bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of silicone dioxide and poly(ethylene glycol) on the conductivity and relaxation dynamics of poly(ethylene oxide)–silver triflate solid polymer electrolyte
Authors: Gondaliya Nirali , Kanchan D. K. , Sharma Poonam , Joge Prajakta
Published: January 2012

The conducting and relaxation dynamics of Ag+ ions in poly(ethylene oxide) (PEO)–silver triflate (AgCF3SO3) solid polymer electrolytes (SPEs) containing nanosize SiO2 filler and poly(ethylene glycol) (PEG) as a plasticizer were studied in the frequency range 10 Hz to 10 MHz and in the temperature range 303–328 K. The comparatively lower conductivity of the plasticized (PEG) PEO–AgCF3SO3–SiO2 nanocomposite electrolyte system was examined by analysis of the Fourier transform infrared (FTIR) spectroscopy and conductivity data. The electric modulus (M″) properties of the SPE systems were investigated. A shift of the M″ peak spectra with frequency was found to depend on the translation ion dynamics and the conductivity relaxation of the mobile ions. The value of the conductivity relaxation time was observed to be lower for the PEO–AgCF3SO3 system only with nanofiller SiO2. The scaling behavior of the M″ spectra showed that the dynamical relaxation processes was temperature‐independent in the PEO–AgCF3SO3 and PEO–AgCF3SO3–SiO2–PEG polymer systems, whereas they were temperature‐dependent for the PEO–AgCF3SO3–SiO2 system. However, the relaxation processes of all of theses systems were found to be dependent on their respective compositions. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Formation and characterization of polyamide composite electrospun nanofibrous membranes for salt separation
Authors: Kaur Satinderpal , Sundarrajan Subramanian , Gopal Renuga , Ramakrishna Seeram
Published: January 2012

Currently, electrospun nanofibrous membranes (ENMs) are classified in the microfiltration range. In this study, we explored the applicability of using ENMs for nanofiltration (NF) applications through a surface modification approach. A polyamide layer was formed on the surface of the ENMs through interfacial polymerization with two different approaches. In the first approach (approach A), ENMs were soaked in an aqueous phase followed by an organic phase; in the second approach (approach B), we reversed this sequence. This resulted in different surface morphologies over the ENM surface. The best approach B allowed the separation of 80.7% of 2000‐ppm MgSO4 and 67.0% of 2000‐ppm NaCl at a pressure of 70 psig under a dead‐end filtration setup. The fluxes attained were 0.51 and 0.52 L m−2 h−1, respectively. In addition, the effect of the pore size on the formation of a polyamide film was investigated. It was realized that bubble points of 1.8 and 3.4 μm were both able to support the polymer film on its surface, but their separation efficiency differed slightly. These findings suggest that ENMs could be used beyond their current microfiltration stage, and hence, their use could be widened to NF membranes. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Polymer‐Supported Enantioselective Bifunctional Catalysts for Nitro‐Michael Addition of Ketones and Aldehydes
Authors: Tuchman‐Shukron Lital , Miller Scott J. , Portnoy Moshe
Published: January 2012

Introduction of an L‐amino acid as a spacer and a urea‐forming moiety in a polymer‐supported bifunctional urea–primary amine catalyst, based on (1R, 2R)‐(+)‐1,2‐diphenylethylenediamine, significantly improves the catalyst’s activity and stereoselectivity in the asymmetric addition of ketones and aldehydes to nitroolefins. Yields and enantioselectivities, unprecedented for immobilized catalysts, were obtained with such challenging donors as acetone, cyclopentanone, and α,α‐disubstituted aldehydes, which usually perform inadequately in this reaction (particularly when a secondary‐amine‐based catalyst is used). Remarkably, though in the examined catalysts the D‐amino acids as spacers were significantly inferior to the L isomers, for the chosen configuration of the diamine (match–mismatch pairs) the size of the side chain of the amino acid hardly influenced the enantioselectivity of the catalyst. These results, combined with the reactivity profile of the catalysts with substrates bearing two electron‐withdrawing groups and the behavior of the catalysts’ analogues based on tertiary (rather than primary) amine, suggest an enamine‐involving addition mechanism and a particular ordered CC bond‐forming transition state as being responsible for the catalytic reactions with high enantioselectivity.
Lattice Effects on the Spin‐Crossover Profile of a Mononuclear Manganese(III) Cation
Authors: Pandurangan Komala , Gildea Brendan , Murray Caroline , Harding Charles J. , Müller‐Bunz Helge , Morgan Grace G.
Published: January 2012

Six solvated salts of a mononuclear manganese(III) complex with a chelating hexadentate Schiff base ligand are reported. One member of the series, [MnL]PF6.0.5 CH3OH (1), shows a rare low‐spin (LS) electronic configuration between 10–300 K. The remaining five salts, [MnL]NO3⋅ C2H5OH (2), [MnL]BF4⋅C2H5OH (3), [MnL]CF3SO3⋅C2H5OH (4), [MnL]ClO4⋅C2H5OH (5) and [MnL]ClO4⋅0.5 CH3CN (6), all show gradual incomplete spin‐crossover (SCO) behaviour. The structures of all were determined at 100 K, and also at 293 K in the case of 3–6. The LS salt [MnL]PF6.0.5 CH3OH is the only member of the series that does not exhibit strong hydrogen bonding. At 100 K two of the four SCO complexes (2 and 4) assemble into 1D hydrogen‐bonded chains, which weaken or rupture on warming. The remaining SCO complexes 3, 5 and 6 do not form 1D hydrogen‐bonded chains, but instead exhibit discrete hydrogen bonding between cation/counterion, cation/solvent or counterion/solvent and show no significant change on warming.
Fe‐Catalyzed Multicomponent Reactions: The Regioselective Alkoxy Allylation of Activated Olefins and its Application in Sequential Fe Catalysis
Authors: Dieskau André P. , Holzwarth Michael S. , Plietker Bernd
Published: January 2012

We present herein a versatile and broadly applicable Fe‐catalyzed regioselective alkoxy allylation of activated double bonds. Substituted allylic carbonates are converted into the corresponding σ‐enyl Fe complexes by reaction with Bu4N[Fe(CO)3(NO)] (TBAFe) at 30 °C. The liberated alkoxide adds to an activated double bond with the generation of a C‐nucleophile, which is trapped by the σ‐enyl Fe complex in a regioselective manner. Alternatively, the alkoxide acts as a base in deprotonating an external pronucleophile, which undergoes Michael addition. The method is characterized by a broad functional group tolerance, mild reaction conditions, low catalyst loadings, and high regioselectivities in favor of the ipso‐substitution product.
Photochemical Studies on 5‐Methylbicyclo[1.1.1]pentane Derivatives: p‐Orbital Overlap Controlled Enantioselectivity
Authors: Ma Manling , Yang Chao , Li Bing , Shao Yutian , Zhao Guolei , Xia Wujiong
Published: January 2012

The first example of the p‐orbital overlap controlled enantioselectivity of Norrish type II photocyclization reaction was described. Irradiation of 5‐methyl bicyclo[1.1.1]pentanyl ketone with UV in the solid state as well as in the acetonitrile solution afforded the Norrish/Yang photocyclization compound as the sole product. Solid‐state asymmetric photochemical studies using ionic chiral auxiliary technique led to the enantioselectivity as high as 60%. The results were rationalized by X‐ray single crystal structure.
DFT Studies of Ag‐Loading Intrinsic and Functionalized Single‐Walled Carbon Nanotubes
Authors: Zhang Zhuxia , Hao Yaxian , Wang Liping , Dong Minghui , Hou Wensheng , Han Peide , Liu Xuguang , Xu Bingshe
Published: January 2012

The first principles study was performed on the stability of Ag adsorbed on the internal walls of single‐walled carbon nanotube (SWCNT) and loaded on acid modified SWCNT. The calculation results show that Ag can be adsorbed stably on the internal walls of SWCNT. With the increase of SWCNT diameter, the adsorption energy increases in a certain range. Ag can also be loaded on the modified SWCNT surface in the form of COOAg and OAg groups, and COOAg group is more stable than OAg group. For either the adsorption on the inner SWCNT or the load on the modified SWCNT surface, only a small proportion of the Ag ions can be stably bonded to the walls of SWCNT.
Fabrication of a Sensitive Electrochemical Biosensor for Detection of DNA Hybridization Based on Gold Nanoparticles/CuO Nanospindles Modified Glassy Carbon Electrode
Authors: Zhang Yuzhong , Wang Mingzhu , Huang Lei
Published: January 2012

In this work, a sensitive electrochemical DNA biosensor for the detection of sequence‐specific target DNA was reported. Firstly, CuO nanospindles (CuO NS) were immobilized on the surface of a glassy carbon electrode (GCE). Subsequently, gold nanoparticles (Au NPs) were introduced to the surface of CuO NS by the electrochemical deposition mode. Probe DNA with SH (HS‐DNA) at the 5′‐phosphate end was covalently immobilized on the surface of the Au NPs through AuS bond. Scanning electron microscopy (SEM) was used to elucidate the morphology of the assembled film, and electrochemical impedance spectroscopy technique (EIS) was used to investigate the DNA sensor assembly process. Hybridization detection of DNA was performed with differential pulse voltammetry (DPV) and the methylene blue (MB) was hybridization indicator. Under the optimal conditions, the decline of reduction peak current of MB (ΔI) was linear with the logarithm of the concentration of complementary DNA from 1.0×10−13 to 1.0×10−6 mol·L−1 with a detection limit of 3.5×10−14 mol·L−1 (S/N=3). In addition, this DNA biosensor has good selectivity, and even can distinguish single‐mismatched target DNA.
Nitrite Ionic Liquids (IL‐ONO and [bmim]NO2) as Effective Nitrosonium Sources for the Synthesis of α‐Oximinoketones under Mild Heterogeneous Conditions
Authors: Valizadeh H. , Shomali A. , Gholipour H.
Published: January 2012

Ketones and β‐diketones were nitrosated and converted to their corresponding α‐oximinoketones using task‐specific ionic liquids, 1‐(4‐nitritobutyl)‐3‐methylimidazolium chloride, IL‐ONO, and 1‐butyl‐3‐methylimidazolium nitrite at room temperature. The results from two ionic liquids are comparable and showed that these IL's are effective nitrosonium sources for the preparation of oximinoketones. The protocol is rapid, the yields are excellent, and the method is simple.
Synthesis, Characterization and Ion Exchange Properties of a New Composite of Inorganic Ion Exchanger: Polyacrylonitrile Cerium(IV) Molybdophosphate
Authors: Ahmadi Seyed Javad , Yavari Ramin , Ashtari Parviz , Gholipour Vanik , Kamel Leila , Rakhshandehru Farokh
Published: January 2012

In this work, the synthesis of the composite of cerium(IV) molybdophosphate (CMP) and polyacrylonitrile (PAN) was reported (CMP‐PAN). The material has been characterized by elemental and spectral (FT‐IR), X‐ray and thermal (TGA) analysis. Also the size analysis of the composite was done by scanning electron microscopy (SEM). Its chemical stability in acidic, basic and saline solutions and radiation stability up to 100 kGy total expose dose were assessed. Whereas the synthesized composite has ion exchange properties, its ion exchange capacity and behavior toward several metal ions were also investigated. Further, the distribution coefficients of the metal ions were calculated. Finally, the ability of the synthesized CMP‐PAN composite for the decontamination of low level liquid waste (LLLW) was investigated.
Effect of Different Leachate/Acetate Ratios in a Submerged Anaerobic Membrane Bioreactor (SAnMBR)
Authors: Taskan Ergin , Hasar Halil
Published: January 2012

Leachate treatment using a membrane bioreactor is an effective method. This study presents a configuration including an anaerobic bioreactor and a membrane module, called submerged anaerobic membrane bioreactor (SAnMBR), for treating influent with leachate/acetate rations (L/A), that were kept to be 10, 25, 50, 75, and 100% at a constant SRT (100 days). COD removal decreased from 85 to 75% when the L/A ratio increased from 10 to 100. To prevent membrane fouling, a SAnMBR was operated in the case of circulation of mixed liquor under continuous and intermittent suction. The average fluxes were 2.60 and 0.40 L/m2 h at the periods of intermittent and continuous suction, respectively. The methane production varied between 0.25 and 0.32 L CH4/g CODremoved.
Ultrasound‐Assisted Emulsification–Microextraction Combined with Graphite Furnace Atomic Absorption Spectrometry for the Determination of Trace Lead in Water
Authors: Jiang Hongmei , Zhang Yu , Qiu Bocheng , Li Wenhua
Published: January 2012

The ultrasound‐assisted emulsification–microextraction (USAEME) method was combined with graphite furnace atomic absorption spectrometry (GFAAS) for the determination of trace Pb using dithizone (H2DZ) as chelating reagent. Some effective parameters influenced the detection and microextraction, such as ashing temperature and atomization temperature, pH, extraction solvent, sample volume, extraction time, and extraction temperature were selected and optimized. After extraction, the calibration curves for Pb was in the concentration range of 0.1–10 ng mL−1, and the linear equation was y = 0.097 x + 0.023 (R = 0.99). Under the optimized conditions, the detection limit of the method was 20 pg mL−1 with an enrichment factor of 70 and the relative standards deviation (RSD) for seven determinations of 1 ng mL−1 Pb was 11%. The proposed method was successfully applied to determine trace Pb in Yueya Lake water, pond water, and spiked samples. Furthermore, a certified reference material of Environment Water (GBW08607) was analyzed and the determined value was in good agreement with the certified value, which showed the accuracy, recovery, and applicability of the reported method.
Outwitting smart selfish nodes in wireless mesh networks
Authors: Chong Zan‐Kai , Tan Su‐Wei , Goi Bok‐Min , Ng Bryan Cheng‐Kuan
Published: January 2012

Selfish nodes are nodes that are reluctant to forward packets for others in wireless mesh networks. One of the effective techniques to remove them is to share the information of identified selfish nodes in the network. However, most selfish node detection schemes rarely address the trustworthiness of their shared information in the network. It turns devastating if smart selfish nodes are able to manipulate the shared information. We propose a detection framework named Separation of Detection Authority, which delegates the detection process to different entities. Particularly, its detection efficacy is modelled as the probability to have majority neighbours of nodes consist of well‐behaved node. Our analytic and simulation results show that the decentralised nature of Separation of Detection Authority is effective against these smart selfish nodes in static wireless mesh network. Copyright © 2012 John Wiley & Sons, Ltd.
Nickel‐Catalyzed Cross‐Coupling with Pincer Ligands
Authors: Wang Zhong‐Xia , Liu Ning
Published: January 2012

Transition‐metal‐catalyzed cross‐coupling reactions are powerful tools for constructing carbon–carbon and carbon–heteroatom bonds. In this microreview we summarize the nickel‐catalyzed cross‐coupling reactions with pincer ligands. The reactions presented here include Kumada, Negishi, Suzuki, and Sonogashira reactions for the formation of different types of C–C bonds, as well as the thiolation of aryl iodides.
Synthesis, Structures, and Transfer Hydrogenation Catalysis of Bifunctional Iridium Complexes Bearing a C–N Chelate Oxime Ligand (Eur. J. Inorg. Chem. 3/2012)
Authors: Watanabe Megumi , Kashiwame Yohei , Kuwata Shigeki , Ikariya Takao
Published: January 2012

The back cover picture shows the structure of a dinuclear organometallic oxime complex, which exhibits metal–ligand bifunctional reactivity upon dissociation to the mononuclear hydrido–oxime complex and coordinatively unsaturated oximato complex. These mononuclear species are easily converted to each other through proton‐coupled hydride transfer with alcohols and ketones. Owing to metal–ligand cooperation, the dinuclear complex efficiently catalyzes the transfer hydrogenation of ketones with 2‐propanol. Details are discussed in the article by S. Kuwata, T. Ikariya et al. on p. 504 ff.
Cis and trans components of lipids: Analysis by 1H NMR and silver shift reagents
Authors: Agiomyrgianaki Alexia , Sedman Jacqueline , Van de Voort Frederik R. , Dais Photis
Published: January 2012

In this study, the methodology of shift reagents was exploited to distinguish cis and trans unsaturation in oils and fats. The differential binding of silver ions (in the form of AgFOD) to cis and trans double bonds allowed the separation of the allylic and olefinic proton signals in the 1H NMR spectra of mixtures of cis and trans methyl esters of monoene aliphatic acids and unsaturated triacylglycerol mixtures at low frequency spectrometers (300 MHz). Careful integration of the appropriate proton resonances in the recorded quantitative 1H NMR spectra afforded percentage concentrations in very good agreement with the actual values. This 1H NMR methodology was validated by analyzing AOCS Laboratory Proficiency Program GC samples containing various percentages of saturated, cis‐mono unsaturated, and cis‐polyunsaturated fat as well as trans content. This fast and relatively low‐cost NMR methodology could be used on line for obtaining nutrition labeling compositional data (NLCD) required for fat‐containing food products. Attempts to differentiate lipid molecules with different degree of unsaturation and positional distribution of cis double bonds were unsuccessful.
Anthracene‐Labeled 1,2,3‐Triazole‐Linked Bispyridinium Amide for Selective Sensing of H2PO4– by Fluorescence and Gel Formation
Authors: Ghosh Kumaresh , Sarkar Avik Ranjan , Chattopadhyay Asoke P.
Published: January 2012

A new receptor 1 has been designed and synthesized for the selective recognition of anions, which employs hydrogen bonding and electrostatic interactions. Receptor 1 selectively recognizes H2PO4– to exhibit a ratiometric emission response and formed a stable gel in CHCl3 that contained 10 % CH3CN, which is useful to visually sense H2PO4–. In comparison, receptor 2 did not form a gel with H2PO4– under similar conditions. Upon interaction with H2PO4–, the intensity of the monomer and excimer emission peaks of 2 increased markedly. Moreover, F– ions induced quenching of monomer emission in both 1 and 2 in a nonratiometric manner, which distinguished it from the other anions examined.
Development of an Integrated System for Immobilization and Mediating Charge to Alcohol Dehydrogenase During Bioelectrocatalytic Oxidation and Detection of Ethanol
Authors: Kowalewska Barbara , Kulesza Pawel J.
Published: January 2012

A robust biocatalytic electrode film utilizing multiwalled carbon nanotubes intentionally derivatized with poly(diallyldimethylammonium chloride), PDDA, as well as integrated with alcohol dehydrogenase is considered here for potential application as a stable efficient anode in a biofuel cell and a specific working electrode in amperometric sensors. PDDA‐modified CNTs were characterized using transmission electron microscopy (TEM) and infrared spectroscopy (FTIR). Once immobilized on a glassy carbon electrode substrate, they facilitate not only distribution of charge but also immobilization of alcohol dehydrogenase molecules. The resulting integrated bioelectrocatalytic system was able to induce oxidation of ethanol and NADH as well as to produce relatively high currents at a fairly low potential.
Application of NiMoO4 Nanorods for the Direct Electrochemistry and Electrocatalysis of Hemoglobin with Carbon Ionic Liquid Electrode
Authors: Hu Song , Cao Lili , Sun Zhaolan , Xiang Jun , Lu Ming , Sun Wei
Published: January 2012

In this paper NiMoO4 nanorods were synthesized and used to accelerate the direct electron transfer of hemoglobin (Hb). By using an ionic liquid (IL) 1‐butylpyridinium hexafluorophosphate (BPPF6) modified carbon paste electrode (CILE) as the basic electrode, NiMoO4 nanorods and Hb composite biomaterial was further cast on the surface of CILE and fixed by chitosan (CTS) to establish a modified electrode denoted as CTS/NiMoO4‐Hb/CILE. UV‐vis and FT‐IR spectroscopic results showed that Hb in the film retained its native structures without any conformational changes. Electrochemical behaviors of Hb entrapped in the film were carefully investigated by cyclic voltammetry with a pair of well‐defined and quasi‐reversible redox voltammetric peaks appearing in phosphate buffer solution (PBS, pH 3.0), which was attributed to the direct electrochemistry of the electroactive center of Hb heme Fe(III)/Fe(II). The results were ascribed to the specific characteristic of NiMoO4 nanorods, which accelerated the direct electron transfer rate of Hb with the underlying CILE. The electrochemical parameters of Hb in the composite film were further carefully calculated with the results of the electron transfer number (n) as 1.08, the charge transfer coefficient (α) as 0.39 and the electron‐transfer rate constant (ks) as 0.82 s−1. The Hb modified electrode showed good electrocatalytic ability toward the reduction of trichloroacetic acid (TCA) in the concentration range from 0.2 to 26.0 mmol/L with a detection limit of 0.072 mmol/L (3σ), and H2O2 in the concentration range from 0.1 to 426.0 µmol/L with a detection limit of 3.16×10−8 mol/L (3σ).
NADH Oxidation Catalyzed by Electropolymerized Azines on Carbon Nanotube Modified Electrodes
Authors: Li Hanzi , Wen Hao , Calabrese Barton Scott
Published: January 2012

Electropolymerizing azines on a carbon nanotube (CNT) modified electrode yields a high‐surface area interface with excellent electrocatalytic activity towards NADH oxidation. Electrodeposition of poly(methylene green) (PMG) and poly(toluidine blue) (PTBO) on the carboxylated CNT‐modified electrodes was achieved by cyclic voltammetry. The PMG‐CNT interface demonstrates 5.0 mA cm−2 current density for NADH oxidation at 50 mV vs. Ag|AgCl in 20 mM NADH solution. The kinetics of NADH electrocatalysis were analyzed using a quantitative mass‐transport‐corrected model with NADH bulk concentration and applied potential as independent variables. This high‐rate poly(azine)‐CNT interface is potentially applicable to high‐performance bioconversion, bioenergy and biosensors involving NADH‐dependent dehydrogenases.
Voltammetric Analysis of Phytochelatin Complexation in Ternary Metal Mixtures Supported by Multivariate Analysis and ESI‐MS
Authors: Cavanillas Santiago , Gusmão Rui , Ariño Cristina , Díaz‐Cruz José Manuel , Esteban Miquel
Published: January 2012

The competitive binding of Cu2+, Cd2+ and Pb2+ in ternary mixtures by the phytochelatins PC2 and PC5 (PCn; (γGlu‐Cys)n‐Gly, n=2 and 5) are examined by voltammetry, which allows one to follow the displacements of the voltammetric signals induced by the competitive binding among the metal ions towards PC2 or PC5 complexation, and direct injection positive‐mode Electrospray Ionization Mass Spectrometry (ESI‐MS), in order to obtain the stoichiometries of the complexes. Voltammetric data are analyzed by Gaussian Peak Adjustment (GPA), which is a recently developed multivariate analysis method for nonlinear electrochemical data. Different complexes have been detected or deduced their presence, depending on the experimental conditions. Ternary complexes CuCdPCn and CdPbPCn were detected for both PC2 and PC5, while the ternary CuPbPCn complex was only detected for PC2. Some of the complexes have been only detected by ESI‐MS because in some cases voltammetry data could not be totally resolved, even by using GPA. The quaternary CdPbCuPCn complex has been detected for PC5, but for PC2 data are not so conclusive. In summary, the signal evolution for mixed CdCuPCn complexes is quite different. These observations could be a reflection of an antagonistic effect for the case of PC2 and a synergetic one for PC5.
Knowledge and Attitudes of Psychiatrists Towards Eating Disorders
Authors: Jones William R. , Saeidi Saeideh , Morgan John F.
Published: January 2012

Objective

This study examined the eating disorder mental health literacy of psychiatrists.

Method

A sample of psychiatrists completed a questionnaire measuring knowledge of and attitudes towards eating disorders. Knowledge questions were based on the academic literature, standard diagnostic criteria and national guidelines on the management of eating disorders. Attitude items covered beliefs about the aetiology and treatment of eating disorders, confidence levels in diagnosis and management and the use of compulsory measures in anorexia nervosa.

Results

Psychiatrists' knowledge of eating disorders was variable with specific gaps in both diagnosis and management. Psychiatrists felt more confident in diagnosing eating disorders than managing these conditions. Attitudes towards eating disorders were less stigmatizing than those seen in other health professionals.

Discussion

There is a clear need for greater education of psychiatrists regarding the diagnosis and management of eating disorders. Implementing training programmes and making information readily available could contribute to addressing these issues. Copyright © 2012 John Wiley & Sons, Ltd and Eating Disorders Association.
Exploring debris‐flow history and process dynamics using an integrative approach on a dolomitic cone in western Austria
Authors: Procter Emily , Stoffel Markus , Schneuwly‐Bollschweiler Michelle , Neumann Mathias
Published: January 2012

The evolution of a debris‐flow cone depends on a multitude of factors in the hydrogeomorphic system. Investigations of debris‐flow history and cone dynamics in highly active catchments therefore require an integrative approach with a temporal and spatial resolution appropriate for the goals of the study. We present the use of an orthophoto time series to augment standard dendrogeomorphic techniques to describe the spatio‐temporal dynamics of debris flows on a highly active cone in the western Austrian Alps. Analysis of seven orthophotos since 1951 revealed a migration of active deposition areas with a resulting severe loss of forest cover (> 80%) and a mean tree loss per year of 10·4 (range 1·3–16·6 trees per year). Analysis of 193 Pinus mugo ssp. uncinata trees allowed the identification of 161 growth disturbances corresponding to 16 debris flows since 1839 and an average decadal frequency of 0·9 events. As a result of the severe loss of forest cover, we speculate that < 20% of the more recent events were actually captured in the tree‐ring record, giving a decadal return interval of ~7·5 events for a period of 60 years. Based on three annual field observations, it is evident that this catchment (the Bärenrüfe) produces very frequent (< 1 yr), small (in the order of a few 10 to 100 m3) debris flows with minor material relocation. The specific challenges of tree‐ring analysis in this tree species and in highly active environments are explicitly addressed in the discussion and underline the necessity of employing complementary methods of analysis in an integrative manner. Copyright © 2012 John Wiley & Sons, Ltd.
Modelling sediment dynamics due to hillslope–river interactions: incorporating fluvial behaviour in landscape evolution model LAPSUS
Authors: Baartman Jantiene E. M. , van Gorp Wouter , Temme Arnaud J. A. M. , Schoorl Jeroen M.
Published: January 2012

Landscape evolution models (LEMs) simulate the three‐dimensional development of landscapes over time. Different LEMs have different foci, e.g. erosional behaviour, river dynamics, the fluvial domain, hillslopes or a combination. LEM LAPSUS is a relatively simple cellular model operating on timescales of centuries to millennia and using annual timesteps that has had a hillslope focus. Our objective was to incorporate fluvial behaviour in LAPSUS without changing the existing model equations. The model should be able to reproduce alternating aggradation and incision in the floodplains of catchments, depending on simulated conditions. Testing was done using an artificial digital elevation model (DEM) and a demonstration of the ability for fluvial simulation was performed for a real landscape (Torrealvilla catchment, southeast Spain).

Model equations to calculate sediment dynamics and water routing were similar for both hillslope and fluvial conditions, but different parameter values were used for these domains, defined based on annual discharge. Parameters changing between the domains are convergence factor p, which is used in the multiple flow algorithm to route water, and discharge and gradient exponents m and n, used in transport capacity calculations.

Erodibility and ‘sedimentability’ factors K and P were changed between cold (little vegetation, high erodibility) and warm conditions (more vegetation, lower erodibility). Results show that the adapted parameters reproduced alternating aggradation – due to divergent flow in the floodplain and sediment supply under cold conditions – and incision due to reduced sediment supply and resulting clean water erosion during simulated warm conditions. The simulated results are due to interactions between hillslopes and floodplains, as the former provide the sediments that are deposited in the latter. Similar behaviour was demonstrated when using the real DEM. Sensitivity and resolution analysis showed that the model is sensitive to changes in m, n and p and that model behaviour is influenced by DEM resolution. Copyright © 2012 John Wiley & Sons, Ltd.
Discrete maximum principle based on repair technique for diamond type scheme of diffusion problems
Authors: Wang Shuai , Yuan Guangwei , Li Yonghai , Sheng Zhiqiang
Published: January 2012

In this paper, two repair techniques are proposed for diamond schemes of anisotropic diffusion problems to ensure that the repaired solutions satisfy the discrete maximum principle. One of them is an extension of that in [Liska R, Shashkov M. Enforcing the discrete maximum principle for linear finite element solutions of second‐order elliptic problems. Communications in Computational Physics 2008; 3(4):852–877.] for linear finite element solutions, which is a local repair technique, and another is a new global repair technique. Both of them keep total energy conservation and are easy to be implemented in existing codes. Numerical examples show that these two repair techniques do not destroy the accuracy of solution for the diamond schemes on distorted meshes. Copyright © 2012 John Wiley & Sons, Ltd.
Investigating the stability of neuropsychiatric sub‐syndromes with progression of dementia: a 2‐year prospective study
Authors: Bettney Laura , Butt Shameem , Morris Julie , Connolly Amanda , McCollum Charles , Burns Alistair , Purandare Nitin
Published: January 2012

Objectives

Previous studies have identified sub‐syndromes of behavioral and psychological symptoms of dementia. But because of their cross‐sectional design, the stability of these sub‐syndromes over time remains unknown.

Method

Behavioral and psychological symptoms of dementia of 84 participants (out of an original sample of 144 patients) with Alzheimer's disease and vascular dementia were assessed by using the Neuropsychiatric Inventory every six months for two years. Principal component factor analysis with Varimax rotation was used to detect neuropsychiatric sub‐syndromes at each time point.

Results

The 12 symptoms were reduced to four factors at baseline, 12, 18, and 24 months and three factors at six months. None of the factor structures matched the four sub‐syndromes previously identified by studies. The most stable group of symptoms were a combination of “psychosis” and “hyperactivity” symptoms (delusions, hallucinations, irritability, agitation), which became stable at 18 months.

Conclusions

The pattern of behavioral and psychological symptoms of dementia sub‐syndromes over time has not been studied before, and this research suggests that some stability is evident particularly during the later stages of the disease process. These findings have implications for patients and their caregiver. Copyright © 2012 John Wiley & Sons, Ltd.
Does fish oil prevent cardiac arrhythmias?
Authors: Stanley John
Published: January 2012

It is widely accepted that the very long chain n‐3 polyunsaturated fatty acids (VLC n‐3 PUFA) characteristic of marine oils protect against the development of cardiovascular disease (CVD). This idea is supported by a large body of consistent epidemiological studies showing favourable associations between intakes of VLC n‐3 PUFA and CVD risk and more importantly by several large and lengthy dietary intervention trials showing favourable effects of VLC n‐3 PUFA on the development of CVD. The effects of VLC n‐3 PUFA on sudden death and on survival from a heart attack demonstrated in these trials could be explained if they have anti‐arrhythmic effects. Recent meta‐analyses of the available dietary intervention trials suggest that neither ventricular nor atrial arrhythmias are influenced by VLC n‐3 PUFA intakes. Hence a convincing mechanism of action of VLC n‐3 PUFA on CVD has yet to emerge.
Connectivity of thalamo‐cortical pathway in rat brain: combined diffusion spectrum imaging and functional MRI at 11.7 T
Authors: Kim Young Beom , Kalthoff Daniel , Po Chrystelle , Wiedermann Dirk , Hoehn Mathias
Published: January 2012

Fiber tracking in combination with functional MRI has recently attracted strong interest, as it may help to elucidate the structural basis for functional connectivities and may be selective in the determination of the fiber bundles responsible for a particular circuit. Diffusion spectrum imaging provides a more complex analysis of fiber circuits than the commonly used diffusion tensor imaging approach, also allowing the discrimination of crossing fibers in the brain. For the understanding of pathophysiological alterations during brain lesion and recovery, such studies need to be extended to small‐animal models. In this article, we present the first study combining functional MRI with high‐resolution diffusion spectrum imaging in vivo. We have chosen the well‐characterized electrical forepaw stimulation paradigm in the rat to examine the thalamo‐cortical pathway. Using the functionally activated areas in both thalamus and somatosensory cortex as seed and target regions for fiber tracking, we are able to characterize the fibers responsible for this stimulation pathway. Moreover, we show that the selection of the thalamic nucleus and primary somatosensory cortex on the basis of anatomical description results in a larger fiber bundle, probably encompassing connectivities between the thalamus and other areas of the somatosensory cortex, such as the hindpaw and large barrel field cortex. Copyright © 2012 John Wiley & Sons, Ltd.
Detection of ≥1 Mb microdeletions and microduplications in a single cell using custom oligonucleotide arrays
Authors: Bi Weimin , Breman Amy , Shaw Chad A. , Stankiewicz Pawel , Gambin Tomasz , Lu Xinyan , Cheung Sau Wai , Jackson Laird G. , Lupski James R. , den Veyver Ignatia B. Van , Beaudet Arthur L.
Published: January 2012

Objective

High resolution detection of genomic copy number abnormalities in a single cell is relevant to preimplantation genetic diagnosis and potentially to noninvasive prenatal diagnosis. Our objective is to develop a reliable array comparative genomic hybridization (CGH) platform to detect genomic imbalances as small as ~1 Mb in a single cell.

Methods

We empirically optimized the conditions for oligonucleotide‐based array CGH using single cells from multiple lymphoblastoid cell lines with known copy number abnormalities. To improve resolution, we designed custom arrays with high density probes covering clinically relevant genomic regions.

Results

The detection of megabase‐sized copy number variations (CNVs) in a single cell was influenced by the number of probes clustered in the interrogated region. Using our custom array, we reproducibly detected multiple chromosome abnormalities including trisomy 21, a 1.2 Mb Williams syndrome deletion, and a 1.3 Mb CMT1A duplication. Replicate analyses yielded consistent results.

Conclusion

Aneuploidy and genomic imbalances with CNVs as small as 1.2 Mb in a single cell are detectable by array CGH using arrays with high‐density coverage in the targeted regions. This approach has the potential to be applied for preimplantation genetic diagnosis to detect aneuploidy and common microdeletion/duplication syndromes and for noninvasive prenatal diagnosis if single fetal cells can be isolated. © 2012 John Wiley & Sons, Ltd.
Microstructural Characterization and Fatigue Performance Evaluation of MIG‐Welded Ship Hull Steel
Authors: Mondal Biplab Kumar , Pal Tapan Kumar , Maity Joydeep
Published: January 2012

The effectiveness of MIG welding with Argo‐shield gas & ER70S‐6 electrode in joining LRS (Grade‐B) steel was investigated through structure–property correlation of the joint region. Microstructure, tensile and fatigue properties, and mode of fracture (SEM fractograph) were correlated. Fatigue behavior has been investigated in air and sea water with thin specimen at near‐endurance stress amplitude up to 105 cycles. The crack growth rate (da/dN) maintained a non‐linear relationship with logarithm of stress intensity factor range (logΔK) for the near‐threshold values of ΔK. Considerable hardness and microstructural variation was observed across the weldment. Weld with more pearlite content was found to possess higher hardness and strength than the parent steel. Though, both in weld and in parent steel, either in air or in sea water, fatigue crack propagated at very slow rate with significant intermittent crack arrest, weld provided much higher resistance to crack growth in air. However, sea water accelerated the crack growth in weld and brought it closer to that in the parent steel. The morphologically complex microstructure of weld suffered much faster crack propagation in sea water than in air. While fatigue fracture in parent steel (both in air and sea water) and weld in air was found to occur through dimple rupture via microvoid coalescence, weld in sea water exhibited a mixed mode of failure.
Titanium Containing High Strength Sulfuric Acid Corrosion Resistant Steel
Authors: Guo Hairong , Li Tingting , Li Hualong , Toshihiko Emi
Published: January 2012

Ti containing low alloy steel free of Sb is found to have higher strength than and equivalent sulfuric acid corrosion (SAC) resistance to traditional SAC resistant steels in CuCrSb system. SAC resistance of the Ti containing steel was investigated with potentiodynamic polarization, linear polarization resistance, electrochemical impedance spectroscopy, and weight loss measurements in a solution of 20 wt% H2SO4 at 20°C. All measurements confirm that Ti addition is suitable for designing high strength SAC resistant steels.
Peak factors of non‐Gaussian wind forces on a complex‐shaped tall building
Authors: Huang Mingfeng , Lou Wenjuan , Chan Chun‐Man , Bao Sheng
Published: January 2012

This paper focuses on the development of peak factor formulas of non‐Gaussian wind pressure processes after reviewing the current estimation methods of non‐Gaussian peak factors. A skewness‐dependent peak factor is proposed by accounting for the contribution of skewness and kurtosis parameters in some existing Hermite moment‐based formulas. The possible correction on the upcrossing rate used in the translation process approach is also investigated. Wind tunnel pressure data on a practical 43‐story building with unusual shape is used to validate the accuracy of the skewness‐dependent peak factor by investigating various statistical properties of wind‐induced fluctuating pressure field on the complex‐shaped tall building example. Copyright © 2012 John Wiley & Sons, Ltd.
Novel spreading codes for multicarrier code division multiple access based cognitive radio networks with sidelobe suppression
Authors: Rajabzadeh Morteza , Khoshbin Hossein
Published: January 2012

The deployment of multicarrier code division multiple access as the transmission scheme of the spectrum overlay based cognitive radio (CR) networks faces two challenging issues: (i) the need for spreading codes with arbitrary length and (ii) the interfering effect of the leaked power (due to spectral sidelobes) to the adjacent spectral band used by the primary system. To meet these challenges, we propose two novel complex spreading code sets. For this purpose, a cost function is defined as the ratio of the power leaked to the adjacent primary band to the power transmitted to the band allowed for CR operation. The cost function is shown to be convertible to a trace ratio problem. The two complex spreading code sets are determined by deploying two different standard solutions. The first is the conventional but approximate solution based on generalized eigenvalue decomposition (GEVD) method, and the other is an iterative algorithm that converges to the optimal solution and hence outperforms the GEVD based solution. Simulation results show that by a slight decrease in number of users, the code set yielded by iterative algorithm suppresses the leaked power to almost zero. The applicability of the proposed code sets in different scenarios is discussed. Copyright © 2012 John Wiley & Sons, Ltd.
Simple linear string constraints
Authors: Fu Xiang , Powell Michael C. , Bantegui Michael , Li Chung-Chih
Published: January 2012

Modern web applications often suffer from command injection attacks. Even when equipped with sanitization code, many systems can be penetrated due to software bugs. It is desirable to automatically discover such vulnerabilities, given the bytecode of a web application. One approach would be symbolically executing the target system and constructing constraints for matching path conditions and attack patterns. Solving these constraints yields an attack signature, based on which, the attack process can be replayed. Constraint solving is the key to symbolic execution. For web applications, string constraints receive most of the attention because web applications are essentially text processing programs. We present
simple linear string equation (SISE)
, a decidable fragment of the general string constraint system. SISE models a collection of regular replacement operations (such as the greedy, reluctant, declarative, and finite replacement), which are frequently used by text processing programs. Various automata techniques are proposed for simulating procedural semantics such as left-most matching. By composing atomic transducers of a SISE, we show that a recursive algorithm can be used to compute the solution pool, which contains the value range of each variable in concrete solutions. Then a concrete variable solution can be synthesized from a solution pool. To accelerate solver performance, a symbolic representation of finite state transducer is developed. This allows the constraint solver to support a 16-bit Unicode alphabet in practice. The algorithm is implemented in a Java constraint solver called SUSHI. We compare the applicability and performance of SUSHI with Kaluza, a bounded string solver.
Metabolic decompensation in methylmalonic aciduria: which biochemical parameters are discriminative?
Authors: Zwickler Tamaris , Haege Gisela , Riderer Alina , Hörster Friederike , Hoffmann Georg F. , Burgard Peter , Kölker Stefan
Published: January 2012

Recurrent, life‐threatening metabolic decompensations often occur in patients with methylmalonic aciduria (MMAuria). Our study evaluated (impending) metabolic decompensations in these patients aiming to identify the most frequent and reliable clinical and biochemical abnormalities that could be helpful for decision‐making on when to start an emergency treatment. Seventy‐six unscheduled and 179 regular visits of 10 patients with confirmed MMAuria continuously followed by our metabolic centre between 1975 and 2009 were analysed. The most frequent symptom of an impending acute metabolic decompensation was vomiting (90% of episodes), whereas symptoms of intercurrent infectious disease (29%) or other symptoms (such as food refusal and impaired consciousness) were found less often. Thirty‐five biochemical parameters were included in the analysis. Among them, pathological changes of acid–base balance reflecting metabolic acidosis with partial respiratory compensation (decreased pH, pCO2, standard bicarbonate, and base excess) and elevated ammonia were the most reliable biochemical parameters for the identification of a metabolic decompensation and the estimation of its severity. In contrast, analyses of organic acids, acylcarnitines and carnitine status were less discriminative. In conclusion, careful history taking and identification of suspicious symptoms in combination with a small number of rapidly available biochemical parameters are helpful to differentiate compensated metabolic condition and (impending) metabolic crisis and to decide when to start an emergency treatment.
Genetic Testing Integration Panels (GTIPs): A Novel Approach for Considering Integration of Direct‐To‐Consumer and Other New Genetic Tests into Patient Care
Authors: Uhlmann Wendy R. , Sharp Richard R.
Published: January 2012

There has been a dramatic increase in the number of genetic tests available but few tests have practice guidelines. In addition, many tests have become available outside of clinical settings through direct‐to‐consumer (DTC) companies and several offer tests not considered standard of care. To address several practical challenges associated with the rapid introduction of clinical and DTC genetic tests, we propose that genetic counselors and geneticists organize expert panels in their institutions to discuss the integration of new tests into patient care. We propose the establishment of Genetic Testing Integration Panels (GTIPs) to bring together local experts in medical genetics, genetic counseling, bioethics and law, health communication and clinical laboratory genetics. We describe key features of this approach and consider some of the potential advantages and limitations of using a GTIP to address the many clinical challenges raised by rapidly emerging clinical and DTC genetic tests.
Water Solubilization Using Nonionic Surfactants from Renewable Sources in Microemulsion Systems
Authors: Szumała Patrycja , Szeląg Halina
Published: January 2012

In this study the effect of temperature, NaCl and oils (hydrocarbons: C8–C16) on the formation and solubilization capacity of the systems of oil/monoacylglycerols (MAG):ethoxylated fatty alcohols (CEO20)/propylene glycol (PG)/water was investigated. The effects of the surfactant mixture on the phase behavior and the concentration of water or oil in the systems were studied at three temperatures (50, 55, 60 °C) and with varied NaCl solutions (0.5; 2; 11%). Electrical conductivity measurement, FTIR spectroscopy and the DSC method were applied to determine the structure and type of the microemulsions formed. The dimension of the microemulsion droplets was characterized by dynamic light scattering. It has been stated that the concentration of CEO20has a strong influence on the shape and extent of the microemulsion areas. Addition of a nonionic surfactant to the mixture with MAG promotes an increase in the area of microemulsion formation in the phase diagrams, and these areas of isotropic region did not change considerably depending on the temperature, NaCl solution and oil type. It was found that, depending on the concentration of the surfactant mixture, it was possible to obtain U‐type microemulsions with dispersed particles size distribution ranging from 25 to 50 nm and consisting of about 30–32% of the water phase in the systems. The conditions under which the microemulsion region was found (electrolyte and temperature—insensitive, comparatively low oil and surfactant concentration) could be highly useful in detergency.