bluuebunny/crossref_metadata_2025_split huggingface dataset:
Inflation with the Chern-Simons term in the Palatini formulation
Authors: Hassan Ali , Räsänen Syksy 
Published: January 2025

Abstract
We consider the Chern-Simons term coupled to the inflaton in the Palatini formulation of general relativity. In contrast to the metric formulation, here the Chern-Simons term affects also the background evolution. We approximately solve for the connection, insert it back into the action, and reduce the order of the equations to obtain an effective theory in the gradient approximation. We consider three cases: when the connection is unconstrained, and when non-metricity or torsion is put to zero. In the first two cases, the inflaton kinetic term is modified with a term proportional to the square of the potential. For polynomial potentials dominated by the highest power of the field, the Chern-Simons term solves the problem that higher order corrections spoil the flatness of the potential. For Higgs inflation, the tensor-to-scalar ratio can be as large as the current observational bound, and the non-minimal coupling to the Ricci scalar can be as small as in the metric case. The Palatini contribution cures the known instability of the tensor modes due to the Chern-Simons term in the metric formulation.
Revisiting primordial magnetic fields through 21-cm physics: bounds and forecasts
Authors: Bhaumik Arko , Paul Debarun , Pal Supratik 
Published: January 2025

Abstract
Primordial magnetic fields (PMFs) may significantly influence 21-cm physics via two mechanisms: (i) magnetic heating of the intergalactic medium (IGM) through ambipolar diffusion (AD) and decaying magnetohydrodynamic turbulence (DT), (ii) impact on the star formation rate density (SFRD) through small-scale enhancement of the matter power spectrum. In this analysis, we integrate both of these effects within a unified analytical framework and use it to determine upper bounds on the parameter space of a nearly scale-invariant non-helical PMF in the light of the global 21-cm signal observed by EDGES. Our findings reveal that the joint consideration of both effects furnishes constraints of the order B
0 ≲ 𝒪(10-2) nG on the present-day magnetic field strength, which are considerably tighter compared to earlier analyses. We subsequently explore the prospects of detecting such a magnetized 21-cm power spectrum at the upcoming SKA-Low mission. For the relevant parameters of the PMF (B
0 and n

B
) and the excess radio background (ξ), SNR estimation and Fisher forecast analysis indicate that it may be possible to constrain these three parameters with relative 1σ uncertainties ≲ 10% and an associated SNR ≳10 at SKA-Low. This also leads to possible correlations among these three parameters, thus revealing intriguing trends of interplay among the various physical processes involved.
Schwarzschild lensing from geodesic deviation
Authors: Li Zhao , Guo Xiao , Liu Tan , Zhu Tao , Zhao Wen 
Published: January 2025

Abstract
We revisit the gravitational lensing of light or gravitational waves by a Schwarzschild black hole in geometric optics. Rather than focusing on a single massless particle, we investigate the collective behavior of a congruence of light or gravitational rays, described by the geodesic deviation equation (GDE). By projecting GDE onto the Newman-Penrose tetrad, we decouple the equation and find an analytical Dyson-like series solution in the weak deflection and thin lens limits. Using this solution, we analyze the evolution of the cross-sectional area and axis ratio. Finally, we reproduce the magnification and axis ratio of the lensing images up to second-order weak deflection approximation, addressing some previously overlooked corrections.
Numerical simulation of common envelope stage in close binary systems: comparison between Newtonian and modified gravity
Authors: Astashenok A.V. , Baigashov A.S. , Tepliakov A.S. , Gusev K.P. , Shamardina E.R. 
Published: January 2025

Abstract
We consider the important stage in evolution of close binary system namely common envelope
phase in framework of various models of modified gravity. The comparison of results between
calculations in Newtonian gravity and modified gravity allows to estimate possible observational
imprints of modified gravity. Although declination from Newtonian gravity should be negligible we
can propose that due to the long times some new effects can appear. We use the moving-mesh code
AREPO for numerical simulation of binary system consisting of ∼ M
⊙ white dwarf and a
red giant with mass ∼ 2M
⊙. For implementing modified gravity into AREPO code we
apply the method of (pseudo)potential, assuming that modified gravity can be described by small
corrections to usual Newtonian gravitational potential. As in Newtonian case initial orbit has to
shrink due to the energy transfer to the envelope of a giant. We investigated evolution of common
envelope in a case of simple model of modified gravity with various values of parameters and
compared results with simulation in frames of Newtonian gravity.
Integration of wearable electronics and heart rate variability for human physical and mental well-being assessment
Authors: Yin Feifei , Chen Jian , Xue Haiying , Kang Kai , Lu Can , Chen Xinyi , Li Yang 
Published: January 2025

Abstract
Heart rate variability (HRV) that can reflect the dynamic balance between the sympathetic nervous and parasympathetic nervous of human autonomic nervous system (ANS) has attracted considerable attention. However, traditional electrocardiogram (ECG) devices for HRV analysis are bulky, and hard wires are needed to attach measuring electrodes to the chest, resulting in the poor wearable experience during the long-term measurement. Compared with that, wearable electronics enabling continuously cardiac signals monitoring and HRV assessment provide a desirable and promising approach for helping subjects determine sleeping issues, cardiovascular diseases, or other threats to physical and mental well-being. Until now, significant progress and advances have been achieved in wearable electronics for HRV monitoring and applications for predicting human physical and mental well-being. In this review, the latest progress in the integration of wearable electronics and HRV analysis as well as practical applications in assessment of human physical and mental health are included. The commonly used methods and physiological signals for HRV analysis are briefly summarized. Furthermore, we highlighted the research on wearable electronics concerning HRV assessment and diverse applications such as stress estimation, drowsiness detection, etc. Lastly, the current limitations of the integrated wearable HRV system are concluded, and possible solutions in such a research direction are outlined.
Electrospraying Si/SiO
x
/C and Sn/C nanosphere arrays on carbon cloth for high-performance flexible lithium-ion batteries
Authors: Chen Di , Li Rui , Liu Chunxue , Jiang Kai 
Published: January 2025

Abstract
Exploring electrode materials with larger capacity, higher power density and longer cycle life was critical for developing advanced flexible lithium-ion batteries (LIBs). Herein, we used a controlled two-step method including electrospraying followed with calcination treatment by CVD furnace to design novel electrodes of Si/Si
x
/C and Sn/C microrods array consisting of nanospheres on flexible carbon cloth substrate (denoted as Si/Si
x
/C@CC, Sn/C@CC). Microrods composed of cumulated nanospheres (the diameter was approximately 120 nm) had a mean diameter of approximately 1.5 µm and a length of around 4.0 µm, distributing uniformly along the entire woven carbon fibers. Both of Si/Si/Si
x
/C@CC and Sn/C@CC products were synthesized as binder-free anodes for Li-ion battery with the features of high reversible capacity and excellent cycling. Especially Si/Si
x
/C electrode exhibited high specific capacity of about 1750 mA∙h∙g−1 at 0.5 A∙g−1 and excellent cycling ability even after 1050 cycles with a capacity of 1388 mA∙h∙g−1. Highly flexible Si/Si
x
/C@CC//LiCoO2 batteries based on liquid and solid electrolytes were also fabricated, exhibiting high flexibility, excellent electrical stability and potential applications in flexible wearable electronics.
Artificial self-powered and self-healable neuromorphic vision skin utilizing silver nanoparticle-doped ionogel photosynaptic heterostructure
Authors: Qian Xinkai , Zhang Fa , Li Xiujuan , Li Junyue , Sun Hongchao , Wang Qiye , Huang Chaoran , Zhang Zhenyu , Zhou Zhe , Liu Juqing 
Published: January 2025

Abstract
Artificial skin should embody a softly functional film that is capable of self-powering, healing and sensing with neuromorphic processing. However, the pursuit of a bionic skin that combines high flexibility, self-healability, and zero-powered photosynaptic functionality remains elusive. In this study, we report a self-powered and self-healable neuromorphic vision skin, featuring silver nanoparticle-doped ionogel heterostructure as photoacceptor. The localized surface plasmon resonance induced by light in the nanoparticles triggers temperature fluctuations within the heterojunction, facilitating ion migration for visual sensing with synaptic behaviors. The abundant reversible hydrogen bonds in the ionogel endow the skin with remarkable mechanical flexibility and self-healing properties. We assembled a neuromorphic visual skin equipped with a 5 × 5 photosynapse array, capable of sensing and memorizing diverse light patterns.
Neurotransmitter-mediated artificial synapses based on organic electrochemical transistors for future biomimic and bioinspired neuromorphic systems
Authors: Cheng Miao , Xie Yifan , Wang Jinyao , Jin Qingqing , Tian Yue , Liu Changrui , Chu Jingyun , Li Mengmeng , Li Ling 
Published: January 2025

Abstract
Organic electrochemical transistors have emerged as a solution for artificial synapses that mimic the neural functions of the brain structure, holding great potentials to break the bottleneck of von Neumann architectures. However, current artificial synapses rely primarily on electrical signals, and little attention has been paid to the vital role of neurotransmitter-mediated artificial synapses. Dopamine is a key neurotransmitter associated with emotion regulation and cognitive processes that needs to be monitored in real time to advance the development of disease diagnostics and neuroscience. To provide insights into the development of artificial synapses with neurotransmitter involvement, this review proposes three steps towards future biomimic and bioinspired neuromorphic systems. We first summarize OECT-based dopamine detection devices, and then review advances in neurotransmitter-mediated artificial synapses and resultant advanced neuromorphic systems. Finally, by exploring the challenges and opportunities related to such neuromorphic systems, we provide a perspective on the future development of biomimetic and bioinspired neuromorphic systems.
Recent progress on elemental tellurium and its devices
Authors: Liao Jiachi , Lai Zhengxun , Meng You , Ho Johnny C. 
Published: January 2025

Abstract
The rapid advancement of information technology has heightened interest in complementary devices and circuits. Conventional p-type semiconductors often lack sufficient electrical performance, thus prompting the search for new materials with high hole mobility and long-term stability. Elemental tellurium (Te), featuring a one-dimensional chiral atomic structure, has emerged as a promising candidate due to its narrow bandgap, high hole mobility, and versatility in industrial applications, particularly in electronics and renewable energy. This review highlights recent progress in Te nanostructures and related devices, focusing on synthesis methods, including vapor deposition and hydrothermal synthesis, which produce Te nanowires, nanorods, and other nanostructures. Critical applications in photodetectors, gas sensors, and energy harvesting devices are discussed, with a special emphasis on their role within the internet of things (IoT) framework, a rapidly growing field that is reshaping our technological landscape. The prospects and potential applications of Te-based technologies are also highlighted.
Recent progress on artificial intelligence-enhanced multimodal sensors integrated devices and systems
Authors: Wang Haihua , Zhou Mingjian , Jia Xiaolong , Wei Hualong , Hu Zhenjie , Li Wei , Chen Qiumeng , Wang Lei 
Published: January 2025

Abstract
Multimodal sensor fusion can make full use of the advantages of various sensors, make up for the shortcomings of a single sensor, achieve information verification or information security through information redundancy, and improve the reliability and safety of the system. Artificial intelligence (AI), referring to the simulation of human intelligence in machines that are programmed to think and learn like humans, represents a pivotal frontier in modern scientific research. With the continuous development and promotion of AI technology in Sensor 4.0 age, multimodal sensor fusion is becoming more and more intelligent and automated, and is expected to go further in the future. With this context, this review article takes a comprehensive look at the recent progress on AI-enhanced multimodal sensors and their integrated devices and systems. Based on the concept and principle of sensor technologies and AI algorithms, the theoretical underpinnings, technological breakthroughs, and pragmatic applications of AI-enhanced multimodal sensors in various fields such as robotics, healthcare, and environmental monitoring are highlighted. Through a comparative study of the dual/tri-modal sensors with and without using AI technologies (especially machine learning and deep learning), AI-enhanced multimodal sensors highlight the potential of AI to improve sensor performance, data processing, and decision-making capabilities. Furthermore, the review analyzes the challenges and opportunities afforded by AI-enhanced multimodal sensors, and offers a prospective outlook on the forthcoming advancements.
Advancements in implantable temperature sensors: Materials, mechanisms, and biological applications
Authors: Yang Zhuofan , Song Hongcheng , Ding He 
Published: January 2025

Abstract
Implantable temperature sensors are revolutionizing physiological monitoring and playing a crucial role in diagnostics, therapeutics, and life sciences research. This review classifies the materials used in these sensors into three categories: metal-based, inorganic semiconductor, and organic semiconductor materials. Metal-based materials are widely used in medical and industrial applications due to their linearity, stability, and reliability. Inorganic semiconductors provide rapid response times and high miniaturization potential, making them promising for biomedical and environmental monitoring. Organic semiconductors offer high sensitivity and ease of processing, enabling the development of flexible and stretchable sensors. This review analyzes recent studies for each material type, covering design principles, performance characteristics, and applications, highlighting key advantages and challenges regarding miniaturization, sensitivity, response time, and biocompatibility. Furthermore, critical performance parameters of implantable temperature sensors based on different material types are summarized, providing valuable references for future sensor design and optimization. The future development of implantable temperature sensors is discussed, focusing on improving biocompatibility, long-term stability, and multifunctional integration. These advancements are expected to expand the application potential of implantable sensors in telemedicine and dynamic physiological monitoring.
Optimizing Railway Safety by Analyzing Human Reliability Techniques - A review
Authors: Aliza M. E. M. , Yusop A. F. , Hamidi M. A. , Nor M. A. M. 
Published: January 2025

Abstract
Human reliability analysis (HRA) is a critical component in ensuring the safety and efficiency of railway engineering. As railway systems grow more complex, the methodologies used to assess and improve human reliability must also advance. This review provides a comprehensive analysis of the evolution of HRA, from the first-generation techniques to the third-generation approaches currently in use. Through a broad survey of the literature, comparative analysis, and detailed case studies, this review traces the development of HRA methods, showing the evolution from traditional techniques to modern hybrid approaches. The review also emphasizes the significance of hybrid Human Error Assessment and Reduction Technique (HEART) methods, which integrate multiple HRA approaches to provide a more comprehensive and accurate assessment of human reliability. The hybrid technique offers a more accurate estimation than standard methods, as evidenced by the determined Pearson coefficient of 0.9990 between the simulation findings and the HEP values of HEART-related methodologies. It also explores the integration of human factors into railway safety systems, underscoring the importance of considering human-machine interactions and the cognitive and behavioural aspects of railway operations. Key findings indicate that while traditional HRA methods laid the groundwork, there is a growing need for continuous innovation to address the increasing complexity of railway systems. This includes the development of hybrid models that combine insights from various HRA techniques and the incorporation of advanced human-machine interaction paradigms to further minimize human error rates. The objective of this review is to offer recommendations for future research in the field of HRA for railway engineering. It advocates for the development of advanced hybrid models with the use of cutting-edge technology like machine learning and artificial intelligence. By combining historical insights with modern technological advancements, the goal is to create more robust and reliable HRA methods that can better support the safety and efficiency of railway operations.
Implementation and Validation of the Cantas Electro’S Vibration Reduction Mechanism
Authors: Saad Wan Aliff Abdul , Idris Nurzarifah Zakirah , Ahmad Zair Asrar , Hasan Muhammad Danial Abu , Isham Muhammad Firdaus , Talib Mat Hussin Ab , Saufi Mohd Syahril Ramadhan Mohd , Samsuri Saiful Farhan Mohd 
Published: January 2025

Abstract
The Malaysian palm oil industry has grown substantially, emphasizing the need for efficient harvesting within a 10–12-day cycle. The CANTAS motorized cutter, introduced in 2007, has enhanced productivity by harvesting fresh fruit bunches from trees up to seven meters high. This research focuses on reducing health risks from Hand-Arm Vibration Syndrome (HAVS) by validating vibration reduction strategies for the CANTAS tool. The study investigates the performance of different design and use materials thermoplastic polyurethane (TPU), used in rubber bushings (RB), webbing bushings (WB), and a combination of rubber and webbing bushings (CRWB). Using triaxial accelerometers, the results demonstrate significant reductions in HAV levels, contributing to improved worker safety and operational efficiency.
Material and technique fundamentals of nano-hydroxyapatite coatings towards biofunctionalization: a review
Authors: Phogat Durgesh , Awasthi Shikha 
Published: January 2025

Abstract
Hydroxyapatite (HAp) nanocoatings on titanium alloys (e.g. Ti6Al4V) have been used for prosthetic orthopaedic implants in recent decades because of their osseointegration, bioactivity, and biocompatibility. HAp is brittle with low mechanical strength and poor adhesion to metallic surfaces, which limits its durability and bioactivity. Surface modification techniques have alleviated the imperfections in biomaterials by coating the substrate. Several methods for improving the characteristics of implants, such as physical vapour deposition, the thermal spray method, the sol–gel method, microarc oxidation, and electrochemical deposition methods, have been discussed in this review. These processes provide mechanical strength without sacrificing biocompatibility and may lead to the development of new ideas for future research. This review discusses various selective additives, including carbon allotropes, ceramic materials, metallic materials, and multiple materials, to enhance tribological characteristics, biocompatibility, wear resistance, and mechanical strength. This review focuses on the fabrication of nano-HAps as coatings using selective deposition methods with controlled deposition parameters, paying special attention to recent developments in bone tissue engineering. This report is organized in such a way that it may inspire further research on surface modifications during medical treatment. The present review may help prospective investigators understand the importance of surface modifications for obtaining excellent implantation performance.
In vivo vessel connection of pre-vascularised 3D-bioprinted gingival connective tissue substitutes
Authors: Smirani R , Médina C , Becker J , Déchelette C , Rousseau B , Fricain J-C , Naveau A 
Published: January 2025

Abstract
Producing oral soft tissues using tissue engineering could compensate for the disadvantages of autologous grafts (limited availability and increased patient morbidity) and currently available substitutes (shrinkage). However, there is a lack of in vitro-engineered oral tissues due to the difficulty of obtaining stable pre-vessels that connect to the host and enable graft success. The main objective was to assess the connection of pre-vascularised 3D-bioprinted gingival substitutes to the host vasculature when subcutaneously implanted in immunodeficient mice. This study produced vascularised connective tissue substitutes using extrusion-based 3D-bioprinting of primary human gingival fibroblasts (hGFs) and fluorescent human endothelial cells (RFP-HUVEC) co-cultures. Pre-vascularised (hGF + RFP-HUVEC-CC grids) and control (hGF only -HG grids) grids were bioprinted and pre-cultivated for 14 d to enable pre-vessels formation. In vitro vessel formation follow-up was performed. Eight-week-old female NOG mice were used for in vivo experiments. One grid per mouse was subcutaneously implanted in 20 mice (10HG/10CC). The fluorescent activity of RFP-HUVEC was monitored. Samples were retrieved at 7, 14 and 21 d. Histological, immunohistochemical, and immunofluorescent staining was performed. CC-grids formed efficient and stable pre-vessel networks within 14 d of static pre-culture. HG-grids did not contain any vessel, while CC-grids successfully connected to the host vasculature by presenting erythrocytes within the vessel lumen inside the grids starting day 7. From days 7–21, vessel density was stable. Human pre-vessels were present at 7 d and were progressively replaced by murine ECs. This study showed that primary hGF-HUVEC co-cultures can be successfully 3D-bioprinted within biomimetic hydrogels having a close composition to the gingival connective tissue, and HUVEC organise themselves into pre-vessel networks that connect to the murine vasculature when implanted in vivo. This approach represents a promising strategy to enhance current and future oral soft tissue substitutes for prospective clinical applications.