bluuebunny/crossref_metadata_2025_split huggingface dataset:
The MRI‐measured arterial input function resulting from a bolus injection of Gd‐DTPA in a rat model of stroke slightly underestimates that of Gd‐[14C]DTPA and marginally overestimates the blood‐to‐brain influx rate constant determined by Patlak plots
Authors: Nagaraja Tavarekere N. , Karki Kishor , Ewing James R. , Divine George W. , Fenstermacher Joseph D. , Patlak Clifford S. , Knight Robert A. 
Published: May 2010

AbstractThe hypothesis that the arterial input function (AIF) of gadolinium‐diethylenetriaminepentaacetic acid injected by intravenous bolus and measured by the change in the T1‐relaxation rate (ΔR1; R1 = 1/T1) of superior sagittal sinus blood (AIF‐I) approximates the AIF of 14C‐labeled gadolinium‐diethylenetriaminepentaacetic acid measured in arterial blood (reference AIF) was tested in a rat stroke model (n = 13). Contrary to the hypothesis, the initial part of the ΔR1‐time curve was underestimated, and the area under the normalized curve for AIF‐I was about 15% lower than that for the reference AIF. Hypothetical AIFs for gadolinium‐diethylenetriaminepentaacetic acid were derived from the reference AIF values and averaged to obtain a cohort‐averaged AIF. Influx rate constants (Ki) and proton distribution volumes at zero time (Vp + Vo) were estimated with Patlak plots of AIF‐I, hypothetical AIFs, and cohort‐averaged AIFs and tissue ΔR1 data. For the regions of interest, the Kis estimated with AIF‐I were slightly but not significantly higher than those obtained with hypothetical AIFs and cohort‐averaged AIF. In contrast, Vp + Vo was significantly higher when calculated with AIF‐I. Similar estimates of Ki and Vp + Vo were obtained with hypothetical AIFs and cohort‐averaged AIF. In summary, AIF‐I underestimated the reference AIF; this shortcoming had little effect on the Ki calculated by Patlak plot but produced a significant overestimation of Vp + Vo. Magn Reson Med 63:1502–1509, 2010. © 2010 Wiley‐Liss, Inc.
Accelerating time‐resolved MRA with multiecho acquisition
Authors: Jeong Hyun J. , Eddleman Christopher S. , Shah Saurabh , Seiberlich Nicole , Griswold Mark A. , Batjer H. Hunt , Carr James C. , Carroll Timothy J. 
Published: May 2010

AbstractA new four‐dimensional magnetic resonance angiograpy (MRA) technique called contrast‐enhanced angiography with multiecho and radial k‐space is introduced, which accelerates the acquisition using multiecho while maintaining a high spatial resolution and increasing the signal‐to‐noise ratio (SNR). An acceleration factor of approximately 2 is achieved without parallel imaging or undersampling by multiecho (i.e., echo‐planar imaging) acquisition. SNR is gained from (1) longer pulse repetition times, which allow more time for T1 regrowth; (2) decreased specific absorption rate, which allows use of flip angles that maximize contrast at high field; and (3) minimized effects of a transient contrast bolus signal with a shorter temporal footprint. Simulations, phantom studies, and in vivo scans were performed. Contrast‐enhanced angiography with multiecho and radial k‐space can be combined with parallel imaging techniques such as Generalized Autocalibrating Partially Parallel Acquisitions (GRAPPA) to provide additional 2‐fold acceleration in addition to higher SNR to trade off for parallel imaging. This technique can be useful in diagnosing vascular lesions where accurate dynamic information is necessary. Magn Reson Med 63:1520–1528, 2010. © 2010 Wiley‐Liss, Inc.
Nonlinear inverse reconstruction for real‐time MRI of the human heart using undersampled radial FLASH
Authors: Uecker Martin , Zhang Shuo , Frahm Jens 
Published: May 2010

AbstractA previously proposed nonlinear inverse reconstruction for autocalibrated parallel imaging simultaneously estimates coil sensitivities and image content. This work exploits this property for real‐time MRI, where coil sensitivities need to be dynamically adapted to the conditions generated by moving objects. The development comprises (i) an extension of the nonlinear inverse algorithm to non‐Cartesian k‐space encodings, (ii) its implementation on a graphical processing unit to reduce reconstruction times, and (iii) the use of a convolution‐based iteration, which considerably simplifies the graphical processing unit implementation compared to a gridding technique. The method is validated for real‐time MRI of the human heart at 3 T using radio frequency‐spoiled radial FLASH (pulse repetition time/echo time = 2.0/1.3 ms, flip angle 8°). The results demonstrate artifact‐free reconstructions from only 65–85 spokes, with 256 oversampled data points. Acquisition times of 130–170 ms resulted in 29–38 frames per second for sliding window reconstructions (factor 5). While offline reconstructions required 1–2 sec, real‐time applications with modified parameters and slightly lower image quality were achieved within 90 ms per graphical processing unit. Magn Reson Med 63:1456–1462, 2010. © 2010 Wiley‐Liss, Inc.
Modification of acrylonitrile/acrylic acid copolymer films and fibers by dendrigraft formation
Authors: Akbari Somaye , Kish Mohammad H , Entezami Ali A 
Published: May 2010

AbstractSamples of film, wet‐ and electro‐spun fibers and powder were prepared from acrylonitrile/acrylic acid copolymer, with their specific surface areas being considerably different. We attempted to alter the properties of the samples by increasing the amount of carboxylic acid groups on the surfaces through the formation of dendritic structures. Dendritic molecules were grown by a reaction between the carboxylic acid groups of acrylic acid, activated by dicyclohexylcarbodiimide, and hydroxyl groups of citric acid. Products were analyzed using Fourier transform infrared and NMR spectroscopy, optical microscopy, scanning electron microscopy and density measurements. It was found that with an increase of the specific surface area, the percentage conversion increased indicating that the topochemical reactions were prominent. The density of electro‐spun fibers was the greatest indicating the most compact structure. With an increase of step numbers of dendrigraft formation the density reached a minimum which points to the formation of nanoscale voids in the deposited dendritic structure. Copyright © 2010 Society of Chemical Industry
HVPE GaN substrates: growth and characterization
Authors: Gogova D. , Siche D. , Kwasniewski A. , Schmidbauer M. , Fornari R. , Hemmingsson C. , Yakimova R. , Monemar B. 
Published: May 2010

AbstractGaN substrates with low dislocation densities were prepared by halide vapor‐phase epitaxy (HVPE) on c‐plane sapphire and by means of a post‐growth laser‐induced lift‐off or natural stress‐induced (self‐) separation process. The HVPE growth on InGaN/GaN buffer layers and subsequent self‐separation method was seen as advantageous, in comparison with the laser‐induced lift‐off one, in terms of lower cost and better crystalline quality of the GaN material obtained. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Cubic GaN growth on (311)A GaAs substrate by MOVPE
Authors: Sanorpim Sakuntam , Discharoen Nuttapong , Onabe Kentaro 
Published: May 2010

AbstractCubic GaN layers has been grown on (311)A GaAs substrates by MOVPE at relatively high growth temperature at 900 °C. Cubic GaN (311) grew on the (311)A GaAs with and in‐plane epitaxial relationship of [01‐1]GaN//[01‐1]GaAs and [200]GaN//[200]GaAs. Full width at half maximum of the cubic GaN (002) X‐ray rocking curve is less than 20 arc min, which is comparable to that of the cubic GaN grown on (001) substrate. The lattice constant is in the range of 4.502 to 4.506 Å. Even at the growth temperature as high as 900 °C, the interface between cubic GaN layer and GaAs substrate is remarkably smooth without any voids, owing to the suppression of the (111) surface steps on the (311)A substrate surface. These results indicate that the (311)A‐oriented GaAs is a candidate substrate for the MOVPE growth of cubic GaN layer in avoiding the thermal decomposition of GaAs and in improving the interface and surface morphologies. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Angle‐resolved photoelectron spectroscopy study of the GaN(0001)‐2×2 surface
Authors: Lorenz P. , Gutt R. , Himmerlich M. , Schaefer J. A. , Krischok S. 
Published: May 2010

AbstractGaN(0001)‐2×2 surfaces were investigated by angle‐resolved ultraviolet photoelectron spectroscopy (ARUPS) as well as X‐ray photoelectron spectroscopy (XPS). Contamination‐ and metal‐free GaN thin films with a 2×2 reconstruction and a rms roughness below 1 nm were grown on 6H‐SiC(0001) by plasma assisted molecular beam epitaxy (PAMBE). The valence band structure of the surface was investigated in‐situ with ARUPS along the $ {\bar \rm \Gamma} - {\bar \rm M}$ and $ {\bar \rm \Gamma} - {\bar \rm K}$ directions of the surface Brillouin zone. Weak dispersive surface states related to the unreconstructed GaN surface or to the 2×2 superstructure as well as the dispersion of electron states of the bulk band structure are identified and compared to available results from density functional theory (DFT) calculations [Phys. Rev. B 77, 115120 (2008)] for GaN(0001). (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Fabrication of light emitting diodes transferred onto different substrates by GaN substrate separation technique
Authors: Kunoh Y. , Takeuchi K. , Inoshita K. , Ohbo H. , Tokunaga S. , Goto T. , Kunisato T. 
Published: May 2010

AbstractWe have successfully transferred GaN films grown on high crystalline quality GaN substrates onto different substrates, where we have developed a laser lift‐off technique with a green laser and an absorption‐enhanced InGaN layer as a sacrificial layer (a layer to absorb laser beams). We have also achieved an output power of 13.0 mW at 20 mA with a wavelength of approximately 410 nm and an external quantum efficiency of 21.6% for light emitting diodes transferred on Si substrates by using this method (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Theoretical investigation of the decomposition mechanism of AlN(0001) surface under a hydrogen atmosphere
Authors: Suzuki Hikari , Panyukova Uliana , Togashi Rie , Murakami Hisashi , Kumagai Yoshinao , Koukitu Akinori 
Published: May 2010

AbstractThe activation energies for Al and N desorption from an AlN surface were calculated using the density functional theory (DFT) to obtain a detailed understanding of the decomposition process of AlN(0001) Al and N surfaces under a hydrogen atmosphere. It was found that Al atoms on the AlN(0001) Al surface desorbed as AlH and formed AlH3 by reacting with two H atoms on the surface just after desorption, whereas N atoms on the AlN(0001) N surface desorbed as NH3 molecules from the surface. The desorption energy of Al on the hydrogen terminated surface was more consistent with previous experimental value than that on an ideal surface. This result suggests that the initial surface structure of the AlN(0001) surface is terminated with hydrogen. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Enhancement of initial layer‐by‐layer growth and reduction of threading dislocation density by optimized Ga pre‐irradiation in molecular‐beam epitaxy of 2H‐AlN on 6H‐SiC(0001)
Authors: Okumura Hironori , Kimoto Tsunenobu , Suda Jun 
Published: May 2010

Abstract300‐nm‐thick AlN layers without a nucleation layer were grown on 6H‐SiC (0001) vicinal substrates with 3‐bilayer‐height steps by rf‐plasma‐assisted molecular‐beam epitaxy. A Ga beam was supplied for 0 to 30 seconds just before growth of AlN. The Ga pre‐irradiation for 7 seconds (∼1.6 ML) was found to be effective for realization of the AlN layer‐by‐layer growth mode at an earlier stage of the growth and reduction of threading dislocation densities (TDD) in the AlN layers. The screw‐type and edge‐type TDDs were ∼106 cm‐2 and 6×108 cm‐2, respectively. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Light emission polarization properties of strained (11$ \bar 2 $2) semipolar InGaN quantum well
Authors: Huang Hung‐Hsun , Wu Yuh‐Renn 
Published: May 2010

AbstractWe studied the optical characteristics of a (11$ \bar 2 $2) semipolar InGaN/GaN quantum well with different indium compositions, quantum well widths, and injection carrier densities. The self‐consistent Poisson and 6×6 k · p Schrödinger solver has been applied to study the band structure in semipolar InGaN quantum well light emitting diodes. Our work shows an interesting switching behavior of the polarization direction when the indium composition is larger than 40%. The best configuration for the maximized polarization condition has been studied in this paper. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Probing nanotribological and electrical properties of organic molecular films with atomic force microscopy
Authors: Park Jeong Young , Qi Yabing 
Published: May 2010

AbstractStructural aspects of organic molecular films, such as disordering, packing density, molecular bending or tilts, and phase separation, influence electrical properties as well as friction and adhesion. This indicates a correlation between nanomechanical and charge transport properties of molecular films at the molecular scale. In this review, we highlight the recent studies on correlations between charge transport and nanomechanical properties probed with atomic force microscopy. We discuss the key issues that determine charge transport and nanomechanical properties on several organic molecular films, including self‐assembled monolayers formed by saturated hydrocarbon molecules conjugated molecules, and hybrid molecules as well as polymer and polymer blend films. We address the role of molecular deformation and bending in friction and conductance measurements. SCANNING 32: 257–264, 2010. © 2010 Wiley Periodicals, Inc.
EphB3 Limits the Expansion of Neural Progenitor Cells in the Subventricular Zone by Regulating p53 During Homeostasis and Following Traumatic Brain Injury
Authors: Theus Michelle H. , Ricard Jerome , Bethea John R. , Liebl Daniel J. 
Published: May 2010

Abstract
Ephrins and Eph receptor(s) have recently been implicated in regulating neurogenesis in the adult subventricular zone (SVZ) and rostral migratory stream. Here, we examined the role of ephrinB3-EphB3 signaling in mediating the SVZ response to traumatic brain injury (TBI). Analysis of EphB3 expression showed colocalization with glial fibrillary acidic protein-positive neural stem progenitor cells (NSPCs) and doublecortin-positive neuroblasts, whereas ephrinB3 was expressed outside the neurogenic region. TBI resulted in a significant reduction in EphB3 expression, which coincided with enhanced NSPC survival and proliferation at 3 and 7 days postinjury. Analysis of mice lacking either ephrinB3 (ephrinB3−/−) or EphB3 (EphB3−/−) showed a significant increase in bromodeoxyuridine (BrdU) incorporation and Ki67 immunoreactivity in the SVZ. Interestingly, cell death was dissimilar between knockout mice, where cell death was reduced in EphB3−/− but increased in ephrinB3−/− mice. Lateral ventricle infusion of soluble preclustered ephrinB3-Fc reversed the proliferative and cell death defects in ephrinB3−/− but not EphB3−/− mice and prevented TBI-induced proliferation in wild-type NSPCs. Coincidently, tumor suppressor p53 expression was increased following EphB3 stimulation and is reduced in the absence of either EphB3 or ephrinB3. Furthermore, pharmacological inhibition and siRNA knockdown of p53-attenuated ephrinB3-Fc-mediated growth suppression while having no effect on cell death in cultured NSPCs. These data demonstrate that EphB3 signaling suppresses NSPC proliferation in a p53-dependent manner, induces cell death in the absence of ligand stimulation and is transiently reduced in the SVZ to initiate the expansion and survival of endogenous adult NSPCs following TBI.
Observed trends in Earth System behavior
Authors: Steffen Will 
Published: May 2010

AbstractThe behavior of the Earth System over the past two centuries has been dominated by the rapid rise of human activities as a significant geophysical force at the global scale. After the proximate and ultimate human drivers of change in the Earth System are described, the cumulative impact of these drivers on the structure and functioning of the Earth System are explored. Although the imprints of human activities are most profound on the land surface and in the atmosphere, significant effects are also discernible in the coastal seas, in the ocean, and—indirectly—in the cryosphere. The perturbations to the carbon cycle by human activities, most notably the burning of fossil fuels, is the most well‐known example of change in global biogeochemical cycling over the past two centuries. However, human modification of the nitrogen cycle is arguably even more pervasive, and other biogeochemical cycles, such as the phosphorus and sulfur cycles, have also been significantly altered by human activities. The changes to the planet's biodiversity over the past two centuries have been profound and continue to accelerate; the Earth is now in the midst of its sixth great extinction event. All of these human‐driven changes have implications for the climate system, and in turn are affected by changes in the physical climate. The concept of the Anthropocene—the proposal that the Earth has entered a new geological epoch—is a powerful way to understand the many interacting ways in which over six billion humans have collectively become a geophysical force that rivals the great forces of Nature and are now driving accelerating changes to the behavior of the Earth System Copyright © 2010 John Wiley & Sons, Ltd.This article is categorized under:

Paleoclimates and Current Trends > Earth System Behavior
Effect of Pancreaticoduodenectomy on the Course of Hepatic Steatosis
Authors: Yu Hsin‐Hsien , Shan Yan‐Shen , Lin Pin‐Wen 
Published: May 2010

AbstractBackgroundThe progression of hepatic steatosis after pancreaticoduodenectomy (PD) is controversial. This study was designed to determine whether PD would influence the course of hepatic steatosis.MethodsPatients admitted for PD and distal pancreatectomy (DP) from January 2004 to January 2008 were enrolled. Exclusion criteria included liver metastasis, severe obesity (body mass index >30), diabetic mellitus, excessive alcohol consumption, and unavailable preoperative and 6‐month postoperative unenhanced CT images. The pre‐PD and post‐PD liver attenuation, ratio, and difference of liver‐to‐spleen attenuation between liver and spleen attenuation were compared.ResultsFifty patients who underwent PD and 20 patients who underwent DP were eligible. The mean follow‐up period was 18.2 ± 1.6 months for the PD group and 19.7 ± 1.7 months for the DP group. Liver attenuation after PD was significantly decreased from 52.3 ± 1.1 H. to 47.6 ± 2 H. (p = 0.044), but no difference was observed in spleen attenuation. The liver‐to‐spleen attenuation ratio after PD also was significantly decreased: 1.12 ± 0.02 versus 1.01 ± 0.04 (p = 0.033). No difference in liver attenuation was found in the DP group. The female gender was a significant risk factor.ConclusionsThe liver attenuation of CT images decreases in patients who receive PD, which implicates that hepatic steatosis can develop after PD; however, the mechanism needs to be elucidated.
Long-Term Results of Modified Green Method in Sprengel's Deformity
Authors: Gonen Emel , Simsek Umit , Solak Sukru , Bektaser Bulent , Ates Yalim , Aydin Erbil 
Published: May 2010

Aim Congenital undescended scapula (Sprengel deformity) is a rare deformity that is reported in the literature mostly as small case series with short- or medium-term follow-up periods. Here, we aimed to present the long-term results of this deformity treated with modified Green procedure. Method The modified Green procedure was performed in 24 patients (28 shoulders) with Sprengel deformity. Clavicular osteotomy accompanied in all, and omovertebral bone excision in 13 shoulders. The mean age of the patients at the time of surgery was 4.5 years (range 1.5–17 years). Mean follow-up period was 11 years 4 months (4.3–17 years). Preoperative cosmetic appearance was noted as Cavendish III in 17 shoulders and as IV in 11 shoulders. In addition to the Cavendish scale, shoulder abduction, shoulder asymmetry, and scapular elevation and medialization were evaluated. Results The decrease in scapular elevation and Cavendish scale, and the improvement in shoulder abduction and scapular medialization postoperatively were statistically significant ( P < 0.001). Cosmetic improvement of at least one Cavendish grade were attained in 88.9% of shoulders. One patient (unilateral) who was Cavendish grade IV preoperatively died in the early postoperative period from unrelated causes. Of the remaining 10 preoperatively grade IV shoulders, 2 remained at the same grade, 1 improved to grade III, and 7 shoulders to grade I. Of the 17 preoperatively grade III shoulders, 1 shoulder stayed the at same grade, 7 shoulders improved to II, and 9 shoulders to grade I. Postoperative winging in 2 shoulders and hypertrophic scarring in 6 shoulders were noted. Conclusion The modified Green procedure is a relatively safe and reliable method in the treatment of severe Sprengel deformity cases and provides highly constructive and aesthetic results in the long term.
,,Die Tablette ist wie ein Freund‘‘- Die unterschätzte Medikamentenabhängigkeit!
Authors: Glaeske Gerd 
Published: May 2010

Einleitung
Schätzungen der Konsummuster bei Arzneimitteln mit Abhängigkeitspotenzial zeigen, dass 1,5 Millionen Menschen - viele Experten meinen sogar 1,9 Millionen - bei uns abhängig von Arzneimitteln sind: 2/3 von Schlaf- und Beruhigungsmitteln, die Übrigen von starken Schmerz- und Migränemitteln, von Hustenmitteln und Psychostimulanzien. Diese Zahlen sind seit vielen Jahren relativ konstant. Es sind vor allem die verschreibungspflichtigen Mittel, die zu einem Abhängigkeitsproblem führen können und dieses wird insbesondere von Experten begleitet. Daher ist vor allem auch die Verantwortung der Ärzte und Apotheker gefragt, wenn es um Präventionsmaßnahmen dieser „Sucht auf Rezept und aus der Apotheke“ geht.
Potential effects of pollen from stacked Bt maize on non-target Lepidoptera in agrarian systems
Authors: Schuppener Mechthild , Slusarenko Alan , Rauschen Stefan 
Published: May 2010

AbstractThe cultivation of genetically engineered (GE) maize expressing Lepidopteran specific Bt proteins poses potential risk for non-target butterflies. Pollen is dispersed by wind in the surroundings of maize fields, deposited on weeds and taken up by non-target butterfly lavae. While MON810 contains low concentrations of Bt protein in pollen, this is not necessarily true for new GE maize lines.Species appropriate for a post market environmental monitoring (PMEM) should (i) have a small host range to ensure a comprehensive inventory, (ii) be representative and (iii) be common in agrarian landscapes. Rare species seem to be inappropriate (Aviron et al. 2009). We selected the Small Tortoiseshell (Aglais urticae) and the Peacock (Inachis io) the larvae of which are monophage on the Stinging nettle (Urtica dioica). We analysed the suitability of these species for PMEM by mapping patches of U. dioica and populations of the butterflies in two different agrarian regions of Germany during maize anthesis.There was high temporal variability in the occurrence of butterflies and in the spatial distribution of U. dioica patches. In general, methods and species used seem to be appropriate for PMEM.