Optical coherence tomography angiography(OCTA)is a powerful tool for non-invasive,label-free,three-dimensional vi-sualization of blood vessels down to the capillary level in vivo.However,its widespread usage is hinder...Optical coherence tomography angiography(OCTA)is a powerful tool for non-invasive,label-free,three-dimensional vi-sualization of blood vessels down to the capillary level in vivo.However,its widespread usage is hindered by the trade-off between transverse sampling rate and signal-to-noise ratio(SNR).This trade-off results in either a limited field of view(FOV)to maintain sampling density or loss of capillary details to fulfil FOV requirement.It also restricts microvascular quantifications,including flow velocimetry,which typically demand higher transverse sampling rate and SNR compared with standard qualitative OCTA.We introduce spectrally extended line field OCTA(SELF-OCTA),a cost-effective imag-ing modality that improves transverse sampling rate and SNR through spectrally encoded parallel sampling and in-creased signal acquired over longer periods,respectively.In the human skin and retina in vivo,we demonstrate its ad-vantages in achieving significantly extended FOV without sacrificing microvascular resolution,high sensitivity to slower flow without compromising FOV,and flow velocity quantification with the highest dynamic range,emphasizing that these features can be achieved with readily available and standard OCTA hardware settings.SELF-OCTA has the potential to make wide-field,high-resolution,quantitative angiographic imaging accessible to a wider population,thereby facilitating the early detection and follow-up of vascular-related diseases.展开更多
Deconvolution is a commonly employed technique for enhancing image quality in optical imaging methods.Unfortu-nately,its application in optical coherence tomography(OCT)is often hindered by sensitivity to noise,which ...Deconvolution is a commonly employed technique for enhancing image quality in optical imaging methods.Unfortu-nately,its application in optical coherence tomography(OCT)is often hindered by sensitivity to noise,which leads to ad-ditive ringing artifacts.These artifacts considerably degrade the quality of deconvolved images,thereby limiting its effect-iveness in OCT imaging.In this study,we propose a framework that integrates numerical random phase masks into the deconvolution process,effectively eliminating these artifacts and enhancing image clarity.The optimized joint operation of an iterative Richardson-Lucy deconvolution and numerical synthesis of random phase masks(RPM),termed as De-conv-RPM,enables a 2.5-fold reduction in full width at half-maximum(FWHM).We demonstrate that the Deconv-RPM method significantly enhances image clarity,allowing for the discernment of previously unresolved cellular-level details in nonkeratinized epithelial cells ex vivo and moving blood cells in vivo.展开更多
Drought and heat stresses cause yield losses in alfalfa,a forage crop cultivated worldwide.Improving its drought and heat tolerance is desirable for maintaining alfalfa productivity in hot,arid regions.Cuticular wax f...Drought and heat stresses cause yield losses in alfalfa,a forage crop cultivated worldwide.Improving its drought and heat tolerance is desirable for maintaining alfalfa productivity in hot,arid regions.Cuticular wax forms a protective barrier on aerial surfaces of land plants against environmental stresses.ABCG11encodes an ATP binding cassette(ABC) transporter that functions in the cuticular wax transport pathway.In this study,Zx ABCG11 from the xerophyte Zygophyllum xanthoxylum was introduced into alfalfa by Agrobacterium tumefaciens-mediated transformation.Compared to the wild type(WT),transgenic alfalfa displayed faster growth,higher wax crystal density,and thicker cuticle on leaves under normal condition.Under either drought or heat treatment in greenhouse conditions,the plant height and shoot biomass of transgenic lines were significantly higher than those of the WT.Transgenic alfalfa showed excellent growth and 50% greater hay yield than WT under field conditions in a hot,arid region.Overexpression of Zx ABCG11 up-regulated wax-related genes and resulted in more cuticular wax deposition,which contributed to reduction of cuticle permeability and thus increased water retention and photosynthesis capacity of transgenic alfalfa.Thus,overexpression of Zx ABCG11 can simultaneously improve biomass yield,drought and heat tolerance in alfalfa by increasing cuticular wax deposition.Our study provides a promising avenue for developing novel forage cultivars suitable for planting in hot,arid,marginal lands.展开更多
At present,the incidence rate of arteriosclerosis obliterans(LEASO)of the lower extremities is significantly increased by aging and lifestyle changes.It is of great importance to predict the LEASO effectively and accu...At present,the incidence rate of arteriosclerosis obliterans(LEASO)of the lower extremities is significantly increased by aging and lifestyle changes.It is of great importance to predict the LEASO effectively and accurately by analyzing the imaging data of the lower extremities⑴.At this stage,China has entered the era of big data and artificial intelligence.Medical institutions at all levels can produce a large number of lower limb vascular image data every day.Using big data deep learning technology to intelligently analyze a large number of image data,and then carry out auxiliary diagnosis,so as to improve the diagnosis and treatment effect of LEASO is the focus of clinical research.展开更多
Noninvasive tomographic imaging of cellular processes in vivo may provide valuable cytological and histological information for disease diagnosis.However,such strategies are usually hampered by optical aberrations cau...Noninvasive tomographic imaging of cellular processes in vivo may provide valuable cytological and histological information for disease diagnosis.However,such strategies are usually hampered by optical aberrations caused by the imaging system and tissue turbidity.State-of-the-art aberration correction methods require that the light signal be phase stable over the full-field data acquisition period,which is difficult to maintain during dynamic cellular processes in vivo.Here we show that any optical aberrations in the path length difference(OPD)domain can be corrected without the phase stability requirement based on maximum intensity assumption.Specifically,we demonstrate a novel optical tomographic technique,termed amplitude division aperture synthesis optical coherence tomography(ADAS-OCT),which corrects aberrations induced by turbid tissues by physical aperture synthesis and simultaneously data acquisition from sub-apertures.Even with just two subapertures,ADAS-OCT enabled in vivo visualization of red blood cells in human labial mucosa.We further demonstrated that adding sub-apertures could significantly scale up the aberration correction capability.This technology has the potential to impact a number of clinical areas where noninvasive examinations are preferred,such as blood count and cancers detection.展开更多
基金support from the Ministry of Education Singapore under its Academic Research Funding Tier 2 grant(MOE-T2EP30120-0001)Academic Research Funding Tier 1 grant(RG35/22)+1 种基金Singapore National Medical Research Council CS-NIG grant(MOH-CNIG24jan-0004)Guangzhou National Laboratory grant(GZNL2025C03014).
文摘Optical coherence tomography angiography(OCTA)is a powerful tool for non-invasive,label-free,three-dimensional vi-sualization of blood vessels down to the capillary level in vivo.However,its widespread usage is hindered by the trade-off between transverse sampling rate and signal-to-noise ratio(SNR).This trade-off results in either a limited field of view(FOV)to maintain sampling density or loss of capillary details to fulfil FOV requirement.It also restricts microvascular quantifications,including flow velocimetry,which typically demand higher transverse sampling rate and SNR compared with standard qualitative OCTA.We introduce spectrally extended line field OCTA(SELF-OCTA),a cost-effective imag-ing modality that improves transverse sampling rate and SNR through spectrally encoded parallel sampling and in-creased signal acquired over longer periods,respectively.In the human skin and retina in vivo,we demonstrate its ad-vantages in achieving significantly extended FOV without sacrificing microvascular resolution,high sensitivity to slower flow without compromising FOV,and flow velocity quantification with the highest dynamic range,emphasizing that these features can be achieved with readily available and standard OCTA hardware settings.SELF-OCTA has the potential to make wide-field,high-resolution,quantitative angiographic imaging accessible to a wider population,thereby facilitating the early detection and follow-up of vascular-related diseases.
基金supported by the Guangdong Natural Science Fund General Program (2023A1515011289)Singapore Ministry of Health's National Medical Research Council under its Open Fund Individual Research Grant (MOH-OFIRG19may-0009)+2 种基金Ministry of Education Singapore under its Academic Research Fund Tier 1 (RG35/22)Academic Research Funding Tier 2 (MOE-T2EP30120-0001)China-Singapore International Joint Research Institute (203-A022001).
文摘Deconvolution is a commonly employed technique for enhancing image quality in optical imaging methods.Unfortu-nately,its application in optical coherence tomography(OCT)is often hindered by sensitivity to noise,which leads to ad-ditive ringing artifacts.These artifacts considerably degrade the quality of deconvolved images,thereby limiting its effect-iveness in OCT imaging.In this study,we propose a framework that integrates numerical random phase masks into the deconvolution process,effectively eliminating these artifacts and enhancing image clarity.The optimized joint operation of an iterative Richardson-Lucy deconvolution and numerical synthesis of random phase masks(RPM),termed as De-conv-RPM,enables a 2.5-fold reduction in full width at half-maximum(FWHM).We demonstrate that the Deconv-RPM method significantly enhances image clarity,allowing for the discernment of previously unresolved cellular-level details in nonkeratinized epithelial cells ex vivo and moving blood cells in vivo.
基金supported by the National Key Research and Development Program of China (2022YFF1003200)the National Natural Science Foundation of China (31730093)。
文摘Drought and heat stresses cause yield losses in alfalfa,a forage crop cultivated worldwide.Improving its drought and heat tolerance is desirable for maintaining alfalfa productivity in hot,arid regions.Cuticular wax forms a protective barrier on aerial surfaces of land plants against environmental stresses.ABCG11encodes an ATP binding cassette(ABC) transporter that functions in the cuticular wax transport pathway.In this study,Zx ABCG11 from the xerophyte Zygophyllum xanthoxylum was introduced into alfalfa by Agrobacterium tumefaciens-mediated transformation.Compared to the wild type(WT),transgenic alfalfa displayed faster growth,higher wax crystal density,and thicker cuticle on leaves under normal condition.Under either drought or heat treatment in greenhouse conditions,the plant height and shoot biomass of transgenic lines were significantly higher than those of the WT.Transgenic alfalfa showed excellent growth and 50% greater hay yield than WT under field conditions in a hot,arid region.Overexpression of Zx ABCG11 up-regulated wax-related genes and resulted in more cuticular wax deposition,which contributed to reduction of cuticle permeability and thus increased water retention and photosynthesis capacity of transgenic alfalfa.Thus,overexpression of Zx ABCG11 can simultaneously improve biomass yield,drought and heat tolerance in alfalfa by increasing cuticular wax deposition.Our study provides a promising avenue for developing novel forage cultivars suitable for planting in hot,arid,marginal lands.
基金Scientific research project of Sichuan Provincial Health Commission"auxiliary diagnosis of lower extremity arteriosclerosis obliterans based on deep learning of big data,"No.:18PJ488.
文摘At present,the incidence rate of arteriosclerosis obliterans(LEASO)of the lower extremities is significantly increased by aging and lifestyle changes.It is of great importance to predict the LEASO effectively and accurately by analyzing the imaging data of the lower extremities⑴.At this stage,China has entered the era of big data and artificial intelligence.Medical institutions at all levels can produce a large number of lower limb vascular image data every day.Using big data deep learning technology to intelligently analyze a large number of image data,and then carry out auxiliary diagnosis,so as to improve the diagnosis and treatment effect of LEASO is the focus of clinical research.
基金supported by National Research Foundation Singapore under its Competitive Research Program(NRF-CRP13–2014-05)Ministry of Education Singapore under its Academic Research Fund Tier 1(2018-T1–001-144)Agency for Science,Technology and Research(A*STAR)under its Industrial Alignment Fund(Pre-positioning)(H17/01/a0/008).
文摘Noninvasive tomographic imaging of cellular processes in vivo may provide valuable cytological and histological information for disease diagnosis.However,such strategies are usually hampered by optical aberrations caused by the imaging system and tissue turbidity.State-of-the-art aberration correction methods require that the light signal be phase stable over the full-field data acquisition period,which is difficult to maintain during dynamic cellular processes in vivo.Here we show that any optical aberrations in the path length difference(OPD)domain can be corrected without the phase stability requirement based on maximum intensity assumption.Specifically,we demonstrate a novel optical tomographic technique,termed amplitude division aperture synthesis optical coherence tomography(ADAS-OCT),which corrects aberrations induced by turbid tissues by physical aperture synthesis and simultaneously data acquisition from sub-apertures.Even with just two subapertures,ADAS-OCT enabled in vivo visualization of red blood cells in human labial mucosa.We further demonstrated that adding sub-apertures could significantly scale up the aberration correction capability.This technology has the potential to impact a number of clinical areas where noninvasive examinations are preferred,such as blood count and cancers detection.
