Recent understanding of the role of epigenetic regulation in health and disease has necessitated the development of newer and efficient methods to map the methylation pattern of target gene. In this article we report ...Recent understanding of the role of epigenetic regulation in health and disease has necessitated the development of newer and efficient methods to map the methylation pattern of target gene. In this article we report construction of a stage-scanning laser confocal microscope (SLCM) and associated protocol that determines the methylation status of target gene. We have adapted restricted Sanger’s sequencing where fluorescine labeled primers and dideoxy guanine fraction alone are used for target amplification and termination at cytosine positions. Amplified ssDNA bands are separated in 6% denaturing PAGE and scanned using SLCM to sequence the positions of methylated cytosines. We demonstrate that our me- thodology can detect < 100 femtomoles of DNA, and resolve the position of cytosine within ± 2 nucleotide. In a calibration run using a designer DNA of 99 bases, our methodology had resolved all the 11 cytosine positions of the DNA. We have further demonstrated the utility of apparatus by mapping methylation status in the Exon-1 region of a gene, E-Cadherin, in the plasma DNA sample of a healthy subject. We believe our approach constitute a low cost alternative to conventional DNA sequencers and can help develop methylation based DNA biomarkers for the diagnosis of disease and in therapeutics.展开更多
Phase is one of the most important parameters of electromagnetic waves. It is the phase distribution that determines the propagation, reflection, refraction, focusing, divergence, and coupling features of light, and f...Phase is one of the most important parameters of electromagnetic waves. It is the phase distribution that determines the propagation, reflection, refraction, focusing, divergence, and coupling features of light, and further affects the intensity distribution. In recent years, the designs of surface plasmon polariton （SPP） devices have mostly been based on the phase modulation and manipulation. Here we demonstrate a phase sensitive multi-parameter heterodyne scanning near-field opti- cal microscope （SNOM） with an aperture probe in the visible range, with which the near field optical phase and amplitude distributions can be simultaneously obtained. A novel architecture combining a spatial optical path and a fiber optical path is employed for stability and flexibility. Two kinds of typical nano-photonic devices are tested with the system. With the phase-sensitive SNOM, the phase and amplitude distributions of any nano-optical field and localized field generated with any SPP nano-structures and irregular phase modulation surfaces can be investigated. The phase distribution and the interference pattern will help us to gain a better understanding of how light interacts with SPP structures and how SPP waves generate, localize, convert, and propagate on an SPP surface. This will be a significant guidance on SPP nano-structure design and optimization.展开更多
Bladder urothelial carcinoma is the most common malignant tumor disease in urinary system,and its incidence rate ranks ninth in the world.In recent years,the continuous development of hyperspectral imaging technology ...Bladder urothelial carcinoma is the most common malignant tumor disease in urinary system,and its incidence rate ranks ninth in the world.In recent years,the continuous development of hyperspectral imaging technology has provided a new tool for the auxiliary diagnosis of bladder cancer.In this study,based on microscopic hyperspectral data,an automatic detection algorithm of bladder tumor cells combining color features and shape features is proposed.Support vector machine(SVM)is used to build classification models and compare the classification performance of spectral feature,spectral and shape fusion feature,and the fusion feature proposed in this paper on the same classifier.The results show that the sensitivity,specificity,and accuracy of our classification algorithm based on shape and color fusion features are 0.952,0.897,and 0.920,respectively,which are better than the classification algorithm only using spectral features.Therefore,this study can effectively extract the cell features of bladder urothelial carcinoma smear,thus achieving automatic,real-time,and noninvasive detection of bladder tumor cells,and then helping doctors improve the efficiency of pathological diagnosis of bladder urothelial cancer,and providing a reliable basis for doctors to choose treatment plans and judge the prognosis of the disease.展开更多
[Objectives]To study the microscopic characteristics and routine detection of Hedyotis hedyotidea(DC.)Merr.[Methods]The microscopic characteristics of the root,stem cross section and the whole plant powder of H.hedyot...[Objectives]To study the microscopic characteristics and routine detection of Hedyotis hedyotidea(DC.)Merr.[Methods]The microscopic characteristics of the root,stem cross section and the whole plant powder of H.hedyotidea were studied by the methods of slide-shaft section,biological staining and microscopic imaging;the routine detection items such as moisture,ash,acid-insoluble ash and extract were detected and analyzed in accordance with the requirements of Chinese Pharmacopoeia.[Results]The microscopic characteristics of the root,the stem and the whole plant powder of H.hedyotidea were obtained.The moisture content of 10 batches of H.hedyotidea samples was in the range of 4.25%-7.90%,the water-soluble extract is in the range of 15.08%-22.52%,the total ash was in the scope of 8.27%-10.45%,and the acid-insoluble ash was in 0.13%-0.95%.The proposed water content of H.hedyotidea should not exceed 10.00%,the water-soluble extract should not be less than 12.00%,the total ash content should not exceed 13.00%,and the acid-insoluble ash content should not exceed 1.20%.[Conclusions]The results of this experiment can provide a reference for the quality control and quality standard of H.hedyotidea.展开更多
Cryo-electron microscopy(cryo-EM)has become one of the mainstream techniques for determining the structures of proteins andmacromolecular complexes,with prospects for development and significance.Researchers must sele...Cryo-electron microscopy(cryo-EM)has become one of the mainstream techniques for determining the structures of proteins andmacromolecular complexes,with prospects for development and significance.Researchers must select hundreds of thousands of particles from micrographs to acquire the database for single-particle cryo-EM reconstruction.However,existing particle picking methods cannot ensure that the particles are in the center of the bounding box because the signal-to-noise ratio(SNR)of micrographs is extremely low,thereby directly affecting the efficiency and accuracy of 3D reconstruction.We propose an automated particle-picking method(CenterPicker)based on particle center point detection to automatically select a large number of high-quality particles from low signal-to-noise,low-contrast refrigerated microscopy images.The method uses a fully convolutional neural network to generate a keypoint heatmap.The heatmap value represents the probability that a micrograph pixel belongs to a particle center area.CenterPicker can process images of any size and can directly predict the center point and size of the particle.The network implements multiscale feature fusion and introduces an attention mechanism to improve the feature fusion part to obtain more accurate selection results.We have conducted a detailed evaluation of CenterPicker on a range of datasets,and results indicate that it excels in single-particle picking tasks.展开更多
As an emerging microscopic detection tool,quantum microscopes based on the principle of quantum precision measurement have attracted widespread attention in recent years.Compared with the imaging of classical light,qu...As an emerging microscopic detection tool,quantum microscopes based on the principle of quantum precision measurement have attracted widespread attention in recent years.Compared with the imaging of classical light,quantum-enhanced imaging can achieve ultra-high resolution,ultra-sensitive detection,and anti-interference imaging.Here,we introduce a quantum-enhanced scanning microscope under illumination of an entangled NOON state in polarization.For the phase imager with NOON states,we propose a simple four-basis projection method to replace the four-step phase-shifting method.We have achieved the phase imaging of micrometer-sized birefringent samples and biological cell specimens,with sensitivity close to the Heisenberg limit.The visibility of transmittance-based imaging shows a great enhancement for NOON states.Besides,we also demonstrate that the scanning imaging with NOON states enables the spatial resolution enhancement of√N compared with classical measurement.Our imaging method may provide some reference for the practical application of quantum imaging and is expected to promote the development of microscopic detection.展开更多
文摘Recent understanding of the role of epigenetic regulation in health and disease has necessitated the development of newer and efficient methods to map the methylation pattern of target gene. In this article we report construction of a stage-scanning laser confocal microscope (SLCM) and associated protocol that determines the methylation status of target gene. We have adapted restricted Sanger’s sequencing where fluorescine labeled primers and dideoxy guanine fraction alone are used for target amplification and termination at cytosine positions. Amplified ssDNA bands are separated in 6% denaturing PAGE and scanned using SLCM to sequence the positions of methylated cytosines. We demonstrate that our me- thodology can detect < 100 femtomoles of DNA, and resolve the position of cytosine within ± 2 nucleotide. In a calibration run using a designer DNA of 99 bases, our methodology had resolved all the 11 cytosine positions of the DNA. We have further demonstrated the utility of apparatus by mapping methylation status in the Exon-1 region of a gene, E-Cadherin, in the plasma DNA sample of a healthy subject. We believe our approach constitute a low cost alternative to conventional DNA sequencers and can help develop methylation based DNA biomarkers for the diagnosis of disease and in therapeutics.
基金supported by the National Natural Science Foundation of China(Grant Nos.61177089,61227014,and 60978047)
文摘Phase is one of the most important parameters of electromagnetic waves. It is the phase distribution that determines the propagation, reflection, refraction, focusing, divergence, and coupling features of light, and further affects the intensity distribution. In recent years, the designs of surface plasmon polariton （SPP） devices have mostly been based on the phase modulation and manipulation. Here we demonstrate a phase sensitive multi-parameter heterodyne scanning near-field opti- cal microscope （SNOM） with an aperture probe in the visible range, with which the near field optical phase and amplitude distributions can be simultaneously obtained. A novel architecture combining a spatial optical path and a fiber optical path is employed for stability and flexibility. Two kinds of typical nano-photonic devices are tested with the system. With the phase-sensitive SNOM, the phase and amplitude distributions of any nano-optical field and localized field generated with any SPP nano-structures and irregular phase modulation surfaces can be investigated. The phase distribution and the interference pattern will help us to gain a better understanding of how light interacts with SPP structures and how SPP waves generate, localize, convert, and propagate on an SPP surface. This will be a significant guidance on SPP nano-structure design and optimization.
基金Bethune Medical Engineering and Instrument Center Fund(E10133Y8H0)Jilin province science and technology development plan project(20210204216YY,20210204146YY).
文摘Bladder urothelial carcinoma is the most common malignant tumor disease in urinary system,and its incidence rate ranks ninth in the world.In recent years,the continuous development of hyperspectral imaging technology has provided a new tool for the auxiliary diagnosis of bladder cancer.In this study,based on microscopic hyperspectral data,an automatic detection algorithm of bladder tumor cells combining color features and shape features is proposed.Support vector machine(SVM)is used to build classification models and compare the classification performance of spectral feature,spectral and shape fusion feature,and the fusion feature proposed in this paper on the same classifier.The results show that the sensitivity,specificity,and accuracy of our classification algorithm based on shape and color fusion features are 0.952,0.897,and 0.920,respectively,which are better than the classification algorithm only using spectral features.Therefore,this study can effectively extract the cell features of bladder urothelial carcinoma smear,thus achieving automatic,real-time,and noninvasive detection of bladder tumor cells,and then helping doctors improve the efficiency of pathological diagnosis of bladder urothelial cancer,and providing a reliable basis for doctors to choose treatment plans and judge the prognosis of the disease.
基金Supported by 2019-2021 Guangxi First-class Discipline Construction Open Project of Guangxi University of Chinese Medicine(2019XK096).
文摘[Objectives]To study the microscopic characteristics and routine detection of Hedyotis hedyotidea(DC.)Merr.[Methods]The microscopic characteristics of the root,stem cross section and the whole plant powder of H.hedyotidea were studied by the methods of slide-shaft section,biological staining and microscopic imaging;the routine detection items such as moisture,ash,acid-insoluble ash and extract were detected and analyzed in accordance with the requirements of Chinese Pharmacopoeia.[Results]The microscopic characteristics of the root,the stem and the whole plant powder of H.hedyotidea were obtained.The moisture content of 10 batches of H.hedyotidea samples was in the range of 4.25%-7.90%,the water-soluble extract is in the range of 15.08%-22.52%,the total ash was in the scope of 8.27%-10.45%,and the acid-insoluble ash was in 0.13%-0.95%.The proposed water content of H.hedyotidea should not exceed 10.00%,the water-soluble extract should not be less than 12.00%,the total ash content should not exceed 13.00%,and the acid-insoluble ash content should not exceed 1.20%.[Conclusions]The results of this experiment can provide a reference for the quality control and quality standard of H.hedyotidea.
基金supported by Key Projects of the Ministry of Science and Technology of the People Republic of China(2018AAA0102301).
文摘Cryo-electron microscopy(cryo-EM)has become one of the mainstream techniques for determining the structures of proteins andmacromolecular complexes,with prospects for development and significance.Researchers must select hundreds of thousands of particles from micrographs to acquire the database for single-particle cryo-EM reconstruction.However,existing particle picking methods cannot ensure that the particles are in the center of the bounding box because the signal-to-noise ratio(SNR)of micrographs is extremely low,thereby directly affecting the efficiency and accuracy of 3D reconstruction.We propose an automated particle-picking method(CenterPicker)based on particle center point detection to automatically select a large number of high-quality particles from low signal-to-noise,low-contrast refrigerated microscopy images.The method uses a fully convolutional neural network to generate a keypoint heatmap.The heatmap value represents the probability that a micrograph pixel belongs to a particle center area.CenterPicker can process images of any size and can directly predict the center point and size of the particle.The network implements multiscale feature fusion and introduces an attention mechanism to improve the feature fusion part to obtain more accurate selection results.We have conducted a detailed evaluation of CenterPicker on a range of datasets,and results indicate that it excels in single-particle picking tasks.
基金supported by he National Natural Science Foundation of China(Grant Nos.12304359,12304398,12404382,12234009,12274215,and 12427808)the China Postdoctoral Science Foundation(Grant No.2023M731611)+4 种基金the Jiangsu Funding Program for Excellent Postdoctoral Talent(Grant No.2023ZB717)Innovation Program for Quantum Science and Technology(Grant No.2021ZD0301400)Key R&D Program of Jiangsu Province(Grant No.BE2023002)Natural Science Foundation of Jiangsu Province(Grant Nos.BK20220759 and BK20233001)Program for Innovative Talents and Entrepreneurs in Jiangsu,and Key R&D Program of Guangdong Province(Grant No.2020B0303010001).
文摘As an emerging microscopic detection tool,quantum microscopes based on the principle of quantum precision measurement have attracted widespread attention in recent years.Compared with the imaging of classical light,quantum-enhanced imaging can achieve ultra-high resolution,ultra-sensitive detection,and anti-interference imaging.Here,we introduce a quantum-enhanced scanning microscope under illumination of an entangled NOON state in polarization.For the phase imager with NOON states,we propose a simple four-basis projection method to replace the four-step phase-shifting method.We have achieved the phase imaging of micrometer-sized birefringent samples and biological cell specimens,with sensitivity close to the Heisenberg limit.The visibility of transmittance-based imaging shows a great enhancement for NOON states.Besides,we also demonstrate that the scanning imaging with NOON states enables the spatial resolution enhancement of√N compared with classical measurement.Our imaging method may provide some reference for the practical application of quantum imaging and is expected to promote the development of microscopic detection.
