The Experts below are selected from a list of 273 Experts worldwide ranked by ideXlab platform
M.a. Arthur - One of the best experts on this subject based on the ideXlab platform.
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Cretaceous shallow drilling, U.S. Western Interior: Core research. Final technical report
1998Co-Authors: M.a. ArthurAbstract:The primary objective of the project is to construct a subsurface transect of Cretaceous strata that were deposited in the Kansas-Colorado-Utah corridor, going from marine sequences that contain organic-carbon-rich hydrocarbon source rocks in Kansas and eastern Colorado to nearshore coal-bearing units in western Colorado and Utah. The drilling transect will provide continuous, unweathered samples for inorganic, organic, and isotopic geochemical studies and mineralogical investigations to determine the characteristics of hydrocarbon source rocks. This transect also will provide information on the extent of thermal maturation and migration of hydrocarbons in organic-carbon-rich strata along a burial gradient. In addition, the eastern Colorado hole will provide characteristics of an important fractured reservoir (the Pierre Shale) in the Florence oil field, the oldest continuously producing field in the United States (>100 years; 600 wells; >14 Mbbls).
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Cretaceous shallow drilling, US Western Interior: Core research
1993Co-Authors: M.a. ArthurAbstract:This project is a continuing multidisciplinary study of middle to Upper Cretaceous marine carbonate and clastic rocks in the Utah-Colorado-Kansas corridor of the old Cretaceous seaway that extended from the Gulf Coast to the Arctic during maximum Cretaceous transgressions. It is collaborative between in the US Geological Survey (W.E. Dean, P.I.) and University researchers led by The Pennsylvania State University(M.A. Arthur, P.I.) and funded by DOE and the USGS, in part. Research focusses on the Greenhom, Niobrara and lower Pierre Shale units and their equivalents, combining biostratigraphic/paleoecologic studies, inorganic, organic and stable isotopic geochemical studies, mineralogical investigations and high-resolution geophysical logging. This research requires unweathered samples and continuous smooth exposures'' in the form of Cores from at least 4 relatively shallow reference holes (i.e. < 1000m) in transect from east to west across the basin. The major initial effort was recovery in Year 1 of the project of continuous Cores from each site in the transect. This drilling provided samples and logs of strata ranging from pelagic sequences that contain organic-carbon-rich marine source rocks to nearshore coal-bearing units. This transect also will provide information on the extent of thermal maturation and migration of hydrocarbons in organic-carbon-rich strata along a burialmore » gradient.« less
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Cretaceous shallow drilling, US Western Interior: Core research. Technical progress report
1993Co-Authors: M.a. ArthurAbstract:This project is a continuing multidisciplinary study of middle to Upper Cretaceous marine carbonate and clastic rocks in the Utah-Colorado-Kansas corridor of the old Cretaceous seaway that extended from the Gulf Coast to the Arctic during maximum Cretaceous transgressions. It is collaborative between in the US Geological Survey (W.E. Dean, P.I.) and University researchers led by The Pennsylvania State University(M.A. Arthur, P.I.) and funded by DOE and the USGS, in part. Research focusses on the Greenhom, Niobrara and lower Pierre Shale units and their equivalents, combining biostratigraphic/paleoecologic studies, inorganic, organic and stable isotopic geochemical studies, mineralogical investigations and high-resolution geophysical logging. This research requires unweathered samples and continuous smooth ``exposures`` in the form of Cores from at least 4 relatively shallow reference holes (i.e. < 1000m) in transect from east to west across the basin. The major initial effort was recovery in Year 1 of the project of continuous Cores from each site in the transect. This drilling provided samples and logs of strata ranging from pelagic sequences that contain organic-carbon-rich marine source rocks to nearshore coal-bearing units. This transect also will provide information on the extent of thermal maturation and migration of hydrocarbons in organic-carbon-rich strata along a burialmore » gradient.« less
Shayan Ahmed - One of the best experts on this subject based on the ideXlab platform.
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conception of nanosized hybrid liposome poloxamer particles to thicken the Interior Core of liposomes and delay hydrophilic drug delivery
International Journal of Pharmaceutics, 2019Co-Authors: Shayan Ahmed, Yohann Corvis, Rabah Gahoual, Arlen EuanAbstract:Abstract Liposomes are nanocarriers composed of phospholipids, especially designed to potentially carry drugs. However, liposomes suffer in terms of leakage of small hydrophilic drugs. To control the release, a system with lipid shell and polymeric viscous Core, namely Hybrid liposome/polymer inside (HLP in ), has been designed. For this purpose, we setup a syringe pump apparatus equipped with homemade tubing system. HLPin formulation consisting of poloxamer (5% w/v) was found to be optimal when produced at injection rates of 5 mL.min -1 . Then, we tend to characterize the HLP in with DLS, TEM, TRPS, thermal analysis and densitometry in comparison with a polymer added after formation of the liposomes. The optimal formulation was evaluated for its stability and cytotoxicity. The selected conditions and composition resulted in nanocarriers which are highly reproducible with mono-disperse size distribution with an average size of 206 ± 4.8 nm and a polydispersity index of 0.15 ± 0.015. Densitometry and thermal analysis results confirmed the formation of HLP in . Interestingly, HLP in were stable over 2 months, produced no cytotoxicity and exhibited slow release of rhodamine and Doxorubicin in comparison to liposome formulation. Our homemade tubing system coupled with syringe pump apparatus achieved reproducible, precisely controlled production for the HLPin formulation which can be scale up.
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Conception of nanosized hybrid liposome/poloxamer particles to thicken the Interior Core of liposomes and delay hydrophilic drug delivery.
International Journal of Pharmaceutics, 2019Co-Authors: Shayan Ahmed, Yohann Corvis, Rabah Gahoual, Arlen Euan, René Lai-kuen, Brice Martin Couillaud, Johanne Seguin, Khair Alhareth, Nathalie MignetAbstract:Abstract Liposomes are nanocarriers composed of phospholipids, especially designed to potentially carry drugs. However, liposomes suffer in terms of leakage of small hydrophilic drugs. To control the release, a system with lipid shell and polymeric viscous Core, namely Hybrid liposome/polymer inside (HLP in ), has been designed. For this purpose, we setup a syringe pump apparatus equipped with homemade tubing system. HLPin formulation consisting of poloxamer (5% w/v) was found to be optimal when produced at injection rates of 5 mL.min -1 . Then, we tend to characterize the HLP in with DLS, TEM, TRPS, thermal analysis and densitometry in comparison with a polymer added after formation of the liposomes. The optimal formulation was evaluated for its stability and cytotoxicity. The selected conditions and composition resulted in nanocarriers which are highly reproducible with mono-disperse size distribution with an average size of 206 ± 4.8 nm and a polydispersity index of 0.15 ± 0.015. Densitometry and thermal analysis results confirmed the formation of HLP in . Interestingly, HLP in were stable over 2 months, produced no cytotoxicity and exhibited slow release of rhodamine and Doxorubicin in comparison to liposome formulation. Our homemade tubing system coupled with syringe pump apparatus achieved reproducible, precisely controlled production for the HLPin formulation which can be scale up.
Friedhelm Schroeder - One of the best experts on this subject based on the ideXlab platform.
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Structure and polarity of mouse brain synaptic plasma membrane: effects of ethanol in vitro and in vivo.
Biochemistry, 1995Co-Authors: Scott M. Colles, W.g. Wood, Sean C. Myers-payne, Urule Igbavboa, Nicolai A. Avdulov, Joseph J, Friedhelm SchroederAbstract:: Structural and dielectric alteration by ethanol in vitro and chronic ethanol consumption were examined in synaptic plasma membranes (SPM) using diphenylhexatriene and charged diphenylhexatriene derivatives. These fluorophores, in combination with multifrequency phase and modulation fluorometry, allowed the examination of the surface and Interior Core of SPM. Limiting anisotropy and rotational relaxation time demonstrated that the synaptosomal plasma membrane surface domain was more rigid than the Interior Core domain. Ethanol in vitro fluidized the Interior Core and surface domains in SPM of the control, but not chronic ethanol-treated mice. Although the latter membranes were more rigid than control membranes, the intrinsic rigidity of the Interior Core of the synaptosomal plasma membrane did not strictly correlate with effects of ethanol in vitro. SPM of irradiated membranes were more rigid, but ethanol fluidized those membranes. Diphenylhexatriene lifetime and photoreactivity were sensitive to the range of dielectric constants in the SPM Interior Core. Ethanol in vitro increased both the surface and Interior Core range of dielectric constants of SPM from control but not chronic ethanol-treated animals. Thus, ethanol in vitro altered not only the fluidity but also the range of dielectric constants in both the surface and Interior Core domains in SPM of control but not chronic ethanol-treated mice.
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Synaptic Plasma Membrane Structure and Polarity of Long-Sleep and Short-Sleep Mice
Archives of Biochemistry and Biophysics, 1994Co-Authors: Friedhelm Schroeder, Scott M. Colles, G.p. Kreishman, Clayton E. Heyliger, W.g. WoodAbstract:Abstract Membrane dielectric as a primary basis for effects of ethanol was examined in synaptic plasma membranes (SPM) of genetically selected ethanol-sensitive long-sleep (LS) and ethanol-resistant short-sleep (SS) mice. Multifrequency phase and modulation fluorometry of diphenylhexatriene (DPH) was used to resolve structural and dielectric differences in the membrane Interior Core. Fluorescence spectral peak ratios, fluorescence lifetime analysis, and initial rates of photoreaction of DPH in SPM provided sensitive measures of SPM Interior Core dielectric properties. The membrane microenvironment sensed by DPH was more polar in SPM from SS mice than in SPM from LS mice. Physiological concentrations of ethanol in vitro (25-75 mM) increased the SPM Interior Core dielectric and potentiated photoreaction of DPH with other membrane components of SPM from LS, but not SS, mice. These effects of ethanol in vitro were maximal by 75 mM ethanol and/or exacerbated at higher ethanol. In addition, ethanol in vitro increased the fraction of DPH associated with photoreaction products with lipids from SPM of ethanol-sensitive LS mice. The data were consistent with ethanol in vitro increasing the polar molecules (ethanol and/or water) of SPM from LS but not SS mice. It is suggested that ethanol alters the polarity and increases reactivity of the Interior Core lipid-protein interface.
W.g. Wood - One of the best experts on this subject based on the ideXlab platform.
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Structure and polarity of mouse brain synaptic plasma membrane: effects of ethanol in vitro and in vivo.
Biochemistry, 1995Co-Authors: Scott M. Colles, W.g. Wood, Sean C. Myers-payne, Urule Igbavboa, Nicolai A. Avdulov, Joseph J, Friedhelm SchroederAbstract:: Structural and dielectric alteration by ethanol in vitro and chronic ethanol consumption were examined in synaptic plasma membranes (SPM) using diphenylhexatriene and charged diphenylhexatriene derivatives. These fluorophores, in combination with multifrequency phase and modulation fluorometry, allowed the examination of the surface and Interior Core of SPM. Limiting anisotropy and rotational relaxation time demonstrated that the synaptosomal plasma membrane surface domain was more rigid than the Interior Core domain. Ethanol in vitro fluidized the Interior Core and surface domains in SPM of the control, but not chronic ethanol-treated mice. Although the latter membranes were more rigid than control membranes, the intrinsic rigidity of the Interior Core of the synaptosomal plasma membrane did not strictly correlate with effects of ethanol in vitro. SPM of irradiated membranes were more rigid, but ethanol fluidized those membranes. Diphenylhexatriene lifetime and photoreactivity were sensitive to the range of dielectric constants in the SPM Interior Core. Ethanol in vitro increased both the surface and Interior Core range of dielectric constants of SPM from control but not chronic ethanol-treated animals. Thus, ethanol in vitro altered not only the fluidity but also the range of dielectric constants in both the surface and Interior Core domains in SPM of control but not chronic ethanol-treated mice.
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Synaptic Plasma Membrane Structure and Polarity of Long-Sleep and Short-Sleep Mice
Archives of Biochemistry and Biophysics, 1994Co-Authors: Friedhelm Schroeder, Scott M. Colles, G.p. Kreishman, Clayton E. Heyliger, W.g. WoodAbstract:Abstract Membrane dielectric as a primary basis for effects of ethanol was examined in synaptic plasma membranes (SPM) of genetically selected ethanol-sensitive long-sleep (LS) and ethanol-resistant short-sleep (SS) mice. Multifrequency phase and modulation fluorometry of diphenylhexatriene (DPH) was used to resolve structural and dielectric differences in the membrane Interior Core. Fluorescence spectral peak ratios, fluorescence lifetime analysis, and initial rates of photoreaction of DPH in SPM provided sensitive measures of SPM Interior Core dielectric properties. The membrane microenvironment sensed by DPH was more polar in SPM from SS mice than in SPM from LS mice. Physiological concentrations of ethanol in vitro (25-75 mM) increased the SPM Interior Core dielectric and potentiated photoreaction of DPH with other membrane components of SPM from LS, but not SS, mice. These effects of ethanol in vitro were maximal by 75 mM ethanol and/or exacerbated at higher ethanol. In addition, ethanol in vitro increased the fraction of DPH associated with photoreaction products with lipids from SPM of ethanol-sensitive LS mice. The data were consistent with ethanol in vitro increasing the polar molecules (ethanol and/or water) of SPM from LS but not SS mice. It is suggested that ethanol alters the polarity and increases reactivity of the Interior Core lipid-protein interface.
Rabah Gahoual - One of the best experts on this subject based on the ideXlab platform.
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conception of nanosized hybrid liposome poloxamer particles to thicken the Interior Core of liposomes and delay hydrophilic drug delivery
International Journal of Pharmaceutics, 2019Co-Authors: Shayan Ahmed, Yohann Corvis, Rabah Gahoual, Arlen EuanAbstract:Abstract Liposomes are nanocarriers composed of phospholipids, especially designed to potentially carry drugs. However, liposomes suffer in terms of leakage of small hydrophilic drugs. To control the release, a system with lipid shell and polymeric viscous Core, namely Hybrid liposome/polymer inside (HLP in ), has been designed. For this purpose, we setup a syringe pump apparatus equipped with homemade tubing system. HLPin formulation consisting of poloxamer (5% w/v) was found to be optimal when produced at injection rates of 5 mL.min -1 . Then, we tend to characterize the HLP in with DLS, TEM, TRPS, thermal analysis and densitometry in comparison with a polymer added after formation of the liposomes. The optimal formulation was evaluated for its stability and cytotoxicity. The selected conditions and composition resulted in nanocarriers which are highly reproducible with mono-disperse size distribution with an average size of 206 ± 4.8 nm and a polydispersity index of 0.15 ± 0.015. Densitometry and thermal analysis results confirmed the formation of HLP in . Interestingly, HLP in were stable over 2 months, produced no cytotoxicity and exhibited slow release of rhodamine and Doxorubicin in comparison to liposome formulation. Our homemade tubing system coupled with syringe pump apparatus achieved reproducible, precisely controlled production for the HLPin formulation which can be scale up.
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Conception of nanosized hybrid liposome/poloxamer particles to thicken the Interior Core of liposomes and delay hydrophilic drug delivery.
International Journal of Pharmaceutics, 2019Co-Authors: Shayan Ahmed, Yohann Corvis, Rabah Gahoual, Arlen Euan, René Lai-kuen, Brice Martin Couillaud, Johanne Seguin, Khair Alhareth, Nathalie MignetAbstract:Abstract Liposomes are nanocarriers composed of phospholipids, especially designed to potentially carry drugs. However, liposomes suffer in terms of leakage of small hydrophilic drugs. To control the release, a system with lipid shell and polymeric viscous Core, namely Hybrid liposome/polymer inside (HLP in ), has been designed. For this purpose, we setup a syringe pump apparatus equipped with homemade tubing system. HLPin formulation consisting of poloxamer (5% w/v) was found to be optimal when produced at injection rates of 5 mL.min -1 . Then, we tend to characterize the HLP in with DLS, TEM, TRPS, thermal analysis and densitometry in comparison with a polymer added after formation of the liposomes. The optimal formulation was evaluated for its stability and cytotoxicity. The selected conditions and composition resulted in nanocarriers which are highly reproducible with mono-disperse size distribution with an average size of 206 ± 4.8 nm and a polydispersity index of 0.15 ± 0.015. Densitometry and thermal analysis results confirmed the formation of HLP in . Interestingly, HLP in were stable over 2 months, produced no cytotoxicity and exhibited slow release of rhodamine and Doxorubicin in comparison to liposome formulation. Our homemade tubing system coupled with syringe pump apparatus achieved reproducible, precisely controlled production for the HLPin formulation which can be scale up.