bluuebunny/crossref_metadata_2025 huggingface dataset:
Andrographolide Protects PC12 Cells Against β-Amyloid-Induced Autophagy-Associated Cell Death Through Activation of the Nrf2-Mediated p62 Signaling Pathway
Authors: Gu Lili , Yu Qingqing , Li Qin , Zhang Lingxi , Lu Hong , Zhang Xinyue
Published: September 2018

Recent studies mentioned that Andrographolide (Andro), the main bioactive component of traditional Chinese medicine Andrographis paniculata, may be a potential natural product for treating Alzheimer's disease, but the underlining mechanism remains to be discovered. In this study, we investigated whether Andro regulates the nuclear factor E2-related factor 2 (Nrf2)/Sequestosome 1 (p62) signaling pathway and activates autophagy to protect neuronal PC12 cells from the toxicity of the β-amyloid (Aβ) peptide. Our results revealed that Andro protected and rescued PC12 cells from Aβ1–42-induced cell death and restored abnormal changes in nuclear morphology, lactate dehydrogenase, malondialdehyde, intracellular reactive oxygen species, and mitochondrial membrane potential. RT-PCR and Western blotting analysis demonstrated that Andro activated autophagy-related genes and proteins (Beclin-1 and LC3); meanwhile, it also augmented the Nrf2 and p62 expression in mRNA and protein levels, and reduced p-tau and p21 protein expression in Aβ1–42-stimulated cells. Then, further study showed that the pre-transfection of cells with Nrf2 small interfering RNA (siRNA) resulted in the downregulation of p62, Beclin-1, and LC3 proteins expression, as well as the upregulation of p21. Furthermore, the pre-transfection of cells with p62 siRNA didn’t block the Nrf2 protein expression, accompanying with an elevated p21. Taken together, these results showed that Andro significantly ameliorated cell death due to Aβ1–42 insult through the activation of autophagy and the Nrf2-mediated p62 signaling pathway.
Visual Saliency Model-Based Image Watermarking with Laplacian Distribution
Authors: Liu Hongmei , Liu Jinhua , Zhao Mingfeng
Published: September 2018

To improve the invisibility and robustness of the multiplicative watermarking algorithm, an adaptive image watermarking algorithm is proposed based on the visual saliency model and Laplacian distribution in the wavelet domain. The algorithm designs an adaptive multiplicative watermark strength factor by utilizing the energy aggregation of the high-frequency wavelet sub-band, texture masking and visual saliency characteristics. Then, the image blocks with high-energy are selected as the watermark embedding space to implement the imperceptibility of the watermark. In terms of watermark detection, the Laplacian distribution model is used to model the wavelet coefficients, and a blind watermark detection approach is exploited based on the maximum likelihood scheme. Finally, this paper performs the simulation analysis and comparison of the performance of the proposed algorithm. Experimental results show that the proposed algorithm is robust against additive white Gaussian noise, JPEG compression, median filtering, scaling, rotation attack and other attacks.
Design of SnO2 Aggregate/Nanosheet Composite Structures Based on Function-Matching Strategy for Enhanced Dye-Sensitized Solar Cell Performance
Authors: Wang Dongting , Liu Shangheng , Shao Mingfa , Zhao Jinghan , Gu Yukun , Li Qiuyi , Zhang Xianxi , Zhao Jinsheng , Fang Yuzhen
Published: September 2018

Hierarchical SnO2 nanocrystallites aggregates (NAs) were prepared with a simple room temperature–based aqueous solution method followed by simple freeze-drying treatment. The as-prepared SnO2 NAs were subsequently combined with SnO2 nanosheet–based structures from the viewpoint of a function-matching strategy, and under an optimized condition, a power conversion efficiency (PCE) of 5.59% was obtained for the resultant hybrid photoanode, a remarkable 60% enhancement compared to that of dye-sensitized solar cells (DSCs) fabricated with bare SnO2 NAs architecture. The significantly enhanced efficiency can be attributed to the combination of the desirable electron transport property obtained by the intentionally introduced SnO2 nanosheets (NSs) and the effectively retained inherent characteristics of SnO2 NAs, i.e., large surface area and strong light-scattering effect. This work provides a promising approach for the rapid development of highly efficient SnO2 photoanode film-based DSCs with the properties of simplicity of operation and control over the photoanode composition.
Photocatalytic Degradation of Diclofenac by Hydroxyapatite–TiO2 Composite Material: Identification of Transformation Products and Assessment of Toxicity
Authors: Murgolo Sapia , Moreira Irina S. , Piccirillo Clara , Castro Paula M. L. , Ventrella Gianrocco , Cocozza Claudio , Mascolo Giuseppe
Published: September 2018

Diclofenac (DCF) is one of the most detected pharmaceuticals in environmental water matrices and is known to be recalcitrant to conventional wastewater treatment plants. In this study, degradation of DCF was performed in water by photolysis and photocatalysis using a new synthetized photocatalyst based on hydroxyapatite and TiO2 (HApTi). A degradation of 95% of the target compound was achieved in 24 h by a photocatalytic treatment employing the HApTi catalyst in comparison to only 60% removal by the photolytic process. The investigation of photo-transformation products was performed by means of UPLC-QTOF/MS/MS, and for 14 detected compounds in samples collected during treatment with HApTi, the chemical structure was proposed. The determination of transformation product (TP) toxicity was performed by using different assays: Daphnia magna acute toxicity test, Toxi-ChromoTest, and Lactuca sativa and Solanum lycopersicum germination inhibition test. Overall, the toxicity of the samples obtained from the photocatalytic experiment with HApTi decreased at the end of the treatment, showing the potential applicability of the catalyst for the removal of diclofenac and the detoxification of water matrices.
Assessment of Migration of Human MSCs through Fibrin Hydrogels as a Tool for Formulation Optimisation
Authors: Salam Nasseem , Toumpaniari Sotiria , Gentile Piergiorgio , Marina Ferreira Ana , Dalgarno Kenneth , Partridge Simon
Published: September 2018

Control of cell migration is fundamental to the performance of materials for cell delivery, as for cells to provide any therapeutic effect, they must migrate out from the delivery material. Here the influence of fibrinogen concentration on the migration of encapsulated human mesenchymal stem cells (hMSCs) from a cell spheroid through fibrin hydrogels is tracked over time. Fibrin was chosen as a model material as it is routinely employed as a haemostatic agent and more recently has been applied as a localised delivery vehicle for potential therapeutic cell populations. The hydrogels consisted of 5 U/mL thrombin and between 5 and 50 mg/mL fibrinogen. Microstructural and viscoelastic properties of different compositions were evaluated using SEM and rheometry. Increasing the fibrinogen concentration resulted in a visibly denser matrix with smaller pores and higher stiffness. hMSCs dispersed within the fibrin gels maintained cell viability post-encapsulation, however, the migration of cells from an encapsulated spheroid revealed that denser fibrin matrices inhibit cell migration. This study provides the first quantitative study on the influence of fibrinogen concentration on 3D hMSC migration within fibrin gels, which can be used to guide material selection for scaffold design in tissue engineering and for the clinical application of fibrin sealants.
Synthesis and Exploration of the Lubricating Behavior of Nanoparticulated Mo15S19 in Linseed Oil
Authors: Fernández-Coppel Ignacio A. , Martín-Ramos Pablo , Martín-Gil Jesús , Pamies Ramón , Avella Manuel , Avilés María Dolores
Published: September 2018

Molybdenum chalcogenides present interesting properties beyond their superconducting critical temperatures and upper critical magnetic fields, making them suitable for potential applications in tribology, batteries, catalysis, or thermopower. In this study, Mo15S19 nanoparticles with an average diameter of 10 nm were synthesized via the reaction of ammonium molybdate with hydrochloric acid and elemental sulfur as reducers at 245 °C. The oxidation to MoO3 in air was efficiently avoided by using linseed oil as a reaction medium and dispersant. Scanning electron microscopy (SEM) micrographs of the as-prepared samples revealed the presence of few-micron-size aggregates, while transmission electron microscopy (TEM) characterization evidenced that the samples were polynanocrystalline with a high degree of homogeneity in size (standard deviation of 2.7 nm). The absence of the first-order (00l) reflection in the X-ray diffraction pattern was also indicative of the absence of Mo3S4 stacking, suggesting that it was a non-layered material. A dispersion of the nanoparticles in linseed oil has been studied as a lubricant of steel–steel sliding contacts, showing the formation of a surface layer that reduces wear and mean friction coefficients with respect to the base oil.
Fabrication of Porous Al2O3 Ceramics with Submicron-Sized Pores Using a Water-Based Gelcasting Method
Authors: Yang Zhihong , Chen Nan , Qin Xiaomei
Published: September 2018

The gelcasting method is usually employed to fabricate relatively dense ceramics. In this work, however, porous Al2O3 ceramics with submicron-sized pores were fabricated using the water-based gelcasting method by keeping the Al2O3 content at low levels. By controlling the water content in the ceramic slurries and the sintering temperature of the green samples, the volume fractions and the size characteristics of the pores in the porous Al2O3 can be readily obtained. For the porous Al2O3 ceramics prepared with 30 vol.% Al2O3 content in the slurries, their open porosities were from 38.3% to 47.2%, while their median pore sizes varied from 299.8 nm to 371.9 nm. When there was more Al2O3 content in the slurries (40 vol.% Al2O3), the porous Al2O3 ceramics had open porosities from 37.0% to 46.5%, and median pore sizes from 355.4 nm to 363.1 nm. It was found that a higher sintering temperature and Al2O3 content in the slurries increased the mechanical strength of the porous Al2O3 ceramics.
Cloning of the Bisucaberin B Biosynthetic Gene Cluster from the Marine Bacterium Tenacibaculum mesophilum, and Heterologous Production of Bisucaberin B
Authors: Fujita Masaki J. , Goto Yusuke , Sakai Ryuichi
Published: September 2018

The biosynthetic gene cluster for bisucaberin B (1, bsb gene cluster), an N-hydroxy-N-succinyl diamine (HSD)-based siderophore, was cloned from the marine bacterium Tenacibaculum mesophilum, originated from a marine sponge. The bsb gene cluster consists of six open reading frames (ORFs), in contrast to the four ORFs typically seen in biosynthetic gene clusters of the related molecules. Heterologous expression of the key enzyme, BsbD2, which is responsible for the final biosynthetic step of 1 resulted in production of bisucaberin B (1), but not bisucaberin (2) a macrocyclic counterpart of 1. To date, numbers of related enzymes producing macrocyclic analogues have been reported, but this work represents the first example of the HSD-based siderophore biosynthetic enzyme which exclusively produces a linear molecule rather than macrocyclic counterparts.
Cardiac Magnetic Resonance Imaging (MRI) Findings in Arrhythmogenic Right Ventricular Dysplasia (ARVD) Compared with Echocardiography
Authors: Motevali Marzie , Siahi Zainab , Mohammadzadeh Ali , Sangi Akbar
Published: September 2018

Arrhythmogenic right ventricular dysplasia (ARVD) is an abnormality in the right side of the heart that may lead to sudden death. The study aims to compare cardiac MRI (magnetic resonance imaging findings) with echocardiography in patients with ARVD. For the cross-sectional study, patients with ARVD that were diagnosed using Task Force criteria were included, and their cardiac MRI findings were evaluated. Additionally, the right ventricle was divided into three levels—basal, middle, and apical—and each of them was also subdivided into three secondary segments. Gadolinium enhancement was evaluated in each segment. Overall, 39 patients were studied. Thirty-one patients (81%) were men. The average age of female and male patients was 37.8 ± 4.6 and 32.48 ± 5.8, respectively. The average ejection fraction found was 43 ± 9.4 and 42.8 ± 8.5% by MRI and echocardiography, respectively. Additionally, 46 and 35.8% of the patients had hypokinesia in the right ventricle, found based on MRI and echocardiography, respectively. The right ventricular aneurysm was found in 20.5 and 5.1% of patients based on MRI and echocardiography, respectively. The cardiac MRI managed to diagnose some cases which echocardiography was not able to detect. Thus, MRI plays an important role in presenting diagnostic data for the management of patients with ARVD and also making the diagnosis in suspicious patients definitive.
1D Mathematical Modelling of Non-Stationary Ion Transfer in the Diffusion Layer Adjacent to an Ion-Exchange Membrane in Galvanostatic Mode
Authors: Uzdenova Aminat , Kovalenko Anna , Urtenov Makhamet , Nikonenko Victor
Published: September 2018

The use of the Nernst–Planck and Poisson (NPP) equations allows computation of the space charge density near solution/electrode or solution/ion-exchange membrane interface. This is important in modelling ion transfer, especially when taking into account electroconvective transport. The most solutions in literature use the condition setting a potential difference in the system (potentiostatic or potentiodynamic mode). However, very often in practice and experiment (such as chronopotentiometry and voltammetry), the galvanostatic/galvanodynamic mode is applied. In this study, a depleted stagnant diffusion layer adjacent to an ion-exchange membrane is considered. In this article, a new boundary condition is proposed, which sets a total current density, i, via an equation expressing the potential gradient as an explicit function of i. The numerical solution of the problem is compared with an approximate solution, which is obtained by a combination of numerical solution in one part of the diffusion layer (including the electroneutral region and the extended space charge region, zone (I) with an analytical solution in the other part (the quasi-equilibrium electric double layer (EDL), zone (II). It is shown that this approach (called the “zonal” model) allows reducing the computational complexity of the problem tens of times without significant loss of accuracy. An additional simplification is introduced by neglecting the thickness of the quasi-equilibrium EDL in comparison to the diffusion layer thickness (the “simplified” model). For the first time, the distributions of concentrations, space charge density and current density along the distance to an ion-exchange membrane surface are computed as functions of time in galvanostatic mode. The calculation of the transition time, τ, for an ion-exchange membrane agree with an experiment from literature. It is suggested that rapid changes of space charge density, and current density with time and distance, could lead to lateral electroosmotic flows delaying depletion of near-surface solution and increasing τ.
Rare Earth and Phosphorus Leaching from a Flotation Tailings of Florida Phosphate Rock
Authors: Liang Haijun , Zhang Patrick , Jin Zhen , DePaoli David W.
Published: September 2018

Phosphorite, or phosphate rock, is the raw material of phosphoric acid production. It has also been regarded as the most important secondary rare earth element (REE) resource due to low contents of rare earth elements contained in the ore. In Florida, there is about 19 Mt of phosphate rock mined annually. After beneficiation, the phosphate rock concentrate is utilized to produce phosphoric acid via a wet-process in which sulfuric acid is used to digest phosphate. During these processes, REEs and some phosphorus get lost in the byproducts including phosphatic clay, flotation tailings, phosphogypsum (PG), and phosphoric sludge. Recovering REEs and phosphorus from these wastes is beneficial to maximize the utilization of these valuable resources. This study focused on the effects of wet-process operating conditions on REE and phosphorus leaching from a kind of flotation tailing of Florida phosphate rock. The tailings were first beneficiated with a shaking table, and then a series of leaching tests were conducted on the shaking table concentrate. The results indicated that REEs had similar trends of leaching efficiency to those of phosphorus. Under the conditions of 16% phosphoric acid concentration in the initial pulp, a temperature of 75 °C, a stoichiometric ratio of sulfuric acid (H2SO4) to calcium oxide (CaO) of 1.1, and a weight ratio of liquid to solid of 3.5, REE and phosphorus leaching efficiencies reached relatively high values of approximately 61% and 91%, respectively. Analyses indicated that the phosphate ions (PO43−) in the leaching solution tended to combine with REE ions to form REE phosphates which precipitated into PG, but the other large amount of anions such as sulfate ions (SO42−) and fluoride ions (F−) took effect of steric hindrance to prevent PO43− from combining with REE cations. These two opposite effects determined the REE distribution between the leaching solution and PG.
Platycodon grandiflorum Saponins Ameliorate Cisplatin-Induced Acute Nephrotoxicity through the NF-κB-Mediated Inflammation and PI3K/Akt/Apoptosis Signaling Pathways
Authors: Zhang Weizhe , Hou Jingang , Yan Xiaotong , Leng Jing , Li Rongyan , Zhang Jing , Xing Jingjing , Chen Chen , Wang Zi , Li Wei
Published: September 2018

Although cisplatin is a potent chemotherapeutic agent against cancers, its clinical application is seriously limited by its severe side effects of nephrotoxicity. Previous studies reported that saponins isolated from the roots of Platycodon grandiflorum (PGS) exerted protective effects in various animal models of renal injury, with no confirmation on cisplatin-induced injury. This study was designed to investigate the protective effect of PGS (15 and 30 mg/kg) on cisplatin-induced kidney injury in mice. The levels of serum creatinine (CRE) and blood urea nitrogen (BUN), and renal histopathology demonstrated the protective effect of PGS against cisplatin-induced kidney injury. PGS exerted anti-inflammation effects via suppressing nuclear factor-kappa B (NF-κB) activation and alleviating the cisplatin-induced increase in inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), tumor necrosis factor-α (TNF-α), and interleukin-1β (IL-1β) in kidney tissues. The expressions of phosphorylation of phosphatidylinositol 3-kinase/protein kinase B and its downstream apoptotic factors, such as Bcl-2 and caspase families were regulated by PGS in a dose-dependent manner. In conclusion, PGS exerted kidney protection effects against cisplatin-induced kidney injury by inhibiting the activation of NF-κB and regulating PI3K/Akt/apoptosis signaling pathways in mice.
Clinical Significance of Phase Angle in Non-Dialysis CKD Stage 5 and Peritoneal Dialysis Patients
Authors: Han Byoung-Geun , Lee Jun Young , Kim Jae-Seok , Yang Jae-Won
Published: September 2018

Background: Fluid overload and protein-energy wasting (PEW) are common in patients with end-stage renal disease (ESRD) and lead to a poor prognosis. We aimed to evaluate the volume and nutritional status of ESRD patients and to determine the clinical significance of phase angle (PhA). Methods: This study was a cross-sectional comparison of bioimpedance spectroscopy (BIS) findings in patients with non-dialysis chronic kidney disease (CKD) stage 5 (CKD5-ND, N = 80) and age/sex-matched peritoneal dialysis patients (PD, N = 80). PEW was defined as a PhA less than 4.5°. Results: The PhA was found to be positively associated with a geriatric nutritional risk index (GNRI, r = 0.561, p < 0.001), lean tissue index (LTI, r = 0.473, p < 0.001), and albumin (r = 0.565, p < 0.001) while OH/ECW (r = −0.824, p < 0.001) showed an inverse correlation. The CKD5-ND group had more overhydration (p = 0.027). The PD group had significantly higher PhA (p = 0.023), GNRI (p = 0.005), hemoglobin (p < 0.001), and albumin (p = 0.003) than the CKD5-ND group. The cut-off values predicting PEW were found to be 3.55 g/dL for albumin, 94.9 for GNRI, and 12.95 kg/m2 for LTI in PD patients. Conclusions: This study demonstrated that PhA could be used as a marker to reflect nutritional status in patients with ESRD. Since BIS can inform both volume and nutritional status, regular monitoring will provide the basis for active correction of fluid overload and nutritional supplementation, which may improve outcomes in patients with ESRD.
Iron in Friedreich Ataxia: A Central Role in the Pathophysiology or an Epiphenomenon?
Authors: Alsina David , Purroy Rosa , Ros Joaquim , Tamarit Jordi
Published: September 2018

Friedreich ataxia is a neurodegenerative disease with an autosomal recessive inheritance. In most patients, the disease is caused by the presence of trinucleotide GAA expansions in the first intron of the frataxin gene. These expansions cause the decreased expression of this mitochondrial protein. Many evidences indicate that frataxin deficiency causes the deregulation of cellular iron homeostasis. In this review, we will discuss several hypotheses proposed for frataxin function, their caveats, and how they could provide an explanation for the deregulation of iron homeostasis found in frataxin-deficient cells. We will also focus on the potential mechanisms causing cellular dysfunction in Friedreich Ataxia and on the potential use of the iron chelator deferiprone as a therapeutic agent for this disease.
Doxorubicin-Conjugated PAMAM Dendrimers for pH-Responsive Drug Release and Folic Acid-Targeted Cancer Therapy
Authors: Zhang Mengen , Zhu Jingyi , Zheng Yun , Guo Rui , Wang Shige , Mignani Serge , Caminade Anne-Marie , Majoral Jean-Pierre , Shi Xiangyang
Published: September 2018

We present here the development of multifunctional doxorubicin (DOX)-conjugated poly(amidoamine) (PAMAM) dendrimers as a unique platform for pH-responsive drug release and targeted chemotherapy of cancer cells. In this work, we covalently conjugated DOX onto the periphery of partially acetylated and folic acid (FA)-modified generation 5 (G5) PAMAM dendrimers through a pH-sensitive cis-aconityl linkage to form the G5.NHAc-FA-DOX conjugates. The formed dendrimer conjugates were well characterized using different methods. We show that DOX release from the G5.NHAc-FA-DOX conjugates follows an acid-triggered manner with a higher release rate under an acidic pH condition (pH = 5 or 6, close to the acidic pH of tumor microenvironment) than under a physiological pH condition. Both in vitro cytotoxicity evaluation and cell morphological observation demonstrate that the therapeutic activity of dendrimer-DOX conjugates against cancer cells is absolutely related to the DOX drug released. More importantly, the FA conjugation onto the dendrimers allowed a specific targeting to cancer cells overexpressing FA receptors (FAR), and allowed targeted inhibition of cancer cells. The developed G5.NHAc-FA-DOX conjugates may be used as a promising nanodevice for targeted cancer chemotherapy.
Protein Transduction Domain Mimic (PTDM) Self-Assembly?
Authors: D. Posey Nicholas , N. Tew Gregory
Published: September 2018

Intracellular protein delivery is an invaluable tool for biomedical research, as it enables fundamental studies of cellular processes and creates opportunities for novel therapeutic development. Protein delivery reagents such as cell penetration peptides (CPPs) and protein transduction domains (PTDs) are frequently used to facilitate protein delivery. Herein, synthetic polymer mimics of PTDs, called PTDMs, were studied for their ability to self-assemble in aqueous media as it was not known whether self-assembly plays a role in the protein binding and delivery process. The results obtained from interfacial tensiometry (IFT), transmission electron microscopy (TEM), transmittance assays (%T), and dynamic light scattering (DLS) indicated that PTDMs do not readily aggregate or self-assemble at application-relevant time scales and concentrations. However, additional DLS experiments were used to confirm that the presence of protein is required to induce the formation of PTDM-protein complexes and that PTDMs likely bind as single chains.
Theoretical Study on the Grafting Reaction of Maleimide to Polyethylene in the UV Radiation Cross-Linking Process
Authors: Zhang Hui , Shang Yan , Zhao Hong , Li Chunyang , Wang Xuan , Han Baozhong , Li Zesheng
Published: September 2018

Theoretical investigation of the reaction of graft maleimide to polyethylene in the UV radiation cross-linking process is accomplished at the B3LYP/6-311+G(d,p) level for high-voltage cable insulation materials. The reaction potential energy surface of the nine reaction channels is identified. The results show that the N,N′-ethylenedimaleimide can connect two 4-methylheptane molecules and act as the cross-linking agent. The calculated reaction potential barrier of forming 4-methylheptane radical by maleimide is higher than that of maleic anhydride. The study is expected to provide a basis for optimizing the UV radiation cross-linking polyethylene process and development more than 500 kV high-voltage cable insulation materials in practical applications.
Plasticity Enhancement by Fe-Addition on NiAl Alloy: A Synchrotron X-ray Diffraction Mapping and Molecular Dynamics Simulation Study
Authors: Huang E-Wen , Lam Tu-Ngoc , Chang I-Ling , Hong Wei-Jhih , Lin Tian-Yu , Su Chun-Jen , Liaw Peter , Santodonato Louis , Jayant Jain , Fine Morris
Published: September 2018

Unalloyed nickel aluminide has important applications but lacks ductility at room temperature. In this study, iron-added nickel aluminide alloys exhibit plasticity enhancement. The nickel aluminide alloys are prepared with different iron contents (0, 0.25, and 1 at%) to study their plasticity. The indentation-induced deformed areas are mapped by the synchrotron X-ray diffraction to compare their plastic zones. A complimentary tight binding calculation and generalized embedded atom method demonstrate how the Fe-addition enhances the plasticity of the iron-added nickel aluminide alloys.
Shedding Light on the Anthropogenic Europium Cycle in the EU–28. Marking Product Turnover and Energy Progress in the Lighting Sector
Authors: Ciacci Luca , Vassura Ivano , Passarini Fabrizio
Published: September 2018

Phase-out strategies for incandescent bulbs in favor of advanced energy-efficiency lighting systems such as fluorescent lamps and solid-state technology have considerably reduced the energy use for lighting, but have also resulted in dependence on many critical materials like rare earth elements and shifted the attention to sustainable use and recovery of resources. In this work, a dynamic material flow model was developed to analyze the socio-economic metabolism of europium in the EU–28. The analysis shows that europium marked product turnover and progress in lighting efficiency, with this element being employed both in traditional and novel lighting technology to provide luminescence. The results also demonstrate that the current anthropogenic reserve could constitute an attractive source of secondary europium with substantial potentials for environmental benefits. However, nonexistent recycling and market forces hinder strategies for material circularity. In particular, the transition from fluorescent lamps to solid-state technology is quickly decreasing the demand for europium. This trend adds further constraints to the creation of a sustainable recycling industry for europium, with primary sources that might remain the preferable route to supply phosphors to future lighting systems.
Irrigation Mapping Using Sentinel-1 Time Series at Field Scale
Authors: Gao Qi , Zribi Mehrez , Escorihuela Maria Jose , Baghdadi Nicolas , Segui Pere Quintana
Published: September 2018

The recently launched Sentinel-1 satellite with a Synthetic Aperture Radar (SAR) sensor onboard offers a powerful tool for irrigation monitoring under various weather conditions, with high spatial and temporal resolution. This research discusses the potential of different metrics calculated from the Sentinel-1 time series for mapping irrigated fields. A methodology for irrigation mapping using SAR data is proposed. The study is performed using VV (vertical–vertical) and VH (vertical–horizontal) polarizations over an agricultural site in Urgell, Catalunya (Spain). With field segmentation information from SIGPAC (the Geographic Information System for Agricultural Parcels), the backscatter intensities are averaged within each field. From the Sentinel-1 time series for each field, the statistics and metrics, including the mean value, the variance of the signal, the correlation length, and the fractal dimension, are analyzed. With the Support Vector Machine (SVM), the classification of irrigated crops, irrigated trees, and non-irrigated fields is performed with the metrics vector. The results derived from the SVM are validated with ground truthing from SIGPAC over the whole study area, with a good overall accuracy of 81.08%. Random Forest (RF) machine classification is also tested in this study, which gives an accuracy of around 82.2% when setting the tree depth at three. The methodology is based only on SAR data, which makes it applicable to all areas, even with frequent cloud cover, but this method may be less robust when irrigation is less dominated to soil moisture change.
Detecting Building Edges from High Spatial Resolution Remote Sensing Imagery Using Richer Convolution Features Network
Authors: Lu Tingting , Ming Dongping , Lin Xiangguo , Hong Zhaoli , Bai Xueding , Fang Ju
Published: September 2018

As the basic feature of building, building edges play an important role in many fields such as urbanization monitoring, city planning, surveying and mapping. Building edges detection from high spatial resolution remote sensing (HSRRS) imagery has always been a long-standing problem. Inspired by the recent success of deep-learning-based edge detection, a building edge detection model using a richer convolutional features (RCF) network is employed in this paper to detect building edges. Firstly, a dataset for building edges detection is constructed by the proposed most peripheral constraint conversion algorithm. Then, based on this dataset the RCF network is retrained. Finally, the edge probability map is obtained by RCF-building model, and this paper involves a geomorphological concept to refine edge probability map according to geometric morphological analysis of topographic surface. The experimental results suggest that RCF-building model can detect building edges accurately and completely, and that this model has an edge detection F-measure that is at least 5% higher than that of other three typical building extraction methods. In addition, the ablation experiment result proves that using the most peripheral constraint conversion algorithm can generate more superior dataset, and the involved refinement algorithm shows a higher F-measure and better visual effect contrasted with the non-maximal suppression algorithm.
Recent Progress and Developments in Imaging Spectroscopy
Authors: Kneubühler Mathias , Damm-Reiser Alexander
Published: September 2018

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Determining Subarctic Peatland Vegetation Using an Unmanned Aerial System (UAS)
Authors: Palace Michael , Herrick Christina , DelGreco Jessica , Finnell Daniel , Garnello Anthony John , McCalley Carmody , McArthur Kellen , Sullivan Franklin , Varner Ruth K.
Published: September 2018

Rising global temperatures tied to increases in greenhouse gas emissions are impacting high latitude regions, leading to changes in vegetation composition and feedbacks to climate through increased methane (CH4) emissions. In subarctic peatlands, permafrost collapse has led to shifts in vegetation species on landscape scales with high spatial heterogeneity. Our goal was to provide a baseline for vegetation distribution related to permafrost collapse and changes in biogeochemical processes. We collected unmanned aerial system (UAS) imagery at Stordalen Mire, Abisko, Sweden to classify vegetation cover types. A series of digital image processing routines were used to generate texture attributes within the image for the purpose of characterizing vegetative cover types. An artificial neural network (ANN) was developed to classify the image. The ANN used all texture variables and color bands (three spectral bands and six metrics) to generate a probability map for each of the eight cover classes. We used the highest probability for a class at each pixel to designate the cover type in the final map. Our overall misclassification rate was 32%, while omission and commission error by class ranged from 0% to 50%. We found that within our area of interest, cover classes most indicative of underlying permafrost (hummock and tall shrub) comprised 43.9% percent of the landscape. Our effort showed the capability of an ANN applied to UAS high-resolution imagery to develop a classification that focuses on vegetation types associated with permafrost status and therefore potentially changes in greenhouse gas exchange. We also used a method to examine the multiple probabilities representing cover class prediction at the pixel level to examine model confusion. UAS image collection can be inexpensive and a repeatable avenue to determine vegetation change at high latitudes, which can further be used to estimate and scale corresponding changes in CH4 emissions.
Investigation of Ground Deformation in Taiyuan Basin, China from 2003 to 2010, with Atmosphere-Corrected Time Series InSAR
Authors: Tang Wei , Yuan Peng , Liao Mingsheng , Balz Timo
Published: September 2018

Excessive groundwater exploitation is common through the Taiyuan basin, China, and is well known to result in ground subsidence. However, most ground subsidence studies in this region focus on a single place (Taiyuan city), and thus fail to demonstrate the regional extent of the deformation phenomena in the whole basin. In this study, we used Interferometric Synthetic Aperture Radar (InSAR) time series analysis to investigate land subsidence across the entire Taiyuan basin region. Our data set includes a total of 75 ENVISAT ASAR images from two different frames acquired from August 2003 to September 2010 and 33 TerraSAR-X scenes spanning between March 2009 and March 2010. ERA-Interim reanalysis was used to correct the stratified delay to reduce the bias expected from the systematic components of tropospheric delay. The residual delay after correction of stratified delay can be considered as a stochastic component and be mitigated through spatial-temporal filtering. A comparison with MERIS (Medium-Resolution Imaging Spectrometer) measurements indicates that our atmospheric corrections improved agreement over the conventional spatial-temporal filtering by about 20%. The displacement results from our atmosphere-corrected time series InSAR were further validated with continuous GPS data. We found eight subsiding centers in the basin and a surface uplift to the north of Taiyuan city. The causes of ground deformation are analyzed and discussed in relation to gravity data, pre-existing faults, and types of land use.
Feature Extraction from Indirect Monitoring in Marine Oil Separation Systems
Authors: Marichal Graciliano Nicolás , Ávila Deivis , Hernández Ángela , Padrón Isidro , Castejón Cristina
Published: September 2018

In this article, a study of characteristic vibrations of marine oils separation system is presented. Vibrations analysis allows for the extraction of representative features that could be related to the lifetime of their pieces. Actual measurements were carried out on these systems on Ro-Pax vessels to transport passengers and freight. The vibrations obtained were processed in the frequency domain and following this, they were used in a Genetic Neuro-Fuzzy System in order to design new predictive maintenance strategies. The obtained results show that these techniques as a promising strategy can be utilized to determine incipient faults.
Reduced Graphene Oxide-Based Double Network Polymeric Hydrogels for Pressure and Temperature Sensing
Authors: Liu Wei , Zhang Xiaoyuan , Wei Gang , Su Zhiqiang
Published: September 2018

We demonstrate the fabrication of novel reduced graphene oxide (rGO)-based double network (DN) hydrogels through the polymerization of poly(N-isopropylacrylamide) (PNIPAm) and carboxymethyl chitosan (CMC). The facile synthesis of DN hydrogels includes the reduction of graphene oxide (GO) by CMC, and the subsequent polymerization of PNIPAm. The presence of rGO in the fabricated PNIPAm/CMC/rGO DN hydrogels enhances the compressibility and flexibility of hydrogels with respect to pure PNIPAm hydrogels, and they exhibit favorable thermoresponsivity, compressibility, and conductivity. The created hydrogels can be continuously cyclically compressed and have excellent bending properties. Furthermore, it was found that the hydrogels are pressure- and temperature-sensitive, and can be applied to the design of both pressure and temperature sensors to detect mechanical deformation and to measure temperature. Our preliminary results suggest that these rGO-based DN hydrogels exhibit a high potential for the fabrication of soft robotics and artificially intelligent skin-like devices.
Indirect Microcontact Printing to Create Functional Patterns of Physisorbed Antibodies
Authors: Juste-Dolz Augusto , Avella-Oliver Miquel , Puchades Rosa , Maquieira Angel
Published: September 2018

Microcontact printing (µCP) is a practical and versatile approach to create nanostructured patterns of biomolecular probes, but it involves conformational changes on the patterned bioreceptors that often lead to a loss on the biological activity of the resulting structures. Herein we introduce indirect µCP to create functional patterns of bioreceptors on solid substrates. This is a simple strategy that relies on physisorbing biomolecular probes of interest in the nanostructured gaps that result after patterning backfilling agents by standard µCP. This study presents the approach, assesses bovine serum albumin as backfilling agent for indirect µCP on different materials, reports the limitations of standard µCP on the functionality of patterned antibodies, and demonstrates the capabilities of indirect µCP to solve this issue. Bioreceptors were herein structured as diffractive gratings and used to measure biorecognition events in label-free conditions. Besides, as a preliminary approach towards sensing biomarkers, this work also reports the implementation of indirect µCP in an immunoassay to detect human immunoglobulin E.
An Invisible Salient Landmark Approach to Locating Pedestrians for Predesigned Business Card Route of Pedestrian Navigation
Authors: Fang Zhixiang , Jiang Yuxin , Xu Hong , Shaw Shih-Lung , Li Ling , Geng Xuexian
Published: September 2018

Visual landmarks are important navigational aids for research into and design of applications for last mile pedestrian navigation, e.g., business card route of pedestrian navigation. The business card route is a route between a fixed origin (e.g., campus entrance) to a fixed destination (e.g., office). The changing characteristics and combinations of various sensors’ data in smartphones or navigation devices can be viewed as invisible salient landmarks for business card route of pedestrian navigation. However, the advantages of these invisible landmarks have not been fully utilized, despite the prevalence of GPS and digital maps. This paper presents an improvement to the Dempster–Shafer theory of evidence to find invisible landmarks along predesigned pedestrian routes, which can guide pedestrians by locating them without using digital maps. This approach is suitable for use as a “business card” route for newcomers to find their last mile destinations smoothly by following precollected sensor data along a target route. Experiments in real pedestrian navigation environments show that our proposed approach can sense the location of pedestrians automatically, both indoors and outdoors, and has smaller positioning errors than purely GPS and Wi-Fi positioning approaches in the study area. Consequently, the proposed methodology is appropriate to guide pedestrians to unfamiliar destinations, such as a room in a building or an exit from a park, with little dependency on geographical information.
Fabrication and Characterization of High-Frequency Ultrasound Transducers Based on Lead-Free BNT-BT Tape-Casting Thick Film
Authors: Zhang Junshan , Ren Wei , Liu Yantao , Wu Xiaoqing , Fei Chunlong , Quan Yi , Zhou Qifa
Published: September 2018

A lead-free 0.94(Na0.5Bi0.5) TiO3-0.06 BaTiO3 (BNT-BT) thick film, with a thickness of 60 μm, has been fabricated using a tape-casting method. The longitudinal piezoelectric constant, clamped dielectric permittivity constant, remnant polarization and coercive field of the BNT-BT thick film were measured to be 150 pC/N, 1928, 13.6 μC/cm2, and 33.6 kV/cm, respectively. The electromechanical coupling coefficient kt was calculated to be 0.55 according to the measured electrical impedance spectrum. A high-frequency plane ultrasound transducer was successfully fabricated using a BNT-BT thick film. The performance of the transducer was characterized and evaluated by the pulse-echo testing and wire phantom imaging operations. The BNT-BT thick film transducer exhibits a center frequency of 34 MHz, a −6 dB bandwidth of 26%, an axial resolution of 77 μm and a lateral resolution of 484 μm. The results suggest that lead-free BNT-BT thick film fabricated by tape-casting method is a promising lead-free candidate for high-frequency ultrasonic transducer applications.
Design of Wideband GHz Electric Field Sensor Integrated with Optical Fiber Transmission Link for Electromagnetic Pulse Signal Measurement
Authors: Zhang Guogang , Li Wenfan , Qi Lu , Liu Jingcun , Song Zhengxiang , Wang Jianhua
Published: September 2018

The detection of high frequency overvoltage and partial discharge is of great significance in evaluating the insulation condition of high-voltage power equipment. A wideband GHz electric field (E-field) sensor for electromagnetic pulse (EMP) signal measurement was proposed in this paper. An optical fiber transmission link was adopted in the design in order to implement high-voltage isolation and reduce electromagnetic interference during transmission. The designed sensor was mainly made up of a differential electric field (D-dot) antenna, transmitter, and receiver. The D-dot antenna was designed to detect high frequency E-field strength and generate a corresponding voltage signal, which was converted into an optical signal by the transmitter. The optical signal could be transmitted a large distance through an optical fiber without electromagnetic interference and changed back to a voltage signal again by a receiver. The design process of the sensor was introduced in detail, and experiments were performed using a gigahertz transverse electromagnetic (GTEM) cell and an EMP simulator to verify it. The results indicated that the designed sensor had a good performance besides an expectable delay due to the optional amplifier.
Path Smoothing Techniques in Robot Navigation: State-of-the-Art, Current and Future Challenges
Authors: Ravankar Abhijeet , Ravankar Ankit A. , Kobayashi Yukinori , Hoshino Yohei , Peng Chao-Chung
Published: September 2018

Robot navigation is an indispensable component of any mobile service robot. Many path planning algorithms generate a path which has many sharp or angular turns. Such paths are not fit for mobile robot as it has to slow down at these sharp turns. These robots could be carrying delicate, dangerous, or precious items and executing these sharp turns may not be feasible kinematically. On the contrary, smooth trajectories are often desired for robot motion and must be generated while considering the static and dynamic obstacles and other constraints like feasible curvature, robot and lane dimensions, and speed. The aim of this paper is to succinctly summarize and review the path smoothing techniques in robot navigation and discuss the challenges and future trends. Both autonomous mobile robots and autonomous vehicles (outdoor robots or self-driving cars) are discussed. The state-of-the-art algorithms are broadly classified into different categories and each approach is introduced briefly with necessary background, merits, and drawbacks. Finally, the paper discusses the current and future challenges in optimal trajectory generation and smoothing research.
The Effects of Exercise Induced Muscle Damage on Knee Joint Torque and Balance Performance
Authors: Dabbs Nicole C. , Chander Harish
Published: September 2018

The purpose of this investigation is to determine the effects of exercise induced muscle damage (EIMD) on balance and knee joint torque. Thirteen males and females volunteered to participate in the study. Following a familiarization session, baseline measures were obtained for isometric torque measured during a maximal voluntary isometric contraction (MVIC) for knee flexors and extensors, and ankle dorsi-flexors and plantar-flexors. Additionally, balance performance was tested in double leg (DL), and right single leg (RSL) static and dynamic unstable stability was measured. Participants then performed the muscle damage protocol of front loaded Bulgarian split squats. All measurements were re-assessed for torque and balance immediately and up to 72 h afterwards. A one-way repeated-measures analysis of variance (ANOVA) was used to analyze differences between baseline and all time-points for torque and balance measures. There was a significant time effect for knee extensors MVIC torque, where baseline measures are greater than post EIMD, 24 h and 48 h post EIMD. There was no significant time effect for all balance conditions. These results provide evidence of EIMD following high intensity eccentric exercises with significant reductions in knee extensor torque up to at least 48 h and show that balance was not compromised following EIMD.
Equal Opportunities in Academic Careers? How Mid-Career Scientists at ETH Zurich Evaluate the Impact of Their Gender and Age
Authors: Hansmann Ralph , Schröter Dagmar
Published: September 2018

Gender equality is essential to social justice and sustainable development in the higher education sector. An important aspect thereof is to promote equal opportunities for academic careers. This study investigates the current situation and possibilities for improvement in this regard from the perspectives of mid-career scientists in a sustainability-oriented university department. A survey of scientists from the postdoctoral to adjunct professor level (N = 82) in the Department of Environmental Systems Science (D-USYS) of ETH Zurich (Swiss Federal Institute of Technology Zurich) was thus conducted to investigate judgements, experiences, and ideas for improvement concerning equal career opportunities. About 90% of the respondents perceived no disadvantages based on gender, ethnicity, race, or faith. However, about 30% felt disadvantaged due to their age. Comments revealed not a single case in which latter disadvantages were based on prejudice. Instead, ETH-wide or national age and time-based restrictions for certain positions caused the inequality perceptions. Furthermore, comments indicated that these restrictions can disadvantage scientists taking care of children. Some participants suggested a revision or removal of corresponding rules. Further suggestions included an improved availability of childcare places. ETH Zurich recently undertook great efforts to provide excellent and affordable childcare services, increasing the number of available places by about 30% in the year following this survey.