bluuebunny/crossref_metadata_2025_split huggingface dataset:
Towards Targeted MRI: New MRI Contrast Agents for Sialic Acid Detection
Authors: Frullano Luca , Rohovec Jan , Aime Silvio , Maschmeyer Thomas , Prata M. Isabel , de Lima J. J. Pedroso , Geraldes Carlos F. G. C. , Peters Joop A. 
Published: September 2004

AbstractThe detection of sialic acid in living systems is of importance for the diagnosis of several types of malignancy. We have designed and synthesized two new lanthanide ion ligands (L1 and L2) that are capable of molecular recognition of sialic acid residues. The basic structure of these ligands consists of a DTPA‐bisamide (DTPA, diethylenetriamine pentaacetic acid) whose amide moieties each bear both a boronic function for interaction with the diol groups in the side chain of sialic acid, and a functional group that is positively charged at physiologic pH values and is designed to interact with the carboxylate anion of sialic acid. The relaxometric properties of the Gd3+ complexes of these two ligands were evaluated. The relaxivity of the GdL1 complex has a significant second‐sphere contribution at pH values above the pKa of its phenylboronic acid moiety. The interaction of the Gd3+ complexes of L1 and L2 with each of several saccharides was investigated by means of a competitive fluorescent assay. The results show that both complexes recognize sialic acid with good selectivity in the presence of other sugars. The adduct formed by GdL2 with sialic acid has the higher conditional formation constant (50.43±4.61 M−1 at pH 7.4). The ability of such complexes to recognize sialic acid was confirmed by the results of a study on the interaction of corresponding radiolabeled complexes (153SmL1 and 153SmL2) with C6 glioma rat cells. 153SmL2 in particular is retained on the cell surface in significant amounts.
Compressed Octahedral Coordination in Chain Compounds Containing Divalent Copper: Structure and Magnetic Properties of CuFAsF6 and CsCuAlF6
Authors: Mazej Zoran , Arčon Iztok , Benkič Primož , Kodre Alojz , Tressaud Alain 
Published: September 2004

AbstractCrystal structures and magnetic investigations of CuFAsF6 and CsCuAlF6 are reported. Together with KCuAlF6, these appear to be the only examples of Jahn–Teller pure CuII compounds containing only one type of ligand that exhibits a compressed octahedral coordination geometry. The Rietveld method has been used for refining the CsCuAlF6 structure based on neutron powder diffraction data at 4 K. The compound crystallizes in space group Pnma (no. 62) with a=7.055(1), b=7.112(1), c=10.153(1) Å and Z=4 at 4 K. The structure is built from infinite [CuF5]n3n− chains of [CuF6]4− octahedra running along the [1 0 0] direction and (AlF6)3− octahedra connected by corners in the trans position, thus giving rise to chains oriented along the [0 1 0] direction. Single crystals of CuFAsF6 were prepared under solvothermal conditions in AsF5 above its critical temperature. The structure was determined from single‐crystal data. CuFAsF6 crystallises in the orthorhombic space group Imma (No. 74) with a=10.732(5), b=6.941(3), c=6.814(3) Å and Z=4 at 200 K. The structure can also be described in terms of one‐dimensional infinite [CuF5]n3n− chains of tilted [CuF6]4− octahedra linked by trans‐vertices running along the b axis. The [CuF5]n3n− chains are connected through [AsF6]− units sharing joint vertices. The compressed octahedral coordination of CuII atoms in CuFAsF6 and CsCuAlF6 compounds at room temperature is confirmed by Cu K‐edge EXAFS (extended x‐ray absorption fine structure) analysis. For both compounds strong antiferromagnetic interactions within the [CuF5]n3n− chains were observed (θp=−290±10 K and θp=−390±10 K for CuFAsF6 and CsCuAlF6, respectively). The peculiar magnetic behaviour of chain compounds containing divalent copper at low temperature could be related to uncompensated magnetic moments in the one‐dimensional network.
The Reaction of [FeII(tpa)] with H2O2 in Acetonitrile and Acetone—Distinct Intermediates and Yet Similar Catalysis
Authors: Mairata i Payeras Antoni , Ho Raymond Y. N. , Fujita Megumi , Que, Lawrence 
Published: September 2004

AbstractThe reaction of [FeII(tpa)(OTf)2] (tpa=tris(2‐pyridylmethyl)amine) and its related 5‐Me3‐tpa complex with hydrogen peroxide affords spectroscopically distinct iron(III)–peroxo intermediates in CH3CN and acetone. The reaction in acetonitrile at −40 °C results in the formation of the previously reported FeIII–OOH intermediate, the end‐on hydroperoxo coordination mode of which is established in this paper by detailed resonance Raman isotope‐labeling experiments. On the other hand, the reaction in acetone below −40 °C leads to the observation of a different peroxo intermediate identified by resonance Raman spectroscopy to be an FeIII–OOC (CH3)2OH species; this represents the first example of an intermediate derived from the adduct of H2O2 and acetone. The peroxoacetone intermediate decays more rapidly than the corresponding FeIII–OOH species and converts to an FeIVO species by OO bond homolysis. This decay process is analogous to that observed for [FeIII(tpa)(OOtBu)]2+ and in fact exhibits a comparable enthalpy of activation of 54(3) kJ mol−1. Thus, with respect to their physical properties at low temperature, the peroxoacetone intermediate resembles [FeIII(tpa)(OOtBu)]2+ more than the corresponding FeIII–OOH species. At room temperature, however, the behavior of the Fe(tpa)/H2O2 combination in acetone in catalytic hydrocarbon oxidations differs significantly from that of the Fe(tpa)/tBuOOH combination and more closely matches that of the Fe(tpa)/H2O2 combination in CH3CN. Like the latter, the Fe(tpa)/H2O2 combination in acetone catalyzes the hydroxylation of cis‐1,2‐dimethylcyclohexane to its tertiary alcohol with high stereoselectivity and carries out the epoxidation and cis‐dihydroxylation of olefins. These results demonstrate the subtle complexity of the Fe(tpa)/H2O2 reaction surface.
Ortho‐Chalcogenostannates as Ligands: Syntheses, Crystal Structures, Electronic Properties, and Magnetism of Novel Compounds Containing Ternary Anionic Substructures [M4(μ4‐Se)(SnSe4)4]10− (M=Mn, Zn, Cd, Hg), ${{{\hfill 3\atop \hfill \infty }}}${[Hg4(μ4‐Se)(SnSe4)3]6−}, or ${{{\hfill 1\atop \hfill \infty }}}${[HgSnSe4]2−}
Authors: Brandmayer Michael K. , Clérac Rodolphe , Weigend Florian , Dehnen Stefanie 
Published: September 2004

AbstractBy reaction of K4[SnSe4]⋅1.5 MeOH with CdCl2 or Hg(OAc)2 in water/methanol it was possible to prepare single crystals of four novel compounds that contain ternary anionic coordination oligomers and polymers: [K10(H2O)16(MeOH)0.5][M4(μ4‐Se)(SnSe4)4] (4: M=Cd, 5: M=Hg), [K6(H2O)3][Hg4(μ4‐Se)(SnSe4)3]⋅MeOH (6), and K2[HgSnSe4] (7), which were structurally characterized by single‐crystal X‐ray diffraction. The optical absorption properties of the isostructural compounds 4 and 5, as well as those of the recently reported Zn (2) and Mn (3) analogues, were studied by UV‐visible spectroscopy. These investigations showed the quaternary phases to have relatively small optical gaps for their molecular size (2.2–2.6 eV), which are similar to the excitation energies that were observed for mesostructured solids of the respective combination of elements. According to DFT investigations on the ternary anions, an experimentally observed difference between the absorption behavior of the d10 compounds 2, 4, and 5 and the open‐shell d5 compound 3 is in line with different characters of the frontier orbitals in the two cases. Both the calculations and a magnetic measurement on 3 demonstrated antiferromagnetic coupling between the μ4‐Se‐bridged Mn centers.
A Simple, Efficient and Regioselective Oxychlorination of Aromatic Compounds Using Ammonium Chloride and Oxone®.
Authors: Narender N. , Mohan K. V. V. Krishna , Srinivasu P. , Kulkarni S. J. , Raghavan K. V. 
Published: September 2004

AbstractFor Abstract see ChemInform Abstract in Full Text.
Genomic analysis of prostate carcinoma specimens obtained via ultrasound‐guided needle biopsy may be of use in preoperative decision‐making
Authors: Teixeira Manuel R. , Ribeiro Franclim R. , Eknæs Mette , Wæhre Håkon , Stenwig Anna E. , Giercksky Karl E. , Heim Sverre , Lothe Ragnhild A. 
Published: September 2004

AbstractBACKGROUNDThe widespread use of prostate‐specific antigen (PSA) testing to screen for prostate carcinoma has led to significant overdiagnosis, due to the frequent detection of indolent malignancies on PSA screening. The detection of abnormal PSA levels typically is followed by ultrasound‐guided needle biopsy. Therefore, in an effort to identify genetic markers that augment the information provided by standard histopathologic classification, the authors tested the feasibility of using these minute biopsy samples for genomic profiling via chromosome banding analysis and comparative genomic hybridization (CGH).METHODSUltrasound‐guided needle biopsy specimens obtained preoperatively from 35 patients with prostate carcinoma were analyzed via chromosome banding analysis (after short‐term culturing) and CGH. The findings of these analyses then were analyzed for potential correlations with clinicopathologic parameters.RESULTSChromosome banding analysis and CGH were possible in 34 and 33 of the 35 study specimens, respectively. Combined analysis revealed aberrations in 69% of all samples investigated. Copy number losses occurred most commonly at 8p (58% of all abnormal specimens), 16q (42%), and 13q (37%), whereas the only gains detected in more than 1 specimen were those that occurred at 8q (37%). Genomic imbalances and losses at 16q were significantly associated with more poorly differentiated subtypes of prostate carcinoma (P = 0.048 and P = 0.019, respectively), whereas gains at 8q and losses at 16q were significantly correlated with clinically advanced disease (P = 0.048 for the finding of a gain at 8q together with a loss at 16q; P = 0.01 for the finding of either aberration alone).CONCLUSIONSThe authors conclude that genomic analysis of suspected prostate carcinoma specimens obtained via ultrasound‐guided needle biopsy is feasible. Thus, it may be possible to use genetic markers to obtain diagnostic and/or prognostic information that is useful in the making of preoperative decisions regarding prostate carcinoma management. Cancer 2004. © 2004 American Cancer Society.
Growth of bismuth tri‐iodide platelets by the physical vapor deposition method
Authors: Cuña A. , Noguera A. , Saucedo E. , Fornaro L. 
Published: September 2004

AbstractThe work reports the growth of single BI3 crystals with platelets habit. Platelets were grown by physical vapor deposition (PVD) in a high vacuum atmosphere and with argon, polymer or iodine as additives. Crystals grew in the zone of maximum temperature gradient, perpendicular to the ampoule wall. Crystals grown with argon as additive show a very shining surface, have hexagonal (0 0 l) faces, sizes up to 20 x 10 mm2 and thicknesses up to 100 μm. They were characterized by optical microscopy and scanning electron microscopy (SEM). Dendritic‐like structures were found to be their main surface defect. SEM indicates that they grow from the staking of hexagonal unities. Electrical properties of the crystals grown under different growth conditions were determined. Resistivities up to 2 x 1012 Ωcm (the best reported value for monocrystals of this material) were obtained. X‐ray response was measured by irradiation of the platelets with a 241Am source of 3.5 mR/h. A comparison of results according to the growth conditions was made. Properties of the crystals grown by this method are compared with the ones measured for others previously grown from the melt. Also, results for bismuth tri‐iodide platelets are compared with the ones obtained for mercuric and lead iodide platelets. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
How can SMEs effectively implement the CSR agenda? A UK case study perspective
Authors: Castka Pavel , Balzarova Michaela A. , Bamber Christopher J. , Sharp John M. 
Published: September 2004

AbstractThis paper focuses on implementation of the CSR agenda in small‐to‐medium enterprises (SMEs) and reports on research findings from an action research case study that has been conducted in a UK based SME. The case study research demonstrates how the CSR agenda has been implemented using ISO 9001:2000 as a platform and what benefits the case study organization has gained from this approach. These results are compared with a UK survey on feasibility of CSR for SMEs conducted by the UK's Department of Trade and Industry and parallels are drawn. Copyright © 2004 John Wiley & Sons, Ltd and ERP Environment.
Neuromorphic architectures for nanoelectronic circuits
Authors: Türel Özgür , Lee Jung Hoon , Ma Xiaolong , Likharev Konstantin K. 
Published: September 2004

AbstractThis paper reviews recent important results in the development of neuromorphic network architectures (‘CrossNets’) for future hybrid semiconductor/nanodevice‐integrated circuits. In particular, we have shown that despite the hardware‐imposed limitations, a simple weight import procedure allows the CrossNets using simple two‐terminal nanodevices to perform functions (such as image recognition and pattern classification) that had been earlier demonstrated in neural networks with continuous, deterministic synaptic weights. Moreover, CrossNets can also be trained to work as classifiers by the faster error‐backpropagation method, despite the absence of a layered structure typical for the usual neural networks. Finally, one more method, ‘global reinforcement’, may be suitable for training CrossNets to perform not only the pattern classification, but also more intellectual tasks. A demonstration of such training would open a way towards artificial cerebral‐cortex‐scale networks capable of advanced information processing (and possibly self‐development) at a speed several orders of magnitude higher than that of their biological prototypes. Copyright © 2004 John Wiley & Sons, Ltd.
Reconfigurable magnetoelectronic circuits for threshold logic
Authors: P. Carter Nicholas , Ferrera Steve P. 
Published: September 2004

AbstractMagnetoelectronic devices, which combine ferromagnetic materials with conventional silicon structures, offer the potential to add non‐volatile storage to electronic systems, eliminating their vulnerability to data loss due to power supply interruptions. We present a set of circuits, based on the Hybrid Hall Effect device, that combine logic with non‐volatile storage. These circuits can be configured on a cycle‐by‐cycle basis to compute different functions of their inputs, store their outputs indefinitely even in the absence of system power, and can be easily integrated into CMOS systems to provide non‐volatile operation without requiring additional supply voltages or other global signals. They exploit the properties of the Hybrid Hall Effect device to efficiently implement threshold logic functions and thereby reduce the number of gates required to implement most Boolean expressions.In this paper, we describe our reconfigurable magnetoelectronic circuits and the interfaces that make them compatible with CMOS systems. The results presented are based on data from fabricated experimental devices, and we discuss how they can be expected to improve as devices scale to nanometer dimensions. Finally, we consider how magnetoelectronic circuits might be integrated into system designs to deliver high performance while tolerating power supply interruptions. Copyright © 2004 John Wiley & Sons, Ltd.
Correlation and Interaction between Sidewall Passivation and Chamber Walls Deposition During Silicon Gate Etching
Authors: Kogelschatz M. , Cunge G. , Joubert O. , Vallier L. , Sadeghi N. 
Published: September 2004

AbstractThe aim of the present paper is to review our work on plasma‐surface interactions during the etching of silicon gates in low pressure high density HBr/Cl2/O2 based plasmas. In integrated circuit manufacturing, the transfer of patterns onto the polysilicon layer relies on the formation of a passivation layer on sidewalls of the etched features, which protects the silicon gate sidewall fromisotropic etching. At the same time, a layer with an almost identical chemical composition is also deposited on the reactor walls and can modify the process parameters by changing the radicals' surface loss probability. In this work we use a new “plasma etching‐sputtering” diagnostic technique, involving a subsequent “mild etching” of the layer deposited on the chamber walls by a few % SF6‐containing Ar plasma. Thus we investigate the chemical composition of this layer. This chemical composition is deduced from the time variation of the gas phase concentration of different atoms and radicals, the etch products of the wall deposited layer, monitored during the “mild etching” of the layer by time‐resolved optical emission spectroscopy and mass spectrometry.Optical absorption spectroscopy and mass spectrometry have been employed to characterize the HBr/Cl2/O2 plasma, currently used for the gate etching, and to estimate the absolute flux of neutral and ionic deposition precursors reaching the reactor walls. It comes out that the silicon wafer etch byproducts, SiClx radicals (x < 2) and SiOyCl+x ions, are the main depositing agents.Finally, the chemical topography analysis method, based on the X‐ray photoelectron spectroscopy, has been used to determine the chemical composition of the layer formed on the sidewalls of the silicon etched features. We show that the layers deposited on the sidewalls and on the chamber walls are both silicon oxyhalogenides (SiOyClx) compounds, formed by the subsequent oxidation of the deposited silicon chloride etching by‐products. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Combinatorial CVD of Zirconium, Hafnium, and Tin Oxide Mixtures for Applications as High‐κ Materials
Authors: Xia B. , Chen F. , Campbell S.A. , Roberts J.T. , Gladfelter W.L. 
Published: September 2004

AbstractA low‐pressure CVD reactor was modified to create continuous compositional spreads of ZrO2/HfO2/SnO2 on a single Si(100) wafer. Anhydrous metal nitrates were used as single‐source precursors to grow the films, and the compositions were mapped using Rutherford backscattering spectroscopy (RBS). An array of 100 × 100 μm2 capacitors was used to map the dielectric constant. High dielectric constants were observed for the films having high ZrO2 concentrations, while high SnO2 concentrations correlated with low values of κ.
Deficits in Dyslexia: Barking up the wrong tree?
Authors: Moores Elisabeth 
Published: September 2004

AbstractReviews of the dyslexia literature often seem to suggest that children with dyslexia perform at a lower level on almost any task. Richards et al. (Dyslexia 2002; 8: 1–8) note the importance of being able to demonstrate dissociations between tasks. However, increasingly elegant experiments, in which dissociations are found, almost inevitably find that the performance of children with dyslexia is lower as tasks become more difficult! By looking for deficits in dyslexia, could we be barking up the wrong tree? A methodological approach for circumventing this potential problem is discussed. Copyright © 2004 John Wiley & Sons, Ltd.
Complex Formation of ICL670 and Related Ligands with FeIII and FeII
Authors: Steinhauser Stefan , Heinz Uwe , Bartholomä Mark , Weyhermüller Thomas , Nick Hanspeter , Hegetschweiler Kaspar 
Published: September 2004

AbstractComplex formation of 4‐[3,5‐bis(2‐hydroxyphenyl)‐1,2,4‐triazol‐1‐yl]benzoic acid (ICL670, H3Lx), 4‐[3,5‐bis(2‐hydroxyphenyl)‐1,2,4‐triazol‐1‐yl]benzosulfonic acid (H3Ly), and 3,5‐bis(2‐hydroxyphenyl)‐1‐phenyl‐1,2,4‐triazole (H2Lz) with Fe3+ and Fe2+ was investigated in H2O and in H2O/DMSO mixtures by potentiometry, spectrophotometry and cyclic voltammetry. ICL670 has previously been considered as a promising drug for an oral treatment of iron overload. In this paper, the stability and redox properties of the various FeII and FeIII complexes were elucidated with a particular focus on their potential involvement in the generation of oxidative stress. The overall stability constants of [FeIII(Lx)] and [FeIII(Lx)2]3− (25 °C, 0.1 M KCl in H2O) are log β1 = 22.0 and log β2 = 36.9, respectively. The affinity of these ligands for Fe2+ is remarkably poor. In particular, the 1:2 complexes [FeII(Lx)2]4− and [FeII(Ly)2]4− were found to be less stable. As a consequence, the redox chemistry of the [FeIII(Lx)]/[FeII(Lx)]− and the [FeIII(Lx)2]3−/[FeII(Lx)2]4− couples differs significantly. [FeIII(Lx)2]3− is a very weak oxidizing agent (E1/2 is approximately −0.6 V versus NHE) and reduction of [FeIII(Lx)2]3− is not anticipated under physiological conditions. The reduction potential of the [FeIII(Lx)]/[FeII(Lx)]− couple is considerably less negative and was estimated to be +0.1 V (versus NHE). The possible roles of the various Fe complexes as catalysts for the Fenton reaction in biological media are discussed. The crystal structures of H3Lx, Na[Fe(Lz)2]·4EtOH, Na[Al(Lz)2]· 4EtOH, and [Cu(Lz)(pyridine)]2 were investigated by single‐crystal X‐ray diffraction, and the possible influence of the particular steric requirements of these ligands on the stability of the metal complexes has been analyzed. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
A Parahydrogen Study of Catalytic Hydrogenation by Diphosphane‐Substituted Triruthenium Clusters
Authors: Prestwich Tom G. , Blazina Damir , Duckett Simon B. , Dyson Paul J. 
Published: September 2004

AbstractThe diphosphane‐substituted clusters [Ru3(CO)10(dppe)] and [Ru3(CO)8(dppe)2] [dppe = 1,2‐bis(diphenylphosphanyl)ethane] are shown to catalytically hydrogenate diphenylacetylene. This process is highly solvent‐dependent with fragmentation dominating in low‐polarity solvents, which indicates that the dppe ligand does not stabilise the cluster under catalytic conditions. In solvents of higher polarity, the clusters are active hydrogenation catalysts of lower activity than their monodentate phosphane analogues [Ru3(CO)10(L)2] (L = PPh3, PMe2Ph, PMe3, PCy3). (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
A method for establishing the critical threshold for aeolian transport in the field
Authors: Stout John E. 
Published: September 2004

AbstractA basic feature of any wind‐eroding surface is its threshold – the wind speed at which sediment transport is initiated. A new method was developed and tested that allows for the rapid determination of threshold under natural wind conditions in the ﬁeld. A mathematical expression that relates saltation activity and relative wind strength was reformulated so that threshold may be calculated from measurements of saltation activity and the mean and standard deviation of wind speed. To test the new method and determine its usefulness, a ﬁeld experiment was performed within a region of low‐relief dunes on the Southern High Plains of West Texas. The experimental system consisted of a 2‐m meteorological tower and a piezoelectric saltation sensor. It was found that during periods of active aeolian activity, threshold values could be calculated every 5 minutes. This new method allows for routine monitoring of surface threshold conditions in the ﬁeld. Example threshold calculations are presented and they demonstrate that the method works well. Published in 2004 by John Wiley & Sons, Ltd.