最新刊期
      卷 0 ， 期 0 ， 2020
      • DONG Yuanxing1,2 GAO Yuxi 1 CHEN Chunying1 LI Bai1 SUN Jin1 HE Wei1 HUANG Yuying1 CHAI Zhifang1 1
        Issue 9, (2006)
        摘要：The microsome of tumor tissues and their surrounding nontumor tissues of five HCC were prepared with a differential centrifugation procedure. The proteins in cytosol and microsome were separated with the thin layer isoelectric focusing (IEF). The contents of zinc (Zn), iron (Fe), copper (Cu), and manganese (Mn) in protein bands were measured using the synchrotron radiation X-ray fluorescence (SRXRF) analysis. At least 7 Mn-containing bands, 8 Fe-containing bands, 6 Cu-containing bands, and 8 Zn-containing bands in microsome were observed in tumor tissues and their surrounding nontumor tissues for the 5 individuals with HCC. The metal contents in protein bands of tumor tissues were generally similar to those of nontumor tissues, except for bands with pIs of 5.9 and 9.3. The Fe content in the band of 5.9 of tumor microsome was only 40% of that in nontumor, but the Cu and Zn contents are 2- and 3.5-fold higher, respectively, in the band of 9.3 compared to that of nontumor tissues. The results suggest that the metal distribution patterns of various metal-containing bands are distinguishable between the tumor and nontumor tissues. The difference of the metal distribution patterns may be related to the carcinogenesis of the liver tissues.  
        关键词：Synchrotron radiation X-ray fluorescence;Isoelectric focusing;Human hepatocellular carcinoma;Metal-containing proteins   
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        发布时间：2021-03-12
      • YAN Wensheng1 SUN Zhihu1 A.V. KOLOBOV2 WEI Shiqiang1 1
        Issue 9, (2006)
        摘要：The fluorescence extended X-ray absorption fine structure (EXAFS) technique was used to study the local structure of Ge nanocrystals embedded in SiO2 matrix, which were synthesized by the magnetron sputtering co-deposition. It is revealed that in the as-prepared samples, Ge atoms mainly exist in the form of amorphous phases of Ge and GeO2. The sample with Ge mole fraction of 25% is mainly composed of the GeO2 phase. Upon annealing at 1073 K, Ge nanocrystals are formed. In the sample of 25% Ge (mole fraction), Ge nanocrystals come from amorphous Ge phase; while in the sample of 60% Ge (mole fraction), Ge atoms come from both GeO2 and amorphous Ge phase. A further analysis of the sample containing 60% Ge (mole fraction) shows that about 20% GeO2 (mole fraction) is turned into Ge nanocrystals due to the reduction reaction with Si atoms coming from the substrate.  
        关键词：Extended x-ray absorption fine structure (EXAFS);Ge nanocrystal;Local structure   
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        发布时间：2021-03-12
      • FENG Guangyao PEI Yuanji JIANG Daoman HONG Yilin SHANG Lei ZHOU Yingui WANG Xiangqi SUN Baogen LIU Yuzhu
        Issue 9, (2006)
        摘要：The design of electron gun, which is one part of a linac for food irradicidation, is described. In order to get the optimum model, the electric field in the gun is calculated, and the process of beam emission is simulated considering the space charge effects. Parameters measured in debugging experiment show that the facility has satisfied the design targets. The effect of solenoid’s leakage field on the beam of the electron gun has also been discussed.  
        关键词：Food irradicidation;Electron gun;Linac;Space charge effect   
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        发布时间：2021-03-12
      • ZHANG Guohui CHEN Jinxiang TANG Guoyou
        Issue 9, (2006)
        摘要：By using a gridded ionization chamber, the differential cross sections and angle integrated cross sections of the 6Li(n, t)4He reaction were measured at neutron energies of 1.05, 1.54 and 2.25 MeV. Neutrons were produced through the T(p, n)3He reaction. The absolute neutron flux was determined through a relatively calibrated BF3 long counter and a 238U foil. Present results are compared with existing data, and the discrepancies for the cross sections of the 6Li(n, t)4He reaction in the 1―2 MeV energy range are clarified to some extent.  
          
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        发布时间：2021-03-12
      • LIU Shuhuan1,2 JIANG Xinbiao1 ZHONG Yunhong1 ZHANG Wenshou1 LIU Nannan1 WANG Wushang1 ZHOU Hui1 SHAO Beibei2 1
        Issue 9, (2006)
        摘要：The neutron spectra and flux of the fast neutron device in reactor are measured with multiple foil activa- tion method in the present paper, and the uncertainties of the measurement spectra is analyzed with Monte Carlo method. Thermoluminescent detector (TLD) is used to measure γ-ray dose rate of the device. The values of the ex- periment results prove that the indexes of the designed device are satisfied well.  
        关键词：Fast neutron device;Neutron spectra;Gamma dosimetry   
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        发布时间：2021-03-12
      • LI Aiwu1,2 YU Xuefeng1 REN Diyuan1 WANG Dong1,2 KUANG Zhibing1,2 LIU Gang1,2 1
        Issue 9, (2006)
        摘要：The statistical method has been applied to analyze the data of a large number samples of CMOS CC4069 circuits before and after irradiation. The standard deviation and statistical distribution of the threshold voltage of the transistors before and after irradiation were compared, and the distribution characteristics of the threshold voltage shift of the samples were studied. Furthermore, the necessity of selecting electronic devices, used in spaceflight systems to ensure their reliability, is discussed.  
        关键词：CMOS devices;Total dose irradiation;Threshold voltage;Statistics   
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        发布时间：2021-03-12
      • WEI Zengquan1 XIE Hongmei1 Yasuda N2 Fujitaka K2 MEI Mantong3 ZHUANG Chuxiong3 1
        Issue 9, (2006)
        摘要：In order to identify the space heavy ions hitting loaded-seeds, the solid-state nuclear track detector (SSNTD) CR-39 was used as a part of a “sandwich” detecting system. By means of measurements of ion range R and etched rate V of CR-39, a slope (dR/dV-1) was acquired. Based on a mathematical model R* = 0.015AZ3.13V-1 estab- lished by ourselves, the coefficients of the model were fitted by using data from the calibration experiments of known ions. The calibration experiments of CR-39 for C, Ne, Si, Ar and Fe ions were carried out at HIRFL-IMP in China, and HIMAC-NIRS in Japan. A fitted formula identifying ions Z3.13=3.75×104 +1.50(dR/dV-1) and a calibration line were obtained.  
        关键词：Space mutation breeding;Solid-state nuclear track detector CR-39;Identification;Calibration experi- ment   
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        发布时间：2021-03-12
      • LIU Bing1,2 ZHANG Hong1 LI Wenjian1 GAO Qingxiang3 MIN Fengling1,2 Xie Yi1,2 ZHOU Qingming1,2 DUAN Xin1,2 ZHOU Guangming1 1
        Issue 9, (2006)
        摘要：The effect of AdCMV-p53 gene transfection induced by γ-ray irradiation on human colorectal adenocarcinoma cells was investigated. The HT-29 cells were irradiated by 0.5, 1.0, 2.0 Gy 60Co γ-rays, then were transfected with AdCMV-GFP (a replication of deficient recombinant adenoviral vector containing a CMV promoter and green fluorescent protein) or AdCMV-p53 (a replication of deficient recombinant adenoviral vector containing a CMV promoter and carrying human wild p53 gene). Cytotoxity was measured by clonogenic survival assay; apoptosis and the p53 expression were determined by flow cytometry. The results show that the pre-exposure of 0.5 Gy 60Co γ-rays significantly enhanced the inhibition of HT-29 cells with AdCMV-p53 transfection and promoted cell apoptosis. The inhibition rates for the groups of pre-exposure with 0.5 Gy and transfection with 40 and 80 MOI AdCMV-p53 were 50% and 20% higher than those for the groups of the mere transfection, and 40% more than the mere irradiation group. In the case of higher than 0.5 Gy pre-exposure, no significant difference was found between the pre-exposure with transfection group and the mere irradiation group. So 0.5 Gy pre-irradiation and AdCMV-p53 transfection obviously increases the inhibition of HT-29 cells with AdCMV-p53 transfection. The optimum condition is the lower than 1.0 Gy pre-exposure combined with the lower than 80 MOI AdCMV-p53 transfection.  
        关键词：p53;Radiation;Adenovirus vector;Gene transfection;Colorectal adenocarcinoma   
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        发布时间：2021-03-12
      • WEI Wei1,3 LI Wenjian1 XIA Jingguang1,3 JIN Xiaodong1 GUO Chuanling1,3 SU Xu2 1
        Issue 9, (2006)
        摘要：In this paper, the effect of the ionizing radiation with different linear energy transfer on radiosensitivity, cell cycle alteration and the change of apoptosis in HepG2 hepatoma cell lines are studied to build up the base data for clinical therapy. Exponentially growing HepG2 cell lines are irradiated by 12C6+ ions and X-ray at the doses of 0, 0.5, 1, 2, 4and 8Gy, respectivity. The radiosensitivity is assessed by means of the colony-forming assay. The DNA content, percentage of each cell-cycle phase and the apoptosis rate are obtained with the flow cytometry methods. The results indicate that compared with X-ray,the survival fraction of HepG2 hepatoma cells irradiated by 12C6+ ions is evidently lower, the S phase arrest, G2/M phase arrest delay and the apoptosis in HepG2 cells irradiated by 12C6+ ions are more prominent with the increase of dose and repaired time, thus suggesting that 12C6+ ions can more effectively kill the HepG2 cells and induce apoptosis in the cells than X-ray.  
        关键词：Ionizing radiation;HepG2 cell line;Radiosensitivity;Cell cycle;Cell apoptosis   
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        发布时间：2021-03-12
      • LI Guiping1 WANG Yongxian2 1
        Issue 9, (2006)
        摘要：Magnetic nanoparticles barrier is a novel kind of drug delivery system for magnetic targeting drugs, which can effectively deliver the drug to a tumor target site and increase therapeutic benefit, with the side effects minimized. This article summarizes the most outstanding papers on the of magnetic nanoparticles used as the targeting drug’s delivery systems.  
        关键词：Magnetic nanoparticles;Drug delivery system;Magnetic targeting carriers   
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        发布时间：2021-03-12
      • TAO Yonghui1 ZHANG Lianfen1 YOU Xuyang2 WAN Weixing2 JIN Jian1 1
        Issue 9, (2006)
        摘要：The specificity of action of angiostatin on vascular endothelial cell is studied. 99Tcm-angiostatin was prepared by the SnCl2 reduced approach, then injected into the mice bearing S180 tumor or Matrigel via tail vein. The whole body distribution and the effect of 99Tcm-angiostatin in vivo were observed on the model of mice bearing S180 tumor and Matrigel by imaging and radioautography. The resultes indicate that the metabolism of 99Tcm-angiostatin is realized mainly by the liver and kidney pathway, and both S180 tumor and Matrigel can specifically uptake 99Tcm-angiostatin. The angiostatin’s role of inhibiting tumor is found on the basis of targeting novel vascular endothelial cell.  
        关键词：Angiostatin;Imaging;S180 tumor;Matrigel;99Tcm   
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        发布时间：2021-03-12
      • ZHANG Ying1 LIU Jianzhong1 LI Sijin1 FAN Yimin2 ZHANG Wei1 HU Guang1 1
        Issue 9, (2006)
        摘要：The objectives of this study are to estimate the utility of NOET in the diagnosis of intracranial occupying lesion and to compare the detectability of NOET and MIBI and the relationship with histopathology. 24 patients with untreated intracranial occupying lesion confirmed by CT and/or MRI were included in this study. 20 of them underwent MIBI imaging also. All patients were operated during 2 weeks after imaging. Statistical significance was observed for both agents in differentiating intracranial occupying lesions, but no statistical significance between them. These preliminary results indicate that NOET can go through blood brain barrier and be concentrated on malignant lesions, but it is few concentrated on benign lesions and the false positive cases are less than MIBI. So it may be a more suitable new tumor positive agent.  
        关键词：99Tcm-N-NOET;99Tcm-MIBI;Brain tumor;Radionuclide imaging   
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        发布时间：2021-03-12
      • REN Jiafu ZHOU Jianbin TUO Xianguo LIN Juan MU Keliang
        Issue 9, (2006)
        摘要：The EDXRF-1024 portable high-precision X-ray fluorescence analyzer adopts new electric refrigeration Si-PIN semiconductor detector and radioisotope sources. Without liquid nitrogen cooling the on-site measurement can be realized, and qualitative and quantitative analysis can be completed for 5—10 kinds of elements simultaneously. The detection limits range from 100 to 200 mg/kg, and the precision is 2%—10%.  
        关键词：X-Ray fluorescence spectrometer;On-site analysis;Radioisotope source   
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        发布时间：2021-03-12
      • LI Xiaofeng BAI Peng WU Jun WANG Chao LI Xingang
        Issue 9, (2006)
        摘要：The boron isotope abundance measured by the inductively coupled plasma mass spectrometry (ICP-MS) was corrected under the optimal instrument conditions using standard solution of the boron isotope standard reference NIST SRM 951, and both the correction factor and the linear concentration range were determined. Boron isotope abundance of (CH3)2O·BF3 complex was measured under the same instrument conditions when 10B isotope was concentrated, with the relative standard deviation of 1.095%. The instrument stability was checked. The method to measure the boron isotope abundance has a low “memory effect”. The results are reliable and have a high precision.  
        关键词：Inductively coupled plasma mass spectrometry;Isotope abundance;Boron isotope;Dimethyl ether-boron trifluoride complex   
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        发布时间：2021-03-12
      • LI Dongming1,2 HU Huasi1 CHU Jun1 1
        Issue 9, (2006)
        摘要：The paper aims at the study on the indoor radon concentration in high buildings. The two-filter method is chosen as the experimental method to detect radon concentrations by a FT-648 radon counter. The simple mass balance model is used to simulate the relationships among the indoor radon concentration, height, and ventilation rates. The results show a good agreement between the simulation calculation and the measurement data for the height of more than about 9 meters (third floor) in high buildings. This study indicates that the indoor radon concentration in high buildings is decided mainly by the radon emission of building materials and by ventilation rates.  
        关键词：Radon concentration;Two-filter method;High buildings   
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        发布时间：2021-03-12
      • ZHANG Shuocheng WANG Dan JING Lan QIAO Weimin MA Yunhai
        Issue 9, (2006)
        摘要：An automatic control variac system is designed in order to satisfy the controlling requirement of the elec- tronic accelerator developed by the Institute. Both design and operational principles, structure of the system as well as the software of industrial PC and micro controller unit are described. The interfaces of the control module are RS232 and RS485. A fiber optical interface (FOC) could be set up if an industrial FOC network is necessary, which will extend the filed of its application and make the communication of the system better. It is shown in practice that the system can adjust the variac output voltage automatically and assure the accurate and automatic control of the electronic accelerator. The system is designed in accordance with the general design principles and possesses the mer- its such as easy operation and maintenance, good expansibility, and low cost, thus it could also be used in other indus- trial branches.  
        关键词：Electronic accelerator;Variac;Industrial automatic control system;MSC1210 MCU;Fiber optics communication (FOC)   
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        发布时间：2021-03-12
      • WEI Zhiyong1 ZANG Lihui2 FAN Wo2 LI Ming2 1
        Issue 9, (2006)
        摘要：Applications of neutron scattering in the study of structures and functions of biological macromolecules are reviewed. Low energy neutrons can induce elastic, quasielastic and inelastic scatterings in biological samples. By measuring the scattered neutron intensity versus momenta and energy transfers, the structure and dynamical information of the biological macromolecules can be obtained. From the scattering intensity function ,form factor and structure factor, we can get information about the geometric size, shape, volume, mass, radius of gyration, distance distribution functions and concentration of the interest atoms especially hydrogen atoms, in the biological macromolecules. Moreover, compared with the X-ray method, neutron scattering causes less damage to biological samples.  
        关键词：Neutron scattering;Intensity function;Biological macromolecule   
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        发布时间：2021-03-12
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