11 research outputs found

    Mitochondriotropic lanthanide nanorods : implications for multimodal imaging

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    Organelles such as mitochondria, lysosome, and nucleus, are essential for controlling basic cellular operations and metabolism. Because mitochondria play a critical role in energy production and programmed cell death, they act as prime therapeutic targets for various diseases and dysfunctional states. In this study, a multifunctional nanoplatform based on lanthanide upconverting nanorods is developed for concurrent mitochondria-targeted fluorescence imaging and preclinical MRI. This study provides critical insights into the spectral profiles of mitochondria and paves the way to developing novel, multimodal nanoprobes for mitochondria-targeted theranostics

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    Animal Functional Magnetic Resonance Imaging: Trends and Path Toward Standardization

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    Contains fulltext : 219658.pdf (publisher's version ) (Open Access)Animal whole-brain functional magnetic resonance imaging (fMRI) provides a non-invasive window into brain activity. A collection of associated methods aims to replicate observations made in humans and to identify the mechanisms underlying the distributed neuronal activity in the healthy and disordered brain. Animal fMRI studies have developed rapidly over the past years, fueled by the development of resting-state fMRI connectivity and genetically encoded neuromodulatory tools. Yet, comparisons between sites remain hampered by lack of standardization. Recently, we highlighted that mouse resting-state functional connectivity converges across centers, although large discrepancies in sensitivity and specificity remained. Here, we explore past and present trends within the animal fMRI community and highlight critical aspects in study design, data acquisition, and post-processing operations, that may affect the results and influence the comparability between studies. We also suggest practices aimed to promote the adoption of standards within the community and improve between-lab reproducibility. The implementation of standardized animal neuroimaging protocols will facilitate animal population imaging efforts as well as meta-analysis and replication studies, the gold standards in evidence-based science

    Transforming Growth Factor-β Receptors Interact with AP2 by Direct Binding to β2 Subunit

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    Transforming growth factor-β (TGF-β) superfamily members regulate a wide range of biological processes by binding to two transmembrane serine/threonine kinase receptors, type I and type II. We have previously shown that the internalization of these receptors is inhibited by K(+) depletion, cytosol acidification, or hypertonic medium, suggesting the involvement of clathrin-coated pits. However, the involvement of the clathrin-associated adaptor complex AP2 and the identity of the AP2 subunit that binds the receptors were not known. Herein, we have studied these issues by combining studies on intact cells with in vitro assays. Using fluorescence photobleaching recovery to measure the lateral mobility of the receptors on live cells (untreated or treated to alter their coated pit structure), we demonstrated that their mobility is restricted by interactions with coated pits. These interactions were transient and mediated through the receptors' cytoplasmic tails. To measure direct binding of the receptors to specific AP2 subunits, we used yeast two-hybrid screens and in vitro biochemical assays. In contrast to most other plasma membrane receptors that bind to AP2 via the μ2 subunit, AP2/TGF-β receptor binding was mediated by a direct interaction between the β2-adaptin N-terminal trunk domain and the cytoplasmic tails of the receptors; no binding was observed to the μ2, α, or ς2 subunits of AP2 or to μ1 of AP1. The data uniquely demonstrate both in vivo and in vitro the ability of β2-adaptin to directly couple TGF-β receptors to AP2 and to clathrin-coated pits, providing the first in vivo evidence for interactions of a transmembrane receptor with β2-adaptin

    Solar-t : Terahertz Photometers To Observe Solar Flare Emission On Stratospheric Balloon Flights

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    A new solar flare spectral component has been found with intensities increasing for larger sub-THz frequencies, spectrally separated from the well known microwaves component, bringing challenging constraints for interpretation. Higher THz frequencies observations are needed to understand the nature of the mechanisms occurring in flares. A twofrequency THz photometer system was developed to observe outside the terrestrial atmosphere on stratospheric balloons or satellites, or at exceptionally transparent ground stations. 76 mm diameter telescopes were designed to observe the whole solar disk detecting small relative changes in input temperature caused by flares at localized positions at 3 and 7 THz. Golay cell detectors are preceded by low-pass filters to suppress visible and near IR radiation, band-pass filters, and choppers. It can detect temperature variations smaller than 1 K with time resolution of a fraction of a second, corresponding to small burst intensities. The telescopes are being assembled in a thermal controlled box to which a data conditioning and acquisition unit is coupled. While all observations are stored on board, a telemetry system will forward solar activity compact data to the ground station. The experiment is planned to fly on board of long-duration stratospheric balloon flights some time in 2013-2015. One will be coupled to the GRIPS gamma-ray experiment in cooperation with University of California, Berkeley, USA. One engineering flight will be flown in the USA, and a 2 weeks flight is planned over Antarctica in southern hemisphere summer. Another long duration stratospheric balloon flight over Russia (one week) is planned in cooperation with the Lebedev Physics Institute, Moscow, in northern hemisphere summer. © 2012 SPIE.8442The Society of Photo-Optical Instrumentation Engineers (SPIE)Erickson, E.F., SOFIA: The next generation airborne observatory (1985) Space Sci. Rev., 84, pp. 91-100Poglitsch, A., The photodetector array camera and spectrometer (PACS) on the Herschel space observatory (2010) Astron. Astrophys., 518 (L2), pp. 1-12Degiacomi, C.G., Kneubühl, F.K., Huguenin, D., Far-infrared solar imaging from a balloon-borne platform (1985) Astrophys. J., 298, pp. 918-933Lawrence, J.S., Infrared and submillimeter atmospheric characteristics of high Antarctic plateau sites (2004) Publ. Astron Soc. Pacific, 116, pp. 482-492Marcon, R., Terahertz photometer to observe solar flares in continuum (2012) J. Infrared, Millimeter and Terahertz Waves, 33, pp. 192-205Marcon, R., Kaufmann, P., (2011) Método Para Maximizar Ganho Na Detecção Simultânea de Radiação de Fontes Pequenas em Campo Extenso de Visão, , Brazil Patent Application, Universidade Estadual de Campinas and Instituto Presbiteriano Mackenzie, March 30Phillips, T.G., (1988) Techniques of Submillimeter Astronomy, in Millimetre and Submillimetre Astronomy, pp. 1-25. , (Ed. by R.D. Wolstencroft and W.B. Burton), Lectures at Summer School, Stirling, Scotland, June 21-27, 1987 (Kluwer Academic Publishers, Dordrecht, NL)http://www.tydexoptics.com/pdf/Golay_cell.pdfShih, A.Y., The gamma-ray imager/polarimeter for solar flares (GRIPS) (2008) American Geophysical Union, , Fall Meeting, abstract SM11B-1602Texereau, J., (1984) How to Make A Telescope, pp. 139-175. , 2th English Edition (Wilmann-Bell Inc. Richmond, VA)Bortolucci, E.C., THz band-pass resonant metal mesh filters for a space solar photometry experiment (2012) VII SEMINATEC 2012 Workshop, , FEI, São Bernardo do Campo, SP, Brazil, 12-13 April(2012), http://www.tydexoptics.com/pdf/THz_Low_Pass_Filter.pdf(2012), http://www.eopc.com/choppers.html(2012), http://www.tydexoptics.com/new_products1/digital_golaycellhttp://www.satrunner.com/en/iridium-9602-sbd-modem.htmlhttp://www.wcclp.com/SBD.as
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