bluuebunny/crossref_metadata_2025_split huggingface dataset:
Design of a high‐sensitivity negative ion source time‐of‐flight mass analyzer assembly created by cylindrical electrodes with a common axis
Authors: Ioanoviciu D. , Cuna C. , Cosma V. , Albert I. , Szilagyi Edina 
Published: December 2004

AbstractThe new design incorporates the negative ion source and the mass analyzer, both constructed from cylindrical electrodes. The ion source is formed by three gridded cylindrical electrodes: a pulsed grid, the intermediate grid and the final accelerating grid. During a first time lapse, the electrons penetrate through the pulsed grid into the retarding field between this grid and the intermediate grid. The electrons are turning at some depth inside this intergrid space, where the attachment to neutral molecules most probably occurs. Next, the pulsed grid becoming strongly negative and ions are extracted towards the final acceleration grid. The ions from the cylindrical surface where they were created concentrate on the common axis of the electrodes (lateral focusing). The source lateral and time focus are coincident. A cylindrical electrostatic mirror is fitted to the source. The design, with a single stage, ensures also lateral focusing of the ions diverging from the common axis of the electrodes. The mirror electric and geometric parameters were selected to ensure both lateral and time focusing on the final detector with subsequent high luminosity. The basic parameters of the specific negative ion source time‐of‐flight mass analyzer design proposed here, are ion source final acceleration, intermediate, pulsed cylindrical grid radii 10, 20 and 30 mm, respectively, electrostatic mirror earthed grid and ion turning points surface radii 0.6 and 0.8 m, respectively. Ion packet smearing by the ion energy spread (resulting from the initial electron energy spread as electrons are turning at different depths inside the ionization region, from the moment when ions were created, being accelerated towards the pulsed grid during ionization) and by the turnaround time inside the cylindrical field was accounted for. Maintaining very high sensitivity, a resolution of the order of 100 is expected. Copyright © 2004 John Wiley & Sons, Ltd.
Tandem mass spectrometry of intact oxidation products of diacylphosphatidylcholines: evidence for the occurrence of the oxidation of the phosphocholine head and differentiation of isomers
Authors: Reis A. , Domingues P. , Ferrer‐Correia A. J. V. , Domingues M. R. M. 
Published: December 2004

AbstractThree glycerophosphatidylcholine (GPC) phospholipids (oleoyl‐, linoleoyl‐ and arachidonoylpalmitoylphosphatidylcholine) were oxidized under Fenton reaction conditions (H2O2 and Fe2+), and the long‐chain oxidation products were detected by electrospray mass spectrometry (ES‐MS) and characterized by ES‐MS/MS. The intact oxidation products resulted from the insertion of oxygen atoms into the phospholipid structure. The tandem mass spectra of the [MNa]+ molecular ion showed, apart from the characteristic fragments of GPC, fragment ions resulting from neutral losses from [MNa]+, and combined with loss of 59 and 183 Da from [MNa]+. These ions resulted from cleavage of the bond near the hydroxy group by a charge‐remote fragmentation mechanism, allowing its location to be pinpointed. The fragments thus formed reflected the positions of the double bonds and of the derivatives along the unsaturated fatty acid chain, giving very useful information, as they allowed the presence of structural isomers and positional isomers to be established. The identification of the fragment ion at m/z 163, which is 16 Da higher than the five‐membered cyclophosphane ion (m/z 147), in some tandem mass spectra, is consistent with the oxidation of the phosphocholine head. Some ions were found to occur with the same m/z value; in two of the phospholipids and based on the MS/MS data, structural and positional isomers were differentiated. Our findings indicate that MS/MS is a valuable tool for the identification of the wide complexity of structural features occurring in oxidized phosphatidylcholines during lipid peroxidation in cellular membranes. Copyright © 2004 John Wiley & Sons, Ltd.
Electrospray ionization ion‐trap multistage mass spectrometric study of sodium cationized aldobiuronic and pseudoaldobiuronic acid derivatives
Authors: Kováčik Vladimír , Bekešová Slávka , Tvaroška Igor , Hirsch Ján , Chmelík Josef 
Published: December 2004

AbstractFragmentation mechanisms of electrospray ionization (ESI) mass spectrometry of aldobiuronic and pseudoaldobiuronic acid derivatives were elucidated by multistage mass spectrometric (MSn, n = 2–5) measurements of selected ions. Characteristic under the conditions of ESI‐MS analysis is the production of alkali metal (Na and K) cationized adducts. The probability the of locations of Na cations in per‐O‐methylated compounds was proved by quantum chemical calculations, using the Jaguar program. The most probably position of alkali metal attachment is the carboxy group of the methoxycarbonyl C‐5 group of the uronic acid unit. Characteristic cleavages vary according the kind of O‐derivatization. In most cases they take place on the acidic part of the dimer and at the interglycosidic oxygen atom. As a result, the criteria for the differentiation of aldobiouronic and pseudoaldobiouronic acids derivatives were elucidated. Copyright © 2004 John Wiley & Sons, Ltd.
Twentieth century droughts and wet periods in Auckland (New Zealand) and their relationship to ENSO
Authors: Fowler A. , Adams K. 
Published: December 2004

AbstractIn early 1994 the city of Auckland (New Zealand) was in the midst of a major water supply crisis. El Niño was blamed, and it is now a widely held view that Auckland's droughts and wet periods are predominantly a consequence of the El Niño–southern oscillation (ENSO) phenomenon. The scientific literature is consistent with a significant influence of ENSO on New Zealand's climate, but is less convincing that it is the dominant forcing factor for Auckland's droughts and wet periods. To investigate this, we constructed a seasonal history of 20th century droughts and wet periods and compared it with a seasonal time series of ENSO activity based on the southern oscillation index. Our drought/wetness index was derived from daily modelling of soil water content and used the climatological potential evaporation method advocated by Fowler (2002. Journal of Hydrology 256: 248–263) for century‐scale soil water modelling. In deriving this index we identified a seasonal bias issue associated with soil‐water‐based methods and developed a simple index calculation method to circumvent the problem.Comparison of the ENSO and drought/wetness indices does not support the contention that droughts and wet periods in Auckland are primarily associated with ENSO. Relationships are weak and inconsistent (especially between La Niñas and wet periods), and decadal‐scale variation in ENSO activity is not coupled with changes in the frequency and magnitude of droughts and wet periods. Many droughts and wet periods do not coincide with ENSO events, and many ENSO events have little impact. These findings were confirmed by a mean sea‐level pressure compositing analysis. This linked droughts and wet periods with synoptic‐scale atmospheric circulation patterns that show no significant relationship to the pressure anomaly patterns associated with ENSO events. We conclude that ENSO has been overrated as a cause of Auckland's droughts and wet periods, and that it would be appropriate to focus more attention on identifying and investigating other plausible forcing factors. Copyright © 2004 Royal Meteorological Society
Managing the concept of strategic change within a higher education institution: the role of strategic and scenario planning techniques
Authors: Richards Leanne , O'Shea John , Connolly Michael 
Published: December 2004

Abstract

Many higher education institutions in the UK develop strategies based on traditional strategic planning techniques and environmental scanning methods. The case study of the University of Glamorgan presented here illustrates and supports the notion that the reliance on these traditional techniques may not be enough to enable higher education institutions to plan strategically and also balance the pressures of change within the current higher education environment.
The case study focuses on the introduction and use of scenario planning as an additional strategic planning and environmental scanning tool. The outcomes demonstrate that the tool is useful as a means of enabling institutions to evaluate the external environment against their core mission and strengths to ensure that they respond only to those external changes that will either enhance business or represent a significant threat to it.
Specifically the study also illustrates the effectiveness of scenario planning in involving all staff across the organization and encouraging their imaginations and ideas about future strategies and priorities for that organization.

Copyright © 2004 John Wiley & Sons, Ltd.
SME marketing networking: a strategic approach
Authors: Carson David , Gilmore Audrey , Rocks Steve 
Published: December 2004

Abstract

A strategic approach to how small and medium sized enterprises (SMEs) use their marketing networks during a time of change in their operating context is the focus of this article. SME networking is analysed using the structural, relational and usage dimensions associated with network frameworks.
Specifically, the paper examines marketing network processes (MNPs) that are investigated through the use of network behaviour for SME management. The development of a thematic approach in viewing a network as a strategic analytical construct allowed these MNPs to be studied in relation to the specific theme chosen and how they do their strategic marketing.
The research in this paper focused on the use of SME network activities in relation to strategic marketing, to gain an in‐depth understanding of the nature and role of strategic marketing networks in SMEs during a time of environmental change.

Copyright © 2004 John Wiley & Sons, Ltd.
Harmaline‐induced tremor as a potential preclinical screening method for essential tremor medications
Authors: Martin Fredricka C. , Thu Le Anh , Handforth Adrian 
Published: December 2004

AbstractNo preclinical method to evaluate potential new medications for essential tremor (ET) is available currently. Although harmaline tremor is a well known animal model of ET, it has not found utility as a preclinical drug screen and has not been validated with anti‐ET medications. We measured harmaline tremor in rats (10 mg/kg s.c.) and mice (20 mg/kg s.c.) with a load sensor under the cage floor and performed spectral analysis on 20‐minute epochs. The motion power over the tremor frequency bandwidth (8–12 Hz in rats; 10–16 Hz in mice) was divided by the motion power over the full motion frequency range (0–15 Hz in rats; 0–34 Hz in mice). The use of these measures greatly reduced data variability, permitting experiments with small sample sizes. Three drugs that suppress ET (propranolol, ethanol, and octanol) all significantly suppressed harmaline‐induced tremor. We propose that, with this methodology, harmaline‐induced tremor may be useful as a preclinical method to identify potential medications for ET. © 2004 Movement Disorder Society
Bilateral subthalamic nucleus deep brain stimulation in a patient with cervical dystonia and essential tremor
Authors: Chou Kelvin L. , Hurtig Howard I. , Jaggi Jurg L. , Baltuch Gordon H. 
Published: December 2004

AbstractThe role of subthalamic nucleus (STN) deep brain stimulation (DBS) is well established in Parkinson's disease, but experience with STN DBS in other movement disorders is limited. We report on a patient with medically refractory cervical dystonia and essential tremor resulting in dystonic head tremor and action tremor of the hands who obtained complete tremor suppression and near resolution of her cervical dystonia with bilateral STN stimulation. The results in this case demonstrate that STN DBS can dramatically improve dystonia and tremor in nonparkinsonian movement disorders. © 2004 Movement Disorder Society
Praying‐induced oromandibular dystonia
Authors: Ilic Tihomir V. , Pötter Monika , Holler Iris , Deuschl Günther , Volkmann Jens 
Published: December 2004

AbstractWe report on an unusual presentation of a task‐specific focal oromandibular dystonia in a 47‐year‐old man of Turkish descent. His speech was affected exclusively while reciting Islamic prayers in Arabic language, which he otherwise did not speak. © 2004 Movement Disorder Society
Synthesis of polypropylene graft copolymers by the combination of a polypropylene copolymer containing pendant vinylbenzene groups and atom transfer radical polymerization
Authors: Cao Chengang , Zou Junfeng , Dong Jin‐Yong , Hu Youliang , Chung T. C. 
Published: December 2004

AbstractThis article discusses a facile and inexpensive reaction process for preparing polypropylene‐based graft copolymers containing an isotactic polypropylene (i‐PP) main chain and several functional polymer side chains. The chemistry involves an i‐PP polymer precursor containing several pendant vinylbenzene groups, which is prepared through the Ziegler–Natta copolymerization of propylene and 1,4‐divinylbenzene mediated by an isospecific MgCl2‐supported TiCl4 catalyst. The selective monoenchainment of 1,4‐divinylbenzene comonomers results in pendant vinylbenzene groups quantitatively transformed into benzyl halides by hydrochlorination. In the presence of CuCl/pentamethyldiethylenetriamine, the in situ formed, multifunctional, polymeric atom transfer radical polymerization initiators carry out graft‐from polymerization through controlled radical polymerization. Some i‐PP‐based graft copolymers, including poly(propylene‐g‐methyl methacrylate) and poly(propylene‐g‐styrene), have been prepared with controlled compositions. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 429–437, 2005
Olefin metathesis applied to cellulose derivatives—Synthesis, analysis, and properties of new crosslinked cellulose plastic films
Authors: Joly Nicolas , Granet Robert , Krausz Pierre 
Published: December 2004

AbstractNew crosslinked cellulose‐based plastic films were synthesized with olefin metathesis as a crosslinking reaction. Microcrystalline cellulose was first dissolved in a lithium chloride/N,N‐dimethylacetamide solvent system and acylated by ω‐undecenoyl chloride under microwave irradiation with N,N‐dimethyl‐4‐aminopyridine as the catalyst. Cellulose unsaturated fatty acyl esters with a degree of substitution (DS) ranging from 1.4 to 2.0 were then crosslinked by olefin metathesis with a first generation Grubbs catalyst. Crosslinking ratios (T) ranging from 20 to 90% were obtained for low catalyst amounts (<1.2%), but gels appeared when T was too high. To avoid this gel formation, cellulose was acylated with a mixture of lauroyl and ω‐undecenoyl chlorides. This internal dilution allowed us to obtain films of every case and various T (varying from 10 to 80% for a catalyst amount below 3.5%). Plastics were characterized by Fourier transform infrared (FTIR) spectroscopy, and the fatty acid mixture resulting from the hydrolysis of cellulose esters were analyzed by gas chromatography (GC) and NMR spectroscopy. Mechanical properties showed that the elastic modulus and tensile failure stress was higher when the plastic films were crosslinked. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 407–418, 2005
Rigidity percolation model of polymer fracture
Authors: Wool Richard P. 
Published: December 2004

AbstractA theory of the fracture of polymers with network microstructure was developed that was based on the vector, or rigidity percolation (RP) model of Kantor and Webman, in which the modulus, E, is related to the lattice bond fraction p, via E ∼ [p − pc]τ. The Hamiltonian for the lattice was replaced by the strain energy density function of the bulk polymer, U = σ2/2E, where σ is the applied stress and p was expressed in terms of the lattice perfection via the bond density ν, with the entanglement molecular weight, ν = ρ/Me and appropriate measures of crosslink density for rubber, thermosets, and carbon nanotubes. The stored mechanical energy, U, was released by the random fracture of νDo[p − pc] over stressed hot bonds of energy Do ≈ 330 kJ/mol. The polymer fractured critically when p approached the percolation threshold pc, and the net solution was obtained as σ = (2EνDo [p − pc])1/2 with a fracture energy, G1c ∼ [p − pc]. The fracture strength of amorphous and semicrystalline polymers in the bulk was well described by, σ = [EDoρ/16 Me]1/2, or σ ≈ 4.6 GPa/Me1/2. Fracture by disentanglement was found to occur in a finite molecular weight range, Mc < M < M*, where M*/Mc ≈ 8, such that the critical draw ratio, λc = (M/Mc)1/2, gave the molecular weight dependence of the fracture as G1c ∼ [(M/Mc)1/2 − 1]2. The critical entanglement molecular weight, Mc, is related to the percolation threshold, pc, via Mc = Me/(1 − pc). Fracture by bond rupture was in accord with Flory's suggestion, G/G* = [1 − Mc/M], where G* is the maximum fracture energy. Fracture of an ideal rubber with p = 1 was determined not to occur without strain hardening at λ > 4, such that the maximum stress, σ = E (λ − 1/λ) = 3.75E. The fracture properties of rubber were found to behave as σ ∼ ν, σ ∼ E, and G1c ∼ ν. For highly crosslinked thermosets, it was predicted that σ ∼ (Eν)1/2, σ ∼ (X − Xc)1/2, and G1c ∼ ν−1/2, where X is the degree of reaction of the crosslinking groups and Xc defines the gelation point. When applied to carbon nanotubes (SWNT and MWNT) of diameter d and hexagonal bond density ν = j/b2, the nominal stress as a function of diameter is σ(d) = [16 EDo(p − pc) j/b]1/2/d ≈ 211/d (GPa.nm) and the critical force, Fc(d) ≈ 166 d (nN/nm), in which j = 1.15, b = 0.142 nm, E ≈ 1 Tpa, and Do = 518 kJ/mol. For polymer interfaces with Σ chains per unit area of length L and width X ∼ L1/2, G1c is then ∼ [p − pc], where p ∼ ΣL/X. The results predicted by the RP fracture model were in good agreement with a considerable body of fracture data for linear polymers, rubbers, thermosets, and carbon nanotubes. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 168–183, 2005
Syntheses and Crystal Structures of Two Metal Succinates Modified by Bipyridines
Authors: Zhang Jian , Li Zhao‐Ji , Wen Yi‐Hang , Kang Yao , Cheng Jian‐Kai , Yao Yuan‐Gen 
Published: December 2004

AbstractTwo new metal succinates modified by rigid bipyridines, Cd(4, 4′‐bpy)(C4H4O4)·1/4H2O (1) and Cu(2, 2′‐bpy)(C4H4O4)0.5(NO3)(H2O) (2) (bpy = bipyridine), have been synthesized by hydrothermal reactions and structurally determined. Complex 1 crystallizes in the orthorhombic space group Cmca with the cell parameters a = 11.696(2), b = 15.554(2), c = 15.874(3) Å, α = β = γ = 90.00°, V = 2888(3) Å3, Z = 8. Complex 2 crystallizes in the triclinic space group $P{\bar 1}$ with a = 7.077(1), b = 9.838(2), c = 10.461(2) Å, α = 71.941(3)°, β = 73.078(3)°, γ = 74.502(3)°, V = 649.8(2) Å3, Z = 2. In complex 1, a 2‐D network was formed by Cd‐succinato bonding. The 2‐D networks are pillared by 4, 4′‐bpy ligands, forming a 3‐D grid framework. The 2‐fold interpenetration of the resulting 3‐D frameworks completes the molecular structure. In complex 2, the CuII atom adopts a distorted octahedral in which the CuII atoms are bridged by two H2O molecules into an infinite zigzag chain, [Cu2(H2O)2(C4H4O4)]n. The neighboring chains are further linked by π‐π stacking interactions into a 2‐D network, and the interlayer hydrogen bonds lead to the final 3‐D crystal structure.
Bis(dimethylamino)trifluoromethylsulfonium Salze: [CF3S(NMe2)2]+[Me3SiF2]‐, [CF3S(NMe2)2]+[HF2]‐ und [CF3S(NMe2)2]+[CF3S]‐
Authors: Lork Enno , Viets Detlef , Müller Marco , Mews Rüdiger 
Published: December 2004

AbstractAus der Umsetzung von CF3SF3 mit überschüssigem Me2N‐SiMe3 wurden [CF3S(NMe)2]+ [Me3SiF2]‐ (CF3‐BAS‐fluorid) (5), aus CF3SF3/CF3SSCF3 und Me2NSiMe3 [CF3S(NMe2)2]+[SCF3]‐ (7) isoliert. Die thermische Zersetzung von 5 liefert [CF3S(NMe2)2]+[HF2]‐ (6). Reaktionswege werden diskutiert, die Strukturen von 5 ‐ 7 berichtet.
Zwitterionic Melaminium Trichloromercurate(II), [MelH+HgCl3‐](Mel)
Authors: Nockemann Peter , Meyer Gerd 
Published: December 2004

AbstractColourless long and thin needles of the reaction product of melamine with mercuric chloride in water/methanol, [MelH+HgCl3‐](Mel), crystallize with a structure that contains zwitterionic molecules [MelH+HgCl3‐] and “free” melamine (Mel) molecules; monoclinic, P21, Z = 2, a = 939.43(18), b = 682.80(9), c = 1218.9(2) pm, β = 99.61(2)°, R(all) = 0.0291, T = 20 °C.
A Correlation between Number of Electrons and Structures Chalcogen‐Nitrogen Compounds
Authors: Haas Alois 
Published: December 2004

AbstractA cage rule for S‐N compounds has been elucidated, Σπ = 4n + 4 (n = 0, 1, 2, 3) or Σπ = 4 n* (n* = 1, 2, 3), and its validity tested using SN compounds with known structures. It has also been applied to the structures of some recently prepared Se and Te nitrogen compounds. Predictions have been made for the synthesized compounds as well as the postulated intermediates. The results prove, that the cage rule is a meaningful supplement to Hückel's rule in chalcogen‐nitrogen chemistry.
Nickel(II)‐Komplexe von Oxalamidinen und Oxalamidinaten mit zusätzlichen R2P‐Donorgruppen
Authors: Stollenz Michael , Walther Dirk , Böttcher Lars , Görls Helmar 
Published: December 2004

AbstractOxalamidine R1N=C(HNR2)‐C(=NR2)‐NHR1, die in zwei der vier N‐Substituenten zusätzliche Donoratome besitzen (H2A: R1 = Mesityl, R2 = ‐(CH2)3‐PPh2; H2B: R1 = Tolyl, R2 = ‐(CH2)3‐PMe2), bilden mit Nickel(II)‐Ionen binucleare Komplexe, in denen ganz unterschiedliche Koordinationsformen realisiert werden. Im Komplex [(A)Ni2Br2] (1) sind die beiden Nickelatome auf jeder Seite der Brücke in planar‐quadratischer Umgebung, koordiniert an den beiden N‐Donoratomen des Oxalamidinatgerüsts, sowie an ein Bromid und eine Ph2P‐Gruppe. Eine analoge Koordination besitzt die Organometallverbindung [(A)Ni2Me2] (2). Im Gegensatz dazu ist die koordinative Umgebung der beiden Nickelatome in der Verbindung {[(B)][Ni(acac)]2} (5) unterschiedlich. Auf einer Seite des Oxalamidinatbrückenliganden koordiniert ein (acac)Ni‐Fragment an den beiden N‐Donoratomen unter Ausbildung einer planar‐quadratischen Konfiguration. Auf der gegenüberliegenden Seite ist das (acac)Ni‐Fragment sowohl an die beiden N‐Atome des Brückenliganden als auch an die beiden PMe2‐Gruppen der Seitenketten koordiniert, so dass sich eine oktaedrische Koordination für dieses Nickelatom ergibt.
Rhenium(I) and Technetium(I) Tricarbonyl Complexes with Phosphoraneimines
Authors: Hagenbach A. , Athenstädt S. , Daróczi H. E. , Abram Ulrich , Alberto R. 
Published: December 2004

Abstract[NEt4]2[Re(CO)3Br3] and [NEt4]2[Tc(CO)3Cl3] react with trimethylsilyltriphenylphosphoraneimine, Me3SiNPPh3, under exchange of the bromo ligands and the formation of cationic [M(CO)3(HNPPh3)3]+ complexes (M = Re, Tc). The required protons are abstracted from the solvent CH2Cl2. The steric bulk of the organic ligands causes a marked distortion of the established coordination polyhedra from an idealized octahedron with bond angles between neighbouring donor atoms between 81.81(8)° and 96.66(8)°.The reaction of [NEt4]2[Re(CO)3Br3] with Me3SiNP(Ph2)CH2PPh2 in CH2Cl2 yields the neutral complex [Re(CO)3Br{HNP(Ph2)CH2PPh2)], which contains a neutral, chelate‐bonded (diphenylphosphinomethyl)diphenylphosphoraneimine ligand. A similar reaction with the bifunctional phosphoraneimine Me3SiNP(Ph2)CH2(Ph2)PNSiMe3 gives only small amounts of a binuclear rhenium(I) complex of the composition [{Re(CO)3Br2}2(HNP(Ph2)CH2(Ph2)PNH)]2‐, whereas the major amount of the bis‐phosphoraneimine undergoes an intramolecular rearrangement to yield [H2NP(Ph2)NP(Ph2)CH3]Br. An X‐ray structure analysis shows a widespread delocalization of electron density over the central part of the cation.