform distribution for each input. The optimal PCQ settings, which deliver superior results with fewer simulations, are then determined. Additionally, a PCQ application is proposed to generate hazard maps based on non‐uniform input distributions without requiring extra simulations. This approach reduces the computational cost associated with creating hazard maps for non‐uniform distributions if PCQ has already been applied to a uniform case. The application generates two types of probabilistic hazard maps: one considering all potential parameter ranges during the snow season using uniform distributions, and another reflecting non‐uniform distributions that account for uncertainty in near‐term current snow cover conditions.
Investigating Mechanisms Driving Differences in the Characteristics of Precipitation in the E3SM Multiscale Modeling Framework With 2D Versus 3D Cloud Resolving Model Configurations
Authors: Hsu Wei‐Ching , Kooperman Gabriel J. , Hannah Walter M.
Published: December 2024

In this study, we compare the Energy Exascale Earth Systems Model (E3SM) multiscale modeling framework (MMF) with the cloud resolving model (CRM) configured in two (2dMMF) and three (3dMMF) dimensions. We explore how CRM dimensionality impacts the representation of mean and extreme precipitation characteristics. Our results show that tropical mean precipitation patterns are better represented in 3dMMF compared to observations (Integrated Multi‐satellitE Retrivals for GPM and Global Precipitation Climatology Project One Degree Daily products), while 2dMMF better captures extreme precipitation intensity, with systematic land‐ocean differences in precipitation and cloud‐associated variables. These differences are attributed to the co‐occurrence of CRM throttling (i.e., suppressed convection in due to smaller numbers of CRM columns and domain size) and dilution (i.e., 3‐D cloud circulations with increased entrainment and lower precipitation efficiency) effects. Overall, throttling results in more low‐level humidity in 2dMMF and dilution contributes to more high clouds with less precipitation efficiency in 3dMMF. Since throttling occurs more strongly over the ocean than land, the 3dMMF tends to have less cloud liquid and precipitation over the ocean and more cloud ice and precipitation over land. These results may serve as a guide for choosing the CRM structure to reduce precipitation and cloud‐related biases.
Paleolatitudinal Drift and Major Rotation of the Wrangellia Superterrane in the Mesozoic: A Signal of East‐Panthalassa Plate Motion?
Authors: Andjić Goran , Vaes Bram , van de Lagemaat Suzanna H. A. , Boschman Lydian M. , Dekkers Mark J. , Johnston Stephen T. , van Hinsbergen Douwe J. J.
Published: December 2024

The allochthonous origin of the Wrangellia superterrane relative to North America (NAM) has been established in the early days of plate tectonics using paleomagnetic and geologic data. However, orogenic deformation of the Wrangellia superterrane after its Cretaceous accretion to NAM has complicated the reconstruction of its pre‐accretionary tectonic evolution. In particular, vertical‐axis rotations linked to strike‐slip faulting have cast doubt on the usefulness of paleomagnetic declinations in deciphering its pre‐accretionary motions. Here, we compile paleomagnetic data from the Wrangellia superterrane and present new results from uppermost Triassic limestones and lowermost Jurassic lavas of the Bonanza arc, which confirm that it was at those times at a much lower latitude than today (∼50°–60°N), at a latitude of either ∼25°–30°N or ∼25°–30°S. Moreover, declinations reveal a coherent, major clockwise or counterclockwise rotation, depending on hemispheric origin. When correcting for previously documented true polar wander at the approximate longitude of the Wrangellia superterrane at ∼190 Ma, new and existing paleomagnetic data allow for two possible scenarios of Mesozoic kinematic evolution: from 190 to 80 Ma, in the southern hemisphere scenario, the Wrangellia superterrane was transported ∼5,000 km northward while rotating ∼110° clockwise with an associated north‐dipping subduction zone, while in the northern hemisphere scenario it remained at northern middle latitudes while rotating ∼70° counterclockwise at a south‐dipping subduction zone. The southern hemisphere scenario appears more plausible when tested against recent reconstructions of minimum oblique convergence beneath NAM and mantle tomography images of slab remnants.
Oxidative Dissolution of Sulfide Minerals in Porous Media Under Evaporative Conditions: Multiphase Experiments and Process‐Based Modeling
Authors: Ahmadi Navid , Muniruzzaman Muhammad , Cogorno Jacopo , Rolle Massimo
Published: December 2024

The dissolution of sulfide minerals in subsurface porous media has important environmental implications. We investigate the oxidative dissolution of pyrite under evaporative conditions and advance a mechanistic understanding of the interactions between multiple physical processes and mineral/surface reactions. We performed a set of experiments in which initially water saturated and anoxic soil columns, containing a top layer of pyrite, are exposed to the atmosphere under no evaporation (single‐phase) and natural evaporative (two‐phase) conditions. The oxidative dissolution of pyrite was monitored by non‐invasive high‐resolution measurements of oxygen and pH. Additionally, we developed and applied a multiphase and multicomponent reactive transport model to quantitatively describe the experimental outcomes and elucidate the interplay between the physico‐chemical mechanisms controlling the extent of pyrite dissolution. The results confirm that the extent of pyrite dissolution under single‐phase conditions was constrained by the slow diffusive transport of oxygen in the liquid phase. In contrast, during evaporation, the evolution of fluid phases and interphase mass transfer processes imposed distinct physical constraints on the dynamics of pyrite oxidation. Initially, the invasion of the gaseous phase led to a fast delivery of high oxygen concentrations in the reactive zone and thus markedly increased pyrite oxidation and acidity/sulfate production. However, such enhanced release of reaction products was progressively limited over time as drying conditions prevailed in the reactive zone and inhibited pyrite oxidation. The transient phase displacement was also found to control the distribution of aqueous species and formation of secondary minerals by creating spatio‐temporally variable redox conditions.
Nonlinear coupling of closely spaced modes in atomically thin MoS2 nanoelectromechanical resonators
Authors: Yousuf S M Enamul Hoque , Shaw Steven W. , Feng Philip X.-L.
Published: December 2024

Nanoelectromechanical systems (NEMS) incorporating atomic or molecular layer van der Waals materials can support multimode resonances and exotic nonlinear dynamics. Here we investigate nonlinear coupling of closely spaced modes in a bilayer (2L) molybdenum disulfide (MoS2) nanoelectromechanical resonator. We model the response from a drumhead resonator using equations of two resonant modes with a dispersive coupling term to describe the vibration induced frequency shifts that result from the induced change in tension. We employ method of averaging to solve the equations of coupled modes and extract an expression for the nonlinear coupling coefficient (λ) in closed form. Undriven thermomechanical noise spectral measurements are used to calibrate the vibration amplitude of mode 2 (a2) in the displacement domain. We drive mode 2 near its natural frequency and measure the shifted resonance frequency of mode 1 (f1s) resulting from the dispersive coupling. Our model yields λ = 0.027 ± 0.005 pm−2 · μs−2 from thermomechanical noise measurement of mode 1. Our model also captures an anomalous frequency shift of the undriven mode 1 due to nonlinear coupling to the driven mode 2 mediated by large dynamic tension. This study provides a direct means to quantifying λ by measuring the thermomechanical noise in NEMS and will be valuable for understanding nonlinear mode coupling in emerging resonant systems.
Vascular Ehlers-Danlos syndrome in children: evaluating the importance of diagnosis and follow-up during childhood
Authors: Wilkinson Niamh R. , Cervi Elena , Wagner Bart , Morris-Rosendahl Deborah , Baker Duncan , Flora Harpaul , von Klemperer Kate , Andrew Toby , Ghali Neeti , van Dijk Fleur S.
Published: December 2024

Vascular Ehlers-Danlos syndrome (vEDS) is a rare inherited connective tissue disorder predominantly caused by pathogenic COL3A1 variants. Characteristic arterial and intestinal fragility and generalised severe tissue friability can lead to clinical events from childhood. We highlight a paucity of literature regarding children diagnosed with vEDS, possibly explained by a restraint in predictive testing, and present data on 63 individuals (23 index cases) with a clinical and genetic diagnosis of vEDS in childhood (<18 years) to address this. Patients were identified through the National Ehlers-Danlos Syndrome (EDS) Service London. We report on 18 events in childhood, recorded in 13 individuals. First events occurred at a median age of 11 years (IQR 0–13) and genetic testing was initiated as a direct result of the first event in 11/13 cases. In the cohort majority, diagnosis was the result of familial genetic testing (55%). Our findings emphasise the importance of offering genetic testing in childhood when there is a positive family history of vEDS and/or features suggestive of a potential inherited connective tissue disorder. Diagnosis in childhood allows for follow-up surveillance and informed multi-disciplinary management, in addition to genetic counselling and patient-led management including lifestyle modification. As seen in adult cohorts, we anticipate children with vEDS will experience the same protective benefit afforded by early diagnosis and present preliminary data on follow-up in childhood. Formal evaluation of the impact that diagnosis of vEDS in childhood has on disease management is needed when sufficient data is internationally available.
An image and video dataset of nesting green sea turtles with annotated data
Authors: Hipiny Irwandi , Ujir Hamimah , Hassan Ruhana , Abang Aimran Abang Arabi
Published: December 2024

Photo- and video-based reidentification of green sea turtles using their natural markers is far less invasive than artificial tagging. An RGB camera mounted on a man-portable rig, was used to collect video data on Greater Talang Island (1 °54’45″N 109 °46’33″E) from September to October 2022, and September 2023. This islet is located 30 minutes offshore from the Sematan district in Southwest Sarawak, Malaysia. In total, 42 videos of 42 unique individuals were captured, from which 14,471 video frames were extracted and annotated with a bounding box each. Through manual inspection, the annotation data were diligently checked and edited if necessary. Additionally, 130 selected frames were further annotated each with a region-of-interest mask containing only the carapace. These data have the potential to aid researchers in training computer vision models for various tasks such as counting, segmentation and individual reidentification.
Global big data laboratory experiment, integrated with kernel-based algorithm with an improved nonlinear ensemble for compressive strength modeling
Authors: Salami Babatunde Abiodun , Usman Jamilu , Gbadamosi Afeez , Malami Salim Idris , Abba Sani I.
Published: December 2024

With the continuous clamor for a reduction in embodied carbon in cement, rapid solution to climate change, and reduction to resource depletion, studies into substitute binders become crucial. These cementitious binders can potentially lessen our reliance on cement as the only concrete binder while also improving concrete functional properties. Finer particles used in cement microstructure densify the pore structure of concrete and enhance its performance properties. The compressive strength of concrete made from a mixture of ground granulated blast furnace slag (GGBFS), fly ash (FA), and ordinary Portland cement was estimated using kernel regression techniques in this work. The kernel-based method offered was support vector regression (SVR), while robust linear regression (RLR), and multi-linear regression (MLR) were used as regression methods, subsequently, nonlinear average approaches were used to improve the accuracy of the prediction. Eight variables (cement, FA, GGBFS, water, superplasticizer dose [SP], coarse aggregate [CA], fine aggregate [Fag], age) were employed as input features in 3323 data samples, and their relative value was assessed using linear correlation analysis. Following analysis, three combinations were employed to train the kernel-based models: I (inputs: cement, water, and age|output: CS), II (inputs: cement, water, FA, SP, and age|output: CS), and III (inputs: cement, water, FA, SP, CA, GGBFS, and Fag|output: CS). The third combination gave the best testing performance with all the proposed models where their R2 and MSE results after model evaluation for SVR, RLR, and MLR, are [0.984, 0.8776 and 0.8804] and [0.0019, 0.0131 and 0.0128] respectively. The study concludes that SVR with the combination III (SVR-M3) offered the best performance through effectiveness and efficiency in accurately predicting the compressive strength of the blended concrete. The prediction models should be utilized with the input variable ranges used in this work.
Evaluating the effectiveness of oral HIV self testing according to distribution models in Cameroon
Authors: Bouba Yagai , Djomo Audrey Raissa Dzaddi , Mouliom Fatima Nkain , Souleymanou Adamou , Lifanda Ebiama , Liman Yakouba , Onana Roger , Salla Annie Michele , Ekobika Lily Claire , Tchikangni Gutenberg , Omona Edwige Guissana , Myrtho Ingrid Kenko Abo’o , Mvilongo Ernest Désiré Anaba , Socpa Antoine , Ajeh Rogers Awoh , Essi Marie Jose , Billong Serge Clotaire , Hamsatou Hadja Cherif , Bissek Anne Cecile Zoung-Kanyi
Published: December 2024

Innovative strategies such as HIV self-testing (HIVST) are useful for identifying hard-to-reach people living with HIV/AIDS (PLHIV), especially in developing settings where considerable gaps still exist in reaching the first 95% UNAIDS target. We evaluated the effectiveness of HIVST in Cameroon using several distribution models and investigated the predictors of HIV seropositivity among self-testers. The study was conducted from 2021 to 2022 in three regions in Cameroon. HIVST kits were distributed according to 5 distribution models: antenatal, postnatal, maternal and child clinics (ANC/PNC/MCH); partners of PLHIV; workplace; community and HIV-testing services (HTS). Overall, 42,687 people received oral HIVST kits, among whom 15.6% were HIV first-testers. Approximately 85% reported on the test outcome; 2.3% (n = 825) were reactive, and 75.8% came for test confirmation. After the confirmation test, a concordance of 85% was found with the national algorithm. Overall, the HIV seroprevalence was 1.5% [95% CI: 1.4–1.6]; ANC/PNC/MCHC: 1.9%, partners of PLHIV: 6.9%, workplace: 0.5%, community: 0.1% and HTS: 7.0%, p < 0.001. The positivity rate among first-testers was 1.2%. Youths < 25 years had a lower seroprevalence (0.4%) than older people (2.6% and 2.7% for those aged 25–39 and those aged ≥ 40 years, respectively), p < 0.001. Seropositivity was negatively associated with secondary distribution, workplace model, community model and age < 25 years. On the other hand, partners of PLHIV model, HTS model, female sex and first-time-testers were positively associated with seropositivity. In Cameroon, oral HIVST is an effective approach for identifying undiagnosed PLHIV, especially when using ANC/PNC/MCHC, partners of PLHIV and HTS distribution models. However, to ensure the successful scale-up of HIVST in Cameroon, guidelines should be revised to fine-tune the target populations for HIVST and optimize the use of resources.
Delineating the effective use of self-supervised learning in single-cell genomics
Authors: Richter Till , Bahrami Mojtaba , Xia Yufan , Fischer David S. , Theis Fabian J.
Published: December 2024

Self-supervised learning (SSL) has emerged as a powerful method for extracting meaningful representations from vast, unlabelled datasets, transforming computer vision and natural language processing. In single-cell genomics (SCG), representation learning offers insights into the complex biological data, especially with emerging foundation models. However, identifying scenarios in SCG where SSL outperforms traditional learning methods remains a nuanced challenge. Furthermore, selecting the most effective pretext tasks within the SSL framework for SCG is a critical yet unresolved question. Here we address this gap by adapting and benchmarking SSL methods in SCG, including masked autoencoders with multiple masking strategies and contrastive learning methods. Models trained on over 20 million cells were examined across multiple downstream tasks, including cell-type prediction, gene-expression reconstruction, cross-modality prediction and data integration. Our empirical analyses underscore the nuanced role of SSL, namely, in transfer learning scenarios leveraging auxiliary data or analysing unseen datasets. Masked autoencoders excel over contrastive methods in SCG, diverging from computer vision trends. Moreover, our findings reveal the notable capabilities of SSL in zero-shot settings and its potential in cross-modality prediction and data integration. In summary, we study SSL methods in SCG on fully connected networks and benchmark their utility across key representation learning scenarios.
A ganglioside-based immune checkpoint enables senescent cells to evade immunosurveillance during aging
Authors: Iltis Charlène , Moskalevska Iryna , Debiesse Antoine , Seguin Laetitia , Fissoun Christina , Cervera Ludovic , Moudombi Lyvia , Ardin Maude , Ferrari Anthony , Eliott Coline , Pisani Didier , Ottaviani Alexandre , Bourinet Manon , Luci Carmelo , Gual Philippe , Makulyte Gabriela , Bernard David , Durandy Manon , Duret Lou C. , Hamidouche Tynhinane , Kunz Sarah , Croce Olivier , Delannoy Clément , Guérardel Yann , Allain Fabrice , Hofman Paul , Benarroch-Popivker Delphine , Bianchini Laurence , Dadone-Montaudie Berengère , Cosson Estelle , Guglielmi Julien , Pourcher Thierry , Braud Véronique M. , Shkreli Marina , Pers Yves-Marie , Jorgensen Christian , Brondello Jean-Marc , Féral Chloé C. , Michallet Marie-Cécile , Gilson Eric , Cherfils-Vicini Julien
Published: December 2024

Although senescent cells can be eliminated by the immune system, they tend to accumulate with age in various tissues. Here we show that senescent cells can evade immune clearance by natural killer (NK) cells by upregulating the expression of the disialylated ganglioside GD3 at their surface. The increased level of GD3 expression on senescent cells that naturally occurs upon aging in liver, lung, kidney or bones leads to a strong suppression of NK-cell-mediated immunosurveillance. In mice, we found that targeting GD3+ senescent cells with anti-GD3 immunotherapy attenuated the development of experimentally induced or age-related lung and liver fibrosis and age-related bone remodeling. These results demonstrate that GD3 upregulation confers immune privilege to senescent cells. We propose that GD3 acts as a senescence immune checkpoint (SIC) that allows senescent cells to escape immunosurveillance and to trigger immune anergy during aging.
Oxygen reduction reaction kinetics of platinum-based catalysts under stress induction
Authors: Jiang Haibo , Lu Jiyuan , Bi Liyuan , Zhang Lili , Yang Jiajia , Liu Cui , Yu Shengwei , Shen Jianhua , Zhu Yihua
Published: December 2024

The ORR kinetic optimization for PtNi and PtPb catalysts is conferred by stress induction.
Coordination polymers constructed from bis-pyridyl-bis-amides and 1,4,5,8-naphthalenetetracarboxylic acid: ligand transformation and metal ion sensing
Authors: Chen Wei-Hao , Chen Yen-Hsin , Thapa Kedar Bahadur , Liu Shih-Miao , Chen Jhy-Der
Published: December 2024

Ligand transformations are observed in the coordination polymers constructed from bis-pyridyl-bis-amides (L1–L5) and 1,4,5,8-naphthalenetetracarboxylic acid.
Theoretical investigation of the A1Π–X1Σ+, B1Σ+–X1Σ+, C1Σ+–X1Σ+, and E1Π–X1Σ+ transitions of the CO molecule
Authors: Khalil Malathe , Mahmoud Salman , Brady Ryan P. , Almehairbi Mubarak , Gacesa Marko , Yurchenko Sergei N. , Tennyson Jonathan , Al Ghaferi Amal , El-Kork Nayla
Published: December 2024

Potential energy and dipole moment curves for CO are calculated using a high level theory and diabatised. The resulting curves are used to compute electronic spectra of CO found in agreement with laboratory and astronomical observations.
Structure factor line shape model gives approximate nanoscale size of polar aggregates in pyrrolidinium-based ionic liquids
Authors: Wheeler Ralph A. , Dalbey Emily E.
Published: December 2024

Half-lengths, where g(r) decreases to half its maximum value, provide a mathematically and physically well-defined measure of aggregate size.
Theoretical and machine learning models for reaction-barrier predictions: acrylate and methacrylate radical reactions
Authors: Takagi Makito , Shimazaki Tomomi , Kobayashi Osamu , Ishimoto Takayoshi , Tachikawa Masanori
Published: December 2024

We propose density functional theory (DFT)- and random forest (RF)-based theoretical and machine learning (ML) models, respectively, for predicting reaction barriers (ΔETS) using acrylate and methacrylate radical reactions as representatives.
Performance enhancement of InSnZnO thin-film transistors by modifying the dielectric–semiconductor interface with colloidal quantum dots
Authors: Chen Sijie , Chen Haoran , Xia Chenghui , Sun Zhenhua
Published: December 2024

Transistors featuring ALD-grown Al2O3 dielectric and sputtered ITZO semiconductor layers are enhanced by spin-coated colloidal quantum dots, which effectively passivate the dielectric/semiconductor interface, leading to performance improvements.
NiCr-LDH/V4C3 MXene nanocomposites as an efficient electrocatalyst for urea oxidation
Authors: Abraham Dana Susan , Vinoba Mari , Bhagiyalakshmi Margandan
Published: December 2024

NiCr-LDH/MXene nanocomposites are developed as electrocatalysts to improve the performance of direct urea fuel cells (DUFCs), offering a sustainable solution by converting urea-rich waste into clean energy.
Continuum elasticity and molecular dynamics of a pore in archaeal bolalipid membranes
Authors: Galimzyanov Timur R. , Volynsky Pavel E. , Batishchev Oleg V.
Published: December 2024

Molecular dynamics simulations of the pore closure in a bolalipid membrane.
The swelling mechanism of ethylene-vinyl acetate polymer in different solvents via molecular dynamics and experimental studies
Authors: Luo Rui , Miao Jinniu , Zhao Yihan , Chen Shengbin , Yang Yang , Lu Qiang , Hu Bin , Zhang Bing , Liu Ji
Published: December 2024

Among the three solvents, the swelling degree of photovoltaic modules follows the same pattern with the interaction energies between EVA and solvents, consistently showing the trend: d-limonene > ethanol > water.
Activity waves in condensed excitable phases of Quincke rollers
Authors: Zhang Meng Fei , Fan Bao Ying , Zhang Chuan Yu , Chen Kang , Tian Wen-de , Zhang Tian Hui
Published: December 2024

Sound waves propagate by splitting. Shock waves propagate by a local density-dependent memory.
Mo-doped ZnO NPs with NIR light enhance peroxidase-like nanozymes and trigger photothermal for bacteria eradication
Authors: Xu Yini , Wei Jinya , Yang Dezhi , Song Yuzhu , Yang Yaling
Published: December 2024

We developed Mo/ZnO NPs with excellent POD-like activity to inhibit both Gram-negative and Gram-positive bacteria. Mo/ZnO NPs show enhanced antibacterial effects and superior photothermal properties under NIR-I laser exposure.
Production of linear alkanes via the solid-state hydrogenation of interstellar polyynes
Authors: Fedoseev G. , Li X. , Baratta G. A. , Palumbo M. E. , Chuang K.-J.
Published: December 2024

Context. Highly unsaturated carbon chains, including polyynes, have been detected in many astronomical regions and planetary systems. With the success of the QUIJOTE survey of the Taurus Molecular Cloud-1 (TMC-1), the community has seen a “boom” in the number of detected carbon chains. On the other hand, the Rosetta mission revealed the release of fully saturated hydrocarbons, C3H8, C4H10, C5H12, and (under specific conditions) C6H14 with C7H16, from the comet 67P/Churyumov-Gerasimenko. The detection of the latter two is attributed to dust-rich events. Similarly, the analysis of samples returned from asteroid Ryugu by Hayabusa2 mission indicates the presence of long saturated aliphatic chains in Ryugu’s organic matter.

Aims. The surface chemistry of unsaturated carbon chains under conditions resembling those of molecular clouds can provide a possible link among these independent observations. However, laboratory-based investigations to validate such a chemistry is still lacking. In the present study, we aim to experimentally verify the formation of fully saturated hydrocarbons by the surface hydrogenation of C2nH2(n > 1) polyynes under ultra-high vacuum conditions at 10 K.

Methods. We undertook a two-step experimental technique. First, a thin layer of C2H2 ice was irradiated by UV-photons (≥121 nm) to achieve a partial conversion of C2H2 into larger polyynes: C4H2 and C6H2. Afterwards, the obtained photoprocessed ice was exposed to H atoms to verify the formation of various saturated hydrocarbons.

Results. In addition to C2H6, which was investigated previously, the formation of larger alkanes, including C4H10 and (tentatively) C6H14, is confirmed by our study. A qualitative analysis of the obtained kinetic data indicates that hydrogenation of HCCH and HCCCCH triple bonds proceeds at comparable rates, given a surface temperature of 10 K. This can occur on the timescales typical for the dark cloud stage. A general pathway resulting in formation of other various aliphatic organic compounds by surface hydrogenation of N- and O-bearing polyynes is also proposed. We also discuss the astrobiological implications and the possibility of identifying alkanes with JWST.
Features of the low-frequency internal friction in solid hydrogen
Authors: Marinin G. A. , Leont’eva A. V. , Sukharevskiĩ B. Ya. , Anisimova T. N. , Prokhorov Yu. A.
Published: December 2024

The temperature dependence of the low-frequency internal friction (LFIF) and shear modulus G in the temperature range 2–12.5 K have been studied in free-standing specimens of normal hydrogen, n-H2, by the inverted torsional pendulum method. Peaks were found in the LFIF at T≈ 5.5 and ≈ 9 K and also an increase in the internal friction background below 8 K . Over the whole temperature interval studied, the shear modulus and its low values are relatively constant. The anomalous behavior of the LFIF and G in n-H2 (compa red with the classical Ar) is associated with an increase in the mobility of defects in the low-temperature region and with an appreciable contribution of quantum fluctuations in internal friction processes in solid hydrogen at low temperatures.
Stationary state in a Josephson SNS junction in the presence of current and heat flow
Authors: Ryazanov V. V. , Ustinov A. V.
Published: December 2024

The form of the boundary of the region of the stationary state in the current-heat phase plane for a distributed superconductor–normal metal–superconductor Josephson junction is studied theoretically and experimentally. It is shown that when heat flows uniformly through the junction, the thermoelectric current Js distributed uniformly along the junction interacts with the edge current I. The results of a numerical calculation and an analytic analysis for Js ≫ Jc. indicate that the width of the region of the stationary state oscillates with a period, with respect to the current, which decreases as the width of the junction w increases. A chain of Josephson vortices with a nonuniform density appears in the junction: They are stretched at the center of the junction and are compressed near its edges. A calculation for a uniform junction and a two-dimensional junction with radial symmetry is performed. The experimental results, obtained for tantalum–copper–tantalum junctions are in qualitative agreement with the theory; the period of the observed oscillations agrees with the calculated period.
Point-contact spectra of 2H-NbSe2 in the superconducting state
Authors: Bobrov N. L , Rybal’chenko L. F. , Obolenskii M. A. , Fisun V. V.
Published: December 2024

A qualitative study of the electron-phonon interaction (EPI) spectra in 2H-NbSe2 is carried out by the method of point-contact spectroscopy in the superconducting state. Anisotropy of the EPI spectra for contacts oriented in the principal crystallographic directions (along the c axis and parallel to the basal surface) was observed. Approximate values of the positions of the main features in the phonon density of states were established for both directions. The additional low-frequency peaks observed in the spectra for separate crystallographic orientations are associated with the collective oscillations of the amplitude and phase of charge density waves.
Structural phase transitions in planar bilayer crystals with long range interaction
Authors: Vil’k Yu. M. , Monarkha Yu. P.
Published: December 2024

We have studied theoretically a bilayer electronic crystal, which may be realized in a stratifying mixture of helium isotopes or in a superfluid helium film. In the limiting cases of weak and intermediate coupling between the layers we have studied the dynamics of such a crystal and described a structural transition at which the transverse sound velocity decreases and goes to zero. It is shown that in the strong coupling limit between the layers the system becomes equivalent to a two-dimensional binary mixture on a triangular Ising lattice with a long range potential of mixing V∼r−3. We have studied the phase transitions which arise in such a binary mixture as the temperature and concentration are varied. It is shown that as the temperature is lowered from the disordered phase a superstructure (√3×√3) always appears first. A (2×2) superstructure is unstable with respect to formation of antiphase domains.
The field dependence of the “freezing” temperature of spin glasses
Authors: Vedyaev A. V. , Cherenkov V. A.
Published: December 2024

It is shown that for most spin glasses the shift in the “freezing” temperature depends quadratically on the magnitude of the external field, which corresponds to the ideas of the classical theory of Néel superparamagnetism and molecular field theories with an infinite radius of interaction.
Spontaneous formation of vortices in superconducting antiferromagnets
Authors: Buzdin A. I.
Published: December 2024

It is shown that vortices can arise on the domain walls in superconducting antiferromagnets. The properties of such a vortex state are considered. The experimental possibilities of finding this effect are discussed.
Phase transitions in a system of magnetic rotors
Authors: Brodyanskii A. P. , Freiman Yu. A.
Published: December 2024

We consider a system of rotors in which, in addition to the usual anisotropy of the interaction, there is a magnetic exchange interaction which depends on the mutual orientation of the molecules. We show that in such a system, in addition to the magnetic and orientational phase transitions, a new class of orientational–magnetic transitions is possible.
Point defect effects in AlGaN 270-nm light emitting diodes introduced by MeV electron and proton irradiation
Authors: Polyakov A. Y. , Alexanyan L. A. , Schemerov I. V. , Vasilev A. A. , Chernykh A. V. , Ivanov Anton , Talnishnikh Nadezhda , Chernyakov Anton , Zakgeim A. L. , Shmidt N. M. , Lagov P. B. , Doroshkevich A. S. , Isayev R. Sh. , Pavlov Yu. S. , Wan Hsiao-Hsuan , Ren Fan , Pearton S. J.
Published: December 2024

Point defects were controllably introduced into 270 nm AlGaN Light-Emitting Diodes (LEDs) by 5 MeV electron and 1.1 MeV proton irradiations to examine the effect on electrical and luminescent characteristics. The 5 MeV electron irradiations had only a marginal effect on the charge distribution, current flow, and electroluminescence of LEDs for electron fluences up to 4.5 × 1016 e/cm2 that cause very strong degradation in green, blue, and near-UV LEDs. This lack of changes is attributed to the much higher charge densities in quantum-wells (QWs) and quantum barriers (QBs) of the 270 nm LEDs and to higher bond strength in high Al mole fraction AlGaN layers. By contrast, irradiation with 1.1 MeV protons with a fluence of 1016 p/cm2 leads to more than two orders of magnitude decrease in charge density in the QWs and QBs, a strong increase in the series resistance, and the emergence of deep electron traps near Ec-0.5 eV. The difference is explained by a much higher density of primary defects produced by protons. The observed effects are compared to changes in performance caused by aging after high driving current.
A molecular dynamics study of the local structure evolution with temperature in Gd-doped CeO2: Focus on the bond length
Authors: Vives Serge , Ramel David , Meunier Cathy
Published: December 2024

Since the long-range structure of the Gd-doped system (Ce1−xGdxO2−x/2) remains in the fluorite structure in the x-range [0–0.3], it is of interest to study this system in the local range. Molecular dynamics simulations seem to be particularly suitable for this purpose. Among all the possible parameters used to describe the local order/disorder, we focus on the behavior of the bond lengths. Doping cations and oxygen vacancies are introduced inside the fluorite structure following two arrangements, the random (R) and the neighbor (N). We investigate the evolution of the bond lengths with the temperature and doping level and identify different trends depending on the bond type (cation–anion, cation–cation). The bond length thermal expansion can be drastically different from the long-range thermal expansion mainly for the bonds implying Gd3+ cation. The presence of C-type Gd2O3 clusters is discussed through the study of the double component of the Gd–Gd Radial Distribution Function. Comments are provided for evolution of distances beyond the first and second shells of the cations’ environment. This study also demonstrates the impact of point defect distribution (R or N) on the evolution of the local structure, while maintaining the long-range fluorite structure.
Topology optimization of self-supporting metamaterials for additive manufacturing: a novel framework and validation
Authors: Zheng Ran , Yi Bing , Liu Wenlong , Liu Long , Peng Xiang , Tao Yong
Published: December 2024

Topology optimization (TO) for additive manufacturing (AM) often faces challenges related to overhang structures, increasing build time, material costs, and the need for support structures. This paper proposes a novel framework for designing and manufacturing two- and three-dimensional self-supporting metamaterials that eliminate the requirement for additional support during AM. By integrating an AM filter into the TO process, homogenization methods for evaluating elasticity properties, and a symmetry constraint to ensure connectivity between periodic unit cells, we demonstrate optimized self-supporting metamaterials. Manufacturability is verified through fused deposition modeling, and mechanical compression experiments confirm the performance of the resulting metamaterials. The approach offers a cost-effective and time-efficient solution for fabricating complex metamaterials without auxiliary supports.
Numerical analysis of dipole-induced interactions in casson micropolar ferrofluids: Impacts on fluid flow and heat transfer under external magnetic fields
Authors: Kamran Abid , Azhar Ehtsham , Afaq Harsa
Published: December 2024

This study examines micropolar ferrofluids containing microstructures under the influence of an external magnetic field. The presence of ferroparticles and the magnetic field can lead to the generation of dipoles among these particles, which may significantly affect the fluid flow and heat transfer properties of the ferrofluid. The research utilizes a mathematical framework incorporating the equations of mass, momentum, angular momentum, and energy, alongside Maxwell’s equations of electromagnetism. This framework leads to a system of partial differential equations, which are subsequently converted into ordinary differential equations and solved using the BVP4C numerical method. The results, presented through graphs and tables, demonstrate how variations in physical parameters related to microstructures, dipole interactions, and the Casson fluid model influence fluid flow and heat transfer characteristics. The findings show that the fluid’s skin friction increases with higher micro-rotation and fluid parameters, while it decreases with a stronger magnetic parameter along the plate. The angular velocity of the ferrofluid increases due to the presence of a larger number of microstructures near the wall, which contribute to higher angular velocity gradients.
Analytical study of optical soliton solutions for a (2+1)-nonlinear coupled Konopelchenko-Dubrovsky equation in the tropical and mid-latitude tropospheres
Authors: Hussain Ejaz , Raees Nida , Mahmood Irfan , Malik Sandeep , Ibrahim A. , Saad H.-E M. Musa
Published: December 2024

This research work investigates the analytical soliton solution of $(2+1)$-dimensions of the Konopelchenko-Dubrovsky (KD) equation which depicts the nonlinear waves in mathematical physics with weak dispersion. The $(2+1)$-dimensional KD equation significantly enhances the discipline of atmospheric science by examining the characteristics of nonlinear wave phenomena, elucidating the intricate scattering effects and prolonged range interactions prevalent in tropical and mid-latitude atmospheric regions. This mathematical formulation yields a profound understanding of the interaction between equatorial and mid-latitude Rossby waves, effectively capturing their intricate dynamics and interrelations. We used the newly developed schemes known as the generalized Arnous and the $\exp(-\Theta(\mathcal{G}))$-expansion methods to find the analytical soliton solutions. Consequently, various novel collections of solutions, trigonometric, hyperbolic, rational, and logarithmic solutions, are identified. From these methodologies, we derive the kink and anti-kink soliton solutions. The kink soliton pertains to localized alterations in the curvature, amplitude, and morphology of the wave. This particular category of soliton signifies the existence of a pronounced transition between disparate wave height configurations. To gain a deeper understanding of the physical characteristics of these solutions, we present them with various visual representations such as 3D, 2D, contour, and density graphs. These methods have larger applicability and are useful for the $(2+1)$-dimensional KD equation expressing nonlinear physical models in the realm of nonlinear sciences rather than just the equation itself.
Enhanced stabilization performances of an open quantum battery in a photonic band-gap environment
Authors: Hao Xiang
Published: December 2024

We investigate the stabilization mechanism of open quantum batteries driven by a classical field in the weak or strong system-reservoir coupling regime. A protocol to improve the steady-state energy storage performance is proposed by engineering the spectral density of a band-gap environment which is described as the superposition of two inhomogeneous Lorentzian spectrums with different weights. We find out that the interplay between the battery-environment bound state and the reservoir memory effect plays a crucial role in the stabilization performance against the energy dissipation. The formation of the bound state and the non-Markovian effect will be strengthened by adjusting the weights of the environment spectral density. In the charging process, the classical field contributes to enhancing the steady ergotropy. Moreover, the manipulation of the spectrum weights results in the speedup scheme of carrying out the energy storage due to the existence of bound states. In the self-discharging process, increasing the spectral weight allows the battery to maintain a higher steady ergotropy. These results provide a practical approach to achieving optimal quantum batteries with a better stabilization performance.
GHZ state, spin squeezed state, and spin coherent state for frequency estimation under general Gaussian noises
Authors: Chai Qi , Yang Wen
Published: December 2024

Exploring the quantum advantages of various non-classical quantum states in noisy environments is a central subject in quantum sensing. Here we provide a complete picture for the frequency estimation precision of three important states (the GHZ state, maximal spin squeezed state, and spin coherent state) of a spin-S under both individual dephasing and collective dephasing by general Gaussian noise, ranging from the Markovian limit all over to the extreme non-Markovian limit. It turns out that no matter whether or not the noise is Markovian, the spin coherent state is always worse than the classical scheme under collective dephasing although it is equivalent to the classical scheme under individual dephasing. Moreover, the maximal spin squeezed state always give the best sensing precision (and outperforms the widely studied GHZ state) in all cases. This establish the general advantage of the spin squeezed state for noisy frequency estimation in many quantum sensing platforms.