bluuebunny/crossref_metadata_2025 huggingface dataset:
Characteristics of a rocket‐triggered lightning flash with large stroke number and the associated leader propagation
Authors: Sun Zhuling , Qie Xiushu , Jiang Rubin , Liu Mingyuan , Wu Xueke , Wang Zhichao , Lu Gaopeng , Zhang Hongbo
Published: November 2014

A negative lightning flash with 16 leader‐return stroke sequences, triggered in the summer of 2013 using the classical rocket‐and‐wire triggering technique, was examined with simultaneous two‐dimensional (2D) imaging of very high‐frequency (VHF) radiation sources, channel‐base current measurement, broadband electric field waveforms and high‐speed video images. A total of 28.0 C negative charge was transferred to ground during the whole flash, and the charge transferred during the initial stage was 4.9 C, which is the weakest among the triggered lightning flashes at the SHandong Artificially Triggering Lightning Experiment (SHATLE). The peak current of 16 return strokes ranged from 5.8 to 32.5 kA with a geometric mean of 14.1 kA. The progression of upward positive leader and downward negative (dart or dart‐stepped) leaders was reproduced visually by using an improved short‐baseline VHF lightning location system with continuous data recording capability. The upward positive leader was mapped immediately from the tip of the metal wire during the initial stage, developing at a speed of about 104 m/s without branches. The upward positive leader and all the 14 negative leaders captured by the 2D imaging system propagated along the same channel with few branches inside the cloud, which might be the reason for the relatively small charge transfer. The 2D imaging results also show that dart leaders may transform into dart‐stepped leaders after a long time interval between successive strokes.
Intensified anticyclonic anomaly over the western North Pacific during El Niño decaying summer under a weakened Atlantic thermohaline circulation
Authors: Chen Wei , Lu Riyu , Dong Buwen
Published: November 2014

It has been well documented that there is an anticyclonic anomaly over the western North Pacific (WNPAC, hereafter) during El Niño decaying summer. This El Niño‐WNPAC relationship is greatly useful for the seasonal prediction of summer climate in the WNP and East Asia. In this study, we investigate the modification of the El Niño‐WNPAC relationship induced by a weakened Atlantic thermohaline circulation (THC) in a water‐hosing experiment. The results suggest that the WNPAC during the El Niño decaying summer, as well as the associated precipitation anomaly over the WNP, is intensified under the weakened THC. On the one hand, this intensification is in response to the increased amplitude and frequency of El Niño events in the water‐hosing experiment. On the other hand, this intensification is also because of greater climatological humidity over the western to central North Pacific under the weakened THC. We suggest that the increase of climatological humidity over the western to central North Pacific during summer under the weakened THC is favorable for enhanced interannual variability of precipitation, and therefore favorable for the intensification of the WNPAC during El Niño decaying summer. This study suggests a possible modulation of the El Niño–Southern Oscillation‐WNP summer monsoon relationship by the low‐frequency fluctuation of Atlantic sea surface temperature. The results offer an explanation for the observed modification of the multidecadal fluctuation of El Niño‐WNPAC relationship by the Atlantic multidecadal oscillation.
Why logarithmic? A note on the dependence of radiative forcing on gas concentration
Authors: Huang Yi , Bani Shahabadi Maziar
Published: November 2014

Line‐by‐line radiative transfer computations show that the logarithmic dependence of radiative forcing on gas concentration not only applies to broadband irradiation fluxes such as in the well‐known case of the CO2 forcing, but also applies to the spectral radiance change due to both CO2 and other gases, such as H2O. The logarithmic relationship holds for monochromatic radiance requires an explanation beyond the conventional ideas based on the spectroscopic features of the gas absorption lines. We show that the phenomenon can be explained by an Emission Layer Displacement Model, which describes the radiance response to gas perturbation under normal atmospheric conditions such as temperature linearly varying with height and gas concentration exponentially decaying with height.
Global energy and water balance: Characteristics from Finite‐volume Atmospheric Model of the IAP/LASG (FAMIL1)
Authors: Zhou Linjiong , Bao Qing , Liu Yimin , Wu Guoxiong , Wang Wei‐Chyung , Wang Xiaocong , He Bian , Yu Haiyang , Li Jiandong
Published: November 2014

This paper documents version 1 of the Finite‐volume Atmospheric Model of the IAP/LASG (FAMIL1), which has a flexible horizontal resolution up to a quarter of 1°. The model, currently running on the “Tianhe 1A” supercomputer, is the atmospheric component of the third‐generation Flexible Global Ocean‐Atmosphere‐Land climate System model (FGOALS3) which will participate in the Coupled Model Intercomparison Project Phase 6 (CMIP6). In addition to describing the dynamical core and physical parameterizations of FAMIL1, this paper describes the simulated characteristics of energy and water balances and compares them with observational/reanalysis data. The comparisons indicate that the model simulates well the seasonal and geographical distributions of radiative fluxes at the top of the atmosphere and at the surface, as well as the surface latent and sensible heat fluxes. A major weakness in the energy balance is identified in the regions where extensive and persistent marine stratocumulus is present. Analysis of the global water balance also indicates realistic seasonal and geographical distributions with the global annual mean of evaporation minus precipitation being approximately 10−5 mm d−1. We also examine the connections between the global energy and water balance and discuss the possible link between the two within the context of the findings from the reanalysis data. Finally, the model biases as well as possible solutions are discussed.
Koksma‐Hlawka Inequality
Authors: Hickernell Fred J.
Published: November 2014

The Koksma–Hlawka inequality is a tight error bound on the approximation of an integral by the sample average of integrand values. The integration error is bounded by a product of two terms, the discrepancy of the sample points, , and the variation of the integrand,V(g). These two quantities measure the quality of the sample points and the roughness of the integrand, respectively. The Koksma–Hlawka inequality plays a key role in the development of quasi–Monte Carlo methods. Such methods replace simple random sample points by low discrepancy points. The Koksma–Hlawka inequality has also influenced the study of experimental design and led to the creation of UNIFORM DESIGNS.
Central Limit Theorems, Convergence Rates for
Authors: Nadarajah S. , Kotz S.
Published: November 2014

In this short entry, rates of convergence associated with central limit theorems are discussed. Specifically, the Liapunov bounds and the Berry‐Esseen bounds for the absolute value of the difference of the distribution of the standardized sums ofnrandom variables and the standard normal distribution are briefly described.
From Basel II to Solvency II‐Risk Management in the Insurance Sector
Authors: Rudolf Markus , Frenkel Michael
Published: November 2014

Basel II has not only changed the risk‐management standards in the banking system dramatically, it has also affected the competitive positions of different banking systems. This is due to the fact, that Basel II has shifted banking closer toward capital markets and away from banking institutions. Consequently, we did observe an increased significance of the Anglo‐Saxon banking sector and less significance of the banking systems in Japan and Germany. In the insurance sector, a regulatory framework called Solvency II was launched in 2002. Solvency II is comparable to Basel II with regard to many aspects. The view which is advocated here is therefore, that developments similar to those which have been observed in the banking system might apply to the global insurance industry in the next decade.
Fraud in Insurance
Authors: Guillen Montserrat , Ayuso Mercedes
Published: November 2014

Insurance fraud occurs when the insurer does not know all the facts about the insured and the claim, and when the fraudster believes that some monetary benefits can be gained by distortion of such facts. We explain how fraud can be fought with deterrence and detection, and present several ways to control fraud, specialized investigation units, statistical analysis of claims information, and fraud detection methods, together with the ways for evaluation of their performance and some hints for their practical implementation. Also, we give an overview of the claims handling process. We describe various types of fraud currently encountered in insurance and give examples.
Individual Risk Model: Examples
Authors: Vernic Raluca
Published: November 2014

For an insurance company, evaluating the aggregate claims distribution is generally not an easy task. Among various methods used for such computations, recursive methods have the advantage of giving accurate values with considerable savings in the computing time. The purpose of this article is to give an overview of such exact and approximative recursions for the individual risk model.
Nonlife Insurance Markets
Authors: Holtan Jon
Published: November 2014

The article describes market characteristics and operational business strategies in nonlife insurance from a risk assessment point of view. The first part highlights general market characteristics like regulations and legislations; profitability and underwriting cycles; market rivalry and entry dynamics; as well as other more specific characteristics like moral hazard, adverse risk selection, and uninsurable risks. The second part describes pricing and underwriting; distribution and sales; and risk and capital management as three main competitive market levers of nonlife insurance suppliers. Market outlook and trends are finally commented.
Longevity Risk and Life Annuities
Authors: Milevsky Moshe A.
Published: November 2014

Longevity risk is faced by individuals, corporations, as well as society and their governments. This brief article reviews the various dimensions and aspects of longevity risk as they relate to the market for life annuities and mortality‐contingent claims. The main argument used is that regardless of one's perspective on longevity risk, this field will continue to provide fertile ground for advanced research for many, albeit uncertain, years to come.
Life Insurance Markets
Authors: Driver Rebecca
Published: November 2014

This section reviews the life insurance market, looking at both protection and investment policies. It discusses the role of life insurance products in helping households smooth their consumption and the impact of the bequest motive. It considers whether households are under‐ or overinsured, for example, in the context of mandatory annuitization. It discusses the extent to which individuals can commit to life insurance policies and the impact of this on policy design. It looks at longevity risk and investigates the extent to which adverse selection exists in annuity markets. Finally, it discusses distribution and the impact of the Internet in reducing search costs.
Lévy Processes
Authors: Kella Offer
Published: November 2014

This entry contains an overview of Lévy processes and their multidimensional extensions, which are processes having stationary, independent increments that are continuous in probability thereby having versions with almost surely right continuous sample paths. Special cases are Poisson processes, Brownian motions and compound Poisson processes. Infinite divisibility, which is closely related to Lévy processes, is defined and discussed as well as the reflected version of these processes and associated martingales, both in the one‐ and multidimensional cases. Markov additive processes, which are extensions of Lévy process, as well as their reflected versions and associated martingales are introduced as well.
Eye‐Search: A web‐based therapy that improves visual search in hemianopia
Authors: Ong Yean‐Hoon , Jacquin‐Courtois Sophie , Gorgoraptis Nikos , Bays Paul M. , Husain Masud , Leff Alexander P.
Published: November 2014

Persisting hemianopia frequently complicates lesions of the posterior cerebral hemispheres, leaving patients impaired on a range of key activities of daily living. Practice‐based therapies designed to induce compensatory eye movements can improve hemianopic patients' visual function, but are not readily available. We used a web‐based therapy (Eye‐Search) that retrains visual search saccades into patients' blind hemifield. A group of 78 suitable hemianopic patients took part. After therapy (800 trials over 11 days), search times into their impaired hemifield improved by an average of 24%. Patients also reported improvements in a subset of visually guided everyday activities, suggesting that Eye‐Search therapy affects real‐world outcomes.
Diastereoselective Synthesis of Tetrahydrofurano‐ and Tetrahydropyrano‐dihydropyrroles Containing N,O‐Acetal Moieties via Rhodium‐Catalyzed Transannulation of N‐Sulfonyl‐1,2,3‐triazoles with Oxacycloalkenes
Authors: Kim Cheol‐Eui , Park Youngchul , Park Sangjune , Lee Phil Ho
Published: November 2014

Diastereoselective synthesis of tetrahydro‐furanodihydropyrroles and tetrahydropyranodihydropyrroles containing N,O‐acetal moieties is reported via rhodium‐catalyzed denitrogenative transannulation of N‐sulfonyl‐1,2,3‐triazoles with oxacycloalkenes. A multitude of functionalized pyrroles possessing hydroxyalkyl group at C3‐position could be prepared via Rh‐catalyzed denitrogenative transannulation/acid‐catalyzed ring‐opening reaction. A three component, one‐pot method is also achieved starting from terminal alkynes, tosyl azides, and dihydrofurans.

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Alkynylboranes: A Practical Approach by Zinc‐Catalyzed Dehydrogenative Coupling of Terminal Alkynes with 1,8‐Naphthalenediaminatoborane
Authors: Tsuchimoto Teruhisa , Utsugi Hirokazu , Sugiura Tetsuya , Horio Shin
Published: November 2014

Under zinc Lewis acid catalysis, terminal alkynes coupled dehydrogenatively with 1,8‐naphthalenediaminatoborane [HB(dan)]. It is important to note that the resulting alkynylboranes with an C(sp)B(dan) bond are isolable by column chromatography on silica gel (SiO2) and are usable as coupling partners for palladium‐ and copper‐catalyzed cross‐coupling reactions with (hetero)aryl halides.

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Totalsynthese des geschützten Aglycons von Fidaxomicin (Tiacumicin B, Lipiarmycin A3)
Authors: Miyatake‐Ondozabal Hideki , Kaufmann Elias , Gademann Karl
Published: November 2014

Fidaxomicin, auch Tiacumicin B oder Lipiarmycin A3 genannt, ist ein neuartiges makrocyclisches Antibiotikum, das klinisch gegen Clostridium‐difficile‐Infektionen eingesetzt wird. Dieser Naturstoff zeigt zudem eine exzellente Aktivität gegen multiresistente Stämme von Mycobacterium tuberculosis. Trotz dieses attraktiven biologischen Profils gab es bisher noch keine Berichte über eine Totalsynthese. Hier berichten wir über die enantioselektive Synthese des zentralen 18‐gliedrigen Makrolactons von Fidaxomicin. Die Schlüsselschritte der Synthese sind eine Ringschlussmetathese zwischen einem terminalen Olefin und einem Dienoat, eine vinyloge Mukaiyama‐Aldolreaktion und eine Stille‐Kupplung zweier sterisch anspruchsvoller Substrate. Der Ansatz beruht auf drei mittelgroßen Fragmenten, was eine flexible und gleichzeitig konvergente Syntheseroute ermöglicht.
Ein alternativer Mechanismus für die Cobalt‐katalysierte Isomerisierung von terminalen Alkenen zu (Z)‐2‐Alkenen
Authors: Schmidt Anastasia , Nödling Alexander R. , Hilt Gerhard
Published: November 2014

Die Cobalt‐katalysierte selektive Isomerisierung von terminalen Alkenen hin zum thermodynamisch weniger stabilen (Z)‐2‐Alken bei Raumtemperatur läuft über einen neuartigen Mechanismus ab, der die Übertragung eines Wasserstoffs von einem Ph2PH‐Liganden zur Ausgangsverbindung und die Bildung eines Phospheniumkomplexes, aus dem durch eine 1,2‐H‐Wanderung der Ph2PH‐Komplex regeneriert wird, einschließt.
Biomimetic Synthesis: Discovery of Xanthanolide Dimers
Authors: Shang Hai , Liu Junhua , Bao Ruiyang , Cao Yu , Zhao Kun , Xiao Chengqian , Zhou Bing , Hu Lihong , Tang Yefeng
Published: November 2014

Starting from xanthatin, the biomimetic synthesis of 4β,5β‐epoxyxanthatin‐1α,4α‐endoperoxide, a novel monomeric xanthanolide, has been achieved. Moreover, four unprecedented xanthanolide dimers were synthesized by three different dimerizations of xanthatin, either in a head‐to‐head or head‐to‐tail fashion. Notably, these dimeric compounds were firstly identified as artifacts in the laboratory, and two of them, mogolides A and B, proved to be natural products present in the Xanthium mogolium Kitag plant.
Paraformaldehyde and Methanol as C1 Feedstocks in Metal‐Catalyzed CC Couplings of π‐Unsaturated Reactants: Beyond Hydroformylation
Authors: Sam Brannon , Breit Bernhard , Krische Michael J.
Published: November 2014

Ruthenium‐catalyzed reductive couplings of paraformaldehyde with dienes, alkynes, and allenes provide access to products of hydrohydroxymethylation that cannot be formed selectively under the conditions of hydroformylation. In certain cases, the regioselectivity of the CC coupling can be inverted by using nickel catalysts. With iridium catalysts, methanol engages in redox‐neutral regioselective hydrohydroxymethylations.
Switching of Bacterial Adhesion to a Glycosylated Surface by Reversible Reorientation of the Carbohydrate Ligand
Authors: Weber Theresa , Chandrasekaran Vijayanand , Stamer Insa , Thygesen Mikkel B. , Terfort Andreas , Lindhorst Thisbe K.
Published: November 2014

The surface recognition in many biological systems is guided by the interaction of carbohydrate‐specific proteins (lectins) with carbohydrate epitopes (ligands) located within the unordered glycoconjugate layer (glycocalyx) of cells. Thus, for recognition, the respective ligand has to reorient for a successful matching event. Herein, we present for the first time a model system, in which only the orientation of the ligand is altered in a controlled manner without changing the recognition quality of the ligand itself. The key for this orientational control is the embedding into an interfacial system and the use of a photoswitchable mechanical joint, such as azobenzene.
Robust Sliding Mode Control Design for Mismatched Uncertain Systems with a Performance
Authors: Valilou Shirin , Khosrowjerdi Mohammad J.
Published: November 2014

This paper presents an optimal design of sliding mode controller with a
constraint for a general class of uncertain systems. The method proposed here takes into account nonmatching disturbance signals and nonmatching system model uncertainties. Without requiring any transformation or restriction on the input matrix, our approach leads to a straightforward design which can be easily solved by using linear matrix inequality (LMI) technique. By solving the problem of optimal sliding motion design with some quadratic constraints based on LMIs, a mixed
approach is presented to reduce the effect of uncertainties and disturbances on the sliding motion. Finally, we give simulation results for controlling a chemical reactor to illustrate the applicability of the proposed scheme for uncertain time‐delay systems or mismatched uncertain systems.
An Intelligent Design for a PID Controller for Nonlinear Systems
Authors: Huang Chung‐Neng , Chung Aaron
Published: November 2014

The proportional integral derivative (PID) controller is the most frequently used controller design for industrial applications because of its favorable response and simplicity of adjustment. However, PID manual tuning is traditionally based on engineering experience, and adjusting nonlinear or unknown systems is extremely difficult. In promoting an intelligent controller design theory that can be applied to the control of various systems, this paper proposes a nonlinear control design method that involves determining the optimal solution and obtaining the transfer function of an unknown system by using sequential quadratic programming. In addition, this paper presents a case study of an induction motor V/F speed control to demonstrate the effectiveness of the proposed method based on MATLAB simulation. The results prove that the design of the proposed intelligent PID controller is more robust than traditional controller designs.
Change in pharmacokinetic behavior of intravenously administered midazolam due to increased CYP3A2 expression in rats treated with menthol
Authors: Nagai Katsuhito , Suzuki Sho , Yamamura Ayumi , Konishi Hiroki
Published: November 2014

Menthol is used widely as a constituent of functional foods and chemical drugs. The present study investigated changes in the pharmacokinetic behavior of intravenously administered midazolam (MDZ), a probe for CYP3A, when rats were treated with menthol. The study also examined which isoforms of CYP3A1 and 3A2 were menthol‐inducible and contributed to the altered disposition of midazolam. Menthol was administered intraperitoneally to rats once daily for 3 days at a dose of 10 mg/kg, while the control rats received vehicle alone. The pharmacokinetic examination of i.v. administered midazolam revealed that serum midazolam concentrations at each sampling point were lower in the menthol‐treated rats than in the control rats. Regarding the pharmacokinetic parameters of the menthol‐treated group, the area under the curve (AUC) was decreased significantly and, correspondingly, the elimination rate constant at terminal phase (ke) was increased significantly without significant changes in the volume of distribution at steady state (Vdss). The metabolic production of the 1′‐hydroxylated and 4′‐hydroxylated forms of MDZ by hepatic microsomes was significantly greater in the menthol‐treated rats than in the control rats. The expression levels of mRNA and protein for hepatic CYP3A2 were more than 2.5‐fold higher than the control levels when the rats were treated with menthol, whereas no changes were observed in the expression levels of CYP3A1. These results indicate that menthol enhanced the elimination clearance of midazolam by inducing hepatic CYP3A2 and that careful attention should be paid when menthol is ingested in combination with drugs that act as substrates for CYP3A. Copyright © 2014 John Wiley & Sons, Ltd.
DNA mechatronic devices switched by K+ and by Sr2+ are structurally, topologically, and electronically distinct
Authors: Huang Yu Chuan , Yu Hua‐Zhong , Sen Dipankar
Published: November 2014

DNAs and RNAs that fold via the formation of guanine quartets form G‐quadruplexes that are often highly diverse in terms of architecture and topology. G‐quadruplexes are specifically stabilized by metal cations such as K+ and Sr2+, but not Li+. DNA duplexes that incorporate two separated clusters of G•G mismatches (“P‐duplexes”) can function as electronic switches, capable of toggling reversibly from a poorly conductive conformer (E) with only Li+ in the solution to a G‐quadruplex incorporating conformer of higher conductivity (C) in the presence of K+. Herein, we report results from fluorescence energy transfer, circular dichroism, charge conduction, and chemical footprinting experiments, which cumulatively demonstrate that P‐duplex E↔C transitions are genuinely mechatronic, with causally coupled mechanical and electronic states. We show, further, that the K+‐ and the Sr2+‐fuelled E↔C switching of a given P‐duplex are structurally, topologically, and electronically distinct from each other. A single DNA P‐duplex can thus exist in at least three distinguishable mechatronic states in aqueous solution. © 2014 Wiley Periodicals, Inc. Biopolymers 103: 460–468, 2015.
Effect of T3 hormone on neural differentiation of human adipose derived stem cells
Authors: Razavi Shahnaz , Mostafavi Fatemeh Sadat , Mardani Mohammad , Zarkesh Esfahani Hamid , Kazemi Mohammad , Esfandiari Ebrahim
Published: November 2014

Human adult stem cells, which are capable of self‐renewal and differentiation into other cell types, can be isolated from various tissues. There are no ethical and rejection problems as in the case of embryonic stem cells, so they are a promising source for cell therapy. The human body contains a great amount of adipose tissue that contains high numbers of mesenchymal stem cells. Human adipose‐derived stem cells (hADSCs) could be easily induced to form neuron‐like cells, and because of its availability and abundance, we can use it for clinical cell therapy. On the other hand, T3 hormone as a known neurotropic factor has important impressions on the nervous system. The aim of this study was to explore the effects of T3 treatment on neural differentiation of hADSCs.

ADSCs were harvested from human adipose tissue, after neurosphere formation, and during final differentiation, treatment with T3 was performed. Immunocytochemistry, real‐time RT‐PCR, Western blotting techniques were used for detection of nestin, MAP2, and GFAP markers in order to confirm the effects of T3 on neural differentiation of hADSCs. Our results showed an increase in the number of glial cells but reduction in neuronal cells number fallowing T3 treatment. Copyright © 2014 John Wiley & Sons, Ltd.
Tuning Surface Properties and Catalytic Performances of Pt–Ru Bimetallic Nanoparticles by Thermal Treatment
Authors: Zhang Hua , Zheng Zhijie , Ma Changjian , Zheng Jinbao , Zhang Nuowei , Li Yunhua , Chen Bing H.
Published: November 2014

The surface structure and catalytic properties of Pt–Ru bimetallic catalysts with identical bulk composition can be continuously tuned by treatment at different temperatures. The activity of these catalysts in CO oxidation was positively related to the treatment temperature, but the opposite trend was observed for the solvent‐free oxidation of benzyl alcohol. It was found that migration of Pt to the surface occurred when the treatment temperature was increased. During this process, the surface of the Pt–Ru nanoparticles changed from a Ru‐rich surface to a Pt‐rich surface. The electronic interactions between Pt and Ru became stronger with increased treatment temperature, and the amount of oxidized Pt species on the surface was higher for the samples treated at higher temperatures. Therefore, oxidized Pt species are more active in CO oxidation than other metallic species, but are less active in the selective oxidation of benzyl alcohol.
Advanced TEMKIN Reactor: Testing of Industrial Eggshell Catalysts on the Laboratory Scale
Authors: Kuhn Martin , Lucas Martin , Claus Peter
Published: November 2014

In a variety of reactions in the chemical industry, eggshell catalysts with a thin active layer are applied; they are often crushed for laboratory testing. The destruction of the shell can be avoided by a special reactor design. The presented advanced TEMKIN reactor is a further development of the reactor system for testing eggshell catalysts on the laboratory scale published by Temkin and Kul'kova in 1969. It is suitable for kinetic studies and for the detailed investigation of deactivation processes, as shown on the example of selective hydrogenation of acetylene.
A Template‐Free Method for Preparation of Cobalt Nanoparticles Embedded in N‐Doped Carbon Nanofibers with a Hierarchical Pore Structure for Oxygen Reduction
Authors: Wang Shuguang , Cui Zhentao , Cao Minhua
Published: November 2014

Designing and preparing porous materials without using any templates is a challenge. Herein, single‐nozzle electrospinning technology coupled with post pyrolysis is applied to prepare cobalt nanoparticles embedded in N‐doped carbon nanofibers with a hierarchical pore structure (HP‐Co‐NCNFs). The resultant HP‐Co‐NCNFs have lengths up to several millimeters with an average diameter of 200 nm and possess abundant micro/meso/macropores on both the surface and within the fibers. Such a microstructure endows the surface area as high as 115 m2 g−1. When used as an electrocatalyst for the oxygen reduction reaction (ORR), the HP‐Co‐NCNFs exhibit outstanding electrochemical performance in terms of activity, methanol tolerance, and durability. The hierarchically porous structure and high surface area can effectively decrease the mass transport resistance and increase the exposed ORR active sites. The sufficient amount of exposed ORR active sites along with accessible transport channel and enhanced electrical conductivity may be responsible for the good electrocatalytic performance.
Core–Shell LiFePO4/Carbon‐Coated Reduced Graphene Oxide Hybrids for High‐Power Lithium‐Ion Battery Cathodes
Authors: Ha Sung Hoon , Lee Yun Jung
Published: November 2014

Core‐shell carbon‐coated LiFePO4 nanoparticles were hybridized with reduced graphene (rGO) for high‐power lithium‐ion battery cathodes. Spontaneous aggregation of hydrophobic graphene in aqueous solutions during the formation of composite materials was precluded by employing hydrophilic graphene oxide (GO) as starting templates. The fabrication of true nanoscale carbon‐coated LiFePO4‐rGO (LFP/C‐rGO) hybrids were ascribed to three factors: 1) In‐situ polymerization of polypyrrole for constrained nanoparticle synthesis of LiFePO4, 2) enhanced dispersion of conducting 2D networks endowed by colloidal stability of GO, and 3) intimate contact between active materials and rGO. The importance of conducting template dispersion was demonstrated by contrasting LFP/C‐rGO hybrids with LFP/C‐rGO composites in which agglomerated rGO solution was used as the starting templates. The fabricated hybrid cathodes showed superior rate capability and cyclability with rates from 0.1 to 60 C. This study demonstrated the synergistic combination of nanosizing with efficient conducting templates to afford facile Li+ ion and electron transport for high power applications.
Tris‐Heteroleptic Ruthenium–Dipyrrinate Chromophores in a Dye‐Sensitized Solar Cell
Authors: Li Guocan , Hu Ke , Robson Kiyoshi C. D. , Gorelsky Serge I. , Meyer Gerald J. , Berlinguette Curtis P. , Shatruk Michael
Published: November 2014

Two novel tris‐heteroleptic Ru–dipyrrinates were prepared and tested as sensitizers in the dye‐sensitized solar cell (DSSC). Under AM 1.5 sunlight, DSSCs employing these dyes achieved power conversion efficiencies (PCEs) of 3.4 and 2.2 %, substantially exceeding the value achieved previously with a bis‐heteroleptic dye (0.75 %). As shown by electrochemical measurements and DFT calculations, the improved PCEs stem from the synthetically tuned electronic structure, which affords more negative excited state redox potentials and favorable electron injection into the TiO2 conduction band. Electron injection was quantified by nanosecond transient absorption spectroscopy, which revealed that the highest injection yield is achieved with the dye that acts as the strongest photoreductant.
{Sn10[Si(SiMe3)3]4}2−: A Highly Reactive Metalloid Tin Cluster with an Open Ligand Shell
Authors: Schrenk Claudio , Winter Florian , Pöttgen Rainer , Schnepf Andreas
Published: November 2014

The reaction of a SnICl solution with LiSi(SiMe3)3 gave the anionic metalloid tin cluster {Sn10[Si(SiMe3)3]4}2− (7) in good yield. The arrangement of the ten tin atoms in the cluster core can be described as a distorted centaur polyhedron. Quantum chemical calculations suggest that there are 26 bonding electrons in the cluster core, which may be described as an arachno cluster in agreement with Wade’s rules. NMR and mass spectrometric investigations showed that 7 is highly reactive, which may be due to the open ligand shell. The easily available tin atoms in 7 thereby open the door to further subsequent reactions, in which 7 may act as a building block to larger cluster aggregates.
Palladium(0)‐Catalyzed Single and Double Isonitrile Insertion: A Facile Synthesis of Benzofurans, Indoles, and Isatins
Authors: Senadi Gopal Chandru , Hu Wan‐Ping , Boominathan Siva Senthil Kumar , Wang Jeh‐Jeng
Published: November 2014

A palladium(0)‐catalyzed cascade process consisting of isonitrile insertion and α‐Csp3H cross‐coupling can be achieved for the synthesis of benzofurans and indoles. The construction of isatins by a Pd‐catalyzed cascade reaction incorporating double isonitrile insertion, amination, and hydrolysis has also been achieved. The key features of this work include diverse heterocycle synthesis, phosphine‐ligand‐free reaction conditions, a one‐pot procedure, simple and commercially available starting materials, broad functional‐group compatibility, and moderate to good reaction yields.
Dissolution characteristics of calcium‐based alkaline industrial derived wastes
Authors: Zhao Jianli , Han Kuihua , Li Yingjie , Niu Shengli , Lu Chunmei
Published: November 2014

Accurately evaluating the rate at which calcium‐based alkaline industrial derived wastes (CAIDW) dissolve is very important in the design and development of CAIDW‐type wet flue gas desulfurization plants. The dissolution characteristics of alkaline slag (AS) and salt mud (SM) have been studied using pH stat method, and the effects of various parameters such as reaction temperature, sorbent particle size and solution acidity are studied to determine the dissolution kinetics of AS and SM. The production process of CAIDW presents high influence on its dissolution performance in acidic conditions. The kinetics analysis based on the modified shrinking core model (MSCM) indicates that AS dissolution kinetics, which is accompanied by surface reaction control, follows the film diffusion, and the activation energies of the two steps are 4.62 ± 0.8 and 36.34 ± 3.1 kJ/mol, respectively. Meanwhile, the SM dissolution obeys the surface reaction model with the activation energy of 9.69 ± 1.9 kJ/mol.
Ultrastructural evidence that motility changes caused by variations in ATP, Mg2+, and ADP correlate to conformational changes in reactivated bull sperm axonemes
Authors: Lesich Kathleen A. , de Pinho Tania G. , Dang Loan , Lindemann Charles B.
Published: November 2014

We report the results of an ultrastructural study of Triton X‐100‐extracted, Mg‐adenosine triphosphate (ATP)‐reactivated bull sperm. We utilized a rapid fixation method to look for differences in the flagellar apparatus that correlate to the state of motility of reactivated sperm models. In a companion article, we examined the motility characteristics induced in bull sperm models by varying the concentration ratio of ATP and Mg2+ and the stabilizing effect of adenosine diphosphate (ADP) on coordinated beating. Based on the results of that report, we selected four dissimilar states that appeared to represent extremes. One reactivation condition produces vigorous motility similar to live sperm, another produces large amplitude, low frequency beating while the remaining two conditions produce small amplitude vibrations of the flagellum with little coordinated beating. Morphometric analysis of transmission electron micrographs of sperm from these four treatment conditions revealed statistically significant differences between the samples in regard to axoneme diameter, inter‐microtubule doublet spacing, and outer dense fiber (ODF) spacing. Our results show that Mg2+ decreases the axoneme diameter and reduces interdoublet spacing, while ATP, uncomplexed with Mg2+, had the opposite effect. We also provide supporting evidence that this may be due to Mg2+ increasing, and ATP decreasing, the interdoublet adhesion of dynein. We also found that 4 mM ADP significantly increases the separation between the ODFs and the space between the ODFs and the central axoneme within the middle piece. We present a hypothetical explanation that is consistent with our results to explain how ATP, ADP, and Mg2+ act to regulate the beat cycle. © 2014 Wiley Periodicals, Inc.
The physiological role of ADP and Mg2+ in maintaining a stable beat cycle in bull sperm
Authors: Lindemann Charles B. , dePinho Tania G. , Lesich Kathleen A.
Published: November 2014

Sperm flagella derive their motive power from the motor protein dynein. In this study, we show that maintenance of the flagellar beat cycle in detergent‐extracted bull sperm models is highly dependent on the ratio of Mg2+ to adenosine triphosphate (ATP). An excess of either ATP un‐complexed with Mg2+, or an excess of Mg2+ without an equivalent concentration of ATP, results in the loss of beat amplitude and a reduced curvature development in the beat cycle. In addition, we find that adenosine diphosphate (ADP) can stabilize the beat cycle and permit rhythmic beating across a broader range of ATP and Mg2+ concentrations. We provide evidence that suggests that when ATP is un‐complexed with Mg2+, it disrupts the beat cycle by reducing dynein adhesion and thereby, reduces the transmission of dynein‐generated force between the doublets. Excess Mg2+ does not act by the same mechanism and induces a condition where the flagellum is more resistant to bending. This is consistent with the idea that high Mg2+ stabilizes rigor bridges, and ATP reduces the microtubule binding affinity of dynein. Our results may explain how intact sperm are able to sustain coordinated flagellar beating under a wide range of metabolic conditions, as intact sperm produce ADP in direct proportion to their consumption of ATP. © 2014 Wiley Periodicals, Inc.
Optimization of Diarylthiazole B‐Raf Inhibitors: Identification of a Compound Endowed with High Oral Antitumor Activity, Mitigated hERG Inhibition, and Low Paradoxical Effect
Authors: Pulici Maurizio , Traquandi Gabriella , Marchionni Chiara , Modugno Michele , Lupi Rosita , Amboldi Nadia , Casale Elena , Colombo Nicoletta , Corti Luca , Fasolini Marina , Gasparri Fabio , Pastori Wilma , Scolaro Alessandra , Donati Daniele , Felder Eduard , Galvani Arturo , Isacchi Antonella , Pesenti Enrico , Ciomei Marina
Published: November 2014

Aberrant activation of the mitogen‐activated protein kinase (MAPK)‐mediated pathway components, RAF‐MEK‐ERK, is frequently observed in human cancers and clearly contributes to oncogenesis. As part of a project aimed at finding inhibitors of B‐Raf, a key player in the MAPK cascade, we originally identified a thiazole derivative endowed with high potency and selectivity, optimal in vitro ADME properties, and good pharmacokinetic profiles in rodents, but that suffers from elevated hERG inhibitory activity. An optimization program was thus undertaken, focused mainly on the elaboration of the R1 and R2 groups of the scaffold. This effort ultimately led to N‐(4‐{2‐(1‐cyclopropylpiperidin‐4‐yl)‐4‐[3‐(2,5‐difluorobenzenesulfonylamino)‐2‐fluorophenyl]thiazol‐5‐yl}‐pyridin‐2‐yl)acetamide (20), which maintains favorable in vitro and in vivo properties, but lacks hERG liability. Besides exhibiting potent antiproliferative activity against only cell lines bearing B‐Raf V600E or V600D mutations, compound 20 also intriguingly shows a weaker “paradoxical” activation of MEK in non‐mutant B‐Raf cells than other known B‐Raf inhibitors. It also demonstrates very good efficacy in vivo against the A375 xenograft melanoma model (tumor volume inhibition >90 % at 10 mg kg−1); it is therefore a suitable candidate for preclinical development.
A Spray‐Based Technique for the Production of MnS Thin Films
Authors: Amirav Lilac , Lifshitz Efrat
Published: November 2014

A spray‐based technique, originally developed for the production of semiconductor nanocrystals, is utilized for the preparation of high‐quality nanocrystalline thin films, as demonstrated with manganese sulfide. The films are formed by the use of pneumatic‐assisted thermospray or pneumatic nebulizers. Our simple, low‐cost, and low‐temperature process results in a dense and phase‐pure grain structure. The concepts and benefits of this technique are described and discussed. The film characteristics show dependence on the experimental parameters, in particular the rate of solvent vaporization. Three alternative film formation mechanisms are suggested for cases with varied experimental conditions.
Computational Insights into the Charge Relaying Properties of β‐Turn Peptides in Protein Charge Transfers
Authors: Zhang Ru , Liu Jinxiang , Yang Hongfang , Wang Shoushan , Zhang Meng , Bu Yuxiang
Published: November 2014

Density functional theory calculations suggest that β‐turn peptide segments can act as a novel dual‐relay elements to facilitate long‐range charge hopping transport in proteins, with the N terminus relaying electron hopping transfer and the C terminus relaying hole hopping migration. The electron‐ or hole‐binding ability of such a β‐turn is subject to the conformations of oligopeptides and lengths of its linking strands. On the one hand, strand extension at the C‐terminal end of a β‐turn considerably enhances the electron‐binding of the β‐turn N terminus, due to its unique electropositivity in the macro‐dipole, but does not enhance hole‐forming of the β‐turn C terminus because of competition from other sites within the β‐strand. On the other hand, strand extension at the N terminal end of the β‐turn greatly enhances hole‐binding of the β‐turn C terminus, due to its distinct electronegativity in the macro‐dipole, but does not considerably enhance electron‐binding ability of the N terminus because of the shared responsibility of other sites in the β‐strand. Thus, in the β‐hairpin structures, electron‐ or hole‐binding abilities of both termini of the β‐turn motif degenerate compared with those of the two hook structures, due to the decreased macro‐dipole polarity caused by the extending the two terminal strands. In general, the high polarity of a macro‐dipole always plays a principal role in determining charge‐relay properties through modifying the components and energies of the highest occupied and lowest unoccupied molecular orbitals of the β‐turn motif, whereas local dipoles with low polarity only play a cooperative assisting role. Further exploration is needed to identify other factors that influence relay properties in these protein motifs.
Bimolecular Crystals with an Intercalated Structure Improve Poly(p‐phenylenevinylene)‐Based Organic Photovoltaic Cells
Authors: Lim Kyung‐Geun , Park Jun‐Mo , Mangold Hannah , Laquai Frédéric , Choi Tae‐Lim , Lee Tae‐Woo
Published: November 2014

The exciton dissociation, recombination, and charge transport of bulk heterojunction organic photovoltaic cells (OPVs) is influenced strongly by the nanomorphology of the blend, such as the grain size and the molecular packing. Although it is well known that polymers based on amorphous poly(p‐phenylenevinylene) (PPV) have a fundamental limit to their efficiency because of low carrier mobility, which leads to increased recombination and unbalanced charge extraction, herein, we demonstrate that the issue can be overcome by forming bimolecular crystals of an amorphous PPV‐based polymer:phenyl‐C61‐butyric acid methyl ester (PCBM) intercalated structure. We used amorphous poly(2,5‐dioctyloxy‐p‐phenylene vinylene‐alt‐2′,5′‐thienylene vinylene) (PPVTV), which has a simple chemical structure. A reasonably high power conversion efficiency (∼3.5 %) was obtained, although the material has an intrinsically amorphous structure and a relatively large band gap (2.0 eV). We demonstrate a correlation between a well‐ordered bimolecular crystal of PPVTV:PCBM and an improved hole mobility of a PPVTV:PCBM film compared to a pristine PPVTV film by using 2 D grazing incidence XRD and space‐charge‐limited current measurements. Furthermore, we show that the bimolecular crystal structure in high‐performance OPVs is related to an optimum molecular packing, which is influenced by the PPVTV:PCBM blending ratio, side‐chain length, and molecular weight of the PPVTV polymer. Improved charge transport in PPVTV:PCBM bimolecular crystals leads to a fast sweep out of charges and thus suppression of nongeminate recombination under the operating conditions.
Kinetic modeling of multi‐component crystallization of industrial‐grade oils and fats
Authors: Hjorth Jeppe L. , Miller Rasmus L. , Woodley John M. , Kiil Søren
Published: November 2014

Transient crystallization kinetics is investigated for complex, industrial‐grade vegetable oils consisting of more than ten triacylglycerols (TAG). The classical nucleation model has been used to describe primary nucleation, while secondary nucleation has been described by a semi‐empirical approach. Growth is modeled using a modified Burton‐Cabrera‐Frank (BCF) model. Surface tensions and growth constants have been determined using focused‐beam‐reflectance measurements (FBRM). The required adjustable parameters in the model have been fitted to overall crystallization curves obtained by solid‐fat content (SFC) measurements for a given oil at different cooling rates and degrees of dilution. The developed model can accommodate more polymorphs simultaneously and performs well with respect to predicting crystallization onset, rate of crystallization and final SFC value. It can also qualitatively describe how higher cooling rates lead to formation of more meta‐stable crystals and smaller mean‐crystal sizes.

Practical applications: The model provides a good starting point for developing more realistic, transient models for TAG crystallization with the ability to accommodate processing conditions and complex chemical compositions. Such a predictive model may provide a powerful tool to screen and optimize oil formulations in industrial processes and allow product developers to evaluate recrystallization events.

An advanced transient, mathematical model describing the course of crystallization in natural, multi‐component, multi‐phase vegetable oils and fats has been developed. The model is based on well described nucleation and growth kinetics and accommodates the presence of more polymorphic crystal forms. The result is an industry‐relevant model aiding understanding and predictability of oil and fat crystallization with respect to processing conditions and chemical compositions.
Iron/Caffeine as a Catalytic System for Microwave‐Promoted Benzamide Formation
Authors: Bantreil Xavier , Navals Pauline , Martinez Jean , Lamaty Frédéric
Published: November 2014

The amide bond is an essential unit in many drugs and polymers. The catalyzed oxidation of alcohols and amines is an effective method to form amides with limited undesired waste. Herein, we demonstrate the beneficial effect of microwave activation for this reaction. The benzamides were directly formed from alcohols and amine hydrochloride salts in short reaction times with yields up to 84 % and TOFs (turnover frequencies) up to 33.6 h–1. Among the examined transition metals, only nontoxic and inexpensive FeCl2·4H2O together with caffeine as a stabilizing ligand provided a uniquely efficient catalytic system for the transformation. Natural sources of caffeine were also evaluated under the amidation conditions.