The Experts below are selected from a list of 210 Experts worldwide ranked by ideXlab platform
David R. Tyler - One of the best experts on this subject based on the ideXlab platform.
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Radical Cage Effects: The Prediction of Radical Cage Pair Recombination Efficiencies Using Microviscosity Across a Range of Solvent Types
Journal of the American Chemical Society, 2017Co-Authors: Justin T. Barry, Daniel Berg, David R. TylerAbstract:This study reports a method for correlating the radical recombination efficiencies (FcP) of geminate radical cage pairs to the properties of the solvent. Although bulk viscosity (macroviscosity) is typically used to predict or interpret radical recombination efficiencies, the work reported here shows that Microviscosity is a much better parameter. The use of Microviscosity is valid over a range of different solvent system types, including nonpolar, aromatic, polar, and hydrogen bonding solvents. In addition, the relationship of FcP to Microviscosity holds for solvent systems containing mixtures of these solvent types. The microviscosities of the solvent systems were straightforwardly determined by measuring the diffusion coefficient of an appropriate probe by NMR DOSY spectroscopy. By using solvent mixtures, selective solvation was shown to not affect the correlation between FcP and Microviscosity. In addition, neither solvent polarity nor radical rotation affects the correlation between FcP and the Microviscosity.
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Radical Cage Effects: The Prediction of Radical Cage Pair Recombination Efficiencies Using Microviscosity Across a Range of Solvent Types
2017Co-Authors: Justin T. Barry, Daniel J. Berg, David R. TylerAbstract:This study reports a method for correlating the radical recombination efficiencies (FcP) of geminate radical cage pairs to the properties of the solvent. Although bulk viscosity (macroviscosity) is typically used to predict or interpret radical recombination efficiencies, the work reported here shows that Microviscosity is a much better parameter. The use of Microviscosity is valid over a range of different solvent system types, including nonpolar, aromatic, polar, and hydrogen bonding solvents. In addition, the relationship of FcP to Microviscosity holds for solvent systems containing mixtures of these solvent types. The microviscosities of the solvent systems were straightforwardly determined by measuring the diffusion coefficient of an appropriate probe by NMR DOSY spectroscopy. By using solvent mixtures, selective solvation was shown to not affect the correlation between FcP and Microviscosity. In addition, neither solvent polarity nor radical rotation affects the correlation between FcP and the Microviscosity
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radical cage effects comparison of solvent bulk viscosity and Microviscosity in predicting the recombination efficiencies of radical cage pairs
Journal of the American Chemical Society, 2016Co-Authors: Justin T. Barry, Daniel Berg, David R. TylerAbstract:This study reports the results of experiments that probed how solvents affect the recombination efficiency (FcP) of geminate radical cage pairs. The macroviscosity of solvents has traditionally been used to make quantitative predictions about FcP, but experiments reported here show that FcP varies dramatically for solvent systems with identical macroviscosities. Experiments show that FcP correlates with the solvent Microviscosity: five different solvent systems (consisting of a solvent and a structurally similar viscogen) were examined, and FcP was the same for all five solvent systems at any particular Microviscosity. The translational diffusion coefficient of the radicals (measured by DOSY) in the solvent system was used to define the Microviscosity of the solvent system.
Justin T. Barry - One of the best experts on this subject based on the ideXlab platform.
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Radical Cage Effects: The Prediction of Radical Cage Pair Recombination Efficiencies Using Microviscosity Across a Range of Solvent Types
Journal of the American Chemical Society, 2017Co-Authors: Justin T. Barry, Daniel Berg, David R. TylerAbstract:This study reports a method for correlating the radical recombination efficiencies (FcP) of geminate radical cage pairs to the properties of the solvent. Although bulk viscosity (macroviscosity) is typically used to predict or interpret radical recombination efficiencies, the work reported here shows that Microviscosity is a much better parameter. The use of Microviscosity is valid over a range of different solvent system types, including nonpolar, aromatic, polar, and hydrogen bonding solvents. In addition, the relationship of FcP to Microviscosity holds for solvent systems containing mixtures of these solvent types. The microviscosities of the solvent systems were straightforwardly determined by measuring the diffusion coefficient of an appropriate probe by NMR DOSY spectroscopy. By using solvent mixtures, selective solvation was shown to not affect the correlation between FcP and Microviscosity. In addition, neither solvent polarity nor radical rotation affects the correlation between FcP and the Microviscosity.
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radical cage effects comparison of solvent bulk viscosity and Microviscosity in predicting the recombination efficiencies of radical cage pairs
Journal of the American Chemical Society, 2016Co-Authors: Justin T. Barry, Daniel Berg, David R. TylerAbstract:This study reports the results of experiments that probed how solvents affect the recombination efficiency (FcP) of geminate radical cage pairs. The macroviscosity of solvents has traditionally been used to make quantitative predictions about FcP, but experiments reported here show that FcP varies dramatically for solvent systems with identical macroviscosities. Experiments show that FcP correlates with the solvent Microviscosity: five different solvent systems (consisting of a solvent and a structurally similar viscogen) were examined, and FcP was the same for all five solvent systems at any particular Microviscosity. The translational diffusion coefficient of the radicals (measured by DOSY) in the solvent system was used to define the Microviscosity of the solvent system.
Daniel Berg - One of the best experts on this subject based on the ideXlab platform.
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Radical Cage Effects: The Prediction of Radical Cage Pair Recombination Efficiencies Using Microviscosity Across a Range of Solvent Types
Journal of the American Chemical Society, 2017Co-Authors: Justin T. Barry, Daniel Berg, David R. TylerAbstract:This study reports a method for correlating the radical recombination efficiencies (FcP) of geminate radical cage pairs to the properties of the solvent. Although bulk viscosity (macroviscosity) is typically used to predict or interpret radical recombination efficiencies, the work reported here shows that Microviscosity is a much better parameter. The use of Microviscosity is valid over a range of different solvent system types, including nonpolar, aromatic, polar, and hydrogen bonding solvents. In addition, the relationship of FcP to Microviscosity holds for solvent systems containing mixtures of these solvent types. The microviscosities of the solvent systems were straightforwardly determined by measuring the diffusion coefficient of an appropriate probe by NMR DOSY spectroscopy. By using solvent mixtures, selective solvation was shown to not affect the correlation between FcP and Microviscosity. In addition, neither solvent polarity nor radical rotation affects the correlation between FcP and the Microviscosity.
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radical cage effects comparison of solvent bulk viscosity and Microviscosity in predicting the recombination efficiencies of radical cage pairs
Journal of the American Chemical Society, 2016Co-Authors: Justin T. Barry, Daniel Berg, David R. TylerAbstract:This study reports the results of experiments that probed how solvents affect the recombination efficiency (FcP) of geminate radical cage pairs. The macroviscosity of solvents has traditionally been used to make quantitative predictions about FcP, but experiments reported here show that FcP varies dramatically for solvent systems with identical macroviscosities. Experiments show that FcP correlates with the solvent Microviscosity: five different solvent systems (consisting of a solvent and a structurally similar viscogen) were examined, and FcP was the same for all five solvent systems at any particular Microviscosity. The translational diffusion coefficient of the radicals (measured by DOSY) in the solvent system was used to define the Microviscosity of the solvent system.
Hai-ming Guo - One of the best experts on this subject based on the ideXlab platform.
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Nucleoside-Based Ultrasensitive Fluorescent Probe for the Dual-Mode Imaging of Microviscosity in Living Cells.
Analytical chemistry, 2016Co-Authors: Yan-yan Zhang, Hua Zhang, Xiaopeng Xuan, Ming-sheng Xie, Shuang Xia, Hai-ming GuoAbstract:Microviscosity changes of living cells have a far-reaching influence on diffusion and movement capacity of RNA and, more seriously, could modify RNA functions in living cells. Fluorescent rotor, whose fluorescence responds to different environmental viscosities, holds great potential for the imaging of viscosity in biosystem. Although many fluorescent rotors have been reported for viscosity, the fluorogenic rotor with ultrasensitivity for the determination of Microviscosity (
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nucleoside based ultrasensitive fluorescent probe for the dual mode imaging of Microviscosity in living cells
Analytical Chemistry, 2016Co-Authors: Yan-yan Zhang, Hua Zhang, Xiaopeng Xuan, Ming-sheng Xie, Shuang Xia, Hai-ming GuoAbstract:Microviscosity changes of living cells have a far-reaching influence on diffusion and movement capacity of RNA and, more seriously, could modify RNA functions in living cells. Fluorescent rotor, whose fluorescence responds to different environmental viscosities, holds great potential for the imaging of viscosity in biosystem. Although many fluorescent rotors have been reported for viscosity, the fluorogenic rotor with ultrasensitivity for the determination of Microviscosity (<10 cP) was rarely reported. Herein, we report a nucleoside-based two-photon fluorescent rotor (dABp-3) that can selectively and ultrasensitively image Microviscosity in RNA region of living cells for the first time. 2′-Deoxyadenosine is selected as an electron donor to permit energy transfer via the acetylenic bond to acceptor, a typical boron dipyrromethene moiety. Another highlight, dABp-3 is based on 2′-deoxyadenosine, which result in its recognition capacity for RNA. dABp-3 with ultrasensitivity provides a varied linear response ...
Alain Seret - One of the best experts on this subject based on the ideXlab platform.
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Investigation of SDS, DTAB and CTAB micelle microviscosities by electron spin resonance
Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2006Co-Authors: Mohamed Ali Bahri, Maryse Hoebeke, Angeliki Grammenos, L. Delanaye, Nicolas Vandewalle, Alain SeretAbstract:Electron spin resonance spectroscopy (ESR) of the nitroxide labelled fatty acid probes (5-, 16-doxyl stearic acid) was used to monitor the micelle Microviscosity of three surfactants at various concentrations in aqueous solution: sodium dodecyl sulphate (SDS), dodecyltrimethylammonium bromide (DTAB) and cetyltrimethylammonium bromide (CTAB). At low surfactant concentration, there is no micelle, the ESR probe is dissolved in water/surfactant homogeneous phase and gives his Microviscosity. At higher surfactant concentration, an abrupt increase in Microviscosity indicates the apparition of micelles and, the solubilization of the probes in micelles. The Microviscosity of the three surfactants, in a large surfactant range, was obtained as well as the critical micelle concentration (CMC). The Microviscosity increased slightly with the increase in surfactant concentration. Phosphate buffer lowered the CMC value and generally increased the Microviscosity.
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Quantification of lipid bilayer effective Microviscosity and fluidity effect induced by propofol
Biophysical chemistry, 2004Co-Authors: Mohamed Ali Bahri, Alain Seret, Belinda Heyne, Pol Hans, Ange Mouithys-mickalad, Maryse HoebekeAbstract:Abstract Electron spin resonance (ESR) spectroscopy with nitroxide spin probes was used as a method to probe the liposome microenvironments. The effective microviscosities have been determined from the calibration of the ESR spectra of the probes in solvent mixtures of known viscosities. In the first time, by measuring ESR order parameter ( S ) and correlation time ( τ c ) of stearic spin probes, we have been able to quantify the value of effective Microviscosity at different depths inside the liposome membrane. At room temperature, local microviscosities measured in dimyristoyl- l -α phosphatidylcholine (DMPC) liposome membrane at the different depths of 7.8, 16.95, and 27.7 A were 222.53, 64.09, and 62.56 cP, respectively. In the gel state (10 °C), those Microviscosity values increased to 472.56, 370.61, and 243.37 cP. In a second time, we have applied this technique to determine the modifications in membrane Microviscosity induced by 2,6-diisopropyl phenol (propofol; PPF), an anaesthetic agent extensively used in clinical practice. Propofol is characterized by a unique phenolic structure, absent in the other conventional anaesthetics. Indeed, given its lipophilic property, propofol is presumed to penetrate into and interact with membrane lipids and hence to induce changes in membrane fluidity. Incorporation of propofol into dimyristoyl- l -α phosphatidylcholine liposomes above the phase-transition temperature (23.9 °C) did not change Microviscosity. At 10 °C, an increase of propofol concentration from 0 to 1.0×10 −2 M for a constant lipid concentration mainly induced a decrease in Microviscosity. This fluidity effect of propofol has been qualitatively confirmed using merocyanine 540 (MC540) as lipid packing probe. Above 10 −2 M propofol, no further decrease in Microviscosity was observed, and the Microviscosity at the studied depths (7.8, 16.95, and 27.7 A) amounted 260.21, 123.87, and 102.27 cP, respectively. The concentration 10 −2 M was identified as the saturation limit of propofol in dimyristoyl- l -α phosphatidylcholine liposomes.