To mitigate the severe abrasion damage caused by high-velocity water flow in hydraulic engineering applications in Xizang, China, this study systematically optimized key mix design parameters, including aggregate grad...To mitigate the severe abrasion damage caused by high-velocity water flow in hydraulic engineering applications in Xizang, China, this study systematically optimized key mix design parameters, including aggregate gradation, sand ratio, fly ash content, and superplasticizer dosage. Based on the optimized mix, the combined effects of an abrasion-resistance enhancement admixture (AEA) and silica fume (SF) on the abrasion resistance of self-compacting concrete (SCC) were examined. The results demonstrated that the appropriate incorporation of AEA and SF significantly improved the abrasion resistance of SCC without compromising its workability. The proposed mix design not only achieves superior abrasion resistance but also provides practical guidance for the material design and engineering application of durable hydraulic concrete in harsh environments. Future research will focus on comprehensive durability assessments by simulating extreme hydraulic conditions, including sustained exposure to high-velocity sediment-laden flows, repeated freeze-thaw cycles, and corrosive salt spray environments, to thoroughly evaluate the long-term performance evolution of abrasion-resistant self-compacting concrete. Meanwhile, advanced microstructural analytical methods should be applied toelaborate the synergistic mechanisms of abrasion-resistance enhancement admixture (AEA), silica fume (SF), and steel fibers in altering the hydration product formation, optimizing the distribution of pore structure, and strengthening interfacial transition zones, to establish a solid scientific foundation for the development of high-performance composite materials.展开更多
肉毒素(botulinum toxin,BTX)是由肉毒梭状芽孢杆菌产生的毒性蛋白质,最先应用于治疗斜视[1]。1989年美国食品药品管理局正式批准A型肉毒毒素(botulinum toxin type A,BTX-A)最早应用于治疗斜视和面部肌肉痉挛性疾病,取得良好效果。近年...肉毒素(botulinum toxin,BTX)是由肉毒梭状芽孢杆菌产生的毒性蛋白质,最先应用于治疗斜视[1]。1989年美国食品药品管理局正式批准A型肉毒毒素(botulinum toxin type A,BTX-A)最早应用于治疗斜视和面部肌肉痉挛性疾病,取得良好效果。近年来A型肉毒素也用于脑卒中后四肢痉挛的治疗,治疗剂量的BTX-A被认为是安全有效的,临床上使用BTX-A导致严重全身肌肉软弱无力、呼吸抑制等严重中毒反应极为罕见,一旦出现,救治不及时可引起患者严重后果,危及生命。本文对我院收治l例因治疗脑卒中后上肢痉挛注射BTX-A后导致严重呼吸抑制患者进行分析,并结合国内外相关文献进行复习讨论,以提高临床对注射BTX-A后可能出现呼吸功能抑制的认识。展开更多
基金supported by the National Natural Science Foundation of China(No.52179137).
文摘To mitigate the severe abrasion damage caused by high-velocity water flow in hydraulic engineering applications in Xizang, China, this study systematically optimized key mix design parameters, including aggregate gradation, sand ratio, fly ash content, and superplasticizer dosage. Based on the optimized mix, the combined effects of an abrasion-resistance enhancement admixture (AEA) and silica fume (SF) on the abrasion resistance of self-compacting concrete (SCC) were examined. The results demonstrated that the appropriate incorporation of AEA and SF significantly improved the abrasion resistance of SCC without compromising its workability. The proposed mix design not only achieves superior abrasion resistance but also provides practical guidance for the material design and engineering application of durable hydraulic concrete in harsh environments. Future research will focus on comprehensive durability assessments by simulating extreme hydraulic conditions, including sustained exposure to high-velocity sediment-laden flows, repeated freeze-thaw cycles, and corrosive salt spray environments, to thoroughly evaluate the long-term performance evolution of abrasion-resistant self-compacting concrete. Meanwhile, advanced microstructural analytical methods should be applied toelaborate the synergistic mechanisms of abrasion-resistance enhancement admixture (AEA), silica fume (SF), and steel fibers in altering the hydration product formation, optimizing the distribution of pore structure, and strengthening interfacial transition zones, to establish a solid scientific foundation for the development of high-performance composite materials.
文摘肉毒素(botulinum toxin,BTX)是由肉毒梭状芽孢杆菌产生的毒性蛋白质,最先应用于治疗斜视[1]。1989年美国食品药品管理局正式批准A型肉毒毒素(botulinum toxin type A,BTX-A)最早应用于治疗斜视和面部肌肉痉挛性疾病,取得良好效果。近年来A型肉毒素也用于脑卒中后四肢痉挛的治疗,治疗剂量的BTX-A被认为是安全有效的,临床上使用BTX-A导致严重全身肌肉软弱无力、呼吸抑制等严重中毒反应极为罕见,一旦出现,救治不及时可引起患者严重后果,危及生命。本文对我院收治l例因治疗脑卒中后上肢痉挛注射BTX-A后导致严重呼吸抑制患者进行分析,并结合国内外相关文献进行复习讨论,以提高临床对注射BTX-A后可能出现呼吸功能抑制的认识。
