bluuebunny/crossref_metadata_2025 huggingface dataset:
Beyond basic training: A model for developing mediator competence
Authors: Lieberman Etty , Foux‐Levy Yael , Segal Peretz
Published: February 2006

This article examines the effectiveness of a model system, developed under the auspices of the Ministry of Justice in Israel, for furthering the training of mediators. The model emphasizes training through practical experience and development of critical self‐assessment abilities, allowing individuals to recognize their personal strengths and weaknesses. The research concludes that there is a vital need for continuous training to facilitate both professional and personal growth of mediators.
What theory? How collaborative problem‐solving trainers use theory and research in training and teaching
Authors: Macfarlane Julie , Mayer Bernie
Published: February 2006

The authors describe an interview‐based research project that explored
the impact of theory and research on practice and training. The study found that
many training programs refer only occasionally to theory and research, instead
relying primarily on the wisdom and personal experience of the trainer. The
authors identify barriers to the integration of theory and research into
training programs, and propose new resources and strategies for overcoming these
obstacles.
Constant and intermittent high glucose enhances endothelial cell apoptosis through mitochondrial superoxide overproduction
Authors: Piconi Ludovica , Quagliaro Lisa , Assaloni Roberta , Da Ros Roberto , Maier Amabile , Zuodar Gianni , Ceriello Antonio
Published: February 2006

Background

It has been previously shown that hyperglycemia enhances free radical production, inducing oxidative damage, which in its turn activates the death pathways implicated in cell apoptosis and necrosis. But the possible involvement of this pathway in the hyperglycemia‐induced apoptosis of endothelial cells has not yet been reported.

Methods

To verify a possible connection between mitochondrial ROS production and apoptosis induced by both stable and oscillating high glucose, SOD, MnTBAP and TTFA was added to HUVEC cell culture medium. We measured nitrotyrosine and 8OHdG as oxidative stress parameters and Bcl‐2 expression and Caspase‐3 expression and activity as apoptosis indicators.

Results

Our results show that hyperglycemia, both stable or oscillating, increases oxidative stress and endothelial cell apoptosis through ROS overproduction at the mitochondrial transport chain level.

Conclusion

The prevention of mitochondrial oxidative damage seems to be a future important therapeutic strategy in diabetes. Copyright © 2006 John Wiley & Sons, Ltd.
In vivo and in vitro analysis of the vasculogenic potential of avian proepicardial and epicardial cells†
Authors: Guadix Juan A. , Carmona Rita , Muñoz‐Chápuli Ramón , Pérez‐Pomares José M.
Published: February 2006

Coronary vessel formation is a special case in the context of embryonic vascular development. A major part of the coronary cellular precursors (endothelial, smooth muscle, and fibroblastic cells) derive from the proepicardium and the epicardium in what can be regarded as a late event of angioblastic and smooth muscle cell differentiation. Thus, coronary morphogenesis is dependent on the epithelial–mesenchymal transformation of the proepicardium and the epicardium. In this study, we present several novel observations about the process of coronary vasculogenesis in avian embryos, namely: (1) The proepicardium displays a high vasculogenic potential, both in vivo (as shown by heterotopic transplants) and in vitro, which is modulated by vascular endothelial growth factor (VEGF) and basic fibroblast growth factor signals; (2) Proepicardial and epicardial cells co‐express receptors for platelet‐derived growth factor‐BB and VEGF; (3) Coronary angioblasts (found all through the epicardial, subepicardial, and compact myocardial layers) express the Wilms' tumor associated transcription factor and the retinoic acid‐synthesizing enzyme retinaldehyde‐dehydrogenase‐2, two markers of the coelomic epithelium involved in coronary endothelium development. All these results contribute to the development of our knowledge on the vascular potential of proepicardial/epicardial cells, the existent interrelationships between the differentiating coronary cell lineages, and the molecular mechanisms involved in the regulation of coronary morphogenesis. Developmental Dynamics 235:1014–1026, 2006. © 2006 Wiley‐Liss, Inc.
Neuronal leucine‐rich repeat 6 (XlNLRR‐6) is required for late lens and retina development in Xenopus laevis
Authors: Wolfe Adam D. , Henry Jonathan J.
Published: February 2006

Leucine‐rich repeat proteins expressed in the developing vertebrate nervous system comprise a complex, multifamily group, and little is known of their developmental function in vivo. We have identified a novel member of this group in Xenopus laevis, XlNLRR‐6, and through sequence and phylogenetic analysis, have placed it within a defined family of vertebrate neuronal leucine‐rich repeat proteins (NLRR). XlNLRR‐6 is expressed in the developing nervous system and tissues of the eye beginning at the neural plate stage, and expression continues throughout embryonic and larval development. Using antisense morpholino oligonucleotide (MO) ‐mediated knockdown of XlNLRR‐6, we demonstrate that this protein is critical for development of the lens, retina, and cornea. Reciprocal transplantation of presumptive lens ectoderm between MO‐treated and untreated embryos demonstrate that XlNLRR‐6 plays autonomous roles in the development of both the lens and retina. These findings represent the first in vivo functional analysis of an NLRR family protein and establish a role for this protein during late differentiation of tissues in the developing eye. Developmental Dynamics 235:1027–1041, 2006. © 2006 Wiley‐Liss, Inc.
Multicolor in vivo time‐lapse imaging at cellular resolution by stereomicroscopy
Authors: Distel Martin , Babaryka Andreas , Köster Reinhard W.
Published: February 2006

Intravital time‐lapse imaging has altered significantly many long‐standing rules of biological mechanisms, but being apparatus‐intense and laborious, time‐lapse imaging remained mostly restricted to specialized labs. We show that recently introduced fully automated fluorescence stereomicroscopes represent cost‐effective but powerful means of imaging dynamic events ranging from observing embryogenesis over several days to detailed tissue rearrangements and fast blood cell rolling in vivo. When combined with deconvolution approaches, even subcellular resolution in several colors can be achieved. Using three‐dimensional image recording, we show the spatial reconstruction of expression patterns. Furthermore, by combining three‐dimensional image recording over time with subsequent deconvolution analysis, we demonstrate that subcellular dynamics such as axonal pathfinding in vivo can be resolved. These findings promise that time‐lapse imaging using a stereomicroscope will become a hands‐on standard method for phenotype analysis in many fields of biology. Developmental Dynamics 235:1100–1106, 2006. © 2006 Wiley‐Liss, Inc.
Dlk1 expression marks developing endothelium and sites of branching morphogenesis in the mouse embryo and placenta
Authors: Yevtodiyenko Aleksey , Schmidt Jennifer V.
Published: February 2006

The protein product of the Delta‐like 1 (Dlk1) gene belongs to the Delta‐Notch family of signaling molecules, proteins involved in cell fate determination in many tissues during development. The DLK1 protein is believed to function as a growth factor, maintaining the proliferative state of undifferentiated cells, and is usually down‐regulated as immature cells differentiate. The expression pattern of the DLK1 protein has been described in certain human tissues; however, Dlk1 expression is not well understood in the mouse, the most tractable mammalian genetic model system. To better understand the role of Dlk1 in embryonic development, the tissue‐specific expression pattern of Dlk1 mRNA during mouse embryogenesis was analyzed by in situ hybridization. In embryonic day 12.5 (e12.5) embryos, high levels of Dlk1 were found in the developing pituitary, pancreas, lung, adrenal, and many mesodermally derived tissues. Strikingly, Dlk1 expression also marks the growing branches of organs that develop through the process of branching morphogenesis. At e16.5, Dlk1 expression is down‐regulated in most tissues but remains in the pituitary, the adrenal gland, and in skeletal muscle. In the placenta, expression of Dlk1 is detected in endothelial cells lining the fetal blood vessels of the labyrinth. This pattern is distinct from that seen in the human placenta and suggests a role for Dlk1 in regulating maternal–fetal interactions. Developmental Dynamics 235:1115–1123, 2006. © 2006 Wiley‐Liss, Inc.
Anatomy of T cell autoimmunity to myelin oligodendrocyte glycoprotein (MOG): Prime role of MOG44F in selection and control of MOG‐reactive T cells in H‐2b mice
Authors: Ben‐Nun Avraham , de Rosbo Nicole Kerlero , Kaushansky Nathali , Eisenstein Miriam , Cohen Lydia , Kaye Joel F. , Mendel Itzhack
Published: February 2006

Myelin oligodendrocyte glycoprotein (MOG) is an important myelin target antigen, and MOG‐induced EAE is now a widely used model for multiple sclerosis. Clonal dissection revealed that MOG‐induced EAE in H‐2b mice is associated with activation of an unexpectedly large number of T cell clones reactive against the encephalitogenic epitope MOG35–55. These clones expressed extremely diverse TCR with no obvious CDR3α/CDR3β motif(s). Despite extensive TCR diversity, the cells required MOG40–48 as their common core epitope and shared MOG44F as their major TCR contact. Fine epitope‐specificity analysis with progressively truncated peptides suggested that the extensive TCR heterogeneity is mostly related to differential recognition of multiple overlapping epitopes nested within MOG37–52, each comprised of a MOG40–48 core flanked at the N‐ and/or the C‐terminus by a variable number of residues important for interaction with different TCR. Abrogation of both the encephalitogenic potential of MOG and T cell reactivity against MOG by a single mutation (MOG44F/MOG44A), together with effective down‐regulation of MOG‐induced EAE by MOG37–44A–52, confirmed in vivo the primary role for MOG44F in the selection/activation of MOG‐reactive T cells. We suggest that such a highly focused T cell autoreactivity could be a selective force that offsets the extensive TCR diversity to facilitate a more “centralized control” of pathogenic MOG‐related T cell autoimmunity.
Endogenous cortisol determines the circadian rhythm of lipopolysaccharide‐ but not lipoteichoic acid‐inducible cytokine release
Authors: Hermann Corinna , von Aulock Sonja , Dehus Oliver , Keller Moritz , Okigami Hiromi , Gantner Florian , Wendel Albrecht , Hartung Thomas
Published: February 2006

To investigate the circadian rhythm of inducible cytokine release and a potential pacemaker role of endogenous cortisol, cortisol levels as well as cytokine release from ex vivo LPS‐stimulated blood were assessed at 4‐h intervals over 24 h in 11 volunteers. We found a significant diurnal variation for IFN‐γ and IL‐8, and a tendency for TNF, all inversely correlated to the serum cortisol levels, but no evidence for such a rhythm for IL‐1β and IL‐6. In vitro IC50 values for cytokine inhibition by hydrocortisone (HC) corresponded to the observed rank order for circadian rhythmicity. mRNA analyses revealed that this was due to a reduction of gene transcription. These effects of HC were significantly reversed by the glucocorticoid receptor antagonist RU486. Supplementation of HC in vivo to maintain morning cortisol levels throughout the day blunted the circadian rhythm of ex vivo LPS‐induced cytokines. Surprisingly, no significant diurnal variation for any investigated cytokine was found in the same volunteer group upon stimulation with lipoteichoic acid (LTA), the gram‐positive counterpart to LPS. Furthermore, 10–50‐fold higher HC concentrations as compared to LPS were required to block LTA‐induced cytokine release. LTA, in contrast to LPS, failed to activate Jun kinase, a reported target for HC action.
Pathogen‐specific TLR signaling in mucosa: Mutual contribution of microbial TLR agonists and virulence factors
Authors: Sirard Jean‐Claude , Bayardo Mariela , Didierlaurent Arnaud
Published: February 2006

Detection of microorganisms through microbe‐associated molecular patterns (MAMP) by Toll‐like receptors (TLR) is crucial to trigger protective immunity. In the mucosa, sentinel cells are exposed to MAMP from both pathogens and commensals; however, the TLR response is tightly controlled to avoid inflammation in response to commensals. Uropathogenic Escherichia coli (UPEC) trigger innate responses during urinary tract infection in a TLR4‐dependent and CD14‐independent manner. UPEC express virulence factors, such as type 1 fimbriae and/or P fimbriae, allowing bacterial attachment to the epithelium. In this issue of the European Journal of Immunology, Fisher et al. show that fimbriae are required to induce a TLR4‐specific epithelial response. Depending on the fimbriae expressed by UPEC, different adaptor molecules are involved in TLR4 signaling. These data add to the recent body of evidence suggesting that TLR responses are regulated by co‐receptors, such as receptors for virulence factors. In conclusion, the “pathogenic” TLR stimulation provides a novel way for the host to ignore commensal bacteria.

See accompanying article http://dx.doi.org/10.1002/eji.200535149
Charge‐Transfer Phase Transition and Ferromagnetism of Iron Mixed‐Valence Complexes (n‐CnH2n+1)4N[FeIIFeIII(dto)3] (n = 3–6; dto = C2O2S2)
Authors: Itoi Miho , Ono Yuuki , Kojima Norimichi , Kato Kenichi , Osaka Keiichi , Takata Masaki
Published: February 2006

The iron mixed‐valence complex, (n‐C3H7)4N[FeIIFeIII(dto)3] (dto = dithiooxalato) shows a charge‐transfer (CT) phase transition at TCT = 122.4 K. In the vicinity of TCT, the spin state changes from FeII (S = 2) – FeIII (S = 1/2) (high‐temperature phase: HTP) to FeII (S = 0) – FeIII (S = 5/2) (low‐temperature phase: LTP) accompanied by a charge transfer between FeII and FeIII. This complex also undergoes a ferromagnetic transition at 7 K in the LTP. In order to investigate the mechanism of the CT phase transition and the ferromagnetism, we have systematically synthesized (n‐CnH2n+1)4N[FeIIFeIII(dto)3] (n = 3–6), and have investigated their physical properties by magnetic susceptibility, powder X‐ray diffraction measurements, and ESR spectroscopy. The compounds (n‐CnH2n+1)4N[FeIIFeIII(dto)3] (n = 3–6) display ferromagnetic phase transitions at 7 K, 7 K (& 13 K), 19.5 K, and 22 K, respectively. For n = 3 and 4, the CT phase transitions take place at TCT ≈ 120 K and TCT ≈ 140 K, respectively. For n = 5 and 6, on the other hand, the CT phase transition does not occur, and the spin configuration of FeII (S = 2) and FeIII (S = 1/2) corresponding to the HTP for n = 3 and 4 is stable between 2 K and 300 K. The cation size of (n‐CnH2n+1)4N+ (n = 3–6) acts as an effective internal pressure which induces the CT phase transition and the ferromagnetic ordering in the [FeIIFeIII(dto)3]–∞ layer. We also discuss the mechanism of the CT phase transition and the ferromagnetism induced by the charge‐transfer interaction between FeII and FeIII. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Synthesis, Structures, and Luminescent Properties of Aluminum Complexes with Chelating Anilido‐Imine Ligands
Authors: Liu Xiaoming , Xia Hong , Gao Wei , Ye Ling , Mu Ying , Su Qing , Ren Yi
Published: February 2006

The syntheses of a number of four‐coordinate aluminum complexes, ortho‐C6H4(NAr′)(CH=NAr′′)AlCl2 [Ar′ = Ar′′ = 2,6‐iPr2C6H3 (2a); Ar′ = 2,6‐iPr2C6H3, Ar′′ = 2,6‐Me2C6H3 (2b); Ar′ = Ar′′ = 2,6‐Me2C6H3 (2c); Ar′ = p‐MeC6H4, Ar′′ = 2,6‐iPr2C6H3 (2d)], are described. Complexes 2a–2d were synthesized from the reaction of AlCl3 with lithium salt of the corresponding ligand at room temperature. All complexes were characterized by 1H and 13C NMR spectroscopy and molecular structures of complexes 2a, 2b, and 2d were determined by X‐ray crystallography. Luminescent properties of complexes 2a–2d in both solution and the solid state were studied. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Optical Properties of the Perovskite Solid Solution LaTiO2N–ATiO3(A = Sr, Ba)
Authors: Cheviré François , Tessier Franck , Marchand Roger
Published: February 2006

Starting from the colored oxynitride LaTiO2N, new perovskite‐type solid solutions have been evidenced in the systems La1–xAxTiO2+xN1–x (A = Sr, Ba) by ammonolysis at 950 °C of the corresponding oxide precursors prepared by the molten salt route. The color of the resulting powders varies progressively from the brown of LaTiO2N to the white of the oxide with a decrease in both the nitrogen and lanthanum contents. The optical absorption was characterized by diffuse reflectance. The nonlinear variation of the optical bandgap may result from the competition between the variation of the inductive effect between lanthanum and strontium, structural changes, and the difference in electronegativity between nitrogen and oxygen. For the compounds with a low nitrogen content the observed green shade is attributed to the presence of a nitrogen‐rich secondary phase: TiOxNy in which titanium presents a mixed‐valence state. Taking advantage of a chimie douce process, the amorphous citrate route, the highest oxidation state of titanium was stabilized until x = 0.9 in the La0.1Sr0.9Ti(O,N)3 phase giving the powder a bright yellow color (Eg = 2.49 eV). (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Atmospheric Pressure Chemical Vapour Deposition of NbSe2 Thin Films on Glass
Authors: Boscher Nicolas D. , Carmalt Claire J. , Parkin Ivan P.
Published: February 2006

Atmospheric pressure chemical vapour deposition (APCVD) of niobium selenide films on glass substrates was achieved by reaction of di‐tert‐butyl selenide with NbCl5 at 250–600 °C. X‐ray diffraction showed that the NbSe2 films were crystalline and of the 2Ha poly‐type with cell constants close to those expected (a = 3.44 Å; c = 12.58 Å). Marked preferred orientation along either (101) or (200) was noted at higher deposition temperature and this unexpectedly varied depending on distance from the reactor inlet. The films produced at 600 °C showed exactly the Nb/Se ratio expected for NbSe2 by energy dispersive analysis by X‐rays. The films deposited at the substrate temperatures of 500 °C or less were selenium rich with a niobium to selenium ratio of 1:2.5. The films produced at 600 °C were dark‐green, powdery and poorly adhesive. The films produced at 500 °C and below were dark‐brown matte in appearance, they passed the Scotch tape test, but could be scratched with a steel scalpel. SEM showed that the films were composed of plate‐like crystals, which become longer and thicker with increasing deposition temperature. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Oxidative Addition of Cl2, HClO to Square‐Planar PtII Complexes: Synthesis and Structural Characterization of Platinum(II) and Platinum(IV) Bis(amidate) Complexes
Authors: Liu Fenghui , Chen Wanzhi
Published: February 2006

New bis(amidate)platinum(II) complexes with the general formula cis‐[Pt(RNH2)2(NHCOtBu)2] were prepared by the hydrolysis of the corresponding cis‐[Pt(RNH2)2(tBuCN)2]2+ complex. The bis(amidate)platinum(IV) complexes with the formula trans,cis,cis‐[PtCl2(RNH2)2(NHCOtBu)2] (5: R = H, 6: R = Et), trans,cis,cis‐[PtCl(OH)(RNH2)2(NHCOtBu)2] (8: R = H, 9: R = Et, and 10: 2 R = 1,2‐cHex), and mono(amidate) complex mer‐[PtCl3(DACH)(NHCOtBu)2] (7, DACH = trans‐1,2‐diaminocyclohexane) have been generated selectively by the oxidative addition of Cl2 and HClO to the corresponding platinum(II) complexes, [Pt(RNH2)2(NHCOtBu)2], in water. All the prepared compounds were characterized byelemental analyses and 1H and 195Pt NMR spectroscopy.The structures of trans,cis,cis‐[PtCl2(NH3)2(NHCOtBu)2] (5), trans,cis,cis‐[PtCl2(EtNH2)2(NHCOtBu)2] (6), mer‐[PtCl3(DACH)(NHCOtBu)] (7), and trans,cis,cis‐[PtCl(OH)(DACH)(NHCOtBu)2] (10) have been confirmed by X‐ray diffraction analyses. The structures of these platinum(IV) complexes adopt an octahedral geometry. The Pt–N, Pt–O, and Pt–Cl distances are in the expected ranges. These complexes are rare examples of bis(amidate)‐ and mono(amidate)platinum(IV) complexes. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Counteranion‐Induced Formation of cis and trans Singly and Doubly H2biim‐Bridged Di‐, Hexa‐, and Polymeric Ag–H2biim Complexes
Authors: Sang Rui‐Li , Xu Li
Published: February 2006

A series of cis and trans singly and doubly H2biim‐bridged di‐, hexa‐, and polymeric complexes of silver(I) (H2biim = 2,2′‐biimidazole), namely [Ag2(μ‐H2biim)2]SO4·2H2O (1),[Ag2(μ‐H2biim)2(μ‐ox)]n (2), [Ag6(μ‐H2biim)5(H2biim)2](ClO4)4(CH3CO2)2·2H2O (3), and [Ag(μ‐H2biim)(nicotinate)]n (4) have been synthesized and characterized by X‐ray crystallography and IR and photoluminescence spectroscopy. The structural topology of the Ag–H2biim system is determined by the charge of the counteranions. Thus, dianionic counterions facilitate the formation of dimeric structures driven by the charge‐balance requirement, whereas a monoanionic counterion favors the formation of helical structures. Counteranions of larger size lead to either finite helical structures or a trans arrangement of the coordinating nitrogen atoms because of steric requirements. Organic counteranions with a strong coordination ability bind to the Ag+ ions while inorganic counteranions are uncoordinated. The argentophilic attraction is not dominant in this system. Examination of the luminescent properties of H2biim and compounds 1–4 indicates that the fluorescence emission of H2biim is effectively shifted upon metal coordination. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Phosphorus‐Containing Dendrons: Synthesis, Reactivity, Properties, and Use as Building Blocks for Various Dendritic Architectures
Authors: Caminade Anne‐Marie , Maraval Alexandrine , Majoral Jean‐Pierre
Published: February 2006

Dendrons, also called dendritic wedges, are a special variety of dendrimers possessing one or two functional groups at the core, in addition to the numerous functional end groups. This review is focused on phosphorus‐containing dendrons, which are dendrons built with one phosphorus atom at each branching point. Their synthesis, reactivity and properties are described, with emphasis on their use as building blocks for the elaboration of very complex and original dendritic architectures. Electrochemical and catalytic properties, as well as examples in the field of materials are also given. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Analysis of the Synergistic Effect of Carbonylplatinum Complexes on the Iridium‐Catalysed Carbonylation of Methanol to Acetic Acid
Authors: Gautron Samuel , Lassauque Nicolas , Le Berre Carole , Serp Philippe , Azam Laurent , Giordano Roberto , Laurenczy Gábor , Thiébaut Daniel , Kalck Philippe
Published: February 2006

High‐pressure NMR mechanistic investigations into the promoting role of dicarbonyldiiodoplatinum complex in the iridium‐catalysed carbonylation of methanol to acetic acid are consistent with iodide abstraction from the [IrI3(CH3)(CO)2]– resting state species by [PtI2(CO)2], unbolting the rate‐limiting migratory CO insertion step. A new [Ir–Pt] heterodimetallic complex, which presumably represents the key species involved in the abstraction of I–, has been characterised by NMR in tandem with FAB‐MS. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Hypercoordinated Organotin(IV) Halides Containing 2‐(Me2NCH2)C6H4 Groups: {2‐(Me2NCH2)C6H4}2SnX2 (X = F, Cl, Br, I) and {2‐(Me2NCH2)C6H4}R2SnX (R = Me, Ph; X = F, Cl, Br, I) and Their Solution Behaviour and Solid‐State, Hydrogen‐Bonding‐Based Supramolecular Architecture
Authors: Varga Richard A. , Rotar Adina , Schürmann Markus , Jurkschat Klaus , Silvestru Cristian
Published: February 2006

The hypercoordinated di‐ and triorganotin(IV) chlorides [{2‐(Me2NCH2)C6H4}2SnCl2] (1a) and [{2‐(Me2NCH2)C6H4}R2SnCl] [R = Me (2a), Ph (3a)] were prepared by treating SnCl4 or R2SnCl2 with [Li{2‐(Me2NCH2)C6H4}]. Halide‐exchange reactions between the organotin(IV) chlorides and the appropriate potassium halides gave [{2‐(Me2NCH2)C6H4}2SnX2] [X = F (1b), I (1d)], [{2‐(Me2NCH2)C6H4}Me2SnX] [X = F (2b), Br (2c), I (2d)] and [{2‐(Me2NCH2)C6H4}Ph2SnX] [X = F (3b), I (3d)]. Their solution behaviour was investigated by multinuclear (1H, 13C, 19F and 119Sn) NMR spectroscopy, including variable‐temperature studies. Single‐crystal X‐ray diffraction analyses revealed that the strong intramolecular coordination of the nitrogen atom from the pendant CH2NMe2 group to tin induces chirality. The influence of the identity and the number of the halogen atoms and the organic substituents at tin is discussed in relation with the hydrogen‐bonding network, which results in different supramolecular architectures in the crystal. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Boron–Nitrogen Adducts of 1,3,5‐Triaza‐7‐phosphaadamantane (PTA): Synthesis, Reactivity, and Molecular Structure
Authors: Frost Brian J. , Mebi Charles A. , Gingrich Phillip W.
Published: February 2006

Addition of BH3 to 1,3,5‐triaza‐7‐phosphaadamantane (PTA) leads to the formation of the first coordination complex of PTA in which a nitrogen and not the phosphorus of PTA is involved in the bonding. Multinuclear NMR spectroscopy, X‐ray crystallography, and computational chemistry are utilized in the characterization of the products. Crystal structures of PTA–BH3 (1) and O=PTA–BH3 (2) adducts are described. In addition a coordination polymer, [CpRu(PTA)2Cl(Ph3B3O3)]n (3), resulting from Lewis acid–base adduct formation between the PTA ligands of CpRu(PTA)2Cl and the product of the cyclocondensation of phenylboronic acid is described. The polymeric compound 3 was also characterized by X‐ray crystallography. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Atom Assignment in Solid‐State Structures on the Basis of X‐ray Crystallography and DFT Calculations – A Case Study on a Molecular Cu–Sb Alloy
Authors: Ahlrichs Reinhart , Fenske Dieter , Rothenberger Alexander , Schrodt Claudia , Wieber Stephan
Published: February 2006

The structure determination of the molecular Cu‐Sb alloy [Cu28Sb12(PEt3)12{Sb(SiMe3)2}2] was performed by DFT‐assisted X‐ray crystallography, a powerful combination of methods, widely applicable. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Impedance Characterization of a Quartz Crystal Microbalance
Authors: Vanýsek Petr , Delia Laura A.
Published: February 2006

The impedance characteristics of the quartz crystal used in quartz crystal microbalance is considered a higher dimension of information that can be obtained in addition to the resonant frequency change of the crystal. The impedance allows calculating the quality factor of the oscillator that is very closely related to the mechanical rigidity of the material, which is adsorbed or deposited on the quartz crystal. This paper concentrates on utilizing an impedance analyzer, often found in electroanalytical laboratories, instead of the usually required network analyzer.
Effects of Strong Ion‐Pairing on the Electrochemical Reduction of Cyclooctatetraene in Tetrahydrofuran in the Presence of Lithium Ion. Peak Coalescence Does Not Imply Potential Inversion
Authors: Fry Albert J.
Published: February 2006

The first study of the voltammetric reduction of cyclooctatetraene (COT) in tetrahydrofuran (THF) in the presence of lithium ion is reported. A single wave is observed at −2.23 V vs. Ag/0.1 M AgNO3. Density functional calculations have been carried out on a variety of COT/Li/THF species in order to clarify the nature and role of ion pairing in this system. The dominant species in solution are the COT/Li/(THF)2 anion radical and the COT/Li2/(THF)4 dianion. Computer simulations have been carried out to further understand the effects of ion pairing on the reduction. The simulations show that coalescence of two waves into one can occur in the presence of strong ion pairing even when the second reduction potential is negative of the first.
The Direct Electrochemical Oxidation of Ammonia in Propylene Carbonate: A Generic Approach to Amperometric Gas Sensors
Authors: Ji Xiaobo , Banks Craig E. , Compton Richard G.
Published: February 2006

The direct electrochemical oxidation of ammonia in propylene carbonate is reported for the first time. The voltammetric responses at glassy carbon, boron‐doped diamond, edge and basal plane pyrolytic graphite electrodes are explored and compared with the outcome indicating that the optimum electrode substrate for analytical purposes in this solvent is glassy carbon. Proof‐of‐concept is shown for the amperometric detection of ammonia using basal plane pyrolytic graphite electrodes abrasively modified with glassy carbon spheres. Given the significantly lower vapor pressure of propylene carbonate in comparison to water the implications for extending the life‐time of practical sensors are evident. Propylene carbonate shows a wide potential window with glassy carbon electrodes permitting this approach to be used for a potential diversity of gaseous analytes.
Amperometric Sensor for Trichloroacetic Acid Based on Myoglobin/Colloidal Gold Nanoparticles Immobilized in Titania Sol–Gel Matrix
Authors: Li Yancai , Yang Weiwei , Bai Yu , Sun Changqing
Published: February 2006

A new amperometric sensor for the determination of trichloroacetic acid (TCA) was developed based on the immobilization of myoglobin/colloidal gold nanoparticles in titania sol–gel matrix. The sensor showed a pair of well‐defined and nearly reversible cyclic voltammetric peaks for the Mb Fe(III)/Fe(II) with a formal potential (E°′) of −335 mV and a peak‐to‐peak separation was 61 mV vs. Ag/AgCl (3.0 M KCl) at 100 mV s−1 in 0.1 M pH 7.0 phosphate buffer solutions (PBS). The formal potential of the Mb Fe(III)/Fe(II) couple shifted linearly with the pH with a slope of −51.3 mV/pH, indicating that an electron transfer accompanies single‐proton transportation. The sensor displayed a good electrocatalytic response toward the reduction of TCA and the catalytic mechanism was also discussed. The overpotential for the reduction of TCA was lowered by at least 0.8 V compared with that obtained at bare glassy carbon electrode. The linear range spans the concentration of TCA from 2.0×10−6 to1.2×10−5 M and the detection limit was 1.2×10−7 M. In addition, the stability, repeatability and selectivity of the sensor were also evaluated.
Electrochemical Reduction of 4,4′‐(2,2,2‐Trichloroethane‐1,1‐diyl)‐ bis(chlorobenzene) (DDT) and 4,4′‐(2,2‐Dichloroethane‐1,1‐diyl)‐ bis(chlorobenzene) (DDD) at Carbon Cathodes in Dimethylformamide
Authors: Mubarak Mohammad S. , Gach Philip C. , Peters Dennis G.
Published: February 2006

In dimethylformamide containing tetramethylammonium tetrafluoroborate, cyclic voltammograms for reduction of 4,4′‐(2,2,2‐trichloroethane‐1,1‐diyl)bis(chlorobenzene) (DDT) at a glassy carbon cathode exhibit five waves, whereas three waves are observed for the reduction of 4,4′‐(2,2‐dichloroethane‐1,1‐diyl)bis(chlorobenzene) (DDD). Bulk electrolyses of DDT and DDD afford 4,4′‐(ethene‐1,1‐diyl)bis(chlorobenzene) (DDNU) as principal product (67–94%), together with 4,4′‐(2‐chloroethene‐1,1‐diyl)bis(chlorobenzene) (DDMU), 1‐chloro‐4‐styrylbenzene, and traces of both 1,1‐diphenylethane and 4,4′‐(ethane‐1,1‐diyl)bis(chlorobenzene) (DDO). For electrolyses of DDT and DDD, the coulometric n values are essentially 4 and 2, respectively. When DDT is reduced in the presence of a large excess of D2O, the resulting DDNU and DDMU are almost fully deuterated, indicating that reductive cleavage of the carbon–chlorine bonds of DDT is a two‐electron process that involves carbanion intermediates. A mechanistic scheme is proposed to account for the formation of the various products.
Efficient reduction of fault current through the grounding grid of a substation supplied by an overhead line
Authors: Popović Ljubivoje M.
Published: February 2006

The paper presents a directly applicable and reasonably accurate method for the evaluation of the effects of the counterpoise, the measure for the reduction of the fault current through the substation grounding grid. Under practical conditions the magnitude of the current diverted from a substation grounding grid by the counterpoise conductor is a very complex function of the self and mutual impedances of overhead and underground conductors, substation grounding impedance, transmission line towers resistance, proximity effect between the grounding grid and the counterpoise conductor, as well as on many other factors of lower order. Therefore certain idealizations and simplification of the real physical model were indispensable to develop the mathematical model presented here. The obtained expressions are mostly based on the general equations of a line represented by its lumped parameters and the general equations of uniform ladder circuits. Copyright © 2006 John Wiley & Sons, Ltd.
An experimental study on the transformer coil leakage current
Authors: Wahab Mohamed A. A. , Hamada M. M. , Zeitoun A. G. , Ismail G.
Published: February 2006

This paper is concerned with the transformer coil dc leakage current under different conditions. These conditions include in‐air, and in‐oil leakage, currents with or without artificial coil deposits. In‐oil leakage, currents are investigated when the coil is immersed in new or used transformer oil at different temperatures. The results showed that the leakage current increases with the increase in the applied voltage and oil temperatures. The rate of increase in leakage current with temperature depends on the transformer oil and coil conditions. The in‐oil leakage currents are higher than those obtained in air. The leakage currents measured in used oil are higher than those resulted in new oil. Copper deposits cause higher values of leakage current than iron deposits for the same medium, applied voltage and temperature. Deposits increase the leakage current for different coil surrounding media. A linear model for the leakage current as a function of the applied voltage under different conditions has been found and its validity has been justified by statistical consideration. The parameters of this model account for various experimental conditions. Copyright © 2006 John Wiley & Sons, Ltd.
Static and dynamic approaches for analyzing voltage stability
Authors: Lei X. , Retzmann D.
Published: February 2006

Voltage stability analysis always involves a large number of devices with various dynamic characteristics in power system. For properly capturing static and dynamic behaviors providing insights into characteristics of the voltage stability of the system, different system models are established for different time‐scale studies. In this paper, relevant system models are discussed taking into account load characteristics. Based on these models, different approaches such as static analysis, time‐domain simulation and quasi‐steady state (QSS) approximation are implemented into a simulation program, which is used as a comprehensive tool for analyzing voltage stability. By complementary use of these approaches with the simulation program, voltage collapse stresses of the system under a critical operating condition can be analysed in steady state, and impacts of special events on the voltage stability can also be simulated with time‐domain simulations. For time‐domain simulations, a full system model and a QSS approximation can be adopted for capturing different forms of instability mechanisms. A test system is used to demonstrate the feasibility and effectiveness of the approaches implemented. Copyright © 2006 John Wiley & Sons, Ltd.
Acoustic noise generated by air power reactor in open‐air substation
Authors: Lilien Jean‐Louis
Published: February 2006

Air power reactors are often used in substations for different purposes such as fault current limiter, reactive power consumption, harmonic filtering, and grounding impedance. They are also used in test laboratories for electric material testing. If the basic design is in relation with its electric duties, the design rules also include some restrictions for thermodynamics, structural dynamics, and acoustics. The full interaction between these four engineering fields is particularly important for acoustic noise produced by the reactor. This noise level is limited by international rules. The aim of this paper is to present a simple analytical method to evaluate the acoustics of such air power reactors and to compare such a method with more sophisticated numerical evaluations. Last but not least, some trends in noise control methods are described. Detailed tests results are presented for validation of the proposed method to properly evaluate the acoustics of single core reactors. Copyright © 2006 John Wiley & Sons, Ltd.
An introduction to social network analysis
Authors: Durland Maryann M. , Fredericks Kimberly A.
Published: February 2006

The application of social network analysis methodologies is relatively new for mainstream evaluation and has yet to be fully explored in this discipline. This chapter discusses how and why SNA is appropriate for evaluation practice.
Exploring and understanding relationships
Authors: Durland Maryann M.
Published: February 2006

This chapter provides an overview of the methodology of social network analysis (SNA) and a framework for understanding the next four chapters, which are case studies illustrating the application of SNA.
An evaluation of communication among high school faculty using network analysis
Authors: Kochan Susan , Teddlie Charles
Published: February 2006

This chapter focuses on the use of social network analysis in the evaluation of K–12 educational programs.
Network analysis of a demonstration program for the developmentally disabled
Authors: Fredericks Kimberly A.
Published: February 2006

This chapter provides a network analysis of a disability demonstration program within a large state and compares its results with the results of a more traditional evaluation of the program.
Application of network analysis in evaluating knowledge capacity
Authors: Birk Sandra M.
Published: February 2006

This chapter describes the application of social network analysis to evaluate the knowledge capacity of a business initiative program at a government‐owned national laboratory.
A formative evaluation of the integration of two departments
Authors: Durland Maryann M.
Published: February 2006

This chapter's case was a formative evaluation to guide the effectiveness and efficiency of a planned integration. The system network analysis application is illustrative of organizational structures.
The value of social network analysis in health care delivery
Authors: Introcaso David M.
Published: February 2006

This chapter frames the use of social network analysis in understanding knowledge diffusion and discusses current uses of this methodology within a government agency.
Next steps for nodes, nets, and SNA analysis in evaluation
Authors: Durland Maryann M. , Fredericks Kimberly A.
Published: February 2006

This chapter presents some final thoughts about the future of social network analysis within the field of evaluation.
Motion correction and the use of motion covariates in multiple‐subject fMRI analysis
Authors: Johnstone Tom , Ores Walsh Kathleen S. , Greischar Larry L. , Alexander Andrew L. , Fox Andrew S. , Davidson Richard J. , Oakes Terrence R.
Published: February 2006

The impact of using motion estimates as covariates of no interest was examined in general linear modeling (GLM) of both block design and rapid event‐related functional magnetic resonance imaging (fMRI) data. The purpose of motion correction is to identify and eliminate artifacts caused by task‐correlated motion while maximizing sensitivity to true activations. To optimize this process, a combination of motion correction approaches was applied to data from 33 subjects performing both a block‐design and an event‐related fMRI experiment, including analysis: (1) without motion correction; (2) with motion correction alone; (3) with motion‐corrected data and motion covariates included in the GLM; and (4) with non–motion‐corrected data and motion covariates included in the GLM. Inclusion of covariates was found to be generally useful for increasing the sensitivity of GLM results in the analysis of event‐related data. When motion parameters were included in the GLM for event‐related data, it made little difference if motion correction was actually applied to the data. For the block design, inclusion of motion covariates had a deleterious impact on GLM sensitivity when even moderate correlation existed between motion and the experimental design. Based on these results, we present a general strategy for block designs, event‐related designs, and hybrid designs to identify and eliminate probable motion artifacts while maximizing sensitivity to true activations. Hum. Brain Mapp, 2006. © 2006 Wiley‐Liss, Inc.
Neuregulin regulates the formation of radial glial scaffold in hippocampal dentate gyrus of postnatal rats
Authors: Zheng Chang‐Hong , Feng Linyin
Published: February 2006

In the rodent hippocampus, the radial glial scaffold consists of radial glial cells (RGCs) and plays important roles in neurogenesis in this area after birth. However, the mechanisms that maintain the radial glial scaffold in the postnatal dentate gyrus (DG) area remain elusive. In the present work, we studied the role of Neuregulin (NRG) in the formation and maintenance of the radial glial scaffold in the hippocampal DG of postnatal rats using slice culture. We found that ErbB4 receptors were expressed in vimentin‐positive RGCs in DG of postnatal day 6 (P6) rats. Treatment with NRG and Ab‐3, the inhibitor of ErbB4, revealed that in P6 rats exogenous NRG promoted the proliferation of Vimentin‐positive RGCs in DG. On the other hand, endogenous NRG was found necessary for maintaining the characteristic morphological and immunohistochemical features of these cells. These results indicated that NRG plays a critical role in the formation and maintenance of the radial glial scaffold in the hippocampal DG of postnatal rats. J. Cell. Physiol. 207: 530–539, 2006. © 2006 Wiley‐Liss, Inc.
New polyurethane‐based material for vascular corrosion casting with improved physical and imaging characteristics
Authors: Krucker Thomas , Lang Axel , Meyer Eric P.
Published: February 2006

Vascular corrosion casting has been established as a method to reconstruct the three‐dimensional (3D) structure of blood vessels of organs and tissues. After replacing the blood volume with a low viscosity resin, the surrounding tissue is removed to replicate the vascular architecture, typically using scanning electron microscopy (SEM). To date available casting resins have had significant limitations such as lack of viscosity, leading to insufficient perfusion of smallest capillaries in organs and tissues of smaller species, interaction with surrounding tissue or fragility of resulting casts. We have reported here about a new polyurethane‐based casting resin (PU4ii†) with superior physical and imaging characteristics. Low viscosity, timely polymerization, and minimal shrinking of PU4ii produces high quality casts, including the finest capillaries. These casts are highly elastic while retaining their original structure to facilitate postcasting tissue dissection and pruning of casts. SEM images illustrate the high reproduction quality, including endothelial cell imprints, features that allow one to discern arterial and veinal vessels. For quantitative analysis, casts from PU4ii can be imaged using micro‐computed tomography to produce digital 3D reconstructions. The inherent fluorescence of PU4ii is sufficient to reproduce casts with or without tissue using confocal microscopy (CM). Because of the simplified casting procedure, the high reproducibility and the superior reproduction quality, a combination of vascular corrosion casting using PU4ii with advanced imaging technologies has great potential to support the description of vascular defects and drug effects in disease models using mutant mice. Microsc. Res. Tech. 69:138–147, 2006. © 2006 Wiley‐Liss, Inc.
Microscopy of the Drosophila facet eye: Vademecum for standardized fixation, embedding, and sectioning
Authors: Hess Michael W. , Pfaller Kristian , Hampölz Bernhard , Longato Stefano , Teis David , Flörl Angelika , Gutleben Karin , Huber Lukas A.
Published: February 2006

We describe here a standardized method for histological processing of the Drosophila compound eye. Primary fixation with 2.5% glutaraldehyde, obligatorily supplemented with 0.1% household detergent regularly yielded the best structural preservation, as compared with that of other, more complicated fixation protocols tested. Notably, it proved indispensable not only to cut off the fly's head to facilitate the penetration of the reagents but also to open the chitinous head capsule. For this, we locally pierced the cuticle between the eyes, leaving the head structurally almost intact, a prerequisite for precisely aligning the head for microtomy. We developed a two‐step re‐embedding procedure allowing for exact and reproducible orientation of the fly heads. Thus, highly comparable series of cross sections through a representative number of ommatidia were obtained. The feasibility of our embedding and sectioning approach is finally demonstrated by three‐dimensional reconstructions of the middle segments of the R1, R7, and R8 photoreceptor cells. We present reconstructions from structurally modified ommatidia, as seen after RNAi‐mediated depletion of the endosomal adaptor protein p14, and from normal ommatidia corresponding to the wildtype. Microsc. Res. Tech. 69:93–98, 2006. © 2006 Wiley‐Liss, Inc.
Microscopy under pressure—An optical chamber system for fluorescence microscopic analysis of living cells under high hydrostatic pressure
Authors: Frey Benjamin , Hartmann Markus , Herrmann Martin , Meyer‐Pittroff Roland , Sommer Karl , Bluemelhuber Gerrit
Published: February 2006

High hydrostatic pressure (HHP) becomes more and more interesting for life science research, since it can be employed to inactivate various cells. To directly monitor “cells under pressure,” the development of an optical high‐pressure chamber is required. Therefore, an optical pressure chamber that can be used for up to 300 MPa was constructed. This chamber has already been described as a tool for in situ observation of dynamic changes of microscopic structures in bright field as well as phase contrast. In combination with an inverted microscope, we obtained brilliant microscopic color pictures with an optical resolution more than 0.56 μm. Here, we demonstrate the capabilities of the HHP cell, in combination with epifluorescence microscopy. Using a nonadherent human B‐cell line (Raji, ATCC CCL 86), stained with the fluorescent dyes propidium iodide, Hoechst 33342, or dihexyloxacarbocyanine iodide, we were able to show that the system is suitable to perform fluorescence microscopic analyses, with pressures up to 300 MPa, with viable mammalian cells. Microsc. Res. Tech. 69:65–72, 2006. © 2006 Wiley‐Liss, Inc.