Synthesis of 1-haloethenamides from ynamide through halotrimethylsilane-mediated hydrohalogenation

A convenient synthesis of 1-haloethenamides has been achieved by utilizing halotrimethylsilane (TMSX, X = Cl, Br, I) and water. Halotrimethylsilane in 1 M CH₂Cl₂ solution functions as a halogen source of the in situ generated HX, and the HX added to the terminal triple bonds of ynamides in Markovnikov fashion.     

Antigen�Cantibody interactions of influenza virus hemagglutinin revealed by the fragment molecular orbital calculation

Effective interactions between amino acid residues in antigen?Cantibody complex of influenza virus hemagglutinin (HA) protein can be evaluated in terms of the inter-fragment interaction energy (IFIE) analysis with the fragment molecular orbital (FMO) method, in which each fragment contains the side chain of corresponding amino acid residue. We have carried out the FMO-MP2 (second-order Moeller?CPlesset) calculation for the complex of HA antigen and Fab antibody of influenza virus H3N2 A/Aichi/2/68 and obtained the IFIE values between each amino acid residue in HA and the whole antibody as the sums over the residues contained in the latter. Combining this IFIE data with experimental data for hemadsorption activity of HA mutants, we succeeded in theoretically explaining the mutations in HA observed after the emergence of influenza virus H3N2 A/Aichi/2/68 in an earlier study, except for those of THR83. In the present study, we employ an alternative way of fragment division in the FMO calculation at the carbonyl C site of the peptide bond instead of the C_?? site used in the previous work, which provides revised IFIE values consistent with all the historical mutation data in the antigenic region E of HA including the case of THR83 in the present prediction scheme for probable mutations in HA.     

Improved calculation of band gap of Sr2Bi2O5 crystal using modified Becke–Johnson exchange potential

The electronic structure of Sr₂Bi₂O₅ is calculated by the scalar-relativistic full potential linearized augmented plane wave (FLAPW+lo) method using the modified Becke–Johnson potential combined with the local density approximation correlation (MBJ–LDA). Both the valence band maximum (VBM) and conduction band minimum (CBM) exist at the Γ-point, indicating that Sr₂Bi₂O₅ is a direct-band-gap material. The band gap is calculated to be 3.17 eV, which is very close to the experimental value. This result is in great contrast to the underestimation based on the GGA calculation. On the other hand, there is only a small difference in the effective masses of holes and electrons photogenerated near the VBM and CBM for the MBJ–LDA and GGA approaches. The optical properties of Sr₂Bi₂O₅ are calculated from the complex dielectric function ε(ω)=ε₁(ω)+iε₂(ω). A highly polarized peak is observed at 3.5 eV in the ε₂(ω) function. Furthermore, the absorption coefficient estimated from the MBJ–LDA is very similar to that from the experimental result.     

Prediction of three-independent scales endowed on poliovirus proteinase 2A sequence

Mulliken's electronegativity (M) scale was found as a parameterization to predict (elucidate) a virtually specific interaction between Poliovirus proteinase 2A and mitogen-activated protein (MAP) kinase p38α, as well as that between the 2A and apoptotic protein activating factor 1c (Apaf 1c) (or prion) with intermolecular frequency symmetry (IFS) rule. Also, Lacey's hydropathical (H) scale and Garel's (G) one could be found in the specific relationship between the 2A and the extracellular signal-regulated kinase 2 (ERK2) [or fibroblast growth factor receptor 3 (FGFR3)], and that between the 2A and the c-Jun N-terminal kinase 2 (JNK2) [or forkhead box P2-1 (FOXP2-1)], respectively. Based on these, both the same physicochemical scale and almost the same resonant frequency (f) value would be conserved in the same succession of a signal transduction process in a Poliovirus-infected cell. Furthermore, the 2A could play a trigger role to cause cancer, prion disease, bone disease, or speech and language disorder.     

Reentrant nematic phase in 4-alkyl-4′-cyanobiphenyl (nCB) binary mixtures

The appearance of reentrant nematic phase was identified in nCB/8CB (n = 1–6) binary mixtures using differential scanning calorimetry, small-angle X-ray diffraction and polarising microscopy with photomonitor. Phase diagrams can roughly be unified if plotted against the average number of alkyl chain length. Distinction was recognised for the phase boundaries between nematic and smectic A phases of even and odd n of the minor component nCB. The character of 8CB as ‘SmA former’ is briefly discussed.     

High-efficiency electro-optic amplitude modulation with delayed coherent addition

Amplitude modulation of laser light is required for resonant sideband extraction employed in gravitational-wave detectors. Amplitude modulation with electro-optic phase modulators is realized by interferometric phase-to-amplitude conversion. Although two outputs modulated at opposite phases to each other are obtained, usually only one of them is utilized and the other is abandoned. The reuse of this abandoned light improves the power efficiency of the modulation. This can be realized by inverting the modulation phase of one output with a delay line and adding it to the other coherently. Moreover, this system selects a high-efficiency operating point and modulates the light in a linear range. We demonstrate that the modulation system can be operated with a power loss that is due only to the losses of the optical components.     

Challenge of advanced low temperature fuel cells based on high degree of freedom of group 4 and 5 metal oxides

To obtain an ideal electrocatalysts for hydrogen fuel cells, we investigated group 4 and 5 oxide-based compounds because of their high degree of freedom. First-principles calculations revealed that oxide surfaces such as those of titanium oxide could break down the universal scaling to achieve the ideal state of the oxygen reduction reaction. We experimentally clarified that the active sites were oxygen vacancies for tantalum and zirconium oxides, in addition to doped foreign elements and crystalline structures for titanium oxide. We successfully demonstrated that precious metal-free and carbon-free oxide-based cathodes have high quality active sites and superior durability in 0.1 M sulfuric acid at 80°C. Our strategy was developed as follows: (1) Active sites are created on the oxide surface by modifying the crystalline structure and electronic states and (2) electrons participating in the oxygen reduction reaction are supplied by nanosized oxide particles and oxide films through the tunneling effect of electrons.     

A Palladium‐Nanoparticle and Silicon‐Nanowire‐Array Hybrid: A Platform for Catalytic Heterogeneous Reactions

We report the development of a silicon nanowire array‐stabilized palladium nanoparticle catalyst, SiNA‐Pd. Its use in the palladium‐catalyzed Mizoroki‐Heck reaction, the hydrogenation of an alkene, the hydrogenolysis of nitrobenzene, the hydrosilylation of an α,β‐unsaturated ketone, and the C‐H bond functionalization reactions of thiophenes and indoles achieved a quantitative production with high reusability. The catalytic activity reached several hundred‐mol ppb of palladium, reaching a TON of 2 000 000.     

How is it possible to obtain buried interface information through very thick films using a hard-X-ray PEEM?

We analyze the excitation of secondary electrons by hard-X-rays in subsurface layers. By studying core-excited photoelectron lines and their plasmon satellites in photoemission spectra, we show how electrons excited by hard-X-rays can carry information from deep regions deep within the sample to the surface. It is believed that the decay of high-energy photoelectrons via plasmon-loss is strongly related to the production of secondary electrons. For high-energy electrons, however, the momentum transfer to plasmons is small compared to the electron’s initial momentum, so the lateral position on the surface from which the secondary electrons are emitted is close to that of the atom initially excited by the hard-X-rays. This explains why the spatial resolution of hard-X-ray photoelectron emission microscope (HX-PEEM) images is good even if the buried interface is covered by a film with a thickness many times the inelastic mean free path of the primary electrons. This argument explains well recent HX-PEEM results.