bluuebunny/crossref_metadata_2025_split huggingface dataset:
Improving the resolution of neuropeptides in rat brain with on‐line HILIC‐RP compared to on‐line SCX‐RP
Authors: Mihailova Albena , Malerød Helle , Wilson Steven Ray , Karaszewski Bartosz , Hauser Roman , Lundanes Elsa , Greibrokk Tyge 
Published: February 2008

AbstractOur two already established on‐line 2‐D LC systems, a strong cation exchange‐RP chromatography (SCX‐RP) system and a hydrophilic interaction LC (HILIC)‐RP 2‐D LC system, were compared to explore which system is best suited for our further studies of differences in cerebral neuropeptide expression as a function of hypoxia‐caused stress. The same mass spectrometer and database search parameters were applied in both systems. In total, 19 first dimension fractions were collected with the novel on‐line HILIC‐RP system, including a Hypercarb SPE column that was applied to trap the compounds not retained on a Kromasil C18 enrichment column. In contrast, six fractions were collected in the SCX‐RP method, due to practical limitations of this traditional on‐line 2‐D LC system. With the on‐line HILIC‐RP system three times more peaks were detected. It was observed that most of the compounds eluted in the first two fractions in the SCX‐RP method, while in the 2‐D HILIC‐RP method there seemed to be no correlation between peaks detected and fraction number. Thus, from this systematic study it seems that on‐line HILIC‐RP chromatography is the method of choice for comparative “peptidomics” of cerebral neuropeptides in future studies.
Analysis of calcineurin activity by capillary electrophoresis with laser‐induced fluorescence detection using peptide substrate
Authors: Enayetul Babar Sheikh Md. , Song Eun Joo , Yoo Young Sook 
Published: February 2008

AbstractReversible protein phosphorylation and dephosphorylation are very important activities in understanding cellular signaling networks. In this paper we described a CE‐LIF‐based assay method of calcineurin (CN), a protein phosphatase important in cardiac hypertrophy, in which a fluorescence‐labeled 19‐amino acid phosphopeptide was used as a substrate. The substrate was converted to a dephosphorylated product by CN and both the substrate and product were detected by the LIF detector. This assay method was tested for various separation parameters as well as reaction parameters. It was found that 100 mM of a boric acid buffer with a pH of 9.00 produced optimum separation at 10 kV of applied voltage using a 47 cm capillary. After obtaining the suitable reaction conditions the method was used to detect and quantify the CN activity in HL‐1 cell extracts where the picogram level of CN activity was obtained per microgram total protein. It was also observed that immunosuppressive drugs like okadaic acid and cyclosporine A inhibit in vitro CN activity.
Mass spectrometry strategies applied to the characterization of proline‐rich peptides from secretory parotid granules of pig (Sus scrofa)
Authors: Fanali Chiara , Inzitari Rosanna , Cabras Tiziana , Fiorita Antonella , Scarano Emanuele , Patamia Maria , Petruzzelli Raffaele , Bennick Anders , Messana Irene , Castagnola Massimo 
Published: February 2008

AbstractBasic proline‐rich proteins (bPRPs) are a class of proteins widely present in saliva of humans and other mammals. They are synthesized as preproproteins and enzymatically cleaved into small peptides before secretion from the salivary glands. Recently, we characterized two proline‐rich peptides (SP‐A and SP‐B) in parotid secretory granules of pig (Sus Scrofa) that are derived from three isoforms of a PRP proprotein (Swiss‐Prot data bank: Q95JC9‐1, Q95JC9‐2 and Q95JC9‐3). Together the coding regions for SP‐A and SP‐B, which are repeated many times, account for 52–70% of the coding regions of the PRP proproteins. This study was undertaken to identify peptides encoded by unassigned regions of the PRP proproteins. RP‐HPLC‐ESI‐IT‐MS analysis of enriched granule preparations from pig parotid glands by two different analytical strategies identified ten new proline‐rich peptides derived from the three proproteins. Together with the coding regions for SP‐A and SP‐B already identified it was possible to assign 68–75% of the proproteins coding regions. The peptide sequences indicated a number of unusual proteolytic cleavage sites suggesting the presence of unknown proprotein convertases.
Peptidomics: The integrated approach of MS, hyphenated techniques and bioinformatics for neuropeptide analysis
Authors: Boonen Kurt , Landuyt Bart , Baggerman Geert , Husson Steven J. , Huybrechts Jurgen , Schoofs Liliane 
Published: February 2008

AbstractMS is currently one of the most important analytical techniques in biological and medical research. ESI and MALDI launched the field of MS into biology. The performance of mass spectrometers increased tremendously over the past decades. Other technological advances increased the analytical power of biological MS even more. First, the advent of the genome projects allowed an automated analysis of mass spectrometric data. Second, improved separation techniques, like nanoscale HPLC, are essential for MS analysis of biomolecules. The recent progress in bioinformatics is the third factor that accelerated the biochemical analysis of macromolecules. The first part of this review will introduce the basics of these techniques. The field that integrates all these techniques to identify endogenous peptides is called peptidomics and will be discussed in the last section. This integrated approach aims at identifying all the present peptides in a cell, organ or organism (the peptidome). Today, peptidomics is used by several fields of research. Special emphasis will be given to the identification of neuropeptides, a class of short proteins that fulfil several important intercellular signalling functions in every animal. MS imaging techniques and biomarker discovery will also be discussed briefly.
Microstructured Reactors for Polymer Synthesis: A Renaissance of Continuous Flow Processes for Tailor‐Made Macromolecules?
Authors: Wilms Daniel , Klos Johannes , Frey Holger 
Published: February 2008

AbstractOrganic synthesis in microfluidic devices has attracted increasing interest in recent years. However, little efforts had been undertaken to exploit this novel technology for polymer chemistry until several recent studies demonstrated the interesting potential of microreactors for the synthesis and modification of polymers. In fact, anionic polymerizations in continuous capillary flow‐tube systems were established already in 1962 in pioneering work by Szwarc. Subsequent work focused on detailed kinetic analyses in such reactors. The present article explores different current strategies developed by several research groups to realize bulk and solution polymerizations using continuous flow microreactors. Inherent benefits and limitations of these systems compared to traditional laboratory set‐ups are discussed. We present a variety of recent pioneering and advanced approaches to realize free radical, controlled radical, cationic and anionic polymerizations in microtechnological reaction devices. In some cases, surprisingly narrow molecular weight distributions have been obtained, demonstrating the promising potential of this approach for the tailoring of polymer structures.magnified image
Herz spaces and summability of Fourier transforms
Authors: Feichtinger Hans G. , Weisz Ferenc 
Published: February 2008

AbstractA general summability method is considered for functions from Herz spaces Kαp,r (ℝd ). The boundedness of the Hardy–Littlewood maximal operator on Herz spaces is proved in some critical cases. This implies that the maximal operator of the θ ‐means σθ T f is also bounded on the corresponding Herz spaces and σθ T f → f a.e. for all f ∈ K–d /p p,∞ (ℝd ). Moreover, σθ T f (x) converges to f (x) at each p ‐Lebesgue point of f ∈ K–d /p p,∞ (ℝd ) if and only if the Fourier transform of θ is in the Herz space Kd /p p ′,1 (ℝd ). Norm convergence of the θ ‐means is also investigated in Herz spaces. As special cases some results are obtained for weighted Lp spaces. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Solutions of Volterra integral equations with infinite delay
Authors: Franco Daniel , O'Regan Donal 
Published: February 2008

AbstractWe present several new existence results for a Volterra integral equation with infinite delay. We discuss periodic and bounded solutions. Sufficient conditions for the existence of positive periodic solutions are also provided. The techniques we employ have not been used for this equation before. Our results generalize and complement those in the literature and several examples are presented to show their applicability. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The alternative Daugavet property of C *‐algebras and JB *‐triples
Authors: Martín Miguel 
Published: February 2008

AbstractA Banach space X is said to have the alternative Daugavet property if for every (bounded and linear) rank‐one operator T: X → X there exists a modulus one scalar ω such that ∥Id+ωT ∥ = 1 + ∥T ∥. We give geometric characterizations of this property in the setting of C *‐algebras, JB *‐triples, and of their isometric preduals. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Small sets for Neumann boundary conditions
Authors: Voigt Jürgen 
Published: February 2008

AbstractFor an open set D ⊆ ℝn and a relatively closed subset E ⊆ D of Lebesgue measure zero, we investigate conditions for the property that Brownian motion with reflexion at the boundary on D and D \ E are the same. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A semi‐analytical approach for modelling heat transfer during salt‐cavern leaching process
Authors: Rouabhi A. , Tijani M. , Stab O. , Charnavel Y. , You T. 
Published: February 2008

AbstractThe use of gas‐storage caverns in salt formations is a growing industry that continues to gain momentum because it allows gas to be injected and withdrawn at high rates compared with other underground gas‐storage systems such as porous rock systems.In order to predict cavern production performances, cavern thermodynamics behaviour must be studied by higher accuracy approaches. This behaviour is extremely related to the temperature distribution in the surrounding formations. During the leaching process, the thermal equilibrium of the rock salt surrounding the cavern is extensively disrupted. The purpose of this paper is to study the heat transfer problem during the leaching process and to develop a thermal model that can be easily used in field applications. The results of this work will be the input data for the prediction of the gas temperature and pressure during cavern gas‐storage operation phase. Moreover, the developed model can find its use in the design of salt caverns since it can be coupled with geometrical modelling of salt dissolution codes. Copyright © 2008 John Wiley & Sons, Ltd.
A semi‐algebraic approach that enables the design of inter‐grid operators to optimize multigrid convergence
Authors: Navarrete Michelini Pablo , Coyle Edward J. 
Published: February 2008

AbstractWe study the effect of inter‐grid operators—the interpolation and restriction operators—on the convergence of two‐grid algorithms for linear models. We show how a modal analysis of linear systems, along with some assumptions on the normal modes of the system, allows us to understand the role of inter‐grid operators in the speed and accuracy of a full‐multigrid step.We state an assumption that generalizes local Fourier analysis (LFA) by means of a precise description of aliasing effects on the system. This assumption condenses, in a single algebraic property called the harmonic aliasing property, all the information needed from the geometry of the discretization and the structure of the system's eigenvectors. We first state a harmonic aliasing property based on the standard coarsening strategies of 1D problems. Then, we extend this property to a more aggressive coarsening typically used in 2D problems with the help of additional assumptions on the structure of the system matrix.Under our general assumptions, we determine the exact rates at which groups of modal components of the error evolve and interact. With this knowledge, we are then able to design inter‐grid operators that optimize the two‐grid algorithm convergence. By different choices of operators, we verify the classic heuristics based on Fourier harmonic analysis, show a trade‐off between the rate of convergence and the number of computations required per iteration, and show how our analysis differs from LFA. Copyright © 2008 John Wiley & Sons, Ltd.
Multigrid Methods
Authors: Falgout Robert D. 
Published: February 2008

AbstractThis special issue contains papers from the Thirteenth Copper Mountain Conference on Multigrid Methods, held in the Colorado Rocky Mountains on March 19–23, 2007, co‐chaired by Van Henson and Joel Dendy. The papers address a variety of applications and cover a breadth of topics, ranging from theory to high‐performance computing. Copyright © 2008 John Wiley & Sons, Ltd.
New analysis of the optimization of electromagnetic shielding properties using conducting polymers and a multi‐objective approach
Authors: Schütze Oliver , Jourdan Laetitia , Legrand Thomas , Talbi El‐Ghazali , Wojkiewicz Jean‐Luc 
Published: February 2008

AbstractRecently, an approach was proposed to optimize multi‐layer shields of polyaniline–polyurethane (PAni/PU) conducting composites in the microwave band. Though by this method shields for different applications can be obtained which are light‐weight and offer a low percolation threshold, the full potential of the design process could not be tapped since the underlying optimization problem includes only one objective. In this work we go one step beyond and re‐formulate the design problem as a multi‐objective optimization problem (MOP). To be more precise, we involve simultaneously the shielding efficiency as well as the weight and the cost of the material—i.e. all the requirements for modern shielding materials—within the optimization process. After having stated the model we present two possible ways to approximate the solution set—the so‐called Pareto set—and address the related and important decision‐making problem. All steps are demonstrated on a particular three‐layered composite in order to show the applicability of the novel approach. Copyright © 2008 John Wiley & Sons, Ltd.
Café‐au‐lait macules and pediatric malignancy caused by biallelic mutations in the DNA mismatch repair (MMR) gene PMS2
Authors: Jackson Carl‐Christian , Holter Spring , Pollett Aaron , Clendenning Mark , Chou Shirley , Senter Leigha , Ramphal Raveena , Gallinger Steven , Boycott Kym 
Published: February 2008

AbstractA 14‐year‐old male presented with a T4 sigmoid adenocarcinoma, <10 colonic adenomas and multiple café‐au‐lait macules. Family history was not suggestive of a dominant hereditary form of colorectal cancer. Evaluation of the tumor revealed abnormal immunohistochemical staining of the PMS2 protein and high frequency microsatellite instability. Germline analysis identified biallelic PMS2 missense mutations. A new cancer syndrome caused by biallelic mutations in the mismatch repair genes, including PMS2, is now emerging and is characterized by café‐au‐lait macules, colonic polyps and a distinctive tumor spectrum. Pediatr Blood Cancer 2008;50:1268–1270. © 2008 Wiley‐Liss, Inc.
Synthesis, light emission, and photovoltaic properties of perylene‐containing polyacetylenes
Authors: Hua Jianli , Lam Jacky Wing Yip , Yu Xiaoming , Wu Lijun , Kwok Hoi Sing , Wong Kam Sing , Tang Ben Zhong 
Published: February 2008

AbstractPerylene (Py)‐containing polyacetylenes with different skeleton structures [HCC(C6H4)CO2Py]n (P1), [HCC(CH2)8CO2Py]n (P2), and {[(C6H5) CC(CH2)9NH2]co[(C6H5)CC(CH2)9Py]}n (P3) are synthesized in satisfactory yields by Rh‐catalyzed polymerization (for P1 and P2) and polymer reaction (for P3). All the polymers are soluble and possess high molecular weights (Mw up to 2.8 × 105). Their structures and properties are characterized and evaluated by IR, NMR, UV, TGA, PL, and photovoltaic (PV) analyses. The polymers are thermally stable, losing little of their weights when heated to 330 °C. When their solutions are irradiated, their perylene pendants emit intense red fluorescence at 610 nm. PV cells with a configuration of ITO/PEDOT:PSS/polymer/LiF/Al are fabricated, which show maximum current density of 10.3 μA/cm2. The external quantum efficiency is sensitive to the polymer structure, with P3 exhibiting the highest value of 0.23%. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 2025–2037, 2008
Metal nanocomposite films prepared in situ from PVA and silver nitrate. Study of the nanostructuration process and morphology as a function of the in situ routes
Authors: Clémenson S. , Léonard D. , Sage D. , David L. , Espuche E. 
Published: February 2008

AbstractCast‐hybrid films composed of polyvinyl alcohol (PVA) and silver nitrate were treated according to three different ways, thermal annealing, UV‐irradiation, and chemical reduction by a borohydride solution, to obtain PVA/silver nanocomposite films. The nanostructuration process was studied as a function of the treatment conditions, and discussed as a function of the mobility state of the polymer chains in the nanocomposite matrix during treatment. A homogeneous dispersion of crystalline silver nanoparticles was obtained by thermal annealing above Tg and below Tm and UV‐lamp irradiation below Tg. For these two treatments, the major processing parameters were the annealing temperature and time and the UV‐exposure time, respectively. For low‐conversion rate in Ag(0), the films evolved upon ageing at room temperature. Totally different morphology and Ag(0) conversion were achieved by chemical reduction in a borohydride solution. All the silver ions were reduced into Ag(0), and crystalline silver nanoparticles layers parallel to the film surface were observed after the treatment. This morphology was related to the high‐swollen state of the polymer matrix during treatment. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 2062–2071, 2008
Preparation and property of two soluble oxadiazole‐containing functional polyacetylenes
Authors: Wang Xin , Wu Jincui , Xu Hongyao , Wang Pei , Tang Ben Zhong 
Published: February 2008

AbstractTwo novel high‐molecular weight functional polyacetylenes (PA) bearing oxadiazole group as a pendant, poly(2‐(4‐octoxyphenyl)‐5‐(4‐ethynylphenyl)‐1,3,4‐oxadiazole) (P1) and poly(2‐(4′‐octoxyphenyl)‐5‐(4′‐propynyloxyphenyl)‐1,3,4‐oxadiazole) (P2) were synthesized by [Rh(nbd)Cl]2‐Et3N catalysts. Both polymers were soluble in common organic solvents such as CHCl3 and tetrahydrofuran. Their structures and properties were characterized and evaluated with FTIR, NMR, UV, thermogravimetric analysis, GPC, optical‐limiting and nonlinear optical analyses, respectively. The results show that linkage of oxadiazole chromophore to PA main chain has improved the nonlinear optical (NLO) property of PA, and endowed PA with novel optical limiting properties and enhanced thermal stability. Simultaneously, the optical‐limiting and NLO properties of the polymers were sensitive to their molecular structures. P1 with oxadiazole directly incorporated into PA main chain as a pendant showed better performances and larger third‐order nonlinear optical susceptibility than P2 with oxadiazole incorporated into PA main chain via a spacer. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 2072–2083, 2008
Poly(1,4‐cyclohexylenedimethylene 1,4‐cyclohexanedicarboxylate): Influence of stereochemistry of 1,4‐cyclohexylene units on the thermal properties
Authors: Berti Corrado , Binassi Enrico , Celli Annamaria , Colonna Martino , Fiorini Maurizio , Marchese Paola , Marianucci Elisabetta , Gazzano Massimo , Di Credico Francesco , Brunelle Daniel J. 
Published: February 2008

AbstractA series of poly(1,4‐cyclohexylenedimethylene 1,4‐cyclohexanedicarboxylate) (PCCD) samples, characterized by different cis/trans ratio of the 1,4‐cyclohexanedicarbonyl unit, have been synthesized and analyzed by thermogravimetry (TGA), calorimetry (DSC), and X‐ray diffraction (WAXD). The thermal stability results are good and are not affected by the stereochemistry of the 1,4‐cyclohexylene units. On the other hand, the thermal transitions are notably influenced by the cis/trans content. With the increment of the trans content the polymer changes from completely amorphous to semicrystalline material. Tg, Tm, and crystallinity increase. These results suggest that the trans configuration induces a better chain packing and higher symmetry, improving the crystallizability of the samples. The effect of the molecular structure on the thermal properties is analyzed by using a statistical approach. From the effective correlations found between stereochemistry of the C6 rings and transition temperatures it is possible to extrapolate that the configuration of 1,4‐cyclohexylene ring deriving from 1,4‐cyclohexanedicarboxylic acid or dimethyl 1,4‐cyclohexanedicarboxylate results to be the main element responsible for the thermal properties. This is due to the high rigidity of the 1,4‐cyclohexanedicarbonyl unit with respect to 1,4‐cyclohexanedimethyleneoxy unit, deriving from the diol. © 2008 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 46: 619–630, 2008
Energetic Materials: Crystallization, Characterization and Insensitive Plastic Bonded Explosives
Authors: van der Heijden Antoine E. D. M. , Creyghton Yves L. M. , Marino Emanuela , Bouma Richard H. B. , Scholtes Gert J. H. G. , Duvalois Willem , Roelands Marc C. P. M. 
Published: February 2008

AbstractThe product quality of energetic materials is predominantly determined by the crystallization process applied to produce these materials. It has been demonstrated in the past that the higher the product quality of the solid energetic ingredients, the less sensitive a plastic bonded explosive containing these energetic materials becomes. The application of submicron or nanometric energetic materials is generally considered to further decrease the sensitiveness of explosives. In order to assess the product quality of energetic materials, a range of analytical techniques is available. Recent attempts within the Reduced‐sensitivity RDX Round Robin (R4) have provided the EM community a better insight into these analytical techniques and in some cases a correlation between product quality and shock initiation of plastic bonded explosives containing (RS‐)RDX was identified, which would provide a possibility to discriminate between conventional and reduced sensitivity grades.
Characterization of Polymer‐Coated RDX and HMX Particles
Authors: da Costa Mattos Elizabeth , Moreira Enézio D. , Diniz Milton F. , Dutra Rita C. L. , da Silva Gilson , Iha Koshun , Teipel Ulrich 
Published: February 2008

AbstractFourier transform‐infrared spectroscopy (FT‐IR) in transmission and photoacoustic detection (PAS) techniques have been used for the characterization of polymeric coating of cyclotrimethylenetrinitramine (RDX) using a fluoroelastomer (Viton®). Although the bands of the polymer were indicated by two different techniques, the transmission (casting film) showed better evidence of absorption of fluoroelastomer for the polymer coating of the energetic material. Also attenuated total reflectance (ATR), another FT‐IR technique, has been used to analyze a cyclotetramethylenetetramine (HMX)/Viton system for the characterization of Viton bands and it showed excellent results without sample preparation.