Nanomaterials provide an ideal platform for biomolecular display due to their dimensions approach the molecular scale,facilitating binding behavior akin to that observed in solution-based processes.DNA nanoprobes hold...Nanomaterials provide an ideal platform for biomolecular display due to their dimensions approach the molecular scale,facilitating binding behavior akin to that observed in solution-based processes.DNA nanoprobes hold great promise as miniature detectives capable of detecting mi RNAs within cells.However,current nanoprobes face a challenge in achieving the required precision for accurate miRNA detection,particularly within the intricate confines of the cellular microenvironment,due to interference with biological autofluorescence,off-target effects,and a lack of spatiotemporal control.Here,we have designed a dual-stimuli responsive DNA tracker,synergistically utilizing specific intracellular cues and external triggers,which enables spatiotemporal-controlled and precise detection and imaging of miRNAs"on demand".The tracker,which combines zeolitic imidazolate framework-67(ZIF-67)and unique hairpin DNA structures,effectively anchored onto the ZIF-67 through electrostatic interactions,remains in a dormant state until activated by abundant cellular ATP,resulting in the release of the hairpin structures that include a PC linker incorporated into the loop region.Subsequent irradiation triggers specific recognition of the target miRNA.The newly developed HP-PC-BT@ZIF-67 tracker demonstrates precise spatiotemporal mi RNA detection and exhibits excellent biocompatibility,enabling specific mi RNA recognition"on demand"within cancer cells.This research presents a reliable mi RNA imaging platform in the intricate cellular environment,opening up the possibilities for precise biomedical analysis and disease diagnosis.展开更多
Shaking table tests are widely used to evaluate seismic effects on railway structures,but accurately measuring rail displacement remains a significant challenge owing to the nonlinear characteristics of large displace...Shaking table tests are widely used to evaluate seismic effects on railway structures,but accurately measuring rail displacement remains a significant challenge owing to the nonlinear characteristics of large displacements,ambient noise interference,and limitations in displacement meter installation.In this paper,a novel method that integrates the Kanade-Lucas-Tomasi(KLT)feature tracker with an extended Kalman filter(EKF)is presented for measuring rail displacement during shaking table tests.The method employs KLT feature tracker and a random sample consensus algorithm to extract and track key feature points,while EKF optimally estimates dynamic states by accounting for system noise and observation errors.Shaking table test results demonstrate that the proposed method achieves an acceleration root mean square error of 0.300 m/s^(2)and a correlation with accelerometer data exceeding 99.7%,significantly outper-forming the original KLT approach.This innovative method provides a more efficient and reliable solution for measuring rail displacement under large nonlinear vibrations.展开更多
为探究池塘养殖凡纳对虾肠道微生物与环境微生物之间的关系,揭示养殖过程中微生物的变化规律,采用16S r DNA高通量测序和生物信息学方法,对水体、沉积物和对虾肠道微生物的组成、变化、功能及群落构建机制进行了分析研究。结果显示,凡...为探究池塘养殖凡纳对虾肠道微生物与环境微生物之间的关系,揭示养殖过程中微生物的变化规律,采用16S r DNA高通量测序和生物信息学方法,对水体、沉积物和对虾肠道微生物的组成、变化、功能及群落构建机制进行了分析研究。结果显示,凡纳对虾养殖池塘水体、沉积物和对虾肠道微生物存在差异且处于动态变化之中,水体中的优势微生物为变形菌门(Proteobacteria)和蓝细菌门(Cyanobacteria),沉积物中主要为拟杆菌门(Bacteroidota)和变形菌门,凡纳对虾肠道中主要为变形菌门和厚壁菌门(Firmicutes)。微生物来源(Source Tracker)分析表明,沉积物与肠道微生物的交换数量高于水体与肠道微生物的交换数量。群落构建机制分析结果显示,确定性过程主导水体微生物群落的构建,水体酸碱度和化学需氧量(COD)是最主要的环境因子;沉积物和肠道中的微生物群落由确定性过程与随机过程共同决定。结果表明,凡纳对虾肠道微生物的组成和功能受到环境微生物和环境因子等多种因素影响。展开更多
基金supported by the National Natural Science Foundation of China(Nos.21904095,22004089)Peiyang Talents Project of Tianjin University+1 种基金Young Thousand Talented ProgramProgram of Tianjin Science and Technology Major Project and Engineering(No.19ZXYXSY00090)。
文摘Nanomaterials provide an ideal platform for biomolecular display due to their dimensions approach the molecular scale,facilitating binding behavior akin to that observed in solution-based processes.DNA nanoprobes hold great promise as miniature detectives capable of detecting mi RNAs within cells.However,current nanoprobes face a challenge in achieving the required precision for accurate miRNA detection,particularly within the intricate confines of the cellular microenvironment,due to interference with biological autofluorescence,off-target effects,and a lack of spatiotemporal control.Here,we have designed a dual-stimuli responsive DNA tracker,synergistically utilizing specific intracellular cues and external triggers,which enables spatiotemporal-controlled and precise detection and imaging of miRNAs"on demand".The tracker,which combines zeolitic imidazolate framework-67(ZIF-67)and unique hairpin DNA structures,effectively anchored onto the ZIF-67 through electrostatic interactions,remains in a dormant state until activated by abundant cellular ATP,resulting in the release of the hairpin structures that include a PC linker incorporated into the loop region.Subsequent irradiation triggers specific recognition of the target miRNA.The newly developed HP-PC-BT@ZIF-67 tracker demonstrates precise spatiotemporal mi RNA detection and exhibits excellent biocompatibility,enabling specific mi RNA recognition"on demand"within cancer cells.This research presents a reliable mi RNA imaging platform in the intricate cellular environment,opening up the possibilities for precise biomedical analysis and disease diagnosis.
基金The National Key Research and Development Program of China(No.2021YFB2600600,2021YFB2600601)the National Natural Science Foundation of China(No.52408456)+2 种基金China Postdoctoral Science Foundation(No.2022M720533)College Students’Innovative Entrepreneurial Training Plan Program(No.202410710009)Key Research and Development Program of Shaanxi,China(No.2024SF-YBXM-659).
文摘Shaking table tests are widely used to evaluate seismic effects on railway structures,but accurately measuring rail displacement remains a significant challenge owing to the nonlinear characteristics of large displacements,ambient noise interference,and limitations in displacement meter installation.In this paper,a novel method that integrates the Kanade-Lucas-Tomasi(KLT)feature tracker with an extended Kalman filter(EKF)is presented for measuring rail displacement during shaking table tests.The method employs KLT feature tracker and a random sample consensus algorithm to extract and track key feature points,while EKF optimally estimates dynamic states by accounting for system noise and observation errors.Shaking table test results demonstrate that the proposed method achieves an acceleration root mean square error of 0.300 m/s^(2)and a correlation with accelerometer data exceeding 99.7%,significantly outper-forming the original KLT approach.This innovative method provides a more efficient and reliable solution for measuring rail displacement under large nonlinear vibrations.
文摘为探究池塘养殖凡纳对虾肠道微生物与环境微生物之间的关系,揭示养殖过程中微生物的变化规律,采用16S r DNA高通量测序和生物信息学方法,对水体、沉积物和对虾肠道微生物的组成、变化、功能及群落构建机制进行了分析研究。结果显示,凡纳对虾养殖池塘水体、沉积物和对虾肠道微生物存在差异且处于动态变化之中,水体中的优势微生物为变形菌门(Proteobacteria)和蓝细菌门(Cyanobacteria),沉积物中主要为拟杆菌门(Bacteroidota)和变形菌门,凡纳对虾肠道中主要为变形菌门和厚壁菌门(Firmicutes)。微生物来源(Source Tracker)分析表明,沉积物与肠道微生物的交换数量高于水体与肠道微生物的交换数量。群落构建机制分析结果显示,确定性过程主导水体微生物群落的构建,水体酸碱度和化学需氧量(COD)是最主要的环境因子;沉积物和肠道中的微生物群落由确定性过程与随机过程共同决定。结果表明,凡纳对虾肠道微生物的组成和功能受到环境微生物和环境因子等多种因素影响。
