bluuebunny/crossref_metadata_2025 huggingface dataset:
The Effect of Tacrine on Functional Response of the Lower Oesophageal Sphincter Assessed by Endoscopic Luminal Impedance Planimetry in Experimental Pigs
Authors: Bures Jan , Novak Martin , Radochova Vera , Kohoutova Darina , Prchal Lukas , Martinek Jan , Mares Jan , Cerny Jaroslav , Suchanek Stepan , Pejchal Jaroslav , Voxova Barbora , Urbanek Petr , Zavoral Miroslav , Soukup Ondrej
Published: November 2024

Background/Objectives: Tacrine is a centrally active non-competitive reversible acetylcholinesterase inhibitor. It also exerts antagonising activity against N-methyl-D-aspartate receptors. Tacrine was approved for the treatment of Alzheimer’s disease in 1993, but was withdrawn from clinical use in 2013 because of its hepatotoxicity and gastrointestinal side effects. Nevertheless, tacrine is currently facing a renewed wave of interest primarily due to several new tacrine-incorporated hybrids and derivates. There were two specific aims for this study: firstly, to explain the mechanisms of the adverse action of tacrine, as a distinctive example of a highly effective acetylcholinesterase inhibitor; and secondly to check whether luminal impedance planimetry is feasible for preclinical testing of possible side effects of compounds potentially toxic to the gastrointestinal tract. Methods: Six experimental pigs were used as the animal model in this study. Five major parameters were evaluated: luminal pressure (mmHg), estimated diameter (mm), cross-sectional area (mm2), distensibility (mm2/mmHg), and zone compliance (mm3/mmHg). All measurements were performed before and 360 min after intragastric administration of 200 mg tacrine (at the porcine tacrine Tmax). Results: This study consistently demonstrated an increase in luminal pressure (a directly measured indicator) for the particular balloon filling volumes used, and inversely a reciprocal decrease in the other parameters after tacrine administration. Conclusions: Endoscopic luminal impedance planimetry is a feasible method to evaluate functional response of the lower oesophageal sphincter to tacrine in experimental pigs. Tacrine did not compromise the function of the lower oesophageal sphincter either toward oesophageal spasms or, in contrast, decreased competence of the lower oesophageal sphincter.
Using Poly(amidoamine) PAMAM-βCD Dendrimer for Controlled and Prolonged Delivery of Doxorubicin as Alternative System for Cancer Treatment
Authors: Sorroza-Martínez Kendra , González-Sánchez Ignacio , Villamil-Ramos Raúl , Cerbón Marco , Guerrero-Álvarez Jorge Antonio , Coronel-Cruz Cristina , Rivera Ernesto , González-Méndez Israel
Published: November 2024

Background/Objectives: Doxorubicin (Dox) is an anticancer drug used in the treatment of a wide range of solid tumors; however, Dox causes systemic toxicity and irreversible cardiotoxicity. The design of a new nanosystem that allows for the control of Dox loading and delivery results is a powerful tool to control Dox release only in cancer cells. For this reason, supramolecular self-assembly was performed between a poly(amidoamine) (PAMAM) dendrimer decorated with four β-cyclodextrin (βCD) units (PAMAM-βCD) and an adamantane–hydrazone–doxorubicin (Ad-h-Dox) prodrug. Methods: The formation of inclusion complexes (ICs) between the prodrug and all the βCD cavities present on the surface of the PAMAM-βCD dendrimer was followed by 1H-NMR titration and corroborated by 2D NOESY experiments. A full characterization of the supramolecular assembly was performed in the solid state by thermal analysis (DSC/TGA) and scanning electron microscopy (SEM) and in solution by the DOSY NMR technique in D2O. Furthermore, the Dox release profiles from the PAMAM-βCD/Ad-h-Dox assembly at different pH values was studied by comparing the efficiency against a native βCD/Ad-h-Dox IC. Additionally, in vitro cytotoxic activity assays were performed for the nanocarrier alone and the two supramolecular assemblies in different carcinogenic cell lines. Results: The PAMAM-βCD/Ad-h-Dox assembly was adequately characterized, and the cytotoxic activity results demonstrate that the nanocarrier alone and its hydrolysis product are innocuous compared to the PAMAM-βCD/Ad-h-Dox nanocarrier that showed cytotoxicity equivalent to free Dox in the tested cancer cell lines. The in vitro drug release assays for the PAMAM-βCD/Ad-h-Dox system showed an acidic pH-dependent behavior and a prolonged profile of up to more than 72 h. Conclusions: The design of PAMAM-βCD/Ad-h-Dox consists of a new controlled and prolonged Dox release system for potential use in cancer treatment.
LC-MS/MS-Based Concurrent Quantification of Cannabidiol and Melatonin in Mouse Plasma to Elucidate Complex PK Interactions
Authors: Wang Mengran , Zhang Wenpeng , Wu Xia , Wang Lingchao , Li Cong , Liu Chunyan , Zhuang Xiaomei
Published: November 2024

Objective: This study aimed to develop a quantitative analytical method for the simultaneous determination of cannabidiol (CBD) and melatonin (MT) in mouse plasma using the protein precipitation method coupled with LC-MS/MS. Additionally, this study sought to investigate the impact of CBD on the pharmacokinetics of MT in mice using this method. Methods: Mouse plasma samples were precipitated with acetonitrile and analyzed using a Kromasil 100-5-C8 (2.1 × 50 mm) column. Following a single administration, thirty male ICR mice were randomly assigned to five groups: MT 2 mg/kg intravenously (i.v.), MT 10 mg/kg orally (p.o.), MT + CBD (10 + 10) mg/kg p.o., MT + CBD (10 + 40) mg/kg p.o., and MT 10 mg/kg p.o. followed by CBD 2 mg/kg i.v. Pharmacokinetic parameters were calculated using a non-compartmental model and analyzed to investigate the interactions of CBD with MT. Results: The calibration curves for CBD and MT were linear over the range of 2 to 1000 ng/mL. Co-administration of a high dose of CBD (40 mg/kg) orally reduced the Cmax of MT (10 mg/kg) to 57% of the control, while the area under the curve from 0.5 to 8 h (AUC(0.5–8h)) was 2.85-fold that of the MT-only group. When CBD (2 mg/kg) was administered intravenously alongside MT orally, the AUC(0.5–8h) was 1.54 times that of MT given orally alone. The AUC of CBD was positively correlated with the AUC of the distribution and elimination phases of MT, while the Cmax of CBD negatively correlated with the Cmax of MT. Conclusions: The developed LC-MS/MS method is robust and suitable for pharmacokinetic studies involving CBD and MT. The in vivo effects of CBD on MT pharmacokinetics are complex. High oral doses of CBD inhibit both the intestinal absorption and metabolic clearance of MT, resulting in a more smooth PK profile.
Study on the Scale-Up Possibility of a Combined Wet Grinding Technique Intended for Oral Administration of Meloxicam Nanosuspension
Authors: Bartos Csilla , Motzwickler-Németh Anett , Kovács Dávid , Burián Katalin , Ambrus Rita
Published: November 2024

Background/Objectives: This article reports on the scalability of a combined wet grinding technique applying planetary ball mill and ZrO2 pearls as the grinding medium. After the determination of the parameters in a laboratory scale, the tenfold scale-up method was set. Meloxicam (MEL) was used as a nonsteroidal anti-inflammatory drug (NSAID) intended for per os delivery. During grinding, the PVA solution was used as a dispersion medium. Methods: The influence of the scaling-up on the particle size, morphology, crystallinity, and intra- and interparticulate phenomena has been studied. Formulation investigations of the milled suspensions were carried out. The dissolution test and the cytotoxicity analyses were accomplished. Results: Submicron MEL particle-containing samples were produced in both grinding scales. After the particle size determination was achieved from the suspensions, the wet milled, dried products were studied. The particle size of the dried products fell into the same range for both scales of milling (the maximum particle size was about 580 nm). There was no significant difference in drug crystallinity after the grindings; 70% of MEL remained crystalline in both cases. A remarkable interaction between the components did not develop as a result of milling. The polarity of the products increased, which resulted in a better dissolution, especially in the case of intestinal fluid (~100% in the first 5 min). The products were not found to be toxic. Conclusions: This research demonstrates that the scaling-up of combined wet grinding technique is feasible by adjusting the milling parameters and the adequate amount of excipient.
Net Promoter Score Model for Evaluating Paediatric Medicine Acceptability: Validation and Feasibility Study
Authors: Yoo Okhee , Stanford Demi , von Ungern-Sternberg Britta S. , Lim Lee Yong
Published: November 2024

Background/Objectives: Medicine acceptability is crucial for paediatric drug development, yet its assessment remains challenging due to the multifaceted nature of sensory attributes like taste, smell, and mouthfeel. Traditional methods of acceptability evaluation often involve complex questionnaires and lack standardisation, leading to difficulties in a comparative analysis across studies. This study aimed to develop a simplified, standardised approach for assessing medicine acceptability introducing the Net Promoter Score (NPS) framework to derive a Medicine Acceptability Score (MAS). Methods: A retrospective analysis was conducted using taste assessment data from nine paediatric formulations across four studies. The MAS was calculated by identifying an optimal range for categorising participant responses, which encapsulated diverse sensory attributes into a single metric. Validation was performed across various age groups and different formulations to test the reliability and discriminatory power of MAS. Results: The MAS effectively discriminated between acceptable and unacceptable formulations, providing a practical tool for formulation development. Conclusions: The MAS offers a novel, standardised metric for evaluating paediatric medicine acceptability, addressing key limitations of traditional methods. Future studies are recommended to refine the MAS model through the establishment of benchmark scores for chronic and acute medications, thereby standardising acceptability assessment of medicines across the pharmaceutical industry.
A Bait-and-Hook Hydrogel for Net Tumor Cells to Enhance Chemotherapy and Mitigate Metastatic Dissemination
Authors: Chen Cailian , Liu Jinying , Zhang Hongbo , Zhang Hongrui , Liang Yanhui , Ye Qilian , Shen Wei , Luo Haibin , Guo Ling
Published: November 2024

Background: Lung cancer is an aggressive disease with rapid progression and a high rate of metastasis, leading to a significantly poor prognosis for many patients. While chemotherapy continues to serve as a cornerstone treatment for a large proportion of lung cancer patients, expanding preclinical and clinical evidence indicates that chemotherapy may promote tumor metastasis and cause side effects. Methods: We develop an injectable bait-and-hook hydrogel (BH-gel) for targeted tumor cell eradication, which embedded doxorubicin liposomes as cytotoxic agents and CXCL12 as a chemoattractant to capture and kill tumor cells. The hydrogel backbone was formed through covalent cross-linking between PVA and borax. In vitro, we investigated tumor recruitment and the antitumor effects in A549 cells. In vivo, we explored the anti-metastatic and antitumor activities against lung cancer. Results: BH-gel retained CXCL12 within its three-dimensional porous architecture for gradual release, effectively recruiting tumor cells. In contrast, blank hydrogel failed to achieve this. After encapsulation in BH-gel, the therapeutic efficacy of doxorubicin liposomes for tumor eradication was markedly improved, significantly reducing metastatic tumor presence to near-undetectable levels, while also resulting in notable reductions in cardiotoxicity and hepatotoxicity. Notably, BH-gel adhered well to tissues and exhibited exceptional electrical conductivity, which may be further developed into a real-time tumor monitoring system, facilitating timely therapeutic adjustments. Conclusions: BH-gel utilizes CXCL12 as a bait to recruit and entrap tumor cells in a three-dimensional porous matrix and subsequently kill them with embedded doxorubicin liposomes, thereby tackling the issue of metastatic spread. This bait-and-hook strategy has significant implications for the field of anti-metastasis medicine and shows considerable potential for clinical application.
The Intra-Articular Delivery of a Low-Dose Adeno-Associated Virus-IL-1 Receptor Antagonist Vector Alleviates the Progress of Arthritis in an Osteoarthritis Rat Model
Authors: Luo Shuang , Jiang Hao , Li Qingwei , Yang Shiping , Yu Xuemei , Xu Xiongliang , Xie Qing , Ke Xiao , Zheng Qiang
Published: November 2024

Background/Objectives: Interleukin-1 (IL-1) is a pivotal mediator in the pathological progression of osteoarthritis (OA), playing a central role in disease progression. However, the rapid clearance of IL-1 receptor antagonist (IL-1Ra) from the joints may hinder the efficacy of intra-articular IL-1Ra injections in reducing OA-associated pain or cartilage degradation. Methods: Sustaining sufficient levels of IL-1Ra within the joints via adeno-associated virus (AAV)-mediated gene therapy presents a promising therapeutic strategy for OA. In this study, we constructed an IL-1Ra expression cassette employing intron insertion in the coding sequence (CDS) region to enhance protein expression levels. Furthermore, we incorporated precisely targeted liver-specific microRNA (miRNA) sequences to specifically downregulate transgene expression within hepatic tissues, thereby ensuring more targeted and controlled regulation of gene expression. Results: A rat model of OA was employed to compare the efficacy of AAV5 and AAV9 for IL-1Ra delivery at both high and low doses. It was observed that low-dose, but not high-dose, AAV9-IL-1Ra resulted in a significant reduction in joint swelling, accompanied by a decrease in the diameter of the affected area and the preservation of biomarkers associated with trabecular bone integrity. Conclusions: These results highlight the great potential of AAV9-IL-1Ra in osteoarthritis therapy, with the promise of achieving long-term improvement through a single intra-articular injection.
Bidirectional Propagation Properties of Partially Coherent Laguerre–Gaussian Beams in Atmospheric Turbulence and Plasma
Authors: Zhang Yuelei , Yao Linxuan , Zhao Yuanhao , Zhang Hui , Cai Yangjian , Yuan Yangsheng , Gao Yaru
Published: November 2024

The bidirectional propagation properties of partially coherent Laguerre–Gaussian (PCLG) beams under atmospheric turbulence and plasma were numerically investigated. The corresponding analytical formulas for the intensity distribution, effective beam width, and M2 factor of PCLG beams were derived by utilizing the generalized Collins integral formula, atmospheric turbulence theory, and second-order moments theory of the Wigner distribution function. The intensity distribution of the PCLG beams ultimately evolved into a Gaussian-like intensity distribution. Additionally, the effective beam width and M2 factor could be less affected by selecting appropriate parameter values for the beam order, transverse coherence width, and wavelength of the PCLG beam. The impact of parameters such as the beam order, transverse coherence width, and wavelength for reverse transmission on the PCLG beam propagation properties was greater than that for forward transmission. These results are beneficial for applications in free-space optical communications.
Machine Learning Inference of Gene Regulatory Networks in Developing Mimulus Seeds
Authors: Tucci Albert , Flores-Vergara Miguel A. , Franks Robert G.
Published: November 2024

The angiosperm seed represents a critical evolutionary breakthrough that has been shown to propel the reproductive success and radiation of flowering plants. Seeds promote the rapid diversification of angiosperms by establishing postzygotic reproductive barriers, such as hybrid seed inviability. While prezygotic barriers to reproduction tend to be transient, postzygotic barriers are often permanent and therefore can play a pivotal role in facilitating speciation. This property of the angiosperm seed is exemplified in the Mimulus genus. In order to further the understanding of the gene regulatory mechanisms important in the Mimulus seed, we performed gene regulatory network (GRN) inference analysis by using time-series RNA-seq data from developing hybrid seeds from a viable cross between Mimulus guttatus and Mimulus pardalis. GRN inference has the capacity to identify active regulatory mechanisms in a sample and highlight genes of potential biological importance. In our case, GRN inference also provided the opportunity to uncover active regulatory relationships and generate a reference set of putative gene regulations. We deployed two GRN inference algorithms—RTP-STAR and KBoost—on three different subsets of our transcriptomic dataset. While the two algorithms yielded GRNs with different regulations and topologies when working with the same data subset, there was still significant overlap in the specific gene regulations they inferred, and they both identified potential novel regulatory mechanisms that warrant further investigation.
Habitats, Plant Diversity, and Molecular Phylogeny of Endemic Relic Species Incarvillea semiretschenskia (Bignoniaceae)
Authors: Dimeyeva Liliya , Permitina Valeriya , Kurmantayeva Alfiya , Imanalinova Azhar , Osmonali Bektemir , Kozybayeva Farida , Beiseyeva Gulzhan , Ussen Kapar , Iskakov Rashid , Oyuntsetseg Batlai , Friesen Nikolai
Published: November 2024

Incarvillea semiretschenskia (B. Fedtsch.) Grierson is listed in the Red Data Book of Kazakhstan as a rare relic, narrowly endemic species of the Shu-Ile low mountains (Kazakhstan). The aim of this research was to advance our knowledge of the ecological conditions of its habitats, the floristic composition of plant communities, and molecular phylogeny, as well as to identify threats to the species’ existence. The ecological conditions of I. semiretschenskia habitats are rocky slopes and intermountain valleys of the low mountains in the altitude range from 812 to 1075 m asl with light chestnut mountain soils of little development, having a light granulometric composition and containing insignificant amounts of organic matter. We revealed 164 species of vascular plants in the communities of I. semiretschenskia, including five endemics and five species from the Red Data Book of Kazakhstan. Anthropogenic factors associated with grazing, fires, and limestone mining were identified as leading to a decrease in the number and density of populations. New insights into the relationship and time of diversification in the genus Incarvillea are gained through the use of several accessions of I. semiretschenskia and I. potaninii Batalin in the phylogenetic study. Preliminary fingerprint analysis shows relatively high genetic variability within populations of I. semiretschenskia. This unique relic species has survived since the Miocene epoch and exists to this day only in the Shu-Ile low mountains. To preserve this rare species, measures are proposed to create plant micro-reserves to provide ex situ collections and ensure future in situ restoration efforts.
Identification of miRNAs Involved in Lipid Metabolism and Tuber Development in Cyperus esculentus L.
Authors: Gao Yunfei , Wang Le , Cao Shanshan , Chen Liangyu , Li Xueying , Cong Weixuan , Yang Songnan , Zhang Jian , Nie Xiaojun , Zhang Jun
Published: November 2024

Tiger nut (Cyperus esculentus L.) is recognized for its high oil and oleic acid content in underground tubers. However, the molecular mechanisms governing growth, development, and fatty acid accumulation in these tubers are not well understood. This study employed gas chromatography–mass spectrometry (GC–MS) and small RNA sequencing on tiger nut tubers across five developmental stages. The findings indicate that the critical period for accumulating dry matter and oils, particularly oleic acid, occurs between 35 and 75 days after tuber formation. A total of 183 microRNAs (miRNAs) were identified, comprising 31 known and 152 novel miRNAs. Approximately half of these miRNAs (such as ces-miR156b-3p and ces-miR166a-3p) exhibited differential expression during and around the key periods of metabolite synthesis. The predicted target genes of these miRNAs were significantly enriched in glycerate 3-phosphate metabolism and cell growth processes. Furthermore, 13 miRNA–mRNA interaction modules related to oil accumulation and tuber growth were identified, and these target genes’ expression levels showed significant differences during the tuber developmental stages. These findings advance the understanding of the molecular mechanisms underlying tuber development and oil accumulation in tiger nut.
Electrochemical Reactions at the Boundary Areas Between Cold Atmospheric Pressure Plasma, Air, and Water
Authors: Thomas Jamiah , Volkov Alexander G.
Published: November 2024

A cold atmospheric-pressure He-plasma jet (CAPPJ) interacts with air and water, producing reactive oxygen and nitrogen species (RONS), including biologically active ions, radicals, and molecules such as NOx, H2O2, HNO3, HNO2, and O3. These compounds can activate interfacial redox processes in biological tissues. The CAPPJ can oxidize N2 to HNO3 and water to H2O2 at the interface between plasma and water. It can also induce the oxidation of water-soluble redox compounds in various organisms and in vitro. This includes salicylic acid, hydroquinone, and mixtures of antioxidants such as L (+)-ascorbic acid sodium salt with NADPH. It can react with redox indicators, such as ferroin, in a three-phase system consisting of air, CAPPJ, and water. Without reducing agents in the water, the CAPPJ will oxidize the water and decrease the pH of the solution. When antioxidants such as ascorbate, 1,4-hydroquinone, or NADPH are present in the aqueous phase, the CAPPJ oxidizes these substances first and then oxidizes water to H2O2. The multielectron mechanisms of the redox reactions in the plasma-air/water interfacial area are discussed and analyzed.
An Environmentally Friendly Superhydrophobic Wood Sponge with Photo/Electrothermal Effects Prepared from Natural Wood for All-Weather High-Viscosity Oil–Water Separation
Authors: Yang Kenan , Wang Sainan , Du Bin , Zhou Shisheng
Published: November 2024

Rapid industrial development has led to increased crude oil extraction and oily wastewater discharge. Achieving oil–water separation and marine oil adsorption in a cost-effective, efficient, and environmentally friendly manner remains a global challenge. In this work, natural wood was chemically treated to prepare a degradable and environmentally friendly wood sponge structure. In situ polymerization and spraying methods were used to produce an environmentally friendly oil–water separation sponge with superhydrophobic and superoleophilic properties (Fe3O4@P-P@WS). Fe3O4@P-P@WS had excellent superhydrophobicity (WCA = 154.2°) and self-cleaning properties. Additionally, Fe3O4@P-P@WS could convert solar and electrical energy into thermal energy, reaching a surface temperature of 74 °C under sunlight irradiation with an intensity of 1.0 kW m−2. When a voltage of 9 V was applied, the surface temperature reached 120.5 °C. Moreover, under the suction of a vacuum pump or the action of gravity, the continuous separation of highly fluid oil substances was achieved. The designed Fe3O4@P-P@WS offers advantages such as easily obtained raw materials, energy efficiency, simple preparation, and the ability to solve secondary pollution issues, providing a new technology for cleaning organic matter in industrial wastewater discharge and for round-the-clock cleaning of high-viscosity crude oil leaked during offshore oil exploitation.
Eco-Friendly Hydrogel Beads from Seashell Waste for Efficient Removal of Heavy Metals from Water
Authors: Mchich Zaineb , Stefan Daniela Simina , Mamouni Rachid , Saffaj Nabil , Bosomoiu Magdalena
Published: November 2024

The objective of this study is to develop a calcium carbonate-based adsorbent derived from Cellana Tramoscrica seashells, incorporated into a sodium alginate matrix (Na-Alg@CTs) to form hydrogel beads, for the efficient removal of Cu (II) and Zn (II) heavy metals from aqueous solutions. XRD, SEM/EDS, and FTIR analysis confirm the successful synthesis and characterization of the fabricated adsorbent. The adsorption study of Cu (II) and Zn (II) onto Na-Alg@CTs hydrogel beads revealed that the Langmuir model was the most suitable for characterizing the adsorption isotherms, suggesting monolayer coverage. Na-Alg@CTs exhibited a maximum Langmuir adsorption capacity of 368.58 mg/g and 1075.67 mg/g for Cu (II) and Zn (II), respectively. Additionally, the kinetics followed the pseudo-second-order model, indicating that the adsorption process is primarily governed by chemisorption. The thermodynamic study suggests that the uptake of metal ions on Na-Alg@CTs hydrogel beads is spontaneous and endothermic. The exceptional adsorption capacity, eco-friendly nature, and low-cost characteristics of Na-Alg@CTs hydrogel beads make them an ideal adsorbent for the removal of Cu (II) and Zn (II) from wastewater.
A 11B-NMR Method for the In Situ Monitoring of the Formation of Dynamic Covalent Boronate Esters in Dendrimers
Authors: Yao Yi-Wen , Tsai Ching-Hua , Liu Chih-Yi , Wang Fang-Yu , Hsu Sodio C. N. , Lin Chun-Cheng , Chen Hui-Ting , Kao Chai-Lin
Published: November 2024

The in situ monitoring of dynamic covalent macromolecular boronate esters represents a difficult task. In this report, we present an in situ method using fluoride coordination and 11B NMR spectroscopy to determine the amount of boronate esters in a mixture of boronic acids and cis-diols. With fluoride coordination, the boronic acid and boronate esters afforded trifluoroborate and fluoroboronate esters, giving identical resonances at 3 and 9 ppm in the 11B NMR spectra. The same titration did not alter the resonance of amine-coordinated boronate esters, which gave resonances of 14 ppm in the 11B NMR spectra. Therefore, boronic acids, boronate esters, and amine-coordinated boronate esters gave three identical resonances, and the ratio of each component was obtained by deconvolution for a further equilibrium analysis. This method monitored the conversion among three species in various conditions, including separation. Accordingly, boronate esters were more stable after precipitation than chromatography, in which 29% and 20% of boronate esters were lost after purification. This method was applied to study the reaction between the boronic acid-decorated defect lysine dendron (16) and dopamine. No boronic acid signal was observed after adding 1 equivalent of dopamine; no boronic acid signal was observed in the NMR spectrum. According to the spectrum, the product contains 65% boronate ester and 35% N–B-coordinated derivatives. This method helps identify the presence of the three intermediates and provides more insights into this reaction.
Investigation of Wettability, Thermal Stability, and Solar Behavior of Composite Films Based on Thermoplastic Polyurethane and Barium Titanate Nanoparticles
Authors: Kanmaz Dilayda , Celen Rumeysa , Karaca Esra , Manasoglu Gizem
Published: November 2024

Herein, composite films were produced by incorporating different amounts (1, 3, 5, and 7%) of barium titanate nanoparticles into the thermoplastic polyurethane matrix using a solution casting method. This study examined the impact of the presence and concentration of a barium titanate additive on morphologic properties, mechanical performance, thermal stability, solar behavior, and wettability of produced film samples. The films were characterized by Fourier transform infrared spectroscopy, differential scanning calorimetry, thermal gravimetric analysis, scanning electron microscope, ultraviolet-visible near-infrared spectrophotometer, water contact angle, and tensile strength measurements. In the present study, the mass loss of samples containing 7% barium titanate was 24% lower than that of the pure polyurethane reference. The increase of barium titanate rate added to polyurethane enhanced the solar reflectance property of the films, including the near-infrared region. As a prominent result, the transmittance value decreased significantly compared to the reference in the ultraviolet region, and it dropped to 3% for the highest additive concentration. The contact angle values of polyurethane films increased by 11–40% depending on the barium titanate addition ratio. The nano additive also positively affected the mechanical performance of the reference polyurethane film by slightly increasing the tensile strength values.
Study on Acoustic Emission Characteristics and Damage Mechanism of Wind Turbine Blade Main Spar with Different Defects
Authors: Zhang Yanan , Xue Shaojie , Chen Chuanyong , Ma Tianchang , Zhou Bo
Published: November 2024

This paper aimed to understand the AE signal characteristics and damage mechanism of wind turbine blade main spar materials with different defects during the damage evolution process. According to the typical delamination and wrinkle defects in wind turbine blades, the GFRP composite with defects is artificially prefabricated. Through acoustic emission experiments, the mechanical properties and acoustic emission characteristic trends of wind turbine blade main spar composites with different defects under tensile loading conditions were analyzed, and the damage evolution mechanism of different defects was explained according to the microscopic results. The results show that the existence of artificial defects will not only affect the mechanical properties of composite materials but also affect the damage evolution process of the materials. The size and location of delamination defects and the different aspect ratio of the wrinkle defects have a certain influence on the damage mechanism of the material. K-means cluster analysis of AE parameters identified the damage models of GFRP composites. The types of damage modes of delamination defects and wrinkle defects are the same, and the range of characteristic frequency is roughly the same. This study has important reference significance for structural damage monitoring and damage evolution research of wind turbine blade composites.
Radiographic Inspection of Carbon Fiber-Reinforced Polymer Composites (Laminates) with Epoxy and PEEK Binders After Impact and Subsequent Compression Loading
Authors: Kosmachev Pavel V. , Stepanov Dmitry Yu. , Tyazhev Anton V. , Vinnik Alexander E. , Eremin Alexander V. , Tolbanov Oleg P. , Panin Sergey V.
Published: November 2024

An approach to detecting discontinuities in carbon fiber-reinforced polymers, caused by impact loading followed by compression testing, was developed. An X-ray sensor-based installation was used, while some algorithms were developed to improve the quality of the obtained low-contrast radiographic images with negligible signal-to-noise ratios. For epoxy/AF (#1) composite subjected to a “high-velocity” steel-ball impact with subsequent compression loading, it was not possible to detect discontinuities since the orientation of the extended zone of interlayer delamination was perpendicular to the irradiation axis. After drop-weight impacts with subsequent compression loading of epoxy/CF (#2) and PEEK/CF (#3) composites, the main cracks were formed in their central parts. This area was reliably detected through the improved radiographic images being more contrasted compared to that for composite #3, for which the damaged area was similar in shape but smaller. The phase variation and congruency methods were employed to highlight low-contrast objects in the radiographic images. The phase variation procedure showed higher efficiency in detecting small objects, while phase congruency is preferable for highlighting large objects. To assess the degree of image improvement, several metrics were implemented. In the analysis of the model images, the most indicative was the PSNR parameter (with a S-N ratio greater than the unit), confirming an increase in image contrast and a decrease in noise level. The NIQE and PIQE parameters enabled the correct assessment of image quality even with the S-N ratio being less than a unit.
Naphthalene-Containing Epoxy Resin: Phase Structure, Rheology, and Thermophysical Properties
Authors: Ilyina Svetlana O. , Gorbunova Irina Y. , Yadykova Anastasiya Y. , Vlasova Anna V. , Kerber Michael L. , Ilyin Sergey O.
Published: November 2024

Naphthalene is a fungicide that can also be a phase-change agent owing to its high crystallization enthalpy at about 80 °C. The relatively rapid evaporation of naphthalene as a fungicide and its shape instability after melting are problems solved in this work by its placement into a cured epoxy matrix. The work’s research materials included diglycidyl ether of bisphenol A as an epoxy resin, 4,4′-diaminodiphenyl sulfone as its hardener, and naphthalene as a phase-change agent or a fungicide. Their miscibility was investigated by laser interferometry, the rheological properties of their blends before and during the curing by rotational rheometry, the thermophysical features of the curing process and the resulting phase-change materials by differential scanning calorimetry, and the blends’ morphologies by transmission optical and scanning electron microscopies. Naphthalene and epoxy resin were miscible when heated above 80 °C. This fact allowed obtaining highly concentrated mixtures containing up to 60% naphthalene by high-temperature homogeneous curing with 4,4′-diaminodiphenyl sulfone. The initial solubility of naphthalene was only 19% in uncured epoxy resin but increased strongly upon heating, reducing the viscosity of the reaction mixture, delaying its gelation, and slowing cross-linking. At 20–40% mass fraction of naphthalene, it almost entirely retained its dissolved state after cross-linking as a metastable solution, causing plasticization of the cured epoxy polymer and lowering its glass transition temperature. At 60% naphthalene, about half dissolved within the cured polymer, while the other half formed coarse particles capable of crystallization and thermal energy storage. In summary, the resulting phase-change material stored 42.6 J/g of thermal energy within 62–90 °C and had a glass transition temperature of 46.4 °C at a maximum naphthalene mass fraction of 60% within the epoxy matrix.
Electropolymerization of s-Triazines and Their Charge Storage Performance in Aqueous Acidic Electrolytes
Authors: Pei Shaotong , Lan Bo , Bai Xueting , Liu Yunpeng , Li Xinyang , Wang Chao
Published: November 2024

Designing novel π-conjugated conductive polymers with abundant redox-active groups is a viable route to achieve high charge storage performance for aqueous energy storage devices. Electropolymerization is a powerful tool to construct conductive polymers. Here, s-triazine is, for the first time, electropolymerized in an aqueous acidic solution on carbon cloth. The polytriazine-coated carbon cloth electrode (PT/CC) exhibits a granular structure, with abundant pores. The charge storage performance is investigated, and a specific capacity of 101.4 mAh g−1 at 1 A g−1 in 1 M H2SO4 is achieved. Additionally, in 1 M ZnSO4, a specific capacity of 50.3 mAh g−1 at 1 A g−1 can be achieved by the PT/CC. The PT/CC behaves as a battery-type charge storage electrode, and the amino/imino and carbonyl/hydroxyl groups contribute to the charge storage, with cation insertion and extraction. A symmetric aqueous charge storage device assembled with two PT/CC electrodes exhibits an energy density of 12.92 Wh kg−1 and a power density of 250 W kg−1 at 1 A g−1. After 2500 cycles at 10 A g−1, the device retains a specific capacity of 83.3%. This study indicates that the PT is a potential candidate material for an aqueous energy storage device.
Recent Advancements in Fabrication, Separation, and Purification of Hierarchically Porous Polymer Membranes and Their Applications in Next-Generation Electrochemical Energy Storage Devices
Authors: Cheng Xiong , Bae Joonho
Published: November 2024

In recent years, hierarchically porous polymer membranes (HPPMs) have emerged as promising materials for a wide range of applications, including filtration, separation, and energy storage. These membranes are distinguished by their multiscale porous structures, comprising macro-, meso-, and micropores. The multiscale structure enables optimizing the fluid dynamics and maximizing the surface areas, thereby improving the membrane performance. Advances in fabrication techniques such as electrospinning, phase separation, and templating have contributed to achieving precise control over pore size and distribution, enabling the creation of membranes with properties tailored to specific uses. In filtration systems, these membranes offer high selectivity and permeability, making them highly effective for the removal of contaminants in environmental and industrial processes. In electrochemical energy storage systems, the porous membrane architecture enhances ion transport and charge storage capabilities, leading to improved performance in batteries and supercapacitors. This review highlights the recent advances in the preparation methods for hierarchically porous structures and their progress in electrochemical energy storage applications. It offers valuable insights and references for future research in this field.
Progress in Flexible and Wearable Lead-Free Polymer Composites for Radiation Protection
Authors: Wu Shouying , Zhang Wei , Yang Yumin
Published: November 2024

The rapid development of nuclear technology has brought convenience to medical, industrial, and military fields. However, long-term exposure to a radiation environment with high energy will result in irreversible damage, especially to human health. Traditional lead-based radiation protection materials are heavy, inflexible, inconvenient for applications, and could lead to toxicity hazards and environmental problems. Therefore, it has become a mainstream topic to produce high-performance shielding materials that are lightweight, flexible, and wearable. Polymer composites are less dense and have excellent flexibility and processability, drawing great interest from researchers worldwide. Many attempts have been made to blend functional particles and polymeric matrix to produce flexible and wearable protection composites. This paper presents an extensive overview of the current status of studies on lead-free polymer composites as flexible and wearable protection materials. First, novel functional particles and polymer matrices are discussed, and recent results with potential applications are summarised. In addition, novel strategies for preparing polymeric shielding materials and their respective radiation shielding properties are analyzed. Finally, directions for developing lead-free polymeric shielding materials are indicated, and it is beneficial to provide additional references for obtaining flexible, lightweight, and high-performance wearable shielding materials.
Click Chemistry for Well-Defined Graft Copolymers
Authors: Ali Muhammad Faizan , Ochiai Bungo
Published: November 2024

Graft copolymers have gained significant importance in various fields due to their tunable functionality and well-defined architecture. However, there are still limitations due to the compatibility of monomers and functional groups depending on the polymerization mode. Click chemistry has solved this problem through its ability to easily and quantitatively link a wide range of polymers and functional groups. The combination of click chemistry, including copper-catalyzed azide-alkyne cycloaddition (CuAAC), thiol-ene, and thiol-yne reactions, with various polymerization techniques offers a promising solution for the robust and efficient preparation of graft copolymers with the desired architecture and functionality. In this review, we present successful applications of click chemistry in the production of well-defined graft copolymers with diverse functionalities such as for electronics, energy devices, biomedical applications, and nanotechnology.
Polypyrrole-Derived Nitrogen-Doped Tubular Carbon Materials as a Promising Cathode for Aqueous Aluminum-Ion Batteries
Authors: Zhou Xiaoming , Li Xiaolei , Duan Jiaming , Zhang Lihao , Mo Xinyu , Wu Qing , Liu Yang , Yuan Guohui , Yang Miaosen
Published: November 2024

The advantages of aluminum-ion batteries in the area of power source systems are: inexpensive manufacture, high capacity, and absolute security. However, due to the limitations of cathode materials, the capacity and durability of aluminum-ion batteries ought to be further advanced. Herein, we synthesized a nitrogen-doped tubular carbon material as a potential cathode to achieve advanced aqueous aluminum-ion batteries. Nitrogen-doped tubular carbon materials own an abundant space (367.6 m2 g−1) for electrochemical behavior, with an aperture primarily concentrated around 2.34 nm. They also exhibit a remarkable service lifespan, retaining a specific capacity of 78.4 mAh g−1 at 50 mA g−1 after 300 cycles. Additionally, from 2 to 300 cycles, the material achieves an appreciable reversibility (coulombic efficiency CE: 99.7%) demonstrating its excellent reversibility. The tubular structural material possesses a distinctive hollow architecture that mitigates volumetric expansion during charging and discharging, thereby preventing structural failure. This material offers several advantages, including a straightforward synthesis method, high yield, and ease of mass production, making it highly significant for the research and development of future aluminum-ion batteries.
Support-Free Low-Temperature Laser-Based Powder Bed Fusion of Polymers Using a Semi-Sintering Process
Authors: Kobayashi Ryuichi , Kigure Takashi , Yamauchi Yuki
Published: November 2024

In conventional laser-based powder bed fusion of polymers (PBF-LB/P), aging of the powder due to preheating of the powder bed is a significant issue. This paper proposes a method for low-temperature PBF-LB/P using a semi-sintering process that minimizes powder aging caused by preheating. By partially semi-sintering the low-temperature powder bed, it was possible to execute the PBF-LB/P while avoiding the aging of most of the powder. Furthermore, the suppression of curling by the semi-sintered body eliminated the need to connect the base plate to the parts, which was necessary in previously reported low-temperature PBF-LB/P. Using the semi-sintering process, we successfully built cuboid and tensile test specimens in a polyamide 11 powder bed maintained below the crystallization temperature, where the powder hardly aged. The apparent densities of the built specimens were comparable to those produced using high-temperature PBF-LB/P. However, the elongation in the building direction of the built parts by the semi-sintering process should be improved. This study represents the first step toward the practical application of low-temperature PBF-LB/P using semi-sintering.
Immobilization of Naringinase onto Polydopamine-Coated Magnetic Iron Oxide Nanoparticles for Juice Debittering Applications
Authors: Kimmins Scott D. , Henríquez Antonella , Torres Celia , Wilson Lorena , Flores Marcos , Pio Edgar , Jullian Domingo , Urbano Bruno , Braun-Galleani Stephanie , Ottone Carminna , Muñoz Lisa , Claros Martha , Urrutia Paulina
Published: November 2024

Chemical amination of the enzyme was demonstrated to favor immobilization onto polydopamine (PDA)-coated magnetic nanoparticles (MNPs) for the first time, to the best of the author’s knowledge. MNPs prepared via hydrothermal synthesis were coated with PDA for the immobilization of naringinase. X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectroscopy, and Fourier-transform infrared spectroscopy showed that the MNPs were composed mainly of Fe3O4 with an average size of 38.9 nm, and coated with a 15.1 nm PDA layer. Although the specific activities of α-L-rhamnosidase (RAM) and β-D-glucosidase (GLU) of free naringinase decreased with amination, the immobilization yields of the aminated enzyme increased by more than 40% for RAM and more than 10-fold for GLU. The immobilization improved the enzyme’s thermal stability (at 50 °C), reaching a half-life of 40.7 and 23.1 h for RAM and GLU activities, respectively. The biocatalyst was successfully used for the debittering of grapefruit juice, detecting a reduction in naringin of 56% after 24 h. These results demonstrate that the enzyme amination is an effective strategy to enhance the immobilization on a PDA coating and could be applied to other enzymes in order to obtain an easily recoverable biocatalyst using a simple immobilization methodology.
Polymer Composites Reinforced with Residues from Amazonian Agro-Extractivism and Timber Industries: A Sustainable Approach to Enhancing Material Properties and Promoting Bioeconomy
Authors: Leite-Barbosa Odilon , Pinto Claúdia Carnaval de Oliveira , Leite-da-Silva Jôse Maria , de Aguiar Erick Max Mourão Monteiro , Veiga-Junior Valdir Florencio
Published: November 2024

The Amazon Region (AR), with its vast biodiversity and rich natural resources, presents a unique opportunity for the development of sustainable polymer composites (PCs) reinforced with residues from both timber and agro-extractivism industries. This study explores the potential of Amazonian residues, such as sawdust, wood shavings, and agro-industrial by-products such as açaí seeds and Brazil nut shells, to enhance the mechanical, thermal, and environmental properties of polymer composites. By integrating these natural materials into polymer matrices, significant improvements in the composite performance were achieved, including increased tensile strength, thermal stability, and biodegradability. The study also highlights the environmental and economic benefits of using these residues, promoting waste reduction and supporting a circular economy in the region. Through case studies and detailed analyses, this study demonstrates the feasibility and advantages of incorporating Amazonian residues into composites for a wide range of applications, from construction materials to consumer goods. This approach not only adds value to the by-products of Amazonian industries, but also contributes to the global effort toward sustainable material development.
Analysis and Prediction of Temperature Using an Artificial Neural Network Model for Milling Glass Fiber Reinforced Polymer Composites
Authors: Spanu Paulina , Abaza Bogdan Felician , Constantinescu Teodor Catalin
Published: November 2024

Milling parts made from glass fiber-reinforced polymer (GFRP) composite materials are recommended to achieve the geometric shapes and dimensional tolerances required for large parts manufactured using the spray lay-up technique. The quality of the surfaces machined by milling is significantly influenced by the temperature generated in the cutting zone. This study aims to develop an Artificial Neural Network (ANN) model to predict the temperature generated when milling GFRP. The ANN model for temperature prediction was created using a virtual instrument developed in the graphical programming language LabVIEW. Predicting temperature is crucial because excessive heat during milling can lead to several issues, such as tool wear and thermal degradation in the polymer matrix. The temperature in the tool–workpiece contact surface during the milling process was measured using a thermography technique with a ThermaCAM SC 640 camera (provided by FLIR Systems AB, Danderyd, Sweden), and the data were analyzed using the ThermaCAM Researcher Professional 2.8 SR-2 software. Experimental research shows that the cutting speed has a much more significant effect on the temperature in the cutting zone compared to axial depth of cut and feed speed. The maximum temperature of 85.19 °C was measured in the tool–workpiece contact zone during machining at a cutting speed of 75.39 m/min, a feed rate of 250 mm/min, and an axial depth of cut of 12 mm. This temperature rise occurred due to the larger contact area and heightened friction resulting from the abrasive characteristics of the reinforcement material.