Porphyrin Arch-Tapes: Synthesis, Contorted Structures, and Full Conjugation

Fukui, Norihito,Kim, Taeyeon,Kim, Dongho,Osuka, Atsuhiro American Chemical Society 2017 JOURNAL OF THE AMERICAN CHEMICAL SOCIETY - Vol.139 No.26

<P>Porphyrin tapes possessing meso-meso beta-beta beta-beta triple direct linkages have been targets of extensive studies because of their fully conjugated characteristic pi-electronic networks. In this paper, we report porphyrin arch tapes that bear additional carbonyl group(s) or methylene group(s) inserted between one of the beta-beta linkage(s) of the porphyrin tapes. The carbonyl-inserted porphyrin arch-tapes were efficiently synthesized by double fusion reactions of beta-to-beta carbonyl-bridged porphyrin oligomers with DDQ and Sc(OTf)(3), and were converted to the methylene-bridged porphyrin arch-tapes via Luche reduction with NaBH4 and CeCl3 followed by ionic hydrogenation with HBF4 center dot OEt2 and BH3 center dot NEt3. While the conventional porphyrin tapes display rigid and planar structures and low solubilities, these porphyrin arch-tapes show remarkably contorted structures, flexible conformations, and improved solubilities because of the presence of the incorporated seven-membered ring(s). Interestingly, the methylene inserted arch-tapes exhibited conjugative electronic interactions that were comparable to those of porphyrin tapes probably owing to through-space interaction in the contorted conformations. The carbonyl-inserted arch-tapes displayed distinctly larger conjugative interactions owing to an active involvement of the carbonyl group(s) in the electronic conjugation. A similar trend was observed in the nonlinear optical properties, as evidenced by their two-photon absorption cross sections. Furthermore, as a benefit of the contorted structures, these porphyrin arch-tapes can catch C-60 fullerene effectively. Naturally, the electron-rich methylene-bridged arch-tapes exhibited larger association constants than the electron-deficient carbonyl-bridged arch-tapes. Among these arch-tapes, a methylene-bridged syn-Ni(II) porphyrin trimer recorded the largest association constant of (1.5 +/- 0.4) X 10(7) M-1 in toluene at 25 degrees C.</P>

Echolocation Call Structure of Fourteen Bat Species in Korea

Fukui, Dai,Hill, David A.,Kim, Sun-Sook,Han, Sang-Hoon The Korean Society of Systematic Zoology 2015 Animal Systematics, Evolution and Diversity Vol.31 No.3

The echolocation calls of bats can provide useful information about species that are generally difficult to observe in the field. In many cases characteristics of call structure can be used to identify species and also to obtain information about aspects of the bat's ecology. We describe and compare the echolocation call structure of 14 of the 21 bat species found in Korea, for most of which the ecology and behavior are poorly understood. In total, 1,129 pulses were analyzed from 93 echolocation call sequences of 14 species. Analyzed pulses could be classified into three types according to the pulse shape: FM/CF/FM type, FM type and FM/QCF type. Pulse structures of all species were consistent with previous studies, although geographic variation may be indicated in some species. Overall classification rate provided by the canonical discriminant analysis was relatively low. Especially in the genera Myotis and Murina, there are large overlaps in spectral and temporal parameters between species. On the other hand, classification rates for the FM/QCF type species were relatively high. The results show that acoustic monitoring could be a powerful tool for assessing bat activity and distribution in Korea, at least for FM/QCF and FM/CF/FM species.

Effect of Bead Device Diameter on Z-Resolution Measurement in Tomosynthesis Images: A Simulation Study

Fukui Ryohei,Miho Numata,Saki Nishioka,Ryutarou Matsuura,Katsuhiro Kida,Sachiko Goto 한국의학물리학회 2022 의학물리 Vol.33 No.4

Purpose: To clarify the relationship between the diameter of the simulated bead and the Z-resolution of the tomosynthesis image. Methods: A simulated bead was placed on a 1,024×1,024×1,024-pixel base image. The diameters were set to 0.025, 0.05, 0.1, 0.2, 0.3, 0.7, 1.0, and 1.3 mm. A bead was placed at the center of the base image and projected at a simulated X-ray angle range of ±45° to obtain a projected image. A region of interest was placed at the center of the bead image and the slice sensitivity profile (SSP) was obtained by acquiring pixel values in the z-direction. The full width at half maximum of the SSP was defined as the Z-resolution and the frequency response was obtained by the 1-D Fourier transform of the SSP. Results: Z-resolution increased with increasing bead diameter. However, there was no change in Z-resolution between 0.025 and 0.1 mm. The frequency response was similar to that of the Z-resolution, with a significant difference between 0.1 and 0.2 mm diameter. Conclusions: Z-resolution is dependent on the diameter of the bead, which should be selected considering the pixel size of the tomosynthesis image.

EPA, an omega‐3 fatty acid, induces apoptosis in human pancreatic cancer cells: Role of ROS accumulation, caspase‐8 activation, and autophagy induction

Fukui, Masayuki,Kang, Ki Sung,Okada, Kazushi,Zhu, Bao Ting Wiley Subscription Services, Inc., A Wiley Company 2013 Journal of cellular biochemistry Vol.114 No.1

<P><B>Abstract</B></P><P>In a recent study, we showed that eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), two common omega‐3 fatty acids, can cause ROS accumulation and subsequently induce caspase‐8‐dependent apoptosis in human breast cancer cells (Kang et al. [2010], PLoS ONE 5: e10296). In this study, we showed that the pancreas has a unique ability to accumulate EPA at a level markedly higher than several other tissues analyzed. Based on this finding, we sought to further investigate the anticancer actions of EPA and its analog DHA in human pancreatic cancer cells using both in vitro and in vivo models. EPA and DHA were found to induce ROS accumulation and caspase‐8‐dependent cell death in human pancreatic cancer cells (MIA‐PaCa‐2 and Capan‐2) in vitro. Feeding animals with a diet supplemented with 5% fish oil, which contains high levels of EPA and DHA, also strongly suppresses the growth of MIA‐PaCa‐2 human pancreatic cancer xenografts in athymic nude mice, by inducing oxidative stress and cell death. In addition, we showed that EPA can concomitantly induce autophagy in these cancer cells, and the induction of autophagy diminishes its ability to induce apoptotic cell death. It is therefore suggested that combination of EPA with an autophagy inhibitor may be a useful strategy in increasing the therapeutic effectiveness in pancreatic cancer. J. Cell. Biochem. 114: 192–203, 2012. © 2012 Wiley Periodicals, Inc.</P>

Highly planar diarylamine-fused porphyrins and their remarkably stable radical cations

Fukui, N.,Cha, W.,Shimizu, D.,Oh, J.,Furukawa, K.,Yorimitsu, H.,Kim, D.,Osuka, A. THE ROYAL SOCIETY OF CHEMISTRY 2017 Chemical science Vol.8 No.1

<P>Oxidative fusion reactions of meso-phenoxazino Ni(II) porphyrin were found to be temperature dependent, giving rise to either a doubly phenylene-fused product at room temperature or a singly phenoxazine-fused product at 70 degrees C. The latter was further oxidized to a doubly phenoxazine-fused Ni(II) porphyrin, which was subsequently converted to the corresponding free base porphyrin and Zn(II) porphyrin. Compared to previously reported diphenylamine-fused porphyrins that displayed a molecular twist, doubly phenoxazine-fused porphyrins exhibited distinctly different properties owing to their highly planar structures, such as larger fluorescence quantum yields, formation of an offset face-to-face dimer both in solution and the solid state, and the generation of a mixed-valence p-radical cation dimer upon electrochemical oxidation. One-electron oxidation of the phenoxazine-fused Ni(II) porphyrin with Magic Blue gave the corresponding radical cation, which was certainly stable and could be isolated by separation over a silica gel column but slowly chlorinated at the reactive beta-positions in the solid state. This finding led to us to examine beta, beta'-dichlorinated phenoxazine-fused and diphenylamine-fused Ni(II) porphyrins, which, upon treatment with Magic Blue, provided remarkably stable radical cations to an unprecedented level. It is actually possible to purify these radical cations by silica gel chromatography, and they can be stored for over 6 months without any sign of deterioration. Moreover, they exhibited no degradation even after the CH2Cl2 solution was washed with water. However, subtle structural differences (planar versus partly twisted) led to different crystal packing structures and solid-state magnetic properties.</P>

단일계단실 고층아파트 성능설계

Fukui, Kiyoshi 한국화재보험협회 2009 防災와 保險 Vol.131 No.-

Korean and Japanese Leadership in Early Twenty-First Century East Asia : A Skeptical View

Fukui, Haruhiro 현대일본학회 1998 日本硏究論叢 Vol.10 No.-

MOLECULAR AND ATOMIC GAS IN THE LARGE MAGELLANIC CLOUD. II. THREE-DIMENSIONAL CORRELATION BETWEEN CO AND H I

Fukui, Y.,Kawamura, A.,Wong, T.,Murai, M.,Iritani, H.,Mizuno, N.,Mizuno, Y.,Onishi, T.,Hughes, A.,Ott, J.,Muller, E.,Staveley-Smith, L.,Kim, S. IOP Publishing 2009 The Astrophysical journal Vol.705 No.1

<P>We compare the CO (J = 1-0) and HI emission in the Large Magellanic Cloud in three dimensions, i.e., including a velocity axis in addition to the two spatial axes, with the aim of elucidating the physical connection between giant molecular clouds (GMCs) and their surrounding Hi gas. The CO J = 1-0 data set is from the second NANTEN CO survey and the HI data set is from the merged Australia Telescope Compact Array ( ATCA) and Parkes Telescope surveys. The major findings of our analysis are as follows: (1) GMCs are associated with an envelope of HI emission, (2) in GMCs [average CO intensity] proportional to [ average Hi intensity](1.1 +/- 0.1), and (3) the HI intensity tends to increase with the star formation activity within GMCs, from Type I to Type III. An analysis of the HI envelopes associated with GMCs shows that their average line width is 14 km s(-1) and the mean density in the envelope is 10 cm(-3). We argue that the HI envelopes are gravitationally bound by GMCs. These findings are consistent with a continual increase in the mass of GMCs via HI accretion at an accretion rate of 0.05 M-circle dot yr(-1) over a timescale of 10 Myr. The growth of GMCs is terminated via dissipative ionization and/or stellar-wind disruption in the final stage of GMC evolution.</P>

OGLE-2012-BLG-0563Lb: A SATURN-MASS PLANET AROUND AN M DWARF WITH THE MASS CONSTRAINED BY<i>SUBARU</i>AO IMAGING

Fukui, A.,Gould, A.,Sumi, T.,Bennett, D. P.,Bond, I. A.,Han, C.,Suzuki, D.,Beaulieu, J.-P.,Batista, V.,Udalski, A.,Street, R. A.,Tsapras, Y.,Hundertmark, M.,Abe, F.,Bhattacharya, A.,Freeman, M.,Itow, IOP Publishing 2015 The Astrophysical journal Vol.809 No.1

<P>We report the discovery of a microlensing exoplanet OGLE-2012-BLG-0563Lb with the planet-star mass ratio of similar to 1 x 10(-3). Intensive photometric observations of a high-magnification microlensing event allow us to detect a clear signal of the planet. Although no parallax signal is detected in the light curve, we instead succeed at detecting the flux from the host star in high-resolution JHK'-band images obtained by the Subaru/AO188 and Infrared Camera and Spectrograph instruments, allowing us to constrain the absolute physical parameters of the planetary system. With the help of spectroscopic information about the source star obtained during the high-magnification state by Bensby et al., we find that the lens system is located at 1.3(-0.8)(+0.6) kpc from us, and consists of an M dwarf (0.34(-0.20)(+0.12)M(circle dot)) orbited by a Saturn-mass planet (0.39(-0.23)(+0.14)M(Jup)) at the projected separation of 0.74(-0.42)(+0.26)AU (close model) or 4.3(-2.5)(+1.5)AU (wide model). The probability of contamination in the host star's flux, which would reduce the masses by a factor of up to three, is estimated to be 17%. This possibility can be tested by future high-resolution imaging. We also estimate the (J - K-s) and (H - K-s) colors of the host star, which are marginally consistent with a low metallicity mid-to-early M dwarf, although further observations are required for the metallicity to be conclusive. This is the fifth sub-Jupiter-mass (0.2 < m(p)/M-Jup < 1) microlensing planet around an M dwarf with the mass well constrained. The relatively rich harvest of sub-Jupiters around M dwarfs is contrasted with a possible paucity of similar to 1-2 Jupiter-mass planets around the same type of star, which can be explained by the planetary formation process in the core-accretion scheme.</P>

Analysis of the Formation of Protoplasts and Regeneration of Cells in Phycomyces blakesleeanus

Fukui, Joe,Choi, Kwan Sam,Miyazaki, Atsushi,Ootaki, Tamotsu,Oikawa, Taneaki 한국미생물 · 생명공학회 2001 Journal of microbiology and biotechnology Vol.11 No.1

It is possible to prepare protoplasts of the zygomycete fungus, Phycomyces blakesleeanus, by digesting the cell wall of spore germlings with commercially available chitinase and chitosanase. However, the cells without any cell walls immediately form large aggregates, and thus, it is difficult to isolate the individually separated protoplasts. Inherent problem with the formation of aggregates in preparing protoplasts could be solved by the use of bovine serum albumin (BSA). As a result, we were able to prepare a large number of single protoplasts quickly and easily. We took time-lapse photomicrographs of the formation of protoplasts, and found that there were certain regions of the cell wall of spore germlings that were sensitive to chitinase and chitosanase, although the cell wall of the original spores is known to be insensitive to these enzymes. There are two kinds of cell walls on a spore germling; one with a bound wheat germ agglutinin (WGA), and the other a bound concanavalin A (ConA). Furthermore, only cells with walls which had bound WGA were able to regenerate, while those with walls with bound ConA were not able to regenerate.