bluuebunny/crossref_metadata_2025_split huggingface dataset:
Thin Films of Insoluble Poly(Oligothienylene vinylenes) Prepared by Chemical Vapor Deposition Polymerization
Authors: Joo S.‐H. , Lee C.‐Y. , Park D. , Joo J. , Jin J.‐I. 
Published: August 2007

AbstractA series of poly(oligothienylene vinylenes) (PTmVs,m = 2–4) with a varying number of consecutively bound thienylene rings are successfully prepared in thin films by chemical vapor deposition polymerization (CVDP) using the corresponding bis(halomethyl)thiophenes as starting materials. The chemical and electronic structures are studied spectroscopically and also by cyclic voltammetry. Top‐gate field‐effect transistors are fabricated by two consecutive CVDP cycles of PTmV and poly(p‐xylylene) followed by the deposition of a Au gate electrode. In the case of a PT3V active layer, a field‐effect mobility value of 0.5 × 10–4 cm2 V–1 s–1is obtained.
Template‐Synthesized Protein Macroporous Biofilms: Conformational Related Direct Electron Transfer
Authors: Song Y.‐Y. , Jia W.‐Z. , Yang C. , Xia X.‐H. 
Published: August 2007

AbstractWe report on the synthesis of three‐dimensionally ordered structure (3D) of macroporous cytochrome c (cyt‐c) biofilms by using the inverted colloidal polystyrene crystal template technique and Triton X‐100 as entrapping matrix. Electrochemical impedance spectroscopic (EIS) measurements reveal that the immobilized cyt‐c molecules exhibit fast interfacial electron‐communication rate. We found that the orientation of the cyt‐c molecules entrapped in the 3D macroporous structure was determined by the interfacial electric field. Higher interfacial electric field limits the reorientational flexibility of the entrapped cyt‐c molecules, resulting in lower intermolecular electron‐communication rate constant (k°). Therefore, the highest intermolecular electron‐communication rate constant can only be obtained at potentials approaching to the potential of zero charge of the gold electrode, since k° is mainly determined by the molecular orientation in the biofilm. In addition, the prepared biofilms with enhanced functional density could find potential application in the bioelectronic sensing system.
Cover Picture: Low‐Work‐Function Surface Formed by Solution‐Processed and Thermally Deposited Nanoscale Layers of Cesium Carbonate (Adv. Funct. Mater. 12/2007)
Authors: Huang J. , Xu Z. , Yang Y. 
Published: August 2007

AbstractThe cover shows the structure of an efficient polymer light emitting diode (PLED) and its energy diagram at the interface between aluminum (Al) and a Cs2CO3 interfacial layer. It reveals the origin of enhanced electron injection from the Al electrode due to the low work function of a thermally evaporated Cs2CO3 layer, as reported on p. 1966 by Jinsong Huang, Zhen Xu, and Yang Yang. Pictures of the white‐ and red‐emitting PLEDs are also shown.Nanostructured layers of Cs2CO3 are shown to function very effectively as cathodes in organic electronic devices because of their good electron‐injection capabilities. Here, we report a comprehensive study of the origin of the low work function of nanostructured layers of Cs2CO3 prepared by solution deposition and thermal evaporation. The nanoscale Cs2CO3 layers are probed by various characterization methods including current–voltage (I–V) measurements, photovoltaic studies, X‐ray photoelectron spectroscopy (XPS), UV photoelectron spectroscopy (UPS), and impedance spectroscopy. It is found that thermally evaporated Cs2CO3 decomposes into CsO2 and cesium suboxides. The cesium suboxides dope CsO2, yielding a heavily doped n‐type semiconductor with an intrinsically low work function. As a result, devices fabricated using thermally evaporated Cs2CO3 are relatively insensitive to the choice of the cathode metal. The reaction of thermally evaporated Cs2CO3 with Al can further reduce the work function to 2.1 eV by forming an Al–O–Cs complex. Solution‐processed Cs2CO3 also reduces the work function of Au substrates from 5.1 to 3.5 eV. However, devices prepared using solution‐processed Cs2CO3 exhibit high efficiency only if a reactive metal such as Al or Ca is used as the cathode metal. A strong chemical reaction occurs between spin‐coated Cs2CO3 and thermally evaporated Al. An Al–O—Cs complex is formed as a result of this chemical reaction at the interface, and this layer significantly reduces the work function of the cathode. Finally, impedance spectroscopy results prove that this layer is highly conductive.
Imaging of amyloid burden and distribution in cerebral amyloid angiopathy
Authors: Johnson Keith A. , Gregas Matt , Becker John A. , Kinnecom Catherine , Salat David H. , Moran Erin K. , Smith Erin E. , Rosand Jonathan , Rentz Dorene M. , Klunk William E. , Mathis Chester A. , Price Julie C. , DeKosky Steven T. , Fischman Alan J. , Greenberg Steven M. 
Published: August 2007

AbstractObjectiveCerebrovascular deposition of β‐amyloid (cerebral amyloid angiopathy [CAA]) is a major cause of hemorrhagic stroke and a likely contributor to vascular cognitive impairment. We evaluated positron emission tomographic imaging with the β‐amyloid–binding compound Pittsburgh Compound B (PiB) as a potential noninvasive method for detection of CAA. We hypothesized that amyloid deposition would be observed with PiB in CAA, and based on the occipital predilection of CAA pathology and associated hemorrhages, that specific PiB retention would be disproportionately greater in occipital lobes.MethodsWe compared specific cortical PiB retention in 6 nondemented subjects diagnosed with probable CAA with 15 healthy control subjects and 9 patients with probable Alzheimer's disease (AD).ResultsAll CAA and AD subjects were PiB‐positive, both by distribution volume ratio measurements and by visual inspection of positron emission tomographic images. Global cortical PiB retention was significantly increased in CAA (distribution volume ratio 1.18 ± 0.06) relative to healthy control subjects (1.04 ± 0.10; p = 0.0009), but was lower in CAA than in AD subjects (1.41 ± 0.17; p = 0.002). The occipital‐to‐global PiB ratio, however, was significantly greater in CAA than in AD subjects (0.99 ± 0.07 vs 0.86 ± 0.05; p = 0.003).InterpretationWe conclude that PiB‐positron emission tomography can detect cerebrovascular β‐amyloid and may serve as a method for identifying the extent of CAA in living subjects. Ann Neurol 2007
Tau and α‐synuclein in susceptibility to, and dementia in, Parkinson's disease
Authors: Goris An , Williams‐Gray Caroline H. , Clark Graeme R. , Foltynie Thomas , Lewis Simon J. G. , Brown Joanne , Ban Maria , Spillantini Maria G. , Compston Alastair , Burn David J. , Chinnery Patrick F. , Barker Roger A. , Sawcer Stephen J. 
Published: August 2007

AbstractObjectiveParkinson's disease (PD) is a neurodegenerative condition that typically presents as a movement disorder but is known to be associated with variable degrees of cognitive impairment including dementia. We investigated the genetic basis of susceptibility to and cognitive heterogeneity of this disease.MethodsIn 659 PD patients, 109 of which were followed up for 3.5 years from diagnosis, and 2,176 control subjects, we studied candidate genes involved in protein aggregation and inclusion body formation, the pathological hallmark of parkinsonism: microtubule‐associated protein tau (MAPT), glycogen synthase kinase‐3β (GSK3B), and α‐synuclein (SNCA).ResultsWe observed that cognitive decline and the development of PD dementia are strongly associated (p = 10−4) with the inversion polymorphism containing MAPT. We also found a novel synergistic interaction between the MAPT inversion polymorphism and the single nucleotide polymorphism rs356219 from the 3′ region of SNCA. In our data, carrying a risk genotype at either of these loci marginally increases the risk for development of PD, whereas carrying the combination of risk genotypes at both loci approximately doubles the risk for development of the disease (p = 3 × 10−6).InterpretationOur data support the hypothesis that tau and α‐synuclein are involved in shared or converging pathways in the pathogenesis of PD, and suggest that the tau inversion influences the development of cognitive impairment and dementia in patients with idiopathic PD. These findings have potentially important implications for understanding the interface between tau and α‐synuclein pathways in neurodegenerative disorders and for unraveling the biological basis for cognitive impairment and dementia in PD. Ann Neurol 2007
Preparation of size‐controlled In2O3 nanoparticles
Authors: Zhu Peng , Wu Weiya , Zhou Jianping , Zhang Wu 
Published: August 2007

AbstractHighly crystalline and monodisperse In2O3 nanoparticles were successfully prepared by thermal decomposition of In(dipy)3Cl3·2H2O in oleylamine and oleic acid under inert atmosphere. The size of In2O3 nanoparticles could be readily tuned from 10–15 nm to 40–50 nm, depending on the molar ratio of precursor to combined solvent in the reaction system. As‐synthesized In2O3 nanoparticles have a center‐body cubic structure as characterized by powder X‐ray diffraction and selected‐area electron diffraction. Transmission electron microscopy images showed that In2O3 nanoparticles have a narrow size distribution. A relatively strongly PL peak centered at 378 nm could be clearly seen when 10–15 nm In2O3 nanoparticles redispersed in cyclohexane were excited at 275 nm at room temperature. Copyright © 2007 John Wiley & Sons, Ltd.
Estimation and econometric tests under price and output uncertainties
Authors: Alghalith Moawia 
Published: August 2007

AbstractWe extend the existing estimation methods to allow empirical estimation and hypothesis testing under simultaneous price and output uncertainty. Our approach modifies and expands the use of duality theory. Furthermore, our approach does not require the specification or estimation of the production/cost function. In addition, our approach does not require the assumption of the statistical independence between price and output. Copyright © 2007 John Wiley & Sons, Ltd.
A look at US–Brazil ethanol trade and policy
Authors: Gallagher Paul W. 
Published: August 2007

AbstractBrazil and the USA are experiencing an “ethanol investment boom”. Agriculture in both countries is being reorganized to boost biomass production, but duties and tariffs may fi nally dictate the way the nations adjust to increasing demand, says Paul W. Gallagher. © 2007 Society of Chemical Industry and John Wiley & Sons, Ltd
The complex p25/Cdk5 kinase in neurofibrillary degeneration and neuronal death: The missing link to cell cycle
Authors: Hamdane Malika , Buée Luc 
Published: August 2007

AbstractEmergence of the cell cycle hypothesis in neurodegenerative disease comes from the numerous lines of evidence showing a tight link between “cell cycle‐like reactivation” and neuronal death. Terminally differentiated neurons remain in G0 phase and display, compared to proliferating cells, an opposite regulation pattern of cell cycle markers in that most of the key activators and inhibitors are respectively down‐ and up‐regulated. It has been clearly established that any experimental attempt to force terminally differentiated neurons to divide ultimately leads to their death. Conversely, cell cycle blockade in experimental models of neuronal death is able to rescue neurons. Hence, cell cycle deregulation is certainly among mechanisms governing neuronal death. However, many questions remain unresolved, especially those related to which molecular mechanisms trigger cell cycle deregulation and how this deregulation leads to cell death. In the present review, we focus on neurodegeneration in Alzheimer's disease and discuss the cell cycle deregulation related to this neurodegenerative pathology. Finally, we emphasize the role of p25/Cdk5 kinase complex in this pathological process through retinoblastoma protein phosphorylation and derepression of E2F‐responsive genes and other actors such as cdc2, cyclins, and MCM proteins.
Aristolochene Synthase‐Catalyzed Cyclization of 2‐Fluorofarnesyl‐Diphosphate to 2‐Fluorogermacrene A
Authors: Miller David J. , Yu Fanglei , Allemann Rudolf K. 
Published: August 2007

AbstractThe mechanism of the conversion of (E,E)‐farnesyl diphosphate (FPP, 1 a) to aristolochene (6) catalyzed by aristolochene synthase from Penicillium roqueforti has been proposed to proceed through the neutral intermediate germacrene A (4 a). However, much of the experimental evidence is also in agreement with a mechanism in which germacrene A is not an intermediate in the predominant mechanism that leads to the formation of aristolochene, but rather an off‐pathway product that is formed in a side reaction. Hence, to elucidate the mechanism of FPP cyclisation the substrate analogue 2‐fluoroFPP (1 b) was synthesized, and upon incubation with aristolochene synthase was converted to a single pentane extractable product according to GC‐MS analysis. On the basis of NMR analyses this product was identified as 2‐fluorogermacrene A (4 b). Variable temperature 1H NMR spectroscopy indicated the existence of two conformers of 4 b that were in slow exchange at −60 °C, while at 90 °C the two isomers gave rise to averaged NMR signals. In the major isomer (∼75 %) the methyl groups on C3 and C7 were most likely in the down–down orientation as had been observed for other (E,E)‐germacranes. This work suggests that after an initial concerted cyclisation of FPP to germacryl cation deprotonation leads to the formation of germacrene A, and provides compelling evidence that germacrene A is indeed an on‐pathway product of catalysis by aristolochene synthase.
ChemoAC: its contribution to the advancement of Chemometrics
Authors: Vandeginste BGM , Smeyers‐Verbeke J. 
Published: August 2007

AbstractThe impact of ChemoAC—a consortium of industry and the laboratory headed by Professor Massart at the Vrije Universiteit Brussel—on the advancement of Chemometrics is discussed by reviewing its 50 most important chemometric papers. Copyright © 2007 John Wiley & Sons, Ltd.
Focused hierarchical design of peptide libraries—follow the lead
Authors: Muthas Daniel , Lek Per M. , Nurbo Johanna , Karlén Anders , Lundstedt Torbjörn 
Published: August 2007

AbstractA novel design strategy based on the hierarchical design of experiments (HDoE) method named focused hierarchical design of experiments (FHDoE) is presented. FHDoE combine two design layers and use focused substitutions to increase the probability of obtaining active peptides when designing libraries through a selection of compounds biased towards a lead structure. Increasing the number of peptides with measurable activity will increase the information gained and the likelihood of constructing good quantitative structure–activity relationship (QSAR) models. The utility of the novel design method is verified using two different approaches. First, a library designed with the novel FHDoE method was compared with libraries generated from classical positional scanning techniques (e.g., alanine scan) as well as with general and centered minimum analog peptide sets (MAPS) libraries by using an example found in the literature. Secondly, the same design strategies were applied to a dataset of 58 angiotensin converting enzyme (ACE) dipeptide inhibitors. QSAR models were generated from designed sublibraries and the activities of the remaining compounds were predicted. These two examples show that the use of FHDoE renders peptide libraries close in physicochemical space to the native ligand, yielding a more thorough screening of the area of interest as compared to the classical positional scans and fractional factorial design (FFD). It is also shown that an FHDoE library of six dipeptides could produce a QSAR model that better described the requisites of high activity ACE inhibitors than could QSAR models built from either a nine‐dipeptide library designed with MAPS or a 58‐dipeptide library. Copyright © 2007 John Wiley & Sons, Ltd.
Modelling crack propagation in structures: Comparison of numerical methods
Authors: Yang Xin‐She , Lees Janet M. , Morley Chris T. 
Published: August 2007

AbstractCrack propagation in concrete structures is a very complicated process, and the distribution of cracks may significantly affect the behaviour of the structures under time‐dependent loading. If enough damage or extensive cracks exist in a structure, strengthening or repair using external carbon fibre‐reinforced polymer (CFRP) reinforcement may be needed. Therefore, an understanding of the influence of the CFRP strengthening system on behaviour is crucial for the proper design of a structural reinforcement strategy. In this paper, we compare three major methods: the discrete crack method, the smeared crack method and the element‐free method. By using these methods to study the fracture pattern of a beam with dapped ends, we can compare the capabilities and efficiencies of the three methods. When modelling the crack formation in reinforced concrete structures, the smeared crack approach gives better results than the discrete model in terms of crack spacing and regularity, however, it does not follow the crack growth well. The element‐free Galerkin method seems to be superior to the other methods in the sense that it deals with the irregular cracks well and is very efficient in saving computing time. The preferred choice of method depends on the type of problem and the solution accuracy required, and this also depends on a certain balance between the accurate tracing of individual cracks and the computing efficiency. In addition, new algorithms are required for the efficient simulations of dynamic crack propagation, especially in the case of pre‐cracked structures strengthened with prestressed CFRPs. Copyright © 2007 John Wiley & Sons, Ltd.
Embryonic cardiomyocyte expression of endothelial genes
Authors: Welikson Robert E. , Kaestner Stefanie , Evans Angela M. , Hauschka Stephen D. 
Published: August 2007

AbstractVertebrate precardiac mesoderm contains cells destined to become cardiomyocyte or endothelial cells. To determine the stability of these phenotypes freshly isolated embryonic day (E) 2.5–E6 chicken hearts were immunostained for myosin heavy chain (MyHC) to identify cardiomyocytes, and von Willebrand factor (vWF) and Flk‐1 to identify endothelial cells. At E2.5–E3, 90% of cells express only MyHC and 6% express only vWF/Flk‐1. However, 2% MyHC+ cells in E2.5–E3 hearts and 0.3% in E4–E6 hearts, also express vWF/Flk‐1; and when cultured 3 days, >40% of the MyHC+ cells express vWF/Flk‐1, but they do not express Vezf1, vascular endothelial cadherin, or Tie2. Thus, only a subset of endothelial genes are induced in cultured cardiomyocytes. While the subsequent developmental fate of embryonic heart cells exhibiting a vWF+/MyHC+ phenotype is unknown, analysis of this phenotype may provide information pertinent to mechanisms of cell phenotype stability, cellular transdifferentiation, and induction of stable cell types from embryonic stem cells. Developmental Dynamics 236:2512–2522, 2007. © 2007 Wiley‐Liss, Inc.
Comorbidity and high‐risk behaviors in treatment‐seeking adolescents with bulimia nervosa
Authors: Fischer Sarah , Grange Daniel le 
Published: August 2007

AbstractObjective:The purpose of this brief report is to describe the comorbid diagnoses and high‐risk behaviors in a sample of adolescents with bulimia nervosa (BN).Method:Eighty adolescents enrolled in a RCT for BN that compared family‐based therapy with individual‐supportive psychotherapy completed the Eating Disorder Examination and the Schedule for Affective Disorder and Schizophrenia for School Age Children (K‐SADS).Results:A total of 62.5% of the sample had a comorbid diagnosis as determined by the K‐SADS. The majority of these presented with a major mood disorder. In addition, 25% of the sample had previously attempted suicide or self‐harmed, 65.8% had consumed alcohol, and 30% had used illegal drugs. Suicidal behavior, drug use, and presence of a comorbid diagnosis were not related to diagnosis (full BN vs. subthreshold BN) or age.Conclusion:Comorbidity and high‐risk health behaviors in adolescents with BN mirror those of adults with BN although not at similar rates. © 2007 by Wiley Periodicals, Inc. Int J Eat Disord 2007
An Efficient Synthesis of (–)‐Posticlure: The Sex Pheromone of Orgyia postica
Authors: Fernandes Rodney A. 
Published: August 2007

AbstractAn efficient multigram synthesis of (–)‐posticlure, the first trans‐epoxide sex pheromone found in Orgyia postica, from diethyl L‐tartrate is described. The synthesis was completed in seven steps and 27 % overall yield. The synthetic strategy features double‐Wittig olefination and a stereoselective one‐pot conversion of diol to epoxide as the key steps. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Flexible routing in a distributed K‐ary tree: the K‐Umbrella
Authors: Sotiriou Athanasios‐Dimitrios , Kalliaras Panagiotis , Mitrou Nikolas 
Published: August 2007

AbstractAs peer‐to‐peer (P2P) applications become more mature and demanding, there is a need for the underlying technologies to provide more adaptive characteristics, according to the application's requirements. In this paper, we present K‐Umbrella, a K‐ary distributed hash table (DHT), which allows us to efficiently route through the use of a fixed‐size routing table. By controlling a number of parameters, our algorithm is able to trade‐off between efficiency, fault‐tolerance and decentralisation according to the application's requirements. Through a detailed analysis of our algorithms and an extensive set of simulations, we will show that our protocol is able to offer an improved alternative to current DHT algorithms. Copyright © 2007 John Wiley & Sons, Ltd.
Stability of some low‐order approximations for the Stokes problem
Authors: Nafa Kamel 
Published: August 2007

AbstractTwo‐level low‐order finite element approximations are considered for the inhomogeneous Stokes equations. The elements introduced are attractive because of their simplicity and computational efficiency. In this paper, the stability of a Q1(h)–Q1(2h) approximation is analysed for general geometries. Using the macroelement technique, we prove the stability condition for both two‐ and three‐dimensional problems. As a result, optimal rates of convergence are found for the velocity and pressure approximations. Numerical results for three test problems are presented. We observe that for the computed examples, the accuracy of the two‐level bilinear approximation is compared favourably with some standard finite elements. Copyright © 2007 John Wiley & Sons, Ltd.