Plug Seedling Production of Short Vine Type Sweet Potato Variety‘Ganshu No.2’

This study was conducted to investigate the effects of different vine cuttings and provide a fast method for production of high-quality sweet potato seedlings.With short vine type‘Ganshu No.2'as an experiment material,biological characteristics of sweet potato seedlings were investigated by setting three vine sections( the ingle-node section,dual-node section and three-node top bud section) using three kinds of substrates( red soil,leaf mould and pond sludge).The results showed that the dual-node vine section plus leaf mould treatment sprouted earliest( 3 d) with the highest survival rate( 86.6%),root number( 9.2 roots) and the longest root length( 5.9 cm),compared with other treatments.Therefore,dual-node vine section plus leaf mould plug seedling raising has the characteristics of short sprouting time,high survival rate and low cost.The method could provide seedlings in a short period( 20 d),improves sweet potato propagation coefficient and is worth extending and applying.

Bone physiological microenvironment and healing mechanism:Basis for future bone-tissue engineering scaffolds

Bone-tissue defects affect millions of people worldwide.Despite being common treatment approaches,autologous and allogeneic bone grafting have not achieved the ideal therapeutic effect.This has prompted researchers to explore novel bone-regeneration methods.In recent decades,the development of bone tissue engineering(BTE)scaffolds has been leading the forefront of this field.As researchers have provided deep insights into bone physiology and the bone-healing mechanism,various biomimicking and bioinspired BTE scaffolds have been reported.Now it is necessary to review the progress of natural bone physiology and bone healing mechanism,which will provide more valuable enlightenments for researchers in this field.This work details the physiological microenvironment of the natural bone tissue,bone-healing process,and various biomolecules involved therein.Next,according to the bone physiological microenvironment and the delivery of bioactive factors based on the bone-healing mechanism,it elaborates the biomimetic design of a scaffold,highlighting the designing of BTE scaffolds according to bone biology and providing the rationale for designing next-generation BTE scaffolds that conform to natural bone healing and regeneration.

Polydopamine-mediated graphene oxide and nanohydroxyapatite-incorporated conductive scaffold with an immunomodulatory ability accelerates periodontal bone regeneration in diabetes

Regenerating periodontal bone tissues in the aggravated inflammatory periodontal microenvironment under diabetic conditions is a great challenge.Here,a polydopamine-mediated graphene oxide(PGO)and hydroxyapatite nanoparticle(PHA)-incorporated conductive alginate/gelatin(AG)scaffold is developed to accelerate periodontal bone regeneration by modulating the diabetic inflammatory microenvironment.PHA confers the scaffold with osteoinductivity and PGO provides a conductive pathway for the scaffold.The conductive scaffold promotes bone regeneration by transferring endogenous electrical signals to cells and activating Ca2+channels.Moreover,the scaffold with polydopamine-mediated nanomaterials has a reactive oxygen species(ROS)-scavenging ability and anti-inflammatory activity.It also exhibits an immunomodulatory ability that suppresses M1 macrophage polarization and activates M2 macrophages to secrete osteogenesis-related cytokines by mediating glycolytic and RhoA/ROCK pathways in macrophages.The scaffold induces excellent bone regeneration in periodontal bone defects of diabetic rats because of the synergistic effects of good conductive,ROS-scavenging,anti-inflammatory,and immunomodulatory abilities.This study provides fundamental insights into the synergistical effects of conductivity,osteoinductivity,and immunomodulatory abilities on bone regeneration and offers a novel strategy to design immunomodulatory biomaterials for treatment of immune-related diseases and tissue regeneration.

二芳基乙烯类化合物的光致关环及重排过程的理论研究

二芳基乙烯的光环化反应在分子开关和有机合成领域有重要应用.本文选取Lovo等合成的三个二芳基乙烯类化合物(2-苯基-3-[3-2,5-二甲基噻吩]-2-环戊烯酮、2-苯基-3-[2-3,5-二甲基噻吩]-2-环戊烯酮及3-苯基-2-[3-2,5-二甲基噻吩]-2-环戊烯酮),采用(TD)DFT、CASSCF和CASPT2方法对三个化合物的光环化反应及重排过程进行研究,以探索羰基官能团及杂原子位置的不同对反应机理的影响以及光环化反应对后续重排过程的影响.研究结果表明:二芳基乙烯光环化反应为三个电子态、两类圆锥交叉参与的过程.在三个化合物中,噻吩中S原子位于分子外侧时,光环化产物能量明显高于S位于内侧的情形,关环过程最为困难;当S原子同处内侧时,羰基靠近噻吩一侧较靠近苯环一侧的激发态势能曲线平缓,反应驱动力较小,光环化较为困难.此外,通过重排反应生成的产物以及过渡态和产物能量的分析,发现后续重排过程与光环化步骤发生的难易程度存在一致性,光环化反应越容易发生,重排反应也相应的越容易发生,因此得到的产物产率也越高.

Estimating the effect of urease inhibitor on rice yield based on NDVI at key growth stages

The effect of the urease inhibitor,N-(n-butyl)thiophosphoric triamide(NBPT)at a range of application rates on rice production was examined in a field experiment at Jinxian County,Jiangxi Province,China.The normalized difference vegetation index(NDVI)was measured at key growth stages in both early and late rice.The results showed that the grain yield increased significantly when urea was applied with NBPT,with the highest yield observed at 1.00%NBPT(wt/wt).NDVI differed with the growth stage of rice;it remained steady from the heading to the filling stage.Rice yield could be predicted from the NDVI taken at key rice growing stages,with R^(2) ranging from 0.34 to 0.69 in early rice and 0.49 to 0.70 in late rice.The validation test showed that RMSE(t·hm^(–2))values were 0.77 and 0.87 in early and late rice,respectively.Therefore,it was feasible to estimate rice yield for different amounts of urease inhibitor using NDVI.