Theoretical and Experimental Study on Fluorescent Static Quenching of Organic Micromolecule Fluorescence Probe by Macrobiological Molecule

现有的荧光猝灭理论的应用混淆了猝灭剂的平衡浓度[Q]与初始浓度[Q]0之间的关系.基于这一问题,本文探讨了生物大分子与有机物小分子探针之间相互作用的静态荧光猝灭理论,推导了相关的表观结合常数K和结合位点数n的数学表达式,及其相关的定量测定关系式.推导结果表明,荧光体的荧光强度与荧光体和猝灭剂之间的相对浓度有直接的关系,在猝灭剂的初始浓度[Q]0远小于荧光体的初始浓度[P]0时,?F与猝灭剂初始浓度[Q]0在一定浓度范围内呈正比;而在猝灭剂的初始浓度[Q]0远大于荧光体的初始浓度[P]0时,lg1F与lg[Q]0呈正比.本文对上述推导结果进行了实验验证,结果表明,理论推导与实验结果相符,克服了现有的荧光猝灭理论存在的不足,不仅建立了静态荧光猝灭法测定生物大分子的更加科学的方法,而且对研究生物大分子与小分子荧光探针之间的相互作用具有一定的指导作用.The initial concentration and equilibrium concentration are usually confused in the application of existing theories of fluorescent static quenching.So in this article,the theory of fluorescent static quenching by the formation of compound of organic micromolecule with macrobiological molecule was studied.The relationship concerning the apparent formation constant K and the reacting locus number n are deduced and discussed,and the formulas of the quantitative determination are also deduced and proved by experiments.The deduced result as follows,⊿F is proportional to the initial concentration of quencher when the initial concentration of quencher is far less than the initial concentration of fluorescence probe,and lg1F is proportional to lg[Q]_0 when the initial concentration of quencher is far higher than the initial concentration of fluorescence probe.The experiment results proved that the theoretical results deduced in this paper are working.To some extent,these theoretical and experimental results overcome the disadvantages of the existing theoretical and experimental results.So these results not only establish a scientific method of quantitative determination,which can really describe the fluorescent static quenching,but also have instructions for the study on the action between micromolecule fluorescence probes and macrobiological molecules

基于温室气体排放的云南香格里拉旅游线路产品生态效率

生态效率反映了人们对于经济和生态问题的双重思考,要求整个社会在经济发展的同时力求环境影响最小。温室气体排放已成为全球环境关注的焦点,如何量化旅游活动所产生的温室气体排放也是旅游环境影响研究的难点。以旅游产品为对象,选用旅游者支出和旅游活动CO2-e排放量作为生态效率的指标,构建了旅游线路产品生态效率的计算模型。以云南旅游市场最具代表性的香格里拉"八日游"系列产品为例,对其生态效率进行计算和分析。结果表明:①旅游业内部,各个部门、各种产品之间的生态效率存在很大的差别。②交通、餐饮是影响旅游线路产品生态效率的关键因素。③影响旅游线路产品生态效率的因素主要来自经济量和排放量两个方面。影响经济量的主要因素是包价部分价格和自费部分的花销。影响排放量的主要因素是交通、产品结构以及能源类型。从产品角度讨论生态效率,有利于旅游者和旅游从业者加深对生态效率的理解,促进其生态意识的提高

Study on the Fluorescein SaFranine T Energy TransFer Systems and Its Application as A Fluorescent Probe For Nucleic Acid

研究了以能量转移作为核酸荧光探针的可能性，提出利用能量转移体系测定dnA的新方法.该方法灵敏、快速，重现性好，dnA测定的线性范围是0.05~10Mg/l，检测限为0.047Mg/lCTdnA（n＝11）.The possibility of energy transFer between FL and ST systems as a Fluorescent probe For deoxyribonucleic acid was investigated, and based on the energy transFer systems a novel Fluorescence method For the determination of double strands DNA has been presented.This method is sensitive, rapid and reproducible.Linearity is observed in the range 0.05 ～ 10 mg/L CT DNA, the limit of detection is 0.047 mg/L CT DNA ( n =11).国家自然科学基

Research on the antioxidant capacity of Parabarium micranthum extracted by different ethanol concentrations and its antioxidant mechanism on HaCaT cells

目的本研究对红杜仲不同乙醇浓度提取物抑制H_2O_2诱导的HaCaT细胞氧化应激损伤作用进行筛选。方法以不同浓度乙醇进行回流提取分别获得了30%、50%、70%及95%乙醇提取的四种红杜仲醇提取物(Parabarium micranthum ethanol extract,PEE),利用1,1-二苯基-2-三硝基苯肼(1,1-Diphenyl-2-picrylhydrazyl radical 2,2-Diphenyl-1-(2,4,6-trinitrophenyl)hydrazyl,DPPH)法测定其体外清除自由基的能力。以人永生化表皮细胞HaCaT为研究对象,通过不同浓度H_2O_2处理细胞并筛选以200μmol/L作为建立H_2O_2诱导的氧化应激损伤模型的最适浓度。设立对照组、H_2O_2损伤组和红杜仲-H_2O_2组。通过微板法和比色法测定内源性抗氧化酶活力及细胞存活率,2',7'-二氯荧光黄双乙酸盐(2,7-dichlorodihydrofluorescein diacetate,DCFH-DA)荧光探针检测细胞内氧自由基(reactive oxygen species,ROS)水平,逆转录PCR测定Nrf2 mRNA表达量。结果不同乙醇浓度提取的PEE在体外均具有清除DPPH自由基的作用,效果最强的70%乙醇提取的PEE的IC(50)为7.6 mg/L;在细胞水平上,H_2O_2诱导使得HaCaT细胞内抗氧化酶SOD及CAT活力降低,50%、70%及95%乙醇提取的PEE能够显著提高细胞内抗氧化酶活力。其中70%乙醇提取的PEE的作用最为显著,抗氧化酶活力的提高表现出剂量依赖性,并且能显著提高细胞存活率、降低细胞内ROS的水平(与氧化应激组比,P<0.05或P<0.01)。同时,70%乙醇提取的PEE能够显著诱导抗氧化相关信号通路基因Nrf2 mRNA的表达。结论 70%乙醇提取的PEE可能通过激活Nrf2抗氧化信号通路,提高抗氧化酶活性,降低ROS水平,从而具有保护HaCaT细胞免受H_2O_2诱导的氧化损伤作用。Objective The aim of this research was to screen the antioxidant capacity of Parabarium micranthum extract of various ethanol concentrations against H_2O_2-induced oxidative stress in Ha Ca T cells. Methods Parabarium micranthum extracts reflux purified with 30%,50%,70% and 95% ethanol( PEE) were objected to screening for their free radical scavenging capacities in vitro by DPPH. Cultured Ha Ca T human keratinocytes were randomly assigned to control,H_2O_2 and PEE + H_2O_2 groups. The cultured Ha Ca T cells were treated with different concentrations of H_2O_2 and 200μmol /L H_2O_2 was selected to establish H_2O_2-induced oxidative stress model. For the PEE + H_2O_2 group,the cells were treated with PEE extracts of various ethanol concentrations before exposure to H_2O_2. Endogenous antioxidant enzyme activity and cell viability were detected by microplate assay and colorimetric method. Intracellular reactive oxygen species( ROS) were detected by DCFH-DA fluorescent probe. Nrf2 mRNA expression was evaluated by reverse transcription PCR. Results All PEE extracts of various ethanol concentrations showed effective DPPH free radical scavenging capacities of which the 70% ethanol PEE extract exhibited the strongest scavenging activity( IC_(50)= 7. 6 mg / L). H_2O_2 treatments induced oxidative stress in Ha Ca T and thus caused a decrease in antioxidant enzyme activities of SOD and CAT. However,the PEE extracts of 50%,70% and 95% ethanol could observably increase the enzyme activity of SOD and CAT. Among these,the 70% ethanol extracted PEE showed significant effect on enzyme activities in a dosedependent manner. It could also obviously improve the cell viability and reduce the intracellular ROS level( compared with oxidative stress group,P <0. 05 or P < 0. 01). In addition,70% ethanol extracted PEE could remarkably enhance the expression of Nrf2 mRNA,a gene that regulates the antioxidative signaling pathway. Conclusion The findings of the present study suggest that 70% ethanol extracted PEE can attenuate H_2O_2-induced oxidative damage,which functions via the regulation of the Nrf2-related anti-oxidative signaling pathway,enhancement of the antioxidant activity of SOD and CAT,and reduction of ROS level

基于地貌特征的青藏高原边缘泥石流沟分类

青藏高原地形急变带受构造运动、极端降水等因素的影响，呈现泥石流高发、群发的特 点。对泥石流沟地貌特征的科学分类有利于探索泥石流发生机制、确定防治对策，对山区防灾 减灾和生态修复具有重要意义。本文以青藏高原边缘7 个泥石流高发流域为研究对象，开展地 貌测量和统计分析。通过非度量多维尺度分析，将泥石流沟分为3 种类型：I 型是基岩下切区暴 雨型泥石流；II 型是基岩下切区冰川融水型泥石流；III 型是沉积盆地下切区暴雨型泥石流。通 过Kruskal-Wallis 检验进一步分析3 类泥石流沟地貌差异性，从地质、地貌与气候等方面探讨了 3 类泥石流沟的松散物来源与水沙输移特性。在气候变暖的影响下，II 型泥石流的活跃性将增 大；随着极端降雨频率的增加，I 型和III 型泥石流活跃性也将增加。</p