bluuebunny/crossref_metadata_2025_split huggingface dataset:
Syntheses and Phase‐Transfer Properties of Dendritic Nanocarriers That Contain Perfluorinated Shell Structures
Authors: Garcia‐Bernabé Abel , Krämer Michael , Olàh Bèla , Haag Rainer 
Published: April 2004

AbstractPerfect dendrimers that contain perfluorinated shells have recently attracted attention because they have been shown to encapsulate polar molecules in supercritical CO2 and catalytically active metal nanoparticles in perfluorinated solvents. Moreover, they can then be easily separated after reaction from the biphasic organic/fluorous system. In this paper several dendritic architectures that contain perfluorinated shells were derived by covalent modification of glycerol dendrimers ([G0.5]–[G3.5]), hyperbranched polyglycerol, and polyethyleneimine. These core‐shell architectures show interesting physicochemical properties. For example, they are soluble in fluorinated solvents, they are able to transport different guest molecules, and they display thermomorphic behavior. The transport capacity of these molecular nanocarriers increases significantly when amino groups are present in the core. Certain functionalized polyethyleneimines that contain perfluorinated shells show high transport capacities (up to 3 dye molecules per nanocarrier) in perfluorinated solvents. Moreover, these perfluoro‐functionalized dendritic polyethyleneimines can act as templates that stabilize nanoparticles; for example, encapsulation and subsequent chemical reduction of AgI ions. Silver nanoparticles with a narrow size distribution (3.9±1 nm) have been prepared and characterized by transmission electron microscopy. Furthermore, it has been demonstrated that the encapsulated guest molecules remain accessible to small molecules after transport into the fluorous phase. Therefore, dendritic nanocarriers that contain perfluorinated shells are currently being investigated as polar environments in nonpolar reaction media such as fluorous phases and supercritical CO2, in particular, for application in homogenous catalysis.
The Role of Hydrogen Bonding in the Crystal Structures of Zinc Phosphate Hydrates
Authors: Herschke Laurent , Enkelmann Volker , Lieberwirth Ingo , Wegner Gerhard 
Published: April 2004

AbstractThe compounds α‐ and β‐hopeite have been synthesised by hydrothermal crystallisation from aqueous solution at 90 °C and 20 °C, respectively. The crystal structures of these polymorphic forms of zinc phosphate tetrahydrate (ZPT), Zn3(PO4)2⋅4 H2O, have been resolved. Single‐crystal analysis proves that the main difference between the α and β forms of ZPT is caused by the difference in orientation of one of the water molecules in the ZnO6 octahedral network, indicating two different hydrogen‐bonding patterns. A previously unknown hopeite, Zn3(HPO4)3⋅3 H2O (ZHPT), has been isolated and analysed. This helps to achieve a better understanding of the mechanism of formation of zinc phosphate compounds. Unambiguous identification of each phase is established by analysis of their unique thermal behaviour and thermodynamic interrelationship.
Nonlinear Heat Transport in Anisotropic Divertor Targets Irradiated by Laser Pulses
Authors: Bachmann P. , Hildebrandt D. , Sünder D. 
Published: April 2004

AbstractIn order to derive plasma energy outflux from thermographic measurements an inverse heat conduction problem must be solved. A solution method for the time‐dependent three‐dimensional heat conduction equation is presented which improves an analytical Green's function solution by a numerical iteration method to include nonlinear effects. The measured temperature excursion of a graphite surface irradiated by laser heat flux pulses can be well described by the model calculations. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Incorporating Line Radiation Effects into Edge Plasma Codes
Authors: Scott Howard A. , Adams Mark L. 
Published: April 2004

AbstractStrong hydrogen line radiation can significantly affect the ionization and energy balance in high‐density, lowtemperature edge plasmas. A fully self‐consistent one‐dimensional simulation code integrating line radiation with edge plasma transport has recently been demonstrated. This code allows us to evaluate the use of approximate treatments of radiation effects that could potentially be incorporated into existing two‐dimensional edge plasma codes. For a given approximation, we tabulate effective ionization, recombination and energy loss rates for hydrogen plasmas in a one‐dimensional geometry as a function of electron density, temperature and position. The position is a simple parameterization corresponding to optical depth, with the correspondence dependent on plasma properties, including magnetic field. The parameterized values can differ by more than an order of magnitude from the optically thin values.We present one‐dimensional edge plasma simulations using the parameterized tables and compare them to self‐consistent simulations to investigate the validity of this approach, the effectiveness of the parameterization and the accuracy of the approximations used. We also present results using parameterized tables in a twodimensional code and discuss the validity of applying them in this manner. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
3D Edge Modeling and Island Divertor Physics
Authors: Feng Y. , Sardei F. , Kisslinger J. , Grigull P. , McCormick K. , Reiter D. 
Published: April 2004

AbstractThe paper presents an overview on the state of the art of 3D fluid transport modeling in the boundaries of 3D toroidal confinement devices and on applications to island divertor physics. Typically, such edge configurations are characterized by the coexistence of closed magnetic surfaces, islands and open stochastic regions, e.g. in helical devices like W7‐AS, W7‐X, LHD and in tokamaks like TEXTOR‐DED. Two main approach branches falling within the current numeric catalogue of the 3D modeling are the finite volume andMonte Carlo methods. They differ essentially in the elementary treatment of the local transport. While in a finite volume method interpolation of the fluid fluxes through the interfaces by appropriate choice of a shape function is essential for the discretization process, the full fluid dynamics are, in a Monte Carlo approach, simulated by means of a local stochastic process, with the fluxes passing through cell boundary surfaces being a net result of the random process. In this paper, we present the numerics and strategies proposed in different models. Concerning the practical applications to a realistic 3D experiment, W7‐AS provides not only a practical fully 3D island divertor configuration but also sufficient experimental data for code validation. We present the main simulation results from the 3D edge Monte Carlo code EMC3/EIRENE and discuss the island divertor physics with respect to tokamak divertors. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Drift‐ordered fluid equations for modelling collisional edge plasma
Authors: Simakov A. N. , Catto P. J. 
Published: April 2004

AbstractThe fluid description of collisional magnetized plasma by Braginskii is based on an ordering assuming the species flow velocities to be on the order of the ion thermal speed. This large flow assumption is normally not valid for plasma fusion devices in general and tokamak edge plasmas in particular. To remove this shortcoming Mikhailovskii and Tsypin developed a plasma fluid description assuming the flow velocities to be on the order of the diamagnetic drift velocities, which are smaller than the ion thermal speed. However, when deriving their equations Mikhailovskii and Tsypin missed important terms in their expressions for the species collisional viscous stress tensors. Starting from corrected Mikhailovskii‐Tsypin fluid equations, we derive a system of non‐linear reduced equations describing field‐aligned fluctuations in low‐beta collisional magnetized edge plasma; namely, equations for plasma density, electron and ion energies (or, equivalently, temperatures), parallel ion flow velocity, parallel current, vorticity (or, equivalently, electrostatic potential), perturbed parallel electromagnetic potential, and perturbed magnetic field. Our equations locally conserve particle number and total energy, and insure that perturbed magnetic field and total plasma current are divergence‐free. In addition, while intended primarily for modelling plasma turbulence, they contain the neoclassical results for plasma current, parallel ion flow velocity, and parallel gradients of equilibrium electron and ion temperatures. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Reconstruction of Velocity Distribution of Density Bursts by Wavelet Analysis in the Linear Divertor Simulator NAGDIS‐II
Authors: Ohno N. , Budaev V. P. , Furuta K. , Miyoshi H. , Takamura S. 
Published: April 2004

AbstractWe have investigated the velocity distribution of the intermittent bursty fluctuations in the ion saturation currents observed in the linear divertor plasma simulator, NAGDIS‐II. The intermittent bursty signals were analyzed by the wavelet transform with complex Morlet mother wavelet. Analyzing a lot of bursts in the ion saturation currents based on the wavelet cross‐correlation gives the velocity distribution function. It is positively skewed at the peripheral region of the plasma column, which means the intermittent bursts mainly propagate toward the wall. The averaged velocity depends on the neutral pressure associated with the transition between the attached and detached plasmas. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Multi‐fluid code simulation of DIII‐D filterscope data including reflection of light from plasma‐facing surfaces
Authors: Hollmann E. M. , Pigarov A. Yu. 
Published: April 2004

AbstractA comparison is made between solutions of the UEDGE multi‐fluid edge code and the full array of 24 poloidal and tangential Dα and CIII filterscope views available in DIII‐D for a lower single null L‐mode discharge. Wall reflections are included using measured graphite tile reflection data together with a 3D ray tracing code. It is found that divertor view chords are relatively unperturbed by reflections, while main chamber views can be dominated by reflected light. Main chamber view chords are shown to be important in distinguishing between different radial transport models: a hybrid model including both convection and diffusion is found to match measured main chamber Dα brightnesses well, while a pure diffusive model gives brightnesses which are of order 100× too small. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Comparative expression analysis of the MAGED genes during embryogenesis and brain development
Authors: Bertrand Mathieu , Huijbers Ivo , Chomez Patrick , De Backer Olivier 
Published: April 2004

AbstractThe MAGED gene subfamily contains three genes in mouse and four in human. The MAGED1, D2, and D3 proteins are highly conserved between mouse and human, whereas paralogues are less conserved between each other. This finding suggests that each MAGED protein exerts a distinct function. To get a better insight into their physiological roles, we have analyzed their expression patterns during embryogenesis and brain development. In the mouse, Maged3 expression is restricted to the central nervous system where it was mostly detected in postmitotic neurons. Maged2 is mainly expressed in tissues of mesodermal origin. The expression pattern of Maged1 roughly summarizes that of Maged2 and Maged3; however, contrary to that of Maged3, it includes the proliferative zones of the nervous system. We observed a discrepancy between Maged1 expression levels of RNA and protein, suggesting that its expression is regulated at a posttranscriptional level during the mouse development. Developmental Dynamics 230:325–334, 2004. © 2004 Wiley‐Liss, Inc.
Follistatin operates downstream of Wnt4 in mammalian ovary organogenesis
Authors: Yao Humphrey H.C. , Matzuk Martin M. , Jorgez Carolina J. , Menke Douglas B. , Page David C. , Swain Amanda , Capel Blanche 
Published: April 2004

AbstractWnt4‐/‐ XX gonads display features normally associated with testis differentiation, suggesting that WNT4 actively represses elements of the male pathway during ovarian development. Here, we show that follistatin (Fst), which encodes a TGFβ superfamily binding protein, is a downstream component of Wnt4 signaling. Fst inhibits formation of the XY‐specific coelomic vessel in XX gonads. In addition, germ cells in the ovarian cortex are almost completely lost in both Wnt4 and Fst null gonads before birth. Thus, we propose that WNT4 acts through FST to regulate vascular boundaries and maintain germ cell survival in the ovary. Developmental Dynamics 230:210–215, 2004. © 2004 Wiley‐Liss, Inc.
Functional knockdown of neuropilin‐1 in the developing chick nervous system by siRNA hairpins phenocopies genetic ablation in the mouse
Authors: Bron Romke , Eickholt Britta J. , Vermeren Matthieu , Fragale Ninfa , Cohen James 
Published: April 2004

AbstractThe chick embryo is widely used for the study of vertebrate development, but a general, reliable loss‐of‐function strategy for the analysis of gene function is currently not available. By using small inhibitory hairpin RNA (siRNA) molecules generated by the mouse U6 promoter, we have applied an RNA interference approach to achieve quantitative knockdown of the neuropilin‐1 (Nrp‐1) receptor in chick embryos. Functional knockdown was evident in the abolition of Sema3A‐induced growth cone collapse in Nrp‐1‐siRNA but not Nrp‐2‐siRNA–expressing dorsal root ganglion (DRG) neurons. Two nervous system defects in Nrp‐1 mutant mice were phenocopied in embryos treated with Nrp‐1 siRNA. First, DRG axons prematurely entered the dorsal horn and projected inappropriately. Second, targeted early migrating neural crest cells destined for the sympathetic chain arrested ectopically within ventral spinal nerve roots. Localized knockdown induced by specific siRNA constructs will allow rapid functional analysis of genes regulating chick neural development whilst circumventing embryonic lethal effects often associated with global gene knockout in the mouse. Developmental Dynamics 230:299–308, 2004. © 2004 Wiley‐Liss, Inc.
Slit and robo expression in the developing mouse lung
Authors: Greenberg James M. , Thompson Felisa Y. , Brooks Sherry K. , Shannon John M. , Akeson Ann L. 
Published: April 2004

AbstractMammalian lung development is mediated through complex interactions between foregut endoderm and surrounding mesenchyme. As airway branching progresses, the mesenchyme undergoes dramatic remodeling and differentiation. Little is understood about the mechanisms that direct mesenchymal organization during lung development. A screen for candidate genes mediating this process identified Slit, a ligand for the Roundabout (Robo) receptor previously associated with guidance of axonal projections during central nervous system development. Here, we demonstrate by in situ hybridization that two Slit genes (Slit‐2 and Slit‐3) and two Robo genes (Robo‐1 and Robo‐2) are expressed in fetal lung mesenchyme. Slit‐2 and Robo‐1 expression is present throughout mesenchyme at midgestation and is not detectable by newborn day 1. Slit‐3 and Robo‐2 expression is restricted to specific, complementary subsets of mesenchyme. Robo‐2 is expressed in mesenchymal cells immediately adjacent to large airways, whereas Slit‐3 expression predominates in mesenchyme remote from airway epithelium. The temporal and spatial distribution of Slit and Robo mRNAs indicate that these genes may direct the functional organization and differentiation of fetal lung mesenchyme. Developmental Dynamics 230:350–360, 2004. © 2004 Wiley‐Liss, Inc.
Twist is required for patterning the cranial nerves and maintaining the viability of mesodermal cells
Authors: Ota Masato S. , Loebel David A.F. , O'Rourke Meredith P. , Wong Nicole , Tsoi Bonny , Tam Patrick P.L. 
Published: April 2004

AbstractTwist encodes a basic helix‐loop‐helix transcription factor that is required for normal craniofacial morphogenesis in the mouse. Loss of Twist activity in the cranial mesenchyme leads to aberrant migratory behaviour of the neural crest cells, whereas Twist‐deficient neural crest cells are located in an inappropriate location in the first branchial arch and display defective osteogenic and odontogenic differentiation (Soo et al. [2002] Dev. Biol. 247:251–270). Results of the present study further show that loss of Twist impacts on the patterning of the cranial ganglia and nerves but not that of the peripheral ganglia and nerves in the trunk region of the body axis. Analyses of the expression of molecular markers of early differentiation of the paraxial mesoderm and the histogenetic potency of somites of Twist‐/‐ embryos reveal that Twist‐deficient somites can differentiate into muscles, cartilage, and bones, albeit less prolifically. Twist function, therefore, is not essential for mesoderm differentiation. The poor growth of the Twist‐deficient somites after transplantation to the ectopic site may be attributed to reduced proliferative capacity and extensive apoptosis of the paraxial mesoderm, suggesting that Twist is required for maintaining cell proliferation and viability in the mesodermal progenitors. Developmental Dynamics 230:216–228, 2004. © 2004 Wiley‐Liss, Inc.
Kinematics and strain partitioning in the southeast Hellenides (Greece)
Authors: Kokkalas S. , Doutsos T. 
Published: April 2004

AbstractNew kinematic and structural data from the tectonic windows of eastern Crete and the Dodecanese Islands combined with strain and quartz fabric analysis have enabled us to determine a detailed structural evolution of the region and to present a plate tectonic scenario for the southeast Hellenides.During the Early Mesozoic, the southeastern part of Apulia was separated from North Africa and the adjacent microplates by WNW‐trending rift zones and NE‐trending transfer faults. Displacement along the transfer faults has locally reoriented these rift zones into an ENE–WSW direction. Finite strain and quartz fabric asymmetry data indicate that in Late Cenozoic time, NNW‐directed nappe movements caused a nearly coaxial deformation along the ENE–WSW trending rift segments and non coaxial top‐to‐the‐southeast shearing along the WNW‐trending rift segments, as well as along the pre‐existing NE‐trending transfer faults. Tectonic style along the margin varies in response to the obliquity of the principal shortening direction with respect to the margin. These variations could be due to the pre‐convergence geometry of the southern margin of Eurasia and to local strain partitioning effects.Furthermore, a tectonic model is presented in which syncompressional uplift and vertical buoyancy of the subducted crustal slice caused the rapid exhumation of metamorphic units in the south Hellenides. Copyright © 2003 John Wiley & Sons, Ltd.
Characterization of the actions of AvTx 7 isolated from Agelaia vicina (Hymenoptera: Vespidae) wasp venom on synaptosomal glutamate uptake and release
Authors: Pizzo Andrea B. , Beleboni Renê O. , Fontana Andréia C. K. , Ribeiro Alessandra M. , Miranda Antonio , Coutinho‐Netto Joaquim , dos Santos Wagner F. 
Published: April 2004

AbstractIt has previously been shown that the denatured crude extract of Agelaia vicina wasp venom inhibits glutamate and GABA uptake in rat cerebral cortex synaptosomes. To identify the components responsible for these effects, the neurotoxin AvTx 7 (molecular weight of 1210 Da) was isolated from A. vicina venom and its effects on glutamate neurotransmission investigated. AvTx 7 inhibits glutamate uptake in a dose‐dependent and uncompetitive manner. AvTx 7 was found to stimulate the glutamate release in the presence of calcium and sodium channel blockers, suggesting that its action is not mediated through these channels. AvTx 7 potentiates glutamate release in the presence of K+ channel blockers tetraethylammonium and 4‐aminopyridine, indicating that the toxin may act through these drugs‐sensible K+ channels. We suggest that AvTx 7 can be a valuable tool to enhance our understanding of K+ channels' involvement in the release of glutamate. © 2004 Wiley Periodicals, Inc. J Biochem Mol Toxicol 18:61–68, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/jbt.20014
Analysis of an early‐onset Parkinson's disease cohort for DJ‐1 mutations
Authors: Clark Lorraine N. , Afridi Shehla , Mejia‐Santana Helen , Harris Juliette , Louis Elan D. , Cote Lucien J. , Andrews Howard , Singleton Andrew , Wavrant De‐Vrieze Fabienne , Hardy John , Mayeux Richard , Fahn Stanley , Waters Cheryl , Ford Blair , Frucht Steven , Ottman Ruth , Marder Karen 
Published: April 2004

AbstractThe frequency and relative contribution of DJ‐1 mutations in early‐onset Parkinson's disease (EOPD) is currently unknown. We analyzed a cohort of 89 EOPD patients (mean age at onset of PD ± SD, 41.5 ± 7.2 years), ascertained independent of family history, who participated in a study of the genetic epidemiology of PD. This study includes sequence analysis of the DJ‐1 gene in addition to assaying the 14,082‐bp deletion spanning exons 1 to 5, previously identified in a Dutch kindred, in 89 EOPD cases. A heterozygous missense mutation in exon 5 (A104T) was identified in an EOPD case of Asian ethnicity; this sequence variant was absent in 308 control chromosomes. We identified additional sequence variation in the DJ‐1 gene, including a polymorphism in the coding region in exon 5 (R98Q), three polymorphisms in the 5′ untranslated region (exon 1A/1B), and two polymorphisms in intronic regions (IVS1 and IVS5). Mutations in the DJ‐1 gene are rare in EOPD in both sporadic and familial cases. © 2004 Movement Disorder Society
Properties of Xenopus Kv1.10 channels expressed in HEK293 cells
Authors: Fry Mark , Maue Robert A. , Moody‐Corbett Frances 
Published: April 2004

AbstractVoltage‐gated K+ channels play important roles in shaping the characteristics of action potentials and electrical activity. In a previous study, we isolated cDNAs encoding several distinct K+ channel isoforms, including a novel isoform (XKv1.10) expressed in Xenopus laevis spinal cord neurons and myocytes. Here, we report the biophysical characterization of XKv1.10 expressed in transiently transfected HEK293 cells. Whole cell patch clamp recordings revealed a voltage‐gated, rapidly activating and inactivating K+ current. Interestingly, the rate of inactivation of XKv1.10 channels showed apparent voltage dependence, with time constants between 77.7–213.3 ms. The predicted protein sequence of XKv1.10 does not appear to encode an N‐terminal inactivating “ball and chain” domain, and instead these channels may inactivate via a C/P‐type mechanism. Consistent with this, either increasing the external concentration of K+ or external application of tetraethylammonium caused a decrease in the rate of inactivation. Pharmacologically, XKv1.10 K+ channels were sensitive to 4‐aminopyridine and tetraethylammonium with apparent IC50 values of 68.5 μM and 17.1 mM, respectively. When simulated action potentials were used as a voltage command, XKv1.10 was similar to XKv1.4 in that it carried more repolarizing current during the action potential than XKv1.2. However, while XKv1.4 was active during the interspike interval, XKv1.10 and XKv1.2 were not. Overall, the data suggest that XKv1.10 channels make a unique contribution to the developmental maturation of electrical signaling in Xenopus laevis. © 2004 Wiley Periodicals, Inc. J Neurobiol 60: 227–235, 2004
Measuring autonomy in social security agencies: a four country comparison
Authors: Caulfield Janice L. 
Published: April 2004

AbstractMany European countries manage social policy programmes through autonomous organisations. This article examines the role of these agencies in four countries, two of which (Sweden and Finland) have long histories of using agencies and two (the Netherlands and the United Kingdom) in which this style of management is more recent. The article focuses particular attention on the use of performance management in the context of devolved organisations. Copyright © 2004 John Wiley & Sons, Ltd.