Distribution and metabolism of 14C-sulfoquinovosylacylpropanediol (14C-SQAP) after a single intravenous administration in tumor-bearing mice.

Sulfoquinovosylacylpropanediol (SQAP) is a novel potent radiosensitizer that inhibits angiogenesis in vivo and results in increased oxigenation and reduced tumor volume. We investigated the distribution, metabolism, and excretion of SQAP in male KSN-nude mice transplanted with a human pulmonary carcinoma, Lu65. For the metabolism analysis, a 2 mg (2.98 MBq)/kg of [glucose-U-14C]-SQAP (CP-3839) was intravenously injected. The injected SQAP was decomposed into a stearic acid and a sulfoquinovosylpropanediol (SQP) in the body. The degradation was relatively slow in the carcinoma tissue.1,3-propanediol[1-14C]-SQAP (CP-3635) was administered through intravenous injection of a 1 mg (3.48 MBq)/kg dose followed by whole body autoradiography of the mice. The autoradiography analysis demonstrated that SQAP rapidly distributed throughout the whole body and then quickly decreased within 4 hours except the tumor and excretion organs such as liver, kidney. Retention of SQAP was longer in tumor parts than in other tissues, as indicated by higher levels of radioactivity at 4 hours. The radioactivity around the tumor had also completely disappeared within 72 hours.

Observation of Fine Distribution of Minor Dopants in an Erbium-Doped Fiber Core using a Sample Thinning Technique for Field Emission Electron Probe Microanalysis.

To observe the fine distribution of minor aluminum and germanium dopants in the erbium-doped fiber (EDF) core of an optical amplifier, a sample thinning technique was applied for field emission electron probe microanalysis (FE-EPMA) together with wavelength-dispersive X-ray spectrometry. This technique significantly improved the spatial resolution without much degradation of the minimum detection limit for FE-EPMA. As such, this enabled us to observe the distribution of minor dopants in EDF. Moreover, we propose a very simple sample preparation to prevent electron-beam radiation damage, a problem involved with FE-EPMA of low-conductivity materials such as SiO2 glass, which is the main component of EDF.

Effect of convergent beam semiangle on image intensity in HAADF STEM images.

In this study, we experimentally and theoretically show that the intensities of bright spots in a spherical aberration (C(s))-uncorrected high-angle annular dark-field (HAADF) scanning transmission electron microscope (STEM) image of [011]-oriented Co(3)O(4), which has two different numbers of Co atoms in the projected atomic columns, are reversed with increasing sample thickness. However, C(s)-corrected HAADF STEM images produce intensities that correctly depend on the average number of atoms in the projected atomic columns. From an analysis based on the Bloch-wave theorem, it is found that an insufficient semiangle of the incident convergent beam yields intensities that do not depend on the average atomic number in the atomic columns.

Effect of chromatic aberration on atomic-resolved spherical aberration corrected STEM images.

The effect of the chromatic aberration (C(c)) coefficient in a spherical aberration (C(s))- corrected electromagnetic lens on high-resolution high-angle annular dark field (HAADF) scanning transmission electron microscope (STEM) images is explored in detail. A new method for precise determination of the C(c) coefficient is demonstrated, requiring measurement of an atomic-resolution one-frame through-focal HAADF STEM image. This method is robust with respect to instrumental drift, sample thickness, all lens parameters except C(c), and experimental noise. It is also demonstrated that semi-quantitative structural analysis on the nanometer scale can be achieved by comparing experimental C(s)- corrected HAADF STEM images with their corresponding simulated images when the effects of the C(c) coefficient and spatial incoherence are included.

Engineering low-aspect ratio carbon nanostructures: nanocups, nanorings, and nanocontainers.

The synthesis of carbon nanostructures, with interesting morphologies, has created a revolution in nanotechnology; carbon nanotube is a case in point, but other nanoscale morphologies of graphitic carbon could provide compelling uses. In particular short structures, including very short nanotubes, have proven impossible to be grown by existing techniques due to the difficulty in controlling and terminating growth during initial stages. Here we present architectures engineered from graphitic carbon, having up to 10(5) times smaller length/diameter (L/D) ratios compared to conventional nanotubes, revealing unique morphologies of nanocups, nanorings, and large area connected nanocup arrays. Such highly engineered hollow nanostructures were fabricated using precisely controlled short nanopores inside anodic aluminum oxide templates. The nanocups were effectively used to hold and contain other nanomaterials, for example, metal nanoparticles, leading to the formation of multicomponent hybrid nanostructures with unusual morphologies. The results reported here open up possibilities to integrate new morphologies of graphitic carbon in nanotechnology applications.

Quantitative and easy estimation of a crystal bending effect using low-order CBED patterns.

The quantitative measurement of a crystal bending effect is performed using low-order zone-axis convergent beam electron diffraction (CBED) patterns. Although the accuracy of the present method is inferior to that of the method of using split higher order Laue zone lines, this method enables us to estimate the crystal bending effect at a region very close to the interface and to easily judge whether the crystal bending effect results in a tensile bend or a compressive bend. As an application of the present method, the crystal bending effect at a region close to the SiGe/Si interface was measured. It was found that the crystal bending effect is due to a thin-foil relaxation of almost 0.3 degrees at a region that is approximately 10 nm away from the interface.

Quantitative structural analysis of twin boundary in alpha-Zn7Sb2O12 using HAADF STEM method.

The structure and composition of the 1/4{110} twin boundary in alpha-Zn7Sb2O12 have been determined by using quantitative high-angle annular dark field scanning transmission electron microscopy (HAADF STEM) analysis. The noise in the experimental HAADF STEM images is reduced by using the maximum entropy method and average processing, and the parameters used in dynamical simulations are experimentally determined. From the analysis, it has been found that octahedral sites in the twin boundary slightly shift parallel to the [110] direction, and a reduction of the Sb concentration at the octahedral sites on the plane adjacent to the twin boundary was detected. The reduction was measured from three regions in the same twin boundary, and the Sb concentrations were 4 +/- 3, 8 +/- 3 and 19 +/-2 at% from 33 at%.

Measurement of twofold astigmatism of probe-forming lens using low-order zone-axis ronchigram.

By using a low-order zone-axis ronchigram of a crystalline sample, a simple method for measuring twofold astigmatism of a probe-forming lens is proposed. This method allows precise measurement of the value of astigmatism from only one experimental ronchigram.

Extended dynamical HAADF STEM image simulation using the Bloch-wave method.

An extended method is proposed for the precise simulation of high-angle annular dark-field (HAADF) scanning transmission electron-microscope (STEM) images for materials containing elements with large atomic numbers and for thick specimens. The approach combines a previously reported method utilizing two kinds of optical potential [Watanabe, Yamazaki, Hashimoto & Shiojiri (2001). Phys. Rev. B, 64, 115432] with a representation of a crystal sliced into multiple layers. The validity of the method is demonstrated by simulated images for elements with the diamond structure (Si, Ge and alpha-Sn) and for the perovskite BaTiO3.

Precise measurement of local strain fields with energy-unfiltered convergent-beam electron diffraction.

A simple and robust method to precisely determine local strain fields using energy-unfiltered convergent-beam electron diffraction is presented. This method involves the subtraction of background intensity, the extraction of higher-order Laue-zone lines by tracing using a Radon transformation and a system of analytical strain determination without the need for an optimization routine such as chi2-based minimization. As an example, the measurement of residual strain in a silicon-on-insulator wafer is demonstrated. It is found from micro-Raman spectroscopy analysis that, at the nanometre scale, this measurement succeeds with an accuracy of 0.06%.