bluuebunny/crossref_metadata_2025 huggingface dataset:
Maturing Mycobacterium smegmatis peptidoglycan requires non-canonical crosslinks to maintain shape
Authors: Baranowski Catherine , Welsh Michael A , Sham Lok-To , Eskandarian Haig A , Lim Hoong Chuin , Kieser Karen J , Wagner Jeffrey C , McKinney John D , Fantner Georg E , Ioerger Thomas R , Walker Suzanne , Bernhardt Thomas G , Rubin Eric J , Rego E Hesper
Published: October 2018

In most well-studied rod-shaped bacteria, peptidoglycan is primarily crosslinked by penicillin-binding proteins (PBPs). However, in mycobacteria, crosslinks formed by L,D-transpeptidases (LDTs) are highly abundant. To elucidate the role of these unusual crosslinks, we characterized Mycobacterium smegmatis cells lacking all LDTs. We find that crosslinks generate by LDTs are required for rod shape maintenance specifically at sites of aging cell wall, a byproduct of polar elongation. Asymmetric polar growth leads to a non-uniform distribution of these two types of crosslinks in a single cell. Consequently, in the absence of LDT-mediated crosslinks, PBP-catalyzed crosslinks become more important. Because of this, Mycobacterium tuberculosis (Mtb) is more rapidly killed using a combination of drugs capable of PBP- and LDT- inhibition. Thus, knowledge about the spatial and genetic relationship between drug targets can be exploited to more effectively treat this pathogen.
A biological switching valve evolved in the female of a sex-role reversed cave insect to receive multiple seminal packages
Authors: Yoshizawa Kazunori , Kamimura Yoshitaka , Lienhard Charles , Ferreira Rodrigo L , Blanke Alexander
Published: October 2018

We report a functional switching valve within the female genitalia of the Brazilian cave insect Neotrogla. The valve complex is composed of two plate-like sclerites, a closure element, and in-and-outflow canals. Females have a penis-like intromittent organ to coercively anchor males and obtain voluminous semen. The semen is packed in a capsule, whose formation is initiated by seminal injection. It is not only used for fertilization but also consumed by the female as nutrition. The valve complex has two slots for insemination so that Neotrogla can continue mating while the first slot is occupied. In conjunction with the female penis, this switching valve is a morphological novelty enabling females to compete for seminal gifts in their nutrient-poor cave habitats through long copulation times and multiple seminal injections. The evolution of this switching valve may have been a prerequisite for the reversal of the intromittent organ in Neotrogla.
Gene losses did not stop the evolution of big brains
Authors: Cañestro Cristian , Roncalli Vittoria
Published: October 2018

Elephants and fruit bats have evolved large brains even though they have lost a gene that is fundamental to the supply of energy to the brain when glucose is not available.
Analysis of adult damselfly fecal material aids in the estimation of antibiotic-resistant Enterobacterales contamination of the local environment
Authors: Yamaguchi Yuyu , Okubo Torahiko , Matsushita Mizue , Wataji Masashi , Iwasaki Sumio , Hayasaka Kasumi , Akizawa Kouzi , Matsuo Junji , Shimizu Chikara , Yamaguchi Hiroyuki
Published: October 2018

Because damselflies are ubiquitously but focally present in natural environments and play a critical role as predators of other insect species, the fecal matter of damselflies may be useful for investigating antibiotic-resistant bacterial populations, including human pathogens, in local environments. We therefore examined the prevalence of antibiotic-resistant bacteria, including Enterobacterales, in fecal material from 383 damselflies (adults and larvae) collected from seven locations around Sapporo City, Japan, in 2016 and 2017. Fecal samples were plated on soybean casein digest (SCD) agar plates with and without antibiotics (SCD-A and SCD-w/o, respectively) to identify environmental bacteria and gut bacteria, respectively, and on MacConkey agar plates with antibiotics (MacConkey-A) to select for Gram-negative bacteria, including human pathogenic Enterobacterales species. The prevalence of colonies on each of the plates was compared, and representative colonies on MacConkey-A plates were identified to the species level using an API 20E kit and the MALDI Biotyper system. Overall, SCD-w/o plates showed a gut bacterial load of approximately 108 colony-forming units per adult damselfly or larva. There was a significant difference between the prevalence of colonies on the SCD-A and MacConkey-A plates, and a significantly increased prevalence of antibiotic-resistant bacteria on MacConkey-A plates was observed in samples collected from Shinoroshinkawa. Cluster analysis based on minimum inhibitory concentration values of 59 representative isolates from MacConkey-A agar plates revealed that samples from Shinoroshinkawa contained a higher prevalence of Enterobacterales than those from other sampling locations. Thus, fecal materials discharged by adult damselflies could be used in future studies as a simple tool for estimating antibiotic-resistant bacteria, including Enterobacterales species, in the local environment.
NOTAS SOBRE O VIÉS UTILITARISTA DA EDUCAÇÃO CONTEMPORÂNEA E O MODELO DA PAIDEIA
Authors: Brasileiro Fabiana Neiva Veloso , Lopes Marlo Renan Rocha , Martins José Clerton De Oliveira
Published: October 2018

O objetivo deste artigo é tecer algumas notas sobre o viés utilitarista da Educação na contemporaneidade e os valores caros à formação humana no modelo da Paideia, buscando, com esses apontamentos, problematizar o cenário educacional formal de hoje. Opta-se por uma abordagem qualitativa de cunho descritivo e exploratório, com uma revisão bibliográfica dos temas abordados: contemporaneidade, a Educação de viés utilitarista no contexto contemporâneo e a Educação grega clássica na perspectiva da Paideia. Discute-se que a Paideia resguarda determinados princípios norteadores de educação que podem ser de grande valia para se refletir sobre as práticas educativas atuais, muitas delas voltadas para o tecnicismo em detrimento de uma formação integral de ser humano.PALAVRAS-CHAVE: Contemporaneidade. Educação. Paideia.
NO LIMIAR DO FUTURO A ÉTICA PODE SER UM VETOR INDISPENSÁVEL PARA DISCUTIR A EDUCAÇÃO AMBIENTAL?
Authors: Prospere Renel , Nogaro Arnaldo , Battestin Cláudia
Published: October 2018

O presente artigo de natureza bibliográfica, busca abordar a ética e inseri-la como um vetor importante para discutir a questão de educação ambiental no âmbito atual. A ética nas relações cotidianas é imprescindível. Ela também se relaciona na sociedade no campo da economia, da política, da cultura e da natureza. Portanto, o objetivo deste trabalho visa mostrar, a importância da revisão e ampliação dos valores éticos para que possamos pensar em uma educação ambiental que tenha enquanto meta estimular o pensamento crítico e inovador, no seu espaço e tempo, tanto na perspectiva formal quanto na não formal. Tal educação deve gerar mudanças de pensamento e nas atitudes dos indivíduos em relação à natureza. Contudo, almeja-se que só uma mudança de paradigma de comportamento pode trazer essa mudança.
O ENSINO MÉDIO POLITÉCNICO FRENTE ÀS DEMANDAS E PERSPECTIVAS DOS ESTUDANTES
Authors: Munsberg João Alberto Steffen , Silva Gilberto Ferreira da
Published: October 2018

RESUMOEste trabalho tem por objetivo analisar a percepção de estudantes de escolas públicas estaduais do Rio Grande do Sul, sobre o atendimento de suas demandas pelo Ensino Médio Politécnico (EMP). A pesquisa abrangeu 30 escolas, uma de cada cidade-sede de Coordenadoria Regional de Educação (CRE), com 658 respondentes. No percurso metodológico utilizou-se a técnica de análise temática de Gibbs (2009), combinada com procedimentos de análise de conteúdo de Bardin (2011). Como resultados da pesquisa, constatou-se que os estudantes consideram o estudo e a escola importantes para sua formação, mas há um grande distanciamento entre a proposta oficial e sua implementação na realidade escolar.
O ENSINO DE LÓGICA ARTISTOTÉLICA NO ENSINO MÉDIO: UMA ABORDAGEM METODOLÓGICA SEGUNDO REFERENCIAIS VYGOTSKIANOS
Authors: Bitencourt Amauri Carboni , Hoeller Solange Aparecida de Oliveira
Published: October 2018

A lógica aristotélica é uma maneira de melhorarmos as formas de raciocínio, tanto da escrita quanto da oral. Abordamos este tema nos terceiros anos do ensino médio integrado de um Instituto Federal, mais especificamente nos cursos de Agropecuária, em 2015 e 2016. O objetivo foi possibilitar ao educando refletir, argumentar, escrever e falar de modo mais eficaz. Para tanto, consideramos como abordagem metodológica alguns referenciais da teoria vygotskiana (funções psicológicas superiores e a internalização destas; conceitos espontâneos e conceitos científicos; a mediação e a interação). O ensino de lógica aristotélica no ensino médio pode ser abordado segundo os referenciais teóricos tomados, pois permitem tratar e aprimorar o pensamento lógico formal.
Adding emotionality to seductive details—Consequences for learning?
Authors: Kühl Tim , Moersdorf Franziska , Römer Michelle , Münzer Stefan
Published: October 2018

According to the seductive detail effect, adding interesting but irrelevant information (i.e., seductive details) can be detrimental to learning success. In this study, it was explored within two experiments whether the valence of text‐based seductive details might affect learning outcomes differently. For Experiments 1 and 2, we pretested text‐based seductive details for their emotional valence (n = 32 or n = 25 students, respectively). For the main studies of Experiments 1 (n = 105) and 2 (n = 131), university students were randomly assigned to one of four conditions that varied with respect to the presence of seductive details and their emotional valence (no vs. positive vs. negative vs. neutral). Unexpectedly, results revealed in both experiments no seductive details effect and also no differences between the three seductive detail conditions for the used learning outcome measures retention and transfer. Possible reasons for these findings and their implications are discussed.
2D Metal Chalcogenide Nanopatterns by Block Copolymer Lithography
Authors: Yun Taeyeong , Jin Hyeong Min , Kim Dong‐Ha , Han Kyu Hyo , Yang Geon Gug , Lee Gil Yong , Lee Gang San , Choi Jin Young , Kim Il‐Doo , Kim Sang Ouk
Published: October 2018

Nanoscale structure engineering is in high demand for various applications of 2D transition metal dichalcogenides (TMDs). An edge‐exposed 2D polycrystalline MoS2 nanomesh thin film is demonstrated via block copolymer (BCP) nanopatterning. Molybdenum nanomesh structure is formed by direct metal deposition of hexagonal cylinder BCP nanotemplate and the following lift‐off process. Subsequent sulfurization of the molybdenum nanomesh creates MoS2 nanomesh thin films without any degradative etching step. The approach is applicable to not only other metal sulfides and oxides but also other nanoscale structures of TMD thin films including nanodot and nanowire array by means of various BCP nanotemplate shapes. As the edge site of MoS2 is highly active for NO2 sensing, the edge‐exposed MoS2 nanomesh demonstrates sevenfold enhancement of sensitivity for NO2 molecules compared to uniform thin film as well as superior reversibility even under 80% relative humidity environment. This structure engineering method could greatly strengthen the potential application of 2D TMD materials with the optimal customized nanoscale structures.
Organic Photovoltaic Sensors for Photocapacitive Stimulation of Voltage‐Gated Ion Channels in Neuroblastoma Cells
Authors: Abdullaeva Oliya S. , Balzer Frank , Schulz Matthias , Parisi Jürgen , Lützen Arne , Dedek Karin , Schiek Manuela
Published: October 2018

Organic semiconductors are emerging as promising candidates for novel electrically self‐sufficient photovoltaic prosthetics for neurostimulation, especially for restoration of light sensitivity in degenerate retina. Considering future applications, it is essential to gain fundamental insight into the signaling mechanisms at the organic photosensor–electrolyte–neuron interface. Particularly, targeting voltage‐gated ion channels by a pure photocapacitive stimulation is a preferred therapeutic approach as it avoids redox reactions involved in Faradaic charge injection. The present study investigates whether single neuroblastoma (N2A) cells, grown on a photosensor based on a small molecular squaraine:fullerene photoactive layer blend, optionally covered with silicon dioxide, can be activated by photocapacitive stimulation. Indeed, upon pulsed illumination, a rapid transient photocurrent strongly depolarizes the membrane potential and subsequently activates fast‐responding voltage‐gated sodium channels. The dielectric top coating on the organic layer ensures sufficient capacitive charge injection efficiency while maintaining the rapid response of the device. Due to the high irradiance level required for photocapacitive stimulation, another slower, independent, and unintended, nonelectrical signaling pathway is identified. This activates voltage‐gated potassium channels, presumably by photothermal effects. The present study provides the basis for further improvements on standalone photovoltaic neurostimulating platforms based on organic photoactive layers.
Micro–Nano‐Texturing Inner Surfaces of Small‐Caliber High Aspect Ratio and Superhydrophobic Artificial Vessels using Femtosecond Laser Filamenting Pulses
Authors: Zhan Xue‐Peng , Wang Yi‐Jun , Su Yue , Li Mu‐Tian , Zang Hong‐Wei , Xia Hong , Xu Huai‐Liang , Liu Bin , Sun Hong‐Bo
Published: October 2018

Cardiovascular diseases, the leading cause of death worldwide in the last two decades, are mainly due to the pathological changes inside the heart or blood vessels. Current treatment prescription is to replace obstructed blood vessels by synthetic alternatives, but it can only cure patients effectually when the vessel diameter is larger than a certain value because the cell attachment capacity on a small‐caliber artificial vessel is usually unacceptable for long‐term patency. Here a femtosecond filamenting laser‐based fabrication approach that can produce in situ microstructures on the inner surface of small‐caliber tubules is reported. It is shown that the inner‐surface fabrication with an aspect ratio as high as 10:1 can be achieved and the processed samples exhibit significant changes in physical properties including topography, roughness, hydrophobicity, as well as in biological property with improved ability for Hela cells to adhere and grow. The results provide a possibility toward fabricating small‐caliber artificial vessels that might be suitable for long‐term patency use.
Synthesis of Molybdenum–Tungsten Bimetallic Carbide Hollow Spheres as pH‐Universal Electrocatalysts for Efficient Hydrogen Evolution Reaction
Authors: Lin Lifeng , Chen Min , Wu Limin
Published: October 2018

Development of highly efficient non‐noble metal electrocatalysts to replace platinum for hydrogen evolution reaction (HER) has attracted tremendous attention in recent years. In this work, a kind of novel MoxW2−xC@C hollow spheres with tunable stoichiometry is successfully synthesized. The synergetic effect of appropriate W‐introducing and hollow structure enables the composites to have superior performance for electrocatalytic HER and long‐term stability in a wide pH range. The MoxW2−xC@C with an optimized Mo/W ratio of 1.26/0.74 exhibits an overpotential (η10) of 106, 127, and 152 mV at 10 mA cm−2 in 1 m KOH, 0.5 m H2SO4, and 1 m phosphate buffer saline (PBS), respectively, and its overpotential in high current density region (η300) is only 237 and 250 mV in alkaline and acidic electrolytes, which are significantly better than most of the previously reported electrocatalysts.
Activated‐Carbon‐Supported Calcium Oxide: A Selective and Efficient Catalyst for Nitrile‐Containing Diaryl Ether Synthesis
Authors: Han Yue , Wang Guangxing , Qiu Wenfeng , Guo Ying , Sun Yanan , Zhang Youlan , Zhou Heng , Zhao Tong
Published: October 2018

Activated‐carbon‐supported calcium oxide (CaO@AC) was prepared from AC and a suspension derived from CaO and ammonium carbonate. After calcination under nitrogen, high purity CaO@AC was obtained. The nature of non‐aggregation and high purity of CaO@AC enabled a clean and selective synthesis protocol for nitrile‐containing diaryl ethers. Various functional groups including methoxyl, amino, carboxyl, allyl and nitro were well‐tolerated, and products were obtained in excellent yields and purities. Asymmetric substitutions could be achieved via simple adjustment of reaction conditions, and transetherification was greatly suppressed to 10−3–10−4 scale. In addition, a mechanism for suppression in transetherification was proposed and discussed.
Selbstanordnung von BODIPY‐Farbstoffen als Werkzeug, um die Antitumoraktivität von Capsaicin bei Prostatakrebs zu erhöhen
Authors: Sampedro Angel , Ramos‐Torres Ágata , Schwöppe Christian , Mück‐Lichtenfeld Christian , Helmers Ingo , Bort Alicia , Díaz‐Laviada Inés , Fernández Gustavo
Published: October 2018

Capsaicin (CAP) ist seit Längerem für dessen analgetische Wirkung sowie seit Kurzem für seine Antitumoraktivität an verschiedenen Zelltypen bekannt. Aufgrund seiner Schärfe und der benötigten hohen Dosen zur Erzielung einer signifikanten Aktivität hat dieser Wirkstoff bis heute keine Anwendung in der Krebstherapie gefunden. In dieser Arbeit zeigen wir eine neuartige Strategie, um die Aktivität dieses Wirkstoffes zu verbessern. Durch den Austausch der hydrophoben Terpeneinheit durch einen BODIPY‐Farbstoff wurde die Neigung zur Aggregation erhöht. Die Verbindung CAP‐BDP 1 lagert sich in wässrigen Medien zu schwach fluoreszierenden sphärischen Anordnungen zusammen, die durch die Aufnahme in die Zelle zur hoch fluoreszierenden Monomereinheiten disassemblieren. Bemerkenswert ist, dass der Transport in das Tumorgewebe mithilfe dieser Aggregate verbessert werden und somit die wirksame Dosis in vivo bei Prostatakrebszellen um zwei Größenordnungen reduziert werden konnte.
Quadruply Twisted Hückel‐Aromatic Dodecaphyrin
Authors: Soya Takanori , Mori Hirotaka , Osuka Atsuhiro
Published: October 2018

Molecular topology of π‐conjugated circuits becomes increasingly important in the chemistry of aromatic and antiaromatic compounds. meso‐Pentafluorophenyl‐substituted 5,35‐(1,4‐phenylene)bridged [56]dodecaphyrin was synthesized by condensation of 1,4‐phenylene‐bridged dicarbinol dimer and 5,10,15‐tris‐(pentafluorophenyl)tetrapyrrane followed by oxidation with DDQ and was oxidized to its [54]‐ and [52]congeners in a stepwise manner. Metalation of the [52]dodecaphyrin with Pd2(dba)3 gave two bis‐PdII complexes that are isomers of metalation sites: anti and syn with regard to the 1,4‐phenylene bridge. The anti‐isomer was easily oxidized to its N‐fused form, a quadruply twisted non‐aromatic or weakly aromatic macrocycle. On the other hand, the syn‐isomer was revealed to be the first example of Hückel aromatic molecule with a quadruply twisted structure.
Palladium‐Catalyzed C−H Alkenylation of Arenes with Alkynes: Stereoselective Synthesis of Vinyl Chlorides via a 1,4‐Chlorine Migration
Authors: Li Zhen , Duan Wei‐Liang
Published: October 2018

A directing group‐free, ligand‐promoted palladium‐catalyzed C−H arylation of internal alkynes with simple arenes was developed. Alkenyl chlorides resulting from a 1,4‐chlorine migration or trisubstituted alkenes were produced in moderate to good yields depending on the type of alkyne.
Facile Synthesis of Sequence‐Regulated Synthetic Polymers Using Orthogonal SuFEx and CuAAC Click Reactions
Authors: Yang Cangjie , Flynn James P. , Niu Jia
Published: October 2018

The orthogonal sulfur–fluoride exchange reaction (SuFEx) and copper(I)‐catalyzed azide–alkyne cycloaddition (CuAAC) are employed to synthesize sequence‐regulated synthetic polymers. The high efficiency and broad tolerance of SuFEx and CuAAC to diverse chemical functionalities enable the one‐pot synthesis of polydispersed sequence‐controlled polymers by step‐growth copolymerization in high yield and sequence complexity. Furthermore, iterative SuFEx and CuAAC coupling reactions on a solid support, without the need of protecting groups, afford monodispersed sequence‐defined oligomers. The use of this orthogonal pair of click reactions provides new opportunities to facilely access sequence‐regulated synthetic polymers with a high degree of structural diversity.
Platinum‐Catalyzed Desaturation of Lactams, Ketones, and Lactones
Authors: Chen Ming , Rago Alexander J. , Dong Guangbin
Published: October 2018

The development of a general platinum‐catalyzed desaturation of N‐protected lactams, ketones, and lactones to their conjugated α,β‐unsaturated counterparts is reported. The reaction operates under mildly acidic conditions at room temperature or 50 °C. It is scalable and tolerates a wide range of functional groups. The complementary reactivity to the palladium‐catalyzed desaturation is demonstrated in the efficient conversion of iodide, bromide, and sulfur‐containing substrates.
Rapid Structure Determination of Microcrystalline Molecular Compounds Using Electron Diffraction
Authors: Gruene Tim , Wennmacher Julian T. C. , Zaubitzer Christan , Holstein Julian J. , Heidler Jonas , Fecteau‐Lefebvre Ariane , De Carlo Sacha , Müller Elisabeth , Goldie Kenneth N. , Regeni Irene , Li Teng , Santiso‐Quinones Gustavo , Steinfeld Gunther , Handschin Stephan , van Genderen Eric , van Bokhoven Jeroen A. , Clever Guido H. , Pantelic Radosav
Published: October 2018

Chemists of all fields currently publish about 50 000 crystal structures per year, the vast majority of which are X‐ray structures. We determined two molecular structures by employing electron rather than X‐ray diffraction. For this purpose, an EIGER hybrid pixel detector was fitted to a transmission electron microscope, yielding an electron diffractometer. The structure of a new methylene blue derivative was determined at 0.9 Å resolution from a crystal smaller than 1×2 μm2. Several thousand active pharmaceutical ingredients (APIs) are only available as submicrocrystalline powders. To illustrate the potential of electron crystallography for the pharmaceutical industry, we also determined the structure of an API from its pill. We demonstrate that electron crystallography complements X‐ray crystallography and is the technique of choice for all unsolved cases in which submicrometer‐sized crystals were the limiting factor.
Bioproducts from wheat gluten with high strength and aqueous stability using cashew nut shell liquid as plasticizer
Authors: Guna Vijaykumar , Ilangovan Manikandan , Nataraj Divya , Reddy Narendra
Published: October 2018

Cashew nut shell liquid (CNSL) provides wheat gluten films with mechanical properties similar to but considerably higher resistance to water than glycerol‐plasticized films. Obtaining biopolymeric films with good water stability without using synthetic polymers or extensive chemical modifications is a challenge. Wheat gluten is a preferred protein for manufacturing films for food and nonfood applications, but obtaining water‐stable gluten films is difficult. Glycerol and other plasticizers have been extensively used to develop films, but these plasticizers inevitably decrease strength and resistance to water. CNSL is a byproduct obtained during processing of cashew nuts and is available in large quantities at low cost. In this research, we studied the possibility of substituting CNSL for glycerol as the plasticizer for wheat gluten films. Wheat gluten was compression molded into films with 10%, 20%, or 30% CNSL or glycerol, and the changes in mechanical properties, stability in water, thermal behavior, and surface wettability were determined. It was observed that CNSL provided similar strength, 80 to 100 times higher modulus, and considerably higher resistance to water but lower elongation compared to glycerol‐treated films. It was possible to obtain films with the desired mechanical properties and water stability by controlling the amount of CNSL and processing conditions. Wheat gluten can be converted into completely biodegradable cups, containers, coffee pods, and other bioproducts using this approach. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46719.
Photodegradation of copolyester films: A mechanistic study
Authors: Arangdad Kiarash , Detwiler Andrew , Cleven Curtis D. , Burk Christopher , Shamey Renzo , Pasquinelli Melissa A. , Freeman Harold , El‐Shafei Ahmed
Published: October 2018

The photodegradation of copolyesters based on 1,4‐cyclohexanedimethanol (CHDM), tetramethyl‐1,3‐cyclobutanediol, and terephthalic acid units was investigated using various analytical methods. Photodegradation products were characterized using Fourier transform infrared (FTIR), liquid chromatography–mass spectrometry (LC–MS), and X‐ray Photoelectron spectroscopy (XPS) analysis. The homolytic scission of C‐O bonds of ester groups through a Norrish Type I reaction was supported by time of flight secondary ion mass spectrometry and LC–MS results, while nuclear magnetic resonance analysis confirmed hydrogen abstraction from the tertiary carbon of CHDM units in the trans (equatorial‐equatorial) conformation. Chain scission through Norrish Type II reaction is also responsible for the formation of carboxylic acid end group. Fluorescence emission from irradiated glycol modified poly(ethylene terephthalate) films demonstrated the formation of mono‐ and dihydroxyterephthalate species. Furthermore, FTIR and XPS valence band analysis confirmed configurational changes, in the polymer chain due to photodegradation. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47148.
Characterization of different forms of vulcanized natural rubbers as elastomer spacer and toughening agent in two‐matrix filled epoxy/natural rubber/graphene nano‐platelets system
Authors: Kam Ka Wei , Teh Pei Leng , Osman Hakimah , Yeoh Cheow Keat
Published: October 2018

This paper compares the effects of different forms of vulcanized natural rubbers on the physical, mechanical, thermal, and electrical performances of filled epoxy systems. In this study, natural rubber (NR), liquid natural rubber (LNR), and recycled natural rubber (rNR) were introduced into filled epoxy systems. The results show that flexural strength, modulus, and toughness properties of filled epoxy system were enhanced with NR phases, as compared to those with LNR and rNR. Scanning electron micrograph revealed that the particle sizes of NR phases dispersed within epoxy matrix were smaller and more uniform, as compared to those with LNR and rNR phases. Incorporation of NR phases has improved the thermal stability of filled system, followed by LNR and rNR. This is attributed to more heat energy needed to overcome good interfacial bonding between epoxy matrix and small NR phases. X‐ray diffraction analysis result showed that filled epoxy/NR/GNP system has higher 2θ values, indicated that d‐spacing in between GNP nano‐fillers has the closer distance. Electrical bulk conductivity values of filled epoxy/NR/GNP system were the highest. Small NR phases acted as elastomer spacers, which provided better “GNP packing efficiency” and realigned the GNP nano‐fillers to form more effective conductive pathways for electrons hopping. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47188.
Discrete Fractional‐Order BAM Neural Networks with Leakage Delay: Existence and Stability Results
Authors: Alzabut Jehad , Tyagi Swati , Abbas Syed
Published: October 2018

In this paper, a discrete model of fractional‐order bidirectional associative memory (BAM) neural networks with leakage delay is considered. Sufficient conditions are established for the existence, uniqueness and uniform stability of nontrivial solutions of the addressed model. Our approach is based on the implementation of the newly defined discrete fractional calculus, mathematical inequalities and fixed point theorems. We provide an example that supports the application of the theoretical results.
Zeolitic Imidazolate Framework‐Derived Core‐Shell‐Structured CoS2/CoS2‐N‐C Supported on Electrochemically Exfoliated Graphene Foil for Efficient Oxygen Evolution
Authors: Cao Junhui , Lei Chaojun , Yang Bin , Li Zhongjian , Lei Lecheng , Hou Yang , Feng Xinliang
Published: October 2018

Developing earth‐abundant transition‐metal based materials to efficiently catalyze the oxygen evolution reaction (OER) is an urgent demand for electrochemical water splitting and rechargeable metal‐air batteries. Here, we developed a novel 3D hybrid electrocatalyst consisting of core‐shell structured CoS2/CoS2 embedded into N‐doped carbon supported on electrochemically exfoliated graphene foil (EG/CoS2/CoS2‐NC) by sulfurization treatment of EG/Co(OH)2/zeolitic imidazolate framework‐67 (ZIF‐67) as precursor. The thickness of the CoS2‐NC shell derived from ZIF‐67 is 10 nm and the CoS2 core generated from Co(OH)2 nanosheet arrays has a particle size of ∼20 nm. Benefiting from the unique 3D core‐shell structure and synergistic effects, the EG/CoS2/CoS2‐NC hybrid enormously promotes electrocatalytic OER activity with a low overpotential of 210 mV at a current density of 10 mA cm−2 and a small Tafel slope of 61.9 mV dec−1. These values are far superior compared to the commercial Ir/C catalyst, and even better than other reported state‐of‐the‐art CoS2‐based materials. In‐situ Raman spectroscopy together with ex‐situ XRD patterns reveal that the active centers of EG/CoS2/CoS2‐NC hybrid are proven to be Co‐OOH species that are derived from Co−S groups during the OER process. The superb catalytic performance is also reflected in boosting electrochemical urea oxidation and hydrazine oxidation, where the accelerated oxidation reaction could be observed.
Consumer familiarity, ambiguity tolerance, and purchase behavior toward remanufactured products: The implications for remanufacturers
Authors: Wang Shanyong , Wang Jing , Yang Feng , Wang Yu , Li Jun
Published: October 2018

Remanufacturing plays an important role in reducing energy consumption and material usage. The present research attempted to understand consumers' perceptions of remanufactured products in China and their resulting purchase behavior. The study uses the theory of planned behavior as its theoretical framework but extends it by incorporating two additional variables (consumer familiarity and ambiguity tolerance). Data was collected using a self‐administered questionnaire survey and analyzed with structural equation modeling. According to the survey findings, consumer familiarity positively affects consumer attitude but negatively affects consumer intention to purchase remanufactured products. Ambiguity tolerance positively affects attitude and purchase intention. Meanwhile, consumer attitude and perceived behavioral control are both positively and significantly related to purchase intention. However, the subjective norm has no significant effect on purchase intention. This study also demonstrated the positive effect of purchase intention on actual purchase behavior. Based on the research findings, practical guidelines are given for remanufacturers to motivate consumers to purchase remanufactured products.
The impact of market structure on environmental efficiency in the United States: A quantile approach
Authors: Halkos George E. , Polemis Michael L.
Published: October 2018

This paper investigates the relationship between efficiency and market structure for a sample of industrial facilities dispersed among the U.S. states. In order to measure the relevant efficiency scores, we use a data envelopment analysis allowing for the inclusion of desirable and undesirable (toxic chemical releases) outputs in the production function. In the next stage, we utilize the bootstrapped quantile regression methodology to uncover possible nonlinear relationships between efficiency and competition at the mean and at various quantiles before and after the global financial crisis (2002 and 2012). In this way, we impose no functional form constraints on parameter values over the conditional distribution of the dependent variable (efficiency). At the same time, we estimate at which part of its cumulative distribution function the efficiency is located and draw substantial conclusions about the range of policy measures obtained. The empirical findings indicate that the relationship between efficiency and market concentration did change in the aftermath of the global financial crisis. The empirical results survived robustness checks under the inclusion of an alternative market concentration indicator (CR8).
Systematic Modulation of the Supramolecular Gelation Properties of Bile Acid Alkyl Amides
Authors: Kuosmanen Riikka , Puttreddy Rakesh , Rissanen Kari , Sievänen Elina
Published: October 2018

The self‐assembly properties of nine low‐molecular‐weight gelators (LMWGs) based on bile acid alkyl amides were studied in detail. Based on the results, the number of hydroxyl groups attached to the steroidal backbone plays a major role in the gelation, although the nature of the aliphatic side chain also modulates the gelation abilities. Of the 50 gel systems studied, 35 are based on lithocholic acid and 15 on cholic acid derivatives. The deoxycholic acid derivatives did not form any gels. The gelation occurred primarily in aromatic solvents and the gels manifested typical fibrous or spherical morphologies. The 13C cross‐polarized magic angle spinning (CPMAS) NMR spectra measured on the crystalline materials and the corresponding wet organogels were analogous, suggesting that the chemical environments, that is, the intermolecular interactions found in the two materials were similar. The single‐crystal X‐ray structures of all nine bile‐acid amide derivatives studied revealed very similar molecular conformations in the solid state and gave insights into the possible intermolecular interactions in the gel state.
Facile Preparation of Nanofibrillar Networks of “Ureido‐Chitin” Containing Ureido and Amine as Chelating Functional Groups
Authors: Ganesan Kathirvel , Heyer Markus , Ratke Lorenz , Milow Barbara
Published: October 2018

Aerogels of polysaccharides with chelating functions can be useful as supports in many applications because of their hosting properties. This work demonstrates a facile method for the preparation of aerogels of chitosan derivative “ureido‐chitin”, containing ureido functional groups. The nanofibrillar networks of “ureido‐chitin” were produced by the nucleophilic addition of amine groups of chitosan with isocyanic acid prepared in situ. The presence of ureido functional groups was confirmed by FTIR, solid‐state CP‐MAS 13C and 15N NMR analyses. No crosslinking of molecular chains was observed. The maximum degree of ureido functional groups was estimated to be about 66 %. Characterization by powder XRD confirmed that the polymer chains self‐assembled, with the chitin polymers oriented in a highly ordered crystalline structure. The nanofibrillar networks showed no solubility under either aqueous acidic or alkaline conditions. Bio‐based hosting materials of this kind with two different hosting functional groups, ureido and amine, can potentially be utilized for a wide range of applications in aqueous medium, including filters, catalysis and biomedicine.
Pharmacokinetics of Tenofovir Alafenamide, Tenofovir, and Emtricitabine Following Administration of Coformulated Emtricitabine/Tenofovir Alafenamide in Healthy Japanese Subjects
Authors: Yamada Hiroyuki , Yonemura Takuma , Nemoto Takanori , Ninomiya Noriko , Irie Shin
Published: October 2018

A fixed‐dose combination of tenofovir alafenamide (TAF) and emtricitabine (FTC) is available in 2 tablet strengths in Japan (FTC/TAF 200/10 mg and FTC/TAF 200/25 mg). These are used once daily in combination with other antiretroviral agents for the treatment of human immunodeficiency virus type 1 infection. The primary objective of this study was to investigate if there is any clinically relevant pharmacokinetic difference for TAF, tenofovir (TFV), and FTC between Japanese and non‐Japanese with historical data. Three treatment groups were set in the study; FTC/TAF 200/10 mg in combination with darunavir (DRV) 800 mg + ritonavir (RTV) 100 mg (treatment A) or DRV/cobicistat (COBI) 800/150 mg (treatment B) and FTC/TAF 200/25 mg alone (treatment C). Especially for treatment C, it was designated for another purpose to evaluate the pharmacokinetic boosting effects of RTV and COBI on TAF bioavailability. As a result, the mean exposure of TAF among treatment groups was 125 to 154 ng/mL for Cmax and 119 to 179 ng·h/mL for AUCinf, which were comparable with the historical data in non‐Japanese. The exposures of TFV and FTC were also consistent with the historical data. Therefore, no clinically relevant pharmacokinetic differences for TAF, TFV, and FTC were observed between Japanese and non‐Japanese. Boosting effects of RTV and COBI on TAF bioavailability were slightly lower than we expected, less than a 2.5‐fold increase, but it was within the range of exposures associated with efficacy and safety in phase 3 studies. Therefore, it was not considered clinically relevant.
Bioequivalence of Sarpogrelate in Healthy Chinese Subjects Under Fasting and Fed Conditions: A 4‐Way Replicate Crossover Investigation by a Reference‐Scaled Average Bioequivalence Approach
Authors: Ding Y.H. , Liu B. , Lou J.F. , Sun J.X. , Wu M. , Zhu X.X. , Chen G.L. , Zhang H. , Li X.J. , Chen H. , Liu C.J. , Shen Z.W. , Li C.Y.
Published: October 2018

Sarpogrelate is widely used to treat peripheral vascular disorders. However, it has been demonstrated to have a poor pharmacokinetic (PK) profile and marked within‐subject variability. Here, the bioequivalence of 2 formulations of sarpogrelate (100‐mg tablets) was assessed by using the reference‐scaled average bioequivalence (RSABE) method, and the PK parameters were quantified in healthy Chinese subjects under fasting (n = 38) and fed (n = 35) conditions. In this open and randomized 4‐way replicate study, a single dose of sarpogrelate was administered followed by a 3‐day washout period. The sarpogrelate concentration in blood samples was measured by liquid chromatography‐tandem mass spectrometry within 6 hours (fasting) or 10 hours (fed) of drug administration, and the PK parameters were determined by a noncompartmental model. The bioequivalence of the 2 formulations under both conditions was assessed using the ratios of ln(peak concentration [Cmax]) and ln(area under the concentration‐time curve [AUC]) within the limits based on the RSABE method. The 90% CIs for the ratios of lnCmax, lnAUC0‐t, and lnAUC0‐∞ were 0.8531–1.1100, 0.9616–1.0737, and 0.9550–1.0684, respectively, under fasting conditions and 0.8918–1.1076, 0.9818–1.0694, and 0.9818–1.0686, respectively, under fed conditions, which were within the RSABE acceptance limits. Food intake decreased the systemic exposure and the Cmax of sarpogrelate by 0.9‐fold and 0.5‐fold, respectively.
Three‐dimensional sound reproduction in vehicle based on data mining technique
Authors: Zhang Maosheng , Hu Ruimin , Jiang Lin
Published: October 2018

Three‐dimensional (3D) audio reproduction technique is a hot topic since MPEG proposed a proposal for 3D audio standard in 2012. The present 3D reproduction method is not available in vehicle because the loudspeaker configuration does not meet the requirements of the methods. In this paper, we develop a regression model to reproduce sound pressure in vehicle using a data mining algorithm. A big sound pressure dataset is established based on acoustic theory. We analyze this dataset and propose a stepwise regression model training and testing on this dataset. Both the Mean Square Error and Root Mean Square Error are rather small, and all the residuals such as raw residuals, Pearson Residuals, Studentized residuals, and Standardize residuals are small as well. The experiments indicate that the proposed reproduction system accurately simulates the theoretical sound reproduction system.
An incentive mechanism for crowdsourcing markets with social welfare maximization in cloud‐edge computing
Authors: Xu Xiaolong , Cai Qing , Zhang Guoming , Zhang Jie , Tian Wei , Zhang Xiaorui , Liu Alex X.
Published: October 2018

Crowdsourcing is emerging as a powerful paradigm that utilizes the distributed devices to sense, collect, and upload data to satisfy the requirements of the users. Currently, with the popularity of edge computing, edge device users can act as recruiters or participants to publish or perform crowdsourcing tasks and share feedback. However, due to the individual selfishness, it is still a challenge to maximize the social welfare distribution of all the participants and the recruiters for the crowdsourcing market. In view of this challenge, an incentive mechanism for the crowdsourcing market with social welfare maximization in the cloud‐edge computing is designed in this paper. Technically, a double action model under the cloud‐edge computing framework is proposed first, which aims to maximize the social welfare maximization and meanwhile meet the demands of incentive compatibility, individual rationality, market clearing, and budget constraint. Secondly, a corresponding incentive mechanism is designed based on the double auction model to achieve the market fairness. Experimental evaluation and comparison analysis are conducted to validate the efficiency and effectiveness of the mechanism.
Statistical analysis of cloud characteristics in Northwest China based on Fengyun satellite data
Authors: Zhao Mengyue , Wu Jiaji , Jeon Gwanggil , Guo Xing
Published: October 2018

The northwest region in China located at arid and semiarid areas, atmospheric precipitation converted by the cloud is an important part of water resources, and if we fully utilize cloud for cloud‐water conversion to alleviate the scarcity of water, thereby it is particularly important to analyze the macroscopic characteristics and the changing trends of clouds in the northwest region. In this paper, the 2016 Level 1 data of Fengyun Satellite has been calibrated, corrected, and processed, using the improved multi‐spectral thresholding method to calculate cloud coverage and cloud classification data. The optical thickness inversion uses the SBDART (Santa Barbara DISORT Atmospheric Radiative Transfer) radiation transmission mode to establish a radiation look‐up table with optical thickness as a function variable under different conditions of observation geometry, underlying surface type, and atmospheric environment. The results show that the coverage of clouds in the northwest region accounts for about 45%, and the cloud coverage changes with the seasons. The classification of clouds mainly consists of high clouds, low clouds, and cumulonimbus. The optical thickness of clouds is largely distributed between 10 and 25.
LAR: Locality‐Aware Reconstruction for erasure‐coded distributed storage systems
Authors: Xu Fangliang , Wang Yijie , Pei Xiaoqiang , Ma Xingkong
Published: October 2018

Many modern distributed storage systems adopt erasure coding to protect data from frequent server failures for cost reason. Reconstructing data in failed servers efficiently is vital to these erasure‐coded storage systems. To this end, tree‐structured reconstruction mechanisms where blocks are transmitted and combined through a reconstruction tree have been proposed. However, existing tree‐structured reconstruction mechanisms build reconstruction trees from the perspective of available network bandwidths between servers, which are fluctuating and difficult to measure. Besides, these reconstruction mechanisms cannot reduce data transmission. In this study, we overcome these limitations by proposing LAR, a locality‐aware tree‐structured reconstruction mechanism. LAR builds reconstruction trees from the perspective of data locality, which is stable and easy to obtain. More importantly, by building reconstruction trees that combine blocks closer to each other first, LAR can reduce the data transmitted through the network core and hence speed up reconstruction. We prove that a minimum spanning tree is an optimal reconstruction tree that minimizes core bandwidth usage. We also design and implement a general reconstruction framework that supports all tree‐structured reconstruction mechanisms and nearly all erasure codes. Large‐scale simulations on commonly deployed network topologies show that LAR consumes 20%–61% less core bandwidth than previous reconstruction mechanisms. Thorough experiments on a testbed consisting of 40 physical servers show that LAR improves proactive recovery throughput by 23% at least and improves degraded read rate by up to 68%.
Optimal matching between energy saving and traffic load for mobile multimedia communication
Authors: Chehri Abdellah , Jeon Gwanggil
Published: October 2018

Optimizing cell locations of cellular networks is one of the most fundamental problems of network design. However, in order to meet a growing appetite for mobile data services, a large number of base stations are being deployed, which leads to tremendous energy consumption in cellular networks. This augmentation increases not only the system's capital and operational expenditure (CAPEX/OPEX) for mobile operators but also CO2 emissions. Besides the issue of meeting overwhelming traffic demands, network operators around the world now realize the importance of managing their cellular networks in an energy‐efficient manner. In this paper, we develop a self‐organizing framework for energy saving in orthogonal frequency‐division multiple‐access–based cellular access networks. We consider three different objectives, namely, coverage maximization, overlap minimization, and power consumption minimization, which is different from all existing works on energy saving in cellular networks.
Derivation of Specific Neural Populations From Pluripotent Cells for Understanding and Treatment of Spinal Cord Injury
Authors: White Nicholas , Sakiyama‐Elbert Shelly E.
Published: October 2018

Due to the nature of the biological response to traumatic spinal cord injury, there are very limited therapeutic options available to patients. Recent advances in cell transplantation have demonstrated the therapeutic potential of transplanting supportive cell types following spinal cord injury. In particular, pluripotent stem cell derived neural cells are of interest for future investigation. Use of pluripotent stem cells as the source allows many cell types to be produced from a population that can be expanded in vitro. In this review, we will discuss the signaling pathways that have been used to differentiate spinal neural phenotypes from pluripotent stem cells. Additionally, we will highlight methods that have been developed to direct the differentiation of pluripotent stem cells to specific neural fates. Further refinement and elaboration of these techniques might aid in elucidating the multitude of neuronal subtypes endogenous to the spinal cord, as well as produce further therapeutic options for spinal cord injury recovery. Developmental Dynamics 248:78–87, 2019. © 2018 Wiley Periodicals, Inc.