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Experimental characterization of the nanostructure of metastable functional materials has attracted significant attention with recent advances in computational materials discovery. However, since metastable glass-ceramics are easily damaged by irradiation, damage-free nanoimaging has not been realized thus far. Herein, we propose novel high-contrast coherent diffractive imaging that quantitatively analyzes the intact internal nanostructure of metastable glass-ceramics using femtosecond X-ray pulses. The immersion of sample particles in a solvent helps enhance the reconstructed image contrast and allows us to distinguish an ∼7% electron density difference between an amorphous form and crystals. Furthermore, morphological operations with a band-pass filter quantitatively elucidate the depth information. The evaluated volume ratio of the amorphous to crystalline phases is ∼2.5:1 for the measured metastable (Li

X-ray free-electron lasers (XFELs) opened up a possibility for molecular-scale single particle imaging (SPI) without the need for crystallization. In SPI experiments, the orientation of each particle has to be determined from the measured diffraction pattern. Preparing unidirectionally-aligned particles can facilitate the determination of the sample orientation. Here, we show the design principles of a liquid cell for three-dimensional imaging of unidirectionally-aligned particles in solution with XFELs. The liquid cell was designed so that neither incident X-rays nor diffracted X-rays are blocked by the substrate of the liquid cell even at high tilt angles. As a feasibility evaluation, we performed coherent diffraction measurements using the cells with a 1 μm focused XFEL beam. We successfully measured coherent diffraction patterns of a nano-fabricated metal pattern at 70° tilt angle and obtained the reconstructed image by applying iterative phase retrieval. The liquid cell will be usefully applied to molecular-scale SPI by using more tightly focused XFELs. In particular, imaging of membrane proteins embedded in lipid membranes is expected to have an enormous impact on life science and medicine.

With the emergence of X-ray free-electron lasers (XFELs), coherent diffractive imaging (CDI) has acquired a capability for single-particle imaging (SPI) of non-crystalline objects under non-cryogenic conditions. However, the single-shot spatial resolution is limited to ~5 nanometres primarily because of insufficient fluence. Here, we present a CDI technique whereby high resolution is achieved with very-high-fluence X-ray focusing using multilayer mirrors with nanometre precision. The optics can focus 4-keV XFEL down to 60 nm × 110 nm and realize a fluence of >3 × 105 J cm−2 pulse−1 or >4 × 1012 photons μm−2 pulse−1 with a tenfold increase in the total gain compared to conventional optics due to the high demagnification. Further, the imaging of fixed-target metallic nanoparticles in solution attained an unprecedented 2-nm resolution in single-XFEL-pulse exposure. These findings can further expand the capabilities of SPI to explore the relationships between dynamic structures and functions of native biomolecular complexes.

The realization of the hydrogen society, where hydrogen is used as clean and renewable energy, is desired to reduce carbon dioxide emissions and achieve sustainable development. The polymer electrolyte fuel cell (PEFC) is a key technology for automobiles in the hydrogen society as an alternative to conventional internal combustion engines. However, further improvements in PEFC performances are required for the full-scale spread of fuel cell vehicles. This study aims to image the nanostructures of the catalyst layer, which is particularly important in determining the performance of PEFCs, and correlate the observed structures with mass transfer in the catalyst layer. The catalyst layer contains catalyst-loaded carbon supports thinly covered with an ionomer responsible for proton conduction. We are especially interested in observing the support structure and ionomer coverage. We performed coherent X-ray imaging studies on the catalyst particles of PEFCs using an X-ray free-electron laser (XFEL) facility: SACLA (SPring-8 Angstrom Compact free electron LAser). Femtosecond XFEL allows us to capture radiation-damage-free snapshot images by outrunning major radiation damage processes. Damage-free imaging is of great value because radiation damage often causes a problem in high-resolution electron microscopy observation of ionomers. We used the coherent diffractive imaging (CDI) technique to observe catalyst particles of PEFCs. In CDI, sample images are reconstructed from measured coherent diffraction patterns using phase-retrieval calculation instead of objective lenses. CDI enables quantitative phase imaging and allows high-contrast imaging of the catalyst particles, which are almost transparent to X-rays. The measurement was carried out for catalyst particles in the dried condition and in solution. Our study showed that the image contrast can be adjusted by changing the electron density of the volume surrounding the sample1). The dried sample was prepared by dropping catalyst ink onto a silicon nitride membrane and air-dried. The solution sample was enclosed in micro-liquid enclosure arrays2,3) developed at Hokkaido University. The coherent diffraction patterns were measured by irradiating the sample catalyst particles with the 100-nm-focused XFEL beam with a photon energy of 4 keV using MAXIC-S (Multiple Application X-ray Imaging Chamber-S)4). The phase-retrieval calculation reconstructed the sample images. Fig. 1 shows a reconstructed image of a catalyst particle in water. The reconstructed image shows many white spots, which can be interpreted as platinum-cobalt catalysts. The pixel size of the reconstructed image is 1.3 nm, demonstrating among the highest spatial resolution in X-ray imaging. We will continue our study to observe the support structures and their ionomer coverage to understand the mass transfer in the catalyst layer. This work was supported by the FC-Platform of NEDO (New Energy and Industrial Technology Development Organization). The XFEL experiments were performed at SACLA with the approval of the Japan Synchrotron Radiation Research Institute (JASRI) (Proposal Nos. 2020A8106, 2021A8010, and 2021B8019). References: 1) A. Suzuki1, H. Tanaka, H. Yamashige, Y. Orikasa, Y. Niida, T. Kimura, K. Tono, M. Yabashi, T. Ishikawa, Y. Bessho, Y. Joti, and Y. Nishino, Femtosecond X-ray laser reveals intact sea-island structures of metastable solid-state electrolytes for batteries, submitted (2022). 2) T. Kimura, Y. Joti, A. Shibuya, C. Song, S. Kim, K. Tono, M. Yabashi, M. Tamakoshi, T. Moriya, T. Oshima, T. Ishikawa, Y. Bessho and Y. Nishino, Imaging live cell in micro-liquid enclosure by X-ray laser diffraction, Nat. Commun. 5, 3052 (2014). 3) T. Kimura, A. Suzuki, Y. Yang, Y. Niida, A. Nishioka, M. Takei, J. Wei, H. Mitomo, Y. Matsuo, K. Niikura, K. Ijiro, K. Tono, M. Yabashi, T. Ishikawa, T. Oshima, Y. Bessho, Y. Joti, and Y. Nishino, Micro-liquid enclosure array and its semi-automated assembling system for x-ray free-electron laser diffractive imaging of samples in solution, Rev. Sci. Instrum. 91, 083706 (2020). 4) H. Yumoto, T. Koyama, A. Suzuki, Y. Joti, Y. Niida, K. Tono, Y. Bessho, M. Yabashi, Y. Nishino, and H. Ohashi, High-fluence high-gain multilayer focusing optics to enhance spatial resolution in femtosecond X-ray laser imaging, submitted (2022). Figure 1

X-ray free-electron lasers (XFELs) have allowed the imaging of nanoscale samples in near-physiological conditions. To achieve three-dimensional (3D) nanostructural reconstruction, many challenges need to be addressed, such as sample delivery for data collection and data processing of noisy diffraction patterns. Here, we provided a demonstration of the 3D structure reconstruction of a gold nanoparticle from XFEL diffraction data measured at the SPring-8 Angstrom Compact Free-Electron Laser using microliquid enclosure arrays (MLEAs) sample holders. MLEAs enable in-solution measurements, however, they induce a significant amount of background noise. Thus, we performed a series of data analyses to identify the diffraction patterns suitable for 3D reconstruction as well as nonhit patterns to estimate the background noise. The background subtraction from the data significantly improved the quality of the restored structure, with the resolution estimated to be 5 nm using Fourier shell correlation. Our paper has revealed the notable potential of XFEL imaging using MLEAs in combination with the developed data-analysis protocol.

To image biological objects using coherent X-ray diffraction (CXDI), the resolution limitation is mainly resulted from insufficient photon flux at current XFEL facilities. In this report, a photon-flux master curve of particle detection is generated from single shot computer simulation of different biological particles in Protein Data Bank and EMDataBank. The master curve can be applied to estimate scatted X-ray intensity and guide the design of CXDI experiments.

We demonstrate that binary mixtures of small and large gold nanoparticles (GNPs) (5/15, 5/30, 10/30, and 15/30 nm in diameter) in the presence of a glucose-terminated fluorinated oligo(ethylene glycol) ligand can spontaneously form size-segregated assemblies. The outermost layer of the assembly is composed of a single layer of small-sized GNPs, while the larger-sized GNPs are located in the interior, forming what is referred to as a yolk/shell assembly. Time course study reveals that small and large GNPs aggregate together, and these kinetically trapped aggregations were transformed into a size-segregated structure by repeating fusions. A yolk/shell structure was directly visualized in solution by X-ray laser diffraction imaging, indicating that the structure was truly formed in solution, but not through a drying process.

We developed micro-liquid enclosure arrays (MLEAs) for holding solution samples in coherent diffractive imaging (CDI) using x-ray free-electron lasers (XFELs). Hundreds of fully isolated micro-liquid enclosures are arranged in a single MLEA chip for efficient measurement, where each enclosure is destroyed after exposure to a single XFEL pulse. A semi-automated MLEA assembling system was also developed to enclose solution samples into MLEAs efficiently at high precision. We performed XFEL-based CDI experiments using MLEAs and imaged in-solution structures of self-assembled gold nanoparticles. The sample hit rate can be optimized by adjusting solution concentration, and we achieved a single-particle hit rate of 31%, which is not far from the theoretical upper limit of 37% derived from the Poisson statistics. MELAs allow us to perform CDI measurement under controlled solution conditions and will help reveal the nanostructures and dynamics of particles in solution.

The spatial resolution of x-ray free-electron laser (XFEL) coherent diffraction imaging is currently limited by the fluence of XFELs. Here, we clarify this issue by systematically studying the diffraction with a SPring-8 angstrom compact free electron laser XFEL on gold nanoparticles of size from 10 nm to 80 nm in water solution. The coherent x-ray diffraction patterns obtained from single XFEL pulses were quantitatively analyzed using a small-angle x-ray scattering scheme along with computer simulations. The results show that the detectability of Au nanoparticles can be described by a “master curve” as a function of total electron density, particle size, and x-ray fluence. The difficulty in detecting a small particle under the current XFEL fluence, however, could be largely eliminated by the image enhancement effect through interference from a strong scattering nanoparticle nearby. We investigate this image enhancement effect by quantitatively analyzing the two-particle scattering from Au nanoparticles, and further, applying it to detect a weak biological object of influenza virus with the aid of an Au nanoparticle.

We discover the experimental case of a quantum valence criticality leading to the breakdown of the Fermi liquid state., A valence critical end point existing near the absolute zero provides a unique case for the study of a quantum version of the strong density fluctuation at the Widom line in the supercritical fluids. Although singular charge and orbital dynamics are suggested theoretically to alter the electronic structure significantly, breaking down the standard quasi-particle picture, this has never been confirmed experimentally to date. We provide the first empirical evidence that the proximity to quantum valence criticality leads to a clear breakdown of Fermi liquid behavior. Our detailed study of the mixed valence compound α-YbAlB4 reveals that a small chemical substitution induces a sharp valence crossover, accompanied by a pronounced non–Fermi liquid behavior characterized by a divergent effective mass and unusual T/B scaling in the magnetization.

To examine the efficacy and safety of tadalafil in the treatment of lower urinary tract symptoms suggestive of benign prostatic hyperplasia with chronic pelvic pain syndrome, we treated 23 Japanese men with tadalafil 5 mg once daily for 4 weeks. The mean age of the participantswas58.7 yearsand the prostate volume was25. 2 ml. Significant improvementsin total International Prostatic Symptom Score, International Prostatic Symptom Score Quality of Life Index, total National Institutes of Health Chronic Prostatitis Symptom Index score, pain subscore, urinary symptom subscore, and quality of life impact subscore, were observed for tadalafil versus before treatment. These findings confirm that tadalafil is a valuable new treatment option for patients with benign prostatic hyperplasia complicated by chronic pelvic pain syndrome.

In order to explore new applications of recovered waste paper, we prepared electrically conductive fibers by plating waste newspaper pulp (WNP) fibers. Further, we mixed them with unplated WNP fibers and filtered the mixture to obtain a conductive pulp fiber sheet, which was to be used for electromagnetic compatibility (EMC) purposes. For the plating of WNP fibers, we used an electroless nickel plating method. We also plated pulp fibers recovered from fine paper, pulp fibers recovered from milk carton, and bleached softwood kraft pulp fibers, which were used for comparison with the plated WNP fibers. All of the four types of plated, recovered waste paper pulp fibers had high conductivity, i.e., an electrical conductivity of 0.1 S/m or more and a conductance of 0.02 S or more. The conductive pulp fiber sheet made of WNP fibers had an electric field shielding effect of 30 dB or more at 10–1000 MHz, provided that the ratio of the plated WNP fibers in the sheet was 40 % or more. Therefore, our conductive WNP fiber sheet is effective in EMC.

We propose a coherent x-ray zoom condenser lens composed of two-stage deformable Kirkpatrick-Baez mirrors. The lens delivers coherent x-rays with a controllable beam size, from one micrometer to a few tens of nanometers, at a fixed focal position. The lens is suitable for diffractive and scanning microscopy. We also propose non-scanning coherent diffraction microscopy for extended objects by using an apodized focused beam produced by the lens with a spatial filter. The proposed apodized-illumination method will be useful in highly efficient imaging with ultimate storage ring sources, and will also open the way to single-shot coherent diffraction microscopy of extended objects with x-ray free-electron lasers. (C) 2013 Optical Society of America

Ultrafast time-resolved Bragg coherent X-ray diffraction (CXD) has been performed to investigate lattice dynamics in a thin crystal layer with a nanoscale thickness by using a SASE (Self-Amplified Spontaneous Emission)-XFEL (X-ray Free Electron Laser) facility, SACLA. Single-shot Bragg coherent diffraction patterns of a 100 nm-thick silicon crystal were measured in the asymmetric configuration with a grazing exit using an area detector. The measured coherent diffraction patterns showed fringes extending in the surface normal direction. By using an optical femtosecond laser-pump and the XFEL-probe, a transient broadening of coherent diffraction pattern profile was observed at a delay time of around a few tens of picosecond, indicating transient crystal lattice fluctuation induced by the optical laser. A perspective application of the time-resolved Bragg CXD method to investigate small sized grains composing ceramic materials is discussed. (C)2013 The Ceramic Society of Japan. All rights reserved.

X-ray science has greatly benefited from the progress in X-ray optics. Advances in the design and the manufacturing techniques of X-ray optics are key to the success of various microscopic and spectroscopic techniques practiced today. Here the generation of apodized X-ray illumination using a two-stage deformable Kirkpatrick–Baez mirror system is presented. Such apodized illumination is marked by the suppression of the side-lobe intensities of the focused beam. Thus generated apodized illumination was employed to improve the image quality in scanning X-ray fluorescence microscopy. Imaging of a non-isolated object by coherent X-ray diffractive imaging with apodized illumination in a non-scanning mode is also presented.

Unlike the electrostatic and electromagnetic lenses used in electron microscopy, most X-ray focusing optical systems have fixed optical parameters with constant numerical apertures (NAs). This lack of adaptability has significantly limited application targets. In the research described herein, we developed a variable-NA X-ray focusing system based on four deformable mirrors, two sets of Kirkpatrick–Baez-type focusing mirrors, in order to control the focusing size while keeping the position of the focus unchanged. We applied a mirror deformation procedure using optical/X-ray metrology for offline/online adjustments. We performed a focusing test at a SPring-8 beamline and confirmed that the beam size varied from 108 nm to 560 nm (165 nm to 1434 nm) in the horizontal (vertical) direction by controlling the NA while maintaining diffraction-limited conditions.

How a long strand of genomic DNA is compacted into a mitotic chromosome remains one of the basic questions in biology. The nucleosome fibre, in which DNA is wrapped around core histones, has long been assumed to be folded into a 30-nm chromatin fibre and further hierarchical regular structures to form mitotic chromosomes, although the actual existence of these regular structures is controversial. Here, we show that human mitotic HeLa chromosomes are mainly composed of irregularly folded nucleosome fibres rather than 30-nm chromatin fibres. Our comprehensive and quantitative study using cryo-electron microscopy and synchrotron X-ray scattering resolved the long-standing contradictions regarding the existence of 30-nm chromatin structures and detected no regular structure >11 nm. Our finding suggests that the mitotic chromosome consists of irregularly arranged nucleosome fibres, with a fractal nature, which permits a more dynamic and flexible genome organization than would be allowed by static regular structures.

How is a long strand of genomic DNA packaged into a mitotic chromosome or nucleus? The nucleosome fiber (beads-on-a-string), in which DNA is wrapped around core histones, has long been assumed to be folded into a 30-nm chromatin fiber, and a further helically folded larger fiber. However, when frozen hydrated human mitotic cells were observed using cryoelectron microscopy, no higher-order structures that included 30-nm chromatin fibers were found. To investigate the bulk structure of mitotic chromosomes further, we performed small-angle X-ray scattering (SAXS), which can detect periodic structures in noncrystalline materials in solution. The results were striking: no structural feature larger than 11 nm was detected, even at a chromosome-diameter scale (~1 μm). We also found a similar scattering pattern in interphase nuclei of HeLa cells in the range up to ~275 nm. Our findings suggest a common structural feature in interphase and mitotic chromatins: compact and irregular folding of nucleosome fibers occurs without a 30-nm chromatin structure.

An instrumentation and data analysis review of coherent diffraction microscopy at SPring-8 is given. This work will be of interest to those who want to apply coherent diffraction imaging to studies of materials science and biological samples., Since the first demonstration of coherent diffraction microscopy in 1999, this lensless imaging technique has been experimentally refined by continued developments. Here, instrumentation and experimental procedures for measuring oversampled diffraction patterns from non-crystalline specimens using an undulator beamline (BL29XUL) at SPring-8 are presented. In addition, detailed post-experimental data analysis is provided that yields high-quality image reconstructions. As the acquisition of high-quality diffraction patterns is at least as important as the phase-retrieval procedure to guarantee successful image reconstructions, this work will be of interest for those who want to apply this imaging technique to materials science and biological samples.

Introduction We examined the efficacy of combination therapy with α1-blocker tamsulosin and hypnotic zolpidem in patients who had suffered from sleep disturbance associated with nocturia. Material and methods A total of 35 patients diagnosed with nocturia with lower urinary tract symptoms (LUTS) suggestive of benign prostatic hyperplasia (BPH) were studied. After treatment with tamsulosin for 4 weeks, 16 patients dissatisfied with nocturia (nocturiaquality of life index ≥4) and suspected to have sleep disturbance (Athens Insomnia Scale ≥6) received additional treatment with tamsulosin and zolpidem for 2 weeks. Outcomes were evaluated by the International Prostate Symptom Score (IPSS) and quality of life index (QOL), Athens Insomnia Scale (AIS) and nocturia-quality of life index (nocturia-QOL). Results After monotherapy with tamsulosin, significant reductions in IPSS (18.9 ±3.8 to 9.9 ±3.0, p

Visualizing the elemental distributions of cells and tissues is of growing importance in biology and medical science because such data deepen our understanding of the behavior of metal-binding proteins and ions. Elemental mapping by X-ray fluorescence analysis with a hard X-ray nanobeam is very well suited for this purpose owing to its high sensitivity and high resolution. Using this technique, samples must be prepared without artifacts that are caused by treatments such as chemical fixation and staining procedures. In many studies of elemental mapping, sample preparation is not explicitly considered. To overcome this deficiency, we developed a cryo-scanning X-ray fluorescence microscope and installed it in the second experimental hutch of BL29XUL of SPring-8. We used it to observe frozen-hydrated cells that had been fixed by a quick-freezing technique to preserve elemental data of the living state at an X-ray energy of 11.5 keV. The distributions of K, Ca, Fe, Cu and Zn were successfully visualized. The distributions of these elements (especially those of K, Ca and Fe) differed from those in cells fixed with paraformaldehyde. Copyright © 2010 John Wiley & Sons, Ltd.

We describe a method for characterizing sub-10-nm X-ray beams using knife-edge scanning with dark-field geometry. Beam profile measurement by the conventional dark-field method is simulated numerically, and the signal intensity is found to depend strongly on the incident angle of the beam components. A numerical procedure to correct the dependence and to determine the actual beam profile is presented.

A method for evaluating the two-dimensional photon density distribution in focused hard X-ray beams is proposed and demonstrated in a synchrotron experiment at SPring-8. A synchrotron X-ray beam of 11.8 keV is focused to a ∼ 1 μ m spot by Kirkpatrick–Baez mirrors. The two-dimensional intensity distribution of the focused beam is derived by monitoring the forward diffracted intensity from an isolated silver nanocube with an edge length of ∼ 150 nm positioned in the beam waist, which is two-dimensionally scanned. Furthermore, the photon density of X-rays illuminated onto the nanocube is estimated by utilizing coherent X-ray diffraction microscopy. This method is useful for evaluating the photon density distribution of hard X-ray beams focused to a spot size of less than a few micrometers.

Coherent diffraction microscopy using highly focused hard X-ray beams allows us to three-dimensionally observe thick objects with a high spatial resolution, also providing us with unique structural information, i.e., electron density distribution, not obtained by X-ray tomography with lenses, atom probe microscopy, or electron tomography. We measured high-contrast coherent X-ray diffraction patterns of a shape-controlled Au/Ag nanoparticle and successfully reconstructed a projection and a three-dimensional image of the nanoparticle with a single pixel (or a voxel) size of 4.2 nm in each dimension. The small pits on the surface and a hollow interior were clearly visible. The Au-rich regions were identified based on the electron density distribution, which provided insight into the formation of Au/Ag nanoboxes.

To visualize the distributions of trace elements in biological samples such as tissues and cells at high spatial resolution, we developed a scanning x-ray fluorescence microscope (SXFM) at SPring-8, using a Kirkpatrick-Baez mirror optics that enables achromatic and highly efficient focusing. To evaluate performance regarding its application to biological samples, the SXFM was used at x-ray energy of 15 keV to observe NIH/3T3 cells in which adenosine triphosphate (ATP) synthase β (specifically localized at the mitochondria) were labeled with gold colloidal particles. Various elemental distributions were visualized at the single-cell level, including those for P, S, Cl, Ca, Fe, Cu, Zn and Au, and we obtained high-resolution elemental distribution maps by magnifying the labeled single mitochondrion. Maximum spatial resolution achieved in the experiments was sub-100 nm. Copyright © 2008 John Wiley & Sons, Ltd.

X-ray crystallography can routinely determine the atomic structure of crystalline materials. The method can be extended to non-crystalline materials by using coherent X-ray diffraction. In X-ray diffraction microscopy, coherent X-ray diffraction patterns are sampled finely enough to satisfy the oversampling condition for solving the phase problem, and the iterative phase retrieval method is used for the sample image reconstruction. Recently, we succeeded in three-dimensional visualization of an unstained human chromosome by X-ray diffraction microscopy. It is the first hard X-ray tomography for cellular organelles. The reconstructed images revealed the internal axial structure, demonstrating an excellent image-contrast of the method.

1-µm-thick Cu thin lines with adjacent connections, which simulate via structures in large-scale integration circuits, were fabricated on Si3N4 membranes by both electron-beam evaporation and a focused ion beam for coherent x-ray diffraction measurements. A direct current was applied to a Cu thin line to prepare an electromigration sample. In the scanning electron microscope image of the electromigration sample, a roughness of a few hundred nanometers was observed on the surface around the via structures. Coherent x-ray diffraction patterns of both the thin line and electromigration samples were measured using synchrotron x-rays at SPring-8. Characteristic diffraction patterns resulting from both the shape of the Cu thin lines and the defects around the via structures formed by the application of the current were observed. Copyright © 2008 John Wiley & Sons, Ltd.

We analyze the excitation of secondary electrons by hard-X-rays in subsurface layers. By studying core-excited photoelectron lines and their plasmon satellites in photoemission spectra, we show how electrons excited by hard-X-rays can carry information from deep regions deep within the sample to the surface. It is believed that the decay of high-energy photoelectrons via plasmon-loss is strongly related to the production of secondary electrons. For high-energy electrons, however, the momentum transfer to plasmons is small compared to the electron’s initial momentum, so the lateral position on the surface from which the secondary electrons are emitted is close to that of the atom initially excited by the hard-X-rays. This explains why the spatial resolution of hard-X-ray photoelectron emission microscope (HX-PEEM) images is good even if the buried interface is covered by a film with a thickness many times the inelastic mean free path of the primary electrons. This argument explains well recent HX-PEEM results.

The adsorption states for lubricant molecules have been investigated using hard X-ray (hν = 7.95 keV) photoemission spectroscopy (HX-PES). This method has the advantage for the organic molecules to be able to measure damage few. Being aware of the fact that P atoms exist only in cyclotriphosphazene base, we measured the take-off angle dependence of the P1s spectra. Each spectrum consists from two peaks, that is, substrate NiP peak and cyclotriphosphazene P peak. The cyclotriphosphazene P peak rapidly disappears with increasing take-off angle. We have also measured C1s spectra. Combining these experimental results, we have found that the adsorption state of cyclotriphosphazene end group is undergoing.

A novel approach to X-ray diffraction data analysis for nondestructive determination of the shape of nanoscale particles and clusters in three-dimensions is illustrated with representative examples of composite nanostructures. The technique is insensitive to the X-ray coherence, which allows 3-D reconstruction of a modal image without tomographic synthesis and in situ analysis of large (over a several cubic millimeters) volume of material with a spatial resolution of few nanometers, rendering the approach suitable for laboratory facilities.

We have studied the electronic structure of bulk single crystals and epitaxial films of magnetite Fe$_3$O$_4$. Fe $2p$ core-level spectra show clear differences between hard x-ray (HAX-) and soft x-ray (SX-) photoemission spectroscopy (PES), indicative of surface effects. The bulk-sensitive spectra exhibit temperature ($T$)-dependent charge excitations across the Verwey transition at $T_V$=122 K, which is missing in the surface-sensitive spectra. An extended impurity Anderson model full-multiplet analysis reveals roles of the three distinct Fe-species (A-Fe$^{3+}$, B-Fe$^{2+}$, B-Fe$^{3+}$) below $T_V$ for the Fe $2p$ spectra, and its $T-$dependent evolution. The Fe $2p$ HAXPES spectra show a clear magnetic circular dichroism (MCD) in the metallic phase of magnetized 100-nm-thick films. The model calculations also reproduce the MCD and identify the magnetically distinct sites associated with the charge excitations. Valence band HAXPES shows finite density of states at $E_F$ for the polaronic metal with remnant order above $T_V$, and a clear gap formation below $T_V$. The results indicate that the Verwey transition is driven by changes in the strongly correlated and magnetically active B-Fe$^{2+}$ and B-Fe$^{3+}$ electronic states, consistent with resistivity and bulk-sensitive optical spectra., Comment: 5 pages, 4 figures Accepted in Physical Review Letters

This study aims at the synthesis of Janus gold nanoparticles (Janus GNPs) with hydrophilic/hydrophobic faces by a simple ligand exchange reaction in an homogeneous system and at the elucidation of the self-assembled structures of the Janus GNPs in water. As hydrophilic surface ligands, we synthesized hexaethylene glycol (E6)-terminated thiolate ligands with C3, C7, or C11 alkyl chains, referred to as E6C3, E6C7, and E6C11, respectively. As a hydrophobic ligand, a butyl-headed thiolate ligand C4-E6C11, in which a C4 alkyl was introduced on the E6C11 terminus, was synthesized. The degree of segregation between the two ligands on the GNPs (5 nm in diameter) was examined by matrix-assisted laser desorption/ionization time-of fright mass spectrometry (MALDI-TOF MS) analysis. We found that the choice of immobilization methods, one-step or two-step addition of the two ligands to the GNP solution, crucially affects the degree of segregation. The two-step addition of a hydrophilic ligand (E6C3) followed by a hydrophobic ligand (C4-E6C11) produced a large degree of segregation on the GNPs, providing Janus-like GNPs. When dispersed in water, these Janus-like GNPs formed assemblies of ∼160 nm in diameter, whereas Domain GNPs, in which the two ligands formed partial domains on the surface, were precipitated even when the molar ratio of the hydrophilic ligand and the hydrophobic ligand on the surface of the NPs was almost 1:1. The assembled structure of the Janus-like GNPs in water was directly observed by pulsed coherent X-ray solution scattering using an X-ray free-electron laser, revealing irregular spherical structures with uneven surfaces.

We have measured Ir 4f core-level photoemission spectra using an excitation photon energy of 6 keV for single crystalline CuIr 2 S 4 at 250 and 200 K across the metal–insulator transition temperature of about 226 K . The Ir 4f spin–orbit doublet shifts by about 0.25 eV towards higher binding energy with decreasing temperature. Tails and satellites around 1 and 13 eV , respectively, higher in binding energy than the peaks of Ir 4f doublets are observed in the 250-K spectrum, but they almost disappear at 200 K . The peak analysis here done indicates that the Ir 4f spectrum at 200 K consists of two components 0.2 eV apart corresponding to the charge separation of Ir ions in CuIr 2 S 4 .

We have developed X-ray refraction-based computed tomography (CT) that is able to visualize soft tissue in between hard tissue. The experimental system consists of Si(220) diffraction double-crystals and is called the DEI (diffraction-enhanced imaging) method, in which the object is located between the crystals and a CCD camera to acquire data as 360 X-ray images. The X-ray energy used was 17.5 keV. The algorithm used to reconstruct CT images was developed by A. Maksimenko and colleagues. We successfully visualized articular cartilage and the distribution of bone marrow, which are inner structures. Our method has much higher contrast compared to the conventional absorption-based CT system.

Recently, we have shown that hard X-ray photoemission spectroscopy using undulator X-rays at SPring-8 is quite feasible with both high resolution and high throughput. Here we report an application of hard X-ray photoemission spectroscopy to the characterization of electronic and chemical states of thin solid films, for which conventional PES is not applicable. As a typical example, we focus on the problem of the scatter in the reported band-gap values for InN. We show that oxygen incorporation into the InN film strongly modifies the valence and plays a crucial role in the band gap problem. The present results demonstrate the powerful applicability of high resolution photoemission spectroscopy with hard X-rays from a synchrotron source.

PURPOSE The purpose of the present paper was to evaluate clinical factors responsible for recurrence and prognosis of superficial bladder cancer. SUBJECTS AND METHOD We reviewed date from 800 patients who were initially treated between 1991 and 2000. Recurrent and prognostic factors were examined with univariate and multivariate analysis. Kaplan-Meier Method and log rank test were used for comparing the significance of recurrence free curve and survival curve. Cox's proportional hazard model was used for univariate and multivariate analysis. A 5% level of significance was used for all statistical testing. RESULTS Of 800 cases 282 patients (35.2%) had recurrence and 27 patients (3.4%) were died in during follow up. Progression was defined as the development of muscle invasion or metastasis, progression were noted on 10 metastasis cases and 16 muscle invasion cases. Univariate analysis revealed that tumor numbers, shape, size, stage and grade were significant recurrent and prognostic factors. Multivariate analysis revealed that tumor numbers (P

We study the bulk electronic structure of Na x CoO 2 .yH 2 O using Hard X-ray (HX, h ν = 5.95 KeV) synchrotron photoelectron spectroscopy (PES). The Co 2 p core level spectra show well-separated Co 3 + and Co 4 + ions. Cluster calculations suggest low spin Co 3 + and Co 4 + character, and a moderate on-site Coulomb correlation energy U dd ∼ 3–5.5 eV. Photon-dependent valence band PES identifies Co 3 d and O 2 p derived states, in near agreement with band structure calculations. We discuss the importance of HX-PES for studying correlated transition metal oxides.

We have realized hard X-ray (HX) photoelectron spectroscopy (PES) with high-throughput and high-energy-resolution for core level and valence band studies using high-energy and high-brilliance synchrotron radiation at BL29XU in SPring-8. Large escape depth of high-energy photoelectrons enables us to probe intrinsic bulk states almost free from surface condition. By use of a newly developed electron energy analyzer and well-focused X-rays, high-energy resolution of 75 meV ( E / Δ E = 79 , 000 ) was realized for 5.95 keV photoelectrons.