38 research outputs found

    Dual Laser Beam Processing of Semiconducting Thin Films by Excited State Absorption

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    We present a unique dual laser beam processing approach based on excited state absorption by structuring 200 nm thin zinc oxide films sputtered on fused silica substrates. The combination of two pulsed nanosecond-laser beams with different photon energies—one below and one above the zinc oxide band gap energy—allows for a precise, efficient, and homogeneous ablation of the films without substrate damage. Based on structuring experiments in dependence on laser wavelength, pulse fluence, and pulse delay of both laser beams, a detailed concept of energy transfer and excitation processes during irradiation was developed. It provides a comprehensive understanding of the thermal and electronic processes during ablation. To quantify the efficiency improvements of the dual-beam process compared to single-beam ablation, a simple efficiency model was developed

    Cat or Dog Ownership and Seroprevalence of Ehrlichiosis, Q Fever, and Cat-Scratch Disease

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    Concerns have been raised about the role of domestic cats or dogs in the acquisition of zoonoses, in particular in pregnant women or immune-suppressed persons. We report that cat or dog ownership is not associated with an increased seroprevalence of antibodies to Anaplasma phagozytophilum, Coxiella burnetii, and Bartonella henselae in symptom-free persons in Styria, Austria

    A Rapid, Highly Sensitive and Open-Access SARS-CoV-2 Detection Assay for Laboratory and Home Testing

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    RT-qPCR-based diagnostic tests play important roles in combating virus-caused pandemics such as Covid-19. However, their dependence on sophisticated equipment and the associated costs often limits their widespread use. Loop-mediated isothermal amplification after reverse transcription (RT-LAMP) is an alternative nucleic acid detection method that overcomes these limitations. Here, we present a rapid, robust, and sensitive RT-LAMP-based SARS-CoV-2 detection assay. Our 40-min procedure bypasses the RNA isolation step, is insensitive to carryover contamination, and uses a colorimetric readout that enables robust SARS-CoV-2 detection from various sample types. Based on this assay, we have increased sensitivity and scalability by adding a nucleic acid enrichment step (Bead-LAMP), developed a version for home testing (HomeDip-LAMP), and identified open-source RT-LAMP enzymes that can be produced in any molecular biology laboratory. On a dedicated website, rtlamp.org (DOI: 10.5281/zenodo.6033689), we provide detailed protocols and videos. Our optimized, general-purpose RT-LAMP assay is an important step toward population-scale SARS-CoV-2 testing.MK was supported by the Vienna Science and Technology Fund (WWTF) through project COV20-031 (to JZ) and a Cambridge Trust LMB Cambridge Scholarship. Research in the AP lab is supported by the Austrian Science Fund (START Projekt Y 1031-B28, SFB “RNA-Deco” F 80) and EMBO-YIP; research in the JB lab is supported by the European Research Council (ERC- 2015-CoG - 682181). The IMP receives generous institutional funding from Boehringer Ingelheim and the Austrian Research Promotion Agency (Headquarter grant FFG-852936); IMBA is generously supported by the Austrian Academy of Sciences. Work in the LM-A laboratory is supported by grant PID2019- 104176RB-I00/AEI/10.13039/501100011033 of the Spanish Ministry of Science and Innovation, and an institutional grant of the Fundación Ramón Areces.Peer reviewe

    Immunological fingerprint in coronavirus disease-19 convalescents with and without post-COVID syndrome

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    BackgroundSymptoms lasting longer than 12  weeks after severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) infection are called post-coronavirus disease (COVID) syndrome (PCS). The identification of new biomarkers that predict the occurrence or course of PCS in terms of a post-viral syndrome is vital. T-cell dysfunction, cytokine imbalance, and impaired autoimmunity have been reported in PCS. Nevertheless, there is still a lack of conclusive information on the underlying mechanisms due to, among other things, a lack of controlled study designs.MethodsHere, we conducted a prospective, controlled study to characterize the humoral and cellular immune response in unvaccinated patients with and without PCS following SARS-CoV-2 infection over 7 months and unexposed donors.ResultsPatients with PCS showed as early as 6 weeks and 7 months after symptom onset significantly increased frequencies of SARS-CoV-2-specific CD4+ and CD8+ T-cells secreting IFNγ, TNF, and expressing CD40L, as well as plasmacytoid dendritic cells (pDC) with an activated phenotype. Remarkably, the immunosuppressive counterparts type 1 regulatory T-cells (TR1: CD49b/LAG-3+) and IL-4 were more abundant in PCS+.ConclusionThis work describes immunological alterations between inflammation and immunosuppression in COVID-19 convalescents with and without PCS, which may provide potential directions for future epidemiological investigations and targeted treatments

    Strukturierung von Zinkoxid-DĂŒnnschichten mittels Zweistrahlanordnung unter Ausnutzung einer Excited-State-Absorption

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    The present work demonstrates the ns-laser pulse assisted excited state absoption (ESA)-based processing of Zinc(II)-oxide thin films with a layer thickness of 50 300 nm on crystallographically differently oriented quartz-, as well as crystalline sapphire-, and amophous fused silica substrates using a dual laser beam setup. The goal was to achieve an ablation efficiency improvement compared to single-beam ablation by decreasing the required pulse fluences. For the ESA-based ablation, the optical excitation with radiation of a laser with photon energies Ep above the optical band gap energy EBL was used to excite electrons into the conduction band (LB), which then partially relax into defect-levels. This allows the transient single-photon absorption of radiation of a second spatially and temporally aligned laser pulse with Ep < EBL, exciting electrons to the LB from these defect-levels. By utilizing different ESA-wavelengths in the visible spectrum with ESA = 410 600 nm, ESA = 450 nm was determined as the most effective wavelength for the ESA-based ablation due to the increased Ep, allowing the absorption from an increased number of suitable defect-levels. To quantify the efficiency improvements, a model was developed to allow for a comparison with single-beam ablation by determining the pulse fluence dependent size of the ablated structures. For a more detailed analysis of the ESA-based dual-beam process and to determine optimal processing parameters, a second model was developed to describe the temporal process and the impact of the temperature increase by the pump-pulse. In addition to ablation of variable ablation depths, the ablation quality was improved by decreasing resolidified molten structures and an ablation was achieved even with a temporal pulse delay in the s-range

    Dual Laser Beam Processing of Semiconducting Thin Films by Excited State Absorption

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    We present a unique dual laser beam processing approach based on excited state absorption by structuring 200 nm thin zinc oxide films sputtered on fused silica substrates. The combination of two pulsed nanosecond-laser beams with different photon energies—one below and one above the zinc oxide band gap energy—allows for a precise, efficient, and homogeneous ablation of the films without substrate damage. Based on structuring experiments in dependence on laser wavelength, pulse fluence, and pulse delay of both laser beams, a detailed concept of energy transfer and excitation processes during irradiation was developed. It provides a comprehensive understanding of the thermal and electronic processes during ablation. To quantify the efficiency improvements of the dual-beam process compared to single-beam ablation, a simple efficiency model was developed

    Elevated Fecal Candida Counts in Patients with Antibiotic-Associated Diarrhea: Role of Soluble Fecal Substances

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    To assess the role of soluble fecal substances in the elevation of fecal Candida counts in patients with antibiotic-associated diarrhea (AAD), we investigated the growth of Candida albicans in vitro in serially diluted stool fluids from patients with AAD and healthy subjects. There were significantly higher Candida albicans counts in stool fluids diluted 1:10 from AAD patients than in healthy subjects and the phosphate-buffered saline growth control, which may be due to reduced soluble Candida inhibitors and increased availability of growth factors and nutrients
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