@article{WincklerKruegerSchnitzleretal.2014, author = {Winckler, Silvia and Krueger, Rolf and Schnitzler, Thomas and Zang, Werner and Fischer, Rainer and Biselli, Manfred}, title = {A sensitive monitoring system for mammalian cell cultivation processes: a PAT approach}, series = {Bioprocess and biosystems engineering}, volume = {37}, journal = {Bioprocess and biosystems engineering}, number = {5}, publisher = {Springer}, address = {Berlin, Heidelberg}, issn = {1615-7591 (Print) 1615-7605 (Online)}, doi = {10.1007/s00449-013-1062-8}, pages = {901 -- 912}, year = {2014}, abstract = {Biopharmaceuticals such as antibodies are produced in cultivated mammalian cells, which must be monitored to comply with good manufacturing practice. We, therefore, developed a fully automated system comprising a specific exhaust gas analyzer, inline analytics and a corresponding algorithm to precisely determine the oxygen uptake rate, carbon dioxide evolution rate, carbon dioxide transfer rate, transfer quotient and respiratory quotient without interrupting the ongoing cultivation, in order to assess its reproducibility. The system was verified using chemical simulation experiments and was able to measure the respiratory activity of hybridoma cells and DG44 cells (derived from Chinese hamster ovary cells) with satisfactory results at a minimum viable cell density of ~2.0 × 10⁵ cells ml⁻¹. The system was suitable for both batch and fed-batch cultivations in bubble-aerated and membrane-aerated reactors, with and without the control of pH and dissolved oxygen.}, language = {en} } @article{HeinzeMangPeteretal.2014, author = {Heinze, Daniel and Mang, Thomas and Peter, Karin and M{\"o}ller, Martin and Weichold, Oliver}, title = {Synthesis of low molecular weight poly(vinyl acetate) and its application as plasticizer}, series = {Journal of applied polymer science}, volume = {131}, journal = {Journal of applied polymer science}, number = {9}, publisher = {Wiley}, address = {New York}, issn = {1097-4628 (E-Journal); 0021-8995 (Print)}, doi = {10.1002/app.40226}, pages = {Article No. 40226}, year = {2014}, abstract = {Poly(vinyl acetate), PVAc, with a degree of polymerization Xn = 10 was prepared by chain-transfer radical polymerization using carbon tetrachloride and used as oligomeric plasticizer for commercial PVAc. However, the chlorinated chain ends cause a low thermal stability requiring mild Cl/H substitution. The product exhibits high thermal stability and excellent melt-compounding properties. Blends of oligomeric and commercial PVAc show single glass transition temperatures which decrease with higher oligomer content and exhibit small negative deviations from Fox' linear additivity rule. This indicates plasticization and miscibility being mainly due to entropic effects. Injection-moulded thick specimens show ductile behaviour at oligomer contents >10 wt \%, while sheets with a thickness of 0.2-0.5 mm appear flexible already at 7.5 wt \%. The oxygen permeability coefficients are an order of magnitude lower than those of low-density polyethylene. Due to the sum of their properties, the plasticized sheets present a promising alternative in the preparation of barrier materials.}, language = {en} } @book{Berndt2014, author = {Berndt, Heinz}, title = {Neue Kondensations-Methoden zur Synthese definierter Peptid-Derivate}, address = {Aachen}, pages = {XII, VI, 207 S. : graph. Darst.}, year = {2014}, language = {de} } @article{WangDruckenmuellerElbersetal.2014, author = {Wang, Ren-Qi and Druckenm{\"u}ller, Katharina and Elbers, Gereon and Guenther, Klaus and Crou{\´e}, Jean-Philippe}, title = {Analysis of aquatic-phase natural organic matter by optimized LDI-MS method}, series = {Journal of mass spectrometry}, volume = {49}, journal = {Journal of mass spectrometry}, number = {2}, publisher = {Wiley}, address = {Bognor Regis}, issn = {1096-9888}, doi = {10.1002/jms.3321}, pages = {154 -- 160}, year = {2014}, abstract = {The composition and physiochemical properties of aquatic-phase natural organic matter (NOM) are most important problems for both environmental studies and water industry. Laser desorption/ionization (LDI) mass spectrometry facilitated successful examinations of NOM, as humic and fulvic acids in NOM are readily ionized by the nitrogen laser. In this study, hydrophobic NOMs (HPO NOMs) from river, reservoir and waste water were characterized by this technique. The effect of analytical variables like concentration, solvent composition and laser energy was investigated. The exact masses of small molecular NOM moieties in the range of 200-1200 m/z were determined in reflectron mode. In addition, spectra of post-source-decay experiments in this range showed that some compounds from different natural NOMs had the same fragmental ions. In the large mass range of 1200-15 000 Da, macromolecules and their aggregates were found in HPO NOMs from natural waters. Highly humic HPO exhibited mass peaks larger than 8000 Da. On the other hand, the waste water and reservoir water mainly had relatively smaller molecules of about 2000 Da. The LDI-MS measurements indicated that highly humic river waters were able to form large aggregates and membrane foulants, while the HPO NOMs from waste water and reservoir water were unlikely to form large aggregates. Copyright © 2014 John Wiley \& Sons, Ltd.}, language = {en} } @article{HeineHerrmannSelmeretal.2014, author = {Heine, A. and Herrmann, G. and Selmer, Thorsten and Terwesten, F. and Buckel, W. and Reuter, K.}, title = {High resolution crystal structure of clostridium propionicum β-Alanyl-CoA:Ammonia Lyase, a new member of the "Hot Dog Fold" protein superfamily}, series = {Proteins}, volume = {82}, journal = {Proteins}, number = {9}, publisher = {Wiley-Liss}, address = {New York}, issn = {1097-0134 (E-Journal); 0887-3585 (Print)}, doi = {10.1002/prot.24557}, pages = {2041 -- 2053}, year = {2014}, abstract = {Clostridium propionicum is the only organism known to ferment β-alanine, a constituent of coenzyme A (CoA) and the phosphopantetheinyl prosthetic group of holo-acyl carrier protein. The first step in the fermentation is a CoA-transfer to β-alanine. Subsequently, the resulting β-alanyl-CoA is deaminated by the enzyme β-alanyl-CoA:ammonia lyase (Acl) to reversibly form ammonia and acrylyl-CoA. We have determined the crystal structure of Acl in its apo-form at a resolution of 0.97 {\AA} as well as in complex with CoA at a resolution of 1.59 {\AA}. The structures reveal that the enyzme belongs to a superfamily of proteins exhibiting a so called "hot dog fold" which is characterized by a five-stranded antiparallel β-sheet with a long α-helix packed against it. The functional unit of all "hot dog fold" proteins is a homodimer containing two equivalent substrate binding sites which are established by the dimer interface. In the case of Acl, three functional dimers combine to a homohexamer strongly resembling the homohexamer formed by YciA-like acyl-CoA thioesterases. Here, we propose an enzymatic mechanism based on the crystal structure of the Acl·CoA complex and molecular docking. Proteins 2014; 82:2041-2053. © 2014 Wiley Periodicals, Inc.}, language = {en} } @article{TakenagaBiselliSchnitzleretal.2014, author = {Takenaga, Shoko and Biselli, Manfred and Schnitzler, Thomas and {\"O}hlschl{\"a}ger, Peter and Wagner, Torsten and Sch{\"o}ning, Michael Josef}, title = {Toward multi-analyte bioarray sensors: LAPS-based on-chip determination of a Michaelis-Menten-like kinetics for cell culturing}, series = {Physica status solidi A : Applications and materials science}, volume = {211}, journal = {Physica status solidi A : Applications and materials science}, number = {6}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1521-396X (E); 1862-6319 (E-Journal); 0031-8965 (Print); 1862-6300 (Print)}, doi = {10.1002/pssa.201330464}, pages = {1410 -- 1415}, year = {2014}, abstract = {The metabolic activity of Chinese hamster ovary (CHO) cells was observed using a light-addressable potentiometric sensor (LAPS). The dependency toward different glucose concentrations (17-200 mM) follows a Michaelis-Menten kinetics trajectory with Kₘ = 32.8 mM, and the obtained Kₘ value in this experiment was compared with that found in literature. In addition, the pH shift induced by glucose metabolism of tumor cells transfected with the HPV-16 genome (C3 cells) was successfully observed. These results indicate the possibility to determine the tumor cells metabolism with a LAPS-based measurement device.}, language = {en} } @article{WhiteheadOehlschlaegerAlmajhdietal.2014, author = {Whitehead, Mark and {\"O}hlschl{\"a}ger, Peter and Almajhdi, Fahad N. and Alloza, Leonor and Marz{\´a}bal, Pablo and Meyers, Ann E. and Hitzeroth, Inga I. and Rybicki, Edward P.}, title = {Human papillomavirus (HPV) type 16 E7 protein bodies cause tumour regression in mice}, series = {BMC cancer}, journal = {BMC cancer}, number = {14:367}, publisher = {BioMed Central}, address = {London}, issn = {1471-2407}, doi = {10.1186/1471-2407-14-367}, pages = {1 -- 15}, year = {2014}, language = {en} } @article{KueppersSteffenHellmuthetal.2014, author = {K{\"u}ppers, Tobias and Steffen, Victoria and Hellmuth, Hendrik and O'Connell, Timothy and Bongaerts, Johannes and Maurer, Karl-Heinz and Wiechert, Wolfgang}, title = {Developing a new production host from a blueprint: Bacillus pumilus as an industrial enzyme producer}, series = {Microbial cell factories}, volume = {13}, journal = {Microbial cell factories}, publisher = {BioMed Central}, address = {London}, issn = {1475-2859 (E-Journal)}, doi = {10.1186/1475-2859-13-46}, pages = {Article No. 46}, year = {2014}, language = {en} } @article{GuoMiyamotoWagneretal.2014, author = {Guo, Yuanyuan and Miyamoto, Ko-ichiro and Wagner, Torsten and Sch{\"o}ning, Michael Josef and Yoshinobu, Tatsuo}, title = {Theoretical study and simulation of light-addressable potentiometric sensors}, series = {Physica status solidi (A) : applications and materials}, volume = {211}, journal = {Physica status solidi (A) : applications and materials}, number = {6}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {0031-8965}, doi = {10.1002/pssa.201330354}, pages = {1467 -- 1472}, year = {2014}, abstract = {The light-addressable potentiometric sensor (LAPS) is a semiconductor-based potentiometric sensor using a light probe with an ability of detecting the concentration of biochemical species in a spatially resolved manner. As an important biomedical sensor, research has been conducted to improve its performance, for instance, to realize high-speed measurement. In this work, the idea of facilitating the device-level simulation, instead of using an equivalent-circuit model, is presented for detailed analysis and optimization of the performance of the LAPS. Both carrier distribution and photocurrent response have been simulated to provide new insight into both amplitude-mode and phase-mode operations of the LAPS. Various device parameters can be examined to effectively design and optimize the LAPS structures and setups for enhanced performance.}, language = {en} } @masterthesis{Kobus2014, type = {Bachelor Thesis}, author = {Kobus, Timm}, title = {Untersuchung des unterschiedlichen Reduktionsverhaltens von unterschiedlich para-substituierten Acetophenonen mit Chiralidon R \& S}, school = {Fachhochschule Aachen}, pages = {128 S.}, year = {2014}, language = {de} }