bluuebunny/crossref_metadata_2025 huggingface dataset:
Accurate redox potentials of mononuclear iron, manganese, and nickel model complexes*
Authors: Galstyan Artur , Knapp Ernst‐Walter
Published: June 2008

Density functional theory (DFT) was combined with solution of the Poisson equation for continuum dielectric media to compute accurate redox potentials for several mononuclear transition metal complexes (TMCs) involving iron, manganese, and nickel. Progress was achieved by altering the B3LYP DFT functional (B4(XQ3)LYP‐approach) and supplementing it with an empirical correction term GX having three additional adjustable parameters, which is applied after the quantum‐chemical DFT computations. This method was used to compute 58 redox potentials of 48 different TMCs involving different pairs of redox states solvated in both protic and aprotic solvents. For the 58 redox potentials the root mean square deviation (RMSD) from experimental values is 65 mV. The reliability of the present approach is also supported by the observation that the energetic order of the spin multiplicities of the electronic ground states is fulfilled for all studied TMCs, if the influence from the solvent is considered as well. © 2008 Wiley Periodicals, Inc. J Comput Chem, 2009
Quantum chemical modeling of photoadsorption properties of the nitrogen‐vacancy point defect in diamond
Authors: Zyubin A. S. , Mebel A. M. , Hayashi M. , Chang H. C. , Lin S. H.
Published: June 2008

Quantum chemical calculations of geometric and electronic structure and vertical transition energies for several low‐lying excited states of the neutral and negatively charged nitrogen‐vacancy point defect in diamond (NV0 and NV−) have been performed employing various theoretical methods and basis sets and using finite model NCnHm clusters. Unpaired electrons in the ground doublet state of NV0 and triplet state of NV− are found to be localized mainly on three carbon atoms around the vacancy and the electronic density on the nitrogen and rest of C atoms is only weakly disturbed. The lowest excited states involve different electronic distributions on molecular orbitals localized close to the vacancy and their wave functions exhibit a strong multireference character with significant contributions from diffuse functions. CASSCF calculations underestimate excitation energies for the anionic defect and overestimate those for the neutral system. The inclusion of dynamic electronic correlation at the CASPT2 level leads to a reasonable agreement (within 0.25 eV) of the calculated transition energy to the lowest excited state with experiment for both systems. Several excited states for NV− are found in the energy range of 2–3 eV, but only for the 13E and 53E states the excitation probabilities from the ground state are significant, with the first absorption band calculated at ∼1.9 eV and the second lying 0.8–1 eV higher in energy than the first one. For NV0, we predict the following order of electronic states: 12E (0.0), 12A2 (∼2.4 eV), 22E (2.7–2.8 eV), 12A1, 32E (∼3.2 eV and higher). © 2008 Wiley Periodicals, Inc. J Comput Chem 2009
Stratigraphy, pollen and 14C dating of Johnston's Gum Hole, a late Quaternary fossil kauri (Agathis australis) site, Northland, New Zealand
Authors: D'Costa D. M. , Palmer J. , Hogg A. , Turney C. , Fifield L. K. , Ogden J.
Published: June 2008

Johnston's Gum Hole provides a discontinuous pollen record commencing late in Marine Isotope Stage 5 (MIS 5). In combination with other published records from the region, the Aupouri Peninsula is reconstructed to have been continuously forested through much of the last glacial cycle with the oscillation of Agathis‐ and Nothofagus‐dominated forest corresponding to stadials and interstadials, respectively. A northward latitudinal expansion of beech forest to 35° S is demonstrated. Kauri demise at the close of MIS 5 appears to have been due to flooding of the site. The elimination of kauri in MIS 3 was also associated with rewetting of the substrate, but could have been a more catastrophic event. The presence of both MIS 5 and MIS 3 kauri wood at the site suggests that other Aupouri peat swamps may also preserve timber of these ages, and demonstrate the potential of this area for providing MIS 3 and MIS 5 tree ring records. Copyright © 2008 John Wiley & Sons, Ltd.
Competitive affinity capillary electrophoresis assay based on a “hybrid” pre‐incubation/on‐capillary mixing format using an enantioselective aptamer as affinity ligand
Authors: Ruta Josephine , Ravelet Corinne , Baussane Isabelle , Fize Jennifer , Décout Jean‐Luc , Peyrin Eric
Published: June 2008

In this paper, we describe an aptamer‐based competitive affinity CE (ACE) assay involving (i) the pre‐incubation of the target (D‐arginine) and the specific ligand (anti‐D‐arginine‐L‐RNA aptamer) before (ii) the competition with the labeled target (dansylated D‐arginine) through an on‐capillary mixing strategy. The effects of some critical operating parameters such as the applied voltage and the sample‐aptamer mixture plug length on the assay sensitivity were investigated. The ACE assay appeared particularly dependent on the plug length of the pre‐incubated sample‐aptamer solution. It was shown that this “hybrid” strategy significantly improved the assay sensitivity relative to that obtained with a “full” on‐capillary mixing approach.
Selective determination of catechin, epicatechin and ascorbic acid in human urine using chiral capillary electrophoresis
Authors: El‐Hady Deia Abd , Gotti Roberto , El‐Maali Nagwa Abo
Published: June 2008

Chiral CE was successfully applied to the separation and quantification of catechin, epicatechin and ascorbic acid in some commercial drinks and human urine. Analysis involved the separation of analytes in less than 5.0 min at 240 nm with an untreated fused‐silica capillary under hydrodynamic injection mode. The running buffer consisted of 50 mM borate buffer with 3 mM β‐CD at pH 8.35. Detection limits for catechin, epicatechin and ascorbic acid were 0.028, 0.011 and 0.004 μg/mL, respectively. Linearity was investigated by selecting the ranges of calibration according to the amount of analytes in urine giving correlation coefficient percent (% r2) ranging between 99.4 and 99.6 at 99% confidence level. The maximum urinary excretion of catechin and epicatechin were noted at 2.0 and 4.0 h of the administrated dose. Unchanged catechin, epicatechin and ascorbic acid amounted to about 1.500, 8.696 and 0.003% of the administered dose in the 48.0 h urine collection. The proposed method achieved 99.2% completeness (n = 20) in urine media.
Experimental measurements and kinetic modeling of CO/H2/O2/NOx conversion at high pressure
Authors: Rasmussen Christian Lund , Hansen Jørn , Marshall Paul , Glarborg Peter
Published: June 2008

This paper presents results from lean CO/H2/O2/NOx oxidation experiments conducted at 20–100 bar and 600–900 K. The experiments were carried out in a new high‐pressure laminar flow reactor designed to conduct well‐defined experimental investigations of homogeneous gas phase chemistry at pressures and temperatures up to 100 bar and 925 K. The results have been interpreted in terms of an updated detailed chemical kinetic model, designed to operate also at high pressures. The model, describing H2/O2, CO/CO2, and NOx chemistry, is developed from a critical review of data for individual elementary reactions, with supplementary rate constants determined from ab initio CBS‐QB3 calculations. New or updated rate constants are proposed for important reactions, including OH + HO2 ⇋ H2O + O2, CO + OH ⇋ [HOCO] ⇋ CO2 + H, HOCO + OH ⇋ CO + H2O2, NO2 + H2 ⇋ HNO2 + H, NO2 + HO2 ⇋ HONO/HNO2 + O2, and HNO2(+M) ⇋ HONO(+M). Further validation of the model performance is obtained through comparisons with flow reactor experiments from the literature on the chemical systems H2/O2, H2/O2/NO2, and CO/H2O/O2 at 780–1100 K and 1–10 bar. Moreover, introduction of the reaction CO + H2O2 → HOCO + OH into the model yields an improved prediction, but no final resolution, to the recently debated syngas ignition delay problem compared to previous kinetic models. © 2008 Wiley Periodicals, Inc. Int J Chem Kinet 40: 454–480, 2008
High‐frequency rTMS over the supplementary motor area for treatment of Parkinson's disease
Authors: Hamada Masashi , Ugawa Yoshikazu , Tsuji Sadatoshi
Published: June 2008

Dysfunction of the basal ganglia‐thalamocortical motor circuit is a fundamental model to account for motor symptoms in Parkinson's disease (PD). Using high‐frequency repetitive transcranial magnetic stimulation (rTMS) over the supplementary motor area (SMA), we investigated whether modulation of SMA excitability engenders therapeutic effects on motor symptoms in PD. In this double‐blind placebo‐controlled study, 99 patients were enrolled and assigned randomly to SMA‐stimulation and sham‐stimulation groups. For SMA stimulation, 20 trains of 50 transcranial magnetic stimuli at 5 Hz were delivered at an intensity of 110% active motor threshold for leg muscles in one session. The sham stimulation was 20 trains of electric stimuli given through electrodes fixed on the head to mimic the cutaneous sensation during rTMS. Each session of intervention was carried out once a week for the first 8 weeks. The SMA stimulation, in contrast to the sham stimulation, engendered significant improvements in total scores and motor scores of the Unified Parkinson's Disease Rating Scale. Mean improvements in motor scores were 4.5 points in the SMA‐stimulation group and −0.1 points in the sham‐stimulation group. Results indicate that 5 Hz rTMS over SMA modestly improves motor symptoms in PD patients; SMA is a potential stimulation site for PD treatment. © 2008 Movement Disorder Society
A scapula deformity in two burials from medieval England
Authors: Mays S. A.
Published: June 2008

A scapula malformation is described in two burials from the site of the late medieval Dominican friary at Ipswich, UK. The changes appear most consistent with primary scapular neck dysplasia. One of the burials also showed clear signs of leprosy. The burials are of lay benefactors of the friary. The Ipswich Dominican friary had no known function as a leprosy hospital. Finding of burials of lepers other than in burial grounds of leprosaria is highly unusual for medieval England. Scapular neck dysplasia has a strong genetic component in its aetiology. This, coupled with its rarity, suggests a close genetic link between the two burials. The findings suggest that in this case, family ties with the friary overrode the normal medieval custom of interring lepers in leprosy hospitals. This illustrates that even rare skeletal variants may convey useful biocultural information about past populations. Copyright © 2008 John Wiley & Sons, Ltd.
Plasma polymerization of acetylene onto silica: an approach to control the distribution of silica in single elastomers and immiscible blends
Authors: Tiwari M. , Noordermeer J. W. M. , van Ooij Wim J. , Dierkes W. K.
Published: June 2008

Surface modification of silica by acetylene plasma polymerization is applied in order to improve the dispersion in and compatibility with single rubbers and their blends. Silica, used as a reinforcing filler for elastomers, is coated with a polyacetylene (PA) film under vacuum conditions. Water penetration measurements show a change in surface energy due to the PA‐film deposition. The weight loss measured by thermo‐gravimetric analysis (TGA) is higher for the PA‐coated silica compared to the untreated filler, confirming the deposition of the PA film on the silica surface. Time of flight‐secondary ion mass spectrometry (ToF‐SIMS) shows the well‐defined PA cluster peaks in the high mass region. Scanning electron microscopy (SEM) measurements show silica aggregates, coalesced by the coating with smooth and uniform surfaces, but without significant change in specific surface area. Elemental analysis by energy dispersive X‐ray spectroscopy (EDX) measurements also confirms the deposition of the polymeric film on the silica surface, as the carbon content is increased. The performance of single polymers and their incompatible blends based on S‐SBR and EPDM, filled with untreated, PA‐ and silane‐treated silica, is investigated by measurements of the bound rubber content, weight loss related to bound rubber, cure kinetics, reinforcement parameter, Payne effect, and mechanical properties. The PA‐ and silane‐modified silica‐filled pure S‐SBR and EPDM samples show a lower filler–filler networking compared to the unmodified silica‐filled elastomers. Decrease in the reinforcement parameter (αF) for the plasma‐polymerized silica‐filled samples also proves a better dispersion compared to silane‐modified and untreated silica‐filled samples. On the other hand, the PA‐silica‐filled samples show a higher bound rubber content due to stronger filler–polymer interactions. Finally, the PA‐silica‐filled pure EPDM and S‐SBR/EPDM blends show high tensile strength and elongation at break values, considered to be the result of best dispersion and compatibilization with EPDM. Copyright © 2008 John Wiley & Sons, Ltd.
Self‐initiation of the UV photopolymerization of brominated acrylates
Authors: Scherzer Tom , Knolle Wolfgang , Naumov Sergej , Elsner Christian , Buchmeiser Michael R.
Published: June 2008

Brominated aromatic acrylates were found to polymerize rapidly upon exposure to UV light. Moreover, they are able to initiate the UV‐induced polymerization of acrylic formulations that do not contain a conventional photoinitiator. In contrast, the corresponding unbrominated homologues are not effective as initiators. Investigations by real‐time FTIR spectroscopy have shown that the addition of only 1 wt % of a brominated acrylate is sufficient for an efficient initiation. Fast photopolymerization is achieved even if irradiation is carried out at λ > 300 nm where most acrylates do not absorb. Short‐lived transients were studied by laser flash photolysis. The triplet was found to show low sensitivity to oxygen which is because of its very short lifetime. Bromine radicals split of from the acrylates were trapped with bromine ions from tetraethyl ammonium bromide and detected as Br. The resulting quantum yields for the formation of bromine radicals are in the range of up to 0.3. Quantum chemical modeling was carried out to establish a mechanism for the release of bromine radicals. Both bromine and bromophenyl radicals are able to initiate the polymerization reaction. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 4905–4916, 2008
Alkyl chloride initiators for SET‐LRP of methyl acrylate
Authors: Lligadas Gerard , Percec Virgil
Published: June 2008

Single‐electron transfer living radical polymerization (SET‐LRP) proceeds by an outer‐sphere single‐electron transfer mechanism that induces a heterolytic bond cleavage of the initiating and propagatingR‐X (where X = Cl, Br, and I) species. Therefore, unlike the homolytic bond cleavage mechanism claimed for ATRP, SET‐LRP is expected to show a small dependence of the nature of the halide group on the apparent rate constant of activation. This means theR‐X with X = Cl, Br, and I must all be efficient initiators for SET‐LRP and no chain transfer must be observed in the case of initiators with X = Br and I. Here, we report the SET‐LRP of methyl acrylate initiated with the alkyl chlorides methyl‐2‐chloropropionate (MCP) and chloroform (CHCl3) and catalyzed by Cu(0)/Me6‐TREN/CuCl2in DMSO at 25 °C. A combination of kinetic and structural analysis was used to elucidate the MCP and CHCl3initiating behavior under SET‐LRP conditions, and to demonstrate the very small dependence of the SET‐LRP apparent rate constant of propagation on X while providing polymers with well defined architecture. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 4917–4926, 2008
Process‐free estimation of threshold current density of InAs quantum dot laser
Authors: Kumagai N. , Watanabe K. , Ishida M. , Nakata Y. , Hatori N. , Sudo H. , Yamamoto T. , Sugawara M. , Arakawa Y.
Published: June 2008

We have associated threshold current density of 1.3 μm InAs quantum dot (QD) laser diodes with the photoluminescence (PL) peak intensity of as‐grown wafers. These InAs QD laser wafers with stacking structure of 5 and 10 QD layers were grown by molecular beam epitaxy. PL measurements have carried out by high power excitation at room temperature. The PL peak intensity from ground state of InAs QDs has been inversely proportional to the threshold current density. Additionally, enhancement of PL peak intensity by increase in stacked QD layers has been corresponded to increase in maximum modal gain of QD laser. These results indicate that PL characterization by high power excitation is useful to estimate quality of as‐grown wafers without fabrication of QD laser diode. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
DFT study for the anisotropic epitaxial growth of a‐face ZnO(1120)
Authors: Ishii A. , Oda Y. , Fujiwara K.
Published: June 2008

The anisotropy of the epitaxial growth of a‐face ZnO(1120) is investigated using the density functional theory. The potential energy surface for Zn adatom and O adatom on the a‐face ZnO(1120) surface is calculated. The calculated results show us that the anisotropy of Zn adatom and O adatom is very large. The kinetic Monte Carlo simulation shows us that the such large anistropic migration barrier energy is the origin of the stripe structure. It is consistent with the experimentally observed anisotropic stripes on this surface. This is the abstract. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Fabrication of radial superlattices based on different hybrid materials
Authors: Deneke Christoph , Schumann Joachim , Engelhard Ronny , Thomas Jürgen , Sigle Wilfried , Zschieschang Ute , Klauk Hagen , Chuvilin Andrey , Schmidt Oliver G.
Published: June 2008

The fabrication of radial superlattices is demonstrated for three different hybrid material systems. Inherently strained pseudomorphic InGaAs/Fe3Si bilayers are rolled‐up to produce radial semiconductor/magnetic heterostructures. Apart from this epitaxially based material system, radial InAlGaAs/GaAs/Cr superlattices are investigated as an example for periodic semiconductor/metallic multilayers. Finally, rolled‐up InGaAs/GaAs/1‐hexadecanethiol layers are studied as a new class of semiconductor/organic short‐period superlattices. The radial superlattices are examined structurally, and particular attention is paid to the interfaces of the periodic hybrid heterostructures. These investigations reveal that, except for the semiconductor/organic hybrid material system, always a new interface layer forms, modifying the initial rolled‐up layer system. The study demonstrates the potential to fabricate periodic layer systems from pure single‐crystalline material, single‐crystalline/poly‐crystalline material as well as single‐crystalline/non‐crystalline material, which cannot be realized by any planar growth techniques. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
AlN/AlGaN/GaN MIS‐HEMTs with recessed source/drain Ohmic contact
Authors: Selvaraj S. Lawrence , Ito Tsuneo , Terada Yutaka , Egawa Takashi
Published: June 2008

AlN/AlGaN/GaN MIS‐HEMTs were grown on 4 inch silicon to suppress the gate leakage and achieve high breakdown. However the drain current density maximum obtained is low (361 mA/mm) for 15 μm MIS‐HEMTs. Since the contact resistance of the Ohmic contacts on the insulating AlN is high (5.1 Ωmm), the thin AlN layer was etched prior to the evaporation of the source‐drain Ohmic contact. Though the recessed Ohmic contact reduced the contact resistance to 2.5 Ωmm there is no improvement in the drain current density. The poor quality of the 2 nm AlN growth on silicon could be the possible reason behind the low drain current density. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
High‐temperature (300 °C) operation of npn ‐type GaN/InGaN double heterojunction bipolar transistors
Authors: Nishikawa Atsushi , Kumakura Kazuhide , Kasu Makoto , Makimoto Toshiki
Published: June 2008

We investigated high‐temperature (300 °C) characteristics of npn ‐type GaN/In0.07Ga0.93N double heterojunction bipolar transistors (DHBTs). The current gain obtained at 300 °C is as high as 308, although it decreases with increasing temperature. In Gummel plots, both base and collector current increases with increasing base‐emitter voltage. While the maximum collector current at 300 °C is similar to that at room temperature (RT), the maximum base current monotonically increases with increasing temperature. Consequently, the reduction of the current gain with temperature is attributed to the increase in the base current. Since the activation energy of the reduction of the current gain is larger than the expected value assuming the increase in the hole back‐injection current from the base into the emitter, an increase in the carrier concentration of the p ‐In0.07Ga0.93N base with temperature is considered to be attributed to the reduction of the current gain. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Resonant tunneling of electrons through single self‐assembled InAs quantum dot at room temperature studied with conductive AFM tip
Authors: Tanaka Ichiro , Tada Y. , Nakatani S. , Uno K. , Azuma M. , Umemura K. , Kamiya I. , Sakaki H.
Published: June 2008

Resonant tunneling of electrons through a quantum level in a self‐assembled InAs quantum dot (QD) has been measured by conductive atomic force microscopy (AFM) at room temperature. InAs QDs are embedded in a 3.4 nm‐thick AlAs layer, and capped with 8.3 nm‐thick GaAs layer on which surface InAs QDs are deposited as nano‐scale electrodes. Bringing the conductive AFM tip on the surface InAs QD which should be vertically aligned with a buried QD, a bias voltage is applied to the sample, and a current flowing via the buried QD is measured. Negative differential resistance attributed to electron resonant tunnelling through a quantized energy level in the buried QD is observed in the current‐voltage characteristics. The voltage loss by nano‐scale electrode and the dependence of resonance voltage on the size of the surface QD‐electrodes are discussed. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
226–273 nm AlGaN deep‐ultraviolet light‐emitting diodes fabricated on multilayer AlN buffers on sapphire
Authors: Hirayama Hideki , Yatabe Tohru , Noguchi Norimichi , Ohashi Tomoaki , Kamata Norihiko
Published: June 2008

We demonstrated AlGaN multi‐quantum‐well (MQW) deep‐ultraviolet (UV) light‐emitting diodes (LEDs) with wavelengths in the range of 226–273 nm on sapphire substrates. We achieved low threading dislocation density (TDD) AlN templates, formed through an ammonia (NH3) pulse‐flow multilayer (ML) growth technique, which were suitable for deep UV LEDs. The edge and screw‐type dislocation densities in these AlGaN buffer layers on ML‐AlN were 7.5×108 and 3.8×107 cm–2, respectively, as observed from cross‐sectional transmission electron microscope (TEM) images. We obtained single‐peaked operations of the LEDs with emission wavelengths of between 227‐273 nm. The output powers of the 253 nm and 261 nm LEDs were 0.4 mW and 1.0 mW respectively with injection currents of 100 mA, while maximum powers of 1.04 mW and 1.65 mW respectively were obtained under room temperature (RT) CW operation. The output power of a 227.5 nm LED was 0.11 mW with an injection current of 10 mA, and a maximum power of 0.15 mW was obtained under RT pulsed operation. The maximum external quantum efficiencies of the 261 nm and 227.5 nm LEDs were 0.23 and 0.2%, respectively. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Density functional theory calculations of electronic structure in silicon double quantum dots
Authors: Howard P. , Andreev A. , Williams D. A.
Published: June 2008

The finite difference method and anisotropic effective mass density functional theory (DFT) are used to calculate the electronic structure and wavefunctions of Silicon isolated double quantum dots. An optimised algorithm for determining the self‐consistent DFT potential was developed.

The effects of applying electric fields to push the electrons from one dot to another dot in the double quantum dot are studied. We demonstrate that depending on the structure parameters there are two regimes corresponding to the strong and weak coupling between the two dots. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The role of doping type in setback layers on wafer‐fused AlGaAs/GaAs/GaN HBTs
Authors: Lian Chuanxin , Xing Huili Grace , Chang Yu‐Chia , Fichtenbaum Nick
Published: June 2008

The role of doping type in the setback layer of wafer fused AlGaAs/GaAs/GaN HBTs has been investigated. The calculation assuming an ideal GaAs/GaN interface indicates that the current blocking effect due to the conduction band discontinuity between GaAs and GaN can be effectively alleviated by inserting a lightly doped GaAs setback layer with either n‐type or p‐type doping. And the n‐type setback is expected to work better than the p‐type setback for the same doping concentration. In experiments encouraging current gain of ∼ 8 was observed in wafer fused HBTs containing 30 nm GaAs setback layers of either n‐type or p‐type doping, substantially improved from the HBTs without any setback, but still much smaller than annealed as‐grown AlGaAs/GaAs/GaAs HBTs. It was proposed that the non‐ideal fused interface with a thin disordered material and interface charges/traps dominates the device performance, and that likely both types of fused HBTs (setback doping concentration is ∼ 1 × 1017 cm–3) have similar band diagrams after taking into account impurity redistribution near the interface. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Diamond FETs on boron‐implanted and high‐pressure and high‐temperature annealed homoepitaxial diamond
Authors: Ueda Kenji , Yamauchi Yoshiharu , Kasu Makoto
Published: June 2008

By combining ion‐implantation and high‐pressure and high‐temperature (HPHT) annealing, we have obtained boron (B)‐implanted diamond layers with a high a hole concentration and mobility and succeeded in fabricating diamond FETs using the B‐implanted layers. For a B dose of 3×1015 cm–2, a sheet hole concentration and mobility of 1.6×1013 cm–2 and 41 cm2/Vs at 300 K were obtained. Diamond FETs fabricated on the B‐implanted layer showed maximum drain current of 0.15 mA/mm at gate voltage of ‐2 V and maximum breakdown voltage of 530 V, corresponding to ∼1.1 MV/cm. The breakdown voltage value is comparable to those of Schottky diodes using B‐doped CVD diamond films. These results confirm the high quality of the B‐implanted and HPHT‐annealed layers. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Mixed ℋ︁2/ℋ︁∞ nonlinear filtering
Authors: Aliyu M. D. S. , Boukas E. K.
Published: June 2008

In this paper, we consider the mixed ℋ︁2/ℋ︁∞ filtering problem for affine nonlinear systems. Sufficient conditions for the solvability of this problem with a finite‐dimensional filter are given in terms of a pair of coupled Hamilton–Jacobi–Isaacs equations (HJIEs). For linear systems, it is shown that these conditions reduce to a pair of coupled Riccati equations similar to the ones for the control case. Both the finite‐horizon and the infinite‐horizon problems are discussed. Simulation results are presented to show the usefulness of the scheme, and the results are generalized to include other classes of nonlinear systems. Copyright © 2008 John Wiley & Sons, Ltd.
Reforming the undergraduate experience
Authors: VanderPol Diane , Brown Jeanne M. , Iannuzzi Patricia
Published: June 2008

This chapter examines common objectives in some of the major initiatives in higher education. It highlights the role of librarians and libraries in higher education reform.
Global educational goals, technology, and information literacy in higher education
Authors: Snavely Loanne
Published: June 2008

In today's rapidly evolving environment, information literacy is a key underlying element in global educational goals and in disciplinary learning in higher education; ultimately it is essential in producing lifelong learners.
Information literacy and first‐year students
Authors: Orme William A.
Published: June 2008

This chapter discusses factors to consider when introducing information literacy concepts to first‐year university students, including ways to think about the concept of information literacy, the unique nature of first‐year students, and the role faculty can play in introducing students to a new information environment.
Dynamic purposeful learning in information literacy
Authors: Kenedy Robert , Monty Vivienne
Published: June 2008

Faculty and librarians have been developing newer and better ways of imparting information literacy, recognizing that it is an important aspect of developing crucial critical skills in their students. We discuss how student learning is enhanced as the result of ongoing collaboration. Through what we call Dynamic Purposeful Learning (DPL) and the collaborative process, students learn dynamic information literacy and online research skills.
Three‐ and four‐dimensional ultrasound: new methods for evaluating fetal thoracic anomalies
Authors: Achiron R. , Gindes L. , Zalel Y. , Lipitz S. , Weisz B.
Published: June 2008

Objective

To study three‐ (3D) and four‐dimensional (4D) ultrasound applications for the evaluation of fetal thoracic anomalies.

Methods

Volume datasets of 23 fetuses with thoracic anomalies were acquired with static 3D and cine 4D ultrasound, i.e. spatiotemporal image correlation (STIC) mode. The volumes were analyzed and displayed by multiplanar and tomographic ultrasound imaging (TUI) modes and static volume contrast imaging (VCI). Color Doppler was added to the volumes acquired, and various rendering modes were used to display the volume datasets.

Results

The mean gestational age at evaluation was 22 (range, 14–34) weeks. The anomalies were identified as: diaphragmatic hernia (n = 5), lung dysplasia (n = 11), skeletal dysplasia with small thorax/thanatophoric dysplasia (n = 2), abnormal situs (n = 2), hydrothorax (n = 2) and esophageal atresia (n = 1). The TUI mode achieved optimal display of the thorax, thereby aiding the diagnosis of diaphragmatic hernia and lung dysplasia. In right diaphragmatic hernias, the VCI mode proved invaluable as it distinguished liver from lung tissue. High‐definition color Doppler with glass‐body rendering significantly contributed to the detection of abnormal vascularization in lung dysplasia. Maximal transparent mode with a transvaginal transducer provided accurate diagnosis of skeletal dysplasia in the first trimester. Situs abnormalities were best viewed with a minimal transparent mode, in which abnormal organs and positions of vessels were clearly identified. Pleuroamniotic shunt localization was monitored precisely by 3D in a fetus with hydrothorax, and inversion mode added important information regarding the size of an esophageal pouch in a fetus with esophageal atresia.

Conclusion

The 3D‐4D technique is a novel, useful sonographic tool for evaluating the fetal thorax. It enhances precise diagnosis and provides better spatial visualization of the anomalies involved. Copyright © 2008 ISUOG. Published by John Wiley & Sons, Ltd.
Validation of Concept Mapping Between PNDS and SNOMED CT
Authors: Westra Bonnie L. , Bauman Rhonda , Delaney Connie W. , Lundberg Cynthia B. , Petersen Carol
Published: June 2008

THE PERIOPERATIVE NURSING DATA SET (PNDS) is a structured vocabulary developed by AORN to help document perioperative nursing practices.

THE PNDS HAS BEEN MAPPED To the Systematized Nomenclature of Medicine Clinical Terms (SNOMED CT) reference terminology model to support the electronic exchange of nursing data.

THIS STUDY VALIDATES the concept mapping between the PNDS and SNOMED CT, supporting an equivalent meaning of concepts between the two terminology systems. AORN J 87 (June 2008) 1217‐1229. © AORN, Inc, 2008.
The Effect of Nurse Staffing Patterns on Medical Errors and Nurse Burnout
Authors: Garrett Connie
Published: June 2008

HOSPITAL ADMINISTRATORS frequently rely on the use of mandatory or voluntary overtime to cover staff nurse vacancies. This practice is common in the perioperative setting, but it can lead to staff‐member fatigue that may adversely affect patient safety.

THIS LITERATURE REVIEW explores the effect that nurse staffing patterns have on the frequency of medical errors, fatigue, and nurse burnout.

THE EVIDENCE INDICATES that inadequate nurse staffing leads to adverse patient outcomes and increased nurse burnout. Hospital administrators should invest in adequate nurse staffing to improve patient safety and increase nurse retention. AORN J 87 (June 2008) 1191‐1204. © AORN, Inc, 2008.
Blood Conservation in a Congenital Cardiac Surgery Program
Authors: John Tracey , Rodeman Roberta , Colvin Roslyn
Published: June 2008

BLOODLESS SURGERY PROGRAMS are being instituted because of increasing public concerns about blood transfusions and the need to accommodate some patients' religious beliefs. Patients' desires to forego transfusion must be identified during the preoperative screening process and subsequently reflected on the surgical consent.

PATIENTS ARE MANAGED preoperatively with erythropoietin and dietary supplements. The surgical team employs a variety of intraoperative and postoperative blood conservation techniques to help avoid the need for transfusion.

A RETROSPECTIVE REVIEW of congenital cardiac procedures in a blood conservation program confirmed that bloodless cardiac surgery is effective. AORN J 87 (June 2008) 1180‐1186. © AORN, Inc, 2008.
Safe Positioning for Neurosurgical Patients
Authors: St‐Arnaud Danielle , Paquin Marie‐Josée
Published: June 2008

POSITIONING THE PATIENT for surgery is an important part of perioperative nursing care that should not be underemphasized. The combined factors of time, mechanical pressure, and immobility increase the risk of tissue damage.

THE OBJECTIVES of perioperative positioning activities are to balance optimal surgical exposure with the prevention of any injury related to position and to maintain normal body alignment without excess flexion, extension, or rotation.

GENERAL PRINCIPLES OF POSITIONING and specific considerations with surgical rationale are presented in this article for each of the commonly used neurosurgical positions (eg, supine, knee‐chest, prone, lateral, park‐bench, sitting). AORN J 87 (June 2008) 1156‐1168. © AORN, Inc, 2008.
The extent of laminectomy affects pain‐related behavior in a rat model of neuropathic pain
Authors: Košta Vana , Kojundžić Sanja Lovrić , Sapunar Liana Cambj , Sapunar Damir
Published: June 2008

One of the unresolved questions in neuropathic pain research is whether we can prevent or reverse mechanical hyperalgesia by rhizotomy or ganglionectomy. However, one of the obstacles in answering that question is lack of a standardized surgical procedure used in experimental ganglionectomy. We tested the hypothesis that laminectomy performed during ganglionectomy induces lumbar column deformity. We further examined whether spinal deformity is a source of pain‐related behavior. Five conditions were studied. Fifth and sixth lumbar (L5 and L6) ganglionectomy were performed in rats using either minimal or extensive laminectomy technique. Two other groups had minimal and extensive laminectomy without ganglionectomies. A final control group had no surgery. Sensory responsiveness of the plantar aspect of the hind paw was repeatedly tested, and a plain radiograph in anteroposterior projection was made to assess the extent of deformity by measurement of deformity angles. Hyperalgesia resulted in groups with extensive laminectomy regardless of performance or absence of ganglionectomy, while in groups with minimal laminectomy there was no increase in pain‐related behavior. Lateral deformity of the spine was observed in rats with or without ganglionectomy, confirming that laminectomy can produce deformity. The extent of deformity was more pronounced in rats exposed to the extensive laminectomy. Our results indicate that laminectomy can produce spine deformity and that there is a direct relationship between the extent of laminectomy and the development of mechanical hypersensitivity. The data presented suggest that there is a need for standardization of laminectomy procedure in rat experimental pain models.
Single‐stage BAHA implantation in adults and children: Is it safe?
Authors: Kohan Darius , Morris Luc GT , Romo Thomas
Published: June 2008

Objective

Most surgeons perform pediatric bone‐anchored hearing aid (BAHA) implantation in two stages. This study examined the safety and efficacy of single‐stage BAHA implantation in adults and children.

Methods

Retrospective review of 32 ears: 18 pediatric (ages 6 to 13 years) and 14 adult patients who underwent single‐stage BAHA surgery between 2002 and 2006.

Results

A total of eight (25%) ears experienced complications. Overall, four (13%) ears required revision in the operating room. In the pediatric group, there were three (16.7%) ears with skin complications; two required operative revision. In the adult group, there were five (36%) ears with skin complications; two required operative revision.

Conclusions

In both adults and children, the single‐stage technique for BAHA implantation is safe and efficient. All complications were related to skin reaction. Safety profiles for 1‐ and 2‐stage surgery are similar, although the single‐stage procedure is more cost effective, avoids a second procedure, and provides for earlier hearing rehabilitation.
Histological features of osteofibrous hemangioma of the maxillofacial and skull base regions
Authors: Stamataki Sofia , Francis Howard W. , Holliday Michael , McCarthy Edward
Published: June 2008

Objectives

The histological spectrum of hemangiomas of the skull base and maxillofacial skeleton was evaluated to help explain the variability of the clinical and radiological presentation of this tumor.

Design

Retrospective case series.

Participants

Patients with surgically treated hemangiomas of the ear, sinuses, skull base, and maxillofacial bones.

Method

Light microscopic appearance of surgical specimens.

Results

Review of specimens from 23 tumors revealed two distinct histological patterns: 1) typical histology consisting of vascular spaces lined by endothelium and a thin layer of smooth muscle, and 2) osteofibrous histology that consisted of prominent fibrous tissue between vascular spaces associated occasionally with neo‐osseogenesis. The osteofibrous histology was more prevalent in the sinonasal and anterior skull base regions compared to the internal auditory canal.

Conclusions

Connective tissue and bony proliferation within hemangiomas vary according to tumor location and may have implications for the radiological appearance, ease of surgical resection, and associated morbidity.
Clinical evaluation of a novel internal nasal dilation stent for the improvement of nasal breathing
Authors: Brandt Michael G. , Moore Corey C. , Doyle Philip C.
Published: June 2008

Objective

This study assessed rhinometric improvement in nasal airflow, perceived comfort, and the utility of nasal dilation devices for individuals with nasal obstruction treated with an external nasal dilator (END) or a novel internal nasal dilation stent (INDS).

Study Design

Prospective, randomized, crossover trial.

Subjects

Individuals with symptoms of nasal obstruction.

Methods

Twenty‐three participants underwent rhinometry and a trial with a novel INDS and a validated END. Devices were used in a randomized, crossover fashion. Nasal airflow, maximum use, continuous use, comfort, and challenge with these devices were assessed.

Results

The END and INDS showed greater nasal airflow from baseline, with the INDS being significantly better than the END. The INDS was used significantly more than the END, and demonstrated significantly greater comfort and less associated challenge.

Conclusions

The novel INDS showed 3.4 times improved nasal airflow from baseline, was used maximally and continuously longer than a validated END, and was judged to be significantly more tolerable.
Systematic review of the treatment of functional dysphonia and prevention of voice disorders
Authors: Jani Ruotsalainen , Jaana Sellman , Laura Lehto , Jos Verbeek
Published: June 2008

Objective

To evaluate the effectiveness of interventions for treating functional dysphonia or preventing voice disorders in adults.

Data Sources

We searched MEDLINE (1950 to 2006), EMBASE (1974 to 2006), CENTRAL (Issue 2 2006), CINAHL (1983 to 2006), PsychINFO (1967 to 2006), Science Citation Index (1986 to 2006), and the Occupational Health databases OSH‐ROM (February 2006).

Review Methods

Systematic review and meta‐analysis of randomized controlled trials. Included studies evaluated the effectiveness of interventions for 1) treating functional/nonorganic dysphonia or 2) preventing voice disorders. We identified six randomized controlled trials about treatment and two about prevention. Two authors independently extracted data and assessed trial quality.

Results

A combination of direct and indirect voice therapy, compared with no intervention, improves self‐reported (standardized mean difference −1.07; 95% CI −1.94 to −0.19), observerrated (weighted mean difference [WMD] −13.00; 95% CI −17.92 to −8.08), and instrumentally assessed vocal functioning (WMD −1.20; 95% CI −2.37 to −0.03) in adults with functional dysphonia. Effects are reported to remain for at least 14 weeks. Effects are similar in patients and in teachers and student teachers screened for voice problems. We found two studies that did not show voice training, compared with no intervention, to have a preventive effective in improving self‐reported vocal functioning. Assessment of publication bias showed that the real effect sizes are probably smaller.

Conclusion

Comprehensive voice therapy is effective in improving vocal performance in adults with functional dysphonia. There is no evidence of effectiveness of voice training in preventing voice disorders.
Accuracy of PTH assay and corrected calcium in early prediction of hypoparathyroidism after thyroid surgery
Authors: Cavicchi Ottavio , Piccin Ottavio , Caliceti Umberto , Fernandez Ignacio Javier , Bordonaro Carla , Saggese Domenico , Ceroni Alberto Rinaldi
Published: June 2008

Objective

To evaluate the accuracy of the intraoperative parathyroid hormone (ioPTH) and 6‐hour PTH (6hPTH) assay in predicting transient hypoparathyroidism after thyroidectomy.

Study Design

A nonrandomized prospective study was conducted on patients undergoing thyroid surgery.

Subjects and Methods

Of 138 patients undergoing thyroid surgery, intraoperative PTH was measured 10 minutes after gland removal. Serum calcium, magnesium, inorganic phosphorus, albumin, and PTH levels were assayed 6 and 16 hours after surgery and daily until patient discharge.

Results

The development of postoperative hypocalcemia was associated with low ioPTH (P < 0.0001) and 6hPTH (P < 0.0001) values, and the decline of PTH from baseline (P < 0.0001). The cutoff for percentage decline of ioPTH and 6hPTH (55.7% and 379%, respectively) was more accurate than an absolute value. Accuracy, and positive and negative predictive values were 88 percent, 63 percent, and 100 percent for ioPTH and 75 percent, 46 percent, and 100 percent for 6hPTH, respectively.

Conclusion

With the use of ioPTH decline in association with 16‐hour corrected calcium, it is possible to distinguish early normocalcemic patients from hypocalcemic ones in most cases.
Urinary leukotrienes in patients with nasal polyposis
Authors: Royer Michel , Guzmán María Antonieta , Gormaz Juan‐Pablo , Nazar Gonzalo
Published: June 2008

Objectives

To compare urinary leukotriene E4 (ULT) level in patients with nasal polyposis (NP) with and without aspirin intolerance and allergic rhinitis (AR), and correlate it with disease severity.

Study Design and Setting

Prospective study from November 2005 to November 2006. Patients with NP (n = 30) and AR (n = 35) were included. The concentration of ULT was measured in both groups. Oral provocation test with aspirin was performed to patients with NP. ULT level between both groups was compared and correlated with NP disease severity.

Results

ULT concentration was elevated on NP and AR. The patients with NP and aspirin intolerance (n = 4) presented higher levels of ULT compared to aspirin‐tolerant patients. Leukotriene concentration was not correlated with NP severity.

Conclusions

Patients with NP and aspirin intolerance have increased ULT excretion; thus their measurement can be used as an indicator of arachidonic acid metabolism alteration.
The Neogene–Recent Hatay Graben, South Central Turkey: graben formation in a setting of oblique extension (transtension) related to post-collisional tectonic escape
Authors: BOULTON SARAH J. , ROBERTSON ALASTAIR H. F.
Published: June 2008

Structural data and a regional tectonic interpretation are given for the NE–SW-trending Hatay Graben, southern Turkey, within the collision zone of the African (Arabian) and Eurasian (Anatolian) plates. Regional GPS and seismicity data are used to shed light on the recent tectonic development of the Hatay Graben. Faults within Upper Cretaceous to Quaternary sediments are categorized as of first-, second- and third-order type, depending on their scale, location and character. Normal, oblique and strike-slip faults predominate throughout the area.The flanks of the graben are dominated by normal faults, mainly striking parallel to the graben, that is, 045–225°. In contrast, the graben axis exhibits strike-slip faults, trending 100–200°, together with normal faults striking 040–060° and 150–190° (a subset strikes 110–130°). Similarly orientated normal faults occur throughout Upper Cretaceous to Pliocene sediments, whereas strike-slip faults are mostly within Pliocene sediments near the graben axis. Stress inversion of slickenline data from mostly Pliocene sediments at ten suitable locations (all near the graben axis) show that σ3 directions (minimum stress axis ≈ extension direction) are uniform in the northeast of the graben but orientated at a high angle to the graben margins. More variable σ3 directions in the southwest may reflect local block rotations. During Miocene times, the Arabian and Anatolian plates collided, forming a foreland basin associated with flexurally controlled normal faulting. During the Late Miocene there was a transition from extension to transtension (oblique extension). The neotectonic Hatay Graben formed during the Plio-Quaternary in a transtensional setting. In the light of modern and ancient comparisons, it is suggested that contemporaneous strain was compartmentalized into large-scale normal faults on the graben margins and mainly small-scale strike-slip faults near the graben axis. Overall, the graben reflects Plio-Quaternary westward tectonic escape from a collision zone towards the east to a pre- or syn-collisional zone to the west in the Mediterranean Sea.
Geochronology and geochemistry of the c. 80 Ma Rutog granitic pluton, northwestern Tibet: implications for the tectonic evolution of the Lhasa Terrane
Authors: ZHAO TAI-PING , ZHOU MEI-FU , ZHAO JUN-HONG , ZHANG KAI-JUN , CHEN WEI
Published: June 2008

The Rutog granitic pluton lies in the Gangdese magmatic arc in the westernmost part of the Lhasa Terrane, NW Tibet, and has SHRIMP zircon U–Pb ages of c. 80 Ma. The pluton consists of granodiorite and monzogranite with SiO2 ranging from 62 to 72 wt% and Al2 O3 from 15 to 17 wt%. The rocks contain 2.33–4.93 wt% K2O and 3.42–5.52 wt% Na2O and have Na2O/K2O ratios of 0.74–2.00. Their chondrite-normalized rare earth element (REE) patterns are enriched in LREE ((La/Yb)n = 15 to 26) and do not show significant Eu anomalies (δEu = 0.68–1.15). On a primitive mantle-normalized trace element diagram, the rocks are rich in large ion lithophile elements (LILE) and poor in high field strength elements (HFSE), HREE and Y. Their Sr/Y ratios range from 15 to 78 with an average of 30. The rocks have constant initial 87Sr/86Sr ratios (0.7045 to 0.7049) and slightly positive ɛNd(t) values (+0.1 to +2.3), similar to I-type granites generated in an arc setting. The geochemistry of the Rutog pluton is best explained by partial melting of a thickened continental crust, triggered by underplating of basaltic magmas in a mantle wedge. The formation of the Rutog pluton suggests flat subduction of the Neo-Tethyan oceanic lithosphere from the south. Crustal thickening may have occurred in the Late Cretaceous prior to the India–Asia collision.