bluuebunny/crossref_metadata_2025 huggingface dataset:
Faba Bean: An Untapped Source of Quality Plant Proteins and Bioactives
Authors: Martineau-Côté Delphine , Achouri Allaoua , Karboune Salwa , L’Hocine Lamia
Published: April 2022

Faba beans are emerging as sustainable quality plant protein sources, with the potential to help meet the growing global demand for more nutritious and healthy foods. The faba bean, in addition to its high protein content and well-balanced amino acid profile, contains bioactive constituents with health-enhancing properties, including bioactive peptides, phenolic compounds, GABA, and L-DOPA. Faba bean peptides released after gastrointestinal digestion have shown antioxidant, antidiabetic, antihypertensive, cholesterol-lowering, and anti-inflammatory effects, indicating a strong potential for this legume crop to be used as a functional food to help face the increasing incidences of non-communicable diseases. This paper provides a comprehensive review of the current body of knowledge on the nutritional and biofunctional qualities of faba beans, with a particular focus on protein-derived bioactive peptides and how they are affected by food processing. It further covers the adverse health effects of faba beans associated with the presence of anti-nutrients and potential allergens, and it outlines research gaps and needs.
Obesity Rodent Models Applied to Research with Food Products and Natural Compounds
Authors: Martins Tânia , Ferreira Tiago , Nascimento-Gonçalves Elisabete , Castro-Ribeiro Catarina , Lemos Sílvia , Rosa Eduardo , Antunes Luís Miguel , Oliveira Paula Alexandra
Published: April 2022

Obesity is a disease whose incidence has increased over the last few decades. Despite being a multifactorial disease, obesity results essentially from excessive intake of high-calorie foods associated with low physical activity. The demand for a pharmacological therapy using natural compounds as an alternative to synthetic drugs has increased. Natural compounds may have few adverse effects and high economic impact, as most of them can be extracted from underexploited plant species and food by-products. To test the potential anti-obesogenic effects of new natural substances, the use of preclinical animal models of obesity has been an important tool, among which rat and mouse models are the most used. Some animal models are monogenic, such as the db/db mice, ob/ob mice, Zucker fatty rat and Otsuka Long-Evans Tokushima fatty rat. There are also available chemical models using the neurotoxin monosodium glutamate that induces lesions in the ventromedial hypothalamus nucleus, resulting in the development of obesity. However, the most widely used are the obesity models induced by high-fat diets. The aim of this review was to compile detail studies on the anti-obesity effects of natural compounds or their derivatives on rodent models of obesity as well as a critical analysis of the data.
Increased Indoleamine 2,3-Dioxygenase 1 (IDO-1) Activity and Inflammatory Responses during Chikungunya Virus Infection
Authors: Alves de Souza Thiara , Fernandes-Santos Caroline , Araújo da Paixão de Oliveira Jéssica , Tomé Larissa , Fiestas-Solórzano Victor , Nunes Priscila , Guimaraes Gabriel , Sánchez-Arcila Juan , Paiva Iury , de Souza Luís , Damasco Paulo , da Silva Frutuoso Válber , Heringer Manoela , de Oliveira-Pinto Luzia , Pinheiro Roberta , dos Santos Flavia , Leal de Azeredo Elzinandes
Published: April 2022

Chikungunya virus (CHIKV) infection causes intense cytokine/chemokine inflammatory responses and debilitating joint pain. Indoleamine2,3–dioxygenase 1 (IDO-1) is an enzyme that initiates the tryptophan degradation that is important in initial host innate immune defense against infectious pathogens. Besides that, IDO-1 activation acts as a regulatory mechanism to prevent overactive host immune responses. In this study, we evaluated IDO-1 activity and cytokine/chemokine patterns in CHIKV patients. Higher IDO-1 (Kyn/Trp ratio) activation was observed during the early acute phase of CHIKV infection and declined in the chronic phase. Importantly, increased concentrations of Tumor Necrosis Factor-α (TNF-α), Interleukin-6 (IL-6), Interferon γ (IFN-γ), C-C motif chemokine ligand 2/Monocyte Chemoattractant Protein-1 (CCL2/MCP-1) and C-X-C motif chemokine ligand 10/Interferon Protein-10 (CXCL10/IP-10) were found in the acute phase of infection, while C-C motif chemokine ligand 4/Macrophage Inflammatory Protein 1 β (CCL4/MIP-1β) was found at increased concentrations in the chronic phase. Likewise, CHIKV patients with arthritis had significantly higher concentrations of CCL4/MIP-1β compared to patients without arthritis. Taken together, these data demonstrated increased IDO-1 activity, possibly exerting both antiviral effects and regulating exacerbated inflammatory responses. CCL4/MIP-1β may have an important role in the persistent inflammation and arthritic symptoms following chikungunya infection.
Oral Microbiota during Childhood and Its Role in Chemotherapy-Induced Oral Mucositis in Children with Cancer
Authors: Triarico Silvia , Agresti Pierpaolo , Rinninella Emanuele , Mele Maria Cristina , Romano Alberto , Attinà Giorgio , Maurizi Palma , Mastrangelo Stefano , Ruggiero Antonio
Published: April 2022

The human oral cavity harbors the second most abundant microbiota after the gastrointestinal tract, with over 700 species currently identified in the oral microflora. The oral microbiota develops from intrauterine life and after birth is continuously shaped by several influencing factors. The perturbation of the diversity and proportions of species within the oral microbiota leads to dysbiosis and associated increased risk of local and systemic diseases. In children who receive chemotherapy for cancer, oral mucositis is a common and painful side effect that decreases quality of life (QoL) and treatment adherence. The oral microbiota undergoes a substantial dysbiosis as an effect of cancer and its treatment, characterized by lower richness and less diversity. Furthermore, this dysbiosis seems to promote pro-inflammatory cytokine release and pro-apoptotic mediators, enhancing the oral tissue damage. Further studies on the role of the oral microbiota in the pathogenesis of oral mucositis should be performed among children with cancer who receive chemotherapy, to find preventive and protective factors against the pathogenesis of oral mucositis.
Design, Synthesis, and Molecular Docking Studies of Curcumin Hybrid Conjugates as Potential Therapeutics for Breast Cancer
Authors: Panda Siva S. , Tran Queen L. , Rajpurohit Pragya , Pillai Girinath G. , Thomas Sean J. , Bridges Allison E. , Capito Jason E. , Thangaraju Muthusamy , Lokeshwar Bal L.
Published: April 2022

Curcumin (CUR) has received great attention over the past two decades due to its anticancer, anti-inflammatory, and antioxidant properties. Similarly, Dichloroacetate (DCA), an pyruvate dehydrogenase kinase 1 (PKD1) inhibitor, has gained huge attention as a potential anticancer drug. However, the clinical utility of these two agents is very limited because of the poor bioavailability and unsolicited side effects, respectively. We have synthesized fusion conjugates of CUR and DCA with an amino acids linker to overcome these limitations by utilizing the molecular hybridization approach. The molecular docking studies showed the potential targets of Curcumin-Modified Conjugates (CMCs) in breast cancer cells. We synthesized six hybrid conjugates named CMC1-6. These six CMC conjugates do not show any significant toxicity in a human normal immortalized mammary epithelial cell line (MCF10A) in vitro and C57BL/6 mice in vivo. However, treatment with CMC1 and CMC2 significantly reduced the growth and clonogenic survival by colony-formation assays in several human breast cancer cells (BC). Treatment by oral gavage of a transgenic mouse BC and metastatic BC tumor-bearing mice with CMC2 significantly reduced tumor growth and metastasis. Overall, our study provides strong evidence that CUR and DCA conjugates have a significant anticancer properties at a sub-micromolar concentration and overcome the clinical limitation of using CUR and DCA as potential anticancer drugs.
Synthesis, Characterization and Biological Activities of New Schiff Base Compound and Its Lanthanide Complexes
Authors: Abu-Yamin Abdel-Aziz , Abduh Maisa Siddiq , Saghir Sultan Ayesh Mohammed , Al-Gabri Naif
Published: April 2022

The thermal condensation of 3-(2-Furyl)acrolein with 2-Amino-6-ethoxybenzothiazole generated a new Schiff base, (1E,2E)-N-(6-ethoxybenzo[d]thiazol-2-yl)-3-(furan-2-yl)prop-2-en-1-imine (L), with general formula of C16H14N2O2S. Also, a series of lanthanide complexes of gadolinium, samarium, and neodymium (La–Lc) were synthesized utilizing acetonitrile as the solvent and triethylamine as a buffer and catalyst. Based on elemental analysis, mass spectroscopy, and FTIR analysis, all of the Bis-(1E,2E)-N-(6-ethoxybenzo[d]thiazol-2-yl)-3-(furan-2-yl)prop-2-en-1-iminetri-nitratolanthanide(III) complexes with the general formula [LnL2(NO3)3]·H2O are solids with a 2:1 molar ratio (ligand: metal). Based on conductivity estimates, they are nonelectrolytes and monoatomic paramagnetic according to the magnetic moment measurements, and one mole of lattice water was found after thermal gravimetric measurements and FTIR analysis. Therefore, the lanthanide complexes show a ten-coordination structure with a deformed bicapped square antiprismatic. The Schiff base and its complexes were screened for their antimicrobial, antifungal, antioxidant, and antitumor properties. Their antimicrobial and antifungal activities were strong, and they also produced good antioxidant and antitumor effects.
Significance of Polymers with “Allyl” Functionality in Biomedicine: An Emerging Class of Functional Polymers
Authors: Rahman Mijanur , Ali Aliaa , Sjöholm Erica , Soindinsalo Sebastian , Wilén Carl-Eric , Bansal Kuldeep Kumar , Rosenholm Jessica M.
Published: April 2022

In recent years, polymer-based advanced drug delivery and tissue engineering have grown and expanded steadily. At present, most of the polymeric research has focused on improving existing polymers or developing new biomaterials with tunable properties. Polymers with free functional groups offer the diverse characteristics needed for optimal tissue regeneration and controlled drug delivery. Allyl-terminated polymers, characterized by the presence of a double bond, are a unique class of polymers. These polymers allow the insertion of a broad diversity of architectures and functionalities via different chemical reactions. In this review article, we shed light on various synthesis methodologies utilized for generating allyl-terminated polymers, macromonomers, and polymer precursors, as well as their post-synthesis modifications. In addition, the biomedical applications of these polymers reported in the literature, such as targeted and controlled drug delivery, improvement i aqueous solubility and stability of drugs, tissue engineering, and antimicrobial coatings, are summarized.
Mucoadhesive PLGA Nanospheres and Nanocapsules for Lactoferrin Controlled Ocular Delivery
Authors: Varela-Fernández Rubén , García-Otero Xurxo , Díaz-Tomé Victoria , Regueiro Uxía , López-López Maite , González-Barcia Miguel , Isabel Lema María , Otero-Espinar Francisco Javier
Published: April 2022

Background: the present work describes the preparation, characterization and optimization of eight types of PLGA-based nanosystems (nanospheres and nanocapsules) as innovative mucoadhesive drug delivery systems of lactoferrin, in order to achieve a preclinical consistent base as an alternative pharmacological treatment to different ocular syndromes and diseases. Methods: All different nanoparticles were prepared via two modified nanoprecipitation techniques, using a three-component mixture of drug/polymer/surfactant (Lf/PLGA/Poloxamer), as a way to overcome the inherent limitations of conventional PLGA NPs. These modified polymeric nanocarriers, intended for topical ophthalmic administration, were subjected to in vitro characterization, surface modification and in vitro and in vivo assessments. Results: An appropriate size range, uniform size distribution and negative ζ potential values were obtained for all types of formulations. Lactoferrin could be effectively included into all types of nanoparticles with appropriate encapsulation efficiency and loading capacity values. A greater, extended, and controlled delivery of Lf from the polymeric matrix was observed through the in vitro release studies. No instability or cytotoxicity was proved for all the formulations by means of organotypic models. Additionally, mucoadhesive in vitro and in vivo experiments show a significant increase in the residence time of the nanoparticles in the eye surface. Conclusions: all types of prepared PLGA nanoparticles might be a potential alternative for the topical ophthalmic administration of lactoferrin.
Current and Future Treatments for Diabetic Retinopathy
Authors: Behar-Cohen Francine , Loewenstein Anat
Published: April 2022

The pathogenesis of diabetic retinopathy in humans remains imperfectly understood; in particular, the kinetics of the various pathogenic events in the very early stages of retinal damage are difficult to recognize [...]
Dynamical Collective Excitations and Entanglement of Two Strongly Correlated Rydberg Superatoms
Authors: Yan Dong , Bai Wenjie , Bai Jiannan , Chen Li , Han Haiyan , Wu Jinhui
Published: April 2022

Based on the dipole blockade effect and with the aid of the superatom (SA) model, we propose a scheme to investigate the correlated evolution of two Rydberg sub-superatoms (SSAs), formed by two spatially separated atomic Rydberg sub-ensembles but in the same blockade region. Starting from the pure separable states, we investigate the in-phase or anti-phase correlated dynamics and explore how two Rydberg SSAs entangle with each other mediated by a single Rydberg excitation. Starting from the entangled states, we discuss the robustness of the system against decoherence induced by the dephasing rate. Our results show that both the correlated evolution of two Rydberg SSAs and their collective-state entanglement are usually sensitive to the number of each Rydberg SSA. This allows us to coherently manipulate the Rydberg ensemble over long distances from the single-quantum level to the mesoscopic level by changing the number of atoms. Furthermore, the method for dividing an SA into two SSAs and obtaining their spin operators without any approximation can be readily generalized to the case of many SSAs. It may have potential promising applications in quantum information processing and provide an attractive platform to study the quantum-classical correspondence, many-body physics and so on.
Systematic Analysis of the Molecular Mechanisms of Cold and Hot Properties of Herbal Medicines
Authors: Park Sang-Min , Baek Su-Jin , Ban Hyo-Jeong , Jin Hee-Jeong , Cha Seongwon
Published: April 2022

Effective treatments for patients experiencing temperature-related symptoms are limited. The hot and cold effects of traditional herbal medicines have been utilized to treat and manage these symptoms, but their molecular mechanisms are not fully understood. Previous studies with arbitrarily selected herbs and ingredients may have produced biased results. Here, we aim to systematically elucidate the molecular mechanisms of the hot and cold properties of herbal medicines through an unbiased large-scale investigation of herbal ingredients, their target genes, and the transcriptome signatures induced by them. Using data regarding 243 herbs retrieved from two herbal medicine databases, we statistically identify (R)-Linalool, (-)-alpha-pinene, peruviol, (L)-alpha-terpineol, and cymol as five new hot-specific ingredients that share a common target, a norepinephrine transporter. However, no significant ingredients are cold-specific. We also statistically identify 14 hot- and 8 cold-specific new target genes. Pathway enrichment analysis of hot-specific target genes reveals the associated pathways including neurotransmitter reuptake, cold-induced thermogenesis, blood pressure regulation, adrenergic receptor signaling, and cation symporter activity. Cold-specific target genes are associated with the steroid pathway. Transcriptome analysis also shows that hot herbs are more strongly associated with coagulation and synaptic transmission than cold herbs. Our results, obtained from novel connections between herbal ingredients, target genes, and pathways, may contribute to the development of pharmacological treatment strategies for temperature-related pain using medicinal plants.
Comparative Study of the Antioxidant Constituents, Activities and the GC-MS Quantification and Identification of Fatty Acids of Four Selected Helichrysum Species
Authors: Akinyede Kolajo Adedamola , Hughes Gail Denise , Ekpo Okobi Eko , Oguntibeju Oluwafemi Omoniyi
Published: April 2022

Helichrysum Mill. (Asteraceae) is a plant genus comprising distinctively of aromatic plants of about 500–600 species. Since most of these plants have not been previously studied, extensive profiling helps to validate their folkloric uses and determine their potential value as sources of plant-derived drug candidates. This study, therefore, aims to investigate the antioxidant activity (DPPH, NO, FRAP); total antioxidant capacity, total phenolic, total flavonoid, and fatty acid compositions of the aqueous acetone extracts from four Helichrysum plants namely, Helichrysum pandurifolium, Helichrysum foetidum, Helichrysum petiolare, and Helichrysum cymocum. The results obtained showed that the H. cymocum extract had the best DPPH radical scavenging activity (IC50 = 11.85 ± 3.20 µg/mL) and H. petiolare extract had the best nitric oxide scavenging activity (IC50 = 20.81 ± 3.73 µg/mL), while H. pandurifolium Schrank extract (0.636 ± 0.005 µg/mL) demonstrated the best ferrous reducing power, all of which are comparable with results from ascorbic acid used as the standard. The IC50 values of the radical scavenging activity ranged from 11.85–41.13 µg/mL (DPPH), 20.81–36.19 µg/mL (NO), and 0.505–0.636 µg/mL (FRAP), for all the plants studied. The H. petiolare has the highest total antioxidant capacity (48.50 ± 1.55 mg/g), highest total phenolic content (54.69 ± 0.23 mg/g), and highest total flavonoid content (56.19 ± 1.01 mg/g) compared with other species. The fatty acid methyl esters were analysed using gas chromatography-mass spectrometry (GC-MS). The results obtained showed variations in the fatty acid composition of the plant extracts, with H. petiolare having the highest saturated fatty acid (SFA) content (7184 µg/g) and polyunsaturated fatty acid (PUFA) content (7005.5 µg/g). In addition, H. foetidum had the highest monounsaturated fatty acid (MUFA) content (1150.3 µg/g), while H. cymocum had the highest PUFA:SFA ratio of 1.202. In conclusion, the findings from this study revealed that H. pandurifolium Schrank, H. foetidum, H. petiolare, and H. cymocum are repositories of natural bioactive compounds with potential health-promoting benefits that need to be investigated, for both their antioxidant activity in a number of disease conditions and for further exploration in drug discovery and development projects.
Volatile and Non-Volatile Allelopathic Characteristics in Thermally Processed Needles of Two Conifers
Authors: Gil Chan Saem , Hong Daeun , Duan Shucheng , Eom Seok Hyun
Published: April 2022

With allelopathic composts, potential merits for preventing initial weed infestations have been observed in crop transplantation. However, previous studies have rarely investigated whether high temperatures, generated during composting, decrease allelopathic ability. This study evaluated the thermal allelopathic effect of two coniferous plants (Pinus densiflora and P. koraiensis) on Brassica napus germination and seedling growth using their characterized allelochemical destinations. The 90 °C dry treatment of P. densiflora extract exhibited stronger inhibitory effect on germination than its 30 °C dry treatment. In a range from 0.25 to 1 mg mL−1, the germination rate was decreased to 38.1 and 64.3% of control with P. densiflora extract dried at 90 and 30 °C, respectively. However, P. koraiensis showed potent inhibition of the germination process with no statistical difference in inhibitory effects regardless of the dry temperature. Regarding B. napus seedling root growth, the allelopathic effects of aqueous extracts of both conifers were not reduced with the 90 °C treatment, but it was lost in seedling shoot growth. GC-MS/MS confirmed that high temperature treatment drastically decreased volatile contents to 53.2% in P. densiflora, resulting in reduced allelopathic abilities. However, a relatively lower decrease to 83.1% in volatiles of P. koraiensis accounts for less loss of the root-specific inhibitory effect on B. napus seedlings even after 90 °C treatment. Foliar tissues of both conifers with species-specific thermal resistance have potentially valuable functions regarding allelopathic use in horticultural compost processing ingredients, demonstrating their weed control ability during the early cultivation season where crops are transplanted in the facilitated area.
Soaking Maize Seeds in Zeatin-Type Cytokinin Biostimulators Improves Salt Tolerance by Enhancing the Antioxidant System and Photosynthetic Efficiency
Authors: Azzam Clara R. , Zaki Safi-naz S. , Bamagoos Atif A. , Rady Mostafa M. , Alharby Hesham F.
Published: April 2022

There is an urgent need for innovative strategies to raise the performance of environmentally stressed plants. The seeds of single-cross yellow Zea mays (L.) hybrid Giza-168 were soaked in Cis-(c-Z-Ck) or trans-zeatin-type cytokinin (t-Z-Ck) solutions at a concentration of 50 or 40 µM, respectively. Salinity stress was imposed at 0, 75 or 150 mM NaCl in the Hoagland nutrient solution (full strength) used for irrigation. The total carotenoids content was negatively affected by only 150 mM NaCl, while both 75 and 150 mM NaCl negatively affected the growth and yield components, relative water content, membrane stability index, photochemical activity, gas exchange, K+ and chlorophyll contents, K+/Na+ ratio, and photosynthetic efficiency. However, all of these traits were significantly improved by c-Z-Ck pretreatment and further enhanced by t-Z-Ck pretreatment compared with the corresponding controls. Furthermore, the contents of proline, soluble sugars, ascorbate, and glutathione, as well as enzymatic antioxidant activities, were significantly elevated by both salt stress concentrations and increased more by both biostimulators compared to the control. Compared to c-Z-Ck, t-Z-Ck was superior in mitigating the harmful effects of the high H2O2 levels caused by salt stress on the levels of malondialdehyde and ion leakage compared to the control. Under normal or stress conditions, t-Z-Ck pretreatment was better than c-Z-Ck pretreatment, while both positively affected maize hormonal contents. As a result, t-Z-Ck is recommended to enhance the growth and productivity of maize plants by suppressing the effects of oxidative stress caused by saline water irrigation.
Effect of Mineral Nutrition and Salt Spray on Cucumber Downy Mildew (Pseudoperonospora cubensis)
Authors: Barnea Dor , Yermiyahu Uri , Rav-David Dalia , Elad Yigal
Published: April 2022

It was previously shown that spraying with CaCl2, MgCl2, KCl, and K2SO4 and high N and Mg concentrations in the irrigation water of potted cucumber plants reduced powdery mildew, while medium P and high K concentrations increased powdery mildew. In the present work, we tested the effect of irrigation with N, P, K, Ca, and Mg and spraying with salts on downy mildew (Pseudoperonospora cubensis) of cucumber (CDM). In potted plants, an increase in N concentration in the irrigation water resulted in a major increase in CDM severity, while an increase in K or Ca concentrations resulted in a gradual increase in CDM severity. An increase in P and Mg concentrations in the irrigation water resulted in a major CDM decrease. Spraying with Ca, Mg, and K salts with Cl and SO4 anions resulted in CDM suppression in most cases, and a negative correlation was obtained between the salt and anion molar concentrations and the CDM severity. Using NaCl sprays, both Na and Cl concentrations were negatively related to the CDM severity. MgCl2 (0.1 M Cl), K2SO4 (0.1 M SO4), MgCl2 + K2SO4, and monopotassium phosphate (MKP, 1%) sprayed under commercial-like (CL) conditions significantly reduced CDM by 36.6% to 62.6% in one disease cycle, while, in a second cycle, CDM was significantly reduced only by K2SO4 and MKP. In conclusion, fertigation with P and Mg, and salt spraying decreased CDM, while only spraying under CL resulted in CDM suppression.
Improvement in Thermochromic Offset Print UV Stability by Applying PCL Nanocomposite Coatings
Authors: Vukoje Marina , Kulčar Rahela , Itrić Ivanda Katarina , Bota Josip , Cigula Tomislav
Published: April 2022

Thermochromic (TC) printing inks change their colouration as a response to a change in temperature. This ability renders them attractive for various applications such as smart packaging, security printing, and marketing, but their application is limited due to their low UV stability, i.e., loss of their thermochromic effect when exposed to UV radiation. In order to improve the UV stability of TC prints, one offset TC printing ink was printed and coated with nanomodified polycaprolactone (PCL) coating. The coating was prepared with the incorporation of 1%, 2%, and 3% mass ratios of ZnO and TiO2 nanoparticles in the PCL matrix. The prepared nanocomposite coatings were applied onto the TC print and exposed to UV radiation; afterwards, they were characterized by the colour properties of prints, SEM microscopy, FTIR, and fluorescence spectroscopy. SEM microscopy, FTIR, and fluorescence spectroscopy showed higher rates of polymer degradation, and the results of colour stability indicated that 3% TiO2 in PCL matrix gave the best UV stability and protection of TC prints.
Cement-Based Repair Materials and the Interface with Concrete Substrates: Characterization, Evaluation and Improvement
Authors: Song Xuemin , Song Xiongfei , Liu Hao , Huang Haoliang , Anvarovna Kasimova Guzal , Ugli Nurmirzayev Azizbek Davlatali , Huang Yi , Hu Jie , Wei Jiangxiong , Yu Qijun
Published: April 2022

Surface damages usually occur in concrete structures. In order to restore the functions and prolong the service life of concrete structures, their surface damages should be repaired in time. This paper reviews the main requirements for repair materials for concrete structures and the most used inorganic repair materials, such as cement-based materials, alkali-activated materials and polymer modified inorganic repair materials. Moreover, techniques to characterize and even improve the interfaces between these repair materials and concrete substrate are summarized. Cement-based material has the advantages of good mechanical properties and consistency with concrete substrate while having the problems of high shrinkage and low flexibility. Polymer modified materials were found as having lower shrinkage and higher flexural strength. Increasing the roughness or humidity of the surface, adding fibers and applying interfacial agents can improve the bond strength between cement-based repair materials and concrete substrates. All of these repair materials and techniques can help to build a good interfacial bonding, and mechanisms of how they improve the interface are discussed in this article. These are of great importance in guaranteeing the effectiveness of the repair of the concrete surface and to guide the research and development of new repair materials.
A New Kinetic Modeling Approach for Predicting the Lifetime of ATH-Filled Silane Cross-Linked Polyethylene in a Nuclear Environment
Authors: Hettal Sarah , Roland Sébastien , Sipila Konsta , Joki Harri , Colin Xavier
Published: April 2022

This study focuses on the degradation of a silane cross-linked polyethylene (Si-XLPE) matrix filled with three different contents of aluminum tri-hydrate (ATH): 0, 25, and 50 phr. These three materials were subjected to radiochemical ageing at three different dose rates (8.5, 77.8, and 400 Gy·h−1) in air at low temperatures close to ambient (47, 47, and 21 °C, respectively). Changes due to radio-thermal ageing were investigated according to both a multi-scale and a multi-technique approach. In particular, the changes in the chemical composition, the macromolecular network structure, and the crystallinity of the Si-XLPE matrix were monitored by FTIR spectroscopy, swelling measurements in xylene, differential scanning calorimetry, and density measurements. A more pronounced degradation of the Si-XLPE matrix located in the immediate vicinity of the ATH fillers was clearly highlighted by the swelling measurements. A very fast radiolytic decomposition of the covalent bonds initially formed at the ATH/Si-XLPE interface was proposed to explain the higher concentration of chain scissions. If, as expected, the changes in the elastic properties of the three materials under study are mainly driven by the crystallinity of the Si-XLPE matrix, in contrast, the changes in their fracture properties are also significantly impacted by the degradation of the interfacial region. As an example, the lifetime was found to be approximately halved for the two composite materials compared to the unfilled Si-XLPE matrix under the harshest ageing conditions (i.e., under 400 Gy·h−1 at 21 °C). The radio-thermal oxidation kinetic model previously developed for the unfilled Si-XLPE matrix was extended to the two composite materials by taking into account both the diluting effect of the ATH fillers (i.e., the ATH content) and the interfacial degradation.
Thermoset/Thermoplastic Interphases: The Role of Initiator Concentration in Polymer Interdiffusion
Authors: Erartsın Ozan , Zanjani Jamal Sayyed Monfared , Baran Ismet
Published: April 2022

In the co-bonding of thermoset and thermoplastic polymers, the interdiffusion of the polymers results in the formation of an interphase between them. Understanding the factors influencing the interdiffusion and the resulting interphase is crucial in order to optimize the mechanical performance of the bond. Herein, for the first time, the effect of the initiator concentration of the thermoset resin-initiator mixture on the interphase thickness of co-bonded thermoset-thermoplastic polymers is investigated. The dependence of the gelation time on the initiator concentration is determined by rheometer measurements. Differential scanning calorimetry measurements are carried out to determine the speed of cure. To co-bond the polymers, pieces of already-manufactured thermoplastic plates are embedded in a resin-initiator mixture. The interphase thickness of the co-bonded polymers is measured with an optical microscope. The results of this study show that the gelation time decreases as the initiator concentration increases. This decrease leads to a significant reduction in both interphase thickness and diffusivity. For instance, increasing the initiator/resin weight ratio from 1% to 3% reduces the gelation time by 74% and the interphase thickness by 63%.
A Novel Porous PDMS-AgNWs-PDMS (PAP)-Sponge-Based Capacitive Pressure Sensor
Authors: Tan Xueqiang , Zheng Jimin
Published: April 2022

The development of capacitive pressure sensors with low cost, high sensitivity and facile fabrication techniques is desirable for flexible electronics and wearable devices. In this project, a highly sensitive and flexible capacitive pressure sensor was fabricated by sandwiching a porous PAP sponge dielectric layer between two copper electrodes. The porous PAP sponge dielectric layer was fabricated by introducing highly conductive silver nanowires (AgNWs) into the PDMS sponge with 100% sucrose as a template and with a layer of polydimethylsiloxane (PDMS) film coating the surface. The sensitivity of the PAP sponge capacitive pressure sensor was optimized by increasing the load amount of AgNWs. Experimental results demonstrated that when the load amount of AgNWs increased to 150 mg in the PAP sponge, the sensitivity of the sensor was the highest in the low-pressure range of 0–1 kPa, reaching 0.62 kPa−1. At this point, the tensile strength and elongation of sponge were 1.425 MPa and 156.38%, respectively. In addition, the specific surface area of PAP sponge reached 2.0 cm2/g in the range of 0–10 nm pore size, and showed excellent waterproof performance with high elasticity, low hysteresis, light weight, and low density. Furthermore, as an application demonstration, ~110 LED lights were shown to light up when pressed onto the optimized sensor. Hence, this novel porous PAP-sponge-based capacitive pressure sensor has a wide range of potential applications in the field of wearable electronics.
The Degassing Processes for Oil Media in Acoustic Fields and Their Applications
Authors: Karimov Alexander , Bogdanov Vladislav , Valiullin Rim , Sharafutdinov Ramil , Ramazanov Ayrat
Published: April 2022

Numerous experiments on the effect of acoustic fields on oil media have shown the changing nature of oil physicochemical properties. In the present paper, we present a concept of internal airlift for oil medium with dissolved gas which could be propelled by external acoustic field. The mechanism determining gas bubble size as a function of pressure change is discussed. Model of interaction for the growing bubbles with acoustic fields is presented. Relationships specifying the characteristics of both the required acoustic field and oil medium are derived. The use of these relations makes it possible to define the available range of parameters for the system under consideration where one can obtain the expected effect on oil medium. It is demonstrated how the change in pressure and oil saturation (namely, the density of oil particles in the entire flow) of the medium is associated with temperature fields in the system. In particular, it is shown that the maximum deviation between the temperature change in oil and gas and gas–liquid media reaches a significant value, namely 10−2 K for a gas–liquid medium, while this difference is −0.1 K in an oil-and-gas medium. Using this approach, thermograms of oil producing wells have been analysed at a qualitative level.
Chitosan- and Alginate-Based Hydrogels for the Adsorption of Anionic and Cationic Dyes from Water
Authors: ALSamman Mohammad T. , Sánchez Julio
Published: April 2022

Novel hydrogel systems based on polyacrylamide/chitosan (PAAM/chitosan) or polyacrylic acid/alginate (PAA/alginate) were prepared, characterized, and applied to reduce the concentrations of dyes in water. These hydrogels were synthetized via a semi-interpenetrating polymer network (semi-IPN) and then characterized by Fourier transformed infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA), and their swelling capacities in water were measured. In the adsorption experiments, methylene blue (MB) was used as a cationic dye, and methyl orange (MO) was used as an anionic dye. The study was carried out using a successive batch method for the dye absorption process and an equilibrium system to investigate the adsorption of MO on PAAM/chitosan hydrogels and MB on PAA/alginate in separate experiments. The results showed that the target hydrogels were synthetized with high yield (more than 90%). The chemical structure of the hydrogels was corroborated by FTIR, and their high thermal stability was verified by TGA. The absorption of the MO dye was higher at pH 3.0 using PAAM/chitosan, and it had the ability to remove 43% of MO within 10 min using 0.05 g of hydrogel. The presence of interfering salts resulted in a 20–60% decrease in the absorption of MO. On the other hand, the absorption of the MB dye was higher at pH 8.5 using PAA/alginate, and it had the ability to remove 96% of MB within 10 min using 0.05 g of hydrogel, and its removal capacity was stable for interfering salts.
Continuous Nanoprecipitation of Polycaprolactone in Additively Manufactured Micromixers
Authors: Göttert Simeon , Salomatov Irina , Eder Stephan , Seyfang Bernhard C. , Sotelo Diana C. , Osma Johann F. , Weiss Clemens K.
Published: April 2022

The polymeric ouzo effect is an energy-efficient and robust method to create nanoparticles with biologically degradable polymers. Usually, a discontinuous or semi-continuous process is employed due to its low technical effort and the fact that the amount of dispersions needed in a laboratory is relatively small. However, the number of particles produced in this method is not enough to make this process economically feasible. Therefore, it is necessary to improve the productivity of the process and create a controllable and robust continuous process with the potential to control parameters, such as the particle size or surface properties. In this study, nanoparticles were formulated from polycaprolactone (PCL) in a continuous process using additively manufactured micromixers. The main goal was to be able to exert control on the particle parameters in terms of size and zeta potential. The results showed that particle size could be adjusted in the range of 130 to 465 nm by using different flow rates of the organic and aqueous phase and varying concentrations of PCL dissolved in the organic phase. Particle surface charge was successfully shifted from a slightly negative potential of −14.1 mV to a negative, positive, or neutral value applying the appropriate surfactant. In summary, a continuous process of nanoprecipitation not only improves the cost of the method, but furthermore increases the control over the particle’s parameters.
Time-Resolved Radioluminescence Dosimetry Applications and the Influence of Ge Dopants In Silica Optical Fiber Scintillators
Authors: Tarif Zubair H. , Oresegun Adebiyi , Abubakar Auwal , Basaif Azmi , Zin Hafiz M. , Choo Kan Yeep , Ibrahim Siti A. , Abdul-Rashid Hairul Azhar , Bradley David A.
Published: April 2022

The quality of treatment delivery as prescribed in radiotherapy is exceptionally important. One element that helps provide quality assurance is the ability to carry out time-resolved radiotherapy dose measurements. Reports on doped silica optical fibers scintillators using radioluminescence (RL) based radiotherapy dosimetry have indicated merits, especially regarding robustness, versatility, wide dynamic range, and high spatial resolution. Topping the list is the ability to provide time-resolved measurements, alluding to pulse-by-pulse dosimetry. For effective time-resolved dose measurements, high temporal resolution is enabled by high-speed electronics and scintillator material offering sufficiently fast rise and decay time. In the present work, we examine the influence of Ge doping on the RL response of Ge-doped silica optical fiber scintillators. We particularly look at the size of the Ge-doped core relative to the fiber diameter, and its associated effects as it is adjusted from single-mode fiber geometry to a large core-to-cladding ratio structure. The primary objective is to produce a structure that facilitates short decay times with a sufficiently large yield for time-resolved dosimetry. RL characterization was carried out using a high-energy clinical X-ray beam (6 MV), delivered by an Elekta Synergy linear accelerator located at the Advanced Medical and Dental Institute, Universiti Sains Malaysia (USM). The Ge-doped silica optical fiber scintillator samples, fabricated using chemical vapor deposition methods, comprised of large core and small core optical fiber scintillators with high and low core-to-cladding ratios, respectively. Accordingly, these samples having different Ge-dopant contents offer distinct numbers of defects in the amorphous silica network. Responses were recorded for six dose-rates (between 35 MU/min and 590 MU/min), using a photomultiplier tube setup with the photon-counting circuit capable of gating time as small as 1 μs. The samples showed linear RL response, with differing memory and afterglow effects depending on its geometry. Samples with a large core-to-cladding ratio showed a relatively short decay time (<1 ms). The results suggest a contribution of Ge-doping in affecting the triplet states of the SiO2 matrix, thereby reducing phosphorescence effects. This is a desirable feature of scintillating glass materials that enables avoiding the pulse pile-up effect, especially in high dose-rate applications. These results demonstrate the potential of Ge-doped optical-fiber scintillators, with a large core-to-cladding ratio for use in time-resolved radiation dosimetry.
Unit-Linked Tontine: Utility-Based Design, Pricing and Performance
Authors: Chen An , Nguyen Thai , Sehner Thorsten
Published: April 2022

Due to the low demand for conventional annuities, alternative retirement products are sought. Quite recently, tontines have been frequently brought up as a promising option in this respect. Inspired by unit-linked life insurance and retirement products, we introduce unit-linked tontines in this article, where the tontine payoffs are directly linked to the development of the underlying financial market. More specifically, we consider two different tontine payoff structures differing in the (non-)inclusion of guaranteed payments. We first price the unit-linked tontines by using the risk-neutral pricing approach. Consequently, we study the attractiveness of these products for a utility-maximizing policyholder and compare them with non-unit-linked tontines. Our numerical analysis sheds light on the design challenges and gives explanations why similar products might not be widely adopted already.
Lake Expansion under the Groundwater Contribution in Qaidam Basin, China
Authors: Zhang Xi , Chen Jiaqi , Chen Jiansheng , Ma Fenyan , Wang Tao
Published: April 2022

The relationship between groundwater and lakes in Qaidam Basin is often overlooked. Therefore, we employed Landsat satellite images and meteorological data to investigate the causes of lake expansion through model calculation and statistical analysis and then determine groundwater sources through isotope analysis (2H, 3H, and 18O). In the two study periods of 2003–2011 and 2011–present, temperature, precipitation, and runoff increased at a steady rate, whereas the expansion rate of Tuosu Lake increased from 1.22 km2/yearr to 3.38 km2/yearr. This significant increase in the rate of lake expansion reflects the substantial contribution of groundwater to lake expansion. The groundwater contribution to the lake includes not only the glacial meltwater that infiltrates the piedmont plain but also other, more isotopically deleted water sources from other basins. It is speculated that the 2003 Ms 6.4 earthquake in the northwest of the Delingha region was a possible mechanism for lake expansion. Earthquakes can enhance crustal permeability and keep fractures open, which promotes groundwater contribution to lakes and in turn causes rapid lake expansion and an increased groundwater level. This study is important for understanding the sources, circulation, and evolution of groundwater in Qaidam Basin.
Combinations of Feature Selection and Machine Learning Algorithms for Object-Oriented Betel Palms and Mango Plantations Classification Based on Gaofen-2 Imagery
Authors: Luo Hongxia , Li Maofen , Dai Shengpei , Li Hailiang , Li Yuping , Hu Yingying , Zheng Qian , Yu Xuan , Fang Jihua
Published: April 2022

Betel palms and mango plantations are two crucial commercial crops in tropical agricultural areas. Accurate spatial distributions of these two crops are essential in tropical agricultural regional planning and management. However, the characteristics of small patches, scattering, and perennation make it challenging to map betel palms and mango plantations in complex tropical agricultural regions. Furthermore, the excessive features of very-high-resolution (VHR) imaging might lead to a reduction in classification accuracy and an increase in computation times. To address these challenges, we selected five feature selection (FS) methods (random forest means a decrease in accuracy (RFMDA), ReliefF, random forest-recursive feature elimination (RFE), aggregated boosted tree (ABT), and logistic regression (LR)) and four machine learning algorithms (random forest (RF), support vector machine (SVM), classification and regression tree (CART), and adaptive boosting (AdaBoost)). Then, the optimal combinations of FS and machine learning algorithms suited for object-oriented classification of betel palms and mango plantations were explored using VHR Gaofen-2 imagery. In terms of overall accuracy, all optimal classification schemes exceeded 80%, and the classifiers using selected features increased the overall accuracy between 1% and 4% compared with classification without FS methods. Specifically, LR was appropriate to RF and SVM classifiers, which produced the highest classification accuracy (89.1% and 89.88% for RF and SVM, respectively). In contrast, ABT and ReliefF were found to be suitable FS methods for CART and AdaBoost classifiers, respectively. Overall, all four optimal combinations of FS methods and classifiers could precisely recognize mango plantations, whereas betel palms were best depicted by using the RF-LR method with 26 features. The results indicated that combination of feature selection and machine learning algorithms contributed to the object-oriented classification of complex tropical crops using Gaofen-2 imagery, which provide a useful methodological reference for precisely recognizing small tropical agricultural patterns.
InSAR Study of Landslides: Early Detection, Three-Dimensional, and Long-Term Surface Displacement Estimation—A Case of Xiaojiang River Basin, China
Authors: Jia Hongying , Wang Yingjie , Ge Daqing , Deng Yunkai , Wang Robert
Published: April 2022

Landslides, a major natural geohazard, obstruct municipal constructions and may destroy villages and towns, at worst causing significant casualties and economic losses. Interferometric Synthetic Aperture Radar (InSAR) technique offers distinct advantages on landslide detection and monitoring. In this paper, a more systematic workflow is designed for InSAR study of landslides, in terms of three levels: (i) early detection on regional scale, (ii) three-dimensional (3D) surface displacement rates estimation on detailed scale, and (iii) time series analysis on long-term temporal scale. The proposed workflow is applied for landslide research on the Xiaojiang River Basin, China, using ascending and descending Sentinel-1 images acquired from March 2017 to May 2019. First, the landslide inventory has been mapped and updated using InSAR stacking method, supporting geohazard prevention on a regional scale. A total of 22 active landslides are identified, ranging from medium to super large scale. Compared with the existing inventory, three unrecorded landslides are newly detected by our approach, and five recorded landslides are detected significant expansion of their boundaries. Then, specific to a detected landslide, Baobao landslide, a Total Least Squares–Kalman Filter-based approach is presented. Two outcomes are provided for further spatial-temporal pattern analysis: 3D displacement rates, providing an intuitive insight on the spatial characteristics and sliding direction of landslide, which are analyzed to deep the understanding of its kinematic mechanism, and long-term time series, which contribute to deduce the dynamic evolution of landslide, presenting benefits in landslide forecasting.