重离子束治癌相关生物学效应及机理研究

重离子束治癌是当今放射治疗中最科学、最先进、最有效的方法，是有代表性的高技术。目前仅有美、日、德实现了该技术，并已取得常规疗法难以实现的疗效。我国近年来开展了“重离子束治癌技术的基础研究”，其中，放射生物学及机理研究是重要内容。本论文从细胞、DNA分子、以及动物个体的三个不同层次上分别研究了重离子束治癌相关的生物学问题。在细胞研究方面。采用HeLa、B 16两种细胞分别研究了X一射线和重离子在水介质中入射的深度与相应细胞的存活率(1一失活率)，结果表明：X一射线对细胞的损伤随深度而逐渐衰减(或细胞存活随深度逐渐增加)，而重离子对细胞的损伤则为Bragg曲线(或细胞存活为倒Bragg曲线)。研究了25MeV／u ~(40)Ar~(14+)辐照人肝癌细胞SMMC一7721的微核及存活的动态变化，结果表明： 单次照射与分次照射的微核率随时间的变化规律在96h内没有明显区别，受照(单次、分次) 肝癌细胞的存活数随时间表现出衰减趋势，微核率与细胞存活数关系的动态变化为负相关性。研究了6MV X-射线和125．5keV／μm的重离子辐照B 1 6、V79细胞的2Gy存活率(SF2)，结果表明：B16和V79细胞的存活率(P<0．01)依赖于不同的辐射性质(X-射线、~(12)C离子)，其X-射线与~(12)C离子辐射这两种细胞的存活率之比分别为5．4和1．43，即~(12)C离子辐射增强了X-射线抗性细胞系的敏感性，从而显示了重离子治疗癌症的优势。研究了125．5keV／um的碳离子辐照小鼠黑色素瘤B16、人的宫颈癌HeLa、中国仓鼠肺V79、人的肝癌SMMC-7721四种细胞的相对生物学效率(RBE)，得．到了RBE依赖于细胞种类的关系、RBE随细胞存活水平的升高而增加的关系、以及当LET≥125．5keV／μm时，RBE随着LET的增大而变小的关系。在DNA分子研究方面。研究了125．5keV／μm~(12)C~(6+)辐照小鼠黑色素瘤B 16、中国仓鼠肺V79、人的宫颈癌HeLa、人的肝癌SMMC一7721细胞的灵敏度(由D50表示)、DNA双链断裂(DSB)和DNA双链断裂片段分布，结果表明：细胞敏感性与DNA双链断裂之间没有一致的关系，提出了细胞辐射敏感性的一种可能的分子机理，即DNA序列敏感性位点协同DNA双链断裂互补性机理。由此解释了四种细胞系的不同敏感性问题。在动物个体研究方面。研究了57．28MeV／u氧离子50Gy一次性局部照射对B16黑色素瘤小鼠肿瘤生长的抑制作用，并观测了受照小鼠的死亡情况，结果表明：照射B16黑色素瘤后第10天观察，肿瘤生长延迟为6天、肿瘤抑制率为66％，耐受剂量小于50Gy。研究了50MeV／u ~(12)C~(6+)离子辐照对小鼠移植性肿瘤S180的抑制作用、控制率、治愈率和病理组织学变化，结果表明：各剂量组对S180肉瘤的抑制作用均大于90％，高剂量组抑瘤作用明显强于低、中剂量组(P

FEBIAD-II离子源少参数质量公式和核质量计算

第一篇FEBIAD－II离子源根据物理实验的要求本文设计和加工了一套有别于中空阴极源的FEBIAD－II离子源系统，在文中对离子源结构和特点进行了分析。测试了离子源引出离子束的发散情况，得到了此离子源的工作温度，引出离子流与高压、引出板电压、网栅电流的关系曲线，进而给出本源的工作参数。第二篇少参数质量公式和核质量计算本文介绍一个少参数的原子核质量公式，并计算了28≤Z≤81的1440个原子核质量和S_(2n)，与实验比较，核质量和S_(2n)的方均根偏差分别为1.01和0.57MeV。计算的双中子分离能曲线很好地重现了N＝50、82的主壳效应，Z＝40时N＝56的亚壳效应，以及N≥60和90时的原子核发生大形变的特性

Study on bioactivity of extracts from marine sponges in Chinese Sea

The bioactivity screening of fractions from two inter-tidal sponges collected from the north of China Yellow Sea and one sponge collected from the South Chinese Sea was reported in this study. In sponge Hymeniacidon perleve there were 9 fractions out of 15 from CHCl3 extract with anti Staphylococcus aureus activity, 9 fractions out of 19 from BuOH extract with anti Escherichia coli activity, and three fractions from CHCl3 extract which had moderate to strong activity in inhibiting Bacillus subtilis, Candida albicans, and Aspergilus niger. The fractions of Reniochalina sp. showed bioactivity against bacteria and fungi. The fractions of Acanthella acuta Schmidt showed bioactivity against S. aureus and fungi. One compound from H. perleve obtained by the bioactively directing isolation was tested for bioactivity against the human hepatoma cell line Qgy7701 (IC50 10.1 mug/ml), Burkitt's lymphoma cell line Raji (IC50 9.76 mug/ml) and chronic myelogenous leukemia K562 (IC50 1.90 mug/ml). (C) 2003 Elsevier B.V. All rights reserved.

Analysis of sulfur-containing compounds in crude oils by comprehensive two-dimensional gas chromatography with sulfur chemiluminescence detection

This paper reports an analytical method for separating, identifying, and quantifying sulfur-containing compounds in crude oil fraction (IBP-360degreesC) samples based on comprehensive two-dimensional gas chromatography coupled with a sulfur chemiluminescence detector. Various sulfur-containing compounds and their groups were analyzed with one direct injection. 3620 peaks were detected including 1722 thiols/thioethers/ disulfides/1-ring thiophenes, 953 benzothiophenes, 704 dibenzothiophenes, and 241 benzonaphthothiophenes. The target sulfur compounds and their groups were identified based on the group separation feature and structured retention of comprehensive two-dimensional gas chromatography as well as standard substances. The quantitative analysis of major sulfur-containing compounds and total sulfur was based on the linear response of the sulfur chemiluminescence detector using the internal standard method. The sulfur contents of target sulfur compounds and their groups in 4 crude oil fractions were also determined. The recoveries for standard sulfur-containing compounds were in the range of 90-102%. The quantitative result of total sulfur in the Oman crude oil fraction sample was compared with those from ASTM D 4294 standard method (total S by X-ray fluorescence spectrometry), the relative deviation (RD%) was 4.2% and the precision of the method satisfactory.

Sn-modified Pt/SAPO-11 catalysts for selective hydroisomerization of n-paraffins

The hydroconversion of n-paraffins is a key reaction in hydrodewaxing of lubricating base oil. In this paper, we investigate the performance of Pt/SAPO-11 catalysts for isomerization of n-paraffins by the model compound of n-dodecane. Under this experimental condition, yields of feed isomers as well as cracking products are a function of the total n-dodecane conversion. Primary products are methylundecane while multi-brancheds and cracking products are formed in successive reactions. The result shows that the addition of Sn increases the selectivity for isomerization reaction. The most ideal experimental data for hydroconversion of n-dodecane is that the selectivity of isomerized products gets 90% when conversion of n-dodecane is 90% for the Sn-promoted Pt/SAPO-11 catalyst.

A study of shear viscosity of interfacial films containing alkyl metal phosphates

Experimental data are presented to show the influence of alkyl metal phosphates, Shengli resin fraction, and NaCl, on the shear viscosity of interfacial films and the stability of emulsions. It was found that the alkyl metal phosphates and the Shengli resin fraction could enhance the shear viscosity of interfacial films and the stability of emulsions. NaCl (0.01-0.03 mol L-1) could change the shear viscosity of interfacial films containing alkyl metal phosphates and the Shengli resin fraction. The shear viscosity of interfacial films containing ethyl iron phosphate and the Shengli resin fraction decreased with the increase of the concentration of NaCl. On the other hand, NaCl could decrease the stability of the emulsions. (C) 2004 Elsevier B.V. All rights reserved.

长白山二道白河森林流域河岸带阔叶红松林最小面积与a多样性(英文)

河岸带是森林小流域单元的重要组成部分之一。由于河水的影响和边缘效应等因素的综合作用,河岸带植物群落与远离河岸带的森林群落在组成、结构和分布格局等方面存在较大差异,其群落最小面积也不同。本文对长白山原始阔叶红松林河岸带植物群落最小面积和物种丰富度进行了探讨。结果表明河岸带植物群落的最小面积均小于森林内部植物群落的最小面积。对于长白山原始阔叶红松林群落而言,在河岸带,包括群落的60%、80%、90%植物种类时的平均最小面积分别为80m2、180m2和320m2左右;;对应于远离河岸带的森林内部,包括群落的60%、80%、90%植物种类时的平均最小面积分别为260m2、380m2和480m2左右。河岸带植物群落的物种丰富度、均匀度和Shannon-Wiener指数普遍高于森林内部植物群落,但优势度则相反。表4参20。

臭氧浓度升高对银杏光合作用的影响

在臭氧浓度升高条件下,采用开顶箱(OTC)方法研究了臭氧浓度升高对沈阳市主要绿化树种银杏光合生理特性的影响。结果表明,与对照相比,高浓度(80±8nmol.mol-1)臭氧处理下,银杏叶片净光合速率显著降低。处理50d时,降低幅度为33.90%(P<0.01),类胡萝卜素含量显著增加(P<0.05);叶绿素a、叶绿素b与叶绿素(a+b)含量变化复杂,叶绿素a/b值则先降低后升高;可溶性糖含量无明显变化,而淀粉含量则随着处理时间的延长显著降低;可溶性蛋白含量低于对照,并随着处理时间延长下降幅度增大;叶片中丙二醛含量随着处理时间显著增加。处理80d时,丙二醛含量增加了79.53%。光合作用的下降与叶绿素的变化无关,主要与膜脂过氧化有关。光合作用的下降导致了可溶性蛋白质和淀粉的减少,并最终导致生长缓慢。

当前我国植物资源利用研究中几个问题的探讨

在总结我国３０余年植物资源开发利用成果的基础上，论述该领域研究的深远意义和广阔前景；探讨研究对象与范围、多学科基础与合作；介绍了寻找新植物药源的途径；提出值得注意的问题与课题。为我国植物资源的开发利用研究提供某些借鉴和参考。

东北黑土土壤磷的纬向分异

以中国东北的中纬度黑土区为样带,研究了有机磷浓度与有机质、全氮浓度的关系;全磷、有机磷、无机磷及有机磷和无机磷的比率与纬度分布的关系。结果表明,有机磷和有机质、全氮浓度具有良好的相关性,它们之间的相关系数分别为0.90和0.92,呈极显著正相关(P<0.01)。全磷、有机磷、无机磷、Po/Pi在纬度上都存在不同程度的分异规律,即随着纬度的升高,其浓度或比率均有逐渐升高的趋势;其相关系数分别为0.68、0.77、0.26和0.60,相关分析表明,这些纬向分异规律都达极显著水平(P<0.01)。除了无机磷的纬向分异原因尚不明确之外,其他纬向分异的原因可能是由于黑土南北样带气候热量上的差异和人类活动的影响所致,从而造成南北样带之间有机质的矿化程度和速率产生差异。

Shape selectivity in methane dehydroaromatization over Mo/MCM-22 catalysts during a lifetime experiment

Dehydroaromatization of CH4 with 2% CO2 on 6Mo/MCM-22 in a 100-h lifetime test was carried out at 993 K, atmospheric pressure and 1500 mL/gh. The duration of the lifetime test can be divided into an induction stage, stable stage and deactivation stage on the basis of the selectivities of hydrocarbons and coke. The characteristics of deposited coke with different time onstream were studied using TPO and TG techniques. There were two peaks corresponding to two kinds of coke recorded in TPO profiles, and the oxidation temperature of coke shifted to higher values with less hydrogen content with the increase of coke deposits. BET and Benzene-TPD techniques were employed to study the variation of specific surface area of the external and micropore surface versus time onstream. With the accumulation of coke deposits, although the pores became partially blocked and the internal surface decreased, methane could still enter the channel and was converted to benzene with shape selectivity until a critical value of coke deposition was reached.

复合潜流人工湿地处理城市地表径流研究

以武汉市桃花岛塘和复合潜流人工湿地组合生态处理系统为研究对象,考察了对城市地表径流的处理效果。结果表明,塘和复合潜流人工湿地组合生态系统可以有效净化城市地表径流,对各污染物的去除率:COD为84.0%~85.4%、TP为89.6%~91.8%、TN为92.2%~94.4%、SS为95.8%~97.1%,其中复合潜流人工湿地对COD、TP、TN、SS的去除率分别为69.0%~73.1%、82.6%~86.6%、89.0%~90.4%、64.7%~69.2%,除氮效果独特。在无雨期该生态系统可用于净化湖水,实现了削减污染和保持系统稳定的双重功能,同时还可补给养鱼塘用水。

镉胁迫对金银花生理生态特征的影响

采用水培试验方法,研究了不同浓度镉(Cd)(0、5、10、25和50mg·L-1)胁迫条件下藤本植物金银花的生长和生理特性.结果表明:与对照相比,Cd胁迫对金银花的生长未造成明显影响,在5～50mg·L-1Cd处理下,其生物量无明显差异(P>0.05),在低浓度Cd(5mg·L-1)处理下生物量有所增加,叶、根生物量和总生物量分别增加了2.88%、2.33%和1.25%,说明金银花对Cd具有较强的抗性.在低浓度Cd胁迫下,植物各器官的含水量和可溶性蛋白含量均有所降低,而根系和叶片的丙二醛含量分别增加51.90%和23.07%,叶绿素和类胡萝卜素含量则增加15.87%和24.89%,超氧化物歧化酶活性也显著增强.随着Cd浓度的增高,金银花体内的叶绿素和类胡萝卜素含量,以及超氧化物歧化酶活性均有所降低.

旱农区不同种植模式作物最佳补灌时期和适宜补灌量研究

对不同种植模式作物进行补灌的产量及水分效应研究表明 ,在自然降雨基础上补灌 45 mm和 90 mm水 ,各种植模式的产量及水分利用效率均较对照大幅度提高。初步确定出在作物生长前期降雨较多的丰水年 ,三种种植模式的适宜补灌定额为 90 mm。三种种植模式中作物的最佳补灌时期及适宜补灌量分别为 :单作小麦播前沟灌 8mm,孕穗期补灌 82mm;单作地膜玉米在大喇叭口期一次补灌 90 mm;带田小麦播前沟灌 4mm,拔节期和孕穗期各补灌 19mm,带田地膜玉米在拔节期和大喇叭口期各补灌 2 4 mm。该结论适宜于北方旱地农田推广应用。