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Steuer O, Liedke MO, Butterling M, Schwarz D, Schulze J, Li Z, Wagner A, Fischer IA, Hübner R, Zhou S, Helm M, Cuniberti G, Georgiev YM, Prucnal S. Evolution of point defects in pulsed-laser-melted Ge 1-xSn xprobed by positron annihilation lifetime spectroscopy. J Phys Condens Matter 2023; 36:085701. [PMID: 37931296 DOI: 10.1088/1361-648x/ad0a10] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/21/2023] [Accepted: 11/06/2023] [Indexed: 11/08/2023]
Abstract
Direct-band-gap Germanium-Tin alloys (Ge1-xSnx) with high carrier mobilities are promising materials for nano- and optoelectronics. The concentration of open volume defects in the alloy, such as Sn and Ge vacancies, influences the final device performance. In this article, we present an evaluation of the point defects in molecular-beam-epitaxy grown Ge1-xSnxfilms treated by post-growth nanosecond-range pulsed laser melting (PLM). Doppler broadening - variable energy positron annihilation spectroscopy and variable energy positron annihilation lifetime spectroscopy are used to investigate the defect nanostructure in the Ge1-xSnxfilms exposed to increasing laser energy density. The experimental results, supported with ATomic SUPerposition calculations, evidence that after PLM, the average size of the open volume defects increases, which represents a raise in concentration of vacancy agglomerations, but the overall defect density is reduced as a function of the PLM fluence. At the same time, the positron annihilation spectroscopy analysis provides information about dislocations and Ge vacancies decorated by Sn atoms. Moreover, it is shown that the PLM reduces the strain in the layer, while dislocations are responsible for trapping of Sn and formation of small Sn-rich-clusters.
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Affiliation(s)
- O Steuer
- Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstrasse 400, 01328 Dresden, Germany
- Institute of Materials Science, Technische Universität Dresden, Budapester Str. 27, 01069 Dresden, Germany
| | - M O Liedke
- Institute of Radiation Physics, Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstrasse 400, 01328 Dresden, Germany
| | - M Butterling
- Institute of Radiation Physics, Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstrasse 400, 01328 Dresden, Germany
| | - D Schwarz
- University of Stuttgart, Institute of Semiconductor Engineering, 70569 Stuttgart, Germany
| | - J Schulze
- Fraunhofer Institute for Integrated Systems and Device Technology IISB, 91058 Erlangen, Germany
| | - Z Li
- Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstrasse 400, 01328 Dresden, Germany
| | - A Wagner
- Institute of Radiation Physics, Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstrasse 400, 01328 Dresden, Germany
| | - I A Fischer
- Experimental Physics and Functional Materials, Brandenburgische Technische Universität Cottbus-Senftenberg, 03046 Cottbus, Germany
| | - R Hübner
- Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstrasse 400, 01328 Dresden, Germany
| | - S Zhou
- Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstrasse 400, 01328 Dresden, Germany
| | - M Helm
- Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstrasse 400, 01328 Dresden, Germany
- Center for Advancing Electronics Dresden, Technische Universität Dresden, Helmholtzstraße 18, 01062 Dresden, Germany
| | - G Cuniberti
- Institute of Materials Science, Technische Universität Dresden, Budapester Str. 27, 01069 Dresden, Germany
| | - Y M Georgiev
- Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstrasse 400, 01328 Dresden, Germany
- Institute of Electronics, Bulgarian Academy of Sciences, 72, Tsarigradsko Chausse Blvd., 1784 Sofia, Bulgaria
| | - S Prucnal
- Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstrasse 400, 01328 Dresden, Germany
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Waldvogel J, Freyler K, Helm M, Monti E, Stäudle B, Gollhofer A, Narici MV, Ritzmann R, Albracht K. Changes in gravity affect neuromuscular control, biomechanics, and muscle-tendon mechanics in energy storage and dissipation tasks. J Appl Physiol (1985) 2023; 134:190-202. [PMID: 36476161 DOI: 10.1152/japplphysiol.00279.2022] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
This study evaluates neuromechanical control and muscle-tendon interaction during energy storage and dissipation tasks in hypergravity. During parabolic flights, while 17 subjects performed drop jumps (DJs) and drop landings (DLs), electromyography (EMG) of the lower limb muscles was combined with in vivo fascicle dynamics of the gastrocnemius medialis, two-dimensional (2D) kinematics, and kinetics to measure and analyze changes in energy management. Comparisons were made between movement modalities executed in hypergravity (1.8 G) and gravity on ground (1 G). In 1.8 G, ankle dorsiflexion, knee joint flexion, and vertical center of mass (COM) displacement are lower in DJs than in DLs; within each movement modality, joint flexion amplitudes and COM displacement demonstrate higher values in 1.8 G than in 1 G. Concomitantly, negative peak ankle joint power, vertical ground reaction forces, and leg stiffness are similar between both movement modalities (1.8 G). In DJs, EMG activity in 1.8 G is lower during the COM deceleration phase than in 1 G, thus impairing quasi-isometric fascicle behavior. In DLs, EMG activity before and during the COM deceleration phase is higher, and fascicles are stretched less in 1.8 G than in 1 G. Compared with the situation in 1 G, highly task-specific neuromuscular activity is diminished in 1.8 G, resulting in fascicle lengthening in both movement modalities. Specifically, in DJs, a high magnitude of neuromuscular activity is impaired, resulting in altered energy storage. In contrast, in DLs, linear stiffening of the system due to higher neuromuscular activity combined with lower fascicle stretch enhances the buffering function of the tendon, and thus the capacity to safely dissipate energy.NEW & NOTEWORTHY For the first time, the neuromechanics of distinct movement modalities that fundamentally differ in their energy management function have been investigated during overload systematically induced by hypergravity. Parabolic flight provides a unique experimental setting that allows near-natural movement execution without the confounding effects typically associated with load variation. Our findings show that gravity-adjusted muscle activities are inversely affected within jumps and landings. Specifically, in 1.8 G, typical task-specific differences in neuromuscular activity are reduced during the center of mass deceleration phase, resulting in fascicle lengthening, which is associated with energy dissipation.
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Affiliation(s)
- Janice Waldvogel
- Institute of Sport and Sport Science, University of Freiburg, Freiburg, Germany
| | - Kathrin Freyler
- Institute of Sport and Sport Science, University of Freiburg, Freiburg, Germany
| | - Michael Helm
- Institute of Sport and Sport Science, University of Freiburg, Freiburg, Germany
| | - Elena Monti
- Department of Biomedical Sciences, University of Padua, Padua, Italy.,Department of Neurosciences, Imaging and Clinical Science, University of Chieti "G. D'annunzio", Chieti, Italy
| | - Benjamin Stäudle
- Department of Medical Engineering and Technomathematics, Aachen University of Applied Sciences, Aachen, Germany
| | - Albert Gollhofer
- Institute of Sport and Sport Science, University of Freiburg, Freiburg, Germany
| | - Marco V Narici
- Department of Biomedical Sciences, University of Padua, Padua, Italy
| | - Ramona Ritzmann
- Institute of Sport and Sport Science, University of Freiburg, Freiburg, Germany
| | - Kirsten Albracht
- Department of Medical Engineering and Technomathematics, Aachen University of Applied Sciences, Aachen, Germany.,Institute of Movement and Neurosciences, German Sport University Cologne, Cologne, Germany
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Steuer O, Schwarz D, Oehme M, Schulze J, Mączko H, Kudrawiec R, Fischer IA, Heller R, Hübner R, Khan MM, Georgiev YM, Zhou S, Helm M, Prucnal S. Band-gap and strain engineering in GeSn alloys using post-growth pulsed laser melting. J Phys Condens Matter 2022; 35:055302. [PMID: 36395508 DOI: 10.1088/1361-648x/aca3ea] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Accepted: 11/17/2022] [Indexed: 06/16/2023]
Abstract
The pseudomorphic growth of Ge1-xSnxon Ge causes in-plane compressive strain, which degrades the superior properties of the Ge1-xSnxalloys. Therefore, efficient strain engineering is required. In this article, we present strain and band-gap engineering in Ge1-xSnxalloys grown on Ge a virtual substrate using post-growth nanosecond pulsed laser melting (PLM). Micro-Raman and x-ray diffraction (XRD) show that the initial in-plane compressive strain is removed. Moreover, for PLM energy densities higher than 0.5 J cm-2, the Ge0.89Sn0.11layer becomes tensile strained. Simultaneously, as revealed by Rutherford Backscattering spectrometry, cross-sectional transmission electron microscopy investigations and XRD the crystalline quality and Sn-distribution in PLM-treated Ge0.89Sn0.11layers are only slightly affected. Additionally, the change of the band structure after PLM is confirmed by low-temperature photoreflectance measurements. The presented results prove that post-growth ns-range PLM is an effective way for band-gap and strain engineering in highly-mismatched alloys.
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Affiliation(s)
- O Steuer
- Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstrasse 400, 01328 Dresden, Germany
| | - D Schwarz
- University of Stuttgart, Institute of Semiconductor Engineering, 70569 Stuttgart, Germany
| | - M Oehme
- University of Stuttgart, Institute of Semiconductor Engineering, 70569 Stuttgart, Germany
| | - J Schulze
- Fraunhofer Institute for Integrated Systems and Device Technology IISB, 91058 Erlangen, Germany
| | - H Mączko
- Department of Semiconductor Materials Engineering, Faculty of Fundamental Problems of Technology, Wroclaw University of Science and Technology, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław, Poland
| | - R Kudrawiec
- Department of Semiconductor Materials Engineering, Faculty of Fundamental Problems of Technology, Wroclaw University of Science and Technology, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław, Poland
| | - I A Fischer
- Experimental Physics and Functional Materials, Brandenburgische Technische Universität Cottbus-Senftenberg, 03046 Cottbus, Germany
| | - R Heller
- Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstrasse 400, 01328 Dresden, Germany
| | - R Hübner
- Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstrasse 400, 01328 Dresden, Germany
| | - M M Khan
- Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstrasse 400, 01328 Dresden, Germany
| | - Y M Georgiev
- Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstrasse 400, 01328 Dresden, Germany
- Institute of Electronics, Bulgarian Academy of Sciences, 72, Tsarigradsko Chausse Blvd, 1784 Sofia, Bulgaria
| | - S Zhou
- Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstrasse 400, 01328 Dresden, Germany
| | - M Helm
- Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstrasse 400, 01328 Dresden, Germany
| | - S Prucnal
- Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstrasse 400, 01328 Dresden, Germany
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Ilyakov I, Ponomaryov A, Klopf JM, Pashkin A, Deinert JC, de Oliveira TVAG, Evtushenko P, Helm M, Winnerl S, Kovalev S. Field-resolved THz-pump laser-probe measurements with CEP-unstable THz light sources. Opt Express 2022; 30:42141-42154. [PMID: 36366673 DOI: 10.1364/oe.473743] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2022] [Accepted: 10/11/2022] [Indexed: 06/16/2023]
Abstract
Radiation sources with a stable carrier-envelope phase (CEP) are highly demanded tools for field-resolved studies of light-matter interaction, providing access both to the amplitude and phase information of dynamical processes. At the same time, many coherent light sources, including those with outstanding power and spectral characteristics lack CEP stability, and so far could not be used for this type of research. In this work, we present a method enabling linear and non-linear phase-resolved terahertz (THz) -pump laser-probe experiments with CEP-unstable THz sources. THz CEP information for each pulse is extracted using a specially designed electro-optical detection scheme. The method correlates the extracted CEP value for each pulse with the THz-induced response in the parallel pump-probe experiment to obtain an absolute phase-resolved response after proper sorting and averaging. As a proof-of-concept, we demonstrate experimentally field-resolved THz time-domain spectroscopy with sub-cycle temporal resolution using the pulsed radiation of a CEP-unstable infrared free-electron laser (IR-FEL) operating at 13 MHz repetition rate. In spite of the long history of IR-FELs and their unique operational characteristics, no successful realization of CEP-stable operation has been demonstrated yet. Being CEP-unstable, IR-FEL radiation has so far only been used in non-coherent measurements without phase resolution. The technique demonstrated here is robust, operates easily at high-repetition rates and for short THz pulses, and enables common sequential field-resolved time-domain experiments. The implementation of such a technique at IR-FEL user end-stations will facilitate a new class of linear and non-linear experiments for studying coherent light-driven phenomena with increased signal-to-noise ratio.
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Schell S, Cong Z, Sennett M, Gettle S, Longenecker A, Goldberg S, Kirby J, Helm M, Nelson A. 803 Epidermal inflammatory activity is an important driver of hidradenitis suppurativa lesions. J Invest Dermatol 2022. [DOI: 10.1016/j.jid.2022.05.817] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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Raiker R, Salingaros S, Pakhchanian H, Helm M. 205 COVID-19 complications in vitiligo patients: A multicenter study. J Invest Dermatol 2022. [PMCID: PMC9296910 DOI: 10.1016/j.jid.2022.05.212] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Helm M, Loui J, Cotsarelis G, Simon J, Ferrer R. 755 Repurposing of DPP4 inhibition to improve hair follicle activation and regeneration. J Invest Dermatol 2022. [DOI: 10.1016/j.jid.2022.05.768] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Monti E, Waldvogel J, Ritzmann R, Freyler K, Albracht K, Helm M, De Cesare N, Pavan P, Reggiani C, Gollhofer A, Narici MV. Muscle in Variable Gravity: "I Do Not Know Where I Am, But I Know What to Do". Front Physiol 2021; 12:714655. [PMID: 34421657 PMCID: PMC8371909 DOI: 10.3389/fphys.2021.714655] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Accepted: 07/13/2021] [Indexed: 11/24/2022] Open
Abstract
Purpose: Fascicle and sarcomere lengths are important predictors of muscle mechanical performance. However, their regulation during stretch-shortening cycle (SSC) activities in usual and challenging conditions is poorly understood. In this study, we aimed to investigate muscle fascicle and sarcomere behavior during drop jumps (a common SSC activity) in conditions of variable gravity. Methods: Fifteen volunteers performed repeated drop jumps in 1 g, hypo-gravity (0 to 1 g), and hyper-gravity (1 to 2 g) during a parabolic flight. Gastrocnemius medialis (GM) electromyographic activity and fascicle length (Lf) were measured at drop-off, ground contact (GC), minimum ankle joint angle (MAJ), and push-off. GM sarcomere number was estimated by dividing Lf, measured by ultrasound at rest, by published data on GM sarcomere length, and measured in vivo at the same joint angle. Changes in sarcomere length were estimated by dividing GM Lf in each jump phase by sarcomere number calculated individually. The sarcomere force-generating capacity in each jump phase was estimated from the sarcomere length-tension relationship previously reported in the literature. Results: The results showed that, regardless of the gravity level, GM sarcomeres operated in the ascending portion of their length-tension relationship in all the jump phases. Interestingly, although in hypo-gravity and hyper-gravity during the braking phase (GC-MAJ) GM fascicles and sarcomeres experienced a stretch (as opposed to the quasi-isometric behavior in 1 g), at MAJ they reached similar lengths as in 1 g, allowing sarcomeres to develop about the 70% of their maximum force. Conclusion: The observed fascicle behavior during drop jumping seems useful for anchoring the tendon, enabling storage of elastic energy and its release in the subsequent push-off phase for effectively re-bouncing in all gravity levels, suggesting that an innate neuromuscular wisdom enables to perform SSC movements also in challenging conditions.
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Affiliation(s)
- Elena Monti
- Department of Biomedical Science, University of Padova, Padova, Italy
| | - Janice Waldvogel
- Department of Sport and Sport Science, University of Freiburg, Freiburg, Germany
| | - Ramona Ritzmann
- Department of Sport and Sport Science, University of Freiburg, Freiburg, Germany.,Department of Biomechanics, Rennbahnklinik, Muttenz, Switzerland
| | - Kathrin Freyler
- Department of Sport and Sport Science, University of Freiburg, Freiburg, Germany
| | - Kirsten Albracht
- Institute of Movement and Neurosciences, German Sport University Cologne, Cologne, Germany.,Department of Medical Engineering and Technomathematics, Aachen University of Applied Sciences, Aachen, Germany
| | - Michael Helm
- Department of Sport and Sport Science, University of Freiburg, Freiburg, Germany
| | - Niccolò De Cesare
- Department of Industrial Engineering, University of Padova, Padova, Italy
| | - Piero Pavan
- Department of Industrial Engineering, University of Padova, Padova, Italy
| | - Carlo Reggiani
- Department of Biomedical Science, University of Padova, Padova, Italy
| | - Albert Gollhofer
- Department of Sport and Sport Science, University of Freiburg, Freiburg, Germany
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Helm M, Goldann C, Hammer S, Platz Batista da Silva N, Wildgruber M, Deistung A, Gussew A, Wohlgemuth WA, Uller W, Brill R. Vascular malformations of the female and male genitalia: type and distribution patterns revealed by magnetic resonance imaging. Clin Exp Dermatol 2021; 47:43-49. [PMID: 34236712 DOI: 10.1111/ced.14830] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/02/2021] [Indexed: 01/03/2023]
Abstract
BACKGROUND Vascular malformations of the genitalia often go undetected in clinical examination. These vascular malformations can cause a variety of clinical symptoms such as swelling, pain and bleeding. AIM To characterize the distribution patterns of genital vascular malformations using magnetic resonance imaging (MRI) and to correlate these patterns with clinical findings in order to guide diagnostic decisions. METHODS A retrospective analysis of MRIs of the pelvis and legs in 370 patients with vascular malformation was performed to determine the involvement of the internal and external genitalia. RESULTS In 71 patients (19%), genital involvement could be identified by MRI. Of these, 11.3% (8 of 71) presented with internal involvement, 36.6% (26 of 71) with external involvement and 52.1% (37 of 71) with both internal and external involvement. Over half (57.1%) of the 49 patients with visible external genital signs detected during a clinical examination had additional internal genital involvement. CONCLUSIONS Genital involvement is a common finding in patients with vascular malformation of the legs and/or pelvis. Based on our data, we recommend MRI of the legs and pelvic region in patients with externally visible signs of a vascular malformation of the external genitalia in order to exclude additional internal involvement.
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Affiliation(s)
- M Helm
- Department of Radiology and Polyclinic of Radiology, University Hospital Halle (Saale), Halle (Saale), Germany
| | - C Goldann
- Department of Radiology and Polyclinic of Radiology, University Hospital Halle (Saale), Halle (Saale), Germany
| | - S Hammer
- Department of Radiology, University Regensburg, Regensburg, Germany
| | | | - M Wildgruber
- Department of Radiology, University Hospital Ludwig-Maximilians-Universität, Campus Großhadern, Munich, Germany
| | - A Deistung
- Department of Radiology and Polyclinic of Radiology, University Hospital Halle (Saale), Halle (Saale), Germany
| | - A Gussew
- Department of Radiology and Polyclinic of Radiology, University Hospital Halle (Saale), Halle (Saale), Germany
| | - W A Wohlgemuth
- Department of Radiology and Polyclinic of Radiology, University Hospital Halle (Saale), Halle (Saale), Germany
| | - W Uller
- Department of Radiology, University of Freiburg, Freiburg, Germany
| | - R Brill
- Department of Radiology and Polyclinic of Radiology, University Hospital Halle (Saale), Halle (Saale), Germany
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Schultheiss K, Sato N, Matthies P, Körber L, Wagner K, Hula T, Gladii O, Pearson JE, Hoffmann A, Helm M, Fassbender J, Schultheiss H. Time Refraction of Spin Waves. Phys Rev Lett 2021; 126:137201. [PMID: 33861132 DOI: 10.1103/physrevlett.126.137201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Accepted: 03/04/2021] [Indexed: 06/12/2023]
Abstract
We present an experimental study of time refraction of spin waves (SWs) propagating in microscopic waveguides under the influence of time-varying magnetic fields. Using space- and time-resolved Brillouin light scattering microscopy, we demonstrate that the broken translational symmetry along the time coordinate results in a loss of energy conservation for SWs and thus allows for a broadband and controllable shift of the SW frequency. With an integrated design of SW waveguide and microscopic current line for the generation of strong, nanosecond-long, magnetic field pulses, a conversion efficiency up to 39% of the carrier SW frequency is achieved, significantly larger compared to photonic systems. Given the strength of the magnetic field pulses and its strong impact on the SW dispersion relation, the effect of time refraction can be quantified on a length scale comparable to the SW wavelength. Furthermore, we utilize time refraction to excite SW bursts with pulse durations in the nanosecond range and a frequency shift depending on the pulse polarity.
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Affiliation(s)
- K Schultheiss
- Helmholtz-Zentrum Dresden - Rossendorf, Institute of Ion Beam Physics and Materials Research, 01328 Dresden, Germany
| | - N Sato
- Helmholtz-Zentrum Dresden - Rossendorf, Institute of Ion Beam Physics and Materials Research, 01328 Dresden, Germany
| | - P Matthies
- Helmholtz-Zentrum Dresden - Rossendorf, Institute of Ion Beam Physics and Materials Research, 01328 Dresden, Germany
- Fakultät Physik, Technische Universität Dresden, 01062 Dresden, Germany
| | - L Körber
- Helmholtz-Zentrum Dresden - Rossendorf, Institute of Ion Beam Physics and Materials Research, 01328 Dresden, Germany
- Fakultät Physik, Technische Universität Dresden, 01062 Dresden, Germany
| | - K Wagner
- Helmholtz-Zentrum Dresden - Rossendorf, Institute of Ion Beam Physics and Materials Research, 01328 Dresden, Germany
| | - T Hula
- Helmholtz-Zentrum Dresden - Rossendorf, Institute of Ion Beam Physics and Materials Research, 01328 Dresden, Germany
| | - O Gladii
- Helmholtz-Zentrum Dresden - Rossendorf, Institute of Ion Beam Physics and Materials Research, 01328 Dresden, Germany
| | - J E Pearson
- Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - A Hoffmann
- Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - M Helm
- Helmholtz-Zentrum Dresden - Rossendorf, Institute of Ion Beam Physics and Materials Research, 01328 Dresden, Germany
- Fakultät Physik, Technische Universität Dresden, 01062 Dresden, Germany
| | - J Fassbender
- Helmholtz-Zentrum Dresden - Rossendorf, Institute of Ion Beam Physics and Materials Research, 01328 Dresden, Germany
- Fakultät Physik, Technische Universität Dresden, 01062 Dresden, Germany
| | - H Schultheiss
- Helmholtz-Zentrum Dresden - Rossendorf, Institute of Ion Beam Physics and Materials Research, 01328 Dresden, Germany
- Fakultät Physik, Technische Universität Dresden, 01062 Dresden, Germany
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11
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Waldvogel J, Ritzmann R, Freyler K, Helm M, Monti E, Albracht K, Stäudle B, Gollhofer A, Narici M. The Anticipation of Gravity in Human Ballistic Movement. Front Physiol 2021; 12:614060. [PMID: 33815134 PMCID: PMC8010298 DOI: 10.3389/fphys.2021.614060] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2020] [Accepted: 02/01/2021] [Indexed: 11/23/2022] Open
Abstract
Stretch-shortening type actions are characterized by lengthening of the pre-activated muscle-tendon unit (MTU) in the eccentric phase immediately followed by muscle shortening. Under 1 g, pre-activity before and muscle activity after ground contact, scale muscle stiffness, which is crucial for the recoil properties of the MTU in the subsequent push-off. This study aimed to examine the neuro-mechanical coupling of the stretch-shortening cycle in response to gravity levels ranging from 0.1 to 2 g. During parabolic flights, 17 subjects performed drop jumps while electromyography (EMG) of the lower limb muscles was combined with ultrasound images of the gastrocnemius medialis, 2D kinematics and kinetics to depict changes in energy management and performance. Neuro-mechanical coupling in 1 g was characterized by high magnitudes of pre-activity and eccentric muscle activity allowing an isometric muscle behavior during ground contact. EMG during pre-activity and the concentric phase systematically increased from 0.1 to 1 g. Below 1 g the EMG in the eccentric phase was diminished, leading to muscle lengthening and reduced MTU stretches. Kinetic energy at take-off and performance were decreased compared to 1 g. Above 1 g, reduced EMG in the eccentric phase was accompanied by large MTU and muscle stretch, increased joint flexion amplitudes, energy loss and reduced performance. The energy outcome function established by linear mixed model reveals that the central nervous system regulates the extensor muscles phase- and load-specifically. In conclusion, neuro-mechanical coupling appears to be optimized in 1 g. Below 1 g, the energy outcome is compromised by reduced muscle stiffness. Above 1 g, loading progressively induces muscle lengthening, thus facilitating energy dissipation.
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Affiliation(s)
- Janice Waldvogel
- Department of Sport and Science, University of Freiburg, Freiburg, Germany
| | - Ramona Ritzmann
- Department of Sport and Science, University of Freiburg, Freiburg, Germany.,Department of Biomechanics, Rennbahnklinik, Muttenz, Switzerland
| | - Kathrin Freyler
- Department of Sport and Science, University of Freiburg, Freiburg, Germany
| | - Michael Helm
- Department of Sport and Science, University of Freiburg, Freiburg, Germany
| | - Elena Monti
- Neuromuscular Physiology Laboratory, Department of Biomedical Sciences, University of Padua, Padua, Italy
| | - Kirsten Albracht
- Faculty of Medical Engineering and Technomathematics, Aachen University of Applied Sciences, Aachen, Germany.,Institute of Biomechanics and Orthopedics, German Sport University Cologne, Cologne, Germany.,Institute of Movement and Neurosciences, German Sport University Cologne, Cologne, Germany
| | - Benjamin Stäudle
- Faculty of Medical Engineering and Technomathematics, Aachen University of Applied Sciences, Aachen, Germany
| | - Albert Gollhofer
- Department of Sport and Science, University of Freiburg, Freiburg, Germany
| | - Marco Narici
- Neuromuscular Physiology Laboratory, Department of Biomedical Sciences, University of Padua, Padua, Italy.,Myology Centre 'CIR-Myo', Neuromuscular Physiology Laboratory, Department of Biomedical Sciences, University of Padua, Padua, Italy
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12
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Helm M, Freyler K, Waldvogel J, Gollhofer A, Ritzmann R. Response to: gender differences on neuromuscular strategy during drop jump: a comment on Helm et al. (2019) by Di Giminiani et al. Eur J Appl Physiol 2020; 120:2557-2558. [PMID: 32772248 PMCID: PMC7560930 DOI: 10.1007/s00421-020-04460-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Accepted: 08/04/2020] [Indexed: 11/28/2022]
Affiliation(s)
- M Helm
- Institute of Sport and Sport Science, University of Freiburg, Schwarzwaldstraße 175, 79117, Freiburg, Germany
| | - K Freyler
- Institute of Sport and Sport Science, University of Freiburg, Schwarzwaldstraße 175, 79117, Freiburg, Germany.
| | - J Waldvogel
- Institute of Sport and Sport Science, University of Freiburg, Schwarzwaldstraße 175, 79117, Freiburg, Germany
| | - A Gollhofer
- Institute of Sport and Sport Science, University of Freiburg, Schwarzwaldstraße 175, 79117, Freiburg, Germany
| | - R Ritzmann
- Institute of Sport and Sport Science, University of Freiburg, Schwarzwaldstraße 175, 79117, Freiburg, Germany
- Rennbahnklinik, Muttenz, Switzerland
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13
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Helm M, Riedl S, Jérôme V, Freitag R. Ex‐vivo Expansion und Differenzierung primärer humaner B‐Lymphozyten. CHEM-ING-TECH 2020. [DOI: 10.1002/cite.202055171] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- M. Helm
- Universität Bayreuth Lehrstuhl für Bioprozesstechnik Universitätsstr. 30 95447 Bayreuth Deutschland
| | - S. A. B. Riedl
- Universität Bayreuth Lehrstuhl für Bioprozesstechnik Universitätsstr. 30 95447 Bayreuth Deutschland
| | - V. Jérôme
- Universität Bayreuth Lehrstuhl für Bioprozesstechnik Universitätsstr. 30 95447 Bayreuth Deutschland
| | - R. Freitag
- Universität Bayreuth Lehrstuhl für Bioprozesstechnik Universitätsstr. 30 95447 Bayreuth Deutschland
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14
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Hossfeld B, Lechner R, Josse F, Bernhard M, Walcher F, Helm M, Kulla M. [Prehospital application of tourniquets for life-threatening extremity hemorrhage : Systematic review of literature]. Unfallchirurg 2019; 121:516-529. [PMID: 29797031 DOI: 10.1007/s00113-018-0510-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
INTRODUCTION The effectiveness of a tourniquet in the case of life-threatening hemorrhages of the extremities is well recognized and led to the recommendations on "Tourniquet" of the German Society of Anaesthesiology and Intensive Care (DGAI) in 2016. The aim of this systematic review was to re-evaluate the current medical literature in relation to the published DGAI recommendations. MATERIAL AND METHODS Based on the analysis of all studies published from January 2015 until January 2018 in the PubMed databases, the publicized recommendations for action on "Tourniquet" of the DGAI were critically re-evaluated. For this purpose, 17 questions on 6 subjects were formulated in advance. The systematic review followed the PRISMA recommendations and is registered in PROSPERO (International prospective register of systematic reviews, Reg.-ID: CRD42018091528). RESULTS Of the 284 studies identified with the keywords tourniquet and trauma in the period from January 2015 to January 2018 in PubMed, 50 original papers discussing the prehospital application of tourniquet for life-threatening hemorrhage of the extremities were included. The overall level of evidence is low. No article addressed any of the formulated questions with a prospective randomized interventional study. Scientific deductions could be found only in an indirect way in a descriptive manner. CONCLUSION The 50 original articles included in this qualitative, systematic review revealed that the recommendations "Tourniquet" of the DGAI published in 2016 are mostly still up to date despite an inhomogeneous study situation. A deviation occurred in the conversion of a tourniquet but due to the short prehospital treatment time in the civilian setting this is of little importance; however, in the future a strict distinction should be made between tourniquets which were placed for tactical reasons and those placed as a medical necessity.
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Affiliation(s)
- B Hossfeld
- Klinik für Anästhesiologie und Intensivmedizin, Sektion Notfallmedizin, Bundeswehrkrankenhaus Ulm, Oberer Eselsberg 40, 89081, Ulm, Deutschland.,Arbeitsgruppe "Taktische Medizin", Arbeitskreises Notfallmedizin, Deutsche Gesellschaft für Anästhesiologie und Intensivmedizin, Nürnberg, Deutschland.,Tactical Rescue and Emergency Medicine Association (TREMA e. V.), Tübingen, Deutschland
| | - R Lechner
- Klinik für Anästhesiologie und Intensivmedizin, Sektion Notfallmedizin, Bundeswehrkrankenhaus Ulm, Oberer Eselsberg 40, 89081, Ulm, Deutschland.,Tactical Rescue and Emergency Medicine Association (TREMA e. V.), Tübingen, Deutschland
| | - F Josse
- Klinik für Anästhesiologie und Intensivmedizin, Sektion Notfallmedizin, Bundeswehrkrankenhaus Ulm, Oberer Eselsberg 40, 89081, Ulm, Deutschland.,Arbeitsgruppe "Taktische Medizin", Arbeitskreises Notfallmedizin, Deutsche Gesellschaft für Anästhesiologie und Intensivmedizin, Nürnberg, Deutschland.,Tactical Rescue and Emergency Medicine Association (TREMA e. V.), Tübingen, Deutschland
| | - M Bernhard
- Zentrale Notaufnahme, Universitätsklinikum Düsseldorf, Düsseldorf, Deutschland.,Arbeitsgruppe "Trauma- und Schockraummanagement", Arbeitskreis Notfallmedizin, Deutsche Gesellschaft für Anästhesiologie und Intensivmedizin, Nürnberg, Deutschland
| | - F Walcher
- Universitätsklinik für Unfallchirurgie, Universitätsklinikum Magdeburg, Magdeburg, Deutschland.,Sektion Notfall‑, Intensivmedizin und Schwerverletztenversorgung (NIS), Deutsche Gesellschaft für Unfallchirurgie (DGU), Berlin, Deutschland
| | - M Helm
- Klinik für Anästhesiologie und Intensivmedizin, Sektion Notfallmedizin, Bundeswehrkrankenhaus Ulm, Oberer Eselsberg 40, 89081, Ulm, Deutschland.,Arbeitsgruppe "Taktische Medizin", Arbeitskreises Notfallmedizin, Deutsche Gesellschaft für Anästhesiologie und Intensivmedizin, Nürnberg, Deutschland
| | - M Kulla
- Klinik für Anästhesiologie und Intensivmedizin, Sektion Notfallmedizin, Bundeswehrkrankenhaus Ulm, Oberer Eselsberg 40, 89081, Ulm, Deutschland. .,Arbeitsgruppe "Taktische Medizin", Arbeitskreises Notfallmedizin, Deutsche Gesellschaft für Anästhesiologie und Intensivmedizin, Nürnberg, Deutschland. .,Sektion Notfall‑, Intensivmedizin und Schwerverletztenversorgung (NIS), Deutsche Gesellschaft für Unfallchirurgie (DGU), Berlin, Deutschland.
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15
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Helm M, Freyler K, Waldvogel J, Lauber B, Gollhofer A, Ritzmann R. Anticipation of drop height affects neuromuscular control and muscle-tendon mechanics. Scand J Med Sci Sports 2019; 30:46-63. [PMID: 31487062 DOI: 10.1111/sms.13550] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2019] [Revised: 08/25/2019] [Accepted: 08/28/2019] [Indexed: 11/26/2022]
Abstract
This study examined the effect of drop height on neuromechanical control of the plantarflexors in drop jumps (DJs) before and during ground contact (GC). The effect of anticipation on muscle mechanical configurations was investigated in 22 subjects in three conditions (20, 30, and 40 cm): (i) known, (ii) unknown, or (iii) cheat falling heights (announced 40 cm, but actual drop height was 20 cm). Electromyographic (EMG) activity of the m. gastrocnemius medialis (GM) and other shank muscles was recorded and analyzed before GC and during GC separately for the short-, medium-, and long-latency responses (SLR, MLR, and LLR). Changes in GM fascicle length (LM ) were determined via B-mode ultrasound, and muscle-tendon unit length (LMTU ) was estimated. Peak force (P < .001), rate of force development (RFD) (P = .001) and GM EMG activity prior to (P = .003) and during GC (P = .007) was reduced in the unknown compared with the known conditions (P < .05). The amount of shortening in LMTU during GC in unknown and cheat was less compared with the known conditions (P = .005; P = .049). Changes in LMTU lengthening negatively correlated with changes in GM activity around SLR and MLR (P = .006; P = .02) in known and unknown conditions. Taken together, it seems that the central nervous system applies a protective strategy in the unknown condition by reducing muscle activity to result in a lower muscular stiffness and increased tendinous lengthening prior to and during GC. This might be a mechanism to absorb greater elastic energy in the tendon and reduce the magnitude and rate of muscle lengthening and subsequent stretch-induced muscle damage.
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Affiliation(s)
- Michael Helm
- Institute of Sport and Sport Science, University of Freiburg, Freiburg, Germany
| | - Kathrin Freyler
- Institute of Sport and Sport Science, University of Freiburg, Freiburg, Germany
| | - Janice Waldvogel
- Institute of Sport and Sport Science, University of Freiburg, Freiburg, Germany
| | - Benedikt Lauber
- Institute of Sport and Sport Science, University of Freiburg, Freiburg, Germany.,Department of Neurosciences and Movement Sciences, University of Fribourg, Fribourg, Switzerland
| | - Albert Gollhofer
- Institute of Sport and Sport Science, University of Freiburg, Freiburg, Germany
| | - Ramona Ritzmann
- Institute of Sport and Sport Science, University of Freiburg, Freiburg, Germany.,Praxisklinik Rennbahn AG, Muttenz, Switzerland
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16
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Häske D, Böttiger BW, Bouillon B, Fischer M, Gaier G, Gliwitzky B, Helm M, Hilbert-Carius P, Hossfeld B, Schempf B, Wafaisade A, Bernhard M. Analgesie bei Traumapatienten in der Notfallmedizin. Notf Rett Med 2019. [DOI: 10.1007/s10049-019-00629-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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17
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Helm M, Freyler K, Waldvogel J, Gollhofer A, Ritzmann R. The relationship between leg stiffness, forces and neural control of the leg musculature during the stretch-shortening cycle is dependent on the anticipation of drop height. Eur J Appl Physiol 2019; 119:1981-1999. [PMID: 31367910 DOI: 10.1007/s00421-019-04186-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2019] [Accepted: 07/08/2019] [Indexed: 11/25/2022]
Abstract
PURPOSE This study aimed at investigating how prior knowledge of drop heights affects proactive and reactive motor control in drop jumps (DJ). METHODS In 22 subjects, the effect of knowledge of three different drop heights (20, 30, 40 cm) during DJs was evaluated in seven conditions: three different drop heights were either known, unknown or cheated (announced 40 cm, but actual drop height was 20 cm). Peak ground reaction force (Fmax) to body weight (BW) ratio (Fmax/BW) and electromyographic (EMG) activities of three shank and five thigh muscles were assessed 150 ms before and during ground contact (GC). Ankle, knee and hip joint kinematics were recorded in the sagittal plane. RESULTS Leg stiffness, proactive and reactive EMG activity of the leg muscles diminished in unknown and cheat conditions for all drop heights (7-33% and 2-26%, respectively). Antagonistic co-activation increased in unknown (3-37%). At touchdown, increased flexion in knee (~ 5.3° ± 1.9°) and hip extension (~ 2° ± 0.6°) were observed in unknown, followed by an increased angular excursion in hip (~ 2.3° ± 0.2°) and knee joints (~ 5.6° ± 0.2°) during GC (p < 0.05). Correlations between changes in activation intensities, joint kinematics, leg stiffness and Fmax/BW (p < 0.05) indicate that anticipation changes the neuromechanical coupling of DJs. No dropouts were recorded. CONCLUSION These findings underline that anticipation influences timing and adjustment of motor responses. It is argued that proactive and reactive modulations associated with diminished activation intensities in leg extensors are functionally relevant in explaining changes in leg stiffness and subsequent decline in performance.
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Affiliation(s)
- Michael Helm
- Institute of Sport and Sport Science, University of Freiburg, Schwarzwaldstr. 175, 79117, Freiburg, Germany.
| | - Kathrin Freyler
- Institute of Sport and Sport Science, University of Freiburg, Schwarzwaldstr. 175, 79117, Freiburg, Germany
| | - Janice Waldvogel
- Institute of Sport and Sport Science, University of Freiburg, Schwarzwaldstr. 175, 79117, Freiburg, Germany
| | - Albert Gollhofer
- Institute of Sport and Sport Science, University of Freiburg, Schwarzwaldstr. 175, 79117, Freiburg, Germany
| | - Ramona Ritzmann
- Institute of Sport and Sport Science, University of Freiburg, Schwarzwaldstr. 175, 79117, Freiburg, Germany
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18
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Holubarsch J, Helm M, Ringhof S, Gollhofer A, Freyler K, Ritzmann R. Stumbling reactions in hypo and hyper gravity - muscle synergies are robust across different perturbations of human stance during parabolic flights. Sci Rep 2019; 9:10490. [PMID: 31324854 PMCID: PMC6642199 DOI: 10.1038/s41598-019-47091-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2019] [Accepted: 07/10/2019] [Indexed: 11/21/2022] Open
Abstract
The control of bipedal stance and the capacity to regain postural equilibrium after its deterioration in variable gravities are crucial prerequisites for manned space missions. With an emphasize on natural orthograde posture, computational techniques synthesize muscle activation patterns of high complexity to a simple synergy organization. We used nonnegative matrix factorization to identify muscle synergies during postural recovery responses in human and to examine the functional significance of such synergies for hyper-gravity (1.75 g) and hypo-gravity (0.25 g). Electromyographic data were recorded from leg, trunk and arm muscles of five human exposed to five modes of anterior and posterior support surface translations during parabolic flights including transitional g-levels of 0.25, 1 and 1.75 g. Results showed that in 1 g four synergies accounted for 99% of the automatic postural response across all muscles and perturbation directions. Each synergy in 1 g was correlated to the corresponding one in 0.25 and 1.75 g. This study therefore emphasizes the similarity of the synergy organization of postural recovery responses in Earth, hypo- and hyper-gravity conditions, indicating that the muscle synergies and segmental strategies acquired under terrestrial habits are robust and persistent across variable and acute changes in gravity levels.
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Affiliation(s)
- Janek Holubarsch
- Department of Sport and Sport Science, University of Freiburg, Freiburg, Germany
| | - Michael Helm
- Department of Sport and Sport Science, University of Freiburg, Freiburg, Germany
| | - Steffen Ringhof
- Department of Sport and Sport Science, University of Freiburg, Freiburg, Germany.
| | - Albert Gollhofer
- Department of Sport and Sport Science, University of Freiburg, Freiburg, Germany
| | - Kathrin Freyler
- Department of Sport and Sport Science, University of Freiburg, Freiburg, Germany
| | - Ramona Ritzmann
- Department of Sport and Sport Science, University of Freiburg, Freiburg, Germany.,Praxisklinik Rennbahn AG, Muttenz, Switzerland
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19
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Ritzmann R, Freyler K, Helm M, Holubarsch J, Gollhofer A. Stumbling Reactions in Partial Gravity - Neuromechanics of Compensatory Postural Responses and Inter-Limb Coordination During Perturbation of Human Stance. Front Physiol 2019; 10:576. [PMID: 31164834 PMCID: PMC6536696 DOI: 10.3389/fphys.2019.00576] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Accepted: 04/24/2019] [Indexed: 02/05/2023] Open
Abstract
Spontaneous changes in gravity play a significant role in interplanetary space missions. To preserve the astronauts’ capability to execute mission-critical tasks and reduce the risk of injury in transit and on planetary surfaces, a comprehensive understanding of the neuromuscular control of postural responses after balance deterioration in hypo- or hyper-gravity conditions is essential. Therefore, this study aimed to evaluate the effect of acute gravitational variation on postural adjustments in response to perturbations. Gravitational changes were induced using parabolic flight. Postural set was manipulated by randomly providing unilateral left, bilateral or split perturbations which require balance corrections to restore postural stability. In six subjects, postural reactions were recorded after anterior and posterior surface perturbations for progressively increased gravitational conditions spanning from 0.25 to 1.75 g. Ankle and knee joint kinematics and electromyograms (EMG) of eight leg muscles were recorded prior (PRE) and after perturbation onset. Muscle activation onset latencies and amplitudes in the short-, medium-, and long-latency responses (SLR, MLR, LLR) were assessed. Results demonstrate an increased muscle activity (p < 0.05) and co-contraction in the lower extremities (p < 0.05) prior to perturbation in hypo- and hyper-gravity. After perturbation, reduced muscle onset latencies (p < 0.05) and increased muscle activations in the MLR and LLR (p < 0.05), concomitant with an increased co-contraction in the SLR, were manifested with a progressive rise in gravity. Ankle and knee joint deflections remained unaffected, whereas angular velocities increased (p < 0.05) with increasing gravitation. Effects were more pronounced in bi- compared to unilateral or split perturbations (p < 0.05). Neuro-mechanical adaptations to gravity were more distinct and muscle onset latencies were shorter in the displaced compared to the non-displaced leg. In conclusion, the timing and magnitude of postural reflexes involved in stabilization of bipedal stance are gravity-dependent. The approximately linear relationship between gravity and impulse-directed EMG amplitudes or muscle onset latencies after perturbation indicates that the central nervous system correctly predicts the level of gravity. Moreover, it accurately governs contractions in the antigravity musculature to counterbalance the gravitational pull and to regain upright posture after its disturbance. Importantly, unilateral perturbations evoked fast reflex responses in the synergistic muscles of the non-displaced contralateral leg suggesting a synchronized inter-limb coordination mediated by spinal circuitries.
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Affiliation(s)
- Ramona Ritzmann
- Institute of Sport and Sport Science, University of Freiburg, Freiburg, Germany.,Praxisklinik Rennbahn AG, Muttenz, Switzerland
| | - Kathrin Freyler
- Institute of Sport and Sport Science, University of Freiburg, Freiburg, Germany
| | - Michael Helm
- Institute of Sport and Sport Science, University of Freiburg, Freiburg, Germany
| | - Janek Holubarsch
- Institute of Sport and Sport Science, University of Freiburg, Freiburg, Germany
| | - Albert Gollhofer
- Institute of Sport and Sport Science, University of Freiburg, Freiburg, Germany
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20
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Helm M, Bazewicz C, Butt M, Shumaker K, Foulke G. 1027 Psychosocial toll of dermatomyositis: Does malignancy risk play a role? J Invest Dermatol 2019. [DOI: 10.1016/j.jid.2019.03.1103] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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21
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Helm M, Ritzmann R, Gollhofer A, Freyler K. Anticipation modulates neuromechanics of drop jumps in known or unknown ground stiffness. PLoS One 2019; 14:e0211276. [PMID: 30682132 PMCID: PMC6347232 DOI: 10.1371/journal.pone.0211276] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2018] [Accepted: 01/10/2019] [Indexed: 12/18/2022] Open
Abstract
With an emphasis on ballistic movements, an accurately anticipated neural control is an essential prerequisite to deliver a motor response coincidentally with the event of ground contact. This study investigated how previous knowledge of the ground condition affects proactive and reactive motor control in drop jumps (DJ). Thereby, human anticipatory capacity of muscle activation was investigated regarding neuromuscular activation, joint kinematics and peak forces associated with DJ performance. In 18 subjects, the effect of knowledge of two different surface conditions during DJs was evaluated. Peak force, ground-contact-time (GCT), rate of force development (RFD) and jump height were assessed. Electromyographic (EMG) activities of the m. soleus (SOL) and gastrocnemius medialis (GM) were assessed for 150ms before (PRE) and during ground contact (GC) for the short-, medium-, and long-latency responses. Ankle and knee joint kinematics were recorded in the sagittal plane.In the unknown conditions peak force, RFD and jump height declined, GCT was prolonged, proactive EMG activity (PRE) in SOL and GM was diminished (P<0.05). During GC, a decline in EMG activity in the unknown condition was manifested for SOL and GM for the SLR, MLR and LLR (P<0.05). Ankle and knee joint deflections during GC were increased in the unknown vs. known condition (P<0.05). Peak force, RFD and jump height were positively correlated to GM-EMG in PRE, SLR, MLR and LLR (P<0.05). Results revealed that proactive and reactive modulations in muscle activity prior and during GC are interrelated to the force-time characteristics and height of the jumps. The unknown condition revealed a comparable neuromuscular activity during pre-activation for both conditions, followed by an inhibition in the subsequent phase after touch down. These findings underline that anticipation is a determining factor influencing timing and adjustment of motor responses to accomplish ballistic movements regarding precision and performance.
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Affiliation(s)
- Michael Helm
- Department of Sport and Sport Science, University of Freiburg, Freiburg i.Br., Germany
- * E-mail:
| | - Ramona Ritzmann
- Department of Sport and Sport Science, University of Freiburg, Freiburg i.Br., Germany
| | - Albert Gollhofer
- Department of Sport and Sport Science, University of Freiburg, Freiburg i.Br., Germany
| | - Kathrin Freyler
- Department of Sport and Sport Science, University of Freiburg, Freiburg i.Br., Germany
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22
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Höwing T, Dann M, Müller B, Helm M, Scholz S, Schneitz K, Hammes UZ, Gietl C. The role of KDEL-tailed cysteine endopeptidases of Arabidopsis (AtCEP2 and AtCEP1) in root development. PLoS One 2018; 13:e0209407. [PMID: 30576358 PMCID: PMC6303060 DOI: 10.1371/journal.pone.0209407] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2018] [Accepted: 12/05/2018] [Indexed: 12/17/2022] Open
Abstract
Plants encode a unique group of papain-type cysteine endopeptidases (CysEP) characterized by a C-terminal KDEL endoplasmic reticulum retention signal (KDEL-CysEP) and an unusually broad substrate specificity. The three Arabidopsis KDEL-CysEPs (AtCEP1, AtCEP2, and AtCEP3) are differentially expressed in vegetative and generative tissues undergoing programmed cell death (PCD). While KDEL-CysEPs have been shown to be implicated in the collapse of tissues during PCD, roles of these peptidases in processes other than PCD are unknown. Using mCherry-AtCEP2 and EGFP-AtCEP1 reporter proteins in wild type versus atcep2 or atcep1 mutant plants, we explored the participation of AtCEP in young root development. Loss of AtCEP2, but not AtCEP1 resulted in shorter primary roots due to a decrease in cell length in the lateral root (LR) cap, and impairs extension of primary root epidermis cells such as trichoblasts in the elongation zone. AtCEP2 was localized to root cap corpses adherent to epidermal cells in the rapid elongation zone. AtCEP1 and AtCEP2 are expressed in root epidermis cells that are separated for LR emergence. Loss of AtCEP1 or AtCEP2 caused delayed emergence of LR primordia. KDEL-CysEPs might be involved in developmental tissue remodeling by supporting cell wall elongation and cell separation.
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Affiliation(s)
- Timo Höwing
- Lehrstuhl für Botanik, Center of Life and Food Sciences Weihenstephan, Technische Universitaet Muenchen, Freising, Germany
| | - Marcel Dann
- Lehrstuhl für Botanik, Center of Life and Food Sciences Weihenstephan, Technische Universitaet Muenchen, Freising, Germany
| | - Benedikt Müller
- Cell Biology and Plant Biochemistry, Biochemie-Zentrum Regensburg, University of Regensburg, Regensburg, Germany
| | - Michael Helm
- Lehrstuhl für Botanik, Center of Life and Food Sciences Weihenstephan, Technische Universitaet Muenchen, Freising, Germany
| | - Sebastian Scholz
- Plant Developmental Biology, Center of Life and Food Sciences Weihenstephan, Technische Universitaet Muenchen, Freising, Germany
| | - Kay Schneitz
- Plant Developmental Biology, Center of Life and Food Sciences Weihenstephan, Technische Universitaet Muenchen, Freising, Germany
| | - Ulrich Z. Hammes
- Cell Biology and Plant Biochemistry, Biochemie-Zentrum Regensburg, University of Regensburg, Regensburg, Germany
| | - Christine Gietl
- Lehrstuhl für Botanik, Center of Life and Food Sciences Weihenstephan, Technische Universitaet Muenchen, Freising, Germany
- * E-mail:
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23
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Lechner R, Helm M, Müller M, Wille T, Riesner HJ, Friemert B. In-vitro study of species-specific coagulation differences in animals and humans using rotational thromboelastometry (ROTEM). J ROY ARMY MED CORPS 2018; 165:356-359. [DOI: 10.1136/jramc-2018-001092] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Accepted: 10/11/2018] [Indexed: 11/03/2022]
Abstract
Animal tests are conducted in all fields of trauma research, but transferability of these data to humans is limited. For example, it is still unclear which animal species is most similar to humans in terms of physiology of blood coagulation. To improve transferability and raise awareness of the existing differences, we compared human coagulation to coagulation of different animals. Rotational thromboelastometry was used to analyse the blood of pigs, sheep, rabbits and dogs. Animal data were compared with human coagulation based on the number of significant differences of the test parameters and on a descriptive comparison of the extent of relative deviation of the single values. All animal species showed significant differences in coagulation properties when compared with humans. Coagulation parameters of dogs and sheep were on average most similar to humans. However, there is no animal which is most similar to humans concerning all aspects of coagulation. Differences in coagulation between humans and animals are significant. This must be taken into account when transferring animal test data to humans.
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Bernhard M, Wurmb T, Helm M. Taktische (Notfall‑)Medizin: Die Welt hat sich verändert – wir haben dies begriffen und werden unser Management anpassen! Notf Rett Med 2018. [DOI: 10.1007/s10049-018-0551-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Berencén Y, Prucnal S, Möller W, Hübner R, Rebohle L, Schönherr T, Khan MB, Wang M, Glaser M, Georgiev YM, Erbe A, Lugstein A, Helm M, Zhou S. Formation of n- and p-type regions in individual Si/SiO 2 core/shell nanowires by ion beam doping. Nanotechnology 2018; 29:474001. [PMID: 30192233 DOI: 10.1088/1361-6528/aadfb6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
A method for cross-sectional doping of individual Si/SiO2 core/shell nanowires (NWs) is presented. P and B atoms are laterally implanted at different depths in the Si core. The healing of the implantation-related damage together with the electrical activation of the dopants takes place via solid phase epitaxy driven by millisecond-range flash lamp annealing. Electrical measurements through a bevel formed along the NW enabled us to demonstrate the concurrent formation of n- and p-type regions in individual Si/SiO2 core/shell NWs. These results might pave the way for ion beam doping of nanostructured semiconductors produced by using either top-down or bottom-up approaches.
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Affiliation(s)
- Y Berencén
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Ion Beam Physics and Materials Research, Bautzner Landstraße 400, D-01328 Dresden, Germany
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Bernhard M, Wurmb T, Helm M. Taktische (Notfall‑)Medizin: Die Welt hat sich verändert, wir müssen dies begreifen und unser Management anpassen. Notf Rett Med 2018. [DOI: 10.1007/s10049-018-0517-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Castañeda-Uribe OA, Criollo CA, Winnerl S, Helm M, Avila A. Comparative study of equivalent circuit models for photoconductive antennas. Opt Express 2018; 26:29017-29031. [PMID: 30470070 DOI: 10.1364/oe.26.029017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2018] [Accepted: 09/18/2018] [Indexed: 06/09/2023]
Abstract
Comparison of equivalent circuit models (ECM) for photoconductive antennas (PCA) represents a challenge due to the multiphysics phenomena involved during PCA operation and the absence of a standardized validation methodology. In this work, currently reported ECMs are compared using a unique set of simulation parameters and validation indicators (THz waveform, optical power saturation, and ECM voltages consistency). The ECM simulations are contrasted with measured THz pulses of an H-shaped 20μm gap PCA at different optical powers (20mW to 220mW). In addition, an alternative two-element ECM that accounts for both space-charge and radiation screening effects is presented and validated using the proposed methodology. The model shows an accurately reproduced THz pulse using a reduced number of circuital elements, which represents an advantage for PCA modeling.
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Wurmb T, Schorscher N, Justice P, Dietz S, Schua R, Jarausch T, Kinstle U, Greiner J, Möldner G, Müller J, Kraus M, Simon S, Wagenhäuser U, Hemm J, Roewer N, Helm M. Structured analysis, evaluation and report of the emergency response to a terrorist attack in Wuerzburg, Germany using a new template of standardised quality indicators. Scand J Trauma Resusc Emerg Med 2018; 26:87. [PMID: 30340516 PMCID: PMC6194622 DOI: 10.1186/s13049-018-0555-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2018] [Accepted: 10/02/2018] [Indexed: 11/20/2022] Open
Abstract
Background Until now there has been a reported lack of systematic reports and scientific evaluations of rescue missions during terror attacks. This however is urgently required in order to improve the performance of emergency medical services and to be able to compare different missions with each other. Aim of the presented work was to report the systematic evaluation and the lessons learned from the response to a terror attack that happened in Wuerzburg, Germany in 2016. Methods A team of 14 experts developed a template of quality indicators and operational characteristics, which allow for the description, assessment and comparison of civil emergency rescue missions during mass killing incidents. The entire systematic evaluation process consisted of three main steps. The first step was the systematic data collection according to the quality indicators and operational characteristics. Second was the systematic stratification and assessment of the data. The last step was the prioritisation of the identified weaknesses and the definition of the lessons learned. Results Five important “lessons learned” have been defined. First of all, a comprehensive concept for rescue missions during terror attacks is essential. Furthermore, the establishment of a defined high priority communication infrastructure between the different dispatch centres (“red phone”) is vital. The goal is to secure the continuity of information between a few well-defined individuals. Thirdly, the organization of the incident scene needs to be commonly decided and communicated between police, medical services and fire services during the mission. A successful mission tactic requires continuous flux of reports to the on-site command post. Therefore, a predefined and common communication infrastructure for all operational forces is a crucial point. Finally, all strategies need to be extensively trained before the real life scenario hits. Conclusion According to a systematic evaluation, we defined the lessons learned from a terror attack in 2016. Further systematic reports and academic work surrounding life threatening rescue missions and mass killing incidents are needed in order to ultimately improve such mission outcomes. In the future, a close international collaboration might help to find the best database to report and evaluate major incidents but also mass killing events.
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Affiliation(s)
- T Wurmb
- Subsection Emergency and Disaster Relief Medicine, Department of Anaesthesia and Critical Care, University Hospital of Wuerzburg, Oberdürrbacherstrasse 6, 97080, Würzburg, Germany.
| | - N Schorscher
- Department of Anaesthesia and Critical Care, University Hospital of Wuerzburg, Wuerzburg, Germany
| | - P Justice
- Emergency Medical Services and firebrigade alerting for the counties of Kitzingen, Main-Spessart and the city of Wuerzburg, Wuerzburg, Germany
| | - S Dietz
- Emergency Medical Service of the Bavarian Red Cross, Würzburg, Germany
| | - R Schua
- Medical Department, Government of Lower Franconia, Wuerzburg, Germany
| | - T Jarausch
- Emergency Medical Service of the Maltese Cross, Wuerzburg, Germany
| | - U Kinstle
- The Johanniter Rescue Emergency Services, Wuerzburg, Germany
| | - J Greiner
- Emergency Medical Service of the Bavarian Red Cross, Würzburg, Germany
| | - G Möldner
- Fire and Rescue Integrated Control Centre Wuerzburg, Wuerzburg, Germany
| | - J Müller
- Fire and Rescue Integrated Control Centre Wuerzburg, Wuerzburg, Germany
| | - M Kraus
- Medical Head of the Emergency Medical Services of Lower Fraconia, Wuerzburg, Germany
| | - S Simon
- Emergency Medical Service of the Maltese Cross, Wuerzburg, Germany
| | - U Wagenhäuser
- Head of emergency pastoral care in the diocese of Würzburg, Wuerzburg, Germany
| | - J Hemm
- Department of danger prevention and police operation by the police department of Lower Franconia (Chief Police Officer i.R.), Würzburg, Wuerzburg, Germany
| | - N Roewer
- Department of Anaesthesia and Critical Care, University Hospital of Wuerzburg, Wuerzburg, Germany
| | - M Helm
- Department of Anaesthesiology and Intensive Care Medicine, Section Emergency Medicine, Federal Armed Forces Medical Hospital, Ulm, Germany
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Helm M, Kulla M, Stöhr A, Josse F, Hossfeld B. Erratum zu: Prähospitales Management traumatischer Blutungen. Notf Rett Med 2018. [DOI: 10.1007/s10049-018-0486-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Abstract
In 2003 an article on the future of prehospital emergency medicine in Germany was published in the journal Der Anaesthesist. Emergency medicine in Germany, which at that time was almost exclusively defined as prehospital emergency rescue, has evolved and now in-hospital domains have increasingly moved into the focus. At that time, the primary goal was to connect prehospital management with a smooth transition to hospital admission and further care in the hospital and to further optimize the rescue chain from the actual emergency through to causative treatment. Now after 15 years, the authors have critically assessed the development postulated in 2003 and reevaluated it. Which aspects could be developed further and become firmly established, what is still open and which questions in preclinical and clinical emergency treatment of the population will occupy us in the coming 15 years? With a critical eye to the past, the present contribution aims to capture the essential and new topics and open questions and provide a fresh perspective for the future of emergency medicine. Regulation at the state level or even lower levels of government often stand in contrast to more sweeping and economically effective approaches at the federal level. Prehospital emergency medicine in Germany is on the whole well-positioned with respect to facilities and personnel; however, as far as the economic situation and the utilization of available systems are concerned, there is still substantial room for improvement.
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Affiliation(s)
- A Gries
- Zentrale Notaufnahme, Universitätsklinikum Leipzig, Leipzig, Deutschland.
| | - M Bernhard
- Zentrale Notaufnahme, Universitätsklinikum Leipzig, Leipzig, Deutschland
| | - M Helm
- Abt X, Anästhesie und Intensivmedizin, Bundeswehrkrankenhaus Ulm, Ulm, Deutschland
| | - J Brokmann
- Zentrale Notaufnahme, Uniklinik RWTH Aachen, Aachen, Deutschland
| | - J-T Gräsner
- Institut für Rettungs- und Notfallmedizin, Universitätsklinikum Schleswig-Holstein, Kiel, Deutschland
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Zhang ZT, Xu C, Dmytriieva D, Molatta S, Wosnitza J, Wang YT, Helm M, Zhou S, Kühne H. Monovacancy paramagnetism in neutron-irradiated graphite probed by 13C NMR. J Phys Condens Matter 2017; 29:465801. [PMID: 29053468 DOI: 10.1088/1361-648x/aa8d47] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
We report on the magnetic properties of monovacancy defects in neutron-irradiated graphite, probed by 13C nuclear magnetic resonance spectroscopy. The bulk paramagnetism of the defect moments is revealed by the temperature dependence of the NMR frequency shift and spectral linewidth, both of which follow a Curie behavior, in agreement with measurements of the macroscopic magnetization. Compared to pristine graphite, the fluctuating hyperfine fields generated by the defect moments lead to an enhancement of the 13C nuclear spin-lattice relaxation rate [Formula: see text] by about two orders of magnitude. With an applied magnetic field of 7.1 T, the temperature dependence of [Formula: see text] below about 10 K can well be described by a thermally activated form, [Formula: see text], yielding a singular Zeeman energy of ([Formula: see text]) meV, in excellent agreement with the sole presence of polarized, non-interacting defect moments.
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Affiliation(s)
- Z T Zhang
- Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, D-01314 Dresden, Germany. Hochfeld-Magnetlabor Dresden (HLD-EMFL), Helmholtz-Zentrum Dresden-Rossendorf, D-01314 Dresden, Germany
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Radakovic D, Reboredo J, Helm M, Weigel T, Schürlein S, Kupczyk E, Leyh RG, Walles H, Hansmann J. A multilayered electrospun graft as vascular access for hemodialysis. PLoS One 2017; 12:e0185916. [PMID: 29023551 PMCID: PMC5638257 DOI: 10.1371/journal.pone.0185916] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2017] [Accepted: 09/21/2017] [Indexed: 01/08/2023] Open
Abstract
Despite medical achievements, the number of patients with end-stage kidney disease keeps steadily raising, thereby entailing a high number of surgical and interventional procedures to establish and maintain arteriovenous vascular access for hemodialysis. Due to vascular disease, aneurysms or infection, the preferred access-an autogenous arteriovenous fistula-is not always available and appropriate. Moreover, when replacing small diameter blood vessels, synthetic vascular grafts possess well-known disadvantages. A continuous multilayered gradient electrospinning was used to produce vascular grafts made of collagen type I nanofibers on luminal and adventitial graft side, and poly-ɛ-caprolactone as medial layer. Therefore, a custom-made electrospinner with robust environmental control was developed. The morphology of electrospun grafts was characterized by scanning electron microscopy and measurement of mechanical properties. Human microvascular endothelial cells were cultured in the graft under static culture conditions and compared to cultures obtained from dynamic continuous flow bioreactors. Immunofluorescent analysis showed that endothelial cells form a continuous luminal layer and functional characteristics were confirmed by uptake of acetylated low-density-lipoprotein. Incorporation of vancomycin and gentamicin to the medial graft layer allowed antimicrobial inhibition without exhibiting an adverse impact on cell viability. Most striking a physiological hemocompatibility was achieved for the multilayered grafts.
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Affiliation(s)
- D. Radakovic
- Department of Thoracic and Cardiovascular Surgery, University Hospital Wuerzburg, Josef-Schneider-Straße 2, Wuerzburg, Germany
| | - J. Reboredo
- Department of Tissue Engineering and Regenerative Medicine, University Hospital Wuerzburg, Roentgenring 11, Wuerzburg, Germany
| | - M. Helm
- Department of Tissue Engineering and Regenerative Medicine, University Hospital Wuerzburg, Roentgenring 11, Wuerzburg, Germany
- Fraunhofer Institute for Silicate Research, Neunerplatz 2, Wuerzburg, Germany
| | - T. Weigel
- Department of Tissue Engineering and Regenerative Medicine, University Hospital Wuerzburg, Roentgenring 11, Wuerzburg, Germany
| | - S. Schürlein
- Department of Tissue Engineering and Regenerative Medicine, University Hospital Wuerzburg, Roentgenring 11, Wuerzburg, Germany
| | - E. Kupczyk
- Department of Tissue Engineering and Regenerative Medicine, University Hospital Wuerzburg, Roentgenring 11, Wuerzburg, Germany
| | - R. G. Leyh
- Department of Thoracic and Cardiovascular Surgery, University Hospital Wuerzburg, Josef-Schneider-Straße 2, Wuerzburg, Germany
| | - H. Walles
- Department of Tissue Engineering and Regenerative Medicine, University Hospital Wuerzburg, Roentgenring 11, Wuerzburg, Germany
- Fraunhofer Institute for Silicate Research, Neunerplatz 2, Wuerzburg, Germany
| | - J. Hansmann
- Department of Tissue Engineering and Regenerative Medicine, University Hospital Wuerzburg, Roentgenring 11, Wuerzburg, Germany
- Fraunhofer Institute for Silicate Research, Neunerplatz 2, Wuerzburg, Germany
- * E-mail:
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Piętka B, Bobrovska N, Stephan D, Teich M, Król M, Winnerl S, Pashkin A, Mirek R, Lekenta K, Morier-Genoud F, Schneider H, Deveaud B, Helm M, Matuszewski M, Szczytko J. Doubly Dressed Bosons: Exciton Polaritons in a Strong Terahertz Field. Phys Rev Lett 2017; 119:077403. [PMID: 28949662 DOI: 10.1103/physrevlett.119.077403] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2017] [Indexed: 06/07/2023]
Abstract
We demonstrate the existence of a novel quasiparticle, an exciton in a semiconductor doubly dressed with two photons of different wavelengths: a near infrared cavity photon and terahertz (THz) photon, with the THz coupling strength approaching the ultrastrong coupling regime. This quasiparticle is composed of three different bosons, being a mixture of a matter-light quasiparticle. Our observations are confirmed by a detailed theoretical analysis, treating quantum mechanically all three bosonic fields. The doubly dressed quasiparticles retain the bosonic nature of their constituents, but their internal quantum structure strongly depends on the intensity of the applied terahertz field.
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Affiliation(s)
- B Piętka
- Institute of Experimental Physics, Faculty of Physics, University of Warsaw, ul. Pasteura 5, 02-093 Warsaw, Poland
| | - N Bobrovska
- The Institute of Physics, Polish Academy of Sciences, al. Lotników 32/46, 02-668 Warsaw, Poland
| | - D Stephan
- Institute of Experimental Physics, Faculty of Physics, University of Warsaw, ul. Pasteura 5, 02-093 Warsaw, Poland
- Institute of Ion Beam Physics and Materials Research, HZDR, P.O. Box 510119, 01314 Dresden, Germany
| | - M Teich
- Institute of Ion Beam Physics and Materials Research, HZDR, P.O. Box 510119, 01314 Dresden, Germany
| | - M Król
- Institute of Experimental Physics, Faculty of Physics, University of Warsaw, ul. Pasteura 5, 02-093 Warsaw, Poland
| | - S Winnerl
- Institute of Ion Beam Physics and Materials Research, HZDR, P.O. Box 510119, 01314 Dresden, Germany
| | - A Pashkin
- Institute of Ion Beam Physics and Materials Research, HZDR, P.O. Box 510119, 01314 Dresden, Germany
| | - R Mirek
- Institute of Experimental Physics, Faculty of Physics, University of Warsaw, ul. Pasteura 5, 02-093 Warsaw, Poland
| | - K Lekenta
- Institute of Experimental Physics, Faculty of Physics, University of Warsaw, ul. Pasteura 5, 02-093 Warsaw, Poland
| | - F Morier-Genoud
- Institute of Physics, Ecole Polytechnique Fédérale de Lausanne (EPFL), Station 3, 1015 Lausanne, Switzerland
| | - H Schneider
- Institute of Ion Beam Physics and Materials Research, HZDR, P.O. Box 510119, 01314 Dresden, Germany
| | - B Deveaud
- Institute of Physics, Ecole Polytechnique Fédérale de Lausanne (EPFL), Station 3, 1015 Lausanne, Switzerland
- Ecole Polytechnique, F-91128 Palaiseau, France
| | - M Helm
- Institute of Ion Beam Physics and Materials Research, HZDR, P.O. Box 510119, 01314 Dresden, Germany
| | - M Matuszewski
- The Institute of Physics, Polish Academy of Sciences, al. Lotników 32/46, 02-668 Warsaw, Poland
| | - J Szczytko
- Institute of Experimental Physics, Faculty of Physics, University of Warsaw, ul. Pasteura 5, 02-093 Warsaw, Poland
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Hossfeld B, Jongebloed A, Lampl L, Helm M. [Out-of-hospital airway management in trauma patients : Experiences with the C-MAC® video laryngoscope]. Unfallchirurg 2017; 119:501-7. [PMID: 25135707 DOI: 10.1007/s00113-014-2642-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
BACKGROUND Securing the airway is the top priority in trauma resuscitation. The most important factor for successful endotracheal intubation (ETI) is good visualization of the vocal cords. The aim of this study was to summarize the practical experiences with the C-MAC® video laryngoscope as initial device in out-of-hospital airway management of trauma patients. METHODS The C-MAC® video laryngoscope uses standard Macintosh shaped laryngoscope blades. At the Helicopter Emergency Medical Service (HEMS) Christoph 22 it is used as the initial device for every out-of-hospital ETI. All prehospital data on ETI involving trauma patients were documented for a period of 17 months. RESULTS A total of 116 out-of-hospital ETIs were enrolled in this study (overall success rate 100 %). In 88.8 % the first attempt was successful, whereas in 10.3 % a second and in 0.9 % a third ETI attempt was necessary. No patient required alternative airway devices or surgical airway interventions. The results of a subgroup with an immobilized cervical spine (n = 17) did not show any increased difficulties. CONCLUSION The use of the C-MAC® video laryngoscope by experienced anesthesiologists in an out-of-hospital setting seems to be a safe method even in patients with an immobilized cervical spine. Adverse laryngoscopy results (C/L III and IV) were reduced compared to other studies.
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Affiliation(s)
- B Hossfeld
- Klinik für Anästhesiologie und Intensivmedizin - Sektion Notfallmedizin, Bundeswehrkrankenhaus Ulm, Oberer Eselsberg 40, 89070, Ulm, Deutschland.
| | - A Jongebloed
- Klinik für Anästhesiologie und Intensivmedizin - Sektion Notfallmedizin, Bundeswehrkrankenhaus Ulm, Oberer Eselsberg 40, 89070, Ulm, Deutschland
| | - L Lampl
- Klinik für Anästhesiologie und Intensivmedizin - Sektion Notfallmedizin, Bundeswehrkrankenhaus Ulm, Oberer Eselsberg 40, 89070, Ulm, Deutschland
| | - M Helm
- Klinik für Anästhesiologie und Intensivmedizin - Sektion Notfallmedizin, Bundeswehrkrankenhaus Ulm, Oberer Eselsberg 40, 89070, Ulm, Deutschland
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Kulla M, Maier J, Bieler D, Lefering R, Hentsch S, Lampl L, Helm M. [Civilian blast injuries: an underestimated problem? : Results of a retrospective analysis of the TraumaRegister DGU®]. Unfallchirurg 2017; 119:843-53. [PMID: 26286180 DOI: 10.1007/s00113-015-0046-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Blast injuries are a rare cause of potentially life-threatening injuries in Germany. During the past 30 years such injuries were seldom the cause of mass casualties, therefore, knowledge and skills in dealing with this type of injury are not very extensive. MATERIAL AND METHODS A retrospective identification of all patients in the TraumaRegister DGU® of the German Trauma Society (TR-DGU) who sustained blast injuries between January 1993 and November 2012 was carried out. The study involved a descriptive characterization of the collective as well as three additional collectives. The arithmetic mean, standard deviation and 95 % confidence interval of the arithmetic mean for different demographic parameters and figures for prehospital and in-hospital settings were calculated. A computation of prognostic scores, such as the Revised Injury Severity Classification (RISC) and the updated version RISC II (TR-DGU-Project-ID 2012-035) was performed. RESULTS A total of 137 patients with blast injuries could be identified in the dataset of the TR-DGU. Of the patients 90 % were male and 43 % were transported by the helicopter emergency service (HEMS) to the various trauma centres. The severely injured collective with a mean injury severity scale (ISS) of 18.0 (ISS ≥ 16 = 52 %) had stable vital signs. In none of the cases was it necessary to perform on-site emergency surgery but a very high proportion of patients (59 %) had to be surgically treated before admittance to the intensive care unit (ICU). Of the patients 27 % had severe soft tissue injuries with an Abbreviated Injury Scale (AIS) ≥ 3 and 90 % of these injuries were burns. The 24 h in-hospital fatality was very low (3 %) but the stay in the ICU tended to be longer than for other types of injury (mean 5.5 ventilation days and 10.7 days in the intensive care unit). Organ failure occurred in 36 % of the cases, multiorgan failure in 29 % and septic events in 14 %. Of the patients 16 % were transferred to another hospital during the first 48 h. The RISC and the updated RISC II tended to underestimate the severity of injuries and mortality (10.2 % vs. 6.8 % and 10.7 % vs. 7.5 %, respectively) and the trauma associated severe hemorrhage (TASH) score underestimated the probability for transfusion of more than 10 units of packed red blood cells (5.0 % vs. 12.5 %). CONCLUSION This article generates several hypotheses, which should be confirmed with additional investigations. Until then it has to be concluded that patients who suffer from accidental blast injuries in the civilian setting (excluding military operations and terrorist attacks) show a combination of classical severe trauma with blunt and penetrating injuries and additionally a high proportion of severe burns (combined thermomechanical injury). They stay longer in the ICU than other trauma patients and suffer more complications, such as sepsis and multiorgan failure. Established scores, such as RISC, RISC II and TASH tend to underestimate the severity of the underlying trauma.
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Affiliation(s)
- M Kulla
- Klinik für Anästhesiologie und Intensivmedizin, Bundeswehrkrankhaus Ulm, Akademisches Krankenhaus der Universität Ulm, Oberer Eselsberg 40, 89081, Ulm, Deutschland.
| | - J Maier
- Klinik für Anästhesiologie und Intensivmedizin, Bundeswehrkrankhaus Ulm, Akademisches Krankenhaus der Universität Ulm, Oberer Eselsberg 40, 89081, Ulm, Deutschland
| | - D Bieler
- Klinik für Unfallchirurgie und Orthopädie, Wiederherstellungs-, Hand- und Plastische Chirurgie, Verbrennungsmedizin, Bundeswehrzentralkrankenhaus Koblenz, Koblenz, Deutschland
| | - R Lefering
- Institut für Forschung in der Operativen Medizin, Universität Witten-Herdecke, Witten, Deutschland
| | - S Hentsch
- Klinik für Unfallchirurgie und Orthopädie, Wiederherstellungs-, Hand- und Plastische Chirurgie, Verbrennungsmedizin, Bundeswehrzentralkrankenhaus Koblenz, Koblenz, Deutschland
| | - L Lampl
- Klinik für Anästhesiologie und Intensivmedizin, Bundeswehrkrankhaus Ulm, Akademisches Krankenhaus der Universität Ulm, Oberer Eselsberg 40, 89081, Ulm, Deutschland
| | - M Helm
- Klinik für Anästhesiologie und Intensivmedizin, Bundeswehrkrankhaus Ulm, Akademisches Krankenhaus der Universität Ulm, Oberer Eselsberg 40, 89081, Ulm, Deutschland
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Henke T, Freund F, Wieprich D, Helm M, Bergold M, Byhahn C. Der Terroranschlag von Berlin – Die Vorgeschichte, der Einsatz und die Konsequenzen aus präklinischer Sicht. Notarzt 2017. [DOI: 10.1055/s-0043-105439] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
- T. Henke
- Zentrale Notaufnahme, Medizinischer Campus Universität Oldenburg, Evangelisches Krankenhaus Oldenburg
| | - F. Freund
- Johanniter-Unfall-Hilfe e. V., Ortsverband Oldenburg
| | - D. Wieprich
- Johanniter-Unfall-Hilfe e. V., Regionalverband Berlin
| | - M. Helm
- Klinik für Anästhesiologie, Intensivmedizin, Notfallmedizin und Schmerztherapie, Bundeswehrkrankenhaus Ulm
| | - M. Bergold
- Klinik für Anästhesiologie, Intensivmedizin und Schmerztherapie, Medizinischer Campus Universität Oldenburg, Evangelisches Krankenhaus Oldenburg
| | - C. Byhahn
- Klinik für Anästhesiologie, Intensivmedizin und Schmerztherapie, Medizinischer Campus Universität Oldenburg, Evangelisches Krankenhaus Oldenburg
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Wurmb T, Justice P, Dietz S, Schua R, Jarausch T, Kinstle U, Greiner J, Möldner G, Müller J, Kraus M, Simon S, Wagenhäuser U, Roewer N, Helm M. [Quality indicators for rescue operations in terrorist attacks or other threats : A pilot study after the Würzburg terrorist attack of July 2016]. Anaesthesist 2017; 66:404-411. [PMID: 28386683 DOI: 10.1007/s00101-017-0298-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2017] [Revised: 03/08/2017] [Accepted: 03/14/2017] [Indexed: 10/19/2022]
Abstract
BACKGROUND Terrorist attacks have become reality in Germany. The aim of this work was, after the Würzburg terrorist attack, to define quality indicators and application characteristics for rescue missions in life-threatening situations. The results can be used to record data from future missions using this template in order to make them comparable with each other. METHODS After approval of the local ethic committee, the first step was to designate a group of experts in order to define the template in a consensus process. The next step was to perform the consensus process by defining the template. An independent expert for emergency medicine and disaster management reviewed and approved the results afterwards. RESULTS The expert group defined 13 categories and 158 parameters that will further serve the systematic evaluation of the rescue mission of the Würzburg terror attack. Preliminary results of this evaluation process are given in this paper; the full evaluation has not yet been completed. DISCUSSION In this study we first describe quality indicators and parameters suitable for the German rescue system in order to evaluate rescue operations for violence caused mass casualties. There is similar international documentation, but it does not specifically focus on life-threatening operations and are not adapted to the German context. CONCLUSION There is an important need to systematically evaluate rescue missions after mass killing incidents. In this study we report a template of parameters and quality indicators in order to systematically evaluate mass violence events. The presented template is the result of an expert consensus process and may serve as a basis for further development and research.
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Affiliation(s)
- T Wurmb
- Sektion Notfall- und Katastrophenmedizin, Klinik und Poliklinik für Anästhesiologie des Universitätsklinikums Würzburg, Oberdürrbacherstraße 6, 97080, Würzburg, Deutschland.
| | - P Justice
- Geschäftsführer des Zweckverbands für Rettungsdienst und Feuerwehralarmierung, Landratsamt Würzburg, Würzburg, Deutschland
| | - S Dietz
- Organisatorischer Leiter, Bayerisches Rotes Kreuz, Kreisverband Würzburg, Würzburg, Deutschland
| | - R Schua
- Leitender Medizinaldirektor, Regierung von Unterfranken, Würzburg, Deutschland
| | - T Jarausch
- Leitender Notarzt für Würzburg Stadt, Würzburg, Deutschland
| | - U Kinstle
- Mitglied Regionalvorstand, Johanniter-Unfall-Hilfe, Würzburg, Deutschland
| | - J Greiner
- Sachgebietsleiter Einsatzdienste, Kreisverband Würzburg, Bayerisches Rotes Kreuz, Würzburg, Deutschland
| | - G Möldner
- Leiter der Integrierten Leitstelle Würzburg, Amt für Zivil- und Brandschutz der Stadt Würzburg, Würzburg, Deutschland
| | - J Müller
- Integrierte Leitstelle Würzburg, Amt für Zivil- und Brandschutz der Stadt Würzburg, Würzburg, Deutschland
| | - M Kraus
- Ärztlicher Leiter Rettungsdienst (Bezirksbeauftragter), Würzburg, Deutschland
| | - S Simon
- Malteser Hilfsdienst, Würzburg, Deutschland
| | - U Wagenhäuser
- Leiter der Notfallseelsorge, Diözese Würzburg, Würzburg, Deutschland
| | - N Roewer
- Klinik und Poliklinik für Anästhesiologie des Universitätsklinikums Würzburg, Würzburg, Deutschland
| | - M Helm
- Sektion Notfallmedizin - Klinik für Anästhesiologie & Intensivmedizin, Bundeswehrkrankenhaus Ulm, Ulm, Deutschland
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Hilbert-Carius P, Wurmb T, Lier H, Fischer M, Helm M, Lott C, Böttiger BW, Bernhard M. [Care for severely injured persons : Update of the 2016 S3 guideline for the treatment of polytrauma and the severely injured]. Anaesthesist 2017; 66:195-206. [PMID: 28138737 DOI: 10.1007/s00101-017-0265-9] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
In 2011 the first interdisciplinary S3 guideline for the management of patients with serious injuries/trauma was published. After intensive revision and in consensus with 20 different medical societies, the updated version of the guideline was published online in September 2016. It is divided into three sections: prehospital care, emergency room management and the first operative phase. Many recommendations and explanations were updated, mostly in the prehospital care and emergency room management sections. These two sections are of special interest for anesthesiologists in field emergency physician roles or as team members or team leaders in the emergency room. The present work summarizes the changes to the current guideline and gives a brief overview of this very important work.
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Affiliation(s)
- P Hilbert-Carius
- Klinik für Anästhesiologie, Intensiv- und Notfallmedizin, Schmerztherapie, BG Klinikum Bergmannstrost Halle gGmbH, Merseburger Str. 165, 06112, Halle (Saale), Deutschland.
| | - T Wurmb
- Sektion Notfall- und Katastrophenmedizin, Klinik und Poliklinik für Anästhesiologie, Universitätsklinikum Würzburg, Würzburg, Deutschland
| | - H Lier
- Klinik für Anästhesiologie und Operative Intensivmedizin, Universitätsklinikum Köln, Köln, Deutschland
| | - M Fischer
- Klinik für Anästhesiologie und Intensivmedizin, Klinik am Eichert, ALB FILS KLINIKEN GmbH, Göppingen, Deutschland
| | - M Helm
- Klinik für Anästhesiologie & Intensivmedizin, Sektion Notfallmedizin, Bundeswehrkrankenhaus Ulm, Ulm, Deutschland
| | - C Lott
- Klinik für Anästhesiologie, Universitätsmedizin der Johannes Gutenberg-Universität Mainz, Mainz, Deutschland
| | - B W Böttiger
- Klinik für Anästhesiologie und Operative Intensivmedizin, Universitätsklinikum Köln, Köln, Deutschland
| | - M Bernhard
- Zentrale Notaufnahme, Universitätsklinikum Leipzig, Leipzig, Deutschland
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Kulla M, Friess M, Schellinger PD, Harth A, Busse O, Walcher F, Helm M. [Consideration of guidelines, recommendations and quality indicators for treatment of stroke in the dataset "Emergency Department" of DIVI]. Nervenarzt 2016; 86:1538-48. [PMID: 26248579 DOI: 10.1007/s00115-015-4396-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND The dataset "Emergency Department" of the German Interdisciplinary Association of Critical Care and Emergency Medicine (DIVI) has been developed during several expert meetings. Its goal is an all-encompassing documentation of the early clinical treatment of patients in emergency departments. Using the example of the index disease acute ischemic stroke (stroke), the aim was to analyze how far this approach has been fulfilled. MATERIAL AND METHODS In this study German, European and US American guidelines were used to analyze the extent of coverage of the datasets on current emergency department guidelines and recommendations from professional societies. In addition, it was examined whether the dataset includes recommended quality indicators (QI) for quality management (QM) and in a third step it was examined to what extent national provisions for billing are included. In each case a differentiation was made whether the respective rationale was primary, i.e. directly apparent or whether it was merely secondarily depicted by expertise. In the evaluation an additional differentiation was made between the level of recommendations and further quality relevant criteria. RESULTS The modular design of the emergency department dataset comprising 676 data fields is briefly described. A total of 401 individual fields, divided into basic documentation, monitoring and specific neurological documentation of the treatment of stroke patients were considered. For 247 data fields a rationale was found. Partially overlapping, 78.9 % of 214 medical recommendations in 3 guidelines and 85.8 % of the 106 identified quality indicators were primarily covered. Of the 67 requirements for billing of performance of services, 55.5 % are primarily part of the emergency department dataset. Through appropriate expertise and documentation by a board certified neurologist, the results can be improved to almost 100 %. CONCLUSION The index disease stroke illustrates that the emergency department dataset of the DIVI covers medical guidelines, especially 100 % of the German guidelines with a grade of recommendation. All necessary information to document the specialized stroke treatment procedure in the German diagnosis-related groups (DRG) system is also covered. The dataset is also suitable as a documentation tool of quality management, for example, to participate in the registry of the German Stroke Society (ADSR). Best results are obtained if the dataset is applied by a physician specialized in the treatment of patients with stroke (e.g. board certified neurologist). Finally the results show that changes in medical guidelines and recommendations for quality management as well as billing-relevant content should be implemented in the development of datasets for documentation to avoid duplicate documentation.
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Affiliation(s)
- M Kulla
- Klinik für Anästhesiologie und Intensivmedizin, Bundeswehrkrankhaus Ulm - Sektion Notfallmedizin, Akademisches Krankenhaus der Universität Ulm, Oberer Eselsberg 40, 89081, Ulm, Deutschland.
| | - M Friess
- Klinik für Anästhesiologie und Intensivmedizin, Bundeswehrkrankhaus Ulm - Sektion Notfallmedizin, Akademisches Krankenhaus der Universität Ulm, Oberer Eselsberg 40, 89081, Ulm, Deutschland
| | - P D Schellinger
- Neurologische Klinik und Neurogeriatrie, Johannes Wesling Klinikum Minden, Minden, Deutschland
| | - A Harth
- Klinik für Neurologie, Bundeswehrkrankenhaus Ulm, Akademisches Krankenhaus der Universität Ulm, Ulm, Deutschland
| | - O Busse
- Deutsche Schlaganfallgesellschaft und Deutsche Gesellschaft für Neurointensiv - und Notfallmedizin, Berlin, Deutschland
| | - F Walcher
- Klinik für Unfallchirurgie, Universitätsklinikum Magdeburg A.ö.R., Magdeburg, Deutschland
| | - M Helm
- Klinik für Anästhesiologie und Intensivmedizin, Bundeswehrkrankhaus Ulm - Sektion Notfallmedizin, Akademisches Krankenhaus der Universität Ulm, Oberer Eselsberg 40, 89081, Ulm, Deutschland
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Anderson CR, Collins D, Laursen T, Arave T, Helm M. Stability of Sodium Nitroprusside in 5% Dextrose Stored at 4°C in Polypropylene Syringes Protected from Light. Int J Pharm Compd 2016; 20:435-437. [PMID: 28339379] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Sodium nitroprusside is a potent vasodilator employed intraoperatively and within critical care areas. The photolabile pharmaceutical agent has been used for decades and various stability studies have been executed. Due to potential shortages and the desire to batch compound sodium nitroprusside at a concentration of 1 mg/mL in polypropylene syringes, a new stability study was performed. Chromatographic analysis was conducted on a C18 column, with elution via an aqueous phase of 0.01 M sodium phosphate monobasic, adjusted to pH 6.5 with sodium hydroxide, and methanol (97.5:2.5) at a rate of 1 mL/min, and subsequent ultraviolet detection at 210 nm. Triplicate determinations of four samples, stored under refrigeration at 4°C, were obtained initially and on days 2, 5, and 9. Turbidity and pH measurements were performed in conjunction with visual observation on days of chromatographic analysis. Results demonstrate that sodium nitroprusside compounded in 5% dextrose at a concentration of 1 mg/mL, stored at 4°C protected from light in polypropylene syringes, is physically and chemically stable for at least 9 days.
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Affiliation(s)
| | | | | | - Trevor Arave
- Primary Children's Hospital, Salt Lake City, Utah
| | - Michael Helm
- Primary Children's Hospital, Salt Lake City, Utah
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König-Otto JC, Mittendorff M, Winzer T, Kadi F, Malic E, Knorr A, Berger C, de Heer WA, Pashkin A, Schneider H, Helm M, Winnerl S. Slow Noncollinear Coulomb Scattering in the Vicinity of the Dirac Point in Graphene. Phys Rev Lett 2016; 117:087401. [PMID: 27588881 DOI: 10.1103/physrevlett.117.087401] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2015] [Indexed: 06/06/2023]
Abstract
The Coulomb scattering dynamics in graphene in energetic proximity to the Dirac point is investigated by polarization resolved pump-probe spectroscopy and microscopic theory. Collinear Coulomb scattering rapidly thermalizes the carrier distribution in k directions pointing radially away from the Dirac point. Our study reveals, however, that, in almost intrinsic graphene, full thermalization in all directions relying on noncollinear scattering is much slower. For low photon energies, carrier-optical-phonon processes are strongly suppressed and Coulomb mediated noncollinear scattering is remarkably slow, namely on a ps time scale. This effect is very promising for infrared and THz devices based on hot carrier effects.
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Affiliation(s)
- J C König-Otto
- Helmholtz-Zentrum Dresden-Rossendorf, P.O. Box 510119, 01314 Dresden, Germany
- Technische Universität Dresden, 01062 Dresden, Germany
| | - M Mittendorff
- University of Maryland, College Park, Maryland 20742, USA
| | - T Winzer
- Technische Universität Berlin, Hardenbergstraße 36, 10623 Berlin, Germany
| | - F Kadi
- Technische Universität Berlin, Hardenbergstraße 36, 10623 Berlin, Germany
| | - E Malic
- Chalmers University of Technology, SE-41296 Göteborg, Sweden
| | - A Knorr
- Technische Universität Berlin, Hardenbergstraße 36, 10623 Berlin, Germany
| | - C Berger
- Georgia Institute of Technology, Atlanta, Georgia 30332, USA
- Institut Néel, CNRS-Université Alpes, 38042 Grenoble, France
| | - W A de Heer
- Georgia Institute of Technology, Atlanta, Georgia 30332, USA
| | - A Pashkin
- Helmholtz-Zentrum Dresden-Rossendorf, P.O. Box 510119, 01314 Dresden, Germany
| | - H Schneider
- Helmholtz-Zentrum Dresden-Rossendorf, P.O. Box 510119, 01314 Dresden, Germany
| | - M Helm
- Helmholtz-Zentrum Dresden-Rossendorf, P.O. Box 510119, 01314 Dresden, Germany
- Technische Universität Dresden, 01062 Dresden, Germany
| | - S Winnerl
- Helmholtz-Zentrum Dresden-Rossendorf, P.O. Box 510119, 01314 Dresden, Germany
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Abstract
Thirty-nine patients with stable chronic bronchitis and emphysema were randomly allocated into two groups. Eight withdrew before the study and six during the study. One group received six weeks active outpatient rehabilitation, the other (control) group six weeks attendance without rehabilitation. Before entry, patients were examined to assess stability and measure arterial blood gases. On both entry and completion the following were recorded: smoking history; carboxyhaemoglobin; FEVI; six minute walking distance (6MD); the General Health Questionnaire (GHQ) and visual analogue scale (VAS) of breathlessness. The treatment group showed a significant (p > 0.01) reduction in GHQ score after rehabilitation, suggesting a decrease in psychiatric symptoms. In the control group, the GHQ score reduction was not statistically significant. The control group, but not the treatment group, showed a significant (p > 0.05) increase in 6MD. No significant difference was found in FEV1, VAS score, or the number of patients smoking after rehabilitation. Our rehabilitation programme appeared to benefit patients' psychological wellbeing, but this may be due to attendance at the groups rather than the rehabilitation programme per se. Underlying disease severity or perception of disability did not change.
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Affiliation(s)
| | - M. Helm
- Astley Ainslie Hospital, Edinburgh
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Kulla M, Josse F, Stierholz M, Hossfeld B, Lampl L, Helm M. Initial assessment and treatment of refugees in the Mediterranean Sea (a secondary data analysis concerning the initial assessment and treatment of 2656 refugees rescued from distress at sea in support of the EUNAVFOR MED relief mission of the EU). Scand J Trauma Resusc Emerg Med 2016; 24:75. [PMID: 27206483 PMCID: PMC4873997 DOI: 10.1186/s13049-016-0270-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Accepted: 05/13/2016] [Indexed: 12/01/2022] Open
Abstract
Background As a part of the European Union Naval Force – Mediterranean Operation Sophia (EUNAVFOR Med), the Federal Republic of Germany is contributing to avoid further loss of lives at sea by supplying two naval vessels. In the study presented here we analyse the medical requirements of such rescue missions, as well as the potential benefits of various additional monitoring devices in identifying sick/injured refugees within the primary onboard medical assessment process. Methods Retrospective analysis of the data collected between May – September 2015 from a German Naval Force frigate. Initial data collection focused on the primary medical assessment and treatment process of refugees rescued from distress at sea. Descriptive statistics, uni- and multivariate analysis were performed. The study has received a positive vote from the Ethics Commission of the University of Ulm, Germany (request no. 284/15) and has been registered in the German Register of Clinical Studies (no. DRKS00009535). Results A total of 2656 refugees had been rescued. 16.9 % of them were classified as “medical treatment required” within the initial onboard medical assessment process. In addition to the clinical assessment by an emergency physician, pulse rate (PR), core body temperature (CBT) and oxygen saturation (SpO2) were evaluated. Sick/injured refugees displayed a statistically significant higher PR (114/min vs. 107/min; p < .001) and CBT (37.1 °C vs. 36.7 °C; p < .001). There was no statistically significant difference in SpO2-values. The same results were found for the subgroup of patients classified as “treatment at emergency hospital required”. However, a much larger difference of the mean PR and CBT (35/min resp. 1.8 °C) was found when examining the subgroups of the corresponding refugee boats. A cut-off value of clinical importance could not be found. Predominant diagnoses have been dermatological diseases (55.4), followed by internal diseases (27.7) and trauma (12.1 %). None of the refugees classified as “healthy” within the primary medical assessment process changed to “medical treatment required” during further observation. Conclusions The initial medical assessment by an emergency physician has proved successful. PR, CBT and SpO2 didn’t have any clinical impact to improve the identification of sick/injured refugees within the primary onboard assessment process. Electronic supplementary material The online version of this article (doi:10.1186/s13049-016-0270-z) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- M Kulla
- Department of Anaesthesiology and Intensive Care Medicine, German Armed Forces Hospital Ulm, Section Emergency Medicine, Oberer Eselsberg 40, 89081, Ulm, Germany.
| | - F Josse
- Department of Anaesthesiology and Intensive Care Medicine, German Armed Forces Hospital Ulm, Section Emergency Medicine, Oberer Eselsberg 40, 89081, Ulm, Germany
| | - M Stierholz
- Frigate Schleswig-Holstein, Ship Medical Officer, Endraßstrasse, 26382, Wilhelmshaven, Germany
| | - B Hossfeld
- Department of Anaesthesiology and Intensive Care Medicine, German Armed Forces Hospital Ulm, Section Emergency Medicine, Oberer Eselsberg 40, 89081, Ulm, Germany
| | - L Lampl
- Department of Anaesthesiology and Intensive Care Medicine, German Armed Forces Hospital Ulm, Section Emergency Medicine, Oberer Eselsberg 40, 89081, Ulm, Germany
| | - M Helm
- Department of Anaesthesiology and Intensive Care Medicine, German Armed Forces Hospital Ulm, Section Emergency Medicine, Oberer Eselsberg 40, 89081, Ulm, Germany
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Kulla M, Kraus S, Walcher F, Somasundaram R, Wrede CE, Lampl L, Helm M. [Patients with Acute, Non-Traumatic Abdominal Pain in German Emergency Departments: A Prospective Monocentric Observation Study]. Zentralbl Chir 2016; 141:666-676. [PMID: 27135864 DOI: 10.1055/s-0042-102536] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Background: Up to 11 % of patients in an Emergency Department (ED) present with non-traumatic acute abdominal pain. Based on this presenting symptom, this study aimed to analyse how residents (surgery, internal medicine, anaesthesiology and other fields) working in an ED during their second and third year of education treat these patients. Material and Methods: We performed a prospective, monocentric observation study in an ED in accordance with the STROBE recommendations, following the recommendations from the Ethics Committee of the University of Ulm (application no. 335/12) and the Declaration of Helsinki. The hospital's data protection officer approved the study. During a 12-month period (Dec. 2012 to Dec. 2013), a random sample of patients with non-traumatic abdominal pain was obtained in the ED of a major German acute care hospital by an independent observer, who was not part of the ED team. In addition to demographic data, the study focused on analysing processes and patient care (including medical history taking and physical examinations). In addition, subgroups were defined (clinical background of the treating physician, severity pursuant to the Manchester Triage Score [MTS]). Results: 143 patients met the inclusion criteria. The clinical background of the physician had no influence on the reviewed processes such as medical history taking, initial examinations, the request of consultative examinations or diagnostic procedures. Patients triaged as "urgent" were treated significantly earlier than patients triaged as "non-urgent" (time to first physician contact 26 ± 24 vs. 46 ± 34 min, p < 0.001). However, the overall time spent in the ED was equal (210 ± 79 vs. 220 ± 114 min, p = 0.555). Yet the initially estimated urgency was correlated with the need for hospitalisation (share: 57 %). Conclusion: The overall compliance with standards of care was high. The clinical background (surgery, internal medicine, anaesthesiology, other fields) of the physician in charge of initial treatment had no influence on the reviewed processes.
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Affiliation(s)
- M Kulla
- Klinik für Anästhesiologie und Intensivmedizin - Sektion Notfallmedizin, Bundeswehrkrankenhaus Ulm, Deutschland
| | - S Kraus
- Klinik für Anästhesiologie und Intensivmedizin, Bundeswehrkrankenhaus Ulm, Deutschland
| | - F Walcher
- Klinik für Unfallchirurgie, Universitätsklinikum Magdeburg, Deutschland
| | - R Somasundaram
- Interdisziplinäre Rettungsstelle und Aufnahmestation, Charité - Universitätsmedizin Berlin - Campus Benjamin Franklin, Deutschland
| | - C E Wrede
- Interdisziplinäres Notfallzentrum mit Rettungsstelle, Helios Klinikum Berlin-Buch, Deutschland
| | - L Lampl
- Klinik für Anästhesiologie und Intensivmedizin, Bundeswehrkrankenhaus Ulm, Deutschland
| | - M Helm
- Klinik für Anästhesiologie und Intensivmedizin - Sektion Notfallmedizin, Bundeswehrkrankenhaus Ulm, Deutschland
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Hilbert-Carius P, Helm M, Lier H, Fischer M, Hofmann G, Lott C, Wurmb T, Bauer M, Winning J, Böttiger BW, Bernhard M. Um klar zu sehen, genügt oft ein Wechsel der Blickrichtung. Unfallchirurg 2016; 119:323-6. [DOI: 10.1007/s00113-016-0147-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Abstract
Hyperbranched polyether-based lipids with cleavable acetal units were obtained via copolymerization of the epoxide inimer 1-(glycidyloxy)ethyl ethylene glycol ether (GEGE) and glycidol, using anionic ring-opening polymerization.
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Affiliation(s)
- S. S. Müller
- Institute of Organic Chemistry
- Johannes Gutenberg University Mainz
- 55128 Mainz
- Germany
- Graduate School Materials Science in Mainz (MAINZ)
| | - T. Fritz
- Institute of Pharmacy and Biochemistry
- Johannes Gutenberg University Mainz
- 55128 Mainz
- Germany
| | - M. Gimnich
- Institute of Organic Chemistry
- Johannes Gutenberg University Mainz
- 55128 Mainz
- Germany
| | - M. Worm
- Institute of Organic Chemistry
- Johannes Gutenberg University Mainz
- 55128 Mainz
- Germany
| | - M. Helm
- Institute of Pharmacy and Biochemistry
- Johannes Gutenberg University Mainz
- 55128 Mainz
- Germany
| | - H. Frey
- Institute of Organic Chemistry
- Johannes Gutenberg University Mainz
- 55128 Mainz
- Germany
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Affiliation(s)
- F. Josse
- Klinik für Anästhesiologie und Intensivmedizin – Sektion Notfallmedizin, Bundeswehrkrankenhaus Ulm
| | - M. Helm
- Klinik für Anästhesiologie und Intensivmedizin – Sektion Notfallmedizin, Bundeswehrkrankenhaus Ulm
| | - M. Kulla
- Klinik für Anästhesiologie und Intensivmedizin – Sektion Notfallmedizin, Bundeswehrkrankenhaus Ulm
| | - B. Hossfeld
- Klinik für Anästhesiologie und Intensivmedizin – Sektion Notfallmedizin, Bundeswehrkrankenhaus Ulm
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