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  - http://dx.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  - Neumaier, Felix
A1  - Weiss, Miriam
A1  - Veldeman, Michael
A1  - Kotliar, Konstantin
A1  - Wiesmann, Martin
A1  - Schulze-Steinen, Henna
A1  - Höllig, Anke
A1  - Clusmann, Hans
A1  - Schubert, Gerrit Alexander
A1  - Albanna, Walid
T1  - Changes in endogenous daytime melatonin levels after aneurysmal subarachnoid hemorrhage – preliminary findings from an observational cohort study
JF  - Clinical Neurology and Neurosurgery
N2  - Aneurysmal subarachnoid hemorrhage (aSAH) is associated with early and delayed brain injury due to several underlying and interrelated processes, which include inflammation, oxidative stress, endothelial, and neuronal apoptosis. Treatment with melatonin, a cytoprotective neurohormone with anti-inflammatory, anti-oxidant and anti-apoptotic effects, has been shown to attenuate early brain injury (EBI) and to prevent delayed cerebral vasospasm in experimental aSAH models. Less is known about the role of endogenous melatonin for aSAH outcome and how its production is altered by the pathophysiological cascades initiated during EBI. In the present observational study, we analyzed changes in melatonin levels during the first three weeks after aSAH.
KW  - constructive alignment
KW  - examination
KW  - long-term retention
KW  - multimodal
KW  - practical learning
Y1  - 2021
U6  - http://dx.doi.org/10.1016/j.clineuro.2021.106870
SN  - 0303-8467
VL  - 208
IS  - Article No.: 106870
PB  - Elsevier
CY  - Amsterdam
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  - http://dx.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  - Grieger, Niklas
A1  - Schwabedal, Justus T. C.
A1  - Wendel, Stefanie
A1  - Ritze, Yvonne
A1  - Bialonski, Stephan
T1  - Automated scoring of pre-REM sleep in mice with deep learning
JF  - Scientific Reports
N2  - Reliable automation of the labor-intensive manual task of scoring animal sleep can facilitate the analysis of long-term sleep studies. In recent years, deep-learning-based systems, which learn optimal features from the data, increased scoring accuracies for the classical sleep stages of Wake, REM, and Non-REM. Meanwhile, it has been recognized that the statistics of transitional stages such as pre-REM, found between Non-REM and REM, may hold additional insight into the physiology of sleep and are now under vivid investigation. We propose a classification system based on a simple neural network architecture that scores the classical stages as well as pre-REM sleep in mice. When restricted to the classical stages, the optimized network showed state-of-the-art classification performance with an out-of-sample F1 score of 0.95 in male C57BL/6J mice. When unrestricted, the network showed lower F1 scores on pre-REM (0.5) compared to the classical stages. The result is comparable to previous attempts to score transitional stages in other species such as transition sleep in rats or N1 sleep in humans. Nevertheless, we observed that the sequence of predictions including pre-REM typically transitioned from Non-REM to REM reflecting sleep dynamics observed by human scorers. Our findings provide further evidence for the difficulty of scoring transitional sleep stages, likely because such stages of sleep are under-represented in typical data sets or show large inter-scorer variability. We further provide our source code and an online platform to run predictions with our trained network.
Y1  - 2021
U6  - http://dx.doi.org/10.1038/s41598-021-91286-0
SN  - 2045-2322
N1  - Corresponding author: Stephan Bialonski
VL  - 11
IS  - Art. 12245
PB  - Springer Nature
CY  - London
ER  - 
TY  - JOUR
A1  - Ball, Christopher Stephen
A1  - Vögele, Stefan
A1  - Grajewski, Matthias
A1  - Kuckshinrichs, Wilhelm
T1  - E-mobility from a multi-actor point of view: Uncertainties and their impacts
JF  - Technological Forecasting and Social Change
Y1  - 2021
SN  - 0040-1625
U6  - http://dx.doi.org/10.1016/j.techfore.2021.120925
VL  - 170
IS  - Art. 120925
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Akimbekov, Nuraly
A1  - Digel, Ilya
A1  - Abdieva, Gulzhamal
A1  - Ualieva, Perizat
A1  - Tastambek, Kuanysh
T1  - Lignite biosolubilization and bioconversion by Bacillus sp.: the collation of analytical data
JF  - Biofuels
N2  - The vast metabolic potential of microbes in brown coal (lignite) processing and utilization can greatly contribute to innovative approaches to sustainable production of high-value products from coal. In this study, the multi-faceted and complex coal biosolubilization process by Bacillus sp. RKB 7 isolate from the Kazakhstan coal-mining soil is reported, and the derived products are characterized. Lignite solubilization tests performed for surface and suspension cultures testify to the formation of numerous soluble lignite-derived substances. Almost 24% of crude lignite (5% w/v) was solubilized within 14 days under slightly alkaline conditions (pH 8.2). FTIR analysis revealed various functional groups in the obtained biosolubilization products. Analyses of the lignite-derived humic products by UV-Vis and fluorescence spectrometry as well as elemental analysis yielded compatible results indicating the emerging products had a lower molecular weight and degree of aromaticity. Furthermore, XRD and SEM analyses were used to evaluate the biosolubilization processes from mineralogical and microscopic points of view. The findings not only contribute to a deeper understanding of microbe–mineral interactions in coal environments, but also contribute to knowledge of coal biosolubilization and bioconversion with regard to sustainable production of humic substances. The detailed and comprehensive analyses demonstrate the huge biotechnological potential of Bacillus sp. for agricultural productivity and environmental health.
KW  - humic acid
KW  - Bacillus sp
KW  - lignite
KW  - Biosolubilization
Y1  - 2021
SN  - 1759-7277
VL  - 12
IS  - 3
SP  - 247
EP  - 258
PB  - Taylor & Francis
CY  - London
ER  - 
TY  - JOUR
A1  - Jildeh, Zaid B.
A1  - Wagner, Patrick H.
A1  - Schöning, Michael Josef
T1  - Sterilization of Objects, Products, and Packaging Surfaces and Their Characterization in Different Fields of Industry: The Status in 2020
JF  - physica status solidi (a) applications and materials science
N2  - The treatment method to deactivate viable microorganisms from objects or products is termed sterilization. There are multiple forms of sterilization, each intended to be applied for a specific target, which depends on—but not limited to—the thermal, physical, and chemical stability of that target. Herein, an overview on the currently used sterilization processes in the global market is provided. Different sterilization techniques are grouped under a category that describes the method of treatment: radiation (gamma, electron beam, X-ray, and ultraviolet), thermal (dry and moist heat), and chemical (ethylene oxide, ozone, chlorine dioxide, and hydrogen peroxide). For each sterilization process, the typical process parameters as defined by regulations and the mode of antimicrobial activity are summarized. Finally, the recommended microorganisms that are used as biological indicators to validate sterilization processes in accordance with the rules that are established by various regulatory agencies are summarized.
KW  - bioburdens
KW  - sterility tests
KW  - sterilization efficacy
KW  - sterilization methods
KW  - validation methods
Y1  - 2021
U6  - http://dx.doi.org/10.1002/pssa.202000732
SN  - 1862-6319
N1  - Corresponding author: Michael J. Schöning
VL  - 218
IS  - 13
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Molinnus, Denise
A1  - Drinic, Aleksander
A1  - Iken, Heiko
A1  - Kröger, Nadja
A1  - Zinser, Max
A1  - Smeets, Ralf
A1  - Köpf, Marius
A1  - Kopp, Alexander
A1  - Schöning, Michael Josef
T1  - Towards a flexible electrochemical biosensor fabricated from biocompatible Bombyx mori silk
JF  - Biosensors and Bioelectronics
Y1  - 2021
U6  - http://dx.doi.org/10.1016/j.bios.2021.113204
SN  - 0956-5663
VL  - 183
IS  - Art. 113204
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Wert, Stefan
A1  - Iken, Heiko
A1  - Schöning, Michael Josef
A1  - Matysik, Frank-Michael
T1  - Development of a temperature‐pulse enhanced electrochemical glucose biosensor and characterization of its stability via scanning electrochemical microscopy
JF  - Electroanalysis
N2  - Glucose oxidase (GOx) is an enzyme frequently used in glucose biosensors. As increased temperatures can enhance the performance of electrochemical sensors, we investigated the impact of temperature pulses on GOx that was drop-coated on flattened Pt microwires. The wires were heated by an alternating current. The sensitivity towards glucose and the temperature stability of GOx was investigated by amperometry. An up to 22-fold increase of sensitivity was observed. Spatially resolved enzyme activity changes were investigated via scanning electrochemical microscopy. The application of short (<100 ms) heat pulses was associated with less thermal inactivation of the immobilized GOx than long-term heating.
Y1  - 2021
U6  - http://dx.doi.org/10.1002/elan.202100089
SN  - 1521-4109
IS  - Early View
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Waldvogel, Janice
A1  - Ritzmann, Ramona
A1  - Freyler, Kathrin
A1  - Helm, Michael
A1  - Monti, Elena
A1  - Albracht, Kirsten
A1  - Stäudle, Benjamin
A1  - Gollhofer, Albert
A1  - Narici, Marco
T1  - The Anticipation of Gravity in Human Ballistic Movement
JF  - Frontiers in Physiology
N2  - Stretch-shortening type actions are characterized by lengthening of the pre-activated muscle-tendon unit (MTU) in the eccentric phase immediately followed by muscle shortening. Under 1 g, pre-activity before and muscle activity after ground contact, scale muscle stiffness, which is crucial for the recoil properties of the MTU in the subsequent push-off. This study aimed to examine the neuro-mechanical coupling of the stretch-shortening cycle in response to gravity levels ranging from 0.1 to 2 g. During parabolic flights, 17 subjects performed drop jumps while electromyography (EMG) of the lower limb muscles was combined with ultrasound images of the gastrocnemius medialis, 2D kinematics and kinetics to depict changes in energy management and performance. Neuro-mechanical coupling in 1 g was characterized by high magnitudes of pre-activity and eccentric muscle activity allowing an isometric muscle behavior during ground contact. EMG during pre-activity and the concentric phase systematically increased from 0.1 to 1 g. Below 1 g the EMG in the eccentric phase was diminished, leading to muscle lengthening and reduced MTU stretches. Kinetic energy at take-off and performance were decreased compared to 1 g. Above 1 g, reduced EMG in the eccentric phase was accompanied by large MTU and muscle stretch, increased joint flexion amplitudes, energy loss and reduced performance. The energy outcome function established by linear mixed model reveals that the central nervous system regulates the extensor muscles phase- and load-specifically. In conclusion, neuro-mechanical coupling appears to be optimized in 1 g. Below 1 g, the energy outcome is compromised by reduced muscle stiffness. Above 1 g, loading progressively induces muscle lengthening, thus facilitating energy dissipation.
Y1  - 2021
U6  - http://dx.doi.org/10.3389/fphys.2021.614060
SN  - 1664-042X
PB  - Frontiers
CY  - Lausanne
ER  -