The electrochemical performances of cathode play a key role in the marine sediment microbial fuel cells(MSMFCs)as a long lasting power source to drive instruments,especially when the dissolved oxygen concentration is ...The electrochemical performances of cathode play a key role in the marine sediment microbial fuel cells(MSMFCs)as a long lasting power source to drive instruments,especially when the dissolved oxygen concentration is very low in seawater.A CTS-Fe^(3+)modified cathode is prepared here by grafting chitosan(CTS)on a carbon fiber surface and then chelating Fe^(3+)through the coordination process.The electrochemical performance in seawater and the output power of the assembled MSMFCs are both studied.The results show that the exchange current densities of CTS and the CTS-Fe^(3+)group are 5.5 and 6.2 times higher than that of the blank group,respectively.The potential of the CTS-Fe^(3+)modified cathode increases by 138 mV.The output power of the fuel cell(613.0 mW m^(-2))assembled with CTS-Fe^(3+)is 54 times larger than that of the blank group(11.4 mW m^(-2))and the current output corresponding with the maximum power output also increases by 56 times.Due to the valence conversion between Fe^(3+)and Fe^(2+)on the modified cathode,the kinetic activity of the dissolved oxygen reduction is accelerated and the depolarization capability of the cathode is enhanced,resulting higher cell power.On the basis of this study,the new cathode materials will be encouraged to design with the complex of iron ion in natural seawater as the catalysis for oxygen reduction to improve the cell power in deep sea.展开更多
Anode modification plays a key role in higher power output in marine sediment microbial fuel cells(MSMFCs).A low-molecular organosilicon compound(3-aminopropyltriethoxysilane)was grafted onto the surface of carbon fel...Anode modification plays a key role in higher power output in marine sediment microbial fuel cells(MSMFCs).A low-molecular organosilicon compound(3-aminopropyltriethoxysilane)was grafted onto the surface of carbon felt using chemical method and a composite modified anode was prepared through organic ligands coordination Fe^(3+)for better electro-chemical per-formance.Results show that the biofilm resistance of the composite modified anode(2707Ω)is 1.3 times greater than that of the unmodified anode(2100Ω),and its biofilm capacitance also increases by 2.2 times,indicating that the composite modification pro-motes the growth and attachment of electroactive bacteria on the anode.Its specific capacitance(887.8 Fm^(−2))is 3.7 times higher than that of unmodified anode,generating a maximum current density of 1.5Am^(−2).In their Tafel curves,the composite modified anodic exchange current density(5.25×10^(−6)Acm^(−2))is 5.8 times bigger than that of unmodified anode,which suggests that the electro-chemical activity of redox,anti-polarization ability and electron transfer kinetic activity are significantly enhanced.The marine sediment microbial fuel cell with the composite modified anode generates the higher power densities than the blank(203.8mWm^(−2) versus 45.07mWm^(−2)),and its current also increases by 4.4 times.The free amino groups on the anode surface expands a creative idea that the modified anode ligates the natural Fe(Ⅲ)ion in sea water in the MSMFCs for its higher power output.展开更多
目的:探讨超声甲状腺影像报告和数据系统(Thyroid Imaging Report and Data System,TI-RADS)、甲状腺细胞病理学Bethesda报告系统(The Bethesda System for Reporting Thyroid Cytopathology,BSRTC)与BRAF V600E突变分析在甲状腺良恶性...目的:探讨超声甲状腺影像报告和数据系统(Thyroid Imaging Report and Data System,TI-RADS)、甲状腺细胞病理学Bethesda报告系统(The Bethesda System for Reporting Thyroid Cytopathology,BSRTC)与BRAF V600E突变分析在甲状腺良恶性结节鉴别诊断中的价值。方法:回顾并分析行手术切除的1093个甲状腺结节的术前超声检查、超声引导下细针穿刺活检(fine-needle aspiration biopsy,FNAB)与BRAF V600E突变分析结果。依据TI-RADS分类标准对结节进行分类,采用BSRTC对结节进行细胞学诊断。分别计算3种方法的灵敏度、特异度及曲线下面积(area under curve,AUC)。结果:单独应用时,TI-RADS诊断甲状腺良恶性结节的灵敏度、阴性预测值和准确度最高,分别为99.21%、84.00%和95.97%;BSRTC诊断阳性预测值和约登指数最高,分别为99.22%和78.52%;BRAF V600E突变分析的AUC最高,为0.893;BRAF V600E突变分析和BSRTC特异度最高,均为91.03%。联合应用时,BSRTC联合BRAF V600E突变分析的诊断特异度、阳性预测值、约登指数、准确度和AUC最高,分别为84.62%、98.77%、79.60%、98.90%和0.898;三者联合诊断的灵敏度、阴性预测值最高,分别为99.61%、91.11%。对于BSRTCⅠ、Ⅲ、Ⅳ类结节,联合TI-RADS、BRAF V600E突变分析可以减少误诊,提高恶性结节检出率。结论:BSRTC、TI-RADS与BRAF V600E突变分析与在甲状腺结节诊断中均有较高的价值,三者联合有助于进一步提高甲状腺结节诊断的准确度,减少误判。展开更多
基金supported by the National Natural Science Foundation of China(No.22075262)。
文摘The electrochemical performances of cathode play a key role in the marine sediment microbial fuel cells(MSMFCs)as a long lasting power source to drive instruments,especially when the dissolved oxygen concentration is very low in seawater.A CTS-Fe^(3+)modified cathode is prepared here by grafting chitosan(CTS)on a carbon fiber surface and then chelating Fe^(3+)through the coordination process.The electrochemical performance in seawater and the output power of the assembled MSMFCs are both studied.The results show that the exchange current densities of CTS and the CTS-Fe^(3+)group are 5.5 and 6.2 times higher than that of the blank group,respectively.The potential of the CTS-Fe^(3+)modified cathode increases by 138 mV.The output power of the fuel cell(613.0 mW m^(-2))assembled with CTS-Fe^(3+)is 54 times larger than that of the blank group(11.4 mW m^(-2))and the current output corresponding with the maximum power output also increases by 56 times.Due to the valence conversion between Fe^(3+)and Fe^(2+)on the modified cathode,the kinetic activity of the dissolved oxygen reduction is accelerated and the depolarization capability of the cathode is enhanced,resulting higher cell power.On the basis of this study,the new cathode materials will be encouraged to design with the complex of iron ion in natural seawater as the catalysis for oxygen reduction to improve the cell power in deep sea.
基金This work was supported by the National Natural Sci-ence Foundation of China(No.22075262).
文摘Anode modification plays a key role in higher power output in marine sediment microbial fuel cells(MSMFCs).A low-molecular organosilicon compound(3-aminopropyltriethoxysilane)was grafted onto the surface of carbon felt using chemical method and a composite modified anode was prepared through organic ligands coordination Fe^(3+)for better electro-chemical per-formance.Results show that the biofilm resistance of the composite modified anode(2707Ω)is 1.3 times greater than that of the unmodified anode(2100Ω),and its biofilm capacitance also increases by 2.2 times,indicating that the composite modification pro-motes the growth and attachment of electroactive bacteria on the anode.Its specific capacitance(887.8 Fm^(−2))is 3.7 times higher than that of unmodified anode,generating a maximum current density of 1.5Am^(−2).In their Tafel curves,the composite modified anodic exchange current density(5.25×10^(−6)Acm^(−2))is 5.8 times bigger than that of unmodified anode,which suggests that the electro-chemical activity of redox,anti-polarization ability and electron transfer kinetic activity are significantly enhanced.The marine sediment microbial fuel cell with the composite modified anode generates the higher power densities than the blank(203.8mWm^(−2) versus 45.07mWm^(−2)),and its current also increases by 4.4 times.The free amino groups on the anode surface expands a creative idea that the modified anode ligates the natural Fe(Ⅲ)ion in sea water in the MSMFCs for its higher power output.
文摘目的:探讨超声甲状腺影像报告和数据系统(Thyroid Imaging Report and Data System,TI-RADS)、甲状腺细胞病理学Bethesda报告系统(The Bethesda System for Reporting Thyroid Cytopathology,BSRTC)与BRAF V600E突变分析在甲状腺良恶性结节鉴别诊断中的价值。方法:回顾并分析行手术切除的1093个甲状腺结节的术前超声检查、超声引导下细针穿刺活检(fine-needle aspiration biopsy,FNAB)与BRAF V600E突变分析结果。依据TI-RADS分类标准对结节进行分类,采用BSRTC对结节进行细胞学诊断。分别计算3种方法的灵敏度、特异度及曲线下面积(area under curve,AUC)。结果:单独应用时,TI-RADS诊断甲状腺良恶性结节的灵敏度、阴性预测值和准确度最高,分别为99.21%、84.00%和95.97%;BSRTC诊断阳性预测值和约登指数最高,分别为99.22%和78.52%;BRAF V600E突变分析的AUC最高,为0.893;BRAF V600E突变分析和BSRTC特异度最高,均为91.03%。联合应用时,BSRTC联合BRAF V600E突变分析的诊断特异度、阳性预测值、约登指数、准确度和AUC最高,分别为84.62%、98.77%、79.60%、98.90%和0.898;三者联合诊断的灵敏度、阴性预测值最高,分别为99.61%、91.11%。对于BSRTCⅠ、Ⅲ、Ⅳ类结节,联合TI-RADS、BRAF V600E突变分析可以减少误诊,提高恶性结节检出率。结论:BSRTC、TI-RADS与BRAF V600E突变分析与在甲状腺结节诊断中均有较高的价值,三者联合有助于进一步提高甲状腺结节诊断的准确度,减少误判。
