[Recent progress in the study of reduction-sensitive drug carriers].

With rapid and efficient drug release, few side effects and excellent biodegradable properties, the reduction-sensitive carriers is not only the new hot point in the field of pharmaceutical research, but also the most promising intelligent drug carrier on clinical application. This paper reviews the latest research of reduction-sensitive drug and gene carriers, including the mechanisms of drug release and the synthesis of the reduction-sensitive conjugates, reduction-sensitive nano polymer micelles, nano vesicles, nano hollow microspheres, nano liposomes, as well as the characteristics and advantages of various kinds of carrier system. It will provide a theoretical basis for its further application.

Analysis of dental caries and the impact factors of caries in children aged 3-5 years old in Changdu, Xizang.

OBJECTIVES: To investigate caries status and its impact factors in preschool children in plateau and to provide reference for caries prevention in highlands. METHODS: Examination of caries was performed on 1 597 children aged 3-5 years old in 11 kindergartens in Changdu, Xizang, in accordance with the 4th National Oral Health Survey standards and methods. Their parents were surveyed with the questionnaire regarding oral hygiene habit and consciousness about oral health and related factors. All the data were collected and analyzed. RESULTS: The prevalence of caries among children aged 3-5 years old in Changdu was 52.85%, with dmft index of 2.44. The caries rate and dmft of children aged 3 years old were lower than those of children aged 4 and 5 years old (P<0.05). No significant difference was observed in the caries rate between males and females (P>0.05). Single-factor analysis showed that the frequency of brushing teeth more than twice a day, low frequency of eating sweets, high frequency of drinking butter tea, and regular oral examination can reduce the rate of caries (P<0.05). Multivariate logistic analysis showed that the frequency of eating sweets, drinking butter tea, and oral examination are related impact factors of caries. CONCLUSIONS: The prevalence of ca-ries in children aged 3-5 years old in Changdu increases with aging. Good oral hygiene and eating habits and regular oral examination can reduce the rate of caries.