bluuebunny/crossref_metadata_2025 huggingface dataset:
Accuracy and Reliability of Grip Strength Measurements: A Comparative Device Analysis
Authors: Gränicher Pascale , Maurer Yael , Spörri Jörg , Haller Bernhard , Swanenburg Jaap , de Bie Rob A. , Lenssen Ton A. F. , Scherr Johannes
Published: December 2024

Background: Grip strength is widely used as a surrogate parameter for functional status. The current gold standard, the JAMAR® Hydraulic Dynamometer (JAMAR® Hydraulic), presents challenges for individuals with painful finger joints or low grip strength. Therefore, the objective of this observational study was to assess comparability across the JAMAR® Smart, the Martin Vigorimeter and the gold standard. Additionally, the intrasubject and intersession reliability of all three devices were examined, which are essential for quality control before generating normative data. Methods: Forty healthy participants (aged 37.0 ± 11.3 years) were included, and a subset of 20 participants was randomly selected for retesting. Grip strength testing involved five attempts per measurement device. Results: Intrasubject reliability was excellent (ICC3,1: 0.91–0.97), and a strong correlation (ICC3,1: 0.90–0.98) was found between the first attempt and the best of five as well as between the best of two or three attempts and the best of five, demonstrating robust reliability across multiple measures. Intersession reliability was good to excellent (ICC3,1: 0.85–0.97) across all three devices, which was confirmed by Bland–Altman analysis. The PCC (r) revealed moderate to very strong agreement with the current gold standard JAMAR® Hydraulic (r = 0.68–0.98), with increased differences between the Martin Vigorimeter and the JAMAR® Hydraulic measurements, particularly at low and high values. Conclusions: The proposed devices are suitable for test-retest analysis with 2–3 attempts. Despite high correlations between all three devices, the diverging levels of agreement between the Martin Vigorimeter and the established gold standard warrant caution against using these devices interchangeably.
Yes, I Can: The Interplay of Need for Cognition and Task Confidence in Cognitive Task Performance
Authors: Fleischhauer Monika , Schweitzer Felix M. , Enge Sören
Published: December 2024

Need for Cognition (NFC) refers to the enjoyment of and the search for intellectual challenges. Although numerous studies suggest associations between NFC and cognitive performance, the processes and factors that may mediate the relationship are not yet well understood. Based on the literature suggesting that self-efficacy (SE) expectancies mediate the relationship between NFC and cognitive performance, we sought to investigate this relationship systematically under controlled laboratory conditions. Additionally, we were interested in whether the visibility of the test subject’s performance to others (i.e., the experimenter) would influence these correlations. After an online questionnaire assessing NFC, 204 participants completed a set of highly demanding intelligence tasks in the laboratory. Following the sample tasks and prior to working through the task battery, task-specific SE about solving the tasks was assessed. To examine the role of visibility, participants either worked alone or were observed by the investigator while completing the tasks. We found a moderate positive association between NFC and task-specific SE, as well as a significant small positive association between NFC and task performance. Further analyses indicated that the relationship between NFC and task performance is fully mediated by task-specific SE, without any moderation effects related to the visibility of one’s own task performance to others. Our study suggests that the relationship between NFC and cognitive performance is also due to the positive influence of NFC on task-specific SE, which in turn influences cognitive performance.
Managerial Social Capital and Dividends: Evidence from the UK
Authors: Al-Bataineh Omar , Iqbal Abdullah , King Timothy
Published: December 2024

We examine the relationship between managerial social capital (MSC) and firms’ dividend policies. For an unbalanced panel of publicly listed UK FTSE 350 firms from 2006 to 2017, we find that MSC has a negative impact on a firm’s dividend policy. Firms pay lower dividends when a higher proportion of well-connected directors join corporate boards. Our main result is consistent with the notion that a high degree of social capital leads to better monitoring and control; therefore, social capital works under the substitution effect between governance quality and dividend payouts. In further analyses, we explore potential differences in this relationship between financial and non-financial firms and show that the association between MSC and dividend policy is weaker in financial firms than in non-financial firms. Taken together, our findings infer that investors should consider the social capital status of firms when they make investment decisions. Our results proved to be robust when subjected to a battery of tests, including alternative model specifications and definitions of MSC.
Assessment of Factors Affecting Tax Revenues: The Case of the Simplified Taxation System in the Russian Federation
Authors: Zakharova Kristina Alekseyevna , Muravyev Danil Anatolyevich , Karagulian Egine Araratovna , Baburina Natalia Alekseyevna , Degtyaryova Ekaterina Vladimirovna
Published: December 2024

The simplified tax system is the most common special tax regime in the Russian Federation in terms of the number of taxpayers. Tax revenues from the simplified tax system account for 6% of the structure of tax revenues of the consolidated budgets of the constituent entities of the Russian Federation and more than 93% of the structure of tax revenues from special tax regimes. The purpose of this study is to identify and assess the factors influencing tax revenues from the tax levied in connection with applying the simplified system of taxation (taxable object—income reduced by the amount of expenses). The objective of this study is to determine a set of factors used by economists to model the level of tax revenues and to conduct a corresponding econometric analysis of the influence of the selected factors on the dependent variable to identify characteristics of the simplified taxation system functioning in the Russian Federation. The object of this study is the per capita tax revenue from the tax levied in connection with applying the simplified system of taxation (the object of taxation is income reduced by expenses) in the Russian Federation. The subject of the research is a set of economic relations, which arise because of tax-legal relations between tax authorities and taxpayers in relation to the calculation of the tax levied in connection with the application of the simplified taxation system. This study’s hypothesis is that the amount of tax revenues is influenced by factors characterizing the economic situation and development of small and medium businesses in the constituent territories of the Russian Federation. This study was conducted in 83 constituent territories of the Russian Federation in 2020–2022. The research methods are statistical analysis and econometric modeling on panel data. During this study, six econometric models were constructed. Based on the results of specification tests, the least squares dummy variables model was selected. The results of the modeling show that the tax rate, the number of taxpayers, and the real average per capita monetary income of the population have a statistically significant impact on the per capita tax revenue under the simplified tax system (the object of taxation is income reduced by the number of expenses). As a result, the focus of economic policy at both macro and meso levels should be on the support of small and medium-sized enterprises in the early stages of their life cycle, as well as on the increase of the purchasing power of the population. Based on the results obtained, it is possible to forecast the revenue side of the budgets of the constituent entities of the Russian Federation.
Spatial–Temporal Changes and Driving Mechanisms of Ecological Environmental Quality in the Qinghai–Tibet Plateau, China
Authors: Shen Zhan , Gong Jian
Published: December 2024

This study examines the evolution of eco-environmental quality and its driving forces in the Qinghai-Tibet Plateau, with a particular focus on the Qinghai Lake region (QLR). By employing principal component analysis (PCA) on nearly 20 years of remote sensing data, we reveal the dynamic characteristics of ecological quality in this sensitive area. The results indicate that the ecological quality of the QLR has exhibited significant fluctuations over the past two decades, influenced by multiple factors such as climate change, human activities, and policy adjustments. Specifically, the fluctuations in ecological quality are closely associated with key ecological indicators, including the Normalized Difference Vegetation Index (NDVI), Land Surface Temperature (LST), Wetness Index (WET), and Normalized Differential Bare Soil Index (NDBSI). Vegetation cover and moderate humidity have substantial positive effects on ecological quality, while high temperatures and dry soil conditions exert negative impacts.
Application of Mixed-Integer Linear Programming Models for the Sustainable Management of Vine Pruning Residual Biomass: An Integrated Theoretical Approach
Authors: Nunes Leonel J. R.
Published: December 2024

Background: This study explores the use of Mixed-Integer Linear Programming (MILP) models to optimize the collection and transportation of vineyard pruning biomass, a crucial resource for sustainable energy and material production. Efficient biomass logistics play a key role in supporting circular bioeconomy principles by improving resource utilization and reducing operational costs. Methods: Two optimization approaches are evaluated: a base MILP model designed for scenarios with single processing points and an advanced model that incorporates intermediate processing steps to enhance logistical efficiency. The models were tested using synthetic datasets simulating vineyard regions to assess their performance. Results: The models demonstrated significant improvements, achieving cost reductions of up to 30% while enhancing operational efficiency and resource utilization. The study highlights the scalability and real-world applicability of the proposed models. Conclusions: The findings underscore the potential of MILP models in optimizing biomass supply chains and advancing circular bioeconomy goals. However, key limitations, such as computational complexity and adaptability to dynamic environments, are noted. Future research should focus on real-time data integration, dynamic updates, and multi-objective optimization to improve model robustness and applicability across diverse supply chain scenarios.
Fracture Toughness Behaviour of Nickel Alloy Steel 1.5662
Authors: Afzali Nariman , Stranghöner Natalie , Langenberg Peter
Published: December 2024

Nickel significantly increases the toughness of steel and makes it ideal for use in applications that require high impact and fracture resistance at low temperatures. These inherent advantages position nickel steel as indispensable material in various domains, with a pronounced presence in stationary Liquefied Natural Gas (LNG) tanks and in the shipbuilding industry, particularly for tanks in vessels intended for the transport of liquefied ethane and LNG. The presented study focuses on assessing the fracture toughness behaviour of nickel alloy steel 1.5662+QT640 under sub-zero and cryogenic temperatures. The fracture performance of the material was evaluated, specifically emphasizing the impact toughness and fracture toughness characteristics of the material. Moreover, it was discussed if the transferability of the experimental results to the well-known fracture mechanics-based concept of EN 1993-1-10, which relies on the master curve concept, is possible. The results show that the master curve concept is not applicable to the nickel alloy steel 1.5662+QT640 due to its exceptional fracture toughness behaviour at very low temperatures.
Forming Control and Wear Behavior of M2 High-Speed Steel Produced by Direct Energy Deposition on Curved Surface
Authors: Jiang Lan , Pan Xiaofang , Li Zhongkai , Yuan Bo , Liu Wenxin , Li Danya , Shen Ge , Liu Jun
Published: December 2024

Direct energy deposition (DED) technology shows promising applications in the production of roller die cutters. The optimization of process parameters, scanning strategies, and analyses of compressive properties and wear behavior are required prior to application. Therefore, this work investigated the influence of scanning strategy and overlap ratio on the microstructure, microhardness, compressive properties, and wear resistance of M2 high-speed steel (HSS) with DED on a 316 L cylindrical surface. The results reveal that along the deposition direction of the sample, the grain size gradually decreases, with hardness increasing from 187 HV in the matrix to 708 HV. As the overlap ratio increases, the grain size initially rises and then decreases, while hardness first declines and subsequently increases. The cross-scanning strategy effectively enhances the compressive strength by reducing porosity defects. Furthermore, the compressive strength of the samples initially increases with the overlap ratio before experiencing a slight decrease. The M-3 sample with a 50% overlap ratio exhibits the best compressive strength (3904 MPa). The wear rate decreases and then increases with the rising overlap ratio. Therefore, the M-3 sample, prepared using cross-scanning strategies with an overlap ratio of 50%, demonstrates a uniform and dense microstructure, resulting in superior wear resistance, and the wear rate is as low as 8 × 10−6 mm3·N−1·m−1. The current experimental results provide valuable references for the DED of die-cut knives.
Quality of Machined Surface and Cutting Force When Milling NiTi Alloys
Authors: Kowalczyk Małgorzata , Tomczyk Krzysztof
Published: December 2024

The machining of shape memory alloys, such as NiTi, presents challenges due to their specific physical, chemical, and mechanical properties. This study investigated the effect of the helix angle of milling tools—both uncoated and coated—on the cutting forces and the surface roughness of the milling process for a NiTi alloy. Experiments were conducted using the tools with and without coatings at various helix angles (20°, 30°, and 40°) and under different machining conditions. Optimization of the process was employed the Taguchi method to identify the best combination of the corresponding parameters. The results of the cutting force and the surface roughness measurements were analyzed and discussed in the context of optimizing the cutting conditions to achieve the desired outcomes. The results show that the lowest surface roughness values (Sa = 0.301 μm and Sz = 3.41 μm) were achieved with the coated tool at a helix angle of 30°, a feed per tooth of 0.02 mm, and a cutting speed of 45 m/min, while the lowest cutting force (F = 143.6 N) was observed with the coated tool at a cutting speed of 55 m/min, helix angle of 40°, and feed per tooth of 0.02 mm. This research provides valuable insights for industrial applications requiring the precise machining of NiTi in terms of the cutting forces and the surface quality. The findings reveal that the presence of the coating, along with an increase in the helix angle, significantly reduces the cutting forces, positively influencing the quality of the machined surface.
Adaptive Control of Pressure Difference in Abrasive Flow Machining for Inner Hole with High Depth/Diameter Ratio
Authors: Cai Yaojie , Qian Panyu , Wen Donghui , Jin Guixiang , Jin Mingsheng , Yuan Qiaoling , Zhang Li
Published: December 2024

To address the issue of uneven pressure distribution in the abrasive flow field within the inner hole of components with a large depth/diameter ratio, an adaptive control strategy for regulating flow field pressure difference is proposed in this paper. The strategy was based on the effects of pressure fluctuations at the abrasive flow inlet and outlet on pressure distribution patterns and pressure changes within the inner hole flow field, as derived from numerical simulations. An adaptive control fixture was also designed, enabling dynamic adjustments to the fixture gap, which significantly reduced the pressure difference in the flow field. Experimental results demonstrated that the surface texture uniformity of the inner hole was greatly improved after adaptive control. The non-uniformity in surface roughness after control was 59.1% lower compared to pre-control conditions, indicating improved machining consistency. Furthermore, the maximum reduction in surface roughness increased from 1.146 μm to 1.844 μm, and processing efficiency was notably enhanced.
The Buckling Behavior and Reliability Evaluation of a Cable-Stayed Bridge with Unique-Shaped Towers
Authors: Jia Yaoxiang , Ma Rujin , Zhou Xiaoyu , Wang Benjin
Published: December 2024

Buckling is a significant concern for cable-stayed bridges that incorporate a large number of steel components, particularly those featuring unique-shaped towers that require further examination due to the intricate internal force and stress distribution. This paper investigates the buckling behavior of a cable-stayed bridge with inverted V-shaped towers. The cable tower is characterized by its unique design that consists of diagonal bracings and columns in a compression-bending state. A finite element model is established for the nonlinear buckling analysis of the bridge, revealing that the buckling failure mode of the bridge mainly concerns the tower columns that bear large bending moments and axial compressions. The buckling safety factors are analyzed under different loading conditions and design parameters, including the stiffening rib thickness, the width-to-thickness ratio, and the initial cable forces. It indicates that the design optimization can be achieved by using smaller and thinner ribs while maintaining the buckling safety factor above the required level in design specifications. Furthermore, the reliability evaluation of buckling safety is considered using Monte Carlo simulations, which incorporates the long-term effects of corrosion on steel components. Based on the identified buckling failure modes and safety factors, it suggests that the buckling resistance of the bridge is sufficient, though it can be further enhanced by using high-strength weathering steel on critical parts. Additionally, maintenance interventions are shown to be highly beneficial in improving the life-cycle performance of the structure.
Nanocomposites Based on Iron Oxide and Carbonaceous Nanoparticles: From Synthesis to Their Biomedical Applications
Authors: Văduva Mirela , Nila Andreea , Udrescu Adelina , Cramariuc Oana , Baibarac Mihaela
Published: December 2024

Nanocomposites based on Fe3O4 and carbonaceous nanoparticles (CNPs), including carbon nanotubes (CNTs) and graphene derivatives (graphene oxide (GO) and reduced graphene oxide (RGO)), such as Fe3O4@GO, Fe3O4@RGO, and Fe3O4@CNT, have demonstrated considerable potential in a number of health applications, including tissue regeneration and innovative cancer treatments such as hyperthermia (HT). This is due to their ability to transport drugs and generate localized heat under the influence of an alternating magnetic field on Fe3O4. Despite the promising potential of CNTs and graphene derivatives as drug delivery systems, their use in biological applications is hindered by challenges related to dispersion in physiological media and particle agglomeration. Hence, a solid foundation has been established for the integration of various synthesis techniques for these nanocomposites, with the wet co-precipitation method being the most prevalent. Moreover, the dimensions and morphology of the composite nanoparticles are directly correlated with the value of magnetic saturation, thus influencing the efficiency of the composite in drug delivery and other significant biomedical applications. The current demand for this type of material is related to the loading of a larger quantity of drugs within the hybrid structure of the carrier, with the objective of releasing this amount into the tumor cells. A second demand refers to the biocompatibility of the drug carrier and its capacity to permeate cell membranes, as well as the processes occurring within the drug carriers. The main objective of this paper is to review the synthesis methods used to prepare hybrids based on Fe3O4 and CNPs, such as GO, RGO, and CNTs, and to examinate their role in the formation of hybrid nanoparticles and the correlation between their morphology, the dimensions, and optical/magnetic properties.
Experimental Study on the Flexural Performance of Composite Beams with Lipped Channels
Authors: Lee Changyong , Bae Byungho , Kim Seunghun , Kim Taesoo
Published: December 2024

This study conducted experiments to investigate the flexural behavior of steel–concrete composite beams with U-shaped sections, utilizing cold-formed lipped channels as web components. To enhance both flexural and shear performance, trapezoidal plates were added to the lower sides of the composite beams. A total of ten specimens were fabricated, with variables defined according to the following criteria: presence of bottom tension reinforcement and bottom studs, thickness of the trapezoidal side plates (6 mm and 8 mm), and the welding method. Four-point bending tests were conducted, and all specimens exhibited typical flexural failure at the ultimate state. Specimens with bottom tension reinforcement, specifically those in the H5-T6 and H5-T8 series, demonstrated increases in ultimate load of 28.8% and 33.5%, respectively, compared to specimens without tension reinforcement. The use of lipped channels enabled full composite action between the concrete and the steel web components, eliminating the need for stud anchors. Additionally, it was confirmed that the plastic neutral axis, reflecting the material test strengths, was located within the concrete slab as intended. This study also compared the design flexural strengths, calculated using the yield stress distribution method from structural steel design standards such as AISC 360 and KDS 14, with the experimental flexural strengths. The comparison was used to evaluate the applicability of current design standards.
A Wide Passband Frequency-Selective Surface with a Sharp Roll-Off Band Using the Filtering Antenna-Filtering Antenna Method
Authors: Ren Yanfei , Xi Zhenghu , Liu Qinqin , Gong Jiayi , Sun Zhiwei , Sima Boyu
Published: December 2024

Frequency-selective surfaces (FSSs) have attracted great attention owing to their unique feature to manipulate transmission performance over the frequency domain. In this work, a filtering antenna-filtering antenna (FA-FA) FSS with a wide passband and double-side sharp roll-off characteristics is presented by inter-using the filtering antenna and receiving–transmitting metasurface methods. First, a dual-polarized filtering antenna element was designed by employing a parasitic band-stop structure with an L-probe feed. Then, the FA-FA-based FSS unit was constructed by placing two such filtering antennas back to back, with their feedings connected through metallic vias. Finally, the FSS with a wide passband and high selectivity was realized by arraying the FA-FA units periodically. The full-wave simulation results demonstrated that the designed FA-FA-based FSS had a wide passband from 13.06 GHz to 14.46 GHz with a flat in-band frequency response. The lower and upper roll-off bandwidths were sharp, reaching 1% and 1.2% of the center frequency. The proposed FA-FA-based FSS was fabricated and measured, achieving the coincident performance according to the theoretical prediction. The wideband band-pass FSS obtained a sharp double-side roll-off feature, which can be applied in various studies such as an antenna array, metasurface, communication, etc.
Assessment of the Structural Integrity of the Portal Crane Elements After Long-Term Operation
Authors: Dzioba Ihor , Zvirko Olha , Pała Robert , Oliynyk Oleksandr
Published: December 2024

Evaluating the current technical condition and residual life of structures that may have reached or exceeded the end of their design life is a challenging issue in many industrial sectors. This paper focuses on the assessment of the structural integrity of structural elements of a seaport portal crane after operation for about 33 years. Test specimens were extracted from two crane elements, a jib (element A) as the most seriously loaded unit and, for comparison, a boom (element B) as the less loaded one, and machined in two different orientations, longitudinal and transversal. Both crane elements were made of a low-carbon rolled steel. The analysis was performed according to the FAD approach of FITNET Procedures. The basic level of analysis was used. For this purpose, the strength and fracture toughness characteristics of the steel from tested elements were determined experimentally. The strength and plasticity properties of the steel of both elements were similar. At the same time, the fracture toughness characteristics differ for the elements A and B and for the longitudinal and transverse specimen directions. The results of the FAD (FITNET) analysis performed for the elements containing a central crack loaded by tensile stress showed that they are not susceptible to failure. The relative length of cracks for which the critical state will be reached is also estimated.
Theoretical Investigation of Single-Atom Catalysts for Hydrogen Evolution Reaction Based on Two-Dimensional Tetragonal Mo3C2
Authors: Xue Bo , Zeng Qingfeng , Yu Shuyin , Su Kehe
Published: December 2024

Developing highly efficient and cost-competitive electrocatalysts for the hydrogen evolution reaction (HER), which can be applied to hydrogen production by water splitting, is of great significance in the future of the zero-carbon economy. Here, by means of first-principles calculations, we have scrutinized the HER catalytic capacity of single-atom catalysts (SACs) by embedding transition-metal atoms in the C and Mo vacancies of a tetragonal Mo3C2 slab, where the transition-metal atoms refer to Ti, V, Cr, Mn, Fe, Co, Ni and Cu. All the Mo3C2-based SACs exhibit excellent electrical conductivity, which is favorable to charge transfer during HER. An effective descriptor, Gibbs free energy difference (ΔGH*) of hydrogen adsorption, is adopted to evaluate catalytic ability. Apart from SACs with Cr, Mn and Fe located at C vacancies, all the other SACs can act as excellent catalysts for HER.
Off-Stoichiometry Thiol-Ene Surface Functionalization: Example with Gold Nanoparticles
Authors: Ruska Rihards , Sarakovskis Anatolijs , Zutis Edmunds , Paidere Gunita , Vozny Igor , Cipa Janis , Gabrusenoks Jevgenijs , Freimanis Toms , Zalubovskis Raivis , Anspoks Andris
Published: December 2024

Surface modification is essential in microfluidic applications due to the inherent hydrophobicity of polymers, which can lead to biofouling and reagent denaturation. Despite the development, challenges such as hydrophobic molecule absorption and limitations in scaling are still present. Off-stoichiometry thiol-ene (OSTE) materials have emerged as a promising alternative, offering advantages like rapid prototyping, minimal hydrophobic absorption, and customizable surface chemistries. While the thiol-ene polymerization mechanism is well understood, the fundamental understanding of thiol group binding on OSTE surfaces remains limited. Existing techniques to analyze surface groups lack the capability to confirm the stable presence of thiol groups on the surface. In our study, using Raman and X-ray photoelectron spectroscopy techniques, we investigated a potential method for enhancing the surface properties of OSTE polymer—the attachment of novel linkers to the surface. We have demonstrated our synthesized compound efficiency by binding gold nanoparticles to the OSTE surface. Our findings indicate that chemical reactions involving double bonds with the material surface hold the most potential for effective surface modification for gold binding.
Enhanced Gaussian Process Model for Predicting Compressive Strength of Ultra-High-Performance Concrete (UHPC)
Authors: Zou Zhipeng , Peng Bin , Xie Lianghai , Song Shaoxun
Published: December 2024

Ultra-high-performance concrete (UHPC) is widely used in engineering due to its exceptional mechanical properties, particularly compressive strength. Accurate prediction of the compressive strength is critical for optimizing mix proportions but remains challenging due to data dispersion, limited data availability, and complex material interactions. This study enhances the Gaussian Process (GP) model to address these challenges by incorporating Singular Value Decomposition (SVD) and Kalman Filtering and Smoothing (KF/KS). SVD improves data quality by extracting critical features, while KF/KS reduces data dispersion and align prediction with physical laws. The enhanced GP model predicts compressive strength with improved accuracy and quantifies uncertainty, offering significant advantages over traditional methods. The results demonstrate that the enhanced GP model outperforms other models, including artificial neural networks (ANN) and regression models, in terms of reliability and interpretability. This approach provides a robust tool for optimizing UHPC mix designs, reducing experimental costs, and ensuring structural performance.
The Biomechanics of Nickel Titanium Instrument Fracture in Root Canal Therapy: A Narrative Review
Authors: Ohri Kushagra , Chien Philip Yuan-Ho , Peters Ove Andreas
Published: December 2024

The use of motorized nickel titanium instruments is an essential component in contemporaneous clinical endodontics. The mechanical properties of nickel titanium are optimal for the cleaning and shaping of root canal systems. However, instrumentation carries risks, particularly instrument fracture, which may become an obstacle to achieving adequate disinfection of the canal system. Although the biomechanics of instrument fracture have been extensively investigated previously, certain facets remain unexplored, specifically torsional fatigue. This review presents a comprehensive overview of the modern understanding of the biomechanics involved in nickel titanium instrument fracture. Importantly, while research has tended to describe fatigue fracture and torsional failure as distinct and separate entities, clinical conditions are likely a combination of the two. Moreover, intracanal instrument fractures may also occur following a different mechanism, torsional fatigue. This should be taken into consideration for further research and clinical guidance.
Transcranial Direct Current Stimulation to Provide Neuroprotection and Enhance Cerebral Blood Flow in Stroke: A Comprehensive Review
Authors: Gunduz Muhammed Enes , Kocahasan Melike , Keser Zafer
Published: December 2024

Stroke remains a leading cause of global disability and mortality despite advancements in acute interventions. Transcranial direct current stimulation (tDCS), a non-invasive neuromodulation technique, has primarily been studied for its effects on cortical excitability, with limited exploration of its neuroprotective and hemodynamic benefits. This review examines the role of tDCS in stroke, with a focus on neuroprotection in acute settings and cerebral blood flow (CBF) modulation in both acute and chronic phases. tDCS offers rapid, localized delivery to salvageable ischemic tissue, exerting pleiotropic effects that address a broader spectrum of pathological processes compared to pharmacological agents. Cathodal tDCS shows promise in acute ischemic stroke for neuroprotection in small-scale clinical studies, enhancing CBF and promoting vessel recanalization, while anodal tDCS demonstrates stronger effects on CBF, particularly in chronic stroke and hypoperfusion cases. Bihemispheric stimulation may offer additional benefits, with evidence suggesting a dose-dependent relationship between stimulation parameters and therapeutic outcomes. Further research is warranted to optimize stimulation protocols, evaluate safety and feasibility, and explore the potential of tDCS to promote neuroplasticity and functional recovery across different stroke populations and stages. By addressing these gaps, tDCS could emerge as a valuable adjunctive therapy in stroke management, complementing current interventions and expanding therapeutic windows.
Effectiveness of Physical Activity in the Management of Nonspecific Low Back Pain: A Systematic Review
Authors: Alonso-Sal Alexandra , Alonso-Perez José Luís , Sosa-Reina María Dolores , García-Noblejas-Fernández Juan Antonio , Balani-Balani Viren Gul , Rossettini Giacomo , Villafañe Jorge Hugo
Published: December 2024

Background and Objectives: This systematic review evaluates the effectiveness of exercise interventions for managing nonspecific low back pain (NSLBP) and explores their impact on related biopsychosocial factors, physical health variables, and inflammatory biomarkers. Materials and Methods: A comprehensive search of five databases (PubMed, CINAHL, PEDro, SCOPUS, Cochrane Library) was conducted, covering studies from 2019 to 2024. Fifteen randomized controlled trials involving 1338 participants aged 18 to 65 years with NSLBP were included. Data extraction and quality assessment were performed independently by two reviewers using the PEDro scale, and risk of bias was evaluated using the Cochrane Risk-of-Bias tool (RoB 2.0). Results: Exercise significantly reduced pain intensity and improved biopsychosocial factors such as depression, disability, functionality, quality of life, and kinesiophobia. Additionally, it enhanced physical parameters like proprioception, muscle thickness, and physical performance. However, the review found insufficient evidence regarding the effects of exercise on inflammatory biomarkers in NSLBP patients. Conclusions: The findings suggest that physical exercise is an effective intervention for pain reduction and the improvement of overall health in NSLBP, though further research is needed to clarify its impact on inflammation.
Interventions Targeting Insulin Resistance in Patients with Type 1 Diabetes: A Narrative Review
Authors: Herascu Andreea , Avram Vlad-Florian , Gaita Laura , Alexandra Sima , Reurean-Pintilei Delia-Viola , Timar Bogdan
Published: December 2024

Background and Objectives: Insulin resistance (IR) is the most important factor involved in the pathogenesis of type 2 diabetes but may also develop in type 1 diabetes (T1DM). Developing IR in patients with T1DM may generate a burden in achieving glycemic targets and may deteriorate the overall prognosis. This review aims to describe the pathogenesis of IR in T1DM, summarize the common associations of IR with other conditions in patients with T1DM, describe the consequences of developing IR in these patients, and present the interventions that target IR in people with T1DM. Results: The occurrence of IR in T1DM is multifactorial; however, it is frequently linked to overweight or obesity and sedentary lifestyle. Besides impairments in glycemic control and increased insulin requirements, the presence of IR is associated with an increased cardiovascular risk in patients with T1DM. Considering that patients with T1DM are insulin-treated, IR may be evaluated only using surrogate biomarkers, the most frequently used being the estimated glucose disposal rate. The most important interventions that are shown to be feasible in improving insulin sensitivity in patients with T1DM are lifestyle optimizations, including nutrition therapy or physical activity and pharmacotherapy with metformin, sodium-glucose cotransporter-2 inhibitors, glucagon-like peptide-1 receptor agonists, and thiazolidinediones. Conclusions: Targeting the improvement of IR in patients with T1DM is a key element in achieving optimal glycemic control, as well as improving the overall patient’s prognosis besides glycemic control.
Recent Developments in Electrospun Nanofiber-Based Triboelectric Nanogenerators: Materials, Structure, and Applications
Authors: Wei Qinglong , Cao Yuying , Yang Xiao , Jiao Guosong , Qi Xiaowen , Wen Guilin
Published: December 2024

Triboelectric nanogenerators (TENGs) have garnered significant attention due to their high energy conversion efficiency and extensive application potential in energy harvesting and self-powered devices. Recent advancements in electrospun nanofibers, attributed to their outstanding mechanical properties and tailored surface characteristics, have meant that they can be used as a critical material for enhancing TENGs performance. This review provides a comprehensive overview of the developments in electrospun nanofiber-based TENGs. It begins with an exploration of the fundamental principles behind electrospinning and triboelectricity, followed by a detailed examination of the application and performance of various polymer materials, including poly (vinylidene fluoride) (PVDF), polyamide (PA), thermoplastic polyurethane (TPU), polyacrylonitrile (PAN), and other significant polymers. Furthermore, this review analyzes the influence of diverse structural designs—such as fiber architectures, bionic configurations, and multilayer structures—on the performance of TENGs. Applications across self-powered devices, environmental energy harvesting, and wearable technologies are discussed. The review concludes by highlighting current challenges and outlining future research directions, offering valuable insights for researchers and engineers in the field.
Investigation of Surface Hardness and Microstructural Changes in S45C Carbon Steel Cylinders Through Arc Quenching
Authors: Son Minh Pham , Nguyen Van-Thuc , Nguyen Thanh Tan , Ho Nguyen
Published: December 2024

Arc quenching has many advantages, including generating large amounts of heat in a short time, a self-quenching ability, and simple equipment. The electric arc energy from a TIG welding machine was used to modify the surface properties of S45C Carbon Steel Cylinders. The study focuses on the impact of arc length, current intensity, travel speed, gas flow rate, heating angle, and pulse on surface hardness after arc quenching an S45C steel tube with a cylinder surface. The study found that the hardness reduces from 45.1 HRC to 41.2 HRC as the current intensity increases from 125 A to 140 A. According to Taguchi’s results, the ranking of factors which have the greatest impact on surface hardness are pulse time, travel speed, intensity, gas flow rate, arc length, and heating angle. The pulse time has the highest impact because it directly influences the heating input, followed by the travel speed. Arc length and heating angle, on the other hand, have the least effect. The base metal, heat-affected area, and hardened area are the three distinct areas that make up the microstructure structure. After the arc quenching process, the case hardening depth is represented by the heat-affected zone at 1536 μm. A highly colored residual austenite and a needle-shaped martensite phase make up the hardened region. The hardened region is 1200 μm thick and has a hardness of more than 300 HV0.3. The study’s findings may improve the application and understanding of the arc quenching treatment procedure in the industrial sector.
Chemical Diversity of Mediterranean Seagrasses Volatilome
Authors: Coquin Salomé , Ormeno Elena , Pasqualini Vanina , Monnier Briac , Culioli Gérald , Lecareux Caroline , Fernandez Catherine , Saunier Amélie
Published: December 2024

Background/Objectives: Biogenic volatile organic compounds (BVOCs), extensively studied in terrestrial plants with global emissions around 1 PgC yr−1, are also produced by marine organisms. However, benthic species, especially seagrasses, are understudied despite their global distribution (177,000–600,000 km2). This study aims to examine BVOC emissions from key Mediterranean seagrass species (Cymodocea nodosa, Posidonia oceanica, Zostera noltei, and Zostera marina) in marine and coastal lagoon environments. Methods: BVOCs were collected using headspace solid-phase microextraction (HS-SPME) using divinylbenzene/carboxen/polydimethylsiloxane (DVB/CAR/PDMS) fibers and analyzed by gas chromatography–mass spectrometry (GC-MS). Results: An important chemical diversity was found with a total of 92 volatile compounds (61 for Z. noltei, 59 for C. nodosa, 55 for P. oceanica, and 51 for Z. marina), from different biosynthetic pathways (e.g., terpenoids, benzenoids, and fatty acid derivatives) and with several types of chemical functions (e.g., alkanes, esters, aldehydes, and ketones) or heteroatoms (e.g., sulfur). No differences in chemical richness or diversity of compounds were observed between species. The four species shared 29 compounds enabling us to establish a specific chemical footprint for Mediterranean marine plants, including compounds like benzaldehyde, benzeneacetaldehyde, 8-heptadecene, heneicosane, heptadecane, nonadecane, octadecane, pentadecane, tetradecane, and tridecanal. PLS-DA and Heatmap show that the four species presented significantly different chemical profiles. The major compounds per species in relative abundance were isopropyl myristate for C. nodosa (25.6%), DMS for P. oceanica (39.3%), pentadecane for Z. marina (42.9%), and heptadecane for Z. noltei (46%). Conclusions: These results highlight the potential of BVOCs’ emission from seagrass ecosystems and reveal species-specific chemical markers.
Mediating Effects of Serum Lipids and Physical Activity on Hypertension Management of Urban Elderly Residents in China
Authors: Zhao Yang , Zhang Yike , Wang Fei
Published: December 2024

Background/Objectives: Investigating the importance and potential causal effects of serum lipid biomarkers in the management of hypertension is vital, as these factors positively impact the prevention and control of cardiovascular disease (CVD). Methods: We surveyed 3373 urban residents using longitudinal data from the CHARLS database, collected between 2015 and 2020. Pearson correlation methods were employed to explore the relationships among the numerical variables. A logistic regression model was utilized to identify the risk factors for hypertension. The dose–effect relationship between serum lipids and BP was assessed using restricted cubic splines (RCS). Additionally, piecewise structural equation modeling (PiecewiseSEM) was conducted to further elucidate the direct and indirect pathways involving individual body indices, serum lipids, and PA on BP responses at different levels of physical activity (PA). Results: The four serum lipids showed significant differences between hypertensive and non-hypertensive residents (p < 0.05). All lipids, except for HDL cholesterol, demonstrated extremely significant positive correlations with both systolic blood pressure (SBP) and diastolic blood pressure (DBP) (p < 0.001). All serum lipid variables were significantly associated with the incidence of hypertension. Specifically, triglycerides (bl_tg), HDL (bl_hdl), and low-density lipoprotein LDL cholesterol were identified as significant risk factors, with odds ratios (ORs) of 1.56 (95% CI: 1.33–1.85, p < 0.001), 1.16 (95% CI: 1.02–1.33, p < 0.05), and 1.62 (95% CI: 1.23–2.15, p < 0.001), respectively. Conversely, cholesterol (bl_cho) was a protective factor for hypertension, with an OR of 0.60 (95% CI: 0.42–0.82, p < 0.01). PA showed weak relationships with blood pressure (BP); however, PA levels had significant effects, particularly at low PA levels. The four serum lipids had the most mediating effect on BP, especially under low PA level conditions, while PA exhibited a partly weak mediating effect on BP, particularly under high PA level conditions. Conclusions: Serum lipids have significant nonlinear relationships with BP and PA levels exert different influences on BP. The significant mediating effects of serum lipids and the weak mediating effects of PA on individual body indices related to SBP and DBP demonstrate significant differences across varying levels of PA, highlighting the importance of low PA levels in hypertension management. This study could provide valuable recommendations and guidance in these areas.
Development of Piezoelectric Inertial Rotary Motor for Free-Space Optical Communication Systems
Authors: Šišovas Laurynas , Čeponis Andrius , Mažeika Dalius , Borodinas Sergejus
Published: December 2024

This paper presents the design, development, and investigation of a novel piezoelectric inertial motor whose target application is the low Earth orbit (LEO) temperature conditions. The motor utilizes the inertial stick–slip principle, driven by the first bending mode of three piezoelectric bimorph plates, and is compact and lightweight, with a total volume of 443 cm3 and a mass of 28.14 g. Numerical simulations and experimental investigations were conducted to assess the mechanical and electromechanical performance of the motor in a temperature range from −20 °C to 40 °C. The results show that the motor’s resonant frequency decreases from 12,810 Hz at −20 °C to 12,640 Hz at 40 °C, with a total deviation of 170 Hz. The displacement amplitude increased from 12.61 μm to 13.31 μm across the same temperature range, indicating an improved mechanical response at higher temperatures. The motor achieved a maximum angular speed up to 1200 RPM and a stall torque of 13.1 N·mm at an excitation voltage amplitude of 180 Vp-p. The simple and scalable design, combined with its stability under varying temperature conditions, makes it well suited for small satellite applications, particularly in precision positioning tasks such as satellite orientation and free-space optical (FSO) communications.
High-Efficiency Precision Polishing Using Fiber Brush–Shear-Thickening Fluid Composites
Authors: Gong Zepeng , Jin Yaodong , Cao Qianqian , Dong Xiaoxing , Shi Yongjie , Huang Fengli , Li Lujuan , Piao Zhongyu
Published: December 2024

Shear-thickening fluid (STF) is widely applied in various practical engineering fields due to its rheological properties of increased viscosity under load. We investigated the integration of STF with fiber brushes to prepare a novel composite material for polishing applications. The impact of composite material properties is studied in surface finish, specifically roughness and morphology, across flat and uneven surfaces. The effects of the critical variables, including polishing speed, feed depth, and STF concentration, are analyzed through experimentation and simulation. After the STF polishing, the surface roughness of the aluminum alloy sample decreases from 3.125 μm to 0.528 μm, which increases the processing efficiency by 40% compared to Newton polishing slurry. The unique shear-thickening performance of the composite material ensures excellent surface quality and high efficiency in the precision machining of workpieces.