AIM:To investigate the relationship between blood riboflavin levels and riboflavin transporter 2(RFT2) gene expression in gastric carcinoma(GC) development.METHODS:High-performance liquid chromatography was used to de...AIM:To investigate the relationship between blood riboflavin levels and riboflavin transporter 2(RFT2) gene expression in gastric carcinoma(GC) development.METHODS:High-performance liquid chromatography was used to detect blood riboflavin levels in patients with GC.Real-time fluorogenic quantitative polymerase chain reaction and immunohistochemistry were used to analyze the expression of RFT2 mRNA and protein in samples from 60 GC patients consisting of both tumor and normal tissue.RESULTS:A significant decrease in the RFT2 mRNA levels was detected in GC samples compared with those in the normal mucous membrane(0.398 ± 0.149 vs 1.479 ± 0.587;P = 0.040).Tumors exhibited low RFT2 protein expression(75%,16.7%,8.3% and 0% for no RFT2 staining,weak staining,medium staining and strong staining,respectively),which was significantly lower than that in the normal mucous membrane(10%,16.7%,26.7% and 46.7% for no RFT2 staining,weak staining,medium staining and strong staining,respectively;P < 0.05).Tumors with low RFT2 expression were significantly associated with tumor stage and histological grade.Moreover,a significantly decrease in Uyghur patients was observed compared with Han patients.However,other parameters-gender,tumor location and lymph node metastasis-showed no significant relationship with RFT2 expression.Blood riboflavin levels were reverse correlated with development of GC(1.2000 ± 0.97 569 ng/mL in high tumor stage patients vs 2.5980 ± 1.31 129 ng/mL in low tumor stage patients;P < 0.05).A positive correlation of plasma riboflavin levels with defective expression of RFT2 protein was found in GC patients(2 = 2.619;P = 0.019).CONCLUSION:Defective expression of RFT2 is associated with the development of GC and this may represent a mechanism underlying the decreased plasma riboflavin levels in GC.展开更多
针对卡方自动交互诊断(CHAID)决策树易过拟合的问题,提出CHAID随机森林方法(CHAID Random Forest,CHAID-RF)。该方法采用随机采样、随机选择特征以及集成的策略,将CHAID决策树作为基分类器,形成CHAID-RF。为了验证CHAID-RF的有效性,选取...针对卡方自动交互诊断(CHAID)决策树易过拟合的问题,提出CHAID随机森林方法(CHAID Random Forest,CHAID-RF)。该方法采用随机采样、随机选择特征以及集成的策略,将CHAID决策树作为基分类器,形成CHAID-RF。为了验证CHAID-RF的有效性,选取CART、CHAID、SVM、RF作为对比算法,以准确率、加权查准率、加权查全率、加权F值作为分类模型评价指标,以均方根误差作为回归模型评价指标,采用10个分类数据集和7个回归数据集进行验证。实验结果表明CHAID-RF可行有效。展开更多
Efficient,cost‐effective electrocatalysts for an oxygen reduction reaction(ORR)are currently required for fuel cells.In the present work,riboflavin was used as a cheap,nontoxic carbon and nitrogen precursor to prepar...Efficient,cost‐effective electrocatalysts for an oxygen reduction reaction(ORR)are currently required for fuel cells.In the present work,riboflavin was used as a cheap,nontoxic carbon and nitrogen precursor to prepare Fe-N-C catalysts via one‐step pyrolysis in the presence of anhydrous iron chloride.Raman spectroscopy indicated that the catalyst containing nitrogen created a great quantity of defects in the carbon structures,while nitrogen adsorption‐desorption isotherms showed that the catalyst was mesoporous.Transmission electron microscopy demonstrated that the Fe-N-C catalyst was composed of very thin,curved and porous graphene layers together with some Fe2O3nanoparticles,and X‐ray diffraction patterns confirmed that the carbon in the catalyst was highly graphitized.X‐ray photoelectron spectroscopy indicated that the active sites for the ORR were primarily composed of graphitic nitrogen,although Fe sites also played an important role.The ORR activity of the Fe-N-C catalyst reached a maximum of4.16mA cm-2,and its chronoamperometric response was found to decrease by only3%after operating for3h at0.66V(vs RHE)in an O2‐saturated0.1mol L-1KOH solution.In contrast,a commercial40wt%Pt/C catalyst with a loading of0.2mgPt cm-2exhibited an activity of4.46mA cm-2and a40%loss of response.The electrochemical performance of this new Fe-N-C catalyst was therefore comparable to that of the Pt/C catalyst while showing significantly better stability.展开更多
基金Supported by The National Natural Science Foundation of China,No.81160459
文摘AIM:To investigate the relationship between blood riboflavin levels and riboflavin transporter 2(RFT2) gene expression in gastric carcinoma(GC) development.METHODS:High-performance liquid chromatography was used to detect blood riboflavin levels in patients with GC.Real-time fluorogenic quantitative polymerase chain reaction and immunohistochemistry were used to analyze the expression of RFT2 mRNA and protein in samples from 60 GC patients consisting of both tumor and normal tissue.RESULTS:A significant decrease in the RFT2 mRNA levels was detected in GC samples compared with those in the normal mucous membrane(0.398 ± 0.149 vs 1.479 ± 0.587;P = 0.040).Tumors exhibited low RFT2 protein expression(75%,16.7%,8.3% and 0% for no RFT2 staining,weak staining,medium staining and strong staining,respectively),which was significantly lower than that in the normal mucous membrane(10%,16.7%,26.7% and 46.7% for no RFT2 staining,weak staining,medium staining and strong staining,respectively;P < 0.05).Tumors with low RFT2 expression were significantly associated with tumor stage and histological grade.Moreover,a significantly decrease in Uyghur patients was observed compared with Han patients.However,other parameters-gender,tumor location and lymph node metastasis-showed no significant relationship with RFT2 expression.Blood riboflavin levels were reverse correlated with development of GC(1.2000 ± 0.97 569 ng/mL in high tumor stage patients vs 2.5980 ± 1.31 129 ng/mL in low tumor stage patients;P < 0.05).A positive correlation of plasma riboflavin levels with defective expression of RFT2 protein was found in GC patients(2 = 2.619;P = 0.019).CONCLUSION:Defective expression of RFT2 is associated with the development of GC and this may represent a mechanism underlying the decreased plasma riboflavin levels in GC.
文摘针对卡方自动交互诊断(CHAID)决策树易过拟合的问题,提出CHAID随机森林方法(CHAID Random Forest,CHAID-RF)。该方法采用随机采样、随机选择特征以及集成的策略,将CHAID决策树作为基分类器,形成CHAID-RF。为了验证CHAID-RF的有效性,选取CART、CHAID、SVM、RF作为对比算法,以准确率、加权查准率、加权查全率、加权F值作为分类模型评价指标,以均方根误差作为回归模型评价指标,采用10个分类数据集和7个回归数据集进行验证。实验结果表明CHAID-RF可行有效。
基金supported by Open Project from State Key Laboratory of Catalysis(N-14-1)Scientific Research Foundation for Returned Scholars,Ministry of Education of ChinaInternational Technology Collaboration of Chengdu Science and Technology Division~~
文摘Efficient,cost‐effective electrocatalysts for an oxygen reduction reaction(ORR)are currently required for fuel cells.In the present work,riboflavin was used as a cheap,nontoxic carbon and nitrogen precursor to prepare Fe-N-C catalysts via one‐step pyrolysis in the presence of anhydrous iron chloride.Raman spectroscopy indicated that the catalyst containing nitrogen created a great quantity of defects in the carbon structures,while nitrogen adsorption‐desorption isotherms showed that the catalyst was mesoporous.Transmission electron microscopy demonstrated that the Fe-N-C catalyst was composed of very thin,curved and porous graphene layers together with some Fe2O3nanoparticles,and X‐ray diffraction patterns confirmed that the carbon in the catalyst was highly graphitized.X‐ray photoelectron spectroscopy indicated that the active sites for the ORR were primarily composed of graphitic nitrogen,although Fe sites also played an important role.The ORR activity of the Fe-N-C catalyst reached a maximum of4.16mA cm-2,and its chronoamperometric response was found to decrease by only3%after operating for3h at0.66V(vs RHE)in an O2‐saturated0.1mol L-1KOH solution.In contrast,a commercial40wt%Pt/C catalyst with a loading of0.2mgPt cm-2exhibited an activity of4.46mA cm-2and a40%loss of response.The electrochemical performance of this new Fe-N-C catalyst was therefore comparable to that of the Pt/C catalyst while showing significantly better stability.
