63 research outputs found
Density Functional and Hartree−Fock Calculations on the Cyclopropane Ring Intermediates Involved in the Zeolite-Catalyzed Skeletal Isomerization of Hydrocarbons and in the Carbon Isotope Scrambling in 2-Propyl Cation
Prevention of benzene-induced myelotoxicity by nonsteroidal anti-inflammatory drugs.
Benzene affects hematopoietic progenitor cells leading to bone marrow depression and genotoxic effects such as micronucleus formation. Progenitor cell proliferation and differentiation are inhibited by prostaglandins produced by macrophages. Administration of benzene to DBA/2 or C57BL/6 mice caused a dose-dependent bone marrow depression and a significant increase in marrow prostaglandin E level and both were prevented by the coadministration of indomethacin and other inhibitors of the cyclooxygenase component of prostaglandin H synthase. Levels of benzene that decreased bone marrow cellularity also caused genotoxic effects measured as increased micronucleated polychromatic erythrocytes in peripheral blood, which was also prevented by the coadministration of indomethacin. These results suggest a possible role for prostaglandin synthase in benzene myelotoxicity; a mechanism by which this might occur is presented
New Experimental Equipment Recreating Geo-Reservoir Conditions in Large, Fractured, Porous Samples to Investigate Coupled Thermal, Hydraulic and Polyaxial Stress Processes
Abstract Use of the subsurface for energy resources (enhanced geothermal systems, conventional and unconventional hydrocarbons), or for storage of waste (CO2, radioactive), requires the prediction of how fluids and the fractured porous rock mass interact. The GREAT cell (Geo-Reservoir Experimental Analogue Technology) is designed to recreate subsurface conditions in the laboratory to a depth of 3.5 km on 200 mm diameter rock samples containing fracture networks, thereby enabling these predictions to be validated. The cell represents an important new development in experimental technology, uniquely creating a truly polyaxial rotatable stress field, facilitating fluid flow through samples, and employing state of the art fibre optic strain sensing, capable of thousands of detailed measurements per hour. The cell’s mechanical and hydraulic operation is demonstrated by applying multiple continuous orientations of principal stress to a homogeneous benchmark sample, and to a fractured sample with a dipole borehole fluid fracture flow experiment, with backpressure. Sample strain for multiple stress orientations is compared to numerical simulations validating the operation of the cell. Fracture permeability as a function of the direction and magnitude of the stress field is presented. Such experiments were not possible to date using current state of the art geotechnical equipment
Quantum-Chemical Justification of the Zeolite Acid Strength Measurement by Infrared Spectroscopy
Quantum-chemical study of hydride transfer in catalytic transformations of paraffins on zeolites
Ab initio quantum-chemical cluster calculations demonstrate that the activated complexes of hydride transfer reaction in catalytic transformations of paraffins on zeolites very much resembles adsorbed nonclassical carbonium ions. The calculated activation energies for reactions involving propane and isobutane are in reasonable agreement with experimental data
A quantum-chemical study of adsorbed nonclassical carbonium ions as active intermediates in catalytic transformations of paraffins. II. Protolytic dehydrogenation and hydrogen-deuterium hetero-isotope exchange of paraffins on high-silica zeolites
Trace gas emissions from a dairy complex measured by mobile in situ and airborne and space-based remote sensing: A COMEX campaign focus
info:eu-repo/semantics/nonPublishe
The Perception of the Greek in the Albanian National Identity-Building Process (1886-1938)
A quantum-chemical study of adsorbed nonclassical carbonium ions as active intermediates in catalytic transformations of paraffins. I. Protolytic cracking of ethane on high silica zeolites
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