bluuebunny/crossref_metadata_2025 huggingface dataset:
Genetic Regulators and Physiological Significance of Glycogen Storage in Candida albicans
Authors: Zeitz Marcus A. , Tanveer Zainab , Openshaw Anatole T. , Schmidt Martin
Published: October 2019

The dimorphic human fungal pathogen C. albicans has broad metabolic flexibility that allows it to adapt to the nutrient conditions in different host habitats. C. albicans builds large carbohydrate stores (glycogen) at the end of exponential growth and begins consumption of stored carbohydrates when nutrients become limiting. The expression of genes required for the successful transition between host environments, including the factors controlling glycogen content, is controlled by protein kinase A signaling through the transcription factor Efg1. In addition to the inability to transition to hyphal growth, C. albicans efg1 mutants have low glycogen content and reduced long-term survival, suggesting that carbohydrate storage is required for viability during prolonged culture. To test this assumption, we constructed a glycogen-deficient C. albicans mutant and assessed its viability during extended culture. Pathways and additional genetic factors controlling C. albicans glycogen synthesis were identified through the screening of mutant libraries for strains with low glycogen content. Finally, a part of the Efg1-regulon was screened for mutants with a shortened long-term survival phenotype. We found that glycogen deficiency does not affect long-term survival, growth, metabolic flexibility or morphology of C. albicans. We conclude that glycogen is not an important contributor to C. albicans fitness.
Towards Responsible Consolidation of Customary Lands: A Research Synthesis
Authors: Asiama Kwabena , Bennett Rohan , Zevenbergen Jaap
Published: October 2019

The use of land consolidation on customary lands has been limited, though land fragmentation persists. Land fragmentation on customary lands has two main causes—the nature of the customary land tenure system, and the somewhat linked agricultural system. Since attempts to increase food productivity on customary lands have involved fertilisation and mechanisation on the small and scattered farmlands, these approaches have fallen short of increasing food productivity. A study to develop a responsible approach to land consolidation on customary lands using a design research approach is undertaken and reported here. Based on a comparative study, it is found that three factors inhibit the development of a responsible land consolidation approach on customary lands—the coverage of a land administration system, a land valuation approach, and a land reallocation approach the fits the customary land tenure system. To fill these gaps, firstly, this study developed the participatory land administration that brought together traditional land administration approaches with emerging bottom-up approaches, as well as technological advances that drive these approaches together with the growing societal needs. Secondly, a valuation approach was developed to enable the comparison of the farmlands in rural areas that are without land markets. Finally, a land reallocation approach was developed based on the political, economic and social, as well as technical and legal characteristics of rural customary farmlands. This study concludes that though the land consolidation strategy developed is significantly able to reduce land fragmentation, both physical and land tenure, the local customs are an obstruction to the technical processes to achieve the best form of farmland structures.
In-situ Cu Coating on Steel Surface after Oxidizing at High Temperature
Authors: Li Na , Jia Ruizhi , Zhang Hongmei , Sha Wei , Li Yan , Jiang Zhengyi
Published: October 2019

Almost all copper in scrap steel is recovered, so research on copper-bearing steel has profound practical significance. The surface enrichment of copper occurs in all copper-bearing steels studied in this paper after being heated at high temperature. In-situ oxidation-induced copper coatings were discovered on the descaled copper-bearing steels after heating at around 1150 °C for 2 h in air. Scattered copper precipitates in or under rust after heating at a lower temperature. A new concept was created using in-situ composites prepared by direct oxidation of matrix, and there was no bonding problem found between the coating and the matrix. The enrichment form of copper in steel is related to the oxidation rate, oxidation time, heating temperature and copper content.
Supported ITZ Modification Efficiencies via Surface Coating Nanoparticles on Aggregate and its Influence on Properties
Authors: Wu Kai , Han Hao , Xu Linglin , Yang Xiaojie , De Schutter Geert
Published: October 2019

In order to modify the porous interfacial transition zone (ITZ) microstructure of concrete more efficiently, a method of coating aggregate surfaces by using several nanoparticles was evaluated in this study. The compressive strength, chloride penetration of sound, and pre-loading samples were assessed in relation to the type of coating materials used (slag, nano-CaCO3, and nano-SiO2) and the designed coating thickness (5, 10, and 15 μm). The ITZ microstructure was quantitatively determined via Backscattered electron (BSE) image analysis. Results showed that the overall performance of concrete is highly dependent on the coating materials and the designed coating thickness. Increasing the coating thickness of slag and nano-SiO2 could improve the chloride penetration resistance but decrease the compressive strength. Using nano-CaCO3 to coat the aggregate leads to a significant reduction in the properties of the so-prepared concrete. Though coating inert fine particles around aggregate could disturb the initial particle packing and modify the ITZ, it is not able to improve the overall concrete properties. Coating aggregate could determine the ITZ microstructure, especially within the region that is around 30 μm away from aggregate surface.
A Study of the Synergistic Interaction of Konjac Glucomannan/Curdlan Blend Systems under Alkaline Conditions
Authors: Ye Weijian , Yan Bowen , Pang Jie , Fan Daming , Huang Jianlian , Zhou Wenguo , Cheng Xueqian , Chen Hui , Zhang Hao
Published: October 2019

To improve the gelation performance of konjac glucomannan (KGM) thermo-irreversible gel in the condition of alkaline, this study investigated the interactions between KGM and curdlan (CUD) in terms of the sol state and gelation process. The apparent viscosity, rheological properties during heating and cooling, thermodynamic properties, gelation properties and water holding capacity of KGM/CUD blend systems in an alkaline environment were studied using physical property testing instruments and methods. The results showed that the viscosity of the KGM/CUD blended solution was greater than the value calculated from the ideal mixing rules in the condition of alkaline (pH = 10.58). As the proportion of CUD in the system increased, the intersection of storage modulus (G’) and loss modulus (G”) shifted to low frequencies, the relaxation time gradually increased, and the degree of entanglement of molecular chains between these two components gradually increased. The addition of CUD helped decrease the gelation temperature of KGM, increased the gelation rate and inhibited the thinning phenomenon of KGM gels at low temperatures (2–20 °C). The addition of CUD increased the hardness and gel strength of KGM but did not significantly improve the water holding capacity of the KGM/CUD blend gel. The process of mixing KGM and CUD improved the thermal stability of the gel. In summary, KGM/CUD exhibited excellent compatibility under alkaline conditions, and the blend systems produced a “viscosifying effect”. KC8 and KC5 show better thermal stability, low temperature resistance and gel strength compared to KGM. This blended gel can be used as a structural support material to provide reference for the development of konjac bionic vegetarian products.
Electromechanical Properties of PVDF-Based Polymers Reinforced with Nanocarbonaceous Fillers for Pressure Sensing Applications
Authors: Vicente Javier , Costa P. , Lanceros-Mendez S. , Abete Jose Manuel , Iturrospe Aitzol
Published: October 2019

Polymer-based composites reinforced with nanocarbonaceous materials can be tailored for functional applications. Poly(vinylidene fluoride) (PVDF) reinforced with carbon nanotubes (CNT) or graphene with different filler contents have been developed as potential piezoresistive materials. The mechanical properties of the nanocomposites depend on the PVDF matrix, filler type, and filler content. PVDF 6010 is a relatively more ductile material, whereas PVDF-HFP (hexafluropropylene) shows larger maximum strain near 300% strain for composites with CNT, 10 times higher than the pristine polymer. This behavior is similar for all composites reinforced with CNT. On the other hand, reduced graphene oxide (rGO)/PVDF composites decrease the maximum strain compared to neat PVDF. It is shown that the use of different PVDF copolymers does not influence the electrical properties of the composites. On the other hand, CNT as filler leads to composites with percolation threshold around 0.5 wt.%, whereas rGO nanocomposites show percolation threshold at ≈ 2 wt.%. Both nanocomposites present excellent linearity between applied pressure and resistance variation, with pressure sensibility (PS) decreasing with applied pressure, from PS ≈ 1.1 to 0.2 MPa−1. A proof of concept demonstration is presented, showing the suitability of the materials for industrial pressure sensing applications.
Recent Progress in Nanomaterials for Modern Concrete Infrastructure: Advantages and Challenges
Authors: Bautista-Gutierrez Karla P. , Herrera-May Agustín L. , Santamaría-López Jesús M. , Honorato-Moreno Antonio , Zamora-Castro Sergio A.
Published: October 2019

Modern concrete infrastructure requires structural components with higher mechanical strength and greater durability. A solution is the addition of nanomaterials to cement-based materials, which can enhance their mechanical properties. Some such nanomaterials include nano-silica (nano-SiO2), nano-alumina (nano-Al2O3), nano-ferric oxide (nano-Fe2O3), nano-titanium oxide (nano-TiO2), carbon nanotubes (CNTs), graphene and graphene oxide. These nanomaterials can be added to cement with other reinforcement materials such as steel fibers, glass, rice hull powder and fly ash. Optimal dosages of these materials can improve the compressive, tensile and flexural strength of cement-based materials, as well as their water absorption and workability. The use of these nanomaterials can enhance the performance and life cycle of concrete infrastructures. This review presents recent researches about the main effects on performance of cement-based composites caused by the incorporation of nanomaterials. The nanomaterials could decrease the cement porosity, generating a denser interfacial transition zone. In addition, nanomaterials reinforced cement can allow the construction of high-strength concrete structures with greater durability, which will decrease the maintenance requirements or early replacement. Also, the incorporation of nano-TiO2 and CNTs in cementitious matrices can provide concrete structures with self-cleaning and self-sensing abilities. These advantages could help in the photocatalytic decomposition of pollutants and structural health monitoring of the concrete structures. The nanomaterials have a great potential for applications in smart infrastructure based on high-strength concrete structures.
Resistance of Geosynthetics against the Isolated and Combined Effect of Mechanical Damage under Repeated Loading and Abrasion
Authors: Almeida Filipe , Carlos David Miranda , Carneiro José Ricardo , Lopes Maria de Lurdes
Published: October 2019

The behaviour of materials used for developing engineering structures should be properly foreseen during the design phase. Regarding geosynthetics, which are construction materials used in a wide range of engineering structures, the installation on site and the action of many degradation agents during service life may promote changes in their properties, endangering the structures in which they are applied. The evaluation of the damage suffered by geosynthetics, like installation damage or abrasion, is often carried out through laboratory tests. This work studied the behaviour of five geosynthetics (three geotextiles and two geogrids) after being individually and successively exposed to two degradation tests: mechanical damage under repeated loading and abrasion. The short-term mechanical and hydraulic behaviours of the geosynthetics were analysed by performing tensile tests and water permeability normal to the plane tests. Reduction factors were determined based on the changes occurred in the tensile strength of the geosynthetics. Findings showed that mechanical damage under repeated loading and abrasion tended to affect the mechanical and hydraulic properties of the geosynthetics and that the reduction factors calculated according to the traditional method may not be able to represent accurately the damage suffered by the materials when exposed successively to the degradation mechanisms.
A Novel Micro-Contact Stiffness Model for the Grinding Surfaces of Steel Materials Based on Cosine Curve-Shaped Asperities
Authors: An Qi , Suo Shuangfu , Lin Fuyan , Shi Jianwen
Published: October 2019

Contact stiffness is an important parameter for describing the contact behavior of rough surfaces. In this study, to more accurately describe the contact stiffness between grinding surfaces of steel materials, a novel microcontact stiffness model is proposed. In this model, the novel cosine curve-shaped asperity and the conventional Gauss distribution are used to develop a simulated rough surface. Based on this simulated rough surface, the analytical expression of the microcontact stiffness model is obtained using contact mechanics theory and statistical theory. Finally, an experimental study of the contact stiffness of rough surfaces was conducted on different steel materials of various levels of roughness. The comparison results reveal that the prediction results of the present model show the same trend as that of the experimental results; the contact stiffness increases with increasing contact pressure. Under the same contact pressure, the present model is closer to the experimental results than the already existing elastic–plastic contact (CEB) and finite-element microcontact stiffness (KE) models, whose hypothesis of a single asperity is hemispherical. In addition, under the same contact pressure, the contact stiffness of the same steel material decreases with increasing roughness, whereas the contact stiffness values of different steel materials under the same roughness show only small differences. The correctness and accuracy of the present model can be demonstrated by analyzing the measured asperity geometry of steel materials and experimental results.
Fresh-State and Mechanical Properties of High-Performance Self-Compacting Concrete with Recycled Aggregates from the Precast Industry
Authors: Barroqueiro Tiago , da Silva Pedro R. da , de Brito Jorge de
Published: October 2019

The urgent need to change the less positive impacts of the construction industry on the environment, and more specifically the production and use of concrete, is the main motivation for the research for more efficient and environmentally sustainable solutions. This paper presented the results of an experimental campaign whose ultimate goal was to produce high-performance self-compacting concrete (SCC) using recycled aggregates (RA) from the precast industry. The results of the fresh-state and mechanical properties tests performed on six concrete mixes (using RA from the precast industry) were presented. The first concrete mix is a reference mix using natural aggregates only (100% NA), and the remaining five mixes had various contents of fine (FRA) and coarse (CRA) recycled aggregates in concrete’s composition: (2) 25/25% (25% RA); (3) 50/50% (50% RA); (4) 100/100% (100% RA); (5) 0/100% (100% CRA); (6) 100/0% (100% FRA). The results showed that the high-performance concrete mixes with RA from the precast industry performed worse than the reference mix. However, taking into account all the mechanical properties studied, it can be concluded that RA from precast concrete elements are of very good quality and can be incorporated in the production of high-performance SCC. The potential demonstrated by the combined use of fine and coarse recycled aggregates was also emphasized. This type of work is expected to effectively contribute to raise awareness among the various players in the construction industry, particularly in the precast concrete industry, to the feasibility of using RA in significant quantities (notably coarse aggregates) and to the safety needed to assume structural functions, even for applications where high performance is required.
Impact of Synthesis Parameters of Multi-Walled Carbon Nanotubes on their Thermoelectric Properties
Authors: Kumanek Bogumiła , Stando Grzegorz , Wróbel Paweł S. , Janas Dawid
Published: October 2019

Carbon nanotubes have been intensively researched for many years because of a wide array of promising properties that they have. In this paper, we present the impact of synthesis parameters on thermoelectric properties of nanocarbon material. We conducted a number of syntheses of multi-walled carbon nanotubes (MWCNTs) at different temperatures (800 and 900 °C) using various amounts of catalyst (2%, 5.5%, and 9.6%) to facilitate the process. We also tested the influence of injection rate of precursor and the necessity of material purification on thermoelectric properties of MWCNTs. The electrical conductivity, thermal conductivity, and Seebeck coefficient were measurement for all samples. Based on these parameters, the values of Power Factor and Figure of Merit were calculated. The results show that the most important parameter in the context of thermoelectric properties is purity of employed MWCNTs. To obtain appropriate material for this purpose optimum synthesis temperature and appropriate content of the catalyst must be selected. The study also reveals that post-synthetic purification of nanocarbon is essential to produce an attractive material for thermoelectrics.
Performance of Halloysite-Mg/Al LDH Materials for Aqueous As(V) and Cr(VI) Removal
Authors: Matusik Jakub , Hyla Jakub , Maziarz Paulina , Rybka Karolina , Leiviskä Tiina
Published: October 2019

This research focused on the investigation of layered double hydroxide (LDH)/halloysite materials’ adsorption efficiency and mechanisms in reactions with aqueous As(V) and Cr(VI) in a broad pH range. The materials consisting of Mg/Al LDH and halloysite were synthesized using both direct precipitation and physical mixing methods. The XRD, FTIR, DTA, SEM and XPS methods were used to evaluate the quality of the obtained materials and get insight into removal mechanisms. The XRD, FTIR and DTA confirmed LDH formation and showed the dominating presence of intercalated carbonates in the LDH structure. The SEM of the materials revealed characteristic agglomerates of layered LDH particles deposited on halloysite tubular forms. The raw LDH phases showed high removal efficiency of both As(V) and Cr (VI) for initial pH in the range of 3–7. In the studied concentration range the materials containing 25 wt % of LDH exhibited a removal efficiency very similar to the raw LDH. In particular, the halloysite presence in the materials’ mass had a positive effect in the reactions with As(V), which was removed by chemisorption. At a low pH the LDH component underwent partial dissolution, which lowered the adsorption efficiency. Apart from the anion exchange mechanism at a low pH the Cr(VI) was removed via formation of MgCrO4 with Mg (II) being released from the LDH structure. The XPS spectra for As(V) did not show changes in oxidation state in the reactions. In turn, a partial reduction of Cr(VI) to Cr(III) was observed, especially at a high pH. The use of materials composed of two different minerals is promising due to reduction of costs as well as prevention of adsorbent swelling. This opens the possibility of its use in dynamic adsorption flow through systems.
Transformation Pathway upon Heating of Metastable β Titanium Alloy Ti-15Mo Investigated by Neutron Diffraction
Authors: Zháňal Pavel , Harcuba Petr , Stráský Josef , Šmilauerová Jana , Beran Přemysl , Hansen Thomas C. , Seiner Hanuš , Janeček Miloš
Published: October 2019

A transformation pathway during thermal treatment of metastable β Ti-15Mo alloy was investigated by in situ neutron diffraction. The evolution of individual phases α , β , and ω was investigated during linear heating with two heating rates of 1.9 ∘ C / min and 5 ∘ C / min and during aging at 450 ∘ C . The results showed that with a sufficient heating rate (5 ∘ C / min in this case), the ω phase dissolves before the α phase forms. On the other hand, for the slower heating rate of 1.9 ∘ C / min , a small temperature interval of the coexistence of the α and ω phases was detected. Volume fractions and lattice parameters of all phases were also determined.
Strong Modulations of Optical Reflectance in Tapered Core–Shell Nanowires
Authors: Floris Francesco , Fornasari Lucia , Bellani Vittorio , Marini Andrea , Banfi Francesco , Marabelli Franco , Beltram Fabio , Ercolani Daniele , Battiato Sergio , Sorba Lucia , Rossella Francesco
Published: October 2019

Random assemblies of vertically aligned core–shell GaAs–AlGaAs nanowires displayed an optical response dominated by strong oscillations of the reflected light as a function of the incident angle. In particular, angle-resolved specular reflectance measurements showed the occurrence of periodic modulations in the polarization-resolved spectra of reflected light for a surprisingly wide range of incident angles. Numerical simulations allowed for identifying the geometrical features of the core–shell nanowires leading to the observed oscillatory effects in terms of core and shell thickness as well as the tapering of the nanostructure. The present results indicate that randomly displaced ensembles of nanoscale heterostructures made of III–V semiconductors can operate as optical metamirrors, with potential for sensing applications.
The Energy Storage Properties of Refrigerants (R170, R134a, R143a, and R152a) in Mof-5 Nanoparticles: A Molecular Simulation Approach
Authors: Wang Qiang , Huang Zhengyong , Ou Shucheng , Zhang Ruiqiang
Published: October 2019

The thermophysical properties of refrigerant can be modified via adding solid materials to it. In this paper, molecular simulations and thermodynamic calculations were employed to investigate the adsorption and energy storage of ethane (R170), 1,1,1,2-tetrafluoroethane (R134a), 1,1,1-trifluoroethane (R143a), and 1,1-difluoroethane (R152a) in metal organic framework (MOF)-5 nanoparticles. The results show that the fluorine atom in the refrigerants will strengthen the adsorption of refrigerants in MOF-5. However, the fluorine-free refrigerant, R170, owns larger enthalpy difference of desorption than the other refrigerants with fluorine under high pressure. The thermal energy storage capacity of the refrigerant/MOF-5 mixture is larger than that of the pure refrigerant at low pressure. Also, the negative enhancement of the energy storage property of the mixture is found in some cases when the refrigerant experiences phase transition.
Features of the Microstructure and Chemical Compositions of Vanadium-Containing Slags Including Determination of Vanadium Oxidation Degrees
Authors: Kovalev Anatoly , Wainstein Dmitry , Vakhrushev Vladimir , Volkov Anton , Kologrieva Ulyana
Published: October 2019

Metallurgical vanadium-containing converter slag could be used as an alternative vanadium source. The development of a physico-chemical basis for the comprehensive processing of industrial vanadium-containing debris requires information about their elemental composition as well as the oxidation degrees of the elements and forms of compounds in order to solve two key problems: a better utilization of industrial wastes and a lowering of environment impact. This research was aimed at the development of methods to determine the fractions of elements and their oxidation degrees in vanadium-containing industrial debris exemplified by basic oxygen converter vanadium slags. A set of bulk and surface analysis methods (X-ray fluorescence analysis (XRF), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS)) was used for this purpose: based on results of elemental analysis, SEM detects the oxide phases of metals, while an analysis of the XPS lines’ fine structures provides fractions of corresponding elements with definite oxidation degrees. In this way, one can determine the fractions of vanadium in multiple oxidation degrees in slags and can properly select the chemicals and parameters of chemical processes for its fullest extraction.
Bioselectivity Induced by Chirality of New Terpenyl Organoselenium Compounds
Authors: Obieziurska Magdalena , Pacuła Agata J. , Długosz-Pokorska Angelika , Krzemiński Marek , Janecka Anna , Ścianowski Jacek
Published: October 2019

A series of new chiral benzisoselenazol-3(2H)-ones substituted on the nitrogen atom with three monoterpene moieties—p-menthane, pinane and carane—was synthesized. The compounds were obtained by the reaction of 2-(chloroseleno)benzoyl chloride with an appropriate terpene amine, first synthesized by a multistep methodology starting from the corresponding alcohol (p-menthane system) or alkene (pinene and carene systems). Compounds were tested as antioxidants and anticancer agents. The N-isopinocampheyl-1,2-benzisoselenazol-3(2H)-one was the best peroxide scavenger and antiproliferative agent on the human promyelocytic leukemia cell line HL-60. The N-menthyl-1,2-benzisoselenazol-3(2H)-one revealed the highest anticancer potential towards breast cancer line MCF-7. The influence of structure and chirality on the bio-activity of the obtained organoselenium compounds was thoroughly evaluated.
Synthesis and Characterization of New Layered Double Hydroxide-Polyolefin Film Nanocomposites with Special Optical Properties
Authors: Monzó Fuensanta , Caparrós Ana , Pérez-Pérez Diego , Arribas Alejandro , Pamies Ramón
Published: October 2019

In this study, we have synthesized new double layered hydroxides to be incorporated to low density polyethylene thermoplastic matrix. These new composites present promising applications as materials to build greenhouses due to the enhancement of their optical properties. A characterization of the modified nanoclay has been performed by means of X-ray fluorescence (XRF), X-ray Diffraction (XRD), Thermogravimetric analysis (TGA), and Fourier-transform infrared spectroscopy (FTIR). We have prepared a series of polyolefin-based films to evaluate the effect of the addition of a whitening agent (disodium 2,2′-((1,1′-biphenyl)-4,4′-diyldivinylene)bis(benzenesulfonate)), the modified hydrotalcite-like material and a commercial dispersant. The rheological and mechanical characterization of the films have proved that the inclusion of the modified-layered double hydroxides (LDHs) do not substantially affect the processing and mechanical performance of the material. On the other hand, optical properties of the nanocomposites are improved by reducing the transmission in the UVA region.
Spent Coffee Grounds in the Production of Lightweight Clay Ceramic Aggregates in View of Urban and Agricultural Sustainable Development
Authors: Andreola Fernanda , Borghi Alessandro , Pedrazzi Simone , Allesina Giulio , Tartarini Paolo , Lancellotti Isabella , Barbieri Luisa
Published: October 2019

This paper presents an innovative application for spent coffee grounds (SCGs) used as filler for the formulation of lightweight clay ceramic aggregates (LWA). LWA can be used for urban and agricultural purposes as a sustainable solution. Spent coffee grounds were tested as a pore forming agent partially acting as a replacement for red clay in material formulation before firing. Substitutions of 10, 15, and 20 wt.% of red clay were tested. The properties of lightweight aggregates with 15 wt.% of SCGs were improved using a specifically tailored fertilizer glass due to its low pH and conductivity within the soil tolerance range. Packaging glassy sand, cattle-bone flour ash, and potassium carbonate were mixed and melted in order to obtain this glass, which when added to the clayey batch functionalized the aggregates by phosphorus and potassium nutrients. The results (in particular, porosity and bulk density) show that the lightweight aggregates obtained have interesting properties for possible uses both in urban (e.g., green roofs as a drainage layer) and agricultural purposes. Moreover, pH and conductivity are in line with the Italian Standard regarding soil amendment (D.lgs. 75/2010). In addition, several leaching tests were performed in a solution containing 2 vol.% citric acid (C6H8O7) to evaluate the release capacity not only of nutrients (P and K) but also to check the presence and release of heavy metals, such as lead (Pb), that may come from the glassy precursor. The results obtained showed that nutrients are efficiently released in 21 days (P = 87.73% and K = 25.74% of released percentage) and Pb release is under the standard threshold of 30 ppm.
Magnetic Nanoparticles of Zinc/Calcium Ferrite Decorated with Silver for Photodegradation of Dyes
Authors: Fernandes Ricardo J. C. , Magalhães Carlos A. B. , Amorim Carlos O. , Amaral Vítor S. , Almeida Bernardo G. , Castanheira Elisabete M. S. , Coutinho Paulo J. G.
Published: October 2019

Magnetic nanoparticles of zinc/calcium ferrite and decorated with silver were prepared by coprecipitation method. The obtained nanoparticles were characterized by UV/Visible absorption, XRD, TEM and SQUID. The mixed zinc/calcium ferrites exhibit an optical band gap of 1.78 eV. HR-TEM imaging showed rectangular nanoplate shapes with sizes of 10 ± 3 nm and aspect ratio mainly between 1 and 1.5. Magnetic measurements indicated a superparamagnetic behavior. XRD diffractograms allowed a size estimation of 4 nm, which was associated with the nanoplate thickness. The silver-decorated zinc/calcium ferrite nanoparticles were successfully employed in the photodegradation of a model dye (Rhodamine B) and industrial textile dyes (CI Reactive Red 195, CI Reactive Blue 250 and CI Reactive Yellow 145). The nanosystems developed exhibited promising results for industrial application in effluent photoremediation using visible light, with the possibility of magnetic recovery.
The Effect of Shear Deformation on Permeability of 2.5D Woven Preform
Authors: Chen Zhiming , Pan Shidong , Zhou Zhengong , Lei Tao , Dong Baofeng , Xu Peifei
Published: October 2019

The accurate prediction of the permeability is the key to optimizing the molding process of fiber reinforced composites, thus to improve the composite quality, and reduce the material and labor costs in the manufacturing process. In this paper, the permeability of 2.5D woven preform with shear deformation was studied by experiments and numerical simulations. The permeabilities of the samples under various shear angles were measured by the radial flow method. An RVE (representative volume element) model based on the fabric microstructure and shear deformation is developed to predict the permeability of preform and the simulation results are compared with experiments value to verify the effectiveness of this model. Using this model, the effect of the fiber volume fraction on the permeability of the 2.5D woven preform was determined. Based on the structural characteristics, experimental and simulation results of the 2.5D woven preform, an empirical equation for predicting its permeability under shear deformation was formulated. The prediction accuracy of the equation was evaluated, and the equation was used to determine the change of permeability with shear deformation for the 2.5D woven preform.
A Semi-Markov Leaky Integrate-and-Fire Model
Authors: Ascione Giacomo , Toaldo Bruno
Published: October 2019

In this paper, a Leaky Integrate-and-Fire (LIF) model for the membrane potential of a neuron is considered, in case the potential process is a semi-Markov process. Semi-Markov property is obtained here by means of the time-change of a Gauss-Markov process. This model has some merits, including heavy-tailed distribution of the waiting times between spikes. This and other properties of the process, such as the mean, variance and autocovariance, are discussed.
Lemnalol Modulates the Electrophysiological Characteristics and Calcium Homeostasis of Atrial Myocytes
Authors: Tai Buh-Yuan , Wen Zhi-Hong , Cheng Pao-Yun , Yang Hsiang-Yu , Duh Chang-Yih , Chen Ping-Nan , Hsu Chih-Hsueng
Published: October 2019

Sepsis, an inflammatory response to infection provoked by lipopolysaccharide (LPS), is associated with high mortality, as well as ischemic stroke and new-onset atrial arrhythmia. Severe bacterial infections causing sepsis always result in profound physiological changes, including fever, hypotension, arrhythmia, necrosis of tissue, systemic multi-organ dysfunction and finally death. LPS challenge-induced inflammatory responses during sepsis may increase the likelihood of the arrhythmogenesis. Lemnalol is known to possess potent anti-inflammatory effects. This study examined whether Lemnalol (0.1 μM) could modulate the electrophysiological characteristics and calcium homeostasis of atrial myocytes under the influence of LPS (1μg/mL). Under challenge with LPS, Lemnalol-treated LA myocytes, had a longer AP duration at 20%, 50% and 90% repolarization of the amplitude, compared to the LPS-treated cells. LPS-challenged LA myocytes showed increased late sodium current, Na+-Ca2+ exchanger current, transient outward current, rapid component of delayed rectifier potassium current, tumor necrosis factor-α, NF-κB and increased phosphorylation of ryanodine receptor (RyR), but a lower L-type Ca2+ current than the control LA myocytes. Exposure to Lemnalol reversed the LPS-induced effects. The LPS-treated and control groups of LA myocytes, with or without the existence of Lemnalol. showed no apparent alterations in the sodium current amplitude or Cav1.2 expression. The expression of sarcoendoplasmic reticulum calcium transport ATPase (SERCA2) was reduced by LPS treatment, while Lemnalol ameliorated the LPS-induced alterations. The phosphorylation of RyR was enhanced by LPS treatment, while Lemnalol attenuated the LPS-induced alterations. In conclusion, Lemnalol modulates LPS-induced alterations of LA calcium homeostasis and blocks the NF-κB pathways, which may contribute to the attenuation of LPS-induced arrhythmogenesis.
Echinochrome A Reduces Colitis in Mice and Induces In Vitro Generation of Regulatory Immune Cells
Authors: Oh Su-Jeong , Seo Yoojin , Ahn Ji-Su , Shin Ye Young , Yang Ji Won , Kim Hyoung Kyu , Han Jin , Mishchenko Natalia P. , Fedoreyev Sergey A. , Stonik Valentin A. , Kim Hyung-Sik
Published: October 2019

Echinochrome A (Ech A), a natural pigment extracted from sea urchins, is the active ingredient of a marine-derived pharmaceutical called ‘histochrome’. Since it exhibits several biological activities including anti-oxidative and anti-inflammatory effects, it has been applied to the management of cardiac injury and ocular degenerative disorders in Russia and its protective role has been studied for other pathologic conditions. In the present study, we sought to investigate the therapeutic potential of Ech A for inflammatory bowel disease (IBD) using a murine model of experimental colitis. We found that intravenous injection of Ech A significantly prevented body weight loss and subsequent lethality in colitis-induced mice. Interestingly, T cell proliferation was significantly inhibited upon Ech A treatment in vitro. During the helper T (Th) cell differentiation process, Ech A stimulated the generation regulatory T (Treg) cells that modulate the inflammatory response and immune homeostasis. Moreover, Ech A treatment suppressed the in vitro activation of pro-inflammatory M1 type macrophages, while inducing the production of M2 type macrophages that promote the resolution of inflammation and initiate tissue repair. Based on these results, we suggest that Ech A could provide a beneficial impact on IBD by correcting the imbalance in the intestinal immune system.
Usefulness of Protocolized Point-of-Care Ultrasonography for Patients with Acute Renal Colic Who Visited Emergency Department: A Randomized Controlled Study
Authors: Kim Seok Goo , Jo Ik Joon , Kim Taerim , Hwang Sung Yeon , Park Joo Hyun , Shin Tae Gun , Sim Min Seob , Cha Won Chul , Yoon Hee
Published: October 2019

Background and Objectives: Ultrasonography is useful in evaluating patients with renal colic and it has high sensitivity and specificity for diagnosing ureter stones by revealing hydronephrosis. We evaluated the efficacy of point-of-care ultrasonography protocol in managing patients with acute renal colic who visited the emergency department (ED). Materials and Methods: Between March 2019 and July 2019, patients who visited the ED because of renal colic were randomly assigned by date of visit either to the conventional group (CG), who underwent routine diagnostic work-up without ultrasonography, or to the ultrasonography group (UG), who underwent bedside ultrasonography as an initial diagnostic testing. When hydronephrosis was detected in the UG group, a confirmatory non-contrast abdomen computed tomography scan was promptly performed. The ED length of stay, complications, and missed or delayed high-risk diagnosis were evaluated. Results: In total, 128 of 147 analyzed patients were confirmed to have ureter stones. The ED length of stay was significantly lower in the UG group than in the CG group (mean 172 min; 95% confidence interval (CI): 151–194 min vs. mean 234 min; 95% CI: 216–252 min). The medical cost was also remarkably lower in the UG group than in the CG group (259 USD vs. 319 USD; p < 0.001). The incidence of complications within 30 days after visiting ED and missed or delayed high-risk diagnosis were not significantly different between the two groups. Conclusions: We found that protocolized point-of-care ultrasonography in patients with acute renal colic who visited the ED can more effectively reduce the length of stay and medical cost without 30-day complication than usual clinical practice.
Serum Asymmetric Dimethylarginine Levels in Patients with Vasovagal Syncope
Authors: Atıcı Adem , Aciksari Gonul , Baycan Omer Faruk , Barman Hasan Ali , Sonsöz Mehmet Rasih , Sahin Mustafa , Asoglu Ramazan , Demirkıran Ahmet , Kul Şeref , Gungor Baris , Durmaz Eser , Bilge Ahmet Kaya , Sahin Irfan
Published: October 2019

Background and Objectives: Vasovagal syncope (VVS) is the most common cause of syncope and has multiple pathophysiological mechanisms. Asymmetric dimethylarginine (ADMA) is the major inhibitor of nitric oxide (NO). In this study, we aimed to investigate the relationship between plasma ADMA levels and syncope during the head-up tilt (HUT) test. Materials and Methods: Overall, 97 patients were included in this study. They were above 18 years of age and were admitted to our clinic with the complaint of at least one episode of syncope consistent with VVS. The HUT test was performed in all patients. Patients were divided into the following two groups based on the HUT test results: group 1 included 57 patients with a positive HUT test and group 2 included 35 patients with a negative HUT test. Blood samples were taken before and immediately after the HUT test to measure ADMA levels. Results: No significant intergroup differences were observed concerning gender and age (female gender 68% vs 60%; mean age 24.85 ± 4.01 vs 25.62 ± 3.54 years, respectively, for groups 1 and 2). ADMA values were similar between groups 1 and 2 before the HUT test [ADMA of 958 (544–1418) vs 951 (519–1269); p = 0.794]. In the negative HUT group, no significant differences were observed in ADMA levels before and after the HUT test [ADMA of 951 (519–1269) vs 951 (519–1566); p = 0.764]. However, in the positive HUT group, ADMA levels were significantly decreased following the HUT test [pretest ADMA of 958 (544–1418) vs post-test ADMA of 115 (67–198); p < 0.001]. Conclusion: ADMA levels significantly decreased after the HUT test in patients with VVS.
Dose Intensive Rituximab and High-Dose Methylprednisolone in Elderly or Unfit Patients with Relapsed Chronic Lymphocytic Leukemia
Authors: Pileckyte Regina , Valceckiene Vilma , Stoskus Mindaugas , Matuzeviciene Reda , Sejoniene Jurgita , Zvirblis Tadas , Griskevicius Laimonas
Published: October 2019

Background and Objectives: BTK and BCL2 inhibitors have changed the treatment paradigms of high-risk and elderly patients with chronic lymphocytic leukemia (CLL), but their long-term efficacy and toxicity are still unknown and the costs are considerable. Our previous data showed that Rituximab (Rtx) and high-dose methylprednisolone (HDMP) can be an effective and safe treatment option for relapsed high-risk CLL patients. Materials and Methods: We explored the efficacy and safety of a higher Rtx dose in combination with a shorter (3-day) schedule of HDMP in relapsed elderly or unfit CLL patients. Results: Twenty-five patients were included in the phase-two, single-arm trial. The median progression free survival (PFS) was 11 months (range 10–12). Median OS was 68 (range 47–89) months. Adverse events (AE) were mainly grade I–II° (77%) and no deaths occurred during the treatment period. Conclusions: 3-day HDMP and Rtx was associated with clinically meaningful improvement in most patients. The median PFS in 3-day and 5-day HDMP studies was similar and the toxicity of the 3-day HDMP schedule proved to be lower. The HDMP and Rtx combination can still be applied in some relapsed high-risk and elderly or unfit CLL patients if new targeted therapies are contraindicated or unavailable. (ClinicalTrials.gov identifier: NCT01576588).
Antioxidant Capacity of Preterm Neonates Assessed by Hydrogen Donor Value
Authors: Matyas Melinda , Hasmasanu Monica G. , Zaharie Gabriela
Published: October 2019

Background and objectives: Premature newborns have a number of oxidative stress-inducing disorders. Antioxidant defense is deficient in premature newborns. Hydrogen donors can be used to evaluate the non-enzymatic antioxidant defense. By measuring hydrogen donors, a group of antioxidants can be assessed: tocopherol, ascorbic acid, and glutathione. These represent the most relevant group of non-enzymatic antioxidants. The main aim of this study was to evaluate the non-enzymatic antioxidant defense capacity of premature newborns by measuring hydrogen donors. Materials and Methods: We evaluated the non-enzymatic antioxidant capacity by hydrogen donor measurement in 24 premature newborns with various oxidative stress-inducing disorders and in 14 premature newborns without oxidative stress-inducing conditions. Statistical analysis was performed using the Statistica program (v. 8, StatSoft, Round Rock, TX, USA). Differences between groups were tested with Wilcoxon matched test for quantitative paired data or Mann–Whitney test for quantitative independent data. The Z test for proportions was used to compare qualitative data among subgroups. Results: Hydrogen donors in the study group had a significantly lower value on the first day of life compared to the value of the control group. Also, the hydrogen donor value in the study group was significantly lower on the first day compared to the third day of life (p < 0.05). Neonates with mild respiratory distress (14 cases) had increased hydrogen donor values on their third day of life compared to the first day of life. Conclusions: The antioxidant capacity is influenced by oxidative stress-inducing disorders. Respiratory distress influenced the hydrogen donor value and antioxidant defense. Antioxidant defense gradually improves after birth according to gestational age.
Treatment with Statins in Elderly Patients
Authors: Horodinschi Ruxandra-Nicoleta , Stanescu Ana Maria Alexandra , Bratu Ovidiu Gabriel , Pantea Stoian Anca , Radavoi Daniel George , Diaconu Camelia Cristina
Published: October 2019

Elderly patients are a special category of patients, due to the physiological changes induced by age, the great number of comorbidities and drug treatment and last, but not least, to the cognitive dysfunction frequently encountered in this population. Cardiovascular disease is the most important cause of morbidity and mortality in elderly individuals worldwide. The rate of cardiovascular events increases after 65 years in men and after 75 years in women. Myocardial infarction and stroke are the leading disorders caused by atherosclerosis, that lead to death or functional incapacity. Elderly people have a greater risk to develop atherosclerotic cardiovascular disease. The incidence and prevalence of atherosclerosis increase with age and the number of cardiovascular events is higher in elderly patients. The most efficient treatment against atherosclerosis is the treatment with statins, that has been shown to decrease the risk both of stroke and coronary artery disease in all age groups. The advantages of the treatment become evident after at least one year of treatment. Primary prevention is the most important way of preventing cardiovascular disease in elderly individuals, by promoting a healthy lifestyle and reducing the risk factors. Secondary prevention after a stroke or myocardial infarction includes mandatory a statin, to diminish the risk of a recurrent cardiovascular event. The possible side effects of statin therapy are diabetes mellitus, myopathy, and rhabdomyolysis, hepatotoxicity. The side effects of the treatment are more likely to occur in elderly patients, due to their multiple associated comorbidities and drugs that may interact with statins. In elderly people, the benefits and disadvantages of the treatment with statins should be put in balance, especially in those receiving high doses of statins.
Intratumoral Cytotoxic T-Lymphocyte Density and PD-L1 Expression Are Prognostic Biomarkers for Patients with Colorectal Cancer
Authors: Calik Ilknur , Calik Muhammet , Turken Gulistan , Ozercan Ibrahim Hanifi , Dagli Adile Ferda , Artas Gokhan , Sarikaya Burcu
Published: October 2019

Background and objectives: Cytotoxic T-lymphocyte (CTL)-mediated inflammatory response to tumors plays a crucial role in preventing the progression of some cancers. Programmed cell death ligand 1 (PD-L1), a cell-surface glycoprotein, has been reported to repress T-cell-mediated immune responses against tumors. However, the clinical significance of PD-L1 in colorectal cancer (CRC) remains unclear. Our aim was to elucidate the prognostic significance of PD-L1 expression and CD8+ CTL density in CRC. Materials and methods: CD8 and PD-L1 immunostaining was conducted on 157 pathologic specimens from patients with CRC. The CD8+ CTL density and PD-L1 expression within the tumor microenvironment were assessed by immunohistochemistry. Results: Tumor invasion (pT) was significantly correlated with intratumoral (p = 0.011) and peritumoral (p = 0.016) CD8+ CTLs density in the tumor microenvironment. In addition, there was a significant difference in the intensity of CD8+ CTLs between patients with and without distant metastases (intratumoral p = 0.007; peritumoral p = 0.037, T-test). Lymph node metastasis (pN) and TNM stage were significantly correlated with PD-L1 expression in CRC cells (p = 0.015, p = 0.029, respectively). Multivariate analysis revealed a statistically significant relationship between the intratumoral CD8+ CTL density and disease-free survival (DFS) (hazard ratio [HR] 2.06; 95% confidence interval [CI]: 1.01–4.23; p = 0.043). The DFS was considerably shorter in patients with a high expression of PD-L1 in cancer cells than those with a low expression (univariate HR 2.55; 95% CI 1.50–4.34; p = 0.001; multivariate HR 0.48; 95% CI 0.28–0.82; p = 0.007). Conversely, patients with high PD-L1 expression in tumor-infiltrating lymphocytes had a longer DFS in both univariate analysis (HR 0.25; 95% CI: 0.14–0.44; p < 0.001) and multivariate analysis (HR 3.42; 95% CI: 1.95–6.01; p < 0.001). Conclusion: The CD8+ CTL density and PD-L1 expression are prognostic biomarkers for the survival of patients with CRC.