bluuebunny/crossref_metadata_2025_split huggingface dataset:
Red to Green Switch Driven by Order in an Ionic IrIII Liquid‐Crystalline Complex
Authors: Szerb Elisabeta I. , Talarico Anna M. , Aiello Iolinda , Crispini Alessandra , Godbert Nicolas , Pucci Daniela , Pugliese Teresa , Ghedini Mauro 
Published: June 2010

AbstractNew cationic IrIII materials of general formula [Ir(ppy)2(Cn‐bpy)]PF6 {H(ppy) = 2‐phenylpyridine; Cn‐bpy = 3,4,5‐R‐4,4′‐benzoyloxymethyl‐2,2′‐bipyridine; n = 8, R = OC8H17; n = 0, R = H} were synthesised and fully characterised. Both complexes show high phosphorescence quantum yields in their condensed phases. Moreover, the introduction of long alkoxy chains on the bipyridne ligand in [Ir(ppy)2(C8‐bpy)]PF6 (1) has induced mesomorphism, and consequently a dynamic functional material with properties modulated by external stimuli has been obtained. Starting from the isotropic phase, on slow cooling a crystalline phase characterised by a bright green emission is obtained. However, on fast cooling a kinetically favoured columnar hexagonal mesophase is preferentially formed, which is stable down to room temperature. In this phase, the high luminescence is still maintained, even if a switch to yellow emission colour is observed. Moreover, through spin coating of solutions of 1, it has been possible to obtain its amorphous thin film to accomplish a further shift of the emission wavelength in the orange‐red spectral range. A fully reversible colour tuning process by surface stress and heating from the orange‐red film to the green crystalline phase, indicative of a mechanochromic behaviour, is also achieved.
Novel Synthetic Strategy towards the Efficient Synthesis of Substituted Bis(pyrazolyl)(2‐pyridyl)methane Ligands
Authors: Hoffmann Alexander , Flörke Ulrich , Schürmann Markus , Herres‐Pawlis Sonja 
Published: June 2010

AbstractA general one‐pot synthesis of new substituted heteroscorpionate ligands is presented. These mixed‐functionality ligands were obtained in a catalyzed Peterson rearrangement starting from the substituted pyrazole, thionyl chloride, and an aldehyde. Thus, the synthesis of polyfunctional tridentate ligands is enabled, and they contain, besides the two pyrazole groups, other functionalities relevant for coordination chemistry. Additionally, the steric hindrance is easily defined in the ligands by the substitution of the pyrazole rings. By combination of the versatility in donor function and steric demand, a systematic tuning of the properties of the bis(pyrazolyl)methane ligands is possible. The synthesis and full characterization of 11 bis(pyrazolyl)methane ligands are reported. Two of these were structurally characterized as well.
Orthogonal Regioselective Synthesis of N‐Alkyl‐3‐substituted Tetrahydroindazolones
Authors: Kim Jonghoon , Song Heebum , Park Seung Bum 
Published: June 2010

AbstractA divergent strategy for the regioselective and orthogonal synthesis of complementary regioisomers of N‐alkyl‐3‐substituted‐tetrahydroindazolones 3 and 4 was achieved from Boc‐protected alkylhydrazines 1. The robustness and substrate generality of this method were validated by synthesizing 3 and 4 through the intra‐ and intermolecular condensation of 1 with various 2‐acylcyclohexane‐1,3‐diones 2 and aldehydes, respectively.
Outdoor to indoor channel characteristics on two different floors
Authors: Wang Wei , Jost Thomas , Dammann Armin 
Published: June 2010

AbstractRecently the fusion of positioning and wireless communication has gained many interests due to the merits of location information for future communication systems. Both positioning and wireless communication are highly dependent on the air channel. Current channel models are well suited for communication applications but less for positioning. Therefore, we investigate and compare the channel characteristics of different floors in favour of positioning based on an outdoor to indoor broadband channel sounder measurement campaign. Power delay profiles on both floors show similar structure caused by outdoor wave propagation, and angle of arrivals mostly arrive from the same direction. Differences can be seen in the RMS delay spread, power, NLoS error and coherence characteristics. Copyright © 2010 John Wiley & Sons, Ltd.
Semi‐implicit subgrid modelling of three‐dimensional free‐surface flows
Authors: Casulli Vincenzo , Stelling Guus S. 
Published: June 2010

SUMMARYIn this paper, a semi‐implicit numerical model for two‐ and three‐dimensional free‐surface flows will be formulated in such a fashion as to intrinsically account for subgrid bathymetric details. It will be shown that with the proposed subgrid approach the model accuracy can be substantially improved without increasing the corresponding computational effort. Copyright © 2010 John Wiley & Sons, Ltd.
Curvilinear finite elements for Lagrangian hydrodynamics
Authors: Dobrev V. A. , Ellis T. E. , Kolev Tz. V. , Rieben R. N. 
Published: June 2010

AbstractWe have developed a novel high‐order, energy conserving approach for solving the Euler equations in a moving Lagrangian frame, which is derived from a general finite element framework. Traditionally, such equations have been solved by using continuous linear representations for kinematic variables and discontinuous constant fields for thermodynamic variables; this is the so‐called staggered grid hydro (SGH) method. From our general finite element framework, we can derive several specific high‐order discretization methods and in this paper we introduce a curvilinear finite element method which uses continuous bi‐quadratic polynomial bases (the Q2 isoparametric elements) to represent the kinematic variables combined with discontinuous (mapped) bi‐linear bases to represent the thermodynamic variables. We consider this a natural generalization of the SGH approach and show that under simplifying low‐order assumptions, we exactly recover the classical SGH method. We review the key parts of the discretization framework and demonstrate several practical advantages to using curvilinear finite elements for Lagrangian shock hydrodynamics, including: the ability to more accurately capture geometrical features of a flow region, significant improvements in symmetry preservation for radial flows, sharper resolution of a shock front for a given mesh resolution including the ability to represent a shock within a single zone and a substantial reduction in mesh imprinting for shock waves that are not aligned with the computational mesh. Copyright © 2010 John Wiley & Sons, Ltd.
Reversed arterial flow in the paramedian segments of the liver after pancreaticoduodenectomy
Authors: Di Domenico Stefano , Santacroce Elena , Magoni Rossi Arianna , Giannone Antonella , Valente Umberto 
Published: June 2010

AbstractVariation of splanchnic arterial anatomy is frequent and may complicate pancreatic surgery, leading to life‐threatening postoperative complications. We report a case of severe hepatic dysfunction after pancreaticoduodenectomy due to accidental section of the right hepatic artery. Bedside ultrasound examination showed a reversed arterial flow in the paramedian segments of the liver. Based on intraoperative and ultrasound findings, a retrograde arterial supply of the right liver from the left hepatic artery through spontaneous anastomosis between the arteries of segment 4 and the right paramedian segments was assumed and confirmed by postoperative CT examination. © 2010 Wiley Periodicals, Inc. J Clin Ultrasound 39:99–103, 2011
Novel parameter for the diagnosis of distal middle cerebral artery stenosis with transcranial Doppler sonography
Authors: Ahn Suk‐Won , Park Sang‐Soon , Lee Yong‐Seok 
Published: June 2010

AbstractPurposeTranscranial Doppler sonography (TCD) is commonly used for the diagnosis of middle cerebral artery (MCA) stenosis. However, TCD indices to predict distal MCA (M2) stenosis have not yet been established. We compared TCD and magnetic resonance angiography (MRA) to validate a new index for the diagnosis of M2 stenosis.MethodsConsecutive patients who underwent TCD and MRA were included. Based on MRA, M2 stenosis was defined as >50% narrowing beyond the bifurcation area. TCD index of the M2/M1 ratio was defined as the ratio between the mean flow velocity (MFV) obtained at a depth of 30–44 mm (M2) and a depth of 45–65 mm (M1). Sensitivity and specificity of the M2/M1 ratio were calculated from the receiver operating characteristic curve. The diagnostic yield of elevated MFV (>80 cm/s) and asymmetry index of >30% for M2 stenosis were also investigated.ResultsAmong the consecutive patients, 105 with M2 stenosis were compared with 123 without MCA stenosis. The M2/M1 ratio was significantly higher in the M2 stenosis group (1.10 versus 0.86, p < 0.001). Sensitivity and specificity for M2 stenosis were most satisfying when the M2/M1 ratio of 0.97 was adopted as the cutoff value. Diagnostic yield of the M2/M1 ratio was better than MFV or asymmetry index.ConclusionsThe M2/M1 ratio may be a highly specific parameter for assessing M2 stenosis with TCD. © 2010 Wiley Periodicals, Inc. J Clin Ultrasound 38:420–425, 2010
Cystic change in thyroid carcinoma: Prevalence and estimated volume in 360 carcinomas
Authors: Henrichsen Tara L. , Reading Carl C. , Charboneau J. William , Donovan Daniel J. , Sebo Thomas J. , Hay Ian D. 
Published: June 2010

AbstractPurpose.The aim of this study was to determine the prevalence and amount of cystic change in thyroid cancer. This study also examined associated sonographic characteristics of cystic malignant thyroid nodules to help recognize these clinically important nodules.Methods.This study was a retrospective review of 360 malignant thyroid nodules surgically removed at our institution between January 1, 2002 and December 31, 2004. All patients had signed research authorization. All patients had preoperative sonograms and surgical pathologic proof of their thyroid malignancy. The 360 malignant nodules were found in 307 patients. All scans were performed using 7‐ to 15‐MHz transducers, and most studies included a digital video clip of the cancer. The preoperative ultrasound examinations were retrospectively reviewed by three radiologists and a sonographer. An estimate of cystic component percentage was derived by consensus. The presence of a mural nodule, thick irregular wall, microcalcifications, and prominent vascularity was also recorded.Results.Of the 360 carcinomas, 318 (88.3%) were solid to minimally (less than 5%) cystic, 33 (9.2%) were 6–50% cystic, 9 (2.5%) were 51–100% cystic. Of the nine (2.5%) malignancies that were greater than 50% cystic, all had other suspicious findings including mural nodules, microcalcifications, increased vascularity, and/or a thick irregular wall about the cystic portion.Conclusion.The vast majority (88%) of thyroid cancer is uniformly solid or has minimal (1–5%) cystic change by sonography. Marked cystic change (>50% of the nodule) occurred in only 2.5% of cancers, which had other sonographic findings worrisome for malignancy. © 2010 Wiley Periodicals, Inc. J Clin Ultrasound 38:361‐366, 2010
Learning from errors: The role of context, emotion, and personality
Authors: Zhao Bin 
Published: June 2010

AbstractThis research focused on the relationship between negative emotionality and learning from errors. Specifically, negative emotionality was expected to impair learning from errors by decreasing motivation to learn. Perceived managerial intolerance of errors was hypothesized to increase negative emotionality, whereas emotional stability was proposed to decrease negative emotionality. All the hypotheses were tested in a laboratory simulation. Contrary to the prediction, a positive association was found between negative emotionality and motivation to learn. The effects of perceived managerial intolerance of errors and emotional stability on negative emotionality were as predicted. Moreover, exploratory data analyses were conducted at the level of specific negative emotions and revealed differentiated effects of specific negative emotions on learning from errors. Copyright © 2010 John Wiley & Sons, Ltd.
Work‐life flow: How individuals, Zappos, and other innovative companies achieve high engagement
Authors: Perschel Anne 
Published: June 2010

AbstractIndividuals, their coaches, and visionary leaders, including Zappos CEO Tony Hsieh, are aligning work and culture with the principles of flow to enrich careers, lives, and organizations. This article examines flow—an individual's state of maximum engagement—and the criteria for achieving it. It spells out methods for coaching people to achieve a state of flow at work, and then presents examples of how individuals have infused their jobs with flow. It also discusses several visionary leaders who incorporate flow states into their companies' culture, including an in‐depth look at how Hsieh uses flow principles to create high engagement and deliver superior business results. © 2010 Wiley Periodicals, Inc.
Storytelling at Juniper Networks connects a global organization to the values and behaviors of success
Authors: Ohara Stacey Clark , Cherniss Mariah 
Published: June 2010

AbstractCulture had begun to drift in this high‐tech company, and new challenges called for some new behaviors to position the business for its second decade. Storytelling became the perfect tool to foster a deeper understanding of the company culture and unite employees across the organization, and it is now a key organizational capability for sustaining the Juniper Way. The authors describe the impact of growth on the culture of this start‐up, and detail a comprehensive storytelling initiative to integrate Juniper values and desired behaviors into a now global organization. They also discuss the ways storytelling was recently used to help launch a new business strategy and brand identity. © 2010 Wiley Periodicals, Inc.
Effect of acetonitrile–water mixtures on the reaction of dinitrochlorobenzene and dinitrochlorobenzotrifluoride with hydroxide ion
Authors: El‐Mallah N. M. , Senior S. A. , Nabil G. M. , Ramadan M. Sh. , Hamed E. A. 
Published: June 2010

AbstractThe kinetics of alkaline hydrolysis of 2‐chloro‐3,5‐dinitrobenzotrifluoride 1 and 1‐chloro‐2,4‐dinitrobenzene 2 were studied in various acetonitrile–water (AN–H2O) mixtures (10–90% w/w) at different temperatures. Thermodynamic parameters ΔH# and ΔS# show great variation, whereas ΔG# appears to vary little with the solvent composition presumably due to compensating variations. The results are discussed in terms of the solvent parameters such as preferential solvation, dielectric constant, polarity/polarizability, and hydrogen bond donor and acceptor parameters. It has been found that the factors controlling the reaction rates are the desolvation of OH−, the solvophobicity of the medium, and free water molecules in rich AN mixed solvent. The data showed that the solvatochromic parameters of (AN–H2O) mixed solvent are destroyed in the presence of excess OH−. © 2010 Wiley Periodicals, Inc. Int J Chem Kinet 42: 453–463, 2010
A Core‐First Preparation of Poly(3‐alkylthiophene) Stars
Authors: Senkovskyy Volodymyr , Beryozkina Tetyana , Bocharova Vera , Tkachov Roman , Komber Hartmut , Lederer Albena , Stamm Manfred , Severin Nikolai , Rabe Jürgen P. , Kiriy Anton 
Published: June 2010

AbstractA new and facile method for the preparation of mono‐ and hexa‐functional Ni‐bipyridyl‐based initiators that mediate Kumada polycondensation of 2‐bromo‐5‐chloromagnesio‐3‐hexylthiophene into head‐to‐tail regioregular poly(3‐hexylthiophene), P3HT, has been developed. An important advantage of the catalytic system presented herein is the ease of the preparation of a number of Ar‐Nibipy‐Br initiators from readily available aryl halides. As an example, the “core‐first” synthesis of 6‐arm star‐like P3HT having a hexaphenylbenzene core is demonstrated.
New Trends in Poly(ethylene oxide) or Polystyrene Macromonomer Based Networks Exhibiting Silsesquioxane Cross‐Linking Points
Authors: Harris Hassan , Nohra Bassam , Gavat Odile , Lutz Pierre J. 
Published: June 2010

AbstractPoly(ethylene oxide) (PEO) hydrogels and polystyrene (PS) networks were synthesized in toluene by coupling α,ω‐diallyl PEO or α,ω‐diundecenyl PS macromonomers with octafunctional silsesquioxanes via hydrosilylation in the presence of a “Speier” catalyst. Their equilibrium swelling degree and uniaxial compression modulus could be controlled by the synthesis parameters, i.e. the solvent, the macromonomer molar mass and the macromonomer concentration.
Photo‐Plasticity in Thiol‐ene Network Polymers – A Review
Authors: Cook Wayne D. , Chen Fei , Nghiem Quoc Dat , Scott Timothy F. , Bowman Christopher N. , Chausson Sophie , Le Pluart Loic 
Published: June 2010

AbstractIn this paper we briefly overview the area of stimuli responsive polymers and the subset of photo‐plastic polymers which change shape or undergo stress relaxation during irradiation. The chemistry, mechanism and properties of a new class of photo‐plastic polymers is presented in detail – these tetrathiol‐diene networks contain an allylic dithioether (also termed allylic disulphide) unit in the network strands and when this moiety is attacked by a photogenerated radical, the allylic dithioether undergoes β‐cleavage which breaks one network bond and reforms another. Two different methods of integration of the allylic dithioether unit into the backbone are investigated – the use of a cyclic allylic dithioether which copolymerizes with a thiol‐ene system or the incorporation of the allylic dithioether moiety in a divinyl ether monomer which can directly copolymerize with the thiol. The photo‐plasticity effect of these thiol‐ene networks is revealed in both creep and stress relaxation experiments, however, the extent of photo‐plasticity is less extensive than expected. The polymerization kinetics and evolution of the rheological properties during photocuring are studied and the slower copolymerization of the monomer containing the allylic dithioether is discussed. The photo‐rheology and dynamic mechanical properties of the thiol‐ene networks are interpreted in terms of the network structure.
Mechanism of Peroxide Cross‐Linking of EPDM Rubber
Authors: van Duin Martin , Orza Ramona , Peters Ron , Chechik Victor 
Published: June 2010

AbstractThe results of three experimental studies, i.e. GC‐MS of peroxide‐cross‐linked alkene/alkane mixtures, 13C NMR of peroxide‐cured, 13C‐labeled 2‐ethylidene‐5‐norbornene ‐ ethylene‐propylene‐diene‐monomer (EPDM) and EPR of peroxide curing of EPDM, are combined, yielding a more accurate description of the mechanism of peroxide cure of EPDM. Both alkyl and allyl macro‐radicals are formed via H‐abstraction from the EPM main chain and the residual diene unsaturation, respectively. Combination of these macro‐radicals yields alkyl/alkyl, alkyl/allyl and allyl/allyl cross‐links and addition of these macro‐radicals to the residual diene unsaturation yields alkyl/alkene and allyl/alkene cross‐links.
Stimulus–Responsive Nematic Gels
Authors: Urayama Kenji 
Published: June 2010

AbstractNematic elastomers exhibit a rich variety of stimulus–response behaviors owing to their hybrid characters of liquid crystals and elastomers. The nematic elastomers swollen by low molecular mass liquid crystals show anisotropic swelling, and their volume and shape significantly depend on temperature. The swollen nematic elastomers exhibit macroscopic deformation together with a large change in optical birefringence in fast response to electric fields (electro–opto–mechanical effect). The mechanical stretching of the nematic elastomers normal to the initial director drives the director realignment along the elongation axis.
Liquid Crystal Elastomers with Magnetic Actuation
Authors: Winkler Moritz , Kaiser Andreas , Krause Simon , Finkelmann Heino , Schmidt Annette M. 
Published: June 2010

AbstractMagneto‐active liquid crystal elastomers (LCEs) are accessible by the incorporation of superparamagnetic Fe3O4 nanoparticles into oriented nematic side‐chain LCEs and offer a contactless activation pathway to the nematic‐to‐isotrope transition by local magnetic heating in external fields. In magneto‐mechanical measurements, a sample contraction of up to 30% is observed under field influence, with full reversibility when the field is switched off. The load evolved reaches 60 kPa and more. The ability of the materials to respond to a contactless electromagnetic stimulus with a well‐defined contraction can be of use for various actuator applications.
Micellar Solutions of a Symmetrical Amphiphilic ABA Triblock Copolymer with a Temperature‐Responsive Shell
Authors: Jain A. , Kulkarni A. , Koumba A. M. Bivigou , Wang W. , Busch P. , Laschewsky A. , Müller‐Buschbaum P. , Papadakis C. M. 
Published: June 2010

AbstractWe have studied the thermal behavior of an ABA triblock copolymer having short, deuterated polystyrene end‐blocks and a longer poly(N‐isopropyl acrylamide) middle block, the latter exhibiting a lower critical solution temperature. The collapse of the micelles was investigated using dynamic light scattering. Small‐angle neutron scattering with contrast matching allowed us to quantify the core‐shell structure of the micelles as well as their correlations as a function of temperature.
The Localization Model of Rubber Elasticity
Authors: Douglas Jack F. 
Published: June 2010

AbstractWhile the unusual elastic properties of rubbery polymer materials have been studied for literally centuries, a quantitative theoretical description of these properties in terms of molecular structural parameters remains a challenging task. Classical network elasticity theories are based on the concept of flexible volumeless network chains fixed into a network in which there are no excluded volume, or even topological, interactions between the chains and where the chains explore accessible configurations by Brownian motion. In this type of model, the elasticity of the deformed network derives from the entropic changes in this idealized network arising from a deformation of the network junction positions. The shortcoming of this approach is clear from the observation that unswollen rubbery materials are nearly incompressible, reflecting the existence of strong intermolecular interactions that restrict the polymer chains to an exploration of their local molecular environments. The imposition of a deformation of these solid rubbery materials then necessitates a consideration of how local molecular packing constraints become modified under deformation and the impact of these changes on the macroscopic elasticity of the material as a whole. Many researchers have struggled with this difficult problem, but we focus on the simple ‘localization model’ of rubber elasticity introduced by Gaylord and Douglas (GD), which provides an attractive and mathematically simple minimal model for the network elasticity of rubbers having strong intermolecular interactions in the dense polymer state. GD assume that the network chain segments are localized at the network junctions, as in classical elasticity theory, but they also consider the chains to be localized along their contours by a local harmonic potential arising from inter‐particle packing interactions, as in atoms in a simple harmonic crystal. This is the familiar Edwards‐De Gennes ‘tube’ model of polymers in the condensed state. The existence of the tube means that the entropy of the network chains is reduced relative to chains without this constraint, but the crucial problem is how this entropy change becomes modified as the material becomes deformed. GD approach this problem by first observing that both the volume of the material and the network chains are essentially invariant under deformation so they require that the dimensions of the confining tube to also be a deformation invariant where this constraint is applied at a segmental level. The properties of the resulting ‘localization model’ of elasticity of dry and swollen rubbers are summarized and some extensions of the model to describe chain finite extensibility and stiff polymer networks are briefly summarized.