The recent discovery of field emission devices based on one-dimensional nanostructures has attracted much interest in emerging applications on next-generation flat panel displays,molecule-based sensors,and so forth.To...The recent discovery of field emission devices based on one-dimensional nanostructures has attracted much interest in emerging applications on next-generation flat panel displays,molecule-based sensors,and so forth.To achieve a comprehensive understanding of surface potentials at the nano-emitters during the tunneling process,in this study we systematically investigated the image potentials of single-walled boron nitride nanotubes with different edges,diameters and lengths in the frame of a composite first-principles calculation.The image potentials of zigzag single-walled boron nitride nanotubes are found to be dependent on the non-equivalent sides.Only the image potentials of isolated armchair single-walled boron nitride nanotube can be well fitted with the image potential of an ideal metal sphere of a size comparable to the tube diameter.On the contrary,the image potentials of zigzag and grounded armchair single-walled boron nitride nanotubes exhibit a strong length-dependence characteristic and are significantly different from that of an ideal metal sphere,which originates from the significant axial symmetry breaking of induced charge at the tip for the long tube.The correlation between the testing electron and electronic structure of single-walled boron nitride nanotube has also been discussed.展开更多
The adsorption and electronic properties of isolated cobalt phthalocyanine （CoPc） molecule on an ultrathin layer of NaC1 have been investigated. High-resolution STM images give a detailed picture of the lowest unocc...The adsorption and electronic properties of isolated cobalt phthalocyanine （CoPc） molecule on an ultrathin layer of NaC1 have been investigated. High-resolution STM images give a detailed picture of the lowest unoccupied molecular orbital （LUMO） of an isolated CoPc. It is shown that the NaC1 ultrathin layer efficiently decouples the interaction of the molecules from the underneath metal substrate, which makes it an ideal substrate for studying the properties of single molecules. Moreover, strong dependence of the appearance of the molecules on the sample bias in the region of relatively high bias （〉 3.1 V） is ascribed to the image potential states （IPSs） of NaCI/Cu（100）, which may provide us with a possible method to fabricate quantum storage devices.展开更多
The quality of the scanning tip is crucial for tip-enhanced Raman spectroscopy(TERS)experiments towards large signal enhancement and high spatial resolution.In this work,we report a controllable fabrication method to ...The quality of the scanning tip is crucial for tip-enhanced Raman spectroscopy(TERS)experiments towards large signal enhancement and high spatial resolution.In this work,we report a controllable fabrication method to prepare TERS-active tips by modifying the tip apex at the atomic scale,and propose two important criteria to in-situ judge the tip’s TERS activity for tip-enhanced Raman measurements.One criterion is based on the downshift of the first image potential state to monitor the coupling between the far-field incident laser and near-field plasmon;the other is based on the appearance of the low-wavenumber Raman peaks associated with an atomistic protrusion at the tip apex to judge the coupling efficiency of emissions from the near field to the far field.This work provides an effective method to quickly fabricate and judge TERS-active tips before real TERS experiments on target molecules and other materials,which is believed to be instrumental for the development of TERS and other tip-enhanced spectroscopic techniques.展开更多
The problem of the elastic interaction between a screw dislocation and a three-phase circular inclusion with interracial rigid lines （anti-cracks） is investigated. An efficient and concise method for the complex mul...The problem of the elastic interaction between a screw dislocation and a three-phase circular inclusion with interracial rigid lines （anti-cracks） is investigated. An efficient and concise method for the complex multiply connected region is developed, with which explicit series form solutions of the complex potentials in the matrix, and the interphase layer and inclusion regions are derived. Based on the complex potentials, the image force on the screw dislocation is then calculated by using the Peach-Koehler formula. The equilibrium position of the dislocation is discussed in detail for various rigid line geometries, interphase layer thicknesses and material property combinations. The main results show that the interracial rigid lines exert a significant perturbation effect on the motion of the screw dislocation near the circular inclusion surrounded by an interphase layer.展开更多
A new multivariate statistical strategy for analyzing large datasets that are produced by imaging mass spectrometry（IMS） techniques is reported.The strategy divides the whole datacube of the sample into several subs...A new multivariate statistical strategy for analyzing large datasets that are produced by imaging mass spectrometry（IMS） techniques is reported.The strategy divides the whole datacube of the sample into several subsets and analyses them one by one to obtain the results.Instead of analyzing the whole datacube at one time,the strategy makes the analysis easier and decreases the computation time greatly.In this report,the IMS data are produced by the air flow-assisted ionization IMS（AFAI-IMS）.The strategy can be used in combination with most multivariate statistical analysis methods.In this paper,the strategy was combined with the principal component analysis（PCA） and partial least square analysis（PLS）.It was proven to be effective by analyzing the handwriting sample.By using the strategy,the m/z corresponding to the specific lipids in rat brain tissue were distinguished successfully.Moreover the analysis time grew linearly instead of exponentially as the size of sample increased.The strategy developed in this study has enormous potential for searching for the mjz of potential biomarkers quickly and effectively.展开更多
Targeted-delivery is of great importance to molecular probes and drugs for cell biology study. Herein we reported 11 sulfur-containing coumarins as cell imaging probes. Different sulfur speciation of the 4 representat...Targeted-delivery is of great importance to molecular probes and drugs for cell biology study. Herein we reported 11 sulfur-containing coumarins as cell imaging probes. Different sulfur speciation of the 4 representative coumarins SC1-SC4 renders them significantly different subcellular localizations and cellular uptake pathways： SC1 containing thioether group located in lysosomes, while sulfoxide and sulfone compounds SC2 and SC3 distributed in the whole cell. Furthermore, the cationic sulfonium containing compound SC4 was internalized by clathrin-mediated endocytosis and localized at mitochondria. By analyzing the molecular parameters of all 11 coumarins, we found that different sulfur speciation affected their lipophilicity and electrostatic surface potential. These two key factors play roles in altering biological behaviors of the coumarins. The results revealed the importance of sulfur speciation on the physicochemical properties and thus subcellular localization of bioprobes. This is useful for designing new functional bioprobes.展开更多
The combination of electroencephalogram (EEG) and functional magnetic resonance imaging(fMRI) is a very attractive aim in neuroscience in order to achieve both high temporal and spatial resolution for the non-invasive...The combination of electroencephalogram (EEG) and functional magnetic resonance imaging(fMRI) is a very attractive aim in neuroscience in order to achieve both high temporal and spatial resolution for the non-invasive study of cognitive brain function. In this paper, we record simultaneous EEG-fMRI of the same subject in emotional processing experiment in order to explore the characteristics of different emotional picture processing, and try to find the difference of the subjects' brain hemisphere while viewing different valence emotional pictures. The late positive potential(LPP) is a reliable electrophysiological index of emotional perception in humans. According to the analysis results, the slow-wave LPP and visual cortical blood oxygen level-dependent (BOLD) signals are both modulated by the rated intensity of picture arousal. The amplitude of the LPP correlate significantly with BOLD intensity in visual cortex, amygdala, temporal area, prefrontal and central areas across picture contents.展开更多
Unfolded proteins,as critical biomarkers in cancer,hold significant potential for tumor-specific imaging.However,the content of unfolded proteins within distinct subcellular organelles varies markedly and reflects div...Unfolded proteins,as critical biomarkers in cancer,hold significant potential for tumor-specific imaging.However,the content of unfolded proteins within distinct subcellular organelles varies markedly and reflects divergent physiological implications.Currently,few fluorescent probes enable precise quantification and imaging of mitochondrial unfolded proteins.Herein,we report a fluorescent probe,MAP,for accurate imaging of mitochondrial unfolded proteins.MAP incorporates a triphenylphosphonium group that specifically targets mitochondria,with cellular uptake efficiency proportional to mitochondrial membranepotential.Within mitochondria,the maleimide moiety of MAP covalently reacts with thiol groups on unfolded proteins,restricting molecular rotation and suppressing intramolecular charge transfer(ICT),thereby triggering a significant fluorescence enhancement.Owing to the hyperpolarized mitochondrialmembrane potential and abundant mitochondrialunfolded proteins in SKOV3 cells,MAP with superior biocompatibilityachieves tumor-specific imaging with a high signal-to-noise ratio(9.5),enabling precise intraoperative navigation for ovarian cancer resection.This molecular design strategy provides a foundational framework for developing organelle-specific unfolded protein probes and advancing image-guided surgical applications.展开更多
基金the financial support from the National Natural Science Foundation of China(Grant Nos.12004083 and 51972069)the Science and Technology Projects in Guangzhou(Grant Nos.202102020350 and 202102010470)+7 种基金the National Key R&D Program of China(Grant No.2016YFB0200800)the Opening Project of Joint Laboratory for Planetary Science and Supercomputing(Grant No.CSYYGS-QT-2024-14)the Key-Area Research and Development Program of Guangdong Province(Grant No.2019B030330001)the College Students Innovation and Entrepreneurship Training Program of Guangdong Province(Grant No.S202311078133)Key Discipline of Materials Science and Engineering,Bureau of Education of Guangzhou(Grant No.202255464)the National Supercomputer Center in Guangzhouthe National Supercomputing Center in Chengduthe Network Center of Guangzhou University。
文摘The recent discovery of field emission devices based on one-dimensional nanostructures has attracted much interest in emerging applications on next-generation flat panel displays,molecule-based sensors,and so forth.To achieve a comprehensive understanding of surface potentials at the nano-emitters during the tunneling process,in this study we systematically investigated the image potentials of single-walled boron nitride nanotubes with different edges,diameters and lengths in the frame of a composite first-principles calculation.The image potentials of zigzag single-walled boron nitride nanotubes are found to be dependent on the non-equivalent sides.Only the image potentials of isolated armchair single-walled boron nitride nanotube can be well fitted with the image potential of an ideal metal sphere of a size comparable to the tube diameter.On the contrary,the image potentials of zigzag and grounded armchair single-walled boron nitride nanotubes exhibit a strong length-dependence characteristic and are significantly different from that of an ideal metal sphere,which originates from the significant axial symmetry breaking of induced charge at the tip for the long tube.The correlation between the testing electron and electronic structure of single-walled boron nitride nanotube has also been discussed.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.21203239 and 21311120059)RFBR(Grant No.13-02-91180)
文摘The adsorption and electronic properties of isolated cobalt phthalocyanine （CoPc） molecule on an ultrathin layer of NaC1 have been investigated. High-resolution STM images give a detailed picture of the lowest unoccupied molecular orbital （LUMO） of an isolated CoPc. It is shown that the NaC1 ultrathin layer efficiently decouples the interaction of the molecules from the underneath metal substrate, which makes it an ideal substrate for studying the properties of single molecules. Moreover, strong dependence of the appearance of the molecules on the sample bias in the region of relatively high bias （〉 3.1 V） is ascribed to the image potential states （IPSs） of NaCI/Cu（100）, which may provide us with a possible method to fabricate quantum storage devices.
基金supported by the National Key R&D Program of China(No.2016YFA0200600)the National Natural Science Foundation of China(No.21790352,No.22174135)+1 种基金the Strategic Priority Research Program of Chinese Academy of Sciences(No.XDB36000000)Anhui Initiative in Quantum Information Technologies(No.AHY090100)。
文摘The quality of the scanning tip is crucial for tip-enhanced Raman spectroscopy(TERS)experiments towards large signal enhancement and high spatial resolution.In this work,we report a controllable fabrication method to prepare TERS-active tips by modifying the tip apex at the atomic scale,and propose two important criteria to in-situ judge the tip’s TERS activity for tip-enhanced Raman measurements.One criterion is based on the downshift of the first image potential state to monitor the coupling between the far-field incident laser and near-field plasmon;the other is based on the appearance of the low-wavenumber Raman peaks associated with an atomistic protrusion at the tip apex to judge the coupling efficiency of emissions from the near field to the far field.This work provides an effective method to quickly fabricate and judge TERS-active tips before real TERS experiments on target molecules and other materials,which is believed to be instrumental for the development of TERS and other tip-enhanced spectroscopic techniques.
基金Project supported by the National Natural Science Foundation of China (No.10472030).
文摘The problem of the elastic interaction between a screw dislocation and a three-phase circular inclusion with interracial rigid lines （anti-cracks） is investigated. An efficient and concise method for the complex multiply connected region is developed, with which explicit series form solutions of the complex potentials in the matrix, and the interphase layer and inclusion regions are derived. Based on the complex potentials, the image force on the screw dislocation is then calculated by using the Peach-Koehler formula. The equilibrium position of the dislocation is discussed in detail for various rigid line geometries, interphase layer thicknesses and material property combinations. The main results show that the interracial rigid lines exert a significant perturbation effect on the motion of the screw dislocation near the circular inclusion surrounded by an interphase layer.
基金supported by the National Instrumentation Programmme(Nos.2011YQ17006702 and 2011YQ14015010)the National Natural Science Foundation of China(Nos.81102413 and 21175121)Fundamental Research Program of Shenzhen (No.JC201005280634A).
文摘A new multivariate statistical strategy for analyzing large datasets that are produced by imaging mass spectrometry（IMS） techniques is reported.The strategy divides the whole datacube of the sample into several subsets and analyses them one by one to obtain the results.Instead of analyzing the whole datacube at one time,the strategy makes the analysis easier and decreases the computation time greatly.In this report,the IMS data are produced by the air flow-assisted ionization IMS（AFAI-IMS）.The strategy can be used in combination with most multivariate statistical analysis methods.In this paper,the strategy was combined with the principal component analysis（PCA） and partial least square analysis（PLS）.It was proven to be effective by analyzing the handwriting sample.By using the strategy,the m/z corresponding to the specific lipids in rat brain tissue were distinguished successfully.Moreover the analysis time grew linearly instead of exponentially as the size of sample increased.The strategy developed in this study has enormous potential for searching for the mjz of potential biomarkers quickly and effectively.
基金financial support from the National Key Basic Research Support Foundation of China(No. 2015CB856301)the National Natural Scientific Foundation of China (Nos. 21571007, 21271013,21321001)
文摘Targeted-delivery is of great importance to molecular probes and drugs for cell biology study. Herein we reported 11 sulfur-containing coumarins as cell imaging probes. Different sulfur speciation of the 4 representative coumarins SC1-SC4 renders them significantly different subcellular localizations and cellular uptake pathways： SC1 containing thioether group located in lysosomes, while sulfoxide and sulfone compounds SC2 and SC3 distributed in the whole cell. Furthermore, the cationic sulfonium containing compound SC4 was internalized by clathrin-mediated endocytosis and localized at mitochondria. By analyzing the molecular parameters of all 11 coumarins, we found that different sulfur speciation affected their lipophilicity and electrostatic surface potential. These two key factors play roles in altering biological behaviors of the coumarins. The results revealed the importance of sulfur speciation on the physicochemical properties and thus subcellular localization of bioprobes. This is useful for designing new functional bioprobes.
基金The Open Project of the State Key Laboratory of Robotics and System at Harbin Institute of Technologygrant number:SKLRS-2010-2D-09,SKLRS-2010-MS-10+5 种基金National Natural Science Foundation of Chinagrant number:61201096Natural Science Foundation of Changzhou Citygrant number:CJ20110023Changzhou High-tech Reasearch Key Laboratory Projectgrant number:CM20123006
文摘The combination of electroencephalogram (EEG) and functional magnetic resonance imaging(fMRI) is a very attractive aim in neuroscience in order to achieve both high temporal and spatial resolution for the non-invasive study of cognitive brain function. In this paper, we record simultaneous EEG-fMRI of the same subject in emotional processing experiment in order to explore the characteristics of different emotional picture processing, and try to find the difference of the subjects' brain hemisphere while viewing different valence emotional pictures. The late positive potential(LPP) is a reliable electrophysiological index of emotional perception in humans. According to the analysis results, the slow-wave LPP and visual cortical blood oxygen level-dependent (BOLD) signals are both modulated by the rated intensity of picture arousal. The amplitude of the LPP correlate significantly with BOLD intensity in visual cortex, amygdala, temporal area, prefrontal and central areas across picture contents.
基金the National Key R&D Program of China(2020YFA0211200,2021YFA1200403)the National Natural Science Foundation of China(22090050,22522402,22474131,U24A20502)+2 种基金Shenzhen Science and Technology Program(No.JCYJ20230807113706013)the Natural Science Foundation of Hubei Province(2024AFA001,2025AFA075)the Interdisciplinary Research Support Program at Huazhong University of Science and technology(2024JCYJ052).
文摘Unfolded proteins,as critical biomarkers in cancer,hold significant potential for tumor-specific imaging.However,the content of unfolded proteins within distinct subcellular organelles varies markedly and reflects divergent physiological implications.Currently,few fluorescent probes enable precise quantification and imaging of mitochondrial unfolded proteins.Herein,we report a fluorescent probe,MAP,for accurate imaging of mitochondrial unfolded proteins.MAP incorporates a triphenylphosphonium group that specifically targets mitochondria,with cellular uptake efficiency proportional to mitochondrial membranepotential.Within mitochondria,the maleimide moiety of MAP covalently reacts with thiol groups on unfolded proteins,restricting molecular rotation and suppressing intramolecular charge transfer(ICT),thereby triggering a significant fluorescence enhancement.Owing to the hyperpolarized mitochondrialmembrane potential and abundant mitochondrialunfolded proteins in SKOV3 cells,MAP with superior biocompatibilityachieves tumor-specific imaging with a high signal-to-noise ratio(9.5),enabling precise intraoperative navigation for ovarian cancer resection.This molecular design strategy provides a foundational framework for developing organelle-specific unfolded protein probes and advancing image-guided surgical applications.
