@article{Berndt1979,
  author    = {Berndt, Heinz},
  title     = {Synthese der Sequenz 71—86 des Humanproinsulins, I : Synthese der Sequenz 71—86 als monomeres cyclisches Biscystinpeptidderivat und als Tetra-S-tritylderivat},
  series = {Hoppe-Seyler's Zeitschrift f{\"u}r physiologische Chemie},
  volume    = {360},
  journal   = {Hoppe-Seyler's Zeitschrift f{\"u}r physiologische Chemie},
  number    = {1},
  issn      = {1437-4315},
  doi       = {10.1515/bchm2.1979.360.1.747},
  pages     = {747 -- 760},
  year      = {1979},
  language  = {de}
}
@article{TeumerCapitainRossJonesetal.2018,
  author    = {Teumer, T. and Capitain, C. and Ross-Jones, J. and Tippk{\"o}tter, Nils and R{\"a}dle, M. and Methner, F.-J.},
  title     = {In-line Haze Monitoring Using a Spectrally Resolved Back Scattering Sensor},
  series = {BrewingScience},
  volume    = {71},
  journal   = {BrewingScience},
  number    = {5/6},
  publisher = {Fachverlag Hans Carl},
  address   = {N{\"u}rnberg},
  issn      = {1613-2041},
  pages     = {49 -- 55},
  year      = {2018},
  abstract  = {In the present work an optical sensor in combination with a spectrally resolved detection device for in-line particle-size-monitoring for quality control in beer production is presented. The principle relies on the size and wavelength dependent backscatter of growing particles in fluids. Measured interference structures of backscattered light are compared with calculated theoretical values, based on Mie-Theory, and fitted with a linear least square method to obtain particle size distributions. For this purpose, a broadband light source in combination with a process-CCD-spectrometer (charge ? coupled device spectrometer) and process adapted fiber optics are used. The goal is the development of an easy and flexible measurement device for in-line-monitoring of particle size. The presented device can be directly installed in product fill tubes or vessels, follows CIP- (cleaning in place) and removes the need of sample taking. A proof of concept and preliminary results, measuring protein precipitation, are presented.},
  language  = {en}
}
@techreport{TippkoetterWagner2019,
  author    = {Tippk{\"o}tter, Nils and Wagner, Sebastian},
  title     = {Biomimetischer Klebstoff aus ligninhaltigen Pflanzenresten (Teilvorhaben 1 und 2) : Schlussbericht zum Vorhaben : Laufzeit: 01.01.2016 bis 31.03.2019},
  publisher = {FH Aachen},
  address   = {J{\"u}lich},
  doi       = {10.2314/KXP:169732777X},
  pages     = {109 S.},
  year      = {2019},
  language  = {de}
}
@article{RoeschKratzHeringetal.2016,
  author    = {R{\"o}sch, C. and Kratz, F. and Hering, T. and Trautmann, S. and Umanskaya, N. and Tippk{\"o}tter, Nils and M{\"u}ller-Renno, C.M. and Ulber, Roland and Hannig, M. and Ziegler, C.},
  title     = {Albumin-lysozyme interactions: cooperative adsorption on titanium and enzymatic activity},
  series = {Colloids and Surfaces B: Biointerfaces},
  volume    = {149},
  journal   = {Colloids and Surfaces B: Biointerfaces},
  number    = {1},
  publisher = {Elsevier},
  address   = {Amsterdam},
  doi       = {10.1016/j.colsurfb.2016.09.048},
  pages     = {115 -- 121},
  year      = {2016},
  abstract  = {The interplay of albumin (BSA) and lysozyme (LYZ) adsorbed simultaneously on titanium was analyzed by gel electrophoresis and BCA assay. It was found that BSA and lysozyme adsorb cooperatively. Additionally, the isoelectric point of the respective protein influences the adsorption. Also, the enzymatic activity of lysozyme and amylase (AMY) in mixtures with BSA was considered with respect to a possible influence of protein-protein interaction on enzyme activity. Indeed, an increase of lysozyme activity in the presence of BSA could be observed. In contrast, BSA does not influence the activity of amylase.},
  language  = {en}
}
@article{MolinnusBaeckerSiegertetal.2015,
  author    = {Molinnus, Denise and B{\"a}cker, Matthias and Siegert, Petra and Willenberg, H. and Poghossian, Arshak and Keusgen, M. and Sch{\"o}ning, Michael Josef},
  title     = {Detection of Adrenaline Based on Substrate Recycling Amplification},
  series = {Procedia Engineering},
  volume    = {120},
  journal   = {Procedia Engineering},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {1877-7058},
  doi       = {10.1016/j.proeng.2015.08.708},
  pages     = {540 -- 543},
  year      = {2015},
  abstract  = {An amperometric enzyme biosensor has been applied for the detection of adrenaline. The adrenaline biosensor has been prepared by modification of an oxygen electrode with the enzyme laccase that operates at a broad pH range between pH 3.5 to pH 8. The enzyme molecules were immobilized via cross-linking with glutaraldehyde. The sensitivity of the developed adrenaline biosensor in different pH buffer solutions has been studied.},
  language  = {en}
}
@article{TippkoetterWollnyKampeisetal.2011,
  author    = {Tippk{\"o}tter, Nils and Wollny, S. and Kampeis, P. and Oster, J. and Schneider, H. and Ulber, Roland},
  title     = {Magnetseparation von Proteinen : Separation von Zielmolek{\"u}len durch hochselektive Aptamere},
  series = {GIT Labor-Fachzeitschrift},
  volume    = {55},
  journal   = {GIT Labor-Fachzeitschrift},
  number    = {10},
  publisher = {Wiley},
  address   = {Weinheim},
  pages     = {666},
  year      = {2011},
  abstract  = {Durch die Kombination von Oligonukleotid-Liganden (Aptameren) hoher Bindungsaffinit{\"a}ten mit hochselektiv abtrennbaren magnetisierbaren Mikropartikeln wird eine einstufige Separation von Zielmolek{\"u}len aus mikrobiologischen Produktionsans{\"a}tzen m{\"o}glich. Die Aptamere werden hierf{\"u}r reversibel auf den Partikeloberfl{\"a}chen gebunden und f{\"u}r die spezifische Isolierung von Bioprodukten eingesetzt. Die Abtrennung der beladenen Partikel erfolgt durch einen neuen Rotor-Stator-Separator mit Hochgradient-Magnetfeld.},
  language  = {de}
}
@incollection{WagemannTippkoetter2018,
  author    = {Wagemann, Kurt and Tippk{\"o}tter, Nils},
  title     = {Biorefineries: a short introduction},
  series = {Biorefineries},
  booktitle = {Biorefineries},
  publisher = {Springer},
  address   = {Cham},
  isbn      = {978-3-319-97117-9},
  doi       = {10.1007/10_2017_4},
  pages     = {1 -- 11},
  year      = {2018},
  abstract  = {The terms bioeconomy and biorefineries are used for a variety of processes and developments. This short introduction is intended to provide a delimitation and clarification of the terminology as well as a classification of current biorefinery concepts. The basic process diagrams of the most important biorefinery types are shown.},
  language  = {en}
}
@article{WulfhorstDuweMerseburgetal.2016,
  author    = {Wulfhorst, Helene and Duwe, Anna-Maria and Merseburg, Johannes and Tippk{\"o}tter, Nils},
  title     = {Compositional analysis of pretreated (beech) wood using differential scanning calorimetry and multivariate data analysis},
  series = {Tetrahedron},
  volume    = {72},
  journal   = {Tetrahedron},
  number    = {46},
  publisher = {Elsevier},
  address   = {Amsterdam},
  doi       = {10.1016/j.tet.2016.04.029},
  pages     = {7329 -- 7334},
  year      = {2016},
  abstract  = {The composition of plant biomass varies depending on the feedstock and pre-treatment conditions and influences its processing in biorefineries. In order to ensure optimal process conditions, the quantitative proportion of the main polymeric components of the pre-treated biomass has to be determined. Current standard procedures for biomass compositional analysis are complex, the measurements are afflicted with errors and therefore often not comparable. Hence, new powerful analytical methods are urgently required to characterize biomass. In this contribution, Differential Scanning Calorimetry (DSC) was applied in combination with multivariate data analysis (MVA) to detect the cellulose content of the plant biomass pretreated by Liquid Hot Water (LHW) and Organosolv processes under various conditions. Unlike conventional techniques, the developed analytic method enables the accurate quantification of monosaccharide content of the plant biomass without any previous sample preparation. It is easy to handle and avoids errors in sample preparation.},
  language  = {en}
}
@techreport{Tippkoetter2018,
  author    = {Tippk{\"o}tter, Nils},
  title     = {Lokale Vorbehandlung nachwachsender Rohstoffe f{\"u}r Bioraffinerien (BioSats) : Schlussbericht zum Vorhaben : Laufzeit: 01.03.2012 bis 30.04.2017},
  organization    = {Technische Universit{\"a}t Kaiserslautern},
  doi       = {10.2314/GBV:1024204243},
  pages     = {191 Seiten},
  year      = {2018},
  language  = {de}
}
@article{WackwitzBongaertsGoodmanetal.1999,
  author    = {Wackwitz, B. and Bongaerts, Johannes and Goodman, S. D. and Unden, Gottfried},
  title     = {Growth phase-dependent regulation of nuoA-N expression in Escherichia coli K-12 by the Fis protein: upstream binding sites and bioenergetic significance},
  series = {Molecular and general genetics : MGG},
  volume    = {Vol. 262},
  journal   = {Molecular and general genetics : MGG},
  number    = {Iss. 4 - 5},
  issn      = {1617-4623 (E-Journal); 1617-4615 (Print)},
  pages     = {876 -- 883},
  year      = {1999},
  language  = {en}
}
@article{TippkoetterRoikaewUlber2008,
  author    = {Tippk{\"o}tter, Nils and Roikaew, W. and Ulber, Roland},
  title     = {Nitrate removal from whey concentrate with biotechnological regeneration of the waste water},
  series = {European dairy magazine : EDM},
  journal   = {European dairy magazine : EDM},
  number    = {1},
  isbn      = {0936-6318},
  pages     = {30 -- 32},
  year      = {2008},
  language  = {en}
}
@article{UndenBeckerBongaertsetal.1995,
  author    = {Unden, G. and Becker, S. and Bongaerts, Johannes and Holighaus, G. and Schirawski, J. and Six, S.},
  title     = {O2-sensing and O2-dependent gene regulation in facultatively anaerobic bacteria},
  series = {Archives of microbiology},
  volume    = {Vol. 164},
  journal   = {Archives of microbiology},
  number    = {Iss. 2},
  issn      = {1432-072X (E-Journal); 0003-9276 (Print); 0302-8933 (Print)},
  pages     = {81 -- 90},
  year      = {1995},
  language  = {en}
}
@inproceedings{TippkoetterStueckmannWinkelmannetal.2007,
  author    = {Tippk{\"o}tter, Nils and St{\"u}ckmann, H. and Winkelmann, G. and Noack, U. and Beutel, S. and Scheper, T. and Ulber, Roland},
  title     = {Optimisation of antibody-labelling of gold colloids for their application in an immunchromatographic assay for microcystin-LR},
  series = {European BioPerspectives : celebrating the 25th DECHEMA annual convention of biotechnologists ; 30 May - 1 June 2007, Cologne, Germany ; book of abstracts ; abstracts, poster programme},
  booktitle = {European BioPerspectives : celebrating the 25th DECHEMA annual convention of biotechnologists ; 30 May - 1 June 2007, Cologne, Germany ; book of abstracts ; abstracts, poster programme},
  publisher = {Dechema},
  address   = {Frankfurt am Main},
  pages     = {126},
  year      = {2007},
  language  = {en}
}
@misc{AlKaidyTippkoetterUlber2016,
  author    = {Al-Kaidy, Huschyar and Tippk{\"o}tter, Nils and Ulber, Roland},
  title     = {Vorrichtung und Verfahren zur Bestimmung des Kontaktwinkels eines Fl{\"u}ssigk{\"o}rpers mit einer Festk{\"o}rperoberfl{\"a}che},
  year      = {2016},
  abstract  = {Die vorliegende Erfindung betrifft eine Vorrichtung und ein Verfahren zur Bestimmung des Kontaktwinkels eines fl{\"u}ssigen oder mit Fl{\"u}ssigkeit gef{\"u}llten K{\"o}rpers. Dieser besteht aus einem Tr{\"a}ger (1) und einer damit verbundenen, in einem Winkelbereich von mehr als 0 ° bis maximal 90 ° neigbaren Ebene (8) mit einer darin ausgebildeten Abrollbahn (9) f{\"u}r den fl{\"u}ssigen oder mit Fl{\"u}ssigkeit gef{\"u}llten K{\"o}rper. An der Ebene (8) sind mehrere Sensoren (11,12) zur Erfassung der Rolldauer des K{\"o}rpers entlang der Rollstrecke angeordnet. Erfindungsgem{\"a}ß ist vorgesehen, dass die Einstellung des Neigungswinkels der Ebene (8) {\"u}ber ein Winkelmessger{\"a}t (10) erfolgt, wodurch ein Abrollwinkel erfassbar ist, bei dem der K{\"o}rper in Bewegung ger{\"a}t. Aus der Rolldauer, der Rollstrecke und dem Abrollwinkel wird der Kontaktwinkel des K{\"o}rpers ermittelt.},
  language  = {de}
}
@article{TippkoetterDeterdingUlber2008,
  author    = {Tippk{\"o}tter, Nils and Deterding, A. and Ulber, Roland},
  title     = {Determination of acetic acid in fermentation broth by gas-diffusion technique},
  series = {Engineering in Life Sciences},
  volume    = {8},
  journal   = {Engineering in Life Sciences},
  number    = {1, Special Issue: Technical Systems for the Use in Life Sciences},
  doi       = {10.1002/elsc.200820227},
  pages     = {62 -- 67},
  year      = {2008},
  abstract  = {Due to the interfering effects of acetic acid in many fermentation processes, a gas-diffusion technique was developed for the online determination of acetic acid. The measurements were accomplished with a flow diffusion analysis (FDA) unit from the TRACE Analytics GmbH, Braunschweig, Germany. The diffusion analysis is based on the UV-absorbance of acetic acid at 205 nm. The measurement was achieved by the separation of an acceptor and a carrier stream (acidified fermentation broth) using a gas permeable polytetrafluoroethylene (PTFE) membrane, whereby broth constituents that would otherwise disturb the UV-measurement of acetic acid, are held back efficiently. Merely, the fermentation by-products, e.g. formic acid, is capable of diffusing through the membrane. While formic acid can disturb the measurement, carbon dioxide does not absorb at 205 nm. The method operates with time-dependent sample enrichment. During the analysis, a small volume of the acceptor stream is stopped for a defined time interval in the acceptor chamber. During this period, the gaseous acetic acid diffuses through the membrane and is enriched in the acceptor chamber. Subsequently after the enrichment, the acceptor stream flows through a UV-detector. The intensity of the signal is proportional to the acetic acid concentration. Online measurements in bioreactors via a sterile filtration probe have been accomplished. A linear calibration in the range of 0.5-5.0 g/L acetic acid with a relative standard deviation of <5 \% was obtained. A sampling rate of 8 samples per hour was possible. The system was applied for the determination of acetic acid in E. coli fermentation broth. The instrument is easy to clean, very user-friendly and does not require any toxic or expensive reagents.},
  language  = {en}
}
@article{BaeckerRakowskiPoghossianetal.2013,
  author    = {B{\"a}cker, Matthias and Rakowski, D. and Poghossian, Arshak and Biselli, Manfred and Wagner, Patrick and Sch{\"o}ning, Michael Josef},
  title     = {Chip-based amperometric enzyme sensor system for monitoring of bioprocesses by flow-injection analysis},
  series = {Journal of Biotechnology},
  volume    = {163},
  journal   = {Journal of Biotechnology},
  number    = {4},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {0168-1656},
  doi       = {10.1016/j.jbiotec.2012.03.014},
  pages     = {371 -- 376},
  year      = {2013},
  abstract  = {A microfluidic chip integrating amperometric enzyme sensors for the detection of glucose, glutamate and glutamine in cell-culture fermentation processes has been developed. The enzymes glucose oxidase, glutamate oxidase and glutaminase were immobilized by means of cross-linking with glutaraldehyde on platinum thin-film electrodes integrated within a microfluidic channel. The biosensor chip was coupled to a flow-injection analysis system for electrochemical characterization of the sensors. The sensors have been characterized in terms of sensitivity, linear working range and detection limit. The sensitivity evaluated from the respective peak areas was 1.47, 3.68 and 0.28 μAs/mM for the glucose, glutamate and glutamine sensor, respectively. The calibration curves were linear up to a concentration of 20 mM glucose and glutamine and up to 10 mM for glutamate. The lower detection limit amounted to be 0.05 mM for the glucose and glutamate sensor, respectively, and 0.1 mM for the glutamine sensor. Experiments in cell-culture medium have demonstrated a good correlation between the glutamate, glutamine and glucose concentrations measured with the chip-based biosensors in a differential-mode and the commercially available instrumentation. The obtained results demonstrate the feasibility of the realized microfluidic biosensor chip for monitoring of bioprocesses.},
  language  = {en}
}
@article{TranBongaertsVladetal.1997,
  author    = {Tran, Quang Hon and Bongaerts, Johannes and Vlad, Dorina and Unden, Gottfried},
  title     = {Requirement for the proton-pumping NADH dehydrogenase I of Escherichia coli in respiration of NADH to fumarate and its bioenergetic implications},
  series = {European journal of biochemistry},
  volume    = {Vol. 244},
  journal   = {European journal of biochemistry},
  number    = {Iss. 1},
  issn      = {0014-2956},
  pages     = {155 -- 160},
  year      = {1997},
  language  = {en}
}
@article{WiegandVoigtAlbrechtetal.2013,
  author    = {Wiegand, Sandra and Voigt, Birgit and Albrecht, Dirk and Bongaerts, Johannes and Evers, Stefan and Hecker, Michael and Daniel, Rolf and Liesegang, Heiko},
  title     = {Fermentation stage-dependent adaptations of Bacillus licheniformis during enzyme production},
  series = {Microbial Cell Factories},
  volume    = {12},
  journal   = {Microbial Cell Factories},
  publisher = {Biomed Central},
  address   = {London},
  issn      = {1475-2859},
  doi       = {10.1186/1475-2859-12-120},
  pages     = {120},
  year      = {2013},
  language  = {en}
}
@inproceedings{TippkoetterRoikaewUlber2008,
  author    = {Tippk{\"o}tter, Nils and Roikaew, W. and Ulber, Roland},
  title     = {An automated pilot plant for the bioengineering processing of concentrated whey},
  series = {European BioPerspectives : in cooperation with BIOTECHNICA 2008 : 7 - 9 October 2008 Hannover, Germany ; book of abstracts ; abstracts, poster programme},
  booktitle = {European BioPerspectives : in cooperation with BIOTECHNICA 2008 : 7 - 9 October 2008 Hannover, Germany ; book of abstracts ; abstracts, poster programme},
  publisher = {Dechema},
  address   = {Frankfurt am Main},
  pages     = {98},
  year      = {2008},
  language  = {en}
}
@article{ZientzBongaertsUnden1998,
  author    = {Zientz, Evelyn and Bongaerts, Johannes and Unden, Gottfried},
  title     = {Fumarate regulation of gene expression in Escherichia coli by the DcuSR (dcuSR genes) two-component regulatory system},
  series = {Journal of bacteriology},
  volume    = {Vol. 180},
  journal   = {Journal of bacteriology},
  number    = {No. 20},
  issn      = {1098-5530 (E-Journal); 0021-9193 (Print)},
  pages     = {5421 -- 5425},
  year      = {1998},
  language  = {en}
}
@inproceedings{DeterdingTippkoetterUlber2006,
  author    = {Deterding, A. and Tippk{\"o}tter, Nils and Ulber, Roland},
  title     = {Online-Essigs{\"a}ureanalytik in Fermentationsbr{\"u}hen mittels Fließdiffusionstechnik (FDT)},
  series = {Technische Systeme f{\"u}r Biotechnologie und Umwelt : 13. Heiligenst{\"a}dter Kolloquium, Heilbad Heiligenstadt, 25.09. - 27.09.2006},
  booktitle = {Technische Systeme f{\"u}r Biotechnologie und Umwelt : 13. Heiligenst{\"a}dter Kolloquium, Heilbad Heiligenstadt, 25.09. - 27.09.2006},
  editor    = {Beckmann, Dieter},
  address   = {Heiligenstadt},
  organization    = {Institut f{\"u}r Bioprozeß- und Analysenmeßtechnik},
  isbn      = {978-3-00-018621-9},
  pages     = {273 -- 280},
  year      = {2006},
  language  = {de}
}
@incollection{UlberMufflerTippkoetteretal.2011,
  author    = {Ulber, Roland and Muffler, Kai and Tippk{\"o}tter, Nils and Hirth, Thomas and Sell, Dieter},
  title     = {Introduction to Renewable Resources in the Chemical Industry},
  series = {Renewable raw materials : new feedstocks for the chemical industry},
  booktitle = {Renewable raw materials : new feedstocks for the chemical industry},
  editor    = {Ulber, Roland and Sell, Dieter and Hirth, Thomas},
  edition   = {1. Auflage},
  publisher = {Wiley-VCH-Verlag},
  address   = {Weinheim},
  isbn      = {978-3-527-32548-1},
  pages     = {1 -- 6},
  year      = {2011},
  language  = {de}
}
@article{WiesenTippkoetterMuffleretal.2014,
  author    = {Wiesen, Sebastian and Tippk{\"o}tter, Nils and Muffler, Kai and Suck, Kirstin and Sohling, Ulrich and Ruf, Nils and Ulber, Roland},
  title     = {Adsorptive Vorbehandlung von Rohglycerin f{\"u}r die 1,3-Propandiol Fermentation mit Clostridium diolis},
  series = {Chemie Ingenieur Technik},
  volume    = {86},
  journal   = {Chemie Ingenieur Technik},
  number    = {1-2},
  publisher = {Wiley-VCH},
  address   = {Weinheim},
  doi       = {10.1002/cite.201300080},
  pages     = {129 -- 135},
  year      = {2014},
  abstract  = {Bei der Gewinnung von Fetts{\"a}uren aus Pflanzen{\"o}len, z. B. zur Herstellung von Biopolymeren, oder bei der Biodiesel- und Seifenproduktion, f{\"a}llt Glycerin als Nebenprodukt an. Bei der Biokonversion dieses Rohstoffes zu 1,3-Propandiol wird der Produktionsorganismus Clostridium diolis durch Verunreinigungen im Rohglycerin gehemmt. Als inhibierende Substanzen konnten freie Fetts{\"a}uren identifiziert werden. Mithilfe eines adsorptiven Aufarbeitungsverfahrens ist es gelungen, die Fetts{\"a}uren zu entfernen und die Konversionseffizienz zu 1,3-Propandiol zu erh{\"o}hen.},
  language  = {de}
}
@article{RothTippkoetter2016,
  author    = {Roth, Jasmine and Tippk{\"o}tter, Nils},
  title     = {Evaluation of lignocellulosic material for butanol production using enzymatic hydrolysate medium},
  series = {Cellulose Chemistry and Technology},
  volume    = {50},
  journal   = {Cellulose Chemistry and Technology},
  number    = {3-4},
  publisher = {Editura Academiei Romane},
  address   = {Bukarest},
  pages     = {405 -- 410},
  year      = {2016},
  abstract  = {Butanol is a promising gasoline additive and platform chemical that can be readily produced via acetone-butanolethanol (ABE) fermentation from pretreated lignocellulosic materials. This article examines lignocellulosic material from beech wood for ABE fermentation, using Clostridium acetobutylicum. First, the utilization of both C₅₋ (xylose) and C₆₋ (glucose) sugars as sole carbon source was investigated in static cultivation, using serum bottles and synthetic medium. The utilization of pentose sugar resulted in a solvent yield of 0.231 g·g_sugar⁻¹, compared to 0.262 g·g_sugar⁻¹ using hexose. Then, the Organosolv pretreated crude cellulose fibers (CF) were enzymatically decomposed, and the resulting hydrolysate medium was analyzed for inhibiting compounds (furans, organic acids, phenolics) and treated with ionexchangers for detoxification. Batch fermentation in a bioreactor using CF hydrolysate medium resulted in a total solvent yield of 0.20 gABE·g_sugar⁻¹.},
  language  = {en}
}
@article{BechtSchollmayerMonakhovaetal.2021,
  author    = {Becht, Alexander and Schollmayer, Curd and Monakhova, Yulia and Holzgrabe, Ulrike},
  title     = {Tracing the origin of paracetamol tablets by near-infrared, mid-infrared, and nuclear magnetic resonance spectroscopy using principal component analysis and linear discriminant analysis},
  series = {Analytical and Bioanalytical Chemistry},
  volume    = {413},
  journal   = {Analytical and Bioanalytical Chemistry},
  publisher = {Springer Nature},
  issn      = {1618-2650},
  doi       = {10.1007/s00216-021-03249-z},
  pages     = {3107 -- 3118},
  year      = {2021},
  abstract  = {Most drugs are no longer produced in their own countries by the pharmaceutical companies, but by contract manufacturers or at manufacturing sites in countries that can produce more cheaply. This not only makes it difficult to trace them back but also leaves room for criminal organizations to fake them unnoticed. For these reasons, it is becoming increasingly difficult to determine the exact origin of drugs. The goal of this work was to investigate how exactly this is possible by using different spectroscopic methods like nuclear magnetic resonance and near- and mid-infrared spectroscopy in combination with multivariate data analysis. As an example, 56 out of 64 different paracetamol preparations, collected from 19 countries around the world, were chosen to investigate whether it is possible to determine the pharmaceutical company, manufacturing site, or country of origin. By means of suitable pre-processing of the spectra and the different information contained in each method, principal component analysis was able to evaluate manufacturing relationships between individual companies and to differentiate between production sites or formulations. Linear discriminant analysis showed different results depending on the spectral method and purpose. For all spectroscopic methods, it was found that the classification of the preparations to their manufacturer achieves better results than the classification to their pharmaceutical company. The best results were obtained with nuclear magnetic resonance and near-infrared data, with 94.6\%/99.6\% and 98.7/100\% of the spectra of the preparations correctly assigned to their pharmaceutical company or manufacturer.},
  language  = {en}
}
@article{LindnerBurgerRutledgeetal.2022,
  author    = {Lindner, Simon and Burger, Ren{\´e} and Rutledge, Douglas N. and Do, Xuan Tung and Rumpf, Jessica and Diehl, Bernd W. K. and Schulze, Margit and Monakhova, Yulia},
  title     = {Is the calibration transfer of multivariate calibration models between high- and low-field NMR instruments possible? A case study of lignin molecular weight},
  series = {Analytical chemistry},
  volume    = {94},
  journal   = {Analytical chemistry},
  number    = {9},
  publisher = {ACS Publications},
  address   = {Washington, DC},
  isbn      = {1520-6882},
  doi       = {10.1021/acs.analchem.1c05125},
  pages     = {3997 -- 4004},
  year      = {2022},
  abstract  = {Although several successful applications of benchtop nuclear magnetic resonance (NMR) spectroscopy in quantitative mixture analysis exist, the possibility of calibration transfer remains mostly unexplored, especially between high- and low-field NMR. This study investigates for the first time the calibration transfer of partial least squares regressions [weight average molecular weight (Mw) of lignin] between high-field (600 MHz) NMR and benchtop NMR devices (43 and 60 MHz). For the transfer, piecewise direct standardization, calibration transfer based on canonical correlation analysis, and transfer via the extreme learning machine auto-encoder method are employed. Despite the immense resolution difference between high-field and low-field NMR instruments, the results demonstrate that the calibration transfer from high- to low-field is feasible in the case of a physical property, namely, the molecular weight, achieving validation errors close to the original calibration (down to only 1.2 times higher root mean square errors). These results introduce new perspectives for applications of benchtop NMR, in which existing calibrations from expensive high-field instruments can be transferred to cheaper benchtop instruments to economize.},
  language  = {en}
}
@misc{EngelTippkoetter2016,
  author    = {Engel, M. and Tippk{\"o}tter, Nils},
  title     = {Einfluss eines Phenazin-Mediators und elektrischen Potenzials auf die Aceton-Butanol-Ethanol-Fermentation},
  series = {Chemie Ingenieur Technik},
  volume    = {88},
  journal   = {Chemie Ingenieur Technik},
  number    = {9},
  publisher = {Wiley-VCH},
  address   = {Weinheim},
  issn      = {0009-286X},
  doi       = {10.1002/cite.201650105},
  pages     = {1254},
  year      = {2016},
  abstract  = {In den letzten Jahren haben nachhaltige, biotechnologische Prozesse zunehmend an Bedeutung gewonnen. Die Aceton-Butanol-Ethanol-Fermentation (ABE-Fermentation) mit dem anaeroben Bakterium Clostridium acetobutylicum zur Gewinnung von Biobutanol k{\"o}nnte in diesem Zusammenhang eine M{\"o}glichkeit der nachhaltigen Kraftstoffproduktion darstellen. In dieser Arbeit wird der Einfluss zus{\"a}tzlich verf{\"u}gbarer Elektronen durch den Einsatz des Phenazin-Farbstoffs Neutralrot als Redoxmediator sowie das Anlegen eines elektrischen Potenzials w{\"a}hrend der ABE-Fermentation untersucht. Es wird gezeigt, dass das Neutralrot keinen Einfluss auf die Leerlaufspannung von ca. 500 mV vs. Ag/AgCl w{\"a}hrend der Fermentation hat. Der Mediator bewirkt allerdings eine fr{\"u}here Butanolbildung sowie h{\"o}here Butanolkonzentrationen. Wird zudem die Mediatorkonzentration von 125 mM auf 250 mM angehoben, wird dabei auch die maximale Butanolkonzentration um 36 \% ± 1,8 \% innerhalb von28 Stunden gesteigert.},
  language  = {de}
}
@misc{SiekerTippkoetterUlber2010,
  author    = {Sieker, T. and Tippk{\"o}tter, Nils and Ulber, Roland},
  title     = {Simultane Vorbehandlung, Hydrolyse und Fermentation bei der Nutzung von gr{\"u}ner Biomasse zur Produktion von Bioethanol},
  series = {Chemie Ingenieur Technik},
  volume    = {82},
  journal   = {Chemie Ingenieur Technik},
  number    = {9},
  publisher = {Wiley-VCH},
  address   = {Weinheim},
  issn      = {0009-286X},
  doi       = {10.1002/cite.201050319},
  pages     = {1601},
  year      = {2010},
  abstract  = {Gr{\"a}ser sind in der Lage, einen großen Teil der f{\"u}r eine biobasierte Wirtschaft ben{\"o}tigten Biomasse zur Verf{\"u}gung zu stellen. Wie bei anderen lignocellulosehaltigen nachwachsenden Rohstoffen erfordert die Verwertung der im Gras enthaltenen Polysaccharide einen mehrstufigen Prozess aus Vorbehandlung, Hydrolyse und Fermentation. In Gr{\"a}sern ist die Hemicellulose mitP henolcarbons{\"a}uren wie Ferula- und p-Coumars{\"a}ure verestert, die die enzymatische Hydrolyse der Cellulose und Hemicellulose ebenso effektiv behindern wie Lignin. Anders als bei holzigen Rohstoffen erm{\"o}glicht dieser Aufbau aber eine enzymatische Vorbehandlung, mit der die Phenolcarbons{\"a}uren abgespalten werden k{\"o}nnen. Da die bei der Vorbehandlung eingesetzten Enzyme in ihrer nat{\"u}rlichen Funktion synergistisch mit cellulytischen Enzymen zusammenarbeiten, besitzen sie {\"a}hnliche Optima wie die f{\"u}r die Hydrolyse der Polysaccharide eingesetzten Cellulasen und Hemicellulasen. Diese Eigenschaft erm{\"o}glicht die Integration von Vorbehandlung und Hydrolyse in einem einzigen Verfahrensschritt. Durch die Einf{\"u}hrung der enzymatischen Vorbehandlung konnte das in der Literatur bekannte SSF-Verfahren f{\"u}r die Herstellung von Ethanol aus Gr{\"a}sern um die Vorbehandlungsstufe erweitert werden. Das so realisierte simultaneous pretreatment, saccharification and fermentation (SPSF)-Verfahren stellt eine vollst{\"a}ndige Integration der drei f{\"u}r die Nutzung von Lignocellulose n{\"o}tigen Verfahrensschritte in der gr{\"u}nen Bioraffinerie dar.},
  language  = {de}
}
@article{AlKaidyDuweHusteretal.2014,
  author    = {Al-Kaidy, Huschyar and Duwe, Anna and Huster, Manuel and Muffler, Kai and Schlegel, Christin and Sieker, Tim and Stadtm{\"u}ller, Ralf and Tippk{\"o}tter, Nils and Ulber, Roland},
  title     = {Biotechnologie und Bioverfahrenstechnik - Vom ersten Ullmanns Artikel bis hin zu aktuellen Forschungsthemen},
  series = {Chemie Ingenieur Technik},
  volume    = {86},
  journal   = {Chemie Ingenieur Technik},
  number    = {12},
  publisher = {Wiley-VCH},
  address   = {Weinheim},
  issn      = {0009-286X},
  doi       = {10.1002/cite.201400083},
  pages     = {2215 -- 2225},
  year      = {2014},
  abstract  = {Biotechnologie und die mit ihr verbundenen technischen Prozesse pr{\"a}gen seit Jahrtausenden die Entwicklung der Menschheit. Ausgehend von empirischen Verfahren, insbesondere zur Herstellung von Lebensmitteln und t{\"a}glichen Gebrauchsg{\"u}tern, haben sich diese Disziplinen zu einem der innovativsten Zukunftsfelder entwickelt. Durch das immer detailliertere Verst{\"a}ndnis zellul{\"a}rer Vorg{\"a}nge k{\"o}nnen mittlerweile Produktionsst{\"a}mme gezielt optimiert werden. Im Zusammenspiel mit moderner Prozesstechnik k{\"o}nnen so eine Vielzahl von Bulk- und Feinchemikalien sowie Pharmazeutika effizient hergestellt werden. In diesem Artikel werden exemplarisch einige der aktuellen Trends vorgestellt.},
  language  = {de}
}
@article{UndenBeckerBongaertsetal.1994,
  author    = {Unden, G. and Becker, S. and Bongaerts, Johannes and Schirawski, J. and Six, S.},
  title     = {Oxygen regulated gene expression in facultatively anaerobic bacteria},
  series = {Antonie van Leeuwenhoek},
  volume    = {Vol. 66},
  journal   = {Antonie van Leeuwenhoek},
  number    = {Iss. 1-3},
  issn      = {0003-6072 (Print) ; 1572-9699 (online)},
  pages     = {3 -- 22},
  year      = {1994},
  language  = {en}
}
@article{PasteurTippkoetterKampeisetal.2014,
  author    = {Pasteur, Aline and Tippk{\"o}tter, Nils and Kampeis, Percy and Ulber, Roland},
  title     = {Optimization of high gradient magnetic separation filter units for the purification of fermentation products},
  series = {IEEE TRANSACTIONS ON MAGNETICS},
  volume    = {50},
  journal   = {IEEE TRANSACTIONS ON MAGNETICS},
  number    = {10},
  publisher = {IEEE},
  address   = {New York, NY},
  issn      = {0018-9464},
  doi       = {10.1109/TMAG.2014.2325535},
  pages     = {Artikel 5000607},
  year      = {2014},
  abstract  = {High gradient magnetic separation (HGMS) has been established since the early 1970s. A more recent application of these systems is the use in bioprocesses. To integrate the HGMS in a fermentation process, it is necessary to optimize the separation matrix with regard to the magnetic separation characteristics and permeability of the non-magnetizable components of the fermentation broth. As part of the work presented here, a combined fluidic and magnetic force finite element model simulation was created using the software COMSOL Multiphysics and compared with separation experiments. Finally, as optimal lattice orientation of the separation matrix, a transversal rhombohedral arrangement was defined. The high suitability of the new filter matrix has been verified by separation experiments.},
  language  = {en}
}
@article{UlberTippkoetter2009,
  author    = {Ulber, Roland and Tippk{\"o}tter, Nils},
  title     = {Nitratfreie Molke},
  series = {Rundschau f{\"u}r Fleischhygiene und Lebensmittel{\"u}berwachung},
  journal   = {Rundschau f{\"u}r Fleischhygiene und Lebensmittel{\"u}berwachung},
  number    = {4},
  pages     = {150 -- 152},
  year      = {2009},
  language  = {de}
}
@misc{AlKaidyTippkoetterUlber2013,
  author    = {Al-Kaidy, Huschyar and Tippk{\"o}tter, Nils and Ulber, Roland},
  title     = {A system and a method for the implementation of chemical, biological or physical reactions [Europ{\"a}ische Patentanmeldung]},
  publisher = {Europ{\"a}isches Patentamt},
  address   = {Den Hague},
  pages     = {16 Seiten},
  year      = {2013},
  abstract  = {The invention relates to a system for the implementation of chemical, biological or physical reactions, consisting of - one or more magnetic micro-reactors, each comprising a shell made of hydrophobic magnetic nanoparticles encapsulating an aqueous core, - a plane platform comprising a surface to receive the micro-reactors, - a source that generates a magnetic field above or underneath the platform for manipulating the one or more hydrophobic magnetic micro-reactors, or for moving them along the surface of the platform from one position to another position, characterized in that the aqueous core of the one or more magnetic micro-reactors contains a reaction solution or buffer, and wherein the magnetic field generated by the source correlates to a defined position on the surface of the platform.},
  language  = {en}
}
@article{WiesenTippkoetterMuffleretal.2015,
  author    = {Wiesen, Sebastian and Tippk{\"o}tter, Nils and Muffler, Kai and Suck, Kirstin and Sohling, Ulrich and Ruf, Friedrich and Ulber, Roland},
  title     = {Adsorption of fatty acids to layered double hydroxides in aqueous systems},
  series = {Adsorption},
  volume    = {21},
  journal   = {Adsorption},
  number    = {6-7},
  publisher = {Springer},
  address   = {Berlin},
  pages     = {459 -- 466},
  year      = {2015},
  abstract  = {Due to their anion exchange characteristics, layered double hydroxides (LDHs) are suitable for the detoxification of aqueous, fatty acid containing fermentation substrates. The aim of this study is to examine the adsorption mechanism, using crude glycerol from plant oil esterification as a model system. Changes in the intercalation structure in relation to the amount of fatty acids adsorbed are monitored by X-ray diffraction and infra-red spectroscopy. Additionally, calcination of LDH is investigated in order to increase the binding capacity for fatty acids. Our data propose that, at ambient temperature, fatty acids can be bound to the hydrotalcite by adsorption or in addition by intercalation, depending on fatty acid concentration. The adsorption of fatty acids from crude glycerol shows a BET-like behavior. Above a fatty acid concentration of 3.5 g L-1, intercalation of fatty acids can be shown by the appearance of an increased interlayer spacing. This observation suggests a two phase adsorption process. Calcination of LDHs allows increasing the binding capacity for fatty acids by more than six times, mainly by reduction of structural CO32-.},
  language  = {en}
}
@article{MuesgenanntKoersPrevostPaulssenetal.2023,
  author    = {Mues genannt Koers, Lucas and Prevost, David and Paulßen, Elisabeth and Hoehr, Cornelia},
  title     = {Density reduction effects on the production of [11C]CO2 in Nb-body targets on a medical cyclotron},
  volume    = {199},
  number    = {Art. 110911},
  publisher = {Elsevier},
  address   = {Amsterdam},
  doi       = {10.1016/j.apradiso.2023.110911},
  year      = {2023},
  abstract  = {Medical isotope production of 11C is commonly performed in gaseous targets. The power deposition of the proton beam during the irradiation decreases the target density due to thermodynamic mixing and can cause an increase of penetration depth and divergence of the proton beam. In order to investigate the difference how the target-body length influences the operation conditions and the production yield, a 12 cm and a 22 cm Nb-target body containing N2/O2 gas were irradiated using a 13 MeV proton cyclotron. It was found that the density reduction has a large influence on the pressure rise during irradiation and the achievable radioactive yield. The saturation activity of [11C]CO2 for the long target (0.083 Ci/μA) is about 10\% higher than in the short target geometry (0.075 Ci/μA).},
  language  = {en}
}
@article{BergsMonakhovaDiehletal.2021,
  author    = {Bergs, Michel and Monakhova, Yulia and Diehl, Bernd W. and Konow, Christopher and V{\"o}lkering, Georg and Pude, Ralf and Schulze, Margit},
  title     = {Lignins isolated via catalyst-free organosolv pulping from Miscanthus x giganteus, M. sinensis, M. robustus and M. nagara: a comparative study},
  series = {Molecules},
  volume    = {26},
  journal   = {Molecules},
  number    = {4},
  publisher = {MDPI},
  address   = {Basel},
  issn      = {1420-3049},
  doi       = {10.3390/molecules26040842},
  year      = {2021},
  abstract  = {As a low-input crop, Miscanthus offers numerous advantages that, in addition to agricultural applications, permits its exploitation for energy, fuel, and material production. Depending on the Miscanthus genotype, season, and harvest time as well as plant component (leaf versus stem), correlations between structure and properties of the corresponding isolated lignins differ. Here, a comparative study is presented between lignins isolated from M. x giganteus, M. sinensis, M. robustus and M. nagara using a catalyst-free organosolv pulping process. The lignins from different plant constituents are also compared regarding their similarities and differences regarding monolignol ratio and important linkages. Results showed that the plant genotype has the weakest influence on monolignol content and interunit linkages. In contrast, structural differences are more significant among lignins of different harvest time and/or season. Analyses were performed using fast and simple methods such as nuclear magnetic resonance (NMR) spectroscopy. Data was assigned to four different linkages (A: β-O-4 linkage, B: phenylcoumaran, C: resinol, D: β-unsaturated ester). In conclusion, A content is particularly high in leaf-derived lignins at just under 70\% and significantly lower in stem and mixture lignins at around 60\% and almost 65\%. The second most common linkage pattern is D in all isolated lignins, the proportion of which is also strongly dependent on the crop portion. Both stem and mixture lignins, have a relatively high share of approximately 20\% or more (maximum is M. sinensis Sin2 with over 30\%). In the leaf-derived lignins, the proportions are significantly lower on average. Stem samples should be chosen if the highest possible lignin content is desired, specifically from the M. x giganteus genotype, which revealed lignin contents up to 27\%. Due to the better frost resistance and higher stem stability, M. nagara offers some advantages compared to M. x giganteus. Miscanthus crops are shown to be very attractive lignocellulose feedstock (LCF) for second generation biorefineries and lignin generation in Europe.},
  language  = {en}
}
@article{BurgerRumpfDoetal.2021,
  author    = {Burger, Ren{\´e} and Rumpf, Jessica and Do, Xuan Tung and Monakhova, Yulia and Diehl, Bernd W. K. and Rehahn, Matthias and Schulze, Margit},
  title     = {Is NMR combined with multivariate regression applicable for the molecular weight determination of randomly cross-linked polymers such as lignin?},
  series = {ACS Omega},
  volume    = {6},
  journal   = {ACS Omega},
  number    = {44},
  publisher = {ACS Publications},
  address   = {Washington, DC},
  issn      = {2470-1343},
  doi       = {10.1021/acsomega.1c03574},
  pages     = {29516 -- 29524},
  year      = {2021},
  abstract  = {The molecular weight properties of lignins are one of the key elements that need to be analyzed for a successful industrial application of these promising biopolymers. In this study, the use of 1H NMR as well as diffusion-ordered spectroscopy (DOSY NMR), combined with multivariate regression methods, was investigated for the determination of the molecular weight (Mw and Mn) and the polydispersity of organosolv lignins (n = 53, Miscanthus x giganteus, Paulownia tomentosa, and Silphium perfoliatum). The suitability of the models was demonstrated by cross validation (CV) as well as by an independent validation set of samples from different biomass origins (beech wood and wheat straw). CV errors of ca. 7-9 and 14-16\% were achieved for all parameters with the models from the 1H NMR spectra and the DOSY NMR data, respectively. The prediction errors for the validation samples were in a similar range for the partial least squares model from the 1H NMR data and for a multiple linear regression using the DOSY NMR data. The results indicate the usefulness of NMR measurements combined with multivariate regression methods as a potential alternative to more time-consuming methods such as gel permeation chromatography.},
  language  = {en}
}
@article{MonakhovaDiehl2022,
  author    = {Monakhova, Yulia and Diehl, Bernd W.K.},
  title     = {Nuclear magnetic resonance spectroscopy as an elegant tool for a complete quality control of crude heparin material},
  series = {Journal of Pharmaceutical and Biomedical Analysis},
  volume    = {219},
  journal   = {Journal of Pharmaceutical and Biomedical Analysis},
  number    = {Article number: 114915},
  publisher = {Elsevier},
  address   = {New York, NY},
  issn      = {0731-7085},
  doi       = {10.1016/j.jpba.2022.114915},
  year      = {2022},
  abstract  = {Nuclear magnetic resonance (NMR) spectrometric methods for the quantitative analysis of pure heparin in crude heparin is proposed. For quantification, a two-step routine was developed using a USP heparin reference sample for calibration and benzoic acid as an internal standard. The method was successfully validated for its accuracy, reproducibility, and precision. The methodology was used to analyze 20 authentic porcine heparinoid samples having heparin content between 4.25 w/w \% and 64.4 w/w \%. The characterization of crude heparin products was further extended to a simultaneous analysis of these common ions: sodium, calcium, acetate and chloride. A significant, linear dependence was found between anticoagulant activity and assayed heparin content for thirteen heparinoids samples, for which reference data were available. A Diffused-ordered NMR experiment (DOSY) can be used for qualitative analysis of specific glycosaminoglycans (GAGs) in heparinoid matrices and, potentially, for quantitative prediction of molecular weight of GAGs. NMR spectrometry therefore represents a unique analytical method suitable for the simultaneous quantitative control of organic and inorganic composition of crude heparin samples (especially heparin content) as well as an estimation of other physical and quality parameters (molecular weight, animal origin and activity).},
  language  = {en}
}
@article{MonakhovaDiehl2021,
  author    = {Monakhova, Yulia and Diehl, Bernd W. K.},
  title     = {Simplification of NMR Workflows by Standardization Using 2H Integral of Deuterated Solvent as Applied to Aloe vera Preparations},
  series = {Applied Magnetic Resonance},
  volume    = {52},
  journal   = {Applied Magnetic Resonance},
  number    = {11},
  publisher = {Springer},
  address   = {Cham},
  issn      = {1613-7507},
  doi       = {10.1007/s00723-021-01393-4},
  pages     = {1591 -- 1600},
  year      = {2021},
  abstract  = {In this study, a recently proposed NMR standardization approach by 2H integral of deuterated solvent for quantitative multicomponent analysis of complex mixtures is presented. As a proof of principle, the existing NMR routine for the analysis of Aloe vera products was modified. Instead of using absolute integrals of targeted compounds and internal standard (nicotinamide) from 1H-NMR spectra, quantification was performed based on the ratio of a particular 1H-NMR compound integral and 2H-NMR signal of deuterated solvent D2O. Validation characteristics (linearity, repeatability, accuracy) were evaluated and the results showed that the method has the same precision as internal standardization in case of multicomponent screening. Moreover, a dehydration process by freeze drying is not necessary for the new routine. Now, our NMR profiling of A. vera products needs only limited sample preparation and data processing. The new standardization methodology provides an appealing alternative for multicomponent NMR screening. In general, this novel approach, using standardization by 2H integral, benefits from reduced sample preparation steps and uncertainties, and is recommended in different application areas (purity determination, forensics, pharmaceutical analysis, etc.).},
  language  = {en}
}
@article{BurgerLindnerRumpfetal.2022,
  author    = {Burger, Ren{\´e} and Lindner, Simon and Rumpf, Jessica and Do, Xuan Tung and Diehl, Bernd W.K. and Rehahn, Matthias and Monakhova, Yulia and Schulze, Margit},
  title     = {Benchtop versus high field NMR: Comparable performance found for the molecular weight determination of lignin},
  series = {Journal of Pharmaceutical and Biomedical Analysis},
  volume    = {212},
  journal   = {Journal of Pharmaceutical and Biomedical Analysis},
  number    = {Article number: 114649},
  publisher = {Elsevier},
  address   = {New York, NY},
  isbn      = {0731-7085},
  doi       = {10.1016/j.jpba.2022.114649},
  year      = {2022},
  abstract  = {Lignin is a promising renewable biopolymer being investigated worldwide as an environmentally benign substitute of fossil-based aromatic compounds, e.g. for the use as an excipient with antioxidant and antimicrobial properties in drug delivery or even as active compound. For its successful implementation into process streams, a quick, easy, and reliable method is needed for its molecular weight determination. Here we present a method using 1H spectra of benchtop as well as conventional NMR systems in combination with multivariate data analysis, to determine lignin's molecular weight (Mw and Mn) and polydispersity index (PDI). A set of 36 organosolv lignin samples (from Miscanthus x giganteus, Paulownia tomentosa and Silphium perfoliatum) was used for the calibration and cross validation, and 17 samples were used as external validation set. Validation errors between 5.6\% and 12.9\% were achieved for all parameters on all NMR devices (43, 60, 500 and 600 MHz). Surprisingly, no significant difference in the performance of the benchtop and high-field devices was found. This facilitates the application of this method for determining lignin's molecular weight in an industrial environment because of the low maintenance expenditure, small footprint, ruggedness, and low cost of permanent magnet benchtop NMR systems.},
  language  = {en}
}
@article{MonakhovaSobolevaFedotovaetal.2022,
  author    = {Monakhova, Yulia and Soboleva, Polina M. and Fedotova, Elena S. and Musina, Kristina T. and Burmistrova, Natalia A.},
  title     = {Quantum chemical calculations of IR spectra of heparin disaccharide subunits},
  series = {Computational and Theoretical Chemistry},
  volume    = {1217},
  journal   = {Computational and Theoretical Chemistry},
  number    = {Article number: 113891},
  publisher = {Elsevier},
  address   = {New York, NY},
  isbn      = {2210-271X},
  doi       = {10.1016/j.comptc.2022.113891},
  year      = {2022},
  abstract  = {Heparin is a natural polysaccharide, which plays essential role in many biological processes. Alterations in building blocks can modify biological roles of commercial heparin products, due to significant changes in the conformation of the polymer chain. The variability structure of heparin leads to difficulty in quality control using different analytical methods, including infrared (IR) spectroscopy. In this paper molecular modelling of heparin disaccharide subunits was performed using quantum chemistry. The structural and spectral parameters of these disaccharides have been calculated using RHF/6-311G. In addition, over-sulphated chondroitin sulphate disaccharide was studied as one of the most widespread contaminants of heparin. Calculated IR spectra were analyzed with respect to specific structure parameters. IR spectroscopic fingerprint was found to be sensitive to substitution pattern of disaccharide subunits. Vibrational assignments of calculated spectra were correlated with experimental IR spectral bands of native heparin. Chemometrics was used to perform multivariate analysis of simulated spectral data.},
  language  = {en}
}
@article{BurmistrovaSobolevaMonakhova2021,
  author    = {Burmistrova, Natalia A. and Soboleva, Polina M. and Monakhova, Yulia},
  title     = {Is infrared spectroscopy combined with multivariate analysis a promising tool for heparin authentication?},
  series = {Journal of Pharmaceutical and Biomedical Analysis},
  volume    = {194},
  journal   = {Journal of Pharmaceutical and Biomedical Analysis},
  number    = {Article number: 113811},
  publisher = {Elsevier},
  address   = {Amsterdam},
  isbn      = {0731-7085},
  doi       = {10.1016/j.jpba.2020.113811},
  year      = {2021},
  abstract  = {The investigation of the possibility to determine various characteristics of powder heparin (n = 115) was carried out with infrared spectroscopy. The evaluation of heparin samples included several parameters such as purity grade, distributing company, animal source as well as heparin species (i.e. Na-heparin, Ca-heparin, and heparinoids). Multivariate analysis using principal component analysis (PCA), soft independent modelling of class analogy (SIMCA), and partial least squares - discriminant analysis (PLS-DA) were applied for the modelling of spectral data. Different pre-processing methods were applied to IR spectral data; multiplicative scatter correction (MSC) was chosen as the most relevant. Obtained results were confirmed by nuclear magnetic resonance (NMR) spectroscopy. Good predictive ability of this approach demonstrates the potential of IR spectroscopy and chemometrics for screening of heparin quality. This approach, however, is designed as a screening tool and is not considered as a replacement for either of the methods required by USP and FDA.},
  language  = {en}
}
@article{HaegerBongaertsSiegert2022,
  author    = {Haeger, Gerrit and Bongaerts, Johannes and Siegert, Petra},
  title     = {A convenient ninhydrin assay in 96-well format for amino acid-releasing enzymes using an air-stable reagent},
  series = {Analytical Biochemistry},
  journal   = {Analytical Biochemistry},
  number    = {624},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {1096-0309},
  doi       = {10.1016/j.ab.2022.114819},
  pages     = {Artikel 114819},
  year      = {2022},
  abstract  = {An improved and convenient ninhydrin assay for aminoacylase activity measurements was developed using the commercial EZ Nin™ reagent. Alternative reagents from literature were also evaluated and compared. The addition of DMSO to the reagent enhanced the solubility of Ruhemann's purple (RP). Furthermore, we found that the use of a basic, aqueous buffer enhances stability of RP. An acidic protocol for the quantification of lysine was developed by addition of glacial acetic acid. The assay allows for parallel processing in a 96-well format with measurements microtiter plates.},
  language  = {en}
}
@inproceedings{PothMonzonTippkoetteretal.2010,
  author    = {Poth, Sebastian and Monzon, Magaly and Tippk{\"o}tter, Nils and Ulber, Roland},
  title     = {Lignocellulosic biorefinery : process integration of hydrolysis and fermentation},
  series = {Proceedings / 11th European Workshop on Lignocellulosics and Pulp : August 16 - 19, 2010, Hamburg, Germany},
  booktitle = {Proceedings / 11th European Workshop on Lignocellulosics and Pulp : August 16 - 19, 2010, Hamburg, Germany},
  publisher = {vTi},
  address   = {Hamburg},
  pages     = {65 -- 68},
  year      = {2010},
  language  = {en}
}
@article{WeldenJablonskiWegeetal.2021,
  author    = {Welden, Rene and Jablonski, Melanie and Wege, Christina and Keusgen, Michael and Wagner, Patrick Hermann and Wagner, Torsten and Sch{\"o}ning, Michael Josef},
  title     = {Light-Addressable Actuator-Sensor Platform for Monitoring and Manipulation of pH Gradients in Microfluidics: A Case Study with the Enzyme Penicillinase},
  series = {Biosensors},
  volume    = {11},
  journal   = {Biosensors},
  number    = {6},
  publisher = {MDPI},
  address   = {Basel},
  issn      = {2079-6374},
  doi       = {10.3390/bios11060171},
  pages     = {Artikel 171},
  year      = {2021},
  abstract  = {The feasibility of light-addressed detection and manipulation of pH gradients inside an electrochemical microfluidic cell was studied. Local pH changes, induced by a light-addressable electrode (LAE), were detected using a light-addressable potentiometric sensor (LAPS) with different measurement modes representing an actuator-sensor system. Biosensor functionality was examined depending on locally induced pH gradients with the help of the model enzyme penicillinase, which had been immobilized in the microfluidic channel. The surface morphology of the LAE and enzyme-functionalized LAPS was studied by scanning electron microscopy. Furthermore, the penicillin sensitivity of the LAPS inside the microfluidic channel was determined with regard to the analyte's pH influence on the enzymatic reaction rate. In a final experiment, the LAE-controlled pH inhibition of the enzyme activity was monitored by the LAPS.},
  language  = {en}
}
@misc{PothMonzonTippkoetteretal.2010,
  author    = {Poth, S. and Monzon, M. and Tippk{\"o}tter, Nils and Ulber, Roland},
  title     = {Lignocellulose-Bioraffinerie: Simultane Verzuckerung und Fermentation},
  series = {Chemie Ingenieur Technik},
  volume    = {82},
  journal   = {Chemie Ingenieur Technik},
  number    = {9},
  publisher = {Wiley-VCH},
  address   = {Weinheim},
  doi       = {10.1002/cite.201050360},
  pages     = {1568},
  year      = {2010},
  abstract  = {Die am h{\"a}ufigsten genutzten Rohstoffe f{\"u}r die Produktion von Treibstoffen und Chemikalien sind fossilen Ursprungs. Da diese limitiert sind, werden im Hinblick auf die Nachhaltigkeit alternative, erneuerbare Rohstoffquellen intensiv untersucht. Vielversprechend in diesem Kontext sind die in Lignocellulose enthaltenen Zucker, die beispielsweise zur Produktion von Ethanol genutzt werden k{\"o}nnen. In der Regel sind f{\"u}r eine Lig-nocellulose-Bioraffinerie mehrere Prozessschritte notwendig: Vorbehandlung, Verzuckerung und Fermentation. Um diesen Prozess einfacher zu gestalten, ist es m{\"o}glich, die Verzuckerung und die Fermentation in einem Schritt durchzuf{\"u}hren (SSF). Als Substrat wird hier Cellulose-Faserstoff verwendet, der durch das Organosolv-Verfahren aufgeschlossen wurde. Die Hydrolyse erfolgt mit kommerziell erh{\"a}ltlichen Enzymen und f{\"u}r die Fermentation zu Ethanol werden zwei Hefen verwendet. Beim SSF-Verfahren konnte, im Vergleich zur entkoppelten Verfahrensweise, trotz bestehender Unterschiede in den Temperatur-Optima von Enzymen und Hefen eine Steigerung in der Ethanol-Ausbeute von 0,15 auf 0,2 gg⁻¹ beobachtet werden. Um wirtschaftliche Ausbeuten und Konzentrationen des Produkts erzielen zu k{\"o}nnen, ist es notwendig den Prozess weiter zu optimieren. Im Einzelfall muss {\"u}berpr{\"u}ft werden, ob diese Verfahrensweise auch f{\"u}r die Produktion anderer interessanter Stoffe (wie Itacons{\"a}ure, Bernsteins{\"a}ure) geeignet ist.},
  language  = {de}
}
@misc{TippkoetterNeitmannSohlingetal.2009,
  author    = {Tippk{\"o}tter, Nils and Neitmann, E. and Sohling, U. and Ruf, F. and Ulber, Roland},
  title     = {Anaerobe Produktion von ABE-L{\"o}sungsmitteln aus an Bleicherde adsorbiertem {\"O}l},
  series = {Chemie Ingenieur Technik},
  volume    = {81},
  journal   = {Chemie Ingenieur Technik},
  number    = {8},
  publisher = {Wiley-VCH},
  address   = {Weinheim},
  issn      = {0009-286X},
  doi       = {10.1002/cite.200950075},
  pages     = {1217 -- 1218},
  year      = {2009},
  abstract  = {Mit Palm{\"o}l beladene Bleicherde wurde auf die Anwendbarkeit als Rohstoff zur Bildung von Aceton, Ethanol und Butanol (ABE) untersucht. Nach der Abtrennung des entf{\"a}rbten bzw. gebleichten {\"O}ls bestehen 20-40 \% (w/w) des Bleicherder{\"u}ckstands aus adsorbiertem {\"O}l. Somit stellt das Mineral einen wertvollen Rohstoff dar. Zur Produktion der L{\"o}sungsmittel wurde das gebundene {\"O}l hydrolysiert. Das freigesetzte Glycerin diente als Substrat einer nachfolgenden anaeroben Fermentation zu den ABE-L{\"o}sungsmitteln. Die Fermentationen wurden mit verschiedenen Clostridien-St{\"a}mmen durchgef{\"u}hrt, von denen einige lipolytische Aktivit{\"a}t aufweisen. Der {\"O}lgehalt der Bleicherde betrug 28 \% der Adsorbermasse. F{\"u}r die Hydrolyse wurden drei Ans{\"a}tze untersucht: 1. die direkte Fermentation des Adsorbers mit lipolytisch aktiven Clostridien, 2. der Einsatz von Lipasen und die Fermentation des resultierenden {\"U}berstands und 3. die Kofermentation mit einer lipolytisch aktiven Hefe. Jeder der drei Ans{\"a}tze f{\"u}hrte zu einerHydrolyse des {\"O}ls und Wachstum der Mikroorganismen. Der Einsatz von Lipasen resultierte in einer vollst{\"a}ndigen und der schnellsten Hydrolyse des {\"O}ls. Eine Glycerinkonzentration von 13,4 g/L konnte erreicht werden. Die anaerobe Fermentation der verschiedenen Clostridien auf Minimalmedien verlief erfolgreich. Der Vergleich der Fermentationen der Bleicherdehydrolysate zeigte, dass das Hydrolysat wachstumsinhibierende Substanzen enth{\"a}lt. Unter diesen Bedingungen konnte eine Ausbeute von Y P/S = 0,11 erzielt werden. Der Einsatz eines Ionenaustauschers zur Reinigung des Hydrolysats vor der Fermentation resultierte in einer Verbesserung des Wachstums},
  language  = {de}
}
@misc{SiekerTippkoetterMuffleretal.2012,
  author    = {Sieker, T. and Tippk{\"o}tter, Nils and Muffler, K. and Ulber, Roland},
  title     = {Herstellung von Ethanol, Phenols{\"a}uren, organischen S{\"a}uren und Biogas durch vollst{\"a}ndige Nutzung von Grassilage in einer Bioraffinerie},
  series = {Chemie Ingenieur Technik},
  volume    = {84},
  journal   = {Chemie Ingenieur Technik},
  number    = {8},
  publisher = {Wiley-VCH},
  address   = {Weinheim},
  issn      = {0009-286X},
  doi       = {10.1002/cite.201250415},
  pages     = {1297},
  year      = {2012},
  abstract  = {Gr{\"a}ser sind in der Lage, einen großen Teil der f{\"u}r eine biobasierte Wirtschaft ben{\"o}tigten Biomasse zur Verf{\"u}gung zustellen. Um eine ganzj{\"a}hrige Nutzung des Grases zu gew{\"a}hrleisten, muss eine stabile Lagerung des Grases erreicht werden, was z. B. durch Silieren m{\"o}glich ist. Die konservierende Wirkung der Silierung beruht auf der Bildung organischer S{\"a}uren. Um diese zu gewinnen, wird die Silage gepresst, die organischen S{\"a}uren {\"u}ber Fl{\"u}ssig/Fl{\"u}ssig-Extraktion aus dem Presssaft abgetrenntund mittels chromatographischer Methoden weiter aufgereinigt. Im pr{\"a}sentierten Konzept werden die im Presskuchen enthaltenen Lignocellulosen hydrolysiert und die erhaltenen Monosaccharide zu Ethanol fermentiert. Die Phenols{\"a}uren, die in Gr{\"a}sern die Rolle des Lignins {\"u}bernehmen, k{\"o}nnen simultan mit der Hydrolyse der Polysaccharide enzymatisch abgetrennt und als Nebenprodukt gewonnen werden. Die nach der Abtrennung des Ethanols verbleibenden Fermentationsreststoffe werden f{\"u}r die Herstellung von Biogas verwendet.},
  language  = {de}
}
@techreport{BarnatArntzBerneckeretal.2024,
  type      = {Working Paper},
  author    = {Barnat, Miriam and Arntz, Kristian and Bernecker, Andreas and Fissabre, Anke and Franken, Norbert and Goldbach, Daniel and H{\"u}ning, Felix and J{\"o}rissen, J{\"o}rg and Kirsch, Ansgar and Pettrak, J{\"u}rgen and Rexforth, Matthias and Josef, Rosenkranz and Terstegge, Andreas},
  title     = {Strategische Gestaltung von Studieng{\"a}ngen f{\"u}r die Zukunft: Ein kollaborativ entwickeltes Self-Assessment},
  series = {Hochschulforum Digitalisierung - Diskussionspapier},
  journal   = {Hochschulforum Digitalisierung - Diskussionspapier},
  publisher = {Stifterverband f{\"u}r die Deutsche Wissenschaft},
  address   = {Berlin},
  issn      = {2365-7081},
  pages     = {16 Seiten},
  year      = {2024},
  abstract  = {Das Diskussionspapier beschreibt einen Prozess an der FH Aachen zur Entwicklung und Implementierung eines Self-Assessment-Tools f{\"u}r Studieng{\"a}nge. Dieser Prozess zielte darauf ab, die Relevanz der Themen Digitalisierung, Internationalisierung und Nachhaltigkeit in Studieng{\"a}ngen zu st{\"a}rken. Durch Workshops und kollaborative Entwicklung mit Studiendekan:innen entstand ein Fragebogen, der zur Reflexion und strategischen Weiterentwicklung der Studieng{\"a}nge dient.},
  language  = {de}
}
@misc{TippkoetterWulfhorstMogueetal.2014,
  author    = {Tippk{\"o}tter, Nils and Wulfhorst, H. and Mogue, N. and M{\"o}hring, S. and Roth, J. and Ulber, Roland},
  title     = {Spektrometrische Messung und Modellierung der enzymatischen Hydrolyse von Biomasse nach Organosolv- und Liquid Hot Water-Aufschl{\"u}ssen (LHW)},
  series = {Chemie Ingenieur Technik},
  volume    = {86},
  journal   = {Chemie Ingenieur Technik},
  number    = {9},
  publisher = {Wiley-VCH},
  address   = {Weinheim},
  issn      = {0009-286X},
  doi       = {10.1002/cite.201450269},
  pages     = {1584},
  year      = {2014},
  abstract  = {In diesem Beitrag wird die NIR- und MIR-Spektrometrie in Kombination mit multivariaten Kalibrationsmodellen zur Analyse von Monosacchariden und Cellulose aus Biomasse etabliert. Spektrengemischter Standardl{\"o}sungen mit definierten Glucose- und Xylosekonzentrationen in Wasser werden im NIR-(Lambda 750, Perkin Elmer, USA) und MIR-Bereich (Spektrum 100, PerkinElmer) in Gegenwart von entweder Carboxymethylcellulose oder Grasfasern aufgenommen. Darauf basierend werden Kalibrationsmodelle (Unscrambler®, CAMO-Software AS, Norwegen) entwickelt und zur Vorhersage der Zuckerkonzentration in den Hydrolyseproben und der Celluloseanteile angewendet. Dar{\"u}ber hinaus wird die Partikelgr{\"o}ße der Rohstoffe bestimmt. Die Messergebnisse bilden die experimentelle Basis f{\"u}r die numerische Modellierung der Reaktionskinetik der enzymatischen Hydrolyse von Lignocellulose. Das Modell kombiniert die Bilanzierung der Partikelgr{\"o}ßenverteilungen mit der Multienzymkinetik. Dabei werden neben der Partikelgr{\"o}ßenverteilung und der Substratkonzentration die Zusammensetzung der Rohstoffe nach Vorbehandlung sowie die Produktinhibierung und mehrere enzymatische Aktivit{\"a}ten ber{\"u}cksichtigt. Das Modell erm{\"o}glicht es, die Partikelgr{\"o}ßenverteilungen und die Konzentrationen der Substrate und Produkte w{\"a}hrend der Hydrolyse vorherzusagen und die kinetischen Parameter im Batch- sowie im Fed-Batch-Reaktor zu bestimmen.},
  language  = {de}
}