An energy-conserving Galerkin scheme for a class of nonlinear dispersive equations

A Galerkin scheme is presented for a class of conservative nonlinear dispersive equations, such as the Camassa–Holm equation and the regularized long wave equation. The scheme has two advantageous features: first, it is conservative in that it keeps the discrete analogue of the continuous energy conservation property in the original equations; second, it can be formulated only with cheap H¹$H^1$-elements even if the original equations include third derivative u_xxx$u_{\mathit{xxx}}$. Numerical experiments confirm the stability and effectiveness of the proposed scheme.     

Thallium selenate (Tl2SeO4) in a paraelastic phase by X‐ray powder diffraction

The structure of thallium selenate, Tl₂SeO₄, in a paraelastic phase (above 661 K) has been analysed by Rietveld analysis of the X‐ray powder diffraction pattern. Atomic parameters based on the isomorphic K₂SO₄ crystal in the paraelastic phase were used as the starting model. The structure was determined in the hexagonal space group P6₃/mmc, with a = 6.2916 (2) Å and c = 8.1964 (2) Å. From the Rietveld refinement it was found that two orientations are possible for the SeO₄ tetrahedra, in which one of their apices points randomly up and down with respect to [001]. One Tl atom lies at the origin with symmetry, the other Tl and one of the O atoms occupy sites with 3m symmetry, the Se atom is at a site with symmetry and the remaining O atom is at a site with m symmetry. Furthermore, it was also found that the Tl atoms display anomalously large positional disorder along [001] in the paraelastic phase.     

Production mechanism of proepitheaflagallin, a precursor of benzotropolone-type black tea pigment, derived from epigallocatechin via a bicyclo[3.2.1]octane-type intermediate

An unstable intermediate proepitheaflagallin B (2), a precursor of proepitheaflagallin (3), was isolated as an enzymatic oxidation product of (−)-epigallocatechin (1), and the structure of 2 was determined based on spectroscopic data. The structure and its decomposition revealed that the detailed production mechanism of proepitheaflagallin (3) via a bicyclo[3.2.1]octane-type intermediate was related to that of major black tea pigments, theaflavins.     

Efficient formation of giant liposomes through the gentle hydration of phosphatidylcholine films doped with sugar

Giant liposomes, or giant vesicles, are cell-size (approximately 5-100 microm) compartments enclosed with phospholipid bilayers, and have often been used in biological research. They are usually generated using hydration methods, "electroformation" and "gentle hydration (or natural swelling)", in which dry lamellar films of phospholipids are hydrated with aqueous solutions. In gentle hydration, however, giant liposomes are difficult to prepare from an electrostatically neutral phospholipid because lipid lamellae cannot repel each other. In this study, we demonstrate the efficient formation of giant liposomes using the gentle hydration of neutral phospholipid (dioleoyl phosphatidylcholine, DOPC) dry films doped with nonelectrolytic monosaccharides (glucose, mannose, and fructose). A mixture of DOPC and such a sugar in an organic solvent (chloroform/methanol) was evaporated to form the films, which were then hydrated with distilled water or Tris buffers containing sodium chloride. Under these conditions, giant liposomes spontaneously formed rapidly and assumed a swollen cell-sized spherical shape with low lamellarity, whereas giant liposomes from pure DOPC films had multilamellar lipid layers, miscellaneous shapes and smaller sizes. This observation indicates that giant unilamellar vesicles (GUVs) of DOPC can be obtained efficiently through the gentle hydration of sugar-containing lipid dry films because repulsion between lipid lamellae is enhanced by the osmosis induced by dissolved sugar.     

Matrix-free high-resolution imaging mass spectrometry with high-energy ion projectiles

The importance of imaging mass spectrometry (MS) for visualizing the spatial distribution of molecular species in biological tissues and cells is growing. We have developed a new system for imaging MS using MeV ion beams, termed MeV-secondary ion mass spectrometry (MeV-SIMS) here, and demonstrated more than 1000-fold increase in molecular ion yield from a peptide sample (1154 Da), compared to keV ion irradiation. This significant enhancement of the molecular ion yield is attributed to electronic excitation induced in the near-surface region by the impact of high energy ions. In addition, the secondary ion efficiency for biologically important compounds (>1 kDa) increased to more than 10(10) cm(-2), demonstrating that the current technique could, in principle, achieve micrometer lateral resolution. In addition to MeV-SIMS, peptide compounds were also analyzed with cluster-SIMS and the results indicated that in the former method the molecular ion yields increased substantially compared to the latter. To assess the capability of MeV-SIMS to acquire heavy-ion images, we have prepared a micropatterned peptide surface and successfully obtained mass spectrometric imaging of the deprotonated peptides (m/z 1153) without any matrix enhancement. The results obtained in this study indicate that the MeV-SIMS technique can be a powerful tool for high-resolution imaging in the mass range from 100 to over 1000 Da.     

Synthesis and structural, electrochemical, and stacking properties of conical molecules possessing buckyferrocene on the apex

A series of conical molecules featuring a [60]fullerene/ferrocene hybrid and five aralkyl side chains (Fe[C60{C6H4-(OCO-C6H3-(OR)2-3,4)-4}5]Cp) have been synthesized and examined for their structural and electrochemical properties as well as their ability to form supramolecular structures in crystals and liquid crystals. When the R group on the side is a methyl group, the compound forms crystals in which the dipolar conical molecules are stacked head-to-tail to form a columnar structure. When the R group is as long as a C18H38 group, the compound forms liquid crystals. Oxidation of the liquid crystalline compound by an aminium salt [(4-BrC6H4)3N][SbCl6] produces the corresponding paramagnetic Fe(III) compound that also exhibits liquid crystalline properties.     

A new fluorescent probe for zinc(II): an 8-hydroxy-5-N,N-dimethylaminosulfonylquinoline-pendant 1,4,7,10-tetraazacyclododecane

A new fluorescent probe for Zn2+, namely, 8-hydroxy-5-N,N-dimethylaminosulfonylquinolin-2-ylmethyl-pendant cyclen (L8), was designed and synthesized (cyclen=1,4,7,10-tetraazacyclododecane). By potentiometric pH, 1H NMR, and UV spectroscopic titrations, the deprotonation constants pKa1-pKa6 of L(8)4 HCl were determined to be <2, <2, <2 (for amino groups of the cyclen and quinoline moieties), 7.19+/-0.05 (for 8-OH of the quinoline moiety), 10.10+/-0.05, and 11.49+/-0.05, respectively, at 25 degrees C with I=0.1 (NaNO3). The results of 1H NMR, potentiometric pH, and UV titrations, as well as single-crystal X-ray diffraction analysis, showed that L8 and Zn2+ form a 1:1 complex [Zn(H-1L8)], in which the 8-OH group of the quinoline ring of L8 is deprotonated and coordinates to Zn2+, in aqueous solution at neutral pH. On addition of one equivalent of Zn2+ and Cd2+, the fluorescence emission of L8 (5 microM) at 512 nm in aqueous solution at pH 7.4 [10 mM HEPES with I=0.1 (NaNO3)] and 25 degrees C increased by factors of 17 and 43, respectively. We found that the cyclen moiety has the unique property of quenching the fluorescence emission of the quinolinol moiety when not complexed with metal cations, but enhancing emission when complexed with Zn2+ or Cd2+. In addition, the Zn2+-L8 complex [Zn(H-1L8)] is much more thermodynamically and kinetically stable (Kd{Zn(H-1L8)}=[Zn2+]free[L8]free/[Zn(H-1L8)]=8 fM at pH 7.4) than the Zn2+ complexes of our previous Zn2+ fluorophores ([Zn(H-1L2)] and [Zn(L3)]). Furthermore, formation of [Zn(H-1L8)] is much faster than those of [Zn(H-1L2)] and [Zn(L3)]. The staining of early-stage apoptotic cells with L8 is also described.     

An anion-exchange chromatographic study on boron isotopic fractionation at 2 MPa at 293 K

To study boron isotopic fractionation at high pressure, column chromatography operated in the breakthrough manner was performed at 2.0 MPa at 25.0 degrees C. The fractionation factor (S) between boron adsorbed onto strongly basic anion-exchange resin and boron in solution was obtained as 1.013, which was smaller than the values at 0.1 MPa (atmospheric pressure) found in literature. The pressure dependence of S was discussed based on the polymerization of boron in the solution and resin phases and on the occurrence of the pressure dependent isotope effect relating to the molar volume changes of boron species upon isotope substitution.     

Exact solution for in-plane static problems of circular beams made of functionally graded materials

Exact analytical solutions of in-plane static problems of circular beams with uniform cross-section made of functionally graded material (FGM) are obtained. Material properties are assumed to be varying arbitrarily through the thickness. The effects of axial extension and shear deformations are considered. The differential equation system is solved exactly using the initial values method. The circumferential stress distribution on the cross-section is also obtained. The results are compared with those of rather complex approaches in the literature, such as elasticity approach, and the comparison shows an excellent agreement. Effects of power law exponent and radius-to-height ratio of the beam on circumferential stress distribution and displacements are investigated.     

Facile synthesis of biphenyl-fused BODIPY and its property

A biphenyl-fused BODIPY was synthesized through a facile oxidative cyclization of peripheral aryl-substituents at the β-position of the BODIPY unit. The extended π-system of the fused BODIPY induces near-infrared (NIR) absorption and strong π-π interactions in the solid state. These features are beneficial for the application of the dye as a functional material. The biphenyl-fused BODIPY dye was demonstrated to exhibit photocurrent conversion ability on the basis of its n-type semiconducting property.