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Dr. Ana Albu‐Yaron Prof. Dr. Moshe Levy Prof. Dr. Reshef Tenne Dr. Ronit Popovitz‐Biro Marc Weidenbach Dr. Maya Bar‐Sadan Dr. Lothar Houben Dr. Andrey N. Enyashin Prof. Dr. Gotthard Seifert Prof. Dr. Daniel Feuermann Dr. Eugene A. Katz Prof. Dr. Jeffrey M. Gordon 《Angewandte Chemie (International ed. in English)》2011,50(8):1728-1728
696.
Jonathan Thorne Aaron Katz Oisin Tong Yushi Yanagita Yoshiharu Tamaki Keegan Delaney 《国际流体数值方法杂志》2016,82(12):979-996
A novel high‐order finite volume scheme using flux correction methods in conjunction with structured finite differences is extended to low Mach and incompressible flows on strand grids. Flux correction achieves a high order by explicitly canceling low‐order truncation error terms across finite volume faces and is applied in unstructured layers of the strand grid. The layers are then coupled together using a source term containing summation‐by‐parts finite differences in the strand direction. A preconditioner is employed to extend the method to low speed and incompressible flows. We further extend the method to turbulent flows with the Spalart–Allmaras model. Laminar flow test cases indicate improvements in accuracy and convergence using the high‐order preconditioned method, while turbulent body‐of‐revolution flow results show improvements in only some cases, perhaps because of dominant errors arising from the turbulence model itself. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
697.
Evgeny Katz Segiy Minko Jan Halámek Kevin MacVittie Kenneth Yancey 《Analytical and bioanalytical chemistry》2013,405(11):3659-3672
This review outlines advances in designing modified electrodes with switchable properties controlled by various physical and chemical signals. Irradiation of the modified electrode surfaces with various light signals, changing the temperature of the electrolyte solution, application of a magnetic field or electrical potentials, changing the pH of the solutions, and addition of chemical/biochemical substrates were used to change reversibly the electrode activity. The increasing complexity in the signal processing was achieved by integration of the switchable electrode interfaces with biomolecular information processing systems mimicking Boolean logic operations, thus allowing activation and inhibition of electrochemical processes on demand by complex combinations of biochemical signals. The systems reviewed range from simple chemical compositions to complex mixtures modeling biological fluids, where the signal substrates were added at normal physiological and elevated pathological concentrations. The switchable electrode interfaces are considered for future biomedical applications where the electrode properties will be modulated by the biomarker concentrations reflecting physiological conditions. Figure
Modified electrodes were reversibly switched between active and inactive states by various physical and chemical signals. 相似文献
698.
Bridging the Two Worlds: A Universal Interface between Enzymatic and DNA Computing Systems 下载免费PDF全文
Shay Mailloux Dr. Yulia V. Gerasimova Dr. Nataliia Guz Dr. Dmitry M. Kolpashchikov Prof. Evgeny Katz 《Angewandte Chemie (International ed. in English)》2015,54(22):6562-6566
Molecular computing based on enzymes or nucleic acids has attracted a great deal of attention due to the perspectives of controlling living systems in the way we control electronic computers. Enzyme‐based computational systems can respond to a great variety of small molecule inputs. They have the advantage of signal amplification and highly specific recognition. DNA computing systems are most often controlled by oligonucleotide inputs/outputs and are capable of sophisticated computing as well as controlling gene expressions. Here, we developed an interface that enables communication of otherwise incompatible nucleic‐acid and enzyme‐computational systems. The enzymatic system processes small molecules as inputs and produces NADH as an output. The NADH output triggers electrochemical release of an oligonucleotide, which is accepted by a DNA computational system as an input. This interface is universal because the enzymatic and DNA computing systems are independent of each other in composition and complexity. 相似文献
699.
Michael J. Katz Su-Young Moon Joseph E. Mondloch M. Hassan Beyzavi Casey J. Stephenson Joseph T. Hupp Omar K. Farha 《Chemical science》2015,6(4):2286-2291
The hydrolysis of nerve agents is of primary concern due to the severe toxicity of these agents. Using a MOF-based catalyst (UiO-66), we have previously demonstrated that the hydrolysis can occur with relatively fast half-lives of 50 minutes. However, these rates are still prohibitively slow to be efficiently utilized for some practical applications (e.g., decontamination wipes used to clean exposed clothing/skin/vehicles). We thus turned our attention to derivatives of UiO-66 in order to probe the importance of functional groups on the hydrolysis rate. Three UiO-66 derivatives were explored; UiO-66-NO2 and UiO-66-(OH)2 showed little to no change in hydrolysis rate. However, UiO-66-NH2 showed a 20 fold increase in hydrolysis rate over the parent UiO-66 MOF. Half-lives of 1 minute were observed with this MOF. In order to probe the role of the amino moiety, we turned our attention to UiO-67, UiO-67-NMe2 and UiO-67-NH2. In these MOFs, the amino moiety is in close proximity to the zirconium node. We observed that UiO-67-NH2 is a faster catalyst than UiO-67 and UiO-67-NMe2. We conclude that the role of the amino moiety is to act as a proton-transfer agent during the catalytic cycle and not to hydrogen bond or to form a phosphorane intermediate. 相似文献
700.
Divergent Mechanistic Routes for the Formation of gem‐Dimethyl Groups in the Biosynthesis of Complex Polyketides 下载免费PDF全文
Sean Poust Dr. Ryan M. Phelan Dr. Kai Deng Dr. Leonard Katz Dr. Christopher J. Petzold Prof. Dr. Jay D. Keasling 《Angewandte Chemie (International ed. in English)》2015,54(8):2370-2373
The gem‐dimethyl groups in polyketide‐derived natural products add steric bulk and, accordingly, lend increased stability to medicinal compounds, however, our ability to rationally incorporate this functional group in modified natural products is limited. In order to characterize the mechanism of gem‐dimethyl group formation, with a goal toward engineering of novel compounds containing this moiety, the gem‐dimethyl group producing polyketide synthase (PKS) modules of yersiniabactin and epothilone were characterized using mass spectrometry. The work demonstrated, contrary to the canonical understanding of reaction order in PKSs, that methylation can precede condensation in gem‐dimethyl group producing PKS modules. Experiments showed that both PKSs are able to use dimethylmalonyl acyl carrier protein (ACP) as an extender unit. Interestingly, for epothilone module 8, use of dimethylmalonyl‐ACP appeared to be the sole route to form a gem‐dimethylated product, while the yersiniabactin PKS could methylate before or after ketosynthase condensation. 相似文献