bluuebunny/crossref_metadata_2025_split huggingface dataset:
Molecular characterization of clonal lineage and staphylococcal toxin genes fromS. aureusin Southern Nigeria
Authors: Ayeni Funmilola A. , Ruppitsch Werner , Allerberger Franz 
Published: July 2018

BackgroundStaphylococcus aureusis a human colonizer with high potential for virulence, and the spread of the virulent strains from the colonized hosts to non-carriers in the community is on the increase. However, there are few reports on comprehensive analysis of staphylococcal enterotoxin (SE) genes with clonal lineage inS. aureusin Africa. This is essential because of diversity of cultures and habits of the people. This study analyzed spa types and enterotoxin genes inS. aureusstrains previously isolated from the human nostrils, poultry and clinical samples in Southern Nigeria.MethodsForty-sevenS. aureusisolates were obtained from humans nostrils (n = 13), clinical strains (n = 21) and poultry (n = 13) from previous studies in Southern Nigeria. The strains were analyzed formecAgene, selected toxins genes (sea, seb, sec, sed, see, seg, seh, sei, sej, sek, sel, sem, sen, seo, sep, seq, ser, seu)and Panton-Valentine leukocidin (PVL) gene(lukS-PV/lukF-PV)by PCR. Population structures of the strains were detected by Staphylococcal protein A (spa) typing.ResultsTwenty different spa types were obtained with the highest percentages, 17% observed inspatype t091 from clinical, nasal and poultry samples while t069 was the most prevalent spa type in poultry. Two MRSA were only detected in human strains. The poultry strains had the highest occurrence of SE genes (18%) followed by nasal strains (15%) and clinical strains (10%). Eighty-nine percent of all tested isolates harbored at least one SE gene;seowas the most prevalent (34%) followed byseg(30%) andsea(21%), whilesec, seeandsejwere absent in all strains. Spa type t355 was associated withlukS-PV/lukF-PVgene and complete absence of all studied SE.Sea, seq, seb, sekwere associated with spa type t069;seawas associated with t127 whilesepwas associated with spa type t091. There were coexistences ofseo/segandsei/seg.ConclusionsThe higher carriage of staphylococci enterotoxin genes by the nasal and poultryS. aureusstrains suggests a high potential of spread of staphylococcal food poisoning through poultry and healthy carriers in the community. This is the first report of high occurrence of staphylococcal enterotoxins genes in poultry from Nigeria.
Fostering learning from instructional video in a second language
Authors: Lee Hyunjeong , Mayer Richard E. 
Published: July 2018

SummaryThis study investigated the most effective way to present an instructional video that contains words in the students' second language. Korean‐speaking university students received a 16‐min video lesson on Antarctica that included English narration (video + narration group), English text subtitles (video + text group), or English narration with simultaneous text subtitles (video + narration + text group). On a comprehension test, the video + text group scored higher than each of the other two groups, in contrast to the modality effect; and the video + narration + text group outscored the video + narration group, in contrast to the redundancy effect. Each of the lessons that included text was rated as less difficult than the lesson with narration only. The narration + text group reported lower effort than each of the other groups. Results highlight boundary conditions for two principles of multimedia instructional design that apply for college students who are learning in a second language. Theoretical implications are discussed.
Plasmonic Au/TiO2‐Dumbbell‐On‐Film Nanocavities for High‐Efficiency Hot‐Carrier Generation and Extraction
Authors: Ho Kwun Hei Willis , Shang Aixue , Shi Fenghua , Lo Tsz Wing , Yeung Pui Hong , Yu Yat Sing , Zhang Xuming , Wong Kwok‐yin , Lei Dang Yuan 
Published: July 2018

AbstractPlasmon‐induced hot carriers have vast potential for light‐triggered high‐efficiency carrier generation and extraction, which can overcome the optical band gap limit of conventional semiconductor‐based optoelectronic devices. Here, it is demonstrated that Au/TiO2 dumbbell nanostructures assembled on a thin Au film serve as an efficient optical absorber and a hot‐carrier generator in the visible region. Upon excitation of localized surface plasmons in such coupled particle‐on‐film nanocavities, the energetic conduction electrons in Au can be injected over the Au/TiO2 Schottky barrier and migrated to TiO2, participating in the chemical reaction occurring at the TiO2 surface. Compared with the same dumbbell nanostructures on an indium tin oxide (ITO) film, such nanocavities exhibit remarkable enhancement in both photocurrent amplitude and reaction rate that arise from increased light absorption and near‐field amplification in the presence of the Au film. The incident‐wavelength‐dependent photocurrent and reaction rate measurements jointly reveal that Au‐film‐mediated near‐field localization facilitates more efficient electron–hole separation and transport in the dumbbells and also promotes strong d‐band optical transitions in the Au film for generation of extra hot electrons. Such nanocavities provide a new plasmonic platform for effective photoexcitation and extraction of hot carriers and also better understanding of their fundamental science and technological implications in solar energy harvesting.
Magnetically Recyclable Catalytic Carbon Nanoreactors
Authors: Aygün Mehtap , Chamberlain Thomas W. , Gimenez‐Lopez Maria del Carmen , Khlobystov Andrei N. 
Published: July 2018

AbstractMultifunctional nanoreactors are assembled using hollow graphitized carbon nanofibers (GNFs) combined with nanocatalysts (Pd or Pt) and magnetic nanoparticles. The latter are introduced in the form of carbon‐coated cobalt nanomagnets (Co@Cn) adsorbed on GNF, or formed directly on GNF from ferrocene yielding carbon‐coated iron nanomagnets (Fe@Cn). High‐resolution transmission electron microscopy demonstrates that Co@Cn and Fe@Cn are attached effectively to the GNFs, and the loading of nanomagnets required for separation of the nanoreactors from the solution with an external magnetic field is determined using UV–vis spectroscopy. Magnetically functionalized GNFs combined with palladium or platinum nanoparticles result in catalytically active magnetically separable nanoreactors. Applied to the reduction of nitrobenzene the multifunctional nanoreactors demonstrate high activity and excellent durability, while their magnetic recovery enables significant improvement in the reuse of the nanocatalyst over five reaction cycles (catalyst loss < 0.5 wt%) as compared to the catalyst recovery by filtration (catalyst loss <10 wt%).
Dirac Semimetal Heterostructures: 3D Cd3As2 on 2D Graphene
Authors: Wu Yan‐Fei , Zhang Liang , Li Cai‐Zhen , Zhang Zhen‐Sheng , Liu Song , Liao Zhi‐Min , Yu Dapeng 
Published: July 2018

AbstractDirac semimetal is an emerging class of quantum matters, ranging from 2D category, such as, graphene and surface states of topological insulator to 3D category, for instance, Cd3As2 and Na3Bi. As 3D Dirac semimetals typically possess Fermi‐arc surface states, the 2D–3D Dirac van der Waals heterostructures should be promising for future electronics. Here, graphene–Cd3As2 heterostructures are fabricated through direct layer‐by‐layer stacking. The electronic coupling results in a notable interlayer charge transfer, which enables us to modulate the Fermi level of graphene through Cd3As2. A planar graphene p–n–p junction is achieved by selective modification, which demonstrates quantized conductance plateaus. Moreover, compared with the bare graphene device, the graphene–Cd3As2 hybrid device presents large nonlocal signals near the Dirac point due to the charge transfer from the spin‐polarized surface states in the adjacent Cd3As2. The results enrich the family of van der Waals heterostructure and should inspire more studies on the application of Dirac/Weyl semimetals in spintronics.
Boron Embedded in Metal Iron Matrix as a Novel Anode Material of Excellent Performance
Authors: Dong Wujie , Zhao Yantao , Wang Xin , Yuan Xiaotao , Bu Kejun , Dong Chenlong , Wang Ruiqi , Huang Fuqiang 
Published: July 2018

AbstractBoron, the most ideal lithium‐ion battery anode material, demonstrates highest theoretical capacity up to 12 395 mA h g−1 when forming Li5B. Furthermore, it also exhibits promising features such as light weight, considerable reserves, low cost, and nontoxicity. However, boron‐based materials are not in the hotspot list because Li5B may only exist when B is in atomically isolated/dispersed form, while the aggregate material can barely be activated to store/release Li. At this time, an ingenious design is demonstrated to activate the inert B to a high specific capacity anode material by dispersing it in a Fe matrix. The above material can be obtained after an electrochemical activation of the precursors Fe2B/Fe and B2O3/Fe. The latter harvests the admirable capacity, ultrahigh tap density of 2.12 g cm−3, excellent cycling stability of 3180 mA h cm−3 at 0.1 A g−1 (1500 mA h g−1) after 250 cycles, and superlative rate capability of 2650 mA h cm−3 at 0.5 A g−1, 2544 mA h cm−3 at 1.0 A g−1, and 1696 mA h cm−3 at 2.0 A g−1. Highly conductive matrix promoted reversible Li storage of boron‐based materials might open a new gate for advanced anode materials.
Ultrasound Promoted Step‐Growth Polymerization and Polymer Crosslinking Via Copper Catalyzed Azide–Alkyne “Click” Reaction
Authors: Mohapatra Hemakesh , Ayarza Jorge , Sanders Emily C. , Scheuermann Angelique M. , Griffin Philip J. , Esser‐Kahn Aaron P. 
Published: July 2018

AbstractMechano‐activated chemistry is a powerful tool for remodeling of synthetic polymeric materials, however, few reactions are currently available. Here we show that using piezochemical reduction of a CuII‐based pre‐catalyst, a step‐growth polymerization occurs via the copper catalyzed azide–alkyne cycloaddition (CuAAC) reaction to form a linear polytriazole. Furthermore, we show that a linear polymer can be crosslinked mechanochemically using the same chemistry to form a solid organogel. We envision that this chemistry can be used to harness mechanical energy for constructive purposes in polymeric materials.
Regiodivergent Copper Catalyzed Borocyanation of 1,3‐Dienes
Authors: Jia Tao , He Qiong , Ruscoe Rebecca E. , Pulis Alexander P. , Procter David J. 
Published: July 2018

AbstractCopper catalyzed multi‐functionalization of unsaturated carbon‐carbon bonds is a powerful tool for the generation of complex molecules. We report a regiodivergent process that allows a switch between 1,4‐borocupration and 4,1‐borocupration of 1,3‐dienes upon a simple change in ligand. The subsequently generated allyl coppers are trapped in an electrophilic cyanation to selectively generate densely functionalized and synthetically versatile 1,2‐ or 4,3‐borocyanation products.
Metal‐Free Direct C−H Cyanation of Alkenes
Authors: Wang Xi , Studer Armido 
Published: July 2018

AbstractA metal‐free and direct alkene C−H cyanation is described. Directing groups are not required and the mechanism involves electrophilic activation of the alkene by a cyano iodine(III) species generated in situ from a [bis(trifluoroacetoxy)iodo]arene and trimethylsilyl cyanide as the cyanide source. This C−H functionalization can be conducted on gram scale, and for noncyclic 1,1‐ and 1,2‐disubstuted alkenes high stereoselectivity is achieved, thus rendering the method highly valuable.
A Fully Automated Continuous‐Flow Platform for Fluorescence Quenching Studies and Stern–Volmer Analysis
Authors: Kuijpers Koen P. L. , Bottecchia Cecilia , Cambié Dario , Drummen Koen , König Niels J. , Noël Timothy 
Published: July 2018

AbstractHerein, we report the first fully automated continuous‐flow platform for fluorescence quenching studies and Stern–Volmer analysis. All the components of the platform were automated and controlled by a self‐written Python script. A user‐friendly software allows even inexperienced operators to perform automated screening of novel quenchers or Stern–Volmer analysis, thus accelerating and facilitating both reaction discovery and mechanistic studies. The operational simplicity of our system affords a time and labor reduction over batch methods while increasing the accuracy and reproducibility of the data produced. Finally, the applicability of our platform is elucidated through relevant case studies.
Surprising Antibacterial Activity and Selectivity of Hydrophilic Polyphosphoniums Featuring Sugar and Hydroxy Substituents
Authors: Cuthbert Tyler J. , Hisey Benjamin , Harrison Tristan D. , Trant John F. , Gillies Elizabeth R. , Ragogna Paul J. 
Published: July 2018

AbstractThere is currently an urgent need for the development of new antibacterial agents to combat the spread of antibiotic‐resistant bacteria. We explored the synthesis and antibacterial activities of novel, sugar‐functionalized phosphonium polymers. While these compounds exhibited antibacterial activity, we unexpectedly found that the control polymer poly(tris(hydroxypropyl)vinylbenzylphosphonium chloride) showed very high activity against both Gram‐negative Escherichia coli and Gram‐positive Staphylococcus aureus and very low haemolytic activity against red blood cells. These results challenge the conventional wisdom in the field that lipophilic alkyl substituents are required for high antibacterial activity and opens prospects for new classes of antibacterial polymers.
Randomized clinical trial of stapler hepatectomy versus LigaSure™ transection in elective hepatic resection
Authors: Fritzmann J , Kirchberg J , Sturm D , Ulrich A B , Knebel P , Mehrabi A , Büchler M W , Weitz J , Reissfelder C , Rahbari N N 
Published: July 2018

Abstract

Background
Previous studies have demonstrated stapler hepatectomy and use of various energy devices to be safe alternatives to the clamp-crushing technique in elective hepatic resection. In this randomized trial, the effectiveness and safety of stapler hepatectomy were compared with those of parenchymal transection with the LigaSure™ vessel sealing system.

Method
Patients scheduled for elective liver resection at two tertiary-care centres were randomized during surgery to stapler hepatectomy or transection with the LigaSure™ device. Total intraoperative blood loss was the primary efficacy endpoint. Transection time, duration of operation, perioperative complications and length of hospital stay were recorded as secondary endpoints.

Results
A total of 138 patients were analysed, 69 in the LigaSure™ and 69 in the stapler hepatectomy group. Baseline characteristics were well balanced between the groups. Mean intraoperative blood loss was significantly higher in the LigaSure™ group than the stapler hepatectomy group: 1101 (95 per cent c.i. 915 to 1287) versus 961 (752 to 1170) ml (P = 0·028). The parenchymal transection time was significantly shorter in the stapler group (P = 0·005), as was the total duration of operation (P = 0·027). Surgical morbidity did not differ between the groups, nor did the grade of complications.

Conclusion
Stapler hepatectomy was associated with reduced blood loss and a shorter duration of operation than the LigaSure™ device for parenchymal transection in elective partial hepatectomy. Registration number: NCT01858987 (http://www.clinicaltrials.gov).
How do integrated quality and environmental management practices affect firm performance? Mediating roles of quality performance and environmental proactivity
Authors: Arda Ozlem Ayaz , Bayraktar Erkan , Tatoglu Ekrem 
Published: July 2018

AbstractBased on a sample of 208 Turkish firms, this paper investigates the integration of two management systems, quality management and environmental management, and explores the effect of this integration on firm performance. First, a conceptual framework was developed, relying on the premises of the resource‐based view. Second, mediating roles of quality performance and environmental proactivity were examined on the association between integrated quality and environmental management systems and firm performance. Among the underlying trends, both quality performance and environmental proactivity were found to fully mediate the relationship between integrated quality and environmental management and firm performance.
Examining the drivers and outcomes of corporate commitment to climate change action in European high emitting industry
Authors: Littlewood David , Decelis Rachel , Hillenbrand Carola , Holt Diane 
Published: July 2018

AbstractClimate change is a major strategic issue for firms that also has global environmental, social and economic implications. This paper draws upon quantitative survey research to examine the drivers and outcomes of corporate commitment to climate change action in European high emitting industry. More specifically, this research examines the significance of business drivers, sustainability drivers, and stakeholder pressure, in motivating corporate commitment to climate change action in such industry. It furthermore assesses relationships between commitment and actual corporate greenhouse gas (GHG) performance. It is found that in European high emitting industry, business drivers and stakeholder pressure, but not sustainability drivers, enhance corporate commitment to climate change action, and that higher commitment leads to improved GHG performance. This paper contributes to hitherto limited empirical work on the drivers and outcomes of corporate commitment to climate change action, particularly in European industry contexts. It also contributes to advancing methodology in the field.
RadioEarth: An educational software tool based on Google Earth for radioelectric coverage analysis
Authors: Juan‐Llacer Leandro , Rodriguez José‐Víctor , Molina‐Garcia‐Pardo José‐María , Pascual‐García Juan , Martínez‐Inglés Mayte 
Published: July 2018

AbstractThe expansion of wireless communication systems (GSM, UMTS, LTE, Wi‐Fi, Digital Television, etc.) has meant the inclusion of subjects in technical career studies in which the theoretical and practical aspects are studied and analyzed for planning these systems from a radioelectric point of view. However, the study of these systems is carried out, mainly, through software tools based on Geographic Information Systems (GIS) which implies the need to have prior knowledge of them by the students. In this sense, the majority of students are familiar with Google Earth because it has been used previously by them. This paper presents RadioEarth, a tool developed in JAVA, which interacts with Google Earth and allows simulations and analysis of radio coverage of wireless systems from an educational perspective.
Soploon: A virtual assistant to help teachers to detect object‐oriented errors in students’ source codes
Authors: Vallejos Sebastián , Berdun Luis S. , Armentano Marcelo G. , Soria Álvaro , Teyseyre Alfredo R. 
Published: July 2018

AbstractWhen checking students’ source codes, teachers tend to overlook some errors. This work introduces Soploon, a tool that automatically detects novice programmer errors. By using this tool, teachers can reduce the number of overlooked errors. Thus, students receive a more complete and exhaustive feedback about their errors and misconceptions.
Eu3+‐Activated Gd8V2O17: Energy Transfer, Luminescence, and Temperature‐Dependence Characteristics
Authors: Deng Bin , Liu Shihua , Zhou Chong‐song , Liu Hui , Chen Jun , Yu Ruijin 
Published: July 2018

AbstractA new phosphor of the type Gd8(1−x)Eu8 xV2O17 (x=0–1.0) was synthesized through the solid‐state reaction ceramics method. A pure phase formation was verified by using X‐ray powder diffraction measurements. The luminescence of Gd8V2O17:Eu3+ was investigated through optical and laser excitation spectroscopy. The luminescence curves were investigated in the temperature region 10 to 300 K. Gd8V2O17 shows a self‐activated luminescence under excitation with UV‐ and near‐UV light. The spectra, the decay lifetimes, and the thermal stability of Gd8(1−x)Eu8 xV2O17 (x=0.005–1.0) strongly depend on both the Eu3+ concentration and the temperature. The tunable luminescence is realized by controlling the Eu3+‐doping level to adjust the host energy‐transfer efficiency from the VO43− groups to the Eu3+ activators. At low Eu3+ concentrations (<30 mol %), the intensity and lifetime show an unusual change with an increase of the temperature from 10–300 K, that is, the luminescence experiences a straightforward enhancement. The energy transfer from the VO43− group to the Eu3+ ions could be accelerated with an increase of the temperature resulting in an unusual enhancement of the Eu3+ luminescence and lifetime. However, the emission of the Eu3+ ions decreased for highly Eu‐doped samples (>30 mol %) with an increase of the temperature. The luminescence mechanism was discussed on the basis of the charge‐transfer band of the Eu3+ ions, the doping concentration, and the proposed microstructures in the lattices.
Graphenide Solutions: A Chemical Platform for Nanoparticle–Nanocarbon Composites
Authors: Hof Ferdinand , Pénicaud Alain 
Published: July 2018

AbstractGraphenide solutions, comprising charged graphene layers in aprotic organic solutions, are exploited as a chemical platform to graft transition‐metal oxide nanoparticles, namely nickel, manganese, copper, and cobalt oxide, onto the carbon framework. The reduction process is driven and controlled by the graphenide solution yielding nanoparticles with comparable sizes for all studied metal salts, well below 10 nm. The synthesis is generic and is not limited by the type of metal salt, because the reduced graphene layers serve simultaneously as both substrates and reducing agents. This reaction is reliable, reproducible, and versatile, generating materials for catalytic purposes without requiring any kind of stabilization or capping agents.
Boosting Lithium Storage Properties of MOF Derivatives through a Wet‐Spinning Assembled Fiber Strategy
Authors: Zhang Lin , Liu Wenxian , Shi Wenhui , Xu Xilian , Mao Jing , Li Peng , Ye Chenzeng , Yin Ruilian , Ye Shaofeng , Liu Xiaoyue , Cao Xiehong , Gao Chao 
Published: July 2018

AbstractGraphene composite fibers are of great importance in constructing electrode materials with high flexibility and conductivity for energy storage and electronic devices. Integration of multifunctional metal–organic frameworks (MOFs) into graphene fiber scaffolds enables novel functions and enhanced physical/chemical properties. The close‐packed and aligned graphene sheets along with the porous MOF‐derived structures can achieve excellent lithium storage performance through synergetic effects. In this work, a facile and general strategy is demonstrated for the preparation of MOF/graphene oxide (GO) fibers, which serve as precursors for the subsequent preparation of porous metal oxide/reduced graphene oxide (rGO) composite fibers. The obtained composites, for example, porous Fe2O3/rGO and Co3O4/rGO fibers, possess unique features of MOF‐derived porous structures and excellent electrical conductivity. When tested as anode materials for lithium‐ion batteries in coin cells, the MOF/GO fiber‐derived porous metal oxide/rGO composite fibers exhibited high specific capacity, excellent rate capability and cycling performance. Moreover, a flexible fiber battery was fabricated based on the Fe2O3/rGO composite fiber, which demonstrates its potential application for flexible electronic devices.