TY - JOUR A1 - Reißel, Martin A1 - Lustfeld, Hans A1 - Hirschfeld, Julian A. A1 - Steffen, Bernhard T1 - Uniqueness of magnetotomography for fuel cells and fuel cell stacks / Lustfeld, H. ; Hirschfeld, J. ; Reißel, M ; Steffen, B. JF - Journal of Physics A: Mathematical and Theoretical. 42 (2009), H. 495205 Y1 - 2009 SN - 0022-3689 SP - 9 S. ER - TY - JOUR A1 - Reißel, Martin A1 - Lustfeld, Hans A1 - Steffen, Bernhard A1 - Schmidt, U. T1 - Reconstruction of Electric Currents in a Fuel Cell by Magnetic Field Measurements / Lustfeld, H. ; Reißel, M. ; Steffen, B. ; Schmidt, U. JF - Journal of fuel cell science and technology Y1 - 2009 SN - 1550-624X VL - Vol. 6 IS - Iss. 2 SP - 021012-1 EP - 021012-8 ER - TY - JOUR A1 - Reißel, Martin A1 - Hirschfeld, Julian A. A1 - Lustfeld, Hans A1 - Steffen, Bernhard T1 - Magnetotomography and Electric Currents in a Fuel Cell / Lustfeld, H. ; Reißel, M. ; Steffen, B. JF - Fuel Cells. 9 (2009), H. 4 Y1 - 2009 SN - 1615-6854 SP - 474 EP - 481 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Lustfeld, Hans A1 - Hirschfeld, Julian A. A1 - Reißel, Martin A1 - Steffen, Bernhard T1 - Enhancement of precision and reduction of measuring points in tomographic reconstructions JF - Physics Letters A Y1 - 2011 SN - 0375-9601 VL - 375 IS - 8 SP - 1167 EP - 1171 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Schermutzki, Margret ED - Terbuyken, Gregor T1 - In Modulen lehren, lernen und prüfen JF - In Modulen lehren, lernen und prüfen. Herausforderungen an die Hochschuldidaktik Y1 - 2010 SN - 978-3-8172-7809-1 N1 - Dokumentation einer Tagung der Evangelischen Akademie Loccum vom 14. bis 16. Dezember 2009 in Kooperation mit der ZEvA Hannover und der Universität Hannover. SP - 81 EP - 106 PB - Evangelische Akademie Loccum CY - Rehburg-Loccum ER - TY - JOUR A1 - Schneider, Bettina A1 - Schneider, Wilhelm T1 - Die Konzernrechnungslegung JF - Das Wirtschaftsstudium : wisu Y1 - 2010 SN - 0340-3084 VL - 39 IS - 7 SP - 938 EP - 942 PB - Lange CY - Düsseldorf ER - TY - JOUR A1 - Ortner, Marion A1 - Hauser, Christine A1 - Schmaderer, Christoph A1 - Muggenthaler, Claudia A1 - Hapfelmeier, Alexander A1 - Sorg, Christian A1 - Diehl-Schmid, Janine A1 - Kurz, Alexander A1 - Förstl, Hans A1 - Ikenberg, Benno A1 - Kotliar, Konstantin A1 - Holger, Poppert A1 - Grimmer, Timo T1 - Decreased vascular pulsatility in Alzheimer’s disease dementia measured by transcranial color-coded duplex sonography JF - Neuropsychiatric disease and treatment N2 - Purpose: Impaired paravascular drainage of β-Amyloid (Aβ) has been proposed as a contributing cause for sporadic Alzheimer’s disease (AD), as decreased cerebral blood vessel pulsatility and subsequently reduced propulsion in this pathway could lead to the accumulation and deposition of Aβ in the brain. Therefore, we hypothesized that there is an increased impairment in pulsatility across AD spectrum. Patients and Methods: Using transcranial color-coded duplex sonography (TCCS) the resistance and pulsatility index (RI; PI) of the middle cerebral artery (MCA) in healthy controls (HC, n=14) and patients with AD dementia (ADD, n=12) were measured. In a second step, we extended the sample by adding patients with mild cognitive impairment (MCI) stratified by the presence (MCI-AD, n=8) or absence of biomarkers (MCI-nonAD, n=8) indicative for underlying AD pathology, and compared RI and PI across the groups. To control for atherosclerosis as a confounder, we measured the arteriolar-venular-ratio of retinal vessels. Results: Left and right RI (p=0.020; p=0.027) and left PI (p=0.034) differed between HC and ADD controlled for atherosclerosis with AUCs of 0.776, 0.763, and 0.718, respectively. The RI and PI of MCI-AD tended towards ADD, of MCI-nonAD towards HC, respectively. RIs and PIs were associated with disease severity (p=0.010, p=0.023). Conclusion: Our results strengthen the hypothesis that impaired pulsatility could cause impaired amyloid clearance from the brain and thereby might contribute to the development of AD. However, further studies considering other factors possibly influencing amyloid clearance as well as larger sample sizes are needed. Y1 - 2019 U6 - https://doi.org/10.2147/NDT.S225754 SN - 1178-2021 IS - 15 SP - 3487 EP - 3499 PB - Dove Medical Press CY - Albany, Auckland ER - TY - JOUR A1 - Knödler, Matthias A1 - Rühl, Clemens A1 - Emonts, Jessica A1 - Buyel, Johannes Felix T1 - Seasonal weather changes affect the yield and quality of recombinant proteins produced in transgenic tobacco plants in a greenhouse setting JF - Frontiers in Plant Science N2 - Transgenic plants have the potential to produce recombinant proteins on an agricultural scale, with yields of several tons per year. The cost-effectiveness of transgenic plants increases if simple cultivation facilities such as greenhouses can be used for production. In such a setting, we expressed a novel affinity ligand based on the fluorescent protein DsRed, which we used as a carrier for the linear epitope ELDKWA from the HIV-neutralizing antibody 2F5. The DsRed-2F5-epitope (DFE) fusion protein was produced in 12 consecutive batches of transgenic tobacco (Nicotiana tabacum) plants over the course of 2 years and was purified using a combination of blanching and immobilized metal-ion affinity chromatography (IMAC). The average purity after IMAC was 57 ± 26% (n = 24) in terms of total soluble protein, but the average yield of pure DFE (12 mg kg−1) showed substantial variation (± 97 mg kg−1, n = 24) which correlated with seasonal changes. Specifically, we found that temperature peaks (>28°C) and intense illuminance (>45 klx h−1) were associated with lower DFE yields after purification, reflecting the loss of the epitope-containing C-terminus in up to 90% of the product. Whereas the weather factors were of limited use to predict product yields of individual harvests conducted for each batch (spaced by 1 week), the average batch yields were well approximated by simple linear regression models using two independent variables for prediction (illuminance and plant age). Interestingly, accumulation levels determined by fluorescence analysis were not affected by weather conditions but positively correlated with plant age, suggesting that the product was still expressed at high levels, but the extreme conditions affected its stability, albeit still preserving the fluorophore function. The efficient production of intact recombinant proteins in plants may therefore require adequate climate control and shading in greenhouses or even cultivation in fully controlled indoor farms. KW - batch reproducibility KW - environmental correlation KW - fluorescent protein carrier KW - greenhouse cultivation KW - plant molecular farming Y1 - 2019 U6 - https://doi.org/10.3389/fpls.2019.01245 SN - 1664-462X (online-ressource) IS - 10 PB - Frontiers Media CY - Lausanne ER - TY - JOUR A1 - Bandlitz, Stefan A1 - Nakhoul, Makram A1 - Kotliar, Konstantin T1 - Daily variations of corneal white-to-white diameter measured with different methods JF - Clinical and experimental optometry N2 - Purpose: A precise determination of the corneal diameter is essential for the diagnosis of various ocular diseases, cataract and refractive surgery as well as for the selection and fitting of contact lenses. The aim of this study was to investigate the agreement between two automatic and one manual method for corneal diameter determination and to evaluate possible diurnal variations in corneal diameter. Patients and Methods: Horizontal white-to-white corneal diameter of 20 volunteers was measured at three different fixed times of a day with three methods: Scheimpflug method (Pentacam HR, Oculus), placido based topography (Keratograph 5M, Oculus) and manual method using an image analysis software at a slitlamp (BQ900, Haag-Streit). Results: The two-factorial analysis of variance could not show a significant effect of the different instruments (p = 0.117), the different time points (p = 0.506) and the interaction between instrument and time point (p = 0.182). Very good repeatability (intraclass correlation coefficient ICC, quartile coefficient of dispersion QCD) was found for all three devices. However, manual slitlamp measurements showed a higher QCD than the automatic measurements with the Keratograph 5M and the Pentacam HR at all measurement times. Conclusion: The manual and automated methods used in the study to determine corneal diameter showed good agreement and repeatability. No significant diurnal variations of corneal diameter were observed during the period of time studied. Y1 - 2022 U6 - https://doi.org/10.2147/OPTO.S360651 SN - 0816-4622 IS - 14 SP - 173 EP - 181 PB - Taylor & Francis CY - London ER - TY - JOUR A1 - Heinrichs, U. A1 - Pietrzyk, Uwe A1 - Ziemons, Karl T1 - Design optimization of the PMT-ClearPET prototypes based on simulation studies with GEANT3 JF - 2002 IEEE Nuclear Science Symposium Conference Record, Vol. 3 N2 - Within the Crystal Clear Collaboration four centres are developing 2nd generation high performance small animal PET scanners for different kinds of animals and medical applications. The first prototypes are PMT-based systems including depth of interaction (DOI) detection by using a phoswich layer of LSO and LuYAP. The aim of these simulation studies is to optimize sensitivity and spatial resolution of given designs, which vary in FOVs caused by different detector configurations (ring/octagon) and sizes. For this purpose the simulation tool GEANT3 (CERN) was used. The simulations have shown that all PMT designs with one-to-one coupling of crystals have a very nonlinear axial sensitivity profile. By shifting every other PMT 1/4 of a PMT length in axial direction the sampling of the FOVs became more homogeneous. At an energy threshold of 350keV the regression coefficient increases from 0.818 for the non-shifted to 0.993 for the shifted design. Simulations of a point source centred in the FOV (threshold: 350keV) resulted in sensitivities of 4.2% for a 4×20PMT (LSO/LuYAP a 10mm) and 3.8% for a 4×16PMT (LSO/LuYAP a 8mm) ring design. The 3D-MLEM reconstruction of a point source shows the enormous improvement of resolution using a crystal double layer with DOI (3.1mm at 40mm from CFOV) instead of a 20mm single layer (11.9mm). Y1 - 2003 SN - 1082-3654 SP - 682 EP - 686 ER -