Petroleum and its refined products are considered the most complex contaminants frequently impacting the environment in significant quantities. They have heterogeneous chemical composition and alterations occur during environmental weathering. No single analytical method exists to characterize the petroleum-related environmental contamination. For monitoring, the analytical approaches include gravimetric, spectrometric and chromatographic methods having significant differences in their selectivity, sensitivity and cost-effectiveness. Recording fluorescence fingerprints of the cyclohexane extracts of the water, suspended solids, sediment or soil samples and applying appropriate statistical evaluation (e.g. by correlating the concatenated emission spectra of the fingerprints of the samples with arbitrary standards (e.g. petroleum products)), provides a powerful, cost-effective analytical tool for characterization of the type of oil pollution and detecting the most harmful aromatic components of the petroleum contaminated matrix. For monitoring purposes, the level of the contamination can be expressed as the equivalent concentration of an appropriate characteristic standard, based on the fluorescence intensities at the relevant characteristic wavelengths. These procedures are demonstrated in the monitoring of petroleum-related pollution in the water and suspended sediment in the Danube river basin
PD-1/SHP-2 negatively regulate Tc1/Th1 phenotypic responses and activation of T cells in the tumor microenvironment