bluuebunny/crossref_metadata_2025_split huggingface dataset:
Inhibition by Inorganic Dopants of γ‐Alumina Chemical Weathering under Hydrothermal Conditions: Identification of Reactive Sites and their Influence in Fischer–Tropsch Synthesis
Authors: Abi Aad Jane , Courty Philippe , Decottignies Dominique , Michau Mathieu , Diehl Fabrice , Carrier Xavier , Marceau Eric 
Published: March 2017

AbstractUnderstanding how alumina degradation to boehmite AlOOH can be prevented under hydrothermal conditions is key to design more stable catalysts supported on alumina for Fischer–Tropsch synthesis. We compare the effect of four inorganic dopants to inhibit γ‐alumina chemical weathering under hydrothermal conditions: three metal ions: Mg2+, Zr4+, Ni2+, introduced by impregnation, and nonmetal Si, introduced by the grafting of tetraethyl orthosilicate. Boehmite is formed by a mechanism of dissolution–precipitation. A significant decrease of alumina weathering to boehmite is evidenced for all dopants. For metal ions, the thermal conversion of doped γ‐Al2O3 into an alumina‐rich mixed oxide or the coverage of the alumina surface by particles of a poorly soluble oxide such as NiO contribute to the stabilization of the solid. Alumina dissolution and degradation are only inhibited fully through Si grafting. IR spectra in the OH stretching region suggest that the most reactive alumina sites toward dissolution are basic Al−OH sites located on lateral facets that are blocked upon Si introduction. Fischer–Tropsch reactivity shows that Co catalysts prepared on Mg2+‐ and Si‐doped supports are less active or, at best, as active as a reference Co/γ‐Al2O3 catalyst, which is explained by a lower reducibility of CoO on doped supports. The Co catalyst prepared on Mg2+‐doped γ‐Al2O3 calcined at 900 °C exhibits the best combination of catalytic activity, ease of preparation, and hydrothermal stability.
Chemical Synthesis of Glycoproteins with the Specific Installation of Gradient‐Enriched 15N‐Labeled Amino Acids for Getting Insights into Glycoprotein Behavior
Authors: Minh Hien Nguyen , Izumi Masayuki , Sato Hajime , Okamoto Ryo , Kajihara Yasuhiro 
Published: March 2017

AbstractElucidating the effects of oligosaccharides on glycoprotein properties, such as local conformational changes, stability, and dynamics, has still been challenging. In this paper, a novel partial 15N‐labeling method for the amide backbone of a synthetic glycoprotein is proposed. Using solid‐phase peptide synthesis (SPPS) and native chemical ligation (NCL), thirteen 15N‐labeled amino acids were inserted at specific positions of the protein backbone, while intentionally varying the enrichment of 15N atoms. This idea discriminated even the same type of amino acid based on the intensities of 1H‐15N HSQC signals, combined with classic homonuclear TOCSY and NOESY methods, thus allowing for understanding the dynamics of the local conformation of a synthetic homogeneous glycoprotein. Results suggested that the attachment of an oligosaccharide of either a bi‐antennary complex‐type or a high‐mannose‐type did not disturb protein conformation. However, T1 values suggested that the oligosaccharide influenced dynamics at the local conformation. Temperature‐varied circular dichroism (CD) spectra and T1 values clearly indicated that oligosaccharides appeared to inhibit protein fluctuation or, in other words, stabilize protein structure. This insight into oligosaccharide behavior suggests some further effects on binding affinity between a glycoprotein and its receptor.
Selective Targeting of G‐Quadruplex Structures by a Benzothiazole‐Based Binding Motif
Authors: Buchholz Ina , Karg Beatrice , Dickerhoff Jonathan , Sievers‐Engler Adrian , Lämmerhofer Michael , Weisz Klaus 
Published: March 2017

AbstractA benzothiazole derivative was identified as potent ligand for DNA G‐quadruplex structures. Fluorescence titrations revealed selective binding to quadruplexes of different topologies including parallel, antiparallel, and (3+1) hybrid structures. The parallel c‐MYC sequence was found to constitute the preferred target with dissociation constants in the micromolar range. Binding of the benzothiazole‐based ligand to c‐MYC was structurally and thermodynamically characterized in detail by employing a comprehensive set of spectroscopic and calorimetric techniques. Job plot analyses and mass spectral data indicate noncooperative ligand binding to form complexes with 1:1 and 2:1 stoichiometries. Whereas stacking interactions are suggested by optical methods, NMR chemical shift perturbations also indicate significant rearrangements of both 5′‐ and 3′‐flanking sequences upon ligand binding. Additional isothermal calorimetry studies yield a thermodynamic profile of the ligand–quadruplex association and reveal enthalpic contributions to be the major driving force for binding. Structural and thermodynamic information obtained in the present work provides the basis for the rational development of benzothiazole derivatives as promising quadruplex binding agents.
Polyaniline‐Induced Arylation with Arenediazonium Salts Derived from Anilines
Authors: Hata Dai , Moriuchi Toshiyuki , Hirao Toshikazu , Amaya Toru 
Published: March 2017

AbstractA catalytic amount of a reduced form of polyaniline (a redox‐active π‐conjugated polymer) was found to induce C−H direct arylation of (hetero)arenes with arenediazonium salts prepared from anilines with methanesulfonic acid (MeSO3H) and tert‐butyl nitrite (tBuONO). The difficult part of this method is the coexistence of an oxidant and a reductant in this sequential diazotization and arylation system; diazotization requires weak oxidants such as alkyl nitrites, whereas the arylation is induced by a reductant. This was achieved by the careful control of the amount of tBuONO (1.0 equivalent) for the diazotization step, and sequential arylation using 5 mol % of the polyaniline. The reaction took place under mild conditions without any metals or strong bases at room temperature, and the amino group is a formal leaving group. The scope of the substrates demonstrates the versatility in the combination of anilines with a variety of functional groups and several (hetero)arenes. Two‐directional arylation for the synthesis of an unsymmetrical 1,4‐diarylated (furyl and pyrrolyl groups) benzene was achieved, using mono‐Boc‐protected 1,4‐phenylenediamine as a substrate. This shows potential for the synthesis of more complicated oligoarene compounds.
Exploring the Influence of the Aromaticity on the Anticancer and Antivascular Activities of Organoplatinum(II) Complexes
Authors: Zamora Ana , Pérez Sergio A. , Rothemund Matthias , Rodríguez Venancio , Schobert Rainer , Janiak Christoph , Ruiz José 
Published: March 2017

AbstractA series of new organometallic PtII complexes of the type [Pt(C^N)Cl(DMSO)] (C^N=N,N‐dimethyl‐1‐(2‐aryl)methanamine‐κ2C2,N; aryl=phenyl 2 a, biphenyl 2 b, p‐terphenyl 2 c, naphthyl 2 d, anthracenyl 2 e, or pyrenyl 2 f) have been synthesized to explore the influence of the aromaticity on their anticancer activity. The best performers, 2 b and d, are more active than cisplatin (CDDP) in epithelial ovarian carcinoma cells A2780, with 2 d having a higher selectivity factor than CDDP in all the tested cell lines. In addition, all the new compounds overcome the acquired resistance in A2780cisR cells and interestingly, show low micromolar IC50 values towards the triple negative breast cancer cell line MDA‐MB‐231 and the highly metastatic 518A2 melanoma cells. This study shows that the hydrophobicity, accumulation into cells, and metal levels on nuclear DNA for the complexes are consistent with their cytotoxicity. Complexes 2 b and d induce apoptosis in a caspase‐independent manner and suppress the intracellular ROS generation without modifying the mitochondria membrane potential. In addition, 2 a–f effectively inhibit angiogenesis in the endothelial cell line EA.hy926 at sub‐cytotoxic concentrations and 2 b and d show in vivo antivascular effects on the chorioallantoic membrane (CAM) of fertilized SPF‐eggs (SPF=specific‐pathogen‐free). Inhibition of tubulin polymerization and degeneration of cytoskeleton organization in 518A2 melanoma cells are presented as a preliminary mechanism of its antimetastatic activity.
Bifunctional Diaminoterephthalate Fluorescent Dye as Probe for Cross‐Linking Proteins
Authors: Wallisch Melanie , Sulmann Stefan , Koch Karl‐Wilhelm , Christoffers Jens 
Published: March 2017

AbstractDiaminoterephthalates are fluorescent dyes and define scaffolds, which can be orthogonally functionalized at their two carboxylate residues with functional residues bearing task specific reactive groups. The synthesis of monofunctionalized dyes with thiol groups for surface binding, an azide for click chemistry, and a biotinoylated congener for streptavidin binding is reported. Two bifunctionalized dyes were prepared: One with an azide for click chemistry and a biotin for streptavidin binding, the other with a maleimide for reaction with thiol and a cyclooctyne moiety for ligation with copper‐free click chemistry. In general, the compounds are red to orange, fluorescent materials with an absorption at about 450 nm and an emission at 560 nm with quantum yields between 2–41 %. Of particular interest is the maleimide‐functionalized compound, which shows low fluorescence quantum yield (2 %) by itself. After addition of a thiol, the fluorescence is “turned on”; quantum yield 41 %.
Investigations in Movement Behavior of Bulk Solids in Horizontal Ploughshare Mixers
Authors: Habermann Ralf 
Published: March 2017

AbstractBeim Feststoffmischen in horizontalen Pflugscharmischern ist das durch die Mischwerkzeuge initiierte Bewegungsverhalten der Mischungskomponenten elementar für die erzielbare Mischgüte. Dabei wird zwischen Schub‐, Schleuder‐ und Ringschichtmischen unterschieden. Bislang beruhen die gewonnenen Erkenntnisse auf phänomenologischen Beobachtungen. In dieser Arbeit wurde der Übergangsbereich vom Schub‐ zum Schleudermischen in horizontalen Pflugscharmischern untersucht. Als Schüttgüter wurden Kalksteinmehl, Polystyrol‐Granulat, Kochsalzgranulat und Laktose verwendet. Ein deutlicher Einfluss des Füllgrads konnte nachgewiesen werden.
Simulation of Heat Exchange in Vessels with Helical Coils and Influence of Stirrer Position
Authors: Stefan Alexander , Hindges Sascha , Schultz Heyko J. 
Published: March 2017

AbstractAgitated vessels are used for a wide range of applications, especially in chemical industry. This work is a pilot study on the influence of the stirrer installation height on the local as well as on the total heat flux with an immersed helical coil in an agitated vessel. A simplified geometrical model is used for observation of fundamental effects in contrast to a full mathematical model. The local heat flux, however, was observed to demonstrate the heat flux disparity along the coil. An optimum is proposed with the aim to maximize total heat flux and minimize tempering time.
Giant Radiolytic Dissolution Rates of Aqueous Ceria Observed in Situ by Liquid‐Cell TEM
Authors: Asghar Muhammad Sajid Ali , Inkson Beverley J. , Möbus Günter 
Published: March 2017

AbstractThe dynamics of cerium oxide nanoparticle aqueous corrosion are revealed in situ. We use innovative liquid‐cell transmission electron microscopy (TEM) combined with deliberate high‐intensity electron‐beam irradiation of nanoparticle suspensions. This enables life video‐recording of materials reactions in liquid, with nm resolution. We introduce image quantification to measure detailed rates of dissolution as a function of time and particle size to be compared with literature data. Giant dissolution rates, exceeding any previous reports for chemical dissolution rates at room temperature by many orders of magnitude, are discovered. The reasons for this accelerated dissolution are outlined, including the importance of the radiolysis of water preceding the ceria attack. Electron–water interaction generates radicals, ions, and hydrated electrons, which assist in hydration and reductive dissolution of oxide minerals. The presented methodology has the potential to become a novel accelerated testing procedure to compare multiple nanoscale materials for relative aqueous durability. The ceria–water system is of crucial importance for the fields of catalysis, abrasive polishing, environmental remediation, and as simulant for actinide oxide behaviour in contact with liquid for nuclear engineering.
Unveiling One‐Dimensional Supramolecular Structures Formed through π–π Stacking of Phenothiazines by Differential Pulse Voltammetry
Authors: Carvalho Fernando R. , Zampieri Eduardo H. , Caetano Wilker , Silva Rafael 
Published: March 2017

AbstractOrganic‐based nanomaterials can be self‐assembled by strong and directional intermolecular forces such as π–π interactions. Experimental information about the stability, size, and geometry of the formed structures is very limited for species that easily aggregate, even at very low concentrations. Differential pulse voltammetry (DPV) can unveil the formation, growth, and also the stability window of ordered, one‐dimensional, lamellar self‐aggregates formed by supramolecular π stacking of phenothiazines at micromolar (10−6 mol L−1) concentrations. The self‐diffusion features of the species at different concentrations are determined by DPV and used to probe the π staking process through the concept of the frictional resistance. It is observed that toluidine blue and methylene blue start to self‐aggregate around 9 μmol L−1, and that the self‐aggregation process occurs by one‐dimensional growth as the concentration of the phenothiazines is increased up to around 170 μmol L−1 for toluidine blue and 200 μmol L−1 for methylene blue. At higher concentrations, the aggregation process leads to structures with lower anisometry.
The building of the neocortex with non‐hyperpolarizing neurotransmitters
Authors: Ascenzi Matteo , Bony Guillaume 
Published: March 2017

ABSTRACTThe development of the neocortex requires the synergic action of several secreted molecules to achieve the right amount of proliferation, differentiation, and migration of neural cells. Neurons are well known to release neurotransmitters (NTs) in adult and a growing body of evidences describes the presence of NTs already in the embryonic brain, long before the generation of synapses. NTs are classified as inhibitory or excitatory based on the physiological responses of the target neuron. However, this view is challenged by the fact that glycine and GABA NTs are excitatory during development. Many reviews have described the role of nonhyperpolarizing GABA at this stage. Nevertheless, a global consideration of the inhibitory neurotransmitters and their downstream signaling during the embryonic cortical development is still needed. For example, taurine, the most abundant neurotransmitter during development is poorly studied regarding its role during cortical development. In the light of recent discoveries, we will discuss the functions of glycine, GABA, and taurine during embryonic cortical development with an emphasis on their downstream signaling. © 2017 Wiley Periodicals, Inc. Develop Neurobiol 77: 1023–1037, 2017
Worker brain development and colony organization in ants: Does division of labor influence neuroplasticity?
Authors: Kamhi J. Frances , Sandridge‐Gresko Aynsley , Walker Christina , Robson Simon K.A. , Traniello James F.A. 
Published: March 2017

ABSTRACTBrain compartment size allometries may adaptively reflect cognitive needs associated with behavioral development and ecology. Ants provide an informative system to study the relationship of neural architecture and development because worker tasks and sensory inputs may change with age. Additionally, tasks may be divided among morphologically and behaviorally differentiated worker groups (subcastes), reducing repertoire size through specialization and aligning brain structure with task‐specific cognitive requirements. We hypothesized that division of labor may decrease developmental neuroplasticity in workers due to the apparently limited behavioral flexibility associated with task specialization. To test this hypothesis, we compared macroscopic and cellular neuroanatomy in two ant sister clades with striking contrasts in worker morphological differentiation and colony‐level social organization: Oecophylla smaragdina, a socially complex species with large colonies and behaviorally distinct dimorphic workers, and Formica subsericea, a socially basic species with small colonies containing monomorphic workers. We quantified volumes of functionally distinct brain compartments in newly eclosed and mature workers and measured the effects of visual experience on synaptic complex (microglomeruli) organization in the mushroom bodies—regions of higher‐order sensory integration—to determine the extent of experience‐dependent neuroplasticity. We demonstrate that, contrary to our hypothesis, O. smaragdina workers have significant age‐related volume increases and synaptic reorganization in the mushroom bodies, whereas F. subsericea workers have reduced age‐related neuroplasticity. We also found no visual experience‐dependent synaptic reorganization in either species. Our findings thus suggest that changes in the mushroom body with age are associated with division of labor, and therefore social complexity, in ants. © 2017 Wiley Periodicals, Inc. Develop Neurobiol 77: 1072–1085, 2017
Implementation of a Simple Nanostructured Bio‐electrode with Immobilized Rhus Vernicifera Laccase for Oxygen Sensing Applications
Authors: Torrinha Álvaro , Montenegro Maria C. B. S. M. , Araújo Alberto N. 
Published: March 2017

AbstractIn this work a simple nanostructured direct‐electron transfer bio‐electrode based on tree laccase from Rhus vernicifera is described. The electrode was implemented on a 2 mm diameter graphite mine casted with a reduced graphene surface presenting the specific capacitance of 195.8 F g−1. About 10 μl of mixture between 25 mg mL−1 laccase suspension and 5 mg mL−1 single‐walled carbon nanotubes in 2 % SDS is dropped over the surface followed by 5 μl of the biological friendly tetrakis(2,3‐dihydroxypropyl)‐silane monomer sol to provide physical entrapment in a silica matrix after gelation. The rigidity of enzyme encapsulation allowed to obtain a constant enzyme turnover of about 16 min−1 in the extended pH range of 6.0‐7.5, being the activity almost proportional to the temperature used in the interval between 25 and 40 °C. The graphite‐graphene/SWCNT‐laccase/sol‐gel electrode enabled a proportional response to molecular oxygen up to the concentration of 0.45 mmol L−1 and is capable to generate the maximum power of 4.5 μW cm−2 at 0.250 V vs the AgCl/Ag reference electrode in quiescent oxygen saturated solution.
Reproductive and Appetite Hormones and Bulimic Symptoms during Midlife
Authors: Baker Jessica H. , Peterson Claire M. , Thornton Laura M. , Brownley Kimberly A. , Bulik Cynthia M. , Girdler Susan S. , Marcus Marsha D. , Bromberger Joyce T. 
Published: March 2017

AbstractEating disorders and related symptoms occur during midlife; however, little is known about their aetiology. It has been hypothesised that perimenopause represents a window of vulnerability for the development or exacerbation of eating disorder symptomatology because, like puberty, perimenopause is a period of reproductive hormone change. We compared symptoms of bulimia nervosa (bulimic symptomatology) assessed via mean scores on a self‐report questionnaire in premenopausal and perimenopausal women. We also examined the association between hormone concentrations (reproductive/appetite) and bulimic symptomatology. No mean differences in bulimic symptomatology were observed between premenopause and perimenopause. However, there was a significant positive association between leptin and binge eating. Although no significant associations between reproductive hormones and bulimic symptomatology were observed, additional research is needed to provide definitive information. It is essential to learn more about the aetiology of eating disorders and related symptomatology across the lifespan in order to develop age‐relevant treatment and prevention programs. Copyright © 2017 John Wiley & Sons, Ltd and Eating Disorders Association.
Subaerial gravel size measurement using topographic data derived from a UAV‐SfM approach
Authors: Woodget Amy S. , Austrums Robbie 
Published: March 2017

AbstractAccurate and reliable methods for quantifying grain size are important for river science, management and in various other sedimentological settings. Remote sensing offers methods of quantifying grain size, typically providing; (a) coarse outputs (c. 1 m) at the catchment scale where individual grains are at subpixel level, or; (b) fine resolution outputs (c. 1 mm) at the patch scale. Recently, approaches using unmanned aerial vehicles (UAVs) have started to fill the gap between these scales, providing hyperspatial resolution data (< 10 cm) over reaches a few hundred metres in length, where individual grains are at suprapixel level. This ‘mesoscale’ is critical to habitat assessments. Most existing UAV‐based approaches use two‐dimensional (2D) textural variables to predict grain size. Validation of results is largely absent however, despite significant differences in platform stability and image quality obtained by manned aircraft versus UAVs. Here, we provide the first quantitative assessment of the accuracy and precision of grain size estimates produced from a 2D image texture approach. Furthermore, we present a new method which predicts subaerial gravel size using three‐dimensional (3D) topographic data derived from UAV imagery. Data is collected from a small gravel‐bed river in Cumbria, UK. Results indicate that our new topographic method gives more accurate measures of grain size (mean residual error ‐0.0001 m). Better results for the image texture method may be precluded by our choice of texture measure, the scale of analysis or the effects of image blur resulting from an inadequate camera gimbal. We suggest that at our scale of assessment, grain size is more strongly related to 3D variation in elevation than to the 2D textural patterns expressed within the imagery. With on‐going improvements, our novel method has potential as the first grain size quantification approach where a trade‐off between coverage and resolution is not necessary or inherent. Copyright © 2017 John Wiley & Sons, Ltd.
Impact of rainfall pattern on interrill erosion process
Authors: Wang Bin , Steiner Jean , Zheng Fenli , Gowda Prasanna 
Published: March 2017

AbstractThe impact of rainfall pattern on the interrill erosion process is not fully understood despite its importance. Systematic rainfall simulation experiments involving various rainfall intensities, stages, intensity sequences, and surface cover conditions were conducted in this study to investigate their effects on the interrill erosion process. Five rainfall patterns designed with the same total kinetic energy/precipitation (increasing, decreasing, rising–falling, falling–rising and constant patterns) were randomly delivered to a pre‐wet clay loam soil surface at a 10° slope gradient. Significant differences in soil losses were observed among the different rainfall patterns and stages, but there was no obvious difference in runoff. Kinetic energy flux (KEr) was a governing factor for interrill erosion, and constant rainfall pattern (CST) produced nine times greater soil loss than runs with no KEr. Varied‐intensity patterns had a profound effect on raindrop‐induced sediment transport processes; path analysis results indicated that said effect was complex, interactive and intensity‐dependent. Low hydraulic parameter thresholds further indicated that KErwas the dominant factor in detaching soil particles, while overland flow mainly contributed to transporting the pre‐detached particles. This study not only sheds light on the mechanism of interrill sediment transport capacity and detachability, but also may provide a useful database for developing event‐based interrill erosion prediction models. Copyright © 2017 John Wiley & Sons, Ltd.