bluuebunny/crossref_metadata_2025 huggingface dataset:
Virgin Camellia Seed Oil Improves Glycolipid Metabolism in the Kidney of High Fat-Fed Rats through AMPK-SREBP Pathway
Authors: Zhu Qinhe , Li Guihui , Ma Li , Chen Bolin , Zhang Dawei , Gao Jing , Deng Senwen , Chen Yongzhong
Published: November 2023

Camellia seed oil (CO) is used as edible oil in southern China because of its excellent fatty acid composition and abundant bioactive compounds. Chronic kidney disease (CKD) is one of the most common chronic degenerative diseases in China, and active compounds in vegetable oil, like virgin olive oil, have been demonstrated to be efficacious in the management of CKD. In this study, virgin CO was refined using a standard process. The refining had minimal impact on the fatty acid composition, but significantly reduced the presence of bioactive compounds like polyphenols in CO. Sprague-Dawley (SD) rats fed with high fat diet (Group G) were treated with either virgin (Group Z) or refined CO (Group R). The oral administration of CO alleviated lipid accumulation and decreased body and kidney weight gain. Furthermore, treatment with virgin CO increased the renal ATP content. The renal expression levels of AMPK and key enzymes involved in fatty acid oxidation (CPT-1 and ACOX1) and glycolysis (HK, PFK, PK and GAPDH) were up-regulated in Group Z, thereby enhancing the ATP production. Virgin CO treatment downregulated the expression level of SREBP2 and its downstream target genes, such as ACC, FAS, and HMGCR, which reduced lipid synthesis. These findings indicate that virgin CO improves glycolipid metabolism and restores energy homeostasis in the kidneys of rats fed with a high-fat diet by modulating the AMPK–SREBP-signaling pathway, suggesting the potential of active compounds in virgin CO for managing the renal failure associated with glycolipid dysmetabolism.
Changes in Plasma Carotenoid Concentrations during the AntioxObesity Weight Reduction Program among Adults with Excessive Body Weight
Authors: Hamulka Jadwiga , Sulich Agnieszka , Górnicka Magdalena , Jeruszka-Bielak Marta
Published: November 2023

Plasma carotenoid concentrations are associated with antioxidant defense which might be disturbed in people with excessive body weight (EBW). This study aimed at evaluating the effect of a 6-week weight reduction program on plasma concentration of β-carotene, lycopene, and lutein/zeaxanthin in adults with EBW. A total of 130 adults were recruited for the study; 75 completed the program. Data on food consumption were collected with a 3-day recording method and a semi-quantitative FFQ. Body height, body weight (BW), waist circumference (WC), fat mass (FM), fat-free mass (FFM), abdominal subcutaneous adipose tissue (SAT), and visceral adipose tissue (VAT) were measured. Lipid profile, β-carotene, lycopene, and lutein/zeaxanthin were analyzed in blood. The AntioxObesity program resulted in a significant reduction in BW, WC, FM, SAT, and VAT. The mean plasma concentrations of β-carotene, lycopene, and lutein/zeaxanthin increased significantly after intervention. A reduction in FM above 4 kg significantly increased the concentration of β-carotene, lutein/zeaxanthin, and total carotenoids. An increase in carotenoid levels correlated with FM reduction, as fruit and vegetable intake remained unchanged. However, this effect may vary due to gender, HDL-cholesterol, body fat content, and obesity status in the weight loss process.
Spirulina Supplementation with High-Intensity Interval Training Decreases Adipokines Levels and Cardiovascular Risk Factors in Men with Obesity
Authors: Supriya Rashmi , Delfan Maryam , Saeidi Ayoub , Samaie Seyedeh Somayeh , Al Kiyumi Maisa Hamed , Escobar Kurt A. , Laher Ismail , Heinrich Katie M. , Weiss Katja , Knechtle Beat , Zouhal Hassane
Published: November 2023

Adiposity, a state characterized by excessive accumulation of body fat, is closely linked to metabolic complications and the secretion of specific adipokines. This study explores the potential of exercise and Spirulina supplementation to mitigate these complications and modulate adipokine release associated with obesity. The primary objective of this investigation was to examine the impact of a 12-week regimen of high-intensity training combined with Spirulina supplementation on adipokine concentrations and lipid profiles in male individuals with obesity (N = 44). The participants were randomly distributed into four groups, each consisting of 11 participants: a control group (CG), a supplement group (SG), a training group (TG), and a training plus supplement group (TSG). The intervention comprised a 12-week treatment involving Spirulina supplementation (6 g capsule daily), a 12-week high-intensity interval training (HIIT) protocol with three sessions per week, or a combined approach. Following the interventions, metabolic parameters, anthropometric measurements, cardiorespiratory indices, and circulating adipokines [CRP, Sema3C, TNF-α, IL-6, MCP1, IL-8] were assessed within 48 h of the before and final training session. Statistical analyses revealed significant differences across all measures among the groups (p < 0.05). Notably, post hoc analyses indicated substantial disparities between the CG and the three interventional groups regarding body weight (p < 0.05). The combined training and supplementation approach led to noteworthy reductions in low-density lipoprotein (LDL), total cholesterol (TC), and triglyceride (TGL) levels (all p < 0.0001), coupled with an elevation in high-density lipoprotein–cholesterol (HDL-C) levels (p = 0.0001). Furthermore, adipokine levels significantly declined in the three intervention groups relative to the CG (p < 0.05). The findings from this 12-week study demonstrate that Spirulina supplementation in conjunction with high-intensity interval training reduced adipokine levels, improved body weight and BMI, and enhanced lipid profiles. This investigation underscores the potential of Spirulina supplementation and high-intensity interval training as a synergistic strategy to ameliorate obesity-related complications and enhance overall cardiometabolic well-being in obese males.
Distinct Metabolites in Osteopenia and Osteoporosis: A Systematic Review and Meta-Analysis
Authors: Wang Yuhe , Han Xu , Shi Jingru , Liao Zeqi , Zhang Yuanyue , Li Yuanyuan , Jiang Miao , Liu Meijie
Published: November 2023

Multiple studies have indicated that distinct metabolites are involved in the occurrence and development of osteopenia (ON) and osteoporosis (OP); however, these metabolites in OP and ON have not yet been classified and standardized. This systematic review and meta-analysis included 21 articles aiming to investigate the distinct metabolites in patients with ON and OP. The quality of the included articles was generally high; seventeen studies had >7 stars, and the remaining four received 6 stars. This systematic review showed that three metabolites (phosphatidylcholine (PC) (lipid metabolites), galactose (carbohydrate metabolites), and succinic acid (other metabolites)) increased, four (glycylglycine (gly-gly), cystine (amino acids), sphingomyelin (SM) (lipid metabolites) and glucose (carbohydrate metabolites)) decreased, and five (glutamine, hydroxyproline, taurine (amino acids), lysophosphatidylcholine (LPC) (lipid metabolites), and lactate (other metabolites)) had conflicting directions in OP/ON. The results of the meta-analysis show that gly-gly (MD = −0.77, 95%CI −1.43 to −0.11, p = 0.02) and cystine (MD = −5.52, 95%CI −7.35 to −3.68, p < 0.00001) decreased in the OP group compared with the healthy control group. Moreover, LPC (MD = 1.48, 95%CI 0.11 to 2.86, p = 0.03) increased in the OP group compared with the healthy control group. These results indicate that distinct metabolites were associated with ON and OP, which could be considered a predictor for OP.
Celiac Disease on the Bed-Side: Embedding Case Finding and Screening in Hospitalized Children
Authors: Pepe Angela , Mandato Claudia , Di Leo Tiziana , Boccia Giovanni , Lucaroni Giulia , Franci Gianluigi , Mauro Carolina , Di Cara Giuseppe , Valitutti Francesco
Published: November 2023

Background: Strategies for diagnosing celiac disease (CD) include case-finding and population-screening programs. Case finding consists of testing individuals at increased risk for the disease due to symptoms or associated conditions. Screening programs are widespread campaigns, which definitely perform better in terms of unveiling CD diagnoses but nowadays are still debatable. The global prevalence of CD is around 1% but it almost doubles when considering screening programs among school children. Within this framework, we aimed to estimate the prevalence of CD among hospitalized children in the Pediatric Department of a Southern Italy University Hospital in the period from January 2018 through December 2021. In addition, we attempted to explore, at the time of diagnosis, the prevalence of leading clinical alerts due to malabsorption/malnutrition such as anemia or failure to thrive or due to systemic inflammation/immune dysfunction as hypertransaminasemia and thyroid dysfunction. Methods: Data records of pediatric patients admitted as inpatients and tested by anti-transglutaminase IgA antibodies (TGA-IgA) were retrospectively analyzed. CD was diagnosed according to either 2012 or 2020 ESPGHAN guidelines, depending on the year of diagnosis. CD autoimmunity (CDA) was a wider group defined within our protocol if patients had elevated TGA-IgA on at least one occasion, regardless of anti-endomysial antibodies (EMA-IgA) and without biopsy confirmation. Results: During the observation period, 3608 pediatric patients were admitted and 1320 were screened for CD (median age 5 years, IQR 2–9 years; CD test rate: 36.6% out of all admissions). The available prevalence of newly diagnosed CD was 1.59% (21 patients diagnosed) and the available prevalence of CDA was 3.86% (51 subjects). Among CD patients, underweight/malnourished children accounted for 28.6% (6 out of 21). Conclusions: The estimated prevalence of CD diagnoses within our setting was comparable to the most recent population-screening programs. The estimated prevalence of CDA was even higher. A hospital-admission CD testing during routine blood draws might be a non-invasive, cost-effective and valuable approach to reduce discrepancy of prevalence between case-finding and population-screening programs.
Structure, Health Benefits, Mechanisms, and Gut Microbiota of Dendrobium officinale Polysaccharides: A Review
Authors: Wu Weijie , Zhao Ziqi , Zhao Zhaoer , Zhang Dandan , Zhang Qianyi , Zhang Jiayu , Fang Zhengyi , Bai Yiling , Guo Xiaohui
Published: November 2023

Dendrobium officinale polysaccharides (DOPs) are important active polysaccharides found in Dendrobium officinale, which is commonly used as a conventional food or herbal medicine and is well known in China. DOPs can influence the composition of the gut microbiota and the degradation capacity of these symbiotic bacteria, which in turn may determine the efficacy of dietary interventions. However, the necessary analysis of the relationship between DOPs and the gut microbiota is lacking. In this review, we summarize the extraction, structure, health benefits, and related mechanisms of DOPs, construct the DOPs-host axis, and propose that DOPs are potential prebiotics, mainly composed of 1,4-β-D-mannose, 1,4-β-D-glucose, and O-acetate groups, which induce an increase in the abundance of gut microbiota such as Lactobacillus, Bifidobacterium, Akkermansia, Bacteroides, and Prevotella. In addition, we found that when exposed to DOPs with different structural properties, the gut microbiota may exhibit different diversity and composition and provide health benefits, such as metabolism regulations, inflammation modulation, immunity moderation, and cancer intervention. This may contribute to facilitating the development of functional foods and health products to improve human health.
Fennel Essential Oil as a Complementary Therapy in the Management of Diabetes
Authors: Ștefănescu Ruxandra , Ősz Bianca-Eugenia , Pintea Andrada , Laczkó-Zöld Eszter , Tero-Vescan Amelia , Vari Camil-Eugen , Fulop Emoke , Blaș Iuliana , Vancea Szende
Published: November 2023

Diabetes is a serious pathology that affects a significant number of people worldwide. Its progression is rapid and leads to serious complications if glycemic control is missing. The micro and macrovascular complications of diabetes produce disabilities over time that affect the daily lives of patients. The major challenge of diabetes therapy is to reach a stable glycemic state and to delay the onset of specific complications. Aromatherapy is considered an alternative or complementary therapy, but in recent years, there has been a tendency to overuse essential oils. The present study was designed to evaluate and compare the effects produced by the topical and oral administration of fennel essential oil to diabetic rats. Eighteen compounds in fennel essential oil were identified by gas chromatography–mass spectrometry (GC-MS) analysis. The major compounds were trans-anethole (64.6%) and fenchone (24.5%). The in vivo study revealed that after a four-week treatment with fennel essential oil, the rats’ glycemic levels were significantly reduced (p ≤ 0.05). Furthermore, there were no differences between the two routes of administration. In addition, an ex vivo study underlined the potential effect of this essential oil in the prevention of cataract formation.
Dually Modified Cellulose as a Non-Viral Vector for the Delivery and Uptake of HDAC3 siRNA
Authors: Hülsmann Juliana , Lindemann Henry , Wegener Jamila , Kühne Marie , Godmann Maren , Koschella Andreas , Coldewey Sina M. , Heinze Thomas , Heinzel Thorsten
Published: November 2023

RNA interference can be applied to different target genes for treating a variety of diseases, but an appropriate delivery system is necessary to ensure the transport of intact siRNAs to the site of action. In this study, cellulose was dually modified to create a non-viral vector for HDAC3 short interfering RNA (siRNA) transfer into cells. A guanidinium group introduced positive charges into the cellulose to allow complexation of negatively charged genetic material. Furthermore, a biotin group fixed by a polyethylene glycol (PEG) spacer was attached to the polymer to allow, if required, the binding of targeting ligands. The resulting polyplexes with HDAC3 siRNA had a size below 200 nm and a positive zeta potential of up to 15 mV. For N/P ratio 2 and higher, the polymer could efficiently complex siRNA. Nanoparticles, based on this dually modified derivative, revealed a low cytotoxicity. Only minor effects on the endothelial barrier integrity and a transfection efficiency in HEK293 cells higher than Lipofectamine 2000TM were found. The uptake and release of the polyplexes were confirmed by immunofluorescence imaging. This study indicates that the modified biopolymer is an auspicious biocompatible non-viral vector with biotin as a promising moiety.
The Synthesis and Antibacterial Properties of Pillar[5]arene with Streptocide Fragments
Authors: Subakaeva Evgenia , Zelenikhin Pavel , Sokolova Evgenia , Pergat Arina , Aleksandrova Yulia , Shurpik Dmitriy , Stoikov Ivan
Published: November 2023

The growing problem of bacterial resistance to antimicrobials actualizes the development of new approaches to solve this challenge. Supramolecular chemistry tools can overcome the limited bacterial resistance and side effects of classical sulfonamides that hinder their use in therapy. Here, we synthesized a number of pillar[5]arenes functionalized with different substituents, determined their ability to self-association using DLS, and characterized antimicrobial properties against S. typhimurium, K. pneumoniae, P. aeruginosa, S. epidermidis, S. aureus via a resazurin test. Biofilm prevention concentration was calculated for an agent with established antimicrobial activity by the crystal–violet staining method. We evaluated the mutagenicity of the macrocycle using the Ames test and its ability to affect the viability of A549 and LEK cells in the MTT-test. It was shown that macrocycle functionalized with sulfonamide residues exhibited antimicrobial activity an order higher than pure streptocide and also revealed the ability to prevent biofilm formation of S. aureus and P. aeruginosa. The compound did not show mutagenic activity and exhibited low toxicity to eukaryotic cells. The obtained results allow considering modification of the macrocyclic platforms with classic antimicrobials as an opportunity to give them a “second life” and return to practice with improved properties.
Amino Acid-Based Boron Carriers in Boron Neutron Capture Therapy (BNCT)
Authors: Järvinen Juulia , Pulkkinen Herkko , Rautio Jarkko , Timonen Juri M.
Published: November 2023

Interest in the design of boronated amino acids has emerged, partly due to the utilization of boronophenylalanine (BPA), one of the two agents employed in clinical Boron Neutron Capture Therapy (BNCT). The boronated amino acids synthesized thus far for BNCT investigations can be classified into two categories based on the source of boron: boronic acids or carboranes. Amino acid-based boron carriers, employed in the context of BNCT treatment, demonstrate significant potential in the treatment of challenging tumors, such as those located in the brain. This review aims to shed light on the developmental journey and challenges encountered over the years in the field of amino acid-based boron delivery compound development. The primary focus centers on the utilization of the large amino acid transporter 1 (LAT1) as a target for boron carriers in BNCT. The development of efficient carriers remains a critical objective, addressing challenges related to tumor specificity, effective boron delivery, and rapid clearance from normal tissue and blood. LAT1 presents an intriguing and promising target for boron delivery, given its numerous characteristics that make it well suited for drug delivery into tumor tissues, particularly in the case of brain tumors.
Recent Advances in Graphene-Enabled Silicon-Based High-Speed Optoelectronic Devices—A Review
Authors: Singh Yadvendra , Subbaraman Harish
Published: November 2023

Silicon (Si) photonics has emerged as a prominent technology for meeting the escalating requirements of high-speed data transmission in optical communication systems. These systems need to be compact, energy-efficient, and capable of handling large amounts of data, driven by the advent of next-generation communication devices. Recently, there have been significant activities in exploring graphene within silicon-based components to enhance the overall performance metrics of optoelectronic subsystems. Graphene’s high mobility of charge carriers makes it appealing for the next generation of high-performance devices, especially in high-speed optoelectronics. However, due to its zero bandgap, graphene is unlikely to replace silicon entirely, but it exhibits potential as a catalyst for silicon-based devices, namely in high-speed electronics and optical modulators, where its distinctive characteristics can facilitate progress in silicon photonics and other fields. This paper aims to provide an objective review of the advances made within the realm of graphene-integrated Si photonics for high-speed light modulation and detection.
Polarization Dependent Gain Stability of Raman Amplification Single-Core Feedback Structure Based on Consistency of Long-Axis Azimuths Variation
Authors: Yu Fengzhen , Ma Yixiao , Jia Kun , Lai Xin , Xiao Qian , Jia Bo
Published: November 2023

The law of the polarization state of Raman fiber amplifier switch in single-core feedback structures is unknown. In this paper, two kinds of optical paths with single-core feedback structures are constructed, namely the Raman amplified Faraday rotating mirror single-core feedback structure (RFA-FRMOP) and the Raman amplified ordinary flat mirror single-core feedback structure (RFA-RMOP). In the process of optical signal amplification involving Raman fiber amplifiers, the polarization dependent gain (PDG) generated by Raman switches is affected by the polarization state, and RFA-FRMOP shows better stability. Surprisingly, polarization analysis of the RFA-FRMOP structure shows that both the ellipticity angle and the long-axis azimuth of the output feedback structure changed less than that of the signal entering the feedback structure. The consistency of the long-axis azimuth variation is the main characteristic of the RFA-FRMOP structure. It is found that the variation of the azimuth of the long axis of the RFA-FRMOP structure is obviously greater than that of the ellipticity. These conclusions provide a theoretical basis for the polarization dependent application of Raman fiber amplifiers in single-core feedback structures.
Genome-Wide Identification and Expression Analysis of Auxin Response Factor (ARF) Gene Family in Panax ginseng Indicates Its Possible Roles in Root Development
Authors: Yan Min , Yan Yan , Wang Ping , Wang Yingping , Piao Xiangmin , Di Peng , Yang Deok-Chun
Published: November 2023

Auxin-responsive factors (ARFs) are an important class of transcription factors and are an important component of auxin signaling. This study conducted a genome-wide analysis of the ARF gene family in ginseng and presented its findings. Fifty-three ARF genes specific to ginseng (PgARF) were discovered after studying the ginseng genome. The coding sequence (CDS) has a length of 1092–4098 base pairs and codes for a protein sequence of 363–1565 amino acids. Among them, PgARF32 has the least number of exons (2), and PgARF16 has the most exons (18). These genes were then distributed into six subgroups based on the results obtained from phylogenetic analysis. In each subgroup, the majority of the PgARF genes displayed comparable intron/exon structures. PgARF genes are unevenly distributed on 20 chromosomes. Most PgARFs have B3 DNA binding, Auxin_resp, and PB1 domains. The PgARF promoter region contains various functional domains such as plant hormones, light signals, and developmental functions. Segmental duplications contribute to the expansion of the ARF gene family in ginseng, and the genes have undergone purifying selection during evolution. Transcriptomic results showed that some PgARFs had different expression patterns in different parts of ginseng; most PgARFs were affected by exogenous hormones, and a few PgARFs responded to environmental stress. It is suggested that PgARF is involved in the development of ginseng by regulating hormone-mediated genes. PgARF14, PgARF42, and PgARF53 are all situated in the nucleus, and both PgARR14 and PgARF53 noticeably enhance the growth length of roots in Arabidopsis. Our findings offer a theoretical and practical foundation for exploring PgARFs’ role in the growth of ginseng roots.
Emphasizing the Role of Long Non-Coding RNAs (lncRNA), Circular RNA (circRNA), and Micropeptides (miPs) in Plant Biotic Stress Tolerance
Authors: Bhar Anirban , Roy Amit
Published: November 2023

Biotic stress tolerance in plants is complex as it relies solely on specific innate immune responses from different plant species combating diverse pathogens. Each component of the plant immune system is crucial to comprehend the molecular basis underlying sustainable resistance response. Among many other regulatory components, long non-coding RNAs (lncRNAs) and circular RNAs (circRNAs) have recently emerged as novel regulatory control switches in plant development and stress biology. Besides, miPs, the small peptides (100–150 amino acids long) encoded by some of the non-coding portions of the genome also turned out to be paramount regulators of plant stress. Although some studies have been performed in deciphering the role of miPs in abiotic stress tolerance, their function in regulating biotic stress tolerance is still largely elusive. Hence, the present review focuses on the roles of long non-coding RNAs (lncRNAs) and circular RNAs (circRNAs) in combating biotic stress in plants. The probable role of miPs in plant–microbe interaction is also comprehensively highlighted. This review enhances our current understanding of plant lncRNAs, circRNAs, and miPs in biotic stress tolerance and raises intriguing questions worth following up.
Removal of Algae and Algal Toxins from a Drinking Water Source Using a Two-Stage Polymeric Ultrafiltration Membrane Process
Authors: Zhang Fan , Xiong Jianglei , Zhang Cong , Wu Xue , Tian Yuming
Published: November 2023

The release of algal toxins in algae-containing water sources poses a serious threat to drinking water safety and human health. The conventional water treatment processes of water plants have a limited ability to remove algae and algal toxins, especially algal toxins with a molecular weight (MW) of less than 1000 Da. To eliminate algal pollution from a water source, a two-stage ultrafiltration (UF) process with a large polysulfone hollow fiber membrane with a MW cut-off of 200 kDa and a small aromatic polyamide roll membrane with a MW cut-off of 1 kDa were applied after a traditional sand filter in a water treatment plant. UF operation conditions, including the operating time, pressure, and membrane flux, were investigated. With an operating pressure of 0.05–0.08 MPa, the polysulfone hollow fiber membrane removed algae effectively, as the influent algal cell concentration ranged from 1–30 cells/mL but exhibited a limited removal of algal toxins. With an operating pressure of 0.3–0.4 MPa, the elimination of microcystins (MCs) reached 96.3% with the aromatic polyamide roll membrane. The operating pressure, membrane flux, and operating time were selected as the experimental factors, and the effects on the UF efficiency to remove algal toxins and biodegradable dissolved organic carbon were investigated by the response surface methodology. The model showed that the order of influence on the membrane operating efficiency was operating pressure > membrane flux > running time. The optimal UF operating conditions were an operating pressure of 0.3 MPa, a membrane flux of 17.5 L/(m2·h), and a running time of 80 min.
Mussel-Inspired Calcium Alginate/Polyacrylamide Dual Network Hydrogel: A Physical Barrier to Prevent Postoperative Re-Adhesion
Authors: Su Zekun , Xue Beibei , Xu Chang , Dong Xufeng
Published: November 2023

Intrauterine adhesions (IUA) has become one of the main causes of female infertility. How to effectively prevent postoperative re-adhesion has become a clinical challenge. In this study, a mussel-inspired dual-network hydrogel was proposed for the postoperative anti-adhesion of IUA. First, a calcium alginate/polyacrylamide (CA-PAM) hydrogel was prepared via covalent and Ca2+ cross-linking. Benefiting from abundant phenolic hydroxyl groups, polydopamine (PDA) was introduced to further enhance the adhesion ability and biocompatibility. This CA-PAM hydrogel immersed in 10 mg/mL dopamine solution possessed remarkable mechanical strength (elastic modulus > 5 kPa) and super stretchability (with a breaking elongation of 720%). At the same time, it showed excellent adhesion (more than 6 kPa). Surprisingly, the coagulation index of the hydrogel was 27.27 ± 4.91, demonstrating attractive coagulation performance in vitro and the potential for rapid hemostasis after surgery.
Synthesis, Characterization, and Proton Conductivity of Muconic Acid-Based Polyamides Bearing Sulfonated Moieties
Authors: Corona-García Carlos , Onchi Alejandro , Santiago Arlette A. , Soto Tania E. , Vásquez-García Salomón Ramiro , Pacheco-Catalán Daniella Esperanza , Vargas Joel
Published: November 2023

Most commercially available polymers are synthesized from compounds derived from petroleum, a finite resource. Because of this, there is a growing interest in the synthesis of new polymeric materials using renewable monomers. Following this concept, this work reports on the use of muconic acid as a renewable source for the development of new polyamides that can be used as proton-exchange membranes. Muconic acid was used as a comonomer in polycondensation reactions with 4,4′-(hexafluoroisopropylidene)bis(p-phenyleneoxy)dianiline, 2,5-diaminobencensulfonic acid, and 4,4′-diamino-2,2′-stilbenedisulfonic acid as comonomers in the synthesis of two new series of partially renewable aromatic–aliphatic polyamides, in which the degree of sulfonation was varied. Fourier transform infrared spectroscopy (FTIR) and nuclear magnetic resonance (1H, 13C, and 19F-NMR) techniques were used to confirm the chemical structures of the new polyamides. It was also observed that the degree of sulfonation was proportional to the molar ratio of the diamines in the feed. Subsequently, membranes were prepared by casting, and a complete characterization was conducted to determine their decomposition temperature (Td), glass transition temperature (Tg), density (ρ), and other physical properties. In addition, water uptake (Wu), ion-exchange capacity (IEC), and proton conductivity (σp) were determined for these membranes. Electrochemical impedance spectroscopy (EIS) was used to determine the conductivity of the membranes. MUFASA34 exhibited a σp value equal to 9.89 mS·cm−1, being the highest conductivity of all the membranes synthesized in this study.
Using Heating and Cooling Presses in Combination to Optimize the Consolidation Process of Polycarbonate-Based Unidirectional Thermoplastic Composite Tapes
Authors: Birtha Janos , Kobler Eva , Marschik Christian , Straka Klaus , Steinbichler Georg
Published: November 2023

The main aim of this work was to optimize the consolidation of unidirectional fiber-reinforced thermoplastic composite tapes made of polycarbonate and carbon fibers using a heating press and a cooling press in combination. Two comprehensive studies were carried out to investigate the impact of process settings and conditions on the quality of the consolidated parts. The initial screening study provided valuable insights that informed the design of the second study, in which the experimental design was expanded and various modifications, including the implementation of a frame tool, were introduced. The second study demonstrated that the modifications in combination with a high heating press temperature and elevated heating and cooling pressures successfully achieved the desired goals: the desired thickness (2 mm), improved bonding strength (23% increase), and reduced void content (down to 4.64%) in the consolidated parts.
Improved Heat Dissipation of NR/SBR-Based Tire Tread Compounds via Hybrid Fillers of Multi-Walled Carbon Nanotube and Carbon Black
Authors: Kodal Mehmet , Yazıcı Çakır Nazlı , Yıldırım Rumeysa , Karakaya Nursel , Özkoç Güralp
Published: November 2023

The development of thermally conductive rubber nanocomposites for heat management poses a formidable challenge in numerous applications, notably within the realm of tire technology. Notably, rubber materials are characterized by their inherently low thermal conductivity. Consequently, it becomes imperative to incorporate diverse conductive fillers to mitigate the propensity for heat build-up. Multi-walled carbon nanotubes (MWCNTs), as reinforcement agents within the tire tread compounds, have gained considerable attention owing to their extraordinary attributes. The attainment of high-performance rubber nanocomposites hinges significantly on the uniform distribution of MWCNT. This study presents the influence of MWCNTs on the performance of carbon black (CB)-reinforced natural rubber (NR)/styrene butadiene rubber (SBR) tire compounds prepared via high shear melt mixing. Morphological analysis showed a good distribution of MWCNTs in the NR/SBR/CB compound. The vulcanization parameters, such as the maximum and minimum torque, cross-linking density, hardness, abrasion resistance, tensile strength, and Young modulus, exhibited a progressive improvement with the addition of MWCNT. Remarkably, adding MWCNT into CB improved the heat conductivity of the NR/SBR/CB compounds, hence decreasing the heat build-up. A percolation mode was also proposed for the hybrid carbon fillers based on the data obtained.
Natural Fibrous Materials Based on Fungal Mycelium Hyphae as Porous Supports for Shape-Stable Phase-Change Composites
Authors: Sayfutdinova Adeliya R. , Cherednichenko Kirill A. , Rakitina Maria A. , Dubinich Valeria N. , Bardina Kristina A. , Rubtsova Maria I. , Petrova Daria A. , Vinokurov Vladimir A. , Voronin Denis V.
Published: November 2023

Adsorption of organic phase-change materials (PCMs) by the porous matrix of microfibrillar cellulose (MFC) is a simple and versatile way to prepare shape-stable phase-change composites, which are promising as sustainable thermoregulating additives to construction materials. However, due to MFC inherent morphology, the resulting composites have relatively low poured density that complicates their introduction in sufficient amounts, for instance, into mortar mixes. Unlike MFC, fungal mycelium has, by an order, less fibrils thickness and, thus, possesses significantly higher poured density. Herein, we studied the feasibility of fungal mycelium-based matrices as alternative biopolymeric porous supports for preparation of sustainable and shape-stable phase-change composites. Two methods were employed to prepare the porous mycelium-based supports. The first one was the solid-state fermentation, which resulted in partial biotransformation of MFCs to mycelium hyphae, while the second one was the liquid-state surface fermentation, used to cultivate the reference matrix of Trametes hirsuta hyphae. The phase-change composites were prepared by adsorption of model organic PCMs on porous biopolymer matrices. The mass ratio of support/PCM was 40/60 wt%. The composites were studied with respect to their structure, composition, poured density, latent heat storage properties, and thermal and shape stability. The employment of the partially transformed to mycelium-hyphae MFC fibers was found to be a suitable way to prepare phase-change composites with improved poured density while preserving a reasonable latent heat capacity and shape stability as compared to the MFC/PCM composites.
Oligohexamethylene Guanidine Derivative as a Means to Prevent Biological Fouling of a Polymer-Based Composite Optical Oxygen Sensor
Authors: Lisowski Maxim D. , Korobova Elizaveta V. , Naumova Alina O. , Sedishev Igor P. , Markova Alina A. , Nguyen Minh Tuan , Kuzmin Vladimir A. , Nichugovskiy Artemiy I. , Arlyapov Vyacheslav A. , Yashtulov Nikolay A. , Melnikov Pavel V.
Published: November 2023

The use of biocidal agents is a common practice for protection against biofouling in biomass-rich environments. In this paper, oligohexamethyleneguanidine (OHMG) polymer, known for its biocidal properties, was further modified with para-aminosalicylic acid (PAS) to enhance its properties against microorganisms coated with a lipid membrane. The structure of the product was confirmed by 1H NMR, 13C NMR, and FTIR spectroscopy. The values of the minimum inhibitory concentration (MIC) against Mycobacterium smegmatis ATCC 607 and Pseudomonas chlororaphis 449 were found to be 1.40 and 1.05 μg/mL, respectively. The synthesized substance was used as an additive to the polymer matrix of the composite optical oxygen sensor material. A series of samples with different contents of OHMG-PAS was prepared using a co-dissolution method implying the fabrication of a coating from a solution containing both polymers. It turned out that the mutual influence of the components significantly affects the distribution of the indicator in the matrix, surface morphology, and contact angle. The optimal polymer content turned out to be wt.3%, at which point the water contact angle reaches almost 122°, and the fouling rate decreases by almost five times, which is confirmed by both the respiratory MTT assay and confocal microscopy with staining. This opens up prospects for creating stable and biofouling-resistant sensor elements for use in air tanks or seawater.
Properties of Stereocomplex PLA for Melt Spinning
Authors: Marx Boris , Bostan Lars , Herrmann Axel S. , Boskamp Laura , Koschek Katharina
Published: November 2023

Fibers made from biopolymers are one solution for conserving both resources and the environment. However, these fibers currently have limited strengths, which limit their use for textile applications. In this paper, a biopolymer stereocomplex poly(-lactide) (scPLA) formation on a technical scale of high-molecular-weight poly(D-lactide) (PDLA) and poly(L-lactide) (PLLA) is presented. This scPLA material is the basis for further research to develop scPLA yarns in melt spinning with technical strengths for technical application. scPLA is compared with standard and commercially available semi-crystalline PLA for the production of fibers in melt spinning (msPLA) with textile strengths. Differential scanning calorimetry (DSC) gives a degree of crystallization of 59.7% for scPLA and 47.0% for msPLA. X-ray diffraction (XRD) confirms the pure stereocomplex crystal structure for scPLA and semi-crystallinity for msPLA. scPLA and msPLA are also compared regarding their processing properties (rheology) in melt spinning. While complex viscosity of scPLA is much lower compared to msPLA, both materials show similar viscoelastic behavior. Thermal gravimetric analysis (TGA) shows the influence of the molecular weight on the thermal stability, whereas essentially the crystallinity influences the biodegradability of the PLA materials.
Improving Exoskeleton Functionality: Design and Comparative Evaluation of Control Techniques for Pneumatic Artificial Muscle Actuators in Lower Limb Rehabilitation and Work Tasks
Authors: Urrea Claudio , Agramonte Rayko
Published: November 2023

The study of lower limbs has become relevant in recent years. Lower limbs have several classifications, but the most widespread categories are robots for patient rehabilitation and robots for work tasks. Two of the main pillars in the development of exoskeletons are actuators and control strategies. Pneumatic artificial muscles are similar to human muscles in their function. This work focuses on this similarity to develop control techniques for this type of actuator. The purpose of this investigation is to design, evaluate, and compare the effectiveness of three different control systems—the proportional–integrative–derivative (PID) system, the sliding mode control (SMC) system, and the fuzzy logic controller (FLC) system—in executing precise trajectory tracking using an exoskeleton and including very realistic dynamic considerations. This study aims to design and implement these controllers and assess their performance in following three distinct trajectories, thereby determining the most efficient and reliable control method for exoskeleton motion. Additionally, the analysis centers on both the response of the controllers to external perturbations and the reaction of the controllers when the time delay inherent to their dynamic is added to the mathematical model. Finally, the results are compared, revealing through the analysis of performance indexes and time response that the FLC is the controller that exhibits the best global results in the tracking of the different trajectories. This work demonstrates that, for the system in question, the action of adding a time delay in the actuator causes the FLC and PID controllers to maintain a similar response, which is obtained without the delay action, in contrast to the system with an SMC controller. However, the same does not occur when including other dynamic factors, such as disturbances external to the system.
The Damage Caused by Particle Migration to Low-Permeability Reservoirs and Its Effect on the Seepage Capacity after CO2 Flooding
Authors: Liu Yiwen , Fu Meilong , Wang Changquan , Xu Shijing , Meng Fankun , Shen Yanlai
Published: November 2023

CO2 flooding technology is an effective technical means for tertiary oil recovery in high water cut reservoirs. Using an existing well pattern to inject CO2 is an economical and feasible development method under low contemporary oil prices. Although the particle migration caused during the displacement process will block the pore throat of the rock, the injection of CO2 can effectively reduce the CO2 injection pressure, and the dissolution that occurs during the injection process improves the seepage capacity of the fluid as a whole. In this study, assessments of particle migration and plugging after CO2 flooding and evaluations of rock dissolution by CO2-aqueous solution were carried out, and the variation characteristics of the relative permeability curve before and after displacement were evaluated, further explaining the influence of CO2 flooding on reservoir seepage capacity. The results show that, in the process of CO2 injection, the injection pressure decreases under different injection rates. After CO2 flooding under oil conditions, the core permeability loss was 43.8%, and after cleaning with toluene and anhydrous ethanol, the core permeability recovery was 24.3%, indicating that the particles were bound by crude oil during the migration process and accumulated into clusters, resulting in blockages. Although there was a certain degree of blockage, the CO2-aqueous solution mainly reacted with chlorite and released Ca2+, Mg2+, and Fe2+ ions. The concentration of Ca2+ increased by 157.43%, the concentration of Mg2+ decreased by 43.33%, and the concentration of Fe2+ decreased by 50.47%, indicating that, although the generated MgCO3 and Fe2O3 blocked the pore throat of the rock, the overall dissolution effect of CO2 on CaCO3 was stronger, and the overall seepage capacity of the fluid was improved. To a certain extent, this technique can improve the water injection capacity and the effect of subsequent water flooding.
Real-Time 3D Map Building in a Mobile Robot System with Low-Bandwidth Communication
Authors: Junaedy Alfin , Masuta Hiroyuki , Sawai Kei , Motoyoshi Tatsuo , Takagi Noboru
Published: November 2023

This paper presents a new 3D map building technique using a combination of 2D SLAM and 3D objects that can be implemented on relatively low-cost hardware in real-time. Recently, 3D visualization of the real world became increasingly important. In robotics, it is not only required for intelligent control, but also necessary for operators to provide intuitive visualization. SLAM is generally applied for this purpose, as it is considered a basic ability for truly autonomous robots. However, due to the increase in the amount of data, real-time processing is becoming a challenge. Therefore, in order to address this problem, we combine 2D data and 3D objects to create a new 3D map. The combination is simple yet robust based on rotation, translation, and clustering techniques. The proposed method was applied to a mobile robot system for indoor observation. The results show that real-time performance can be achieved by the system. Furthermore, we also combine high and low-bandwidth networks to deal with network problems that usually occur in wireless communication. Thus, robust wireless communication can be established, as it ensures that the missions can be continued even if the system loses the main network.
Frequency Agile Anti-Interference Technology Based on Reinforcement Learning Using Long Short-Term Memory and Multi-Layer Historical Information Observation
Authors: Shi Weihao , Guo Shanhong , Cong Xiaoyu , Sheng Weixing , Yan Jing , Chen Jinkun
Published: November 2023

In modern electronic warfare, radar intelligence has become increasingly crucial when dealing with complex interference environments. This paper combines radar agile frequency technology with reinforcement learning to achieve adaptive frequency hopping for radar anti-jamming. Unlike traditional reinforcement learning with Markov decision processes (MDPs), the interaction between radar and jammers occurs within the partially observable Markov decision processes (POMDPs). In this context, the partial observation information available to the agent does not strictly satisfy the Markov property. This paper uses multiple layers of historical observation information to solve this problem. Historical observations can be viewed as a time series, and time-sensitive networks are employed to extract the temporal information embedded within the observations. In addition, the reward function is optimized to facilitate the faster learning of the agent in the jammer sweep environment. This simulation shows that the optimization of the agent state, network structure, and reward function can effectively help the radar to resist jamming.
Seasonal Cooling Effect of Vegetation and Albedo Applied to the LCZ Classification of Three Chinese Megacities
Authors: Luo Yifan , Yang Jinxin , Shi Qian , Xu Yong , Menenti Massimo , Wong Man Sing
Published: November 2023

The urban heat island effect poses a growing threat to human society, especially in densely populated and developed megacities. With the introduction of the Local Climate Zones (LCZ) framework, new perspectives and findings have been brought to urban heat island studies. This study investigated the cooling effect of vegetation and albedo on the surface urban heat island (SUHI) in the classification system of LCZ during different seasons, using three Chinese megacities as case study areas. Single-factor linear regression and Pearson’s correlation coefficient were applied to analyze the seasonal cooling effect of both albedo and the NDVI on the SUHI within different LCZs. The results show that (1) the variability of the SUHI is reflected in its dominance and intensity within certain LCZs in different cities and in the efficiency of cooling factors; (2) the cooling effect of vegetation is dominant in each season, and the cooling effect produced by albedo within specific seasons can be differentiated by LCZs. This study provides valuable information for the mitigation of the SUHI magnitude in specific regions and at specific times of the year.
Estimating the Surface Fuel Load of the Plant Physiognomy of the Cerrado Grassland Using Landsat 8 OLI Products
Authors: Santos Micael Moreira , Batista Antonio Carlos , Rezende Eduardo Henrique , Da Silva Allan Deyvid Pereira , Cachoeira Jader Nunes , Dos Santos Gil Rodrigues , Biondi Daniela , Giongo Marcos
Published: November 2023

Techniques and tools meant to aid fire management activities in the Cerrado, such as accurately determining the fuel load and composition spatially and temporally, are pretty scarce. The need to obtain fuel information for more efficient management in a considerably heterogeneous, biodiverse, and fire-dependent environment requires a constant search for improved remote sensing techniques for determining fuel characteristics. This study presents the following objectives: (1) to assess the use of data from Landsat 8 OLI images to estimate the fine surface fuel load of the Cerrado during the dry season by adjusting multiple linear regression equations, (2) to estimate the fuel load through random forest and k-nearest neighbor (k-NN) algorithms in comparison to regression analyses, and (3) to evaluate the importance of predictor variables from satellite images. Therefore, 64 sampling units were collected, and the pixel values associated with the field plots were extracted in a 3 × 3-pixel window surrounding the reference pixel. For multiple linear regression analyses, the R2 values ranged from 0.63 to 0.78, while the R2 values of the models fitted using the random forest algorithm ranged from 0.52 to 0.83 and the R2 values of those fitted using the k-NN algorithm ranged from 0.30 to 0.68. The estimates made through multiple linear regression analyses showed better results for the equations adjusted for the beginning of the dry season (May and June). Adopting the random forest algorithm resulted in improvements in the statistical metrics of evaluation of the fuel load estimates for the Cerrado grassland relative to multiple linear regression analyses. The variable fraction-soil (FS) exerted the most significant effect on surface fuel load estimates, followed by the vegetation indices NDII, GVMI, DER56, NBR, and MSI, all of which use near-infrared and short-wave infrared channels in their calculations.