@article{VahidpourAlghazaliAkcaetal.2022, author = {Vahidpour, Farnoosh and Alghazali, Yousef H. M. and Akca, Sevilay and Hommes, Gregor and Sch{\"o}ning, Michael Josef}, title = {An Enzyme-Based Interdigitated Electrode-Type Biosensor for Detecting Low Concentrations of H₂O₂ Vapor/Aerosol}, series = {Chemosensors}, volume = {10}, journal = {Chemosensors}, number = {6}, publisher = {MDPI}, address = {Basel}, issn = {2227-9040}, doi = {10.3390/chemosensors10060202}, pages = {Arikel 202}, year = {2022}, abstract = {This work introduces a novel method for the detection of H₂O₂ vapor/aerosol of low concentrations, which is mainly applied in the sterilization of equipment in medical industry. Interdigitated electrode (IDE) structures have been fabricated by means of microfabrication techniques. A differential setup of IDEs was prepared, containing an active sensor element (active IDE) and a passive sensor element (passive IDE), where the former was immobilized with an enzymatic membrane of horseradish peroxidase that is selective towards H₂O₂. Changes in the IDEs' capacitance values (active sensor element versus passive sensor element) under H₂O₂ vapor/aerosol atmosphere proved the detection in the concentration range up to 630 ppm with a fast response time (<60 s). The influence of relative humidity was also tested with regard to the sensor signal, showing no cross-sensitivity. The repeatability assessment of the IDE biosensors confirmed their stable capacitive signal in eight subsequent cycles of exposure to H₂O₂ vapor/aerosol. Room-temperature detection of H₂O₂ vapor/aerosol with such miniaturized biosensors will allow a future three-dimensional, flexible mapping of aseptic chambers and help to evaluate sterilization assurance in medical industry.}, language = {en} } @article{BaumannTillmannAletsee1989, author = {Baumann, Marcus and Tillmann, Urban and Aletsee, Ludwig}, title = {Distribution of Carbon Among Photosynthetic End Products in the Bloom-Forming Arctic Diatom Thalassiosira antarctica COMBER / Tillmann, U. ; Baumann, M.E.M. ; Aletsee, L.}, series = {Polar Biology. 10 (1989), H. 3}, journal = {Polar Biology. 10 (1989), H. 3}, isbn = {0722-4060}, pages = {231 -- 238}, year = {1989}, language = {en} } @article{BialonskiAllefeldWellmeretal.2008, author = {Bialonski, Stephan and Allefeld, Carsten and Wellmer, J{\"o}rg and Elger, Christian E. and Lehnertz, Klaus}, title = {An approach to identify synchronization clusters within the epileptic network}, series = {Klinische Neurophysiologie}, volume = {39}, journal = {Klinische Neurophysiologie}, number = {1}, doi = {10.1055/s-2008-1072881}, pages = {A79}, year = {2008}, language = {en} } @article{GrinsvenVandenBonGrietenetal.2011, author = {Grinsven, Bart van and Vanden Bon, Natalie and Grieten, Lars and Murib, Mohammed Sharif and Janssen, Stoffel Dominique and Haenen, Ken and Schneider, E. and Ingebrandt, Sven and Sch{\"o}ning, Michael Josef and Vermeeren, Veronique and Ameloot, Marcel and Michiels, Luc and Thoelen, Ronald and De Ceuninck, Ward A. and Wagner, Patrick}, title = {Rapid assessment of the stability of DNA duplexes by impedimetric real-time monitoring of chemically induced denaturation}, series = {Lab on a Chip}, volume = {11}, journal = {Lab on a Chip}, number = {9}, publisher = {Royal Society of Chemistry (RSC)}, address = {Cambridge}, isbn = {1473-0197}, pages = {1656 -- 1663}, year = {2011}, language = {en} } @article{MuribGrinsvenGrietenetal.2013, author = {Murib, M. S. and Grinsven, B. van and Grieten, L. and Janssens, S. D. and Vermeeren, V. and Eersels, K. and Broeders, J. and Ameloot, Marcel and Michiels, L. and Ceuninck, W. De and Haenen, K. and Sch{\"o}ning, Michael Josef and Wagner, Patrick}, title = {Electronic monitoring of chemical DNA denaturation on nanocrystalline diamond electrodes with different molarities and flow rates}, series = {Physica Status Solidi (A). Vol. 210 (2013), iss. 5}, journal = {Physica Status Solidi (A). Vol. 210 (2013), iss. 5}, publisher = {Wiley-VCH}, address = {Berlin}, issn = {0031-8965}, pages = {911 -- 917}, year = {2013}, language = {en} } @article{MuribYeapEurlingsetal.2016, author = {Murib, M. S. and Yeap, W. S. and Eurlings, Y. and Grinsven, B. van and Boyen, H.-G. and Conings, B. and Michiels, L. and Ameloot, Marcel and Carleer, R. and Warmer, J. and Kaul, P. and Haenen, K. and Sch{\"o}ning, Michael Josef and Ceuninck, W. de and Wagner, P.}, title = {Heat-transfer based characterization of DNA on synthetic sapphire chips}, series = {Sensors and Actuators B: Chemical}, volume = {230}, journal = {Sensors and Actuators B: Chemical}, number = {230}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0925-4005}, doi = {10.1016/j.snb.2016.02.027}, pages = {260 -- 271}, year = {2016}, abstract = {In this study, we show that synthetic sapphire (Al₂O₃), an established implant material, can also serve as a platform material for biosensors comparable to nanocrystalline diamond. Sapphire chips, beads, and powder were first modified with (3-aminopropyl) triethoxysilane (APTES), followed by succinic anhydride (SA), and finally single-stranded probe DNA was EDC coupled to the functionalized layer. The presence of the APTES-SA layer on sapphire powders was confirmed by thermogravimetric analyis and Fourier-transform infrared spectroscopy. Using planar sapphire chips as substrates and X-ray photoelectron spectroscopy (XPS) as surface-sensitive tool, the sequence of individual layers was analyzed with respect to their chemical state, enabling the quantification of areal densities of the involved molecular units. Fluorescence microscopy was used to demonstrate the hybridization of fluorescently tagged target DNA to the probe DNA, including denaturation- and re-hybridization experiments. Due to its high thermal conductivity, synthetic sapphire is especially suitable as a chip material for the heat-transfer method, which was employed to distinguish complementary- and non-complementary DNA duplexes containing single-nucleotide polymorphisms. These results indicate that it is possible to detect mutations electronically with a chemically resilient and electrically insulating chip material.}, language = {en} } @article{BiewendtBlaschkeBoehnert2020, author = {Biewendt, Marcel and Blaschke, Florian and B{\"o}hnert, Arno}, title = {An evaluation of corporate sustainability in context of the Jevons paradox}, series = {SocioEconomic Challenges}, volume = {4}, journal = {SocioEconomic Challenges}, number = {3}, publisher = {ARMG Publishing}, address = {Sumy}, issn = {2520-6214}, doi = {10.21272/sec.4(3).46-65.2020}, pages = {46 -- 65}, year = {2020}, abstract = {The successful implementation and continuous development of sustainable corporate-level solutions is a challenge. These are endeavours in which social, environmental, and financial aspects must be weighed against each other. They can prove difficult to handle and, in some cases, almost unrealistic. Concepts such as green controlling, IT, and manufacturing look promising and are constantly evolving. This paper aims to achieve a better understanding of the field of corporate sustainability (CS). It will evaluate the hypothesis by which Corporate Sustainability thrives, via being efficient, increasing the performance, and raising the value of the input of the enterprises to the resources used. In fact, Corporate Sustainability on the surface could seem to contradict the idea, which supports the understanding that it encourages the reduction of the heavy reliance on the use of natural resources, the overall environmental impact, and above all, their protection. To understand how the contradictory notion of CS came about, in this part of the paper, the emphasis is placed on providing useful insight to this regard. The first part of this paper summarizes various definitions, organizational theories, and measures used for CS and its derivatives like green controlling, IT, and manufacturing. Second, a case study is given that combines the aforementioned sustainability models. In addition to evaluating the hypothesis, the overarching objective of this paper is to demonstrate the use of green controlling, IT, and manufacturing in the corporate sector. Furthermore, this paper outlines the current challenges and possible directions for CS in the future.}, language = {en} } @article{BiewendtBoehnertBlaschke2020, author = {Biewendt, Marcel and B{\"o}hnert, Arno and Blaschke, Florian}, title = {The repercussions of the digital twin in the automotive industry on the new marketing logic}, series = {European Journal of Marketing and Economics}, volume = {4}, journal = {European Journal of Marketing and Economics}, number = {1}, publisher = {Revistia}, address = {London}, issn = {2601-8659}, doi = {10.26417/229eim64f}, pages = {68 -- 73}, year = {2020}, abstract = {Rapid development of virtual and data acquisition technology makes Digital Twin Technology (DT) one of the fundamental areas of research, while DT is one of the most promissory developments for the achievement of Industry 4.0. 48\% percent of organisations implementing the Internet of Things are already using DT or plan to use DT in 2020. The global market for DT is expected to grow by 38 percent annually, reaching USD16 billion by 2023. In addition, the number of participating organisations using digital twins is expected to triple by 2022. DTs are characterised by the integration between physical and virtual spaces. The driving idea for DT is to develop, test and build our devices in a virtual environment. The objective of this paper is to study the impact of DT in the automotive industry on the new marketing logic. This paper outlines the current challenges and possible directions for the future DT in marketing. This paper will be helpful for managers in the industry to use the advantages and potentials of DT.}, language = {en} } @article{KohlKraemerFohryetal.2024, author = {Kohl, Philipp and Kr{\"a}mer, Yoka and Fohry, Claudia and Kraft, Bodo}, title = {Scoping review of active learning strategies and their evaluation environments for entity recognition tasks}, series = {Deep learning theory and applications}, journal = {Deep learning theory and applications}, editor = {Fred, Ana and Hadjali, Allel and Gusikhin, Oleg and Sansone, Carlo}, publisher = {Springer}, address = {Cham}, isbn = {978-3-031-66694-0 (online ISBN)}, doi = {10.1007/978-3-031-66694-0_6}, pages = {84 -- 106}, year = {2024}, abstract = {We conducted a scoping review for active learning in the domain of natural language processing (NLP), which we summarize in accordance with the PRISMA-ScR guidelines as follows: Objective: Identify active learning strategies that were proposed for entity recognition and their evaluation environments (datasets, metrics, hardware, execution time). Design: We used Scopus and ACM as our search engines. We compared the results with two literature surveys to assess the search quality. We included peer-reviewed English publications introducing or comparing active learning strategies for entity recognition. Results: We analyzed 62 relevant papers and identified 106 active learning strategies. We grouped them into three categories: exploitation-based (60x), exploration-based (14x), and hybrid strategies (32x). We found that all studies used the F1-score as an evaluation metric. Information about hardware (6x) and execution time (13x) was only occasionally included. The 62 papers used 57 different datasets to evaluate their respective strategies. Most datasets contained newspaper articles or biomedical/medical data. Our analysis revealed that 26 out of 57 datasets are publicly accessible. Conclusion: Numerous active learning strategies have been identified, along with significant open questions that still need to be addressed. Researchers and practitioners face difficulties when making data-driven decisions about which active learning strategy to adopt. Conducting comprehensive empirical comparisons using the evaluation environment proposed in this study could help establish best practices in the domain.}, language = {en} } @article{RaffeisAdjeiKyeremehVroomenetal.2020, author = {Raffeis, Iris and Adjei-Kyeremeh, Frank and Vroomen, Uwe and Westhoff, Elmar and Bremen, Sebastian and Hohoi, Alexandru and B{\"u}hrig-Polaczek, Andreas}, title = {Qualification of a Ni-Cu alloy for the laser powder bed fusion process (LPBF): Its microstructure and mechanical properties}, series = {Applied Sciences}, volume = {10}, journal = {Applied Sciences}, number = {Art. 3401}, publisher = {MDPI}, address = {Basel}, issn = {2076-3417}, doi = {10.3390/app10103401}, pages = {1 -- 15}, year = {2020}, abstract = {As researchers continue to seek the expansion of the material base for additive manufacturing, there is a need to focus attention on the Ni-Cu group of alloys which conventionally has wide industrial applications. In this work, the G-NiCu30Nb casting alloy, a variant of the Monel family of alloys with Nb and high Si content is, for the first time, processed via the laser powder bed fusion process (LPBF). Being novel to the LPBF processes, optimum LPBF parameters were determined, and hardness and tensile tests were performed in as-built conditions and after heat treatment at 1000 °C. Microstructures of the as-cast and the as-built condition were compared. Highly dense samples (99.8\% density) were achieved after varying hatch distance (80 µm and 140 µm) with scanning speed (550 mm/s-1500 mm/s). There was no significant difference in microhardness between varied hatch distance print sets. Microhardness of the as-built condition (247 HV0.2) exceeded the as-cast microhardness (179 HV0.2.). Tensile specimens built in vertical (V) and horizontal (H) orientations revealed degrees of anisotropy and were superior to conventionally reported figures. Post heat treatment increased ductility from 20\% to 31\% (V), as well as from 16\% to 25\% (H), while ultimate tensile strength (UTS) and yield strength (YS) were considerably reduced.}, language = {en} } @article{Biewendt2020, author = {Biewendt, Marcel}, title = {Sustainable development: A quantitative analysis regarding the impact of resource rents on state welfare from 2002 to 2017}, series = {SocioEconomic Challenges}, volume = {4}, journal = {SocioEconomic Challenges}, number = {4}, publisher = {ARMG Publishing}, address = {Sumy}, issn = {2520-6214}, doi = {10.21272/sec.4(4).119-131.2020}, pages = {119 -- 131}, year = {2020}, abstract = {This paper uses a quantitative analysis to examine the interdependence and impact of resource rents on socio-economic development from 2002 to 2017. Nigeria and Norway have been chosen as reference countries due to their abundance of natural resources by similar economic performance, while the ranking in the Human Development Index differs dramatically. As the Human Development Index provides insight into a country's cultural and socio-economic characteristics and development in addition to economic indicators, it allows a comparison of the two countries. The hypothesis presented and discussed in this paper was researched before. A qualitative research approach was used in the author's master's thesis "The Human Development Index (HDI) as a Reflection of Resource Abundance (using Nigeria and Norway as a case study)" in 2018. The management of scarce resources is an important aspect in the development of modern countries and those on the threshold of becoming industrialised nations. The effects of a mistaken resource management are not only of a purely economic nature but also of a social and socio-economic nature. In order to present a partial aspect of these dependencies and influences this paper uses a quantitative analysis to examine the interdependence and impact of resource rents on socio-economic development from 2002 to 2017. Nigeria and Norway have been chosen as reference countries due to their abundance of natural resources by similar economic performance, while the ranking in the Human Development Index differs significantly. As the Human Development Index provides insight into a country's cultural and socio-economic characteristics and development in addition to economic indicators, it allows a comparison of the two countries. This paper found out in a holistic perspective that (not or poorly managed) resource wealth in itself has a negative impact on socio-economic development and significantly reduces the productivity of the citizens of a state. This is expressed in particular for the years 2002 till 2017 in a negative correlation of GDP per capita and HDI value with the share respectively the size of resources in the GDP of a country.}, language = {en} } @article{BoehnertBlaschkeBiewendt2023, author = {B{\"o}hnert, Arno and Blaschke, Florian and Biewendt, Marcel}, title = {Impact of sustainability on the strategic direction of luxury companies}, series = {European Journal of Marketing and Economics}, volume = {6}, journal = {European Journal of Marketing and Economics}, number = {1}, publisher = {Revistia}, address = {London}, issn = {2601-8659}, pages = {70 -- 85}, year = {2023}, abstract = {Today's society is undergoing a paradigm shift driven by the megatrend of sustainability. This undeniably affects all areas of Western life. This paper aims to find out how the luxury industry is dealing with this change and what adjustments are made by the companies. For this purpose, interviews were conducted with managers from the luxury industry, in which they were asked about specific measures taken by their companies as well as trends in the industry. In a subsequent evaluation, the trends in the luxury industry were summarized for the areas of ecological, social, and economic sustainability. It was found that the area of environmental sustainability is significantly more focused than the other sub-areas. Furthermore, the need for a customer survey to validate the industry-based measures was identified.}, language = {en} } @article{StapenhorstZabekHildebrand2018, author = {Stapenhorst, Carolin and Zabek, Magdalena and Hildebrand, Linda}, title = {Communication process and information flow in the architectural planning context}, series = {Creativity game : theory and practice of spatial planning}, journal = {Creativity game : theory and practice of spatial planning}, number = {6}, publisher = {University of Ljubljana}, address = {Ljubljana}, doi = {10.15292/IU-CG.2018.06.066-073}, pages = {66 -- 73}, year = {2018}, abstract = {Against the background of growing data in everyday life, data processing tools become more powerful to deal with the increasing complexity in building design. The architectural planning process is offered a variety of new instruments to design, plan and communicate planning decisions. Ideally the access to information serves to secure and document the quality of the building and in the worst case, the increased data absorbs time by collection and processing without any benefit for the building and its user. Process models can illustrate the impact of information on the design- and planning process so that architect and planner can steer the process. This paper provides historic and contemporary models to visualize the architectural planning process and introduces means to describe today's situation consisting of stakeholders, events and instruments. It explains conceptions during Renaissance in contrast to models used in the second half of the 20th century. Contemporary models are discussed regarding their value against the background of increasing computation in the building process.}, language = {en} } @article{StapenhorstDutto2016, author = {Stapenhorst, Carolin and Dutto, Andrea Alberto}, title = {Notes on conceptual learning in architecture}, series = {Cartha - The Form of Form}, journal = {Cartha - The Form of Form}, address = {Basel}, year = {2016}, language = {en} } @article{RakeEnningKurthetal.1994, author = {Rake, Heinrich and Enning, Manfred and Kurth, Johannes and Schr{\"o}der, Walter}, title = {Automatic uncoupler completes automation at the hump}, series = {RGI - Railway Gazette International}, volume = {150}, journal = {RGI - Railway Gazette International}, number = {6}, publisher = {Reed Business}, address = {Sutton}, issn = {0373-5346}, pages = {371 -- 374}, year = {1994}, language = {en} } @article{HafidiElHatkaSchmitzetal.2024, author = {Hafidi, Youssef and El Hatka, Hicham and Schmitz, Dominik and Krauss, Manuel and Pettrak, J{\"u}rgen and Biel, Markus and Ittobane, Najim}, title = {Sustainable soil additives for water and micronutrient supply: swelling and chelating properties of polyaspartic acid hydrogels utilizing newly developed crosslinkers}, series = {Gels}, volume = {10}, journal = {Gels}, number = {3}, publisher = {MDPI}, address = {Basel}, issn = {2310-2861}, doi = {10.3390/gels10030170}, pages = {Artikel 170}, year = {2024}, abstract = {Drought and water shortage are serious problems in many arid and semi-arid regions. This problem is getting worse and even continues in temperate climatic regions due to climate change. To address this problem, the use of biodegradable hydrogels is increasingly important for the application as water-retaining additives in soil. Furthermore, efficient (micro-)nutrient supply can be provided by the use of tailored hydrogels. Biodegradable polyaspartic acid (PASP) hydrogels with different available (1,6-hexamethylene diamine (HMD) and L-lysine (LYS)) and newly developed crosslinkers based on diesters of glycine (GLY) and (di-)ethylene glycol (DEG and EG, respectively) were synthesized and characterized using Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM) and regarding their swelling properties (kinetic, absorbency under load (AUL)) as well as biodegradability of PASP hydrogel. Copper (II) and zinc (II), respectively, were loaded as micronutrients in two different approaches: in situ with crosslinking and subsequent loading of prepared hydrogels. The results showed successful syntheses of di-glycine-ester-based crosslinkers. Hydrogels with good water-absorbing properties were formed. Moreover, the developed crosslinking agents in combination with the specific reaction conditions resulted in higher water absorbency with increased crosslinker content used in synthesis (10\% vs. 20\%). The prepared hydrogels are candidates for water-storing soil additives due to the biodegradability of PASP, which is shown in an exemple. The incorporation of Cu(II) and Zn(II) ions can provide these micronutrients for plant growth.}, language = {en} } @article{AsarStapenhorst2020, author = {Asar, Hande and Stapenhorst, Carolin}, title = {Zvi Hecker: Drawing on drawing}, series = {Archives of Design Research}, volume = {33}, journal = {Archives of Design Research}, number = {3}, publisher = {Korean Society of Design Science}, address = {Seongnam}, issn = {1226-8046}, doi = {10.15187/adr.2020.08.33.3.45}, pages = {45 -- 53}, year = {2020}, abstract = {Background: Architectural representation, nurtured by the interaction between design thinking and design action, is inherently multi-layered. However, the representation object cannot always reflect these layers. Therefore, it is claimed that these reflections and layerings can gain visibility through 'performativity in personal knowledge', which basically has a performative character. The specific layers of representation produced during the performativity in personal knowledge permit insights about the 'personal way of designing' [1]. Therefore, the question, 'how can these layered drawings be decomposed to understand the personal way of designing', can be defined as the beginning of the study. On the other hand, performativity in personal knowledge in architectural design is handled through the relationship between explicit and tacit knowledge and representational and non-representational theory. To discuss the practical dimension of these theoretical relations, Zvi Hecker's drawing of the Heinz-Galinski-School is examined as an example. The study aims to understand the relationships between the layers by decomposing a layered drawing analytically in order to exemplify personal ways of designing. Methods: The study is based on qualitative research methodologies. First, a model has been formed through theoretical readings to discuss the performativity in personal knowledge. This model is used to understand the layered representations and to research the personal way of designing. Thus, one drawing of Hecker's Heinz-Galinski-School project is chosen. Second, its layers are decomposed to detect and analyze diverse objects, which hint to different types of design tools and their application. Third, Zvi Hecker's statements of the design process are explained through the interview data [2] and other sources. The obtained data are compared with each other. Results: By decomposing the drawing, eleven layers are defined. These layers are used to understand the relation between the design idea and its representation. They can also be thought of as a reading system. In other words, a method to discuss Hecker's performativity in personal knowledge is developed. Furthermore, the layers and their interconnections are described in relation to Zvi Hecker's personal way of designing. Conclusions: It can be said that layered representations, which are associated with the multilayered structure of performativity in personal knowledge, form the personal way of designing.}, language = {en} } @article{RieplPettrakFaulstichetal.2010, author = {Riepl, Herbert Matthias and Pettrak, J{\"u}rgen and Faulstich, Martin and Herrmann, Wolfgang Anton}, title = {Self metathesis of fatty alcohols and amines to provide monomers for polyester and polyamide products}, series = {Macromolecular Symposia}, volume = {293}, journal = {Macromolecular Symposia}, number = {1}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1521-3900 (eISSN)}, doi = {10.1002/masy.200900041}, pages = {39 -- 42}, year = {2010}, abstract = {Self metathesis of oleochemicals offers a variety of bifunctional compounds, that can be used as monomer for polymer production. Many precursors are in huge scales available, like oleic acid ester (biodiesel), oleyl alcohol (tensides), oleyl amines (tensides, lubricants). We show several ways to produce and separate and purify C18-α,ω-bifunctional compounds, using Grubbs 2nd Generation catalysts, starting from technical grade educts.}, language = {en} } @article{UysalFiratCreutzetal.2022, author = {Uysal, Karya and Firat, Ipek Serat and Creutz, Till and Aydin, Inci Cansu and Artmann, Gerhard and Teusch, Nicole and Temiz Artmann, Ayseg{\"u}l}, title = {A novel in vitro wound healing assay using free-standing, ultra-thin PDMS membranes}, series = {membranes}, volume = {2023}, journal = {membranes}, number = {13(1)}, publisher = {MDPI}, address = {Basel}, doi = {10.3390/membranes13010022}, pages = {Artikel 22}, year = {2022}, abstract = {Advances in polymer science have significantly increased polymer applications in life sciences. We report the use of free-standing, ultra-thin polydimethylsiloxane (PDMS) membranes, called CellDrum, as cell culture substrates for an in vitro wound model. Dermal fibroblast monolayers from 28- and 88-year-old donors were cultured on CellDrums. By using stainless steel balls, circular cell-free areas were created in the cell layer (wounding). Sinusoidal strain of 1 Hz, 5\% strain, was applied to membranes for 30 min in 4 sessions. The gap circumference and closure rate of un-stretched samples (controls) and stretched samples were monitored over 4 days to investigate the effects of donor age and mechanical strain on wound closure. A significant decrease in gap circumference and an increase in gap closure rate were observed in trained samples from younger donors and control samples from older donors. In contrast, a significant decrease in gap closure rate and an increase in wound circumference were observed in the trained samples from older donors. Through these results, we propose the model of a cell monolayer on stretchable CellDrums as a practical tool for wound healing research. The combination of biomechanical cell loading in conjunction with analyses such as gene/protein expression seems promising beyond the scope published here.}, language = {en} } @article{OrzadaSolbachGratzetal.2019, author = {Orzada, Stephan and Solbach, Klaus and Gratz, Marcel and Brunheim, Sascha and Fiedler, Thomas M. and Johst, S{\"o}ren and Bitz, Andreas and Shooshtary, Samaneh and Abuelhaija, Ashraf and Voelker, Maximilian N. and Rietsch, Stefan H. G. and Kraff, Oliver and Maderwald, Stefan and Fl{\"o}ser, Martina and Oehmingen, Mark and Quick, Harald H. and Ladd, Mark E.}, title = {A 32-channel parallel transmit system add-on for 7T MRI}, series = {Plos one}, journal = {Plos one}, doi = {10.1371/journal.pone.0222452}, year = {2019}, language = {en} } @article{OrzadaBitzJohstetal.2017, author = {Orzada, Stephan and Bitz, Andreas and Johst, S{\"o}ren and Gratz, Marcel and V{\"o}lker, Maximilian N. and Kraff, Oliver and Abuelhaija, Ashraf and Fiedler, Thomas M. and Solbach, Klaus and Quick, Harald H. and Ladd, Mark E.}, title = {Analysis of an integrated 8-Channel Tx/Rx body array for use as a body coil in 7-Tesla MRI}, series = {Frontiers in Physics}, volume = {5}, journal = {Frontiers in Physics}, number = {Jun}, issn = {2296-424X}, doi = {10.3389/fphy.2017.00017}, year = {2017}, language = {en} } @article{SchollPalmLehmannetal.1998, author = {Scholl, Ingrid and Palm, Christoph and Lehmann, Thomas Martin and Spitzer, Klaus}, title = {Quantitative Farbmessung in laryngoskopischen Bildern. Palm, C; Scholl, I; Lehmann, TM; Spitzer, K.}, series = {Bildverarbeitung f{\"u}r die Medizin 1998. Hrsg.: Thomas Lehmann ...}, journal = {Bildverarbeitung f{\"u}r die Medizin 1998. Hrsg.: Thomas Lehmann ...}, publisher = {Springer}, address = {Berlin}, isbn = {3-540-63885-7}, pages = {412 -- 416}, year = {1998}, language = {en} } @article{FiedlerLaddBitz2017, author = {Fiedler, Thomas M. and Ladd, Mark E. and Bitz, Andreas}, title = {RF safety assessment of a bilateral four-channel transmit/receive 7 Tesla breast coil: SAR versus temperature limits}, series = {Medical Physics}, volume = {44}, journal = {Medical Physics}, number = {1}, doi = {10.1002/mp.12034}, pages = {143 -- 157}, year = {2017}, language = {en} } @article{DieringerRenzLindeletal.2011, author = {Dieringer, Matthias A. and Renz, Wolfgang and Lindel, Tomasz Dawid and Seifert, Frank and Frauenrath, Tobias and von Knobelsdorf-Brenkenhoff, Florian and Waiczies, Helmar and Hoffmann, Werner and Rieger, Jan and Pfeiffer, Harald and Ittermann, Bernd and Schulz-Menger, Jeanette and Niendorf, Thoralf}, title = {Design and application of a four-channel transmit/receive surface coil for functional cardiac imaging at 7T}, series = {Journal of Magnetic Resonance Imaging}, volume = {33}, journal = {Journal of Magnetic Resonance Imaging}, number = {3}, publisher = {Wiley-Liss}, address = {New York}, issn = {1522-2586}, doi = {10.1002/jmri.22451}, pages = {736 -- 741}, year = {2011}, abstract = {Purpose To design and evaluate a four-channel cardiac transceiver coil array for functional cardiac imaging at 7T. Materials and Methods A four-element cardiac transceiver surface coil array was developed with two rectangular loops mounted on an anterior former and two rectangular loops on a posterior former. specific absorption rate (SAR) simulations were performed and a Burn:x-wiley:10531807:media:JMRI22451:tex2gif-stack-1 calibration method was applied prior to obtain 2D FLASH CINE (mSENSE, R = 2) images from nine healthy volunteers with a spatial resolution of up to 1 × 1 × 2.5 mm3. Results Tuning and matching was found to be better than 10 dB for all subjects. The decoupling (S21) was measured to be >18 dB between neighboring loops, >20 dB for opposite loops, and >30 dB for other loop combinations. SAR values were well within the limits provided by the IEC. Imaging provided clinically acceptable signal homogeneity with an excellent blood-myocardium contrast applying the Burn:x-wiley:10531807:media:JMRI22451:tex2gif-stack-2 calibration approach. Conclusion A four-channel cardiac transceiver coil array for 7T was built, allowing for cardiac imaging with clinically acceptable signal homogeneity and an excellent blood-myocardium contrast. Minor anatomic structures, such as pericardium, mitral, and tricuspid valves and their apparatus, as well as trabeculae, were accurately delineated.}, language = {en} } @article{FiedlerLaddClemensetal.2020, author = {Fiedler, Thomas M. and Ladd, Mark E. and Clemens, Markus and Bitz, Andreas}, title = {Safety of subjects during radiofrequency exposure in ultra-high-field magnetic resonance imaging}, series = {IEEE Letters on Electromagnetic Compatibility Practice and Applications}, volume = {2}, journal = {IEEE Letters on Electromagnetic Compatibility Practice and Applications}, number = {3}, publisher = {IEEE}, address = {New York, NY}, isbn = {2637-6423}, doi = {10.1109/LEMCPA.2020.3029747}, pages = {1 -- 8}, year = {2020}, abstract = {Magnetic resonance imaging (MRI) is one of the most important medical imaging techniques. Since the introduction of MRI in the mid-1980s, there has been a continuous trend toward higher static magnetic fields to obtain i.a. a higher signal-to-noise ratio. The step toward ultra-high-field (UHF) MRI at 7 Tesla and higher, however, creates several challenges regarding the homogeneity of the spin excitation RF transmit field and the RF exposure of the subject. In UHF MRI systems, the wavelength of the RF field is in the range of the diameter of the human body, which can result in inhomogeneous spin excitation and local SAR hotspots. To optimize the homogeneity in a region of interest, UHF MRI systems use parallel transmit systems with multiple transmit antennas and time-dependent modulation of the RF signal in the individual transmit channels. Furthermore, SAR increases with increasing field strength, while the SAR limits remain unchanged. Two different approaches to generate the RF transmit field in UHF systems using antenna arrays close and remote to the body are investigated in this letter. Achievable imaging performance is evaluated compared to typical clinical RF transmit systems at lower field strength. The evaluation has been performed under consideration of RF exposure based on local SAR and tissue temperature. Furthermore, results for thermal dose as an alternative RF exposure metric are presented.}, language = {en} } @article{BlomeMashhoon1984, author = {Blome, Hans-Joachim and Mashhoon, Bahram}, title = {Quasi-normal oscillations of a Schwarzschild black hole}, series = {Physics Letters A. 100 (1984), H. 5}, journal = {Physics Letters A. 100 (1984), H. 5}, isbn = {0375-9601}, pages = {231 -- 234}, year = {1984}, language = {en} } @article{HoehrPaulssenBenardetal.2014, author = {Hoehr, Cornelia and Paulßen, Elisabeth and Benard, Francois and Lee, Chris Jaeil and Hou, Xinchi and Badesso, Brian and Ferguson, Simon and Miao, Qing and Yang, Hua and Buckley, Ken and Hanemaayer, Victoire and Zeisler, Stefan and Ruth, Thomas J. and Celler, Anna and Schaffer, Paul}, title = {⁴⁴ᶢSc production using a water target on a 13 MeV cyclotron}, series = {Nuclear medicine and biology}, volume = {41}, journal = {Nuclear medicine and biology}, number = {5}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1872-9614}, doi = {10.1016/j.nucmedbio.2013.12.016}, pages = {401 -- 406}, year = {2014}, abstract = {Access to promising radiometals as isotopes for novel molecular imaging agents requires that they are routinely available and inexpensive to obtain. Proximity to a cyclotron center outfitted with solid target hardware, or to an isotope generator for the metal of interest is necessary, both of which can introduce significant hurdles in development of less common isotopes. Herein, we describe the production of ⁴⁴Sc (t₁⸝₂ = 3.97 h, Eavg,β⁺ = 1.47 MeV, branching ratio = 94.27\%) in a solution target and an automated loading system which allows a quick turn-around between different radiometallic isotopes and therefore greatly improves their availability for tracer development. Experimental yields are compared to theoretical calculations.}, language = {en} } @article{FiedlerLaddBitz2017, author = {Fiedler, Thomas M. and Ladd, Mark E. and Bitz, Andreas}, title = {SAR Simulations \& Safety}, series = {NeuroImage}, journal = {NeuroImage}, number = {Epub ahead of print}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1053-8119}, doi = {10.1016/j.neuroimage.2017.03.035}, year = {2017}, language = {en} } @article{OrzadaFiedlerBitzetal.2020, author = {Orzada, Stephan and Fiedler, Thomas M. and Bitz, Andreas and Ladd, Mark E. and Quick, Harald H.}, title = {Local SAR compression with overestimation control to reduce maximum relative SAR overestimation and improve multi-channel RF array performance}, series = {Magnetic Resonance Materials in Physics, Biology and Medicine}, journal = {Magnetic Resonance Materials in Physics, Biology and Medicine}, number = {34 (2021)}, publisher = {Springer}, address = {Heidelberg}, isbn = {1352-8661}, doi = {10.1007/s10334-020-00890-0}, pages = {153 -- 164}, year = {2020}, abstract = {Objective In local SAR compression algorithms, the overestimation is generally not linearly dependent on actual local SAR. This can lead to large relative overestimation at low actual SAR values, unnecessarily constraining transmit array performance. Method Two strategies are proposed to reduce maximum relative overestimation for a given number of VOPs. The first strategy uses an overestimation matrix that roughly approximates actual local SAR; the second strategy uses a small set of pre-calculated VOPs as the overestimation term for the compression. Result Comparison with a previous method shows that for a given maximum relative overestimation the number of VOPs can be reduced by around 20\% at the cost of a higher absolute overestimation at high actual local SAR values. Conclusion The proposed strategies outperform a previously published strategy and can improve the SAR compression where maximum relative overestimation constrains the performance of parallel transmission.}, language = {en} } @article{GraesslRenzHezeletal.2013, author = {Gr{\"a}ßl, Andreas and Renz, Wolfgang and Hezel, Fabian and Dieringer, Matthias A. and Winter, Lukas and {\"O}zerdem, Celal and Rieger, Jan and Kellmann, Peter and Santoro, Davide and Lindel, Tomasz Dawid and Frauenrath, Tobias and Pfeiffer, Harald and Niendorf, Thoralf}, title = {Modular 32-channel transceiver coil array for cardiac MRI at 7.0T}, series = {Magnetic Resonance in Medicine}, volume = {72}, journal = {Magnetic Resonance in Medicine}, number = {1}, publisher = {Wiley-Liss}, address = {New York}, issn = {1522-2594}, doi = {10.1002/mrm.24903}, pages = {276 -- 290}, year = {2013}, abstract = {Purpose To design and evaluate a modular transceiver coil array with 32 independent channels for cardiac MRI at 7.0T. Methods The modular coil array comprises eight independent building blocks, each containing four transceiver loop elements. Numerical simulations were used for B1+ field homogenization and radiofrequency (RF) safety validation. RF characteristics were examined in a phantom study. The array's suitability for accelerated high spatial resolution two-dimensional (2D) FLASH CINE imaging of the heart was examined in a volunteer study. Results Transmission field adjustments and RF characteristics were found to be suitable for the volunteer study. The signal-to-noise intrinsic to 7.0T together with the coil performance afforded a spatial resolution of 1.1 × 1.1 × 2.5 mm3 for 2D CINE FLASH MRI, which is by a factor of 6 superior to standardized CINE protocols used in clinical practice at 1.5T. The 32-channel transceiver array supports one-dimensional acceleration factors of up to R = 4 without impairing image quality significantly. Conclusion The modular 32-channel transceiver cardiac array supports accelerated and high spatial resolution cardiac MRI. The array is compatible with multichannel transmission and provides a technological basis for future clinical assessment of parallel transmission techniques at 7.0T.}, language = {en} }