The mechanical properties of biological soft tissues are inextricably linked to the field of health care,and their mechanical properties can be important indicators for diagnosing and detecting diseases;they can also ...The mechanical properties of biological soft tissues are inextricably linked to the field of health care,and their mechanical properties can be important indicators for diagnosing and detecting diseases;they can also be used to analyze the causes of organ diseases from a pathological point of view and thus guide the deployment of medical solutions.As an effective method to characterize the mechanical properties of materials,mechanical loading experiments have been successfully applied to the mechanical properties of materials,including tension,compression,pure shear,and so on.Under quasi-static loading,when the material is a biological soft tissue material between a solid and an ideal fluid,its viscoelastic properties strongly respond to the force stimulus,and the stress-strain-time in the elastic phase will have obvious disturbance characteristics.Therefore,the existing statistical methods are often difficult to quantitatively describe the mechanical properties of materials.Therefore,this study proposes an Interval Capture Point based on the principle of integration.The experimental data based on this method can characterize its nonlinear mechanical properties well,especially when the loading speed is extremely low and the soft materials show strong disturbance characteristics.The proposed method can still accurately characterize the hyperelastic and viscoelastic properties of the mechanical properties of biological soft tissues under quasi-static loading.展开更多
Due to the limited capacity of corneal endothelial cells(CECs)division,corneal endothelial diseases have become a great challenge.The cornea is subjected to various mechanical stimuli in vivo,which may have a positive...Due to the limited capacity of corneal endothelial cells(CECs)division,corneal endothelial diseases have become a great challenge.The cornea is subjected to various mechanical stimuli in vivo,which may have a positive or negative influence.Thus,it is significant to gain an insight into the mechanism of mechanobiology of CECs for seeking more possible treatment.The purpose of this study was to determine the impacts of mechanical stretch and substrate stiffness on the morphology and fundamental cell behavior of CECs.Rabbit corneal endothelial cells(RCECs)were subjected to a 5%mechanical stretch or cultured on substrates of different stiffness.The impacts of mechanical stimulus on cell area,aspect ratio,circularity,cell density,nuclear shape,cytoskeleton,and cell viability were investigated.The expressions of the corneal endothelium-related markers ZO-1 and Na^(+)/K^(+) ATPase were also evaluated by confocal immunofluorescence microscopy in the stiffness group.Our results suggested that mechanical stretch promoted the rearrangement of the cytoskeleton while decreasing the cell circularity,nuclear area,and cell density as well as cell viability.RCECs cultured on 10 kPa substrates,which was close to the physiological stiffness of rabbit Descemet's membrane(DM),showed better cell morphology,more stable actin cytoskeleton assembly,and more robust expression of the functional marker compared with other softer or stiffer substrates.In summary,mechanical stretch and substrate stiffness have profound influences on the morphology and function of CECs,which may have implications for the understanding and possible treatment of corneal endothelial diseases.展开更多
Some researches to facilitate wound healing by using electrical stimulation are based on electric current stimulation,which may cause secondary damage and the imbalance of the microenvironment in vivo.In this study,al...Some researches to facilitate wound healing by using electrical stimulation are based on electric current stimulation,which may cause secondary damage and the imbalance of the microenvironment in vivo.In this study,alternating capacitive electric field(ACEF)was applied via a self-designed system so as to avoid direct contact with cells and to maintain stable microenvironment for cell growth.The influences of 58 mV/mm ACEFs with various frequencies of 10,60 and 110 Hz on epidermal cells,fibroblasts and macrophages which involve in wound healing were comprehensively explored.The results suggested that ACEFs of 10,60 and 110 Hz all significantly promoted the proliferation of human dermal fibroblasts(HDFs)and human epidermal keratinocyte cell line(HaCaT)cells,and 60 Hz ACEF furtherly accelerated the migration of these two kinds of cells.Moreover,ACEFs of all different studied frequencies facilitated M2-type polarization of macrophages,and YAP/TAZ expression of macrophages were enhanced under the stimulations of 10 and 60 Hz ACEFs.The enhancements in cell activity,migration rate and M2-type polarizability indicated that 58 mV/mm ACEFs especially at 60 Hz possessing potentially affirmative applications for wound healing without the risks of secondary damage and microenvironment imbalance.展开更多
Millions of people suffer from tissue diseases and organ dysfunction,such as bone or nerve defects,spinal cord injuries and arrhythmia,which often leads to morbidity and disability.Electrical stimulation as a promisin...Millions of people suffer from tissue diseases and organ dysfunction,such as bone or nerve defects,spinal cord injuries and arrhythmia,which often leads to morbidity and disability.Electrical stimulation as a promising nonpharmacological technique has been proven to be effective in promoting tissue regeneration and functional restoration.Nevertheless,existing clinical electrical therapies are often limited to intraoperative window or percutaneous stimulation that suffer from insufficient time frame and potential infection risks.To overcome these challenges,innovative electrical stimulation implants with miniaturized,self-powered,flexible or biodegradable features have been proposed.This review summarizes recent advances of novel materials strategies and device schemes for tissue regeneration and/or functional restoration of bones,nerves,gastrointestinal tracts,cardiac systems,etc.Insights on future directions of electrical stimulation devices are given at the end.展开更多
deep learning(DL)has achieved state-of-the-art performance in many digital pathology analysis tasks.Traditional methods usually require hand-crafted domain-specific features,and DL methods can learn representations wi...deep learning(DL)has achieved state-of-the-art performance in many digital pathology analysis tasks.Traditional methods usually require hand-crafted domain-specific features,and DL methods can learn representations without manually designed features.In terms of feature extraction,DL approaches are less labor intensive compared with conventional machine learning methods.In this paper,we comprehensively summarize recent DL-based image analysis studies in histopathology,including different tasks(e.g.,classification,semantic segmentation,detection,and instance segmentation)and various applications(e.g.,stain normalization,cell/gland/region structure analysis).DL methods can provide consistent and accurate outcomes.DL is a promising tool to assist pathologists in clinical diagnosis.展开更多
基金supported by the National Natural Science Foundation of China[U2241273,12172034,U20A20390,11827803]Beijing Municipal Natural Science Foundation[7212205]the 111 project[B13003]]and the Fundamental Research Funds for the Central Universities.
文摘The mechanical properties of biological soft tissues are inextricably linked to the field of health care,and their mechanical properties can be important indicators for diagnosing and detecting diseases;they can also be used to analyze the causes of organ diseases from a pathological point of view and thus guide the deployment of medical solutions.As an effective method to characterize the mechanical properties of materials,mechanical loading experiments have been successfully applied to the mechanical properties of materials,including tension,compression,pure shear,and so on.Under quasi-static loading,when the material is a biological soft tissue material between a solid and an ideal fluid,its viscoelastic properties strongly respond to the force stimulus,and the stress-strain-time in the elastic phase will have obvious disturbance characteristics.Therefore,the existing statistical methods are often difficult to quantitatively describe the mechanical properties of materials.Therefore,this study proposes an Interval Capture Point based on the principle of integration.The experimental data based on this method can characterize its nonlinear mechanical properties well,especially when the loading speed is extremely low and the soft materials show strong disturbance characteristics.The proposed method can still accurately characterize the hyperelastic and viscoelastic properties of the mechanical properties of biological soft tissues under quasi-static loading.
基金National Natural Science Foundation of China(NSFC)Research Grants(U20A20390,11827803,11402017).
文摘Due to the limited capacity of corneal endothelial cells(CECs)division,corneal endothelial diseases have become a great challenge.The cornea is subjected to various mechanical stimuli in vivo,which may have a positive or negative influence.Thus,it is significant to gain an insight into the mechanism of mechanobiology of CECs for seeking more possible treatment.The purpose of this study was to determine the impacts of mechanical stretch and substrate stiffness on the morphology and fundamental cell behavior of CECs.Rabbit corneal endothelial cells(RCECs)were subjected to a 5%mechanical stretch or cultured on substrates of different stiffness.The impacts of mechanical stimulus on cell area,aspect ratio,circularity,cell density,nuclear shape,cytoskeleton,and cell viability were investigated.The expressions of the corneal endothelium-related markers ZO-1 and Na^(+)/K^(+) ATPase were also evaluated by confocal immunofluorescence microscopy in the stiffness group.Our results suggested that mechanical stretch promoted the rearrangement of the cytoskeleton while decreasing the cell circularity,nuclear area,and cell density as well as cell viability.RCECs cultured on 10 kPa substrates,which was close to the physiological stiffness of rabbit Descemet's membrane(DM),showed better cell morphology,more stable actin cytoskeleton assembly,and more robust expression of the functional marker compared with other softer or stiffer substrates.In summary,mechanical stretch and substrate stiffness have profound influences on the morphology and function of CECs,which may have implications for the understanding and possible treatment of corneal endothelial diseases.
基金National Natural Science Foundation of China(NSFC)Research Grants(61871014,52072015,31971238,52071008,U20A20390,11827803)it as also supported by National Key R&D Program of China(2017YFC0108505,2017YFC0108500)Beijing Natural Science Foundation(7191006).
文摘Some researches to facilitate wound healing by using electrical stimulation are based on electric current stimulation,which may cause secondary damage and the imbalance of the microenvironment in vivo.In this study,alternating capacitive electric field(ACEF)was applied via a self-designed system so as to avoid direct contact with cells and to maintain stable microenvironment for cell growth.The influences of 58 mV/mm ACEFs with various frequencies of 10,60 and 110 Hz on epidermal cells,fibroblasts and macrophages which involve in wound healing were comprehensively explored.The results suggested that ACEFs of 10,60 and 110 Hz all significantly promoted the proliferation of human dermal fibroblasts(HDFs)and human epidermal keratinocyte cell line(HaCaT)cells,and 60 Hz ACEF furtherly accelerated the migration of these two kinds of cells.Moreover,ACEFs of all different studied frequencies facilitated M2-type polarization of macrophages,and YAP/TAZ expression of macrophages were enhanced under the stimulations of 10 and 60 Hz ACEFs.The enhancements in cell activity,migration rate and M2-type polarizability indicated that 58 mV/mm ACEFs especially at 60 Hz possessing potentially affirmative applications for wound healing without the risks of secondary damage and microenvironment imbalance.
基金the National Natural Science Foundation of China(52171239 and T2122010 to L.Y.,32101088 to L.W.,U20A20390 and 11827803 to Y.F.)Beijing Nova Program(Z2111000021211133 to L.W.)Tsinghua University-Peking Union Medical College Hospital Initiative Scientific Research Program(20191080592 to L.Y.).
文摘Millions of people suffer from tissue diseases and organ dysfunction,such as bone or nerve defects,spinal cord injuries and arrhythmia,which often leads to morbidity and disability.Electrical stimulation as a promising nonpharmacological technique has been proven to be effective in promoting tissue regeneration and functional restoration.Nevertheless,existing clinical electrical therapies are often limited to intraoperative window or percutaneous stimulation that suffer from insufficient time frame and potential infection risks.To overcome these challenges,innovative electrical stimulation implants with miniaturized,self-powered,flexible or biodegradable features have been proposed.This review summarizes recent advances of novel materials strategies and device schemes for tissue regeneration and/or functional restoration of bones,nerves,gastrointestinal tracts,cardiac systems,etc.Insights on future directions of electrical stimulation devices are given at the end.
基金This work was supported by the National Science and Technology Major Project of the Ministry of Science and Technology of China(No.2017YFC0110903)Microsoft Research under the eHealth program+3 种基金the National Natural Science Foundation of China(No.81771910)the Beijing Natural Science Foundation in China(No.4152033)the Technology and Innovation Commission of Shenzhen in China(No.shenfagai2016-627)the Beijing Young Talent Project in China,the Fundamental Research Funds for the Central Universities of China(No.SKLSDE-2017ZX-08)from the State Key Laboratory of Software Development Environment in Beihang University in China,and the 111 Project in China(No.B13003).
文摘deep learning(DL)has achieved state-of-the-art performance in many digital pathology analysis tasks.Traditional methods usually require hand-crafted domain-specific features,and DL methods can learn representations without manually designed features.In terms of feature extraction,DL approaches are less labor intensive compared with conventional machine learning methods.In this paper,we comprehensively summarize recent DL-based image analysis studies in histopathology,including different tasks(e.g.,classification,semantic segmentation,detection,and instance segmentation)and various applications(e.g.,stain normalization,cell/gland/region structure analysis).DL methods can provide consistent and accurate outcomes.DL is a promising tool to assist pathologists in clinical diagnosis.