298 research outputs found

    Shaped Pupil Lyot Coronagraphs: High-Contrast Solutions for Restricted Focal Planes

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    Coronagraphs of the apodized pupil and shaped pupil varieties use the Fraunhofer diffraction properties of amplitude masks to create regions of high contrast in the vicinity of a target star. Here we present a hybrid coronagraph architecture in which a binary, hard-edged shaped pupil mask replaces the gray, smooth apodizer of the apodized pupil Lyot coronagraph (APLC). For any contrast and bandwidth goal in this configuration, as long as the prescribed region of contrast is restricted to a finite area in the image, a shaped pupil is the apodizer with the highest transmission. We relate the starlight cancellation mechanism to that of the conventional APLC. We introduce a new class of solutions in which the amplitude profile of the Lyot stop, instead of being fixed as a padded replica of the telescope aperture, is jointly optimized with the apodizer. Finally, we describe shaped pupil Lyot coronagraph (SPLC) designs for the baseline architecture of the Wide-Field Infrared Survey Telescope-Astrophysics Focused Telescope Assets (WFIRST-AFTA) coronagraph. These SPLCs help to enable two scientific objectives of the WFIRST-AFTA mission: (1) broadband spectroscopy to characterize exoplanet atmospheres in reflected starlight and (2) debris disk imaging.Comment: 41 pages, 15 figures; published in the JATIS special section on WFIRST-AFTA coronagraph

    Permeable, Non-irritating Prodrugs of Nonsteroidal and Steroidal Agents

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    Prodrugs containing an active drug molecule linked to a polyethylene glycol group, and a method of use thereof are described. Exemplary soluble ester prodrugs contain naproxen, triamcinolone acetonide, gancyclovir, taxol, cyclosporin, dideoxyinosine, trihydroxy steroids, and flurbiprofen molecules linked to polyethylene glycol (PEG) groups. Pharmaceutical compositions containing these prodrugs, and a method of using these esters for treating disease states or symptoms are also described

    Multihospital Outbreak of Clostridium difficile Infection, Cleveland, Ohio, USA

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    To determine whether a multihospital Clostridium difficile outbreak was associated with epidemic strains and whether use of particular fluoroquinolones was associated with increased infection rates, we cultured feces from C. difficileā€“infected patients. Use of fluoroquionolones with enhanced antianaerobic activity was not associated with increased infection rates

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    The following publications have been reviewed by the mentioned authors;Ideas Bank Design Technology: Designing & Making Book 1 - reviewed by Robert BowenAztecs - Your Move - reviewed by Bridget A. EganChanging Technology - reviewed by John Hill & Elizabeth WrightElectronic Circuits and Components/ The Parts Gallery - reviewed by Mark HudsonGCSE Design and Technology: Resistant Materials - reviewed by John DurrellGlobal contexts: an introduction for design and technology teachers - reviewed by Anne RiggsScience Resources for Key Stage 2: SATIS 8-14 Technology - reviewed by Richard AgerScience Resources for Key Stage 2: SATIS 8-14 Health - reviewed by Richard AgerScience Resources for Key Stage 2: SATIS 8-14 Materials/Transport/Environment - reviewed by Robert BowenTechnology an Enterprising Approach - reviewed by Dr Ron RichieUnderstanding Electronic Circuits CD-ROM - reviewed by Dr Rowland Dye and Phil NormanTextiles and Technology - reviewed by Jillian MellorArt and Design 97 - reviewed by Andy Brecko

    The Influence of HLA on HIV-Associated Neurocognitive Impairment in Anhui, China

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    HLA-DR*04 was identified as a predictor of HIV-Associated neurocognitive disorder (HAND), low CD4 T-cell responses to HIV, and low plasma HIV RNA levels in a U.S. cohort. We hypothesized that low CD4 T-cell activation leads to poor immune control of HIV in the CNS, predisposing to HAND, but also provided fewer target (activated CD4 T-cells) for HIV replication. To assess the consistency of these HLA Class II associations in a new cohort and extend analysis to HLA Class I, HLA types, neurocognitive, and virologic status were examined in a cohort of former plasma donors in China.178 HIV infected individuals in Anhui China, were HLA typed and underwent neurocognitive evaluations (using locally standardized norms), neuromedical, treatment and virologic assessments at baseline and at 12 months.HLA DR*04 was associated with a higher rate of baseline neurocognitive impairment (pā€Š=ā€Š0.04), neurocognitive decline (pā€Š=ā€Š0.04), and lower levels of HIV RNA in plasma (pā€Š=ā€Š0.05). HLA Class I alleles (B*27,57,58,A*03,33) that specify a CD8 T-cell response to conserved HIV sequences were neuroprotective, associated with less impairment at baseline (pā€Š=ā€Š0.037), at month 012 (pā€Š=ā€Š0.013) and less neurocognitive decline (pā€Š=ā€Š0.023) in the interval. Consistent with the theory that effective CD8 T-cell responses require CD4 T-cell support, the HLA DR*04 allele reduced the neuroprotective effect of the Class I alleles. The presence of HLA-DR*04 and the Alzheimer associated allele ApoE4 in the same individual had a synergistic negative effect on cognition (pā€Š=ā€Š0.003).Despite major background differences between U.S. and Anhui China cohorts, HLA DR*04 predicted neurocognitive impairment and lower plasma HIV RNA levels in both populations. HLA Class I alleles associated with CD8 T-cell control of HIV were associated with protection from HAND, but protection was reduced in the presence of HLA-DR*04
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