Covalent binding of aflatoxin B1 to liver DNA in rats pretreated with ethanol

Summary Male Fischer F-344 rats were given ethanol in the drinking water and/or by single oral administration. Following this, the animals received p.o. 100 ng/kg of the hepatocarcinogen [³H]aflatoxin B₁ (AFB₁). 24 h later, the level of DNA-bound AFB₁ was determined in the liver and was found not to be affected by any type of ethanol pretreatment. A cocarcinogenic effect of ethanol in the liver is therefore unlikely to be due to an effect on the metabolic activation and inactivation processes governing the formation of DNA-binding AFB₁ metabolites.To whom correspondence should be addressed.Acknowledgment. We thank the European Science Foundation for the Toxicology Research Fellowship awarded to M.M.     

存在内部势Cx~n的一维无限深势阱问题的节点法

介绍用节点法求解存在内部势Ｃｘｎ的一维无限深势阱问题的物理原理，给出了该问题的数值结果，证实用节点法解决存在内部势Ｃｘｎ的一维无限深势阱问题比用变分法和微扰法的精度更高，方法更简便．     

Functions of fatty acid binding proteins

Summary Cytosolic fatty acid binding proteins (FABP) belong to a gene family of which eight members have been conclusively identified. These 14–15 kDa proteins are abundantly expressed in a highly tissue-specific manner. Although the functions of the cytosolic FABP are not clearly established, they appear to enhance the transfer of long-chain fatty acids between artificial and native lipid membranes, and also to have a stimulatory effect on a number of enzymes of fatty acid metabolism in vitro. These findings, as well as the tissue expression, ligand binding properties, ontogeny and regulation of these proteins provide a considerable body of indirect evidence supporting a broad role for the FABP in the intracellular transport and metabolism of long-chain fatty acids. The available data also support the existence of structure- and tissue-specific specialization of function among different members of the FABP gene family. Moreover, FABP may also have a possible role in the modulation of cell growth and proliferation, possibly by virtue of their affinity for ligands such as prostaglandins, leukotrienes and fatty acids, which are known to influence cell growth activity. FABP structurally unrelated to the cytosolic gene family have also been identified in the plasma membranes of several tissues (FABP_pm). These proteins have not been fully characterized to date, but strong evidence suggests that they function in the transport of long-chain fatty acids across the plasma membrane.     

芳香性的本质——π对称场效应能FE_π的研究(Ⅱ)

在［１］的工作基础上，进一步以ＦＥπ＝Ｅｄｅｌｏｃ环－∑ｉ＝１（２ｎβ－ＲＥ）Ｎｉ＋３ｎ－０．１∑πｅ－６６对辐射多烯分子，轮烯等系列分子场效应能计算；阐述“π－对称性”的普遍性。提出一新的分子结构稳定性判据△ＦπＥ，该判据也适用芳香性的判定。     

具有中心对称介质的三阶非线性偶极辐射

在经典物理框架内，把中心对称介质的偶板子运动方程化为了具有立方项的二阶非线性微分方程，用Jaeobian椭圆函数和第一类全椭圆积分给出了方程的解和电子振荡周期，并对偶极辐射进行了经典描述，给出了电子的辐射能量、瞬时辐射强度和平均辐射强度．     

综合管廊电力仓动态运维的解空间分割算法#br#

为解决综合管廊电力仓温度控制调配管理问题，有效提高其温控调配效果，提出了一种新的综合管廊电 力仓运维作业优化算法。该算法基于解空间分割原始思想，设计解空间分割处理机制，并应用其对当前综合管 廊电力运维下，不同等级电压进行测评，计算得到管廊电力仓磁场。基于电磁场数据，对自然对流微分方程、 能量方程联立求解，计算得到管廊电力运维作业的传导数据，获取电力仓温度的对接分布情况。最后对得到的 电力仓磁场计算数据和对流分析数据参数分别划分子空间，明确划分个数和空间个体数，获取最优解，实现运 维升级。实验数据证明，局部最高温度降低了将近 27%，绝对温度降低了 32%，电力仓温控调配效果显著。     

香叶木苷的血浆蛋白结合率研究

研究香叶木苷的血浆蛋白结合率．以体外方式，用平衡透析法模拟香叶木苷在大鼠体内与血浆蛋白结合的过程，并以高效液相色谱法测定香叶木苷在透析袋内血浆中的药物质量浓度与透析袋外缓冲液中的质量浓度，计算血浆蛋白结合率．香叶木苷在血浆中药物质量浓度为1～90μg／mL范围内，其与大鼠血浆蛋白的结合率范围为29．83％～32．56％，波动较小，结果可靠．香叶木苷属于低血浆蛋白结合率药物，大部分药物分子以游离形式发挥药效．     

聚丙烯纤维水泥稳定碎石断裂能试验研究

为了研究聚丙烯纤维对水泥稳定碎石断裂韧性的影响，通过对84个尺寸为100 mm × 100 mm × 515 mm的聚丙烯纤维水泥稳定碎石和普通水泥稳定碎石三点弯曲试件断裂试验，测得了试件的断裂能(GF)、裂缝嘴张开位移(CMOD)和裂缝尖端张开位移(CTOD)，并探讨了试验龄期、聚丙烯纤维体积掺量以及水泥掺量对聚丙烯纤维水泥稳定碎石断裂能的影响，对聚丙烯纤维水泥稳定碎石的经济性和施工和易性进行了简要分析，给出了聚丙烯纤维体积掺量合适的建议范围为0.6‰ ～ 0.8‰。试验结果表明：聚丙烯纤维的掺入可以明显提高水泥稳定碎石的断裂能、极限裂缝嘴张开位移(CMODmax)和极限裂缝尖端张开位移(CTODmax)；随着试验龄期的增长，无论聚丙烯纤维掺入与否，水泥稳定碎石断裂能均呈增大趋势，但聚丙烯纤维水泥稳定碎石断裂能增大的速率较大；随着纤维体积掺量的增加，水泥稳定碎石断裂能、CMODmax和CTODmax逐渐增大，尤其是当纤维体积掺量大于0.6‰时，GF增大的效果更为明显；随水泥掺量的增加，聚丙烯纤维水泥稳定碎石试件的极限荷载逐渐增加，但断裂能却逐渐减小。     

类锂离子SⅩⅣ-Ga ⅩⅢD态精细结构的计算

根据三电子原子非相对论的能级公式导出了类锂离子体系ls^23d^2D态的非相对论能量的表达式，利用变分方法计算了高离化类锂离子SXⅣ -GaⅩⅧD的非相对论能量；在此基础上，进一步利用微扰论来计算了类锂离子ls^23d^2D态的精细结构哈密顿在{LSJMJ〉表象中的矩阵元，由此得到的S XⅣ—GaⅩⅧD的精细结构分裂与实验数据符合得较好。     

人类基因组中L1元件及其5′UTR的研究

讨论了L1在人类染色体中的分布密度与染色体长度以及L1的密度与基因密度之间的关系.发现在大多数染色体上L1的密度和染色体的长度表现为正相关,而L1的密度和染色体中基因的密度表现为负相关;对人类L1的5′UTR进行了详细的研究后,发现在L1元件的5′UTR部分含有许多转录因子结合位点.对基因的转录起始位点上游进行统计分析,发现其中含有大量的L1序列.通过对人类的EST数据库进行BLAST分析,新发现了51条和人类L1 5′UTR相似性较高的EST片断,根据它们分布的组织特异性,说明L1元件可能调控与发育过程有关的基因的表达;最后应用多样性增量的方法对人类和大鼠的L1 5′UTR进行了区分,得到了较好的预测结果,说明大部分L1的5′UTR的调控作用是人类特有的.