bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ischemia‐induced ribosomal protein S3 expressional changes and the neuroprotective effect against experimental cerebral ischemic damage
Authors: Hwang In Koo , Yoo Ki‐Yeon , Kim Dae Won , Kim So Young , Park Jun Hong , Ryoo Zae Young , Kim Joon , Choi Soo Young , Won Moo‐Ho 
Published: January 2008

AbstractSome ribosomal proteins are important regulators of development and DNA repair. However, few studies have been conducted on ribosomal protein S3 (rpS3) in the ischemic hippocampus. In the present study, we investigated ischemia‐induced changes in rpS3 immunoreactivity, rpS3 mRNA, and protein levels in the hippocampal CA1 region of Mongolian gerbil after 5 min of transient forebrain ischemia. RpS3 immunoreactivity and its protein level were found to be significantly elevated at 6 hr after ischemia/reperfusion and then continuously decreased with time. RT‐PCR analysis also showed that rpS3 mRNA levels were significantly elevated in CA1 at 6 hr after transient ischemia. In addition, during the course of this study, we developed a delivery vector (Pep‐1) and its rpS3 fusion protein (Pep‐1–rpS3) to elucidate the role of rpS3 in ischemia‐induced damage. Pep‐1–rpS3 administration to ischemic animals significantly and dose dependently increased neuronal survival in the stratum pyramidale of CA1. Moreover, Pep‐1–rpS3 treatment reduced terminal deoxynucleotidyl dUTP nick‐end labeling‐positive CA1 pyramidal cell numbers in the stratum pyramidale. To elucidate how Pep‐1–rpS3 ameliorates ischemic damage, changes in 4‐hydroxy‐2‐nonnenal (HNE; an indicator of lipid peroxidation) immunoreactivity and protein levels were investigated. HNE levels and immunoreactivities in Pep‐1–rpS3‐treated ischemic animals were lower than in corresponding Pep‐1‐treated ischemic animals. These results indicate that rpS3 has a neuroprotective effect in the brain exposed to ischemia. © 2008 Wiley‐Liss, Inc.
Miniaturized two‐dimensional capillary electrophoresis on a microchip for analysis of the tryptic digest of proteins
Authors: Cong Yongzheng , Zhang Lihua , Tao Dingyin , Liang Yu , Zhang Weibing , Zhang Yukui 
Published: January 2008

AbstractA two‐dimensional capillary electrophoresis platform, combining isoelectric focusing (IEF) and capillary zone electrophoresis (CZE), was established on a microchip with the channel width and depth as 100 μm and 40 μm, respectively. With polyacrylamide as permanent coating, EOF in the microchannel, which could impair the separation, was decreased to 3.4×10–9m2·V–1·s–1, about 1/10 of that obtained in the uncoated set‐up. During the separation, peptides were first focused by IEF in the first dimensional channel, and then directly driven into the perpendicular channel by controlling the applied voltages, and separated by CZE. Effects of various experimental parameters, including the electric field strength, channel length, and injection frequency from the first to the second dimensional separation channel, were studied. Under optimized condition, the digests of BSA and proteins extracted fromE. coliwere separated, and a peak capacity of 540 was obtained, which was far greater than that obtained by each single dimensional separation. All these results showed the promise of multidimensional separation on a microchip for the high‐throughput and high‐resolution analysis of complex samples.
Separation and determination of enkephalin‐related peptides by capillary electrophoresis with amperometric detection
Authors: Wang Wei , Yao Sheyue , Qiu Bin , Chen Guonan 
Published: January 2008

AbstractA simple, reliable, and reproducible method for separation and determination of five enkephalin‐related peptides based on CE with amperometric detection (AD) is described in this paper. A potential of 1.0 V was applied to the carbon disk electrode, which was used as a working electrode in this system. At 15 kV of applied voltage, the five compounds were separated within 18 min in a 20 mmol/L phosphate buffer solution (PBS, pH 7.6) including 2.5% methanol v/v. LOD for five enkephalins were ranged from 6.31 to 54.3 nmol/L. The method was applied successfully to determine the five compounds added in the human cerebrospinal fluid (CSF) and the recoveries were in the range of 95.8–98.2%.
Melt Spinning of Poly(3‐hydroxybutyrate) for Tissue Engineering Using Electron‐Beam‐Irradiated Poly(3‐hydroxybutyrate) as Nucleation Agent
Authors: Vogel Roland , Voigt Dieter , Tändler Bernhard , Gohs Uwe , Häussler Liane , Brünig Harald 
Published: January 2008

AbstractElectron‐beam‐irradiated poly(3‐hydroxybutyrate) was used as a nucleating agent for poly(3‐hydroxybutyrate) in a melt‐spinning process. Molecular data and thermal properties of the irradiated samples were determined. The thermal properties of the nucleated melts were determined to assess the influence of the nucleation agents, and then spinning tests were carried out. Thermal and textile properties of the spun fibers were also determined. Estimations of the improvement of the crystallization in the spinline and of the inhibition of secondary crystallization in the fibers from the use of the described blood‐compatible nucleation agents are given.magnified image
Synthesis and Biological Evaluation of Disulfide‐Linked HPMA Copolymer‐Mesochlorin e6 Conjugates
Authors: Cuchelkar Vaikunth , Kopečková Pavla , Kopeček Jindřich 
Published: January 2008

AbstractNovel polymeric delivery systems for the photosensitizer mesochlorin e6 (Mce6) were synthesized to overcome problems of systemic toxicity. A disulfide bond was included to allow for quick release of Mce6 from the N‐(2‐hydroxypropyl)methacrylamide (HPMA) copolymer backbone once internalized in tumor tissue. The synthesized conjugates demonstrated a time‐dependent reductive cleavage with an accompanying increase in the quantum yield of singlet oxygen generation on exposure to DTT. Quicker release kinetics and a higher cytotoxicity in SKOV‐3 human ovarian carcinoma cells were obtained as compared to polymer conjugate with a proteolytically cleavable GFLG spacer. These novel conjugates hold promise as clinically relevant drug delivery systems for photodynamic therapy of cancer.magnified image
Corrosion control of phenylthiourea polymers on aluminium in alkaline medium
Authors: Vasanthi B. J. , Ravikumar L. , Selvaraj A. 
Published: January 2008

AbstractSimple phenylthiourea compounds are known for their high solubility in alkaline medium and for good corrosion control. The monomer N‐(4‐hydroxy‐3‐methoxybenzal)‐N′‐(4′‐hydroxyphenyl) thiourea was condensed with pimeloylchloride and azeloylchloride through inter‐facial polycondensation method to synthesize the polymers. The polymers were dissolved in 2 N sodium hydroxide and their corrosion controlling efficiency on aluminium was studied through AC impedance and potentiodynamic polarization methods.
Local electrochemical properties of laser beam‐welded high‐strength Al–Zn–Mg–Cu alloys
Authors: Wloka J. , Hack T. , Virtanen S. 
Published: January 2008

AbstractButt welds of two high‐strength Al–Zn–Mg–Cu alloys with different zinc contents were welded by a laser beam welding technique. Due to the high energy density of the laser beam, the microstructural changes are confined to very thin regions. Electrochemical properties of the weld heat‐affected zones are investigated by local electrochemical measurement techniques and correlated with microhardness measurements, macroscopic corrosion behaviour and metallographic sections. It turned out that microelectrochemical techniques, especially the EC‐pen is a versatile and easy to handle tool for the resolution of changes in the electrochemical properties across a weld bead. It unveils modifications, which cannot be resolved by hardness measurements. By microcell measurements, local corrosion kinetics can be estimated.
Novel Hyperbranched Poly(aryl ether urethane)s Using AB2‐Type Blocked Isocyanate Monomers and Copolymerization with AB‐Type Monomers
Authors: Shanmugam Thiyagarajan , Nasar A. Sultan 
Published: January 2008

AbstractA novel AB2‐type blocked isocyanate monomer was synthesized which was de‐blocked to provide a hyperbranched poly(aryl ether urethane). Copolymerization of this monomer with a functionally similar AB monomer yielded polymers with molecular weights in the range 8.0–310 kDa with a DB of 41–59% that underwent two‐stage decomposition above 200 °C. The inherent viscosities of the polymers in DMF ranged from 0.09 to 1.10 dL · g−1. End‐group modification of hyperbranched poly(aryl ether urethane)s was carried out with PEG monomethyl ether and 1‐decanol and affected the thermal properties and solubilities of the polymers. Tg of the polymers was reduced significantly from 201 to 71 °C upon incorporation of AB monomer in the copolymerization.magnified image
Functional Mesoporous Polymers From Phenolic Building Oligomers
Authors: Yang Zhenglong , Wang Junwei , Huang Kun , Ma Jin , Yang Zhenzhong , Lu Yunfeng 
Published: January 2008

AbstractNovel mesoporous polymers functionalized with carboxylic, sulfonic, and amino groups were synthesized by self‐organization of surfactant and functionalized phenolic building oligomers followed by surfactant removal. These materials have relatively large surface area, with a large number of functional groups on the pore walls, which may provide this new class of materials with enhanced adsorption capability and selectivity.magnified image
Prozessüberwachung beim thermischen Spritzen durch die Analyse akustischer Emissionen verifiziert durch die Methoden der CFD zur Berechnung der Schallemission beim HVOF‐Verfahren
Authors: Wielage B. , Rupprecht C. , Paczkowski G. 
Published: January 2008

AbstractDie zunehmende Automatisierung in der Thermischen Spritztechnik erfordert zuverlässige Prozessdiagnostikverfahren zur Sicherung der Beschichtungsqualität. Bisher kommen in der Industrie hauptsächlich optische Messverfahren zur Analyse der Spritzstrahlgeometrie und ‐partikelparameter zum Einsatz. Diese Verfahren sind im Gegensatz zur Akustikanalyse kostenintensiv und für schwach lichtemittierende Systeme wie HVOF‐ oder Kaltgasspritzen meist ungeeignet [1]. Da die starken akustischen Emissionen beim Thermischen Spritzen durch strömungsdynamische Effekte hervorgerufen werden, enthalten sie Informationen, die zur Bewertung der Funktionsfähigkeit und zur Weiterentwicklung von Spritzsystemen herangezogen werden können. Die vorliegende Arbeit zeigt Möglichkeiten, die akustischen Signale beim Lichtbogenspritzen und den Verbrennungslärm im HVOF‐Prozess messtechnisch zu erfassen. Dabei gewonnene Ergebnisse werden durch gekoppelte Methoden der Computed Fluid Dynamics (CFD) und Computed Akustik (CA) numerisch verifiziert. Da das Verständnis von akustischen Phänomenen auf der Physik der Schallausbreitung (Fluidschallakustik) basiert, erfolgt auszugsweise eine Darstellung der theoretischen Grundlagen.
Beurteilung von Loten und Lötverbindungen unter dem Einfluss steigender Kupfergehalte in verunreinigten bleifreien Lotbädern
Authors: Wielage B. , Weber D. , Lampke Th. 
Published: January 2008

AbstractZuverlässigkeit und Degradationsverhalten bleifreier Lote sind aufgrund von Widersprüchlichkeiten und notwendiger Problemlösungen nach wie vor Aspekte weiterer Untersuchungen. Die vorliegende Arbeit zeigt anhand von Phasenselektion der intermetallischen Phasen Ag3Sn und Cu6Sn5sowie (Cu,Ni)6Sn5und (Ni,Cu)3Sn4morphologisch‐mikrostrukturelle Zusammenhänge in Verbindung mit mechanischen Eigenschaften auf. Dazu wurden insbesondere das metallografische Tiefätzen und die instrumentierte Eindringprüfung genutzt. Die Lotlegierungen SnAg3,8CuX und SnCuXNi0,07 und deren Lötverbindungen wurden durch verschiedene Methoden komplex evaluiert. Es konnte nachgewiesen werden, dass das Zulegieren von Nickel als degradationsvermindernde Maßnahme des Kupfer‐Leachings zur Versprödung der Legierung durch das Wachstum der Phase (Cu,Ni)6Sn5führen kann.
ZnNi – Beschichtung hochfester Bauteile aus Stahl
Authors: Paatsch W. , Landgrebe R. , Lohrengel M. M. 
Published: January 2008

AbstractDie galvanotechnische Beschichtung hochfester Bauteile aus Stahl erfordert in der ganzen Prozesskette der Vorbehandlung, Beschichtung und Nachbehandlung im allgemeinen besondere Maßnahmen, um die Möglichkeit eines wasserstoffinduzierten verzögerten Sprödbruches mit der erforderlichen Sicherheit auszuschalten. Entscheidend ist hierbei, dass der durch die Oberflächenbehandlung in den Werkstoff eingedrungene Wasserstoff in jedem Fall in einer bezüglich des Mechanismus der Wasserstoffversprödung unterkritischen Konzentration vorliegt. Im Allgemeinen wird dies dadurch erreicht, dass nach einer spezifischen Vorbehandlung und einer galvanotechnischen Beschichtung mit sehr hoher Stromausbeute der Metallabscheidung eine nachfolgende Temperaturbehandlung der beschichteten Bauteile durchgeführt wird. Letztere kann nach vorliegenden Praxisergebnissen offensichtlich unter speziellen Bedingungen bei der alkalischen ZnNi‐Beschichtung entfallen. Es wird hierzu erklärend auf elektrochemische Untersuchungen zur Keimbildung und zum Kristallwachstum, zur Ermittlung des Diffusionsverhaltens von Wasserstoff durch ZnNi‐Schichten, zu Messungen des lokalen Tiefenprofils von Wasserstoff an beschichteten Bauteilen sowie zum mechanischen Verhalten beschichteter Bauteile eingegangen.
B compensation in 3T cardiac imaging using short 2DRF pulses
Authors: Sung Kyunghyun , Nayak Krishna S. 
Published: January 2008

AbstractThe purpose of this study was to determine if tailored 2DRF pulses could be used to compensate for in‐plane variations of the transmitted RF field at 3T. Excitation pulse profiles were designed to approximate the reciprocal of the measured RF transmit variation where the variation over the left ventricle was approximated as unidirectional. A simple 2DRF pulse design utilizing three subpulses was used, such that profiles could be quickly and easily adapted to different regions of interest. Results are presented from phantom and in vivo cardiac imaging. Compared with conventional slice‐selective excitation, the average flip angle variation over the left ventricle (measured as the standard deviation divided by the mean flip angle) was reduced with P < 0.001 and the average reduction was 41% in cardiac studies at 3T. Magn Reson Med, 2008. © 2008 Wiley‐Liss, Inc.
A geometrically adjustable 16‐channel transmit/receive transmission line array for improved RF efficiency and parallel imaging performance at 7 Tesla
Authors: Adriany Gregor , Van de Moortele Pierre‐Francois , Ritter Johannes , Moeller Steen , Auerbach Edward J. , Akgün Can , Snyder Carl J. , Vaughan Thomas , Uğurbil Kâmil 
Published: January 2008

AbstractA novel geometrically adjustable transceiver array system is presented. A key feature of the geometrically adjustable array was the introduction of decoupling capacitors that allow for automatic change in capacitance dependent on neighboring resonant element distance. The 16‐element head array version of such an adjustable coil based on transmission line technology was compared to fixed geometry transmission line arrays (TLAs) of various sizes at 7T. The focus of this comparison was on parallel imaging performance, RF transmit efficiency, and signal‐to‐noise ratio (SNR). Significant gains in parallel imaging performance and SNR were observed for the new coil and attributed to its adjustability and to the design of the individual elements with a three‐sided ground plane. Magn Reson Med, 2008. © 2008 Wiley‐Liss, Inc.
High‐pass GRAPPA: An image support reduction technique for improved partially parallel imaging
Authors: Huang Feng , Li Yu , Vijayakumar Sathya , Hertel Sarah , Duensing George R. 
Published: January 2008

AbstractPartially parallel imaging (PPI) is a widely used technique in clinical applications. A limitation of this technique is the strong noise and artifact in the reconstructed images when high reduction factors are used. This work aims to increase the clinical applicability of PPI by improving its performance at high reduction factors. A new concept, image support reduction, is introduced. A systematic filter‐design approach for image support reduction is proposed. This approach shows more advantages when used with an important existing PPI technique, GRAPPA. An improved GRAPPA method, high‐pass GRAPPA (hp‐GRAPPA), was developed based on this approach. The new technique does not involve changing the original GRAPPA kernel and performs reconstruction in almost the same amount of time. Experimentally, it is demonstrated that the reconstructed images using hp‐GRAPPA have much lower noise/artifact level than those reconstructed using GRAPPA. Magn Reson Med, 2008. © 2008 Wiley‐Liss, Inc.
Smooth contact strategies with emphasis on the modeling of balloon angioplasty with stenting
Authors: Kiousis D. E. , Gasser T. C. , Holzapfel G. A. 
Published: January 2008

AbstractCritical to the simulation of balloon angioplasty is the modeling of the contact between the artery wall and the medical devices. In standard approaches, the 3D contact surfaces are described by means of C0‐continuous facet‐based techniques, which may lead to numerical problems. This work introduces a novel contact algorithm where the target surfaces are described by polynomial expressions with C2‐continuity. On the basis of uniform cubic B‐splines, two different parametrization techniques are presented and compared, while the related implementation of the algorithm into a finite element analysis program is described. Two numerical examples are selected to demonstrate the special merits of the proposed contact formulation. The first example is a benchmark contact problem selected to point out the special features of the proposed strategies. The second example is concerned with the simulation of balloon angioplasty and stenting, where the contact between the balloon, the stent and the artery wall is numerically modeled. A patient‐specific 3D model of a stenotic femoral artery serves as a basis. The study concludes by identifying the changes in the mechanical environment of the artery in terms of contact forces and strains by considering two different stent designs. Copyright © 2008 John Wiley & Sons, Ltd.
An artificial compressibility method for viscous incompressible and low Mach number flows
Authors: Rahman M. M. , Siikonen T. 
Published: January 2008

AbstractWithin the framework of the pressure‐based algorithm, an artificial compressibility method is developed on a non‐orthogonal grid for incompressible and low Mach number fluid flow problems, using cell‐centered finite‐volume approximation. Resorting to the traditional pseudo‐compressibility concept, the continuity constraint is perturbed by the time derivative of pressure, the physical relevance of which is to invoke matrix preconditionings. The approach provokes density perturbations, assisting the transformation between primitive and conservative variables. A dual‐dissipation scheme for the pressure–velocity coupling is contrived, which has the expediences of greater flexibility and increased accuracy in a way similar to the monotone upstream‐centered schemes for conservation laws approach. To account for the flow directionality in the upwinding, a rotational matrix is introduced to evaluate the convective flux. Numerical experiments in reference to a few well‐documented laminar flows demonstrate that the entire contrivance expedites enhanced robustness and improved overall damping properties of the factored pseudo‐time integration procedure. Copyright © 2008 John Wiley & Sons, Ltd.
Supplementary data collection with case‐cohort analysis to address potential confounding in a cohort study of thromboembolism in oral contraceptive initiators matched on claims‐based propensity scores
Authors: Eng P. Mona , Seeger John D. , Loughlin Jeanne , Clifford C. Robin , Mentor BA. Sherry , Walker Alexander M. 
Published: January 2008

AbstractPurposeResidual confounding is a potential limitation of pharmacoepidemiologic studies, and in particular, studies based on administrative claims data that do not capture lifestyle and clinical confounders. We describe an application of the case‐cohort design to assess residual confounding by thromboembolic risk factors (e.g., smoking and obesity) not captured in claims data in a claims‐based cohort study of thromboembolism among matched oral contraceptive (OC) initiators.MethodsThis study was conducted using the Ingenix Research Data Mart, a database containing medical claims for approximately 12 million members of a large health plan of the United States. We randomly sampled 701 OC initiators from cohorts of ethinyl estradiol/drospirenone (n = 22 429) and other OC initiators (n = 44 858) identified in the years 2001–2004 and matched by propensity score in a claims‐based cohort study. Supplementary data on risk factors not measured in the cohort study were collected from medical records for the sample. We estimated the risk ratio of thromboembolism adjusted for the supplementary variables using Cox regression modified for a case‐cohort design, and compared it to the rate ratio from the cohort study.ResultsThe risk ratio adjusted for the supplementary variables was 0.90 (95 per cent (%) confidence interval (CI): 0.49, 1.68) which was similar to the rate ratio (0.92; 95%CI: 0.50, 1.63), indicating negligible confounding by the supplementary variables in the cohort study.ConclusionsCase‐cohort methods were used to assess residual confounding in a claims‐based cohort study. This approach adds to a growing number of methods to evaluate residual confounding in cohort studies. Copyright © 2008 John Wiley & Sons, Ltd.
Magnetite‐coated polystyrene hybrid microspheres prepared by miniemulsion polymerization
Authors: Wen Hui‐Ying , Gao Ge , Han Zhao‐Rang , Liu Feng‐Qi 
Published: January 2008

AbstractHybrid microspheres with a polystyrene core coated with magnetite nanoparticles were prepared by miniemulsion polymerization. Acrylic acid was used as a comonomer to promote the anchoring of the magnetite nanoparticles onto the polymeric surface. The addition of a hydrophobic agent prevents effectively the monomer from diffusing into the aqueous phase. Magnetite was treated with a silane coupling agent in order to introduce some interactions with the polymers. The morphology and the structure of the hybrid microspheres were characterized using X‐ray diffraction, infrared spectroscopy, transmission electron microscopy and thermogravimetric analysis. The results show that the morphology of the hybrid microspheres was influenced by the concentrations of acrylic acid, hydrophobic agent and surfactant, and that the degree of coating can be tuned by changing these parameters. The miniemulsion polymerization technique is adaptable to the synthesis of magnetite‐coated polymer particles, and the synthesis can be scaled up. Copyright © 2008 Society of Chemical Industry