In vitro gene delivery mediated by lactosylated dendrimer (generation 3, G3)/��-cyclodextrin conjugates into hepatocytes

The purpose of this study is to evaluate in vitro gene delivery efficiency of polyamidoamine (PAMAM) starburst dendrimer (generation 3, G3) conjugates with ??-cyclodextrin (??-CDE (G3)) bearing lactose (Lac-??-CDE) with various degrees of substitution of the lactose moiety (DSL) as a novel hepatocyte-selective carrier. Lac-??-CDE (G3, DSL 1.2) was found to have much higher gene transfer activity than ??-CDE (G3), Lac-??-CDE (G2, DSL 2.6) and Lac-??-CDEs (G3, DSL 2.6, 4.1 and 6.1) in HepG2 cells, which are dependent on the expression of cell-surface asialoglycoprotein receptor (ASGP-R). Lac-??-CDE (G3, DSL 1.2) provided negligible cytotoxicity up to a charge ratio of 100 (carrier/pDNA) in HepG2 cells. These results suggest the potential use of Lac-??-CDE (G3, DSL 1.2) as a non-viral vector for gene delivery toward hepatocytes.     

A first total synthesis of a hybrid-type ganglioside associated with amyotrophic lateral sclerosis-like disorder

The hybrid ganglioside X1, which was identified in the bovine brain, was synthesized for the first time. Ganglioside X1 is believed to be involved in the development of amyotrophic lateral sclerosis-like disorders in patients with neurological disorders after treatment with bovine brain gangliosides. A convergent approach using two branched glycan units, the GM2-core trisaccharide and the lacto-ganglio tetrasaccharide, efficiently provided the highly branched heptasaccharide part of ganglioside X1, which was conjugated with the ceramide part to produce the protected ganglioside X1. Global deprotection delivered homogenous ganglioside X1, with which serum from the patient was reacted.     

The first total synthesis of ganglioside GalNAc-GD1a, a target molecule for autoantibodies in Guillain-Barré syndrome

The first synthesis of ganglioside GalNAc-GD1a, featuring efficient glycan assembly and a cyclic glucosyl ceramide as a versatile unit for ganglioside synthesis is described. Although ganglioside GalNAc-GD1a was first found as a brain ganglioside, IgG autoantibodies to GalNAc-GD1a were subsequently found to be closely related to a human peripheral-nerve disorder, Guillain-Barré syndrome, which is the commonest cause of acute flaccid paralysis worldwide. In this study, the characteristic hexasaccharide part carrying two sialic acid residues was synthesized efficiently by use of a readily accessible GM2-core unit as a common unit. The potentially difficult coupling of the oligosaccharide and ceramide moieties was carried out by using a cyclic glucosyl ceramide as a coupling partner for the hexasaccharide part, thereby successfully providing the framework of the target compound. Global deprotection delivered the homogenous ganglioside GalNAc-GD1a. An enzyme-linked immunosorbent assay showed that sera from patients with Guillain-Barré syndrome reacted both with natural and with synthetic GalNAc-GD1a.     

The effect of heterogeneous solvent systems on sonochemical reactions: accelerated degradation of alkyl thiols in emulsion

Sonochemical reactions of alkyl and aryl thiols in water–organic mixed solvent systems were kinetically investigated. The reaction in the liquid–liquid interface apparently depends on the polarities, surface activities, vapor pressures and hydrophobicities of organic solvents and thiols. Interestingly, the rate jump in sonochemical disappearance of alkyl thiols was observed under emulsified conditions.     

Asymptotics of ACH-Einstein Metrics

We study the boundary asymptotics of ACH metrics which are formally Einstein. In terms of the partially integrable almost CR structure induced on the boundary at infinity, existence and uniqueness of such formal asymptotic expansions are studied. It is shown that there always exist formal solutions to the Einstein equation if we allow logarithmic terms, and that a local CR-invariant tensor arises as the obstruction to the existence of a log-free solution. Some properties of this new CR invariant, the CR obstruction tensor, are discussed.     

Electrochemical properties of all-solid-state lithium batteries with amorphous titanium sulfide electrodes prepared by mechanical milling

Amorphous titanium trisulfide (TiS₃) active materials were prepared by ball milling of an equimolar mixture of crystalline titanium disulfide (TiS₂) and sulfur. A high-resolution transmission electron microscope image revealed no periodic lattice fringes on the amorphous TiS₃. The all-solid-state lithium secondary batteries using a sulfide solid electrolyte and the amorphous TiS₃ electrode showed high capacity of greater than 300 mAh g^?1 for 10 cycles. The amorphous TiS₃ had a higher capacity than the mixture of crystalline TiS₂ and S, which was used as the starting material of amorphous TiS₃. The X-ray diffraction patterns and the Raman spectra of the amorphous TiS₃ electrode after the first and tenth charge–discharge measurements were similar to those before the measurement. The amorphous structure of TiS₃ did not change greatly during the first few cycles. The all-solid-state cells with the amorphous TiS₃ electrode showed higher initial coulombic efficiency because the amorphous TiS₃ active material retained its structure during the initial electrochemical test.     

Electronic structures and optical absorption of multilayer graphenes

We study the electronic structures and the optical absorption spectra of the multilayer graphenes in the effective mass approximation. We decompose the Hamiltonian of graphene with an arbitrary thickness into smaller subsystems effectively identical to monolayer or bilayer graphene, and express the optical spectrum as a summation over the subsystems. We include the full band parameters which compose the bulk graphite, and closely study their effects on the band structure. We found that the particular band parameters destroying the electron–hole symmetry can affect the optical spectrum through shift of the absorption edge.     

Guest-binding properties of functionally porous crystal based on metal complex of p-tert-butylthiacalix[6]arene

A potassium salt of p-tert-butylthiacalix[6]arene shows highly-extensive coordination nature to give rise to zeolitic crystal which has huge cavity with the widest span of ca. 19 Å and is capable of crystalline phase guest-addition and -removal.