@phdthesis{Benner1984, author = {Benner, Joachim}, title = {Experimentelle Untersuchungen des mechanischen Verhaltens drehnachgiebiger Wellenkupplungen und Entwicklung eines Ersatzmodells}, pages = {147 S. : graph. Darst.}, year = {1984}, language = {de} } @article{SchnabelSchnabelBerndt1971, author = {Schnabel, Eugen and Schnabel, Henning and Berndt, Heinz}, title = {Zur selektiven acidolytischen Abspaltbarkeit der tert.-Butyloxycarbonyl-Gruppe}, series = {Justus Liebigs Annalen der Chemie}, volume = {749}, journal = {Justus Liebigs Annalen der Chemie}, number = {1}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1099-0690}, doi = {10.1002/jlac.19717490111}, pages = {90 -- 108}, year = {1971}, abstract = {Die tert.-Butyloxycarbonyl-Gruppe (Boc) l{\"a}ßt sich mittels reiner Trifluoressigs{\"a}ure nicht selektiv neben dem Benzyloxycarbonyl-Rest (Z) abspalten. Das gelingt auch nicht mit L{\"o}sungen von Trifluoressigs{\"a}ure bzw. Chlorwasserstoff in organischen L{\"o}sungsmitteln. Kern-substituierte Z-Gruppen wie Z(pCl), Z(mCl) oder Z(pNO₂) sind zwar stabiler, werden aber von den obengenannten Reagenzien ebenfalls angegriffen bzw. sind nicht mehr acidolytisch abspaltbar. - Mit 70proz. w{\"a}ßriger Trifluoressigs{\"a}ure gelingt die Abspaltung von Boc neben Z dagegen fast selektiv; dabei werden aber Benzylester, besonders Glutamins{\"a}ure-γ-benzylester, teilweise hydrolysiert, w{\"a}hrend Methyl- sowie {\"A}thylester nahezu best{\"a}ndig sind. Die Brauchbarkeit des Abspaltungsverfahrens wird anhand der schrittweise durchgef{\"u}hrten Synthese zweier Heptapeptid-Derivate gezeigt. - {\"A}hnlich spezifisch gelingt die Abspaltung von Boc mit Bortrifluorid-{\"a}therat in Eisessig; Benzylester sind gegen{\"u}ber diesem Reagenz stabiler als gegen w{\"a}ßrige Trifluoressigs{\"a}ure. Das Bortrifluorid-Verfahren eignet sich besonders f{\"u}r die Abspaltung von Boc-Gruppen neben s{\"a}urelabilen Thiol-Schutzgruppen (Tetrahydropyranyl- bzw. Trityl-Rest) sowie neben dem Cyclocystinyl-Rest. Die Leistungsf{\"a}higkeit der Methode wird durch die Synthese zweier Peptid-Derivate mit S-Trityl-Schutzgruppen belegt. Als Nebenreaktion ist die Acetylierung von aliphatischen Hydroxylgruppen m{\"o}glich. Sie l{\"a}ßt sich vermeiden, wenn man die Spaltung in anderen L{\"o}sungsmitteln durchf{\"u}hrt. Die als Modellverbindungen f{\"u}r Stabilit{\"a}tsuntersuchungen verwendeten Nε-acylierten Lysin-Derivate werden mit dem Aminos{\"a}ureanalysator quantitativ neben Lysin bestimmt.}, language = {de} } @misc{FrauenrathdeGeyerd'OrthNiendorf2011, author = {Frauenrath, Tobias and de Geyer d'Orth, Thibaut and Niendorf, Thoralf}, title = {Assessment of Accuracy \& Reproducibility of ECG, Pulse Oximetry \& Phonocardiogram Gating of Cardiac MRI at 7T}, series = {2011 ISMRM Annual Meeting Proceedings}, journal = {2011 ISMRM Annual Meeting Proceedings}, issn = {1545-4428}, year = {2011}, abstract = {At (ultra)high magnetic fields the artifact sensitivity of ECG recordings increases. This bears the risk of R-wave mis-registration which has been consistently reported for ECG triggered CMR at 7.0T. Realizing the constraints of conventional ECG, acoustic cardiac triggering (ACT) has been proposed. The clinical ACT has not been carefully examined yet. For this reason, this work scrutinizes the suitability, accuracy and reproducibility of ACT for CMR at 7.0T. For this purpose, the trigger reliability and trigger detection variance are examined together with an qualitative and quantitative assessment of image quality of the heart at 7.0T.}, language = {en} } @article{KuropkaMuellerHoeckeretal.1989, author = {Kuropka, Rolf and M{\"u}ller, Bettina and H{\"o}cker, Hartwig and Berndt, Heinz}, title = {Chiral stationary phases via hydrosilylation reaction of N-acryloylamino acids : I. Stationary phase with one chiral centre for high-performance liquid chromatography and development of a new derivatization pattern for amino acid enantiomers}, series = {Journal of chromatography A}, journal = {Journal of chromatography A}, number = {481}, isbn = {0021-9673}, pages = {380 -- 386}, year = {1989}, language = {en} } @article{NokiharaBerndt1978, author = {Nokihara, Kiyoshi and Berndt, Heinz}, title = {Studies on sulfur-containing peptides : tert-butyloxycarbonylsulfenyl and benzyloxycarbonylsulfenyl derivatives as protecting groups for cysteine}, series = {The journal of organic chemistry}, volume = {43}, journal = {The journal of organic chemistry}, number = {25}, publisher = {American Chemical Society}, address = {Washington}, issn = {0022-3263}, doi = {10.1021/jo00419a046}, pages = {4893 -- 4895}, year = {1978}, language = {en} } @article{KalbeHoeckerBerndt1989, author = {Kalbe, Jochen and H{\"o}cker, Hartwig and Berndt, Heinz}, title = {Design of enzyme reactors as chromatographic columns for racemic resolution of amino acid esters}, series = {Chromatographia}, volume = {28}, journal = {Chromatographia}, number = {3-4}, isbn = {0009-5893}, doi = {10.1007/BF02319646}, pages = {193 -- 196}, year = {1989}, language = {en} } @inproceedings{HeineKnoblichBerndtetal.1993, author = {Heine, E. and Knoblich, M. and Berndt, Heinz and H{\"o}cker, Hartwig}, title = {Einsatz von {\"u}berkritischen Gasen insbesondere von {\"u}berkritischen CO2 als produktionsintegrierter Umweltschutz in der Wollindustrie}, series = {Qualit{\"a}t im Spannungsfeld von Forschung, Fertigung und Markt : Aachener Textiltagung = Aachen Textile Conference ; Aachen, 11./12. November 1992, Eurogress. - (DWI-Reports ; 111)}, booktitle = {Qualit{\"a}t im Spannungsfeld von Forschung, Fertigung und Markt : Aachener Textiltagung = Aachen Textile Conference ; Aachen, 11./12. November 1992, Eurogress. - (DWI-Reports ; 111)}, publisher = {Dt. Wollforschungsinst.}, address = {Aachen}, pages = {537 -- 549}, year = {1993}, language = {de} } @article{PeekenBennerPlatt1989, author = {Peeken, Heinz and Benner, Joachim and Platt, Werner}, title = {Ausfallkriterien elastomerbest{\"u}ckter Wellenkupplungen}, series = {Antriebstechnik : Konstruktion, Entwicklung und Anwendung von Antrieben und Steuerungen ; Organ der Forschungsvereinigung Antriebstechnik e.V.}, volume = {28}, journal = {Antriebstechnik : Konstruktion, Entwicklung und Anwendung von Antrieben und Steuerungen ; Organ der Forschungsvereinigung Antriebstechnik e.V.}, number = {11}, publisher = {Vereinigte Fachverl.}, address = {Mainz}, issn = {0341-2652}, pages = {85 -- 88}, year = {1989}, language = {de} } @book{Raatschen1986, author = {Raatschen, Hans-J{\"u}rgen}, title = {Ein Bicharakteristikenverfahren zur Berechnung von Spannungswellen in krummlinig berandeten Scheiben}, publisher = {RWTH Aachen}, address = {Aachen}, pages = {110 S. : Ill., graph. Darst.}, year = {1986}, language = {de} } @misc{FrauenrathFuchsHezeletal.2012, author = {Frauenrath, Tobias and Fuchs, Katharina and Hezel, Fabian and Dieringer, Matthias A. and Rieger, Jan and Niendorf, Thoralf}, title = {Improved cardiac triggering by combining multiple physiological signals: a cardiac MR feasibility study at 7.0 T}, series = {2012 ISMRM Annual Meeting Proceedings}, journal = {2012 ISMRM Annual Meeting Proceedings}, issn = {1545-4428}, year = {2012}, abstract = {In current clinical cardiovascular MR (CMR) practice cardiac motion is commonly dealt with using ECG based synchronization. However, ECG is corrupted by magneto-hydrodynamic (MHD) effects in magnetic fields. This leads to artifacts in the ECG trace and evokes severe T-wave elevations, which might be misinterpreted as R-waves resulting in erroneous triggering. At (ultra)high field strengths, the propensity of ECG recordings to MHD effects is further pronounced. Pulse oximetry (POX) being inherently sensitive to blood oxygenation provides an alternative approach for cardiac gating. However, due to the travel time of the blood the peak of maximum oxygenation and hence the trigger is delayed by approx. 300 ms with respect to the ECG's R-wave. Also the peak of maximum oxygenation shows a jitter of up to 65 ms. Alternative triggering approaches include acoustic cardiac triggering (ACT). In current clinical practice cardiac gating / triggering commonly relies on using single physiological signals only. Realizing this limitation this study proposes a combined triggering approach which exploits multiple physiological signals including ECG, POX or ACT to track cardiac activity. The feasibility of the coupled approach is examined for LV function assessment at 7.0 T. For this purpose, breath-held 2D-CINE imaging in conjunction with cardiac synchronization was performed paralleled by real time logging of physiological waveforms to track (mis)synchronization between the cardiac cycle and data acquisition. Combinations of the ECG, POX and ACT signals were evaluated and processed in real time to facilitate reliable trigger information.}, language = {en} }