bluuebunny/crossref_metadata_2025 huggingface dataset:
Detection of an epidermoid cyst in the foot of a horse by use of magnetic resonance imaging
Authors: Sanz Macarena G. , Sampson Sarah N. , Schneider Robert K. , Gavin Patrick R. , Baszler Timothy V.
Published: June 2006

Case Description—A 4-year-old Quarter Horse stallion was evaluated because of a 10-month history of moderate (grade 3/5) left forelimb lameness (detectable during trotting over a smooth, hard surface).

Clinical Findings—No abnormalities were detected in either forelimb via palpation or application of hoof testers; however, lameness was eliminated after administration of a palmar digital nerve block in the left forelimb. Whereas radiography and ultrasonography did not identify any left forelimb foot abnormalities, magnetic resonance (MR) imaging revealed a circumscribed soft tissue mass in the distal aspect of the digital flexor tendon sheath (DFTS) dorsal to the lateral aspect of the deep digital flexor tendon. Subsequently, the left forelimb DFTS was injected with local anesthetic, which resulted in 90% improvement of the horse's lameness.

Treatment and Outcome—The distal aspect of the left forelimb DFTS was evaluated tenoscopically. The mass was removed under tenoscopic guidance, after which the distal digital annular ligament was transected. The horse received phenylbutazone orally for 10 days, and the left forelimb DFTS was injected with hyaluronic acid and methylprednisolone acetate 7 days after the surgery. Following a rehabilitation program, the horse was returned to full training at 6 months after surgery and competed successfully during a 2-year follow-up period.

Clinical Relevance—Use of MR imaging should be considered in all lame horses for which a definitive diagnosis cannot be made via radiography, ultrasonography, or other imaging techniques, especially when the lameness has been localized to a specific anatomic region by use of diagnostic anesthesia.
Evaluation of a balloon constant rate infusion system for treatment of septic arthritis, septic tenosynovitis, and contaminated synovial wounds: 23 cases (2002–2005)
Authors: Meagher Daniel T. , Latimer Federico G. , Sutter W. Wes , Saville William J. A.
Published: June 2006

Objective—To determine clinical findings and outcome in horses treated by means of a balloon constant rate infusion system.

Design—Retrospective case series.

Animals—23 horses.

Procedures—Medical records of horses examined at The Ohio State University veterinary teaching hospital from 2002 to 2005 that had septic arthritis, septic tenosynovitis, or penetration of a synovial structure and in which treatment involved a balloon constant rate infusion system were searched. Information pertaining to signalment, history, physical examination findings, clinicopathologic data, treatment, and duration of hospitalization was recorded.

Results—Mean ± SD duration of hospitalization was 11.5 ± 5.26 days. No correlation between duration of clinical signs and duration of hospitalization or duration of infusion pump use was detected, but correlations between WBC count and duration of hospitalization and WBC and duration of infusion-pump use were observed. All horses survived to discharge. Follow-up information was obtained on 17 horses, 16 of which were alive at the time of follow-up. Twelve of 13 horses for which followup information was available for at least 5 months were alive 5 months or longer after discharge. Thirteen of the 16 horses alive at follow-up were reported by owners as not lame, whereas the remaining 3 were mildly lame or intermittently moderately lame or had developed angular limb deformity in the contralateral limb.

Conclusions and Clinical Relevance—Balloon constant rate infusion systems may be used effectively in treatment of septic arthritis, septic tenosynovitis, and contaminated synovial wounds. Clinical response and long-term outcome appeared to be comparable to results obtained with other techniques.
Natural Sources and Heavy Metals
Authors: Buccolieri Alessandro , Buccolieri Giovanni , Dell'Atti Angelo , Perrone Maria Rita , Turnone Annarita
Published: June 2006

PTS, PM10 and PM2.5 samples have been collected at a rural site of south‐east Italy (40° 20' 13'' N; 18° 6' 47'' E) from June to October, 2004 to investigate natural and anthropogenic contributions on particulate matter and heavy metal mass concentrations. It is shown that sharp‐peak particulate‐matter concentrations have been recorded during most African dust outbreaks occurred over south‐east Italy. In particular, PM10 concentrations exceeding the 24‐hour limit value of 50 μg/m3 have been monitored during dust events.

Al, Cd, Cr, Cu, Fe, Mn, V, Ni, Pb, and Zn metal concentrations have been evaluated
by an inductively coupled plasma atomic emission spectrometer and Al mass concentrations >500 ng/m3 have been observed in PTS and PM10 samples during the advection of African dust particles. Accordingly to geochemical calculations Al, Fe, and Mn, have a significant crustal origin while, Cd, Cu, Pb, and Zn are of anthropogenic origin. Moreover, Fe resulted predominant in the coarse particle fraction, while Ni, Pb, V, and Zn were predominant in the fine particle fraction. It is also shown that Cd, Mn, Ni, Pb, and V concentrations never exceeded guide and/or limit values recommended by the World Health Organization and the European Council Directives.
Testing the Photosynthetic Bacterium Rhodobacter Sphaeroides as Heavy Metal Removal Tool
Authors: Buccolieri Alessandro , Italiano Francesca , Dell'Atti Angelo , Buccolieri Giovanni , Giotta Livia , Agostiano Angela , Milano Francesco , Trotta Massimo
Published: June 2006

We present some preliminary results relevant to the ability of the purple non‐sulphur bacterium Rhodobacter sphaeroides strain R26.1 to sequester heavy metals from contaminated growth media. The microorganism was chosen because of its significant tolerance to relatively high concentrations of the investigated ions Ni2+, Co2+, CrO42‐, and MoO42‐.

In this paper the optimized conditions for the bacterial growth and the sample preparation used to infer the ability of the microorganism to cope with metal pollutants are presented. Elemental analysis has been performed by inductively coupled plasma atomic emission spectrometry previous mineralization of samples by a microwave system.
Synthesis, characterization and in vitro cytotoxic effects of new organotin(IV)‐2‐maleimidopropanoates
Authors: Khan M. I. , Baloch Musa Kaleem , Ashfaq Muhammad , Obaidullah
Published: June 2006

Synthesis, spectral properties and in vitro cytotoxic behaviour of five new diorganotin(IV) complexes having general composition R′2SnR2 [R′ = 2‐maleimidopropanoic acid and R = Me(1), Et(2), n‐Bu(3), Ph(4), Bz(5)] have been investigated. Various spectroscopic methods like solid‐state FT IR, 119mSn Mössbauer and solution‐state multinuclear NMR (1H, 13C and 119Sn) have been employed for structural elucidation. In the solid state, [R2Sn(IV)]2+ moieties interacted with carboxylate group of the ligand in octahedral arrangement, while in the solution state 1–3 showed hyper‐coordination and 4 and 5 were tetrahedral. All these results were consistent with elemental analysis and MS data. These complexes were also screened for in vitro anti‐tumour, anti‐leishmanial and anti‐fungal activities, and structure–activity relationship have been proposed. Copyright © 2006 John Wiley & Sons, Ltd.
Removal of chromium (VI) from aqueous solutions using poly(4‐vinyl pyridine) beads
Authors: Arslan Metin , Yiğitoğlu Mustafa , Soysal Arif
Published: June 2006

Sorption of hexavalent chromium ions from aqueous solution by poly 4‐vinyl pyridine [Poly(4‐VP)] was studied. The batch method was applied for adsorption processes. The effects of initial ion concentration, time, pH and temperature on adsorption were investigated. A treatment time of 60 min was found to be sufficient to reach equilibrium. pH 3.0 was found as the optimum pH value for the process. The maximum adsorption performance was achieved at 86.7 mg g−1 using 500 mg L−1 Cr (VI) solutions. The process of adsorption of Cr (VI) was explained by Langmuir isotherm. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 2865–2870, 2006
Molecular transport of aliphatic hydrocarbons through styrene butadiene rubber/ethylene vinyl acetate blends
Authors: Padmini M. , Radhakrishnan C. K. , Sujith A. , Unnikrishnan G. , Purushothaman E.
Published: June 2006

Polymer blends based on styrene butadiene rubber and ethylene vinyl acetate (EVA) were prepared. The sorption and diffusion of four aliphatic hydrocarbons through the blends were investigated with temperatures of 26–56°C. Sulfur, dicumyl peroxide (DCP), and a mixed system consisting of sulfur and DCP (mixed) were used as crosslinking agents for the blends. Of the three systems, the peroxide vulcanized blends were found to exhibit the lowest penetrant uptake. The aliphatic liquid penetration through the matrix decreased with an increase in the EVA content in the blends, which was attributed to the semicrystalline nature of the EVA matrix. The experimental observations were correlated with the morphology of the blends. Diffusion and permeation coefficients were calculated from the sorption data. A slight deviation from the Fickian trend was observed for the mechanism of transport with an increase in the EVA content in the blends. The molecular mass between crosslinks and thermodynamic parameters of sorption were determined from swelling data. The experimental observations were compared with different theoretical models. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 2884–2897, 2006
Studies on urethane–allophanate networks based on hydroxyl‐terminated polybutadiene: Modeling of network parameters and correlation to mechanical properties
Authors: Sekkar V. , Narayanaswamy K. , Scariah K. J. , Nair P. R. , Sastri K. S. , Ang How Ghee
Published: June 2006

Hydroxyl‐terminated polybutadiene (HTPB)‐based allophanate–urethane networks were prepared by reacting HTPB with di‐isocyanates, such as toluene–di‐isocyanate (TDI), isophorone–di‐isocyanate (IPDI), and 4,4′‐di(socyanatocyclohexyl)methane (H12MDI) at stoichiometric ratios (r‐values) ranging from 1.0 to 1.5. The networks were characterized for mechanical and swell properties. The network parameters, such as “X,” which is the fraction of urethane groups involved in the allophanate formation, and effective chain length (Lx) were calculated from experimental crosslink density values determined from swell data, using α‐model equations developed by Marsh. Excellent linear correlations were obtained between mechanical properties and the calculated network parameters. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 2986–2994, 2006
Characterization of biodegradable polymers by inverse gas chromatography. II. Blends of amylopectin and poly(ε‐caprolactone)
Authors: Al‐Ghamdi Ali , Melibari Mohammad , Al‐Saigh Zeki Y.
Published: June 2006

Amylopectin (AP), a potato‐starch‐based polymer with a molecular weight of 6,000,000 g/mol, was blended with poly(ε‐caprolactone) (PCL) and characterized with inverse gas chromatography (IGC), differential scanning calorimetry (DSC), and X‐ray diffraction (XRD). Five different compositions of AP–PCL blends ranging from 0 to 100% AP were studied over a wide range of temperatures (80–260°C). Nineteen solutes (solvents) were injected onto five chromatographic columns containing the AP–PCL blends. These solutes probed the dispersive, dipole–dipole, and hydrogen‐bonding interactions, acid–base characteristics, wettability, and water uptake of the AP–PCL blends. Retention diagrams of these solutes in a temperature range of 80–260°C revealed two zones: crystalline and amorphous. The glass‐transition temperature (Tg) and melting temperature (Tm) of the blends were measured with these zones. The two zones were used to calculate the degree of crystallinity of pure AP and its blends below Tm, which ranged from 85% at 104°C to 0% at Tm. IGC complemented the DSC method for obtaining the Tg and Tm values of the pure AP and AP–PCL blends. These values were unexpectedly elevated for the blends over that of pure AP and ranged from 105 to 152°C for Tg and from 166 to 210°C for Tm. The Tm values agreed well with the XRD analysis data. This elevation in the Tg and Tm values may have been due to the change in the heat capacity at Tg and the dependence of Tg on various variables, including the molecular weight and the blend composition. Polymer blend/solvent interaction parameters were measured with a variety of solutes over a wide range of temperatures and determined the solubility of the blends in the solutes. We were also able to determine the blend compatibility over a wide range of temperatures and weight fractions. The polymer–polymer interaction coefficient and interaction energy parameter agreed well on the partial miscibility of the two polymers. The dispersive component of the surface energy of the AP–PCL blends was measured with alkanes and ranged from 16.09 mJ/m2 for pure AP to 38.26 mJ/m2 when AP was mixed with PCL in a 50/50% ratio. This revealed an increase in the surface energy of AP when PCL was added. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3076–3089, 2006
Thermodynamic Modeling of Hydrogen Adsorption on Carbon Nanotubes During CVD Growth
Authors: Barnard A. S.
Published: June 2006

The growth of carbon nanotubes using hydrogen plasmas has received much attention in recent years, but far less attention has been given to the effect of adsorbed hydrogen on the relative stability of the final, possibly defective, structures. Presented here is a general analytical model for describing the energetics and relative stability of defective carbon SWNTs in the presence of adsorbates. The model is parameterized for the case of hydrogen, using results obtained from first principles simulations, and is constructed around experimentally relevant parameters such as the concentrations and configurations of adsorbates on the nanotube walls.
Fabrication of Carbon Nanotube Field Emitters Using a Dip‐Coating Method
Authors: Song Y. I. , Kim G. Y. , Choi H. K. , Jeong H. J. , Kim K. K. , Yang C.‐M. , Lim S. C. , An K. H. , Jung K. T. , Lee Y. H.
Published: June 2006

A simple and robust dip‐coating method for fabricating carbon nanotube (CNT) field emitters has been proposed. The thin multiwalled (tMW)CNTs synthesized by CVD were dispersed in various solutions such as N,N‐dimethylformamide (DMF), isopropyl alcohol (IPA), N‐methyl‐2‐pyrrolidinone (NMP), and dichloroethane (DCE). The weak adhesion between CNTs and substrate, a serious drawback of the dip‐coating approach, was resolved by anchoring CNTs to the substrate via the melting of an indium layer. We found that the uniformity and density of the CNTs could be optimized by controlling the degree of dispersion of CNTs in solvents. The field‐emission characteristics are also discussed.
Electric‐Field‐Guided Growth of Carbon Nanotubes during DC Plasma‐Enhanced CVD
Authors: AuBuchon J. F. , Chen L.‐H. , Gapin A. I. , Jin S.
Published: June 2006

Carbon nanotubes (CNTs) have been grown aligned with the directions of electric fields in a DC plasma‐enhanced (DC PE) CVD process. The CNTs can be grown at various predefined angles with respect to the substrate. It is shown that the local electric field, even at the very surface of the substrates, can be inclined. The strength of the electric field inside the plasma sheath is estimated and the electric‐field directions near the surface of Si substrate where the CNTs grow are modeled. By control of the directions of these electric fields, several novel CNT morphologies are demonstrated, which could be useful for various applications.
Aerosol Catalyst Particles for Substrate CVD Synthesis of Single‐Walled Carbon Nanotubes
Authors: Queipo P. , Nasibulin A. G. , Jiang H. , Gonzalez D. , Kauppinen E. I.
Published: June 2006

Individual single‐walled carbon nanotubes (SWCNTs) were grown by a CVD method on thin SiO2 films using iron and carbon monoxide as the catalyst material and the carbon source, respectively. Catalyst particles were produced via physical vapor deposition (PVD) as an aerosol using a hot‐wire particle generator and then deposited by two different approaches. Particles collected onto the substrates by diffusion inside the reactor led to the production of large diameter SWCNTs (∼3–6 nm) with lengths up to 30 μm. An outside deposition, via electrostatic precipitator, resulted in the synthesis of longer SWCNTs (≥ 50 μm) with smaller diameters (< 2 nm).
Morphology‐Controllable CVD Synthesis of Carbon Nanomaterials on an Alkali‐Element‐Doped Cu Catalyst
Authors: Tao X. , Zhang X. , Cheng J. , Liu F. , Luo J. , Luo Z.
Published: June 2006

Several categories of carbon nanomaterials have been synthesized using an alkali element‐doped Cu catalyst by a simple CVD method. By controlling the reaction temperature, various products such as multibranched carbon nanotubes, carbon nanotubes filled with Cu nanocones at the tips (Cu‐CNTs), and Cu‐CNTs with carbon nanofiber tails can be obtained. Field‐emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), and high‐resolution (HR)TEM have been employed to characterize the products. It is proposed that the alkali‐element doping changes the electronic structure of the copper catalyst. The activity of the alkali‐element‐doped Cu catalyst shows dependence on the temperature.
Evolution of the Field‐Emission Properties of Individual Multiwalled Carbon Nanotubes Submitted to Temperature and Field Treatments
Authors: Purcell S. T. , Vincent P. , Rodriguez M. , Journet C. , Vignoli S. , Guillot D. , Ayari A.
Published: June 2006

Field‐emission (FE) electron and ion microscopies (FEM and FIM),I(V) characteristics, and FE energy spectroscopy (FEES) measurements have been made on individual multiwalled carbon nanotubes (MWNTs) at various stages of their evolution under various thermal and field treatments. Before the highest temperature treatments, the FE is produced by nanometer‐scale structures that have specific and known characteristics such as individual peaks in the total energy distributions (TEDs), highly curved Fowler–Nordheim (FN) plots, and strong local heating due to the Nottingham effect. After cleaning at up to 1600 K, the TEDs approached the well‐known form for FN tunneling from a free electron gas. As previously reported, they revealed and quantified strong heating at high FE currents induced by Joule heating along the MWNT. The TEDs gave a quantitative simultaneous measure of the temperature at the end of the MWNT,TA(which reached up to 2000 K), and its electrical resistanceR, thus allowing the determination ofR(TA).R(TA) decreased by ca. 70 % asTAincreased from 300 to 2000 K, indicating a nonmetallic behavior of the MWNT. Changes in the MWNT length due to the induced high temperatures above 1600 K could be followed using theI(V) characteristics. The high temperatures were accompanied by light emission due to incandescence for which the optical spectra was found to follow the Planck distribution. With the simultaneous measurements ofTAandR, the 1D heating problem could be reliably simulated to estimate the dependence of both electrical and thermal conductivities on temperature. This heating results in an excellent current stability by continuous desorption, and defines the maximum nanotube currents for high‐current applications
Differential expression of polycomb repression complex 1 (PRC1) members in the developing mouse brain reveals multiple complexes
Authors: Vogel Tanja , Stoykova Anastassia , Gruss Peter
Published: June 2006

Polycomb group (PcG) genes are regulators of body segmentation and cell growth, therefore being important players during development. PcG proteins form large complexes (PRC) that fulfil mostly repressive regulative functions on homeotic gene expression. Although expression of PcG genes in the brain has been noticed, the involvement of PcG genes in the processes of brain development is not understood. In this study, we analysed the expression patterns of PRC1 complex members to reveal PcG proteins that might be relevant for mouse brain development. Using in situ hybridisation, we show PRC1 activity in proliferative progenitor cells during neurogenesis, but also in maturated neuronal structures. PRC1 complex compositions vary in a spatial and temporal controlled manner during mouse brain development, providing cellular tools to act in different developmental contexts of cell proliferation, cell fate determination, and differentiation. Developmental Dynamics 235:2574–2585, 2006. © 2006 Wiley‐Liss, Inc.
Pertussis toxin activates adult and neonatal naive human CD4+ T lymphocytes
Authors: Tonon Sandrine , Badran Bassam , Benghiat Fleur Samantha , Goriely Stanislas , Flamand Véronique , Willard‐Gallo Karen , Willems Fabienne , Goldman Michel , De Wit Dominique
Published: June 2006

Pertussis toxin (PTX) is known to be mitogenic for T lymphocytes, but its direct action on naive human T cells has not been specified. Herein, we show that PTX induces the proliferation of purified adult CD45RA+CD4+ T cells independently of its ADP‐ribosyltransferase activity. PTX directly induces TNF‐α and IL‐2 mRNA expression, modulates the level of several cell surface receptors and induces Forkhead box p3 (Foxp3) protein accumulation in naive CD4+ T cells. Addition of autologous dendritic cells was found to be required for the production of high levels of IFN‐γ by PTX‐stimulated naive T cells. These effects of PTX occurred in conjunction with activation of NF‐κB and NFAT transcription factors. Overall, responses of neonatal CD4+ T cells to PTX were similar to those of adult CD45RA+CD4+ naive T cells except for their blunted CD40 ligand up‐regulation. We suggest that the adjuvant properties of PTX during primary cell‐mediated immune responses involve a direct action on naive T lymphocytes in addition to activation of antigen‐presenting cells.
B*2707 differs in peptide specificity from B*2705 and B*2704 as much as from HLA‐B27 subtypes not associated to spondyloarthritis
Authors: Gómez Patricia , Montserrat Verónica , Marcilla Miguel , Paradela Alberto , de Castro José A. López
Published: June 2006

HLA‐B*2707 is associated with ankylosing spondylitis in most populations. Like the non‐associated allotypes B*2706 and B*2709, it lacks Asp116 and shows preference for peptides with nonpolar C‐terminal residues. The relationships between the peptide specificity of B*2707 and those of the disease‐associated B*2705 and the non‐associated subtypes were analyzed by determining the overlap between the corresponding peptide repertoires, the sequence of shared and differential ligands, and by comparing allospecific T cell epitopes with peptide sharing. The B*2707‐bound repertoire was as different from that of B*2705 as from those of B*2706, B*2709, or the two latter subtypes from each other. Differences between B*2707 and B*2705 were based on their C‐terminal residue specificity and a subtle modulation at other positions. Differential usage of secondary anchor residues explained the disparity between the B*2707‐, B*2706‐, and B*2709‐bound repertoires. Similar differences in residue usage were found between B*2707 and both B*2704 and B*2706, as expected from the high peptide overlap between the two latter subtypes. T cell cross‐reaction paralleled peptide sharing, suggesting that many shared ligands conserve their alloantigenic features on distinct subtypes. Our results indicate that association of HLA‐B27 subtypes with ankylosing spondylitis does not correlate with higher peptide sharing among disease‐associated subtypes or with obvious peptide motifs.
Evidence for the opposing roles of different γδ T cell subsets in macrophage homeostasis
Authors: Tramonti Daniela , Andrew Elizabeth M. , Rhodes Kate , Newton Darren J. , Carding Simon R.
Published: June 2006

To ensure invading pathogens are eliminated with minimal damage to host tissues it is essential that macrophage activation be tightly regulated. Previously we demonstrated that a subset of γδ T cells (Vγ1+) contributes to resolving pathogen‐induced immune responses by killing activated macrophages. However, the exaggerated macrophage response seen in infected Vγ1+ T cell‐deficient mice suggests that γδ T cells play a broader role in macrophage homeostasis and other subsets might promote macrophage activation. Using a macrophage:γδ T cell co‐culture system we have shown that γδ T cells increase the activity of macrophages activated in vivo by Listeria monocytogenes infection. In a dose‐dependent manner, γδ T cells up‐regulated production of cytokines (TNF‐α, IL‐6, IL‐10) and chemokines (MIP‐1α, MIP‐1β) by Listeria‐elicited macrophages. The ability to increase macrophage cytokine production was prominent among Vγ4+ γδ T cells. Reciprocally, Vγ4+ γδ T cells were activated by Listeria‐elicited macrophages, resulting in production of the anti‐inflammatory cytokine, IL‐10. γδ T cell adoptive transfer experiments showed that Vγ4+ T cells protected TCRδ–/– mice against Listeria‐induced liver injury and necrosis. These findings identify distinct and non‐overlapping roles for γδ T cell subsets in regulating macrophage function during pathogen‐induced immune responses.
Novel Synthetic Strategy Towards Taxol by Macrocyclization Reaction – Conformational Requirement of Ring A
Authors: Canesi Sylvain , Berthiaume Gilles , Deslongchamps Pierre
Published: June 2006

The synthesis of a completely substituted ring A of Taxol is reported and it is shown that the C13‐OP group must have a β configuration to succeed in the formation of 12‐membered rings, a requisite for the construction of the B and C rings of Taxol by a macrocyclization step. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Outage probability in multiple antenna systems
Authors: Jorswieck Eduard A. , Boche Holger
Published: June 2006

Multiple transmit antennas improve the ergodic and outage capacity of wireless systems. Spatial properties of the channel including the transmit antenna array affect the optimum transmission strategy as well as the achievable capacity and average throughput. First, we study the outage probability of a multiple input single output (MISO) system with perfect channel state information (CSI) at the receiver under different types of CSI at transmitter and with transmit antenna correlation. We prove the conjecture given in Telatar's seminal paper and complete the analysis of the optimum transmit strategy without CSI at the transmitter and uncorrelated antennas. Furthermore, we show how the impact of correlation on the outage probability depends on the transmission rate and SNR. We show that the behaviour of the outage probability differs from the behaviour of the ergodic capacity. In terms of ergodic capacity there are clear instructions what is the optimum transmission strategy and what is the impact of correlation. In contrast, the outage probability behaves chameleonic. If the transmitter is aware of the channel correlation matrices, the optimum transmit strategy is to transmit along the eigenvectors of the known correlation matrix. The remaining power allocation problem is difficult since it is a non‐convex optimisation problem. However, necessary conditions characterise the optimal allocation. Finally, we analyse the outage probability for the general multiple input multiple output (MIMO) system with spatially correlated transmit and receive antennas in asymptotic high and low SNR regime. The theoretical results are illustrated by numerical simulations. Copyright © 2005 AEIT.
Extension of domain‐free discretization method to simulate compressible flows over fixed and moving bodies
Authors: Zhou C. H. , Shu C. , Wu Y. Z.
Published: June 2006

This paper is the first endeavour to present the local domain‐free discretization (DFD) method for the solution of compressible Navier–Stokes/Euler equations in conservative form. The discretization strategy of DFD is that for any complex geometry, there is no need to introduce coordinate transformation and the discrete form of governing equations at an interior point may involve some points outside the solution domain. The functional values at the exterior dependent points are updated at each time step to impose the wall boundary condition by the approximate form of solution near the boundary. Some points inside the solution domain are constructed for the approximate form of solution, and the flow variables at constructed points are evaluated by the linear interpolation on triangles. The numerical schemes used in DFD are the finite element Galerkin method for spatial discretization and the dual‐time scheme for temporal discretization. Some numerical results of compressible flows over fixed and moving bodies are presented to validate the local DFD method. Copyright © 2006 John Wiley & Sons, Ltd.
Pseudo‐characteristic formulation and dynamic boundary conditions for computational aeroacoustics
Authors: Lu Shang‐Yi , Sagaut Pierre
Published: June 2006

The present paper deals with the use of the pseudo‐characteristic formulation of the Navier–Stokes and Euler equations recently introduced by Sesterhenn (Comput. Fluid. 2001; 30:37–67) for the simulation of acoustic wave propagation. The emphasis is put on the formulation of an efficient method on structured curvilinear grids, along with the definition and implementation of efficient boundary conditions. The cases of inflow, outflow, rigid/compliant walls and walls with prescribed impedance are addressed. The proposed boundary conditions are assessed on generic cases. The pseudo‐characteristic formulation enables a straightforward and optimal use of high‐order upwind dispersion‐relation‐preserving schemes, yielding an efficient method. Copyright © 2006 John Wiley & Sons, Ltd.
Parallel solution of lifting rotors in hover and forward flight
Authors: Allen C. B.
Published: June 2006

An implicit unsteady, multiblock, multigrid, upwind solver including mesh deformation capability, and structured multiblock grid generator, are presented and applied to lifting rotors in both hover and forward flight. To allow the use of very fine meshes and, hence, better representation of the flow physics, a parallel version of the code has been developed. It is demonstrated that once the grid density is sufficient to capture enough turns of the tip vortices, hover exhibits oscillatory behaviour of the wake, even using a steady formulation. An unsteady simulation is then presented, and detailed analysis of the time‐accurate wake history is performed and compared to theoretical predictions. Forward flight simulations are also presented and, again, grid density effects on the wake formation investigated. Parallel performance of the code using up to 1024 CPU's is also presented. Copyright © 2006 John Wiley & Sons, Ltd.
A theoretical framework for TTO valuations of health
Authors: Buckingham Ken , Devlin Nancy
Published: June 2006

This paper proposes a theoretical framework, drawing on Hicks utility theory, for the Time Trade‐off (TTO) method conventionally used to value health states. We briefly describe that theory and posit four distinctive TTO valuation approaches suggested by it: each of compensating variation and equivalent variation for both gains and losses in health, with valuation of health states in each case derived from trade‐offs between health and length of life. Recent developments and research on TTO valuation are placed in the context of this framework. Copyright © 2006 John Wiley & Sons, Ltd.
Informing the efficient use of health care and health care research resources ‐ the case of screening for abdominal aortic aneurysm in Sweden
Authors: Henriksson Martin , Lundgren Fredrik , Carlsson Per
Published: June 2006

Background: An analytical framework using Bayesian decision theory and value‐of‐information analysis has recently been advocated for the economic evaluation of health technologies. The purpose of this study was to apply this framework to screening for abdominal aortic aneurysm (AAA) in Sweden and to compare the conclusions from this study with the conclusions presented in an assessment performed by the Swedish Council of Technology Assessment (SBU).

Methods: A probabilistic decision‐analytical model was developed to establish the cost–effectiveness of a screening programme for AAA relative to current clinical practice and to calculate the value‐of‐information.

Results: The cost per quality‐adjusted life‐year for screening was €9700. The expected value of perfect information for the assessment of overall cost–effectiveness was low, suggesting little benefit in conducting further research. Expected value of perfect partial information indicated that rupture probabilities were associated with the highest uncertainty. By contrast, the SBU report concluded there was limited evidence of cost–effectiveness and proposed further research.

Conclusion: The investigated screening programme for AAA is likely to be cost–effective and conducting another clinical trial is unlikely to add much valuable information to this decision problem. These recommendations contrast with the vaguer recommendations from SBU that more evidence is required of costs–effectiveness. Copyright © 2006 John Wiley & Sons, Ltd.
Dynamic MR perfusion and proton MR spectroscopic imaging in sturge‐weber syndrome: Correlation with neurological symptoms
Authors: Lin Doris D.M. , Barker Peter B. , Hatfield Laura A. , Comi Anne M.
Published: June 2006

Purpose

To investigate physiological alterations in Sturge‐Weber syndrome (SWS) using MR perfusion imaging (PWI) and proton spectroscopic imaging (MRSI), and their association with neurological status.

Materials and Methods

Six consecutive patients with a clinically established diagnosis of SWS underwent MRI using a 1.5 Tesla scanner. The protocol consisted of conventional anatomic scans, dynamic PWI, and multislice MRSI. A pediatric neurologist evaluated the neurological scores, and the imaging results were correlated with neurological scores using nonparametric correlation analysis.

Results

Two patients had classic neuroimaging findings of unilateral cerebral atrophy with corresponding leptomeningeal enhancement and hypoperfusion (prolonged mean transit time). Two patients had bilateral disease, and two had normal symmetric perfusion. Among clinical measures, the highest correlation was between hemiparesis index and hypoperfused tissue volume (Spearman's correlation coefficient, ρ = 0.943, P < 0.05). There was also a trend of correlation, although not statistically significant (P = 0.06), between the hemiparesis score and the NAA/Cr ratio in the mid to posterior centrum semiovale, lateral gray matter (GM), and splenium.

Conclusion

In SWS, PWI indicates cerebral hypoperfusion predominantly due to impaired venous drainage, with only the most severely affected regions in some patients also showing arterial perfusion deficiency. The extent and severity of the perfusion abnormality and neuronal loss/dysfunction reflect the severity of neurological symptoms and disability, and the highest correlation is found with the degree of hemiparesis. These parameters may be useful as quantitative measures of disease burden; however, further studies in larger number of patients (and with a more homogeneous age range) are required to confirm the preliminary findings reported here. J. Magn. Reson. Imaging 2006. © 2006 Wiley‐Liss, Inc.
Sodium Hydride/Trialkylaluminum Complexes for the Controlled Anionic Polymerization of Styrene at High Temperature
Authors: Carlotti Stéphane , Menoret Stephane , Desbois Philippe , Nissner Norbert , Warzelhan Volker , Deffieux Alain
Published: June 2006

Summary: A new generation of anionic initiators (butyllithium free), based on trialkylaluminum and a readily available alkali metal hydride, has been developed for the control of styrene polymerization at high temperature. Triisobutylaluminum and sodium hydride form heterocomplexes that are efficient for the initiation of styrene polymerization at 100 °C in toluene or in bulk. To be active under such conditions, these systems require the presence of an excess of metal hydride with respect to AlR3 ([Al]/[Na] < 1). PS chains are specifically initiated by the hydrides coming from NaH, and molar masses are controlled in the range 0.8 < [Al]/[Na] < 1. Fast exchange between dormant 1:1 and active 1:2 complexes (Al:Na), and ligand rearrangements within the 1:2 complex, can explain the observed results.

Initiation of styrene with i‐Bu3Al/NaH systems.

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Initiation of styrene with i‐Bu3Al/NaH systems.
Facile polyester surface functionalization via hydrolysis and cell‐recognizing peptide attachment
Authors: Sun Hui , Önneby Sara
Published: June 2006

Facile surface modification of biodegradable polycaprolactone via alkali hydrolysis and subsequent attachment of a cell‐recognizing peptide to the hydrolysed polymer surface is reported. Surface hydrolysis was carried out in sodium hydroxide solution. The modification was studied with regard to hydrolysis time, temperature and alkaline concentration. A cell‐recognizing peptide was covalently attached to the hydrolysed polymer surface. Contact angle measurements, X‐ray photoelectron spectroscopy and ultraviolet spectroscopy were used to characterize the modified surface and to confirm the occurrence of the coupling reaction. Copyright © 2006 Society of Chemical Industry
Dietary intervention and oxidative phosphorylation capacity
Authors: Morava Eva , Rodenburg Richard , van Essen Heidi Zweers , De Vries Maaike , Smeitink Jan
Published: June 2006

Secondary deterioration of mitochondrial function has been reported in patients with anorexia and cancer‐related malnutrition. Inadequate nutrition, failure to thrive and feeding problems are also common symptoms in children with primary oxidative phosphorylation defects. As a standard intervention protocol we advise an age‐appropriate diet and energy intake in our patients diagnosed with a mitochondrial dysfunction. By comparing the results of the first and the second samples from a group of children who underwent repeated muscle biopsies, we observed biochemical improvement in the mitochondrial function in 7 out of 10 patients following dietary advice and intervention. We suggest evaluating the nutritional state by interpretation of the skeletal muscle biochemistry in patients with a suspected oxidative phosphorylation defect. Since an insufficient dietary intake could play a role in secondary mitochondrial dysfunction, nutritional intervention should be performed prior to the biopsy. On the other hand, our data suggest that optimizing the nutritional and energy intake might also improve the utilization of the residual mitochondrial energy‐generating capacity in patients with primary oxidative phosphorylation defects.
The effects of multiple ancestral residues on the Thermus thermophilus 3‐isopropylmalate dehydrogenase
Authors: Watanabe Keiko , Yamagishi Akihiko
Published: June 2006

Previously, we showed that mutants of Thermus thermophilus 3‐isopropylmalate dehydrogenase (IPMDH) each containing a residue (ancestral residue) that had been predicted to exist in a postulated common ancestor protein often have greater thermal stabilities than does the contemporary wild‐type enzyme. In this study, the combined effects of multiple ancestral residues were analyzed. Two mutants, containing multiple mutations, Sup3mut (Val181Thr/Pro324Thr/Ala335Glu) and Sup4mut (Leu134Asn/Val181Thr/Pro324Thr/Ala335Glu) were constructed and show greater thermal stabilities than the wild‐type and single‐point mutant IPMDHs do. Most of the mutants have similar or improved catalytic efficiencies at 70 °C when compared with the wild‐type IPMDH.
Transgression from drawing to making
Authors: Sheil Bob
Published: June 2006

Developments in computer-aided design and manufacturing are breaking down divisions between designing and making, opening up radical new opportunities for the practice of architecture.
Three‐phase equilibrium and partitioning calculations for CO2 sequestration in saline aquifers
Authors: Fuller R. C. , Prevost J. H. , Piri M.
Published: June 2006

We show how the use of appropriate variables results in a flash calculation that uses only equilibrium constraints; it is thus not necessary to solve the mass balance equations self‐consistently with the equilibrium equations. We use this implicit material balance in flash calculation. We show its advantages over the current approach that uses an explicit material balance. For the flash calculation for CO2 storage in brine aquifers, use of appropriate variables also allows us to find the dew, bubble, and precipitation points where the liquid, vapor, and solid salt phases, respectively, emerge. Our calculation includes the water content of the vapor phase, which arises from evaporation of the brine. Evaporation leads to increased brine salinity, which results in a large reduction in CO2 solubility in the salting‐out effect, and eventually in precipitation of solid salt and ultimately the disappearance of the liquid phase. The flash calculation also relies on our derivation of fugacities for H2O and CO2 in both the brine and the vapor phase.
Pore‐scale study of drainage displacement under combined capillary and gravity effects in index‐matched porous media
Authors: Ovdat Hanita , Berkowitz Brian
Published: June 2006

Fluid displacement patterns were observed in two‐ and three‐dimensional (2‐ and 3‐D), gravity‐driven drainage experiments. A nonintrusive, laser‐induced fluorescence technique, using refractive index matching between solid and fluid phases and subsequent imaging processing, enabled measurement of the flow patterns in porous media. The methodology allows visualization of 3‐D pore‐scale flow dynamics of two immiscible fluid phases in porous media at a low capillary number (Ca ≈ 10−4). Qualitative analyses indicate considerable diversity in the 2‐D and 3‐D displacement patterns of the invading fluid within and among the experimental systems. Quantitative analyses of these patterns, however, provide unique functional forms that characterize the invasion behavior of the nonwetting fluids, with clear differences in behavior between 2‐D and 3‐D systems. In particular, scaling relations are defined which describe the maximum vertical advance, volumetric fraction, total surface area (or, equivalently, the ratio of total surface area to volume), and specific surface area of the invading fluid. These findings are in excellent agreement with predictions from dynamic invasion percolation growth models, which were developed originally without consideration of buoyancy effects.
Decreased μ‐opioid receptor signalling and a reduction in calcium current density in sensory neurons from chronically morphine‐treated mice
Authors: Johnson Emma E , Chieng Billy , Napier Ian , Connor Mark
Published: June 2006

Sensory neurons are a major site of opioid analgesic action, but the effect of chronic morphine treatment (CMT) on μ‐opioid receptor function in these cells is unknown. We examined μ‐opioid receptor modulation of calcium channel currents (ICa) in small trigeminal ganglion (TG) neurons from mice chronically treated with morphine and measured changes in μ‐opioid receptor mRNA levels in whole TG.

Mice were injected subcutaneously with 300 mg kg−1 of morphine base in a slow release emulsion three times over 5 days, or with emulsion alone (vehicles). CMT mice had a significantly reduced response to the acute antinociceptive effects of 30 mg kg−1 morphine compared with controls (P=0.035).

Morphine inhibited ICa in neurons from CMT (EC50 300 nM) and vehicle (EC50 320 nM) mice with similar potency, but morphine's maximum effect was reduced from 36% inhibition in vehicle to 17% in CMT (P<0.05). Similar results were observed for the selective μ‐opioid agonist Tyr‐D‐Ala‐Gly‐N‐Me‐Phe‐Gly‐ol enkephalin (DAMGO). Inhibition of ICa by the GABAB agonist baclofen was unaffected by CMT.

In neurons from CMT mice, there were significant reductions in P/Q‐type (P=0.007) and L‐type (P=0.002) ICa density.

μ‐Opioid receptor mRNA levels were not altered by CMT.

These data demonstrate that CMT produces a significant reduction of the effectiveness of μ‐opioid agonists to inhibit ICa in TG sensory neurons, accompanied by a reduction in ICa density. Thus, adaptations in sensory neurons may mediate some of the tolerance to the antinociceptive effects of morphine that develop during systemic administration.

British Journal of Pharmacology (2006) 148, 947–955. doi:10.1038/sj.bjp.0706820
Phase separation of a binary two-dimensional core-softened fluid
Authors: Huang Zhi-Yong , Merlitz Holger , Wu Chen-Xu
Published: June 2006

Using molecular dynamics simulations, we study the phase separation in a binary two-dimensional core-softened fluid with different size ratios and concentrations. The correlation functions for both components are analyzed to show the dependence of the configurational structure of the binary fluid on size ratio and concentration. A phase separation diagram is obtained and the structural features of the phase separation are further investigated using the direct imaging method.
Aggregates of rod-coil diblock copolymers adsorbed at a surface
Authors: Nowak C. , Vilgis T. A.
Published: June 2006

The behavior of rod-coil diblock copolymers close to a surface is discussed by using extended scaling methods. The copolymers are immersed in selective solvent such that the rods are likely to aggregate to gain energy. The rods are assumed to align only parallel to each other, such that they gain a maximum energy by forming liquid crystalline structures. If an aggregate of these copolymers adsorbs with the rods parallel to the surface the rods shift with respect to each other to allow for the chains to gain entropy. It is shown that this shift decays with increasing distance from the surface. The profile of this decay away from the surface is calculated by minimization of the total free energy of the system. The stability of such an adsorbed aggregate and other possible configurations are discussed as well.
Optical properties of current carrying molecular wires
Authors: Galperin Michael , Nitzan Abraham
Published: June 2006

We consider several fundamental optical phenomena involving single molecules in biased metal-molecule-metal junctions. The molecule is represented by its highest occupied and lowest unoccupied molecular orbitals, and the analysis involves the simultaneous consideration of three coupled fluxes: the electronic current through the molecule, energy flow between the molecule and electron-hole excitations in the leads, and the incident and/or emitted photon flux. Using a unified theoretical approach based on the nonequilibrium Green’s function method we derive expressions for the absorption line shape (not an observable but a useful reference for considering yields of other optical processes) and for the current induced molecular emission in such junctions. We also consider conditions under which resonance radiation can induce electronic current in an unbiased junction. We find that current driven molecular emission and resonant light induced electronic currents in single molecule junctions can be of observable magnitude under appropriate realizable conditions. In particular, light induced current should be observed in junctions involving molecular bridges that are characterized by strong charge-transfer optical transitions. For observing current induced molecular emission we find that in addition to the familiar need to control the damping of molecular excitations into the metal substrate the phenomenon is also sensitive to the way in which the potential bias is distributed on the junction.
Predicted ultrafast single-qubit operations in semiconductor quantum dots
Authors: Pryor C. E. , Flatté M. E.
Published: June 2006

Several proposals for scalable quantum computation rely on the manipulation of the spin of individual electrons in semiconductors. We show that a spin-sensitive optical Stark effect will produce a coherent rotation of spin in quantum dots containing a single electron. The calculated magnitude of the effective magnetic field depends on the dot band gap and the strain. We predict that in InAs∕InP dots, for reasonable experimental parameters, the magnitude of the rotation is sufficient and the intrinsic error is low enough for them to serve as elements of a quantum-dot-based quantum computer.