The importance of micro RNA analysis has been significantly increasing because the role of micro RNA in the human body has been gradually revealed. Despite its importance, the analysis has suffered from several troublesome pretreatments, which hamper any easy analysis. Therefore, an easy and high-throughput pretreatment method has been demanded. In this paper, we focused on the great advantages of microchip pretreatments over conventional manual pretreatments and developed a microchip for micro RNA extraction. To simplify microchip fabrication, we adopted poly(dimethyl siloxane) (PDMS) microchip and a silica membrane, which has rolls in RNA extraction fields. With silica membranes and the adhesion nature of PDMS, we could easily fabricate RNA extraction fields in the microchip. With this microchip, we successfully extracted micro RNA from cancer tumor cells. Though this is a preliminary experiment, and still has many improvement points, our device is expected to be applied for easy and fast micro RNA extraction from biological samples.
社会で使用される化学物質は急速に増加しており，環境や食品の安全性評価，事故の原因究明や災害後の二次被害防止には，多数の化学物質を分析することが望ましい．しかし，化学物質分析に汎用されるガスクロマトグラフィー質量分析（GC/MS）では，同定のための標準物質測定が必要であり，測定物質数を制限している．一方，保持時間の固定や予測を用いた標準物質不要の同定システムも市販されているが，特定機器でしか使用できない．本研究では，市販のガスクロマトグラフ質量分析計（GC―MS）で標準物質を用いずにデータベース登録物質を検出する汎用ターゲットスクリーニングシステムを検討した．本システムは，アメリカ国立標準技術研究所（National Institute of Standards and Technology, NIST）のAutomated Mass Spectral Deconvolution and Identification System（AMDIS）に昇温保持指標とマススペクトルを組み込んだものである．データベース作成時と同一条件で試料を測定することで，使用装置に拘わりなく保持時間を精確に予測し，マススペクトルと併せて確実に同定できる．現在の登録物質数は約1000であるが，容易に物質を追加でき，上記だけでなく薬物検出など多方面で活用できる．
Since quantitative values on the basis of a nucleus can be obtained by nuclear magnetic resonance (NMR) spectroscopy, the quantitative NMR technique requires no identical standard. For this reason, it is expected to be a universal quantitative method. However, the quantification using an NMR requires a high resolution NMR spectrometer in NMR measurement. In this paper, we discuss the quantitative NMR method using a benchtop NMR spectrometer with a low magnetic field. We studied the conditions of NMR measurement and data process. The precision of the result was evaluated with approximately 1% using a benchtop spectrometer. Especially, the low S/N and large FWHS of the NMR signals caused low repeatability.
Gaseous chemical compounds such as carbonyls, volatile organic compounds (VOC), acid gases, basic gases, and ozone were measured in indoor and outdoor air of 40 houses throughout Sapporo city in the winter (January to March, 2012 and 2013) and summer (July to September, 2012) using four kinds of diffusive samplers. Almost all compounds in indoor air were present at higher levels in the summer than in the winter. The indoor concentrations of acetaldehyde and p-dichlorobenzene exceeded the Health, Labour and Welfare, Japan guideline in three and two houses, respectively. The mean concentrations of formaldehyde were 27 μg m−3 in the summer and 17 μg m−3 in the winter, and showed that the summer concentration was 1.6-fold higher than that in the winter. Nitrogen dioxide was present in extremely high concentrations in the winter, and it was suggested that the sources of nitrogen dioxide in indoor air are kerosene heaters, unvented gas stoves and heaters. Formic acid was generated by combustion because the nitrogen dioxide concentration in indoor air was well correlated with the formic acid concentration (correlation coefficient = 0.947). In outdoor air, the negative correlation between nitrogen dioxide and ozone was observed during the winter. It was suggested that the reaction of nitric oxide and ozone may influence the formation of nitrogen dioxide.