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Open AccessArticle
The Costs of Green Leaf Volatile-Induced Defense Priming: Temporal Diversity in Growth Responses to Mechanical Wounding and Insect Herbivory
Plants 2019, 8(1), 23; https://doi.org/10.3390/plants8010023 (registering DOI) -
Abstract
Green leaf volatiles (GLVs) have long been associated with plant defense responses against insect herbivory. Although some of their biological activities appear to directly affect the attacking herbivore, one of the major functions of GLVs seems to be the priming of these defense
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Green leaf volatiles (GLVs) have long been associated with plant defense responses against insect herbivory. Although some of their biological activities appear to directly affect the attacking herbivore, one of the major functions of GLVs seems to be the priming of these defense responses. This priming is generally considered to impose low costs on the plant should no direct attack happen. Here, we demonstrate that priming of maize seedlings with GLVs is costly for the plants as it results in significantly reduced growth. We further demonstrate that priming very selectively affects growth responses after insect elicitor treatment and mechanical wounding depending on the age and/or the developmental stage of the treated plant. The differential growth response of maize seedlings to treatment with GLVs and subsequent herbivory-related damage sheds new light on the biological activity of these important plant volatile compounds and indicates consequences that go beyond defense. Full article
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Open AccessArticle
Blockchains for Supply Chain Management: Architectural Elements and Challenges Towards a Global Scale Deployment
Logistics 2019, 3(1), 5; https://doi.org/10.3390/logistics3010005 (registering DOI) -
Abstract
Blockchains are attracting the attention of stakeholders in many industrial domains, including the logistics and supply chain industries. Blockchain technology can effectively contribute in recording every single asset throughout its flow on the supply chain, contribute in tracking orders, receipts, and payments, while
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Blockchains are attracting the attention of stakeholders in many industrial domains, including the logistics and supply chain industries. Blockchain technology can effectively contribute in recording every single asset throughout its flow on the supply chain, contribute in tracking orders, receipts, and payments, while track digital assets such as warranties and licenses in a unified and transparent way. The paper provides, through its methodology, a detailed analysis of the blockchain fit in the supply chain industry. It defines the specific elements of blockchain that affect supply chain such as scalability, performance, consensus mechanism, privacy considerations, location proof and cost, and details on the impact that blockchains will have in disrupting the supply chain industry. Discussing the tradeoff between consensus cost, throughput and validation time it proceeds with a suggested high-level architectural approach, and concludes as a result with a discussion on changes needed and challenges faced for an in-vivo deployment of blockchains in the supply chain industry. While the technological features of modern blockchains can effectively facilitate supply chain uses cases, the various challenges that still remain, bring in front of us a wide set of needed changes and further research efforts for achieving a global, production level blockchain for the supply chain industry. Full article
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Open AccessEditorial
Biofuel and Bioenergy Technology
Energies 2019, 12(2), 290; https://doi.org/10.3390/en12020290 (registering DOI) -
Abstract
Biomass is considered as a renewable resource because of its short life cycle, and biomass-derived biofuels are potential substitutes to fossil fuels [...] Full article
Open AccessArticle
Intestinal Drug Absorption Enhancement by Aloe vera Gel and Whole Leaf Extract: In Vitro Investigations into the Mechanisms of Action
Pharmaceutics 2019, 11(1), 36; https://doi.org/10.3390/pharmaceutics11010036 (registering DOI) -
Abstract
The co-administration of absorption enhancing agents with macromolecular drugs (e.g., protein and peptide drugs) has been identified as a means to improve the oral bioavailability of these drugs. Absorption-enhancing agents of natural origins have received a great deal of attention due to their
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The co-administration of absorption enhancing agents with macromolecular drugs (e.g., protein and peptide drugs) has been identified as a means to improve the oral bioavailability of these drugs. Absorption-enhancing agents of natural origins have received a great deal of attention due to their sustainable production, in support of green chemistry. In previous studies, certain parts of the Aloe vera leaf (e.g., gel and whole leaf extract) have shown a potential to enhance drug permeation across the intestinal epithelial barrier. The mechanism of the drug-absorption-enhancement action and the capacity for absorption-enhancement of the A. vera gel and whole leaf, were investigated in this study. A clear decrease in transepithelial electrical resistance (TEER) of Caco-2 cell monolayers exposed to A. vera gel and wholeleaf extract, in various concentrations, indicated the opening of tight junctions between the epithelial cells. The transport of Fluorescein isothiocyanate (FITC)-dextran, with a molecular weight of 4 kDa (FD-4), could be enhanced across the Caco-2 cell monolayers, by the A. vera gel and whole-leaf extract, but not the FITC-dextran with larger molecular weights (i.e., 10, 20, and 40 kDa), which indicated a limited drug absorption enhancement capacity, in terms of the molecular size. Accumulation of FD-4 between the Caco-2 cells (and not within the cells), after treatment with the A. vera gel and whole-leaf extract was shown with a confocal laser scanning microscopy (CLSM) imaging, indicating that the paracellular transport of FD-4 occurred after the interaction of the A. vera gel and whole-leaf extract, with the epithelial cell monolayers. Furthermore, changes in the F-actin distribution in the cytoskeleton of the Caco-2 cell monolayers was observed by means of a fluorescence staining, which confirmed tight junction modulation as the mechanism of action for the absorption enhancement effect of the A. vera gel and whole-leaf extract. Full article
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Open AccessReview
Modulation of the Endocannabinoid System Following Central Nervous System Injury
Int. J. Mol. Sci. 2019, 20(2), 388; https://doi.org/10.3390/ijms20020388 (registering DOI) -
Abstract
Central nervous system (CNS) injury, such as stroke or trauma, is known to increase susceptibility to various infections that adversely affect patient outcomes (CNS injury-induced immunodepression—CIDS). The endocannabinoid system (ECS) has been shown to have immunoregulatory properties. Therefore, the ECS might represent a
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Central nervous system (CNS) injury, such as stroke or trauma, is known to increase susceptibility to various infections that adversely affect patient outcomes (CNS injury-induced immunodepression—CIDS). The endocannabinoid system (ECS) has been shown to have immunoregulatory properties. Therefore, the ECS might represent a druggable target to overcome CIDS. Evidence suggests that cannabinoid type 2 receptor (CB2R) activation can be protective during the early pro-inflammatory phase after CNS injury, as it limits neuro-inflammation and, therefore, attenuates CIDS severity. In the later phase post CNS injury, CB2R inhibition is suggested as a promising pharmacologic strategy to restore immune function in order to prevent infection. Full article
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Open AccessBenchmark
A Computer-Vision-Guided Robot Arm for Automatically Placing Grids in Pioloform Film Preparation
Methods Protoc. 2019, 2(1), 9; https://doi.org/10.3390/mps2010009 (registering DOI) -
Abstract
Preparing pioloform/formvar support films on transmission electron microscopy (TEM) grids is a routine laboratory procedure in practically all electron microscopy units. In current practice, these grids are manually placed on the support film one by one using special tweezers, a process requiring a
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Preparing pioloform/formvar support films on transmission electron microscopy (TEM) grids is a routine laboratory procedure in practically all electron microscopy units. In current practice, these grids are manually placed on the support film one by one using special tweezers, a process requiring a steady hand. The work is often ergonomically awkward to continue for a longer period of time. In this article, we describe a low-cost, computer vision-guided robot arm that automatically places the grids on the film. The success rate of the prototype robot is 90%, which is comparable to an experienced laboratory technician. Full article
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Open AccessArticle
Hydrogen Bond versus Halogen Bond in HXOn (X = F, Cl, Br, and I) Complexes with Lewis Bases
Inorganics 2019, 7(1), 9; https://doi.org/10.3390/inorganics7010009 (registering DOI) -
Abstract
We have theoretically studied the formation of hydrogen-bonded (HB) and halogen-bonded (XB) complexes of halogen oxoacids (HXOn) with Lewis bases (NH3 and Cl) at the CCSD(T)/CBS//RIMP2/aug-cc-pVTZ level of theory. Minima structures have been found for all HB and
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We have theoretically studied the formation of hydrogen-bonded (HB) and halogen-bonded (XB) complexes of halogen oxoacids (HXOn) with Lewis bases (NH3 and Cl) at the CCSD(T)/CBS//RIMP2/aug-cc-pVTZ level of theory. Minima structures have been found for all HB and XB systems. Proton transfer is generally observed in complexes with three or four oxygen atoms, namely, HXO4:NH3, HClO3:Cl, HBrO3:Cl, and HXO4:Cl. All XB complexes fall into the category of halogen-shared complexes, except for HClO4:NH3 and HClO4:Cl, which are traditional ones. The interaction energies generally increase with the number of O atoms. Comparison of the energetics of the complexes indicates that the only XB complexes that are more favored than those of HB are HIO:NH3, HIO:Cl, HIO2:Cl, and HIO3:Cl. The atoms-in-molecules (AIM) theory is used to analyze the complexes and results in good correlations between electron density and its Laplacian values with intermolecular equilibrium distances. The natural bon orbital (NBO) is used to analyze the complexes in terms of charge-transfer energy contributions, which usually increase as the number of O atoms increases. The nature of the interactions has been analyzed using the symmetry-adapted perturbation theory (SAPT) method. The results indicate that the most important energy contribution comes from electrostatics, followed by induction. Full article
Open AccessFeature PaperArticle
A Simple Indoor Localization Methodology for Fast Building Classification Models Based on Fingerprints
Electronics 2019, 8(1), 103; https://doi.org/10.3390/electronics8010103 (registering DOI) -
Abstract
Indoor localization has received tremendous attention in the last two decades due to location-aware services being highly demanded. Wireless networks have been suggested to solve this problem in many research works, and efficient algorithms have been developed with precise location and high accuracy.
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Indoor localization has received tremendous attention in the last two decades due to location-aware services being highly demanded. Wireless networks have been suggested to solve this problem in many research works, and efficient algorithms have been developed with precise location and high accuracy. Nevertheless, those approaches often have high computational and high energy consumption. Hence, in temporary environments, such as emergency situations, where a fast deployment of an indoor localization system is required, those methods are not appropriate. In this manuscript, a methodology for fast building of an indoor localization system is proposed. For that purpose, a reduction of the data dimensionality is achieved by applying data fusion and feature transformation, which allow us to reduce the computational cost of the classifier training phase. In order to validate the methodology, three different datasets were used: two of them are public datasets based mainly on Received Signal Strength (RSS) from different Wi-Fi access point, and the third is a set of RSS values gathered from the LED lamps in a Visible Light Communication (VLC) network. The simulation results show that the proposed methodology considerably amends the overall computational performance and provides an acceptable location estimation error. Full article
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Open AccessArticle
Rapid Prototyping of a Hybrid PV–Wind Generation System Implemented in a Real-Time Digital Simulation Platform and Arduino
Electronics 2019, 8(1), 102; https://doi.org/10.3390/electronics8010102 (registering DOI) -
Abstract
The growing penetration of generation systems based on renewable energy in electric power systems is undeniable. These generation systems have many benefits, but also many challenges from the technical point of view. One of the biggest problems in the case of solar photovoltaic
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The growing penetration of generation systems based on renewable energy in electric power systems is undeniable. These generation systems have many benefits, but also many challenges from the technical point of view. One of the biggest problems in the case of solar photovoltaic (PV) and wind energy is the intermittency of the raw material, thus hybrid generation systems that contain both sources are being used to complement electric power generation. To analyze the problems of this type of hybrid generation systems, it is necessary to develop models and test systems that allows to study their dynamic behavior. Reported in this paper is the implementation of a full hybrid PV–wind generation system model in a real-time digital simulation platform, and the development of the electronic converter controls. These controllers were implemented in digital devices (Arduino Due) and connected to the simulation platform to test their performance in real-time. In addition, the procedure followed for the development and implementation of the controllers is presented. The proposed test system can be used in renewable energy integration studies and the development of new control strategies. Full article
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Open AccessArticle
Pulsed Laser Deposited Biocompatible Lithium-Doped Hydroxyapatite Coatings with Antimicrobial Activity
Coatings 2019, 9(1), 54; https://doi.org/10.3390/coatings9010054 (registering DOI) -
Abstract
Simple and lithium-doped biological-origin hydroxyapatite layers were synthesized by Pulsed Laser Deposition technique on medical grade Ti substrates. Cytotoxic effects of lithium addition and the biocompatibility of obtained coatings were assessed using three cell lines of human origin (new initiated dermal fibroblasts, immortalized
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Simple and lithium-doped biological-origin hydroxyapatite layers were synthesized by Pulsed Laser Deposition technique on medical grade Ti substrates. Cytotoxic effects of lithium addition and the biocompatibility of obtained coatings were assessed using three cell lines of human origin (new initiated dermal fibroblasts, immortalized keratinocytes HaCaT, and MG-63 osteosarcoma). Antimicrobial properties of obtained coatings were assessed on two strains (i.e., Staphylococcus aureus and Candida albicans), belonging to species representative for the etiology of medical devices biofilm-associated infections. Our findings suggest that synthesized lithium-doped coatings exhibited low cytotoxicity on human osteosarcoma and skin cells and therefore, an excellent biocompatibility, correlated with a long-lasting anti-staphylococcal and -fungal biofilm activity. Along with low fabrication costs generated by sustainable resources, these biological-derived materials demonstrate their promising potential for future prospective solutions—viable alternatives to commercially available biomimetic HA implants—for the fabrication of a new generation of implant coatings. Full article
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Open AccessArticle
Corrosion Behavior Evaluation of Coated Steel Using Fiber Bragg Grating Sensors
Coatings 2019, 9(1), 55; https://doi.org/10.3390/coatings9010055 (registering DOI) -
Abstract
Coatings, either soft or hard, are commonly used to protect steel against corrosion for longer service life. With coatings, assessing the corrosion behavior and status of the substrate is challenging without destructive analysis. In this paper, fiber Bragg (FBG) grating sensors were proposed
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Coatings, either soft or hard, are commonly used to protect steel against corrosion for longer service life. With coatings, assessing the corrosion behavior and status of the substrate is challenging without destructive analysis. In this paper, fiber Bragg (FBG) grating sensors were proposed to nondestructively evaluate the corrosion behavior of steel coated with two popular coatings, including the polymeric and wire arc sprayed Al-Zn coating. Laboratory accelerated corrosion tests demonstrated that the embedded FBG sensors inside both the soft and hard coatings can effectively quantify the corrosion rate, monitor the corrosion progress, and detect the coating damages and crack propagation of coated steel in real time. The laboratory electrochemical corrosion test on the wire arc sprayed Al-Zn coating validated the proposed embedded FBG sensor method with a good agreement in comparison. The proposed sensing platform provides an alternative nondestructive real-time corrosion assessment approach for coated steel in the field. Full article
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