The Structure of pre-Verma Modules over the N = 1 Ramond Algebra

In this note, we determine the structure of the pre-Verma modules over the N = 1 Ramond algebra. The results of this note together with the results obtained in Iohara and Koga [Adv Math 178:1–65, 2003] completely determine the structure of Verma modules over the N = 1 super Virasoro algebra both in Neveu Schwarz and Ramond sectors.     

A chip-based miniaturized format for protein-expression profiling: the exploitation of comprehensively produced antibodies

Numerous antibodies have been developed and validated in recent years, and show promise for use in novel functional protein assays. Such assays would be an alternative to pre-existing comprehensive assays, such as DNA microarrays. Antibody microarrays are thought to represent those functional protein assays. While a variety of attempts have been made to apply DNA microarray technology to antibody microarrays, a fully optimized protocol has not been established. We have been conducting a project to comprehensively produce antibodies against mouse KIAA ("KI" stands for "Kazusa DNA Research Institute" and "AA" are reference characters) proteins. Using our library of antibodies, we established a novel antibody microarray format that utilizes surface plasmon resonance (SPR) technology. A label-free real-time measurement of protein expression in crude cell lysates was achieved by direct readout of the bindings using SPR. Further refinement of the antibody microarray format enabled us to detect a smaller quantity of target proteins in the lysate without the bulk effect. In this review, we first summarize available antibody array formats and then describe the above-mentioned format utilizing updated SPR technology.     

Characterization of palladium nanoparticles by using X-ray reflectivity, EXAFS, and electron microscopy

We compared the characteristics of dodecanethiolate palladium nanoparticles synthesized by two different techniques, a one-phase method and a two-phase method. From transmission electron microscopy (TEM), we determined that the particle sizes were 46 +/- 10 angstroms and 20 +/- 5 angstroms for the one- and two-phase particles, respectively. Electron diffraction confirmed that their structure was face-centered cubic (fcc). The lattice constant a0 was 3.98 +/- 0.01 angstroms and 3.90 +/- 0.01 angstroms for the one- and two-phase particles, respectively. High-resolution TEM (HRTEM) showed that the one-phase particles had an ordered core surrounded by a disordered shell structure, while the two-phase particles appeared to be crystalline throughout. The particles were also analyzed with extended X-ray absorption fine structure (EXAFS). A cuboctahedral fcc model was used to fit the data, which implied particle sizes of less than 10 angstroms for both the one- and two-phase particles. The discrepancy between the two techniques was attributed to the presence of a disordered phase, which we presumed was composed of Pd-S compounds. Compared with the bulk palladium, lattice expansion was observed in both one- and two-phase particles by electron diffraction, HRTEM, and EXAFS. At the air/water interface, a uniform film that produced surface pressure/area isotherms could only be obtained from the two-phase particles. The one-phase particles did not wet the water surface. X-ray reflectivity data indicated that the Langmuir monolayer of the two-phase particles was only 13 angstroms thick. TEM revealed the diameter of the particles in this layer to be 23 angstroms; hence the particles assumed an oblate structure after spreading. EXAFS examination of a stack of 750 Langmuir monolayers indicated far fewer Pd-S compounds, which may have dissolved in the water. The data were consistent with a model of a monolayer of truncated cuboctahedron Pd particles that were 7 angstroms thick and 19 angstroms in diameter.     

Comparison of decanethiolate gold nanoparticles synthesized by one-phase and two-phase methods

We investigated the differences between the decanethiolate gold nanoparticles synthesized by two different routes: one-phase and two-phase methods. Their properties were compared in bulk and at the air-water interface by transmission electron microscopy (TEM), X-ray reflectivity (XR), extended X-ray absorption fine structure (EXAFS) spectroscopy, X-ray powder diffraction (XRD), thermal gravimetric analysis (TGA), time-of-flight secondary-ion mass spectrometry (TOF-SIMS), electron paramagnetic resonance (EPR), and Langmuir-Blodgett technique. The mean nanoparticles sizes obtained by EXAFS and XRD were found to be smaller than those by the TEM measurements. We explained these differences by the structural disorder and multiple twinning in the nanoparticles. The one-phase particles were found by EXAFS to be smaller and had a higher grafting density of thiol chains than the two-phase particles. We attributed these differences to the enhanced disorder of the one-phase particles. At the air-water interface, the one-phase particles did not spread, while the two-phase particles spread and formed Langmuir films. TEM and XR results revealed that the close-packed monolayer of the two-phase particles collapsed and folded into multilayer films upon further compression.     

pH-responsive, self-assembling nanoparticle from a fullerene-tagged poly(L-glutamic acid) and its superoxide dismutase mimetic property

In this study, we describe the fabrication of novel fullerene-containing peptide-nanoparticles through self-assembly. A water-soluble, poly(l-glutamic acid)-attached fullerene was newly synthesized and the conformation and self-assembling property in water were examined by using circular dichroism, FTIR, UV, atomic force microscopy, and dynamic light scattering measurements. In the lower pH region (<6.8), the fullerene peptide self-assembles into nanoparticles that are ca. 100-200 nm in diameter. These nanoparticles are rich in alpha-helices, and stacking interaction of fullerene moieties contributes to the stability of the high-order structure. In addition, these particle sizes can be easily controlled by changing pH that results in causing the conformational transition of PLGA segment. Finally, the fullerene-containing nanoparticle is confirmed to be capable of removing the biologically important superoxide radical in comparison with the superoxide dismutase.     

Miniature open channel scrubbers for gas collection

An open channel scrubber is proposed as a miniature fieldable gas collector. The device is 100 mm in length, 26 mm in width and 22 mm in thickness. The channel bottom is rendered hydrophilic and liquid flows as a thin layer on the bottom. Air sample flows atop the appropriately chosen flowing liquid film and analyte molecules are absorbed into the liquid. There is no membrane at the air-liquid interface: they contact directly each other. Analyte species collected over a 10 min interval are determined by fluorometric flow analysis or ion chromatography. A calculation algorithm was developed to estimate the collection efficiency a priori; experimental and simulated results agreed well. The characteristics of the open channel scrubber are discussed in this paper from both theoretical and experimental points of view. In addition to superior collection efficiencies at relatively high sample air flow rates, this geometry is particularly attractive that there is no change in collection performance due to membrane fouling. We demonstrate field use for analysis of ambient SO₂ near an active volcano. This is basic investigation of membraneless miniature scrubber and is expected to lead development of an excellent micro-gas analysis system integrated with a detector for continuous measurements.     

Soft-x-ray harmonic comb from relativistic electron spikes

We demonstrate a new high-order harmonic generation mechanism reaching the "water window" spectral region in experiments with multiterawatt femtosecond lasers irradiating gas jets. A few hundred harmonic orders are resolved, giving μJ/sr pulses. Harmonics are collectively emitted by an oscillating electron spike formed at the joint of the boundaries of a cavity and bow wave created by a relativistically self-focusing laser in underdense plasma. The spike sharpness and stability are explained by catastrophe theory. The mechanism is corroborated by particle-in-cell simulations.