bluuebunny/crossref_metadata_2025 huggingface dataset:
Cardiac Conduction Velocity, Remodeling and Arrhythmogenesis
Authors: Han Bo , Trew Mark L. , Zgierski-Johnston Callum M.
Published: October 2021

Cardiac electrophysiological disorders, in particular arrhythmias, are a key cause of morbidity and mortality throughout the world. There are two basic requirements for arrhythmogenesis: an underlying substrate and a trigger. Altered conduction velocity (CV) provides a key substrate for arrhythmogenesis, with slowed CV increasing the probability of re-entrant arrhythmias by reducing the length scale over which re-entry can occur. In this review, we examine methods to measure cardiac CV in vivo and ex vivo, discuss underlying determinants of CV, and address how pathological variations alter CV, potentially increasing arrhythmogenic risk. Finally, we will highlight future directions both for methodologies to measure CV and for possible treatments to restore normal CV.
The Multiple Interactions of RUNX with the Hippo–YAP Pathway
Authors: Chuang Linda , Ito Yoshiaki
Published: October 2021

The Hippo–YAP signaling pathway serves roles in cell proliferation, stem cell renewal/maintenance, differentiation and apoptosis. Many of its functions are central to early development, adult tissue repair/regeneration and not surprisingly, tumorigenesis and metastasis. The Hippo pathway represses the activity of YAP and paralog TAZ by modulating cell proliferation and promoting differentiation to maintain tissue homeostasis and proper organ size. Similarly, master regulators of development RUNX transcription factors have been shown to play critical roles in proliferation, differentiation, apoptosis and cell fate determination. In this review, we discuss the multiple interactions of RUNX with the Hippo–YAP pathway, their shared collaborators in Wnt, TGFβ, MYC and RB pathways, and their overlapping functions in development and tumorigenesis.
Evaluation of Immunomodulatory Responses and Changed Wound Healing in Type 2 Diabetes—A Study Exploiting Dermal Fibroblasts from Diabetic and Non-Diabetic Human Donors
Authors: Nickel Kimberly , Wensorra Ursula , Wenck Horst , Peters Nils , Genth Harald
Published: October 2021

The dermis is the connective layer between the epidermis and subcutis and harbours nerve endings, glands, blood vessels, and hair follicles. The most abundant cell type is the fibroblast. Dermal fibroblasts have a versatile portfolio of functions within the dermis that correspond with different types of cells by either direct contact or by autocrine and paracrine signalling. Diabetic skin is characterized by itching, numbness, ulcers, eczema, and other pathophysiological changes. These pathogenic phenotypes have been associated with the effects of the reactive glucose metabolite methylglyoxal (MGO) on dermal cells. In this study, dermal fibroblasts were isolated from diabetic and non-diabetic human donors. Cultured dermal fibroblasts from diabetic donors exhibited reduced insulin-induced glucose uptake and reduced expression of the insulin receptor. This diabetic phenotype persists under cell culture conditions. Secretion of IL-6 was increased in fibroblasts from diabetic donors. Increased secretion of IL-6 and MIF was also observed upon the treatment of dermal fibroblasts with MGO, suggesting that MGO is sufficient for triggering these immunomodulatory responses. Remarkably, MIF treatment resulted in decreased activity of MGO-detoxifying glyoxalase-1. Given that reduced glyoxalase activity results in increased MGO levels, these findings suggested a positive-feedback loop for MGO generation, in which MIF, evoked by MGO, in turn blocks MGO-degrading glyoxalase activity. Finally, secretion of procollagen Type I C-Peptide (PICP), a marker of collagen production, was reduced in fibroblast from diabetic donors. Remarkably, treatment of fibroblasts with either MGO or MIF was sufficient for inducing reduced PICP levels. The observations of this study unravel a signalling network in human dermal fibroblasts with the metabolite MGO being sufficient for inflammation and delayed wound healing, hallmarks of T2D.
Roles of Exosomes in Cardiac Fibroblast Activation and Fibrosis
Authors: Hohn Julia , Tan Wenbin , Carver Amanda , Barrett Hayden , Carver Wayne
Published: October 2021

Alterations in the accumulation and composition of the extracellular matrix are part of the normal tissue repair process. During fibrosis, this process becomes dysregulated and excessive extracellular matrix alters the biomechanical properties and function of tissues involved. Historically fibrosis was thought to be progressive and irreversible; however, studies suggest that fibrosis is a dynamic process whose progression can be stopped and even reversed. This realization has led to an enhanced pursuit of therapeutic agents targeting fibrosis and extracellular matrix-producing cells. In many organs, fibroblasts are the primary cells that produce the extracellular matrix. In response to diverse mechanical and biochemical stimuli, these cells are activated or transdifferentiate into specialized cells termed myofibroblasts that have an enhanced capacity to produce extracellular matrix. It is clear that interactions between diverse cells of the heart are able to modulate fibroblast activation and fibrosis. Exosomes are a form of extracellular vesicle that play an important role in intercellular communication via the cargo that they deliver to target cells. While relatively recently discovered, exosomes have been demonstrated to play important positive and negative roles in the regulation of fibroblast activation and tissue fibrosis. These roles as well as efforts to engineer exosomes as therapeutic tools will be discussed.
Combined Assessment of the Tumor–Stroma Ratio and Tumor Immune Cell Infiltrate for Immune Checkpoint Inhibitor Therapy Response Prediction in Colon Cancer
Authors: Ravensbergen Cor J. , Polack Meaghan , Roelands Jessica , Crobach Stijn , Putter Hein , Gelderblom Hans , Tollenaar Rob A. E. M. , Mesker Wilma E.
Published: October 2021

The best current biomarker strategies for predicting response to immune checkpoint inhibitor (ICI) therapy fail to account for interpatient variability in response rates. The histologic tumor–stroma ratio (TSR) quantifies intratumoral stromal content and was recently found to be predictive of response to neoadjuvant therapy in multiple cancer types. In the current work, we predicted the likelihood of ICI therapy responsivity of 335 therapy-naive colon adenocarcinoma tumors from The Cancer Genome Atlas, using bioinformatics approaches. The TSR was scored on diagnostic tissue slides, and tumor-infiltrating immune cells (TIICs) were inferred from transcriptomic data. Tumors with high stromal content demonstrated increased T regulatory cell infiltration (p = 0.014) but failed to predict ICI therapy response. Consequently, we devised a hybrid tumor microenvironment classification of four stromal categories, based on histological stromal content and transcriptomic-deconvoluted immune cell infiltration, which was associated with previously established transcriptomic and genomic biomarkers for ICI therapy response. By integrating these biomarkers, stroma-low/immune-high tumors were predicted to be most responsive to ICI therapy. The framework described here provides evidence for expansion of current histological TIIC quantification to include the TSR as a novel, easy-to-use biomarker for the prediction of ICI therapy response.
Auranofin and Cold Atmospheric Plasma Synergize to Trigger Distinct Cell Death Mechanisms and Immunogenic Responses in Glioblastoma
Authors: Van Loenhout Jinthe , Freire Boullosa Laurie , Quatannens Delphine , De Waele Jorrit , Merlin Céline , Lambrechts Hilde , Lau Ho Wa , Hermans Christophe , Lin Abraham , Lardon Filip , Peeters Marc , Bogaerts Annemie , Smits Evelien , Deben Christophe
Published: October 2021

Targeting the redox balance of malignant cells via the delivery of high oxidative stress unlocks a potential therapeutic strategy against glioblastoma (GBM). We investigated a novel reactive oxygen species (ROS)-inducing combination treatment strategy, by increasing exogenous ROS via cold atmospheric plasma and inhibiting the endogenous protective antioxidant system via auranofin (AF), a thioredoxin reductase 1 (TrxR) inhibitor. The sequential combination treatment of AF and cold atmospheric plasma-treated PBS (pPBS), or AF and direct plasma application, resulted in a synergistic response in 2D and 3D GBM cell cultures, respectively. Differences in the baseline protein levels related to the antioxidant systems explained the cell-line-dependent sensitivity towards the combination treatment. The highest decrease of TrxR activity and GSH levels was observed after combination treatment of AF and pPBS when compared to AF and pPBS monotherapies. This combination also led to the highest accumulation of intracellular ROS. We confirmed a ROS-mediated response to the combination of AF and pPBS, which was able to induce distinct cell death mechanisms. On the one hand, an increase in caspase-3/7 activity, with an increase in the proportion of annexin V positive cells, indicates the induction of apoptosis in the GBM cells. On the other hand, lipid peroxidation and inhibition of cell death through an iron chelator suggest the involvement of ferroptosis in the GBM cell lines. Both cell death mechanisms induced by the combination of AF and pPBS resulted in a significant increase in danger signals (ecto-calreticulin, ATP and HMGB1) and dendritic cell maturation, indicating a potential increase in immunogenicity, although the phagocytotic capacity of dendritic cells was inhibited by AF. In vivo, sequential combination treatment of AF and cold atmospheric plasma both reduced tumor growth kinetics and prolonged survival in GBM-bearing mice. Thus, our study provides a novel therapeutic strategy for GBM to enhance the efficacy of oxidative stress-inducing therapy through a combination of AF and cold atmospheric plasma.
Electrochemical Development of an Immunosensor for Detection Polychlorinated biphenyls (PCBs) for Environmental Analysis
Authors: Alsefri Samia , Balbaied Thanih , Moore Eric
Published: October 2021

Polychlorinated biphenyls (PCBs) are a highly toxic family of synthetic chemical compounds. PCBs are widely spread in the environment and their toxicity can cause serious ailments to living organisms such as cancer; therefore, developing a device for the detection of PCBs in the environment is significant. In this paper, polyclonal primary anti-PCB antibodies were immobilized onto a gold screen-printed electrode with the purpose of creating an electrochemical immunosensor for the detection of Aroclor 1254. It was modified with 11-mercaptoundecanoic acid (11-MUA) and the activation of the carboxylic acid terminal was performed by cross-linking 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) and N-hyrodsuccinmide (NHS) on the electrode surface. Cyclic voltammetry, electrochemical impedance spectroscopy (EIS), linear sweep voltammetry, atomic force microscopy (AFM), scanning electron microscopy (SEM), and contact angle measurement were employed to characterize SAM development on the gold electrode. Using a competitive assay, a 0.09 ng/mL−1 limit of detection and a linear range of 0.101–220 ng/mL−1 were determined. The self-assembled monolayers (SAM) were successful in encapsulating the PCBs on the immunosensor. The electrochemical detection showed better resolution when compared to traditional methods such as the ELISA optical technique. The novel electrochemical immunosensor approach that is discussed in this paper has the potential to offer rapid sample screening in a portable, disposable format and could contribute to the effective control and prevention of PCBs in the environment.
A Week in the Life: Pediatric Palliative Care through the Eyes of a Medical Student
Authors: Williams Eileen , Jarrell Jill Ann , Rubenstein Jared
Published: October 2021

To complete the curriculum, learners rotating through a pediatric palliative care service are asked to submit a piece of reflective writing. Here, we share an edited version of the narrative one student submitted, accompanied by a brief consideration of the numerous benefits of reflective writing for medical trainees (including improved communication and professionalism skills, as well as increased levels of empathy and comfort when facing complex or difficult situations). Additionally, we describe how brief personal narratives may serve to reduce common misconceptions and confusion by educating patients, families, and clinicians about the reality and the role of pediatric palliative care.
Utilization of Parallel Resources and Sociodemographic Factors in Treating Children with Complex Chronic Diseases: A Cross-Sectional Study
Authors: Pérez-Ardanaz Bibiana , Peláez-Cantero María José , González-Cano-Caballero María , Gutiérrez-Rodríguez Laura , Gómez-González Alberto José , Lupiáñez-Pérez Inmaculada , Morales-Asencio José Miguel , Canca-Sánchez José Carlos
Published: October 2021

Background: Children with complex chronic conditions have a high need for health and social care resources. Many parents explore parallel resources such as alternative therapies, associations, psychological support, private medical consultations, and other out-of-pocket expenses for healthcare. The use of these alternative health resources is sometimes unclear and may lead to health inequalities. To characterize the use made of alternative healthcare resources for children with complex chronic conditions. Additionally, we evaluate the influence of sociodemographic factors on the distribution of this utilization of resources; (2) Methods: Cross-sectional study. Children with complex chronic diseases were treated at a tertiary hospital in Granada, Spain in 2016. We analyzed their use of healthcare resources and socioeconomic variables. This research complies with STROBE guidelines for observational studies; (3) Results: In total, 265 children were analyzed (mean age 7.3 years, SD 4.63). A total of 105 children (39.6%) attended private consultations with specialists, and 12.1% (n = 32) of the children had additional private health insurance. One out three parents belonged to a mutual support association (n = 78), and 26% (n = 69) of the children used alternative therapies. Furthermore, 75.4% (n = 199) of the children received no psychological support. Children whose parents had a higher educational level and occupations status made greater use of parallel healthcare resources.; (4) Conclusions: A significant proportion of children used multiple health resources in addition to the public healthcare system depending on sociodemographic determinants. Studies are needed to determine whether the use of these alternative services achieves better levels of health.
Deposition of Super-Hydrophobic Silver Film on Copper Substrate and Evaluation of Its Corrosion Properties
Authors: Stergioudi Fani , Baxevani Aikaterini , Mavropoulos Azarias , Skordaris Georgios
Published: October 2021

A simple and versatile chemical solution deposition process is reported to manipulate the wettability properties of copper sheets. The whole process has the advantage of being time-saving low cost and environment-friendly. An adherent silver coating was achieved under optimal conditions. Scanning electron microscopy and X-ray diffraction were used to examine the silver film structure. A confocal microscope was used to record the 3D topography and assess the film roughness of the surface. A dual morphology was revealed, consisting of broad regions with feather-like structured morphologies and some areas with spherical morphologies. Such silver-coated copper samples exhibited a sufficiently stable coating with superhydrophobicity, having a maximum water contact angle of 152°, along with an oleophilic nature. The corrosion behavior of the produced hydrophobic copper under optimal conditions was evaluated by means of potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) using a 3.5% NaCl solution. The corrosion protection mechanism was elucidated by the proposed equivalent circuits, indicating that the superhydrophobic silver coating acted as an effective barrier, separating the Cu substrate from the corrosive solution. The superhydrophobic coating demonstrated enhanced anti-corrosion properties against NaCl aqueous solution in relation to the copper substrate as indicated from both EIS and potentiodynamic polarization experiments.
Investigation on Film Quality and Photophysical Properties of Narrow Bandgap Molecular Semiconductor Thin Film and Its Solar Cell Application
Authors: Li Xiaotong , Zou Xiaoping , Zhang Chunqian , Cheng Jin , Li Guangdong , Wang Yifei , Wang Xiaolan , Song Keke , Ren Baokai , Li Junming
Published: October 2021

Hexane-1,6-diammonium pentaiodobismuth (HDA-BiI5) is one of the narrowest bandgap molecular semiconductor reported in recent years. Through the study of its energy band structure, it can be identified as an N-type semiconductor and is able to absorb most of the visible light, making it suitable to fabricate solar cells. In this paper, SnO2 was used as an electron transport layer in HDA-BiI5-based solar cells, for its higher carrier mobility compared with TiO2, which is the electron transport layer used in previous researches. In addition, the dilution ratio of SnO2 solution has an effect on both the morphology and photophysical properties of HDA-BiI5 films. At the dilution ratio of SnO2:H2O = 3:8, the HDA-BiI5 film has a better morphology and is less defect inside, and the corresponding device exhibited the best photovoltaic performance.
Assessment of the Condition of Anilox Rollers
Authors: Savickas Arnas , Stonkus Rimantas , Jurkonis Eugenijus , Iljin Igor
Published: October 2021

To produce high-quality prints using flexographic printing technology, it is important, among other factors, how accurately and consistently the ink is delivered to the printing plate, and, from there, onto the printed material. This function is performed by anilox rollers. The aim of this research is to investigate the condition of anilox rollers in printing houses in the Baltic states. The study evaluated the wear and cell clogging of anilox rollers. The dependency of clogging on the cell size, as well as the dependency of wear on the cell size (i.e., change in cell volume) and quantity of doctor blades, was investigated. In addition, the uniformity of cell clogging and wear on the surface of the anilox roller was evaluated. Studies have shown that more than half of the anilox rollers in printing houses are not washed properly; higher line screen anilox rollers tend to become more clogged, and it is important to take measurements at more than three locations to assess the reliability of more worn rollers.
Salivary pH Effect on Orthodontic Appliances: In Vitro Study of the SS/DLC System
Authors: Fróis António , Evaristo Manuel , Santos Ana Cristina , Louro Cristina Santos
Published: October 2021

Stainless steels (SS) are the most-used alloys for manufacturing fixed orthodontic appliances due to their attractive set of mechanical properties, biocompatibility, and high corrosion resistance. Nevertheless, during regular orthodontic treatments–taking at least around 2 years–the intraoral environment inevitably degrades these bioalloys, releasing metallic ions into the oral cavity. In the first part of this in vitro study, the corrosion resistance of commercial SS appliances (brackets, tubes, and bands) was evaluated in Fusayama-Meyer artificial saliva at pH values of 2.3 and 6.8 over the course of 30 days. As expected, the results corroborated that salivary pH highly influences corrosion behaviour. Released Ni, Cr, and Fe were within dietary intake values. In the second part, a novel approach for oral corrosion prevention based on the chemical inertness of DLC materials is presented. SS surfaces were functionalized with biocompatible a-C:H-sputtered coatings and submitted to the same experimental conditions. The anticorrosion ability of this system was demonstrated, preventing the pitting corrosion that occurred on the SS substrates. Despite the galvanic coupling effect due to the presence of the Cr-based interlayer, this study enhanced the potential use of the reactive sputter-deposited a-C:H coatings in orthodontics.
Ion Sensitive GO-Si Based Metal-Semiconductor Junction Resistor Gas Sensor
Authors: Zhao Yi , Zhao Deyin , Ma Zhenzhen , Li Gong , Zhao Dan , Li Xin
Published: October 2021

Gas sensor based on the Ultraviolet and Ozone (UVO) treated Chemical Vapor Deposition (CVD) Graphene Oxide (GO) and the Ion Sensitive GO-Si based metal-semiconductor junction resistor was designed and realized. Under different gate voltages, the response characteristics of the sensor to ammonia concentration, as well as the selectivity and stability of the sensor were studied. The test results show that the comprehensive performance of the gas sensor is the best when the UVO processing time is 1 min and the applied gate voltage is −9 V. The proposed Ion Sensitive GO-Si based metal-semiconductor junction resistor Gas Sensor can detect 250 ppb ammonia with a sensitivity of 4%. The detection limit of the sensor is 50 ppb. Using acetone and ethanol as contrast gases, the sensor shows better selectivity for ammonia. The sensitivity retention rate of the sensor after 10 days is higher than 70%, which indicates that the sensor has a good retention performance.
Effect of the Post-Deposition Thermal Treatment on the Mechanical Properties of a Compositionally Modulated CrAlSiN-AlSiN Coating
Authors: Kolaklieva Lilyana , Kakanakov Roumen , Kovacheva Daniela , Chitanov Vasiliy , Cholakova Tetyana , Bahchedjiev Christo , Kolchev Stefan
Published: October 2021

A CrAlSiN-AlSiN coating with periodically modulated composition was investigated regarding dependence of the mechanical properties and toughness, morphology, composition, and structure on thermal treatment in the interval of 600–900 °C in argon ambience. The coating exhibited superhardness and high toughness up to 800 °C. A very slight decrease in the nanohardness, resistance to elastic strain to failure, and plastic deformation were observed. The coating had enhanced elastic recovery stable up to 700 °C. It was found that the coating morphology was not substantially influenced by the thermal treatment. X-ray diffraction (XRD) analysis revealed that the modulated coating had a nanocomposite structure, which did not change after annealing, even at 900 °C. The grains were composed mainly of fcc-CrN and h-AlN phases embedded into an amorphous Si3N4 matrix. A small amount of an h-Cr2N phase appeared after heating at temperatures above 700 °C. The coating composition was examined by energy-dispersive X-ray spectroscopy (EDS). The coating was stoichiometric up to 800 °C. It became sub-stoichiometric with respect to nitrogen after annealing at 800 °C and 900 °C. It is thus concluded that the CrAlSiN-AlSiN coating with a periodically modulated structure keeps the combination of superhardness (45.3 GPa) and improved toughness (H3/E*2 = 0.362 GPa, elastic recovery 57%) at temperatures up to 800 °C, and is suitable for high thermal applications.
Exploring the Utility of Diffusing Wave Spectroscopy (DWS) as a Novel Tool for Early Detection of Stability Issues in Cosmetic Emulsions
Authors: Kolman Mackenzie , Boland Gregory , Amin Samiul
Published: October 2021

In the current cosmetic and personal care industry, it is of great importance to have a technique that detects instabilities quickly and effectively, as consumers are demanding more innovative and sustainable ingredients. Diffusing wave spectroscopy (DWS) is a potential solution as it is a modern optical technique that can measure the spatial movement of particles or droplets in an emulsion—i.e., the mean square displacement (MSD), as a function of time. In the current investigation, systematic visual and diffusion behavior emulsion stability studies over a 3-h period on jojoba and avocado oil emulsions containing varying equal percentages of cocamidopropyl betaine (CAPB) and sodium lauryl ether sulfate (SLES) were conducted. The turbid emulsions studied had differing stabilities with unknown instability mechanisms to further explore if diffusing wave spectroscopy can offer a fast and early identification of problem cosmetic formulations. It was observed that, for emulsions displaying instability from 4 to 123 h, the greater the change in the MSD values over a 3-h period, the greater the instability of the emulsion. For all systems, the MSD values lowered and shifted to the right from hour 0 to hour 3. We conjecture that the emulsion droplets began to aggregate, potentially growing and giving rise to larger particles. The increasing particle size was the cause for the slowing down of the dynamics and thus diffusion, giving rise to the lowering of the MSD values. Our findings indicate that by testing an emulsion over a 3-h period, it is possible to determine whether it will be a problem formulation using DWS. Studies into this technology should be continued on a wider range of emulsions with known instability mechanisms to further our understanding of using DWS as a vital emulsion instability detector.
Characterization and Mechanism of a New Superhydrophobic Deicing Coating Used for Road Pavement
Authors: Huang Kaijian , Liu Jiajia , Wang Jiaqing , Shi Xijun
Published: October 2021

Owing to its high efficiency and low environmental impact, superhydrophobic deicing coating material has a bright future for application on road pavements. In this paper, a heterogeneous nucleation ice crystal growth model is proposed, with particular focus on the effect of surface roughness and the contact angle. The ice suppression mechanism of superhydrophobic materials is determined by this model and experimentally verified. The experimental results of the water contact angle and anti-skid tests illustrated that the prepared TiO2–octadecanoic acid coating material has a contact angle greater than 150° and good skid resistance. The freezing test confirms that the applied coating on the surface can effectively delay the crystallization of water droplets and maintain the waterdrop’s semi-spherical shape after freezing. The microstructure observation demonstrates the TiO2–octadecanoic acid material has a good micro-nano mastoid structure. Consequently, the proposed coating materials could possibly be utilized for effectively enhancing the deicing performance of pavements.
Analytical Study of Powder Stream Geometry in Laser-Based Direct Energy Deposition Process with a Continuous Coaxial Nozzle
Authors: Liu Qipeng , Yang Kun , Gao Yuehua , Liu Fencheng , Huang Chunping , Ke Liming
Published: October 2021

In the process of laser-based direct energy deposition, the particle concentration distribution and geometric characteristics of powder flow play an important role in laser–powder interaction and powder utilization, and they affect the forming quality and accuracy. In the current study, based on the geometry information of a powder nozzle and the divergence angles of a powder jet at the nozzle outlet, the geometric profile of a powder stream is analyzed. A set of formulas for calculating the geometric characteristics of the powder stream is derived based on an analytic geometry method. The influence of each parameter on the geometric characteristics of the powder stream is further studied using single-factor and sensitivity analyses. Validation is performed by comparing the results from the presented analytical expressions with those from experiments and/or simulations in published papers. The analytical formulas provided in this paper are simple and practical, providing a theoretical foundation for the control of powder flow and related processes in the forming process.
Study on Mechanical Properties and Pore Structure of Hybrid Fiber Reinforced Rubber Concrete
Authors: Liu Yushan , Pang Jianyong , Chen Qiaoqiao , Yao Weijing
Published: October 2021

In this work, to reduce the probability of brittle failure in the support structure of deeply buried high-stress soft rock roadways, hybrid-fiber reinforced rubber concrete (HFRRC) was investigated using the orthogonal test, and the effects of various factors on the performance were studied. The mechanical properties, pore structure, and microstructure of rubber concrete reinforced by basalt fiber (BF) and polyvinyl alcohol fiber (PF) were studied from macroscale, mesoscale, and microscale perspectives. The results revealed that the content of the rubber particles has a significant impact on strength. Further, the addition of the hybrid fibers to the concrete was found to have a positive effect on the splitting tensile strength and the flexural strength. However, no significant effect was observed on the compressive strength. Furthermore, it was found that the content of BF and PF have a significant impact on the energy dissipation capacity and ductility, and the influence of the PF content is greater than that of the BF content. The concrete with 10% rubber particles of 1–3 mm, a volume fraction 0.3% basalt fiber, and a volume fraction 0.2% polyvinyl alcohol fiber was obtained as the optimal mix proportions. Moreover, it was found that the random distribution of the rubber particles and the hybrid fibers optimized the pore structure, inhibited the expansion of the cracks, and reduced the brittleness of the concrete. The findings of this study can provide a useful reference for the application of an environmentally friendly material with recycled rubber aggregate and hybrid fiber.
Investigation of Micromorphology and Carrier Recombination Dynamics for InGaN/GaN Multi-Quantum Dots Grown by Molecular Beam Epitaxy
Authors: Zhang Xue , Yang Wenxian , Xing Zhiwei , Qiu Haibing , Gu Ying , Bian Lifeng , Lu Shulong , Qin Hua , Cai Yong , Suzuki Yuta , Kaneko Sakuya , Matsuda Yuki , Izumi Shinji , Nakamura Yuichi , Tackeuchi Atsushi
Published: October 2021

InGaN quantum dots (QDs) are promising candidates for GaN-based all-visible optoelectronic devices such as micro light-emitting diode and laser. In this study, self-assembled InGaN/GaN multi-quantum dots (MQDs) have been grown by plasma-assisted molecular beam epitaxy on c-plane GaN-on-sapphire template. A high density of over 3.8 × 1010 cm−2 is achieved and InGaN QDs exhibit a relatively uniform size distribution and good dispersity. Strong localization effect in as-grown InGaN QDs has been evidenced by temperature-dependent photoluminescence (PL). The variation of peak energy is as small as 35 meV with increasing temperature from 10 K to 300 K, implying excellent temperature stability of emission wavelength for InGaN MQDs. Moreover, the radiative and nonradiative recombination times were calculated by time-resolved PL (TRPL) measurements, and the temperature dependence of PL decay times reveal that radiative recombination dominates the recombination process due to the low dislocation density of QDs structure.
Raman Study of Polycrystalline Si3N4 Irradiated with Swift Heavy Ions
Authors: Zhumazhanova Ainash , Mutali Alisher , Ibrayeva Anel , Skuratov Vladimir , Dauletbekova Alma , Korneeva Ekaterina , Akilbekov Abdirash , Zdorovets Maxim
Published: October 2021

A depth-resolved Raman spectroscopy technique was used to study the residual stress profiles in polycrystalline silicon nitride that was irradiated with Xe (167 MeV, 1 × 1011 cm−2 ÷ 4.87 × 1013 cm−2) and Bi (710 MeV, 1 × 1011 cm−2 ÷ 1 × 1013 cm−2) ions. It was shown that both the compressive and tensile stress fields were formed in the irradiated specimen, separated by a buffer zone that was located at a depth that coincided with the thickness of layer, amorphized due to multiple overlapping track regions. The compressive stresses were registered in a subsurface region, while at a greater depth, the tensile stresses were recorded and their levels reached the maximum value at the end of ion range. The size of the amorphous layer was evaluated from the dose dependence of the full width at half maximum (FWHM) (FWHM of the dominant 204 cm−1 line in the Raman spectra and scanning electron microscopy.
Effects of Specularite on the Preheating and Roasting Characteristics of Fluorine-Bearing Iron Concentrate Pellets
Authors: Wang Shuai , Jiang Ying , Guo Yufeng , Chen Feng , Yang Lingzhi
Published: October 2021

Fluorine-bearing iron ore is unique and complex. Serious preheating and roasting problems of fluorine-bearing iron concentrate pellets appear during the industrial production by the grate-kiln process. Besides, specularite has low hydrophilicity, undesirable particle size and shape, dense and smooth particle surface and poor assimilation performance. Thus, it has not yet been widely applied in production. This study applied the specularite to improve the preheating and roasting characteristics of the fluorine-bearing iron concentrate pellets. The experiment results indicated that the roasting properties of fluorine-bearing iron concentrate pellets were improved and the compression strength of roasted pellets increased with the addition of 10% specularite. The suitable roasting temperature range was expanded to more than 140 °C. Compared to other addition, the total iron of pellets was also increased. In addition, the improvement mechanism of adding specularite on the properties of fluorine-bearing iron concentrate pellets was discussed.
Karyotype Organization of the Endangered Species Yellow Cardinal (Gubernatrix cristata)
Authors: Bülau Sandra Eloisa , Kretschmer Rafael , Furo Ivanete de Oliveira , de Oliveira Edivaldo Herculano Correa , de Freitas Thales Renato Ochotorena
Published: October 2021

Karyotypic analyses have several applications in studies of chromosome organization, evolution, and cytotaxonomy. They are also essential to genome assembly projects. Here, we present for the first time the karyotype description of the endangered species yellow cardinal, Gubernatrix cristata (Passeriformes, Thraupidae), using conventional staining with Giemsa and 18S rDNA probes. This species has 78 chromosomes, with 12 pairs of macrochromosomes and 27 microchromosome pairs. The 18S rDNA clusters were found in four microchromosomes. Our results revealed that G. cristata has a typical avian karyotype (approximately 80 chromosomes). However, G. cristata has an apomorphic state in relation to the 18S rDNA distribution since the ancestral condition corresponds to only two microchromosomes with these sequences. Probably, duplications and translocations were responsible for increasing the number of 18S rDNA clusters in G. cristata. The results were compared and discussed with respect to other Thraupidae and Passeriformes members. Considering the globally threatened status of G. cristata, we believe that its karyotype description could be a starting point for future cytogenetics and sequencing projects.
Lindblad Dynamics and Disentanglement in Multi-Mode Bosonic Systems
Authors: Kiselev Alexei D. , Ali Ranim , Rybin Andrei V.
Published: October 2021

In this paper, we consider the thermal bath Lindblad master equation to describe the quantum nonunitary dynamics of quantum states in a multi-mode bosonic system. For the two-mode bosonic system interacting with an environment, we analyse how both the coupling between the modes and the coupling with the environment characterised by the frequency and the relaxation rate vectors affect dynamics of the entanglement. We discuss how the revivals of entanglement can be induced by the dynamic coupling between the different modes. For the system, initially prepared in a two-mode squeezed state, we find the logarithmic negativity as defined by the magnitude and orientation of the frequency and the relaxation rate vectors. We show that, in the regime of finite-time disentanglement, reorientation of the relaxation rate vector may significantly increase the time of disentanglement.
Topology and Phase Transitions: A First Analytical Step towards the Definition of Sufficient Conditions
Authors: Di Cairano Loris , Gori Matteo , Pettini Marco
Published: October 2021

Different arguments led to supposing that the deep origin of phase transitions has to be identified with suitable topological changes of potential related submanifolds of configuration space of a physical system. An important step forward for this approach was achieved with two theorems stating that, for a wide class of physical systems, phase transitions should necessarily stem from topological changes of energy level submanifolds of the phase space. However, the sufficiency conditions are still a wide open question. In this study, a first important step forward was performed in this direction; in fact, a differential equation was worked out which describes how entropy varies as a function of total energy, and this variation is driven by the total energy dependence of a topology-related quantity of the relevant submanifolds of the phase space. Hence, general conditions can be in principle defined for topology-driven loss of differentiability of the entropy.
Quantifying the Autonomy of Structurally Diverse Automata: A Comparison of Candidate Measures
Authors: Albantakis Larissa
Published: October 2021

Should the internal structure of a system matter when it comes to autonomy? While there is still no consensus on a rigorous, quantifiable definition of autonomy, multiple candidate measures and related quantities have been proposed across various disciplines, including graph-theory, information-theory, and complex system science. Here, I review and compare a range of measures related to autonomy and intelligent behavior. To that end, I analyzed the structural, information-theoretical, causal, and dynamical properties of simple artificial agents evolved to solve a spatial navigation task, with or without a need for associative memory. By contrast to standard artificial neural networks with fixed architectures and node functions, here, independent evolution simulations produced successful agents with diverse neural architectures and functions. This makes it possible to distinguish quantities that characterize task demands and input-output behavior, from those that capture intrinsic differences between substrates, which may help to determine more stringent requisites for autonomous behavior and the means to measure it.
Taming the Chaos in Neural Network Time Series Predictions
Authors: Raubitzek Sebastian , Neubauer Thomas
Published: October 2021

Machine learning methods, such as Long Short-Term Memory (LSTM) neural networks can predict real-life time series data. Here, we present a new approach to predict time series data combining interpolation techniques, randomly parameterized LSTM neural networks and measures of signal complexity, which we will refer to as complexity measures throughout this research. First, we interpolate the time series data under study. Next, we predict the time series data using an ensemble of randomly parameterized LSTM neural networks. Finally, we filter the ensemble prediction based on the original data complexity to improve the predictability, i.e., we keep only predictions with a complexity close to that of the training data. We test the proposed approach on five different univariate time series data. We use linear and fractal interpolation to increase the amount of data. We tested five different complexity measures for the ensemble filters for time series data, i.e., the Hurst exponent, Shannon’s entropy, Fisher’s information, SVD entropy, and the spectrum of Lyapunov exponents. Our results show that the interpolated predictions consistently outperformed the non-interpolated ones. The best ensemble predictions always beat a baseline prediction based on a neural network with only a single hidden LSTM, gated recurrent unit (GRU) or simple recurrent neural network (RNN) layer. The complexity filters can reduce the error of a random ensemble prediction by a factor of 10. Further, because we use randomly parameterized neural networks, no hyperparameter tuning is required. We prove this method useful for real-time time series prediction because the optimization of hyperparameters, which is usually very costly and time-intensive, can be circumvented with the presented approach.
Entropy in Landscape Ecology: A Quantitative Textual Multivariate Review
Authors: Cushman Samuel A.
Published: October 2021

This paper presents a multivariate textual analysis of more than 1300 papers on entropy in ecology. There are six main insights that emerged. First, there is a large body of literature that has addressed some aspect of entropy in ecology, most of which has been published in the last 5–10 years. Second, the vast majority of these papers focus on species distribution, species richness, relative abundance or trophic structure and not landscape-scale patterns or processes, pe se. Third, there have been few papers addressing landscape-level questions related to entropy. Fourth, the quantitative analysis with hierarchical clustering identified a strongly nested structure among papers that addressed entropy in ecology. Fifth, there is clear differentiation of papers focused on landscape-level applications of entropy from other papers, with landscape focused papers clustered together at each level of the hierarchy in a relatively small and closely associated group. Sixth, this group of landscape-focused papers was substructured between papers that explicitly adopted entropy measures to quantify the spatial pattern of landscape mosaics, often using variations on Boltzmann entropy, versus those that utilize Shannon entropy measures from information theory, which are not generally explicit in their assessment of spatial configuration. This review provides a comprehensive, quantitative assessment of the scope, trends and relationships among a large body of literature related to entropy in ecology and for the first time puts landscape ecological research on entropy into that context.
Research of ZnO Arrester Deterioration Mechanism Based on Electrical Performance and Micro Material Test
Authors: Zhang Qizhe , Wang Shenghui , Dong Xinghao , Liu Mingliang , Ou Qi , Lv Fangcheng
Published: October 2021

The traction power supply system of an Electrical Multiple Unit (EMU) often suffers from overvoltage impact. As an important protection device for on-board electrical equipment, the working environment of a roof arrester is worse than that of a power system. In recent years, the explosion failure of the roof arresters of an EMU has occurred from time to time, which seriously endangers the safe operation of high-speed railways. In this paper, the electrical performance test and material micro test of roof arrester in three states of normal, defect, and exploded, are carried out in order to study the internal causes of roof arrester explosion and clarify its deterioration mechanism. Using the DC reference voltage test and leakage current test, the electrical performance differences of normal, defective, and exploded arresters are obtained. By studying the disassembly of an arrester, the appearance characteristics of arrester varistor in three states are obtained. The micro morphology and chemical elements of the varistor are analyzed by Scanning Electron Microscope and Energy Dispersive Spectrometer. The deterioration mechanism of the arrester varistor is then revealed, and preventive measures for the explosion failure of the roof arrester are put forward. The obtained results show that, during the long-term operation of the roof arrester of an EMU, the varistor may be damp, and therefore the aluminum electrode layer and side insulation layer of the varistor may deteriorate. After the deterioration of the aluminum electrode layer, the content of the O element increases, and multiple film structures are formed on the surface. After the deterioration of the side insulating layer, the content of the O element increases, and the surface becomes uneven. Improving the sealing performance requirements of the roof arrester and optimizing the maintenance process can reduce its explosion failure.
Robust Single-Image Dehazing
Authors: Kim Changwon
Published: October 2021

This paper proposes a new single-image dehazing method, which is an important preprocessing step in vision applications to overcome the limitations of the conventional dark channel prior. The dark channel prior has a tendency to underestimate transmissions of bright regions or objects that can generate color distortions during the process of dehazing. In order to suppress the distortions in a large sky area or a bright white object, the sky probabilities and the white-object probabilities calculated in the non-sky area are proposed. The sky area is detected by combining the advantages of a region-based and a boundary-based sky segmentation in order to consider various sky shapes in road scenes. The performance of the proposed methods is evaluated using synthetic and real-world datasets. When compared to conventional methods in the reviewed literature, the proposed method produces significant improvements concerning visual and numerical criteria.
Magnetic Coupler Optimization for Inductive Power Transfer System of Unmanned Aerial Vehicles
Authors: Li Xiaokun , Lu Junwei , Stegen Sascha
Published: October 2021

Unmanned aerial vehicles (UAVs) have been widely used in military and civilian applications. However, the insufficient cruising range restricts the development of UAVs due to the limitation of their battery. Inductive power transfer (IPT) is an effective way to charge the battery and solve this problem. Magnetic coupler is a key component of the IPT system, which greatly affects the power transfer and efficiency of the IPT. This paper proposes a new magnetic coupler with vertical spiral coils and ferrite PQI cores for the IPT system of UAVs, which can enhance the magnetic coupling and improve the performance of the IPT system. Finite element simulations are used to investigate the magnetic field distribution and coupling capability of the proposed magnetic coupler. In addition, an experimental platform is built to prove the validity of the IPT system using the proposed magnetic coupler. The results show that the coupling coefficient can reach 0.98, and the system transfer efficiency is 89.27% with an output power of 93 W. The IPT system also has a perfect misalignment tolerance and can achieve a stable output power.
The Environmental Efficiency Analysis Based on the Three-Step Method for Two-Stage Data Envelopment Analysis
Authors: Yan Qingyou , Zhao Fei , Wang Xu , Balezentis Tomas
Published: October 2021

This paper suggests that the efficiency of a system (decision-making unit) and its subsystem cannot be properly measured using a two-stage data envelopment analysis (DEA) model either in cooperative or non-cooperative evaluation. Indeed, the existing methods subjectively determine the status of the subsystems in the whole system. The two-stage DEA models, either cooperative game or non-cooperative game, are used to analyze the environmental efficiency. However, when the actual relationship between the two subsystems is inconsistent with the subjective relationship assumptions, the overall efficiency of the system and the efficiency of each subsystem will be biased. The conventional two-stage DEA models require predetermining the relationship between the subsystems within the system based on the subjective judgment of the decision-maker. Based on this, this paper proposes a three-step method to solve the two-stage DEA. First, the position relation among subsystems is determined according to the optimal weights through the model. According to the status relationship among subsystems, the decision units are grouped, and the two-stage DEA model of cooperative game or non-cooperative game is used to analyze the efficiency in each group. This method reduces the subjectivity of decision making and analyzes the efficiency of each decision unit applying the most appropriate two-stage DEA model to find the source of inefficiency. Finally, this paper verifies the rationality and validity of the method by analyzing the water use efficiency of industrial systems in China. It is found that most regions in China value economic development more than environmental protection (as evidenced by the DEA weights). What is more, the method proposed by the paper can be generalized for any two-stage DEA problem.