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971.
Direct Synthesis of Chromium Perovskite Oxyhydride with a High Magnetic‐Transition Temperature
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Dr. Cédric Tassel Yoshihiro Goto Yoshinori Kuno Dr. James Hester Prof. Mark Green Dr. Yoji Kobayashi Prof. Hiroshi Kageyama 《Angewandte Chemie (International ed. in English)》2014,53(39):10377-10380
We report a novel oxyhydride SrCrO2H directly synthesized by a high‐pressure high‐temperature method. Powder neutron and synchrotron X‐ray diffraction revealed that this compound adopts the ideal cubic perovskite structure with O2?/H? disorder. Surprisingly, despite the non‐bonding nature between Cr 3d t2g orbitals and the H 1s orbital, it exhibits G‐type spin ordering at TN≈380 K, which is higher than that of RCrO3 (R=rare earth) and any chromium oxides. The enhanced TN in SrCrO2H with four Cr‐O‐Cr bonds in comparison with RCr3+O3 with six Cr‐O‐Cr bonds is reasonably explained by the tolerance factor. The present result offers an effective strategy to tune octahedral tilting in perovskites and to improve physical and chemical properties through mixed anion chemistry. 相似文献
972.
Prapassorn Rugthaworn Yoshinori Murata Masashi Machida Waraporn Apiwatanapiwat Akiko Hirooka Warunee Thanapase Hatairat Dangjarean Satoru Ushiwaka Kozo Morimitsu Akihiko Kosugi Takamitsu Arai Pilanee Vaithanomsat 《Applied biochemistry and biotechnology》2014,173(5):1197-1208
In this study, we report the inhibition of Kluyveromyces marxianus TISTR5925 growth and ethanol fermentation in the presence of furan derivatives and weak acids (acetic acid and lactic acid) at high temperatures. Cassava pulp, obtained as the waste from starch processing, was collected from 14 starch factories located in several provinces of Thailand. At a high temperature (42 °C), the cassava pulp hydrolysate from some starch factories strongly inhibited growth and ethanol production of both K. marxianus (strain TISTR5925) and Saccharomyces cerevisiae (strain K3). HPLC detected high levels of lactic acid and acetic acid in the hydrolysates, suggesting that these weak acids impaired the growth of K. marxianus at high temperature. We isolated Trp-requiring mutants that had reduced tolerance to acetic acid compared to the wild-type. This sensitivity to acetic acid was suppressed by supplementation of the medium with tryptophan. 相似文献
973.
Akihiro Fujii Toshihiro Koura Takashi Yoshimoto Toshiyuki Kawabata Yoshinori Nakamura Keita Hamamichi Hitoshi Kakimoto Yoshimune Yamada Mitsuo Yoshioka Masayoshi Yamamoto Kazuichi Hayakawa 《Journal of Radioanalytical and Nuclear Chemistry》2014,300(2):707-717
A variety of wild mushrooms were collected in a forest on the Noto Peninsula, Japan, to determine the concentration of 137Cs and 40K. The wild mushroom species belong to the orders Agaricales and Aphyllophorales. The concentration of 137Cs varied widely (1.4–4,100 Bq/kg dry weight) in mushrooms growing in soil. On the contrary, 137Cs concentration levels were relatively low (1.9–20 Bq/kg-dry weight) in mushrooms growing on wood. The concentration of 40K varied widely (12–2,400 Bq/kg-dry weight) in contrast with several previous reports that suggest relatively constant 40K levels in mushrooms. Unusually low concentrations of 40K were observed in a few mushroom species that had very hard fruiting bodies with peculiar shapes. The mean and median of 137Cs concentration in the present study were similar to those previously reported for Japanese mushrooms. Among the Agaricales mushrooms, Entolomataceae and Tricholomataceae families growing in soil had the highest concentration of 137Cs. Among the Aphyllophorales mushrooms, Gomphaceae and Ramariaceae families growing in soil also had the highest 137Cs concentrations. The concentrations of 137Cs and stable Cs in mushroom samples were positively correlated. The concentration ratio of 137Cs/Cs differed between Agaricales and Aphyllophorales mushrooms. The average 137Cs/Cs ratio in mushrooms growing in soil was similar to that calculated for the top soil (<5 cm deep) alone because the mycelia of the mushrooms were mainly distributed near the surface of the soil. 相似文献
974.
Yoshinori Saito Yoko Sasaki Teppei Komiyama Ayumi Ohsaki Yasuko Okamoto Xun Gong Chiaki Kuroda Motoo Tori 《Tetrahedron》2014
Five new 12-oxygenated eremophilane sesquiterpenoids bearing a B-ring enone system were isolated from Ligularia lingiana S.W. Liu (Asteraceae) collected in China. Compound 5 was a Diels–Alder adduct of 3α-angeloyloxy-7βH-8-oxoeremophila-9,11(13)-dien-12-al and the monoterpene, ocimene. Compound 1 showed cytotoxic activities against HeLa, HL60, Jurkat, and NIH-3T3 cells at IC50 0.0407, 0.440, 0.313, and 3.48 μM, respectively. 相似文献
975.
Self‐Healing,Expansion–Contraction,and Shape‐Memory Properties of a Preorganized Supramolecular Hydrogel through Host–Guest Interactions
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Kohei Miyamae Dr. Masaki Nakahata Dr. Yoshinori Takashima Prof. Dr. Akira Harada 《Angewandte Chemie (International ed. in English)》2015,54(31):8984-8987
Supramolecular materials cross‐linked between polymer chains by noncovalent bonds have the potential to provide dynamic functions that are not produced by covalently cross‐linked polymeric materials. We focused on the formation of supramolecular polymeric materials through host–guest interactions: a powerful method for the creation of nonconventional materials. We employed two different kinds of host–guest inclusion complexes of β‐cyclodextrin (βCD) with adamantane (Ad) and ferrocene (Fc) to bind polymers together to form a supramolecular hydrogel (βCD‐Ad‐Fc gel). The βCD‐Ad‐Fc gel showed self‐healing ability when damaged and responded to redox stimuli by expansion or contraction. Moreover, the βCD‐Ad‐Fc gel showed a redox‐responsive shape‐morphing effect. We thus succeeded in deriving three functions from the introduction of two kinds of functional units into a supramolecular material. 相似文献
976.
Shuji MAEDA Yoshinori AKAISHI Toshimitsu YAMAZAKI 《Proceedings of the Japan Academy. Series B, Physical and biological sciences》2013,89(9):418-437
Non-relativistic Faddeev and Faddeev-Yakubovsky calculations were made for K−pp, K−ppn, K−K−p and K−K−pp kaonic nuclear clusters, where the quasi bound states were treated as bound states by employing real separable potential models for the K−-K− and the K−-nucleon interactions as well as for the nucleon-nucleon interaction. The binding energies and spatial shrinkages of these states, obtained for various values of the interaction, were found to increase rapidly with the interaction strength. Their behaviors are shown in a reference diagram, where possible changes by varying the interaction in the dense nuclear medium are given. Using the Λ(1405) ansatz with a PDG mass of 1405 MeV/c2 for K−p, the following ground-state binding energies together with the wave functions were obtained: 51.5 MeV (K−pp), 69 MeV (K−ppn), 30.4 MeV (K−K−p) and 93 MeV (K−K−pp), which are in good agreement with previous results of variational calculation based on the Akaishi-Yamazaki coupled-channel potential. The K−K−pp state has a significantly increased density where the two nucleons are located very close to each other, in spite of the inner NN repulsion. Relativistic corrections on the calculated non-relativistic results indicate substantial lowering of the bound-state masses, especially of K−K−pp, toward the kaon condensation regime. The fact that the recently observed binding energy of K−pp is much larger (by a factor of 2) than the originally predicted one may infer an enhancement of the interaction in dense nuclei by about 25% possibly due to chiral symmetry restoration. In this respect some qualitative accounts are given based on “clearing QCD vacuum” model of Brown, Kubodera and Rho. 相似文献
977.
978.
979.
980.
Yoshinori Suzuma Shoko Hayashi Tetsuya Yamamoto Yohei Oe Tetsuo Ohta Yoshihiko Ito 《Tetrahedron: Asymmetry》2009,20(23):2751-2758
A combination of palladium with ferrocene-based phosphine ligand with a carbon–bromine bond was found to be a good catalyst for the 1,4-addition of arylboronic acids to α,β-unsaturated ketones and the 1,2-addition to aldehydes. Using Pd(dba)2 and (S,Rp)-[1-(2-bromoferrocenyl)ethyl]diphenylphosphine (S,Rp)-1, 3-phenylcyclohexanone was obtained from the reaction of 2-cyclohexen-1-one with phenylboronic acid in the presence of K2CO3 in toluene at room temperature after 3 h in 92% yield with 76% ee. In the 1,2-addition of 4-methylphenylboronic acid to benzaldehyde, 96% of (4-methylphenyl)phenylmethanol was afforded after 24 h, while the enantiomeric excess was only 6%. 相似文献