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search.filters.applied.f.access: openAccess × DDC: 500 × Type: Text × Publisher: [London] : Macmillan Publishers Limited, part of Springer Nature × WGL Institute: TROPOS ×

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    Enhanced tenacity of mycobacterial aerosols from necrotic neutrophils
    ([London] : Macmillan Publishers Limited, part of Springer Nature, 2020) Pfrommer, E.; Dreier, C.; Gabriel, G.; Dallenga, T.; Reimer, R.; Schepanski, K.; Scherließ, R.; Schaible, U.E.; Gutsmann, T.
    The tuberculosis agent Mycobacterium tuberculosis is primarily transmitted through air, but little is known about the tenacity of mycobacterium-containing aerosols derived from either suspensions or infected neutrophils. Analysis of mycobacterial aerosol particles generated from bacterial suspensions revealed an average aerodynamic diameter and mass density that may allow distant airborne transmission. The volume and mass of mycobacterial aerosol particles increased with elevated relative humidity. To more closely mimic aerosol formation that occurs in active TB patients, aerosols from mycobacterium-infected neutrophils were analysed. Mycobacterium-infected intact neutrophils showed a smaller particle size distribution and lower viability than free mycobacteria. In contrast, mycobacterium-infected necrotic neutrophils, predominant in M. tuberculosis infection, revealed particle sizes and viability rates similar to those found for free mycobacteria, but in addition, larger aggregates of viable mycobacteria were observed. Therefore, mycobacteria are shielded from environmental stresses in multibacillary aggregates generated from necrotic neutrophils, which allows improved tenacity but emphasizes short distance transmission between close contacts.
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    Intercomparison of in-situ aircraft and satellite aerosol measurements in the stratosphere
    ([London] : Macmillan Publishers Limited, part of Springer Nature, 2019) Sandvik, Oscar S.; Friberg, Johan; Martinsson, Bengt G.; van Velthoven, Peter F. J.; Hermann, Markus; Zahn, Andreas
    Aerosol composition and optical scattering from particles in the lowermost stratosphere (LMS) have been studied by comparing in-situ aerosol samples from the IAGOS-CARIBIC passenger aircraft with vertical profiles of aerosol backscattering obtained from the CALIOP lidar aboard the CALIPSO satellite. Concentrations of the dominating fractions of the stratospheric aerosol, being sulphur and carbon, have been obtained from post-flight analysis of IAGOS-CARIBIC aerosol samples. This information together with literature data on black carbon concentrations were used to calculate the aerosol backscattering which subsequently is compared with measurements by CALIOP. Vertical optical profiles were taken in an altitude range of several kilometres from and above the northern hemispheric extratropical tropopause for the years 2006-2014. We find that the two vastly different measurement platforms yield different aerosol backscattering, especially close to the tropopause where the influence from tropospheric aerosol is strong. The best agreement is found when the LMS is affected by volcanism, i.e., at elevated aerosol loadings. At background conditions, best agreement is obtained some distance (>2 km) above the tropopause in winter and spring, i.e., at likewise elevated aerosol loadings from subsiding aerosol-rich stratospheric air. This is to our knowledge the first time the CALIPSO lidar measurements have been compared to in-situ long-term aerosol measurements. © 2019, The Author(s).
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    Author Correction: Enhanced tenacity of mycobacterial aerosols from necrotic neutrophils
    ([London] : Macmillan Publishers Limited, part of Springer Nature, 2020) Pfrommer, E.; Dreier, C.; Gabriel, G.; Dallenga, T.; Reimer, R.; Schepanski, K.; Scherließ, R.; Schaible, U.E.; Gutsmann, T.
    The original version of this Article contained errors within the affiliations section. Affiliation 4 was incorrectly given as ‘Leibniz Research Alliance INFECTIONS’21, Leipzig, Germany’. The correct affiliation is listed below: Leibniz Research Alliance INFECTIONS’21, Borstel, 23845, Germany Also, Affiliation 5 was incorrectly given as ‘German Center for Infection Research, TTU-TB, Borstel, 23845, Germany’. The correct affiliation is listed below: German Center for Infection Research (DZIF), Partner Site Hamburg-Lübeck-Borstel, Germany. Finally, the original HTML version of this Article omitted an affiliation for G. Gabriel. The correct affiliations for G. Gabriel are listed below: Heinrich Pette Institute, Leibniz Institute for Experimental Virology, Hamburg, 20251, Germany. Leibniz Research Alliance INFECTIONS’21, Borstel, 23845, Germany. German Center for Infection Research (DZIF), Partner Site Hamburg-Lübeck-Borstel, Germany. These errors have now been corrected in the PDF and HTML versions of the Article.