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Open AccessArticle
Optical System Design of a Wide Field-Of-View Camera for the Characterization of Earth’s Reflected Solar Radiation
Remote Sens. 2020, 12(16), 2556; https://doi.org/10.3390/rs12162556 (registering DOI) - 08 Aug 2020
Abstract
We report on the conceptual design of a new wide field-of-view shortwave camera, for measuring Earth’s reflected solar radiation. The camera comprises a commercial-off-the-shelf CMOS sensor, and a custom-designed wide field-of-view lens system with an opening angle of 140. The estimated effective nadir [...] Read more.
We report on the conceptual design of a new wide field-of-view shortwave camera, for measuring Earth’s reflected solar radiation. The camera comprises a commercial-off-the-shelf CMOS sensor, and a custom-designed wide field-of-view lens system with an opening angle of 140. The estimated effective nadir resolution is 2.2 km. The simulated stand-alone random error of the broadband albedo is 3%. The camera is suited for integration within 1U of a CubeSat. Full article
Open AccessArticle
Identification of High-Risk Areas for the Spread of Highly Pathogenic Avian Influenza in Central Luzon, Philippines
Vet. Sci. 2020, 7(3), 107; https://doi.org/10.3390/vetsci7030107 (registering DOI) - 08 Aug 2020
Abstract
Highly pathogenic avian influenza virus (HPAIV) is a major problem in the poultry industry. It is highly contagious and is associated with a high mortality rate. The Philippines experienced an outbreak of avian influenza (AI) in 2017. As there is always a risk [...] Read more.
Highly pathogenic avian influenza virus (HPAIV) is a major problem in the poultry industry. It is highly contagious and is associated with a high mortality rate. The Philippines experienced an outbreak of avian influenza (AI) in 2017. As there is always a risk of re-emergence, efforts to manage disease outbreaks should be optimal. Linked to this is the need for an effective surveillance procedure to capture disease outbreaks at their early stage. Risk-based surveillance is the most effective and economical approach to outbreak management. This study evaluated the potential of commercial poultry farms in Central Luzon to transmit HPAI by calculating their respective reproductive ratios ($R0$). The reproductive number for each farm is based on the spatial kernel and the infectious period. A risk map has been created based on the calculated R0. There were 882 (76.63%) farms with $R0$ < 1. Farms with $R0$ ≥ 1 were all located in Pampanga Province. These farms were concentrated in the towns of San Luis (n = 12) and Candaba (n = 257). This study demonstrates the utility of mapping farm-level $R0$ estimates for informing HPAI risk management activities. Full article
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Open AccessArticle
Modeling the Diversity of Epithelial Ovarian Cancer through Ten Novel Well Characterized Cell Lines Covering Multiple Subtypes of the Disease
Cancers 2020, 12(8), 2222; https://doi.org/10.3390/cancers12082222 (registering DOI) - 08 Aug 2020
Abstract
Cancer cell lines are amongst the most important pre-clinical models. In the context of epithelial ovarian cancer, a highly heterogeneous disease with diverse subtypes, it is paramount to study a wide panel of models in order to draw a representative picture of the [...] Read more.
Cancer cell lines are amongst the most important pre-clinical models. In the context of epithelial ovarian cancer, a highly heterogeneous disease with diverse subtypes, it is paramount to study a wide panel of models in order to draw a representative picture of the disease. As this lethal gynaecological malignancy has seen little improvement in overall survival in the last decade, it is all the more pressing to support future research with robust and diverse study models. Here, we describe ten novel spontaneously immortalized patient-derived ovarian cancer cell lines, detailing their respective mutational profiles and gene/biomarker expression patterns, as well as their in vitro and in vivo growth characteristics. Eight of the cell lines were classified as high-grade serous, while two were determined to be of the rarer mucinous and clear cell subtypes, respectively. Each of the ten cell lines presents a panel of characteristics reflective of diverse clinically relevant phenomena, including chemotherapeutic resistance, metastatic potential, and subtype-associated mutations and gene/protein expression profiles. Importantly, four cell lines formed subcutaneous tumors in mice, a key characteristic for pre-clinical drug testing. Our work thus contributes significantly to the available models for the study of ovarian cancer, supplying additional tools to better understand this complex disease. Full article
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Open AccessArticle
On the Role of the Cathode for the Electro-Oxidation of Perfluorooctanoic Acid
Catalysts 2020, 10(8), 902; https://doi.org/10.3390/catal10080902 (registering DOI) - 08 Aug 2020
Abstract
Perfluorooctanoic acid (PFOA), C7F15COOH, has been widely employed over the past fifty years, causing an environmental problem because of its dispersion and low biodegradability. Furthermore, the high stability of this molecule, conferred by the high strength of the C-F [...] Read more.
Perfluorooctanoic acid (PFOA), C7F15COOH, has been widely employed over the past fifty years, causing an environmental problem because of its dispersion and low biodegradability. Furthermore, the high stability of this molecule, conferred by the high strength of the C-F bond makes it very difficult to remove. In this work, electrochemical techniques are applied for PFOA degradation in order to study the influence of the cathode on defluorination. For this purpose, boron-doped diamond (BDD), Pt, Zr, and stainless steel have been tested as cathodes working with BDD anode at low electrolyte concentration (3.5 mM) to degrade PFOA at 100 mg/L. Among these cathodic materials, Pt improves the defluorination reaction. The electro-degradation of a PFOA molecule starts by a direct exchange of one electron at the anode and then follows a complex mechanism involving reaction with hydroxyl radicals and adsorbed hydrogen on the cathode. It is assumed that Pt acts as an electrocatalyst, enhancing PFOA defluorination by the reduction reaction of perfluorinated carbonyl intermediates on the cathode. The defluorinated intermediates are then more easily oxidized by HO radicals. Hence, high mineralization (xTOC: 76.1%) and defluorination degrees (xF: 58.6%) were reached with Pt working at current density j = 7.9 mA/cm2. This BDD-Pt system reaches a higher efficiency in terms of defluorination for a given electrical charge than previous works reported in literature. Influence of the electrolyte composition and initial pH are also explored. Full article
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Open AccessArticle
Ki67 and PR in Patients Treated with CDK4/6 Inhibitors: A Real-World Experience
Diagnostics 2020, 10(8), 573; https://doi.org/10.3390/diagnostics10080573 (registering DOI) - 08 Aug 2020
Abstract
: CDK4/6 inhibitors (CDK4/6i) are recommended in patients with estrogen receptor (ER)-positive, HER2-negative advanced breast cancer (ABC). Up to now, no prognostic biomarkers have been identified in this setting. We retrospectively analyzed the expression of progesterone receptor (PR) and Ki67, assessed by immunohistochemistry, [...] Read more.
: CDK4/6 inhibitors (CDK4/6i) are recommended in patients with estrogen receptor (ER)-positive, HER2-negative advanced breast cancer (ABC). Up to now, no prognostic biomarkers have been identified in this setting. We retrospectively analyzed the expression of progesterone receptor (PR) and Ki67, assessed by immunohistochemistry, in 71 ABC patients treated with CDK4/6i and analyzed the impact of these markers on progression-free survival (PFS). The majority of patients 63/71 (88.7%) received palbociclib, 4 (5.6%) received ribociclib, and 4 (5.6%) received abemaciclib. A higher median value of Ki67 was observed in cases undergoing second-line treatment (p = 0.047), whereas the luminal B subtype was more prevalent (p = 0.005). In the univariate analysis of the first-line setting, luminal A subtype showed a trend towards a correlation with a longer PFS (p = 0.053). A higher continuous Ki67 value led to a significantly shorter PFS. When the interaction between pathological characteristics and line of treatment was considered, luminal B subtype showed a significantly (p = 0.043) worse outcome (Hazard Ratio (HR) 2.84; 1.03–7.82 95% Confidence Interval (CI)). PFS in patients undergoing endocrine therapy plus CDK4/6i was inversely correlated with Ki67 expression but not with PR, suggesting that tumor proliferation has a greater impact on cell cycle inhibitors combined with endocrine therapy than PR expression. Full article
Open AccessArticle
Enhanced Visible Light Active WO3 Thin Films Toward Air Purification: Effect of the Synthesis Conditions
Materials 2020, 13(16), 3506; https://doi.org/10.3390/ma13163506 (registering DOI) - 08 Aug 2020
Abstract
Taking our current environmental situation in the world into consideration, people should face growing problems of air and water pollution. Heterogeneous photocatalysis is a highly promising tool to improve both air and water quality through decomposition/mineralization of contaminants directly into harmless CO2 [...] Read more.
Taking our current environmental situation in the world into consideration, people should face growing problems of air and water pollution. Heterogeneous photocatalysis is a highly promising tool to improve both air and water quality through decomposition/mineralization of contaminants directly into harmless CO2 and H2O under ambient conditions. In this contribution, we focused on the synthesis of self-assembly WO3 thin films via an electrochemical approach in the aqueous electrolyte containing fluoride ions toward air purification. The effect of preparation conditions such as applied potential (10–50 V), anodization time (15–120 min), concentration of H2SO4 (0.5–1.5 M) and NaF (0.1–1.0 wt.%) on the morphology, photocurrent response, and photocatalytic activity addressed to removal of air pollutant in the presence of as-prepared WO3 samples were thoroughly examined and presented. The results revealed the growth of nanoplatelets and their gradual transformation into flower-like structures. The oxide layers and platelet thickness of the WO3 samples were found to be proportionally related with the synthesis conditions. The photocatalytic ability toward air purification was evaluated by degradation of toluene from air mixture using low-powered LEDs as an irradiation source (λmax = 415 nm). The highest photoactivity was achieved in presence of the sample which possessed a well-ordered, regular shape and repeatable distribution of flower buds (100% of degradation). The results have confirmed that the oxide layer thickness of the anodic WO3 significantly affected the photocatalytic activity, which increased with the increasing thickness of WO3 (to 1.05 μm) and then had a downward trend. The photocurrent response evidenced that the well-organized sample had the highest ability in photocurrent generation under UV-Vis and Vis irradiation. Finally, a possible growth mechanism of WO3 NFs was also discussed. Full article
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Open AccessArticle
Measuring the Normal Stress Distribution Acting on a Locked-Wheel of Push–Pull Locomotion Rovers via a Wheel Sensor System
Sensors 2020, 20(16), 4434; https://doi.org/10.3390/s20164434 (registering DOI) - 08 Aug 2020
Abstract
The resistance force generated when the locked-wheel acts on the soil is critical for deciding the traveling performance of push–pull locomotion. The resistance force depends on the tangential force of the sliding soil wedge beneath the wheel, and the tangential force depends on [...] Read more.
The resistance force generated when the locked-wheel acts on the soil is critical for deciding the traveling performance of push–pull locomotion. The resistance force depends on the tangential force of the sliding soil wedge beneath the wheel, and the tangential force depends on the forces of the soil and the wheel perpendicular to the tangential direction. Hence, the normal stress distribution of the locked-wheel can affect the resistance force. Previous studies indicated different insights that describe either a uniform or non-uniform shape of the normal stress distribution. The distribution of the locked-wheel still needs to be examined experimentally. This study measured the normal stress distribution using the wheel sensor system, and the variation of the contact area and slip surface beneath the wheel were also observed in PIV analysis. Those results showed that the normal stress distribution was non-uniform along the wheel contact area, and the change of the distribution was confirmed with the change of the contact area and slip surface. Then, the resistance force calculated by a preliminary model based on the measured data was compared with the total resistance force of the wheel measured by a separate sensor. This comparison provided a theoretical consideration for the measured data. Full article
Open AccessReview
Polymyxins and Bacterial Membranes: A Review of Antibacterial Activity and Mechanisms of Resistance
Membranes 2020, 10(8), 181; https://doi.org/10.3390/membranes10080181 (registering DOI) - 08 Aug 2020
Abstract
Following their initial discovery in the 1940s, polymyxin antibiotics fell into disfavor due to their potential clinical toxicity, especially nephrotoxicity. However, the dry antibiotic development pipeline, together with the rising global prevalence of infections caused by multidrug-resistant (MDR) Gram-negative bacteria have both rejuvenated [...] Read more.
Following their initial discovery in the 1940s, polymyxin antibiotics fell into disfavor due to their potential clinical toxicity, especially nephrotoxicity. However, the dry antibiotic development pipeline, together with the rising global prevalence of infections caused by multidrug-resistant (MDR) Gram-negative bacteria have both rejuvenated clinical interest in these polypeptide antibiotics. Parallel to the revival of their use, investigations into the mechanisms of action and resistance to polymyxins have intensified. With an initial known effect on biological membranes, research has uncovered the detailed molecular and chemical interactions that polymyxins have with Gram-negative outer membranes and lipopolysaccharide structure. In addition, genetic and epidemiological studies have revealed the basis of resistance to these agents. Nowadays, resistance to polymyxins in MDR Gram-negative pathogens is well elucidated, with chromosomal as well as plasmid-encoded, transferrable pathways. The aims of the current review are to highlight the important chemical, microbiological, and pharmacological properties of polymyxins, to discuss their mechanistic effects on bacterial membranes, and to revise the current knowledge about Gram-negative acquired resistance to these agents. Finally, recent research, directed towards new perspectives for improving these old agents utilized in the 21st century, to combat drug-resistant pathogens, is summarized. Full article
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Open AccessArticle
NIR Hyperspectral Imaging Technology Combined with Multivariate Methods to Identify Shrimp Freshness
Appl. Sci. 2020, 10(16), 5498; https://doi.org/10.3390/app10165498 (registering DOI) - 08 Aug 2020
Abstract
In this study, a hyperspectral imaging system of 866.4–1701.0 nm, combined with a variety of spectral processing methods were adopted to identify shrimp freshness. To gain the optimal model combination, three preprocessing methods (Savitzky-Golay first derivative (SG1), multivariate scatter correction (MSC), and standard [...] Read more.
In this study, a hyperspectral imaging system of 866.4–1701.0 nm, combined with a variety of spectral processing methods were adopted to identify shrimp freshness. To gain the optimal model combination, three preprocessing methods (Savitzky-Golay first derivative (SG1), multivariate scatter correction (MSC), and standard normal variate (SNV)), three characteristic wavelength extraction algorithms (random frog algorithm (RFA), uninformative variables elimination (UVE), and competitive adaptive reweighted sampling (CARS)), and four discriminant models (partial least squares discrimination analysis (PLS-DA), least squares support vector machine (LSSVM), random forest (RF), and extreme learning machine (ELM)) were employed for experimental study. First of all, due to the full wavelength modeling analysis, three preprocessing methods were utilized to preprocess the original spectral data. The analysis showed that the spectral data processed by the SNV method had the best performance among the four discriminant models. Secondly, due to the characteristic wavelength modeling analysis, three characteristic wavelength extraction algorithms were utilized to extract the characteristic wavelength of the SNV-processed spectral data. It was found that the CARS algorithm achieved the best performance among the three characteristic wavelength extraction algorithms, and the combining adoption of the ELM model and different characteristic wavelength extraction algorithms obtained the best results. Therefore, the model based on SNV-CARS-ELM obtained the best performance and was elected as the optimal model. Lastly, for accurately and explicitly displaying the refrigeration days of shrimps, the original hyperspectral images of shrimps were substituted into the SNV-CARS-ELM model, thus obtaining the general classification accuracy of 97.92%, and the object-wise method was used to visualize the classification results. As a result, the method proposed in this study can effectively detect the freshness of shrimps. Full article
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Open AccessReview
Correlation between Exogenous Compounds and the Horizontal Transfer of Plasmid-Borne Antibiotic Resistance Genes
Microorganisms 2020, 8(8), 1211; https://doi.org/10.3390/microorganisms8081211 (registering DOI) - 08 Aug 2020
Abstract
The global spread of antibiotic resistance has posed a serious threat to public healthcare and undermined decades of progress made in the fight against bacterial infections. It has been demonstrated that the lack of novel effective antibiotics and rapid spread of antibiotic resistance [...] Read more.
The global spread of antibiotic resistance has posed a serious threat to public healthcare and undermined decades of progress made in the fight against bacterial infections. It has been demonstrated that the lack of novel effective antibiotics and rapid spread of antibiotic resistance genes via horizontal transfer in the ecosystem are mainly responsible for this crisis. Notably, plasmid-mediated horizontal transfer of antibiotic resistance genes (ARGs) is recognized as the most dominant dissemination pathway of ARGs in humans, animals and environmental settings. Antibiotic selective pressure has always been regarded as one of the crucial contributors to promoting the dissemination of antibiotic resistance through horizontal gene transfer (HGT). However, the roles of exogenous compounds and particularly non-antibiotic drugs in the spread of ARGs are still underappreciated. In this review, we first summarize the major pathways of HGT in bacteria, including conjugation, transformation, transduction and vesiduction. Subsequently, an overview of these compounds capable of promoting the HGT is presented, which guides to the formulation of more reasonable dosing regimens and drug residue standards in clinical practice. By contrast, these compounds that display an inhibition effect on HGT are also highlighted, which provides a unique strategy to minimize the spread of ARGs. Lastly, we discuss the implementations and challenges in bringing these HGT inhibitors into clinical trials. Full article
(This article belongs to the Special Issue Antimicrobial Resistance: From the Environment to Human Health)
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Open AccessArticle
Modulation and Protection Effects of Antioxidant Compounds against Oxidant Induced Developmental Toxicity in Zebrafish
Antioxidants 2020, 9(8), 721; https://doi.org/10.3390/antiox9080721 (registering DOI) - 08 Aug 2020
Abstract
The antioxidant effect of compounds is regularly evaluated by in vitro assays that do not have the capability to predict in vivo protective activity or to determine their underlying mechanisms of action. The aim of this study was to develop an experimental system [...] Read more.
The antioxidant effect of compounds is regularly evaluated by in vitro assays that do not have the capability to predict in vivo protective activity or to determine their underlying mechanisms of action. The aim of this study was to develop an experimental system to evaluate the in vivo protective effects of different antioxidant compounds, based on the zebrafish embryo test. Zebrafish embryos were exposed to tert-butyl hydroperoxide (tBOOH), tetrachlorohydroquinone (TCHQ) and lipopolysaccharides from Escherichia coli (LPS), chemicals that are known inducers of oxidative stress in zebrafish. The developmental toxic effects (lethality or dysmorphogenesis) induced by these chemicals were modulated with n-acetyl l-cysteine and Nω-nitro l-arginine methyl ester hydrochloride, dimethyl maleate and dl-buthionine sulfoximine in order to validate the oxidant mechanism of oxidative stress inducers. The oxidant effects of tBOOH, TCHQ, and LPS were confirmed by the determination of significant differences in the comparison between the concentration–response curves of the oxidative stress inducers and of the modulators of antioxidant status. This concept was also applied to the study of the effects of well-known antioxidants, such as vitamin E, quercetin, and lipoic acid. Our results confirm the zebrafish model as an in vivo useful tool to test the protective effects of antioxidant compounds. Full article
(This article belongs to the Special Issue Oxidative Stress Modulators and Functional Foods)
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Open AccessReview
Gene Therapy in Rare Respiratory Diseases: What Have We Learned So Far?
J. Clin. Med. 2020, 9(8), 2577; https://doi.org/10.3390/jcm9082577 (registering DOI) - 08 Aug 2020
Abstract
Gene therapy is an alternative therapy in many respiratory diseases with genetic origin and currently without curative treatment. After five decades of progress, many different vectors and gene editing tools for genetic engineering are now available. However, we are still a long way [...] Read more.
Gene therapy is an alternative therapy in many respiratory diseases with genetic origin and currently without curative treatment. After five decades of progress, many different vectors and gene editing tools for genetic engineering are now available. However, we are still a long way from achieving a safe and efficient approach to gene therapy application in clinical practice. Here, we review three of the most common rare respiratory conditions—cystic fibrosis (CF), alpha-1 antitrypsin deficiency (AATD), and primary ciliary dyskinesia (PCD)—alongside attempts to develop genetic treatment for these diseases. Since the 1990s, gene augmentation therapy has been applied in multiple clinical trials targeting CF and AATD, especially using adeno-associated viral vectors, resulting in a good safety profile but with low efficacy in protein expression. Other strategies, such as non-viral vectors and more recently gene editing tools, have also been used to address these diseases in pre-clinical studies. The first gene therapy approach in PCD was in 2009 when a lentiviral transduction was performed to restore gene expression in vitro; since then, transcription activator-like effector nucleases (TALEN) technology has also been applied in primary cell culture. Gene therapy is an encouraging alternative treatment for these respiratory diseases; however, more research is needed to ensure treatment safety and efficacy. Full article
(This article belongs to the Special Issue Rare Respiratory Diseases: A Personal and a Public Health Problem)
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Open AccessBrief Report
Remaining Useful Life Prediction of an IGBT Module in Electric Vehicles Statistical Analysis
Symmetry 2020, 12(8), 1325; https://doi.org/10.3390/sym12081325 (registering DOI) - 08 Aug 2020
Abstract
The whole life cycle of an insulated gate bipolar transistor (IGBT) is a kind of asymmetry process, while the whole life cycles of a set of IGBTs can be regarded as a symmetry process. Modelling these symmetry characteristics of the IGBT life cycles [...] Read more.
The whole life cycle of an insulated gate bipolar transistor (IGBT) is a kind of asymmetry process, while the whole life cycles of a set of IGBTs can be regarded as a symmetry process. Modelling these symmetry characteristics of the IGBT life cycles enables the improvement of the remaining useful life (RUL) prediction performance. For this purpose, based on the key failure mechanism of IGBT in electric vehicles, a new method for estimating the RUL of an IGBT module is proposed based on the two-stress acceleration synthesis environment of junction temperature and vibration. The maximum likelihood estimation (MLE) was employed to estimate the logarithmic standard deviation and covariance matrix. The Shapiro–Wilk (S–W) test was performed to investigate the satisfaction degree of the RUL of the IGBT module to the lognormal distribution. The accelerated life test datasets of the IGBT module were analyzed using the Weibull++ software. The analysis results demonstrate that the IGBT lifetime is confirmed to lognormal distribution, and the accelerated model accords with the generalized Eyring acceleration model. The proposed method can estimate IGBT RUL in a short time, which provides a certain technical reference for the reliability analysis of the IGBT module. Full article
(This article belongs to the Special Issue Symmetry in Mechanical Engineering Ⅱ)
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Open AccessArticle
Emotional Intelligence of Engineering Students as Basis for More Successful Learning Process for Industry 4.0
Mathematics 2020, 8(8), 1321; https://doi.org/10.3390/math8081321 (registering DOI) - 08 Aug 2020
Abstract
The purpose of this paper is creating analyses for understanding the personality characteristics related to emotional intelligence and how can this define the development program of personal characteristics in the processes of education for Industry 4.0. The main research goal is to measure [...] Read more.
The purpose of this paper is creating analyses for understanding the personality characteristics related to emotional intelligence and how can this define the development program of personal characteristics in the processes of education for Industry 4.0. The main research goal is to measure dimensions of emotional intelligence in the student population based on a quantitative survey (Emotional Competence Inventory) through dimensions of emotional intelligence: self-regulation, self-awareness, and attitude towards changes. Since the student population was the research target, a group of 338 engineering students was selected. The group was characterized by highly diversified geographic origin, having previously completed school and achieved success. The results show that there are statistically significant differences between all three dimensions of emotional intelligence. Namely, self-regulation and attitude towards changes (both directly and indirectly through self-regulation) are positively affected by self-awareness, while attitude towards changes is positively affected by self-regulation. Developing student emotional potential is one of the most important actuators of business for Industry 4.0, especially in countries with low educational attainment and low social and economic indicators. Full article
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Open AccessLetter
Polarizer-Free AOTF-Based SWIR Hyperspectral Imaging for Biomedical Applications
Sensors 2020, 20(16), 4439; https://doi.org/10.3390/s20164439 (registering DOI) - 08 Aug 2020
Abstract
Optical biomedical imaging in short wave infrared (SWIR) range within 0.9–1.7 μm is a rapidly developing technique. For this reason, there is an increasing interest in cost-effective and robust hardware for hyperspectral imaging data acquisition in this range. Tunable-filter-based solutions are of particular [...] Read more.
Optical biomedical imaging in short wave infrared (SWIR) range within 0.9–1.7 μm is a rapidly developing technique. For this reason, there is an increasing interest in cost-effective and robust hardware for hyperspectral imaging data acquisition in this range. Tunable-filter-based solutions are of particular interest as they provide image processing flexibility and effectiveness in terms of collected data volume. Acousto-optical tunable filters (AOTFs) provide a unique set of features necessary for high-quality SWIR hyperspectral imaging. In this paper, we discuss a polarizer-free configuration of an imaging AOTF that provides a compact and easy-to-integrate design of the whole imager. We have carried out image quality analysis of this system, assembled it and validated its efficiency through multiple experiments. The developed system can be helpful in many hyperspectral applications including biomedical analyses. Full article
(This article belongs to the Special Issue Acousto-Optic Sensing for Biomedical Imaging )
Open AccessReview
Nutritional Indices for Assessing Fatty Acids: A Mini-Review
by and
Int. J. Mol. Sci. 2020, 21(16), 5695; https://doi.org/10.3390/ijms21165695 (registering DOI) - 08 Aug 2020
Abstract
Dietary fats are generally fatty acids that may play positive or negative roles in the prevention and treatment of diseases. In nature, fatty acids occur in the form of mixtures of saturated fatty acid (SFA), monounsaturated fatty acid (MUFA), and polyunsaturated fatty acid [...] Read more.
Dietary fats are generally fatty acids that may play positive or negative roles in the prevention and treatment of diseases. In nature, fatty acids occur in the form of mixtures of saturated fatty acid (SFA), monounsaturated fatty acid (MUFA), and polyunsaturated fatty acid (PUFA), so their nutritional and/or medicinal values must be determined. Herein, we do not consider the classic indices, such as ∑SFA, ∑MUFA, ∑PUFA, ∑n-6 PUFA, ∑n-3 PUFA, and n-6 PUFA/n-3 PUFA; instead, we summarize and review the definitions, implications, and applications of indices used in recent years, including the PUFA/SFA, index of atherogenicity (IA), the index of thrombogenicity (IT), the hypocholesterolemic/hypercholesterolemic ratio (HH), the health-promoting index (HPI), the unsaturation index (UI), the sum of eicosapentaenoic acid and docosahexaenoic acid (EPA + DHA), fish lipid quality/flesh lipid quality (FLQ), the linoleic acid/α-linolenic acid (LA/ALA) ratio, and trans fatty acid (TFA). Of these nutritional indices, IA and IT are the most commonly used to assess the composition of fatty acids as they outline significant implications and provide clear evidence. EPA + DHA is commonly used to assess the nutritional quality of marine animal products. All indices have their advantages and disadvantages; hence, a rational choice of which to use is critical. Full article
(This article belongs to the Special Issue Applications and Biotechnological Synthesis of Functional Lipids)
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Open AccessArticle
Biodiesel Production from Four Residential Waste Frying Oils: Proposing Blends for Improving the Physicochemical Properties of Methyl Biodiesel
Energies 2020, 13(16), 4111; https://doi.org/10.3390/en13164111 (registering DOI) - 08 Aug 2020
Abstract
The physicochemical properties of biodiesel fuels and their blends prepared from four residential waste vegetable frying oils (sunflower (FSME), canola (FCME), mixture of sunflower and rapeseed (FSRME) and corn (FSCME)) were evaluated and measured to determine the best blend. The results indicate that [...] Read more.
The physicochemical properties of biodiesel fuels and their blends prepared from four residential waste vegetable frying oils (sunflower (FSME), canola (FCME), mixture of sunflower and rapeseed (FSRME) and corn (FSCME)) were evaluated and measured to determine the best blend. The results indicate that the stability of 10 biodiesel blends was above 10 h for 0-month, meeting the stability requirement regulated in EN 14214:2014 by adding FSCME, which depends on the concentration amount of FSCME. Besides, the results showed that all fuel samples did not meet the requirements of diesel fuel standards. Therefore, automobile gasoline is used as an additive to unmixed biodiesel in various concentrations to reduce the kinematic viscosity, density and cold flow properties. The results indicate that BG85 and BG80 have met the mixed pure biodiesel with gasoline fulfilled diesel fuel quality standard. Therefore, the samples with stability above 10 h were mixed with gasoline in 15% and 20% to reduce the cold flow properties and meet the specifications of the diesel fuel standards. Moreover, the effect of long-term storage on the properties of all samples was investigated under different storage conditions. The results indicate that higher storage temperatures and longer storage periods negatively influenced the properties of the fuel samples. Full article
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Open AccessArticle
New Stability Criteria for Discrete Linear Systems Based on Orthogonal Polynomials
Mathematics 2020, 8(8), 1322; https://doi.org/10.3390/math8081322 (registering DOI) - 08 Aug 2020
Abstract
A new criterion for Schur stability is derived by using basic results of the theory of orthogonal polynomials. In particular, we use the relation between orthogonal polynomials on the real line and on the unit circle known as the Szego transformation. Some examples [...] Read more.
A new criterion for Schur stability is derived by using basic results of the theory of orthogonal polynomials. In particular, we use the relation between orthogonal polynomials on the real line and on the unit circle known as the Szego transformation. Some examples are presented. Full article

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