bluuebunny/crossref_metadata_2025 huggingface dataset:
Development of cable-climbing robot with inspection function
Authors: Su B H , Chen Y H
Published: November 2024

The primary purpose of this study is to research and develop a crawler-type cable climbing robot to meet the demand of Sinotech Engineering Consultants, Ltd, using excellent structural design to meet the current practical requirements of the application of cable diameter varies greatly and simplify the operation process, improve the efficiency of the safety inspection of bridge cables and reduce the related risks, and through numerical analysis and the finite element method to optimize the design. The design is mainly divided into three parts: vibration measurement mechanism, robot control system, and cable climbing mechanism. The vibration measurement mechanism adopts the micro-vibration measurement method, in which a 3-axis piezoelectric accelerometer is tightly attached to the cable to measure the resonance frequency of the cable and detect the cable force. The robot control system adopts the fourth-generation Raspberry Pi as the central controller, with a ground remote control system and a backup system to prevent the robot from losing control due to the failure of the central system. The drive unit adopts a stepping motor with a planetary gearbox to drive the crawler. The cable-climbing mechanism uses a compression device to keep the robot’s track close to the cable to achieve a maximum speed of 0.04 m/s and to cross an obstacle limit of 9 mm over a 60-200 mm vertical or horizontal cable. The tracked cable-climbing robot is tested to be installed and operated by a single person and is adaptable to different cable environments with rapid deployment and operation.
Modelling and simulation of double-pantograph catenary system of Taiwan railway
Authors: Chuang Y J , Chen L K
Published: November 2024

In view of the insufficient transportation capacity of Taiwan Railways in populated urban areas and intercity railways, increasing the maximum operating speed can be a solution for the problem. However, it is unknown whether the overhead contact line (OCL) system of the Taiwan Railways can tolerate such speed changes. For the unique railway system used in Taiwan, the literature does not present research on the dynamic interaction behaviour for the typical EMU trains with two pantographs, which are widely used in Taiwan railway system. Further, in response to the government policy to localize the supply chain of railway components, this research aims to establish a reliable simulation model so that domestic manufacturers may use this model for the design and development of the pantograph-catenary system. In this study, the catenary system model is established based on theoretic principles, specifications and parameters are adapted from data used by Taiwan Railway Co. The pantograph model was constructed as multi-body model, with parameters taken from the pantograph equipped on the TEMU2000 tilting train. This model is used to analyse catenary system to investigate the potential loss of contact between the double pantographs and the contact wire with increased train speed. The loss of contact and other phenomena will be analysed to explore possible solutions or optimization strategies for catenary system design.
Development and application of software for designing axial fans in high-temperature environments
Authors: Zhang Shengli , Zeng Zhichun , Zhu Qianhui , Zhang Xinli , Wang Zhao , He Long , Ge Jian
Published: November 2024

This paper presents the development of software specifically designed for designing axial fans operating in high-temperature environments. The software’s accuracy and reliability are validated under extreme conditions. Key features of the software include adjustments for air physical properties, calculations for blade aerodynamic performance, and geometric dimension design. Through various design examples and experimental validation, the results indicate that the airflow error of the software under high-temperature conditions is 9.1%, while the total pressure error is 4.8%, demonstrating its high accuracy and reliability. Additionally, this paper proposes improvements to models of air physical properties, blade surface roughness, multi-condition simulations, and optimization algorithms to further enhance the software’s performance and applicability. The findings suggest that this design software holds significant application value in the field of high-temperature fan design.
Modeling and analysis of creep at elevated temperature analysis on thin-walled profile structures
Authors: Liu Jiexuan , Liu Yutong , Liu Xiao , Hui Yanchuan
Published: November 2024

High-strength steel plays a crucial role in aerospace because of its excellent performance. The high temperatures experienced during a spacecraft’s re-entry to Earth may result in creep in the steel, potentially leading to structural failure, so the finite element software is utilized in this paper to establish a calculation model and analyze the impact of temperature and fire duration on the creep strain of high-strength I-section steel beams under elevated temperatures. Among them, the high-temperature parameter significantly affects the creep strain variation of the mid-span element of the high-strength I-section steel beam. When the temperature parameter is increased by 100%, the maximum creep strain variation of the mid-span component of the beam will increase by about 24%. Under the exact increase, the maximum creep strain variation of the high-temperature duration parameter will only increase by about 3.78%; thus, when conducting a high-strength steel structure, fire resistance analysis should mainly consider the influence of temperature on its creep at elevated temperature strain.
Geometric nonlinear analysis of smart composite laminates
Authors: Zhu Hongyun
Published: November 2024

In order to create an adaptable system, active piezoelectric layers are fused or inserted into a host structure to create smart composite laminates (SCLs). SCL’s prospective applications in form modification, self-health sensing, and active vibration control demonstrate how important it is. In this paper, the static deformation characteristics and dynamic properties of SCL under voltage and mechanical loads are investigated. A completely coupled field program for SCL is constructed using Matlab. It describes mechanical displacements based on the shear deformation assumption and compares two displacement-strain models: linear and von K´arman nonlinear. The coupled nonlinear electromechanical equations are reduced to a finite element form that can be solved with convenience. Based on the program written, we have done a comparative study of linear and geometric nonlinearities of the SCL plate and also compared it with the existing articles. The results of the geometric nonlinear model of the SCL plate are quite different compared to linear and the nonlinear model results are more accurate.
Research on modeling method of providing oxygen functional architecture based on model
Authors: Yang Hao , Huang Renyu , Chen Dongsheng
Published: November 2024

The provision of oxygen is an important function of commercial aircraft, which is defined as providing the necessary oxygen for the safety of everyone on board, including crew oxygen, passenger oxygen, and portable oxygen. This article adopts SysML modelling language and proposes a model-based architecture modelling method for providing oxygen function for commercial aircraft. It transforms traditional experience and document-based system engineering work into functional architecture system engineering work, and utilises the correlation and traceability relationships of models to achieve state machine modelling for providing oxygen functional architecture. Through simulation verification, the functional architecture modelling method that provides oxygen can be effectively applied to the architecture of other systems.
Research on the ultra-high acceleration method based on dual-mass shock amplifier
Authors: Ren Zhiqiang , Li Xinming , Shen Zhiqiang , Yan Tingfei , Zhu Jianbin , Jin Zijian
Published: November 2024

Spacecraft are exposed to rigorous mechanical conditions throughout the launch, explosive decoupling, and landing stages. Electronic devices intended for space deployment are required to endure shock-induced reliability assessments. This study delves into the composition and operational principles of a high-g shock testing system. Furthermore, the paper derives a collision kinematics model from established classical collision dynamics and constructs analytical frameworks for both a single-degree-of-freedom and a two-degree-of-freedom spring-mass systems. Additionally, it investigates the principles of acceleration amplification. The finite element analysis model was computed, and its simulation outcomes were compared and contrasted with the data from shock experiments. The findings indicate that the finite element model is capable of accurately capturing the peak acceleration for both the drop table and DMSA table, with a discrepancy of no more than 5%. The acceleration of the amplifier is enhanced by approximately 40 times following the momentum exchange during the second collision. Moreover, the shock system, equipped with a dual mass shock amplifier (DMSA), is capable of producing accelerations exceeding 30,000G.
Fuselage panel structural-acoustic optimization design of civil aircraft based on numerical analysis
Authors: Zhou Hangwei
Published: November 2024

During the design process of civil aircraft, it is necessary to achieve a high level of cabin noise control to improve cabin comfort. In addition to controlling the intensity of the main noise sources that affect the acoustic environment in the cabin, the acoustic optimization design of the fuselage wall panel structure is also required. In this paper, acoustic analysis software ACTRAN is applied to study the acoustic characteristics of typical structures of civil aircraft cabins. Boundary conditions, material density, and material damping are analyzed from the following main aspects: fuselage panels, thickness, density, reinforced frame design, etc., to study the acoustic barrier performance of typical fuselage panel structures, put forward design suggestions for fuselage panels, and guide the acoustic optimization design of civil aircraft structures.
Thermal design of a frequency hopping processor
Authors: Liang Dapeng , Wang Sheng , Wang Siqi , Zhang Li , Li Dan , Hu Fengjiao
Published: November 2024

To solve the difficult problems in the thermal design of a new frequency-hopping processor, such as high heat consumption, concentrated local heat flux of the device, and large thermal resistance, a thermal design scheme was proposed to optimize the structure design and enhance the thermal conductivity of PCB board. At the same time, a combined scheme of copper water heat pipe-thermal expansion plate was used. Flotherm was used for thermal simulation and a thermal balance experiment under vacuum conditions was designed. Then the temperature of the frequency-hopping processor was measured experimentally to further verify the rationality of the design scheme. The combined scheme of copper water heat pipe-thermal expansion plate will guide the thermal design of this type of frequency hopping processor.
Experimental study of polyurethane rubber with half-sine waveform generator
Authors: Jin Zijian , Shen Zhiqiang , Yan Tingfei , Li Xinming , Liu Chuang , Ren Zhiqiang
Published: November 2024

Impact mechanics environmental testing technology is booming. Polyurethane rubber, as a typical semi-sinusoidal waveform generator, is particularly important to understand its stiffness performance. This paper presents an experimental investigation utilizing a pneumatic impact testing machine to evaluate the performance of polyurethane rubber waveform generators, varying in both hardness and height. By recording their compression under varying impact pressures, as well as the rebound height of the table and the corresponding velocity changes, we observed that the data generated by the 60mm thick waveform generator exhibited greater regularity. Notably, these data adhered to the principle that increased hardness correlates with decreased compression and reduced rebound height of the table. Additionally, we successfully designed an initial prototype of a rebound collision acceleration amplifier, which, under an impact pressure of merely 0.038MPa, achieved an impressive impact acceleration of nearly 2700g, accompanied by a smoother half-sine waveform curve.
Fuze vibration reduction design based on high-speed rocket sled vibration effect
Authors: Yan Lide , Cao Lifei , Duan Xiaochang , Wu Qi , Hou Lei , Xue Yubo
Published: November 2024

Rocket sled is one of the important methods to realize the performance test in fields such as aerospace and weapon equipment. In response to the extremely high overload phenomenon of the tested fuze system in rocket sled impact tests, this paper proposes a new method of fuze vibration reduction. By optimizing the layout and multi-layer potting of fuze shell and internal components, the influence of vibration effects on electronic components is effectively reduced. Comparative analysis of results is based on epoxy resin sealant potting, silicone rubber potting, or without additional protection, to further improve the safety and service life of internal key components and provide necessary structural reference for vibration reduction treatment in rocket sled tests.
Performance analysis of air-cooled turbine based on source terms method
Authors: Hao Ning , Yi Weilin
Published: November 2024

Investigating turbine blade cooling and blade tip clearance leakage is crucial for reducing turbine losses and enhancing overall engine performance. Therefore, this paper uses the E3 two-stage high-pressure turbine as a case and employs the source term method to model the film cooling configuration, validating its efficacy and examining the performance parameters and flow field characteristics of air-cooled turbines under varying blade tip clearances. The outcomes demonstrate that the source term approach accurately forecasts the comprehensive performance parameters of air-cooled turbines, with blade tip clearance height predominantly impacting turbine performance in high-velocity regions. For small blade tip clearance, air-cooled turbines exhibit diminished efficiency with a decreasing expansion ratio in high-velocity regions, but they demonstrate an inverse behavior in low-velocity regions. Conversely, under conditions of larger blade tip clearances, the cooling effectiveness of air-cooled turbines is more pronounced in regions characterized by low expansion ratios and low speeds.
Research on the influence of out-of-plane loads on the fatigue life of metal structures
Authors: Wang Qianqian , Huang Fu
Published: November 2024

For civil aircraft structures, in-plane tensile, compressive, shear, and their combined forms of loads are the usual loads on plate and shell structures, while bending moments, torsion, and other forms of loads are mainly borne by assemblies consisting of multiple parts. However, some plate and shell structures are subjected to in-plane loads while also being affected by out-of-plane loads. In order to study the difference between the fatigue performance of plate and shell structures under the influence of out-of-plane load and the fatigue performance under the effect of pure in-plane load, the axial tensile fatigue test considering the out-of-plane load is carried out, which demonstrates the negative effect of the out-of-plane load on the axial tensile fatigue strength of the structure. At the same time, a new structural fatigue life prediction method considering out-of-plane loads is established by combining finite element analysis, which can more accurately predict the structural fatigue life under the influence of out-of-plane loads and provide support for metal structure fatigue analysis.
Study of three-dimensional crack extension in turbine discs of short-life turbojet engines
Authors: Huang Yang , Huang Hui , Xiong Jie
Published: November 2024

A simulation study on the 3D crack extension of short-lived turbojet engine turbine discs was carried out using FRANC3D 3D fracture mechanics software combined with ABAQUS finite element software. By establishing a 3D geometric model of the turbine disc, the crack extension process is simulated by using the sub-model method, and the crack extension behavior and failure mode are analyzed to predict the remaining life of the cracked wheel disc. The results show that the crack expansion path matches well with the crack failure phenomenon of the turbine disc under the actual working conditions; the turbine disc crack is dominated by Type I (open Type) crack expansion, and the stress intensity factors of Type II and Type III are negligible; the crack expansion rate increases slowly with the increase of crack depth, and it rises steeply at the critical value of the fracture failure; and the residual life of the turbine disc is 32 cycles. This study provides empirical analyses for crack monitoring and life prediction of turbine discs and is of great significance for engine maintenance and reduction of end-of-life costs of turbine components.
Prediction of aircraft fuel consumption based on machine learning algorithm
Authors: Fang Shengyou , Qu Cheng , Liu Tao
Published: November 2024

The shortcomings of traditional aircraft fuel consumption calculation methods include insufficient theoretical analysis, complex input parameters, and poor calculation accuracy. Through the analysis of aircraft motion equations and engine working characteristics, this paper screens out the key parameters affecting aircraft fuel consumption. Based on the real flight data, three machine learning methods, BP neural network, RBF neural network, and Support Vector Machine(SVM), are used for training, and a fuel consumption prediction model is established with key parameters as inputs. The prediction accuracy and characteristics of the three models are analyzed and compared. The aircraft fuel consumption prediction model achieves the operational requirements, and the accuracy in the flight profile reaches 5%. The trained model was applied to the planning of the transport aircraft mission profile, achieving a fuel consumption error of only 1.1% across the entire mission profile, resulting in a relatively accurate outcome.
Analysis of factors affecting the stability of aircraft engine test
Authors: Shen Yifan , Luo Tingfang
Published: November 2024

Although the aircraft is in a braking and shutdown state during engine testing, there may still be situations where the aircraft slides or deviates during the development process, which affects the safety of the aircraft. This article establishes a force analysis model for an aircraft engine test and proposes a single-engine testing force analysis method based on dual-engine testing force analysis. Factors such as the friction coefficient of pavement, wind speed, and aircraft parking slope are taken into account in the calculation. The relationship between different influencing factors and ground stability is studied in the article. The article provides a reference for the weight center of gravity limitation of aircraft under engine ground testing conditions.
Experimental study on fireproof of aviation lubrication oil tank
Authors: Wu Bin , Zeng Tai , Li Songyang , Su Zhengliang , Xie Fei
Published: November 2024

This paper presents an experimental study on the fireproof performance of aeroengine lubrication oil tanks. By constructing a simplified lubrication oil tank model and simulating the harsh operating conditions of engine fires, the oil tank was exposed to flames generated by a standard burner for testing. The study monitored and recorded key parameters such as temperature, pressure, flow rate, and phase changes within the tank. The results indicate significant differences in the temperature distribution characteristics of the tank walls under different inlet temperatures and flow conditions. In the rigorous 15-minute flame test, all tests successfully completed the fire verification process.
Modeling of the leader-follower satellite formation for long baseline
Authors: Wu Jun , Wang Wenyan , Wan Bei
Published: November 2024

Interferometric Synthetic Aperture Radar (InSAR) represents a crucial component of synthetic aperture radar technologies, with the accuracy of measurements significantly improving as the baseline length increases. In comparison with the traditional Hill-Clohessy-Wiltshire (HCW) equations, the application of curvilinear coordinate systems for modeling satellite formations in circular orbits has demonstrated enhanced precision, especially when the formations span larger distances. However, these improvements were initially limited to circular orbits. Addressing this limitation, this study introduces a novel approach by incorporating elliptical orbits into the model, thereby refining the state transition matrix through the incorporation of eccentricity factors and maintaining the direct correlation with the temporal dynamics of satellite motion in three dimensions. Through rigorous numerical simulations, it has been established that this refined model substantially improves accuracy in leader-follower satellite formations.
Insight HXMT and GECAM joint observation of time domain astronomy from cosmic outbursts
Authors: Huang Xinyue
Published: November 2024

The field of time-domain astronomy focuses on the observation of temporal variations in celestial phenomena, in particular gamma-ray bursts (GRBs). It emphasized the importance of monitoring transient events and phenomena, which occurred on different time scales, ranging from milliseconds to years. This paper also explained the properties of X-rays and Gamma-rays, their sources and the significance of studying them for understanding the dynamic nature of the universe. The collaboration between the Insight HXMT and GECAM missions was designed to detect and study high-energy astronomical events, such as those associated with black holes and neutron stars, and to provide for rapid data transmission and dissemination of astronomical alerts. By combining observations from the two instruments, researchers can gain a more comprehensive understanding of cosmic phenomena and explore the fundamental physics of the universe.
Experimental study on thermally induced vibration of flexible solar cell wing simulator
Authors: Bi Yanqiang , Gao Wen , Fan Chao , Xiang Zhihai , Du Chunlin
Published: November 2024

With the development of large spacecraft and satellite payloads, the power supply required is increasing, especially in space solar power stations, and the large flexible solar wing is an inevitable trend in the future. Due to their light weight and large area, flexible solar wings may face thermally induced vibration during orbit operation, which will lead to the degradation of spacecraft performance and even structural damage. In this paper, the test method of a flexible solar wing simulator is established, and the thermally induced vibration test of a flexible solar cell wing simulator is carried out. And vibration amplitude value is 25 and 9 microns with a frequency 0.56Hz.The characteristic of thermally induced vibration of flexible solar cell wing is given, which provides a basis for its thermally induced vibration suppression.
Trajectory reconstruction method for spacecraft formation considering collision probability constraints
Authors: Wang Bochuan , Wang Xiaohui , Liu Jiancen , Jin Xiangyu , Tang Yinglong
Published: November 2024

This paper introduces a trajectory reconstruction algorithm for spacecraft formation, combining collision probability and sequential convex programming algorithms. When reconstructing the trajectory of spacecraft formation, external collision avoidance constraint is added to avoid collision threats from space objects. The constraint accuracy of the external collision avoidance constraints of the BOX method and the collision probability method is analyzed. The simulation results indicate that the collision probability method has higher accuracy compared to the BOX method. It addresses the issue of inaccurate division of collision avoidance zones in the BOX method, which tends to be aggressive in the velocity direction and conservative in other directions. A reference is provided for trajectory reconstruction when formation satellites encounter non-cooperative targets.
Imaging simulation analysis of space targets by different observed orbits
Authors: Xu Yantong , Tao Dongxing , Liu Xiaoning , Wang Jiulong , Bi Yanqiang , Zhang Guang , Lin Boying , Li Xiyuan , Li Qing , Wan Dongmei
Published: November 2024

For most optical simulations of space targets, static imaging characteristics are studied with a pre-set angle and attitude which are less consistent with the actual situation for satellite detectors’ dynamic image. Especially when the detector and the target are in different orbits, the imaging angles and attitudes also vary. In this article, two kinds of observed orbits are selected to simulate the detector image results, and the observed attitude and angle are updated over time through the simulation process. Furthermore, a temperature field of the space target is also calculated as preconditioned data to be taken into account in the optical simulation, instead of roughly estimating the temperature. The result of the study reveals that when the satellite detector and target operate at coplanar orbits, closer distances (ranging from 236 km to 28 km) allow for the acquisition of more specific details regarding the target’s characteristics. This research may offer a new approach to selecting orbits to obtain high-quality imaging data.
Free vibration analysis of rectangular plates resting on an elastic foundation
Authors: Li Gen
Published: November 2024

Rectangular plate on elastic foundations is a common structural form in aerospace fields, while there still lacks a general analytical method for free vibration analysis of this kind of structure. Thus, the extended separation-of-variable method is used to obtain the analytical free vibration solutions for plates with all kinds of homogeneous boundary conditions. The mode functions are assumed to be in separation-of-variable form, and the natural frequencies of two-direction mode functions are mathematically independent. Then, the free vibration solutions are obtained according to the two-direction boundary conditions. The correctness of the present results is verified via numerical comparisons. Parameter study shows that the elastic foundation significantly affects the flexural vibration behaviors of rectangular plates, and the influence is dependent on boundary conditions and mode orders of rectangular plates.
Modeling and analysis of tethered satellite systems based on spinning deployment
Authors: Liu Guotong , Fan Fengchen , Miao Yuanqing , Zhang Tianyu , Bian Yushu
Published: November 2024

In recent years, with space science and technology development, tethered satellites have been widely recognized and valued. This paper analyzes a tether satellite system based on spinning deployment by dynamic modeling and numerical simulation to analyze the factors affecting its deployment stability. Firstly, the dynamic model of the tethered satellite system under the action of spinning centrifugal force is established using the dumbbell model. Then, numerical simulation is conducted to study the factors affecting the deployment stability of the tethered satellite system. Finally, a feasible and stable deployment control method is proposed based on actual working conditions.
Molecular dynamics simulation of particle radiation damage processes in ZnO crystals
Authors: Yu Lantao , Fan Chao , Gao Qingzhe , Lv Liangxing
Published: November 2024

The cascade collision process in ZnO crystal caused by Primary Knocked Atom (PKA) under different incident conditions has been simulated by the Molecular Dynamics (MD) method. Simulation results show that the incident depth is smaller than 20 atomic layers for PKAs with initial kinetic energy less than 2 keV, and more than 30 atomic layers for PKAs with energy larger than 5 keV. For PKAs with lower energy, the defects are mainly distributed near the incident trajectory, and the distribution range of defects becomes wider with the increase of PKA energy. When the PKA energy is less than 10 keV, the number of defects will reach the peak within 1 ps, and then the system enters into the annihilation process and reaches to steady state within 20 ps. In addition to the incident energy, the incident direction of PKA also has a great influence on the cascade collision process and defect distribution. Compared with two other cases, <111> direction and <001> direction, PKAs along <011> direction produces significantly more defects, with a distribution more concentrated, and the defect recombination rate is also higher in the annihilation process. The evolution of different types of defects in the cascade collision process is different, and the number of O vacancies is the largest, followed by the number of O interstitial atoms, Zn interstitial atoms, and Zn vacancies. Some of the interstitial O atoms replace the Zn vacancies during the annihilation process.
Dynamic modeling and ground verification of space flexible net deployment
Authors: Liu Zhiyang , Yang Yueneng , Feng Haoqing , Zhang Shifeng
Published: November 2024

This article presents a modeling and simulation method to simulate the deployment process of a space net. The space net is simplified into a spring-damping model using the finite element method, and a dynamic model of the process is established. The configuration of the net and the variation of internal forces during the ejection and deployment process are analyzed through simulation calculations. In addition, ground experiments were conducted and compared with simulation results. By calculating the effective deployment area during the flight of the net, the reliability of the model and the feasibility of capturing the target are verified.
The impact of roughness on the resistance of full-scale ships
Authors: Yin Anpeng , Zeng Xiangming
Published: November 2024

This study aims to explore the impact of hull roughness on ship resistance, which provides a reference for enhancing the operational efficiency and energy-saving levels of ships. Initially, the development and accuracy of Computational Fluid Dynamics (CFD) numerical simulations are elucidated through literature, and the current state of research on hull roughness by scholars both domestically and internationally is introduced. Subsequently, taking the 2000 TEU container ship SITCCAGAYAN as the object of study, a CFD simulation is performed based on the unsteady Reynolds-averaged Navier-Stokes equations in Star CCM+ software. An improved wall function method and roughness function are used to design the simulation experiments, conducting the resistance prediction under various conditions, including the fully smooth hull, fully rough hull, and different levels of roughness at various parts of the hull. The experiment, based on results such as the increase in resistance, roughness impact factor, and roughness Reynolds number, demonstrates that the surface roughness of the hull significantly affects the magnitude of ship resistance. An increase in local and overall roughness leads to an increase in total resistance, but the roughness at the bow part of the ship has the greatest impact on resistance.
Luigi Pasinetti: an appreciation
Authors: Milgate Murray , Eatwell John , de Vivo Giancarlo
Published: November 2024

This article presents an appreciation of the lifetime contributions of Luigi Pasinetti to economics. In a career spanning 70 years, Pasinetti operated at the frontiers of economic theory and analysis. The article covers his contributions to the economics of growth, distribution, capital, structural change, production and fiscal policy. It also provides an account of his intellectual formation and a checklist of his published works.
Factors impacting vaccine uptake among adult Medicaid beneficiaries: a systematic literature review
Authors: Moss Emily , Eiden Amanda L , Hartley Louise , Carrico Justin , Farkouh Raymond , Poston Sara , Gabriel Meghan , Golden Anna Hundt , Bhatti Alexandra
Published: November 2024

Vaccine uptake is suboptimal among adult Medicaid beneficiaries. To evaluate factors affecting vaccine uptake among adult Medicaid beneficiaries and/or affecting healthcare providers who vaccinate adult Medicaid beneficiaries, we conducted a systematic literature review in Embase, Medline, Database of Abstracts of Reviews of Effects, and the Cochrane Library for articles published from January 2005 through July 2022 and relevant conferences. For included studies, data were extracted on the study characteristics, patient and provider cost barriers, patient and provider perceived risks/benefits, and other barriers faced by patients and providers. Quality assessments were conducted using a checklist from the Joanna Briggs Institute. Twenty-one studies analyzed patient-related factors (14 studies) and/or provider-related factors (8 studies). Reviewed studies indicate that vaccine uptake is influenced by insurance benefit and cost-coverage policies, including cost-sharing, access to vaccination services, and vaccine education and awareness. Financial factors, including reimbursement for vaccine acquisition and administration, influence providers' vaccination practices for Medicaid beneficiaries. Our findings suggest that reducing or eliminating vaccination cost-sharing, promoting vaccine education and awareness about the importance and safety of vaccines, increasing access, and exploring reimbursement rates equivalent with other public or private insurance plans could mitigate barriers to vaccination for the adult Medicaid population.
Risk Factors and Management of Portal Vein Thrombosis after Hepatectomy: A Single-Center Experience
Authors: Wakizaka Kazuki , Shichi Shunsuke , Aiyama Takeshi , Asahi Yoh , Nagatsu Akihisa , Orimo Tatsuya , Kakisaka Tatsuhiko , Taketomi Akinobu
Published: November 2024

Objective:

This study investigated the risk factors and management of portal vein thrombosis (PVT) after hepatectomy.

Background:

PVT after hepatectomy can cause liver dysfunction and portal hypertension, and may be fatal. However, it has not been sufficiently investigated.

Methods:

The study included 1403 consecutive patients who underwent elective hepatectomy at our department from January 2010 to July 2022. The patients were divided into PVT and non-PVT groups based on the presence or absence of PVT, and relevant risk factors were analyzed. The management and prognosis of patients with PVT were investigated.

Results:

Among the 1403 patients, PVT occurred in 33 cases, giving a frequency of 2.4%. In univariate analyses, female sex (P = 0.03), portal vein reconstruction (P = 0.01), and left lateral sectionectomy (P < 0.001) were significant risk factors for PVT. On multivariate analysis, portal vein reconstruction (P = 0.01) and left lateral segmentectomy (P < 0.001) remained significant risk factors for PVT. The management options for PVT were thrombectomy, antithrombotic therapy, and observation. With antithrombotic therapy, 96.4% of patients achieved PVT resolution. Among patients who underwent hepatectomy with portal vein reconstruction, the PVT site was the main trunk of the portal vein in all 3 cases, and thrombectomy was performed in 2 cases. No perioperative mortality was observed.

Conclusions:

In the present study, portal vein reconstruction and left lateral sectionectomy were identified as risk factors for PVT after hepatectomy. As PVT can be fatal, early detection and appropriate treatment according to the status of PVT are important.
A Pilot Randomized Controlled Study to Determine the Effect of Real-Time Videos With Smart Glass on the Performance of the Cardiopulmonary Resuscitation
Authors: Kebapci Ayda , Ozkaynak Mustafa , Bowler Fara , Ponicsan Heather , Zhang Zhan , Bai Enze
Published: November 2024

The aim of this study was to determine the effect of real-time videos with smart glasses on the performance of cardiopulmonary resuscitation performed by nursing students. In this randomized controlled pilot study, the students were randomly assigned to the smart glass group (n = 12) or control group (n = 8). Each student's cardiopulmonary resuscitation performance was evaluated by determining sequential steps in the American Heart Association algorithm they applied and the accuracy and time of each step. A higher number of participants correctly checked response breathing, requested a defibrillator, activated the emergency response team, and provided appropriate chest compressions and breaths in the smart glass group than the control group. There were significant differences between groups. Furthermore, more participants significantly corrected chest compression rate and depth and hand location, used a defibrillator, and sustained cardiopulmonary resuscitation until the emergency response team arrived in the smart glass group than in the control group. Additionally, a significantly shorter time was observed in the smart glass group than in the control group in all variables except time to activate the emergency response team (P < .05). Remote expert assistance with smart glass technology during cardiopulmonary resuscitation is promising. Smart glass led to a significantly better ABC (airway, breathing, circulation) approach, chest compression depth and rate, and hand position. Furthermore, remote expert assistance with smart glass has the potential to improve overall resuscitation performance because it enabled students to initiate resuscitation, use a defibrillator, and defibrillate patients earlier. Nurses may benefit from smart glass technology in real life to provide effective cardiopulmonary resuscitation.
Advancing research on greenspace and climate-sensitive adverse birth outcomes for equity and impact
Authors: Siddika Nazeeba , Gronlund Carina J. , Handal Alexis J. , O’Neill Marie S.
Published: November 2024

Environmental epidemiologists are increasingly evaluating whether and how human exposure to vegetation (greenspace) can benefit health. Relatedly, scientists and policymakers have highlighted the need to integrate efforts to address the dual crises of accelerating climate change and rapid loss of biodiversity, including nature-based solutions. Greenspace is one solution that can protect humans from climate-related exposures, including heat, air pollution, and flooding. However, most environmental epidemiology research on greenspace occurs in high-income countries, and adverse birth outcomes, previously associated with greenspace, disproportionately occur in low- and middle-income countries (LMICs). Although epidemiology research using existing survey or administrative data and satellite imagery is important for documenting broad patterns, such research is lacking in LMICs. Further, complementary, community-engaged research to inform interventions and policies is needed so that nature-based solutions with co-benefits for climate mitigation and health are adopted effectively and equitably. We provide suggestions for future research that would increase impact and call for better representation of LMICs and vulnerable communities within high-income countries in research and action on greenspace and climate-sensitive birth outcomes.
Key Genes and Biological Pathways in Pulmonary Arterial Hypertension Related to Endoplasmic Reticulum Stress Identified by Bioinformatics
Authors: Wang Shanzuan , Zhuo Debin , Lin Juan , Zhang Chunxia
Published: November 2024

Pulmonary arterial hypertension (PAH) is a cardiopulmonary vascular condition with an unclear pathogenesis. Targeting endoplasmic reticulum (ER) stress has been suggested as a novel treatment approach for PAH, but the mechanisms involving ER stress–related genes in PAH are not well understood. Microarray data for PAH and ER stress–related genes were analyzed. Differential and Venn analyses identified 17 differentially expressed ER stress–related genes in PAH. Candidate drugs targeting these genes were predicted using the CMap database. A protein–protein interaction (PPI) network was constructed, and hub genes (LCN2, IGF1, VCAM1, EDN1, HMOX1, TLR4) with complex interplays were identified using the STRING database and Cytoscape plugins. The clinical diagnostic performance of the hub genes was evaluated using ROC curves. The GeneMANIA Web site was utilized to predict enriched pathways associated with the hub genes and their functionally similar genes. MiRNAs and transcription factors targeting the hub genes were predicted using the Networkanalyst Web site. The immune levels in control samples and PAH samples were assessed using various algorithms. Nine drug candidates were found to potentially target the identified ER stress–related genes. The hub genes and their correlated genes were significantly enriched in immune-related pathways. The PAH group showed increased immune cell infiltration, indicating a heightened immune response. This study sheds light on the role of ER stress–associated hub genes in PAH and proposes potential drugs targeting these genes. These findings provide valuable insights into PAH mechanisms and support the exploration of ER stress as a therapeutic target.
Insomnia and Chronic Pain Mediate the Relationship Between Traumatic Brain Injury and Reduced Positive Airway Pressure Adherence Among Veterans
Authors: Kinney Adam R. , Schneider Alexandra L. , Welsh Carolyn , Sarmiento Kathleen F. , Ulmer Christi S. , Forster Jeri E. , Abbott Zachary , Bahraini Nazanin H.
Published: November 2024

Objective:

To examine whether co-morbid insomnia, post-traumatic stress disorder (PTSD), depression, and chronic pain mediate the relationship between traumatic brain injury (TBI) and positive airway pressure (PAP) treatment adherence.

Setting:

One Veterans Health Administration (VHA) sleep medicine site.

Participants:

Veterans (n = 8836) who were prescribed a modem-enabled PAP device.

Design:

Secondary analysis of clinical data. We used path analysis to examine: (1) whether Veterans with a history of TBI were more likely to experience insomnia, PTSD, depression, and chronic pain; (2) in turn, whether Veterans with these co-morbid conditions exhibited lesser PAP adherence; and (3) whether Veterans with a history of TBI will exhibit lesser PAP adherence, even while accounting for such co-morbid conditions. Model estimates were adjusted for sociodemographic (eg, race/ethnicity) and clinical characteristics (eg, mask leakage).

Main Measures:

Health conditions were abstracted from the VHA medical record. PAP adherence was measured using average nightly use (hours).

Results:

Among 8836 Veterans, 12% had a history of TBI. TBI history was not associated with PAP adherence when accounting for the presence of insomnia, PTSD, depression, and chronic pain. Indirect effect estimates indicated that a history of mild, moderate-severe, or unclassified TBI was associated with lesser PAP adherence, as mediated by the presence of co-morbid insomnia and chronic pain. Generally, TBI was associated with an increased likelihood of co-morbid insomnia, PTSD, depression, and chronic pain. In turn, insomnia and chronic pain, but not PTSD or depression, were associated with lesser PAP adherence.

Conclusions:

Our study offers empirical support for insomnia and chronic pain as potential explanatory mechanisms underlying the relationship between TBI history and suboptimal PAP adherence. While additional research is needed to confirm causality, findings offer preliminary evidence that can inform the development of tailored PAP adherence interventions for Veterans with TBI and obstructive sleep apnea.
EARLY SILICONE OIL OPACIFICATION IN THE ABSENCE OF EMULSIFICATION IS CAUSED BY AN INCREASED LEVEL OF SILICONE DIOXIDE
Authors: Hammer Maximilian , Britz Leoni , Böhmann Manuel Ben , Herbster Lorenz , Muuss Marcel , Herth Jonathan , Cionoiu Sebastian , Krisp Holger , Spitzer Martin Stephan , Wohlfart Sabrina , Uhl Philipp , Auffarth Gerd Uwe
Published: November 2024

Background/Purpose:

In October 2023, other cases with early silicone oil opacification within hours after intraocular implantation in the absence of emulsification occurred. Although multiple, small series of this phenomenon are now documented during the past decade, the cause was never unmasked. In this study, we analyzed explanted patient samples, unused samples of the affected, and a control batch of the same silicone oil.

Methods:

The oils were examined on their optical and viscosimetric properties, interfacial tension, and for the presence of particles. Contamination was investigated using inductively coupled plasma mass spectrometry, thermogravimetric analyses, and Raman spectroscopy. Cytotoxicity examination in ARPE-19 cells was performed. The oil's effect on pH changes of aqueous solutions and the oil's defoaming ability were analyzed.

Results:

The affected batch passed all regulatory limits. However, the affected batch showed an elevated turbidity already before implantation. Three thousand–fold magnification revealed dispersed particles only in the affected batch. Contamination analyses revealed the absence of other elements, indicating a silicon-containing contamination. The affected batch showed no in vitro cytotoxicity but altered viscosimetric properties and a lower pH of the hydrophilic phase after inducing emulsification. Both batches did not show relevant defoaming properties.

Conclusion:

The results obtained combined with information from suppliers and the manufacturer suggest an elevated level of silica particles as the cause of the opacification. Based on these results, the manufacturer and suppliers of the latest affected batch adjusted cutoff values for turbidity measurements and introduced turbidity measurements of the raw material before distillation. Other manufacturers should follow these preventive measures.
Burnout and Turnover Among Veterans Health Administration Primary Care Providers From Fiscal Years 2017–2021
Authors: Apaydin Eric A. , Yoo Caroline K. , Stockdale Susan E. , Jackson Nicholas J. , Yano Elizabeth M. , Nelson Karin M. , Mohr David C. , Rose Danielle E.
Published: November 2024

Objectives:

We examined how individual-level turnover among Veterans Health Administration primary care providers (PCPs) from fiscal years 2017 to 2021 was associated with health care system-level burnout and turnover intent.

Background:

Burnout among PCPs has been well documented in recent studies, but less is known about the potential relationship between burnout and turnover.

Methods:

We identified a national cohort of 6444 PCPs (physicians, nurse practitioners, and physician assistants) in 129 Veterans Health Administration health care systems in the first quarter of fiscal year 2017 and tracked their employment status for 20 quarters. PCP employment data on turnover were linked to annual health care system-level employee survey data on burnout, turnover intent, and other covariates. We performed logistic regression to estimate the impact of health care system-level burnout and turnover intent on individual PCP turnover, controlling for individual and health care system-level covariates and adjusting for clustering at the health care system level.

Results:

Median health care system-level burnout ranged from 42.5% to 52.0% annually, and turnover among PCPs ranged from 6.3% to 8.4% (mean = 7.0%; SD = 0.9%). Separation from employment was higher among employees at health care systems with the highest burnout (odds ratio =1.14; 95% CI = 1.01–1.29) and turnover intent (OR = 1.18; 95% CI = 1.03–1.35).

Conclusions:

PCPs in health care systems with high burnout are more likely to separate from employment. Policymakers and administrators seeking to improve retention should consider system-level interventions to address organizational drivers of burnout.