Surface wettability is important to design biointerfaces and fimctional biomaterials in various biological applications. However, to date, it remains some confusions about how cells would response to the surfaces with...Surface wettability is important to design biointerfaces and fimctional biomaterials in various biological applications. However, to date, it remains some confusions about how cells would response to the surfaces with different wettabilities. Herein, we systematically explore the adhesive spectra of cells to the surface with wettability gradient from superhydrophilicity to superhydrophobicity, clarifying the effect of wettability on cell adhesion. We envision that this study may provide valuable information for the design of biomedical implants with controllable cell adhesion, such as neural interface devices and flexible implant.展开更多
Underwater adhesion is greatly desired in tissue transplantation, medical treatment, ocean transportation, and so on. However, common commercial polymeric adhesives are rather weakened and easily destroyed in water en...Underwater adhesion is greatly desired in tissue transplantation, medical treatment, ocean transportation, and so on. However, common commercial polymeric adhesives are rather weakened and easily destroyed in water envi- ronment. In nature, some marine organisms, such as mussels, barnacles, or tube worms, exhibiting excellent under- water adhesion up to robust bonding on the rock of sea floor, can give exciting solutions to address the problem. Among these marine organisms, mussels exhibit unique underwater adhesion via the foot proteins of byssus. It has been verified that the catechol groups from the side chain of the mussel foot proteins is the main contribution to the unique underwater adhesion. Hence, inspired by the mussels＇ underwater adhesion, many mussel-mimetic polymers with catechol as end chains or side chains have been developed in the past decades. Here, we review recent progress of mussel-inspired underwater adhesives polymers from their catechol-functional design to their potential applica- tions in intermediates, anti-biofouling, self-healing of hydrogels, biological adhesives, and drug delivery. The re- view may provide basis and help for the development of the commercial underwater adhesives.展开更多
Deep shale gas reservoirs commonly contain connate water, which affects the enrichment and migration of shale gas and has attracted the attention of many scholars. It is significant to quantitatively estimate the amou...Deep shale gas reservoirs commonly contain connate water, which affects the enrichment and migration of shale gas and has attracted the attention of many scholars. It is significant to quantitatively estimate the amounts of adsorbed and free water in shale matrix pores, considering the different impacts of pore water (adsorbed water and free water) on shale gas. In this paper, pore water in six deep shale samples from the Wufeng-Longmaxi Formations in the Luzhou area, southern Sichuan Basin, China, was quantitatively evaluated by saturation-centrifugation experiments. Further, the impact of shale material composition and microstructure on the pore water occurrence was analyzed. The results show that amounts of adsorbed and free water are respectively 1.7967–9.8218 mg/g (mean 6.4501 mg/g) and 9.5511–19.802 mg/g (mean 13.9541 mg/g) under the experimental conditions (30℃, distilled water). The ratio of adsorbed water to total water is 15.83%–42.61% (mean 30.45%). The amounts of adsorbed and free water are related to the pore microstructure and material compositions of shale. The specific surface area of shale controls the amount of adsorbed water, and the pore volume controls the amount of free water;organic pores developed in shale solid asphalt contribute specific surface area and pore volume, and inorganic pores developed in clay mineral contribute pore volume. Therefore, the pores of shale solid asphalt accumulate the adsorbed water and free water, and the pores of clay minerals mainly accumulate the free water.展开更多
Studying the wetting behaviors of multicellular spheroids is crucial in the fields of embryo implantation, cancer propagation, and tissue repair. Existing strategies for controlling the wetting of multicellular sphero...Studying the wetting behaviors of multicellular spheroids is crucial in the fields of embryo implantation, cancer propagation, and tissue repair. Existing strategies for controlling the wetting of multicellular spheroids mainly focus on surface chemistry and substrate rigidity. Although topography is another important feature in the biological micro-environment, its effect on multicellular spheroid wetting has seldom been explored. In this study, the influence of topography on the surface wetting of multicellular spheroids was investigated using subcellular- patterned opal films with controllable colloidal particle diameters （from 200 to 1,500 nm）. The wetting of hepatoma carcinoma cellular （Hep G2） spheroids was impaired on opal films compared with that on flat substrates, and the wetting rate decreased as colloidal particle diameter increased. The decrement reached 48.5% when the colloidal particle diameter was 1,500 nm. The subcellular-patterned topography in opal films drastically reduced the cellular mobility in precursor films, especially the frontier cells in the leading edge. The frontier cells failed to form mature focal adhesions and stress fibers on micro-patterned opal films. This was due to gaps between colloidal particles leaving adhesion vacancies, causing weak cell-substrate adhesion and consequent retarded migration of Hep G2 spheroids. Our study manifests the inhibiting effects of subcellular-patterned topography on the wetting behaviors of multicellular spheroids, providing new insight into tissue wetting-associated treatments and biomaterial design.展开更多
The self‐assembly of block copolymers(BCPs)within emulsion droplets is a flexible strategy for the preparation of polymer particles.This strategy permits the finetuning of shapes,internal structures,and surface nanos...The self‐assembly of block copolymers(BCPs)within emulsion droplets is a flexible strategy for the preparation of polymer particles.This strategy permits the finetuning of shapes,internal structures,and surface nanostructures of the polymer particles,thus allowing many applications.Although some literature has reviewed the BCP preparation via self‐assembly within a droplet,a comprehensive summary including in‐depth understanding,controllable preparation,and application is lacked.In this review,we systematically delve into the multiple mechanisms that drive BCP self‐assembly within emulsion droplets,such as commensurability effects for minimizing total free energy,interfacial instability,organized spontaneous emulsification,phase separation of multiple components,and entropy effects between BCPs and nanoparticles.Additionally,a strategy combining selective cross‐linking and disassembly can further generate Janus particles featuring unique structures.Next,various applications across multiple disciplines are discussed,including drug delivery,display,biomedical imaging,macromolecular separation,and fuel cells.Finally,we present an overview of the current challenges and future directions for BCP emulsion self‐assembly,covering mechanism investigation,molecular design,stability control,and application exploration.We anticipate deeper understanding,more varieties,enhanced performance,and broader applications can be achieved with BCP emulsion self‐assembly after addressing the challenge.展开更多
Hydrogels are among the most promising biologic materials in recent technology with numerous desired applications,including serving as biosensors,drug delivery vehicles,and tissue-engineered products for cell matrices...Hydrogels are among the most promising biologic materials in recent technology with numerous desired applications,including serving as biosensors,drug delivery vehicles,and tissue-engineered products for cell matrices.However,they often dehydrate,and become stiff and brittle in air,causing loss of flexibility and functions.Several layered structures have been proven to increase the strength,toughness,and even flexibility of these materials,which might provide a new clue for the sustenance of the flexibility of drying gels.Herein,we report a novel solvent-dehydrated hydrogel engineering approach,aimed to change the inner structure and keep the flexibility of a dehydrated hydrogel in the air via solvent-induced dehydration,for example,acetonedehydrated polyacrylic acid hydrogel.This flexible dry gel could be folded,twisted,and stretched without any damage due to the assumed lamella-like structures,contrary to dry gels without these microstructures or those with porous structures,which retain brittle consistency.The flexible dry gel also exhibited excellent self-healing capability with the assistance of solvents.Fascinatingly,this flexible gel film displayed strain-visualizing paper writing/erasing performance properties,with water acting as invisible ink.Thus,this fabricated flexible hydrogel film might function as confidential information storage material.Our current approach is versatile,hence applicable to other hydrogels,and provides insight into the engineering of other functional gels for extended future applications.展开更多
针对特定应用场景下,Tiny-YOLOv3(You Only Look Once v3)网络在嵌入式平台部署时存在资源开销大、运行速度慢的问题,文中提出了一种结合剪枝与量化的结构化压缩方案,并搭建了针对压缩后网络的卷积层加速系统。结构化压缩方案使用稀疏...针对特定应用场景下,Tiny-YOLOv3(You Only Look Once v3)网络在嵌入式平台部署时存在资源开销大、运行速度慢的问题,文中提出了一种结合剪枝与量化的结构化压缩方案,并搭建了针对压缩后网络的卷积层加速系统。结构化压缩方案使用稀疏化训练与通道剪枝来减少网络中的计算量,使用激活值定点数量化和权重二的整数次幂量化来减少网络卷积层中的参数存储量。在卷积层加速系统中,可编程逻辑部分按照并行加流水线方法设计了一个卷积层加速器核,处理系统部分负责卷积层加速系统调度。实验结果表明,Tiny-YOLOv3经过结构化压缩后的网络平均准确度为0.46,参数压缩率达到了5%。卷积层加速系统在Xilinx的ZYNQ芯片进行部署时,硬件可以稳定运行在250 MHz时钟频率下,卷积运算单元的算力为36 GOPS。此外,加速平台整体功耗为2.6 W,且硬件设计节约了硬件资源。展开更多
基金supported by the National Natural Science Foundation of China(21425314,21501184,21434009,21421061,21504098)the Key Research Program of the Chinese Academy of Sciences(KJZD-EW-M01)+2 种基金Ministry of Science and Technology(2013YQ190467)the Top-Notch Young Talents Program of ChinaBeijing Municipal Science&Technology Commission(Z161100000116037)
文摘Surface wettability is important to design biointerfaces and fimctional biomaterials in various biological applications. However, to date, it remains some confusions about how cells would response to the surfaces with different wettabilities. Herein, we systematically explore the adhesive spectra of cells to the surface with wettability gradient from superhydrophilicity to superhydrophobicity, clarifying the effect of wettability on cell adhesion. We envision that this study may provide valuable information for the design of biomedical implants with controllable cell adhesion, such as neural interface devices and flexible implant.
基金This review is supported by the National Natural Science Foundation of China （Nos. 21425314, 21501184, 21434009, 21421061 and 21504098）, the Key Research Program of the Chinese Academy of Sci- ences （No. KJZD-EW-M01 ）, MOST （No. 2013YQI90467）, the Top-Notch Young Talents Pro- gram of China, and Beijing Municipal Science ＆ Tech- nology Commission （No. Z161100000116037）.
文摘Underwater adhesion is greatly desired in tissue transplantation, medical treatment, ocean transportation, and so on. However, common commercial polymeric adhesives are rather weakened and easily destroyed in water envi- ronment. In nature, some marine organisms, such as mussels, barnacles, or tube worms, exhibiting excellent under- water adhesion up to robust bonding on the rock of sea floor, can give exciting solutions to address the problem. Among these marine organisms, mussels exhibit unique underwater adhesion via the foot proteins of byssus. It has been verified that the catechol groups from the side chain of the mussel foot proteins is the main contribution to the unique underwater adhesion. Hence, inspired by the mussels＇ underwater adhesion, many mussel-mimetic polymers with catechol as end chains or side chains have been developed in the past decades. Here, we review recent progress of mussel-inspired underwater adhesives polymers from their catechol-functional design to their potential applica- tions in intermediates, anti-biofouling, self-healing of hydrogels, biological adhesives, and drug delivery. The re- view may provide basis and help for the development of the commercial underwater adhesives.
基金supported by the National Natural Science Foundation of China (Grant No. 41972123).
文摘Deep shale gas reservoirs commonly contain connate water, which affects the enrichment and migration of shale gas and has attracted the attention of many scholars. It is significant to quantitatively estimate the amounts of adsorbed and free water in shale matrix pores, considering the different impacts of pore water (adsorbed water and free water) on shale gas. In this paper, pore water in six deep shale samples from the Wufeng-Longmaxi Formations in the Luzhou area, southern Sichuan Basin, China, was quantitatively evaluated by saturation-centrifugation experiments. Further, the impact of shale material composition and microstructure on the pore water occurrence was analyzed. The results show that amounts of adsorbed and free water are respectively 1.7967–9.8218 mg/g (mean 6.4501 mg/g) and 9.5511–19.802 mg/g (mean 13.9541 mg/g) under the experimental conditions (30℃, distilled water). The ratio of adsorbed water to total water is 15.83%–42.61% (mean 30.45%). The amounts of adsorbed and free water are related to the pore microstructure and material compositions of shale. The specific surface area of shale controls the amount of adsorbed water, and the pore volume controls the amount of free water;organic pores developed in shale solid asphalt contribute specific surface area and pore volume, and inorganic pores developed in clay mineral contribute pore volume. Therefore, the pores of shale solid asphalt accumulate the adsorbed water and free water, and the pores of clay minerals mainly accumulate the free water.
基金This research is supported by National Natural Science Foundation of China （Nos. 21425314, 21434009, and 21421061）, National Program for Special Support of Eminent Professionals, Beijing Municipal Science ＆ Technology Commission （No. Z161100000116037）, and MOST （No. 2013YQ190467）.
文摘Studying the wetting behaviors of multicellular spheroids is crucial in the fields of embryo implantation, cancer propagation, and tissue repair. Existing strategies for controlling the wetting of multicellular spheroids mainly focus on surface chemistry and substrate rigidity. Although topography is another important feature in the biological micro-environment, its effect on multicellular spheroid wetting has seldom been explored. In this study, the influence of topography on the surface wetting of multicellular spheroids was investigated using subcellular- patterned opal films with controllable colloidal particle diameters （from 200 to 1,500 nm）. The wetting of hepatoma carcinoma cellular （Hep G2） spheroids was impaired on opal films compared with that on flat substrates, and the wetting rate decreased as colloidal particle diameter increased. The decrement reached 48.5% when the colloidal particle diameter was 1,500 nm. The subcellular-patterned topography in opal films drastically reduced the cellular mobility in precursor films, especially the frontier cells in the leading edge. The frontier cells failed to form mature focal adhesions and stress fibers on micro-patterned opal films. This was due to gaps between colloidal particles leaving adhesion vacancies, causing weak cell-substrate adhesion and consequent retarded migration of Hep G2 spheroids. Our study manifests the inhibiting effects of subcellular-patterned topography on the wetting behaviors of multicellular spheroids, providing new insight into tissue wetting-associated treatments and biomaterial design.
基金National Key R&D Program of China,Grant/Award Numbers:2022YFA1206900,2019YFA0709300National Natural Science Foundation of China,Grant/Award Number:22035008+1 种基金Key Research Program of the Chinese Academy of Sciences,Grant/Award Number:XDPB24International Partnership Program of Chinese Academy of Sciences,Grant/Award Number:1A1111KYSB20200010。
文摘The self‐assembly of block copolymers(BCPs)within emulsion droplets is a flexible strategy for the preparation of polymer particles.This strategy permits the finetuning of shapes,internal structures,and surface nanostructures of the polymer particles,thus allowing many applications.Although some literature has reviewed the BCP preparation via self‐assembly within a droplet,a comprehensive summary including in‐depth understanding,controllable preparation,and application is lacked.In this review,we systematically delve into the multiple mechanisms that drive BCP self‐assembly within emulsion droplets,such as commensurability effects for minimizing total free energy,interfacial instability,organized spontaneous emulsification,phase separation of multiple components,and entropy effects between BCPs and nanoparticles.Additionally,a strategy combining selective cross‐linking and disassembly can further generate Janus particles featuring unique structures.Next,various applications across multiple disciplines are discussed,including drug delivery,display,biomedical imaging,macromolecular separation,and fuel cells.Finally,we present an overview of the current challenges and future directions for BCP emulsion self‐assembly,covering mechanism investigation,molecular design,stability control,and application exploration.We anticipate deeper understanding,more varieties,enhanced performance,and broader applications can be achieved with BCP emulsion self‐assembly after addressing the challenge.
基金This study is supported financially by the National Natural Science Foundation of China(21425314,21501184,21434009,21421061,and 21504098)the Top-Notch Young Talents Program of China,Beijing Municipal Science&Technology Commission(Z161100000116037)Youth Innovation Promotion Association,CAS(2017036).F.Z.designed and performed all the experiments.S.W.codesigned the experiments.Z.G.,M.Y.,S.L.,Y.S.,J.F.,and J.M.conducted or supported the experiments for characterization.J.Z.conducted the thermodynamic analysis of the hydrogel in poor solvent.F.Z.,L.J.,P.W.,and S.W.analyzed the data.F.Z.and S.W.wrote the article.
文摘Hydrogels are among the most promising biologic materials in recent technology with numerous desired applications,including serving as biosensors,drug delivery vehicles,and tissue-engineered products for cell matrices.However,they often dehydrate,and become stiff and brittle in air,causing loss of flexibility and functions.Several layered structures have been proven to increase the strength,toughness,and even flexibility of these materials,which might provide a new clue for the sustenance of the flexibility of drying gels.Herein,we report a novel solvent-dehydrated hydrogel engineering approach,aimed to change the inner structure and keep the flexibility of a dehydrated hydrogel in the air via solvent-induced dehydration,for example,acetonedehydrated polyacrylic acid hydrogel.This flexible dry gel could be folded,twisted,and stretched without any damage due to the assumed lamella-like structures,contrary to dry gels without these microstructures or those with porous structures,which retain brittle consistency.The flexible dry gel also exhibited excellent self-healing capability with the assistance of solvents.Fascinatingly,this flexible gel film displayed strain-visualizing paper writing/erasing performance properties,with water acting as invisible ink.Thus,this fabricated flexible hydrogel film might function as confidential information storage material.Our current approach is versatile,hence applicable to other hydrogels,and provides insight into the engineering of other functional gels for extended future applications.
文摘针对特定应用场景下,Tiny-YOLOv3(You Only Look Once v3)网络在嵌入式平台部署时存在资源开销大、运行速度慢的问题,文中提出了一种结合剪枝与量化的结构化压缩方案,并搭建了针对压缩后网络的卷积层加速系统。结构化压缩方案使用稀疏化训练与通道剪枝来减少网络中的计算量,使用激活值定点数量化和权重二的整数次幂量化来减少网络卷积层中的参数存储量。在卷积层加速系统中,可编程逻辑部分按照并行加流水线方法设计了一个卷积层加速器核,处理系统部分负责卷积层加速系统调度。实验结果表明,Tiny-YOLOv3经过结构化压缩后的网络平均准确度为0.46,参数压缩率达到了5%。卷积层加速系统在Xilinx的ZYNQ芯片进行部署时,硬件可以稳定运行在250 MHz时钟频率下,卷积运算单元的算力为36 GOPS。此外,加速平台整体功耗为2.6 W,且硬件设计节约了硬件资源。
