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1. Imaging of single barium atoms in a second matrix site in solid xenon for barium tagging in a $^{136}$Xe double beta decay experiment

Author

Yvaine, M., Fairbank, D., Soderstrom, J., Taylor, C., Stanley, J., Walton, T., Chambers, C., Iverson, A., Fairbank, W., Kharusi, S. Al, Amy, A., Angelico, E., Anker, A., Arnquist, I. J., Atencio, A., Bane, J., Belov, V., Bernard, E. P., Bhatta, T., Bolotnikov, A., Breslin, J., Breur, P. A., Brodsky, J. P., Brown, E., Brunner, T., Caden, E., Cao, G. F., Cesmecioglu, D., Chambers, E., Chana, B., Chernyak, D., Chiu, M., Collister, R., Cvitan, M., Daniels, T., Darroch, L., DeVoe, R., di Vacri, M. L., Dolinski, M. J., Eckert, B., Elbeltagi, M., Elmansali, R., Fatemighomi, N., Foust, B., Fu, Y. S., Gallacher, D., Gallice, N., Giacomini, G., Gillis, W., Gingras, C., Gornea, R., Gratta, G., Hardy, C. A., Hedges, S., Hein, E., Holt, J. D., Hoppe, E. W., Karelin, A., Keblbeck, D., Kotov, I., Kuchenkov, A., Kumar, K. S., Kwiatkowski, A. A., Larson, A., Latif, M. B., Leach, K. G., Lennarz, A., Leonard, D. S., Lewis, H., Li, G., Li, Z., Licciardi, C., Lindsay, R., MacLellan, R., Majidi, S., Malbrunot, C., Masbou, J., McMichael, K., Peregrina, M. Medina, Moe, M., Mong, B., Moore, D. C., Natzke, C. R., Ngwadla, X. E., Ni, K., Nolan, A., Nowicki, S. C., Ondze, J. C. Nzobadila, Odian, A., Orrell, J. L., Ortega, G. S., Overman, C. T., Pagani, L., Smalley, H. Peltz, Perna, A., Pocar, A., Radeka, V., Raguzin, E., Rasiwala, H., Ray, D., Rescia, S., Richardson, G., Ross, R., Rowson, P. C., Saldanha, R., Sangiorgio, S., Schwartz, S., Sekula, S., Si, L., Soma, A. K., Spadoni, F., Stekhanov, V., Sun, X. L., Thibado, S., Tidball, A., Totev, T., Triambak, S., Tsang, T., Tyuka, O. A., van Bruggen, E., Vidal, M., Walent, M., Wamba, K., Wang, H. W., Wang, Q. D., Wang, W., Wang, Y. G., Watts, M., Wehrfritz, M., Wen, L. J., Wichoski, U., Wilde, S., Worcester, M., Xu, H., Yang, L., Yu, M., and Zeldovich, O.

Subjects
Physics - Atomic Physics, High Energy Physics - Experiment, Nuclear Experiment
Abstract

Neutrinoless double beta decay is one of the most sensitive probes for new physics beyond the Standard Model of particle physics. One of the isotopes under investigation is $^{136}$Xe, which would double beta decay into $^{136}$Ba. Detecting the single $^{136}$Ba daughter provides a sort of ultimate tool in the discrimination against backgrounds. Previous work demonstrated the ability to perform single atom imaging of Ba atoms in a single-vacancy site of a solid xenon matrix. In this paper, the effort to identify signal from individual barium atoms is extended to Ba atoms in a hexa-vacancy site in the matrix and is achieved despite increased photobleaching in this site. Abrupt fluorescence turn-off of a single Ba atom is also observed. Significant recovery of fluorescence signal lost through photobleaching is demonstrated upon annealing of Ba deposits in the Xe ice. Following annealing, it is observed that Ba atoms in the hexa-vacancy site exhibit antibleaching while Ba atoms in the tetra-vacancy site exhibit bleaching. This may be evidence for a matrix site transfer upon laser excitation. Our findings offer a path of continued research toward tagging of Ba daughters in all significant sites in solid xenon., Comment: 9 pages, 8 figures

Published
2024

2. Supernova electron-neutrino interactions with xenon in the nEXO detector

Author

nEXO Collaboration, Hedges, S., Kharusi, S. Al, Angelico, E., Brodsky, J. P., Richardson, G., Wilde, S., Amy, A., Anker, A., Arnquist, I. J., Arsenault, P., Atencio, A., Badhrees, I., Bane, J., Belov, V., Bernard, E. P., Bhatta, T., Bolotnikov, A., Breslin, J., Breur, P. A., Brown, E., Brunner, T., Caden, E., Cao, G. F., Cao, L. Q., Cesmecioglu, D., Chambers, E., Chana, B., Charlebois, S. A., Chernyak, D., Chiu, M., Collister, R., Cvitan, M., Dalmasson, J., Daniels, T., Darroch, L., DeVoe, R., di Vacri, M. L., Ding, Y. Y., Dolinski, M. J., Eckert, B., Elbeltagi, M., Elmansali, R., Fabris, L., Fairbank, W., Farine, J., Fatemighomi, N., Foust, B., Fu, Y. S., Gallacher, D., Gallice, N., Gillis, W., Goeldi, D., Gorham, A., Gornea, R., Gratta, G., Guan, Y. D., Hardy, C. A., Heffner, M., Hein, E., Holt, J. D., Hoppe, E. W., House, A., Hunt, W., Iverson, A., Kachru, P., Karelin, A., Keblbeck, D., Kuchenkov, A., Kumar, K. S., Larson, A., Latif, M. B., Leach, K. G., Lenardo, B. G., Leonard, D. S., Lewis, H., Li, G., Li, Z., Licciardi, C., Lindsay, R., MacLellan, R., Majidi, S., Malbrunot, C., Martel-Dion, P., Masbou, J., McMichael, K., Medina-Peregrina, M., Mong, B., Moore, D. C., Nattress, J., Natzke, C. R., Ngwadla, X. E., Ni, K., Nolan, A., Nowicki, S. C., Ondze, J. C. Nzobadila, Orrell, J. L., Ortega, G. S., Overman, C. T., Pagani, L., Smalley, H. Peltz, Peña-Perez, A., Perna, A., Piepke, A., Franco, T. Pinto, Pocar, A., Pratte, J. -F., Rasiwala, H., Ray, D., Raymond, K., Rescia, S., Riot, V., Ross, R., Saldanha, R., Sangiorgio, S., Schwartz, S., Sekula, S., Soderstrom, J., Soma, A. K., Spadoni, F., Sun, X. L., Thibado, S., Tidball, A., Totev, T., Triambak, S., Tsang, R. H. M., Tyuka, O. A., van Bruggen, E., Vidal, M., Viel, S., Walent, M., Wang, Q. D., Wang, W., Wang, Y. G., Watts, M., Wehrfritz, M., Wei, W., Wen, L. J., Wichoski, U., Wu, X. M., Xu, H., Yang, H. B., Yang, L., Yu, M., Yvaine, M., Zeldovich, O., and Zhao, J.

Subjects
High Energy Physics - Phenomenology, High Energy Physics - Experiment, Nuclear Theory
Abstract

Electron-neutrino charged-current interactions with xenon nuclei were modeled in the nEXO neutrinoless double-$\beta$ decay detector (~5 metric ton, 90% ${}^{136}$Xe, 10% ${}^{134}$Xe) to evaluate its sensitivity to supernova neutrinos. Predictions for event rates and detectable signatures were modeled using the Model of Argon Reaction Low Energy Yields (MARLEY) event generator. We find good agreement between MARLEY's predictions and existing theoretical calculations of the inclusive cross sections at supernova neutrino energies. The interactions modeled by MARLEY were simulated within the nEXO simulation framework and were run through an example reconstruction algorithm to determine the detector's efficiency for reconstructing these events. The simulated data, incorporating the detector response, were used to study the ability of nEXO to reconstruct the incident electron-neutrino spectrum and these results were extended to a larger xenon detector of the same isotope enrichment. We estimate that nEXO will be able to observe electron-neutrino interactions with xenon from supernovae as far as 5-8 kpc from Earth, while the ability to reconstruct incident electron-neutrino spectrum parameters from observed interactions in nEXO is limited to closer supernovae., Comment: 17 pages, 16 figures

Published
2024
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3. An integrated online radioassay data storage and analytics tool for nEXO

Author

Tsang, R. H. M., Piepke, A., Kharusi, S. Al, Angelico, E., Arnquist, I. J., Atencio, A., Badhrees, I., Bane, J., Belov, V., Bernard, E. P., Bhat, A., Bhatta, T., Bolotnikov, A., Breur, P. A., Brodsky, J. P., Brown, E., Brunner, T., Caden, E., Cao, G. F., Cao, L. Q., Cesmecioglu, D., Chambers, C., Chambers, E., Chana, B., Charlebois, S. A., Chernyak, D., Chiu, M., Cleveland, B., Cohen, J. R., Collister, R., Cvitan, M., Dalmasson, J., Darroch, L., Deslandes, K., DeVoe, R., di Vacri, M. L., Ding, Y. Y., Dolinski, M. J., Echevers, J., Eckert, B., Elbeltagi, M., Elmansali, R., Fabris, L., Fairbank, W., Farine, J., Fu, Y. S., Gallacher, D., Gallina, G., Gautam, P., Giacomini, G., Gillis, W., Gingras, C., Goeldi, D., Gornea, R., Gratta, G., Guan, Y. D., Hardy, C. A., Hedges, S., Heffner, M., Hein, E., Holt, J., Hoppe, E. W., House, A., Hunt, W., Iverson, A., Jamil, A., Jiang, X. S., Karelin, A., Kaufman, L. J., Kotov, I., Krücken, R., Kuchenkov, A., Kumar, K. S., Larson, A., Leach, K. G., Lenardo, B. G., Leonard, D. S., Li, G., Li, S., Li, Z., Licciardi, C., Lindsay, R., MacLellan, R., Mahtab, M., Majidi, S., Malbrunot, C., Martel-Dion, P., Masbou, J., Massacret, N., McMichael, K., Mong, B., Moore, D. C., Murray, K., Nattress, J., Natzke, C. R., Ngwadla, X. E., Ni, K., Nolan, A., Nowicki, S. C., Ondze, J. C. Nzobadila, Orrell, J. L., Ortega, G. S., Overman, C. T., Peltz-Smalley, H., Perna, A., Franco, T. Pinto, Pocar, A., Pratte, J. -F., Radeka, V., Raguzin, E., Rasiwala, H., Ray, D., Rebeiro, B., Rescia, S., Retière, F., Richardson, G., Ringuette, J., Riot, V., Rowson, P. C., Roy, N., Rudolph, L., Saldanha, R., Sangiorgio, S., Schwartz, S., Soderstrom, J., Soma, A. K., Spadoni, F., Stekhanov, V., Sun, X. L., Barakoohi, E. Teimoori, Thibado, S., Tidball, A., Totev, T., Triambak, S., Tsang, T., Tyuka, O. A., Underwood, R., van Bruggen, E., Veeraraghavan, V., Vidal, M., Viel, S., Walent, M., Wamba, K., Wang, Q. D., Wang, W., Wang, Y. G., Watts, M., Wei, W., Wen, L. J., Wichoski, U., Wilde, S., Worcester, M., Wu, S., Wu, X. M., Yang, H., Yang, L., Yvaine, M., Zeldovich, O., Zhao, J., and Ziegler, T.

Subjects
Physics - Instrumentation and Detectors, Nuclear Experiment
Abstract

Large-scale low-background detectors are increasingly used in rare-event searches as experimental collaborations push for enhanced sensitivity. However, building such detectors, in practice, creates an abundance of radioassay data especially during the conceptual phase of an experiment when hundreds of materials are screened for radiopurity. A tool is needed to manage and make use of the radioassay screening data to quantitatively assess detector design options. We have developed a Materials Database Application for the nEXO experiment to serve this purpose. This paper describes this database, explains how it functions, and discusses how it streamlines the design of the experiment.

Published
2023

4. Performance of novel VUV-sensitive Silicon Photo-Multipliers for nEXO

Author

Gallina, G., Guan, Y., Retiere, F., Cao, G., Bolotnikov, A., Kotov, I., Rescia, S., Soma, A. K., Tsang, T., Darroch, L., Brunner, T., Bolster, J., Cohen, J. R., Franco, T. Pinto, Gillis, W. C., Smalley, H. Peltz, Thibado, S., Pocar, A., Bhat, A., Jamil, A., Moore, D. C., Adhikari, G., Kharusi, S. Al, Angelico, E., Arnquist, I. J., Arsenault, P., Badhrees, I., Bane, J., Belov, V., Bernard, E. P., Bhatta, T., Brodsky, J. P., Brown, E., Caden, E., Cao, L., Chambers, C., Chana, B., Charlebois, S. A., Chernyak, D., Chiu, M., Cleveland, B., Collister, R., Cvitan, M., Dalmasson, J., Daniels, T., Deslandes, K., DeVoe, R., di Vacri, M. L., Ding, Y., Dolinski, M. J., Dragone, A., Echevers, J., Eckert, B., Elbeltagi, M., Fabris, L., Fairbank, W., Farine, J., Fu, Y. S., Gallacher, D., Gautam, P., Giacomini, G., Gingras, C., Goeldi, D., Gornea, R., Gratta, G., Hardy, C. A., Hedges, S., Heffner, M., Hein, E., Holt, J., Hoppe, E. W., Hößl, J., House, A., Hunt, W., Iverson, A., Jiang, X. S., Karelin, A., Kaufman, L. J., Krücken, R., Kuchenkov, A., Kumar, K. S., Larson, A., Leach, K. G., Lenardo, B. G., Leonard, D. S., Lessard, G., Li, G., Li, S., Li, Z., Licciardi, C., Lindsay, R., MacLellan, R., Mahtab, M., Majidi, S., Malbrunot, C., Margetak, P., Martel-Dion, P., Martin, L., Masbou, J., Massacret, N., McMichael, K., Mong, B., Murray, K., Nattress, J., Natzke, C. R., Ngwadla, X. E., Ondze, J. C. Nzobadila, Odian, A., Orrell, J. L., Ortega, G. S., Overman, C. T., Parent, S., Perna, A., Piepke, A., Pletskova, N., Pratte, J. F., Radeka, V., Raguzin, E., Ramonnye, G. J., Rao, T., Rasiwala, H., Raymond, K., Rebeiro, B. M., Richardson, G., Ringuette, J., Riot, V., Rossignol, T., Rowson, P. C., Rudolph, L., Saldanha, R., Sangiorgio, S., Shang, X., Spadoni, F., Stekhanov, V., Sun, X. L., Tidball, A., Totev, T., Triambak, S., Tsang, R. H. M., Tyuka, O. A., Vachon, F., Vidal, M., Viel, S., Visser, G., Wagenpfeil, M., Walent, M., Wamba, K., Wang, Q., Wang, W., Wang, Y., Watts, M., Wei, W., Wen, L. J., Wichoski, U., Wilde, S., Worcester, M., Wu, W. H., Wu, X., Xie, L., Yan, W., Yang, H., Yang, L., Zeldovich, O., Zhao, J., and Ziegler, T.

Subjects
Physics - Instrumentation and Detectors
Abstract

Liquid xenon time projection chambers are promising detectors to search for neutrinoless double beta decay (0$\nu \beta \beta$), due to their response uniformity, monolithic sensitive volume, scalability to large target masses, and suitability for extremely low background operations. The nEXO collaboration has designed a tonne-scale time projection chamber that aims to search for 0$\nu \beta \beta$ of \ce{^{136}Xe} with projected half-life sensitivity of $1.35\times 10^{28}$~yr. To reach this sensitivity, the design goal for nEXO is $\leq$1\% energy resolution at the decay $Q$-value ($2458.07\pm 0.31$~keV). Reaching this resolution requires the efficient collection of both the ionization and scintillation produced in the detector. The nEXO design employs Silicon Photo-Multipliers (SiPMs) to detect the vacuum ultra-violet, 175 nm scintillation light of liquid xenon. This paper reports on the characterization of the newest vacuum ultra-violet sensitive Fondazione Bruno Kessler VUVHD3 SiPMs specifically designed for nEXO, as well as new measurements on new test samples of previously characterised Hamamatsu VUV4 Multi Pixel Photon Counters (MPPCs). Various SiPM and MPPC parameters, such as dark noise, gain, direct crosstalk, correlated avalanches and photon detection efficiency were measured as a function of the applied over voltage and wavelength at liquid xenon temperature (163~K). The results from this study are used to provide updated estimates of the achievable energy resolution at the decay $Q$-value for the nEXO design.

Published
2022
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5. Development of a $^{127}$Xe calibration source for nEXO

Author

Lenardo, B. G., Hardy, C. A., Tsang, R. H. M., Ondze, J. C. Nzobadila, Piepke, A., Triambak, S., Jamil, A., Adhikari, G., Kharusi, S. Al, Angelico, E., Arnquist, I. J., Belov, V., Bernard, E. P., Bhat, A., Bhatta, T., Bolotnikov, A., Breur, P. A., Brodsky, J. P., Brown, E., Brunner, T., Caden, E., Cao, G. F., Cao, L., Chana, B., Charlebois, S. A., Chernyak, D., Chiu, M., Cohen, J. R., Collister, R., Dalmasson, J., Daniels, T., Darroch, L., DeVoe, R., di Vacri, M. L., Ding, Y. Y., Dolinski, M. J., Echevers, J., Eckert, B., Elbeltagi, M., Fabris, L., Fairbank, D., Fairbank, W., Farine, J., Fu, Y. S., Gallina, G., Gautam, P., Giacomini, G., Gillis, W., Gingras, C., Gornea, R., Gratta, G., Harouaka, K., Heffner, M., Hein, E., Hößl, J., House, A., Iverson, A., Jiang, X. S., Karelin, A., Kaufman, L. J., Krücken, R., Kuchenkov, A., Kumar, K. S., Larson, A., Leach, K. G., Leonard, D. S., Li, G., Li, S., Li, Z., Licciardi, C., Lindsay, R., MacLellan, R., Masbou, J., McMichael, K., Peregrina, M. Medina, Mong, B., Moore, D. C., Murray, K., Nattress, J., Natzke, C. R., Ngwadla, X. E., Ni, K., Ning, Z., Orrell, J. L., Ortega, G. S., Ostrovskiy, I., Overman, C. T., Perna, A., Franco, T. Pinto, Pocar, A., Pratte, J. F., Priel, N., Raguzin, E., Ramonnye, G. J., Rasiwala, H., Raymond, K., Richardson, G., Richman, M., Ringuette, J., Rowson, P. C., Saldanha, R., Sangiorgio, S., Shang, X., Soma, A. K., Spadoni, F., Stekhanov, V., Sun, X. L., Thibado, S., Tidball, A., Todd, J., Totev, T., Tyuka, O. A., Vachon, F., Veeraraghavan, V., Viel, S., Wamba, K., Wang, Y., Wang, Q., Wei, W., Wen, L. J., Wichoski, U., Wilde, S., Wu, W. H., Yan, W., Yang, L., Zeldovich, O., Zhao, J., and Ziegler, T.

Subjects
Physics - Instrumentation and Detectors, Nuclear Experiment
Abstract

We study a possible calibration technique for the nEXO experiment using a $^{127}$Xe electron capture source. nEXO is a next-generation search for neutrinoless double beta decay ($0\nu\beta\beta$) that will use a 5-tonne, monolithic liquid xenon time projection chamber (TPC). The xenon, used both as source and detection medium, will be enriched to 90% in $^{136}$Xe. To optimize the event reconstruction and energy resolution, calibrations are needed to map the position- and time-dependent detector response. The 36.3 day half-life of $^{127}$Xe and its small $Q$-value compared to that of $^{136}$Xe $0\nu\beta\beta$ would allow a small activity to be maintained continuously in the detector during normal operations without introducing additional backgrounds, thereby enabling in-situ calibration and monitoring of the detector response. In this work we describe a process for producing the source and preliminary experimental tests. We then use simulations to project the precision with which such a source could calibrate spatial corrections to the light and charge response of the nEXO TPC., Comment: 24 pages, 16 figures

Published
2022
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9. Stroke Etiology Modifies the Effect of Endovascular Treatment in Acute Stroke

Author

Tiedt, Steffen, Herzberg, Moriz, Küpper, Clemens, Feil, Katharina, Kellert, Lars, Dorn, Franziska, Liebig, Thomas, Alegiani, Anna, Dichgans, Martin, Wollenweber, Frank A., Alber, B., Bangard, C., Berrouschot, J., Bode, F.J., Boeckh-Behrens, T., Bohner, G., Bormann, A., Braun, M., Eckert, B., Fiehler, J., Flottmann, F., Gerloff, C., Hamann, G.F., Henn, K.H., Kastrup, A., Kraemer, C., Krause, L., Lehm, M., Liman, J., Lowens, S., Mpotsaris, A., Nolte, C.H., Papanagiotou, P., Petersen, M., Petzold, G.C., Pfeilschifter, W., Psychogios, M.N., Reich, A., von Rennenberg, R., Röther, J., Schäfer, J.H., Siebert, E., Siedow, A., Solymosi, L., Thomalla, G., Thonke, S., Wagner, M., Wunderlich, S., and Zweynert, S.

Published
2020
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10. Performance of novel VUV-sensitive Silicon Photo-Multipliers for nEXO

Author

Gallina, G., primary, Guan, Y., additional, Retiere, F., additional, Cao, G., additional, Bolotnikov, A., additional, Kotov, I., additional, Rescia, S., additional, Soma, A. K., additional, Tsang, T., additional, Darroch, L., additional, Brunner, T., additional, Bolster, J., additional, Cohen, J. R., additional, Franco, T. Pinto, additional, Gillis, W. C., additional, Smalley, H. Peltz, additional, Thibado, S., additional, Pocar, A., additional, Bhat, A., additional, Jamil, A., additional, Moore, D. C., additional, Adhikari, G., additional, Kharusi, S. Al, additional, Angelico, E., additional, Arnquist, I. J., additional, Arsenault, P., additional, Badhrees, I., additional, Bane, J., additional, Belov, V., additional, Bernard, E. P., additional, Bhatta, T., additional, Breur, P. A., additional, Brodsky, J. P., additional, Brown, E., additional, Caden, E., additional, Cao, L., additional, Chambers, C., additional, Chana, B., additional, Charlebois, S. A., additional, Chernyak, D., additional, Chiu, M., additional, Cleveland, B., additional, Collister, R., additional, Cvitan, M., additional, Dalmasson, J., additional, Daniels, T., additional, Deslandes, K., additional, DeVoe, R., additional, di Vacri, M. L., additional, Ding, Y., additional, Dolinski, M. J., additional, Dragone, A., additional, Echevers, J., additional, Eckert, B., additional, Elbeltagi, M., additional, Fabris, L., additional, Fairbank, W., additional, Farine, J., additional, Fu, Y. S., additional, Gallacher, D., additional, Gautam, P., additional, Giacomini, G., additional, Gingras, C., additional, Goeldi, D., additional, Gornea, R., additional, Gratta, G., additional, Hardy, C. A., additional, Hedges, S., additional, Heffner, M., additional, Hein, E., additional, Holt, J., additional, Hoppe, E. W., additional, Hößl, J., additional, House, A., additional, Hunt, W., additional, Iverson, A., additional, Jiang, X. S., additional, Karelin, A., additional, Kaufman, L. J., additional, Krücken, R., additional, Kuchenkov, A., additional, Kumar, K. S., additional, Larson, A., additional, Leach, K. G., additional, Lenardo, B. G., additional, Leonard, D. S., additional, Lessard, G., additional, Li, G., additional, Li, S., additional, Li, Z., additional, Licciardi, C., additional, Lindsay, R., additional, MacLellan, R., additional, Mahtab, M., additional, Majidi, S., additional, Malbrunot, C., additional, Margetak, P., additional, Martel-Dion, P., additional, Martin, L., additional, Masbou, J., additional, Massacret, N., additional, McMichael, K., additional, Mong, B., additional, Murray, K., additional, Nattress, J., additional, Natzke, C. R., additional, Ngwadla, X. E., additional, Ondze, J. C. Nzobadila, additional, Odian, A., additional, Orrell, J. L., additional, Ortega, G. S., additional, Overman, C. T., additional, Parent, S., additional, Perna, A., additional, Piepke, A., additional, Pletskova, N., additional, Pratte, J. F., additional, Radeka, V., additional, Raguzin, E., additional, Ramonnye, G. J., additional, Rao, T., additional, Rasiwala, H., additional, Raymond, K., additional, Rebeiro, B. M., additional, Richardson, G., additional, Ringuette, J., additional, Riot, V., additional, Rossignol, T., additional, Rowson, P. C., additional, Rudolph, L., additional, Saldanha, R., additional, Sangiorgio, S., additional, Shang, X., additional, Spadoni, F., additional, Stekhanov, V., additional, Sun, X. L., additional, Tidball, A., additional, Totev, T., additional, Triambak, S., additional, Tsang, R. H. M., additional, Tyuka, O. A., additional, Vachon, F., additional, Vidal, M., additional, Viel, S., additional, Visser, G., additional, Wagenpfeil, M., additional, Walent, M., additional, Wamba, K., additional, Wang, Q., additional, Wang, W., additional, Wang, Y., additional, Watts, M., additional, Wei, W., additional, Wen, L. J., additional, Wichoski, U., additional, Wilde, S., additional, Worcester, M., additional, Wu, W. H., additional, Wu, X., additional, Xie, L., additional, Yan, W., additional, Yang, H., additional, Yang, L., additional, Zeldovich, O., additional, Zhao, J., additional, and Ziegler, T., additional

Published
2022
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14. Intravenous thrombolysis upon flow restoration improves outcome in endovascular thrombectomy

Author

Weller, Johannes M, Dorn, Franziska, Bormann, A., Braun, M., Eckert, B., Eckert, R. M., Ernemann, U., Ernst, M., Fiehler, J., Gerloff, C., Gröschel, K., Hamann, G. F., Petzold, Gabor C, Henn, K. H., Kellert, L., Kraemer, C., Leischner, H., Liman, J., Ludolph, A., Nikoubashman, O., Nolte, C. H., Petersen, M., Poli, S., Bode, Felix, Reich, A., Röther, J., Schäfer, J. H., Schellinger, P., Siebert, E., Stögbauer, F., Thomalla, G., Tiedt, S., Trumm, C., Uphaus, T., investigators, GSR-ET, Wunderlich, S., Alegiani, A., Berrouschot, J., Boeck-Behrens, T., Bohner, G., and Borggrefe, J.

Subjects
Stroke, Surgery, Neurology (clinical), General Medicine, ddc:610, Thrombolysis, Thrombectomy
Abstract

BackgroundWe hypothesized that ongoing IV thrombolysis (IVT) at flow restoration in patients with acute ischemic stroke (AIS) treated with IVT and endovascular thrombectomy (ET) is associated with improved outcome.MethodsWe included patients with IVT and successful recanalization (modified Thrombolysis in Cerebral Infarction score ≥2b) after ET from an observational multicenter cohort, the German Stroke Registry – Endovascular Treatment trial. Procedural characteristics and functional outcome at discharge and 90 days were compared between patients with and without ongoing IVT at flow restoration. To determine associations with functional outcome, adjusted ORs were calculated using ordinal multivariable logistic regression models adjusted for potential baseline confounder variables.ResultsAmong 1303 patients treated with IVT and ET who achieved successful recanalization, IVT was ongoing in 13.8% (n=180) at flow restoration. Ongoing IVT was associated with better functional outcome at discharge (adjusted OR 1.61; 95% CI 1.13 to 2.30) and at 90 days (adjusted OR 1.52; 95% CI 1.06 to 2.18).ConclusionThese results provide preliminary evidence for a benefit of ongoing IVT at flow restoration in patients with AIS treated with ET.

Published
2022
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21. The Bigger the Better? Center Volume Dependent Effects on Procedural and Functional Outcome in Established Endovascular Stroke Centers.

Author

Hahn, Marianne, Gröschel, Sonja, Tanyildizi, Yasemin, Brockmann, Marc A., Gröschel, Klaus, Uphaus, Timo, Reich, A, Nikoubashman, O, Röther, J, Eckert, B, Braun, M, Hamann, G F, Siebert, E, Nolte, C H, Bohner, G, Eckert, R M, Borggrefe, J, Schellinger, P, Berrouschot, J, and Bormann, A

Subjects
FUNCTIONAL status, LOGISTIC regression analysis, ENDOVASCULAR surgery, ISCHEMIC stroke, HEALTH facilities
Abstract

Background: Mechanical thrombectomy (MT) rates for the treatment of acute ischaemic stroke due to large vessel occlusion are steadily increasing, but are delivered in heterogenic settings. We aim to investigate effects of procedural load in centers with established MT-structures by comparing high- vs. low-volume centers with regard to procedural characteristics and functional outcomes. Methods: Data from 5,379 patients enrolled in the German Stroke Registry Endovascular Treatment (GSR-ET) between June 2015 and December 2019 were compared between three groups: high volume: ≥180 MTs/year, 2,342 patients; medium volume: 135–179 MTs/year, 2,202 patients; low volume: <135 MTs/year, 835 patients. Univariate analysis and multiple linear and logistic regression analyses were performed to identify differences between high- and low-volume centers. Results: We identified high- vs. low-volume centers to be an independent predictor of shorter intra-hospital (admission to groin puncture: 60 vs. 82 min, β = −26.458; p < 0.001) and procedural times (groin puncture to flow restoration: 36 vs. 46.5 min; β = −12.452; p < 0.001) after adjusting for clinically relevant factors. Moreover, high-volume centers predicted a shorter duration of hospital stay (8 vs. 9 days; β = −2.901; p < 0.001) and favorable medical facility at discharge [transfer to neurorehabilitation facility/home vs. hospital/nursing home/in-house fatality, odds ratio (OR) 1.340, p = 0.002]. Differences for functional outcome at 90-day follow-up were observed only on univariate level in the subgroup of primarily to MT center admitted patients (mRS 0–2 38.5 vs. 32.8%, p = 0.028), but did not persist in multivariate analyses. Conclusion: Differences in efficiency measured by procedural times call for analysis and optimization of in-house procedural workflows at regularly used but comparatively low procedural volume MT centers. [ABSTRACT FROM AUTHOR]

Published
2022
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23. Fatigue crack initiation in nickel-based superalloys studied by microstructure-based FE modeling and scanning electron microscopy

Author

Fried M., Krechel C., Affeldt E.E., Eckert B., Kimmig S., Retze U., Höppel H.W., and Göken M.

Subjects
Engineering (General). Civil engineering (General), TA1-2040
Abstract

In this work stage I crack initiation in polycrystalline nickel-based superalloys is investigated by analyzing anisotropic mechanical properties, local stress concentrations and plastic deformation on the microstructural length scale. The grain structure in the gauge section of fatigue specimens was characterized by EBSD. Based on the measured data, a microstructure-based FE model could be established to simulate the strain and stress distribution in the specimens during the first loading cycle of a fatigue test. The results were in fairly good agreement with experimentally measured local strains. Furthermore, the onset of plastic deformation was predicted by identifying shear stress maxima in the microstructure, presumably leading to activation of slip systems. Measurement of plastic deformation and observation of slip traces in the respective regions of the microstructure confirmed the predicted slip activity. The close relation between micro-plasticity, formation of slip traces and stage I crack initiation was demonstrated by SEM surface analyses of fatigued specimens and an in-situ fatigue test in a large chamber SEM.

Published
2014
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27. Cloning, and Molecular Characterization of Polymorphic Iranian Isolate Theileria annulata Surface Protein (Tasp)

Author

Sadr-Shirazi, N., Shayan, P., Eckert, B., Elahe Ebrahimzadeh, and Amininia, N.

Subjects
mRNA, TaSp protein, lcsh:RC109-216, DNA, SMART-cDNA, Iran, Theileria annulata, Cloning, lcsh:Infectious and parasitic diseases
Abstract

Background: Because of the strong immunologic responses of surface protein TaSp in Theileria annu­lata infected host, we tried to characterize this protein in a T. annulata isolate from Iran. Methods: The RNA prepared from T. annulata infected cells was used to produce SMART-DS-cDNA. The Double strand cDNA was then amplified with primers derived from TaSp mRNA se­quences. The PCR product was cloned in pTZ57R/T vector, sequenced and registered under acces­sion no. JQ003240 in GenBank. Results: The sequence analysis showed 90%-94% nucleotide sequence identity and 68%-94% amino acid homology to the corresponding sequences of TaSp gene by T. annulata, T. sp. china I, T. sp. china and T. lestoquardi and three T. annulata reported from Iran respectively. Interestingly, the sequence analysis also showed small nucleotide sequence region near the 5` end in which the presented TaSp protein differed very strongly from the other known TaSp sequences. For the preparation of the recombi­nant protein, the cDNA was cloned in pQE-32 vector, the recombinant protein was pre­pared and assayed by Theileria infected bovine serum. Conclusion: The polymorphism in TaSp gene could be detected in intra- as well as inter species. The different characterized TaSp proteins had a common identic region, which may be helpful for develop­ment of broad band vaccine based on the recombinant proteins. The polymorphism in this gene, make this protein also interesting for the diagnostic purposes.

Published
2012

28. Development of a Reverse Line Blot Hybridization method for Detection of some Streptococcal/Lactococcal Species, the causative agents of Zoonotic Streptococosis/Lactococosis in farmed fish

Author

Soltani, M, Pirali, E, Shayan, P, Eckert, B, Rouholahi, S, and Sadr, Shirazi N

Subjects
S. agalactiae, lcsh:QR1-502, Original Article, S. parauberis, L. garviae, Reverse line blot (RLB), S. iniae, bS. agalactiae, lcsh:Microbiology
Abstract

Background and Objective: Streptococcosis/lactococcosis is the cause of high morbidity and mortality in aquaculture sector and to date a number of species of Streptococcus and Lactococcus genera including S. iniae, S. agalactiae, S. dysagalactiae, S. parauberis, S. feacalis, L. garvieae and L. lactis have been discriminated as the cause of disease in aquatic animals. Despite the use of diagnostic molecular methods for each of these bacterial species, no data is available on a suitable, rapid and simple simultaneous detection tool for these pathogens. This paper describes a simultaneous detection method which is PCR based on a reverse line blot (RLB) for rapid detection and differentiation of four species of genera of Streptococcus and Lactococcus genera consisting of S. iniae, S. agalactiae, S. parauberis and L. garvieae the most important agents of the disease in fish. Materials and Methods: A reverse line blot (RLB) assay was developed for the simultaneously identification of four species of Streptococcus/lactococcusconsisting of S. iniae, S. parauberis, S. agalactiaeand Lactococcusgarvieae. The assay employs one set of primer pair for specific amplification of the 16S rRNA gene. These were designed based on the nucleotide sequences of 16S rRNA gene sharing a homology region with Streptococcus spp. and Lactococcus spp. DNA was extracted from the pure bacterial colonies and amplified. A membrane was prepared with specific oligonucleotide for each bacterial species. PCR products were then hybridized to a membrane. Results and Conclusion: The amplification resulted in PCR product of 241 bp in length. No cross-reactions were observed between any of the tested bacterial species, and mixed DNAs from these four bacterial species were correctly identified. This RLB method is a suitable technique for a simultaneous detection of these species of bacterial fish pathogens that are some of the main causes of streptococcal/lactococcal infections in both freshwater and marine aquatic animals, and so we recommend its use for integrated epidemiological monitoring of streptococcosis/lactococcis in aquaculture industry.

Published
2012

29. A non-interventional, retrospective, cross-sectional study to assess EDSS specific costs and quality of life of patients with multiple sclerosis in Germany

Author

Neidhardt, K, Lang, M, Wasmuth, T, Karampampa, K, Hellmann, M, and Eckert, B

Subjects
ddc: 610, 610 Medical sciences, Medicine, health care economics and organizations
Abstract

Background: Multiple sclerosis (MS) is the most common non-traumatic cause of neurologic disability affecting young adults and is linked to high direct and indirect costs. While cost of illness studies have been carried out in the prior decade, detailed cost data specific to Expanded Disability Status[for full text, please go to the a.m. URL], EbM & Individualisierte Medizin; 12. Jahrestagung des Deutschen Netzwerks Evidenzbasierte Medizin

Published
2011
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31. Endophytic root colonization of gramineous plants by Herbaspirillum frisingense

Author

Rothballer, M, Eckert, B, Schmid, Michael, Fekete, A, Schloter, M, Lehner, A, Pollmann, S, Hartmann, A, University of Zurich, and Hartmann, A

Subjects
Herbaspirillum frisingense, Miscanthus, barley, endophytic colonization, IAA production, AHL production, 2404 Microbiology, 610 Medicine & health, 570 Life sciences, biology, 2402 Applied Microbiology and Biotechnology, AHL, production, 2303 Ecology, 10082 Institute of Food Safety and Hygiene
Abstract

Herbaspirillum frisingense is a diazotrophic betaproteobacterium isolated from C4-energy plants, for example Miscanthus sinensis. To demonstrate endophytic colonization unequivocally, immunological labeling techniques using monospecific polyclonal antibodies against two H. frisingense strains and green fluorescent protein (GFP)-fluorescence tagging were applied. The polyclonal antibodies enabled specific in situ identification and very detailed localization of H. frisingense isolates Mb11 and GSF30(T) within roots of Miscanthusxgiganteus seedlings. Three days after inoculation, cells were found inside root cortex cells and after 7 days they were colonizing the vascular tissue in the central cylinder. GFP-tagged H. frisingense strains could be detected and localized in uncut root material by confocal laser scanning microscopy and were found as endophytes in cortex cells, intercellular spaces and the central cylinder of barley roots. Concerning the production of potential plant effector molecules, H. frisingense strain GSF30(T) tested positive for the production of indole-3-acetic acid, while Mb11 was shown to produce N-acylhomoserine lactones, and both strains were able to utilize 1-aminocyclopropane-1-carboxylate (ACC), providing an indication of the activity of an ACC-deaminase. These results clearly present H. frisingense as a true plant endophyte and, although initial greenhouse experiments did not lead to clear plant growth stimulation, demonstrate the potential of this species for beneficial effects on the growth of crop plants.

Published
2008
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32. Emergency Carotid Artery Stenting in Persistent Hemodynamic Deficit Associated with Severe Carotid Stenosis

Author

Bs, Geisler, Röther J, Kucinski T, Hermann Zeumer, and Eckert B

Subjects
Male, Stroke, Emergency Medical Services, Diffusion Magnetic Resonance Imaging, Interventional, Hemodynamics, Humans, Carotid Stenosis, Stents, cardiovascular diseases, Severity of Illness Index, Aged, Cerebral Angiography
Abstract

Summary: MR imaging in a 73-year-old man presenting with hemispheric stroke revealed a subcortical diffusion-weighted imaging lesion associated with a high-grade stenosis of the proximal internal carotid artery, which suggested hemodynamic infarction. Collateral supply was absent. After failure of conservative therapy, successful unprotected carotid artery stent placement (CAS) was performed followed by a complete neurologic recovery. Emergency CAS should be considered in acute stroke patients with severe hemodynamic impairment if conservative treatment options are not successful.

Published
2005

33. The safety and efficacy of inhaled dry powder mannitol as a bronchial provocation test for airway hyperresponsiveness: a phase 3 comparison study with hypertonic (4.5%) saline

Author

Brannan, JD, Anderson, SD, Perry, CP, Freed-Martens, R, Lassig, AR, Charlton, B, Hurwitz, M, Furler, J, Sunderland, J, Tourniea, W, Nogrady, S, Young, I, Briffa, P, Kippelen, P, Turton, J, McNamara, S, Peters, M, Rogers, P, Plowman, L, Seccombe, L, Cossa, G, Veitch, E, Berend, N, Schoeffel, R, Simmul, R, Keatley, L, Henry, R, Dixon, S, O'Donovan, B, Martin, B, Numa, A, Boynton, A, Morton, J, Belessis, Y, Wheatley, JR, West, S, Bovington, K, Serwach, N, Lee, S, Middleton, P, Mayrhofer, P, Van Asperen, P, Nassar, S, McArthur, M, De Torres, C, McKay, K, Fitzgerald, D, Kennedy, B, Gibson, P, Borgas, T, Smart, J, Bell, N, Sarunac, J, Robertson, C, Smith, J, Sheridan, S, Roberts, M, Stirling, R, Thompson, B, Ellis, M, Borg, B, Jack, S, Hartley, F, Khov, S, Hukins, C, Eckert, B, Ruedinger, L, McLennan, S, Zimmerman, P, McElrea, M, Dent, A, and Rodwell, L

Subjects
Adult, Male, Pulmonary and Respiratory Medicine, Osmotic challenge tesing, Adolescent, medicine.medical_treatment, Sensitivity and Specificity, Bronchial Provocation Tests, 03 medical and health sciences, 0302 clinical medicine, Administration, Inhalation, medicine, Humans, Single-Blind Method, Mannitol, 030212 general & internal medicine, Desiccation, Child, Saline, Asthma, Aged, lcsh:RC705-779, Aged, 80 and over, Saline Solution, Hypertonic, Cross-Over Studies, Inhalation, Dose-Response Relationship, Drug, business.industry, Research, Reproducibility of Results, lcsh:Diseases of the respiratory system, Middle Aged, medicine.disease, 3. Good health, Hypertonic saline, 030228 respiratory system, Anesthesia, Salbutamol, Tonicity, Methacholine, Female, Bronchial Hyperreactivity, Powders, business, medicine.drug, Bronchial provocation test
Abstract

BackgroundInhaled mannitol is a new bronchial provocation test (BPT) developed to improve portability and standardisation of osmotic challenge testing. Osmotic challenge tests have an advantage over the traditional methods of measuring airway hyperresponsiveness using methacholine as they demonstrate higher specificity to identify asthma and thus the need for treatment with inhaled corticosteroids (ICS). The safety and the efficacy of mannitol (M) as a BPT to measure airway hyperresponsiveness were compared to hypertonic (4.5%) saline (HS) in people both with and without signs and symptoms of asthma.MethodsA phase III, multi-centre, open label, operator-blinded, crossover design, randomised trial, with follow-up. Asthmatics and non-asthmatics (6–83 yr) were recruited and 592 subjects completed the study. Mannitol was delivered using a low resistance dry powder inhaler and HS was delivered using an ultrasonic nebuliser. The FEV1was measured 60 seconds after each dose of mannitol (5,10,20,40,80,160,160,160 mg) and after each exposure to HS (0.5,1.0,2.0,4.0,8.0 minutes). A 15% fall in FEV1defined a positive test. Adverse events were monitored and diaries kept for 7 days following the tests.ResultsMean pre-test FEV1 (mean ± SD) was 95.5 ± 14% predicted. 296 were positive to mannitol (M+) and 322 positive to HS (HS+). A post study physician conducted clinical assessment identified 82.3% asthmatic (44% classified mild) and 17.7% non-asthmatic. Of those M+, 70.1% were taking ICS and of those mannitol negative (M-), 81.1 % were taking ICS. The % fall in FEV1 for mannitol in asthmatics was 21.0% ± 5.7 and for the non-asthmatics, 5.5% ± 4.8. The median PD15 M was 148 mg and PD15 HS 6.2 ml. The sensitivity of M to identify HS+ was 80.7% and the specificity 86.7%. The sensitivity of M compared with the clinical assessment was 59.8% and specificity 95.2% and increased to 88.7% and 95.0% respectively when the M- subjects taking ICS were excluded. Cough was common during testing. There were no serious adverse events. The diarised events were similar for mannitol and HS, the most common being headache (17.2%M, 19%HS), pharyngolaryngeal pain (5.1%M, 3%HS), nausea (4.3%M, 3%HS), and cough (2.2%M, 2.4%HS).ConclusionThe efficacy and safety of mannitol was demonstrated in non-asthmatic and clinically diagnosed asthmatic adults and children.

Published
2005

35. Sensitivity and Interrater Agreement of CT and Diffusion-Weighted MR Imaging in Hyperacute Stroke

Author

Saur, D., Kucinski, T., Grzyska, U., Eckert, B., Eggers, C., Niesen, W., Schoder, V., Hermann Zeumer, Weiller, C., and Röther, J.

Subjects
Brain
Abstract

BACKGROUND AND PURPOSE: Previous acute stroke studies found diffusion-weighted (DW) imaging superior to CT for detection of early ischemic signs (EIS). However, these findings were confounded by a large time interval in favor of DW imaging. We compared DW images and CT scans obtained with a short time delay in patients with acute stroke to define the sensitivity and interrater agreement of both imaging techniques. METHODS: CT scans and DW images were obtained within 6 hours of symptom onset in 46 patients with acute stroke. Three neuroradiologists and three neurologists reviewed the images for EIS in five regions of the middle cerebral artery (MCA) territory and estimated the extent of EIS (< or > one-third of the MCA territory). RESULTS: The mean delay between imaging with both modalities was 24.5 minutes (range, 10–41 minutes). Forty-five of 46 patients had an ischemic stroke. EIS were seen on 33 of 45 CT scans (73% sensitivity; 95% confidence interval [CI]: 58–85%) and on 42 of 45 DW images (93% sensitivity; 94% CI: 82–99%). Interrater agreement was moderate (κ = 0.57) for CT and excellent (κ = 0.85) for DW imaging. CT studies had a moderate interrater agreement for estimation of EIS greater than one-third of the MCA territory (κ = 0.40), whereas DW imaging showed good results (κ = 0.68). Sensitivity for detection of greater than one-third of the MCA territory was equally poor (57%, 95% CI: 29–82%) for both CT and DW imaging. CONCLUSION: DW imaging helped identify EIS with higher sensitivity than that of CT. The interrater variability of the one-third rule was high for CT, and thus the clinical applicability of CT is limited. Our results support the application of stroke MR imaging for the treatment of patients with acute stroke.

Published
2003

36. Azospirillum doebereinerae sp. nov., a nitrogen-fixing bacterium associated with the C4-grass Miscanthus

Author

Eckert, B., Weber, O.B., Kirchhof, G., Halbritter, A., Stoffels, M., and Hartmann, A.

Subjects
Azospirillum, Miscanthus, plant-associated bacteria, diazotroph
Abstract

A new group of nitrogen-fixing Azospirillum sp. bacteria was isolated from the roots of the C4-gramineous plant Miscanthus. Polyphasic taxonomy was performed, including auxanography using API galleries, physiological tests and 16S rRNA sequence comparison. The ability of the isolates to fix dinitrogen was evaluated by amplification of the nifD gene, immunodetection of the dinitrogenase reductase and acetylene-reduction assay. On the basis of these results, the nitrogen-fixing isolates represent a new species within the genus Azospirillum. Its closest phylogenetic neighbours, as deduced by 16S rDNA-based analysis, are Azospirillum lipoferum, Azospirillum largimobile and Azospirillum brasilense with 96.6, 96.6 and 95.9% sequence similarity, respectively. Two 16S rRNA-targeting oligonucleotide probes were developed which differentiate the new species from the other Azospirillum species by whole-cell fluorescence hybridization. Strains of the new species are curved rods or S-shaped, 1.0-1.5 microm in width and 2,0-3.0 microm in length, Gram-negative and motile with a single polar flagellum. Optimum growth occurs at 30 degrees C and at pH values between 6.0 and 7.0. No growth takes place at 37 degrees C. They have a respiratory type of metabolism, grow well on arabinose, D-fructose, gluconate, glucose, glycerol, malate, mannitol and sorbitol. They differ from A. largimobile and A. lipoferum by their inability to use N-acetylglucosamine and D-ribose, from A. lipoferum by their ability to grow without biotin supplementation and from A. brasilense by their growth with D-mannitol and D-sorbitol as sole carbon sources. Nitrogen fixation occurs in microaerobic nitrogen-limited conditions. For this species, the name Azospirillum doebereinerae sp. nov. is suggested, with strain GSF71T as the type strain (= DSM 13131T; reference strain Ma4 = DSM 13400). Its G+C content is 70.7 mol%.

Published
2001

37. The Global Lung Initiative 2012 reference values reflect contemporary Australasian spirometry

Author

Hall, Graham, Thompson, B., Stanojevic, S., Abramson, M., Beasley, R., Coates, A., Dent, A., Eckert, B., James, A., Filsell, S., Musk, A., Nolan, G., Dixon, B., O'Dea, C., Savage, J., Stocks, J., Swanney, M., Hall, Graham, Thompson, B., Stanojevic, S., Abramson, M., Beasley, R., Coates, A., Dent, A., Eckert, B., James, A., Filsell, S., Musk, A., Nolan, G., Dixon, B., O'Dea, C., Savage, J., Stocks, J., and Swanney, M.

Abstract

We aimed to ascertain the fit of the European Respiratory Society Global Lung Initiative 2012 reference ranges to contemporary Australasian spirometric data. Z-scores for spirometry from Caucasian subjects aged 4-80 years were calculated. The mean (SD) Z-scores were 0.23 (1.00) for forced expirtory volume in 1 s (FEV 1 ), 0.23 (1.00) for forced vital capacity (FVC), -0.03 (0.87) for FEV 1 /FVC and 0.07 (0.95) for forced expiratory flows between 25% and 75% of FVC. These results support the use of the Global Lung Initiative 2012 reference ranges to interpret spirometry in Caucasian Australasians.

Published
2012

38. The all-age spirometry reference ranges reflect contemporary Australasian spirometry

Author

Thompson, B., Stanojevic, S., Abramson, M., Beasley, R., Coates, A., Dent, A., Eckert, B., James, A., Filsell, S., Musk, A., Nolan, G., Dixon, B., O'Dea, C., Savage, J., Stocks, J., Swanney, M., Hall, Graham, Thompson, B., Stanojevic, S., Abramson, M., Beasley, R., Coates, A., Dent, A., Eckert, B., James, A., Filsell, S., Musk, A., Nolan, G., Dixon, B., O'Dea, C., Savage, J., Stocks, J., Swanney, M., and Hall, Graham

Abstract

Background and objective: Advances in statistical modelling have allowed the creation of smoothly changing spirometry reference ranges that apply across a wide age range and better define the lower limit of normal. The objective of this study was to assess the agreement of the Stanojevic 2009 all-age reference ranges to contemporary lung function data to verify the appropriateness of this reference for clinical use in Australia and New Zealand. Methods: Spirometry data from healthy Caucasians measured between 2000-2009 in Australia and New Zealand were collected. Z-scores were calculated for the standard spirometry outcomes based on the all-age reference ranges. Results: Spirometry from 2066 subjects aged 4-80 years (55% male) from 14 centres were eligible. Statistically, the collated contemporary dataset differed from the all-age reference ranges, but these differences were relatively small and clinically irrelevant representing differences of approximately 3% predicted. Significant differences were also observed between some centres and equipment, potentially indicating varying influence of equipment or subject selection. Conclusions: Spirometry from contemporary Australasian healthy subjects fits the all-age reference ranges well. While the current study supports the use of the all-age reference ranges, the between-centre differences highlight the need for spirometry to be used in conjunction with other clinical findings. The 'all-age' spirometry reference equations significantly advance the definition of the normal range of spirometry. The relevance of these equations for contemporary populations and methods has not been tested. Using collated spirometry data from healthy Australasian subjects we showe d that the all-age spirometry equations provide good estimates for contemporary populations. © 2011 Asian Pacific Society of Respirology.

Published
2011

39. Predicting hemodynamic ischemia by transcranial Doppler monitoring during therapeutic balloon occlusion of the internal carotid artery

Author

Eckert, B., Thie, A., Carvajal, M., Groden, C., and Hermann Zeumer

Subjects
Adult, Carotid Artery Diseases, Male, Adolescent, Ultrasonography, Doppler, Transcranial, Hemodynamics, Middle Aged, Embolization, Therapeutic, Brain Ischemia, Catheterization, Cerebrovascular Circulation, Journal Article, Humans, Female, Child, Carotid Artery, Internal, Aged, Forecasting, Monitoring, Physiologic
Abstract

PURPOSE: Our objective was to evaluate the sensitivity of transcranial Doppler (TCD) sonographic monitoring during permanent balloon occlusion of the internal carotid artery (ICA) in predicting hemodynamic ischemia. METHODS: Thirty-two consecutive patients underwent controlled therapeutic balloon occlusion of the ICA. Selection criteria included assessment of the circle of Willis by compression angiography, clinical tolerance during a 20-minute test occlusion, and TCD monitoring of the ipsilateral middle cerebral artery. The mean blood flow velocity (MBFV) (n = 32) and pulsatility index (PI) (n = 28) were recorded. In 25 patients, MBFV changes upon motor stimulation were recorded before and after ICA occlusion. RESULTS: Twenty-eight (88%) of the patients had no complications. Three patients suffered delayed symptoms 30 minutes to 20 hours after balloon detachment. Two of these patients recovered spontaneously within 1 day, the other improved after extracranial/intracranial (EC/IC) bypass surgery. One patient, who did not tolerate the test occlusion, suffered a hemodynamic stroke despite EC/IC bypass before permanent balloon occlusion. No embolic complications occurred. The mean MBFV reduction was 20% (range, 0% to 55%); the mean PI reduction was 20% (range, 0% to 56%). No complications occurred in patients who had mild MBFV and PI reduction (30% or less, n = 21). All three patients with severe MBFV or PI reduction (> 50%) had neurologic symptoms. Among those with moderate MBFV or PI reduction (30% to 50%, n = 8), symptoms developed in only one patient who had moderate reduction of both MBFV (33%) and PI (38%). Motor vasoreactivity showed wide variation and was markedly reduced in two symptomatic patients. CONCLUSION: TCD monitoring reflects changes in cerebral hemodynamics after therapeutic balloon occlusion of the ICA. MBFV and PI reductions under 30% are highly predictive of clinical tolerance. A reduction of more than 50% may be a critical threshold for the occurrence of symptoms; in such cases, EC/IC bypass should be considered before proceeding with permanent balloon occlusion.

Published
1998

44. The Influence of the Diameter Ratio on the Characteristics Diagram of the Axial Compressor

Author

Eckert, B, Pflueger, F, and Weinig, F

Subjects
Aircraft Propulsion And Power
Abstract

With the further development of axial blowers into highly loaded flow machines, the influence of the diameter ratio upon air output and efficiency gains in significance. Clarification of this matter is important for single-stage axial compressors, and is of still greater importance for multistage ones, and particularly for aircraft power plants. Tests with a single-stage axial blower gave a decrease in the attainable maximum pressure coefficient and optimum efficiency as the diameter ratio increased. The decrease must be ascribed chiefly to the guide surface of the hub and housing between the blades increasing with the diameter ratio.

Published
1948

45. Recent Results on High-Pressure Axial Blowers

Author

Eckert, B

Subjects
Aircraft Propulsion And Power
Abstract

Considerable progress has, in recent times, been attained in the development of the high-pressure axial blower by well-planned research. The efforts are directed toward improving the efficiencies, which are already high for the axial blower, and in particular the delivery pressure heads. For high pressures multistage arrangements are used. Of fundamental importance is the careful design of all structural parts of the blower that are subject to the effects of the flow. In the present report, several recent results and experiences are reported, which are based on results of German engine research.

Published
1947

46. Possibilities of Reducing the Length of Axial Superchargers for Aircraft Motors

Author

Eckert, B

Subjects
Aircraft Propulsion And Power
Abstract

Axial blowers are gaining importance as aircraft engine superchargers. However, the pressure head obtainable per stage is small. Due to the necessary great number of stages, the physical length of the blower becomes too great for an airworthy device. This report discusses several types of construction that permit a reduction in the length of the blower.

Published
1947

47. The resistance coefficient of commercial round wire grids

Author

Eckert, B and Pfluger, F

Abstract

The resistance coefficients of commercial types of round wire grids were examined for the purpose of obtaining the necessary data on supercharger test stands for throttling the inducted air to a pressure corresponding to a desired air density. The measurements of the coefficients ranged up to Reynolds numbers of 1000. In the arrangement of two grids in tandem, which was necessary in order to obtain high resistance coefficients with the solidity, that is, mesh density of grid, was found to be accompanied by a further relationship with the mutual spacing of the individual grids.

Published
1942

48. Experiences with Flow-direction Instruments

Author

Eckert, B

Abstract

The method of recording the direction of flows on the basis of the hydrodynamic zero-point measurement has now reached a certain limit, in spite of the good results achieved. While the available flow-direction devices are accurate enough for many purposes, they are all insufficient for perfectly exact prediction of the flow direction. The next problem will be to achieve a point-by point flow-direction record, whereby the test procedure must be simplified, accelerated, and the degree of accuracy of the test data improved.

Published
1941

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