bluuebunny/crossref_metadata_2025_split huggingface dataset:
Human plasma kinetics and metabolites of [123I]CNS‐1261 — a novel NMDA receptor radioligand for spet
Authors: Mulligan R. S. , Erlandsson K. , Bressan R. A. , Owens J. , Ell P. J. , Pike V. W. , Pilowsky L. S. 
Published: April 2012

AbstractThis study reports on the pharmacokinetics and metabolism of [123I]CNS‐1261 as part of the validation of this radioligand for imaging the activated NMDA ion channel in humans with SPET. After injection of [123I]CNS‐1261, radioactivity is cleared rapidly from plasma. Parent radioligand is metabolised to three, more polar radioactive metabolites. Arterial and venous plasma radioactivity has also been measured and compared. Arterial data is required for biomathematical modelling.
Radiosynthesis of [4‐O‐methyl‐11C]KF18446 as a potential ligand for the central adenosine a2A receptor and comparison with [4‐O‐methyl‐11C]KW6002 in rats
Authors: Turton D. R. , Hirani E. , Osman S. , Poole K. , Falokun G. , Brady F. , Karasawa A. , Shimada J. , Brooks D. J. , Hume S. , Luthra S. K. 
Published: April 2012

AbstractThe adenosine A2A antagonist, KF18446 was labelled in the aromatic O‐methyl position using [11C]iodomethane. [4‐O‐methyl‐11C]KF18446 and [4‐O‐methyl‐11C]KW‐6002, an adenosine A2A antagonist that we radiolabelled previously, were evaluated in rats. In brain, both [4‐O‐methyl‐11C]KW‐6002 and [4‐O‐methyl‐11C]KF18446 showed the highest uptake in striata and lowest in frontal cortex. For [4‐O‐methyl‐11C]KW‐6002 maximal striata: frontal cortex ratio was 1.7 from 60 to 120 min. For [4‐O‐methyl‐11C]KF18446 maximal striata: frontal cortex ratio was 2.4 from 30 to 90 min. The amount of unchanged [4‐O‐methyl‐11C]KW‐6002 was > 98 % in striata and cerebellum at 75 min post‐injection.
Significance of circulating endothelial progenitor cells in patients with fracture healing process
Authors: Ma Xin‐Long , Sun Xiao‐Lei , Wan Chun‐You , Ma Jian‐Xiong , Tian Peng 
Published: April 2012

AbstractFracture healing is a complex bone formation process, and neovascularization may contribute to new bone regeneration. The circulating endothelial progenitor cell (EPC) mobilization and homing could involve in neovascularization and vasculogenesis. In this study, we investigate the changes of circulating EPC during bone fracture healing, and the possible contribution of EPCs to increased neovascularization and fracture healing. The number of circulating EPCs was monitored in twenty‐four patients with long bone traumatic fracture within the first 48 h and at 3, 5, 10, and 14 days post‐fracture. The mononuclear cells which isolated from peripheral blood were analyzed by flow cytometry. Peripheral blood counts of leukocytes and platelets were measured by hematology analyzer. The amount of peripheral EPCs significantly increased in patients with fracture compared to age‐matched healthy control subjects within the first 48 h after injury, and peaked at 3 days post‐fracture. There was no significant difference in the change trend of early EPCs between male and female, but the number of early EPCs was significantly greater in younger patients compared to older patients. A comparison of the EPCs levels between patients with severe injury (ISS > 16) and patients with mild injury (ISS ≤ 16) revealed no statistically significant difference. The level of early EPCs was inverse correlation with the level of plate after fracture, but no correlation with the level of peripheral leucocytes. These findings suggest traumatic fracture may induce the mobilization of EPCs into the peripheral circulation. The increased EPCs may contribute to neovascularization and involve in fracture healing. © 2012 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 30:1860–1866, 2012
Effects of seeding rate, nitrogen rate and cultivar on barley malt quality
Authors: Edney Michael J , O'Donovan John T , Turkington T Kelly , Clayton George W , McKenzie Ross , Juskiw Pat , Lafond Guy P , Brandt Stewart , Grant Cynthia A , Harker K Neil , Johnson Eric , May William 
Published: April 2012

AbstractBACKGROUND:Crop management tools have been shown to affect barley kernel size and grain protein content, but the direct effect on malt quality is not well understood. The present study investigated the effect of seeding rate, nitrogen fertilisation and cultivar on malt quality.RESULTS:Higher seeding rates produced barley with less grain protein and smaller, more uniformly sized kernels. The small, uniformly sized kernels modified more completely, leading to malt with higher extract and lower wort β‐glucan than malt from low‐seeding‐rate barley. Increasing rates of nitrogen fertilisation caused grain protein levels to increase, which limited endosperm modification and reduced malt extract levels. AC Metcalfe showed better modification and higher malt extract than CDC Copeland, but CDC Copeland had better protein modification at higher fertilisation rates, which resulted in less reduction of malt extract as nitrogen rate increased.CONCLUSION:Higher seeding rates reduced kernel size and grain protein levels without compromising malt extract owing to better endosperm modification of the more uniformly sized kernels. Negative effects of higher nitrogen rates on malt quality can be reduced through development of cultivars with improved ability to modify protein during malting. © 2012 Her Majesty the Queen in Right of Canada
Naked and Self‐Clickable Propargylic‐Decorated Single‐Chain Nanoparticle Precursors via Redox‐Initiated RAFT Polymerization
Authors: Sanchez‐Sanchez Ana , Asenjo‐Sanz Isabel , Buruaga Lorea , Pomposo José A. 
Published: April 2012

AbstractProtection of acetylenic monomers is a common practice to avoid parasitic side reactions during polymerization. Herein, we report that redox‐initiated RAFT polymerization allows the direct, room temperature synthesis of a variety of single‐chain nanoparticle precursors (displaying narrow molecular weight dispersity, $\overline{M}_{\rm w}$/$\overline{M}_{\rm n}$ = 1.12 –1.37 up to $\overline{M}_{\rm w}$ = 100 kDa) containing well‐defined amounts of naked, unprotected acetylenic functional groups available for rapid and quantitative intrachain cross‐linking via metal‐catalyzed carbon–carbon coupling (i.e., C–C “click” chemistry). To illustrate the useful “self‐clickable” character of the new unprotected acetylenic precursors, single‐chain nanoparticles have been prepared for the first time in a facile and highly efficient manner by copper‐catalyzed alkyne homocoupling (i.e., Glaser–Hay coupling) at room temperature under normal air atmosphere.
Fabrication of Arrays of Polymer Gradients Using Inkjet Printing
Authors: Hansen Anne , Zhang Rong , Bradley Mark 
Published: April 2012

AbstractArrays of 84 polymer gradients, fabricated on a single glass microscope slide, were generated by inkjet printing, allowing a combination of high‐throughput and true combinatorial methods. The gradual change of composition within the polymer gradients, consisting of two different monomers and a cross‐linker, was validated by XPS and fluorescence analysis. Cellular screening of the gradients allowed the rapid identification of optimal polymer compositions for binding of the suspension cell line K562 and the adherent cell line HeLa. The polymers identified were identical to those identified by previous microarray data, providing proof of concept for the successful application of the polymer gradient arrays as a screening tool. In addition, the polymer gradients could be readily modified by conjugation enabling the generation of bio‐molecule gradients.
Highly undersampled phase‐contrast flow measurements using compartment‐based k–t principal component analysis
Authors: Giese Daniel , Schaeffter Tobias , Kozerke Sebastian 
Published: April 2012

AbstractThe applicability of cine blood flow measurements in a clinical setting is often compromised by the long scan times associated with phase‐contrast imaging. In this work, we propose an extension to the k–t principal component analysis method and demonstrate that by definition of spatial compartment‐dependent temporal basis functions, significant improvements in reconstruction accuracy can be achieved relative to the original k–t principal component analysis and k–t SENSE formulations. Using this method, it is shown that prospective nominal undersampling of up to 16 corresponding to a net acceleration factor of 8 including training data acquisition can be realized while keeping the error in stroke volume below 5%. As a practical application, the acquisition of cine flow data in the aorta is demonstrated permitting assessment of two‐dimensional velocity images and pulse wave velocities at 100 frames per second in a single breathhold per slice. Magn Reson Med, 2013. © 2012 Wiley Periodicals, Inc.
Improved partial volume correction for single inversion time arterial spin labeling data
Authors: Liang Xiaoyun , Connelly Alan , Calamante Fernando 
Published: April 2012

AbstractArterial spin labeling has relatively low spatial resolution, which affects cerebral blood flow measurements by partial volume effect occurring at tissue interfaces, e.g., between gray matter, white matter, and cerebrospinal fluid. This can be an important source of cerebral blood flow quantification error. To correct for partial volume effect in arterial spin labeling, a linear regression method was recently proposed. Because this method assumes that tissue magnetization and cerebral blood flow are constant over an n2 × 1 regression kernel, an inherent spatial blurring is introduced. In this study, a modified least trimmed squares algorithm is proposed for partial volume effect correction. It is demonstrated using simulations that the modified least trimmed square method can correct for partial volume effect and produce less blurring than the linear regression method. This is achieved without either acquiring additional datasets or increasing the computation burden. These capabilities were further demonstrated in vivo. The modified least trimmed square method should, therefore, play an important role in arterial spin labeling studies. Magn Reson Med, 2013. © 2012 Wiley Periodicals, Inc.
Measurement of vibration‐induced volumetric strain in the human lung
Authors: Hirsch Sebastian , Posnansky Oleg , Papazoglou Sebastian , Elgeti Thomas , Braun Jürgen , Sack Ingolf 
Published: April 2012

AbstractNoninvasive image‐based measurement of intrinsic tissue pressure is of great interest in the diagnosis and characterization of diseases. Therefore, we propose to exploit the capability of phase‐contrast MRI to measure three‐dimensional vector fields of tissue motion for deriving volumetric strain induced by external vibration. Volumetric strain as given by the divergence of mechanical displacement fields is related to tissue compressibility and is thus sensitive to the state of tissue pressure. This principle is demonstrated by the measurement of three‐dimensional vector fields of 50‐Hz oscillations in a compressible agarose phantom and in the lungs of nine healthy volunteers. In the phantom, the magnitude of the oscillating divergence increased by about 400% with 4.8 bar excess air pressure, corresponding to an effective‐medium compression modulus of 230 MPa. In lungs, the averaged divergence magnitude increased in all volunteers (N = 9) between 7 and 78% from expiration to inspiration. Measuring volumetric strain by MRI provides a compression‐sensitive parameter of tissue mechanics, which varies with the respiratory state in the lungs. In future clinical applications for diagnosis and characterization of lung emphysema, fibrosis, or cancer, divergence‐sensitive MRI may serve as a noninvasive marker sensitive to disease‐related alterations of regional elastic recoil pressure in the lungs. Magn Reson Med, 2013. © 2012 Wiley Periodicals, Inc.
Effects of plasma treatment on greenhouse polyethylene cover aged under sub‐Saharan conditions
Authors: Dobbi Abdelmadjid , Bouabdallah Ahcene , Bouchama Mohamed , Meghoufel Faiza Zahira , Hassini Noureddine 
Published: April 2012

AbstractThe effects of natural ageing, in sub‐Saharan regions, on treated low density polyethylene by cold plasma are presented in this work. The data analysis is performed by comparing the changes of physical, mechanical and structural effects on the material surface induced by plasma treatment with regard to the natural abrasion effect due to sand wind. Plasma treatments for short durations are applied to neutral LDPE (low density polyethylene) films. Few seconds suffice to observe chemical changes on the samples. The treated samples are then subjected to natural ageing in the region of Ouargla (south of Algeria), characterized by very frequent sand wind. The characterization of the effects of plasma treatment and its combination with sand wind is performed using XPS (X‐ray Photoelectron Spectroscopy), FTIR (Fourier Transform Infrared spectrometry), and mechanical tensile testing. The results led to conclude a synthesis of new materials on the surface that significantly change the material surface properties and physico‐chemical properties of material, more particularly, optical, and mechanical properties are thus strongly affected. POLYM. ENG. SCI., 2012. © 2012 Society of Plastics Engineers
Electrochemically induced charge transfer in platinum–silicon heterosystems
Authors: Bürstel Damian , Diesing Detlef 
Published: April 2012

AbstractElectrochemical cyclovoltammetry experiments were carried out on the platinum surface of a platinum–silicon thin‐film device in sulfuric acid. The internal electronic barrier of the device allows the separation of ground state and excited state charge transfer events released by the electrochemical surface reaction. The traces of the device current show similar features as the cyclovoltammogram and can be discussed in terms of small deviations from the equilibrium state of the thin platinum film. The device current plotted as a function of the electrode potential shows a well‐defined shift of the baseline when hydrogen is adsorbed. This baseline shift may be originated by an adsorbate‐induced change of the chemical potential of the platinum film, thus influencing the internal field in the device (up to values of 23 mV).magnified imagePlot of the electrochemical current and the device current as functions of the electrode potential.
Defect levels in SnS thin films prepared using chemical spray pyrolysis
Authors: Sajeesh T. H. , Jinesh K. B. , Rao M. , Kartha C. S. , Vijayakumar K. P. 
Published: April 2012

AbstractThe origin of various defect levels in the SnS thin films deposited using chemical spray pyrolysis (CSP) technique has been explored in this manuscript, by employing low‐temperature photoluminescence (PL) technique. Concentration of Sn in the samples was varied purposefully by ex situ diffusion in order to alter the defect levels. The acceptor level obtained at 0.22 eV from the Arrhenius plot, has been assigned as the defect level caused by the Sn vacancies present in the lattice. Two shallow donor levels are conclusively identified and their activation energies have been estimated. The present study could also unearth a trap level in the forbidden energy gap which was due to the oxygen contaminant occupied by the vacancy of Sn. This trap level could be removed by annealing the sample in vacuum or through the ex situ diffusion of Sn. Employing Kelvin probe force microscopy (KPFM), the work‐function of SnS was obtained as 4.925 eV, from which the position of the Fermi level could be assigned. Based on the present work, an energy level scheme for SnS thin films is proposed outlying origin of various defect levels.
Resonant Raman study of dye instability in dye‐sensitized TiO2 system: The effect of surface states
Authors: Wu Kunjie , Shen Kai , Liu Weifeng , Wu Liuer , Wang Deliang 
Published: April 2012

AbstractThe most critical problem in commercialization of the dye‐sensitized solar cell (DSSC) is its long‐term stability. Many factors contribute to the instability of a DSSC. In order to clarify the role of the surface defects on the cell instability, we modified the TiO2 surface chemical states, fabricated DSSCs with a very simple structure, and carried out resonant Raman scattering to monitor the dye degradation under open‐circuit condition. The results showed that the dye stability was very sensitive to the TiO2 surface states. The dye degradation can be described by an exponential decay law. The oxygen vacancy–Ti3+ chemical state enhanced the recombination of electron with the oxidized electrolyte, i.e., the electron in the TiO2 conduction band injected back to the electrolyte, and consequently enhanced the dye regeneration rate by I−, which came from the reduction of ${\rm I}_{3}^{- } $ with electrons. Under the open‐circuit condition the dye stability was increased when it was attached to a TiO2 surface with a relatively high percentage of oxygen vacancy–Ti3+ chemical state. The increased electron recombination occurred at the TiO2/electrolyte interface resulted in a much decreased open‐circuit voltage and short‐circuit current in a DSSC.
Parasitic absorption effect of metal nanoparticles in the dye‐sensitized solar cells
Authors: Yuan Li , Chen Fuyi , Zheng Chunfeng , Liu Jian , Alemu Negash 
Published: April 2012

AbstractThe parasitic absorption effect of metal nanoparticles in the dye‐sensitized solar cells (DSSC) was investigated using the finite difference time domain technique. It was shown that the conversion efficiency can be improved up to 15–20% in the DSSC device with an optimized metal nanoparticle array of 210 nm in diameter and 500 nm in period, but even under the optimized conditions, the absorption of metal nanoparticles take up about 20–30% of the total absorption of DSSC at visible wavelengths. The heat loss of smaller (70 nm) metal nanoparticles at visible light wavelengths is far greater than the electromagnetic energy scattered into the optical active dye‐sensitized medium. The possible direction was proposed to solve the metal parasitic absorption problem.
Electroluminescence from amorphous silicon/crystalline silicon solar cells and its temperature dependence
Authors: Brüggemann Rudolf 
Published: April 2012

AbstractThe quality of the amorphous silicon/crystalline silicon interface is decisive for efficient operation of amorphous silicon/crystalline silicon heterojunction solar cells. We investigate the electroluminescence from these heterojunction solar cells for a variation of interface properties. We detail electroluminescence results from temperature‐dependent simulations which show that the electroluminescence yield at constant current density is almost temperature‐independent for lower interface‐defect densities while for higher interface‐defect densities the electroluminescence yield decreases with decreasing temperature. In contrast to the influence of the front interface which does not change the spectral shape, the related inhomogeneous carrier profile distorts the spectrum so that conclusions can be drawn on the rear interface properties. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Shell model for REOx nanoclusters in amorphous SiO2: charge trapping and electroluminescence quenching
Authors: Tiagulskyi S. , Nazarov A. , Tyagulskii I. , Lysenko V. , Rebohle L. , Lehmann J. , Skorupa W. 
Published: April 2012

AbstractIn this work charge trapping and electroluminescence (EL) quenching in rare‐earth (RE) implanted SiO2 on Si as a function of injected charge into the dielectric were studied. The blocking of the luminescent REOX nanoclusters from the hot exciting electrons by negative charge trapping in a defect region (shell) located in the vicinity of the REOX nanocluster/SiO2 interface is considered as the main mechanism of EL quenching for small size (up to 10 nm) REOX nanoclusters. It is suggested that the increase of the nanoclusters size results in disordering of the SiO2 matrix but in a decrease of local blocking for excitation of the luminescent centers. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Correlation of nanostructure and charge transport properties of oxidized a ‐SiC:H films
Authors: Gordienko S. O. , Nazarov A. N. , Vasin A. V. , Rusavsky A. V. , Lysenko V. S. 
Published: April 2012

AbstractThis paper considers the influence of low temperature oxidation on structural and electrical properties of amorphous carbon‐rich a ‐Si1‐xCx:H thin films fabricated by reactive RF magnetron sputtering. It is shown that oxidation leads to formation of SiOx matrix with graphite‐like carbon inclusions. Such conductive precipitates has a strong effect on charge transport in oxidized a ‐Si1‐xCx:H films (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Percolation effect in structures with amorphous and crystalline silicon nanoclusters
Authors: Zhigunov Denis M. , Emelyanov Andrey V. , Timoshenko Victor Yu. , Sokolov Victor I. , Seminogov Vladimir N. 
Published: April 2012

AbstractIn this paper the correlations between optical, electrical and structural properties of ensembles of amorphous and crystalline silicon nanoclusters in silicon oxide matrix are explained in terms of percolation theory. SiOx (1 ≤ x < 2) thin films were deposited on silicon or quartz substrates by reactive evaporation of SiO powder and were subsequently thermally annealed at temperatures in the range from 450 to 1200 °C. Five sets of samples with different stoichiometry parameters x = 1.0, 1.1, 1.29, 1.56, 1.68 of initial SiOx were fabricated. The volume fraction of total excess silicon as well as the volume fraction of silicon nanocrystals in high temperature annealed structures are calculated for each sample set. It is found that samples with excess Si volume fraction of more than 16% (which is critical value in percolation theory) demonstrate a local maximum at about 500‐600 °C in the dependence of integrated photoluminescence intensity on annealing temperature, which is attributed to the first percolation threshold in the system of amorphous Si nanoclusters. In turn, the second percolation threshold is detected in the system of crystalline Si nanoclusters, when their volume fraction exceeds 16%. Such effect, resulted in dramatic increase of the electrical conductance of SiOx film, was registered experimentally for the set of samples with x = 1.0. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
An analysis of the diurnal cycle of precipitation over Dakar using local rain‐gauge data and a general circulation model
Authors: Sane Y. , Bonazzola M. , Rio C. , Chambon P. , Fiolleau T. , Musat I. , Hourdin F. , Roca R. , Grandpeix J.‐Y. , Diedhiou A. 
Published: April 2012

AbstractThe representation of the diurnal cycle of local deep convection in two versions of the Laboratoire de Météorologie Dynamique–Zoom (LMDZ) General Circulation Model is evaluated using rainfall observations of a rain‐gauge network in Senegal. An interpretation of the observed rainfall diurnal modes is attempted by partitioning rainfall as a function of rain‐rate intensities and the origin, age and size of associated cloud systems. Our analysis shows a complex multipeak diurnal cycle and a large spatial variability over the rain‐gauge domain of typically 100 km. Our results are consistent with the picture of a diurnal cycle of high convective rain rates associated with young and small cloud systems generated in the vicinity of the rain gauges, peaking in late afternoon and superimposed with precipitation associated with long propagative mesoscale convective systems or squall lines with no preferential time over the rain‐gauge network. It is shown that these local observations of convection and rain can be used to evaluate the representation of the diurnal cycle of precipitation in a general circulation model with a typical horizontal resolution of 100 km. Two versions of the LMDZ model, including different parametrizations of boundary‐layer turbulence, convection and clouds, are compared with observations. In the new parametrization, considering the role of boundary‐layer thermals in deep convection preconditioning and the role of cold pools in its sustainment allows us realistically to shift the maximum of precipitation and cloud cover to late afternoon. Copyright © 2012 Royal Meteorological Society