Rapid online analysis of trace elements in steel using a mobile fiber-optic laser-induced breakdown spectroscopy system

A mobile fiber-optic laser-induced breakdown spectrometer(FO-LIBS) prototype was developed to rapidly detect a large quantity of steel material online and quantitatively analyze the trace elements in a large-diameter steel tube.Twenty-four standard samples and a polynomial fitting method were used to establish calibration curve models.The R^2 factors of the calibration curves were all above 0.99,except for Cu,indicating the elements’ strong self-absorption effect.Five special steel materials were rapidly detected in the steel mill.The average absolute errors of Mn,Cr,Ni,V,Cu,and Mo in the special steel materials were 0.039,0.440,0.033,0.057,0.003,and0.07 wt%,respectively,and their average relative errors fluctuated from 2.9% to 15.7%.The results demonstrated that the performance of this mobile FO-LIBS prototype can be compared with that of most conventional LIBS systems,but the more robust and flexible characteristics of the FO-LIBS prototype provide a feasible approach for promoting LIBS from the laboratory to the industry.

Effect of HDAC-6 on PD cell induced by lactacystin

Objective:To explore the effects of histone deacetylase 6(HDAC-6) on the PD cell model induced by proteasome inhibitor lactacystin.Methods:Human neuroblastoma SK-N-SH cells were cultured.The wild type pcDNA3.1-alpha-synuclein eukaryotic expression plasmid was transferred into the cells which then were divided into control group,group L,group T and group T+L.The eells of group L were added with 5 umol/L lactacystin dissolved in dimethylsulfoxide(DMSO) to induce PD cell model with abnormal protein aggregation,the cells of control group were treated with 5 umol/L DMSO,the cells of group T were treated with 5 umol/L selective HDAC-6 inhibitor tubacin dissolved in DMSO,and the cells of group T+L were treated with 5 umol/L lactaeystin and 10 umol/L tubacin dissolved in DMSO.The expression levels of alpha-synuclein oligomers,HSP-27 and HSP-70 were detected by Western blot and the cell survival rate of all the groups was detected by MTT colorimetric assay,and compared 24 h after the cells were treated.Results:The expression levels of alpha-synuclein oligomers,HSP-27 and HSP-70 of the cells of group L were significantly higher than the control group,and the cell survival rate was significantly lower(P<0.05);the expression level of alpha-synuclein oligomers of the cells of group T+L was significantly higher than group L,but the expression level of HSP-27 and HSP-70 were significantly lower,and so as the cell survival rate(P<0.05);the differences of the expression level of alpha-synuclein oligomers,HSP-27 and HSP-70 and the cell survival rate of the cells of group T and the control group were not statistically significant(P>0.05).Conclusions:The expression level of alphasynuclein oligomers can be improved and the cell survival rate can be reduced by the PD cell model induced by lactacystin and treated with selective HDAC-6 inhibitor tubacin,which means that alpha-synuclein oligomers of the PD cell model induced by lactacystin can be inhibited and the cell survival rate can be improved by HDAC-6,and the mechanism may be related to the increased of HSP-27 and HSP-70.