磺酰胺基取代的咪唑化合物放射增敏作用的研究

研究全新放射增敏剂——磺酰胺取代的咪唑化合物(化学名：简称SIM)在细胞水平和动物水平的放射增敏作用。离体研究采用体外细胞克隆培养法观察不同浓度SIM对乏氧状态下的V79细胞的放射增敏效应。整体研究选取荷Lewis肺癌C577BL小鼠,腹腔注射不同剂量的SIM且2h后给予10Gy的局部照射,观察小鼠的肿瘤体积的变化。结果表明,SIM对V79细胞呈较明显的增敏效应,增敏比为1．12-1．81。给药照射组的肿瘤相对生长速率明显减慢。研究提示是一个新型的放射增敏剂。     

氚示踪法研究吲哚美辛在C57小鼠体内的分布及其抗肿瘤作用

采用氚标记吲哚美辛(Indomethacin,IN)示踪技术,观察3H-IN在Lewis肺癌C57小鼠体内的分布及IN治疗Lewis肺癌的效果。结果显示:3H-IN选择性浓聚于肿瘤组织,服药后4 h肿瘤组织的放射性摄取(ID％／g)达较高水平,此后其清除速率明显慢于其它组织;服药后7 h,肿瘤组织与肌肉、脂肪、血液之间的放射性摄取有差异(P<0.05),12 h差异显著(P<0.01)。肿瘤组织与肌肉、脂肪、血液的放射性摄取比4 h开始>1,12 h达最高。IN的抑瘤和抗癌作用结果显示:用IN治疗的Lewis肺癌C57小鼠在接种后第20天肿瘤体积为3.59 cm2,仅服用生理盐水的小鼠(对照组)肿瘤体积为8.37 cm2,其抑瘤率为57.1％;接种肿瘤早期即口服IN的小鼠未见肿瘤生长。以上结果表明IN有较强的肿瘤靶器官亲和性,可选择性浓聚于肿瘤组织,并长时间存留,具有较强的抑制肿瘤及抗肿瘤作用。     

γ射线照射C6、SGH-446与NCI-H446肿瘤细胞的三维结构变化和DNA辐射损伤

脑胶质瘤是常见恶性肿瘤,我国脑胶质瘤发病率占脑肿瘤40％以上,占全部肿瘤的1％-3％,由于血-脑屏障作用,神经胶质瘤对射线并不敏感,放疗的治疗比值较小,化疗也不理想。寻找神经胶质瘤细胞的耐辐射基因,探讨其耐辐射机制,可望为脑胶质瘤放疗增敏提供指导,提高患者术后的生存率。本研究用小鼠脑胶质瘤(C6)、人脑胶质瘤(SHG-44)和小细胞肺癌(NCI-H446)等细胞株、     

甲硝唑氨酸钠对小鼠肿瘤分次照射的增敏作用

荷Ｌｅｗｉｓ肺癌和ＥＭＴ６乳腺癌小鼠肿瘤局部进行分次照射，实验组加用ＣＭＮａ或ｍｅｔｒｏｎｉ－ｄａｚｏｌｅ处理，结果表明，单独分次照射表现出一定的治疗效果。加用ＣＭＮａ后肿瘤相对增长速度明显减慢，肿瘤抑制率和肿瘤生长延迟天数明显增加，表现出明显的放射增敏作用。     

马蔺子甲素及其衍生物对荷S180小鼠肉瘤的重离子辐射增敏效应

研究了马蔺子甲素（Ｑ）及其衍生物（Ｑ１－Ｑ８）对荷Ｓ１８０肉瘤小鼠的辐射增敏作用。应用动脉夹阻断局部血流以造成肉瘤乏氧的方法来研究对小鼠Ｓ１８０肉瘤乏氧细胞的辐射增敏作用。实验结果表明：与对照组相比,照射前腹腔注射Ｑｎ后,肉瘤氧增比减小,肉瘤体积变小,增敏比及肉瘤抑瘤率增加,表现出Ｑｎ对肉瘤的抑制作用。有氧和乏氧条件相比,乏氧条件的辐射增敏作用更明显。体外乏氧细胞毒比率的结果也表明,此类药物对乏氧     

甲硝唑氨酸钠（CMNa）对小鼠肿瘤分次照射的增敏作用

荷Ｌｅｗｉｓ肺癌和ＥＭＴＧ乳腺癌小鼠肿瘤局部进行分次照射，实验组加用ＣＭＮａ或ｍｅｔｒｏｎｉ－ｄａｚｏｌｅ处理。结果表明，单独分次照射表现出一定的治疗效果。加用ＣＭＮａ后肿瘤相对增长速度明显减慢，肿瘤抑制率和肿瘤生长延迟天数明显增加，表现出明显的放射增敏作用。     

18F-FDG对小鼠Lewis肺癌移植瘤抑制作用的实验研究

建立Lewis肺癌C57BL/6小鼠皮下移植瘤模型18只,按随机数字法分为高剂量18F-FDG治疗组、低剂量18F-FDG治疗组和对照组,每组6只,分别给予18F-FDG 18.5×107Bq、9.25×107Bq和0.2 mL等体积的生理盐水,于接种后第7天腹腔内一次给药,观察18F-FDG对Lewis肺癌移植瘤体积变化和瘤重的影响。22天后用流式细胞仪检测细胞凋亡,以免疫组化法检测bcl-2及Survivin基因的蛋白表达。发现18F-FDG高、低剂量组肿瘤抑瘤率及凋亡率明显高于对照组,Bcl-2及Survivin蛋白的表达明显低于对照组(P<0.05),与低剂量组相比,高剂量组与对照间差异更为显著(P<0.01)。这表明18F-FDG可明显抑制小鼠Lewis肺癌移植瘤生长,其机制可能与下调Bcl-2及Survivin蛋白的表达促进细胞凋亡有关。     

新型吲哚醌类生物还原活性物629的细胞毒性和辐射增敏作用的研究

研究丝裂霉素C（Mitomycin C，MMC）的衍生物一新型吲哚醌类生物还原活性物629的细胞毒性和辐射增敏作用。采用四氮甲基唑蓝（Methyl thiazolyl tetrazolium，MMT）比色法研究MMC和629对HepG2细胞的细胞毒性以及629对肝原代细胞的细胞毒性，结果表明629对肝原代细胞无毒性作用，而其对HepG2肝癌细胞的毒性要高于其母体化合物MMC；此外，采用体外细胞克隆培养法观察MMC和629对HepG2细胞的辐射增敏作用，结果显示629的辐射增敏效果强于MMC。上述研究提示，629具有低毒的增敏效果，在临床上将具有广泛的应用远景。     

99Tcm-HL91乏氧显像预测高压氧放疗增敏的可行性

目的99mTc-HL91乏氧显像预测高压氧对肿瘤的放疗增敏情况。方法40只荷H22肝癌小鼠均分为4组,每组10只;①对照组,不进行高压氧治疗,其中5只行99mTc-HL91乏氧显像,5只行照射治疗;②15分钟组;③30分钟组;④60分钟组,后3组小鼠按高压氧后不同时间顺序,其中5只行99mTc-HL91乏氧显像,其余5只行照射治疗。各组显像小鼠通过核医学感兴趣区（regionfinteresting,ROI）技术,计算肿瘤与对侧相应部位放射性比值（T/NT）。图像采集结束后立即处死小鼠,完整剥离肿瘤,称重并计算放射性计数,计算肿瘤微分摄取率（DUR）。各组照射治疗小鼠均记录肿瘤照射后生长天数及小鼠平均存活时间。结果 与对照组比较,15分钟组、30分钟组DUR值、T/NT值、肿瘤及小鼠生长延迟天数,差异有显著性（P<0.05）,60分钟组,各数值均未见显著性差异（P>0.05）。结论99mTc-HL91乏氧显像是一种有效预测高压氧增敏效果的方法,且高压氧增敏作用随时间延长逐渐减弱。     

超氧化物歧化酶与阿米福汀对小鼠急性放射损伤预防作用的比较

本研究建立了小鼠全身放疗的损伤模型,以比较预给药超氧化物歧化酶(SOD)和阿米福汀对小鼠放射治疗损伤的防护效果。C57BL/6小鼠用6 Gy X射线进行全身一次性照射,在放射后24 h处死,测定小鼠外周血红、白细胞数量,胸腺指数和脾脏指数,以及肝脏抗氧化活力。结果表明:与放疗对照组相比,放疗前给药SOD组对放疗鼠的外周血白细胞数量和胸腺指数有显著的保护作用,使之分别增加66.7%和19.1%。测得放疗前给药阿米福汀对放射鼠的外周血白细胞数量和脾脏指数有显著的保护作用,使之分别增加106.9%和22.6%。此外,与放疗对照组相比,放疗前给药SOD对放疗鼠的肝脏抗氧化能力也有显著提高,可使肝脏的MDA水平下降12.7%,SOD活力增加10.8%,T-AOC活力增加45.0%,放疗前给药阿米福汀可使放疗鼠肝脏的MDA水平下降22.3%。     

Preparation of Zn/TiO2 powder and its photocatalytic performance for oxidation of P-nitrophenol

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.     

Current status of radiation therapy for prostate cancer

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.     

The control system for SSRF injection and extraction

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.     

水平管内含空气蒸汽强制对流冷凝换热模型研究

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。     

Investigations on landmine detection by BF3 detector

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.     

Web Services interface of SSRF archive data analysis system

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.     

Assessment of radioactivity levels in some oil samples from the western desert, Egypt

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.     

Preparation and properties of 117m Sn(IV)-TTHMP in in-vitro and in small animals

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.     

Gamma radiation levels in the ambient environment of the QNPP Base

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.     

The role of AGFA high-energy CR in the calibration and quality control of multileaf collimators （MLC）

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.