TY - JOUR A1 - Özsoylu, Dua A1 - Kizildag, Sefa A1 - Schöning, Michael Josef A1 - Wagner, Torsten T1 - Effect of plasma treatment on the sensor properties of a light‐addressable potentiometric sensor (LAPS) JF - physica status solidi a : applications and materials sciences N2 - A light-addressable potentiometric sensor (LAPS) is a field-effect-based (bio-) chemical sensor, in which a desired sensing area on the sensor surface can be defined by illumination. Light addressability can be used to visualize the concentration and spatial distribution of the target molecules, e.g., H+ ions. This unique feature has great potential for the label-free imaging of the metabolic activity of living organisms. The cultivation of those organisms needs specially tailored surface properties of the sensor. O2 plasma treatment is an attractive and promising tool for rapid surface engineering. However, the potential impacts of the technique are carefully investigated for the sensors that suffer from plasma-induced damage. Herein, a LAPS with a Ta2O5 pH-sensitive surface is successfully patterned by plasma treatment, and its effects are investigated by contact angle and scanning LAPS measurements. The plasma duration of 30 s (30 W) is found to be the threshold value, where excessive wettability begins. Furthermore, this treatment approach causes moderate plasma-induced damage, which can be reduced by thermal annealing (10 min at 300 °C). These findings provide a useful guideline to support future studies, where the LAPS surface is desired to be more hydrophilic by O2 plasma treatment. Y1 - 2019 U6 - http://dx.doi.org/10.1002/pssa.201900259 SN - 1862-6319 N1 - Corresponding author: Torsten Wagner VL - 216 IS - 20 PB - Wiley CY - Weinheim 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 - http://dx.doi.org/10.1016/j.phmed.2020.100030 SN - 2352-4510 VL - 10 IS - 100030 PB - Elsevier CY - Amsterdam 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 - http://dx.doi.org/10.17185/duepublico/48750 SP - 36 EP - 37 PB - Universität Duisburg-Essen CY - Duisburg 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 - 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 - 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 - 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 - Bruyndonckx, P. A1 - Perez, J. M. A1 - Pietrzyk, U. A1 - Rato, P. A1 - Tavernier, S. T1 - Beyond ClearPET: Next Aims JF - 5th IEEE International Symposium on Biomedical Imaging: From Nano to Macro Symposium Proceedings ISBI 2008 N2 - The CRYSTAL CLEAR collaboration, in short CCC, is a consortium of 12 academic institutions, mainly from Europe, joining efforts in the area of developing instrumentation for nuclear medicine and medical imaging. In the framework of the CCC a high performance small animal PET system, called ClearPET, was developed by using new technologies in electronics and crystals in a phoswich arrangement combining two types of lutetium- based scintillator materials: LSO:Ce and LuYAP:Ce. Our next aim will be the development of hybrid image systems. Hybrid MR-PET imaging has many unique advantages for brain research. This has sparked a new research line within CCC for the development of novel MR-PET compatible technologies. MRI is not as sensitive as PET but PET has poorer spatial resolution than MRI. Two major advantages of PET are sensitivity and its ability to acquire metabolic information. To assess these innovations, the development of a 9.4T hybrid animal MR-PET scanner is proposed based on an existing 9.4T MR scanner that will be adapted to enable simultaneous acquisition of MR and PET data using cutting- edge technology for both MR and PET. Y1 - 2008 SN - 978-1-4244-2003-2 SP - 1421 EP - 1424 ER - TY - JOUR A1 - Ziemons, Karl A1 - Berghoff, G. A1 - Lanske, D. A1 - Schultze, K. T1 - Strangeness production in deep inelastic muon-nucleon scattering JF - Verhandlungen der Deutschen Physikalischen Gesellschaft Y1 - 1988 SN - 0420-0195 VL - 23 IS - 5 SP - T309 EP - T309 ER - TY - JOUR A1 - Ziemons, Karl A1 - Auffray, E. A1 - Barbier, R. A1 - Brandenburg, G. A1 - Bruyndonckx, P. T1 - The ClearPET™ project: Development of a 2nd generation high-performance small animal PET scanner JF - Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment N2 - Second generation high-performance PET scanners, called ClearPET™1, have been developed by working groups of the Crystal Clear Collaboration (CCC). High sensitivity and high spatial resolution for the ClearPET camera is achieved by using a phoswich arrangement combining two different types of lutetium-based scintillator materials: LSO from CTI and LuYAP:Ce from the CCC (ISTC project). In a first ClearPET prototype, phoswich arrangements of 8×8 crystals of 2×2×10 mm3 are coupled to multi-channel photomultiplier tubes (Hamamatsu R7600). A unit of four PMTs arranged in-line represents one of 20 sectors of the ring design. The opening diameter of the ring is 120 mm, the axial detector length is 110 mm.The PMT pulses are digitized by free-running ADCs and digital data processing determines the gamma energy, the phoswich layer and even the exact pulse starting time, which is subsequently used for coincidence detection. The gantry allows rotation of the detector modules around the field of view. Preliminary data shows a correct identification of the crystal layer about (98±1)%. Typically the energy resolution is (23.3±0.5)% for the luyap layer and (15.4±0.4)% for the lso layer. early studies showed the timing resolution of 2 ns FWHM and 4.8 ns FWTM. the intrinsic spatial resolution ranges from 1.37 mm to 1.61 mm full-width of half-maximum (FWHM) with a mean of 1.48 mm FWHM. further improvements in image and energy resolution are expected when the system geometry is fully modeled. Y1 - 2005 SN - 0168-9002 N1 - Proceedings of the 7th International Conference on Inorganic Scintillators and their Use in Scientific and Industrial Applications VL - 537 IS - 1-2 SP - 307 EP - 311 ER -