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101.
102.
Hiromi NAKANISHI Atsushi MORI Kouki TAKEDA Houdo TANAKA Natsuko KOBAYASHI Keitaro TANOI Takashi YAMAKAWA Satoshi MORI 《Proceedings of the Japan Academy. Series B, Physical and biological sciences》2015,91(4):160-174
Six months after the explosion of TEPCO’s Fukushima Dai-ichi nuclear power plant, radioactive
silver (110mAg), was detected in concentrations of 3754 Bq/kg in Nephila
clavata (the orb-web spider; Joro-gumo in Japanese) collected at
Nimaibashi, Iitate village in Fukushima Prefecture, whereas 110mAg in the soil was
43.1 Bq/kg. A survey of 35 faunal species in the terrestrial environment during the 3.5 years
after the accident showed that most of Anthropoda had two orders higher 110mAg in
their tissues than soils, although silver is not an essential element for their life. However,
tracing of the activity of 110mAg detected in spider Atypus karschi
collected regularly at a fixed location showed that it declined much faster than the physical
half-life. These results suggest that 110mAg was at once biologically concentrated
by faunal species, especially Arthropoda, through food chain. The factors affecting the
subsequent rapid decline of 110mAg concentration in faunal species are
discussed. 相似文献
103.
Prof. Yutaka Maeda Yuhei Hasuike Prof. Kei Ohkubo Atsushi Tashiro Shinya Kaneko Masayuki Kikuta Dr. Michio Yamada Prof. Tadashi Hasegawa Prof. Takeshi Akasaka Dr. Jing Zhou Prof. Jing Lu Prof. Shigeru Nagase Prof. Shunichi Fukuzumi 《Chemphyschem》2014,15(9):1821-1826
This report describes the photochemical behavior of single‐walled carbon nanotubes (SWNTs) in the presence of propylamine. The SWNTs are characterized by absorption and Raman spectroscopy. The spectral changes due to photoirradiation indicate that reactions occur predominantly with the metallic SWNTs and small‐diameter SWNTs. The detection of amine radicalcation species by ESR spectroscopy reveals photoinduced electron transfer from the amine to the excited SWNTs. After exposure of the photoirradiated SWNTs to air, the characteristic spectra were recovered, except for that of the small‐diameter SWNTs. The results suggest that, after photoreduction of the SWNTs, subsequent selective sidewall functionalization of the small‐diameter SWNTs occurs. 相似文献
104.
Hong Tho Le Dr. Chen-Gang Wang Prof. Dr. Atsushi Goto 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(24):9446-9450
Liquid vinyl monomers were converted into solid crystals via halogen bonding. They underwent solid-phase radical polymerizations through heating at 40 °C or ultraviolet photo-irradiation (365 nm). The X-ray crystallography analysis showed the high degree of monomer alignment in the crystals. The polymerizations of the solid monomer crystals yielded polymers with high molecular weights and relatively low dispersities because of the high degree of the monomer alignment in the crystal. As a unique application of this system, the crystalized monomers were assembled to pre-determined structures, followed by solid-phase polymerization, to obtain a two-layer polymer sheet and a three-dimensional house-shaped polymer material. The two-layer sheet contained a unique asymmetric pore structure and exhibited a solvent-responsive shape memory property and may find applications to asymmetric membranes and polymer actuators. 相似文献
105.
Daisuke Saito Dr. Tomohiro Ogawa Dr. Masaki Yoshida Junichi Takayama Dr. Satoshi Hiura Prof. Dr. Akihiro Murayama Dr. Atsushi Kobayashi Prof. Dr. Masako Kato 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(42):18882-18889
A series of assembled PtII complexes comprising N-heterocyclic carbene and cyanide ligands was constructed using different substituent groups, [Pt(CN)2(R-impy)] (R-impyH+=1-alkyl-3-(2-pyridyl)-1H-imidazolium, R=Me ( Pt-Me ), Et ( Pt-Et ), iPr ( Pt- i Pr ), and tBu ( Pt- t Bu )). All the complexes exhibited highly efficient photoluminescence with an emission quantum yield of 0.51–0.81 in the solid state at room temperature, originating from the triplet metal-metal-to-ligand charge transfer (3MMLCT) state. Their emission colors cover the entire visible region from red for Pt-Me to blue for Pt- t Bu . Importantly, Pt- t Bu is the first example that exhibits blue 3MMLCT emission. The 3MMLCT emission was proved and characterized based on the temperature dependences of the crystal structures and emission properties. The wide-range color tuning of luminescence using the 3MMLCT emission presents a new strategy of superfine control of the emission color. 相似文献
106.
Ribeiro Geyse Adriana Corrêa da Rocha Cláudia Quintino Veloso William Barros Dantas Luiza Maria Ferreira Richter Eduardo Mathias da Silva Iranaldo Santos Tanaka Auro Atsushi 《Journal of Solid State Electrochemistry》2020,24(8):1759-1768
Journal of Solid State Electrochemistry - Rapid methods using batch injection analysis (BIA) with amperometric detection were developed for the determination of quercetin extracted from the... 相似文献
107.
Shuntaro Matsuta Noriaki Shima Hidenao Kakehashi Akari Ishikawa Ryutaro Asai Atsushi Nitta Misato Wada Shihoko Nakano Hiroe Kamata Yoshio Nishiyama Hirohisa Nagatani Hisanori Imura Munehiro Katagi 《Journal of mass spectrometry : JMS》2020,55(9)
Various cathinone‐derived designer drugs (CATs) have recently appeared on the drug market. This study examined the mechanism for the generation of dehydrated ions for CATs during electrospray ionization collision‐induced dissociation (ESI‐CID). The generation mechanism of dehydrated ions is dependent on the amine classification in the cathinone skeleton, which is used in the identification of CATs. The two hydrogen atoms eliminated during the dehydration of cathinone (primary amine) and methcathinone (secondary amine) were determined, and the reaction mechanism was elucidated through the deuterium labeling experiments. The hydrogen atom bonded to the amine nitrogen was eliminated with the proton added during ESI, in both of the tested compounds. This provided evidence that CATs with tertiary amine structures (such as dimethylcathinone and α‐pyrrolidinophenones [α‐PPs]) do not undergo dehydration. However, it was shown that the two major tertiary amine metabolites (1‐OH and 2″‐oxo) of CATs generate dehydrated ions in ESI‐CID. The dehydration mechanisms of the metabolites of α‐pyrrolidinobutiophenone (α‐PBP) belongs to α‐PPs were also investigated. Stable‐isotope labeling showed the dehydration of the 1‐OH metabolite following a simple mechanism where the hydroxy group was eliminated together with the proton added during ESI. In contrast, the dehydration mechanism of the 2″‐oxo metabolite involved hydrogen atoms in three or more locations along with the carbonyl group oxygen, indicating that dehydration occurred via multiple mechanisms likely including the rearrangement reaction of hydrogen atoms. These findings presented herein indicate that the dehydrated ions in ESI‐CID can be used for the structural identification of CATs. 相似文献
108.
Yulu Jiang Taro Ozaki Mei Harada Tadachika Miyasaka Hajime Sato Kazunori Miyamoto Junichiro Kanazawa Chengwei Liu Jun‐ichi Maruyama Masaatsu Adachi Atsuo Nakazaki Toshio Nishikawa Masanobu Uchiyama Atsushi Minami Hideaki Oikawa 《Angewandte Chemie (International ed. in English)》2020,59(41):17996-18002
Lolitrems are tremorgenic indole diterpenes that exhibit a unique 5/6 bicyclic system of the indole moiety. Although genetic analysis has indicated that the prenyltransferase LtmE and the cytochrome P450 LtmJ are involved in the construction of this unique structure, the detailed mechanism remains to be elucidated. Herein, we report the reconstitution of the biosynthetic pathway for lolitrems employing a recently established genome‐editing technique for the expression host Aspergillus oryzae. Heterologous expression and bioconversion of the various intermediates revealed that LtmJ catalyzes multistep oxidation to furnish the lolitrem core. We also isolated the key reaction intermediate with an epoxyalcohol moiety. This observation allowed us to establish the mechanism of radical‐induced cyclization, which was firmly supported by density functional theory calculations and a model experiment with a synthetic analogue. 相似文献
109.
Tatsuro Ouchi Hidetake Miyazaki Hidetoshi Arimura Fumitaka Tasaka Atsushi Hamada Yuichi Ohya 《Journal of polymer science. Part A, Polymer chemistry》2002,40(10):1426-1432
Amphiphilic AB‐type diblock copolymers composed of hydrophobic poly(L ‐lactide) (PLA) segments and hydrophilic poly(glycolic acid lysine) [poly(Glc‐Lys)] segments with amino side‐chain groups self‐associated to form PLA‐based polymeric micelles with amino surfaces in an aqueous solution. The average diameter of the loose core–shell polymeric micelles for poly(Glc‐Lys) [number‐average molecular weight (Mn) = 1240]‐b‐PLA (Mn = 7000) obtained by a dimethyl sulfoxide/water dialysis method was estimated to be about 50 nm in water by dynamic light scattering measurements. The size and shape of the obtained polymeric micelles were further observed with transmission electron microscopy and atomic force microscopy. To investigate the possibility of applying the obtained PLA‐based polymeric micelles as bioabsorbable vehicles for hydrophobic drugs, we tested the entrapment of drugs in poly(Glc‐Lys) (Mn = 1240)‐b‐PLA (Mn = 7000) micelles and their release with doxorubicin as a hydrophobic drug. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 1426–1432, 2002 相似文献
110.