排序方式: 共有23条查询结果,搜索用时 31 毫秒
1.
C. Chr. Schu¨ler A. Stuck N. Beck H. Keser U. Ta¨ck 《Journal of Materials Science: Materials in Electronics》2000,11(5):389-396
Bonding between silver and ceramics like Al2O3, ZrO2, MgO, AlN, sapphire or quartz glass is obtained by a liquid phase bonding process based on the pseudo-binary eutectic between Ag and CuO (at 1 mol %). It melts 15 K below the melting point of pure Ag in air. Excellent wetting between the eutectic liquid and the ceramic surfaces gives mechanically strong, reliable bonds. The bonding mechanism is similar to the well known direct copper bonding (DCB)-process. Our new process is simple and works at 1219±2 K in plain air. It therefore has the potential of massive cost reductions compared to the more complicated DCB-process. 相似文献
2.
A three dimensional structural model of oligopeptidase B (OpB) was constructed by homology modeling. High resolution X-ray structure of prolyl oligopeptidase (PEP), the only protein with sequential and functional homology was used as a template. Initial models of OpB were built by the MODELLER and were analysed by the PROCHECK programs. The best quality model was chosen for further refinement by two different techniques--either constrained molecular dynamics simulations or simulated annealing calculations starting from 500 K. The overall quality of each of the refined models was evaluated and the simulated annealing procedure found to be more effective. The refined model was analysed by different protein analysis programs including PROCHECK for the evaluation of the Ramachandran plot quality, PROSA for testing interaction energies and WHATIF for the calculation of packing quality. This structure was found to be satisfactory and also stable at room temperature as demonstrated by a 300 ps long unconstrained molecular dynamics simulation. Calculation of molecular electrostatic potentials revealed that the binding site of OpB is more negative than that of PEP, in accordance with the experimentally observed selectivity of OpB towards proteolysis at dibasic sites. A recently developed Monte Carlo docking method was used provide a structural rationale for the affinity differences measured between Z-Arg and Z-Arg-Arg substrates. 相似文献
3.
Tiazofurin, an important inhibitor of inosine 5'-monophosphate dehydrogenase, has been argued to possess a restricted glycosylic bond due to an energetically favorable intramolecular (1-4) electrostatic interaction between the partial positive sulfur and the negative oxygen of the ribose. This rigidity has been appointed as a plausible cause that leads to activity in the sulfur containing compounds as opposed to the inactive oxazofurin-like analogues (i.e. S is replaced by an oxygen) that lack this favorable interaction. We reinvestigated this notion by using computational methods to report that although the above interaction (or its lack) is likely to contribute to the low-energy conformation of these classes of molecules, the flexibility of the glycosylic bond is ultimately determined by steric interaction of the heteroatoms with the C2'-H and O4' of the ribose. Application of this theory in the design of new analogues is presented as well. 相似文献
4.
European Journal of Wood and Wood Products - Das Spektrum der Anforderungen an die Eigenschaften von Spanplatten hat sich im Laufe des letzten Jahrzehntes erweitert. Neben den ursprünglich im... 相似文献
5.
6.
7.
Moira Rachman Andrea Scarpino Dr. Dávid Bajusz Gyula Pálfy István Vida Prof. András Perczel Prof. Xavier Barril Prof. György M. Keserű 《ChemMedChem》2019,14(10):1011-1021
Thanks to recent guidelines, the design of safe and effective covalent drugs has gained significant interest. Other than targeting non-conserved nucleophilic residues, optimizing the noncovalent binding framework is important to improve potency and selectivity of covalent binders toward the desired target. Significant efforts have been made in extending the computational toolkits to include a covalent mechanism of protein targeting, like in the development of covalent docking methods for binding mode prediction. To highlight the value of the noncovalent complex in the covalent binding process, here we describe a new protocol using tethered and constrained docking in combination with Dynamic Undocking (DUck) as a tool to privilege strong protein binders for the identification of novel covalent inhibitors. At the end of the protocol, dedicated covalent docking methods were used to rank and select the virtual hits based on the predicted binding mode. By validating the method on JAK3 and KRas, we demonstrate how this fast iterative protocol can be applied to explore a wide chemical space and identify potent targeted covalent inhibitors. 相似文献
8.
The crystal structure, thermal, dielectrical, alternating current conductivity and microstructure properties of lithium calcium phosphate ceramics synthesized by the sol–gel method were investigated. The average crystallite size, crystallinity, activation energy and enthalpy of crystallization of Ca10Li(PO4)7 ceramics were determined. The X-ray diffraction (XRD) results indicated that the apatitic structure belonging to HAp was transformed fully to Ca10Li(PO4)7 phase with the addition of Li. The Avrami exponents of the samples suggest that the crystallization mechanism is based on the surface nucleation and one-dimensional growth. It was found that the alternating current conductivity mechanism of the ceramics is controlled by the hopping motion involving a translational motion with a sudden hopping. The dielectric constant of the samples shows a small increase with increasing amount of Li. 相似文献
9.
László Petri Dr. Péter Ábrányi-Balogh Dr. Imre Tímea Dr. Gyula Pálfy Prof. Dr. András Perczel Dr. Damijan Knez Dr. Martina Hrast Dr. Martina Gobec Dr. Izidor Sosič Dr. Kinga Nyíri Prof. Dr. Beáta G. Vértessy Niklas Jänsch Charlotte Desczyk Prof. Dr. Franz-Josef Meyer-Almes Iza Ogris Dr. Simona Golič Grdadolnik Luca Giacinto Iacovino Prof. Dr. Claudia Binda Prof. Dr. Stanislav Gobec Prof. Dr. György M. Keserű 《Chembiochem : a European journal of chemical biology》2021,22(4):743-753
Targeted covalent inhibition and the use of irreversible chemical probes are important strategies in chemical biology and drug discovery. To date, the availability and reactivity of cysteine residues amenable for covalent targeting have been evaluated by proteomic and computational tools. Herein, we present a toolbox of fragments containing a 3,5-bis(trifluoromethyl)phenyl core that was equipped with chemically diverse electrophilic warheads showing a range of reactivities. We characterized the library members for their reactivity, aqueous stability and specificity for nucleophilic amino acids. By screening this library against a set of enzymes amenable for covalent inhibition, we showed that this approach experimentally characterized the accessibility and reactivity of targeted cysteines. Interesting covalent fragment hits were obtained for all investigated cysteine-containing enzymes. 相似文献
10.
Omer Kaygili Serhat Keser Sergey V. Dorozhkin Fahrettin Yakuphanoglu Ahmed A. Al-Ghamdi Sevda Kirbag Duygu Sertkaya Tankut Ates N. Canan Gursoy 《Journal of Inorganic and Organometallic Polymers and Materials》2014,24(6):1001-1008
Ag- and Ba-doped hydroxyapatite (HAp) samples were synthesized by sol–gel method. The crystallite sizes for all the samples were found to vary from 26 to 39 nm. Neither Ag nor Ba did result in dramatic changes in the morphology of all the samples, and the Ca/P molar ratio was varied. The dielectric parameters of the samples were changed with the dopant content. The maximum and minimum values of the dielectric constant were observed for 2.0 %Ba-HAp and 0.5 %Ba-HAp samples. The alternating current conductivity indicates that all the samples exhibit the insulator behavior. The results of the biological tests revealed that Ag-containing samples have an antimicrobial activity, while no antimicrobial activity was detected for both HAp and Ba-doped HAp samples. 相似文献