bluuebunny/crossref_metadata_2025 huggingface dataset:
Crosstalk among Indoleamines, Neuropeptides and JH/20E in Regulation of Reproduction in the American Cockroach, Periplaneta americana
Authors: Kamruzzaman A. S. M. , Mikani Azam , Mohamed Amr A. , Elgendy Azza M. , Takeda Makio
Published: March 2020

Although the regulation of vitellogenesis in insects has been mainly discussed in terms of ‘classical’ lipid hormones, juvenile hormone (JH), and 20-hydroxyecdysone (20E), recent data support the notion that this process must be adjusted in harmony with a nutritional input/reservoir and involvement of certain indoleamines and neuropeptides in regulation of such process. This study focuses on crosstalks among these axes, lipid hormones, monoamines, and neuropeptides in regulation of vitellogenesis in the American cockroach Periplaneta americana with novel aspects in the roles of arylalkylamine N-acetyltransferase (aaNAT), a key enzyme in indoleamine metabolism, and the enteroendocrine peptides; crustacean cardioactive peptide (CCAP) and short neuropeptide F (sNPF). Double-stranded RNA against aaNAT (dsRNAaaNAT) was injected into designated-aged females and the effects were monitored including the expressions of aaNAT itself, vitellogenin 1 and 2 (Vg1 and Vg2) and the vitellogenin receptor (VgR) mRNAs, oocyte maturation and changes in the hemolymph peptide concentrations. Effects of peptides application and 20E were also investigated. Injection of dsRNAaaNAT strongly suppressed oocyte maturation, transcription of Vg1, Vg2, VgR, and genes encoding JH acid- and farnesoate O-methyltransferases (JHAMT and FAMeT, respectively) acting in the JH biosynthetic pathway. However, it did not affect hemolymph concentrations of CCAP and sNPF. Injection of CCAP stimulated, while sNPF suppressed oocyte maturation and Vgs/VgR transcription, i.e., acting as allatomedins. Injection of CCAP promoted, while sNPF repressed ecdysteroid (20E) synthesis, particularly at the second step of Vg uptake. 20E also affected the JH biosynthetic pathway and Vg/VgR synthesis. The results revealed that on the course of vitellogenesis, JH- and 20E-mediated regulation occurs downstream to indoleamines- and peptides-mediated regulations. Intricate mutual interactions of these regulatory routes must orchestrate reproduction in this species at the highest potency.
Egg Parasitoids Survey of Spodoptera frugiperda (Smith) (Lepidoptera: Noctuidae) in Maize and Sorghum in Central Mexico
Authors: Jaraleño-Teniente Jannet , Lomeli-Flores J. Refugio , Rodríguez-Leyva Esteban , Bujanos-Muñiz Rafael , Rodríguez-Rodríguez Susana E.
Published: March 2020

Spodoptera frugiperda (Smith) is the main maize pest in America and was recently detected as an invasive pest in some countries in Asia and Africa. Among its natural enemies presented in Mexico, Trichogramma pretiosum Riley is the only egg parasitoid used in Integrated Pest Management (IPM) programs regardless of its effectiveness. A search for natural enemies of S. frugiperda was then carried out to determine whether this parasitoid has been established, and to detect native egg parasitoids or predators associated with this pest. The sentinel technique (egg masses) was used, and then placed in maize and sorghum fields in the state of Guanajuato, Mexico. Trichogramma atopovirilia Oatman and Platner, an egg parasitoid, and Chelonus insularis Cresson egg-larva parasitoid were recovered from field surveys. Among the natural enemies that preyed on eggs of S. frugiperda, we found mites of the genus Balaustium, and Dermaptera of the genus Doru, both species in great abundance. Laboratory tests were performed to compare the potential parasitism of T. atopovirilia against T. pretiosum. T. atopovirilia obtained 70.14% parasitism while T. pretiosum, 29.23%. In field cages, three doses of the parasitoids were tested. Total parasitism did not exceed 8% in any of the two species, but T. atopovirilia parasitized a greater number of hosts using two and three parasitoids per pest egg. Then, the use of Trichogramma species needs to be reevaluated in biological control programs against S. frugiperda.
Phylogeny of the Subtribe Monoctonina (Hymenoptera, Braconidae, Aphidiinae)
Authors: Čkrkić Jelisaveta , Petrović Andjeljko , Kocić Korana , Mitrović Milana , Kavallieratos Nickolas G. , van Achterberg Cornelis , Hebert Paul D. N. , Tomanović Željko
Published: March 2020

Members of the Monoctonina subtribe have long been neglected in applied studies of the subfamily Aphidiinae, due to their low economic importance, as they do not parasitize pests of cultivated plants. Consequently, data about this group are scarce, including its taxonomy and phylogeny. In the present study, we explore inter- and intraspecific genetic variation of Monoctonina species, including genera Monoctonus Haliday 1833, Monoctonia Starý 1962, Falciconus Mackauer 1959 and Harkeria Cameron 1900. We employ two molecular markers, the barcode region of the mitochondrial cytochrome c oxidase subunit I (COI) and the D2 region of the 28S nuclear gene (28S rDNA), to analyze genetic structuring and phylogeny of all available Monoctonina species, and combine them with morphological data for an integrative approach. We report one new species, and three potentially new species which can be formally described when further specimens are available. Analysis of phylogenetic relationships within the subtribe shows a basal position for the genera Falciconus and Monoctonia, and the close relatedness of Harkeria and Monoctonus.
Serum Zinc Level Grading System: A Useful Model for Composite Hepatic Events in Hepatitis C Virus-Associated Liver Cirrhosis
Authors: Nishikawa Hiroki , Enomoto Hirayuki , Yoh Kazunori , Iwata Yoshinori , Sakai Yoshiyuki , Kishino Kyohei , Shimono Yoshihiro , Ikeda Naoto , Takashima Tomoyuki , Aizawa Nobuhiro , Takata Ryo , Hasegawa Kunihiro , Ishii Noriko , Yuri Yukihisa , Nishimura Takashi , Iijima Hiroko , Nishiguchi Shuhei
Published: March 2020

We aimed to clarify the impact of the serum zinc (Zn) level grading system proposed by the Japanese society of clinical nutrition (JSCN: 80 μg/dL ≤ serum Zn level < 130 μg/dL (type A), 60 μg/dL ≤ serum Zn level < 80 μg/dL (type B), and serum Zn level < 60 μg/dL (type C)) in patients with hepatitis C virus (HCV)-related liver cirrhosis (LC) on the incidence of composite hepatic events (Com-HEs) compared with Child–Pugh (C–P) classification or albumin-bilirubin (ALBI) grade. (n = 275, median age = 67 years). The Akaike information criterion (AIC) was compared among three prognostic models. Factors associated with the incidence of Com-HEs were also studied. The first incidence of any HE was confirmed in 112 patients (40.7%). The AIC value for Com-HEs by the Zn level grading system was the lowest among the three prognostic models (AIC: 301.788 in Zn level grading system, 303.372 in ALBI grade, and 333.953 in C–P classification). In the multivariate analysis, male (p = 0.0031), ALBI grade 3 (p = 0.0041), type B (p = 0.0238), type C (p = 0.0004), and persistent viremia (p < 0.0001) were significant factors associated with the incidence of Com-HEs. In conclusion, the serum Zn level grading system proposed by JSCN can be helpful for estimating the incidence of Com-HEs in HCV-related LC patients.
Determining the Significance of Coronary Plaque Lesions: Physiological Stenosis Severity and Plaque Characteristics
Authors: Clarke John-Ross D. , Duarte Lau Freddy , Zarich Stuart W.
Published: March 2020

The evaluation of coronary lesions has evolved in recent years. Physiologic-guided revascularization (particularly with pressure-derived fractional flow reserve (FFR)) has led to superior outcomes compared to traditional angiographic assessment. A greater importance, therefore, has been placed on the functional significance of an epicardial lesion. Despite the improvements in the limitations of angiography, insights into the relationship between hemodynamic significance and plaque morphology at the lesion level has shown that determining the implications of epicardial lesions is rather complex. Investigators have sought greater understanding by correlating ischemia quantified by FFR with plaque characteristics determined on invasive and non-invasive modalities. We review the background of the use of these diagnostic tools in coronary artery disease and discuss the implications of analyzing physiological stenosis severity and plaque characteristics concurrently.
Influence of Regular Physical Activity on Mitochondrial Activity and Symptoms of Burnout—An Interventional Pilot Study
Authors: Brand Serge , Ebner Katarina , Mikoteit Thorsten , Lejri Imane , Gerber Markus , Beck Johannes , Holsboer-Trachsler Edith , Eckert Anne
Published: March 2020

Background: Occupational burnout is both a serious public and individual health concern. Psychopharmacological and psychological interventions are often employed, while interventions involving physical activity have been less frequently studied. The aims of the present study were (1) to investigate the effects of physical activity on mitochondrial activity levels and symptoms of burnout, (2) to compare the mitochondrial activity levels and symptoms of burnout of individuals suffering burnout with those of healthy controls (HCs), and (3) to explore the associations between mitochondrial activity and burnout symptoms. Methods: Twelve males with burnout (mean age: M = 45.8 years) took part in the study. At baseline and after 12 weeks of an intervention involving physical activity, participants completed questionnaires covering symptoms of burnout and depression. In parallel, blood samples were taken to measure changes in mitochondrial functional outcomes, such as ATP levels, oxygen consumption and complex I. For comparison, baseline values of healthy controls (HCs; depression and burnout questionnaires; blood samples) were assessed. Results: Over time, symptoms of burnout (emotional exhaustion and depersonalization) and depression significantly decreased in participants with burnout (large effect sizes) but remained significantly higher than those of HCs (medium to large effect sizes). Personal accomplishment increased over time (medium effect size) but was still lower than for HCs (large effect size). At baseline and compared to HCs, individuals with burnout had significantly lower ATP levels of mitochondrial functional outcomes. Over time, mitochondrial activity levels increased among individuals with burnout. High baseline mitochondrial activity was significantly correlated with lower depression and burnout scores both at baseline and at the end of the study. Conclusions: In individuals with burnout, regular physical activity had positive effects on mitochondrial activity and on symptoms of burnout and depression. However, when compared to healthy controls, full remission was not achieved.
3,2′-Dihydroxyflavone Improves the Proliferation and Survival of Human Pluripotent Stem Cells and Their Differentiation into Hematopoietic Progenitor Cells
Authors: Kim Kyeongseok , Abdal Dayem Ahmed , Gil Minchan , Yang Gwang-Mo , Lee Soo Bin , Kwon Oh-Hyung , Choi Sangbaek , Kang Geun-Ho , Lim Kyung Min , Kim Dongho , Cho Ssang-Goo
Published: March 2020

Efficient maintenance of the undifferentiated status of human pluripotent stem cells (hiPSCs) is crucial for producing cells with improved proliferation, survival and differentiation, which can be successfully used for stem cell research and therapy. Here, we generated iPSCs from healthy donor peripheral blood mononuclear cells (PBMCs) and analyzed the proliferation and differentiation capacities of the generated iPSCs using single cell NGS-based 24-chromosome aneuploidy screening and RNA sequencing. In addition, we screened various natural compounds for molecules that could enhance the proliferation and differentiation potential of hiPSCs. Among the tested compounds, 3,2′-dihydroxyflavone (3,2′-DHF) significantly increased cell proliferation and expression of naïve stemness markers and decreased the dissociation-induced apoptosis of hiPSCs. Of note, 3,2′-DHF-treated hiPSCs showed upregulation of intracellular glutathione (GSH) and an increase in the percentage of GSH-high cells in an analysis with a FreSHtracer system. Interestingly, culture of the 3,2′-DHF-treated hiPSCs in differentiation media enhanced their mesodermal differentiation and differentiation into CD34+ CD45+ hematopoietic progenitor cells (HPC) and natural killer cells (NK) cells. Taken together, our results demonstrate that the natural compound 3,2′-DHF can improve the proliferation and differentiation capacities of hiPSCs and increase the efficiency of HPC and NK cell production from hiPSCs.
Combining Immune Checkpoint Inhibitors with Anti-Angiogenic Agents
Authors: Ciciola Paola , Cascetta Priscilla , Bianco Cataldo , Formisano Luigi , Bianco Roberto
Published: March 2020

Immunotherapy has recently emerged as a novel strategy for treating different types of solid tumors, with promising results. However, still a large fraction of patients do not primarily respond to such approaches, and even responders sooner or later develop resistance. Moreover, immunotherapy is a promising strategy for certain malignancies but not for others, with this discrepancy having been attributed to a more immunogenic microenvironment of some tumors. As abnormal and augmented tumor vessels often occur in cancerogenesis, anti-angiogenic drugs have already demonstrated their effectiveness both in preclinical and in clinical settings. By targeting abnormal formation of tumor vessels, anti-angiogenetic agents potentially result in an enhanced infiltration of immune effector cells. Moreover, crosstalks downstream of the immune checkpoint axis and vascular endothelial growth factor receptor (VEGFR) signaling may result in synergistic effects of combined treatment in tumor cells. In this review, we will describe and discuss the biological rationale of a combined therapy, underlying the modification in tumor microenvironment as well as in tumor cells after exposure to checkpoint inhibitors and anti-angiogenic drugs. Moreover, we will highlight this strategy as a possible way for overcoming drug resistance. By first discussing potential prognostic and predictive factors for combined treatment, we will then turn to clinical settings, focusing on clinical trials where this strategy is currently being investigated.
The Hox Gene egl-5 Acts as a Terminal Selector for VD13 Development via Wnt Signaling
Authors: Kurland Meagan , O’Meara Bryn , Tucker Dana K. , Ackley Brian D.
Published: March 2020

Nervous systems are comprised of diverse cell types that differ functionally and morphologically. During development, extrinsic signals, e.g., growth factors, can activate intrinsic programs, usually orchestrated by networks of transcription factors. Within that network, transcription factors that drive the specification of features specific to a limited number of cells are often referred to as terminal selectors. While we still have an incomplete view of how individual neurons within organisms become specified, reporters limited to a subset of neurons in a nervous system can facilitate the discovery of cell specification programs. We have identified a fluorescent reporter that labels VD13, the most posterior of the 19 inhibitory GABA (γ-amino butyric acid)-ergic motorneurons, and two additional neurons, LUAL and LUAR. Loss of function in multiple Wnt signaling genes resulted in an incompletely penetrant loss of the marker, selectively in VD13, but not the LUAs, even though other aspects of GABAergic specification in VD13 were normal. The posterior Hox gene, egl-5, was necessary for expression of our marker in VD13, and ectopic expression of egl-5 in more anterior GABAergic neurons induced expression of the marker. These results suggest egl-5 is a terminal selector of VD13, subsequent to GABAergic specification.
Effect of Heat-Treatment on the Thermal and Mechanical Stability of Ni/Al2O3 Nanocrystalline Coatings
Authors: Cooke Kavian O. , Khan Tahir I. , Ali Shar Muhammad
Published: March 2020

Heat-treatment is a frequently used technique for modifying the physical and chemical properties of materials. In this study, the effect of heat-treatment on the mechanical properties, thermal stability and surface morphology of two types of electrodeposited coatings (pure-Ni and Ni/Al2O3) were investigated. The XRD analyses showed that the crystal structure of the as-deposited coating changes from slightly amorphous to crystalline as the heat-treatment temperature increases. The heat-treatment of both the pure-Ni and the Ni/Al2O3 coating caused an increase of the grain size within the coatings. However, the unreinforced Ni coating experienced a faster growth rate than the Ni/Al2O3 coating, which resulted in a larger average grain size. The temperature-driven changes to the microstructure of the coatings caused a reduction in the hardness and wear resistance of the coatings. The presence of nanoparticles within the Ni/Al2O3 coating can successfully extend the operational temperature range of the coating to 473 K by pinning grain boundaries.
A Semi-Infinite Numerical Wave Tank Using Discrete Particle Simulations
Authors: Lee Sangmin , Hong Jung-Wuk
Published: March 2020

With an increasing number of offshore structures for marine renewable energy, various experimental and numerical approaches have been performed to investigate the interaction of waves and structures to ensure the safety of the offshore structures. However, it has been very expensive to carry out real-scale large experiments and simulations. In this study, numerical waves with various relative depths and a wide range of wave steepness are precisely simulated by minimizing the wave reflection with a mass-weighted damping zone located at the end of a numerical wave tank (NWT). To achieve computational efficiency, optimal variables including initial spacing of smoothed particles, calculation time step, and damping coefficients are studied, and the numerical results are verified by comparison with both experimental data and analytical formula, in terms of wave height, particle velocities, and wave height-to-stroke ratio. Those results show good agreement for all wave steepness smaller than 0.067. By applying the proposed methodology, it is allowed to use a numerical wave tank of which the length is smaller than that of the wave tank used for experiments. The developed numerical technique can be used for the safety analysis of offshore structures through the simulation of fluid-structure interaction.
A Numerical Model for Offshore Mound Evolution
Authors: Zhang Jie , Larson Magnus
Published: March 2020

A numerical model was developed to simulate the evolution of a mound placed in the offshore (i.e., outside the zone of wave breaking), exposed to varying non-breaking waves and water levels. The net sediment transport rate is assumed to be mainly dominated by bed load transport, where wave asymmetry plays an important role. The net transport over a wave cycle is expressed with reference to an equilibrium profile, which ensures model reliability and robustness. In order to validate the model, data collected at two field sites, Cocoa Beach and Perdido Key Beach in Florida, USA, were employed. The numerical results show good agreement with the measured data from the two sites in terms of the profile evolution. It demonstrates that the model has the capability to simulate the evolution of mounds placed in the offshore. In addition, several scenarios with different mound volume and location designs were investigated to indicate potential uses for the model. The results illustrate how the mound evolution is influenced by the volume and location of the mound placement.
On the Separation Period Discriminating Gravity and Infragravity Waves off Gyeongpo Beach, Korea
Authors: Oh Jung-Eun , Jeong Weon-Mu , Chang Yeon S. , Oh Sang-Ho
Published: March 2020

Although there have been a number of studies investigating fundamental characteristics of infragravity waves in coastal zones, a proper method of deciding period ranges that are associated with gravity or infragravity waves remains uncertain. In this study, we proposed an empirical method of separating spectral energies of gravity and infragravity waves by analyzing the wave observation data acquired off Gyeongpo beach on the Korean east coast. The fundamental principle of the suggested method is to represent the separation period discriminating gravity and infragravity waves as a function of the significant wave period, rather than a fixed value that was conventionally applied in previous studies. As a consequence of using the new method, the relationships between heights and periods of gravity and infragravity waves were more clearly identified.
Strategic Asset Seeking and Innovation Performance: The Role of Innovation Capabilities and Host Country Institutions
Authors: Mi Lili , Yue Xiao-Guang , Shao Xue-Feng , Kang Yuanfei , Liu Yulong
Published: March 2020

Peering through the lenses of the strategic intent perspective and strategic fit paradigm, in this study, we seek to examine the contingent conditions under which emerging market multinational enterprises (EMNEs) with strategic asset seeking (SAS) intent can achieve improved innovation performance. We developed a contingency model of how the relationship between SAS intent and innovation performance is contingent on the moderating effects of firms’ innovation capability and institutional quality in the host country, as well as on the synergistic interaction of independent moderating effects from these two factors. We combined survey data from 320 Chinese MNEs with archival data to test our hypotheses. Our results show that SAS intent can lead to positive innovation performance when (a) the investing firm has developed high levels of innovation capability, and (b) synergistic interactions exist between institutional quality and firms’ innovation capability regarding their moderating effect on the SAS intent-innovation performance link.
Acknowledgement to Reviewers of Lubricants in 2019
Authors:   Lubricants Editorial Office
Published: March 2020

The editorial team greatly appreciates the reviewers who have dedicated their considerable time and expertise to the journal’s rigorous editorial process over the past 12 months, regardless of whether the papers are finally published or not [...]
Introducing Selectivity on Carbonaceous Material: Removing Noble Salts, Au3+, and Ag+ from Aqueous Media by Nanodiamonds Functionalized with Squaramides
Authors: Gutiérrez M. Susana , López Kenia A. , Morey Jeroni , Piña M. Nieves
Published: March 2020

Nanodiamonds coated with dopamine−squaramide compounds have been prepared by a calcination/esterification synthetic process, which improves the efficiency of this carbonaceous material with respect to non-functionalized nanodiamonds. The modified nanodiamonds show excellent selective coordination of Ag+ and Au3+ cations in a Cd2+, Co2+, Cr3+, Cu2+, Pb2+, and Zn2+ mixture in water. The coordination capacity of the carbonyl squaramide groups with the silver and gold cation is based on purely electrostatic cation−dipole interactions. Overall, it is demonstrated that the conjunction between the nanodiamonds and the organic receptor improves the selectivity of the material toward noble cations.
A Methodology for Porcine Circovirus 2 (PCV-2) Quantification Based on Gold Nanoparticles
Authors: Basso Caroline R. , Cruz Taís F. , Silva Bruna L. , Pedrosa Valber A. , Araújo Junior João P.
Published: March 2020

The aim of the current study is to introduce a methodology aimed at producing a biosensor that uses gold nanoparticles (AuNPs) to detect porcine circovirus 2 (PCV-2). This biosensor was based on AuNPs, which were modified with self-assembled monolayers (SAMs) and antibodies. The AuNPs’ surface and virus modification process applied to enable antibody binding was accompanied by localized surface plasmon resonance (LSPR), surface plasmon resonance (SPR), transmission electron microscopy (TEM), and energy-dispersive X-ray spectroscopy (EDX). Virus quantification was possible by the light absorption difference in the spectrum at concentrations of 105, 106, 107, 108, and 109 DNA copies/mL PCV-2 in relation to quantitative PCR (qPCR), with an R2 value >0.98. The visualization of colorimetric changes in the different PCV-2 concentrations was possible without the use of equipment. The biosensor production methodology presented reproducibility and specificity, as well as easy synthesis and low cost. An enhanced version of it may be used in the future to replace traditional tests such as PCR.
Effect of UV and Gamma Irradiation Sterilization Processes in the Properties of Different Polymeric Nanoparticles for Biomedical Applications
Authors: Tapia-Guerrero Y. S. , Del Prado-Audelo M. L. , Borbolla-Jiménez F. V. , Giraldo Gomez D. M. , García-Aguirre I. , Colín-Castro C. A. , Morales-González J. A. , Leyva-Gómez G. , Magaña J. J.
Published: March 2020

The sterilization processes of nanoparticles (NP) by autoclaving and filtration are two of the most utilized methods in the pharmaceutical industry but are not always a viable option. For this reason, the search for alternative options such as UV and gamma radiation is of interest. In this work, we evaluated both types of sterilization on two types of NP in solid state widely employed in the literature for biomedical applications, poly-(ε-caprolactone) and poly(d,l-lactide-co-glycolide) acid NP stabilized with polyvinyl alcohol. Physicochemical properties and cell viability were studied pre- and post-sterilization. The efficiency of irradiation sterilization was performed by a test of sterility using 1 × 108 CFU/mL of Escherichia coli, Staphylococcus aureus, and Candida albicans. Microbiological monitoring revealed that both methods were sufficient for sterilization. After the UV irradiation sterilization (100 µJ/cm2), no substantial changes were observed in the physicochemical properties of the NP or in the interaction or morphology of human glial cells, though 5 and 10 kGy of gamma irradiation showed slight changes of NP size as well as a decrease in cell viability (from 100 µg/mL of NP). At 5 kGy of radiation doses, the presence of trehalose as cryoprotectant reduces the cell damage with high concentrations of NP, but this did not occur at 10 kGy. Therefore, these methods could be highly effective and low-processing-time options for sterilizing NP for medical purposes. However, we suggest validating each NP system because these generally are of different polymer-composition systems.
Diffuse Sound Absorptive Properties of Parallel-Arranged Perforated Plates with Extended Tubes and Porous Materials
Authors: Li Dengke , Chang Daoqing , Liu Bilong
Published: March 2020

The diffuse sound absorption was investigated theoretically and experimentally for a periodically arranged sound absorber composed of perforated plates with extended tubes (PPETs) and porous materials. The calculation formulae related to the boundary condition are derived for the periodic absorbers, and then the equations are solved numerically. The influences of the incidence and azimuthal angle, and the period of absorber arrangement are investigated on the sound absorption. The sound-absorption coefficients are tested in a standard reverberation room for a periodic absorber composed of units of three parallel-arranged PPETs and porous material. The measured 1/3-octave band sound-absorption coefficients agree well with the theoretical prediction. Both theoretical and measured results suggest that the periodic PPET absorbers have good sound-absorption performance in the low- to mid-frequency range in diffuse field.
Comparison of Different Cervical Finish Lines of All-Ceramic Crowns on Primary Molars in Finite Element Analysis
Authors: Pan Chin-Yun , Lan Ting-Hsun , Liu Pao-Hsin , Fu Wan-Ru
Published: March 2020

This study aimed to conduct a stress analysis of four types of cervical finish lines in posterior all-ceramic crowns on the primary roots of molar teeth. Four different types of finish lines (shoulder 0.5 mm, feather-edged, chamfer 0.6 mm, and mini chamfer 0.4 mm) and two all-ceramic crown materials (zirconia and lithium disilicate) were used to construct eight finite element primary tooth models with full-coverage crowns. A load of 200 N was applied at two different loading angles (0° and 15°) so as to mimic children’s masticatory force and occlusal tendency. The maximum stress distribution from the three-dimensional finite element models was determined, and the main effect of each factor (loading type, material, and finish line types) was evaluated in terms of the stress values for all of the models. The results indicated that the loading type (90.25%) was the main factor influencing the maximum stress value of the primary root, and that the feather-edged margin showed the highest stress value (p = 0.002). In conclusion, shoulder and chamfer types of finish lines with a 0.4–0.6 mm thickness are recommended for deciduous tooth preparation, according to the biomechanical analysis.
Electrochemical Performance of Fe40Al-X (X = Cr, Ti, Co, Ni) Alloys Exposed to Artificial Saliva
Authors: Arrieta-Gonzalez Cinthya Dinorah , Rodriguez-Diaz Roberto Ademar , Mayen Jan , Retes-Mantilla Rogel Fernando , Torres-Mancera María Teresa , Oros-Méndez Lya Adlih , Cruz-Mejía Héctor , Flores-Garcia Nestor Starlin , Porcayo-Calderon Jesús
Published: March 2020

Fe–Al intermetallic compounds have been considered excellent candidates as alternative alloys for various applications in corrosive environments compared to other Fe-based alloys. Their excellent corrosion resistance is due to the development of an Al-based passive layer. The performance of the passive layer can be improved by adding a third alloy element. Therefore, in this study the electrochemical performance of the Fe40Al intermetallic alloy modified by the addition of a third alloy element (Cr, Ti, Co, Ni) is evaluated. The corrosion resistance of intermetallic alloys has been evaluated by electrochemical tests (potentiodynamic polarization curves, and measurements of open circuit potential, linear polarization and electrochemical impedance) in artificial saliva. The performance of intermetallic alloys was compared with that of Ti. The results obtained showed that the addition of Ni and Ti substantially improves the corrosion resistance of the base intermetallic. The corrosion resistance shown is comparable or greater than that shown by Ti. However, the addition of Co reduces the corrosion resistance of the base intermetallic.
Novel Bioactive and Therapeutic Root Canal Sealers with Antibacterial and Remineralization Properties
Authors: Baras Bashayer H. , Melo Mary Anne S. , Thumbigere-Math Vivek , Tay Franklin R. , Fouad Ashraf F. , Oates Thomas W. , Weir Michael D. , Cheng Lei , Xu Hockin H. K.
Published: March 2020

According to the American Dental Association Survey of Dental Services Rendered (published in 2007), 15 million root canal treatment procedures are performed annually. Endodontic therapy relies mainly on biomechanical preparation, chemical irrigation and intracanal medicaments which play an important role in eliminating bacteria in the root canal. Furthermore, adequate obturation is essential to confine any residual bacteria within the root canal and deprive them of nutrients. However, numerous studies have shown that complete elimination of bacteria is not achieved due to the complex anatomy of the root canal system. There are several conventional antibiotic materials available in the market for endodontic use. However, the majority of these antibiotics and antiseptics provide short-term antibacterial effects, and they impose a risk of developing antibacterial resistance. The root canal is a dynamic environment, and antibacterial and antibiofilm materials with long-term effects and nonspecific mechanisms of action are highly desirable in such environments. In addition, the application of acidic solutions to the root canal wall can alter the dentin structure, resulting in a weaker and more brittle dentin. Root canal sealers with bioactive properties come in direct contact with the dentin wall and can play a positive role in bacterial elimination and strengthening of the root structure. The new generation of nanostructured, bioactive, antibacterial and remineralizing additives into polymeric resin-based root canal sealers are discussed in this review. The effects of these novel bioactive additives on the physical and sealing properties, as well as their biocompatibility, are all important factors that are presented in this article.
Self-Assembly Processes in Hydrated Montmorillonite by FTIR Investigations
Authors: Caccamo Maria Teresa , Mavilia Giuseppe , Mavilia Letterio , Lombardo Domenico , Magazù Salvatore
Published: March 2020

Experimental findings obtained by FTIR and Raman spectroscopies on montmorillonite-water mixtures at three concentration values are presented. To get some insight into the hydrogen bond network of water within the montmorillonite network, FTIR and Raman spectra have been collected as a function of time and then analyzed following two complementary approaches: An analysis of the intramolecular OH stretching mode in the spectral range of 2700–3900 cm−1 in terms of two Gaussian components, and an analysis of the same OH stretching mode by wavelet cross-correlation. The FTIR and Raman investigations have been carried as a function of time for a montmorillonite-water weight composition (wt%) of 20–80%, 25–75%, and 35–65%, until the dehydrated state where the samples appear as a homogeneous rigid layer of clay. In particular, for both the FTIR and Raman spectra, the decomposition of the OH stretching band into a “closed” and an “open” contribution and the spectral wavelet analysis allow us to extract quantitative information on the time behavior of the system water content. It emerges that, the total water contribution inside the montmorillonite structure decreases as a function of time. However, the relative weight of the ordered water contribution diminishes more rapidly while the relative weight of the disordered water contribution increases, indicating that a residual water content, characterized by a highly structural disorder, rests entrapped in the montmorillonite layer structure for a longer time. From the present study, it can be inferred that the montmorillonite dehydration process promotes the layer self-assembly.
Self-Compacted Concrete with Self-Protection and Self-Sensing Functionality for Energy Infrastructures
Authors: Maria Cruz Alonso , Javier Puentes
Published: March 2020

This paper aims to demonstrate the self-protection and self-sensing functionalities of self-compacted concrete (SCC) containing carbon nanotubes (CNT) and carbon microfibers (CMF) in a hybrid system. The ability for self-sensing at room temperature and that of self-protection after thermal fatigue cycles is evaluated. A binder containing a high volume of supplementary mineral additions (30%BFSand20%FA) and different type of aggregates (basalt, limestone, and clinker) are used. The self-diagnosis is assessed measuring electrical resistivity (ER) and piezoresistivity (PZR) in compression mode within the elastic region of the concrete. Thermal fatigue is evaluated with mechanical and crack measurements after heat cycles (290–550 °C). SCC withstands high temperature cycles. The protective effect of the hybrid additive (CNT+CMF) notably diminishes damage by keepinghigher residual strength and lessmicrocracking of the concrete. Significant reductions in ER are detected. The self-diagnosis ability of functionalized SCC isconfirmed with PZR. A content of the hybrid functional additive (CNT+CMF) in the percolation region is recommended to maximize the self-sensing sensitivity. Other parameters as sample geometry, sensor location, power supply, and load level have less influence.
Single Tracks as a Key Factor in Additive Manufacturing Technology—Analysis of Research Trends and Metal Deposition Behavior
Authors: Patalas-Maliszewska Justyna , Feldshtein Eugene , Devojno Oleg , Śliwa Małgorzata , Kardapolava Marharyta , Lutsko Nikolaj
Published: March 2020

In recent years, general studies on Selective Laser Melting (SLM)/Selective Laser Sintering (SLS)/direct metal deposition (DMD) technologies, as well as studies on detailed issues in this area, have been carried out. However, a research gap is observed in investigations into the features of single tracks in the above-mentioned technologies. On the basis of data published in 2016–2019, an approach was adopted for a preliminary quantitative analysis of the knowledge base and also trends observed in the development of new technologies. This study demonstrates the effectiveness of the data mining technique based on the Bayes algorithm for analyzing trends in processes of additive manufacturing and the practical application of the knowledge received using the Bayes algorithm. After the analyses referred to above were completed, single and double layers of a composite material based on the Ni-based alloy and Fe–Al bronze were analyzed under different processing conditions. The effects of laser spot speeds and pitches on microhardness, microstructure, and interlayers’ features were described. So, the innovative approach, namely, the combination of the analysis of the scientific database of the phenomenon under study and the subsequent experimental investigation of its features, is the scientific novelty of the present study.
Study of Microwave Heating Effect in the Behaviour of Graphene as Second Phase in Ceramic Composites
Authors: Benavente Rut , Salvador María Dolores , Centeno Alba , Alonso Beatriz , Zurutuza Amaia , Borrell Amparo
Published: March 2020

The choice of the right material is essential in microwave processing. The carbon materials are good microwave absorbers, which allows them to be transformed by microwave heating into new carbon materials with adapted properties, capable of heating other materials indirectly. In this paper, the microwave heating of graphene as reinforcement of the lithium aluminosilicate (LAS) ceramics has been explored. LAS ceramics have a near-zero coefficient of thermal expansion and exhibit an effective and efficient heating by microwave. Nevertheless, we have found that the graphene did not show any significant response to the microwave radiation and, hence, the interaction as mechanical reinforcement with the LAS material is harmful. The possible benefits of graphene materials to microwave technology are widely known; however, the mechanism involved in the interaction of microwave radiation with ceramic-graphene composites with high dielectric loss factors has not been addressed earlier.
Properties Analysis of Asphalt Binders Containing Bayer Red Mud
Authors: Yao Liyang , Gao Wenying , Ma Xianwei , Fu Hao
Published: March 2020

In this work, related performances of asphalt binders with Bayer red mud powder (RMP) were studied. RMP replaced the traditional limestone powder (LSP) as a filler in asphalt binder. The replacement rates were 0%, 25%, 50%, 75%, and 100%, respectively. In this study, seven F/A (filler-to-asphalt, weight/weight) ratios for each of the fillers were selected: 0.3, 0.6, 0.9, 1.2, 1.5, 1.8, and 2.1. Penetration, softening point, rotational viscosity (RV), dynamic shear rheometry (DSR), and bending beam rheometry (BBR) tests were used to evaluate the properties of the asphalt binder. Penetration into the asphalt binder decreases linearly with increasing F/A ratio. Moreover, penetration of binder with RMP is lower than that of asphalt binder with LSP (RMP0), and among the five fillers tested, RMP100 showed most significant influence on penetration of the asphalt binder. The addition of RMP increases the softening point of the binder. DSR results show that the improvement in the high temperature performance is most significant after replacing 75% of the LSP with Bayer RMP. BBR results show that with increasing substitution of RMP for LSP, the creep stiffness (S) increased while the rate of change of S (m-value) declined. The low temperature performance of every asphalt binder was not enough to meet the Superpave requirements. In order to meet the Superpave requirements for S and m-values, the maximum F/A ratios of the five replacements corresponding to the fillers with 0%, 25%, 50%, 75%, and 100% RMP, were 1.3, 1.2, 1.1, 1.0 and 0.9, respectively. At 135 °C, rotational viscosity showed that RMP75 and RMP100 with a maximum F/A ratio of 1.1 are the best choices for asphalt binders, considering economic and construction requirements.
Prediction of RC Bridge Member Resistance Decreasing in Time under Various Conditions in Slovakia
Authors: Koteš Peter , Strieška Miroslav , Bahleda František , Bujňáková Petra
Published: March 2020

Reliability is one of the most significant requirements for structures given in Eurocodes. Thus, the specific level of safety, serviceability, and durability have to be satisfied to fulfill the reliability of structures. In the case of reinforced concrete (RC) members, the corrosion of reinforcement is not assumed in the stage of structure design, which is in contrast with the structures in service, where the corrosion of reinforcement can significantly decrease their diameter ø in time. In these cases, the moment resistance in time MRd(t) decreases during the designed lifetime Td of a structure. The corrosion speed is as a basis for the calculation of moment resistance in time MRd(t), i.e., a first-year corrosion rate rcorr and a corrosion model as well. The corrosion itself is a very complicated issue, so the first-year corrosion rate rcorr and also the corrosion model can be different under various conditions in Slovakia. The paper is focused not only to determine the corrosion speed (first-year corrosion rate rcorr and the corrosion model) and parametric study of the moment resistance in time MRd(t) under various conditions in Slovakia but also shows an overview on some parameters that may influence the corrosion process.
Predictive Modeling the Free Hydraulic Jumps Pressure through Advanced Statistical Methods
Authors: Mousavi Seyed Nasrollah , Júnior Renato Steinke , Teixeira Eder Daniel , Bocchiola Daniele , Nabipour Narjes , Mosavi Amir , Shamshirband Shahabodin
Published: March 2020

Pressure fluctuations beneath hydraulic jumps potentially endanger the stability of stilling basins. This paper deals with the mathematical modeling of the results of laboratory-scale experiments to estimate the extreme pressures. Experiments were carried out on a smooth stilling basin underneath free hydraulic jumps downstream of an Ogee spillway. From the probability distribution of measured instantaneous pressures, pressures with different probabilities could be determined. It was verified that maximum pressure fluctuations, and the negative pressures, are located at the positions near the spillway toe. Also, minimum pressure fluctuations are located at the downstream of hydraulic jumps. It was possible to assess the cumulative curves of pressure data related to the characteristic points along the basin, and different Froude numbers. To benchmark the results, the dimensionless forms of statistical parameters include mean pressures (P*m), the standard deviations of pressure fluctuations (σ*X), pressures with different non-exceedance probabilities (P*k%), and the statistical coefficient of the probability distribution (Nk%) were assessed. It was found that an existing method can be used to interpret the present data, and pressure distribution in similar conditions, by using a new second-order fractional relationships for σ*X, and Nk%. The values of the Nk% coefficient indicated a single mean value for each probability.
On the Smoothing of the Generalized Extreme Value Distribution Parameters Using Penalized Maximum Likelihood: A Case Study on UVB Radiation Maxima in the Mexico City Metropolitan Area
Authors: Aguirre-Salado Alejandro Ivan , Aguirre-Salado Carlos Arturo , Alvarado Ernesto , Santiago-Santos Alicia , Lancho-Romero Guillermo Arturo
Published: March 2020

This paper concerns the use and implementation of penalized maximum likelihood procedures to fitting smoothing functions of the generalized extreme value distribution parameters to analyze spatial extreme values of ultraviolet B (UVB) radiation across the Mexico City metropolitan area in the period 2000–2018. The model was fitted using a flexible semi-parametric approach and the parameters were estimated by the penalized maximum likelihood (PML) method. In order to investigate the performance of the model as well as the estimation method in the analysis of complex nonlinear trends for UVB radiation maxima, a simulation study was conducted. The results of the simulation study showed that penalized maximum likelihood yields better regularization to the model than the maximum likelihood estimates. We estimated return levels of extreme UVB radiation events through a nonstationary extreme value model using measurements of ozone (O3), nitrogen oxides (NOx), particles of 10 μm or less in diameter (PM10), carbon monoxide (CO), relative humidity (RH) and sulfur dioxide (SO2). The deviance statistics indicated that the nonstationary generalized extreme value (GEV) model adjusted was statistically better compared to the stationary model. The estimated smoothing functions of the location parameter of the GEV distribution on the spatial plane for different periods of time reveal the existence of well-defined trends in the maxima. In the temporal plane, a presence of temporal cyclic components oscillating over a weak linear component with a negative slope is noticed, while in the spatial plane, a weak nonlinear local trend is present on a plane with a positive slope towards the west, covering the entire study area. An explicit spatial estimate of the 25-year return period revealed that the more extreme risk levels are located in the western region of the study area.
A Fuzzy Multi-Criteria Evaluation Framework for Urban Sustainable Development
Authors: Wang Wei-Ming , Peng Hsiao-Han
Published: March 2020

With the rapid transformations of living environments, urban sustainable development has become an important global issue for urban growth and management. In order to effectively implement urban sustainable development, it is necessary to establish an operational action model based on its nature. This study first clarifies the core value of urban quality of life (QOL), and proposes the corresponding concept of Life–City. A variety of factors may affect the content of Life–City, and when assessing the objectives of sustainable development, there are uncertain properties and value judgments. Therefore, Life–City evaluation is a fuzzy multi-criteria decision analysis (FMCDA) problem. This study constructs the dimensions and the possible impact factors for urban QOL development. The fuzzy Delphi method (FDM) is employed to screen evaluation criteria and develop the overall evaluation framework. In order to effectively convert the subjective and perceptual issues in the framework into objective and quantitative processing, this study adopts the extent analysis method on fuzzy AHP (EAFAHP) to aggregate experts’ comments as empirical evaluation. The research results can convert the abstract concept of sustainability to the evaluation of Life–City specific operation, and serve as guidance for self-examination of current status and future policy development.