@article{LagemaatBreukelsVosetal.2016, author = {Lagemaat, Miriam W. and Breukels, Vincent and Vos, Eline K. and Kerr, Adam B. and Uden, Mark J. van and Orzada, Stephan and Bitz, Andreas and Maas, Marnix C. and Scheenen, Tom W. J.}, title = {¹H MR spectroscopic imaging of the prostate at 7T using spectral-spatial pulses}, series = {Magnetic Resonance in Medicine}, volume = {75}, journal = {Magnetic Resonance in Medicine}, number = {3}, publisher = {International Society for Magnetic Resonance in Medicine}, issn = {1522-2594}, doi = {10.1002/mrm.25569}, pages = {933 -- 945}, year = {2016}, abstract = {Purpose To assess the feasibility of prostate ¹H MR spectroscopic imaging (MRSI) using low-power spectral-spatial (SPSP) pulses at 7T, exploiting accurate spectral selection and spatial selectivity simultaneously. Methods A double spin-echo sequence was equipped with SPSP refocusing pulses with a spectral selectivity of 1 ppm. Three-dimensional prostate ¹H-MRSI at 7T was performed with the SPSP-MRSI sequence using an 8-channel transmit array coil and an endorectal receive coil in three patients with prostate cancer and in one healthy subject. No additional water or lipid suppression pulses were used. Results Prostate ¹H-MRSI could be obtained well within specific absorption rate (SAR) limits in a clinically feasible time (10 min). Next to the common citrate signals, the prostate spectra exhibited high spermine signals concealing creatine and sometimes also choline. Residual lipid signals were observed at the edges of the prostate because of limitations in spectral and spatial selectivity. Conclusion It is possible to perform prostate ¹H-MRSI at 7T with a SPSP-MRSI sequence while using separate transmit and receive coils. This low-SAR MRSI concept provides the opportunity to increase spatial resolution of MRSI within reasonable scan times.}, language = {en} } @article{StaatVu2012, author = {Staat, Manfred and Vu, Duc Khoi}, title = {Limit analysis of flaws in pressurized pipes and cylindrical vessels Part II: Circumferential defects}, series = {Engineering Fracture Mechanic}, volume = {97}, journal = {Engineering Fracture Mechanic}, number = {1}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0013-7944}, doi = {10.1016/j.engfracmech.2012.05.017}, pages = {314 -- 333}, year = {2012}, abstract = {Upper and lower bound theorems of limit analyses have been presented in part I of the paper. Part II starts with the finite element discretization of these theorems and demonstrates how both can be combined in a primal-dual optimization problem. This recently proposed numerical method is used to guide the development of a new class of closed-form limit loads for circumferential defects, which show that only large defects contribute to plastic collapse with a rapid loss of strength with increasing crack sizes. The formulae are compared with primal-dual FEM limit analyses and with burst tests. Even closer predictions are obtained with iterative limit load solutions for the von Mises yield function and for the Tresca yield function. Pressure loading of the faces of interior cracks in thick pipes reduces the collapse load of circumferential defects more than for axial flaws. Axial defects have been treated in part I of the paper.}, language = {en} } @article{AggarwalDhimanKumaretal.2012, author = {Aggarwal, Pranav and Dhiman, Shashi K. and Kumar, G. and Scherer, Ulrich W. and Singla, M. L. and Srivastava, Alok}, title = {Optical study of poly(ethyleneterephthalate) modified by different ionizing radiation dose}, series = {Indian Journal of Pure and Applied Physics}, volume = {50}, journal = {Indian Journal of Pure and Applied Physics}, number = {2}, publisher = {Council Of Scientific And Industrial Research (CSIR), National Institute Of Science Communication and Policy Research (NIScPR)}, address = {New Delhi}, issn = {0019-5596}, pages = {129 -- 132}, year = {2012}, abstract = {Thin films of poly(ethyleneterephthalate) [PET]were exposed to radiation dose ranging from 10 to 30 kGy by using gamma rays in the range 12.8-177.8 MGy using swift light ions of hydrogen. There was no effect of the radiation dose on the optical behaviour of PET as a result of exposure to radiation dose up to 30 kGy brought about by gamma rays but a significant decrease in the optical band gap values was observed when PET was exposed to swift light ions of hydrogen. The data obtained are discussed in terms of optical studies carried out on PET using swift heavy ions.}, language = {en} } @article{RibitschKarlBirnerGruenbergeretal.2010, author = {Ribitsch, D. and Karl, W. and Birner-Gruenberger, R. and Gruber, K. and Eiteljoerg, I. and Remler, P. and Wieland, S. and Siegert, Petra and Maurer, Karl-Heinz and Schwab, H.}, title = {C-terminal truncation of a metagenome-derived detergent protease for effective expression in E. coli}, series = {Journal of biotechnology}, volume = {150}, journal = {Journal of biotechnology}, number = {3}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1873-4863 (E-Journal); 0168-1656 (Print)}, doi = {10.1016/j.jbiotec.2010.09.947}, pages = {408 -- 416}, year = {2010}, abstract = {Recently, a new alkaline protease named HP70 showing highest homology to extracellular serine proteases of Stenotrophomonas maltophilia and Xanthomonas campestris was found in the course of a metagenome screening for detergent proteases (Niehaus et al., submitted for publication). Attempts to efficiently express the enzyme in common expression hosts had failed. This study reports on the realization of overexpression in Escherichia coli after structural modification of HP70. Modelling of HP70 resulted in a two-domain structure, comprising the catalytic domain and a C-terminal domain which includes about 100 amino acids. On the basis of the modelled structure the enzyme was truncated by deletion of most of the C-terminal domain yielding HP70-C477. This structural modification allowed effective expression of active enzyme using E. coli BL21-Gold as the host. Specific activity of HP70-C477 determined with suc-l-Ala-l-Ala-l-Pro-l-Phe-p-nitroanilide as the substrate was 30 ± 5 U/mg compared to 8 ± 1 U/mg of the native enzyme. HP70-C477 was most active at 40 °C and pH 7-11; these conditions are prerequisite for a potential application as detergent enzyme. Determination of kinetic parameters at 40 °C and pH = 9.5 resulted in KM = 0.23 ± 0.01 mM and kcat = 167.5 ± 3.6 s⁻¹. MS-analysis of peptide fragments obtained from incubation of HP70 and HP70-C477 with insulin B indicated that the C-terminal domain influences the cleavage preferences of the enzyme. Washing experiments confirmed the high potential of HP70-C477 as detergent protease.}, language = {en} } @article{HenriquesJuradoGrieseretal.2020, author = {Henriques, A. and Jurado, B. and Grieser, M. and Denis-Petit, D. and Chiron, T. and Gaudefroy, L. and Glorius, J. and Langer, Christoph and Litvinov, Yu. A. and Mathieu, L. and Meot, V. and Perez-Sanchez, R. and Pibernat, J. and Reifarth, R. and Roig, O. and Thomas, B. A. and Thomas, B. A. and Thomas, J. C. and Tsekhanovich, I.}, title = {Indirect measurements of neutron cross-secti at heavy-ion storage rings}, series = {Journal of Physics: Conference Series}, volume = {1668}, journal = {Journal of Physics: Conference Series}, number = {Art. 012019}, publisher = {IOP}, address = {Bristol}, doi = {10.1088/1742-6596/1668/1/012019}, year = {2020}, abstract = {Cross sections for neutron-induced reactions of short-lived nuclei are essential for nuclear astrophysics since these reactions in the stars are responsible for the production of most heavy elements in the universe. These reactions are also key in applied domains like energy production and medicine. Nevertheless, neutron-induced cross-section measurements can be extremely challenging or even impossible to perform due to the radioactivity of the targets involved. Indirect measurements through the surrogate-reaction method can help to overcome these difficulties. The surrogate-reaction method relies on the use of an alternative reaction that will lead to the formation of the same excited nucleus as in the neutron-induced reaction of interest. The decay probabilities (for fission, neutron and gamma-ray emission) of the nucleus produced via the surrogate reaction allow one to constrain models and the prediction of the desired neutron cross sections. We propose to perform surrogate reaction measurements in inverse kinematics at heavy-ion storage rings, in particular at the CRYRING@ESR of the GSI/FAIR facility. We present the conceptual idea of the most promising setup to measure for the first time simultaneously the fission, neutron and gamma-ray emission probabilities. The results of the first simulations considering the 238U(d,d') reaction are shown, as well as new technical developments that are being carried out towards this set-up.}, language = {en} } @article{BrockhausBehbahaniMurisetal.2021, author = {Brockhaus, Moritz K. and Behbahani, Mehdi and Muris, Farina and Jansen, Sebastian V. and Schmitz-Rode, Thomas and Steinseifer, Ulrich and Clauser, Johanna C.}, title = {In vitro thrombogenicity testing of pulsatile mechanical circulatory support systems: Design and proof-of-concept}, series = {Artificial Organs}, volume = {45}, journal = {Artificial Organs}, number = {12}, publisher = {Wiley}, address = {Weinheim}, issn = {1525-1594}, doi = {10.1111/aor.14046}, pages = {1513 -- 1521}, year = {2021}, abstract = {Thrombogenic complications are a main issue in mechanical circulatory support (MCS). There is no validated in vitro method available to quantitatively assess the thrombogenic performance of pulsatile MCS devices under realistic hemodynamic conditions. The aim of this study is to propose a method to evaluate the thrombogenic potential of new designs without the use of complex in-vivo trials. This study presents a novel in vitro method for reproducible thrombogenicity testing of pulsatile MCS systems using low molecular weight heparinized porcine blood. Blood parameters are continuously measured with full blood thromboelastometry (ROTEM; EXTEM, FIBTEM and a custom-made analysis HEPNATEM). Thrombus formation is optically observed after four hours of testing. The results of three experiments are presented each with two parallel loops. The area of thrombus formation inside the MCS device was reproducible. The implantation of a filter inside the loop catches embolizing thrombi without a measurable increase of platelet activation, allowing conclusions of the place of origin of thrombi inside the device. EXTEM and FIBTEM parameters such as clotting velocity (α) and maximum clot firmness (MCF) show a total decrease by around 6\% with a characteristic kink after 180 minutes. HEPNATEM α and MCF rise within the first 180 minutes indicate a continuously increasing activation level of coagulation. After 180 minutes, the consumption of clotting factors prevails, resulting in a decrease of α and MCF. With the designed mock loop and the presented protocol we are able to identify thrombogenic hot spots inside a pulsatile pump and characterize their thrombogenic potential.}, language = {en} } @article{FerreinSteinbauerVassos2012, author = {Ferrein, Alexander and Steinbauer, Gerald and Vassos, Stavros}, title = {Action-Based Imperative Programming with YAGI}, series = {AAAI Technical Report}, journal = {AAAI Technical Report}, publisher = {AAAI}, address = {Menlo Park}, pages = {24 -- 31}, year = {2012}, abstract = {Many tasks for autonomous agents or robots are best described by a specification of the environment and a specification of the available actions the agent or robot can perform. Combining such a specification with the possibility to imperatively program a robot or agent is what we call the actionbased imperative programming. One of the most successful such approaches is Golog. In this paper, we draft a proposal for a new robot programming language YAGI, which is based on the action-based imperative programming paradigm. Our goal is to design a small, portable stand-alone YAGI interpreter. We combine the benefits of a principled domain specification with a clean, small and simple programming language, which does not exploit any side-effects from the implementation language. We discuss general requirements of action-based programming languages and outline YAGI, our action-based language approach which particularly aims at embeddability.}, language = {en} } @inproceedings{SchuetzBreuerHoefkenetal.2013, author = {Sch{\"u}tz, P. and Breuer, M. and H{\"o}fken, Hans-Wilhelm and Schuba, Marko}, title = {Malware proof on mobile phone exhibits based on GSM/GPRS traces}, series = {The Second International Conference on Cyber Security, Cyber Peacefare and Digital Forensic (CyberSec 2013) : 04.03. - 06.03.2013, Kuala Lumpur, Malaysia}, booktitle = {The Second International Conference on Cyber Security, Cyber Peacefare and Digital Forensic (CyberSec 2013) : 04.03. - 06.03.2013, Kuala Lumpur, Malaysia}, publisher = {The Society of Digital Information and Wireless Communication}, isbn = {978-0-9853483-7-3}, pages = {89 -- 96}, year = {2013}, language = {en} } @article{SchaeferHoefkenSchuba2011, author = {Schaefer, Thomas and H{\"o}fken, Hans-Wilhelm and Schuba, Marko}, title = {Windows Phone 7 from a Digital Forensics' Perspective}, publisher = {Springer}, address = {Berlin}, year = {2011}, language = {en} } @article{FrauenrathHezelRenzetal.2010, author = {Frauenrath, Tobias and Hezel, Fabian and Renz, Wolfgang and de Geyer d'Orth, Thibaut and Dieringer, Matthias and von Knobelsdorf-Brenkenhoff, Florian and Prothmann, Marcel and Schulz-Menger, Jeanette and Niendorf, Thoralf}, title = {Acoustic cardiac triggering: a practical solution for synchronization and gating of cardiovascular magnetic resonance at 7 Tesla}, series = {Journal of Cardiovascular Magnetic Resonance}, volume = {12}, journal = {Journal of Cardiovascular Magnetic Resonance}, number = {1}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1532-429X}, doi = {10.1186/1532-429X-12-67}, year = {2010}, abstract = {Background To demonstrate the applicability of acoustic cardiac triggering (ACT) for imaging of the heart at ultrahigh magnetic fields (7.0 T) by comparing phonocardiogram, conventional vector electrocardiogram (ECG) and traditional pulse oximetry (POX) triggered 2D CINE acquisitions together with (i) a qualitative image quality analysis, (ii) an assessment of the left ventricular function parameter and (iii) an examination of trigger reliability and trigger detection variance derived from the signal waveforms. Results ECG was susceptible to severe distortions at 7.0 T. POX and ACT provided waveforms free of interferences from electromagnetic fields or from magneto-hydrodynamic effects. Frequent R-wave mis-registration occurred in ECG-triggered acquisitions with a failure rate of up to 30\% resulting in cardiac motion induced artifacts. ACT and POX triggering produced images free of cardiac motion artefacts. ECG showed a severe jitter in the R-wave detection. POX also showed a trigger jitter of approximately Δt = 72 ms which is equivalent to two cardiac phases. ACT showed a jitter of approximately Δt = 5 ms only. ECG waveforms revealed a standard deviation for the cardiac trigger offset larger than that observed for ACT or POX waveforms. Image quality assessment showed that ACT substantially improved image quality as compared to ECG (image quality score at end-diastole: ECG = 1.7 ± 0.5, ACT = 2.4 ± 0.5, p = 0.04) while the comparison between ECG vs. POX gated acquisitions showed no significant differences in image quality (image quality score: ECG = 1.7 ± 0.5, POX = 2.0 ± 0.5, p = 0.34). Conclusions The applicability of acoustic triggering for cardiac CINE imaging at 7.0 T was demonstrated. ACT's trigger reliability and fidelity are superior to that of ECG and POX. ACT promises to be beneficial for cardiovascular magnetic resonance at ultra-high field strengths including 7.0 T.}, language = {en} }