TY - JOUR A1 - Philipp, Mohr A1 - Efthimiou, Nikos A1 - Pagano, Fiammetta A1 - Kratochwil, Nicolaus A1 - Pizzichemi, Marco A1 - Tsoumpas, Charalampos A1 - Auffray, Etiennette A1 - Ziemons, Karl T1 - Image reconstruction analysis for positron emission tomography with heterostructured scintillators JF - IEEE Transactions on Radiation and Plasma Medical Sciences N2 - The concept of structure engineering has been proposed for exploring the next generation of radiation detectors with improved performance. A TOF-PET geometry with heterostructured scintillators with a pixel size of 3.0×3.1×15 mm3 was simulated using Monte Carlo. The heterostructures consisted of alternating layers of BGO as a dense material with high stopping power and plastic (EJ232) as a fast light emitter. The detector time resolution was calculated as a function of the deposited and shared energy in both materials on an event-by-event basis. While sensitivity was reduced to 32% for 100 μm thick plastic layers and 52% for 50 μm, the CTR distribution improved to 204±49 ps and 220±41 ps respectively, compared to 276 ps that we considered for bulk BGO. The complex distribution of timing resolutions was accounted for in the reconstruction. We divided the events into three groups based on their CTR and modeled them with different Gaussian TOF kernels. On a NEMA IQ phantom, the heterostructures had better contrast recovery in early iterations. On the other hand, BGO achieved a better contrast to noise ratio (CNR) after the 15th iteration due to the higher sensitivity. The developed simulation and reconstruction methods constitute new tools for evaluating different detector designs with complex time responses. KW - TOF PET KW - Heterostructure KW - Metascintillator KW - Multiple TOF kernels KW - Image Reconstruction Y1 - 2022 U6 - https://doi.org/10.1109/TRPMS.2022.3208615 SN - 2469-7311 SN - 2469-7303 VL - 7 IS - 1 SP - 41 EP - 51 PB - IEEE CY - New York, NY ER - TY - JOUR A1 - Czarnecki, Christian A1 - Dietze, Christian T1 - Gestaltungsorientierte Forschung am Beispiel der Referenzmodellierung in der Telekommunikationsindustrie JF - HMD Praxis der Wirtschaftsinformatik N2 - Am Beispiel der Telekommunikationsindustrie zeigt der Beitrag eine konkrete Ausgestaltung anwendungsorientierter Forschung, die sowohl für die Praxis als auch für die Wissenschaft nutzen- und erkenntnisbringend ist. Forschungsgegenstand sind die Referenzmodelle des Industriegremiums TM Forum, die von vielen Telekommunikationsunternehmen zur Transformation ihrer Strukturen und Systeme genutzt werden. Es wird die langjährige Forschungstätigkeit bei der Weiterentwicklung und Anwendung dieser Referenzmodelle beschrieben. Dabei wird ein konsequent gestaltungsorientierter Forschungsansatz verfolgt. Das Zusammenspiel aus kontinuierlicher Weiterentwicklung in Zusammenarbeit mit einem Industriegremium und der Anwendung in vielfältigen Praxisprojekten führt zu einer erfolgreichen Symbiose aus praktischer Nutzengenerierung sowie wissenschaftlichem Erkenntnisgewinn. Der Beitrag stellt den gewählten Forschungsansatz anhand konkreter Beispiele vor. Darauf basierend werden Empfehlungen und Herausforderungen für eine gestaltungs- und praxisorientierte Forschung diskutiert. KW - Design Science Research KW - Anwendungsorientierter Forschungsansatz KW - Praxisprojekte KW - Referenzmodellierung KW - Enhanced Telecom Operations Map Y1 - 2020 U6 - https://doi.org/10.1365/s40702-020-00594-y SN - 2198-2775 VL - 57 IS - 2 SP - 310 EP - 323 PB - Springer Nature CY - Cham ER - TY - JOUR A1 - Kilic, S. A. A1 - Raatschen, Hans-Jürgen A1 - Körfgen, B. A1 - Apaydin, N. M. A1 - Astaneh-Asl, A. T1 - FE Model of the Fatih Sultan Mehmet Suspension Bridge Using Thin Shell Finite Elements JF - Arabian Journal for Science and Engineering N2 - This paper presents the results of an eigenvalue analysis of the Fatih Sultan Mehmet Bridge. A high-resolution finite element model was created directly from the available design documents. All physical properties of the structural components were included in detail, so no calibration to the measured data was necessary. The deck and towers were modeled with shell elements. A nonlinear static analysis was performed before the eigenvalue calculation. The calculated natural frequencies and corresponding mode shapes showed good agreement with the available measured ambient vibration data. The calculation of the effective modal mass showed that nine modes had single contributions higher than 5 % of the total mass. They were in a frequency range up to 1.2 Hz. The comparison of the results for the torsional modes especially demonstrated the advantage of using thin shell finite elements over the beam modeling approach. KW - Suspension bridge KW - 3D nonlinear finite element model KW - Thin shell finite elements KW - Natural frequency KW - Effective modal mass Y1 - 2017 U6 - https://doi.org/10.1007/s13369-016-2316-y SN - 2191-4281 VL - 42 IS - 3 SP - 1103 EP - 1116 PB - Springer Nature ER - TY - JOUR A1 - Capri, Miriam A1 - Morsiani, Cristina A1 - Santoro, Aurelia A1 - Moriggi, Manuela A1 - Conte, Maria A1 - Martucci, Morena A1 - Bellavista, Elena A1 - Fabbri, Cristina A1 - Giampieri, Enrico A1 - Albracht, Kirsten A1 - Flück, Martin A1 - Ruoss, Severin A1 - Brocca, Lorenza A1 - Canepari, Monica A1 - Longa, Emanuela A1 - Giulio, Irene Di A1 - Bottinelli, Roberto A1 - Cerretelli, Paolo A1 - Salvioli, Stefano A1 - Gelfi, Cecilia A1 - Franceschi, Claudio A1 - Narici, Marco A1 - Rittweger, Jörn T1 - Recovery from 6-month spaceflight at the International Space Station: muscle-related stress into a proinflammatory setting JF - The FASEB journal : official publication of the Federation of American Societies for Experimental Biology Y1 - 2019 U6 - https://doi.org/10.1096/fj.201801625R VL - 33 IS - 4 SP - 5168 EP - 5180 ER - TY - JOUR A1 - Moret, J.L.T.M. A1 - Alkemade, J. A1 - Upcraft, T.M. A1 - Paulßen, Elisabeth A1 - Wolterbeek, H.T. A1 - Ommen, J.R. van A1 - Denkova, A.G. T1 - The application of atomic layer deposition in the production of sorbents for ⁹⁹Mo/⁹⁹ᵐTc generator JF - Applied Radiation and Isotopes N2 - New production routes for ⁹⁹Mo are steadily gaining importance. However, the obtained specific activity is much lower than currently produced by the fission of U-235. To be able to supply hospitals with ⁹⁹Mo/⁹⁹ᵐTc generators with the desired activity, the adsorption capacity of the column material should be increased. In this paper we have investigated whether the gas phase coating technique Atomic Layer Deposition (ALD), which can deposit ultra-thin layers on high surface area materials, can be used to attain materials with high adsorption capacity for ⁹⁹Mo. For this purpose, ALD was applied on a silica-core sorbent material to coat it with a thin layer of alumina. This sorbent material shows to have a maximum adsorption capacity of 120 mg/g and has a ⁹⁹ᵐTc elution efficiency of 55 ± 2% based on 3 executive elutions. Y1 - 2020 U6 - https://doi.org/10.1016/j.apradiso.2020.109266 SN - 0969-8043 VL - 164 IS - 109266 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Choi, Chang-Hoon A1 - Felder, Tim A1 - Felder, Jörg A1 - Tellmann, Lutz A1 - Hong, Suk-Min A1 - Wegener, Hans-Peter A1 - Shah, N Jon A1 - Ziemons, Karl T1 - Design, evaluation and comparison of endorectal coils for hybrid MR-PET imaging of the prostate JF - Physics in Medicine & Biology N2 - Prostate cancer is one of the most common cancers among men and its early detection is critical for its successful treatment. The use of multimodal imaging, such as MR-PET, is most advantageous as it is able to provide detailed information about the prostate. However, as the human prostate is flexible and can move into different positions under external conditions, it is important to localise the focused region-of-interest using both MRI and PET under identical circumstances. In this work, we designed five commonly used linear and quadrature radiofrequency surface coils suitable for hybrid MR-PET use in endorectal applications. Due to the endorectal design and the shielded PET insert, the outer face of the coils investigated was curved and the region to be imaged was outside the volume of the coil. The tilting angles of the coils were varied with respect to the main magnetic field direction. This was done to approximate the various positions from which the prostate could be imaged. The transmit efficiencies and safety excitation efficiencies from simulations, together with the signal-to-noise ratios from the MR images were calculated and analysed. Overall, it was found that the overlapped loops driven in quadrature were superior to the other types of coils we tested. In order to determine the effect of the different coil designs on PET, transmission scans were carried out, and it was observed that the differences between attenuation maps with and without the coils were negligible. The findings of this work can provide useful guidance for the integration of such coil designs into MR-PET hybrid systems in the future. Y1 - 2020 U6 - https://doi.org/10.1088/1361-6560/ab87f8 SN - 0031-9155 VL - 65 IS - 11 PB - IOP CY - Bristol ER - TY - JOUR A1 - Orzada, Stephan A1 - Fiedler, Thomas M. A1 - Bitz, Andreas A1 - Ladd, Mark E. A1 - Quick, Harald H. T1 - Local SAR compression with overestimation control to reduce maximum relative SAR overestimation and improve multi-channel RF array performance JF - Magnetic Resonance Materials in Physics, Biology and Medicine N2 - 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. Y1 - 2020 SN - 1352-8661 U6 - https://doi.org/10.1007/s10334-020-00890-0 IS - 34 (2021) SP - 153 EP - 164 PB - Springer CY - Heidelberg ER - TY - JOUR A1 - Oliveira, Danilo A. A1 - Molinnus, Denise A1 - Beging, Stefan A1 - Siqueira Jr, José R. A1 - Schöning, Michael Josef T1 - Biosensor Based on Self-Assembled Films of Graphene Oxide and Polyaniline Using a Field-Effect Device Platform JF - physica status solidi (a) applications and materials science N2 - A new functionalization method to modify capacitive electrolyte–insulator–semiconductor (EIS) structures with nanofilms is presented. Layers of polyallylamine hydrochloride (PAH) and graphene oxide (GO) with the compound polyaniline:poly(2-acrylamido-2-methyl-1-propanesulfonic acid) (PANI:PAAMPSA) are deposited onto a p-Si/SiO2 chip using the layer-by-layer technique (LbL). Two different enzymes (urease and penicillinase) are separately immobilized on top of a five-bilayer stack of the PAH:GO/PANI:PAAMPSA-modified EIS chip, forming a biosensor for detection of urea and penicillin, respectively. Electrochemical characterization is performed by constant capacitance (ConCap) measurements, and the film morphology is characterized by atomic force microscopy (AFM) and scanning electron microscopy (SEM). An increase in the average sensitivity of the modified biosensors (EIS–nanofilm–enzyme) of around 15% is found in relation to sensors, only carrying the enzyme but without the nanofilm (EIS–enzyme). In this sense, the nanofilm acts as a stable bioreceptor onto the EIS chip improving the output signal in terms of sensitivity and stability. KW - capacitive electrolyte–insulator–semiconductor sensors KW - graphene oxide KW - layer-by-layer technique KW - nanomaterials KW - polyaniline Y1 - 2021 U6 - https://doi.org/10.1002/pssa.202000747 SN - 1862-6319 N1 - Corresponding author: José R. Siqueira Jr & Michael J. Schöning VL - 218 IS - 13 SP - 1 EP - 9 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Heel, Mareike van A1 - Dikta, Gerhard A1 - Braekers, Roel T1 - Bootstrap based goodness‑of‑fit tests for binary multivariate regression models JF - Journal of the Korean Statistical Society N2 - We consider a binary multivariate regression model where the conditional expectation of a binary variable given a higher-dimensional input variable belongs to a parametric family. Based on this, we introduce a model-based bootstrap (MBB) for higher-dimensional input variables. This test can be used to check whether a sequence of independent and identically distributed observations belongs to such a parametric family. The approach is based on the empirical residual process introduced by Stute (Ann Statist 25:613–641, 1997). In contrast to Stute and Zhu’s approach (2002) Stute & Zhu (Scandinavian J Statist 29:535–545, 2002), a transformation is not required. Thus, any problems associated with non-parametric regression estimation are avoided. As a result, the MBB method is much easier for users to implement. To illustrate the power of the MBB based tests, a small simulation study is performed. Compared to the approach of Stute & Zhu (Scandinavian J Statist 29:535–545, 2002), the simulations indicate a slightly improved power of the MBB based method. Finally, both methods are applied to a real data set. Y1 - 2021 U6 - https://doi.org/10.1007/s42952-021-00142-4 SN - 2005-2863 (Online) SN - 1226-3192 (Print) N1 - Corresponding author: Mareike van Heel VL - 51 PB - Springer Nature CY - Singapur ER - TY - JOUR A1 - Altherr, Lena A1 - Leise, Philipp A1 - Pfetsch, Marc E. A1 - Schmitt, Andreas T1 - Algorithmic design and resilience assessment of energy efficient high-rise water supply systems JF - Applied Mechanics and Materials N2 - High-rise water supply systems provide water flow and suitable pressure in all levels of tall buildings. To design such state-of-the-art systems, the consideration of energy efficiency and the anticipation of component failures are mandatory. In this paper, we use Mixed-Integer Nonlinear Programming to compute an optimal placement of pipes and pumps, as well as an optimal control strategy.Moreover, we consider the resilience of the system to pump failures. A resilient system is able to fulfill a predefined minimum functionality even though components fail or are restricted in their normal usage. We present models to measure and optimize the resilience. To demonstrate our approach, we design and analyze an optimal resilient decentralized water supply system inspired by a real-life hotel building. KW - MINLP KW - Buffering Capacity KW - Uncertainty KW - Water Supply Networks KW - Booster Stations Y1 - 2018 U6 - https://doi.org/10.4028/www.scientific.net/AMM.885.211 SN - 1662-7482 VL - 885 SP - 211 EP - 223 PB - Trans Tech Publications CY - Bäch ER - TY - JOUR A1 - Jahnke, Siegfried A1 - Roussel, Johanna A1 - Hombach, Thomas A1 - Kochs, Johannes A1 - Fischbach, Andreas A1 - Huber, Gregor A1 - Scharr, Hanno T1 - phenoSeeder - A robot system for automated handling and phenotyping of individual seeds JF - Plant physiology N2 - The enormous diversity of seed traits is an intriguing feature and critical for the overwhelming success of higher plants. In particular, seed mass is generally regarded to be key for seedling development but is mostly approximated by using scanning methods delivering only two-dimensional data, often termed seed size. However, three-dimensional traits, such as the volume or mass of single seeds, are very rarely determined in routine measurements. Here, we introduce a device named phenoSeeder, which enables the handling and phenotyping of individual seeds of very different sizes. The system consists of a pick-and-place robot and a modular setup of sensors that can be versatilely extended. Basic biometric traits detected for individual seeds are two-dimensional data from projections, three-dimensional data from volumetric measures, and mass, from which seed density is also calculated. Each seed is tracked by an identifier and, after phenotyping, can be planted, sorted, or individually stored for further evaluation or processing (e.g. in routine seed-to-plant tracking pipelines). By investigating seeds of Arabidopsis (Arabidopsis thaliana), rapeseed (Brassica napus), and barley (Hordeum vulgare), we observed that, even for apparently round-shaped seeds of rapeseed, correlations between the projected area and the mass of seeds were much weaker than between volume and mass. This indicates that simple projections may not deliver good proxies for seed mass. Although throughput is limited, we expect that automated seed phenotyping on a single-seed basis can contribute valuable information for applications in a wide range of wild or crop species, including seed classification, seed sorting, and assessment of seed quality. Y1 - 2016 U6 - https://doi.org/10.1104/pp.16.01122 SN - 0032-0889 VL - 172 IS - 3 SP - 1358 EP - 1370 PB - Oxford University Press CY - Oxford ER - TY - JOUR A1 - Vos, E. K. A1 - Lagemaat, M. W. A1 - Barentsz, J. O. A1 - Fütterer, J. J. A1 - Zamecnik, P. A1 - Roozen, H. A1 - Orzada, S. A1 - Bitz, Andreas A1 - Maas, M. C. A1 - Scheenen, T. W. J. T1 - Image quality and cancer visibility of T2-weighted Magnetic Resonance Imaging of the prostate at 7 Tesla JF - European Radiology N2 - Objectives To assess the image quality of T2-weighted (T2w) magnetic resonance imaging of the prostate and the visibility of prostate cancer at 7 Tesla (T). Materials & methods Seventeen prostate cancer patients underwent T2w imaging at 7T with only an external transmit/receive array coil. Three radiologists independently scored images for image quality, visibility of anatomical structures, and presence of artefacts. Krippendorff’s alpha and weighted kappa statistics were used to assess inter-observer agreement. Visibility of prostate cancer lesions was assessed by directly linking the T2w images to the confirmed location of prostate cancer on histopathology. Results T2w imaging at 7T was achievable with ‘satisfactory’ (3/5) to ‘good’ (4/5) quality. Visibility of anatomical structures was predominantly scored as ‘satisfactory’ (3/5) and ‘good’ (4/5). If artefacts were present, they were mostly motion artefacts and, to a lesser extent, aliasing artefacts and noise. Krippendorff’s analysis revealed an α = 0.44 between three readers for the overall image quality scores. Clinically significant cancer lesions in both peripheral zone and transition zone were visible at 7T. Conclusion T2w imaging with satisfactory to good quality can be routinely acquired, and cancer lesions were visible in patients with prostate cancer at 7T using only an external transmit/receive body array coil. Y1 - 2014 U6 - https://doi.org/10.1007/s00330-014-3234-6 SN - 1432-1084 VL - 24 IS - 8 SP - 1950 EP - 1958 PB - Springer CY - Cham ER - TY - JOUR A1 - de Blois, Eric A1 - de Zanger, Rory M. S. A1 - Paulßen, Elisabeth A1 - Sze Chan, Ho A1 - Breeman, Wouter A. P. T1 - Semi-automated system for concentrating 68Ga-eluate to obtain high molar and volume concentration of 68Ga-Radiopharmaca for preclinical applications JF - Nuclear Medicine and Biology N2 - 68Ga-radiopharmaceuticals are common in the field of Nuclear Medicine to visualize receptor-mediated processes. In contrast to straightforward labeling procedures for clinical applications, preclinical in vitro and in vivo applications are hampered for reasons like e.g. volume restriction, activity concentration, molar activity and osmolality. Therefore, we developed a semiautomatic system specifically to overcome these problems. A difficulty appeared unexpectedly, as intrinsic trace metals derived from eluate (Zn, Fe and Cu) are concentrated as well in amounts that influence radiochemical yield and thus lower molar activity. Y1 - 2018 U6 - https://doi.org/10.1016/j.nucmedbio.2018.06.006 VL - 64-65 SP - 16 EP - 21 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Eckert, Alexander A1 - Abbasi, Mozhdeh A1 - Mang, Thomas A1 - Saalwächter, Kay A1 - Walther, Andreas T1 - Structure, Mechanical Properties, and Dynamics of Polyethylenoxide/Nanoclay Nacre-Mimetic Nanocomposites JF - Macromolecules N2 - Nacre-mimetic nanocomposites based on high fractions of synthetic high-aspect-ratio nanoclays in combination with polymers are continuously pushing boundaries for advanced material properties, such as high barrier against oxygen, extraordinary mechanical behavior, fire shielding, and glass-like transparency. Additionally, they provide interesting model systems to study polymers under nanoconfinement due to the well-defined layered nanocomposite arrangement. Although the general behavior in terms of forming such layered nanocomposite materials using evaporative self-assembly and controlling the nanoclay gallery spacing by the nanoclay/polymer ratio is understood, some combinations of polymer matrices and nanoclay reinforcement do not comply with the established models. Here, we demonstrate a thorough characterization and analysis of such an unusual polymer/nanoclay pair that falls outside of the general behavior. Poly(ethylene oxide) (PEO) and sodium fluorohectorite form nacre-mimetic, lamellar nanocomposites that are completely transparent and show high mechanical stiffness and high gas barrier, but there is only limited expansion of the nanoclay gallery spacing when adding increasing amounts of polymer. This behavior is maintained for molecular weights of PEO varied over four orders of magnitude and can be traced back to depletion forces. By careful investigation via X-ray diffraction and proton low-resolution solid-state NMR, we are able to quantify the amount of mobile and immobilized polymer species in between the nanoclay galleries and around proposed tactoid stacks embedded in a PEO matrix. We further elucidate the unusual confined polymer dynamics, indicating a relevant role of specific surface interactions. Y1 - 2020 U6 - https://doi.org/10.1021/acs.macromol.9b01931 SN - 1520-5835 VL - 53 IS - 5 SP - 1716 EP - 1725 PB - ACS Publications CY - Washington, DC ER - TY - JOUR A1 - Jildeh, Zaid B. A1 - Wagner, Patrick H. A1 - Schöning, Michael Josef T1 - Sterilization of Objects, Products, and Packaging Surfaces and Their Characterization in Different Fields of Industry: The Status in 2020 JF - physica status solidi (a) applications and materials science N2 - The treatment method to deactivate viable microorganisms from objects or products is termed sterilization. There are multiple forms of sterilization, each intended to be applied for a specific target, which depends on—but not limited to—the thermal, physical, and chemical stability of that target. Herein, an overview on the currently used sterilization processes in the global market is provided. Different sterilization techniques are grouped under a category that describes the method of treatment: radiation (gamma, electron beam, X-ray, and ultraviolet), thermal (dry and moist heat), and chemical (ethylene oxide, ozone, chlorine dioxide, and hydrogen peroxide). For each sterilization process, the typical process parameters as defined by regulations and the mode of antimicrobial activity are summarized. Finally, the recommended microorganisms that are used as biological indicators to validate sterilization processes in accordance with the rules that are established by various regulatory agencies are summarized. KW - bioburdens KW - sterility tests KW - sterilization efficacy KW - sterilization methods KW - validation methods Y1 - 2021 U6 - https://doi.org/10.1002/pssa.202000732 SN - 1862-6319 N1 - Corresponding author: Michael J. Schöning VL - 218 IS - 13 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Wert, Stefan A1 - Iken, Heiko A1 - Schöning, Michael Josef A1 - Matysik, Frank-Michael T1 - Development of a temperature‐pulse enhanced electrochemical glucose biosensor and characterization of its stability via scanning electrochemical microscopy JF - Electroanalysis N2 - Glucose oxidase (GOx) is an enzyme frequently used in glucose biosensors. As increased temperatures can enhance the performance of electrochemical sensors, we investigated the impact of temperature pulses on GOx that was drop-coated on flattened Pt microwires. The wires were heated by an alternating current. The sensitivity towards glucose and the temperature stability of GOx was investigated by amperometry. An up to 22-fold increase of sensitivity was observed. Spatially resolved enzyme activity changes were investigated via scanning electrochemical microscopy. The application of short (<100 ms) heat pulses was associated with less thermal inactivation of the immobilized GOx than long-term heating. Y1 - 2021 U6 - https://doi.org/10.1002/elan.202100089 SN - 1521-4109 IS - Early View PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Fiedler, Thomas M. A1 - Orzada, Stephan A1 - Flöser, Martina A1 - Rietsch, Stefan H. G. A1 - Schmidt, Simon A1 - Stelter, Jonathan K. A1 - Wittrich, Marco A1 - Quick, Harald H. A1 - Bitz, Andreas A1 - Ladd, Mark E. T1 - Performance and safety assessment of an integrated transmit array for body imaging at 7 T under consideration of specificabsorption rate, tissue temperature, and thermal dose JF - NMR in Biomedicine N2 - In this study, the performance of an integrated body-imaging array for 7 T with 32 radiofrequency (RF) channels under consideration of local specific absorption rate (SAR), tissue temperature, and thermal dose limits was evaluated and the imaging performance was compared with a clinical 3 T body coil. Thirty-two transmit elements were placed in three rings between the bore liner and RF shield of the gradient coil. Slice-selective RF pulse optimizations for B1 shimming and spokes were performed for differently oriented slices in the body under consideration of realistic constraints for power and local SAR. To improve the B1+ homogeneity, safety assessments based on temperature and thermal dose were performed to possibly allow for higher input power for the pulse optimization than permissible with SAR limits. The results showed that using two spokes, the 7 T array outperformed the 3 T birdcage in all the considered regions of interest. However, a significantly higher SAR or lower duty cycle at 7 T is necessary in some cases to achieve similar B1+ homogeneity as at 3 T. The homogeneity in up to 50 cm-long coronal slices can particularly benefit from the high RF shim performance provided by the 32 RF channels. The thermal dose approach increases the allowable input power and the corresponding local SAR, in one example up to 100 W/kg, without limiting the exposure time necessary for an MR examination. In conclusion, the integrated antenna array at 7 T enables a clinical workflow for body imaging and comparable imaging performance to a conventional 3 T clinical body coil. KW - body imaging at 7 T MRI KW - thermal dose KW - tissue temperature KW - transmit antenna arrays Y1 - 2022 U6 - https://doi.org/10.1002/nbm.4656 SN - 0952-3480 (Print) SN - 1099-1492 (Online) VL - 35 IS - 5 SP - 1 EP - 17 PB - Wiley ER - TY - JOUR A1 - Haeger, Gerrit A1 - Grankin, Alina A1 - Wagner, Michaela T1 - Construction of an Aspergillus oryzae triple amylase deletion mutant as a chassis to evaluate industrially relevant amylases using multiplex CRISPR/Cas9 editing technology JF - Applied Research N2 - Aspergillus oryzae is an industrially relevant organism for the secretory production of heterologous enzymes, especially amylases. The activities of potential heterologous amylases, however, cannot be quantified directly from the supernatant due to the high background activity of native α-amylase. This activity is caused by the gene products of amyA, amyB, and amyC. In this study, an in vitro CRISPR/Cas9 system was established in A. oryzae to delete these genes simultaneously. First, pyrG of A. oryzae NSAR1 was mutated by exploiting NHEJ to generate a counter-selection marker. Next, all amylase genes were deleted simultaneously by co-transforming a repair template carrying pyrG of Aspergillus nidulans and flanking sequences of amylase gene loci. The rate of obtained triple knock-outs was 47%. We showed that triple knockouts do not retain any amylase activity in the supernatant. The established in vitro CRISPR/Cas9 system was used to achieve sequence-specific knock-in of target genes. The system was intended to incorporate a single copy of the gene of interest into the desired host for the development of screening methods. Therefore, an integration cassette for the heterologous Fpi amylase was designed to specifically target the amyB locus. The site-specific integration rate of the plasmid was 78%, with exceptional additional integrations. Integration frequency was assessed via qPCR and directly correlated with heterologous amylase activity. Hence, we could compare the efficiency between two different signal peptides. In summary, we present a strategy to exploit CRISPR/Cas9 for gene mutation, multiplex knock-out, and the targeted knock-in of an expression cassette in A. oryzae. Our system provides straightforward strain engineering and paves the way for development of fungal screening systems. KW - aspergillus KW - CRISPR/Cas9 KW - filamentous fungi KW - genome engineering Y1 - 2023 U6 - https://doi.org/10.1002/appl.202200106 SN - 2702-4288 IS - Early View SP - 1 EP - 15 PB - Wiley-VCH ER - TY - JOUR A1 - Kempt, Hendrik A1 - Freyer, Nils A1 - Nagel, Saskia K. T1 - Justice and the normative standards of explainability in healthcare JF - Philosophy & Technology N2 - Providing healthcare services frequently involves cognitively demanding tasks, including diagnoses and analyses as well as complex decisions about treatments and therapy. From a global perspective, ethically significant inequalities exist between regions where the expert knowledge required for these tasks is scarce or abundant. One possible strategy to diminish such inequalities and increase healthcare opportunities in expert-scarce settings is to provide healthcare solutions involving digital technologies that do not necessarily require the presence of a human expert, e.g., in the form of artificial intelligent decision-support systems (AI-DSS). Such algorithmic decision-making, however, is mostly developed in resource- and expert-abundant settings to support healthcare experts in their work. As a practical consequence, the normative standards and requirements for such algorithmic decision-making in healthcare require the technology to be at least as explainable as the decisions made by the experts themselves. The goal of providing healthcare in settings where resources and expertise are scarce might come with a normative pull to lower the normative standards of using digital technologies in order to provide at least some healthcare in the first place. We scrutinize this tendency to lower standards in particular settings from a normative perspective, distinguish between different types of absolute and relative, local and global standards of explainability, and conclude by defending an ambitious and practicable standard of local relative explainability. KW - Clinical decision support systems KW - Justice KW - Medical AI KW - Explainability KW - Normative standards Y1 - 2022 U6 - https://doi.org/10.1007/s13347-022-00598-0 VL - 35 IS - Article number: 100 SP - 1 EP - 19 PB - Springer Nature CY - Berlin ER - TY - JOUR A1 - Özsoylu, Dua A1 - Aliazizi, Fereshteh A1 - Wagner, Patrick A1 - Schöning, Michael Josef T1 - Template bacteria-free fabrication of surface imprinted polymer-based biosensor for E. coli detection using photolithographic mimics: Hacking bacterial adhesion JF - Biosensors and Bioelectronics N2 - As one class of molecular imprinted polymers (MIPs), surface imprinted polymer (SIP)-based biosensors show great potential in direct whole-bacteria detection. Micro-contact imprinting, that involves stamping the template bacteria immobilized on a substrate into a pre-polymerized polymer matrix, is the most straightforward and prominent method to obtain SIP-based biosensors. However, the major drawbacks of the method arise from the requirement for fresh template bacteria and often non-reproducible bacteria distribution on the stamp substrate. Herein, we developed a positive master stamp containing photolithographic mimics of the template bacteria (E. coli) enabling reproducible fabrication of biomimetic SIP-based biosensors without the need for the “real” bacteria cells. By using atomic force and scanning electron microscopy imaging techniques, respectively, the E. coli-capturing ability of the SIP samples was tested, and compared with non-imprinted polymer (NIP)-based samples and control SIP samples, in which the cavity geometry does not match with E. coli cells. It was revealed that the presence of the biomimetic E. coli imprints with a specifically designed geometry increases the sensor E. coli-capturing ability by an “imprinting factor” of about 3. These findings show the importance of geometry-guided physical recognition in bacterial detection using SIP-based biosensors. In addition, this imprinting strategy was employed to interdigitated electrodes and QCM (quartz crystal microbalance) chips. E. coli detection performance of the sensors was demonstrated with electrochemical impedance spectroscopy (EIS) and QCM measurements with dissipation monitoring technique (QCM-D). KW - Surface imprinted polymer KW - E. coli detection KW - Photolithographic mimics KW - Master stamp KW - Quartz crystal microbalance Y1 - 2024 U6 - https://doi.org/10.1016/j.bios.2024.116491 SN - 1873-4235 (eISSN) SN - 0956-5663 N1 - Corresponding author: Michael J. Schöning VL - 261 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Werkhausen, Amelie A1 - Willwacher, Steffen A1 - Albracht, Kirsten T1 - Medial gastrocnemius muscle fascicles shorten throughout stance during sprint acceleration JF - Scandinavian Journal of Medicine & Science in Sports N2 - The compliant nature of distal limb muscle-tendon units is traditionally considered suboptimal in explosive movements when positive joint work is required. However, during accelerative running, ankle joint net mechanical work is positive. Therefore, this study aims to investigate how plantar flexor muscle-tendon behavior is modulated during fast accelerations. Eleven female sprinters performed maximum sprint accelerations from starting blocks, while gastrocnemius muscle fascicle lengths were estimated using ultrasonography. We combined motion analysis and ground reaction force measurements to assess lower limb joint kinematics and kinetics, and to estimate gastrocnemius muscle-tendon unit length during the first two acceleration steps. Outcome variables were resampled to the stance phase and averaged across three to five trials. Relevant scalars were extracted and analyzed using one-sample and two-sample t-tests, and vector trajectories were compared using statistical parametric mapping. We found that an uncoupling of muscle fascicle behavior from muscle-tendon unit behavior is effectively used to produce net positive mechanical work at the joint during maximum sprint acceleration. Muscle fascicles shortened throughout the first and second steps, while shortening occurred earlier during the first step, where negative joint work was lower compared with the second step. Elastic strain energy may be stored during dorsiflexion after touchdown since fascicles did not lengthen at the same time to dissipate energy. Thus, net positive work generation is accommodated by the reuse of elastic strain energy along with positive gastrocnemius fascicle work. Our results show a mechanism of how muscles with high in-series compliance can contribute to net positive joint work. KW - locomotion KW - muscle mechanics KW - running KW - sprint start KW - ultrasonography Y1 - 2021 U6 - https://doi.org/10.1111/sms.13956 SN - 0905-7188 (Druckausgabe) SN - 1600-0838 (Onlineausgabe) VL - 31 IS - 7 SP - 1471 EP - 1480 PB - Wiley-Blackwell CY - Oxford ER - TY - JOUR A1 - Kuchler, Timon A1 - Günthner, Roman A1 - Ribeiro, Andrea A1 - Hausinger, Renate A1 - Streese, Lukas A1 - Wöhnl, Anna A1 - Kesseler, Veronika A1 - Negele, Johanna A1 - Assali, Tarek A1 - Carbajo-Lozoya, Javier A1 - Lech, Maciej A1 - Adorjan, Kristina A1 - Stubbe, Hans Christian A1 - Hanssen, Henner A1 - Kotliar, Konstantin A1 - Haller, Berhard A1 - Heemann, Uwe A1 - Schmaderer, Christoph T1 - Persistent endothelial dysfunction in post-COVID-19 syndrome and its associations with symptom severity and chronic inflammation N2 - Background Post-COVID-19 syndrome (PCS) is a lingering disease with ongoing symptoms such as fatigue and cognitive impairment resulting in a high impact on the daily life of patients. Understanding the pathophysiology of PCS is a public health priority, as it still poses a diagnostic and treatment challenge for physicians. Methods In this prospective observational cohort study, we analyzed the retinal microcirculation using Retinal Vessel Analysis (RVA) in a cohort of patients with PCS and compared it to an age- and gender-matched healthy cohort (n = 41, matched out of n = 204). Measurements and main results PCS patients exhibit persistent endothelial dysfunction (ED), as indicated by significantly lower venular flicker-induced dilation (vFID; 3.42% ± 1.77% vs. 4.64% ± 2.59%; p = 0.02), narrower central retinal artery equivalent (CRAE; 178.1 [167.5–190.2] vs. 189.1 [179.4–197.2], p = 0.01) and lower arteriolar-venular ratio (AVR; (0.84 [0.8–0.9] vs. 0.88 [0.8–0.9], p = 0.007). When combining AVR and vFID, predicted scores reached good ability to discriminate groups (area under the curve: 0.75). Higher PCS severity scores correlated with lower AVR (R = − 0.37 p = 0.017). The association of microvascular changes with PCS severity were amplified in PCS patients exhibiting higher levels of inflammatory parameters. Conclusion Our results demonstrate that prolonged endothelial dysfunction is a hallmark of PCS, and impairments of the microcirculation seem to explain ongoing symptoms in patients. As potential therapies for PCS emerge, RVA parameters may become relevant as clinical biomarkers for diagnosis and therapy management. KW - Endothelial dysfunction KW - Long COVID KW - Post-COVID-19 syndrome KW - retinal microvasculature Y1 - 2023 U6 - https://doi.org/10.1007/s10456-023-09885-6 N1 - Corresponding author: Christoph Schmaderer VL - 26 SP - 547 EP - 563 PB - Springer Nature CY - Dordrecht ER - TY - JOUR A1 - Kuerten, David A1 - Kotliar, Konstantin A1 - Fuest, Matthias A1 - Walter, Peter A1 - Hollstein, Muriel A1 - Plange, Niklas ED - Neri, Piergiorgio T1 - Does hemispheric vascular regulation differ significantly in glaucoma patients with altitudinal visual field asymmetry? A single-center, prospective study JF - International Ophthalmology N2 - Purpose Vascular risk factors and ocular perfusion are heatedly discussed in the pathogenesis of glaucoma. The retinal vessel analyzer (RVA, IMEDOS Systems, Germany) allows noninvasive measurement of retinal vessel regulation. Significant differences especially in the veins between healthy subjects and patients suffering from glaucoma were previously reported. In this pilot-study we investigated if localized vascular regulation is altered in glaucoma patients with altitudinal visual field defect asymmetry. Methods 15 eyes of 12 glaucoma patients with advanced altitudinal visual field defect asymmetry were included. The mean defect was calculated for each hemisphere separately (-20.99 ± 10.49 pro- found hemispheric visual field defect vs -7.36 ± 3.97 dB less profound hemisphere). After pupil dilation, RVA measurements of retinal arteries and veins were conducted using the standard protocol. The superior and inferior retinal vessel reactivity were measured consecutively in each eye. Results Significant differences were recorded in venous vessel constriction after flicker light stimulation and overall amplitude of the reaction (p \ 0.04 and p \ 0.02 respectively) in-between the hemispheres spheres. Vessel reaction was higher in the hemisphere corresponding to the more advanced visual field defect. Arterial diameters reacted similarly, failing to reach statistical significance. Conclusion Localized retinal vessel regulation is significantly altered in glaucoma patients with asymmetri altitudinal visual field defects. Veins supplying the hemisphere concordant to a less profound visual field defect show diminished diameter changes. Vascular dysregulation might be particularly important in early glaucoma stages prior to a significant visual field defect. KW - Glaucoma KW - Visual field asymmetry KW - Ocular blood flow KW - RVA KW - Vascular response Y1 - 2021 SN - 1573-2630 U6 - https://doi.org/10.1007/s10792-021-01876-0 VL - 41 IS - 41 SP - 3109 EP - 3119 PB - Springer CY - Berlin ER - TY - JOUR A1 - Hamou, Hussam Aldin A1 - Kotliar, Konstantin A1 - Tan, Sonny Kian A1 - Weiß, Christel A1 - Blume, Christian A1 - Clusmann, Hans A1 - Schubert, Gerrit Alexander A1 - Albanna, Walid T1 - Surgical nuances and placement of subgaleal drains for supratentorial procedures—a prospective analysis of efficacy and outcome in 150 craniotomies JF - Acta Neurochirurgica N2 - Background For supratentorial craniotomy, surgical access, and closure technique, including placement of subgaleal drains, may vary considerably. The influence of surgical nuances on postoperative complications such as cerebrospinal fluid leakage or impaired wound healing overall remains largely unclear. With this study, we are reporting our experiences and the impact of our clinical routines on outcome in a prospectively collected data set. Method We prospectively observed 150 consecutive patients undergoing supratentorial craniotomy and recorded technical variables (type/length of incision, size of craniotomy, technique of dural and skin closure, type of dressing, and placement of subgaleal drains). Outcome variables (subgaleal hematoma/CSF collection, periorbital edema, impairment of wound healing, infection, and need for operative revision) were recorded at time of discharge and at late follow-up. Results Early subgaleal fluid collection was observed in 36.7% (2.8% at the late follow-up), and impaired wound healing was recorded in 3.3% of all cases, with an overall need for operative revision of 6.7%. Neither usage of dural sealants, lack of watertight dural closure, and presence of subgaleal drains, nor type of skin closure or dressing influenced outcome. Curved incisions, larger craniotomy, and tumor size, however, were associated with an increase in early CSF or hematoma collection (p < 0.0001, p = 0.001, p < 0.01 resp.), and larger craniotomy size was associated with longer persistence of subgaleal fluid collections (p < 0.05). Conclusions Based on our setting, individual surgical nuances such as the type of dural closure and the use of subgaleal drains resulted in a comparable complication rate and outcome. Subgaleal fluid collections were frequently observed after supratentorial procedures, irrespective of the closing technique employed, and resolve spontaneously in the majority of cases without significant sequelae. Our results are limited due to the observational nature in our single-center study and need to be validated by supportive prospective randomized design. Y1 - 2020 U6 - https://doi.org/10.1007/s00701-019-04196-6 SN - 0942-0940 VL - 2020 IS - 162 SP - 729 EP - 736 PB - Springer Nature CY - Cham ER - TY - JOUR A1 - Laarmann, Lukas A1 - Thoma, Andreas A1 - Misch, Philipp A1 - Röth, Thilo A1 - Braun, Carsten A1 - Watkins, Simon A1 - Fard, Mohammad T1 - Automotive safety approach for future eVTOL vehicles JF - CEAS Aeronautical Journal N2 - The eVTOL industry is a rapidly growing mass market expected to start in 2024. eVTOL compete, caused by their predicted missions, with ground-based transportation modes, including mainly passenger cars. Therefore, the automotive and classical aircraft design process is reviewed and compared to highlight advantages for eVTOL development. A special focus is on ergonomic comfort and safety. The need for further investigation of eVTOL’s crashworthiness is outlined by, first, specifying the relevance of passive safety via accident statistics and customer perception analysis; second, comparing the current state of regulation and certification; and third, discussing the advantages of integral safety and applying the automotive safety approach for eVTOL development. Integral safety links active and passive safety, while the automotive safety approach means implementing standardized mandatory full-vehicle crash tests for future eVTOL. Subsequently, possible crash impact conditions are analyzed, and three full-vehicle crash load cases are presented. KW - eVTOL development KW - eVTOL safety KW - Crashworthiness KW - Automotive safety approach KW - Full-vehicle crash test Y1 - 2023 U6 - https://doi.org/10.1007/s13272-023-00655-0 SN - 1869-5590 (Online) SN - 1869-5582 (Print) N1 - Corresponding author: Lukas Laarmann PB - Springer Nature ER - TY - JOUR A1 - Temiz Artmann, Aysegül A1 - Kurulgan demirci, Eylem A1 - Fırat, Ipek Seda A1 - Oflaz, Hakan A1 - Artmann, Gerhard T1 - Recombinant activated protein C (rhAPC) affects lipopolysaccharide-induced mechanical compliance changes and beat frequency of mESC-derived cardiomyocyte monolayers JF - SHOCK KW - Septic cardiomyopathy KW - LPS KW - cardiomyocyte biomechanics KW - CellDrum KW - actin cytoskeleton Y1 - 2021 U6 - https://doi.org/10.1097/SHK.0000000000001845 SN - 1540-0514 PB - Wolters Kluwer CY - Köln ER - TY - JOUR A1 - Bergmann, Ole A1 - Götten, Falk A1 - Braun, Carsten A1 - Janser, Frank T1 - Comparison and evaluation of blade element methods against RANS simulations and test data JF - CEAS Aeronautical Journal N2 - This paper compares several blade element theory (BET) method-based propeller simulation tools, including an evaluation against static propeller ground tests and high-fidelity Reynolds-Average Navier Stokes (RANS) simulations. Two proprietary propeller geometries for paraglider applications are analysed in static and flight conditions. The RANS simulations are validated with the static test data and used as a reference for comparing the BET in flight conditions. The comparison includes the analysis of varying 2D aerodynamic airfoil parameters and different induced velocity calculation methods. The evaluation of the BET propeller simulation tools shows the strength of the BET tools compared to RANS simulations. The RANS simulations underpredict static experimental data within 10% relative error, while appropriate BET tools overpredict the RANS results by 15–20% relative error. A variation in 2D aerodynamic data depicts the need for highly accurate 2D data for accurate BET results. The nonlinear BET coupled with XFOIL for the 2D aerodynamic data matches best with RANS in static operation and flight conditions. The novel BET tool PropCODE combines both approaches and offers further correction models for highly accurate static and flight condition results. KW - BET KW - CFD propeller simulation KW - Propeller aerodynamics KW - Actuator disk modelling KW - Propeller performance Y1 - 2022 U6 - https://doi.org/10.1007/s13272-022-00579-1 SN - 1869-5590 (Online) SN - 1869-5582 (Print) N1 - Corresponding author: Ole Bergmann VL - 13 SP - 535 EP - 557 PB - Springer CY - Wien ER - TY - JOUR A1 - Bialonski, Stephan A1 - Caron, David A. A1 - Schloen, Julia A1 - Feudel, Ulrike A1 - Kantz, Holger A1 - Moorthi, Stefanie D. T1 - Phytoplankton dynamics in the Southern California Bight indicate a complex mixture of transport and biology JF - Journal of Plankton Research N2 - The stimulation and dominance of potentially harmful phytoplankton taxa at a given locale and time are determined by local environmental conditions as well as by transport to or from neighboring regions. The present study investigated the occurrence of common harmful algal bloom (HAB) taxa within the Southern California Bight, using cross-correlation functions to determine potential dependencies between HAB taxa and environmental factors, and potential links to algal transport via local hydrography and currents. A simulation study, in which Lagrangian particles were released, was used to assess travel times due to advection by prevailing ocean currents in the bight. Our results indicate that transport of some taxa may be an important mechanism for the expansion of their distributions into other regions, which was supported by mean travel times derived from our simulation study and other literature on ocean currents in the Southern California Bight. In other cases, however, phytoplankton dynamics were rather linked to local environmental conditions, including coastal upwelling events. Overall, our study shows that complex current patterns in the Southern California Bight may contribute significantly to the formation and expansion of HABs in addition to local environmental factors determining the spatiotemporal dynamics of phytoplankton blooms. Y1 - 2016 U6 - https://doi.org/10.1093/plankt/fbv122 SN - 1464-3774 VL - 38 IS - 4 SP - 1077 EP - 1091 PB - Oxford University Press CY - Oxford ER - TY - JOUR A1 - Thomessen, Karolin A1 - Thoma, Andreas A1 - Braun, Carsten T1 - Bio-inspired altitude changing extension to the 3DVFH* local obstacle avoidance algorithm JF - CEAS Aeronautical Journal N2 - Obstacle avoidance is critical for unmanned aerial vehicles (UAVs) operating autonomously. Obstacle avoidance algorithms either rely on global environment data or local sensor data. Local path planners react to unforeseen objects and plan purely on local sensor information. Similarly, animals need to find feasible paths based on local information about their surroundings. Therefore, their behavior is a valuable source of inspiration for path planning. Bumblebees tend to fly vertically over far-away obstacles and horizontally around close ones, implying two zones for different flight strategies depending on the distance to obstacles. This work enhances the local path planner 3DVFH* with this bio-inspired strategy. The algorithm alters the goal-driven function of the 3DVFH* to climb-preferring if obstacles are far away. Prior experiments with bumblebees led to two definitions of flight zone limits depending on the distance to obstacles, leading to two algorithm variants. Both variants reduce the probability of not reaching the goal of a 3DVFH* implementation in Matlab/Simulink. The best variant, 3DVFH*b-b, reduces this probability from 70.7 to 18.6% in city-like worlds using a strong vertical evasion strategy. Energy consumption is higher, and flight paths are longer compared to the algorithm version with pronounced horizontal evasion tendency. A parameter study analyzes the effect of different weighting factors in the cost function. The best parameter combination shows a failure probability of 6.9% in city-like worlds and reduces energy consumption by 28%. Our findings demonstrate the potential of bio-inspired approaches for improving the performance of local path planning algorithms for UAV. KW - UAV KW - Obstacle avoidance KW - Autonomy KW - Local path planning Y1 - 2023 U6 - https://doi.org/10.1007/s13272-023-00691-w SN - 1869-5590 (Online) SN - 1869-5582 (Print) N1 - Corresponding author: Karolin Thomessen PB - Springer CY - Wien ER - TY - JOUR A1 - Möhren, Felix A1 - Bergmann, Ole A1 - Janser, Frank A1 - Braun, Carsten T1 - On the influence of elasticity on propeller performance: a parametric study JF - CEAS Aeronautical Journal N2 - The aerodynamic performance of propellers strongly depends on their geometry and, consequently, on aeroelastic deformations. Knowledge of the extent of the impact is crucial for overall aircraft performance. An integrated simulation environment for steady aeroelastic propeller simulations is presented. The simulation environment is applied to determine the impact of elastic deformations on the aerodynamic propeller performance. The aerodynamic module includes a blade element momentum approach to calculate aerodynamic loads. The structural module is based on finite beam elements, according to Timoshenko theory, including moderate deflections. Several fixed-pitch propellers with thin-walled cross sections made of both isotropic and non-isotropic materials are investigated. The essential parameters are varied: diameter, disc loading, sweep, material, rotational, and flight velocity. The relative change of thrust between rigid and elastic blades quantifies the impact of propeller elasticity. Swept propellers of large diameters or low disc loadings can decrease the thrust significantly. High flight velocities and low material stiffness amplify this tendency. Performance calculations without consideration of propeller elasticity can lead to decreased efficiency. To avoid cost- and time-intense redesigns, propeller elasticity should be considered for swept planforms and low disc loadings. KW - Propeller KW - Finite element method KW - Blade element method KW - Propeller elasticity KW - Aeroelasticity Y1 - 2023 U6 - https://doi.org/10.1007/s13272-023-00649-y SN - 1869-5590 (Online) SN - 1869-5582 (Print) N1 - Corresponding author: Felix Möhren VL - 14 SP - 311 EP - 323 PB - Springer Nature CY - Berlin ER - TY - JOUR A1 - Thoma, Andreas A1 - Gardi, Alessandro A1 - Fisher, Alex A1 - Braun, Carsten T1 - Improving local path planning for UAV flight in challenging environments by refining cost function weights JF - CEAS Aeronautical Journal N2 - Unmanned Aerial Vehicles (UAV) constantly gain in versatility. However, more reliable path planning algorithms are required until full autonomous UAV operation is possible. This work investigates the algorithm 3DVFH* and analyses its dependency on its cost function weights in 2400 environments. The analysis shows that the 3DVFH* can find a suitable path in every environment. However, a particular type of environment requires a specific choice of cost function weights. For minimal failure, probability interdependencies between the weights of the cost function have to be considered. This dependency reduces the number of control parameters and simplifies the usage of the 3DVFH*. Weights for costs associated with vertical evasion (pitch cost) and vicinity to obstacles (obstacle cost) have the highest influence on the failure probability of the local path planner. Environments with mainly very tall buildings (like large American city centres) require a preference for horizontal avoidance manoeuvres (achieved with high pitch cost weights). In contrast, environments with medium-to-low buildings (like European city centres) benefit from vertical avoidance manoeuvres (achieved with low pitch cost weights). The cost of the vicinity to obstacles also plays an essential role and must be chosen adequately for the environment. Choosing these two weights ideal is sufficient to reduce the failure probability below 10%. KW - Bio-inspired systems KW - Path planning KW - Obstacle avoidance KW - Unmanned aerial vehicles Y1 - 2024 U6 - https://doi.org/10.1007/s13272-024-00741-x SN - 1869-5590 (eISSN) SN - 1869-5582 N1 - Corresponding author: Andreas Thoma PB - Springer CY - Wien ER - TY - JOUR A1 - Pogorelova, Natalia A1 - Rogachev, Evgeniy A1 - Akimbekov, Nuraly S. A1 - Digel, Ilya T1 - Effect of dehydration method on the micro- and nanomorphological properties of bacterial cellulose produced by Medusomyces gisevii on different substrates JF - Journal of materials science N2 - Many important properties of bacterial cellulose (BC), such as moisture absorption capacity, elasticity and tensile strength, largely depend on its structure. This paper presents a study on the effect of the drying method on BC films produced by Medusomyces gisevii using two different procedures: room temperature drying (RT, (24 ± 2 °C, humidity 65 ± 1%, dried until a constant weight was reached) and freeze-drying (FD, treated at − 75 °C for 48 h). BC was synthesized using one of two different carbon sources—either glucose or sucrose. Structural differences in the obtained BC films were evaluated using atomic force microscopy (AFM), scanning electron microscopy (SEM), and X-ray diffraction. Macroscopically, the RT samples appeared semi-transparent and smooth, whereas the FD group exhibited an opaque white color and sponge-like structure. SEM examination showed denser packing of fibrils in FD samples while RT-samples displayed smaller average fiber diameter, lower surface roughness and less porosity. AFM confirmed the SEM observations and showed that the FD material exhibited a more branched structure and a higher surface roughness. The samples cultivated in a glucose-containing nutrient medium, generally displayed a straight and ordered shape of fibrils compared to the sucrose-derived BC, characterized by a rougher and wavier structure. The BC films dried under different conditions showed distinctly different crystallinity degrees, whereas the carbon source in the culture medium was found to have a relatively small effect on the BC crystallinity. Y1 - 2024 U6 - https://doi.org/10.1007/s10853-024-09596-3 SN - 1573-4803 (Online) SN - 0022-2461 (Print) N1 - Corresponding author: Ilya Digel VL - 2024 PB - Springer Science + Business Media CY - Dordrecht ER - TY - JOUR A1 - Rossi, Leonardo A1 - Stupazzini, Marco A1 - Parisi, Davide A1 - Holtschoppen, Britta A1 - Ruggieri, Gabriella A1 - Butenweg, Christoph T1 - Empirical fragility functions and loss curves for long-span-beam buildings based on the 2012 Emilia-Romagna earthquake official database JF - Bulletin of Earthquake Engineering N2 - The 2012 Emilia-Romagna earthquake, that mainly struck the homonymous Italian region provoking 28 casualties and damage to thousands of structures and infrastructures, is an exceptional source of information to question, investigate, and challenge the validity of seismic fragility functions and loss curves from an empirical standpoint. Among the most recent seismic events taking place in Europe, that of Emilia-Romagna is quite likely one of the best documented, not only in terms of experienced damages, but also for what concerns occurred losses and necessary reconstruction costs. In fact, in order to manage the compensations in a fair way both to citizens and business owners, soon after the seismic sequence, the regional administrative authority started (1) collecting damage and consequence-related data, (2) evaluating information sources and (3) taking care of the cross-checking of various reports. A specific database—so-called Sistema Informativo Gestione Europa (SFINGE)—was devoted to damaged business activities. As a result, 7 years after the seismic events, scientists can rely on a one-of-a-kind, vast and consistent database, containing information about (among other things): (1) buildings’ location and dimensions, (2) occurred structural damages, (3) experienced direct economic losses and (4) related reconstruction costs. The present work is focused on a specific data subset of SFINGE, whose elements are Long-Span-Beam buildings (mostly precast) deployed for business activities in industry, trade or agriculture. With the available set of data, empirical fragility functions, cost and loss ratio curves are elaborated, that may be included within existing Performance Based Earthquake Engineering assessment toolkits. KW - Empirical fragility functions KW - Empirical consequence curves KW - Precast buildings KW - Emilia-Romagna earthquake KW - PBEE Y1 - 2019 U6 - https://doi.org/10.1007/s10518-019-00759-1 SN - 1573-1456 VL - 18 SP - 1693 EP - 1721 PB - Springer Nature ER - TY - JOUR A1 - Tippkötter, Nils A1 - Roth, Jasmine T1 - Purified Butanol from Lignocellulose – Solvent‐Impregnated Resins for an Integrated Selective Removal JF - Chemie Ingenieur Technik N2 - In traditional microbial biobutanol production, the solvent must be recovered during fermentation process for a sufficient space-time yield. Thermal separation is not feasible due to the boiling point of n-butanol. As an integrated and selective solid-liquid separation alternative, solvent impregnated resins (SIRs) were applied. Two polymeric resins were evaluated and an extractant screening was conducted. Vacuum application with vapor collection in fixed-bed column as bioreactor bypass was successfully implemented as butanol desorption step. In course of further increasing process economics, fermentation with renewable lignocellulosic substrates was conducted using Clostridium acetobutylicum. Utilization of SIR was shown to be a potential strategy for solvent removal from fermentation broth, while application of a bypass column allows for product removal and recovery at once. KW - Biofuel KW - Biorefinery KW - Butanol KW - Clostridium acetobutylicum KW - Lignocellulose Y1 - 2020 U6 - https://doi.org/10.1002/cite.202000200 SN - 1522-2640 N1 - Corresponding author: Nils Tippkötter VL - 92 IS - 11 SP - 1741 EP - 1751 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Jablonski, Melanie A1 - Poghossian, Arshak A1 - Keusgen, Michael A1 - Wege, Christina A1 - Schöning, Michael Josef T1 - Detection of plant virus particles with a capacitive field-effect sensor JF - Analytical and Bioanalytical Chemistry N2 - Plant viruses are major contributors to crop losses and induce high economic costs worldwide. For reliable, on-site and early detection of plant viral diseases, portable biosensors are of great interest. In this study, a field-effect SiO2-gate electrolyte-insulator-semiconductor (EIS) sensor was utilized for the label-free electrostatic detection of tobacco mosaic virus (TMV) particles as a model plant pathogen. The capacitive EIS sensor has been characterized regarding its TMV sensitivity by means of constant-capacitance method. The EIS sensor was able to detect biotinylated TMV particles from a solution with a TMV concentration as low as 0.025 nM. A good correlation between the registered EIS sensor signal and the density of adsorbed TMV particles assessed from scanning electron microscopy images of the SiO2-gate chip surface was observed. Additionally, the isoelectric point of the biotinylated TMV particles was determined via zeta potential measurements and the influence of ionic strength of the measurement solution on the TMV-modified EIS sensor signal has been studied. KW - Plant virus KW - Capacitive field-effect sensor KW - Tobacco mosaic virus (TMV) KW - Label-free detection KW - Zeta potential Y1 - 2021 U6 - https://doi.org/10.1007/s00216-021-03448-8 SN - 1618-2650 N1 - Corresponding authors: Arshak Poghossian & Michael J. Schöning VL - 413 SP - 5669 EP - 5678 PB - Springer Nature CY - Cham ER - TY - JOUR A1 - Sattler, Johannes Christoph A1 - Röger, Marc A1 - Schwarzbözl, Peter A1 - Buck, Reiner A1 - Macke, Ansgar A1 - Raeder, Christian A1 - Göttsche, Joachim T1 - Review of heliostat calibration and tracking control methods JF - Solar Energy N2 - Large scale central receiver systems typically deploy between thousands to more than a hundred thousand heliostats. During solar operation, each heliostat is aligned individually in such a way that the overall surface normal bisects the angle between the sun’s position and the aim point coordinate on the receiver. Due to various tracking error sources, achieving accurate alignment ≤1 mrad for all the heliostats with respect to the aim points on the receiver without a calibration system can be regarded as unrealistic. Therefore, a calibration system is necessary not only to improve the aiming accuracy for achieving desired flux distributions but also to reduce or eliminate spillage. An overview of current larger-scale central receiver systems (CRS), tracking error sources and the basic requirements of an ideal calibration system is presented. Leading up to the main topic, a description of general and specific terms on the topics heliostat calibration and tracking control clarifies the terminology used in this work. Various figures illustrate the signal flows along various typical components as well as the corresponding monitoring or measuring devices that indicate or measure along the signal (or effect) chain. The numerous calibration systems are described in detail and classified in groups. Two tables allow the juxtaposition of the calibration methods for a better comparison. In an assessment, the advantages and disadvantages of individual calibration methods are presented. Y1 - 2020 U6 - https://doi.org/10.1016/j.solener.2020.06.030 VL - 207 SP - 110 EP - 132 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Finger, Felix A1 - Götten, Falk A1 - Braun, Carsten A1 - Bil, Cees T1 - Mass, primary energy, and cost: the impact of optimization objectives on the initial sizing of hybrid-electric general aviation aircraft JF - CEAS Aeronautical Journal N2 - For short take-off and landing (STOL) aircraft, a parallel hybrid-electric propulsion system potentially offers superior performance compared to a conventional propulsion system, because the short-take-off power requirement is much higher than the cruise power requirement. This power-matching problem can be solved with a balanced hybrid propulsion system. However, there is a trade-off between wing loading, power loading, the level of hybridization, as well as range and take-off distance. An optimization method can vary design variables in such a way that a minimum of a particular objective is attained. In this paper, a comparison between the optimization results for minimum mass, minimum consumed primary energy, and minimum cost is conducted. A new initial sizing algorithm for general aviation aircraft with hybrid-electric propulsion systems is applied. This initial sizing methodology covers point performance, mission performance analysis, the weight estimation process, and cost estimation. The methodology is applied to the design of a STOL general aviation aircraft, intended for on-demand air mobility operations. The aircraft is sized to carry eight passengers over a distance of 500 km, while able to take off and land from short airstrips. Results indicate that parallel hybrid-electric propulsion systems must be considered for future STOL aircraft. Y1 - 2020 U6 - https://doi.org/10.1007/s13272-020-00449-8 SN - 1869-5590 N1 - Corresponding author: Felix Finger VL - 2020 IS - 11 SP - 713 EP - 730 PB - Springer CY - Heidelberg ER - TY - JOUR A1 - Molinnus, Denise A1 - Iken, Heiko A1 - Johnen, Anna Lynn A1 - Richstein, Benjamin A1 - Hellmich, Lena A1 - Poghossian, Arshak A1 - Knoch, Joachim A1 - Schöning, Michael Josef T1 - Miniaturized pH-Sensitive Field-Effect Capacitors with Ultrathin Ta₂O₅ Films Prepared by Atomic Layer Deposition JF - physica status solidi (a) applications and materials science N2 - Miniaturized electrolyte–insulator–semiconductor capacitors (EISCAPs) with ultrathin gate insulators have been studied in terms of their pH-sensitive sensor characteristics: three different EISCAP systems consisting of Al–p-Si–Ta2O5(5 nm), Al–p-Si–Si3N4(1 or 2 nm)–Ta2O5 (5 nm), and Al–p-Si–SiO2(3.6 nm)–Ta2O5(5 nm) layer structures are characterized in buffer solution with different pH values by means of capacitance–voltage and constant capacitance method. The SiO2 and Si3N4 gate insulators are deposited by rapid thermal oxidation and rapid thermal nitridation, respectively, whereas the Ta2O5 film is prepared by atomic layer deposition. All EISCAP systems have a clear pH response, favoring the stacked gate insulators SiO2–Ta2O5 when considering the overall sensor characteristics, while the Si3N4(1 nm)–Ta2O5 stack delivers the largest accumulation capacitance (due to the lower equivalent oxide thickness) and a higher steepness in the slope of the capacitance–voltage curve among the studied stacked gate insulator systems. KW - atomic layer deposition KW - capacitive field-effect sensors KW - pH sensors KW - ultrathin gate insulators Y1 - 2022 U6 - https://doi.org/10.1002/pssa.202100660 SN - 1862-6319 N1 - Corresponding author: Michael J. Schöning VL - 219 IS - 8 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Hammer, Thorben A1 - Quitter, Julius A1 - Mayntz, Joscha A1 - Bauschat, J.-Michael A1 - Dahmann, Peter A1 - Götten, Falk A1 - Hille, Sebastian A1 - Stumpf, Eike T1 - Free fall drag estimation of small-scale multirotor unmanned aircraft systems using computational fluid dynamics and wind tunnel experiments JF - CEAS Aeronautical Journal N2 - New European Union (EU) regulations for UAS operations require an operational risk analysis, which includes an estimation of the potential danger of the UAS crashing. A key parameter for the potential ground risk is the kinetic impact energy of the UAS. The kinetic energy depends on the impact velocity of the UAS and, therefore, on the aerodynamic drag and the weight during free fall. Hence, estimating the impact energy of a UAS requires an accurate drag estimation of the UAS in that state. The paper at hand presents the aerodynamic drag estimation of small-scale multirotor UAS. Multirotor UAS of various sizes and configurations were analysed with a fully unsteady Reynolds-averaged Navier–Stokes approach. These simulations included different velocities and various fuselage pitch angles of the UAS. The results were compared against force measurements performed in a subsonic wind tunnel and provided good consistency. Furthermore, the influence of the UAS`s fuselage pitch angle as well as the influence of fixed and free spinning propellers on the aerodynamic drag was analysed. Free spinning propellers may increase the drag by up to 110%, depending on the fuselage pitch angle. Increasing the fuselage pitch angle of the UAS lowers the drag by 40% up to 85%, depending on the UAS. The data presented in this paper allow for increased accuracy of ground risk assessments. KW - Multirotor UAS KW - Drag estimation KW - CFD KW - Wind tunnel experiments KW - Wind milling Y1 - 2023 U6 - https://doi.org/10.1007/s13272-023-00702-w SN - 1869-5590 (Online) SN - 1869-5582 (Print) N1 - Corresponding author: Thorben Hammer PB - Springer CY - Wien ER - TY - JOUR A1 - Harzheim, Thomas A1 - Mühmel, Marc A1 - Heuermann, Holger T1 - A SFCW harmonic radar system for maritime search and rescue using passive and active tags JF - International Journal of Microwave and Wireless Technologies N2 - This paper introduces a new maritime search and rescue system based on S-band illumination harmonic radar (HR). Passive and active tags have been developed and tested while attached to life jackets and a small boat. In this demonstration test carried out on the Baltic Sea, the system was able to detect and range the active tags up to a distance of 5800 m using an illumination signal transmit-power of 100 W. Special attention is given to the development, performance, and conceptual differences between passive and active tags used in the system. Guidelines for achieving a high HR dynamic range, including a system components description, are given and a comparison with other HR systems is performed. System integration with a commercial maritime X-band navigation radar is shown to demonstrate a solution for rapid search and rescue response and quick localization. KW - Radar KW - microwave measurements KW - harmonic radar KW - harmonic radar tags KW - nonlinear VNA measurements Y1 - 2021 U6 - https://doi.org/10.1017/S1759078721000520 VL - 13 IS - Special Issue 7 SP - 691 EP - 707 PB - Cambridge University Press CY - Cambridge ER - TY - JOUR A1 - Janus, Kevin Alexander A1 - Achtsnicht, Stefan A1 - Drinic, Aleksander A1 - Kopp, Alexander A1 - Keusgen, Michael A1 - Schöning, Michael Josef T1 - Transient magnesium-based thin-film temperature sensor on a flexible, bioabsorbable substrate for future medical applications JF - Applied Research N2 - In this work, the bioabsorbable materials, namely fibroin, polylactide acid (PLA), magnesium and magnesium oxide are investigated for their application as transient, resistive temperature detectors (RTD). For this purpose, a thin-film magnesium-based meander-like electrode is deposited onto a flexible, bioabsorbable substrate (fibroin or PLA) and encapsulated (passivated) by additional magnesium oxide layers on top and below the magnesium-based electrode. The morphology of different layered RTDs is analyzed by scanning electron microscopy. The sensor performance and lifetime of the RTD is characterized both under ambient atmospheric conditions between 30°C and 43°C, and wet tissue-like conditions with a constant temperature regime of 37°C. The latter triggers the degradation process of the magnesium-based layers. The 3-layers RTDs on a PLA substrate could achieve a lifetime of 8.5 h. These sensors also show the best sensor performance under ambient atmospheric conditions with a mean sensitivity of 0.48 Ω/°C ± 0.01 Ω/°C. KW - Silk fibroin KW - Polylactide acid KW - Bioabsorbable KW - Resistive temperature detector Y1 - 2023 U6 - https://doi.org/10.1002/appl.202300102 SN - 2702-4288 (Print) N1 - Corresponding author: Michael Josef Schöning IS - Accepted manuscript PB - Wiley-VCH ER - TY - JOUR A1 - Janus, Kevin Alexander A1 - Achtsnicht, Stefan A1 - Tempel, Laura A1 - Drinic, Aleksaner A1 - Kopp, Alexander A1 - Keusgen, Michael A1 - Schöning, Michael Josef T1 - Influence of fibroin membrane composition and curing parameters on the performance of a biodegradable enzymatic biosensor manufactured from Silicon-Free Carbon JF - Physica status solidi : pss. A, Applications and materials science N2 - Herein, fibroin, polylactide (PLA), and carbon are investigated for their suitability as biocompatible and biodegradable materials for amperometric biosensors. For this purpose, screen-printed carbon electrodes on the biodegradable substrates fibroin and PLA are modified with a glucose oxidase membrane and then encapsulated with the biocompatible material Ecoflex. The influence of different curing parameters of the carbon electrodes on the resulting biosensor characteristics is studied. The morphology of the electrodes is investigated by scanning electron microscopy, and the biosensor performance is examined by amperometric measurements of glucose (0.5–10 mM) in phosphate buffer solution, pH 7.4, at an applied potential of 1.2 V versus a Ag/AgCl reference electrode. Instead of Ecoflex, fibroin, PLA, and wound adhesive are tested as alternative encapsulation compounds: a series of swelling tests with different fibroin compositions, PLA, and Ecoflex has been performed before characterizing the most promising candidates by chronoamperometry. Therefore, the carbon electrodes are completely covered with the particular encapsulation material. Chronoamperometric measurements with H2O2 concentrations between 0.5 and 10 mM enable studying the leakage current behavior. KW - amperometric biosensors KW - biocompatible KW - biodegradabl KW - encapsulation materials KW - fibroin Y1 - 2023 U6 - https://doi.org/10.1002/pssa.202300081 SN - 1862-6300 (Print) SN - 1862-6319 (Online) N1 - Corresponding author: Michael J. Schöning VL - 220 IS - 22 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Karschuck, Tobias A1 - Poghossian, Arshak A1 - Ser, Joey A1 - Tsokolakyan, Astghik A1 - Achtsnicht, Stefan A1 - Wagner, Patrick A1 - Schöning, Michael Josef T1 - Capacitive model of enzyme-modified field-effect biosensors: Impact of enzyme coverage JF - Sensors and Actuators B: Chemical N2 - Electrolyte-insulator-semiconductor capacitors (EISCAP) belong to field-effect sensors having an attractive transducer architecture for constructing various biochemical sensors. In this study, a capacitive model of enzyme-modified EISCAPs has been developed and the impact of the surface coverage of immobilized enzymes on its capacitance-voltage and constant-capacitance characteristics was studied theoretically and experimentally. The used multicell arrangement enables a multiplexed electrochemical characterization of up to sixteen EISCAPs. Different enzyme coverages have been achieved by means of parallel electrical connection of bare and enzyme-covered single EISCAPs in diverse combinations. As predicted by the model, with increasing the enzyme coverage, both the shift of capacitance-voltage curves and the amplitude of the constant-capacitance signal increase, resulting in an enhancement of analyte sensitivity of the EISCAP biosensor. In addition, the capability of the multicell arrangement with multi-enzyme covered EISCAPs for sequentially detecting multianalytes (penicillin and urea) utilizing the enzymes penicillinase and urease has been experimentally demonstrated and discussed. KW - Field-effect biosensor KW - Capacitive model KW - Enzyme coverage KW - Multianalyte detection KW - Penicillin Y1 - 2024 U6 - https://doi.org/10.1016/j.snb.2024.135530 SN - 0925-4005 (Print) SN - 1873-3077 (Online) N1 - Corresponding Author: Michael J. Schöning VL - 408 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Molinnus, Denise A1 - Janus, Kevin Alexander A1 - Fang, Anyelina C. A1 - Drinic, Aleksander A1 - Achtsnicht, Stefan A1 - Köpf, Marius A1 - Keusgen, Michael A1 - Schöning, Michael Josef T1 - Thick-film carbon electrode deposited onto a biodegradable fibroin substrate for biosensing applications JF - Physica status solidi (a) N2 - This study addresses a proof-of-concept experiment with a biocompatible screen-printed carbon electrode deposited onto a biocompatible and biodegradable substrate, which is made of fibroin, a protein derived from silk of the Bombyx mori silkworm. To demonstrate the sensor performance, the carbon electrode is functionalized as a glucose biosensor with the enzyme glucose oxidase and encapsulated with a silicone rubber to ensure biocompatibility of the contact wires. The carbon electrode is fabricated by means of thick-film technology including a curing step to solidify the carbon paste. The influence of the curing temperature and curing time on the electrode morphology is analyzed via scanning electron microscopy. The electrochemical characterization of the glucose biosensor is performed by amperometric/voltammetric measurements of different glucose concentrations in phosphate buffer. Herein, systematic studies at applied potentials from 500 to 1200 mV to the carbon working electrode (vs the Ag/AgCl reference electrode) allow to determine the optimal working potential. Additionally, the influence of the curing parameters on the glucose sensitivity is examined over a time period of up to 361 days. The sensor shows a negligible cross-sensitivity toward ascorbic acid, noradrenaline, and adrenaline. The developed biocompatible biosensor is highly promising for future in vivo and epidermal applications. KW - biocompatible materials KW - biodegradable electronic devices KW - biosensors KW - carbon electrodes KW - glucose Y1 - 2022 U6 - https://doi.org/10.1002/pssa.202200100 SN - 1862-6319 N1 - Corresponding author: Michael J. Schöning VL - 219 IS - 23 SP - 1 EP - 9 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Adels, Klaudia A1 - Elbers, Gereon A1 - Diehl, Bernd A1 - Monakhova, Yulia T1 - Multicomponent analysis of dietary supplements containing glucosamine and chondroitin: comparative low- and high-field NMR spectroscopic study JF - Analytical Sciences N2 - With the prevalence of glucosamine- and chondroitin-containing dietary supplements for people with osteoarthritis in the marketplace, it is important to have an accurate and reproducible analytical method for the quantitation of these compounds in finished products. NMR spectroscopic method based both on low- (80 MHz) and high- (500–600 MHz) field NMR instrumentation was established, compared and validated for the determination of chondroitin sulfate and glucosamine in dietary supplements. The proposed method was applied for analysis of 20 different dietary supplements. In the majority of cases, quantification results obtained on the low-field NMR spectrometer are similar to those obtained with high-field 500–600 MHz NMR devices. Validation results in terms of accuracy, precision, reproducibility, limit of detection and recovery demonstrated that the developed method is fit for purpose for the marketed products. The NMR method was extended to the analysis of methylsulfonylmethane, adulterant maltodextrin, acetate and inorganic ions. Low-field NMR can be a quicker and cheaper alternative to more expensive high-field NMR measurements for quality control of the investigated dietary supplements. High-field NMR instrumentation can be more favorable for samples with complex composition due to better resolution, simultaneously giving the possibility of analysis of inorganic species such as potassium and chloride. KW - Glucosamine KW - Chondroitin sulfate KW - Polysaccharides KW - Dietary supplements KW - High-field NMR Y1 - 2023 U6 - https://doi.org/10.1007/s44211-023-00433-2 SN - 1348-2246 (Online) SN - 0910-6340 (Print) N1 - Corresponding author: Yulia Monakhova VL - 2023 PB - Springer Verlag CY - Cham ER - TY - JOUR A1 - Monakhova, Yulia A1 - Diehl, Bernd W. K. T1 - A step towards optimization of the qNMR workflow: proficiency testing exercise at an GxP-accredited laboratory JF - Applied Magnetic Resonance N2 - Quantitative nuclear magnetic resonance (qNMR) is considered as a powerful tool for multicomponent mixture analysis as well as for the purity determination of single compounds. Special attention is currently paid to the training of operators and study directors involved in qNMR testing. To assure that only qualified personnel are used for sample preparation at our GxP-accredited laboratory, weighing test was proposed. Sixteen participants performed six-fold weighing of the binary mixture of dibutylated hydroxytoluene (BHT) and 1,2,4,5-tetrachloro-3-nitrobenzene (TCNB). To evaluate the quality of data analysis, all spectra were evaluated manually by a qNMR expert and using in-house developed automated routine. The results revealed that mean values are comparable and both evaluation approaches are free of systematic error. However, automated evaluation resulted in an approximately 20% increase in precision. The same findings were revealed for qNMR analysis of 32 compounds used in pharmaceutical industry. Weighing test by six-fold determination in binary mixtures and automated qNMR methodology can be recommended as efficient tools for evaluating staff proficiency. The automated qNMR method significantly increases throughput and precision of qNMR for routine measurements and extends application scope of qNMR. Y1 - 2021 U6 - https://doi.org/10.1007/s00723-021-01324-3 SN - 1613-7507 N1 - Corresponding author: Yulia Monakhova VL - 52 SP - 581 EP - 593 PB - Springer Nature CY - Wien ER - TY - JOUR A1 - Falkenberg, Fabian A1 - Voß, Leonie A1 - Bott, Michael A1 - Bongaerts, Johannes A1 - Siegert, Petra T1 - New robust subtilisins from halotolerant and halophilic Bacillaceae JF - Applied Microbiology and Biotechnology N2 - The aim of the present study was the characterisation of three true subtilisins and one phylogenetically intermediate subtilisin from halotolerant and halophilic microorganisms. Considering the currently growing enzyme market for efficient and novel biocatalysts, data mining is a promising source for novel, as yet uncharacterised enzymes, especially from halophilic or halotolerant Bacillaceae, which offer great potential to meet industrial needs. Both halophilic bacteria Pontibacillus marinus DSM 16465ᵀ and Alkalibacillus haloalkaliphilus DSM 5271ᵀ and both halotolerant bacteria Metabacillus indicus DSM 16189 and Litchfieldia alkalitelluris DSM 16976ᵀ served as a source for the four new subtilisins SPPM, SPAH, SPMI and SPLA. The protease genes were cloned and expressed in Bacillus subtilis DB104. Purification to apparent homogeneity was achieved by ethanol precipitation, desalting and ion-exchange chromatography. Enzyme activity could be observed between pH 5.0–12.0 with an optimum for SPPM, SPMI and SPLA around pH 9.0 and for SPAH at pH 10.0. The optimal temperature for SPMI and SPLA was 70 °C and for SPPM and SPAH 55 °C and 50 °C, respectively. All proteases showed high stability towards 5% (w/v) SDS and were active even at NaCl concentrations of 5 M. The four proteases demonstrate potential for future biotechnological applications. KW - Biotechnological application KW - Bacillaceae KW - Subtilisin KW - Subtilases KW - Halotolerant protease Y1 - 2023 U6 - https://doi.org/10.1007/s00253-023-12553-w SN - 1432-0614 N1 - Corresponding author: Petra Siegert VL - 107 SP - 3939 EP - 3954 PB - Springer Nature CY - Berlin ER - TY - JOUR A1 - Dikta, Gerhard A1 - Reißel, Martin A1 - Harlaß, Carsten T1 - Semi-parametric survival function estimators deduced from an identifying Volterra type integral equation JF - Journal of multivariate analysis N2 - Based on an identifying Volterra type integral equation for randomly right censored observations from a lifetime distribution function F, we solve the corresponding estimating equation by an explicit and implicit Euler scheme. While the first approach results in some known estimators, the second one produces new semi-parametric and pre-smoothed Kaplan–Meier estimators which are real distribution functions rather than sub-distribution functions as the former ones are. This property of the new estimators is particular useful if one wants to estimate the expected lifetime restricted to the support of the observation time. Specifically, we focus on estimation under the semi-parametric random censorship model (SRCM), that is, a random censorship model where the conditional expectation of the censoring indicator given the observation belongs to a parametric family. We show that some estimated linear functionals which are based on the new semi-parametric estimator are strong consistent, asymptotically normal, and efficient under SRCM. In a small simulation study, the performance of the new estimator is illustrated under moderate sample sizes. Finally, we apply the new estimator to a well-known real dataset. KW - Volterra integral equation KW - Product-integration KW - Asymptotic efficiency KW - Semi-parametric random censorship model KW - Censored data KW - Survival analysis Y1 - 2016 U6 - https://doi.org/10.1016/j.jmva.2016.02.008 IS - 147 SP - 273 EP - 284 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Finger, Felix A1 - Braun, Carsten A1 - Bil, Cees T1 - Impact of electric propulsion technology and mission requirements on the performance of VTOL UAVs JF - CEAS Aeronautical Journal N2 - One of the engineering challenges in aviation is the design of transitioning vertical take-off and landing (VTOL) aircraft. Thrust-borne flight implies a higher mass fraction of the propulsion system, as well as much increased energy consumption in the take-off and landing phases. This mass increase is typically higher for aircraft with a separate lift propulsion system than for aircraft that use the cruise propulsion system to support a dedicated lift system. However, for a cost–benefit trade study, it is necessary to quantify the impact the VTOL requirement and propulsion configuration has on aircraft mass and size. For this reason, sizing studies are conducted. This paper explores the impact of considering a supplemental electric propulsion system for achieving hovering flight. Key variables in this study, apart from the lift system configuration, are the rotor disk loading and hover flight time, as well as the electrical systems technology level for both batteries and motors. Payload and endurance are typically used as the measures of merit for unmanned aircraft that carry electro-optical sensors, and therefore the analysis focuses on these particular parameters. Y1 - 2018 U6 - https://doi.org/10.1007/s13272-018-0352-x SN - 1869-5582 print SN - 1869-5590 online VL - 10 IS - 3 SP - 843 PB - Springer ER - TY - JOUR A1 - Henderson, Colin J. A1 - Mclaughlin, Lesley A. A1 - Scheer, Nico A1 - Stanley, Lesley A. A1 - Wolf, C. Roland T1 - Cytochrome b5 Is a Major Determinant of Human Cytochrome P450 CYP2D6 and CYP3A4 Activity In Vivo s JF - Molecular Pharmacology Y1 - 2015 U6 - https://doi.org/10.1124/mol.114.097394 SN - 1521-0111 VL - 87 IS - 4 SP - 733 EP - 739 PB - ASPET CY - Bethesda ER -