496 research outputs found

    Antimicrobial and anti-inflammatory activity of chitosan-alginate nanoparticles: a targeted therapy for cutaneous pathogens.

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    Advances in nanotechnology have demonstrated potential application of nanoparticles (NPs) for effective and targeted drug delivery. Here we investigated the antimicrobial and immunological properties and the feasibility of using NPs to deliver antimicrobial agents to treat a cutaneous pathogen. NPs synthesized with chitosan and alginate demonstrated a direct antimicrobial activity in vitro against Propionibacterium acnes, the bacterium linked to the pathogenesis of acne. By electron microscopy (EM) imaging, chitosan-alginate NPs were found to induce the disruption of the P. acnes cell membrane, providing a mechanism for the bactericidal effect. The chitosan-alginate NPs also exhibited anti-inflammatory properties as they inhibited P. acnes-induced inflammatory cytokine production in human monocytes and keratinocytes. Furthermore, benzoyl peroxide (BP), a commonly used antiacne drug, was effectively encapsulated in the chitosan-alginate NPs and demonstrated superior antimicrobial activity against P. acnes compared with BP alone while demonstrating less toxicity to eukaryotic cells. Together, these data suggest the potential utility of topical delivery of chitosan-alginate NP-encapsulated drug therapy for the treatment of dermatologic conditions with infectious and inflammatory components

    Study of a Large NaI(Tl) Crystal

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    Using a narrow band positron beam, the response of a large high-resolution NaI(Tl) crystal to an incident positron beam was measured. It was found that nuclear interactions cause the appearance of additional peaks in the low energy tail of the deposited energy spectrum

    Status of the TRIUMF PIENU Experiment

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    The PIENU experiment at TRIUMF aims to measure the pion decay branching ratio R=Γ(π+e+νe(γ))/Γ(π+μ+νμ(γ))R={\Gamma}({\pi}^+{\rightarrow}e^+{\nu}_e({\gamma}))/{\Gamma}({\pi}^+{\rightarrow}{\mu}^+{\nu}_{\mu}({\gamma})) with precision <0.1<0.1% to provide a sensitive test of electron-muon universality in weak interactions. The current status of the PIENU experiment is presented.Comment: Talk presented CIPANP2015. 8 pages, LaTeX, 4 eps figure

    Improved Search for Heavy Neutrinos in the Decay πeν\pi\rightarrow e\nu

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    A search for massive neutrinos has been made in the decay πe+ν\pi\rightarrow e^+ \nu. No evidence was found for extra peaks in the positron energy spectrum indicative of pion decays involving massive neutrinos (πe+νh\pi\rightarrow e^+ \nu_h). Upper limits (90 \% C.L.) on the neutrino mixing matrix element Uei2|U_{ei}|^2 in the neutrino mass region 60--135 MeV/c2c^2 were set, which are %representing an order of magnitude improvement over previous results

    Precision Measurement of the π+→e+νe Branching Ratio in the PIENU Experiment

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    The PIENU experiment at TRIUMF aims to measure the branching ratio of the pion decay modes Rπ=[π+→e+νe(γ)]/[π+→μ+νμ(γ)] with precision of &lt;0.1%. Precise measurement of Rπ provides a stringent test of electron-muon universality in weak interactions. The current status of the PIENU experiment and future prospects are presented

    High Purity Pion Beam at TRIUMF

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    An extension of the TRIUMF M13 low-energy pion channel designed to suppress positrons based on an energy-loss technique is described. A source of beam channel momentum calibration from the decay pi+ --> e+ nu is also described.Comment: 5 page
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