bluuebunny/crossref_metadata_2025 huggingface dataset:
Firm-Value Effects of Carbon Emissions and Carbon Disclosures—Evidence from Korea
Authors: Lee Jeong-Hwan , Cho Jin-Hyung
Published: November 2021

We examine the association between carbon emissions, carbon disclosures, and firm value for Korean firms, with a particular interest in chaebols, a special type of Korean conglomerate. Using hand-collected carbon emissions and firm-specific data for 841 Korean firms, including 514 chaebols and 335 non-chaebols, we find a significantly positive relationship between carbon emissions and firm value among chaebol affiliates. This result contrasts with previous findings conducted in advanced markets, where investors consider carbon emissions to be destructive. In terms of the voluntary disclosure policy, we find that companies with good environmental performance tend to disclose carbon emissions voluntarily. We further argue that these findings originate from the specific business atmosphere in Korea. Our results support the traditional view of corporations in terms of environmental policy and highlight the importance of firm characteristics and historical developments in the analysis of environmental policy.
Exploring the Associations between Perceived Organizational Support and Job Burnout among Chinese Academic Journal Editors: A Moderated Mediation Model
Authors: Yu Xiaoyan , Wu Shiyong , Chen Wei , Zheng Wen , Huang Mingxi , Yang Lei , Zhou Shuyi
Published: November 2021

Background: Job burnout (JB) has become a prevalent emotional and psychological syndrome across diverse contexts, especially in the face of the COVID-19 pandemic. This study aimed to examine the relationship between perceived organizational support (POS), job satisfaction (JS), self-efficacy (SE), and JB, alongside their mechanism of interplay. Methods: We took 210 Chinese academic journal editors as the research participants and designed a moderated mediation model to examine the posited construct. All the data were gathered online and analyzed with the statistical software SPSS and SmartPLS. Results: The participants comprised 117 women (55.71%) and 93 men (44.29%). There were significant differences among observed variables in age, experience, and title. POS had a significant negative predictive effect on JB (95% CI = −0.43; −0.06). JS mediated the relationship between POS and JB (95% CI = −0.48; −0.11). SE moderated the association between JS and JB (95% CI = 0.04; 0.75) but did not function as a moderator in the relationship between POS and JS (95% CI = −0.01; 0.24). Conclusions: POS, JS, and SE were crucial determinants of JB among Chinese academic journal editors. Targeted interventions should be initiated to diminish editors’ feelings of being unappreciated, inefficient, dissatisfied, and unaccomplished at work.
Real-Time Infoveillance of Moroccan Social Media Users’ Sentiments towards the COVID-19 Pandemic and Its Management
Authors: Ghanem Abdelghani , Asaad Chaimae , Hafidi Hakim , Moukafih Youness , Guermah Bassma , Sbihi Nada , Zakroum Mehdi , Ghogho Mounir , Dairi Meriem , Cherqaoui Mariam , Baina Karim
Published: November 2021

The impact of COVID-19 on socio-economic fronts, public health related aspects and human interactions is undeniable. Amidst the social distancing protocols and the stay-at-home regulations imposed in several countries, citizens took to social media to cope with the emotional turmoil of the pandemic and respond to government issued regulations. In order to uncover the collective emotional response of Moroccan citizens to this pandemic and its effects, we use topic modeling to identify the most dominant COVID-19 related topics of interest amongst Moroccan social media users and sentiment/emotion analysis to gain insights into their reactions to various impactful events. The collected data consists of COVID-19 related comments posted on Twitter, Facebook and Youtube and on the websites of two popular online news outlets in Morocco (Hespress and Hibapress) throughout the year 2020. The comments are expressed in Moroccan Dialect (MD) or Modern Standard Arabic (MSA). To perform topic modeling and sentiment classification, we built a first Universal Language Model for the Moroccan Dialect (MD-ULM) using available corpora, which we have fine-tuned using our COVID-19 dataset. We show that our method significantly outperforms classical machine learning classification methods in Topic Modeling, Emotion Recognition and Polar Sentiment Analysis. To provide real-time infoveillance of these sentiments, we developed an online platform to automate the execution of the different processes, and in particular regular data collection. This platform is meant to be a decision-making assistance tool for COVID-19 mitigation and management in Morocco.
Testing Hypoxia in Pig Meniscal Culture: Biological Role of the Vascular-Related Factors in the Differentiation and Viability of Neonatal Meniscus
Authors: Canciani Barbara , Herrera Millar Valentina Rafaela , Pallaoro Margherita , Aidos Lucia , Cirillo Federica , Anastasia Luigi , Peretti Giuseppe Maria , Modina Silvia Clotilde , Mangiavini Laura , Di Giancamillo Alessia
Published: November 2021

Menisci play an essential role in shock absorption, joint stability, load resistance and its transmission thanks to their conformation. Adult menisci can be divided in three zones based on the vascularization: an avascular inner zone with no blood supply, a fully vascularized outer zone, and an intermediate zone. This organization, in addition to the incomplete knowledge about meniscal biology, composition, and gene expression, makes meniscal regeneration still one of the major challenges both in orthopedics and in tissue engineering. To overcome this issue, we aimed to investigate the role of hypoxia in the differentiation of the three anatomical areas of newborn piglet menisci (anterior horn (A), central body (C), and posterior horn (P)) and its effects on vascular factors. After sample collection, menisci were divided in A, C, P, and they were cultured in vitro under hypoxic (1% O2) and normoxic (21% O2) conditions at four different experimental time points (T0 = day of explant; T7 = day 7; T10 = day 10; T14 = day 14); samples were then evaluated through immune, histological, and molecular analyses, cell morpho-functional characteristics; with particular focus on matrix composition and expression of vascular factors. It was observed that hypoxia retained the initial phenotype of cells and induced extracellular matrix production resembling a mature tissue. Hypoxia also modulated the expression of angiogenic factors, especially in the early phase of the study. Thus, we observed that hypoxia contributes to the fibro-chondrogenic differentiation with the involvement of angiogenic factors, especially in the posterior horn, which corresponds to the predominant weight-bearing portion.
Aquatic Toxicity Effects and Risk Assessment of ‘Form Specific’ Product-Released Engineered Nanomaterials
Authors: Lehutso Raisibe Florence , Wesley-Smith James , Thwala Melusi
Published: November 2021

The study investigated the toxicity effects of ‘form specific’ engineered nanomaterials (ENMs) and ions released from nano-enabled products (NEPs), namely sunscreens, sanitisers, body creams and socks on Pseudokirchneriella subcapitata, Spirodela polyrhiza, and Daphnia magna. Additionally, risk estimation emanating from the exposures was undertaken. The ENMs and the ions released from the products both contributed to the effects to varying extents, with neither being a uniform principal toxicity agent across the exposures; however, the effects were either synergistic or antagonistic. D. magna and S. polyrhiza were the most sensitive and least sensitive test organisms, respectively. The most toxic effects were from ENMs and ions released from sanitisers and sunscreens, whereas body creams and sock counterparts caused negligible effects. The internalisation of the ENMs from the sunscreens could not be established; only adsorption on the biota was evident. It was established that ENMs and ions released from products pose no imminent risk to ecosystems; instead, small to significant adverse effects are expected in the worst-case exposure scenario. The study demonstrates that while ENMs from products may not be considered to pose an imminent risk, increasing nanotechnology commercialization may increase their environmental exposure and risk potential; therefore, priority exposure cases need to be examined.
Metalloproteinases in Endometrial Cancer—Are They Worth Measuring?
Authors: Michalczyk Kaja , Cymbaluk-Płoska Aneta
Published: November 2021

Endometrial cancer is one of the most common gynecological malignancies, yet the molecular mechanisms that lead to tumor development and progression are still not fully established. Matrix metalloproteinases (MMPs) are a group of enzymes that play an important role in carcinogenesis. They are proteases involved in the degradation of the extracellular matrix (ECM) that surrounds the tumor and the affected tissue allows cell detachment from the primary tumor causing local invasion and metastasis formation. Recent investigations demonstrate significantly increased metalloproteinase and metalloproteinase inhibitor levels in patients with endometrial cancer compared to those with normal endometrium. In this review, we aim to show their clinical significance and possible use in the diagnosis and treatment of patients with endometrial cancer. We have critically summarized and reviewed the research on the role of MMPs in endometrial cancer.
Three-Dimensional Culture Systems for Dissecting Notch Signalling in Health and Disease
Authors: Marconi Guya Diletta , Porcheri Cristina , Trubiani Oriana , Mitsiadis Thimios A.
Published: November 2021

Three-dimensional (3D) culture systems opened up new horizons in studying the biology of tissues and organs, modelling various diseases, and screening drugs. Producing accurate in vitro models increases the possibilities for studying molecular control of cell–cell and cell–microenvironment interactions in detail. The Notch signalling is linked to cell fate determination, tissue definition, and maintenance in both physiological and pathological conditions. Hence, 3D cultures provide new accessible platforms for studying activation and modulation of the Notch pathway. In this review, we provide an overview of the recent advances in different 3D culture systems, including spheroids, organoids, and “organ-on-a-chip” models, and their use in analysing the crucial role of Notch signalling in the maintenance of tissue homeostasis, pathology, and regeneration.
The Membrane Proteome of Spores and Vegetative Cells of the Food-Borne Pathogen Bacillus cereus
Authors: Gao Xiaowei , Swarge Bhagyashree N. , Dekker Henk L. , Roseboom Winfried , Brul Stanley , Kramer Gertjan
Published: November 2021

Membrane proteins are fascinating since they play an important role in diverse cellular functions and constitute many drug targets. Membrane proteins are challenging to analyze. The spore, the most resistant form of known life, harbors a compressed inner membrane. This membrane acts not only as a barrier for undesired molecules but also as a scaffold for proteins involved in signal transduction and the transport of metabolites during spore germination and subsequent vegetative growth. In this study, we adapted a membrane enrichment method to study the membrane proteome of spores and cells of the food-borne pathogen Bacillus cereus using quantitative proteomics. Using bioinformatics filtering we identify and quantify 498 vegetative cell membrane proteins and 244 spore inner membrane proteins. Comparison of vegetative and spore membrane proteins showed there were 54 spore membrane-specific and 308 cell membrane-specific proteins. Functional characterization of these proteins showed that the cell membrane proteome has a far larger number of transporters, receptors and proteins related to cell division and motility. This was also reflected in the much higher expression level of many of these proteins in the cellular membrane for those proteins that were in common with the spore inner membrane. The spore inner membrane had specific expression of several germinant receptors and spore-specific proteins, but also seemed to show a preference towards the use of simple carbohydrates like glucose and fructose owing to only expressing transporters for these. These results show the differences in membrane proteome composition and show us the specific proteins necessary in the inner membrane of a dormant spore of this toxigenic spore-forming bacterium to survive adverse conditions.
Controlled Transdermal Iontophoresis of Insulin from Water-Soluble Polypyrrole Nanoparticles: An In Vitro Study
Authors: Tari Kamran , Khamoushian Soroush , Madrakian Tayyebeh , Afkhami Abbas , Łos Marek Jan , Ghoorchian Arash , Samarghandi Mohammad Reza , Ghavami Saeid
Published: November 2021

The iontophoresis delivery of insulin (INS) remains a serious challenge due to the low permeability of the drug through the skin. This work aims to investigate the potential of water-soluble polypyrrole nanoparticles (WS-PPyNPs) as a drug donor matrix for controlled transdermal iontophoresis of INS. WS-PPyNPs have been prepared via a simple chemical polymerization in the presence of sodium dodecyl sulfate (SDS) as both dopant and the stabilizing agent. The synthesis of the soluble polymer was characterized using field emission scanning electron microscopy (FESEM), dynamic light scattering (DLS), fluorescence spectroscopy, and Fourier transform infrared (FT–IR) spectroscopy. The loading mechanism of INS onto the WS-PPyNPs is based on the fact that the drug molecules can be replaced with doped dodecyl sulfate. A two-compartment Franz-type diffusion cell was employed to study the effect of current density, formulation pH, INS concentration, and sodium chloride concentration on anodal iontophoresis (AIP) and cathodal iontophoresis (CIP) of INS across the rat skin. Both AIP and CIP delivery of INS using WS-PPyNPs were significantly increased compared to passive delivery. Furthermore, while the AIP experiment (60 min at 0.13 mA cm–2) show low cumulative drug permeation for INS (about 20.48 µg cm−2); the CIP stimulation exhibited a cumulative drug permeation of 68.29 µg cm−2. This improvement is due to the separation of positively charged WS-PPyNPs and negatively charged INS that has occurred in the presence of cathodal stimulation. The obtained results confirm the potential applicability of WS-PPyNPs as an effective approach in the development of controlled transdermal iontophoresis of INS.
High-Throughput and Accurate Determination of Transgene Copy Number and Zygosity in Transgenic Maize: From DNA Extraction to Data Analysis
Authors: Liu Fang , Cheng Jinkui , Liu Xuhua , Wang Xi-Qing
Published: November 2021

It is vital to develop high-throughput methods to determine transgene copy numbers initially and zygosity during subsequent breeding. In this study, the target sequence of the previously reported endogenous reference gene hmg was analyzed using 633 maize inbred lines, and two SNPs were observed. These SNPs significantly increased the PCR efficiency, while the newly developed hmg gene assay (hmg-taq-F2/R2) excluding these SNPs reduced the efficiency into normal ranges. The TaqMan amplification efficiency of bar and hmg with newly developed primers was calculated as 0.993 and 1.000, respectively. The inter-assay coefficient of variation (CV) values for the bar and hmg genes varied from 1.18 to 2.94%. The copy numbers of the transgene bar using new TaqMan assays were identical to those using dPCR. Significantly, the precision of one repetition reached 96.7% of that of three repetitions of single-copy plants analyzed by simple random sampling, and the actual accuracy reached 95.8%, confirmed by T1 and T2 progeny. With the high-throughput DNA extraction and automated data analysis procedures developed in this study, nearly 2700 samples could be analyzed within eight hours by two persons. The combined results suggested that the new hmg gene assay developed here could be a universal maize reference gene system, and the new assay has high throughput and high accuracy for large-scale screening of maize varieties around the world.
The Modulatory Influence of Plant-Derived Compounds on Human Keratinocyte Function
Authors: Merecz-Sadowska Anna , Sitarek Przemysław , Zajdel Karolina , Kucharska Ewa , Kowalczyk Tomasz , Zajdel Radosław
Published: November 2021

The plant kingdom is a rich source of secondary metabolites with numerous properties, including the potential to modify keratinocyte biology. Keratinocytes are important epithelial cells that play a protective role against various chemical, physical and biological stimuli, and participate in reactive oxygen scavenging and inflammation and wound healing processes. The epidermal cell response may be modulated by phytochemicals via changes in signal transduction pathways. Plant extracts and single secondary compounds can possess a high antioxidant capacity and may suppress reactive oxygen species release, inhibit pro-apoptotic proteins and apoptosis and activate antioxidant enzymes in keratinocytes. Moreover, selected plant extracts and single compounds also exhibit anti-inflammatory properties and exposure may result in limited production of adhesion molecules, pro-inflammatory cytokines and chemokines in keratinocytes. In addition, plant extracts and single compounds may promote keratinocyte motility and proliferation via the regulation of growth factor production and enhance wound healing. While such plant compounds may modulate keratinocyte functions, further in vitro and in vivo studies are needed on their mechanisms of action, and more specific toxicity and clinical studies are needed to ensure their effectiveness and safety for use on human skin.
Structural and Functional Changes and Possible Molecular Mechanisms in Aged Skin
Authors: Lee Hyunji , Hong Yongjun , Kim Miri
Published: November 2021

Skin aging is a complex process influenced by intrinsic and extrinsic factors. Together, these factors affect the structure and function of the epidermis and dermis. Histologically, aging skin typically shows epidermal atrophy due to decreased cell numbers. The dermis of aged skin shows decreased numbers of mast cells and fibroblasts. Fibroblast senescence contributes to skin aging by secreting a senescence-associated secretory phenotype, which decreases proliferation by impairing the release of essential growth factors and enhancing degradation of the extracellular matrix through activation of matrix metalloproteinases (MMPs). Several molecular mechanisms affect skin aging including telomere shortening, oxidative stress and MMP, cytokines, autophagic control, microRNAs, and the microbiome. Accumulating evidence on the molecular mechanisms of skin aging has provided clinicians with a wide range of therapeutic targets for treating aging skin.
Melatonin and Pathological Cell Interactions: Mitochondrial Glucose Processing in Cancer Cells
Authors: Reiter Russel , Sharma Ramaswamy , Rosales-Corral Sergio , Manucha Walter , Chuffa Luiz Gustavo de Almeida , Zuccari Debora Aparecida Pires de Campos
Published: November 2021

Melatonin is synthesized in the pineal gland at night. Since melatonin is produced in the mitochondria of all other cells in a non-circadian manner, the amount synthesized by the pineal gland is less than 5% of the total. Melatonin produced in mitochondria influences glucose metabolism in all cells. Many pathological cells adopt aerobic glycolysis (Warburg effect) in which pyruvate is excluded from the mitochondria and remains in the cytosol where it is metabolized to lactate. The entrance of pyruvate into the mitochondria of healthy cells allows it to be irreversibly decarboxylated by pyruvate dehydrogenase (PDH) to acetyl coenzyme A (acetyl-CoA). The exclusion of pyruvate from the mitochondria in pathological cells prevents the generation of acetyl-CoA from pyruvate. This is relevant to mitochondrial melatonin production, as acetyl-CoA is a required co-substrate/co-factor for melatonin synthesis. When PDH is inhibited during aerobic glycolysis or during intracellular hypoxia, the deficiency of acetyl-CoA likely prevents mitochondrial melatonin synthesis. When cells experiencing aerobic glycolysis or hypoxia with a diminished level of acetyl-CoA are supplemented with melatonin or receive it from another endogenous source (pineal-derived), pathological cells convert to a more normal phenotype and support the transport of pyruvate into the mitochondria, thereby re-establishing a healthier mitochondrial metabolic physiology.
Azoxystrobin Impairs Neuronal Migration and Induces ROS Dependent Apoptosis in Cortical Neurons
Authors: Kang Jieun , Bishayee Kausik , Huh Sung-Oh
Published: November 2021

Fungicides often cause genotoxic stress and neurodevelopmental disorders such as autism (ASD). Fungicide-azoxystrobin (AZOX) showed acute and chronic toxicity to various organisms, and remained a concern for ill effects in developing neurons. We evaluated the neurotoxicity of AZOX in developing mouse brains, and observed prenatal exposure to AZOX reduced neuronal viability, neurite outgrowth, and cortical migration process in developing brains. The 50% inhibitory concentration (IC50) of AZOX for acute (24 h) and chronic (7 days) exposures were 30 and 10 μM, respectively. Loss in viability was due to the accumulation of reactive oxygen species (ROS), and inhibited neurite outgrowth was due to the deactivation of mTORC1 kinase activity. Pretreatment with ROS scavenger- N-acetylcysteine (NAC) reserved the viability loss and forced activation of mTORC1 kinase revived the neurite outgrowth in AZOX treated neurons. Intra-amniotic injection of AZOX coupled with in utero electroporation of GFP-labelled plasmid in E15.5 mouse was performed and 20 mg/kg AZOX inhibited radial neuronal migration. Moreover, the accumulation of mitochondria was significantly reduced in AZOX treated primary neurons, indicative of mitochondrial deactivation and induction of apoptosis, which was quantified by Bcl2/Bax ratio and caspase 3 cleavage assay. This study elucidated the neurotoxicity of AZOX and explained the possible cure from it.
The Dual-Channel Retailer’s Channel Synergy Strategy Decision
Authors: Zhang Peng , Xia Bei , Shi Victor
Published: November 2021

The main research question asked in this paper is whether and when a dual-channel retailer (retailer in short) should adopt the “buy online and pick up in store” (BOPS) strategy. To answer this question, we first derive the optimal price decision using the non-BOPS and BOPS strategies. Subsequently, we compare the performance of retailers under non-BOPS and BOPS scenarios. Our main findings are that under the monopoly scenario, retailers may not always benefit from the BOPS strategy. Retailers will benefit only if the offline operational costs are low and the degree of customer acceptance of the online channel is high. However, the BOPS strategy cannot improve dual-channel retailers’ market share. Furthermore, under a Stackelberg game scenario with e-retailers as leaders, when the value of a product is medium and the transaction costs of the offline channel are high, retailers can use the BOPS strategy to enhance their market share. If the degree of customer acceptance of the online channel is also high, retailers can further improve their profits by using the BOPS strategy. Overall, these findings not only provide decision support for retailers, but also enrich the theories on dual-channel retailing in operations management.
In Situ Remediation of Phosphogypsum with Water-Washing Pre-Treatment Using Cemented Paste Backfill: Rheology Behavior and Damage Evolution
Authors: Liu Yikai , Chen Qiusong , Wang Yunmin , Zhang Qinli , Li Hongpeng , Jiang Chaoyu , Qi Chongchong
Published: November 2021

The accumulation of original phosphogypsum (OPG) has occupied considerable land resources, which have induced significant environmental problems worldwide. The OPG-based cemented paste backfill (OCPB) has been introduced as a promising solution. In this study, a water-washing pre-treatment was used to purify OPG, aiming to optimize the transport performance and mechanical properties of backfills. The overall results proved that in treated phosphogypsum-based cemented paste backfill (TCPB), the altered particle size distribution can alleviate the shear-thinning characteristic. The mechanical properties were significantly optimized, of which a maximum increase of 183% of stress value was observed. With more pronounced AE signals, the TCPB samples demonstrated better residual structures after the ultimate strength values but with more unstable cracks with high amplitude generated during loading. Principal component analysis confirmed the adverse effects of fluorine and phosphorus on the damage fractal dimensions. The most voluminous hydration products observed were amorphous CSH and ettringite. The interlocked stellate clusters may be associated with the residual structure and the after-peak AE events evident in TCPB, indicate that more significant stress should be applied to break the closely interlocked stitches. Ultimately, the essential findings in this experimental work can provide a scientific reference for efficient OPG recycling.
Surface Integrity and Corrosion Resistance of 42CrMo4 High-Strength Steel Strengthened by Hard Turning
Authors: Xu Qingzhong , Liu Yan , Lu Haiyang , Liu Jichen , Cai Gangjun
Published: November 2021

To improve the surface corrosion resistance of 42CrMo4 high-strength steel used in a marine environment, this article studied the effects of hard turning on the surface integrity and corrosion resistance of 42CrMo4 high-strength steel through the single factor experimental method, namely hard turning, polarization corrosion, electrochemical impedance spectroscopy, potentiodynamic polarization curve, and salt spray tests. The results indicated that the surface integrity was modified by the hard turning, with a surface roughness lower than Ra 0.8 μm, decreased surface microhardness, fine and uniform surface microstructure, and dominant surface residual compressive stress. The hard turning process was feasible to strengthen the surface corrosion resistance of 42CrMo4 high-strength steel. The better corrosion resistance of the surface layer than that of the substrate material can be ascribed to the uniform carbides and compact microstructure. The corrosion resistance varied with cutting speeds as a result of the changed surface microhardness and residual compressive stress, varied with feed rates as a result of the changed surface roughness, and varied with cutting depths as a result of the changed surface residual compressive stress, respectively. The surface integrity with smaller surface roughness and microhardness and bigger surface residual compressive stress was beneficial for corrosion resistance.
Volume Integral Equation Method Solution for Spheroidal Inclusion Problem
Authors: Lee Jungki , Han Mingu
Published: November 2021

In this paper, the volume integral equation method (VIEM) is introduced for the numerical analysis of an infinite isotropic solid containing a variety of single isotropic/anisotropic spheroidal inclusions. In order to introduce the VIEM as a versatile numerical method for the three-dimensional elastostatic inclusion problem, VIEM results are first presented for a range of single isotropic/orthotropic spherical, prolate and oblate spheroidal inclusions in an infinite isotropic matrix under uniform remote tensile loading. We next considered single isotropic/orthotropic spherical, prolate and oblate spheroidal inclusions in an infinite isotropic matrix under remote shear loading. The authors hope that the results using the VIEM cited in this paper will be established as reference values for verifying the results of similar research using other analytical and numerical methods.
Taurine-Modified Boehmite Nanoparticles for GFRP Wind Turbine Rotor Blade Fatigue Life Enhancement
Authors: Adam Till Julian , Exner Wibke , Wierach Peter
Published: November 2021

Advanced nanoparticle-reinforced glass fibre composites represent a promising approach to improving the service life of fatigue-loaded structures such as wind turbine rotor blades. However, processing particle-reinforced resins using advanced infusion techniques is problematic due to, for example, higher viscosity as well as filtering effects. In this work, the effects of boehmite nanoparticles on viscosity, static properties and fatigue life are investigated experimentally. Whereas rheological analysis reveals a significant increase of viscosity in the case of pristine boehmite particles, an additional taurine surface modification of the particles can effectively reduce viscosity increase. As regards mechanical properties, significant improvements of both static as well as fatigue properties are found. The addition of 15 wt.% of boehmite particles increases fatigue life by a maximum of 270% compared to the unmodified fibre-reinforced epoxy. Transmitted light-based investigation of the damage mechanisms shows delayed initiation and smaller growth rates for laminates containing boehmite particles. At the same time, the observed mechanisms and their accumulation along the relative cycle number do not change significantly. In addition, by characterising autonomous heating, the so-called Risitano fatigue limit is determined. The results reveal that with increasing particle content there is an increase in the fatigue limit.
Factors Influencing the Hydration, Dimensional Stability, and Strength Development of the OPC-CSA-Anhydrite Ternary System
Authors: Yang Zhenzhen , Ye Hansong , Yuan Qiang , Li Baiyun , Li Yuelin , Zhou Dajun
Published: November 2021

Due to the advantages of high early strength and rapid setting, ternary systems consisting of ordinary Portland clinker (OPC), calcium sulphoaluminate (CSA) clinker, and anhydrite have broad application prospects. However, further studies need to be undertaken to find a more optimal mixing proportion of this ternary binder in order to meet basic performance requirements. In this paper, isothermal calorimetric tests, chemical shrinkage tests, drying shrinkage tests, and compressive strength tests were carried out to systematically identify the effect of the OPC/CSA ratio and anhydrite dosage on the hydration, mechanical property development, and dimensional stability of ternary binders. It was found that a higher CSA content leads to a higher cumulative hydration heat, a shorter acceleration period, and a delayed induction period, which can be ascribed to the retardation of C3S at a high aluminate concentration. However, a higher addition of anhydrite can retard the main peak of hydration despite promoting the intermediate peak and improving the hydration reaction rate. The drying shrinkage of blends decreases first along with the CSA proportion and then increases. Moreover, a higher anhydrite content mitigates the drying shrinkage and hinders the strength development. Finally, considering the properties of both the fresh and hardened binder, the ternary blends with 5% anhydrite and OPC/CSA ratios ranging from 3/7 to 2/8 were identified as most suitable for applications that require a high early strength, stable late strength, and small level of shrinkage.
Evaluation of the Behavior of Carbon Short Fiber Reinforced Concrete (CSFRC) Based on a Multi-Sensory Experimental Investigation and a Numerical Multiscale Approach
Authors: Lauff Philipp , Pugacheva Polina , Rutzen Matthias , Weiß Ursula , Fischer Oliver , Volkmer Dirk , Peter Malte A. , Grosse Christian U.
Published: November 2021

Carbon fiber reinforcement used in concrete has become a remarkable alternative to steel fibers. Admixing short fibers to fresh concrete and processing the material with a 3D printer leads to an orientation of fibers and a material with high uniaxial strength properties, which offers an economic use of fibers. To investigate its mechanical behavior, the material is subjected to flexural and tensional tests, combining several measuring techniques. Numerical analysis complements this research. Computed tomography is used with several post-processing algorithms for separating matrix and fibers. This helps to validate fiber alignment and serves as input data for numerical analysis with representative volume elements concatenating real fiber position and orientation with the three-dimensional stress tensor. Flexural and uniaxial tensional tests are performed combining multiple measuring techniques. Next to conventional displacement and strain measuring methods, sound emission analysis, in terms of quantitative event analysis and amplitude appraisal, and also high-resolution digital image correlation accompany the tests. Due to the electrical conductibility of carbon fibers, the material’s resistivity could be measured during testing. All sensors detect the material’s degradation behavior comparably, showing a strain-hardening effect, which results from multiple, yet locally restricted and distributed, microcracks arising in combination with plastic deformation.
The Application of Angulated Screw-Channels in Metal-Free, Implant-Supported Restorations: A Retrospective Survival Analysis
Authors: Rella Edoardo , De Angelis Paolo , Damis Giovanni , D’Addona Antonio , Manicone Paolo Francesco
Published: November 2021

Angulated screw channels (ASC) allow the clinician to reposition the access hole of screw-retained restorations, improving the design of the rehabilitation and the esthetic outcome. Few clinical studies are available on the efficacy of these restorations, especially at longer follow-ups and with a large number of subjects. The objective of this study was therefore to retrospectively evaluate patients rehabilitated with screw-retained restorations using ASC. The time of delivery and their adherence to the maintenance program was obtained, as well as the characteristics of the restoration and of the patient’s occlusion; a Kaplan–Meier survival curve was then built to investigate the success rate of these restorations and the effects of several variables were evaluated with a Cox model. A total of 105 subjects and 162 implants were enrolled in this study; after 42 months a success rate (92%) similar to what is reported for conventional screw-retained restorations was encountered. Monolithic zirconia restorations (n = 52) had a higher success rate (95%) when compared to partially veneered restorations (n = 53), which suffered a higher number of complications (90%). The other variables had no statistically significant effect. Implant supported prostheses adopting ASC provide a favorable outcome both in the posterior and anterior regions and can therefore be adopted to treat cases where the implant angulation is unfavorable for a conventional screw-retained prosthesis.
Interaction of Long Time Pulses of an Nd3+:YAG Laser Beam with the Heusler AlloyNi45Co5Mn35.5In14.5
Authors: Ciupak Patryk , Barłowski Artur , Sagan Piotr , Jasiński Tadeusz , Kuzma Marian
Published: November 2021

In this paper, the laser processing of the surface of bulk and layered samples (of thickness 75 nm) of Ni45Co5Mn35.5In14.5 alloy (NC5MI) was investigated using microsecond laser pulses. A Q-switched pulsed Nd3+:YAG laser, operating in the 1st harmonic (which had a wavelength of 1064 nm) with a pulse duration of 250 µs, was used. NC5MI is a metal resistant to thermal laser processing because its reflection coefficient is close to unity for long wavelengths. The aim of this paper was to learn the forms of laser processing (heating, microprocessing, ablation) for which the above-specified type of laser is useful. The samples were irradiated with various fluences in the interval of 5–32 J·cm−2. The effect of the laser interaction with the surface was explored by SEM microscopy. The threshold fluences for the bulk sample were determined as: the visible damage threshold (Fthd = 2 ± 0.2 J·cm−2), the melting threshold (Fthm = 10 ± 0.5 J·cm−2), and the deep melting threshold (Fthdm = 32 J·cm−2). Unexpectedly, these values wereincreased for the layer sample due to its silicon substrate. We have concluded that this type of laser radiation is advantageous for the annealing and melting of, or drilling holes in, the alloy, but disadvantageousto the ablation of the alloy.
Composites between Perovskite and Layered Co-Based Oxides for Modification of the Thermoelectric Efficiency
Authors: Harizanova Sonya , Faulques Eric , Corraze Benoit , Payen Christophe , Zając Marcin , Wilgocka-Ślęzak Dorota , Korecki Józef , Atanasova Genoveva , Stoyanova Radostina
Published: November 2021

The common approach to modify the thermoelectric activity of oxides is based on the concept of selective metal substitution. Herein, we demonstrate an alternative approach based on the formation of multiphase composites, at which the individual components have distinctions in the electric and thermal conductivities. The proof-of-concept includes the formation of multiphase composites between well-defined thermoelectric Co-based oxides: Ni, Fe co-substituted perovskite, LaCo0.8Ni0.1Fe0.1O3 (LCO), and misfit layered Ca3Co4O9. The interfacial chemical and electrical properties of composites are probed with the means of SEM, PEEM/XAS, and XPS tools, as well as the magnetic susceptibility measurements. The thermoelectric power of the multiphase composites is evaluated by the dimensionless figure of merit, ZT, calculated from the independently measured electrical resistivity (ρ), Seebeck coefficient (S), and thermal conductivity (λ). It has been demonstrated that the magnitude’s electric and thermal conductivities depend more significantly on the composite interfaces than the Seebeck coefficient values. As a result, the highest thermoelectric activity is observed at the composite richer on the perovskite (i.e., ZT = 0.34 at 298 K).
Effect of Two Brands of Glaze Material on the Flexural Strength and Probability of Failure of High Translucent Monolithic Zirconia
Authors: Singh Raj Gaurav , Li Kai Chun , Lyons Karl Michael , Waddell John Neil
Published: November 2021

(1) Background: The effect of glazing on the mechanical properties of monolithic high translucent zirconia is not well reported. Therefore, the purpose of this study was to evaluate the effect of glazing on the flexural strength of high translucent zirconia; (2) Methods: Ninety specimens were prepared from second-generation 3Y-TZP high translucent blocks and divided into three groups. Glaze materials were applied on one surface of the specimen and subjected to a four-point bending test and flexural stress and flexural displacement values were derived. Descriptive fractographic analysis of surfaces was conducted to observe the point of failure and fracture pattern.; (3) Results: Control-nonglazed (647.17, 1σ = 74.71 MPa) presented higher flexural strength values compared to glaze I (541.20, 1σ = 82.91 MPa) and glaze II (581.10, 1σ = 59.41 MPa). Characteristic strength (σƟ) from Weibull analysis also observed higher (660.67 MPa) values for the control specimens. Confocal microscopy revealed that glazed surfaces were much rougher than control surfaces. Descriptive fractographic analysis revealed that there was no correlation between the point of failure initiation and flexural strength; (4) Conclusions: The test results demonstrated that glazing significantly decreased the flexural strength and flexural displacement of the zirconia specimens.
Identification of the Fractional Zener Model Parameters for a Viscoelastic Material over a Wide Range of Frequencies and Temperatures
Authors: Pawlak Zdzisław M. , Denisiewicz Arkadiusz
Published: November 2021

The paper presents an analysis of the rheological properties of a selected viscoelastic material, which is dedicated to the reduction of vibrations in structures subjected to dynamic loads. A four-parameter, fractional Zener model was used to describe the dynamic behavior of the tested material. The model parameters were identified on the basis of laboratory tests performed at different temperatures and for different vibration frequencies. After proving that the material is thermoreologically simple, the so-called master curves were created using a horizontal shift factor. The Williams–Landel–Ferry formula was applied to create graphs of the master curves, the constants of which were determined for the selected temperature. The resulting storage and loss module functions spanned several decades in the frequency domain. The parameters of the fractional Zener model were identified by fitting the entire range of the master curves with the gradientless method (i.e., Particle Swarm Optimization), consisting in searching for the best-fitted solution in a set of feasible solutions. The parametric analysis of the obtained solutions allowed for the formulation of conclusions regarding the effectiveness of the applied rheological model.
Untapped Potential of Marine-Associated Cladosporium Species: An Overview on Secondary Metabolites, Biotechnological Relevance, and Biological Activities
Authors: Mohamed Gamal A. , Ibrahim Sabrin R. M.
Published: November 2021

The marine environment is an underexplored treasure that hosts huge biodiversity of microorganisms. Marine-derived fungi are a rich source of novel metabolites with unique structural features, bioactivities, and biotechnological applications. Marine-associated Cladosporium species have attracted considerable interest because of their ability to produce a wide array of metabolites, including alkaloids, macrolides, diketopiperazines, pyrones, tetralones, sterols, phenolics, terpenes, lactones, and tetramic acid derivatives that possess versatile bioactivities. Moreover, they produce diverse enzymes with biotechnological and industrial relevance. This review gives an overview on the Cladosporium species derived from marine habitats, including their metabolites and bioactivities, as well as the industrial and biotechnological potential of these species. In the current review, 286 compounds have been listed based on the reported data from 1998 until July 2021. Moreover, more than 175 references have been cited.
Complete Lipooligosaccharide Structure from Pseudoalteromonas nigrifaciens Sq02-Rifr and Study of Its Immunomodulatory Activity
Authors: Di Guida Rossella , Casillo Angela , Stellavato Antonietta , Di Meo Celeste , Kawai Soichiro , Kawamoto Jun , Ogawa Takuya , Kurihara Tatsuo , Schiraldi Chiara , Corsaro Maria Michela
Published: November 2021

Lipopolysaccharides (LPS) are surface glycoconjugates embedded in the external leaflet of the outer membrane (OM) of the Gram-negative bacteria. They consist of three regions: lipid A, core oligosaccharide (OS), and O-specific polysaccharide or O-antigen. Lipid A is the glycolipid endotoxin domain that anchors the LPS molecule to the OM, and therefore, its chemical structure is crucial in the maintenance of membrane integrity in the Gram-negative bacteria. In this paper, we reported the characterization of the lipid A and OS structures from Pseudoalteromonas nigrifaciens Sq02-Rifr, which is a psychrotrophic Gram-negative bacterium isolated from the intestine of Seriola quinqueradiata. The immunomodulatory activity of both LPS and lipid A was also examined.
Optically Transparent Flexible Broadband Metamaterial Absorber Based on Topology Optimization Design
Authors: Min Pingping , Song Zicheng , Yang Lei , Ralchenko Victor G. , Zhu Jiaqi
Published: November 2021

A conformal metamaterial absorber with simultaneous optical transparency and broadband absorption is proposed in this paper. The absorptance above 90% over a wide frequency range of 5.3–15 GHz can be achieved through topology optimization combined with a genetic algorithm (GA). The broadband absorption can be kept at incident angles within 45° and 70° for TE mode and TM mode, respectively. In the meantime, by employing transparent substrates, including polyvinyl chloride (PVC) and polyethylene terephthalate (PET), good optical transmittance and flexibility can be obtained simultaneously. The experimental results agree well with the numerical simulations, which further validates the reliability of our design and theoretical analysis. With its visible-wavelength transparency, flexibility, broadband absorption, low profile, excellent angle stability and polarization insensitivity, the proposed absorber is highly favored for practical applications in microwave engineering, such as electromagnetic interference and stealth technology. Moreover, the proposed design method of topology optimization can be extended to design the absorber quickly and efficiently, according to specific engineering requirements.
Improvement in Turn-Off Loss of the Super Junction IGBT with Separated n-Buffer Layers
Authors: Kim Ki Yeong , Noh Joo Seok , Yoon Tae Young , Kim Jang Hyun
Published: November 2021

In this study, we propose a super junction insulated-gate bipolar transistor (SJBT) with separated n-buffer layers to solve a relatively long time for carrier annihilation during turn-off. This proposition improves the turn-off characteristic while maintaining similar on-state characteristics and breakdown voltage. The electrical characteristics of the devices were simulated by using the Synopsys Sentaurus technology computer-aided design (TCAD) simulation tool, and we compared the conventional SJBT with SJBT with separated n-buffer layers. The simulation tool result shows that turn-off loss (Eoff) drops by about 7% when on-state voltage (Von) and breakdown voltage (BV) are similar. Von increases by about 0.5% and BV decreases by only about 0.8%.
Basalt from the Extinct Spreading Center in the West Philippine Basin: New Geochemical Results and Their Petrologic and Tectonic Implications
Authors: Yin Zhengxin , Wang Weiping , Chen Liang , Li Zhengyuan , Liu Qiang , Xie Anyuan
Published: November 2021

We present geological, bulk-rock geochemical and Sr–Nd–Hf isotopic data for mafic rocks from the West Philippine Basin (WPB). These mafic rocks comprise pillow basalts characterized by a vesicular structure. The mid-ocean ridge basalt (MORB)-normalized trace element patterns of basalts from the study area display depletions in Nb. In addition, the chondrite-normalized lanthanide patterns of basalts from the WPB are characterized by significant depletions in the light lanthanides and nearly flat Eu to Lu segments. The investigated rocks have initial 87Sr/86Sr ratios (87Sr/86Sr(i)) of 0.703339–0.703455 and high εNd(t) values (8.0 to 8.7). Furthermore, basalts from the WPB have 176Hf/177Hf ratios that range from 0.28318 to 0.28321 and high εHf(t) from 15.2 to 16.3. Semi-quantitative modeling demonstrates that the parental melts of basalts from the study area were derived by ~20% adiabatic decompression melting of a rising spinel-bearing peridotite source. The Sr–Nd–Hf isotopic compositions of basalts from the WPB indicate that their parental magmas were derived from an upper mantle reservoir possessing the so-called Indian-type isotopic anomaly. Interpretation of the isotopic data suggests that the inferred mantle source was most likely influenced by minor inputs of a sediment melt derived from a downgoing lithospheric slab. Collectively, the petrographic and geochemical characteristics of basalts from the study area are analogous to those of mafic rocks with a back-arc basin (BAB)-like affinity. As such, the petrogenesis of basalts from the WPB can be linked to upwelling of an Indian-type mantle source due to lithospheric slab subduction that was followed by back-arc spreading.