Accelerating Open Access.
MDPI is a pioneer in scholarly open access publishing
and has supported academic communities since 1996.
Open AccessArticle
Theoretical Basis for Switching a Kramers Single Molecular Magnet by Circularly-Polarized Radiation
Materials 2019, 12(23), 3865; https://doi.org/10.3390/ma12233865 - 22 Nov 2019
Abstract
The d-group Kramers ions, having strong zero field splitting (ZFS) with axial symmetry and a negative D value for the ZFS Hamiltonian, are widely considered as candidates for use as single molecular magnets (SMMs). An important need is the means to switch [...] Read more.
The d-group Kramers ions, having strong zero field splitting (ZFS) with axial symmetry and a negative D value for the ZFS Hamiltonian, are widely considered as candidates for use as single molecular magnets (SMMs). An important need is the means to switch the SMM between its states in a reasonably short and predictable period of time, which is generally not available. We propose an approach, Zeeman–far infrared (ZeFIR) double resonance, in which circularly polarized alternating magnetic fields in the far infrared (FIR) range induce selective magnetic dipole transitions between different Kramers doublets of the SMM and polarized microwave (mw) pulses transfer excitation inside the upper Kramers doublet. A combination of FIR and mw pulses allows unidirectional switching between +S and –S states of the ion. The proposed approach is considered for a model quartet system with total spin S = 3/2, which seems to be the most promising object for selective resonance manipulations of its states by circularly polarized radiation. Full article
(This article belongs to the Special Issue Advances in Molecular Magnetic Materials)
Show Figures

Graphical abstract

Open AccessReview
Nanoengineering of Gold Nanoparticles: Green Synthesis, Characterization, and Applications
Crystals 2019, 9(12), 612; https://doi.org/10.3390/cryst9120612 - 22 Nov 2019
Abstract
The fundamental aspects of the manufacturing of gold nanoparticles (AuNPs) are discussed in this review. In particular, attention is devoted to the development of a simple and versatile method for the preparation of these nanoparticles. Eco-friendly synthetic routes, such as wet chemistry and [...] Read more.
The fundamental aspects of the manufacturing of gold nanoparticles (AuNPs) are discussed in this review. In particular, attention is devoted to the development of a simple and versatile method for the preparation of these nanoparticles. Eco-friendly synthetic routes, such as wet chemistry and biosynthesis with the aid of polymers, are of particular interest. Polymers can act as reducing and/or capping agents, or as soft templates leading to hybrid nanomaterials. This methodology allows control of the synthesis and stability of nanomaterials with novel properties. Thus, this review focus on a fundamental study of AuNPs properties and different techniques to characterize them, e.g., Transmission Electron Microscopy (TEM), Atomic Force Microscopy (AFM), UV-Visible spectroscopy, Dynamic Light Scattering (DLS), X-Ray Diffraction (XRD), X-Ray Photoelectron Spectroscopy, Small-angle X-Ray Scattering (SAXS), and rheology. Recently, AuNPs obtained by “green” synthesis have been applied in catalysis, in medicine, and as antibacterials, sensors, among others. Full article
(This article belongs to the Special Issue Synthesis and Investigation of Gold Nanoparticles)
Show Figures

Graphical abstract

Open AccessReview
Synthesis of Plasmonic Photocatalysts for Water Splitting
Catalysts 2019, 9(12), 982; https://doi.org/10.3390/catal9120982 - 22 Nov 2019
Abstract
Production of H2, O2, and some useful chemicals by solar water splitting is widely expected to be one of the ultimate technologies in solving energy and environmental problems worldwide. Plasmonic enhancement of photocatalytic water splitting is attracting much attention. [...] Read more.
Production of H2, O2, and some useful chemicals by solar water splitting is widely expected to be one of the ultimate technologies in solving energy and environmental problems worldwide. Plasmonic enhancement of photocatalytic water splitting is attracting much attention. However, the enhancement factors reported so far are not as high as expected. Hence, further investigation of the plasmonic photocatalysts for water splitting is now needed. In this paper, recent work demonstrating plasmonic photocatalytic water splitting is reviewed. Particular emphasis is given to the fabrication process and the morphological features of the plasmonic photocatalysts. Full article
(This article belongs to the Special Issue Plasmonic Photocatalysts)
Open AccessReview
The Burden of Fungal Infections in Ethiopia
J. Fungi 2019, 5(4), 109; https://doi.org/10.3390/jof5040109 - 22 Nov 2019
Abstract
The burden of severe fungal infections (FIs) is not well addressed in Ethiopia. We have estimated the burden of FIs from multiple demographic sources and by searching articles from PubMed. Opportunistic FIs were estimated using modelling and 2017 national HIV data. The burdens [...] Read more.
The burden of severe fungal infections (FIs) is not well addressed in Ethiopia. We have estimated the burden of FIs from multiple demographic sources and by searching articles from PubMed. Opportunistic FIs were estimated using modelling and 2017 national HIV data. The burdens of chronic pulmonary aspergillosis (CPA) and allergic bronchopulmonary aspergillosis (ABPA) were estimated by using the prevalence of asthma, chronic obstructive pulmonary disease, and annual the incidence of tuberculosis. Of the 105,000,000 estimated Ethiopian population, 610,000 are thought to have HIV infection. Our estimation of HIV-related FIs were: 9900 cryptococcal meningitis (CM), 12,700 Pneumocystis jirovecii pneumonia (PCP), 76,300 oral and 56,000 oesophageal candidiasis cases. A remarkable 7,051,700 4–14-year-olds probably have tinea capitis and 1,469,000 women probably have recurrent Candida vaginitis. There were 15,200 estimated CPA cases (prevalence) and 11,500 invasive aspergillosis (IA) cases (incidence). Data are scant, but we estimated 5300 candidaemia and 800 Candida peritonitis cases. In conclusion, approximately 8% of Ethiopians suffer from FIs annually, mostly schoolchildren with tinea capitis. IA, CM and PCP are the major causes of fungal deaths. The absence of CD4 count is challenging the identification of HIV patients at risk of opportunistic FIs. There is a pressing need to improve FI diagnosis, probably including national surveillance. Full article
Open AccessArticle
Effect of Rosmarinic Acid and Sinapic Acid on Oxidative Stress Parameters in the Cardiac Tissue and Serum of Type 2 Diabetic Female Rats
Antioxidants 2019, 8(12), 579; https://doi.org/10.3390/antiox8120579 - 22 Nov 2019
Abstract
Cardiovascular diseases are one of the most common complications of type 2 diabetes. They are considered the leading cause of death among diabetics. One of the mechanisms underlying diabetic cardiovascular complications is oxidative stress. Many phenolic acids are regarded as antioxidants. The aim [...] Read more.
Cardiovascular diseases are one of the most common complications of type 2 diabetes. They are considered the leading cause of death among diabetics. One of the mechanisms underlying diabetic cardiovascular complications is oxidative stress. Many phenolic acids are regarded as antioxidants. The aim of the study was to investigate the effect of rosmarinic acid (RA) and sinapic acid (SA) on oxidative stress parameters in the cardiac tissue and serum of type 2 diabetic female rats. Additionally, the effect of these compounds on glucose homeostasis and lipid profile in the serum was evaluated. Type 2 diabetes was induced with high-fat diet and streptozotocin. RA at the doses of 10 and 50 mg/kg and SA at the doses of 5 and 25 mg/kg were administrated orally for 28 days. Untreated diabetic rats exhibited unfavorable changes in glucose metabolism and lipid profile. Changes in the enzymatic and non-enzymatic markers indicated the onset of oxidative stress in these animals. The results showed that the higher doses of the tested phenolic acids—50 mg/kg of RA and 25 mg/kg of SA—revealed beneficial effects on oxidative stress in the cardiac tissue of diabetic rats. Full article
Open AccessFeature PaperArticle
Synergetic Application of Multi-Criteria Decision-Making Models to Credit Granting Decision Problems
Appl. Sci. 2019, 9(23), 5052; https://doi.org/10.3390/app9235052 - 22 Nov 2019
Abstract
Although various algorithms have widely been studied for bankruptcy and credit risk prediction, conclusions regarding the best performing method are divergent when using different performance assessment metrics. As a solution to this problem, the present paper suggests the employment of two well-known multiple-criteria [...] Read more.
Although various algorithms have widely been studied for bankruptcy and credit risk prediction, conclusions regarding the best performing method are divergent when using different performance assessment metrics. As a solution to this problem, the present paper suggests the employment of two well-known multiple-criteria decision-making (MCDM) techniques by integrating their preference scores, which can constitute a valuable tool for decision-makers and analysts to choose the prediction model(s) more properly. Thus, selection of the most suitable algorithm will be designed as an MCDM problem that consists of a finite number of performance metrics (criteria) and a finite number of classifiers (alternatives). An experimental study will be performed to provide a more comprehensive assessment regarding the behavior of ten classifiers over credit data evaluated with seven different measures, whereas the Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) and Preference Ranking Organization METHod for Enrichment of Evaluations (PROMETHEE) techniques will be applied to rank the classifiers. The results demonstrate that evaluating the performance with a unique measure may lead to wrong conclusions, while the MCDM methods may give rise to a more consistent analysis. Furthermore, the use of MCDM methods allows the analysts to weight the significance of each performance metric based on the intrinsic characteristics of a given credit granting decision problem. Full article
(This article belongs to the Section Computing and Artificial Intelligence)
Open AccessArticle
Do Students Really Use Internet Access for Learning in the Classroom? : Exploring Students’ Cyberslacking in an Indonesian University
Behav. Sci. 2019, 9(12), 123; https://doi.org/10.3390/bs9120123 - 22 Nov 2019
Abstract
University students, as ‘digital natives’, use the internet for learning in the classroom. However, the availability of internet access in the classroom becomes a challenge, because students also engage in non-academic internet access during lectures. The use of the internet during lectures for [...] Read more.
University students, as ‘digital natives’, use the internet for learning in the classroom. However, the availability of internet access in the classroom becomes a challenge, because students also engage in non-academic internet access during lectures. The use of the internet during lectures for non-academic purpose is called cyberslacking. Self-regulated learning (SRL) and media multi-tasking efficacy (MME) are considered to be important factors contributing to cyberslacking. The participants in this study were students in a private university in Indonesia (N = 423). The results show that only self-regulated learning made any significant contribution to cyberslacking in the classrooms. Further research should be conducted to consider external factors, such as instructors’ contributions, classrooms circumstances and the university policy towards internet usage. Full article
(This article belongs to the Special Issue XVI European Congress of Psychology)
Open AccessArticle
A Pathway Home: Connecting Museum Collections with Native Communities
Arts 2019, 8(4), 154; https://doi.org/10.3390/arts8040154 - 22 Nov 2019
Abstract
In 2016, the Smithsonian’s National Museum of the American Indian (NMAI) and the Poeh Cultural Center, owned and operated by the Pueblo of Pojoaque in New Mexico, begin work on a loan of 100 ceramics in NMAI’s collections to the Poeh Cultural Center. [...] Read more.
In 2016, the Smithsonian’s National Museum of the American Indian (NMAI) and the Poeh Cultural Center, owned and operated by the Pueblo of Pojoaque in New Mexico, begin work on a loan of 100 ceramics in NMAI’s collections to the Poeh Cultural Center. Making loans to other institutions is regular practice for NMAI. In making loans to tribal museums and cultural centers, a loan can take on cultural and spiritual significance, which was the case for the Poeh Cultural Center and the community members it supports and represents. This article addresses the importance of connecting Native peoples with museum collections, which has the potential to contribute to community well-being, by featuring the partnership between NMAI and the Poeh Cultural Center. Full article
Open AccessArticle
Schizosaccharomyces pombe can Reduce Acetic Acid Produced by Baijiu Spontaneous Fermentation Microbiota
Microorganisms 2019, 7(12), 606; https://doi.org/10.3390/microorganisms7120606 - 22 Nov 2019
Abstract
The spontaneous fermentation of alcoholic beverage is a bioprocess donated by microbiota with complex stress environments. Among various microbes, non-Saccharomyces yeasts have high stress tolerance and significantly affect the taste and quality of products in process. Although many researchers have focused on [...] Read more.
The spontaneous fermentation of alcoholic beverage is a bioprocess donated by microbiota with complex stress environments. Among various microbes, non-Saccharomyces yeasts have high stress tolerance and significantly affect the taste and quality of products in process. Although many researchers have focused on the influence of acid stress, the mechanism of non-Saccharomyces yeasts to tolerant stress remains unclear in microbiota. To bridge the gap, we constructed in situ and in vitro studies to explore the reduction pathway of acetic acid in non-Saccharomyces yeasts. In this study, we found Schizosaccharomyces pombe has special capacities to resist 10 g/L acetic acid in laboratory cultures and decrease the average concentration of acetic acid from 9.62 to 6.55 g/kg fermented grains in Chinese Maotai-flavor liquor (Baijiu) production. Moreover, Schi. pombe promoted metabolic level of mevalonate pathway (high expressions of gene ACCAT1, HMGCS1, and HMGCR1) to degrade a high concentration of acetic acid. Meanwhile, Schi. pombe also improved the concentration of mevalonic acid that is the precursor of terpenes to enhance the taste and quality of Baijiu. Overall, the synchronicity of reduction and generation in Schi. pombe advances the current knowledge to guide more suitable strategies for mechanism studies of non-Saccharomyces yeasts in fermented industries of alcoholic beverages. Full article
(This article belongs to the collection Feature Papers in Food Microbiology)
Open AccessFeature PaperArticle
Lattice Boltzmann Simulation on Droplet Flow through 3D Metal Foam
Processes 2019, 7(12), 877; https://doi.org/10.3390/pr7120877 - 22 Nov 2019
Abstract
The hydrodynamics of droplets passing through metal foam is investigated using the lattice Boltzmann method (LBM). The accurate 3D porous structure for the simulation is generated by X-ray micro-computed tomography. The simulated results are in good agreement with the experimental ones using high-speed [...] Read more.
The hydrodynamics of droplets passing through metal foam is investigated using the lattice Boltzmann method (LBM). The accurate 3D porous structure for the simulation is generated by X-ray micro-computed tomography. The simulated results are in good agreement with the experimental ones using high-speed video. The simulated results show that for droplets passing metal foam, there is a critical capillary number, Cac (around 0.061), above which the droplet continues to deform until it breaks up. The simulated results show that the capillary number, droplet size, pores diameter, and thickness of metal foam have the significant effect of droplets deforming and breaking up when the droplets pass through the metal foam. To avoid the calescence of two droplets at the inlet zone of the metal foam, the distance between droplets should be larger than three times the diameter of the droplet. Full article
(This article belongs to the Special Issue Smart Flow Control Processes in Micro Scale)
Show Figures

Graphical abstract

Open AccessArticle
Development of a Model Test System for a Piston Ring/Cylinder Liner-Contact with Focus on Near-to-Application Seizure Behaviour
Lubricants 2019, 7(12), 104; https://doi.org/10.3390/lubricants7120104 - 22 Nov 2019
Abstract
Physical simulations of tribo contacts in internal combustion engines can act as a supporting tool to match upcoming guidelines and emission restrictions. In particular, the scuffing resistance of the contact between the piston ring and cylinder liner suffers under decreasing oil viscosity and [...] Read more.
Physical simulations of tribo contacts in internal combustion engines can act as a supporting tool to match upcoming guidelines and emission restrictions. In particular, the scuffing resistance of the contact between the piston ring and cylinder liner suffers under decreasing oil viscosity and limitation of antiwear additives. This paper aims to provide an experimental method to simulate the scuffing of the piston ring/cylinder liner-contact and to validate this method with real engine parts and the literature from engine tests. The experimental methodology uses a linear tribometer TE77 to test specimens from original piston rings and liners under reciprocating motion. Additionally, the ring specimen is given the opportunity to perform secondary movements (ring twisting, ring turning) and to run under deficient lubrication conditions similar to the engine. A specially designed test strategy enables the reproducible creation of seizure of the tribosystem. The seizure resistance of two engine oils, tested for validation, correlates with the known engine performance. Therefore, the model test system can be seen as a reproducible tool for simulating seizure of a ring/liner-system, showing similar trends and wear mechanisms as in an engine. Surface analysis depicts similarities between the scuffed surfaces of an engine and the model and discusses the origin of seizure based on the model specimens together with the relevant literature. Full article
Show Figures

Graphical abstract

Open AccessArticle
Glutathione Deficiency and Alterations in the Sulfur Amino Acid Homeostasis during Early Postnatal Development as Potential Triggering Factors for Schizophrenia-Like Behavior in Adult Rats
Molecules 2019, 24(23), 4253; https://doi.org/10.3390/molecules24234253 - 22 Nov 2019
Abstract
Impaired glutathione (GSH) synthesis and dopaminergic transmission are important factors in the pathophysiology of schizophrenia. Our research aimed to assess the effects of l-buthionine-(S,R)-sulfoximine (BSO), a GSH synthesis inhibitor, and GBR 12909, a dopamine reuptake inhibitor, administered alone [...] Read more.
Impaired glutathione (GSH) synthesis and dopaminergic transmission are important factors in the pathophysiology of schizophrenia. Our research aimed to assess the effects of l-buthionine-(S,R)-sulfoximine (BSO), a GSH synthesis inhibitor, and GBR 12909, a dopamine reuptake inhibitor, administered alone or in combination, to Sprague–Dawley rats during early postnatal development (p5–p16), on the levels of GSH, sulfur amino acids, global DNA methylation, and schizophrenia-like behavior. GSH, methionine (Met), homocysteine (Hcy), and cysteine (Cys) contents were determined in the liver, kidney, and in the prefrontal cortex (PFC) and hippocampus (HIP) of 16-day-old rats. DNA methylation in the PFC and HIP and schizophrenia-like behavior were assessed in adulthood (p90–p93). BSO caused the tissue-dependent decreases in GSH content and alterations in Met, Hcy, and Cys levels in the peripheral tissues and in the PFC and HIP. The changes in these parameters were accompanied by alterations in the global DNA methylation in the studied brain structures. Parallel to changes in the global DNA methylation, deficits in the social behaviors and cognitive functions were observed in adulthood. Only BSO + GBR 12909-treated rats exhibited behavioral alterations resembling positive symptoms in schizophrenia patients. Our results suggest the usefulness of this neurodevelopmental model for research on the pathomechanism of schizophrenia. Full article
(This article belongs to the Special Issue Sulfur Compounds and Human Health)
Show Figures

Figure 1

Open AccessReview
Pediatric Endoscopy, Update 2020
Appl. Sci. 2019, 9(23), 5036; https://doi.org/10.3390/app9235036 - 22 Nov 2019
Abstract
Optimal management of pediatric endoscopy requires a multidisciplinary approach. In most hospitals, endoscopy in pediatric patients is performed by conventional gastroenterologists and only a few centers have specialized pediatric gastroenterologists. This is due to the fact that the number of pediatric gastroenterologists is [...] Read more.
Optimal management of pediatric endoscopy requires a multidisciplinary approach. In most hospitals, endoscopy in pediatric patients is performed by conventional gastroenterologists and only a few centers have specialized pediatric gastroenterologists. This is due to the fact that the number of pediatric gastroenterologists is limited and not all of them are experienced in endoscopic techniques. However, there are also some pediatric centers offering a high-quality and high-volume endoscopy service provided by very experienced pediatric gastroenterologists. Up to now, the literature on pediatric endoscopy is rather sparse. In this article, we describe current knowledge and practice of endoscopic procedures in pediatric patients, which should be relevant for both the adult and pediatric gastroenterologists. Full article
(This article belongs to the Special Issue Ultrasound Technology for Clinical Diagnosis and Decisions Making)
Open AccessEditorial
Sentiment Analysis for Social Media
Appl. Sci. 2019, 9(23), 5037; https://doi.org/10.3390/app9235037 - 22 Nov 2019
Abstract
Sentiment analysis has become a key technology to gain insight from social networks. The field has reached a level of maturity that paves the way for its exploitation in many different fields such as marketing, health, banking or politics. The latest technological advancements, [...] Read more.
Sentiment analysis has become a key technology to gain insight from social networks. The field has reached a level of maturity that paves the way for its exploitation in many different fields such as marketing, health, banking or politics. The latest technological advancements, such as deep learning techniques, have solved some of the traditional challenges in the area caused by the scarcity of lexical resources. In this Special Issue, different approaches that advance this discipline are presented. The contributed articles belong to two broad groups: technological contributions and applications. Full article
(This article belongs to the Special Issue Sentiment Analysis for Social Media)

Open Access Journals

Browse by Indexing Browse by Subject Selected Journals
Back to TopTop