The Microstructure,Antibacterial and Antitumor Activities of Chitosan Oligosaccharides and Derivatives

Chitosan obtained from abundant marine resources has been proven to have a variety of biological activities. However, due to its poor water solubility, chitosan application is limited, and the degradation products of chitosan oligosaccharides are better than chitosan regarding performance. Chitosan oligosaccharides have two kinds of active groups, amino and hydroxyl groups, which can form a variety of derivatives, and the properties of these derivatives can be further improved. In this review, the key structures of chitosan oligosaccharides and recent studies on chitosan oligosaccharide derivatives, including their synthesis methods, are described. Finally, the antimicrobial and antitumor applications of chitosan oligosaccharides and their derivatives are discussed.     

贯彻以人为本的思想,创造良好的人居环境

提出在城市的绿化、美化建设中,只有从当地的实际出发,坚持“以人为本”,追求人与自然的和谐发展,才能为市民营造舒适和宜人的环境,才能真正实现创建和谐型社会的目标。     

生物矿化合成木材-SiO2复合材料的XPS分析

利用生物矿化原理制备木材—SiO2复合材料,采用溶胶—凝胶法制备硅溶液,用不同质量分数的硅溶液对喜树进行浇灌和滴注试验。经过1个月的试验得到样品,利用光电子能谱仪(XPS)分析素材和SiO2复合材样品中硅、碳的质量比,证实喜树成功吸收硅元素,并且存活,植株根茎附近生长较好,枝叶较多,顶部附近枝叶较少。比较浇灌、滴注2种方法:①浇灌过程相对简单,树木对硅的吸收相对较少;使用质量分数越高的药品对树木进行浇灌,树木对硅的吸收越好。②滴注过程相对复杂,树木对硅的吸收相对较多;使用质量分数越高的药品进行滴注,树木对硅的吸收越好;但吸收不均匀,呈滴注孔口附近往树梢方向减少趋势。前期研究结果表明,对树木进行浇灌和滴注,药品硅的质量分数过高树木会死亡,过低则达不到要求,因此,最佳质量分数配制还有待于进一步研究确定。总的来说,利用生物矿化原理模拟木材—SiO复合材是可行的。     

膜荚黄芪根水浸液对4种作物种子萌发及幼苗生长的影响

通过室内生物测定法,研究了黄芪根水浸液对4种作物种子萌发及幼苗生长的化感影响。结果表明,黄芪根水浸液对4种作物种子萌发及幼苗生长均有明显的化感作用,其中根受到的化感抑制大于地上部分,种子萌发阶段受到的化感抑制大于幼苗生长阶段。不同受体的发芽势、最长根长和根冠比受到的化感抑制最强。4种作物的化感敏感性为小麦>板蓝根>大麦>大豆。因此,选择与黄芪轮作、套作的作物时,优先选择大豆和大麦,其次为板蓝根。     

辽河干流河岸带植物及微生物多样性研究

为明确辽河保护区河岸带生物多样性恢复现状以促进河岸带生态系统的健康管理,本研究通过植被现场调查和土壤微生物高通量测序分析,对辽河干流23个采样点的植物多样性和微生物多样性进行测定,结果表明:辽河干流23个采样点的植被Shannon-Weiner多样性指数平均为1.227,平均植被覆盖率达到74.19%;河岸带土壤微生物Shannon-Weiner多样性指数平均为9.55;其优势度大于1%的细菌属于11个门、32个纲、40个属;人类活动干扰、放牧情况以及土地利用类型是影响河岸带植物和微生物多样性的关键因子。目前辽河保护区河岸带生物多样性恢复状态较好,但日渐增多的人类活动对河岸带生物多样性的恢复产生不利影响,因此建议尽量减少封育区内的人类活动、放牧情况等,以加快辽河保护区河岸带植物及土壤微生物多样性的恢复进程。     

Potential of Plant Proteins Digested In Silico by Gastrointestinal Enzymes as Nutritional Supplement for COVID-19 Patients

Plant Foods for Human Nutrition - Currently, no specific drug and vaccine are available for the new coronavirus SARS-CoV-2, and nutritional supplementation should be helpful. This study tried to...     

Analysis of the water balance and the nitrogen and phosphorus runoff pollution of a paddy field in situ in the Taihu Lake basin

Paddy and Water Environment - Nitrogen (N) and phosphorus (P) runoff loads of paddy fields in situ under conventional water and fertilizer management measures caused severe water pollution in the...     

人参/西洋参枯叶病缓解实验

通过各供试药剂在西洋参枯叶病上的使用,验证各供试药剂对西洋参枯叶病的缓解作用。结果表明,参多乐450倍液+益微450倍液对西洋参枯叶病缓解效果突出,在一定程度上解决了枯叶病给西洋参带来的危害。且该配方在人参上同样适用。