A new solid acid catalyst,SO4^2-/TiO2 modified with tin,was prepared using a sol-gel method and its physicochemical properties were revealed by nitrogen adsorption-desorption,X-ray powder diffraction,scanning electron...A new solid acid catalyst,SO4^2-/TiO2 modified with tin,was prepared using a sol-gel method and its physicochemical properties were revealed by nitrogen adsorption-desorption,X-ray powder diffraction,scanning electron microscopy,Fourier transform infrared spectroscopy,infrared spectroscopy of adsorbed pyridine,temperature-programmed desorption of ammonia and thermal gravimetric analysis.The structure,acidity and thermal stability of the SO4^2-/TiO2-SnO2 catalyst were studied.Incorporating tin enlarged the specific surface area and decreased crystallite size of the SO4^2-/TiO2 catalyst.The total acid sites of the modified catalyst increased and Bronsted acid strength remarkably increased with increasing tin content.The decomposition temperature of sulfate radical in the modified catalyst was 100 ℃ greater and its mass loss was more than twice that of the SO4^2-/TiO2 catalyst.The SO4^2-/TiO2-SnO2 catalyst was designed to synthesize 1,6-hexanediol diacrylate by esterification of 1,6-hexanediol with crylic acid.The yield of 1,6-hexanediol diacrylate exceeded 87% under the optimal reaction conditions：crylic acid to 1,6-hexanediol molar ratio = 3.5,catalyst loading = 7%,reaction temperature = 130 ℃ and reaction time = 3 h.The modified catalyst exhibited excellent reusability and after 10 cycles the conversion of 1,6-hexanediol was above 81%.展开更多
目的:分析二肽基肽酶样蛋白-6(dipeptidyl-peptidase-like protein 6,DPPX)抗体相关脑炎患者的临床特征。方法:对2016年1月—2025年2月南京医科大学附属脑科医院就诊的5例DPPX抗体相关脑炎患者的临床特点、脑电图、磁共振成像(magnetic ...目的:分析二肽基肽酶样蛋白-6(dipeptidyl-peptidase-like protein 6,DPPX)抗体相关脑炎患者的临床特征。方法:对2016年1月—2025年2月南京医科大学附属脑科医院就诊的5例DPPX抗体相关脑炎患者的临床特点、脑电图、磁共振成像(magnetic resonance imaging,MRI)及预后进行回顾性研究。结果:5例均为男性,年龄14~56岁。5例患者血清DPPX抗体均为阳性,滴度1∶100~1∶10,其中1例合并血清接触蛋白关联蛋白2(contactin-associated protein-like 2,CASPR2)抗体阳性,4例脑脊液DPPX抗体阴性,1例滴度1∶1。2例患者以行为异常起病,1例以癫痫发作起病,1例以记忆力减退起病,1例合并CASPR2抗体阳性患者以多部位游走性肌阵挛起病。4例患者头颅MRI正常,1例头颅MRI提示双侧颞叶异常信号。以癫痫发作起病的患者脑电图背景重度异常合并左前颞尖波、尖慢波频发。结论:DPPX抗体相关脑炎临床表现具有异质性,早期诊断与鉴别困难,免疫治疗有效,易复发。展开更多
文摘A new solid acid catalyst,SO4^2-/TiO2 modified with tin,was prepared using a sol-gel method and its physicochemical properties were revealed by nitrogen adsorption-desorption,X-ray powder diffraction,scanning electron microscopy,Fourier transform infrared spectroscopy,infrared spectroscopy of adsorbed pyridine,temperature-programmed desorption of ammonia and thermal gravimetric analysis.The structure,acidity and thermal stability of the SO4^2-/TiO2-SnO2 catalyst were studied.Incorporating tin enlarged the specific surface area and decreased crystallite size of the SO4^2-/TiO2 catalyst.The total acid sites of the modified catalyst increased and Bronsted acid strength remarkably increased with increasing tin content.The decomposition temperature of sulfate radical in the modified catalyst was 100 ℃ greater and its mass loss was more than twice that of the SO4^2-/TiO2 catalyst.The SO4^2-/TiO2-SnO2 catalyst was designed to synthesize 1,6-hexanediol diacrylate by esterification of 1,6-hexanediol with crylic acid.The yield of 1,6-hexanediol diacrylate exceeded 87% under the optimal reaction conditions：crylic acid to 1,6-hexanediol molar ratio = 3.5,catalyst loading = 7%,reaction temperature = 130 ℃ and reaction time = 3 h.The modified catalyst exhibited excellent reusability and after 10 cycles the conversion of 1,6-hexanediol was above 81%.
