bluuebunny/crossref_metadata_2025 huggingface dataset:
Protein kinase A regulates cell cycle progression of mouse fertilized eggs by means of MPF
Authors: Yu Bingzhi , Wang Yajie , Liu Ying , Liu Yi , Li Xinna , Wu Didi , Zong Zhihong , Zhang Jie , Yu Dahai
Published: December 2004

Cell cycle of one‐cell stage mouse fertilized eggs was accompanied by fluctuation in the concentration of adenosine 3′5′‐monophosphate (cAMP) and in the activity of free catalytic subunit of cAMP‐dependent protein kinase (PKA). The concentration of cAMP and the activity of free catalytic subunit of PKA decreased at the onset of mitosis and increased at the transition between mitosis and G1 phase. Stimulation of PKA by microinjection of cAMP into one‐cell stage mouse embryos at G2 phase induced interphase arrest and prevented the activation of M‐phase promoting factor (MPF). Upon blockage of the activation of PKA by microinjecting a thermostable PKA inhibitor (PKI) into one‐cell stage mouse embryos at G2 phase, the increase in the MPF activity occurred 30 min earlier than in control group. When a high dose of PKI was microinjected, a transition into interphase was prevented, and the activity of MPF remained high. Western blot analysis showed that Cdc2 remained phosphorylated in cAMP microinjected embryos by the time when control embryos were at metaphase and showed dephosphorylated Cdc2; conversely, Cdc2 dephosphorylation was accelerated in PKI‐microinjected embryos. At the same time, Cdc2 was phosphorylated at Tyr15 at G2 phase and even at M phase when cAMP was microinjected but was dephosphorylated when PKI was microinjected. PKI microinjection also prevented cyclin B degradation and sustained MPF activity, thus delaying the transition from metaphase to anaphase. Our results show that PKA, by inhibiting MPF, regulates cell cycle progression of fertilized eggs. Developmental Dynamics 232:98–105, 2005. © 2004 Wiley‐Liss, Inc.
Effects of genetic background on cardiovascular anomalies in the Ts16 mouse
Authors: Villar A.J. , Kim J. , De Blank P. , Gillespie A.M. , Kozy H.M. , Ursell P.C. , Epstein C.J.
Published: December 2004

To investigate the genetic contribution to phenotypic variability in aneuploidy, we generated mice with trisomy 16 (Ts16) by mating [Rb(6.16)24Lub × Rb(16.17)7Bnr]F1 males with females from four inbred strains, BALB/cJ, C3H/HeJ, C57BL/6J, and DBA/2J. Among the four Ts16 strains that were generated, there were no significant differences in survival, weight, or length relative to euploid control littermates at either embryonic day (E) 14.5 or E17.5. All Ts16 fetuses at E14.5 had edema that ranged from mild to severe, increased amniotic fluid volume, and a thickened neck. At E17.5, Ts16 fetuses exhibited two distinct phenotypes, one with an edematous morphology and the other runt‐like. None of these gross morphological abnormalities was strain‐specific either in occurrence or frequency. At E10.5, there were pharyngeal arch artery (PAA) anomalies in all Ts16 embryos on the C3H/HeJ background, but none in trisomics on the other three backgrounds. However, at E17.5, there was in addition to ventricular and atrioventricular septal defects, a high frequency of aortic arch defects in Ts16 fetuses, irrespective of genetic background. Taken together, these findings indicate that there are at least two mechanistic responses to the presence of three copies of mouse chromosome 16 in the modeling of the cardiovascular system: one, development of PAA defects, is strongly influenced by genetic background; but the second, development of aortic arch anomalies in the absence of preexisting PAA anomalies, is not. Developmental Dynamics 232:131–139, 2005. © 2004 Wiley‐Liss, Inc.
Critical roles of CD146 in zebrafish vascular development
Authors: Chan Barden , Sinha Sonia , Cho Dan , Ramchandran Ramani , Sukhatme Vikas P.
Published: December 2004

In this report, we use zebrafish as a model system to understand the importance of CD146 in vascular development. Endothelial‐specific expression of CD146 was verified by whole‐mount in situ hybridization. Suppression of CD146 protein expression by antisense morpholino oligonucleotides (MO) resulted in poorly developed intersomitic vessels (ISVs). In CD146 morphants, we observed a lack of blood flow through the ISV region, despite that fluorescence microangiography showed that the ISVs were present. This finding suggests that the lumens of the developing ISVs may be too narrow for proper circulation. Additionally, remodeling of the caudal vein plexus into functional vascular tubes appeared to be affected. Suppression of CD146 protein expression resulted in a circulation shunt that caused the circulation to by‐pass part of the caudal artery/vein system. The same vascular defects were recapitulated by using a second morpholino oligonucleotide. This morphant expressed a truncated CD146 protein with amino acids V32 to T57 at the N terminus deleted in an in‐frame manner. This region, therefore, is likely to contain elements critical for CD146 function. This study provides the first in vivo functional assessment of CD146 in embryonic development by showing that knockdown of CD146 protein expression severely hinders vascular development in zebrafish. Developmental Dynamics 232:232–244, 2005. © 2004 Wiley‐Liss, Inc.
Metalloprotease‐disintegrin ADAM8: Expression analysis and targeted deletion in mice
Authors: Kelly Kristine , Hutchinson Gillian , Nebenius‐Oosthuizen Daniela , Smith Andrew J.H. , Bartsch Jörg W. , Horiuchi Keisuke , Rittger Andrea , Manova Katia , Docherty Andy J.P. , Blobel Carl P.
Published: December 2004

ADAM8 (a disintegrin and metalloprotease 8, also referred to as MS2/CD156a) is a membrane‐anchored metalloprotease that was first identified in a macrophage cell line and has been implicated in neurodegenerative diseases. Here, we evaluated the expression of ADAM8 during mouse development and generated mice lacking ADAM8 (Adam8−/− mice). During early mouse development, ADAM8 is expressed by maternal cells in the decidua and by trophoblast derivatives of the embryo but not in the derivatives of the inner cell mass. At later stages, prominent expression of ADAM8 is seen in the embryo proper, in the gonadal ridge, thymus, developing cartilage and bone, brain and spinal cord, and in the mesenchyme in close proximity to the branch point between the jugular vein and developing lymphatic vessels. Examination of Adam8−/− mice, however, revealed no major defects in these or other structures during development or in adult tissues and no evident pathological phenotypes. Developmental Dynamics 232:221–231, 2005. © 2004 Wiley‐Liss, Inc.
The silent KIR3DP1 gene (CD158c) is transcribed and might encode a secreted receptor in a minority of humans, in whom the KIR3DP1, KIR2DL4 and KIR3DL1/KIR3DS1 genes are duplicated
Authors: Gómez‐Lozano Natalia , Estefanía Ernesto , Williams Fionnuala , Halfpenny Iris , Middleton Derek , Solís Rosario , Vilches Carlos
Published: December 2004

Killer‐cell Ig‐like receptors (KIR) are structurally and functionally diverse, and enable human NK cells to survey the expression of individual HLA class I molecules, often altered in infections and tumors. Multiple events of non‐reciprocal recombination have contributed to the rapid diversification of KIR. We show that ∼4.5% of the individuals of a Caucasoid population bear a recombinant allele of KIR3DP1, officially designed KIR3DP1*004, that associates tightly with gene duplications of KIR3DP1, KIR2DL4 and KIR3DL1/KIR3DS1. The KIR3DP1 gene is normally silent, but the recombinant allele carries a novel promoter sequence and, as a consequence, is transcribed in all tested individuals. Messenger RNA of KIR3DP1*004 is made up of six exons; of these, exons 1–5 are similar to, and spliced like, those encoding the leader peptide and Ig‐domains of KIR3D. By contrast, exon 6 is homologous to no other human KIR sequence, but only to possible homologs in chimpanzees and rhesus macaques, and encodes a short hydrophilic tail. The putative KIR3DP1*004 product, like those of the related genes LAIR‐2 and LILRA3/ILT6/LIR4, is predicted to be secreted to the extracellular medium rather than anchored to the cell membrane.

See accompanying Commentary: http://dx.doi.org/10.1002/eji.200425743
The KIR gene family: life in the fast lane of evolution
Authors: Uhrberg Markus
Published: December 2004

A hallmark of human NK cells is the expression of HLA class I‐specific killer‐cell immunoglobulin‐like receptors (KIR). An interesting facet of the KIR family is the unusual variability of the respective gene cluster, which is changing shape at an astonishing evolutionary pace. Not only do KIR genes come in different allelic variants, but the KIR locus has also gone through drastic contractions and expansions in recent evolutionary history, resulting in a wide variety of KIR haplotypes. A new study now reveals how an originally nonfunctional KIR pseudogene, KIR3DP1, is brought back to life in certain individuals via non‐reciprocal recombination between two different KIR haplotypes. This Commentary outlines how the unique architecture of the KIR locus facilitates the generation of new KIR haplotypes and discusses the functional relevance of it.

See accompanying article: http://dx.doi.org/10.1002/eji.200425493
A segregated method for compressible flow computation Part I: isothermal compressible flows
Authors: Hauke Guillermo , Landaberea Aitor , Garmendia Iñaki , Canales Javier
Published: December 2004

Traditionally, coupled methods have been employed for the computation of compressible flows, whereas segregated methods have been preferred for the computation of incompressible flows. Compared to coupled methods, segregated solvers present the advantage of reduced computer memory and CPU time requirements, although at the cost of an inferior robustness. Therefore, in a series of papers we present unified computational techniques to compute compressible and incompressible flows with segregated stabilized methods. The proposed algorithms have an increased robustness compared to existing techniques, while possessing additional benefits such as employing standard pressure boundary conditions. In this first part, the thermodynamics of isothermal, thermally perfect compressible flows is set up in the framework of symmetric systems and the corresponding segregated algorithms are introduced. Copyright © 2005 John Wiley & Sons, Ltd.
Resuscitating the cobweb cycle
Authors: Schenk‐Hoppé Klaus Reiner
Published: December 2004

This article shows that permanent fluctuations in the cobweb model—though inconsistent with a rational expectations equilibrium—can be justified as being rational when reinterpreting the model in the theory of rational beliefs. Copyright © 2004 John Wiley & Sons, Ltd.
Leadership, management, and governance
Authors: Block McLaughlin Judith
Published: December 2004

Presidents are expected to articulate vision, devise plans, and facilitate decision making. These different dimensions of the job are sometimes complementary, but they may also compete for the president's attention or suggest contradictory ways of proceeding.
Tandem mass spectrometric data–FAAH inhibitory activity relationships of some carbamic acid O‐aryl esters
Authors: Basso Elisa , Duranti Andrea , Mor Marco , Piomelli Daniele , Tontini Andrea , Tarzia Giorgio , Traldi Pietro
Published: December 2004

We have recently described a class of systemically active inhibitors of the intracellular activity of fatty acid amide hydrolase (FAAH) and traced extensive structure–activity relationships. These compounds, characterized by an N‐alkyl carbamic acid O‐aryl ester structure, exert potent anxiolytic‐like effects in animal models. In the present study, possible relationships between mass spectrometric parameters (related to the propensity of the C(O)O bond to be cleaved) and FAAH‐inhibitory potency were tested. With this aim, a set of our products was analyzed by electrospray ionization mass spectrometry and the protonated molecules were decomposed by low‐energy collisions. The experiments were performed by ion trap mass spectrometry, which led to a step‐by‐step energy deposition, thus favouring the lowest critical energy decomposition channels. For all compounds, breakdown curves relative to [MH]+ ions and to the fragment implying C(O)O bond cleavage were obtained. The crossing point between these curves was related to the energetics of decomposition and the values found for the investigated compounds were linearly correlated (r2 = 0.797) with their FAAH‐inhibitory activity. This indicates that the energetics of the C(O)O bond cleavage may be relevant in explaining FAAH inhibition. Copyright © 2004 John Wiley & Sons, Ltd.
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

The 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

Three 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

Fragmentation 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

In 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

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

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

No 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

The 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

We 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

This 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

New 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

A 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

Two 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

Aus 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

Colourless 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

A 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

Oxalamidine 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

[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.
Kristallstrukturen und spektroskopische Eigenschaften von 2λ3‐Phospha‐1, 3‐dionaten und 1, 3‐Dionaten des Calciums ‐ ein Vergleich am Beispiel der 1, 3‐Diphenyl‐ und 1, 3‐Di(tert‐butyl)‐Derivate
Authors: Becker Gerd , Niemeyer Mark , Mundt Otto , Schwarz Wolfgang , Westerhausen Matthias , Ossberger Manfred W. , Mayer Peter , Nöth Heinrich , Zhong Zhiyuan , Dijkstra Pieter J. , Feijen Jan
Published: December 2004

Der Wasserstoff‐Metall‐Austausch zwischen Dibenzoylphosphan und Calciumcarbid in Tetrahydrofuran (THF) ergibt nach Zusatz des Liganden 1, 3, 5‐Trimethyl‐1, 3, 5‐triazinan (TMTA) den als Kokristallisat mit Benzol isolierten zweikernigen Komplex Bis[(tmta‐N, N′, N″)calcium‐bis(dibenzoylphosphanid)] (1a). In ähnlicher Weise führt die Umsetzung von Bis(2, 2‐dimethylpropionyl)phosphan mit Bis(thf‐O)calcium‐bis[bis(trimethylsilyl)amid] in 1, 2‐Dimethoxyethan (DME) mit guten Ausbeuten zum ‐Bis(dme‐O, O′)calcium‐bis[bis(2, 2‐dimethylpropionyl)phosphanid] (1b). Über die Reaktion von Bis(thf‐O)calcium‐bis[tris(trimethylsilylmethyl)zinkat] mit dem Kohlenstoffanalogon 1, 3‐Diphenylpropan‐1, 3‐dion (Dibenzoylmethan) bzw. 2, 2, 6, 6‐Tetramethylheptan‐3, 5‐dion (Dipivaloylmethan) erhält man im gleichen Solvens das einkernige Bis(dme‐O, O′)calcium‐bis(dibenzoylmethanid) (2a) und das zweikernige (μ‐dme‐O, O′)Bis[(dme‐O, O′)calcium‐bis(dipivaloylmethanid)] (2b). Überraschenderweise setzt sich das dabei gebildete Dialkylzink mit den 1, 3‐Diketonaten 2a und 2b nicht weiter um. Schließlich kann aus dem unsymmetrischen Liganden 2‐(Methoxycarbonyl)cyclopentanon und Bis(thf‐O)calcium‐bis[bis(trimethylsilyl)amid] in Toluol der dreikernige Komplex 3 als Kokristallisat mit Tetrahydrofuran erhalten werden; der β‐Ketoester‐Ligand verbrückt als Anion ausschließlich über die Cyclopentanon‐Einheit.
Mitochondrial creatine kinase activity in patients with disturbed energy generation in muscle mitochondria
Authors: Smeitink J. , Ruitenbeek W. , Sengers R. , Wevers R. , v. Lith T. , Trijbels F.
Published: December 2004

Eleven patients with an established disturbance in muscle mitochondrial energy generation, in whom no defect in the pyruvate dehydrogenase complex or in the complexes of the respiratory chain could be detected, were investigated for a possible deficiency of mitochondrial creatine kinase (Mi‐CK) (EC 2.7.3.2). Four patients with a defect in one of the complexes of the respiratory chain were also investigated for Mi‐CK activity. In none of the investigated patients was Mi‐CK deficiency found. Surprisingly, two of the four patients with a defect in one of the respiratory chain complexes showed enhanced activity of Mi‐CK. It is concluded that Mi‐CK deficiency is not frequently found as a primary defect in patients with disturbance in mitochondrial energy generation, but more patients should be examined to allow a definite conclusion.
A family with visceral course of Niemann‐Pick disease, macular halo syndrome and low sphingomyelin degradation rate
Authors: Sperl W. , Bart G. , Vanier M. T. , Christomanou H. , Baldissera I. , Steichen‐Gersdorf E. , Paschke E.
Published: December 2004

We report a family with six patients suffering from a sphingomyelinase‐deficient form of Niemann‐Pick disease, all presenting with a visceral course of the disease. Retinal changes classified as macular halos in four members indicated neuronal storage and therefore an intermediate type of the disease. For further classification of the biochemical type, [choline‐methyl‐14C]sphingomyelin degradation studies were carried out in fibroblast cultures of all six members. The low degradation rates measured were similar to those usually found in the neuronopathic form (type A) of Niemann‐Pick disease. This family illustrates the broad heterogeneity within the sphingomyelinase deficiency group of the Niemann‐Pick disease. Apparently the finding of a low sphingomyelin degradation rate in fibroblast cultures does not necessarily imply a typical serious and lethal course of the disease.
Modeling flight activity and population dynamics of the pine engraver, Ips pini, in the Great Lakes region: effects of weather and predators over short time scales
Authors: Aukema Brian H. , Clayton Murray K. , Raffa Kenneth F.
Published: December 2004

Ascertaining the relative effects of factors such as weather and predation on population dynamics, and determining the time scales on which they operate, is important to our understanding of basic ecology and pest management. In this study, we sampled the pine engraver Ips pini (Say) (Coleoptera: Scolytidae) and its predominant predators Thanasimus dubius (F.) (Coleoptera: Cleridae) and Platysoma cylindrica (Paykull) (Coleoptera: Histeridae) in red pine plantations in Wisconsin, USA, over 2 years. We sampled both the prey and predators using flight traps baited with the synthetic aggregation pheromone of I. pini. Flight models were constructed using weather variables (temperature and precipitation), counts of bark beetles and their predators, and temporal variables to incorporate possible effects of seasonality. The number of I. pini per weekly collection period was temperature dependent and decreased with the number of predators, specifically T. dubius in 2001 and P. cylindrica in 2002. The number of predators captured each week was also weather dependent. The predators had similar seasonal phenologies, and the number of each predator species was positively correlated with the other. Including a term for the number of prey did not improve the model fits for either predator for either year. Our results suggest that exogenous weather factors strongly affect the flight activity of I. pini, but that its abundance is also affected by direct density‐dependent processes acting over weekly time scales. Adult predation during both colonization and dispersal are likely processes yielding these dynamics.
Glutamate‐evoked redox state alterations are involved in tissue transglutaminase upregulation in primary astrocyte cultures
Authors: Campisi A. , Caccamo D. , Li Volti G. , Currò M. , Parisi G. , Avola R. , Vanella A. , Ientile R.
Published: December 2004

The aim of this study was to evaluate the involvement of oxidative stress in glutamate‐evoked transglutaminase (TGase) upregulation in astrocyte cultures (14 DIV). A 24 h exposure to glutamate caused a dose‐dependent depletion of glutathione intracellular content and increased the ROS production in cell cultures. These effects were receptor‐mediated, as demonstrated by inhibition with GYKI 52466. The pre‐incubation with glutathione ethyl ester or cysteamine recovered oxidative status and was effective in significantly reducing glutamate‐increased tissue TGase. These data suggest that tissue TGase upregulation may be part of a biochemical response to oxidative stress induced by a prolonged exposure of astrocyte cultures to glutamate.
Depolarisation of the plasma membrane in the arsenic trioxide (As2O3)‐and anti‐CD95‐induced apoptosis in myeloid cells
Authors: Nolte Florian , Friedrich Oliver , Rojewski Markus , Fink Rainer H.A. , Schrezenmeier Hubert , Körper Sixten
Published: December 2004

Depolarisation of the plasma membrane has been shown to be actively regulated during lymphocyte‐apoptosis. Here, we present data about anti‐Fas and As2O3 induced depolarisation of myeloid U‐937 cells. Anti‐Fas but not As2O3‐induced depolarisation was significantly dependent on caspase‐activation. Na+‐fluxes contributed to the depolarisation in early stages of As2O3‐induced apoptosis, whereas the membrane potential in late stages depended on Cl−‐fluxes. Cl−‐channels also played an important role in the induction of cell shrinkage in As2O3‐induced apoptosis. However, none of these ions contributed significantly to anti‐Fas induced depolarisation. This indicates the existence of different mechanisms for apoptotic plasma membrane depolarisation within one cell type.
Role of upslope soil pore pressure on lateral subsurface storm flow dynamics
Authors: Uchida Taro , Asano Yuko , Mizuyama Takahisa , McDonnell Jeffery J.
Published: December 2004

The role of upslope soil pore water pressure on lateral subsurface storm flow dynamics is poorly understood. Further development of hillslope hydrologic models requires new understanding from field understanding. In particular, we need new, quantifiable measures that link upslope soil pore pressure and water table dynamics to the timing and volume of subsurface storm flow. Here we examine the relationship between hillslope‐scale pore pressure and lateral outflow from slope base using the fine‐temporal‐resolution hydrometric data (10 min interval) from two steep unchanneled concave hillslopes, one hillslope (Fudoji) covered by relatively high hydraulic conductivity sandy soil and the other (Toinotani) covered by relatively low hydraulic conductivity clay soil. In both hillslopes, pore pressures in the area close to the slope base were only weakly related to subsurface storm flow dynamics. During periods of storm flow production, hillslope discharge was strongly related to the cross‐sectional area of the upslope saturated layer. During slope seepage periods between events, hillslope discharge from the highly permeable hillslope was still related to the upslope cross‐sectional subsurface saturated area. However, during this same period at the low‐permeability site, hillslope discharge was not related to the upslope subsurface saturated area. Through intersite comparison we show that the soil matrix permeability has a large impact on the hydrological extension of preferential flow and hence the linkage between upslope pore pressure and subsurface storm flow dynamics.
Evidence of a recent magma dike intrusion at the slow spreading Lucky Strike segment, Mid‐Atlantic Ridge
Authors: Dziak Robert P. , Smith Deborah K. , Bohnenstiehl DelWayne R. , Fox Christopher G. , Desbruyeres Daniel , Matsumoto Haru , Tolstoy Maya , Fornari Daniel J.
Published: December 2004

Mid‐ocean ridge volcanic activity is the fundamental process for creation of ocean crust, yet the dynamics of magma emplacement along the slow spreading Mid‐Atlantic Ridge (MAR) are largely unknown. We present acoustical, seismological, and biological evidence of a magmatic dike intrusion at the Lucky Strike segment, the first detected from the deeper sections (>1500 m) of the MAR. The dike caused the largest teleseismic earthquake swarm recorded at Lucky Strike in >20 years of seismic monitoring, and one of the largest ever recorded on the northern MAR. Hydrophone records indicate that the rate of earthquake activity decays in a nontectonic manner and that the onset of the swarm was accompanied by 30 min of broadband (>3 Hz) intrusion tremor, suggesting a volcanic origin. Two submersible investigations of high‐temperature vents located at the summit of Lucky Strike Seamount 3 months and 1 year after the swarm showed a significant increase in microbial activity and diffuse venting. This magmatic episode may represent one form of volcanism along the MAR, where highly focused pockets of magma are intruded sporadically into the shallow ocean crust beneath long‐lived, discrete volcanic structures recharging preexisting seafloor hydrothermal vents and ecosystems.