@article{GrajewskiHronTurek2005, author = {Grajewski, Matthias and Hron, Jaroslav and Turek, Stefan}, title = {Dual weighted a posteriori error estimation for a new nonconforming linear finite element on quadrilaterals}, series = {Applied Numerical Mathematics}, volume = {54}, journal = {Applied Numerical Mathematics}, number = {3-4}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0168-9274}, doi = {10.1016/j.apnum.2004.09.016}, pages = {504 -- 518}, year = {2005}, abstract = {After a short introduction of a new nonconforming linear finite element on quadrilaterals recently developed by Park, we derive a dual weighted residual-based a posteriori error estimator (in the sense of Becker and Rannacher) for this finite element. By computing a corresponding dual solution we estimate the error with respect to a given target error functional. The reliability and efficiency of this estimator is analyzed in several numerical experiments.}, language = {en} } @article{KhodaverdiChatziioannouWeberetal.2005, author = {Khodaverdi, M. and Chatziioannou, A. F. and Weber, S. and Ziemons, Karl and Halling, H. and Pietrzyk, U.}, title = {Investigation of different MicroCT scanner configurations by GEANT4 simulations}, series = {IEEE Transactions on Nuclear Science}, volume = {52}, journal = {IEEE Transactions on Nuclear Science}, number = {1}, isbn = {0018-9499}, pages = {188 -- 192}, year = {2005}, abstract = {This study has been performed to design the combination of the new ClearPET (ClearPET is a trademark of the Crystal Clear Collaboration), a small animal positron emission tomography (PET) system, with a micro-computed tomography (microCT) scanner. The properties of different microCT systems have been determined by simulations based on GEANT4. We will demonstrate the influence of the detector material and the X-ray spectrum on the obtained contrast. Four different detector materials (selenium, cadmium zinc telluride, cesium iodide and gadolinium oxysulfide) and two X-ray spectra (a molybdenum and a tungsten source) have been considered. The spectra have also been modified by aluminum filters of varying thickness. The contrast between different tissue types (water, air, brain, bone and fat) has been simulated by using a suitable phantom. The results indicate the possibility to improve the image contrast in microCT by an optimized combination of the X-ray source and detector material.}, language = {en} } @article{ZiemonsAuffrayBarbieretal.2005, author = {Ziemons, Karl and Auffray, E. and Barbier, R. and Brandenburg, G. and Bruyndonckx, P.}, title = {The ClearPET™ project: Development of a 2nd generation high-performance small animal PET scanner}, series = {Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment}, volume = {537}, journal = {Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment}, number = {1-2}, issn = {0168-9002}, pages = {307 -- 311}, year = {2005}, abstract = {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.}, language = {en} } @article{StreunChristHellendungetal.2005, author = {Streun, M. and Christ, D. and Hellendung, A. and Larue, H. and Ziemons, Karl and Halling, H.}, title = {Effects of crosstalk and gain nonuniformity using multichannel PMTs in the Clearpet® scanner}, series = {Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment}, volume = {537}, journal = {Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment}, number = {1-2}, isbn = {0168-9002}, pages = {402 -- 405}, year = {2005}, abstract = {The ClearPET® scanners developed by the Crystal Clear Collaboration use multichannel PMTs as photodetectors with scintillator pixels coupled individually to each channel. In order to localize an event each channel anode is connected to a comparator that triggers when the anode signal exceeds a common predefined threshold. Two major difficulties here are crosstalk of light and the gain nonuniformity of the PMT channels. Crosstalk can generate false triggering in channels adjacent to the actual event. On the one hand this can be suppressed by sufficiently increasing the threshold, but on the other hand a threshold too high can already prevent valid events on the lower gain channels from being detected. Finally, both effects restrict the dynamic range of pulse heights that can be processed. The requirements to the dynamic range are not low as the ClearPET® scanners detect the depth of interaction by phoswich pixels consisting of LSO and Lu0.7Y0.3AP, two scintillators with different light yields. We will present a model to estimate the achievable dynamic range and show solutions to increase it.}, language = {en} } @article{MaggakisKelemenDigelArtmann2005, author = {Maggakis-Kelemen, Christina and Digel, Ilya and Artmann, Gerhard}, title = {Polystyrene sulfonate/Polyallylamine hydrochloride microcapsules as potential artificial red blood cells - improvement of capsule flexibility}, series = {Biomedizinische Technik. 50 (2005), H. Erg.-Bd. 1}, journal = {Biomedizinische Technik. 50 (2005), H. Erg.-Bd. 1}, pages = {324 -- 326}, year = {2005}, language = {en} } @article{DigelTemizArtmannNishikawaetal.2005, author = {Digel, Ilya and Temiz Artmann, Ayseg{\"u}l and Nishikawa, K. and Cook, M.}, title = {Bactericidal effects of plasma-generated cluster ions}, series = {Medical and Biological Engineering and Computing. 43 (2005), H. 6}, journal = {Medical and Biological Engineering and Computing. 43 (2005), H. 6}, isbn = {1741-0444}, pages = {800 -- 807}, year = {2005}, language = {en} } @article{KotliarKoshitzSvetlowaetal.2005, author = {Kotliar, Konstantin and Koshitz, I. N. and Svetlowa, O. V. and Makarov, F. N.}, title = {Biomechanical analysis of traditional and contemporary conceptions on pathogenesis of the primary open angle glaucoma / Koshitz, I. N. ; Svetlova, O. V. ; Kotliar, K. E. ; Makarov, F. N. ; Smolnikov, B. A.}, series = {Glaukoma (2005)}, journal = {Glaukoma (2005)}, publisher = {-}, pages = {41 -- 63}, year = {2005}, language = {en} } @article{TemizArtmannSaklamazComlekcietal.2005, author = {Temiz Artmann, Ayseg{\"u}l and Saklamaz, Ali and Comlekci, Abdurrahman and Caliskan, Sezer}, title = {The beneficial effects of lipid-lowering drugs beyond lipid-lowering effects: A comparative study with pravastatin, atorvastatin, and fenofibrate in patients with type IIa and type IIb hyperlipidemia / Saklamaz, Ali ; Comlekci, Abdurrahman ; Temiz, Aysegu}, series = {Metabolism. 54 (2005), H. 5}, journal = {Metabolism. 54 (2005), H. 5}, isbn = {0026-0495}, pages = {677 -- 681}, year = {2005}, language = {en} } @article{KaminskyWeberSimonsetal.2005, author = {Kaminsky, Randolph and Weber, Hans-Joachim and Simons, Antoine and Kallweit, Stephan and Kramm, K. and Verdonck, Pascale}, title = {Comparison of the flow downstream two prototypes of a new monoleaflet artificial aortic heart valve by means of PIV visualization}, series = {Computer methods in biomechanics and biomedical engineering. 8 (2005), H. 4, Suppl. 1}, journal = {Computer methods in biomechanics and biomedical engineering. 8 (2005), H. 4, Suppl. 1}, isbn = {1476-8259}, pages = {159 -- 160}, year = {2005}, language = {en} } @article{KaminskySimonsGatzweileretal.2005, author = {Kaminsky, Randolph and Simons, Antoine and Gatzweiler, Karl-Heinz and Weber, Hans-Joachim}, title = {Flow visualization by means of PIV of an artificial aortic heart valve fixed into a mock aorta}, series = {Acta Mechanica Slovaka 2-A. 9 (2005)}, journal = {Acta Mechanica Slovaka 2-A. 9 (2005)}, pages = {343 -- 348}, year = {2005}, language = {en} }