Rare earth element (REE) concentrations were determined in 32 rainfall events collected in suburban Tokyo. Two or more samples were collected for 13 events out of 32 events. A pre-concentration method was applied using a chelate resin solid phase extraction column. Good and uniform recoveries for REEs (Y to Lu, 99~101% at pH = 3.7~4.0) were obtained. Detection limits reached as low as 0.001 ng L -1 (for Tb) with a 30 fold pre-concentration using a conventional Q-pole ICP-MS. Clear La and Gd excesses (definition is in the text) were evident in many cases. Y, Eu, Lu and Yb excesses may also exist in some events. In some events where multiple samplings were performed, crust normalized REE patterns changed during the rainfall events. These are the first evidences of clear REE pattern variations during the same rainfall events. The initial and final stage of some rainfall events may have different origins for the REEs. The correlations among the REEs with respect to logarithmic concentrations indicate that most of the REEs are of natural origin while La and Gd may have common anthropogenic components. We propose that materials for high refractive index and low dispersion optical glass production processes could be potential sources of La and Gd excesses because 1) La and Gd excesses are correlated, 2) other sources such as a cracking catalyst for petroleum refining or a contrast agent of magnetic resonance imaging cannot explain the excesses.
The heterodyne transient grating (HD-TG) method was first applied to the curing dynamics measurement of photopolymers. The curing dynamics for various monomers including an initiator (2.5 vol%) was monitored optically via the refractive index change after a single UV pulse irradiation. We could obtain the polymerization time and the final change in the refractive index, and the parameters were correlated with the viscosity, molecular structure, and reaction sites. As the polymerization time was longer, the final refractive change was larger, and the polymerization time was explained in terms of the monomer properties.
Pseudohyperaldosteronism can be induced by the excessive use of Chinese herbal medicines (Kampo medicines), resulting in serious disorders. We report a case of pseudohyperaldosteronism induced by two Kampo medicines which resulted in severe hypokalemia. A 70-year-old woman was hospitalized for a left calcaneal fracture. She had no subjective symptoms other than trauma. On her admission, blood test results revealed a low serum potassium level of 2.4 mmol/L by chance, as well as low levels of both renin and aldosterone. The patient had been taking 5 g of Yokukansan per day for the past three months. In addition, she was on 5 g Shakuyakukanzoto per day for three months until a month prior to hospitalization. The daily licorice content from the aforementioned herbs was 1.0 g and 4.0 g, respectively. After hospitalization, the administration of the Kampo medicines was discontinued, and 610 mmol of potassium was administered over a period of 13 days, which resulted in the normalization of serum potassium levels. Pre-existing hypertension slowly improved as well. Patients consuming licorice at doses of 2.5 g per day or more, as in our case, are at a high risk of developing pseudohyperaldosteronism. Furthermore, the risk is particularly high with long-term licorice consumption as well as for women and elderly patients. To this end, high-dose potassium supplementation may be necessary for normalizing serum potassium levels. Therefore, awareness regarding the adverse effects of licorice is crucial, even in cases of low dosages of licorice.
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