电离辐射与活性氧诱发人淋巴细胞姊妹染色单体交换与抑…

电离辐射、超氧阴离子自由基和羟自由基都能分别引起人淋巴细胞姊妹染色单交换（ＳＣＥ）频率增加和细胞增殖率指数降低。ＳＣＥ与增殖率指数间密切负相关。推测电离辐射的上述生物学效应正是由辐照细胞生成的超氧阴离子和羟自由基引起的。     

苯酚类螯合剂清除氧自由基及抗辐射脂质过氧化作用的研究

报道了单分子和双分子取代苯酚类螯合剂对超氧阴离子自由基和羟自由基的清除作用及对大鼠肝线粒体辐射诱导的脂质过氧化反应的抑制作用。结果表明取代苯酚类螯合剂具有不同程度的清除氧自由基和抗辐射脂质过氧化作用,其清除羟自由基和抑制辐射诱导的脂质过氧化作用的IC     

琥珀酸-氨基葡糖-二价铜络合物清除超氧阴离子自由基的研究

在核黄素水溶液反应体系中,以甲硫氨酸和超氧化物歧化酶为竞争清除剂[1-3],测定了琥珀酸-氨基葡糖-二价铜络合物(Amberacid-chitosan-complexwithcopper(II),ACCC)清除超氧阴离子自由基的反应速率常数。使用254、365nm的紫外光和太阳光为光照源,分别测得清除超氧阴离子自由基的反应速率常数为1.26×109、1.11×109、4.98×108mol-1s-1dm3。本研究还表明,琥珀酸-氨基葡糖-二价铜络合物清除超氧阴离子自由基的效率分别达91%,这与超氧化物歧化酶的清除效率(93%)几乎相同,但远高于用琥珀酸清除超氧阴离子自由基的效率(2.6%)或用氨基葡糖清除…     

电离辐射对人皮肤成纤维细胞中超氧阴离子自由基浓度和超氧化物歧化酶与组织蛋白酶D活力的影响

６０Ｃｏγ射线１０～４０Ｇｙ照射正常人皮肤成纤维细胞，１ｈ后，细胞释放超氧阴离子自由基（Ｏ２）量显著增高，其增高与照射剂量呈正相关。细胞超氧化物歧化酶（ＳＯＤ）活力明显下降，且与照射剂量呈负相关。组织蛋白酶Ｄ活力显著增高，其增高与照射剂量呈正相关。在辐照０～４０Ｇｙ范围内，细胞释放Ｏ２量与细胞ＳＯＤ活力是负相关，而细胞释放Ｏ２量与细胞组织蛋白酶Ｄ活力呈正相关。     

α2M对辐射引起细胞自由基变化的影响

采用６０Ｃｏγ射线照射人皮肤成纤维细胞，并在照射前、后给予不同剂量的甲２巨球蛋白（α２Ｍ），用细胞色素Ｃ法、ＴＢＡ法及邻苯二酚自氧化法分别测定细胞超氧阴离子自由基（Ｏ２）释放、脂质过氧化（ＬＰＯ）水平及超氧化物歧化酶（ＳＯＤ）活力。发现细胞受照后Ｏ２释放和ＬＰＯ水平显著增高（ｐ＜０，０１）；Ｏ２释放与照射剂量呈正相关（ｒ＝０．９６６，Ｐ＜０．０１），ＳＯＤ活力显著下降（Ｐ＜０．０１），且与照射剂量呈负相关（γ＝０．９６６，Ｐ＜０．０１）。照射后给予α２Ｍ能显著抑制Ｏ２释放（Ｐ＜０．０１）、降低ＬＰＯ水平。     

羟基肉桂酸衍生物清除超氧阴离子自由基研究

采用脉冲辐解技术，利用竞争动力学方法测定了中性条件下３种羟基肉桂酸衍生物（咖啡酸、阿魏酸和芥子酸）与超氧阴离子自由基的反应速率常数，结合稳态分析，探讨了相应的反应机理。     

木材^60Coγ射线引发自由基的衰变系数

木材经￣（６０）Ｃｏγ射线辐照后，高聚物分子的共价键断裂而产生自由基。福建２１个树种木屑试样经辐照后，用ＥＳＲ测试，主谱ｇ＿０＝２．０１９３的自由基均随剂量Ｄ按指数率变化，最后趋于饱和。α＿ａ与树种有关，但均远小于１。增加木材表面自由基，可以显著提高木材的胶合强度。木材经γ射线辐照后引发的自由基强度大，衰变系数小，稳定性好，具有应用前景。     

嘧啶碱自由基的INDO计算Ⅳ 胸腺嘧啶离子及抽氢自由基产物的结构

胸腺嘧啶离子及抽氢自由基产物的自旋密度分布及超精细偶合常数的理论值已用INDO法进行了计算,其构型的原子坐标遵循“混合几何模型”。胸腺嘧啶阴离子自由基和甲基抽氢自由基的超精细偶合常数理论值与实验值符合得很好。而阳离子自由基及N1抽氢自由基,我们的计算值与其他作者的计算值一致,与实验值近似地符合。     

离子束注入抗生素产生菌的ESR研究

用ＥＳＲ波说仪测定了室温下氮离子注入核糖霉素产生菌、卡那霉素产生菌和卡那霉素抗株产生菌所引起的自由基。实验结果表明，氮离子注入上述三种菌种能产生大量的自由基，自由基产额随注入剂量的增加而增加。菌种死亡率随自由基产额的增加而上升。     

羟基肉桂酸衍生物对组蛋白H3辐射保护的ESR研究

应用ＥＳＲ波谱模拟解析法，研究了７７Ｋγ辐射引发羟基肉桂酸衍生物与组蛋白Ｈ３的二元分子复合体系的两组分的电子转移过程。在解析二元复合体系ＥＳＲ波谱的基础 ，计算了二元分子复合体系两组分摩尔比不同的一系列复合体系的自旋转移比Ｒｓｃ。研究发现Ｒｓｃ与复合体系的摩尔比呈良好的线性关系，这表明羟基肉桂酸衍生物具有较强的夺取蛋白质这酰胺羰基阴离子自由基电子和修复蛋白质辐射损伤的能力，这与用羟基肉桂酸衍生物通     

Activated persulfate by DBD plasma and activated carbon for the degradation of acid orange Ⅱ

In this study, the effect of activated peroxydisulfate(PDS) by dielectric barrier discharge(DBD) plasma and activated carbon(HGAC) on the removal of acid orange Ⅱ(AOⅡ) was investigated. The effects of applied voltage, PDS dosage, HGAC dosage, initial pH value, and inorganic anions on the removal rate of AOⅡ were discussed. The main free radicals degrading azo dyes during the experiment were also studied. Experimental results show that the removal rate of AOⅡ in DBD/HGAC/PDS synergistic system is much higher than that in the single system. With the applied voltage of 16 kV, HGAC dosage of 1 g l-1, PDS and AOⅡ molar ratio of 200:1, initial pH value of 5.4 and concentration of AOⅡ solution of 20 mg l-1, the removal rate of AOⅡ reached 97.6% in DBD/HGAC/PDS process after 28 min of reaction.Acidic and neutral conditions are beneficial for AOⅡ removal. Sulfate and hydroxyl radicals play an important role in the removal of AOⅡ. Inorganic anions are not conducive to the removal of AOⅡ.     

Strengthening decomposition of oxytetracycline in DBD plasma coupling with Fe-Mn oxide-loaded granular activated carbon

A catalytic approach using a synthesized iron and manganese oxide-supported granular activated carbon (Fe-Mn GAC) under a dielectric barrier discharge (DBD) plasma was investigated to enhance the degradation of oxytetracycline (OTC) in water. The prepared Fe-Mn GAC was characterized by x-ray diffraction and scanning electron microscopy, and the results showed that the bimetallic oxides had been successfully spread on the GAC surface. The experimental results showed that the DBD + Fe-Mn GAC exhibited better OTC removal efficiency than the sole DBD and DBD + virgin GAC systems. Increasing the fabricated catalyst and discharge voltage was favorable to the antibiotic elimination and energy yield in the hybrid process. The coupling process could be elucidated by the ozone decomposition after Fe-Mn GAC addition, and highly hydroxyl and superoxide radicals both play significant roles in the decontamination. The main intermediate products were identified by HPLC-MS to study the mechanism in the collaborative system.     

丹参制剂改善辐射硫化胶膜抗老化性能及其作用机制的研究

研究了丹参制剂对天然橡胶乳液辐射硫化（RVNRL）胶膜抗老化性能的影响及其作用机制。结果表明，在近选择的中草药制剂中，丹参制剂有较好抗老化性能；而在3种流分的丹参制剂中，酒沉前丹参制剂的抗老化性能最佳；对于SM-a(c-99)制剂来讲，1.5g丹参生药/20gRVNRL的加入量是适宜的；而不同产地的丹参制剂的抗老化性能也会有所不同；丹参制剂的抗老化性能与其清除羟自由基能力相一致。     

兰州城区某地自然降尘特性及其变化规律

用仪器中子活化法分析了１９９３年９月至１９９４年８月间兰州城区自然降尘中３２种元素的浓度，用离子色谱法测定了７种水溶性阴离子的浓度，计算了元素的富集因子。初步探明了降尘的化学组成及其中元素、水溶性离子的分布和变化规律。     

大剂量X射线照射对雄性大鼠某些组织LPO水平及CuZn－SOD和Se－GSH－Px活性的影响

本研究观察大剂量Ｘ射线照射雄性大鼠７２ｈ后免疫和内分泌等组织脂质过氧化物（ＬＰＯ）水平及超氧化物歧化酶（ＣｕＺｎ－ＳＯＤ）和谷胱甘肽过氧化物酶（Ｓｅ－ＧＳＨ－Ｐｘ）活性的变化。结果发现，胸腺、脾脏、肾上腺和肝脏ＬＰＯ水平随照射剂量的增加而增高；脾脏和肝脏ＣｕＺｎ－ＳＯＤ活性在４Ｇｙ以上剂量照射后即升高，但在１０Ｇｙ照后增高明显；胸腺和脾脏Ｓｅ－ＧＳＨ－Ｐｘ活性在４Ｇｙ以上剂量照射后即明显高于对照组，睾丸Ｓｅ－ＧＳＨ－Ｐｘ活性也有增高趋势，其中１０Ｇｙ组增高明显；但是，４Ｇｙ以上剂量照射后胸腺ＣｕＺｎ－ＳＯＤ和肾上腺Ｓｅ－ＧＳＨ－Ｐｘ活性降低     

Photochemical Reactions of Uranium(VI) in Aqueous Phosphoric Acid Solutions

Photochemical reactions of U(VI) ion with halogen and pseudohalogen anions. I^?, Br^?, Cl^? and NCS^?, were studied in aqueous phosphoric acid solutions under irradiation of nitrogen laser. The formation of U(IV) was observed in the reactions with I^?, Br^? and NCS^?, but not with CI^?. The yield of U(IV) increased in the order Br^?<NCS^?<I^?. This order was the same as the quenching rate constants of the excited U (VI) ion with these anions, but the reverse of their standard redox potentials. These facts are consistent with the electron transfer mechanism between excited U (VI) and these anions. The rates of the formation of U (IV) in the presence of Br^? were measured by the spectrophotometric method. It was found that the rate equation was first order in both U (VI) and Br^?. The results were reasonably interpreted by a series of reaction processes involving U(V) and Br radical. The photo-oxidation of tris(1, 10-phenanthroline)-Fe (II) ion by U (VI) was also studied in the same procedures. Based on the rate law, we proposed a one-electron transfer mechanism involving U(V) as an intermediate.     

H2O2活化蒙脱石对溶液中U(Ⅵ)的吸附

利用H₂O₂对蒙脱石进行活化，获得了活化蒙脱石吸附材料(A_X-MMT)，采用X射线衍射(XRD)、傅里叶红外谱图(FTIR)、透射电镜(TEM)、扫描电镜(SEM)、比表面分析(BET)、表面Zeta电位分析等手段对活化样品进行了表征；采用静态批量实验法，考察了H₂O₂浓度、pH值、接触时间和共存阴阳离子对U(Ⅵ)在A_X-MMT上吸附率的影响。结果表明：活化保留了蒙脱石基础结构，其阳离子交换容量(CEC)有所减少，但层间距、比表面积、孔隙体积、表面酸位点和表面Zeta电位均有明显提升，对溶液中U(Ⅵ)的吸附性能显著增强；在最佳活性和吸附条件下(H₂O₂质量分数、pH值和接触时间分别为10%、6和24 h)，蒙脱石对U(Ⅵ)的吸附性能提升了8.5倍，吸附行为符合准二级吸附动力学模型；在共存阴阳离子的干扰下，H₂O₂活化蒙脱石能对U(Ⅵ)展现良好的吸附性能。     

H 2 O2活化蒙脱石对溶液中U(Ⅵ)的吸附

利用H₂O₂对蒙脱石进行活化,获得了活化蒙脱石吸附材料(A_X-MMT),采用X射线衍射(XRD)、傅里叶红外谱图(FTIR)、透射电镜(TEM)、扫描电镜(SEM)、比表面分析(BET)、表面Zeta电位分析等手段对活化样品进行了表征;采用静态批量实验法,考察了H₂O₂浓度、pH值、接触时间和共存阴阳离子对U(Ⅵ)在A_X-MMT上吸附率的影响。结果表明：活化保留了蒙脱石基础结构,其阳离子交换容量(CEC)有所减少,但层间距、比表面积、孔隙体积、表面酸位点和表面Zeta电位均有明显提升,对溶液中U(Ⅵ)的吸附性能显著增强;在最佳活性和吸附条件下(H₂O₂质量分数、pH值和接触时间分别为10%、6和24 h),蒙脱石对U(Ⅵ)的吸附性能提升了8.5倍,吸附行为符合准二级吸附动力学模型;在共存阴阳离子的干扰下,H₂O₂活化蒙脱石能对U(Ⅵ)展现良好的吸附性能。     

Surface treatment of titanium dioxide nanopowder using rotary electrode dielectric barrier discharge reactor

Titanium dioxide (TiO2) nanopowder (P-25;Degussa AG) was treated using dielectric barrier discharge (DBD) in a rotary electrode DBD (RE-DBD) reactor.Its electrical and optical characteristics were investigated during RE-DBD generation.The treated TiO2 nanopowder properties and structures were analyzed using x-ray diffraction (XRD) and Fourier-transform infrared spectroscopy (FTIR).After RE-DBD treatment,XRD measurements indicated that the anatase peak theta positions shifted from 25.3° to 25.1°,which can be attributed to the substitution of new functional groups in the TiO2 lattice.The FTIR results show that hydroxyl groups (OH) at 3400 cm-1 increased considerably.The mechanism used to modify the TiO2 nanopowder surface by air DBD treatment was confirmed from optical emission spectrum measurements.Reactive species,such as OH radical,ozone and atomic oxygen can play key roles in hydroxyl formation on the TiO2 nanopowder surface.