Cancer metastasis is the leading cause of death in cancer patients worldwide and one of the major challenges in treating cancer.Circulating tumor cells(CTCs)play a pivotal role in cancer metastasis.However,the content...Cancer metastasis is the leading cause of death in cancer patients worldwide and one of the major challenges in treating cancer.Circulating tumor cells(CTCs)play a pivotal role in cancer metastasis.However,the content of CTCs in peripheral blood is minimal,so the detection of CTCs in real samples is extremely challenging.Therefore,efficient enrichment and early detection of CTCs are essential to achieve timely diagnosis of diseases.In this work,we constructed an innovative and sensitive single-nanoparticle collision electrochemistry(SNCE)biosensor for the detection of MCF-7 cells(human breast cancer cells)by immunomagnetic separation technique and liposome signal amplification strategy.Liposomes embedded with platinum nanoparticles(Pt NPs)were used as signal probes,and homemade gold ultramicroelectrodes(Au UME)were used as the working electrodes.The effective collision between Pt NPs and UME would produce distinguishable step-type current.MCF-7 cells were accurately quantified according to the relationship between cell concentration and collision frequency(the number of step-type currents generated per unit time),realizing highly sensitive and specific detection of MCF-7 cells.The SNCE biosensor has a linear range of 10 cells·mL^(-1)to 10^(5) cells·mL^(-1)with a detection limit as low as 5 cells·mL^(-1).In addition,the successful detection of MCF-7 cells in complex samples showed that the SNCE biosensors have great potential for patient sample detection.展开更多
Pressure fluctuations contribute to the instability of separation process in air dense medium fluidized bed, which provides a high motivation for further study of underlying mechanisms. Reasons for generation and prop...Pressure fluctuations contribute to the instability of separation process in air dense medium fluidized bed, which provides a high motivation for further study of underlying mechanisms. Reasons for generation and propagation of pressure fluctuations in the air dense medium fluidized bed have been discussed.Drift rate and collision rate of particles were employed to deduce the correlation between voidage and pressure fluctuations. Simultaneously, a dynamic pressure fluctuation measuring and analysis system was established. Based on frequency domain analysis and wavelet analysis, collected signals were disassembled and analyzed. Results show gradually intensive motion of particles increases magnitudes of signal components with lower frequencies. As a result of violent particle motion, the magnitude of real pressure signal's frequency experienced an increase as air velocity increased moderately. Wavelet analysis keeps edge features of the real signal and eliminates the noise efficaciously. The frequency of denoised signal is closed to that of pressure signal identified in frequency domain analysis.展开更多
基金supported by the National Natural Science Foundation of China(Nos.22274037,22376055 and 21904032)the Natural Science Foundation of Hubei Province(2022CFB383)。
文摘Cancer metastasis is the leading cause of death in cancer patients worldwide and one of the major challenges in treating cancer.Circulating tumor cells(CTCs)play a pivotal role in cancer metastasis.However,the content of CTCs in peripheral blood is minimal,so the detection of CTCs in real samples is extremely challenging.Therefore,efficient enrichment and early detection of CTCs are essential to achieve timely diagnosis of diseases.In this work,we constructed an innovative and sensitive single-nanoparticle collision electrochemistry(SNCE)biosensor for the detection of MCF-7 cells(human breast cancer cells)by immunomagnetic separation technique and liposome signal amplification strategy.Liposomes embedded with platinum nanoparticles(Pt NPs)were used as signal probes,and homemade gold ultramicroelectrodes(Au UME)were used as the working electrodes.The effective collision between Pt NPs and UME would produce distinguishable step-type current.MCF-7 cells were accurately quantified according to the relationship between cell concentration and collision frequency(the number of step-type currents generated per unit time),realizing highly sensitive and specific detection of MCF-7 cells.The SNCE biosensor has a linear range of 10 cells·mL^(-1)to 10^(5) cells·mL^(-1)with a detection limit as low as 5 cells·mL^(-1).In addition,the successful detection of MCF-7 cells in complex samples showed that the SNCE biosensors have great potential for patient sample detection.
基金support by the Natural Science Foundation of Jiangsu Province of China (No. BK20160266)the National Natural Science Foundation of China (Nos. 51704287 and U1508210)the Priority Academic Program Development of Jiangsu Higher Education Institutions of China
文摘Pressure fluctuations contribute to the instability of separation process in air dense medium fluidized bed, which provides a high motivation for further study of underlying mechanisms. Reasons for generation and propagation of pressure fluctuations in the air dense medium fluidized bed have been discussed.Drift rate and collision rate of particles were employed to deduce the correlation between voidage and pressure fluctuations. Simultaneously, a dynamic pressure fluctuation measuring and analysis system was established. Based on frequency domain analysis and wavelet analysis, collected signals were disassembled and analyzed. Results show gradually intensive motion of particles increases magnitudes of signal components with lower frequencies. As a result of violent particle motion, the magnitude of real pressure signal's frequency experienced an increase as air velocity increased moderately. Wavelet analysis keeps edge features of the real signal and eliminates the noise efficaciously. The frequency of denoised signal is closed to that of pressure signal identified in frequency domain analysis.
