bluuebunny/crossref_metadata_2025_split huggingface dataset:
Levels of Gli3 repressor correlate withBmp4expression and apoptosis during limb development
Authors: Bastida Maria Félix , Delgado M. Dolores , Wang Baolin , Fallon John F. , Fernandez‐Teran Marian , Ros Maria A. 
Published: June 2004

AbstractRemoval of the posterior wing bud leads to massive apoptosis of the remaining anterior wing bud mesoderm. We show here that this finding correlates with an increase in the level of the repressor form of the Gli3 protein, due to the absence of the Sonic hedgehog (Shh) protein signaling. Therefore, we used the anterior wing bud mesoderm as a model system to analyze the relationship between the repressor form of Gli3 and apoptosis in the developing limb. With increased Gli3R levels, we demonstrate a concomitant increase in Bmp4 expression and signaling in the anterior mesoderm deprived of Shh signaling. Several experimental approaches show that the apoptosis can be prevented by exogenous Noggin, indicating that Bmp signaling mediates it. The analysis ofBmp4expression in several mouse and chick mutations with defects in either expression or processing of Gli3 indicates a correlation between the level of the repressor form of Gli3 andBmp4expression in the distal mesoderm. Our analysis adds new insights into the way Shh differentially controls the processing of Gli3 and how, subsequently, BMP4 expression may mediate cell survival or cell death in the developing limb bud in a position‐dependent manner. Developmental Dynamics 231:148–160, 2004. © 2004 Wiley‐Liss, Inc.
Elucidation of the Solution Structures of Transition Metal Complex Ion Pairs by NOE NMR Experiments
Authors: Macchioni Alceo 
Published: June 2004

AbstractOur results from structural investigations of transition metal complex ion pairs in solution by homonuclear and heteronuclear 1D‐ and 2D‐NOE NMR spectroscopy are reviewed. Both model (A) and catalytically active (B) complexes have been taken into account; their general formulas are: trans‐[ML2(N,X)(Y)(Z)]+A− (A) {M = FeII, RuII and OsII, L = PMe3, Y = CO, Z = COMe, A− = BPh3R−, CF3SO3−, BF4−, PF6− and B[3,5‐(CF3)2C6H3]4−; M = IrIII, L = PR3, Y = Z = H and A− = BPh4−, CF3SO3−, BF4−, PF6−} and [M′(N,X)(R,olefin)]+A− (B) {M′ = Pt, R = Me, olefin = ethene, propene and CH2=CHCOOMe, A− = BF4−; M′ = Pd, (R,olefin) = η1,η2‐5‐methoxycyclooctenyl, A− = BPh4−, CF3SO3−, BF4−, PF6−, SbF6− and B[3,5‐(CF3)2C6H3]4−}, where N,X = bis(pyrazolyl)methane, bipyridine, α‐diimines, α‐diamines or α‐oxo imines. The detection of dipolar interionic interactions in 1H‐NOESY and 19F,1H‐HOESY NMR spectra allowed relative anion‐cation orientations to be determined, these being well defined in most cases, with one orientation predominating in solution. We often found that the anion approaches the complexes from the side of the N,X‐ligands, due to an accumulation of positive charge at the junction of the moieties containing the N‐ and X‐donor atoms. In square‐planar complexes B, the apparently favoured apical positions were often protected either by electronic factors [N,X = bis(2‐pyridyl)amine or bis(pyrazolyl)methane] or by a combination of electronic and steric factors (N,X = α‐diimines). For M′ complexes, bearing Ar−N=C(Me)−C(Me)=N−Ar ligands, the position of the counter‐anion is finely modulated by the steric hindrance of the ortho‐aryl substituents. The accessibility of the metal centre, which is directly associated with the catalytic performances of the complexes, was determined by using the counteranion as a probe. Finally, average interionic distances were estimated for model complexes A, bearing unsymmetrical BPh3R− counter‐anions, based on the quantification of interionic NOEs. (© Wiley‐VCH Verlag GmbH, 69451 Weinheim, Germany, 2003)
Rhodium Clusters Substituted by Cycloheptatrienyl Ligands: Synthesis and Solid‐State Structure of [Rh11(CO)14(μ3‐η2:η3:η2‐C7H7)3]
Authors: Della Pergola Roberto , Comensoli Emanuela , Garlaschelli Luigi , Manassero Mario , Sansoni Mirella , Strumolo Donatella 
Published: June 2004

AbstractThe cluster [Rh11(CO)14(C7H7)3] (1) was obtained from the reaction of [Rh6(CO)16] and an excess of cycloheptatriene in refluxing toluene. Initially, the substituted cluster [Rh6(CO)13(C7H8)] (2) could be identified spectroscopically, which is transformed into 1 after prolonged refluxing. In the solid state, the eleven rhodium atoms define a trioctahedral metal cage, condensed through a common edge. The three planar, equivalent C7 rings sit on the top of triangular faces. The spectroscopic characterisation of the product is hampered by its low solubility. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Synthesis and Characterization of a Carbene·SO2 Adduct − New Insights into the Structure and Bonding of Thiourea S,S‐Dioxides
Authors: Denk Michael K. , Hatano Ken , Lough Alan J. 
Published: June 2004

AbstractThe title compound 1,3‐di‐tert‐butylimidazol‐2‐ylidene·SO2 (2) was obtained from the respective stable carbene 1 and SO2 in quantitative yield and investigated by single crystal X‐ray crystallography and NMR spectroscopy. Quantum chemical calculations show that thiourea‐S,S‐dioxides like 2 are Lewis acid‐base adducts of the respective diamino carbenes with SO2 (CS bond energies < 20 kcal·mol−1). They possess long CS bonds and a pyramidal sulfur atom and are thus structurally distinct from sulfur ylides or sulfenes. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Use of Molecular Scaffolding for the Stabilization of an Intramolecular Dative PIII‐PV System
Authors: Kilian Petr , Philp Douglas , Slawin Alexandra M. Z. , Woollins J. Derek 
Published: June 2004

AbstractThe reaction of NapP2S4 (1; Nap = naphthalene‐1,8‐diyl) with chlorine gas gave [Nap(PCl2)(PCl4)] (2), displaying a rare σ4P‐σ6P bonding interaction. An X‐ray structure analysis confirmed the PCl5‐like, P−P bond containing phosphonium‐phosphoride structure of 2 in the crystal, which was also found in solution at low temperature. At ambient and higher temperatures, dynamic behaviour on the NMR time‐scale was observed, which was assigned to interchange of the ionic phosphonium‐phosphoride form 2 and the molecular bis(phosphorane) Nap(PCl3)2 form 3, rather than to the ionic phosphonium salt‐phosphorane form [Nap(PCl3)(PCl2)][Cl] 4. Electronic structure calculations were performed at the B3LYP/6−31G(d,p) level of theory on structures 2 and 3; structure 3 was located as a local minimum on the potential energy surface, 15 kcal·mol−1 higher in energy than structure 2. The crystal structure and calculated P−P distances are 2.34 and 2.31 Å for 2 and 3, respectively. An activation energy of 19.7 kcal·mol−1 was found for the transition state structure by coordinate driving calculations; the line‐shape analysis of variable temperature 31P{1H} NMR spectra gave an activation energy of 14.4 kcal·mol−1. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Facile Metal‐Mediated Synthesis of Macrocyclic Diselenoethers
Authors: Yeo Jeremy S. L. , Vittal Jagadese J. , Hor T. S. Andy 
Published: June 2004

AbstractNucleophilic attack of [Pt2(μ‐Se)2(PPh3)4] on dihaloalkanes gives stable diselenolato complexes, which release macrocyclic diselenoethers upon treatment with dihaloalkanes. The overhead‐bridged diplatinum intermediates have been isolated and structurally characterized by single‐crystal X‐ray crystallography. (© Wiley‐VCH Verlag GmbH, 69451 Weinheim, Germany, 2003)
A CuII Chain Compound Showing a Ferromagnetic Coupling through Triple N1,N2‐1,2,4‐Triazole Bridges
Authors: Garcia Yann , van Koningsbruggen Petra J. , Bravic Georges , Chasseau Daniel , Kahn Olivier 
Published: June 2004

Abstract[Cu(hyetrz)3](CF3SO3)2·H2O [hyetrz = 4‐(2′‐hydroxyethyl)‐1,2,4‐triazole] represents the first structurally characterised ferromagnetically coupled CuII chain compound containing triple N1,N2‐1,2,4‐triazole bridges. catena‐[μ‐Tris{4‐(2′‐hydroxyethyl)‐1,2,4‐triazole‐N1,N2}copper(II)] bis(trifluoromethanesulfonate) hydrate (C14H23F6S2O10CuN9) crystallises in the triclinic space group P$\bar 1$
, a = 13.54(3), b = 14.37(3), c = 15.61(4) Å, α = 95.9(1), β = 104.9(1), γ = 106.5(1)°, V = 2763(11) Å3, Z = 4 (CuII units). The CuII ions are linked by triple N1,N2‐1,2,4‐triazole bridges yielding an alternating chain with Cu1−Cu2 = 3.8842(4) Å and Cu2−Cu3 = 3.9354(4) Å. Analysis of the magnetic data according to a high‐temperature series expansion gives a J value of +1.45(3) cm−1. The nature and the magnitude of the ferromagnetic exchange have been discussed on the basis of the structural features. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Convenient Controllable Synthesis of Inorganic 1D Nanocrystals and 3D High‐Ordered Microtubes
Authors: Kang Zhenhui , Wang Enbo , Jiang Min , Lian Suoyuan , Li Yangguang , Hu Changwen 
Published: June 2004

AbstractPolyoxometalates (POMs) nanorods, hollow particles, microtubes, and 3D‐ordered tube systems were prepared using a novel and simple PEG/H2O liquid system. POM nanorods with various diameters (30−400 nm) and lengths (500 nm to 2 μm) were produced in a well‐controlled manner. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
A New Highly Active Diphosphane‐Palladium(II) Complex as a Catalyst Precursor for the Heck Reaction
Authors: Sjövall Sven , Johansson Maria H. , Andersson Carlaxel 
Published: June 2004

AbstractThe new diphosphane ligand cis‐1,3‐bis[(diphenylphosphanyl)methyl]cyclohexane (4) has been prepared and has allowed the synthesis of the palladium complex cis‐[Pd(4)(CO2CF3)2] (6). To obtain cis complexation of the diphosphane in 6 the cyclohexane skeleton adopts a chair conformation with a diaxial orientation of the substituents, a structure that has been verified by an X‐ray structure determination. This complex efficiently catalyses the vinylation of iodo‐ and bromobenzenes in high yields. For the best reaction, with methyl acrylate and iodobenzene, a yield of >98% was obtained with an average turnover frequency of 11 760 h−1 and a turnover number of 1 176 000.
2,6‐Di‐tert‐butyl‐4‐(3,3‐diarylpropadienylidene)‐2,5‐cyclohexadien‐1‐ones, the First Stable p‐Quinopropadienes
Authors: Kawase Takeshi , Nishigaki Naoki , Kurata Hiroyuki , Oda Masaji 
Published: June 2004

AbstractTreatment of 2,6‐di‐tert‐butyl‐4‐ethynylphenol with 2 equivalents of nBuLi, followed by addition of diaryl ketones, afforded the corresponding p‐quinopropadienes 2a−f upon appropriate dehydrative treatments. These compounds are fairly stable, orange to purple, crystalline substances, exhibiting intense absorptions at longer wavelengths. In particular, the bis(dimethylamino) derivative 2a absorbs across the whole of the visible spectrum and into the near infrared. Unlike the quinone methides 1, compounds 2 exhibited irreversible oxidation waves together with irreversible reduction waves on cyclic voltammetry. The very small E1sum value of 2a also indicates the highly amphoteric redox properties of 2a; however, both the anion and cation radicals of 2 are highly reactive. The molecular structures of 2a and 2e exhibit relatively small dihedral angles between two aromatic ring planes (2a for 47° and 2e for 52°), and each has a short central double bond and long side double bonds. The short central double bond (2a for 1.228 Å and 2e for 1.235 Å) indicates the importance of the resonance contribution of the dipolar structure with an acetylenic bond. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Two New Haliclamines from the Arctic Sponge Haliclona viscosa
Authors: Volk Christian A. , Lippert Heike , Lichte Ellen , Köck Matthias 
Published: June 2004

AbstractThere are a large number of studies on sponges from warm or tropical waters, whereas little is known about the chemistry of sponges from Arctic waters. Here, we describe the isolation and structure elucidation of two new 3‐alkyltetrahydropyridine alkaloids (haliclamines C and D) from the Arctic sponge Haliclona viscosa. MS and 2D NMR spectroscopy were used to analyse the structure of the two new compounds. Since the haliclamines consist of long alkyl chains, MS/MS methods were necessary for the unambiguous assignment of the constitution of the new alkaloids. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Synthesis of Concave 1,10‐Phenanthrolines by a Combination of Suzuki Coupling, Ring Closing Metathesis and Hydrogenation
Authors: Lüning Ulrich , Fahrenkrug Frank 
Published: June 2004

AbstractA wide variety of saturated and unsaturated concave 1,10‐phenanthrolines 2 and 4 have been synthesized in good yields starting from dichloro‐1,10‐phenanthroline 14. In the three step synthesis, Suzuki couplings of bis‐ortho‐substituted boronic acids were used to introduce two different or two identical aryl bridgeheads into the 2‐ and 9‐positions of the 1,10‐phenanthroline (yields ⩾70%). The resulting diaryl‐1,10‐phenanthrolines 3, substituted with alkenyloxy groups of different lengths, underwent ring closing metathesis reactions giving (bi)macrocyclic 1,10‐phenanthrolines 4 in yields between 73 and 96%. The alkene chains of 4 were saturated using hydrogen and Pd/C giving the concave 1,10‐phenanthrolines 2 in yields between 75 and 99%. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Hydrogen Evolution from Peroxides − a Concerted Reaction
Authors: Thiel Werner R. 
Published: June 2004

AbstractDFT calculations provide strong evidence that the evolution of hydrogen from mixtures of aldehydes and hydrogen peroxide proceeds by a concerted mechanism. The electronic influence of a series of substituents is correlated with the enthalpies of activation and reaction, and the calculated isotope effect of the reaction is compared with experimentally obtained data. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Charge‐Transfer Interactions in 4‐Donor 4′‐Acceptor Substituted 1,1‐Diphenylethenes
Authors: van Walree Cornelis A. , Kaats‐Richters Veronica E. M. , Veen Sandra J. , Wieczorek Birgit , van der Wiel Johanna H. , van der Wiel Bas C. 
Published: June 2004

AbstractTwo 1,1‐diphenylethenes bearing either a 4‐dimethylamino or 4‐methoxy group as electron donor and a 4′‐cyano group as electron acceptor, as well as compounds containing only a donor or acceptor functionality, were synthesized. The observation of strong fluorescence solvatochromism (originating from a biradicaloid twisted intramolecular charge‐transfer state) of the donor‐acceptor compounds reveals that photoinduced charge separation through the cross‐conjugated 1,1‐diphenylethene spacer occurs. The presence of weak charge‐transfer absorption bands in the UV spectra reflects modest ground state donor‐acceptor coupling. These results show that charge transport through a branched conjugation path is possible. 1‐[4‐(Dimethylamino)phenyl]‐1‐phenylethene was found to fluoresce from two different states. In nonpolar solvents the source is a local aniline‐like state, whereas in polar solvents the fluorescence originates from a twisted intramolecular charge‐transfer state. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Fuzzy State Controller for the Soft Process Drying of Natural Material Foil
Authors: Ewald T. , Delgado A. , Becker T. 
Published: June 2004

AbstractThis contribution describes the development of a fuzzy‐based process control system for the soft process drying of natural material foils. The system should maintain constant product moisture to facilitate automatic treatment of the foils in subsequent processing steps. A pilot plant was constructed to support the development of the control system. The core of the experimental setup is an optical measuring device, that provides for the simultaneous in‐line determination of drying foil water content and thickness at different places in the drying plant. The sensor possesses a measuring range of 10 %–80 % for water content (X*) and 50 μm–500 μm for thickness. Compared to a reference method, the system shows an accuracy of ± 3 % for the water concentration and 3.5 % for the foil thickness. No significant drift in the output signal could be detected for 5 weeks. These quantities, together with other process information, were used as inputs for a multistage fuzzy control system, which adjusts the outputs temperature and velocity of drying air and belt velocity for optimal soft process drying. In normal operation without the controller, foil moisture variations of 7 % over a period of 2 hours were obtained, while applying the fuzzy logic controller decreased the variations to 4 %. After disturbances of up to 17.5 % in initial viscosity, 6.8 % in concentration and 20 % in foil thickness variations, outlet moisture content variations of only 6.2 % were attained.
Hydrodynamics and Gas Dispersion Characterization in a System Equipped with a New Gas‐Inducing Impeller
Authors: Sardeing R. , Ferrand F. , Poux M. , Avrillier P. , Xuereb C. 
Published: June 2004

AbstractA new agitation system, called Turboxal, used for the oxygenation and the mixing of wastewater biological treatment tanks has been studied. The interactions between the shell and the three impellers which compose the Turboxal have been analyzed by single‐phase flow patterns. The pumping capacity and the power consumption have also been measured. In addition, the gas dispersion regimes have been analyzed in the tank and in the shell. Finally, the effect of the interaction and the effect of the position of the different agitators on the limit of the flooding regime have been determined.
A Screening Analysis of the High‐Pressure Extraction of Anthocyanins from Red Grape Pomace with Carbon Dioxide and Cosolvent
Authors: Mantell C. , Rodríguez M. , Martínez de la Ossa E. 
Published: June 2004

AbstractIn the work described here, a set of screening factorial design experiments was carried out in order to study the extraction process of anthocyanins from red grape pomace with carbon dioxide, along with either methanol or water as cosolvent, at high pressure. The variables studied were pressure, temperature, solvent flow‐rate, cosolvent percentage, cosolvent type (methanol or water) and extraction time. The quantification of the total amount of anthocyanins was performed by a colorimetric method. The results of the ANOVA study show a strong influence of the type and percentage of cosolvent. The best results were obtained with 20 mol‐% of methanol, 100 bar, 60 °C and a flow‐rate of 22 mmol/min after two hours of extraction.
Improved design of sliding mode control for civil structures with saturation problem
Authors: Lee Sang‐Hyun , Min Kyung‐Won , Lee Young‐Cheol , Chung Lan 
Published: June 2004

AbstractA systematic and improved design procedure for sliding mode control (SMC) of seismically excited civil structures with saturation problem is provided in this paper. In order to restrict the control force to a certain level, a procedure for determining the upper limits of the control forces for single or multiple control units is proposed based on the design response spectrum of external loads. Further, an efficient procedure using the LQR method for determining sliding surfaces appropriate for different controller types is provided through the parametric evaluation of the dynamic characteristics of sliding surfaces in terms of SMC controller performance. Finally, a systematic design procedure for SMC required to achieve a given performance level is provided and its effectiveness is verified by applying it to multi‐degree‐of‐freedom (MDOF) systems. Copyright © 2004 John Wiley & Sons, Ltd.
Culturally competent evaluation in Indian Country
Authors: LaFrance Joan 
Published: June 2004

AbstractCulturally competent evaluation in Indian Country requires an understanding of the rich diversity of tribal peoples and the importance of self‐determination and sovereignty. If an evaluation can be embedded within an indigenous framework, it is more responsive to tribal ethics and values. An indigenous orientation to evaluation suggests methodological approaches, a partnership between the evaluator and the program, and reciprocity.
Lessons for culturally competent evaluation from the study of a multicultural initiative
Authors: King Jean A. , Nielsen Julie E. , Colby Jeanette 
Published: June 2004

AbstractBringing together individuals from cultural backgrounds with varied values and norms for expressing conflicting ideals can elevate the tensions inherent in participatory evaluation. As the authors of this chapter found out, even the most deliberate attention to cultural issues does not guarantee a smooth ride.
A high‐resolution scheme for low Mach number flows
Authors: Chakravorty Saugata , Mathew Joseph 
Published: June 2004

AbstractA method for computing low Mach number flows using high‐resolution interpolation and difference formulas, within the framework of the Marker and Cell (MAC) scheme, is presented. This increases the range of wavenumbers that are properly resolved on a given grid so that a sufficiently accurate solution can be obtained without extensive grid refinement. Results using this scheme are presented for three problems. The first is the two‐dimensional Taylor–Green flow which has a closed form solution. The second is the evolution of perturbations to constant‐density, plane channel flow for which linear stability solutions are known. The third is the oscillatory instability of a variable density plane jet. In this case, unless the sharp density gradients are resolved, the calculations would breakdown. Under‐resolved calculations gave solutions containing vortices which grew in place rather than being convected out. With the present scheme, regular oscillations of this instability were obtained and vortices were convected out regularly. Stable computations were possible over a wider range of sensitive parameters such as density ratio and co‐flow velocity ratio. Copyright © 2004 John Wiley Sons, Ltd.
Psychosocial correlates of late‐onset psychosis: life experiences, cognitive schemas, and attitudes to ageing
Authors: Giblin Sharon , Clare Linda , Livingston Gill , Howard Rob 
Published: June 2004

AbstractBackgroundPsychosis with first onset after the age of 60, and arising in the absence of dementia or primary affective disorder, is thought to affect 2–4% of older people, and as many as half will not respond fully to medication.AimsThis study represents a preliminary attempt to explore a number of possible psychosocial correlates of late‐onset psychosis with potential relevance for a cognitive‐behavioural formulation and for the development of psychosocial interventions for this group.MethodsThe nature and extent of adverse early life experiences, presence of maladaptive cognitive schemas, and morale in relation to ageing were compared for older people with a diagnosis of late‐onset psychosis (LOP; n = 14) or late‐onset depression (DEP; n = 13) and healthy older volunteers (HEV; n = 18) in a cross‐sectional design.ResultsBoth LOP and DEP groups reported significantly higher levels of adverse life experiences than the HEV group, with between‐group differences in the types of experiences described. The LOP group scored significantly higher than the HEV group on four out of five schema domains, and significantly higher than the DEP group on two domains, other‐directedness and over‐vigilance/inhibition. The LOP group had significantly lower overall morale in relation to ageing than the HEV group, reflecting significantly higher levels of lonely‐dissatisfaction.ConclusionsLife experiences, cognitive schemas and attitudes to ageing are important psychosocial correlates of LOP. These findings contribute to an understanding of the emotional world of individuals who develop psychosis in later life and may have implications for developing more effective intervention approaches. Copyright © 2004 John Wiley & Sons, Ltd.