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Schümann K, Wilfling T, Paasche G, Schuon R, Robert S, Lenarz T, Schmidt W, Grabow N, Müller H, Momma C, Schmitz KP. Development of biodegradable stents for the treatment of Eustachian tube dysfunction. Current Directions in Biomedical Engineering 2018. [DOI: 10.1515/cdbme-2018-0121] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
AbstractTo provide an effective and safe therapy for chronic Eustachian tube dysfunction (ETD), biodegradable stents should be developed to restore important functions, e.g. middle ear ventilation and drainage. After defining general requirements specifications, stent designs of cardiovascular polymeric stents were modified according to dimensions and conditions of the Eustachian tube. Finite element simulations demonstrated the crimping capacity of the developed stent design and the ability of expansion in the specific geometry of the target location. Subsequent in vitro tests of stent prototypes showed satisfying properties concerning crimpability, expansion behavior and elastic recoil to demonstrate general feasibility. Further developments and additional testing will advance the implementation of a new treatment option of ETD.
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Affiliation(s)
- Kerstin Schümann
- 1Institute for Biomedical Engineering, Rostock University Medical Center,Rostock, Germany
| | - Tamara Wilfling
- 2Department of Otorhinolaryngology, Hannover Medical School,Hannover, Germany
| | - Gerrit Paasche
- 2Department of Otorhinolaryngology, Hannover Medical School,Hannover, Germany
| | - Robert Schuon
- 2Department of Otorhinolaryngology, Hannover Medical School,Hannover, Germany
| | - Schuon Robert
- 2Department of Otorhinolaryngology, Hannover Medical School,Hannover, Germany
| | - Thomas Lenarz
- 2Department of Otorhinolaryngology, Hannover Medical School,Hannover, Germany
| | - Wolfram Schmidt
- 1Institute for Biomedical Engineering, Rostock University Medical Center,Rostock, Germany
| | - Niels Grabow
- 1Institute for Biomedical Engineering, Rostock University Medical Center,Rostock, Germany
| | - Heinz Müller
- 3CORTRONIK GmbH, Friedrich- Barnewitz-Str. 4a,Rostock, Germany
| | - Carsten Momma
- 3CORTRONIK GmbH, Friedrich- Barnewitz-Str. 4a,Rostock, Germany
| | - Klaus-Peter Schmitz
- 4Institute for ImplantTechnology and Biomaterials, Institute for Biomedical Engineering, Rostock University Medical Center,Rostock, Germany
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Meyer S, Eichmann H, Menzel T, Nolte S, Wellegehausen B, Chichkov BN, Momma C. Phase-matched high-order difference-frequency mixing in plasmas. Phys Rev Lett 1996; 76:3336-3339. [PMID: 10060941 DOI: 10.1103/physrevlett.76.3336] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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Chichkov BN, Egbert A, Eichmann H, Momma C, Nolte S, Wellegehausen B. Soft-x-ray lasing to the ground states in low-charged oxygen ions. Phys Rev A 1995; 52:1629-1639. [PMID: 9912403 DOI: 10.1103/physreva.52.1629] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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Eichmann H, Egbert A, Nolte S, Momma C, Wellegehausen B, Becker W, Long S, McIver JK. Polarization-dependent high-order two-color mixing. Phys Rev A 1995; 51:R3414-R3417. [PMID: 9912117 DOI: 10.1103/physreva.51.r3414] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
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Eichmann H, Meyer S, Riepl K, Momma C, Wellegehausen B. Generation of short-pulse tunable xuv radiation by high-order frequency mixing. Phys Rev A 1994; 50:R2834-R2836. [PMID: 9911324 DOI: 10.1103/physreva.50.r2834] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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Momma C, Eichmann H, Tunnermann A, Simon P, Marowsky G, Wellegehausen B. Short-pulse amplification in an F2 gain module. Opt Lett 1993; 18:1180. [PMID: 19823327 DOI: 10.1364/ol.18.001180] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
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Momma C, Eichmann H, Jacobs H, Tünnermann A, Welling H, Wellegehausen B. Short-pulse amplification and gain dynamics of an ArF excimer amplifier. Opt Lett 1993; 18:516-518. [PMID: 19802186 DOI: 10.1364/ol.18.000516] [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] [Indexed: 05/28/2023]
Abstract
Subpicosecond pulses at 193 nm, generated by a nonresonant difference-frequency mixing process in xenon, have been amplified in an ArF excimer gain module to output energies of as much as 10 mJ. Investigations on the gain characteristics of the ArF excimer amplifier yield a saturation energy density of 1.9 mJ/cm(2) and a maximum small-signal gain coefficient of 0.15 cm(-1). Gain recovery measurements have been performed. A dominant gain recovery time of ~3 ns with indications of a small fast contribution in the picosecond range have been observed.
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Horii S, Momma C, Miyahara K, Maruyama T, Matsumoto M. Liquid chromatographic determination of three sulfonamides in animal tissue and egg. J Assoc Off Anal Chem 1990; 73:990-2. [PMID: 2289931] [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: 12/31/2022]
Abstract
Sulfonamides are widely used as a feed additive in animal production in Japan. The present paper is a determination of 3 sulfonamides: sulfamethazine (SMZ), sulfamonomethoxine [SMX, 4-amino-N-(3-methoxypyrazinyl)-benzenesulfonamide], and sulfadimethoxine (SDX) in animal tissue and egg by liquid chromatography (LC). Tissues were extracted with acetonitrile and fat was removed by liquid/liquid partition. The sulfonamides were purified by an ODS cartridge column; then each compound was separated by an ODS LC column and detected at 268 nm. Quantification levels were 0.02 ppm for SMZ and SMX, and 0.04 ppm for SDX; detection limits were 0.01 ppm for SMZ and SMX, and 0.02 ppm for SDX. Calibration curves were linear between 2 and 40 ng for SMZ and SMX, and between 4 and 80 ng for SDX. Recoveries from muscle and egg samples spiked with 1-2 micrograms/10 g were 81-98%.
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Affiliation(s)
- S Horii
- Tokyo Metropolitan Research Laboratory of Public Health, Department of Food Hygiene and Nutrition, Japan
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