Biodegradability of the Anti-tumour Agents 5-Fluorouracil,Cytarabine, and Gemcitabine: Impact of the Chemical Structure and Synergistic Toxicity with Hospital Effluent     

K. Kümmerer  A. Al-Ahmad 《洁净——土壤、空气、水》1997,25(4):166-172

Most anti-tumour agents are known to be carcinogenic, mutagenic, teratogenic, embryotoxic or fetotoxic. Only little is known about the environmental impact of pharmaceuticals. Unmetabolized active substances are excreted and will show up in municipal wastewater. Therefore, we examined the biodegradability of the widely used anti-tumour agent 5-fluorouracil (5-FU), also as an example for assessing the impact of hospital effluent on the biodegradation of a test compound. The biodegradability of the structurally similar anti-tumour agents cytarabine and gemcitabine was also examined. Test systems used were the closed bottle test (OECD 301 D) and the modified Zahn-Wellens test (OECD 302 B). 5-FU was not biodegradable in the closed bottle test (CBT) nor in the Zahn-Wellens test (ZWT). At the highest concentration of 5-FU, with hospital effluent an inhibition of the degradation of substances present in hospital effluent was observed, probably as a result of a synergistic effect by 5-FU with antibiotics present in hospital sewage. Gemcitabine was biodegraded 42% in the CBT. The prolongation of the test period to 40 days only improved the result to 45%. In the ZWT, the biodegradation of gemcitabine was 50%. Cytarabine was partially biodegraded in the CBT (50%), but only after an adaptation period of 20 days. After a test prolongation to 40 days, the degree of biodegradation was 80%. In the ZWT, the biodegradability was > 95% after only a few days.  相似文献   

钻孔扩底灌注桩施工新工艺   总被引：3，自引：0，他引：3  

王旭惠  何建平 《华东地质学院学报》1997,20(1):30-34

本文介绍钻孔扩底灌注桩的施工新工艺，多应式扩底钻头特点，成桩技术标准，适用范围及经济效益分析。  相似文献   

Kinetics of the Gas-Phase Reactions of OH Radicals, NO3 Radicals and O3 with Three C7-Carbonyls Formed From The Atmospheric Reactions of Myrcene, Ocimene and Terpinolene     

Jillian Baker  Janet Arey  Roger Atkinson 《Journal of Atmospheric Chemistry》2004,48(3):241-260

Rate constants for the gas-phase reactions of OH radicals, NO₃ radicals and O₃ with the C₇-carbonyl compounds 4-methylenehex-5-enal [CH₂=CHC(=CH₂)CH₂CH₂CHO], (3Z)- and (3E)-4-methylhexa-3,5-dienal [CH₂=CHC(CH₃)=CHCH₂CHO] and 4-methylcyclohex-3-en-1-one, which are products of the atmospheric degradations of myrcene, Z- and E-ocimene and terpinolene, respectively, have been measured at 296 ± 2 K and atmospheric pressure of air using relative rate methods. The rate constants obtained (in cm³ molecule^–1 s^–1 units) were: for 4-methylenehex-5-enal, (1.55 ± 0.15) × 10^–10, (4.75 ± 0.35) × 10^–13 and (1.46 ± 0.12) × 10^–17 for the OH radical, NO₃ radical and O₃ reactions, respectively; for (3Z)-4-methylhexa-3,5-dienal: (1.61 ± 0.35) × 10^–10, (2.17 ± 0.30) × 10^–12, and (4.13 ± 0.81) × 10^–17 for the OH radical, NO₃ radical and O₃ reactions, respectively; for (3E)-4-methylhexa-3,5-dienal: (2.52 ± 0.65) × 10^–10, (1.75 ± 0.27) × 10^–12, and (5.36 ± 0.28) × 10^–17 for the OH radical, NO₃ radical and O₃ reactions, respectively; and for 4-methylcyclohex-3-en-1-one: (1.10 ± 0.19) × 10^–10, (1.81 ± 0.35) × 10^–12, and (6.98 ± 0.40) × 10^–17 for the OH radical, NO₃ radical and O₃ reactions, respectively. These carbonyl compounds are all reactive in the troposphere, with daytime reaction with the OH radical and nighttime reaction with the NO₃ radical being predicted to dominate as loss processes and with estimated lifetimes of about an hour or less.  相似文献   

Composition and Assemblage Characteristics of Magnetic Minerals in Layer S_(5-1) of Xifeng and Duanjiapo Sections     

贾蓉芬  彭先芝  周正  刘德汉  王冠鑫  王德强 《中国地球化学学报》2004,23(3)

Magneticmineralsintheloess paleosolseriesaccountforabout 1 % -2 %ofthetotal (LiuTungshengandZhangZhonghu ,1 962 ) .Duetotheiraerolianorigin ,themagneticmineralsarecomplicatedincomposition ,largeingrainsizerange ,andsignificantlydifferentincrystallinity .Asaresult,researchonthesemagneticmineralswouldbesetwithalotofdifficulties.Previousre searchersemployedopticalmicroscopic ,X raydiffractionandM ssbauerspectrometrictechniquestostudythemagneticmineralsintheloess paleosolseries,andchieflyontheb…  相似文献   

工程岩体三维构模中钻孔数据处理方法   总被引：1，自引：0，他引：1  

李卫兵  刘斌  何满潮  徐能雄 《吉林大学学报(地球科学版)》2004,(Z1)

原始数据处理是工程岩体三维构模中存在的主要困难之一。从三维构模的角度,将工程岩体按几何特征抽象为4种结构单元类型。钻孔数据是描述工程岩体的重要原始数据,具有多尺度性。针对这个特点,提出钻孔数据纵向概化准则,解决工程岩体多尺度显示问题;根据地质学的地质数据解译方法,结合岩层层状分布的特点,提出层处理方法对钻孔数据进行概化处理,确定工程岩体所对应的结构单元类型,创建工程岩体结构单元三维构模数据,建立由钻孔数据所得到的工程岩体三维模型。  相似文献   

应用GMS5多通道云图估计降水技术的研究     

杨引明  姚祖庆 《气象》2004,30(11):8-13

对近两年来5～8月中国东部地区120多个测站雨量观测资料和对应4400多幅GMS-5四个通道云图的研究发现：红外亮温的时间、空间变率、红外和水汽通道亮温差等云图衍生资料对消除卷云，弥补夜间缺少可见光云图的不足起到明显作用。从而，应用双判据双重MOS多元回归法建立四通道云图因子、衍生因子与降水量之间的回归方程，进行6小时分级降水估计。为了进一步消除厚卷云和特殊地形的影响，提出使用逐日实时资料自动建立多元回归方程估计降水量，从而对双判据双重MOS多元回归法估计结果进行校正。上海中心气象台的业务使用表明，总体估计的准确率达70％左右。  相似文献   

98.7湖北特大暴雨的天气分析与降水模拟   总被引：10，自引：4，他引：10       下载免费PDF全文

齐艳军  程明虎  仪清菊 《气象》2004,30(3):12-16

1998年7月20～23日，湖北省南部发生了一次持续性特大暴雨过程，采用双向嵌套的非静力中尺度数值模式(MM5)对这次强暴雨过程进行初步模拟试验。结果表明，粗、细网格均能较好地模拟出雨带的走向和变动以及武汉地区的暴雨中心，尤其是嵌套域(细网格)模拟的降水强度比粗网格有明显改进，和实际观测结果更接近；另外，对引发这次特大暴雨的对流层低层的中尺度系统也能够很好地模拟出来。  相似文献   

2-[2-(6-氯苯并噻唑)偶氮]-5-二乙氨基苯甲酸与镍的显色反应     

樊学忠  张国防  范红杰 《岩矿测试》2004,23(1):40-43

研究了2-[2-(6-氯苯并噻唑)偶氮]-5-二乙氨基苯甲酸(6-Cl-BTAEB)与Ni2+的显色反应。结果表明:在pH4.5～7.6的HAc-NaAc缓冲溶液中及十二烷基硫酸钠存在下,试剂与Ni2+形成稳定的蓝紫色配合物,组成为n(Ni2+)∶n(6-Cl-BTAEB)=1∶2,最大吸收波长650nm,表观摩尔吸光系数为1.59×105L·mol-1·cm-1,Ni2+浓度在0～400μg/L内符合比尔定律。用铝合金和合金钢中的微量镍验证该分析方法,所得结果与推荐值相符,6次测定的RSD<2%。  相似文献   

钻孔资料管理和自动成图技术研究   总被引：12，自引：1，他引：12  

黄树桃  王树红  韩绍阳  蔡煜琦  郑恩久 《铀矿地质》2004,20(1):51-55

本文系统介绍了根据铀矿勘查生产和科研需求建立钻孔数据库的方法 ,对钻孔数据库的结构和功能进行了详细描述 ,同时也介绍了通过数据库接口对钻孔数据库进行自动成图的技术方法 ,并且在GIS平台中成功地实现了柱状图的全自动绘制和剖面图半自动绘制。该系统的建立极大地提高了生产和科研效率。  相似文献   

The analysis of SPOT-5 characteristics on land cover Classification   总被引：1，自引：0，他引：1  

徐开明 《测绘科学》2004,29(Z1):108-116

<正>KnowledgeaboutlandcoverandlandusehasbecomeincreasinglyimportantastheNationplanstoovercometheproblemsofuncontrolleddevelopment,deterioratingenvironmentalquality,lossofprimeagriculturallandsetc.Landuseandlandcoverdataareneededintheanalysisofenvironmentalprocessesandproblemstoknowiflivingconditionsandstandardsaretobeimprovedormaintainedatcurrentlevels.  相似文献