TY - JOUR A1 - Immel, Timo A1 - Grützke, Martin A1 - Späte, Anne-Katrin A1 - Groth, Ulrich A1 - Öhlschläger, Peter A1 - Huhn, Thomas T1 - Synthesis and X-ray structure analysis of a heptacoordinate titanium(IV)-bis-chelate with enhanced in vivo antitumor efficacy JF - Chemical Communications N2 - Chelate stabilization of a titanium(IV)–salan alkoxide by ligand exchange with 2,6-pyridinedicarboxylic acid (dipic) resulted in heptacoordinate complex 3 which is not redox-active, stable on silica gel and has increased aqueous stability. 3 is highly toxic in HeLa S3 and Hep G2 and has enhanced antitumor efficacy in a mouse cervical-cancer model. Y1 - 2012 U6 - http://dx.doi.org/10.1039/C2CC31624B SN - 1364-548X VL - 48 IS - 46 SP - 5790 EP - 5792 PB - Royal Society of Chemistry CY - Cambridge ER - TY - CHAP A1 - Srivastava, Alok A1 - Knolle, Friedhart A1 - Hoyler, Friedrich A1 - Scherer, Ulrich W. A1 - Schnug, Ewald T1 - Uranium Toxicity in the State of Punjab in North-Western India T2 - Management of Natural Resources in a Changing Environment N2 - Lately there has been an increasing concern about uranium toxicity in some districts of Punjab State located in the North Western part of India after the publication of a report (Blaurock-Busch et al. 2010) which showed that the concentration of uranium in hair and urine of children suffering from physical deformities, neurological and mental disorder from Malwa region (Fig. 1) of Punjab State was manifold higher than the reference ranges. A train which connects the affected region with the nearby city of Bikaner which has a Cancer Hospital has been nicknamed as Cancer Express due to the frenzy generated on account of uranium related toxicity. Y1 - 2015 SN - 978-3-319-12559-6 U6 - http://dx.doi.org/10.1007/978-3-319-12559-6_21 SP - 271 EP - 275 PB - Springer CY - Cham ER - TY - JOUR A1 - Cehreli, Ruksan A1 - Akpinar, Hale A1 - Temiz Artmann, Aysegül A1 - Sagol, Ozgul T1 - Effects of Glutamine and Omega-3 Fatty Acids on Erythrocyte Deformability and Oxidative Damage in Rat Model of Enterocolitis JF - Gastroenterology Research Y1 - 2015 U6 - http://dx.doi.org/10.14740/gr683w SN - 1918-2813 VL - 8 IS - 5 SP - 265 EP - 273 ER - TY - PAT A1 - O'Connell, Timothy A1 - Siegert, Petra A1 - Maurer, Karl-Heinz A1 - Schiedel, Marc-Steffen A1 - Vockenroth, Inga Kerstin T1 - Method for improving the cleaning action of a detergent or cleaning agent [Internationale Patentanmeldung] T1 - Verfahren zur Verbesserung der Reinigungsleistung eines Wasch- oder Reinigungsmittels Y1 - 2010 SP - 1 EP - 15 PB - WIPO CY - Genf ER - TY - CHAP A1 - Breuer, Lars A1 - Raue, Markus A1 - Mang, Thomas A1 - Schöning, Michael Josef A1 - Thoelen, Ronald A1 - Wagner, Torsten T1 - Light-stimulated hydrogel actuators with incorporated graphene oxide for microfluidic applications T2 - 12. Dresdner Sensor-Symposium 2015 Y1 - 2015 U6 - http://dx.doi.org/10.5162/12dss2015/P5.8 SP - 206 EP - 209 ER - TY - JOUR A1 - Breuer, Lars A1 - Raue, Markus A1 - Strobel, M. A1 - Mang, Thomas A1 - Schöning, Michael Josef A1 - Thoelen, R. A1 - Wagner, Torsten T1 - Hydrogels with incorporated graphene oxide as light-addressable actuator materials for cell culture environments in lab-on-chip systems JF - Physica status solidi (a) N2 - Abstractauthoren Graphene oxide (GO) nanoparticles were incorporated in temperature-sensitive Poly(N-isopropylacrylamide) (PNIPAAm) hydrogels. The nanoparticles increase the light absorption and convert light energy into heat efficiently. Thus, the hydrogels with GO can be stimulated spatially resolved by illumination as it was demonstrated by IR thermography. The temporal progression of the temperature maximum was detected for different concentrations of GO within the polymer network. Furthermore, the compatibility of PNIPAAm hydrogels with GO and cell cultures was investigated. For this purpose, culture medium was incubated with hydrogels containing GO and the viability and morphology of chinese hamster ovary (CHO) cells was examined after several days of culturing in presence of this medium. Y1 - 2016 U6 - http://dx.doi.org/10.1002/pssa.201533056 SN - 1862-6300 VL - 213 IS - 6 SP - 1520 EP - 1525 PB - Wiley-VCH CY - Weinheim ER - TY - CHAP A1 - Kasper, Katharina A1 - Schiffels, Johannes A1 - Krafft, Simone A1 - Kuperjans, Isabel A1 - Elbers, Gereon A1 - Selmer, Thorsten T1 - Biogas Production on Demand Regulated by Butyric Acid Addition T2 - IOP Conference Series: Earth and Environmental Science. Bd. 32 Y1 - 2016 U6 - http://dx.doi.org/10.1088/1755-1315/32/1/012009 SN - 1755-1315 N1 - ICARET 2016, International Conference on Advances in Renewable Energy and Technologies, Putrajaya, MY, Feb 23-25, 2016 VL - 32 SP - 012009/1 EP - 012009/4 ER - TY - JOUR A1 - Niedermeyer, Angela A1 - Zhou, Bei A1 - Dursun, Gözde A1 - Temiz Artmann, Aysegül A1 - Markert, Bernd T1 - An examination of tissue engineered scaffolds in a bioreactor JF - Proceedings in Applied Mathematics and Mechanics PAMM N2 - Replacement tissues, designed to fill in articular cartilage defects, should exhibit the same properties as the native material. The aim of this study is to foster the understanding of, firstly, the mechanical behavior of the material itself and, secondly, the influence of cultivation parameters on cell seeded implants as well as on cell migration into acellular implants. In this study, acellular cartilage replacement material is theoretically, numerically and experimentally investigated regarding its viscoelastic properties, where a phenomenological model for practical applications is developed. Furthermore, remodeling and cell migration are investigated. Y1 - 2016 U6 - http://dx.doi.org/10.1002/pamm.201610038 SN - 1617-7061 N1 - Joint Annual Meeting of DMV and GAMM 2016, 87th Annual Meeting of the International Association of Applied Mathematics and Mechanics (GAMM) and Deutsche Mathematiker-Vereinigung (DMV), Braunschweig, DE, Mar 7-11, 2016 VL - 16 IS - 1 SP - 99 EP - 100 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Heinze, D. A1 - Mang, Thomas A1 - Popescu, C. A1 - Weichold, O. T1 - Effect of side chain length and degree of polymerization on the decomposition and crystallization behaviour of chlorinated poly(vinyl ester) oligomers JF - Thermochimica Acta N2 - Four members of a homologous series of chlorinated poly(vinyl ester) oligomers CCl₃–(CH₂CH (OCO(CH₂)ₘCH₃))ₙ–Cl with degrees of polymerization of 10 and 20 were prepared by telomerisation using carbon tetrachloride. The number of side chain carbon atoms ranges from 2 (poly(vinyl acetate) to 18 (poly(vinyl stearate)). The effect of the n-alkyl side chain length and of the degree of polymerization on the thermal stability and crystallization behaviour of the synthesized compounds was investigated. All oligomers degrade in two major steps by first losing HCl and side chains with subsequent breakdown of the backbone. The members with short side chains, up to poly(vinyl octanoate), are amorphous and show internal plasticization, whereas those with high number of side chain carbon atoms are semi-crystalline due to side-chain crystallization. A better packing for poly(vinyl stearate) is also noticeable. The glass transition and melting temperatures as well as the onset temperature of decomposition are influenced to a larger extent by the side chain length than by the degree of polymerization. Thermal stability is improved if both the size and number of side chains increase, but only a long side chain causes a significant increase of the resistance to degradation. This results in a stabilization of PVAc so that oligomers from poly(vinyl octanoate) on are stable under atmospheric conditions. Thus, the way to design stable, chlorinated PVEs oligomers is to use a long n-alkyl side chain. Y1 - 2016 U6 - http://dx.doi.org/10.1016/j.tca.2016.05.015 SN - 0040-6031 (electronic) VL - 637 SP - 143 EP - 153 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Molinnus, Denise A1 - Sorich, Maren A1 - Bartz, Alexander A1 - Siegert, Petra A1 - Willenberg, Holger S. A1 - Lisdat, Fred A1 - Poghossian, Arshak A1 - Keusgen, Michael A1 - Schöning, Michael Josef T1 - Towards an adrenaline biosensor based on substrate recycling amplification in combination with an enzyme logic gate JF - Sensors and Actuators B: Chemical N2 - An amperometric biosensor using a substrate recycling principle was realized for the detection of low adrenaline concentrations (1 nM) by measurements in phosphate buffer and Ringer’s solution at pH 6.5 and pH 7.4, respectively. In proof-of-concept experiments, a Boolean logic-gate principle has been applied to develop a digital adrenaline biosensor based on an enzyme AND logic gate. The obtained results demonstrate that the developed digital biosensor is capable for a rapid qualitative determination of the presence/absence of adrenaline in a YES/NO statement. Such digital biosensor could be used in clinical diagnostics for the control of a correct insertion of a catheter in the adrenal veins during adrenal venous-sampling procedure. Y1 - 2016 U6 - http://dx.doi.org/10.1016/j.snb.2016.06.064 SN - 0925-4005 VL - 237 SP - 190 EP - 195 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Ghosch, S. A1 - Baier, M. A1 - Schütz, J. A1 - Schneider, Felix A1 - Scherer, Ulrich W. T1 - Analysis of electronic autoradiographs by mathematical post-processing JF - Radiation Effects and Defects in Solids: Incorporating plasma science and plasma technology N2 - Autoradiography is a well-established method of nuclear imaging. When different radionuclides are present simultaneously, additional processing is needed to distinguish distributions of radionuclides. In this work, a method is presented where aluminium absorbers of different thickness are used to produce images with different cut-off energies. By subtracting images pixel-by-pixel one can generate images representing certain ranges of β-particle energies. The method is applied to the measurement of irradiated reactor graphite samples containing several radionuclides to determine the spatial distribution of these radionuclides within pre-defined energy windows. The process was repeated under fixed parameters after thermal treatment of the samples. The greyscale images of the distribution after treatment were subtracted from the corresponding pre-treatment images. Significant changes in the intensity and distribution of radionuclides could be observed in some samples. Due to the thermal treatment parameters the most significant differences were observed in the ³H and ¹⁴C inventory and distribution. Y1 - 2016 U6 - http://dx.doi.org/10.1080/10420150.2016.1155587 SN - 1029-4953 VL - 171 IS - 1-2 SP - 161 EP - 172 PB - Taylor & Francis CY - London ER - TY - JOUR A1 - Pasteur, Aline A1 - Tippkötter, Nils A1 - Kampeis, Percy A1 - Ulber, Roland T1 - Optimization of high gradient magnetic separation filter units for the purification of fermentation products JF - IEEE TRANSACTIONS ON MAGNETICS N2 - 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. Y1 - 2014 U6 - http://dx.doi.org/10.1109/TMAG.2014.2325535 SN - 0018-9464 N1 - Article Sequence Number: 5000607 INSPEC Accession Number: 14663042 VL - 50 IS - 10 SP - Artikel 5000607 PB - IEEE CY - New York, NY ER - TY - JOUR A1 - Tippkötter, Nils A1 - Wollny, Steffen A1 - Suck, Kirstin A1 - Sohling, Ulrich A1 - Ruf, Friedrich A1 - Ulber, Roland T1 - Recycling of spent oil bleaching earth as source of glycerol for the anaerobic production of acetone, butanol, and ethanol with Clostridium diolis and lipolytic Clostridium lundense JF - Engineering in Life Sciences N2 - A major part of edible oil is subjected to bleaching procedures, primarily with minerals applied as adsorbers. Their recycling is currently done either by regaining the oil via organic solvent extraction or by using the spent bleaching earth (SBE) as additive for animal feed, etc. As a new method, the reutilization of the by-product SBE for the microbiologic formation of acetone, butanol, and ethanol (ABE) is presented as proof-of-concept. The SBE was taken from a palm oil cleaning process. The recycling concept is based on the application of lipolytic clostridia strains. Due to considerably long fermentation times, co-fermentation with Candida rugosa and enzymatic hydrolyses of the bound oil with a subsequent clostridia fermentation are shown as alternative routes. Anaerobic fermentations under comparison of different clostridia strains were performed with glycerol media, enzymatically hydrolyzed palm oil and SBE. Solutes, side product compositions and productivities were quantified via HPLC. A successful production of ABE solutes from SBE has been done with a yield of 0.15 g butanol per gram of bound glycerol. Thus, the biotechnological recycling of the waste stream is possible in principle. Inhibition of the substrate suspension has been observed. A chromatographic ion-exchange of substrates increased the biomass concentration. Y1 - 2014 U6 - http://dx.doi.org/10.1002/elsc.201300113 SN - 1618-2863 VL - 14 IS - 4 SP - 425 EP - 432 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Thiel, Alexander A1 - Tippkötter, Nils A1 - Suck, Kirstin A1 - Sohling, Ulrich A1 - Ruf, Friedrich A1 - Ulber, Roland T1 - New zeolite adsorbents for downstream processing of polyphenols from renewable resources JF - Engineering in Life Sciences N2 - Commercial materials with polyvinylpolypyrrolidone and polymeric amberlites (XAD7HP, XAD16) are commonly used for the adsorptive downstream processing of polyphenols from renewable resources. In this study, beta-zeolite-based adsorbent systems were examined, and their properties were compared to organic resins. Batch adsorption experiments were conducted with synthetic solutions of major polyphenols. Adsorption isotherms and desorption characteristics of individual adsorbent were determined based on these results. Maximum adsorption capacities were calculated using the Langmuir model. For example, the zeolites had capacities up to 203.2 mg/g for ferulic acid. To extend these results to a complex system, additional experiments were performed on rapeseed meal and wheat seed extracts as representative renewable resources. HPLC analysis showed that with 7.5% w/v, which is regarded as the optimum amount of zeolites, zeolites A and B could bind 100% of the major polyphenols as well as release polyphenols at high yields. Additionally, regeneration experiments were performed with isopropyl alcohol at 99°C to evaluate how zeolites regenerate under mild conditions. The results showed only a negligible loss of adsorption capacity and no loss of desorption capacity. In summary, it was concluded that beta-zeolites were promising adsorbents for developing new processes to isolate polyphenols from renewable resources. Y1 - 2013 U6 - http://dx.doi.org/10.1002/elsc.201200188 VL - 13 IS - 3 SP - 239 EP - 246 PB - Wiley CY - Weinheim ER - TY - JOUR A1 - Tippkötter, Nils A1 - Al-Kaidy, Huschyar A1 - Wollny, Steffen A1 - Ulber, Roland T1 - Functionalized magnetizable particles for downstream processing in single-use systems JF - Chemie Ingenieur Technik N2 - Biotechnological downstream processing is usually an elaborate procedure, requiring a multitude of unit operations to isolate the target component. Besides the disadvantageous space-time yield, the risks of cross-contaminations and product loss grow fast with the complexity of the isolation procedure. A significant reduction of unit operations can be achieved by application of magnetic particles, especially if these are functionalized with affinity ligands. As magnetic susceptible materials are highly uncommon in biotechnological processes, target binding and selective separation of such particles from fermentation or reactions broths can be done in a single step. Since the magnetizable particles can be produced from iron salts and low priced polymers, a single-use implementation of these systems is highly conceivable. In this article, the principles of magnetizable particles, their synthesis and functionalization are explained. Furthermore, applications in the area of reaction engineering, microfluidics and downstream processing are discussed focusing on established single-use technologies and development potential. Y1 - 2013 U6 - http://dx.doi.org/10.1002/cite.201200130 VL - 85 IS - 1-2: Special Issue: Single-Use Technology SP - 76 EP - 86 PB - Wiley CY - Weinheim ER - TY - JOUR A1 - Sieker, Tim A1 - Neuner, Andreas A1 - Dimitrova, Darina A1 - Tippkötter, Nils A1 - Muffler, Kai A1 - Bart, Hans-Jörg A1 - Heinzle, Elmar A1 - Ulber, Roland T1 - Ethanol production from grass silage by simultaneous pretreatment, saccharification and fermentation: First steps in the process development JF - Engineering in Life Sciences N2 - Grass silage provides a great potential as renewable feedstock. Two fractions of the grass silage, a press juice and the fiber fraction, were evaluated for their possible use for bioethanol production. Direct production of ethanol from press juice is not possible due to high concentrations of organic acids. For the fiber fraction, alkaline peroxide or enzymatic pretreatment was used, which removes the phenolic acids in the cell wall. In this study, we demonstrate the possibility to integrate the enzymatic pretreatment with a simultaneous saccharification and fermentation to achieve ethanol production from grass silage in a one-process step. Achieved yields were about 53 g ethanol per kg silage with the alkaline peroxide pretreatment and 91 g/kg with the enzymatic pretreatment at concentrations of 8.5 and 14.6 g/L, respectively. Furthermore, it was shown that additional supplementation of the fermentation medium with vitamins, trace elements and nutrient salts is not necessary when the press juice is directly used in the fermentation step. Y1 - 2011 U6 - http://dx.doi.org/10.1002/elsc.201000160 N1 - Special Issue "Bioprocess‐oriented plant design" VL - 11 IS - 4 SP - 436 EP - 442 PB - Wiley CY - Weinheim ER - TY - JOUR A1 - Poth, Sebastian A1 - Monzon, Magaly A1 - Tippkötter, Nils A1 - Ulber, Roland T1 - Lignocellulosic biorefinery: Process integration of hydrolysis and fermentation (SSF process) JF - Holzforschung N2 - The aim of the present work is the process integration and the optimization of the enzymatic hydrolysis of wood and the following fermentation of the products to ethanol. The substrate is a fiber fraction obtained by organosolv pre-treatment of beech wood. For the ethanol production, a co-fermentation by two different yeasts (Saccharomyces cerevisiae and Pachysolen tannophilus) was carried out to convert glucose as well as xylose. Two approaches has been followed: 1. A two step process, in which the hydrolysis of the fiber fraction and the fermentation to product are separated from each other. 2. A process, in which the hydrolysis and the fermentation are carried out in one single process step as simultaneous saccharification and fermentation (SSF). Following the first approach, a yield of about 0.15 g ethanol per gram substrate can be reached. Based on the SSF, one process step can be saved, and additionally, the gained yield can be raised up to 0.3 g ethanol per gram substrate. Y1 - 2011 N1 - 11th EWLP, Hamburg, Germany, August 16–19, 2010 VL - 65 IS - 5 SP - 633 EP - 637 PB - De Gruyter CY - Berlin ER - TY - JOUR A1 - Rösch, C. A1 - Kratz, F. A1 - Hering, T. A1 - Trautmann, S. A1 - Umanskaya, N. A1 - Tippkötter, Nils A1 - Müller-Renno, C.M. A1 - Ulber, R. A1 - Hannig, M. A1 - Ziegler, C. T1 - Albumin-lysozyme interactions: cooperative adsorption on titanium and enzymatic activity JF - Colloids and Surfaces B: Biointerfaces N2 - 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. Y1 - 2016 U6 - http://dx.doi.org/10.1016/j.colsurfb.2016.09.048 VL - 149 IS - 1 SP - 115 EP - 121 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Roth, Jasmine A1 - Tippkötter, Nils T1 - Evaluation of lignocellulosic material for butanol production using enzymatic hydrolysate medium JF - Cellulose Chemistry and Technology N2 - 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. Y1 - 2016 VL - 50 IS - 3-4 SP - 405 EP - 410 PB - Editura Academiei Romane CY - Bukarest ER - TY - JOUR A1 - Al-Kaidy, Huschyar A1 - Tippkötter, Nils T1 - Superparamagnetic hydrophobic particles as shell material for digital microfluidic droplets and proof-of-principle reaction assessments with immobilized laccase JF - Engineering in Life Sciences N2 - In the field of biotechnology and molecular biology, the use of small liquid volumes has significant advantages. In particular, screening and optimization runs with acceptable amounts of expensive and hardly available catalysts, reagents, or biomolecules are feasible with microfluidic technologies. The presented new microfluidic system is based on the inclusion of small liquid volumes by a protective shell of magnetizable microparticles. Hereby, discrete aqueous microreactor drops with volumes of 1–30 μL can be formed on a simple planar surface. A digital movement and manipulation of the microreactor is performed by overlapping magnetic forces. The magnetic forces are generated by an electrical coil matrix positioned below a glass plate. With the new platform technology, several discrete reaction compartments can be moved simultaneously on one surface. Due to the magnetic fields, the reactors can even be merged to initiate reactions by mixing or positioned above surface-immobilized catalysts and then opened by magnetic force. Comparative synthesis routes of the magnetizable shell particles and superhydrophobic glass slides including their performance and stability with the reaction platform are described. The influence of diffusive mass transport during the catalyzed reaction is discussed by evaluation finite element model of the microreactor. Furthermore, a first model dye reaction of the enzyme laccase has been established. Y1 - 2016 U6 - http://dx.doi.org/10.1002/elsc.201400124 VL - 16 IS - 3 SP - 222 EP - 230 PB - Wiley-VCH CY - Weinheim ER -