Lean non-alcoholic fatty liver disease (Lean-NAFLD) and the development of metabolic syndrome: a retrospective study.

Lean NAFLD is a special phenotypic closely correlated with metabolic syndrome (MS). The aim of this study is to investigate the MS development and the gender differences in lean NAFLD population. Participants were divided into 4 groups by BMI and NAFLD status. Descriptive analysis was performed to characterize baseline information. A total of 18,395 subjects were participated, and 1524 incident cases of MS were documented. Then, Kaplan-Meier curves were used to present the MS outcomes in different groups, and the NAFLD was found to be a riskier factor than obesity for MS. Subgroup analysis showed significantly higher MS incidence in female than male among lean NAFLD group, which is different from other groups. Although with higher prevalence in male, lean NAFLD seems to be a more harmful phenotype for females according to the TG, ALT and GGT levels. The logistic regressive analysis was performed to show the impact of NAFLD status and BMI changes on MS risk. Lean non-NAFLD subjects merely developed to NAFLD with no BMI status changes exhibited highest MS risk (ORs = 1.879, 95% CI 1.610-2.292) than that with both BMI increase and NAFLD development (ORs = 1.669, 95% CI 1.325-2.104). It also suggests the metabolic specificity of this population.

Optical-feedback cavity ring-down spectroscopy for NO2 extinction coefficient measurement using a continuous wave laser diode.

Optical-feedback (OF) cavity ring-down spectroscopy consisting of a linear cavity is developed by employing a continuous wave laser diode (LD) with multi-longitudinal modes. Due to the OF effect caused by the cavity output laser back into the LD, the laser frequency is locked, and the intracavity laser intensity is enhanced. We use different concentrations of NO2 gases to test the apparatus, and the results show good agreement with theoretical values. Owing to the compactness of the laser source and high detection accuracy, the device can be used for detection of low-concentration absorbent gases in the environmental monitoring field.

Salt crust-assisted thermal decomposition method for direct and simultaneous quantification of polypropylene microplastics and organic contaminants in high organic matter soils.

Direct quantitative analysis of soil polypropylene microplastics (MPs) via thermal method is still a challenge due to its sensitivity to the soil matrix during the thermal decomposition. In this work, the impact of soil organic matter (SOM) on MPs decomposition in real soil was estimated, and high SOM contents was found have significantly negative effect on the qualitative and quantitative analysis of PP. To solve this problem, a salt crust-assisted thermal decomposition method was developed to reduce the soil matrix effect. By adding salt solution and heating in appropriate temperature program, salt crust can be formed between MPs and soil matrix to isolate PP MPs and soils during the heating process, and thereby to avoid the influence of SOM. Thermal desorption/decomposition coupling with headspace solid phase microextraction (HS-SPME) was used extraction of MPs decomposition products. All the thermal decomposition products of PP were identified, several alkenes and dialkenes were selected as candidates for quantitative analysis, and 2,4,6,8,10-pentamethyltridec-1-ene with optimal linearity was finally established for quantification. Besides, this method was also established for simultaneous determination of PP MPs and organic contaminants (OCs) including PCBs and PAHs, since it is capable of providing a new approach for investigation of their interaction in real soil environment. A theoretical LOD of 0.002 wt% was obtained for PP MPs, and the LOD of OCs ranges from 0.05 to 1.87 ng/g. Determination of aged soil samples reveal that adsorption of OCs is not a predominating effect of MPs in soil environment, and MPs contaminants may reduce the soil retention capacity. This method provides a new approach for direct quantification of soil PP MPs, and applicable for investigation of the interactions between MPs and OCs in real soils.