Histopathology relies upon the staining and sectioning of biological tissues,which can be laborious and may cause artifacts and distort tissues.We develop label-free volumetric imaging of thick-tissue slides,exploitin...Histopathology relies upon the staining and sectioning of biological tissues,which can be laborious and may cause artifacts and distort tissues.We develop label-free volumetric imaging of thick-tissue slides,exploiting refractive index distributions as intrinsic imaging contrast.The present method systematically exploits label-free quantitative phase imaging techniques,volumetric reconstruction of intrinsic refractive index distributions in tissues,and numerical algorithms for the seamless stitching of multiple three-dimensional tomograms and for reducing scattering-induced image distortion.We demonstrated label-free volumetric imaging of thick tissues with the field of view of 2 mm×1.75 mm×0.2 mm with a spatial resolution of 170 nm×170 nm×1400 nm.The number of optical modes,calculated as the reconstructed volume divided by the size of the point spread function,was∼20 giga voxels.We have also demonstrated that different tumor types and a variety of precursor lesions and pathologies can be visualized with the present method.展开更多
Optical flow method is one of the most important methods of analyzing motion images. Optical flow field is used to analyze characteristics of motion objects. According to motion features of micro-electronic mechani-ca...Optical flow method is one of the most important methods of analyzing motion images. Optical flow field is used to analyze characteristics of motion objects. According to motion features of micro-electronic mechani-cal system (MEMS) micro-structure, the optical algorithm based on label field and neighborhood optimization is presented to analyze the in-plane micro-motion of micro-structure. Firstly, high speed motion states for each fre-quency segment of micro-structure in cyclic motion are frozen based on stroboscopic principle. Thus a series of dynamic images of micro-structure are obtained. Secondly, the presented optical algorithm is used to analyze the image sequences, and can obtain reliable and precise optical field and reduce computing time. As micro-resonator of testing object, the phase-amplitude curve of micro-structure is derived. Experimental results indicate that the meas-urement precision of the presented algorithm is high, and measurement repeatability reaches 40 nm under the same experiment condition.展开更多
Silicon nanowire （SiNW）, as one-dimensional semiconducting nanomaterial, has been incorporated into the filed-effect transistor （FET） devices to increase the efficacy and signal-to-noise in DNA sensing application...Silicon nanowire （SiNW）, as one-dimensional semiconducting nanomaterial, has been incorporated into the filed-effect transistor （FET） devices to increase the efficacy and signal-to-noise in DNA sensing applications. Due to the advantages of high sensitivity, excellent selectivity, label-free detection, direct electrical readout, and minia- turization, SiNW FET-based DNA sensors have been regarded as an important tool in applications of molecular di- agnostics, DNA sequencing, gene expressions, and drug discovery. Here, we review the recent progress in SiNW- FET sensors for label-free electrical DNA detection. We first introduce the working principle of SiNW-FET DNA sensors, SiNW fabrication technologies, bio-functionalization on nanowire surface, and enhancement of device sen- sitivity. Then we sum up the applications of SiNW sensors in detection of DNA hybridization, infectious viruses, microRNA, genetic change （DNA mutation, DNA methylation, and DNA repair）, and protein-DNA interactions. We address several crucial points of sensing performance including sensitivity, selectivity, and limit of detection. Finally, the perspectives, challenges, and some solutions of the field are also discussed.展开更多
We employ nondestructive evaluation involving AC field measurement in detecting and identifying metal barcode labels,providing a reference for design.Using the magnetic scalar potential boundary condition at notches i...We employ nondestructive evaluation involving AC field measurement in detecting and identifying metal barcode labels,providing a reference for design.Using the magnetic scalar potential boundary condition at notches in thin-skin field theory and 2D Fourier transform,we introduce an analytical model for the magnetic scalar potential induced by the interaction of a high-frequency inducer with a metal barcode label containing multiple narrow saw-cut notches,and then calculate the magnetic field in the free space above the metal barcode label.With the simulations of the magnetic field,qualitative analysis is given for the effects on detecting and identifying metal barcode labels,which are caused by metal material,notch characteristics,exciting inducer properties,and other factors that can be used in metal barcode label design as reference.Simulation results are in good accordance with experiment results.展开更多
基金H.H.,R.H.H.,S.-M.H.,and Y.P.conceived the initial idea.H.H.developed the optical system and analysis methods.H.H.and Y.W.K.performed the experiments and analyzed the data.M.L.and S.S.provided the analysis methods and analyzed the data.All authors wrote and revised the manuscript.This work was supported by KAIST,Up Program,BK21+program,Tomocube,and National Research Foundation of Korea(2017M3C1A3013923,2015R1A3A2066550,and 2018K000396).Professor Park and Mr.Moosung Lee have financial interests in Tomocube Inc.,a company that commercializes optical diffraction tomography and quantitative phase imaging instruments and is one of the sponsors of the work.
文摘Histopathology relies upon the staining and sectioning of biological tissues,which can be laborious and may cause artifacts and distort tissues.We develop label-free volumetric imaging of thick-tissue slides,exploiting refractive index distributions as intrinsic imaging contrast.The present method systematically exploits label-free quantitative phase imaging techniques,volumetric reconstruction of intrinsic refractive index distributions in tissues,and numerical algorithms for the seamless stitching of multiple three-dimensional tomograms and for reducing scattering-induced image distortion.We demonstrated label-free volumetric imaging of thick tissues with the field of view of 2 mm×1.75 mm×0.2 mm with a spatial resolution of 170 nm×170 nm×1400 nm.The number of optical modes,calculated as the reconstructed volume divided by the size of the point spread function,was∼20 giga voxels.We have also demonstrated that different tumor types and a variety of precursor lesions and pathologies can be visualized with the present method.
基金Supported by Youth Natural Science Foundation of Beijing University of Chemical Technology (No.QN0734).
文摘Optical flow method is one of the most important methods of analyzing motion images. Optical flow field is used to analyze characteristics of motion objects. According to motion features of micro-electronic mechani-cal system (MEMS) micro-structure, the optical algorithm based on label field and neighborhood optimization is presented to analyze the in-plane micro-motion of micro-structure. Firstly, high speed motion states for each fre-quency segment of micro-structure in cyclic motion are frozen based on stroboscopic principle. Thus a series of dynamic images of micro-structure are obtained. Secondly, the presented optical algorithm is used to analyze the image sequences, and can obtain reliable and precise optical field and reduce computing time. As micro-resonator of testing object, the phase-amplitude curve of micro-structure is derived. Experimental results indicate that the meas-urement precision of the presented algorithm is high, and measurement repeatability reaches 40 nm under the same experiment condition.
文摘Silicon nanowire （SiNW）, as one-dimensional semiconducting nanomaterial, has been incorporated into the filed-effect transistor （FET） devices to increase the efficacy and signal-to-noise in DNA sensing applications. Due to the advantages of high sensitivity, excellent selectivity, label-free detection, direct electrical readout, and minia- turization, SiNW FET-based DNA sensors have been regarded as an important tool in applications of molecular di- agnostics, DNA sequencing, gene expressions, and drug discovery. Here, we review the recent progress in SiNW- FET sensors for label-free electrical DNA detection. We first introduce the working principle of SiNW-FET DNA sensors, SiNW fabrication technologies, bio-functionalization on nanowire surface, and enhancement of device sen- sitivity. Then we sum up the applications of SiNW sensors in detection of DNA hybridization, infectious viruses, microRNA, genetic change （DNA mutation, DNA methylation, and DNA repair）, and protein-DNA interactions. We address several crucial points of sensing performance including sensitivity, selectivity, and limit of detection. Finally, the perspectives, challenges, and some solutions of the field are also discussed.
基金supported by the National Natural Science Foundation of China(No.61271247)
文摘We employ nondestructive evaluation involving AC field measurement in detecting and identifying metal barcode labels,providing a reference for design.Using the magnetic scalar potential boundary condition at notches in thin-skin field theory and 2D Fourier transform,we introduce an analytical model for the magnetic scalar potential induced by the interaction of a high-frequency inducer with a metal barcode label containing multiple narrow saw-cut notches,and then calculate the magnetic field in the free space above the metal barcode label.With the simulations of the magnetic field,qualitative analysis is given for the effects on detecting and identifying metal barcode labels,which are caused by metal material,notch characteristics,exciting inducer properties,and other factors that can be used in metal barcode label design as reference.Simulation results are in good accordance with experiment results.
