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931.
<正>An electrochemical sensor for the detection of the natural double-stranded DNA(dsDNA) damage induced by PbSe quantum dots(QDs) under UV irradiation was developed.The biosensing membranes were prepared by successively assembling 3- mercaptopropionic acid,polycationic poly(diallyldimethyl ammonium) and dsDNA on the surface of the gold electrode.Damage of dsDNA was fulfilled by immersing the sensing membrane electrode in PbSe QDs suspension and illuminating it with an UV lamp. Cyclic voltammetry was utilized to detect dsDNA damage with Co(phen)_3~(3+) as the electroactive probe.The UV irradiation,Pb~(2+) ions liberated from the PbSe QDs under the UV irradiation and the reactive oxygen species(ROS) generated in the presence of the PbSe QDs also under the UV irradiation were the three factors of inducing the dsDNA damage.The synergistic effect of the three factors might dramatically enhance the damage of dsDNA.This electrochemical sensor provided a simple method for detecting DNA damage,and may be used for investigating the DNA damage induced by other QDs. 相似文献
932.
Synthesis, spectroscopic and electrochemical property of an unsymmetrical porphyrin and its Zn compound 总被引:1,自引:0,他引:1
Chang Fu Zhuang Yu Jing Zhang Ai Qing Xia Wen Hui Lian Yun Fang Wang Ping Zhang Tong Shun Shi 《中国化学快报》2010,21(7):769-773
<正>In this article,a new 5-(p-maleicaminophenyl)-10,15,20-triphenylporphyrin(H_2P) and relative zinc compound(ZnP) were synthesized and characterized by means of elemental analyses,UV-vis,IR,MS and ~1H NMR spectroscopies.Furthermore,we have investigated the fluorescence spectroscopy of these compounds.The oxidation and reduction properties of the compounds were studied by the cyclic voltarnmetry,the oxidation-reduction potentials were obtained. 相似文献
933.
Serge Kokot 《中国化学快报》2010,21(8):963-967
<正>The interactions of carbofuran and DNA were studied using voltammetry and fluorescence spectroscopy.The formation of carbofuran-DNA makes the current peak of DNA decreased by voltammetry method.The binding number(n) and constant(K_a) for complex carbofuran-DNA were calculated to be 1.06±0.04 and 0.11±0.03mol~(-1) L,respectively by fluorescence measurement.Chemometrics approach,such as singular value decomposition(SVD) was used to evaluate the number of spectral species in the drug-DNA binding process.And the pure spectra and concentration profiles in the kinetic system were clearly deduced by multivariate curve resolution alternating least squares(MCR-ALS) with the initial estimates by evolving factor analysis(EFA). 相似文献
934.
<正>The electrocatalytic oxidation of methanol at the platinum electrode modified with Eu-Fe cyanide-bridged binuclear complexes (Eu-Fe film) was investigated for the first time by cyclic voltammetry.Compared with the bare platinum electrode,the results showed that the modified electrode had excellent electrocatalytic activity for the oxidation of methanol;the oxidation peak potential shifted more negatively and the peak current increased about twenty times.The electrooxidation of methanol at the modified electrode with Eu-Fe cyanide-bridged binuclear complexes material exhibited the better tolerance capacity to poison of intermediate species;the peak current was proportional to the concentration of methanol in the range of 0.5-2.0mol/L (R~2 = 0.9991,n =7),which was a comparatively wider linear range.Moreover,based on the linear relationship between the peak current and the square root of scan rate,electrocatalytic oxidation process of methanol was confirmed to be a diffusion control process.Furthermore,according to the counting of electron transfer number(n_α) in the rate-limiting step and the slope of linear equation between acidity of electrolyte and the oxidation peak potential(E_p),the possible mechanism of the electrooxidation of methanol at the modified electrode was primarily discussed. 相似文献
935.
用ICPOES法检测了54例男性少精、弱精不育者精液中Ca、Cd、Cu、Fe、Mg、Mn、Ni、Zn元素的含量,并对相关含量进行数据分析。结果表明,精液中微量元素含量的改变是影响精液质量的重要原因之一。 相似文献
936.
937.
膦系阻垢剂阻碳酸钙垢机理的研究 总被引:5,自引:0,他引:5
在模拟循环水中, 通过静态阻垢实验研究了HEDP, PBTCA, ATMP和EDTMP对碳酸钙的阻垢性能, 在相同的加药浓度下(按物质的量浓度计)阻垢性能的强弱顺序为HEDP>PBTCA>ATMP>EDTMP; 同时采用分子动力学方法, 模拟计算了阻垢剂负二价离子与方解石(104), (102), (202)和(113)面的相互作用. 结果表明: 阻垢剂分子中的膦酸基团和羧酸基团与碳酸钙中的Ca2+形成的离子键对吸附起到了主要作用, 同时阻垢剂与晶面间存在较弱的范德华力相互作用. 阻垢剂与各晶面的结合能强弱顺序为(113)≥(102)≥(202)>(104); 分子中的羟基易与垢晶面形成氢键而加强阻垢效果; 羧基的位置不同对阻垢作用的影响不同. 将静态阻垢的实验结果与分子动力学模拟结果进行了相关性分析, 发现阻垢剂在(104)面和(102)面上的吸附对阻垢作用的贡献较大. 相似文献
938.
Mn–N-codoped TiO2 nanocrystal photocatalysts responsive to visible light were synthesized for the first time by a simple hydrothermal synthesis
method. X-ray powder diffraction (XRD) measurement indicated that all the photocatalysts have an anatase crystallite structure,
and that increase of the doping concentration had little effect on the structure and particle size. Compared to N-doped TiO2, a shift of the absorption edge of Mn–N-codoped TiO2 to a lower energy and a stronger absorption in the visible light region were observed. The Mn–N-codoped TiO2 showed higher photocatalytic reactivity than undoped TiO2 or N-doped TiO2 for the photodegradation of rhodamine B (RhB) under visible light irradiation. The highest photocatalytic activity was achieved
on 0.4 mol% Mn–N–TiO2 calcined at 673 K. 相似文献
939.
Wen Wang Jian-Cun Rao Hua Ke Ming Feng Rui-Lin Xia Qing-Chang Meng De-Chang Jia Yu Zhou 《Journal of Sol-Gel Science and Technology》2010,56(1):87-92
We report the independent invention of perovskite ferroelectric nanowires strontium bismuth tantalate (SrBi2Ta2O9, SBT). Electrophoretic sol–gel techniques have been used successfully. The morphology and structures are analyzed via SEM,
TEM and XRD. SBT nanowires and nanoparticles filled template revealed 30 and 40 μm long, respectively. SBT are proved to be
a single phase of orthorhombic perovskite structure. As it indicated, SBT nanowires has been crystallized at 700 °C. To minimize
surface polarity, SBT nanowires oriented preferentially along the growing axis (c axis) by translation and rotation of atomic clusters of SBT. 相似文献
940.
Guanglin Xia Dr. Xuebin Yu Prof. Yanhui Guo Zhu Wu Prof. Chuanzhen Yang Prof. Huangkun Liu Prof. Shixue Dou Prof. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2010,16(12):3763-3769
The monoammoniate of lithium amidoborane, Li(NH3)NH2BH3, was synthesized by treatment of LiNH2BH3 with ammonia at room temperature. This compound exists in the amorphous state at room temperature, but at ?20 °C crystallizes in the orthorhombic space group Pbca with lattice parameters of a=9.711(4), b=8.7027(5), c=7.1999(1) Å, and V=608.51 Å3. The thermal decomposition behavior of this compound under argon and under ammonia was investigated. Through a series of experiments we have demonstrated that Li(NH3)NH2BH3 is able to absorb/desorb ammonia reversibly at room temperature. In the temperature range of 40–70 °C, this compound showed favorable dehydrogenation characteristics. Specifically, under ammonia this material was able to release 3.0 equiv hydrogen (11.18 wt %) rapidly at 60 °C, which represents a significant advantage over LiNH2BH3. It has been found that the formation of the coordination bond between ammonia and Li+ in LiNH2BH3 plays a crucial role in promoting the combination of hydridic B? H bonds and protic N? H bonds, leading to dehydrogenation at low temperature. 相似文献