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Heptafluoropropane (HFP), as the best alternative to halon fire-suppression agents, is now a widely used fire extinguishing agent. The current studies of HFP, concentrating on the extinguishing mechanisms of flames and decomposition products, in general deal with the destructive and high temperature cases. In this paper, terahertz time-domain spectra are used to characterize HFP at different pressures. Optical parameters of HFP, such as absorption coefficient, refractive index, and relative permittivity, and their relationship with concentration of samples, are discussed. The absorption peak of HFP at 0.3 THz depends strongly on the applied pressure, and the corresponding parameters increase almost linearly with increasing HFP concentration. The present study lays a foundation for future extensive applications. [ABSTRACT FROM AUTHOR]

The nuclear receptors (NR)-farnesoid X receptor (FXR, NR1H4) and pregnane X receptor (PXR, NR1I2)-have important effects on the expression of genes related to the pharmacokinetics (PKs) of rosuvastatin. This study was designed to investigate whether the genetic variants in drug disposition genes (SLCO1B1 and ABCG2) combined with their upstream regulators (NR1H4 and NR1I2) would affect the PKs of rosuvastatin in a Chinese population. Sixty-one healthy male volunteers were enrolled and the plasma concentrations of rosuvastatin were measured using the liquid chromatographic-tandem mass spectrometry/MS method. All subjects were analyzed and grouped according to the genotypes of NR1H4, NR1I2, SLCO1B1, and ABCG2. The exposure of rosuvastatin was higher in subjects carrying the SLCO1B1 521C or ABCG2 421A allele compared with noncarriers. No association was observed of single-nucleotide polymorphisms in NR1H4 or NR1I2 genes with the PKs of rosuvastatin. After adjusting for the 421C>A and 521T>C variants, the Cmax in subjects with NR1I2 63396TT wild type were about 2-fold of those of NR1I2 mutant type (63396CC and CT) (10.7 vs. 20.4 ng/mL, P = 0.023), whereas no significant differences were observed for other parameters. Polymorphisms investigated in the genes of NR1H4 and NR1I2 seemed to play no significant role in the disposition of rosuvastatin.