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We report the observation and theoretical analysis of photothermal phase modulation in an optical nanofiber (NF) immersed in light-absorbing gas. The phase modulation arises from the contrasting photothermal processes experienced by the mode field within and outside the NF, which exhibits significant wavelength and pressure dependence in the nanoscale waveguides. By designing the diameter of the NF, the photothermal phase modulation can be readily controlled, and a nullification of phase modulation is achieved at a specific wavelength. Experiments on NFs with different diameters demonstrated pressure-controllable phase modulation up to 0.058π rad/mW, potentially allowing the development of nanoscale all-optical modulators and sensors with optimal performance. [ABSTRACT FROM AUTHOR]

Chlorinated paraffins (CPs), which were conventionally classified into short- (SCCPs), medium- (MCCPs) and long- (LCCPs) chain CPs, have received growing attention due to their wide usage and extensive detection in environmental samples and biota. The number of studies regarding the biomonitoring of CPs in human beings increased rapidly and their health risk gained great concern. This review summarized their occurrence and homologue patterns in human matrices including blood/serum, placenta, cord serum and breast milk. As the production and usage of SCCPs was progressively banned after being listed in Annex A of the Stockholm Convention, the production of MCCPs and LCCPs was stimulated. Accordingly, the ratio of MCCPs/SCCPs in human samples has increased rapidly in the last 5 years. The current understanding of exposure routes and risk assessments of CPs was also reviewed. Oral dietary intake is the most predominant source of daily CP intake, but dust ingestion, inhalation and dermal exposure is also nonnegligible, especially for MCCPs and LCCPs. Furthermore, the reported upper bound of the estimated daily intakes (EDIs) in various risk assessment studies was close to or exceeded the tolerable daily intakes (TDIs). Considering the bioaccumulation and long-lasting exposure of CPs, their health impacts on humans and the ecosystem required continuous monitoring and evaluation. [ABSTRACT FROM AUTHOR]