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Rückert J, Michaelis A, Markel F, Kalden P, Löffelbein F, Klehs S, Dähnert I, Schöffl I, Rottermann K, Paech C. Open Field Exercise Testing in Pediatric Congenital Heart Disease Patients: A Subsumption of Cardiovascular Parameters. Pediatr Cardiol 2023; 44:1831-1838. [PMID: 37486362 PMCID: PMC10520100 DOI: 10.1007/s00246-023-03226-6] [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] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Accepted: 07/02/2023] [Indexed: 07/25/2023]
Abstract
Heart failure is a common phenomenon in congenital heart disease patients. Cardiopulmonary exercise testing is used for a reliable assessment of heart failure but is still challenging, especially for young children. Implementing mobile cardiopulmonary exercise testing (CPET) can close that diagnostic gap. While average values for healthy children have already been published, this study aims to describe typical ranges of cardiovascular performance parameters of young children with congenital heart disease performing an 8-min running cardiopulmonary exercise test. Children aged 4-8 years with common congenital heart defects after corrective surgery (Tetralogy of Fallot; transposition of the great arteries and univentricular hearts after palliation) were included. The outdoor running protocol consisted of slow walking, slow jogging, fast jogging, and maximum speed running. Each exercise was performed for 2 min, except the last, in which children were instructed to keep up maximal speed as long as possible. A total of 78 children (45 male/33 female, mean age 6,24) with congenital heart disease participated in the study, of which 97% completed the CPET successfully. A detailed description of participating patients, including data on cardiac function and subjective fitness levels, is given to help physicians use this method to classify their patients. This study presents a typical range for cardiovascular performance parameters in a population of 4-8-year-old children with congenital heart disease tested in a newly developed outdoor running protocol for CPET.
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Affiliation(s)
- J. Rückert
- Department for Pediatric Cardiology, University of Leipzig - Heart Center, Strümpellstr. 39, 04289 Leipzig, Germany
| | - A. Michaelis
- Department for Pediatric Cardiology, University of Leipzig - Heart Center, Strümpellstr. 39, 04289 Leipzig, Germany
| | - F. Markel
- Department for Pediatric Cardiology, University of Leipzig - Heart Center, Strümpellstr. 39, 04289 Leipzig, Germany
| | - P. Kalden
- Department for Pediatric Cardiology, University of Leipzig - Heart Center, Strümpellstr. 39, 04289 Leipzig, Germany
| | - F. Löffelbein
- Department for Pediatric Cardiology, University of Leipzig - Heart Center, Strümpellstr. 39, 04289 Leipzig, Germany
| | - S. Klehs
- Department for Pediatric Cardiology, University of Leipzig - Heart Center, Strümpellstr. 39, 04289 Leipzig, Germany
| | - I. Dähnert
- Department for Pediatric Cardiology, University of Leipzig - Heart Center, Strümpellstr. 39, 04289 Leipzig, Germany
| | - I. Schöffl
- Department of Pediatric Cardiology, University Hospital Erlangen, Loschbergstraße 15, 91054 Erlangen, Germany
| | - K. Rottermann
- Department of Pediatric Cardiology, University Hospital Erlangen, Loschbergstraße 15, 91054 Erlangen, Germany
| | - C. Paech
- Department for Pediatric Cardiology, University of Leipzig - Heart Center, Strümpellstr. 39, 04289 Leipzig, Germany
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Teich L, Franke D, Michaelis A, Dähnert I, Gebauer RA, Markel F, Paech C. Development of an AI based automated analysis of pediatric Apple Watch iECGs. Front Pediatr 2023; 11:1185629. [PMID: 37360371 PMCID: PMC10286860 DOI: 10.3389/fped.2023.1185629] [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] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Accepted: 04/26/2023] [Indexed: 06/28/2023] Open
Abstract
Introduction The Apple Watch valuably records event-based electrocardiograms (iECG) in children, as shown in recent studies by Paech et al. In contrast to adults, though, the automatic heart rhythm classification of the Apple Watch did not provide satisfactory results in children. Therefore, ECG analysis is limited to interpretation by a pediatric cardiologist. To surmount this difficulty, an artificial intelligence (AI) based algorithm for the automatic interpretation of pediatric Apple Watch iECGs was developed in this study. Methods A first AI-based algorithm was designed and trained based on prerecorded and manually classified i.e., labeled iECGs. Afterward the algorithm was evaluated in a prospectively recruited cohort of children at the Leipzig Heart Center. iECG evaluation by the algorithm was compared to the 12-lead-ECG evaluation by a pediatric cardiologist (gold standard). The outcomes were then used to calculate the sensitivity and specificity of the Apple Software and the self-developed AI. Results The main features of the newly developed AI algorithm and the rapid development cycle are presented. Forty-eight pediatric patients were enrolled in this study. The AI reached a specificity of 96.7% and a sensitivity of 66.7% for classifying a normal sinus rhythm. Conclusion The current study presents a first AI-based algorithm for the automatic heart rhythm classification of pediatric iECGs, and therefore provides the basis for further development of the AI-based iECG analysis in children as soon as more training data are available. More training in the AI algorithm is inevitable to enable the AI-based iECG analysis to work as a medical tool in complex patients.
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Affiliation(s)
- L. Teich
- Department for Pediatric Cardiology, University of Leipzig - Heart Center, Leipzig, Germany
| | - D. Franke
- Arbeitskreis Integrierte Informationssysteme, Westsächsische Hochschule Zwickau, Zwickau, Saxony, Germany
| | - A. Michaelis
- Department for Pediatric Cardiology, University of Leipzig - Heart Center, Leipzig, Germany
| | - I. Dähnert
- Department for Pediatric Cardiology, University of Leipzig - Heart Center, Leipzig, Germany
| | - R. A. Gebauer
- Department for Pediatric Cardiology, University of Leipzig - Heart Center, Leipzig, Germany
| | - F. Markel
- Department for Pediatric Cardiology, University of Leipzig - Heart Center, Leipzig, Germany
| | - C. Paech
- Department for Pediatric Cardiology, University of Leipzig - Heart Center, Leipzig, Germany
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Pätz C, Michaelis A, Markel F, Löffelbein F, Dähnert I, Gebauer RA, Paech C. Accuracy of the Apple Watch Oxygen Saturation Measurement in Adults and Children with Congenital Heart Disease. Pediatr Cardiol 2023; 44:333-343. [PMID: 35995951 DOI: 10.1007/s00246-022-02987-w] [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] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/21/2022] [Accepted: 08/08/2022] [Indexed: 02/07/2023]
Abstract
As new customer health devices have been spread throughout the consumer market in recent years, it now needs to be evaluated if they also fulfill the requirements of clinical use. The Apple Watch Series 6 provides a new health feature with its oxygen saturation measurement. The aim of this prospective, investigator-initiated, single-arm study was to compare transcutaneous oxygen saturation measurements using the Apple Watch 6 with the conventional method of pulse oximetry in patients with congenital heart disease. Patients of any age presenting at the Leipzig Heart Center, Department for pediatric cardiology, were included. After obtaining informed consent, the routine oxygen saturation measurement with the pulse oximeter was taken and simultaneously three measurements with the Apple Watch. A total of 508 patients were enrolled. Comparing children and adults in terms of measurement success shows a statistically significant difference with a higher proportion of unsuccessful measurements in children, but no difference concerning correct versus incorrect Apple Watch measurements. Noticeable, strapping on the watch properly around the patient's wrists significantly improved the measurements compared to a watch only laid on. The study demonstrated that oxygen saturation measurement with the Apple Watch 6 is not yet up to the medical standard of pulse oximetry, too large a proportion of the measurements remain either unsuccessful or incorrect. While a high proportion of unsuccessful measurements in children can be attributed to movement, the cause in adults usually remains unclear. Further influencing factors on a correct, or successful measurement could not be found.
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Affiliation(s)
- C Pätz
- Department for Pediatric Cardiology, Heart Center Leipzig, University of Leipzig, Strümpellstr. 39, 04289, Leipzig, Germany
| | - A Michaelis
- Department for Pediatric Cardiology, Heart Center Leipzig, University of Leipzig, Strümpellstr. 39, 04289, Leipzig, Germany
| | - F Markel
- Department for Pediatric Cardiology, Heart Center Leipzig, University of Leipzig, Strümpellstr. 39, 04289, Leipzig, Germany
| | - F Löffelbein
- Department for Pediatric Cardiology, Heart Center Leipzig, University of Leipzig, Strümpellstr. 39, 04289, Leipzig, Germany
| | - I Dähnert
- Department for Pediatric Cardiology, Heart Center Leipzig, University of Leipzig, Strümpellstr. 39, 04289, Leipzig, Germany
| | - R A Gebauer
- Department for Pediatric Cardiology, Heart Center Leipzig, University of Leipzig, Strümpellstr. 39, 04289, Leipzig, Germany
| | - C Paech
- Department for Pediatric Cardiology, Heart Center Leipzig, University of Leipzig, Strümpellstr. 39, 04289, Leipzig, Germany.
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Michaelis A, Dähnert I, Gebauer RA, Paech C. Case Report of a 4-Year-Old Girl Presenting Cardiomyopathy Due to a Permanent Junctional Reciprocating Tachycardia. Thorac Cardiovasc Surg 2022. [DOI: 10.1055/s-0042-1743002] [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: 10/18/2022]
Affiliation(s)
- A. Michaelis
- Kinderkardiologie, Herzzentrum Leipzig, Leipzig, Deutschland
| | - I. Dähnert
- Kinderkardiologie, Herzzentrum Leipzig, Leipzig, Deutschland
| | - R. A. Gebauer
- Kinderkardiologie, Herzzentrum Leipzig, Leipzig, Deutschland
| | - C. Paech
- Universitätsklinik für Kinderkardiologie, Leipzig, Deutschland
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Kalden P, Schoeffl I, Rottermann K, Löffelbein F, Michaelis A, Markel F, Brosig S, Gebauer RA, Dähnert I, Paech C. Reference Values for Mobile Open Field Stress Testing in Healthy Children Aged 4 to 8 Years. Thorac Cardiovasc Surg 2022. [DOI: 10.1055/s-0042-1742960] [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: 10/18/2022]
Affiliation(s)
- P. Kalden
- Universitätsklinik für Kinderkardiologie, Heart Center Leipzig, Leipzig, Deutschland
| | - I. Schoeffl
- Department of Pediatric Cardiology, University Hospital Erlangen, Erlangen, Deutschland
| | | | - F. Löffelbein
- Universitätsklinik für Kinderkardiologie, Leipzig, Deutschland
| | - A. Michaelis
- Kinderkardiologie, Herzzentrum Leipzig, Leipzig, Deutschland
| | - F. Markel
- Universitätsklinik für Kinderkardiologie, Leipzig, Deutschland
| | - S. Brosig
- Kinderkardiologie, Herzzentrum Leipzig, Leipzig, Deutschland
| | - R. A. Gebauer
- Kinderkardiologie, Herzzentrum Leipzig, Leipzig, Deutschland
| | - I. Dähnert
- Kinderkardiologie, Herzzentrum Leipzig, Leipzig, Deutschland
| | - C. Paech
- Universitätsklinik für Kinderkardiologie, Leipzig, Deutschland
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Wroe EB, Nhlema B, Dunbar EL, Kulinkina AV, Kachimanga C, Aron M, Dullie L, Makungwa H, Chabwera B, Phiri B, Nazimera L, Ndarama EPL, Michaelis A, McBain R, Brown C, Palazuelos D, Lilford R, Watson SI. A household-based community health worker programme for non-communicable disease, malnutrition, tuberculosis, HIV and maternal health: a stepped-wedge cluster randomised controlled trial in Neno District, Malawi. BMJ Glob Health 2021; 6:bmjgh-2021-006535. [PMID: 34526321 PMCID: PMC8444244 DOI: 10.1136/bmjgh-2021-006535] [Citation(s) in RCA: 1] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2021] [Accepted: 08/27/2021] [Indexed: 11/04/2022] Open
Abstract
BACKGROUND Community health worker (CHW) programmes are a valuable component of primary care in resource-poor settings. The evidence supporting their effectiveness generally shows improvements in disease-specific outcomes relative to the absence of a CHW programme. In this study, we evaluated expanding an existing HIV and tuberculosis (TB) disease-specific CHW programme into a polyvalent, household-based model that subsequently included non-communicable diseases (NCDs), malnutrition and TB screening, as well as family planning and antenatal care (ANC). METHODS We conducted a stepped-wedge cluster randomised controlled trial in Neno District, Malawi. Six clusters of approximately 20 000 residents were formed from the catchment areas of 11 healthcare facilities. The intervention roll-out was staggered every 3 months over 18 months, with CHWs receiving a 5-day foundational training for their new tasks and assigned 20-40 households for monthly (or more frequent) visits. FINDINGS The intervention resulted in a decrease of approximately 20% in the rate of patients defaulting from chronic NCD care each month (-0.8 percentage points (pp) (95% credible interval: -2.5 to 0.5)) while maintaining the already low default rates for HIV patients (0.0 pp, 95% CI: -0.6 to 0.5). First trimester ANC attendance increased by approximately 30% (6.5pp (-0.3, 15.8)) and paediatric malnutrition case finding declined by 10% (-0.6 per 1000 (95% CI -2.5 to 0.8)). There were no changes in TB programme outcomes, potentially due to data challenges. INTERPRETATION CHW programmes can be successfully expanded to more comprehensively address health needs in a population, although programmes should be carefully tailored to CHW and health system capacity.
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Affiliation(s)
- Emily B Wroe
- Partners In Health, Neno, Malawi .,Division of Global Health Equity, Brigham and Women's Hospital, Boston, Massachusetts, USA.,Department of Global Health and Social Medicine, Harvard Medical School, Boston, MA, USA
| | | | - Elizabeth L Dunbar
- Partners In Health, Neno, Malawi.,Human Centered Design & Engineering, University of Washington, Seattle, Washington, USA
| | - Alexandra V Kulinkina
- Partners In Health, Neno, Malawi.,Swiss Tropical and Public Health Institute, Basel, Switzerland.,University of Basel, Basel, Switzerland
| | | | | | | | | | | | | | | | | | | | - Ryan McBain
- Partners In Health, Boston, Massachusetts, USA.,RAND, Boston, Massachusetts, USA
| | | | - Daniel Palazuelos
- Division of Global Health Equity, Brigham and Women's Hospital, Boston, Massachusetts, USA.,Department of Global Health and Social Medicine, Harvard Medical School, Boston, MA, USA.,Partners In Health, Boston, Massachusetts, USA
| | - Richard Lilford
- Institute of Applied Health Research, University of Birmingham, Birmingham, UK
| | - Samuel I Watson
- Institute of Applied Health Research, University of Birmingham, Birmingham, UK
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Voigt K, Heubner C, Schneider M, Michaelis A. Formation mechanism of electrodeposited Sb/Sb2O3 micro-composites. Electrochim Acta 2021. [DOI: 10.1016/j.electacta.2020.137430] [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: 10/23/2022]
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8
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Michaelis A, Wagner F, Riede FT, Dähnert I, Schröter T, Pfannmüller B, Weidenbach M, Gebauer R, Paech C. Performance of Pacemaker Leads in Alternative Lead Positions after Tricuspid Valve Replacement. Thorac Cardiovasc Surg 2020. [DOI: 10.1055/s-0040-1705547] [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: 10/24/2022]
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9
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Heubner C, Langklotz U, Lämmel C, Schneider M, Michaelis A. Electrochemical single-particle measurements of electrode materials for Li-ion batteries: Possibilities, insights and implications for future development. Electrochim Acta 2020. [DOI: 10.1016/j.electacta.2019.135160] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [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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10
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Schneider M, Šimůnková L, Junker N, Michaelis A. Quantitative detection of anodic oxygen evolution on solid state sintered silicon carbide under near ECM conditions. J Solid State Electrochem 2020. [DOI: 10.1007/s10008-019-04479-z] [Citation(s) in RCA: 3] [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: 10/25/2022]
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Dunbar EL, Wroe EB, Nhlema B, Kachimanga C, Gupta R, Taylor C, Michaelis A, Cundale K, Dullie L, Jumbe A, Nazimera L, McBain R, Lilford RJ, Watson SI. Evaluating the impact of a community health worker programme on non-communicable disease, malnutrition, tuberculosis, family planning and antenatal care in Neno, Malawi: protocol for a stepped-wedge, cluster randomised controlled trial. BMJ Open 2018; 8:e019473. [PMID: 30007924 PMCID: PMC6089278 DOI: 10.1136/bmjopen-2017-019473] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
INTRODUCTION This protocol concerns the implementation and evaluation of an intervention designed to realign the existing cadre of community health workers (CHWs) in Neno district, Malawi to better support the care needs of the clients they serve. The proposed intervention is a 'Household Model' where CHWs will be reassigned to households, rather than to specific patients with HIV and/or tuberculosis (TB). METHODS AND ANALYSIS Using a stepped-wedge, cluster-randomised design, this study investigates whether high HIV retention rates can be replicated for non-communicable diseases (NCDs), and the model's impact on TB and paediatric malnutrition case finding, as well as the uptake of family planning and antenatal care. Eleven sites (health centres and hospitals) were arranged into six clusters (average cluster population 21 800). Primary outcomes include retention in care for HIV and chronic NCDs, TB case finding, paediatric malnutrition case finding, and utilisation of early and complete antenatal care. Clinical outcomes are based on routinely collected data from the Ministry of Health's District Health Information System 2 and an OpenMRS electronic medical record supported by Partners In Health. Additionally, semistructured qualitative interviews with various stakeholders will assess community perceptions and context of the Household Model. ETHICS AND DISSEMINATION Ethics approval has been obtained from the Malawian National Health Science Research Committee (#16/11/1694) in Lilongwe, Malawi; Partners Healthcare Human Research Committee (#2017P000548/PHS) in Somerville, Massachusetts; and the Biomedical and Scientific Research Ethics Sub-Committee (REGO-2017-2060) at the University of Warwick in Coventry, UK. Dissemination will include manuscripts for peer-reviewed publication as well as a full report detailing the findings of the intervention for the Malawian Ministry of Health. TRIAL REGISTRATION NUMBER NCT03106727. PRIMARY SPONSOR Partners In Health | Abwenzi Pa Za Umoyo P.O. Box 56, Neno, Malawi. Protocol Version 4, March 2018.
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Affiliation(s)
- Elizabeth L Dunbar
- Abwenzi Pa Za Umoyo/Partners In Health, Neno, Malawi
- Partners In Health Liberia, Harper, Liberia
| | - Emily B Wroe
- Abwenzi Pa Za Umoyo/Partners In Health, Neno, Malawi
| | | | | | - Ravi Gupta
- Abwenzi Pa Za Umoyo/Partners In Health, Neno, Malawi
| | | | | | - Katie Cundale
- Abwenzi Pa Za Umoyo/Partners In Health, Neno, Malawi
| | | | | | | | - Ryan McBain
- Partners In Health, Boston, Massachusetts, USA
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Heubner C, Liebmann T, Schneider M, Michaelis A. Recent insights into the electrochemical behavior of blended lithium insertion cathodes: A review. Electrochim Acta 2018. [DOI: 10.1016/j.electacta.2018.02.165] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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Lämmel C, Schneider M, Heubner C, Beckert W, Michaelis A. Investigations of burning phenomena during the hard anodising of aluminium by local in-operando temperature measurements. Electrochim Acta 2017. [DOI: 10.1016/j.electacta.2017.07.167] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Schneider M, Liebmann T, Langklotz U, Michaelis A. Microelectrochemical investigation of anodic oxide formation on the aluminum alloy AA2024. Electrochim Acta 2017. [DOI: 10.1016/j.electacta.2017.07.160] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [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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Heubner C, Heiden S, Schneider M, Michaelis A. In-situ preparation and electrochemical characterization of submicron sized NaFePO4 cathode material for sodium-ion batteries. Electrochim Acta 2017. [DOI: 10.1016/j.electacta.2017.02.107] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [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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Affiliation(s)
| | - C. Lämmel
- Fraunhofer IKTS Dresden; Dresden 01277 Germany
| | - R. Hübner
- Helmholtz-Zentrum Dresden-Rossendorf; Dresden 01328 Germany
| | - U. Gierth
- Fraunhofer IKTS Dresden; Dresden 01277 Germany
| | - A. Michaelis
- Fraunhofer IKTS Dresden; Dresden 01277 Germany
- Institut für Werkstoffwissenschaft; TU Dresden; Dresden 01069 Germany
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Heubner C, Langklotz U, Schneider M, Michaelis A. Analysis of the counter-electrode potential in a 3-electrode lithium ion battery cell. J Electroanal Chem (Lausanne) 2015. [DOI: 10.1016/j.jelechem.2015.10.037] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [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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Conze S, Veremchuk I, Reibold M, Matthey B, Michaelis A, Grin Y, Kinski I. Magnéli phases Ti4O7 and Ti8O15 and their carbon nanocomposites via the thermal decomposition-precursor route. J SOLID STATE CHEM 2015. [DOI: 10.1016/j.jssc.2015.04.037] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Afari H, Hirschhorn LR, Michaelis A, Barker P, Sodzi-Tettey S. Quality improvement in emergency obstetric referrals: qualitative study of provider perspectives in Assin North District, Ghana. BMJ Open 2014; 4:e005052. [PMID: 24833695 PMCID: PMC4025473 DOI: 10.1136/bmjopen-2014-005052] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
OBJECTIVE To describe healthcare worker (HCW)-identified system-based bottlenecks and the value of local engagement in designing strategies to improve referral processes related to emergency obstetric care in rural Ghana. DESIGN Qualitative study using semistructured interviews of participants to obtain provider narratives. SETTING Referral systems in obstetrics in Assin North Municipal Assembly, a rural district in Ghana. This included one district hospital, six health centres and four local health posts. This work was embedded in an ongoing quality improvement project in the district addressing barriers to existing referral protocols to lessen delays. PARTICIPANTS 18 HCWs (8 midwives, 4 community health officers, 3 medical assistants, 2 emergency room nurses, 1 doctor) at different facility levels within the district. RESULTS We identified important gaps in referral processes in Assin North, with the most commonly noted including recognising danger signs, alerting receiving units, accompanying critically ill patients, documenting referral cases and giving and obtaining feedback on referred cases. Main root causes identified by providers were in four domains: (1) transportation, (2) communication, (3) clinical skills and management and (4) standards of care and monitoring, and suggested interventions that target these barriers. Mapping these challenges allowed for better understanding of next steps for developing comprehensive, evidence-based solutions to identified referral gaps within the district. CONCLUSIONS Providers are an important source of information on local referral delays and in the development of approaches to improvement responsive to these gaps. Better engagement of HCWs can help to identify and evaluate high-impact holistic interventions to address faulty referral systems which result in poor maternal outcomes in resource-poor settings. These perspectives need to be integrated with patient and community perspectives.
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Affiliation(s)
| | - Lisa R Hirschhorn
- Harvard Medical School, Boston, Massachusetts, USA
- Partners in Health, Boston, Massachusetts, USA
| | | | - Pierre Barker
- Institute for Healthcare Improvement, Boston, Massachusetts, USA
| | - Sodzi Sodzi-Tettey
- Institute for Healthcare Improvement, Boston, Massachusetts, USA
- Project Fives Alive!/Institute for Healthcare Improvement, Accra, Ghana
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Kudelka S, Michaelis A, Schultze J. Electrochemical Characterisation of Oxide Layers on Single Grains of a Polycrystalline Ti-Sample. ACTA ACUST UNITED AC 2014. [DOI: 10.1002/bbpc.199500025] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Schneider M, Schubert N, Höhn S, Michaelis A. Anodic dissolution behaviour and surface texture development of cobalt under electrochemical machining conditions. Electrochim Acta 2013. [DOI: 10.1016/j.electacta.2013.05.070] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Affiliation(s)
- M. Schneider
- Fraunhofer IKTS Dresden; Winterbergstr. 28 01277 Dresden Germany
| | - C. Lämmel
- Fraunhofer IKTS Dresden; Winterbergstr. 28 01277 Dresden Germany
| | - C. Heubner
- Fraunhofer IKTS Dresden; Winterbergstr. 28 01277 Dresden Germany
| | - A. Michaelis
- Fraunhofer IKTS Dresden; Winterbergstr. 28 01277 Dresden Germany
- TU Dresden; Institut für Werkstoffwissenschaft; Helmholtzstr. 7 01069 Dresden Germany
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Schneider M, Langklotz U, Michaelis A. Spectroscopic reflectometry as in-operando
method for thickness determination of anodic oxide films on titanium. SURF INTERFACE ANAL 2013. [DOI: 10.1002/sia.5262] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- M. Schneider
- Fraunhofer IKTS; Winterbergstr. 28 01277 Dresden FRG
| | - U. Langklotz
- TU Dresden, Inst. of Material Science; Helmholtzstr.7 01067 Dresden FRG
| | - A. Michaelis
- Fraunhofer IKTS; Winterbergstr. 28 01277 Dresden FRG
- TU Dresden, Inst. of Material Science; Helmholtzstr.7 01067 Dresden FRG
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Schneider M, Schroth S, Richter S, Höhn S, Schubert N, Michaelis A. In-situ investigation of the interplay between microstructure and anodic copper dissolution under near-ECM conditions—Part 2: The transpassive state. Electrochim Acta 2012. [DOI: 10.1016/j.electacta.2012.03.066] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Schneider M, Schroth S, Richter S, Höhn S, Schubert N, Michaelis A. In-situ investigation of the interplay between microstructure and anodic copper dissolution under near-ECM conditions – Part 1: The active state. Electrochim Acta 2011. [DOI: 10.1016/j.electacta.2011.06.075] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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28
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Sauchuk V, Megel S, Girdauskaite E, Trofimenko N, Kusnezoff M, Michaelis A. Influence of protective layers on SOFC operation. RUSS J ELECTROCHEM+ 2011. [DOI: 10.1134/s1023193511050107] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Affiliation(s)
- R. Nemani
- NASA Ames Research Center, Moffett Field, Calif., USA
| | - P. Votava
- California State University, Monterey Bay, Seaside, USA
| | - A. Michaelis
- California State University, Monterey Bay, Seaside, USA
| | - F. Melton
- California State University, Monterey Bay, Seaside, USA
| | - C. Milesi
- California State University, Monterey Bay, Seaside, USA
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Schneider M, Langklotz U, Michaelis A. Thickness determination of thin anodic titanium oxide films-a comparison between coulometry and reflectometry. SURF INTERFACE ANAL 2011. [DOI: 10.1002/sia.3736] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Elschner C, Kusnezoff M, Ziesche S, Paepcke A, Michaelis A. New method to determine diffusion coefficients and surface rate constants in mixed ionic electronic conductors. J Memb Sci 2010. [DOI: 10.1016/j.memsci.2010.07.010] [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: 11/17/2022]
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32
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Jahn M, Michaelis A, Pohl M, Schreck C. Schaumkeramik als Katalysatorsystem. CHEM-ING-TECH 2010. [DOI: 10.1002/cite.201050545] [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: 11/11/2022]
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Marschallek F, Adler J, Böttge D, Füssel A, Jahn M, Michaelis A. Verbrennung in porösem SiC: Beiträge zu Prozessabsicherung und Dauerstabilität. CHEM-ING-TECH 2010. [DOI: 10.1002/cite.201050524] [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: 11/11/2022]
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Pulerwitz J, Michaelis A, Weiss E, Brown L, Mahendra V. Reducing HIV-related stigma: lessons learned from Horizons research and programs. Public Health Rep 2010; 125:272-81. [PMID: 20297756 DOI: 10.1177/003335491012500218] [Citation(s) in RCA: 115] [Impact Index Per Article: 8.2] [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
Since the early years of the human immunodeficiency virus (HIV) epidemic, stigma has been understood to be a major barrier to successful HIV prevention, care, and treatment. This article highlights findings from more than 10 studies in Asia, Africa, and Latin America-conducted from 1997 through 2007 as part of the Horizons program-that have contributed to clarifying the relationship between stigma and HIV, determining how best to measure stigma among varied populations, and designing and evaluating the impact of stigma reduction-focused program strategies. Studies showed significant associations between HIV-related stigma and less use of voluntary counseling and testing, less willingness to disclose test results, and incorrect knowledge about transmission. Programmatic lessons learned included how to assist institutions with recognizing stigma, the importance of confronting both fears of contagion and negative social judgments, and how best to engage people living with HIV in programs. The portfolio of work reveals the potential and importance of directly addressing stigma reduction in HIV programs.
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Affiliation(s)
- Julie Pulerwitz
- Program for Appropriate Technology in Health, Washington, DC, USA.
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Schenk KD, Michaelis A, Sapiano TN, Brown L, Weiss E. Improving the lives of vulnerable children: implications of Horizons research among orphans and other children affected by AIDS. Public Health Rep 2010; 125:325-36. [PMID: 20297761 DOI: 10.1177/003335491012500223] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
From 1997 through 2007, the Horizons program conducted research to inform the care and support of children who had been orphaned and rendered vulnerable by acquired immunodeficiency syndrome in sub-Saharan Africa. Horizons conducted studies in Kenya, Malawi, Rwanda, South Africa, Uganda, Zambia, and Zimbabwe. Research included both diagnostic studies exploring the circumstances of families and communities affected by human immunodeficiency virus (HIV) and evaluations of pioneering intervention strategies. Interventions found to be supportive of families included succession planning for families with an HIV-positive parent, training and supporting youth as caregivers, and youth mentorship for child-headed households. Horizons researchers developed tools to assess the psychosocial well-being of children affected by HIV and outlined key ethical guidelines for conducting research among children. The design, implementation, and evaluation of community-based interventions for orphans and vulnerable children continue to be a key gap in the evidence base.
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Pulerwitz J, Michaelis A, Verma R, Weiss E. Addressing gender dynamics and engaging men in HIV programs: lessons learned from Horizons research. Public Health Rep 2010; 125:282-92. [PMID: 20297757 DOI: 10.1177/003335491012500219] [Citation(s) in RCA: 117] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
In the field of human immunodeficiency virus (HIV) prevention, there has been increasing interest in the role that gender plays in HIV and violence risk, and in successfully engaging men in the response. This article highlights findings from more than 10 studies in Asia, Africa, and Latin America--conducted from 1997 through 2007 as part of the Horizons program--that have contributed to understanding the relationship between gender and men's behaviors, developing useful measurement tools for gender norms, and designing and evaluating the impact of gender-focused program strategies. Studies showed significant associations between support for inequitable norms and risk, such as more partner violence and less condom use. Programmatic lessons learned ranged from insights into appropriate media messages, to strategies to engage men in critically reflecting upon gender inequality, to the qualities of successful program facilitators. The portfolio of work reveals the potential and importance of directly addressing gender dynamics in HIV- and violence-prevention programs for both men and women.
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Affiliation(s)
- Julie Pulerwitz
- Program for Appropriate Technology in Health, Washington, DC, USA.
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Schneider M, Langklotz U, Michaelis A, Arnold B. Microelectrochemical investigation on aluminium-steel friction welds. SURF INTERFACE ANAL 2010. [DOI: 10.1002/sia.3175] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Abstract
The objectives of this study were to identify risk and protective factors for engaging in unsafe sex among orphans and non-orphans and to explore whether risk and protection differs by gender and orphan status. The study was carried out in Kisesa ward, in the Mwanza region of Northwest Tanzania. A combination of in-depth interviews and focus group discussions were used to collect data from girls and boys as well as from the female caregivers of orphans. Findings revealed that among young people who reported having unsafe sex, those who were female orphans were more likely to state that they 'had to have sex' to acquire food and clothing for their households. Caregivers believed that many young people who engage in sexual-risk behaviours do so because they are not provided with adequate supervision and moral guidance. The study suggests that programmes may need to target both girls and young women and their caregivers and create access to education and decent work opportunities.
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Affiliation(s)
- Kristin Mmari
- Johns Hopkins Bloomberg School of Public Health, Maryland, USA.
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Schroth S, Schneider M, Mayer - Uhma T, Michaelis A, Klemm V. Investigation of thin oxide films on titanium for capacitor applications. SURF INTERFACE ANAL 2008. [DOI: 10.1002/sia.2708] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Chen YX, Cabana B, Kivel N, Pieniaszek H, Gilman S, Michaelis A. Lack of effect of rifalazil on ethinyl estradiol pharmacokinetics in healthy postmenopausal women. Int J Clin Pharmacol Ther 2007; 45:418-22. [PMID: 17725249 DOI: 10.5414/cpp45418] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Rifalazil, a second-generation rifamycin, is being evaluated for the treatment of sexually transmitted disease and gastrointestinal infections. We determined whether rifalazil influences CYP3A4 metabolism by studying the effect of a single oral, 25 mg dose of rifalazil administered to healthy postmenopausal women, on the steady-state pharmacokinetics (PK) of ethinyl estradiol (EE) during administration of Ortho-Novum 1/35 (EE/NET). Noncompartmental PK and sequential statistical analyses were performed to establish if and when subjects achieved steady-state EE plasma concentrations and to determine whether this steady state was altered by rifalazil administration. The geometric mean ratios for the difference between EE alone and following rifalazil for EE Cmax, AUC(0-24) and Cmin were 105.9, 104.4 and 105.0, respectively. The 90% confidence intervals for each ratio fell within 80 - 125% of the reference treatment indicating no significant difference in the PK of EE before or after rifalazil administration. The posterior probabilities for the true treatment differences of Cmax or AUC(0-24) being less than 20% were > 99.99% in both cases. Based on the results of this study, there is no CYP3A4-metabolic interaction between a single oral, 25 mg dose of rifalazil and EE for either induction or inhibition. Consequently, there is minimal threat of contraceptive failure when single doses of rifalazil are administered with EE/NET. A single dose of rifalazil 25 mg was well tolerated when administered concomitantly with a combination oral contraceptive (EE/NET) by healthy postmenopausal females.
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Affiliation(s)
- Y-X Chen
- ActivBiotics, Inc., Lexington, MA, USA.
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Abstract
Rifalazil is a new antibiotic structurally related to rifampin but devoid of the metabolic liabilities typically associated with the rifamycin class of antibiotics. A randomized, 3-way crossover study in healthy male volunteers (n = 12) investigated the safety and pharmacokinetics of a single 25-mg oral rifalazil dose administered under a standard breakfast containing fat as 30% of calories, a high-fat breakfast containing fat as 60% of calories, and an overnight fast of 10 hours with a 21- to 28-day washout between doses. Systemic exposure to rifalazil based on Cmax, AUC(0-Tlast), and AUC(0-infinity) was increased progressively as the fat content of the test breakfast was increased from 30% to 60% compared with fasting. The confidence intervals for both fat-containing breakfasts are outside the limits of 80% to 125% allowed for food effect bioequivalence based on Cmax, AUC(0-Tlast), and AUC(0-infinity). This food effect may be a result of increased fractional absorption with increasing dietary fat content. Another striking finding was the large reduction of the pharmacokinetic intersubject variability after rifalazil administration with food. Rifalazil was safe and well tolerated under fed and fasted conditions.
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Affiliation(s)
- Y-X Chen
- ActivBiotics, Inc, Lexington, MA,
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Affiliation(s)
- A. Michaelis
- Chemisches Institut der Universität Rostock, Rostock
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Affiliation(s)
- W. La Coste
- Chem. Laboratorium des Polytechnikums in Karlsruhe
| | - A. Michaelis
- Chem. Laboratorium des Polytechnikums in Karlsruhe
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Affiliation(s)
| | - G. Erdmann
- Chemisches Institut der Universität Rostock
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