This study assessed polycyclic aromatic hydrocarbon (PAH) association and aqueous partitioning in lampblack-impacted field soils from five sites in California that formerly housed oil-gas process operations. Lampblack is the solid residue resulting from the decomposition of crude oil at high temperatures in the gas-making operation and is coated or impregnated with oil gasification byproducts, among which PAHs are the compounds of the greatest regulatory concern. A suite of complementary measurements investigated the character of lampblack particles and PAH location and the associated effects on PAH partitioning between lampblack and water. PAH analyses on both whole samples and density-separated components demonstrated that 81-100% of PAHs in the lampblack-impacted soils was associated with lampblack particles. FTIR, 13C NMR, and SEM analyses showed that oil-gas lampblack solids comprise primarily aromatic carbon with soot-like structures. A free-phase aromatic oil may be present in some of the lampblack soils containing high PAH concentrations. Comparable long-term aqueous partitioning measurements were obtained with an air-bridge technique and with a centrifugation/alum flocculation procedure. Large solid/water partition coefficient (Kd) values were observed in samples exhibiting lower PAH and oil levels, whereas smaller Kd values were measured in lampblack samples containing high PAH levels. The former result is in agreement with an oil-soot partitioning model, and the latter is in agreement with a coal tar-water partitioning model. Lampblack containing high PAH levels appears to exhaust the sorption capacity of the soot-carbon, creating a free aromatic oil phase that exhibits partitioning behavior similar to PAHs in coal tar. This study improves mechanistic understanding of PAH sorption on aged lampblack residuals at former oil-gas sites and provides a framework for mechanistic assessment of PAH leaching potential and risk from such site materials.

Numerous studies have shown that mammalian target of rapamycin (mTOR) inhibitor activates Akt signaling pathway via a negative feedback loop while inhibiting mTORC1 signaling. In this report, we focused on studying the role of mTORC1 and mTORC2 in rapamycin-mediated Akt and ERK phosphorylation, and the antitumor effect of rapamycin in cancer cells in combination with Akt and ERK inhibitors. Moreover, we analyzed the effect of mTORC1 and mTORC2 on regulating cell cycle progression. We found that low concentrations rapamycin increased Akt and ERK phosphorylation through a mTORC1-dependent mechanism because knockdowned raptor induced the activation of Akt and ERK, but higher doses of rapamycin inhibited Akt and ERK phosphorylation mainly via the mTORC2 signaling pathway because that the silencing of rictor led to the inhibition of Akt and ERK phosphorylation. We further showed that mTORC2 was tightly associated with the development of cell cycle through an Akt-dependent mechanism. Therefore, we combined PI3K and ERK inhibitors prevent rapamycin-induced Akt activation and enhanced antitumor effects of rapamycin. Collectively, we conclude that mTORC2 plays a much more important role than mTORC1 in rapamycin-mediated phosphorylation of Akt and ERK, and cotargeting AKT and ERK signaling may be a new strategy for enhancing the efficacy of rapamycin-based therapeutic approaches in cancer cells.

Supercritical carbon dioxide was used as a reaction medium to synthesize statistically random (i.e., no specific correlation between the location of the monomers on the polymer) copolymers of tetrafluoroethylene (TFE) and vinyl acetate (VAc) with similar molar mass and 11.6-63.3 mol % TFE content. The solubility of the copolymers at 25°C in CO 2 reduced after reaching a maximum value at a TFE molar concentration of 19.3 mol %. The 46.7 mol % TFE copolymer only dissolved in CO2 at elevated temperatures, whereas the 63.3 mol % TFE copolymer did not dissolve in CO2 even at temperatures in excess of 144°C and pressures of 210 MPa. The molecular modeling results show that the interaction of CO2 with acetate side group was not affected by presence of fluorine in the polymer backbone; therefore, the enhanced solubility of the semifluorinated copolymers is attributable to the enhanced binding between CO2 and the semifluorinated backbone of the copolymer when the CO2 molecule can access both the fluorinated (Lewis base) and hydrogenated (Lewis acid) parts of the backbone simultaneously.

A novel method for the postcombustion capture of CO 2 from coal-fired power plants has been described utilizing an aminosilicone absorbent. 1,3-Bis(3-aminopropyl)-1,1,3,3-tetramethyldsiloxane (GAP-0) rapidly transforms from a low viscosity liquid to a friable solid upon exposure to CO 2 in simulated flue gas. This material has excellent thermal stability, low vapor pressure, high CO 2 loading capability, and a large dynamic CO 2 capacity between rich and lean solvent loadings. Preliminary plant and process models assembled from experimental data show a decrease in parasitic energy loss from 30% to 18% when compared to the benchmark monoethanolamine (MEA) process and a concomitant lowering of the cost of electricity (COE) from 74% to 44% increase versus a plant without carbon capture.