729 research outputs found

    Techniques for Consecutive TEM and Atom Probe Tomography Analysis of Nanowires

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    Nanowires show great promise for development in many technological applications including electronics, photonics, and displays . Due to the fine scale of nanowires, transmission electron microscopy (TEM) and atom probe tomography (APT) are among a limited number of techniques that can measure the crystallographic and chemical nature of these structures which ultimately define their performance

    Techniques for Consecutive TEM and Atom Probe Tomography Analysis of Nanowires

    Get PDF
    Nanowires show great promise for development in many technological applications including electronics, photonics, and displays . Due to the fine scale of nanowires, transmission electron microscopy (TEM) and atom probe tomography (APT) are among a limited number of techniques that can measure the crystallographic and chemical nature of these structures which ultimately define their performance

    Autoantibody detection for diagnosis in direct immunofluorescence negative mucous membrane pemphigoid: ocular and other sites compared

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    Objective: To assess whether a panel of serum pemphigoid autoantibody tests could be used to confirm an immunopathological diagnosis of mucous membrane pemphigoid (MMP) in direct immunofluorescent negative (DIF-) MMP patients. / Design: Prospective cross-sectional study. / Subjects and controls: 76 patients with MMP involving ocular and non-ocular sites with 45 matched controls. / Tests: Enzyme linked immunosorbent assays (ELISA) for BP180 and BP230 (MBL International®), IgA and IgG indirect immunofluorescence on human salt-split skin (IIF SSS) and the keratinocyte footprint assay for anti-laminin 332 antibodies. / Main outcome measures: Sensitivity and specificity of autoantibody detection; significant differences for individual tests and test combinations for MMP involving different sites. / Results: All DIF- Cases (24/76, 31.8%) had either ocular only disease or ocular involvement in multi-site disease. Serum pemphigoid autoantibodies were detected in 29/76 (38.2%) of all MMP patients compared to 3/45 (6.7%) of controls. Autoantibody reactivity detected by any one or more of the tests was present in 6/24 (25%) DIF- cases compared to 22/49 (44.9%) in DIF positive (DIF+). Compared to controls ocular only MMP serum reactivity was not significantly different for any test or test combination whereas DIF- multisite ocular MMP differed for one ELISA and 3/7 test combinations. By contrast, for DIF+ non ocular MMP all the individual tests, apart from IgA IIF, and all test combinations were significantly different compared to controls. For the whole MMP cohort the sensitivity of all tests was low having a maximum of 21.05% for BP180 reactivity, increasing to 38.16% for an optimal test combination. Disease activity was strongly associated with positive serology findings. / Conclusions: Pemphigoid serum autoantibody tests did not provide alternative immunopathological evidence of MMP in ocular only MMP patients but had limited value in DIF- multisite ocular MMP. The requirement for immunopathological confirmation of MMP by autoantibody detection is inappropriate for DIF- ocular only MMP resulting in missed diagnoses, delayed therapy and poor outcomes. Alternative diagnostic criteria for MMP with ocular involvement are required, to exclude the other causes of scarring conjunctivitis, until more sensitive and specific immunopathology tests become available

    Hidradenitis suppurativa:The third cause of vulva carcinoma

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    The development of squamous cell carcinoma (SCC) is a severe complication of chronic HS (HS). HS associated SCC can present as a painful, persistent tumour or ulcer without typical HS characteristics such as sinus formation and inflammation. Especially male patients with prolonged HS in extra-axillary areas are at risk for this complication. This case of HS associated vulvar SCC emphasizes that also women can develop this complication. In addition to lichen sclerosus vulvae (via dVIN) and high risk HPV (via uVIN) there is a third disease that can lead to vulvar cancer; chronic HS. The clinician should be vigilant for the development of malignant transformation in cases of severe, chronic HS, and should have a low threshold for biopsy. Staging, therapy and follow-up should be performed by gynecologic oncologists in an academic center.</p

    The afterglows of gamma-ray bursts

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    Gamma-ray burst astronomy has undergone a revolution in the last three years, spurred by the discovery of fading long-wavelength counterparts. We now know that at least the long-duration GRBs lie at cosmological distances with estimated electromagnetic energy release of 10^51–10^53 erg, making these the brightest explosions in the Universe. In this article we review the current observational state, beginning with the statistics of X-ray, optical, and radio afterglow detections. We then discuss the insights these observations have given to the progenitor population, the energetics of the GRB events, and the physics of the afterglow emission. We focus particular attention on the evidence linking GRBs to the explosion of massive stars. Throughout, we identify remaining puzzles and uncertainties, and emphasize promising observational tools for addressing them. The imminent launch of HETE-2 and the increasingly sophisticated and coordinated ground-based and space-based observations have primed this field for fantastic growth

    The afterglows of gamma-ray bursts

    Get PDF
    Gamma-ray burst astronomy has undergone a revolution in the last three years, spurred by the discovery of fading long-wavelength counterparts. We now know that at least the long duration GRBs lie at cosmological distances with estimated electromagnetic energy release of 10^51–10^53 erg, making these the brightest explosions in the Universe. In this article we review the current observational state, beginning with the statistics of X-ray, optical, and radio afterglow detections. We then discuss the insights these observations have given to the progenitor population, the energetics of the GRB events, and the physics of the afterglow emission. We focus particular attention on the evidence linking GRBs to the explosion of massive stars. Throughout, we identify remaining puzzles and uncertainties, and emphasize promising observational tools for addressing them. The imminent launch of HETE-2 and the increasingly sophisticated and coordinated ground-based and space-based observations have primed this field for fantastic growth. This overview is a combined write-up of talks given at this conference and in NASA's Goddard Space Flight Center

    The afterglows of gamma-ray bursts

    Get PDF
    Gamma-ray burst astronomy has undergone a revolution in the last three years, spurred by the discovery of fading long-wavelength counterparts. We now know that at least the long duration GRBs lie at cosmological distances with estimated electromagnetic energy release of 10^51–10^53 erg, making these the brightest explosions in the Universe. In this article we review the current observational state, beginning with the statistics of X-ray, optical, and radio afterglow detections. We then discuss the insights these observations have given to the progenitor population, the energetics of the GRB events, and the physics of the afterglow emission. We focus particular attention on the evidence linking GRBs to the explosion of massive stars. Throughout, we identify remaining puzzles and uncertainties, and emphasize promising observational tools for addressing them. The imminent launch of HETE-2 and the increasingly sophisticated and coordinated ground-based and space-based observations have primed this field for fantastic growth

    Keratinocyte footprint assay discriminates antilaminin-332 pemphigoid from all other forms of pemphigoid diseases

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    Background Antilaminin-332 mucous membrane pemphigoid is a chronic severe pemphigoid disease characterized by autoantibodies to laminin-332. At present no commercial assay is available to demonstrate antilaminin-332 antibodies, and diagnosis relies on in-house techniques with limited sensitivities. Objectives In order to move, keratinocytes cultured in vitro secrete laminin-332 to attach to the culture dish. In that way, they leave behind a unique footprint trail of laminin-332. We aimed to develop a sensitive and specific laboratory assay to determine antilaminin-332 autoantibodies in patient serum based on binding of patient IgG to these unique footprints. Methods Normal human keratinocytes were grown on glass coverslips and incubated with patient or control serum for 1 h. The binding of IgG was then investigated by immunofluorescence. After validating the test for its ability to identify antilaminin-332 autoantibodies it was converted into a daily available test based on binding of IgG to dried coverslips that can be stored frozen. The staining patterns of sera from patients with antilaminin-332 pemphigoid were then compared with those of sera from patients with other autoimmune bullous diseases and normal human sera. Results IgG of all antilaminin-332 pemphigoid sera (n = 16) bound to laminin-332 footprints, while all normal human controls (n = 55) were negative. From the sera of patients with other diseases (n = 72) four sera tested positive. The footprint assay was also positive for sera that were negative by salt-split skin analysis, demonstrating that it is a very sensitive technique. Conclusions The keratinocyte footprint assay is a fast and specific assay to confirm or rule out the presence of antilaminin-332 autoantibodies. What's already known about this topic? Antilaminin-332 mucous membrane pemphigoid is a severe form of pemphigoid, and patients may have an increased risk of malignancies. The diagnosis of antilaminin-332 mucous membrane pemphigoid is complicated by the lack of specific commercial tests for antilaminin-332 antibodies and can be confirmed only in specialized laboratories. Keratinocytes in culture need laminin-332 for adhesion and migration and therefore deposit it on the bottom of the culture dish. What does this study add? The keratinocyte footprint assay detects antilaminin-332 autoantibodies in patient serum using the native laminin-332 produced by cultured keratinocytes. What is the translational message? The keratinocyte footprint assay is a fast and specific assay to confirm or rule out the presence of antilaminin-332 autoantibodies
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