Effect of Cr_(2)O_(3) nanosheet insertion on the deuterium permeation behavior of a Cr-Zr-O coating

In this study,a Cr_(2)O_(3) nanosheet(Cr_(2)O_(3) NS)inserted Cr-Zr-O coating was developed as a hydrogen isotope permeation barrier.The Cr_(2)O_(3) NSs,fabricated by rapid heat treatment,were amorphous with a thickness of only several nanometers.These Cr_(2)O_(3) NSs were then incorporated into a Cr-Zr-O multi-metal oxide composite coating via a dip-coating method to form a coating.The effect of the Cr_(2)O_(3) NS concentration on the morphology,microstructure and deuterium permeation resistance of the coating was studied.With the addition of 1.0 g 1^(-1)Cr_(2)O_(3) NSs,compared with the Cr-Zr-O coating without NSs,the permeation reduction factor of the resultant coating was enhanced from 249℃to 575℃ at 500℃.The coating,with a thickness of nearly 193 nm,achieved a comparable deuterium resistance that was above two orders of magnitude higher than the steel substrate.The results show that ceramic NSs can serve as effective fillers for enhancing the coating performance when functioning as a hydrogen isotope barrier.

Combination therapy of thiamine,vitamin C and hydrocortisone in treating patients with sepsis and septic shock:a meta-analysis and trial sequential analysis

Background:The objective of this study was to evaluate the clinical efficacy of thiamine and vitamin C with or without hydrocortisone coadministration on the treatment of sepsis and septic shock.Methods:MEDLINE,EMBASE and CENTRAL databases were searched for randomized controlled trials(RCTs)that made a comparative study between the combination therapy of vitamin C and thiamine with or without hydrocortisone and the administration of placebo in patients with sepsis or septic shock.Two reviewers independently performed study selection,data extraction and quality assessment.Both short-term mortality and change in the sequential organ failure assessment(SOFA)score from baseline(delta SOFA)were set as the primary outcomes.Secondary endpoints included intensive care unit(ICU)mortality,new onset of acute kidney injury,total adverse events,ICU and hospital length of stay,duration of vasopressor usage and ventilator-free days.Meanwhile,trial sequential analysis was conducted for primary outcomes.Results:Eight RCTs with 1428 patients were included in the current study.The results showed no significant reduction of short-term mortality in sepsis and septic shock patients who received combination therapy of vitamin C and thiamine with or without hydrocortisone compared to those with placebo{risk ratio(RR),1.02[95%confidence interval(CI),0.87 to 1.20],p=0.81,I2=0%;risk difference(RD),0[95%CI,−0.04 to 0.05]}.Nevertheless,the combination therapy was associated with significant reduction in SOFA score[mean difference(MD),−0.63,(95%CI,−0.96 to−0.29,p<0.001,I^(2)=0%]and vasopressors duration(MD,−22.11[95%CI,−30.46 to−13.77],p<0.001,I2=6%).Additionally,there were no statistical differences in the pooled estimate for other outcomes.Conclusions:In the current meta-analysis,the combination therapy of vitamin C and thiamine,with or without hydrocortisone had no impact on short-term mortality when compared with placebo,but was associated with significant reduction in SOFA score among patients with sepsis and septic shock.

Layer-structured Cr/Cr_(x)N coating via electroplating-based nitridation achieving high deuterium resistance as the hydrogen permeation barrier

Hydrogen isotope permeation through structural materials is a key issue for developing nuclear fusion energy,which will cause fuel loss and radioactive pollution.Developing ceramic coatings with high thermal shock and hydrogen resistance is an effective strategy to solve this issue.In this work,a layer-structured Cr/Cr_(x)N coating was successfully fabricated by a facile electroplatingbased nitridation technique,which is easy,facile,and applicable to coating complex-shaped substrates.The Cr/Cr_(x)N coating,composed of a bottom Fe/Cr interdiffusion zone,a middle Cr layer,and a top Cr_(x)N layer,exhibits high bonding strength,high anti-thermal-shock ability,and high deuterium permeation resistance.Its bonding strength achieves 43.6 MPa.The Cr/Cr_(x)N coating remains intact even after suffering 300 thermal shock cycles under a 600℃–water condition.Through optimizing the nitridation temperature,the Cr/Cr_(x)N coating achieves a deuterium permeation reduction factor(PRF)as high as 3599 at 500℃.Considering its scalable fabrication technique and considerable properties,the developed Cr/Cr_(x)N coating may serve as a novel high-performance hydrogen permeation barrier in various fields.