As one of the largest global public health problems, cancer greatly endangers human health. Researchers have been committed to discovering anticancer drugs with high efficiency and low toxicity. Shogaol, a kind of ing...As one of the largest global public health problems, cancer greatly endangers human health. Researchers have been committed to discovering anticancer drugs with high efficiency and low toxicity. Shogaol, a kind of ingredient from ginger with high anti-tumor activity, has attracted our attention. This study was an investigation on the composition and structure-activity relationship of different analogues of shogaol, with the purpose to screen for shogaol compounds which had higher anti-tumor activity and could be easily synthesized. We chose zingerone as the starting material to synthesize shogaol through four-step reactions without protective group, as a result, 31 analogues were synthesized for anti-tumor activity detect. The biological test results showed that： the missing of the unsaturated ketone and the phenolic hydroxyl group reduced the anti-tumor activity of shogaol; the site of phenolic hydroxyl had no significant influence on the anti-tumor activity, the indicating that the larger the steric hindrance of substituent, the lower the activity, but the higher the activity of cyclobutyl substituted derivatives.展开更多
Due to the uncertainty of the factors that influence the network service time and other characters of college student, Bayesian Network is used to model this kind of system. Different algorithms are used for learning ...Due to the uncertainty of the factors that influence the network service time and other characters of college student, Bayesian Network is used to model this kind of system. Different algorithms are used for learning Bayesian Networks in order to compare several models. It is suggested that researchers can use Bayesian Networks to explore the potential relationship between variables of complex social problems. The result indicates that learning target and family closeness degree are the key variables which influenced college student＇ s network service time. Origin of student and family economy didn＇ t influence college student＇ s network service time directly. Schools and community should strengthen the education of college students life planning and communication with parents.展开更多
文摘As one of the largest global public health problems, cancer greatly endangers human health. Researchers have been committed to discovering anticancer drugs with high efficiency and low toxicity. Shogaol, a kind of ingredient from ginger with high anti-tumor activity, has attracted our attention. This study was an investigation on the composition and structure-activity relationship of different analogues of shogaol, with the purpose to screen for shogaol compounds which had higher anti-tumor activity and could be easily synthesized. We chose zingerone as the starting material to synthesize shogaol through four-step reactions without protective group, as a result, 31 analogues were synthesized for anti-tumor activity detect. The biological test results showed that： the missing of the unsaturated ketone and the phenolic hydroxyl group reduced the anti-tumor activity of shogaol; the site of phenolic hydroxyl had no significant influence on the anti-tumor activity, the indicating that the larger the steric hindrance of substituent, the lower the activity, but the higher the activity of cyclobutyl substituted derivatives.
文摘Due to the uncertainty of the factors that influence the network service time and other characters of college student, Bayesian Network is used to model this kind of system. Different algorithms are used for learning Bayesian Networks in order to compare several models. It is suggested that researchers can use Bayesian Networks to explore the potential relationship between variables of complex social problems. The result indicates that learning target and family closeness degree are the key variables which influenced college student＇ s network service time. Origin of student and family economy didn＇ t influence college student＇ s network service time directly. Schools and community should strengthen the education of college students life planning and communication with parents.
