ABSTRACT
With the escalation of plastic bans and restrictions, bio-based plastics, represented by polylactic acid (PLA), have become a major alternative to traditional plastics in the current market and are unanimously regarded as having potential for development. However, there are still several misconceptions about bio-based plastics, whose complete degradation requires specific composting conditions. Bio-based plastics might be slow to degrade when it is released into the natural environment. They might also be harmful to humans, biodiversity and ecosystem function as traditional petroleum-based plastics do. In recent years, with the increasing production capacity and market size of PLA plastics in China, there is an urgent need to investigate and further strengthen the management of the life cycle of PLA and other bio-based plastics. In particular, the in-situ biodegradability and recycling of hard-to-recycle bio-based plastics in the ecological environment should be focused. This review introduces the characteristics, synthesis and commercialization of PLA plastics, summarizes the current research progress of microbial and enzymatic degradation of PLA plastics, and discusses their biodegradation mechanisms. Moreover, two bio-disposal methods against PLA plastic waste, including microbial in-situ treatment and enzymatic closed-loop recycling, are proposed. At last, the prospects and trends for the development of PLA plastics are presented.
Subject(s)
Humans , Ecosystem , Biodegradable Plastics , Polyesters , Biodegradation, EnvironmentalABSTRACT
Botulinum toxin type A (BTX A) has gain widespread use in various neurological conditions, characterized by safe injection and less side-effect. This review will examine the current research of BTX A in the following aspects: mechanism, location, dose and outcome, which manifests the safety and efficacy data of BTX A injection treatment to the symptoms of Parkinson disease, including refractory tremor, focal dystonia, loss of postural reflexes, sialorrhea, gastrointestinal symptoms and depressive disorder.
ABSTRACT
Objective@#To analyze the interaction of fat mass (FM) and fat free mass (FFM) on the aggregation of cardiovascular disease risk factors (CVRFs) among children and adolescents in Yinchuan City, China, so as to provide scientific basis for the prevention of CVRFs and cardiovascular disease in children and adolescents.@*Methods@#A total of 1 822 children and adolescents aged 12 to 18 years in Yinchuan City were randomly selected for questionnaire survey, physical examination, body composition assessment and laboratory tests, through a cluster sampling method from 2017 to 2020. Binary Logistic regression was used to analyze the relationship between FM, FFM and the aggregation of CVRFs, and their interaction was analyzed.@*Results@#After adjusting for sex and age, the risk of having CVRFs aggregation ≥1 in high FM and low FFM group and high FM and high FFM group was 2.01(95% CI =1.46-2.77) and 3.64(95% CI =2.66-4.98) times higher than that in low FM and low FFM group, and the risk of having CVRFs aggregation ≥2 was 1.67(95% CI =1.06-2.63) and 4.20 (95% CI =2.76-6.38) times, respectively( P <0.05). There was a multiplicative interaction between FM and FFM, which increased the risk of CVRFs aggregration ≥1 and ≥2. The adjusted OR and 95% CI were 1.58(1.04-2.40) and 1.95(1.12-3.42), respectively( P <0.05).@*Conclusion@#The results indicated the additive and multiplicative interactions between high levels of fat mass and fat free mass on the aggregation of cardiovascular risk factors, which increased the risk of aggregation of cardiovascular risk factors.