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排序方式: 共有627条查询结果,搜索用时 62 毫秒
1.
Gabrielle A. Leith Allison M. Rice Brandon J. Yarbrough Anna A. Berseneva Richard T. Ly Charles N. Buck III Dr. Denis Chusov Amy J. Brandt Prof. Dr. Donna A. Chen Benjamin W. Lamm Prof. Dr. Morgan Stefik Kenneth S. Stephenson Dr. Mark D. Smith Prof. Dr. Aaron K. Vannucci Dr. Perry J. Pellechia Prof. Dr. Sophya Garashchuk Prof. Dr. Natalia B. Shustova 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(15):6056-6062
The effect of donor (D)–acceptor (A) alignment on the materials electronic structure was probed for the first time using novel purely organic porous crystalline materials with covalently bound two- and three-dimensional acceptors. The first studies towards estimation of charge transfer rates as a function of acceptor stacking are in line with the experimentally observed drastic, eight-fold conductivity enhancement. The first evaluation of redox behavior of buckyball- or tetracyanoquinodimethane-integrated crystalline was conducted. In parallel with tailoring the D-A alignment responsible for “static” changes in materials properties, an external stimulus was applied for “dynamic” control of the electronic profiles. Overall, the presented D–A strategic design, with stimuli-controlled electronic behavior, redox activity, and modularity could be used as a blueprint for the development of electroactive and conductive multidimensional and multifunctional crystalline porous materials. 相似文献
2.
Brandon C. Presley Marisol S. Castaneto Barry K. Logan Susan A. Jansen-Varnum 《Biomedical chromatography : BMC》2020,34(9):e4884
FUB-AMB, an indazole carboxamide synthetic cannabinoid recreational drug, was one of the compounds most frequently reported to governmental agencies worldwide between 2016 and 2019. It has been implicated in intoxications and fatalities, posing a risk to public health. In the current study, FUB-AMB was incubated with human liver microsomes (HLM) to assess its metabolic fate and stability and to determine if its major ester hydrolysis metabolite (M1) was present in 12 authentic forensic human blood samples from driving under the influence of drug cases and postmortem investigations using UHPLC–MS/MS. FUB-AMB was rapidly metabolized in HLM, generating M1 that was stable through a 120-min incubation period, a finding that indicates a potential long detection window in human biological samples. M1 was identified in all blood samples, and no parent drug was detected. The authors propose that M1 is a reliable marker for inclusion in laboratory blood screens for FUB-AMB; this metabolite may be pharmacologically active like its precursor FUB-AMB. M1 frequently appears in samples in which the parent drug is undetectable and can point to the causative agent. The results suggest that it is imperative that synthetic cannabinoid laboratory assay panels include metabolites, especially known or potential pharmacologically active metabolites, particularly for compounds with short half-lives. 相似文献
3.
4.
Dr. Timothy A. Barendt Dr. Melissa L. Ball Dr. Qizhi Xu Dr. Boyuan Zhang Dr. Brandon Fowler Ayden Schattman Virginia Cary Ritter Prof. Michael L. Steigerwald Prof. Colin Nuckolls 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(17):3744-3748
This work presents a synergy between organic electronics and supramolecular chemistry, in which a host–guest complex is designed to function as an efficacious electronic material. Specifically, the noncovalent recognition of a fullerene, phenyl-C61-butyric acid methyl ester ( PC61BM ), by an alternating perylene diimide ( P )-bithiophene ( B ) conjugated macrocycle ( PBPB ) results in a greater than five-fold enhancement in electron mobility, relative to the macrocycle alone. Characterization and quantification of the binding of fullerenes by host PBPB is provided alongside evidence for intermolecular electronic communication within the host–guest complexes. 相似文献
5.
Automated solvent system screening for the preparative countercurrent chromatography of pharmaceutical discovery compounds 下载免费PDF全文
James Bradow Frank Riley Laurence Philippe Qi Yan Brandon Schuff Guy H. Harris 《Journal of separation science》2015,38(23):3983-3991
A fully automated countercurrent chromatography system has been constructed to rapidly screen the commonly used heptane/ethyl acetate/methanol/water solvent system series and translate the results to preparative scale separations. The system utilizes “on‐demand” preparation of the heptane/ethyl acetate/methanol/water solvent system upper and lower phases. Elution‐extrusion countercurrent chromatography was combined with non‐dynamic equilibrium injection reducing the screening time for each heptane/ethyl acetate/methanol/water system to 17 min. The result enabled solvent system development to be reduced to under 2 h. The countercurrent chromatography system was interfaced with a mass spectrometer to allow selective detection of target components in crude medicinal chemistry reaction mixtures. Mass‐directed preparative countercurrent chromatography purification was demonstrated for the first time using a synthetic tetrazole epoxide derived from a routine medicinal chemistry support workflow. 相似文献
6.
Grace C. Thaggard Dr. Gabrielle A. Leith Daniil Sosnin Dr. Corey R. Martin Kyoung Chul Park Margaret K. McBride Dr. Jaewoong Lim Brandon J. Yarbrough Buddhima K. P. Maldeni Kankanamalage Gina R. Wilson Austin R. Hill Dr. Mark D. Smith Prof. Dr. Sophya Garashchuk Prof. Dr. Andrew B. Greytak Prof. Dr. Ivan Aprahamian Prof. Dr. Natalia B. Shustova 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2023,135(2):e202211776
Confinement-imposed photophysics was probed for novel stimuli-responsive hydrazone-based compounds demonstrating a conceptual difference in their behavior within 2D versus 3D porous matrices for the first time. The challenges associated with photoswitch isomerization arising from host interactions with photochromic compounds in 2D scaffolds could be overcome in 3D materials. Solution-like photoisomerization rate constants were realized for sterically demanding hydrazone derivatives in the solid state through their coordinative immobilization in 3D scaffolds. According to steady-state and time-resolved photophysical measurements and theoretical modeling, this approach provides access to hydrazone-based materials with fast photoisomerization kinetics in the solid state. Fast isomerization of integrated hydrazone derivatives allows for probing and tailoring resonance energy transfer (ET) processes as a function of excitation wavelength, providing a novel pathway for ET modulation. 相似文献
7.
Brandon Wilfong Muhtar Ahart Stephen A. Gramsch Chris Stock Xiaomin Li H. Luo Russell J. Hemley 《Journal of Raman spectroscopy : JRS》2016,47(2):227-232
The vibrational and structural properties of Pb(Fe0.5Nb0.5)O3 have been investigated using Raman spectroscopy up to 40 GPa at 300 K and from 300 to 415 K at selected pressures. The measurements reveal three phase transitions, at 5.5, 8.7, and 24 GPa at room temperature. The temperature dependences of the spectra indicate transitions at 1.5 GPa, at 335 and 365 K. The results are consistent with the appearance of an intermediate tetragonal P4mm phase between the ferroelectric R3m and paraelectric Pm‐3m phases. A P–T phase diagram is proposed that allows further insight into the magnetoelectric coupling present in this material. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
8.
This paper presents a method for the analytical prediction of sliding motions along discontinuous boundaries in non-smooth
dynamical systems. The methodology is demonstrated through investigation of a periodically forced linear oscillator with dry
friction. The switching conditions for sliding motions in non-smooth dynamical systems are given. The generic mappings for
the friction-induced oscillator are introduced. From the generic mappings, the corresponding criteria for the sliding motions
are presented through the force product conditions. The analytical prediction of the onset and vanishing of the sliding motions
is illustrated. Finally, numerical simulations of sliding motions are carried out to verify the analytical prediction. This
analytical prediction provides an accurate prediction of sliding motions in non-smooth dynamical systems. The switching conditions
developed in this paper are expressed by the total force of the oscillator, and the nonlinearity and linearity of the spring
and viscous damping forces in the oscillator cannot change such switching conditions. Therefore, the achieved force criteria
can be applied to the other dynamical systems with nonlinear friction forces processing a C
0-discontinuity. 相似文献
9.
do Nascimento Marreiro Teixeira Ana Siqueira Siqueira Teixeira Paulo Ronaldo Sousa de Oliveira Farias Emanuel Airton Ferraz e Sousa Brandon Moura Sérvulo Kátia Bonfim de Leite da Silva Durcilene Alves Eiras Carla 《Journal of Solid State Electrochemistry》2020,24(5):1143-1155
Journal of Solid State Electrochemistry - The present work proposes a new electrochemical sulfite biosensor based on babassu mesocarp nanoparticles (BMNPs) immobilized on the surface of a pyrolytic... 相似文献
10.
Kyung Min Lee Brandon M. Lynch Paul Luchette Timothy J. White 《Journal of polymer science. Part A, Polymer chemistry》2014,52(6):876-882
The photomechanical response and photochemistry of a conventional, unsubstituted azobenzene‐functionalized liquid crystalline polymer network (azo‐LCN) is contrasted to that of an analogous material prepared with meta‐fluorinated azobenzene chromophores. The polydomain azo‐LCN materials exhibit nearly identical thermomechanical and optical properties. Photomechanical characterization indicates that the fluorination of the azobenzene chromophore reduces the deflection of cantilevers composed of the materials by 50%, which spectroscopic analysis reveals is due to a reduction in the ability of this material to isomerize and potentially reorient. This work is further confirmation that the underlying photochemistry of azobenzene is a primary contributor to the generation of photomechanical work in these materials. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 876–882 相似文献