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101.
Visual Displays that Directly Interface and Provide Read‐Outs of Molecular States via Molecular Graphics Processing Units 下载免费PDF全文
Julia E. Poje Tamara Kastratovic Andrew R. Macdonald Ana C. Guillermo Steven E. Troetti Dr. Omar J. Jabado M. Leigh Fanning Prof. Darko Stefanovic Dr. Joanne Macdonald 《Angewandte Chemie (International ed. in English)》2014,53(35):9222-9225
The monitoring of molecular systems usually requires sophisticated technologies to interpret nanoscale events into electronic‐decipherable signals. We demonstrate a new method for obtaining read‐outs of molecular states that uses graphics processing units made from molecular circuits. Because they are made from molecules, the units are able to directly interact with molecular systems. We developed deoxyribozyme‐based graphics processing units able to monitor nucleic acids and output alphanumerical read‐outs via a fluorescent display. Using this design we created a molecular 7‐segment display, a molecular calculator able to add and multiply small numbers, and a molecular automaton able to diagnose Ebola and Marburg virus sequences. These molecular graphics processing units provide insight for the construction of autonomous biosensing devices, and are essential components for the development of molecular computing platforms devoid of electronics. 相似文献
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Peter A. Macdonald Dr. Sumanta Banerjee Dr. Alan R. Kennedy Dr. Alexander van Teijlingen Dr. Stuart D. Robertson Prof. Tell Tuttle Prof. Robert E. Mulvey 《Angewandte Chemie (International ed. in English)》2023,62(27):e202304966
Catalytic reduction of a representative set of imines, both aldimines and ketimines, to amines has been studied using transfer hydrogenation from 1,4-dicyclohexadiene. Unusually, this has been achieved using s-block pre-catalysts, namely 1-metallo-2-tert-butyl-1,2-dihydropyridines, 2-tBuC5H5NM, M(tBuDHP), where M=Li–Cs. Reactions have been monitored in C6D6 and tetrahydrofuran-d8 (THF-d8). A definite trend is observed in catalyst efficiency with the heavier alkali metal tBuDHPs outperforming the lighter congeners. In general, Cs(tBuDHP) is the optimal pre-catalyst with, in the best cases, reactions producing quantitative yields of amines in minutes at room temperature using 5 mol % catalyst. Supporting the experimental study, Density Functional Theory (DFT) calculations have also been carried out which reveal that Cs has a pathway with a significantly lower rate determining step than the Li congener. In the postulated initiation pathways DHP can act as either a base or as a surrogate hydride. 相似文献
104.
The determination of carbon and hydrogen in organometallic compounds is described. Cobalto-cobaltic oxide is used as the catalytic tube filling in a rapid procedure. Compounds containing Na, K. Cu, Be, Mg, Ca. Zn, Cd, Hg, Al, B, Ga, Ti, Pb, Nb. P, As, Bi, Mo. U, Sc, Te, Mn, Fe, Co, Ni were examined; interferences were overcome where necessary and tungstic oxide proved a valuable auxiliary reagent. 相似文献
105.
Özge Pala Dirk J Vriens Jac AM Vennix 《The Journal of the Operational Research Society》2015,66(4):593-601
Escalation of commitment, the tendency of decision makers to keep on investing in losing courses of action, has been shown to be a costly decision bias that affects many areas of decision making. Even though escalation is a widely studied phenomenon, there has been comparatively little research on how to avoid this bias. The present study focuses on de-escalation of commitment and proposes that causal loop diagrams (CLDs) can help to decrease escalating commitment to a failing course of action. By means of an experiment, this study shows that using a CLD decreases escalation tendencies. 相似文献
106.
Hieu T. Nguyen Di Yan Fan Wang Peiting Zheng Young Han Daniel Macdonald 《固体物理学:研究快报》2015,9(4):230-235
We report and explain the photoluminescence spectra emitted from silicon solar cells with heavily‐doped layers at the surface. A micro‐photoluminescence spectroscopy system is employed to investigate the total spectrum emitted from both the heavily‐doped layer and the silicon substrate with micron‐scale spatial resolution. The two regions of the device give rise to separate photoluminescence peaks, due to band‐gap narrowing effects in the highly‐doped layer. Two key parameters, the absorption depth of the excitation wavelength, and the sample temperature, are shown to be critical to reveal the separate signatures from the two regions. Finally, this technique is applied to locally diffused and laser‐doped regions on silicon solar cell pre‐cursors, demonstrating the potential value of this micron‐scale technique in studying and optimizing locally doped regions. (© 2015 WILEY‐VCH Verlag GmbH &Co. KGaA, Weinheim) 相似文献
107.
Dr. Malte Brasholz Dr. James M. Macdonald Dr. Simon Saubern Dr. John H. Ryan Prof. Dr. Andrew B. Holmes 《Chemistry (Weinheim an der Bergstrasse, Germany)》2010,16(37):11471-11480
The total synthesis of the spiropiperidine alkaloid (?)‐perhydrohistrionicotoxin (perhydro‐HTX) 2 has been accomplished on a gram scale by employing both conventional batch chemistry as well as microreactor techniques. (S)‐(?)‐6‐Pentyltetrahydro‐pyran‐2‐one 8 underwent nucleophilic ring opening to afford the alcohol 10 , which was elaborated to the nitrone 13 . Protection of the nitrone as the 1,3‐adduct of styrene and side‐chain extension to the unsaturated nitrile afforded a precursor 17 , which underwent dipolar cycloreversion and 1,3‐dipolar cycloaddition to give the core spirocyclic precursor 18 that was converted into perhydro‐HTX 2 . The principal steps to the spirocycle 18 have successfully been transferred into flow mode by using different types of microreactors and in a telescoped fashion, allowing for a more rapid access to the histrionicotoxins and their analogues by continuous processing. 相似文献
108.
Tony W. J. Cooper Ian B. Campbell Dr. Simon J. F. Macdonald 《Angewandte Chemie (International ed. in English)》2010,49(44):8082-8091
Synthetic organic reactions are a fundamental enabler of small‐molecule drug discovery, and the vast majority of medicinal chemists are initially trained—either at universities or within industry—as synthetic organic chemists. The sheer breadth of synthetic methodology available to the medicinal chemist represents an almost endless source of innovation. But what reactions do medicinal chemists use in drug discovery? And what criteria do they use in selecting synthetic methodology? Why are arrays (small focused libraries) so powerful in the lead‐optimization process? In this Minireview, we suggest some answers to these questions and also describe how we have tried to expand the number of robust reactions available to the medicinal chemist. 相似文献
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Yang J Cyr PW Wang Y Soong R Macdonald PM Chen L Manners I Winnik MA 《Photochemistry and photobiology》2006,82(1):262-267
We describe experiments that determine the quenching kinetics by poly(ferrocenylsilane) (PFS) for platinum octaethylporphine (PtOEP) phosphorescence in toluene solution. The phosphorescence quenching process was interpreted in terms of diffusion-controlled kinetics. Pulsed-gradient spin-echo nuclear magnetic resonance (PGSE NMR) and dynamic light scattering (DLS) were used to characterize the diffusion behavior of PFS and PtOEP in toluene solution. We found that the ferrocene group present in the repeat unit of polymer backbone is a good quencher for PtOEP phosphorescence. Quenching by the polymer involves the entire PFS polymer chain instead of individual ferrocene groups. The intrinsic quenching ability of PFS was found to be higher than that of a model compound, Bu-FS, that contains a single ferrocene group. 相似文献