bluuebunny/crossref_metadata_2025_split huggingface dataset:
Principal components methods for narrow‐sense heritability in the analysis of multidimensional longitudinal cognitive phenotypes
Authors: Fung Wai Lun Alan , Naylor Melissa G. , Bennett David A. , Lange Christoph , Blacker Deborah 
Published: May 2013

AbstractBackgroundGenetic association studies of longitudinal cognitive phenotypes are an alternate approach to discovering genetic risk factors for Alzheimer's disease (AD). However, the standard linear mixed model approach is limited in the face of multidimensional longitudinal data and multiple genotypes. In this setting, the principal components of heritability (PCH) approach may increase efficiency by deriving a linear combination of phenotypes to maximize the heritability attributable to a particular genetic locus. The current study investigated the performance of two PCH methods, the Principal Components of Heritability Association Test (PCHAT) and C2BAT, in detecting association of the known AD susceptibility allele APOE‐ϵ4 with cognitive function at baseline and decline in cognition over time.MethodsPCHAT, C2BAT, and standard linear mixed models were used to test for association between APOE‐ϵ4 allele and performance on 19 neuropsychological tests using subjects without dementia at baseline from the Religious Orders Study (ROS) (n = 693) and Memory and Aging Project (MAP) (n = 778). Analyses were conducted across the three methods for three nested phenotype definitions (all 19 measures, executive function and episodic memory measures, and episodic memory only), and for baseline data only versus longitudinal change.ResultsIn all cases, APOE‐ϵ4 was significantly associated with baseline level of and change over time in cognitive function, and PCHAT and C2BAT yielded evidence of association comparable to or stronger than conventional methods.ConclusionPCHAT, C2BAT, and other PCH methods may have utility for genetic association studies of multidimensional cognitive and other phenotypes by maximizing genetic information while limiting multiple comparisons. Copyright © 2013 Wiley Periodicals, Inc.
Improving aging resistance and mechanical properties of waterborne polyurethanes modified by lignin amines
Authors: Liu Jun , Liu Hai‐Feng , Deng Li , Liao Bing , Guo Qing‐Xiang 
Published: May 2013

ABSTRACTIn this article, we report the enhanced anti‐aging and mechanical properties of waterborne polyurethanes (WPUs) modified by lignin amines, which were prepared from lignins, formaldehyde, and diethylenetriamine via a Mannich reaction. When we introduced amino groups into the lignin, its solubility in water and reactivity with isocyanate was obviously improved. Consequently, the interaction between WPU and the lignin additive were promoted; this provided a higher mechanical performance, that is, a higher tensile strength and elongation at break. More importantly, the intrinsic antioxidative activity of lignin also benefitted the modified WPU in terms of aging resistance. According to artificial accelerated aging tests, mechanical measurement, attenuated total reflectance–Fourier transform infrared spectroscopy, and scanning electron microscopy analysis, the lignin amine modified WPU did not show any evidence of degradation after 2 months of artificial accelerated aging, whereas the pure WPU was obviously degraded. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 1736–1742, 2013
Influence of absorbing materials on the functionalization of poly(tetrafluoroethylene) during γ‐irradiation
Authors: Hoffmann Thorsten , Heller Marcel , Jehnichen Dieter , Engelhardt Thomas , Lehmann Dieter 
Published: May 2013

ABSTRACTThis contribution describes the effect of absorbing materials on the functionalization and the concentration of radicals of poly(tetrafluoroethylene) (PTFE) during the γ‐irradiation compared to the results without absorbing materials. Different absorbing calcium‐based materials were used to study their efficiency to avoid the release of fluorinated gases that occur within the irradiation procedure in the environment. It was found, that the type of the absorbing material had a significant effect on the formation and concentration of functional groups (carbonyl fluoride, carboxylic acid) and persistent radicals within the radiation‐treated PTFE samples. In addition, by means of wide angle X‐ray scattering (WAXS) the quantitative determination of fluorine (F−) concentration after irradiation in the absorbing materials could be followed. It may be used for scientific investigations of radiation induced PTFE chain scission mechanisms as well as for the monitoring of industrial γ‐irradiation processes. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 1787–1793, 2013
Possibilities of Archaeological Prospection by High‐resolution X‐band Satellite Radar – a Case Study from Syria
Authors: Linck R. , Busche T. , Buckreuss S. , Fassbinder J. W. E. , Seren S. 
Published: May 2013

ABSTRACTThe launch of the first German radar satellite TerraSAR‐X in 2007 opened a new era in spaceborne radar remote sensing. So far the applicability for the high‐resolution prospection of upstanding and, especially, buried monuments was limited because of the low resolution of the former sensors. TerraSAR‐X, however, provides us with images with a spatial resolution of up to 1 m. The satellite operates in the so‐called X‐band with a frequency of 9.65 GHz. Therefore it is supposed that there is no possibility to penetrate the soil with this sensor. To testify and analyse the benefit of TerraSAR‐X in archaeological geophysics, we chose as a test site a Roman fortress in Syria. The site was chosen as we already have GPR data of the same area for a comparison and for the verification of the actual penetration depth. Our results revealed that it is possible to resolve superficial and even buried structures in the data set, which provides evidence that the X‐band waves can penetrate the soil. This paper shows our results of the survey and an estimation of the possible penetration depth of TerraSAR‐X. Copyright © 2013 John Wiley & Sons, Ltd.
Oligothiophene‐Bridged Bis(arylene ethynylene) Small Molecules for Solution‐Processible Organic Solar Cells with High Open‐Circuit Voltage
Authors: Liu Qian , Zhan Hongmei , Ho Cheuk‐Lam , Dai Feng‐Rong , Fu Yingying , Xie Zhiyuan , Wang Lixiang , Li Jin‐Hua , Yan Feng , Huang Shu‐Ping , Wong Wai‐Yeung 
Published: May 2013

AbstractA new series of conjugated oligothiophene‐bridged bis(arylene ethynylene) small molecules have been designed, synthesized, and characterized by photophysical, electrochemical and computational methods. These compounds were found to have optimal LUMO levels that ensure effective charge transfer from these compounds to [6,6]‐phenyl‐C71‐butyric acid methyl ester (PC70BM). They were utilized as good electron‐donor materials that can be blended with electron‐acceptor PC70BM in the fabrication of solution‐processed molecular bulk heterojunction (BHJ) solar cells. All of these BHJ devices showed very high open‐circuit voltage (Voc) of 0.90–0.97 V, and the best power conversion efficiency achieved was 3.68 %. The high Voc is consistent with the deeper low‐lying HOMO level and is relatively insensitive to the donor : acceptor blend ratio. The spin‐coated thin films of these small molecules showed p‐channel field‐effect charge transport with the hole mobilities of up to 2.04×10−4 cm2 V−1 s−1. These compounds illuminate the potential of solution‐processible small‐molecular aryl acetylide compounds for efficient power generation in photovoltaic implementation.
The Effect of Intuitive Advice Justification on Advice Taking
Authors: Tzioti Stefanie C. , Wierenga Berend , van Osselaer Stijn M. J. 
Published: May 2013

ABSTRACTHow do you respond when receiving advice from somebody with the argumentation “my gut tells me so” or “this is what my intuition says”? Most likely, you would find this justification insufficient and disregard the advice. Are there also situations where people do appreciate such intuitive advice and change their opinion accordingly? A growing number of authors write about the power of intuition in solving problems, showing that intuitively made decisions can be of higher quality than decisions based on analytical reasoning. We want to know if decision makers, when receiving advice based on an intuitive cognitive process, also recognize the value of such advice. Is advice justified by intuition necessarily followed to a lesser extent than an advice justified by analysis? Furthermore, what are the important factors influencing the effect of intuitive justification on advice taking? Participants across three studies show that utilization of intuitive advice varies depending on advisor seniority and type of task for which the advice is given. Summarizing, the results suggest that decision makers a priori doubt the value of intuitive advice and only assess it as accurate if other cues in the advice setting corroborate this. Intuitively justified advice is utilized more if it comes from a senior advisor. In decision tasks with experiential products, intuitively justified advice can even have more impact than analytically justified advice. Copyright © 2013 John Wiley & Sons, Ltd.
Functional monolithic platforms: Chromatographic tools for antibody purification
Authors: Barroso Telma , Hussain Abid , Roque Ana C. A. , Aguiar‐Ricardo Ana 
Published: May 2013

AbstractPolymer monoliths are an efficient platform for antibody purification. The use of monoclonal antibodies (mAbs) and engineered antibody structures as therapeutics has increased exponentially over the past few decades. Several approaches use polymer monoliths to purify large quantities of antibody with defined clinical and performance requirements. Functional monolithic supports have attracted a great deal of attention as they offer practical advantages for antibody purification, such as more rapid analysis, smaller sample volume requirements and the opportunity for a greater target molecule enrichment. This review focuses on the development of synthetic and natural polymer‐based monoliths for antibody purification. The materials and methods employed in monolith production are discussed, highlighting the properties of each system. We also review the structural characterization techniques available using monolithic systems and their performance under different chromatographic approaches to antibody capture and release. Finally, a summary of monolithic platforms developed for antibody separation is presented, as well as expected trends in research to solve current and future challenges in this field. This review comprises a comprehensive analysis of proposed solutions highlighting the remarkable potential of monolithic platforms.
Pd Ultra‐Small Clusters as Precursors for Silica‐Encapsulated Pd Nanoreactors: Highly Sinter‐Resistant Catalysts
Authors: Samanta Anupam , Devi R. Nandini 
Published: May 2013

AbstractSintering and consequent deactivation in supported metal catalysts is a severe problem encountered in heterogeneous catalysis. This problem can be addressed by encapsulating active metal nanoparticles within inert oxides such as silica, provided the oxide shell is porous to enable access of reactant molecules to the nanoparticle surface to facilitate catalysis. We report the synthesis of highly sinter‐resistant silica‐encapsulated Pd catalysts with nanoparticle sizes stabilized at (3.4±0.6) nm at high temperatures of approximately 750 °C. The synthesis was achieved by utilizing thiol‐protected ultra‐small clusters of Pd as precursors for silica encapsulation. The ultra‐small clusters were synthesized by using propyl ammonium functionalised thiols making them water‐dispersible and amenable for silica encapsulation. Abundance of organics also aided in creating porosity subsequent to calcination at high temperatures.
Connecting Discrete Stereoclusters by Using DFT and NMR Spectroscopy: The Case of Nivariol
Authors: Cen‐Pacheco Francisco , Rodríguez Jaime , Norte Manuel , Fernández José J. , Hernández Daranas Antonio 
Published: May 2013

AbstractThe structural determination of small organic molecules is mainly undertaken by using NMR techniques, although it is increasingly supplemented by using computational methods. NMR parameters, such as chemical shifts and coupling constants, are extremely sensitive indicators of local molecular conformation and are a source of structural evidence. However, their interpretation is fairly challenging in many circumstances, such as the case of the new polyether squalene derivative nivariol, the structure of which was elucidated by means of NMR spectroscopy and DFT calculations. The potential flexibility of this molecule and the high number of quaternary carbon atoms that it contains make its configurational assignment very difficult. Moreover, the relative configuration of four separated stereoclusters was established and subsequently connected by using NOE and J‐based analysis, as well as by a comparison of its experimental 13C NMR chemical shifts with the corresponding population‐weighted values, as calculated by using DFT methods. Limitations of these used approaches became apparent but were overcome by combining the two methods.
Experimental and Numerical Investigation of a Rising Droplet
Authors: Eiswirth René T. , Bart Hans‐Jörg , Atmakidis Theodoros , Kenig Eugeny Y. 
Published: May 2013

AbstractErgebnisse einer experimentellen und numerischen Untersuchung eines in einer wässrigen Phase aufsteigenden Toluol‐Tropfens werden vorgestellt. Die experimentellen Untersuchungen wurden in einer Messzelle im Kleinstmaßstab unter Zuhilfenahme von Hochgeschwindigkeitsmesstechnik durchgeführt. Die numerischen Untersuchungen erfolgten mithilfe des CFD‐Programms COMCOL Multiphysics 3.3a und der dort implementierten Level‐Set‐Methode. Die gemessenen und die in Simulationen berechneten Tropfenaufstiegsgeschwindigkeiten zeigen eine sehr gute Übereinstimmung und decken sich mit neueren Ergebnissen. Auch die Wiedergabe der Abweichung von der Kugelform bei verschiedenen Tropfengrößen war ausgezeichnet. Auf Basis der experimentell und numerisch erhaltenen Ergebnisse wird eine verbesserte Anpassung einer bestehenden Korrelation zur Berechnung der Tropfenaufstiegsgeschwindigkeit vorgestellt.
Numerical Simulation of Polydispersed Flow in Bubble Columns with the Inhomogeneous Multi‐Size‐Group Model
Authors: Ziegenhein Thomas , Rzehak Roland , Krepper Eckhard , Lucas Dirk 
Published: May 2013

AbstractThe present paper shows the influence of considering polydispersity of bubbly flow, simulating bubble columns with a three‐dimensional Eulerian two‐fluid model. A complete set of interfacial closure models regarding drag force, lift force, wall force, turbulent dispersion force and bubble‐induced turbulence is considered. A round bubble column of 0.288 m diameter and 2.5 m height is simulated up to a superficial gas velocity of 1 cm s–1 and compared with experimental data. It is shown that considering the polydispersity including the non‐drag forces, important flow properties of bubble columns are reproduced. Possible influences of swarm effects on the non‐drag forces are discussed and needs for further investigations are given.
Gamma‐Ray Computed Tomography for Imaging of Multiphase Flows
Authors: Bieberle André , Härting Hans‐Ulrich , Rabha Swapna , Schubert Markus , Hampel Uwe 
Published: May 2013

AbstractMultiphase flows are omnipresent in the chemical industry. The flow phenomena in multiphase reactors strongly affect the processes performance. Nonetheless, even basic information on flow patterns, flow regimes and effects of internals etc. is often not available, which is a strong obstacle for a reliable design and scale‐up. Non‐invasive tomographic techniques are promising measurement tools to visualize opaque multiphase flows. The contribution provides a short survey about today's tomographic imaging techniques and introduces the principles of radiation‐based tomography. In particular, two gamma‐ray computed tomography designs and their application for sparger performance study in large bubble columns and for flow regime determination in inclined rotating fixed‐bed reactors are presented.
Coherent Anti‐Stokes Emission from Gold Nanorods and its Potential for Imaging Applications
Authors: Jiang Li , Schie Iwan W. , Qian Jun , He Sailing , Huser Thomas 
Published: May 2013

AbstractWe used coherent anti‐Stokes scattering (CAS) to characterize individual gold nanorods (GNRs) and GNR aggregates. By creating samples with different densities of GNRs on silicon wafer substrates, we were able to determine surface coverage by scanning electron microscopy (SEM) and then correlate the coverage to the CAS intensities of the samples. The observed CAS signal intensity was quadratically dependent on the number of particles. We also examined the CAS signal as a function of the excitation polarization and found that the strongest signals in regularly oriented GNRs were observed when the beam polarization was aligned with the longitudinal axis of the GNRs. Irregularly oriented GNRs exhibited a different scattering pattern to that observed for regularly oriented GNRs. The polarization‐dependent scattering from oriented GNRs showed cos6 (θ) behavior. By imaging nanoscale‐sized GNR patterns using CAS and evaluating the results with SEM, we show that CAS can be used for efficient, label‐free imaging of nanoscale metallic particles.
Experimental and First‐Principles Characterization of Functionalized Magnetic Nanoparticles
Authors: Antipas Georgios S. E. , Statharas Eleftherios , Tserotas Philippos , Papadopoulos Nikolaos , Hristoforou E. 
Published: May 2013

AbstractMagnetic iron oxide nanoparticles synthesized by coprecipitation and thermal decomposition yield largely monodisperse size distributions. The diameters of the coprecipitated particles measured by X‐ray diffraction and transmission electron microscopy are between approximately 9 and 15 nm, whereas the diameters of thermally decomposed particles are in the range of 8 to 10 nm. Coprecipitated particles are indexed as magnetite‐rich and thermally decomposed particles as maghemite‐rich; however, both methods produce a mixture of magnetite and maghemite. Fourier transform IR spectra reveal that the nanoparticles are coated with at least two layers of oleic acid (OA) surfactant. The inner layer is postulated to be chemically adsorbed on the nanoparticle surface whereas the rest of the OA is physically adsorbed, as indicated by carboxyl OH stretching modes above 3400 cm−1. Differential thermal analysis (DTA) results indicate a double‐stepped weight loss process, the lower‐temperature step of which is assigned to condensation due to physically adsorbed or low‐energy bonded OA moieties. Density functional calculations of Fe–O clusters, the inverse spinel cell, and isolated OA, as well as OA in bidentate linkage with ferrous and ferric atoms, suggest that the higher‐temperature DTA stage could be further broken down into two regions: one in which condensation is due ferrous/ferrous– and/or ferrous/ferric–OA and the other due to condensation from ferrous/ferric– and ferric/ferric–OA complexes. The latter appear to form bonds with the OA carbonyl group of energy up to fivefold that of the bond formed by the ferrous/ferrous pairs. Molecular orbital populations indicate that such increased stability of the ferric/ferric pair is due to the contribution of the low‐lying Fe3+ t2g states into four bonding orbitals between −0.623 and −0.410 a.u.
Multifunctional Macrocyclic Receptors as Templates for Aromatic Amino Acids: A Rare Example of a Highly Selective Multi‐Input Multi‐Output Chemo‐“Logic Gate”
Authors: Fraschetti Caterina , Filippi Antonello , Crestoni Maria Elisa , Ema Tadashi , Speranza Maurizio 
Published: May 2013

AbstractProton‐bound [M⋅H⋅G]+ diastereomeric complexes between some chiral aromatic amino acids or dipeptides (G) and a chiral multifunctional macrocyclic receptor (M=Chirabite‐A) undergo, in the gas phase, highly selective substitution and addition reactions by amines, such as 2‐aminobutane and piperidine. All the [M⋅H⋅G]+ complexes follow time‐dependent monoexponential decays. In some cases, the kinetic curves exhibit a plateau revealing the presence of unreactive [M⋅H⋅G]+ structures. In them, the amino acid is accommodated in the macrocycle cavity in the zwitterionic form by sharing its acidic hydrogen atoms with the pyridine nitrogen atoms of the host. The same interactions are structurally inaccessible to G=dipeptides or monofunctional amines, which then can be readily released from [M⋅H⋅G]+. When the amino acid interacts with the amidocarbonyl oxygen atoms pointing outside the macrocycle cavity, it saves the canonical structure and can be readily displaced by the amine. The Chirabite‐A may act as an efficient template for aromatic amino acids by releasing them or not depending upon the amino acid configuration and the basicity of the amine. These unique properties confer to the gas‐phase diastereomeric [M⋅H⋅G]+ complexes the features of multi‐input multi‐output chemo‐“logic gates”.
In Situ Generation Technology of β‐But­oxycarbonyliodonium Ylide: A Hyperva­lent Analogue of the Darzens Reagent
Authors: Miyamoto Kazunori , Suzuki Mai , Suefuji Takashi , Ochiai Masahito 
Published: May 2013

AbstractAn ester exchange reaction of β‐butoxy‐β‐acyloxyvinyl‐λ3‐iodane with lithium bases (ROLi and nBuLi) efficiently generates highly labile monoester iodonium ylide at low temperature. The iodonium ylide generated in situ cleanly undergoes Darzens condensation with aromatic aldehydes to afford trans‐epoxy ester selectively.
β‐Cyclodextrin Incorporated Carbon Nanotube Paste Electrode as Electrochemical Sensor for Nifedipine
Authors: Kor Kamalodin , Zarei Kobra 
Published: May 2013

AbstractIn this work a carbon paste electrode modified with multiwalled carbon nanotubes/β‐cyclodextrin (MWCNTs/β‐CD) was constructed and applied to the determination of nifedipine. The electrochemical behavior of nifedipine at this electrode was investigated using cyclic voltammetry and differential pulse voltammetry. Characterization of the modified electrode was conducted with electrochemical impedance spectroscopy and scanning electron microscopy. After adsorption of nifedipine on the MWCNTs/β‐CD paste electrode at 0.0 V for 6 min, a well defined reduction peak was produced in sodium hydroxide of 0.05 M. The calibration curve was linear from 7.0×10−8 to 1.5×10−5 M. The detection limit was obtained as 2.5×10−8 M. The results demonstrated that this electrochemical sensor has excellent sensitivity and selectivity. This sensor was applied for determination of nifedipine in drug dosage and blood serum with excellent recoveries.