bluuebunny/crossref_metadata_2025_split huggingface dataset:
Enhancement of permeability in endothelial cells for the development of an antithrombogenic bioartificial hemofilter
Authors: Vu Duc M. , Yokoyama Tun A. , Sawada Kaichiro , Inagaki Miho , Kanai Genta , Lu Jianxin , Kakuta Takatoshi , Adler Stephen , Nangaku Masaomi , Saito Akira 
Published: April 2008

AbstractFor the development of an antithrombogenic bioartificial hemofilter, in which the inner surface of hollow fibers is lined by endothelial cells, it is essential to increase the permeability of the cells in order to achieve a sufficient ultrafiltrate. We tried to increase it by using an actin microfilament polymerization inhibitor, cytochalasin B (CyB). Fifty µg/mL CyB was added for 2 h to the culture medium of confluent rat glomerular endothelial cells (RGEC) and human umbilical vein endothelial cells (HUVEC). Under the 130 mmHg hydrostatic pressure, the CyB‐treated group produced significantly more ultrafiltration than the non‐treated control group and this increase was maintained for at least 7 days. Horseradish peroxidase (HRP) permeability acutely and reversibly increased in the CyB‐treated group compared with the non‐treated control group. Scanning electron microscopy revealed a larger average diameter and increased number of fenestrae on the CyB‐treated endothelial cells, compared with the non‐treated cells. This phenomenon also lasted for at least 7 days. The platelet adherence test showed that CyB did not deteriorate the antithrombogenic property of endothelial cells. These results indicate that CyB is potentially applicable for the enhancement of endothelial cell permeability in an antithrombogenic bioartificial hemofilter. Biotechnol. Bioeng. 2008;101: 634–641. © 2008 Wiley Periodicals, Inc.
Encapsulation of Ferrocene and Peripheral Electrostatic Attachment of Viologens to Dimeric Molecular Capsules Formed by an Octaacid, Deep‐Cavity Cavitand
Authors: Podkoscielny Dagmara , Philip Ivy , Gibb Corinne L. D. , Gibb Bruce C. , Kaifer Angel E. 
Published: March 2008

AbstractIn aqueous media the deep‐cavity cavitand octaacid 1 forms stable dimeric molecular capsules 12, which are stabilized by hydrophobic effects. In this work we investigate the binding interactions in aqueous solution between these capsules and the redox active guests, ferrocene (Fc) and three 4,4′‐bipyridinium (viologen) dications: methyl viologen (MV2+), ethyl viologen (EV2+), and butyl viologen (BV2+). Using NMR spectroscopic and electrochemical techniques we clearly show that the hydrophobic Fc guest is encapsulated inside 12. An interesting effect of this encapsulation is that the reversible voltammetric response of Fc is completely eliminated when it resides inside the 12 capsular assembly, a finding that is attributed to very slow electrochemical kinetics for the oxidation of Fc@12. Diffusion coefficient measurements (PGSE NMR spectroscopy) reveal that all three viologen guests are strongly bound to the dimeric capsules. However, the 1H NMR spectroscopic data are not consistent with encapsulation and the measured diffusion coefficients indicate that two viologen guests can strongly associate with a single dimeric capsule. Furthermore, the (V2+)2⋅ 12 complex is capable of encapsulating ferrocene, clearly suggesting that the viologen guests are bound externally, via coulombic interactions, to the anionic polar ends of the capsule. The electrochemical kinetic rate constants for the reduction of the viologen residue in the V2+⋅12 complexes were measured and found to be substantially lower than those for the free viologen guests.
The transient response study of CO, CO2, and O2 adsorption and CO oxidation over La0.4Sr0.6Co0.4Mn0.6O3
Authors: Li Rong , Yu Shui‐Xian , Wang Fu‐Shan , Sun Sheng‐Lian , Ma Jian‐Tai 
Published: March 2008

AbstractThe transient behaviour caused by the change of the component concentration for CO oxidation on the perovskite‐type catalyst La0.4Sr0.6Co0.4Mn0.6O3 was investigated. Results showed that CO was not adsorbed on the catalyst surface and CO oxidation was carried out between the surface oxygen species and gas phase CO. On the other hand, CO2 can be adsorbed on the catalyst surface but its adsorption site was different from the forming site.
Heat transfer to a moving packed bed of nickel pellets
Authors: Baird M. H. I. , Rama Rao N. V. , Tackie E. , Vahed A. 
Published: March 2008

AbstractHeat transfer between a bed of nickel pellets and a vertical section of electrically heated steel pipe has been measured, with the pellet bed inside the vertical pipe. Most of the data are for a 20.27 cm diameter pipe but some data were also obtained for a 10.23 cm diameter pipe. The effective thermal conductivity of the stationary pellet bed has been estimated approximately from the results of unsteady heating tests. Tests have been carried out with a downwardly moving bed, including the effect of air flowing upwards through the bed. Average values of the pellet‐side heat transfer coefficient are between 72 and 135 W/(m2°C) depending on the mass fluxes of air and pellets, and have been expressed as an empirical correlation.
Corrosion inhibition of carbon steel under two‐phase flow (water‐petroleum) simulated by turbulently agitated system
Authors: Slaiman Qasim J. M. , Hasan Basim O. , Mahmood Hussein A. 
Published: March 2008

AbstractThe corrosion of carbon steel in single‐phase (water with 0.1N NaCl) and two immiscible phases (kerosene‐water) using turbulently agitated system was investigated. The experiments were carried out for Reynolds number (Re) range of 38 000 to 95 000 using circular disc turbine agitator at 40°C. In two‐phase system, test runs were carried out in aqueous phase (water) concentrations of 1% vol, 5% vol, 8% vol, and 16.4% vol mixed with kerosene at various Re. The effect of Re, percent of dispersed phase, dispersed droplet diameter, and number of droplets per unit volume on the corrosion rate were investigated and discussed. Test runs were carried out using two types of inhibitors: sodium nitrite of concentrations 20, 40, and 60 ppm and sodium hexapolyphosphate of concentrations 485, 970, and 1940 ppm in a solution containing 8% vol aqueous phase (water) mixed with kerosene (continuous phase) at 40°C for the whole range of Re. It was found that increasing Re increased the corrosion rate and the presence of water enhanced the corrosion rate by increasing the solution electrical conductivity. For two‐phase solution containing 8% vol and 16% vol of water, the corrosion rate was higher than single phase (100% vol water). The main parameters that play the major role in determining the corrosion rate in two phases were concentration of oxygen, solution electrical conductivity, and the interfacial area between the two phases (dispersed and continuous). Sodium nitrite and sodium hexapolyphosphate were found to be efficient inhibitors in two‐phase solution for the investigated range of Re.
Liquid flow in impeller region of an unbaffled agitated vessel with an angularly oscillating impeller
Authors: Yoshida Masanori , Hiura Tomoko , Yamagiwa Kazuaki , Ohkawa Akira , Tezura Shuichi 
Published: March 2008

AbstractThe characteristics of a liquid flow were studied in the impeller region of an unbaffled agitated vessel with an angularly oscillating impeller whose unsteady rotation proceeds while periodically reversing its direction at a set angle. The measurement of the velocity of the liquid flow was performed by particle tracking velocimetry (PTV), abreast of that of the torque of the shaft to which the impeller was attached. When a disk turbine impeller with six flat blades was used with variations in operating conditions, such as the frequency and amplitude of impeller angular oscillation, a series of images obtained during one oscillation cycle were analyzed to characterize the internal and discharge streams inside and outside the impeller rotational region. Energy data were inferred on the basis of the circumferential and radial velocities of an internal flow. Results showed that although the total head provided to the liquid by the impeller blades is almost similar, independent of the amplitude of impeller angular oscillation, namely, the acceleration of its movement, the transformation of energy from the pressure head to the velocity head is more efficient at a larger amplitude. In addition, the discharge flow was characterized in terms of volumetric flow rates calculated from the radial and axial velocities. The operation at a smaller amplitude was shown to transform the flow more successfully from the radial direction to the upward and downward axial directions near the vessel wall.
A cadherin‐based code for the divisions of the mouse basal ganglia
Authors: Hertel Nicole , Krishna‐K  , Nuernberger Monique , Redies Christoph 
Published: March 2008

AbstractThe expression of 12 different classic cadherins and δ‐protocadherins was mapped in consecutive series of sections through the basal ganglia of the postnatal and adult mouse by in situ hybridization. A particular focus was the caudoputamen, which consists of patches (striosomes) and a surrounding matrix that is histologically uniform. The different areas within the caudoputamen are connected specifically to other parts of the basal ganglia and to other brain regions, for example, the substantia nigra. The molecules regulating the morphogenesis and functional connectivity of the basal ganglia are largely unknown. Previous studies suggested that cadherins, a large family of adhesion molecules, are involved in basal ganglia development. In the present work, we study the expression of 12 cadherins and show that the patch and matrix compartments of the caudoputamen express the cadherins differentially, although partial overlap is observed. Moreover, the cadherins are expressed in multiple and diverse gradients within the caudoputamen and other parts of the basal ganglia. The persistence of the expression patterns in the adult basal ganglia suggests the possibility that cadherins also play a role at adult stages. Our results suggest that cadherins provide a code of potentially adhesive cues that specify not only patch and matrix compartments but also multiple molecular gradients within the basal ganglia. This code may relate to patterns of connectivity. J. Comp. Neurol. 508:511–528, 2008. © 2008 Wiley‐Liss, Inc.
Exact integration of polynomial–exponential products with application to wave‐based numerical methods
Authors: Gabard G. 
Published: March 2008

AbstractWave‐based numerical methods often require to integrate products of polynomials and exponentials. With quadrature methods, this task can be particularly expensive at high frequencies as large numbers of integration points are required. This paper presents a set of closed‐form solutions for the integrals of polynomial–exponential products in two and three dimensions. These results apply to arbitrary polygons in two dimensions, and for arbitrary polygonal surfaces or polyhedral volumes in three dimensions. Quadrature methods are therefore not required for this class of integrals that can be evaluated quickly and exactly. Copyright © 2008 John Wiley & Sons, Ltd.
Theoretical Study on the Complexes of Benzene with Isoelectronic Nitrogen‐Containing Heterocycles
Authors: Wang Weizhou , Hobza Pavel 
Published: April 2008

AbstractThe π–π interactions between benzene and the aromatic nitrogen heterocycles pyridine, pyrimidine, 1,3,5‐triazine, 1,2,3‐triazine, 1,2,4,5‐tetrazine, and 1,2,3,4,5‐pentazine are systematically investigated. The T‐shaped structures of all complexes studied exhibit a contraction of the CH bond accompanied by a rather large blue shift (40–52 cm−1) of its stretching frequency, and they are almost isoenergetic with the corresponding displaced‐parallel structures at reliable levels of theory. With increasing number of nitrogen atoms in the heterocycle, the geometries, frequencies, energies, percentage of s character at C, and the electron density in the CH σ antibonding orbital of the complexes all increase or decrease systematically. Decomposition analysis of the total binding energy showed that for all the complexes, the dispersion energy is the dominant attractive contribution, and a rather large attraction originating from electrostatic contribution is compensated by its exchange counterpart.
Intrachain versus Interchain Electron Transport in Poly(fluorene‐alt‐benzothiadiazole): A Quantum‐Chemical Insight
Authors: Van Vooren Antoine , Kim Ji‐Seon , Cornil Jérôme 
Published: April 2008

AbstractPoly(9,9‐di‐n‐octylfluorene‐alt‐benzothiadiazole) [F8BT], displays very different charge‐transport properties for holes versus electrons when comparing annealed and pristine thin films and transport parallel (intrachain) and perpendicular (interchain) to the polymer axes. The present theoretical contribution focuses on the electron‐transport properties of F8BT chains and compares the efficiency of intrachain versus interchain transport in the hopping regime. The theoretical results rationalize significantly lowered electron mobility in annealed F8BT thin films and the smaller mobility anisotropy (μ∥/μ⊥) measured for electrons in aligned films (i.e. 5–7 compared to 10–15 for holes).
The influence of N2 flow rate and substrate temperature on Ti1‐xAlxN thin films
Authors: Irudayaraj A. Albert , Kalainathan S. 
Published: March 2008

AbstractTitanium aluminium nitride (Ti1‐xAlxN) films have been deposited on silicon (111) substrate at a N2 flow rate of 2 sccm and 20 sccm and at a substrate temperature of 773 K and at a N2 flow rate of 2 sccm and at a substrate temperature of 873 K by reactive DC magnetron sputtering technique. The effect of N2 flow rate and substrate temperature on the grain size and surface roughness of the deposited films have been investigated. The films have been analysed by X‐ray diffraction (XRD) and atomic force microscopy (AFM). The films were found to be nanocrystalline. While the grain size of the films decreases with increasing N2 flow rate and decreases with increasing substrate temperature, the surface roughness of the films decreases with increasing N2 flow rate and increases with increasing temperature. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
CD28 ligation in the absence of TCR promotes RelA/NF‐κB recruitment and trans‐activation of the HIV‐1 LTR
Authors: Annibaldi Alessandro , Sajeva Angela , Muscolini Michela , Ciccosanti Fabiola , Corazzari Marco , Piacentini Mauro , Tuosto Loretta 
Published: April 2008

AbstractCD28 is one of the most important co‐stimulatory receptors necessary for full T lymphocyte activation. CD28 can act as a TCR‐independent signalling unit by delivering specific signals which may induce HIV transcription and replication. However, the mechanisms by which CD28 regulates HIV expression remain largely unknown. Here we show that the TCR‐independent CD28 signals lead to the trans‐activation of HIV‐1 LTR in an NF‐κB‐dependent manner. In particular, we found that CD28 engagement by B7 induces the specific recruitment of RelA/NF‐κB subunit to the HIV‐1 LTR promoter both in vitro and in ex vivo infected cells. The results obtained by mutating specific tyrosine residues within the CD28 cytoplasmic tail as well as by using LY294002 inhibitory drug evidenced that the recruitment and activation of the phosphatidylinositol 3‐kinase/Akt signalling pathway is crucial in mediating CD28‐induced HIV transcription through RelA/NF‐κB.
Synthesis, Structures and Ion‐Association Properties of a Series of Schiff Base Oxidovanadium(V) Complexes with 4‐Substituted Long Alkoxy Chains
Authors: Abe Yuriko , Iyoda Ayako , Seto Kanako , Moriguchi Ayano , Tanase Tomoaki , Yokoyama Haruhiko 
Published: March 2008

AbstractSchiff base VO2V and VOV complexes with long 4‐substituted alkoxy chains have been synthesised from the corresponding VOIV complexes, [VO{(4‐CnH2n+1O)xsalen}] [x = 1, 2, n = 3–16 and salen = N,N′‐ethylenebis(salicylideneiminato)], in solutions in the absence or presence of HClO4 under aerobic conditions. The green single‐crystals of the VOIV complexes (x = 2, n = 3, 4, 6) coexisting with solutions without HClO4 turned slowly to the yellow single‐crystals of the species with n = 3 (1) and 4 (2), a process which took several months. An X‐ray crystallographic analysis revealed that the VOIV complexes are transformed into the dimeric VO2V complexes with the tridentate sal‐en (sal‐en = N‐salicylideneethylenediamine) ligand from the tetradentate salen moieties. However, the single crystals of the VOIV complexes with longer alkoxy chains of n ≥ 8 did not yield the corresponding yellow crystals of the VO2V complexes. This crystal‐to‐crystal transformation is discussed in relation to the crystal packing structures of the VOIV complexes. In contrast, addition of HClO4 solution to two series with one and two alkoxy chains in the 4‐positions immediately afforded the corresponding blue VOV perchlorate complexes, [VO{(4‐CnH2n+1O)xsalen}]ClO4 (x = 1, 2) without transformation of the salen moieties. The structure of 8·MeOH·0.5H2O determined from an X‐ray crystallographic analysis was a unique dimeric structure supported by electrostatic stacking and CH–π interactions in an octahedral environment. The DFT calculations were studied to obtain the stabilisation energy for the dimerisation. Furthermore, in methanol solution, the effects of the alkoxy chain lengths on the ion association were investigated by conductivity measurements. The ion‐association state in methanol solution is discussed with the solid‐state structure.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Synthesis and Structural Characterization of a Tetrameric Ammonium Chloride Cluster
Authors: Schulenberg Nikola , Hübner Olaf , Kaifer Elisabeth , Himmel Hans‐Jörg 
Published: March 2008

AbstractHerein we report the synthesis and structural characterization of a derivative of the molecular cluster [NH4Cl]4. The N and Cl atoms in this compound are located at alternating corners of a slightly distorted cube in the crystal phase and are bound together through N–H···Cl bridges. This structure is in good agreement with quantum chemical calculations carried out for the [NH4Cl]4 tetramer. ESI mass spectra recorded for the compound dissolved in different solvents indicate that the cluster is stable in relatively apolar solvents such as CH2Cl2. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Surprising Coordination Geometry Differences in CeIV‐ and PuIV‐Maltol Complexes
Authors: Szigethy Géza , Xu Jide , Gorden Anne E. V. , Teat Simon J. , Shuh David K. , Raymond Kenneth N. 
Published: March 2008

AbstractAs part of a study to characterize the detailed coordination behavior of PuIV, single‐crystal X‐ray diffraction structures have been determined for PuIV and CeIV complexes with the naturally occurring ligand maltol (3‐hydroxy‐2‐methylpyran‐4‐one) and its derivative bromomaltol (5‐bromo‐3‐hydroxy‐2‐methylpyran‐4‐one). Although CeIV is generally accepted as a structural analog for PuIV, and the maltol complexes of these two metals are isostructural, the corresponding bromomaltol complexes are strikingly different with respect to ligand orientation about the metal ion: All complexes exhibit trigonal dodecahedral coordination geometry but the CeIV–bromomaltol complex displays an uncommon ligand arrangement not found in the PuIV complex.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
H‐Ras increases urokinase expression and cell invasion in genetically modified human astrocytes through Ras/Raf/MEK signaling pathway
Authors: Zhao Yunge , Xiao Aizhen , Dipierro Charles G. , Abdel‐Fattah Rana , Amos Samson , Redpath Gerard T. , Carpenter Joan E. , Pieper Russell O. , Hussaini Isa M. 
Published: March 2008

AbstractPrevious study reported that the activation of Ras pathway cooperated with E6/E7‐mediated inactivation of p53/pRb to transform immortalized normal human astrocytes (NHA/hTERT) into intracranial tumors strongly resembling human astrocytomas. The mechanism of how H‐Ras contributes to astrocytoma formation is unclear. Using genetically modified NHA cells (E6/E7/hTERT and E6/E7/hTERT/Ras cells) as models, we investigated the mechanism of Ras‐induced tumorigenesis. The overexpression of constitutively active H‐RasV12 in E6/E7/hTERT cells robustly increased the levels of urokinase plasminogen activator (uPA) mRNA, protein, activity and invasive capacity of the E6/E7/hTERT/Ras cells. However, the expressions of MMP‐9 and MMP‐2 did not significantly change in the E6/E7/hTERT and E6/E7/hTERT/Ras cells. Furthermore, E6/E7/hTERT/Ras cells also displayed higher level of uPA activity and were more invasive than E6/E7/hTERT cells in 3D culture, and formed an intracranial tumor mass in a NOD‐SCID mouse model. uPA specific inhibitor (B428) and uPA neutralizing antibody decreased uPA activity and invasion in E6/E7/hTERT/Ras cells. uPA‐deficient U‐1242 glioblastoma cells were less invasive in vitro and exhibited reduced tumor growth and infiltration into normal brain in xenograft mouse model. Inhibitors of Ras (FTA), Raf (Bay 54‐9085) and MEK (UO126), but not of phosphatidylinositol 3‐kinase (PI3K) (LY294002) and of protein kinase C (BIM) pathways, inhibited uPA activity and cell invasion. Our results suggest that H‐Ras increased uPA expression and activity via the Ras/Raf/MEK signaling pathway leading to enhanced cell invasion and this may contribute to increased invasive growth properties of astrocytomas. © 2008 Wiley‐Liss, Inc.
Statin treatment of adult human glial progenitors induces PPARγ‐mediated oligodendrocytic differentiation
Authors: Sim Fraser J. , Lang Jennifer K. , Ali Tracy A. , Roy Neeta S. , Vates G. Edward , Pilcher Webster H. , Goldman Steven A. 
Published: March 2008

AbstractThe statins have been proposed as possible therapeutic agents for a variety of autoimmune disorders, including multiple sclerosis. In a genomic screen, we found that glial progenitor cells (GPCs) of the adult human white matter expressed significant levels of the principal statin target, HMG‐CoA reductase, as well as additional downstream members of the sterol synthesis pathway. We therefore asked if statin treatment might influence the differentiated fate of adult glial progenitor cells. To assess the functional importance of the sterol synthesis pathway to adult human glial progenitors, we used simvastatin or pravastatin to inhibit HMG‐CoA reductase, and then assessed the phenotypic differentiation of the progenitors, as well as the molecular concomitants thereof. We found that both statins induced a dose‐dependent induction of oligodendrocyte phenotype, and concomitant reduction in progenitor number. Oligodendrocyte commitment was associated with induction of the sterol‐regulated nuclear co‐receptor PPARγ, and could be blocked by the specific PPARγ antagonist GW9662. Thus, statins may promote oligodendrocyte lineage commitment by parenchymal glial progenitor cells; this might reduce the available progenitor pool, and hence degrade the long‐term regenerative competence of the adult white matter. © 2008 Wiley‐Liss, Inc.
Facile synthesis of phosphorylated azides in ionic liquids and their use in the preparation of 1,2,3‐triazoles
Authors: Artyushin Oleg I. , Vorob'eva Daria V. , Vasil'eva Tamara P. , Osipov Sergey N. , Röschenthaler Gerd‐Volker , Odinets Irina L. 
Published: April 2008

AbstractThe facile general synthetic route to azidoalkylphosphonates by the nucleophilic substitution reaction in a series of bromoalkylphosphonates was elaborated, using 1‐butyl‐3‐methylimidazolium hexafluorophosphate ([bmim][PF6]) as a recyclable reaction medium. These azidoalkylphosphonates were used as intermediates for copper(I)‐catalyzed regioselective 1,3‐dipolar cycloaddition with a variety of alkynes to afford 4‐substituted (1H‐1,2,3‐triazol‐1‐yl)alkylphosphonates as potential drug candidates. © 2008 Wiley Periodicals, Inc. Heteroatom Chem 19:293–300, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20420