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Carbon black (CB) has a wide range of industrial applications and recently has been used as the basic model for environmental health studies on airborne particulate matters (PM). Exposure characterization of CB is always the first and most important step towards a better understanding of its effects on human health. However, efforts were largely limited by the lack of valid methods capable of quantifying CB in biological samples. Here, we developed a new method based on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) for CB quantification in bio-samples, with a detection limit of 4.3 ng. The method is so economical and convenient that it can be performed in most biology labs. The application of the method was successfully demonstrated in three different cell models (mouse macrophage cells (Raw264.7), human epithelial cells (A549) and mouse mesenchymal stem cells (MSC)) and the results showed that the uptake rates decrease in the order of MSC > Raw264.7 > A549. The surprisingly highest uptake rate of MSC deserves further investigation. The novel method provides a complementary quantitative tool to the use of conventional methods such as radioactive and fluorescent labeling and may facilitate related toxicological studies. [ABSTRACT FROM AUTHOR]

A palladium-catalyzed cross-coupling reaction of aryl halides with 2-chlorobenzoic acids has been developed. The reaction forms C(sp3), C(sp2)-palladacycles through C(sp3)–H activation. The palladacycles react with 2-chlorobenzoic acids through two successive C–C cross-couplings, and two C–C bonds are formed with high chemoselectivity. The reaction provides an innovative method for the synthesis of 9,10-dihydrophenanthrenes. [ABSTRACT FROM AUTHOR]

A Pd(II)-catalyzed intermolecular C–H silylation reaction initiated by aminopalladation has been developed. The C–H bonds were activated by an alkyl Pd(II) species generated through aminopalladation and then disilylated with hexamethyldisilane to form disilylated indolines as the final products. The reaction provides a new method for the introduction of silyl groups into complex organic molecules. [ABSTRACT FROM AUTHOR]

A method for the synthesis of enantiopure eight-membered nitrogen heterocycles has been developed through diastereoselective cross-coupling of 2-iodobiphenyls with 2-bromobenzylamines. The products represent a novel type of chiral scaffold, which feature easy modification and high configurative stability and have the potential to be applied in asymmetric synthesis. Palladacycles that were formed via the C–H activation of 2-iodobiphenyls should act as the intermediates. The reaction provides a new strategy for the synthesis of medium-sized ring compounds. [ABSTRACT FROM AUTHOR]