Background:This study aimed to compare sublingual microcirculatory parameters between anesthetized pigs and conscious adult humans using sidestream darkfield videomicroscopy.The overarching aim of the work was to vali...Background:This study aimed to compare sublingual microcirculatory parameters between anesthetized pigs and conscious adult humans using sidestream darkfield videomicroscopy.The overarching aim of the work was to validate the pig as an experimental model of changes in microcirculatory function following traumatic haemorrhagic shock and resuscitation.Methods:Fourteen large white pigs and 14 humans were recruited for the study.Sublingual sidestream darkfield videomicroscopy clips were captured in anesthetized pigs and conscious humans.Clips underwent manual analysis in Automated Vascular Analysis 3.2 software.The total vessel density(TVD),perfused vessel density(PVD),proportion of perfused vessels(PPVs)and microvascular flow index(MFI)were quantified.An independent samples t test was used for between species comparison of microcirculatory parameters.Results and Conclusions:Conscious humans had a significantly lower TVD,PVD and MFI than anesthetized pigs.No significant difference in PPVs was observed between the species.Perfusion of the microcirculation is a critical determinant of tissue metabolic function and viability.Whilst it may not be surprising that some inter species differences in the sublingual microcirculatory anatomy were identified between pig and human subjects,it is interesting to report the insignificant difference in PPVs.This direct microcirculatory measure represents a relative change which should hold translatable value across species.We therefore conclude the pig is a suitable model for microcirculatory research and may be a suitable species to investigate changes in microcirculatory perfusion following perturbations in cardiovascular homeostasis,for example during traumatic haemorrhagic shock and resuscitation.展开更多
Transport of intensity equation(TIE)is a well-established non-interferometric phase retrieval approach that enables quantitative phase imaging(QPI)by simply measuring intensity images at multiple axially displaced pla...Transport of intensity equation(TIE)is a well-established non-interferometric phase retrieval approach that enables quantitative phase imaging(QPI)by simply measuring intensity images at multiple axially displaced planes.The advantage of a TIE-based QPI system is its compatibility with partially coherent illumination,which provides speckle-free imaging with resolution beyond the coherent diffraction limit.However,TIE is generally implemented with a brightfield(BF)configuration,and the maximum achievable imaging resolution is still limited to the incoherent diffraction limit(twice the coherent diffraction limit).It is desirable that TIE-related approaches can surpass this limit and achieve high-throughput[high-resolution and wide field of view(FOV)]QPI.We propose a hybrid BF and darkfield transport of intensity(HBDTI)approach for highthroughput quantitative phase microscopy.Two through-focus intensity stacks corresponding to BF and darkfield illuminations are acquired through a low-numerical-aperture(NA)objective lens.The high-resolution and large-FOV complex amplitude(both quantitative absorption and phase distributions)can then be synthesized based on an iterative phase retrieval algorithm taking the coherence model decomposition into account.The effectiveness of the proposed method is experimentally verified by the retrieval of the USAF resolution target and different types of biological cells.The experimental results demonstrate that the half-width imaging resolution can be improved from 1230 nm to 488 nm with 2.5×expansion across a 4×FOV of 7.19 mm2,corresponding to a 6.25×increase in space-bandwidth product from∼5 to∼30.2 megapixels.In contrast to conventional TIE-based QPI methods where only BF illumination is used,the synthetic aperture process of HBDTI further incorporates darkfield illuminations to expand the accessible object frequency,thereby significantly extending the maximum available resolution from 2NA to∼5NA with a∼5×promotion of the coherent diffraction limit.Given its capability for high-throughput QPI,the proposed HBDTI approach is expected to be adopted in biomedical fields,such as personalized genomics and cancer diagnostics.展开更多
The plasma membrane possesses a complicated structure, on which the protein clusters are randomly but orderly distributed to maintain the regular morphology and function of cells. Investigating the detailed dynamic be...The plasma membrane possesses a complicated structure, on which the protein clusters are randomly but orderly distributed to maintain the regular morphology and function of cells. Investigating the detailed dynamic behaviors of nanoparticles(NPs) on cytomembrane is of great importance to understand cellular mechanisms and advance the bio-nano technologies for drug delivery, photothermal therapy, immunotherapy, etc. In this work, to study the dynamic heterogeneous interactions between NPs and cell membrane with high resolution, we established a simple method to efficiently track the translational and rotational diffusion of individual gold nanorods(AuNRs) on cell membranes. This method is based on that an anisotropic AuNR appears as a colored spot under a darkfield microscope(DFM) equipped with a color camera. While obtaining its lateral position, the polar angle of the AuNR can be calculated simultaneously from intensity difference between the R and G channels. Careful analysis shows that the lateral motion of single AuNRs do not follow normal Brownian diffusion, which could be attributed to their hop diffusion in the dynamically varying picket-fence structure of the live cell membrane. Furthermore, 4 different rotationtranslation patterns of the AuNR are observed due to spatiotemporal heterogeneity of the cytomembrane. This simple but robust method for simultaneously obtaining the location and orientation of anisotropic plasmonic nanoparticles could be further applied to the analysis of complicated biological and biomedical processes.展开更多
基金UQ Midwinter Group funds.RL received PhD candidature funding from the Australian Government Research Training Program.
文摘Background:This study aimed to compare sublingual microcirculatory parameters between anesthetized pigs and conscious adult humans using sidestream darkfield videomicroscopy.The overarching aim of the work was to validate the pig as an experimental model of changes in microcirculatory function following traumatic haemorrhagic shock and resuscitation.Methods:Fourteen large white pigs and 14 humans were recruited for the study.Sublingual sidestream darkfield videomicroscopy clips were captured in anesthetized pigs and conscious humans.Clips underwent manual analysis in Automated Vascular Analysis 3.2 software.The total vessel density(TVD),perfused vessel density(PVD),proportion of perfused vessels(PPVs)and microvascular flow index(MFI)were quantified.An independent samples t test was used for between species comparison of microcirculatory parameters.Results and Conclusions:Conscious humans had a significantly lower TVD,PVD and MFI than anesthetized pigs.No significant difference in PPVs was observed between the species.Perfusion of the microcirculation is a critical determinant of tissue metabolic function and viability.Whilst it may not be surprising that some inter species differences in the sublingual microcirculatory anatomy were identified between pig and human subjects,it is interesting to report the insignificant difference in PPVs.This direct microcirculatory measure represents a relative change which should hold translatable value across species.We therefore conclude the pig is a suitable model for microcirculatory research and may be a suitable species to investigate changes in microcirculatory perfusion following perturbations in cardiovascular homeostasis,for example during traumatic haemorrhagic shock and resuscitation.
基金the National Natural Science Foundation of China(61905115,62105151,62175109,and U21B2033)Leading Technology of Jiangsu Basic Research Plan(BK20192003)+2 种基金Youth Foundation of Jiangsu Province(BK20190445,BK20210338)Fundamental Research Funds for the Central Universities(30920032101)Open Research Fund of Jiangsu Key Laboratory of Spectral Imaging and Intelligent Sense(JSGP202105).
文摘Transport of intensity equation(TIE)is a well-established non-interferometric phase retrieval approach that enables quantitative phase imaging(QPI)by simply measuring intensity images at multiple axially displaced planes.The advantage of a TIE-based QPI system is its compatibility with partially coherent illumination,which provides speckle-free imaging with resolution beyond the coherent diffraction limit.However,TIE is generally implemented with a brightfield(BF)configuration,and the maximum achievable imaging resolution is still limited to the incoherent diffraction limit(twice the coherent diffraction limit).It is desirable that TIE-related approaches can surpass this limit and achieve high-throughput[high-resolution and wide field of view(FOV)]QPI.We propose a hybrid BF and darkfield transport of intensity(HBDTI)approach for highthroughput quantitative phase microscopy.Two through-focus intensity stacks corresponding to BF and darkfield illuminations are acquired through a low-numerical-aperture(NA)objective lens.The high-resolution and large-FOV complex amplitude(both quantitative absorption and phase distributions)can then be synthesized based on an iterative phase retrieval algorithm taking the coherence model decomposition into account.The effectiveness of the proposed method is experimentally verified by the retrieval of the USAF resolution target and different types of biological cells.The experimental results demonstrate that the half-width imaging resolution can be improved from 1230 nm to 488 nm with 2.5×expansion across a 4×FOV of 7.19 mm2,corresponding to a 6.25×increase in space-bandwidth product from∼5 to∼30.2 megapixels.In contrast to conventional TIE-based QPI methods where only BF illumination is used,the synthetic aperture process of HBDTI further incorporates darkfield illuminations to expand the accessible object frequency,thereby significantly extending the maximum available resolution from 2NA to∼5NA with a∼5×promotion of the coherent diffraction limit.Given its capability for high-throughput QPI,the proposed HBDTI approach is expected to be adopted in biomedical fields,such as personalized genomics and cancer diagnostics.
基金supported by the National Natural Science Foundation of China (21127009, 21425519, 21221003, 21475071, 21605045)the Tsinghua University Startup Fund, the Taishan Scholar Program of Shandong Province (ts201511027)the Natural Science Foundation of Shandong (2018GGX102030)
文摘The plasma membrane possesses a complicated structure, on which the protein clusters are randomly but orderly distributed to maintain the regular morphology and function of cells. Investigating the detailed dynamic behaviors of nanoparticles(NPs) on cytomembrane is of great importance to understand cellular mechanisms and advance the bio-nano technologies for drug delivery, photothermal therapy, immunotherapy, etc. In this work, to study the dynamic heterogeneous interactions between NPs and cell membrane with high resolution, we established a simple method to efficiently track the translational and rotational diffusion of individual gold nanorods(AuNRs) on cell membranes. This method is based on that an anisotropic AuNR appears as a colored spot under a darkfield microscope(DFM) equipped with a color camera. While obtaining its lateral position, the polar angle of the AuNR can be calculated simultaneously from intensity difference between the R and G channels. Careful analysis shows that the lateral motion of single AuNRs do not follow normal Brownian diffusion, which could be attributed to their hop diffusion in the dynamically varying picket-fence structure of the live cell membrane. Furthermore, 4 different rotationtranslation patterns of the AuNR are observed due to spatiotemporal heterogeneity of the cytomembrane. This simple but robust method for simultaneously obtaining the location and orientation of anisotropic plasmonic nanoparticles could be further applied to the analysis of complicated biological and biomedical processes.
