bluuebunny/crossref_metadata_2025 huggingface dataset:
Anti-Inflammatory Effects of Peripheral Dopamine
Authors: Moore Shaun C. , Vaz de Castro Pedro A. S. , Yaqub Daniel , Jose Pedro A. , Armando Ines
Published: September 2023

Dopamine is synthesized in the nervous system where it acts as a neurotransmitter. Dopamine is also synthesized in a number of peripheral organs as well as in several types of cells and has organ-specific functions and, as demonstrated more recently, is involved in the regulation of the immune response and inflammatory reaction. In particular, the renal dopaminergic system is very important in the regulation of sodium transport and blood pressure and is particularly sensitive to stimuli that cause oxidative stress and inflammation. This review is focused on how dopamine is synthesized in organs and tissues and the mechanisms by which dopamine and its receptors exert their effects on the inflammatory response.
New Functional Alkoxysilanes and Silatranes: Synthesis, Structure, Properties, and Possible Applications
Authors: Adamovich Sergey N. , Nalibayeva Arailym M. , Abdikalykov Yerlan N. , Ushakov Igor A. , Oborina Elizaveta N. , Rozentsveig Igor B.
Published: September 2023

The aza-Michael reaction of 3-aminopropyltriethoxysilane (1) and -silatrane (2) with acrylates affords functionalized silyl-(3–8) and silatranyl-(9–14) mono- and diadducts with up to a 99% yield. Their structure has been proved with IR and NMR spectroscopies, mass spectrometry and XRD analysis. The hydrolytic homo-condensation of triethoxysilanes 3–5 gives siloxanes 3a–5a, which form complexes with Ag, Cu, and Ni salts. They are also able to adsorb these metals from solutions. The hetero-condensation reaction of silanes 4–8 with OH groups of zeolite (Z), silica gel (S) and glass (G) delivers the modified materials (Z4, S7, G4, G5, G7, G8, etc.), which can adsorb ions of noble metal (Au, Rh, Pd: G4 + Au, G5 + Pd, G7 + Rh). Thus, the synthesized Si-organic polymers and materials turned out to be promising sorbents (enterosorbents) of noble, heavy, toxic metal ions and can be applied in industry, environment, and medicine.
Guanylation Reactions for the Rational Design of Cancer Therapeutic Agents
Authors: del Campo-Balguerías Almudena , Parra-Cadenas Blanca , Nieto-Jimenez Cristina , Bravo Iván , Ripoll Consuelo , Poyatos-Racionero Elisa , Gancarski Pawel , Carrillo-Hermosilla Fernando , Alonso-Moreno Carlos , Ocaña Alberto
Published: September 2023

The modular synthesis of the guanidine core by guanylation reactions using commercially available ZnEt2 as a catalyst has been exploited as a tool for the rapid development of antitumoral guanidine candidates. Therefore, a series of phenyl-guanidines were straightforwardly obtained in very high yields. From the in vitro assessment of the antitumoral activity of such structurally diverse guanidines, the guanidine termed ACB3 has been identified as the lead compound of the series. Several biological assays, an estimation of AMDE values, and an uptake study using Fluorescence Lifetime Imaging Microscopy were conducted to gain insight into the mechanism of action. Cell death apoptosis, induction of cell cycle arrest, and reduction in cell adhesion and colony formation have been demonstrated for the lead compound in the series. In this work, and as a proof of concept, we discuss the potential of the catalytic guanylation reactions for high-throughput testing and the rational design of guanidine-based cancer therapeutic agents.
HCN2 Channels in the Ventral Hippocampal CA1 Regulate Nociceptive Hypersensitivity in Mice
Authors: Zheng Yawen , Shao Shan , Zhang Yu , Yuan Shulu , Xing Yuanwei , Wang Jiaxin , Qi Xuetao , Cui Kun , Tong Jifu , Liu Fengyu , Cui Shuang , Wan You , Yi Ming
Published: September 2023

Chronic pain is a significant health problem worldwide. Recent evidence has suggested that the ventral hippocampus is dysfunctional in humans and rodents, with decreased neuronal excitability and connectivity with other brain regions, parallel pain chronicity, and persistent nociceptive hypersensitivity. But the molecular mechanisms underlying hippocampal modulation of pain remain poorly elucidated. In this study, we used ex vivo whole-cell patch-clamp recording, immunofluorescence staining, and behavioral tests to examine whether hyperpolarization-activated cyclic nucleotide-gated channels 2 (HCN2) in the ventral hippocampal CA1 (vCA1) were involved in regulating nociceptive perception and CFA-induced inflammatory pain in mice. Reduced sag potential and firing rate of action potentials were observed in vCA1 pyramidal neurons from CFA-injected mice. Moreover, the expression of HCN2, but not HCN1, in vCA1 decreased in mice injected with CFA. HCN2 knockdown in vCA1 pyramidal neurons induced thermal hypersensitivity, whereas overexpression of HCN2 alleviated thermal hyperalgesia induced by intraplantar injection of CFA in mice. Our findings suggest that HCN2 in the vCA1 plays an active role in pain modulation and could be a promising target for the treatment of chronic pain.
Adaptation of the Endolithic Biome in Antarctic Volcanic Rocks
Authors: Hidalgo-Arias Andrea , Muñoz-Hisado Víctor , Valles Pilar , Geyer Adelina , Garcia-Lopez Eva , Cid Cristina
Published: September 2023

Endolithic microorganisms, ranging from microeukaryotes to bacteria and archaea, live within the cracks and crevices of rocks. Deception Island in Antarctica constitutes an extreme environment in which endoliths face environmental threats such as intense cold, lack of light in winter, high solar radiation in summer, and heat emitted as the result of volcanic eruptions. In addition, the endolithic biome is considered the harshest one on Earth, since it suffers added threats such as dryness or lack of nutrients. Even so, samples from this hostile environment, collected at various points throughout the island, hosted diverse and numerous microorganisms such as bacteria, fungi, diatoms, ciliates, flagellates and unicellular algae. These endoliths were first identified by Scanning Electron Microscopy (SEM). To understand the molecular mechanisms of adaptation of these endoliths to their environment, genomics techniques were used, and prokaryotic and eukaryotic microorganisms were identified by metabarcoding, sequencing the V3–V4 and V4–V5 regions of the 16S and 18S rRNA genes, respectively. Subsequently, the sequences were analyzed by bioinformatic methods that allow their metabolism to be deduced from the taxonomy. The results obtained concluded that some of these microorganisms have activated the biosynthesis routes of pigments such as prodigiosin or flavonoids. These adaptation studies also revealed that microorganisms defend themselves against environmental toxins by activating metabolic pathways for the degradation of compounds such as ethylbenzene, xylene and dioxins and for the biosynthesis of antioxidant molecules such as glutathione. Finally, these Antarctic endolithic microorganisms are of great interest in astrobiology since endolithic settings are environmentally analogous to the primitive Earth or the surfaces of extraterrestrial bodies.
Autophagy Modulation as a Potential Therapeutic Strategy in Osteosarcoma: Current Insights and Future Perspectives
Authors: Almansa-Gómez Sergio , Prieto-Ruiz Francisco , Cansado José , Madrid Marisa
Published: September 2023

Autophagy, the process that enables the recycling and degradation of cellular components, is essential for homeostasis, which occurs in response to various types of stress. Autophagy plays an important role in the genesis and evolution of osteosarcoma (OS). The conventional treatment of OS has limitations and is not always effective at controlling the disease. Therefore, numerous researchers have analyzed how controlling autophagy could be used as a treatment or strategy to reverse resistance to therapy in OS. They highlight how the inhibition of autophagy improves the efficacy of chemotherapeutic treatments and how the promotion of autophagy could prove positive in OS therapy. The modulation of autophagy can also be directed against OS stem cells, improving treatment efficacy and preventing cancer recurrence. Despite promising findings, future studies are needed to elucidate the molecular mechanisms of autophagy and its relationship to OS, as well as the mechanisms underlying the functioning of autophagic modulators. Careful evaluation is required as autophagy modulation may have adverse effects on normal cells, and the optimization of autophagic modulators for use as drugs in OS is imperative.
Viroporins of Mpox Virus
Authors: Basu Kingshuk , Krugliak Miriam , Arkin Isaiah T.
Published: September 2023

Mpox or monkeypox virus (MPXV) belongs to the subclass of Poxviridae and has emerged recently as a global threat. With a limited number of anti-viral drugs available for this new virus species, it is challenging to thwart the illness it begets. Therefore, characterizing new drug targets in the virus may prove advantageous to curbing the disease. Since channels as a family are excellent drug targets, we have sought to identify viral ion channels for this virus, which are instrumental in formulating channel-blocking anti-viral drugs. Bioinformatics analyses yielded eight transmembranous proteins smaller or equal to 100 amino acids in length. Subsequently, three independent bacteria-based assays have pointed to five of the eight proteins that exhibit ion channel activity. Finally, we propose a tentative structure of four ion channels from their primary amino acid sequences, employing AlphaFold2 and molecular dynamic simulation methods. These results may represent the first steps in characterizing MPXV viroporins en route to developing blockers that inhibit their function.
Isocyanide Cycloaddition and Coordination Processes at Trigonal Phosphinidene-Bridged MoRe and MoMn Complexes
Authors: Alvarez M. Angeles , García M. Esther , García-Vivó Daniel , Ruiz Miguel A. , Vega Patricia
Published: September 2023

Heterometallic phosphinidene complexes are appealing species for the construction of novel organophosphorus ligands thanks to the high reactivity expected from the combination of M-P multiple bonding and the intrinsically different electronic and coordination preferences of the distinct metals. In a preliminary study, we found that the heterobimetallic complex [MoReCp(μ-PMes*)(CO)6] (Mes* = 2,4,6-C6H2tBu3) reacted with CN(p-C6H4OMe) via [2+1]-cycloaddition to form a novel azaphosphallene complex. We have now examined in detail the reactions of the above complex and those of its MoMn analogue with different isocyanides, which turned out to be strongly dependent on experimental conditions and on the size of the substituent at the isocyanide. All the products formed follow from one or several of the following reaction pathways: (i) CO substitution by CNR; (ii) addition of CNR at the group 7 metal centre; and (iii) [2+1] cycloaddition of isocyanide at a Mo=P bond to form azaphosphallene groups, with the former process being dominant in reactions at room temperature and for the Mn system. In contrast, low-temperature reactions of the Re system favoured the addition processes, with the [2+1] cycloaddition at Mo=P bonds only taking place at substrates without metal-metal bonds and when the size of the CNR group does not cause unbearable steric clashes when placed in between the Cp and Mes* groups.
Dibromo- and Dichlorotriphenylphosphino N-Acyclic Carbene Complexes of Platinum(II)—Synthesis and Cytotoxicity
Authors: Farasat Anna , Labella Luca , Di Paolo Maria Luisa , Dalla Via Lisa , Samaritani Simona
Published: September 2023

Some new dichloro- and dibromotriphenylphosphino isonitrile and N-acyclic (NAC) carbene complexes of platinum(II) were synthesized, starting from suitable dinuclear precursors. The reaction of cyclohexylisonitrile with trans-[Pt(μ-X)X(PPh3)]2, followed by the addition of N,N-diethylamine afforded the corresponding N-acyclic carbene (NAC)derivatives cis-[PtX2(PPh3)(NAC)] in 61–64% isolated yield. The cis geometry was attributed based on the comparison with known structures. The stability of the complexes in pure DMSO, DMSO/H2O, and DMSO/NaClaq mixtures was evaluated. While pure DMSO, as well as DMSO/H2O, did not affect the nature of either dichloro- or dibromo-compounds, dibromo derivatives were not stable in the presence of chloride ions. Since a high concentration of chloride ions is essential to perform in vitro cell assays, only dichlorocomplexes were tested as cytotoxic agents against HepG2 and human tumor cells. Among the tested complexes, NAC derivatives showed a moderate effect on MSTO-211H.
Performance of the Aptis Distal Radioulnar Joint Implant: A Clinical Case Series Including Four-Dimensional Computed Tomography Kinematic Analysis
Authors: Stougie Shirley D. , van Doesburg Margriet H. M. , Oonk Joris G. M. , Plugge Lara , Streekstra Geert J. , Dobbe Johannes G. G. , Coert Jan Henk
Published: September 2023

High complication rates and surgical revision rates following Aptis implant placement have been reported in the literature. This study evaluates the performance of the Aptis implant of twelve patients using four-dimensional kinematic analysis. The (mean) follow-up was 58 months. Wrist motion, grip strength, and kinematic analysis of both arms were used to investigate possible causes of the reported complications. In nine cases (75%), the proximal to distal translation of the distal radius along the ulnar axis in the affected forearm was too little or absent. Significant correlations were found between postoperative extension and translation of the distal radius along the ulnar axis and between the radial deviation and combined error. The four-dimensional kinematic analysis suggests that the current design of the implant could lead to limited restoration of the position of the forearm rotation axis and the translation of the radius along the ulnar axis.
Harnessing Immune Response in Acute Myeloid Leukemia
Authors: Riva Carola , Vernarecci Chiara , Minetto Paola , Goda Rayan , Greppi Marco , Pesce Silvia , Chies Maria , Zecchetti Giada , Ferro Beatrice , Maio Elena , Cea Michele , Lemoli Roberto Massimo , Marcenaro Emanuela , Guolo Fabio
Published: September 2023

Despite the results achieved with the evolution of conventional chemotherapy and the inclusion of targeted therapies in the treatment of acute myeloid leukemia (AML), survival is still not satisfying, in particular in the setting of relapsed/refractory (R/R) disease or elderly/unfit patients. Among the most innovative therapeutic options, cellular therapy has shown great results in different hematological malignancies such as acute lymphoblastic leukemia and lymphomas, with several products already approved for clinical use. However, despite the great interest in also expanding the application of these new treatments to R/R AML, no product has been approved yet for clinical application. Furthermore, cellular therapy could indeed represent a powerful tool and an appealing alternative to allogeneic hematopoietic stem cell transplantation for ineligible patients. In this review, we aim to provide an overview of the most recent clinical research exploring the effectiveness of cellular therapy in AML, moving from consolidated approaches such as post- transplant donor’s lymphocytes infusion, to modern adoptive immunotherapies such as alloreactive NK cell infusions, engineered T and NK cells (CAR-T, CAR-NK) and novel platforms of T and NK cells engaging (i.e., BiTEs, DARTs and ANKETTM).
Role of Macrophage Colony-Stimulating Factor for Staphylococcal Infection in the Oral Cavity
Authors: Senpuku Hidenobu , Yoshimura Kazuhisa , Takai Hideki , Maruoka Yutaka , Yamashita Erika , Tominaga Akira , Ogata Yorimasa
Published: September 2023

Objective: There are few valid indicators of oral infection owing to the complexity of pathogenic factors in oral diseases. Salivary markers are very useful for scrutinizing the symptoms of disease. To provide a reliable and useful predictive indicator of infection for opportunistic pathogens in individuals with compromised immune systems, such as those with periodontal diseases and Human Immunodeficiency Virus (HIV), this study examines opportunistic pathogens such as C. albicans and staphylococci and macrophage colony-stimulating factor (M-CSF) and CA125/MUC16 in saliva. The aim was to explore the correlations investigated among these factors. Methods: Samples were divided into two groups (based on patient sex, the absence and presence of dentures in elderly, or HIV-positive patients and healthy subjects), and the correlation was analyzed in two groups of elderly patients with periodontal disease (64.5 ± 11.2 years old) and HIV-infected patients (41.9 ± 8.4 years old). Healthy subjects (33.8 ± 9.1 years old) were also analyzed as a control. Levels of C. albicans, staphylococci, and M-CSF, which is an immunological factor for the differentiation of macrophage, and CA125/MUC16, which provides a protective lubricating barrier against infection, were investigated. Results: A significant and positive correlation between the levels of M-CSF and staphylococci was found in elderly individuals and HIV-positive patients treated with antiretroviral therapy. A significant and positive correlation between the levels of M-CSF and CD125/MUC16 was also found in both patients. These correlations were enhanced in both patients as compared with healthy subjects. Conclusion: Salivary M-CSF might be useful as a new indicator of opportunistic infection caused by staphylococci and a defense against infection in immunocompromised hosts.
Image-Based Artificial Intelligence Technology for Diagnosing Middle Ear Diseases: A Systematic Review
Authors: Song Dahye , Kim Taewan , Lee Yeonjoon , Kim Jaeyoung
Published: September 2023

Otolaryngological diagnoses, such as otitis media, are traditionally performed using endoscopy, wherein diagnostic accuracy can be subjective and vary among clinicians. The integration of objective tools, like artificial intelligence (AI), could potentially improve the diagnostic process by minimizing the influence of subjective biases and variability. We systematically reviewed the AI techniques using medical imaging in otolaryngology. Relevant studies related to AI-assisted otitis media diagnosis were extracted from five databases: Google Scholar, PubMed, Medline, Embase, and IEEE Xplore, without date restrictions. Publications that did not relate to AI and otitis media diagnosis or did not utilize medical imaging were excluded. Of the 32identified studies, 26 used tympanic membrane images for classification, achieving an average diagnosis accuracy of 86% (range: 48.7–99.16%). Another three studies employed both segmentation and classification techniques, reporting an average diagnosis accuracy of 90.8% (range: 88.06–93.9%). These findings suggest that AI technologies hold promise for improving otitis media diagnosis, offering benefits for telemedicine and primary care settings due to their high diagnostic accuracy. However, to ensure patient safety and optimal outcomes, further improvements in diagnostic performance are necessary.
Ethiopian Bamboo Fiber Aging Process and Reinforcement: Advancing Mechanical Properties of Bamboo Fiber-Epoxy Composites for Automobile Applications
Authors: Dessalegn Yalew , Singh Balkeshwar , Safayo Barisso Bino , Jameel Mohammed , Hossain Nazia , Rashedi Ahmad , Ahmed Gulam Mohammed Sayeed
Published: September 2023

The purpose of this paper is to evaluate the properties of Ethiopian bamboo fibre polymer composites as headliners in the automobile industry. Bamboo fibres are developed using the roll milling technique, and bamboo fibre epoxy composites (BFEPCS) are developed using a compression mould and a hot press machine. The mechanical properties are measured based on the recommended procedure of the ASTM. In total, 40% of the volume fraction of fibres is used to produce polymer composites. An accurate evaluation of its mechanical properties is thus critical for predicting its behaviour during a vehicle’s interior impact assessment. Conventional headliner materials are heavier, non-biodegradable, expensive, and non-sustainable during processing compared to the currently researched materials. Three representatives of bamboo plants are harvested in three regions of bamboo species, three groups of ages, and two harvesting months. Two-year-old bamboo fibres have the highest mechanical properties of all ages, and November has a higher mechanical properties compared to February. Inji-bara and Kom-bolcha have the highest and lowest mechanical properties, respectively. BFEPCs have high mechanical properties compared to BFPPCs. The mechanical properties of the current research findings have higher measured values compared to Jute felt PU, CFPU, GFMPU, BFPP, BFEP, PP foam, and TPU. The flexural strength of BFPCs has higher properties compared to their tensile strength. Ethiopian bamboo fibres and their polymer composites have the best mechanical properties for the composite industry, which is used for headliner materials in the automobile industry, compared to conventional headliner materials.
Research on the Current Application Status of Magnesium Metal Stents in Human Luminal Cavities
Authors: Chen Xiang , Xia Yan , Shen Sheng , Wang Chunyan , Zan Rui , Yu Han , Yang Shi , Zheng Xiaohong , Yang Jiankang , Suo Tao , Gu Yaqi , Zhang Xiaonong
Published: September 2023

The human body comprises various tubular structures that have essential functions in different bodily systems. These structures are responsible for transporting food, liquids, waste, and other substances throughout the body. However, factors such as inflammation, tumors, stones, infections, or the accumulation of substances can lead to the narrowing or blockage of these tubular structures, which can impair the normal function of the corresponding organs or tissues. To address luminal obstructions, stenting is a commonly used treatment. However, to minimize complications associated with the long-term implantation of permanent stents, there is an increasing demand for biodegradable stents (BDS). Magnesium (Mg) metal is an exceptional choice for creating BDS due to its degradability, good mechanical properties, and biocompatibility. Currently, the Magmaris® coronary stents and UNITY-BTM biliary stent have obtained Conformité Européene (CE) certification. Moreover, there are several other types of stents undergoing research and development as well as clinical trials. In this review, we discuss the required degradation cycle and the specific properties (anti-inflammatory effect, antibacterial effect, etc.) of BDS in different lumen areas based on the biocompatibility and degradability of currently available magnesium-based scaffolds. We also offer potential insights into the future development of BDS.
Insights on the Extreme Storm Surge Event of the 22 November 2022 in the Venice Lagoon
Authors: Mel Riccardo Alvise , Coraci Elisa , Morucci Sara , Crosato Franco , Cornello Michele , Casaioli Marco , Mariani Stefano , Carniello Luca , Papa Alvise , Bonometto Andrea , Ferla Maurizio
Published: September 2023

The Italian Institute for Environmental Protection and Research (ISPRA) manages the national sea state real time monitoring system for Italy, which consists of the National Sea Level Network (RMN), the North Adriatic and Venice Lagoon Sea Level Network (RMLV), the National Wave Networks (RON), and a marine weather forecasting system. These systems are particularly deployed to monitor and predict storm surges that affect the northern part of the Adriatic Sea and the Venice Lagoon, usually causing damages and morphological impacts over the highly anthropized coastal areas. On 22 November 2022, an extreme storm surge event occurred in the northern Adriatic Sea, producing severe damages on its coastline. Venice and the surrounding urban settlements have been protected from flooding thanks to the operation of the Mo.S.E. (Modulo Sperimentale Elettromeccanico) system, a set of artificial barriers built to isolate the lagoon from the sea in case of extreme high tides. Coastal flooding prevention measures, such as storm-surge barriers, are indeed being widely adopted globally because of the accelerating rise in sea levels. An analysis of this extreme event is presented here to highlight the functionality and the usefulness of the ISPRA sea state monitoring system. In particular, the analysis of the as-if scenario reproducing the natural tide propagation within the lagoon, neglecting the operation of the Mo.S.E. system, can only be pursued by using hydrodynamic models forced using extensive observed data. Results highlight that the “not-regulated” sea level would have exceeded 200 cm above the reference datum at Chioggia, a threshold never recorded in the Venice Lagoon since sea level monitoring systems have been operational.
Environmental Assessment with Cage Exposure in the Neva Estuary, Baltic Sea: Metal Bioaccumulation and Physiologic Activity of Bivalve Molluscs
Authors: Berezina Nadezhda , Maximov Alexey , Sharov Andrey , Gubelit Yulia , Kholodkevich Sergei
Published: September 2023

The rise in anthropogenic impacts on the marine environment requires new water management. The use of a triadic approach (bioaccumulation, bioassay, and physiological biomarkers) has been shown to have good applicability for the comparative assessment of the environmental state of the Neva Estuary (Gulf of Finland, Baltic Sea). The novelty of the methodological approach of the study was that it involved both active and passive bio-monitoring methods for assessing the quality of estuarine environment. The classical analyses of metal concentration in bottom sediments, in field biota (fish and molluscs), and in caged molluscs were accompanied by a bioassay of sediment toxicity using amphipods. The physiological state of molluscs kept in cages was assessed according to two functional characteristics, such as cardio-tolerance and metabolic activity (oxygen consumption rate), after exposition in cages. The method of active monitoring (caging exposure with molluscs) as a measurement of parameters in clean molluscs has proven itself well in controlling the accumulation of both metals and oil products. Macroalgae that are abundant in estuarine ecosystems are also good indicators of metals, at least showing the transition from bottom sediments to the next level of food webs. Unionid molluscs were found to be a more sensitive and effective indicator of contaminant accumulation than dreissenid molluscs, characterized by a low tolerance to changeable environmental conditions in the estuarine ecosystem and rather high mortality in cages. Our results have shown that caging exposure with unionids can be a widely used methodological approach for the assessment of estuarine environmental quality through the determination of metal concentrations in molluscs and their physiological state.
On the Added Modal Coefficients of a Rotating Submerged Cylinder Induced by a Whirling Motion—Part 1: Experimental Investigation
Authors: Roig Rafel , Sánchez-Botello Xavier , Jou Esteve , Escaler Xavier
Published: September 2023

The operation of submerged rotating machines, such as marine current or tidal turbines, can present deleterious fluid phenomena that may provoke extreme structural vibrations. To predict their dynamic responses, it is necessary to know the added modal coefficients of their runners under a whirling motion. For that purpose, a bespoke test rig was designed to investigate the added modal coefficients of a submerged cylinder, which could rotate at different speeds both in air and completely submerged in water inside a cylindrical tank. First, the modes of vibration were experimentally measured by exciting the cylinder with a push-release method during steady tests or with ramps in rotating speed during transient tests. The calculated natural frequencies and damping ratios were then used in a mathematical model of the dynamic system to calculate the added modal coefficients. During steady tests, the natural frequencies and damping ratios of the whirling modes changed significantly as a function of the rotating speed. Additionally, a whirling mode was observed to change its direction at a given rotating speed. During transient tests, rotating speed ramps with high accelerations were found to present lower lock-in amplitude and frequencies. Moreover, fast downward ramps presented lock-in amplitudes four times higher than fast upward ramps. Consequently, the added modal coefficients changed accordingly as a function of the rotating speed, ramp acceleration, and ramp direction. For these reasons, it was confirmed that the modal responses of submerged rotating bodies must be calculated for each operational rotating speed, even at low velocities, and for each transient event in order to precisely predict their vibration behaviors.
Characterizing the Variability of a Physical Driver of North Atlantic Right Whale Foraging Habitat Using Altimetric Indices
Authors: Tao Jing , Shen Hui , Danielson Richard E. , Perrie William
Published: September 2023

Physical ocean circulation features, especially the Gaspé Current (GC) intrusion, influence the transport and aggregation of whale prey, thereby influencing the whale foraging habitat in the Gulf of St. Lawrence (GSL), Canada. We employ satellite altimetry-derived sea level anomaly (SLA) indices to monitor interannual variations in the intensity of the GC in the North Atlantic Right Whale (Eubalaena glacialis; NARW) habitat in the GSL. Measurements of surface slope and volume transport are taken from the SLA profiles along a repeating ground track of the Jason-2/3 satellites. These are employed as complementary proxies in characterizations of physical processes in the GSL. The relationship between altimetric indices and indices of zooplankton abundance are explored in the southern GSL. Results demonstrate that an altimetric index estimated from surface slope (Indexslope−half) is correlated with river discharge of the St. Lawrence River and can be utilized to infer variations in GC intensities. Time series of the altimetric indices during 2009–2021 are found to exhibit interannual and seasonal environmental variability, which influence transport into the southern GSL. As captured by the altimetric indices, these features of the surface ocean circulation can be linked to zooplankton variations in the Shediac Valley, where NARWs are frequently observed. Therefore, in linking physical drivers of ocean dynamics to the NARW foraging habitat, variations in these indices can also potentially help describe some features of the distribution patterns of NARW sightings in this area.
Recent Advances in the Biosynthesis of Natural Sugar Substitutes in Yeast
Authors: Li Jian , Li Honghao , Liu Huayi , Luo Yunzi
Published: September 2023

Natural sugar substitutes are safe, stable, and nearly calorie-free. Thus, they are gradually replacing the traditional high-calorie and artificial sweeteners in the food industry. Currently, the majority of natural sugar substitutes are extracted from plants, which often requires high levels of energy and causes environmental pollution. Recently, biosynthesis via engineered microbial cell factories has emerged as a green alternative for producing natural sugar substitutes. In this review, recent advances in the biosynthesis of natural sugar substitutes in yeasts are summarized. The metabolic engineering approaches reported for the biosynthesis of oligosaccharides, sugar alcohols, glycosides, and rare monosaccharides in various yeast strains are described. Meanwhile, some unresolved challenges in the bioproduction of natural sugar substitutes in yeast are discussed to offer guidance for future engineering.
Ecological Barriers for an Amphibian Pathogen: A Narrow Ecological Niche for Batrachochytrium salamandrivorans in an Asian Chytrid Hotspot
Authors: Sun Dan , Ellepola Gajaba , Herath Jayampathi , Meegaskumbura Madhava
Published: September 2023

The chytrid fungal pathogens Batrachochytrium salamandrivorans (Bsal) and B. dendrobatidis (Bd) are driving amphibian extinctions and population declines worldwide. As their origins are believed to be in East/Southeast Asia, this region is crucial for understanding their ecology. However, Bsal screening is relatively limited in this region, particularly in hotspots where Bd lineage diversity is high. To address this gap, we conducted an extensive Bsal screening involving 1101 individuals from 36 amphibian species, spanning 17 natural locations and four captive facilities in the biodiversity-rich Guangxi Zhuang Autonomous Region (GAR). Our PCR assays yielded unexpected results, revealing the complete absence of Bsal in all tested samples including 51 individuals with Bd presence. To understand the potential distribution of Bsal, we created niche models, utilizing existing occurrence records from both Asia and Europe. These models estimated potential suitable habitats for Bsal largely in the northern and southwestern parts of the GAR. Although Bsal was absent in our samples, the niche models identified 10 study sites as being potentially suitable for this pathogen. Interestingly, out of these 10 sites, Bd was detected at 8. This suggests that Bsal and Bd could possibly co-exist in these habitats, if Bsal were present. Several factors seem to influence the distribution of Bsal in Asia, including variations in temperature, local caudate species diversity, elevation, and human population density. However, it is climate-related factors that hold the greatest significance, accounting for a notable 60% contribution. The models propose that the specific climatic conditions of arid regions, primarily seen in the GAR, play a major role in the distribution of Bsal. Considering the increased pathogenicity of Bsal at stable and cooler temperatures (10–15 °C), species-dependent variations, and the potential for seasonal Bd-Bsal interactions, we emphasize the importance of periodic monitoring for Bsal within its projected range in the GAR. Our study provides deeper insights into Bsal’s ecological niche and the knowledge generated will facilitate conservation efforts in amphibian populations devastated by chytrid pathogens across other regions of the world.
Determinants of Repurchase Size: Evidence from the UK
Authors: Sodhi Adhiraj , Mateus Cesario , Mateus Irina , Stojanovic Aleksandar
Published: September 2023

The paper focuses on the factors that determine the size of an open market share repurchase in the UK. The testing covers the time period 1985–2014 and tests if the traditional motives for repurchasing shares also determine the size of the repurchase. The testing also checks if the influences of these determinants are non-linear, U-shaped or inverted U-shaped, which, to the best of our knowledge, is also a novel empirical approach. The consideration of non-linear influences on repurchase size is relevant due to the overlapping of repurchase determinants. For instance, if the distribution of excess cash is the motive for undertaking the repurchase and not replacing dividend distribution, then the influence of dividend distribution on repurchase size may conflict with the traditional expectation of repurchases being used as dividend replacements. The testing finds that the motive of using repurchases for signalling stock undervaluation has the most consistent influence on repurchase size, followed by the motives of adjusting the reported EPS when earnings are negative and for distributing surplus cash. The motive for using repurchases to adjust the capital structure to increase the debt exposure has a U-shaped influence on repurchase size, while board independence has an inverted U-shaped influence. Overall, when compared to the current literature, this paper is able to demonstrate that there is a strong consistency between the motives that lead to repurchases in the UK, and the determinants of repurchase size.
Antimicrobial Peptides: The Production of Novel Peptide-Based Therapeutics in Plant Systems
Authors: Tiwari Pragya , Srivastava Yashdeep , Sharma Abhishek , Vinayagam Ramachandran
Published: September 2023

The increased prevalence of antibiotic resistance is alarming and has a significant impact on the economies of emerging and underdeveloped nations. The redundancy of antibiotic discovery platforms (ADPs) and injudicious use of conventional antibiotics has severely impacted millions, across the globe. Potent antimicrobials from biological sources have been extensively explored as a ray of hope to counter the growing menace of antibiotic resistance in the population. Antimicrobial peptides (AMPs) are gaining momentum as powerful antimicrobial therapies to combat drug-resistant bacterial strains. The tremendous therapeutic potential of natural and synthesized AMPs as novel and potent antimicrobials is highlighted by their unique mode of action, as exemplified by multiple research initiatives. Recent advances and developments in antimicrobial discovery and research have increased our understanding of the structure, characteristics, and function of AMPs; nevertheless, knowledge gaps still need to be addressed before these therapeutic options can be fully exploited. This thematic article provides a comprehensive insight into the potential of AMPs as potent arsenals to counter drug-resistant pathogens, a historical overview and recent advances, and their efficient production in plants, defining novel upcoming trends in drug discovery and research. The advances in synthetic biology and plant-based expression systems for AMP production have defined new paradigms in the efficient production of potent antimicrobials in plant systems, a prospective approach to countering drug-resistant pathogens.
Expanded Vermiculite/D-Mannitol as Shape-Stable Phase Change Material for Medium Temperature Heat Storage
Authors: Lv Xifeng , Fan Chaoqun , Han Ying , Tang Xiaojin , Zhang Changwei , Cai Di , Chen Huidong
Published: September 2023

Aiming to promote the application of D-mannitol in the field of phase change thermal storage, obstacles, including low thermal storage efficiency and high supercooling, should be properly disposed of. The adoption of adaptable and low-cost supporting materials to make shape-stable phase change materials (ss-PCMs) affordable is a primary solution to solve the above shortcomings. In this study, high-performance ss-PCM for effective medium-temperature heat storage was prepared using expanded vermiculite as the support for D-mannitol preservation. Among the three candidates that treated the raw vermiculite by dilute acid, calcination, and microwave heating, the calcinated expanded vermiculite (CV) was characterized as the most suitable one. After impregnating D-mannitol into the CV carrier by vacuum, a melting enthalpy of 205.1 J/g and a crystallization enthalpy of 174.1 J/g were achieved by the as-received CV/D-mannitol ss-PCM. Additionally, the supercooling of the ss-PCM was reduced to 45.6 °C. The novel CV/D-mannitol ss-PCM also exhibited excellent reusability and stability. All the findings indicate that the abundant and inexpensive CV exhibited great potential as the supporting material for D-mannitol-based ss-PCMs, which allow effective waste heat recovery and temperature regulation.
The Development of a High-Strength Mg-10.3Gd-4.4Y-0.9Zn-0.7Mn Alloy Subjected to Large Differential-Thermal Extrusion and Isothermal Aging
Authors: Wang Kui , Wang Xinwei , Wang Jinxing , Dang Cong , Dou Xiaoxu , Huang Song , Liu Manping , Wang Jingfeng
Published: September 2023

The large differential-thermal extrusion (LDTE) process, a novel approach for efficiently fabricating a high-strength Mg-10.3Gd-4.4Y-0.9Zn-0.7Mn (wt.%) alloy, is introduced in this work. Unlike typical isothermal extrusion processes, where the ingot and die temperatures are kept the same, LDTE involves significantly higher ingot temperatures (~120 °C) compared to the die temperature. For high-strength Mg-RE alloys, the maximum isothermal extrusion ram speed is normally limited to 1 mm/s. This research uses the LDTE process to significantly increase the ram speed to 2.0 mm/s. The LPTE-processed alloy possesses a phase composition that is similar to that of isothermal extruded alloys, including α-Mg, 14H-type long-period stacking ordered (LPSO) and β-Mg5(Gd, Y) phases. The weakly preferentially oriented α-Mg grains in the LDTE-processed alloy have <101¯0>Mg//ED fibrous and <0001>Mg//ED anomalous textures as their two main constituents. After isothermal aging, high quantitative densities of prismatic β′ and basal γ′ precipitates are produced, which have the beneficial effect of precipitation hardening. With a yield tensile strength of 344 MPa, an ultimate tensile strength of 488 MPa, and an elongation of 9.7%, the alloy produced by the LDTE process exhibits an exceptional strength–ductility balance, further demonstrating the potential of this method for efficiently producing high-strength Mg alloys.
Characterizing q-Bessel Functions of the First Kind with Their New Summation and Integral Representations
Authors: Fadel Mohammed , Raza Nusrat , Du Wei-Shih
Published: September 2023

As a powerful tool for models of quantum computing, q-calculus has drawn the attention of many researchers in the discipline of special functions. In this paper, we present new properties and characterize q-Bessel functions of the first kind using some identities of q-calculus. The results presented in this article help us to obtain new expression results related to q-special functions. New summation and integral representations for q-Bessel functions of the first kind are also established. A few examples are also provided to demonstrate the effectiveness of the proposed strategy.
Joint Low-Light Image Enhancement and Denoising via a New Retinex-Based Decomposition Model
Authors: Zhao Chenping , Yue Wenlong , Xu Jianlou , Chen Huazhu
Published: September 2023

It is well known that images taken in low-light conditions frequently suffer from unknown noise and low visibility, which can pose challenges for image enhancement. The majority of Retinex-based decomposition algorithms usually attempt to directly design prior regularization for illumination or reflectance. Nevertheless, noise can be involved in such schemes. To address these issues, a new Retinex-based decomposition model for simultaneous enhancement and denoising has been developed. In this paper, an extended decomposition scheme is introduced to extract the illumination and reflectance components, which helps to better describe the prior information on illumination and reflectance. Subsequently, spatially adaptive weights are designed for two regularization terms. The main motivation is to provide a small amount of smoothing in near edges or bright areas and stronger smoothing in dark areas, which could preserve useful information and remove noise effectively during image-enhancement processing. Finally, the proposed algorithm is validated on several common datasets: LIME, LOL, and NPE. Extensive experiments show that the presented method is superior to state-of-the-art methods both in objective index comparisons and visual quality.
UWB and MB-OFDM for Lunar Rover Navigation and Communication
Authors: de Curtò J. , de Zarzà I. , Calafate Carlos T.
Published: September 2023

This paper presents a comprehensive study of ultra-wideband (UWB) and multi-band orthogonal frequency-division multiplexing (MB-OFDM) technologies for lunar rover navigation and communication in challenging terrains. Lunar missions pose unique challenges, such as signal propagation in the lunar environment, terrain elevation, and rover movement constraints. To address these challenges, we propose a hybrid communication and navigation system that leverages UWB technology for high-precision positioning and MB-OFDM for robust and high-throughput communication. We develop a realistic simulation framework that incorporates terrain elevation, obstacles, and rover movement constraints, along with a simple fading model for communication. Simulation results demonstrate the effectiveness of the proposed system in navigating lunar rovers to their target locations while maintaining reliable communication links with a lunar lander. A novel approach based on game theory for rover navigation is also presented. The study provides valuable insights into the design and optimization of communication and navigation systems for future lunar missions, paving the way for seamless integration of advanced terrestrial technologies in extraterrestrial environments.
Survival Analysis of a Predator–Prey Model with Seasonal Migration of Prey Populations between Breeding and Non-Breeding Regions
Authors: Dai Xiangjun , Jiao Hui , Jiao Jianjun , Quan Qi
Published: September 2023

In this paper, we establish and study a novel predator–prey model that incorporates: (i) the migration of prey between breeding and non-breeding regions; (ii) the refuge effect of prey; and (iii) the reduction in prey pulse birth rate, in the form of a fear effect, in the presence of predators. Applying the Floquet theory and the comparison theorem of impulsive differential equations, we obtain the sufficient conditions for the stability of the prey-extinction periodic solution and the permanence of the system. Furthermore, we also study the case where the prey population does not migrate. Sufficient conditions for the stability of the prey-extinction periodic solution and the permanence are also established, and the threshold for extinction and permanence of the prey population is obtained. Finally, some numerical simulations are provided to verify the theoretical results. These results provide a theoretical foundation for the conservation of biodiversity.
Transport Object Detection in Street View Imagery Using Decomposed Convolutional Neural Networks
Authors: Bai Yunpeng , Shang Changjing , Li Ying , Shen Liang , Jin Shangzhu , Shen Qiang
Published: September 2023

Deep learning has achieved great successes in performing many visual recognition tasks, including object detection. Nevertheless, existing deep networks are computationally expensive and memory intensive, hindering their deployment in resource-constrained environments, such as mobile or embedded devices that are widely used by city travellers. Recently, estimating city-level travel patterns using street imagery has been shown to be a potentially valid way according to a case study with Google Street View (GSV), addressing a critical challenge in transport object detection. This paper presents a compressed deep network using tensor decomposition to detect transport objects in GSV images, which is sustainable and eco-friendly. In particular, a new dataset named Transport Mode Share-Tokyo (TMS-Tokyo) is created to serve the public for transport object detection. This is based on the selection and filtering of 32,555 acquired images that involve 50,827 visible transport objects (including cars, pedestrians, buses, trucks, motors, vans, cyclists and parked bicycles) from the GSV imagery of Tokyo. Then a compressed convolutional neural network (termed SVDet) is proposed for street view object detection via tensor train decomposition on a given baseline detector. The method proposed herein yields a mean average precision (mAP) of 77.6% on the newly introduced dataset, TMS-Tokyo, necessitating just 17.29 M parameters and a computational capacity of 16.52 G FLOPs. As such, it markedly surpasses the performance of existing state-of-the-art methods documented in the literature.