Time variation of the electromagnetic transfer function of the earth estimated by using wavelet transform

In order to accurately estimate the geomagnetic transfer functions in the area of the volcano Mt. Iwate (IWT), we applied the interstation transfer function (ISTF) method to the three-component geomagnetic field data observed at Mt. Iwate station (IWT), using the Kakioka Magnetic Observatory, JMA (KAK) as remote reference station. Instead of the conventional Fourier transform, in which temporary transient noises badly degrade the accuracy of long term properties, continuous wavelet transform has been used. The accuracy of the results was as high as that of robust estimations of transfer functions obtained by the Fourier transform method. This would provide us with possibilities for routinely monitoring the transfer functions, without sophisticated statistical procedures, to detect changes in the underground electrical conductivity structure.     

Effect of substituent distribution on water solubility of O-methylcellulose

The effect of substituent distribution on the water solubility of O-methylcellulose (MC) was re-examined to elucidate the lower limit of the degree of substitution (DS) in water-soluble MC. To this end, a series of 2,3-MCs which are regioselectively substituted at the C-2 and C-3 hydroxyl groups were prepared by homogeneous methylation. It was found that the lower limit for the DS value of water-soluble 2,3-MC was almost the same as that for MCs having even distributions of substituents along the cellulose chain as well as in the anhydroglucose units. This revised version was published online in August 2006 with corrections to the Cover Date.     

NMR analysis of cellulose dissolved in aqueous NaOH solutions

Low molecular weight cellulose (degree of polymerization = ca 15) was dissolved in 4-- 30% NaOD/D2O, and relationships between 1H- and 13C-chemical shifts of the cellulose and NaOD concentrations were studied in terms of the dissociation of three hydroxyl groups of cellulose in aqueous NaOH solutions. All C---H proton resonances were shifted upfield linearly with an increase in the NaOD concentration, indicating that all C---H protons of cellulose undergo the electron-shielding effect by NaOH. On the other hand, the shifting patterns of carbon resonances varied among the six carbons: C1 and C4 carbons undergo the electron-shielding effect, whereas C2, C3, C5, and C6 carbons experience the electron-deshielding effect by NaOH. Changes in 13C-chemical shifts of cellulose carbons in 4--30% NaOD/D2O indicate that C3---OH has the highest resistance to dissociation in aqueous NaOH of the three hydroxyl groups of an anhydroglucose residue. It is plausible, at least from the aspects of 13C-chemical shifts, that cellulose molecules dissolving in 20--30% NaOH behave differently from those swollen in 20--30% NaOH as alkali- cellulose     

多乙酰氧基烷基(艹卓)酮和多羟基烷基(艹卓)酮的合成

各种溴代的烷基酚酮的乙酸酯用乙酸酐/三氟乙酸酐/乙酸(以下简称ATA)醋解可得高收率的相应的多乙酰氧基烷基酮,后者经稀酸水解几乎定量地得多羟基烷基酮。部分多乙酰氧基酮对肺癌A_(549)和上皮细胞癌显出抑制活性。     

ULTRAVIOLET RESONANCE RAMAN SPECTRA OF PHYTOCHROME: A COMPARISON OF THE ENVIRONMENTS OF TRYPTOPHAN SIDE CHAINS BETWEEN RED LIGHT-ABSORBING AND FAR-RED LIGHT-ABSORBING FORMS

Ultraviolet resonance Raman spectra of phytochrome in the red light-absorbing form (Pr) and the far-red light-absorbing form (Pfr) are reported. The spectra excited at 240-nm provide structural information about the protein part of phytochrome. The protein contains only a very small amount of β-sheet structure and most of the tyrosine side chains are located in hydrophobic environments. Indole rings of tryptophan (Trp) interact with neighboring groups in the Pr form and these interactions become weaker with the conversion from Pr to Pfr. Some Trp side chains of Pfr are surrounded by aliphatic groups but such is not the case in Pr. These changes in the environment occur at the same time as changes in orientation of Trp side chains. Our observations suggest that interactions between Trp residues and the tetrapyrrolic chromophore occur in the Pr form and that the strength of these interactions diminishes in the Pfr form.     

Discovery of NKT cells and development of NKT cell-targeted anti-tumor immunotherapy

Natural Killer T (NKT) cells are unique lymphocytes characterized by their expression of a single invariant antigen receptor encoded by Vα14Jα18 in mice and Vα24Jα18 in humans, which recognizes glycolipid antigens in association with the monomorphic CD1d molecule. NKT cells mediate adjuvant activity to activate both CD8T cells to kill MHC-positive tumor cells and NK cells to eliminate MHC-negative tumor at the same time in patients, resulting in the complete eradication of tumors without relapse. Therefore, the NKT cell-targeted therapy can be applied to any type of tumor and also to anyone individual, regardless of HLA type.Phase IIa clinical trials on advanced lung cancers and head and neck tumors have been completed and showed significantly prolonged median survival times with only the primary treatment. Another potential treatment option for the future is to use induced pluripotent stem cell (iPS)-derived NKT cells, which induced adjuvant effects on anti-tumor responses, inhibiting in vivo tumor growth in a mouse model.     

Three Dimensional Numerical Flow Simulation Around Parallel Rectangular Cylinders

Noises of flow around parallel rectangular cylinders are likely to be caused by wind flow. According to the wind tunnel experiment, it is known that there are three kinds of special noises. Two kinds of noises occur when the wind comes from a perpendicular direction to the cylinders. These noises are caused by the vortex excited oscillation. Another noise occurs when the wind comes from an inclined direction to the cylinders. This noise is very high frequency, and its mechanism is not clear. Therefore in this study, the three dimensional numerical flow simulation is performed to clarify the high frequency noise of flow around parallel rectangular cylinders.     

Application of the elongation method to nonlinear optical properties: finite field approach for calculating static electric (hyper)polarizabilities

A novel finite-field approach for calculating electric (hyper)polarizabilities based on the elongation method is developed. The method was tested at the semi-empirical PM3 level by using three model systems: the hydrogen chain, the water chain and polyacetylene. The results satisfactorily reproduce the ‘exact’ MOPAC values. The most important advantage of this approach is the large saving of computer time since the dimension of the SCF equation remains the same regardless of the number of atoms in the system. Thus, it is a very useful tool to treat large systems. The method can also be applied to building up a chain containing an arbitrary sequence of monomers.