bluuebunny/crossref_metadata_2025 huggingface dataset:
HSFA2 Functions in the Physiological Adaptation of Undifferentiated Plant Cells to Spaceflight
Authors: Zupanska Agata K. , LeFrois Collin , Ferl Robert J. , Paul Anna-Lisa
Published: January 2019

Heat Shock Factor A2 (HsfA2) is part of the Heat Shock Factor (HSF) network, and plays an essential role beyond heat shock in environmental stress responses and cellular homeostatic control. Arabidopsis thaliana cell cultures derived from wild type (WT) ecotype Col-0 and a knockout line deficient in the gene encoding HSFA2 (HSFA2 KO) were grown aboard the International Space Station (ISS) to ascertain whether the HSF network functions in the adaptation to the novel environment of spaceflight. Microarray gene expression data were analyzed using a two-part comparative approach. First, genes differentially expressed between the two environments (spaceflight to ground) were identified within the same genotype, which represented physiological adaptation to spaceflight. Second, gene expression profiles were compared between the two genotypes (HSFA2 KO to WT) within the same environment, which defined genes uniquely required by each genotype on the ground and in spaceflight-adapted states. Results showed that the endoplasmic reticulum (ER) stress and unfolded protein response (UPR) define the HSFA2 KO cells’ physiological state irrespective of the environment, and likely resulted from a deficiency in the chaperone-mediated protein folding machinery in the mutant. Results further suggested that additional to its universal stress response role, HsfA2 also has specific roles in the physiological adaptation to spaceflight through cell wall remodeling, signal perception and transduction, and starch biosynthesis. Disabling HsfA2 altered the physiological state of the cells, and impacted the mechanisms induced to adapt to spaceflight, and identified HsfA2-dependent genes that are important to the adaption of wild type cells to spaceflight. Collectively these data indicate a non-thermal role for the HSF network in spaceflight adaptation.
Targeting SUMO Modification of the Non-Structural Protein 5 of Zika Virus as a Host-Targeting Antiviral Strategy
Authors: Zhu Zheng , Chu Hin , Wen Lei , Yuan Shuofeng , Chik Kenn Ka-Heng , Yuen Terrence Tsz-Tai , Yip Cyril Chik-Yan , Wang Dong , Zhou Jie , Yin Feifei , Jin Dong-Yan , Kok Kin-Hang , Yuen Kwok-Yung , Chan Jasper Fuk-Woo
Published: January 2019

Post-translational modifications of host or viral proteins are key strategies exploited by viruses to support virus replication and counteract host immune response. SUMOylation is a post-translational modification process mediated by a family of ubiquitin-like proteins called small ubiquitin-like modifier (SUMO) proteins. Multiple sequence alignment of 78 representative flaviviruses showed that most (72/78, 92.3%) have a putative SUMO-interacting motif (SIM) at their non-structural 5 (NS5) protein’s N-terminal domain. The putative SIM was highly conserved among 414 pre-epidemic and epidemic Zika virus (ZIKV) strains, with all of them having a putative SIM core amino acid sequence of VIDL (327/414, 79.0%) or VVDL (87/414, 21.0%). Molecular docking predicted that the hydrophobic SIM core residues bind to the β2 strand of the SUMO-1 protein, and the acidic residues flanking the core strengthen the binding through interactions with the basic surface of the SUMO protein. The SUMO inhibitor 2-D08 significantly reduced replication of flaviviruses and protected cells against ZIKV-induced cytopathic effects in vitro. A SIM-mutated ZIKV NS5 failed to efficiently suppress type I interferon signaling. Overall, these findings may suggest SUMO modification of the viral NS5 protein to be an evolutionarily conserved post-translational modification process among flaviviruses to enhance virus replication and suppress host antiviral response.
Antibacterial Activities of Lipopeptide (C10)2-KKKK-NH2 Applied Alone and in Combination with Lens Liquids to Fight Biofilms Formed on Polystyrene Surfaces and Contact Lenses
Authors: Paduszynska Malgorzata Anna , Maciejewska Magdalena , Greber Katarzyna Ewa , Sawicki Wieslaw , Kamysz Wojciech
Published: January 2019

The widespread use of biomaterials such as contact lenses is associated with the development of biofilm-related infections which are very difficult to manage with standard therapies. The formation of bacterial biofilms on the surface of biomaterials is associated with increased antibiotic resistance. Owing to their promising antimicrobial potential, lipopeptides are being intensively investigated as novel antimicrobials. However, due to the relatively high toxicity exhibited by numerous compounds, a lot of attention is being paid to designing new lipopeptides with optimal biological activities. The principal aim of this study was to evaluate the potential ophthalmic application of lipopeptide (C10)2-KKKK-NH2. This lipopeptide was synthesized according to Fmoc chemistry using the solid-phase method. The antibiofilm activities of the lipopeptide, antibiotics used in ocular infections, and commercially available lens liquids were determined using the broth dilution method on polystyrene 96-well plates and contact lenses. Resazurin was applied as the cell-viability reagent. The effectiveness of the commercially available lens liquids supplemented with the lipopeptide was evaluated using the same method and materials. (C10)2-KKKK-NH2 exhibited stronger anti-biofilm properties compared to those of the tested conventional antimicrobials and showed the ability to enhance the activity of lens liquids at relatively low concentrations (4–32 mg/L). Estimation of the eye irritation potential of the lipopeptide using Toxtree software 2.6.13 suggests that the compound could be safely applied on the human eye. The results of performed experiments encourage further studies on (C10)2-KKKK-NH2 and its potential application in the prophylaxis of contact lens-related eye infections.
Sinonasal-Related Orbital Infections in Children: A Clinical and Therapeutic Overview
Authors: Torretta Sara , Guastella Claudio , Marchisio Paola , Marom Tal , Bosis Samantha , Ibba Tullio , Drago Lorenzo , Pignataro Lorenzo
Published: January 2019

Sinonasal-related orbital infections (SROIs) are typically pediatric diseases that occur in 3–4% of children with acute rhinosinusitis. They are characterised by various clinical manifestations, such as peri-orbital and orbital cellulitis or orbital and sub-periosteal abscesses that may develop anteriorly or posteriorly to the orbital septum. Posterior septal complications are particularly dangerous, as they may lead to visual loss and life-threatening events, such as an intracranial abscess and cavernous sinus thrombosis. Given the possible risk of permanent visual loss due to optic neuritis or orbital nerve ischemia, SROIs are considered ophthalmic emergencies that need to be promptly recognised and treated in an urgent-care setting. The key to obtaining better clinical outcomes in children with SROIs is a multi-disciplinary assessment by pediatricians, otolaryngologists, ophthalmologists, radiologists, and in selected cases, neurosurgeons, neurologists, and infectious disease specialists. The aim of this paper is to provide an overview of the pathogenesis, clinical manifestations, diagnosis, and treatment of pediatric SROIs, and to make some practical recommendations for attending clinicians.
Electroactive Smart Polymers for Biomedical Applications
Authors: Palza Humberto , Zapata Paula Andrea , Angulo-Pineda Carolina
Published: January 2019

The flexibility in polymer properties has allowed the development of a broad range of materials with electroactivity, such as intrinsically conductive conjugated polymers, percolated conductive composites, and ionic conductive hydrogels. These smart electroactive polymers can be designed to respond rationally under an electric stimulus, triggering outstanding properties suitable for biomedical applications. This review presents a general overview of the potential applications of these electroactive smart polymers in the field of tissue engineering and biomaterials. In particular, details about the ability of these electroactive polymers to: (1) stimulate cells in the context of tissue engineering by providing electrical current; (2) mimic muscles by converting electric energy into mechanical energy through an electromechanical response; (3) deliver drugs by changing their internal configuration under an electrical stimulus; and (4) have antimicrobial behavior due to the conduction of electricity, are discussed.
Study on the Fabrication of Super-Hydrophobic Surface on Inconel Alloy via Nanosecond Laser Ablation
Authors: Yang Zhen , Tian Yanling , Zhao Yuechao , Yang Chengjuan
Published: January 2019

Nanosecond laser ablated metallic surfaces showed initial super-hydrophilicity, and then experienced gradual wettability conversion to super-hydrophobicity with the increase of exposing time to ambient air. Due to the presence of hierarchical structures and change of surface chemistry, the laser-induced Inconel alloy surfaces showed a stable apparent contact angle beyond 150° over 30-day air exposure. The wetting states were proposed to elucidate the initial super-hydrophilicity and the final super-hydrophobicity. The basic fundaments behind the wettability conversion was explored by analyzing surface chemistry using X-ray photoelectron spectroscopy (XPS). The results indicated that the origins of super-hydrophobicity were identified as the increase of carbon content and the dominance of C–C(H) functional group. The C–C(H) bond with excellent nonpolarity derived from the chemisorbed airborne hydrocarbons, which resulted in dramatic reduction of surface-free-energy. This study confirmed that the surface chemistry is not the only factor to determine surface super-hydrophobicity. The laser-induced super-hydrophobicity was attributed to the synergistic effect of surface topography and surface chemical compositions. In this work, the corresponding chemical reaction was particularly described to discuss how the airborne hydrocarbons were attached onto the laser ablated surfaces, which reveals the generation mechanism of air-exposed super-hydrophobic surfaces.
Stress-Strain Response of Cylindrical Rubber Fender under Monotonic and Cyclic Compression
Authors: Wu Chia-Chin , Chiou Yung-Chuan
Published: January 2019

The study was devoted to the observation and modeling the mechanical behaviors of a hybrid SBR/NR (Styrene-Butadiene/Natural Rubber) hybrid vulcanized rubber fender under monotonic/cyclic compression. In experimental observations of the monotonic compression tests, it was found that lateral deformation occurred on the tested fender and was more significant with increasing the extent of the compressive strain. The relationship between the transmission stress S c and the compressive strain e c was nonlinear and the absorbed strain-energy-density was increased monotonically with the increment of the compressive strain. Among all cyclic compression tests with strain controlled, the reductions in both the stress range and the absorbed strain-energy-density up to the ten-thousandth cycle were found and then both of the cyclic properties remain approximately constant in the following compression cycles. Two new properties, the softening factor and the energy reduction factor, were introduced to quantify the effect of the strain range on the extent of the reduction in stress range and that on the absorbed strain-energy-density, respectively. It was found that both of the calculated values of the new properties increase with the increment of strain range. In mathematical modeling of the relationship between the transmission stress and the compressive strain, a new approach based on energy-polynomial-function E s ( e c ) was presented and was successfully used to simulate the monotonic curve and the stable hysteresis loop curves of the tested rubber fender in compression. Essentially, the energy-polynomial-function E s ( e c ) was obtained by performing a polynomial regression on a large amount of ( e c , E s ) data. Moreover, the least-square approach was applied to determine the corresponding regression coefficients in E s ( e c ) . Clearly, the stress-polynomial-function in modeling the S c − e c curve could be obtained from the differentiation of the energy-polynomial-function with respect to the compressive strain. In addition, to provide an adequate estimation of the mechanical properties of the cylindrical rubber fender under compression, the named cyclic stress-strain curve and cyclic energy-strain curve were developed and also modeled in this study.
Microstructure and Mechanical Properties of Pressure-Quenched SS304 Stainless Steel
Authors: Wang Peng , Zhang Yang , Yu Dongli
Published: January 2019

Bulk SS304 polycrystalline materials with ultrafine microstructures were prepared via a high-pressure self-heating melting and quenching method. Analyses of phase composition, grain size and microstructure were performed using metallographic analysis, X-ray diffraction, Rietveld refinement and transmission electron microscope (TEM). The effects of pressure and cooling rate on the solidification of SS304 were analyzed. Mechanical property test results show that, compared with the as-received sample, the hardness and the yield strength of the pressure-quenched (PQ) samples were greatly increased, the ultimate tensile strength changed minimally, and the elongation rate became small, primarily due to the large density of dislocations in the sample. The high-pressure self-heating melting and quenching method is an exotic route to process a small piece of steel with moderate properties and ultrafine microstructure.
Clerodane Diterpenes from the Marine Sponge Raspailia bouryesnaultae Collected in South Brazil
Authors: Lhullier Cintia , de Oliveira Tabalipa Eliane , Nienkötter Sardá Fernanda , Sandjo Louis Pergaud , Zanchett Schneider Naira Fernanda , Carraro João Luis , Oliveira Simões Cláudia Maria , Schenkel Eloir Paulo
Published: January 2019

The marine sponge Raspailia bouryesnaultae, collected in South Brazil, was selected for detailed investigation considering the results of a screening that pointed to an in vitro antiproliferative effect against non-small cells of human lung cancer (A549) and anti-herpes activity against Herpes Simplex virus type 1 (KOS and 29R strains) of ethanolic extracts. The fractionation and chemical investigation of the sponge’s hexanic fraction led to the isolation and structural elucidation of six clerodane diterpenes. The main component was identified as the already-reported raspailol (1), isolated from a sponge of the same genus collected in New Zealand. The structure of a new diterpene (2) with a rearranged skeleton was established by high-resolution mass spectrometry (HRMS) and 1D and 2D Nuclear magnetic resonance spectroscopy (NMR) experiments, and named here as raspadiene. Furthermore, four diterpenes were elucidated as isomers of clerodane diterpenes previously obtained from plants, namely kerlinic acid (3), kerlinic acid methyl ester (4), annonene (5), and 6-hydroxyannonene (6). They differ in their stereochemistry, since these diterpenes are characterized by a trans ring fusion at the decalin moiety and the relative configuration of the two methyl groups at C-8 and C-9 in a cis relationship (type trans/cis). The Raspailia diterpenes have a cis ring fusion at the decalin moiety, and the two methyl groups at C-8 and C-9 are in a trans relationship (type cis/trans). The isolated compounds were evaluated for their potential antiproliferative effects on human cancer cell line A549, and it was observed that the diterpenes bearing a hydroxyl group at C-6 exhibited moderate cytotoxic activity, with 50% inhibitory concentration (IC50) values lower than 25 μM. The evaluation of the potential anti-herpes activity against Herpes Simplex Virus type 1 (HSV-1, KOS and 29R strains) showed that the more promising results were observed for the new compound 2, since it inhibited HSV-1 (KOS and 29R strains) replication by 83% and 74%, respectively.
The Effect of a Pilot Dietary Intervention on Pain Outcomes in Patients Attending a Tertiary Pain Service
Authors: Brain Katherine , Burrows Tracy L. , Rollo Megan E. , Hayes Chris , Hodson Fiona J. , Collins Clare E.
Published: January 2019

The aim of this study was to examine the effect of a six-week 2 × 2 design on pain scores, quality of life, and dietary intake in patients attending an Australian tertiary pain clinic. The two intervention components were (1) personalized dietary consultations or waitlist control, and (2) active or placebo dietary supplement (fruit juice). Sixty participants were randomized into one of four groups at baseline (68% female, mean age 49 ± 15 years) with 42 completing the study (70% retention). All groups had statistically significant improvements in three of five pain outcomes. The personalized dietary consultation groups had clinically important improvements in three of five pain outcomes compared to the waitlist control groups. All groups had a statistically significant improvement in six of eight quality-of-life categories post intervention. All groups increased percentage energy from nutrient-dense foods (+5.2 ± 1.4%, p < 0.001) with a significant group-by-time effect for percentage energy from total fat (p = 0.024), with the personalized dietary consultations plus placebo fruit juice reporting the largest reduction (−5.7 ± 2.3%). This study indicates that dietitian-delivered dietary intervention can improve pain scores, quality of life, and dietary intake of people experiencing chronic pain. Future research should evaluate efficacy in a full-powered randomized control trial.
Prevalence of Anemia in Children from Latin America and the Caribbean and Effectiveness of Nutritional Interventions: Systematic Review and Meta–Analysis
Authors: Iglesias Vázquez Lucía , Valera Edith , Villalobos Marcela , Tous Mónica , Arija Victoria
Published: January 2019

Anemia affects 1.62 billion people worldwide. Latin America and the Caribbean (LAC) comprise several developing countries where children are a population at risk. This systematic review and meta-analysis aimed to estimate the prevalence of anemia in this population. Electronic databases, reference lists, and websites of health ministries were searched until December 2018. Stratified analyses were performed using RevMan5.3 to estimate the overall prevalence of anemia in preschool and school-age children. The effectiveness of nutritional interventions was also evaluated. We included 61 studies from the 917 reviewed, which included 128,311 preschool- and 38,028 school-age children from 21 LAC countries. The number of anemic children was 32.93% and 17.49%, respectively, demonstrating a significant difference according to age (p < 0.01). No difference was observed by gender and only school-age children from low/very low socioeconomic status (SES) (25.75%) were more prone to anemia than those from middle SES (7.90%). It was not a concern in the Southern Cone but constituted a serious public health problem in the Latin Caribbean. Nutritional interventions reduced the prevalence from 45% to 25% (p < 0.01). Anemia is still a public health problem for children in LAC countries. National surveys should include school-age children. Further nutritional interventions are required to control anemia.
Understanding Barriers and Enablers to State Action on Salt: Analysis of Stakeholder Perceptions of the VicHealth Salt Reduction Partnership
Authors: McKenzie Briar , Trieu Kathy , Grimes Carley A. , Reimers Jenny , Webster Jacqui
Published: January 2019

The Victorian Salt Reduction Partnership (VicSalt Partnership) was launched in 2015, bringing together health and research organisations to develop an action plan for salt reduction interventions at a state level. A comprehensive evaluation was designed to assess the impact of the resulting four-year intervention strategy. As part of the process evaluation, semi-structured interviews were undertaken with stakeholders in March–May 2017, to understand perceived barriers and enablers to effective strategy implementation. Data were coded in relation to the key topic areas of the interviews with an inductive method used to analyse themes within topics. Seventeen stakeholders were contacted, 14 completed an interview; five from state government or statutory agencies, four from non-government funded organisations, four from research organisations and one from the food industry. Twelve were members of the VicSalt Partnership and two were informal collaborators. Most stakeholders viewed the VicSalt Partnership as a positive example of working collaboratively, and said this was essential for raising awareness of the importance of salt reduction with consumers, the food industry, and the government. Challenges relating to engaging the food industry and federal government through a state-led initiative were identified. New approaches to overcome this, such as forming clear “asks” to government and committing industry to “pledges” on reformulation were suggested. Stakeholder interviews and qualitative analysis have provided a range of important insights into barriers and enablers, many of which have already been used to strengthen intervention implementation. The evaluation of the VicSalt Partnership is ongoing and the program is expected to provide a wealth of lessons for state-led interventions to reduce salt intake in Australia and globally.
Letter to the Editor Re: Borschel M., et al. Comparison of Growth of Healthy Term Infants Fed Extensively Hydrolyzed Protein- and Amino Acid-Based Infant Formulas. Nutrients 2018, 10, 289
Authors: Harvey Bryan M. , Langford Jane E.
Published: January 2019

We read with interest the recently published narrative review of seven growth studies in healthy infants fed extensively hydrolyzed protein-based formulas (eHF) and amino acid-based formulas (AAF) [...]
A Randomized, Controlled Trial of Vitamin D Supplementation on Cardiovascular Risk Factors, Hormones, and Liver Markers in Women with Polycystic Ovary Syndrome
Authors: Javed Zeeshan , Papageorgiou Maria , Deshmukh Harshal , Kilpatrick Eric S. , Mann Vincent , Corless Lynsey , Abouda George , Rigby Alan S. , Atkin Stephen L. , Sathyapalan Thozhukat
Published: January 2019

Polycystic ovary syndrome (PCOS) increases the risk of metabolic syndrome and non-alcoholic-fatty-liver disease (NAFLD). Vitamin D supplementation may exert positive effects on liver biochemistry in patients with NAFLD; however, its effects on PCOS are unknown. This randomized, double-blind, placebo-controlled study explored the effect of vitamin D supplementation on cardiovascular risk factors (high-sensitivity C-reactive protein (hs-CRP), weight, body mass index (BMI), lipid profile, glucose levels, insulin levels, the homeostatic model assessment-insulin resistance (HOMA-IR), hormones (free androgen index (FAI), testosterone, sex hormone binding globulin (SHBG), and liver markers (alanine aminotransferase (ALT), hyaluronic acid (HA), N-terminal pro-peptide of type III procollagen (PIIINP), tissue inhibitor of metallo-proteinases-1 (TIMP-1), and the enhanced liver fibrosis (ELF) score). Forty women with PCOS were recruited and randomized to vitamin D (3200 IU) or placebo daily for 3 months. All outcomes were measured at baseline and 3 months follow-up (FU). Greater increases in vitamin D levels were shown in the supplementation group (vitamin D, baseline: 25.6 ± 11.4 nmol/L, FU: 90.4 ± 19.5 nmol/L vs. placebo, baseline: 30.9 ± 11.1 nmol/L, FU: 47.6 ± 20.5 nmol/L, p < 0.001). Between groups comparisons (% baseline change) revealed significant differences in ALT (p = 0.042) and a weak effect indicating a greater reduction in the HOMA-IR in the vitamin D group (p = 0.051). No further between group differences were seen in other cardiovascular risk factor, liver markers, or hormones. This study supports beneficial effects of vitamin D supplementation on liver markers and modest improvements in insulin sensitivity in vitamin D deficient women with PCOS.
Enhanced In Situ Availability of Aphanizomenon Flos-Aquae Constituents Entrapped in Buccal Films for the Treatment of Oxidative Stress-Related Oral Diseases: Biomechanical Characterization and In Vitro/Ex Vivo Evaluation
Authors: De Caro Viviana , Murgia Denise , Seidita Francesco , Bologna Emanuela , Alotta Gioacchino , Zingales Massimiliano , Campisi Giuseppina
Published: January 2019

In recent years, the key role of oxidative stress in pathogenesis of oral diseases has been emphasized and the use of antioxidant agents has been encouraged. Aphanizomenon flos-aquae (AFA) is a unicellular blue-green alga with antioxidant and anti-inflammatory properties. The aim of this study was the formulation and characterization of mucoadhesive thin layer films loaded with AFA, finalized to the treatment of oxidative stress (OS)-related oral diseases. First, to enhance the bioavailability of AFA constituents, the raw food grade material was appropriately treated by a high frequency homogenization able to disrupt cell walls. Thus, Eudragit® E100-based buccal films were produced by the solvent casting method, containing 7% and 18% of AFA. The films, characterized by uniformity in thickness, weight, and drug content, showed low swelling degree, good muco-adhesiveness and controlled drug release. The mechanical tests showed elastic moduli of films of almost 5 MPa that is well-suitable for human buccal applications without discomfort, besides biaxial tests highlighted a marked material isotropy. Permeation studies through porcine mucosae demonstrated the ability of films to promote AFA penetration in the tissues, and when sublingually administered, they produced a drug flux up to six-fold higher than an AFA solution. The new formulations represent an interesting alternative for the development of cosmetics and nutraceuticals with a functional appeal containing plant extracts.
Cavity Closure of 2-Hydroxypropyl-β-Cyclodextrin: Replica Exchange Molecular Dynamics Simulations
Authors: Kerdpol Khanittha , Kicuntod Jintawee , Wolschann Peter , Mori Seiji , Rungnim Chompoonut , Kunaseth Manaschai , Okumura Hisashi , Kungwan Nawee , Rungrotmongkol Thanyada
Published: January 2019

2-Hydroxypropyl-β-cyclodextrin (HPβCD) has unique properties to enhance the stability and the solubility of low water-soluble compounds by inclusion complexation. An understanding of the structural properties of HPβCD and its derivatives, based on the number of 2-hydroxypropyl (HP) substituents at the α-d-glucopyranose subunits is rather important. In this work, replica exchange molecular dynamics simulations were performed to investigate the conformational changes of single- and double-sided HP-substitution, called 6-HPβCDs and 2,6-HPβCDs, respectively. The results show that the glucose subunits in both 6-HPβCDs and 2,6-HPβCDs have a lower chance of flipping than in βCD. Also, HP groups occasionally block the hydrophobic cavity of HPβCDs, thus hindering drug inclusion. We found that HPβCDs with a high number of HP-substitutions are more likely to be blocked, while HPβCDs with double-sided HP-substitutions have an even higher probability of being blocked. Overall, 6-HPβCDs with three and four HP-substitutions are highlighted as the most suitable structures for guest encapsulation, based on our conformational analyses, such as structural distortion, the radius of gyration, circularity, and cavity self-closure of the HPβCDs.
Impact Energy Release Characteristics of PTFE/Al/CuO Reactive Materials Measured by a New Energy Release Testing Device
Authors: Ding Liangliang , Zhou Jingyuan , Tang Wenhui , Ran Xianwen , Hu Yuxuan
Published: January 2019

Metal/polymer reactive materials have been studied and applied in a wide range of ways in recent years. This type of material is insensitive under normal conditions but reacts violently and releases a large amount of chemical energy under high-speed impact or high strain rate loading conditions. Compared with conventional explosives, it has better mechanical properties, and its unit mass energy is several times that of TNT. In this paper, PTFE/Al/CuO reactive materials are the main research objects, and we assess the impact energy release abilities of this type of reactive material through experimental research. To this end, eight sets of material formulations are designed, and the effects of particle size, the ratio of PTFE/Al and Al/CuO materials, and sintering on the energy release ability of the reactive materials are investigated. All experiments are carried out based on a self-designed new energy release testing device. The experimental device can measure the pressure time history curve generated by the reactive materials, and the rationality of the pressure time history curve can also be verified by the displacement time curve of the piston. The results show that with an increase in the Al/CuO thermite content, the energy release rate of the reactive material clearly increases, which is attributed to the reaction threshold of Al/CuO being low and because the heat generated can promote the reaction of PTFE/Al. The energy release rate of the nano-scale reactive materials is higher than that of the micron-scale reactive materials because the reduction in particle size results in a larger specific surface area. Thus, the energy required for ignition is lower. The energy release rate of sintered reactive materials is higher than that of unsintered reactive materials, which can be explained by the interfacial area between Al particles and PTFE particles in sintered reactive materials being larger, which makes the reaction more sufficient. The self-designed energy release testing device for the reactive materials and the conclusions obtained in this paper have clear significance for guiding engineering applications.
Hierarchical Ag Nanostructures Fabricated from Silver Coordination Polymers for Antibacterial Surface
Authors: Jung Jin-Song , Ko Su-Joung , Lee Hong-Beom , Lee Su-Bin , Kim Hyoung-Jun , Oh Jae-Min
Published: January 2019

A hierarchical silver nanostructure with improved antibacterial property was fabricated utilizing silver coordination polymer. Octadecanethiolate–silver polymer was synthesized to have a layered structure and was coated on silicon wafer by drop-casting method utilizing hydrophobic–hydrophobic interaction. Thus, the silver coordination polymer was calcined under reductive condition to produce zero-valent silver with a hierarchical nanostructure. X-ray diffraction patterns revealed that layered silver coordination polymer successfully transformed to hexagonal silver upon calcination. According to scanning electron and atomic force microscopy, silver coordination polymer with ~145.5 nm size was homogeneously coated on the surface before calcination, and it evolved micrometer-sized lumps and grooves which were composed of ~58.8 nm sized Ag nanoparticles. The hierarchical structure—micrometer lump/groove consisting of Ag nanoparticles—would be advantageous to kill bacteria; micrometer-grooves provide physical condition (pocket for bacteria capture) and the Ag nanoparticles from the neighboring lump endow chemical condition (antibacterial property of released Ag+). The antibacterial activity test on Escherichia coli via colony forming inhibitory assay indeed exhibited an improved antibacterial activity of hierarchical Ag nanostructure compared with the surface simply coated with Ag nanoparticles. From the line profile of atomic force microscopy, the bacterium trapped in the hierarchical Ag nanostructure was shown to interact intimately with Ag surface.
Sol–Gel-Processed Organic–Inorganic Hybrid for Flexible Conductive Substrates Based on Gravure-Printed Silver Nanowires and Graphene
Authors: Li Xinlin , Kim Nahae , Youn Seongwook , An Tae Kyu , Kim Juyoung , Lim Sooman , Kim Se Hyun
Published: January 2019

In this study, an organic–inorganic (O–I) nanohybrid obtained by incorporating an alkoxysilane-functionalized amphiphilic polymer precursor into a SiO2–TiO2 hybrid network was successfully utilized as a buffer layer to fabricate a flexible, transparent, and stable conductive substrate for solution-processed silver nanowires (AgNWs) and graphene under ambient conditions. The resulting O–I nanohybrid sol (denoted as AGPTi) provided a transmittance of the spin-coated AgNWs on an AGPTi-coated glass of 99.4% and high adhesion strength after a 3M tape test, with no visible changes in the AgNWs. In addition, AGPTi acted as a highly functional buffer layer, absorbing the applied pressure between the conductive materials, AgNWs and graphene, and rigid substrate, leading to a significant reduction in sheet resistance. Furthermore, gravure-printed AgNWs and graphene on the AGPTi-based flexible substrate had uniform line widths of 490 ± 15 and 470 ± 12 µm, with 1000-cycle bending durabilities, respectively.
Effect of Thermal Ageing on the Impact Damage Resistance and Tolerance of Carbon-Fibre-Reinforced Epoxy Laminates
Authors: García-Moreno Irene , Caminero Miguel , Rodríguez Gloria , López-Cela Juan
Published: January 2019

Composite structures are particularly vulnerable to impact, which drastically reduces their residual strength, in particular, at high temperatures. The glass-transition temperature (Tg) of a polymer is a critical factor that can modify the mechanical properties of the material, affecting its density, hardness and rigidity. In this work, the influence of thermal ageing on the low-velocity impact resistance and tolerance of composites is investigated by means of compression after impact (CAI) tests. Carbon-fibre-reinforced polymer (CFRP) laminates with a Tg of 195 °C were manufactured and subjected to thermal ageing treatments at 190 and 210 °C for 10 and 20 days. Drop-weight impact tests were carried out to determine the impact response of the different composite laminates. Compression after impact tests were performed in a non-standard CAI device in order to obtain the compression residual strength. Ultrasonic C-scanning of impacted samples were examined to assess the failure mechanisms of the different configurations as a function of temperature. It was observed that damage tolerance decreases as temperature increases. Nevertheless, a post-curing process was found at temperatures below the Tg that enhances the adhesion between matrix and fibres and improves the impact resistance. Finally, the results obtained demonstrate that temperature can cause significant changes to the impact behaviour of composites and must be taken to account when designing for structural applications.
Differential Colonization Dynamics of Marine Biofilm-Forming Eukaryotic Microbes on Different Protective Coating Materials
Authors: Lang Yanhe , Sun Yuan , Yu Miao , Ji Yubin , Wang Lei , Zhang Zhizhou
Published: January 2019

In this study, the actual anti-biofouling (AF) efficacy of three protective coatings, including a chlorinated rubber-based coating (C0) and two polydimethylsiloxane (PDMS)-based coatings (P0 and PF), were estimated via the static field exposure assays. The surface properties of these protective coatings, including surface wettability and morphology features, were characterized using the static water contact angle (WCA) and scanning electron microscope (SEM). The colonization and succession dynamics of the early-adherent biofilm-forming eukaryotic microbial communities occupied on these protective coatings were explored using the Single-stranded Conformation Polymorphism (SSCP) technique. The field data clearly revealed that coating P0 and PF performed better in the long-term static submergence, as compared with the C0 surface, while coating PF showed excellent AF efficacy in the field. Fingerprinting analysis suggested that the diversity, abundance, the clustering patterns, and colonization dynamics of the early-colonized eukaryotic microbes were significantly perturbed by these protective coatings, particularly by the PF surfaces. These differential AF efficacy and perturbation effects would be largely ascribed to the differences in the wettability and surface nanostructures between the C0, P0 and PF surfaces, as evidenced by WCA and SEM analysis.
Role of Molecular Weight in Polymer Wrapping and Dispersion of MWNT in a PVDF Matrix
Authors: Namasivayam Muthuraman , Andersson Mats R. , Shapter Joseph
Published: January 2019

The thermal and electrical properties of a polymer nanocomposite are highly dependent on the dispersion of the CNT filler in the polymer matrix. Non-covalent functionalisation with a PVP polymer is an excellent driving force towards an effective dispersion of MWNTs in the polymer matrix. It is shown that the PVP molecular weight plays a key role in the non-covalent functionalisation of MWNT and its effect on the thermal and electrical properties of the polymer nanocomposite is reported herein. The dispersion and crystallisation behaviour of the composite are also evaluated by a combination of scanning electron microscopy (SEM) and differential scanning calorimetry (DSC).
Micelle Structure Details and Stabilities of Cyclic Block Copolymer Amphiphile and Its Linear Analogues
Authors: Ree Brian J. , Satoh Toshifumi , Yamamoto Takuya
Published: January 2019

In this study, we investigate structures and stabilities of the micelles of a cyclic amphiphile (c-PBA-b-PEO) composed of poly(n-butyl acrylate) (PBA) and poly(ethylene oxide) (PEO) blocks and its linear diblock and triblock analogues (l-PBA-b-PEO and l-PBA-b-PEO-b-PBA) by using synchrotron X-ray scattering and quantitative data analysis. The comprehensive scattering analysis gives details and insights to the micellar architecture through structural parameters. Furthermore, this analysis provides direct clues for structural stabilities in micelles, which can be used as a good guideline to design highly stable micelles. Interestingly, in water, all topological polymers are found to form ellipsoidal micelles rather than spherical micelles; more interestingly, the cyclic polymer and its linear triblock analog make oblate-ellipsoidal micelles while the linear diblock analog makes a prolate-ellipsoidal micelle. The analysis results collectively inform that the cyclic topology enables more compact micelle formation as well as provides a positive impact on the micellar structural integrity.
Participation as a Christian Ethic: Wojtyla’s Phenomenology of Subject-in-Community, Ubuntu, and the Trinity
Authors: Pembroke Neil
Published: January 2019

Participation is defined as being-with and acting-for others with the aim of advancing the common good. Karol Wojtyla’s philosophy of community and the Sub-Saharan ethic known as Ubuntu are used to describe a participative ethic. These philosophies approach participation in a particular way—namely, through positing both an ‘I-Thou’ and a ‘We’ dimension. Neither in Wojtyla’s philosophy, nor in Ubuntu, do we find references to Christian theology. Though it is evident that these philosophies incorporate certain moral values embraced by the Christian community, it is necessary to make the theological alignment explicit. The main aim of the essay is to do just that. It is argued that participation is rightly construed as a Trinitarian ethic.
A Multisensor Approach to Satellite Monitoring of Trends in Lake Area, Water Level, and Volume
Authors: Chipman Jonathan W.
Published: January 2019

Lakes in arid regions play an important role in regional water cycles and are a vital economic resource, but can fluctuate widely in area and volume. This study demonstrates the use of a multisensor satellite remote sensing method for the comprehensive monitoring of lake surface areas, water levels, and volume for the Toshka Lakes in southern Egypt, from lake formation in 1998 to mid-2017. Two spectral water indices were used to construct a daily time-series of surface area from the Advanced Very High Resolution Radiometer (AVHRR) and the Moderate Resolution Imaging Spectroradiometer (MODIS), validated by higher-resolution Landsat images. Water levels were obtained from analysis of digital elevation models from the Shuttle Radar Topography Mission (SRTM) and the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER), validated with ICESat Geoscience Laser Altimeter System (GLAS) laser altimetry. Total lake volume peaked at 26.54 × 109 m3 in December 2001, and declined to 0.76 × 109 m3 by August 2017. Evaporation accounted for approximately 86% of the loss, and groundwater recharge accounted for 14%. Without additional inflows, the last remaining lake will likely disappear between 2020 and 2022. The Enhanced Lake Index, a water index equivalent to the Enhanced Vegetation Index, was found to have lower noise levels than the Normalized Difference Lake Index. The results show that multi-platform satellite remote sensing provides an efficient method for monitoring the hydrology of lakes.
Hyperspectral Images Classification Based on Dense Convolutional Networks with Spectral-Wise Attention Mechanism
Authors: Fang Bei , Li Ying , Zhang Haokui , Chan Jonathan Cheung-Wai
Published: January 2019

Hyperspectral images (HSIs) data that is typically presented in 3-D format offers an opportunity for 3-D networks to extract spectral and spatial features simultaneously. In this paper, we propose a novel end-to-end 3-D dense convolutional network with spectral-wise attention mechanism (MSDN-SA) for HSI classification. The proposed MSDN-SA exploits 3-D dilated convolutions to simultaneously capture the spectral and spatial features at different scales, and densely connects all 3-D feature maps with each other. In addition, a spectral-wise attention mechanism is introduced to enhance the distinguishability of spectral features, which improves the classification performance of the trained models. Experimental results on three HSI datasets demonstrate that our MSDN-SA achieves competitive performance for HSI classification.
Flash Flood Risk Analysis Based on Machine Learning Techniques in the Yunnan Province, China
Authors: Ma Meihong , Liu Changjun , Zhao Gang , Xie Hongjie , Jia Pengfei , Wang Dacheng , Wang Huixiao , Hong Yang
Published: January 2019

Flash flood, one of the most devastating weather-related hazards in the world, has become more and more frequent in past decades. For the purpose of flood mitigation, it is necessary to understand the distribution of flash flood risk. In this study, artificial intelligence (Least squares support vector machine: LSSVM) and classical canonical method (Logistic regression: LR) are used to assess the flash flood risk in the Yunnan Province based on historical flash flood records and 13 meteorological, topographical, hydrological and anthropological factors. Results indicate that: (1) the LSSVM with Radial basis function (RBF) Kernel works the best (Accuracy = 0.79) and the LR is the worst (Accuracy = 0.75) in testing; (2) flash flood risk distribution identified by the LSSVM in Yunnan province is near normal distribution; (3) the high-risk areas are mainly concentrated in the central and southeastern regions, where with a large curve number; and (4) the impact factors contributing the flash flood risk map from higher to low are: Curve number > Digital elevation > Slope > River density > Flash Flood preventions > Topographic Wetness Index > annual maximum 24 h precipitation > annual maximum 3 h precipitation.
Acoustic Stimulation by Shunt-Diode Pre-Linearizer Using Very High Frequency Piezoelectric Transducer for Cancer Therapeutics
Authors: Choi Hojong , Choe Se-woon
Published: January 2019

In this paper, we proposed cancer cell acoustic stimulation by shunt-diode pre-linearizer scheme using a very high frequency (≥100 MHz) piezoelectric transducer. To verify the concept of our proposed scheme, we performed pulse-echo detection, and accessed therapeutic effects of human cervical cancer cells exposed to acoustic stimulation experiments using 100 MHz focused piezoelectric transducer triggered by PA with and without the proposed shunt-diode pre-linearizer scheme. In the pulse-echo detection responses, the peak-to-peak voltage of the echo signal when using the PA with shunt-diode pre-linearizer (49.79 mV) was higher than that when using the PA alone (29.87 mV). In the experimental results, the cell densities of cancer cells on Day 4 when using no acoustic stimulation (control group), the very high-frequency piezoelectric transducer triggered by PA only and PA combined with proposed pre-linearizer schemes (1 V and 5 V DC bias voltages) showed 100%, 92.8 ± 4.2%, 84.2 ± 4.6%, and 78 ± 2.9%, respectively. Therefore, we confirmed that the shunt-diode pre-linearizer could improve the performances of the pulse signals of the PA, thus, enabling better therapeutic stimulation performances for cancer cell suppression.
Vehicle-to-Pedestrian Communication for Vulnerable Road Users: Survey, Design Considerations, and Challenges
Authors: Sewalkar Parag , Seitz Jochen
Published: January 2019

In the last few years, increasing attention has been provided to research Vehicle-to-Pedestrian (V2P) communication systems. These V2P systems serve different purposes (safety or convenience) and cater to different Vulnerable Road User (VRU) groups. Also, these V2P systems employ different communication technologies, and use different mechanisms to interact with the users. An effective V2P system also needs to consider varying characteristics of different VRUs. These various elements may be considered as design parameters of the V2P system. In this paper, we discuss such elements and propose a design framework for the V2P system based on them. We also provide an extensive survey of existing V2P efforts for safety and convenience applications and their design considerations. We perform a case study that compares the different approaches of V2P safety system for different VRU groups under different pre-crash scenarios. Finally, we discuss a few technological challenges in integration of VRUs into V2X systems.
Experimental and Numerical Study of a Thermal Expansion Gyroscope for Different Gases
Authors: Kock Guillaume , Combette Philippe , Tedjini Marwan , Schneider Markus , Gauthier-Blum Caroline , Giani Alain
Published: January 2019

A new single-axis gas thermal gyroscope without proof mass is presented in this paper. The device was designed, manufactured and experimentally characterized. The obtained results were compared to numerical simulation. The working principle of the gyroscope is based on the deflection of a laminar gas flow caused by the Coriolis effect. A bidirectional hot air flow is generated by alternating activation of two suspended resistive micro-heaters. The heated gas is encapsulated in a semi-open cavity and the gas expands primarily inside the cavity. The thermal expansion gyroscope has a simple structure. Indeed, the device is composed of a micromachined cavity on which three bridges are suspended. The central bridge is electrically separated into two segments enabling to set up two heaters which may be supplied independently from each other. The two other bridges, placed symmetrically on each side of the central bridge, are equipped with temperature detectors which measure variations in gas temperature. The differential temperature depends on the rotational velocity applied to the system. Various parameters such as the heating duty cycle, the type of the gas and the power injected into the heaters have been studied to define the optimal working conditions required to obtain the highest level of sensitivity over a measurement range of around 1000°/s. The robustness of the device has also been tested and validated for a shock resistance of 10,000 g for a duration of 400 µs.