The electrochemical synthesis of three-dimensional (3D) polyaniline (PAN) network structure on 3-aminobenzenesulfonic acid (ABSA) functionalized glassy carbon electrode (GCE) and its electro-catalytic oxidation toward...The electrochemical synthesis of three-dimensional (3D) polyaniline (PAN) network structure on 3-aminobenzenesulfonic acid (ABSA) functionalized glassy carbon electrode (GCE) and its electro-catalytic oxidation towards ascorbic acid (AA) had been studied. ABSA was first covalently grafted on GCE surface via the direct electrochemical oxidation of ABSA on GCE, which was followed by the electrochemical polymerization of aniline on the ABSA functionalized GCE. Then PAN-ABSA composite film modified GCE (PAN-ABSA/GCE) was obtained. Scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS), electrochemical impedance spectroscopy (EIS) and electrochemical techniques had been employed to characterize the obtained electrodes. Due to the effective doping of ABSA in PAN, the redox electro-activity of PAN had been extended to neutral and even the basic media, thus, the PAN-ABSA composite film modified GCE could be used for electro-catalytic oxidation of AA in 0.1 M phosphate buffer solution (PBS, pH 6.8). At PAN-ABSA/GCE the oxidation over-potential of AA shifted from 0.39 V at GCE to 0.17 V with a greatly enhanced current response. The electro-catalytic oxidation peak current of AA increased linearly with the increasing AA concentration over the range of 5.00 × 10-4-1.65 × 10-2 M with a correlation coefficient of 0.9973. The detection limit (S/N = 3) for AA was 1.16 × 10-6 M. Chronoamperometry had also been employed to investigate the electro-catalytic oxidation of AA at PAN-ABSA/GCE. The modified electrode had been used for detecting AA in real samples with satisfactory results.展开更多
目的:对比三维多回波恢复梯度回波(3D MERGE)、三维可变反转角快速自旋回波(3D SPACE STIR)序列在腰椎间盘突出症(LDH)检查中的应用效果。方法:选择2020年1月~2022年11月收治的135例LDH患者,回顾性分析患者临床和磁共振成像(MRI)资料,...目的:对比三维多回波恢复梯度回波(3D MERGE)、三维可变反转角快速自旋回波(3D SPACE STIR)序列在腰椎间盘突出症(LDH)检查中的应用效果。方法:选择2020年1月~2022年11月收治的135例LDH患者,回顾性分析患者临床和磁共振成像(MRI)资料,所有患者均接受常规MRI扫描及3D MERGE、3D SPACE STIR序列扫描,对比3D MERGE、3D SPACE STIR序列测量神经根直径的一致性,评价两种序列的图像质量参数[信噪比(SNR)、对比噪声比(CNR)]、图像清晰度评分。结果:3D MERGE和3D SPACE STIR序列测量的L3~S1神经根直径比较差异无统计学意义(P>0.05),且两组序列测量的L3、L4、L5和S1直径均显示出较高相关性(r=0.957,0.986,0.975,0.972,P<0.05);3D MERGE序列的SNR及CNR均高于3D SPACE STIR序列,神经根显示分级、图像清晰度评分优于3D SPACE STIR序列,差异有统计学意义(P<0.05)。结论:3D MERGE、3D SPACE STIR序列在LDH神经根直径测量中具有极高一致性,3D MERGE序列较3D SPACE STIR序列能够更清晰显示神经跟的解剖形态,图像质量更好。展开更多
文摘The electrochemical synthesis of three-dimensional (3D) polyaniline (PAN) network structure on 3-aminobenzenesulfonic acid (ABSA) functionalized glassy carbon electrode (GCE) and its electro-catalytic oxidation towards ascorbic acid (AA) had been studied. ABSA was first covalently grafted on GCE surface via the direct electrochemical oxidation of ABSA on GCE, which was followed by the electrochemical polymerization of aniline on the ABSA functionalized GCE. Then PAN-ABSA composite film modified GCE (PAN-ABSA/GCE) was obtained. Scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS), electrochemical impedance spectroscopy (EIS) and electrochemical techniques had been employed to characterize the obtained electrodes. Due to the effective doping of ABSA in PAN, the redox electro-activity of PAN had been extended to neutral and even the basic media, thus, the PAN-ABSA composite film modified GCE could be used for electro-catalytic oxidation of AA in 0.1 M phosphate buffer solution (PBS, pH 6.8). At PAN-ABSA/GCE the oxidation over-potential of AA shifted from 0.39 V at GCE to 0.17 V with a greatly enhanced current response. The electro-catalytic oxidation peak current of AA increased linearly with the increasing AA concentration over the range of 5.00 × 10-4-1.65 × 10-2 M with a correlation coefficient of 0.9973. The detection limit (S/N = 3) for AA was 1.16 × 10-6 M. Chronoamperometry had also been employed to investigate the electro-catalytic oxidation of AA at PAN-ABSA/GCE. The modified electrode had been used for detecting AA in real samples with satisfactory results.
文摘目的:对比三维多回波恢复梯度回波(3D MERGE)、三维可变反转角快速自旋回波(3D SPACE STIR)序列在腰椎间盘突出症(LDH)检查中的应用效果。方法:选择2020年1月~2022年11月收治的135例LDH患者,回顾性分析患者临床和磁共振成像(MRI)资料,所有患者均接受常规MRI扫描及3D MERGE、3D SPACE STIR序列扫描,对比3D MERGE、3D SPACE STIR序列测量神经根直径的一致性,评价两种序列的图像质量参数[信噪比(SNR)、对比噪声比(CNR)]、图像清晰度评分。结果:3D MERGE和3D SPACE STIR序列测量的L3~S1神经根直径比较差异无统计学意义(P>0.05),且两组序列测量的L3、L4、L5和S1直径均显示出较高相关性(r=0.957,0.986,0.975,0.972,P<0.05);3D MERGE序列的SNR及CNR均高于3D SPACE STIR序列,神经根显示分级、图像清晰度评分优于3D SPACE STIR序列,差异有统计学意义(P<0.05)。结论:3D MERGE、3D SPACE STIR序列在LDH神经根直径测量中具有极高一致性,3D MERGE序列较3D SPACE STIR序列能够更清晰显示神经跟的解剖形态,图像质量更好。