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It is shown that a standard model in crystal plasticity for which only rigid body motions have finite elastic energy can be approximated in the sense of Γ-convergence by models with more general elastic potentials. (© 2010 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
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Carolin Alexandra Rickert Theresa Monika Lutz Matthias Marczynski Oliver Lieleg 《Macromolecular bioscience》2020,20(7)
Mucin glycoproteins, the macromolecular components of mucus, combine a broad range of biomedically important properties. Among those is the ability of mucin solutions to act as excellent lubricants. However, to be able to use purified, endogenous mucin glycoproteins as components of a biomedical product, the mucins need to be sterile; this, in turn, makes it necessary to subject the mucins to quite harsh physical treatments, such as heat exposure, autoclaving, UV‐, or γ‐irradiation, which might compromise the functionality of the glycoproteins. Here, it is shown that mucins are indeed able to withstand most of those treatments without suffering significant lubrication impairment or structural degradation. Among those treatments, which left the mucins unharmed, γ‐irradiation is identified to be the most powerful one in terms of inactivating microbial contaminations. The obtained results demonstrate a remarkable sturdiness of mucins, which opens up broad possibilities for them to be further processed into materials, e.g., as parts of biomedical products. 相似文献
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Frank Kirschhöfer Annika Rieder Carolin Prechtl Boris Kühl Kristina Sabljo Christof Wöll Ursula Obst Gerald Brenner-Weiß 《Analytica chimica acta》2013
Proteinaceous conditioning films (pCFs) are thought to play a key role in microbial adhesion, leading to the fouling of technical and biomedical devices and biofilm formation, which in turn causes material damage or persistent infections, respectively. However, little is definitively known about the process of surface conditioning via proteins. Herein, we demonstrate the potential of quartz crystal microbalance with dissipation coupled to MALDI-ToF mass spectrometry (QCM-D-MALDI) to investigate protein adsorption on different surfaces, enabling both the monitoring of CF formation and the determination of the molecular composition of CFs. After running QCM-D experiments, a subsequent tryptic on chip digestion step allows the identification of the proteins deposited on the sensor chip surface via MALDI-ToF mass spectrometry. Prominent blood plasma proteins, i.e., human serum albumin (HSA), fibrinogen (FG) and fibronectin (FN), were used. Chemically well defined sensor surfaces were prepared, among others, via self-assembled monolayer (SAM) technology. In cases where protein adsorption was observed by QCM-D, the adsorbed proteins were clearly detected and identified using MALDI-ToF/MS for both single-protein solutions of HSA, FG and FN as well as for protein mixtures. However, for equimolar protein mixtures on TiO2 surfaces, only signals attributed to FG and FN were observed in the mass spectra. No signals indicating the presence of HSA could be detected. This finding leads to the assumption that only FG and FN attach to the TiO2 sensor surface under the given experimental conditions. 相似文献
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5-(α-D-Glucosyloxymethyl)furfural, a versatile building block from renewable resources, was prepared from isomaltulose–choline chloride melts by acid catalysis. In this solvent-free process, moderate yields were achieved under mild reaction conditions. 相似文献
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Bernhard Valldorf Heiko Fittler Lukas Deweid Aileen Ebenig Stephan Dickgiesser Carolin Sellmann Janine Becker Stefan Zielonka Dr. Martin Empting Dr. Olga Avrutina Prof. Dr. Harald Kolmar 《Angewandte Chemie (International ed. in English)》2016,55(16):5085-5089
Multivalent ligands of death receptors hold particular promise as tumor cell‐specific therapeutic agents because they induce an apoptotic cascade in cancerous cells. Herein, we present a modular approach to generate death receptor 5 (DR5) binding constructs comprising multiple copies of DR5 targeting peptide (DR5TP) covalently bound to biomolecular scaffolds of peptidic nature. This strategy allows for efficient oligomerization of synthetic DR5TP‐derived peptides in different spatial orientations using a set of enzyme‐promoted conjugations or recombinant production. Heptameric constructs based on a short (60–75 residues) scaffold of a C‐terminal oligomerization domain of human C4b binding protein showed remarkable proapoptotic activity (EC50=3 nm ) when DR5TP was ligated to its carboxy terminus. Our data support the notion that inter‐ligand distance, relative spatial orientation and copy number of receptor‐binding modules are key prerequisites for receptor activation and cell killing. 相似文献
186.
Recombinant Cyanobacteria for the Asymmetric Reduction of C=C Bonds Fueled by the Biocatalytic Oxidation of Water
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Katharina Köninger Dr. Álvaro Gómez Baraibar Dr. Carolin Mügge Dr. Caroline E. Paul Dr. Frank Hollmann Dr. Marc M. Nowaczyk Prof. Dr. Robert Kourist 《Angewandte Chemie (International ed. in English)》2016,55(18):5582-5585
A recombinant enoate reductase was expressed in cyanobacteria and used for the light‐catalyzed, enantioselective reduction of C=C bonds. The coupling of oxidoreductases to natural photosynthesis allows asymmetric syntheses fueled by the oxidation of water. Bypassing the addition of sacrificial cosubstrates as electron donors significantly improves the atom efficiency and avoids the formation of undesired side products. Crucial factors for product formation are the availability of NADPH and the amount of active enzyme in the cells. The efficiency of the reaction is comparable to typical whole‐cell biotransformations in E. coli. Under optimized conditions, a solution of 100 mg prochiral 2‐methylmaleimide was reduced to optically pure 2‐methylsuccinimide (99 % ee, 80 % yield of isolated product). High product yields and excellent optical purities demonstrate the synthetic usefulness of light‐catalyzed whole‐cell biotransformations using recombinant cyanobacteria. 相似文献
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Hannes Georg Graf Sonja Maria Biebl Linda Müller Christina Breitenstein Carolin Huhn 《Journal of separation science》2022,45(5):1128-1139
Thermodynamic acidity constants and limiting ionic mobilities were determined for polyprotic non-chromophore analytes using capillary electrophoresis with capacitively coupled contactless conductivity detection. It was not necessary to work with buffers of identical ionic strength as ionic strength effects on effective electrophoretic mobilities were corrected by modeling during data evaluation (software AnglerFish). The mobility data from capillary electrophoresis coupled to conductivity detection were determined in the pH range from 1.25 to 12.02 with a high resolution (36 pH steps). With this strategy, thermodynamic acidity constants and limiting ionic mobilities for various acidic herbicides were determined, sometimes for the first time. The model analytes included glyphosate, its metabolites, and its acetylated derivates (aminomethyl phosphonic acid, glyoxylic acid, sarcosine, glycine, N-acetyl glyphosate, N-acetyl aminomethyl phosphonic acid, hydroxymethyl phosphonic acid). The obtained data were used in simulations to optimize separations by capillary electrophoresis. Simulations correlated very well to experimental results. With the new method, the separation of glyphosate from interfering components like phosphate in beer samples was possible. 相似文献
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