bluuebunny/crossref_metadata_2025_split huggingface dataset:
Integrin repertoire on myogenic cells changes during the course of primary myogenesis in the mouse
Authors: Cachaço Ana Sofia , Pereira Carlos Silva , Pardal Rita G. , Bajanca Fernanda , Thorsteinsdóttir Sólveig 
Published: February 2005

AbstractCells interact with the extracellular matrix through receptors, most commonly of the integrin family. We (Cachaço et al. [2003] Development 130:1659–1671) and others (Schwander et al. [2003] Dev. Cell 4:673–685) have demonstrated a role for β1 integrins in mouse primary myogenesis. However, it is unclear what α subunits pair with β1 during this process in vivo. Here, we determined α subunit expression patterns at embryonic day (E) 11.5–E14.5. Differentiated myotomal myocytes express all α subunits studied. As the muscle masses form both in trunk (E12.5) and limbs (E11.5–E12.5), laminin receptors α6β1 and α7β1 are undetectable, and an assembled laminin matrix is absent. Instead α1β1, α4β1, α5β1, and an αv‐containing integrin are expressed and unassembled laminin and fibronectin are abundant around myogenic cells. At E13.5–E14.5, α6β1 and α7β1 are expressed, and a laminin matrix forms around individual myotubes. Thus, myogenic cells change their integrin expression pattern during the course of primary myogenesis in the mouse, suggesting different roles for fibronectin‐ and laminin‐containing matrices in this process. Developmental Dynamics 232:1069–1078, 2005. © 2005 Wiley‐Liss, Inc.
Human alpha rhythms during visual delayed choice reaction time tasks: A magnetoencephalography study, Human Brain Mapping 2005;24(3):184–192
Authors: Babiloni Claudio , Babiloni Fabio , Carducci Filippo , Cincotti Febo , Del Percio Claudio , Della Penna Stefania , Franciotti Raffaella , Pignotti Sandro , Pizzella Vittorio , Rossini Paolo Maria , Sabatini Elisabetta , Torquati Kathya , Romani Gian Luca 
Published: February 2005

AbstractThe original article to which this Erratum refers was published in the March 2005 issue of Human Brain Mapping Human Brain Mapping (2005) 24(3) 184–192.
Accuracy and efficiency of atomic basis set methods versus plane wave calculations with ultrasoft pseudopotentials for DNA base molecules
Authors: Pulay Peter , Saebo Svein , Malagoli Massimo , Baker Jon 
Published: February 2005

AbstractRecent results from Preuss et al. (J Comput Chem 2004, 25, 112) on DNA base molecules, obtained by plane wave density functional calculations using ultrasoft pseudopotentials, are compared with calculations using Gaussian basis sets. Bond lengths and angles agree closely, but dihedral angles and vibrational frequencies show significant differences. The Gaussian basis calculations are at least an order of magnitude more efficient than the plane wave/ultrasoft pseudopotential calculations at a similar level of accuracy; the advantage is even larger if the Fourier Transform Coulomb method is used. To obtain definite benchmark values, the geometries of the four DNA bases were optimized at the MP2 level with large basis sets, up to cc‐pVQZ and aug‐cc‐pVTZ. © 2005 Wiley Periodicals, Inc. J Comput Chem 26: 599–605, 2005
Simultaneous determination of noradrenaline and dopamine in Portulaca oleracea L. by capillary zone electrophoresis
Authors: Yue Mei‐E , Jiang Ting‐Fu , Shi Yan‐Ping 
Published: February 2005

AbstractA simple and rapid capillary electrophoretic method was developed for the simultaneous determination of noradrenaline (NA) and dopamine (DA) in Portulaca oleracea L. The buffer solution used in this method was 40 mM tris (hydroxymethyl) aminomethane (Tris)‐H3PO4 at pH 2.00 containing 15% methanol. The effects of pH value, organic modifier, and applied voltage were investigated. The linear ranges of NA and DA were 0.5–100 μg/mL (r = 0.9952) and 6.25–200 μg/mL (r = 0.9992), respectively. The relative standard deviations of the corrected peak area were 6.73% and 4.26%, respectively. NA and DA in Portulaca oleracea L. were simultaneous determined successfully within 5.6 min. In this way, the contents of NA and DA in different parts (stem, leaves, and seeds) of P. oleracea L. and in different extracts of leaves with different solvents (distilled water, 50% methanol, and methanol) were studied.
Quantitative determination of antalarmin, a novel corticotropin‐releasing hormone receptor‐1 antagonist, in canine plasma by HPLC‐MS
Authors: Fox Stephen D. , Roman John M. , Cizza Giovanni , Veenstra Timothy D. , Issaq Haleem J. 
Published: February 2005

AbstractA simple and rapid method was developed for the quantitation of antalarmin from plasma using high performance liquid chromatography coupled with electrospray ionization mass spectrometry (ESI/MS). Separation of antalarmin from interfering compounds was achieved using reversed phase chromatography on a C‐8 micro‐column with an isocratic mobile phase comprised of 80% acetonitrile, 20% water, and 5 mM triethylamine. Detection by ESI/MS was accomplished in positive ion mode using single ion monitoring of the protonated molecular ions of antalarmin and its 13C2‐isotopimer. The area ratio of the integrated peaks of interest in the extracted ion chromatogram was used for quantitation. The lower limit of detection was 1 picogram (pg) and the quantitation showed a linear response up to 4 nanograms loaded on column. To achieve acceptable accuracy at or around the limit of quantitation of 20 pg, a 1/x weighting was applied to the calibration data. Accuracy and precision variation for intra and inter‐day validation were below the acceptable limit (15%) for pharmacokinetic studies.
The full evaporation technique: A promising alternative for residual solvents analysis in solid samples
Authors: Brault Audrey , Agasse Valérie , Cardinael Pascal , Combret Jean‐Claude 
Published: February 2005

AbstractThe static headspace technique is the most common approach to residual solvent analysis in pharmaceutical and environmental matrices. This paper presents an alternative tool where the volatile impurities are released from the matrix by working directly on a small amount of sample at a high equilibration temperature: the so‐called Full Evaporation Technique (FET). The capability of this method was evaluated on a mixture of nine solvents, which belong to Class 3 in the classification of the European Pharmacopoeia Agency for residual solvents, at various levels of concentration: ethanol, acetone, 2‐propanol, methyl acetate, 2‐butanone, ethyl acetate, tetrahydrofuran, 2‐methyl‐1‐propanol, 1‐butanol. Data on linearity, accuracy, precision and sensitivity are reported. Use of an internal standard proved to be necessary when using such a method. The method is then successfully applied to the analysis of solvent traces in permethylated β‐cyclodextrin.
Influence of the pore structure on the properties of silica based reversed phase packings for LC
Authors: Szabó Zoltan , Ohmacht Robert , Huck Christian W. , Stöggl Wolfgang M. , Bonn Günther K. 
Published: February 2005

AbstractThis paper describes the preparation and investigation of new, highly loaded, monomeric, silica based, reversed phase C18 and C30 packings. The influence of pore structure and endcapping on the properties of C18 and C30 packings is described. Using hydrothermal procedures, silicas with predictable pore size (9.3–25.5 nm) and surface area have been prepared. Silylation with long chain silanes substantially alters the pore structure of the silica: pore size and pore volume decrease. A new parameter, the volumetric surface coverage [mm3×m–2] has been introduced. This parameter – calculated from on‐column measured porosity data – indicates the pore volume portion occupied by the hydrocarbon chains. Endcapping does not significantly change the pore structure of the bonded phases. The reduced retentions (reduced with respect to unit area: [k/m2]) – a good measure for comparing the retention behaviour of packings with different surface areas – are similar for most of the phases, demonstrating good accessibility of the pores for the solutes. Slightly lower retentions were found on the endcapped than on the non‐endcapped phases for probes with dense π‐electron system (e. g. polyaromatic hydrocarbons) demonstrating the contribution of silanophilic interactions to the retention. The phases had been successfully used for various demanding separations, e. g. for the separation of flavonoids, carotenoids, resveratrol, and tocopherol isomers, fullerenes, and anions.
Nanoscale Blends between Immiscible Polymers via Simultaneous Non‐Interfering Polymerisation
Authors: Zinck Philippe , Brachais Claire‐Hélène , Finot Eric , Barbier‐Baudry Denise 
Published: February 2005

AbstractSummary: An important topic in polymer science seeks to improve the performances of polymer blends using nanoscale phase segregation. Here, blends between polystyrene and polycaprolactone are realised by a chemical route. The non‐interfering character of the radical polymerisation of styrene and the lanthanide halide initiated ring‐opening polymerisation of caprolactone is assessed. The molecular weights range from 2 000 to 3 500 for polycaprolactone and up to 140 000 for polystyrene, with reasonable polydispersity indexes. From calorimetry measurements, it is shown that polystyrene and low molecular weight polycaprolactone are immiscible. The morphology of the blends between the two immiscible polymers studied by atomic force microscopy is consistent with nanometer‐scale phase segregation.AFM surface image of a nanoscale blend.magnified imageAFM surface image of a nanoscale blend.
Synthesis and Optical Properties of a New Series of Side‐Chain Poly(amic acid)s With p‐π Conjugation
Authors: Li Najun , Lu Jianmei , Yao Shechun 
Published: February 2005

AbstractSummary: After the condensation polymerization of benzoguanamine (BGA) and pyromellitic dianhydride (PMDA) under microwave irradiation, the resulting p‐π conjugate poly(amic acid) was grafted via the azo coupling reaction. The obtained side‐chain polymers were further grafted with TDI‐aliphatic alcohol derivatives and TDI‐aniline derivatives. The third‐order NLO coefficient and response time of PAA and graft polymers were measured by degenerated four wave mixing (DFWM) technique and their fluorescent properties were also investigated. All of the graft polymers have larger NLO coefficients and film‐formability than PAA. Their fluorescent properties were also changed by the different electronic effect of the side‐chains. The influences of the introduction of side‐chains, the side‐chain length and the electronic effect of the substituting groups on the azobenzol side‐chain to both optical properties of the polymers by varying the conjugation degree were investigated.
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Cationic Copolymerization Behavior of Glycidyl Phenyl Ether with Seven‐Membered Cyclic Carbonate
Authors: Morikawa Hiroshi , Sudo Atsushi , Nishida Haruo , Endo Takeshi 
Published: February 2005

AbstractSummary: To clarify the cationic copolymerization behavior of epoxide and cyclic carbonate, the copolymerization behavior of glycidyl phenyl ether (GPE) with seven‐membered cyclic carbonate (7CC) was carried out using methyl trifluoromethanesulfonate (MeOTf) as a cationic initiator. The addition of 7CC accelerated the consumption rate of GPE, and the resulting copolymers were richer in 7CC‐derived unit compared to the feed ratio of 7CC. During the copolymerization, a large amount of five‐membered cyclic carbonate having a phenoxymethyl group (PM‐5CC) was produced as a by‐product, which suggests the corresponding spiroorthocarbonate was formed as an intermediate and that residual oxytetramethylene (OTM) unit was incorporated into the copolymer sequence. From 1H NMR analysis, it was found that the copolymers had a statistically random sequence consisting of GPE, 7CC, and OTM units.
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Atom Transfer Radical Polymerization of Solketal Acrylate Using Cyclohexanone as the Solvent
Authors: Zhen Yuee , Wan Shourong , Liu Yuanqin , Yan Husheng , Shi Rongfu , Wang Chunhong 
Published: February 2005

AbstractSummary: Solketal acrylate (SA) was homopolymerized by atom transfer radical polymerization (ATRP) using CuBr/N,N,N′,N″,N″‐pentamethyldiethylenetriamine as the catalyst and cyclohexanone as the solvent with controlled molecular weights and low polydispersities. The prepared bromine‐terminated homopolymers, PSA, were used as macroinitiators to initiate polymerization of tert‐butyl acrylate (tBA) under similar ATRP conditions to produce diblock copolymers, PSA‐b‐PtBA, with controlled molecular weights and low polydispersities. ATRP of SA using bromine‐terminated PtBA as the macroinitiator was also carried out and diblock copolymers, PtBA‐b‐PSA, were obtained. The PSA block was selectively hydrolyzed by stirring for 3 h in 6 N HCl/THF (1/9, v/v) at room temperature to form a poly(glycerol monoacrylate) block. Both blocks of PSA and PtBA were hydrolyzed by stirring in anhydrous trifluoroacetic acid (TFA)/dichloromethane for 4 h, then adding water to the system and stirring for another 3 h to form corresponding diblock copolymers of glycerol monoacrylate and acrylic acid.Kinetic plot for the atom transfer radical polymerization of solketal acrylate at 90 °C.magnified imageKinetic plot for the atom transfer radical polymerization of solketal acrylate at 90 °C.
Interpolymer Complexes between Hydroxypropylcellulose and Copolymers of Maleic Acid: A Comparative Study
Authors: Bumbu Gina‐Gabriela , Vasile Cornelia , Chitanu Gabrielle Charlotte , Staikos Georgios 
Published: February 2005

AbstractSummary: The formation of interpolymer complexes (IPCs) between hydroxypropylcellulose (HPC) and copolymers of maleic acid with vinyl acetate (MAc‐VA), acrylic acid (MAc‐AA) and styrene (MAc‐S) in aqueous solution has been investigated by turbidimetry, viscometry and fluorescence measurements. The viscosity data indicated a compact structure for the IPCs between HPC and maleic acid copolymers. Besides H‐bonding, strong hydrophobic forces materialize between HPC and MAc‐S, strengthening this IPC. The strength of the interpolymer interactions was estimated to increase in the order: HPC:MAc‐VA < HPC:MAc‐AA < HPC:MAc‐S. The IPCs of HPC with MAc‐VA or MAc‐AA were water‐soluble at pH values higher than 3, while the IPC between HPC and MAc‐S was water‐soluble at pH values above 4.5.Cloud point temperature of different interpolymer complexes as a function of copolymer concentration.magnified imageCloud point temperature of different interpolymer complexes as a function of copolymer concentration.
Cover Picture: Macromol. Chem. Phys. 5/2005
Authors: Bumbu Gina‐Gabriela , Vasile Cornelia , Chitanu Gabrielle Charlotte , Staikos Georgios 
Published: February 2005

Cover: The formation and stability of interpolymer complexes (IPCs) of hydoxypropylcellulose with different copolymers of maleic acid depend on the hydrophobic/hydrophilic balance of the copolymers. The solubility of the IPCs decreases by lowering the pH.Further details can be found in the Full Paper by G.‐G. Bumbu,* C. Vasile, G. C. Chitanu, and G. Staikos on page 540.
Enabling location‐based services in wireless LAN hotspots
Authors: Chen Yen‐Cheng , Chan Yao‐Jung , She Cheung‐Wo 
Published: February 2005

AbstractThe wide deployment of IEEE 802.11 Wireless LAN (WLAN) makes possible application services developed in WLAN hotspots. Owing to the small cell size in WLAN hotspots, it is practical to develop location‐based services with the awareness of the WLAN access points (APs) that mobile devices currently access. In this paper, we propose an effective location determination technique using the inherent SNMP support in WLAN APs. It is shown that the current location of a mobile device can be determined from the SNMP traps sent by APs. Since the SNMP‐based approach doesn't need any particular software or hardware in mobile devices, location‐based services can be widely deployed, especially in public WLAN hotspots. To further enable location‐based services through the WWW, this paper also considers the location determination of a mobile device from its IP address, retrieved in a WWW environment. In addition, we propose a web service framework for location‐based services in WLAN hotspots. Thus, location‐based services can be developed in a standard way. Copyright © 2005 John Wiley & Sons, Ltd.
Efficient authenticated key agreement protocols resistant to a denial‐of‐service attack
Authors: Tseng Yuh‐Min 
Published: February 2005

AbstractMalicious intruders may launch as many invalid requests as possible without establishing a server connection to bring server service to a standstill. This is called a denial‐of‐service (DoS) or distributed DoS (DDoS) attack. Until now, there has been no complete solution to resisting a DoS/DDoS attack. Therefore, it is an important network security issue to reduce the impact of a DoS/DDoS attack. A resource‐exhaustion attack on a server is one kind of denial‐of‐service attack. In this article we address the resource‐exhaustion problem in authentication and key agreement protocols. The resource‐exhaustion attack consists of both the CPU‐exhaustion attack and the storage‐exhaustion attack. In 2001, Hirose and Matsuura proposed an authenticated key agreement protocol (AKAP) that was the first protocol simultaneously resistant to both the CPU‐exhaustion attack and the storage‐exhaustion attack. However, their protocol is time‐consuming for legal users in order to withstand the DoS attack. Therefore, in this paper, we propose a slight modification to the Hirose–Matsuura protocol to reduce the computation cost. Both the Hirose–Matsuura and the modified protocols provide implicit key confirmation. Also, we propose another authenticated key agreement protocol with explicit key confirmation. The new protocol requires less computation cost. Because DoS/DDoS attacks come in a variety of forms, the proposed protocols cannot fully disallow a DoS/DDoS attack. However, they reduce the effect of such an attack and thus make it more difficult for the attack to succeed. Copyright © 2005 John Wiley & Sons, Ltd.
Preparation and characterization of novel conducting polyaniline–perlite composites
Authors: Arsalani Nasser , Hayatifar Mohammad 
Published: February 2005

AbstractThe development of composites displaying electrical conductivity has attracted significant research attention over the last decade due to the possibility of new applications. For the first time, we describe the preparation of composites in which perlite particles have been combined with the well‐known conducting polyaniline (PAni). Such composites have been prepared by the in situ deposition of a thin coating of chemically synthesized polyaniline onto perlite particles (diameter <250 µm). These composite materials have been characterized by FT‐IR spectroscopy, scanning electron microscopy, thermogravimetric analysis and four‐point probe conductivity measurements. In addition, the effects of reaction time, perlite particle size and type of protonic acid medium on the conductivities of the composites have been investigated. Their conductivities were also compared to those of mechanical blends of polyaniline and perlite. Copyright © 2005 Society of Chemical Industry
Comparative structural analysis of TonB‐dependent outer membrane transporters: Implications for the transport cycle
Authors: Chimento David P. , Kadner Robert J. , Wiener Michael C. 
Published: February 2005

AbstractTonB‐dependent outer membrane transporters (TBDTs) transport organometallic substrates across the outer membranes of Gram‐negative bacteria. Currently, structures of four different TBDTs have been determined by X‐ray crystallography. TBDT structures consist of a 22‐stranded β‐barrel enclosing a hatch domain. Structure‐based sequence alignment of these four TBDTs indicates the presence of highly conserved motifs in both the hatch and barrel domains. The conserved motifs of the two domains are always in close proximity to each other and interact. We analyzed the very large interfaces between the barrel and hatch domains of TBDTs and compared their properties to those of other protein–protein interfaces. These interfaces are extensively hydrated. Most of the interfacial waters form hydrogen bonds to either the barrel or the hatch domain, with the remainder functioning as bridging waters in the interface. The hatch/barrel interfacial properties most resemble those of obligate transient protein complexes, suggesting that the interface is conducive to conformational change and/or movement of the hatch within the barrel. These results indicate that TBDTs can readily accommodate substantial conformational change and movement of their hatch domains during the active transport cycle. Also, these structural changes may require only modest forces exerted by the energy‐coupling TonB protein upon the transporter. Proteins 2005. © 2005 Wiley‐Liss, Inc.
Optical and electrical properties of oriented thin films of oligomer containing betaine‐type moiety in side chain
Authors: Muzikante I. , Fonavs E. , Tokmakov A. , Cepite D. , Stiller B. , Brehmer L. , Neilands† O. 
Published: February 2005

AbstractNon‐linear optical and electrical properties of polymer films obtained by dipole orientation of active units are reported. Novel polar oligomer with N‐(indan‐1,3‐dion‐2‐yl)pyridinium betaine (IPB) as a side group is studied. Orientation of polar groups in oligomer thin films causes an increase of the photo‐induced change of surface potential on irradiation in the region of photo‐induced electron transfer (PIET) where the IPB group exhibits a reversible change of the value and sign of the dipole moment. At longer wavelengths, the value of the surface potential of the oligomer may be determined by transport of photo‐generated charge carriers. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Ethyl anion preferred conformation
Authors: Goodman Lionel , Sauers Ronald R. 
Published: February 2005

AbstractAb initio architecture and torsional barrier for ethyl anion, C2Hare analyzed using natural bond orbital methodology. The B3LYP/6‐311++G(3df,2p) 2‐kcal/mol torsional barrier between the preferred staggered and higher‐energy eclipsed conformer is calculated to be one‐third lower than for ethane. This decrease is largely attributed to reduced hyperconjugative stabilization of the equilibrium anion conformer compared to that for ethane. Proton removal is also predicted to cause opening of the ethane central CCH angle by 7°, attributed to decreased steric repulsion and to increased hyperconjugative stabilization accompanying angle widening in the ion. © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
Enzymatic and catalytic reduction of dinitrogen to ammonia: Density functional theory characterization of alternative molybdenum active sites
Authors: Cao Zexing , Zhou Zhaohui , Wan Huilin , Zhang Qianer 
Published: February 2005

AbstractWe used density functional calculations to model dinitrogen reduction by a FeMo cofactor containing a central nitrogen atom and by a Mo‐based catalyst. Plausible intermediates, reaction pathways, and relative energetics in the enzymatic and catalytic reduction of N2 to ammonia at a single Mo center are explored. Calculations indicate that the binding of N2 to the Mo atom and the subsequent multiple proton–electron transfer to dinitrogen and its protonated species involved in the conversion of N2 are feasible energetically. In the reduction of N2 the Mo atom experiences a cycled oxidation state from Mo(IV) to Mo(VI) by nitrogenase and from Mo(III) to Mo(VI) by the molybdenum catalyst, respectively, tuning the gradual reduction of N2. Such a wide range of oxidation states exhibited by the Mo center is crucial for the gradual reduction process via successive proton–electron transfer. Present results suggest that the Mo atom in the N‐centered FeMo cofactor is a likely alternative active site for dinitrogen binding and reduction under mild conditions once there is an empty site available at the Mo site. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2005