Simulations of Surface X-ray Diffraction from a Monolayer 4He Film Adsorbed on Graphite

We carried out simulations of crystal truncation rod (CTR) scatterings, i.e., one of the surface X-ray diffraction techniques with atomic resolution, from a monolayer He film adsorbed on graphite. Our simulations reveal that the 00L rod scatterings from the He monolayer exhibit notable intensity modifications for those from a graphite surface in the ranges of approximately L = 0.6 - 1.7 and L = 2.2 - 3.5. The height of the He monolayer from the graphite surface largely affects the CTR scattering profiles, indicating that CTR scatterings have enough sensitivities to determine the surface structure of the various phases in the He layer. In particular, in the incommensurate solid phase, our preliminary experimental data show the intensity modulations that are expected from the present simulations.Comment: 6 pages, 4 figures, to be published in JPS Conf. Pro

Comparative transcriptomic characterization of aluminum, sodium chloride, cadmium and copper rhizotoxicities in Arabidopsis thaliana

Abstract Background Rhizotoxic ions in problem soils inhibit nutrient and water acquisition by roots, which in turn leads to reduced crop yields. Previous studies on the effects of rhizotoxic ions on root growth and physiological functions suggested that some mechanisms were common to all rhizotoxins, while others were more specific. To understand this complex system, we performed comparative transcriptomic analysis with various rhizotoxic ions, followed by bioinformatics analysis, in the model plant Arabidopsis thaliana. Results Roots of Arabidopsis were treated with the major rhizotoxic stressors, aluminum (Al) ions, cadmium (Cd) ions, copper (Cu) ions and sodium (NaCl) chloride, and the gene expression responses were analyzed by DNA array technology. The top 2.5% of genes whose expression was most increased by each stressor were compared with identify common and specific gene expression responses induced by these stressors. A number of genes encoding glutathione-S-transferases, peroxidases, Ca-binding proteins and a trehalose-synthesizing enzyme were induced by all stressors. In contrast, gene ontological categorization identified sets of genes uniquely induced by each stressor, with distinct patterns of biological processes and molecular function. These contained known resistance genes for each stressor, such as AtALMT1 (encoding Al-activated malate transporter) in the Al-specific group and DREB (encoding dehydration responsive element binding protein) in the NaCl-specific group. These gene groups are likely to reflect the common and differential cellular responses and the induction of defense systems in response to each ion. We also identified co-expressed gene groups specific to rhizotoxic ions, which might aid further detailed investigation of the response mechanisms. Conclusion In order to understand the complex responses of roots to rhizotoxic ions, we performed comparative transcriptomic analysis followed by bioinformatics characterization. Our analyses revealed that both general and specific genes were induced in Arabidopsis roots exposed to various rhizotoxic ions. Several defense systems, such as the production of reactive oxygen species and disturbance of Ca homeostasis, were triggered by all stressors, while specific defense genes were also induced by individual stressors. Similar studies in different plant species could help to clarify the resistance mechanisms at the molecular level to provide information that can be utilized for marker-assisted selection.</p

Comparative transcriptomic characterization of aluminum, sodium chloride, cadmium and copper rhizotoxicities in Arabidopsis thaliana

<p>Abstract</p> <p>Background</p> <p>Rhizotoxic ions in problem soils inhibit nutrient and water acquisition by roots, which in turn leads to reduced crop yields. Previous studies on the effects of rhizotoxic ions on root growth and physiological functions suggested that some mechanisms were common to all rhizotoxins, while others were more specific. To understand this complex system, we performed comparative transcriptomic analysis with various rhizotoxic ions, followed by bioinformatics analysis, in the model plant <it>Arabidopsis thaliana</it>.</p> <p>Results</p> <p>Roots of <it>Arabidopsis </it>were treated with the major rhizotoxic stressors, aluminum (Al) ions, cadmium (Cd) ions, copper (Cu) ions and sodium (NaCl) chloride, and the gene expression responses were analyzed by DNA array technology. The top 2.5% of genes whose expression was most increased by each stressor were compared with identify common and specific gene expression responses induced by these stressors. A number of genes encoding glutathione-S-transferases, peroxidases, Ca-binding proteins and a trehalose-synthesizing enzyme were induced by all stressors. In contrast, gene ontological categorization identified sets of genes uniquely induced by each stressor, with distinct patterns of biological processes and molecular function. These contained known resistance genes for each stressor, such as <it>AtALMT1 </it>(encoding Al-activated malate transporter) in the Al-specific group and <it>DREB </it>(encoding dehydration responsive element binding protein) in the NaCl-specific group. These gene groups are likely to reflect the common and differential cellular responses and the induction of defense systems in response to each ion. We also identified co-expressed gene groups specific to rhizotoxic ions, which might aid further detailed investigation of the response mechanisms.</p> <p>Conclusion</p> <p>In order to understand the complex responses of roots to rhizotoxic ions, we performed comparative transcriptomic analysis followed by bioinformatics characterization. Our analyses revealed that both general and specific genes were induced in <it>Arabidopsis </it>roots exposed to various rhizotoxic ions. Several defense systems, such as the production of reactive oxygen species and disturbance of Ca homeostasis, were triggered by all stressors, while specific defense genes were also induced by individual stressors. Similar studies in different plant species could help to clarify the resistance mechanisms at the molecular level to provide information that can be utilized for marker-assisted selection.</p

Redox oscillations in 18650-type lithium-ion cell revealed by in operando Compton scattering imaging

Compton scattering imaging using high-energy synchrotron x rays allows the visualization of the spatiotemporal lithiation state in lithium-ion batteries probed in operando. Here, we apply this imaging technique to the commercial 18650-type cylindrical lithium-ion battery. Our analysis of the line shapes of the Compton scattering spectra taken from different electrode layers reveals the emergence of inhomogeneous lithiation patterns during the charge-discharge cycles. Moreover, these patterns exhibit oscillations in time where the dominant period corresponds to the timescale of the charging curve.Peer reviewe

High-Energy X-Ray Compton Scattering Imaging of 18650-Type Lithium-Ion Battery Cell

High-energy synchrotron X-ray Compton scattering imaging was applied to a commercial 18650-type cell, which is a cylindrical lithium-ion battery in wide current use. By measuring the Compton scattering X-ray energy spectrum non-destructively, the lithiation state in both fresh and aged cells was obtained from two different regions of the cell, one near the outer casing and the other near the center of the cell. Our technique has the advantage that it can reveal the lithiation state with a micron-scale spatial resolution even in large cells. The present method enables us to monitor the operation of large-scale cells and can thus accelerate the development of advanced lithium-ion batteries

Development and analytical performance evaluation of an automated chemiluminescent immunoassay for pro-gastrin releasing peptide (ProGRP)

Background: Pro-gastrin releasing peptide ( ProGRP) concentrations in blood play an important role in the diagnosis and treatment of patients with small cell lung cancer (SCLC). The automated quantitative ARCHITECT (R) ProGRP assay was developed to aid in the differential diagnosis and in the management of SCLC. The purpose of this study was to evaluate the analytical performance of this chemiluminescent microparticle immunoassay at multiple sites. Methods: ARCHITECT ProGRP measures ProGRP using a two-step sandwich using monoclonal anti-ProGRP antibodies coated on paramagnetic microparticles and labeled with acridinium. Analytical performance of the assay was evaluated at four sites: Abbott Japan, Denka Seiken, the Johns Hopkins University, and the University of Munich. Results: Total precision (%CV) for nine analyte concentrations was between 2.2 and 5.7. The analytical sensitivity of the assay was between 0.20 pg/mL and 0.88 pg/mL. The functional sensitivity at 20% CV was between 0.66 pg/mL and 1.73 pg/mL. The assay was linear up to 50,000 pg/mL using a 1:10 autodilution protocol. The calibration curve was stable for 30 days. Comparison with the Fujirebio microtiter plate enzyme-linked immunosorbent assay (EIA) ProGRP assay gave a slope of 0.93 and a correlation coefficient (r) of 0.99. Conclusions: These results demonstrate that the ARCHITECT ProGRP assay has excellent sensitivity, precision, and correlation to a reference method. This assay provides a convenient automated method for ProGRP measurement in serum and plasma in hospitals and clinical laboratories. Clin Chem Lab Med 2009;47:1557-63

Meson mixing amplitudes in asymmetric nuclear matter

Using a purely hadronic model, we study the charge-symmetry-breaking $\rho$-$\omega$, $\sigma$-$\delta$, $\sigma$-$\rho$ and $\delta$-$\omega$ mixing amplitudes in isospin asymmetric nuclear matter. The basic assumption of the model is that the mixing amplitude is generated by nucleon and anti-nucleon loops and hence driven entirely by the difference between proton and neutron Fermi momenta and the proton-neutron mass difference. We find that the behavior of the mixing amplitude is very complicated in the spacelike region and quite sensitive to the proton fraction of nuclear medium and nuclear density. In particular, in neutron rich nuclei (like Pb) and/or neutron stars the mixing amplitudes become about 10 $\sim$ 100 times as large as those in typical mirror nuclei.Comment: 13 pages, 9 ps figure