Neurophysiological, histological, and behavioral characterization of animal models of distraction spinal cord injury: a systematic review

Distraction spinal cord injury is caused by some degree of distraction or longitudinal tension on the spinal cord and commonly occurs in patients who undergo corrective operation for severe spinal deformity.With the increased degree and duration of distraction,spinal cord injuries become more serious in terms of their neurophysiology,histology,and behavior.Very few studies have been published on the specific characteristics of distraction spinal cord injury.In this study,we systematically review 22 related studies involving animal models of distraction spinal cord injury,focusing particularly on the neurophysiological,histological,and behavioral characteristics of this disease.In addition,we summarize the mechanisms underlying primary and secondary injuries caused by distraction spinal cord injury and clarify the effects of different degrees and durations of distraction on the primary injuries associated with spinal cord injury.We provide new concepts for the establishment of a model of distraction spinal cord injury and related basic research,and provide reference guidelines for the clinical diagnosis and treatment of this disease.

Complete biosynthesis of the phenylethanoid glycoside verbascoside

Verbascoside,which was first discovered in 1963,is a well-known phenylethanoid glycoside(PhG)that exhibits antioxidant,anti-inflammatory,antimicrobial,and neuroprotective activities and contributes to the therapeutic effects of many medicinal plants.However,the biosynthetic pathway of verbascoside remains to be fully elucidated.Here,we report the identification of two missing enzymes in the verbascoside biosynthesis pathway by transcriptome mining and in vitro enzymatic assays.Specifically,a BAHD acyltransferase(hydroxycinnamoyl-CoA:salidroside hydroxycinnamoyltransferase[SHCT])was shown to catalyze the regioselective acylation of salidroside to form osmanthuside A,and a CYP98 hydroxylase(osmanthuside B 3,30-hydroxylase[OBH])was shown to catalyze meta-hydroxylations of the p-coumaroyl and tyrosol moieties of osmanthuside B to complete the biosynthesis of verbascoside.Because SHCTs and OBHs are found in many Lamiales species that produce verbascoside,this pathway may be general.The findings from the study provide novel insights into the formation of caffeoyl and hydroxytyrosol moieties in natural product biosynthetic pathways.In addition,with the newly acquired enzymes,we achieved heterologous production of osmanthuside B,verbascoside,and ligupurpuroside B in Escherichia coli;this work lays a foundation for sustainable production of verbascoside and other PhGs in micro-organisms.

Functional group differentiation of isomeric solvents enables distinct zinc anode chemistry

Electrolytes hold the key to realizing reliable zinc(Zn)anodes.Divergent organic molecules have been proven effective in stabilizing Zn anodes;however,irrational comparisons exist due to the uncontrolled molecular weights and functional group amounts.In this work,two“isomeric molecules”:1,2-dimethoxyethane(DME)and 1-methoxy-2-propanol(PM),with identical molecular weights but different functional groups,have been studied as co-solvents in electrolytes,which have delivered distinct electrochemical performance.Experimental and simulative study indicates the dipole moment induced by the hydroxyl groups in PM(higher molecular polarity than ether groups in DME)reconstructs the space charge region,enhances the concentration of Zn^(2+)in the vicinity of Zn anodes,and in-situ derives different solid electrolyte interphase(SEI)models and electrode-electrolyte interfaces,resulting in exceptional cycling stability.Remarkably,the Zn||Cu cell with PM worked over 2000 cycles with high Coulombic efficiency(CE)of 99.7%.The Zn||Zn symmetric cell cycled over 2000 h at 1 mA·cm^(−2),and showed excellent stability at an ultrahigh current density of 10 mA·cm^(−2)and capacity of 20 mAh·cm^(−2)over 200 h(depth of discharge,DOD of 70%).The Zn||sodium vanadate pouch cell with a high mass loading of 6.3 mg·cm^(−2)and a high capacity of 24 mAh demonstrates superior cyclability after 570 h.This work can be a good starting point to provide reliable guidance on electrolyte design for practical aqueous Zn batteries.