RESUMEN
BACKGROUND: It is still unknown whether unsaturated fatty acids (UFA) have the same effect on preventing cognitive impairment in chronic kidney disease (CKD) patients as in healthy people. OBJECTIVE: To investigate the protective effect of dietary UFA intake and proportion on cognitive impairment in patients with CKD. METHODS: We extracted data from the National Health and Nutrition Examination Survey (NHANES, 2011-2014) on participants with a previous diagnosis of CKD and at least one complete cognitive assessment (Consortium to Establish a Registry for Alzheimer's Disease test, Animal Fluency Test and Digit Symbol Substitution Test). We used the lower quartile of the total scores of these three tests as the cut-off point, and divided the participants into two groups of normal cognitive performance and low cognitive performance to extract participants' intake of various UFA from the NHANES dietary module.
RESUMEN
Per- and polyfluoroalkyl substances (PFAS) is an emerging class of organic pollutants of concern and is now prevalent in environmental matrices including water, soil, air, and biological. So far, several standard analytical methods have been developed to systematically analyze PFAS in different environmental matrices. However, the complexity of environmental matrices makes the effective extraction of PFAS difficult, and the legacy PFAS is gradually changing into a new PFAS with short chain and unknown structure in production, which makes the analysis of PFAS challenging. In this review, the following aspects are summarized: (1) the advances in standard analytical methods for PFAS in different environmental matrices, and further generalizes the updating novel extraction and detection methods; (2) the analysis of unknown PFAS, the suspect and non-targeted screening analysis method of PFAS based on high-resolution mass spectrometry (HRMS) is systematically described.
RESUMEN
Perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS) are typical emerging persistent organic pollutants that are raising concerns regarding their environmental persistence. The photodegradation of these chemicals in water can be promoted by generating hydrated electrons (eaq-). The present work demonstrates a highly efficient process combining ultraviolet (UV) radiation, hydrochar (H-BC) and KI that is capable of decomposing PFOA and PFOS. After 60 min of photolysis using this technique, 99.5 % and 94.1 % of the initial amounts of PFOA and PFOS in aqueous solution were degraded, respectively, with corresponding defluorination percentages of 87.8 % and 71.7 %, respectively. These degradation values were higher than the sum of those obtained using UV radiation with only H-BC or KI, implying a synergistic effect from the combination of H-BC and KI. This effect can be attributed to the unique structure and numerous oxygen-containing functional groups of the H-BC. This material was able to absorb PFOA and PFOS, reduce iodide oxidation products back to I-, act as an electron shuttle and shorten the diffusion distance to the target substrate. These factors all increased the probability of reactions between the contaminants and eaq-. Analyses by liquid chromatography/electrospray ionization/tandem mass spectrometry showed that short-chain perfluoroalkyl carboxylic acids with less than seven carbons were the primary degradation intermediates, suggesting that the photodegradation proceeded stepwise. These results confirmed the cooperative effect of the H-BC and iodide, leading to effective eaq- generation. This work is expected to facilitate the development of new strategies for the treatment of water systems contaminated with PFOA and PFOS.