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Open AccessArticle
Image Processing Tool Quantifying Auto-Tempered Carbides in As-Quenched Low Carbon Martensitic Steels
Metals 2020, 10(2), 171; https://doi.org/10.3390/met10020171 (registering DOI) - 23 Jan 2020
Abstract
As-quenched low-carbon martensitic steels (<0.2 wt.% C) contain auto-tempered carbides. Auto-tempering improves the work hardening and upper-shelf impact energy; however, an efficient characterization method to determine the degree of auto-tempering has not been available. This paper demonstrates an efficient image processing tool that [...] Read more.
As-quenched low-carbon martensitic steels (<0.2 wt.% C) contain auto-tempered carbides. Auto-tempering improves the work hardening and upper-shelf impact energy; however, an efficient characterization method to determine the degree of auto-tempering has not been available. This paper demonstrates an efficient image processing tool that calculates the relative auto-tempered carbide fraction by analyzing scanning electron microscope micrographs. By the process of image segmentation, the qualitative volume fraction of auto-tempered carbides can be determined, and an associated color map produced, which distinguished the levels of auto-tempering. This image processing tool could become useful for the optimization of new low-carbon steel’s mechanical properties. Full article
Open AccessArticle
Empirical Evidence in Ecuador Between Economic Growth and Environmental Deterioration
Sustainability 2020, 12(3), 853; https://doi.org/10.3390/su12030853 (registering DOI) - 23 Jan 2020
Abstract
Currently, obtaining evidence of the correlation between economic growth and environmental deterioration is of great relevance. Due to an increase in economic activity, an increase in CO2 emissions and its possible effects on the current climate change is very worrying. The studies [...] Read more.
Currently, obtaining evidence of the correlation between economic growth and environmental deterioration is of great relevance. Due to an increase in economic activity, an increase in CO2 emissions and its possible effects on the current climate change is very worrying. The studies that analyze this correlation serve as a basis for the awareness of countries and the establishment of policies worldwide to curb such deterioration. The objective of this research is achieved through a panel data model and spatial econometric techniques to address the relationship between economic growth and environmental degradation in Ecuador. A regression model is proposed where the deterioration dependent variable is CO2 emissions, which is also an independent variable for the provincial gross value added. Poverty and inequality are considered as control variables in order to observe their effects on CO2 emission. The results are coherent with what is stated by the theory and describe an inverted U-shaped curve. They also show that the generation of pollutant emissions is directly related to the growth of the vehicle fleet and inversely related with the population’s schooling levels. The spatial effects are significant and the spatial impact multipliers indicate that the strongest direct and indirect effect is the one caused by the generation of car emissions per capita. This variable is relevant for the design of public policy aimed at improving environmental quality. Full article
Open AccessArticle
Discrimination of Naturally-Occurring 2-Arylbenzofurans as Cyclooxygenase-2 Inhibitors: Insights into the Binding Mode and Enzymatic Inhibitory Activity
Biomolecules 2020, 10(2), 176; https://doi.org/10.3390/biom10020176 (registering DOI) - 23 Jan 2020
Abstract
2-arylbenzofuran-containing compounds are chemical entities that can be naturally produced by several organisms. A wide-range of activities is described for several compounds of this kind and they are, therefore, valuable moieties for a lead finding from nature. Although there are in-vitro data about [...] Read more.
2-arylbenzofuran-containing compounds are chemical entities that can be naturally produced by several organisms. A wide-range of activities is described for several compounds of this kind and they are, therefore, valuable moieties for a lead finding from nature. Although there are in-vitro data about the activity of 2-arylbenzofuran-related compounds against cyclooxygenase (COX) enzymes, the molecular level of these COX-inhibiting constituents had not been deeply explored. Thus, 58 2-arylbenzofurans were initially screened through molecular docking within the active site of nine COX-2 crystal structures. The resulting docking scores were statistically analyzed and good reproducibility and convergence were found to discriminate the best-docked compounds. Discriminated compounds exhibited the best performance in molecular dynamics simulations as well as the most-favorable binding energies and the lowest in-vitro IC50 values for COX-2 inhibition. A three-dimensional quantitative activity-structure relationship (3D-QSAR) was also demonstrated, which showed some crucial structural requirements for enhanced enzyme inhibition. Therefore, four hits are proposed as lead structures for the development of COX-2 inhibitors based on 2-arylbenzofurans in further studies. Full article
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Open AccessArticle
Accelerated Life Test Method for the Doubly Truncated Burr Type XII Distribution
Mathematics 2020, 8(2), 162; https://doi.org/10.3390/math8020162 (registering DOI) - 23 Jan 2020
Abstract
The Burr type XII (BurrXII) distribution is very flexible for modeling and has earned much attention in the past few decades. In this study, the maximum likelihood estimation method and two Bayesian estimation procedures are investigated based on constant-stress accelerated life test (ALT) [...] Read more.
The Burr type XII (BurrXII) distribution is very flexible for modeling and has earned much attention in the past few decades. In this study, the maximum likelihood estimation method and two Bayesian estimation procedures are investigated based on constant-stress accelerated life test (ALT) samples, which are obtained from the doubly truncated three-parameter BurrXII distribution. Because computational difficulty occurs for maximum likelihood estimation method, two Bayesian procedures are suggested to estimate model parameters and lifetime quantiles under the normal use condition. A Markov Chain Monte Carlo approach using the Metropolis–Hastings algorithm via Gibbs sampling is built to obtain Bayes estimators of the model parameters and to construct credible intervals. The proposed Bayesian estimation procedures are simple for practical use, and the obtained Bayes estimates are reliable for evaluating the reliability of lifetime products based on ALT samples. Monte Carlo simulations were conducted to evaluate the performance of these two Bayesian estimation procedures. Simulation results show that the second Bayesian estimation procedure outperforms the first Bayesian estimation procedure in terms of bias and mean squared error when users do not have sufficient knowledge to set up hyperparameters in the prior distributions. Finally, a numerical example about oil-well pumps is used for illustration. Full article
(This article belongs to the Special Issue Statistical Simulation and Computation)
Open AccessArticle
Does the Source of Remittance Matter? Differentiated Effects of Earned and Unearned Remittances on Agricultural Productivity
Economies 2020, 8(1), 8; https://doi.org/10.3390/economies8010008 (registering DOI) - 23 Jan 2020
Abstract
This paper analyzes the effect of earned and unearned remittances on agricultural productivity in Nepal. This approach differs from the existing practice of studying the impact of total remittances on socio-economic outcomes. In particular, we disaggregate total remittances into earned and unearned remittances, [...] Read more.
This paper analyzes the effect of earned and unearned remittances on agricultural productivity in Nepal. This approach differs from the existing practice of studying the impact of total remittances on socio-economic outcomes. In particular, we disaggregate total remittances into earned and unearned remittances, and isolate their impacts on productivity—an individual household’s per labor-hour production of all agricultural output at the market value. Methodologically, we follow a three-stage least squares (3-SLS) approach to overcome the potential endogeneity concerns. We provide evidence that unearned remittances are more effective than earned remittances in increasing agricultural productivity. These results can be useful in understanding the migration-remittance-productivity nexus in Nepal as well as other similar socioeconomic societies from South Asia. Full article
(This article belongs to the Special Issue Productivity and Efficiency Analysis)
Open AccessArticle
Recrystallization of Single-Crystalline VO2 Microtube Arrays on V2O5 Substrate
Crystals 2020, 10(2), 66; https://doi.org/10.3390/cryst10020066 (registering DOI) - 23 Jan 2020
Abstract
Single-crystalline VO2 microtube arrays on V2O5 substrate were fabricated through a thermal oxidation route based on resistive heating V foil in air. Four sheets of as-fabricated single-crystalline VO2 microtube arrays on V2O5 substrate were then, [...] Read more.
Single-crystalline VO2 microtube arrays on V2O5 substrate were fabricated through a thermal oxidation route based on resistive heating V foil in air. Four sheets of as-fabricated single-crystalline VO2 microtube arrays on V2O5 substrate were then, respectively, heated to approximately 855 °C and 1660 °C to melt V2O5 or VO2. Thereafter, the melted V2O5 or VO2 was cooled rapidly or slowly to recrystallize the liquid V2O5 or VO2. The morphologies and phases of the recrystallization products were characterized by scanning electron microscopy and X-ray diffraction. This study proposes that the peak temperature of heating and the cooling rate are responsible for the recrystallization products of single-crystalline VO2 microtube arrays on V2O5 substrate. Full article
Open AccessArticle
Monitoring the Production of High Diffraction-Quality Crystals of Two Enzymes in Real Time Using In Situ Dynamic Light Scattering
Crystals 2020, 10(2), 65; https://doi.org/10.3390/cryst10020065 (registering DOI) - 23 Jan 2020
Abstract
The reproducible preparation of well-diffracting crystals is a prerequisite for every structural study based on crystallography. An instrument called XtalController has recently been designed that allows the monitoring of crystallization assays using dynamic light scattering and microscopy, and integrates piezo pumps to alter [...] Read more.
The reproducible preparation of well-diffracting crystals is a prerequisite for every structural study based on crystallography. An instrument called XtalController has recently been designed that allows the monitoring of crystallization assays using dynamic light scattering and microscopy, and integrates piezo pumps to alter the composition of the mother liquor during the experiment. We have applied this technology to study the crystallization of two enzymes, the CCA-adding enzyme of the psychrophilic bacterium Planococcus halocryophilus, and the lysozyme from hen egg white in the presence of a synthetic chemical nucleant. We were able to (i) detect early nucleation events and (ii) drive the crystallization system (through cycles of dissolution/crystallization) toward growth conditions yielding crystals with excellent diffraction properties. This technology opens a way to the rational production of samples for crystallography, ranging from nanocrystals for electron diffraction, microcrystals for serial or conventional X-ray diffraction, to larger crystals for neutron diffraction. Full article
(This article belongs to the Special Issue Novel Strategies for Improved Protein Crystallization)
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Open AccessArticle
Characterization of Fresh and Cured Properties of Polymer Concretes Based on Two Metallurgical Wastes
Appl. Sci. 2020, 10(3), 825; https://doi.org/10.3390/app10030825 (registering DOI) - 23 Jan 2020
Abstract
Polyester polymer concretes can substitute conventional concretes based on their usually good mechanical strength, adequate physical properties, and high resistance against aggressive chemical environments. They also show a high potential for using recycled targets in their manufacturing. This paper analyzes the fresh and [...] Read more.
Polyester polymer concretes can substitute conventional concretes based on their usually good mechanical strength, adequate physical properties, and high resistance against aggressive chemical environments. They also show a high potential for using recycled targets in their manufacturing. This paper analyzes the fresh and cured properties of polyester polymer concretes containing two metallurgical wastes, namely: ladle slag and alumina filler. Both targets require a higher resin dosage than sand. The standard consistency test showed a low representativeness of the recycled fresh mixes’ workability. The ladle slag and alumina filler samples showed a higher length plastic shrinkage than those containing sand. All of the targets obtained cured density values in the range of 1.589–1.912 g/cm3. From a mechanical point of view, the sand and alumina filler containing polyester polymer concretes reached 11.02 and 10.93 kN, respectively, of flexural strength, while the ladle slag samples showed the best result with 19.31 kN. In the compressive strength test, the sand and alumina filler combinations reached 106.16 and 104.21 MPa, respectively, while the ladle slag achieved 160.48 MPa. The flexural and compressive elasticity modulus showed similar trends related to the resin content. Full article
(This article belongs to the Special Issue Recycling Waste in Construction Materials)
Open AccessFeature PaperArticle
Microstructure and Rutherford Backscattering Spectrometry of Hard/Lubricant Mo-Ti-Al-N Multilayered Coatings Prepared by Multi-Arc Ion Plating at Low Substrate Rotation
Coatings 2020, 10(2), 101; https://doi.org/10.3390/coatings10020101 (registering DOI) - 23 Jan 2020
Abstract
To develop the hard and self-lubricating coatings applied for the industrial dry-cutting and die-casting machining tool fields, a series of MoTiAlN/MoN/Mo multilayered coatings were deposited on Si substrates under low substrate rotation by cathodic multi-arc ion plating. XRD, SEM, TEM, RBS, nanoindentation, and [...] Read more.
To develop the hard and self-lubricating coatings applied for the industrial dry-cutting and die-casting machining tool fields, a series of MoTiAlN/MoN/Mo multilayered coatings were deposited on Si substrates under low substrate rotation by cathodic multi-arc ion plating. XRD, SEM, TEM, RBS, nanoindentation, and tribology tester were used to monitor the phase structure, morphology, component, nanohardness, and friction coefficient of the coatings. It was found that the coatings deposited at various substrate rotations comprised paramount cubic B1 structure TiAlN and Mo2N phases. The micrographs confirmed that the mean modulation period and total physical thickness of multilayered TiAlN/Mo2N coatings with a sharp interface fabricated at 2 revolutions per minute (rpm) were 26 nm and 1.15 μm. The mean nanohardness and friction coefficient were ca. 30 GPa and 0.4, respectively. RBS results along with the SIMNRA code allowed to estimate the total atomic concentrations and the physical thickness of individual sublayer as well as the modulation period of multilayered coatings, which demonstrated an efficiency of this approach for characterization of nano-multilayered structures. Full article
Open AccessArticle
A Comparative Study on Cooling Period Thermal Comfort Assessment in Modern Open Office Landscape in Estonia
Atmosphere 2020, 11(2), 127; https://doi.org/10.3390/atmos11020127 (registering DOI) - 23 Jan 2020
Abstract
Local thermal comfort and draught rate has been studied widely. There has been more meaningful research performed in controlled boundary condition situations than in actual work environments involving occupants. Thermal comfort conditions in office buildings in Estonia have been barely investigated in the [...] Read more.
Local thermal comfort and draught rate has been studied widely. There has been more meaningful research performed in controlled boundary condition situations than in actual work environments involving occupants. Thermal comfort conditions in office buildings in Estonia have been barely investigated in the past. In this paper, the results of thermal comfort and draught rate assessment in five office buildings in Tallinn are presented and discussed. Studied office landscapes vary in heating, ventilation and cooling system parameters, room units, and elements. All sample buildings were less than six years old, equipped with dedicated outdoor air ventilation system and room conditioning units. The on-site measurements consisted of thermal comfort and draught rate assessment with indoor climate questionnaire. The purpose of the survey is to assess the correspondence between heating, ventilation and cooling system design, and the actual situation. Results show, whether and in what extent the standard-based criteria for thermal comfort is suitable for actual usage of the occupants. Preferring one room conditioning unit type or system may not guarantee better thermal environment without draught. Although some heating, ventilation and cooling systems observed in this study should create the prerequisites for ensuring more comfort, results show that this is not the case for all buildings in this study. Full article
(This article belongs to the Special Issue Indoor Thermal Comfort)
Open AccessReview
Recent Advancements in Crystalline Pb-Free Halide Double Perovskites
Crystals 2020, 10(2), 62; https://doi.org/10.3390/cryst10020062 (registering DOI) - 23 Jan 2020
Abstract
Lead halide perovskites have gained more and more attention because of their ease of synthesis and excellent photoelectric properties including a large absorption coefficient, long carrier lifetime, long carrier diffusion length, and high carrier mobility. However, their toxicity, instability, and phase degradation in [...] Read more.
Lead halide perovskites have gained more and more attention because of their ease of synthesis and excellent photoelectric properties including a large absorption coefficient, long carrier lifetime, long carrier diffusion length, and high carrier mobility. However, their toxicity, instability, and phase degradation in ambient environments impede their large-scale applications. To address these concerns, it is desirable to find stable alternative halide perovskites without toxicity and with comparable optoelectronic properties to lead-based perovskites. Over the years, a considerable number of lead-free halide perovskites have been added to this family of materials, including A2B'B''X6, A2BX6, and A3B2X9 type perovskites. Among these, double perovskites with the general formula A2B'B''X6 are deemed to be a potential alternative to lead halide perovskites as they possess good stability under ambient conditions and excellent optoelectronic properties. In this review, recent progress in exploring Pb-free halide double perovskites is highlighted. The synthesis, composition-tuning, physical properties, and applications of representative 3D, 2D, and nanocrystal A2B'B''X6 double perovskites are introduced. In addition, perspectives about current challenges and solutions in this field are also provided. Full article
Open AccessArticle
Design of Low-Glared LED Rear Light of Automotive for EU ECE Regulation by Use of Optimized Micro-Prisms Array
Crystals 2020, 10(2), 63; https://doi.org/10.3390/cryst10020063 (registering DOI) - 23 Jan 2020
Abstract
A new LED rear light for automotives is proposed and demonstrated for EU ECE R07 regulation. The full rear light is a combination of a position lamp and a braking lamp, and LED light bars and micro-prisms are involved as their essential components. [...] Read more.
A new LED rear light for automotives is proposed and demonstrated for EU ECE R07 regulation. The full rear light is a combination of a position lamp and a braking lamp, and LED light bars and micro-prisms are involved as their essential components. The micro-prisms are applied to homogenize the output of the rear light to decrease glare and accomplish EU ECE standard. Through experiments, it is shown that EU ECE R07 regulation can be met in the proposed rear light, and 12% (position lamps) and 26.5% (braking lamps) higher candela can be enhanced after the optimization of micro-prisms. Full article
(This article belongs to the Special Issue Advanced LED Solid-state Lighting Optics)
Open AccessArticle
Frequently Consumed Foods and Energy Contributions among Food Secure and Insecure U.S. Children and Adolescents
Nutrients 2020, 12(2), 304; https://doi.org/10.3390/nu12020304 (registering DOI) - 23 Jan 2020
Abstract
Food insecurity is associated with nutritional risk in children. This study identified and compared the most frequently consumed foods, beverages, and food groups and their contributions to energy intake among U.S. children and adolescents (6–11, 12–17 years) by food security status. Dietary intake [...] Read more.
Food insecurity is associated with nutritional risk in children. This study identified and compared the most frequently consumed foods, beverages, and food groups and their contributions to energy intake among U.S. children and adolescents (6–11, 12–17 years) by food security status. Dietary intake from the day-1, 24-h dietary recall, and household child food security status were analyzed in the 2007–2014 National Health and Nutrition Examination Survey (n = 8123). Foods and beverages were classified into food categories, ranked, and compared by weighted proportional frequency and energy contribution for food security groups by age. Significant differences between household child food security groups were determined using the Rao-Scott modified chi-square statistic. The weighted proportional frequency of beverages (including diet, sweetened, juice, coffee, and tea) and their energy was significantly higher among food insecure compared with food secure while the reverse was true for water frequency among 12–17 years. Beverage and mixed dish frequency were higher among food insecure compared with food secure 6–11 years while the reverse was true for frequency and energy from snacks. Frequency-differentiated intake patterns for beverages and snacks by food security across age groups may inform dietary recommendations, population-specific dietary assessment tools, interventions, and policy for food insecure children. Full article
(This article belongs to the Special Issue Nutrition among Vulnerable Populations)
Open AccessArticle
The Impact of Coconut Oil and Epigallocatechin Gallate on the Levels of IL-6, Anxiety and Disability in Multiple Sclerosis Patients
Nutrients 2020, 12(2), 305; https://doi.org/10.3390/nu12020305 (registering DOI) - 23 Jan 2020
Abstract
Background: Due to the inflammatory nature of multiple sclerosis (MS), interleukin 6 (IL-6) is high in blood levels, and it also increases the levels of anxiety related to functional disability. Epigallocatechin gallate (EGCG) decreases IL-6, which could be enhanced by the anti-inflammatory effect [...] Read more.
Background: Due to the inflammatory nature of multiple sclerosis (MS), interleukin 6 (IL-6) is high in blood levels, and it also increases the levels of anxiety related to functional disability. Epigallocatechin gallate (EGCG) decreases IL-6, which could be enhanced by the anti-inflammatory effect of high ketone bodies after administering coconut oil (both of which are an anxiolytic). Therefore, the aim of this study was to assess the impact of coconut oil and EGCG on the levels of IL-6, anxiety and functional disability in patients with MS. Methods: A pilot study was conducted for four months with 51 MS patients who were randomly divided into an intervention group and a control group. The intervention group received 800 mg of EGCG and 60 mL of coconut oil, and the control group was prescribed a placebo. Both groups followed the same isocaloric Mediterranean diet. State and trait anxiety were determined before and after the study by means of the State-Trait Anxiety Inventory (STAI). In addition, IL-6 in serum was measured using the ELISA technique and functional capacity was determined with the Expanded Disability Status Scale (EDSS) and the body mass index (BMI). Results: State anxiety and functional capacity decreased in the intervention group and IL-6 decreased in both groups. Conclusions: EGCG and coconut oil improve state anxiety and functional capacity. In addition, a decrease in IL-6 is observed in patients with MS, possibly due to the antioxidant capacity of the Mediterranean diet and its impact on improving BMI. Full article
(This article belongs to the Special Issue Nutrition and Fitness: Mental Health)
Open AccessArticle
Sex-Based Differences in the Quality of Life of Elderly Koreans with Chronic Musculoskeletal Pain
Int. J. Environ. Res. Public Health 2020, 17(3), 743; https://doi.org/10.3390/ijerph17030743 (registering DOI) - 23 Jan 2020
Abstract
In this study, we constructed a structural equation model (SEM) for predicting the quality of life (QOL) in elderly Koreans with chronic musculoskeletal pain (CMP) and examined the differences between sexes. Data were earlier collected in a prior study of 307 participants (101 [...] Read more.
In this study, we constructed a structural equation model (SEM) for predicting the quality of life (QOL) in elderly Koreans with chronic musculoskeletal pain (CMP) and examined the differences between sexes. Data were earlier collected in a prior study of 307 participants (101 men and 206 women) with CMP, aged 65 years and above, who used geriatric welfare centers located in two cities. The effects of pain, functional limitation, perceived health status, pain coping, and social support on the QOL were estimated with a multigroup SEM. For both men and women, the results show sequential causality from pain to functional limitation, perceived health status, and QOL. However, the relationships among pain, pain coping, functional limitation, and QOL differ between men and women. The multigroup SEM provides a better understanding of the sex differences in the QOL of elderly with CMP. The results suggest that in order to improve QOL among the elderly with CMP, a customized strategy should be applied that takes into account differences between the sexes. Full article
(This article belongs to the Section Public Health Statistics and Risk Assessment)
Open AccessFeature PaperReview
MiRNAs as Novel Adipokines: Obesity-Related Circulating MiRNAs Influence Chemosensitivity in Cancer Patients
Non-Coding RNA 2020, 6(1), 5; https://doi.org/10.3390/ncrna6010005 (registering DOI) - 23 Jan 2020
Abstract
Adipose tissue is an endocrine organ, capable of regulating distant physiological processes in other tissues via the release of adipokines into the bloodstream. Recently, circulating adipose-derived microRNAs (miRNAs) have been proposed as a novel class of adipokine, due to their capacity to regulate [...] Read more.
Adipose tissue is an endocrine organ, capable of regulating distant physiological processes in other tissues via the release of adipokines into the bloodstream. Recently, circulating adipose-derived microRNAs (miRNAs) have been proposed as a novel class of adipokine, due to their capacity to regulate gene expression in tissues other than fat. Circulating levels of adipokines are known to be altered in obese individuals compared with typical weight individuals and are linked to poorer health outcomes. For example, obese individuals are known to be more prone to the development of some cancers, and less likely to achieve event-free survival following chemotherapy. The purpose of this review was twofold; first to identify circulating miRNAs which are reproducibly altered in obesity, and secondly to identify mechanisms by which these obesity-linked miRNAs might influence the sensitivity of tumors to treatment. We identified 8 candidate circulating miRNAs with altered levels in obese individuals (6 increased, 2 decreased). A second literature review was then performed to investigate if these candidates might have a role in mediating resistance to cancer treatment. All of the circulating miRNAs identified were capable of mediating responses to cancer treatment at the cellular level, and so this review provides novel insights which can be used by future studies which aim to improve obese patient outcomes. Full article
(This article belongs to the Special Issue Non-Coding RNAs: Variations and Disease)

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