Geometric Properties of Jet Schemes

This article shows how properties of jet schemes relate to those of the singularity on the base scheme. We will see that the jet scheme's properties of being ?-factorial, ?-Gorenstein, canonical, terminal, and so on are inherited by the base scheme.     

On Hochschild Cohomology of a Self-injective Special Biserial Algebra Obtained by a Circular Quiver with Double Arrows

We calculate the dimensions of the Hochschild cohomology groups of a self-injective special biserial algebra Λ _s obtained by a circular quiver with double arrows. Moreover, we give a presentation of the Hochschild cohomology ring modulo nilpotence of Λ _s by generators and relations. This result shows that the Hochschild cohomology ring modulo nilpotence of Λ _s is finitely generated as an algebra.     

Electron-Impact Fragmentographic Fluorescence Spectroscopy of Ethanol,Acetaldehyde, 1- and 2-Propanol and Acetone

Abstract

Gaseous ethanol, acetaldehyde, 1-propanol, 2-propanol and acetone at pressures of 2 × 10^?5 to 5 × 10^?4 torr were irradiated with electrons of energies 0-1000 eV. The visible-region fluorescence of the excited fragments was then measured. Studies included pressure dependence, electron energy dependence, threshold energy measurements, and excitation curve measurements. The aim of the research was to ascertain if molecules of similar structure could be differentiated by their spectra.     

Low-Temperature Form (Phase II) of Ionic Conductor Ag7TaS6 Analyzed using High-Resolution Synchrotron X-Ray Powder Diffraction Data

Abstract

The ternary sulfide Ag₇TaS₆ displays high Ag-ion conductivity at ambient temperature, and the framework TaS₆ and Ag ions can be respectively regarded as the host structure and guest ions. Two low-temperature phases, i.e. Ag₇TaS₆ II and Ag₇TaS₆ III, were found. The Rietveld analysis of Ag₇TaS₆ II has been performed based on the X-ray data measured at 240K using a wave length 0.64997Å by a high-resolution powder diffraction instrument combined with the beam line BMlB at the European Synchrotron Radiation Facilities. Smooth convergence has been obtained (R_WP=0.066), and the crystal structure was described based on a space group Pn with monoclinic lattice constants a=7.4462, b=7.4013, c=10.5296Å and β=90.069°. The narrow widths of reflections even at high angle have made possible the analysis of individual thermal parameters for Ag ions. In Ag₇TaS₆ II, Ag-Ag linkage rather than Ag-S coordination seem to affect the thermal parameters of Ag ions. The guest-guest interaction can be important for mobility of guest ions in the ionic conductor.     

Sensitivity enhancement in solid state (15)N NMR by indirect detection with high-speed magic angle spinning

Enhancement of sensitivity in solid state (15)N NMR by indirect detection through (1)H NMR signals under high-speed magic angle spinning and high-field conditions is demonstrated experimentally on two (15)N-labeled peptides, polycrystalline AlaGlyGly and the helix-forming, 17-residue peptide MB(i + 4)EK in lyophilized form. Sensitivity enhancement factors ranging from 2.0 to 3.2 are observed experimentally, depending on the (15)N and (1)H linewidths and polarization transfer efficiencies. The (1)H-detected two-dimensional (1)H/(15)N correlation spectrum of AlaGlyGly illustrates the possibility of increased spectral resolution and resonance assignments in indirectly detected experiments, in addition to the sensitivity enhancement.     

Study on selective separation of cesium from high level liquid waste using a macroporous silica-based supramolecular recognition absorbent

A macroporous silica-based supramolecular recognition absorbent (Calix[4]?+?Dodecanol)/SiO₂?CP, was prepared by successive impregnation and fixing the 1,3-[(2,4-diethylheptylethoxy)oxy]-2,4-crown-6-Calix[4]arene (Calix[4]arene-R14) and its molecule modifier 1-Dodecanol onto SiO₂ silica-based polymer support. The characterization of (Calix[4]?+?Dodecanol)/SiO₂?CP was examined by thermal gravimetry and differential thermal analysis and electron probe microanalysis. Relatively large separation factors of Cs and other metal ions (?? _Cs/M ⁿ⁺ ) above 60 were obtained in the presence of 3?M HNO₃. The adsorption data of Cs(I) fitted well with Langmuir isotherm and the maximum adsorption capacity was estimated to be 0.19?mmol?g^?1. The Cs(I) in 3?M HNO₃ were also effectively adsorption on (Calix[4]?+?Dodecanol)/SiO₂?CP in the column operation, and the loaded Cs(I) was successfully eluted with an eluent of H₂O. The column packed with (Calix[4]?+?Dodecanol)/SiO₂?CP had excellent reusability after three cycles.     

Revealing protein structures in solid-phase peptide synthesis by 13C solid-state NMR: evidence of excessive misfolding for Alzheimer's β

Solid-phase peptide synthesis (SPPS) is a widely used technique in biology and chemistry. However, the synthesis yield in SPPS often drops drastically for longer amino acid sequences, presumably because of the occurrence of incomplete coupling reactions. The underlying cause for this problem is hypothesized to be a sequence-dependent propensity to form secondary structures through protein aggregation. However, few methods are available to study the site-specific structure of proteins or long peptides that are anchored to the solid support used in SPPS. This study presents a novel solid-state NMR (SSNMR) approach to examine protein structure in the course of SPPS. As a useful benchmark, we describe the site-specific SSNMR structural characterization of the 40-residue Alzheimer's β-amyloid (Aβ) peptide during SPPS. Our 2D (13)C/(13)C correlation SSNMR data on Aβ(1-40) bound to a resin support demonstrated that Aβ underwent excessive misfolding into a highly ordered β-strand structure across the entire amino acid sequence during SPPS. This approach is likely to be applicable to a wide range of peptides/proteins bound to the solid support that are synthesized through SPPS.     

Hydrogel microrobots actuated by optically generated vapour bubbles

A novel hydrogel microrobot made of poly(ethylene glycol) diacrylate (PEGDA) is reported. This disk-shaped microrobot is optothermally actuated by laser-induced bubbles. A pulsed laser is used to smoothly actuate an 80-μm-diameter bubble microrobot at up to 320 μm s(-1). A single microrobot or a pair of microrobots working in cooperation were used to assemble 20-μm-diameter polystyrene beads into different patterns. The microrobots were also used to assemble patterns made of single yeast cells and cell-laden agarose microgels. The patterned yeast cells and cell-laden microgels were cultured, and the cells successfully multiplied.     

Deterioration of bulk heterojunction organic photovoltaic devices by a minute amount of oxidized fullerene

A chemical model of deterioration of a bulk heterojunction organic solar cell containing a photooxidized product of 1,4-bis(dimethylphenylsilylmethyl)[60]fullerene suggests that molecular oxygen degrades device performance by two mechanisms.     

Isolation and characterization of phenolic antioxidants from Plantago herb

Seven phenolic compounds, including a new phenylethanoid glycoside, were isolated from the ethyl acetate fraction of an aqueous ethanol extract of Plantago Herb (whole part of Plantago asiatica L.), which showed significant antioxidative activity. The new compound was characterized as 2-(3,4-dihydroxyphenyl)ethyl 3-O-β-D-allopyranosyl-6-O-caffeoyl-β-D-glucopyranoside on the basis of spectral and chemical evidence, and its antioxidant activity was comparable to that of tea catechins.