TY  - JOUR
A1  - Müller-Veggian, Mattea
T1  - Investigation of the preequilibrium reaction mechanism through the study of the isomer ratios ²¹¹,²¹² Po
JF  - Annual report 1979 / Kernforschungsanlage Jülich Institut für Kernphysik / Hrsg.: A. Fässler. - (Spezielle Berichte der Kernforschungsanlage Jülich ; 72)
Y1  - 1980
SP  - 32
PB  - Verlag des Forschungszentrums Jülich
CY  - Jülich
ER  - 
TY  - JOUR
A1  - Müller-Veggian, Mattea
T1  - High-spin level structure of ¹³³ La
JF  - Annual report 1981 / Kernforschungsanlage Jülich Institut für Kernphysik / Hrsg.: F. Grümmer. - (Spezielle Berichte der Kernforschungsanlage Jülich ; 146)
Y1  - 1982
SP  - 51
PB  - Kernforschungsanlage
CY  - Jülich
ER  - 
TY  - JOUR
A1  - Müller, Wolfram
A1  - Jung, Alexander
A1  - Ahammer, Helmut
T1  - Advantages and problems of nonlinear methods applied to analyze physiological time signals: human balance control as an example
JF  - Scientific Reports
Y1  - 2017
SN  - 2045-2322
U6  - http://dx.doi.org/10.1038/s41598-017-02665-5
VL  - 7
IS  - Article number 2464
SP  - 1
EP  - 11
PB  - Springer Nature
CY  - Cham
ER  - 
TY  - JOUR
A1  - Müller, Martin
A1  - Hirschfeld, Julian
A1  - Lambertz, Rita
A1  - Schulze Lohoff, Andreas
A1  - Lustfeld, Hans
A1  - Pfeifer, Heinz
A1  - Reißel, Martin
T1  - Validation of a novel method for detecting and stabilizing malfunctioning areas in fuel cell stacks
JF  - Journal of power sources
N2  - In this paper a setup for detecting malfunctioning areas of MEAs in fuel cell stacks is described. Malfunctioning areas generate electric cross currents inside bipolar plates. To exploit this we suggest bipolar plates consisting not of two but of three layers. The third one is a highly conducting layer and segmented such that the cross currents move along the segments to the surface of the stack where they can be measured by an inductive sensor. With this information a realistic model can be used to detect the malfunctioning area. Furthermore the third layer will prevent any current inhomogeneity of a malfunctioning cell to spread to neighbouring cells in the stack. In this work the results of measurements in a realistic cell setup will be compared with the results obtained in simulation studies with the same configuration. The basis for the comparison is the reliable characterisation of the electrical properties of the cell components and the implication of these results into the simulation model. The experimental studies will also show the limits in the maximum number of segments, which can be used for a reliable detection of cross currents.
Y1  - 2014
U6  - http://dx.doi.org/10.1016/j.jpowsour.2014.08.045
SN  - 1873-2755 (E-Journal); 0378-7753 (Print)
VL  - 272
SP  - 225
EP  - 232
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Musholt, Petra B.
A1  - Schöndorf, Thomas
A1  - Pfützner, Andreas
A1  - Hohberg, Cloth
A1  - Kleine, Iris
A1  - Fuchs, Winfried
A1  - Hehenwarter, Silvia
A1  - Dikta, Gerhard
A1  - Kerschgens, Benedikt
A1  - Forst, Thomas
T1  - Combined Pioglitazone and Metformin Treatment Maintains the Beneficial Effect of Short-Term Insulin Infusion in Patients with Type 2 Diabetes: Results from a Pilot Study
JF  - Journal of Diabetes Science and Technology. 3 (2009), H. 6
Y1  - 2009
SN  - 1932-2968
SP  - 1442
EP  - 1450
PB  - Sage Publishing
CY  - London
ER  - 
TY  - JOUR
A1  - Muschallik, Lukas
A1  - Molinnus, Denise
A1  - Jablonski, Melanie
A1  - Kipp, Carina Ronja
A1  - Bongaerts, Johannes
A1  - Pohl, Martina
A1  - Wagner, Torsten
A1  - Schöning, Michael Josef
A1  - Selmer, Thorsten
A1  - Siegert, Petra
T1  - Synthesis of α-hydroxy ketones and vicinal (R, R)-diols by Bacillus clausii DSM 8716ᵀ butanediol dehydrogenase
JF  - RSC Advances
N2  - α-hydroxy ketones (HK) and 1,2-diols are important building blocks for fine chemical synthesis. Here, we describe the R-selective 2,3-butanediol dehydrogenase from B. clausii DSM 8716ᵀ (BcBDH) that belongs to the metal-dependent medium chain dehydrogenases/reductases family (MDR) and catalyzes the selective asymmetric reduction of prochiral 1,2-diketones to the corresponding HK and, in some cases, the reduction of the same to the corresponding 1,2-diols. Aliphatic diketones, like 2,3-pentanedione, 2,3-hexanedione, 5-methyl-2,3-hexanedione, 3,4-hexanedione and 2,3-heptanedione are well transformed. In addition, surprisingly alkyl phenyl dicarbonyls, like 2-hydroxy-1-phenylpropan-1-one and phenylglyoxal are accepted, whereas their derivatives with two phenyl groups are not substrates. Supplementation of Mn²⁺ (1 mM) increases BcBDH's activity in biotransformations. Furthermore, the biocatalytic reduction of 5-methyl-2,3-hexanedione to mainly 5-methyl-3-hydroxy-2-hexanone with only small amounts of 5-methyl-2-hydroxy-3-hexanone within an enzyme membrane reactor is demonstrated.
Y1  - 2020
U6  - http://dx.doi.org/10.1039/D0RA02066D
SN  - 2046-2069
VL  - 10
SP  - 12206
EP  - 12216
PB  - Royal Society of Chemistry (RSC)
CY  - Cambridge
ER  - 
TY  - JOUR
A1  - Muschallik, Lukas
A1  - Molinnus, Denise
A1  - Bongaerts, Johannes
A1  - Pohl, Martina
A1  - Wagner, Torsten
A1  - Schöning, Michael Josef
A1  - Siegert, Petra
A1  - Selmer, Thorsten
T1  - (R,R)-Butane-2,3-diol Dehydrogenase from Bacillus clausii DSM 8716T: Cloning and Expression of the bdhA-Gene, and Initial Characterization of Enzyme
JF  - Journal of Biotechnology
N2  - The gene encoding a putative (R,R)-butane-2,3-diol dehydrogenase (bdhA) from Bacillus clausii DSM 8716T was isolated, sequenced and expressed in Escherichia coli. The amino acid sequence of the encoded protein is only distantly related to previously studied enzymes (identity 33–43%) and exhibited some uncharted peculiarities. An N-terminally StrepII-tagged enzyme variant was purified and initially characterized. The isolated enzyme catalyzed the (R)-specific oxidation of (R,R)- and meso-butane-2,3-diol to (R)- and (S)-acetoin with specific activities of 12 U/mg and 23 U/mg, respectively. Likewise, racemic acetoin was reduced with a specific activity of up to 115 U/mg yielding a mixture of (R,R)- and meso-butane-2,3-diol, while the enzyme reduced butane-2,3-dione (Vmax 74 U/mg) solely to (R,R)-butane-2,3-diol via (R)-acetoin. For these reactions only activity with the co-substrates NADH/NAD+ was observed. The enzyme accepted a selection of vicinal diketones, α-hydroxy ketones and vicinal diols as alternative substrates. Although the physiological function of the enzyme in B. clausii remains elusive, the data presented herein clearly demonstrates that the encoded enzyme is a genuine (R,R)-butane-2,3-diol dehydrogenase with potential for applications in biocatalysis and sensor development.
Y1  - 2017
U6  - http://dx.doi.org/10.1016/j.jbiotec.2017.07.020
SN  - 0168-1656
VL  - 258
SP  - 41
EP  - 50
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Muschallik, Lukas
A1  - Kipp, Carina Ronja
A1  - Recker, Inga
A1  - Bongaerts, Johannes
A1  - Pohl, Martina
A1  - Gelissen, Melanie
A1  - Schöning, Michael Josef
A1  - Selmer, Thorsten
A1  - Siegert, Petra
T1  - Synthesis of α-hydroxy ketones and vicinal diols with the Bacillus licheniformis DSM 13T butane-2, 3-diol dehydrogenase
JF  - Journal of Biotechnology
N2  - The enantioselective synthesis of α-hydroxy ketones and vicinal diols is an intriguing field because of the broad applicability of these molecules. Although, butandiol dehydrogenases are known to play a key role in the production of 2,3-butandiol, their potential as biocatalysts is still not well studied. Here, we investigate the biocatalytic properties of the meso-butanediol dehydrogenase from Bacillus licheniformis DSM 13T (BlBDH). The encoding gene was cloned with an N-terminal StrepII-tag and recombinantly overexpressed in E. coli. BlBDH is highly active towards several non-physiological diketones and α-hydroxyketones with varying aliphatic chain lengths or even containing phenyl moieties. By adjusting the reaction parameters in biotransformations the formation of either the α-hydroxyketone intermediate or the diol can be controlled.
Y1  - 2020
SN  - 2590-1559
U6  - http://dx.doi.org/10.1016/j.jbiotec.2020.09.016
VL  - 202
IS  - Vol. 324
SP  - 61
EP  - 70
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Murib, Mohammed Sharif
A1  - Yeap, Weng-Siang
A1  - Martens, Daan
A1  - Bienstman, Peter
A1  - Ceuninck, Ward de
A1  - Grinsven, Bart van
A1  - Schöning, Michael Josef
A1  - Michiels, Luc
A1  - Haenen, Ken
A1  - Ameloot, Marcel
A1  - Serpengüzel, Ali
A1  - Wagner, Patrick
T1  - Photonic detection and characterization of DNA using sapphire microspheres
JF  - Journal of biomedical optics
N2  - A microcavity-based deoxyribonucleic acid (DNA) optical biosensor is demonstrated for the first time using synthetic sapphire for the optical cavity. Transmitted and elastic scattering intensity at 1510 nm are analyzed from a sapphire microsphere (radius 500  μm, refractive index 1.77) on an optical fiber half coupler. The 0.43 nm angular mode spacing of the resonances correlates well with the optical size of the sapphire sphere. Probe DNA consisting of a 36-mer fragment was covalently immobilized on a sapphire microsphere and hybridized with a 29-mer target DNA. Whispering gallery modes (WGMs) were monitored before the sapphire was functionalized with DNA and after it was functionalized with single-stranded DNA (ssDNA) and double-stranded DNA (dsDNA). The shift in WGMs from the surface modification with DNA was measured and correlated well with the estimated thickness of the add-on DNA layer. It is shown that ssDNA is more uniformly oriented on the sapphire surface than dsDNA. In addition, it is shown that functionalization of the sapphire spherical surface with DNA does not affect the quality factor (Q≈104) of the sapphire microspheres. The use of sapphire is especially interesting because this material is chemically resilient, biocompatible, and widely used for medical implants.
Y1  - 2014
U6  - http://dx.doi.org/10.1117/1.JBO.19.9.097006
SN  - 1560-2281 (E-Journal); 1083-3668 (Print)
VL  - 19
IS  - 9
SP  - 097006
PB  - SPIE
CY  - Bellingham
ER  - 
TY  - JOUR
A1  - Murib, Mohammed S.
A1  - Tran, Anh Quang
A1  - Ceuninck, Ward de
A1  - Schöning, Michael Josef
A1  - Nesladek, Milos
A1  - Serpengüzel, Ali
A1  - Wagner, Patrick
T1  - Analysis of an optical biosensor based on elastic light scattering from diamond-, glass-, and sapphire microspheres
JF  - Physica Status Solidi A
N2  - Deoxyribonucleic acid (DNA) and protein recognition are now standard tools in biology. In addition, the special optical properties of microsphere resonators expressed by the high quality factor (Q-factor) of whispering gallery modes (WGMs) or morphology dependent resonances (MDRs) have attracted the attention of the biophotonic community. Microsphere-based biosensors are considered as powerful candidates to achieve label-free recognition of single molecules due to the high sensitivity of their WGMs. When the microsphere surface is modified with biomolecules, the effective refractive index and the effective size of the microsphere change resulting in a resonant wavelength shift. The transverse electric (TE) and the transverse magnetic (TM) elastic light scattering intensity of electromagnetic waves at 600 and 1400 nm are numerically calculated for DNA and unspecific binding of proteins to the microsphere surface. The effect of changing the optical properties was studied for diamond (refractive index 2.34), glass (refractive index 1.50), and sapphire (refractive index 1.75) microspheres with a 50 µm radius. The mode spacing, the linewidth of WGMs, and the shift of resonant wavelength due to the change in radius and refractive index, were analyzed by numerical simulations. Preliminary results of unspecific binding of biomolecules are presented. The calculated shift in WGMs can be used for biomolecules detection.
Y1  - 2012
U6  - http://dx.doi.org/10.1002/pssa.201100795
SN  - 1862-6319
N1  - Special Issue: "Fundamentals and Applications of Diamond"
VL  - 209
IS  - 9
SP  - 1804
EP  - 1810
PB  - Wiley-VCH
CY  - Weinheim
ER  -