Different compositions of yttrium silicates coatings were deposited on SiC-C/C by plasma spraying and an outer borosilicate glass was applied on the yttrium silicates coatings surfaces. The structure of the multi-laye...Different compositions of yttrium silicates coatings were deposited on SiC-C/C by plasma spraying and an outer borosilicate glass was applied on the yttrium silicates coatings surfaces. The structure of the multi-layer coatings was characterized by XRD and SEM analyses. High temperature oxidation behavior of the multi-layer coatings coated C/C composites was investigated. Results show that SiC/2SiO2 Y2O3/1.5SiO2 Y203/ SiO2 Y2O3/glass multi-layer coating has better high temperature oxidation resistance, protecting carbon/ carbon composites from oxidation at 1 773 K in air for 164 h with the weight loss of 1.65%. The oxidation weight loss of the coated C/C with time accorded with parabolic rule in the temperature range 1 573 K-1 873 K; and the corresponding oxidation activation energy of the coated carbon/carbon composites is 132.2 kJ/mol.展开更多
Nanocrystalline zirconia（ZrO） was synthesized using a microwave-hydrothermal process.The effect of pH on the crystallization of the ZrO2 powders was investigated.The phase and microstructure of ZrO2 powders were exa...Nanocrystalline zirconia（ZrO） was synthesized using a microwave-hydrothermal process.The effect of pH on the crystallization of the ZrO2 powders was investigated.The phase and microstructure of ZrO2 powders were examined using X-ray diffraction（XRD）,Raman spectroscopy,and transmission electron microscopy（TEM）.Results show that pure m-ZrO2 can be obtained at low pH（pH＆lt;2）.Pure t-ZrO2 is formed at pH = 7 and 14.The size of the ZrO2 crystals is in the range of 8-26 nm and decreases with increasing pH.The formation of m-ZrO2 results from the precipitation of ZrO2 from solution.The t-ZrO2 is formed through the in-situ structural rearrangement of amorphous Zr（OH）xOy.The stabilization of t-ZrO2 is attributed to the small crystal size and the adsorption of hydroxy ions on the surfaces of the crystals.展开更多
目的对比分析原发性肝癌患者及经肝动脉化疗栓塞术(TACE)治疗前后肠道菌群的多样性变化及菌群结构差异。方法选取2018年9月-2019年1月广西医科大学附属肿瘤医院原发性肝癌患者65例(其中接受TACE治疗20例),健康体检者27例。高通量16S rDN...目的对比分析原发性肝癌患者及经肝动脉化疗栓塞术(TACE)治疗前后肠道菌群的多样性变化及菌群结构差异。方法选取2018年9月-2019年1月广西医科大学附属肿瘤医院原发性肝癌患者65例(其中接受TACE治疗20例),健康体检者27例。高通量16S rDNA测序方法分析患者便菌群结构,Anosim、LEf Se软件与R语言stats包分析菌群组间物种相对丰度、组间物种多样性、群落差异、进化分支等差异。符合正态性及方差齐的计量资料两组间比较采用t检验;不符合正态分布计量资料组间比较采用Kruskal-Wallis U检验;计数资料组间比较采用χ2检验。相关性分析采取Spearman秩相关性分析。结果在门水平,各组的最大优势菌均为拟杆菌门(Bacteroidetes)、厚壁菌门(Firmicutes),两者占比之和在健康组>90%,在原发性肝癌组及TACE治疗组中占比均>80%。拟杆菌门在健康组、原发性肝癌组、TACE治疗组占比分别为48.44%、44.96%、48.60%,厚壁菌门在各组占比分别为47.09%、38.15%、33.93%,拟杆菌门、厚壁菌门相对丰度在肝癌组均低于健康组;此外,变形菌门(Proteobacteria)及梭杆菌门(Fusobacteria)相对丰度在肝癌组及TACE治疗组中占比均高于健康组;其余菌门虽有所变化,但占比均<0.5%。健康组物种丰富度Observed species(264±47 vs 230±64,t=2.499,P=0.014)及ACE值(284.11±50.82 vs 252.96±67.58,t=2.158,P=0.034)均大于原发性肝癌组。Between组(原发性肝癌组+健康组)的秩较原发性肝癌组及健康组高,R>0,健康组及原发性肝癌组肠道菌群组间结构差异大于组内差异(P<0.05);Between组(TACE术前+术后)的秩低于TACE术前组,R<0,TACE治疗前与治疗后组内结构差异大于组间结构差异(P>0.05)。原发性肝癌患者肠内机会致病菌与Child-Turcotte-Pugh评分、TBil、ALT、AST存在相关性(r值分别为0.245、0.421、0.327、0.446,P值分别为0.049、<0.001、0.008、<0.001),潜在益生菌与Child-Turcotte-Pugh评分、TBil、Alb、ALT、AST存在相关性(r值分别为-0.314、-0.490、0.285、-0.374、-0.528,P值分别为0.011、<0.001、0.022、0.002、<0.001)。差异菌中的机会致病菌相对丰度随着肝功能Child-Pugh分级递增而增加,C级高于A级(Z=4.301,P=0.038)与B级(Z=4.063,P=0.044)。而潜在益生作用菌的相对丰度随着肝功能Child-Pugh分级的增加呈现减少趋势,C级低于A级(Z=3.882,P=0.049)。结论原发性肝癌患者与健康者肠道菌群多样性及结构不同,而原发性肝癌患者TACE治疗前后肠道菌群相近,TACE治疗对肠道菌群影响较小。肠道菌群失调与原发性肝癌临床分级存在关联,随着肝功能Child-Pugh等级的递增,菌群失调程度更为明显,潜在益生作用菌减少,而机会性致病菌增加。展开更多
目的比较接受巴塞罗那临床肝癌分期系统(BCLC)或香港的分期系统(HKLC)推荐治疗方案对肝细胞肝癌(HCC)患者生存率的影响。方法回顾性分析436例初治肝癌患者的临床资料,根据HKLC和BCLC进行肿瘤分期,按是否最终接受两个分期系统推荐的治疗...目的比较接受巴塞罗那临床肝癌分期系统(BCLC)或香港的分期系统(HKLC)推荐治疗方案对肝细胞肝癌(HCC)患者生存率的影响。方法回顾性分析436例初治肝癌患者的临床资料,根据HKLC和BCLC进行肿瘤分期,按是否最终接受两个分期系统推荐的治疗方案分组。比较患者是否接受BCLC或HKLC分期推荐方案治疗对生存率的影响,并评估拒绝BCLC或HKLC推荐方案对预后可能产生的影响。结果接受BCLC推荐治疗方案的患者5年生存率显著高于拒绝推荐治疗方案的患者(48% vs. 30%, P<0.001)。与拒绝推荐治疗方案的患者相比,接受HKLC推荐治疗方案的患者亦有较高的5年生存率(41% vs. 29%, P<0.001)。对BCLC和HKLC交叉亚组分析,BCLC-B/HKLC-Ⅰ+Ⅱa+Ⅱb、BCLC-B/HKLC-Ⅲa+Ⅲb和BCLC-C/HKLC-Ⅲa+Ⅲb亚组中,接受手术切除的HCC患者显著高于接受TACE、索拉非尼或最佳支持治疗的患者5年生存率均较高(均P<0.05)。结论接受BCLC和HKLC分期系统推荐治疗方案可以提高HCC患者的存活率,但对于中晚期肝癌患者指导作用减弱。部分BCLC-B/HKLC-Ⅰ+Ⅱa+Ⅱb、BCLC-B/HKLC-Ⅲa+Ⅲb和BCLC-C/HKLC-Ⅲa+Ⅲb的患者通过积极的根治性治疗可以获得更好的生存。展开更多
基金Supported by National Natural Science Foundation of China(No.50772063)the Program for New Century Excellent Talents in University(No.NCET-06-0893)
文摘Different compositions of yttrium silicates coatings were deposited on SiC-C/C by plasma spraying and an outer borosilicate glass was applied on the yttrium silicates coatings surfaces. The structure of the multi-layer coatings was characterized by XRD and SEM analyses. High temperature oxidation behavior of the multi-layer coatings coated C/C composites was investigated. Results show that SiC/2SiO2 Y2O3/1.5SiO2 Y203/ SiO2 Y2O3/glass multi-layer coating has better high temperature oxidation resistance, protecting carbon/ carbon composites from oxidation at 1 773 K in air for 164 h with the weight loss of 1.65%. The oxidation weight loss of the coated C/C with time accorded with parabolic rule in the temperature range 1 573 K-1 873 K; and the corresponding oxidation activation energy of the coated carbon/carbon composites is 132.2 kJ/mol.
基金Funded by National Natural Science Foundation of China(No.51302160)Natural Science Foundation of Shaanxi Province(Nos.2014JQ6226 and 2014JQ6213)+1 种基金China Postdoctoral Science Foundation(No.2015M570808)the Doctoral Scientific Research Foundation of Shaanxi University of Science&Technology(No.BJ14-20)
文摘Nanocrystalline zirconia（ZrO） was synthesized using a microwave-hydrothermal process.The effect of pH on the crystallization of the ZrO2 powders was investigated.The phase and microstructure of ZrO2 powders were examined using X-ray diffraction（XRD）,Raman spectroscopy,and transmission electron microscopy（TEM）.Results show that pure m-ZrO2 can be obtained at low pH（pH＆lt;2）.Pure t-ZrO2 is formed at pH = 7 and 14.The size of the ZrO2 crystals is in the range of 8-26 nm and decreases with increasing pH.The formation of m-ZrO2 results from the precipitation of ZrO2 from solution.The t-ZrO2 is formed through the in-situ structural rearrangement of amorphous Zr（OH）xOy.The stabilization of t-ZrO2 is attributed to the small crystal size and the adsorption of hydroxy ions on the surfaces of the crystals.
文摘目的对比分析原发性肝癌患者及经肝动脉化疗栓塞术(TACE)治疗前后肠道菌群的多样性变化及菌群结构差异。方法选取2018年9月-2019年1月广西医科大学附属肿瘤医院原发性肝癌患者65例(其中接受TACE治疗20例),健康体检者27例。高通量16S rDNA测序方法分析患者便菌群结构,Anosim、LEf Se软件与R语言stats包分析菌群组间物种相对丰度、组间物种多样性、群落差异、进化分支等差异。符合正态性及方差齐的计量资料两组间比较采用t检验;不符合正态分布计量资料组间比较采用Kruskal-Wallis U检验;计数资料组间比较采用χ2检验。相关性分析采取Spearman秩相关性分析。结果在门水平,各组的最大优势菌均为拟杆菌门(Bacteroidetes)、厚壁菌门(Firmicutes),两者占比之和在健康组>90%,在原发性肝癌组及TACE治疗组中占比均>80%。拟杆菌门在健康组、原发性肝癌组、TACE治疗组占比分别为48.44%、44.96%、48.60%,厚壁菌门在各组占比分别为47.09%、38.15%、33.93%,拟杆菌门、厚壁菌门相对丰度在肝癌组均低于健康组;此外,变形菌门(Proteobacteria)及梭杆菌门(Fusobacteria)相对丰度在肝癌组及TACE治疗组中占比均高于健康组;其余菌门虽有所变化,但占比均<0.5%。健康组物种丰富度Observed species(264±47 vs 230±64,t=2.499,P=0.014)及ACE值(284.11±50.82 vs 252.96±67.58,t=2.158,P=0.034)均大于原发性肝癌组。Between组(原发性肝癌组+健康组)的秩较原发性肝癌组及健康组高,R>0,健康组及原发性肝癌组肠道菌群组间结构差异大于组内差异(P<0.05);Between组(TACE术前+术后)的秩低于TACE术前组,R<0,TACE治疗前与治疗后组内结构差异大于组间结构差异(P>0.05)。原发性肝癌患者肠内机会致病菌与Child-Turcotte-Pugh评分、TBil、ALT、AST存在相关性(r值分别为0.245、0.421、0.327、0.446,P值分别为0.049、<0.001、0.008、<0.001),潜在益生菌与Child-Turcotte-Pugh评分、TBil、Alb、ALT、AST存在相关性(r值分别为-0.314、-0.490、0.285、-0.374、-0.528,P值分别为0.011、<0.001、0.022、0.002、<0.001)。差异菌中的机会致病菌相对丰度随着肝功能Child-Pugh分级递增而增加,C级高于A级(Z=4.301,P=0.038)与B级(Z=4.063,P=0.044)。而潜在益生作用菌的相对丰度随着肝功能Child-Pugh分级的增加呈现减少趋势,C级低于A级(Z=3.882,P=0.049)。结论原发性肝癌患者与健康者肠道菌群多样性及结构不同,而原发性肝癌患者TACE治疗前后肠道菌群相近,TACE治疗对肠道菌群影响较小。肠道菌群失调与原发性肝癌临床分级存在关联,随着肝功能Child-Pugh等级的递增,菌群失调程度更为明显,潜在益生作用菌减少,而机会性致病菌增加。
文摘目的比较接受巴塞罗那临床肝癌分期系统(BCLC)或香港的分期系统(HKLC)推荐治疗方案对肝细胞肝癌(HCC)患者生存率的影响。方法回顾性分析436例初治肝癌患者的临床资料,根据HKLC和BCLC进行肿瘤分期,按是否最终接受两个分期系统推荐的治疗方案分组。比较患者是否接受BCLC或HKLC分期推荐方案治疗对生存率的影响,并评估拒绝BCLC或HKLC推荐方案对预后可能产生的影响。结果接受BCLC推荐治疗方案的患者5年生存率显著高于拒绝推荐治疗方案的患者(48% vs. 30%, P<0.001)。与拒绝推荐治疗方案的患者相比,接受HKLC推荐治疗方案的患者亦有较高的5年生存率(41% vs. 29%, P<0.001)。对BCLC和HKLC交叉亚组分析,BCLC-B/HKLC-Ⅰ+Ⅱa+Ⅱb、BCLC-B/HKLC-Ⅲa+Ⅲb和BCLC-C/HKLC-Ⅲa+Ⅲb亚组中,接受手术切除的HCC患者显著高于接受TACE、索拉非尼或最佳支持治疗的患者5年生存率均较高(均P<0.05)。结论接受BCLC和HKLC分期系统推荐治疗方案可以提高HCC患者的存活率,但对于中晚期肝癌患者指导作用减弱。部分BCLC-B/HKLC-Ⅰ+Ⅱa+Ⅱb、BCLC-B/HKLC-Ⅲa+Ⅲb和BCLC-C/HKLC-Ⅲa+Ⅲb的患者通过积极的根治性治疗可以获得更好的生存。
