bluuebunny/crossref_metadata_2025 huggingface dataset:
Astrocytic IL-6 Influences the Clinical Symptoms of EAE in Mice
Authors: Erta Maria , Giralt Mercedes , Jiménez Silvia , Molinero Amalia , Comes Gemma , Hidalgo Juan
Published: May 2016

Interleukin-6 (IL-6) is a multifunctional cytokine that not only plays major roles in the immune system, but also serves as a coordinator between the nervous and endocrine systems. IL-6 is produced in multiple cell types in the CNS, and in turn, many cells respond to it. It is therefore important to ascertain which cell type is the key responder to IL-6 during both physiological and pathological conditions. In order to test the role of astrocytic IL-6 in neuroinflammation, we studied an extensively-used animal model of multiple sclerosis, experimental autoimmune encephalomyelitis (EAE), in mice with an IL-6 deficiency in astrocytes (Ast-IL-6 KO). Results indicate that lack of astrocytic IL-6 did not cause major changes in EAE symptomatology. However, a delay in the onset of clinical signs was observed in Ast-IL-6 KO females, with fewer inflammatory infiltrates and decreased demyelination and some alterations in gliosis and vasogenesis, compared to floxed mice. These results suggest that astrocyte-secreted IL-6 has some roles in EAE pathogenesis, at least in females.
Rare Earth-Promoted Nickel Oxide Nanoparticles as Catalysts for N2O Direct Decomposition
Authors: Abu-Zied Bahaa , Bawaked Salem , Kosa Samia , Schwieger Wilhelm
Published: May 2016

For this paper, a series of rare earth (Gd, La, Sm) promoted NiO catalysts were prepared by using the microwave-assisted precipitation method and tested for N2O direct decomposition. The obtained solids have been characterized by using various techniques. X-ray diffraction (XRD) results revealed that the incorporation of RE oxides into NiO significantly decreases its crystallite size. Field-emission scanning electron microscopy (SEM) and transmission electron microscopy (TEM) observations indicated that the addition of RE oxides swells the NiO particles yielding particles into a rice-like morphology. N2 adsorption studies showed a sharp surface area increase as well as mesoporosity development accompanied the RE incorporation. It was found that the RE oxides significantly enhance the NiO activity.
Adsorption and Oxidation Investigations over Pt/Al2O3 Catalyst: A Microcalorimetric Study
Authors: Mihai Oana , Creaser Derek , Olsson Louise
Published: May 2016

The differential adsorption heats of oxygen and NO, as well as catalytic oxidation behavior during NO oxidation and NO2 dissociation reactions over supported Pt-catalysts, were investigated by microcalorimetric measurements. The average heat of adsorption (∆H) of oxygen ranged from 310 kJ/mol at 200 °C to 289 kJ/mol at 400 °C. Over this temperature range formation of platinum oxides and coverage dependence caused variations in the apparent heat of adsorption. NO heat of adsorption from 50 to 150 °C was near constant with an average value of 202 kJ/mol over the temperature range.
Facile Synthesis of Vanadium Oxide/Reduced Graphene Oxide Composite Catalysts for Enhanced Hydroxylation of Benzene to Phenol
Authors: Dong Yongli , Niu Xiaoyu , Song Weina , Wang Dong , Chen Liqiang , Yuan Fulong , Zhu Yujun
Published: May 2016

The vanadium oxide/reduced graphene oxide (VOx/RGO) composites have been prepared by a simple solvothermal method with the assistance of cationic surfactant cetyltrimethylammonium bromide (CTAB). The microstructure and morphology of the resultant VOx/RGO composites have been well characterized. The VOx nanoparticles are highly dispersed on the RGO sheets with a particle size of about 25 nm. When used as hydroxylation catalysts, the VOx/RGO composites are more efficient than individual RGO and vanadium oxide catalysts. The enhanced catalytic performance may be related to not only the well dispersed VOx active species, but also the hydrophobic surface and huge π-electron system of RGO for the adsorption and activation of benzene. In addition, the effects of calcination conditions on the microstructure and catalytic properties of VOx/RGO composites have also been investigated. The uniform VOx nanoparticles on the separated RGO sheets show highly efficient catalytic performance, while the formation of aggregated HxV2O5 and bulk V2O5 species along with the destruction of RGO sheets are poor for the hydroxylation of benzene. Up to 17.4% yield of phenol is achieved under the optimized catalytic reaction conditions.
Malaysia’s First Transplanted Case of Chronic Granulomatous Disease: The Journey of Overcoming Obstacles
Authors: Ismail Intan , Jamli Faizah , Othman Ida , Noh Lokman , Abdul Latiff Amir
Published: May 2016

The awareness of primary immunodeficiency (PID) in Malaysia is still not forthcoming. Certain practical issues such as lack of clinical immunologists and specialized laboratory diagnostic facilities remain to be addressed. However, great efforts taken by passionate clinicians and scientists in the immunology networking have ascertained some prevalence. Despite the limitation, all suspected cases of PID are being properly investigated and competently managed. In this case report we highlighted the obstacles we faced in managing PID patients, particularly preparing for bone marrow transplant. This is the first transplanted case of chronic granulomatous disease in Malaysia, which emphasizes the importance of collaborative work to ensure further morbidities or mortalities are prevented.
Disposition of Lightning Activity Due to Pollution Load during Dissimilar Seasons as Observed from Satellite and Ground-Based Data
Authors: Middey Anirban , Kaware Pankaj
Published: May 2016

The precise role of air pollution on the climate and local weather has been an issue for quite a long time. Among the diverse issues, the effects of air pollution on lightning are of recent interest. Exploration over several years (2004 to 2011) has been made over Gangetic West Bengal of India using lightning flash data from TRMM-LIS (Tropical Rainfall Measuring Mission-Lightning Imaging Sensor), atmospheric pollutants, and rainfall data during pre-monsoon (April and May) and monsoon (June, July, August and September) seasons. Near-surface pollutants such as PM10 and SO2 have a good positive association with aerosol optical depth (AOD) for both the pre-monsoon and monsoon months. High atmospheric aerosol loading correlates well with pre-monsoon and monsoon lightning flashes. However, rainfall has a dissimilar effect on lightning flashes. Flash count is positively associated with pre-monsoon rainfall (r = 0.64), but the reverse relation (r = −0.4) is observed for monsoon rainfall. Apart from meteorological factors, wet deposition of atmospheric pollutant may be considered a crucial factor for decreased lightning flash count in monsoon. The variation in the monthly average tropospheric column amount of NO2, from the Tropospheric Emission Monitoring Internet Service (TEMIS), is synchronic with average lightning flash rate. It has a good linear association with flash count for both pre-monsoon and monsoon seasons. The effect of lightning on tropospheric NO2 production is evident from the monthly average variation in NO2 on lightning and non-lightning days.
Improving the Sensitivity and Functionality of Mobile Webcam-Based Fluorescence Detectors for Point-of-Care Diagnostics in Global Health
Authors: Rasooly Reuven , Bruck Hugh , Balsam Joshua , Prickril Ben , Ossandon Miguel , Rasooly Avraham
Published: May 2016

Resource-poor countries and regions require effective, low-cost diagnostic devices for accurate identification and diagnosis of health conditions. Optical detection technologies used for many types of biological and clinical analysis can play a significant role in addressing this need, but must be sufficiently affordable and portable for use in global health settings. Most current clinical optical imaging technologies are accurate and sensitive, but also expensive and difficult to adapt for use in these settings. These challenges can be mitigated by taking advantage of affordable consumer electronics mobile devices such as webcams, mobile phones, charge-coupled device (CCD) cameras, lasers, and LEDs. Low-cost, portable multi-wavelength fluorescence plate readers have been developed for many applications including detection of microbial toxins such as C. Botulinum A neurotoxin, Shiga toxin, and S. aureus enterotoxin B (SEB), and flow cytometry has been used to detect very low cell concentrations. However, the relatively low sensitivities of these devices limit their clinical utility. We have developed several approaches to improve their sensitivity presented here for webcam based fluorescence detectors, including (1) image stacking to improve signal-to-noise ratios; (2) lasers to enable fluorescence excitation for flow cytometry; and (3) streak imaging to capture the trajectory of a single cell, enabling imaging sensors with high noise levels to detect rare cell events. These approaches can also help to overcome some of the limitations of other low-cost optical detection technologies such as CCD or phone-based detectors (like high noise levels or low sensitivities), and provide for their use in low-cost medical diagnostics in resource-poor settings.
A Software Framework for Rapid Application-Specific Hybrid Photonic Network-on-Chip Synthesis
Authors: Bahirat Shirish , Pasricha Sudeep
Published: May 2016

Network on Chip (NoC) architectures have emerged in recent years as scalable communication fabrics to enable high bandwidth data transfers in chip multiprocessors (CMPs). These interconnection architectures still need to conquer many challenges, e.g., significant power consumption and high data transfer latencies. Hybrid electro-photonic NoCs have been recently proposed as a solution to mitigate some of these challenges. However, with increasing application complexity, hardware dependencies, and performance variability, optimization of hybrid photonic NoCs requires traversing a massive design space. To date, prior work on software tools for rapid automated NoC synthesis have mainly focused on electrical NoCs. In this article, we propose a novel suite of software tools for effectively synthesizing hybrid photonic NoCs. We formulate and solve the synthesis problem using four search-based optimization heuristics: (1) Ant Colony Optimization (ACO); (2) Particle Swarm Optimization (PSO); (3) Genetic Algorithm (GA); and (4) Simulated Annealing (SA). Our experimental results show significant promise for the ACO and PSO based heuristics. Our novel implementation of PSO achieves an average of 64% energy-delay product improvements over GA and 53% improvement over SA; while our novel ACO implementation achieves 107% energy-delay product improvements over GA and 62% improvement over SA.
Assessment of the Variability of Biogas Production from Sugar Beet Silage as Affected by Movement and Loss of the Produced Alcohols and Organic Acids
Authors: Heidarzadeh Vazifehkhoran Ali , Triolo Jin , Larsen Søren , Stefanek Kasper , Sommer Sven
Published: May 2016

The biochemical methane potential and composition of sugar beet pulp silage were investigated using samples taken from six different depths in both open and closed silos (height 3.6 m). The biochemical methane potential (BMP) of pulp silage in open silos ranged from 337 to 420 normal litre (NL) CH4/kg volatile solids (VS), while the BMP of pulp silage in closed silos varied between 411 and 451 NL CH4/kg VS. The biochemical methane potential peaked at a depth of 1.45 m with 420 NL CH4/kg VS for open silos and 451 NL CH4/kg VS for closed silos. The ethanol concentration and biochemical methane potential showed the same trend with depth throughout the silos. The energy loss correlated to the loss of volatile solids, and the depths described a linear relationship between them for both the open and closed silos (R2 = 0.997 for the open silo and R2 = 0.991 for the closed silo). The energy potentials and composition of beet pulp silage were highly stratified and there was a risk that the silage samples were not representative in investigations of biomass quality for energy production.
Telecommunication Technologies for Smart Grid Projects with Focus on Smart Metering Applications
Authors: Andreadou Nikoleta , Guardiola Miguel , Fulli Gianluca
Published: May 2016

This paper provides a study of the smart grid projects realised in Europe and presents their technological solutions with a focus on smart metering Low Voltage (LV) applications. Special attention is given to the telecommunications technologies used. For this purpose, we present the telecommunication technologies chosen by several European utilities for the accomplishment of their smart meter national roll-outs. Further on, a study is performed based on the European Smart Grid Projects, highlighting their technological options. The range of the projects analysed covers the ones including smart metering implementation as well as those in which smart metering applications play a significant role in the overall project success. The survey reveals that various topics are directly or indirectly linked to smart metering applications, like smart home/building, energy management, grid monitoring and integration of Renewable Energy Sources (RES). Therefore, the technological options that lie behind such projects are pointed out. For reasons of completeness, we also present the main characteristics of the telecommunication technologies that are found to be used in practice for the LV grid.
Fabrication and Characterization of CH3NH3PbI3−x−yBrxCly Perovskite Solar Cells
Authors: Suzuki Atsushi , Okada Hiroshi , Oku Takeo
Published: May 2016

Fabrication and characterization of CH3NH3PbI3−x−yBrxCly perovskite solar cells using mesoporous TiO2 as electron transporting layer and 2,2′,7,7′-tetrakis-(N,N-di-4-methoxyphenylamino)-9,9′-spirobifluorene as a hole-transporting layer (HTL) were performed. The purpose of the present study is to investigate role of halogen doping using iodine (I), bromine (Br) and chlorine (Cl) compounds as dopant on the photovoltaic performance and microstructures of CH3NH3PbI3−x−yBrxCly perovskite solar cells. The X-ray diffraction identified a slight decrease of crystal spacing in the perovskite crystal structure doped with a small amount of I, Br, and Cl in the perovskite compounds. Scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX) showed the perovskite crystal behavior depended on molar ratio of halogen of Pb, I, Br and Cl. Incorporation of the halogen doping into the perovskite crystal structure improved photo generation, carrier diffusion without carrier recombination in the perovskite layer and optimization of electronic structure related with the photovoltaic parameters of open-circuit voltage, short-circuit current density and conversion efficiency. The energy diagram and photovoltaic mechanisms of the perovskite solar cells were discussed in the context of the experimental results.
Transcriptome-Wide Survey and Expression Profile Analysis of Putative Chrysanthemum HD-Zip I and II Genes
Authors: Song Aiping , Li Peiling , Xin Jingjing , Chen Sumei , Zhao Kunkun , Wu Dan , Fan Qingqing , Gao Tianwei , Chen Fadi , Guan Zhiyong
Published: May 2016

The homeodomain-leucine zipper (HD-Zip) transcription factor family is a key transcription factor family and unique to the plant kingdom. It consists of a homeodomain and a leucine zipper that serve in combination as a dimerization motif. The family can be classified into four subfamilies, and these subfamilies participate in the development of hormones and mediation of hormone action and are involved in plant responses to environmental conditions. However, limited information on this gene family is available for the important chrysanthemum ornamental species (Chrysanthemum morifolium). Here, we characterized 17 chrysanthemum HD-Zip genes based on transcriptome sequences. Phylogenetic analyses revealed that 17 CmHB genes were distributed in the HD-Zip subfamilies I and II and identified two pairs of putative orthologous proteins in Arabidopsis and chrysanthemum and four pairs of paralogous proteins in chrysanthemum. The software MEME was used to identify 7 putative motifs with E values less than 1e-3 in the chrysanthemum HD-Zip factors, and they can be clearly classified into two groups based on the composition of the motifs. A bioinformatics analysis predicted that 8 CmHB genes could be targeted by 10 miRNA families, and the expression of these 17 genes in response to phytohormone treatments and abiotic stresses was characterized. The results presented here will promote research on the various functions of the HD-Zip gene family members in plant hormones and stress responses.
Nonylphenol Toxicity Evaluation and Discovery of Biomarkers in Rat Urine by a Metabolomics Strategy through HPLC-QTOF-MS
Authors: Zhang Yan-Xin , Yang Xin , Zou Pan , Du Peng-Fei , Wang Jing , Jin Fen , Jin Mao-Jun , She Yong-Xin
Published: May 2016

Nonylphenol (NP) was quantified using liquid chromatography tandem mass spectrometry (LC-MS/MS) in the urine and plasma of rats treated with 0, 50, and 250 mg/kg/day of NP for four consecutive days. A urinary metabolomic strategy was originally implemented by high performance liquid chromatography time of flight mass spectrometry (HPLC-QTOF-MS) to explore the toxicological effects of NP and determine the overall alterations in the metabolite profiles so as to find potential biomarkers. It is essential to point out that from the observation, the metabolic data were clearly clustered and separated for the three groups. To further identify differentiated metabolites, multivariate analysis, including principal component analysis (PCA), orthogonal partial least-squares discriminant analysis (OPLS-DA), high-resolution MS/MS analysis, as well as searches of Metlin and Massbank databases, were conducted on a series of metabolites between the control and dose groups. Finally, five metabolites, including glycine, glycerophosphocholine, 5-hydroxytryptamine, malonaldehyde (showing an upward trend), and tryptophan (showing a downward trend), were identified as the potential urinary biomarkers of NP-induced toxicity. In order to validate the reliability of these potential biomarkers, an independent validation was performed by using the multiple reaction monitoring (MRM)-based targeted approach. The oxidative stress reflected by urinary 8-oxo-deoxyguanosine (8-oxodG) levels was elevated in individuals highly exposed to NP, supporting the hypothesis that mitochondrial dysfunction was a result of xenoestrogen accumulation. This study reveals a promising approach to find biomarkers to assist researchers in monitoring NP.
Boiling over: A Descriptive Analysis of Drinking Water Advisories in First Nations Communities in Ontario, Canada
Authors: Galway Lindsay
Published: May 2016

Access to safe and reliable drinking water is commonplace for most Canadians. However, the right to safe and reliable drinking water is denied to many First Nations peoples across the country, highlighting a priority public health and environmental justice issue in Canada. This paper describes trends and characteristics of drinking water advisories, used as a proxy for reliable access to safe drinking water, among First Nations communities in the province of Ontario. Visual and statistical tools were used to summarize the advisory data in general, temporal trends, and characteristics of the drinking water systems in which advisories were issued. Overall, 402 advisories were issued during the study period. The number of advisories increased from 25 in 2004 to 75 in 2013. The average advisory duration was 294 days. Most advisories were reported in summer months and equipment malfunction was the most commonly reported reason for issuing an advisory. Nearly half of all advisories occurred in drinking water systems where additional operator training was needed. These findings underscore that the prevalence of drinking water advisories in First Nations communities is a problem that must be addressed. Concerted and multi-faceted efforts are called for to improve the provision of safe and reliable drinking water First Nations communities.
Assessment on the Impact of Arable Land Protection Policies in a Rapidly Developing Region
Authors: Li Jiadan , Zhang Zhongchu , Ma Ligang , Gu Qing , Wang Ke , Xu Zhihao
Published: May 2016

To investigate the effect of arable land protection policies in China, a practical framework that integrates geographic information systems (GIS), soil quality assessment and landscape metrics analysis was employed to track and analyze arable land transformations and landscape changes in response to rampant urbanization within the Ningbo region (China) from 2005 to 2013. The results showed that arable land loss and degradation have continued, despite the development of a comprehensive legal framework for arable land protection. The implementation of arable land protection policies is judged to be effective, but not entirely successful, because it guarantees the overall amount of arable land but does not consider soil quality and spatial distribution. In addition, there are distinct variations in arable land change dynamics between two temporal intervals. From 2005–2009, the transformation of arable land was diversified, with intensified conversion among arable land, built-up land, water and orchards. Moreover, many new arable land parcels were adjacent to built-up land, and are in danger of being occupied again through urban sprawl. By 2009–2013, most of the arable land was occupied by urban expansion, whereas a majority of newly increased arable land was reclaimed from coastal tideland. Although the newly increased arable land was contiguous and far from the urban area, it is of poor quality and has limited use. The permanent loss of high-quality arable land due to intensified urban sprawl may threaten sustainable development and food security on a larger scale.
A Knowledge-Based Step Length Estimation Method Based on Fuzzy Logic and Multi-Sensor Fusion Algorithms for a Pedestrian Dead Reckoning System
Authors: Lai Ying-Chih , Chang Chin-Chia , Tsai Chia-Ming , Huang Shih-Ching , Chiang Kai-Wei
Published: May 2016

The demand for pedestrian navigation has increased along with the rapid progress in mobile and wearable devices. This study develops an accurate and usable Step Length Estimation (SLE) method for a Pedestrian Dead Reckoning (PDR) system with features including a wide range of step lengths, a self-contained system, and real-time computing, based on the multi-sensor fusion and Fuzzy Logic (FL) algorithms. The wide-range SLE developed in this study was achieved by using a knowledge-based method to model the walking patterns of the user. The input variables of the FL are step strength and frequency, and the output is the estimated step length. Moreover, a waist-mounted sensor module has been developed using low-cost inertial sensors. Since low-cost sensors suffer from various errors, a calibration procedure has been utilized to improve accuracy. The proposed PDR scheme in this study demonstrates its ability to be implemented on waist-mounted devices in real time and is suitable for the indoor and outdoor environments considered in this study without the need for map information or any pre-installed infrastructure. The experiment results show that the maximum distance error was within 1.2% of 116.51 m in an indoor environment and was 1.78% of 385.2 m in an outdoor environment.
Effect of AQP9 Expression in Androgen-Independent Prostate Cancer Cell PC3
Authors: Chen Qiwei , Zhu Liang , Zheng Bo , Wang Jinliang , Song Xishuang , Zheng Wei , Wang Lina , Yang Deyong , Wang Jianbo
Published: May 2016

It is known that aquaporin 9 (AQP9) in the prostate was strictly upregulated by androgen and may represent a novel therapeutic target for several cancers, but whether AQP9 plays a role in the regulation of androgen-independent prostate cancer still remains unclear. In the present study, AQP9 was determined in prostate cancer and adjacent cancer tissues; AQP9-siRNA was applied to silencing AQP9 in androgen-independent prostate cancer cell PC3 cell line. Western blot and flow cytometry analysis were employed to detect changes in related-function of control and AQP9-siRNA groups. The results showed that AQP9 is significantly induced in cancer tissues than that in adjacent cancer tissues. Moreover, knockdown of AQP9 in PC3 androgen-independent prostate cancer cell prostate cancer cells increased inhibition rates of proliferation. In addition, knockdown of AQP9 resulted in a significant decrease in the expression of the Bcl-2 and with a notable increase in the expression of Bax and cleaved caspase 3, indicated that AQP9 knockdown promoted apoptosis in prostate cancer cells. From wound healing assay and matrigel invasion, we suggested that AQP9 expression affects the motility and invasiveness of prostate cancer cells. Moreover, In order to explore the pathway may be involved in AQP9-mediated motility and invasion of prostate cancer cells, the phosphorylation of ERK1/2 was significant suppressed in AQP9 siRNA-transfected cells compared with that in control cells, suggesting that AQP9 is involved in the activation of the ERK pathway in androgen-independent prostate cancer cells.
β,β-Isomer of Open-Wells–Dawson Polyoxometalate Containing a Tetra-Iron(III) Hydroxide Cluster: [{Fe4(H2O)(OH)5}(β,β-Si2W18O66)]9−
Authors: Matsunaga Satoshi , Miyamae Eriko , Inoue Yusuke , Nomiya Kenji
Published: May 2016

The β,β-isomer of open-Wells–Dawson polyoxometalate (POM) containing a tetra-iron(III) cluster, K9[{Fe4(H2O)(OH)5}(β,β-Si2W18O66)]·17H2O (potassium salt of β,β-Fe4-open), was synthesized by reacting Na9H[A-β-SiW9O34]·23H2O with FeCl3·6H2O at pH 3, and characterized by X-ray crystallography, FTIR, elemental analysis, TG/DTA, UV–Vis, and cyclic voltammetry. X-ray crystallography revealed that the {Fe3+4(H2O)(OH)5}7+ cluster was included in the open pocket of the β,β-type open-Wells–Dawson polyanion [β,β-Si2W18O66]16− formed by the fusion of two trilacunary β-Keggin POMs, [A-β-SiW9O34]10−, via two W–O–W bonds. The β,β-open-Wells–Dawson polyanion corresponds to an open structure of the standard γ-Wells–Dawson POM. β,β-Fe4-open is the first example of the compound containing a geometrical isomer of α,α-open-Wells–Dawson structural POM.
A Word of Caution: Human Rights, Disability, and Implementation of the Post-2015 Sustainable Development Goals
Authors: Brolan Claire
Published: May 2016

On 25 September 2015, the United Nations (UN) General Assembly unanimously voted for the post-2015 UN resolution on the post-2015 Sustainable Development Goal (SDG) agenda. This article argues that although the post-2015 SDG agenda is an advance on its precursor the Millennium Development Goals (MDGs)—especially for progressing the human rights of persons with disabilities in development settings, everywhere—it should nonetheless be approached with caution. This article will identify “three steps forward” for persons with disabilities within the broad content of the post-2015 SDGs, while also highlighting four potential “steps back”. It concludes persons with disabilities, disability rights advocates and their supporters must remain vigilant as the post-SDG UN resolution is now operationalised and implemented by UN Member States and their many partners. This is particularly so if the content of the Convention on the Rights of Persons with Disabilities is to be effectively integrated into the post-2015 development policy and planning landscape.
6-Nitro-4H-benzo[d][1,3]thiazin-2-amine
Authors: Gnanasekaran Krishna , Hiett John , Bunce Richard
Published: May 2016

An efficient and cost-effective synthesis of 6-nitro-4H-benzo[d][1,3]thiazin-2-amine based on a sequential SN2-SNAr process is reported. The synthesis is accomplished with an overall yield of 80%.
Fatigue Damage Monitoring of a Composite Step Lap Joint Using Distributed Optical Fibre Sensors
Authors: Wong Leslie , Chowdhury Nabil , Wang John , Chiu Wing , Kodikara Jayantha
Published: May 2016

Over the past few decades, there has been a considerable interest in the use of distributed optical fibre sensors (DOFS) for structural health monitoring of composite structures. In aerospace-related work, health monitoring of the adhesive joints of composites has become more significant, as they can suffer from cracking and delamination, which can have a significant impact on the integrity of the joint. In this paper, a swept-wavelength interferometry (SWI) based DOFS technique is used to monitor the fatigue in a flush step lap joint composite structure. The presented results will show the potential application of distributed optical fibre sensor for damage detection, as well as monitoring the fatigue crack growth along the bondline of a step lap joint composite structure. The results confirmed that a distributed optical fibre sensor is able to enhance the detection of localised damage in a structure.
Formation of Aluminum Particles with Shell Morphology during Pressureless Spark Plasma Sintering of Fe–Al Mixtures: Current-Related or Kirkendall Effect?
Authors: Dudina Dina , Bokhonov Boris , Mukherjee Amiya
Published: May 2016

A need to deeper understand the influence of electric current on the structure and properties of metallic materials consolidated by Spark Plasma Sintering (SPS) stimulates research on inter-particle interactions, bonding and necking processes in low-pressure or pressureless conditions as favoring technique-specific local effects when electric current passes through the underdeveloped inter-particle contacts. Until now, inter-particle interactions during pressureless SPS have been studied mainly for particles of the same material. In this work, we focused on the interactions between particles of dissimilar materials in mixtures of micrometer-sized Fe and Al powders forming porous compacts during pressureless SPS at 500–650 °C. Due to the chemical interaction between Al and Fe, necks of conventional shape did not form between the dissimilar particles. At the early interaction stages, the Al particles acquired shell morphology. It was shown that this morphology change was not related to the influence of electric current but was due to the Kirkendall effect in the Fe–Al system and particle rearrangement in a porous compact. No experimental evidence of melting or melt ejection during pressureless SPS of the Fe–Al mixtures or Fe and Al powders sintered separately was observed. Porous FeAl-based compacts could be obtained from Fe-40at.%Al mixtures by pressureless SPS at 650 °C.
Stress Wave Propagation in Viscoelastic-Plastic Rock-Like Materials
Authors: Lang Liu , Song KI-IL , Zhai Yue , Lao Dezheng , Lee Hang-Lo
Published: May 2016

Rock-like materials are composites that can be regarded as a mixture composed of elastic, plastic, and viscous components. They exhibit viscoelastic-plastic behavior under a high-strain-rate loading according to element model theory. This paper presents an analytical solution for stress wave propagation in viscoelastic-plastic rock-like materials under a high-strain-rate loading and verifies the solution through an experimental test. A constitutive equation of viscoelastic-plastic rock-like materials was first established, and then kinematic and kinetic equations were then solved to derive the analytic solution for stress wave propagation in viscoelastic-plastic rock-like materials. An experimental test using the SHPB (Split Hopkinson Pressure Bar) for a concrete specimen was conducted to obtain a stress-strain curve under a high-strain-rate loading. Inverse analysis based on differential evolution was conducted to estimate undetermined variables for constitutive equations. Finally, the relationship between the attenuation factor and the strain rate in viscoelastic-plastic rock-like materials was investigated. According to the results, the frequency of the stress wave, viscosity coefficient, modulus of elasticity, and density play dominant roles in the attenuation of the stress wave. The attenuation decreases with increasing strain rate, demonstrating strongly strain-dependent attenuation in viscoelastic-plastic rock-like materials.
Microstructural Anisotropy of Magnetocaloric Gadolinium Cylinders: Effect on the Mechanical Properties of the Material
Authors: Petrovič Darja , Šturm Roman , Naglič Iztok , Markoli Boštjan , Pepelnjak Tomaž
Published: May 2016

The development of advanced materials and technologies based on magnetocaloric Gd and its compounds requires an understanding of the dependency of mechanical properties on their underlying microstructure. Therefore, the aim of the study was to characterize microstructural inhomogeneities in the gadolinium that can be used in magnetocaloric refrigeration systems. Microstructures of magnetocaloric gadolinium cylinders were investigated by light microscopy and FE-SEM (Field Emission Scanning Electron Microscopy), EDS (Energy-dispersive X-ray Spectroscopy), and BSE (Back-scattered Electrons) in both the extrusion and the extrusion-transversal directions. XRD (X-ray Diffraction) analyses were performed to reveal the presence of calcium- and fluorine-based compounds. Metallographic characterization showed an oxidized and inhomogeneous microstructure of the cross-sections. The edges and the outer parts of the cylinders were oxidized more intensively on the surfaces directly exposed to the processing tools. Moreover, a significant morphological anisotropy of the non-metallic inclusions was observed. CaF inclusions act as active nucleation sites for internal oxidation. The non-metallic, Ca- and F-containing inclusions can be classified as complex calciumoxyfluorides. The solubility of Er and Yb in the CaF was negligible compared to the Gd matrix and/or the oxide phase. Lower mechanical properties of the material are a consequence of the lower structural integrity due to selective oxidation of surfaces and interfaces.
Fabrication of a Delaying Biodegradable Magnesium Alloy-Based Esophageal Stent via Coating Elastic Polymer
Authors: Yuan Tianwen , Yu Jia , Cao Jun , Gao Fei , Zhu Yueqi , Cheng Yingsheng , Cui Wenguo
Published: May 2016

Esophageal stent implantation can relieve esophageal stenosis and obstructions in benign esophageal strictures, and magnesium alloy stents are a good candidate because of biodegradation and biological safety. However, biodegradable esophageal stents show a poor corrosion resistance and a quick loss of mechanical support in vivo. In this study, we chose the elastic and biodegradable mixed polymer of Poly(ε-caprolactone) (PCL) and poly(trimethylene carbonate) (PTMC) as the coated membrane on magnesium alloy stents for fabricating a fully biodegradable esophageal stent, which showed an ability to delay the degradation time and maintain mechanical performance in the long term. After 48 repeated compressions, the mechanical testing demonstrated that the PCL-PTMC-coated magnesium stents possess good flexibility and elasticity, and could provide enough support against lesion compression when used in vivo. According to the in vitro degradation evaluation, the PCL-PTMC membrane coated on magnesium was a good material combination for biodegradable stents. During the in vivo evaluation, the proliferation of the smooth muscle cells showed no signs of cell toxicity. Histological examination revealed the inflammation scores at four weeks in the magnesium-(PCL-PTMC) stent group were similar to those in the control group (p > 0.05). The α-smooth muscle actin layer in the media was thinner in the magnesium-(PCL-PTMC) stent group than in the control group (p < 0.05). Both the epithelial and smooth muscle cell layers were significantly thinner in the magnesium-(PCL-PTMC) stent group than in the control group. The stent insertion was feasible and provided reliable support for at least four weeks, without causing severe injury or collagen deposition. Thus, this stent provides a new stent for the treatment of benign esophageal stricture and a novel research path in the development of temporary stents in other cases of benign stricture.
Controlled Bulk Properties of Composite Polymeric Solutions for Extensive Structural Order of Honeycomb Polysulfone Membranes
Authors: Gugliuzza Annarosa , Perrotta Maria , Drioli Enrico
Published: May 2016

This work provides additional insights into the identification of operating conditions necessary to overcome a current limitation to the scale-up of the breath figure method, which is regarded as an outstanding manufacturing approach for structurally ordered porous films. The major restriction concerns, indeed, uncontrolled touching droplets at the boundary. Herein, the bulk of polymeric solutions are properly managed to generate honeycomb membranes with a long-range structurally ordered texture. Water uptake and dynamics are explored as chemical environments are changed with the intent to modify the hydrophilic/hydrophobic balance and local water floatation. In this context, a model surfactant such as the polyoxyethylene sorbitan monolaurate is used in combination with alcohols at different chain length extents and a traditional polymer such as the polyethersufone. Changes in the interfacial tension and kinematic viscosity taking place in the bulk of composite solutions are explored and examined in relation to competitive droplet nucleation and growth rate. As a result, extensive structurally ordered honeycomb textures are obtained with the rising content of the surfactant while a broad range of well-sized pores is targeted as a function of the hydrophilic-hydrophobic balance and viscosity of the composite polymeric mixture. The experimental findings confirm the consistency of the approach and are expected to give propulsion to the commercially production of breath figures films shortly.
Tensile Fracture Behavior of Progressively-Drawn Pearlitic Steels
Authors: Toribio Jesús , Ayaso Francisco-Javier , González Beatriz , Matos Juan-Carlos , Vergara Diego , Lorenzo Miguel
Published: May 2016

In this paper a study is presented of the tensile fracture behavior of progressively-drawn pearlitic steels obtained from five different cold-drawing chains, including each drawing step from the initial hot-rolled bar (not cold-drawn at all) to the final commercial product (pre-stressing steel wire). To this end, samples of the different wires were tested up to fracture by means of standard tension tests, and later, all of the fracture surfaces were analyzed by scanning electron microscopy (SEM). Micro-fracture maps (MFMs) were assembled to characterize the different fractographic modes and to study their evolution with the level of cumulative plastic strain during cold drawing.
Hard Copper with Good Electrical Conductivity Fabricated by Accumulative Roll-Bonding to Ultrahigh Strains
Authors: Yao Gongcheng , Mei Qingsong , Li Juying , Li Congling , Ma Ye , Chen Feng , Zhang Guodong , Yang Bing
Published: May 2016

By modifying the accumulative roll-bonding (ARB) procedures, accumulative roll-bonding (ARB) processing up to 30 cycles (N) with a 50% thickness reduction per cycle (equivalent strain = 24) at room temperature was conducted on pure copper. The bonding condition, microhardness and electrical conductivity of the ARBed Cu were studied. Results showed that good bonding condition of the samples was achieved. As N increases, the microhardness of ARBed Cu increases, reaching ~2.9 times that of annealed Cu for N = 30. The electrical conductivity of ARBed Cu decreases slightly but with periodic fluctuations for N > 10, with a minimum of 90.4% IACS for N = 30. Our study indicated that ARB can be an effective way to produce high-hardness and high-conductivity pure copper better than or comparable to Cu alloys and Cu based composites as reported.
Enhanced Mechanical Properties of MgZnCa Bulk Metallic Glass Composites with Ti-Particle Dispersion
Authors: Wong Pei , Lee Tsung , Tsai Pei , Cheng Cheng , Li Chuan , Jang Jason , Huang J.
Published: May 2016

Rod samples of Mg60Zn35Ca5 bulk metallic glass composites (BMGCs) dispersed with Ti particles have been successfully fabricated via injection casting. The glass forming ability (GFA) and the mechanical properties of these Mg-based BMGCs have been systematically investigated as a function of the volume fraction (Vf) of Ti particles. The results showed that the compressive ductility increased with Vf. The mechanical performance of these BMGCs, with up to 5.4% compressive failure strain and 1187 MPa fracture strength at room temperature, can be obtained for the Mg-based BMGCs with 50 vol % Ti particles, suggesting that these dispersed Ti particles can absorb the energy of the crack propagations and can induce branches of the primary shear band into multiple secondary shear bands. It follows that further propagation of the shear band is blocked, enhancing the overall plasticity.
Low-Cost BD/MEMS Tightly-Coupled Pedestrian Navigation Algorithm
Authors: Lin Tianyu , Zhang Zhenyuan , Tian Zengshan , Zhou Mu
Published: May 2016

Pedestrian Dead Reckoning (PDR) by combining the Inertial Measurement Unit (IMU) and magnetometer is an independent navigation approach based on multiple sensors. Since the inertial component error is significantly determined by the parameters of navigation equations, the navigation precision may deteriorate with time, which is inappropriate for long-time navigation. Although the BeiDou (BD) navigation system can provide high navigation precision in most scenarios, the signal from satellites is easily degraded because of buildings or thick foliage. To solve this problem, a tightly-coupled BD/MEMS (Micro-Electro-Mechanical Systems) integration algorithm is proposed in this paper, and a prototype was built for implementing the integrated system. The extensive experiments prove that the BD/MEMS system performs well in different environments, such as an open sky environment and a playground surrounded by trees and thick foliage. The proposed algorithm is able to provide continuous and reliable positioning service for pedestrian outdoors and thereby has wide practical application.
Clay Mineralogy of Coal-Hosted Nb-Zr-REE-Ga Mineralized Beds from Late Permian Strata, Eastern Yunnan, SW China: Implications for Paleotemperature and Origin of the Micro-Quartz
Authors: Zhao Lixin , Dai Shifeng , Graham Ian , Wang Peipei
Published: May 2016

The clay mineralogy of pyroclastic Nb(Ta)-Zr(Hf)-REE-Ga mineralization in Late Permian coal-bearing strata from eastern Yunnan Province; southwest China was investigated in this study. Samples from XW and LK drill holes in this area were analyzed using XRD (X-ray diffraction) and SEM (scanning electronic microscope). Results show that clay minerals in the Nb-Zr-REE-Ga mineralized samples are composed of mixed layer illite/smectite (I/S); kaolinite and berthierine. I/S is the major component among the clay assemblages. The source volcanic ashes controlled the modes of occurrence of the clay minerals. Volcanic ash-originated kaolinite and berthierine occur as vermicular and angular particles, respectively. I/S is confined to the matrix and is derived from illitization of smectite which was derived from the original volcanic ashes. Other types of clay minerals including I/S and berthierine precipitated from hydrothermal solutions were found within plant cells; and coexisting with angular berthierine and vermicular kaolinite. Inferred from the fact that most of the I/S is R1 ordered with one case of the R3 I/S; the paleo-diagenetic temperature could be up to 180 °C but mostly 100–160 °C. The micro-crystalline quartz grains (<10 µm) closely associated with I/S were observed under SEM and were most likely the product of desiliconization during illitization of smectite.
Characterization of the Principal Constituents of Danning Tablets, a Chinese Formula Consisting of Seven Herbs, by an UPLC-DAD-MS/MS Approach
Authors: Zhan Changsen , Xiong Aizhen , Shen Danping , Yang Li , Wang Zhengtao
Published: May 2016

Danning Tablets are a traditional Chinese formula showing broad clinical applications in hepatobiliary diseases and containing a diversity of bioactive chemicals. However, the chemical profiling of the formula, which serves as the material foundation of its efficacy, is really a big challenge as Danning Tablets consist of seven herbs from different origins. An ultra-performance liquid chromatography coupled to diode array detection and electrospray ionization mass spectrometry (UPLC-DAD-ESI-MS/MS) approach was developed to characterize the principal polyphenol constituents in the formula. As a result, a total of 32 constituents, including 14 anthraquinones and their glucosides, four anthrones, two naphthalene glycosides, two stilbenes and 10 flavonoids were identified based on their retention time, UV absorption and MS/MS fragmentation patterns. The sources of these compounds were also illustrated. Most of the bioactive anthraquinone derivatives were found in Rhei Radix et Rhizoma or Polygoni Cuspidati Rhizoma et Radix, which are the Emperor drugs in the formula for its clinic usage. These findings indicate the merit of using this integrated UPLC-DAD-ESI-MS/MS approach to rapidly illustrate the chemical foundation of complex formulas. The present study will facilitate the quality control of Danning Tablet formulas as well as the individual herbs.
Synthesis and Biological Evaluation of Benzochromenopyrimidinones as Cholinesterase Inhibitors and Potent Antioxidant, Non-Hepatotoxic Agents for Alzheimer’s Disease
Authors: Dgachi Youssef , Bautista-Aguilera Oscar , Benchekroun Mohamed , Martin Hélène , Bonet Alexandre , Knez Damijan , Godyń Justyna , Malawska Barbara , Gobec Stanislav , Chioua Mourad , Janockova Jana , Soukup Ondrej , Chabchoub Fakher , Marco-Contelles José , Ismaili Lhassane
Published: May 2016

We report herein the straightforward two-step synthesis and biological assessment of novel racemic benzochromenopyrimidinones as non-hepatotoxic, acetylcholinesterase inhibitors with antioxidative properties. Among them, compound 3Bb displayed a mixed-type inhibition of human acetylcholinesterase (IC50 = 1.28 ± 0.03 μM), good antioxidant activity, and also proved to be non-hepatotoxic on human HepG2 cell line.
In Vitro Antioxidant, Anti-Diabetes, Anti-Dementia, and Inflammation Inhibitory Effect of Trametes pubescens Fruiting Body Extracts
Authors: Im Kyung , Nguyen Trung , Choi Jaehyuk , Lee Tae
Published: May 2016

Trametes pubescens, white rot fungus, has been used for folk medicine in Asian countries to treat ailments such as cancer and gastrointestinal diseases. This study was initiated to evaluate the in vitro antioxidant, anti-diabetes, anti-dementia, and anti-inflammatory activities of T. pubescens fruiting bodies. The 1,1-diphenyl-2-picryl-hydrazyl (DPPH) free radical scavenging activities of T. pubescens methanol (ME) and hot water (HWE) extracts (2.0 mg/mL) were comparable to butylated hydroxytoluene (BHT), the positive control. However, the chelating effects of ME and HWE were significantly higher than that of BHT. The HWE (6 mg/mL) also showed comparable reducing power to BHT. Eleven phenol compounds were detected by high performance liquid chromatography (HPLC) analysis. The α-amylase and α-glucosidase inhibitory activities of the ME and HWE of the mushroom were lower than Acarbose, the standard reference; however, the inhibitory effects of the mushroom extracts at 2.0 mg/mL were moderate. The acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory effects of ME and HWE were moderate and comparable with galanthamine, the standard drug to treat early stages of Alzheimer’s disease (AD). The ME had a neuroprotective effect against glutamate-induced PC-12 cell cytotoxicity at the concentration range of 2–40 μg/mL. The mushroom extracts also showed inflammation inhibitory activities such as production of nitric oxide (NO) and expression of inducible nitric oxide synthase (iNOS) in lipopolysaccharide (LPS)-induced murine macrophage-like cell lines (RAW 264.7) and significantly suppressed the carrageenan-induced rat paw-edema. Therefore, fruiting body extracts of T. pubescens demonstrated antioxidant related anti-diabetes, anti-dementia and anti-inflammatory activities.