The propagation of single-event effects(SEEs)on a Xilinx Zynq-7000 system on chip(SoC)was inves-tigated using heavy-ion microbeam radiation.The irradia-tion results reveal several functional blocks’sensitivity locati...The propagation of single-event effects(SEEs)on a Xilinx Zynq-7000 system on chip(SoC)was inves-tigated using heavy-ion microbeam radiation.The irradia-tion results reveal several functional blocks’sensitivity locations and cross sections,for instance,the arithmetic logic unit,register,D-cache,and peripheral,while irradi-ating the on-chip memory(OCM)region.Moreover,event tree analysis was executed based on the obtained microbeam irradiation results.This study quantitatively assesses the probabilities of SEE propagation from the OCM to other blocks in the SoC.展开更多
In this paper the single-event responses of the silicon germanium heterojunction bipolar transistors(SiGe HBTs) are investigated by TCAD simulations and laser microbeam experiment. A three-dimensional(3D) simulation m...In this paper the single-event responses of the silicon germanium heterojunction bipolar transistors(SiGe HBTs) are investigated by TCAD simulations and laser microbeam experiment. A three-dimensional(3D) simulation model is established, the single event effect(SEE) simulation is further carried out on the basis of Si Ge HBT devices, and then, together with the laser microbeam test, the charge collection behaviors are analyzed, including the single event transient(SET) induced transient terminal currents, and the sensitive area of SEE charge collection. The simulations and experimental results are discussed in detail and it is demonstrated that the nature of the current transient is controlled by the behaviors of the collector–substrate(C/S) junction and charge collection by sensitive electrodes, thereby giving out the sensitive area and electrode of SiGe HBT in SEE.展开更多
Energy instability strongly affects the state and the beam size of the single ion microbeam. A facility based on the Generating Voltmeter was developed to improve the energy stability of the CAS-LIBB （Chinese Academy...Energy instability strongly affects the state and the beam size of the single ion microbeam. A facility based on the Generating Voltmeter was developed to improve the energy stability of the CAS-LIBB （Chinese Academy of Sciences, key laboratory of ion beam bioengineering） single ion microbeam. This paper presents the analysis of the energy＇ instability of the single ion microbeam. A simplified theoretical model is set up to calculate the relationship between the energy instability and the beam spot size. By using this technique, the energy instability is adjusted to about 1%. Stable run-time is over 6 hours. The radius of the single ion beam is reduced by 10% compared to the previous olin.展开更多
Single ion microbeam is the most advanced technology which can emit a single ion for precise localization. A single-ion microbeam facility has been constructed at the Key Laboratory of Ion Beam Bioengineering （LIBB）...Single ion microbeam is the most advanced technology which can emit a single ion for precise localization. A single-ion microbeam facility has been constructed at the Key Laboratory of Ion Beam Bioengineering （LIBB）, Chinese Academy of Sciences （CAS）, with a spatial resolutions of about 5 μm. Based on CAS-LIBB microbeam, three key elements affecting the quality of the system are assessed： the size of beam spot, the energy range and the counting accuracy of implanting ions. Various contributions to the ion beam stability, including the ion source, the terminal voltage of electrostatic accelerator and the components in beam pipeline, are discussed. Analysis shows that the improvement of terminal voltage stability is the most important issue for future optimization of CAS-LIBB facility. Some preliminary investigations and project aimed at optimization and development are proposed as well.展开更多
High-energy proton microbeam facilities are powerful tools in space science,biology and cancer therapy studies.The primary limitations of the 50 MeV proton microbeam system are the poor beam quality provided by the cy...High-energy proton microbeam facilities are powerful tools in space science,biology and cancer therapy studies.The primary limitations of the 50 MeV proton microbeam system are the poor beam quality provided by the cyclotron and the problem of intense scattering in the slit position.Here,we present an optical design for a cyclotron-based 50 MeV high-energy proton microbeam system with a micron-sized resolution.The microbeam system,which has an Oxford triplet lens configuration,has relatively small spherical aberrations and is insensitive to changes in the beam divergence angle and momentum spread.In addition,the energy filtration included in the system can reduce the beam momentum spread from 1 to 0.02%.The effects of lens parasitic aberrations and the lens fringe field on the beam spot resolution are also discussed.In addition,owing to the severe scattering of 50 MeV protons in slit materials,a slit system model based on the Geant4 toolkit enables the quantitative analysis of scattered protons and secondary particles.For the slit system settings under a 10-micron final beam spot,very few scattered protons can enter the quadrupole lens system and affect the focusing performance of the microbeam system,but the secondary radiation of neutrons and gamma rays generated at the collimation system should be considered for the 50 MeV proton microbeam.These data demonstrate that a 50 MeV proton microbeam system with a micron-sized beam spot based on a cyclotron is feasible.展开更多
This study addresses long-time behavior for a thermoelastic microbeam problem with time delay and the Coleman-Gurtin thermal law,the convolution kernel of which entails an extremely weak dissipation in the thermal law...This study addresses long-time behavior for a thermoelastic microbeam problem with time delay and the Coleman-Gurtin thermal law,the convolution kernel of which entails an extremely weak dissipation in the thermal law.By using the semigroup theory,we first establish the existence of global weak and strong solutions as well as their continuous dependence on the initial data in appropriate function spaces,under suitable assumptions on the weight of time delay term,the external force term and the nonlinear term.We then prove that the system is quasi-stable and has a gradient on bounded variant sets,and obtain the existence of a global attractor whose fractal dimension is finite.A result on the exponential attractor of the system is also proved.展开更多
Silicon-germanium （SiGe） hereto-junction bipolar transistor current transients induced by pulse laser and heavy iron are measured using a real-time digital oscilloscope. These transients induced by pulse laser and h...Silicon-germanium （SiGe） hereto-junction bipolar transistor current transients induced by pulse laser and heavy iron are measured using a real-time digital oscilloscope. These transients induced by pulse laser and heavy iron exhibit the same waveform and charge collection time except for the amplitude of peak current. Different laser energies and voltage biases under heavy ion irradiation also have impact on current transient, whereas the waveform remains unchanged. The position-correlated current transients suggest that the nature of the current transient is controlled by the behavior of the C/S junction.展开更多
Particle induced X- ray emission (PIXE) and Rutherford backscattering spectrometry (RBS) have been used extensively for analytical purpose because of their quantitative accuracy, reliability, simplicity and capability...Particle induced X- ray emission (PIXE) and Rutherford backscattering spectrometry (RBS) have been used extensively for analytical purpose because of their quantitative accuracy, reliability, simplicity and capability of non- destructive and multielement analysis. When these techniques are combined with a scanning microbeam system and a data acquisition system, three dimensional distribution of elemental composition can be displayed. Samples analyzed so far at Fudan University include a microelectronic circuit and some biological and archaeological samples. The PIXE and RBS spectra and the secondary electron images have been measured.展开更多
Single-particle microbeam is uniquely capable of precisely delivering a preset number of charged particles to individual cells or sub-cellular targets to be determined in vitro, It is crucial to find a reference point...Single-particle microbeam is uniquely capable of precisely delivering a preset number of charged particles to individual cells or sub-cellular targets to be determined in vitro, It is crucial to find a reference point that relates the microbeam＇s location to the microscope＇s plane, and align individual targets at this reference point for cell irradiation. To choose an appropriate reference point, an approach based on analysing the intensity distribution of fluorescence in a thin scintillator excited by traversing particles is newly developed using the CAS-LIBB single-particle microbeam, which features decisive physical signification and sufficient resolution. As its bonus, this on-line analysis provides precise and fast response to the determination of beam profile and potentially optimizes the microbeam quality by further adjusting hardware setup.展开更多
A single-particle microbeam facility has been constructed at the Key Laboratory of Ion Beam Bioengineering (LIBB), Chinese Academy of Sciences (CAS). At the CAS-LIBB microbeam facility, we have developed protocols to ...A single-particle microbeam facility has been constructed at the Key Laboratory of Ion Beam Bioengineering (LIBB), Chinese Academy of Sciences (CAS). At the CAS-LIBB microbeam facility, we have developed protocols to place exact numbers of charged particles through nuclear centroids of cells, at defined positions in the cytoplasm relative to the nucleus, and through defined fractions of cells in a population. In this paper, we address the methods for nucleus, cytoplasm and bystander (either a single or an exact number of ions is delivered to a certain percentage of cells in a population to study the bystander effects of radiation) irradiation in detail from the precision of target finding and cell locating in the image analysis system. Moreover, for cells touching slightly in an image, a watershed method is used to separate these touching objects; after that, the number of objects in an image is counted accurately and the irradiation points are located precisely.展开更多
The Experiments, methods and results of obtaining micron beam in the Microbeam Facility of the Institute of Plasma Physics were discussed in this paper. The H+2 beam was accelerated by the Van de GraafF electrostatic ...The Experiments, methods and results of obtaining micron beam in the Microbeam Facility of the Institute of Plasma Physics were discussed in this paper. The H+2 beam was accelerated by the Van de GraafF electrostatic accelerator, and the collimator at the end of the beam line is a 60 μm thick stainless steel chip. And as a result, particle tracks on the solid track probes (CR39 film) etched in the solution of NaOH showed that the beam can go through the collimator with a small aperure (2000, 300, 55, 30, or 10 μm) and 3.5 μm thick vacuum film (Mylar). Besides the CR39 method, the beam was measured by an energy spectrum detector after the 10 μm diameter aperture and the 3.5 μm thick vacuum film too.展开更多
The progress of a microbeam facility in the Institute of Plasma Physics was discussed in this paper. This kind of equipment can supply single-particle beam which may be implanted into cells in micrometer-radius and me...The progress of a microbeam facility in the Institute of Plasma Physics was discussed in this paper. This kind of equipment can supply single-particle beam which may be implanted into cells in micrometer-radius and measured by a new outstanding detector among global microbeam systems. Measurements by some plain targets showed that the highest current after the accelerator tube can be larger than 20 /μA, the H_2^+ current before the second bending magnet is near 0.9 /μA, the current after the second bending magnet is near 0.8 μA, and the current of the beam line (after a 2-mm diameter aperture) is near 0.25 nA which is enough for the single-particle microbeam experiment. It took scientists 3 months to do their microbeam experiment after setting up the accelerator beam line and get the microbeam from this equipment. Two pre-collimators were installed between the 2-mm diameter aperture and the collimator to survey the beam. Tracks on the CR39 film etched in the solution of NaOH showed that the beam can go through the collimator including a 10 μm diameter aperture and the 3.5 μm thick vacuum sealing film (Mylar). A new method, which is called optimization of the beam quality, was put forward in this paper, in order to get smaller diameter of beam-spot in microbeam system.展开更多
In this paper, two automatically calculated thresholds based on a statistical analysis of the histogram were used to apply binary segmentation to the bitmap. When the CCD and the microscope have been properly configur...In this paper, two automatically calculated thresholds based on a statistical analysis of the histogram were used to apply binary segmentation to the bitmap. When the CCD and the microscope have been properly configured and the raw image is preprocessed, the Otsu＇s method can meet the need of the control program on the whole.展开更多
Single particle microbeam （SPM） is uniquely capable of delivering precisely the predefined number of charged particles to determined individual cells or sub-cellular targets in situ. It has been recognized as a powe...Single particle microbeam （SPM） is uniquely capable of delivering precisely the predefined number of charged particles to determined individual cells or sub-cellular targets in situ. It has been recognized as a powerful technique for unveiling ionization irradiation mechanisms of organism. This article describes some investigations on the irradiation quality of SPM of major world laboratories by means of Monte Carlo method based on dosimetry and microdosimetry. Those parameters are helpful not only to improve SPM irradiating cell experiments but also to study the biological effects of cells irradiated by SPM.展开更多
A conception of the single-neutron microbeam facility was put forward in this paper. The specific particle (e.g. H+, 2d+ or a ) bombarding a specific target can generate neutron, when the particle energy is more than ...A conception of the single-neutron microbeam facility was put forward in this paper. The specific particle (e.g. H+, 2d+ or a ) bombarding a specific target can generate neutron, when the particle energy is more than a threshold (e.g., H+ energy is more than 2 MeV). And if the specific beam spot on the target is very small, the neutron beam along the direction of the specific beam spot will be very small too. If the neutron beam is weak and a neutron detector is mounted after the specific neutron collimator, the single- neutron will be obtained. Therefore, if the specific target and the neutron detector are installed after the proton accelerator and the microbeam system, the single-neutron microbeam will probably be obtained.展开更多
Single-particle microbeam as a powerful tool can open a research field to find answers to many enigmas in radiobiology. A single-particle microbeam facility has been constructed at the Key Laboratory of Ion Beam Bioen...Single-particle microbeam as a powerful tool can open a research field to find answers to many enigmas in radiobiology. A single-particle microbeam facility has been constructed at the Key Laboratory of Ion Beam Bioengineering （LIBB）, Chinese Academy of Sciences （CAS）, China. However there has been less research activities in this field concerning the original process of the interaction between low-energy ions and complicated organisms. To address this challenge, an in situ multi-dimensional quantitative fluorescence microscopy system combined with the CAS-LIBB single-particle microbeam II endstation is proposed. In this article, the rationale, logistics and development of many aspects of the proposed system are discussed.展开更多
The proposed multi-dimensional quantitative fluorescence microscopy for the CASLIBB single-particle microbeam II endstation is a CCD-based imaging system. We systematically analyse the theoretical and the practical co...The proposed multi-dimensional quantitative fluorescence microscopy for the CASLIBB single-particle microbeam II endstation is a CCD-based imaging system. We systematically analyse the theoretical and the practical considerations pertinent to choosing the right CCD camera and unveiling the principles underlying multifarious parameters. Therefore, this analysis can be a valuable tool in scrutinizing each parameter and clarifying proper usage of a scientific CCD camera.展开更多
Cellular micro-irradiation is now recognized as a powerful technique to unveil the mechanisms of interaction between ionizing radiation and living cells or tissues. The single-ion microbeam （SIM） is uniquely capable...Cellular micro-irradiation is now recognized as a powerful technique to unveil the mechanisms of interaction between ionizing radiation and living cells or tissues. The single-ion microbeam （SIM） is uniquely capable of delivering precisely the predefined number of charged particles （precise doses of radiation） to specific individual cells or sub-cellular targets in situ. No active research in the field concerning the original process of the interaction between low-energy ions and complicated organisms has been reported yet. To address this challenge, the aim of the present design is to further wrestle with multi-dimensional quantitative information from living cells traversed by an exact number of ions real-time rather than endpoints, in the time scale from milliseconds to days.展开更多
Single-Ion Microbeam (SIM) is uniquely capable of precisely delivering a predefined number of charged particles (precise doses of radiation) to individual cells or sub-cellular targets in situ. Since the early 1990...Single-Ion Microbeam (SIM) is uniquely capable of precisely delivering a predefined number of charged particles (precise doses of radiation) to individual cells or sub-cellular targets in situ. Since the early 1990's, there has been an ever-increasing interest in developing and applying the SIM technique to problems in radiobiology for studies of cell and tissue damaged by ionizing radiations. Potential applications for SIM in radiobiology continues to grow and have been diversified. There are currently more than 14 SIM facilities worldwide, and they have been in a constant state of evolution. This paper reviews the current state of SIM research worldwide and the related pivotal technological developments in the fields of both biophysics and radiobiology. Representative applications and the perspective of SIM are also introduced and discussed.展开更多
基金This work was supported by the National Natural Science Foundation of China(Nos.11575138,11835006,11690040,11690043,and 11705216)the Innovation Center of Radiation Application(No.KFZC2019050321)the China Scholarships Council program(No.201906280343).
文摘The propagation of single-event effects(SEEs)on a Xilinx Zynq-7000 system on chip(SoC)was inves-tigated using heavy-ion microbeam radiation.The irradia-tion results reveal several functional blocks’sensitivity locations and cross sections,for instance,the arithmetic logic unit,register,D-cache,and peripheral,while irradi-ating the on-chip memory(OCM)region.Moreover,event tree analysis was executed based on the obtained microbeam irradiation results.This study quantitatively assesses the probabilities of SEE propagation from the OCM to other blocks in the SoC.
基金supported by the National Natural Science Foundation of China(Grant No.61274106)
文摘In this paper the single-event responses of the silicon germanium heterojunction bipolar transistors(SiGe HBTs) are investigated by TCAD simulations and laser microbeam experiment. A three-dimensional(3D) simulation model is established, the single event effect(SEE) simulation is further carried out on the basis of Si Ge HBT devices, and then, together with the laser microbeam test, the charge collection behaviors are analyzed, including the single event transient(SET) induced transient terminal currents, and the sensitive area of SEE charge collection. The simulations and experimental results are discussed in detail and it is demonstrated that the nature of the current transient is controlled by the behaviors of the collector–substrate(C/S) junction and charge collection by sensitive electrodes, thereby giving out the sensitive area and electrode of SiGe HBT in SEE.
文摘Energy instability strongly affects the state and the beam size of the single ion microbeam. A facility based on the Generating Voltmeter was developed to improve the energy stability of the CAS-LIBB （Chinese Academy of Sciences, key laboratory of ion beam bioengineering） single ion microbeam. This paper presents the analysis of the energy＇ instability of the single ion microbeam. A simplified theoretical model is set up to calculate the relationship between the energy instability and the beam spot size. By using this technique, the energy instability is adjusted to about 1%. Stable run-time is over 6 hours. The radius of the single ion beam is reduced by 10% compared to the previous olin.
基金the Innovation Grant of Chinese Academy of Sciences(No.KSCX2-SW-324)
文摘Single ion microbeam is the most advanced technology which can emit a single ion for precise localization. A single-ion microbeam facility has been constructed at the Key Laboratory of Ion Beam Bioengineering （LIBB）, Chinese Academy of Sciences （CAS）, with a spatial resolutions of about 5 μm. Based on CAS-LIBB microbeam, three key elements affecting the quality of the system are assessed： the size of beam spot, the energy range and the counting accuracy of implanting ions. Various contributions to the ion beam stability, including the ion source, the terminal voltage of electrostatic accelerator and the components in beam pipeline, are discussed. Analysis shows that the improvement of terminal voltage stability is the most important issue for future optimization of CAS-LIBB facility. Some preliminary investigations and project aimed at optimization and development are proposed as well.
基金supported by the National Natural Science Foundation of China(Nos.1197283,U1632271)the National Key R&D Program of China(No.2021YFA1601400).
文摘High-energy proton microbeam facilities are powerful tools in space science,biology and cancer therapy studies.The primary limitations of the 50 MeV proton microbeam system are the poor beam quality provided by the cyclotron and the problem of intense scattering in the slit position.Here,we present an optical design for a cyclotron-based 50 MeV high-energy proton microbeam system with a micron-sized resolution.The microbeam system,which has an Oxford triplet lens configuration,has relatively small spherical aberrations and is insensitive to changes in the beam divergence angle and momentum spread.In addition,the energy filtration included in the system can reduce the beam momentum spread from 1 to 0.02%.The effects of lens parasitic aberrations and the lens fringe field on the beam spot resolution are also discussed.In addition,owing to the severe scattering of 50 MeV protons in slit materials,a slit system model based on the Geant4 toolkit enables the quantitative analysis of scattered protons and secondary particles.For the slit system settings under a 10-micron final beam spot,very few scattered protons can enter the quadrupole lens system and affect the focusing performance of the microbeam system,but the secondary radiation of neutrons and gamma rays generated at the collimation system should be considered for the 50 MeV proton microbeam.These data demonstrate that a 50 MeV proton microbeam system with a micron-sized beam spot based on a cyclotron is feasible.
基金supported by the National Natural Science Foundation of China (11771216 and 11901306)the Key Research and Development Program of Jiangsu Province (Social Development)(BE2019725)the Natural Science Foundation of Jiangsu Province (SBK2017043142)
文摘This study addresses long-time behavior for a thermoelastic microbeam problem with time delay and the Coleman-Gurtin thermal law,the convolution kernel of which entails an extremely weak dissipation in the thermal law.By using the semigroup theory,we first establish the existence of global weak and strong solutions as well as their continuous dependence on the initial data in appropriate function spaces,under suitable assumptions on the weight of time delay term,the external force term and the nonlinear term.We then prove that the system is quasi-stable and has a gradient on bounded variant sets,and obtain the existence of a global attractor whose fractal dimension is finite.A result on the exponential attractor of the system is also proved.
基金Supported by the National Natural Science Foundation of China under Grant Nos 61274106 and 61574171
文摘Silicon-germanium （SiGe） hereto-junction bipolar transistor current transients induced by pulse laser and heavy iron are measured using a real-time digital oscilloscope. These transients induced by pulse laser and heavy iron exhibit the same waveform and charge collection time except for the amplitude of peak current. Different laser energies and voltage biases under heavy ion irradiation also have impact on current transient, whereas the waveform remains unchanged. The position-correlated current transients suggest that the nature of the current transient is controlled by the behavior of the C/S junction.
文摘Particle induced X- ray emission (PIXE) and Rutherford backscattering spectrometry (RBS) have been used extensively for analytical purpose because of their quantitative accuracy, reliability, simplicity and capability of non- destructive and multielement analysis. When these techniques are combined with a scanning microbeam system and a data acquisition system, three dimensional distribution of elemental composition can be displayed. Samples analyzed so far at Fudan University include a microelectronic circuit and some biological and archaeological samples. The PIXE and RBS spectra and the secondary electron images have been measured.
文摘Single-particle microbeam is uniquely capable of precisely delivering a preset number of charged particles to individual cells or sub-cellular targets to be determined in vitro, It is crucial to find a reference point that relates the microbeam＇s location to the microscope＇s plane, and align individual targets at this reference point for cell irradiation. To choose an appropriate reference point, an approach based on analysing the intensity distribution of fluorescence in a thin scintillator excited by traversing particles is newly developed using the CAS-LIBB single-particle microbeam, which features decisive physical signification and sufficient resolution. As its bonus, this on-line analysis provides precise and fast response to the determination of beam profile and potentially optimizes the microbeam quality by further adjusting hardware setup.
基金The project supported by the National Major Technologies R&D Program of China for the 10th Five-Year Plan Period (No.2001BA302B)the magnitude instrument development project of the Chinese Academy of Sciences, the National Natural Science Foundation of China (No. 19875054)the National Science Fund for Distinguished Young Scholars (No. 10225526)
文摘A single-particle microbeam facility has been constructed at the Key Laboratory of Ion Beam Bioengineering (LIBB), Chinese Academy of Sciences (CAS). At the CAS-LIBB microbeam facility, we have developed protocols to place exact numbers of charged particles through nuclear centroids of cells, at defined positions in the cytoplasm relative to the nucleus, and through defined fractions of cells in a population. In this paper, we address the methods for nucleus, cytoplasm and bystander (either a single or an exact number of ions is delivered to a certain percentage of cells in a population to study the bystander effects of radiation) irradiation in detail from the precision of target finding and cell locating in the image analysis system. Moreover, for cells touching slightly in an image, a watershed method is used to separate these touching objects; after that, the number of objects in an image is counted accurately and the irradiation points are located precisely.
基金The project supported by the National Science Foundation of in Anhui Province,China(No.01046201)
文摘The Experiments, methods and results of obtaining micron beam in the Microbeam Facility of the Institute of Plasma Physics were discussed in this paper. The H+2 beam was accelerated by the Van de GraafF electrostatic accelerator, and the collimator at the end of the beam line is a 60 μm thick stainless steel chip. And as a result, particle tracks on the solid track probes (CR39 film) etched in the solution of NaOH showed that the beam can go through the collimator with a small aperure (2000, 300, 55, 30, or 10 μm) and 3.5 μm thick vacuum film (Mylar). Besides the CR39 method, the beam was measured by an energy spectrum detector after the 10 μm diameter aperture and the 3.5 μm thick vacuum film too.
基金The project supported by the Natural Science Foundation Committee in Anhui Province, China (No. 01046201)
文摘The progress of a microbeam facility in the Institute of Plasma Physics was discussed in this paper. This kind of equipment can supply single-particle beam which may be implanted into cells in micrometer-radius and measured by a new outstanding detector among global microbeam systems. Measurements by some plain targets showed that the highest current after the accelerator tube can be larger than 20 /μA, the H_2^+ current before the second bending magnet is near 0.9 /μA, the current after the second bending magnet is near 0.8 μA, and the current of the beam line (after a 2-mm diameter aperture) is near 0.25 nA which is enough for the single-particle microbeam experiment. It took scientists 3 months to do their microbeam experiment after setting up the accelerator beam line and get the microbeam from this equipment. Two pre-collimators were installed between the 2-mm diameter aperture and the collimator to survey the beam. Tracks on the CR39 film etched in the solution of NaOH showed that the beam can go through the collimator including a 10 μm diameter aperture and the 3.5 μm thick vacuum sealing film (Mylar). A new method, which is called optimization of the beam quality, was put forward in this paper, in order to get smaller diameter of beam-spot in microbeam system.
文摘In this paper, two automatically calculated thresholds based on a statistical analysis of the histogram were used to apply binary segmentation to the bitmap. When the CCD and the microscope have been properly configured and the raw image is preprocessed, the Otsu＇s method can meet the need of the control program on the whole.
基金the National Science Foundation for Distinguished Young Scholars of China(No.10225526)the Knowledge Innovation Program of the Chinese Academy Sciences(No.KSCX2-SW-324)the Foundation for University Key Teachers by the Ministry of Education of China(No.2005jq1135)
文摘Single particle microbeam （SPM） is uniquely capable of delivering precisely the predefined number of charged particles to determined individual cells or sub-cellular targets in situ. It has been recognized as a powerful technique for unveiling ionization irradiation mechanisms of organism. This article describes some investigations on the irradiation quality of SPM of major world laboratories by means of Monte Carlo method based on dosimetry and microdosimetry. Those parameters are helpful not only to improve SPM irradiating cell experiments but also to study the biological effects of cells irradiated by SPM.
基金The project supported by the Nature Science Foundation Committee of Anhui Province (No. 01046201)
文摘A conception of the single-neutron microbeam facility was put forward in this paper. The specific particle (e.g. H+, 2d+ or a ) bombarding a specific target can generate neutron, when the particle energy is more than a threshold (e.g., H+ energy is more than 2 MeV). And if the specific beam spot on the target is very small, the neutron beam along the direction of the specific beam spot will be very small too. If the neutron beam is weak and a neutron detector is mounted after the specific neutron collimator, the single- neutron will be obtained. Therefore, if the specific target and the neutron detector are installed after the proton accelerator and the microbeam system, the single-neutron microbeam will probably be obtained.
文摘Single-particle microbeam as a powerful tool can open a research field to find answers to many enigmas in radiobiology. A single-particle microbeam facility has been constructed at the Key Laboratory of Ion Beam Bioengineering （LIBB）, Chinese Academy of Sciences （CAS）, China. However there has been less research activities in this field concerning the original process of the interaction between low-energy ions and complicated organisms. To address this challenge, an in situ multi-dimensional quantitative fluorescence microscopy system combined with the CAS-LIBB single-particle microbeam II endstation is proposed. In this article, the rationale, logistics and development of many aspects of the proposed system are discussed.
基金supported by the the National Major Technologies R&D Programme of China during the 10th Five-Year Plan Period(No.2001BA302B)the National Science Foundation for Distinguished Young Scholars(No.10225526)+1 种基金the Knowledge Innovation Programme of the Chinese Academy of Sciences(No.KSCX2-SW-324)the Foundation for University Key Teacher by the Ministry of Education(No.2005jq1135).
文摘The proposed multi-dimensional quantitative fluorescence microscopy for the CASLIBB single-particle microbeam II endstation is a CCD-based imaging system. We systematically analyse the theoretical and the practical considerations pertinent to choosing the right CCD camera and unveiling the principles underlying multifarious parameters. Therefore, this analysis can be a valuable tool in scrutinizing each parameter and clarifying proper usage of a scientific CCD camera.
基金the National Major Technologies R&D Program of China during the 10tb Five-Year Plan Period(No.2001BA30213)the National Science Fund for Distinguished Young Scholars(No.10225526)+1 种基金the Knowledge Innovation Program of the Chinese Academy of Sciences(No.KSCX2-SW-324)the Foundation for Key University Teachers by the Ministry of Education(No.2005jq1135)
文摘Cellular micro-irradiation is now recognized as a powerful technique to unveil the mechanisms of interaction between ionizing radiation and living cells or tissues. The single-ion microbeam （SIM） is uniquely capable of delivering precisely the predefined number of charged particles （precise doses of radiation） to specific individual cells or sub-cellular targets in situ. No active research in the field concerning the original process of the interaction between low-energy ions and complicated organisms has been reported yet. To address this challenge, the aim of the present design is to further wrestle with multi-dimensional quantitative information from living cells traversed by an exact number of ions real-time rather than endpoints, in the time scale from milliseconds to days.
基金The project supported by the National Major Technologies R & D Program of China during the 10th Five-Year Plan Period (No.2001BA302B)and the National Science Fund for Distinguished Young Scholars (No. 10225526)
文摘Single-Ion Microbeam (SIM) is uniquely capable of precisely delivering a predefined number of charged particles (precise doses of radiation) to individual cells or sub-cellular targets in situ. Since the early 1990's, there has been an ever-increasing interest in developing and applying the SIM technique to problems in radiobiology for studies of cell and tissue damaged by ionizing radiations. Potential applications for SIM in radiobiology continues to grow and have been diversified. There are currently more than 14 SIM facilities worldwide, and they have been in a constant state of evolution. This paper reviews the current state of SIM research worldwide and the related pivotal technological developments in the fields of both biophysics and radiobiology. Representative applications and the perspective of SIM are also introduced and discussed.
