ABSTRACT
This paper develops an effective identification method to discriminate genetically modified (GM) and non-GM organisms. The method is proposed based on terahertz (THz) spectroscopy and support vector machines optimized by Cuckoo Search algorithm (CS-SVM). In this study, the THz spectra of three GM and non-GM soya seed samples were obtained by using terahertz time-domain spectroscopy (THz-TDS) system between 0.2 and 1.2 THz. Then, the SVM model is employed to distinguish GM and non-GM soya seeds, in which the two crucial parameters, including the penalty factor and kernel parameter, are optimized by CS algorithm. The experimental results show that THz spectroscopy combined with CS-SVM can provide a rapid, reliable and non-invasive method for GMOs and non-GMOs discrimination.
ABSTRACT
OBJECTIVE: To study the chemical constituents of Humulus scandens. METHODS: The compounds were isolated by column chromatography on silica gel and Sephadex LH-20. The structures were identified by means of IR, 1H-NMR,13C-NMR and MS analyses. RESULTS: Seven compounds were isolated and identified as friedelanone (I), cis-asarone (II), epifriedelanol (III), stigmasta-4-ene-3,6-dione (IV), gamma-sitosterol (V), n-hexadecanoic acid (VI), and linoleic acid (VII), respectively. CONCLUSION: All compounds are isolated from this species for the first time and compounds I - V are obtained from this genus for the first time.
