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Dr. Giulio Navarra Dr. Pascal Zihlmann Dr. Roman P. Jakob Dr. Katja Stangier Dr. Roland C. Preston Dr. Said Rabbani Dr. Martin Smiesko Bea Wagner Prof. Dr. Timm Maier Prof. Dr. Beat Ernst 《Chembiochem : a European journal of chemical biology》2017,18(6):539-544
Uropathogenic E. coli exploit PapG‐II adhesin for infecting host cells of the kidney; the expression of PapG‐II at the tip of bacterial pili correlates with the onset of pyelonephritis in humans, a potentially life‐threatening condition. It was envisaged that blocking PapG‐II (and thus bacterial adhesion) would provide a viable therapeutic alternative to conventional antibiotic treatment. In our search for potent PapG‐II antagonists, we observed an increase in affinity when tetrasaccharide 1 , the natural ligand of PapG‐II in human kidneys, was elongated to hexasaccharide 2 , even though the additional Siaα(2–3)Gal extension is not in direct contact with the lectin. ITC studies suggest that the increased affinity results from partial desolvation of nonbinding regions of the hexasaccharide; this is ultimately responsible for perturbation of the outer hydration layers. Our results are in agreement with previous observations and suggest a general mechanism for modulating carbohydrate–protein interactions based on nonbinding regions of the ligand. 相似文献
43.
Joachim Lentes Joerg Mandel Ursula Schliessmann Roland Blach Michael Hertwig Timm Kuhlmann 《国际生产研究杂志》2017,55(2):480-491
The rapid growth of the world population, the finiteness of resources on our planet Earth and the ongoing tendency towards urbanisation result in the need to question our actions and economic activities, also for industrial enterprises. A paradigm shift to decouple growth and resource utilisation is needed. By means of ultra-efficiency, factories are targeted, whose positive impact to their surrounding is optimised instead of only minimising negative influences. In the contribution, the concept of ultra-efficient factories and first tools for their implementation are introduced. Therefore, the term ultra-efficient factory is defined based on the state of the art. On this definition, spheres of activity for ultra-efficient factories under consideration of urban surroundings are determined. For the spheres of activity, criteria to assess the according maturity of companies are identified and aggregated into a comprehensive maturity model. The maturity model enables the determination of potentials for advancements of companies. To support the industrial application of the theoretic work, industrial best practices are determined and a visual tool is developed. 相似文献
44.
Karl Ludger Radke Lena Marie Wilms Miriam Frenken Julia Stabinska Marek Knet Benedikt Kamp Thomas Andreas Thiel Timm Joachim Filler Sven Nebelung Gerald Antoch Daniel Benjamin Abrar Hans-Jrg Wittsack Anja Müller-Lutz 《International journal of molecular sciences》2022,23(13)
Based on in silico, in situ, and in vivo studies, this study aims to develop a new method for the quantitative chemical exchange saturation transfer (qCEST) technique considering multi-pool systems. To this end, we extended the state-of-the-art apparent exchange-dependent relaxation (AREX) method with a Lorentzian correction (LAREX). We then validated this new method with in situ and in vivo experiments on human intervertebral discs (IVDs) using the Kendall-Tau correlation coefficient. In the in silico experiments, we observed significant deviations of the AREX method as a function of the underlying exchange rate (kba) and fractional concentration (fb) compared to the ground truth due to the influence of other exchange pools. In comparison to AREX, the LAREX-based Ω-plot approach yielded a substantial improvement. In the subsequent in situ and in vivo experiments on human IVDs, no correlation to the histological reference standard or Pfirrmann classification could be found for the fb (in situ: τ = −0.17 p = 0.51; in vivo: τ = 0.13 p = 0.30) and kba (in situ: τ = 0.042 p = 0.87; in vivo: τ = −0.26 p = 0.04) of Glycosaminoglycan (GAG) with AREX. In contrast, the influence of interfering pools could be corrected by LAREX, and a moderate to strong correlation was observed for the fractional concentration of GAG for both in situ (τ = −0.71 p = 0.005) and in vivo (τ = −0.49 p < 0.001) experiments. The study presented here is the first to introduce a new qCEST method that enables qCEST imaging in systems with multiple proton pools. 相似文献
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Maryam Khalilian Zhaoxia Bi Jonas Johansson Filip Lenrick Olof Hultin Jovana Colvin Rainer Timm Reine Wallenberg Jonas Ohlsson Mats‐Erik Pistol Anders Gustafsson Lars Samuelson 《Small (Weinheim an der Bergstrasse, Germany)》2020,16(30)
III‐nitrides are considered the material of choice for light‐emitting diodes (LEDs) and lasers in the visible to ultraviolet spectral range. The development is hampered by lattice and thermal mismatch between the nitride layers and the growth substrate leading to high dislocation densities. In order to overcome the issue, efforts have gone into selected area growth of nanowires (NWs), using their small footprint in the substrate to grow virtually dislocation‐free material. Their geometry is defined by six tall side‐facets and a pointed tip which limits the design of optoelectronic devices. Growth of dislocation‐free and atomically smooth 3D hexagonal GaN micro‐prisms with a flat, micrometer‐sized top‐surface is presented. These self‐forming structures are suitable for optical devices such as low‐loss optical cavities for high‐efficiency LEDs. The structures are made by annealing GaN NWs with a thick radial shell, reforming them into hexagonal flat‐top prisms with six equivalents either m‐ or s‐facets depending on the initial heights of the top pyramid and m‐facets of the NWs. This shape is kinetically controlled and the reformation can be explained with a phenomenological model based on Wulff construction that have been developed. It is expected that the results will inspire further research into micron‐sized III‐nitride‐based devices. 相似文献
47.
Structural analysis and design of a steel bridge – comparing the new standards with the previous ones. The DIN ‐Fachberichte were adopted in 2003 as new standards for structural analysis and design of bridges. Their application results in changes of loading, design methods and design of bridges compared to the previous regulations. This contribution will illustrate the effects of the new standards on the steel construction of a railway bridge by comparing its structural analysis and design both according to new standards and previous ones. As a result the comparison shows that mainly due to more conservative load distribution in the road bed the trackway needs to be reinforced. 相似文献
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49.
Detre Teschner Ramzi Farra Lide Yao Robert Schlögl Hary Soerijanto Reinhard Schomäcker Timm Schmidt László Szentmiklósi Amol P. Amrute Cecilia Mondelli Javier Pérez-Ramírez Gerard Novell-Leruth Núria López 《Journal of Catalysis》2012,285(1):273-284
Rationally designed RuO2-based Deacon catalysts can contribute to massive energy saving compared to the current electrolysis process in chemically recycling HCl to produce molecular chlorine. Here, we report on our integrated approach between state-of-the-art experiments and calculations. The aim is to understand industrial Deacon catalyst in its realistic surface state and to derive mechanistic insights into this sustainable reaction. We show that the practically relevant RuO2/SnO2 consists of two major RuO2 morphologies, namely 2–4 nm-sized particles and 1–3-ML-thick epitaxial RuO2 films attached to the SnO2 support particles. A large fraction of the small nanoparticles expose {1 1 0} and {1 0 1} facets, whereas the film grows with the same orientations, due to the preferential surface orientation of the rutile-type support. Steady-state Deacon kinetics indicate a medium-to-strong positive effect of the partial pressures of reactants and deep inhibition by both water and chlorine products. Temporal Analysis of Products and in situ Prompt Gamma Activation Analysis strongly suggest a Langmuir–Hinshelwood mechanism and that adsorbed Cl poisons the surface. Under relevant operation conditions, the reactivity is proportional to the coverage of a specific atomic oxygen species. On the extensively chlorinated surface that can be described as surface oxy-chloride, oxygen activation is the rate-determining step. DFT-based micro-kinetic modeling reproduced all experimental observations and additionally suggested that the reaction is structure sensitive. Out of the investigated models, the 2 ML RuO2 film-covered SnO2 gives rise to significantly higher reactivity than the (1 0 1) surface, whereas the 1 ML film seems to be inactive. 相似文献
50.
Timothy P. Hogan Adam Downey Jarrod Short Jonathan D’Angelo Chun-I Wu Eric Quarez John Androulakis Pierre F.P. Poudeu Joseph R. Sootsman Duck-Young Chung Mercouri G. Kanatzidis S.D. Mahanti Edward J. Timm Harold Schock Fei Ren Jason Johnson Eldon D. Case 《Journal of Electronic Materials》2007,36(7):704-710
For thermoelectric applications, the best materials have high electrical conductivity and thermopower and, simultaneously,
low thermal conductivity. Such a combination of properties is usually found in heavily doped semiconductors. Renewed interest
in this topic has followed recent theoretical predictions that significant increases in performance are possible for nanostructured
materials, and this has been experimentally verified. During exploratory synthetic studies of chalcogenide-based bulk thermoelectric
materials it was discovered that several compounds spontaneously formed endotaxially embedded nanostructures. These compounds
have some of the best known properties for bulk thermoelectric materials in the 500–800 K temperature range. Here we report
our continued efforts to better understand the role of the nanostructures while concurrently furthering the development of
these new materials (for example n-type lead–antimony–silver–tellurium, and p-type lead–antimony–silver–tin–tellurium) into thermoelectric power-generation devices. 相似文献