Medical herbs have been recognized till now as having different constituents that act on the human body. However, the fragrance of herbs is a complex mixture of odors, which makes it difficult to qualify or quantify the scent objectively on the human sense of smell. In this study, aromas of 15 medicinal herbs were recorded using an electronic nose FF-2A, and their characteristics were compared with aroma samples of wine such as Le Nez du Vin, to determine which wine aromas are similar to each medicinal herb. Thereafter, the aromas of the 15 herbs were standardized to create a reference axis for the aroma of each herb, and the similarity of tea herbs to the reference axis was examined. Additionally, the results were compared with those obtained by gas chromatography-mass spectrometry (GC-MS). In FF-2A, the measured scent is recorded as an absolute value. We succeeded in calculating the similarity of the scents of other herbs with the axes of the scent of each herb by standardizing their scents and creating new axis data. Conversely, although GC-MS is able to identify the components and concentrations of fragrances, an electronic nose can analyze fragrances in a way that is uncommon with GC-MS, such as comparison of similarities between fragrances.
Genome editing techniques such as CRISPR/Cas9 have both become common gene engineering technologies and have been applied to gene therapy. However, the problems of increasing the efficiency of genome editing and reducing off-target effects that induce double-stranded breaks at unexpected sites in the genome remain. In this study, we developed a novel Cas9 transduction system, Exci-Cas9, using an adenovirus vector (AdV). Cas9 was expressed on a circular molecule excised by the site-specific recombinase Cre and succeeded in shortening the expression period compared to AdV, which expresses the gene of interest for at least 6 months. As an example, we chose hepatitis B, which currently has more than 200 million carriers in the world and frequently progresses to liver cirrhosis or hepatocellular carcinoma. The efficiencies of hepatitis B virus genome disruption by Exci-Cas9 and Cas9 expression by AdV directly (Avec) were the same, about 80–90%. Furthermore, Exci-Cas9 enabled cell- or tissue-specific genome editing by expressing Cre from a cell- or tissue-specific promoter. We believe that Exci-Cas9 developed in this study is useful not only for resolving the persistent expression of Cas9, which has been a problem in genome editing, but also for eliminating long-term DNA viruses such as human papilloma virus.
Genome editing techniques such as CRISPR/Cas9 have both become common gene engineering technologies and have been applied to gene therapy. However, the problems of increasing the efficiency of genome editing and reducing off-target effects that induce double-stranded breaks at unexpected sites in the genome remain. In this study, we developed a novel Cas9 transduction system, Exci-Cas9, using an adenovirus vector (AdV). Cas9 was expressed on a circular molecule excised by the site-specific recombinase Cre and succeeded in shortening the expression period compared to AdV, which expresses the gene of interest for at least six months. As an example, we chose hepatitis B, which currently has more than 200 million carriers in the world and frequently progresses to liver cirrhosis or hepatocellular carcinoma. The efficiencies of hepatitis B virus genome disruption by Exci-Cas9 and Cas9 expression by AdV directly (Avec) were the same, about 80–90%. Furthermore, Exci-Cas9 enabled cell- or tissue-specific genome editing by expressing Cre from a cell- or tissue-specific promoter. We believe that Exci-Cas9 developed in this study is useful not only for resolving the persistent expression of Cas9, which has been a problem in genome editing, but also for eliminating long-term DNA viruses such as human papilloma virus.
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