γ-射线辐照对淋巴细胞杀伤效果的研究

目的 确定抑制淋巴细胞增殖所需的最低辐照剂量。方法 分别用 5、15、2 5、35、5 0Gy 5种剂量对血液进行辐照处理 ,然后进行混合淋巴细胞培养 (MLC)及有丝分裂原刺激试验 ,测定3 H掺入量以测定淋巴细胞的残存增殖活性。结果 与未辐照血相比 ,15Gy剂量辐照时 ,对MLC培养的抑制率已达 (96 .4± 2 .0 ) % ,但对PHA刺激和ConA刺激反应的抑制率分别为 (85 .0± 1.7) %和 (86 .5± 5 .1) % ,均低于 95 % ;2 5Gy剂量辐照时 ,对PHA刺激和ConA刺激反应的抑制率分别达 (96 .3± 2 .8) %和 (96 .6± 4 .3) %。结果 15Gy剂量不足以预防TA GVHD ,最低辐照剂量应为 2 5Gy。

莪术油对鼻咽癌CNE-2细胞的凋亡及放疗增敏机制的影响

目的探讨莪术油、莪术油联合γ-射线照射对鼻咽低分化鳞癌细胞株CNE-2的增殖抑制和诱导凋亡作用;分析莪术油是否具有放疗增敏的作用,并研究其机制。方法体外培养CNE-2细胞,莪术油以体外直接加药的方式作用于CNE-2细胞,采用MTT、流式细胞术、电镜等分子生物学手段,检测莪术油单用或联合γ-射线对CNE-2的诱导凋亡作用、放疗增敏作用。结果莪术油单独使用,对CNE-2细胞有确切的增殖抑制及诱导凋亡作用,并与常规化疗药物5-Fu有相近的抑制作用(P>0.05)。莪术油的药物抑制作用呈现浓度依赖性,最低起效浓度为10μg/ml,最佳作用时间为48小时;5μg/ml、100μg/ml、300μg/ml的莪术油联合100cGy的γ-射线作用2天后凋亡率由0.5%、2.15%、10.2%显著提高到8.6%、14%和26%,细胞的死亡率均在5%以下有明显的协同增效作用(P<0.01);联合作用96h后试验组的细胞主要以死亡为主,凋亡较少;500μg/ml的莪术油主要导致细胞死亡,有明显的细胞毒性。流式细胞仪结果显示较高浓度时,莪术油使CNE-2细胞阻滞在G1期。电子显微镜观察细胞凋亡的超微结构可以看到凋亡小体。结论莪术油可以抑制鼻咽癌细胞CNE-2的增殖并诱导其凋亡;莪术油和100cGy的γ-射线联合作用有明显的增敏作用;其作用机制与诱导肿瘤细胞发生凋亡及影响细胞生长周期有关。

Study on γ-Ray Irradiation Mutation of Bacillus subtilis NCD-2

[Objective] To study the effect of 60Co γ-rays irradiation on Botrytis cinerea biocontrol strains—Bacillus subtilis NCD-2. [Method] NCD-2 cells were irradiated at different doses of γ-rays from 100 to 2 000 Gy. The strains were screened by plate confrontation method and Oxford cup diffusion. [Result] The curves of the relationship of irradiation dose and mutation and lethal rate were obtained. The results showed that lethal rate increased with the increasing of irradiation dose. The lethal rate of 1 000 Gy irradiation dose reached 99.50%. The mutation rate increased below 500 Gy and decreased above 500 Gy. The highest mutation rate occurred when the irradiation dose was between 400 and 700 Gy, and the average mutation rate was above 15%. The optimal irradiation dose was 500 Gy, when the average mutation rate was 26.51% and lethal rate was 77.71%. [Conclusion] This study provided references for γ-rays irradiation mutation of Bacillus subtilis.

Effects on Agronomic Traits of M_1 by Pollen of Upland Cotton Irradiated by ^(60)Co-γ Ray

[Objective] The aim was to provide reference for research on radiation and breeding of cotton pollen through irradiating common ripe pollen grain of upland cotton by 60Co-γ Ray of varied doses. [Method] Ripe pollen grains of upland cotton were irradiated by 60Co-γ Ray with doses of 5, 10, 15, and 20 Gy, respectively, to learn radiation effect and select appropriate dose. [Result] Most properties of M1 obviously showed variation when dose was over 10 Gy; vitality, growth, and fertility were greatly inhibited when dose was 15 Gy which was almost semi-lethal concentration, and variation species were richest at the same time, which provided materi- als for practical breeding. [Conclusion] 60Co-γ Ray of 15 Gy is more suitable for mutagenesis research on ripe pollen grains of upland cotton.

Investigation on the Appropriate Dose of ^(60)Co-γ Irradiation for Tubers of Purple Sweet Potato

[Objective] This study aimed to investigate the appropriate dose of 60^Co-γ irradiation for tubers of purple sweet potato.[Methods] The tubers of two purple sweet potato varieties Xuzi L-7 and Yuenanzi were used as experimental materials,and treated with 60^Co-γ irradiation at different doses（0,25,50,75,100,125 and 150 Gy） to determine the emergence rate,number of emerged seedlings per tuber and fresh weight per seedling.[Results] After the 60^Co-γ irradiation at different doses,the emergence period of tubers was postponed while the emergence rate,number of emerged seedlings per tuber and fresh weight per plant were decreased,and the differences between different varieties and different irradiation doses reached significance level.Compared with the control,the emergence period of tubers at irradiation doses above 25 Gy were postponed by 2,3,5,6 and 12 d,respectively.[Conclusion] The half lethal dose（LD50） of Xuzi L-7 was 66.73 Gy,and that of Yuenanzi was 74.96 Gy.

Mutagenic Effect of ^(60)Co γ-rays Irradiation on Turf Characteristics of Buchloe dactyloides (Nutt.) Engelm.

[Objective] This study aimed to investigate the mutagenic effect of 60 Co γ-rays irradiation on turf characteristics of Buchloe dactyloides （Nutt.） Engelm. [Method] Buffalo grass were irradiated with 60 Co γ-rays at five different radiation intensities （1 200, 1 400, 1 600, 1 800, 2 000 Gy） to determine the related turf characteristics and analyze the mutagenic effect of 60 Co γ-rays at different radiation intensities on buffalo grass. [Result] Germination rates of buffalo grass irradiated by different radiation intensities of 60 Co γ-rays varied inconsistently, and the root length and bud length were shorter than the control; compared with the control, the height of irradiated seedlings was significantly reduced, and the number of tillers, plant height, leaf length and leaf blade width were smaller than the control; however, the stolon length, stolon diameter and number of stolon nods had no significant difference compared with the control. [Conclusion] This study laid foundation for determining the appropriate radiation intensity of 60 Co γ-rays and selecting useful mutants of buffalo grass.

γ-Ray Irradiation-Derived MnO/rGO Composites for High Performance Lithium Ion Batteries

We report a γ-ray irradiation reduction method to prepare MnO/reduced graphene oxide （rCO） nanocomposite for the anode of lithium ion batteries. γ-Ray irradiation provides a clean way to generate homogeneously dispersed MnO nanoparticles with finely tuned size on rGO surface without the use of surfactant. The MnO/rGO composite enables a fully charge/discharge in 2 min to gain a reversible specific capacity of 546 （mA-h）/g which is 45 higher than the theoretical value of commercial graphite anode.

Immunologic changes to autologous transfusion after operational trauma in malignant tumor patients:Neopterin and Interleukin-2

Objective:To estimate the impact of autologous transfusion on the status of perioperative immune activation inmalignant tumor patients.The Serum Neopterin and Interleukin-2(IL-2)were measured.Methods:Sixty patients undergoingelective radical resection for malignant stomach tumor were enrolled in the prospective study and assigned to the following groups:(Ⅰ)Group A received autologous transfusion;(2)Group H received allogeneic transfusion.The perioperative course(Beforeinduction of anesthesia,after operation and 5 d after operation)of Neopterin and IL-2 was compared.Results:In group A,SerumNeopterin was significantly lower than baseline alter operation and IL-2 had no significant changes.In group H,both SerumNeopterin and IL-2 were significantly lower than baseline alter operation and 5 d after operation.Compared with group A,SerumNeopterin was significantly lower than baseline alter operation and 5 d after operation and IL-2 was significantly lower thanbaseline 5 d alter operation.Conchision:Autologous transfusion decreased the perioperative immune suppression in malignantstomach tumor patients.

Volumetric fraction measurement in oil-water-gas multiphase flow with dual energy gamma-ray system

Volumetric fraction distribution measurement is a constituent part of process tomography system in oil-water-gas multiphase flow. With the technological development of nuclear radial inspection, dual-energy γ-ray techniques make it possible to investigate the concentration of the different components on the cross-section of oil-water-gas multiphase pipe-flow. The dual-energy gamma-ray technique is based on materials attenuation coefficients measurement comprised of two radioactive isotopes of 241Am and 241Cs which have emission energies at 59.5 keV and 662 keV in this project. Nuclear instruments and data acquisition system were designed to measure the material’s attenuation dose rate and a number of static tests were conducted at the Multiphase Laboratory, Institute of Mechanics, Chinese Academy of Sciences. Three phases of oil-water-gas media were inves- tigated for their possible use to simulate different media volumetric fraction distributions in experimental vessels. Attenuation intensities were measured, and the arithmetic of linear attenuation coefficients and the equations of volumetric fractions were studied. Investigation of an unexpected measurement error from attenuation equations revealed that a modified arithmetic was involved and finally the system achieved acceptable accuracy in experimental research.

Efficient Extraction of Tea Saponin from Tea Seed Meals by ^(60)Coγ-Irradiation

In order to simplify the extraction process of tea saponin and improve its extraction rate,tea seed meals was taken as materials to explore effects of ^(60)Coγ-irradiation and H_(2)O_(2) on the extraction rate of tea saponin.The results showed that the optimal crude extract condition of tea saponin was 6%H_(2)O_(2) and an irradiation dose of 5 kGy,the extraction rate was 46.4%.However,when the irradiation dose and the H_(2)O_(2) concentration continued to increase,the extraction rate of tea saponin decreased.After flocculate extraction,the tea saponin content increased from 40.80%to 48.32%.Foaming property test results showed that the higher the tea saponin content in the solution was,the higher the foaming height will be,and the foam had a certain stability.This work provided a new method for the extraction of natural products,usingγ-ray irradiation and H_(2)O_(2) pretreatment to improve the extraction rate,and this was of great significance for industrial extraction.

Extractability of Cu in Alkaline Biosolids-Amended Soilsas Influenced by γ-Irradiation

An incubation experiment was conducted to investigate themicrobial biomass associated Cu in four contrasting soils to which analkaline stabilised sewage sludge cake was applied. The organisms ofsludge- amended and control soils were killed using γ-irradiationtechnique, and the aqueous and acid-extractable Cu concentrationswere determined. Addition of the sludge product increasedsignificantly the concentration of both the aqueous and diluteHOAc-extractable Cu in all the irradiated soils compared to thenon-sterilised sludge/soil mixtures, but the increase was morepronounced in the dilute acid-extractable Cu, indicating that the Curendered extractable in water and dilute acetic acid by γ-irradiation existed in the both soil liquid and solid phases. Theadditional increase in extractable Cu following the biocidaltreatment is likely to be due to release of Cu from the same fractionof soil microbial biomass.

Effects of N/Z on Post-Saddle γ Emission as an Observable of Post-Saddle Nuclear Friction

Based on a dynamical Langevin equation coupled with a statistical decay model, we calculate the variation of the post-saddle giant dipole resonance （GDR） q-ray multiplicity of the heavy nuclei 24^240Cf, ^246Cf, ^252Cf and ^240U with the post-saddle friction strength （13）. We find that the sensitivity of the post-saddle γ emission to β decreases considerably with increasing the neutron-to-proton ratio （N/Z） of the system. Moreover, for 240 U, the γ emission is no longer sensitive to 13. We suggest that to accurately obtain information of the post-saddle friction strength by measuring pre-scission GDR γ-ray multiplicities, it is optimal to choose among the various compound systems those with low N/Z.

A Detailed Study of Pre-scission γ Emission as a Probe of Nuclear Dissipation

Using a Langevin equation coupled with a statistical model, we calculate pre-scission giant dipole resonance （GDR） γ-ray multiplicity of nuclei 194 pb, 200Pb, 206Pb, and 200 Os. It is demonstrated that with increasing the isospin asymmetry of these fissioning nuclei the sensitivity of the emitted γ multiplicity to the nuclear viscosity coefficient is decreased significantly. For 200Os nuc/eus, this γ-ray emission is no longer sensitive to the magnitude of the viscosity coefficient. In addition, the effect of the isospin asymmetry on the γ rays as a probe of nuclear dissipation is reduced with increasing angular momentum. These results suggest that to obtain a more accurate information of the viscosity coemfficient by the measurement of pre-scission GDR γ-ray multiplicity it is better to choose those compound systems with small isospin asymmetry and low spin.

NONLINEAR RESPONSES OF GAMMA-RAY DOSIMETERS

Either sublinear or supralinear responses of dosimeters to y-ray can be described by a response function derived from statistical Poisson distribution.The characteristic parameters of the function determine linearity, sublinearity and supralinearity in their responses. The experimental data of gamma dose-responses of alanine ESR dosimeters,film dosimeters, LiF(Mg, Cu, P) and LiF(Mg, Ti) thermoluminescence dosimeters are used to test the response function.

Study on absorption coefficients of dual-energy γ-rays in determining phase fractions of multiphase flows

This paper discusses the principle and mathematical method to measure the phase fractions of multiphase flows by using a dual-energy gamma-ray system. The dual-energy gamma-ray device is composed of radioactive isotopes of 241Am and 137Cs with emission energies of 59.5 keV and 662 keV respectively. A rational method to calibrate the absorption coefficient was introduced in detail. The statistical error has been analyzed on the basis of the accurate absorption coefficient which enables determination phrase fractions almost independent of the flow regime. Improvement has been achieved on the measurement accuracy of phase fractions.

Effect of γ-ray Radiation on the Loss of Optical Fiber in Visible Range

The mechanism of γ-ray radiation induced absorption loss of the optical fiber in visible range is analyzed. According to the mechanism, the quantitative relation between loss in optical fiber and γ-ray cumulation dose is found by use of methods of solid physics and statistic physics. This quantitative relation is certified in terms of the results of radiation experiment.

Characterization of pH-sensitive Poly (acrylic acid-co-N-vinyl-2-pyrrolidone) Hydrogels Prepared by Gamma Radiation

The pH-sensitive copolymer hydrogels were prepared with the monomers of acrylic acid and N-vinyl-2-pyrrolidone based on gamma radiation technique. The morphology of the hydrogels was monitored by using scanning electron microscope. The influence of absorbed dose, monomer composition and concentration on the swelling ratio (SR) of the hydrogels were investigated in detail. The effect of pH and temperature of the swelling medium on the swelling behavior of the hydrogels were also examined. The results show that the SR of the copolymer hydrogels decreases with the monomer concentration and absorbed dose increasing. The copolymer hydrogels show a better pH-sensitive behavior. In alkaline solution, the SR of the hydrogels is much higher than in acid solution.

Gefitinib combined with γ-ray stereotactic body radiation therapy has better efficacy than gefitinib alone for senile lung adenocarcinoma patients with EGFR mutations as first-line regimen

Objective： The senile lung adenocarcinoma patients harboring an activating epidermal growth factor receptor （EGFR） mutation shows good and rapid response to EGFR tyrosine kinase inhibitors （TKIs）. Whether gefitinib combined with y-ray stereotactic body radiation therapy has better efficacy than gefitinib alone for senile lung adenocarcinoma patients with EGFR mutations as first-line regimen is still under investigation. Methods： The 42 senile lung adenocarcinoma patients with EGFR mutations were divided into 2 groups according to the therapy method. Group A was the 22 patients treated with gefitinib combined with y-ray stereotactic body radiation therapy （SBRT）. Group B was the 20 patients treated with gefitinib alone. All of the patients received gefitinib of 250 mg/d from the first day until disease progression or other reasons. The patients of Group A were treated with y-ray stereotactic body radiation therapy from the second day. Radiation fields included the primary lesions and the integration of lymph nodes. Dose curve of this group was 50%-80%. Encircled dose was 4.0-6.5 Gy per fraction and the range of total dose was 40-52 Gy. We treated the patients 8-12 times and treated five times every week. Results： All the patients were examined by enhanced double helix CT at the second month. The tumor response rate （RR） of group A was 81.8% （18/22）. Disease control rate （DCR） was 90.9% （20/22）. The median overall survival （OS） was 24.2 months （range 8-58 months ） and the progression-free survival （PFS） was 18.6 months. The overall 1-year survival rate was 72.3% （16/22） and 2-year survival rate was 54.5% （12/22）. The main side effects included skin rash and diarrhea. The RR of group B was 50.0 % （10/20）. DCR was 75.0% （15/20）. OS was 17.4 months （range 6-32 months ） and PFS was 12.1 months. The overall 1-year survival rate was 60.0% （12/20） and 2-year survival rate was 40.0% （8/20）. The main side effects included skin rash and diarrhea. The group A who were treated with gefitinib combined with y-ray stereotactic body radiation therapy had a higher short term therapeutic effects （RR） and long term therapeutic effects （OS） than group B who were treated with gefitinib alone respectively （81.8% vs 50.0%, P = 0.029 〈 0.05, x2 = 4.773 and 24.2 vs 17.4, P = 0.024 〈 0.05, X2 = 5.098）. Conclu. sion： Gefitinib combined with y-ray stereotactic body radiation therapy has better efficacy than gefitinib alone for senile lung adenocarcinoma patients with EGFR mutations as first-line regimen. The side affects are acceptable.

Clinical study on gefitinib combined with γ-ray stereotactic radiotherapy for senile patients with adenocarcinoma of lung as the first-line regimen

Objective: The aim of our study was to evaluate the efficacy and safety of gefitinib combined with γ-ray stereo-tactic radiotherapy for senile patients with adenocarcinoma of lung as the first-line regimen. Methods: The 153 senile patients with adenocarcinoma of lung were divided into 4 groups according to the therapy method. Group A was the 35 patients treated with gefitinib combined with γ-ray stereotactic radiotherapy. Group B was the 45 patients treated with γ-ray stereotactic radio-therapy. Group C was the 42 patients treated with gefitinib. Group D was the 31 patients treated with best supportive therapy. The patients received gefitinib of 250 mg/d from the first day until disease progression or other reasons. The patients were treated with γ-ray stereotactic radiotherapy from the second day. Dose curve of this group of cases was 50%-80%. Encircled dose was 4.0-6.5 Gy per fraction and the range of total dose was 36-48 Gy. The total number of treatment was 8-12 and treated six times every week. Results: All the patients were examined by enhanced double helix CT at the second month. The tumor response rate (RR) of group A was 68.6% (24/35). Disease control rate (DCR) was 88.6% (31/35). The median survival time (MST) was 13.4 months (range 3-34 months ) and the progression-free survival (PFS) was 7.8 months. The overall 1-year survival rate was 40.0% (14/35). The main side effects included skin rash and diarrhea. The RR of group B was 51.1% (23/45). DCR was 71.1% (32/45). MST was 9.6 months (range, 3-18 months ) and PFS was 5.3 months. The overall 1-year survival rate was 15.6 % (7/45). The RR of group C was 40.5 % (17/42). DCR was 61.9% (26 /42). MST was 10.3 months (range, 3-26 months ) and PFS was 5.1 months. The overall 1-year survival rate was 35.7 % (15/42). The main side effects included skin rash and diarrhea. The MST of group D was 5.6 months (range, 2-11 months ) and PFS was 1.7 months. The overall 1-year survival rate was 0. The short-term therapeutic effects (RR) of group A was higher than group C (P = 0.014 < 0.05, χ2 = 6.053) but has no significant difference with group B (P = 0.116 > 0.05, χ2 = 2.477). The long-term therapeutic effects (overall 1-year survival rate) of group A was higher than group B (P = 0.014 < 0.05, χ2 = 6.077) but has no significant difference with group C (P = 0.642 > 0.05, χ2 = 0.216). Conclusion: Gefitinib combined with γ-ray stereotactic radiotherapy is feasible and effective for treatment in senile patients with adenocarcinoma of lung as the first-line regimen.

The impact of ^(60)Co γ-ray on apoptosis to Hep-2 human laryngeal cancer cell in the condition of reoxygenation after hypoxia

Objective： The aim of the study was to establish models of Hep-2 laryngeal cancer cell line of different oxygen supplying, trying to investigate the impact of normoxia, hypoxia, reoxygenation after hypoxia on apoptosis and expression of proteins HIF-1α and p53 to Hep-2 human laryngeal cancer cell line induced by ^60Co γ-ray. Methods： Human laryngeal cancer Hep-2 cells were divided into 3 groups： group A （normoxia）, group B （hypoxia）, and group C （reoxygenation after hypoxia）. All of the cells were exposed to 5 Gy dosage of γ-ray. Flow cytometry （FCM） was used tomeasure the protein levels of HIF-1α and p53 and to detect cell apoptosis. The protein levels of HIF-la and p53 were also determined by immunohistochemistry and Western blotting. The expression of HIF-la mRNA was determined by RT-PCR. Results： The protein levels of HIF-1α and p53 were evidently increased in group B compared to group A. The protein levels of HIF-1α and p53 in group C were lower compared to group B; the rate of apoptosis in group C was higher than that in group B. Conclusion： Hypoxia decreased the effect of apoptosis induced by ^60Co γ-ray in Hep-2 human laryngeal cancer cell line. The apoptosis pathway maybe related to some other genes or proteins but not p53 in the conditions of hypoxia and reoxygenation after hypoxia.