6,478 research outputs found

    COMPUTER-GENERATED HOLOGRAM ETCHED IN GAAS FOR OPTICAL INTERCONNECTION OF VLSI CIRCUITS

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    By integrating, on a wafer plane, GaAs semiconductor optoelectronic modulators and detectors with computer-generated holograms between then, the potential for in-plane interconnections is proposed. We report the fabrication and characterisation of a binary-phase relief hologram etched in a GaAs wafer using an averaged Fresnel zone plate design to focus light to 2 x 2 spots for array interconnection. Efficiencies of 28% for this design of binary CGH etched in GaAs have been achieved, close to the theoretical maximum

    Lokalisation und Gen - Expressionsregulation der neutralen Endopeptidase in der humanen Prostata

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    Die neutrale Endopeptidase (NEP, EC 3.4.24.11; weitere Synonyme: Neprilysin, CD 10, CALLA) ist ein Typ II - integrales Membranenzym in SĂ€ugerzellen, die als Zink enthaltende Endopeptidase die lokale Konzentrationen der Peptidsubstrate und der dazugehörigen Peptid-vermittelten SignalĂŒbertragungsprozesse steuern kann. Im Gegensatz zu den anregendaten, die von NEP-AktivitĂ€t und -Regulation in den Prostataepithelzellen handeln, nur einige Studien sind auf dem zellularen Expression und der Lokalisation der NEP in den Stromal- und Karzinom-zellen der Prostata vorhanden. Um zu prĂŒfen, ob Unterschiede in der NEP-Verteilung in der normalen und der pathologisch verĂ€nderten Prostata als auch in der Prostatazellen bestehen, wurde die NEP-Lokalisation mit Hilfe der indirekten Immunfluoreszenz - Methode an Prostatazellen und Paraffinschnitten der humanen Prostata untersucht. In der normalen adulten Prostata, wurde die NEP hauptsĂ€chlich an der apikalen Plasmamembran detektiert. Im Stroma wurden die Endothelzellen der Kapillaren und einige glatte Muskelzellen schwach gefĂ€rbt. In hyperplastischen DrĂŒsen war die ImmunreaktivitĂ€t der NEP in den adluminalen Zellen an der apikalen Plasmamembran nachzuweisen. Im Stroma wurden auch die Endothelzellen der Kapillaren und glatte Muskelzellen gefĂ€rbt. Im Prostatakarzinom war meist eine generalisierte ImmunreaktivitĂ€t der Zellen vorhanden und die NEP war nicht auf die apikale Plasmamembran beschrĂ€nkt. Sie verteilte sich vielmehr im gesamten Zytoplasma und ist damit offensichtlich ein Indikator fĂŒr den PolaritĂ€ts- bzw. Differenzierungsverlust in anaplastischen Prostata-karzinomzellen. Die LNCaP zeigten eine intensive FĂ€rbung der Plasmamembran, das gesamte Zytoplasma wurde schwĂ€cher gefĂ€rbt, wĂ€hrend die hPCPs nach Inkubation mit dem Antikörper nur eine schwache Reaktion in Zytoplasma aufwiesen. NEP-Genexpression wurde von RT-PCR ĂŒberwacht, und NEP mRNA im menschlichen Prostatagewebe und in Prostatazellen wurde mittels in-situ-RT-PCR ermittelt. Prostatagewebe zeigte starke Signale im glandulĂ€ren Epithel und schwache Signale im Stroma, kultivierte Zellen zeigten starke Signale in den Prostatakrebszellen (LNCaP) und schwache Signale in den stromal Zellen an (hPCPs). Die NEP-Protein wurde mit Hilfe der Westernblot-Analyse an Lysaten der epithelialen LNCaP und der stromalen hPCPs nachgewiesen. Die Experimente bestĂ€tigen den Expression von NEP nach beiden Zelle Arten, jedoch zeigte das Experiment mit hPCPs Zellen zwei BĂ€nder. Um zu untersuchen, ob Androgene und Neuropeptide in die Expression der NEP in LNCaP- bzw. hPCPs-Zellen involviert sind, wurde die Expression der NEP durch Northern-Blot-Analyse der Total-RNA untersucht. Ohne Stimulation ist eine grundlegende NEP-Expression in den LNCaP-Zellen detektierbar, Die Behandlung mit DHT bzw. Bombesin fĂŒhrt zu einer 4-Fach-Erhöhung der NEP-Expression. In den hPCPs-Zellen ist kaum eine NEP-Expression detektierbar und die Expression ist unabhĂ€ngig von DHT- oder Bombesin-Stimulation. Die basale NEP-Expression in den hPCPs-Zellen besitzt im Vergleich zu den LNCaP-Zellen nur eine um ca. 30% Menge. Die Sequenzanalyse des NEP-Promotors deckt zwei Androgenresponsionselemente einschließlich ein typisches ARE auf, welches Androgen-, Progesteron- und Glukocorticoid-Receptoren bindet und ein einzigartiges ARR, das nur Androgenreceptor bindet. Durch Deletionsanalyse und Transfektionsexperiment der Promotorkonstrukte wurden mehre cis-regulatorische Elemente am NEP-Typ II Promotor identifiziert. Mit Deletionsanalyse und Transfektionsexperiment der Promotorkonstrukte, DNase I Footprinting und Bandshift wurden zwei an die proximale Promotorregion bindene Faktoren identifiziert, ein Sp-Faktor an der GC-Box von -250 bis -262 bindet und ein NF-Y Faktor an der CCAAT-Box im Schutzbereich -142 / -110 des Promotors bindet. Transfektion des Reportergenkonstruktes mit durch Mutation standene Variation der Verbindungsstelle, die in EMSAs die DNA-Bindung blockieren kann, zeigte, daß NF-Y fĂŒr die basale AktivitĂ€t des Promotors wichtig ist und daß der Sp-Faktor wichtig fĂŒr die Androgen-Responsewirkung des Androgen-Responseelements ist

    CORRELATIONS OF POSTURAL CONTROL TO PROPRIOCEPTION, TACTILE SENSATION AND MUSCLE STRENGTH AMONG OLDER ADULTS

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    Background: Falls are one of the most important causes of physical injury and death in older adults. Postural control is associated with an elevated risk of falls in older adults. the purpose of this study was to assess the correlation between static/dynamic postural control ability and proprioception, plantar skin touch, and muscle strength in older adults. Method: Partial correlation analysis was used to quantitatively analyze the correlation between plantar tactile sensitivity, proprioception, lower limb muscle strength and postural control, and regression analysis was used to build an effective model of human postural control. Result: The postural control of the older adults is related to the plantar tactile sensitivity, proprioception, and lower limb muscle strength. Conclusion: dynamic postural control mainly affected by lower limb muscle strength and proprioception, suggesting that trainings to improve the ankle plantarflexion, hip abduction muscle strength and knee and ankle proprioception should be recommended to older adults to improve dynamic postural control. Static postural control mainly affected by planter tactile sensitivity and proprioception suggesting that trainings to improve the proprioception and planter tactile sensitivity should be recommended to older adults to improve static postural control

    THE IMPACT OF NATIONAL CULTURE ON BILATERAL TRADE IN VIETNAM

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    The purpose of this paper is to examine whether or to what extent national culture influences bilateral trade flows between Vietnam and its trading partners. Using a panel dataset of 52 countries from 2001 till 2011 and six cultural dimensions of Hofstede, the regression analysis performed by gravity model shows that national culture and bilateral trade flows between Vietnam and trading partners are significantly correlated. This study's implications may help macro-policy makers devise better export promotion policies and boost the volume of bilateral trade between Vietnam and other countries around the world

    Efficacy of Monetary Transmission Mechanism: Experiences in the SEACEN Countries

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    The main objective of the project is to analyse and assess the efficacy of the monetary transmission mechanism (MTM) in the SEACEN countries, in the light of financial liberalisation, globalisation and changing monetary and exchange rate regime in some SEACEN countries. It covers MTM and related issues such as recent changes in the objectives and targeting regime of monetary policy, empirical evidence of impact of monetary policy on prices and economic activities, recent changes in the exchange rate regime and capital mobility, and effectiveness of the various MTM based on the latest empirical findings of the respective countries.

    Impact of IT Revolution on The Financial Structure of The SEACEN Countries: Challenges Facing Central Banks

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    This project aims to analyse the impact of IT revolution on the financial structure and the policy responses of central banks in the SEACEN countries. Since IT revolution in the SEACEN countries is still under way, it is not easy to predict the outcome of its impact at the present time, but IT is expected to substantially influence the financial markets and economy. There are several issues that the central banks in the SEACEN region needs to tackle with.

    3D reconstruction of multiple stained histology images.

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    Three dimensional (3D) tissue reconstructions from the histology images with different stains allows the spatial alignment of structural and functional elements highlighted by different stains for quantitative study of many physiological and pathological phenomena. This has significant potential to improve the understanding of the growth patterns and the spatial arrangement of diseased cells, and enhance the study of biomechanical behavior of the tissue structures towards better treatments (e.g. tissue-engineering applications)

    Microstructural damage of the posterior corpus callosum contributes to the clinical severity of neglect

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    One theory to account for neglect symptoms in patients with right focal damage invokes a release of inhibition of the right parietal cortex over the left parieto-frontal circuits, by disconnection mechanism. This theory is supported by transcranial magnetic stimulation studies showing the existence of asymmetric inhibitory interactions between the left and right posterior parietal cortex, with a right hemispheric advantage. These inhibitory mechanisms are mediated by direct transcallosal projections located in the posterior portions of the corpus callosum. The current study, using diffusion imaging and tract-based spatial statistics (TBSS), aims at assessing, in a data-driven fashion, the contribution of structural disconnection between hemispheres in determining the presence and severity of neglect. Eleven patients with right acute stroke and 11 healthy matched controls underwent MRI at 3T, including diffusion imaging, and T1-weighted volumes. TBSS was modified to account for the presence of the lesion and used to assess the presence and extension of changes in diffusion indices of microscopic white matter integrity in the left hemisphere of patients compared to controls, and to investigate, by correlation analysis, whether this damage might account for the presence and severity of patients' neglect, as assessed by the Behavioural Inattention Test (BIT). None of the patients had any macroscopic abnormality in the left hemisphere; however, 3 cases were discarded due to image artefacts in the MRI data. Conversely, TBSS analysis revealed widespread changes in diffusion indices in most of their left hemisphere tracts, with a predominant involvement of the corpus callosum and its projections on the parietal white matter. A region of association between patients' scores at BIT and brain FA values was found in the posterior part of the corpus callosum. This study strongly supports the hypothesis of a major role of structural disconnection between the right and left parietal cortex in determining 'neglect'
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