Quantitative gene expression analysis plays an important role in identifying differentially expressed genes in various pathological states, gene expression regulation and co-regulation, shedding light on gene function...Quantitative gene expression analysis plays an important role in identifying differentially expressed genes in various pathological states, gene expression regulation and co-regulation, shedding light on gene functions. Although microarray is widely used as a powerful tool in this regard, it is suboptimal quantitatively and unable to detect unknown gene variants. Here we demonstrated effective detection of differential expression and co-regulation of certain genes by expressed sequence tag analysis using a selected subset of cDNA libraries. We discussed the issues of sequencing depth and library preparation, and propose that increased sequencing depth and improved preparation procedures may allow detection of many expression features for less abundant gene variants. With the reduction of sequencing cost and the emerging of new generation sequencing technology, in-depth sequencing of cDNA pools or libraries may represent a better and powerful tool in gene expression profiling and cancer biomarker detection. We also propose using sequence-specific subtraction to remove hundreds of the most abundant housekeeping genes to increase sequencing depth without affecting relative expression ratio of other genes, as transcripts from as few as 300 most abundantly expressed genes constitute about 20% of the total transcriptome. In-depth sequencing also represents a unique advantage of detecting unknown forms of transcripts, such as alternative splicing variants, fusion genes, and regulatory RNAs, as well as detecting mutations and polymorphisms that may play important roles in disease pathogenesis.展开更多
Framing photography provides a high temporal resolution and minimizes crosstalk between adjacent frames,making it an indispensable tool for recording ultrafast phenomena.To date,various ultrafast framing photography t...Framing photography provides a high temporal resolution and minimizes crosstalk between adjacent frames,making it an indispensable tool for recording ultrafast phenomena.To date,various ultrafast framing photography techniques have been developed.However,simultaneously achieving large sequence depth,high image quality,ultrashort exposure time,and flexible frame interval remains a significant challenge.Herein,we present a spatiotemporal shearing-based ultrafast framing photography,termed STS-UFP,designed to address this challenge.STS-UFP employs an adjustable ultrashort laser pulse train with a spectrum shuttle to illuminate the dynamic scenes for extracting the transient information and records discrete frames using a streak camera via spatiotemporal shearing.Based on its unique design,STS-UFP achieves high-quality ultrafast imaging with a sequence depth of up to 16 frames and frame intervals ranging from hundreds of picoseconds to nanoseconds,while maintaining an extremely short(picosecond)exposure time.The exceptional performance of STS-UFP is demonstrated through experimental observations of femtosecond laser-induced plasma and shockwave in water,femtosecond laser ablation in biological tissue,and femtosecond laser-induced shockwave on a silicon surface.Given its remarkable imaging capabilities,STS-UFP serves as a powerful tool for precisely observing ultrafast dynamics and holds significant potential for advancing studies of ultrafast phenomena.展开更多
Ultrahigh-speed imaging is an essential tool for capturing fast dynamic scenes across various fields.Despite the development of numerous technical strategies,achieving ultrahigh-speed imaging with high spatiotemporal ...Ultrahigh-speed imaging is an essential tool for capturing fast dynamic scenes across various fields.Despite the development of numerous technical strategies,achieving ultrahigh-speed imaging with high spatiotemporal resolution and substantial sequence depth remains a significant challenge.To address this issue,we present a compressive ultrahigh-speed imaging technique based on acousto-optic frequency sweeping,termed AOFSCUSI.AOFS-CUSI employs light with rapidly time-varying spectra generated by acousto-optic modulation to illuminate dynamic scenes,records spatio-spectral information using snapshot compressive imaging,and ultimately reconstructs spatiotemporal information through time-spectrum mapping.This technique achieves a temporal resolution of 1.55 million frames per second,a spatial resolution of 228 lp/mm,and a sequence depth of 31 in a single shot.We experimentally validate the superior performance of AOFS-CUSI by capturing the rotation of an optical chopper,the movement of microspheres in a microchannel,and the femtosecondlaser-induced cavitation bubble dynamics.By eliminating the requirement for ultrafast laser sources and simultaneously extending the temporal window,AOFS-CUSI offers an excellent solution for recording and analyzing various fast dynamics,presenting significant potential for applications in both fundamental and applied research.展开更多
文摘Quantitative gene expression analysis plays an important role in identifying differentially expressed genes in various pathological states, gene expression regulation and co-regulation, shedding light on gene functions. Although microarray is widely used as a powerful tool in this regard, it is suboptimal quantitatively and unable to detect unknown gene variants. Here we demonstrated effective detection of differential expression and co-regulation of certain genes by expressed sequence tag analysis using a selected subset of cDNA libraries. We discussed the issues of sequencing depth and library preparation, and propose that increased sequencing depth and improved preparation procedures may allow detection of many expression features for less abundant gene variants. With the reduction of sequencing cost and the emerging of new generation sequencing technology, in-depth sequencing of cDNA pools or libraries may represent a better and powerful tool in gene expression profiling and cancer biomarker detection. We also propose using sequence-specific subtraction to remove hundreds of the most abundant housekeeping genes to increase sequencing depth without affecting relative expression ratio of other genes, as transcripts from as few as 300 most abundantly expressed genes constitute about 20% of the total transcriptome. In-depth sequencing also represents a unique advantage of detecting unknown forms of transcripts, such as alternative splicing variants, fusion genes, and regulatory RNAs, as well as detecting mutations and polymorphisms that may play important roles in disease pathogenesis.
基金National Natural Science Foundation of China(12325408,12274129,12274139,12374274,62175066,92150102,12474404,12304338,12471368,62475070)Fundamental Research Funds for the Central Universities。
文摘Framing photography provides a high temporal resolution and minimizes crosstalk between adjacent frames,making it an indispensable tool for recording ultrafast phenomena.To date,various ultrafast framing photography techniques have been developed.However,simultaneously achieving large sequence depth,high image quality,ultrashort exposure time,and flexible frame interval remains a significant challenge.Herein,we present a spatiotemporal shearing-based ultrafast framing photography,termed STS-UFP,designed to address this challenge.STS-UFP employs an adjustable ultrashort laser pulse train with a spectrum shuttle to illuminate the dynamic scenes for extracting the transient information and records discrete frames using a streak camera via spatiotemporal shearing.Based on its unique design,STS-UFP achieves high-quality ultrafast imaging with a sequence depth of up to 16 frames and frame intervals ranging from hundreds of picoseconds to nanoseconds,while maintaining an extremely short(picosecond)exposure time.The exceptional performance of STS-UFP is demonstrated through experimental observations of femtosecond laser-induced plasma and shockwave in water,femtosecond laser ablation in biological tissue,and femtosecond laser-induced shockwave on a silicon surface.Given its remarkable imaging capabilities,STS-UFP serves as a powerful tool for precisely observing ultrafast dynamics and holds significant potential for advancing studies of ultrafast phenomena.
基金National Natural Science Foundation of China(12325408,12274129,12374274,12274139,62175066,92150102,62475070,12474404,12471368)Shanghai Municipal Education Commission(2024AI01007)+1 种基金Open Fund of Guangdong Provincial Key Laboratory of Nanophotonic Manipulation(202504)Guangdong ST Program(2023B1212010008).
文摘Ultrahigh-speed imaging is an essential tool for capturing fast dynamic scenes across various fields.Despite the development of numerous technical strategies,achieving ultrahigh-speed imaging with high spatiotemporal resolution and substantial sequence depth remains a significant challenge.To address this issue,we present a compressive ultrahigh-speed imaging technique based on acousto-optic frequency sweeping,termed AOFSCUSI.AOFS-CUSI employs light with rapidly time-varying spectra generated by acousto-optic modulation to illuminate dynamic scenes,records spatio-spectral information using snapshot compressive imaging,and ultimately reconstructs spatiotemporal information through time-spectrum mapping.This technique achieves a temporal resolution of 1.55 million frames per second,a spatial resolution of 228 lp/mm,and a sequence depth of 31 in a single shot.We experimentally validate the superior performance of AOFS-CUSI by capturing the rotation of an optical chopper,the movement of microspheres in a microchannel,and the femtosecondlaser-induced cavitation bubble dynamics.By eliminating the requirement for ultrafast laser sources and simultaneously extending the temporal window,AOFS-CUSI offers an excellent solution for recording and analyzing various fast dynamics,presenting significant potential for applications in both fundamental and applied research.
