TY - JOUR A1 - Laquai, René A1 - Schaupp, Thomas A1 - Griesche, Axel A1 - Müller, Bernd R. A1 - Kupsch, Andreas A1 - Hannemann, Andreas A1 - Kannengiesser, Thomas A1 - Bruno, Giovanni T1 - Quantitative analysis of hydrogen-assisted microcracking in duplex stainless steel through X-ray refraction 3D imaging JF - Advanced engineering materials N2 - While the problem of the identification of mechanisms of hydrogen-assisted damage has and is being thoroughly studied, the quantitative analysis of such damage still lacks suitable tools. In fact, while, for instance, electron microscopy yields excellent characterization, the quantitative analysis of damage requires at the same time large field-of-views and high spatial resolution. Synchrotron X-ray refraction techniques do possess both features. Herein, it is shown how synchrotron X-ray refraction computed tomography (SXRCT) can quantify damage induced by hydrogen embrittlement in a lean duplex steel, yielding results that overperform even those achievable by synchrotron X-ray absorption computed tomography. As already reported in the literature, but this time using a nondestructive technique, it is shown that the hydrogen charge does not penetrate to the center of tensile specimens. By the comparison between virgin and hydrogen-charged specimens, it is deduced that cracks in the specimen bulk are due to the rolling process rather than hydrogen-assisted. It is shown that (micro)cracks propagate from the surface of tensile specimens to the interior with increasing applied strain, and it is deduced that a significant crack propagation can only be observed short before rupture. KW - 2101 duplex stainless steel KW - computed tomography KW - fractography KW - hydrogen KW - embrittlement KW - microcracking KW - synchrotron radiation KW - X-ray refraction Y1 - 2022 U6 - https://doi.org/10.1002/adem.202101287 SN - 1527-2648 VL - 24 IS - 6 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Liebe, Thomas A1 - Dordevic, Milos A1 - Kaufmann, Jörn A1 - Avetisyan, Araks A1 - Skalej, Martin A1 - Müller, Notger Germar T1 - Investigation of the functional pathogenesis of mild cognitive impairment by localisation-based locus coeruleus resting-state fMRI JF - Human Brain Mapping N2 - Dementia as one of the most prevalent diseases urges for a better understanding of the central mechanisms responsible for clinical symptoms, and necessitates improvement of actual diagnostic capabilities. The brainstem nucleus locus coeruleus (LC) is a promising target for early diagnosis because of its early structural alterations and its relationship to the functional disturbances in the patients. In this study, we applied our improved method of localisation-based LC resting-state fMRI to investigate the differences in central sensory signal processing when comparing functional connectivity (fc) of a patient group with mild cognitive impairment (MCI, n = 28) and an age-matched healthy control group (n = 29). MCI and control participants could be differentiated in their Mini-Mental-State-Examination (MMSE) scores (p < .001) and LC intensity ratio (p = .010). In the fMRI, LC fc to anterior cingulate cortex (FDR p < .001) and left anterior insula (FDR p = .012) was elevated, and LC fc to right temporoparietal junction (rTPJ, FDR p = .012) and posterior cingulate cortex (PCC, FDR p = .021) was decreased in the patient group. Importantly, LC to rTPJ connectivity was also positively correlated to MMSE scores in MCI patients (p = .017). Furthermore, we found a hyperactivation of the left-insula salience network in the MCI patients. Our results and our proposed disease model shed new light on the functional pathogenesis of MCI by directing to attentional network disturbances, which could aid new therapeutic strategies and provide a marker for diagnosis and prediction of disease progression. KW - attention KW - locus coeruleus KW - mild cognitive impairment KW - resting-state fMRI Y1 - 2022 U6 - https://doi.org/10.1002/hbm.26039 SN - 1097-0193 VL - 43 SP - 5630 EP - 5642 PB - Wiley CY - New York, NY, USA ET - 18 ER - TY - GEN A1 - Liebe, Thomas A1 - Dordevic, Milos A1 - Kaufmann, Jörn A1 - Avetisyan, Araks A1 - Skalej, Martin A1 - Müller, Notger Germar T1 - Investigation of the functional pathogenesis of mild cognitive impairment by localisation-based locus coeruleus resting-state fMRI T2 - Zweitveröffentlichungen der Universität Potsdam : Gesundheitswissenschaftliche Reihe N2 - Dementia as one of the most prevalent diseases urges for a better understanding of the central mechanisms responsible for clinical symptoms, and necessitates improvement of actual diagnostic capabilities. The brainstem nucleus locus coeruleus (LC) is a promising target for early diagnosis because of its early structural alterations and its relationship to the functional disturbances in the patients. In this study, we applied our improved method of localisation-based LC resting-state fMRI to investigate the differences in central sensory signal processing when comparing functional connectivity (fc) of a patient group with mild cognitive impairment (MCI, n = 28) and an age-matched healthy control group (n = 29). MCI and control participants could be differentiated in their Mini-Mental-State-Examination (MMSE) scores (p < .001) and LC intensity ratio (p = .010). In the fMRI, LC fc to anterior cingulate cortex (FDR p < .001) and left anterior insula (FDR p = .012) was elevated, and LC fc to right temporoparietal junction (rTPJ, FDR p = .012) and posterior cingulate cortex (PCC, FDR p = .021) was decreased in the patient group. Importantly, LC to rTPJ connectivity was also positively correlated to MMSE scores in MCI patients (p = .017). Furthermore, we found a hyperactivation of the left-insula salience network in the MCI patients. Our results and our proposed disease model shed new light on the functional pathogenesis of MCI by directing to attentional network disturbances, which could aid new therapeutic strategies and provide a marker for diagnosis and prediction of disease progression. T3 - Zweitveröffentlichungen der Universität Potsdam : Gesundheitswissenschaftliche Reihe - 7 KW - attention KW - locus coeruleus KW - mild cognitive impairment KW - resting-state fMRI Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-581772 IS - 7 SP - 5630 EP - 5642 ER - TY - JOUR A1 - Lai, Huagui A1 - Luo, Jincheng A1 - Zwirner, Yannick A1 - Olthof, Selina A1 - Wieczorek, Alexander A1 - Ye, Fangyuan A1 - Jeangros, Quentin A1 - Yin, Xinxing A1 - Akhundova, Fatima A1 - Ma, Tianshu A1 - He, Rui A1 - Kothandaraman, Radha K. A1 - Chin, Xinyu A1 - Gilshtein, Evgeniia A1 - Muller, Andre A1 - Wang, Changlei A1 - Thiesbrummel, Jarla A1 - Siol, Sebastian A1 - Prieto, Jose Marquez A1 - Unold, Thomas A1 - Stolterfoht, Martin A1 - Chen, Cong A1 - Tiwari, Ayodhya N. A1 - Zhao, Dewei A1 - Fu, Fan T1 - High-performance flexible all-Perovskite tandem solar cells with reduced V-OC-deficit in wide-bandgap subcell JF - Advanced energy materials N2 - Among various types of perovskite-based tandem solar cells (TSCs), all-perovskite TSCs are of particular attractiveness for building- and vehicle-integrated photovoltaics, or space energy areas as they can be fabricated on flexible and lightweight substrates with a very high power-to-weight ratio. However, the efficiency of flexible all-perovskite tandems is lagging far behind their rigid counterparts primarily due to the challenges in developing efficient wide-bandgap (WBG) perovskite solar cells on the flexible substrates as well as their low open-circuit voltage (V-OC). Here, it is reported that the use of self-assembled monolayers as hole-selective contact effectively suppresses the interfacial recombination and allows the subsequent uniform growth of a 1.77 eV WBG perovskite with superior optoelectronic quality. In addition, a postdeposition treatment with 2-thiopheneethylammonium chloride is employed to further suppress the bulk and interfacial recombination, boosting the V-OC of the WBG top cell to 1.29 V. Based on this, the first proof-of-concept four-terminal all-perovskite flexible TSC with a power conversion efficiency of 22.6% is presented. When integrating into two-terminal flexible tandems, 23.8% flexible all-perovskite TSCs with a superior V-OC of 2.1 V is achieved, which is on par with the V-OC reported on the 28% all-perovskite tandems grown on the rigid substrate. KW - all-perovskite tandems KW - flexible tandem solar cells KW - perovskite KW - V OC-deficit KW - wide-bandgap Y1 - 2022 U6 - https://doi.org/10.1002/aenm.202202438 SN - 1614-6832 SN - 1614-6840 VL - 12 IS - 45 PB - Wiley-VCH CY - Weinheim ER - TY - GEN A1 - Herold, Fabian A1 - Theobald, Paula A1 - Gronwald, Thomas A1 - Rapp, Michael A. A1 - Müller, Notger Germar T1 - Going digital – a commentary on the terminology used at the intersection of physical activity and digital health T2 - Zweitveröffentlichungen der Universität Potsdam : Gesundheitswissenschaftliche Reihe N2 - In recent years digital technologies have become a major means for providing health-related services and this trend was strongly reinforced by the current Coronavirus disease 2019 (COVID-19) pandemic. As it is well-known that regular physical activity has positive effects on individual physical and mental health and thus is an important prerequisite for healthy aging, digital technologies are also increasingly used to promote unstructured and structured forms of physical activity. However, in the course of this development, several terms (e.g., Digital Health, Electronic Health, Mobile Health, Telehealth, Telemedicine, and Telerehabilitation) have been introduced to refer to the application of digital technologies to provide health-related services such as physical interventions. Unfortunately, the above-mentioned terms are often used in several different ways, but also relatively interchangeably. Given that ambiguous terminology is a major source of difficulty in scientific communication which can impede the progress of theoretical and empirical research, this article aims to make the reader aware of the subtle differences between the relevant terms which are applied at the intersection of physical activity and Digital Health and to provide state-of-art definitions for them. T3 - Zweitveröffentlichungen der Universität Potsdam : Gesundheitswissenschaftliche Reihe - 5 KW - Digital Health KW - Electronic Health KW - Mobile Health KW - Telehealth KW - Telemedicine KW - Physical activity KW - Physical training KW - Aging Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-581301 IS - 5 ER - TY - JOUR A1 - Herold, Fabian A1 - Theobald, Paula A1 - Gronwald, Thomas A1 - Rapp, Michael A. A1 - Müller, Notger Germar T1 - Going digital – a commentary on the terminology used at the intersection of physical activity and digital health JF - European review of aging and physical activity N2 - In recent years digital technologies have become a major means for providing health-related services and this trend was strongly reinforced by the current Coronavirus disease 2019 (COVID-19) pandemic. As it is well-known that regular physical activity has positive effects on individual physical and mental health and thus is an important prerequisite for healthy aging, digital technologies are also increasingly used to promote unstructured and structured forms of physical activity. However, in the course of this development, several terms (e.g., Digital Health, Electronic Health, Mobile Health, Telehealth, Telemedicine, and Telerehabilitation) have been introduced to refer to the application of digital technologies to provide health-related services such as physical interventions. Unfortunately, the above-mentioned terms are often used in several different ways, but also relatively interchangeably. Given that ambiguous terminology is a major source of difficulty in scientific communication which can impede the progress of theoretical and empirical research, this article aims to make the reader aware of the subtle differences between the relevant terms which are applied at the intersection of physical activity and Digital Health and to provide state-of-art definitions for them. KW - Digital Health KW - Electronic Health KW - Mobile Health KW - Telehealth KW - Telemedicine KW - Physical activity KW - Physical training KW - Aging Y1 - 2022 U6 - https://doi.org/10.1186/s11556-022-00296-y SN - 1861-6909 VL - 19 PB - Springer CY - Berlin ; Heidelberg ER -