bluuebunny/crossref_metadata_2025 huggingface dataset:
Bilayer MSe2 (M = Zr, Hf, Mo, W) performance as a hopeful thermoelectric materials
Authors: Jobayr Mahmood Radhi , Salman Ebtisam M-T.
Published: March 2023

Significant advancements in nanoscale material efficiency optimization have made it feasible to substantially adjust the thermoelectric transport characteristics of materials. Motivated by the prediction and enhanced understanding of the behavior of two-dimensional (2D) bilayers (BL) of zirconium diselenide (ZrSe2), hafnium diselenide (HfSe2), molybdenum diselenide (MoSe2), and tungsten diselenide (WSe2), we investigated the thermoelectric transport properties using information generated from experimental measurements to provide inputs to work with the functions of these materials and to determine the critical factor in the trade-off between thermoelectric materials. Based on the Boltzmann transport equation (BTE) and Barden-Shockley deformation potential (DP) theory, we carried out a series of investigative calculations related to the thermoelectric properties and characterization of these materials. The calculated dimensionless figure of merit (ZT) values of 2DBL-MSe2 (M = Zr, Hf, Mo, W) at room temperature were 3.007, 3.611, 1.287, and 1.353, respectively, with convenient electronic densities. In addition, the power factor is not critical in the trade-off between thermoelectric materials but it can indicate a good thermoelectric performance. Thus, the overall thermal conductivity and power factor must be considered to determine the preference of thermoelectric materials.
Pinning energies of organic semiconductors in high-efficiency organic solar cells
Authors: Li Xian’e , Zhang Qilun , Liu Xianjie , Fahlman Mats
Published: March 2023

With the emergence of new materials for high-efficiency organic solar cells (OSCs), understanding and finetuning the interface energetics become increasingly important. Precise determination of the so-called pinning energies, one of the critical characteristics of the material to predict the energy level alignment (ELA) at either electrode/organic or organic/organic interfaces, are urgently needed for the new materials. Here, pinning energies of a wide variety of newly developed donors and non-fullerene acceptors (NFAs) are measured through ultraviolet photoelectron spectroscopy. The positive pinning energies of the studied donors and the negative pinning energies of NFAs are in the same energy range of 4.3−4.6 eV, which follows the design rules developed for fullerene-based OSCs. The ELA for metal/organic and inorganic/organic interfaces follows the predicted behavior for all of the materials studied. For organic–organic heterojunctions where both the donor and the NFA feature strong intramolecular charge transfer, the pinning energies often underestimate the experimentally obtained interface vacuum level shift, which has consequences for OSC device performance.
A fuzzy granular logistic regression algorithm for sEMG-based cross-individual prosthetic hand gesture classification
Authors: Diao Yanan , Chen Qiangqiang , Liu Yan , He Linjie , Sun Yue , Li Xiangxin , Chen Yumin , Li Guanglin , Zhao Guoru
Published: March 2023

Objective. Prosthetic systems are used to improve the quality of life of post-amputation patients, and research on surface electromyography (sEMG)-based gesture classification has yielded rich results. Nonetheless, current gesture classification algorithms focus on the same subject, and cross-individual classification studies that overcome physiological factors are relatively scarce, resulting in a high abandonment rate for clinical prosthetic systems. The purpose of this research is to propose an algorithm that can significantly improve the accuracy of gesture classification across individuals. Approach. Eight healthy adults were recruited, and sEMG data of seven daily gestures were recorded. A modified fuzzy granularized logistic regression (FG_LogR) algorithm is proposed for cross-individual gesture classification. Main results. The results show that the average classification accuracy of the four features based on the FG_LogR algorithm is 79.7%, 83.6%, 79.0%, and 86.1%, while the classification accuracy based on the logistic regression algorithm is 76.2%, 79.5%, 71.1%, and 81.3%, the overall accuracy improved ranging from 3.5% to 7.9%. The performance of the FG_LogR algorithm is also superior to the other five classic algorithms, and the average prediction accuracy has increased by more than 5%. Conclusion. The proposed FG_LogR algorithm improves the accuracy of cross-individual gesture recognition by fuzzy and granulating the features, and has the potential for clinical application. Significance. The proposed algorithm in this study is expected to be combined with other feature optimization methods to achieve more precise and intelligent prosthetic control and solve the problems of poor gesture recognition and high abandonment rate of prosthetic systems.
Model Predictive Current Control for Asymmetric Six-phase Permanent Magnet Motors With Less Computation and Optimized Voltage Vector Magnitude
Authors: Sun Jinyu , Chen Fubing
Published: March 2023

For the sake of the fixed magnitude of candidate control sets, the conventional model predictive current control (MPCC) for asymmetric six-phase permanent magnet motors suffers from huge harmonic currents. This article designs a novel MPCC that aims to improve operational performance. First, virtual-voltage vector (VV) sets are synthesized as the new candidate vectors to restrain harmonic currents. Then, a simplified method for evaluating voltage vectors is used to alleviate the computation in the enumeration process. Moreover, the duty cycle modulation with the deadbeat solution is introduced to optimize the magnitude of the VV. The modulation range can be expanded by utilizing null vectors, which will significantly reduce the torque fluctuations and flux ripples. The experiments are conducted to verify the designed control strategy.
A Damping Control for DC Distribution System Under Isolated Operation Mode
Authors: Liu Beiyuan
Published: March 2023

There are risks of resonant instability exiting in the DC distribution system configured with battery energy storage devices because of capacitors and inductors in the network with fast speed-controlled DC-DC converters. The DC distribution system needs battery energy storage devices to provide DC voltage support when it operates in an isolated island mode because of no AC or DC sources at that moment. To explore the key factors affecting the resonant instability of DC network, a three-terminal DC network consisting of DC voltage control, constant current control, and constant power load is used for state space modeling. Research results show that the inductors for faults current limitation interacting with the capacitors under high constant power load is the main reason causing instability. The other reason is the large parameter of the current controller. To suppress the resonant instability of the DC distribution system, a damping control strategy by filtering DC voltage in advance to the current control loop is proposed, and the parameters are selected using the roots locus method. Simulations verify the correctness and effectiveness of the proposed method.
Brushless DC Motor Common-mode Voltage Analysis
Authors: Wei Hongye , Wang Xiuhe , Wang Xinghua
Published: March 2023

Brushless DC motors (BLDCMs) with their own performance of obvious advantages: good speed regulation performance and high efficiency. BLDCMs have continuously replaced brushed DC and induction motors in many competitive fields and obtained more extensive applications. The common-mode voltage (CMV) in the motor parasitic capacitance coupling in the motor shaft induces the shaft voltage. It then triggers the shaft current, resulting in electrical corrosion of the bearing. It is necessary to conduct a systematic scientific analysis of its CMV. For different modulation methods, the phase voltages under three conditions without PWM modulation, HPWM_LPWM modulation, and HPWM_LON modulation are studied, FFT, and then the CMV is analyzed. Then, the correctness of the analysis is verified by simulation analysis.
Analysis of Dynamic Response and Current-Carrying Capacity of Bridge-along Cable under Typhoon Load
Authors: Qian Gang , Cong Yun , Zheng Xinlong , Zhang Zhenpeng , Yan Xunping , Liu Jinjuan , Chen Zhipeng
Published: March 2023

In order to study the structural dynamic response and dynamic load capacity of bridge-along cable under typhoon load, in this paper, the cable under two laying environments, including the steel box girder and steel platform, are taken as the research object. Shiyuan typhoon spectrum and harmonic superposition method are adopted to obtain the wind speed time history curves corresponding to different scales of typhoon wind force, then the wind-induced pulsating displacement of steel box girder and steel platform is calculated by using the wind speed time history curve. The electromagnetic-thermal-structure coupling model is established, and the obtained pulsating displacement under typhoon load is applied to the cable as a boundary condition to obtain its dynamic response characteristics. The eccentricity of XLPE insulation is used as the evaluation index of the current-carrying capacity of cable under different scales of typhoon wind force and different laying environments. The simulation results show that the maximum stress amplitude on the metal layer occurs near the clamp during cables are forced to move under typhoon load. The higher the typhoon wind force, the lower the allowable current-carrying capacity. Under wind force 10, the current-carrying capacity is not affected by the typhoon weather; under wind force 11, the current-carrying capacity dropped by 17.2%; under wind force 12, the current-carrying capacity dropped by 47.7%; under wind force 13, the cables are not recommended to work. The research results provide theoretical guidance for assessing the power supply reliability of bridge-along cables under typhoon disasters.
Research and Application of Mechanical State Diagnosis Method of Horizontal Telescopic Type Disconnector
Authors: Yang Tao , Wang Bing , Bao You-Zhi , Xu Ji-Yong , Niu Bo-Rui , Liu Yu-Fei , He Song
Published: March 2023

Most transmission parts of the horizontal telescopic type disconnector are directly exposed, resulting in frequent mechanical failures. Its mechanical state is mainly judged by manual operation experience, so it is not easy to achieve rapid and accurate evaluation. In this paper, by establishing the virtual prototype model of the horizontal telescopic type disconnector and building the corresponding test platform, the changing trend of torque in the movement process of the disconnector is analyzed. Compared with the torque-angle curves of the normal state and different mechanical defects’ states, the closing and opening process’s torque increases obviously under the jamming defect. The opening process is torque increases while the closing process’s torque decreases under the spring fatigue defect. The ending torque value of the closing process increases, or there is no typical wave peak in the meshing stage under improper travel defect. There are multiple wave peaks in the meshing stage under the three-phase position asynchrony. With this, the mechanical state diagnosis method of GW23 disconnector based on the torque-angle curve is summarized, and the installation and debugging of the same type of disconnectors in a substation are taken as examples to prove that the rapid and accurate diagnosis of its mechanical state can be realized by using this method in engineering application.
Ranging Algorithm of UAV Inspection of Transmission Line Based on Monocular Vision and SURF Method
Authors: Li Bocheng , Li Wen , Zhang Liang , Yang Haoyan , Chen Ziwei , Lei Tian , Wang Xiao
Published: March 2023

In view of the complexity and economy in the inspection of transmission lines by drones, a monocular ranging model based on consideration of the length and flight attitude of the object being measured is proposed to measure distances, which effectively solves the UAV ranging problem in the inspection. The range measurement procedure is divided into three parts: processing and recognition of images taken by drones, performing camera calibration experiments to obtain internal and external parameters of the camera, and building a distance measurement model to perform distance calculations. Finally, this article compares the calculated results with the actual distances and draws conclusions.
Open-circuit fault diagnosis method for inverters using deep learning and the evidence reasoning rule
Authors: Yu Hang , Gao Haibo , He Yelan , Lin Zhiguo , Xu Xiaobin , Pan Zhiqiang
Published: March 2023

Inverters having high voltage levels, high power density, and high integration are widely used. However, many high-frequency switch units also increase the probability of failure. Therefore, developing an accurate and stable fault diagnosis method is necessary. This paper proposes a fault diagnosis algorithm based on deep learning and the evidence reasoning (ER) rule. It not only ensures high diagnostic accuracy, but also enhances the stability of the diagnostic results. The algorithm takes the three-phase voltage source inverter as the research object and extracts the three-phase current signals with different types of faults as features. First, Convolutional and Deep Neural Network methods were utilized independently to determine a preliminary diagnosis. Second, the softmax functions of the Convolutional and Deep Neural Network outputs provided the probability distribution of the fault category, which was used as the evidence body for the ER rule to construct the fusion diagnosis. In addition, a new method of determining the reliability and the importance factors of the evidence was proposed in which the evaluation index of the deep-learning diagnosis result was applied. Finally, the final classification result was obtained using the ER rule. The proposed method can effectively enhance the accuracy and robustness compared with a single classifier.
Dynamic Buckling Analysis of the Cylindrical Shell with Radial Stiffness and Damping Constraints under Axially Impact
Authors: Gui Yifei , Xu Jiaxin , Ren Juhui
Published: March 2023

The governing equation of a cylindrical shell with radial stiffness and damping constraints is established and then solved. The bifurcation conditions of buckling are obtained given boundary conditions and consistency conditions. The critical loads and buckling modes are analyzed. The results reveal both radial stiffness and damping constraints will enhance the anti-buckling capacity of cylindrical shells, and the capacity of the former is better than that of the latter. The radial stiffness and damping values will have a great influence on the critical load when they are small but do not have much influence on the critical load with increasing their values.
Numerical Simulation on Structural Integrity of Grain with Large Increased Area Ratio for Solid Rocket Motor
Authors: Wang S X , Bai J Q , Zuo Y X , Qiang X W , Wang H L , Yan Q X
Published: March 2023

To evaluate the structural integrity of a type of solid rocket motor grain with a largely increased area ratio using free-loading modified double-base grain, the Schapery integral nonlinear viscoelastic constitutive equation with damage is derived, and the numerical simulation model of solid rocket motor grain is constructed. According to the mission profile of the grain during the equipment period, the numerical simulation research on the mechanical response characteristics of the grain under three typical working conditions, namely, platform vibration, underwater explosion impact, and ignition pressurization during the launch is carried out. The simulation results show that under the three typical working conditions, the grain will not produce structural damage and defects, and the mechanical response of the grain under the platform vibration and explosion impact load is far less than that under the launch ignition pressurization. The ignition pressurization should be considered in the grain structural integrity design of this type or similar structure solid rocket motor.
A General Approach for the Analysis of Transverse Vibration Characteristics of a Rectangular Plate with Arbitrary-shaped Openings
Authors: Zhang Wenwen
Published: March 2023

Based on the Rayleigh-Ritz method, the transverse vibration characteristics of a rectangular plate with an arbitrarily shaped inner opening are investigated. A modified two-dimensional Fourier series was chosen as the trial function and springs of different stiffnesses were used to equate the arbitrary boundary conditions of the rectangular plate. The Lagrange generalization of the transverse vibration of the open rectangular plate is obtained by equating the open area to a special film with physical properties of zero according to the energy superposition principle. The variational method is used to derive the characteristic equations of the thin plate and to find the intrinsic frequencies and corresponding vibration modes. The convergence of this theoretical method is analyzed by means of an example, and the accuracy of the method is verified by comparison with the results of finite element software calculations, which provides a reference for practical engineering problems.
Effect of Tip Clearance Size on the Cavitation Flow and Noise Characteristics of the NACA0009 Hydrofoil
Authors: Zhou Yudi
Published: March 2023

The noise characteristics of NACA0009 hydrofoil with tip clearance are discussed. Select SST k- ω Turbulence model and Schnerr Sauer cavitation model simulate tip leakage cavitation flow. The results show that the simulation results are in good agreement with the original records, and the tip clearance reduces the energy characteristics of the hydrofoil. With the expansion of tip clearance model, TLV and cavitation compressive strength gradually decrease. In addition, the study of far-field noise shows that the nonspecific curve of the total noise coefficient of far-field noise shows a disc shaped symmetric structure. Compared with the original hydrofoil, when the tip clearance is 20 mm, the far-field dipole noise value at 170 ° angle is reduced by 17.68%. Tip clearance reduces offline and far-field noise. Far field noise decreases with the increase of tip clearance model.
Estimates for the minimum eigenvalue of an M-matrix
Authors: Zhong Qin , Li Ling
Published: March 2023

New sharper lower bounds for the minimal eigenvalues of symmetric M-matrices and nonsymmetric M-matrices are proposed by constructing two increasing sequences. By contrasting the proposed instances with the related findings, two instances are offered to demonstrate the effectiveness of the technique.
Fractal metasurface for THz applications with polarization and incidence angle insensitivity
Authors: Abdel Aziz Ahmed A. , Abdelsallam Ali , Gaafar Abdelhamid Ali , Abdalla Mahmoud A.
Published: March 2023

A Fractal metasurface-based absorber is designed to obtain a
wideband absorption in THz frequency band. The developed absorber
has a broadband absorption over more than 600 GHz bandwidth, from
0.6 THz to 1.2 THz, with a minimum absorption percentage of 70%
and total absorption from 1 to 1.1 THz. The proposed fractal
structure is investigated using a Modified Split Ring Resonator
(MSRR). The absorption coefficient of the proposed fractal
metasurface is compared with the modified initially SRR
metasurface. The results indicate that by using fractal design, the
metasurface operating band is summed up, resulting in a wide
bandwidth. The absorption coefficient of the proposed fractal
metasurface is studied using two different simulation software
programs to ensure the obtained results, with a high agreement
between the results of them. The designed metasurface has a similar
absorption response for the different polarization of the incident
wave. The impedance of the designed metasurface indicates that, for
the operating band, the fractal metasurface has a surface impedance
of around 377 Ω, indicating a good matching between the
designed metasurface and air. Different incidence and polarization
angles are studied with results showing its insensitivity to both of
them. The designed metasurface is compared with previously published
works, showing wider bandwidth, higher absorption, and incidence and
polarization insensitivity. The proposed metasurface absorber can be
used for biomedical applications.
Theoretical principles and practical aspects of the theory of transformation of interaction measures with external objects and the environment for ground robot complexes
Authors: Zalypka V
Published: March 2023

The guiding documents regarding ground robotic complexes (GRC) of the USA were analyzed and it was found that the basis of the development of modern GRC is artificial intelligence. It was found out that GRC is the preservation of life and health of servicemen in battle. It was established that the transformation of the means of interaction with external objects and the environment (MIEOE) is due to the need to improve the operational properties of the GRC. A new idea is proposed to provide a dual function of the MIEOE for the GRC due to their transformation. Individual cases of the transformation of the wheel drive and the design of the manipulators were analyzed, and a mathematical description of the transformation of the circle into figures for the construction of the wheel drives of the GRC of increased cross-country ability was carried out. It has been established that the promising MIEOE GRC can be manufactured in a combination of different materials and combine the latest technologies for the use of gallium nitride transistors, soft crystals and graphene thread (films).
Modeling the sequence of part machining to minimize the time spent on the machining center, considering the working tool changing
Authors: Matviishyn Yevhen
Published: March 2023

An algorithm for choosing a rational sequence for machining a part on a machine with a tool magazine is proposed using the drilling operations example. The algorithm is based on the analysis of all possible options and the calculation of the time spent on each of them. In this respect, the working tool (drill) change is considered, if it is necessary to switch to another machining type (drilling a different diameter hole). Three types of time costs are included in the calculation of the total machining time for one part: the duration of each operation, the duration of the transition to the next operation, and the duration of the working tool change. The result of the algorithm application is the sequence of machining the part with the least total time spent on transitions to the machining areas and the working tool changing.
Special features of the dynamic cutting process analysis in the machining of titanium alloys
Authors: She Xianning , Yevtushenko N
Published: March 2023

The achievement of high accuracy parameters and the surface layer quality of the machined surface greatly depends on the dynamic stability of the system “Machine-Fixture-Tool-Workpiece”. It is especially important for machining titanium alloys because intensive tool vibrations are generated due to the adiabatic shear phenomenon. The causes and consequences of such effects are described in the article. The paper also describes a specific method for studying the dynamic state of the cutting system of titanium alloys, based on the system integration of the classical method of the analytical description of the vibration processes arising when machining and the method of rheological simulation of the cutting process. Two important problems are proposed to be solved for the effective analysis of the system modeling results: first, it is the filtering of the noise signal with preservation of the limiting values of modeling results and maximum sensitivity using the Savitsky-Golay mathematical apparatus; second, the problem of approximation and interpolation of the filtered function of cutting parameters by Fourier transform in time.
Analysis of exploration parameters of industrial car jack used in car services in Kazakhstan
Authors: Nurkusheva Saltanat , Bembenek Michał
Published: March 2023

This article deals with the problem of the effective use of car jacks for passenger cars. The aim of the study is to create a theoretical basis for improving the efficiency and safety of the application of car jacks in car service enterprises. Based on the analysis of the review of existing designs, which are used in the technological process of car service, the universal classification of the car jack is modernized. As a result of the study, a comparison of technical indicators of the types of car jacks used in car service centers in Kazakhstan has been carried out. We propose an optimal range of load capacity. The results of the work, when implemented in the practice of design, will provide a reasonable reduction in the present costs of equipping the lifting equipment in car service stations and the operation of car jacks at the expense of more advanced methods of calculation and design.
A handheld bioprinter for multi-material printing of complex constructs
Authors: Pagan Erik , Stefanek Evan , Seyfoori Amir , Razzaghi Mahmood , Chehri Behnad , Mousavi Ali , Arnaldi Pietro , Ajji Zineb , Dartora Daniela Ravizzoni , Dabiri Seyed Mohammad Hossein , Nuyt Anne Monique , Khademhosseini Ali , Savoji Houman , Akbari Mohsen
Published: March 2023

In situ bioprinting—the process of depositing bioinks at a defected area, has recently emerged as a versatile technology for tissue repair and restoration via site-specific delivery of pro-healing constructs. The ability to print multiple materials in situ is an exciting approach that allows simultaneous or sequential dispensing of different materials and cells to achieve tissue biomimicry. Herein, we report a modular handheld bioprinter that deposits a variety of bioinks in situ with exquisite control over their physical and chemical properties. Combined stereolithography 3D printing and microfluidic technologies allowed us to develop a novel low-priced handheld bioprinter. The ergonomic design of the handheld bioprinter facilitate the shape-controlled biofabrication of multi-component fibers with different cross-sectional shapes and material compositions. Furthermore, the capabilities of the produced fibers in the local delivery of therapeutic agents was demonstrated by incorporating drug-loaded microcarriers, extending the application of the printed fibers to on-demand, temporal, and dosage-control drug delivery platforms. Also, the versatility of this platform to produce biosensors and wearable electronics was demonstrated via incorporating conductive materials and integrating pH-responsive dyes. The handheld printer’s efficacy in generating cell-laden fibers with high cell viability for site-specific cell delivery was shown by producing single-component and multi-component cell-laden fibers. In particular, the multi-component fibers were able to model the invasion of cancer cells into the adjacent tissue.
Comparative radiosensitization efficiency assessment of graphene oxide and Ti3C2 MXene as 2D carbon-based nanoparticles against breast cancer cells: characterization, toxicity and mechanisms
Authors: Joze-Majidi Hoomaan , Zabihi Erfan , Arab-Bafrani Zahra , Mir Seyed Mostafa , Reiter Russel J
Published: March 2023

The efficacy of two carbon-based nanomaterials, graphene oxide (GO) and Ti3C2 MXene (MX), on the radiosensitivity of the breast cancer cells (BCCs) was investigated using clinical x-ray irradiation. The prepared GO and MX nanoparticles (NPs) were firstly characterized utilizing Fourier transform infrared, ultraviolet–visible, atomic force microscopy and transmission electron microscopy techniques and subsequently assessed in terms of their radiobiological properties. The results of the cell toxicity assay indicated that neither NPs exhibited significant cytotoxicity after 48 h incubation with BCC up to 50 µg ml−1 concentration without irradiation. The cell internalization results showed an approximately equivalent cellular uptake for both NPs after 6 h incubation with BCC. Our comparative studies with radiotherapy demonstrated that both NPs substantially increased cell proliferation inhibition and cell apoptosis of BCC under x-ray irradiation when compared to BCC treated with irradiation alone. Additionally, the 2ʹ,7ʹ-dichlorofluorescin diacetate flow cytometry results and fluorescent microscopy images revealed that both NPs remarkably increased the level of intracellular reactive oxygen species (ROS) generation in BCC under x-ray irradiation. The MX nanosheets exhibited superior radiosensitization efficiency than GO under x-ray irradiation due to its higher level of intracellular ROS generation (MX = 75.2% and GO = 65.2%). Clonogenic cell survival assay and extracted radiobiological parameters revealed that both NPs in combination with x-ray irradiation induced more lethal damage and less sublethal damage to BCC. Generally, the obtained results demonstrate that the MX NPs, as a stronger radiosensitizer than GO, could be a promising candidate for enhancing the effectiveness of radiotherapy in breast cancer treatment.
The motion and growth behaviors of nucleuses in Al melt solidified under supergravity condition—molecular dynamics simulation
Authors: Gan Xianglai , Hu Wangyu , Huang Bowen
Published: March 2023

That supergravity can refine grains is verified in many materials. However, the underlying mechanism is still an open question. Although some convincing theories have been proposed, including the ‘crystal rain’ theory and the dendrite fragmentation theory, there is a lack of solid evidence, especially from the atomic scale. Based on the presetting nucleuses method, this study investigates the motion and growth behaviors of nucleuses during the solidification process of Al melt under supergravity condition with molecular dynamics simulation. It is found that supergravity builds a gradient pressure in the samples along the direction of supergravity, and the gradient pressure results in the gradient distribution of sample density. The preset nucleuses move directionally along the direction of supergravity forming ‘crystal rain’, while their directional moving velocity decreases due to the increase of buoyancy, which is caused by the increase of melt density in the motion path of the nucleuses. The supergravity-induced pressure not only decreases the critical size of nucleuses but also increases the growth velocity of nucleuses. The research results also indicate that larger nucleuses grow much faster than smaller ones at the same pressure. Owing to the gradient distribution of pressure, the nucleuses grow much faster along the direction of supergravity than other directions and evolve into an ‘inverted cone’ shape. Therefore, these findings show that supergravity can change the nucleation, motion and growth of nucleuses by establishing a gradient pressure in the melt, thus affecting the microstructure of the casting. Our results provide solid support for the ‘crystal rain’ theory and the nucleation rate rising theory from atomic scale.
Accurate and efficient protein sequence design through learning concise local environment of residues
Authors: Huang Bin , Fan Tingwen , Wang Kaiyue , Zhang Haicang , Yu Chungong , Nie Shuyu , Qi Yangshuo , Zheng Wei-Mou , Han Jian , Fan Zheng , Sun Shiwei , Ye Sheng , Yang Huaiyi , Bu Dongbo
Published: March 2023

Motivation

Computational protein sequence design has been widely applied in rational protein engineering and increasing the design accuracy and efficiency is highly desired.

Results

Here, we present ProDESIGN-LE, an accurate and efficient approach to protein sequence design. ProDESIGN-LE adopts a concise but informative representation of the residue’s local environment and trains a transformer to learn the correlation between local environment of residues and their amino acid types. For a target backbone structure, ProDESIGN-LE uses the transformer to assign an appropriate residue type for each position based on its local environment within this structure, eventually acquiring a designed sequence with all residues fitting well with their local environments. We applied ProDESIGN-LE to design sequences for 68 naturally occurring and 129 hallucinated proteins within 20 s per protein on average. The designed proteins have their predicted structures perfectly resembling the target structures with a state-of-the-art average TM-score exceeding 0.80. We further experimentally validated ProDESIGN-LE by designing five sequences for an enzyme, chloramphenicol O-acetyltransferase type III (CAT III), and recombinantly expressing the proteins in Escherichia coli. Of these proteins, three exhibited excellent solubility, and one yielded monomeric species with circular dichroism spectra consistent with the natural CAT III protein.

Availability and implementation

The source code of ProDESIGN-LE is available at https://github.com/bigict/ProDESIGN-LE.
Lentigo maligna and lentigo maligna melanoma in young patients in Australian tertiary centres
Authors: Huang Cheng , Burke Hazel , Scolyer Richard A , Guitera Pascale
Published: March 2023

This was a retrospective study of all patients with a diagnosis of lentigo maligna or lentigo maligna melanoma at 50 years of age or younger at the time of their first diagnosis in two Australian tertiary centres. The low recurrence rate in younger patients in this study warrants further investigation. Early diagnosis in young patients is crucial to allow early treatment and lifestyle changes to reduce actinic damage and subsequent development of further melanomas.
Generalized reddish-brown macules on a 51-year-old man
Authors: Yang Lu , Zeng Yue-Ping
Published: March 2023

A 51-year-old man presented with a 4-year history of pruritic papules and macules on his trunk and extremities, which were occasionally exacerbated by sunlight. Urticaria and erythema developed a few minutes after scratching. The patient was otherwise healthy, without any cardiovascular or constitutional symptoms.
High- vs. low-dose diclofenac and cardiovascular risks: a target trial emulation
Authors: Schmidt Morten , Arendt-Nielsen Lars , Hauge Ellen-Margrethe , Sørensen Henrik Toft , Pedersen Lars
Published: March 2023

Aims

To examine the dose dependency of diclofenac's cardiovascular risks.

Methods and results

Using Danish health registries and the target trial emulation design, we conducted a series of 300 nationwide cohort studies during 1996–2020, each mimicking the strict design criteria of a clinical trial. Adults eligible for inclusion had no recent non-steroidal anti-inflammatory drug prescriptions, contraindications (gastrointestinal diseases, thrombocytopenia, or heart failure), or conditions with low adherence (dementia or psychiatric disease). Diclofenac initiators were compared to healthcare-seeking non-initiators and head-to-head using an approximated high dose of ≥150 mg/day vs. low dose of <150 mg/day. Cox regression was used to compute the incidence rate ratio (IRR) of major adverse cardiovascular events (MACE) within 30 days following initiation. We adjusted for age, sex, calendar period, comorbidity, comedication, and socioeconomic position. Compared with non-initiators (n = 3 789 617), diclofenac initiators (n = 1 894 834) had an approximately 50% increased rate of MACE (IRR 1.53, 95% confidence interval [CI]: 1.43–1.63), reflecting IRRs of 1.54 (95% CI: 1.40–1.69) for myocardial infarction, 1.29 (1.14–1.45) for ischaemic stroke, and 1.92 (1.71–2.16) for cardiac death. The risk increase was observed for most conditions with chronic pain, in particular headache (IRR 5.10, 95% CI: 1.46–17.85). The risk increase was similar for initiators of high- (IRR 1.55, 95% CI: 1.40–1.71) and low-dose diclofenac (IRR 1.52, 1.41–1.63), which was confirmed in a head-to-head analysis (IRR 1.01, 95% CI: 0.90–1.12).

Conclusions

Initiators of high- and low-dose diclofenac had comparably increased cardiovascular risks. This finding provides evidence against the assumption that low-dose diclofenac is risk-neutral.
Adverse outcomes of atrial fibrillation ablation in heart failure patients with and without cardiac amyloidosis: a Nationwide Readmissions Database analysis (2015–2019)
Authors: Ullah Waqas , Ruge Max , Hajduczok Alexander G , Kochar Kirpal , Frisch Daniel R , Pavri Behzad B , Alvarez Rene , Rajapreyar Indranee N , Brailovsky Yevgeniy
Published: March 2023

Aims

Atrial fibrillation (AF) in patients with cardiac amyloidosis (CA) has been linked with a worse prognosis. The current study aimed to determine the outcomes of AF catheter ablation in patients with CA.

Methods and results

The Nationwide Readmissions Database (2015–2019) was used to identify patients with AF and concomitant heart failure. Among these, patients who underwent catheter ablation were classified into two groups, patients with and without CA. The adjusted odds ratio (aOR) of index admission and 30-day readmission outcomes was calculated using a propensity score matching (PSM) analysis. A total of 148 134 patients with AF undergoing catheter ablation were identified on crude analysis. Using PSM analysis, 616 patients (293 CA-AF, 323 non-CA-AF) were selected based on a balanced distribution of baseline comorbidities. At index admission, AF ablation in patients with CA was associated with significantly higher adjusted odds of net adverse clinical events (NACE) [adjusted odds ratio (aOR) 4.21, 95% CI 1.7–5.20], in-hospital mortality (aOR 9.03, 95% CI 1.12–72.70), and pericardial effusion (aOR 3.30, 95% CI 1.57–6.93) compared with non-CA-AF. There was no significant difference in the odds of stroke, cardiac tamponade, and major bleeding between the two groups. At 30-day readmission, the incidence of NACE and mortality remained high in patients undergoing AF ablation in CA.

Conclusion

Compared with non-CA, AF ablation in CA patients is associated with relatively higher in-hospital all-cause mortality and net adverse events both at index admission and up to 30-day follow-up.
Pubertal development and hypogonadism in males with autoimmune polyendocrinopathy–candidiasis–ectodermal dystrophy: a retrospective study
Authors: Träskilä Emilia , Holopainen Elina , Mäyränpää Mikko I , Toppari Jorma , Mäkitie Outi , Laakso Saila
Published: March 2023

The aim of this study was to describe the course of puberty and hypogonadism in males with autoimmune polyendocrinopathy–candidiasis–ectodermal dystrophy (APECED) in a Finnish APECED cohort followed up between 1970 and 2020. Anthropometry, testicular volumes and FSH, LH, and testosterone concentrations were analyzed retrospectively. Forty-three males were followed up until the median age of 42.5 years (range, 16.2-74.8). All subjects fulfilled the clinical criteria for APECED. The median age at the onset of spontaneous puberty was 13.3 years (10.8-14.8). Testosterone medication was used to promote pubertal development from the median age of 14.9 years (13.5-15.7), for 0.7-3.3 years in 8 patients. The median adult height was 173.0 cm and differed from the mid-parental target height on average −1.3 SDS (P < .001). Hypogonadism was treated in 6 patients (14%). Azoospermia was found in 3 patients. Further studies are required to explore the role of the autoimmune regulator in sperm production and testicular insufficiency.
First record ofFusarium concentricum(Hypocreales: Hypocreaceae) isolated from the mothPolychrosis cunninhamiacola(Lepidoptera: Tortricidae) as an entomopathogenic fungus
Authors: Qiu Hua-Long , Fox Eduardo G P , Qin Chang-Sheng , Yang Hua , Tian Long-Yan , Wang De-Sen , Xu Jin-Zhu
Published: March 2023

Fusarium concentricum Nirenberg & O’ Donnell (Ascomycota: Hypocreales) is a fungal species known to infect plants, but never reported as entomopathogenic. Polychrosis cunninhamiacola Liu et Pei (Lepidoptera: Tortricidae: Olethreutinae) is a major and widespread insect pest causing economic losses to cultivated Chinese fir Cunninghamia lanceolata (Lamb.) Hook. It is routinely controlled by extensive use of chemical insecticides, which is perceived as environmentally unsustainable. During March and April of 2019–2020, muscardine cadavers of larvae and pupae of P. cunninhamiacola infected with growing fungus were collected in a fir forest in northern Guangdong Province, China. Conidia were isolated and cultured on PDA medium, from which the fungal strain was identified as F. concentricum FCPC-L01 by morphology and by sequence alignment match with Tef-1α gene. Pathogenicity bioassays at the conidial concentration 1 × 107 revealed P. cunninhamiacola adults and Danaus chrysippus (L.) (Lepidoptera: Nymphalidae) larvae are sensitive to the fungal infection, but not the fire ant Solenopsis invicta Buren (Hymenoptera: Formicidae). We believe results indicate this fungal strain might be applicable against specific target insect pests. As this is the first record of a natural infection caused by F. concentricum in insects, we propose host specificity tests should be done to evaluate its potential as a biocontrol agent.
Burden of traumatic spinal cord injury in Africa: a scoping review protocol
Authors: Jesuyajolu Damilola , Ayantayo Temitayo , Oyesiji Emmanuel , Bakare Sofia , David Samuel Oreoluwa , Sule Rosola , Daniel Jeremiah , Madeleine Okere , Olukoya Tomiwa , Osunronbi Temidayo , Adewale Olaniyan , Morgan Eghosa
Published: March 2023

Trauma accounts for about 90% of spinal cord injuries worldwide. Traumatic spinal cord injury (TSCI) is recognized as a neurotrauma of global health priority due to the preventability of the injuries and the specialized and expensive medical and surgical care they necessitate. This study protocol guides the comprehensive and exhaustive review of the literature concerning the epidemiology, management and outcomes of TSCIs in Africa. This protocol follows the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols guidelines. The search strategy was performed primarily on PubMed and OVID Embase. A secondary literature search was carried out on African Journal Online and Google Scholar. All observational studies on the prevalence/incidence, presentation, management and outcomes of TSCIs in African countries were included. The following study types were excluded: literature reviews, meta-analyses, case reports, abstract-only articles, conference proceedings, randomized control trials and letters to the editor. Our outcomes include incidence of TSCIs in Africa, mechanisms of injury, different imaging and treatment modalities offered (e.g. conservative vs. operative intervention), clinical outcomes following TSCIs in Africa and challenges regarding the management of TSCIs in African surgical centres. This study aims to provide region-specific data that will guide and inform local practices regarding TSCIs. It will also map out areas that need more research and areas amenable to intervention by global health stakeholders.
Relative alignment between magnetic fields and molecular gas structure in molecular clouds
Authors: Mazzei Renato , Li Zhi-Yun , Chen Che-Yu , Fissel Laura , Chen Mike , Park James
Published: March 2023

We compare the structure of synthetic dust polarization with synthetic molecular line emission from radiative transfer calculations using a three-dimensional, turbulent collapsing-cloud magnetohydrodynamics simulation. The histogram of relative orientation (HRO) technique and the projected Rayleigh statistic (PRS) are considered. In our trans-Alfvénic (more strongly magnetized) simulation, there is a transition to perpendicular alignment at densities above ∼4 × 103 cm−3. This transition is recovered in most of our synthetic observations of optically thin molecular tracers; however, for 12CO it does not occur and the PRS remains in parallel alignment across the whole observer space. We calculate the physical depth of the optical depth τ = 1 surface and find that for 12CO it is largely located in front of the cloud mid-plane, suggesting that 12CO is too optically thick and instead mainly probes low-volume density gas. In our super-Alfvénic simulation, the magnetic field becomes significantly more tangled, and all observed tracers tend towards no preference for perpendicular or parallel alignment. An observable difference in alignment between optically thin and optically thick tracers may indicate the presence of a dynamically important magnetic field, though there is some degeneracy with viewing angle. We convolve our data with a Gaussian beam and compare it with HRO results of the Vela C molecular cloud. We find good agreement between these results and our sub-Alfvénic simulations when viewed with the magnetic field in the plane of the sky (especially when sensitivity limitations are considered), though the observations are also consistent with an intermediately inclined magnetic field.
Advection-dominated accretion flow for the varied transition luminosities in black hole X-ray binaries
Authors: Li Jiaqi , Qiao Erlin
Published: March 2023

Observationally, two main spectral states, i.e. the low/hard state and the high/soft state, are identified in black hole X-ray binaries (BH-XRBs). Meanwhile, the transitions between the two states are often observed. In this paper, we re-investigate the transition luminosities in the framework of the self-similar solution of the advection-dominated accretion flow (ADAF). Specifically, we search for the critical mass accretion rate $\dot{m}_{\rm crit}$ of ADAF for different radii r, respectively. It is found that $\dot{m}_{\rm crit}$ decreases with decreasing r. By testing the effects of BH mass m, the magnetic parameter β and the viscosity parameter α, it is found that only α has significant effects on $\dot{m}_{\rm crit}\text{--}r$ relation. We define the minimum $\dot{m}_{\rm crit}$ (roughly at the innermost stable circular orbit) as the hard-to-soft transition rate $\dot{m}_{\rm tr:H\text{--} S}$, above which BH will gradually transit from the low/hard state to the high/soft state, and $\dot{m}_{\rm crit}$ at 30 Schwarzschild radii as the soft-to-hard transition rate $\dot{m}_{\rm tr:S\rightarrow H}$, below which BH will gradually transit from the high/soft state to the low/hard state. We derive fitting formulae of $\dot{m}_{\rm tr:H\rightarrow S}$ and $\dot{m}_{\rm tr:S\rightarrow H}$ as functions of α, respectively. By comparing with observations, it is found that the mean value of α are α ∼ 0.85 and α ∼ 0.33 for the hard-to-soft transition and the soft-to-hard transition, respectively, which indicates that two classes of α are needed for explaining the hysteresis effect during the state transition. Finally, we argue that such a constrained α may provide valuable clues for further exploring the accretion physics in BH-XRBs.