bluuebunny/crossref_metadata_2025 huggingface dataset:
Impact of a new dedicated sheath device for tissue sampling of biliary stricture on pathological diagnostic yield: Retrospective study
Authors: Niiya Fumitaka , Ishiwatari Hirotoshi , Sasaki Keiko , Ishikawa Kazuma , Sato Junya , Kishida Yoshihiro , Imai Kenichiro , Hotta Kinichi , Ono Hiroyuki
Published: March 2024

Background and study aims Endoscopic transpapillary biliary forceps biopsy (TBFB) is a common method for obtaining specimens from biliary lesions. Its diagnostic yield is unsatisfactory; to overcome this disadvantage, a dedicated sheath has been developed. This study aimed to evaluate the outcomes of conventional TBFB and TBFB with a novel sheath device.

Patients and methods Consecutive patients who underwent TBFB between January 2020 and December 2021 were retrospectively evaluated. The rate of obtaining adequate samples, failed attempts at forceps insertion into the bile duct, and sensitivity were compared between the two groups.

Results Ninety-two patients who underwent 115 endoscopic retrograde cholangiopancreatographies (76 in the conventional group vs. 39 in the dedicated sheath group) were included. The rates of obtaining adequate samples, failed attempts of the forceps into the bile duct, and sensitivity were 72.4% vs. 89.7% (P = 0.03), 28.3% vs. 0% (P < 0.01), and 66.7% vs. 88.9% (P = 0.02), respectively.

Conclusions TBFB with the novel sheath device contributed to improved sensitivity for diagnosis of biliary stricture without insertion of forceps outside the bile duct.
Efficient and Scalable Enantioselective Synthesis of a Key Intermediate for Rimegepant: An Oral CGRP Receptor Antagonist
Authors: Luo Zhonghua , Sun Guodong , Wang Guowei , Zhang Xin , Zhang Yang , Zhang Ji
Published: March 2024

Rimegepant is a calcitonin gene-related peptide antagonist used for acute treatment and prevention of migraine. We herein attempt to explore an efficient and practiced method for scale-up, regio- and enantioselective synthesis of (R)-9-hydroxy-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridin-5-one (1), a key intermediate of rimegepant. In this work, a Ru-catalyzed asymmetric transfer hydrogenation (ATH) reaction was a key step. The optimization of the reaction conditions involved exploring the reaction parameters including catalysts, bases, and solvents. The results suggested that the Ru-catalyzed ATH process using formic acid as the hydrogen donor could be operated under mild conditions at a low catalyst loading (0.5 mol%), affording a high yield (92.1% yield with 99.8% purity) and gratifying enantioselectivity (99.9% ee) of the target product (1). This work first reported the Ru-catalyzed ATH process in the synthesis of key intermediates of rimegepant. The optimized ATH process was easy to implement and cost-effective, making it particularly suitable for manufacturing scale production.
Intermediary Perception of Narcissistic and Humble CEO Traits
Authors: Brunzel Johannes
Published: March 2024

The media plays a key role in bridging information asymmetries between parties such as CEOs and third-party observers. However, current research suggest that the media is not just a carrier of information but can actively shape the impression of the audience. An open question remains, hence, whether media reporting is affected by certain CEO traits such as narcissism or humility, two key constructs in the literature. For instance, narcissistic CEOs’ belief in their own superiority may spillover to the media, thereby distorting the function as information carrier and favoring directly or indirectly certain CEO traits. Therefore, by drawing on the differential effects that narcissism and humility can have on the impression of an audience, the study employs a computer-aided content analysis of factual narcissistic and humble CEOs, identified via a video metric approach, and their evaluation through three key journalistic intermediaries (New York Times, Washington Post, and Financial Times). The quantitative data suggest that actual CEO narcissism is related negatively to external performance evaluations of CEOs in subsequent years. In addition, the data suggest that narcissism as well as humility scores increase the emotional tone employed depending on the journalistic orientation of the media outlet. Humble CEOs receive on average more media attention than narcissistic CEOs yet this result is insignificant, providing limited evidence for a systematic (i.e., number of articles) bias across and within journalistic outlets towards either narcissistic or humble CEOs. This suggests that widely considered “quality” media outlets resist to portray CEO traits in an overly positive/negative light.
Adsorption of cadmium selenide clusters: A novel approach to enhance solar energy conversion using armchair graphene nanoribbons
Authors: Tran Thi Nhan , Nguyen Truc Anh , Anh Duy Nguyen Vo , Nguyen Truong Long , Dinh Van An , Schall Peter , Dang Minh Triet
Published: March 2024

Tailoring the electronic, optical, and transport properties of low-dimensional semiconductor materials is essential to improve the light-conversion efficiency of thin-film solar cell materials. Here, using first-principles calculations and non-equilibrium Green functions, we investigate the enhancement of optoelectronic and transport properties of armchair graphene nanoribbons (AGNRs) upon adsorption of cadmium selenide clusters. Upon adsorption of a CdSe diatomic molecule on an AGNR, the most energetically favorable configuration is the cadmium end sitting on top of a carbon atom. The corresponding electronic bandgap reduces ∼5 times with respect to that of the pristine system, thanks to the formation of a polaron state formed by the p-orbital of the selenide atom. Upon adsorption of CdSe cyclohexane molecules, the bandgap of this system slightly shrinks by 0.121 eV with respect to the pristine system. The charge accumulation induced by these clusters significantly enhances the absorption coefficient of the adsorbed systems, resulting in a red shift of the optical spectra toward the infrared region. More interestingly, by solving the Bethe–Salpeter equations with the Tamm–Dancoff approximation, we provide a direct link between the first-principles optical prediction and experimental observations. In addition, the electron transfer from these molecules to the hosted systems increases the transmission spectra in the vicinity of the Fermi level, leading to a remarkable electronic current passing through these scattering regions. These results highlight the role of cadmium selenide clusters in enhancing the light-to-energy conversion efficiency of next-generation solar cell devices.
Random forests for detecting weak signals and extracting physical information: A case study of magnetic navigation
Authors: Moradi Mohammadamin , Zhai Zheng-Meng , Nielsen Aaron , Lai Ying-Cheng
Published: March 2024

It has been recently demonstrated that two machine-learning architectures, reservoir computing and time-delayed feed-forward neural networks, can be exploited for detecting the Earth’s anomaly magnetic field immersed in overwhelming complex signals for magnetic navigation in a GPS-denied environment. The accuracy of the detected anomaly field corresponds to a positioning accuracy in the range of 10–40 m. To increase the accuracy and reduce the uncertainty of weak signal detection as well as to directly obtain the position information, we exploit the machine-learning model of random forests that combines the output of multiple decision trees to give optimal values of the physical quantities of interest. In particular, from time-series data gathered from the cockpit of a flying airplane during various maneuvering stages, where strong background complex signals are caused by other elements of the Earth’s magnetic field and the fields produced by the electronic systems in the cockpit, we demonstrate that the random-forest algorithm performs remarkably well in detecting the weak anomaly field and in filtering the position of the aircraft. With the aid of the conventional inertial navigation system, the positioning error can be reduced to less than 10 m. We also find that, contrary to the conventional wisdom, the classic Tolles–Lawson model for calibrating and removing the magnetic field generated by the body of the aircraft is not necessary and may even be detrimental for the success of the random-forest method.
Design and simulation of measuring model for horizontal flight distance of projectile based on discrete acceleration
Authors: Shi Yonglei , Zhang Tiebi , Jia Guangfei , Zhao Yuejing , Xue Zhanpu , Qin Zhiying
Published: March 2024

The ability of the projectile to strike accurately in the air depends on the accurate measurement of its flight distance. Due to the influence of the external environment, it is very difficult to measure the distance of high-speed projectiles in real time with ranging equipment such as radar and laser. Based on this, a real-time measurement model of the horizontal flight distance of the projectile was designed, which combines trajectory equation and discrete acceleration. First, the angle of inclination of the projectile at each position was calculated according to the six-degree-of-freedom rigid outer trajectory model. Then, two kinds of distance measurement models based on discrete acceleration integration were introduced, and the accuracy simulation was carried out. Simulation results show that the Simpson integral method is more accurate. The flight arc length of the projectile was calculated by the Simpson integral method. Finally, the horizontal flight distance of the projectile was obtained by combining the flight arc length and inclination angle of the projectile. Finally, the flight distance measurement model was simulated, and the simulation results show that the model has high accuracy. The simulation results show that the horizontal flight distance of the projectile can be measured by the trajectory equation and discrete acceleration according to the set conditions. This method can be used to measure the distance of the projectile by carrying the sensor and is less affected by the external environment. It can provide a theoretical basis and reference for the measurement of the horizontal distance of the projectile.
Experimental study on mechanical properties of FDM 3D printed polylactic acid fabricated parts using response surface methodology
Authors: Patil Shashwath , Sathish T. , Makki Emad , Giri Jayant
Published: March 2024

The purpose of this study is to examine the mechanical properties of components produced through the Response Surface Methodology for polylactic acid, utilizing the Fused Deposition Modeling 3D printing technique. Polylactic acid is a commonly employed biodegradable polymer, making it a desirable substance for diverse applications. This study involves carrying out experiments to vary process printing parameters like layer height or thickness, part orientation, and infill density. The values of these parameters were obtained using a Response Surface Methodology Box–Behnken experimental design. The mechanical performance of the 3D Printed polylactic acid fabricated was assessed by evaluating their flexural and tensile strength. The test samples for measuring tensile and flexural strength are fabricated according to American Society for Testing and Material standards. The findings suggest that higher strength is achieved when using increased layer height and infill levels. The experimental results indicated that specimens with a filling ratio of 80% exhibited greater tensile strength, while the flexural strength of samples with 50% infill was observed to be higher. Regression analyses and multi-optimization techniques were employed to predict the experimental results. This study provides valuable insights that can significantly impact various industries. Our research on the complex interactions between process variables and mechanical properties has major implications for improving high-strength component manufacturing. As demand for dependable and efficient 3D-printed materials rises, our discoveries improve material design and manufacturing methods, making a significant contribution to the field.
Effectiveness of Canna indica leaves and stalk biochar in the treatment of textile effluent
Authors: Shah Vishalkumar , Gajbhiye Pratima , Mehta Jigesh , Tudu Balraj , Sillanpaa Mika , Siddiqui Md Irfanul Haque , Kumar Abhinav , Shah Mohd Asif
Published: March 2024

Textile effluents often include water polluted with heavy metals, organic and inorganic contaminants, and different colors. It is not practical to remove these pollutants from the water. A variety of methods, including ozone, adsorption, membrane separation, biosorption, biodegradation, electrochemical degradation, and UV radiation, might be used in the water treatment procedure. Biochar made from Canna indica leaves and stems was used to remediate textile industry wastewater, which included color and chemical oxygen demand (COD). By using an absorption technique, the biochar was created by roasting the material at 500 °C, which removed the color and COD from the wastewater. The batches were subjected to many variations in temperature, concentration, and dose of biochar throughout the testing phase. Canna leaves have been shown to be effective in reducing COD at doses between one and 1.5 gm. COD levels were reduced by 83%, and color was reduced by around 94%. On the other hand, while keeping a constant dose, it was shown that canna stalks showed noteworthy effectiveness in lowering COD levels, with a range of 33%–48%. When it comes to eliminating color and COD, the leaves of the canna plant show more specificity than those of other plant species. The Jovanovich isotherm showed a good association with the biochar made from Canna indica leaves, according to the examination of the isotherm computation.
Mg activation anneal of the p-GaN body in trench gate MOSFETs and its effect on channel mobility and threshold voltage stability
Authors: Filho Walter Gonçalez , Borga Matteo , Geens Karen , Khan Md Arif , Cingu Deepthi , Chatterjee Urmimala , Vohra Anurag , Decoutere Stefaan , Bakeroot Benoit
Published: March 2024

This work addresses the impact of the Mg activation anneal step and the resulting acceptor concentration on the channel mobility and VT stability of vertical MOSFETs. Increasing the annealing time with N2 only ambient and the annealing temperature with O2 in the ambient is shown to be effective in increasing the channel acceptor concentration. When the effective acceptor concentration is increased, the mobility is degraded due to a transition in the main scattering mechanism from Coulomb to surface roughness scattering. Degradation of the on-state current and maximum transconductance at high operating temperatures was linked to bulk mobility degradation of the drift layer due to lattice scattering. The two Mg activation annealing conditions considered here show different trends with regard to the threshold voltage stability, while N2 only ambient did not impact this parameter, including O2 increased threshold voltage instability. It is shown that increasing the Mg chemical concentration in the p-GaN layer degrades channel mobility and threshold voltage stability, irrespectively of the effective acceptor concentration, providing evidence for degradation of the channel/dielectric interface characteristics with higher Mg chemical concentration. This study shows that it is possible to achieve very low threshold voltage hysteresis and high channel mobility by reducing the Mg chemical concentration while maintaining high effective acceptor concentration. These results provide key insights for the development of vertical GaN FETs.
An improved proportional topology optimization method combining a polarized material interpolation scheme and Heaviside threshold function
Authors: Rao Xiong , Cheng Wenming , Du Run
Published: March 2024

An improved proportional topology optimization (IPTO) method is proposed in this work. The main improvement of this method is that the conventional solid isotropic material with penalization (SIMP)-based material interpolation scheme is replaced by a polarized material interpolation scheme, and the Heaviside threshold function is adopted based on the original proportional topology optimization (PTO) method. By using this approach, the minimum compliance problem can be solved without requiring the numerical derivation of the sensitivity function. To verify the feasibility and effectiveness of the proposed method, two-dimensional (2D) and three-dimensional (3D) cantilevers and L-bracket beams are used as examples. The 2D results obtained by the IPTO method are compared with those obtained by the PTO and SIMP methods. Numerical examples demonstrate that IPTO can acquire better objective function values and more ideal topology structures compared to PTO and SIMP. Furthermore, IPTO offers significant advantages over PTO and SIMP in terms of convergence speed and the ability to suppress intermediate density elements. Additionally, this method enables topology optimization design under multiple working conditions. Therefore, it provides an effective approach for structural topology optimization in research and engineering applications. With appropriate adjustment, this method can also be applied to composite material design and heat conduction design.
Analysis of guidance and levitation forces between HTS magnets and conductive tubes for Hyperloop
Authors: Choi Suyong , Lee Changyoung , Lim Jungyoul
Published: March 2024

High-temperature superconducting (HTS) magnets combined with linear synchronous motors and electrodynamic suspension (EDS) are considered as one of the most suitable technologies for Hyperloop. However, HTS magnets on pods generate strong magnetic fields, inducing eddy currents on conductive tubes when pods undergo movement through conductive tubes. The induced eddy currents affect HTS magnets, leading to electromagnetic (EM) drag, guidance, and levitation forces on the pods, thus reducing the propulsion efficiency and dynamic stability of pods. This study continues the existing research on EM drag forces between HTS magnet and tube for Hyperloop by comprehensively analyzing the EM guidance and levitation forces between HTS magnets and conductive tubes. Importantly, the full-scale 3D finite element analysis (FEA) simulations show that different steel tubes, such as AISI 1010 and high-manganese (Hi-Mn) steels, should be adopted, depending on the operating velocities, v, to avoid attractive forces in the guidance direction decreasing horizontal stiffnesses, For example, Hi-Mn tubes generating repulsive guidance forces are adopted when v is below 300 km/h while AISI 1010 tubes are used when v is over 300 km/h to minimize the construction cost of vacuum tubes to guarantee the increase in kx. For the proposed concept, the effect of the different tube connections on guidance and levitation forces is confirmed by the full-scale 3D FEA simulation. Moreover, levitation forces generated between HTS magnets and conductive tubes are nearly 0.5% of the EDS forces of pods, i.e., 200 kN over v of 150 km/h in the levitation direction. Therefore, the effect on vertical stiffnesses, ky, might be limited. In the end, to validate the proposed tube connections, the effect of the two different tube connections on guidance and levitation forces is confirmed by the full-scale 3D FEA simulation, and it was found that the sudden change in the guidance and levitation forces could be low enough to be neglected in the acceleration (from Hi-Mn to AISI 1010 steel tubes) and deceleration (from AISI 1010 to Hi-Mn steel tubes) regions.
Physics based optical modeling of iron disulfide thin films
Authors: Zaka Awais , Abdul Hadi Sabina , Pal Pratibha , Kumar Dayanand , El-Atab Nazek , Alhassan Saeed , Nayfeh Ammar
Published: March 2024

In this work, physics based optical modeling is carried out using iron disulfide thin films deposited by using a plasma-assisted, radio frequency-powered technique. Iron disulfide is a transition metal dichalcogenide material, exhibiting a variety of unique and excellent characteristics. Various characterization techniques are employed to examine the growth rate, film thickness, and behavior of as-grown iron disulfide thin films. Furthermore, the physics based optical modeling was performed using a combination of experimental techniques and computer modeling approaches. The analyzed thin films exhibit a bandgap of around 1.16 eV. The theoretically calculated values of absorbance, transmission, and reflectance show a good match with the experimental measurements. Moreover, a physics based optical model is developed based on the experimental data and is used to calculate the external quantum efficiency and the optically generated current density of the iron disulfide films to provide insight into its use as an absorber layer.
Radiation pressure induced oscillations of an optically levitating mirror
Authors: Jha Satyam Shekhar , Carmon Tal , Cheng Fan , Deych Lev
Published: March 2024

Optical Fabry–Perot cavity with a movable mirror is a paradigmatic optomechanical system. While usually the mirror is supported by a mechanical spring, it has been shown that it is possible to keep one of the mirrors in a stable equilibrium purely by optical levitation without any mechanical support. In this work, we expand previous studies of the nonlinear dynamics of such a system by demonstrating a possibility for mechanical parametric instability and the emergence of the “phonon laser” phenomenon.
Conharmonically flat and conharmonically symmetric warped product manifolds
Authors: Syied Abdallah Abdelhameed , Chand De Uday , Turki Nasser Bin
Published: March 2024

This article presents characterizations of warped product manifolds based on the flatness and symmetry of the conharmonic curvature tensor. It is proved that when a warped product manifold is conharmonically flat, both the base and fiber manifolds exhibit constant sectional curvatures. In addition, the specific forms of the conharmonic curvature tensor are derived for both the base and fiber manifolds. It is demonstrated that in a conharmonically symmetric warped product manifold, the fiber manifold has a constant sectional curvature, while the base manifold is both Cartan-symmetric and conharmonically symmetric. In this scenario, the form of the conharmonic curvature tensor on the fiber manifold is determined. We characterize the generalized Robertson–Walker (GRW) space-time through the flatness and the symmetry of the conharmonic curvature tensor. It is shown that a conharmonically flat (symmetric) GRW space-time is a perfect fluid. Finally, a conharmonically flat standard static space-time is investigated.
Optimizing the performance of the thermal transistor based on negative differential thermal resistance
Authors: Wu Tianheng , Yang Yu , Wang Tingting , Li Xiaozhe , Zhang Lifa
Published: March 2024

Thermal transistors have significant potential in thermal management due to their ability to precisely control the heat fluxes. However, the current design has a limited working temperature range and cannot meet the demand for heat control. In this work, we optimize the performance of a thermal transistor based on negative differential thermal resistance using a modified Lorentz gas model, focusing on the effects of gate control and thermal conductance. We find that the control of the gate has an asymmetrical property, and the sufficient control can expand the working region by more than 1.5 times. In addition, the switching and amplifying functions of the thermal transistor are inversely dependent on thermal conductance, and an increase in thermal conductance can lead to a 27 times amplification in heat flux. The synergistic regulation of the two factors results in the optimal performance of a 44% working region and a 33 times amplification in heat flux. These findings refresh the understanding of the performance limits of thermal transistors, promoting efficient thermal management and addressing heat dissipation issues.
Strength degradation of GFRP cross-ply laminates in hydrothermal conditions
Authors: Cheng Wen , Cao Yan
Published: March 2024

The changes in mechanical properties of glass fiber reinforced plastic cross-ply laminates as a result of hydrothermal aging were studied theoretically. The composite specimens have been immersed in distilled water at 25, 40, and 70 °C for 60 days for aging testing. Based on Fick’s law and the Arrhenius theorem, the moisture absorption data under different environments was analyzed, and the method for determining the diffusivity and the equilibrium moisture content was obtained. The relationship model between the moisture absorption behavior of the composite material and the ambient temperature was proposed and verified by finite element analysis. The mechanical behavior of the composites was studied by tensile, compression, and three-point bending tests. Under the condition of ultimate moisture absorption, the tensile, compressive, and bending strengths of the composite decreased by 31.663%, 12.948%, and 26.985%, respectively. A variety of empirical models were used for data analysis, which confirmed the strong correlation between strength degradation and moisture absorption of composite cross-ply laminates. The scanning electron microscope observation results of different moisture absorption levels showed that matrix cracking and fiber/matrix interface debonding caused by moisture absorption are the fundamental reasons for the strength degradation of the composites.
A re-examination of claims of aminoferrocene–graphene-based molecular magnets
Authors: Athavan Gayathri , Coudert François-Xavier , Bedford Robin B.
Published: March 2024

A recent investigation claimed that graphene oxide (GO) modified by aminoferrocene gave a material that showed room temperature colossal superparamagnetic behavior. The first step in the reported synthesis of aminoferrocene was the direct nitration of ferrocene. We show here, in accord with previous precedents, that the direct nitration of ferrocene by the nitronium ion does not occur under the conditions reported and, therefore, the material described previously cannot be based on aminoferrocene. Computational investigations undertaken herein show that the model used to account for the magnetic properties of the material results from an artifact of the GO model employed.
Sound field separation based on dictionary learning and sparse sampling
Authors: Liu Yuan , Li Yongchang , Zhao Jinyu
Published: March 2024

Sound field separation techniques are an advancing tool for extracting a target sound field from a mixed sound field. However, the methods bear a high measurement cost due to the restriction of the sampling theorem. In this study, a sound field separation method based on sparse sampling is established. The method initially utilizes dictionary learning to generate a sparse basis of the sound field. Then, a mixed sound field can be precisely recovered from sparse sampling of sound pressure and the target sound field can be extracted based on the recovered sound field by means of the theory of equivalent source method. The method is validated by numerical simulations. Compared to sound field separation based on the equivalent source method, the proposed method has advantage in terms of both the accuracy and the stability for sparse sampling.
A pilot study to encode calls from the northern yellow-bellied glider
Authors: Heise-Pavlov Sigrid , Prokop Colby , Goss Louisa
Published: March 2024

As one of the most vocal marsupials in Australia, conservation of the yellow-bellied glider (Petaurus australis brevirostrum) (YBG) could benefit from the extraction of more information from their calls during acoustic monitoring. This pilot study investigates the variability of syllable components of full calls and identifies acoustic parameters that underlie variability in recorded calls from wild YBGs in North Queensland, Australia. Full calls with three syllables and with two syllables were distinguished. Using batch correlations and principal component analyses (PCAs), it was found that syllable two and syllable three show high variability in their duration and that maximum frequency is the strongest contributing sound parameter to the observed variability. However, because data collection was done in wild populations, the identity of call emitters remained unknown during call analyses, demanding further studies. Further subdivision of calls, and investigation into further acoustic parameters, could aid in decoding sexual, seasonal and individual-based meanings of calls.
Demographics and reproductive characteristics of threatened Malabar pufferfish (Carinotetraodon travancoricus) from Western Ghats hotspot, India
Authors: Renjithkumar Chelapurath Radhakrishnan , Roshni Kuttanelloor
Published: March 2024

Context Carinotetraodon travancoricus is a threatened ornamental aquarium fish endemic to Western Ghats (WG) biodiversity hotspot of India and indiscriminate collection of this species resulted in a severe population decline. Aims To understand the impacts of wild collection of C. travancoricus for aquarium-fish trade, information on their population status and reproductive characteristics is required. Methods Specimens for the present study were collected from the Chalakudy River of WG and growth, mortality, exploitation and reproductive characteristics of C. travancoricus were investigated. Key results The natural mortality of the species was higher than the fishing mortality. The peak spawning period of the species was from May to September. Length at first maturity (L50) for males and females was estimated to be 18.4 and 18.1 mm respectively. Conclusions The stock of C. travancoricus in the Chalakudy River may be in near full exploitation under current harvesting strategy. The lower value of length of first capture than size at first maturity indicated that C. travancoricus is likely to be captured before it matures and breeds, subsequently contributing to declining recruitment. Implications A combination of different strategies (closed fishing seasons, mesh-size regulation and no-fishing areas) will improve sustainable management and conservation of species.
Polarized localization of kinesin-1 and RIC-7 drives axonal mitochondria anterograde transport
Authors: Wu Youjun , Ding Chen , Sharif Behrang , Weinreb Alexis , Swaim Grace , Hao Hongyan , Yogev Shaul , Watanabe Shigeki , Hammarlund Marc
Published: March 2024

Mitochondria transport is crucial for axonal mitochondria distribution and is mediated by kinesin-1-based anterograde and dynein-based retrograde motor complexes. While Miro and Milton/TRAK were identified as key adaptors between mitochondria and kinesin-1, recent studies suggest the presence of additional mechanisms. In C. elegans, ric-7 is the only single gene described so far, other than kinesin-1, that is absolutely required for axonal mitochondria localization. Using CRISPR engineering in C. elegans, we find that Miro is important but is not essential for anterograde traffic, whereas it is required for retrograde traffic. Both the endogenous RIC-7 and kinesin-1 act at the leading end to transport mitochondria anterogradely. RIC-7 binding to mitochondria requires its N-terminal domain and partially relies on MIRO-1, whereas RIC-7 accumulation at the leading end depends on its disordered region, kinesin-1, and metaxin2. We conclude that transport complexes containing kinesin-1 and RIC-7 polarize at the leading edge of mitochondria and are required for anterograde axonal transport in C. elegans.
p24–Tango1 interactions ensure ER–Golgi interface stability and efficient transport
Authors: Yang Ke , Feng Zhi , Pastor-Pareja José Carlos
Published: March 2024

The eukaryotic p24 family, consisting of α-, β-, γ- and δ-p24 subfamilies, has long been known to be involved in regulating secretion. Despite increasing interest in these proteins, fundamental questions remain about their role. Here, we systematically investigated Drosophila p24 proteins. We discovered that members of all four p24 subfamilies are required for general secretion and that their localizations between ER exit site (ERES) and Golgi are interdependent in an α→βδ→γ sequence. We also found that localization of p24 proteins and ERES determinant Tango1 requires interaction through their respective GOLD and SH3 lumenal domains, with Tango1 loss sending p24 proteins to the plasma membrane and vice versa. Finally, we show that p24 loss expands the COPII zone at ERES and increases the number of ER–Golgi vesicles, supporting a restrictive role of p24 proteins on vesicle budding for efficient transport. Our results reveal Tango1–p24 interplay as central to the generation of a stable ER–Golgi interface.
Machine learning for structural design models of continuous beam systems via influence zones
Authors: Gallet Adrien , Liew Andrew , Hajirasouliha Iman , Smyl Danny
Published: March 2024

This work develops a machine learned structural design model for continuous beam systems from the inverse problem perspective. After demarcating between forward, optimisation and inverse machine learned operators, the investigation proposes a novel methodology based on the recently developed influence zone concept which represents a fundamental shift in approach compared to traditional structural design methods. The aim of this approach is to conceptualise a non-iterative structural design model that predicts cross-section requirements for continuous beam systems of arbitrary system size. After generating a dataset of known solutions, an appropriate neural network architecture is identified, trained, and tested against unseen data. The results show a mean absolute percentage testing error of 1.6% for cross-section property predictions, along with a good ability of the neural network to generalise well to structural systems of variable size. The CBeamXP dataset generated in this work and an associated python-based neural network training script are available at an open-source data repository to allow for the reproducibility of results and to encourage further investigations.
Vision transformer-based electronic nose for enhanced mixed gases classification
Authors: Du Haiying , Shen Jie , Wang Jing , Li Qingyu , Zhao Long , He Wanmin , Li Xianrong
Published: March 2024

The classification of mixed gases is one of the major functions of the electronic nose. To address the challenges associated with complex feature construction and inadequate feature extraction in gas classification, we propose a classification model for gas mixtures based on the vision transformer (ViT). The whole-process signals of the sensor array are taken as input signals in the proposed classification model, and self-attention mechanism is employed for the fusion of global information and adaptive feature extraction to make full use of the dependence of responses at different stages of the whole-process signals to improve the model’s classification accuracy. Our model exhibited a remarkable accuracy (96.66%) using a dataset containing acetone, methanol, ammonia, and their binary mixtures. In comparison, experiments conducted by support vector machine and a one-dimensional deep convolutional neural network model demonstrated classification accuracy of 90.56% and 92.75%, respectively. Experimental results indicate that the ViT gas classification model can be effectively combined with multi-channel time series data from the sensor array using the self-attention mechanism, thereby improving the accuracy of mixed gases classification. This advancement can be expected to become a standard method for classifying mixed gases.
Temporal and spatial flow field reconstruction from low-resolution PIV data and pressure probes using physics-informed neural networks
Authors: Lai Bozhen , Liu Yingzheng , Wen Xin
Published: March 2024

In this paper, we present an innovative approach using physics-informed neural networks to reconstruct high-frequency, full-field flows, including the pressure field, by integrating sparse, noisy, low-temporal-resolution particle image velocimetry (PIV) data with high-temporal-resolution pressure probe data. This method effectively leverages the spatial richness of PIV data and the temporal abundance of pressure probe data, offering a complementary spatial and temporal data fusion. The incorporation of physical laws via equation constraints enables the neural network to accurately learn and predict complex fluid dynamics, achieving comprehensive flow field reconstructions. Rigorous testing across various flow types—periodic, non-periodic, and complex—against critical parameters like sampling interval (SI), number of grid points per snapshot (NGPIS), and number of pressure probes (NPP) has demonstrated remarkable accuracy. The results show reconstruction errors for velocity components (u, v) and pressure (p) below 5% with sufficient data, and around 10% for v and p, and below 5% for u in data-limited scenarios. A case study with SI = 30, NGPIS = 2000, NPP = 5 underscores the enhanced robustness and accuracy of random sampling, especially under various noisy conditions. Thus, this approach shows significant potential for temporal and spatial reconstruction of flow fields.
Multi-scale adversarial learning with difficult region supervision learning models for primary tumor segmentation
Authors: Zheng Shenhai , Sun Qiuyu , Ye Xin , Li Weisheng , Yu Lei , Yang Chaohui
Published: March 2024

Objective. Recently, deep learning techniques have found extensive application in accurate and automated segmentation of tumor regions. However, owing to the variety of tumor shapes, complex types, and unpredictability of spatial distribution, tumor segmentation still faces major challenges. Taking cues from the deep supervision and adversarial learning, we have devised a cascade-based methodology incorporating multi-scale adversarial learning and difficult-region supervision learning in this study to tackle these challenges. Approach. Overall, the method adheres to a coarse-to-fine strategy, first roughly locating the target region, and then refining the target object with multi-stage cascaded binary segmentation which converts complex multi-class segmentation problems into multiple simpler binary segmentation problems. In addition, a multi-scale adversarial learning difficult supervised UNet (MSALDS-UNet) is proposed as our model for fine-segmentation, which applies multiple discriminators along the decoding path of the segmentation network to implement multi-scale adversarial learning, thereby enhancing the accuracy of network segmentation. Meanwhile, in MSALDS-UNet, we introduce a difficult region supervision loss to effectively utilize structural information for segmenting difficult-to-distinguish areas, such as blurry boundary areas. Main results. A thorough validation of three independent public databases (KiTS21, MSD’s Brain and Pancreas datasets) shows that our model achieves satisfactory results for tumor segmentation in terms of key evaluation metrics including dice similarity coefficient, Jaccard similarity coefficient, and HD95. Significance. This paper introduces a cascade approach that combines multi-scale adversarial learning and difficult supervision to achieve precise tumor segmentation. It confirms that the combination can improve the segmentation performance, especially for small objects (our codes are publicly availabled on https://zhengshenhai.github.io/).
Hybrid-supervised deep learning for domain transfer 3D protoacoustic image reconstruction
Authors: Lang Yankun , Jiang Zhuoran , Sun Leshan , Xiang Liangzhong , Ren Lei
Published: March 2024

Objective. Protoacoustic imaging showed great promise in providing real-time 3D dose verification of proton therapy. However, the limited acquisition angle in protoacoustic imaging induces severe artifacts, which impairs its accuracy for dose verification. In this study, we developed a hybrid-supervised deep learning method for protoacoustic imaging to address the limited view issue. Approach. We proposed a Recon-Enhance two-stage deep learning method. In the Recon-stage, a transformer-based network was developed to reconstruct initial pressure maps from raw acoustic signals. The network is trained in a hybrid-supervised approach, where it is first trained using supervision by the iteratively reconstructed pressure map and then fine-tuned using transfer learning and self-supervision based on the data fidelity constraint. In the enhance-stage, a 3D U-net is applied to further enhance the image quality with supervision from the ground truth pressure map. The final protoacoustic images are then converted to dose for proton verification. Main results. The results evaluated on a dataset of 126 prostate cancer patients achieved an average root mean squared errors (RMSE) of 0.0292, and an average structural similarity index measure (SSIM) of 0.9618, out-performing related start-of-the-art methods. Qualitative results also demonstrated that our approach addressed the limit-view issue with more details reconstructed. Dose verification achieved an average RMSE of 0.018, and an average SSIM of 0.9891. Gamma index evaluation demonstrated a high agreement (94.7% and 95.7% for 1%/3 mm and 1%/5 mm) between the predicted and the ground truth dose maps. Notably, the processing time was reduced to 6 s, demonstrating its feasibility for online 3D dose verification for prostate proton therapy. Significance. Our study achieved start-of-the-art performance in the challenging task of direct reconstruction from radiofrequency signals, demonstrating the great promise of PA imaging as a highly efficient and accurate tool for in
vivo 3D proton dose verification to minimize the range uncertainties of proton therapy to improve its precision and outcomes.
Energy-dependent implementation of secondary electron emission models in continuum kinetic sheath simulations
Authors: Bradshaw Kolter , Srinivasan Bhuvana
Published: March 2024

The plasma-material interactions present in multiple fusion and propulsion concepts between the flow of plasma through a channel and a material wall drive the emission of secondary electrons. This emission is capable of altering the fundamental structure of the sheath region, significantly changing the expected particle fluxes to the wall. The emission spectrum is separated into two major energy regimes, a peak of elastically backscattered primary electrons at the incoming energy, and cold secondary electrons inelastically emitted directly from the material. The ability of continuum kinetic simulations to accurately represent the secondary electron emission is limited by relevant models being formulated in terms of monoenergetic particle interactions which cannot be applied directly to the discrete distribution function. As a result, rigorous implementation of energy-dependent physics is often neglected in favor of simplified, constant models. We present here a novel implementation of semi-empirical models in the boundary of continuum kinetic simulations which allows the full range of this emission to be accurately captured in physically-relevant regimes.
On the criteria for superconducting superlattices using CaCuO2
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Authors: Ikeda Ai , Krockenberger Yoshiharu , Taniyasu Yoshitaka , Yamamoto Hideki
Published: March 2024

The manifestation of superconductivity in cuprate superconductors is concerted to copper-oxygen planes. To maintain charge neutrality, the copper-oxygen planes are embedded between materials, that are electronically insulating. Here, we introduce BaBiO3, LaCrO3, EuFeO3, and Ca2Fe2O5 as candidate materials. We use molecular beam epitaxy as a synthesis tool for the development of artificial superconducting superlattices in combination with infinte-layer CaCuO2. We find that (1) layer lattice matching, (2) thermodynamic compatibility and (3) absence of diffusion of any element other than Cu into CuO2 planes are key criteria to realize superconductivity. For brown-millerite Ca2Fe2O5/CaCuO2 superlattices, criteria 1–3 are met and superconductivity emerges.
Reliable ferroelectricity down to cryogenic temperature in wake-up free Hf0.5Zr0.5O2 thin films by thermal atomic layer deposition
Authors: Wu Shuyu , Cao Rongrong , Jiang Hao , Li Yu , Zhang Xumeng , Yang Yang , Wang Yan , Wei Yingfen , Liu Qi
Published: March 2024

The performance and reliability of ferroelectric thin films at temperatures around a few Kelvin are critical for their application in cryo-electronics. In this work, TiN/Hf0.5Zr0.5O2/TiN capacitors that are free from the wake-up effect are investigated systematically from room temperature (300 K) to cryogenic temperature (30 K). We observe a consistent decrease in permittivity (ε
r) and a progressive increase in coercive electric field (E
c) as temperatures decrease. Our investigation reveals exceptional stability in the double remnant polarization (2P
r) of our ferroelectric thin films across a wide temperature range. Specifically, at 30 K, a 2P
r of 36 µC/cm2 under an applied electric field of 3.0 MV/cm is achieved. Moreover, we observed a reduced fatigue effect at 30 K in comparison to 300 K. The stable ferroelectric properties and endurance characteristics demonstrate the feasibility of utilizing HfO2 based ferroelectric thin films for cryo-electronics applications.
A novel one-time-programmable memory unit based on Schottky-type p-GaN diode
Authors: Feng Chao , Dai Xinyue , Jiang Qimeng , Huang Sen , Fan Jie , Wang Xinhua , Liu Xinyu
Published: March 2024

In this work, a novel one-time-programmable memory unit based on a Schottky-type p-GaN diode is proposed. During the programming process, the junction switches from a high-resistance state to a low-resistance state through Schottky junction breakdown, and the state is permanently preserved. The memory unit features a current ratio of more than 103, a read voltage window of 6 V, a programming time of less than 10−4 s, a stability of more than 108 read cycles, and a lifetime of far more than 10 years. Besides, the fabrication of the device is fully compatible with commercial Si-based GaN process platforms, which is of great significance for the realization of low-cost read-only memory in all-GaN integration.
Visible-to-near-infrared photodetectors based on SnS/SnSe2 and SnSe/SnSe2 p−n heterostructures with a fast response speed and high normalized detectivity
Authors: Zhu Xinfa , Duan Weishuai , Meng Xiancheng , Jia Xiyu , Zhang Yonghui , Zhou Pengyu , Wang Mengjun , Zheng Hongxing , Fan Chao
Published: March 2024

The emergent two-dimensional (2D) material, tin diselenide (SnSe2), has garnered significant consideration for its potential in image capturing systems, optical communication, and optoelectronic memory. Nevertheless, SnSe2-based photodetection faces obstacles, including slow response speed and low normalized detectivity. In this work, photodetectors based on SnS/SnSe2 and SnSe/SnSe2 p−n heterostructures have been implemented through a polydimethylsiloxane (PDMS)−assisted transfer method. These photodetectors demonstrate broad-spectrum photoresponse within the 405 to 850 nm wavelength range. The photodetector based on the SnS/SnSe2 heterostructure exhibits a significant responsivity of 4.99 × 103 A∙W−1, normalized detectivity of 5.80 × 1012 cm∙Hz1/2∙W−1, and fast response time of 3.13 ms, respectively, owing to the built-in electric field. Meanwhile, the highest values of responsivity, normalized detectivity, and response time for the photodetector based on the SnSe/SnSe2 heterostructure are 5.91 × 103 A∙W−1, 7.03 × 1012 cm∙Hz1/2∙W−1, and 4.74 ms, respectively. And their photodetection performances transcend those of photodetectors based on individual SnSe2, SnS, SnSe, and other commonly used 2D materials. Our work has demonstrated an effective strategy to improve the performance of SnSe2-based photodetectors and paves the way for their future commercialization.