Predictive value of serum cystatin C for risk of mortality in severe and critically ill patients with COVID-19

BACKGROUND The outbreak of coronavirus disease 2019(COVID-19)has rapidly evolved into a global pandemic.COVID-19 is clinically categorized into mild,moderate,severe,and critical illness.Acute kidney injury is an independent risk factor for poor prognosis in patients with.Serum cystatin C(s Cys C)is considered a more sensitive biomarker for early renal insufficiency than conventional indicators of renal function.Early detection of risk factors that affect the prognosis of severe and critically ill patients while using active and effective treatment measures is very important and can effectively reduce the potential mortality rate.AIM To determine the predictive value of s Cys C for the prognosis of patients with COVID-19.METHODS The clinical data of 101 severe and critically ill patients with COVID-19 at a designated hospital in Wuhan,Hubei Province,China were analyzed retrospectively.According to the clinical outcome,the patients were divided into a discharge group(64 cases)and a death group(37 cases).The general information,underlying diseases,and laboratory examination indexes of the two groups were compared.Multivariate Cox regression was used to explore the relationship between s Cys C and prognosis.The receiver operating characteristic(ROC)curve was used to demonstrate the sensitivity and specificity of s Cys C and its optimal cut-off value for predicting death.RESULTS There were significant differences in age,s Cys C,creatinine,C-reactive protein,serum albumin,creatine kinase-MB,alkaline phosphatase,lactate dehydrogenase,neutrophil count,and lymphocyte count between the two groups(P<0.001).Multivariate logistic regression analysis showed that s Cys C was an independent risk factor for death in patients with COVID-19(Odds ratio=1.812,95%confidence interval[CI]:1.300-2.527,P<0.001).The area under the ROC curve was 0.755(95%CI:1.300-2.527),the cut-off value was 0.80,the specificity was 0.562,and the sensitivity was 0.865.CONCLUSION s Cys C is an independent risk factor for death in patients with COVID-19.Patients with a s Cys C level of 0.80 mg/L or greater are at a high risk of death.

Effect of methylprednisolone in severe and critical COVID-19:Analysis of 102 cases

BACKGROUND The coronavirus disease 2019(COVID-19)outbreak has brought great challenges to public health.Aggravation of COVID-19 is closely related to the secondary systemic inflammatory response.Glucocorticoids are used to control severe diseases caused by the cytokine storm,owing to their anti-inflammatory effects.However,glucocorticoids are a double-edged sword,as the use of large doses has the potential risk of secondary infection and long-term serious complications,and may prolong virus clearance time.Nonetheless,the risks and benefits of glucocorticoid adjuvant therapy for COVID-19 are inconclusive.AIM To determine the effect of methylprednisolone in severe and critically ill patients with COVID-19.METHODS This single-center retrospective study included 102 adult COVID-19 patients admitted to a ward of a designated hospital in Wuhan,Hubei Province from January to March 2020.All patients received general symptomatic treatment and organ function support,and were given different respiratory support measures according to their conditions.In case of deterioration,considering the hyperinflammatory state of the patients,methylprednisolone was intravenously administered at 0.75-1.5 mg/kg/d,usually for less than 14 d.Patient vital signs and oxygenation were closely monitored,in combination with imaging and routine blood tests such as C-reactive protein,biochemical indicators(liver and kidney function,myocardial enzymes,electrolytes,etc.),and coagulation function.Patient clinical outcomes were discharge or death.RESULTS A total of 102 severe and critically ill COVID-19 patients were included in this study.They were divided into treatment(69,67.6%)and control groups(33,32.4%)according to methylprednisolone use.Comparison of baseline data between the two groups showed that the treatment group patients had higher aspartic acid aminotransferase,globulin,hydroxybutyrate dehydrogenase,and lactate dehydrogenase.There was no significant difference in other baseline data between the two groups.With regard to prognosis,29(78.4%)patients in the treatment group died as opposed to 40(61.5%)in the control group.The mortality was higher in the treatment group than in the control group;however,according to the log-rank test and the Kaplan–Meier survival curve,the difference in mortality between both groups was insignificant(P=0.655).The COX regression equation was used to correct the variables with differences,and the results showed that methylprednisolone treatment did not improve prognosis.CONCLUSION Methylprednisolone treatment does not improve prognosis in severe and critical COVID-19 patients.

Sr阳离子和O阴离子空位缺陷调控工程提升钙钛矿Sr_(x)VO_(3-δ)储锂性能

钙钛矿结构氧化物的空位缺陷调控工程在催化和太阳能电池等领域被广泛研究应用,本文进一步拓展了钙钛矿材料空位缺陷工程在储能领域的应用.使用钙钛矿Sr_(x)VO_(3-δ)材料为研究材料,通过调控溶胶燃烧过程中Sr/V化学计量比和还原温度,精确控制样品中的Sr阳离子和O阴离子的空位浓度,并且保持了Sr_(x)VO_(3-δ)材料的钙钛矿结构.电化学研究结果表明,通过提高Sr阳离子和O阴离子空位缺陷浓度,Sr_(x)VO_(3-δ)电极比容量和倍率性能显著提升.其中,Sr空位缺陷的引入为锂离子提供了额外储锂位点和扩散通道,而O空位缺陷的引入则显著提升了Sr_(x)VO_(3-δ)电极的电导率和锂离子扩散系数.因此,空位缺陷工程为钙钛矿结构储能材料电化学性能的提升和设计提供了新思路.