TY  - JOUR
A1  - Ziemons, Karl
A1  - Heinrichs, U.
A1  - Streun, M.
A1  - Pietrzyk, U.
T1  - Validation of GEANT3 simulation studies with a dual-head PMT ClearPET™ prototype
JF  - 2003 IEEE Nuclear Science Symposium Conference Record, Vol. 5
N2  - The ClearPET™ project is proposed by working groups of the Crystal Clear Collaboration (CCC) to develop a 2nd generation high performance small animal positron emission tomograph (PET). High sensitivity and high spatial resolution is foreseen for the ClearPET™ camera by using a phoswich arrangement combining mixed lutetium yttrium aluminum perovskite (LuYAP:Ce) and lutetium oxyorthosilicate (LSO) scintillating crystals. Design optimizations for the first photomultiplier tube (PMT) based ClearPET camera are done with a Monte-Carlo simulation package implemented on GEANT3 (CERN, Geneva, Switzerland). A dual-head prototype has been built to test the frontend electronics and was used to validate the implementation of the GEANT3 simulation tool. Multiple simulations were performed following the experimental protocols to measure the intrinsic resolution and the sensitivity profile in axial and radial direction. Including a mean energy resolution of about 27.0% the simulated intrinsic resolution is about (1.41±0.11)mm compared to the measured of (1.48±0.06)mm. The simulated sensitivity profiles show a mean square deviation of 12.6% in axial direction and 3.6% in radial direction. Satisfactorily these results are representative for all designs and confirm the scanner geometry.
Y1  - 2004
SN  - 1082-3654
SP  - 3053
EP  - 3056
ER  - 
TY  - JOUR
A1  - Ziemons, Karl
A1  - Herzog, H.
A1  - Bosetti, P.
A1  - Feinendegen, L. E.
T1  - Iterative image reconstruction with weighted pixel contribution to projection elements
JF  - European Journal of Nuclear Medicine
Y1  - 1992
SN  - 1619-7089
N1  - Abstracts of the European Association of Nuclear Medicine Congress 23–26 August 1992 Lisboa, Portugal ; V143-2
VL  - 19
IS  - 8
SP  - 588
EP  - 588
ER  - 
TY  - JOUR
A1  - Ziemons, Karl
A1  - Herzog, H.
A1  - Feinendegen, L. E.
T1  - Iterative image reconstruction with weighted pixel contribution to projection element
JF  - European Journal of Nuclear Medicine
Y1  - 1990
SN  - 1619-7089
N1  - Abstracts of the European Association of Nuclear Medicine Congress ; V52
VL  - 16
IS  - 7
SP  - 403
EP  - 403
ER  - 
TY  - JOUR
A1  - Ziemons, Karl
A1  - Kleines, H.
A1  - Erken, I.
A1  - Knoben, J.
A1  - Zwoll, K.
ED  - Lehmann, Thomas
T1  - IME-DV Projekt: M-FIRBe, Multi-Modality Functional Imaging for Brain Research
JF  - Bildverarbeitung für die Medizin : Algorithmen - Systeme - Anwendungen
Y1  - 1997
SN  - 3-86073-519-5
N1  - Proceedings des Aachener Workshops am 8. u. 9. November 1996 ; WG_005 Arbeitsgruppenvorstellungen
SP  - 363
EP  - 366
PB  - Verl. der. Augustinus-Buchh.
CY  - Aachen
ER  - 
TY  - CHAP
A1  - Zingsheim, Jonas
A1  - Grimmer, Timo
A1  - Ortner, Marion
A1  - Schmaderer, Christoph
A1  - Hauser, Christine
A1  - Kotliar, Konstantin
ED  - Staat, Manfred
ED  - Erni, Daniel
T1  - Recognition of subjects with mild cognitive impairment (MCI) by the use of retinal arterial vessels.
T2  - 3rd YRA MedTech Symposium 2019 : May 24 / 2019 / FH Aachen
Y1  - 2019
SN  - 978-3-940402-22-6
U6  - https://doi.org/10.17185/duepublico/48750
SP  - 36
EP  - 37
PB  - Universität Duisburg-Essen
CY  - Duisburg
ER  - 
TY  - JOUR
A1  - Özsoylu, Dua
A1  - Kizildag, Sefa
A1  - Schöning, Michael Josef
A1  - Wagner, Torsten
T1  - Differential chemical imaging of extracellular acidification within microfluidic channels using a plasma-functionalized light-addressable potentiometric sensor (LAPS)
JF  - Physics in Medicine
N2  - Extracellular acidification is a basic indicator for alterations in two vital metabolic pathways: glycolysis and cellular respiration. Measuring these alterations by monitoring extracellular acidification using cell-based biosensors such as LAPS plays an important role in studying these pathways whose disorders are associated with numerous diseases including cancer. However, the surface of the biosensors must be specially tailored to ensure high cell compatibility so that cells can represent more in vivo-like behavior, which is critical to gain more realistic in vitro results from the analyses, e.g., drug discovery experiments. In this work, O2 plasma patterning on the LAPS surface is studied to enhance surface features of the sensor chip, e.g., wettability and biofunctionality. The surface treated with O2 plasma for 30 s exhibits enhanced cytocompatibility for adherent CHO–K1 cells, which promotes cell spreading and proliferation. The plasma-modified LAPS chip is then integrated into a microfluidic system, which provides two identical channels to facilitate differential measurements of the extracellular acidification of CHO–K1 cells. To the best of our knowledge, it is the first time that extracellular acidification within microfluidic channels is quantitatively visualized as differential (bio-)chemical images.
Y1  - 2020
U6  - https://doi.org/10.1016/j.phmed.2020.100030
SN  - 2352-4510
VL  - 10
IS  - 100030
PB  - Elsevier
CY  - Amsterdam
ER  -