bluuebunny/crossref_metadata_2025_split huggingface dataset:
Neutron and X‐ray Diffraction and Spectroscopic Investigations of Intramolecular [CH⋅⋅⋅FC] Contacts in Post‐Metallocene Polyolefin Catalysts: Modeling Weak Attractive Polymer–Ligand Interactions
Authors: Chan Michael C. W. , Kui Steven C. F. , Cole Jacqueline M. , McIntyre Garry J. , Matsui Shigekazu , Zhu Nianyong , Tam Ka‐Ho 
Published: December 2005

AbstractA family of Group 4 post‐metallocene catalysts, supported by fluorine‐functionalized tridentate ligands with the fluorine substituent in the locality of the metal center, is described. For the first time, the contentious CH⋅⋅⋅FC interaction has been characterized by a neutron diffraction study, which has allowed the position of the hydrogen atoms to be accurately determined. The nature of the weak intramolecular CH⋅⋅⋅FC contacts in these complexes in solution and the solid state was probed by using multinuclear NMR spectroscopy in tandem with neutron and X‐ray crystallography. Evidence is presented to demonstrate that the spectroscopic CH⋅⋅⋅FC coupling occurs “through‐space” rather than “through‐bond” or by M⋅⋅⋅F coordination. The titanium catalysts exhibit excellent activities and high co‐monomer incorporation in olefin polymerization. The observed intramolecular CH⋅⋅⋅FC interactions are important with regards to potential applications in polyolefin catalysis because they substantiate the proposed ortho‐F⋅⋅⋅H(β) ligand–(polymer chain) contacts derived from DFT calculations for the remarkable fluorinated phenoxyimine Group 4 catalysts. Compared with agostic and co‐catalyst⋅⋅⋅metal contacts, weak attractive noncovalent interactions between a polymer chain and a judiciously designed “active” ligand is a new concept in polyolefin catalysis.
Cutaneous melanoma in postmenopausal women after nonmelanoma skin carcinoma
Authors: Rosenberg Carol A. , Khandekar Janardan , Greenland Philip , Rodabough Rebecca J. , McTiernan Anne 
Published: December 2005

AbstractBACKGROUNDAn elevated risk for cutaneous melanoma has been reported in individuals with nonmelanoma skin carcinoma (NMSC), but to the authors' knowledge, this association has not been prospectively studied in a large, multigeographic population of postmenopausal women.METHODSThe association between NMSC and the incidence of cutaneous melanoma was assessed in the Women's Health Initiative Observational Study involving 67,030 non‐Hispanic white postmenopausal women ages 50–79 years and who were free of prior other cancers at baseline. Cancer history, demographics, and previous and current risk exposures were determined by questionnaires at baseline and follow‐up. Participants' reports of incident cutaneous melanoma collected annually were confirmed by physician review of medical records. Cox proportional hazards analyses were used to assess the relation of prior NMSC with incident cutaneous melanoma.RESULTSIn age‐adjusted analysis, women with a history of NMSC but no other malignancy (n = 5552) were found to be 2.41 times more likely to develop cutaneous melanoma over a mean 6.5 years compared with women who had no history of NMSC (95% confidence interval [95% CI], 1.82–3.20). In a multivariate analysis, women with a history of NMSC and no other cancer history at baseline were 1.70 times more likely to develop cutaneous melanoma compared with women without NMSC (95% CI, 1.18–2.44).CONCLUSIONThe results of the current study provide evidence and further defines the magnitude of increased risk for cutaneous melanoma in postmenopausal non‐Hispanic white women with a history of NMSC. Cancer 2006. © 2005 American Cancer Society.
Single‐Molecule Spectroscopy of Uniaxially Oriented Terrylene in Polyethylene
Authors: Butter Jacqueline Y. P. , Crenshaw Brent R. , Weder Christoph , Hecht Bert 
Published: December 2005

AbstractSingle terrylene molecules doped into linear low‐density polyethylene can be oriented by tensile deformation of the matrix. In measurements on ensembles at ambient and on single terrylene molecules at cryogenic temperature, strong orientation along the stretching direction was observed by polarization‐resolved confocal microscopy. At cryogenic temperatures narrow and spectrally stable zero‐phonon lines were found. The low saturation intensity of 0.07 W cm−2 is consistent with an uniaxial orientation of terrylene in the sample plane.
Structure and Dynamics of Water Confined in Dimethyl Sulfoxide
Authors: Wulf A. , Ludwig Ralf 
Published: December 2005

AbstractWe study the structure and dynamics of hydrogen‐bonded complexes of H2O/D2O and dimethyl sulfoxide (DMSO) by infrared spectroscopy, NMR spectroscopy and ab initio calculations. We find that single water molecules occur in two configurations. For one half of the water monomers both OH/OD groups form strong hydrogen bonds to DMSO molecules, whereas for the other half only one of the two OH/OD groups is hydrogen‐bonded to a solvent molecule. The H‐bond strength between water and DMSO is in the order of that in bulk water. NMR deuteron relaxation rates and calculated deuteron quadrupole coupling constants yield rotational correlation times of water. The molecular reorientation of water monomers in DMSO is two‐and‐a‐half times slower than in bulk water. This result can be explained by local structure behavior.
Sol–Gel Template Synthesis and Photoluminescence of n‐ and p‐Type Semiconductor Oxide Nanowires
Authors: Cao Huaqiang , Qiu Xianqing , Liang Yu , Zhang Lei , Zhao Meijuan , Zhu Qiming 
Published: December 2005

AbstractA sol–gel template technique has been put forward to synthesize single‐crystalline semiconductor oxide nanowires, such as n‐type SnO2 and p‐type NiO. Scanning electron microscopy and transmission electron microscopy observations show that the oxide nanowires are single‐crystal with average diameters in the range of 100–300 nm and lengths of over 10μm. Photoluminescence (PL) spectra show a PL emission peak at 401 nm for n‐type semiconductor SnO2, and a PL emission at 407 nm for p‐type semiconductor NiO nanowires, respectively. Correspondingly, the observed violet‐light emission at room temperature is attributed to near‐band‐edge emission for SnO2 nanowires and the 3d74s→3d8transition of Ni2+for NiO nanowires.
Synthesis of Thioacetate‐Functionalized Cobalt(II) Porphyrins and Their Immobilization on Gold Surface – Characterization by X‐ray Photoelectron Spectroscopy
Authors: Éll Alida H. , Csjernyik Gábor , Slagt Vincent F. , Bäckvall Jan‐E. , Berner Simon , Puglia Carla , Ledung Greger , Oscarsson Sven 
Published: December 2005

AbstractCobalt tetraarylporphyrins 1‐Co and 2‐Co with thioacetate‐functionalized carbon chains on the aryl groups were synthesized. The cobalt porphyrin 2‐Co was immobilized on a gold surface after deprotection of the S‐acetyl group. The immobilized porphyrin was studied by X‐ray Photoelectron Spectroscopy (XPS) and the results suggest that a complete monolayer of porphyrins is formed. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Photochemical and Thermal cis/trans Isomerization of Cyclic and Noncyclic Azobenzene Dimers: Effect of a Cyclic Structure on Isomerization
Authors: Norikane Yasuo , Tamaoki Nobuyuki 
Published: December 2005

AbstractThe effect of ring strain on the photochemical and thermal isomerization of azobenzene dimers was investigated by comparison of macrocyclic (1) and noncyclic (2) azobenzene dimers. The macrocycle 1 comprises two azobenzene moieties connected at their meta positions through two methylene linkers, whereas the noncyclic dimer 2 has only one methylene linker bridging two azobenzenes at the meta positions. Upon irradiation of 1 or 2 with UV light, each (E/E) (trans/trans) isomer exhibited a stepwise photoisomerization to give the corresponding (E/Z) (trans/cis) isomer, followed by isomerization to yield the (Z/Z) (cis/cis) isomer. Quantum yields for the isomerization indicated that the photochemical isomerizations of 1 were altered by its cyclic structure. The effect on the photochemical isomerization process can be explained in terms of the ring strain, causing shifts in the absorption spectra of the azobenzene chromophore and perturbations in molecular motion in the excited state. Thermal (Z) → (E) isomerization was observed in each 1 and 2, taking place in stepwise manner as (Z/Z) → (E/Z) → (E/E). The cyclic structure gave higher activation barriers (Ea and ΔH‡) and activation entropies (ΔS‡). HF/6‐31G** calculations were carried out for 1 and 2 in their ground electronic states in order to estimate the ring strain of each isomer of 1. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Condensed Emodin Derivatives and Their Applicability for the Synthesis of a Fused Heterocyclic Hypericin Derivative
Authors: Waser Mario , Falk Heinz 
Published: December 2005

AbstractInvestigations on the bifunctionalization of emodin at C(6) and C(7) with respect to the synthesis of a new class of fused heterocyclic hypericin derivatives were undertaken. The synthesis of such complex anthraquinone derivatives is possible by applying a Marschalk‐type reaction with emodin‐6‐carbaldehyde as the key step. The newly synthesized pyridazinone‐fused hypericin derivative possesses a satisfying bathochromically shifted absorption maximum making it a promising candidate for further investigations concerning a possible application in photodynamic therapy. Furthermore, the herein described strategy for the bifunctionalization of emodin provides a novel route for the synthesis of anthraquinone derivatives that are difficult to obtain by other methods.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
A Diazonium Salt‐Based Ionic Liquid for Solvent‐Free Modification of Carbon
Authors: Liang Chengdu , Huang Jing‐Fang , Li Zuojiang , Luo Huimin , Dai Sheng 
Published: December 2005

AbstractA novel ionic liquid that consists of p‐butylbenzenediazonium ions and bis(trifluoromethanesulfonyl)amidates (Tf2N–) has been synthesized as a task‐specific ionic liquid for the solvent‐free modification of carbon materials. The use of anions Tf2N– is the key to rendering the hydrophobicity, low liquidus temperature, and ionicity to this novel molten salt. This diazonium salt has a melting point of 7.2 °C and a moderate electric conductivity of 527 μs/cm at 25 °C. The thermal stability of this diazonium ionic liquid has been investigated by high‐resolution thermogravimetric analysis (HRTGA). The compound is stable up to about 90 °C in nitrogen, which is only 10 °C less than its solid tetrafluoroborate counterpart. The modification of carbon materials has been carried out through both thermal and electrochemical activations of diazonium ions to generate free radical intermediates without the use of any solvent. The surface‐coverage loadings of 3.38 μmol/m2 and 6.07 μmol/m2 for covalently attached organic functionalities have been achieved by the thermally induced functionalization and electrochemically assisted reaction, respectively. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
A sequential Monte Carlo approach for marine ecological prediction
Authors: Dowd Michael 
Published: December 2005

AbstractThis study considers the problem of marine ecological prediction in the context of online estimation and forecasting. Process oriented dynamic ecosystem models are combined with marine observations. The nonlinear, nonGaussian state space model provides the statistical framework. The associated filtering (nowcasting) and prediction (forecasting) problems are addressed via sequential Monte Carlo methods, in this instance a sequential importance resampler combined with Metropolis‐Hastings MCMC. The specific focus is on a prototypical marine ecosystem model comprised of four interacting populations (phytoplankton, zooplankton, nutrients and detritus; PZND) whose co‐evolution is described by system of coupled nonlinear differential equations. Stochastic environmental variation is introduced through a stochastic growth parameter, as well as through dynamical noise in the state evolution equations. The dynamic behaviour of this stochastic ecosystem model is complex: it regularly transitions through a Hopf bifurcation and exhibits episodic blooms of variable magnitude and duration. The model is applied to a case with weak seasonality, that is the oceanic mixed layer in the eastern equatorial Pacific. A partially observed state is considered comprised of a five year satellite (SeaWiFS) derived time series of ocean phytoplankton concentration at 12°N 95°W. Filtering estimates for the ecosystem state and a dynamic parameter were obtained using the sequential Monte Carlo approach. These showed predictor‐corrector behaviour at observation times, including abrupt shifts in the median level after forecasts over measurement void. A corresponding variance (also skewness and kurtosis) growth and subsequent collapse was also seen. Forecasting experiments indicate some negative bias, and suggest there is predictive skill for forecasts out to 10–15 days. Copyright © 2005 John Wiley & Sons, Ltd.
Nonparametric prediction intervals for the future rainfall records
Authors: Raqab Mohammad Z. 
Published: December 2005

AbstractPrediction of records plays an important role in the environmental applications, especially, prediction of rainfall extremes, highest water levels, sea surface, and air record temperatures. In this paper, based on the observed records drawn from a sequence sample of independent and identically random variables, we develop prediction intervals as well as prediction upper and lower bounds for records from another independent sequence. We extend the prediction problem to include prediction regions for joint upper records from a future sequence sample. The Bonferouni's inequality is used to choose appropriate prediction coefficients for the joint prediction. A real data set representing the records of the annual (January 1–December 31) rainfall at Los Angeles Civic Center is addressed to illustrate the proposed prediction procedures in the environmental applications. Copyright © 2005 John Wiley & Sons, Ltd.
Biostratigraphy, microfacies and depositional environments of upper Viséan limestones from the Burren region, County Clare, Ireland
Authors: Gallagher S.J. , MacDermot C.V. , Somerville I.D. , Pracht M. , Sleeman A.G. 
Published: December 2005

AbstractThe Burren region in western Ireland contains an almost continuous record of Viséan (Middle Mississippian) carbonate deposition extending from Chadian to Brigantian times, represented by three formations: the Chadian to Holkerian Tubber Formation, the Asbian Burren Formation and the Brigantian Slievenaglasha Formation. The upper Viséan (Holkerian–Brigantian) platform carbonate succession of the Burren can be subdivided into six distinct depositional units outlined below. (1) An Holkerian to lower Asbian unit of skeletal peloidal and bryozoan bedded limestone. (2) Lower Asbian unit of massive light grey Koninckopora‐rich limestone, representing a shallower marine facies. (3) Upper Asbian terraced limestone unit with minor shallowing‐upward cycles of poorly bedded Kamaenella‐rich limestone with shell bands and palaeokarst features. This unit is very similar to other cyclic sequences of late Asbian age in southern Ireland and western Europe, suggesting a glacio‐eustatic origin for this fourth‐order cyclicity. (4) Lower Brigantian unit with cyclic alternations of crinoidal/bryozoan limestone and peloidal limestone with coral thickets. These cycles lack evidence of subaerial exposure. (5) Lower Brigantian bedded cherty dark grey limestone unit, deposited during the maximum transgressive phase of the Brigantian. (6) Lower to upper Brigantian unit mostly comprising cyclic bryozoan/crinoidal cherty limestone. In most areas this youngest unit is truncated and unconformably overlain by Serpukhovian siliciclastic rocks. Deepening enhanced by platform‐wide subsidence strongly influenced later Brigantian cycle development in Ireland, but localized rapid shallowing led to emergence at the end of the Brigantian.A Cf5 Zone (Holkerian) assemblage of microfossils is recorded from the Tubber Formation at Black Head, but in the Ballard Bridge section the top of the formation has Cf6 Zone (Asbian) foraminiferans. A typical upper Asbian Rugose Coral Assemblage G near the top of the Burren Formation is replaced by a lower Brigantian Rugose Coral Assemblage H in the Slievenaglasha Formation. A similar change in the foraminiferans and calcareous algae at this Asbian–Brigantian formation boundary is recognized by the presence of upper Asbian Cf6γ Subzone taxa in the Burren Formation including Cribrostomum lecomptei, Koskinobigenerina sp., Bradyina rotula and Howchinia bradyana, and in the Slievenaglasha Formation abundant Asteroarchaediscus spp., Neoarchaediscus spp. and Fasciella crustosa of the Brigantian Cf6δ Subzone. The uppermost beds of the Slievenaglasha Formation contain a rare and unusual foraminiferal assemblage containing evolved archaediscids close to tenuis stage indicating a late Brigantian age. Copyright © 2006 John Wiley & Sons, Ltd.
Estimating dynamic equilibrium economies: linear versus nonlinear likelihood
Authors: Fernández‐Villaverde Jesús , Rubio‐Ramírez Juan F. 
Published: December 2005

AbstractThis paper compares two methods for undertaking likelihood‐based inference in dynamic equilibrium economies: a sequential Monte Carlo filter and the Kalman filter. The sequential Monte Carlo filter exploits the nonlinear structure of the economy and evaluates the likelihood function of the model by simulation methods. The Kalman filter estimates a linearization of the economy around the steady state. We report two main results. First, both for simulated and for real data, the sequential Monte Carlo filter delivers a substantially better fit of the model to the data as measured by the marginal likelihood. This is true even for a nearly linear case. Second, the differences in terms of point estimates, although relatively small in absolute values, have important effects on the moments of the model. We conclude that the nonlinear filter is a superior procedure for taking models to the data. Copyright © 2005 John Wiley & Sons, Ltd.
The cross‐Euler equation approach to intertemporal substitution in import demand
Authors: Nishiyama Shin‐Ichi 
Published: December 2005

AbstractThis paper addresses the empirical dilemma in identifying and estimating the parameters governing the intertemporal elasticity of substitution (IES) for import demand. We propose a new concept, the cross‐Euler equation, for overcoming this empirical dilemma. IES parameters are estimated by exploiting the cointegrating restriction implied by the cross‐Euler equation. Further, by comparing the IES estimates from the cross‐Euler equation to those from the standard Euler equation, we test the hypothesis whether import demand is affected by nuisance factors. Using the US data, we found imported goods consumption to be robust against nuisance factors, but not for domestic goods. Copyright © 2005 John Wiley & Sons, Ltd.
Effect of storage upon material properties of lyophilized porcine extracellular matrix derived from the urinary bladder
Authors: Freytes Donald O. , Tullius Robert S. , Badylak Stephen F. 
Published: December 2005

AbstractXenogeneic extracellular matrices (ECMs) have been developed as off‐the‐shelf biologic scaffolds that have been effectively used in preclinical and clinical applications for tissue reconstruction. Such materials must be suitable for terminal sterilization and capable of storage for extended periods of time without significant changes in material properties and bioactivity. Material properties of interest for ECM scaffolds include hydrostatic permeability index (PI), uniaxial maximum load and elongation, maximum tangential stiffness (MTS), suture retention strength (SRS), and ball‐burst strength (BBS). The present study evaluated these material properties for lyophilized forms of an ECM scaffold derived from the porcine urinary bladder, termed urinary bladder matrix (UBM), that was terminally sterilized by e‐beam irradiation at 22 kGy and stored at room temperature (RT; 20–24°C) or refrigerated temperature (REFT; 4–8°C) for up to 12 months. UBM devices showed no change in SRS, BBS, and hydrostatic PI after the evaluation period. Lyophilized devices stored at RT showed an increase in maximum load and MTS while devices stored at REFT showed an increase in maximum elongation after 1 year of storage (p < 0.05). These results indicate that structural changes in the UBM device may slowly occur as a function of prolonged storage and storage temperature. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2006
PGF2α increases FGF‐2 and FGFR2 trafficking in Py1a rat osteoblasts via clathrin independent and importin β dependent pathway
Authors: Marchetti Luigi , Sabbieti Maria G. , Agas Dimitrios , Menghi Maura , Materazzi Giovanni , Menghi Giovanna , Hurley Marja M. 
Published: December 2005

AbstractPrevious studies showed that prostaglandin F2α (PGF2α) stimulated fibroblast growth factor‐2 (FGF‐2) and fibroblast growth factor receptor 2 (FGFR2) cytosolic and nuclear accumulation, however, the endocytic pathway has not been elucidated. This study demonstrates that although PGF2α increased the formation of clathrin‐coated structures in Py1a rat osteoblasts, they were not involved in FGF‐2 and FGFR2 trafficking. PGF2α increased binding of FGF‐2 and FGFR2 and co‐localization of reactive sites in addition to nuclear translocation at the nuclear pore complex level. FGF‐2 and FGFR2 were in close spatial correlation with importin β, further supporting nuclear import of the FGF‐2/FGFR2 complex. Immunogold and immunofluorescence techniques as well as Western blotting demonstrated increased importin β protein labeling in response to PGF2α. Similar to PGF2α, phorbol 12‐myristate 13‐acetate (PMA) also increased importin β protein. These data strongly suggest that prostaglandins may regulate osteoblast metabolism via FGF‐2/FGFR2/importin β nuclear trafficking. J. Cell. Biochem. 97: 1379–1392, 2006. © 2005 Wiley‐Liss, Inc.
Light‐induced exocytosis in cell development and differentiation
Authors: Henkel Andreas W. , Upmann Irene , Bartl Christina R. , Bönsch Dominikus , Reichardt Cornelia , Maler Juan Manuel , Nürnberger Michael , Umstätter Richard , Reulbach Udo , Kornhuber Johannes , Wiltfang Jens 
Published: December 2005

AbstractCalcium‐dependent exocytosis of fluorescently labeled single secretory vesicles in PC12 cells and primary embryonic telencephalon cells can be triggered by illumination with visible light and imaged by TIRF or epifluorescence microscopy. Opsin 3 was identified by quantitative PCR expression analysis as the putative light receptor molecule for light‐induced exocytosis. In primary chicken telencephalon cells, light‐induced exocytosis is restricted to a specific period during embryonic development, and involves fusion of rather large vesicles. Strictly calcium‐dependent exocytosis starts after a delay of a few seconds of illumination and lasts for up to 2 min. We analyzed the frequency, time course and spatial distribution of exocytotic events. Exocytosis in PC12 cells and telencephalon cells occurs at the periphery or the interface between dividing cells, and the duration of single secretion events varies considerably. Our observation strongly supports the idea that light induced exocytosis is most likely a mechanism for building plasma membrane during differentiation, development and proliferation rather than for calcium‐dependent neurotransmitter release. J. Cell. Biochem. 97: 1393–1406, 2006. © 2005 Wiley‐Liss, Inc.