759 research outputs found
Optically addressable, integrative composite polymer microcapsules
PhDThe development of remotely addressable tools to encapsulate, store and deliver active materials to
living cells is a particularly challenging topic of material science. As drug delivery agents,
microcontainers not only require high mechanical stability or to be delivered at target cells, but they
should also possess efficient remotely addressable release mechanisms. Light responsive polyelectrolyte
capsules are well suited for such purposes. Capsules are constructed using the Layer‐by‐Layer technique
where oppositely charged polymers are alternatively deposited on a sacrificial template. The interest for
such microcapsules lays in their versatile composition and stimuli‐responsive properties, which can be
altered to suit specific needs.
The primary aim of this work was to develop polymeric capsules with efficient optically addressable
release mechanisms. Previous work on this topic revealed severe flaws in biological environments,
especially with regards to the high energy requirements necessary for laser‐induced release and in the
very limited knowledge of the fate of microcapsules in living cells. These issues were addressed by
developing alternative types of light‐responsive capsules and gaining better understanding of existing
ones. Three types of materials were used to sensitize microcapsules to the near‐UV, visible and near‐IR
spectral regions: (1) azobenzene‐substituted polymers, (2) gold nanoparticles and (3) photocatalytic
porphyrinoid dyes. Various methods were used for the characterization of microcapsules, including laser
scanning confocal microscopy, colloidal probe and standard atomic force microscopy, electron
microscopy, fluorescence spectrophotometry, UV‐visible spectroscopy and differential scanning
calorimetry. Shells were probed for their mechanical stability as well as encapsulation and release
behavior based on parameters such as: assembly strategies, shell deformability, permeability, thermal
response and response to laser irradiation.
This thesis begins with a brief introduction followed by an extensive literature review summarizing the
various topics relevant to the work. The materials and methods used in the investigations are catalogued
in Chapter 3 . Chapter 4 presents the destructive effects of pulsed UV lasing on polymeric microcapsules
and introduces azobenzene‐functionalized capsules with the ability to encapsulate macromolecules by
exposure to continuous wave UV light. Chapter 5 looks at the mechanical properties of capsules
functionalized with gold nanoparticles as well as their remote release capabilities under near‐IR
irradiation. While most of these studies were conducted ex vivo, Chapter 5 concludes with a summary of
studies performed in vitro, which demonstrates that it is not only possible to release substances in living
cells by light but that the latter also survive in the process. Finally, in Chapter 6, the assembly and light
induced destabilization of microcapsules containing porphyrinoid dyes is presented
In vitro cytotoxicity analysis of doxorubicin-loaded/superparamagnetic iron oxide colloidal nanoassemblies on MCF7 and NIH3T3 cell lines
Katerina Tomankova,1 Katerina Polakova,2 Klara Pizova,1 Svatopluk Binder,1 Marketa Havrdova,2 Mary Kolarova,2 Eva Kriegova,3 Jana Zapletalova,1 Lukas Malina,1 Jana Horakova,1 Jakub Malohlava,1 Argiris Kolokithas-Ntoukas,4 Aristides Bakandritsos,4 Hana Kolarova,1 Radek Zboril2 1Department of Medical Biophysics, Institute of Translation Medicine, Faculty of Medicine and Dentistry, 2Regional Centre of Advanced Technologies and Materials, Departments of Physical Chemistry and Experimental Physics, Faculty of Science, 3Department of Immunology, Faculty of Medicine and Dentistry, Palacky University, Olomouc, Czech Republic; 4Department of Materials Science, University of Patras, Patras, Greece Abstract: One of the promising strategies for improvement of cancer treatment is based on magnetic drug delivery systems, thus avoiding side effects of standard chemotherapies. Superparamagnetic iron oxide (SPIO) nanoparticles have ideal properties to become a targeted magnetic drug delivery contrast probes, named theranostics. We worked with SPIO condensed colloidal nanocrystal clusters (MagAlg) prepared through a new soft biomineralization route in the presence of alginate as the polymeric shell and loaded with doxorubicin (DOX). The aim of this work was to study the in vitro cytotoxicity of these new MagAlg–DOX systems on mouse fibroblast and breast carcinoma cell lines. For proper analysis and understanding of cell behavior after administration of MagAlg–DOX compared with free DOX, a complex set of in vitro tests, including production of reactive oxygen species, comet assay, cell cycle determination, gene expression, and cellular uptake, were utilized. It was found that the cytotoxic effect of MagAlg–DOX system is delayed compared to free DOX in both cell lines. This was attributed to the different mechanism of internalization of DOX and MagAlg–DOX into the cells, together with the fact that the drug is strongly bound on the drug nanocarriers. We discovered that nanoparticles can attenuate or even inhibit the effect of DOX, particularly in the tumor MCF7 cell line. This is a first comprehensive study on the cytotoxic effect of DOX-loaded SPIO compared with free DOX on healthy and cancer cell lines, as well as on the induced changes in gene expression. Keywords: DOX/SPIO nanocarriers, superparamagnetic iron oxide nanoparticles, doxorubicin, in vitro cytotoxicity 
Publisher Correction: Detection of a particle shower at the Glashow resonance with IceCube (Nature, (2021), 591, 7849, (220-224), 10.1038/s41586-021-03256-1)
In this Article, owing to an error in the production process, the affiliation of author L. Lu was incorrectly shown as ‘Karlsruhe Institute of Technology, Institute for Astroparticle Physics, Karlsruhe, Germany’ (affiliation 16) instead of ‘Department of Physics and Institute for Global Prominent Research, Chiba University, Chiba, Japan’ (affiliation 48). The original Article has been corrected online. *A list of authors and their affiliations appears online
Erratum: Search for photons with energies above 1018 eV using the hybrid detector of the Pierre Auger Observatory (Journal of Cosmology and Astroparticle Physics (2017) 4 (9) DOI: 10.1088/1475-7516/2017/04/009)
1 Exposure calculation Due to a mistake in the numerical integration following eq. (6.2) of the original article [1], the exposure shown in figure 5 of the original article was incorrect. The correct exposure is shown in figure 1. 2 Upper limits on the integral photon flux and fraction The incorrect exposure affects the calculation of the upper limits on the integral photon flux following eq. (6.1) of the original article. The correct values for the upper limits are 0.038, 0.010, 0.009, 0.008 and 0.007 km−2 sr−1 yr−1 for threshold energies of 1, 2, 3, 5 and 10 EeV. The correct values for the upper limits on the integral photon fraction subsequently derived are 0.14 %, 0.17 %, 0.42 %, 0.86 % and 2.9 % for the same threshold energies. 3 Author list The author list of this erratum also corrects a mistake made in the original article, where F. Zuccarello was missing and Z. Zong was listed twice
Bursaphelenchus hofmanni Braasch, 1998 associated with peat growth substrate in hops nurseries in the Czech Republic
To date, seven Bursaphelenchus species have been re- ported in surveys of the Czech Republic (Cˇ ermák et al., 2013). However, the occurrence of some species, such as Bursaphelenchus hofmanni Braasch, 1998, is limited to single detections in imported coniferous wood (un- publ. data in Braasch, 2001). During a survey to deter- mine pathogenic agents on hops (Humulus lupulus L.) conducted by State Phytosanitary Administration (CZ) in hops fields and nurseries in 2012, B. hofmanni was found in a mixture of peat and soil in a hops seedling nurs- ery in Žatec (Bohemia, Czech Republic). The occurrence of Bursaphelenchus species in non-woody plants or sub- strates has been previously reported for species of the fungivorus group, such as B. gonzalezi Loof, 1964, B. hunti Giblin & Kaya, 1983 and B. fungivorus Franklin & Hooper, 1962. Species belonging to the hofmanni group are often associated with wood products such as packag- ing material (Gu et al., 2006) and, to our knowledge, this is the first time that this species has been found associated with peat substrate and soil.
Nematodes were isolated from 60 g of peat substrate (3 parts peat to 1 part soil) associated with hops seedlings,
and extracted using the Baermann funnel technique. Specimens belonging to Bursaphelenchus were killed and fixed in hot 4% formalin and transferred to pure glycerin according to De Grisse (1969). Two mature females and two males were used to establish a culture maintained in Botryotinia fuckeliana, growing on 5% malt extract agar (MEA).
Nematode identification was confirmed by both mor- phological and molecular analyses (sequencing of the ITS, 18S and 28S rDNA loci). DNA was extracted as fol- lows: single specimens were collected into 20 μl of ex- traction buffer (10 mM Tris-HCl, pH 8.8; 1 mM EDTA; 1% Triton X-100 (v/v); 100 μg ml−1 Proteinase K) in a 1.5 ml Eppendorf tube. Each sample was ground using a micropestle and incubated at 55°C for 1 h and subse- quently at 95°C for 10 min. The mixture was used as a DNA template for PCR. The SSU, LSU and ITS regions of rDNA were amplified using a Phusion High Fidelity DNA polymerase (having 3′ → 5′ exonuclease activity) (NEB). GoTaq DNA polymerase (Promega) was added to a terminal 10 min/72°C elongation step to create an A- overhang for subsequent TA cloning
Multimessenger NuEM Alerts with AMON
The Astrophysical Multimessenger Observatory Network (AMON), has developed a real-time multi-messenger alert system. The system performs coincidence analyses of datasets from gammaray and neutrino detectors, making the Neutrino-Electromagnetic (NuEM) alert channel. For these analyses, AMON takes advantage of sub-threshold events, i.e., events that by themselves are not significant in the individual detectors. The main purpose of this channel is to search for gamma-ray counterparts of neutrino events. We will describe the different analyses that make-up this channel and present a selection of recent results.Article signat per 380 autors/es: R. Abbasi, M. Ackermann, J. Adams, J. A. Aguilar, M. Ahlers, M. Ahrens, C. Alispach, A. A. Alves Jr., N. M. Amin, R. An, K. Andeen, T. Anderson, G. Anton, C. Argüelles, Y. Ashida, S. Axani, X. Bai, A. Balagopal V., A. Barbano, S. W. Barwick, B. Bastian, V. Basu, S. Baur, R. Bay, J. J. Beatty, K.-H. Becker, J. Becker Tjus, C. Bellenghi, S. BenZvi, D. Berley, E. Bernardini, D. Z. Besson, G. Binder, D. Bindig, E. Blaufuss, S. Blot, M. Boddenberg, F. Bontempo, J. Borowka, S. Böser, O. Botner, J. Böttcher, E. Bourbeau, F. Bradascio, J. Braun, S. Bron, J. BrosteanKaiser, S. Browne, A. Burgman, R. T. Burley, R. S. Busse, M. A. Campana, E. G. Carnie-Bronca, C. Chen, D. Chirkin, K. Choi, B. A. Clark, K. Clark, L. Classen, A. Coleman, G. H. Collin, J. M. Conrad, P. Coppin, P. Correa, D. F. Cowen, R. Cross, C. Dappen, P. Dave, C. De Clercq, J. J. DeLaunay, H. Dembinski, K. Deoskar, S. De Ridder, A. Desai, P. Desiati, K. D. de Vries, G. de Wasseige, M. de With, T. DeYoung, S. Dharani, A. Diaz, J. C. Díaz-Vélez, M. Dittmer, H. Dujmovic, M. Dunkman, M. A. DuVernois, E. Dvorak, T. Ehrhardt, P. Eller, R. Engel, H. Erpenbeck, J. Evans, P. A. Evenson, A. R. Fazely, S. Fiedlschuster, A. T. Fienberg, K. Filimonov, C. Finley, L. Fischer, D. Fox , A. Franckowiak, E. Friedman, A. Fritz, P. Fürst, T. K. Gaisser, J. Gallagher, E. Ganster, A. Garcia, S. Garrappa, L. Gerhardt, A. Ghadimi, C. Glaser, T. Glauch, T. Glüsenkamp, A. Goldschmidt, J. G. Gonzalez, S. Goswami, D. Grant, T. Grégoire, S. Griswold, M. Gündüz, C. Günther, C. Haack, A. Hallgren, R. Halliday, L. Halve, F. Halzen, M. Ha Minh, K. Hanson, J. Hardin38, A. A. Harnisch, A. Haungs, S. Hauser, D. Hebecker, K. Helbing, F. Henningsen, E. C. Hettinger, S. Hickford, J. Hignight, C. Hill, G. C. Hill, K. D. Hoffman, R. Hoffmann, T. Hoinka, B. Hokanson-Fasig, K. Hoshina, F. Huang, M. Huber, T. Huber, K. Hultqvist, M. Hünnefeld, R. Hussain, S. In, N. Iovine, A. Ishihara, M. Jansson, G. S. Japaridze, M. Jeong, B. J. P. Jones, D. Kang, W. Kang, X. Kang, A. Kappes, D. Kappesser, T. Karg, M. Karl, A. Karle, U. Katz, M. Kauer, M. Kellermann, J. L. Kelley, A. Kheirandish, K. Kin, T. Kintscher, J. Kiryluk, S. R. Klein, R. Koirala, H. Kolanoski, T. Kontrimas, L. Köpke, C. Kopper, S. Kopper, D. J. Koskinen, P. Koundal, M. Kovacevich, M. Kowalski, T. Kozynets, E. Kun, N. Kurahashi, N. Lad, C. Lagunas Gualda, J. L. Lanfranchi, M. J. Larson, F. Lauber, J. P. Lazar, J. W. Lee, K. Leonard, A. Leszczyńska, Y. Li, M. Lincetto, Q. R. Liu, M. Liubarska, E. Lohfink, C. J. Lozano Mariscal, L. Lu, F. Lucarelli, A. Ludwig, W. Luszczak, Y. Lyu, W. Y. Ma, J. Madsen, K. B. M. Mahn, Y. Makino, S. Mancina, I. C. Mariş, R. Maruyama, K. Mase, T. McElroy, F. McNally, J. V. Mead, K. Meagher, A. Medina, M. Meier, S. Meighen-Berger, J. Micallef, D. Mockler, T. Montaruli, R. W. Moore, R. Morse, M. Moulai, R. Naab, R. Nagai, U. Naumann, J. Necker, L. V. Nguyên, H. Niederhausen, S. C. Nowicki, D. R. Nygren, A. Obertacke Pollmann, M. Oehler, A. Olivas, E. O’Sullivan, H. Pandya, D. V. Pankova, N. Park, G. K. Parker, E. N. Paudel, L. Paul, C. Pérez de los Heros, L. Peters, J. Peterson, S. Philippen, D. Pieloth, S. Pieper, M. Pittermann, A. Pizzuto, M. Plum, Y. Popovych, A. Porcelli, M. Prado Rodriguez, P. B. Price, B. Pries, G. T. Przybylski, C. Raab, A. Raissi, M. Rameez, K. Rawlins, I. C. Rea, A. Rehman, P. Reichherzer, R. Reimann, G. Renzi, E. Resconi, S. Reusch, W. Rhode, M. Richman, B. Riedel, E. J. Roberts, S. Robertson , G. Roellinghoff, M. Rongen, C. Rott , T. Ruhe, D. Ryckbosch, D. Rysewyk Cantu, I. Safa, J. Saffer, S. E. Sanchez Herrera, A. Sandrock, J. Sandroos, M. Santander, S. Sarkar, S. Sarkar, K. Satalecka, M. Scharf, M. Schaufel, H. Schieler, S. Schindler, P. Schlunder, T. Schmidt, A. Schneider, J. Schneider, F. G. Schröder, L. Schumacher, G. Schwefer, S. Sclafani, D. Seckel, S. Seunarine, A. Sharma, S. Shefali, M. Silva, B. Skrzypek, B. Smithers, R. Snihur, J. Soedingrekso, D. Soldin, C. Spannfellner, G. M. Spiczak, C. Spiering, J. Stachurska, M. Stamatikos, T. Stanev, R. Stein, J. Stettner, A. Steuer, T. Stezelberger, T. Stürwald, T. Stuttard, G. W. Sullivan, I. Taboada, F. Tenholt, S. Ter-Antonyan, S. Tilav, F. Tischbein, K. Tollefson, L. Tomankova, C. Tönnis, S. Toscano, D. Tosi, A. Trettin, M. Tselengidou, C. F. Tung, A. Turcati, R. Turcotte, C. F. Turley, J. P. Twagirayezu, B. Ty, M. A. Unland Elorrieta, N. Valtonen-Mattila, J. Vandenbroucke, N. van Eijndhoven, D. Vannerom, J. van Santen, S. Verpoest, M. Vraeghe, C. Walck, T. B. Watson, C. Weaver, P. Weigel, A. Weindl, M. J. Weiss, J. Weldert, C. Wendt, J. Werthebach, M. Weyrauch, N. Whitehorn, C. H. Wiebusch, D. R. Williams, M. Wolf, K. Woschnagg, G. Wrede, J. Wulff, X. W. Xu, Y. Xu, J. P. Yanez, S. Yoshida, S. Yu, T. Yuan, Z. ZhangPostprint (published version
Multimessenger NuEM Alerts with AMON
The Astrophysical Multimessenger Observatory Network (AMON), has developed a real-time multi-messenger alert system. The system performs coincidence analyses of datasets from gammaray and neutrino detectors, making the Neutrino-Electromagnetic (NuEM) alert channel. For these analyses, AMON takes advantage of sub-threshold events, i.e., events that by themselves are not significant in the individual detectors. The main purpose of this channel is to search for gamma-ray counterparts of neutrino events. We will describe the different analyses that make-up this channel and present a selection of recent results.Article signat per 380 autors/es: R. Abbasi, M. Ackermann, J. Adams, J. A. Aguilar, M. Ahlers, M. Ahrens, C. Alispach, A. A. Alves Jr., N. M. Amin, R. An, K. Andeen, T. Anderson, G. Anton, C. Argüelles, Y. Ashida, S. Axani, X. Bai, A. Balagopal V., A. Barbano, S. W. Barwick, B. Bastian, V. Basu, S. Baur, R. Bay, J. J. Beatty, K.-H. Becker, J. Becker Tjus, C. Bellenghi, S. BenZvi, D. Berley, E. Bernardini, D. Z. Besson, G. Binder, D. Bindig, E. Blaufuss, S. Blot, M. Boddenberg, F. Bontempo, J. Borowka, S. Böser, O. Botner, J. Böttcher, E. Bourbeau, F. Bradascio, J. Braun, S. Bron, J. BrosteanKaiser, S. Browne, A. Burgman, R. T. Burley, R. S. Busse, M. A. Campana, E. G. Carnie-Bronca, C. Chen, D. Chirkin, K. Choi, B. A. Clark, K. Clark, L. Classen, A. Coleman, G. H. Collin, J. M. Conrad, P. Coppin, P. Correa, D. F. Cowen, R. Cross, C. Dappen, P. Dave, C. De Clercq, J. J. DeLaunay, H. Dembinski, K. Deoskar, S. De Ridder, A. Desai, P. Desiati, K. D. de Vries, G. de Wasseige, M. de With, T. DeYoung, S. Dharani, A. Diaz, J. C. Díaz-Vélez, M. Dittmer, H. Dujmovic, M. Dunkman, M. A. DuVernois, E. Dvorak, T. Ehrhardt, P. Eller, R. Engel, H. Erpenbeck, J. Evans, P. A. Evenson, A. R. Fazely, S. Fiedlschuster, A. T. Fienberg, K. Filimonov, C. Finley, L. Fischer, D. Fox , A. Franckowiak, E. Friedman, A. Fritz, P. Fürst, T. K. Gaisser, J. Gallagher, E. Ganster, A. Garcia, S. Garrappa, L. Gerhardt, A. Ghadimi, C. Glaser, T. Glauch, T. Glüsenkamp, A. Goldschmidt, J. G. Gonzalez, S. Goswami, D. Grant, T. Grégoire, S. Griswold, M. Gündüz, C. Günther, C. Haack, A. Hallgren, R. Halliday, L. Halve, F. Halzen, M. Ha Minh, K. Hanson, J. Hardin38, A. A. Harnisch, A. Haungs, S. Hauser, D. Hebecker, K. Helbing, F. Henningsen, E. C. Hettinger, S. Hickford, J. Hignight, C. Hill, G. C. Hill, K. D. Hoffman, R. Hoffmann, T. Hoinka, B. Hokanson-Fasig, K. Hoshina, F. Huang, M. Huber, T. Huber, K. Hultqvist, M. Hünnefeld, R. Hussain, S. In, N. Iovine, A. Ishihara, M. Jansson, G. S. Japaridze, M. Jeong, B. J. P. Jones, D. Kang, W. Kang, X. Kang, A. Kappes, D. Kappesser, T. Karg, M. Karl, A. Karle, U. Katz, M. Kauer, M. Kellermann, J. L. Kelley, A. Kheirandish, K. Kin, T. Kintscher, J. Kiryluk, S. R. Klein, R. Koirala, H. Kolanoski, T. Kontrimas, L. Köpke, C. Kopper, S. Kopper, D. J. Koskinen, P. Koundal, M. Kovacevich, M. Kowalski, T. Kozynets, E. Kun, N. Kurahashi, N. Lad, C. Lagunas Gualda, J. L. Lanfranchi, M. J. Larson, F. Lauber, J. P. Lazar, J. W. Lee, K. Leonard, A. Leszczyńska, Y. Li, M. Lincetto, Q. R. Liu, M. Liubarska, E. Lohfink, C. J. Lozano Mariscal, L. Lu, F. Lucarelli, A. Ludwig, W. Luszczak, Y. Lyu, W. Y. Ma, J. Madsen, K. B. M. Mahn, Y. Makino, S. Mancina, I. C. Mariş, R. Maruyama, K. Mase, T. McElroy, F. McNally, J. V. Mead, K. Meagher, A. Medina, M. Meier, S. Meighen-Berger, J. Micallef, D. Mockler, T. Montaruli, R. W. Moore, R. Morse, M. Moulai, R. Naab, R. Nagai, U. Naumann, J. Necker, L. V. Nguyên, H. Niederhausen, S. C. Nowicki, D. R. Nygren, A. Obertacke Pollmann, M. Oehler, A. Olivas, E. O’Sullivan, H. Pandya, D. V. Pankova, N. Park, G. K. Parker, E. N. Paudel, L. Paul, C. Pérez de los Heros, L. Peters, J. Peterson, S. Philippen, D. Pieloth, S. Pieper, M. Pittermann, A. Pizzuto, M. Plum, Y. Popovych, A. Porcelli, M. Prado Rodriguez, P. B. Price, B. Pries, G. T. Przybylski, C. Raab, A. Raissi, M. Rameez, K. Rawlins, I. C. Rea, A. Rehman, P. Reichherzer, R. Reimann, G. Renzi, E. Resconi, S. Reusch, W. Rhode, M. Richman, B. Riedel, E. J. Roberts, S. Robertson , G. Roellinghoff, M. Rongen, C. Rott , T. Ruhe, D. Ryckbosch, D. Rysewyk Cantu, I. Safa, J. Saffer, S. E. Sanchez Herrera, A. Sandrock, J. Sandroos, M. Santander, S. Sarkar, S. Sarkar, K. Satalecka, M. Scharf, M. Schaufel, H. Schieler, S. Schindler, P. Schlunder, T. Schmidt, A. Schneider, J. Schneider, F. G. Schröder, L. Schumacher, G. Schwefer, S. Sclafani, D. Seckel, S. Seunarine, A. Sharma, S. Shefali, M. Silva, B. Skrzypek, B. Smithers, R. Snihur, J. Soedingrekso, D. Soldin, C. Spannfellner, G. M. Spiczak, C. Spiering, J. Stachurska, M. Stamatikos, T. Stanev, R. Stein, J. Stettner, A. Steuer, T. Stezelberger, T. Stürwald, T. Stuttard, G. W. Sullivan, I. Taboada, F. Tenholt, S. Ter-Antonyan, S. Tilav, F. Tischbein, K. Tollefson, L. Tomankova, C. Tönnis, S. Toscano, D. Tosi, A. Trettin, M. Tselengidou, C. F. Tung, A. Turcati, R. Turcotte, C. F. Turley, J. P. Twagirayezu, B. Ty, M. A. Unland Elorrieta, N. Valtonen-Mattila, J. Vandenbroucke, N. van Eijndhoven, D. Vannerom, J. van Santen, S. Verpoest, M. Vraeghe, C. Walck, T. B. Watson, C. Weaver, P. Weigel, A. Weindl, M. J. Weiss, J. Weldert, C. Wendt, J. Werthebach, M. Weyrauch, N. Whitehorn, C. H. Wiebusch, D. R. Williams, M. Wolf, K. Woschnagg, G. Wrede, J. Wulff, X. W. Xu, Y. Xu, J. P. Yanez, S. Yoshida, S. Yu, T. Yuan, Z. ZhangPostprint (published version
Erratum: Search for photons with energies above 1018 eV using the hybrid detector of the Pierre Auger Observatory
Exposure calculation Due to a mistake in the numerical integration following eq. (6.2) of the original article [1], the exposure shown in figure 5 of the original article was incorrect. The correct exposure is shown in figure 1. 2 Upper limits on the integral photon flux and fraction The incorrect exposure affects the calculation of the upper limits on the integral photon flux following eq. (6.1) of the original article. The correct values for the upper limits are 0.038, 0.010, 0.009, 0.008 and 0.007 km−2 sr−1 yr−1 for threshold energies of 1, 2, 3, 5 and 10 EeV. The correct values for the upper limits on the integral photon fraction subsequently derived are 0.14 %, 0.17 %, 0.42 %, 0.86 % and 2.9 % for the same threshold energies. 3 Author list The author list of this erratum also corrects a mistake made in the original article, where F. Zuccarello was missing and Z. Zong was listed twice
Evidence for a mixed mass composition at the ‘ankle’ in the cosmic-ray spectrum
We report a first measurement for ultrahigh energy cosmic rays of the correlation between the depth of shower maximum and the signal in the water Cherenkov stations of air-showers registered simultaneously by the fluorescence and the surface detectors of the Pierre Auger Observatory. Such a correlation measurement is a unique feature of a hybrid air-shower observatory with sensitivity to both the electromagnetic and muonic components. It allows an accurate determination of the spread of primary masses in the cosmic-ray flux. Up till now, constraints on the spread of primary masses have been dominated by systematic uncertainties. The present correlation measurement is not affected by systematics in the measurement of the depth of shower maximum or the signal in the water Cherenkov stations. The analysis relies on general characteristics of air showers and is thus robust also with respect to uncertainties in hadronic event generators. The observed correlation in the energy range around the ‘ankle’ at lg(E/eV)=18.5–19.0lg(E/eV)=18.5–19.0 differs significantly from expectations for pure primary cosmic-ray compositions. A light composition made up of proton and helium only is equally inconsistent with observations. The data are explained well by a mixed composition including nuclei with mass A>4A>4. Scenarios such as the proton dip model, with almost pure compositions, are thus disfavored as the sole explanation of the ultrahigh-energy cosmic-ray flux at Earth
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