bluuebunny/crossref_metadata_2025 huggingface dataset:
Corrosion Resistance of Mild Steel Coated with Orgainc Material Containing Pyrazol Moiety
Authors: El Hajjaji Fadoua , Abrigach Farid , Hamed Othman , Hasan Abdelfatah Rasem , Taleb Mustapha , Jodeh Shehdeh , Rodríguez-Castellón Enrique , Martínez de Yuso María del Valle , Algarra Manuel
Published: September 2018

Pyridine (P1) and benzoic acid (P2) derivatives with pyrazole moieties were synthesized and evaluated as corrosion inhibitors for mild steel in acidic medium. The evaluation was performed by electrochemical impedance spectroscopy (EIS), potentiodynamic polarization, and weight loss measurement. The surface morphologies of the control and steel samples coated with the pyrazole derivatives P1 and P2 were examined by the scanning electron microscopy (SEM), UV-Vis, and X-ray photoelectron spectrocopy (XPS) spectroscopies. Results revealed minor changes on steel surfaces before and after immersion in a 1 M HCl solution. Both derivatives, P1 and P2, showed good inhibition efficiency that is dependent on inhibitor concentration. Both P1 and P2 act as mixed-type inhibitors. The benzoic acid derivative (P2) showed a higher efficiency than P1, which could be attributed to the carboxyl group that is located at the para position to the amino group. This induces a direct electronic resonance between the two groups, the amino and the carboxyl. As a result of this, a higher electron density on the carboxyl group and a stronger bonding to the metal surface occurred. Results also show that, the bonding of both pyrazoles on mild steel surface obey Langmuir adsorption isotherm. Quantum chemical calculations were performed to theoretically define the relationship between the molecular structures and inhibition efficiencies of P1 and P2.
Destructive Effect of Water Vapour on an In Situ Diffusion Barrier Layer within an Aluminide Coating on IN738 Alloy
Authors: Li Chao , Song Peng , Chen Kunlun , He Xuan , Yu Xiao , Lu Jiansheng
Published: September 2018

High-temperature interdiffusion within a hot-dipped aluminide (Al-10 wt.% Si) coating on an IN738 superalloy was investigated at 1050 °C in air and in air plus water vapour. The resulting morphology of in situ diffusion barrier layer (DBL) within the aluminide coating is affected by oxidizing atmospheres; DBL can effectively retard the interdiffusion of aluminium within the coating. The location of the in situ DBL is governed by the partial pressure of oxygen at different depths from the oxide scales in both atmospheres. Meanwhile, the diffusion fluxes of different elements led to DBLs with different morphologies in the aluminide coating on the Ni-based alloy.
Comparison of the Mesomorphic Behaviour of 1:1 and 1:2 Mixtures of Charged Gay-Berne GB(4.4,20.0,1,1) and Lennard-Jones Particles
Authors: Margola Tommaso , Satoh Katsuhiko , Saielli Giacomo
Published: September 2018

We present a Molecular Dynamics study of mixtures of charged Gay-Berne (GB) ellipsoids and spherical Lennard-Jones (LJ) particles as models of ionic liquids and ionic liquid crystals. The GB system is highly anisotropic (GB(4.4,20.0,1,1)) and we observe a rich mesomorphism, with ionic nematic and smectic phases in addition to the isotropic mixed phase and crystalline phases with honeycomb structure. The systems have been investigated by analyzing the orientational and translational order parameters, as well as radial distribution functions. We have directly compared 1:1 mixtures, where the GB and LJ particles have a charge equal in magnitude and opposite in sign, and 1:2 mixtures where the number of LJ particles is twice as large compared to the GB and their charge half in magnitude. The results highlight the role of the long-range isotropic electrostatic interaction compared to the short-range van der Waals anisotropic contribution, and the effect of the stoichiometry on the stability of ionic mesophases.
A Virtual Resource for Enhancing the Spatial Comprehension of Crystal Lattices
Authors: Vergara Diego , Rubio Manuel Pablo , Lorenzo Miguel
Published: September 2018

Students commonly exhibit serious spatial comprehension difficulties when they come to learning crystal systems. To solve this problem, an active methodology based on the use of a Didactic Virtual Tool (DVT)—developed by the authors—is presented in this paper. The students’ opinion was obtained from a survey carried out on 40 mechanical engineering students. The analysis of the obtained results reveals that, by using this DVT, students achieve a better understanding of the contents where spatial difficulties often arise during conventional teaching. Several DVT features were highly valued by the students, e.g., didactic use was rated 9.5 out of 10 and the methodology using the DVT in the classroom was rated 8.5 out of 10. In addition, the results revealed two factors that the students considered essential for using a DVT, both related to the tool design: (i) the modern aspect, i.e., it is necessary to keep a DVT updated to avoid obsolescence; and (ii) the DVT must be appealing in order to attract the students’ attention.
Education and Religion in Secular Age from an African Perspective
Authors: Isaak Paul John
Published: September 2018

In this article the author shall argue that before Namibian independence in 1990, Christianity was used by some as a weapon of breaking down, or as a tool of, colonialism, racism, and apartheid. In the name of a religious god unashamed acts of violence and wars were committed and resulted in genocide of 1904 to 1908. However, such brutalities did not conquer the African spirit of what is identified in this article as the Ubuntu (humaneness). Inspired by their sense of Ubuntu the Africans, in the face of German colonialism and the South African imposed Apartheid system, finally emerged victorious and accepted the model of religious pluralism, diversity, and the principle of African Ubuntu. We shall, furthermore, argue that the Namibian educational system and the Namibian Constitution, Articles 1 and 21, the Republic of Namibia is established as a secular state wherein all persons shall have the right to freedom to practise any religion and to manifest such practice. It means religious diversity and pluralism is a value, a cultural or religious or political ideology, which positively welcomes the encounter of religions. It is often characterized as an attitude of openness in a secular state towards different religions and interreligious dialogue and interfaith programs. As an example we shall focus on the subject of Religious and Moral Education where such religious diversity and pluralism are directly linked to political, social, and economic issues, as well as moral values.
CFD Steady Model Applied to a Biomass Boiler Operating in Air Enrichment Conditions
Authors: Gómez Miguel , Martín Rubén , Collazo Joaquín , Porteiro Jacobo
Published: September 2018

A numerical model is proposed to perform CFD simulations of biomass boilers working in different operating conditions and analyse the results with low computational effort. The model is based on steady fluxes that represent the biomass thermal conversion stages through the conservation of mass, energy, and chemical species in the packed bed region. The conversion reactions are combined with heat and mass transfer submodels that release the combustion products to the gas flow. The gas flow is calculated through classical finite volume techniques to model the transport and reaction phenomena. The overall process is calculated in a steady state with a fast, efficient, and reasonably accurate method, which allows the results to converge without long computation times. The modelling is applied to the simulation of a 30 kW domestic boiler, and the results are compared with experimental tests with reasonably good results for such a simple model. The model is also applied to study the effect of air enrichment in boiler performance and gas emissions. The boiler operation is simulated using different oxygen concentrations that range from 21% to 90% in the feeding air, and parameters such as the heat transferred, fume temperatures, and emissions of CO, CO2, and NOx are analysed. The results show that with a moderated air enrichment of 40% oxygen, the energy performance can be increased by 8%, CO emissions are noticeably reduced, and NOx remains practically stable.
An Integer Linear Programming Model to Select and Temporally Allocate Resources for Fighting Forest Fires
Authors: Rodríguez-Veiga Jorge , Ginzo-Villamayor María José , Casas-Méndez Balbina
Published: September 2018

Optimal planning of the amount and type of resources needed for extinguishing a forest fire is a task that has been addressed in the literature, using models obtained from operational research. In this study, a general integer linear programming model is proposed, which addresses the allocation of resources in different time periods during the planning period for extinguishing a fire, and with the goal of meeting Spanish regulations for the non-negligence of fronts and periods of rest for pilots and brigades. A computer program and interface were developed using the R language. By means of an example using historical data, we illustrate the model at work and its exact resolution. Then, we carry out a simulation study to analyze the obtained objective functions and resolution times. Our simulation study shows that an exact solution can be obtained very quickly without requiring heuristic algorithms, provided that the planning period does not exceed five hours.
Understanding Dispersion of Revolver-Type Anti-Resonant Hollow Core Fibers
Authors: Zeisberger Matthias , Hartung Alexander , Schmidt Markus
Published: September 2018

Here, we analyze the dispersion behavior of revolver-type anti-resonant hollow core fibers, revealing that the chromatic dispersion of this type of fiber geometry is dominated by the resonances of the glass annuluses, whereas the actual arrangement of the anti-resonant microstructure has a minor impact. Based on these findings, we show that the dispersion behavior of the fundamental core mode can be approximated by that of a tube-type fiber, allowing us to derive analytic expressions for phase index, group-velocity dispersion and zero-dispersion wavelength. The resulting equations and simulations reveal that the emergence of zero group velocity dispersion in anti-resonant fibers is fundamentally associated with the adjacent annulus resonance which can be adjusted mainly via the glass thickness of the anti-resonant elements. Due to their generality and the straightforward applicability, our findings will find application in all fields addressing controlling and engineering of pulse dispersion in anti-resonant hollow core fibers.
Does Implicit Bias Predict Dictator Giving?
Authors: Lee Daniel J.
Published: September 2018

Implicit associations and biases are carried without awareness or conscious direction, yet there is reason to believe they may be influenced by social pressures. In this paper, I study social pressure as a motive to give, as well as giving itself under conditions of implicit bias. In doing so, I pair the Implicit Association Test (IAT), commonplace in other social sciences, with a laboratory dictator game with sorting. I find that despite its popularity, the IAT does not predict dictator giving and social pressure does not explain acts of giving from biased dictators. These results are indicative of the meaningful difference between having an implicit bias and acting on one. As such, results can be thought of as a bound on the external validity of the IAT.
Metabolic Effects of Metformin in the Failing Heart
Authors: Dziubak Aleksandra , Wójcicka Grażyna , Wojtak Andrzej , Bełtowski Jerzy
Published: September 2018

Accumulating evidence shows that metformin is an insulin-sensitizing antidiabetic drug widely used in the treatment of type 2 diabetes mellitus (T2DM), which can exert favorable effects on cardiovascular risk and may be safely used in patients with heart failure (HF), and even able to reduce the incidence of HF and to reduce HF mortality. In failing hearts, metformin improves myocardial energy metabolic status through the activation of AMP (adenosine monophosphate)-activated protein kinase (AMPK) and the regulation of lipid and glucose metabolism. By increasing nitric oxide (NO) bioavailability, limiting interstitial fibrosis, reducing the deposition of advanced glycation end-products (AGEs), and inhibiting myocardial cell apoptosis metformin reduces cardiac remodeling and hypertrophy, and thereby preserves left ventricular systolic and diastolic functions. While a lot of preclinical and clinical studies showed the cardiovascular safety of metformin therapy in diabetic patients and HF, to confirm observed benefits, the specific large-scale trials configured for HF development in diabetic patients as a primary endpoints are necessary.
Structure Prediction of Rare Earth Doped BaO and MgO Containing Aluminosilicate Glasses–the Model Case of Gd2O3
Authors: Zekri Mohamed , Erlebach Andreas , Herrmann Andreas , Damak Kamel , Rüssel Christian , Sierka Marek , Maâlej Ramzi
Published: September 2018

The medium-range atomic structure of magnesium and barium aluminosilicate glasses doped with Gd2O3 as a model rare earth oxide is elucidated using molecular dynamics simulations. Our structure models rationalize the strong dependence of the luminescence properties of the glasses on their chemical composition. The simulation procedure used samples’ atomic configurations, the so-called inherent structures, characterizing configurations of the liquid state slightly above the glass transition temperature. This yields medium-range atomic structures of network former and modifier ions in good agreement with structure predictions using standard simulated annealing procedures. However, the generation of a large set of inherent structures allows a statistical sampling of the medium-range order of Gd3+ ions with less computational effort compared to the simulated annealing approach. It is found that the number of Si-bound non-bridging oxygen in the vicinity of Gd3+ considerably increases with growing ionic radius and concentration of network-modifier ions. In addition, structure predictions indicate a low driving force for clustering of Gd3+, yet no precise correlation between the atomic structure and luminescence lifetimes can be conclusively established. However, the structure models provided in this study can serve as a starting point for future quantum mechanical simulations to shed a light on the relation between the atomic structure and optical properties of rare earth doped aluminosilicate glasses.
Magnetic and Mössbauer Spectroscopy Studies of Zinc-Substituted Cobalt Ferrites Prepared by the Sol-Gel Method
Authors: Lin Qing , Xu Jianmei , Yang Fang , Lin Jinpei , Yang Hu , He Yun
Published: September 2018

Zinc ion-substituted cobalt ferrite powders Co1−xZnxFe2O4 (x = 0–0.7) were prepared by the sol-gel auto-combustion process. The structural properties and magnetic of the samples were investigated with X-ray diffraction (XRD), superconducting quantum interference device, and a Mössbauer spectrometer. The results of XRD showed that the powder of a single cubic phase of ferrites calcined when kept at 800 °C for 3 h. The lattice constant increases with increase in Zn concentration, but average crystallite size does not decrease constantly by increasing the zinc content, which is related to pH value. It was confirmed that the transition from ferrimagnetic to superparamagnetic behaviour depends on increasing zinc concentration by Mössbauer spectra at room temperature. Magnetization at room temperature increases for x ≤ 0.3, but decreases for increasing Zn2+ ions. The magnetization of Co0.7Zn0.3Fe2O4 reached maximum value (83.51 emu/g). The coercivity decreased with Zn2+ ions, which were doped on account of the decrease of the anisotropy constant.
Unraveling Nanoscale Magnetic Ordering in Fe3O4 Nanoparticle Assemblies via X-rays
Authors: Chesnel Karine , Griner Dalton , Smith Dallin , Cai Yanping , Trevino Matea , Newbold Brittni , Wang Tianhan , Liu Tianmin , Jal Emmanuelle , Reid Alex H. , Harrison Roger G.
Published: September 2018

Understanding the correlations between magnetic nanoparticles is important for nanotechnologies, such as high-density magnetic recording and biomedical applications, where functionalized magnetic particles are used as contrast agents and for drug delivery. The ability to control the magnetic state of individual particles depends on the good knowledge of the magnetic correlations between particles when assembled. Inaccessible via standard magnetometry techniques, nanoscale magnetic ordering in self-assemblies of Fe3O4 nanoparticles is here unveiled via X-ray resonant magnetic scattering (XRMS). Measured throughout the magnetization process, the XRMS signal reveals size-dependent inter-particle magnetic correlations. Smaller (5 nm) particles show little magnetic correlations, even when packed close together, yielding to magnetic disorder in the absence of an external field, i.e., superparamagnetism. In contrast, larger (11 nm) particles tend to be more strongly correlated, yielding a mix of magnetic orders including ferromagnetic and anti-ferromagnetic orders. These magnetic correlations are present even when the particles are sparsely distributed.
Low-Dose Naltrexone (LDN)—Review of Therapeutic Utilization
Authors: Toljan Karlo , Vrooman Bruce
Published: September 2018

Naltrexone and naloxone are classical opioid antagonists. In substantially lower than standard doses, they exert different pharmacodynamics. Low-dose naltrexone (LDN), considered in a daily dose of 1 to 5 mg, has been shown to reduce glial inflammatory response by modulating Toll-like receptor 4 signaling in addition to systemically upregulating endogenous opioid signaling by transient opioid-receptor blockade. Clinical reports of LDN have demonstrated possible benefits in diseases such as fibromyalgia, Crohn’s disease, multiple sclerosis, complex-regional pain syndrome, Hailey-Hailey disease, and cancer. In a dosing range at less than 1 μg per day, oral naltrexone or intravenous naloxone potentiate opioid analgesia by acting on filamin A, a scaffolding protein involved in μ-opioid receptor signaling. This dose is termed ultra low-dose naltrexone/naloxone (ULDN). It has been of use in postoperative control of analgesia by reducing the need for the total amount of opioids following surgery, as well as ameliorating certain side-effects of opioid-related treatment. A dosing range between 1 μg and 1 mg comprises very low-dose naltrexone (VLDN), which has primarily been used as an experimental adjunct treatment for boosting tolerability of opioid-weaning methadone taper. In general, all of the low-dose features regarding naltrexone and naloxone have been only recently and still scarcely scientifically evaluated. This review aims to present an overview of the current knowledge on these topics and summarize the key findings published in peer-review sources. The existing potential of LDN, VLDN, and ULDN for various areas of biomedicine has still not been thoroughly and comprehensively addressed.
Heat Treatment Optimization in Al-Cu-Mg-Si Alloys, with or without Prior Deformation
Authors: Alvarez-Antolin Jose Florentino , Segurado-Frutos Elvira , Neira-Castaño Hilario , Asensio-Lozano Juan
Published: September 2018

The properties of Al-Cu-Mg alloys simultaneously depend on dissolving the maximum amount of Cu and Mg in the solution treatment and on achieving optimal ageing. The aim of this study is to analyze the effect on an Al-Cu4.5-Mg1.5-Si0.75 alloy, manufactured by continuous casting and hot rolling until achieving a reduction in its cross-section greater than 90%, of the dwell time at the solution temperature, 495 °C (4, 8, and 24 h), of the different ageing temperatures (160, 180, and 200 °C), and of cold rolling prior to ageing. The microstructural variations underwent the material during its manufacturing process, form its continuous casting to subsequent hot rolling, were analyzed by means of optical microscopy (OM) and scanning electronic microscopy (SEM), with characteristic energy dispersive X-ray (EDX) microanalysis. The crystalline phases present after the different solution and natural ageing treatments were identified and quantified by means of X-ray diffraction (XRD), concluding that Mg is easier to dissolve than Cu. The transient states associated with the Mg2Si phase are the most abundant. However, the longer the dwell time at the solution temperature, the greater the weight percentage of the transient states associated with the Al2Cu phase during ageing. The higher the ageing temperature, the faster the peak hardness is reached, but the lower its value. The ageing temperature that allows the highest hardness to be obtained was 160 °C. The maximum hardness value reached was 162 HV, obtained after a solution treatment at 495 °C for 4 h and ageing at 160 °C for 50 h. By means of prior cold rolling, the peak hardness values are reached more quickly and their values slightly exceed those obtained without this deformation. With ageing at 180 °C, 168 HV are reached after 6 h at this temperature.
Metabolomics Approach for Validation of Self-Reported Ibuprofen and Acetaminophen Use
Authors: Dennis Kristine K. , Carter Brian D. , Gapstur Susan M. , Stevens Victoria L.
Published: September 2018

Over-the-counter analgesic use is common and is typically assessed through self-report; therefore, it is subject to misclassification. Detection of drug metabolites in biofluids offers a viable tool for validating self-reported analgesic use. Thus, the aim of this study was to determine the utility of a metabolomics approach for the validation of acetaminophen and ibuprofen use in blood samples. Untargeted mass spectrometry-based metabolomics analysis was conducted in serum samples from 1547 women and plasma samples from 556 men. The presence of two metabolites each for acetaminophen and ibuprofen at levels at or above a defined cutoff value was used to determine concordance with self-reported use. For acetaminophen use based on the presence of both acetaminophen and acetamidophenylglucuronide, concordance was 98.5–100% among individuals reporting use today, and 79.8–91.4% for those reporting never or rare use. Ibuprofen use based on the presence of both carboxyibuprofen and hydroxyibuprofen resulted in concordance of 51.3–52.5% for individuals reporting use today and 99.4–100% for those reporting never or rare use. Our findings suggest that an untargeted metabolomics approach in blood samples may be useful for validating self-reported acetaminophen use. However, this approach appears unlikely to be suitable for validating ibuprofen use.
Amorphous Silicon Carbide Platform for Next Generation Penetrating Neural Interface Designs
Authors: Deku Felix , Frewin Christopher L. , Stiller Allison , Cohen Yarden , Aqeel Saher , Joshi-Imre Alexandra , Black Bryan , Gardner Timothy J. , Pancrazio Joseph J. , Cogan Stuart F.
Published: September 2018

Microelectrode arrays that consistently and reliably record and stimulate neural activity under conditions of chronic implantation have so far eluded the neural interface community due to failures attributed to both biotic and abiotic mechanisms. Arrays with transverse dimensions of 10 µm or below are thought to minimize the inflammatory response; however, the reduction of implant thickness also decreases buckling thresholds for materials with low Young’s modulus. While these issues have been overcome using stiffer, thicker materials as transport shuttles during implantation, the acute damage from the use of shuttles may generate many other biotic complications. Amorphous silicon carbide (a-SiC) provides excellent electrical insulation and a large Young’s modulus, allowing the fabrication of ultrasmall arrays with increased resistance to buckling. Prototype a-SiC intracortical implants were fabricated containing 8 - 16 single shanks which had critical thicknesses of either 4 µm or 6 µm. The 6 µm thick a-SiC shanks could penetrate rat cortex without an insertion aid. Single unit recordings from SIROF-coated arrays implanted without any structural support are presented. This work demonstrates that a-SiC can provide an excellent mechanical platform for devices that penetrate cortical tissue while maintaining a critical thickness less than 10 µm.
Enhancement of Virus Infection Using Dynamic Cell Culture in a Microchannel
Authors: Kim Jeong A , Choi Hye Jin , Kim Chul Min , Jin Hee Kyung , Bae Jae-sung , Kim Gyu Man
Published: September 2018

With increasing interest in induced pluripotent stem cells (iPSCs) in the field of stem cell research, highly efficient infection of somatic cells with virus factors is gaining importance. This paper presents a method of employing microfluidic devices for dynamic cell culture and virus infection in a microchannel. The closed space in the microchannel provided a better environment for viruses to diffuse and contact cell surfaces to infect cells. The microfluidic devices were fabricated by photolithography and soft lithography. NIH/3T3 fibroblast cells were cultured in the microfluidic device in static and dynamic conditions and compared with the conventional culture method of using Petri dishes. Virus infection was evaluated using an enhanced green fluorescent protein virus as a model. Dynamic culture in the microchannel showed similar growth of cells to that in Petri dish culture, but the virus infection efficiency was four-times higher. The proposed dynamic culture system could be useful in iPSC research by providing efficient virus infection tools.
Genotype-Environment Interaction Shapes the Microbial Assemblage in Grapevine’s Phyllosphere and Carposphere: An NGS Approach
Authors: Singh Prashant , Santoni Sylvain , This Patrice , Péros Jean-Pierre
Published: September 2018

Plant surface or phyllosphere is the habitat of hyperdiverse microbial communities and it is always exposed to the fluctuating environmental factors, which is thought to be one of the potential drivers of microbial community structuring. Impact of grapevine genotypes in variable environmental factors (i.e., at different geographic locations) on the phyllosphere has never been studied and is the main objective of this report. Using high throughput short amplicon sequencing of 16S rRNA genes and internal transcribed spacer (ITS), we analyzed the impacts of genotypes of Vitis Vinifera (coming from three genetic pool), on the microbial (bacterial and fungal) assemblage in the phyllosphere. First, we performed the analysis of the phyllosphere microbiome while using fifteen genotypes that were chosen to maximize intra-specific diversity and grown in two Mediterranean vineyards. Then, the same analysis was performed on five commercially important varieties of Vitis vinifera that were sampled from three different French agro-climatic zones (or terroir: a combination of climate, soils, and human practices). Our study revealed that, at a particular geographic location, genotypes have an impact on microbial assemblage in the phyllosphere and carposphere of leaf and fruit (or berries), respectively, which is more prominent on the carposphere but the effect of terroir was much stronger than the genotype when the leaf phyllosphere of five grapevine varieties grown in different agro-climatic zones was compared. Impacts of the season and exterior plant organs (leaf and berries) on microbial taxa structuring in the phyllosphere was also assessed and presented in this report.
Authigenic Mg-Clay Minerals Formation in Lake Margin Deposits (the Cerro de los Batallones, Madrid Basin, Spain)
Authors: Herranz Juan Emilio , Pozo Manuel
Published: September 2018

The Madrid Basin contains large and well developed deposits of Mg-clays of Miocene age. These were developed in an environment controlled by a lacustrine saline-alkaline environment with an arid or semi-arid climate, leading to large deposits of Mg-clays. This paper summarizes the study about the formation of Mg-clay minerals in the transition from mudflat lithofacies made-up of Mg-smectite to palustrine lithofacies where sepiolite is predominant. The samples collected in the field were characterized by XRD (X-Ray Diffaction) (bulk sample and clay fraction), examined using SEM (Scanning Electron Microscopy) and analyzed by XRF (X-Ray Fluorescence) and FTIR (Fourier Transform Infrared Spectroscopy). The results suggest that during the formation of these materials dissolution-precipitation, direct precipitation and recrystallization mechanisms intervened. The type of water present (runoff, lake and/or groundwater) is a key factor for the development of the different mineral phases. In the case of the study, the analyzed series goes from mudflat conditions with influence of runoff water to a palustrine environment. During this evolution, the influence of groundwater increases with time. This is reflected in the affinity between the samples analyzed and the presence of certain elements that could serve as indicators of changes between different media.
A Study on the Flocculation and Sedimentation of Iron Tailings Slurry Based on the Regulating Behavior of Fe3+
Authors: Yue Tao , Wu Xiqing , Chen Xiao , Liu Tianyu
Published: September 2018

Based on the regulating behavior of Fe3+, flocculation and sedimentation tests of iron tailings slurry flocculated using 2 mg/L anionic polyacrylamide (APAM) were studied, including the tests of Fe3+ dosage, regulating time, and pH. Flocculation–sedimentation tests showed that: a recommended addition of 56 mg/L Fe3+ produced a surprisingly bad flocculation effect; sedimentation ability decreased with the increase of regulating time, however, the regulating ability during the first 1 min was low; Fe3+ displayed a high regulating effect at pH 6–7, and then decreased with the increase of slurry pH. Size analysis demonstrated that the regulating ability of Fe3+ was related to the change of floc size, which increased with the decrease of size. Zeta potential analysis and calculation showed that small concentrations of Fe3+ and certain hydroxyl complex ions (such as Fe(OH)2+ and Fe(OH)2+) adsorbed onto the APAM molecular chains, resulting in a decreased charge density of the APAM molecules, and this electrostatic adsorption was able to make the polymer curl more easily. Fourier Transform Infrared Spectroscopic (FTIR) indicated the APAM on the hematite was slightly degraded into a monomer-like short-chain polymer while adding certain concentration of Fe3+. Scanning Electron Microscope (SEM) imaging showed that the network structure of APAM molecules treated by Fe3+ collapsed, and the APAM adsorption amount on hematite was significantly reduced. Therefore, the effect of Fe3+ on the APAM could be recommended as a new method for desorption and degradation of the APAM contained in the tailings slurry or flocs.
Daphnauranins C–E, Three New Antifeedants from Daphne aurantiaca Roots
Authors: Huang Sheng Zhuo , Ma Qing Yun , Wang Qi , Dai Hao Fu , Liu Yu Qing , Zhou Jun , Zhao You Xing
Published: September 2018

Daphnauranins C–E (compounds 1–3), two sesquiterpenoids and one monoterpenoid were isolated from the roots of Daphne aurantiaca Diels. Daphnauranin C is a 9-O-13 etherified and hydroperoxy-substituted guaiane sesquiterpenoid, daphnauranin D is a guaiane sesquiterpenoid ketal, and daphnauranin E is a monoterpenoid lactone. Their structures were elucidated by comprehensive analyses of MS, 1D NMR, and 2D NMR spectroscopic data. In an anti-feeding activities test, daphnauranins C–E showed activity against male fruit fly with anti-feeding indexes (AI) up to 39.1, 39.2, and 27.8% respectively, at 1 mM.
Electrospun Poly(ethylene-co-vinyl alcohol)/Graphene Nanoplatelets Composites of Interest in Intelligent Food Packaging Applications
Authors: Torres-Giner Sergio , Echegoyen Yolanda , Teruel-Juanes Roberto , Badia Jose D. , Ribes-Greus Amparo , Lagaron Jose M.
Published: September 2018

Graphene nanoplatelets (GNPs) were synthetized from graphite powder and, thereafter, embedded in poly(ethylene-co-vinyl alcohol) (EVOH) fibers by electrospinning in the 0.1–2 wt.-% range. The morphological, chemical, and thermal characterization performed on the electrospun nanocomposite fibers mats revealed that the GNPs were efficiently dispersed and rolled along the EVOH fibrilar matrix up to contents of 0.5 wt.-%. Additionally, the dielectric behavior of the nanocomposite fibers was evaluated as a function of the frequency range and GNPs content. The obtained results indicated that their dielectric constant rapidly decreased with the frequency increase and only increased at low GNPs loadings while the nanocomposite fiber mats became electrically conductive, with the maximum at 0.5 wt.-% GNPs content. Finally, the electrospun mats were subjected to a thermal post-treatment and dark films with a high contact transparency were obtained, suggesting that the nanocomposites can be used either in a nonwoven fibers form or in a continuous film form. This study demonstrates the potential of electrospinning as a promising technology to produce GNPs-containing materials with high electrical conductivity that can be of potential interest in intelligent packaging applications as “smart” labels or tags.
Preliminary Study of Ultrasonic Welding as a Joining Process for Electrospun Nanofiber Mats
Authors: Wirth Emilia , Sabantina Lilia , Weber Marcus O. , Finsterbusch Karin , Ehrmann Andrea
Published: September 2018

Electrospinning can be used to create nanofiber mats for diverse applications, from wound dressings and tissue engineering to filters for medical and biotechnological applications. In most of these applications, it is necessary to fix the nanofiber mat on a macroscopic textile fabric, on another nanofiber mat or within a frame to keep it at the desired position. Due to their extremely low thickness and areal mass, however, nanofiber mats are easily destroyed by sewing, and in several situations glued bonds are too thick and not flexible enough. Here we report on ultrasonic welding of polyacrylonitrile nanofiber mats, suggesting this method as a joining process without destruction of the mat morphology for thermoplastic nanofiber mats. A variety of welding patterns results in different adhesion forces between both joined nanofiber mats and different failure mechanisms, with some welding patterns enabling bonding stronger than the mats themselves. Our findings show that ultrasonic welding is a possible joining method for polyacrylonitrile nanofiber mats.
Anti-Candidal Activity and In Vitro Cytotoxicity Assessment of Graphene Nanoplatelets Decorated with Zinc Oxide Nanorods
Authors: Ficociello Graziella , De Caris Maria Giovanna , Trillò Giusy , Cavallini Domenico , Sarto Maria Sabrina , Uccelletti Daniela , Mancini Patrizia
Published: September 2018

Candida albicans is the most common pathogenic fungus that is isolated in nosocomial infections in medically and immune-compromised patients. The ability of C. albicans to convert its form from yeast to hyphal morphology contributes to biofilm development that effectively shelters Candida against the action of antifungals molecules. In the last years, nanocomposites are the most promising solutions against drug-resistant microorganisms. The aim of this study was to investigate the antifungal activity of graphene nanoplateles decorated with zinc oxide nanorods (ZNGs) against the human pathogen Candida albicans. We observed that ZNGs were able to induce a significant mortality in fungal cells, as well as to affect the main virulence factors of this fungus or rather the hyphal development and biofilm formation. Reactive Oxygen Species (ROS) formation in yeast cells resulted one of the mechanisms of ZNGs to induce mortality. Finally, the toxicity of this nanomaterial was tested also on human keratinocyte cell line HaCaT. Our data indicated that ZNGs resulted not toxic when their aggregation state decreased by adding glycerol as emulsifier to ZNGs suspensions or when HaCaT cells were grown on ZNGs-coated glasses. Overall, the results that were obtained indicated that ZNGs could be exploited as an antifungal nanomaterial with a high degree of biocompatibility on human cells.
Effect of Chlorogenic Acids on Cognitive Function: A Randomized, Double-Blind, Placebo-Controlled Trial
Authors: Saitou Katsuyoshi , Ochiai Ryuji , Kozuma Kazuya , Sato Hirotaka , Koikeda Takashi , Osaki Noriko , Katsuragi Yoshihisa
Published: September 2018

(1) Background: Chlorogenic acids (CGAs) have been attracting interest of late, owing to their health benefits. Here, we performed a randomized, double-blind, placebo-controlled trial to investigate whether CGAs improved cognitive function in humans. (2) Methods: Thirty-eight healthy participants were assigned to either the CGA group, which was given CGA-added beverage daily for 16 weeks, or the placebo group. Cognitive functions were assessed using the Japanese version of the CNS Vital Signs (Cognitrax). (3) Results: The CGA group showed significant increase in the Cognitrax domain scores for motor speed, psychomotor speed, and executive function compared with the placebo group, as well as an improvement in the shifting attention test scores. In blood analysis, the CGA group showed increased levels of apolipoprotein A1 and transthyretin, both of which are putative biomarkers for early-stage cognitive decline. (4) Conclusions: These results suggest that CGAs may improve some cognitive functions, which would help in the efficient performance of complex tasks.
An 8-Week, Low Carbohydrate, High Fat, Ketogenic Diet Enhanced Exhaustive Exercise Capacity in Mice Part 2: Effect on Fatigue Recovery, Post-Exercise Biomarkers and Anti-Oxidation Capacity
Authors: Huang Qingyi , Ma Sihui , Tominaga Takaki , Suzuki Katsuhiko , Liu Chunhong
Published: September 2018

A low-carbohydrate, high-fat ketogenic diet (KD) is a nutritional approach ensuring that the body utilizes lipids. In our previous study, we found that an eight-week ketogenic high-fat, low-carbohydrate diet increased the capacity of endurance exercise in mice without aggravated muscle injury, despite the decrease of absolute muscle volume. The potential mechanism is most possibly to be enhanced capacity to mobilize and utilize fat. In the present study, we investigated whether a ketogenic diet influences post-exercise recovery by measuring blood biomarkers, muscle and liver oxidative state as well as fatigue recovery 24 h post exercise by employing an open-field locomotion test. Several biochemistry markers indicating exercise-induced injury after exhaustive exercise were improved by KD, followed by a 24-h rest with free feed access, including lactate. No aggravated hepatic oxidative damage was observed, whereas muscular oxidative stress was increased by KD. Accelerated recovery induced by exhaustive exercise was also observed from blood biomarkers of injury. For fatigue recovery, lactate concentration, a marker often employed as exhaustion index was lowered by KD, whereas an open field test showed that KD application contributed to increased locomotion after exhaustive exercise, followed by a 24-h rest. These results suggest that KD has the potential to be used as a fatigue-preventing and/or recovery-promoting diet approach in endurance athletes.
Review of the Clinical Experiences of Feeding Infants Formula Containing the Human Milk Oligosaccharide 2′-Fucosyllactose
Authors: Reverri Elizabeth J. , Devitt Amy A. , Kajzer Janice A. , Baggs Geraldine E. , Borschel Marlene W.
Published: September 2018

Human milk oligosaccharides (HMOs) are the third most abundant solid component in human milk after lactose and lipids. Preclinical research has demonstrated that HMOs and specifically 2′-fucosyllactose (2′-FL) are more than a prebiotic and have multiple functions, including immune, gut, and cognition benefits. Previously, human milk has been the only source for significant levels of HMOs. The most abundant HMO in most mothers’ breast milk is 2′-FL. Recently, 2′-FL has been synthesized and shown to be structurally identical to the 2′-FL found in human milk. 2′-FL HMO is now available in some commercial infant formulas. The purpose of this narrative review was to summarize the clinical experiences of feeding infant formula supplemented with the HMO, 2′-FL. Most of these studies investigated standard intact milk protein-based infant formulas containing 2′-FL, and one evaluated a partially hydrolyzed whey-based formula. Collectively, these clinical experiences demonstrated that 2′-FL being added to infant formula was safe, well-tolerated, and absorbed and excreted with similar efficiency to 2′-FL in human milk. Further, infants that were fed formula with 2′-FL had immune benefits, fewer parent-reported respiratory infections, and improved symptoms of formula intolerance. Ultimately, infant formula with 2′-FL supports immune and gut health and is closer compositionally and functionally to human milk.
Assessment of General Public’s Knowledge and Opinions towards Antibiotic Use and Bacterial Resistance: A Cross-Sectional Study in an Urban Setting, Rufisque, Senegal
Authors: Bassoum Oumar , Sougou Ndèye Marème , Diongue Mayassine , Lèye Mamadou Makhtar Mbacke , Mbodji Mouhamad , Fall Djibril , Seck Ibrahima , Faye Adama , Tal-Dia Anta
Published: September 2018

Background: Bacterial resistance is a major public health problem worldwide. One solution to this scourge is to sensitize the general public on rational use of antibiotics. Our goal was to assess people’s knowledge and opinions about antibiotic use and bacterial resistance in an urban setting. Method: We performed a cross-sectional study. A convenience sampling was done. A questionnaire was administered to 400 persons during face-to-face interviews. Results: Most respondents thought that antibiotics are effective against colds/flu (69.8%), cough (72.3%) and sore throat (64.4%). At the same time, 42.8% stated that antibiotic therapy can be stopped as soon as the symptoms disappear. Only 8.8% and 41.8% of people knew that handwashing and vaccination prevented bacterial resistance. Globally, 7% of people had a good knowledge. Socio-demographic variables were not associated with the level of knowledge. The main sources of information were entourage and pharmacy staff. Regarding the opinions, 78.3% of surveyed participants the people thought that that people overuse antibiotics. Additionally, 28% said that they have no role to play against bacterial resistance. Conclusion: People living in an urban setting had a low knowledge about antibiotic use and bacterial resistance. There is a need to implement awareness campaigns. Further studies on population practices toward antibiotic use are necessary.
Fibrin Hydrogels for Endothelialized Liver Tissue Engineering with a Predesigned Vascular Network
Authors: Wang Xiaohong , Liu Chang
Published: September 2018

The design and manufacture of a branched vascular network is essential for bioartificial organ implantation, which provides nutrients and removes metabolites for multi-cellular tissues. In the present study, we present a technology to manufacture endothelialized liver tissues using a fibrin hydrogel and a rotational combined mold. Both hepatocytes and adipose-derived stem cells (ADSCs) encapsulated in a fibrin hydrogel were assembled into a spindle construct with a predesigned multi-branched vascular network. An external overcoat of poly(dl-lactic-co-glycolic acid) was used to increase the mechanical properties of the construct as well as to act as an impervious and isolating membrane around the construct. Cell survivability reached 100% in the construct after 6 days of in vitro culture. ADSCs in the spindle construct were engaged into endothelial cells/tissues using a cocktail growth factor engagement approach. Mechanical property comparison and permeability evaluation tests all indicated that this was a viable complex organ containing more than two heterogeneous tissue types and a functional vascular network. It is, therefore, the first time an implantable bioartificial liver, i.e., endothelialized liver tissue, along with a hierarchical vascular network, has been created.
Preparation and Characterization of DOPO-ITA Modified Ethyl Cellulose and Its Application in Phenolic Foams
Authors: Ma Yufeng , Gong Xuanang , Liao Chuhao , Geng Xiang , Wang Chunpeng , Chu Fuxiang
Published: September 2018

In order to improve the performance of phenolic foam, an additive compound of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) and Itaconic acid (ITA) were attached on the backbone of ethyl cellulose (EC) and obtained DOPO-ITA modified EC (DIMEC), which was used to modify phenolic resin and composite phenolic foams (CPFs). The structures of DOPO-ITA were verified by Fourier transform infrared spectroscopy (FT-IR) and nuclear magnetic resonance (1H NMR). The molecular structure and microstructure were characterized by FT-IR spectra and SEM, respectively. Compared with EC, the crystallinity of DIMEC was dramatically decreased, and the diffraction peak positions were basically unchanged. Additionally, thermal stability was decreased and Ti decreased by 24 °C. The residual carbon (600 °C) was increased by 25.7%. With the dosage of DIMEC/P increased, the Ea values of DIMEC composite phenolic resins were increased gradually. The reaction orders were all non-integers. Compared with PF, the mechanical properties, flame retardancy, and the residual carbon (800 °C) of CPFs were increased. The cell size of CPFs was less and the cell distribution was relatively regular. By comprehensive analysis, the suitable dosage of DIMEC/P was no more than 15%.
Ten Steps Qualitative Modelling: Development and Validation of Conceptual Institutional-Social-Ecological Model of Public Open Space (POS) Governance and Quality
Authors: Ling Gabriel Hoh Teck , Leng Pau Chung
Published: September 2018

Compared to the literature on quantitative and statistical modelling, there is a lack of research on qualitative environmental-related modelling, which focuses on a conceptual-theory-based model. Therefore, this paper attempts to formulate a qualitative institutional-social-ecological model, by showcasing how the 10 steps modelling is relevant and is applied to the institutional-property-rights model of neighbourhood residential commons. Using an instance from one case study (i.e., Sabah, Malaysia), a conceptual problem-solution model describing local property-rights system tragedies of public open space (POS) governance and quality, and the emergence of self-governing collective action was demonstrated. Methodologically, the modelling procedures were specified as a 10-step process, starting with setting the objectives of the model and concluding with the validation of suitability and usefulness of the model. The validation was conducted using the experts’ opinion, via the semi-structured interviews with five public officials. With slight necessary amendments, the model was proven practical, useful, flexible, reliable and valid in serving its purposes in understanding and predicting the effects of local property-rights system tragedies on POS commons dilemmas, and the subsequent emergence and necessity of a self-governing solution. This local model provides policy insights to the local public officials, which facilitate their institutional-social-ecological decision-making process that helps improve local POS governance and quality.