bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis and Self‐Assembly of Functionalized Cyclooctene Block Copolymers via ROMP
Authors: Xie Meiran , Han Huijing , Wang Weizhen , He Xiaohua , Zhang Yiqun
Published: December 2007

A novel block copolymer consisted of MACIT and HCO segments was synthesized via ROMP in the ionic liquid [bmim][PF6] with good control over the polymerization process. The molecular weight of the block copolymer was estimated by 1H NMR, and the molar composition ratio of repeating units in the MACIT block to those in the HCO block was 100:120 (120:120 in feed). The micellar characterization was carried out by DLS, AFM, and TEM. The hydrodynamic diameter of the micelles, measured by DLS, was 129 ± 0.09 nm with a narrow distribution (PDI = 0.034). The TEM image showed spherical micelles.

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A Novel Strategy to Incorporate Carbon Nanotubes into Thermoplastic Matrices
Authors: Pötschke Petra , Pegel Sven , Claes Michael , Bonduel Daniel
Published: December 2007

Multiwalled carbon nanotubes (MWNT) are introduced into thermoplastic matrices (polycarbonate and polyamide) by melt blending using polyethylene (PE) based concentrates with high MWNT loadings (24–44 wt.‐%). MWNT surfaces were treated with a metallocene‐based complex to afford the in‐situ polymerization of ethylene directly from the surface. The resulting concentrates showed excellent MWNT pre‐dispersion. Due to the high interfacial energy between MWNT and PE, the nanotubes migrate into matrix polymers with lower interfacial energies, like polycarbonate and polyamide, and thereby remain in their excellent dispersion state. Thus, electrical percolation is achieved at lower MWNT contents as compared to direct incorporation. For polycarbonate it is shifted from 0.75 to 0.25 wt.‐%.

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Multi‐Sensitive Microgels Filled with Conducting Poly(3,4‐ethylenedioxythiophene) Nanorods
Authors: Hain Jessica , Eckert Franziska , Pich Andrij , Adler Hans‐Juergen
Published: December 2007

In this work we describe the synthesis of multi‐sensitive aqueous microgel particles with incorporated conducting poly(3,4‐ethylenedioxythiophene) (PEDOT) nanorods. We demonstrate that the loaded amount of PEDOT nanorods as well as their morphology can be varied by controlling the reaction conditions such as monomer concentration and alcohol concentration in aqueous phase. Obtained microgels can be stimulated by changes in the environment temperature as well as by the repulsion/attraction forces within polymeric network due to the reversible oxidation/reduction of the conjugated polymer. Microgels with unique properties can be operated in colloidal systems or used as building blocks for the preparation of nanostructured films.

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High Rate Silicification of Peptide‐Polymer Assemblies Toward Composite Nanotapes
Authors: Kessel Stefanie , Börner Hans G.
Published: December 2007

Well‐defined silica composite nanofibers are generated in a silicification process of self‐assembled poly(ethylene oxide)‐peptide nanotapes. Inspired by biological silica morphogenesis processes the nanotapes exhibit strong binding capabilities for silicic acid. Thus, pre‐hydrolyzed tetramethoxysilane could be used as silica precursor. Very low concentrations (270 µM) and short contact times (10 s) are sufficient to form effectively integrated nano‐composite tapes.

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Thermal Stability of Lyocell Solutions: Experimental Results and Modeling Using Cluster Analysis and Partial Least Squares Regression
Authors: Wendler Frank , Kolbe Axel , Kraft Jörg , Einax Jürgen W. , Heinze Thomas
Published: December 2007

A population of 167 samples were monitored using by rheological, calorimetric, chromatographic and spectroscopic methods, which allows a precise description of the thermal behavior. Hierarchical cluster analysis was used to find similarities between groups of samples. Principal components analysis revealed isoperibolic pressure slope, morpholine and N‐methylmorpholine as variables providing most information concerning the thermostability. The onset temperature as the beginning of an exothermicity can be modeled by the combination of detection of amines and aldehydes and subsequent PLS regression.

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Excessive dopamine neuron loss in progressive supranuclear palsy
Authors: Murphy Karen E. , Karaconji Tanya , Hardman Craig D. , Halliday Glenda M.
Published: December 2007

Progressive supranuclear palsy (PSP) and Parkinson's disease (PD) differ in their response to dopaminergic replacement therapies, despite having a similar degree of neuronal degeneration in the dopaminergic substantia nigra. We observed more widespread dopamine neuron loss in the extranigral A10 midbrain cell groups in PSP compared with PD. These cell groups innervate subcortical and cortical regions and may be required for adequate response to levodopa therapy. © 2007 Movement Disorder Society
Goldsinny wrasse (Ctenolabrusrupestris) is an extreme vtgAa‐type pelagophil teleost
Authors: Kolarevic Jelena , Nerland Audun , Nilsen Frank , Finn Roderick Nigel
Published: December 2007

During oocyte maturation in the goldsinny wrasse (Ctenolabrus rupestris) extensive proteolysis of yolk proteins generates a large pool of free amino acids that drive hydration of the pelagic egg. By cloning hepatic vitellogenins (vtg) and using mass spectrometry, N‐terminal microsequencing, and Western‐immunoblotting to identify the yolk proteins (Yp), we show that multiple forms of vitellogenin mRNAs (vtgAa, vtgAb, and vtgC) are expressed in the liver, but only a single major class of the Yps derived from vtgAa predominates in the oocytes. Some Yps derived from vtgAb and vtgC appear also to be incorporated in the oocytes and eggs, but only at background levels. During oocyte hydration the vtgAa‐derived lipovitellin heavy chain (LvH‐Aa) and its cleavage variants are completely degraded leaving only a processed lipovitellin light chain (LvL‐Aa) fragment as the major yolk protein for embryonic development. The maturational cleavage site of the LvL‐Aa is identified as two amino acids downstream from the conserved Tyr1168 of VtgAa in Atlantic halibut. In addition, although a β′‐component (∼18 kDa) is present in the oocytes, it is not fully degraded during the hydration process. Mol. Reprod. Dev. 75: 1011–1020, 2007. © 2007 Wiley‐Liss, Inc.
Effect of temporary nuclear arrest by Phosphodiesterase 3‐Inhibitor on morphological and functional aspects of in vitro matured mouse oocytes
Authors: Vanhoutte Leen , Nogueira Daniela , Gerris Jan , Dhont Marc , De Sutter Petra
Published: December 2007

The present study aimed to analyze detailed morphological and functional characteristics of mouse in vitro matured oocytes after a pre‐maturation culture (PMC) by temporary nuclear arrest with the specific phosphodiesterase 3‐inhibitor (PDE3‐I) Cilostamide. In a first experiment the lowest effective dose of Cilostamide was determined. Cumulus–oocyte complexes (COCs), isolated from small antral follicles, were exposed to different concentrations of Cilostamide (ranging from 0 (control) to10 µM) for 24 hr. Afterwards, oocytes were removed from PDE3‐I‐containing medium and underwent in vitro maturation (IVM) for 16–18 hr. A concentration of 1 µM Cilostamide was the lowest effective dose for maximum level of inhibition and reversibility of meiosis inhibition. This concentration was used in further experiments to evaluate oocyte quality following IVM in relation to different parameters: kinetics of meiotic progression, metaphase II (MII) spindle morphology, aneuploidy rate, fertilization, and embryonic developmental rates. The results were compared to nonarrested (in vitro control) and in vivo matured oocytes (in vivo control). Following withdrawal of the inhibitor, the progression of meiosis was more synchronous and accelerated in arrested when compared to nonarrested oocytes. A PMC resulted in a significant increase in the number of oocytes constituting a MII spindle of normal morphology. None of the oocytes exposed to PDE3‐I showed numerical chromosome alterations. In addition, fertilization and embryonic developmental rates were higher in the PMC group compared to in vitro controls, but lower than in vivo controls. These results provide evidence that induced nuclear arrest by PDE3‐I is a safe and reliable method to improve oocyte quality after IVM. Mol. Reprod. Dev. 75: 1021–1030, 2007. © 2007 Wiley‐Liss, Inc.
Necessary and sufficient local convergence condition of one class of iterative aggregation–disaggregation methods
Authors: Pultarová Ivana
Published: December 2007

This paper concludes one part of the local convergence analysis of a certain class of iterative aggregation–disaggregation methods for computing a stationary probability distribution vector of an irreducible stochastic matrix B. We show that the local convergence of the algorithm is determined only by the sparsity pattern of the matrix and by the choice of the aggregation groups. We introduce the asymptotic convergence rates of the normalized components of approximations corresponding to particular aggregation groups and we also specify an upper bound on the rates. Copyright © 2008 John Wiley & Sons, Ltd.
Health outcomes associated with potentially inappropriate medication use in older adults
Authors: Fick Donna M. , Mion Lorraine C. , Beers Mark H. , L. Waller Jennifer
Published: December 2007

The purpose of this study was to examine the prevalence of potentially inappropriate medication use (PIMs) among community‐dwelling older adults and the association between PIMs and health care outcomes. Participants were 17,971 individuals age 65 years and older. PIM use was defined by the Beers criteria. Drug‐related problems (DRPs) were defined using ICD‐9 codes. Forty percent of the 17,971 individuals filled at least 1 PIM prescription, and 13% filled 2 or more PIM prescriptions. Overall DRP prevalence among those with at least 1 PIM prescription was 14.3% compared to 4.7% in the non‐PIM group (p < .001). In conclusion, preventing PIM use may be important for decreasing medication‐related problems, which are increasingly being recognized as requiring an integrated interdisciplinary approach. © 2007 Wiley Periodicals, Inc. Res Nurs Health 31:42–51, 2008
Examining pain‐related distress in relation to pain intensity and psychological distress
Authors: Wells Nancy , Ridner Sheila H.
Published: December 2007

Despite frequent use of the term symptom distress in the pain literature, symptom distress is often confused with symptom intensity and psychological distress, contributing to inadequate assessment of symptoms and less than ideal symptom management. In this article we address these issues and propose a hybrid model, combining Price's interaction of pain sensation, pain unpleasantness, and secondary pain affect model with an information processing model. Recommendations on methods and techniques to reduce this confusion would assist healthcare professionals and researchers to better distinguish among these terms as they manage patient symptoms and design symptom management studies. Thus, the purpose of this article is to examine the terms symptom distress, symptom intensity, and psychological distress using pain as the example symptom. © 2007 Wiley Periodicals, Inc. Res Nurs Health 31:52–62, 2008
The incorporation of rigid diol monomers into poly(butylene terephthalate) via solid‐state copolymerization and melt copolymerization
Authors: Jansen M. A. G. , Wu L. H. , Goossens J. G. P. , Wit G. de , Bailly C. , Koning C. E. , Portale G.
Published: December 2007

Incorporation of 2,2‐bis[4‐(2‐hydroxyethoxy)phenyl]propane (Dianol 220®) into poly(butylene terephthalate) (PBT) via solid‐state copolymerization (SSP) showed that Dianol, besides being the reactant, also acts as a swelling agent for rigid amorphous PBT chain segments. Being swollen, these amorphous chain segments become sufficiently mobile to contribute to the SSP process. The thermal behavior of the resulting copolyesters is comparable with melt copolymerized copolymers, although having a different chemical microstructure. The main reason is a full miscibility in the melt of unmodified PBT chain segments and modified chain segments, which eliminates the advantages of a blocky microstructure for the SSP copolyesters. However, incorporation of 2,2′‐biphenyldimethanol (BDM) into PBT resulted in a higher crystallization temperature compared with PBT–Dianol copolymers of equal composition. Preordering of polymer chains in the melt by incorporating rigid, phase separating BDM‐moieties, preferably via SSP to obtain a non‐random distribution, may be the origin of the enhanced crystallization temperature. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 1203–1217, 2008
ABCD 4‐miktoarm star quarterpolymers using click [3 + 2] reaction strategy
Authors: Altintas Ozcan , Hizal Gurkan , Tunca Umit
Published: December 2007

Two samples of ABCD 4‐miktoarm star quarterpolymer with A = polystyrene (PS), B = poly(ε‐caprolactone) (PCL), C = poly(methyl methacrylate) (PMMA) or poly(tert‐butyl acrylate) (PtBA), and D = poly(ethylene glycol) (PEG) were prepared using click reaction strategy (Cu(I)‐catalyzed Huisgen [3 + 2] reaction). Thus, first, predefined block copolymers of different polymerization routes, PS‐b‐PCL with azide and PMMA‐b‐PEG and PtBA‐b‐PEG copolymers with alkyne functionality, were synthesized and then these blocks were combined together in the presence of Cu(I)/N,N,N′,N″,N″‐pentamethyldiethylenetriamine as a catalyst in DMF at room temperature to give the target 4‐miktoarm star quarterpolymers. The obtained miktoarm star quarter polymers were characterized by GPC, NMR, and DSC measurements. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 1218–1228, 2008
New poly(ether‐ester) thermosets obtained by cationic curing of DGEBA and 7,7‐dimethyl‐6,8‐dioxaspiro[3.5] nonane‐5,9‐dione with several Lewis acids as initiators
Authors: González Lidia , Ramis Xavier , Salla Josep Maria , Mantecón Ana , Serra Angels
Published: December 2007

Scandium, ytterbium, and lanthanum triflates and boron trifluoride monoethylamine were used as cationic initiators to cure a mixture 2:1 (mol/mol) of diglycidylether of bisphenol A (DGEBA) and 7,7‐dimethyl‐6,8‐dioxaspiro[3.5]nonane‐5,9‐dione (MCB). The evolution of the epoxy and lactone during curing and the linear ester groups in the final materials were evaluated by Fourier Transform Infrared in the attenuated‐total‐reflection mode. The kinetic parameters of the curing process were calculated from DSC analysis applying isoconversional procedures. The shrinkage on curing and the thermal degradability of the materials on varying the initiator used were evaluated. The expandable character of MCB was confirmed. The materials obtained were more degradable than conventional epoxy resins due to the tertiary ester groups incorporated in the network by copolymerization. © 2008 Wiley Periodicals, Inc J Polym Sci Part A: Polym Chem 46: 1229–1239, 2008
Preparation of single‐walled carbon nanotubes‐induced poly(p‐oxybenzoyl) crystals
Authors: Kobashi Kazufumi , Lomeda Jay , Chen Zheyi , Azad Samina , Hwang Wen‐Fang , Tour James M.
Published: December 2007

Crystallization of oligomers was applied for the preparation of single‐walled carbon nanotubes (SWNTs)/poly(p‐oxybenzoyl) (POB) crystals using SWNTs as a nucleating agent. Polymerization conditions were investigated to induce the crystallization of POB oligomers through SWNTs. SWNTs/POB plate‐like or lozenge‐shaped crystals were successfully prepared by direct polymerization of p‐hydroxybenzoic acid (HBA) in a mixed solvent of DMF/Py with TsCl in the presence of functionalized SWNTs. The size of the plate‐like crystals were ∼200 nm to 3 μm. The crystals consisted of some layers, ∼3 nm thick plates. Model reactions showed that esterification reactions proceed between functionalized SWNTs and HBA monomers in the polymerization system. The obtained crystals exhibited unique morphology and high crystallinity, producing a novel SWNT/POB hybrid. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 1265–1277, 2008
Random and AB diblock copolymers of tricyclodecanemethanol urethane methacrylate with styrene: Synthesis and morphology characterization
Authors: Deepak V. D. , Asha S. K.
Published: December 2007

A monomer design having a bulky terminal tricyclodecane (TCD) unit linked via hydrogen bondable urethane to an ethyleneoxy methacrylate unit, and capable of generating three‐dimensional honeycomb patterns upon solvent casting has been investigated. Random copolymers as well as a diblock copolymer Poly(Sty42‐b‐TCD18) of this monomer with styrene were prepared by free‐radical polymerization route and atom transfer radical polymerization (ATRP) route. Morphology characterization was carried out using scanning electron microscopy (SEM) and transmission electron microscopy (TEM) analysis. Particle size was measured by dynamic light scattering measurements (DLS). Irrespective of the wide differences in molecular weight and polydispersity index values, the random copolymers having TCD content >30 mol % were found to form microporous films upon solvent casting from a THF/water 9:1 solvent combination. The amount of TCD in the copolymer was found to have an influence on the pore size formed. The diblock copolymer formed microspheres ∼200 nm in diameter. The thermal properties of all the polymers were studied using differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA), and the copolymers were found to have good thermal stability. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 1278–1288, 2008
Photoinitiated dispersion polymerization of methyl methacrylate: A quick approach to prepare polymer microspheres with narrow size distribution
Authors: Chen Jia , Zeng Zhaohua , Yang Jianwen , Chen Yonglie
Published: December 2007

Photoinitiated dispersion polymerization of methyl methacrylate was carried out in a mixture of ethanol and water as dispersion medium in the presence of poly(N‐vinylpyrrolidone) (PVP) as the steric stabilizer and Darocur 1173 as photoinitiator. 93.7% of conversion was achieved within 30 min of UV irradiation at room temperature, and microspheres with 0.94 μm number–average diameter and 1.04 polydispersity index (PDI) were obtained. X‐ray photoelectron spectroscope (XPS) analysis revealed that only parts of surface of the microspheres were covered by PVP. The particle size decreased from 2.34 to 0.98 μm as the concentration of PVP stabilizer increased from 2 to 15%. Extra stabilizer (higher than 15%) has no effect on the particle size and distribution. Increasing medium polarity or decreasing monomer and photoinitiator concentration resulted in a decrease in the particle size. Solvency of reaction medium toward stabilizer, which affects the adsorption of stabilizer on the particle surface, was shown to be crucial for controlling particle size and uniformity because of the high reaction rate in photoinitiated dispersion polymerization. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 1329–1338, 2008
Highly absorbing superabsorbent polymer
Authors: Mudiyanselage Thilini K. , Neckers Douglas C.
Published: December 2007

Acrylic acid (AA)–acrylamide (AM) based superabsorbent polymers (SAP) were synthesized by inverse suspension polymerization using potassium‐persulfate as the initiator, N,N′‐methylene bisacrylamide (BIS) as a crosslinker, sorbitan monostearate (Span 60) as the dispersant, cyclohexane as the solvent, and bis(methacryloylamino)‐azobenzene as the hydrophobic surface crosslinker. The influence of the polymerization parameters on the properties of the SAPs, water absorption (Q), morphology of the SAPs, swelling kinetics, salt resistance, and the reversibility of water absorption were investigated. The prepared SAPs have excellent water absorption, rapid water uptake, and good resistance to NaCl solutions. Furthermore, they show better reversible water uptake than the previously reported SAPs. The average water absorbency is 2800 g/g and 181 g/g of liquid absorbance in 0.025M NaCl solution. The initial water uptake rate is 1357 g/g/min and the reversibility of water absorption is 200 g/g in the repeated fourth cycle. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 1357–1364, 2008
Dispersion polymerization of MMA in supercritical CO2 stabilized by random copolymers of 1H,1H–perfluorooctyl methacrylate and 2‐(dimethylaminoethyl methacrylate)
Authors: Hwang Ha Soo , Yuvaraj Haldorai , Kim Won Soo , Lee Won‐Ki , Gal Yeong‐Soon , Lim Kwon Taek
Published: December 2007

A series of random copolymers, composed of 1H,1H‐perfluorooctyl methacrylate (FOMA) and 2‐dimethylaminoethyl methacrylate (DMAEMA) were prepared as stabilizers for the dispersion polymerization of methyl methacrylate in supercritical CO2 (scCO2). Free‐flowing, spherical poly(methyl methacrylate) (PMMA) particles were produced in high yield by the effective stabilization of poly(FOMA‐co‐DMAEMA) containing 34–67 w/w % (15–41 m/m %) FOMA structural units. Less stabilized but micron‐sized discrete particles could be obtained even with 25 w/w % (10 m/m %) FOMA stabilizer. The result showed that the composition of copolymeric stabilizers had a dramatic effect on the size and morphology of PMMA. The particle size was controllable with the surfactant concentration. The effect of the monomer concentration and the initial pressure on the polymerization was also investigated. The dry polymer powder obtained from dispersion polymerization could be redispersed to form stable aqueous latexes in an acidic buffered solution (pH = 2.1) by an electrostatic stabilization mechanism due to the ionization of DMAEMA units in the stabilizer. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 1365–1375, 2008
Atom transfer radical polymerization of methyl methacrylate catalyzed by ion exchange resin immobilized Co(II) hybrid catalyst
Authors: Huang Zhong Xi , Zhang Yong Ming , Li Hong , Luan Ying Hao , Liu Yan Gang
Published: December 2007

Ion exchange resin immobilized Co(II) catalyst with a small amount of soluble CuCl2/Me6TREN catalyst was successfully applied to atom transfer radical polymerization (ATRP) of methyl methacrylate (MMA) in DMF. Using this catalyst, a high conversion of MMA (>90%) was achieved. And poly(methyl methacrylate) (PMMA) with predicted molecular weight and narrow molecular weight distribution (Mw/Mn = 1.09–1.42) was obtained. The immobilized catalyst can be easily separated from the polymerization system by simple centrifugation after polymerization, resulting in the concentration of transition metal residues in polymer product was as low as 10 ppm. Both main catalytic activity and good controllability over the polymerization were retained by the recycled catalyst without any regeneration process. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 1416–1426, 2008
Novel silver/polyurethane nanocomposite by in situ reduction: Effects of the silver nanoparticles on phase and viscoelastic behavior
Authors: Cocca M. , D'Orazio L.
Published: December 2007

A novel silver/poly(carbonate urethane) nanocomposite was prepared through in situ reduction of a silver salt (AgNO3) added to a solution consisting of a commercial poly(carbonate urethane) dissolved in N,N‐dimethylformamide (DMF). In this system, the presence of the poly(carbonate urethane) was proved to protect the silver nanoparticles, whose formation was confirmed by means of UV–vis spectroscopy, from aggregation phenomena. The silver morphology developed in the solid state after DMF casting was imaged by FESEM. Homogeneous dispersion of silver nanoprisms in the poly(carbonate urethane) matrix was clearly observed. The effects of dispersion of silver nanoparticles within the poly(carbonate urethane) matrix were investigated by means of ATR‐FTIR and multifrequency dynamic mechanical thermal analyses. The obtained results revealed that the presence of silver nanoparticles modifies both the phase and the viscoelastic behaviors of poly(carbonate urethane). As a matter of fact, the hydrogen bond formation in the hard and soft segments was found to be hindered and the molecular motions of the soft segments were restricted, because a comparatively higher activation energy was required for the related α‐relaxation process. © 2008 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 46: 344–350, 2008
Effect of CO2 exposure on free volumes in polystyrene studied by positron annihilation spectroscopy
Authors: Chen Hongmin , Cheng Mei‐Ling , Jean Y. C. , Lee L. James , Yang Jintao
Published: December 2007

Free‐volume properties, size and distribution, in amorphous polystyrene exposed to CO2 gases have been measured as a function of pressure to 800 psi (5.5 MPa), of time, and of temperature using positron annihilation lifetime spectroscopy. The free volume increases significantly and its distribution broadens as a function of pressure. The free volume relaxes as a function of time with a characteristic time of 15 h, and 5.7 h for 400, and 800 psi, respectively, after depressurizing under vacuum. A portion of free volume created by CO2 exposure remains permanently in the polymer after CO2 exposure. The glass transition temperature decreases significantly as a function of CO2 pressure from the free‐volume data and is compared with the differential scanning calorimeter results. The observed free‐volume variations as a function of pressure, time, and temperature are discussed in terms of hole expansion, creation, free‐volume relaxation, plasticization, and hole filling in amorphous polymers. © 2008 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 46: 388–405, 2008
Measurement Error Correction for Distributed Properties – Filter Cake Thickness Measurements
Authors: Koch Michael , Saleem Mahmood , Krammer Gernot
Published: December 2007

The measurement of a distributed property is frequently encountered in engineering applications. The impact of a possible measurement error on the measured distribution is described and two methods to account for such an error are detailed: A Fourier transform based deconvolution procedure and a moment based deconvolution approach via kernel estimators are presented. The deconvolution methods can be used in many particle characterization and process applications where particle features or properties are commonly presented in a distributed form. In the current instance, these methods are carefully explored by using artificially generated data and applied to experimental data obtained from filter cake thickness measurements.
From the Rainbow to the Structure of Atoms
Authors: Gouesbet Gérard
Published: December 2007

The optical rainbow is nowadays of much use, in the laboratory and in industry, in the field of optical characterization. However, the geometrical optics interpretation of the optical rainbow generates a caustic singularity which is a clue that something is wrong, and that a more fundamental theory (in practice, wave optics, or Maxwell's equations) is required to explain the optical rainbow and to accurately enough interpret experiments. There also exists a mechanical rainbow in classical mechanics, also leading to a singularity, implying that classical mechanics is wrong too. To smooth out this singularity, we have to turn to a wave mechanics. By lifting the Hamilton‐Jacobi formulation of classical mechanics to a wave mechanics and looking to a time evolution equation, we may reach Schrödinger's equation. We therefore establish a beautiful connection between the rainbow in the sky, and the structure of atoms, in the sky and on earth.
Static Charging Elimination on Solid Particulates: Application to Polymer Production
Authors: Taillet Joseph
Published: December 2007

The elimination of static charging of bulk polymers conveyed by pneumatic transport is performed by injecting nanometric charged ice aerosols in a hopper of the facility, which permits full separation of the waste from pellets, to obtain higher quality product.
A Survey of Complementary Methods for the Characterization of Dense Colloidal Silica
Authors: Tourbin Mallorie , Frances Christine
Published: December 2007

The aim of this study is to enhance existing knowledge of different techniques developed for the characterization of stability and particle sizing of nanoparticles in dense dispersions subjected to interparticulate and hydrodynamic forces. Silica suspension, commercially known as Klebosol® 30R50 and consisting of a particle size of 80 nm on average, was investigated in the study over a wide range of concentrations. The investigations were carried out using different optical and acoustic techniques such as laser diffraction, multiple light scattering, photon correlation spectroscopy and acoustic spectroscopy. The study details the capabilities and limitations of these modern techniques based on the different physical principles behind the characterization of the size distribution of particles in suspensions. The results are presented in terms of particle size ranges, solid concentration and technological aspects such as online and offline analysis. An important finding is that many of these modern techniques need to be improved for applications at higher concentrations since the standard models become practically invalid because of the complex interaction of acoustic and optical waves with particles in suspensions of silica.
Genetic polymorphisms in CYP17, CYP3A4, CYP19A1, SRD5A2, IGF‐1, and IGFBP‐3 and prostate cancer risk in African‐American men: The Flint Men's Health Study
Authors: Sarma Aruna V. , Dunn Rodney L. , Lange Leslie A. , Ray Anna , Wang Yunfei , Lange Ethan M. , Cooney Kathleen A.
Published: December 2007

BACKGROUND

Association studies have examined the significance of several candidate genes based on biological pathways relevant to prostate carcinogenesis, including both the androgen and insulin‐like growth factor pathways. Clinical and epidemiologic evidence suggest that androgens, specifically testosterone and dihydrotestosterone (DHT) are important not only in normal prostate growth but in the pathogenesis of prostate cancer. Similarly, the insulin‐like growth factor‐1 (IGF‐1) signaling pathway regulates both cellular proliferation and apoptosis. Therefore, genes involved in the biosynthesis, activation, metabolism and degradation of androgens and the stimulation of mitogenic and antiapoptotic activities of prostate epithelial cells represent important candidates for affecting the development and progression of prostate cancer.

METHODS

Using resources from the Flint Men's Health Study, a population‐based case control study of African‐American men aged 40–79, we evaluated the associations between selected single‐nucleotide polymorphisms (SNPs) in the CYP17, CYP3A4, CYP19A1, SDR5A2, IGF1, and IGFBP3 genes and prostate cancer diagnosis in 473 men (131 prostate cancer cases and 342 disease‐free controls).

RESULTS

We found a significant association between prostate cancer and selected CYP17 SNP genotypes, with the heterozygous genotype conferring decreased risk. Suggestive evidence for association between IGF1 SNPs and prostate cancer were also found. No significant associations were observed between SNPs in the other genes and prostate cancer.

CONCLUSIONS

These findings suggest that variation in or around CYP17 and/or IGF1 may be associated with prostate cancer development in the African‐American population. Additional studies are needed to determine whether these polymorphisms are indeed associated with prostate cancer risk in African Americans. Prostate 68: 296–305, 2008. © 2007 Wiley‐Liss, Inc.
Glyphosate‐resistant weeds of South American cropping systems: an overview
Authors: Vila‐Aiub Martin M , Vidal Ribas A , Balbi Maria C , Gundel Pedro E , Trucco Frederico , Ghersa Claudio M
Published: December 2007

Herbicide resistance is an evolutionary event resulting from intense herbicide selection over genetically diverse weed populations. In South America, orchard, cereal and legume cropping systems show a strong dependence on glyphosate to control weeds. The goal of this report is to review the current knowledge on cases of evolved glyphosate‐resistant weeds in South American agriculture. The first reports of glyphosate resistance include populations of highly diverse taxa (Lolium multiflorum Lam., Conyza bonariensis L., C. canadensis L.). In all instances, resistance evolution followed intense glyphosate use in fruit fields of Chile and Brazil. In fruit orchards from Colombia, Parthenium hysterophorus L. has shown the ability to withstand high glyphosate rates. The recent appearance of glyphosate‐resistant Sorghum halepense L. and Euphorbia heterophylla L. in glyphosate‐resistant soybean fields of Argentina and Brazil, respectively, is of major concern. The evolution of glyphosate resistance has clearly taken place in those agroecosystems where glyphosate exerts a strong and continuous selection pressure on weeds. The massive adoption of no‐till practices together with the utilization of glyphosate‐resistant soybean crops are factors encouraging increase in glyphosate use. This phenomenon has been more evident in Argentina and Brazil. The exclusive reliance on glyphosate as the main tool for weed management results in agroecosystems biologically more prone to glyphosate resistance evolution. Copyright © 2007 Society of Chemical Industry
Anticoagulation monitoring and the role of general practice
Authors: Matthey Francis
Published: December 2007

Primary care‐based anticoagulation monitoring services are part of the new GMS contract. The author discusses the associated safety requirements and the convenience of the latest near‐patient testing devices. Copyright © 2007 Wiley Interface Ltd
Stream temperature dynamics within a New Zealand glacierized river basin
Authors: Cadbury S. L. , Hannah D. M. , Milner A. M. , Pearson C. P. , Brown L. E.
Published: December 2007

Knowledge of river thermal dynamics for glacierized basins is limited, despite the high sensitivity of these systems to climatic change/variability. This study examined spatio‐temporal water column and streambed temperature dynamics within a New Zealand glacierized river basin over two melt seasons. Water column temperature was recorded at three sites along the mainstem channel and four hillslope/groundwater‐fed tributaries. Air temperature, precipitation and stream discharge were monitored to characterize hydroclimatological conditions. Streambed temperature was monitored at the upper and lower main river sites at 0.05, 0.2 and 0.4 m depth. Water column temperature rose on average 0.6°C km−1 along the glacier‐fed mainstem. Temperature was elevated during warmer periods but the downstream increase was reduced due to greater meltwater production (consequently a larger total stream flow volume for atmospheric heating) plus a proportional reduction in warmer groundwater contributions. Hillslope/groundwater‐fed tributaries yielded a range of temperature patterns, indicating variable sourcing (meltwater or rainfall) and residence times. In the upper basin, streambed temperature was warmer than the water column, suggesting groundwater upwelling; however, during high runoff events, water column and streambed temperature converged, indicating downwelling/heat advection by channel water. At the lower site, streambed temperature mirrored the water column, suggesting greater surface water/atmospheric influences. Key drivers of stream thermal regime were: (1) relative water source contributions, (2) prevailing hydroclimatological conditions, (3) distance from source, (4) total stream flow volume and (5) basin factors (specifically, valley/channel geomorphology and riparian forest). High magnitude precipitation events produced a contrasting stream thermal response to that reported elsewhere. In contrast to European alpine research, streams showed a reduced thermal range owing to the relatively mild, wet melt season climate. This New Zealand case study highlights the importance of understanding basin‐specific modification of energy and hydrological fluxes for accurate prediction of stream thermal dynamics/habitat and ecological response to climatic variability and change. Copyright © 2007 John Wiley & Sons, Ltd.
Evaluation of the importance of roe deer fawns in the spring–summer diet of red foxes in southeastern Norway
Authors: Panzacchi Manuela , Linnell John D. C. , Serrao Giulia , Eie Sveinung , Odden Morten , Odden John , Andersen Reidar
Published: December 2007

Red foxVulpes vulpespredation on roe deerCapreolus capreolusfawns has the potential to strongly affect prey population dynamics, but it is unclear whether this relationship is symmetrical or not. We analysed the spring–summer diet of adult foxes and of their cubs in a fragmented agricultural area of southeastern Norway, where a parallel study showed that the predator kills annually 25% of the radio‐monitored roe deer fawns. The overall diet was highly varied and was dominated by small mammals (33% volume), especiallyMicrotus agrestis, and medium‐large mammals (25%), largely represented by fawns. The frequency of occurrence (FO) of fawns in the diet of adult foxes was highest in early spring, thus, supporting previous studies showing that the predator started actively hunting for fawns from the very beginning of the birth season. During the summer, the FO of both fawns and small mammals markedly declined, while that of berries and invertebrates increased. As expected for central‐place foragers, cubs consumed a higher proportion of large prey items compared to adults. In particular, 25% of scats from cubs—versus 9% from adults—contained roe deer remains, suggesting a high profitability of fawns for vixens raising offspring. However, considering the wide food spectrum and the availability of several large prey items in our study area, it seems unlikely that the importance of fawns to the diet and population dynamics of red foxes could be as great as the impact of the predator on roe deer populations. This asymmetrical relationship implies that there are unlikely to be any stabilising feedback mechanisms in the predator–prey relationship.
Critical role for c‐FLIPL on Fas resistance in colon carcinoma cell line HT‐29
Authors: Zang Fenglin , Sun Baocun , Zhao Xiulan , Niu Ruifang , Zhang Shiwu , Yu Man , Wei Xiyin , Zhang Lin
Published: December 2007

The cellular Fas‐associated death domain‐like interleukin‐1β‐converting enzyme inhibitory protein‐long form (c‐FLIPL) is a key regulator of Fas signaling, although owing a dominant‐negative homologue of caspase‐8, the role of c‐FLIPL remains controversial. In the present study, two pairs of small interfering RNA (siRNA) directed against c‐FLIPL were used to assess the effect of c‐FLIPL on Fas‐mediated apoptosis of colon carcinoma in vitro. HT‐29 cell line was selected for overexpression of c‐FLIPL and Fas with RT—PCR and flow cytometry analyses. After electroporation, the mRNA level of c‐FLIPL was significantly decreased (control siRNA versus c‐FLIPL siRNA, 77.97 ± 5.61% versus 26.22 ± 3.79%) and the maximum interfering efficiency was around 66.49% using semi‐quantitative RT—PCR analysis. Knockdown of c‐FLIPL with the specific siRNA sensitized colon carcinoma cells to Fas‐mediated apoptosis (control siRNA versus c‐FLIPL siRNA, 5.68 ± 2.11% versus 29.50 ± 2.27%) using DNA content analysis and Annexin V—FITC analysis. In conclusion, our study indicated that c‐FLIPL might be a suppressor of Fas‐mediated apoptosis in Fas antigen expressing colon carcinoma and therefore a potential target for novel anticancer therapies.
Rifting and lower crustal reflectivity: A case study of the intracratonic Dniepr‐Donets rift zone, Ukraine
Authors: Lyngsie Stig B. , Thybo Hans , Lang Rasmus
Published: December 2007

Intracratonic rifting, caused by late Devonian extensional stresses in the East European Craton, created the largest rift zone in Europe, the Pripyat‐Dniepr‐Donets rift (southeast Ukraine). The rift basin is approximately 2000 km long, up to 170 km wide, and 22 km deep. Wide‐angle refraction and reflection seismic data from the Donbas Basin deep seismic Refraction and Reflection Experiments (DOBRE'99) project together with gravity and magnetic data are analyzed for the structure and evolution of the Donbas Fold Belt, which is the uplifted and deformed part of the Dniepr‐Donets Basin. The seismic data are used for identification of large‐scale crustal structures and modeling of the seismic velocities of the crust and uppermost mantle. A ray‐trace‐based velocity and density model is derived by joint inversion of gravity and traveltime data. The inversion result reveals a zone of high density and velocity beneath the basin at middle to lower crustal levels, slightly offset to the NE of the rift axis. Full waveform synthetic seismograms, matching the observed data, show high‐amplitude and low‐frequency arrivals from this high‐density body as well as from the Moho. We interpret the high‐amplitude, low‐frequency signals as reflections from layered magmatic rocks, which intruded into the ductile lower crust during the main rift phase and subsequently were sorted by fractional crystallization. The intrusive material thickened the lower crust by approximately 50%. This may explain the enigmatic flat Moho topography across the rift zone which has been significantly stretched (β = 1.3). The rifting initiated in the late Devonian (Frasnien) as a consequence of back‐arc extension in relation to subduction of the Paleo‐Tethys Ocean. The subducting oceanic slab may have enriched the mantle with volatiles and created convection, leading to strong partial melting, upwelling, and continued rifting in the Famennien. We interpret the asymmetrical rift geometry as a combination of pure and simple shear tectonic processes.
Asperity generating upper crustal sources revealed by b value and isostatic residual anomaly grids in the area of Antofagasta, Chile
Authors: Sobiesiak M. , Meyer U. , Schmidt S. , Götze H.‐J. , Krawczyk C. M.
Published: December 2007

In our study we show that the locations of largest coseismic slip (asperities) on the fault plane of the Mw = 8.0 1995 Antofagasta earthquake in Northern Chile can be mapped by the spatial distribution of the seismic b value obtained from the aftershock sequence of the megathrust earthquake. These areas of high seismic moment release and concurrent high‐b values are congruent with anomalies of the gravity isostatic residual (IR) field in the Antofagasta region. They are superimposed on the seismogenic part of the north Chilean subduction zone where the strongest coupling of the upper and lower plate is expected. The IR anomalies are interpreted to be caused by large Jurassic–Early Cretaceous batholiths which intruded into the upper crust. The observed positive correlations between high seismic b values, IR anomalies, and geologic structures enable us to propose a mechanical model for the generation of the asperities in the Antofagasta region. We suggest that the batholiths in conjunction with buoyant forces acting on the subducted slab of the Nazca plate are responsible for locking the interface where the asperities are located. This implies long‐term conditions for the existence of the asperity generating tectonic situation. Concequently, the asperities around Antofagasta could be stationary features, at least for several seismic cycles. Hence we propose that the IR anomalies along the north Chilean convergent margin can be used as an indicator for high moment release and slip in future large earthquakes.
A new model of volatile bubble growth in a magmatic system: Isobaric case
Authors: L'Heureux Ivan
Published: December 2007

The nucleation, growth, and, ultimately, coalescence of volatile bubbles in a silicate melt (magma chamber) play a crucial role in the processes leading to volcanic eruptions. A new diffusion‐limited nonlinear growth and nucleation model of volatile bubbles in such a system is proposed here. In contrast to previously existing models, the present one treats the competitive effects of the other randomly located bubbles on the growth dynamics in presence of a hydrodynamic coupling with the melt advection field through its viscous resistance. I consider here cases where the fluid pressure is kept constant. Numerical results pertaining to a basaltic and a rhyolitic melt suggest that for small volatile supersaturations and for small times, bubble growth occurs essentially as in the single‐bubble problem. However, for longer times, the influence of the other bubbles is important. I find that bubble growth rate decreases exponentially with time and propose an approximate expression for the decay rate. Finally, for larger volatile supersaturations, the bubble growth is subjected to transitions to and from an inflationary regime, whereby the bubble radius increases very rapidly during a small time interval.
Unresolved issues with the assessment of multidecadal global land surface temperature trends
Authors: Pielke Roger A. , Davey Christopher A. , Niyogi Dev , Fall Souleymane , Steinweg‐Woods Jesse , Hubbard Ken , Lin Xiaomao , Cai Ming , Lim Young‐Kwon , Li Hong , Nielsen‐Gammon John , Gallo Kevin , Hale Robert , Mahmood Rezaul , Foster Stuart , McNider Richard T. , Blanken Peter
Published: December 2007

This paper documents various unresolved issues in using surface temperature trends as a metric for assessing global and regional climate change. A series of examples ranging from errors caused by temperature measurements at a monitoring station to the undocumented biases in the regionally and globally averaged time series are provided. The issues are poorly understood or documented and relate to micrometeorological impacts due to warm bias in nighttime minimum temperatures, poor siting of the instrumentation, effect of winds as well as surface atmospheric water vapor content on temperature trends, the quantification of uncertainties in the homogenization of surface temperature data, and the influence of land use/land cover (LULC) change on surface temperature trends. Because of the issues presented in this paper related to the analysis of multidecadal surface temperature we recommend that greater, more complete documentation and quantification of these issues be required for all observation stations that are intended to be used in such assessments. This is necessary for confidence in the actual observations of surface temperature variability and long‐term trends.
Extratropical stratosphere‐troposphere mass exchange associated with isentropic mixing: A 1992–2005 climatology derived from advection‐diffusion calculations
Authors: Nakamura Noboru
Published: December 2007

Tropopause folding and subsequent mixing are the primary vehicles for the stratosphere‐troposphere mass exchange in the extratropics, but to isolate the irreversible transport associated with these processes is difficult. In this paper, a potential vorticity (PV)‐like passive tracer, constructed from advection‐diffusion calculations, is used to characterize the extratropical tropopause layer and the mass fluxes through it. The calculations are driven by the Met Office Stratospheric Analysis winds interpolated on 20 isentropic surfaces (285–380 K) for the period of 1992–2005. The mass fluxes associated with isentropic mixing are computed in the tracer coordinate, thus excluding the deformation of the tropopause itself from transport. The fluxes are partitioned into stratosphere‐to‐troposphere (STT) and troposphere‐to‐stratosphere (TTS) components using the formalism of Nakamura. The STT flux outweighs the TTS flux by approximately 2 to 1 in both hemispheres. These fluxes are several times greater than the well‐known net annual mean tropopause flux (∼1010 kg s−1), and they increase sharply downward, acting to detrain mass from the tropopause layer. However, the observed mass of the tropopause layer is nearly steady throughout the year, suggesting that isentropic mixing is offset by other nonadvective processes on a seasonal timescale. Both the annual mean values and the seasonal variations of the mass fluxes are markedly greater in the Northern Hemisphere than in the Southern Hemisphere. Consistent with the previous studies, the Northern Hemisphere fluxes below 340 K maximize in spring and minimize in fall, whereas an almost opposite seasonality is observed above 340 K.