著者

Taeko Mizutani Ryota Mori Misaki Hirayama Yuki Sagawa Kenji Shimizu Yuri Okano Hitoshi Masaki

出版者

Japan Oil Chemists' Society

雑誌

Journal of Oleo Science (ISSN:13458957)

巻号頁・発行日

vol.65, no.12, pp.993-1001, 2016 (Released:2016-12-01)

参考文献数

35

被引用文献数

24 24

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Sodium lauryl sulfate (SLS), a representative anionic surfactant, is well-known to induce rough skin following single or multiple topical applications. The mechanism by which SLS induces rough skin is thought to result from the disruption of skin moisture function consisting of NMF and epidermal lipids. However, a recent study demonstrated that topically applied SLS easily penetrates into the living cell layers of the epidermis, which suggests that physiological alterations of keratinocytes might cause the SLS-induced rough skin. This study was conducted to clarify the effects of SLS on keratinocytes to demonstrate the contribution of SLS to the induction of rough skin. In addition, the potentials of other widely used anionic surfactants to induce rough skin were evaluated. HaCaT keratinocytes treated with SLS had increased levels of intracellular ROS and IL-1α secretion. Application of SLS on the surface of a reconstructed epidermal equivalent also showed the increased generation of ROS. Further, SLS-treated cells showed an increase of intracellular calpain activity associated with the increase of intracellular Ca2+ concentration. The increase of intracellular ROS was abolished by the addition of BAPTA-AM, a specific chelator of Ca2+. In addition, IL-1α also stimulated ROS generation by HaCaT keratinocytes. An ESR spin-labeling study demonstrated that SLS increased the fluidity of membranes of liposomes and cells. Together, those results indicate that SLS initially interacts with cell membranes, which results in the elevation of intracellular Ca2+ influx. Ca2+ stimulates the secretion of IL-1α due to the activation of calpain, and also increases ROS generation. IL-1α also stimulates ROS generation by HaCaT keratinocytes. We conclude from these results that the elevation of intracellular ROS levels is one of the causes of SLS-induced rough skin. Finally, among the other anionic surfactants tested, sodium lauryl phosphate has less potential to induce rough skin because of its lower generation of ROS.

著者

Kenji Shimizu Takayuki Ushikubo Takeshi Kuritani Naoto Hirano Shigeru Yamashita

出版者

GEOCHEMICAL SOCIETY OF JAPAN

雑誌

GEOCHEMICAL JOURNAL (ISSN:00167002)

巻号頁・発行日

pp.GJ22019, (Released:2022-11-22)

被引用文献数

1

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Analyses of elemental abundances by secondary ion mass spectrometry (SIMS) require matrix-matched standard samples to account for the matrix effect on correction factors. This requirement makes it difficult to obtain accurate results for geological samples of variable chemistry. In this study, we prepared 39 volcanic glasses of foiditic, basaltic, basaltic andesitic, rhyolitic and pure SiO2 compositions, including synthetic samples and natural samples collected from the deep seafloor. The measured H2O contents of these samples were in the range 0.02–4.8 wt%. We showed that calibration curves (H2O content vs. 16OH−/30Si−SIMS ratio) differed according to the composition of the volcanic glasses. Our results demonstrated that for a particular 16OH/30SiSIMS ratio, water content could differ by up to a factor of five, depending on the composition of the volcanic glass. Although the correction factor (the slope of the calibration curve for water [H2O/(16OH−/30Si−)SIMS]) was weakly correlated with SiO2 content, we identified a stronger correlation with the molar weight (g mol−1, on a one-oxygen mole basis) of the silicate glasses. Our results suggest that modification of the correction factor for the matrix effect on SIMS-based H2O content of volcanic glasses according to their molar weights provides more accurate water contents of silicate glasses, regardless of their chemical composition and water content and without the need for a series of standard glasses of known water contents.

著者

Hiroyasu Sato Norihito Doki Masaaki Yokota Kenji Shimizu Shingo Yano

出版者

The Society of Chemical Engineers, Japan

雑誌

JOURNAL OF CHEMICAL ENGINEERING OF JAPAN (ISSN:00219592)

巻号頁・発行日

vol.48, no.11, pp.903-908, 2015-11-20 (Released:2015-11-20)

参考文献数

13

被引用文献数

1

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A new optical resolution method is proposed in which one enantiomer of a racemic mixture is replaced with a tailor-made additive, and the displaced enantiomer is crystallized. DL-Aspartic acid (Asp) was examined as a model racemic compound. First, L-Asp crystallization was examined in the presence of L-asparagine (Asn) or D-Asn. The effect of Asn was chirality-specific; L-Asn specifically replaced some of the L-Asp in the crystal lattice and solid solutions of L-Asp with L-Asn formed. Secondly, DL-Asp crystallization was examined in the presence of L-Asn, and the obtained crystals were solid solutions of DL-Asp with L-Asn partially replacing L-Asp in the DL-Asp crystal lattice. Finally, crystallization of the L-Asp in the filtrate of the DL-Asp crystallization in the presence of L-Asn was examined. The obtained crystals were a mixture of solid solutions of L-Asp with L-Asn and solid solutions of DL-Asp with L-Asn. Moreover, when D-Asn was added to the DL-Asp crystallization, a mixture of solid solutions of D-Asp with D-Asn and solid solutions of DL-Asp with D-Asn was crystallized from the filtrate. These results show that racemic compounds could be resolved by the proposed method.