bluuebunny/crossref_metadata_2025 huggingface dataset:
Review of the Hydrogen Permeation Test of the Polymer Liner Material of Type IV On-Board Hydrogen Storage Cylinders
Authors: Li Xiang , Huang Qianghua , Liu Yitao , Zhao Baodi , Li Jiepu
Published: July 2023

Type IV hydrogen storage cylinders comprise a polymer liner and offer advantages such as lightweight construction, high hydrogen storage density, and good fatigue performance. However, they are also characterized by higher hydrogen permeability. Consequently, it is crucial for the polymer liner material to exhibit excellent resistance to hydrogen permeation. International organizations have established relevant standards mandating hydrogen permeation tests for the liner material of type IV on-board hydrogen storage cylinders. This paper provides a comprehensive review of existing research on hydrogen permeability and the hydrogen permeation test methods for the polymer liner material of type IV on-board hydrogen storage cylinders. By delving into the hydrogen permeation mechanism, a better understanding can be gained, offering valuable references for subsequent researchers in this field. This paper starts by thoroughly discussing the hydrogen permeation mechanism of the liner material. It then proceeds to compare and analyze the hydrogen permeation test methods specified by various standards. These comparisons encompass sample preparation, sample pretreatment, test device, test temperature and pressure, and qualification indicators. Then, this study offers recommendations aimed at enhancing the hydrogen permeation test method for the liner material. Additionally, the influence of test temperature, test pressure, and polymer material properties on the hydrogen permeability of the liner material is discussed. Finally, the influences of the test temperature, test pressure, and polymer material properties on the hydrogen permeability of the liner material are discussed. Future research direction on the hydrogen permeability and hydrogen permeation test method of the liner material of the type IV hydrogen storage cylinder has been prospected.
Investigation of the Cutting Fluid Incidence Angle Direction in Turning Grade 5 ELI Titanium Alloy under High-Pressure Cooling Conditions
Authors: Struzikiewicz Grzegorz
Published: July 2023

The use of high-pressure cooling (HPC) in machining can increase the efficiency and improve process stability through more effective breaking and chip evacuation. Turning tests of the Grade 5 ELI titanium alloy were carried out using cemented carbide tools and taking into account the direction of feeding of the cutting liquid. Measurements of the components of the total cutting force were carried out for feeds in the range f = <0.08; 0.13> mm/rev and two angular settings (i.e., angle α = <30°; 90°> and β = <0°; 60°>) of the nozzle. The chip breakage coefficient was determined. It was shown that the cutting force values depended on the feed value, and the angle of feeding of the cutting fluid did not significantly affect the values of the cutting forces. Despite the different forms of chips obtained, the applied method of searching for the best conditions was unsuccessful and no significant effect on the values of the chip breaking coefficient Cch was observed. To determine the best nozzle setting, it is useful to determine the working area of the chip breaker. Due to the shape of the chip, the optimal angular setting for the nozzle that supplied the cutting fluid was α = 60° and β = 30°. In addition, it was observed that the angle of incidence of the cutting fluid jet could affect the chip formation process and support the chip cracking process.
Argon Plasma Treatment Effects on the Micro-Shear Bond Strength of Lithium Disilicate with Dental Resin Cements
Authors: Liao Yixuan , Lombardo Stephen J. , Yu Qingsong
Published: July 2023

The low bond strength of lithium disilicate (LD) ceramics to dental resin cements remains a critical issue for dental applications because it leads to frequent replacement and causes tooth tissue destruction and consumption. The objective of this study was to examine the effects of atmospheric non-thermal argon plasma (NTP) treatment on LD to improve its micro-shear bond strength (μSBS) with dental resin cements because LD mostly experiences shear stress for its commonly used dental applications as crowns or veneers. Argon plasma treatment was performed on hydrofluoric (HF) acid-etched LD surfaces, and then commercial resin cements were subsequently applied to the treated LD surfaces. The plasma treatment significantly reduced the water contact angle of the LD surface to less than 10° without changing the surface morphology. The μSBS test was performed with cement-bonded LD samples after 24 h and 30 days, as well as after 1000 cycles of thermal cycling. The test results show that, as compared with the untreated controls, 300 s of plasma treatment significantly improved the LD-resin cement bond strength by 59.1%. After 30 days of storage in DI water and 1000 cycles of thermal cycling, the plasma-treated LD samples show 84.2% and 44.8% higher bond strengths as compared to the control samples, respectively. The plasma treatment effect on LD surfaces diminished rapidly as the bond strength decreased to 25.5 MPa after aging in the air for 1 day prior to primer and cement application, suggesting that primers should be applied to the LD surfaces immediately after the plasma treatment. These results demonstrate that, when applied with caution, plasma treatment can activate LD surfaces and significantly improve the SBS of LD with dental resin cements in both short-term and long-term periods.
Hierarchical Zeolites Containing Vanadium or Tantalum and Their Application in Cyclohexene Epoxidation Reaction
Authors: Szczyglewska Paulina , Feliczak-Guzik Agnieszka , Chałupniczak Sylwia , Nowak Izabela
Published: July 2023

The aim of this study was the synthesis, characterization, and catalytic application of new hierarchical materials modified with tantalum and vanadium ions. These materials exhibit secondary porosity, thus allowing the reactant molecules to access the active sites of the material while maintaining the acidity and crystallinity of the zeolites. Based on the results, these systems were found to be highly active and selective in the oxidation of cyclohexene. The performance of the catalysts was compared in oxidation processes carried out by conventional and microwave-assisted methods. Microwave-assisted experiments showed that in the presence of a hierarchical FAU zeolite containing Ta, long reaction times could be shortened with increased activity and selectivity under the same residual experimental conditions.
A Constitutive Model for Describing the Tensile Response of Woven Polyethylene Terephthalate Geogrids after Damage
Authors: Lombardi Giovani , Pinho-Lopes Margarida , Paula António Miguel , Pereira António Bastos
Published: July 2023

A constitutive model was used to describe the tensile response of two woven Polyethylene Terephthalate (PET) geogrids, before and after mechanical damage. The model parameters of undamaged and damaged specimens were estimated via numerical regressions of test results. For each sample, the experimental and fitted tensile strengths were statistically compared using hypothesis tests. For each geogrid, tensile load–strain curves of damaged samples were drawn by applying scaling factors to the plot of the undamaged sample. The curve fittings resulted in high R2 values for undamaged and damaged specimens of the geogrids. For most samples, there was no significant mean difference between the experimental and fitted tensile strength. The model allowed us to describe the load–strain curve of a geogrid from its tensile properties: εmax, Tmax and Ji. Regardless of the type of damage (in laboratory or in situ), the model was able to describe the load–strain curves of damaged samples using data from undamaged samples and scaling factors.
Design and Analysis of a Supine Ankle Rehabilitation Robot for Early Stroke Recovery
Authors: Meng Qingyun , Liu Guanxin , Xu Xin , Meng Qiaoling , Yu Hongliu
Published: July 2023

Existing ankle rehabilitation robots are large, difficult to move, and mostly designed for seated use, which cannot meet the early bedridden rehabilitation goals of stroke patients. To address these issues, a supine ankle rehabilitation robot (S-ARR) specifically designed for early bedridden rehabilitation of stroke patients has been proposed. The S-ARR is designed to be easily movable and adaptable to different heights. It features a variable workspace with mechanical limiters at the rotating joints. A kinematic model has been constructed, and the kinematic simulation of the S-ARR has been analyzed. A control system scheme for the S-ARR has been proposed. Additionally, experiments have been conducted on the prototype to measure joint range of motion and perform rehabilitation exercises. The simulation and experimental results demonstrate that the S-ARR has a feasible workspace and a relatively smooth motion process, enabling it to achieve supine ankle rehabilitation training. This indicates that the design of the supine ankle rehabilitation robot is reasonable, capable of meeting the requirements for ankle joint rehabilitation training, and has practical utility.
Magnetic, Optical, and Thermic Properties of SrLnCuSe3 (Ln = Dy, Ho, Er, Tm) Compounds
Authors: Habibullayev Navruzbek N. , Naumov Nikolay G. , Lavrov Alexander N. , Kuratieva Natalia V. , Aleksandrovsky Aleksandr S. , Oreshonkov Aleksandr S. , Molokeev Maxim S. , Palamarchuk Irina V. , Yurev Ilya O. , Denisenko Yuriy G. , Andreev Oleg V. , Zakharova Alena D.
Published: July 2023

SrLnCuSe3 (Ln = Dy, Ho, Er, Tm) compounds crystallize in the Pnma and Cmcm orthorhombic space group and belong to the Eu2CuS3 and KCuZrS3 structural type, respectively. According to a single-crystal XRD study, the SrTmCuSe3 unit cell parameters are a = 4.0631 (4), b = 13.4544 (14), c = 10.4430 (10) Å, and V = 570.88 (10) Å3. All the studied SrLnCuSe3 samples in the temperature range of 1.77–300 K demonstrate paramagnetic behavior without any features pointing to magnetic ordering. The measured Curie constants coincide with the values expected for Ln3+ ions with good accuracy, which confirms the stoichiometric composition of the samples and the non-magnetic state of the copper ions, Cu1+ (S = 0). The conducted optical absorption study showed that the polycrystalline SrLnCuSe3 (Ln = Dy, Ho, Er, Tm) samples are semiconductors with a direct bandgap ranging from 2.14 eV to 2.31 eV. Two indirect bandgaps were revealed and explained by the presence of optical transitions to highly dispersive subbands in the conduction band. The compounds demonstrate two reversible phase transitions α⇆β, β⇆γ and an incongruent melting at 1606 K (Dy), 1584 K (Ho), 1634 K (Er), and 1620 K (Tm) associated with the formation of solid solutions of SrSe, Cu2-XSe, and Ln2Se3 binary compounds.
Raindrop-Removal Image Translation Using Target-Mask Network with Attention Module
Authors: Kwon Hyuk-Ju , Lee Sung-Hak
Published: July 2023

Image processing plays a crucial role in improving the performance of models in various fields such as autonomous driving, surveillance cameras, and multimedia. However, capturing ideal images under favorable lighting conditions is not always feasible, particularly in challenging weather conditions such as rain, fog, or snow, which can impede object recognition. This study aims to address this issue by focusing on generating clean images by restoring raindrop-deteriorated images. Our proposed model comprises a raindrop-mask network and a raindrop-removal network. The raindrop-mask network is based on U-Net architecture, which learns the location, shape, and brightness of raindrops. The rain-removal network is a generative adversarial network based on U-Net and comprises two attention modules: the raindrop-mask module and the residual convolution block module. These modules are employed to locate raindrop areas and restore the affected regions. Multiple loss functions are utilized to enhance model performance. The image-quality assessment metrics of proposed method, such as SSIM, PSNR, CEIQ, NIQE, FID, and LPIPS scores, are 0.832, 26.165, 3.351, 2.224, 20.837, and 0.059, respectively. Comparative evaluations against state-of-the-art models demonstrate the superiority of our proposed model based on qualitative and quantitative results.
An Optimal Opportunistic Maintenance Planning Integrating Discrete- and Continuous-State Information
Authors: Wei Fanping , Wang Jingjing , Ma Xiaobing , Yang Li , Qiu Qingan
Published: July 2023

Information-driven group maintenance is crucial to enhance the operational availability and profitability of diverse industrial systems. Existing group maintenance models have primarily concentrated on a single health criterion upon maintenance implementation, where the fusion of multiple health criteria is rarely reported. However, this is not aligned with actual maintenance planning of multi-component systems on many occasions, where multi-source health information can be integrated to support robust decision making. Additionally, how to improve maintenance effectiveness through a scientific union of both scheduled and unscheduled maintenance remains a challenge in group maintenance. This study addresses these research gaps by devising an innovative multiple-information-driven group replacement policy for serial systems. In contrast to existing studies, both discrete-state information (hidden defect) and continuous degradation information are employed for group maintenance planning, and scheduled postponed maintenance and unscheduled opportunistic maintenance are dynamically integrated for the first time to mitigate downtime loss. To be specific, inspections are equally spaced to reveal system health states, followed by the multi-level replacement implemented when either (a) the degradation of the continuously degrading unit reaches a specified threshold, or (b) the age of the multi-state unit since the defect’s identification reaches a pre-set age (delayed replacement). Such scheduling further enables the implementation of multi-source opportunistic replacement to alleviate downtime. The Semi-Markov Decision Process (SMDP) is utilized for the collaborative optimization of continuous- and discrete-state thresholds, so as to minimize the operational costs. Numerical experiments conducted on the critical structure of circulating pumps verify the model’s applicability.
Free Vibration Analysis of Trapezoidal Bi-Stable Laminates Supported at the Elastic Midpoint of the Median Line
Authors: Xu Yonggui , Hao Yuxin , Zhang Wei , Zhang Yuhan
Published: July 2023

This study investigates the natural vibration of trapezoidal bi-stable laminates (TBL) with elastic supports at the midpoints of the median lines. Configuration of the midplane of the TBL is expressed by a polynomial with 17 parameters. Then, the first order shear deformation theory, curing temperature, and nonlinear strain displacement relations combining energy principles are applied to obtain the bi-stable shapes numerically. Three translational springs and two rotational springs are added at the midpoint of the median line in the trapezoidal bi-stable laminate to acquire elastic point supports. And, by varying the stiffness of the springs, arbitrary elastic point support boundary conditions can be achieved. Chebyshev polynomials are applied to characterize the mode shape function of the TBL. The vibration mode functions of the TBL are mapped to a square area under the new coordinate system by using the coordinate mapping method. Furthermore, the effects of geometry, layup sequence, and spring stiffness on the natural vibrations of the TBL are analyzed, which provides a reference for research in this field. The innovation and highlights lie in the following: (1) the natural frequencies and modes of trapezoidal bi-stable plates are solved; (2) arbitrary elastic support is achieved by a set of artificial springs; (3) the influences of spring stiffness, layer sequence, and trapezoidal base angle on the natural vibration of a trapezoidal bi-stable plate are studied.
Pattern Formation in a Predator–Prey Model with Allee Effect and Hyperbolic Mortality on Multiplex Networks
Authors: Shi Lei , Zhou Jiaying , Ye Yong
Published: July 2023

With the rapid development of network science, Turing patterns on complex networks have attracted extensive attention from researchers. In this paper, we focus on spatial patterns in multiplex ER (Erdös-Rényi) random networks, taking the predator–prey model with Allee effect and hyperbolic mortality as an example. In theory, the threshold condition for generating Turing patterns is given using the Turing instability theory of multiplex networks. Numerically, we design relevant experiments to explore the impact of network topology on Turing patterns. The factors considered include model parameters, diffusion rate, average degree of the network, and differences in the average degree of different layers. The results indicate that the importance of diffusion rate and network average degree for Turing patterns is affirmed on the single-layer network. For multiplex networks, the differentiation of average degrees in different layers controls the generation of Turing patterns, which are not affected by the diffusion rates of the two populations. More interestingly, we observe the switching of Turing patterns and spatiotemporal patterns. We believe that these findings contribute to a better understanding of self-organization on complex networks.
Achieving Effective Learning Outcomes through the Use of Analogies in Teaching Computer Science
Authors: Saxena Pawan , Singh Sanjay Kumar , Gupta Gopal
Published: July 2023

Analogy-based learning methods map the concept being learned to a concept well understood by the learner. An analogy is primarily useful when learners do not know the topic being studied. Computer science is an area where the concepts exhibit a high level of abstraction and, hence, are hard for students to comprehend. The use of analogies in instruction can significantly reduce the cognitive load a student faces in learning abstract computer science concepts. The role of analogies in helping students learn computer science topics has not been explored adequately. This paper presents our efforts related to using analogy-based teaching in computer science. Over the last several years, we have developed extensive analogies for many advanced computer science concepts. We have used these analogies extensively in classroom teaching at our institution. We list the analogies that we have developed and used in our classroom teaching and, as illustration, discuss two analogies: one from the field of operating systems and another one in modular software design. We have also conducted experiments to evaluate the impact of using these two analogies on student learning outcomes. Our results confirm our hypothesis that analogy-based instruction techniques are effective and result in improved student learning outcomes.
A Proposed Application of Fractional Calculus on Time Dilation in Special Theory of Relativity
Authors: Algehyne Ebrahem A. , Aldhabani Musaad S. , Areshi Mounirah , El-Zahar Essam R. , Ebaid Abdelhalim , Al-Jeaid Hind K.
Published: July 2023

Time dilation (TD) is a principal concept in the special theory of relativity (STR). The Einstein TD formula is the relation between the proper time t0 measured in a moving frame of reference with velocity v and the dilated time t measured by a stationary observer. In this paper, an integral approach is firstly presented to rededuce the Einstein TD formula. Then, the concept of TD is introduced and examined in view of the fractional calculus (FC) by means of the Caputo fractional derivative definition (CFD). In contrast to the explicit standard TD formula, it is found that the fractional TD (FTD) is governed by a transcendental equation in terms of the hyperbolic function and the fractional-order α. For small v compared with the speed of light c (i.e., v≪c), our results tend to Newtonian mechanics, i.e., t→t0. For v comparable to c such as v=0.9994c, our numerical results are compared with the experimental ones for the TD of the muon particles μ+. Moreover, the influence of the arbitrary-order α on the FTD is analyzed. It is also declared that at a specific α, there is an agreement between the present theoretical results and the corresponding experimental ones for the muon particles μ+.
Three-Way Co-Training with Pseudo Labels for Semi-Supervised Learning
Authors: Wang Liuxin , Gao Can , Zhou Jie , Wen Jiajun
Published: July 2023

The theory of three-way decision has been widely utilized across various disciplines and fields as an efficient method for both knowledge reasoning and decision making. However, the application of the three-way decision theory to partially labeled data has received relatively less attention. In this study, we propose a semi-supervised co-training model based on the three-way decision and pseudo labels. We first present a simple yet effective method for producing two views by assigning pseudo labels to unlabeled data, based on which a heuristic attribute reduction algorithm is developed. The three-way decision is then combined with the concept of entropy to form co-decision rules for classifying unlabeled data into useful, uncertain, or useless samples. Finally, some useful samples are iteratively selected to improve the performance of the co-decision model. The experimental results on UCI datasets demonstrate that the proposed model outperforms other semi-supervised models, exhibiting its potential for partially labeled data.
A Bibliometric Analysis of Digital Twin in the Supply Chain
Authors: Lam Weng Siew , Lam Weng Hoe , Lee Pei Fun
Published: July 2023

Digital twin is the digital representation of an entity, and it drives Industry 4.0. This paper presents a bibliometric analysis of digital twin in the supply chain to help researchers, industry practitioners, and academics to understand the trend, development, and focus of the areas of digital twin in the supply chain. This paper found several key clusters of research, including the designing of a digital twin model, integration of a digital twin model, application of digital twin in quality control, and digital twin in digitalization. In the embryonic stage of research, digital twin was tested in the production line with limited optimization. In the development stage, the importance of digital twin in Industry 4.0 was observed, as big data, machine learning, Industrial Internet of Things, blockchain, edge computing, and cloud-based systems complemented digital twin models. Digital twin was applied to improve sustainability in manufacturing and production logistics. In the current prosperity stage with high annual publications, the recent trends of this topic focus on the integration of deep learning, data models, and artificial intelligence for digitalization. This bibliometric analysis also found that the COVID-19 pandemic drove the start of the prosperity stage of digital twin research in the supply chain. Researchers in this field are slowly moving towards applying digital twin for human-centric systems and mass personalization to prepare to transit to Industry 5.0.
Continuous and Discrete ZND Models with Aid of Eleven Instants for Complex QR Decomposition of Time-Varying Matrices
Authors: Chen Jianrong , Kang Xiangui , Zhang Yunong
Published: July 2023

The problem of QR decomposition is considered one of the fundamental problems commonly encountered in both scientific research and engineering applications. In this paper, the QR decomposition for complex-valued time-varying matrices is analyzed and investigated. Specifically, by applying the zeroing neural dynamics (ZND) method, dimensional reduction method, equivalent transformations, Kronecker product, and vectorization techniques, a new continuous-time QR decomposition (CTQRD) model is derived and presented. Then, a novel eleven-instant Zhang et al discretization (ZeaD) formula, with fifth-order precision, is proposed and studied. Additionally, five discrete-time QR decomposition (DTQRD) models are further obtained by using the eleven-instant and other ZeaD formulas. Theoretical analysis and numerical experimental results confirmed the correctness and effectiveness of the proposed continuous and discrete ZND models.
Astaxanthin: A Marine Drug That Ameliorates Cerebrovascular-Damage-Associated Alzheimer’s Disease in a Zebrafish Model via the Inhibition of Matrix Metalloprotease-13
Authors: Paramakrishnan Nallupillai , Lim Khian Giap , Paramaswaran Yamunna , Ali Nemat , Waseem Mohammad , Shazly Gamal A. , Bin Jardan Yousef A. , Muthuraman Arunachalam
Published: July 2023

Alzheimer’s disease (AD) is a major type of dementia disorder. Common cognitive changes occur as a result of cerebrovascular damage (CVD) via the disruption of matrix metalloproteinase-13 (MMP-13). In diabetic cases, the progress of vascular dementia is faster and the AD rate is higher. Patients with type 2 diabetes are known to have a higher risk of the factor for AD progression. Hence, this study is designed to investigate the role of astaxanthin (AST) in CVD-associated AD in zebrafish via the inhibition of MMP-13 activity. CVD was developed through the intraperitoneal and intracerebral injection of streptozotocin (STZ). The AST (10 and 20 mg/L), donepezil (1 mg/L), and MMP-13 inhibitor (i.e., CL-82198; 10 μM) were exposed for 21 consecutive days in CVD animals. The cognitive changes in zebrafish were evaluated through light and dark chamber tests, a color recognition test, and a T-maze test. The biomarkers of AD pathology were assessed via the estimation of the cerebral extravasation of Evans blue, tissue nitrite, amyloid beta-peptide aggregation, MMP-13 activity, and acetylcholinesterase activity. The results revealed that exposure to AST leads to ameliorative behavioral and biochemical changes. Hence, AST can be used for the management of AD due to its multi-targeted actions, including MMP-13 inhibition.
Nonfamilial VACTERL-H Syndrome in a Dizygotic Twin: Prenatal Ultrasound and Postnatal 3D CT Findings
Authors: Hong Seol Young , Kim Soo Jung , Park Mi-Hye , Lee Kyung A.
Published: July 2023

Background: VACTERL association is a widely known congenital malformation that includes vertebral, anal, cardiac, tracheoesophageal, renal, and limb anomalies. Patients with VACTERL and hydrocephalus appear to form a distinct group, both genetically and phenotypically, and their condition has been called VACTERL-H syndrome. Most cases of VACTERL-H have been reported postnatally, as VACTER-H syndrome is difficult to diagnose prenatally. Case Presentation: Here, we report a case of VACTERL-H syndrome in a dichorionic and diamniotic twin diagnosed prenatally by ultrasonography and confirmed postnatally by three-dimensional computed tomography (3D CT). A 34-year-old multiparous female was referred to our institution at 31 + 3 weeks gestation for suspected fetal ventriculomegaly. Detailed examinations using two-dimensional and Doppler ultrasounds revealed hydrocephalus, bilateral dysplastic upper arms, radial aplasia, unilateral pulmonary agenesis, dextrocardia with right atrial enlargement, a unilateral hypoplastic ectopic kidney, a single umbilical artery, a tracheoesophageal fistula with a small stomach, polyhydramnios, and anal atresia. Findings from the postnatal 3D CT aligned with the prenatal diagnosis, showing upper-limb agenesis, dextrocardia with pulmonary hypoplasia, tracheoesophageal fistula, imperforate anus, and colon dilatation. The affected 1390-g male twin had an unaffected 1890-g female twin sister and a healthy 6-year-old brother. Conclusions: Upon encountering fetuses with multiple anomalies, including ventriculomegaly, a small stomach with polyhydramnios, an abnormally positioned heart, and upper-limb abnormalities, clinicians should perform systematic ultrasonographic examinations to detect associated anomalies and be aware of VACTERL-H syndrome.
Cenobamate (YKP3089) and Drug-Resistant Epilepsy: A Review of the Literature
Authors: Rissardo Jamir Pitton , Fornari Caprara Ana Letícia
Published: July 2023

Cenobamate (CNB), ([(R)-1-(2-chlorophenyl)-2-(2H-tetrazol-2-yl)ethyl], is a novel tetrazole alkyl carbamate derivative. In November 2019, the Food and Drug Administration approved Xcopri®, marketed by SK Life Science Inc., (Paramus, NJ, USA) for adult focal seizures. The European Medicines Agency approved Ontozry® by Arvelle Therapeutics Netherlands B.V.(Amsterdam, The Neatherlands) in March 2021. Cenobamate is a medication that could potentially change the perspectives regarding the management and prognosis of refractory epilepsy. In this way, this study aims to review the literature on CNB’s pharmacological properties, pharmacokinetics, efficacy, and safety. CNB is a highly effective drug in managing focal onset seizures, with more than twenty percent of individuals with drug-resistant epilepsy achieving seizure freedom. This finding is remarkable in the antiseizure medication literature. The mechanism of action of CNB is still poorly understood, but it is associated with transient and persistent sodium currents and GABAergic neurotransmission. In animal studies, CNB showed sustained efficacy and potency in the 6 Hz test regardless of the stimulus intensity. CNB was revealed to be the most cost-effective drug among different third-generation antiseizure medications. Also, CNB could have neuroprotective effects. However, there are still concerns regarding its potential for abuse and suicidality risk, which future studies should clearly assess, after which protocols should be changed. The major drawback of CNB therapy is the slow and complex titration and maintenance phases preventing the wide use of this new agent in clinical practice.
Urinary Marinobufagenin in Patients with Non-Advanced Chronic Kidney Disease: A Cross-Sectional Study
Authors: Bolignano Davide , Greco Marta , D’Agostino Mario , Cianfrone Paola , Tripodi Loredana , Misiti Roberta , Zicarelli Mariateresa , Ganino Ludovica , Foti Daniela Patrizia , Andreucci Michele , Coppolino Giuseppe
Published: July 2023

Background and Objectives: The global prevalence of chronic kidney disease (CKD) is on the rise, posing important challenges for healthcare systems. Thus, the search for new factors potentially involved in the pathogenesis, progression and complications of early CKD remains urgent. Marinobufagenin (MBG) is a natriuretic endogenous cardiotonic steroid, and increased circulating levels of it may accelerate kidney damage. In this study, we explored the possible clinical significance of measuring urinary marinobufagenin (uMBG) in patients with non-advanced CKD. Materials and Methods: One hundred and eight adult CKD patients (mean age 71.6 ± 10 years, 70.4% male; mean eGFR 40.54 ± 17 mL/min/1.73 m2) were enrolled in this cross-sectional study. uMBG was measured together with a series of clinical, anthropometric, laboratory and instrumental analyses. Twenty-five healthy matched subjects served as controls for the uMBG measurement. Results: The uMBG values were lower in the patients with CKD as compared to those of the controls (0.37 [IQR: 0.25–0.45] vs. 0.64 [0.46–0.78] nmol/L. p = 0.004), and a significant trend in eGFR levels was noticed across the decreasing uMBG tertiles (p = 0.03). Regarding the correlation analyses, the uMBG values remained robustly associated with the eGFR in multivariate models employing either uMBG or eGFR as the dependent variable (β = 0.248; p = 0.01 and β = 0.139; p = 0.04, respectively). Besides the eGFR, the independent predictors of uMBG values in this population were the use of statins (β = −0.326; p = 0.001), the presence of diabetes (β = 0.243; p = 0.009) and urine sodium (β = 0.204; p = 0.01). Conclusions: Reduced uMBG excretion may reflect impaired renal clearance, which may contribute to the detrimental effects attributed to this hormone due to systemic accumulation. Future studies are needed to clarify the biological mechanisms placing uMBG at the crossroad of sodium intake and the presence of diabetes in CKD-suffering individuals and to verify whether a statin treatment may somewhat limit the detrimental effects of MBG in the presence of impaired renal function.
Accurate Prediction of Sudden Cardiac Death Based on Heart Rate Variability Analysis Using Convolutional Neural Network
Authors: Panjaitan Febriyanti , Nurmaini Siti , Partan Radiyati Umi
Published: July 2023

Sudden cardiac death (SCD) is a significant global health issue that affects individuals with and without a history of heart disease. Early identification of SCD risk factors is crucial in reducing mortality rates. This study aims to utilize electrocardiogram (ECG) tools, specifically focusing on heart rate variability (HRV), to detect early SCD risk factors. In this study, we expand the comparison group dataset to include five groups: Normal Sinus Rhythm (NSR), coronary artery disease (CAD), Congestive Heart Failure (CHF), Ventricular Tachycardia (VT), and SCD. ECG signals were recorded for 30 min and segmented into 5 min intervals, following the recommended HRV feature analysis guidelines. We introduce an innovative approach to HRV signal analysis by utilizing Convolutional Neural Networks (CNN). The CNN model was optimized by tuning hyperparameters such as the number of layers, learning rate, and batch size, significantly impacting the prediction accuracy. The findings demonstrate that the HRV approach, in conjunction with linear features and the DL method, achieved a higher accuracy rate, averaging 99.30%, reaching 97% sensitivity, 99.60% specificity, and 97.87% precision. Future research should focus on further exploring and refining DL methods in the context of HRV analysis to improve SCD prediction.
The Cardiac Comeback-Beating Stronger: Exploring the Remarkable Resilience of the Heart in COVID-19 Recovery through Cardiac Autonomic Analysis
Authors: Garg Sakshi , Saini Preeti , Rizvi Moattar Raza , Ahmad Fuzail , AlTaweel Mohammed , Sabah Zia Ul , Durrani Humayoun K. , Almasswary Shatha A. , Seyam Mohamed K. , Sharma Ankita , Ahmad Irshad , Marzoogi Sara Al , Shaphe Mohammad A. , Uddin Shadab , Ahmad Irshad
Published: July 2023

Background and Objectives: Analyzing the cardiac autonomic function in COVID-19 patients can provide insights into the impact of the virus on the heart’s regulatory mechanisms and its recovery. The autonomic nervous system plays a crucial role in regulating the heart’s functions, such as heart rate, blood pressure, and cardiac output. This study aimed to investigate the impact of COVID-19 on heart rate variability (HRV) during a 6-min walk test (6MWT). Materials and Methods: The study included 74 participants, consisting of 37 individuals who had recovered from mild to moderate COVID-19 and 37 healthy controls. The study assessed heart rate variability (HRV) and blood pressure both before and after a 6-min walk test (6MWT). Results: The study found significant differences in a few time domains (SDNN and pNN50) and all frequency domain measures, whereas there were no significant differences in demographic characteristics or blood pressure between COVID-19-recovered individuals and healthy controls at rest. There were significant 6MWT effects on average HR, time-domain (SDNN and pNN50) measures of HRV, and all frequency domain measures of HRV. A significant group × 6MWT interaction was found for SDNN, pNN50, total power, Ln total power, LF, HF, Ln LF, Ln HF, and LF nu. Conclusions: Cardiac Autonomic analysis through HRV is essential to ensure the continued health and well-being of COVID-19 survivors and to minimize the potential long-term impacts of the disease on their cardiovascular system. This suggests that HRV analysis during the recovery phase following exercise could serve as a valuable tool for evaluating the physiological effects of COVID-19 and monitoring the recovery process.
Amyloid Precursor Protein Changes Arrangement in a Membrane and Its Structure Depending on the Cholesterol Content
Authors: Krasnobaev Vladimir D. , Bershatsky Yaroslav V. , Bocharova Olga V. , Bocharov Eduard V. , Batishchev Oleg V.
Published: July 2023

One of the hallmarks of Alzheimer’s disease (AD) is the accumulation of amyloid beta (Aβ) peptides in the brain. The processing of amyloid precursor protein (APP) into Aβ is dependent on the location of APP in the membrane, membrane lipid composition and, possibly, presence of lipid rafts. In this study, we used atomic force microscopy (AFM) to investigate the interaction between transmembrane fragment APP672–726 (corresponding to Aβ1–55) and its amyloidogenic mutant L723P with membranes combining liquid-ordered and liquid-disordered lipid phases. Our results demonstrated that most of the APP672–726 is located either in the liquid-disordered phase or at the boundary between ordered and disordered phases, and hardly ever in rafts. We did not notice any major changes in the domain structure induced by APP672–726. In membranes without cholesterol APP672–726, and especially its amyloidogenic mutant L723P formed annular structures and clusters rising above the membrane. Presence of cholesterol led to the appearance of concave membrane regions up to 2 nm in depth that were deeper for wild type APP672–726. Thus, membrane cholesterol regulates changes in membrane structure and permeability induced by APP that might be connected with further formation of membrane pores.
Precise Filtration of Chronic Myeloid Leukemia Cells by an Ultrathin Microporous Membrane with Backflushing to Minimize Fouling
Authors: Lee Jaehyuk , Hong Jeongpyo , Lee Jungwon , Lee Changgyu , Kim Tony , Jeong Young , Kim Kwanghee , Jung Inhwa
Published: July 2023

A cell filtration platform that affords accurate size separation and minimizes fouling was developed. The platform features an ultra-thin porous membrane (UTM) filter, a pumping head filtration with backflush (PHF), and cell size measurement (CSM) software. The UTM chip is an ultrathin free-standing membrane with a large window area of 0.68 mm2, a pore diameter of 5 to 9 μm, and a thickness of less than 0.9 μm. The PHF prevents filter fouling. The CSM software analyzes the size distributions of the supernatants and subnatants of isolated cells and presents the data visually. The D99 particle size of cells of the chronic myeloid leukemia (CML) line K562 decreased from 22.2 to 17.5 μm after passage through a 5-μm filter. K562 cells could be separated by careful selection of the pore size; the recovery rate attained 91.3%. The method was compared to conventional blocking models by evaluating the mean square errors (MSEs) between the measured and calculated filtering volumes. The filtering rate was fitted by a linear regression model with a significance that exceeded 0.99 based on the R2 value. The platform can be used to separate various soft biomaterials and afford excellent stability during filtration.
Real-Time Observation of Capsaicin-Induced Intracellular Domain Dynamics of TRPV1 Using the Diffracted X-ray Tracking Method
Authors: Mio Kazuhiro , Ohkubo Tatsunari , Sasaki Daisuke , Arai Tatsuya , Sugiura Mayui , Fujimura Shoko , Nozawa Shunsuke , Sekiguchi Hiroshi , Kuramochi Masahiro , Sasaki Yuji C.
Published: July 2023

The transient receptor potential vanilloid type 1 (TRPV1) is a multimodal receptor which responds to various stimuli, including capsaicin, protons, and heat. Recent advances in cryo-electron microscopy have revealed the structures of TRPV1. However, due to the large size of TRPV1 and its structural complexity, the detailed process of channel gating has not been well documented. In this study, we applied the diffracted X-ray tracking (DXT) technique to analyze the intracellular domain dynamics of the TRPV1 protein. DXT enables the capture of intramolecular motion through the analysis of trajectories of Laue spots generated from attached gold nanocrystals. Diffraction data were recorded at two different frame rates: 100 μs/frame and 12.5 ms/frame. The data from the 100 μs/frame recording were further divided into two groups based on the moving speed, using the lifetime filtering technique, and they were analyzed separately. Capsaicin increased the slope angle of the MSD curve of the C-terminus in 100 μs/frame recording, which accompanied a shifting of the rotational bias toward the counterclockwise direction, as viewed from the cytoplasmic side. This capsaicin-induced fluctuation was not observed in the 12.5 ms/frame recording, indicating that it is a high-frequency fluctuation. An intrinsic counterclockwise twisting motion was observed in various speed components at the N-terminus, regardless of the capsaicin administration. Additionally, the competitive inhibitor AMG9810 induced a clockwise twisting motion, which is the opposite direction to capsaicin. These findings contribute to our understanding of the activation mechanisms of the TRPV1 channel.
Effect of Beam Oscillation Amplitude on Microstructure and Mechanical Properties of Small Laser Spot Welded QP980 Steel
Authors: Yang Jingwei , Li Tao , Ye Wolin , Chen Jiale , Qiao Jian
Published: July 2023

In this study, butt welds of QP980 steel were produced using small laser spot (0.1 mm) oscillating welding. The effect of beam oscillation with a circular trajectory on weld morphologies, microstructures, and mechanical properties was characterized. As the oscillating amplitude rose, the energy accumulation range enlarged, and the energy peak value was decreased, leading to the appearance of the cross-section changing from a nail-like shape to a cup-cone-like shape and then to a W-type shape. The weld zone is divided into the fusion zone, inner heat-affected zone, and outer soften zone. The fusion zone and inner heat-affected zone are full of typical lath martensite and have the highest hardness. The soften zone is composed of pre-existing martensite, temper martensite, ferrite, and retained austenite and has the lowest hardness. Compared to laser welding, beam oscillation could reduce the pre-existing block martensite to decompose, leading to a narrower width and higher hardness soften zone. Although the width of the fusion zone and soften zone increases with the oscillation amplitude, all welded samples failed at the base metal with 97% joint efficiency.
Hydrogen-Assisted Microdamage of Eutectoid Pearlitic Steel in the Presence of Notches: The Tearing Topography Surface
Authors: Toribio Jesús
Published: July 2023

This paper studies the hydrogen-assisted microdamage (HAMD) in fully-pearlitic steel. A detailed analysis is provided of the HAMD region in axisymmetric round-notched samples of high-strength eutectoid pearlitic steel under hydrogen embrittlement environmental conditions. The microscopic appearance and evolution of the hydrogen affected region is analyzed from the initiation (sub-critical) to the fracture (critical) situations. The use of very distinct notched samples and their associated stress distributions in the vicinity of the notch tip allows for a study of the key role of the triaxial stress state on hydrogen diffusion and micro-cracking (or micro-damage). The microscopic appearance of the hydrogen-affected zone (the so-called tearing topography surface) resembles micro-damage, micro-cracking or micro-tearing at a micro- or nano-scale due to hydrogen degradation, thus affecting the notch tensile strength and producing hydrogen embrittlement. A micromechanical model is proposed to explain these hydrogen effects on the material on the basis of the lamellar micro- and nano-structure of the pearlitic steel.
Erosion Mechanism of Carbon Brick in Hearth of 4000 m3 Industrial Blast Furnace
Authors: Cao Jian , Zhang Jianliang , Wang Cui , Deng Yong , Zhang Guohua , Song Mingbo
Published: July 2023

After dissection of a large blast furnace, the erosion mechanism of carbon bricks after service in a blast furnace (BF) hearth was studied. Obvious “elephant foot” erosion characteristics emerged in the height direction of the BF. The existing forms of carbon bricks after service were characterized by X-ray diffraction (XRD), scanning electron microscopy–energy dispersive spectroscopy (SEM-EDS), and chemical analysis. The results showed that Zn and iron erosion above and below the taphole was observed in the BF, while iron and Zn erosion acted only as a key factor of carbon brick erosion. The convective heat transfer coefficient in the lower part of the hearth of the BF was large, which increased the temperature of the hearth sidewall, resulting in the increase in the carbon-unsaturation of the molten iron at the sidewall, and intensified erosion to the hearth sidewall. The average pore size (1.083 μm) of the carbon bricks on the hot-face of the hearth sidewall was smaller than the critical size (2.12 μm) of the molten iron that penetrated the pores of the carbon bricks, which was not conducive to the penetration of molten iron.
Pre–Placed Metal Laser–Additive Manufacturing on Grade 5 Titanium Substrate: Layer Formation, Oxidation Resistance, and Wear Resistance
Authors: Lin Junyu , Wang Ji , Xu Chang , Li Benben , Chen Bin , Xu Peiquan , Li Leijun
Published: July 2023

The laser parameters and additive materials were investigated for the laser–additive manufacturing of titanium alloys. A pre–placed metal–strip–based method for 3D printing titanium components was proposed. Before laser processing, the metal strips were fixed to a Grade 5 titanium substrate using resistance spot welding. The effect of the processing conditions (laser power: 1.5–3.0 kW; scanning speed: 3–9 mm·s−1; one or three layers; 1, 6, or 12 passes; Grade 2 and Grade 5 as additives) on the microstructures, oxidation resistance, and wear resistance of the as–printed samples was investigated. The results showed that the microstructure consisted of α′ martensite, oxygen–stabilized α, transformed β that contains coarse and fine acicular α, titanium oxides, and carbides. Cracks were observed, particularly near the upper surface of the three–layer samples. The cracks were suggested to have formed due to cumulative residual stresses and the formation of oxygen–stabilized α and α′ martensite that might cause embrittlement. Both oxidation and wear tests were conducted to verify the improved performance. After 55 h of oxidation, the as–printed samples showed mass gains of 0.029–0.035 g·cm−2, which were smaller than those of the substrate (0.039 g·cm−2).
Multi-Objective Optimization of Micro-Milling Titanium Alloy Ti-3Al-2.5V (Grade 9) Using Taguchi-Grey Relation Integrated Approach
Authors: Khan Muhammad Ayyaz , Jaffery Syed Husain Imran , Khan Muhammad Ali , Faraz Muhammad Iftikhar , Mufti Sachhal
Published: July 2023

This study aims to optimize the cutting parameters for the micro-milling of titanium grade 9 (Ti-3Al-2.5V). The research employs Grey Relational Analysis (GRA) and Response Surface Methodology (RSM) techniques to find the optimal combination of cutting parameters to simultaneously minimize surface roughness, burr width, burr length, and tool wear, which are selected process outcomes. The findings from Grey Relational Analysis (GRA) identify experiment number 6, with cutting conditions of f (µm/tooth) = 0.45, Vc (m/min) = 25, and ap (µm) = 60, as the most productive experiment. Analysis of variance (ANOVA) is conducted to assess the significance and influence of the process cutting parameters on different process outcomes. ANOVA reveals that the feed rate and cutting speed are the most influential input parameters, with a contribution ratio (CR) of 24.08% and 14.62%, respectively. Furthermore, ANOVA indicates that the interaction among the process parameters also significantly influences the process outcomes alongside the individual cutting parameters. The optimized combination of cutting parameters obtained through the RSM technique produces superior results in terms of reducing the process outcomes. Compared to the best run identified by Grey Relational Analysis, there is a remarkable 36.25% reduction in burr width and an 18.41% reduction in burr length, almost half of the reduction achieved in burr width. Additionally, there is a 16.11% and 14.60% reduction in surface roughness and tool wear, respectively.
Failure Analysis in Metallic Materials
Authors: Nobile Riccardo
Published: July 2023

Failure analysis is a complex task that plays a fundamental role in technical applications [...]