bluuebunny/crossref_metadata_2025 huggingface dataset:
Circadian Influences on Brain Lipid Metabolism and Neurodegenerative Diseases
Authors: Hussain Yusuf , Dar Mohammad Irfan , Pan Xiaoyue
Published: December 2024

Circadian rhythms are intrinsic, 24 h cycles that regulate key physiological, mental, and behavioral processes, including sleep–wake cycles, hormone secretion, and metabolism. These rhythms are controlled by the brain’s suprachiasmatic nucleus, which synchronizes with environmental signals, such as light and temperature, and consequently maintains alignment with the day–night cycle. Molecular feedback loops, driven by core circadian “clock genes”, such as Clock, Bmal1, Per, and Cry, are essential for rhythmic gene expression; disruptions in these feedback loops are associated with various health issues. Dysregulated lipid metabolism in the brain has been implicated in the pathogenesis of neurological disorders by contributing to oxidative stress, neuroinflammation, and synaptic dysfunction, as observed in conditions such as Alzheimer’s and Parkinson’s diseases. Disruptions in circadian gene expression have been shown to perturb lipid regulatory mechanisms in the brain, thereby triggering neuroinflammatory responses and oxidative damage. This review synthesizes current insights into the interconnections between circadian rhythms and lipid metabolism, with a focus on their roles in neurological health and disease. It further examines how the desynchronization of circadian genes affects lipid metabolism and explores the potential mechanisms through which disrupted circadian signaling might contribute to the pathophysiology of neurodegenerative disorders.
Antioxidant and Antibacterial Activities of Chinese Native Thyme Essential Oils with Different Chemotypes
Authors: Sun Meiyu , Zhang Yanan , Hao Yuanpeng , Miao Jiahui , Sun Guofeng , Xiao Jianhua , Yang Xiao , Zhang Jinzheng , Shi Lei
Published: December 2024

Thyme essential oils (EOs) have antioxidant, antiviral, antifungal, antibacterial, anti-inflammatory, and immunological properties and are used in medicine, food, feed additives, and cosmetics. Here, we made use of a multidimensional analytical method to analyze the differences in the chemical components, chemotypes, and antioxidant and antibacterial activities of EOs from 24 Chinese native thymes. These Chinese native thymes comprised 10 species (Thymus quinquecostatus, T. mongolicus, T. inaequalis, T. mandschuricus, T. curtus, T. amurensis, T. roseus, T. proximu, T. marschallianus, and T. altaicus) and two varieties (T. quinquecostatus var. asiaticus and T. quinquecostatus var. przewalskii). Four primary chemotype groups were identified, namely carvacrol, thymol, geraniol, and α-terpineol. The maximum carvacrol, thymol, geraniol, and α-terpineol contents were 72.4, 58.6, 59.5, and 65.4%, respectively. The antioxidant capacities of the thymol and carvacrol chemotype EOs were found to be significantly superior to the other chemotypes using three antioxidant assays: DPPH, ABTS, and FRAP. Moreover, the thymol and carvacrol EO chemotypes could significantly inhibit the growths of the common food-borne pathogenic bacteria Staphylococcus aureus and Escherichia coli. A correlation analysis between the EO components and the bacteria showed that thymol significantly positively correlated with the bacteria. In summary, we analyzed the thyme EOs’ antioxidant and antibacterial activities, which laid a foundation for their use in medicines, foods, feed additives, and cosmetics. The results will also be very useful for the selection of wild thymes for functional research on carvacrol-, thymol-, geraniol-, and α-terpineol-rich essential oil chemotypes and the product development of feed additives, cosmetics, etc.
α-Tocopherol and Trolox as Effective Natural Additives for Polyurethane Foams: A DFT and Experimental Study
Authors: Thbayh Dalal K. , Mentes Dóra , Boros Zsanett R. , Palusiak Marcin , Farkas László , Viskolcz Béla , Fiser Béla
Published: December 2024

In this work, α-tocopherol and trolox were studied as compounds that have high biological activity. α-Tocopherol is considered a food additive because the refining process of vegetable oils causes the depletion of this vitamin, and thus, its inclusion is required to keep them from oxidizing. Computational tools have determined the antioxidant activity of these additives. The geometries of the studied molecules were optimized using two density functional methods, including M05-2X and M06-2X, in combination with the 6-311++G(2d,2p) basis set. The results indicated that when comparing the antioxidant activity of α-tocopherol and trolox, they were very similar to each other, but α-tocopherol had an antioxidant activity slightly higher, around 1.2 kJ/mol, than trolox. Thus, these additives can be used as polymer additives to protect materials from free-radical-induced stress. To test their applicability in polymeric formulations, flexible polyurethane foams were prepared with varying α-tocopherol ratios and NCO indices (1.0 and 1.1). Increasing the α-tocopherol content reduced the compressive force and altered the mechanical properties, likely due to its presence in the foam structure. This additive not only fine-tuned the mechanical properties but also provided antioxidant effects, enabling multiple enhancements in polymeric products with a single additive.
Editorial for Special Issue: “Thin Films Based on Nanocomposites (2nd Edition)”
Authors: Socol Marcela , Preda Nicoleta
Published: December 2024

The continuous demand for multifunctional materials in industrial applications has driven the design of nanocomposites with new or enhanced properties [...]
Selective O2/N2 Separation Using Grazyne Membranes: A Computational Approach Combining Density Functional Theory and Molecular Dynamics
Authors: Calzada Adrià , Viñes Francesc , Gamallo Pablo
Published: December 2024

The separation of oxygen (O2) and nitrogen (N2) from air is a process of utmost importance nowadays, as both species are vital for numerous fundamental processes essential for our development. Membranes designed for their selective molecule separation have become the materials of choice for researchers, primarily due to their ease of use. The present study proposes grazynes, 2D carbon-based materials consisting of sp and sp2 C atoms, as suitable membranes for separating O2 and N2 from air. By combining static density functional theory (DFT) calculations with molecular dynamics (MD) simulations, we address this issue through a comprehensive examination of the thermodynamic, kinetic, and dynamic aspects of the molecular diffusions across the nano-engineered pores of grazynes. The studied grazyne structures have demonstrated the ability to physisorb both O2 and N2, preventing material saturation, with diffusion rates exceeding 1 s−1 across a temperature range of 100–500 K. Moreover, they exhibit a selectivity of ca. 2 towards O2 at 300 K. Indeed, MD simulations with equimolar mixtures of O2:N2 indicated a selectivity towards O2 in both grazynes with ca. twice as many O2 filtered molecules in the [1],[2]{2}-grazyne and with O2 representing ca. 88% of the filtered gas in the [1],[2]{(0,0),2}-grazyne. [1],[2]{2}-grazyne shows higher permeability for both molecules compared to the other grazyne, with O₂ demonstrating particularly enhanced diffusion capacity across both membranes. Further MD simulations incorporating CO2 and Ar confirm O2 enrichment, particularly with [1],[2]{(0,0),2}-grazyne, which increased the presence of O2 in the filtered mixture by 26% with no evidence of CO2 molecules.
Long-Term Follow-Up After Bariatric Surgery: Key to Successful Outcomes in Obesity Management
Authors: Budny Aleksandra , Janczy Agata , Szymanski Michal , Mika Adriana
Published: December 2024

Background/Objectives: Bariatric surgery (BS) is considered one of the most effective interventions for the treatment of obesity. To achieve optimal long-term results, continuous follow-up (FU) within a multidisciplinary treatment team is essential to ensure patient compliance and maximize the benefits of BS. However, many patients find it difficult to maintain regular FU, which can affect the quality of care and lead to postoperative complications. This review aims to highlight factors that may hinder compliance with FU after BS, examine potential causes and consequences of inadequate FU, and identify strategies to improve patient participation in long-term FU. Methods: The literature search was conducted between October 2023 and June 2024 in Medline (PubMed) and the Cochrane Library datasets. Studies were selected for their relevance to adherence to FU, multidisciplinary approaches, and long-term bariatric outcomes. Results: The pre- and postoperative period is critical for educating patients and healthcare team members about the importance of FU, addressing potential barriers (e.g., logistical, psychological, and social challenges), and highlighting the risk of relapse to obesity after surgery. The lack of a standardized FU protocol leads to differences between medical centers, further impacting patient adherence. Conclusions: Tailored and regularly updated strategies are essential to address individual patient needs and improve adherence to FU. Further research is needed to identify the specific factors that influence variability in long-term BS outcomes, highlighting the need for a patient-centered approach to obesity treatment.
Factors Associated with the Prolonged Use of Donor Human Milk at the Da Nang Hospital for Women and Children in Vietnam
Authors: Tran Hoang Thi , Nguyen Tuan Thanh , Nguyen Oanh Thi Xuan , Huynh Le Thi , Mathisen Roger
Published: December 2024

Background and Objectives: Donor human milk (DHM) from a human milk bank (HMB) is used to feed low-birthweight (LBW) and preterm infants when mothers cannot provide their own breastmilk. The misuse of DHM could interfere with mothers’ breastmilk and weaken breastfeeding efforts. This study aimed to identify factors behind prolonged DHM usage during the first six years of Vietnam’s first HMB. Methods: Data were extracted from the Da Nang HMB’s digital monitoring system. We defined prolonged DHM use as four or more days in the neonatal unit and two or more days in postnatal wards. Results: Over six years, 25,420 infants received DHM, with 45.3% of the infants being female, 54.7% being male, 70.0% being born via cesarean section, and 77.2% being full-term. In the neonatal unit (n = 7001), 38.0% of infants used DHM for ≥4 days. Adjusted odds ratios (aORs) for prolonged use were 0.14 for infants weighing <1000 g, 0.78 for infants weighing 1000–<1500 g, and 0.67 for infants weighing ≥2000 g (p < 0.01), compared to those weighing 1500–<2000 g. Compared to gestational ages of 32–<34 weeks, the aORs were 0.26 for <28 weeks, 0.71 for 34–<37 weeks, and 0.35 for ≥37 weeks (p < 0.01). In postnatal wards (n = 18,419), 53.1% of infants used DHM for ≥2 days. Compared to term, normal-weight infants, the aORs were 1.25 for LBW–preterm, 1.17 for LBW–term, and 1.21 for normal-weight–preterm infants (p < 0.05). Prolonged DHM use was associated with cesarean births in neonatal units (aOR 2.24, p < 0.01) and postnatal wards (aOR 1.44, p < 0.01). Conclusions: DHM is used briefly to bridge nutritional gaps and transition to mothers’ breastmilk, but LBW, preterm births, and cesarean births are linked to prolonged use. Healthcare providers should support those at risk of prolonged DHM use and prioritize reducing unnecessary cesarean births.
The Critical Role of Lipid Metabolism in Health and Diseases
Authors: Zhu Yucheng , Wan Fangyan , Liu Jie , Jia Zhihao , Song Tongxing
Published: December 2024

Lipids make up 10–20% of the human body and serve as crucial energy storage substances as well as essential components of cell membranes [...]
Caryophylli Cortex Suppress PD-L1 Expression in Cancer Cells and Potentiates Anti-Tumor Immunity in a Humanized PD-1/PD-L1 Knock-In MC-38 Colon Cancer Mouse Model
Authors: Kim Aeyung , Lee Eun-Ji , Han Jung Ho , Chung Hwan-Suck
Published: December 2024

Background/Objectives: Immune checkpoints are essential for regulating excessive autoimmune responses and maintaining immune homeostasis. However, in the tumor microenvironment, these checkpoints can lead to cytotoxic T cell exhaustion, allowing cancer cells to evade immune surveillance and promote tumor progression. The expression of programmed death-ligand 1 (PD-L1) in cancer cells is associated with poor prognoses, reduced survival rates, and lower responses to therapies. Consequently, downregulating PD-L1 expression has become a key strategy in developing immune checkpoint inhibitors (ICIs). Caryophylli cortex (CC), derived from the bark of the clove tree Syzygium aromaticum, possesses antioxidant and cytotoxic properties against cancer cells, yet its potential as an ICI remains unclear. Methods: In this study, we aimed to investigate whether CC extract modulates PD-L1 expression in cancer cells and activates T cell immunity through a co-culture system of cancer cells and T cells, as well as in hPD-L1/MC-38 tumor-bearing animal models. Results: Our findings indicate that CC extract significantly downregulated both constitutive and inducible PD-L1 expression at non-toxic concentrations for cancer cells while simultaneously enhancing cancer cell mortality and T cell activity in the co-culture system. Furthermore, the administration of CC extract to hPD-L1/MC-38 tumor-bearing mice resulted in a greater than 70% reduction in tumor growth and increased infiltration of CD8+ T cells within the tumor microenvironment. Principal component analysis identified bergenin, chlorogenic acid, and ellagic acid as active ICIs. Conclusions: These findings suggest that CC extract exerts a potent antitumor effect as an immune checkpoint blocker by inhibiting PD-L1 expression in cancer cells and disrupting the PD-1/PD-L1 interaction.
Efficiency of Skeletal Muscle Mass/Weight Measurement for Distinguishing Metabolic Dysfunction-Associated Steatotic Liver Disease: A Prospective Analysis Using InBody Bioimpedance Devices
Authors: Tatsuta Miwa , Masaki Tsutomu , Kimura Shungo , Sato Yudai , Tomida Akemi , Ishikawa Ichiro , Nakamura Yu , Takuma Kei , Nakahara Mai , Oura Kyoko , Tadokoro Tomoko , Fujita Koji , Tani Joji , Morishita Asahiro , Himoto Takashi , Miyazaki Shinjiro , Maeta Tsuyoshi , Mori Yoshihiro , Kohi Fumikazu , Kobara Hideki
Published: December 2024

Background/Objectives: Metabolic dysfunction-associated steatotic liver disease (MASLD) is diagnosed when hepatic steatosis is proven by imaging and one of the five cardiometabolic criteria is present. The relationship between MASLD and body composition components has recently received increased research attention. However, the five cardiometabolic criteria do not include components of body composition. This study aimed to identify significant body composition factors associated with MASLD in patients undergoing health checkups. Methods: This study included a cohort of 6599 examinees who participated in a health check-up conducted between 2022 and 2023, and their data were prospectively analyzed. The inclusion criteria were undergoing abdominal ultrasonography, alcohol consumption <30 g/day for males or <20 g/day for females, and one of the five cardiometabolic criteria. Results: Finally, 3864 examinees were enrolled. In total, 1133 (51.8%) males and 454 (27.1%) females had MASLD. Sarcopenia was present in only 0.62% of males and 0.66% of females with MASLD. The MASLD group had significantly lower skeletal muscle mass/weight (SMM/WT) values than the non-MASLD group. Multivariate analysis revealed that SMM/WT was independently associated with MASLD. Conclusions: SMM/WT was significantly associated with MASLD. Therefore, muscle mass assessment using SMM/WT may be a potential marker for diagnosing MASLD.
Risk Factors Related to Resting Metabolic Rate-Related DNAJC6 Gene Variation in Children with Overweight/Obesity: 3-Year Panel Study
Authors: Shin Jieun , Kang Inhae , Lee Myoungsook
Published: December 2024

This study investigated how the DNACJ6 gene variation related to RMR alteration affects risk factors of obese environments in children with obesity aged 8–9. Methods: Over a three-year follow-up period, 63.3% of original students participated. Changes in the variables (anthropometrics, blood biochemistry, and dietary intakes) were analyzed and compared between those without obesity (non-OB) and with obesity (OB) classified at the study endpoint. Result: The average MAF of nine SNPs (D-1 to D-IX) was defined as 18.1%. The OB group showed greater increases in RMR, BMI, WC, and SBP, while the non-OB group had significantly greater increases in HDL and intakes of nutrients (e.g., total calories, vitamins B2, C, folate, A, retinol, iron, and zinc). Increased RMR, BMI, BW, and RMR/BW changes were observed with mutant allele of D-I SNP, which was also associated with a higher prevalence of obesity. Greater increases in animal fat intake, including saturated fatty acids and retinol, were noted in the minor alleles of D-VI, D-VII, D-VIII, and D-IX SNPs compared to those of the major alleles. The odds ratio for BMI risk was significantly higher in the mutant alleles of D-I (rs17127601), D-VII (rs1334880), and D-VIII (rs7354899) compared to the wild type, with increases of 2.59 times (CI; 1.068–6.274), 1.86 times (CI; 1.012–3.422), and 1.85 times (CI; 1.008–3.416), respectively. RMR was a mild risk factor in minors of the D-1, D-VII, and D-VIII; however, a higher RMR/BW ratio significantly correlated with decreased BMI risk, and this effect was found in only the major alleles of D-I, D-VII, and D-VIII SNPs, not in the minor alleles. High retinol intake appeared to reduce obesity risk in the minor alleles of the D-I, D-VII, and D-VIII SNPs, even though intake of animal fats and retinol remained higher among minors over the three years. Conclusions: These findings suggest that the RMR/BW ratio and dietary fat/retinol intake should be considered in DNACJ6-gene-based precision medicine approaches for pediatric obesity prevention, particularly for boys.
The Effects of Novel Co-Amorphous Naringenin and Fisetin Compounds on a Diet-Induced Obesity Murine Model
Authors: Vásquez-Reyes Sarai , Bernal-Gámez Miranda , Domínguez-Chávez Jorge , Mondragón-Vásquez Karina , Sánchez-Tapia Mónica , Ordaz Guillermo , Granados-Portillo Omar , Coutiño-Hernández Diana , Barrera-Gómez Paulina , Torres Nimbe , Tovar Armando R.
Published: December 2024

Background/Objective: In recent studies, it has been shown that dietary bioactive compounds can produce health benefits; however, it is not known whether an improvement in solubility can enhance their biological effects. Thus, the aim of this work was to study whether co-amorphous (CoA) naringenin or fisetin with enhanced solubility modify glucose and lipid metabolism, thermogenic capacity and gut microbiota in mice fed a high-fat, high-sucrose (HFSD) diet. Methods: Mice were fed with an HFSD with or without CoA-naringenin or CoA-fisetin for 3 months. Body weight, food intake, body composition, glucose tolerance, hepatic lipid composition and gut microbiota were assessed. Results: CoA-naringenin demonstrated significant reductions in fat-mass gain, improved cholesterol metabolism, and enhanced glucose tolerance. Mice treated with CoA-naringenin gained 45% less fat mass and exhibited improved hepatic lipid profiles, with significant reductions seen in liver triglycerides and cholesterol. Additionally, both CoA-flavonoids increased oxygen consumption (VO2), contributing to enhanced energy expenditure and improved metabolic flexibility. Thermogenic activation, indicated by increased UCP1 and PGC-1α levels, was observed with CoA-fisetin, supporting its role in fat oxidation and adipocyte size reduction. Further, both CoA-flavonoids modulated gut microbiota, restoring diversity and promoting beneficial bacteria, such as Akkermansia muciniphila, which has been linked to improved metabolic health. Conclusions: These findings suggest that co-amorphous naringenin or fisetin offers promising applications in improving solubility, metabolic health, and thermogenesis, highlighting the potential of both as therapeutic agents against obesity and related disorders.
Application of LC-MS/MS for the Identification of Drugs of Abuse in Driver’s License Regranting Procedures
Authors: Tittarelli Roberta , Stefani Lucrezia , Romani Leonardo , Mineo Federico , Vernich Francesca , Mannocchi Giulio , Pellecchia Maria Rosaria , Russo Carmelo , Marsella Luigi Tonino
Published: December 2024

Background: Drugged driving is associated with an increased risk of road accidents worldwide. In Italy, driving under the influence (DUI) of alcohol and drugs is a reason for driving disqualification or revocation of the driving license. Drivers charged with driving under the influence of alcohol and drugs must attend a Local Medical Commission (LMC) to undergo mandatory examinations to regain the suspended license. Our study mainly aims to report on the analysis performed on hair samples collected from 7560 drivers who had their licenses suspended for drugged or drunk driving between January 2019 and June 2024. Methods: A rapid, sensitive, and selective method for the determination of ethyl glucuronide in hair by UPLC/MS-MS was developed and fully validated. Results: The most frequently detected substances were cocaine (ecgonine methyl ester, norcocaine, and benzoylecgonine) and cannabinoids (Δ9-tetrahydrocannabinol, cannabidiol, and cannabinol), followed by opiates (codeine, morphine, and 6-MAM), methadone (EDDP), and amphetamines (amphetamine, methamphetamine, MDA, MDMA, and MDEA). To perform a more in-depth analysis, we also compared hair color with the drug classes that tested positive. The results showed a significant prevalence of dark hair that tested positive for one or more substances, followed by gray/white hair and light hair. Conclusions: Our study provides an interesting and alarming insight into drug exposure in the general population with serious public health threats, discussing the main aspects of hair matrix analysis and focusing on its advantages and reliability in the interpretation of results.
The Role of Curcumin in Preventing Naturally Occurring Leiomyoma in the Galline Model
Authors: Sahin Kazim , Orhan Cemal , Tuzcu Mehmet , Sahin Nurhan , Ozercan Ibrahim H. , Kabil Nashwa , Kucuk Omer , Ozpolat Bulent
Published: December 2024

Background: Leiomyoma (LM) is the most commonly identified tumor in the genital tract, occurring in 70–80% of women. The only treatment option is surgery, which significantly influences healthcare costs and negatively influences women’s survival and reproductive capacity. Therefore, identifying safe and effective chemopreventive and treatment modalities is needed. Methods: We investigated the effects of 12 months of daily curcumin (0, 25.8, and 53 mg/kg) diet on the incidence and growth of spontaneously developing LM tumors in a galline (hen) model. Results: LM tumors were detected in 58.9% (53/90) of the control hens as spontaneous occurrences, while they were observed in 37.7% (34/90) and 24.5% (22/90) of hens treated with daily doses of 25.8 mg or 53.0 mg, respectively, over 12 months. This reduced LM development by 35% and 58.5%, respectively (p = 0.004). We also observed a dose-dependent inhibition of LM-tumor growth and NF-κB, mTOR, p70S6K1, and 4E-BP1 signaling while inducing Nrf2/HO1 pathway induction LM tumors collected from hens fed with curcumin (p < 0.05). Curcumin intake notably reduced levels of TGF-β1, α-SMA, and collagen type 1, with dose-dependent effects (p < 0.001). Conclusions: The findings suggest that daily curcumin consumption significantly reduces the incidence of naturally occurring LMs and suppresses tumor growth. This indicates that regular curcumin intake may be an effective preventive measure against LMs.
Effect of Homologous and Heterologous Booster in COVID-19 Vaccination
Authors: Vukčević Marija , Despot Mateja , Nikolić-Kokić Aleksandra , Blagojević Duško , Nikolić Milan , Banko Ana , Jovanović Tanja , Despot Dragana
Published: December 2024

Background: COVID-19 became a global health crisis in early 2020, and the way out of the crisis was the rapid development of vaccines by Sinopharm, Pfizer, and Sputnik, among others, which played a crucial role in controlling the pandemic. Therefore, this study aims to investigate the long-term immune response by measuring the levels of anti-S1 IgG antibodies induced by homologous and heterologous vaccination regimens. Methods: We investigated the titer of the anti-S1 IgG antibody produced for the viral surface antigen 3, 6 months after the second dose, before the third dose, and 1, 3, and 6 months after the third dose. Results: Anti-S1 IgG antibody levels significantly increased three/six months after the second dose and following the booster in individuals without prior COVID-19 infection who received all three homologous vaccine doses. The group that initially responded poorly to Sinopharm showed a significant and sustained increase after receiving the Pfizer booster. Additionally, prior SARS-CoV-2 infection between primary and booster vaccination boosted anti-S1 antibody titers in all individuals, regardless of the vaccine used. The highest vaccine efficacy was observed during the primary vaccination period and declined over time, especially during the omicron-dominant period. Conclusions: The results suggest that while homologous and heterologous booster doses can significantly enhance anti-S1 IgG antibody levels, prior SARS-CoV-2 infection and the type of vaccine administered influence the duration and magnitude of the immune response.
The Global Advance of Genome-Edited Plants to the Market: The Key Role of Chile in Its Development
Authors: Sánchez Miguel A.
Published: December 2024

The global advancement of genome-edited plants toward commercialization has been significantly shaped by the functionality and flexibility of some regulatory frameworks governing plant genome editing. These frameworks vary widely across countries, reflecting diverse approaches to assessing and managing the risks and benefits of genome-editing technologies. While some nations have adopted product-based frameworks that focus on the characteristics of the final plant rather than the technique used, others rely on more restrictive process-based regulations. This variability influences the pace of innovation, the types of products able to enter the market, and their global trade potential. Chile stands out as a leader in this landscape, having implemented a science-driven and flexible regulatory framework. Its system promotes innovation by facilitating genome-edited plant research and development, field testing, and local commercialization. This regulatory adaptability positions Chile as a critical player in supporting the global integration of genome-editing technologies into agriculture, fostering advancements that address food security, sustainability, and climate resilience.
Thermally Healable Polyurethane Elastomers Based on Biomass Polyester Polyol from Isosorbide and Dimer Fatty Acid
Authors: Shin Se-Ra , Lee Dai-Soo
Published: December 2024

A fully bio-based polyester polyol based on isosorbide (ISB) and dimer fatty acid (DA) was synthesized through esterification. An ISB-based polyester polyol (DIS) was developed to synthesize a bio-based polyurethane elastomer (PUE) with enhanced mechanical and self-healing properties. The rigid bicyclic structure of ISB improved tensile properties, while the urethane bonds formed between the hydroxyl groups in ISB and isocyanate exhibited reversible characteristics at elevated temperatures, significantly enhancing the self-healing performance of DIS-based PUE compared to the control PUE (self-healing efficiency: 98% for DIS-based PUE vs. 65% for control PUE). The dynamic mechanical and rheological properties of DIS-based PUE were investigated to confirm their relationship with self-healing performance. The DIS-based PUE, featuring reversible urethane bonds, demonstrated rapid stress relaxation and maintained constant normal stress under external stimuli, contributing to its improved self-healing capabilities. Thus, ISB can be regarded as a promising bio-resource for synthesizing bio-based polyester polyols and, consequently, PUE with superior mechanical and self-healing properties.
Effect of High-Energy Electron Beam Irradiation on the Structure and Thermoelectric Properties of Polypyrrole
Authors: Shang Jie , He Jia , Xu Ziheng , Zeng Yufeng , Wang Yihan , Zhang Kun
Published: December 2024

The effects of different doses (10–100 kGy) of electron beams on the molecular structure, microstructure, and thermoelectric properties of polypyrrole (PPy) under high-energy electron beam irradiation (10 MeV) were studied. The results showed that after electron beam irradiation, the conductivity of PPy increased slightly, but the Seebeck coefficient and power factor remained relatively stable. The structural analysis of FTIR, Raman spectroscopy, and X-ray diffraction indicated that the molecular structure of PPy was strongly stable, and its microstructure was only slightly affected by electron beam irradiation. Within different dose ranges, the particle size of PPy remained unchanged, indicating that PPy has outstanding radiation resistance performance.
Influence of Operating Temperature on Crack Growth Characteristics and Fatigue Life Prediction of Carbon Black-Filled Hydrogenated Nitrile Butadiene Rubber
Authors: Li Runze , Lian Zisheng , Wei Wensheng
Published: December 2024

Rubber is widely used in situations involving cyclic loads, and the influence of temperature on rubber properties is particularly pronounced under cyclic loading. In this study, mechanical property tests and crack propagation tests of carbon black-filled hydrogenated nitrile butadiene rubber were conducted at four different operating temperatures. Based on the results of the crack propagation tests, the temperature-dependent characteristics of the Paris–Erdogan parameters and strain energy density were clarified. The Paris–Erdogan parameters were successfully expressed as a function of temperature. The strain energy density, on the other hand, exhibited the property of being strongly influenced by factors of strain, loading frequency, and others, while the temperature dependence was weak. On this basis, the unified fatigue crack growth kinetic model was constructed at multiple temperatures. The model results can match the experimental data well, particularly at temperatures of 60 °C and 80 °C. Finally, the fatigue life prediction model at different temperatures was constructed by combining the fatigue life test results. The results indicate a correlation between crack propagation characteristics and fatigue life predictions across different operating temperatures, with the predictions agreeing well with the measured life. The models can be used to analyze early fracture behavior or fatigue life prediction of rubber at different operating temperatures and minimize the need for extensive product testing prior to the manufacture of rubber products.
Preparation and Characterization of Melamine Aniline Formaldehyde-Organo Clay Nanocomposite Foams (MAFOCF) as a Novel Thermal Insulation Material
Authors: Gürses Ahmet , Şahin Elif
Published: December 2024

The main purpose of this study is to prepare a melamine aniline formaldehyde foam, an MAF copolymer, with lower water sensitivity and non-flammability properties obtained by the condensation reaction of melamine, aniline, and formaldehyde. In addition, the preparation of MAFF composites with organoclay reinforcement was determined as a secondary target in order to obtain better mechanical strength, heat, and sound insulation properties. For the synthesis of foams, the microwave irradiation technique, which offers advantages such as faster reactions, high yields and purities, and reduced curing times, was used together with the heating technique and the effect of organoclay content on the structural and textural properties of foams and both heat insulation and mechanical stability was investigated. Virgin melamine formaldehyde foam, MFF, melamine aniline formaldehyde foam, MAFFF, and melamine aniline formaldehyde–organoclay nanocomposite foams prepared with various organoclay contents, MAFOCFs, were characterized by HRTEM, FTIR, SEM, and XRD techniques. From spectroscopic and microscopic analyses, it was observed that organoclay flakes could be exfoliated without much change in the resin matrix with increasing clay content. In addition, it was determined that aniline formaldehyde, which is thought to enter the main polymer network as a bridge, caused textural changes in the polymeric matrix, and organoclay reinforcement also affected these changes. Although the highest compressive strength was obtained in MAFOCF5 foam with high organoclay content (0.40 MPa), it was determined that the compressive strengths in the nanocomposites were generally quite high despite their low bulk densities. In the prepared nanocomposite with 0.30% organoclay content (MAFOCF2), 0.33 MPa compressive strength and 0.051 thermal conductivity coefficient were measured. For virgin polymers and composites, bulk density, thermal conductivity, and compressive strength values were determined in the order of magnitude as MFF > MAFOCF1 > MAFOCF5 > MAFOCF6 > MAFF > MAFOCF3 > MAFOCF2 > MAFOCF4; MFF > MAFF > MAFOCF6 > MAFOCF5 > MAFOCF1 > MAFOCF4 > MAFOCF3 > MAFOCF2 and MAFOCF5 > MAFOCF4 > MAFOCF2 > MAFF > MAFOCF6 > MFF > MAFOCF1 > MAFOCF3. As a result, both compressive strength and thermal conductivity values indicate that nanocomposite foam with 0.20 wt% organoclay content can be a promising new insulation material.
New Composite Packaging Material from Edible Oil By-Product Coated with Paraffin Wax for Dry Apricot Slice Packing Under a Modified Atmosphere
Authors: Hromiš Nevena , Ostojić Sanja , Pezo Lato , Popović Senka , Šumić Zdravko , Milić Anita , Kocić-Tanackov Sunčica , Šuput Danijela
Published: December 2024

Composite biopolymer hydrogel as food packaging material, apart from being environmentally favorable, faces high standards set upon food packaging materials. The feature that favors biopolymer film application is their low gas permeability under room conditions and lower relative humidity conditions. However, most biopolymer-based materials show high moisture sensitiveness and limited water vapor permeability, which limits their application for food packaging. In this paper, a new packaging material derived from an edible oil industry byproduct (pumpkin oil cake) coated with a thin layer of paraffin wax was obtained. Compared to the film without wax coating, the new material showed reduced water sensitivity and significantly reduced water vapor transmission rate (56.98 ± 7.42 g/m2 24 h). The new material was tested for packing dry apricot slices under a modified atmosphere (100% N2). Gas composition in PuOC/wax pouches’ headspace was minimally changed during 105 days of storage. The low moisture content (6.76–10.60%) of dried apricot slices was preserved throughout the storage period (p > 0.05), as well as high rehydration power (65–75%). Changes in sensorial properties during storage were minimal. Total phenol content was minimally reduced during storage, followed by antioxidant activity (FRAP and ABTS trial). The microbial profile of dried apricot slices showed that a safe product was obtained throughout the storage. Considering the results, the functionality of new material for packing dry apricots under a modified atmosphere was proven.
Clarification of Bio-Degumming Enzymes Based on a Visual Analysis of the Hemp Roving Structure
Authors: Yu Tianyi , Li Pandeng , Shu Tong , Liu Tingting , Fu Chunhua , Yu Longjiang
Published: December 2024

Hemp fibers, recognized for their breathability, specific strength, and ultraviolet resistance, are widely utilized in textile manufacturing and composite materials. Bio-degumming is a promising alternative technology to traditional chemical degumming that can be used to produce hemp fibers due to its eco-friendly nature. However, its lower efficiency has hindered its widespread adoption. The unclear and complex structure of the gums leads to a poor understanding on the enzyme types required for bio-degumming, thereby restricting improvements in its efficiency. In this study, the morphological characteristics, polysaccharide composition, and branched structure of hemp stem, roving fibers, and refined fibers were investigated using scanning electron microscopy and laser scanning confocal microscopy in combination with immunofluorescence techniques, with a view to identify the enzymes necessary for the efficient bio-degumming of hemp. The results revealed that the gums were primarily located in the middle lamella, phloem parenchyma, and certain xylem tissues. These tissues showed chunk-like, fence-like, and plate-like shapes, respectively, and tightly wrapped around the fiber bundles. In these tissues, pectin comprised low-esterified homogalacturonan, along with rhamnogalacturonan carrying galactan and arabinan branches. Xylan exhibited acetyl, arabinose, and glucuronic acid branches, while mannan displayed acetyl and galactose branches. Partial xylan and mannan were masked by pectin, and the branching structures impeded their enzymatic removal. As a consequence, the necessary enzymes and their synergistic effects for effective hemp roving degumming were elucidated. Pectin degradation was facilitated by pectate lyase and rhamnogalacturonan-degrading enzymes. Xylan and mannan were effectively removed by endo-xylanase and endo-mannanase, a process necessitating the synergistic action of branched-chain-degrading enzymes, including the esterase, α-L-arabinofuranosidase, α-galactosidase, and α-glucuronidase. This study provided practical strategies to enhance the efficiency of hemp bio-degumming.
The Stability Evaluation of Ceria Slurry Using Polymer Dispersants with Varying Contents for Chemical Mechanical Polishing Process
Authors: Hwang Sohee , Park Jihee , Kim Woonjung
Published: December 2024

The chemical mechanical polishing/planarization (CMP) is essential for achieving the desired surface quality and planarity required for subsequent layers and processing steps. However, the aggregation of slurry particles caused by abrasive materials can lead to scratches, defects, increased surface roughness, degradation the quality and durability of the finished surface after milling processes during the CMP process. In this study, ceria slurry was prepared using polymer dispersant with zinc salt of ethylene acrylic acid (EAA) copolymer at different contents of 5, 6, and 7 wt% (denoted as D5, D6, and D7) to minimize particle aggregation commonly observed in CMP slurries. Among them, the D7 sample exhibited smaller particle sizes compared to commercial ceria slurry, which was attributed to the influence of the carboxyl groups (-COOH) of the polyacrylic acid polymer coating the ceria particles. It is believed that the polymer dispersant more effectively adsorbs onto the particle surfaces, increasing electrostatic repulsion between particles and thereby reducing particle size. Furthermore, the stability of the prepared slurry was evaluated under extreme conditions over three months at 25 °C (both open and closed conditions), 4 °C, and 60 °C. The D7 slurry remained stable with no significant changes observed. In addition, the prepared D7 ceria slurry exhibited a slightly higher removal rate (RR) and better uniformity, which can be attributed to the smaller particle sizes of the ceria nanoparticles compared to those in the commercial slurry. This suggests that the colloidal stability of the D7 ceria slurry is superior to that of the commercial ceria slurry.
Fabrication of Polytetrafluoroethylene-Reinforced Fluorocarbon Composite Coatings and Tribological Properties Under Multi-Environment Working Conditions
Authors: Xi Changqing , Zhang Bochao , Ye Xiangdong , Yan Honghua
Published: December 2024

Currently, few studies have been conducted on the use of fluorocarbon resin (FEVE) and polytetrafluoroethylene (PTFE) as adhesive substrates and lubricating and anti-corrosion fillers, respectively, for the fabrication of PTFE-reinforced fluorocarbon composite coatings. In this paper, the tribological properties of polytetrafluoroethylene-reinforced fluorocarbon composite coatings were investigated through orthogonal tests under various operating conditions. The optimal configuration for coating preparation under dry friction and aqueous lubrication was thus obtained: the optimal filler particle size, mass ratio of FEVE to PTFE, spraying pressure, and curing agent content were 50 μm, 3:4.5, 0.3 MPa, and 0.3, respectively. Under oil lubrication, the corresponding optimal values were 5 μm, 3:4.5, 0.3 MPa, and 0.3, respectively. Tribological tests revealed that the best overall performance of the FEVE/PTFE coating was obtained when the mass ratio of FEVE to PTFE was 3:4.5, and the filler particle size also significantly affected the tribological properties under different environments, including the friction coefficients of the FEVE/50 μm-PTFE coating under both dry friction and aqueous lubrication, as well as the friction coefficient of the FEVE/5 μm-PTFE coating under oil lubrication. These coefficients were 0.067, 0.062, and 0.055, representing decreases of 86%, 92%, and 56%, respectively, compared to those of the pure FEVE coating under the same working conditions. This research was conducted with the goal of expanding the application of fluorocarbon coatings in the field of tribology.
Participation of Polymer Materials in the Structure of Piezoelectric Composites
Authors: Pîrvu Cosmin Ionuț , Sover Alexandru , Abrudeanu Mărioara
Published: December 2024

This review explores the integration of polymer materials into piezoelectric composite structures, focusing on their application in sensor technologies, and wearable electronics. Piezoelectric composites combining ceramic phases like BaTiO3, KNN, or PZT with polymers such as PVDF exhibit significant potential due to their enhanced flexibility, processability, and electrical performance. The synergy between the high piezoelectric sensitivity of ceramics and the mechanical flexibility of polymers enables the development of advanced materials for biomedical devices, energy conversion, and smart infrastructure applications. This review discusses the evolution of lead-free ceramics, the challenges in improving polymer–ceramic interfaces, and innovations like 3D printing and surface functionalization, which enhance charge transfer and material durability. It also covers the effects of radiation on these materials, particularly in nuclear applications, and strategies to enhance radiation resistance. The review concludes that polymer materials play a critical role in advancing piezoelectric composite technologies by addressing environmental and functional challenges, paving the way for future innovations.
A Novel Polytetrahydrofuran-Based Shape Memory Polyurethane Enhanced by Polyglycolide-Block-Polytetrahydrofuran-Block-Polyglycolide Copolymer
Authors: Li Xin , Mao Lingchen , Li Weiqian , Wu Han , Dai Suyang , Xiao Rui , Huang Jiayi , Liu Guodong , Yang Keda , Bu Wensheng , Jiang Ni , Gan Zhihua , Ning Zhenbo
Published: December 2024

A series of polyurethanes (PU-GT) were prepared using polyglycolide-block-polytetrahydrofuran-block-polyglycolide (PGA-PTHF-PGA), polytetrahydrofuran homopolymer (PTHF), glycerol, and hexamethylene diisocyanate (HDI) by a one-pot synthesis method. The non-isothermal crystallization and subsequent heating curves showed that the PTHF component in these polyurethanes could crystallize in a temperature range of −11.5~2.6 °C during the cooling process, and the melting temperatures of PTHF crystallites were in the range of 24.0~26.9 °C. The WAXD results implied that a small content of PGA could crystallize in the membranes of PU-GT polyurethanes. And compared with PU-GT-100, which did not contain the PGA-PTHF-PGA block polymer, other PU-GT polyurethanes showed excellent mechanical properties because of the existence of the PGA component. Moreover, these polyurethanes had temperature-responsive shape memory properties due to the PTHF crystallites. The temporary shape could be fixed at −20 °C and recovered to the permanent shape at 37 °C. We conducted two kinds of conceptual experiments using PU-GT-50 polyurethane, which showed its great potential for medical applications in vascular and wound repair.
The Integration of Microwave-Synthesized Silver Colloidal Nanoparticles into Poly (Lactic Acid)-Based Textiles as Antimicrobial Agents via Pre- and Post-Electrospinning Processes
Authors: Aijaz Muhammad Omer , Alnaser Ibrahim A. , Haque Siddiqui Md Irfanul , Karim Mohammad Rezaul
Published: December 2024

This study introduces a novel method to enhance the antibacterial functionality of electrospun nanofibrous textiles by integrating silver nanoparticles (AgNPs) into poly (lactic acid) (PLA) fabrics through pre- and post-electrospinning techniques. AgNPs were incorporated into hydrophobic and modified hydrophilic PLA textiles via pre-solution blending and post-solution casting. A PEG-PPG-PEG tri-block copolymer was utilized to enhance hydrophilicity and water stability, while AgNPs served as antibacterial agents. Morphological analyses confirmed uniform, smooth, and beadless nanofibers with diameters between 435 and 823 nm. Energy-dispersive X-ray spectroscopy spectra and elemental analysis verified the successful incorporation of AgNPs, with higher Ag content in the post-electrospinning samples. Contact angle measurements showed an improved hydrophilicity of the modified PLA textiles, absorbing water droplets within 2 s. The X-ray crystallography patterns confirmed the amorphous structures of the PLA and PEG-PPG-PEG, with reduced crystallinity in the samples containing AgNPs. Thermal analysis indicated lower decomposition temperatures for the hydrophilic samples due to the plasticizing effects of PEG-PPG-PEG on PLA. Mechanical testing showed comparable tensile strengths but reduced elongation in the post-treated samples. The antibacterial efficacy was assessed against various bacterial strains, with post-electrospinning AgNP incorporation showing the most effective antibacterial properties. The results indicate that integrating electrospinning and nanofiber modification techniques expands the applications of PLA-based protective fabrics for disabled individuals.
Study on Length–Diameter Ratio of Axial–Radial Flux Hybrid Excitation Machine
Authors: Guo Mingyu , Xia Jiakuan , Wu Qimin , Gao Wenhao , Qiu Hongbo
Published: December 2024

To improve the flux regulation range of the Axial–Radial Flux Hybrid Excitation Machine (ARFHEM) and the utilization rate of permanent magnets (PMs), the effects of different length–diameter ratios (LDRs) on the ARFHEM performance are studied. Firstly, the principle of the flux regulation of the ARFHEM is introduced by means of the structure and equivalent magnetic circuit method. Then, based on the principle of the bypass effect, the analytical formulas of LDRs, the number of pole-pairs, and the flux regulation ability are derived, and then the restrictive relationship between the air-gap magnetic field, LDR, and the number of pole-pairs is revealed. On this basis, the influence of an electric LDR on motor performance is studied. By comparing and analyzing the air-gap magnetic density and no-load back electromotive force (EMF) of motors with different LDRs, the variation in the magnetic flux regulation ability of motors with different LDRs is obtained and its influence mechanism is revealed. In addition, the torque regulation ability and loss of motors with different LDRs are compared and analyzed, and the influence mechanism of the LDR on torque and loss is determined. Finally, the above analysis is verified by experiments.