Latest Articles

Open AccessArticle
Automatic Single Droplet Generator with Control over Droplet Size and Detachment Frequency
Colloids Interfaces 2019, 3(3), 57; https://doi.org/10.3390/colloids3030057 (registering DOI) -
Abstract
This paper presents a quite simple, fully automatized single droplet generator, which can be an alternative for more expensive and complicated microfluidic devices. The simple generation nozzle connected to the pressure cells and cheap peristaltic pumps, synchronized via developed software with simple GUI [...] Read more.
This paper presents a quite simple, fully automatized single droplet generator, which can be an alternative for more expensive and complicated microfluidic devices. The simple generation nozzle connected to the pressure cells and cheap peristaltic pumps, synchronized via developed software with simple GUI (graphical user interface) implemented into the Raspberry Pi microcomputer allows precise control over the single droplet diameter and detachment frequency. The generator allows the formation of droplets of quite wide range of diameters without the need of orifice diameter replacements. Free control over time available for adsorption of surface active-substances over the surface of immobilized droplet, before its detachment from the orifice, is an advantage of the developed device. Full article
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Open AccessArticle
“Florentino Ariza Sat Bedazzled”: Initiating an Exploration of Literary Texts with Dante in the Undergraduate Seminar
Religions 2019, 10(9), 496; https://doi.org/10.3390/rel10090496 (registering DOI) -
Abstract
Dante’s Commedia provides a useful context or “frame” for a discussion of love in literature from the Middle Ages to the present day in the undergraduate seminar. Selected cantos of the Commedia can initiate an examination of love—lust, romantic love, caritas—and provide [...] Read more.
Dante’s Commedia provides a useful context or “frame” for a discussion of love in literature from the Middle Ages to the present day in the undergraduate seminar. Selected cantos of the Commedia can initiate an examination of love—lust, romantic love, caritas—and provide ways to analyze depictions of love by important authors. For example, Inferno Cantos I and III introduce the concept of the “journey”—Dante’s through the three realms of the afterlife, and our “journey” through a series of texts to be read over one semester. Dante’s education in Inferno constitutes an understanding of sin and of hell as the farthest place from God and His love. Moreover, in Canto I of Paradiso, Dante reiterates that God and His love can be found throughout creation “in some places more and in others less” (I: 3), and he concludes his poem with a vision of God and of the entire universe as moved by His love. Six great authors—Francis of Assisi, Vittoria Colonna, William Shakespeare, Jane Austen, Flannery O’Connor, and Gabriel García Márquez—articulate in their own words this very human experience of love, of loving something or loving someone. In the process, they illuminate both Dante’s experience in the afterlife and ours in the modern world. Full article
Open AccessArticle
Switch Elements with S-Shaped Current-Voltage Characteristic in Models of Neural Oscillators
Electronics 2019, 8(9), 922; https://doi.org/10.3390/electronics8090922 (registering DOI) -
Abstract
In this paper, we present circuit solutions based on a switch element with the S-type I–V characteristic implemented using the classic FitzHugh–Nagumo and FitzHugh–Rinzel models. Using the proposed simplified electrical circuits allows the modeling of the integrate-and-fire neuron and burst oscillation modes with [...] Read more.
In this paper, we present circuit solutions based on a switch element with the S-type I–V characteristic implemented using the classic FitzHugh–Nagumo and FitzHugh–Rinzel models. Using the proposed simplified electrical circuits allows the modeling of the integrate-and-fire neuron and burst oscillation modes with the emulation of the mammalian cold receptor patterns. The circuits were studied using the experimental I–V characteristic of an NbO2 switch with a stable section of negative differential resistance (NDR) and a VO2 switch with an unstable NDR, considering the temperature dependences of the threshold characteristics. The results are relevant for modern neuroelectronics and have practical significance for the introduction of the neurodynamic models in circuit design and the brain–machine interface. The proposed systems of differential equations with the piecewise linear approximation of the S-type I–V characteristic may be of scientific interest for further analytical and numerical research and development of neural networks with artificial intelligence. Full article
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Open AccessReview
Anthocyanins and Their Metabolites as Therapeutic Agents for Neurodegenerative Disease
Antioxidants 2019, 8(9), 333; https://doi.org/10.3390/antiox8090333 (registering DOI) -
Abstract
Neurodegenerative diseases, including Alzheimer’s disease, Parkinson’s disease, and amyotrophic lateral sclerosis (ALS), are characterized by the death of neurons within specific regions of the brain or spinal cord. While the etiology of many neurodegenerative diseases remains elusive, several factors are thought to contribute [...] Read more.
Neurodegenerative diseases, including Alzheimer’s disease, Parkinson’s disease, and amyotrophic lateral sclerosis (ALS), are characterized by the death of neurons within specific regions of the brain or spinal cord. While the etiology of many neurodegenerative diseases remains elusive, several factors are thought to contribute to the neurodegenerative process, such as oxidative and nitrosative stress, excitotoxicity, endoplasmic reticulum stress, protein aggregation, and neuroinflammation. These processes culminate in the death of vulnerable neuronal populations, which manifests symptomatically as cognitive and/or motor impairments. Until recently, most treatments for these disorders have targeted single aspects of disease pathology; however, this strategy has proved largely ineffective, and focus has now turned towards therapeutics which target multiple aspects underlying neurodegeneration. Anthocyanins are unique flavonoid compounds that have been shown to modulate several of the factors contributing to neuronal death, and interest in their use as therapeutics for neurodegeneration has grown in recent years. Additionally, due to observations that the bioavailability of anthocyanins is low relative to that of their metabolites, it has been proposed that anthocyanin metabolites may play a significant part in mediating the beneficial effects of an anthocyanin-rich diet. Thus, in this review, we will explore the evidence evaluating the neuroprotective and therapeutic potential of anthocyanins and their common metabolites for treating neurodegenerative diseases. Full article
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Open AccessBrief Report
Endogenous Neuropeptide Nocistatin Is a Direct Agonist of Acid-Sensing Ion Channels (ASIC1, ASIC2 and ASIC3)
Biomolecules 2019, 9(9), 401; https://doi.org/10.3390/biom9090401 (registering DOI) -
Abstract
Acid-sensing ion channel (ASIC) channels belong to the family of ligand-gated ion channels known as acid-sensing (proton-gated) ion channels. Only a few activators of ASICs are known. These are exogenous and endogenous molecules that cause a persistent, slowly desensitized current, different from an [...] Read more.
Acid-sensing ion channel (ASIC) channels belong to the family of ligand-gated ion channels known as acid-sensing (proton-gated) ion channels. Only a few activators of ASICs are known. These are exogenous and endogenous molecules that cause a persistent, slowly desensitized current, different from an acid-induced current. Here we describe a novel endogenous agonist of ASICs—peptide nocistatin produced by neuronal cells and neutrophils as a part of prepronociceptin precursor protein. The rat nocistatin evoked currents in X. laevis oocytes expressing rat ASIC1a, ASIC1b, ASIC2a, and ASIC3 that were very similar in kinetic parameters to the proton-gated response. Detailed characterization of nocistatin action on rASIC1a revealed a proton-like dose-dependence of activation, which was accompanied by a dose-dependent decrease in the sensitivity of the channel to the protons. The toxin mambalgin-2, antagonist of ASIC1a, inhibited nocistatin-induced current, therefore the close similarity of mechanisms for ASIC1a activation by peptide and protons could be suggested. Thus, nocistatin is the first endogenous direct agonist of ASICs. This data could give a key to understanding ASICs activation regulation in the nervous system and also could be used to develop new drugs to treat pathological processes associated with ASICs activation, such as neurodegeneration, inflammation, and pain. Full article
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Open AccessArticle
Extreme Learning Machines to Combat Phase Noise in RoF-OFDM Schemes
Electronics 2019, 8(9), 921; https://doi.org/10.3390/electronics8090921 (registering DOI) -
Abstract
Radio-over-fiber (RoF) orthogonal frequency division multiplexing (OFDM) systems have been revealed as the solution to support secure, cost-effective, and high-capacity wireless access for the future telecommunication systems. Unfortunately, the bandwidth-distance product in these schemes is mainly limited by phase noise that comes from [...] Read more.
Radio-over-fiber (RoF) orthogonal frequency division multiplexing (OFDM) systems have been revealed as the solution to support secure, cost-effective, and high-capacity wireless access for the future telecommunication systems. Unfortunately, the bandwidth-distance product in these schemes is mainly limited by phase noise that comes from the laser linewidth, as well as the chromatic fiber dispersion. On the other hand, the single-hidden layer feedforward neural network subject to the extreme learning machine (ELM) algorithm has been widely studied in regression and classification problems for different research fields, because of its good generalization performance and extremely fast learning speed. In this work, ELMs in the real and complex domains for direct-detection OFDM-based RoF schemes are proposed for the first time. These artificial neural networks are based on the use of pilot subcarriers as training samples and data subcarriers as testing samples, and consequently, their learning stages occur in real-time without decreasing the effective transmission rate. Regarding the feasible pilot-assisted equalization method, the effectiveness and simplicity of the ELM algorithm in the complex domain are highlighted by evaluation of a QPSK-OFDM signal over an additive white Gaussian noise channel at diverse laser linewidths and chromatic fiber dispersion effects and taking into account several OFDM symbol periods. Considering diverse relationships between the fiber transmission distance and the radio frequency (for practical design purposes) and the duration of a single OFDM symbol equal to 64 ns, the fully-complex ELM followed by the real ELM outperform the pilot-based correction channel in terms of the system performance tolerance against the signal-to-noise ratio and the laser linewidth. Full article
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Open AccessArticle
gEYEded: Subtle and Challenging Gaze-Based Player Guidance in Exploration Games
Multimodal Technologies Interact. 2019, 3(3), 61; https://doi.org/10.3390/mti3030061 (registering DOI) -
Abstract
This paper investigates the effects of gaze-based player guidance on the perceived game experience, performance, and challenge in a first-person exploration game. In contrast to existing research, the proposed approach takes the game context into account by providing players not only with guidance [...] Read more.
This paper investigates the effects of gaze-based player guidance on the perceived game experience, performance, and challenge in a first-person exploration game. In contrast to existing research, the proposed approach takes the game context into account by providing players not only with guidance but also granting them an engaging game experience with a focus on exploration. This is achieved by incorporating gaze-sensitive areas that indicate the location of relevant game objects. A comparative study was carried out to validate our concept and to examine if a game supported with a gaze guidance feature triggers a more immersive game experience in comparison to a crosshair guidance version and a solution without any guidance support. In general, our study findings reveal a more positive impact of the gaze-based guidance approach on the experience and performance in comparison to the other two conditions. However, subjects had a similar impression concerning the game challenge in all conditions. Full article
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Open AccessArticle
A Mouse Model to Assess STAT3 and STAT5A/B Combined Inhibition in Health and Disease Conditions
Cancers 2019, 11(9), 1226; https://doi.org/10.3390/cancers11091226 (registering DOI) -
Abstract
Genetically-engineered mouse models (GEMMs) lacking diseased-associated gene(s) globally or in a tissue-specific manner represent an attractive tool with which to assess the efficacy and toxicity of targeted pharmacological inhibitors. Stat3 and Stat5a/b transcription factors have been implicated in several pathophysiological conditions, and pharmacological [...] Read more.
Genetically-engineered mouse models (GEMMs) lacking diseased-associated gene(s) globally or in a tissue-specific manner represent an attractive tool with which to assess the efficacy and toxicity of targeted pharmacological inhibitors. Stat3 and Stat5a/b transcription factors have been implicated in several pathophysiological conditions, and pharmacological inhibition of both transcription factors has been proposed to treat certain diseases, such as malignancies. To model combined inhibition of Stat3 and Stat5a/b we have developed a GEMM harboring a flox Stat3-Stat5a/b allele (Stat5/3loxP/loxP mice) and generated mice lacking Stat3 and Stat5a/b in hepatocytes (Stat5/3Δhep/Δhep). Stat5/3Δhep/Δhep mice exhibited a marked reduction of STAT3, STAT5A and STAT5B proteins in the liver and developed steatosis, a phenotype that resembles mice lacking Stat5a/b in hepatocytes. In addition, embryonic deletion of Stat3 and Stat5a/b (Stat5/3Δ/Δ mice) resulted in lethality, similar to Stat3Δ/Δ mice. This data illustrates that Stat5/3loxP/loxP mice are functional and can be used as a valuable tool to model the combined inhibition of Stat3 and Stat5a/b in tumorigenesis and other diseases. Full article
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Open AccessArticle
A Tree Species Mapping Method from UAV Images over Urban Area Using Similarity in Tree-Crown Object Histograms
Remote Sens. 2019, 11(17), 1982; https://doi.org/10.3390/rs11171982 (registering DOI) -
Abstract
Timely and accurate information about spatial distribution of tree species in urban areas provides crucial data for sustainable urban development, management and planning. Very high spatial resolution data collected by sensors onboard Unmanned Aerial Vehicles (UAV) systems provide rich data sources for mapping [...] Read more.
Timely and accurate information about spatial distribution of tree species in urban areas provides crucial data for sustainable urban development, management and planning. Very high spatial resolution data collected by sensors onboard Unmanned Aerial Vehicles (UAV) systems provide rich data sources for mapping tree species. This paper proposes a method of tree species mapping from UAV images over urban areas using similarity in tree-crown object histograms and a simple thresholding method. Tree-crown objects are first extracted and used as processing units in subsequent steps. Tree-crown object histograms of multiple features, i.e., spectral and height related features, are generated to quantify within-object variability. A specific tree species is extracted by comparing similarity in histogram between a target tree-crown object and reference objects. The proposed method is evaluated in mapping four different tree species using UAV multispectral ortho-images and derived Digital Surface Model (DSM) data collected in Shanghai urban area, by comparing with an existing method. The results demonstrate that the proposed method outperforms the comparative method for all four tree species, with improvements of 0.61–5.81% in overall accuracy. The proposed method provides a simple and effective way of mapping tree species over urban area. Full article
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Open AccessArticle
Effects of Temperature, Growth Media, and Photoperiod on Growth and Toxin Production of Azadinium spinosum
Mar. Drugs 2019, 17(9), 489; https://doi.org/10.3390/md17090489 (registering DOI) -
Abstract
Azaspiracids (AZAs) are microalgal toxins that can accumulate in shellfish and lead to human intoxications. To facilitate their study and subsequent biomonitoring, purification from microalgae rather than shellfish is preferable; however, challenges remain with respect to maximizing toxin yields. The impacts of temperature, [...] Read more.
Azaspiracids (AZAs) are microalgal toxins that can accumulate in shellfish and lead to human intoxications. To facilitate their study and subsequent biomonitoring, purification from microalgae rather than shellfish is preferable; however, challenges remain with respect to maximizing toxin yields. The impacts of temperature, growth media, and photoperiod on cell densities and toxin production in Azadinium spinosum were investigated. Final cell densities were similar at 10 and 18 °C, while toxin cell quotas were higher (~3.5-fold) at 10 °C. A comparison of culture media showed higher cell densities and AZA cell quotas (2.5–5-fold) in f10k compared to f/2 and L1 media. Photoperiod also showed differences, with lower cell densities in the 8:16 L:D treatment, while toxin cell quotas were similar for 12:12 and 8:16 L:D treatments but slightly lower for the 16:8 L:D treatment. AZA1, -2 and -33 were detected during the exponential phase, while some known and new AZAs were only detected once the stationary phase was reached. These compounds were additionally detected in field water samples during an AZA event. Full article
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Open AccessDiscussion
Research and Development in Carbon Fibers and Advanced High-Performance Composites Supply Chain in Europe: A Roadmap for Challenges and the Industrial Uptake
J. Compos. Sci. 2019, 3(3), 86; https://doi.org/10.3390/jcs3030086 (registering DOI) -
Abstract
Structural materials, typically based on metal, have been gradually substituted by high-performance composites based on carbon fibers, embedded in a polymer matrix, due to their potential to provide lighter, stronger, and more durable solutions. In the last decades, the composites industry has witnessed [...] Read more.
Structural materials, typically based on metal, have been gradually substituted by high-performance composites based on carbon fibers, embedded in a polymer matrix, due to their potential to provide lighter, stronger, and more durable solutions. In the last decades, the composites industry has witnessed a sustained growth, especially due to diffusion of these materials in key markets, such as the construction, wind energy, aeronautics, and automobile sectors. Carbon fibers are, by far, the most widely used fiber in high-performance applications. This important technology has huge potential for the future and it is expected to have a significant impact in the manufacturing industry within Europe and, therefore, coordination and strategic roadmapping actions are required. To lead a further drive to develop the potential of composites into new sectors, it is important to establish strategic roadmapping actions, including the development of business and cost models, supply chains implementation, and development, suitability for high volume markets and addressing technology management. Europe already has a vibrant and competitive composites industry that is supported by several research centers, but for its positioning in a forefront position in this technology, further challenges are still required to be addressed. Full article
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Open AccessReview
Human Skin Lightening Efficacy of Resveratrol and Its Analogs: From in Vitro Studies to Cosmetic Applications
Antioxidants 2019, 8(9), 332; https://doi.org/10.3390/antiox8090332 (registering DOI) -
Abstract
Antioxidants are deemed useful in controlling oxidative stress associated with extrinsic skin aging and pigmentation disorders. Resveratrol is a polyphenol compound found in many edible plants such as Vitis vinifera, and its inhibitory effects on the catalytic activity, gene expression, and posttranslational [...] Read more.
Antioxidants are deemed useful in controlling oxidative stress associated with extrinsic skin aging and pigmentation disorders. Resveratrol is a polyphenol compound found in many edible plants such as Vitis vinifera, and its inhibitory effects on the catalytic activity, gene expression, and posttranslational modifications of tyrosinase, a key enzyme in the melanin biosynthetic pathway, provide a mechanistic basis for its antimelanogenic effects seen in melanocytic cells, three-dimensionally reconstituted skin models, and in vivo animal models. As a potent antioxidant and a modulator of nuclear factor erythroid 2-related factor 2 (Nrf2), and sirtuin 1, resveratrol can also regulate multiple signaling pathways associated with inflammation and premature aging. Recent clinical studies have supported the efficacy of resveratrol and its analogs, such as resveratryl triacetate (RTA) and resveratryl triglycolate (RTG), in human skin lightening and antiaging. These findings suggest that resveratrol and its analogs are potentially useful as skin lightening and antiaging agents in cosmetics. Full article
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Open AccessFeature PaperArticle
Biodegradation Potential and Diversity of Diclofenac-degrading Microbiota in an Immobilized Cell Biofilter
Processes 2019, 7(9), 554; https://doi.org/10.3390/pr7090554 (registering DOI) -
Abstract
Despite that diclofenac has been embodied to the European watch list of priority substances of concern, studies on diclofenac biodegradation are limited and the diversity of diclofenac-degrading microbiota remains unknown. In this work, an immobilized cell biofilter was constructed and operated to evaluate [...] Read more.
Despite that diclofenac has been embodied to the European watch list of priority substances of concern, studies on diclofenac biodegradation are limited and the diversity of diclofenac-degrading microbiota remains unknown. In this work, an immobilized cell biofilter was constructed and operated to evaluate its effectiveness to depurate high strength diclofenac wastewater and to identify the diclofenac-degrading community accommodated in activated sludge by employing high-throughput sequencing techniques. After a two-month adaptation period, biofilter removal efficiencies reached values as high as 97.63 ± 0.62%, whereas utilization of diclofenac in the immobilized cell biofilter led to a drastic pH decrease. Based on Illumina sequencing, the major bacterial taxa identified in the immobilized cell biofilter were members of the species Granulicella pectinivorans and Rhodanobacter terrae, followed by members of the species Castellaniella denitrificans, Parvibaculum lavamentivorans, Bordetella petrii, Bryocella elongata and Rhodopseudomonas palustris. The ability of such taxa to utilize a wide range of carbon sources and to effectively adapt under acidic conditions seemed to be the main parameters, which favored their prevalence in the immobilized cell biofilter. In addition, Wickerhamiella was the predominant fungal taxon in the immobilized cell biofilter, which appears to be actively involved in diclofenac degradation in activated sludge systems. Full article
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