bluuebunny/crossref_metadata_2025 huggingface dataset:
Detrimental Roles of Hypoxia-Inducible Factor-1α in Severe Hypoxic Brain Diseases
Authors: Choi Yoon Kyung
Published: April 2024

Hypoxia stabilizes hypoxia-inducible factors (HIFs), facilitating adaptation to hypoxic conditions. Appropriate hypoxia is pivotal for neurovascular regeneration and immune cell mobilization. However, in central nervous system (CNS) injury, prolonged and severe hypoxia harms the brain by triggering neurovascular inflammation, oxidative stress, glial activation, vascular damage, mitochondrial dysfunction, and cell death. Diminished hypoxia in the brain improves cognitive function in individuals with CNS injuries. This review discusses the current evidence regarding the contribution of severe hypoxia to CNS injuries, with an emphasis on HIF-1α-mediated pathways. During severe hypoxia in the CNS, HIF-1α facilitates inflammasome formation, mitochondrial dysfunction, and cell death. This review presents the molecular mechanisms by which HIF-1α is involved in the pathogenesis of CNS injuries, such as stroke, traumatic brain injury, and Alzheimer’s disease. Deciphering the molecular mechanisms of HIF-1α will contribute to the development of therapeutic strategies for severe hypoxic brain diseases.
The SARS-CoV-2 Spike Protein Receptor-Binding Domain Expressed in Rice Callus Features a Homogeneous Mix of Complex-Type Glycans
Authors: Sobrino-Mengual Guillermo , Armario-Nájera Victoria , Balieu Juliette , Walet-Balieu Marie-Laure , Saba-Mayoral Andrea , Pelacho Ana M. , Capell Teresa , Christou Paul , Bardor Muriel , Lerouge Patrice
Published: April 2024

The spike protein receptor-binding domain (RBD) of SARS-CoV-2 is required for the infection of human cells. It is the main target that elicits neutralizing antibodies and also a major component of diagnostic kits. The large demand for this protein has led to the use of plants as a production platform. However, it is necessary to determine the N-glycan structures of an RBD to investigate its efficacy and functionality as a vaccine candidate or diagnostic reagent. Here, we analyzed the N-glycan profile of the RBD produced in rice callus. Of the two potential N-glycan acceptor sites, we found that one was not utilized and the other contained a mixture of complex-type N-glycans. This differs from the heterogeneous mixture of N-glycans found when an RBD is expressed in other hosts, including Nicotiana benthamiana. By comparing the glycosylation profiles of different hosts, we can select platforms that produce RBDs with the most beneficial N-glycan structures for different applications.
The Effects of Chronic Immunosuppressive Treatment on Morphological Changes in Cardiac Tissue and the Balance between Matrix Metalloproteinases (MMP-2 and MMP-9) and Their Inhibitors in the Rat Heart
Authors: Surówka Anna , Żołnierczuk Michał , Prowans Piotr , Grabowska Marta , Kupnicka Patrycja , Markowska Marta , Olejnik-Wojciechowska Joanna , Szlosser Zbigniew , Wilk Aleksandra , Szumilas Kamila , Kędzierska-Kapuza Karolina
Published: April 2024

Using different three-drug immunosuppressive treatment regimens in a rat model, we aimed to determine the effects of long-term therapy on metalloproteinase-2 and metalloproteinase-9 activity and the expression of their inhibitors, as well as to assess the morphology of the animals’ cardiac tissue. Our results suggest that chronic use of immunosuppressive drugs disrupts the balance between the activity of MMPs and TIMPs. Depending on the type of drug regimen used, this leads to abnormalities in the cardiac structure, collagen fiber accumulation, or cardiomyocyte hypertrophy. The information obtained in the present study allows us to conclude that the chronic treatment of rats with the most common clinical immunosuppressive regimens may contribute to abnormalities in the myocardial structure and function. The results presented in this study may serve as a prelude to more in-depth analyses and additional research into the optimal selection of an immunosuppressive treatment with the lowest possible risk of cardiovascular complications for patients receiving organ transplants.
Grape SnRK2.7 Positively Regulates Drought Tolerance in Transgenic Arabidopsis
Authors: Lan Guanquecailang , Ma Weifeng , Nai Guojie , Liang Guoping , Lu Shixiong , Ma Zonghuan , Mao Juan , Chen Baihong
Published: April 2024

In this study, we obtained and cloned VvSnRK2.7 by screening transcriptomic data to investigate the function of the grape sucrose non-fermenting kinase 2 (SnRK2) gene under stress conditions. A yeast two-hybrid (Y2H) assay was used to further screen for interaction proteins of VvSnRK2.7. Ultimately, VvSnRK2.7 was heterologously expressed in Arabidopsis thaliana, and the relative conductivity, MDA content, antioxidant enzyme activity, and sugar content of the transgenic plants were determined under drought treatment. In addition, the expression levels of VvSnRK2.7 in Arabidopsis were analyzed. The results showed that the VvSnRK2.7-EGFP fusion protein was mainly located in the cell membrane and nucleus of tobacco leaves. In addition, the VvSnRK2.7 protein had an interactive relationship with the VvbZIP protein during the Y2H assay. The expression levels of VvSnRK2.7 and the antioxidant enzyme activities and sugar contents of the transgenic lines were higher than those of the wild type under drought treatment. Moreover, the relative conductivity and MDA content were lower than those of the wild type. The results indicate that VvSnRK2.7 may activate the enzyme activity of the antioxidant enzyme system, maintain normal cellular physiological metabolism, stabilize the berry sugar metabolism pathway under drought stress, and promote sugar accumulation to improve plant resistance.
Oocyte Competence of Prepubertal Sheep and Goat Oocytes: An Assessment of Large-Scale Chromatin Configuration and Epidermal Growth Factor Receptor Expression in Oocytes and Cumulus Cells
Authors: Ferrer-Roda Mònica , Izquierdo Dolors , Gil Ana , Oliveira Maria Emilia Franco , Paramio Maria-Teresa
Published: April 2024

The oocyte competence of prepubertal females is lower compared to that of adults, mainly because they originate from small follicles. In adult females, the germinal vesicle (GV) and epidermal growth factor receptor (EGFR) have been associated with oocyte competence. This study aimed to analyze GV chromatin configuration and EGFR expression in prepubertal goat and sheep oocytes obtained from small (<3 mm) and large (≥3 mm) follicles and compare them with those from adults. GV chromatin was classified from diffuse to condensed as GV1, GVn, and GVc for goats and NSN, SN, and SNE for sheep. EGFR was quantified in cumulus cells (CCs) by Western blotting and in oocytes by immunofluorescence. Oocytes from prepubertal large follicles and adults exhibited highly condensed chromatin in goats (71% and 69% in GVc, respectively) and sheep (59% and 75% in SNE, respectively). In both species, EGFR expression in CCs and oocytes was higher in prepubertal large follicles than in small ones. In adult females, EGFR expression in oocytes was higher than in prepubertal large follicles. In conclusion, GV configuration and EGFR expression in CCs and oocytes were higher in the large than small follicles of prepubertal females.
Association between Bone Turnover Markers and Fracture Healing in Long Bone Non-Union: A Systematic Review
Authors: Perut Francesca , Roncuzzi Laura , Gómez-Barrena Enrique , Baldini Nicola
Published: April 2024

Background: Fracture healing is a very complex and well-orchestrated regenerative process involving many cell types and molecular pathways. Despite the high efficiency of this process, unsatisfying healing outcomes, such as non-union, occur for approximately 5–10% of long bone fractures. Although there is an obvious need to identify markers to monitor the healing process and to predict a potential failure in callus formation to heal the fracture, circulating bone turnover markers’ (BTMs) utility as biomarkers in association with radiographic and clinical examination still lacks evidence so far. Methods: A systematic review on the association between BTMs changes and fracture healing in long bone non-union was performed following PRISMA guidelines. The research papers were identified via the PubMed, Cochrane, Cinahl, Web of Science, Scopus, and Embase databases. Studies in which the failure of fracture healing was associated with osteoporosis or genetic disorders were not included. Results: A total of 172 studies were collected and, given the inclusion criteria, 14 manuscripts were included in this review. Changes in circulating BTMs levels were detected during the healing process and across groups (healed vs. non-union patients and healthy vs. patients with non-union). However, we found high heterogeneity in patients’ characteristics (fracture site, gender, and age) and in sample scheduling, which made it impossible to perform a meta-analysis. Conclusions: Clinical findings and radiographic features remain the two important components of non-union diagnosis so far. We suggest improving blood sample standardization and clinical data collection in future research to lay the foundations for the effective use of BTMs as tools for diagnosing non-union.
Sonography as a Diagnostic Tool in Midurethral Sling Complications: A Narrative Review
Authors: Zwierzchowska Aneta , Tomasik Paweł , Horosz Edyta , Barcz Ewa
Published: April 2024

Despite the established safety and efficacy of midurethral slings (MUS), which are the current gold standard treatment for stress urinary incontinence (SUI), the potential for postoperative complications remains a significant concern for both healthcare professionals and patients. Meanwhile, sonography has emerged as a significant diagnostic tool in urogynecology, and one of the applications of this imaging modality may be the evaluation of complications arising from MUS procedures. This review, based on a comprehensive literature search, focuses on the use of pelvic floor ultrasound (US) in the context of MUS complications. It includes analyses of randomized controlled trials, prospective, and retrospective studies, covering preoperative and postoperative investigations, to assess complications such as persistent and recurrent SUI, urinary retention and obstructive voiding, de novo urgency/overactive bladder, vaginal exposure, sling erosion, pain, and hematoma. The review critically examines the existing literature, with a particular focus on recent publications. Despite the variability in findings, it appears that for each of the discussed complications, the application of pelvic floor US can significantly support the diagnostic and therapeutic process. The paper also identifies potential future directions for the development of US applications in diagnosing MUS complications.
Lead Break during Extraction: Predisposing Factors and Impact on Procedure Complexity and Outcome: Analysis of 3825 Procedures
Authors: Kutarski Andrzej , Jacheć Wojciech , Czajkowski Marek , Stefańczyk Paweł , Kosior Jarosław , Tułecki Łukasz , Nowosielecka Dorota
Published: April 2024

Background: Currently, there are no reports describing lead break (LB) during transvenous lead extraction (TLE). Methods: This study conducted a retrospective analysis of 3825 consecutive TLEs using mechanical sheaths. Results: Fracture of the lead, defined as LB, with a long lead fragment (LF) occurred in 2.48%, LB with a short LF in 1.20%, LB with the tip of the lead in 1.78%, and LB with loss of a free-floating LF in 0.57% of cases. In total, extractions with LB occurred in 6.04% of the cases studied. In cases in which the lead remnant comprises more than the tip only, there was a 50.31% chance of removing the lead fragment in its entirety and an 18.41% chance of significantly reducing its length (to less than 4 cm). Risk factors for LB are similar to those for major complications and increased procedure complexity, including long lead dwell time [OR = 1.018], a higher LV ejection fraction, multiple previous CIED-related procedures, and the extraction of passive fixation leads. The LECOM and LED scores also exhibit a high predictive value. All forms of LB were associated with increased procedure complexity and major complications (9.96 vs. 1.53%). There was no incidence of procedure-related death among such patients, and LB did not affect the survival statistics after TLE. Conclusions: LB during TLE occurs in 6.04% of procedures, and this predictable difficulty increases procedure complexity and the risk of major complications. Thus, the possibility of LB should be taken into account when planning the lead extraction strategy and its associated training.
The Depth of the Molecular Response in Patients with Chronic Myeloid Leukemia Correlates with Changes in Humoral Immunity
Authors: Janowski Michał , Łuczkowska Karolina , Gniot Michał , Lewandowski Krzysztof , Safranow Krzysztof , Helbig Grzegorz , Machaliński Bogusław , Paczkowska Edyta
Published: April 2024

Background and Objectives: The effective treatment of chronic myeloid leukemia leads to the restoration of proper immune system function. We aimed to investigate fluctuations in circulating cytokines, angiogenic factors and complement components in patients with CML during the first year of treatment with TKI and correlate them with the degree of achieved molecular response. Material and Methods: We recruited 31 patients with newly diagnosed CML. Peripheral blood and bone marrow samples were obtained, and concentrations of serum proteins were measured using an immunology multiplex assay. Results: The study cohort was divided into two groups of optimal or non-optimal in accordance with the European Leukemia Net (ELN) guidelines. We found significantly higher concentrations of C1q, C4 and C5a in serum after 3 months of TKI treatment in patients who achieved optimal responses in the 6 months after diagnosis. The most alterations were observed during 12 months of therapy. Patients in the optimal response group were characterized by higher serum concentrations of TGF-β, EGF, VEGF, Angiopoietin 1, IFN-γ and IL-8. Conclusions: The later plasma concentrations of complement components were significantly increased in patients with optimal responses. The changes after 12 months of treatment were particularly significant. Similar changes in bone marrow samples were observed.
Comparison of Hemodynamic Parameters Based on the Administration of Remimazolam or Sevoflurane in Patients under General Anesthesia in the Beach Chair Position: A Single-Blinded Randomized Controlled Trial
Authors: Lee Sangho , Seo Jimung , Kim Doh Yoon , Lee YoungYun , Kang Hee Yong , Choi Jeong-Hyun , Kim Youngsoon , Kim Mi Kyeong , You Ann Hee
Published: April 2024

Background: We aimed to evaluate whether the administration of remimazolam as a maintenance agent for general anesthesia affects the occurrence of hypotension compared with sevoflurane when switching to the beach chair position (BCP). Methods: We conducted a prospective randomized controlled trial from June 2023 to October 2023 in adult patients undergoing orthopedic surgery under general anesthesia in the BCP. A total of 78 participants were randomly allocated to the remimazolam (R) or sevoflurane (S) groups. The primary outcome was the incidence of hypotension that occurred immediately after switching to a BCP. The secondary outcomes included differences between the study groups in perioperative blood pressure (BP), heart rate (HR), endotracheal tube extubation time, postoperative complications, and hospital length of stay (LOS). Results: The incidence of hypotension immediately after switching to a BCP was significantly higher in the S group. The risk factors associated with hypotension included sevoflurane administration and a high baseline systolic BP. In the receiver operating characteristic curve analysis for the occurrence of hypotension after the transition to a BCP, the cutoff value for systolic BP was 142 mmHg. The perioperative BP and HR were higher in the R group at several timepoints. Postoperative endotracheal tube extubation time was shorter in the R group. There were no significant differences in the postoperative complications or hospital LOS between the two groups. Conclusions: Remimazolam should be considered as an anesthetic agent to prevent hypotension when switching to BCP, and hypotension may occur frequently in patients with high baseline BP.
Production of Permanent Magnets from Recycled NdFeB Powder with Powder Extrusion Moulding
Authors: Rathfelder Stefan , Schuschnigg Stephan , Kukla Christian , Holzer Clemens , Burkhardt Carlo
Published: April 2024

In the last fifteen years, several groups have investigated metal injection moulding (MIM) of NdFeB powder to produce isotropic or anisotropic rare earth magnets of greater geometric complexity than that achieved by the conventional pressing and sintering approach. However, due to the powder’s high affinity for oxygen and carbon uptake, sufficient remanence and coercivity remains difficult. This article presents a novel approach to producing NdFeB magnets from recycled material using Powder Extrusion Moulding (PEM) in a continuous process. The process route uses powder obtained from recycling rare earth magnets through Hydrogen Processing of Magnetic Scrap (HPMS). This article presents the results of tailored powder processing, the production of mouldable feedstock based on a special binder system, and moulding with PEM to produce green and sintered parts. The magnetic properties and microstructures of debinded and sintered samples are presented and discussed, focusing on the influence of filling ratio and challenging processing conditions on interstitial content as well as density and magnetic properties.
MTP-YOLO: You Only Look Once Based Maritime Tiny Person Detector for Emergency Rescue
Authors: Shi Yonggang , Li Shaokun , Liu Ziyan , Zhou Zhiguo , Zhou Xuehua
Published: April 2024

Tiny person detection based on computer vision technology is critical for maritime emergency rescue. However, humans appear very small on the vast sea surface, and this poses a huge challenge in identifying them. In this study, a single-stage tiny person detector, namely the “You only look once”-based Maritime Tiny Person detector (MTP-YOLO), is proposed for detecting maritime tiny persons. Specifically, we designed the cross-stage partial layer with two convolutions Efficient Layer Aggregation Networks (C2fELAN) by drawing on the Generalized Efficient Layer Aggregation Networks (GELAN) of the latest YOLOv9, which preserves the key features of a tiny person during the calculations. Meanwhile, in order to accurately detect tiny persons in complex backgrounds, we adopted a Multi-level Cascaded Enhanced Convolutional Block Attention Module (MCE-CBAM) to make the network attach importance to the area where the object is located. Finally, by analyzing the sensitivity of tiny objects to position and scale deviation, we proposed a new object position regression cost function called Weighted Efficient Intersection over Union (W-EIoU) Loss. We verified our proposed MTP-YOLO on the TinyPersonv2 dataset. All these results confirm that this method significantly improves model performance while maintaining a low number of parameters and can therefore be applied to maritime emergency rescue missions.
Analyzing the Mediterranean Sea’s Dynamic Current System and Modeling of Renewable Current Energy Potential
Authors: Gucel Mehmet Ugur , Sakalli Abdulla
Published: April 2024

In recent years, investments in renewable energy sources have been increasing in order to reduce fossil fuel consumption and mitigate the effects of global warming on the marine ecosystem. Recent studies have shown that marine current energy, which is one of the renewable energy sources, can provide very high energy gains. This study focuses on the Mediterranean region, which is one of the areas where the impacts of climate change are most clearly felt. The annual and seasonal analysis of the current velocity in the study area between 2016 and 2018 was carried out using remote sensing technology, and potential energy production was calculated using an underwater turbine system we selected. As a result of the study, it was determined that the maximum current velocities were 2.2 m/s in 2016 and 2017 and 2.7 m/s in 2018. In addition, it was observed that the current speed was approximately 2.7 m/s in the spring months and 2.0 m/s in the summer months. In the fall and winter months, it was 2.1 m/s and 2.2 m/s, respectively. Research has shown that the study area, especially in the eastern coastal areas, has the capacity to generate approximately 10 GWh of energy per year with the use of underwater turbine systems.
Infragravity Wave Oscillation Forecasting in a Shallow Estuary
Authors: Gomez Bernabe , Giddings Sarah N. , Gallien Timu
Published: April 2024

Infragravity (IG) waves are low-frequency water waves, which can propagate into harbors and estuaries, affecting currents and sediment transport processes. Understanding and predicting IG oscillations inside harbors and estuaries is critical to coastal management and estimating future resilience to climate change impacts. High-resolution water level and flow velocity observations collected within Seal Beach Wildlife Refuge in Southern California are analyzed for IG energy related to atmospheric parameters, water levels, and offshore wave conditions. A proof of concept approach for predicting infragravity oscillations within an estuary using machine learning (ML) is presented.
Mechanical and Tribological Behaviour of Surface-Graphitised Al-1100 Alloy
Authors: Sahoo Baidehish , Paul Jinu , Sharma Abhishek
Published: April 2024

This study details the mechanical incorporation of graphite particles into the surface of aluminium (Al-1100) to fabricate surface composites using an electrical resistance heating-assisted pressing method. Initially, the aluminium surface is coated with graphite via solution casting. Incorporation is accomplished by locally heating the graphite–aluminium interface with electrical resistance heating and subsequent mechanical pressure application. The magnitude of softening of the aluminium surface can be regulated by process considerations such as the applied current and heating duration. Microstructural assessment of the aluminium–graphite composite was conducted using SEM, TEM, Raman spectroscopy, and XRD. The surface mechanical properties and reduced Young’s modulus were improved by more than 200% and 150%, respectively. A detailed tribological study was conducted, and the study suggested that the wear resistance and COF improved by more than 50%. The progress in wear resistance and COF is corroborated by the microstructural changes in the matrix suggested by the Raman spectroscopy and XRD results.
Analysis of Thermo-Hydrodynamic Lubrication of Three-Lobe Semi-Floating Ring Bearing Considering Temperature–Viscosity Effect and Static Pressure Flow
Authors: Dong Jiwei , Wen Huabing , Zhu Junchao , Guo Junhua , Zong Chen
Published: April 2024

High-power diesel engine turbochargers predominantly utilize floating ring bearings as their primary supporting components. To further enhance their load capacity, multi-lobe noncircular bearings have been progressively employed. This study focuses on the investigation of noncircular three-lobe SFRBs (semi-floating ring-bearing structures) in marine turbochargers. Employing the half-step center Finite Difference Method (FDM) and the Newton–Raphson iterative procedure, the impact of operational parameters such as the journal speed, external load, oil supply pressure, and oil supply temperature on the static and dynamic characteristics of the inner oil film is analyzed. Subsequently, the accuracy of the theoretical model is validated through a comparative analysis of simulation results obtained from Dyrobes and Fluent. The findings indicate that as the oil supply pressure and temperature increase, the temperature rise and maximum oil film pressure of the three-lobe SFRBs gradually decrease, while the oil film thickness progressively increases, thereby significantly improving the lubrication state. The load capacity of the three-lobe SFRBs is primarily sustained by the bottom tile, where wall friction is most likely to occur. Additionally, within the actual speed range, the stiffness and damping of the three-lobe SFRBs exhibit noticeable nonlinear characteristics.
A Bioactive Degradable Composite Bone Cement Based on Calcium Sulfate and Magnesium Polyphosphate
Authors: Peng Suping , Yang Xinyue , Zou Wangcai , Chen Xiaolu , Deng Hao , Zhang Qiyi , Yan Yonggang
Published: April 2024

Calcium sulfate bone cement (CSC) is extensively used as a bone repair material due to its ability to self-solidify, degradability, and osteogenic ability. However, the fast degradation, low mechanical strength, and insufficient biological activity limit its application. This study used magnesium polyphosphate (MPP) and constructed a composite bone cement composed of calcium sulfate (CS), MPP, tricalcium silicate (C3S), and plasticizer hydroxypropyl methylcellulose (HPMC). The optimized CS/MPP/C3S composite bone cement has a suitable setting time of approximately 15.0 min, a compressive strength of 26.6 MPa, and an injectability of about 93%. The CS/MPP/C3S composite bone cement has excellent biocompatibility and osteogenic capabilities; our results showed that cell proliferation is up to 114% compared with the control after 5 days. After 14 days, the expression levels of osteogenic-related genes, including Runx2, BMP2, OCN, OPN, and COL-1, are about 1.8, 2.8, 2.5, 2.2, and 2.2 times higher than those of the control, respectively, while the alkaline phosphatase activity is about 1.7 times higher. Therefore, the CS/MPP/C3S composite bone cement overcomes the limitations of CSC and has more effective potential in bone repair.
Smart Textile Flexible MnCo2O4 Electrodes: Urea Surface Modification for Improved Electrochemical Functionality
Authors: Yewale Manesh A. , Teli Aviraj M. , Beknalkar Sonali A. , Kumar Vineet , Shin Dong-Kil
Published: April 2024

Surface microstructure modification of metal oxides also improves the electrochemical performance of metal oxide nanoparticles. The present investigation demonstrates how varying the urea molar content during the hydrothermal process altered the surfaces of MnCo2O4 nanoparticles. Successive increases of 0.1 M in urea concentration transformed the surface shape of MnCo2O4 nanoparticles from flower-like to sheet-like microstructures. Excellent electrochemical performance of MnCo2O4 nanoparticles was demonstrated in an aqueous 1 M KOH electrolyte. The improved MnCo2O4 nanoparticles have been employed to develop an asymmetric supercapacitor (ASC). The ASC device exhibits an energy density of 13 Wh/kg at a power density of 553 W/kg and a specific capacitance of 29 F g−1 at a current density of 4 mA/cm2. The MnCo2O4 nanoparticle electrode demonstrates remarkable electrocatalytic activity in both HER and OER. The MnCo2O4 electrode shows overpotential for HER and OER at 356 mV and 1.46 V, respectively. The Tafel slopes for HER and OER of the MnCo2O4 electrode are 356 mV/dec and 187 mV/dec, respectively.
Decision Support Tool in the Selection of Powder for 3D Printing
Authors: Szczupak Ewelina , Małysza Marcin , Wilk-Kołodziejczyk Dorota , Jaśkowiec Krzysztof , Bitka Adam , Głowacki Mirosław , Marcjan Łukasz
Published: April 2024

The work presents a tool enabling the selection of powder for 3D printing. The project focused on three types of powders, such as steel, nickel- and cobalt-based and aluminum-based. An important aspect during the research was the possibility of obtaining the mechanical parameters. During the work, the possibility of using the selected algorithm based on artificial intelligence like Random Forest, Decision Tree, K-Nearest Neighbors, Fuzzy K-Nearest Neighbors, Gradient Boosting, XGBoost, AdaBoost was also checked. During the work, tests were carried out to check which algorithm would be best for use in the decision support system being developed. Cross-validation was used, as well as hyperparameter tuning using different evaluation sets. In both cases, the best model turned out to be Random Forest, whose F1 metric score is 98.66% for cross-validation and 99.10% after tuning on the test set. This model can be considered the most promising in solving this problem. The first result is a more accurate estimate of how the model will behave for new data, while the second model talks about possible improvement after optimization or possible overtraining to the parameters.
RBF-Based Fractional-Order SMC Fault-Tolerant Controller for a Nonlinear Active Suspension
Authors: Zhao Weipeng , Gu Liang
Published: April 2024

Active suspension control technologies have become increasingly significant in improving suspension performance for driving stability and comfort. An RBF-based fractional-order SMC fault-tolerant controller is developed in this research to guarantee ride comfort and handling stability when faced with the partial loss of actuator effectiveness due to failure. To obtain better control performance, fractional-order theory and the RBF algorithm are discussed to solve the jitter vibration problem in SMC, and the RBF is exploited to obtain a more appropriate switching gain. First, a half-nonlinear active suspension model and a fault car model are presented. Then, the design process of the RBF-based fractional-order SMC fault-tolerant controller is described. Next, a simulation is presented to demonstrate the effectiveness of the proposed strategy. According to the simulation, the proposed method can improve performance in the case of a healthy suspension, and the fault-tolerant controller can guarantee the capabilities when actuators go wrong.
A Liquid Nitrogen Cooling Circulation Unit: Its Design and a Performance Study
Authors: Yao Jianjie , Lu Xiangyou , Xie Yuanlai , Wang Qianxu , Liu Xiao
Published: April 2024

A liquid nitrogen cooling circulating unit is a necessary condition for the stable operation of a cryogenic oscillator, which can provide a stable working environment for the oscillator. In this paper, according to the user’s functional requirements and performance parameters, a closed cooling system with supercooled liquid nitrogen as the medium was designed using SOLIDWORKS 2021 software, which can provide a suitable working environment for the cryogenic oscillator. Combined with the system heat load analysis, theoretical calculation for and the design of the coil heat exchanger, one of the core pieces of equipment of the unit, were carried out. The performance of the designed nitrogen exhaust heater was studied using FLUENT 2021 software, and the velocity field and temperature field of the nitrogen exhaust heater were analyzed. The results show that the outlet temperature of the nitrogen exhaust heating device can reach up to 310 K, and the outlet flow rate of the heating device is 0.01528 kg/s. The experiments on the liquid nitrogen circulating unit using the simulated load equipment show that the refrigeration power of the unit can reach a design index of 600 W, and the temperature of the liquid nitrogen at the liquid outlet of the unit can reach 77.8 K. The experiments also show that the unit meets the design requirements.
Analysis of an Interface Crack between Piezoelectric Semiconductor Coating and Elastic Substrate Structure
Authors: Tian Xiangru , Zhang Yali , Ma Hailiang , Li Xing , Ding Shenghu
Published: April 2024

Piezoelectric semiconductor materials possess a unique combination of piezoelectric and semiconductor effects, exhibiting multifaceted coupling properties such as electromechanical, acoustic, photoelectric, photovoltaic, thermal, and thermoelectric capabilities. This study delves into the anti-plane mechanical model of an interface crack between a strip of piezoelectric semiconductor material and an elastic material. By introducing two boundary conditions, the mixed boundary value problem is reformulated into a set of singular integral equations with a Cauchy kernel. The details of carrier concentration, current density, and electric displacement near the crack are provided in a numerical analysis. The findings reveal that the distribution of the current density, carrier concentration, and electric displacement is intricately influenced by the doping concentration of the piezoelectric semiconductor. Moreover, the presence of mechanical and electric loads can either expedite or decelerate the growth of the crack, highlighting the pivotal role of external stimuli in influencing material behavior.
Stationary Distribution of Stochastic Age-Dependent Population–Toxicant Model with Markov Switching
Authors: Du Yanyan , Wang Zong
Published: April 2024

This work focuses on the convergence of the numerical invariant measure for a stochastic age-dependent population–toxicant model with Markov switching. Considering that Euler–Maruyama (EM) has the advantage of fast computation and low cost, explicit EM was used to discretize the time variable. With the help of the p-th moment boundedness of the analytical and numerical solutions of the model, the existence and uniqueness of the corresponding invariant measures were obtained. Under suitable assumptions, the conclusion that the numerical invariant measure converges to the invariant measure of the analytic solution was proven by defining the Wasserstein distance. A numerical simulation was performed to illustrate the theoretical results.
Spectral Properties of Mimetic Operators for Robust Fluid–Structure Interaction in the Design of Aircraft Wings
Authors: de Curtò J. , de Zarzà I.
Published: April 2024

This paper presents a comprehensive study on the spectral properties of mimetic finite-difference operators and their application in the robust fluid–structure interaction (FSI) analysis of aircraft wings under uncertain operating conditions. By delving into the eigenvalue behavior of mimetic Laplacian operators and extending the analysis to stochastic settings, we develop a novel stochastic mimetic framework tailored for addressing uncertainties inherent in the fluid dynamics and structural mechanics of aircraft wings. The framework integrates random matrix theory with mimetic discretization methods, enabling the incorporation of uncertainties in fluid properties, structural parameters, and coupling conditions at the fluid–structure interface. Through spectral and localization analysis of the coupled stochastic mimetic operator, we assess the system’s stability, sensitivity to perturbations, and computational efficiency. Our results highlight the potential of the stochastic mimetic approach for enhancing reliability and robustness in the design of aircraft wings, paving the way for optimization algorithms that integrate uncertainties directly into the design process. Our findings reveal a significant impact of stochastic perturbations on the spectral radius and eigenfunction localization, indicating heightened system sensitivity. The introduction of randomized singular value decomposition (RSVD) within our framework not only enhances computational efficiency but also preserves accuracy in low-rank approximations, which is critical for handling large-scale systems. Moreover, Monte Carlo simulations validate the robustness of our stochastic mimetic framework, showcasing its efficacy in capturing the nuanced dynamics of FSI under uncertainty. This study contributes to the fields of numerical methods and aerospace engineering by offering a rigorous and scalable approach for conducting uncertainty-aware FSI analysis, which is crucial for the development of safer and more efficient aircraft.
Linear Parameter Varying Observer-Based Adaptive Dynamic Surface Sliding Mode Control for PMSM
Authors: Li Tongtong , Tao Liang , Xu Binzi
Published: April 2024

This paper presents an adaptive dynamic surface sliding mode control technique to address the issue of system parameter changes in permanent magnet synchronous motor (PMSM) position servo systems. The proposed method involves adopting a linear parameter varying (LPV) observer-based parameter identification algorithm and adaptive control technique. Initially, a mathematical model of the PMSM is established, and the system parameters are divided into nominal and perturbation values. This allows for the reconstruction of the system model into a state space equation that incorporates the unknown perturbation parameters. To accurately estimate these unknown parameters, an LPV observer is designed based on the reconstructed model. Additionally, an adaptive dynamic surface sliding mode control technique is explored to achieve the desired tracking performance. Meanwhile, an exponential reaching law is introduced to expedite the dynamic behavior of the system and mitigate chattering. Finally, a suitable Lyapunov function is selected to ensure the overall stability of the system. The simulation results demonstrate the effectiveness of the parameter identification and control algorithm in achieving good identification and tracking control ability for PMSM systems.
Statistical Tools to Optimize the Recovery of Bioactive Compounds from Marine Byproducts
Authors: Tsegay Zenebe Tadesse , Agriopoulou Sofia , Chaari Moufida , Smaoui Slim , Varzakas Theodoros
Published: April 2024

Techniques for extracting important bioactive molecules from seafood byproducts, viz., bones, heads, skin, frames, fins, shells, guts, and viscera, are receiving emphasis due to the need for better valorization. Employing green extraction technologies for efficient and quality production of these bioactive molecules is also strictly required. Hence, understanding the extraction process parameters to effectively design an applicable optimization strategy could enable these improvements. In this review, statistical optimization strategies applied for the extraction process parameters of obtaining bioactive molecules from seafood byproducts are focused upon. The type of experimental designs and techniques applied to criticize and validate the effects of independent variables on the extraction output are addressed. Dominant parameters studied were the enzyme/substrate ratio, pH, time, temperature, and power of extraction instruments. The yield of bioactive compounds, including long-chain polyunsaturated fatty acids, amino acids, peptides, enzymes, gelatine, collagen, chitin, vitamins, polyphenolic constituents, carotenoids, etc., were the most studied responses. Efficiency and/or economic and quality considerations and their selected optimization strategies that favor the production of potential bioactive molecules were also reviewed.
Integrating Clinical Neuropsychology and Psychotic Spectrum Disorders: A Systematic Analysis of Cognitive Dynamics, Interventions, and Underlying Mechanisms
Authors: Gkintoni Evgenia , Skokou Maria , Gourzis Philippos
Published: April 2024

Background and Objectives: The study aims to provide a comprehensive neuropsychological analysis of psychotic spectrum disorders, including schizophrenia, bipolar disorder, and depression. It focuses on the critical aspects of cognitive impairments, diagnostic tools, intervention efficacy, and the roles of genetic and environmental factors in these disorders. The paper emphasizes the diagnostic significance of neuropsychological tests in identifying cognitive deficiencies and their predictive value in the early management of psychosis. Materials and Methods: The study involved a systematic literature review following the PRISMA guidelines. The search was conducted in significant databases like Scopus, PsycINFO, PubMed, and Web of Science using keywords relevant to clinical neuropsychology and psychotic spectrum disorders. The inclusion criteria required articles to be in English, published between 2018 and 2023, and pertinent to clinical neuropsychology’s application in these disorders. A total of 153 articles were identified, with 44 ultimately included for detailed analysis based on relevance and publication status after screening. Results: The review highlights several key findings, including the diagnostic and prognostic significance of mismatch negativity, neuroprogressive trajectories, cortical thinning in familial high-risk individuals, and distinct illness trajectories within psychosis subgroups. The studies evaluated underline the role of neuropsychological tests in diagnosing psychiatric disorders and emphasize early detection and the effectiveness of intervention strategies based on cognitive and neurobiological markers. Conclusions: The systematic review underscores the importance of investigating the neuropsychological components of psychotic spectrum disorders. It identifies significant cognitive impairments in attention, memory, and executive function, correlating with structural and functional brain abnormalities. The paper stresses the need for precise diagnoses and personalized treatment modalities, highlighting the complex interplay between genetic, environmental, and psychosocial factors. It calls for a deeper understanding of these neuropsychological processes to enhance diagnostic accuracy and therapeutic outcomes.
Analyzing Power Law Extensions of Newtonian Gravity Using Differential Force Measurements
Authors: Bsaibes Thomas , Decca Ricardo
Published: April 2024

The Standard Model is not a complete description of reality; it omits the existence of dark matter, dark energy, and an explanation as to why no CP violation has been observed. However, some of these phenomena could be explained through a new force mediated by a new boson. If such a boson were massless it would result in a power law potential and if massive the interaction would be Yukawa-like. A previous experiment employing the interactions of a micromechanical oscillator attached to spherical test mass was successful in placing the best limits on a mass–mass Yukawa-like interaction, but the data were never analyzed in the context of a power law. Here, those data are analyzed considering a power law for powers n = 1–5 where n is the number of boson exchanges. The results show that the limits obtained through power law analysis of these data are not better than the currently accepted limits. A discussion of an experiment design capable of producing better limits on power law extensions to the Standard Model is presented, and suggests that a micromechanical-oscillator-based experiment remains capable of improving the limits by at least one order of magnitude.
Anti-Cracking TEOS-Based Hybrid Materials as Reinforcement Agents for Paper Relics
Authors: Wu Mengruo , Mu Le , Zhang Zhiyue , Han Xiangna , Guo Hong , Han Liuyang
Published: April 2024

Tetraethoxysilane (TEOS) is the most commonly used silicon-based reinforcement agent for conserving art relics due to its cost-effectiveness and commercial maturity. However, the resulting silica gel phase is prone to developing cracks as the gel shrinks during the sol–gel process, potentially causing severe damage to the objects being treated. In this study, dodecyltrimethoxysilane (DTMS) was introduced into TEOS to minimize this shrinkage by adding elastic long chains to weaken the capillary forces. The gel formed from the DTMS/TEOS hybrid material was transparent and crack-free, featuring a dense microstructure without mesopores or micropores. It exhibited excellent thermal stability, with a glass transition temperature of up to 109.64 °C. Evaluation experiments were conducted on artificially aged, handmade bamboo paper. The TEOS-based hybrid material effectively combined with the paper fibers through the sol–gel process, polymerizing into a network structure that enveloped the paper surface or penetrated between the fibers. The surface of the treated paper displayed excellent hydrophobic properties, with no significant changes in appearance, color, or air permeability. The mechanical properties of the treated bamboo paper improved significantly, with longitudinal and transverse tensile strengths increasing by up to 36.63% and 44.25%, respectively. These research findings demonstrate the promising potential for the application of DTMS/TEOS hybrid materials in reinforcing paper relics.
Enhanced Adsorption of Methyl Orange from Aqueous Phase Using Chitosan–Palmer Amaranth Biochar Composite Microspheres
Authors: Chen Guiling , Yin Yitong , Zhang Xianting , Qian Andong , Pan Xiaoyang , Liu Fei , Li Rui
Published: April 2024

To develop valuable applications for the invasive weed Palmer amaranth, we utilized it as a novel biochar source and explored its potential for methyl orange adsorption through the synthesis of chitosan-encapsulated Palmer amaranth biochar composite microspheres. Firstly, the prepared microspheres were characterized by scanning electron microscopy and Fourier transform infrared spectroscopy and were demonstrated to have a surface area of 19.6 m2/g, a total pore volume of 0.0664 cm3/g and an average pore diameter of 10.6 nm. Then, the influences of pH, dosage and salt type and concentration on the adsorption efficiency were systematically investigated alongside the adsorption kinetics, isotherms, and thermodynamics. The results reveal that the highest adsorption capacity of methyl orange was obtained at pH 4.0. The adsorption process was well fitted by a pseudo-second-order kinetic model and the Langmuir isotherm model, and was spontaneous and endothermic. Through the Langmuir model, the maximal adsorption capacities of methyl orange were calculated as 495.0, 537.1 and 554.3 mg/g at 25.0, 35.0 and 45.0 °C, respectively. Subsequently, the adsorption mechanisms were elucidated by Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy investigations. It is indicated that electrostatic interactions, hydrogen bonding, π–π interactions and hydrophobic interactions between methyl orange and the composite microspheres were pivotal for the adsorption process. Finally, the regeneration studies demonstrated that after five adsorption–desorption cycles, the microspheres still maintained 93.6% of their initial adsorption capacity for methyl orange. This work not only presents a promising method for mitigating methyl orange pollution but also offers a sustainable approach to managing Palmer amaranth invasion.
Development of Ring-Expansion RAFT Polymerization of tert-Butyl Acrylate with a Cyclic Trithiocarbonate Derivative toward the Facile Synthesis of Cyclic Polymers
Authors: Motoyanagi Jin , Fujii Hiroki , Minoda Masahiko
Published: April 2024

Polymers with cyclic topology have no terminal structure and, therefore, exhibit various unique physical and functional properties compared to those of linear analogs. In this paper, we report an innovative methodology for the synthesis of cyclic polymers via ring-expansion RAFT (RE-RAFT) polymerization of vinyl monomers using a cyclic trithiocarbonate derivative (CTTC) as a RAFT agent. RE-RAFT of tert-butyl acrylate (TBA) was performed to yield a mixture of polymers exhibiting a bimodal size exclusion chromatography (SEC) trace. Both the peak top molecular weights shifted to higher-molecular-weight regions as the monomer conversion increased. The structure of the resulting polymer mixture was examined by 1H NMR and MALDI-TOF-MS. Detailed studies indicated that the obtained polymer of higher molecular weight was one of the large-sized cyclic polymers generated by the fusion of smaller-sized cyclic polymers during the RE-RAFT polymerization process. This approach opens the door to the simple synthesis of well-controlled cyclic polymers with complex structures, such as alternating and multi-block repeat unit sequences.