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表面增强拉曼散射(surface-enhanced Raman scattering, SERS)技术以其独特的谱带窄、灵敏度高、抗光漂白、原位和无损等优势,在疾病诊断和生物分析领域得到了越来越广泛的应用。本文介绍了近几年来应用于生物大分子、病原微生物、细胞和活体检测分析中的最新SERS技术,并分别从标记与非标记的角度对其进行了阐述,总结了SERS标记检测生物大分子的基本识别模式,简述了检测低浓度病原微生物的SERS技术,着重评述了SERS检测技术在细胞和活体研究中的应用,并对基于SERS的疾病诊断和生物分析技术的发展趋势进行了初步展望。 相似文献
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采用固相合成法制备了La0.8Sr0.2Ga0.8Mg0.2O3(LSGM8282)和La0.8Sr0.2Ga0.8Mg0.15Co0.05O3 (LSGMC5), 利用四电极交流阻抗法和Hebb-Wagner 极化法对比研究了两种材料的总电导率和电子电导率. 实验结果表明,
LSGM8282 的总电导率与氧分压无明显依赖关系, 而LSGMC5 的总电导率在高氧分压区随氧分压降低而增加,在中等氧分压区域基本保持不变. 在973-1173 K的温度范围内, LSGM8282的自由电子电导率以及电子空穴电导率的氧分压级数分别为-1/4和1/4.在1073-1173 K的温度范围内, LSGMC5的自由电子电导率以及电子空穴电导率的氧分压级数分别为-1/4和约为1/8, 表明LSGMC5的空穴产生机制可能与LSGM8282不同. LSGM8282 的氧离子电导率与氧分压无关, 而LSGMC5 的氧离子电导率在高氧分压区随氧分压的减小而增加. 相似文献
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基于固体氧化物电解池的高温电解水蒸气是一种可以在低碳排放条件下实现大规模氢气制备的技术。固体氧化物电解池的工作条件,尤其是所通入的气体组成和压力对其性能有很大的影响。本文基于计算流体力学软件建立了电解池理论模型来研究固体氧化物电解池的氧电极上通入不同氧分压的吹扫气对电解池反应特性的影响,文中所研究的氧分压范围为1.01×10~3–1.0×10~5 Pa。结果表明,可逆的开路电压随着氧分压的提高而增大,然而由活化极化、欧姆极化和浓差极化共同作用导致的极化电压随着氧分压增大而降低。在低电流密度时氧分压越小固体氧化物电解池性能越好,而在高电流密度时氧分压越大固体氧化物电解池性能越好。因此在低电流密度时采用低氧分压吹扫气有利于降低电解过程的耗电量,在高电流密度时采用氧气作为吹扫气有利于减少电解水的电能消耗并能够得到纯氧作为副产物以提高经济价值。 相似文献
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毛细管电泳安培型电化学检测法 总被引:2,自引:0,他引:2
本文评述了近年来安培型电化学检测法在毛细管电泳中的发展概况,归纳了二种检测方式及其装置的结构特点。阐述了金属电极、液膜电极和修饰电极等在电化学检测应用研究中的作用以及此方法在微区分析、活体分析中的重要意义,并展望了其发展前景。 相似文献
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神经化学信号传递是实现大脑复杂功能的基础,因此发展神经化学信号的活体原位检测方法,对于探索脑功能和脑疾病的神经化学分子机制具有重要意义。光电化学传感技术具有灵敏度高、背景信号低和易于微型化等优点,是活体原位分析的潜在有力工具。然而,常见的光电活性材料需要短波长的光激发,其组织穿透深度不足,限制了在活体分析中的应用。基于此,本文构建了一种可近红外激发的光电化学微传感器,用于脑内三磷酸腺苷(ATP)的原位检测。将稀土掺杂的上转换纳米颗粒(UCNPs)引入传感界面,用UCNPs的发光激发电极表面的光电活体材料产生光电流信号,通过荧光染料(TAMRA)标记的核酸适配体调节UCNPs的发光,发展一种基于光学调控策略检测脑内ATP的光电化学传感新方法。所制备的微传感器成功用于炎症模型中小鼠脑内ATP的原位检测,初步探索了脑部炎症与ATP水平变化的关系。 相似文献
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多模式小动物活体成像系统广泛应用于高校科研实验室的活体动物检测研究,为癌症的发生及发展、基因治疗和免疫学及分子生物学等相关研究领域提供直观的活体侦测手段.结合多年的多模式小动物活体成像系统的使用,总结了多模式小动物活体成像系统的使用经验,并探讨了多模式小动物活体成像系统在大学生创新实践中的应用.旨在提高多模式小动物活体成像系统的使用效率,并拓宽多模式小动物活体成像系统的实验资源. 相似文献
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研究了水含量和聚合反应温度Tp 对MeOH BF3体系引发异丁烯 (IB)阳离子聚合反应的转化率、产物的分子量及分子量分布的影响 ,求出在不同水含量条件下的Tp 对聚合物分子量影响的数学方程及相应的聚合度活化能Ep ,以期对体系中存在的微量水加以充分利用 .结果表明 ,[H2 O]和Tp 两者共同影响IB阳离子聚合反应过程及产物的分子参数 .当Tp 由 - 10 0℃升高至 - 5 0℃时 ,聚合转化率先增加到一定值后再减小 ,在- 80℃~ - 70℃范围内出现峰值 .在 [H2 O]较低时 ,Tp 明显影响着聚合产物的分子量及分子量分布 ,Tp 越低 ,分子量越高 ,分子量分布越窄 ;在 [H2 O]较高时 ,Tp 对分子量的影响程度较小 ,说明此时水对聚合反应的影响更为突出 .体系中水含量增大对IB阳离子聚合反应呈现不利作用 ,当 [H2 O]由 1 5× 10 - 3mol L增加至 4 6×10 - 3mol L时 ,Ep 由 - 4 0kJ mol增大至 - 17kJ mol ,说明随着 [H2 O]增大 ,水的负面效应更加明显 ,既促进副反应 ,又阻碍链增长反应 ,增长活化能增大 ,聚合物分子量降低 ,分子量分布变宽 .水的负面作用也随着Tp 升高而变得明显 . 相似文献
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在广义梯度近似(GGA)下利用全电势线性化的缀加平面波法(FPLAPW)计算了钛酸钙(CaTiO3)的电子结构.将实验测得的晶胞体积记为V0,计算中所用的晶胞体积记为V.当V/V0=1.0时, Ti离子位移为零相应于总能量低能态,钛酸钙不会发生铁电相变.但如果其体积膨胀10%,则Ti离子的位移将导致能量极小值.这意味着在立方钛酸钙中有发生铁电相变的趋势,表明在钛酸钙中存在着体积诱发的铁电相变,即钛酸钙为先兆型铁电体.态密度在V/V0=1.1时, Ti d电子和O(2) p电子之间存在强烈的轨道杂化,这种杂化是出现铁电性的必要条件.电场梯度的结果也表明了这一点. 相似文献
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The title compound is monoclinic, space group P21/c, Z = 4, with a = 6.632, b = 11.890, c = 10.012 Å and β 90.80°. The structure, which was solved by direct methods and refined to R = 0.086 for 1783 diffractometer intensities, consists of infinite (? P? O? Zn? O? P? ) chaines. Zn atoms are coordinated tetrahedrally by 2 Cl and 2 O atoms of different ligand molecules with Zn? O and Zn? Cl distances of 1.95 and 2.24 Å, respectively. 相似文献
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1 INTRODUCTION At present the researches on more efficient solid-state laser materials become more important for the rapid development of diode-laser pumped solid-state laser. More researches have been devoted to the double borate compounds RX3(BO3)4 (R = Y, La, Gd and X = Y, Al, Sc), some of which exhibit good chemical and physical properties[1~10]. The rare earth and alkali-halide double borates M3Ln2(BO3)4 (M = Ca, Sr, Ba and Ln = LaLu and Y) were reported in literatures[11… 相似文献
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G. L. N. Reddy Pritty Rao J. V. Ramana S. Vikramkumar V. S. Raju Sanjiv Kumar 《Journal of Radioanalytical and Nuclear Chemistry》2012,294(3):401-404
The paper describes the determination and depth profiling of oxygen in thin oxide films using 18O(p,??)15N nuclear reaction. The excitation function of 18O(p,??)15N nuclear reaction exhibits a resonance at 629?keV and a plateau at 730?keV with uniform cross-section. The resonance is used to determine the depth profile of oxygen in films while the plateau, to estimate its overall concentration. The resonance, characterized by a width of 2.1?keV enables high-depth resolution (~20?nm) measurements and has a probing depth of more than a micron. The paper presents depth profile measurements of oxygen in several metal oxide films (SiO2, TiO2 and HfO2) using this resonance. Possible interferences arising from 15N(p,??)12C, 19F(p,??)16O and 11B(p,??)2?? nuclear reactions are also discussed. It has been shown that it can serve as a suitable alternative to 3.05?MeV 16O(??,??)16O resonant scattering which is generally used for depth profiling oxygen. It is, in fact, more reliable and precise in materials that witness significant large angle multiple scattering. It can also be advantageously used to monitor 18O, when used as a tracer. 相似文献
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Oelckers S Ziegler T Michler I Röder B 《Journal of photochemistry and photobiology. B, Biology》1999,53(1-3):121-127
For about ten years, it has been debated whether in principle it is possible to detect 1O2 located within the cell membrane by performing experiments with cell suspensions or even in tissue. In this paper we present our investigations on photosensitized red-cell ghost suspensions (RCGSs) and our strategy for the detection of luminescence of singlet oxygen (1O2) from the inside of the cell membrane. Using a very sensitive apparatus for time-resolved 1O2 detection, a very promising sensitizer and an adequate experimental strategy, a very small amount of the detected luminescence indeed can be attributed to 1O2 from the inside of the ghost membrane. 相似文献
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Bernini MC Snejko N Gutierrez-Puebla E Brusau EV Narda GE Monge MÁ 《Inorganic chemistry》2011,50(13):5958-5968
Two new holmium-succinate frameworks have been synthesized by hydrolysis in situ of the succinylsalicylic acid under different hydrothermal conditions. Compound 1, [Ho(2)(C(4)H(4)O(4))(3)(H(2)O)(2)]·0.33(C(7)H(6)O(3)), P ?i space group, has a novel structure composed by 1D-SBUs consisting of [HoO(9)] chains of polyhedra linked by the succinate ligands giving a 3D framework. Compound 2, [Ho(2)(C(4)H(4)O(4))(3)(H(2)O)(2)], also belonging to the P ?i space group, has a denser structure. The role of the in-situ-generated salicylic acid on formation of both structures is studied by means of a synthesis design methodology. A topological study of the new holmium succinate compounds in comparison with the previously reported 3D holmium-succinate framework is performed here. 相似文献
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Hydrates of Fluorosulfuric Acid: The Melting Diagram of the System FSO3H? H2O and the Crystal Structure of the Monohydrate, (H3O)FSO3 The system FSO3H? H2O has been investigated by difference thermal analysis. By adhering to exclusively lower temperatures in the course of preparation and manipulation of the measuring samples, it was possible to avoid hydrolysis of the S? F bond and to obtain a quasi-binary melting diagram. This reveals the existence of four crystalline hydrates FSO3H · nH2O with n = 1, 2, 3, and 4, melting at –12, –53 (dec.), –46, and ?63°C (dec.), respectively. The structure of the monohydrate has been determined (crystal system orthorhombic, space group Pnma, Z = 4 formula units per unit cell; lattice constants a = 8.055, b = 6.465, c = 7.459 Å at ?50°C; final R value with 515 independent observed MoKα diffractometer data at 0.043). The result is a typical oxonium salt, (H3O)FSO3, characterized by strong hydrogen bonds only of the kind O? H…?O and with interesting relations to the isosteric, dimorphic compound (H3O)ClO4. 相似文献