Diamond-like carbon (DLC) film composed of microscopically insulation but microscopically a mixture of conducting (sp2) and insulating (sp3) phases was discussed on the local modification with a conductive atomic forc...Diamond-like carbon (DLC) film composed of microscopically insulation but microscopically a mixture of conducting (sp2) and insulating (sp3) phases was discussed on the local modification with a conductive atomic force microscope (C-APM). Especially, a topographic change was observed when a direct current (DC) bias-voltage was applied to the DLC film. Experimental results show that a nanoscale pit on DLC surface was formed when applying a positive 25 V on DLC film. According to the interacting force between CoCr-coated microelectronic scanning probe (MESP) tip and DLC surface, as well as the Sondheimer oscillation theory, the 'scalewing effect' of the pit was explained. Electromechanical coupling on DLC film suggested that the depth of pits increased with an increase of load applied to surface when the cantilever-deflected signal was less than a certain threshold voltage.展开更多
Additive manufacturing-also known as 3D printing-has attracted much attention in recent years as a powerful method for the simple and versatile fabrication of complicated three-dimensional structures.However,the curre...Additive manufacturing-also known as 3D printing-has attracted much attention in recent years as a powerful method for the simple and versatile fabrication of complicated three-dimensional structures.However,the current technology still exhibits a limitation in realizing the selective deposition and sorting of various materials contained in the same reservoir,which can contribute significantly to additive printing or manufacturing by enabling simultaneous sorting and deposition of different substances through a single nozzle.Here,we propose a dielectrophoresis(DEP)-based material-selective deposition and sorting technique using a pipette-based quartz tuning fork(QTF)-atomic force microscope(AFM) platform DEPQA and demonstrate multi-material sorting through a single nozzle in ambient conditions.We used Au and silica nanoparticles for sorting and obtained 95% accuracy for spatial separation,which confirmed the surfaceenhanced Raman spectroscopy(SERS).To validate the scheme,we also performed a simulation for the system and found qualitative agreement with the experimental results.The method that combines DEP,pipette-based AFM,and SERS may widely expand the unique capabilities of 3D printing and nano-micro patterning for multi-material patterning,materials sorting,and diverse advanced applications.展开更多
Objective To observe the surface structures of cardiovascular endothelial cells in situ with atomic force microscope （AFM）. Methods Fresh aorta and aortic valve were dissected from 10 healthy male New Zealand white ...Objective To observe the surface structures of cardiovascular endothelial cells in situ with atomic force microscope （AFM）. Methods Fresh aorta and aortic valve were dissected from 10 healthy male New Zealand white rabbits. Before fixed in 1% formaldehyde, the fresh tissues were washed in the buffer phosphate solution. Under general microscope, the fixed aorta or valve was spread on the double side stick tape which had already been stuck on the glass slide. The intima of aorta or the aorta side of valve was towards upside, Then the specimen was dried under 37 degrees centigrade in an attemperator and was washed with pure water. After dried again, the specimen was loaded on the platform ofNanoScope Ⅲa AFM and was scanned in tapping mode with the scanning speed of 0.5 HZ. Results The surface structures of endothelial cell on the fixed and dried tissue could be observed clearly in situ with AFM. aortic endothelial cells were large, branched and arranged sparsely and parallel to the direction of blood flow, whereas endothelial cells on aorta valve surface were small, less branched and arranged intensively and vertical to the direction of blood flow. When the scanning range was dwindled, granular ultra-structures could be observed on the surface of endothelial cells, and, as the scanning range was dwindled further, fissure and convolution could be seen on the surface of granules from aortic endothelial cells. Centre cavity and surrounding swelling volcano-like structure could be seen on the surface of granules from endothelial cells of aortic valve. Conclusions It＇s feasible to observe the surface ultra-structures of cardiovascular endothelial cells in situ with AFM and morphological information provided by AFM might be of clinical value in future histopathological diagnosis（JGeriatr Cardiol2009; 6：178-181）.展开更多
Nanomanipulation of DNA molecules or other biomolecules to form artificial patterns or structures at nanometer scale has potential applications in the construction of molecular devices in future industries. It may als...Nanomanipulation of DNA molecules or other biomolecules to form artificial patterns or structures at nanometer scale has potential applications in the construction of molecular devices in future industries. It may also lead to new insights into the interesting properties and behavior of this fantastic nature-selected molecule at the sin- gle-molecular level. Here we present a special method based on the combination of macroscopic “molecular comb- ing” and microscopic “molecular cutting” to manipulate DNA molecules and form complex patterns at nanometer scale on solid surfaces. A possible strategy for ordered DNA sequencing based on this nanomanipulation technique has also been proposed.展开更多
An experimental and statistical study was carried out to explore the effects of mechanical forces on the ends of linear double-stranded DNA (dsDNA) fragments. Mechanical force was applied onto individual DNA molecules...An experimental and statistical study was carried out to explore the effects of mechanical forces on the ends of linear double-stranded DNA (dsDNA) fragments. Mechanical force was applied onto individual DNA molecules during atomic force microscope (AFM)-based picking-up manipulation. By comparing the PCR efficiency of two DNA fragments with primers either at ends or at the inner regions, it was found that the ends of DNA fragments were damaged during picking-up process.展开更多
原子力显微镜(Atomic force microscope,AFM)不仅可以从纳米尺度观测沥青表面微观结构,还可以应用不同模式测试其微观力学特性,是研究沥青路面材料微观特性的有力工具。沥青混合料的水损害已经成为沥青路面的主要病害之一,研究表明,沥...原子力显微镜(Atomic force microscope,AFM)不仅可以从纳米尺度观测沥青表面微观结构,还可以应用不同模式测试其微观力学特性,是研究沥青路面材料微观特性的有力工具。沥青混合料的水损害已经成为沥青路面的主要病害之一,研究表明,沥青结合料与集料之间的水分相互作用是一种出现在微观尺度,甚至纳米尺度的现象,因此从微纳观角度探究在水分存在条件下沥青与集料的结构变化,对于改善沥青混合料水稳定性能,探究其水损害机制具有深远的意义。本文在总结AFM工作原理及沥青微观“bees”结构特性的基础上,重点分析了AFM在纳米尺度上对沥青混合料水稳性能的研究成果,并探讨了AFM在沥青路面材料研究中的发展方向,为今后对于沥青路面病害研究与防治方面提供一定的借鉴。展开更多
Many environmental factors can cause DNA damage, such as radiation, heat, oxygen free radical, etc., which can induce mutation during DNA replication. Meanwhile, DNA molecules are subjected to various mechanical force...Many environmental factors can cause DNA damage, such as radiation, heat, oxygen free radical, etc., which can induce mutation during DNA replication. Meanwhile, DNA molecules are subjected to various mechanical forces in numerous biological processes. However, it is unknown whether the mechanical force would induce DNA damage and introduce mutation during DNA replication. With the combination of single-molecule manipulation based on atomic force microscopy (AFM), single molecular polymerase chain reaction (SM-PCR) and Sanger's sequencing, we investigated the effect of mechanical force on DNA. The results show that mechanical force can cause DNA damage and induce DNA mutation during amplification.展开更多
The characterization of sulfonated polyetherketone (SPEK-C) films was investigated by using positronannihilation lifetime spectroscopy (PALS) and atomic force microscopy (AFM). It was found that free volume radiusand ...The characterization of sulfonated polyetherketone (SPEK-C) films was investigated by using positronannihilation lifetime spectroscopy (PALS) and atomic force microscopy (AFM). It was found that free volume radiusand intensity depend on the variation of sulfonation degree and solvent evaporation time of the films. Pore size anddistribution determined from PALS and AFM measurements showed reasonable agreement.展开更多
综述了基于原子力显微镜的红外光谱(Atomic force microscopy-based infrared spectroscopy,AFM-IR)的特点,测量和检测原理及其技术优势。AFM-IR是能在纳米尺度对不同材料进行表征的新兴技术,该技术可以以远低于常规光学衍射极限的分辨...综述了基于原子力显微镜的红外光谱(Atomic force microscopy-based infrared spectroscopy,AFM-IR)的特点,测量和检测原理及其技术优势。AFM-IR是能在纳米尺度对不同材料进行表征的新兴技术,该技术可以以远低于常规光学衍射极限的分辨率检测材料的化学成分,同时提供不同组分的分布图谱。AFM-IR的原理是利用原子力显微镜(AFM)悬臂梁的振动检测样本因吸收红外辐射脉冲产生的热膨胀,因此AFM-IR在继承了AFM的纳米级分辨率的基础上结合了红外光谱的化学分析能力,克服了二者原有的缺点并实现了优势互补。这项新技术在过去十多年备受关注并获得了长足的发展,因其操作简便、系统稳定、样品制备要求相对较低,以及与红外光谱直接相关而无需数学建模或额外数据后续处理,已被广泛用于材料科学、生命科学等诸多领域。展开更多
DNA/octadecylamine(ODA) monolayers were transferred onto silicon substrates and the morphologies of the monolayers were investigated by Atomic Force Microscope(AFM). AFM images show that the morphologies of DNA dissol...DNA/octadecylamine(ODA) monolayers were transferred onto silicon substrates and the morphologies of the monolayers were investigated by Atomic Force Microscope(AFM). AFM images show that the morphologies of DNA dissolved in pure water are very different from those of DNA dissolved in the NaCl solution. When DNA molecules are dissovled in pure water, they will form ball-like structure in the monolayer. When the DNA molecules are dissolved in NaCl solution, they will form bunch lines. This DNA line offers a valuable template to direct the formation of unique inorganic nanomaterials.展开更多
应用原子力显微镜（atomic force microscopy,AFM）探测了静息、脂多糖（LPS）或伴刀豆蛋白（ConA）活化的人外周血淋巴细胞的形态结构、超微结构及粘滞力特性。从AFM图像可知,经LPS或ConA刺激活化后的淋巴细胞比静息状态的淋巴细胞有...应用原子力显微镜（atomic force microscopy,AFM）探测了静息、脂多糖（LPS）或伴刀豆蛋白（ConA）活化的人外周血淋巴细胞的形态结构、超微结构及粘滞力特性。从AFM图像可知,经LPS或ConA刺激活化后的淋巴细胞比静息状态的淋巴细胞有所增大,并且表面分布着大小不一的颗粒状聚合物。利用AFM高空间分辨的力位移曲线测量系统,发现经LPS或ConA刺激活化后淋巴细胞的粘滞力是静息状态淋巴细胞的2~3倍。通过AFM探测淋巴细胞活化状态的可视化数据,可以更好地理解淋巴细胞的行为。展开更多
基金The project supported by the Special Fund and Open Foundation of Micro/Nano Technology Center of Jiangsu University (No. 1291400001)
文摘Diamond-like carbon (DLC) film composed of microscopically insulation but microscopically a mixture of conducting (sp2) and insulating (sp3) phases was discussed on the local modification with a conductive atomic force microscope (C-APM). Especially, a topographic change was observed when a direct current (DC) bias-voltage was applied to the DLC film. Experimental results show that a nanoscale pit on DLC surface was formed when applying a positive 25 V on DLC film. According to the interacting force between CoCr-coated microelectronic scanning probe (MESP) tip and DLC surface, as well as the Sondheimer oscillation theory, the 'scalewing effect' of the pit was explained. Electromechanical coupling on DLC film suggested that the depth of pits increased with an increase of load applied to surface when the cantilever-deflected signal was less than a certain threshold voltage.
基金Open access funding provided by Shanghai Jiao Tong University。
文摘Additive manufacturing-also known as 3D printing-has attracted much attention in recent years as a powerful method for the simple and versatile fabrication of complicated three-dimensional structures.However,the current technology still exhibits a limitation in realizing the selective deposition and sorting of various materials contained in the same reservoir,which can contribute significantly to additive printing or manufacturing by enabling simultaneous sorting and deposition of different substances through a single nozzle.Here,we propose a dielectrophoresis(DEP)-based material-selective deposition and sorting technique using a pipette-based quartz tuning fork(QTF)-atomic force microscope(AFM) platform DEPQA and demonstrate multi-material sorting through a single nozzle in ambient conditions.We used Au and silica nanoparticles for sorting and obtained 95% accuracy for spatial separation,which confirmed the surfaceenhanced Raman spectroscopy(SERS).To validate the scheme,we also performed a simulation for the system and found qualitative agreement with the experimental results.The method that combines DEP,pipette-based AFM,and SERS may widely expand the unique capabilities of 3D printing and nano-micro patterning for multi-material patterning,materials sorting,and diverse advanced applications.
文摘Objective To observe the surface structures of cardiovascular endothelial cells in situ with atomic force microscope （AFM）. Methods Fresh aorta and aortic valve were dissected from 10 healthy male New Zealand white rabbits. Before fixed in 1% formaldehyde, the fresh tissues were washed in the buffer phosphate solution. Under general microscope, the fixed aorta or valve was spread on the double side stick tape which had already been stuck on the glass slide. The intima of aorta or the aorta side of valve was towards upside, Then the specimen was dried under 37 degrees centigrade in an attemperator and was washed with pure water. After dried again, the specimen was loaded on the platform ofNanoScope Ⅲa AFM and was scanned in tapping mode with the scanning speed of 0.5 HZ. Results The surface structures of endothelial cell on the fixed and dried tissue could be observed clearly in situ with AFM. aortic endothelial cells were large, branched and arranged sparsely and parallel to the direction of blood flow, whereas endothelial cells on aorta valve surface were small, less branched and arranged intensively and vertical to the direction of blood flow. When the scanning range was dwindled, granular ultra-structures could be observed on the surface of endothelial cells, and, as the scanning range was dwindled further, fissure and convolution could be seen on the surface of granules from aortic endothelial cells. Centre cavity and surrounding swelling volcano-like structure could be seen on the surface of granules from endothelial cells of aortic valve. Conclusions It＇s feasible to observe the surface ultra-structures of cardiovascular endothelial cells in situ with AFM and morphological information provided by AFM might be of clinical value in future histopathological diagnosis（JGeriatr Cardiol2009; 6：178-181）.
基金Supported by National Natural Science Foundation of China (NSFC) under grant No.10335070. Financial support from the Chinese Academy of Sciences and Shanghai Scientific and Technological Committee is also appreciated.
文摘Nanomanipulation of DNA molecules or other biomolecules to form artificial patterns or structures at nanometer scale has potential applications in the construction of molecular devices in future industries. It may also lead to new insights into the interesting properties and behavior of this fantastic nature-selected molecule at the sin- gle-molecular level. Here we present a special method based on the combination of macroscopic “molecular comb- ing” and microscopic “molecular cutting” to manipulate DNA molecules and form complex patterns at nanometer scale on solid surfaces. A possible strategy for ordered DNA sequencing based on this nanomanipulation technique has also been proposed.
基金Supported by the Major State Basic Research Development Program in China (No.2007CB936000)Chinese Academy of Sciences (No. KJCX2-EW-N03)National Science Foundation of China (Nos.10975175, 90923002, 21073222 and 10874198)
文摘An experimental and statistical study was carried out to explore the effects of mechanical forces on the ends of linear double-stranded DNA (dsDNA) fragments. Mechanical force was applied onto individual DNA molecules during atomic force microscope (AFM)-based picking-up manipulation. By comparing the PCR efficiency of two DNA fragments with primers either at ends or at the inner regions, it was found that the ends of DNA fragments were damaged during picking-up process.
文摘原子力显微镜(Atomic force microscope,AFM)不仅可以从纳米尺度观测沥青表面微观结构,还可以应用不同模式测试其微观力学特性,是研究沥青路面材料微观特性的有力工具。沥青混合料的水损害已经成为沥青路面的主要病害之一,研究表明,沥青结合料与集料之间的水分相互作用是一种出现在微观尺度,甚至纳米尺度的现象,因此从微纳观角度探究在水分存在条件下沥青与集料的结构变化,对于改善沥青混合料水稳定性能,探究其水损害机制具有深远的意义。本文在总结AFM工作原理及沥青微观“bees”结构特性的基础上,重点分析了AFM在纳米尺度上对沥青混合料水稳性能的研究成果,并探讨了AFM在沥青路面材料研究中的发展方向,为今后对于沥青路面病害研究与防治方面提供一定的借鉴。
基金Supported by National Basic Research Program of China(973 Program Nos.2007CB936000 and 2012CB932600)National Natural Science Foundation of China(No.21073222)Chinese Academy of Sciences(No.KJCX2-EW-N03)
文摘Many environmental factors can cause DNA damage, such as radiation, heat, oxygen free radical, etc., which can induce mutation during DNA replication. Meanwhile, DNA molecules are subjected to various mechanical forces in numerous biological processes. However, it is unknown whether the mechanical force would induce DNA damage and introduce mutation during DNA replication. With the combination of single-molecule manipulation based on atomic force microscopy (AFM), single molecular polymerase chain reaction (SM-PCR) and Sanger's sequencing, we investigated the effect of mechanical force on DNA. The results show that mechanical force can cause DNA damage and induce DNA mutation during amplification.
文摘The characterization of sulfonated polyetherketone (SPEK-C) films was investigated by using positronannihilation lifetime spectroscopy (PALS) and atomic force microscopy (AFM). It was found that free volume radiusand intensity depend on the variation of sulfonation degree and solvent evaporation time of the films. Pore size anddistribution determined from PALS and AFM measurements showed reasonable agreement.
文摘综述了基于原子力显微镜的红外光谱(Atomic force microscopy-based infrared spectroscopy,AFM-IR)的特点,测量和检测原理及其技术优势。AFM-IR是能在纳米尺度对不同材料进行表征的新兴技术,该技术可以以远低于常规光学衍射极限的分辨率检测材料的化学成分,同时提供不同组分的分布图谱。AFM-IR的原理是利用原子力显微镜(AFM)悬臂梁的振动检测样本因吸收红外辐射脉冲产生的热膨胀,因此AFM-IR在继承了AFM的纳米级分辨率的基础上结合了红外光谱的化学分析能力,克服了二者原有的缺点并实现了优势互补。这项新技术在过去十多年备受关注并获得了长足的发展,因其操作简便、系统稳定、样品制备要求相对较低,以及与红外光谱直接相关而无需数学建模或额外数据后续处理,已被广泛用于材料科学、生命科学等诸多领域。
文摘DNA/octadecylamine(ODA) monolayers were transferred onto silicon substrates and the morphologies of the monolayers were investigated by Atomic Force Microscope(AFM). AFM images show that the morphologies of DNA dissolved in pure water are very different from those of DNA dissolved in the NaCl solution. When DNA molecules are dissovled in pure water, they will form ball-like structure in the monolayer. When the DNA molecules are dissolved in NaCl solution, they will form bunch lines. This DNA line offers a valuable template to direct the formation of unique inorganic nanomaterials.
文摘应用原子力显微镜（atomic force microscopy,AFM）探测了静息、脂多糖（LPS）或伴刀豆蛋白（ConA）活化的人外周血淋巴细胞的形态结构、超微结构及粘滞力特性。从AFM图像可知,经LPS或ConA刺激活化后的淋巴细胞比静息状态的淋巴细胞有所增大,并且表面分布着大小不一的颗粒状聚合物。利用AFM高空间分辨的力位移曲线测量系统,发现经LPS或ConA刺激活化后淋巴细胞的粘滞力是静息状态淋巴细胞的2~3倍。通过AFM探测淋巴细胞活化状态的可视化数据,可以更好地理解淋巴细胞的行为。
