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Open AccessArticle
Puu System of Fractional Order and Its Chaos Suppression
Symmetry 2020, 12(3), 340; https://doi.org/10.3390/sym12030340 (registering DOI) - 27 Feb 2020
Abstract
In this paper, the fractional-order variant of Puu’s system is introduced, and, comparatively with its integer-order counterpart, some of its characteristics are presented. Next, an impulsive chaos control algorithm is applied to suppress the chaos. Because fractional-order continuous-time or discrete-time systems have not [...] Read more.
In this paper, the fractional-order variant of Puu’s system is introduced, and, comparatively with its integer-order counterpart, some of its characteristics are presented. Next, an impulsive chaos control algorithm is applied to suppress the chaos. Because fractional-order continuous-time or discrete-time systems have not had non-constant periodic solutions, chaos suppression is considered under some numerical assumptions. Full article
(This article belongs to the Special Issue Bifurcation and Chaos in Fractional-Order Systems)
Open AccessArticle
Livschitz Theorem in Suspension Flows and Markov Systems: Approach in Cohomology of Systems
Symmetry 2020, 12(3), 338; https://doi.org/10.3390/sym12030338 (registering DOI) - 27 Feb 2020
Abstract
It is presented and proved a version of Livschitz Theorem for hyperbolic flows pragmatically oriented to the cohomological context. Previously, it is introduced the concept of cocycle and a natural notion of symmetry for cocycles. It is discussed the fundamental relationship between the [...] Read more.
It is presented and proved a version of Livschitz Theorem for hyperbolic flows pragmatically oriented to the cohomological context. Previously, it is introduced the concept of cocycle and a natural notion of symmetry for cocycles. It is discussed the fundamental relationship between the existence of solutions of cohomological equations and the behavior of the cocycles along periodic orbits. The generalization of this theorem to a class of suspension flows is also discussed and proved. This generalization allows giving a different proof of the Livschitz Theorem for flows based on the construction of Markov systems for hyperbolic flows. Full article
Open AccessReview
Carbohydrate and Amino Acid Metabolism as Hallmarks for Innate Immune Cell Activation and Function
Cells 2020, 9(3), 562; https://doi.org/10.3390/cells9030562 (registering DOI) - 27 Feb 2020
Abstract
Immune activation is now understood to be fundamentally linked to intrinsic and/or extrinsic metabolic processes which are essential for immune cells to survive, proliferate, and perform their effector functions. Moreover, disruption or dysregulation of these pathways can result in detrimental outcomes and underly [...] Read more.
Immune activation is now understood to be fundamentally linked to intrinsic and/or extrinsic metabolic processes which are essential for immune cells to survive, proliferate, and perform their effector functions. Moreover, disruption or dysregulation of these pathways can result in detrimental outcomes and underly a number of pathologies in both communicable and non-communicable diseases. In this review, we discuss how the metabolism of carbohydrates and amino acids in particular can modulate innate immunity and how perturbations in these pathways can result in failure of these immune cells to properly function or induce unfavorable phenotypes. Full article
(This article belongs to the Special Issue Metabolic Reprogramming in Innate Immune Cell Fate and Function)
Open AccessArticle
Fe1−xS Modified TiO2 NPs Embedded Carbon Nanofiber Composite via Electrospinning: A Potential Electrode Material for Supercapacitors
Molecules 2020, 25(5), 1075; https://doi.org/10.3390/molecules25051075 (registering DOI) - 27 Feb 2020
Abstract
Fe1−xS-TiO2 nanoparticles embedded carbon nanofibers (Fe1−xS-TiO2/CNFs) composite as a supercapacitor electrode material has been reported in the present work. The Fe1−xS-TiO2/CNFs composite was fabricated by electrospinning technique followed by carbonization under argon [...] Read more.
Fe1−xS-TiO2 nanoparticles embedded carbon nanofibers (Fe1−xS-TiO2/CNFs) composite as a supercapacitor electrode material has been reported in the present work. The Fe1−xS-TiO2/CNFs composite was fabricated by electrospinning technique followed by carbonization under argon atmosphere and characterized by the state-of-art techniques. The electrochemical studies were carried out in a 2 M KOH electrolyte solution. The synthesized material showed a specific capacitance value of 138 F/g at the current density of 1 A/g. Further, the capacitance retention was about 83%. The obtained results indicate that the Fe1−xS-TiO2/CNFs composite can be recognized as electrode material in supercapacitor. Full article
(This article belongs to the Special Issue Porous Carbon Materials and Their Applications)
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Open AccessFeature PaperReview
Thermionic Vacuum Arc—A Versatile Technology for Thin Film Deposition and Its Applications
Coatings 2020, 10(3), 211; https://doi.org/10.3390/coatings10030211 (registering DOI) - 27 Feb 2020
Abstract
This review summarizes the more-than-25-years of development of the so-called thermionic vacuum arc (TVA). TVA is an anodic arc discharge in vapors of the material to be deposited; the energy for its melting is delivered by means of a focused electron beam. The [...] Read more.
This review summarizes the more-than-25-years of development of the so-called thermionic vacuum arc (TVA). TVA is an anodic arc discharge in vapors of the material to be deposited; the energy for its melting is delivered by means of a focused electron beam. The resulting material ions fall at the substrate where they form a well-adhesive layer; the ion energy is controllable. The deposited layers are, as a rule, free from droplets typical for cathodic arc deposition systems and the thermal stress of the substrates being coated is low. TVA is especially suitable for processing refractory metals, e.g., carbon or tungsten, however, in the course of time, various useful applications of this system originated. They include layers for fusion application, hard coatings, low-friction coatings, biomedical-applicable films, materials for optoelectronics, and for solid-state batteries. Apart from the diagnostic of the film properties, also the diagnostic of the TVA discharge itself as well as of the by TVA generated plasma was performed. The research and application of the TVA proceeds in broad international collaboration. At present, the TVA technology has found its firm place among the different procedures for thin film deposition. Full article
(This article belongs to the Special Issue Thin Film Coatings for Multifunctional Applications)
Open AccessArticle
Volatile Organic Compounds Profile in White Sturgeon (Acipenser transmontanus) Caviar at Different Stages of Ripening by Multiple Headspace Solid Phase Microextraction
Molecules 2020, 25(5), 1074; https://doi.org/10.3390/molecules25051074 (registering DOI) - 27 Feb 2020
Abstract
Caviar is considered a delicacy by luxury product consumers, but few data are available about its flavour chemistry to date. In this study, a multiple headspace-solid phase microextraction (MHS-SPME) followed by gas chromatography and mass spectrometry (GC-MS) approach was developed and employed to [...] Read more.
Caviar is considered a delicacy by luxury product consumers, but few data are available about its flavour chemistry to date. In this study, a multiple headspace-solid phase microextraction (MHS-SPME) followed by gas chromatography and mass spectrometry (GC-MS) approach was developed and employed to identify and quantitatively estimate key volatile organic compounds (VOCs) representative in white sturgeon (A. transmontanus) caviar at five different stages of ripening: raw eggs (t0), after 60 days (t1), 120 days (t2), 180 days (t3), and 240 days (t4) of ripening. The method showed the ability to detect and estimate the quantity of 25 flavour compounds, without any severe alteration of the matrix before the analysis and in a short time. The VOCs detected as representative in caviar samples were primarily aldehydes and alcohols, already well known as responsible of fresh fish and seafood flavours, and mainly deriving from lipid peroxidation processes and microbial activity against lipids and amino acids. We found a significant (p < 0.01) increase in the amount of total aldehydes within t0 (29.64 ng/g) and t4 (121.96 ng/g); moreover, an interesting, great arise of 3-hydroxy-2-butanone at the final stage of storage (48.17 ng/g) was recorded. Alcohols were not detected in raw eggs (t0) and then a decrease from t1 (17.77 ng/g) to t4 (10.18 ng/g) was recorded in their amount, with no statistical significance. Full article
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Open AccessArticle
Activation of JNK and p38 in MCF-7 Cells and the In Vitro Anticancer Activity of Alnus hirsuta Extract
Molecules 2020, 25(5), 1073; https://doi.org/10.3390/molecules25051073 (registering DOI) - 27 Feb 2020
Abstract
JNK and p38 are important mitogen-activated protein kinases (MAPKs) that respond to stress stimuli. The stress-activated MAPKs associated with apoptotic cell death play vital roles in mammalian cells. Alnus hirsuta, which contains abundant diarylheptanoids derivatives, is a valuable medicinal plant. The CHCl [...] Read more.
JNK and p38 are important mitogen-activated protein kinases (MAPKs) that respond to stress stimuli. The stress-activated MAPKs associated with apoptotic cell death play vital roles in mammalian cells. Alnus hirsuta, which contains abundant diarylheptanoids derivatives, is a valuable medicinal plant. The CHCl3 extract (AHC) containing platyphyllenone (1) and platyphyllone (3) as main compounds showed in vitro anticancer effects. We report the biological activities of A. hirsuta extract associated with the regulation of apoptosis and JNK and p38 in MCF-7 breast cancer cells. Levels of phospho-JNK and phospho-p38 by AHC treatment were evaluated by enzyme-linked immunosorbent assay (ELISA). ROS production, apoptotic effect, and DNA contents of the cells were measured by flow cytometry. The two diarylheptanoids 1 and 3 and the AHC extract exhibited cytotoxic effects on MCF-7 cells in MTT assay, with IC50 values of 18.1, 46.9, 260.0 μg/mL, respectively. AHC induced ROS generation and elevated the endogenous levels of phospho-JNK and phospho-p38. AHC resulted in apoptosis and cell cycle arrest. We suggest that the antitumor effect of A. hirsuta extract is achieved by apoptosis promotion and cell cycle arrest mediated by the activation of JNK and p38 signaling pathway via ROS generation. Full article
(This article belongs to the Special Issue Natural Products for Cancer Chemoprevention)
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Open AccessReview
Myeloid-Derived Suppressor Cells as a Therapeutic Target for Cancer
Cells 2020, 9(3), 561; https://doi.org/10.3390/cells9030561 (registering DOI) - 27 Feb 2020
Abstract
The emergence of immunotherapy has been an astounding breakthrough in cancer treatments. In particular, immune checkpoint inhibitors, targeting PD-1 and CTLA-4, have shown remarkable therapeutic outcomes. However, response rates from immunotherapy have been reported to be varied, with some having pronounced success and [...] Read more.
The emergence of immunotherapy has been an astounding breakthrough in cancer treatments. In particular, immune checkpoint inhibitors, targeting PD-1 and CTLA-4, have shown remarkable therapeutic outcomes. However, response rates from immunotherapy have been reported to be varied, with some having pronounced success and others with minimal to no clinical benefit. An important aspect associated with this discrepancy in patient response is the immune-suppressive effects elicited by the tumour microenvironment (TME). Immune suppression plays a pivotal role in regulating cancer progression, metastasis, and reducing immunotherapy success. Most notably, myeloid-derived suppressor cells (MDSC), a heterogeneous population of immature myeloid cells, have potent mechanisms to inhibit T-cell and NK-cell activity to promote tumour growth, development of the pre-metastatic niche, and contribute to resistance to immunotherapy. Accumulating research indicates that MDSC can be a therapeutic target to alleviate their pro-tumourigenic functions and immunosuppressive activities to bolster the efficacy of checkpoint inhibitors. In this review, we provide an overview of the general immunotherapeutic approaches and discuss the characterisation, expansion, and activities of MDSCs with the current treatments used to target them either as a single therapeutic target or synergistically in combination with immunotherapy. Full article
Open AccessArticle
Improving Sea Level Anomaly Precision from Satellite Altimetry Using Parameter Correction in the Red Sea
Remote Sens. 2020, 12(5), 764; https://doi.org/10.3390/rs12050764 (registering DOI) - 27 Feb 2020
Abstract
An improved Fourier series model (FSM01) method is used in geophysical and environmental corrections to enhance the final product of the along-track Jason-2 sea level anomaly (SLA) data and extend it near the Red Sea borders. In this study, the ionospheric correction range, [...] Read more.
An improved Fourier series model (FSM01) method is used in geophysical and environmental corrections to enhance the final product of the along-track Jason-2 sea level anomaly (SLA) data and extend it near the Red Sea borders. In this study, the ionospheric correction range, wet tropospheric correction range, sea state bias correction range, and dry tropospheric correction range are enhanced and improved using FSM01, which helped to retrieve three more tracks (106, 170, and 234) earlier neglected by the distribution centers and extend the tracks toward the coast. The FSM01 SLA is compared with Jason-2 SLA and Archiving Validation and Interpretation of Satellite Oceanographic (AVISO) SLA for the available five tracks, in which the FSM01 SLA shows a good agreement and higher correlation with the Jason-2 SLA compared with that of AVISO, in addition to filling the gaps in the times series of all tracks. The newly retrieved tracks are also compared with those retrieved by AVISO, and both data points show similar variability, with FSM01 SLA showing no gaps in the time series. The FSM01 SLA was also extended toward the coast and showed high correlation with the coastal tide measurements. Full article
(This article belongs to the Section Ocean Remote Sensing)
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Open AccessReview
Hypovitaminosis D and Aging: Is There a Role in Muscle and Brain Health?
Nutrients 2020, 12(3), 628; https://doi.org/10.3390/nu12030628 (registering DOI) - 27 Feb 2020
Abstract
The older-adult population is constantly increasing, hence aging and mechanisms leading to aging are a topic raising increasing interest. Hypovitaminosis D is common amongst old patients and has been proposed as causative of several chronic diseases. Here we review the role of hypovitaminosis [...] Read more.
The older-adult population is constantly increasing, hence aging and mechanisms leading to aging are a topic raising increasing interest. Hypovitaminosis D is common amongst old patients and has been proposed as causative of several chronic diseases. Here we review the role of hypovitaminosis D and vitamin D supplementation in sarcopenia and dementia, from bench to bedside. Full article
(This article belongs to the Special Issue Vitamin D in Health and the Prevention and Treatment of Disease)
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Open AccessArticle
How Overtourism Threatens Large Urban Areas: A Case Study of the City of Wrocław, Poland
Sustainability 2020, 12(5), 1783; https://doi.org/10.3390/su12051783 (registering DOI) - 27 Feb 2020
Abstract
Excessive tourist traffic concentration in cities of high tourist attractiveness often leads to overtourism, manifested, among others, by overcrowding in appealing areas and means of transport, rising prices, or degradation of natural and cultural resources. The effects of an excessive number of tourists [...] Read more.
Excessive tourist traffic concentration in cities of high tourist attractiveness often leads to overtourism, manifested, among others, by overcrowding in appealing areas and means of transport, rising prices, or degradation of natural and cultural resources. The effects of an excessive number of tourists include an unfavourable change in the local community’s attitude towards tourists. The paper determines the extent and forms of overtourism symptoms in Wrocław, Poland. The research allowed for the identification of negative and positive effects of tourist traffic in Wrocław as perceived by three groups of respondents: experts, Wrocław residents: key experts from the scientific, administrative, planning, and business communities; people directly involved in tourist services; and students of tourism. The crucial part was direct research, conducted in November 2019 with a questionnaire technique. The results confirm symptoms of overtourism in Wrocław, but the threat is not significant. The article shows specific potential overtourism threat factors; the respondents’ opinions did not significantly differ between the groups. The presented findings and conclusions may be useful in developing the tourism policy of this and other cities, especially regarding sustainable development of tourism and the potential threat imposed by overtourism. The methodology may be used in similar comparative studies in other cities. Full article
Open AccessFeature PaperArticle
On the Formation and Stability of Chitosan/Hyaluronan-Based Complex Coacervates
Molecules 2020, 25(5), 1071; https://doi.org/10.3390/molecules25051071 (registering DOI) - 27 Feb 2020
Abstract
This contribution is aimed at extending our previous findings on the formation and stability of chitosan/hyaluronan-based complex coacervates. Colloids are herewith formed by harnessing electrostatic interactions between the two polyelectrolytes. The presence of tiny amounts of the multivalent anion tripolyphosphate (TPP) in the [...] Read more.
This contribution is aimed at extending our previous findings on the formation and stability of chitosan/hyaluronan-based complex coacervates. Colloids are herewith formed by harnessing electrostatic interactions between the two polyelectrolytes. The presence of tiny amounts of the multivalent anion tripolyphosphate (TPP) in the protocol synthesis serves as an adjuvant “point-like” cross-linker for chitosan. Hydrochloride chitosans at different viscosity average molar mass, , in the range 10,000–400,000 g/mol, and fraction of acetylated units, FA, (0.16, 0.46 and 0.63) were selected to fabricate a large library of formulations. Concepts such as coacervate size, surface charge and homogeneity in relation to chitosan variables are herein disclosed. The stability of coacervates in Phosphate Buffered Saline (PBS) was verified by means of scattering techniques, i.e., Dynamic Light Scattering (DLS) and Small-Angle X-ray Scattering (SAXS). The conclusions from this set of experiments are the following: (i) a subtle equilibrium between chitosan FA and does exist in ensuring colloidal stability; (ii) once diluted in PBS, osmotic swelling-driven forces trigger the enlargement of the polymeric mesh with an ensuing increase of coacervate size and porosity. Full article
(This article belongs to the Special Issue Novel Polysaccharide Materials)
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Open AccessArticle
Microbiological and Immunological Markers in Milk and Infant Feces for Common Gastrointestinal Disorders: A Pilot Study
Nutrients 2020, 12(3), 634; https://doi.org/10.3390/nu12030634 (registering DOI) - 27 Feb 2020
Abstract
The objective of this pilot study was to assess the fecal microbiome and different immunological parameters in infant feces and maternal milk from mother–infant pairs in which the infants were suffering from different gastrointestinal disorders (colic, non-IgE-mediated cow milk protein allergy (CMPA), and [...] Read more.
The objective of this pilot study was to assess the fecal microbiome and different immunological parameters in infant feces and maternal milk from mother–infant pairs in which the infants were suffering from different gastrointestinal disorders (colic, non-IgE-mediated cow milk protein allergy (CMPA), and proctocolitis). A cohort of 30 mother–infant pairs, in which the infants were diagnosed with these gastrointestinal disorders or included as healthy controls, were recruited. Bacterial composition of infant feces and breast milk was determined by metataxonomic sequencing. Immunological compounds were quantified using multiplexed immunoassays. A higher abundance of Eggerthellaceae, Lachnospiraceae and Peptostreptococcaceae, and lower abundance of Bifidobacterium and higher abundance of Rothia were registered in fecal samples from the CMPA group. Eggerthellaceae was also significantly more abundant in milk samples of the CMPA group. There were no differences in the concentration of immunological compounds in infant fecal samples between the four groups. In contrast, differences were found in the concentration and/or frequency of compounds related to acquired immunity and granulocyte colony stimulating factor (GCSF) in breast milk samples. In conclusion, a few microbial signatures in feces may explain part of the difference between CMPA and other infants. In addition, some milk immunological signatures have been uncovered among the different conditions addressed in this pilot study. Full article
(This article belongs to the Special Issue Impact of Dietary Components on Gut Microbiota)
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Open AccessArticle
Optimized Bioproduction of Itaconic and Fumaric Acids Based on Solid-State Fermentation of Lignocellulosic Biomass
Molecules 2020, 25(5), 1070; https://doi.org/10.3390/molecules25051070 (registering DOI) - 27 Feb 2020
Abstract
The bioproduction of high-value chemicals such as itaconic and fumaric acids (IA and FA, respectively) from renewable resources via solid-state fermentation (SSF) represents an alternative to the current bioprocesses of submerged fermentation using refined sugars. Both acids are excellent platform chemicals with a [...] Read more.
The bioproduction of high-value chemicals such as itaconic and fumaric acids (IA and FA, respectively) from renewable resources via solid-state fermentation (SSF) represents an alternative to the current bioprocesses of submerged fermentation using refined sugars. Both acids are excellent platform chemicals with a wide range of applications in different market, such as plastics, coating, or cosmetics. The use of lignocellulosic biomass instead of food resources (starch or grains) in the frame of a sustainable development for IA and FA bioproduction is of prime importance. Filamentous fungi, especially belonging to the Aspergillus genus, have shown a great capacity to produce these organic dicarboxylic acids. This study attempts to develop and optimize the SSF conditions with lignocellulosic biomasses using A. terreus and A. oryzae to produce IA and FA. First, a kinetic study of SSF was performed with non-food resources (wheat bran and corn cobs) and a panel of pH and moisture conditions was studied during fermentation. Next, a new process using an enzymatic cocktail simultaneously with SSF was investigated in order to facilitate the use of the biomass as microbial substrate. Finally, a large-scale fermentation process was developed for SSF using corn cobs with A. oryzae; this specific condition showed the best yield in acid production. The yields achieved were 0.05 mg of IA and 0.16 mg of FA per gram of biomass after 48 h. These values currently represent the highest reported productions for SSF from raw lignocellulosic biomass. Full article
(This article belongs to the Special Issue Lignocellulosic Biomass)
Open AccessArticle
Surface Roughness Changes Induced by Stoichiometric Deviation in Ambient Phase for Two-Component Semiconductor Crystals
Crystals 2020, 10(3), 151; https://doi.org/10.3390/cryst10030151 (registering DOI) - 27 Feb 2020
Abstract
The effects of a deviation in the fraction of the components in the ambient phase of a stoichiometric AB compound, such as GaN or SiC crystals, on the surface roughness and step self-assembly and disassembly on a vicinal surface are studied using the [...] Read more.
The effects of a deviation in the fraction of the components in the ambient phase of a stoichiometric AB compound, such as GaN or SiC crystals, on the surface roughness and step self-assembly and disassembly on a vicinal surface are studied using the Monte Carlo method based on a staggered restricted solid-on-solid (st-RSOS) model at equilibrium. The (001) and (111) surfaces are typical examples of non-polar and polar surfaces, respectively. Although a stoichiometric deviation of the ambient phase does not affect the surface energy of a non-polar surface, it affects that of polar surfaces such as the ( 111 ) A and ( 111 ) B surfaces. We found that the vicinal surface of an AB compound is atomically smooth and globally rough. Globally, the vicinal surface is not affected by a stoichiometric deviation in the ambient phase. In contrast, in a small area, the structure of the vicinal surface is affected by a stoichiometric deviation in the ambient phase. The vicinal surface consists of local double and quadruple steps. The characteristic length L M F L , which separates the global length scale region and the local length scale region, has a maximum value of 156 a in the present study, where a is the lattice constant. When temperature decreases, L M F L can become large. Full article
(This article belongs to the Section Crystal Engineering)
Open AccessFeature PaperArticle
A New Simple Screening Tool—4QT: Can It Identify Those with Swallowing Problems? A Pilot Study
Geriatrics 2020, 5(1), 11; https://doi.org/10.3390/geriatrics5010011 (registering DOI) - 27 Feb 2020
Abstract
As people and the population age, the prevalence of swallowing problems (dysphagia) increases. The screening for dysphagia is considered good practice in stroke care, yet is not routinely undertaken in the management of frail older adults. A short swallow screen, the 4QT, was [...] Read more.
As people and the population age, the prevalence of swallowing problems (dysphagia) increases. The screening for dysphagia is considered good practice in stroke care, yet is not routinely undertaken in the management of frail older adults. A short swallow screen, the 4QT, was developed following a review of the literature. The screen has four questions relating to swallowing that can be asked by a member of the health care team. A convenience sample of 48 older frail patients on an acute frailty ward was recruited into a Quality Improvement project. Their swallow was screened using the EAT-10 and 4QT. A speech and language therapist assessed for the presence of dysphagia using a standardised assessment for dysphagia. The 4QT was as effective as the EAT-10 in identifying older frail adults with potential swallowing problems (Κ = 0.73). The 4QT has 100% sensitivity, 80.4% specificity and positive predictive value (PPV) 50%, negative predictive value (NPV) 100%. The 4QT is a highly sensitive but not specific swallow screen, only 50% of people reporting swallowing problems were confirmed to have a degree of dysphagia by the SLT. The 4QT is a simple screening tool that could be used by all staff, but requires further research/evaluation before it is widely accepted into clinical practice. Full article
(This article belongs to the Special Issue The Rehabilitation and Management of Dysphagia)

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