Hepatitis B virus strains of subgenotype A2 with an identical sequence spreading rapidly from the capital region to all over Japan in patients with acute hepatitis B

ObjectiveTo examine recent trends of acute infection with hepatitis B virus (HBV) in Japan by nationwide surveillance and phylogenetic analyses.MethodsDuring 1991 through 2009, a sentinel surveillance was conducted in 28 national hospitals in a prospective cohort study. Genotypes of HBV were determined in 547 patients with acute hepatitis B. Nucleotide sequences in the preS1/S2/S gene of genotype A and B isolates were determined for phylogenetic analyses.ResultsHBV genotype A was detected in 137 (25% (accompanied by genotype G in one)) patients, B in 48 (9%), C in 359 (66%), and other genotypes in the remaining three (0.5%). HBV persisted in five with genotype A including the one accompanied by genotype G; another was co-infected with HIV type 1. The genotype was A in 4.8% of patients during 1991-1996, 29.3% during 1997-2002, and 50.0% during 2003-2008 in the capital region, as against 6.5%, 8.5% and 33.1%, respectively, in other regions. Of the 114 genotype A isolates, 13 (11.4%) were subgenotype A1, and 101 (88.6%) were A2, whereas of the 43 genotype B isolates, 10 (23.3%) were subgenotype B1, 28 (65.1%) were B2, two (4.7%) were B3, and three (7.0%) were B4. Sequences of 65 (64%) isolates of A2 were identical, as were three (23%) of A1, and five (18%) of B2, but none of the B1, B3 and B4 isolates shared a sequence.ConclusionsAcute infection with HBV of genotype A, subgenotype A2 in particular, appear to be increasing, mainly through sexual contact, and spreading from the capital region to other regions in Japan nationwide. Infection persisted in 4% of the patients with genotype A, and HBV strains with an identical sequence prevailed in subgenotype A2 infections. This study indicates the need for universal vaccination of young people to prevent increases in HBV infection in Japan

Prism-C2nC_2n carbon dimer, trimer, and nano-sheets: a quantum chemical study

Quantum chemical calculations have predicted the existence of a new carbon family with double-layered structures formed by arranging prism-C2n (n = 6, 8, and 12) units. Theoretical explorations of potential energy surfaces suggest the lowest barriers of the reaction channels to be ca. 30 kJ mol−1 for a D2h prism-C16 dimer and a D3h prism-C24 trimer. Geometry optimizations under periodic boundary conditions yield some prism-C2n sheets composed of CC single bonds of ca. 0.15–0.16 nm. The relative energies per one atom with respect to graphene are 90–160 kJ mol−1. Van der Waals thickness is estimated to be ca. 0.5 nm

A prism carbon molecule C20_20

A new carbon family with a prism structure has been found by quantum chemical calculations. The prism-$C_20$ has a $D_10h$ structure with double-layered decagonal rings connected each other by ten vertical CC bonds. The CC bond lengths are 0.144 nm on the decagonal rings and 0.148 nm on the side faces. The diameter of the ring is 0.465 nm. The $prism-C_20$ is expected to be stable, since the lowest energy barrier from it was estimated to be 158.0 kJ mol$^−1$

Quantum chemical exploration of dimeric forms of polycyclic aromatic hydrocarbons, naphthalene, perylene, and coronene

We have found dimeric forms of polycyclic aromatic hydrocarbon (di-PAH) molecules by quantum chemical calculations. Geometry optimization starting from short distances of ca. 0.15 nm between two PAH molecules placed in parallel gave cage structures of di-PAH with CC bond connections forming four-membered rings between the PAH molecules. The di-PAH molecules are located in sufficiently deep potential energy wells surrounded by high energy barriers, although their energies are much higher than those of the isolated two PAH molecules

Quantum chemical exploration of new π-electron systems: Capsule-formed dimers of polycyclic aromatic hydrocarbons

We have found capsule-formed dimers of polycyclic aromatic hydrocarbons (cap-di-PAH) for coronene, ovalene, and circumcoronene by quantum chemical calculations. Two monomers are connected at the edge that gives a capsule form, holding the aromatic characters in the inner six-membered rings. The aromatic π-electron networks at the upper and lower parts of the dimers are not merged each other. Those cap-di-PAHs are located in sufficiently deep potential wells surrounded by high energy barriers, indicating the high possibility of existence

High performance global exploration of isomers and isomerization channels on quantum chemical potential energy surface of H5C2NO2

High performance global exploration of isomers and isomerization channels on the quantum chemical potential energy surface (PES) is performed for H5C2NO2 by using the scaled hypersphere search‐anharmonic downward distortion following (SHS‐ADDF) method. A multi‐node operation, NeoGRRM, has achieved high performance exploration calculations for the large system by submitting SHS‐ADDF sub‐jobs into many cores in parallel and unifying the results of sub‐jobs into the total lists of the main‐job. Global exploration of equilibrium (EQ) and transition‐state structures at the level of B3LYP/6‐31G(d) gave 3210 EQs and 23278 TSs. Nine compounds were found in the low energy regions of 0–100 kJ/mol; the lowest energy compound is N‐methylcarbamic acid, the second is methyl carbamate, and the third is glycine (the most fundamental amino acid). Interconversion pathways between the conformers of each of the low energy compounds were surveyed. Isomerization channels around glycine were explored in detail. The lowest energy barriers around some of the EQs turned to be negative after zero‐point energy corrections. This indicates that those structures cannot exist as independent structures because they spontaneously collapse into more stable structures. The global PES search showed various interesting dissociating channels which indicate synthon reaction pathways in the reverse directions

Wavy carbon: a new series of carbon structures explored by quantum chemical calculations

A new carbon family adopting wavy structures has been found by quantum chemical calculations. The key motif of this family is a condensed four-membered ring. Periodically wavy-carbon sheets (wavy-Cn sheets, n = 2, 6, and 8) as well as wavy-C36 tube were found to be very similar to the previously reported prism-Cn carbon tubes (n = 5, 6, and 8) in several respects, including the relative energies per one carbon atom with respect to graphene, CC bond lengths, and CCC bond angles. Because of very high relative energies with respect to graphene (206–253 kJ mol−1), the wavy-carbons may behave as energy reserving materials