bluuebunny/crossref_metadata_2025 huggingface dataset:
Turbulence structure of the Rayleigh–Bénard convection using liquid CO2 as working fluid
Authors: Zhao Yifan , Wu Di , Duan Longsheng , Wang Jia , Li Jialiang , Duan Li , Kang Qi
Published: January 2024

We studied the evolution of flow structures and large-scale circulations (LSC) in Rayleigh–Bénard convection (RBC) using liquid carbon dioxide as the working medium. In this experiment, a transparent sapphire pressure vessel with observable internal flow was designed, and different temperature differences were applied between the upper and the lower surfaces of the fluid to obtain different Rayleigh numbers (Ra). We employed proper orthogonal decomposition and reconstruction to extract internal flow structures from the shadowgraphy images. We used optical flow techniques to acquire the velocity field of the flow, and we reconstructed the temperature field inside the supercritical fluid using the relationship between shadowgraphy images and refractive index. It is clearly observed that the RBC begins to produce different flow structures under a small temperature difference of 0.4 °C. As the number of Ra increases, the number and the speed of plumes increase, and the morphology of plumes gradually becomes elongated. When Ra exceeds a certain critical value, an LSC structure appears in the flow field, and the plumes translate laterally with the large-scale circulation, and the disorder of the vortex structure in the central flow region increases significantly. Three typical flow structures were observed: (1) single plume, (2) thermal boundary layer traveling waves, and (3) Rayleigh–Taylor instability waves. We believe that the traveling wave structure is the precursor to the single plume. The temperature field analysis of the three structures was carried out, and the velocity of the typical plume was calculated by the optical flow method. It was found that LSC transitioned from oval to square shape with the increase in Ra, and the internal plume Reynolds number slowly increased with the increase in Ra. By the in-depth study of the thermal turbulence characteristics and the coherent structure evolution law of RBC, this paper provides experimental support for revealing the mechanism of enhanced heat transfer in energy system with a liquid CO2 working fluid.
Propulsive characteristics of single-pulsed jets with tube and orifice openings
Authors: Gao Lei , Wang Xin , Yu Simon C. M.
Published: January 2024

The effects of the nozzle exit geometry on the unsteady propulsive characteristics of single-pulsed jets are studied numerically. For both tube and orifice nozzles, the jet exit configuration is parameterized by the diameter ratio RD, which is defined as the ratio of the nozzle entrance D0 to the jet exit diameters D. It is found that the diameter ratio has significant influence on the propulsive characteristics of the single-pulsed jet during its entire ejection phase. The total impulse production is augmented considerably as the diameter ratio increases until a critical value of RD_cir≈2.0 is approached. The larger impulse production by the orifice nozzles over the tube nozzle stems from the persistent over-pressure contribution at the jet exit due largely to the fact that the flow contraction near the jet exit of the orifice nozzle results in the intensification of the radial velocity gradients and higher local pressure. By using the existing prediction of the contraction coefficient Cc to account for the flow contraction, a theoretical model has been developed with the quasi-one-dimensional flow approximation to predict the pressure thrust at the jet exit during the steady discharging stage, showing good agreement with the present numerical results. Moreover, the pressure force acting on the vertical wall of the orifice nozzle, which is proportional to the wall area, is found to be primarily responsible for the larger transient variations in the jet impulse during the onset and end of the jet ejection phase as the diameter ratio increases.
Computing equilibrium free energies through a nonequilibrium quench
Authors: Liu Kangxin , Rotskoff Grant M. , Vanden-Eijnden Eric , Hocky Glen M.
Published: January 2024

Many methods to accelerate sampling of molecular configurations are based on the idea that temperature can be used to accelerate rare transitions. These methods typically compute equilibrium properties at a target temperature using reweighting or through Monte Carlo exchanges between replicas at higher temperatures. A recent paper [G. M. Rotskoff and E. Vanden-Eijnden, Phys. Rev. Lett. 122, 150602 (2019)] demonstrated that accurate equilibrium densities of states can also be computed through a nonequilibrium “quench” process, where sampling is performed at a higher temperature to encourage rapid mixing and then quenched to lower energy states with dissipative dynamics. Here, we provide an implementation of the quench dynamics in LAMMPS and evaluate a new formulation of nonequilibrium estimators for the computation of partition functions or free energy surfaces (FESs) of molecular systems. We show that the method is exact for a minimal model of N-independent harmonic springs and use these analytical results to develop heuristics for the amount of quenching required to obtain accurate sampling. We then test the quench approach on alanine dipeptide, where we show that it gives an FES that is accurate near the most stable configurations using the quench approach but disagrees with a reference umbrella sampling calculation in high FE regions. We then show that combining quenching with umbrella sampling allows the efficient calculation of the free energy in all regions. Moreover, by using this combined scheme, we obtain the FES across a range of temperatures at no additional cost, making it much more efficient than standard umbrella sampling if this information is required. Finally, we discuss how this approach can be extended to solute tempering and demonstrate that it is highly accurate for the case of solvated alanine dipeptide without any additional modifications.
Orthopedic meta-implants
Authors: Mirzaali Mohammad J. , Zadpoor Amir A.
Published: January 2024

Meta-biomaterials, engineered materials with distinctive combinations of mechanical, physical, and biological properties stemming from their micro-architecture, have emerged as a promising domain within biomedical engineering. Correspondingly, meta-implants, which serve as the device counterparts of meta-biomaterials, offer exceptional functionalities, holding great potential for addressing complex skeletal diseases. This paper presents a comprehensive overview of the various types of meta-implants, including hybrid, shape-morphing, metallic clay, and deployable meta-implants, highlighting their unprecedented properties and recent achievement in the field. This paper also delves into the potential future developments of meta-implants, addressing the exploration of multi-functionalities in meta-biomaterials and their applications in diverse biomedical fields.
Gravity–capillary wave-making resistance on deep water
Authors: Cho Yeunwoo
Published: January 2024

For supercritical cases (forcing speed > the minimum phase speed, 0.23 m/s), the problem of two-dimensional linear, inviscid gravity–capillary waves generated by a moving delta-function type pressure source is well known. Using harmonic functions or Fourier transform, Lamb [Hydrodynamics, 6th ed. (Cambridge University Press, 1993)] and Rayleigh [Proc. London Math. Soc. s1-15(1), 69–78 (1883)] detailed the steady-state full-space wave-profile solution using an artificial viscosity. Whitham [Linear and Nonlinear Waves (Wiley-Interscience, 1974)] presented the same solution for the region that is far-from-the-forcing using a slowly varying exponential function. For the same problem, but, considering not only supercritical but also subcritical cases, and, without using the artificial viscosity, the present work provides a detailed solution procedure to find full-space wave-profile solutions based on Fourier transform where complex integration is needed; different analytical expressions of the same wave profile will be provided depending on different paths. The associated wave-making resistance is shown to be equal to the integral of the product of a moving pressure source, and the resultant wave slope and is calculated in two ways. One is a direct calculation in the physical domain, which requires the wave-profile solution, and the other is an indirect calculation in the wavenumber domain, which does not require the wave-profile solution. For supercritical cases, short and long sinusoidal waves are calculated ahead of and behind the pressure source. The associated wave-making resistance decreases toward a certain constant as the forcing speed increases and the associated required power features a minimum at the forcing speed of 0.3027 m/s. For subcritical cases, a simple symmetric dimple is calculated and the wave-making resistance becomes zero due to its symmetry.
On the steady-state interfacial waves with two-dimensional type-A double exact resonance
Authors: Li Jiyang , Cui Jie , Liu Zeng , Yang Xiaoyan , Zhou Jialuo
Published: January 2024

Steady-state interfacial waves under two-dimensional (2D) type-A exact triad resonance and other related resonances are researched in a two-layer liquid model with a free surface in contact with air. Five groups (groups 1–5) of convergent series solutions are achieved via the homotopy analysis method. It is found that the phenomenon of double exact resonance could exist in periodic interfacial waves if physical parameters correspond to the intersection of two exact resonance curves. The double exact resonance considered here contains a 2D type-A triad resonance and an other resonance. Under the 2D type-A exact triad resonance, the other resonant triad could obviously enlarge or reduce the wave amplitudes and energy proportions of primary and resonant components. Nevertheless, other resonant quartet, quintet, sextet, and septet all produce no influence on interfacial waves when the 2D type-A exact triad resonance occurs. The above-mentioned results indicate that in the neighborhood of the double exact triad resonance, small perturbations of wave vector of a primary component can cause huge changes on wave profiles of free surface and interface, wave amplitude spectrum, and energy distribution of internal waves in real ocean. In addition, the closer the interfacial waves are to the double exact triad resonance, the more possible energy combinations exist in the wave system, and the greater the number of steady-state interfacial wave solutions. All of this should deepen our understanding of nonlinear resonance interactions in short-crested internal waves.
The effects of ventilation conditions on mitigating airborne virus transmission
Authors: Ritos Konstantinos , Drikakis Dimitris , Kokkinakis Ioannis William
Published: January 2024

The effects of ventilation strategies on mitigating airborne virus transmission in a generic indoor space representative of a lobby area or information desk found in a hotel, company, or cruise ship are presented. Multiphase computational fluid dynamics simulations are employed in conjunction with evaporation modeling. Four different ventilation flow rates are examined based on the most updated post-COVID-19 pandemic standards from health organizations and recent findings from research studies. Three air changes per hour provide the best option for minimizing droplet spreading at reasonable energy efficiency. Thus, a higher ventilation rate is not the best solution to avoid spreading airborne diseases. Simultaneous coughing of all occupants revealed that contagious droplets could be trapped in regions of low airflow and on furniture, significantly prolonging their evaporation time. Multiphase flow simulations can help define ventilation standards to reduce droplet spreading and mitigate virus transmission while maintaining adequate ventilation with lower energy consumption. The present work significantly impacts how heat, air-conditioning, and ventilation systems are designed and implemented.
Identification of rheological parameters for shallow water flows of viscoplastic fluids using elevation hydrographs
Authors: Muchiri David K. , Cusack Dale R. , Hewett James N. , Sellier Mathieu , Moyers-Gonzalez Miguel , Monnier Jerome
Published: January 2024

In this paper, rheological parameters, in particular yield stress and consistency index, for viscoplastic fluids are inferred from elevation hydrographs derived from experiments. The direct model consisting of shallow water equations with a Herschel–Bulkley rheology is used to simulate a fluid flowing down an inclined plane and past a cylindrical occlusion. Numerical simulations are validated with experimental and related results from the literature. The aim is to infer the unknown rheological parameters using hydrograph measurements in the contact line region between the fluid and the occlusion. The rheological identification problem is formulated to minimize an objective functional that measures the discrepancy between the elevation hydrographs from the model output and experimental data. The inverse solver is tested on both synthetic and laboratory data. The set of rheological parameters inferred is compared with the values measured on a rheometer for the fluid used in the experiments. Inference of the unknown flow quantities from the wetting free-surface data has direct applications not only in industrial settings, to predict the wetting dynamics, but also in geophysical ones for risk assessments and management plans.
Research on the technology of gob-side entry retaining by pouring support beside the roadway in “three soft” coal seam: A case study
Authors: Fu Jianhua , Chen Deyou , Li Xuelong , Li Honghang , Liu Shumin , Li Changqing , Zhang Junwei
Published: January 2024

This paper's goal is to investigate if a gob-side entry retention technique combined with a surrounding rock support system is feasible in three soft coal seams. Field engineering confirmed the results of numerical simulation tests and similar simulation tests, which were conducted in accordance with the actual geological conditions of Zhaojiazhai Mine. The following conclusions are reached after studying the technology and process parameter of the gob-side entry retaining in three soft coal seams in conjunction with theoretical calculations: the coal seam of Zhaojiazhai Coal Mine's 12 209 working face is a part of the soft coal seam, and its loose circle is approximately 1.8 m. The expansion roadway size is 3.5 m, and the potential loose circle range is 1.32 m, according to the same model and numerical simulation test. The support scheme after the expansion of the road working face is determined to be the “anchor rod + anchor cable + hydraulic lifting shed” support method. Furthermore, this article suggests a building method for the reinforcement and enlargement of gob-side entry retaining in three-soft thick coal seam by theoretical analysis and numerical simulation. Roadway shotcrete, advance grouting, building of a large deformation anchor cable and continuous resistance, single column lifting shed, hydraulic lifting shed, and roadway enlargement in advance are all steps in the procedure. Furthermore, an analysis is conducted on the deformation features of the surrounding rock in gob-side entry retention. The study highlights the significance of actively supporting the surrounding rock, fortifying the roof support, guaranteeing the stiffness compatibility between the shoulder filling body and the surrounding rock on the roof, boosting the wall's strength and stability, and enhancing the roadway's stability.
Swin Transformer based fluid classification using Gram angle field-converted well logging data: A novel approach
Authors: Sun Youzhuang , Zhang Junhua , Zhang Yongan
Published: January 2024

Fluid prediction is important in exploration work, helping to determine the location of exploration targets and the reserve potential of the estimated area. Machine learning methods can better adapt to different data distributions and nonlinear relationships through model training, resulting in better learning of these complex relationships. We first use the Gram angle field (GAF) to convert one-dimensional logging data into two-dimensional images. GAF can better capture the nonlinear structure and patterns in time series data by using trigonometric transformation. After that, we used the Swin Transformer model to classify the converted images. It captures the locality and timing of the image by moving the window. Swin Transformer uses a staged attention mechanism that allows the model to efficiently capture feature information at different scales. This allows the model to capture both local and global information in the image, contributing to a better understanding of the image content. The multi-scale feature capture capability of the Swin Transformer enables it to effectively capture different scales and spatial relationships in fluid prediction tasks. Tested in real data from Tarim Oilfield, the GAF-Swin Transformer model has better performance than other machine learning models. This study provides a new perspective in the field of fluid prediction.
The many faces of stigma after Acquired Brain Injury: a systematic review
Authors: Bracho María-José , Salas Christian
Published: January 2024

Background Stigma after Acquired Brain Injury (ABI) has been described as a significant obstacle for the recovery of survivors. Despite its theoretical and clinical relevance, studies dedicated to stigma after ABI are just starting to emerge. The goal of this systematic review was to integrate the existing scientific evidence and develop a model of stigma after brain injury that can guide interventions at different levels. Method Three electronic databases were employed. A search strategy was adapted for each database. Articles that explored stigma in adult ABI populations were included. All articles used quantitative, qualitative or mixed method designs and were published in English, Spanish or Portuguese. Results A total of 21 articles were selected. They considered three types of stigma after ABI: (1) self-stigma, (2) stigma-by-association and (3) public stigma. It was also found that information can be processed at implicit and explicit levels across all three forms of stigma. Definitions of each type of stigma used with ABIs are provided as well as related concepts and theoretical frameworks employed. Evidence emerging from different forms of stigma after ABI is summarised. Conclusion Research on stigma after ABI is heterogeneous, and existing studies have explored its impact at individual, family and public levels. A model of stigma after ABI should consider all these levels as well as the interactions that can occur between them. Future studies should explore how to incorporate stigma management as part of neuropsychological rehabilitation programs.
Slow closure of Earth’s carbon cycle
Authors: Rothman Daniel H.
Published: January 2024

Carbon near the Earth’s surface cycles between the production and consumption of organic carbon; the former sequesters carbon dioxide while the latter releases it. Microbes attempt to close the loop, but the longer organic matter survives, the slower microbial degradation becomes. This aging effect leaves observable quantitative signatures: Organic matter decays at rates that are inversely proportional to its age, while microbial populations and concentrations of organic carbon in ocean sediments decrease at distinct powers of age. Yet mechanisms that predict this collective organization remain unknown. Here, I show that these and other observations follow from the assumption that the decay of organic matter is limited by progressively rare extreme fluctuations in the energy available to microbes for decomposition. The theory successfully predicts not only observed scaling exponents but also a previously unobserved scaling regime that emerges when microbes subsist on the minimum energy flux required for survival. The resulting picture suggests that the carbon cycle’s age-dependent dynamics are analogous to the slow approach to equilibrium in disordered systems. The impact of these slow dynamics is profound: They preclude complete oxidation of organic carbon in sediments, thereby freeing molecular oxygen to accumulate in the atmosphere.
Trametinib ameliorates aging-associated gut pathology in
Drosophila
females by reducing Pol III activity in intestinal stem cells
Authors: Ureña Enric , Xu Bowen , Regan Jennifer C. , Atilano Magda L. , Minkley Lucy J. , Filer Danny , Lu Yu-Xuan , Bolukbasi Ekin , Khericha Mobina , Alic Nazif , Partridge Linda
Published: January 2024

Pharmacological therapies are promising interventions to slow down aging and reduce multimorbidity in the elderly. Studies in animal models are the first step toward translation of candidate molecules into human therapies, as they aim to elucidate the molecular pathways, cellular mechanisms, and tissue pathologies involved in the anti-aging effects. Trametinib, an allosteric inhibitor of MEK within the Ras/MAPK (Ras/Mitogen-Activated Protein Kinase) pathway and currently used as an anti-cancer treatment, emerged as a geroprotector candidate because it extended lifespan in the fruit fly
Drosophila melanogaster
. Here, we confirm that trametinib consistently and robustly extends female lifespan, and reduces intestinal stem cell (ISC) proliferation, tumor formation, tissue dysplasia, and barrier disruption in guts in aged flies. In contrast, pro-longevity effects of trametinib are weak and inconsistent in males, and it does not influence gut homeostasis. Inhibition of the Ras/MAPK pathway specifically in ISCs is sufficient to partially recapitulate the effects of trametinib. Moreover, in ISCs, trametinib decreases the activity of the RNA polymerase III (Pol III), a conserved enzyme synthesizing transfer RNAs and other short, non-coding RNAs, and whose inhibition also extends lifespan and reduces gut pathology. Finally, we show that the pro-longevity effect of trametinib in ISCs is partially mediated by Maf1, a repressor of Pol III, suggesting a life-limiting Ras/MAPK-Maf1-Pol III axis in these cells. The mechanism of action described in this work paves the way for further studies on the anti-aging effects of trametinib in mammals and shows its potential for clinical application in humans.
A dynamical limit to evolutionary adaptation
Authors: Melissa Matthew J. , Desai Michael M.
Published: January 2024

Natural selection makes evolutionary adaptation possible even if the overwhelming majority of new mutations are deleterious. However, in rapidly evolving populations where numerous linked mutations occur and segregate simultaneously, clonal interference and genetic hitchhiking can limit the efficiency of selection, allowing deleterious mutations to accumulate over time. This can in principle overwhelm the fitness increases provided by beneficial mutations, leading to an overall fitness decline. Here, we analyze the conditions under which evolution will tend to drive populations to higher versus lower fitness. Our analysis focuses on quantifying the boundary between these two regimes, as a function of parameters such as population size, mutation rates, and selection pressures. This boundary represents a state in which adaptation is precisely balanced by Muller’s ratchet, and we show that it can be characterized by rapid molecular evolution without any net fitness change. Finally, we consider the implications of global fitness-mediated epistasis and find that under some circumstances, this can drive populations toward the boundary state, which can thus represent a long-term evolutionary attractor.
Structure of saguaro cactus virus 3′ translational enhancer mimics 5′ cap for eIF4E binding
Authors: Ojha Manju , Vogt Jeff , Das Naba Krishna , Redmond Emily , Singh Karndeep , Banna Hasan Al , Sadat Tasnia , Koirala Deepak
Published: January 2024

The genomes of several plant viruses contain RNA structures at their 3′ ends called cap-independent translation enhancers (CITEs) that bind the host protein factors such as mRNA 5′ cap-binding protein eIF4E for promoting cap-independent genome translation. However, the structural basis of such 5′ cap-binding protein recognition by the uncapped RNA remains largely unknown. Here, we have determined the crystal structure of a 3′ CITE, panicum mosaic virus-like translation enhancer (PTE) from the saguaro cactus virus (SCV), using a Fab crystallization chaperone. The PTE RNA folds into a three-way junction architecture with a pseudoknot between the purine-rich R domain and pyrimidine-rich Y domain, which organizes the overall structure to protrude out a specific guanine nucleotide, G18, from the R domain that comprises a major interaction site for the eIF4E binding. The superimposable crystal structures of the wild-type, G18A, G18C, and G18U mutants suggest that the PTE scaffold is preorganized with the flipped-out G18 ready to dock into the eIF4E 5′ cap-binding pocket. The binding studies with wheat and human eIF4Es using gel electrophoresis and isothermal titration calorimetry, and molecular docking computation for the PTE–eIF4E complex demonstrated that the PTE structure essentially mimics the mRNA 5′ cap for eIF4E binding. Such 5′ cap mimicry by the uncapped and structured viral RNA highlights how viruses can exploit RNA structures to mimic the host protein-binding partners and bypass the canonical mechanisms for their genome translation, providing opportunities for a better understanding of virus-host interactions and non-canonical translation mechanisms found in many pathogenic RNA viruses.
One Medicine vs One Health: Policy disconnect in India
Authors: Yasobant Sandul , Memon Farjana , Kalpana Pachillu , Saxena Deepak
Published: January 2024

One Health is an integrated, unifying approach to balancing and optimizing the health of people, animals, and ecosystems in a sustainable manner. It is a global movement to align our thinking and policy on human, animal, and environmental health, which is critical for effectively combating diseases at the human-animal-environmental interfaces. The Indian government intends to implement the much-needed and globally recognized ‘
One Nation, One Health System’
policy by 2030; however, given the complexity of India’s healthcare system in terms of One Health implementation, it seems to be a long way to go move and accelerate the collaboration among system stakeholders at various levels. Government of India aims to integrate modern and traditional medical systems such as allopathy, ayurveda, and homeopathy in education, medical practice, and research in the larger domain of One Health. Basically, their larger focus is on intra-human health systems integration rather than inter-system integration, which is also not aligned with the principles of One Medicine. Perhaps this could be the foundation for launching the One Health concept, and which will include more relevant stakeholders working at the human-animal-ecosystem interface in the coming years. The current initiative neither fulfils the essential principle of the One Medicine or One Health concept nor will it serve the purpose of the Global One Health joint plan of action. There is an urgent need for broadening the inter-systems stakeholders at all levels and adopting the principles of One Health more holistically in alignment with the global movement.

One Health impact statement

One Health, a comprehensive approach to human, animal, and ecosystem well-being, is well-recognized worldwide. India’s visionary ‘One Nation, One Health System’ policy targets 2030, focusing on integrating diverse medical practices like allopathy, ayurveda, and homeopathy. This marks a foundational stride towards broader engagement across the human-animal-ecosystem interface. Nonetheless, the current proposal has been marked as a shortfall for global One Health principles and objectives. While recognizing the significant room for improvement, this article delicately underscores the need for more comprehensive implementation aligning with One Health principles and considering inter-system harmony beyond the intra-system.
Preparation of robust superhydrophobic surface on PET substrate using Box-Behnken design and facile sanding method with PTFE powder
Authors: Wang Xin , Wang Tao , Sheng Jie , Wang Ziting , Yang Weizhi , Li Meng , Shi Liping
Published: January 2024

Superhydrophobic surfaces have attracted increasing interests due to their excellent features, while achieving facile preparation of superhydrophobic surface with good mechanical stability is still a challenging work. In this paper, we prepared a superhydrophobic surface by sanding polytetrafluoroethylene powder directly onto the surface of a polyethylene terephthalate (PET) film by means of a simple sanding method with sandpaper. The fabrication parameters were firstly optimized using response surface methodology. Surface morphology and chemical composition of the fabricated surface were characterized by field emission scanning electron microscopy, Fourier transform infrared and x-ray photoelectron spectroscopy. The mechanical performance of the superhydrophobic PET surfaces was evaluated by tape peeling test, and potential applications of this surface in self-cleaning and anti-icing were finally carried out. The results showed that the water contact angle up to 153.5° and sliding angle less than ∼3° on PET surface could be prepared under the optimum conditions, and its superhydrophobicity of surfaces was attributed to the synergistically effect of low surface energy and surface roughness. The fabricated superhydrophobic surfaces also exhibited good resistance to abrasion, and they have great potential for application in the fields of self-cleaning and anti-icing.
Effect of high voltage discharge on germination characteristics of vetch seeds at high altitude
Authors: Shi Jinqiang , Jin Fubao , Ma Shangang , Liu Xinhe , Leng Xuejian
Published: January 2024

High-voltage electrostatic fields and low-temperature plasma technology at atmospheric pressure have an important impact on biological growth promotion. Therefore, a multi-needle-column-plate corona plasma generator is proposed in this paper. The negative corona voltammetry characteristics of multi-needle-plate electrodes and multi-needle-column-plate electrodes with different electrode spacing are investigated experimentally, and the electric field distribution of the device is simulated. The device was also applied to vetch seeds at high altitudes to investigate the effect of discharge on germination and root length. The results show that the introduction of column electrodes can effectively improve the electric field distribution of the device so that the device can provide two modes of high voltage electrostatic field and corona plasma field, and ensure the uniform treatment of seeds when the electrode spacing is 3 cm. The treatment of this device accelerates seed germination and promotes root growth, and is more effective under the combined influence of higher electric field strength, ionic wind generated by the discharge, and the active species than a single factor with a lower electric field, as well as shortening the duration of action. The high voltage electrostatic fields at −3 kV, −6 kV, and −9 kV and the corona discharge plasma fields at −12 kV, −15 kV, and −18 kV can effectively accelerate the germination of vetch seeds as well as promote the root growth under the treatment time of 10 min, 20 min, and 30 min. The optimal conditions were −9 kV for 30 min and −15 kV for 10 min, respectively.
Activation of the hair follicle stem cells by low temperature pulsed plasma jet
Authors: Fu Yongqiang , Kong Deqiang , Xu Guowang , Wang Jingze , Wu Yaojiong , Zhang Ruobing
Published: January 2024

The issue of hair loss has become an increasing concern due to growing societal pressures. Currently available hair loss treatments often produce unsatisfactory results, cause significant physical damage, and are costly. Non-thermal atmospheric pressure plasma has been widely used in various biomedical fields, including sterilization, coagulation promotion, and cancer treatment. This paper pioneered the use of a kind of portable pulsed plasma jet power supply in the resting period of mouse hair follicle, and found that plasma jet can effectively shorten the resting period of mouse hair follicle, so that they re-enter the regeneration period and grow hair. Plasma jet provides a new treatment method for hair loss that is cheap, simple, highly effective, has no side effects and has broad application prospects.
Manipulating spin-polarization of Co-doped ZnFe2O4 for photocatalytic TC degradation
Authors: Xie Qijing , Huang Huimin , Zhang Chengliang , Zheng Xiangyang , Shi Haifeng
Published: January 2024

The rapid recombination of photogenerated electrons and holes was an enormous hindrance constraining the photocatalytic efficiency of photocatalysis, which could be effectively solved by inducing electron spin-polarization. Herein, a series of gradient ZnFe2-x
Co
x
O4 (ZFCO-x) magnetic compounds with spin-polarization properties were synthesized by doping Co cation into ZnFe2O4, as well as the diffraction of x-rays characterization confirmed the successful synthesis of the samples. In photodegradation experiments, ZFCO-0.8 manifested improved photocatalytic degradation efficiency in TC removal experiments with visible-light exposure and external magnetic field. Furthermore, the photodegradation experiments exhibited that the degradation efficiency of ZFCO-x could be raised through Co doping and the photocatalytic degradation efficiency was significantly improved under an external magnetic field. The sample exhibiting the most prominent enhancement was ZFCO-x with doping content of x = 0.8, which displayed 48% photocatalytic degradation performance enhancement with a magnetic field. Density functional theory was used to calculate the density of states (DOS) of materials. The calculated DOS indicated that ZFCO-0.8 exhibited the most intense spin-polarization consistent with the results of the experiment. This work is anticipated to deliver an operating method for manipulating spin-polarization in photocatalytic semiconductors to improve photocatalytic degradation efficiency.
Reliable extraction of x-ray refraction and dark-field signals with a large field of view, multi-modal scanning system at spectral energies up to 150 kVp
Authors: Partridge T , Astolfo A , Buchanan I , Kallon G K , Munro P R T , Hagen C K , Endrizzi M , Bate D , Olivo A
Published: January 2024

Multi-modal x-ray scanning allows the simultaneous acquisition of attenuation, refraction and ultra-small angle scattering or dark field images. While many examples of multi-modal x-ray scanning exist in the literature, extension to high x-ray energy, necessary to investigate dense and high-Z materials, still poses challenges. We present the investigation of attenuation, refraction and dark field images taken at 90, 120 and 150 kVp, using a scanning, large field of view multi-modal imaging system. Increases in tube voltage reduce both contrast and signal to noise but still produce satisfactory results suitable for quantitative analysis. On top of benchmarking against phantoms made of known materials, we illustrate this by scanning a 9 V PP3 battery; a highly absorbing sample which causes photon starvation at lower energies.
Small-modulus worms surface defect detection method based on YOLOv7
Authors: Li Yan , Zheng Peng , Yu Menghao , Li Jicun , He Qingze
Published: January 2024

Small-modulus worms are widely used in precision transmission mechanisms. The detection of surface defects on processed small-modulus worms mainly relies on manual inspection. However, this detection method has low detection efficiency and low accuracy. In response to this issue, this paper proposed a surface defect detection method for small-modulus worms based on deep learning. Firstly, based on the geometric features and material properties of small-modulus worms, designed a two-cameras worms image acquisition system to capture small-modulus worm images. And the captured images were annotated and classified to construct a small-modulus worms defect dataset. Secondly, the you only look once version 7 (YOLOv7) network model algorithm was studied and improved. A three-stage image preprocessing algorithm was added to the YOLOV7 model to reduce the interference in distorted areas. Next, Ghost-convolution, batch normalization, Silu activation (CBS) structures were employed to replace some of the conventional CBS structures, reducing computational complexity. And we also added a width–height balance weights and alpha structure to the efficient-IoU (EIOU) loss function. Improve the fitting performance of the model on the bounding box with large aspect ratio. Furthermore, three SimAM attention modules were added to the backbone, increasing the network’s focus on key areas. Finally, experimental validation was conducted, and the results demonstrated that the performance of our proposed method is better than other existing methods. The detection accuracy reached 95.7%, with a map@50 of 94.6%. Overall, the performance met the requirements for worm defect detection.
Fabrication and structural and magnetic properties of spark plasma sintered group-IV diluted magnetic semiconductor Fe-doped SiGe alloys
Authors: Li Jiafei , Zhang Xi , Wang Xiaolian , Wang Xiaofeng , Xiang Gang
Published: January 2024

Fe-doped SiGe bulk alloys are fabricated using non-equilibrium spark plasma sintering (SPS) and their structure and ferromagnetic and magneto-transport properties are investigated. X-ray diffraction and high-resolution transmission electron microscope measurements show that the obtained alloys are composed of SiGe polycrystals. Magnetization measurements reveal that the Fe-doped SiGe alloys exhibit ferromagnetism up to 259 K, and their Curie temperature increases with Fe doping concentration up to 8%. Moreover, transport measurements of the Fe-doped SiGe alloys show typical metal-insulator transition characteristics of doped semiconductors as well as anomalous Hall effect and intriguing positive-to-negative magnetoresistance, indicating that the obtained alloys are diluted magnetic semiconductors (DMSs). Our results provide insight into the SPS-prepared Fe-doped SiGe bulk alloys and may be useful for the design, fabrication, and application of group-IV DMSs.
Giant enhancement of fluorescence resonance energy transfer based on nanoporous gold with small amount of residual silver
Authors: Cui Lianmin , Zhang Ling , Li Zhexiao , Jing Zhiyu , Huang Luyi , Zeng Heping
Published: January 2024

Fluorescence resonance energy transfer (FRET) was found strongly enhanced by plasmon resonance. In this work, Nanoporous Gold with small amount of residual silver was used to form nanoporous gold/organic molecular layer compound with PSS and PAH. The ratio of its specific gold and silver content is achieved by controlling the time of its dealloying. Layered films of polyelectrolyte multilayers were assembled between the donor–acceptor pairs and NPG films to control distance. The maximum of FRET enhancement of 80-fold on the fluorescence intensity between the donor–acceptor pairs (CFP-YFP) is observed at a distance of ∼10.5 nm from the NPG film. This Nanoporous Gold with small amount of residual silver not only enhanced FRET 4-fold more than nanoporous gold of only gold content almost, but also effectively realized the regulation of FRET enhancement. The ability to precisely measure and regulate the enhancement of FRET enables the rational selection of plasmonic nanotransducer dimensions for the particular biosensing application.
A cascade transformer-based model for 3D dose distribution prediction in head and neck cancer radiotherapy
Authors: Gheshlaghi Tara , Nabavi Shahabedin , Shirzadikia Samireh , Moghaddam Mohsen Ebrahimi , Rostampour Nima
Published: January 2024

Objective. Radiation therapy is one of the primary methods used to treat cancer in the clinic. Its goal is to deliver a precise dose to the planning target volume while protecting the surrounding organs at risk (OARs). However, the traditional workflow used by dosimetrists to plan the treatment is time-consuming and subjective, requiring iterative adjustments based on their experience. Deep learning methods can be used to predict dose distribution maps to address these limitations. Approach. The study proposes a cascade model for OARs segmentation and dose distribution prediction. An encoder–decoder network has been developed for the segmentation task, in which the encoder consists of transformer blocks, and the decoder uses multi-scale convolutional blocks. Another cascade encoder–decoder network has been proposed for dose distribution prediction using a pyramid architecture. The proposed model has been evaluated using an in-house head and neck cancer dataset of 96 patients and OpenKBP, a public head and neck cancer dataset of 340 patients. Main results. The segmentation subnet achieved 0.79 and 2.71 for Dice and HD95 scores, respectively. This subnet outperformed the existing baselines. The dose distribution prediction subnet outperformed the winner of the OpenKBP2020 competition with 2.77 and 1.79 for dose and dose–volume histogram scores, respectively. Besides, the end-to-end model, including both subnets simultaneously, outperformed the related studies. Significance. The predicted dose maps showed good coincidence with ground-truth, with a superiority after linking with the auxiliary segmentation task. The proposed model outperformed state-of-the-art methods, especially in regions with low prescribed doses. The codes are available at https://github.com/GhTara/Dose_Prediction.
Pencil beam kernel-based dose calculations on CT data for a mixed neutron-gamma fission field applying tissue correction factors
Authors: Sommer Lucas B , Kampfer Severin , Chemnitz Tobias , Breitkreutz Harald , Combs Stephanie E , Wilkens Jan J
Published: January 2024

Objective. For fast neutron therapy with mixed neutron and gamma radiation at the fission neutron therapy facility MEDAPP at the research reactor FRM II in Garching, no clinical dose calculation software was available in the past. Here, we present a customized solution for research purposes to overcome this lack of three-dimensional dose calculation. Approach. The applied dose calculation method is based on two sets of decomposed pencil beam kernels for neutron and gamma radiation. The decomposition was performed using measured output factors and simulated depth dose curves and beam profiles in water as reference medium. While measurements were performed by applying the two-chamber dosimetry method, simulated data was generated using the Monte Carlo code MCNP. For the calculation of neutron dose deposition on CT data, tissue-specific correction factors were generated for soft tissue, bone, and lung tissue for the MEDAPP neutron spectrum. The pencil beam calculations were evaluated with reference to Monte Carlo calculations regarding accuracy and time efficiency. Main results. In water, dose distributions calculated using the pencil beam approach reproduced the input from Monte Carlo simulations. For heterogeneous media, an assessment of the tissue-specific correction factors with reference to Monte Carlo simulations for different tissue configurations showed promising results. Especially for scenarios where no lung tissue is present, the dose calculation could be highly improved by the applied correction method. Significance. With the presented approach, time-efficient dose calculations on CT data and treatment plan evaluations for research purposes are now available for MEDAPP.
Modeling of high-field-side high-density regime in the Globus-M2 tokamak
Authors: Dolgova K , Vekshina E , Rozhansky V
Published: January 2024

Formation of a high-field-side high-density (HFSHD) regime and the role of the high-field-side (HFS) poloidal electric field in the scrape-off layer of the spherical tokamak Globus-M2 are analyzed using SOLPS-ITER edge plasma simulations. The dependence of the HFS poloidal electric field sign and, consequently, radial drift fluxes on the discharge density is discussed. It is demonstrated that the HFS poloidal electric field is the key element in the formation of a HFSHD regime in the Globus-M2 tokamak as in ASDEX Upgrade. It is demonstrated that the physics of HFSHD formation in a small spherical tokamak is similar to that suggested by Kaveeva et al (2009 36th EPS Conf. on Plasma Physics) and is in line with experimental observations and modeling, performed later on ASDEX Upgrade.
High-velocity micromorphological observation and simulation of magnetorheological gel using programmable magneto-controlled microfluidics system and micro-tube dynamic models
Authors: Yu Miao , Gan Ruyi , Fu Jie , Qi Song , Han Jinyu , Li Haitao
Published: January 2024

Application of magnetorheological gel (MRG) is a promising tool for high performance mitigation due to its outstanding energy absorption and dissipation properties. However, the lack of recognition on micromorphological variation for MRG and its magneto-mechanical coupling mechanism limits its extensive application. Herein, combined with the magnetic sensitivity nature of MRG, we develop a magneto-controlled microfluidic system for flexible simulation toward ms-level impact conditions. Microstructural changes of MRG, prepared with solid–liquid composite method, are characterized from variable magnet-field setups and gradual velocities. Experiments reveal that the increasing magnetic flux density can effectively enhance the stability of chains in as-fabricated MRG, while the chains can support excessive velocities up to 4.5 m s−1 before breaking. Meanwhile, under the preset velocity range, the maximum change rates of the average and standard deviation for inclinations are 183.71% and 40.06%, respectively. Successively, an experiment-conducted microdynamic model is developed for numerical simulation of the MRG mechanical behaviors. During that, high-velocity MRG behaviors are explored with a tubular rather than regular flat-structure boundary condition setups, to pursue more trustable results. Simulation readouts meet nicely with those from experiments in revealing the magneto-mechanical coupling mechanism of MRG under multiphysics. The interaction between magnetic force, repulsive force and viscous resistance is mainly illustrated. This work provides a reliable observation basis for micromorphological variation of MRG, also suggests a new method for the mechanism of magneto-mechanical coupling at extreme velocities.
Optimized design for absorption metasurface based on autoencoder (AE) and BiLSTM-Attention-FCN-Net
Authors: Zhu Lei , Du Wenchen , Dong Liang , Wei Jinxu
Published: January 2024

In order to speed up the process of optimizing design of metasurface absorbers, an improved design model for metasurface absorbers based on autoencoder (AE) and BiLSTM-Attention-FCN-Net (including bidirectional long-short-term memory network, attention mechanism, and fully-connection layer network) is proposed. The metasurface structural parameters can be input into the forward prediction network to predict the corresponding absorption spectra. Meantime, the metasurface structural parameters can be obtained by inputting the absorption spectra into the inverse prediction network. Specially, in the inverse prediction network, the bidirectional long-short-term memory (BiLSTM) network can effectively capture the context relationship between absorption spectral sequence data, and the attention mechanism can enhance the BiLSTM output sequence features, which highlight the critical feature information. After the training, the mean square error (MSE) value on the validation set of the reverse prediction network converges to 0.0046, R2 reaches 0.975, and our network can accurately predict the metasurface structure parameters within 1.5 s with a maximum error of 0.03 mm. Moreover, this model can achieve the optimal design of multi-band metasurface absorbers, including the single-band, dual-band, and three-band absorptions. The proposed method can also be extended to other types of metasurface optimization design.