bluuebunny/crossref_metadata_2025 huggingface dataset:
Ion beams in the plasma sheet boundary layer
Authors: Birn J. , Hesse M. , Runov A. , Zhou X.‐Z.
Published: August 2015

We explore characteristics of energetic particles in the plasma sheet boundary layer associated with dipolarization events, based on simulations and observations. The simulations use the electromagnetic fields of an MHD simulation of magnetotail reconnection and flow bursts as basis for test particle tracing. They are complemented by self‐consistent fully electrodynamic particle‐in‐cell (PIC) simulations. The test particle simulations confirm that crescent‐shaped earthward flowing ion velocity distributions with strong perpendicular anisotropy can be generated as a consequence of near‐tail reconnection, associated with earthward flows and propagating magnetic field dipolarization fronts. Both PIC and test particle simulations show that the ion distribution in the outflow region close to the reconnection site also consist of a beam superposed on an undisturbed population, which, however, does not show strong perpendicular anisotropy. This suggests that the crescent shape is created by quasi‐adiabatic deformation from ion motion along the magnetic field toward higher field strength. The simulation results compare favorably with “Time History of Events and Macroscale Interactions during Substorms” observations.
A case study of typhoon‐induced gravity waves and the orographic impacts related to Typhoon Mindulle (2004) over Taiwan
Authors: Wu J. F. , Xue X. H. , Hoffmann L. , Dou X. K. , Li H. M. , Chen T. D.
Published: August 2015

Atmospheric gravity waves (GWs) significantly influence global circulation. Deep convection, particularly that associated with typhoons, is believed to be an important source of gravity waves. Stratospheric gravity waves induced by Typhoon Mindulle (2004) were detected by the Atmospheric Infrared Sounder (AIRS). Semicircular GWs with horizontal wavelengths of 100–400 km were found over Taiwan through an inspection of AIRS radiances at 4.3 μm. Characteristics of the stratospheric gravity waves generated by Typhoon Mindulle were investigated using the Weather Research and Forecasting (WRF) model. The initial and boundary data were determined by the high‐resolution European Center for Medium‐Range Weather Forecasts reanalysis data. The WRF simulation reproduces the main features of Typhoon Mindulle and the significant GWs. The simulated GWs with horizontal wavelengths of 100–400 km match the AIRS observations: they propagate upward and eastward, and the westward components are mostly filtered in the stratosphere. By comparing the measured waves with a WRF simulation in the absent of orography (WRF‐FLAT), we find that the orographic gravity waves (OGWs) generated by the flow of Typhoon Mindulle over the Central Mountain Range (CMR) in Taiwan account for approximately 50% of the total wave momentum flux in the troposphere. The dominant orientation of the OGW wave fronts is parallel to the CMR rideline. When entering into the stratosphere, OGW propagation is determined by the position of the typhoon center relative to the CMR.
Comparison of the effect of high‐latitude and equatorial ionospheric scintillation on GPS signals during the maximum of solar cycle 24
Authors: Jiao Yu , Morton Yu T.
Published: August 2015

Radio signal scintillation caused by electron density irregularities in the ionosphere affects the accuracy and integrity of Global Navigation Satellite Systems, especially in the equatorial and high‐latitude regions during solar maxima. Scintillation in these two regions, nevertheless, is usually influenced by different factors and thus has different characteristics that cause different effects on GNSS signals. This paper compares the characteristics of high‐latitude and equatorial scintillation using multifrequency GPS scintillation data collected at Gakona, Alaska, Jicamarca, Peru, and Ascension Island during the 24th solar maximum. Several statistical distributions are established based on the data to characterize the intensity, duration, and occurrence frequency of scintillation. Results show that scintillation in the equatorial region is generally more severe and longer lasting, while high‐latitude scintillation is, in general, more moderate and usually dominated by phase fluctuations. Results also reveal the different impacts of solar activity, geomagnetic activity, and seasons on scintillation in different geographic locations.
Adaptive failure compensation of hysteretic actuators for a class of nonlinear systems via output feedback
Authors: Liu Ye , Yang Zaihua , Lin Yan
Published: August 2015

In this paper, an adaptive output feedback control scheme is proposed for a class of nonlinear systems with possible actuator failures. The system not only involves unknown parameters but also takes nonlinear terms linear in the unmeasured states into account and is preceded by hysteretic actuators whose nonlinearities are characterized by the saturated Prandtl–Ishlinskii model. By developing a high‐gain observer with one dynamic gain, the closed‐loop stability and arbitrarily small tracking error can be guaranteed. Furthermore, by estimating the upper bound of the unknown time‐varying (piecewise constant) parameters caused by the actuator failures, together with an initialization technique, it is proved that the
tracking performance is achievable, which is fundamentally different from the commonly accepted concept that with actuator failures, it is impossible to improve the
tracking performance by using initialization technique. Copyright © 2015 John Wiley & Sons, Ltd.
Living Cells Directly Growing on a DNA/Mn3(PO4)2‐Immobilized and Vertically Aligned CNT Array as a Free‐Standing Hybrid Film for Highly Sensitive In Situ Detection of Released Superoxide Anions
Authors: Hu Fang Xin , Kang Yue Jun , Du Feng , Zhu Lin , Xue Yu Hua , Chen Tao , Dai Li Ming , Li Chang Ming
Published: August 2015

It is important to detect reactive oxygen species (ROS) in situ for investigation of various critical biological processes, and this is however very challenging because of the limited sensitivity or/and selectivity of existing methods that are mainly based on sensing ROS released by cells with short lifetimes and low concentrations in a culture medium. Here, a new approach is reported to directly grow living cells on DNA/Mn3(PO4)2‐immobilized and vertically aligned carbon nanotube (VACNT) array nanostructure as a smart free‐standing hybrid film, of which the DNA/Mn3(PO4)2 and VACNT provide high electroactivity and excellent electron transport, respectively, while the directly grown cell on the nanostructure offers short diffusion distance to reaction sites, thus constructing a highly sensitive in situ method for detection of cancer‐cell‐released ROS under drug stimulations. Compared to the measured ROS released by cells in a culture medium, the detection sensitivity with this constructed hybrid film increases by more than six times, which implies that ROS molecules (superoxide anions) secreted from living cells are immediately captured by this smart structure without diffusion process or with extremely short diffusion distance. This design considerably reduces the time from release to detection of the target molecules, minimizing the potential molecular decay due to the short lifetime or high reactivity.
Structural Design Elements in Biological Materials: Application to Bioinspiration
Authors: Naleway Steven E. , Porter Michael M. , McKittrick Joanna , Meyers Marc A.
Published: August 2015

Eight structural elements in biological materials are identified as the most common amongst a variety of animal taxa. These are proposed as a new paradigm in the field of biological materials science as they can serve as a toolbox for rationalizing the complex mechanical behavior of structural biological materials and for systematizing the development of bioinspired designs for structural applications. They are employed to improve the mechanical properties, namely strength, wear resistance, stiffness, flexibility, fracture toughness, and energy absorption of different biological materials for a variety of functions (e.g., body support, joint movement, impact protection, weight reduction). The structural elements identified are: fibrous, helical, gradient, layered, tubular, cellular, suture, and overlapping. For each of the structural design elements, critical design parameters are presented along with constitutive equations with a focus on mechanical properties. Additionally, example organisms from varying biological classes are presented for each case to display the wide variety of environments where each of these elements is present. Examples of current bioinspired materials are also introduced for each element.
Synthesis and Electrochemical Evaluation of Conductive Polyacrylamide Nanocomposite Hydrogels
Authors: DIDEHBAN KHADIJEH , ABDI MAHTAB , SHARIF FARHAD
Published: August 2015

Conductive hydrogel nanocomposites containing graphite, graphene oxide (GO), and graphene particles were synthesized by free radical polymerization in aqueous solution. The effect of cross‐linker, initiator, graphite, GO, and graphene concentrations on water absorbency and electrical conductivity of hydrogels was investigated. The synthesized composites were then characterized by X‐ray diffraction, Fourier transform infrared spectroscopy, Raman spectroscopy, scanning electron microscopy, and thermogravimetric analysis. The graphene/polyacrylamide hydrogels showed highest conductivity of about 0.2 S cm−1, and specific capacitance of polyacrylamide/graphene hydrogel in H2SO4 solution was found to be 616 F g−1.
Fe‐Based Tunnel‐Type Na0.61[Mn0.27Fe0.34Ti0.39]O2 Designed by a New Strategy as a Cathode Material for Sodium‐Ion Batteries
Authors: Xu Shuyin , Wang Yuesheng , Ben Liubin , Lyu Yingchun , Song Ningning , Yang Zhenzhong , Li Yunming , Mu Linqin , Yang Hai‐Tao , Gu Lin , Hu Yong‐Sheng , Li Hong , Cheng Zhao‐Hua , Chen Liquan , Huang Xuejie
Published: August 2015

Sodium‐ion batteries are promising for grid‐scale storage applications due to the natural abundance and low cost of sodium. However, few electrodes that can meet the requirements for practical applications are available today due to the limited routes to exploring new materials. Here, a new strategy is proposed through partially/fully substituting the redox couple of existing negative electrodes in their reduced forms to design the corresponding new positive electrode materials. The power of this strategy is demonstrated through the successful design of new tunnel‐type positive electrode materials of Na0.61[Mn0.61‐xFexTi0.39]O2, composed of non‐toxic and abundant elements: Na, Mn, Fe, Ti. In particular, the designed air‐stable Na0.61[Mn0.27Fe0.34Ti0.39]O2 shows a usable capacity of ≈90 mAh g−1, registering the highest value among the tunnel‐type oxides, and a high storage voltage of 3.56 V, corresponding to the Fe3+/Fe4+ redox couple realized for the first time in non‐layered oxides, which was confirmed by X‐ray absorption spectroscopy and Mössbauer spectroscopy. This new strategy would open an exciting route to explore electrode materials for rechargeable batteries.
Real‐time fatigue reduction in emergency care clinicians: The SleepTrackTXT randomized trial
Authors: Patterson P. Daniel , Buysse Daniel J. , Weaver Matthew D. , Doman Jack M. , Moore Charity G. , Suffoletto Brian P. , McManigle Kyle L. , Callaway Clifton W. , Yealy Donald M.
Published: August 2015

Background

We assessed performance characteristics and impact of a mobile phone text‐message intervention for reducing intra‐shift fatigue among emergency clinician shift workers.

Methods

We used a randomized controlled trial of 100 participants. All participants received text‐message assessments at the start, every 4 hr during, and at end of scheduled shifts over a 90‐day period. Text‐message queries measured self‐rated sleepiness, fatigue, and difficulty with concentration. Additional text‐messages were sent to intervention participants to promote alertness. A performance measure of interest was compliance with answering text‐messages.

Results

Ninety‐nine participants documented 2,621 shifts and responded to 36,073 of 40,947 text‐messages (88% compliance rate). Intervention participants reported lower mean fatigue and sleepiness at 4 hr, 8 hr, and at the end of 12 hr shifts compared to controls (P < 0.05). Intervention participants reported better sleep quality at 90‐days compared to baseline (P = 0.01).

Conclusions

We showed feasibility and short‐term efficacy of a text‐message based assessment and intervention tool. Am. J. Ind. Med. 58:1098–1113, 2015. © 2015 Wiley Periodicals, Inc.
Patterns of pneumoconiosis mortality in Kentucky: Analysis of death certificate data
Authors: Beggs Jake A. , Slavova Svetla , Bunn Terry L.
Published: August 2015

Background

Mortality rates associated with total pneumoconiosis, including coal worker's pneumoconiosis (CWP), have remained elevated.

Methods

2003–2013 pneumoconiosis mortality data obtained from National Center for Health Statistics and 2011–2013 Kentucky death certificates were analyzed.

Results

Total pneumoconiosis mortality rates showed significant linear decreases in West Virginia, Pennsylvania, Kentucky, and the U.S. from 2003 to 2013; Pennsylvania and Kentucky had comparable rates in 2003 but while Pennsylvania rates significantly decreased ∼3.0 deaths/million annually, Kentucky rates decreased only 0.5/million annually. Kentucky and Pennsylvania CWP fatality rates were also comparable in 2003 but while Pennsylvania rates decreased 82% over the study period, Kentucky rates decreased only 26%. Kentucky pneumoconiosis deaths primarily occurred in white Appalachian males in‐hospital. Diseases leading to pneumoconiosis death were largely respiratory and cardiovascular, with autopsies rarely performed.

Conclusions

Coal worker environmental exposure protection should be enhanced and pneumoconiosis surveillance improvements, including enhanced management of comorbid conditions like COPD, should be considered. Am. J. Ind. Med. 58:1075–1082, 2015. © 2015 Wiley Periodicals, Inc.
Synthesis of Multifunctional Alkenes from Substituted Acrylates and Aldehydes via Phosphine‐Catalyzed Wittig Reaction
Authors: Tsai Yi‐Ling , Lin Wenwei
Published: August 2015

An efficient synthesis of multifunctional alkenes starting from substituted acrylates and aldehydes has been developed via phosphine‐catalyzed Wittig reactions. The reactions proceed smoothly even under mild conditions (30–60 °C) via a phosphine/phosphine oxide catalytic cycle using phenyl silane as the reducing agent. According to this simple protocol, the desired products are obtained in moderate to excellent yields as single stereoisomers.
Revisiting the Phenice technique sex classification results reported by MacLaughlin and Bruce (1990)
Authors: McFadden Clare , Oxenham Marc F.
Published: August 2015

Phenice (Am J Phys Anthropol 30 (1969):297–301) reported a success rate of 96% for his method of sex determination based on three morphological features of the pelvis. Numerous studies have tested and evaluated the method with affirmative results. The results of the study by MacLaughlin and Bruce (J Forensic Sci 35 (1990):1384–1392) were inconsistent with other studies, reporting far lower rates of accuracy and a greater degree of interobserver error. The authors believe that this may be the result of the inclusion of an “ambiguous” classification category. Revised modelling using forced classification of sex provides much higher classification rates with the implication that the poor results reported by MacLaughlin and Bruce were due to methodological error for the most part. Am J Phys Anthropol 159:182–183, 2016. © 2015 Wiley Periodicals, Inc.
Interpreting adult stature in industrial London
Authors: Hughes‐Morey Gail
Published: August 2015

Objectives

This study examines adult stature and its association with risk of mortality in two skeletal collections from industrializing London, taking sex and socioeconomic status into account as potential sources of heterogeneity in frailty.

Methods

Mean femur and tibia lengths and the distributions of short femora and tibiae were examined in adult skeletons from the cemeteries at Lower Saint Bride's (low status) and Chelsea Old Church (high status). Cox proportional hazards models were used to determine if stature was associated with risk of mortality and how that relationship varied with sex and socioeconomic status.

Results

High‐status females had significantly longer femora, but not tibiae, on average, than low‐status females. There were no status‐based differences in mean element lengths among males. There were sex and status based differences in the distribution of short femora and tibiae, and there was a significant negative association between tibia length and risk of mortality in high‐status females.

Discussion

The results may be explained by differences in subadult mortality, potentially due to variation in infant feeding practices. Low‐status infants were more likely to live in pathogenic environments and less likely to be breastfed, leading to both stature and immunological deficits, thus minimizing the association between adult stature and mortality, as the shortest individuals did not survive into adulthood. The ways in which migration and repeated epidemics of plague may have shaped stature variation during industrialization are also discussed, highlighting the importance of context in understanding the association between stature and mortality. Am J Phys Anthropol 159:126–134, 2016. © 2015 Wiley Periodicals, Inc.
Silicification‐Induced Cell Aggregation for the Sustainable Production of H2 under Aerobic Conditions
Authors: Xiong Wei , Zhao Xiaohong , Zhu Genxing , Shao Changyu , Li Yaling , Ma Weimin , Xu Xurong , Tang Ruikang
Published: August 2015

Photobiological hydrogen production is of great importance because of its promise for generating clean renewable energy. In nature, green algae cannot produce hydrogen as a result of the extreme sensitivity of hydrogenase to oxygen. However, we find that silicification‐induced green algae aggregates can achieve sustainable photobiological hydrogen production even under natural aerobic conditions. The core–shell structure of the green algae aggregates creates a balance between photosynthetic electron generation and hydrogenase activity, thus allowing the production of hydrogen. This finding provides a viable pathway for the solar‐driven splitting of water into hydrogen and oxygen to develop green energy alternatives by using rationally designed cell–material complexes.
Zinc‐Catalyzed Alkene Cyclopropanation through Zinc Vinyl Carbenoids Generated from Cyclopropenes
Authors: González María J. , González Javier , López Luís A. , Vicente Rubén
Published: August 2015

The zinc‐catalyzed reaction of cyclopropenes with alkenes leading to vinylcyclopropane derivatives is reported. A broad range of alkenes (including highly substituted or functionalized alkenes) is compatible with this protocol. On the basis of trapping experiments and computational studies, this cyclopropanation reaction is proposed to proceed through initial formation of an electrophilic zinc vinyl carbenoid intermediate, which may be involved in a concerted cyclopropanation reaction. The reported protocol represents an unprecedented and simple strategy for the catalytic generation of zinc vinyl carbenoids, which are promising intermediates in organic synthesis.
HAZOP analysis‐based dynamic simulation and its application in chemical processes
Authors: Tian Wende , Du Tingzhao , Mu Shanjun
Published: August 2015

Hazard and operability analysis (HAZOP) is widely applied in petroleum industry as a scientific and effective safety analysis method, but it is traditionally qualitative in essence and hereby has such shortages as vague conclusions, susceptible to human factor, lack of comprehensive consideration, and so on. This paper proposed a dynamic simulation‐based quantitative HAZOP method that utilizes dynamic simulation to reason deviations to reduce uncertainty in manual analysis. It transforms deviations into quantitative dynamic tasks and uses these tasks to activate dynamic simulation for quantitative deviation reasoning work. The possible consequence and propagation time caused by deviation is probed by analyzing simulation results. In this process, some deviations that appeared seldom or did not at all before can also be simulated and analyzed with the aid of dynamic mechanism model. Case studies in extractive distillation and ammonia synthesis loop showed that this method can present propagation effect of key process parameters on safety state and is useful for iterative and automatic assessment work. It is also found that detailed operation and device data are necessary for initial complex process modeling. In addition, we should improve simulation platform to meet practical requirements when applying this method. © 2015 Curtin University of Technology and John Wiley & Sons, Ltd.
Children with Autism Show Altered Autonomic Adaptation to Novel and Familiar Social Partners
Authors: Neuhaus Emily , Bernier Raphael A. , Beauchaine Theodore P.
Published: August 2015

Social deficits are fundamental to autism spectrum disorder (ASD), and a growing body of research implicates altered functioning of the autonomic nervous system (ANS), including both sympathetic and parasympathetic branches. However, few studies have explored both branches concurrently in ASD, particularly within the context of social interaction. The current study investigates patterns of change in indices of sympathetic (pre‐ejection period; PEP) and parasympathetic (respiratory sinus arrhythmia; RSA) cardiac influence as boys (ages 8–11 years) with (N = 18) and without (N = 18) ASD engage in dyadic social interaction with novel and familiar social partners. Groups showed similar patterns of autonomic change during interaction with the novel partner, but differed in heart rate, PEP, and RSA reactivity while interacting with a familiar partner. Boys without ASD evinced decreasing sympathetic and increasing parasympathetic influence, whereas boys with ASD increased in sympathetic influence. Boys without ASD also demonstrated more consistent ANS responses across partners than those with ASD, with parasympathetic responding differentiating familiar and novel interaction partners. Finally, PEP slopes with a familiar partner correlated with boys' social skills. Implications include the importance of considering autonomic state during clinical assessment and treatment, and the potential value of regulation strategies as a complement to intervention programs aiming to support social cognition and behavior. Autism Res 2016, 9: 579–591. © 2015 International Society for Autism Research, Wiley Periodicals, Inc.
Valproic Acid Induces the Hyperacetylation of P53, Expression of P53 Target Genes, and Markers of the Intrinsic Apoptotic Pathway in Midorganogenesis Murine Limbs
Authors: Paradis France‐Hélène , Hales Barbara F.
Published: August 2015

In utero exposure to valproic acid (VPA), an anticonvulsant and histone deacetylase inhibitor (HDACi), increases the risk of congenital malformations. Although the mechanisms leading to the teratogenicity of VPA remain unsolved, several HDAC inhibitors increase cell death in cancer cell lines and embryonic tissues. Moreover, P53, the master regulator of apoptosis, is an established HDAC target. The purpose of this study was to investigate the effects of VPA on P53 signaling and markers of apoptosis during midorganogenesis in vitro limb development. Timed‐pregnant CD1 mice (gestation day 12) were euthanized; embryonic forelimbs were excised and cultured in vitro for 3, 6, 12, or 24 hr in the presence or absence of VPA or valpromide (VPD), a non‐HDACi analog of VPA. Quantitative RT‐PCR and Western blots were used to assess the expression of candidate genes and proteins involved in P53 signaling and apoptosis. P53 hyperacetylation and a decrease (Survivin/Birc5 and Bcl2) or an increase (p21/Cdkn1a) in the expression of p53 target genes was observed only in VPA‐exposed limbs. VPA exposure also triggered an increase in markers of apoptosis and DNA damage; the concentrations of cleaved caspase 9 and caspase 3, cleaved‐poly (ADP‐ribose) polymerase, and γ‐H2AX were increased in VPA‐exposed limbs. VPD treatment caused a small but significant increase in cleaved caspase 3. Thus, in vitro exposure to an HDACi such as VPA leads to P53 hyperacetylation, enhances the expression of P53 target genes, and triggers an increase in apoptosis that may contribute to teratogenicity
Can a few non‐coding mutations make a human brain?
Authors: Franchini Lucía F. , Pollard Katherine S.
Published: August 2015

The recent finding that the human version of a neurodevelopmental enhancer of the Wnt receptor Frizzled 8 (FZD8) gene alters neural progenitor cell cycle timing and brain size is a step forward to understanding human brain evolution. The human brain is distinctive in terms of its cognitive abilities as well as its susceptibility to neurological disease. Identifying which of the millions of genomic changes that occurred during human evolution led to these and other uniquely human traits is extremely challenging. Recent studies have demonstrated that many of the fastest evolving regions of the human genome function as gene regulatory enhancers during embryonic development and that the human‐specific mutations in them might alter expression patterns. However, elucidating molecular and cellular effects of sequence or expression pattern changes is a major obstacle to discovering the genetic bases of the evolution of our species. There is much work to do before human‐specific genetic and genomic changes are linked to complex human traits.

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Investigation on the interaction of cefpirome sulfate with lysozyme by fluorescence quenching spectroscopy and synchronous fluorescence spectroscopy
Authors: Han Rong , Liu Baosheng , Li Gaixia , Zhang Qiuju
Published: August 2015

The reaction mechanism of cefpirome sulfate with lysozyme at different temperatures (298, 310 and 318 K) was investigated using fluorescence quenching and synchronous fluorescence spectroscopy under simulated physiological conditions. The results clearly demonstrated that cefpirome sulfate caused strong quenching of the fluorescence of lysozyme by a static quenching mechanism. The binding constants obtained using the above methods were of the same order of magnitude and very similar. Static electric forces played a key role in the interaction between cefpirome sulfate and lysozyme, and the number of binding sites in the interaction was close to 1. The values of Hill's coefficients were > 1, indicating that drugs or proteins showed a very weakly positive cooperativity in the system. In addition, the conclusions obtained from the two methods using the same equation were consistent. The results indicated that synchronous fluorescence spectrometry could be used to study the binding mechanism between drug and protein, and was a useful supplement to the fluorescence quenching method. In addition, the effect of cefpirome sulfate on the secondary structure of lysozyme was analyzed using circular dichroism spectroscopy. Copyright © 2015 John Wiley & Sons, Ltd.
Enzymatic Assays Coupled with Mass Spectrometry with or without Embedded Liquid Chromatography
Authors: Burkhardt Therese , Kaufmann Christine M. , Letzel Thomas , Grassmann Johanna
Published: August 2015

This article reviews monitoring strategies for enzymatic assays coupled with mass spectrometric detection. This coupling has already been shown to be helpful in providing versatile and detailed knowledge about enzyme kinetics. Various available publications address two general approaches. 1) The continuous‐flow setup allows real‐time determination of substrate degradation. Simultaneously, resulting product or potential intermediates can be detected. 2) The online coupled continuous‐flow mixing assay allows the direct coupling of an enzymatic assay to chromatographic separation of complex mixtures. The latest efforts in improving the methodology have been made with regard to miniaturization. This is especially advantageous with regard to reducing costly consumption of chemicals. Finally, these developments are applicable for diverse bioanalytical purposes in the realms of pharmaceutical, biotechnological, food, and environmental research.
Carbon Spheres Prepared by Hydrothermal Synthesis—A Support for Bimetallic Iron Cobalt Fischer–Tropsch Catalysts
Authors: Dlamini Mbongiseni W. , Kumi David O. , Phaahlamohlaka Tumelo N. , Lyadov Anton S. , Billing David G. , Jewell Linda L. , Coville Neil J.
Published: August 2015

Carbon spheres (CSs) synthesised by the hydrothermal approach were explored as a model support material for a bimetallic Fe–Co Fischer–Tropsch (FT) catalyst. The CSs were characterised by N2 adsorption–desorption, thermogravimetric analysis, FTIR spectroscopy and powder XRD. If annealed at 900 °C for 4 h, the CSs exhibited an improved surface area, thermal stability and crystallinity. A series of Fe–Co bimetallic FT catalysts supported on the annealed CSs were prepared by co‐precipitation. A variety of Fe‐to‐Co ratios were used with the total metal loadings maintained at 10 %. Catalyst reducibility studies were performed by H2 temperature‐programmed reduction and in situ powder XRD. Catalysts with a Fe/Co ratio of 5:5 (w/w) showed Co–Fe alloy formation upon reduction at >450 °C. Interestingly, the presence of this alloy did not correlate with high C5+ selectivities during FT synthesis; rather the Co‐rich/Fe‐poor catalyst gave the best selectivity. The CSs allowed the metal–metal interactions in the bimetallic systems to be monitored because of the weak interaction of the metals with the support.
Co3O4–MnO2–CNT Hybrids Synthesized by HNO3 Vapor Oxidation of Catalytically Grown CNTs as OER Electrocatalysts
Authors: Xie Kunpeng , Masa Justus , Madej Edyta , Yang Fengkai , Weide Philipp , Dong Weiwen , Muhler Martin , Schuhmann Wolfgang , Xia Wei
Published: August 2015

An efficient two‐step gas‐phase method was developed for the synthesis of Co3O4–MnO2–CNT hybrids used as electrocatalysts in the oxygen evolution reaction (OER). Spinel Co–Mn oxide was used for the catalytic growth of multiwalled carbon nanotubes (CNTs) and the amount of metal species remaining in the CNTs was adjusted by varying the growth time. Gas‐phase treatment in HNO3 vapor at 200 °C was performed to 1) open the CNTs, 2) oxidize encapsulated Co nanoparticles to Co3O4 as well as MnO nanoparticles to MnO2, and 3) to create oxygen functional groups on carbon. The hybrid demonstrated excellent OER activity and stability up to 37.5 h under alkaline conditions, with longer exposure to HNO3 vapor up to 72 h beneficial for improved electrocatalytic properties. The excellent OER performance can be assigned to the high oxidation states of the oxide nanoparticles, the strong electrical coupling between these oxides and the CNTs as well as favorable surface properties rendering the hybrids a promising alternative to noble metal based OER catalysts.
Cascade Reaction through Different Microorganisms for Electrochemical Oxidation of Ethanol
Authors: Matsumoto Ryuhei , Fujita Shuji , Goto Yoshio
Published: August 2015

This paper demonstrates that an artificially constructed microbial community extracts 10.4 electrons of 12 electrons from an ethanol molecule, with 87 % coulombic efficiency of the complete oxidation under ambient temperature. Two separately cultured bacteria of Acetobacter aceti (A. aceti) and Escherichia coli (E. coli) are mixed in a micro‐electrolysis cell with an electron‐transfer mediator. The coulombic yield corresponds to the sum of ethanol oxidation with A. aceti and acetate oxidation with E. coli; a microbial cascade reaction occurs within this system. When Gluconobacter oxydans (G. oxydans) was employed instead of A. aceti, 8.4 electrons were extracted from one ethanol molecule. These microbial cascades show examples of highly efficient energy‐conversion systems. Our results suggest that combinations of microorganisms that do not coexist in nature would enable reactions that a single microorganism or an industrial catalyst has not ever established.
(−)‐Tarchonanthuslactone: Design of New Analogues, Evaluation of their Antiproliferative Activity on Cancer Cell Lines, and Preliminary Mechanistic Studies
Authors: Toneto Novaes Luiz Fernando , Martins Avila Carolina , Pelizzaro‐Rocha Karin Juliane , Vendramini‐Costa Débora Barbosa , Pereira Dias Marina , Barbosa Trivella Daniela Barreto , Ernesto de Carvalho João , Ferreira‐Halder Carmen Veríssima , Pilli Ronaldo Aloise
Published: August 2015

Natural products containing the α,β‐unsaturated δ‐lactone skeleton have been shown to possess a variety of biological activities. The natural product (−)‐tarchonanthuslactone (1) possessing this privileged scaffold is a popular synthetic target, but its biological activity remains underexplored. Herein, the total syntheses of dihydropyran‐2‐ones modeled on the structure of 1 were undertaken. These compounds were obtained in overall yields of 17–21 % based on the Keck asymmetric allylation reaction and were evaluated in vitro against eight different cultured human tumor cell lines. We further conducted initial investigation into the mechanism of action of selected analogues. Dihydropyran‐2‐one 8 [(S,E)‐(6‐oxo‐3,6‐dihydro‐2H‐pyran‐2‐yl)methyl 3‐(3,4‐dihydroxyphenyl)acrylate], a simplified analogue of (−)‐tarchonanthuslactone (1) bearing an additional electrophilic site and a catechol system, was the most cytotoxic and selective compound against six of the eight cancer cell lines analyzed, including the pancreatic cancer cell line. Preliminary studies on the mechanism of action of compound 8 on pancreatic cancer demonstrated that apoptotic cell death takes place mediated by an increase in the level of reactive oxygen species. It appears as though compound 8, possessing two Michael acceptors and a catechol system, may be a promising scaffold for the selective killing of cancer cells, and thus, it deserves further investigation to determine its potential for cancer therapy.
LASSBio‐1829 Hydrochloride: Development of a New Orally Active N‐Acylhydrazone IKK2 Inhibitor with Anti‐inflammatory Properties
Authors: Guedes Isabella A. , Freitas Rosana H. C. N. , Cordeiro Natália M. , Nascimento Thaís S. do , Valerio Tayna S. , Fernandes Patrícia D. , Dardenne Laurent E. , Fraga Carlos A. M.
Published: August 2015

Inhibitor of nuclear factor κB kinase 2 (IKK2) is suggested to be a potential target for the development of novel anti‐inflammatory and anticancer drugs. In this work, we applied structure‐based drug design to improve the potency of the inhibitor (E)‐N′‐(4‐nitrobenzylidene)‐2‐naphthohydrazide (LASSBio‐1524, 1 a: IC50=20 μm). The molecular model built for IKK2 together with the docking methodology employed were able to provide important and consistent information with respect to the structural and chemical inhibitor characteristics that may confer potency to IKK2 inhibitors, providing important guidelines for the development of a new N‐acylhydrazone (NAH) derivative. (E)‐N′‐(4‐(1H‐pyrrolo[2,3‐b]pyridin‐4‐yl)benzylidene)‐2‐naphthohydrazide hydrochloride (LASSBio‐1829 hydrochloride, 10) is a 7‐azaindole NAH able to inhibit IKK2 with an IC50 value of 3.8 μm. LASSBio‐1829 hydrochloride was found to be active in several pharmacological inflammation tests in vivo, showing its potential as an anti‐inflammatory prototype.
Triphilic Ionic‐Liquid Mixtures: Fluorinated and Non‐fluorinated Aprotic Ionic‐Liquid Mixtures
Authors: Hollóczki Oldamur , Macchiagodena Marina , Weber Henry , Thomas Martin , Brehm Martin , Stark Annegret , Russina Olga , Triolo Alessandro , Kirchner Barbara
Published: August 2015

We present here the possibility of forming triphilic mixtures from alkyl‐ and fluoroalkylimidazolium ionic liquids, thus, macroscopically homogeneous mixtures for which instead of the often observed two domains—polar and nonpolar—three stable microphases are present: polar, lipophilic, and fluorous ones. The fluorinated side chains of the cations indeed self‐associate and form domains that are segregated from those of the polar and alkyl domains. To enable miscibility, despite the generally preferred macroscopic separation between fluorous and alkyl moieties, the importance of strong hydrogen bonding is shown. As the long‐range structure in the alkyl and fluoroalkyl domains is dependent on the composition of the liquid, we propose that the heterogeneous, triphilic structure can be easily tuned by the molar ratio of the components. We believe that further development may allow the design of switchable, smart liquids that change their properties in a predictable way according to their composition or even their environment.
Theoretical Insights into the Tuning of Metal Binding Sites of Paddlewheels in rht‐Metal–Organic Frameworks
Authors: Pham Tony , Forrest Katherine A. , Gao Wen‐Yang , Ma Shengqian , Space Brian
Published: August 2015

Theoretical investigations of CO2 sorption are performed in four members of the highly tunable rht‐metal–organic framework (MOF) platform. rht‐MOFs contain two Cu2+ ions that comprise the metal paddlewheels and both are in chemically distinct environments. Indeed, one type of Cu2+ ion faces toward the center of the linker whereas the other type faces away from the center of the linker. Electronic structure calculations on the series of rht‐MOFs demonstrate that one of the Cu2+ ions has a consistently higher charge magnitude relative to the other. As a consequence, the Cu2+ ion with the higher partial positive charge acts as the favored sorbate binding site at initial loading as revealed by grand canonical Monte Carlo (GCMC) simulations that include many‐body polarization. It was found that the charge distribution about the copper paddlewheels is dependent on the type of functional groups present on the linker. This study demonstrates how the binding site about the metal paddlewheels in the rht‐MOF platform can be controlled by changing the functionality on the organic ligand.
Three‐Dimensionally Controllable Synthesis of Multichannel Silica Nanotubes and Their Application as Dual Drug Carriers
Authors: Wang Haiqing , Xiong Cuirong , Li Zheng , Kong Yan , Chen Jin , Wang Jun
Published: August 2015

Three‐dimensionally controllable multichannel silica nanotubes (MC‐SNTs) have been constructed. Quaternary ammonium type (CnH2n+1(CH3)3N+) surfactants were used as structure‐directing agents (SDAs) in basic ammonia. A low concentration of block copolymer HO(CH2CH2O)20[CH2CH(CH3)O]70(CH2CH2O)20H (P123) was employed as an additive. The length, diameter, and pore size of MC‐SNTs can be finely controlled in the range of 50 nm to 5 μm, 50 nm to 350 nm, and 2 nm to 3 nm by changing the molar ratio of P123 and SDA, the concentration of ammonia, and the length of carbon chain of SDAs, respectively. Observations based on transmission electron microscopy confirmed the role of P123 and ammonia in the self‐assembly of micelles of SDA. Compared with the one‐pot method reported previously, the aspect ratios (ARs; length/diameter) of obtained MC‐SNTs were tunable in a wide range of approximately 1 to 100. The tunable MC‐SNTs were used as dual drug‐delivery carriers for anticancer drug doxorubicin (Dox) and anti‐inflammatory drug ibuprofen (Ibu). Results of release behavior and toxicity to cancer cells of Dox–Ibu‐loaded MC‐SNTs with different ARs revealed that Dox and Ibu were successfully codelivered and did not interfere with each other. The produced MC‐SNTs with larger AR values of showed advantages in the amount of accumulated dual drugs, the duration time of release, and inhibition of the growth of HeLa cells.
Photostable, Oxygen‐Sensitive Optical Probe Based on a Homonuclear Terbium(III) Complex Covalently Bound to Functionalized Polydimethylsiloxane
Authors: Gaspar Rafael D. L. , Monteiro Jorge H. S. K. , Raimundo Ivo M. , Mazali Italo O. , Sigoli Fernando A.
Published: August 2015

A new oxygen‐sensitive optical probe based on the [Tb(3,5‐dcba)3]⋅1/2 H2O (3,5‐dcba=3,5‐dichlorobenzoate) complex, which is chemically attached to a phosphine‐oxide‐functionalized polydimethylsiloxane is presented. The hybrid material shows green emission and transparency in the visible range. The optically sensitive probe is photostable under excitation at 350 nm and shows the highest oxygen sensitivity, I0/I100 equal to 8.9 at 1 atm, among probes based on homonuclear lanthanide compounds. Furthermore its reversibility is demonstrated after several cycles ranging from 100 % N2 to 100 % O2 with response time of 8.5 s (N2→O2) and recovery time of 49.5 s (O2→N2).
Anion Binding Inside a Bambus[6]uril Macrocycle in Chloroform
Authors: Havel Vaclav , Sindelar Vladimir
Published: August 2015

Bambus[6]urils are a class of neutral anion receptors with outstanding binding properties in various solvents. The host–guest associations of bambusurils in aqueous environments have been investigated in detail, but their behavior in nonpolar solvents has not yet been reported. This paper presents isothermal calorimetry and 1H NMR data on the binding of dodecabenzylbambus[6]uril (Bn12BU[6]) to seventeen anions in chloroform. Under these conditions, anion inclusion in the macrocycle appears to be enthalpy‐driven, yielding complexes with stability constants of up to 1010 m−1. Perchlorate was optimally sized for inclusion in Bn12BU[6], while larger anions exhibited significantly lower affinity for the macrocycle. In addition, complexes of bambusuril and anions can be differentiated by NMR analysis based on the unique chemical shifts of characteristic peaks in their spectra. This finding was used to perform quantitative and qualitative analysis of multiple anion mixtures.
The Role of Mediation Strategies in Solving Interpersonal Conflicts
Authors: Khachaturova Milana R. , Poimanova Daria M.
Published: August 2015

We discuss the role of mediation strategies in solving interpersonal conflicts. Our results proved that the efficiency of the mediator's strategy differs depending on whether the conflict takes place in a separate dyad or in a dyad within a social group. The pressing strategy appeared to be the most effective when compared with others in solving conflicts that had arisen in a dyad within a social group. The facilitating strategy appeared to be the most effective in comparison with others in solving conflicts that had arisen in a separate dyad.
A Highly Efficient Heterogenized Iridium Complex for the Catalytic Hydrogenation of Carbon Dioxide to Formate
Authors: Park Kwangho , Gunasekar Gunniya Hariyanandam , Prakash Natarajan , Jung Kwang‐Deog , Yoon Sungho
Published: August 2015

A heterogenized catalyst on a highly porous covalent triazine framework was synthesized and characterized to have a coordination environment similar to that of its homogeneous counterpart. The catalyst efficiently converted CO2 into formate through hydrogenation with a turnover number of 5000 after 2 h and an initial turnover frequency of up to 5300 h−1; both of these values are the highest reported to date for a heterogeneous catalyst, which makes it attractive toward industrial application. Furthermore, the synthesized catalyst was found to be stable in air and was recycled by simple filtration without significant loss of catalytic activity.
Endothelial progenitor cells, defined by the simultaneous surface expression of VEGFR2 and CD133, are not detectable in healthy peripheral and cord blood
Authors: Lanuti Paola , Rotta Gianluca , Almici Camillo , Avvisati Giuseppe , Budillon Alfredo , Doretto Paolo , Malara Natalia , Marini Mirella , Neva Arabella , Simeone Pasquale , Di Gennaro Elena , Leone Alessandra , Falda Alessandra , Tozzoli Renato , Gregorj Chiara , Di Cerbo Melania , Trunzo Valentina , Mollace Vincenzo , Marchisio Marco , Miscia Sebastiano
Published: August 2015

Circulating endothelial cells (CEC) and their progenitors (EPC) are restricted subpopulations of peripheral blood (PB), cord blood (CB), and bone marrow (BM) cells, involved in the endothelial homeostasis maintenance. Both CEC and EPC are thought to represent potential biomarkers in several clinical conditions involving endothelial turnover/remodeling. Although different flow cytometry methods for CEC and EPC characterization have been published so far, none of them have reached consistent conclusions, therefore consensus guidelines with respect to CEC and EPC identification and quantification need to be established. Here, we have carried out an in depth investigation of CEC and EPC phenotypes in healthy PB, CB and BM samples, by optimizing a reliable polychromatic flow cytometry (PFC) panel. Results showed that the brightness of CD34 expression on healthy PB and CB circulating cells represents a key benchmark for the identification of CEC (CD45neg/CD34bright/CD146pos) respect to the hematopoietic stem cell (HSC) compartment (CD45dim/CD34pos/CD146neg). This approach, combined with a dual‐platform counting technique, allowed a sharp CEC enumeration in healthy PB (n = 38), and resulting in consistent CEC counts with previously reported data (median = 11.7 cells/ml). In parallel, by using rigorous PFC conditions, CD34pos/CD45dim/CD133pos/VEGFR2pos EPC were not found in any healthy PB or CB sample, since VEGFR2 expression was never detectable on the surface of CD34pos/CD45dim/CD133pos cells. Notably, the putative EPC phenotype was observed in all analyzed BM samples (n = 12), and the expression of CD146 and VEGFR2, on BM cells, was not restricted to the CD34bright compartment, but also appeared on the HSC surface. Altogether, our findings suggest that the previously reported EPC antigen profile, defined by the simultaneous expression of VEGFR2 and CD133 on the surface of CD45dim/CD34pos cells, should be carefully re‐evaluated and further studies should be conducted to redefine EPC features in order to translate CEC and EPC characterization into clinical practice. © 2015 International Society for Advancement of Cytometry
Pleural mass forming extramedullary hematopoiesis masquerading as a malignant neoplasm
Authors: Meykler Simon , Obstfeld Amrom , Jhala Nirag , Vergara Norge , Gupta Prabodh K.
Published: August 2015

Extramedullary hematopoiesis (EMH) represents the presence of immature hematopoietic elements and their differentiation into mature blood components outside of the medullary bone and may be seen in a variety of circumstances in the postnatal period, but is most strongly associated with disorders of the hematopoietic system. Postnatally, EMH is typically identified at sites of fetal hematopoiesis, the spleen, and liver, but occasional reports have identified it in nearly every tissue of the body. We report a case of EMH presenting as pleural mass, initially suspected to represent a neoplastic process in a patient with multiple comorbidities, including history of carcinoma, but without co‐existing hematologic disorder. On‐site evaluation of the fine‐needle aspiration specimen was initially suspicious for a malignant neoplasm, but further evaluation revealed the lesion to be a mass forming focus of non‐hepatosplenic EMH. In the era of increasing utilization of imaging, mass forming EMH is increasingly detected. When unsuspected, EMH may present a diagnostic challenge for the pathologist and may be confused for a neoplastic process. Diagn. Cytopathol. 2015;43:996–999. © 2015 Wiley Periodicals, Inc.