bluuebunny/crossref_metadata_2025 huggingface dataset:
A Review on Friction Stir Welding of High-Strength Al-Zn-Mg Alloy: Insights on Second-Phase Particles
Authors: Wang Keqi , Naumov Anton , Panchenko Evgenii , Panchenko Oleg
Published: October 2024

The friction stir welding (FSW) process is a unique combination of deformation and high temperature, which provides opportunities to modify microstructures through the adjustment of the processing parameters and is an ideal way to join non-weldable aluminum alloys by avoiding the formation of a molten pool. The 7xxx series heat-treatable aluminum alloys are widely used in the aerospace field as high-performance structural materials. The microstructure evolution and mechanical performance of these alloys are affected by the effects of thermomechanical processing, which provides opportunities to optimize the material properties by controlling microstructural features such as intermetallic constituent particles, dispersoids and nanoscale precipitates. This paper focuses on the basic principles of the thermal and mechanical effects generated during FSW on the evolution of second-phase particles in different zones of the weld.
Bandgap Characteristics of Boron-Containing Nitrides—Ab Initio Study for Optoelectronic Applications
Authors: Strak Pawel , Gorczyca Iza , Teisseyre Henryk
Published: October 2024

Hexagonal boron nitride (h-BN) is recognized as a 2D wide bandgap material with unique properties, such as effective photoluminescence and diverse lattice parameters. Nitride alloys containing h-BN have the potential to revolutionize the electronics and optoelectronics industries. The energy band structures of three boron-containing nitride alloys—BxAl1−xN, BxGa1−xN, and BxIn1−xN—were calculated using standard density functional theory (DFT) with the hybrid Heyd–Scuseria–Ernzerhof (HSE) function to correct lattice parameters and energy gaps. The results for both wurtzite and hexagonal structures reveal several notable characteristics, including a wide range of bandgap values, the presence of both direct and indirect bandgaps, and phase mixing between wurtzite and hexagonal structures. The hexagonal phase in these alloys is observed at very low and very high boron concentrations (x), as well as in specific atomic configurations across the entire composition range. However, cohesive energy calculations show that the hexagonal phase is more stable than the wurtzite phase only when x > 0.5, regardless of atomic arrangement. These findings provide practical guidance for optimizing the epitaxial growth of boron-containing nitride thin films, which could drive future advancements in electronics and optoelectronics applications.
Flammability and Mechanical Testing of Sandwich Composite for Rolling Stock Structural Applications
Authors: Kalinowski Marcin , Szczepanik Mirosław , Szymiczek Małgorzata
Published: October 2024

Components made of composite materials are being increasingly used in the construction of rolling stock. Currently, the use of components made of composite materials as train structural elements is increasingly being considered. Non-structural components made of composites are most often found inside rail vehicles (e.g., the interior lining), while structural components made of sandwich composite materials can be used for the roof, sidewalls, and underframe constructions. This article provides a description of an innovative sandwich composite developed for a metro’s underframe, as well as the production process and preparation of the composite specimens. The main parts of the work are flammability and mechanical (static and fatigue) tests of the innovative sandwich composite. The scope of the flammability tests included the testing of the fire properties using the radial plate method, the optical density of smoke, and the content of toxic gases. The mechanical strength of the sandwich composite was examined during a flexural (three-point bending) test and a fatigue strength under a given dynamic load. The results presented in the article are very significant, both in terms of flammability and the mechanical strength tests. In order to produce large-size train components, appropriately large patches of component layers of the composite are required; this may pose production problems.
Investigation of Effect of Part-Build Directions and Build Orientations on Tension–Tension Mode Fatigue Behavior of Acrylonitrile Butadiene Styrene Material Printed Using Fused Filament Fabrication Technology
Authors: El-Deeb Ibrahim S. , Grabowik Cezary , Esmael Ehssan , Nabhan Ahmed , Rashad Maher , Ebied Saad
Published: October 2024

This article explores the fatigue characteristics of acrylonitrile butadiene styrene (ABS) components fabricated using fused filament fabrication (FFF) additive manufacturing technology. ABS is frequently used as a polymeric thermoplastic material in open-source FFF machines for a variety of engineering applications. However, a comprehensive understanding of the mechanical properties and execution of FFF-processed ABS components is necessary. Currently, there is limited knowledge regarding the fatigue behavior of ABS components manufactured using FFF AM technology. The primary target of this study is to evaluate the results of part-build directions and build orientation angles on the tensile fatigue behavior exhibited by ABS material. To obtain this target, an empirical investigation was carried out to assess the influence of building angles and orientation on the fatigue characteristics of ABS components produced using FFF. The test samples were printed in three distinct directions, including Upright, On Edge, and Flat, and with varying orientation angles ([0°, 90°], [15°, 75°], [30°, 60°], [45°]), using a 50% filling density. The empirical data suggest that, at each printing angle, the On-Edge building orientation sample exhibited the most prolonged vibrational duration before fracturing. In this investigation, we found that the On-Edge printing direction significantly outperformed the other orientations in fatigue life under cyclic loading with 1592 loading cycles when printed with an orientation angle of 15°–75°. The number of loading cycles was 290 and 39 when printed with the same orientation angle for the Flat and Upright printing directions, respectively. This result underscores the importance of orientation in the mechanical performance of FFF-manufactured ABS materials. These findings enhance our comprehension of the influence exerted by building orientation and building angles on the fatigue properties of FFF-produced test samples. Moreover, the research outcomes supply informative perspectives on the selection of building direction and building orientation angles for the design of 3D-printed thermoplastic components intended for fatigue cyclic-loading applications.
A Bio-Chemo-Hydro-Mechanical Model for the Simulation of Biocementation in Soils: One-Dimensional Finite Element Simulations
Authors: Terra Victor Scartezini , Simões Fernando M. F. , Cardoso Rafaela
Published: October 2024

Microbially induced calcite precipitation is a soil improvement technique in which bacteria are used to produce calcium carbonate (biocement), precipitated after the hydrolysis of urea by the urease enzyme present in the microorganisms. This technique is becoming popular, and there have been several real cases of its use; however, the dosages and reaction times used to attain a required percentage of biocement mainly stem from previous experimental tests, and calculations are not performed. Thus, it is fundamental to have more robust tools and the existence of numerical models able to compute the amount precipitated, such as the one proposed in this paper, can be an important contribution. A two-phase porous medium model is created to analyse the precipitation process. The solid phase contains soil particles, bacteria and biocement, while the fluid phase contains water, urea and other dissolved species. A coupled bio-chemo-hydro-mechanical finite element formulation is defined, embodying the biochemical reaction, water seepage, the diffusion of species and soil deformation. The main novelties of this study are as follows: (i) porosity changes are computed considering the generation of solid mass due to biocement precipitation, and, therefore, soil permeability is updated during the calculation, with these highly coupled equations being integrated in time simultaneously and not sequentially; and (ii) the model is calibrated with experimental tests conceived especially for this purpose. The model is then used to compute the biocement precipitated in a sand column simulating a real experimental test. The results of the simulations present a distribution of biocement along the column closer to that observed in the experimental tests, validating the model.
Handgrip Strength and Cognitive Recovery in Older Stroke Survivors: A Prospective Study
Authors: Choi Young-Ah
Published: October 2024

Background and Objectives: Handgrip strength (HGS) is an important indicator of overall physical capability and is linked to various health outcomes in older adults. Despite extensive research on the relationship between HGS and cognitive decline, longitudinal studies on poststroke cognitive changes in relation to HGS are scarce. This study aimed to observe whether HGS at discharge from acute stroke rehabilitation affects cognitive function 6–12 months after stroke onset and to compare cognitive outcomes between patients with normal and low HGS at discharge. Materials and Methods: This prospective cohort study was conducted in the Department of Rehabilitation Medicine at a tertiary care hospital. In agreement with the Asian Working Group for Sarcopenia 2019 criteria, low muscle strength was defined as an HGS of less than 28 kg for men and less than 18 kg for women, and participants were categorized into normal and low HGS groups. Neuropsychological evaluations were conducted before discharge (approximately one month after stroke onset) and between 6 and 12 months after stroke onset. Results: The low HGS group was older and had lower Montreal Cognitive Assessment scores. However, after adjusting for covariates, the linear mixed model analysis showed no significant differences between the groups in global cognition or specific cognitive domains, except for psychomotor speed during the subacute phase. Notable improvements in language ability were observed in both groups over time, while significant improvements in executive function were observed exclusively in the low HGS group. Conclusions: This longitudinal study is the first to explore the relationship between HGS and changes in cognitive function in older adults with stroke, providing insights into physical strength and cognitive recovery during stroke rehabilitation.
Effect of Sarcopenia on Functional Recovery in Acute Stroke Patients Admitted for Standard Rehabilitation Program
Authors: Kim So-Yeong , Cho Woon-Su , Park Chi-Bok , Kim Byeong-Geun
Published: October 2024

Background and Objectives: Sarcopenia is a significant concern in stroke rehabilitation, with a high prevalence reported in acute stroke patients. This study examines the effect of sarcopenia on rehabilitation outcomes in acute stroke patients. Materials and Methods: This study was conducted with acute stroke patients admitted within 90 days of onset to the rehabilitation hospital. Participants were divided into a stroke with sarcopenia group and a stroke without sarcopenia group. Evaluations were conducted at baseline, 4 weeks, and 8 weeks, including the following assessments: manual muscle testing (MMT), Berg Balance Scale (BBS), functional ambulation category (FAC), and Modified Barthel Index (MBI). Both groups received an identical rehabilitation program for 8 weeks. Results: Significant within-group improvements were observed in both groups across all measures (p < 0.05). However, the stroke with sarcopenia group showed significantly less improvement in MMT, BBS, FAC, and MBI compared to the stroke without sarcopenia group at both 4 and 8 weeks (p < 0.05). Conclusions: These results underscore the significant impact of sarcopenia on functional recovery in stroke patients, despite both groups receiving identical rehabilitation programs. The presence of sarcopenia was a critical predictor of poorer outcomes in muscle strength, balance, ambulation, and activities of daily living. Given these findings, specific rehabilitation strategies targeting sarcopenia are needed to improve recovery in stroke patients. Future research should include larger sample sizes, longer follow-ups, and sarcopenic patient-specific rehabilitation programs.
Rehabilitation for Patients with COVID-19-Associated Acute Respiratory Distress Syndrome During Quarantine: A Single-Center Experience
Authors: Jang Myung Hun , Shin Yong Beom , Shin Ho Jeong , Jeong Eunsuk , Kim Saerom , Yoo Wanho , Jang Hyojin , Lee Kwangha
Published: October 2024

Background and Objectives: In this study, we evaluated clinical factors associated with implementing a rehabilitation program for patients with COVID-19-associated acute respiratory distress syndrome (ARDS) requiring mechanical ventilation (MV) during the quarantine period. Materials and Methods: This observational study was conducted in the National Designated Isolated ICU, a dedicated COVID-19 center with 18 beds, from 30 December 2020 to 30 May 2022. One hundred and fifty-four patients (mean age: 67.3 ± 13.4 years; male: 59.7%) were enrolled. The ICU rehabilitation program included early mobilization, chest physiotherapy, and dysphagia treatment. Results: Forty-five patients (29.3%) participated in the rehabilitation program. Multivariate logistic regression identified three significant factors: tracheostomy (odds ratio [OR], 2.796; 95% confidence interval [CI], 1.238–6.316; p = 0.013), body mass index ≥ 25.0 kg/m2 (OR, 2.724; 95% CI, 1.276–5.817; p = 0.010), and extracorporeal membrane oxygenation (OR, 2.931; 95% CI, 1.165–7.377; p = 0.022); patients with all three factors were younger (median 44 vs. 70 years, p < 0.001) and had significantly lower Acute Physiology and Chronic Health Evaluation II scores (median 12 vs. 16, p = 0.002) on the MV day. One-year cumulative mortality rates for patients with 0 to 3 factors were 66.7%, 50.8%, 38.9%, and 15.4%, respectively, with a significant difference among them (log-rank, p < 0.001). Conclusions: Three clinical factors associated with implementing a rehabilitation program during the quarantine period for COVID-19-associated ARDS patients were identified. The program was feasible and beneficial, particularly for younger patients with lower illness severity and fewer comorbidities on the day of MV.
Accuracy of Cup Placement Angle, Leg Lengthening, and Offset Measurement Using an AR-Based Portable Navigation System: Validation in Supine and Lateral Decubitus Positions for Total Hip Arthroplasty
Authors: Ozaki Yusuke , Yamamoto Takeaki , Kimura Satomi , Kasai Toru , Niki Rintaro , Niki Hisateru
Published: October 2024

Background and Objectives: Total hip arthroplasty (THA) requires accurate implant placement to ensure optimal outcomes. In this study, the AR Hip navigation system, an imageless portable navigation tool using augmented reality (AR), was evaluated for measuring radiographic inclination (RI), anteversion (RA), leg lengthening (LL), and offset (OS) changes in supine and lateral decubitus THA. Notably, this is the first report to assess the accuracy of LL and OS measurements using AR technology. Methods: We analyzed 48 hips from primary THA patients: 17 in the supine (S) group and 31 in the lateral (L) group. RI, RA, LL, and OS were measured intraoperatively using AR Hip and postoperatively using Zed Hip 3D software (Version 18.0.0.0). The absolute errors and outlier rates (≥5° for RI/RA and ≥5 mm for LL/OS) were compared between groups. Results: The mean intraoperative RI values with AR Hip were 40.1 ± 0.6° (S), 40.2 ± 1.2° (L), and 40.1 ± 1.0° (total), while the postoperative RI values with Zed Hip were 39.7 ± 2.9° (S), 39.5 ± 2.5° (L), and 39.6 ± 2.6° (total). The absolute errors were 1.8 ± 1.7° (total), with no significant group differences (p = 0.957). For RA, the errors were 2.0 ± 1.2° (total) (p = 0.771). The LL errors were 2.3 ± 2.2 mm (total) (p = 0.271), and the OS errors were 3.5 ± 2.8 mm (total) (p = 0.620). The outlier rates for RI were 11.8% (S) and 3.2% (L); for RA, 0% (S) and 3.2% (L); for LL, 29.4% (S) and 6.5% (L) with a significant difference (p = 0.031); and for OS, 23.5% (S) and 25.8% (L). No significant differences were observed for RI, RA, or OS. Conclusions: AR Hip provided accurate measurements of cup orientation, LL, and OS in both supine and lateral THA. Importantly, this study is the first to report the accuracy of LL and OS measurements using AR technology, demonstrating the potential of AR Hip for improving THA precision.
Microstructural and Mechanical Characterization of the Laser Beam Welded SAF 2507 Super-Duplex Stainless Steel
Authors: Šimeková Beáta , Dománková Mária , Kovaříková Ingrid , Kovačócy Pavel , Martinkovič Maroš , Šimek Michal , Ciuła Luke
Published: October 2024

The influence of laser beam welding parameters (power, welding rate, focusing, head oscillation, shielding gas) on the microstructure, mechanical properties and corrosion resistance of the super-duplex stainless steel SAF 2507 was studied in this paper. The presented results clearly report the effects of welding parameter changes on the character of the steel’s microstructure. The presence of secondary phase M2N in weld metals has an important influence on their mechanical properties. Optimal mechanical properties, an acceptable ferrite/austenite ratio, and the minimum content of M2N nitride required in the weld metal were acquired in the case the following application: 1100 W power, welding speed of 10 mm/s, focusing of 4 mm, and pure nitrogen shielding gas (20 L/min).
Integration of Metrology in Grinding and Polishing Processes for Rotationally Symmetrical Aspherical Surfaces with Optimized Material Removal Functions
Authors: Singh Ravi Pratap , Chen Yaolong
Published: October 2024

Aspherical surfaces, with their varying curvature, minimize aberrations and enhance clarity, making them essential in optics, aerospace, medical devices, and telecommunications. However, manufacturing these surfaces is challenging because of systematic errors in CNC equipment, tool wear, measurement inaccuracies, and environmental disturbances. These issues necessitate precise error compensation to achieve the desired surface shape. Traditional methods for spherical optics are inadequate for aspherical components, making accurate surface shape error detection and compensation crucial. This study integrates advanced metrology with optimized material removal functions in the grinding and polishing processes. By combining numerical control technology, computer technology, and data analysis, we developed CAM software (version 1) tailored for aspherical surfaces. This software uses a compensation correction algorithm to process error data and generate NC programs for machining. Our approach automates and digitizes the grinding and polishing process, improving efficiency and surface accuracy. This advancement enables high-precision mass production of rotationally symmetrical aspherical optical components, addressing existing manufacturing challenges and enhancing optical system performance.
Identification and Assessment of Secondary Metabolites from Three Fungal Endophytes of Solanum mauritianum Against Public Health Pathogens
Authors: Ogofure Abraham Goodness , Pelo Sharon Pauline , Green Ezekiel
Published: October 2024

Fungal endophytes, symbiotic microorganisms residing within plants, are renowned for producing bioactive secondary metabolites with diverse beneficial properties. We investigated the antimicrobial potential of fungal endophytes isolated from Solanum mauritianum, an invasive weed, against clinically significant bacterial pathogens. Selected fungal endophytes (Penicillium chrysogenum, Fusarium sp., and Paracamarosporium leucadendri) were isolated from the plant’s leaves and fruits. Their crude extracts were tested against various referenced strains, such as Mycobacterium species (M. smegmatis ATCC 607 and M. bovis ATCC 27290), Staphylococcus aureus ATCC 6571, Bacillus subtilis ATCC 11774, Klebsiella species (K. pneumoniae ATCC 10031 and K. oxytoca ATCC 8724), Escherichia coli ATCC 10536, and Pseudomonas aeruginosa ATCC 10145, using the Kirby-Bauer disk diffusion method. Resazurin Microtiter Assay was used for the determination of the minimum inhibitory concentration. The chemical nature of the secondary metabolites in the crude extracts produced by fungal endophytes was evaluated using high-resolution liquid chromatography–mass spectrometry (LC-MS) using water and acetonitrile gradient. Liquid chromatography quadrupole time-of-flight mass spectrometry (LC-QTOF-MS/MS) was employed for untargeted metabolomics. LC-QTOF-MS/MS identified 63 bioactive compounds across the three endophytes. P. chrysogenum had the highest activity against S. aureus and M. smegmatis (1.15 mg/mL and 0.02 mg/mL, respectively), while P. leucadendri demonstrated moderate activity against M. smegmatis (2.91 mg/mL) and E. coli (1.16 mg/mL). Fusarium sp. exhibited the broadest spectrum of antibacterial activity, with MIC values ranging from 0.03 mg/mL (B. subtilis) to 10 mg/mL (M. smegmatis). P. leucadendri produced 29 metabolites, Fusarium sp. had 23 identified metabolites, and a total of 11 metabolites were identified from P. chrysogenum. The fruits of the plant, accounting for 60%, appeared to be the most abundant in the endophyte diversity when compared to the stems and leaves. This study highlights the potential of fungal endophytes from S. mauritianum as a source of novel bioactive compounds, particularly against multidrug-resistant pathogens, contributing to the ongoing efforts to combat antimicrobial resistance.
Studies of the Sorption-Desorption of Pesticides from Cellulose-Based Derivative Nanocomposite Hydrogels
Authors: Tanaka Fabrício C. , Yonezawa Uilian G. , de Moura Marcia R. , Aouada Fauze A.
Published: October 2024

This study analyzed the effect of cellulose derivatives, namely methylcellulose (MC) and carboxymethylcellulose (CMC), on the stability of zeolite in a polymeric solution that would synthesize a three-dimensional network of poly(methacrylic acid)-co-polyacrylamide (PMAA-co-PAAm). Additionally, it investigated the effect of pH on the release of paraquat (PQ) and difenzoquat (DFZ) herbicides. Similar to previous studies with hydrogels containing CMC, the presence of bi and trivalent salts, such as Ca+2 and Al+3, also drastically reduced their swelling degree from 6.7 g/g in NaCl (0.15 mol·L−1) to 2.1 g/g in an AlCl3 solution (0.15 mol·L−1) for the MC nanocomposite. The viscosity results may suggest that the formation of a polysaccharide-zeolite complex contributed to the zeolite stabilization. As for the adsorption results, all samples adsorbed practically the entire concentration of both herbicides in an aqueous solution. Finally, it was also observed that the valence of the salts and molecular weight of the herbicide affect the release process, where DFZ was the herbicide with the highest concentration released. Both nanostructured hydrogels with CMC and MC exhibited lower release at pH = 7.0. These results demonstrated that a more in-depth evaluation of the phenomena involved in the application of these materials in controlled-release systems could help mitigate the impact caused by pesticides.
Upcycling Waste Polyethylene Terephthalate to Produce Nitrogen-Doped Porous Carbon for Enhanced Capacitive Deionization
Authors: Yu Hui , Duan Haiyan , Chen Liang , Zhu Weihua , Baranowska Daria , Hua Yumeng , Zhang Dengsong , Chen Xuecheng
Published: October 2024

Porous carbon with a high surface area and controllable pore size is needed for energy storage. It is still a significant challenge to produce porous carbon in an economical way. Nitrogen-doped porous carbon (N-PC) was prepared through carbonization of a mixture of waste PET-derived metal–organic frameworks (MOFs) and ammonium. The obtained N-PC exhibits a large surface area and controlled pore size. When utilized as an electrode material for supercapacitors, the N-PC exhibits a specific capacitance of 224 F g−1, significantly surpassing that of commercial activated carbon (AC), which has a capacitance of 111 F g−1. In the subsequent capacitive deionization (CDI) tests, the N-PC demonstrated a maximum salt adsorption capacity of 19.9 mg g−1 at 1.2 V in a NaCl electrolyte (0.5 g L−1), and the salt adsorption capacity increased to 24.7 mg g−1 at 1.4 V. The N-PC electrode also exhibited superior regeneration. The present work not only presents a potential approach to develop cost-effective electrodes for seawater purification but also paves the way for recycling of waste plastics into high value-added products.
Glycerol Carbonate as an Emulsifier for Light Crude Oil: Synthesis, Characterization, and Stability Analysis
Authors: Morales Cepeda Ana Beatriz , Villalobos Neri Elda Elizabeth , Macclesh del Pino Pérez Luis Alejandro , Gonzalez Pedraza Eric Joaquin
Published: October 2024

This study focuses on the synthesis and application of glycerol carbonate (GC) as an emulsifier for light crude oil. GC was synthesized from glycerol and dimethyl carbonate via transesterification, achieving a 90% yield. Characterization through 1H-NMR, 13C-NMR, and FT-IR confirmed its structure. The emulsification properties of GC were tested by mixing it with light crude oil and water, demonstrating effective emulsification and forming stable emulsions. Stability tests with GC concentrations of 60/40, 70/30, and 80/20 revealed that emulsions remained stable for over 24 h. A particle size analysis indicated that higher GC concentrations produced smaller droplet sizes, enhancing the emulsification efficiency. This study highlights the potential applications of GC in oil spill remediation and enhanced oil recovery, emphasizing its biodegradability and low toxicity as environmental benefits. Overall, GC is presented as an effective and eco-friendly emulsifier for light crude oil, offering stable emulsions and promising industrial applications.
Soloxolone N-3-(Dimethylamino)propylamide Restores Drug Sensitivity of Tumor Cells with Multidrug-Resistant Phenotype via Inhibition of P-Glycoprotein Efflux Function
Authors: Moralev Arseny D. , Salomatina Oksana V. , Salakhutdinov Nariman F. , Zenkova Marina A. , Markov Andrey V.
Published: October 2024

Multidrug resistance (MDR) remains a significant challenge in cancer therapy, primarily due to the overexpression of transmembrane drug transporters, with P-glycoprotein (P-gp) being a central focus. Consequently, the development of P-gp inhibitors has emerged as a promising strategy to combat MDR. Given the P-gp targeting potential of soloxolone amides previously predicted by us by an absorption, distribution, metabolism, excretion, and toxicity (ADMET) analysis, the aim of the current study was to experimentally verify their P-gp inhibitory and MDR reversing activities in vitro. Screening of soloxolone amides as modulators of P-gp using molecular docking and cellular P-gp substrate efflux assays revealed the ability of compound 4 bearing a N-3-(dimethylamino)propylamide group to interact with the active site of P-gp and inhibit its transport function. Blind and site-specific molecular docking accompanied by a kinetic assay showed that 4 directly binds to the P-gp transmembrane domain with a binding energy similar to that of zosuquidar, a third-generation P-gp inhibitor (ΔG = −10.3 kcal/mol). In vitro assays confirmed that compound 4 enhanced the uptake of Rhodamine 123 (Rho123) and doxorubicin (DOX) by the P-gp-overexpressing human cervical carcinoma KB-8-5 (by 10.2- and 1.5-fold, respectively (p < 0.05, unpaired t-test)) and murine lymphosarcoma RLS40 (by 15.6- and 1.75-fold, respectively (p < 0.05, unpaired t-test)) cells at non-toxic concentrations. In these cell models, 4 showed comparable or slightly higher activity than the reference inhibitor verapamil (VPM), with the most pronounced effect of the hit compound in Rho123-loaded RLS40 cells, where 4 was 2-fold more effective than VPM. Moreover, 4 synergistically restored the sensitivity of KB-8-5 cells to the cytotoxic effect of DOX, demonstrating MDR reversal activity. Based on the data obtained, 4 can be considered as a drug candidate to combat the P-gp-mediated MDR of tumor cells and semisynthetic triterpenoids, with amide moieties in general representing a promising scaffold for the development of novel therapeutics for tumors with low susceptibility to antineoplastic agents.
Electrical Transport Properties of PbS Quantum Dot/Graphene Heterostructures
Authors: Ying Haosong , Wei Binbin , Zang Qing , Dong Jiduo , Zhang Hao , Tian Hao , Liu Chunheng , Liu Yang
Published: October 2024

The integration of PbS quantum dots (QDs) with graphene represents a notable advancement in enhancing the optoelectronic properties of quantum-dot-based devices. This study investigated the electrical transport properties of PbS quantum dot (QD)/graphene heterostructures, leveraging the high carrier mobility of graphene. We fabricated QD/graphene/SiO2/Si heterostructures by synthesizing p-type monolayer graphene via chemical vapor deposition and spin-coating PbS QDs on the surface. Then, we used a low-temperature electrical transport measurement system to study the electrical transport properties of the heterostructure under different temperature, gate voltage, and light conditions and compared them with bare graphene samples. The results indicated that the QD/graphene samples exhibited higher resistance than graphene alone, with both resistances slightly increasing with temperature. The QD/graphene samples exhibited significant hole doping, with conductivity increasing from 0.0002 Ω−1 to 0.0007 Ω−1 under gate voltage modulation. As the temperature increased from 5 K to 300 K, hole mobility decreased from 1200 cm2V−1s−1 to 400 cm2V−1s−1 and electron mobility decreased from 800 cm2V−1s−1 to 200 cm2V−1s−1. Infrared illumination reduced resistance, thereby enhancing conductivity, with a resistance change of about 0.4%/mW at a gate voltage of 125 V, demonstrating the potential of these heterostructures for infrared photodetector applications. These findings offer significant insights into the charge transport mechanisms in low-dimensional materials, paving the way for high-performance optoelectronic devices.
Colossal Dielectric Constant of Nanocrystalline/Amorphous Homo-Composite BaTiO3 Films Deposited via Pulsed Laser Deposition Technique
Authors: Kondo Shinya , Murakami Taichi , Pichon Loick , Leblanc-Lavoie Joël , Teranishi Takashi , Kishimoto Akira , El Khakani My Ali
Published: October 2024

We report the pulsed laser deposition (PLD) of nanocrystalline/amorphous homo-composite BaTiO3 (BTO) films exhibiting an unprecedented combination of a colossal dielectric constant (εr) and extremely low dielectric loss (tan δ). By varying the substrate deposition temperature (Td) over a wide range (300–800 °C), we identified Td = 550 °C as the optimal temperature for growing BTO films with an εr as high as ~3060 and a tan δ as low as 0.04 (at 20 kHz). High-resolution transmission electron microscopy revealed that the PLD-BTO films consist of BTO nanocrystals (~20–30 nm size) embedded within an otherwise amorphous BTO matrix. The impressive dielectric behavior is attributed to the combination of highly crystallized small BTO nanograins, which amplify interfacial polarization, and the surrounding amorphous matrix, which effectively isolates the nanograins from charge carrier transport. Our findings could facilitate the development of next-generation integrated dielectric devices.
Printability Metrics and Engineering Response of HDPE/Si3N4 Nanocomposites in MEX Additive Manufacturing
Authors: Papadakis Vassilis M. , Petousis Markos , Michailidis Nikolaos , Spyridaki Maria , Valsamos Ioannis , Argyros Apostolos , Gkagkanatsiou Katerina , Moutsopoulou Amalia , Vidakis Nectarios
Published: October 2024

Herein, silicon nitride (Si3N4) was the selected additive to be examined for its reinforcing properties on high-density polyethylene (HDPE) by exploiting techniques of the popular material extrusion (MEX) 3D printing method. Six different HDPE/Si3N4 composites with filler percentages ranging between 0.0–10.0 wt. %, having a 2.0 step, were produced initially in compounds, then in filaments, and later in the form of specimens, to be examined by a series of tests. Thermal, rheological, mechanical, structural, and morphological analyses were also performed. For comprehensive mechanical characterization, tensile, flexural, microhardness (M-H), and Charpy impacts were included. Scanning electron microscopy (SME) was used for morphological assessments and microcomputed tomography (μ-CT). Raman spectroscopy was conducted, and the elemental composition was assessed using energy-dispersive spectroscopy (EDS). The HDPE/Si3N4 composite with 6.0 wt. % was the one with an enhancing performance higher than the rest of the composites, in the majority of the mechanical metrics (more than 20% in the tensile and flexural experiment), showing a strong potential for Si3N4 as a reinforcement additive in 3D printing. This method can be easily industrialized by further exploiting the MEX 3D printing method.
Silver-Doped Reduced Graphene Oxide/PANI-DBSA-PLA Composite 3D-Printed Supercapacitors
Authors: Cirillo Claudia , Iuliano Mariagrazia , Scarpa Davide , Iovane Pierpaolo , Borriello Carmela , Portofino Sabrina , Galvagno Sergio , Sarno Maria
Published: October 2024

This study presents a novel approach to the development of high-performance supercapacitors through 3D printing technology. We synthesized a composite material consisting of silver-doped reduced graphene oxide (rGO) and dodecylbenzenesulfonic acid (DBSA)-doped polyaniline (PANI), which was further blended with polylactic acid (PLA) for additive manufacturing. The composite was extruded into filaments and printed into circular disc electrodes using fused deposition modeling (FDM). These electrodes were assembled into symmetric supercapacitor devices with a solid-state electrolyte. Electrochemical characterization, including cyclic voltammetry (CV) and galvanostatic charge–discharge (GCD) tests, demonstrated considerable mass-specific capacitance values of 136.2 F/g and 133 F/g at 20 mV/s and 1 A/g, respectively. The devices showed excellent stability, retaining 91% of their initial capacitance after 5000 cycles. The incorporation of silver nanoparticles enhanced the conductivity of rGO, while PANI-DBSA improved electrochemical stability and performance. This study highlights the potential of combining advanced materials with 3D printing to optimize energy storage devices, offering a significant advancement over traditional manufacturing methods.
Enhancing Charge Trapping Performance of Hafnia Thin Films Using Sequential Plasma Atomic Layer Deposition
Authors: Kim So-Won , Yoo Jae-Hoon , Park Won-Ji , Lee Chan-Hee , Lee Joung-Ho , Kim Jong-Hwan , Uhm Sae-Hoon , Lee Hee-Chul
Published: October 2024

We aimed to fabricate reliable memory devices using HfO2, which is gaining attention as a charge-trapping layer material for next-generation NAND flash memory. To this end, a new atomic layer deposition process using sequential remote plasma (RP) and direct plasma (DP) was designed to create charge-trapping memory devices. Subsequently, the operational characteristics of the devices were analyzed based on the thickness ratio of thin films deposited using the sequential RP and DP processes. As the thickness of the initially RP-deposited thin film increased, the memory window and retention also increased, while the interface defect density and leakage current decreased. When the thickness of the RP-deposited thin film was 7 nm, a maximum memory window of 10.1 V was achieved at an operating voltage of ±10 V, and the interface trap density (Dit) reached a minimum value of 1.0 × 1012 eV−1cm−2. Once the RP-deposited thin film reaches a certain thickness, the ion bombardment effect from DP on the substrate is expected to decrease, improving the Si/SiO2/HfO2 interface and thereby enhancing device endurance and reliability. This study confirmed that the proposed sequential RP and DP deposition processes could resolve issues related to unstable interface layers, improve device performance, and enhance process throughput.
Comparison of the Gut Microbiota of Patients Who Improve with Antibiotic Combination Therapy for Ulcerative Colitis and Those Who Do Not: Investigation by Fecal Metagenomic Analyses
Authors: Ohkusa Toshifumi , Kato Kimitoshi , Sekizuka Tsuyoshi , Sugiyama Toshiro , Sato Nobuhiro , Kuroda Makoto
Published: October 2024

Background/Objectives: The cause of ulcerative colitis (UC) may be related to commensal bacteria in genetically susceptible patients. We previously demonstrated that triple antibiotic combination therapy induces remission in patients with active UC in randomized controlled trials (RCTs). Now, we investigate changes in the gut microbiota of patients who responded to the antibiotic combination therapy. Methods: Thirty-one patients with UC given ATM/AFM (amoxicillin, metronidazole, and tetracycline or fosfomycin) therapy for two weeks were enrolled in this study. The clinical conditions of these UC patients were evaluated by the partial Mayo score. The gut microbiota was compared via the metagenomic shot gun analysis of fecal samples. Results: Of the 31 patients, 16 and 8 experienced complete and partial remission, respectively, over three months in response to ATM/AFM therapy, whereas ATM/AFM showed no efficacy in 7 patients. The dysbiosis before treatment in the active stage could be associated with increased populations of Bacteroides, Parabacteroides, Rickenella, Clostridium, Flavonifractor, Pelagibacter, Bordetella, Massilia, and Piscrickettsia species. Metagenomic analysis revealed dramatic changes in the gut microbiota at an early stage, that is, just two weeks after starting ATM/AFM therapy. After treatment in the responder group, the populations of bifidobacterium and lactobacilli species were significantly increased, while the population of bacteroides decreased. Conclusions: These results suggest that metagenomic analysis demonstrated a marked change in the gut microbiota after antibiotic combination treatment. In the triple antibiotic combination therapy, remission was associated with an increase in bifidobacterium and lactobacilli species.
Vitamin D Supply of Twins during Fetal Life, Its Relation to Anthropometric Parameters of Newborns and the Analysis of Other Factors Related to Birth Size
Authors: Wierzejska Regina Ewa , Wojda Barbara , Bomba-Opoń Dorota Agata , Rzucidło-Szymańska Iga , Brawura-Biskupski-Samaha Robert , Szymusik Iwona
Published: October 2024

Background/Objectives: Vitamin D deficiencies are very common in pregnant women, raising concerns about adverse health outcomes in children. This issue has hardly been studied in multiple pregnancies, the prevalence of which has been steadily increasing. Therefore, our study investigated the relationship between newborns’ anthropometric parameters and the concentration of 25(OH)D in maternal blood of women with twin pregnancies and umbilical cord blood. Methods: The study included 50 women who gave birth after the 36th week of twin gestation. The concentration of 25(OH)D was determined in maternal blood collected during the antenatal period and in the umbilical cord blood of 100 newborns. Anthropometric parameters of the newborns (birth weight, length and head and chest circumference) were obtained from hospital records. Data on nutrition and lifestyle during pregnancy were collected from the patients during an interview conducted by a dietitian. Results: No relationship between maternal and neonatal cord blood vitamin D concentrations and any of the anthropometric parameters of the newborns was found. However, only 6% of the mothers and 13% of the newborns had vitamin D deficiency (≤20 ng/mL). The type of pregnancy and maternal height were the main factors associated with neonatal size. Newborns from dichorionic pregnancies were on average 202 g heavier (p < 0.001) and 1 cm longer (p = 0.006) than newborns from monochorionic pregnancies. Newborns of mothers ≤160 cm in height had on average 206 g lower birth weight (p = 0.006) and were 3.5 cm shorter (p = 0.003) compared to newborns of taller mothers. Conclusions: Therefore, in our study, the neonatal size of twins was not related to the vitamin D status but to other factors such as the type of pregnancy and maternal height.
Evaluation of Complementary Feeding Indicators Among Children Aged 6–23 Months According to the Health Literacy Status of Their Mothers
Authors: Kocagozoglu Sevim Gonca , Sengelen Meltem , Yalcin Siddika Songul
Published: October 2024

Background/Objectives: Infant and young child feeding (IYCF) practices directly affect child health, development, and survival, especially under 2 years of age and ultimately affect adult life well-being. As the primary caregivers of the children, mothers with higher health literacy may better perceive the benefits of optimal complementary feeding practices, leading to improved health outcomes for their children. In this study, we aimed to assess complementary feeding practices among children aged 6–23 months in Turkey according to 2021 World Health Organization IYCF indicators [minimum dietary diversity (MDD); minimum meal frequency (MMF); minimum acceptable diet (MAD); egg and/or flesh food consumption (EFF); sweet beverage consumption (SwB); unhealthy food consumption (UFC); zero vegetable or fruit consumption (ZVF); and bottle feeding (BoF)] and investigate their associations with sociodemographic characteristics and mothers’ health literacy. Methods: With a descriptive study design, we reached 572 mothers of children aged 6–23 months from five regions of Turkey. We used the Turkey Health Literacy Scale-32 (TSOY-32) to assess mothers’ health literacy. Results: While maternal and child age are significantly associated with more complementary feeding practices, specifically MDD, MAD, and EFF, having multiple children has negative impacts on several complementary feeding indicators, including MDD, MMF, MAD, UFC, and ZVF. The only indicator associated with mothers’ TSOY-32 scores was zero fruit and vegetable consumption. Conclusion: Raising awareness among mothers about the importance of complementary feeding practices and identification of vulnerable groups will guide practitioners and policymakers to improve child health and nutrition.
Effect of Moderate Beer Intake on the Lipid Composition of Human Red Blood Cell Membranes
Authors: López-Yerena Anallely , Muñoz-García Natalia , de Santisteban Villaplana Victoria , Padro Teresa , Badimon Lina
Published: October 2024

Background/Objectives: Growing evidence suggests that erythrocyte membrane lipids are subject to changes during their lifespan. Factors such as the type of dietary intake and its composition contribute to the changes in red blood cell (RBC) membranes. Due to the high antioxidant content of beer, we aimed to investigate the effect of moderate beer consumption on the lipid composition of RBCs membranes from healthy overweight individuals. Methods: We conducted a four-weeks, prospective two-arm longitudinal crossed-over study, where participants (n = 36) were randomly assigned to alcohol-free beer group or traditional beer group. The lipids of RBCs membranes were assessed at the beginning and the end of the intervention by thin-layer chromatography. Results: Four-weeks of alcohol-free beer promoted changes in fatty acids (FA), free cholesterol (FC), phosphatidylethanolamine (PE) and phosphatidylcholine (PC) (p < 0.05). Meanwhile, traditional beer intake led to changes in FA, FC, phospholipids (PL), PE and PC (p < 0.05). The observed alterations in membrane lipids were found to be independent of sex and BMI as influencing factors. Conclusions: The lipid composition of erythrocyte membranes is distinctly but mildly influenced by the consumption of both non-alcoholic and conventional beer, with no effects on RBC membrane fluidity.
Association Between Gut Microbiome Composition and Physical Characteristics in Patients with Severe Motor and Intellectual Disabilities: Perspectives from Microbial Diversity
Authors: Kageyama Suzumi , Inoue Rikako , Hosomi Koji , Park Jonguk , Yumioka Hitomi , Doi Miki , Miyake Miyuu , Nagashio Yuka , Shibuya Yoshiko , Oka Nobue , Akazawa Hirofumi , Kanzaki Susumu , Mizuguchi Kenji , Kunisawa Jun , Irie Yasuyuki
Published: October 2024

Background: The human gut environment undergoes substantial changes as a host ages. This investigation centered on the gut microbiome diversity among patients with severe motor and intellectual disabilities (SMID), examining the association between the gut microbiome composition and physical characteristics with varying levels of diversity. Methods: Fourteen subjects were investigated, with physical and defecation status, blood biochemical test, gut microbiome profiling, and fecal metabolites used to divide the patients into a high-diversity group (HD, eight patients) and a low-diversity group (LD, six patients). Results: Findings indicated that the microbiome of the LD group showed delayed maturation reminiscent of neonates and lactating infants. Analysis of the fecal bile acids (BAs) revealed a markedly diminished proportion of deoxycholic acid in the secondary BAs in the LD group, suggestive of inadequate conversion from primary to secondary BAs. Furthermore, the LD group presented with loose stools. The LD group exhibited a higher degree of physical severity, with all patients bedridden and fed via gastrostomy with only enteral formula received. Conclusions: The composition of the gut microbiome and BAs in the LD group was found to differ from those of healthy individuals and the HD group, indicating a potentially immature gut environment for these individuals.
Anti-Obesity Effects of a Collagen with Low Digestibility and High Swelling Capacity: A Human Randomized Control Trial
Authors: López-Yoldi Miguel , Riezu-Boj José I. , Abete Itziar , Ibero-Baraibar Idoia , Aranaz Paula , González-Salazar Itxaso , Izco Jesús M. , Recalde José I. , González-Navarro Carlos J. , Milagro Fermín I. , Zulet María A.
Published: October 2024

Background/Objectives: Collagen is a protein formed by very long amino acid chains. When conveniently treated, it can incorporate water into the net, thus increasing its volume and mass. The present work aimed to evaluate the potential anti-obesity effects of bovine collagen that has been technologically treated to increase its water retention capacity in an acid pH medium, with the objective of inducing satiation. Methods: Collagen’s digestibility was tested with a pepsin digestion test. Its swelling capacity was tested in an acid pH medium simulating gastric conditions. Postprandial levels of ghrelin in response to collagen supplementation were tested in rats. In a randomized control trial, 64 subjects with overweight/obesity were allocated in two groups: supplemented daily with two protein bars enriched with collagen (20 g per day) for 12 weeks, or control group. Anthropometric and biochemical measurements were assessed in all the participants. Results: This collagen showed a low digestibility (<60%) and high swelling capacity (>1900%) in vitro. In humans with overweight and obesity, this collagen significantly reduced body weight, body mass index (BMI), systolic blood pressure (SBP), and fatty liver index (FLI) and increased fat-free mass when compared with the control group. A significant reduction in the sarcopenic index; total, troncular, and visceral fat (measured by DEXA); and serum leptin levels were observed in the collagen group at the end of the intervention, with no differences with respect to controls. Collagen reduced the sensation of hunger and increased fullness and satisfaction. In male Wistar rats, collagen decreased postprandial blood ghrelin levels. Conclusions: Collagen supplementation (20 g per day for 12 weeks) reduced body weight, BMI, waist circumference, fat mass, FLI, and SBP in humans with overweight and obesity, which might be related to the increased sensation of fullness and satisfaction reported by the volunteers after the intake.