[Progress in application of Bletilla striata polysaccharide in novel drug delivery systems and biomaterials].

As the main active ingredient of the orchidaceous herb Bletilla striata, B. striata polysaccharide(BSP) has pharmacological activities such as promoting coagulation, anti-inflammation, anti-oxidation, promoting wound healing, anti-tumor, and immunomodulation, and is biodegradable and non-toxic. Additionally, it has the material properties of suspension thickening, film-forming adhesion, coating and solubilizing, targeting and slow releasing, effect-enhancing and toxicity-reducing, etc., playing the role of unification of medicines and excipients. Therefore, BSP has a wide application prospect in the fields of drug delivery system and trauma repair. This paper reviews the research progress of BSP application in new drug delivery systems and biomaterials based on the related li-terature in recent years, with the aim of providing reference for the further research and application of BSP.

[Population structure and quantitative dynamics of Stellera chamaejasme in degraded typical steppe]. / é€€åŒ–å ¸åž‹è‰åŽŸç‹¼æ¯’ç§ç¾¤ç»“æž„ä¸Žæ•°é‡åŠ¨æ€.

Stellera chamaejasme is one of most common poisonous plant species in degraded grasslands of China. S. chamaejasme could dominate the community in some severely degraded grasslands, which is a serious threat to the sustainable development of animal husbandry in natural grasslands. In this study, S. chamaejasme population was divided into 10 age classes according to the number of branches. We investigated the age structure of S. chamaejasme population and population dynamic indices, and quantified the survival status of S. chamaejasme population by compiling a static life table, drawing a survival curve, conducting survival analysis. The age structure of S. chamaejasme population in the study area was growth type. The number of individuals in Ⅰ age class was sufficient but with relatively low survival rate. The population structure of S. chamaejasme was fitted the growing type. The development process of population was fluctuating. The number of individuals would drop sharply in Ⅱ and Ⅷ, indicating that these two age classes were the bottleneck period in the development of S. chamaejasme population. The survival curves of S. chamaejasme population was the Deevey-Ⅱ type. The results of survival analysis showed that the population had a sharp decrease in the early stage and was stable in the later stage, which was because the value of fx and λx of S. chamaejasme in Ⅰ or Ⅱ age class were the highest. In conclusion, sufficient young individuals (Ⅰ) was the basis for the expansion of S. chamaejasme population in the degraded typical steppe. The low transformation rate of young individuals to adults might be one of the reasons explaining why S. chamaejasme population could not expand rapidly in the early stage of grassland degradation. Therefore, it was suggested to intervene early when the number of S. chamaejasme was limited.