目的建立一种基于近红外光谱技术快速测定甘薯多糖的方法。方法通过采集来自不同地区的74个甘薯及甘薯干的近红外光谱图,对异常样本进行剔除与回收后随机选择其中56个作为校正集,11个作为验证集。通过一阶导数、二阶导数、多元散射校正(...目的建立一种基于近红外光谱技术快速测定甘薯多糖的方法。方法通过采集来自不同地区的74个甘薯及甘薯干的近红外光谱图,对异常样本进行剔除与回收后随机选择其中56个作为校正集,11个作为验证集。通过一阶导数、二阶导数、多元散射校正(multiplicative signal correction,MSC)、标准正态变量变换(standard normal variate,SNV)等组合预处理方式对原始光谱进行处理,比较多元线性回归(stepwise multiple linear regression,SMLR)、主成分回归(principal component regression,PCR)和偏最小二乘法(partial least squares,PLS)3种方法建立的模型结果,进一步选择波段确定最佳甘薯多糖含量测定方法。结果PLS建立的模型整体精确度最佳,最优模型的预处理方式为一阶导数处理,该模型的最佳波段范围为4000~10000 cm^(-1),校正集均方根误差(root mean square error of calibration set,RMSEC)为0.50,校正集相关系数(correlation coefficient of calibration set,R;)为0.9683,验证集均方根误差(root mean square error of prediction set,RMSEP)为0.43,验证集相关系数(correlation coefficient of prediction set,R;)为0.9440,主成分数为8。结论通过近红外光谱技术结合偏最小二乘法建立甘薯多糖模型可作为甘薯多糖快速测定的可行性方法。展开更多
TiClx （x=2.17） was prepared by using titanium sponge to reduce the concentration of TiCl4 in a NaCl-KCl melt under negative pressure. The as-prepared NaCl-KCl-TiClx melt was employed as the electrolyte, and two para...TiClx （x=2.17） was prepared by using titanium sponge to reduce the concentration of TiCl4 in a NaCl-KCl melt under negative pressure. The as-prepared NaCl-KCl-TiClx melt was employed as the electrolyte, and two parallel crude titanium plates and one high-purity titanium plate were used as the anode and cathode, respectively. A series of electrochemical tests were performed to investigate the influence of electrolytic parameters on the current efficiency and quality of cathodic products. The results indicated that the quality of cathodic products was related to the current efficiency, which is significantly dependent on the current density and the initial concentration of titanium ions. The significance of this study is the attainment of high-purity titanium with a low oxygen content of 30× 10^-6.展开更多
Background:The early identification of heart failure(HF)risk may favorably affect outcomes,and the combination of multiple biomarkers may provide a more comprehensive and valuable means for improving the risk of strat...Background:The early identification of heart failure(HF)risk may favorably affect outcomes,and the combination of multiple biomarkers may provide a more comprehensive and valuable means for improving the risk of stratification.This study was conducted to assess the importance of individual cardiac biomarkers creatine kinase MB isoenzyme(CK-MB),B-type natriuretic peptide(BNP),galectin-3(Gal-3)and soluble suppression of tumorigenicity-2(sST2)for HF diagnosis,and the predictive performance of the combination of these four biomarkers was analyzed using random forest algorithms.Methods:A total of 193 participants(80 patients with HF and 113 age-and gender-matched healthy controls)were included from June 2017 to December 2017.The correlation and regression analysis were conducted between cardiac biomarkers and echocardiographic parameters.The accuracy and importance of these predictor variables were assessed using random forest algorithms.Results:Patients with HF exhibited significantly higher levels of CK-MB,BNP,Gal-3,and sST2.BNP exhibited a good independent predictive capacity for HF(AUC 0.956).However,CK-MB,sST2,and Gal-3 exhibited a modest diagnostic performance for HF,with an AUC of 0.709,0.711,and 0.777,respectively.BNP was the most important variable,with a remarkably higher mean decrease accuracy and Gini.Furthermore,there was a general increase in predictive performance using the multi-marker model,and the sensitivity,specificity was 91.5%and 96.7%,respectively.Conclusion:The random forest algorithm provides a robust method to assess the accuracy and importance of predictor variables.The combination of CK-MB,BNP,Gal-3,and sST2 achieves improvement in prediction accuracy for HF.展开更多
The investigation of silicothermic reduction of CaO·MgO was carried out using a self-developed thermogravimetric analysis(TGA)instrument under vacuum and high temperature conditions.The TG data of pellets prepare...The investigation of silicothermic reduction of CaO·MgO was carried out using a self-developed thermogravimetric analysis(TGA)instrument under vacuum and high temperature conditions.The TG data of pellets prepared with calcined dolomite,ferrosilicon and fluorite were determined at the heating rates of 1.5,2.0,2.5 and 3.0℃/min in 5 Pa vacuum at 300−1400℃,respectively.Model-free analysis and model-based analysis were applied for simulating the kinetic mechanism.By analyzing the characteristics of the initial and final reaction temperatures of TG curve,ratio of half-width of derivative TG curve and kinetic parameters,a conclusion was made that the most probable mechanism function is the first order formal chemical reaction with activation energy of 233.42 kJ/mol and pre-exponential factor of 5.14×1010 s−1.This study provides the basic data of dynamics of silicothermic magnesium production under vacuum conditions.展开更多
The electrochemical reaction rate strongly depends on the pH of the solution and the relatively sluggish alkaline hydrogen evolution reaction(HER)process,attributed to alterations in the type of proton donor and bindi...The electrochemical reaction rate strongly depends on the pH of the solution and the relatively sluggish alkaline hydrogen evolution reaction(HER)process,attributed to alterations in the type of proton donor and binding energy,has consistently presented a significant challenge.Here,we report a new method for boosting alkaline HER via spontaneous built-in electric field strategy employed on cobalt phosphide nanofibers(NFs)electrocatalyst.The anion-cation dual-introduction of V and N on the NFs not only increases the electrochemical surface area but also enhances the catalytic activity,thereby elevating the performance of alkaline HER.An investigation strategy combining experiments and calculations revealed the charge transfer law between multiple active components and the enhanced regulation mechanism of alkaline HER process,ultimately achieving a nearly twice increase in reaction overpotential of the as-fabricated catalyst at-10 mA·cm^(-2).This new approach provides a potential strategy for improving the efficiency of core catalyst for energy conversion technologies.展开更多
Reading guide 1778Repair of long-segment peripheral nerve defects1779Bionic reconstruction of hand function after adult brachial plexus root avulsion1780Optimized design of regeneration material for the treatment of p...Reading guide 1778Repair of long-segment peripheral nerve defects1779Bionic reconstruction of hand function after adult brachial plexus root avulsion1780Optimized design of regeneration material for the treatment of peripheral nerve injury1781Synergism of electroactive polymeric materials and electrical stimulation promotes peripheral nerve repair1783Schwann cell effect on peripheral nerve repair and regeneration .展开更多
X-ray photoelectron spectroscopy(XPS)and Raman spectroscopy were used to analyze the complexes in LiCl−KCl eutectic salt containing VCl_(3) and KF.The additional fluoride ions would replace chloride ions and combine w...X-ray photoelectron spectroscopy(XPS)and Raman spectroscopy were used to analyze the complexes in LiCl−KCl eutectic salt containing VCl_(3) and KF.The additional fluoride ions would replace chloride ions and combine with V(Ⅲ)to form VF_(6)^(3-).The electrochemical behavior of V(Ⅲ)was evaluated under condition of the molar concentration ratio of F−to Vn+(α)equal to 0:1,1:1,2:1,5:1,20:1 and 50:1,respectively.The results showed that a new reduction step appeared:VF_(6)^(3-)→V^(2+),and the reduction mechanism of vanadium ions became more complicated.The metallic vanadium was deposited on the tungsten electrode at−2.90 V in the LiCl−KCl melts for 6 h,and the products were characterized by SEM−EDS.It was indicated that the particle size of the product decreased with adding fluoride ions for the forming of the coordination compound VF_(6)^(3-).展开更多
文摘目的建立一种基于近红外光谱技术快速测定甘薯多糖的方法。方法通过采集来自不同地区的74个甘薯及甘薯干的近红外光谱图,对异常样本进行剔除与回收后随机选择其中56个作为校正集,11个作为验证集。通过一阶导数、二阶导数、多元散射校正(multiplicative signal correction,MSC)、标准正态变量变换(standard normal variate,SNV)等组合预处理方式对原始光谱进行处理,比较多元线性回归(stepwise multiple linear regression,SMLR)、主成分回归(principal component regression,PCR)和偏最小二乘法(partial least squares,PLS)3种方法建立的模型结果,进一步选择波段确定最佳甘薯多糖含量测定方法。结果PLS建立的模型整体精确度最佳,最优模型的预处理方式为一阶导数处理,该模型的最佳波段范围为4000~10000 cm^(-1),校正集均方根误差(root mean square error of calibration set,RMSEC)为0.50,校正集相关系数(correlation coefficient of calibration set,R;)为0.9683,验证集均方根误差(root mean square error of prediction set,RMSEP)为0.43,验证集相关系数(correlation coefficient of prediction set,R;)为0.9440,主成分数为8。结论通过近红外光谱技术结合偏最小二乘法建立甘薯多糖模型可作为甘薯多糖快速测定的可行性方法。
基金the National Science Foundation of China(Nos.50934001 and 51322402)the National High-Tech Research and Development Program of China (No.2012AA062302)+2 种基金the Program of the Co-construction with Beijing Municipal Commission of Education of China (Nos.00012047 and 00012085)the Program for New Century Excellent Talents in Universities(NCET-11-0577)the Fundamental Research Funds for the Central Universities(No.FRF-AS-11-003A)
文摘TiClx （x=2.17） was prepared by using titanium sponge to reduce the concentration of TiCl4 in a NaCl-KCl melt under negative pressure. The as-prepared NaCl-KCl-TiClx melt was employed as the electrolyte, and two parallel crude titanium plates and one high-purity titanium plate were used as the anode and cathode, respectively. A series of electrochemical tests were performed to investigate the influence of electrolytic parameters on the current efficiency and quality of cathodic products. The results indicated that the quality of cathodic products was related to the current efficiency, which is significantly dependent on the current density and the initial concentration of titanium ions. The significance of this study is the attainment of high-purity titanium with a low oxygen content of 30× 10^-6.
基金grants from the National Natural Science Foundation of China(No.81770353)the Abbott China research fund(ADD-2017).
文摘Background:The early identification of heart failure(HF)risk may favorably affect outcomes,and the combination of multiple biomarkers may provide a more comprehensive and valuable means for improving the risk of stratification.This study was conducted to assess the importance of individual cardiac biomarkers creatine kinase MB isoenzyme(CK-MB),B-type natriuretic peptide(BNP),galectin-3(Gal-3)and soluble suppression of tumorigenicity-2(sST2)for HF diagnosis,and the predictive performance of the combination of these four biomarkers was analyzed using random forest algorithms.Methods:A total of 193 participants(80 patients with HF and 113 age-and gender-matched healthy controls)were included from June 2017 to December 2017.The correlation and regression analysis were conducted between cardiac biomarkers and echocardiographic parameters.The accuracy and importance of these predictor variables were assessed using random forest algorithms.Results:Patients with HF exhibited significantly higher levels of CK-MB,BNP,Gal-3,and sST2.BNP exhibited a good independent predictive capacity for HF(AUC 0.956).However,CK-MB,sST2,and Gal-3 exhibited a modest diagnostic performance for HF,with an AUC of 0.709,0.711,and 0.777,respectively.BNP was the most important variable,with a remarkably higher mean decrease accuracy and Gini.Furthermore,there was a general increase in predictive performance using the multi-marker model,and the sensitivity,specificity was 91.5%and 96.7%,respectively.Conclusion:The random forest algorithm provides a robust method to assess the accuracy and importance of predictor variables.The combination of CK-MB,BNP,Gal-3,and sST2 achieves improvement in prediction accuracy for HF.
基金Project(2016YFB0301100)supported by the National Key R&D Program of ChinaProject(51804277)supported by the National Natural Science Foundation of ChinaProject(2018ZE007)supported by the Rare and Precious Metal Materials Genome Engineering Project of Yunnan Province,China。
文摘The investigation of silicothermic reduction of CaO·MgO was carried out using a self-developed thermogravimetric analysis(TGA)instrument under vacuum and high temperature conditions.The TG data of pellets prepared with calcined dolomite,ferrosilicon and fluorite were determined at the heating rates of 1.5,2.0,2.5 and 3.0℃/min in 5 Pa vacuum at 300−1400℃,respectively.Model-free analysis and model-based analysis were applied for simulating the kinetic mechanism.By analyzing the characteristics of the initial and final reaction temperatures of TG curve,ratio of half-width of derivative TG curve and kinetic parameters,a conclusion was made that the most probable mechanism function is the first order formal chemical reaction with activation energy of 233.42 kJ/mol and pre-exponential factor of 5.14×1010 s−1.This study provides the basic data of dynamics of silicothermic magnesium production under vacuum conditions.
基金financially supported by the National Natural Science Foundation of China(No.52304335)China Postdoctoral Science Foundation(No.2023TQ0303)+3 种基金the Postdoctoral Fellowship Program of CPSF(No.GZC20232450)the Project of Zhongyuan Critical Metals Laboratory(Nos.GJJSGFYQ202305 and GJJSGFJQ202302)the Youth Science and technology innovation of Henan Province(No.23HASTIT009)Henan Province Youth Talent Support Program(2022)。
文摘The electrochemical reaction rate strongly depends on the pH of the solution and the relatively sluggish alkaline hydrogen evolution reaction(HER)process,attributed to alterations in the type of proton donor and binding energy,has consistently presented a significant challenge.Here,we report a new method for boosting alkaline HER via spontaneous built-in electric field strategy employed on cobalt phosphide nanofibers(NFs)electrocatalyst.The anion-cation dual-introduction of V and N on the NFs not only increases the electrochemical surface area but also enhances the catalytic activity,thereby elevating the performance of alkaline HER.An investigation strategy combining experiments and calculations revealed the charge transfer law between multiple active components and the enhanced regulation mechanism of alkaline HER process,ultimately achieving a nearly twice increase in reaction overpotential of the as-fabricated catalyst at-10 mA·cm^(-2).This new approach provides a potential strategy for improving the efficiency of core catalyst for energy conversion technologies.
基金supported by the National Natural Science Foundation of ChinaNo.31271055+37 种基金3147094420906088funded by the Chinese National Ministry of Science and Technology 973 ProjectNo.2014CB542201863 ProjectNo.SS2015AA020501the Ministry of Education Innovation Team(IRT1201)the National Natural Science FundNo.31571235313712103127128431171150the Educational Ministry New Century Excellent Talents Support ProjectNo.BMU20110270supported by the National Natural Science Foundation of ChinaNo.31200799 and 81571198the New Century Excellent Talents in UniversityNo.NCET-12-0742the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)supported by the Key Talent Fund Project of "Science Education for Health"Engineering of Health Department of Jiangsu Province of ChinaNo.RC2011101funded by Chinese National Ministry of Science and Technology 973 ProjectNo.2014CB542202Natural Science Foundation of ChinaNo.8137135481571182Natural Science Foundation of Guangdong ProvinceNo.S2013010014697Science and Technology Foundation of Guangdong ProvinceNo.2015A020212024funded by the National Natural Science Foundation of ChinaNo.3117094631300805the People’s Liberation Army 12th Five-Year Plan PeriodNo.BWS11J025the National Basic Research Program of ChinaNo.2012CB5181062014CB542201
文摘Reading guide 1778Repair of long-segment peripheral nerve defects1779Bionic reconstruction of hand function after adult brachial plexus root avulsion1780Optimized design of regeneration material for the treatment of peripheral nerve injury1781Synergism of electroactive polymeric materials and electrical stimulation promotes peripheral nerve repair1783Schwann cell effect on peripheral nerve repair and regeneration .
基金supports from the National Key Research and Development Program of China (No.2021YFC2901600)supported by the State Key Laboratory of Special Rare Metal Materials (No.SKL2020K004)。
文摘X-ray photoelectron spectroscopy(XPS)and Raman spectroscopy were used to analyze the complexes in LiCl−KCl eutectic salt containing VCl_(3) and KF.The additional fluoride ions would replace chloride ions and combine with V(Ⅲ)to form VF_(6)^(3-).The electrochemical behavior of V(Ⅲ)was evaluated under condition of the molar concentration ratio of F−to Vn+(α)equal to 0:1,1:1,2:1,5:1,20:1 and 50:1,respectively.The results showed that a new reduction step appeared:VF_(6)^(3-)→V^(2+),and the reduction mechanism of vanadium ions became more complicated.The metallic vanadium was deposited on the tungsten electrode at−2.90 V in the LiCl−KCl melts for 6 h,and the products were characterized by SEM−EDS.It was indicated that the particle size of the product decreased with adding fluoride ions for the forming of the coordination compound VF_(6)^(3-).
