Gravity-driven membrane(GDM)systems have been well developed previously;however,impacts of driving(i.e.,transmembrane)pressure on their performance received little attention,which may infuence GDM performance.In this ...Gravity-driven membrane(GDM)systems have been well developed previously;however,impacts of driving(i.e.,transmembrane)pressure on their performance received little attention,which may infuence GDM performance.In this study,we evaluated 4 GDM systems via altering the transmembrane pressure from 50 mbar to 150 mbar with 2 groups,treating surface water in Beijing,China.Results showed that less driving pressure was more favorable.Specifically,compared to groups(150 mbar),groups under a pressure of 50 mbar were found to have greater normalized permeability and lower total resistance.During the whole operation period,the quality of effuents was gradually improved.For example,the removal efficiency of UV254was significantly improved;particularly,under low driving pressure,the removal efficiency of UV254in PES GDM system increased by 11.91%,as compared to the corresponding system under high driving pressure.This observation was consistent with the reduction on disinfection by-products(DBPs)formation potential;groups under 50 mbar achieved better DBPs potential control,indicating the advantages of lower driving pressure.Biofilms were analyzed and responsible for these differences,and distinct distributions of bacteria communities of two GDM systems under 50 and 150 mbar may be responsible for various humic-like substances removal efficiency.Overall,GDM systems under less pressure should be considered and expected to provide suggestions on the design of GDM systems in real applications.展开更多
The quantification of immune cell subpopulations in blood is important for the diagnosis,prognosis and management of various diseases and medical conditions.Flow cytometry is currently the gold standard technique for ...The quantification of immune cell subpopulations in blood is important for the diagnosis,prognosis and management of various diseases and medical conditions.Flow cytometry is currently the gold standard technique for cell quantification;however,it is laborious,time-consuming and relies on bulky/expensive instrumentation,limiting its use to laboratories in high-resource settings.Microfluidic cytometers offering enhanced portability have been developed that are capable of rapid cell quantification;however,these platforms involve tedious sample preparation and processing protocols and/or require the use of specialized/expensive instrumentation for flow control and cell detection.Here,we report an artificial intelligence-enabled microfluidic cytometer for rapid CD4^(+)T cell quantification in whole blood requiring minimal sample preparation and instrumentation.CD4^(+)T cells in blood are labeled with anti-CD4 antibody-coated microbeads,which are driven through a microfluidic chip via gravity-driven slug flow,enabling pump-free operation.A video of the sample flowing in the chip is recorded using a microscope camera,which is analyzed using a convolutional neural network-based model that is trained to detect bead-labeled cells in the blood flow.The functionality of this platform was evaluated by analyzing fingerprick blood samples obtained from healthy donors,which revealed its ability to quantify CD4^(+)T cells with similar accuracy as flow cytometry(<10%deviation between both methods)while being at least 4×faster,less expensive,and simpler to operate.We envision that this platform can be readily modified to quantify other cell subpopulations in blood by using beads coated with different antibodies,making it a promising tool for performing cell count measurements outside of laboratories and in low-resource settings.展开更多
Fluid flow is a ubiquitous aspect of microfluidic systems.Gravity-driven flow is one microfluidic flow initiation and maintenance mechanism that is appealing because it is simple,requires no external power source,and ...Fluid flow is a ubiquitous aspect of microfluidic systems.Gravity-driven flow is one microfluidic flow initiation and maintenance mechanism that is appealing because it is simple,requires no external power source,and is easy to use.However,the driving forces created by hydraulic head differences gradually decrease during operation,resulting in decreasing flow rates that are undesirable in many microfluidic applications such as perfusion culture,droplet microfluidics,etc.Existing methods to maintain a constant gravity-driven flow either require additional control equipment,involve complex fabrication or operation,are incompatible with miniaturization,or introduce interfaces that lack robustness.Here we tackled those problems by introducing a 3D-printed compact hydraulic head auto-regulating module that automatically maintains a constant fluid level at the microfluidic inlet port without human intervention.Our module successfully maintained a constant hydraulic head for more than 24 h,with the operation time solely limited by the reservoir capacity.A comparison with the conventional gravity-driven flow demonstrated our device’s capability to produce a more stable flow over the perfusion period.Overall,our module creates a simple,robust solution to produce a stable flow rate in gravity-driven flow systems.The compactness of the design allows easy parallelization and compatibility with high-throughput applications,and the biocompatibility of the materials enables the device’s use with life science applications.展开更多
基金supported by the National Natural Science Foundation of China (No.52200026)。
文摘Gravity-driven membrane(GDM)systems have been well developed previously;however,impacts of driving(i.e.,transmembrane)pressure on their performance received little attention,which may infuence GDM performance.In this study,we evaluated 4 GDM systems via altering the transmembrane pressure from 50 mbar to 150 mbar with 2 groups,treating surface water in Beijing,China.Results showed that less driving pressure was more favorable.Specifically,compared to groups(150 mbar),groups under a pressure of 50 mbar were found to have greater normalized permeability and lower total resistance.During the whole operation period,the quality of effuents was gradually improved.For example,the removal efficiency of UV254was significantly improved;particularly,under low driving pressure,the removal efficiency of UV254in PES GDM system increased by 11.91%,as compared to the corresponding system under high driving pressure.This observation was consistent with the reduction on disinfection by-products(DBPs)formation potential;groups under 50 mbar achieved better DBPs potential control,indicating the advantages of lower driving pressure.Biofilms were analyzed and responsible for these differences,and distinct distributions of bacteria communities of two GDM systems under 50 and 150 mbar may be responsible for various humic-like substances removal efficiency.Overall,GDM systems under less pressure should be considered and expected to provide suggestions on the design of GDM systems in real applications.
基金supported in part by the National Institutes of Health(R21CA283852)a Rice University COVID-19 Research Award(U50807).
文摘The quantification of immune cell subpopulations in blood is important for the diagnosis,prognosis and management of various diseases and medical conditions.Flow cytometry is currently the gold standard technique for cell quantification;however,it is laborious,time-consuming and relies on bulky/expensive instrumentation,limiting its use to laboratories in high-resource settings.Microfluidic cytometers offering enhanced portability have been developed that are capable of rapid cell quantification;however,these platforms involve tedious sample preparation and processing protocols and/or require the use of specialized/expensive instrumentation for flow control and cell detection.Here,we report an artificial intelligence-enabled microfluidic cytometer for rapid CD4^(+)T cell quantification in whole blood requiring minimal sample preparation and instrumentation.CD4^(+)T cells in blood are labeled with anti-CD4 antibody-coated microbeads,which are driven through a microfluidic chip via gravity-driven slug flow,enabling pump-free operation.A video of the sample flowing in the chip is recorded using a microscope camera,which is analyzed using a convolutional neural network-based model that is trained to detect bead-labeled cells in the blood flow.The functionality of this platform was evaluated by analyzing fingerprick blood samples obtained from healthy donors,which revealed its ability to quantify CD4^(+)T cells with similar accuracy as flow cytometry(<10%deviation between both methods)while being at least 4×faster,less expensive,and simpler to operate.We envision that this platform can be readily modified to quantify other cell subpopulations in blood by using beads coated with different antibodies,making it a promising tool for performing cell count measurements outside of laboratories and in low-resource settings.
基金supported by the NIH award 1R21NS120088the MIT School of Engineering Postdoctoral Fellowship Program for Engineering Excellence.
文摘Fluid flow is a ubiquitous aspect of microfluidic systems.Gravity-driven flow is one microfluidic flow initiation and maintenance mechanism that is appealing because it is simple,requires no external power source,and is easy to use.However,the driving forces created by hydraulic head differences gradually decrease during operation,resulting in decreasing flow rates that are undesirable in many microfluidic applications such as perfusion culture,droplet microfluidics,etc.Existing methods to maintain a constant gravity-driven flow either require additional control equipment,involve complex fabrication or operation,are incompatible with miniaturization,or introduce interfaces that lack robustness.Here we tackled those problems by introducing a 3D-printed compact hydraulic head auto-regulating module that automatically maintains a constant fluid level at the microfluidic inlet port without human intervention.Our module successfully maintained a constant hydraulic head for more than 24 h,with the operation time solely limited by the reservoir capacity.A comparison with the conventional gravity-driven flow demonstrated our device’s capability to produce a more stable flow over the perfusion period.Overall,our module creates a simple,robust solution to produce a stable flow rate in gravity-driven flow systems.The compactness of the design allows easy parallelization and compatibility with high-throughput applications,and the biocompatibility of the materials enables the device’s use with life science applications.
