bluuebunny/crossref_metadata_2025 huggingface dataset:
Safety Assessment of the Modified Lactoperoxidase System—In Vitro Studies on Human Gingival Fibroblasts
Authors: Magacz Marcin , Papież Monika , Kościelniak Dorota , Jurczak Anna , Kędziora Karolina , Pamuła Elżbieta , Krzyściak Wirginia
Published: January 2023

One strategy in caries prevention is to inhibit the formation of cariogenic biofilms. Attempts are being made to develop oral hygiene products enriched with various antimicrobial agents. One of them is lactoperoxidase—an enzyme that can oxidise (pseudo)halide ions to reactive products with antimicrobial activity. Currently, commercially available products utilise thiocyanate as a substrate; however, several alternatives that are oxidised to products with greater antimicrobial potential have been found. In this study, toxicity against human gingival fibroblasts of the lactoperoxidase system was evaluated using four different (pseudo)halide substrate systems—thiocyanate, iodide, selenocyanate, and a mixture of thiocyanate and iodide. For this purpose, cells were treated with the systems and then apoptosis, cell cycle, intracellular glutathione concentration, and mitochondrial superoxide production were assessed. The results showed that each system, after generating 250 µM of the product, inhibited cell divisions, increased apoptosis, and increased the percentage of dead cells. It was concluded that the mechanism of the observed phenomena was not related to increased superoxide production or the depletion of glutathione concentration. These findings emphasised the need for the further in vitro and in vivo toxicity investigation of the modified lactoperoxidase system to assess its safety and the possibility of use in oral hygiene products.
Investigating Therapeutic Effects of Indole Derivatives Targeting Inflammation and Oxidative Stress in Neurotoxin-Induced Cell and Mouse Models of Parkinson’s Disease
Authors: Chiu Ya-Jen , Lin Chih-Hsin , Lin Chung-Yin , Yang Pei-Ning , Lo Yen-Shi , Chen Yu-Chieh , Chen Chiung-Mei , Wu Yih-Ru , Yao Ching-Fa , Chang Kuo-Hsuan , Lee-Chen Guey-Jen
Published: January 2023

Neuroinflammation and oxidative stress have been emerging as important pathways contributing to Parkinson’s disease (PD) pathogenesis. In PD brains, the activated microglia release inflammatory factors such as interleukin (IL)-β, IL-6, tumor necrosis factor (TNF)-α, and nitric oxide (NO), which increase oxidative stress and mediate neurodegeneration. Using 1-methyl-4-phenylpyridinium (MPP+)-activated human microglial HMC3 cells and the sub-chronic 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced mouse model of PD, we found the potential of indole derivative NC009-1 against neuroinflammation, oxidative stress, and neurodegeneration for PD. In vitro, NC009-1 alleviated MPP+-induced cytotoxicity, reduced NO, IL-1β, IL-6, and TNF-α production, and suppressed NLR family pyrin domain containing 3 (NLRP3) inflammasome activation in MPP+-activated HMC3 cells. In vivo, NC009-1 ameliorated motor deficits and non-motor depression, increased dopamine and dopamine transporter levels in the striatum, and reduced oxidative stress as well as microglia and astrocyte reactivity in the ventral midbrain of MPTP-treated mice. These protective effects were achieved by down-regulating NLRP3, CASP1, iNOS, IL-1β, IL-6, and TNF-α, and up-regulating SOD2, NRF2, and NQO1. These results strengthen the involvement of neuroinflammation and oxidative stress in PD pathogenic mechanism, and indicate NC009-1 as a potential drug candidate for PD treatment.
Clathrin-Mediated Albumin Clearance in Alveolar Epithelial Cells of Murine Precision-Cut Lung Slices
Authors: Kryvenko Vitalii , Alberro-Brage Andrés , Fysikopoulos Athanasios , Wessendorf Miriam , Tello Khodr , Morty Rory E. , Herold Susanne , Seeger Werner , Samakovlis Christos , Vadász István
Published: January 2023

A hallmark of acute respiratory distress syndrome (ARDS) is an accumulation of protein-rich alveolar edema that impairs gas exchange and leads to worse outcomes. Thus, understanding the mechanisms of alveolar albumin clearance is of high clinical relevance. Here, we investigated the mechanisms of the cellular albumin uptake in a three-dimensional culture of precision-cut lung slices (PCLS). We found that up to 60% of PCLS cells incorporated labeled albumin in a time- and concentration-dependent manner, whereas virtually no uptake of labeled dextran was observed. Of note, at a low temperature (4 °C), saturating albumin receptors with unlabeled albumin and an inhibition of clathrin-mediated endocytosis markedly decreased the endocytic uptake of the labeled protein, implicating a receptor-driven internalization process. Importantly, uptake rates of albumin were comparable in alveolar epithelial type I (ATI) and type II (ATII) cells, as assessed in PCLS from a SftpcCreERT2/+: tdTomatoflox/flox mouse strain (defined as EpCAM+CD31−CD45−tdTomatoSPC−T1α+ for ATI and EpCAM+CD31−CD45−tdTomatoSPC+T1α− for ATII cells). Once internalized, albumin was found in the early and recycling endosomes of the alveolar epithelium as well as in endothelial, mesenchymal, and hematopoietic cell populations, which might indicate transcytosis of the protein. In summary, we characterize albumin uptake in alveolar epithelial cells in the complex setting of PCLS. These findings may open new possibilities for pulmonary drug delivery that may improve the outcomes for patients with respiratory failure.
Recent Advances in the Applications of Small Molecules in the Treatment of Multiple Myeloma
Authors: Abramson Hanley N.
Published: January 2023

Therapy for multiple myeloma (MM), a hematologic neoplasm of plasma cells, has undergone remarkable changes over the past 25 years. Small molecules (molecular weight of less than one kDa), together with newer immunotherapies that include monoclonal antibodies, antibody-drug conjugates, and most recently, chimeric antigen receptor (CAR) T-cells, have combined to double the disease’s five-year survival rate to over 50% during the past few decades. Despite these advances, the disease is still considered incurable, and its treatment continues to pose substantial challenges, since therapeutic refractoriness and patient relapse are exceedingly common. This review focuses on the current pipeline, along with the contemporary roles and future prospects for small molecules in MM therapy. While small molecules offer prospective benefits in terms of oral bioavailability, cellular penetration, simplicity of preparation, and improved cost–benefit considerations, they also pose problems of toxicity due to off-target effects. Highlighted in the discussion are recent developments in the applications of alkylating agents, immunomodulators, proteasome inhibitors, apoptosis inducers, kinesin spindle protein inhibitors, blockers of nuclear transport, and drugs that affect various kinases involved in intracellular signaling pathways. Molecular and cellular targets are described for each class of agents in relation to their roles as drivers of MM.
Theoretical Studies on Selectivity of HPK1/JAK1 Inhibitors by Molecular Dynamics Simulations and Free Energy Calculations
Authors: Ge Huizhen , Tang Chunchao , Pan Yiting , Yao Xiaojun
Published: January 2023

Hematopoietic progenitor kinase 1 (HPK1) is a negative regulator of T cell receptor, which has been regarded as a potential target for immunotherapy. Yu et al. observed the off-target effect of the high-throughput screening HPK1 kinase inhibitor hits on JAK1 kinase. The off-target effect is usually due to the lack of specificity of the drug, resulting in toxic side effects. Therefore, exploring the mechanisms to selectively inhibit HPK1 is critical for developing effective and safe inhibitors. In this study, two indazole compounds as HPK1 inhibitors with different selectivity towards JAK1 were used to investigate the selectivity mechanism using multiple computational methods, including conventional molecular dynamics simulations, binding free energy calculations and umbrella sampling simulations. The results indicate that the salt bridge between the inhibitor and residue Asp101 of HPK1 favors their selectivity towards HPK1 over JAK1. Information obtained from this study can be used to discover and design more potent and selective HPK1 inhibitors for immunotherapy.
Small Molecule EGFR Inhibitors as Anti-Cancer Agents: Discovery, Mechanisms of Action, and Opportunities
Authors: Zubair Tanzida , Bandyopadhyay Debasish
Published: January 2023

Epidermal growth factor receptors (EGFRs) are a class of receptor tyrosine kinase that are also called ErbB1 and HER1. EGFR tyrosine kinase activity inhibition is considered a promising therapeutic strategy for the treatment of cancer. Many small-molecule inhibitors of EGFR tyrosine kinase (EGFR-TK), from medicinally privileged molecules to commercial drugs, have been overviewed. Particular attention has been paid to the structure of the molecule and its mechanism of action if reported. Subsequent classification of the molecules under discussion has been carried out. Both natural and synthetic and reversible and irreversible EGFR-tyrosine kinase inhibitors have been discussed. Various types of cancers that are caused by overexpression of the EGFR gene, their possible molecular origins, and their natures have also been counted in this article. Because the EGFR signaling pathway controls the proliferation, growth, survival, and differentiation of cells, and the mutated EGFR gene overproduces EGFR protein, which ultimately causes several types of cancer, proper understanding of the molecular dynamics between the protein structure and its inhibitors will lead to more effective and selective EGFR-TKIs, which in turn will be able to save more lives in the battle against cancer.
Differential Roles of Cystathionine Gamma-Lyase and Mercaptopyruvate Sulfurtransferase in Hapten-Induced Colitis and Contact Dermatitis in Mice
Authors: Akahoshi Noriyuki , Hasegawa Ryoka , Yamamoto Shingo , Takemoto Rintaro , Yoshizawa Toshiki , Kamichatani Waka , Ishii Isao
Published: January 2023

Hydrogen sulfide (H2S) has been shown to act as both anti-inflammatory and pro-inflammatory mediators. Application of H2S donors generally protects against inflammation; however, experimental results using mice lacking endogenous H2S-producing enzymes, such as cystathionine γ-lyase (CTH) and mercaptopyruvate sulfurtransferase (MPST), are often contradictory. We herein examined two types of model hapten-induced inflammation models, colitis (an inflammatory bowel disease model of mucosal immunity) and contact dermatitis (a type IV allergic model of systemic immunity), in CTH-deficient (Cth–/–) and MPST-deficient (Mpst–/–) mice. Both mice exhibited no significant alteration from wild-type mice in trinitrobenzene sulfonic acid (Th1-type hapten)-induced colitis (a Crohn’s disease model) and oxazolone (Th1/Th2 mix-type; Th2 dominant)-induced colitis (an ulcerative colitis model). However, Cth–/– (not Mpst–/–) mice displayed more exacerbated phenotypes in trinitrochlorobenzene (TNCB; Th1-type)-induced contact dermatitis, but not oxazolone, at the delayed phase (24 h post-administration) of inflammation. CTH mRNA expression was upregulated in the TNCB-treated ears of both wild-type and Mpst–/– mice. Although mRNA expression of pro-inflammatory cytokines (IL-1β and IL-6) was upregulated in both early (2 h) and delayed phases of TNCB-triggered dermatitis in all genotypes, that of Th2 (IL-4) and Treg cytokines (IL-10) was upregulated only in Cth–/– mice, when that of Th1 cytokines (IFNγ and IL-2) was upregulated in wild-type and Mpst–/– mice at the delayed phase. These results suggest that (upregulated) CTH or H2S produced by it helps maintain Th1/Th2 balance to protect against contact dermatitis.
Engineering Interfacial Environment of Epigallocatechin Gallate Coated Titanium for Next-Generation Bioactive Dental Implant Components
Authors: Iviglia Giorgio , Morra Marco
Published: January 2023

In view of endowing the surface of abutments, a component of titanium dental implant systems, with antioxidant and antimicrobial properties, a surface layer coated with epigallocatechin gallate (EGCg), a polyphenol belonging to the class of flavonoids, was built on titanium samples. To modulate interfacial properties, EGCg was linked either directly to the surface, or after populating the surface with terminally linked polyethyleneglycol (PEG) chains, Mw ~1600 Da. The underlying assumption is that fouling-resistant, highly hydrated PEG chains could reduce non-specific bioadhesion and magnify intrinsic EGCg properties. Treated surfaces were investigated by a panel of surface/interfacial sensitive techniques, to provide chemico–physical characterization of the surface layer and its interfacial environment. Results show: (i) successful EGCg coupling for both approaches; (ii) that both approaches endow the Ti surface with the same antioxidant properties; (iii) that PEG-EGCg coated surfaces are more hydrophilic and show a significantly higher (>50%) interaction force with water. Obtained results build up a rationale basis for evaluation of the merits of finely tuning interfacial properties of polyphenols coated surfaces in biological tests.
Fermented Foods in the Management of Obesity: Mechanisms of Action and Future Challenges
Authors: Jalili Mahsa , Nazari Maryam , Magkos Faidon
Published: January 2023

Fermented foods are part of the staple diet in many different countries and populations and contain various probiotic microorganisms and non-digestible prebiotics. Fermentation is the process of breaking down sugars by bacteria and yeast species; it not only enhances food preservation but can also increase the number of beneficial gut bacteria. Regular consumption of fermented foods has been associated with a variety of health benefits (although some health risks also exist), including improved digestion, enhanced immunity, and greater weight loss, suggesting that fermented foods have the potential to help in the design of effective nutritional therapeutic approaches for obesity. In this article, we provide a comprehensive overview of the health effects of fermented foods and the corresponding mechanisms of action in obesity and obesity-related metabolic abnormalities.
Spawning-Induced pH Increase Activates Sperm Attraction and Fertilization Abilities in Eggs of the Ascidian, Phallusia philippinensis and Ciona intestinalis
Authors: Sensui Noburu , Itoh Yosinori , Okura Nobuhiko , Shiba Kogiku , Baba Shoji A. , Inaba Kazuo , Yoshida Manabu
Published: January 2023

In Phlebobranchiata ascidians, oocytes and spermatozoa are stored in the oviduct and spermiduct, respectively, until spawning occurs. Gametes in the gonoducts are mature and fertilizable; however, it was found that the gametes of the ascidians Phallusia philippinensis and Ciona intestinalis could not undergo fertilization in the gonoductal fluids. The body fluids of the ascidians, especially in the gonoducts, were much more acidic (pH 5.5–6.8) than seawater (pH 8.2), and the fertilization rate was low under such acidic conditions. Hence, we examined the effect of pH on gametes. Pre-incubation of gonoductal eggs at pH 8.2 prior to insemination increased fertilization rates, even when insemination was performed under low pH conditions. Furthermore, an increase in ambient pH induced an increase in the intracellular pH of the eggs. It was also found that an increase in ambient pH triggered the release of sperm attractants from the egg and is therefore necessary for sperm chemotaxis. Hence, acidic conditions in the gonoductal fluids keep the gametes, especially eggs, infertile, and the release of eggs into seawater upon spawning induces an increase in ambient pH, which enables egg fertilization.
Ultrastructural and Immunohistochemical Detection of Hydroxyapatite Nucleating Role by rRNA and Nuclear Chromatin Derivatives in Aortic Valve Calcification: In Vitro and In Vivo Pro-Calcific Animal Models and Actual Calcific Disease in Humans
Authors: Bonetti Antonella , Contin Magali , Marchini Maurizio , Ortolani Fulvia
Published: January 2023

Calcification starts with hydroxyapatite (HA) crystallization on cell membranous components, as with aortic valve interstitial cells (AVICs), wherein a cell-membrane-derived substance containing acidic phospholipids (PPM/PPLs) acts as major crystal nucleator. Since nucleic acid removal is recommended to prevent calcification in valve biosubstitutes derived from decellularized valve scaffolds, the involvement of ribosomal RNA (rRNA) and nuclear chromatin (NC) was here explored in three distinct contexts: (i) bovine AVIC pro-calcific cultures; (ii) porcine aortic valve leaflets that had undergone accelerated calcification after xenogeneic subdermal implantation; and (iii) human aortic valve leaflets affected by calcific stenosis. Ultrastructurally, shared AVIC degenerative patterns included (i) the melting of ribosomes with PPM/PPLs, and the same for apparently well-featured NC; (ii) selective precipitation of silver particles on all three components after adapted von Kossa reactions; and (iii) labelling by anti-rRNA immunogold particles. Shared features were also provided by parallel light microscopy. In conclusion, the present results indicate that rRNA and NC contribute to AVIC mineralization in vitro and in vivo, with their anionic charges enhancing the HA nucleation capacity exerted by PPM/PPL substrates, supporting the concept that nucleic acid removal is needed for valve pre-implantation treatments, besides better elucidating the modality of pro-calcific cell death.
Endocrine Disruptor Chemicals and Children’s Health
Authors: Di Pietro Giada , Forcucci Francesca , Chiarelli Francesco
Published: January 2023

We are all exposed to endocrine-disrupting chemicals (EDCs) starting from embryonic life. The fetus and child set up crucial developmental processes allowing adaptation to the environment throughout life: they are extremely sensitive to very low doses of hormones and EDCs because they are developing organisms. Considering the developmental origin of well-being and diseases, every adult organism expresses consequences of the environment in which it developed. The molecular mechanisms through which the main EDCs manifest their effects and their potential association with endocrine disorders, such as diabetes, obesity, thyroid disease and alteration of adrenal hormones, will be reviewed here. Despite 40 years having passed since the first study on EDCs, little is yet known about them; therefore, our purpose is to take stock of the situation to establish a starting point for further studies. Since there is plenty of evidence showing that exposure to EDCs may adversely impact the health of adults and children through altered endocrine function—suggesting their link to endocrinopathies—it is essential in this context to bear in mind what is already known about endocrine disruptors and to deepen our knowledge to establish rules of conduct aimed at limiting exposure to EDCs’ negative effects. Considering that during the COVID-19 pandemic an increase in endocrine disruptor effects has been reported, it will also be useful to address this new phenomenon for better understanding its basis and limiting its consequences.
Thermo-L-Asparaginases: From the Role in the Viability of Thermophiles and Hyperthermophiles at High Temperatures to a Molecular Understanding of Their Thermoactivity and Thermostability
Authors: Dumina Maria , Zhgun Alexander
Published: January 2023

L-asparaginase (L-ASNase) is a vital enzyme with a broad range of applications in medicine, food industry, and diagnostics. Among various organisms expressing L-ASNases, thermophiles and hyperthermophiles produce enzymes with superior performances—stable and heat resistant thermo-ASNases. This review is an attempt to take a broader view on the thermo-ASNases. Here we discuss the position of thermo-ASNases in the large family of L-ASNases, their role in the heat-tolerance cellular system of thermophiles and hyperthermophiles, and molecular aspects of their thermoactivity and thermostability. Different types of thermo-ASNases exhibit specific L-asparaginase activity and additional secondary activities. All products of these enzymatic reactions are associated with diverse metabolic pathways and are important for mitigating heat stress. Thermo-ASNases are quite distinct from typical mesophilic L-ASNases based on structural properties, kinetic and activity profiles. Here we attempt to summarize the current understanding of the molecular mechanisms of thermo-ASNases’ thermoactivity and thermostability, from amino acid composition to structural–functional relationships. Research of these enzymes has fundamental and biotechnological significance. Thermo-ASNases and their improved variants, cloned and expressed in mesophilic hosts, can form a large pool of enzymes with valuable characteristics for biotechnological application.
Assessment of the Permeability of 3,4-Methylenedioxypyrovalerone (MDPV) across the Caco-2 Monolayer for Estimation of Intestinal Absorption and Enantioselectivity
Authors: Almeida Ana Sofia , Silva Bárbara , Remião Fernando , Fernandes Carla
Published: January 2023

3,4-Methylenedioxypyrovalerone (MDPV) is a widely studied synthetic cathinone heterocycle mainly concerning its psychoactive effects. It is a chiral molecule and one of the most abused new psychoactive substances worldwide. Enantioselectivity studies for MDPV are still scarce and the extent to which it crosses the intestinal membrane is still unknown. Herein, an in vitro permeability study was performed to evaluate the passage of the enantiomers of MDPV across the Caco-2 monolayer. To detect and quantify MDPV, a UHPLC-UV method was developed and validated. Acceptable values within the recommended limits were obtained for all evaluated parameters (specificity, linearity, accuracy, limit of detection (LOD), limit of quantification (LOQ) and precision). The enantiomers of MDPV were found to be highly permeable across the Caco-2 monolayer, which can indicate a high intestinal permeability. Enantioselectivity was observed for the Papp values in the basolateral (BL) to apical (AP) direction. Furthermore, efflux ratios are indicative of efflux through a facilitated diffusion mechanism. To the best of our knowledge, determination of the permeability of MDPV across the intestinal epithelial cell monolayer is presented here for the first time.
Design Requirements for Personal Mobility Vehicle (PMV) with Inward Tilt Mechanism to Minimize Steering Disturbances Caused by Uneven Road Surface
Authors: Haraguchi Tetsunori , Kaneko Tetsuya
Published: February 2023

The Personal Mobility Vehicle (PMV), which has an inward-tilting angle, turns with lateral force due to a large camber angle, so it is necessary to consider the lateral movement of the tire vertical load axis during turning. Although the steering torque mechanisms are very different from those of automobiles, there are not many studies of the steering torque mechanisms of PMVs. In this paper, based on the effects of the force of six components acting on the tires, a method for setting the steering axis specifications is derived, including the geometrical minimization of steering moment disturbance due to the vertical load reaction force during turning. Automobile tires have a significant ground camber angle when traveling on rutted roads, but they do not have it on slanted roads because the vehicle body tilts along the road surface. On the other hand, in PMVs, the vehicle body always keeps upright when traveling both on slanted roads and on rutted roads. Therefore, the tires have ground camber angles on both types of road surface. We study the straight running ability under such road surface disturbances based on the geometrical minimization of steering moment disturbance due to the vertical load reaction force during turning. This straight running ability can be a remarkable strong point of PMVs with an inward tilt mechanism. In this study, it was proved that the steering axis parameters can be derived uniquely by taking into consideration the requirement to zero the moment (disturbance) around the steering axis due to the reaction force against the vertical load at all internal tilt angles.
Reduction in the Computational Complexity of Calculating Losses on Eddy Currents in a Hydrogen Fuel Cell Using the Finite Element Analysis
Authors: Khoroshev Artem , Vasyukov Ivan , Pavlenko Alexander , Batishchev Denis
Published: February 2023

This paper considers the issues of the reduction in the computational complexity of the numerical problem and the requirements of the computer memory size when calculating the power of the eddy currents in a hydrogen fuel cell based on a proton exchange membrane. The study was performed on a model problem based on a geometric pattern of a hydrogen fuel cell of typical dimensions and characteristics operating at a nominal load in steady-state conditions. The power of the eddy currents was calculated using a numerical model based on a tetrahedral finite element mesh and a mathematical model of a quasi-stationary electromagnetic field in the classical formulation through the vector magnetic potential. The requirements for the minimum degree of the geometric model approximation by a finite element mesh to achieve mesh stability of the computational problem results were defined. The paper considers issues of finite element order selection, the method of ordering, and the solution of the systems of linear algebraic equations (SLAEs). It shows the techniques for determining the accuracy of the calculated SLAE solution obtained by the direct method, as well as the effectiveness of the low-rank approximation of the SLAE to reduce the computational complexity of the computational problem solution and reduce the requirements for the amount of computer memory needed, considering the reduced accuracy of the SLAE solutions.
Optical Coherence Tomography Angiography in CRB1-Associated Retinal Dystrophies
Authors: Rajabian Firuzeh , Arrigo Alessandro , Bianco Lorenzo , Antropoli Alessio , Manitto Maria Pia , Martina Elisabetta , Bandello Francesco , Chhablani Jay , Battaglia Parodi Maurizio
Published: January 2023

Aim of the study: To report optical coherence tomography angiography (OCTA) findings in patients affected by CRB1-associated retinal dystrophies. Method: Patients affected by a genetically confirmed CRB1-associated retinal dystrophy were prospectively enrolled in an observational study, along with age- and sex-matched healthy volunteers as control subjects. All study and control subjects received a complete ophthalmic examination and multimodal retinal imaging, including OCTA. Result: A total of 12 eyes from 6 patients were included in the study. The mean BCVA of patients was 0.42 ± 0.25 logMAR. Two patients showed large central atrophy, with corresponding definite hypo-autofluorescence on fundus autofluorescence (FAF). Another four patients disclosed different degrees of RPE mottling, with uneven FAF. On OCTA, the macular deep capillary plexus and choriocapillaris had a lower vessel density in eyes affected by CRB1-associated retinopathy when compared to healthy controls. On the other hand, vessel density at the peripapillary radial capillary plexus, superficial capillary plexus, and deep capillary plexus was significantly altered with respect to control eyes. Statistical analyses disclosed a negative correlation between the deep capillary plexus and both LogMAR best corrected visual acuity and central retinal thickness. Conclusion: Our study reveals that CRB1-associated retinal dystrophies are characterized by vascular alterations both in the macular and peripapillary region, as assessed by OCTA.
Relationship between Maximum Force–Velocity Exertion and Swimming Performances among Four Strokes over Medium and Short Distances: The Stronger on Dry Land, the Faster in Water?
Authors: Sorgente Vincenzo , Agudo-Ortega Aaron , Lopez-Hernandez Alejandro , Santos del Cerro Jesus , Minciacchi Diego , González Ravé José María
Published: February 2023

Evaluating force–velocity characteristics on dry-land is of the utmost importance in swimming, because higher levels of these bio-motor abilities positively affect in-water performance. However, the wide range of possible technical specializations presents an opportunity for a more categorized approach that has yet to be seized. Therefore, the aim of this study was to identify feasible differences in maximum force–velocity exertion based on swimmers’ stroke and distance specialization. To this scope, 96 young male swimmers competing at the regional level were divided into 12 groups, one for each stroke (butterfly, backstroke, breaststroke, and front crawl) and distance (50 m, 100 m, and 200 m). They performed two single pull-up tests, 5-min before and after competing in a federal swimming race. We assessed force (N) and velocity (m/s) exertion via linear encoder. There were no significant differences between pre-post maximum force–velocity exertions, despite the decreasing trend. Force-parameters highly correlated with each other and with the swimming performance time. Moreover, both force (t = −3.60, p < 0.001) and velocity (t = −3.90, p < 0.001) were significant predictors of swimming race time. Sprinters (both 50 m and 100 m) of all strokes could exert significantly higher force–velocity compared to 200 m swimmers (e.g., 0.96 ± 0.06 m/s performed by sprinters vs. 0.66 ± 0.03 m/s performed by 200 m swimmers). Moreover, breaststroke sprinters presented significantly lower force–velocity compared to sprinters specialized in the other strokes (e.g., 1047.83 ± 61.33 N performed by breaststroke sprinters vs. 1263.62 ± 161.23 N performed by butterfly sprinters). This study could provide the foundation for future research regarding the role of stroke and distance specializations in modeling swimmers’ force–velocity abilities, thus influencing paramount elements for specific training and improvement towards competitions.
Quantized Sliding Mode Fault-Tolerant Control for Unmanned Marine Vehicles with Thruster Saturation
Authors: Hao Li-Ying , Zhao Zhi-Hao
Published: February 2023

In this paper, the sliding mode technique is used to study the quantized fault-tolerant control of unmanned marine vehicles with thruster saturation. Firstly, the sliding mode surface is constructed according to the full rank decomposition of input matrix, and the stability of sliding mode is guaranteed by linear matrix inequalities. An improved dynamic adjustment scheme of quantization parameter is proposed. Compared with the original adjustment scheme, the relationship between quantization parameter and desired targets is increased, so that the adjustment range of quantization parameters is more comprehensive. The sliding mode controller is combined with quantization parameter adjustment strategy to ensure the asymptotic stability of unmanned marine vehicles system. In addition, compared with the existing research results of quantitative fault tolerance problem without considering saturation, this paper gives a result of the domain of attraction affected by the fault of the thruster. Finally, the superiority of the proposed method is verified by simulation comparison.
Crab Species-Specific Excavation and Architecture of Burrows in Restored Mangrove Habitat
Authors: Min Wah Wah , Kandasamy Kathiresan , Balakrishnan Balasubramaniyan
Published: February 2023

Burrowing crabs are considered to be ecosystem engineers, playing a vital role in mangrove ecosystems through bio-geochemical transformation. This process depends on the size and shape of burrows. The present study analyzes the architecture of burrows constructed by crabs in a restored mangrove habitat. Fourteen crab species were found to construct burrows of 13 different shapes, with a predominance of I-, J-, and L-shapes. Sesarmids were larger in size than fiddlers, and made burrows with wider openings mostly in the Rhizophora zone. Fiddlers constructed complex burrows with a vertical position, and made longer and deeper burrows in contrast to sesarmids, which formed simple burrows with a horizontal position, digging shorter and shallower burrows in Avicennia or open zones. The sesarmids had smaller burrows without branching in mangrove zones, whereas the fiddlers had larger burrows with or without branching in open and Avicennia zones. The burrows of fiddler crabs, especially Austruca occidentalis and A. annulipes, had separate openings and passages for exit and entry as an adaptation against predators. The present work identified Austruca occidentalis and A. annulipes as the most potent bioturbating crab species in restored mangrove habitats due to their efficiency in soil excavation and formation of large-sized burrows.
Digital Governance Approach to the Spanish Port System: Proposal for a Port
Authors: Gómez Díaz Cristina , González-Cancelas Nicoletta , Camarero Orive Alberto , Soler Flores Francisco
Published: February 2023

The global changes that are currently taking place and which are driven by new forms of communication, behaviours, innovative technologies, etc., mean that ports have to be aware of or take into account these new trends. They have and must actively participate in this global change and become the leaders of the transformation. The main objective of this study was to carry out an in-depth analysis of the digital governance approach to the Spanish Port System. The Business Observation Tool (BOT) was used with a SWOT matrix to identify how the study environment is doing and to be able to identify those indicators that have the potential to form, as far as possible, a better approach to digital governance in Spain. The aim is to ensure that in the current technological era, the Spanish port sector evolves in terms of port digitalisation in order to adapt to the coming changes and continues to develop towards a more digitally interconnected future. It can be concluded that the indicators obtained from the technological field are the most predominant in the analysis carried out.
Severe COVID-19 Infection during Pregnancy Requiring ECMO: Case Report and Review of the Literature
Authors: Diago-Muñoz Diana , Martínez-Varea Alicia , Pérez-Sancho Esther , Diago-Almela Vicente
Published: January 2023

Background: The risk of developing severe COVID-19 that requires admission to an intensive care unit (ICU) and invasive ventilation is increased in pregnant women. Extracorporeal membrane oxygenation (ECMO) has been successfully used to manage critical pregnant and peripartum patients. Case Report: A 40-year-old patient, unvaccinated for COVID-19, presented to a tertiary hospital in January 2021 at 23 weeks of gestation due to respiratory distress, cough, and fever. The patient had a confirmed diagnosis of SARS-CoV-2 with a PCR test in a private center 48 h before. She required admission into the ICU due to respiratory failure. High-flow nasal oxygen therapy, intermittent noninvasive mechanical ventilation (BiPAP), mechanical ventilation, prone positioning, and nitric oxide therapy were administered. Additionally, hypoxemic respiratory failure was diagnosed. Thus, circulatory assistance using ECMO with venovenous access was performed. After 33 days of ICU admission, the patient was transferred to the internal medicine department. She was discharged 45 days after hospital admission. At 37 weeks of gestation, the patient presented active labor and underwent an uneventful vaginal delivery. Conclusions: Severe COVID-19 in pregnancy may lead to the requirement for ECMO administration. This therapy should be administered in specialized hospitals using a multidisciplinary approach. COVID-19 vaccination should be strongly recommended to pregnant women to decrease the risk of severe COVID-19.
Risk Aversion and Perception of Farmers about Endogenous Risks: An Empirical Study for Maize Producers in Awi Zone, Amhara Region of Ethiopia
Authors: Girma Yohannes , Kuma Berhanu , Bedemo Amsalu
Published: February 2023

Agriculture is a risky business that is subject to endogenous risks. Endogenous risks caused by input utilization, input affordability and input availability may prove detrimental to the production potential of farmers. The study was aimed at examining the risk perception, risk aversion and risk management strategies of maize producers in Awi zone, which is found in the northwest part of Ethiopia. The study involved 343 respondents who produced maize under risk. Descriptive statistics, a seven-point Likert scale, the observed economic behaviour method, factor analysis and a seemingly unrelated regression model were used to process the data. The results showed that farmers have different perceptions of the endogenous risk associated with input availability and input affordability which has a different probability of occurrence and severity of damage. The observed economic behaviour method showed that farmers in the area also have different risk aversion behaviours: about 7.29% of the respondents in the study area have high risk aversion attitudes, while about 30.61% have medium risk aversion attitudes and 62.10% of them have low risk aversion attitudes. The seemingly unrelated regression model output showed that farmers’ economic, social, demographic and institutional factors, as well as their risk behaviour, determine the risk management strategies that they employ. Maize farmers in the area applied human risk management strategies, production risk management strategies, diversification, financial risk management strategies and marketing risk management strategies to tackle the endogenous risks in the area. It was deduced that maize farmers have a risk averse behaviour even if their risk aversion levels differ based on the scope of the management strategies that they employ to combat risk. Following the finding of the study, a holistic approach to risk management that encompasses all actors, such as farmers, researchers, extension services and financial institutions should be involved to make the appropriate interventions.
Sound-Based Intelligent Detection of FOD in the Final Assembly of Rocket Tanks
Authors: Lin Tantao , Zhu Yongsheng , Ren Zhijun , Huang Kai , Zhang Xinzhuo , Yan Ke , Huang Shunzhou
Published: January 2023

The traditional method of relying on human hearing to detect foreign object debris (FOD) events during rocket tank assembly processes has the limitation of strong reliance on humans and difficulty in establishing objective detection records. This can lead to undetected FOD entering the engine with the fuel and causing major launch accidents. In this study, we developed an automatic, intelligent FOD detection system for rocket tanks based on sound signals to overcome the drawbacks of manual detection, enabling us to take action to prevent accidents in advance. First, we used log-Mel transformation to reduce the high sampling rate of the sound signal. Furthermore, we proposed a multiscale convolution and temporal convolutional network (MS-CTCN) to overcome the challenges of multi-scale temporal feature extraction to detect suspicious FOD events. Finally, we used the proposed post-processing strategies of label smoothing and threshold discrimination to refine the results of FOD event detection and ultimately determine the presence of FOD. The proposed method was validated through FOD experiments. The results showed that the method had an accuracy rate of 99.16% in detecting FOD and had a better potential to prevent accidents compared to the baseline method.
Human–Machine Relationship—Perspective and Future Roadmap for Industry 5.0 Solutions
Authors: Pizoń Jakub , Gola Arkadiusz
Published: February 2023

The human–machine relationship was dictated by human needs and what technology was available at the time. Changes within this relationship are illustrated by successive industrial revolutions as well as changes in manufacturing paradigms. The change in the relationship occurred in line with advances in technology. Machines in each successive century have gained new functions, capabilities, and even abilities that are only appropriate for humans—vision, inference, or classification. Therefore, the human–machine relationship is evolving, but the question is what the perspective of these changes is and what developmental path accompanies them. This question represents a research gap that the following article aims to fill. The article aims to identify the status of change and to indicate the direction of change in the human–machine relationship. Within the framework of the article, a literature review has been carried out on the issue of the human–machine relationship from the perspective of Industry 5.0. The fifth industrial revolution is restoring the importance of the human aspect in production, and this is in addition to the developments in the field of technology developed within Industry 4.0. Therefore, a broad spectrum of publications has been analyzed within the framework of this paper, considering both specialist articles and review articles presenting the overall issue under consideration. To demonstrate the relationships between the issues that formed the basis for the formulation of the development path.
Green Human Resources and Innovative Performance in Small- and Medium-Sized Tourism Enterprises: A Mediation Model Using PLS-SEM Data Analysis
Authors: Elshaer Ibrahim A. , Azazz Alaa M. S. , Fayyad Sameh
Published: January 2023

Small- and medium-sized enterprises (SMEs), like large corporations, confront new issues related to business sustainability, which necessitates playing a part in environmental protection and enhancing environment-based human resources management strategies in order to remain in business. Green human resources management practices (GHRMPs) have been found to positively impact innovative performance. However, the mechanisms by which GHRMPs influence innovation are not well understood. This study aimed to examine the mediating role of individual green values and job satisfaction in the relationship between GHRMPs and innovative performance. Using a sample of 605 small- and medium-sized (SMEs) hotels and travel agents, structural equation modeling (PLS-SEM) was conducted using SmartPLS program v4 to analyze the obtained data. The study found that GHRMPs were positively related to both individual green values and job satisfaction, and in turn, individual green values and job satisfaction were positively related to innovative performance. The results of this study suggest that individual green values and job satisfaction play a significant mediating role in the relationship between GHRMPs and innovative performance. Practical and theoretical implications were elaborated on and discussed.
Red–Blue k-Center Clustering with Distance Constraints
Authors: Eskandari Marzieh , Khare Bhavika B. , Kumar Nirman , Sadeghi Bigham Bahram
Published: February 2023

We consider a variant of the k-center clustering problem in IRd, where the centers can be divided into two subsets—one, the red centers of size p, and the other, the blue centers of size q, such that p+q=k, and each red center and each blue center must be a distance of at least some given α≥0 apart. The aim is to minimize the covering radius. We provide a bi-criteria approximation algorithm for the problem and a polynomial time algorithm for the constrained problem where all centers must lie on a given line ℓ. Additionally, we present a polynomial time algorithm for the case where only the orientation of the line is fixed in the plane (d=2), although the algorithm works even in IRd by constraining the line to lie in a plane and with a fixed orientation.
Levenberg–Marquardt Training Technique Analysis of Thermally Radiative and Chemically Reactive Stagnation Point Flow of Non-Newtonian Fluid with Temperature Dependent Thermal Conductivity
Authors: Rehman Khalil Ur , Shatanawi Wasfi , Çolak Andaç Batur
Published: February 2023

We have examined the magnetized stagnation point flow of non-Newtonian fluid towards an inclined cylindrical surface. The mixed convection, thermal radiation, viscous dissipation, heat generation, first-order chemical reaction, and temperature-dependent thermal conductivity are the physical effects being carried for better novelty. Mathematical equations are constructed for four different flow regimes. The shooting method is used to evaluate the heat transfer coefficient at the cylindrical surface with and without heat generation/thermal radiation effects. For better examination, we have constructed artificial neural networking models with the aid of the Levenberg–Marquardt training technique and Purelin and Tan-Sig transfer functions. The Nusselt number strength is greater for fluctuations in the Casson fluid parameter, Prandtl number, heat generation, curvature, and Eckert number when thermal radiations are present.
Entropy Generation of Cu–Al2O3/Water Flow with Convective Boundary Conditions through a Porous Stretching Sheet with Slip Effect, Joule Heating and Chemical Reaction
Authors: Joyce Maria Immaculate , Kandasamy Jagan , Sivanandam Sivasankaran
Published: February 2023

Currently, the efficiency of heat exchange is not only determined by enhancements in the rate of heat transfer but also by economic and accompanying considerations. Responding to this demand, many scientists have been involved in improving heat transfer performance, which is referred to as heat transfer enhancement, augmentation, or intensification. This study deals with the influence on hybrid Cu–Al2CO3/water nanofluidic flows on a porous stretched sheet of velocity slip, convective boundary conditions, Joule heating, and chemical reactions using an adapted Tiwari–Das model. Nonlinear fundamental equations such as continuity, momentum, energy, and concentration are transmuted into a non-dimensional ordinary nonlinear differential equation by similarity transformations. Numerical calculations are performed using HAM and the outcomes are traced on graphs such as velocity, temperature, and concentration. Temperature and concentration profiles are elevated as porosity is increased, whereas velocity is decreased. The Biot number increases the temperature profile. The rate of entropy is enhanced as the Brinkman number is raised. A decrease in the velocity is seen as the slip increases.
New Nostocyclophanes from Nostoc linckia
Authors: Dai Jingqiu , Philbin Casey S. , Wakano Clay , Yoshida Wesley Y. , Williams Philip G.
Published: January 2023

Six new nostocyclophanes and four known compounds have been isolated from Nostoc linckia (Nostocaceae) cyanobacterial strain UTEX B1932. The new compounds, nostocyclophanes E–J (1–6), were characterized by NMR and MS techniques. The known compounds were nostocyclophanes B–D, previously isolated from this strain, and dedichloronostocyclophane D. Structural modifications on the new [7.7]paracyclophane analogs 1–5, isolated from the 80% methanol fraction, range from simple changes such as the lack of methylation or halogenation to more unusual modifications such as those seen in nostocyclophane H (4), in which the exocyclic alkyl chains are of different length; this is the first time this modification has been observed in this family of natural products. In addition, nostocyclophane J (6) is a linear analog in which C-20 is chlorinated in preparation for the presumed enzymatic Friedel–Craft cyclization needed to form the final ring structure, analogous to the biosynthesis of the related cylindrocyclophanes. Nostocyclophane D, dedichloronostocyclophane D, and nostocyclophanes E-J demonstrated moderate to weak growth inhibition against MDA-MB-231 breast cancer cells.