辐射聚合覆盖离子型高分子的纸固定化绿色木霉细胞

通过辐射聚合,在纸表面覆盖阳离子——疏水性共聚物polo(DEAEMA-ATMPT)和阴离子——疏水性共聚物poly(AA-ATMPT)作为固定化绿色木霉细胞的载体。试验结果表明:用覆盖poly(DEAEMA-ATMPT)的载体固定化细胞比较牢固,未因振荡而解吸;固定化细胞的FPA(滤纸活性)均高于未固定化的游离细胞,其中用覆盖25％:75％ poly(DEAEMA-ATMPT)的载体固定化细胞的FPA比游离细胞增加了20％;固定化细胞的重量随共聚物中阳离子组分的增加而增加。用覆盖poly(AA-ATMPT)的载体固定化绿色木霉也有较好的效果。但固定化细胞的重量明显低于覆盖poly(DEAEMA-ATMPT)的载体固定化细胞的重量,且它随共聚物中阴离子组分的增加而下降。阳离子——疏水性共聚物能提高固定化绿色水霉的效果;用离子型共聚材料固定化细胞静电引力起了主要的作用。     

辐射共聚制备固定化酒精酵细胞的研究

在低温（－７８℃）条件下，用＾６０Ｃｒγ射线对单体丙烯酸羟乙酯（ＨＥＡ）与聚乙二醇二甲基丙烯酸酯系列单体１４Ｇ、９Ｇ、４Ｇ、２Ｇ等进行辐射引发共聚，获得了亲水性共聚合凝胶载体，采用这些载体吸附固定化酒精酵母细胞的乙醇产率均高于游离细胞，其中Ｐｏｌｙ（ＨＥＡ－１４Ｇ）共聚物载体乙醇产率是游离细胞的２．４５倍，１２次分批反应均高于游离细胞。实验结果表明：固定化酵母细胞的乙醇生产率与共聚体系内亲水性单体     

低能电子束循环辐射硫化天然橡胶乳液

应用250keV低能电子束循环辐射硫化二丙烯酸壬酯（1,9-nonanedilo diacrylate，NDDA）敏化的天然橡胶乳液，探讨了影响低能电子束循环辐射硫化天然橡胶乳液的因素。结果表明，提高电子束束流，可缩短辐射硫化时间；40％的天然橡胶乳液更适合低能电子束的辐射硫化；适当提高循环乳液的重量有利于辐射硫化乳液的质量控制。     

烟草霉菌和烟草仓库害虫的辐射灭活效应研究

我们从云南生产的烟叶中分离到7个属的30株霉菌,分别试验了不同霉菌株的辐射灭活效应。试验资料表明:卷烟和烟叶经过吸收剂量为9.0kGy的~(60)Coγ射线辐照处理后,在温度为25～30℃,空气相对湿度为90％的环境下,可在一年以上的有效保贮期内不遭霉变和虫蛀;烟草的主要化学成份(总糖量、总烟碱、总氮、烟碱氮、蛋白质、总挥发碱、灰份)未发现明显的变化。     

重离子辐射对喹乙醇的作用

研究重离子＾１２Ｃ＾６＋（１．６５６×１０＾４Ｇｙ）、＾１６Ｏ＾５＋（１．５８５×１０＾７Ｇｙ）对喹乙醇的作用，结果表明：两种重离子辐射后１５％以上的喹乙醇结构发生了改变，２６６ｎｍ，３８２ｎｍ二处特征吸收峰随其含量的下降而变平，产生多种辐射产物，重离子辐射后的喹乙醇抗菌作用明显增强。     

^60Coγ辐射对木瓜蛋白酶制剂的杀菌效应

用＾６０Ｃｏγ辐射对木瓜蛋白酶制剂进行灭菌试验，吸收剂量８ＫＧＹ和１２ＫＧＹ，杀菌率分别达到９８．８和９９．９％，酶活力相应地下降２６％和３２％。在木瓜蛋白酶制剂中加入磺化钾和维生素Ｃ时，经８ｋＧｙ剂量照射，酶制剂达到完全灭菌，酶活力下降１５％。     

辐射共聚制备固定化酒精酵母细胞的研究

在低温（－７８℃）条件下，用６０Ｃｏγ射线对单体丙烯酸羟乙酯（ＨＥＡ）与聚乙二醇二甲基丙烯酸酯系列单体１４Ｇ、９Ｇ、４Ｇ、２Ｇ等进行辐射引发共聚，获得了亲水性共聚合凝胶载体，采用这些载体吸附固定化酒精酵母细胞的乙醇产率均高于游离细胞，其中Ｐｏｌｙ（ＨＥＡ—１４Ｇ）共聚物载体乙醇产率是游离细胞的２．４５倍，１２次分批反应均高于游离细胞。实验结果表明：固定化酵母细胞的乙醇生产率与共聚体系内亲水性单体及其它单体的浓度配比、双官能团单体的链长、共聚物载体的水合度以及载体结构、多孔性因素等有关，乙醇生产率的高低取决于载体的膨胀能力和多孔性．     

维生素A对CD4^＋和CD8^＋细胞辐射效应的影响

应用ＣＤ４和ＣＤ８单克隆抗体，采用铺皿法分离并获得ＣＤ４＾＋和ＣＤ８＾＋细胞亚群，间接免疫荧光试验鉴定细胞纯度分别为８９．２％和８５．８％，以＾３Ｈ－ＴｄＲ参入法比较ＣＤ４＾＋，ＣＤ８＾＋细胞辐射敏感性及加入ＶｉｔＡ后对两种细胞亚群ＤＮＡ合成的影响，发现ＣＤ４＾＋和ＣＤ８＾＋细胞经过不同剂量＾６０Ｃｏγ照射后其＾３Ｈ－ＴｄＲ参入均明显下降。加入５μｇ／ｍｌＶｉｔＡ后，受照射的ＣＤ４＾＋细胞参与无明     

6Gy全身辐射对大鼠伤口巨噬细胞功能的影响

以在鼠背部置入聚乙烯醇海绵的切口伤为模型，研究了６Ｇｙ全身辐射对伤口巨噬细胞功能的影响。结果表明在辐射后３、５、８ｄ的伤口不但巨噬细胞数量明显下降，而且巨噬细胞的吞噬功能，ＴＮＦα和ＩＬ－１的释放以及对伤口成纤维细胞增殖的调节能力都明显下降，说明了创伤愈合早期伤口巨细胞数量和功能的下降是辐射造成愈合延迟的重要原因。     

羊抗人IgG和出血热单抗(E_5)在辐射改性的硅橡胶膜上固定化研究

本文用γ辐射技术,在硅橡胶膜(Silastic)上接枝丙烯酰胺单体(AAM),用不同接枝率的Silastic-AAM膜通过叠氮化后对羊抗人IgG和出血热单克隆抗体(E_5)进行了偶联固定化。同位素~(125)碘标记方法对固定在Silastic-AAM膜上的羊抗人IgG量与接枝率的关系,以及抗体量与其免疫活性的关系进行了测定,得到了适于固定化的抗体偶联反应液最适浓度和最佳接枝率范围;用ELISA法对Silastic-AAM膜固定化的出血热(E_5)单抗进行了免疫活性实验,得到了承某一实验条件下具有明显的阳性反应。结果表明,经适当改进,本法对临床诊断有一定应用价值。     

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。     

有效探测面积大于1000 cm2的正比计数器测量系统性能测试

为对自制的活性面积高达1 000 cm²的大面积源进行表面发射率定值,同时作为现有2πα、2πβ表面发射率标准装置能力的扩充,研制了一套内置式大面积2π多丝正比计数器测量系统,并利用活性区直径为8 mm的²⁴¹Am点源及活性区面积为10 cm×15 cm的大面积²⁴¹Am和⁹⁰Sr-⁹⁰Y源对其进行计量学性能测试。结果表明：计数器内计数响应均匀性优于±0.4%,有效探测面积达1 400 cm²;所得²⁴¹Am源高压坪曲线的坪长为1 400 V,坪斜为0.27%/100 V,坪区内计数变化为0.87%;⁹⁰Sr-⁹⁰Y源高压坪曲线的坪长为300 V,坪斜为0.75%/100 V,坪区内计数变化为0.80%;10次测量重复性好于0.4%,8 h内短期稳定性好于0.3%,1 a内长期稳定性好于0.8%。     

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.