bluuebunny/crossref_metadata_2025 huggingface dataset:
Calculation of excitation energies of open-shell molecules with spatially degenerate ground states. I. Transformed reference via an intermediate configuration Kohn-Sham density-functional theory and applications to d1 and d2 systems with octahedral and tetrahedral symmetries
Authors: Seth Michael , Ziegler Tom
Published: October 2005

A method for calculating the UV-vis spectra of molecules with spatially degenerate ground states using time-dependent density-functional theory (TDDFT) is proposed. The new transformed reference via an intermediate configuration Kohn-Sham TDDFT (TRICKS-TDDFT) method avoids the difficulties caused by the multireference nature of spatially degenerate states by rather than utilizing the ground state instead taking a nondegenerate excited state with desirable properties as the reference for the TDDFT calculation. The scope and practical application of the method are discussed. Like all open-shell TDDFT calculations this method at times suffers from the inability to produce transitions to states that are eigenfunctions of the total spin operator. A technique for alleviating this difficulty to some extent is proposed. The applicability and accuracy of the TRICKS-TDDFT method is demonstrated through example calculations of several d1 and d2 transition metal complexes with tetrahedral and octahedral symmetries. For the most part, the results of these calculations are similar in quality to to those obtained from standard TDDFT calculations.
Parallel tempering simulations of the 13-center Lennard-Jones dipole-dipole cluster (μD=→0.5a.u.)
Authors: Pav Dawn M. , Curotto E.
Published: October 2005

We investigate the thermodynamic behavior of the thirteen center uniform Lennard-Jones dipole-dipole cluster [(LJDD)13] for a wide range of dipole moment strengths. We find a relatively wide range of potential parameters where solid-solid coexistence manifests itself. Using structural characterization methods we determine the shape of the few isomers that contribute to the solid-solid coexistence region. The thermal distributions of the size of the net dipole moment are broad even at the coldest temperatures of the simulation where the (LJDD)13 cluster is solid.
MMM1D: A method for calculating electrostatic interactions in one-dimensional periodic geometries
Authors: Arnold Axel , Holm Christian
Published: October 2005

We present a new method to accurately calculate the electrostatic energy and forces on charges in a system with periodic boundary conditions in one of three spatial dimensions. We transform the Coulomb sum via a convergence factor into a series of fast decaying functions similar to the Lekner method. Rigorous error bounds for the energies and the forces are derived and numerically verified. The method has a computational complexity of O(N2), but is faster and easier to use than previously reported methods.
Lateral organic light-emitting diode with field-effect transistor characteristics
Authors: Oyamada Takahito , Uchiuzou Hiroyuki , Akiyama Seiji , Oku Yoshiaki , Shimoji Noriyuki , Matsushige Kazumi , Sasabe Hiroyuki , Adachi Chihaya
Published: October 2005

We succeeded in observing bright electroluminescence (EL) from 1wt%-rubrene doped tetraphenylpyrene (TPPy) as an active layer in a lateral organic light-emitting diode structure that allowed field-effect transistor operation. This device configuration provides an organic light-emitting diode structure where the anode (source) and cathode (drain) electrodes are laterally arranged, providing us a chance to control the EL intensity by changing the gate bias. We demonstrated that TPPy provides compatible transistor and EL characteristics. Further, not only rubrene doping into the TPPy host but also adjusting the source-drain channel length significantly improved the EL characteristics. We observed a maximum EL quantum efficiency (ηext) of ∼0.5% with a Cr∕Au source (S)-drain (D) electrode and a slightly higher ηext of ∼0.8% with S-D electrodes of MgAu∕Au, Al∕Au, Cr∕YAu∕Au, and MgAl∕Au multilayers, aiming for simultaneous hole and electron injection.
Stress evolution during growth in direct-current-sputtered zinc oxide films at various oxygen flows
Authors: Drese Robert J. , Wuttig Matthias
Published: October 2005

The evolution of stress during the growth of zinc and zinc oxide films deposited from a metallic target using direct-current magnetron sputtering has been analyzed in situ. For this purpose a two-beam wafer curvature setup attached to the sputter chamber was employed. The oxygen flow during the deposition was varied over a wide range to obtain films with stoichiometries between metallic zinc and fully stoichiometric zinc oxide. In good agreement with results from Hinze and Ellmer [J. Appl. Phys. 88, 2443 (2000)] on radio-frequency-sputtered zinc oxide from an oxidic target, the oxidic films analyzed in this work possess high levels of compressive stress. These stresses arise in the early stages of film growth and are constant above a certain film thickness. The level of stress in the films is highly dependent on the deposition pressure, which indicates that the stress originates from bombardment with energetic particles, namely, oxygen ions. In contrast to the oxidic films, metallic zinc films exhibit only very low levels of stress. The stress evolution is similar to that of evaporated high-mobility films and does not change upon variation of deposition pressure.
Highly sensitive thin-film organic phototransistors: Effect of wavelength of light source on device performance
Authors: Noh Yong-Young , Kim Dong-Yu , Yase Kiyoshi
Published: October 2005

Organic phototransistors (OPTs) were fabricated from pentacene and copper phthalocyanine (CuPC) based on the geometry of organic field-effect transistors (OFETs); and the effect of the wavelength of the incident light source on their performance was examined. High performance OFETs with pentacene and CuPC were fabricated and the characteristics of the OPTs were examined under UV and visible-light irradiations with top illumination. The CuPC and pentacene OPTs show a high responsivities of 0.5–2 and 10–50A∕W and maximum IPh∕IDark of 3000 and 1.3×105, respectively, under 365nm UV light. However, under visible light, at a wavelength of 650nm, the pentacene OPTs had 100 times less responsivity, 0.15–0.45A∕W, and a IPh∕IDark of 1000, even though an absorption coefficient three times larger was observed at this wavelength than at 365nm. A strong correlation was found between the performance of the OPTs and the incident photon to current conversion efficiency spectra of an organic semiconductor. The strong dependence on the wavelength of incident light of the performance of the prepared OPTs can be explained by an internal filter effect in which light with a large absorption coefficient is filtered at the top surface and through the bulk of the film when light is directed onto the opposite side of the OFET gate electrode. Thus, light cannot efficiently contribute to the generation of charge carriers in the channel regions that were formed in the first two molecular layers adjacent to the dielectric interface. Consequently, the most efficient OPTs were produced when the following conditions of incident light were satisfied: The photon energies (or frequencies) should be (i) larger than the band gap and (ii) have a relatively small absorption coefficient, since the light can penetrate down to the channel layer more efficiently when it is near the dielectric interface without any loss in absorption through the film.
Dopant local bonding and electrical activity near Si(001)-oxide interfaces
Authors: Zhou Zhiyong , Steigerwald Michael L. , Friesner Richard A. , Brus Louis , Hybertsen Mark S.
Published: October 2005

Electronic structure calculations based on a density-functional approach have been performed for P, As, B, and Al subsitutional dopants near the Si(001)-oxide interface. The structures are geometrically optimized for each charge state. P and As geometries show a strong distortion when neutral, and regain tetrahedral local bonding when ionized. This geometry change creates an activation barrier for the release of the electron. Distorted neutral dopants may react with hydrogen during the forming gas interface passivation. In contrast, B and Al show tetrahedral bonding for all charge states. All four neutral dopants show substantial energy gain upon formation of dimer complexes near the interface. Neutral B is significantly more stable when bonded to two O atoms at the interface, while neutral P is more stable bonded to four Si atoms adjacent to the interface.
Formation and direct writing of color centers in LiF using a laser-induced extreme ultraviolet plasma in combination with a Schwarzschild objective
Authors: Barkusky Frank , Peth Christian , Mann Klaus , Feigl Torsten , Kaiser Norbert
Published: October 2005

In order to generate high-energy densities of 13.5nm radiation, an extreme ultraviolet (EUV) Schwarzschild mirror objective with a numerical aperture of 0.44 and a demagnification of 10 was developed and adapted to a compact laser-based EUV source. The annular spherical mirror substrates were coated with Mo∕Si multilayer systems. With a single mirror reflectance of more than 65% the total transmittance of the Schwarzschild objective exceeds 40% at 13.5nm. From the properties of the EUV source (pulse energy 3mJ at 13.5nm and plasma diameter approximately 300μm), energy densities of 73mJ∕cm2 at a pulse length of 6ns can be estimated in the image plane of the objective. As a first application, the formation of color centers in lithium fluoride crystals by EUV radiation was investigated. F2, F3, and F3+ color centers could be identified by absorption spectroscopy. The formation dynamics was studied as a function of the EUV dose. By imaging of a pinhole positioned behind the plasma, an EUV spot of 5μm diameter was generated, which accomplishes direct writing of color centers with micrometer resolution.
Ion-acoustic solitary excitations in a two-electron-temperature plasma with adiabatic warm ions: Oblique modulation
Authors: Esfandyari-Kalejahi A. , Asgari H.
Published: October 2005

Theoretical and numerical studies are given for the amplitude modulation of ion-acoustic waves (IAWs) in a plasma consisting of two types of electrons (cold and hot) and adiabatic warm ions. Perturbations oblique to the carrier IAW propagation direction have been investigated. The stability analysis, based on a nonlinear Schrödinger equation reveals that the IAW may become unstable; the stability criteria depend on the angle θ between the modulation and propagation directions. Different types of localized IA excitations are shown to exist. The inclusion of adiabatic finite ion temperature, as compared to the cold ion model, allows for bright type solitary excitations, yet generally favors IAW stability and dark and gray envelope solitons.
Current perpendicular to the plane spin valves utilizing ultrastrong Ir-coupled antiparallel pinned layers for thick reference layer stabilization and high magnetoresistance
Authors: Maat S. , Carey M. J. , Katine J. A. , Childress J. R.
Published: October 2005

The magnetoresistance of current perpendicular to the plane spin-valve sensors with antiparallel coupled pinned layers utilizing Ir as an AP coupling layer was measured as a function of reference layer thickness. Ir-coupled antiparallel pinned structures exhibit extremely high coupling energies in excess of 3ergs∕cm2, allowing for an increase of the thicknesses of both the pinned layer and reference layer to more than 100 Å while maintaining both high saturation fields and a moment-balanced antiparallel pinned structure desirable for stable read sensors. The spin valves were patterned into pillars with diameters ranging from 50 to 200 nm by using a combination of electron beam lithography and ion milling. The magnetoresistance increases from 2.2% to 4.0% by increasing the reference layer thickness from 30 to 110 Å, which is in agreement with the Valet-Fert model in the long spin-diffusion length limit.
Magnetoresistance flipping of Fe∕Ru multilayers prepared by electron-beam evaporation
Authors: Geng K. W. , Gu Y. , Xu D. , Song C. , Pan F.
Published: October 2005

Fe ∕ Ru multilayers were prepared by electron-beam evaporation. The magnetoresistance (MR) properties of the multilayer switched the MR sign with the Fe and Ru layer thickness. When the thickness of magnetic Fe layers was fixed at 1.2 nm, the MR effects of the multilayer transformed from a negative to a positive one, with the thickness of nonmagnetic Ru layer changed from 1.2 to 5.0 nm. While when the thickness of nonmagnetic Ru layers was fixed, the transformation of the MR effect is inversed, i.e., transformed from a positive to a negative one with the thickness of the magnetic Fe layer increased. The origin of the MR variation is analyzed. The inverse giant magnetoresistance is related to the Fe∕Ru interface layer, in which the scattering spin asymmetry is less than 1. The MR dependence on the Fe and Ru layer thickness reveals the competition between two mechanisms of normal MR and inverse MR
Cu and CdCl2 influence on defects detected in CdTe solar cells with admittance spectroscopy
Authors: Seymour Fred H. , Kaydanov Victor , Ohno Tim R. , Albin David
Published: October 2005

Admittance spectroscopy was used with a custom built temperature stage to study deep level defects in four polycrystalline thin-film CdTe solar cells that had postdeposition back contact treatments with and without Cu and CdCl2. One hole trap signature with activation energy Ea≈0.13eV was detected in all four cells and was attributed to a combination of VCd− and related complexes. A second hole trap with Ea≈0.30eV and detected only in Cu-treated cells was attributed to CuCd−. A third hole trap with Ea≈0.47eV was detected only in non-Cu-treated cells. The relationships and relative concentrations between these distinct trap levels are discussed.
Vortex rings in pure water under static external electric field
Authors: Chiragwandi Z. G. , Nur O. , Willander M. , Panas I.
Published: October 2005

The reproducible development of vortex rings in pure water under the action of a static external electric field is demonstrated. The phenomenon results from the electrochemical decomposition of water. Given the low conductivity of water in the absence of electrolyte, the field-driven buildup of hydroxide ions at the anode becomes essential to the proton release, which in turn is the result of the molecular O2(g) evolution. Water recombination processes, which have protons flowing in a hydroxide background, as a key ingredient produce the phenomenon.
Composition profiles of InAs–GaAs quantum dots determined by medium-energy ion scattering
Authors: Quinn P. D. , Wilson N. R. , Hatfield S. A. , McConville C. F. , Bell G. R. , Noakes T. C. Q. , Bailey P. , Al-Harthi S. , Gard F.
Published: October 2005

The composition profile along the [001] growth direction of low-growth-rate InAs–GaAs quantum dots (QDs) has been determined using medium-energy ion scattering (MEIS). A linear profile of In concentration from 100% In at the top of the QDs to 20% at their base provides the best fit to MEIS energy spectra.
Microstructural study of an oscillatory formation reaction in nanostructured reactive multilayer foils
Authors: Trenkle J. C. , Wang J. , Weihs T. P. , Hufnagel T. C.
Published: October 2005

We report evidence of an oscillatory formation reaction in nanostructured Zr∕Al∕(CuNi) reactive multilayer foils. The oscillations create periodic ripples on the surface of the foil as well as periodic variations in the length scale of the microstructure of the reacted foil. We describe the nature of the resulting microstructure, and relate this to superadiabatic temperature oscillations at the reaction front. We also examine the effect of ambient temperature on the magnitude and period of the oscillations, and compare the results to numerical predictions and to experimental data for other reactive systems.
First demonstration of a staged all-optical laser wakefield acceleration
Authors: Kaganovich D. , Ting A. , Gordon D. F. , Hubbard R. F. , Jones T. G. , Zigler A. , Sprangle P.
Published: October 2005

A proof-of-principle experiment on staged all-optical laser wakefield acceleration was performed at the Naval Research Laboratory. Electrons with <1MeV energy created by the interaction of a 2TW laser beam with a nitrogen gas jet were injected and accelerated to more than 20MeV in a plasma wakefield generated by a 10TW laser beam in a helium gas jet. The energy gain occurred in a narrow time window of 3ps between the injection and acceleration laser beams, and within a tight spatial alignment of ∼10μm.
Mixing at 50GHz using a single-walled carbon nanotube transistor
Authors: Rosenblatt Sami , Lin Hao , Sazonova Vera , Tiwari Sandip , McEuen Paul L.
Published: October 2005

We have probed the electrical properties of top-gated single-walled carbon nanotube transistors at frequencies up to 50GHz by using the device as a microwave mixer. We find that the amplitude of the mixing signal decays as a function of frequency with a characteristic time constant that is limited by the setup. Despite the setup-limited cutoff frequency of ∼10GHz, we show that the devices still operate faster than 50GHz.
The Arabidopsis selenium-binding protein confers tolerance to toxic levels of selenium
Authors: Agalou Adamantia , Roussis Andreas , Spaink Herman P.
Published: October 2005

In the Arabidopsis genome there are three highly conserved homologues of the mammalian 56-kD selenium-binding protein (SBP). To study the function of SBP in this model plant, we used a transgenic approach by constitutively overexpressing and down-regulating the endogenous Atsbp1 gene. In the latter case, we employed both a conventional antisense method and gene silencing by intron-containing hairpin RNAs. Atsbp1-overexpressing and silenced plants were phenotypically normal, under standard growth conditions, when compared with wild type plants. Transgenic plants exhibited different growth responses to exogenously supplied selenite, which correlated with the expression levels of Atsbp1. Plants with increased Atsbp1 transcript levels showed enhanced tolerance to selenite, while plants with reduced levels were more sensitive. Our results indicate that, although Atsbp1 does not play a detectable role in the regulation of developmental processes under normal growth conditions, it appears to be involved in processes controlling tolerance of Arabidopsis to selenium toxicity.
Hydraulic efficiency of the leaf venation system in sun- and shade-adapted species
Authors: Nardini Andrea , Gortan Emmanuelle , Salleo Sebastiano
Published: October 2005

We tested the hypothesis that leaf hydraulics is correlated with the light adaptation of different plant species and specifically that the hydraulic resistance of the leaf venation (Rvenation) is lower in sun- than in shade-adapted species. Rvenation was measured in six sun- and six shade-adapted species with a high-pressure flow meter (HPFM). The number of conduits at the proximal third of the midrib was counted and the diameter of the widest conduits together with vein density were measured. Rvenation was higher in shade species than in sun species and it was negatively correlated with the mean diameter of the widest conduits. Maximum leaf conductance to water vapour recorded for the different species was negatively correlated with the corresponding Rvenation. Sun-adapted species coping with the high water demand typical of sunny habitats appeared to have developed a highly efficient conducting system to supply living mesophyll cells with water. In contrast, species adapted to shady habitats showed higher Rvenation values according to their lower need for investment of carbon into producing wide conduits in the leaf.
The “robust yet fragile” nature of the Internet
Authors: Doyle John C. , Alderson David L. , Li Lun , Low Steven , Roughan Matthew , Shalunov Stanislav , Tanaka Reiko , Willinger Walter
Published: October 2005

The search for unifying properties of complex networks is popular, challenging, and important. For modeling approaches that focus on robustness and fragility as unifying concepts, the Internet is an especially attractive case study, mainly because its applications are ubiquitous and pervasive, and widely available expositions exist at every level of detail. Nevertheless, alternative approaches to modeling the Internet often make extremely different assumptions and derive opposite conclusions about fundamental properties of one and the same system. Fortunately, a detailed understanding of Internet technology combined with a unique ability to measure the network means that these differences can be understood thoroughly and resolved unambiguously. This article aims to make recent results of this process accessible beyond Internet specialists to the broader scientific community and to clarify several sources of basic methodological differences that are relevant beyond either the Internet or the two specific approaches focused on here (i.e., scale-free networks and highly optimized tolerance networks).
Interstitial cells of Cajal mediate mechanosensitive responses in the stomach
Authors: Won Kyung-Jong , Sanders Kenton M. , Ward Sean M.
Published: October 2005

Changes in motor activity are a basic response to filling of smooth muscle organs. Responses to gastric filling, for example, are thought to be regulated by neural reflexes. Here, we demonstrate a previously uncharacterized aspect of stretch-dependent responses in visceral smooth muscles that is mediated by mechanosensitive interstitial cells of Cajal. Length ramps were applied to the murine antral muscles while recording intracellular electrical activity and isometric force. Stretching muscles by an average of 27 ± 1% of resting length resulted in 5 mN of force. Increasing length caused membrane depolarization and increased slow-wave frequency. The responses were dependent on the rate of stretch. Stretch-dependent responses were not inhibited by neuronal antagonists or nifedipine. Increases in slow-wave frequency, but not membrane depolarization, were inhibited by reducing external Ca
2+
(100 μM) and by Ni
2+
(250 μM). Responses to stretch were inhibited by indomethacin (1 μM) and were absent in cyclooxygenase II-deficient mice, suggesting that cyclooxygenase II-derived eicosanoids may mediate these responses. Dual microelectrode impalements of muscle cells within the corpus and antrum showed that stretch-induced changes in slow-wave frequency uncoupled proximal-to-distal propagation of slow waves. This uncoupling could interfere with gastric peristalsis and impede gastric emptying. Stretch of antral muscles of
W
/

W
V

mice, which lack intramuscular interstitial cells of Cajal, did not affect membrane depolarization or slow-wave frequency. These data demonstrate a previously uncharacterized nonneural stretch reflex in gastric muscles and provide physiological evidence demonstrating a mechanosensitive role for interstitial cells of Cajal in smooth muscle tissues.
Adaptive evolution of heparanase in hypoxia-tolerantSpalax: Gene cloning and identification of a unique splice variant
Authors: Nasser Nicola J. , Nevo Eviatar , Shafat Itay , Ilan Neta , Vlodavsky Israel , Avivi Aaron
Published: October 2005

Heparan sulfate (HS) side chains of HS proteoglycans bind to and assemble extracellular matrix proteins and play important roles in cell–cell and cell–extracellular matrix interactions. HS chains bind a multitude of bioactive molecules and thereby function in the control of multiple normal and pathological processes. Enzymatic degradation of HS by heparanase, a mammalian endoglycosidase, affects the integrity and functional state of tissues and is involved in, among other processes, inflammation, angiogenesis, and cancer metastasis. Here, we report the cloning of heparanase from four Israeli species of the blind subterranean mole rat (Spalax ehrenbergisuperspecies), 85% homologous to the human enzyme. Unlike its limited expression in human tissues, heparanase is highly expressed in diverseSpalaxtissues. Moreover, we have identified a unique splice variant of theSpalaxenzyme lacking 16 aa encoded by exon 7. This deletion resulted in a major defect in trafficking and processing of the heparanase protein, leading to a loss of its enzymatic activity. Interspecies variation was noted in the sequence and in the expression of the splice variant of the heparanase gene in blind mole rats living under different ecogeographical stresses, indicating a possible role in adaptation to stress inSpalaxevolution.
Sample size determination for the false discovery rate
Authors: Pounds Stan , Cheng Cheng
Published: October 2005

Motivation: There is not a widely applicable method to determine the sample size for experiments basing statistical significance on the false discovery rate (FDR).

Results: We propose and develop the anticipated FDR (aFDR) as a conceptual tool for determining sample size. We derive mathematical expressions for the aFDR and anticipated average statistical power. These expressions are used to develop a general algorithm to determine sample size. We provide specific details on how to implement the algorithm for a k-group (k ≥ 2) comparisons. The algorithm performs well for k-group comparisons in a series of traditional simulations and in a real-data simulation conducted by resampling from a large, publicly available dataset.

Availability: Documented S-plus and R code libraries are freely available from

Contact:  stanley.pounds@stjude.org

Supplementary information: Supplementary data are available at Bioinformatics online.
An attempt to define allergen-specific molecular surface features: a bioinformatic approach
Authors: Furmonaviciene Ruta , Sutton Brian J. , Glaser Fabian , Laughton Charlie A. , Jones Nick , Sewell Herb F. , Shakib Farouk
Published: October 2005

Allergens are proteins that elicit T helper lymphocyte type 2 (Th2) responses culminating in IgE antibody production and allergic disease. However, we have no answer to the fundamental question of why certain proteins are allergens, while others are not. We hypothesized that analysis of the surface of diverse allergens may reveal common structural features which might enable them to be recognized as Th2-inducing antigens by cells of the innate immune system. We have therefore used the ConSurf server to search for allergen-specific motifs. This has enabled us to identify residue conservation patterns in the homologues of Ara t 8 (plant profilin), Act c 1 (actinidin), Bet v 1 (plant pathogenesis-related protein) and Ves v 5 (venom allergen). The results demonstrate the presence of allergen-specific patches consisting of an unusually high proportion of surface-exposed hydrophobic residues. The patches that have been identified may represent molecular patterns recognizable by cells of the innate immune system.

Contact:  farouk.shakib@nottingham.ac.uk

Supplementary Information:
Improved approach for proteochemometrics modeling: application to organic compound—amine G protein-coupled receptor interactions
Authors: Lapinsh Maris , Prusis Peteris , Uhlén Staffan , Wikberg Jarl E. S.
Published: October 2005

Motivation: Proteochemometrics is a novel technology for the analysis of interactions of series of proteins with series of ligands. We have here customized it for analysis of large datasets and evaluated it for the modeling of the interaction of psychoactive organic amines with all the five known families of amine G protein-coupled receptors (GPCRs).

Results: The model exploited data for the binding of 22 compounds to 31 amine GPCRs, correlating chemical descriptions and cross-descriptions of compounds and receptors to binding affinity using a novel strategy. A highly valid model (q  2 = 0.76) was obtained which was further validated by external predictions using data for 10 other entirely independent compounds, yielding the high q  2ext = 0.67. Interpretation of the model reveals molecular interactions that govern psychoactive organic amines overall affinity for amine GPCRs, as well as their selectivity for particular amine GPCRs. The new modeling procedure allows us to obtain fully interpretable proteochemometrics models using essentially unlimited number of ligand and protein descriptors.

Contact:  jarl.wikberg@farmbio.uu.se

Supplementary information: Supplementary data are available at Bioinformatics online.
Production of ammonium by Helicobacter pylori mediates occludin processing and disruption of tight junctions in Caco-2 cells
Authors: Lytton Simon D. , Fischer Wolfgang , Nagel Wolfram , Haas Rainer , Beck Franz X.
Published: October 2005

Tight junctions, paracellular permeability barriers that define epithelial cell polarity, play an essential role in transepithelial transport, cell–cell adhesion and lymphocyte transmigration. They are also important for the maintenance of innate immune defence and intestinal antigen uptake. Ammonium () is elevated in the gastric aspirates of Helicobacter pylori-infected patients and has been implicated in the disruption of tight-junction functional integrity and the induction of gastric mucosal damage during H. pylori infection. The precise mechanism of the effect of ammonium and the molecular targets of ammonium in host tissue are not yet identified. To study the effects of ammonium on epithelial tight junctions, the human colon carcinoma cell line Caco-2 was cultured on permeable supports and the transepithelial resistance (TER) was measured at different time intervals following exposure to ammonium salts or H. pylori-derived ammonium. A biphasic response to treatment with ammonium was found. Acute exposure to ammonium salts or NH3/ derived from urea metabolism by wild-type H. pylori resulted in a 20–30 % decrease in TER. After 24 h, the NH4Cl-treated cells showed a partial recovery of TER. In contrast, the control culture, or cultures that were exposed to supernatants derived from urease-deficient H. pylori, showed no significant decrease in TER. Occludin-specific immunoblots revealed the expression of a low-molecular-weight form of occludin of 42 kDa upon NH3/ exposure. The results indicate that modulation of tight-junction function by H. pylori is ammonium-dependent and linked to the accumulation of a low-molecular-weight and detergent-soluble form of occludin.
Regulation of type 1 fimbriae synthesis and biofilm formation by the transcriptional regulator LrhA of Escherichia coli
Authors: Blumer Caroline , Kleefeld Alexandra , Lehnen Daniela , Heintz Margit , Dobrindt Ulrich , Nagy Gábor , Michaelis Kai , Emödy Levente , Polen Tino , Rachel Reinhard , Wendisch Volker F. , Unden Gottfried
Published: October 2005

Type 1 fimbriae ofEscherichia colifacilitate attachment to the host mucosa and promote biofilm formation on abiotic surfaces. The transcriptional regulator LrhA, which is known as a repressor of flagellar, motility and chemotaxis genes, regulates biofilm formation and expression of type 1 fimbriae. Whole-genome expression profiling revealed that inactivation oflrhAresults in an increased expression of structural components of type 1 fimbriae.In vitro, LrhA bound to the promoter regions of the twofimrecombinases (FimB and FimE) that catalyse the inversion of thefimApromoter, and to the invertible element itself. TranslationallacZfusions with these genes and quantification offimEtranscript levels by real-time PCR showed that LrhA influences type 1 fimbrial phase variation, primarily via activation of FimE, which is required for the ON-to-OFF transition of thefimswitch. Enhanced type 1 fimbrial expression as a result oflrhAdisruption was confirmed by mannose-sensitive agglutination of yeast cells. Biofilm formation was stimulated bylrhAinactivation and completely suppressed upon LrhA overproduction. The effects of LrhA on biofilm formation were exerted via the changed levels of surface molecules, most probably both flagella and type 1 fimbriae. Together, the data show a role for LrhA as a repressor of type 1 fimbrial expression, and thus as a regulator of the initial stages of biofilm development and, presumably, bacterial adherence to epithelial host cells also.
European Federation of Neurological Societies/Peripheral Nerve Society Guideline* on management of chronic inflammatory demyelinating polyradiculoneuropathy. Report of a joint task force of the European Federation of Neurological Societies and the Peripheral Nerve Society
Authors:   Joint Task Force of the EFNS and the PNS
Published: October 2005

Abstract  Background: Numerous sets of diagnostic criteria have sought to define chronic inflammatory demyelinating polyradiculoneuropathy (CIDP), and randomized trials and systematic reviews of treatment have been published. Objectives: The aim of this guideline was to prepare consensus guidelines on the definition, investigation, and treatment of CIDP. Methods: Disease experts and a representative of patients considered references retrieved from MEDLINE and Cochrane Systematic Reviews in May 2004 and prepared statements that were agreed in an iterative fashion. Recommendations: The Task Force agreed on good practice points to define clinical and electrophysiological diagnostic criteria for CIDP with or without concomitant diseases and investigations to be considered. The principal treatment recommendations were as follows: (1) intravenous immunoglobulin (IVIg) or corticosteroids should be considered in sensory and motor CIDP (level B recommendation); (2) IVIg should be considered as the initial treatment in pure motor CIDP (good practice point); (3) if IVIg and corticosteroids are ineffective, plasma exchange should be considered (level A recommendation); (4) if the response is inadequate or the maintenance doses of the initial treatment are high, combination treatments or adding an immunosuppressant or immunomodulatory drug should be considered (good practice point); and (5) symptomatic treatment and multidisciplinary management should be considered (good practice point).
Influence of aging on thermal and vibratory thresholds of quantitative sensory testing
Authors: Lin Yea‐Huey , Hsieh Song‐Chou , Chao Chi‐Chao , Chang Yang‐Chyuan , Hsieh Sung‐Tsang
Published: October 2005

Abstract  Quantitative sensory testing has become a common approach to evaluate thermal and vibratory thresholds in various types of neuropathies. To understand the effect of aging on sensory perception, we measured warm, cold, and vibratory thresholds by performing quantitative sensory testing on a population of 484 normal subjects (175 males and 309 females), aged 48.61 ± 14.10 (range 20–86) years. Sensory thresholds of the hand and foot were measured with two algorithms: the method of limits (Limits) and the method of level (Level). Thresholds measured by Limits are reaction‐time‐dependent, while those measured by Level are independent of reaction time. In addition, we explored (1) the correlations of thresholds between these two algorithms, (2) the effect of age on differences in thresholds between algorithms, and (3) differences in sensory thresholds between the two test sites. Age was consistently and significantly correlated with sensory thresholds of all tested modalities measured by both algorithms on multivariate regression analysis compared with other factors, including gender, body height, body weight, and body mass index. When thresholds were plotted against age, slopes differed between sensory thresholds of the hand and those of the foot: for the foot, slopes were steeper compared with those for the hand for each sensory modality. Sensory thresholds of both test sites measured by Level were highly correlated with those measured by Limits, and thresholds measured by Limits were higher than those measured by Level. Differences in sensory thresholds between the two algorithms were also correlated with age: thresholds of the foot were higher than those of the hand for each sensory modality. This difference in thresholds (measured with both Level and Limits) between the hand and foot was also correlated with age. These findings suggest that age is the most significant factor in determining sensory thresholds compared with the other factors of gender and anthropometric parameters, and this provides a foundation for investigating the neurobiologic significance of aging on the processing of sensory stimuli.
The phylogeny of Strepsiptera (Hexapoda)
Authors: Pohl Hans , Beutel Rolf Georg
Published: October 2005

Previous phylogenetic analyses of Strepsiptera have been limited to characters from only males or first instar larvae, and by poor taxonomic sampling. This investigation is the first cladistic analysis to use more than fourfold as many characters as any prior study, and a broader sampling of taxa. The analysis of 189 morphological characters of all stages of representatives of all extant strepsipteran families and characters of adult males of amber fossils results in the following branching pattern: (†Protoxenos+ (†Cretostylops + (†Mengea + (Mengenillidae + (Corioxenidae + (Bohartillidae + (Halictophagidae + (Elenchidae + (†Protelencholax + (Myrmecolacidae + (Callipharixenidae + (Xenidae + Stylopidae)))))))))))). The basal placement of the Baltic amber fossil †Protoxenos and the Burmese amber fossil †Cretostylops is well founded. Even though †Cretostylops is older than †Protoxenos it is almost certainly not the most basal strepsipteran group but the sister group of a clade comprising the Baltic amber fossil †Mengea + Strepsiptera s. str. (excl. stemlineage). Monophyly of Mengenillidae, Stylopidia, Stylopiformia s.l., Corioxenidae, Xenidae, and Stylopidae is confirmed. Mengenillidia is paraphyletic (with respect to †Mengea (Mengeidae)), Elenchidae (with respect to †Protelencholax) and the genus Stichotrema (with respect to the Baltic amber fossils). Thus Protelencholacidae fam. n. is described, and S. weitschati and S. triangulum are transferred to Palaeomyrmecolax. A ground plan of adult male Strepsiptera is provided and evolutionary interpretations are presented based on the obtained cladograms.

© The Willi Hennig Society 2005.
Primary diffuse large B‐cell non‐Hodgkin lymphoma of the paranasal sinuses: a report of 14 cases
Authors: Oprea C. , Cainap C. , Azoulay R. , Assaf E. , Jabbour E. , Koscielny S. , Lapusan S. , Vanel D. , Bosq J. , Ribrag V.
Published: October 2005

Sinonasal lymphoma (SL) is a rare form of extranodal lymphoma. Of 33 SL cases, 14 consecutive diffuse large B‐cell lymphomas were treated with CHOP (adriamycin, cyclophosphamide, vincristine and prednisone) or CHOP‐like chemotherapy regimen. Ten achieved complete remission (CR) and three achieved a partial remission. With a median follow‐up period of 80 months, seven patients relapsed or progressed [one case including central nervous system (CNS) progression]. Four of the relapses involved the CNS. Eight patients were alive, including seven in CR and six patients had died of their lymphoma. This observation strongly suggests that CNS prophylaxis should be used in SL.
A non‐accidental poisoning with ammonia in adolescence
Authors: Dilli D. , Bostancı İ. , Tıraş Ü. , Hatipoğlu N. , Dallar Y.
Published: October 2005

Introduction  Ammonia is an important chemical agent used in industry. Accidental inhalation of ammonia has resulted in upper airway and bronchoalveolar injury. If a large amount of ammonia is breathed, the agent can cause unconsciousness, shock and even death.

Case  In this article, we report a case of non‐accidental poisoning in adolescence. The patient was a 14‐year‐old boy and working as an apprentice at a workshop of a jeweller. He had drunk some amount of diluted ammonia by the force of another, 18‐year‐old, male apprentice. This patient presented with ammonia intoxication symptoms culminating in coma.

Conclusions  We reported this case as an unusual ammonia poisoning seen in adolescence.
Mum knows best? Psychological status in an oncology sample
Authors: Bruce S. , Rodgers J. , Firth M. , Freeston M.
Published: October 2005

Objective  To examine the influence of age, gender and diagnosis upon agreement of children's psychological status between children with cancer and their parents.

Methods  Total 51 families (49 mothers, 45 fathers and 51 children) completed the Strengths and Difficulties Questionnaire. Children's ages ranged from 11 to 16 years, with a mean age of 13.4 years. Eleven of the children had central nervous system (CNS) disease.

Results  Age, gender and diagnosis did not impact upon level of agreement between parents and children. There were no significant differences between father/child and mother/child reports of children's psychological status.

Conclusions  Both mothers and fathers are perceptive to their child's psychological status, and it is therefore satisfactory to consider their opinions about their children. Children in the age range 11–16 years are able to express their views with as much accuracy as parents irrespective of their gender and diagnosis and so should be included in assessment.
Treatment choices and experiences in attention deficit and hyperactivity disorder: relations to parents’ beliefs and attributions
Authors: Johnston C. , Seipp C. , Hommersen P. , Hoza B. , Fine S.
Published: October 2005

Background  Despite their potential to influence treatment decisions, parents’ beliefs and attitudes regarding attention deficit hyperactivity disorder (ADHD) have not been widely studied. This research examined relations between parents’ beliefs and attitudes and their experiences with different treatments for their children's ADHD.

Methods  Canadian parents of 73, 5‐ to 13‐year‐old, boys with ADHD completed questionnaires measuring beliefs about ADHD, attributions for ADHD behaviours, and treatment experiences.

Results  Parents reported using primarily behaviour management and stimulant medications in treating ADHD. Approximately half of the families also used diet/vitamin therapies. Parents were knowledgeable about ADHD and held generally accurate beliefs. They saw ADHD symptoms as predominantly internal to the child and as relatively enduring and pervasive. Parents’ beliefs were related to their use of different treatments and parents who used less empirically supported treatments were more likely to see ADHD behaviours as internal to the child, enduring and pervasive.

Conclusions  The findings highlight the importance of assessing parents’ use of alternate treatments for ADHD and the potential role of parents’ beliefs and attributions in shaping treatment choices.
Locomotion and nightwaking
Authors: Scher A. , Cohen D.
Published: October 2005

objective  In this study we addressed the association between two major achievements of infancy: independent locomotion and ‘sleeping through the night’ .

Methods  Mothers of 107 healthy infants aged between five and eight months completed a sleep questionnaire and a motor checklist.

Results and Conclusions  Infants who were already crawling had more bedtime difficulties and nightwaking than did pre‐crawlers. Among 7‐ and 8‐month‐old infants, locomotion predicted 17% of nightwaking variance, after controlling for age and gender. In discussing the developmental implications of locomotion we suggest that crawling may not only ‘broaden the mind’ but also ‘cost’ sleep. More studies, across time, on how motor development and sleep–wake regulation interrelate are recommended.
Family‐centred service: moving ideas into practice
Authors: Law M. , Teplicky R. , King S. , King G. , Kertoy M. , Moning T. , Rosenbaum P. , Burke‐Gaffney J.
Published: October 2005

Background  With parents more involved in their child's day‐to‐day care, concepts of family‐centred service (FCS) are increasingly adopted in children's health and rehabilitation service organizations.

Methods  In this paper, we report the results of a study to develop and evaluate educational materials for parents, service providers and health sciences students about FCS. The materials focus on the nature and philosophy of FCS, and the practical skills and systemic changes required for its implementation.

Results  Thirty‐six participants (12 families, 12 service providers and 12 rehabilitation science students) were randomly assigned to receive one of the six FCS educational packages, each containing three FCS educational sheets. Participants’ ratings of the format and content, and the impact of the FCS Sheets were very high, with overall means above 5.0 on a 7‐point scale. Using a mixed model analysis, we found significant differences in participants’ ratings of familiarity with the materials (students were less familiar than service providers). After statistical adjustment for familiarity, there were no significant differences between the groups or the packages on ratings of format and content or impact.

Conclusions  There were no significant differences in the way in which the participant groups rated the impact of the FCS Sheets and the specific packages did not have an effect on the participants’ ratings. The FCS educational materials, even those less familiar to participants, were rated highly on format and content, and impact. Results indicate that the material was perceived to be important to each group, and was formatted and written in a way that was easy to understand. This finding counters current recommendations in the knowledge transfer literature that suggest different versions should be written for different target groups.
Severe food‐allergic reactions in children across the UK and Ireland, 1998–2000
Authors: Reading Richard
Published: October 2005

.
 
Colver A.F.,
Nevantaus H.,
Macdougall C.F.
Cant A.J.
(
2005
)

,
94
,
689
–
695
.

Aim  Medical and lay concerns about food allergy are increasing. Whilst food allergy may be becoming more common, fatal reactions to food in childhood are very rare and their rate is not changing. We sought to establish how common severe reactions are.

Methods  Prospective survey, 1998–2000, of hospital admissions for food‐allergic reactions – conducted primarily through the British Paediatric Surveillance Unit, covering the 13 million children in the UK and Ireland.

Results  A total of 229 cases reported by 176 physicians in 133 departments, yielding a rate of 0.89 hospital admissions per 100 000 children per year. Sixty‐five per cent were male, 41% were under 4 years and 60% started at home. Main allergens were peanut (21%), tree nuts (16%), cow's milk (10%) and egg (7%). Main symptoms were facial swelling (76%), urticaria (69%), respiratory (66%), shock (13%), gastrointestinal (4%). Fifty‐eight cases were severe. Three were fatal, six near fatal, and 8 of these 9 had asthma with wheeze being the life‐threatening symptom. Three near‐fatal cases received excess intravenous epinephrine. None of the non‐fatal reactions resulted in mental or physical impairment. Seven of 171 non‐severe and 6/58 severe cases might have had a worse outcome if epinephrine auto‐injectors had been unavailable. Six of the severe cases might have benefited if auto‐injectors had been more widely prescribed.

Conclusion  In the UK and Ireland, the incidence of severe reactions is low. The study highlights that: (1) asthma is a strongly significant risk factor for a severe reaction and therefore warrants optimal management; (2) severe wheeze is a prominent feature of severe reactions and warrants optimal management; and (3) intravenous epinephrine should be used with great care if needed. Epinephrine auto‐injectors do not always prevent death, but our study design and data do not allow a definite statement about whether overall they are beneficial.
Conjugate vaccines. Time for more or less of them?
Authors: Reading Richard
Published: October 2005

?
 
Finn A.,
Heath P.
(
2005
)

,
90
,
667
–
669
.

No abstract.