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     

辐射制备缓释抗癌药阿糖胞苷的研究

报告了甲基丙烯酸酯类在室温下进行辐射聚合制备缓释抗癌药阿糖胞苷（Ａｒａ－Ｃ）的研究结果。结果表明，不仅亲水性单体，而且疏水性单体（包括ＭＭＡ、ＥＭＡ和ＢＭＡ等）都可用于辐射固化。加入到亲水性基质中的疏水性单体可以延缓药物的离体释放，其顺序是ＭＭＡ＜ＥＭＡ＜ＢＭＡ，央ＭＭＡ－ＨＥＭＡ共聚物中，Ａｒａ－Ｃ释放率随着基质中的ＭＭＡ含量增加而降低。药物的离体释放还受许多困素的控制，结果显示：药物释放量随着     

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。     

心肌显像剂~（68）Ga（BAT－TECH）的一些基本常数测定

研究了心肌显像剂￣（６８）Ｇａ（ＢＡＴ－ＴＥＣＨ）的动力学性质，测定了它的热力学常数。实验结果表明，ＢＡＴ－ＴＥＣＨ与柠檬酸镓的配体交换反应为二级反应，反应速率常数ｋ为０．５０ｌ／ｍｏｌ·ｓ，反应活化能Ｅ＿ａ＝５６．６ｋＪ／ｍｏｌ；￣（６８）Ｇａ（ＢＡＴ－ＴＥＣＨ）的稳定常数ｌｇβ＝１４．９，配体ＢＡＴ－ＴＥＣＨ的四级氢解离常数ｐＫ＿１＝４．６２，ｐＫ＿２＝７．６８，ｐＫ＿３＝８．６８，ｐＫ＿４＝１１．２。     

心肌显像剂^68Ga（BAT—TECH）的一些基本常数测定

研究了心肌显像剂＾６８Ｇａ（ＢＡＴ－ＴＥＣＨ）的动力学性质，测定了它的热力学常数。实验结果表明，ＢＡＴ－ＴＥＣＨ与柠檬酸镓的配体交换反应为二级反应，反应速率常数ｋ为０．５０ｌ／ｍｏｌ．ｓ，反应活化能Ｅａ＝５６．６ｋＪ／ｍｏｌ；＾６７Ｇａ（ＢＡＴ－ＴＥＣＨ）的稳定常数Ｉｇβ＝１４。９，配体ＢＡＴ－ＴＥＣＨ的四级氢解离常数ｐＫ１＝４．６２，ｐＫ２＝７．６８，ｐＫ３＝８．６８，ｐＫ４＝１１．２。     

NIPAAm-AAc二元线型共聚物对Er3+、UO2+2、Cr(Ⅵ)的浓集研究

利用γ辐射聚合法（总剂量３ｋＧｙ,剂量率３８．４Ｇｙ／ｍｉｎ）以ＮＩＰＡＡｍ和ＡＡｃ为单体在ＴＨＦ溶液中制备了二元线型共聚物,红外光谱证实了线型共聚物中羧基的存在;性质测定表明此共聚物具有温度敏感性,其相转变温度（ＬＣＳＴ）值随体系ｐＨ值而升高;利用这种共聚物对水溶液中微量Ｅｒ３＋、ＵＯ２＋２、Ｃｒ（Ⅵ）离子进行浓集分离研究,表明具有较好的浓集与分离效果,并对浓集机理进行了探讨     

X射线辐射对小麦幼苗生长及一些抗氧化酶活性的影响

萌发４８ｈ的小麦幼苗用Ｘ射线处理，高剂量Ｘ射线（８Ｇｙ、１４Ｇｙ）可导致小麦幼苗生长受抑制，鲜重降低，在Ｘ射线照射后第２ｄ和第４ｄ测定幼苗内蛋白质含量、抗坏血酸过氧化物酶（ＡＳＡ－ＰＯＤ）、谷胱甘肽过氧化酶（ＧＳＨ－Ｐｘ）及谷胱甘肽巯基转移酶（ＧＳＨ－Ｔｓ）活性的变化。结果可知：Ｘ射线可引起小麦幼苗内蛋白质含量的下降，１４ＧｙＸ射线照射的样品低于８Ｇｙ照射的，照射后第４ｄ的蛋白质含量高于照射后第２ｄ的，说明Ｘ射线引起的损伤可随照射后的培养而有所恢复；高剂量Ｘ射线可引起小麦幼苗内一些抗氧化酶活性的升高，且随照射剂量的增加酶活性的升高也越明显，在照射后第４ｄ幼苗的ＡＳＡ－ＰＯＤ和ＧＳＨ－Ｐｘ活性高于照射后第２ｄ的值，ＧＳＨ－Ｔｓ活性略有下降。而低剂量（２Ｇｙ）照射与对照相比，上述指标变化不大，说明Ｘ射线处理后可通过诱导这些抗氧化酶活性的升高起到减轻伤害的作用。     

EXTRACTION OF AMERICIUM AND LIGHT RARE EARTHS BY 2－ETHYL HEXYL PHOSPHONIC ACID 2－ETHYL HEXYL ESTER

ＥＸＴＲＡＣＴＩＯＮ　ＯＦ　ＡＭＥＲＩＣＩＵＭ　ＡＮＤ　ＬＩＧＨＴ　ＲＡＲＥ　ＥＡＲＴＨＳ　ＢＹ　２－ＥＴＨＹＬ　ＨＥＸＹＬ　ＰＨＯＳＰＨＯＮＩＣ　ＡＣＩＤ　２－ＥＴＨＹＬ　ＨＥＸＹＬ　ＥＳＴＥＲＺｈｕＹｏｎｇｊｕｎ（朱永）ａｎｄＪｉａｏＲｏｎｇｚｈ...     

佛波醇酯和人外周血促α照射致细胞恶性转化频率增加的研究

旨在观察佛波醇酯（ＰＭＡ）和人血多形核白细胞（ＰＭＮ）产生的氧自由基对α粒子致细胞转化频率（ＴＦ）的增加效应。Ｃ３Ｈ１０Ｔ１／２细胞经０．５、１．０和１．５Ｇｙα粒子照射后加入ＰＭＡ及ＰＭＡ刺激的人血，测定存活分数和ＴＦ，由１２５０个皿的实验所得初步结果看出，ＰＭＡ能刺激照射的Ｃ３Ｈ１０Ｔ１／２细胞增殖，并依赖于接种细胞密度和照射剂量，ＰＭＡ使０．５Ｇｙ照射的细胞ＴＦ增高２．１倍，ＰＭＡ刺激的人血增加２．８倍。     

水溶性的温度敏感性聚合物、活性共聚物的辐射合成及性质研究

研究了Ｎ－异丙基丙烯酰胺（ＮＩＰＡＡｍ）在水溶液及四氢呋喃溶液中的辐射聚合及它与活性有机单体Ｎ－丙烯酰氧基丁二酰亚胺（ＮＡＳＩ）辐射共聚，以制备水溶性、温度敏感性均聚物及共聚物。结果表明，室温、无氧条件下在水或ＰＢＳ缓冲溶液中ＮＩＰＡＡｍ及它与ＮＡＳＩ共聚物（ｐｏｌｙＮＩＰＡＡＭ－ＮＡＳＩ）辐射合成的最佳条件为：剂量１－７ｋＧｙ，剂量率不小于４０Ｇｙ／ｍｉｎ，溶液中单体浓度小于１％。单体在四氢呋喃中辐射聚合可得到粉末状固体聚合物。将这种聚合物溶于水中仍具有温度敏感性，用此法可获得较多的此类聚合物，只是分子量偏低（Ｍｎ只有１０４数量级），其合成条件与在水溶液中也有较大差异。该聚合物经热性质测定表明，多次溶解、沉淀后仍能保持其热性质的均一性和稳定性。     

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.     

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%。     

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.     

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.