TY  - JOUR
A1  - Conzen, Catharina
A1  - Albanna, Walid
A1  - Weiss, Miriam
A1  - Kürten, David
A1  - Vilser, Walthard
A1  - Kotliar, Konstantin
A1  - Zäske, Charlotte
A1  - Clusmann, Hans
A1  - Schubert, Gerrit Alexander
T1  - Vasoconstriction and Impairment of Neurovascular Coupling after Subarachnoid Hemorrhage: a Descriptive Analysis of Retinal Changes
JF  - Translational Stroke Research
N2  - Impaired cerebral autoregulation and neurovascular coupling (NVC) contribute to delayed cerebral ischemia after subarachnoid hemorrhage (SAH). Retinal vessel analysis (RVA) allows non-invasive assessment of vessel dimension and NVC hereby demonstrating a predictive value in the context of various neurovascular diseases. Using RVA as a translational approach, we aimed to assess the retinal vessels in patients with SAH. RVA was performed prospectively in 24 patients with acute SAH (group A: day 5–14), in 11 patients 3 months after ictus (group B: day 90 ± 35), and in 35 age-matched healthy controls (group C). Data was acquired using a Retinal Vessel Analyzer (Imedos Systems UG, Jena) for examination of retinal vessel dimension and NVC using flicker-light excitation. Diameter of retinal vessels—central retinal arteriolar and venular equivalent—was significantly reduced in the acute phase (p < 0.001) with gradual improvement in group B (p < 0.05). Arterial NVC of group A was significantly impaired with diminished dilatation (p < 0.001) and reduced area under the curve (p < 0.01) when compared to group C. Group B showed persistent prolonged latency of arterial dilation (p < 0.05). Venous NVC was significantly delayed after SAH compared to group C (A p < 0.001; B p < 0.05). To our knowledge, this is the first clinical study to document retinal vasoconstriction and impairment of NVC in patients with SAH. Using non-invasive RVA as a translational approach, characteristic patterns of compromise were detected for the arterial and venous compartment of the neurovascular unit in a time-dependent fashion. Recruitment will continue to facilitate a correlation analysis with clinical course and outcome.
Y1  - 2018
U6  - https://doi.org/10.1007/s12975-017-0585-8
SN  - 1868-601X
IS  - 9
SP  - 284
EP  - 293
PB  - Springer Nature
CY  - Cham
ER  - 
TY  - JOUR
A1  - Bernecker, Andreas
A1  - Boyer, Pierre C.
A1  - Gathmann, Christina
T1  - The Role of Electoral Incentives for Policy Innovation: Evidence from the US Welfare Reform
JF  - American Economic Journal: Economic Policy
Y1  - 2021
U6  - https://doi.org/10.1257/pol.20190690
SN  - 1945-774X
VL  - 13
IS  - 2
SP  - 26
EP  - 57
PB  - American Economic Association
CY  - Nashville, Tenn.
ER  - 
TY  - JOUR
A1  - Hugenroth, Kristin
A1  - Borchardt, Ralf
A1  - Ritter, Philine
A1  - Groß‑Hardt, Sascha
A1  - Meyns, Bart
A1  - Verbelen, Tom
A1  - Steinseifer, Ulrich
A1  - Kaufmann, Tim A. S.
A1  - Engelmann, Ulrich M.
T1  - Optimizing cerebral perfusion and hemodynamics during cardiopulmonary bypass through cannula design combining in silico, in vitro and in vivo input
JF  - Scientific Reports
N2  - Cardiopulmonary bypass (CPB) is a standard technique for cardiac surgery, but comes with the risk of severe neurological complications (e.g. stroke) caused by embolisms and/or reduced cerebral perfusion. We report on an aortic cannula prototype design (optiCAN) with helical outflow and jet-splitting dispersion tip that could reduce the risk of embolic events and restores cerebral perfusion to 97.5% of physiological flow during CPB in vivo, whereas a commercial curved-tip cannula yields 74.6%. In further in vitro comparison, pressure loss and hemolysis parameters of optiCAN remain unaffected. Results are reproducibly confirmed in silico for an exemplary human aortic anatomy via computational fluid dynamics (CFD) simulations. Based on CFD simulations, we firstly show that optiCAN design improves aortic root washout, which reduces the risk of thromboembolism. Secondly, we identify regions of the aortic intima with increased risk of plaque release by correlating areas of enhanced plaque growth and high wall shear stresses (WSS). From this we propose another easy-to-manufacture cannula design (opti2CAN) that decreases areas burdened by high WSS, while preserving physiological cerebral flow and favorable hemodynamics. With this novel cannula design, we propose a cannulation option to reduce neurological complications and the prevalence of stroke in high-risk patients after CPB.
Y1  - 2021
U6  - https://doi.org/10.1038/s41598-021-96397-2
SN  - 2045-2322
VL  - 11
IS  - Art. No. 16800
SP  - 1
EP  - 12
PB  - Springer
CY  - Berlin
ER  - 
TY  - JOUR
A1  - Brockhaus, Moritz K.
A1  - Behbahani, Mehdi
A1  - Muris, Farina
A1  - Jansen, Sebastian V.
A1  - Schmitz- Rode, Thomas
A1  - Steinseifer, Ulrich
A1  - Clauser, Johanna C.
T1  - In vitro thrombogenicity testing of pulsatile mechanical circulatory support systems: Design and proof-of-concept
JF  - Artificial Organs
N2  - 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.
Y1  - 2021
U6  - https://doi.org/10.1111/aor.14046
SN  - 1525-1594
VL  - 45
IS  - 12
SP  - 1513
EP  - 1521
PB  - Wiley
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Arampatzis, Adamantios
A1  - Karamanidis, Kiros
A1  - Albracht, Kirsten
T1  - Adaptational responses of the human Achilles tendon by modulation of the applied cyclic strain magnitude
JF  - Journal of Experimental Biology
Y1  - 2007
U6  - https://doi.org/10.1242/jeb.003814
SN  - 0022-0949
VL  - 210
IS  - 15
SP  - 2743
EP  - 2753
ER  - 
TY  - JOUR
A1  - Albracht, Kirsten
A1  - Arampatzis, Adamantios
T1  - Influence of the mechanical properties of the muscle-tendon unit on force generation in runners with different running economy
JF  - Biological Cybernetics
Y1  - 2006
U6  - https://doi.org/10.1007/s00422-006-0070-z
SN  - 1432-0770
VL  - 95
IS  - 1
SP  - 87
EP  - 96
ER  - 
TY  - JOUR
A1  - Sousa, Marcos A. M.
A1  - Siqueira, Jose R. Jr.
A1  - Vercik, Andres
A1  - Schöning, Michael Josef
A1  - Oliveira, Osvaldo N. Jr.
T1  - Determining the optimized layer-by-layer film architecture with dendrimer/carbon nanotubes for field-effect sensors
JF  - IEEE Sensors Journal
N2  - The capacitive electrolyte–insulator–semiconductor (EIS) structure is a typical device based on a field-effect sensor platform. With a simple silicon-based structure, EIS have been useful for several sensing applications, especially with incorporation of nanostructured films to modulate the ionic transport and the flat-band potential. In this paper, we report on ion transport and changes in flat-band potential in EIS sensors made with layer-by-layer films containing poly(amidoamine) (PAMAM) dendrimer and single-walled carbon nanotubes (SWNTs) adsorbed on p-Si/SiO 2 /Ta 2 O 5 chips with an Al ohmic contact. The impedance spectra were fitted using an equivalent circuit model, from which we could determine parameters such as the double-layer capacitance. This capacitance decreased with the number of bilayers owing to space charge accumulated at the electrolyte–insulator interface, up to three PAMAM/SWNTs bilayers, after which it stabilized. The charge-transfer resistance was also minimum for three bilayers, thus indicating that this is the ideal architecture for an optimized EIS performance. The understanding of the influence of nanostructures and the fine control of operation parameters pave the way for optimizing the design and performance of new EIS sensors.
Y1  - 2017
U6  - https://doi.org/10.1109/JSEN.2017.2653238
SN  - 1558-1748
VL  - 17
IS  - 6
SP  - 1735
EP  - 1740
PB  - IEEE
CY  - New York
ER  - 
TY  - JOUR
A1  - Reinhardt, T.
A1  - Bitz, Andreas
A1  - El Ouardi, A.
A1  - Streckert, J.
A1  - Sommer, A.
A1  - Lerchl, A.
A1  - Hansen, V.
T1  - Exposure set-ups for in vivo experiments using radial waveguides
JF  - Radiation Protection Dosimetry
Y1  - 2007
U6  - https://doi.org/10.1093/rpd/ncm370
SN  - 1742-3406
VL  - 124
IS  - 1
SP  - 21
EP  - 26
ER  - 
TY  - JOUR
A1  - Sommer, Angela M.
A1  - Bitz, Andreas
A1  - Streckert, Joachim
A1  - Hansen, Volkert W.
A1  - Lerchl, Alexander
T1  - Lymphoma development in mice chronically exposed to UMTS-modulated radiofrequency electromagnetic fields
JF  - Radiation Research
Y1  - 2007
U6  - https://doi.org/10.1667/RR0857.1
SN  - 1938-5404
VL  - 168
IS  - 1
SP  - 72
EP  - 80
ER  - 
TY  - JOUR
A1  - Sukhotina, Irina
A1  - Streckert, Joachim R.
A1  - Bitz, Andreas
A1  - Hansen, Volkert W.
A1  - Lerchl, Alexander
T1  - 1800 MHz electromagnetic field effects on melatonin release from isolated pineal glands
JF  - Journal of Pineal Research
Y1  - 2006
U6  - https://doi.org/10.1111/j.1600-079X.2005.00284.x
SN  - 1600-079X
VL  - 40
IS  - 1
SP  - 86
EP  - 91
ER  - 
TY  - JOUR
A1  - Franke, Helmut
A1  - Streckert, Joachim
A1  - Bitz, Andreas
A1  - Goeke, Johannes
A1  - Hansen, Volkert
A1  - Ringelstein, E. Bernd
A1  - Nattkämper, Heiner
A1  - Galle, Hans-Joachim
A1  - Stögbauer, Florian
T1  - Effects of Universal Mobile Telecommunications System (UMTS) electromagnetic fields on the blood-brain barrier in vitro
JF  - Radiation Research
Y1  - 2005
U6  - https://doi.org/10.1667/RR3424.1
SN  - 1938-5404
VL  - 164
IS  - 3
SP  - 258
EP  - 269
ER  - 
TY  - JOUR
A1  - Wissen, M.
A1  - Bogdanski, N.
A1  - Scheer, H.-C.
A1  - Bitz, Andreas
A1  - Ahrens, G.
A1  - Gruetzner, G.
T1  - Implication of the light polarisation for UV curing of pre-patterned resists
JF  - Microelectronic Engineering
Y1  - 2005
U6  - https://doi.org/10.1016/j.mee.2004.12.099
SN  - 0167-9317
VL  - 78-79
SP  - 659
EP  - 664
ER  - 
TY  - JOUR
A1  - Ndoumbè Mbonjo Mbonjo, H.
A1  - Streckert, J.
A1  - Bitz, Andreas
A1  - Hansen, V.
A1  - Glasmachers, A.
A1  - Gencol, S.
A1  - Rozic, D.
T1  - Generic UMTS test signal for RF bioelectromagnetic studies
JF  - Bioelectromagnetics
Y1  - 2004
U6  - https://doi.org/10.1002/bem.20007
SN  - 1521-186X
VL  - 25
IS  - 6
SP  - 415
EP  - 425
ER  - 
TY  - JOUR
A1  - Sommer, Angela M.
A1  - Streckert, Joachim
A1  - Bitz, Andreas
A1  - Hansen, Volkert W.
A1  - Lerchl, Alexander
T1  - No effects of GSM-modulated 900 MHz electromagnetic fields on survival rate and spontaneous development of lymphoma in female AKR/J mice
JF  - BMC Cancer
Y1  - 2004
U6  - https://doi.org/10.1186/1471-2407-4-77
VL  - 77
IS  - 4
ER  - 
TY  - JOUR
A1  - Hansen, Volkert W.
A1  - Bitz, Andreas
A1  - Streckert, Joachim R.
T1  - RF Exposure of Biological Systems in Radial Waveguides
JF  - IEEE Transactions on Electromagnetic Compatibility
Y1  - 1999
U6  - https://doi.org/10.1109/15.809852
SN  - 1558-187X
VL  - 41
IS  - 4
SP  - 487
EP  - 493
ER  - 
TY  - JOUR
A1  - Arreola, Julio
A1  - Oberländer, Jan
A1  - Mätzkow, M.
A1  - Keusgen, Michael
A1  - Schöning, Michael Josef
T1  - Surface functionalization for spore-based biosensors with organosilanes
JF  - Electrochimica Acta
N2  - In the present work, surface functionalization of different sensor materials was studied. Organosilanes are well known to serve as coupling agent for biomolecules or cells on inorganic materials. 3-aminopropyltriethoxysilane (APTES) was used to attach microbiological spores time to an interdigitated sensor surface. The functionality and physical properties of APTES were studied on isolated sensor materials, namely silicon dioxide (SiO2) and platinum (Pt) as well as the combined material on sensor level. A predominant immobilization of spores could be demonstrated on SiO2 surfaces. Additionally, the impedance signal of APTES-functionalized biosensor chips has been investigated.
Y1  - 2017
U6  - https://doi.org/10.1016/j.electacta.2017.04.157
SN  - 0013-4686
VL  - 241
SP  - 237
EP  - 243
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Rieke, Christian
A1  - Stollenwerk, Dominik
A1  - Dahmen, Markus
A1  - Pieper, Martin
T1  - Modeling and optimization of a biogas plant for a demand-driven energy supply
JF  - Energy
N2  - Due to the Renewable Energy Act, in Germany it is planned to increase the amount of renewable energy carriers up to 60%. One of the main problems is the fluctuating supply of wind and solar energy. Here biogas plants provide a solution, because a demand-driven supply is possible. Before running such a plant, it is necessary to simulate and optimize the process. This paper provides a new model of a biogas plant, which is as accurate as the standard ADM1 model. The advantage compared to ADM1 is that it is based on only four parameters compared to 28. Applying this model, an optimization was installed, which allows a demand-driven supply by biogas plants. Finally the results are confirmed by several experiments and measurements with a real test plant.
Y1  - 2018
U6  - https://doi.org/10.1016/j.energy.2017.12.073
SN  - 0360-5442
VL  - 145
SP  - 657
EP  - 664
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Oberländer, Jan
A1  - Mayer, Marlena
A1  - Greeff, Anton
A1  - Keusgen, Michael
A1  - Schöning, Michael Josef
T1  - Spore-based biosensor to monitor the microbicidal efficacy of gaseous hydrogen peroxide sterilization processes
JF  - Biosensors and Bioelectronics
N2  - In this work, a spore-based biosensor is evaluated to monitor the microbicidal efficacy of sterilization processes applying gaseous hydrogen peroxide (H2O2). The sensor is based on interdigitated electrode structures (IDEs) that have been fabricated by means of thin-film technologies. Impedimetric measurements are applied to study the effect of sterilization process on spores of Bacillus atrophaeus. This resilient microorganism is commonly used in industry to proof the sterilization efficiency. The sensor measurements are accompanied by conventional microbiological challenge tests, as well as morphological characterizations with scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The sensor measurements are correlated with the microbiological test routines. In both methods, namely the sensor-based and microbiological one, a tailing effect has been observed. The results are evaluated and discussed in a three-dimensional calibration plot demonstrating the sensor's suitability to enable a rapid process decision in terms of a successfully performed sterilization.
Y1  - 2018
U6  - https://doi.org/10.1016/j.bios.2017.12.045
SN  - 0956-5663
VL  - 104
SP  - 87
EP  - 94
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Braband, Henrik
A1  - Paulßen, Elisabeth
A1  - Abram, Ulrich
T1  - Nitridorhenium(V) Complexes with 1,3-Dialkyl-4,5-dimethylimidazole-2-ylidenes
JF  - Zeitschrift für anorganische und allgemeine Chemie : ZAAC = Journal of inorganic and general chemistry
Y1  - 2006
U6  - https://doi.org/10.1002/zaac.200600002
SN  - 1521-3749
VL  - 632
IS  - 6
SP  - 1051
EP  - 1056
ER  - 
TY  - JOUR
A1  - Paulßen, Elisabeth
A1  - Schweighöfer, Philip V.
A1  - Abram, Ulrich
T1  - Reactions of [ReOX3(PPh3)2] Complexes (X = Cl, Br) with Phenylacetylene and the Structures of the Products
JF  - Zeitschrift für anorganische und allgemeine Chemie : ZAAC = Journal of inorganic and general chemistry
N2  - Oxorhenium(V) complexes [ReOX3(PPh3)2] (X = Cl, Br) react with phenylacetylene under formation of complexes with ylide-type ligands. Compounds of the compositions [ReOCl3(PPh3){C(Ph)C(H)(PPh3)}] (1), [ReOBr3(OPPh3){C(Ph)C(H)(PPh3)}] (2), and [ReOBr3(OPPh3){C(H)C(Ph)(PPh3)}] (3) were isolated and characterized by X-ray diffraction. They contain a ligand, which was formed by a nucleophilic attack of released PPh3 at coordinated phenylacetylene. The structures of the products show that there is no preferable position for this attack. Cleavage of the Re–C bond in 3 and dimerization of the organic ligand resulted in the formation of the [{(PPh3)(H)CC(Ph)}2]2+ cation, which crystallized as its [(ReOBr4)(OReO3)]2– salt.
Y1  - 2010
U6  - https://doi.org/10.1002/zaac.200900478
SN  - 1521-3749
VL  - 636
IS  - 5
SP  - 779
EP  - 783
PB  - Wiley-VCH
CY  - Weinheim
ER  -