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采用昆明种小鼠3Gy全身照射为模型,分离培养照后8h~15d共6个时相点全小肠粘膜上皮内淋巴细胞,并对其数量、细胞增殖活力、细胞毒力、TNF-α和TGF-β分泌水平进行检测。结果表明小肠上皮内淋巴细胞数量显著下降,增殖活力和细胞毒力明显受抑,表现为照后8h下降,72h达低值。上皮内淋巴细胞分泌TNF-α和TGF-β显著增多,表现为照后8h增高,72h达峰值。小肠上皮内淋巴细胞数量减少和功能降低成为全身放射损伤时造成肠粘膜免疫屏障功能受损的一个重要原因。 相似文献
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以BALB/c小鼠为研究对象,用^60Coγ射线进行11.5Gy的腹部一次照射,照后1—3h采用局部肠腔扩张注入法给小鼠空肠肠腔内注入正常大鼠小肠核糖核酸(Ribonucleic acid,RNA),照后1、3、5d取全小肠,制备肠粘液,测定免疫球蛋白分泌型免疫球蛋白A(Secreted immunoglobulinA,sIgA)含量;取空肠段,观察肠绒毛形态变化;取血,测定内毒素含量;取肠系膜淋巴结,测定细菌移位率。探讨小肠RNA对γ射线照射后小鼠肠粘膜屏障的保护作用。结果表明,小肠RNA可明显提高受照后小鼠肠粘液中免疫球蛋白sIgA的含量(p〈0.01),减轻肠绒毛的萎缩及塌陷,改善肠粘膜形态结构,降低肠系膜淋巴结细菌移位率和血中内毒素含量。以上结果显示,小肠RNA对γ线照射后的小鼠肠粘膜屏障有明显的保护作用,能抑制肠道细菌移位和肠内内毒素的吸收。 相似文献
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本文介绍用3H-TdR 掺入示踪技术,探讨了外源性白细胞介素-1(rIL-1)和外源性白细胞介素-2(rIL-2)对浓缩铀 UO_2F_2损伤小鼠脾脏 B 淋巴细胞的防护作用。经 BALB/c 小白鼠尾静脉注入20mg/kg 体重的浓缩铀 UO_2F_2 48 h 后,无菌取脾,制成单细胞悬液加入细菌脂多糖(LPS)、rIL-1或 rIL-2常规培养,以淋巴细胞 DNA 中~3H-TdR 掺入量的变化来衡量 B 淋巴细胞的增殖能力。结果表明,浓缩铀 UO_2F_2能明显抑制小鼠脾脏 B 淋巴细胞 DNA 的合成,使 B 淋巴细胞增殖受到明显抑制;rIL-1和 rIL-2可使受浓缩铀 UO_2F_2损伤的小鼠脾脏 B 淋巴细胞的增殖抑制部分逆转,最大增殖率分别为67%和51%;二者合并使用时可使增殖率增至83%。 相似文献
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小剂量照射后小鼠脾巨噬细胞对脾淋巴细胞功能的… 总被引:2,自引:0,他引:2
采用昆明小鼠,小剂量X射线全身照射50mGy ̄250mGy,剂量率为12.5mGy/min。停照后不同时间处死动物,取出脾脏,用贴壁法分离脾巨噬细胞(MΦ)和淋巴细胞,检测受照后脾MΦ与受照的脾淋巴细胞功能变化的关系。结果表明,小剂量辐射可使脾MΦ功能增强,主要表现在75mGyX射线全身照射后,脾MΦ对脾淋巴细胞ConA(刀豆蛋白A)反应增强,IL-1(白细胞介素1)分泌增多。受照的脾MΦ只对受照 相似文献
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采用昆明小鼠,小剂量X射线全身照射50mGy~250mGy,剂量率为12.5mGy/min。停照后不同时间处死动物,取出脾脏。用贴壁法分离脾巨噬细胞(Mφ)和淋巴细胞,检测受照后脾Mφ与受照的脾淋巴细胞功能变化的关系。结果表明,小剂量辐射可使脾Mφ功能增强,主要表现在75mGyX射线全身照射后,脾Mφ对脾淋巴细胞ConA(刀豆蛋白A)反应增强,IL-1(白细胞介素1)分泌增多,受照的脾Mφ只对受照的脾淋巴细胞增强其ConA反应,而对未受照的脾淋巴细胞无显著影响;未受照的脾Mφ也不能增强受照的脾淋巴细胞功能 相似文献
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腹部、盆腔的晚期肿瘤患者在接受肿瘤放射治疗时,射线对肠道正常组织也会造成明显的损伤。研究发现,上调体内缺氧诱导因子(Hypoxia-inducible factor,HIF)水平能起到防护肠道组织辐射损伤的作用。通过脯氨酸羟化酶抑制剂等上调体内HIF水平,减轻肠道上皮细胞、肠道隐窝干细胞损伤程度,维持肠道屏障完整性;上调血管内皮生长因子表达水平,保护肠道微血管内皮;调控NF-?B、炎症因子分泌以及树突状细胞的免疫功能,减缓肠道辐射损伤的炎症反应。本文还对HIF与肿瘤的关系进行了讨论。 相似文献
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褪黑素对电离辐射所致C57BL/6J小鼠免疫功能损伤的防护作用 总被引:2,自引:0,他引:2
探讨了褪黑素(Melatonin,MLT)对电离辐射诱导小鼠免疫功能损伤的影响及其机制.采用C57BL/6J小鼠,腹腔注射MLT后60min给予2Gy X射线全身照射,观察照射后24h其胸腺、脾淋巴细胞数量及胸腺细胞3H-TdR掺入率和Con A、LPS诱导的脾T、B淋巴细胞转化率的变化.结果表明,2Gy X射线全身照射后24h,小鼠胸腺、脾淋巴细胞数量、胸腺细胞3H-TdR掺入率及有丝分裂原诱导的脾T、B淋巴细胞转化率均显著低于假照组(p<0.001).以MLT 0.5-10mg@kg-1体重预先腹腔注射,受照射小鼠免疫功能发生如下变化:胸腺、脾淋巴细胞数显著高于0mg组(单纯照射).其中,0.5mg组增高最显著;胸腺细胞3H-TdR掺入率显著增高(p<0.01或p<0.001),以0.5mg组增高最显著;ConA诱导的T淋巴细胞转化率显著增高,也以0.5mg组为最显著;细菌脂多糖(LPS)诱导的B淋巴细胞转化率增高,以10mg组最显著.此外,2.5mg组MLT可增强无丝裂原诱导的脾淋巴细胞转化率.MLT可减轻电离辐射诱导的小鼠淋巴细胞损伤,对免疫功能具有保护作用. 相似文献
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高能电子线辐射损伤对TGF-β1表达及Ⅰ、Ⅲ型胶原含量的影响 总被引:1,自引:0,他引:1
探讨了高能电子线辐射伤后Ⅰ、Ⅲ型胶原含量的改变情况及TGF-β1对其的调控作用。采用电子直线加速器照射制作动物的辐射损伤模型,对NIH3T3细胞进行照射,观察胶原总量及Ⅰ、Ⅲ型胶原含量的改变;测定损伤后细胞因子TGF-β1表达的变化情况。结果显示,损伤后胶原总量变化不大,而Ⅰ型胶原含量下降,Ⅲ型胶原含量上升;损伤后TGF-β1表达量增加。结果提示,放射性皮肤损伤引起了胶原代谢的变化,损伤后胶原代谢的调控机制中,TGF-β1可能起重要作用。 相似文献
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LIU Xiuhua XU Yunshu ZHONG Zhijing FU Yibei DENG Yi 《核技术(英文版)》2007,18(1):59-64
Zn-doped TiO2 catalysts were prepared using a sol-gel method and characterized by XPS,UV-Vis, BET, XRD in this study. Under the irradiation of simulant sunlight, the photocatalytic activity for the degradation of p-nitrophenol was studied too. After irradiation for 2.5 h, the degradation percentage of p-nitrophenol could rise to more than 80 %. The results showed that the spectrum absorption band edge of Zn/TiO2 powder does not broaden obviously comparing with pure TiO2 powder. Zinc exists as Zn (11). When calcined at 973 K, there is a new phase as ZnTiO3 in Zn/TiO2 catalyst. The order of photocatalytic activity of Zn/TiO2 catalysts calcined at different temperatures for p-nitrophenol is 773 K 〉 673 K 〉 873 K 〉 573 K 〉 973 K and the photocatalytic activity of Zn/TiO2 catalyst calcined at 773 K is better than TiO2 catalysts heated at the same temperature, and outclasses that of commercial TiO2 catalyst. It also showed that the photocatalytic degradation of p-nitrophenol follows first-order kinetics under the irradiation of simulant sunlight. 相似文献
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FU Shen SUNYi LU Yaohong 《核技术(英文版)》2007,18(2):65-72
Radiotherapy for the treatment of prostate cancer has been extensively explored in the past. Along with the comprehensive understanding of the biology of prostate cancer and rapid advances in terms of technology, the out- come of treatment for the patients with prostate cancer has improved. The authors review radiotherapy as the primary treatment for the disease, with particular emphasis on the technological advances from both the radiobiological and radiophysics aspects. Nonconventional fractionated irradiation like hyper- or hypo-fractionation has been imple- mented in the clinic, the final results still need to be confirmed in the future. Technological advances like IMRT, IGRT, in the last two decades have significantly improved the delivery of external radiotherapy to the prostate. This has re- sulted in an overall increase in the total dose that can be safely delivered to the prostate, which has led to modest im- provements in the biochemical outcome. However, establishing the standard therapy for prostate cancer remains con- troversial. It is hoped that the next decades will bring continued advances in the development of biologicals that will further improve current clinical outcomes. 相似文献
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This paper introduces the injection and extraction control system design for SSRF,which is a distributed control system aimed at stability and reliability of the pulse power supplies,PPS(Personnel Protection System)and MPS(Machine Protection System).The hardware environment is mainly based on PLC(Programmable Logic Con- troller),and ARM(Advanced RISC Machine)is also applied for studying stability of the power supplies.WinCC and EPICS(Experimental Physics and Industrial Control System)have been selected as the platforms of SCADA(Super- visory Control and Data Acquisition).For unifying the interfacing to the control computer,all front-end equipments are connected via Industrial Ethemet. 相似文献
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为研究含空气蒸汽在水平管内强制对流冷凝换热特性,基于对传热传质过程的分析,建立了管内为环状流与波状流条件下的流动冷凝换热模型。从潜热、显热和液膜3个环节对整个换热过程进行建模,最终得到计算局部冷凝换热系数的理论关系式。模型预测结果与实验数据的对比表明,二者相对偏差在±20%以内,验证了该换热模型的准确性与适用性。通过进一步的研究发现:从换热管入口至出口,随着冷凝的进行,管内换热主要热阻由液膜热阻向气液界面的凝结热阻转变;主流气体对流换热过程基本可忽略。 相似文献
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D.Rezaei OCHBELAGH H.Miri HAKIMABAD R.Izadi NAJAFABADI 《核技术(英文版)》2007,18(4):237-241
Experiments were carried out to investigate the possible use of neutron backscattering for the detection of polyethylene (PE) sample buried in the soil. In detection of landmine by neutrons, the neutron detector and its shield play an important role. In this paper, the effects of graphite, heavy water, polyethylene and boric acid moderators on the flux of back scattered neutrons were investigated. We have also experimentally verified the effect of BF3 detector shield and obtained good agreement with theory. 相似文献
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LI Lin SHEN Liren ZHU Qing WAN Tianmin 《核技术(英文版)》2007,18(4):193-197
Accelerator database stores various static parameters and real-time data of accelerator. SSRF (Shanghai Synchrotron Radiation Facility) adopts relational database to save the data. We developed a data retrieval system based on XML Web Services for accessing the archive data. It includes a bottom layer interface and an interface applicable for accelerator physics. Client samples exemplifying how to consume the interface are given. The users can browse, retrieve and plot data by the client samples. Also, we give a method to test its stability. The test result and performance are described. 相似文献
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Distributions of natural gamma-emitting radionuclides were determined in 93 oil samples collected from some petroleum fields in the western desert of Egypt. The radioisotope activities in the area under investigation lay in the range of (21 ± 4) to (38 ± 13) Bq?L-1 for 226Ra, (9 ± 2) to (15 ± 5) Bq?L-1 for 232Th, and (154 ± 28) to (303 ± 54) Bq?L-1 for 40K. The mean values were 27, 12, and 201 Bq?L-1, respectively. Among oils, variations in radionuclide ac- tivities could be on account of differences in TDS, HCO3, and Ba, with high or low pH. In this environment, oil prop- erties differently affected the mobilization of natural radionuclides. The range of 226Ra variation had been compared with available data from other countries. The calculated absorbed dose rate ranged from 22.33 to 32.66 nGy?h-1 in lo- cation (B) and (E) respectively, which was less than the accepted value. 相似文献
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In this work,TTHMP was synthesized and labelled with 117m Sn.The preparation conditions,stability and lipophilicity of 117m Sn(IV)-TTHMP were investigated.Biodistribution of the complex in rabbits and mice was studied.It was found that the quantity of TTHMP and pH value of the prepararion solution had vital effects on the labeling yield of 117m Sn(IV)-TTHMP.It was also found that 117m Sn(IV)-TTHMP was hydrophilic and stable at room temperature and 37℃ in open air 117m Sn(IV)-TTHMP showed unexpectedly high bone uptake and bone-to-blood ratio in the animals.This made it potentially useful as an reagent for skeletal scintigraphy and radiotherapy of bone tumors. 相似文献
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WENG Jianqing HE Jun XIANG Yuanyi WANG Kan LI Xia HAN Zhengdong 《核技术(英文版)》2007,18(6):366-371
Monitoring results of gamma dose rate level in 1992~2004 in the ambient environment of the Qinshan Nuclear Power Plants(QNPP)Base,the northeast of Zhejiang Province,are reported in this paper.It is shown that the gamma dose rate of five monitoring sites of 2.5 km to QNPP Base is 84~113 nGy/h,with an average of 96 nGy/h in the 13 years.The average value is close to the background level of 93 nGy/h prior to operation of the QNPP Base,and is lower than the monitoring result of 101 nGy/h at the reference site in Hangzhou City.Within 50 km from the QNPP Base,the cumulative dose rate of the thermoluminescent dosimeter(TLD)is 90 nGy/h,which is lower than the back- ground level of 111 nGy/h. 相似文献
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LI Zhaobin XIONG Fei HUANG Guofeng CAO Zheng JIANG Ruiyao FU Shen 《核技术(英文版)》2007,18(3):145-149
Linear accelerators equipped with multileaf collimators (MLC) are becoming more common and are widely used in the intensity-modulated radiotherapy (IMRT). There is an imperative need to ensure the commissioning specification of the linear accelerators for the sake of quality assurance (QA) and quality control (QC). This paper is aimed to investigate the role of AGFA high-energy CR (Computed Radiography) in calibrating dynamic multileaf collimators and evaluating the accuracy of the leaf position. The result shows that AGFA high-energy CR can easily and conveniently be used to calibrate MLC and verify its position. Hence, the application of AGFA high-energy CR is proved to be an accurate and time-saving method for routine MLC QC, especially when MLC calibration adjustments are required. 相似文献