Kinetics and mechanism of Eu(III) transfer in tributyl phosphate microdroplet/HNO3 aqueous solution system revealed by fluorescence microspectroscopy.

In this study, we reveal an Eu(III) extraction mechanism at the interface between HNO3 and tributyl phosphate (TBP) solutions using fluorescence microspectroscopy. The mass transfer rate constant at the interface is obtained from the analysis of fluorescence intensity changes during the forward and backward extractions at various HNO3 and TBP concentrations to investigate the reaction mechanism. This result indicates that one nitrate ion reacts with Eu(III) at the interface, whereas TBP molecules are not involved in the interfacial reaction, which is different from the results obtained using the NaNO3 solution in our previous study. We demonstrate that the chemical species of Eu(III) complex with nitrate ion and TBP in the aqueous solution play an important role for the extraction mechanism. The rate constants of the interfacial reactions in the forward and backward extractions are (4.0-5.0) × 10-7 m M-1 s-1 and (3.2-3.3) × 10-6 m s-1, respectively. We expect that our revealed mechanism provides useful and fundamental knowledge for actual solvent extraction.

Investigation into the plasma concentration of ω3 polyunsaturated fatty acids in Japanese attention-deficit hyperactivity disorder patients.

Several studies report that patients with attention-deficit hyperactivity disorder (ADHD) have a low plasma concentration of polyunsaturated fatty acids (PUFAs). Since fish intake varies among countries and is high in Japan, those results may not apply to Japanese patients with ADHD. However, there is currently not enough evidence to support this. We compared the plasma PUFAs levels of patients with ADHD with the standard reference levels for healthy subjects, and examined the relationship between those PUFAs levels and the subject's psychological evaluation. The subjects were 24 patients (age < 20 years) previously diagnosed with ADHD (according to the DSM-IV-TR criteria) at the psychiatric department of the Nagasaki University Hospital, between November 2010 and November 2015. The plasma concentrations of docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA), and arachidonic acid (AA) were measured using gas chromatography. Data pertaining to global assessment of functioning (GAF), clinical global impressions, ADHD Rating Scale-IV, and the drug used for treatment (atomoxetine or methylphenidate) were obtained from the medical records. The plasma concentrations of DHA, EPA, and EPA/AA were significantly lower than the normal reference range, indicating that ADHD patients present an imbalance in PUFAs levels. This trend is similar to ADHD patients in other countries and replacement therapy in Japanese ADHD patients may be useful.