Sonoporation mediated by microbubbles is being extensively studied as a promising technology to facilitate gene/drug delivery to cells. However, the theoretical study regarding the mechanisms involved in sonoporation ...Sonoporation mediated by microbubbles is being extensively studied as a promising technology to facilitate gene/drug delivery to cells. However, the theoretical study regarding the mechanisms involved in sonoporation is still in its infancy.Microstreaming generated by pulsating microbubble near the cell membrane is regarded as one of the most important mechanisms in the sonoporation process. Here, based on an encapsulated microbubble dynamic model with considering nonlinear rheological effects of both shell elasticity and viscosity, the microstreaming velocity field and shear stress generated by an oscillating microbubble near the cell membrane are theoretically simulated. Some factors that might affect the behaviors of microstreaming are thoroughly investigated, including the distance between the bubble center and cell membrane（d）, shell elasticity（χ）, and shell viscosity（κ）. The results show that（i） the presence of cell membrane can result in asymmetric microstreaming velocity field, while the constrained effect of the membrane wall decays with increasing the bubble-cell distance;（ii） the bubble resonance frequency increases with the increase in d and χ, and the decrease in κ,although it is more dominated by the variation of shell elasticity; and（iii） the maximal microstreaming shear stress on the cell membrane increases rapidly with reducing the d, χ, and κ. The results suggest that microbubbles with softer and less viscous shell materials might be preferred to achieve more efficient sonoporation outcomes, and it is better to have bubbles located in the immediate vicinity of the cell membrane.展开更多
Analyzing undiluted whole human blood is a challenge due to its complex composition of hematopoietic cellular populations,nucleic acids,metabolites,and proteins.We present a novel multi-functional microfluidic acousti...Analyzing undiluted whole human blood is a challenge due to its complex composition of hematopoietic cellular populations,nucleic acids,metabolites,and proteins.We present a novel multi-functional microfluidic acoustic streaming platform that enables sorting,enrichment and in situ identification of cellular subsets from whole blood.This single device platform,based on lateral cavity acoustic transducers(LCAT),enables(1)the sorting of undiluted donor whole blood into its cellular subsets(platelets,RBCs,and WBCs),(2)the enrichment and retrieval of breast cancer cells(MCF-7)spiked in donor whole blood at rare cell relevant concentrations(10 mL^(−1)),and(3)on-chip immunofluorescent labeling for the detection of specific target cellular populations by their known marker expression patterns.Our approach thus demonstrates a compact system that integrates upstream sample processing with downstream separation/enrichment,to carry out multi-parametric cell analysis for blood-based diagnosis and liquid biopsy blood sampling.展开更多
呼气末二氧化碳监测是评估人体肺功能的重要手段,被广泛应用于临床急救、心肺复苏等领域。该文研制了一套微流式呼气末二氧化碳(CO_(2))监测系统,该系统采用一体化气路设计,进一步缩小了设备体积。其通过计算差压信号的均方根(root mean...呼气末二氧化碳监测是评估人体肺功能的重要手段,被广泛应用于临床急救、心肺复苏等领域。该文研制了一套微流式呼气末二氧化碳(CO_(2))监测系统,该系统采用一体化气路设计,进一步缩小了设备体积。其通过计算差压信号的均方根(root mean square,RMS)值调控气路流量,使系统可稳定运行于30 mL/min的流量状态。另外,该系统可以同时检测温度、压力等多种环境参数,实现对系统状态的监测和对气体参数的补偿。测试结果显示,该系统各项指标均满足相关标准要求,为后续的工程化应用奠定了良好的基础。展开更多
目的观察经鼻导管微旁流式呼气末二氧化碳分压(P ET CO2)监测能否预防经内镜逆行胰胆管造影术(ERCP)麻醉期间低氧血症的发生,并探讨其优缺点。方法选取我院肝胆外科2017-03/2019-05期间因胆道结石择期于非气管插管全身麻醉下行ERCP取石...目的观察经鼻导管微旁流式呼气末二氧化碳分压(P ET CO2)监测能否预防经内镜逆行胰胆管造影术(ERCP)麻醉期间低氧血症的发生,并探讨其优缺点。方法选取我院肝胆外科2017-03/2019-05期间因胆道结石择期于非气管插管全身麻醉下行ERCP取石的患者240例,年龄40~65岁,体质量45~75 kg,ASA分级Ⅱ或Ⅲ级,随机分为试验组(经鼻导管吸氧,采用经鼻导管微旁流式P ET CO2监测患者肺通气,n=120)和对照组(仅经鼻导管吸氧,n=120)。两组患者均于置入十二指肠镜前10 min开始泵注瑞芬太尼0.04μg/(kg·min),直至手术结束。置镜前2 min给予丙泊酚1.5~2.0 mg/kg,待睫毛反射消失后置入十二指肠镜,置镜成功后予丙泊酚3~5 mg/(kg·h)持续泵注直至手术结束。观察并比较2组患者低氧血症(SpO 2<90%)发生率、托下颌率、挤压胸廓辅助呼吸率、面罩加压给氧率。结果两组患者性别比、年龄、BMI、手术时间、苏醒时间、丙泊酚用量等一般资料比较,差异无统计学意义(P>0.05);试验组患者低氧血症发生率、面罩加压给氧率低于对照组,差异有统计学意义(P<0.05),试验组托下颌率、挤压胸廓辅助呼吸率高于对照组,差异有统计学意义。结论经鼻导管微旁流式P ET CO2监测可实时指导我们对患者进行托下颌、挤压胸廓辅助呼吸处理,降低ERCP麻醉期间低氧血症的发生率和面罩加压给氧率。展开更多
基金Projects supported by the National Basic Research Program,China(Grant No.2011CB707900)the National Natural Science Foundation of China(Grant Nos.81127901,81227004,81271589,11374155,11161120324,11074123,11174141,11274170,11104140,11474001,and 11474161)+1 种基金the National High Tech Research and Development Program,China(Grant No.2012AA022702)the Program for New Century Excellent Talents in University of Ministry of Education of China(Grant No.NCET-11-0236)
文摘Sonoporation mediated by microbubbles is being extensively studied as a promising technology to facilitate gene/drug delivery to cells. However, the theoretical study regarding the mechanisms involved in sonoporation is still in its infancy.Microstreaming generated by pulsating microbubble near the cell membrane is regarded as one of the most important mechanisms in the sonoporation process. Here, based on an encapsulated microbubble dynamic model with considering nonlinear rheological effects of both shell elasticity and viscosity, the microstreaming velocity field and shear stress generated by an oscillating microbubble near the cell membrane are theoretically simulated. Some factors that might affect the behaviors of microstreaming are thoroughly investigated, including the distance between the bubble center and cell membrane（d）, shell elasticity（χ）, and shell viscosity（κ）. The results show that（i） the presence of cell membrane can result in asymmetric microstreaming velocity field, while the constrained effect of the membrane wall decays with increasing the bubble-cell distance;（ii） the bubble resonance frequency increases with the increase in d and χ, and the decrease in κ,although it is more dominated by the variation of shell elasticity; and（iii） the maximal microstreaming shear stress on the cell membrane increases rapidly with reducing the d, χ, and κ. The results suggest that microbubbles with softer and less viscous shell materials might be preferred to achieve more efficient sonoporation outcomes, and it is better to have bubbles located in the immediate vicinity of the cell membrane.
基金This work was supported by the NSF Center for Advanced Design and Manufacturing of Integrated Microfluidics(CADMIM)(Award Nos.IIP-1362165 and IIP-1362048)Schlumberger Faculty for the Future Award(Award No.SF-202940)the National Cancer Institute of the National Institutes of Health under award no.P30CA062203.
文摘Analyzing undiluted whole human blood is a challenge due to its complex composition of hematopoietic cellular populations,nucleic acids,metabolites,and proteins.We present a novel multi-functional microfluidic acoustic streaming platform that enables sorting,enrichment and in situ identification of cellular subsets from whole blood.This single device platform,based on lateral cavity acoustic transducers(LCAT),enables(1)the sorting of undiluted donor whole blood into its cellular subsets(platelets,RBCs,and WBCs),(2)the enrichment and retrieval of breast cancer cells(MCF-7)spiked in donor whole blood at rare cell relevant concentrations(10 mL^(−1)),and(3)on-chip immunofluorescent labeling for the detection of specific target cellular populations by their known marker expression patterns.Our approach thus demonstrates a compact system that integrates upstream sample processing with downstream separation/enrichment,to carry out multi-parametric cell analysis for blood-based diagnosis and liquid biopsy blood sampling.
文摘呼气末二氧化碳监测是评估人体肺功能的重要手段,被广泛应用于临床急救、心肺复苏等领域。该文研制了一套微流式呼气末二氧化碳(CO_(2))监测系统,该系统采用一体化气路设计,进一步缩小了设备体积。其通过计算差压信号的均方根(root mean square,RMS)值调控气路流量,使系统可稳定运行于30 mL/min的流量状态。另外,该系统可以同时检测温度、压力等多种环境参数,实现对系统状态的监测和对气体参数的补偿。测试结果显示,该系统各项指标均满足相关标准要求,为后续的工程化应用奠定了良好的基础。
文摘目的观察经鼻导管微旁流式呼气末二氧化碳分压(P ET CO2)监测能否预防经内镜逆行胰胆管造影术(ERCP)麻醉期间低氧血症的发生,并探讨其优缺点。方法选取我院肝胆外科2017-03/2019-05期间因胆道结石择期于非气管插管全身麻醉下行ERCP取石的患者240例,年龄40~65岁,体质量45~75 kg,ASA分级Ⅱ或Ⅲ级,随机分为试验组(经鼻导管吸氧,采用经鼻导管微旁流式P ET CO2监测患者肺通气,n=120)和对照组(仅经鼻导管吸氧,n=120)。两组患者均于置入十二指肠镜前10 min开始泵注瑞芬太尼0.04μg/(kg·min),直至手术结束。置镜前2 min给予丙泊酚1.5~2.0 mg/kg,待睫毛反射消失后置入十二指肠镜,置镜成功后予丙泊酚3~5 mg/(kg·h)持续泵注直至手术结束。观察并比较2组患者低氧血症(SpO 2<90%)发生率、托下颌率、挤压胸廓辅助呼吸率、面罩加压给氧率。结果两组患者性别比、年龄、BMI、手术时间、苏醒时间、丙泊酚用量等一般资料比较,差异无统计学意义(P>0.05);试验组患者低氧血症发生率、面罩加压给氧率低于对照组,差异有统计学意义(P<0.05),试验组托下颌率、挤压胸廓辅助呼吸率高于对照组,差异有统计学意义。结论经鼻导管微旁流式P ET CO2监测可实时指导我们对患者进行托下颌、挤压胸廓辅助呼吸处理,降低ERCP麻醉期间低氧血症的发生率和面罩加压给氧率。
