Skin lipids of mice exposed to NO2 contain lipid-soluble nitrosating agent(s) (NSA) that react in vitro with amines to produce nitrosamines. To test whether this reaction occurs in skin, we exposed mice to 50 ppm NO2 for 4 h and, 20 h later, applied 25 mg morpholine or N-methylaniline to the skin, which was then analyzed for the corresponding nitrosamine. When morpholine was applied, mean N-nit...

We have fabricated and tested, to the best of our knowledge, the first microfluidic device monolithically integrated with planar chalcogenide glass waveguides on a silicon substrate. High-quality Ge(23)Sb(7)S(70) glass films have been deposited onto oxide coated silicon wafers using thermal evaporation, and high-index-contrast channel waveguides have been defined using SF(6) plasma etching. Mic...

We demonstrate on-chip laser absorption spectroscopy using silicon microring resonators integrated with PDMS microfluidic channels. A 100 microm radius microring resonator with Q > 100,000 is used to enhance the interaction length between evanescent light and a cladding liquid. We measure absorption spectra of less than 2 nL of N-methylaniline from 1460 nm to 1610 nm with 1 nm resolution and ef...

Biochemical investigations relating to the mechanism of action and mechanism of activation have been made for the carcinogen, 4-chloro-2-methylaniline. Radioactivity from 4-chloro-2-[methyl-14C]methylaniline became extensively bound to protein, DNA, and RNA of rat liver, but macromolecules of some of the other tissues examined contained little radioactivity. Enzymatic activity dependent upon re...

Highly purified liver microsomal cytochrome P-450 catalyzes the hydroperoxide-dependent hydroxylation of a variety of substrates in the absence of NADPH, NADPHcytochrome P-450 reductase, and molecular oxygen. The addition of phosphatidylcholine is necessary for maximal activity. The absence of flavoproteins and cytochrome b, from the cytochromeP-450 preparations rules out the involvement of oth...