bluuebunny/crossref_metadata_2025 huggingface dataset:
Series of Mn Complexes Based on N‐Centered Ligands and Superoxide – Reactivity in an Anhydrous Medium and SOD‐Like Activity in an Aqueous Medium Correlated to MnII/MnIII Redox Potentials
Authors: Durot Stéphanie , Policar Clotilde , Cisnetti Federico , Lambert François , Renault Jean‐Philippe , Pelosi Giorgio , Blain Guillaume , Korri‐Youssoufi Hafsa , Mahy Jean‐Pierre
Published: August 2005

Two crystal structures are described in this article: (a) the structure of a monomeric MnII complex with the tridentate N‐centered N3 ligand tris[(1‐methyl‐2‐imidazolyl)methyl]amine (TMIMA) ([MnII(TMIMA)2]2+); and (b) the structure of a monomeric MnIII complex with the tridentate N‐centered N2O ligand 2‐{[(1‐methyl‐2‐imidazolyl)methyl]amino}phenolate (PI–)2 ([MnIII(PI)2]+) (5). The latter was isolated both in the MnII and in the MnIII state, although only MnIII crystals were successfully grown. They are part of a series of Mn complexes prepared as SOD mimics, namely [Mn(BMPG)(H2O)]+ (2) {BMPG = N,N‐bis[(6‐methyl‐2‐pyridyl)methyl]glycinate}, [Mn(IPG)(MeOH)]+ (3) {IPG = N‐[(1‐methyl‐2‐imidazolyl)methyl]‐N‐(2‐pyridylmethyl)glycinate}, [Mn(BIG)(H2O)2]+ (4) {BIG = N,N‐bis[(1‐methyl‐2‐imidazolyl)methyl]glycinate}. The reactivity of MnII complexes 1 and 2 in an anhydrous medium is described and compared to that of complexes 3 and 4, the data for which was previously published. The cyclic voltammograms of the whole complex series were recorded in an aqueous medium (collidine buffer). Their SOD‐like activities were estimated by the McCord–Fridovich test (IC50 with 22 μM cytc FeIII: 1.6 ± 0.1 μMol L–1 for 1, 1.2 ± 0.5 μmol L–1 for 2, 3.0 ± 0.2 μmol L–1 for 3, 3.7 ± 0.6 μmol L–1 for 4, 0.8 ± 0.1 μmol L–1 for 5). IC50 values were converted into the corresponding kinetic constant kMcCF values. A linear correlation between Ea and log(kMcCF) was obtained, indicating that in this series the conversion to MnIII is probably the rate‐limiting step. This is of substantial importance for further Mn–SOD mimic design in this series. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
γ‐Alumina as a Support for Catalysts: A Review of Fundamental Aspects
Authors: Trueba Monica , Trasatti Stefano P.
Published: August 2005

The present review discusses the most important aspects to take into consideration to improve the properties of γ‐Al2O3 as a support for catalytic applications. We show that the synthetic route to γ‐Al2O3 is the starting point that determines the micro‐ and macrostructure of the oxide and, consequently, allows control of the support characteristics. The relevance of the adequate structural characterization of the oxide as well as of its surface sorption behavior through the proton‐affinity distributions, are considered. The usefulness of the latter during supported catalyst preparation, for catalytic active sites characterization, and for stability evaluation after calcination are discussed for the Co/γ‐Al2O3 system in particular. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Complexes of the Bicyclic Multifunctional Sulfur‐Nitrogen Ligand F3CCN5S3with Co2+, Zn2+, Cu2+, and Cd
Authors: Knapp Carsten , Mews Rüdiger
Published: August 2005

The ability of the sulfur‐nitrogen‐carbon bicycle F3CCN5S3to act as a donor towards transition metal cations has been investigated. F3CCN5S3forms complexes with [M(SO2)2](AsF6)2[M = Co, Cu, Zn, Cd] in the ratio 2:1 of the composition [M(F3CCN5S3)2(OSO)2(FAsF5)2] [M = Co (1), Zn (3)], [Cu(F3CCN5S3)2(μ‐F)(μ‐F2AsF4)]2(4), and [Cd(F3CCN5S3)(μ‐F3CCN5S3)(η2‐F2AsF4)2]2(5) in liquid sulfur dioxide. In the octahedral Co and Zn complexes F3CCN5S3coordinates as a monodentate ligand through the bridging nitrogen atom N5, which carries the highest negative charge according to theoretical calculations. With Cu2+a dinuclear structure with a central planar, four‐membered Cu2F2ring is formed, which has the shortest Cu···Cu distance of all structurally characterized Cu2F2units. Similar to the Co and Zn complexes, F3CCN5S3acts as a terminal monodentate ligand in the Cu compound. The reaction with the larger and softer Cd2+cation results in a dinuclear complex that contains terminal and bridging F3CCN5S3ligands. The bridging ligands coordinate through N5 and a nitrogen atom neighboring the carbon atom. In addition, a third weak bonding interaction between one fluorine atom of the trifluoromethyl substituent and the Cd2+center is observed. The formation of the different structures and the versatile coordination modes of the F3CCN5S3ligand are discussed. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Detection of Intramolecular Interactions and Molecular Motion in Catenanes by Pulse Voltammetry Methods
Authors: Bilewicz Renata , Korybut‐Daszkiewicz Bohdan , Rogowska Agnieszka , Szydłowska Jadwiga , Wiȩckowska Agnieszka , Domagała Sławomir , Woźniak Krzysztof
Published: August 2005

Pulse voltammetries allowed to demonstrate that interlocking of a dibenzocrown ether with the homo‐ or heterodinuclear bismacrocyclic transition metal complexes leads to increased stability of the mixed‐valence state. Based on the shape of differential pulse curves, the value of comproportionation constants were obtained, showing that the observed effect was larger for the dinickel (d8d8) than for the dicopper (d9d9) catenane. Nonequivalent copper environments in copper catenane were detected by ESR technique. If both of the coordinated ions were identical, the translocation of the crown ether moiety from one site to the other produced the same catenane arrangement. However, intertwining of the dibenzo‐24‐crown‐8 with a heterodinuclear bismacrocyclic complex lead to two possible arrangements, where the π‐electron‐rich benzene rings were located in the vicinity of either the copper or nickel‐complexing macrocycle, depending on the oxidation state of the coordinated ions. Reverse pulse voltammetry with varying initial potentials, Ei, was found to be a convenient tool to follow these subtle changes of electrochemical behavior of redox centers caused by changed interactions inside the molecule.
Forecasting the dollar/euro exchange rate: are international parities useful?
Authors: Sosvilla‐rivero Simón , García Emma
Published: August 2005

In this paper we assess the empirical relevance of an expectations version of purchasing power parity in forecasting the dollar/euro exchange rate. This version is based on the differential of inflation expectations derived from inflation‐indexed bonds for the euro area and the USA.

Using the longest daily data for both the dollar/euro exchange rate and for the inflation expectations, our results suggest that, with few exceptions, our predictors behave significantly better than a random walk in forecasts up to five days, both in terms of prediction errors and in directional forecasts. Copyright © 2005 John Wiley & Sons, Ltd.
Dimensions and deglacial chronology of the Outer Hebrides Ice Cap, northwest Scotland: implications of cosmic ray exposure dating
Authors: Stone John O. , Ballantyne Colin K.
Published: August 2005

Cosmic ray exposure ages of frost‐weathered bedrock from mountain summits in the Outer Hebrides exceed the age of Late Devensian glaciation. Exposure ages of most glacially‐abraded bedrock surfaces at low and intermediate elevations are younger than the age of maximum Late Devensian glaciation. These results confirm that previously mapped periglacial trimlines in the Outer Hebrides define the upper limit of bedrock erosion by Late Devensian ice. They are consistent with the interpretation, based on geomorphological evidence, that the trimlines mark the approximate upper limit of a Late Devensian Outer Hebrides Ice Cap. A postglacial exposure age from the summit of Oreval (662 m) suggests that this mountain was overrun during the last glaciation, indicating thicker ice cover and a lower surface gradient west of the ice‐cap divide than previously inferred. Although bedrock surfaces below the trimlines are strongly ice‐moulded, some show evidence of prior cosmic ray exposure, which we attribute to limited erosion during Late Devensian glaciation. If this interpretation is correct, the youngest apparent ages from these surfaces give the most reliable dates for deglaciation, at ca. 14.5–14 ka. This implies that ice persisted at favourable sites through the warm opening phase of the Windermere Interstade. Comparison with radiocarbon‐dated evidence from offshore cores suggests net ice margin retreat of ∼74 km eastwards across the adjacent shelf in > 2.3 ± 1.0 ka. The dating evidence is consistent with relatively rapid retreat of calving margins to the coast, then slower withdrawal of ice margins to high ground. Copyright © 2005 John Wiley & Sons, Ltd.
The feasibility of monitoring NF‐κB associated cytokines: TNF‐α, IL‐1α, IL‐6, and IL‐8 in whole saliva for the malignant transformation of oral lichen planus
Authors: Rhodus Nelson L. , Cheng Bin , Myers Sandra , Miller Lindsay , Ho Vu , Ondrey Frank
Published: August 2005

Previous investigations have demonstrated that immune activation and chronic inflammation may be one of the causes of oncogenesis. A previous study from our lab has shown significant increases of NF‐κB dependent cytokines, TNF‐α, IL‐1α, IL‐6, and IL‐8 in different oral fluids from oral lichen planus (OLP) patients. The aim of this analysis was to explore the potential of detecting these cytokines in whole unstimulated saliva (WUS) in monitoring the malignant transformation of OLP. Thirteen patients with OLP (with epithelial dysplasia), 13 cases with oral squamous cell carcinoma (OSCC), and 13 age‐sex matched controls were enrolled in the study. The WUS samples were collected and the level of TNF‐α, IL‐1α, IL‐6, and IL‐8 in WUS was determined by ELISA. In moderate and severe dysplasia, the level of each cytokine was significantly higher than in control. In moderate dysplasia, TNF‐α and IL‐1α were significantly increased at a level without difference from OSCC, but IL‐6 and IL‐8 was detected at a concentration significantly lower than OSCC. In severe dysplasia, the level of TNF‐α was also not significantly different from that of OSCC, and the level of IL‐1α, IL‐6, and IL‐8 was still significantly lower than that of OSCC. The level of four cytokines between smokers and non‐smokers in each group did not show a significant difference. These results indicate that the change of NF‐κB dependent cytokines in WUS may in part reflect the malignant transformation of OLP and the analysis of these cytokines and may provide a useful, non‐invasive surrogate endpoint for monitoring malignant transformation as well as the therapeutic response of OLP. This is the first in vivo study utilizing saliva to confirm preclinical data that NF‐κB is upregulated in oral carcinogenesis. © 2005 Wiley‐Liss, Inc.
Quantification of acetogenins in Annona muricata linked to atypical parkinsonism in guadeloupe
Authors: Champy Pierre , Melot Alice , Guérineau Eng Vincent , Gleye Christophe , Fall Djibril , Höglinger Gunter U. , Ruberg Merle , Lannuzel Annie , Laprévote Olivier , Laurens Alain , Hocquemiller Reynald
Published: August 2005

Atypical parkinsonism in Guadeloupe has been associated with the consumption of fruit and infusions or decoctions prepared from leaves of Annona muricata L. (Annonaceae), which contains annonaceous acetogenins, lipophilic inhibitors of complex I of the mitochondrial respiratory chain. We have determined the concentrations of annonacin, the major acetogenin in A. muricata, in extracts of fruit and leaves by matrix‐assisted laser desorption‐ionization mass spectrometry. An average fruit is estimated to contain about 15 mg of annonacin, a can of commercial nectar 36 mg, and a cup of infusion or decoction 140 μg. As an indication of its potential toxicity, an adult who consumes one fruit or can of nectar a day is estimated to ingest over 1 year the amount of annonacin that induced brain lesions in rats receiving purified annonacin by intravenous infusion. © 2005 Movement Disorder Society
Headgroup structure and fatty acid chain length of the acidic phospholipids modulate the interaction of membrane mimetic vesicles with the antimicrobial peptide protegrin‐1
Authors: Jing Weiguo , Prenner Elmar J. , Vogel Hans J. , Waring Alan J. , Lehrer Robert I. , Lohner Karl
Published: August 2005

The interaction of protegrin‐1 (PG‐1), a small β‐sheet antimicrobial peptide with acidic phospholipid model membranes was investigated by differential scanning calorimetry. We found that PG‐1 can distinguish between liposomes of the anionic phospholipids DPPG, DPPS and DPPA, eventhough the headgroups of these phospholipids all have the same net charge and they carry the same hydrocarbon chains. Specifically, PG‐1 had only a minor effect on the thermotropic phase behavior of DPPA liposomes, while it interacted preferentially with the fluid phase of DPPS. Furthermore, PG‐1 could induce a phase separation in DPPG liposomes resulting in the formation of peptide‐rich domains even at low concentrations of the peptide. However, this peptide‐rich domain was not evident when the fatty acyl chains were longer or shorter by two carbon atoms. In addition, PG‐1 can also form peptide‐rich domains in DPPS vesicles but only at high concentrations of the peptide. These results suggest that in addition to an overall negative charge, the structural features of the phospholipid headgroups, lipid packing and thus membrane fluidity will influence the interaction with PG‐1, thereby modulating its biological activity. Copyright © 2005 European Peptide Society and John Wiley & Sons, Ltd.
Titanium vacancies in nonstoichiometric TiO2 single crystal
Authors: Nowotny M. K. , Bak T. , Nowotny J. , Sorrell C. C.
Published: August 2005

The semiconducting properties of single‐crystal TiO2 and their changes during prolonged oxidation at elevated temperatures and under controlled oxygen activity were monitored using measurements of electrical conductivity and thermo‐electric power. Two kinetic regimes were revealed: Regime I – rapid oxidation, associated with the transport of oxygen vacancies, and Regime II – prolonged oxidation, which corresponds to the transport of titanium vacancies. The present data represent the first documented evidence for the formation and transport of titanium vacancies in TiO2. This finding allows the processing of p‐type TiO2 without the incorporation of aliovalent foreign ions. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Rheological Properties of Rice Starch Dispersions in Dimethyl Sulfoxide
Authors: Shon Kwang‐Joon , Lim Seung‐Taik , Yoo Byoungseung
Published: August 2005

The steady and dynamic shear rheological properties of rice starches dispersed in dimethyl sulfoxide (DMSO) solution (90% DMSO‐10% water) were evaluated at various concentrations (7, 8, 9 and 10%, w/w). Rice starch dispersions in DMSO solution at 25°C showed a shear‐thinning flow behavior (n=0.44–0.60) and their consistency index (K) and apparent viscosity (ηa,100) increased with the increase in concentration. The apparent viscosity over the temperature range of 25–70°C obeyed the Arrhenius temperature relationship, indicating that the magnitudes of activation energy (Ea) were in the range of 11.7–12.7 kJ/mol. The Carreau model provided better fit on the shear rate‐apparent viscosity data than the Cross model. Dynamic frequency sweep test showed that both storage modulus (G′) and loss modulus (G′′) of rice starch dispersions increased with the increase in concentration. G′′ showed a higher dependence on frequency (ω) compared to G′ due to the higher G′′ slopes. All rice starch dispersions showed the plateau of G′ at high frequencies. Intrinsic viscosity of rice starch dispersions in DMSO was 104.1 mL/g.
Silber‐Nano‐Cluster in einer plasmapolymeren Releaseschicht. Silver nano cluster in a plasma polymer release layer
Authors: Salz D. , Wagener M.
Published: August 2005

Das Problem mangelhafter Haftung und schlechter chemischer Stabilität von Silber‐Nanoteilchen kann durch eine Einbettung in eine plasmapolymere Matrix gelöst werden. Aufgrund der hohen Permeabilität der Matrix ist ein Silberionenaustausch mit der Oberfläche möglich, so dass diese Schichten eine sehr gute anti‐bakterielle Wirkung aufweisen. Für eine klinische Anwendungsstudie wurden Wundauflagen mit dieser Beschichtung ausgerüstet, die dort ein ausgezeichnetes Resultat lieferten.
Design und Herstellung selektiver Dünnschichtabsorber auf Silberinselbasis. Design and fabrication of selective multilayer absorber based on silver island films
Authors: Heger Petra , Stenzel Olaf , Kaiser Norbert
Published: August 2005

Die Kombination eines Metallinselfilms mit einem dielektrischen Schichtsystem stellt einen neuartigen Ansatz zur Herstellung von wellenlängenselektiven Absorptionsfiltern dar. Fällt Licht auf einen Metallinselfilm, werden Oberflächenplasmonen angeregt, und es kommt zu einer starken Lichtabsorption. Die Plasmonenresonanzfrequenz hängt von der Größe und Form der Inseln ab, die durch die Herstellungsparameter beeinflussbar sind.

Zum Verständnis dieser Systeme wurden als erstes einzelne Silberinselfilme, eingebettet in Al2O3, hergestellt und mittels Spektralphotometer untersucht. Die gewonnenen Spektren erlauben die Bestimmung der optischen Konstanten der Silberinselfilme und zeigen, dass die einzelnen Inselfilme ein maximales Absorptionsvermögen von ca. 40 % besitzen. Bettet man nun diese Silberinselfilme in ein dielektrisches Interferenzschichtsystem ein, erreicht der Absorptionspeak einen Wert von fast 100 %. Dies wird am Beispiel von einem Silberinselfilm in einem Al2O3/TiO2‐Dünnschichtsystem demonstriert.
Case management to improve major depression in primary health care: a systematic review
Authors: GENSICHEN J. , BEYER M. , MUTH C. , GERLACH F. M. , VON KORFF M. , ORMEL J.
Published: August 2005

Background. Deficits in the care of depression lead to poor medication adherence, which increases the risk of an unfavourable outcome for this care. This review evaluates effects on symptoms and medication adherence of case management in primary health care.

Method. A systematic literature search was performed. The quality of the studies was rated according to the Cochrane Effective Practice and Organization of Care Group (EPOC) criteria. To conduct a subgroup analysis interventions were classified as either ‘standard’ or ‘complex’ case management.

Results. Thirteen studies met the inclusion criteria. In a meta-analysis we calculated a standard mean difference/effect size on symptom severity after 6–12 months of −0·40 (95% CI −0·60 to –0·20). Patients in the intervention groups were more likely to achieve remission after 6–12 months [relative risk (RR) 1·39, 95% CI 1·30–1·48]. The relative risk for clinical response was 1·82 (95% CI 1·68–2·05). Patients in intervention groups had better medication adherence than the control group (RR 1·5, 95% CI 1·28–1·86). We found heterogeneous results when assessing effects of different types of intervention.

Conclusions. We conclude that case management improves management of major depression in primary health-care settings.
Authority Orientations and Democratic Attitudes: A Test of the ‘Asian Values’ Hypothesis
Authors: DALTON RUSSELL J. , ONG NHU-NGOC T.
Published: August 2005

The Singaporean patriarch Lee Kuan Yew popularized the argument that ‘Asian values’ derived from Confucian cultural traditions are inconsistent with the development of democracy in East Asia. There is an active scholarly debate over whether the hierarchic and deferential social authority relations of Confucian traditions are incompatible with support for democracy. Drawing upon the newest wave of the World Values Survey, we analyze public opinion in six East Asian nations and four Western democracies. We first assess orientations toward authority, and then link these sentiments to support for democracy. The results contradict the core tenets of the ‘culture is destiny’ argument in the Asian values literature, and offer a more positive view of the prospects for political development in the region.
Reduced hyperpolarization in endothelial cells of rabbit aortic valve following chronic nitroglycerine administration
Authors: Kusama Nobuyoshi , Kajikuri Junko , Yamamoto Tamao , Watanabe Yoshimasa , Suzuki Yoshikatsu , Katsuya Hirotada , Itoh Takeo
Published: August 2005

This study was undertaken to determine whether long‐term in vivo administration of nitroglycerine (NTG) downregulates the hyperpolarization induced by acetylcholine (ACh) in aortic valve endothelial cells (AVECs) of the rabbit and, if so, whether antioxidant agents can normalize this downregulated hyperpolarization.

ACh (0.03–3 μM) induced a hyperpolarization through activations of both apamin‐ and charybdotoxin‐sensitive Ca2+‐activated K+ channels (KCa) in rabbit AVECs. The intermediate‐conductance KCa channel (IKCa) activator 1‐ethyl‐2‐benzimidazolinone (1‐EBIO, 0.3 mM) induced a hyperpolarization of the same magnitude as ACh (3 μM).

The ACh‐induced hyperpolarization was significantly weaker, although the ACh‐induced [Ca2+]i increase was unchanged, in NTG‐treated rabbits (versus NTG‐untreated control rabbits). The hyperpolarization induced by 1‐EBIO was also weaker in NTG‐treated rabbits.

The reduced ACh‐induced hyperpolarization seen in NTG‐treated rabbits was not modified by in vitro application of the superoxide scavengers Mn‐TBAP, tiron or ascorbate, but it was normalized when ascorbate was coadministered with NTG in vivo.

Superoxide production within the endothelial cell (estimated by ethidium fluorescence) was increased in NTG‐treated rabbits and this increased production was normalized by in vivo coadministration of ascorbate with the NTG.

It is suggested that long‐term in vivo administration of NTG downregulates the ACh‐induced hyperpolarization in rabbit AVECs, possibly through chronic actions mediated by superoxide.

British Journal of Pharmacology (2005) 146, 487–497. doi:10.1038/sj.bjp.0706363
Thermal radiation from CN+ and La@CN+
Authors: Hedén M. , Hansen K. , Jonsson F. , Rönnow E. , Gromov A. , Campbell E. E. B. , Taninaka A. , Shinohara H.
Published: August 2005

The radiative cooling of positively charged fullerene and endohedral fullerene fragments of C60, C70, C84, and La@C82 has been measured in a time-of-flight mass spectrometer. The radiative cooling is measured via its influence on the metastable decay. The emissivity extracted from the data is between 4×10−4 and 13×10−4. These values agree fairly well with the emissivity calculated from considering the low-energy tail of the surface plasmon. No major difference is found in the emission behavior of empty and endohedral fullerenes.
Orientational order and finite strain in nematic elastomers
Authors: Fried Eliot , Sellers Shaun
Published: August 2005

Nematic elastomers exhibit large, spontaneous shape changes at the transition from the high-temperature isotropic phase to the low-temperature nematic phase. These finite deformations are studied here in the context of a nonlinear, properly invariant, variational theory that couples the orientational order and elastic deformation. The theory is based on the minimization of a free-energy functional that consists of two contributions: a nematic one due to the interaction of the mesogenic units and an elastic one arising from the stretching of the cross-linked polymer chains. Suitable choices for these two contributions allow for large, reversible, spontaneous shape changes in which the elastic deformation can affect the isotropic-nematic transition temperature. The change in transition temperature as well as the magnitude of the resulting spontaneous deformation is illustrated for various parameter values. The theory includes soft elasticity as a special case but is not restricted to it.
Electrohydrodynamic instability of the interface between two fluids confined in a channel
Authors: Thaokar R. M. , Kumaran V.
Published: August 2005

The stability of the interface between two dielectric fluids confined between parallel plates subjected to a normal electric field in the zero Reynolds number limit is studied analytically using linear and weakly nonlinear analyses, and numerically using a thin-layer approximation for long waves and the boundary element technique for waves with wavelength comparable to the fluid thickness. Both the perfect dielectric and leaky dielectric models are studied. The perfect dielectric model is applicable for nonconducting fluids, whereas the leaky dielectric fluid model is applicable to fluids where the time scale for charge relaxation, (ϵϵ0∕σ), is small compared to the fluid time scale (μR∕Γ), where ϵ0 is the dielectric permittivity of the free space, ϵ and σ are the dielectric constant and the conductivity of the fluid, μ and Γ are the fluid viscosity and surface tension, and R is the characteristic length scale. The linear stability analysis shows that the interface becomes unstable when the applied potential exceeds a critical value, and the critical potential depends on the ratio of dielectric constants, electrical conductivities, thicknesses of the two fluids, and surface tension. The critical potential is found to be lower for leaky dielectrics than for perfect dielectrics. The weakly nonlinear analysis shows that the bifurcation is supercritical in a small range of ratio of dielectric constants when the wavelength is comparable to the film thickness, and subcritical for all other values of dielectric constant ratio in the long-wave limit. The thin-film and boundary integral calculations are in agreement with the weakly nonlinear analysis, and the boundary integral calculation indicates the presence of a secondary subcritical bifurcation at a potential slightly larger than the critical potential when the instability is supercritical. When a mean shear flow is applied to the fluids, the critical potential for the instability increases, and the flow tends to alter the nature of the bifurcation from subcritical to supercritical.
Structure-dependent microwave dielectric properties of (1−x)La(Mg1∕2Ti1∕2)O3–xLa2∕3TiO3 ceramics
Authors: Salak Andrei N. , Khalyavin Dmitry D. , Mantas Pedro Q. , Senos Ana M. R. , Ferreira Victor M.
Published: August 2005

Structure and dielectric characterizations were performed on the (1−x)La(Mg1∕2Ti1∕2)O3–xLa2∕3TiO3 perovskite ceramics with the actual composition 0⩽x⩽0.52. The sequence of structure transformations was detected as x is increased: P21∕n(0⩽x<0.3)→Pnma(0.3⩽x<0.37)→Imma(0.37⩽x<0.4)→I2∕a(0.4⩽x⩽0.49)→R3¯c(0.49<x⩽0.52). The structure evolution from the tilt configuration a−b+a− to a−a−a− is considered in terms of competing the repulsive energy and the Madelung energy. Relative permittivity of the ceramics was measured as a function of temperature and La2∕3TiO3 content. The temperature coefficient of the resonant frequency was found to pass zero value at the narrow compositional range between x=0.49 and 0.52, where the discontinuous I2∕a→R3¯c crossover occurs. The temperature and compositional variations of these fundamental microwave dielectric parameters are discussed in respect to the type of the phase transitions (continuous/discontinuous) between the structures.
Focused electron-beam-induced etching of silicon dioxide
Authors: Randolph S. J. , Fowlkes J. D. , Rack P. D.
Published: August 2005

Focused electron-beam (FEB)-induced etching of silicon dioxide with xenon difluoride has been investigated as a selective nanoscale etching technique. In order to gain an understanding of the parameters that control etch rate and etch efficiency, the effects of beam current, beam energy, and scan rate conditions on the FEB process were examined. High etch rates were obtained for low beam energy, high beam current, and high scan rates. Experimental results also indicated that the FEB etch process is governed by the electron-stimulated desorption of oxygen from the SiO2 matrix, and subsequently rate limited by XeF2 availability. Based on experimental evidence and existing literature, a simple, two-step model was introduced to qualitatively describe the etch mechanism. The model involves a cyclical process, which is initiated by the reduction of a surface layer of SiO2 to elemental silicon. The exposed silicon surface is then removed by a chemical-mediated etch reaction.
The influence of the insulator surface properties on the hydrogen response of field-effect gas sensors
Authors: Eriksson Mats , Salomonsson Anette , Lundström Ingemar , Briand Danick , Åbom A. Elisabeth
Published: August 2005

The hydrogen response of gas-sensitive field-effect devices is mainly due to trapping of atomic hydrogen on the insulator side of the metal-insulator interface of the metal-insulator-semiconductor (MIS) structure. Therefore an influence of the choice of insulator on the hydrogen response properties is expected. We have investigated this influence by producing MIS capacitors with four different insulators; SiO2, Al2O3, Si3N4, and Ta2O5. The results show that the choice of insulator influences the detection limit, the saturation concentration, and the saturation response. Furthermore, there is a strong correlation between the observed saturation response and the oxygen concentration of the insulator surface, as measured by Auger electron spectroscopy, which indicates that the trapping of hydrogen at the interface occurs at the oxygen atoms of the insulator surface. Finally, if the metal film is porous a catalytic oxidation of the insulator surface appears to be facilitated, which can increase the hydrogen response.
Size and emission wavelength control of InAs∕InP quantum wires
Authors: Fuster David , González Luisa , González Yolanda , González María Ujué , Martínez-Pastor Juan
Published: August 2005

For a certain heteroepitaxial system, the optical properties of self-assembled nanostructures basically depend on their size. In this work, we have studied different ways to modify the height of InAs∕InP quantum wires (QWrs) in order to change the photoluminescence emission wavelength. One procedure consists of changing the QWr size by varying the amount of InAs deposited. The other two methods explored rely on the control of As∕P exchange process, in one case during growth of InAs on InP for QWr formation and in the other case during growth of InP on InAs for QWr capping. The combination of the three approaches provides a fine tuning of QWr emission wavelength between 1.2 and 1.9μm at room temperature.
Three-dimensional organization of rare-earth atoms at grain boundaries in silicon nitride
Authors: Winkelman Graham B. , Dwyer Christian , Hudson Toby S. , Nguyen-Manh Duc , Döblinger Markus , Satet Raphaelle L. , Hoffmann Michael J. , Cockayne David J. H.
Published: August 2005

Used in the preparation of Si3N4 components, rare-earth elements promote the growth of needlelike grains essential to elevated toughness; evidently, La is significantly more effective than Lu. To explore this difference, we determine the three-dimensional organization of rare-earth atoms in the amorphous phase near prismatic interfaces in La- and Lu-containing Si3N4 using aberration-corrected high-angle annular dark-field scanning transmission electron microscopy and image processing. Evidence is presented for substantial atomic structure in notionally amorphous volumes. While the atomic arrangement in the amorphous phase conforms to the periodicity of the terminating crystal plane in both cases, the attachment sites are very different.
RETRACTED: B7-DC cross-linking restores antigen uptake and augments antigen-presenting cell function by matured dendritic cells
Authors: Radhakrishnan Suresh , Celis Esteban , Pease Larry R.
Published: August 2005

Dendritic cells (DCs) are classified in two states: immature DCs (iDCs), which perform sentinel functions, sampling for antigen and danger signals, and mature DCs (mDCs), which exhibit enhanced antigen-presenting functions but are no longer capable of acquiring antigen. We now describe DCs with a different activation phenotype: cells having the strong antigen-presenting functions of mDCs and the antigen-acquiring functions of iDCs. We have described an antibody that binds the costimulatory molecule B7-DC and activates DCs. The resulting phenotype is distinct from iDCs or mDCs matured by using Toll-like receptor (TLR) agonists. Ability to take up antigen increases, while expression of B71/2 costimulatory and MHC molecules remains unchanged. DCs matured with TLR agonists and then superactivated through B7-DC exhibit a previously unrecognized phenotype. These DCs recover the ability to take up antigen, which is normally lost after treatment with TLR-3 and TLR-9 agonists, yet retain the high expression of costimulatory and MHC molecules and strong antigen-presenting functions of mDCs. Immunization using TLR agonists and B7-DC XAb (cross-linking antibody) together as adjuvant resulted in substantially increased cytolytic T cell responses, particularly when minimal peptide antigens were used. By stimulating DCs with two distinct activation signals, a previously unrecognized phenotype exhibiting augmented antigen-presenting functions was obtained.
Directed evolution of protein switches and their application to the creation of ligand-binding proteins
Authors: Guntas Gurkan , Mansell Thomas J. , Kim Jin Ryoun , Ostermeier Marc
Published: August 2005

We describe an iterative approach for creating protein switches involving the
in vitro
recombination of two nonhomologous genes. We demonstrate this approach by recombining the genes coding for TEM1 β-lactamase (BLA) and the
Escherichia coli
maltose binding protein (MBP) to create a family of MBP–BLA hybrids in which maltose is a positive or negative effector of β-lactam hydrolysis. Some of these MBP–BLA switches were effectively “on–off” in nature, with maltose altering catalytic activity by as much as 600-fold. The ability of these switches to confer an effector-dependent growth/no growth phenotype to
E. coli
cells was exploited to rapidly identify, from a library of 4 × 10
6
variants, MBP–BLA switch variants that respond to sucrose as the effector. The transplantation of these mutations into wild-type MBP converted MBP into a “sucrose-binding protein,” illustrating the switches potential as a tool to rapidly identify ligand-binding proteins.
Synergistic recognition of an epigenetic DNA element by Pleiohomeotic and a Polycomb core complex
Authors: Mohd-Sarip Adone , Cléard Fabienne , Mishra Rakesh K. , Karch François , Verrijzer C. Peter
Published: August 2005

Polycomb response elements (PREs) are cis-acting DNA elements that mediate epigenetic gene silencing by Polycomb group (PcG) proteins. Here, we report that Pleiohomeotic (PHO) and a multiprotein Polycomb core complex (PCC) bind highly cooperatively to PREs. We identified a conserved sequence motif, named PCC-binding element (PBE), which is required for PcG silencing in vivo. PHO sites and PBEs function as an integrated DNA platform for the synergistic assembly of a repressive PHO/PCC complex. We termed this nucleoprotein complex silenceosome to reflect that the molecular principles underpinning its assemblage are surprisingly similar to those that make an enhanceosome.
Genome sequence of Blochmannia pennsylvanicus indicates parallel evolutionary trends among bacterial mutualists of insects
Authors: Degnan Patrick H. , Lazarus Adam B. , Wernegreen Jennifer J.
Published: August 2005

The distinct lifestyle of obligately intracellular bacteria can alter fundamental forces that drive and constrain genome change. In this study, sequencing the 792-kb genome of Blochmannia pennsylvanicus, an obligate endosymbiont of Camponotus pennsylvanicus, enabled us to trace evolutionary changes that occurred in the context of a bacterial–ant association. Comparison to the genome of Blochmannia floridanus reveals differential loss of genes involved in cofactor biosynthesis, the composition and structure of the cell wall and membrane, gene regulation, and DNA replication. However, the two Blochmannia species show complete conservation in the order and strand orientation of shared genes. This finding of extreme stasis in genome architecture, also reported previously for the aphid endosymbiont Buchnera, suggests that genome stability characterizes long-term bacterial mutualists of insects and constrains their evolutionary potential. Genome-wide analyses of protein divergences reveal 10- to 50-fold faster amino acid substitution rates in Blochmannia compared to related bacteria. Despite these varying features of genome evolution, a striking correlation in the relative divergences of proteins indicates parallel functional constraints on gene functions across ecologically distinct bacterial groups. Furthermore, the increased rates of amino acid substitution and gene loss in Blochmannia have occurred in a lineage-specific fashion, which may reflect life history differences of their ant hosts.
Long-lasting modifications of saccadic eye movements following adaptation induced in the double-step target paradigm
Authors: Alahyane Nadia , Pélisson Denis
Published: August 2005

The adaptation of saccadic eye movements to environmental changes occurring
throughout life is a good model of motor learning and motor memory. Numerous
studies have analyzed the behavioral properties and neural substrate of
oculomotor learning in short-term saccadic adaptation protocols, but to our
knowledge, none have tested the persistence of the oculomotor memory. In the
present study, the double-step target protocol was used in five human subjects
to adaptively decrease the amplitude of reactive saccades triggered by a
horizontally-stepping visual target. We tested the amplitude of visually
guided saccades just before and at different times (up to 19 days) after the
adaptation session. The results revealed that immediately after the adaptation
session, saccade amplitude was significantly reduced by 22% on average.
Although progressively recovering over days, this change in saccade gain was
still statistically significant on days 1 and 5, with an average retention
rate of 36% and 19%, respectively. On day 11, saccade amplitude no longer
differed from the pre-adaptation value. Adaptation was more effective and more
resistant to recovery for leftward saccades than for rightward ones. Lastly,
modifications of saccade gain related to adaptation were accompanied by a
decrease of both saccade duration and peak velocity. A control experiment
indicated that all these findings were specifically related to the adaptation
protocol, and further revealed that no change in the main sequence
relationships could be specifically related to adaptation. We conclude that in
humans, the modifications of saccade amplitude that quickly develop during a
double-step target adaptation protocol can remain in memory for a much longer
period of time, reflecting enduring plastic changes in the brain.
Day‐of‐the‐Week Effect in High Moments
Authors: Galai Dan , Kedar‐Levy Haim
Published: August 2005

Evidence from equity markets worldwide indicates that the Day‐of‐the‐Week anomaly appears to fade from the first moment of the distribution of daily returns. We report highly significant pair‐wise weekend effects in high moments when comparing the first and last trading days of the week. The second moment alone appears to distinguish the return distribution of the first trading day from all others. A probable explanation of the phenomena appears to be information dissemination: corporate announcements released after closing of the last trading day of the week spill‐over to the opening of the first trading day, increasing its variability and carrying the closing sign.
Inhibition of the 53BP2S‐mediated apoptosis by nuclear factor κB and Bcl‐2 family proteins
Authors: Takahashi Naoko , Kobayashi Shinya , Kajino Shinichi , Imai Kenichi , Tomoda Keisuke , Shimizu Shigeomi , Okamoto Takashi
Published: August 2005

The p53 binding protein 2 (53BP2) has been identified independently as the interacting protein to p53, Bcl‐2, and p65 subunit of nuclear factor κB (NF‐κB). It was demonstrated that over‐expression of 53BP2 (renamed as 53BP2S) induces apoptotic cell death. In this study we explored the effect of NF‐κB activation elicited by a physiological NF‐κB inducer, interleukin‐1β (IL‐1β), and anti‐apoptotic Bcl‐2 family proteins on the 53BP2S‐mediated apoptosis. We found that both NF‐κB activation and Bcl‐2 family proteins could prevent the 53BP2S‐mediated depression of mitochondrial transmembrane potential, activation of caspase‐9, cleavage of poly ADP ribose polymerase (PARP), and cell death. These observations suggested that 53BP2S/Bbp and its directly or indirectly interacting proteins might play crucial roles in the regulation of apoptosis and contribute to carcinogenesis. It is also suggested that 53BP2S/Bbp induces apoptosis through the mitochondrial death pathway presumably by counteracting the actions of anti‐apoptotic Bcl‐2 family proteins. The regulatory network of the 53BP2S‐mediated apoptosis cascade including its interacting proteins is discussed.
De novo synthesis and accumulation of apoplastic proteins in leaves of heavy metal‐exposed barley seedlings
Authors: BLINDA A. , KOCH B. , RAMANJULU S. , DIETZ K.‐.J.
Published: August 2005

The leaf apoplast is a site of preferential accumulation of heavy metals in the shoot when barley seedlings are grown in the presence of cadmium, nickel or zinc in hydroponic medium. It was shown recently that apoplastic protein content increased concomitantly in plants grown in the presence of high Zn (Brune et al. 1994, Journal Experimental Botany 45, 1189). Here it is demonstrated that apoplastic proteins increase to an even greater extent in Ni‐treated plants, and that the response is intermediate for Cd‐treated plants. The paper focuses on possible causes for the increase in apoplastic proteins. (1) Synthesis of cell wall proteins was studied by in vivo pulse labelling of leaf proteins with 35S methionine followed by extraction of extracellular polypeptides. Depending on growth conditions and leaf age, 1–6% of the protein synthesized de novo in the leaf was allocated to the extractable protein fraction of the leaf apoplast. Under control conditions, labelling reached its maximum after 2 h; labelling continued to rise in Ni‐treated plants, where the maximum level of final labelling was reached only after several hours. Labelling decreased with leaf age and increased proportionally with Ni concentration in the nutrient solution. (2) Autolysis experiments on extracted apoplastic proteins and in situ digestion of infiltrated ovalbumin revealed a low proteolytic activity in the apoplast which was not altered in heavy metal‐treated leaves. (3) Following a sudden application of Ni to the growth medium, protein content and peroxidase activity increased with a 48 h delay and approached the level obtained for continuously Ni‐treated plants, even in previously fully expanded leaf tissue. It is concluded that altered cell wall structure is probably not involved in increasing the extraction yield of apoplastic proteins. (4) The increase in extractable apoplastic proteins was also not due to inhibited ionical or covalent immobilization of proteins in the cell wall matrix of heavy metal‐challenged plants. (5) Northern blotting revealed heavy metalinduced upregulation of mRNA levels of selected apoplastic proteins. Taken together, the data provide evidence for a transcriptional or translational level of regulation as the main cause of the strong response of apoplastic proteins to heavy metal stress.
The clinical relevance of sensitization to pollen‐related fruits and vegetables in unselected pollen‐sensitized adults
Authors: Osterballe M. , Hansen T. K. , Mortz C. G. , Bindslev‐Jensen C.
Published: August 2005

Background:  Previous studies have described cross‐reactivity between fresh fruits, vegetables and pollen. However, no data demonstrates the clinical relevance of sensitization to pollen‐related fruits and vegetables in unselected pollen‐sensitized adults with and without symptoms in the pollen season.

Objective:  The aim of this study was to estimate the clinical relevance of sensitization to pollen‐related fruits and vegetables in unselected pollen‐sensitized adults and to examine the diagnostic value of skin‐prick test (SPT), histamine release and specific IgE compared with the outcome of oral challenge.

Methods:  In total, 936 unselected adults (female : male 479 : 457, median age 33.7 years) were examined for pollen sensitization and clinical cross‐reactivity with pollen‐related fruits and vegetables by questionnaire, SPT, histamine release, specific IgE and oral challenge.

Results:  The prevalence of pollen sensitization was 23.8% (n = 223). The probability of a clinical reaction to pollen‐related foods in the respective pollen‐sensitized groups was: 24% (birch), 4% (grass), 10% (mugwort), 35% (birch + grass), 8% (grass + mugwort) and 52% (birch + grass + mugwort). The odds ratio of a clinical reaction to pollen‐related fruits and vegetables in symptomatic pollen‐sensitized adults was as high as four times (birch + grass) the odds ratio of a clinical reaction in asymptomatic pollen‐sensitized adults.

Conclusion:  This study not only demonstrates a high prevalence of clinical reactions to fruits and vegetables in pollen‐sensitized adults, but also a discrepancy between the prevalence of sensitization to fruits and vegetables and the clinical relevance in different pollen‐sensitized groups with symptoms in the pollen season as a significant factor.
Idiopathic Epilepsies with a Monogenic Mode of Inheritance
Authors: Steinlein Ortrud K.
Published: August 2005

Idiopathic epilepsies account for ∼40% of all epileptic diseases. For a long time, it has been known that genetic factors play a major role in the etiology of these diseases. Although oligogenic or polygenic inheritance is suspected in most of the common syndromes, a few rare idiopathic epilepsies are single‐gene disorders. They offer a chance to identify candidate genes that also may be involved in epilepsies with complex inheritance. In recent years, major progress has been made regarding the analysis of genetic factors in idiopathic epilepsy. For the first time, gene defects could be linked to two idiopathic epilepsies. Mutations in the CHRNA4 gene, which codes for the α4 subunit of the neuronal nicotinic acetylcholine receptor, lead to autosomal dominant nocturnal frontal lobe epilepsy, a rare idiopathic partial epilepsy syndrome. Two highly homologous voltage‐gated potassium channels, KCNQ2 and KCNQ3, were found to be mutated in benign familial neonatal convulsions.
Mouse Models of Spike‐Wave Epilepsy
Authors: Barclay Jane , Rees Michele
Published: August 2005

The mouse is a well‐established model for human genetic disorders. An increasing number of single‐gene human diseases are being elucidated through the use of mouse models. Recently genes for three of the six well‐characterised single‐locus models for human spike‐wave epilepsy have been isolated and published. The tottering mouse has been shown to be due to mutations in the gene encoding the high voltage‐activated α1A calcium channel subunit. The lethargic mouse has been shown to be due to mutations in the gene encoding another calcium channel subunit, β4. The slow‐wave epilepsy mouse phenotype is the result of loss of function of the ubiquitous sodium hydrogen exchanger NHEI. These genes and the pathways they are involved in are now candidates for human spike‐wave epilepsy. The six mouse models and those genes underlying the spike‐wave phenotype are discussed in conjunction with how these mutations were discovered and how they may give rise to the seizure phenotypes. Several nonepilepsy human neurologic disorders have been shown to be allelic with the tottering mouse. The question this raises as to the validity of these models for human spike‐wave epilepsy is considered. Finally, the effect these discoveries will have on the understanding and treatment of human spike‐wave epilepsy are discussed.