bluuebunny/crossref_metadata_2025 huggingface dataset:
An energetic perspective on hydrological cycle changes in the Geoengineering Model Intercomparison Project
Authors: Kravitz Ben , Rasch Philip J. , Forster Piers M. , Andrews Timothy , Cole Jason N. S. , Irvine Peter J. , Ji Duoying , Kristjánsson Jón Egill , Moore John C. , Muri Helene , Niemeier Ulrike , Robock Alan , Singh Balwinder , Tilmes Simone , Watanabe Shingo , Yoon Jin‐Ho
Published: November 2013

Analysis of surface and atmospheric energy budget responses to CO2 and solar forcings can be used to reveal mechanisms of change in the hydrological cycle. We apply this energetic perspective to output from 11 fully coupled atmosphere‐ocean general circulation models simulating experiment G1 of the Geoengineering Model Intercomparison Project (GeoMIP), which achieves top‐of‐atmosphere energy balance between an abrupt quadrupling of CO2 from preindustrial levels (abrupt4xCO2) and uniform solar irradiance reduction. We divide the climate system response into a rapid adjustment, in which climate response is due to adjustment of the atmosphere and land surface on short time scales, and a feedback response, in which the climate response is predominantly due to feedback related to global mean temperature changes. Global mean temperature change is small in G1, so the feedback response is also small. G1 shows a smaller magnitude of land sensible heat flux rapid adjustment than in abrupt4xCO2 and a larger magnitude of latent heat flux adjustment, indicating a greater reduction of evaporation and less land temperature increase than abrupt4xCO2. The sum of surface flux changes in G1 is small, indicating little ocean heat uptake. Using an energetic perspective to assess precipitation changes, abrupt4xCO2 shows decreased mean evaporative moisture flux and increased moisture convergence, particularly over land. However, most changes in precipitation in G1 are in mean evaporative flux, suggesting that changes in mean circulation are small.
Elevation angle‐of‐arrival determination for a standard and a modified superDARN HF radar layout
Authors: McDonald Andrew J. , Whittington James , de Larquier Sebastien , Custovic Edhem , Kane Thomas A. , Devlin John C.
Published: November 2013

Calculations have been developed for the determination of elevation angle of arrival for a modified Super Dual Auroral Radar Network (SuperDARN) HF radar antenna layout consisting of dual auxiliary interferometer arrays: one behind and one in front of the main array. These calculations show that such a layout removes the 2π ambiguity or angle‐of‐arrival aliasing effect observed in existing SuperDARN HF radars. Ray tracing and simulation results are presented which show that there is significant potential for aliasing with existing SuperDARN radars and the standard interferometer algorithm under routine operating conditions.
Thermal and Structural Characterization Behavior of Electron Beam Irradiated Rubber/Clay Nanocomposites
Authors: Youssef Hussain , Ali Zakaria , El‐Nemr Khaled , Bekhit Mohamad
Published: November 2013

The effect of electron beam irradiation on the structure, thermal, and morphological properties of ethylene propylene diene monomer (EPDM)/clay and styrene butadiene rubber (SBR)/clay nanocomposites prepared by melt‐blending method has been investigated. The organomodified clay and irradiated rubber/clay samples were characterized using X‐ray diffraction (XRD), energy‐dispersive X‐ray (EDX), and thermogravimetric analysis (TGA). EDX and TGA data confirmed the modification of clay particles using cetyltrimethyl ammonium bromide (CTAB). The XRD patterns of the as‐prepared nanocomposites showed an indication of the presence of exfoliated clay layers at lower clay content whereas a phase‐separated (agglomeration) of organomodified clay layers was present at higher clay content. XRD data of unmodified clay/EPDM composites (EPDM–CCs) indicated that the rubber chains are not intercalated into the silicate galleries, that is, unmodified clay particles are simply incorporated into EPDM matrix in agglomerated states. EPDM–CNs and SBR–CNs nanocomposites show an exfoliated and/or a mixture of intercalated/exfoliated structures at lower (3–5 phr) and higher (10 phr) clay contents, respectively. TGA studies showed that the organomodified clay/rubber nanocomposites show a higher thermal stability in comparison with the unmodified clay/rubber composites. The improvement in the thermal properties is attributed to the organomodification of clay particles as well as the intercalation of rubber chains within silicate layers. In addition, EPDM–CNs nanocomposites exhibit a higher thermal stability than EPDM–CNs nanocomposites. © 2013 Wiley Periodicals, Inc. Adv Polym Technol 2014, 33, 21396; View this article online at wileyonlinelibrary.com. DOI 10.1002/adv.21396
Spectral and Thermal Behavior of Aromatic and Aliphatic Amines Cured Cardo Group Containing Multifunctional Epoxy Resin
Authors: Patel Jignesh P. , Parsania Parsotam H.
Published: November 2013

Multifunctional cardo epoxy resin (EBCF) was cured by using 3,3′‐diaminodiphenylsulfone, 4,4′‐diaminodiphenylsulfone, 4,4′‐diaminodiphenyl ether, 4,4′‐diaminodiphenylmethane, 1,4‐phenylenediamine, triethylamine, and diethylenetriamine as hardeners at 120°C for 15–60 min (gel time), and were post cured at 140°C for 80–90 min. Cured samples were found insoluble in common solvents. Cured and uncured EBCF are characterized by infrared spectral, differential scanning calorimetry, and thermogravimetric analysis techniques. Kinetic parameters, namely order of degradation, energy of activation, frequency factor, and entropy change were determined according to Anderson–Freeman method and interpreted in the light of nature of hardeners used. Thermal data of cured and uncured EBCF revealed complex degradation kinetics. © 2013 Wiley Periodicals, Inc. Adv Polym Technol 2014, 33, 21398; View this article online at wileyonlinelibrary.com. DOI 10.1002/adv.21398
Epoxy–Cyanate Ester Compositions as Matrixes for Tagging of Explosives
Authors: Večeřa Miroslav , Prokůpek Luboš , Machotová Jana , Šňupárek Jaromír , Husáková Lenka , Urbanová Iva , Akštein Zbyněk
Published: November 2013

The current study is primarily focused on the possibility to utilize blends of epoxy and cyanate ester resins as thermal and mechanical resistant polymeric matrixes for tagging of explosives. The effects of cyanate ester resin content and epoxy resin type on mechanical and thermal properties of resulting materials have been investigated with the aim to find the optimum composition for the preparation of tagging elements. It has been shown that a composite material consisting of a brominated epoxy–cyanate ester matrix, an ultraviolet light active pigment, and a coding system represented by various metal oxides in a given ratio, and iron powder bearing ferromagnetic properties could be successfully applied for tagging of explosives. A positive identification of a given explosive comprising the tagging elements after detonation has been demonstrated. © 2013 Wiley Periodicals, Inc. Adv Polym Technol 2014, 33, 21399; View this article online at wileyonlinelibrary.com. DOI 10.1002/adv.21399
Suitability of Screw Plasticization for Autosterile Injection Molding
Authors: Schönberger Markus , Hierl Franziska , Haerst Miriam , Wintermantel Erich
Published: November 2013

Single use medical products are subject to subsequent sterilization treatment following manufacturing processes, for example, injection molding, to obtain sterility. A new approach is developed to use the injection‐molding process to produce sterilized products without an additional sterilization procedure. To achieve the aim of an autosterile injection molding, it is necessary to evaluate the sterilization impact of screw plasticization regarding sterile polymer melts before entering the injection mold cavity. Within this study, a screw plasticization unit is fed with defined contaminated polymer granules. Geobacillus stearothermophilus spores are used as challenge organisms to determine the sterility grade of screw plasticization. The investigation includes method verification and the experimental testing of polyoxymethylene, polyethylene, and cyclo‐olefin copolymer melts at different melt temperatures of 200°C and 280°C. © 2013 Wiley Periodicals, Inc. Adv Polym Technol 2014, 33, 21403; View this article online at wileyonlinelibrary.com. DOI 10.1002/adv.21403
Automated screening for myelodysplastic syndromes through analysis of complete blood count and cell population data parameters
Authors: Raess Philipp W. , van de Geijn Gert‐Jan M. , Njo Tjin L. , Klop Boudewijn , Sukhachev Dmitry , Wertheim Gerald , McAleer Tom , Master Stephen R. , Bagg Adam
Published: November 2013

The diagnosis of myelodysplastic syndromes (MDS) requires a high clinical index of suspicion to prompt bone marrow studies as well as subjective assessment of dysplastic morphology. We sought to determine if data collected by automated hematology analyzers during complete blood count (CBC) analysis might help to identify MDS in a routine clinical setting. We collected CBC parameters (including those for research use only and cell population data) and demographic information in a large (>5,000), unselected sequential cohort of outpatients. The cohort was divided into independent training and test groups to develop and validate a random forest classifier that identifies MDS. The classifier effectively identified MDS and had a receiver operating characteristic area under the curve (AUC) of 0.942. Platelet distribution width and the standard deviation of red blood cell distribution width were the most discriminating variables within the classifier. Additionally, a similar classifier was validated with an additional, independent set of >200 patients from a second institution with an AUC of 0.93. This retrospective study demonstrates the feasibility of identifying MDS in an unselected outpatient population using data routinely collected during CBC analysis with a classifier that has been validated using two independent data sets from different institutions. Am. J. Hematol. 89:369–374, 2014. © 2013 Wiley Periodicals, Inc.
Following Solid‐Acid‐Catalyzed Reactions by MAS NMR Spectroscopy in Liquid Phase—Zeolite‐Catalyzed Conversion of Cyclohexanol in Water
Authors: Vjunov Aleksei , Hu Mary Y. , Feng Ju , Camaioni Donald M. , Mei Donghai , Hu Jian Z. , Zhao Chen , Lercher Johannes A.
Published: November 2013

A microautoclave magic angle spinning NMR rotor is developed enabling in situ monitoring of solid–liquid–gas reactions at high temperatures and pressures. It is used in a kinetic and mechanistic study of the reactions of cyclohexanol on zeolite HBEA in 130 °C water. The 13C spectra show that dehydration of 1‐13C‐cyclohexanol occurs with significant migration of the hydroxy group in cyclohexanol and the double bond in cyclohexene with respect to the 13C label. A simplified kinetic model shows the E1‐type elimination fully accounts for the initial rates of 1‐13C‐cyclohexanol disappearance and the appearance of the differently labeled products, thus suggesting that the cyclohexyl cation undergoes a 1,2‐hydride shift competitive with rehydration and deprotonation. Concurrent with the dehydration, trace amounts of dicyclohexyl ether are observed, and in approaching equilibrium, a secondary product, cyclohexyl‐1‐cyclohexene is formed. Compared to phosphoric acid, HBEA is shown to be a more active catalyst exhibiting a dehydration rate that is 100‐fold faster per proton.
Synthesis of a DNA Promoter Segment Containing All Four Epigenetic Nucleosides: 5‐Methyl‐, 5‐Hydroxymethyl‐, 5‐Formyl‐, and 5‐Carboxy‐2′‐Deoxycytidine
Authors: Schröder Arne S. , Steinbacher Jessica , Steigenberger Barbara , Gnerlich Felix A. , Schiesser Stefan , Pfaffeneder Toni , Carell Thomas
Published: November 2013

A 5‐formyl‐2′‐deoxycytidine (fdC) phosphoramidite building block that enables the synthesis of fdC‐containing DNA with excellent purity and yield has been developed. In combination with phosphoramidites for 5‐methyl‐dC, 5‐hydroxymethyl‐dC, and carboxy‐dC, it was possible to prepare a segment of the OCT‐4 promoter that contains all four epigenetic bases. Because of the enormous interest in these new epigenetic bases, the ability to insert all four of them into DNA should be of great value for the scientific community.
High‐Yield Electrochemical Production of Formaldehyde from CO2 and Seawater
Authors: Nakata Kazuya , Ozaki Takuya , Terashima Chiaki , Fujishima Akira , Einaga Yasuaki
Published: November 2013

The catalytic, electrocatalytic, or photocatalytic conversion of CO2 into useful chemicals in high yield for industrial applications has so far proven difficult. Herein, we present our work on the electrochemical reduction of CO2 in seawater using a boron‐doped diamond (BDD) electrode under ambient conditions to produce formaldehyde. This method overcomes the usual limitation of the low yield of higher‐order products, and also reduces the generation of H2. In comparison with other electrode materials, BDD electrodes have a wide potential window and high electrochemical stability, and, moreover, exhibit very high Faradaic efficiency (74 %) for the production of formaldehyde, using either methanol, aqueous NaCl, or seawater as the electrolyte. The high Faradaic efficiency is attributed to the sp3‐bonded carbon of the BDD. Our results have wide ranging implications for the efficient and cost‐effective conversion of CO2.
Ligand‐free CuTC‐catalyzed N‐arylation of amides, anilines and 4‐aminoantipyrine: synthesis of N‐arylacrylamides, 4‐amido‐N‐phenylbenzamides and 4‐amino(N‐phenyl)antipyrenes
Authors: Quan Zheng‐Jun , Xia Hai‐Dong , Zhang Zhang , Da Yu‐Xia , Wang Xi‐Cun
Published: November 2013

N‐Arylation of amides and anilines with aryl iodides was efficiently catalyzed by copper thiophenecarboxylate under ligand‐free conditions with good to excellent yields. A variety of substituted aryl iodides, amides, anilines and 4‐aminoantipyrine were found to be applicable to the simple catalytic system. Furthermore, some practical, unique secondary amides, such as N‐arylacrylamides and 4‐amido‐N‐phenylbenzamides, and 4‐amino(N‐phenyl)antipyrenes, which are difficult to obtain by the classical methods, were prepared. Copyright © 2013 John Wiley & Sons, Ltd.
Synthesis, characterization and catalytic activity of new aminomethyldiphosphine–Pd(II) complexes for Suzuki cross‐coupling reaction
Authors: Keleş Mustafa , Y𝚤lmaz Mustafa Kemal
Published: November 2013

A new range of CF3‐substituted aminomethyldiphosphine (P―C―N) ligands ((C6H5)2PCH2)2NR (R = ―C6H4(2‐CF3) (1), ―C6H4(3‐CF3) (1b) has been synthesized from 2‐(trifluoromethyl)aniline and 3‐(trifluoromethyl)aniline with diphenylphosphine. The aminomethyldiphosphine ligands were reacted with Pd(cod)Cl2 to give corresponding metal complexes, PdLCl2 (2a, 2b). The aminomethyldiphosphine–palladium compounds were characterized by utilizing several methods including NMR (1H, 13C, 31P) and elemental analysis. These compounds were used as catalysts in Suzuki cross‐coupling reaction of aryl chlorides and bromides. The effect of base was also investigated in this current project. CF3‐substituted aminomethyldiphosphine–palladium complexes were found to be efficient catalysts in Suzuki cross‐coupling reaction of activated and deactivated aryl boronic acids. Copyright © 2013 John Wiley & Sons, Ltd.
Biosorptive distillations to purify isopropanol: improvements over the current process in terms of energy consumption and exergy
Authors: Sun Jinsheng , Wang Wenping , Wang Pei , Luo Xubo , Shi Ming , Gao Hong , Ren Xiaojing
Published: November 2013

The removal of water from certain organic solvents via ordinary distillation requires several equilibrium stages if the organics are sufficiently concentrated, because the equilibrium curve for isopropanol–water is near the operating line, whereas acetone–water mixtures form a tangent pinch. In contrast, biosorption is only competitive when small quantities of adsorbate are removed. To overcome the drawbacks of both ordinary distillation and biosorption, a biosorptive distillation process was suggested for purifying 99.7 wt% isopropanol from a feed containing small amounts of water. Adsorption/regeneration experiments were conducted to investigate the breakthrough time and reusability of the adsorbent. The Ritchie equation, which fits the adsorption experimental data well, was embedded into the modified process simulation. Most of the water was removed via the adsorption part, which reduced its influence on the distillation. Compared to current commercial process, biosorptive distillation leads to a 25.4% reduction in the total energy and an overall exergy loss of 28.9% relative to absorbent regeneration. Furthermore, less than 1 year is required to recover the additional investment of the modified process. The proposed process can be both environmentally friendly and energy efficient. © 2013 Curtin University of Technology and John Wiley & Sons, Ltd.
Modified atmosphere packaging bags of peanuts with effect of inhibition of aflatoxin growth
Authors: Wang Hong , Jin Xiangyu , Wu Haibo
Published: November 2013

In this article, packaging bags composited with selective barrier film and moisture absorbent nonwoven fabrics were prepared to design a kind of functional bags, which can inhibit the growth of aflatoxin of peanuts. The influences of the super‐absorbent fiber (SAF) and jute fiber on the internal relative humidity (RH) were investigated. It is found that jute nonwoven/selective barrier film composite bag can prevent the growth of aflatoxin B1 of peanuts under the environment studied in this article because peanuts with higher moisture content can reduce O2 content inside the bag by the aerobic respiration, achieving the modified atmosphere packaging (MAP) effect. In addition, a low RH micro‐environment can be achieved by using SAF as moisture absorbent. It is promising to design a packaging bag with the effect of inhibition of the growth of aflatoxin of peanuts, by selecting proper moisture absorbent and selective barrier film of the composite bag. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40190.
Viscosity and refractive index tailored methacrylate‐based polymers
Authors: Hanemann Thomas , Honnef Kirsten
Published: November 2013

With respect to the realization of new polymer optical devices with enhanced functionality there is a need for the development of new highly transparent polymer based systems with adjustable viscosity prior to curing and tailored refractive index as well as high continuous operation temperature after solidification. The use of phenanthrene as dopant enabled the increase of the refractive index in polymethylmethacrylate from 1.49 up to 1.55(at 589 nm). A copolymerization of a dimethacrylate with the initial methylmethacrylate/polymethylmethacrylate reactive resin suppressed the dopant‐related plasticizing effect. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40194.
Collaborative information seeking
Authors: Shah Chirag
Published: November 2013

The notions that information seeking is not always a solitary activity and that people working in collaboration for information intensive tasks should be studied and supported have become more prevalent in recent years. Several new research questions, methodologies, and systems have emerged around these notions that may prove to be useful beyond the field of collaborative information seeking (CIS), with relevance to the broader area of information seeking and behavior. This article provides an overview of such key research work from a variety of domains, including library and information science, computer‐supported cooperative work, human‐computer interaction, and information retrieval. It starts with explanations of collaboration and how CIS fits in different contexts, emphasizing the interactive, intentional, and mutually beneficial nature of CIS activities. Relations to similar and related fields such as collaborative information retrieval, collaborative information behavior, and collaborative filtering are also clarified. Next, the article presents a synthesis of various frameworks and models that exist in the field today, along with a new synthesis of 12 different dimensions of group activities. A discussion on issues and approaches relating to evaluating various parameters in CIS follows. Finally, a list of known issues and challenges is presented to provide an overview of research opportunities in this field.
A knowledge‐based approach for polarity classification in Twitter
Authors: Montejo‐Ráez Arturo , Martínez‐Cámara Eugenio , Martín‐Valdivia M. Teresa , Ureña‐López L. Alfonso
Published: November 2013

Until now, most of the methods published for polarity classification in Twitter have used a supervised approach. The differences between them are only the features selected and the method used for weighting them. In this article, we present an unsupervised method for polarity classification in Twitter. The method is based on the expansion of the concepts expressed in the tweets through the application of PageRank to WordNet. In addition, we integrate SentiWordNet to compute the final value of polarity. The synsets values are weighted with the PageRank scores obtained in the previous random walk process over WordNet. The results obtained show that disambiguation and expansion are good strategies for improving overall performance.
Managing scientific data as public assets: Data sharing practices and policies among full‐time government employees
Authors: Douglass Kimberly , Allard Suzie , Tenopir Carol , Wu Lei , Frame Mike
Published: November 2013

This paper examines how scientists working in government agencies in the U.S. are reacting to the “ethos of sharing” government‐generated data. For scientists to leverage the value of existing government data sets, critical data sets must be identified and made as widely available as possible. However, government data sets can only be leveraged when policy makers first assess the value of data, in much the same way they decide the value of grants for research outside government. We argue that legislators should also remove structural barriers to interoperability by funding technical infrastructure according to issue clusters rather than administrative programs. As developers attempt to make government data more accessible through portals, they should consider a range of other nontechnical constraints attached to the data. We find that agencies react to the large number of constraints by mostly posting their data on their own websites only rather than in data portals that can facilitate sharing. Despite the nontechnical constraints, we find that scientists working in government agencies exercise some autonomy in data decisions, such as data documentation, which determine whether or not the data can be widely shared. Fortunately, scientists indicate a willingness to share the data they collect or maintain. However, we argue further that a complete measure of access should also consider the normative decisions to collect (or not) particular data.
Preparation of Li4Ti5O12 Yolk–Shell Powders by Spray Pyrolysis and their Electrochemical Properties
Authors: Yang Kwang Min , Ko You Na , Yun Jung‐Yeul , Kang Yun Chan
Published: November 2013

We have reported for the first time the preparation of yolk–shell‐structured Li4Ti5O12 powders for use as anode materials in lithium‐ion batteries. One Li4Ti5O12 yolk–shell‐particle powder is directly formed from each droplet containing lithium, titanium, and carbon components inside the hot wall reactor maintained at 900 °C. The precursor Li4Ti5O12 yolk–shell‐particle powders, which are directly prepared by spray pyrolysis, have initial discharge and charge capacities of 155 and 122 mA h g−1, respectively, at a current density of 175 mA g−1. Post‐treatment of the yolk–shell‐particle powders at temperatures of 700 and 800 °C improves the initial discharge and charge capacities. The initial discharge capacities of the Li4Ti5O12 powders with a yolk–shell structure and a dense structure post‐treated at 800 °C are 189 and 168 mA h g−1, respectively. After 100 cycles, the corresponding capacities are 172 and 152 mA h g−1, respectively (retentions of 91 and 90 %).
Making connections: Insulators organize eukaryotic chromosomes into independent cis‐regulatory networks
Authors: Chetverina Darya , Aoki Tsutomu , Erokhin Maksim , Georgiev Pavel , Schedl Paul
Published: November 2013

Insulators play a central role in subdividing the chromosome into a series of discrete topologically independent domains and in ensuring that enhancers and silencers contact their appropriate target genes. In this review we first discuss the general characteristics of insulator elements and their associated protein factors. A growing collection of insulator proteins have been identified including a family of proteins whose expression is developmentally regulated. We next consider several unexpected discoveries that require us to completely rethink how insulators function (and how they can best be assayed). These discoveries also require a reevaluation of how insulators might restrict or orchestrate (by preventing or promoting) interactions between regulatory elements and their target genes. We conclude by connecting these new insights into the mechanisms of insulator action to dynamic changes in the three‐dimensional topology of the chromatin fiber and the generation of specific patterns of gene activity during development and differentiation.
Systematic review and meta-analysis of percutaneous subclavian vein puncture versus surgical venous cutdown for the insertion of a totally implantable venous access device
Authors: Orci L A , Meier R P H , Morel P , Staszewicz W , Toso C
Published: November 2013

Background

Totally implantable venous access devices (TIVADs) are commonly used in patients with cancer. Although several methods of implantation have been described, there is not enough evidence to support the use of a specific technique on a daily basis. The objective of this study was systematically to assess the literature comparing percutaneous subclavian vein puncture with surgical venous cutdown.

Methods

MEDLINE, Embase and the Cochrane Central Register of Controlled Trials were searched by two independent authors. No time limits were applied. A systematic review and meta-analysis was carried out according to the recommendations of the Cochrane Collaboration, including randomized clinical trials comparing primary percutaneous subclavian vein puncture with surgical venous cutdown.

Results

Six trials were included, with 772 patients overall. The primary implantation failure rate was significantly lower for the percutaneous approach compared with surgical cutdown (odds ratio (OR) 0·26, 95 per cent confidence interval (c.i.) 0·07 to 0·94; P = 0·039). There was no evidence supporting a significant difference in terms of risk of pneumothorax, haematoma, venous thrombosis, infectious events or catheter migration. After taking between-study heterogeneity into account by using a random-effects model, procedure duration was not significantly longer for surgical cutdown: weighted mean difference +4 (95 per cent c.i. –12 to 20) min (P = 0·625).

Conclusion

Percutaneous subclavian vein puncture is associated with a higher TIVAD implantation success rate and a procedure duration similar to that of surgical cutdown. Pneumothorax develops exclusively after percutaneous puncture and requires special attention from clinicians dealing with TIVAD insertion.
The Electrodeposition of Silver from Supercritical Carbon Dioxide/Acetonitrile
Authors: Bartlett Philip N. , Perdjon‐Abel Magdalena , Cook David , Reid Gillian , Levason William , Cheng Fei , Zhang Wenjian , George Michael W. , Ke Jie , Beanland Richard , Sloan Jeremy
Published: November 2013

Cyclic voltammetry of silver coordination complexes in acetonitrile and in a single‐phase supercritical carbon dioxide/acetonitrile (scCO2/CH3CN) system is reported. Five silver precursors are investigated: (1,5‐cyclooctadiene)(hexafluoroacetylacetonato) silver(I) [Ag(hfac)(COD)], (hexafluoroacetylacetonato)(triphenylphosphine) silver(I) [Ag(hfac)(PPh3)], (perfluorooctanoato)bis(triphenylphosphine) silver(I) [Ag(CF3(CF2)6CO2)(PPh3)2], tetrakis(triphenylphosphine) silver(I) tetrafluoroborate [Ag(PPh3)4][BF4] and tetrakis(acetonitrile) silver(I) tetrafluoroborate [Ag(CH3CN)4][BF4]. Of these, [Ag(CH3CN)4][BF4] is found to be the most suitable for electrodeposition of silver from scCO2/CH3CN.
Hierarchically Ordered Tubular Titanium Dioxide Electrodes: Preparation, Electrochemical Characterization, and Application as a Bifunctional Catalyst
Authors: Deva Kumar E. T. , Ganesh V.
Published: November 2013

In this work, hierarchically ordered tubular TiO2 electrodes are prepared by a simple electrochemical anodization process. Their potential application as an efficient bifunctional electrocatalyst for oxygen and hydrogen evolution reactions in neutral medium is demonstrated. The dimensions of porous tubular structures can be tuned by altering the composition of electrolyte, time of anodization, and applied voltage. Surface morphological analysis and structural characterizations are carried out by means of SEM, TEM, AFM, and XRD studies. The precise band‐gap value of these electrodes is determined from diffuse reflectance UV/Vis spectroscopic studies by using the Kubelka–Munk function. These studies also reveal that the wavelength of absorption of light by nanotubular TiO2 electrodes can be extended without the addition of any dopants or sensitizers by simply tuning the parameters of the anodization process. SEM, TEM, and AFM analyses show the formation of homogeneous, porous nanotubular structures with uniform dimensions for anodized titanium plates. XRD studies confirm the formation of the anatase phase of TiO2 when the anodized samples are post‐heated at a temperature of about 450 °C and above.
Microgalvanic Corrosion of the Magnesium‐Aluminum System – Detailed Electrochemical Insights by FEM Simulations
Authors: Höche Daniel , Isakovic Jonas
Published: November 2013

Die Untersuchungen zeigen, wie galvanische Korrosion am Modellsystem Mg‐Al auf mikroskopischer Ebene abläuft. Die benötigten Randbedingungen werden zum einen durch die Oberflächenmorphologie der binären Magnesiumslegierung (Mg‐9Al) und zum anderen durch die elektrochemische Kinetik der jeweiligen metallischen Phase bestimmt. Zur Modellierung werden Querschliffe in eine Modellgeometrie überführt. Die Simulationen zeigen, wie sich u. a. die Leitfähigkeit des Elektrolyten auf den Korrosionsprozess auswirken. Die sich bietenden Möglichkeiten können zukünftig helfen, Legierungen am PC maßzuschneidern und liefern Impulse für simulationsbasierte Korrosionsschutzkonzepte.
A statistical test for mixture detection with application to component identification in multidimensional biomolecular NMR studies
Authors: Serban Nicoleta , Li Pengfei
Published: November 2013

We introduce a statistical hypothesis test for detecting mixtures in a nonlinear regression model with mean regression function defined by a weighted sum of two multidimensional unimodal functions, where each unimodal function in the summation representing acomponent. Two regression components are mixed when the distance between their centres is small or the proportion of their contribution to the mean regression function is close to zero or one. Two challenges in model estimation under the null hypothesis of one regression component are that the proportion parameter describing the weighed contribution of each component lies on the boundary of the parameter space and that the model parameters are nonidentifiable. Therefore, the parameter estimators derived from standard nonlinear estimation approaches are inconsistent and unstable. To overcome these challenges, we study a penalized regression test statistic with a relatively simple quadratic approximation which can be used to simulate the quantiles of the test statistic under the null hypothesis. One leading application of the mixture testing procedure is the detection of mixed or overlapped components in multidimensional data generated from nuclear magnetic resonance (NMR) experiments for protein structure determination. It is important to de‐mix the components since each regression component provides specific information about the structure of the protein. In certain cases, the lack of a small number of essential components can lead to a significant deviation in the predicted structure.The Canadian Journal of Statistics42: 36–60; 2014 © 2013 Statistical Society of Canada
Transmission behavior improvement of electro‐optic modulators for integrated photonic systems in the present communication technology
Authors: Rashed Ahmed Nabih Zaki , Saad Abd El‐Fattah A.
Published: November 2013

This paper has presented the transmission performance evaluation of different electro‐optic modulators (EOM) for ultra high switching speed operations and applications. As well as the optimization design parameters for different EOMs have been investigated, where the effective refractive index plays an essential role in the evaluation of the bandwidth structure. The effects of the operating parameters on the switching, modulating voltage, device performance index, and optical bandwidth are also investigated for different material‐based EOMs, where the transmission bit rate is evaluated by using non‐return‐to‐zero coding transmission technique. As well as lithium niobate, gallium arsenide, and poly methyl metha acrylate polymer EOMs have been developed for extensive use in high speed and high transmission performance optical fiber transmission systems. Copyright © 2013 John Wiley & Sons, Ltd.
Underestimating the frequency, strength and cost of antipredator responses with data fromGPScollars: an example with wolves and elk
Authors: Creel Scott , Winnie John A. , Christianson David
Published: November 2013

Field studies that rely on fixes fromGPS‐collared predators to identify encounters with prey will often underestimate the frequency and strength of antipredator responses. These underestimation biases have several mechanistic causes. (1)Step bias: The distance between successiveGPSfixes can be large, and encounters that occur during these intervals go undetected. This bias will generally be strongest for cursorial hunters that can rapidly cover large distances (e.g., wolves and African wild dogs) and when the interval betweenGPSfixes is long relative to the duration of a hunt. Step bias is amplified as the path travelled between successiveGPSfixes deviates from a straight line. (2)Scatter bias: Only a small fraction of the predators in a population typically carryGPScollars, and prey encounters with uncollared predators go undetected unless a collared group‐mate is present. This bias will generally be stronger for fission–fusion hunters (e.g., spotted hyenas, wolves, and lions) than for highly cohesive hunters (e.g., African wild dogs), particularly when their group sizes are large. Step bias and scatter bias both cause underestimation of the frequency of antipredator responses. (3)Strength bias: Observations of prey in the absence ofGPSfix from a collared predator will generally include a mixture of cases in which predators were truly absent and cases in which predators were present but not detected, which causes underestimation of the strength of antipredator responses. We quantified these biases with data from wolves and African wild dogs and found that fixes fromGPScollars at 3‐h intervals underestimated the frequency and strength of antipredator responses by a factor >10. We reexamined the results of a recent study of the nonconsumptive effects of wolves on elk in light of these results and confirmed that predation risk has strong effects on elk dynamics by reducing the pregnancy rate.
IL‐13Rα1 is a surface marker for M2 macrophages influencing their differentiation and function
Authors: Dhakal Mermagya , Hardaway John C. , Guloglu Fatma Betul , Miller Mindy M. , Hoeman Christine M. , Zaghouani Adam A. , Wan Xiaoxiao , Rowland Linda M. , Cascio Jason A. , Sherman Michael P. , Zaghouani Habib
Published: November 2013

In this study, we examined the role IL‐13 receptor alpha 1 (IL‐13Rα1) plays in macrophage differentiation and function. The findings indicate that IL‐13Rα1 is expressed on the M2 but not on the M1 subset of macrophages and specifically heterodimerizes with the IL‐4Rα chain to form a type II receptor, which controls the differentiation and function of these cells. Indeed, BM cells from IL‐13Rα1+/+ and IL‐13Rα1−/− mice yield equivalent numbers of macrophages when cultured under M2 polarizing conditions. However, IL‐13Rα1−/− BM cells yield a much higher number of macrophages than IL‐13Rα1+/+ BM cells when the differentiation is carried out under M1‐polarizing conditions. Further analyses indicated that macrophages that express IL‐13Rα1 also display surface markers associated with an M2 phenotype. In addition, the IL‐13Rα1+ macrophages were highly efficient in phagocytizing zymosan bioparticles both in vitro and in vivo, and supported differentiation of naïve T cells to a Th2 phenotype. Finally, when stimulated by IL‐13, a cytokine that uses the heteroreceptor, the cells were able to phosphorylate STAT6 efficiently. These previously unrecognized findings indicate that IL‐13Rα1 serves as a marker for M2 macrophages and the resulting heteroreceptor influences both their differentiation and function.
Crystal Structure and Microwave Dielectric Properties of an Ultralow‐Temperature‐Fired (AgBi)0.5WO4 Ceramic
Authors: Zhou Di , Pang Li‐Xia , Xie Hui‐Dong , Guo Jing , He Bin , Qi Ze‐Ming , Shao Tao , Yao Xi , Randall Clive A.
Published: November 2013

A new microwave dielectric (AgBi)0.5WO4 ceramic with an ultralow firing temperature was prepared by the solid‐state reaction method. (AgBi)0.5WO4 can be obtained as a dense single‐phase bulk material with a calcination temperature of 500 °C and sintering temperatures of ca. 580 °C. The material has a microwave relative permittivity of ca. 35.9, a Qf value of ca. 13000 GHz, and a negative temperature coefficient of –69 ppm/°C at 7.5 GHz. The crystal structure of (AgBi)0.5WO4 was determined by a combination of X‐ray and transmission electron microscopy (TEM) diffraction analysis. The compound crystallizes in the monoclinic C12/m1 (no. 12) space group with the lattice parameters a = 10.1330(8) Å, b = 11.0013(0) Å, c = 7.2756(4) Å, and β = 127.712(3)°. From an X‐ray diffraction analysis, the (Ag0.5Bi0.5)WO4 ceramic reacts with silver after heat treatment at 560 °C to form new compounds, namely, Bi2WO6 and Ag2WO4. However, the (AgBi)0.5WO4 ceramic is chemically compatible with aluminum powder at 600 °C as an alternative cofired electrode material. All the results suggest that (AgBi)0.5WO4 ceramic is a promising new candidate material for ultralow‐temperature cofired ceramic (ULTCC) technology.
Diastereomerically Pure Heterodi‐ and Heterotetrametallic (Pd and Pt) Compounds: A Study of the Effect Induced by the Binding Mode of a Ferrocene‐Containing Ligand on Their Electrochemical Properties
Authors: Talancón Daniel , López Concepción , Font‐Bardía Mercè , Calvet Teresa , Roubeau Olivier
Published: November 2013

The reaction of (1S,2R)‐[(η5‐C5H5)Fe{(η5‐C5H4)‐CH=N‐CH(Me)‐CH(OH)(C6H5)}] (1) with Na2[PdCl4] in the presence of Na(OAc)·3H2O produced three diastereomerically pure tetrametallic cyclopalladated complexes (6bI–6bIII). In two of them (6bI and 6bII), the imine 1 adopts the [C(sp2,ferrocene),N]– mode of binding, but they differ in the planar chirality of the 1,2‐ferrocenyl unit (Sp in 6bI and Rp in 6bII), whereas ligand 1 in 6bIII acts as a [C(sp2,phenyl),N]– group. Treatment of 6bI–6bIII with PPh3 gave [Pd{κ2‐C,N{(η5‐C5H3)‐CH=N‐CH(Me)‐CH(OH)(C6H5)}Fe(η5‐C5H5)}Cl(PPh3)] (7bI, 7bII) and [Pd{κ2‐C,N{(C6H4)‐CH(OH)‐CH(Me)‐N=CH‐(η5‐C5H4)}Fe(η5‐C5H5)}Cl(PPh3)] (7bIII). The PtII compounds [Pt{κ2‐C,N{(η5‐C5H3)‐CH=NCH(Me)CH(OH)(C6H5)}Fe(η5‐C5H5)}Cl(PPh3)] [(Sp,1S,2R) and (Rp,1S,2R) diastereomers, 7aI and 7aII, respectively)] have also been prepared. The results of electrochemical studies of 6bI–6bIII, 7bI–7bIII, 7aI, 7aII and related PtII complexes with 1 acting as an (N) or (N,O)– ligand are also reported. Comparison of the results provides conclusive evidence for the relative influence of the mode of binding of the ligand, the nature of the MII atom, the type of metallated atom C(sp2,phenyl or ferrocenyl), the ancillary ligands and their relative disposition on the electrochemical properties of this type of compound.
Chemoenzymatic Asymmetric Total Synthesis of Nonanolide (Z)‐Cytospolides D, E and Their Stereoisomers
Authors: Rej Rohan Kalyan , Nanda Samik
Published: November 2013

Chemoenzymatic asymmetric total synthesis of the (Z)‐isomer of the naturally occurring decanolide cytospolides D, E and six stereoisomers is reported. The main highlight of the synthetic venture involves ring‐closing metathesis (RCM) reaction of a suitably functionalized ester compound, which was assembled by the Yamaguchi coupling of the required acid and alcohol fragments. The alcohol fragment was accessed by two alternative chemoenzymatic processes, one being hydroxynitrile lyase mediated hydrocyanation, whereas lipase‐catalyzed transesterification was the key sep in the second route. The acid fragment was constructed by an enantioselective enzymatic desymmetrization (EED) of prochiral 2‐methyl‐1,3‐propanediol and Corey–Bakshi–Shibata (CBS) mediated stereoselective carbonyl reduction.
Oxidation of Alcohols to Aldehydes or Ketones with 1‐Acetoxy‐1,2‐benziodoxole‐3(1H)‐one Derivatives
Authors: Iinuma Masataka , Moriyama Katsuhiko , Togo Hideo
Published: November 2013

Various benzylic and aliphatic alcohols were smoothly oxidized to the corresponding aromatic aldehydes and ketones as well as aliphatic ketones by treatment with 1‐acetoxy‐5‐nitro‐1,2‐benziodoxole‐3(1H)‐one (ANBX), 1‐acetoxy‐5‐bromo‐1,2‐benziodoxole‐3(1H)‐one (ABBX), 1‐acetoxy‐5‐chloro‐1,2‐benziodoxole‐3(1H)‐one (ACBX), and 1‐acetoxy‐5‐fluoro‐1,2‐benziodoxole‐3(1H)‐one (AFBX). These new trivalent iodine compounds were prepared from 5‐substituted 2‐iodobenzoic acids and meta‐chloroperoxybenzoic acid (m‐CPBA). ANBX and ABBX were the most effective reagents for this oxidation of alcohols, and this present reaction is very attractive because of the ease of product isolation and the reusability of the reagents.
Solar powered charge stations for electric vehicles
Authors: Goldin Erica , Erickson Larry , Natarajan Bala , Brase Gary , Pahwa Anil
Published: November 2013

Every hour, the sun emits more energy onto the Earth's surface than our entire world population uses in one year (Green Fuel, 2013,http://www.greenfuelsolar.com/solar‐fact‐or‐fiction/) Solar power provides us with the possibility of a cleaner and more renewable future. Global climate change as a result of greenhouse gases and the effects of low air quality caused by pollutants have become very substantial issues in our world today. The costs associated with greenhouse gas and air pollutant emissions, and the effect they have on human lives and human health, are major and growing concerns. The development and installation of solar powered charging stations will reduce the amount of greenhouse gases emitted into the atmosphere, future costs associated with climate change, and health issues. Thus, there is environmental, social, and economic value associated with the installation of solar powered charge stations. Solar powered charging stations have the potential of significantly reducing air pollutants and improving urban air quality. The electrification of transportation and the use of solar powered charging stations as an electricity source will improve people's quality of life. © 2013 American Institute of Chemical Engineers Environ Prog, 33: 1298–1308, 2014
Psychological Barriers and Option Pricing
Authors: Jang Bong‐Gyu , Kim Changki , Kim Kyeong Tae , Lee Seungkyu , Shin Dong‐Hoon
Published: November 2013

Psychological barriers are prevalent among various asset classes, and it is important to consider their impact on the prices of derivative securities. This paper demonstrates the potential existence of such barriers on the S&P 500 Index and examines their impact on this index's rate of return and volatility. It focuses on deriving analytic European option prices under the assumption that the dynamics of stock prices follow a threshold model; this paper also evaluates this model's empirical performance relative to the Black–Scholes and constant elasticity of variance (CEV) models. The in‐sample calibration result of the threshold model is found to be superior. Furthermore, it is found that the model provides an efficient hedging method in terms of dollar‐value hedging errors. © 2013 Wiley Periodicals, Inc. Jrl Fut Mark 35:52–74, 2015
Establishment of Mice With Inheritable Susceptibility to Productive Hepatitis C Virus infection
Authors: Uprichard Susan L.
Published: November 2013

More than 130 million people worldwide chronically infected with hepatitis C virus (HCV) are at risk of developing severe liver disease. Antiviral treatments are only partially effective against HCV infection, and a vaccine is not available. Development of more efficient therapies has been hampered by the lack of a small animal model. Building on the observation that CD81 and occludin (OCLN) comprise the minimal set of human factors required to render mouse cells permissive to HCV entry, we previously showed that transient expression of these two human genes is sufficient to allow viral uptake into fully immunocompetent inbred mice. Here we demonstrate that transgenic mice stably expressing human CD81 and OCLN also support HCV entry, but innate and adaptive immune responses restrict HCV infection in vivo. Blunting antiviral immunity in genetically humanized mice infected with HCV results in measurable viraemia over several weeks. In mice lacking the essential cellular cofactor cyclophilin A (CypA), HCV RNA replication is markedly diminished, providing genetic evidence that this process is faithfully recapitulated. Using a cell-based fluorescent reporter activated by the NS3-4A protease we visualize HCV infection in single hepatocytes in vivo. Persistently infected mice produce de novo infectious particles, which can be inhibited with directly acting antiviral drug treatment, thereby providing evidence for the completion of the entire HCV life cycle in inbred mice. This genetically humanized mouse model opens new opportunities to dissect genetically HCV infection in vivo and provides an important preclinical platform for testing and prioritizing drug candidates and may also have utility for evaluating vaccine efficacy.
Deficits in cognitive function and hippocampal plasticity in GM2/GD2 synthase knockout mice
Authors: Sha Sha , Zhou Libin , Yin Jun , Takamiya Koga , Furukawa Keiko , Furukawa Koichi , Sokabe Masahiro , Chen Ling
Published: November 2013

In this study, we used GM2/GD2 synthase knockout (GM2/GD2−/−) mice to examine the influence of deficiency in ganglioside “a‐pathway” and “b‐pathway” on cognitive performances and hippocampal synaptic plasticity. Eight‐week‐old GM2/GD2−/− male mice showed a longer escape‐latency in Morris water maze test and a shorter latency in step‐down inhibitory avoidance task than wild‐type (WT) mice. Schaffer collateral‐CA1 synapses in the hippocampal slices from GM2/GD2−/− mice showed an increase in the slope of EPSPs with reduced paired‐pulse facilitation, indicating an enhancement of their presynaptic glutamate release. In GM2/GD2−/− mice, NMDA receptor (NMDAr)‐dependent LTP could not be induced by high‐frequency (100–200 Hz) tetanus or θ‐burst conditioning stimulation (CS), whereas NMDAr‐independent LTP was induced by medium‐frequency CS (20–50 Hz). The application of mono‐sialoganglioside GM1 in the slice from GM2/GD2−/− mice, to specifically recover the a‐pathway, prevented the increased presynaptic glutamate release and 20 Hz‐LTP induction, whereas it could not rescue the impaired NMDAr‐dependent LTP. These findings suggest that b‐pathway deficiency impairs cognitive function probably through suppression of NMDAr‐dependent LTP, while a‐pathway deficiency may facilitate NMDAr‐independent LTP through enhancing presynaptic glutamate release. As both of the NMDAr‐independent LTP and increased presynaptic glutamate release were sensitive to the blockade of L‐type voltage‐gated Ca2+ channels (L‐VGCC), a‐pathway deficiency may affect presynaptic L‐VGCC. © 2013 Wiley Periodicals, Inc.