茶儿茶素类体内代谢动力学研究进展

儿茶素类作为绿茶的主要成分,具有广泛的生物学行为和药理功能.众多研究表明虽然儿荼素类在体外细胞体系中呈现较强的生物学活性,但其体内与体外表现不尽相同.本文对儿茶素类在生物体内的吸收、分布、代谢产物等进行综述,并对儿荼素类体内研究的前景进行展望,以期为儿荼素类作为药物或辅助药物的开发提供理论依据.     

Studies of cocoa tea, a wild tea tree containing theobromine

Camellia ptilophylla Chang is a wild tea tree containing theobromine and is caffeine-flee. Lots of researches have been conducted for its domestication since it was discovered to contain theobromine in its shoots. First, its pharmacological and physiological effects have been studied, demonstrating that it can be used as a new resource of tea as daily and healthy beverage. Cocoa tea differs from traditional tea in that it does not excite the nervous system. Second, various ways of propagation have been investigated, and sexless cutting has been the method adopted currently. Third, through selection and breeding, plantation of cocoa tea can be set up to cultivate new varieties, and cocoa tea of different flavors such as green cocoa tea, oolong cocoa tea, and black cocoa tea can be processed. Thus, cocoa tea will become a choice in the tea market.     

A novel privacy protection of permissioned blockchains with conditionally anonymous ring signature

With the rapid development of permissioned blockchains, the problem of privacy leakage within permissioned blockchains is increasingly serious. In this paper, for the privacy problem in permissioned blockchains, a novel privacy protection method has been put forward. In this novel method, the ring signature is used to protect the privacy of the user in permissioned blockchains. On the other hand, the unconditional anonymity of ring signature may be abused maliciously by the adversary. Conditional anonymity is considered to improve the ring signature. Therefore, based on conditionally anonymous ring signature, permissioned blockchains privacy protection scheme has also been laid down. Furthermore, the effects of smart contract for transaction flows are considered. The asynchronous signing transaction process is proposed. The security of the scheme has been formally reduced to the Discrete Logarithm assumption. The comparison with the state-of-the-art and simulation experiment have also demonstrated that the proposed scheme is efficient and practical.