TY  - JOUR
A1  - Weemstra, Monique
A1  - Eilmann, Britta
A1  - Sass-Klaassen, Ute G. W.
A1  - Sterck, Frank J.
T1  - Summer droughts limit tree growth across 10 temperate species on a productive forest site
JF  - Forest Ecology and Management
Y1  - 2013
U6  - http://dx.doi.org/doi:10.1016/j.foreco.2013.06.007
SN  - 0378-1127 (Print)
SN  - 1872-7042  (Online)
VL  - 2013
IS  - 306
SP  - 142
EP  - 149
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Wedrowski, M.
A1  - Bruyndonckx, P.
A1  - Tavernier, S.
A1  - Zhi, L.
A1  - Dang, J.
A1  - Mendes, P. R.
A1  - Perez, J. M.
A1  - Ziemons, Karl
T1  - Robustness of neural networks algorithm for gamma detection in monolithic block detector, positron emission tomography
JF  - 2009 IEEE Nuclear Science Symposium Conference Record (NSS/MIC)
N2  - The monolithic scintillator block approach for gamma detection in the Positron Emission Tomography (PET) avoids estimating Depth of Interaction (DOI), reduces dead zones in detector and diminishes costs of detector production. Neural Networks (NN) are very efficient to determine the entrance point of a gamma incident on a scintillator block. This paper presents results on the robustness of the spatial resolution as a function of the random fraction in the data, temperature and HV fluctuations. This is important when implementing the method in a real scanner. Measurements were done with two Hamamatsu S8550 APD arrays, glued on a 20 × 20 × 10 mm3 monolithic LSO crystal block.
Y1  - 2009
SN  - 1082-3654
SP  - 2625
EP  - 2628
ER  - 
TY  - JOUR
A1  - Weckesser, Matthias
A1  - Hufnagel, Andreas
A1  - Ziemons, Karl
A1  - Grießmeier, Martin
A1  - Sonnenberg, Frank
A1  - Hackländer, Thomas
A1  - Langen, Karl-J.
A1  - Holschbach, Markus
A1  - Elger, Christian E.
A1  - Müller-Gärtner, Hans-W.
T1  - Effect of partial volume correction on muscarinic cholinergic receptor imaging with single-photon emission tomography in patients with temporal lobe epilepsy
JF  - European Journal of Nuclear Medicine
N2  - Animal experiments and preliminary results in humans have indicated alterations of hippocampal muscarinic acetylcholine receptors (mAChR) in temporal lobe epilepsy. Patients with temporal lobe epilepsy often present with a reduction in hippocampal volume. The aim of this study was to investigate the influence of hippocampal atrophy on the quantification of mAChR with single photon emission tomography (SPET) in patients with temporal lobe epilepsy. Cerebral uptake of the muscarinic cholinergic antagonist [123I]4-iododexetimide (IDex) was investigated by SPET in patients suffering from temporal lobe epilepsy of unilateral (n=6) or predominantly unilateral (n=1) onset. Regions of interest were drawn on co-registered magnetic resonance images. Hippocampal volume was determined in these regions and was used to correct the SPET results for partial volume effects. A ratio of hippocampal IDex binding on the affected side to that on the unaffected side was used to detect changes in muscarinic cholinergic receptor density. Before partial volume correction a decrease in hippocampal IDex binding on the focus side was found in each patient. After partial volume no convincing differences remained. Our results indicate that the reduction in hippocampal IDex binding in patients with epilepsy is due to a decrease in hippocampal volume rather than to a decrease in receptor concentration.
Y1  - 1997
SN  - 1619-7089
VL  - 24
IS  - 9
SP  - 1156
EP  - 1161
ER  - 
TY  - JOUR
A1  - Weckesser, Martin
A1  - Grießmeier, Martin
A1  - Schmidt, Daniela
A1  - Sonnenberg, Frank
A1  - Ziemons, Karl
A1  - Kemna, Lars
A1  - Holschbach, Marcus
A1  - Langen, Karl-J.
A1  - Müller-Gärtner, Hans-W.
T1  - Iodine-123 α-methyl tyrosine single-photon emission tomography of cerebral gliomas: standardised evaluation of tumour uptake and extent
JF  - European Journal of Nuclear Medicine
N2  - Single-photon emission tomography (SPET) with the amino acid analogue l-3-[123I]iodo-α-methyl tyrosine (IMT) is helpful in the diagnosis and monitoring of cerebral gliomas. Radiolabelled amino acids seem to reflect tumour infiltration more specifically than conventional methods like magnetic resonance imaging and computed tomography. Automatic tumour delineation based on maximal tumour uptake may cause an overestimation of mean tumour uptake and an underestimation of tumour extension in tumours with circumscribed peaks. The aim of this study was to develop a program for tumour delineation and calculation of mean tumour uptake which takes into account the mean background activity and is thus optimised to the problem of tumour definition in IMT SPET. Using the frequency distribution of pixel intensities of the tomograms a program was developed which automatically detects a reference brain region and draws an isocontour region around the tumour taking into account mean brain radioactivity. Tumour area and tumour/brain ratios were calculated. A three-compartment phantom was simulated to test the program. The program was applied to IMT SPET studies of 20 patients with cerebral gliomas and was compared to the results of manual analysis by three different investigators. Activity ratios and chamber extension of the phantom were correctly calculated by the automatic analysis. A method based on image maxima alone failed to determine chamber extension correctly. Manual region of interest analysis in patient studies resulted in a mean inter-observer standard deviation of 8.7%±6.1% (range 2.7%–25.0%). The mean value of the results of the manual analysis showed a significant correlation to the results of the automatic analysis (r = 0.91, P<0.0001 for the uptake ratio; r = 0.87, P<0.0001 for the tumour area). We conclude that the algorithm proposed simplifies the calculation of uptake ratios and may be used for observer-independent evaluation of IMT SPET studies. Three-dimensional tumour recognition and transfer to co-registered morphological images based on this program may be useful for the planning of surgical and radiation treatment.
Y1  - 1998
SN  - 1619-7089
VL  - 25
IS  - 2
SP  - 150
EP  - 156
ER  - 
TY  - CHAP
A1  - Weber, Tobias
A1  - Tellis, Jane J.
A1  - Duhovic, Miro
T1  - Characterization of tool-part-interaction an interlaminar friction for manufacturing process simulation
T2  - ECCM 17, 17th European Conference on Composite Materials, München, DE, Jun 26-30, 2016
Y1  - 2016
SN  - 978-3-00-053387-7
SP  - 1
EP  - 7
ER  - 
TY  - JOUR
A1  - Weber, Tobias
A1  - Ruff-Stahl, Hans-Joachim K.
T1  - Advances in Composite Manufacturing of Helicopter Parts
JF  - International Journal of Aviation, Aeronautics, and Aerospace
Y1  - 2017
U6  - http://dx.doi.org/10.15394/ijaaa.2017.1153
SN  - 2374-6793
VL  - 4
IS  - 1
ER  - 
TY  - CHAP
A1  - Weber, Tobias
A1  - Englhard, Markus
A1  - Hailer, Benjamin
A1  - Arent, Jan-Christoph
T1  - Manufacturing Process Simulation for the Prediction of Tool-Part-Interaction and Ply Wrinkling
T2  - Proceedings of SAMPE Europe Conference 2019, Nantes, France
Y1  - 2019
SP  - 1
EP  - 10
ER  - 
TY  - CHAP
A1  - Weber, Tobias
A1  - Englhard, Markus
A1  - Hailer, Benjamin
A1  - Arent, Jan-Christoph
T1  - Manufacturing Process Simulation for the Prediction of Tool-Part-Interaction and Ply Wrinkling
T2  - Proceedings of SAMPE Europe Conference, Amiens , France
Y1  - 2015
SP  - 1
EP  - 10
ER  - 
TY  - JOUR
A1  - Weber, Tobias
A1  - Englhard, Markus
A1  - Arent, Jan-Christoph
A1  - Hausmann, Joachim
T1  - An experimental characterization of wrinkling generated during prepreg autoclave manufacturing using caul plates
JF  - Journal of Composite Materials
Y1  - 2019
U6  - http://dx.doi.org/10.1177/0021998319846556
SN  - 1530-793X
VL  - 53
IS  - 26-27
SP  - 3757
EP  - 3773
ER  - 
TY  - JOUR
A1  - Weber, Tobias
A1  - Arent, Jan-Christoph
A1  - Steffen, Lucas
A1  - Balvers, Johannes M.
A1  - Duhovic, Miro
T1  - Thermal optimization of composite autoclave molds using the shift factor approach for boundary condition estimation
JF  - Journal of Composite Materials
Y1  - 2017
U6  - http://dx.doi.org/10.1177/0021998317699868
SN  - 1530-793X
VL  - 51
IS  - 12
SP  - 1753
EP  - 1767
PB  - Sage
CY  - London
ER  - 
TY  - JOUR
A1  - Weber, Tobias
A1  - Arent, Jan-Christoph
A1  - Münch, Lukas
A1  - Duhovic, Miro
A1  - Balvers, Johannes M.
T1  - A fast method for the generation of boundary conditions for thermal autoclave simulation
JF  - Composites Part A
N2  - Manufacturing process simulation enables the evaluation and improvement of autoclave mold concepts early in the design phase. To achieve a high part quality at low cycle times, the thermal behavior of the autoclave mold can be investigated by means of simulations. Most challenging for such a simulation is the generation of necessary boundary conditions. Heat-up and temperature distribution in an autoclave mold are governed by flow phenomena, tooling material and shape, position within the autoclave, and the chosen autoclave cycle. This paper identifies and summarizes the most important factors influencing mold heat-up and how they can be introduced into a thermal simulation. Thermal measurements are used to quantify the impact of the various parameters. Finally, the gained knowledge is applied to develop a semi-empirical approach for boundary condition estimation that enables a simple and fast thermal simulation of the autoclave curing process with reasonably high accuracy for tooling optimization.
Y1  - 2016
U6  - http://dx.doi.org/10.1016/j.compositesa.2016.05.036
SN  - 1359-835X
VL  - 88
SP  - 216
EP  - 225
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - CHAP
A1  - Weber, Tobias
T1  - Manufacturing Process Simulation for Tooling Optimization: Reduction of Quality Issues During Autoclave Manufacturing of Composite Parts
T2  - Proceedings of SAMPE Europe Conference 2015, Amiens, France
Y1  - 2015
SP  - 1
EP  - 8
ER  - 
TY  - CHAP
A1  - Weber, S.
A1  - Terstegge, Andreas
A1  - Halling, H.
A1  - Herzog, H.
A1  - Reinartz, R.
A1  - Reinhart, P.
A1  - Rongen, F.
A1  - Müller-Gärtner, H.-W.
T1  - The design of an animal PET: flexible geometry for achieving optimal spatial resolution or high sensitivity
T2  - Conference record / 1995 IEEE Nuclear Science Symposium and Medical Imaging, October 21 - 28, 1995, San Francisco ; vol. 2
Y1  - 1995
SN  - 078033180X ; 0780331818 ; 0780331826
SP  - 1002
EP  - 1005
PB  - IEEE
CY  - Piscataway, NJ
ER  - 
TY  - CHAP
A1  - Weber, S.
A1  - Terstegge, Andreas
A1  - Engels, R.
A1  - Herzog, H.
A1  - Reinartz, R.
A1  - Reinhart, P.
A1  - Rongen, F.
A1  - Müller-Gärtner, H. W.
A1  - Halling, H.
T1  - The KFA TierPET: performance characteristics and measurements
T2  - Conference record / 1996 IEEE Nuclear Science Symposium [and Medical Imaging], November 2 - 9, 1996, Anaheim, California ; vol. 2
Y1  - 1996
SN  - 0-7803-3534-1
SN  - 1082-3654
SP  - 1117
EP  - 1119
PB  - IEEE
CY  - Piscataway, NJ
ER  - 
TY  - CHAP
A1  - Weber, Ingo
A1  - Markovic, Ivan
A1  - Drumm, Christian
T1  - A conceptual framework for composition in business process management
T2  - Business Information Systems : 10th International Conference, BIS 2007, Poznan, Poland, April 25-27, 2007. Proceedings
Y1  - 2007
SN  - 978-3-540-72035-5
U6  - http://dx.doi.org/10.1007/978-3-540-72035-5_5
SP  - 54
EP  - 66
PB  - Springer
CY  - Berlin, Heidelberg
ER  - 
TY  - CHAP
A1  - Weber, Hans-Joachim
A1  - Porschen, W.
A1  - Dietzel, F.
A1  - [u.a.], 
ED  - Streffer, Christian
T1  - In vivo analysis of the influence of combined hyperthermia and gamma irradiation on euoxic and hypoxic tumor cells
T2  - Cancer therapy by hyperthermia and radiation : [proceedings of the 2. International Symposium on Cancer Therapy by Hyperthermia and Radiation, Essen, 2.-4.6.1977]
Y1  - 1978
SN  - 0-8067-1701-7
SN  - 3-541-71701-7
SP  - 276
EP  - 277
PB  - Urban and Schwarzenberg
CY  - Baltimore ; Munich [u.a.]
ER  - 
TY  - JOUR
A1  - Weber, Hans-Joachim
A1  - Mo, Xiumei
A1  - Ramakrishna, S.
T1  - PCL-PGLA composite tubular scaffold preparation and biocompatibility investigation / X. Mo, H.-J. Weber, S. Ramakrishna
JF  - The International journal of artificial organs. 29 (2006), H. 8
Y1  - 2006
SP  - 790
EP  - 799
PB  - -
ER  - 
TY  - JOUR
A1  - Weber, Hans-Joachim
A1  - Mo, Xiumei
A1  - Chen, Zonggang
T1  - Electrospun nanofibers of collagen-chitosan and P(LLA-CL) for tissue engineering / Mo Xiumei, Chen Zonggang, Hans J. Weber
JF  - Frontiers of materials science in China. 1 (2007), H. 1
Y1  - 2007
SN  - 1673-7377
SP  - 20
EP  - 23
PB  - -
ER  - 
TY  - JOUR
A1  - Weber, Hans-Joachim
A1  - Mo, Xiumei
T1  - Electrospinning P(LLA-CL) nanofiber: a tubular scaffold fabrication with circumferential alignment / Xiumei Mo, Hans-Joachim Weber
JF  - Contributions from 6th Austrian Polymer Meeting : Vienna, Austria, September 15 - 17, 2003 / Symposium ed.: W. H. Binder
Y1  - 2004
N1  - Österreichische Polymertage <6, 2003, Wien>. - (Macromolecular symposia ; 217,1)
SP  - 413
EP  - 416
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Weber, Hans-Joachim
A1  - Laco, Filip
A1  - Kun, Ma
A1  - Ramakrishna, S.
T1  - The dose effect of human bone marrow-derived mesenchymal stem cells on epidermal development in organotypic co-culture / Laco, Filip ; Kun, Ma ; Weber, Hans Joachim ; Ramakrishna, S. ; Chan, Casey K.
JF  - Journal of Dermatological Science. 55 (2009), H. 3
Y1  - 2009
SN  - 0923-1811
SP  - 150
EP  - 160
ER  -