bluuebunny/crossref_metadata_2025 huggingface dataset:
Mosaicity of Spin-Crossover Crystals
Authors: Lakhloufi Sabine , Tailleur Elodie , Guo Wenbin , Le Gac Frédéric , Marchivie Mathieu , Lemée-Cailleau Marie-Hélène , Chastanet Guillaume , Guionneau Philippe
Published: September 2018

Real crystals are composed of a mosaic of domains whose misalignment is evaluated by their level of “mosaicity” using X-ray diffraction. In thermo-induced spin-crossover compounds, the crystal may be seen as a mixture of metal centres, some being in the high-spin (HS) state and others in the low spin (LS) state. Since the volume of HS and LS crystal packings are known to be very different, the assembly of domains within the crystal, i.e., its mosaicity, may be modified at the spin crossover. With little data available in the literature we propose an investigation into the temperature dependence of mosaicity in certain spin-crossover crystals. The study was preceded by the examination of instrumental factors, in order to establish a protocol for the measurement of mosaicity. The results show that crystal mosaicity appears to be strongly modified by thermal spin-crossover; however, the nature of the changes are probably sample dependent and driven, or masked, in most cases by the characteristics of the crystal (disorder, morphology …). No general relationship could be established between mosaicity and crystal properties. If, however, mosaicity studies in spin-crossover crystals are conducted and interpreted with great care, they could help to elucidate crucial crystal characteristics such as mechanical fatigability, and more generally to investigate systems where phase transition is associated with large volume changes.
Research on Recognition Method of Driving Fatigue State Based on Sample Entropy and Kernel Principal Component Analysis
Authors: Ye Beige , Qiu Taorong , Bai Xiaoming , Liu Ping
Published: September 2018

In view of the nonlinear characteristics of electroencephalography (EEG) signals collected in the driving fatigue state recognition research and the issue that the recognition accuracy of the driving fatigue state recognition method based on EEG is still unsatisfactory, this paper proposes a driving fatigue recognition method based on sample entropy (SE) and kernel principal component analysis (KPCA), which combines the advantage of the high recognition accuracy of sample entropy and the advantages of KPCA in dimensionality reduction for nonlinear principal components and the strong non-linear processing capability. By using support vector machine (SVM) classifier, the proposed method (called SE_KPCA) is tested on the EEG data, and compared with those based on fuzzy entropy (FE), combination entropy (CE), three kinds of entropies including SE, FE and CE that merged with KPCA. Experiment results show that the method is effective.
Full-Speed Range Encoderless Control for Salient-Pole PMSM with a Novel Full-Order SMO
Authors: Wang Yuanlin , Wang Xiaocan , Xie Wei , Dou Manfeng
Published: September 2018

For salient-pole permanent magnet synchronous motor (PMSM), the amplitude of extended back electromotive force (EEMF) is determined by rotor speed, stator current and its derivative value. Theoretically, even at extremely low speed, the back EEMF can be detected if the current in q-axis is changing. However, it is difficult to detect the EEMF precisely due to the current at low speed. In this paper, novel full-order multi-input and multi-output discrete-time sliding mode observer (SMO) is built to detect the rotor position. With the proposed rotor position estimation technique, the motor can start up from standstill and reverse between positive and negative directions without a position sensor. The proposed method was evaluated by experiment.
A Stochastic Approach to Energy Policy and Management: A Case Study of the Pakistan Energy Crisis
Authors: Sajid Zaman , Javaid Asma
Published: September 2018

The energy policy of a country dictates its ability to better manage and deal with an energy crisis. A sustainable energy policy deals with not only energy production but also with energy consumption. In the past, the government of Pakistan has lacked such an approach. This study aims to develop a policy-making framework to improve the energy management of Pakistan through a probabilistic approach. Stochastic analysis is performed in this study and the uncertainty in energy data is used to propose a holistic energy policy. Energy-utilization data from 17 different sources are used to compare the accuracy of energy-consumption data from 1989 to 2013. The analysis reveals that there exists an uncertainty in energy-consumption data and the major cause of this uncertainty is energy theft. The analysis shows that the industry has the highest uncertainty in its energy-data utilization, followed by the transport and the domestic sectors of Pakistan. Based on stochastic analysis, seven recommended energy-policy guidelines are presented to manage the energy crisis in the country. The analysis proposes that Pakistan needs to take measures to control energy theft.
Cycas micronesica Trees Alter Local Soil Traits
Authors: Marler Thomas E. , Krishnapillai Murukesan V.
Published: September 2018

Cycad plants possess uncommon morphological, chemical, and ontogenetic characteristics and they may introduce localized changes in soil traits that increase habitat heterogeneity. We used mature Cycas micronesica K.D. Hill trees growing in a range of soil types in Guam, Rota, and Yap to quantify differences between the soils beneath target trees and paired non-target soils away from cycad trees. The chronic presence of a C. micronesica tree introduced numerous localized changes in soil traits, increasing the heterogeneity of elemental stoichiometry in the community. Nitrogen, carbon:phosphorus, and nitrogen:phosphorus were increased in target soils among every soil type. Carbon increased and phosphorus decreased in most target soils. The habitats revealing the greatest number of elements with differences between target and non-target soils were the habitats with acid soils. The greatest number of metals exhibiting differences between the target and non-target soils occurred in the impoverished sandy habitat. This is the first report that indicates a cycad tree increases community spatial heterogeneity by localized changes in soil chemistry. Contemporary declines in cycad populations due to anthropogenic threats inadvertently decrease this spatial heterogeneity and its influences on primary producers in the landscape then cascading effects on the food web.
Forecasting the Effects of In-Store Marketing on Conversion Rates for Online Shops
Authors: Fink Holger , Graf Yvonne
Published: September 2018

As webstores usually face the issue of low conversion rates, finding ways to effectively increase them is of special interest to researchers and practitioners alike. However, to the best of our knowledge, no one has yet empirically investigated the usefulness of various in-webstore marketing tools like coupons or different types of product recommendations. By analysing clickstream data for a shoe and a bed online store, we are contributing to closing this gap. In particular, we use our present data to build more general hypotheses on how such purchasing incentives might function and on how they could be used in practice.
Correction: Li, X.; et al. Identification and Characterization of the WOX Family Genes in Five Solanaceae Species Reveal Their Conserved Roles in Peptide Signaling. Genes 2018, 9, 260.
Authors: Li Xiaoxu , Hamyat Madiha , Liu Cheng , Ahmad Salman , Gao Xiaoming , Guo Cun , Wang Yuanying , Guo Yongfeng
Published: September 2018

The authors wish to make the following change in their paper [...]
Faithful Families Cooking and Eating Smart and Moving for Health: Evaluation of a Community Driven Intervention
Authors: Torrence Caitlin , Griffin Sarah F. , Rolke Laura , Kenison Kelli , Marvin AltaMae
Published: September 2018

Background: There is an increasing need to adapt and use community interventions to address modifiable behaviors that lead to poor health outcomes, like obesity, diabetes, and heart disease. Poor health outcomes can be tied to community-level factors, such as food deserts and individual behaviors, like sedentary lifestyles, consuming large portion sizes, and eating high-calorie fast food and processed foods. Methods: Through a social ecological approach with family, organization and community, the Faithful Families Cooking and Eating Smart and Moving for Health (FFCESMH) intervention was created to address these concerns in a rural South Carolina community. FFCESMH used gatekeepers to identify 18 churches and four apartment complexes in low-income areas; 176 participants completed both pre- and post-survey measures. Results: Paired t-test measures found statistically significant change in participant perception of food security (0.39, p-value = 0.005, d = 0.22), self-efficacy with physical activity and healthy eating (0.26, p-value = 000, d = 0.36), and cooking confidence (0.17, p-value = 0.01, d = 0.19). There was not significant change in cooking behaviors, as assessed through the Cooking Behaviors Scale. Conclusion: FFCESMH shows that a social ecological approach can be effective at increasing and improving individual healthy behaviors and addressing community-level factors in low-income rural communities.
Contribution of HIV Infection, AIDS, and Antiretroviral Therapy to Exocrine Pathogenesis in Salivary and Lacrimal Glands
Authors: Nizamuddin Imran , Koulen Peter , McArthur Carole P.
Published: September 2018

The structure and function of exocrine glands are negatively affected by human immunodeficiency virus (HIV) infection and its co-morbidities, including innate and adaptive immune responses. At the same time, exocrine function may also be influenced by pharmacotherapies directed at the infectious agents. Here, we briefly review the role of the salivary glands and lacrimal glands in normal physiology and exocrine pathogenesis within the context of HIV infection and acquired immune deficiency syndrome (AIDS), including the contribution of antiretroviral therapies on both. Subsequently, we discuss the impact of HIV infection and the types of antiretroviral therapy on disease management and therapy development efforts.
TPS Genes Silencing Alters Constitutive Indirect and Direct Defense in Tomato
Authors: Coppola Mariangela , Cascone Pasquale , Bossi Simone , Corrado Giandomenico , Garonna Antonio Pietro , Maffei Massimo , Rao Rosa , Guerrieri Emilio
Published: September 2018

Following herbivore attacks, plants modify a blend of volatiles organic compounds (VOCs) released, resulting in the attraction of their antagonists. However, volatiles released constitutively may affect herbivores and natural enemies’ fitness too. In tomato there is still a lack of information on the genetic bases responsible for the constitutive release of VOC involved in direct and indirect defenses. Here we studied the constitutive emissions related to the two most abundant sesquiterpene synthase genes expressed in tomato and their functional role in plant defense. Using an RNA interference approach, we silenced the expression of TPS9 and TPS12 genes and assessed the effect of this transformation on herbivores and parasitoids. We found that silenced plants displayed a different constitutive volatiles emission from controls, resulting in reduced attractiveness for the aphid parasitoid Aphidius ervi and in an impaired development of Spodoptera exigua larvae. We discussed these data considering the transcriptional regulation of key-genes involved in the pathway of VOC metabolism. We provide several lines of evidence on the metabolic flux from terpenoids to phenylpropanoids. Our results shed more light on constitutive defenses mediated by plant volatiles and on the molecular mechanisms involved in their metabolic regulation.
Ambiguous Effects of Autophagy Activation Following Hypoperfusion/Ischemia
Authors: Ferrucci Michela , Biagioni Francesca , Ryskalin Larisa , Limanaqi Fiona , Gambardella Stefano , Frati Alessandro , Fornai Francesco
Published: September 2018

Autophagy primarily works to counteract nutrient deprivation that is strongly engaged during starvation and hypoxia, which happens in hypoperfusion. Nonetheless, autophagy is slightly active even in baseline conditions, when it is useful to remove aged proteins and organelles. This is critical when the mitochondria and/or proteins are damaged by toxic stimuli. In the present review, we discuss to that extent the recruitment of autophagy is beneficial in counteracting brain hypoperfusion or, vice-versa, its overactivity may per se be detrimental for cell survival. While analyzing these opposite effects, it turns out that the autophagy activity is likely not to be simply good or bad for cell survival, but its role varies depending on the timing and amount of autophagy activation. This calls for the need for an appropriate autophagy tuning to guarantee a beneficial effect on cell survival. Therefore, the present article draws a theoretical pattern of autophagy activation, which is hypothesized to define the appropriate timing and intensity, which should mirrors the duration and severity of brain hypoperfusion. The need for a fine tuning of the autophagy activation may explain why confounding outcomes occur when autophagy is studied using a rather simplistic approach.
Effects of Polyphenols on Thermogenesis and Mitochondrial Biogenesis
Authors: Wood dos Santos Tanila , Cristina Pereira Quélita , Teixeira Lucimara , Gambero Alessandra , A. Villena Josep , Lima Ribeiro Marcelo
Published: September 2018

Obesity is a health problem worldwide, and energy imbalance has been pointed out as one of the main factors responsible for its development. As mitochondria are a key element in energy homeostasis, the development of obesity has been strongly associated with mitochondrial imbalance. Polyphenols are the largest group of phytochemicals, widely distributed in the plant kingdom, abundant in fruits and vegetables, and have been classically described as antioxidants owing to their well-established ability to eliminate free radicals and reactive oxygen species (ROS). During the last decade, however, growing evidence reports the ability of polyphenols to perform several important biological activities in addition to their antioxidant activity. Special attention has been given to the ability of polyphenols to modulate mitochondrial processes. Thus, some polyphenols are now recognized as molecules capable of modulating pathways that regulate mitochondrial biogenesis, ATP synthesis, and thermogenesis, among others. The present review reports the main benefits of polyphenols in modulating mitochondrial processes that favor the regulation of energy expenditure and offer benefits in the management of obesity, especially thermogenesis and mitochondrial biogenesis.
The Diagnosis and Clinical Significance of Paragangliomas in Unusual Locations
Authors: Asa Sylvia L. , Ezzat Shereen , Mete Ozgur
Published: September 2018

Paragangliomas are neuroendocrine neoplasms, derived from paraganglia of the sympathetic and parasympathetic nervous systems. They are most commonly identified in the head and neck, being most frequent in the carotid body, followed by jugulotympanic paraganglia, vagal nerve and ganglion nodosum, as well as laryngeal paraganglia. Abdominal sites include the well-known urinary bladder tumors that originate in the Organ of Zuckerkandl. However, other unusual sites of origin include peri-adrenal, para-aortic, inter-aortocaval, and paracaval retroperitoneal sites, as well as tumors in organs where they may not be expected in the differential diagnosis of neuroendocrine neoplasms, such as thyroid, parathyroid, pituitary, gut, pancreas, liver, mesentery, lung, heart and mediastinum. The distinction of these lesions from epithelial neuroendocrine neoplasms is critical for several reasons. Firstly, the determination of clinical and biochemical features is different from that used for epithelial neuroendocrine tumors. Secondly, the genetic implications are different, since paragangliomas/pheochromocytomas have the highest rate of germline susceptibility at almost 40%. Finally, the characterization of metastatic disease is unique in these highly syndromic lesions. In this review, we summarize updated concepts by outlining the spectrum of anatomic locations of paragangliomas, the importance of morphology in establishing the correct diagnosis, the clinical implications for management, and the impact of genetics on the distinction between multifocal primary tumors compared with malignant disease.
Why Real-World Problems Go Unresolved and What We Can Do about It: Inferences from a Limited-Resource Model of Successful Intelligence
Authors: Sternberg Robert J.
Published: September 2018

In this article I suggest why a symposium is desirable on the topic of why, despite worldwide increases in IQ since the beginning of the 20th century, there are so many unresolved and dramatic problems in the world. I briefly discuss what some of these problems are, and the paradox of people with higher IQs not only being unable to solve them, but in some cases people being unwilling to address them. I suggest that higher IQ is not always highly relevant to the problems, and in some cases, may displace other skills that better would apply to the solution of the problems. I present a limited-resource model as an adjunct to the augmented theory of successful intelligence. The model suggests that increasing societal emphases on analytical abilities have displaced development and utilization of other skills, especially creative, practical, and wisdom-based ones, that better could be applied to serious world problems. I also discuss the importance of cognitive inoculation against unscrupulous and sometimes malevolent attempts to change belief systems.
Synthetic and Marine-Derived Porous Scaffolds for Bone Tissue Engineering
Authors: Neto Ana S. , Ferreira José M. F.
Published: September 2018

Bone is a vascularized and connective tissue. The cortical bone is the main part responsible for the support and protection of the remaining systems and organs of the body. The trabecular spongy bone serves as the storage of ions and bone marrow. As a dynamic tissue, bone is in a constant remodelling process to adapt to the mechanical demands and to repair small lesions that may occur. Nevertheless, due to the increased incidence of bone disorders, the need for bone grafts has been growing over the past decades and the development of an ideal bone graft with optimal properties remains a clinical challenge. This review addresses the bone properties (morphology, composition, and their repair and regeneration capacity) and puts the focus on the potential strategies for developing bone repair and regeneration materials. It describes the requirements for designing a suitable scaffold material, types of materials (polymers, ceramics, and composites), and techniques to obtain the porous structures (additive manufacturing techniques like robocasting or derived from marine skeletons) for bone tissue engineering applications. Overall, the main objective of this review is to gather the knowledge on the materials and methods used for the production of scaffolds for bone tissue engineering and to highlight the potential of natural porous structures such as marine skeletons as promising alternative bone graft substitute materials without any further mineralogical changes, or after partial or total transformation into calcium phosphate.
Cell Type Influences Local Delivery of Biomolecules from a Bioinspired Apatite Drug Delivery System
Authors: Alhamdi Jumana , Jacobs Emily , Gronowicz Gloria , Benkirane-Jessel Nadia , Hurley Marja , Kuhn Liisa
Published: September 2018

Recently, the benefit of step-wise sequential delivery of fibroblast growth factor-2 (FGF-2) and bone morphogenetic protein-2 from a bioinspired apatite drug delivery system on mouse calvarial bone repair was demonstrated. The thicknesses of the nanostructured poly-l-Lysine/poly-l-Glutamic acid polyelectrolyte multilayer (PEM) and the bone-like apatite barrier layer that make up the delivery system, were varied. The effects of the structural variations of the coating on the kinetics of cell access to a cytotoxic factor delivered by the layered structure were evaluated. FGF-2 was adsorbed into the outer PEM, and cytotoxic antimycin-A (AntiA) was adsorbed to the substrate below the barrier layer to detect the timing of the cell access. While MC3T3-E1 osteoprogenitor cells accessed AntiA after three days, the RAW 264.7 macrophage access occurred within 4 h, unless the PEM layer was removed, in which case the results were reversed. Pits were created in the coating by the RAW 264.7 macrophages and initiated delivery, while the osteoprogenitor cell access to drugs occurred through a solution-mediated coating dissolution, at junctions between the islands of crystals. Macrophage-mediated degradation is therefore a mechanism that controls drug release from coatings containing bioinspired apatite.
Antimicrobial Features of Organic Functionalized Graphene-Oxide with Selected Amines
Authors: Zarafu Irina , Turcu Ioana , Culiță Daniela C. , Petrescu Simona , Popa Marcela , Chifiriuc Mariana C. , Limban Carmen , Telehoiu Alexandra , Ioniță Petre
Published: September 2018

(1) Background: Graphene oxide is a new carbon-based material that contains functional groups (carboxyl, hydroxyl, carbonyl, epoxy) and therefore can be easily functionalized with organic compounds of interest, yielding hybrid materials with important properties and applications. (2) Methods: Graphene oxide has been obtained by a modified Hummers method and activated by thionyl chloride in order to be covalently functionalized with amines. Thus obtained hybrid materials were characterized by infrared and Raman spectroscopy, elemental analysis and scanning electron microscopy and then tested for their antimicrobial and anti-biofilm activity. (3) Results: Eight amines of interest were used to functionalize grapheme oxide and the materials thus obtained were tested against Gram-negative (Escherichia coli, Pseudomonas aeruginosa) and Gram-positive (Staphylococcus aureus) bacterial strainsin plankonic and biofilm growth state. Both amines, as well as the functionalized materials, exhibited anti-microbial features. Three to five functionalized graphene oxide materials exhibited improved inhibitory activity against planktonic strains as compared with the respective amines. In exchange, the amines alone proved generally more efficient against biofilm-embedded cells. (4) Conclusions: Such hybrid materials may have a wide range of potential use in biomedical applications.
Composition, Structure and Morphology Evolution of Octadecylamine (ODA)–Reduced Graphene Oxide and Its Dispersion Stability under Different Reaction Conditions
Authors: Bao Tianjiao , Wang Zhiyong , Zhao Yan , Wang Yan , Yi Xiaosu
Published: September 2018

Octadecylamine (ODA) can solve the aggregation problem of graphene sheets in the chemical exfoliation method. However, no attempts have been made to investigate the evolution of ODA–reduced graphene oxide (ORGO) with reaction conditions and the modification mechanism, which is the core problem to realize the controllable production and practical application of graphene. In this study, we treated graphene oxide (GO) with ODA under different reaction conditions to prepare ORGO. Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy, atomic force microscopy, Raman spectroscopy, thermogravimetric analysis (TGA), and UV–vis spectrophotometry were employed to analyze the composition, structure, morphology and characteristics of the as–prepared graphene sheets. The results showed that the reduction reaction could occur under mild conditions, but the edge grafting reaction could only be activated by a higher temperature. Moreover, the ORGO created at 80 °C for 5 h and 120 °C for 0.5 h exhibited the optimized properties, both excellent dispersing stability and high heat resisting property, since they had more edge grafting chains and a suitable reduction degree.
Characterization of the Microbial Population Inhabiting a Solar Saltern Pond of the Odiel Marshlands (SW Spain)
Authors: Gómez-Villegas Patricia , Vigara Javier , León Rosa
Published: September 2018

The solar salterns located in the Odiel marshlands, in southwest Spain, are an excellent example of a hypersaline environment inhabited by microbial populations specialized in thriving under conditions of high salinity, which remains poorly explored. Traditional culture-dependent taxonomic studies have usually under-estimated the biodiversity in saline environments due to the difficulties that many of these species have to grow at laboratory conditions. Here we compare two molecular methods to profile the microbial population present in the Odiel saltern hypersaline water ponds (33% salinity). On the one hand, the construction and characterization of two clone PCR amplified-16S rRNA libraries, and on the other, a high throughput 16S rRNA sequencing approach based on the Illumina MiSeq platform. The results reveal that both methods are comparable for the estimation of major genera, although massive sequencing provides more information about the less abundant ones. The obtained data indicate that Salinibacter ruber is the most abundant genus, followed by the archaea genera, Halorubrum and Haloquadratum. However, more than 100 additional species can be detected by Next Generation Sequencing (NGS). In addition, a preliminary study to test the biotechnological applications of this microbial population, based on its ability to produce and excrete haloenzymes, is shown.
A Numerical Study on Co-Extrusion to Produce Coaxial Aluminum-Steel Compounds with Longitudinal Weld Seams
Authors: Behrens Bernd-Arno , Klose Christian , Chugreev Alexander , Heimes Norman , Thürer Susanne Elisabeth , Uhe Johanna
Published: September 2018

The use of lightweight materials is one possibility to limit the weight of vehicles and to reduce CO2 emissions. However, the mechanical properties and weight-saving potential of mono-materials are limited. Material compounds can overcome this challenge by combining the advantages of different materials in one component. Lateral angular co-extrusion (LACE) allows the production of coaxial semi-finished products consisting of aluminum and steel. In this study, a finite element model of the LACE process was built up and validated by experimental investigations. A high degree of agreement between the calculated and experimentally determined forces, temperatures, and the geometrical shape of the hybrid profiles was achieved. In order to determine suitable parameters for further extrusion experiments, the influence of different process parameters on material flow and extrusion force was investigated in a numerical parametric study. Both the temperature and extrusion ratio showed a significant influence on the occurring maximum extrusion force as well as the material flow inside the LACE tool. The maximum force of 2.5 MN of the employed extrusion press was not exceeded. An uneven material flow was observed in the welding chamber, leading to an asymmetric position of the steel rod in the aluminum matrix.
Effects of Small Ni Addition on the Microstructure and Toughness of Coarse-Grained Heat-Affected Zone of High-Strength Low-Alloy Steel
Authors: Huang Gang , Wan Xiangliang , Wu Kaiming , Zhao Huazhong , Misra Raja Devesh Kumarmr
Published: September 2018

The objective of the present study is to investigate the effects of nickel (Ni) on the microstructure and impact toughness of coarse-grained heat-affected zone (CGHAZ) of high-strength low-alloy steel. It was observed that the microstructure of CGHAZ predominantly consisted of bainite and a small proportion of martensite-austenite (M-A) constituents and acicular ferrite (AF). With increased Ni content, the percentage of M-A constituent decreased and AF increased; consequently, the impact toughness of CGHAZ increased. The study revealed that a small addition of nickel significantly affected the formation of M-A constituents and AF; however, no obvious influence was observed on the bainitic microstructure of high-strength low-alloy steel.
Barkhausen Noise Assessment of the Surface Conditions Due to Deep Hole Drilling and Their Influence on the Fatigue Behaviour of AISI 4140
Authors: Baak Nikolas , Schaldach Fabian , Nickel Jan , Biermann Dirk , Walther Frank
Published: September 2018

In many technical fields, high-strength steels like AISI 4140 are commonly used for highly dynamically loaded parts. Increasing demands on weight, performance and efficiency of the automotive industry lead to increasing demands on material properties. For surface conditioning, optimised machining processes are capable of improving the fatigue performance without increasing the production cost significantly. This paper compares the influence of three different sulphur contents and three different feed rates on the fatigue behaviour of deep hole drilled AISI 4140 fatigue specimens. The specimens were characterised regarding their surface condition, hardness and microstructure, and afterwards they were tested under fatigue loading for performance assessment. These tests were accompanied with Barkhausen noise analysis. The Barkhausen noise signal was detected by a custom-built sensor that is capable of detecting the magnetic values on the bore wall. Using this technique, a load-independent estimation of fatigue damage was established.
Leaching and Recovery of Rare-Earth Elements from Neodymium Magnet Waste Using Organic Acids
Authors: Gergoric Marino , Ravaux Christophe , Steenari Britt-Marie , Espegren Fredrik , Retegan Teodora
Published: September 2018

Over the last decade, rare-earth elements (REEs) have become critical in the European Union (EU) in terms of supply risk, and they remain critical to this day. End-of-life electronic scrap (e-scrap) recycling can provide a partial solution to the supply of REEs in the EU. One such product is end-of-life neodymium (NdFeB) magnets, which can be a feasible source of Nd, Dy, and Pr. REEs are normally leached out of NdFeB magnet waste using strong mineral acids, which can have an adverse impact on the environment in case of accidental release. Organic acids can be a solution to this problem due to easier handling, degradability, and less poisonous gas evolution during leaching. However, the literature on leaching NdFeB magnets waste with organic acids is very scarce and poorly investigated. This paper investigates the recovery of Nd, Pr, and Dy from NdFeB magnets waste powder using leaching and solvent extraction. The goal was to determine potential selectivity between the recovery of REEs and other impurities in the material. Citric acid and acetic acid were used as leaching agents, while di-(2-ethylhexyl) phosphoric acid (D2EHPA) was used for preliminary solvent extraction tests. The highest leaching efficiencies were achieved with 1 mol/L citric acid (where almost 100% of the REEs were leached after 24 h) and 1 mol/L acetic acid (where >95% of the REEs were leached). Fe and Co—two major impurities—were co-leached into the solution, and no leaching selectivity was achieved between the impurities and the REEs. The solvent extraction experiments with D2EHPA in Solvent 70 on 1 mol/L leachates of both acetic acid and citric acid showed much higher affinity for Nd than Fe, with better extraction properties observed in acetic acid leachate. The results showed that acetic acid and citric acid are feasible for the recovery of REEs out of NdFeB waste under certain conditions.
A High-Frequency-Compatible Miniaturized Bandpass Filter with Air-Bridge Structures Using GaAs-Based Integrated Passive Device Technology
Authors: Wang Zhi-Ji , Kim Eun-Seong , Liang Jun-Ge , Qiang Tian , Kim Nam-Young
Published: September 2018

This paper reports on the use of gallium arsenide-based integrated passive device technology for the implementation of a miniaturized bandpass filter that incorporates an intertwined circle-shaped spiral inductor and an integrated center-located capacitor. Air-bridge structures were introduced to the outer inductor and inner capacitor for the purpose of space-saving, thereby yielding a filter with an overall chip area of 1178 μm × 970 μm. Thus, not only is the chip area minimized, but the magnitude of return loss is also improved as a result of selective variation of bridge capacitance. The proposed device possesses a single passband with a central frequency of 1.71 GHz (return loss: 32.1 dB), and a wide fractional bandwidth (FBW) of 66.63% (insertion loss: 0.50 dB). One transmission zero with an amplitude of 43.42 dB was obtained on the right side of the passband at 4.48 GHz. Owing to its miniaturized chip size, wide FBW, good out-band suppression, and ability to yield high-quality signals, the fabricated bandpass filter can be implemented in various L-band applications such as mobile services, satellite navigation, telecommunications, and aircraft surveillance.
Effect of H2O2 on the Separation of Mo-Bi-Containing Ore by Flotation
Authors: Lin Shangyong , Liu Runqing , Sun Wei , Hu Yuehua , Han Haisheng
Published: September 2018

Hydrogen peroxide (H2O2) is a strong oxidizer that causes non-selective oxidation of sulfide minerals, and its influence on bismuth sulfide ores is not well-documented. In this study, H2O2 was proposed as an alternative bismuthinite depressant, and its effect on a Mo-Bi-containing ore was intensively investigated by batch flotation tests. Results showed that the addition of H2O2 significantly destabilized the froth phase, thus decreasing the solids and water recovery. The recovery of bismuth in molybdenum concentrate was dramatically decreased to 4.64% by H2O2 compared with that in the absence of H2O2 (i.e., 50.14%). The modified first-order kinetic model demonstrated that the flotation rate of molybdenite slightly declined after H2O2 addition, whereas that of bismuthinite was drastically reduced from 0.30 min−1 to 0.08 min−1 under the same condition. Simulation revealed that H2O2 affected the floatability of both molybdenite and bismuthinite but resulted in more detrimental effect to bismuthinite. Hence, H2O2 has the potential to act as an effective depressant in bismuth sulfide ore flotation.
Characterization of Mine Waste and Acid Mine Drainage Prediction by Simple Testing Methods in Terms of the Effects of Sulfate-Sulfur and Carbonate Minerals
Authors: Matsumoto Shinji , Ishimatsu Hirotaka , Shimada Hideki , Sasaoka Takashi , Kusuma Ginting Jalu
Published: September 2018

Characterization of mine waste rocks and prediction of acid mine drainage (AMD) play an important role in preventing AMD. Although high-tech analytical methods have been highlighted for mineral characterization and quantification, simple testing methods are still practical ways to perform in a field laboratory in mines. Thus, this study applied some simple testing methods to the characterization of mine wastes and AMD prediction in addition to a leaching test and the sequential extraction test with HCl, HF, and HNO3, which have not been applied for these purposes, focusing on the form of sulfur and the neutralization effects of carbonates. The results of the Acid Buffering Characteristic Curve test supported the changing trend of the pH attributing carbonates only during the first 10 leaching cycles in the leaching test. The change in the Net Acid Generating (NAG) pH in the sequential NAG test reflected the solubility of sulfur in the rocks, providing information on the form of sulfur in the rocks and the acid-producing potential over time. Consequently, the sequential NAG test and sequential extraction with the acids in combination with the current standards tests (Acid Base Accounting and NAG tests) provided important information for preventing AMD.
Selection and Identification of Novel Aptamers Specific for Clenbuterol Based on ssDNA Library Immobilized SELEX and Gold Nanoparticles Biosensor
Authors: Liu Xixia , Lu Qi , Chen Sirui , Wang Fang , Hou Jianjun , Xu Zhenlin , Meng Chen , Hu Tianyuan , Hou Yaoyao
Published: September 2018

We describe a multiple combined strategy to discover novel aptamers specific for clenbuterol (CBL). An immobilized ssDNA library was used for the selection of specific aptamers using the systematic evolution of ligands by exponential enrichment (SELEX). Progress was monitored using real-time quantitative PCR (Q-PCR), and the enriched library was sequenced by high-throughput sequencing. Candidate aptamers were picked and preliminarily identified using a gold nanoparticles (AuNPs) biosensor. Bioactive aptamers were characterized for affinity, circular dichroism (CD), specificity and sensitivity. The Q-PCR amplification curve increased and the retention rate was about 1% at the eighth round. Use of the AuNPs biosensor and CD analyses determined that six aptamers had binding activity. Affinity analysis showed that aptamer 47 had the highest affinity (Kd = 42.17 ± 8.98 nM) with no cross reactivity to CBL analogs. Indirect competitive enzyme linked aptamer assay (IC-ELAA) based on a 5′-biotin aptamer 47 indicated the limit of detection (LOD) was 0.18 ± 0.02 ng/L (n = 3), and it was used to detect pork samples with a mean recovery of 83.33–97.03%. This is the first report of a universal strategy including library fixation, Q-PCR monitoring, high-throughput sequencing, and AuNPs biosensor identification to select aptamers specific for small molecules.
Anti-Inflammatory and Skin-Moisturizing Effects of a Flavonoid Glycoside Extracted from the Aquatic Plant Nymphoides indica in Human Keratinocytes
Authors: Kim You Ah , Kim Dong Hee , Park Chae Bin , Park Tae Soon , Park Byoung Jun
Published: September 2018

Nymphoides indica, an aquatic plant, is used as folk medicine in some countries. Our previous study demonstrated that the methanol extract of N. indica inhibited the activity of tyrosinases, tyrosine related protein (TRP)1 and TRP2, and microphthalmia-associated transcription factor, as well as the activity of protein kinase A, by effectively inhibiting cyclic adenosine monophosphate. Although the biological activities of N. indica extract have been reported, there are no reports on the skin bioactivity of the main compound(s) on human keratinocytes. This study investigated the anti-inflammatory and moisturizing effects of quercetin 3,7-dimethyl ether 4′-glucoside (QDG) isolated from N. indica. In brief, ultraviolet B irradiated keratinocytes were pretreated with different concentrations of QDG, and the effects of QDG on various inflammatory markers were determined. QDG significantly inhibited inflammation-related cytokines and chemokines and enhanced the activation of skin barrier factors. Additionally, QDG also attenuated phosphorylation inhibition of the upstream cytokines and nuclear factor-κB expression. These results suggest that QDG isolated from N. indica may serve as a potential source of bioactive substances for chronic inflammatory skin diseases.
Natural Peptides in Drug Discovery Targeting Acetylcholinesterase
Authors: Prasasty Vivitri , Radifar Muhammad , Istyastono Enade
Published: September 2018

Acetylcholinesterase-inhibitory peptide has gained much importance since it can inhibit acetylcholinesterase (AChE) and increase the availability of acetylcholine in cholinergic synapses, enhancing cholinergic transmission in pharmacological treatment of Alzheimer’s disease (AD). Natural peptides have received considerable attention as biologically important substances as a source of AChE inhibitors. These natural peptides have high potential pharmaceutical and medicinal values due to their bioactivities as neuroprotective and neurodegenerative treatment activities. These peptides have attracted great interest in the pharmaceutical industries, in order to design potential peptides for use in the prophylactic and therapy purposes. Some natural peptides and their derivatives have high commercial values and have succeeded in reaching the pharmaceutical market. A large number of peptides are already in preclinical and clinical pipelines for treatment of various diseases. This review highlights the recent researches on the various natural peptides and future prospects for AD management.
Bioavailability of Tea Catechins and Its Improvement
Authors: Cai Zhuo-Yu , Li Xu-Min , Liang Jin-Pei , Xiang Li-Ping , Wang Kai-Rong , Shi Yun-Long , Yang Rui , Shi Meng , Ye Jian-Hui , Lu Jian-Liang , Zheng Xin-Qiang , Liang Yue-Rong
Published: September 2018

Many in vitro studies have shown that tea catechins had vevarious health beneficial effects. However, inconsistent results between in vitro and in vivo studies or between laboratory tests and epidemical studies are observed. Low bioavailability of tea catechins was an important factor leading to these inconsistencies. Research advances in bioavailability studies involving absorption and metabolic biotransformation of tea catechins were reviewed in the present paper. Related techniques for improving their bioavailability such as nanostructure-based drug delivery system, molecular modification, and co-administration of catechins with other bioactives were also discussed.
Dose-Related Antihypertensive Properties and the Corresponding Mechanisms of a Chicken Foot Hydrolysate in Hypertensive Rats
Authors: Mas-Capdevila Anna , Pons Zara , Aleixandre Amaya , Bravo Francisca I. , Muguerza Begoña
Published: September 2018

The antihypertensive properties of different doses of a chicken foot hydrolysate, Hpp11 and the mechanisms involved in this effect were investigated. Spontaneously hypertensive rats (SHR) were administered water, Captopril (50 mg/kg) or Hpp11 at different doses (25, 55 and 85 mg/kg), and the systolic blood pressure (SBP) was recorded. The SBP of normotensive Wistar-Kyoto (WKY) rats administered water or Hpp11 was also recorded. Additionally, plasmatic angiotensin-converting enzyme (ACE) activity was determined in the SHR administered Hpp11. Moreover, the relaxation caused by Hpp11 in isolated aortic rings from Sprague-Dawley rats was evaluated. Hpp11 exhibited antihypertensive activity at doses of 55 and 85 mg/kg, with maximum activity 6 h post-administration. At this time, no differences were found between these doses and Captopril. Initial SBP values of 55 and 85 mg/kg were recovered 24 or 8 h post-administration, respectively, 55 mg/kg being the most effective dose. At this dose, a reduction in the plasmatic ACE activity in the SHR was found. However, Hpp11 did not relax the aortic ring preparations. Therefore, ACE inhibition could be the mechanism underlying Hpp11 antihypertensive effect. Remarkably, Hpp11 did not modify SBP in WKY rats, showing that the decreased SBP effect is specific to the hypertensive state.
Food Choice Priorities Change Over Time and Predict Dietary Intake at the End of the First Year of College Among Students in the U.S.
Authors: Vilaro Melissa J. , Colby Sarah E. , Riggsbee Kristin , Zhou Wenjun , Byrd-Bredbenner Carol , Olfert Melissa D. , Barnett Tracey E. , Horacek Tanya , Sowers Morgan , Mathews Anne E.
Published: September 2018

This study assessed food choice priorities (FCP) and associations with consumption of fruits and vegetables (FV), fiber, added sugars from non-beverage sources, and sugar-sweetened beverages (SSB) among college students. Freshmen from eight U.S. universities (N = 1149) completed the Food Choice Priorities Survey, designed for college students to provide a way to determine the factors of greatest importance regarding food choices, and the NCI Dietary Screener Questionnaire. Changes in FCP and dietary intake from fall 2015 to spring 2016 were assessed. Multiple regression models examined associations between FCP and log-transformed dietary intake, controlling for sex, age, race, and BMI. Participant characteristics and FCP associations were also assessed. FCP importance changed across the freshmen year and significantly predicted dietary intake. The most important FCP were price, busy daily life and preferences, and healthy aesthetic. Students who endorsed healthy aesthetic factors (health, effect on physical appearance, freshness/quality/in season) as important for food choice, consumed more FV and fiber and less added sugar and SSB. Busy daily life and preferences (taste, convenience, routine, ability to feel full) predicted lower FV, higher added sugar, and higher SSB consumption. Price predicted lower FV, higher SSB, and more added sugar while the advertising environment was positively associated with SSB intake. FCP and demographic factors explained between 2%–17% of the variance in dietary intake across models. The strongest relationship was between healthy aesthetic factors and SSB (B = −0.37, p < 0.01). Self-rated importance of factors influencing food choice are related to dietary intake among students. Interventions that shift identified FCP may positively impact students’ diet quality especially considering that some FCP increase in importance across the first year of college.
Mucosal Applications of Poloxamer 407-Based Hydrogels: An Overview
Authors: Giuliano Elena , Paolino Donatella , Fresta Massimo , Cosco Donato
Published: September 2018

Poloxamer 407, also known by the trademark Pluronic® F127, is a water-soluble, non-ionic triblock copolymer that is made up of a hydrophobic residue of polyoxypropylene (POP) between the two hydrophilic units of polyoxyethylene (POE). Poloxamer 407-based hydrogels exhibit an interesting reversible thermal characteristic. That is, they are liquid at room temperature, but they assume a gel form when administered at body temperature, which makes them attractive candidates as pharmaceutical drug carriers. These systems have been widely investigated in the development of mucoadhesive formulations because they do not irritate the mucosal membranes. Based on these mucoadhesive properties, a simple administration into a specific compartment should maintain the required drug concentration in situ for a prolonged period of time, decreasing the necessary dosages and side effects. Their main limitations are their modest mechanical strength and, notwithstanding their bioadhesive properties, their tendency to succumb to rapid elimination in physiological media. Various technological approaches have been investigated in the attempt to modulate these properties. This review focuses on the application of poloxamer 407-based hydrogels for mucosal drug delivery with particular attention being paid to the latest published works.
Improve the Performance of Soy Protein-Based Adhesives by a Polyurethane Elastomer
Authors: Xu Yecheng , Xu Yantao , Zhu Wenjie , Zhang Wei , Gao Qiang , Li Jianzhang
Published: September 2018

The purpose of this study was to improve the performance of soy protein isolate (SPI) adhesives using a polyurethane elastomer. Triglycidylamine (TGA), SPI, thermoplastic polyurethane elastomer (TPU), and γ-(2,3-epoxypropoxy) propyltrimethoxysilane (KH-560) were used to develop a novel SPI-based adhesive. The residual rate, functional groups, thermal stability, and fracture surface micrographs of the cured adhesives were characterized. Three-ply plywood was fabricated, and the dry/wet shear strength was determined. The experimental results suggested that introducing 2% TGA improved the residual rate of the SPI/TGA adhesive by 4.1% because of the chemical cross-linking reaction between epoxy groups and protein molecules. Incorporating 7% TPU into the SPI/TGA adhesive, the residual rate of the adhesive increased by 5.2% and the dry/wet shear strength of plywood bonded by SPI/TGA/TPU adhesive increased by 10.7%/67.7%, respectively, compared with that of SPI/TGA adhesive. When using KH-560 and TPU together, the residual rate of the adhesive improved by 0.9% compared with that of SPI/TGA/TPU adhesive. The dry and wet shear strength of the plywood bonded by the SPI/TGA/TPU/KG-560 adhesive further increased by 23.2% and 23.6% respectively when compared with that of SPI/TGA/TPU adhesive. TPU physically combined with the SPI/TGA adhesive to form a interpenetration network and KH-560 acted as a bridge to connect TPU and SPI/TGA to form a joined crosslinking network, which improved the thermo stability/toughness of the adhesive and created a uniform ductile fracture section of the adhesive.