- 著者
- Yuki Igarashi Miki Takahashi Tomoaki Tsutsumi Koichi Inoue Hiroshi Akiyama
- 出版者
- The Pharmaceutical Society of Japan
- 雑誌
- Chemical and Pharmaceutical Bulletin (ISSN:00092363)
- 巻号頁・発行日
- vol.69, no.3, pp.286-290, 2021-03-01 (Released:2021-03-01)
- 参考文献数
- 26
- 被引用文献数
- 7
Monitoring analysis of 14 per- and polyfluoroalkyl substances (PFAS), 9-chlorohexadecafluoro-3-oxanonane-1-sulfonate (F-53B) and dodecafluoro-3H-4,8-dioxanonanoate (ADONA) in bottled drinking water, tea and juice samples was performed using LC coupled with tandem mass spectrometry (LC-MS/MS) and solid-phase extraction (SPE). In the electrospray negative ion mode, the limit of detection and limit of quantification (LOQ) values were 0.1 to 0.8 ng/mL and 0.2 to 1.6 ng/mL, respectively. The calibration curves were linear from LOQ to 50 ng/mL (r2 > 0.999). The SPE procedure (Presep PFC-II) was utilized for sample preparation and recovery rates for three standards (35, 70 and 140 ng/L) were 80.4–118.8% with relative standard deviation (RSD) ≤ 0.6%. Using the developed method, various samples (n = 54) from Japanese markets were investigated for PFAS and F-53B contamination, and values below the LOQ were observed. It is concluded that for monitoring products in the Japanese market, our method represents a significant improvement over complex techniques for the quantification of PFAS and related compounds from various foods.
- 著者
- Shiori TAKASHINA Yuki IGARASHI Miki TAKAHASHI Yukie KONDO Koichi INOUE
- 出版者
- The Japan Society for Analytical Chemistry
- 雑誌
- Analytical Sciences (ISSN:09106340)
- 巻号頁・発行日
- vol.36, no.11, pp.1427-1430, 2020-11-10 (Released:2020-11-10)
- 参考文献数
- 23
- 被引用文献数
- 10
A sensitive, useful and preliminary screening method was proposed to quantitate the containable cannabinoids most commonly included in mineral water and gummi candy products, specifically cannabidiol (CBD), cannabinol (CBN), 11-nor-9-carboxy-Δ9-tetrahydrocannabinol (THCA), cannabigerol (CBG), and cannabidiolic acid (CBDA), using liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) for quality evaluations. Based on the electrospray positive ion mode, the limit of detection and the limit of quantification values were 0.2 to 0.5 ng/mL and 0.8 and 2.0 ng/mL. Samples (0.5 g) were diluted by water/methanol (50/50), to which stable isotope internal standards were added; the recovery results appeared in range from 91.3 to 101.2%. This method was applied to evaluate CBD products (6 kinds) from the Japanese market. Our survey found obvious discrepancies between the labeling and the results were overserved in products. In addition, CBN, THCA, CBG, and CBDA were not detected in full-spectrum products that contained various cannabinoids that naturally occur in the cannabis plant. Thus, it is necessary to be able to verify the accurate concentration and impurity in various CBD products from the Japanese market as quickly as possible.
- 著者
- Nitish RAJORIA Yuki IGARASHI Jin MITSUGI Yusuke KAWAKITA Haruhisa ICHIKAWA
- 出版者
- The Institute of Electronics, Information and Communication Engineers
- 雑誌
- IEICE Transactions on Communications (ISSN:09168516)
- 巻号頁・発行日
- pp.2016EBP3472, (Released:2017-06-13)
- 被引用文献数
- 3 11
This paper proposes a novel multiple access method that enables concurrent sensor data streaming from multiple batteryless, wireless sensor tags. The access method is a pseudo-FDMA scheme based on the subcarrier backscatter communication principle, which is widely employed in passive RFID and radar systems. Concurrency is realized by assigning a dedicated subcarrier to each sensor tag and letting all sensor tags backscatter simultaneously. Because of the nature of the subcarrier, which is produced by constant rate switching of antenna impedance without any channel filter in the sensor tag, the tag-to-reader link always exhibits harmonics. Thus, it is important to reject harmonics when concurrent data streaming is required. This paper proposes a harmonics rejecting receiver to allow simultaneous multiple subcarrier usage. This paper particularly focuses on analog sensor data streaming which minimizes the functional requirements on the sensor tag and frequency bandwidth. The harmonics rejection receiver is realized by carefully handling group delay and phase delay of the subcarrier envelope and the carrier signal to accurately produce replica of the harmonics by introducing Hilbert and inverse Hilbert transformations. A numerical simulator with Simulink and a hardware implementation with USRP and LabVIEW have been developed. Simulations and experiments reveal that even if the CIR before harmonics rejection is 0dB, the proposed receiver recovers the original sensor data with over 0.98 cross-correlation.
- 著者
- Shiori TAKASHINA Yuki IGARASHI Miki TAKAHASHI Yukie KONDO Koichi INOUE
- 出版者
- The Japan Society for Analytical Chemistry
- 雑誌
- Analytical Sciences (ISSN:09106340)
- 巻号頁・発行日
- pp.20N015, (Released:2020-07-24)
- 被引用文献数
- 10
- 著者
- 五十嵐 悠紀 五十嵐 健夫 鈴木 宏正 Yuki Igarashi Takeo Igarashi Hiromasa Suzuki 東京大学大学院工学系研究科 東京大学大学院情報理工学系研究科:JST ERATO 東京大学大学院工学系研究科 Dept. of Engineering The University of Tokyo Dept. of Information Science and Technology The University of Tokyo:JST ERATO Dept. of Engineering The University of Tokyo
- 雑誌
- コンピュータソフトウェア = Computer software (ISSN:02896540)
- 巻号頁・発行日
- vol.26, no.1, pp.51-58, 2009-01-27
"あみぐるみ"は毛糸を使って作るぬいぐるみであるが,毛糸の編み方によって形状をデザインしていくため,初心者にはデザインすることが困難である.我々は3次元モデリングプロセスにインタラクティブな物理シミュレーションを組み合わせることであみぐるみを効率的にデザインできるモデラーを作成した.本システムは自動で編み目を計算してあみぐるみモデルをシミュレーション結果として提示するため,初心者にでも直感的にデザインでき,編み図も容易に得ることができる.また,初めてあみぐるみに挑戦する初心者でも製作手順を容易に理解できるようにするために,製作手順を視覚的に提示する製作支援インタフェースも備えた.あみぐるみ初心者でも容易にオリジナルなあみぐるみを作成できることを確認したので報告する.