Scanning near-field optical images of ordered polystyrene particle layers in transmission and luminescence excitation modes

Scanning near-field optical images of hexagonally close-packed layers of polystyrene spherical particles with a diameter of 1.0 microm have been investigated. The layers were composed of particles that were doped either totally or partially with an organic fluorescent dye. Observations were made in the transmission and luminescence excitation modes with a scanning near-field optical microscope (SNOM) with a spatial resolution shorter than the wavelength of light. The patterns observed in the SNOM images are significantly dependent on the microstructures of layers, that is, the layers are either single or double layered, and the particles are either totally or partially doped. These results are discussed in terms of specific modes of electromagnetic waves transmitting across and along the layers after the local excitation at the tip end of the scanning microprobe.     

The significance of hair mineral analysis as a means for assessing internal body burdens of environmental pollutants: Results from an IAEA Co-ordinated Research Programme

During a five-year period, the International Atomic Energy Agency supported a Coordinated Research Programme (CRP) to investigate the quantitative relationship between internal body burdens of a number of elements of environmental health significance and their respective concentrations in hair. The use of nuclear-related analytical techniques, such as neutron activation analysis, X-ray fluorescence, particle-induced X-ray emission and radiotracers, was emphasized. One aspect of the CRP focused on studies in man, using autopsy cases, of mineral distribution in five tissues, i.e. liver, kidney, lung, brain and bone in addition to hair, and the elements of primary importance were As, Cd, Cu, Hg, Pb, Se and Zn. Emphasis was placed on analytical quality assurance. Hair and internal tissue samples were obtained from subjects from Bulgaria, China, the former German Democratic Republic, Hungary, Japan, Norway and Sweden.     

碳笼化合物的高效液相色谱研究

采用化学键合固定相（ＤＮＡＰ－ＳＰ）及二元混合流动相（５０％苯－正已烷），对碳笼化合物Ｃ６０与Ｃ７０的高效液相色谱（ＨＰＬＣ）分析及分离进行了研究。比较了多种流动相对Ｃ６０、Ｃ７０分离效果的影响，苯／正已烷混合体系是最好的流动相。     

Emission ratiometric imaging of intracellular zinc: design of a benzoxazole fluorescent sensor and its application in two-photon microscopy

Zinc and calcium are ubiquitous intracellular metals, and while a variety of quantitative probes have been developed for measuring intracellular changes in calcium concentration, the same is not true of zinc. We describe here the design, synthesis, and properties of the benzoxazole-based, ratiometric zinc probe, Zinbo-5. This bright fluorescent reporter has a quantum yield of 0.1 in the zinc-form, exhibits a Kd for Zn2+ in the nanomolar range, and shows significant changes in both excitation and emission maxima upon zinc binding. The utility of this cell permeable probe is demonstrated in fluorescence microscopy emission ratio imaging experiments on mammalian cells. We further show that Zinbo-5 is well suited for two-photon excitation microscopy ratio imaging and can readily reveal changes in intracellular zinc concentration within optical planes of single cells. To the best of our knowledge, this is the first example of two-photon excitation microscopy applied to ratio imaging of zinc. These methods can be applied to real-time emission or excitation ratio imaging studies of zinc physiology in living cells.     

Synthesis and evaluation of novel 2-oxo-1,2-dihydro-3-quinolinecarboxamide derivatives as potent and selective serotonin 5-HT4 receptor agonists

A series of 8'-substituted N-(endo-8-azabicyclo[3.2.1]oct-3-yl)-1-isopropyl-2-oxo-1,2-dihydro-3-quinolinecarboxamides were synthesized. The 5-HT4 receptor agonistic activity was evaluated using the isolated guinea pig ileum preparation. Of the compounds synthesized, N-(endo-8-(3-hydroxypropyl)-8-azabicyclo[3.2.1]oct-3-yl)-1-isopropyl-2-oxo-1,2-dihydro-3-quinolinecarboxamide (15a, TS-951) exhibited the most potent serotonin 5-HT4 receptor agonistic activity. This compound had a high affinity for the serotonin 5-HT4 receptor although it had no affinities for other broad spectrum receptors. Furthermore, it remarkably enhanced gastrointestinal motility in conscious fed dogs without unfavorable effects that non-selective serotonin 5-HT4 receptor agonist has. TS-951 may be useful in improving gastrointestinal dysfunction.     

Piezoelectric immuno sensor for the detection of candida albicans microbes

The system consists of an AT-cut quartz piezoelectric crystal, oscillator and frequency counter. The surface of the palladium-plated electrodes is oxidized anodically, and anti-Candida antibody is immobilized onto the surface. The crystal sensor is dipped into Candida suspension and the surface mass increase, caused by immuno-adsorption of Candida, is measured by the decrease in the resonant frequency of the crystal. The frequency shift is correlated with C. albicans concentrations in the range 10⁶?5 × 10⁸ cells cm^?3. The crystal sensor showed no response to Saccharomyces cerevisiae.     

Gradient expansion for a spiral phase in a spin-fermion model

Starting from a doped spin-fermion model for high-temperature superconductors, we derive an effective continuum theory for the spin degrees of freedom by means of a gradient expansion around a spiral spin configuration. By integrating out the fermions in a path-integral representation, we obtain an effective spin-action. An incommensurate, planar spiral configuration for the spin-background is assumed. The long-wavelength limit is obtained by expanding the effective action in powers of a short distance cutoff. The occurring infinite series can be summed to all orders of the coupling constant by exploiting the constraint that the order parameter lives on a circleS ₁. It is shown that the low-energy limit of the effective action can be mapped onto a O(2) nonlinear model and an additional term due to parity breaking.     

Kritische Struktur-bildung bei ampholyüschen Phospholipid-Einzelschichten,analysiert durch die Charakteristika der Calciumbindung

Ohne Zusammenfassung     

Iodine separation procedure for the determination of129I and127I in soil by neutron activation analysis

A radiochemical neutron activation analytical method for the determination of¹²⁹I and¹²⁷I in soil samples was studied. Iodine was separated from the sample prior to the irradiation by volatilization, i.e. by combustion of the sample and trapping of the iodine in an alkaline solution together with a reducing agent. This method enables one to digest samples containing up to 100 g dry matter. The chemical yield was mostly more than 90%. After irradiation the iodine fraction was further purified by solvent extraction. The detection limit of the¹²⁹I/¹²⁷I ratio was 1×10^–9.