单细胞拉曼光谱分析地中海贫血红细胞的氧合态和去氧态

应用光镊拉曼光谱系统俘获单个红细胞并收集其拉曼光谱,选择I1638/I1547比值为区分红细胞氧合及去氧态指标,比较分析地中海贫血HbH-CS和健康个体单个红细胞的氧循环过程的氧合和去氧能力及去氧态群体红细胞.结果发现,在氧循环的去氧态中,地中海贫血HbH-CS的I1638/I1547显著高于正常对照;氧合态的I1638/I1547也略高于正常对照.群体统计中,若以小于正常对照I1638/I1547的平均值为去氧态基准,则正常对照46%的红细胞达到去氧态.而地中海贫血HbH-CS仅有15%,表明地中海贫血HbH-CS红细胞的氧合能力较强,但去氧能力显著低于正常对照,而且地中海贫血HbH-CS红细胞个体差异较大.该研究在单细胞水平上,揭示了地中海贫血HbH-CS红细胞氧合,去氧能力以及细胞个体差异性,以评价其携氧功能,为诊断治疗提供一定的理论依据.     

Molecular mechanisms of photochemotherapy (Review)

Mechanisms of photophysical, photobiological, and therapeutic action of light on blood in vivo are discussed based on results of spectral and clinical studies of blood, plasma, and erythrocytes. Spectral manifestations of photochemical reactions initiated in blood by therapeutic doses of radiation in vivo with light of different wavelengths are considered. Spectral and clinical results of blood investigations are compared for patients whose complex treatment included intravenous blood irradiation and magnetotherapy. Mechanisms for secondary (dark) reactions induced by the action of light on blood in vivo are discussed. The radiation of laser and non-laser light sources used at present for intravenous blood irradiation (365, 405, 450, 530, 632, 635, 808 nm) is shown to fall within hemoglobin absorption bands. The conclusion is made that blood absorption of laser and non-laser light radiation results in functional alteration of hemoglobin as a possible primary photoacceptor absorbing light radiation of the above wavelengths. The therapeutic effect of intravenous blood irradiation is initiated by hemoglobin functional activity modulation. Phototherapy is a means to correct it. Intravenous phototherapy should be considered as a therapeutic method that changes (provided that the dosage is correct) the balance of active oxygen species production and their inhibition by antioxidants. Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 76, No. 1, pp. 51–75, January–February, 2009.     

Eley–Rideal reaction dynamics between O atoms on β-cristobalite (1 0 0) surface: A new interpolated potential energy surface and classical trajectory study

We present a theoretical study of the collisions of atomic oxygen with O-precovered β-cristobalite (1 0 0) surface. We have constructed a multidimensional potential energy surface for the O₂/β-cristobalite (1 0 0) system based mainly on a dense grid of density functional theory points by using the interpolation corrugation-reducing procedure. Classical trajectories have been computed for quasithermal (100–1500 K) and state-specific (e.g., collision energies between 0.01 and 4 eV) conditions of reactants for different O incident angles (θ_v). Atomic sticking and O_2(adsorbed) formation are the main processes, although atomic reflection and Eley–Rideal (ER) reaction (i.e., O₂ gas) are also significant, depending their reaction probabilities on the O incident angle. ER reaction is enhanced by temperature increase, with an activation energy derived from the atomic recombination coefficient (γ_O(θ_v = 0°, T)) equal to 0.24 ± 0.02 eV within the 500–1500 K range, in close agreement with experimental data. Calculated γ_O(θ_v = 0°, T) values compare quite well with available experimental γ_O(T) although a more accurate calculation is proposed. Chemical energy accommodation coefficient β_O(T) is also discussed as a function of ER and other competitive contributions.     

Mechanism of PdO thin film formation during the oxidation of Pd(1 1 1)

We investigated the mechanism by which a surface oxide layer on Pd(1 1 1) transforms to a PdO(1 0 1) thin film during oxidation with gaseous oxygen atoms in ultrahigh vacuum. Our results provide evidence that the precursor to bulk PdO formation is a distinct oxide phase that forms as small particles, referred to as PdO seeds, after the surface oxide saturates. With increasing oxygen coverage, the PdO seeds grow in size and eventually transform to more stable particles that agglomerate to yield a PdO film. Oxidation effectively ceases when the surface oxide layer is completely replaced by the bulk PdO film, demonstrating that the surface oxide is needed for PdO formation at the conditions studied. Both the kinetics of PdO formation and the final thickness of the PdO thin film depend strongly on the thermal stability of the PdO seeds. Below the decomposition temperature of the seeds (600 K), oxidation follows kinetics similar to Langmuirian adsorption and appears to be limited only by the rate of oxygen adsorption onto the surface oxide. In contrast, PdO formation above 600 K initially exhibits acceleratory kinetics, with the rates starting low but increasing steadily during the initial growth of PdO. We also observe a significant decrease in PdO(1 0 1) film thickness and improved crystallinity when oxidation is conducted below 600 K. We show that the trends observed in the oxidation kinetics and film thickness can be qualitatively explained within the context of a model in which the thermodynamic stability of PdO particles increases with increasing particle size and PdO seeds/particles coexist with a two-dimensional (2D) gas of oxygen atoms adsorbed on the surface oxide layer. This model suggests that the PdO particle-2D gas coexistence relation gives rise to three distinct growth regimes, namely, stable seed nucleation, metastable seed nucleation and oxygen dissolution into the subsurface where the latter is established at 2D gas coverages below the stability limit of a flat PdO surface.     

三倍频Nd:YAG激光抽运氧气中的受激拉曼和布里渊散射

报道了三倍频脉冲Nd：YAG激光（355nm）在两种不同带宽模式下抽运氧气中受激拉曼散射（SRS）和受激布里渊散射（SBS）的实验研究。在宽带（约1cm^-1）抽运模式下,只测到了前向受激拉曼散射,而没有观察到后向散射,其一级和二级斯托克斯最大能量转换效率可达22％和8％。在窄带（约0．003cm^-1）模式下,前向、后向受激拉曼散射和受激布里渊散射都测量到了,但大部分抽运能量都转换到受激布里渊散射,其转换效率可达67％。测量了两种带宽模式下各散射组分在它们最佳转换时的波形;窄带情况下后向受激拉曼散射和受激布里渊散射的脉宽分别可压窄至1．5ns和2．3ns,不到抽运脉宽的三分之一,使得受激布里渊散射峰值功率可大大高于抽运功率。对氧气中前向、后向受激拉曼散射和受激布里渊散射之间的竞争进行了讨论。     

A Novel Photocleaver with Long Wavelength Absorption-Highly Efficient Antitumor Agent： 4- （2-Diethylamino-ethylamino） - 8-oxo-8H-acenaphtho- [ 1,2-b ] pyrrole-9-carbonitrile

IntroductionThe design of novel DNA photocleavers is of greatsignificance from the standpoints of chemistry,biology,and medicine[1].There have been many reports aboutDNA photocleavers.Usually,they bind to DNAviain-tercalation,electrostatic binding or self-stacking inter-actions[2,3],but under photoirradiation they can initiatesignificant damage to DNA without external chemicalinitiatorsviaa wide variety of ways,such as electrontransfer,the formation of radicals or singlet oxy-gen[4,5].It …     

聚二甲基硅氧烷基质微流控芯片通道的氧气氛改性研究

通过将新制的PDMS微流控芯片置于氧气氛中对通道表面进行处理的简单方法,使电渗流大小及稳定性有了显著的改善。同时研究了氧气处理PDMS通道表面的时间对电渗流的影响,得到氧气处理的最佳时间为3d。讨论了氧气作用于PDMS芯片表面的机理。在氧气处理3d的PDMS微流控芯片上进行氨基酸分离实验,得到较好的分离效果。     

隔膜式电解槽生物膜阴极降解苯酚的过程及其条件的优化

以炼油废水中的主要污染物苯酚为目标污染物, 采用不同生物膜电极反应器对苯酚进行降解, 从而寻找出降解苯酚的最佳反应途径. 研究结果表明, 运用隔膜式电解槽生物膜阴极区域对苯酚废水进行处理, 其苯酚的去除效果虽然没有在生物膜阴极与阳极相混合的混合式反应器中处理效果好, 但在18 h内苯酚浓度降解到0, 并且其化学需氧量(COD)去除率最高, 在16 h内COD去除率达到80%. 对于隔膜式电解槽生物膜阴极区域的降解条件优化后发现, 电流设定为5 mA, 初始苯酚质量浓度低于200 mg/L, 温度为35 ℃时, 苯酚降解效果最佳.     

荧光探针法研究铜离子-姜黄素体系中1O2的反应机理及在O2·-存在下1O2的测定

以1,3-二苯基异苯并呋喃(1,3-Diphenylisobenzofuran, DPBF)为荧光探针, 研究了姜黄素(Curcumin, CUR)在铜离子催化下产生的单线态氧(1O2), 其反应机理为姜黄素与溶液中的氧分子快速作用产生O2·-和H2O2等活性氧物种, 同时Cu2+与姜黄素形成复合物, 再与H2O2形成过氧化物过渡态, 过氧化物进一步与H2O2发生类Haber-Weiss反应生成1O2, 且只有Cu2+和Cu+离子可催化姜黄素并产生1O2. 1O2在1.37×10-8～3.66×10-7 mol/L浓度范围内与荧光强度下降值ΔIF有良好的线性关系, 检出限为4.12×10-9 mol/L.