目的研究渗透树脂在正畸邻面去釉后的防龋效果。方法使用渗透树脂(ICON)和氟化物分别对邻面去釉后的牙釉质进行处理。采用半口对照试验,随机将患者分为两组:A组将试验组渗透树脂应用在患者口腔1、3象限,将对照组氟化物应用在患者口腔2、...目的研究渗透树脂在正畸邻面去釉后的防龋效果。方法使用渗透树脂(ICON)和氟化物分别对邻面去釉后的牙釉质进行处理。采用半口对照试验,随机将患者分为两组:A组将试验组渗透树脂应用在患者口腔1、3象限,将对照组氟化物应用在患者口腔2、4象限;B组将渗透树脂应用在患者口腔2、4象限,将氟化物应用在患者口腔1、3象限。术后在第3、6、9、12个月进行随访,采用外观观察和放射检查两种方法进行评估,观察渗透树脂与氟化物在不同时间段的防龋效果。结果两处理组在术后3、6、9个月的ICDAS-Ⅱ分级和放射检查比较,差异均无统计学意义(P>0.05)。术后12个月,ICON组的ICDAS-Ⅱ评分及放射检查评分均显著小于3M Clinpro^TM White Varnish组,差异有统计学意义(P<0.05)。结论 ICON渗透树脂可以很好地预防邻面去釉后的釉质发生龋坏。展开更多
Biomorphic （wood derived） carbide ceramics with an overall composition in the SiC/C was produced by supereritical ethanol infiltration of low viscosity tetraethylorthosilicate/supercritical ethanol into biologically...Biomorphic （wood derived） carbide ceramics with an overall composition in the SiC/C was produced by supereritical ethanol infiltration of low viscosity tetraethylorthosilicate/supercritical ethanol into biologically derived carbon templates （CB-templates） and in situ hydrolysis into Si（OH）4-gel, the Si（OH）4-gel was calcined at 1400℃ to promote the polycondensation of Si（OH）4-gel into SiO2-phase and then carbonthermal reduction of the SiO2 with the biocarbon template into highly porous, biomorphic SiC/C ceramics. The phases and morphology conversion mechanism of resulting porous SiC/C ceramics have been investigated by X-ray diffraction （XRD）, scanning electron microscopy （SEM）, transmission electron microscopy （TEM）, and Fourier transform infrared spectroscopy （FT-IR）. Experimental results showed that the biomorphic cellular morphology of pinewood charcoal was remained in the porous SiC/C ceramic with high precision that consisted of β-SiC with minority of α-SiC and the remain free carbon existed in amorphous phase.展开更多
Sluggish oxygen reduction reaction(ORR)kinetics are a major obstacle to developing intermediate-temperature solid-oxide fuel cells(IT-SOFCs).In particular,engineering the anion defect concentration at an interface bet...Sluggish oxygen reduction reaction(ORR)kinetics are a major obstacle to developing intermediate-temperature solid-oxide fuel cells(IT-SOFCs).In particular,engineering the anion defect concentration at an interface between the cathode and electrolyte is important for facilitating ORR kinetics and hence improving the electrochemical performance.We developed the yttria-stabilized zirconia(YSZ)nanofiber(NF)-based composite cathode,where the oxygen vacancy concentration is controlled by varying the dopant cation(Y2O3)ratio in the YSZ NFs.The composite cathode with the optimized oxygen vacancy concentration exhibits maximum power densities of 2.66 and 1.51 W cm^(−2)at 700 and 600℃,respectively,with excellent thermal stability at 700℃ over 500 h under 1.0 A cm^(−2).Electrochemical impedance spectroscopy and distribution of relaxation time analysis revealed that the high oxygen vacancy concentration in the NF-based scaffold facilitates the charge transfer and incorporation reaction occurred at the interfaces between the cathode and electrolyte.Our results demonstrate the high feasibility and potential of interface engineering for achieving IT-SOFCs with higher performance and stability.展开更多
文摘目的研究渗透树脂在正畸邻面去釉后的防龋效果。方法使用渗透树脂(ICON)和氟化物分别对邻面去釉后的牙釉质进行处理。采用半口对照试验,随机将患者分为两组:A组将试验组渗透树脂应用在患者口腔1、3象限,将对照组氟化物应用在患者口腔2、4象限;B组将渗透树脂应用在患者口腔2、4象限,将氟化物应用在患者口腔1、3象限。术后在第3、6、9、12个月进行随访,采用外观观察和放射检查两种方法进行评估,观察渗透树脂与氟化物在不同时间段的防龋效果。结果两处理组在术后3、6、9个月的ICDAS-Ⅱ分级和放射检查比较,差异均无统计学意义(P>0.05)。术后12个月,ICON组的ICDAS-Ⅱ评分及放射检查评分均显著小于3M Clinpro^TM White Varnish组,差异有统计学意义(P<0.05)。结论 ICON渗透树脂可以很好地预防邻面去釉后的釉质发生龋坏。
基金Financial supports by National Science Foundation of China （No. 40602008） Research Fund of National Laboratory of Mineral Materials （No. 05005A） are gratefully acknowledged.
文摘Biomorphic （wood derived） carbide ceramics with an overall composition in the SiC/C was produced by supereritical ethanol infiltration of low viscosity tetraethylorthosilicate/supercritical ethanol into biologically derived carbon templates （CB-templates） and in situ hydrolysis into Si（OH）4-gel, the Si（OH）4-gel was calcined at 1400℃ to promote the polycondensation of Si（OH）4-gel into SiO2-phase and then carbonthermal reduction of the SiO2 with the biocarbon template into highly porous, biomorphic SiC/C ceramics. The phases and morphology conversion mechanism of resulting porous SiC/C ceramics have been investigated by X-ray diffraction （XRD）, scanning electron microscopy （SEM）, transmission electron microscopy （TEM）, and Fourier transform infrared spectroscopy （FT-IR）. Experimental results showed that the biomorphic cellular morphology of pinewood charcoal was remained in the porous SiC/C ceramic with high precision that consisted of β-SiC with minority of α-SiC and the remain free carbon existed in amorphous phase.
基金supported by the National Research Foundation of Korea (NRF) Grant funded by the Korean government (MSIT)(Nos. 2022R1A2C3012372 and 2022R1A4A1031182)Korea Institute for Advancement of Technology(KIAT)Competency Development Program for Industry Specialists of Korean Ministry of Trade,Industry and Energy Grant funded by the Korea Government(MOTIE)(No. P0008458, The Competency Development Program for Industry Specialist and No. P0017120, HRD program for Foster R&D specialist of parts for ecofriendly vehicle (xEV))
文摘Sluggish oxygen reduction reaction(ORR)kinetics are a major obstacle to developing intermediate-temperature solid-oxide fuel cells(IT-SOFCs).In particular,engineering the anion defect concentration at an interface between the cathode and electrolyte is important for facilitating ORR kinetics and hence improving the electrochemical performance.We developed the yttria-stabilized zirconia(YSZ)nanofiber(NF)-based composite cathode,where the oxygen vacancy concentration is controlled by varying the dopant cation(Y2O3)ratio in the YSZ NFs.The composite cathode with the optimized oxygen vacancy concentration exhibits maximum power densities of 2.66 and 1.51 W cm^(−2)at 700 and 600℃,respectively,with excellent thermal stability at 700℃ over 500 h under 1.0 A cm^(−2).Electrochemical impedance spectroscopy and distribution of relaxation time analysis revealed that the high oxygen vacancy concentration in the NF-based scaffold facilitates the charge transfer and incorporation reaction occurred at the interfaces between the cathode and electrolyte.Our results demonstrate the high feasibility and potential of interface engineering for achieving IT-SOFCs with higher performance and stability.
