1,269 research outputs found

    Synthesis and Characterization of ÎČ-Cyclodextrin/alginate Nanoparticle as a Novel Drug Delivery System

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    The aim of this work was to study a novel nanoparticle system formed from alginate and ÎČ-cyclodextrin by ionotropic gelation method and to evaluate their potential for the association and delivery of drugs. The nanoparticles were prepared by electrostatic interactions between Ca2+/alginate gel and ÎČ-cyclodextrin. Morphology and structure characterization of nanoparticles was investigated by scanning electron micrographs (SEM), transmission electron microscope (TEM), Fourier transform infrared spectra (FTIR). The nanoparticle size was about 50 – 80 nm and their structure quite regular and consistent. Ketoprofen, chosen as a model drug, was incorporated into the nanocarriers with association efficiency of 50.7 % and loading efficiency of 5.7 %. Ketoprofen released from the nanoparticles was 57 % at pH 7.4 and 69 % at pH 5.0 for 4 h

    Sersiclets - A Matched Filter Extension of Shapelets for Weak Lensing Studies

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    The precision study of dark matter using weak lensing by large scale structure is strongly constrained by the accuracy with which one can measure galaxy shapes. Several methods have been devised but none have demonstrated the ability to reach the level of precision required by future weak lensing surveys. In this Letter we explore new avenues to the existing Shapelets approach, combining a priori knowledge of the galaxy profile with the power of orthogonal basis function decomposition. This Letter discusses the new issues raised by this matched filter approach and proposes promising alternatives to shape measurement techniques. In particular it appears that the use of a matched filter (e.g. Sersic profile) restricted to elliptical radial fitting functions resolves several well known Shapelet issues.Comment: 6 pages, 6 figures. MNRAS Accepte

    Measurement of Cosmic-ray Muons and Muon-induced Neutrons in the Aberdeen Tunnel Underground Laboratory

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    We have measured the muon flux and production rate of muon-induced neutrons at a depth of 611 m water equivalent. Our apparatus comprises three layers of crossed plastic scintillator hodoscopes for tracking the incident cosmic-ray muons and 760 L of gadolinium-doped liquid scintillator for producing and detecting neutrons. The vertical muon intensity was measured to be IÎŒ=(5.7±0.6)×10−6I_{\mu} = (5.7 \pm 0.6) \times 10^{-6} cm−2^{-2}s−1^{-1}sr−1^{-1}. The yield of muon-induced neutrons in the liquid scintillator was determined to be Yn=(1.19±0.08(stat)±0.21(syst))×10−4Y_{n} = (1.19 \pm 0.08 (stat) \pm 0.21 (syst)) \times 10^{-4} neutrons/(Ό⋅\mu\cdotg⋅\cdotcm−2^{-2}). A fit to the recently measured neutron yields at different depths gave a mean muon energy dependence of ⟹EΌ⟩0.76±0.03\left\langle E_{\mu} \right\rangle^{0.76 \pm 0.03} for liquid-scintillator targets.Comment: 14 pages, 17 figures, 3 table
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