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991.
Nakanishi J Horiuchi Y Yamada T Ishii O Yamazaki M Yoshida M Fujimoto Y 《Optics letters》2011,36(10):1836-1838
We demonstrated a high-power and highly efficient Pr-doped waterproof fluoride glass fiber laser at 522.2 nm excited by two-polarization-combined GaN laser diodes and achieved a subwatt output power of 598 mW and slope efficiency of 43.0%. This system will enable us to make a vivid laser display, a photocoagulation laser for eye surgery, a color confocal scanning laser microscope, and an effective laser for material processing. Direct visible ultrashort pulse generation is also expected. 相似文献
992.
Suzuki K Matsuo T Hashizume D Tamao K 《Journal of the American Chemical Society》2011,133(49):19710-19713
A room-temperature dynamic equilibrium between dibromodisilenes and bromosilylenes has been demonstrated by taking advantage of the steric protection using the fused-ring bulky 1,1,3,3,5,5,7,7-octa-R-s-hydrindacen-4-yl (Rind) groups. Although the bromosilylenes cannot be directly observed by spectroscopic methods, the thermal homolytic cleavage of the Si═Si double bond has been confirmed by a pseudo-first-order kinetics for the trapping with bis(trimethylsilyl)acetylene and a crossover reaction using two kinds of Rind-substituted dibromodisilenes. The addition of 4-pyrrolidinopyridine (PPy) to the dibromodisilene leads to an equilibrium mixture between the dibromodisilene and a PPy adduct of bromosilylene, the latter being isolated and characterized. The substitution of the bromine atom in the dibromodisilene by the Grignard reagent is significantly accelerated by the addition of PPy. 相似文献
993.
Shoji Y Matsuo T Hashizume D Gutmann MJ Fueno H Tanaka K Tamao K 《Journal of the American Chemical Society》2011,133(29):11058-11061
Diborane(6) as a H-bridged dimer of monoborane can be converted cleanly by two-electron reduction into diborane(6) dianion, which is isoelectronic with ethane, through B-B σ-bond formation when each boron atom has a bulky ligand on it. The existence of the B-B σ bond is supported by the X-ray molecular structure [B-B bond length of 1.924(3) ?], NMR studies, magnetic susceptibility measurements, and DFT calculations. Stepwise hydride abstraction reactions of the diborane(6) dianion produce the corresponding H-bridged diborane(5) anion and doubly H-bridged diborane(4) without B-B bond scission. 相似文献
994.
Jang JH Asami Y Jang JP Kim SO Moon DO Shin KS Hashizume D Muroi M Saito T Oh H Kim BY Osada H Ahn JS 《Journal of the American Chemical Society》2011,133(18):6865-6867
An acinar morphogenesis inhibitor named fusarisetin A (1) that possesses both an unprecedented carbon skeleton and a new pentacyclic ring system has been identified from an in-house fractionated fungal library using a three-dimensional matrigel-induced acinar morphogenesis assay system. The structure of 1 was determined in detail by NMR and circular dichroism spectroscopy, X-ray analysis, and chemical reaction experiments. 相似文献
995.
Choi W Harada D Oyaizu K Nishide H 《Journal of the American Chemical Society》2011,133(49):19839-19843
A layer of poly(2-vinylanthraquinone) on current collectors underwent reversible electrode reaction at -0.82 V vs Ag/AgCl in an aqueous electrolyte. A repeatable charging/discharging cycles with a redox capacity comparable to the formula weight-based theoretical density at the negative potential suggested that all of the anthraquinone pendants in the layer was redox-active, that electroneutralization by an electrolyte cation was accomplished throughout the polymer layer, and that the layer stayed on the current collector without exfoliation or dissolution into the electrolyte during the electrolysis. The charging/discharging behavior of the polymer layer in the aqueous electrolyte revealed the capability of undergoing electrochemistry even in the nonsolvent of the pendant group, which offered insight into the nature of the anthraquinone pendants populated on the aliphatic chain. Charging/discharging capability of air batteries was accomplished by using the polymer layer as an organic anode-active material. A test cell fabricated using the conventional MnO(2)/C cathode catalyst exhibited a discharging voltage at 0.63 V corresponding to their potential gap and a charging/discharging cycle of more than 500 cycles without loss of the capacity. 相似文献
996.
Noriyoshi Ishii 《Few-Body Systems》2011,49(1-4):269-281
Lattice QCD study of nuclear potentials is reported. A lattice QCD method to calculate realistic nuclear potentials is developed. In this method, Bethe–Salpeter wave functions generated on the lattice are used to reconstruct nuclear potentials by using Schrödinger equation. It is one of the possible extensions of Lüscher’s finite volume method for scattering phase shifts. Hence the resulting potential can reproduce the scattering data. The method was first applied to the central potential in NN system. It is now applied to various objects, such as tensor potential, hyperon potentials both in quenched QCD and 2 + 1 flavor QCD generated by PACS-CS Collaboration. 相似文献
997.
Shean-Yeaw Ng Chin-Soon Phan Takahiro Ishii Takashi Kamada Toshiyuki Hamada Charles Santhanaraju Vairappan 《Molecules (Basel, Switzerland)》2020,25(22)
Members of the marine soft coral genus Xenia are rich in a diversity of diterpenes. A total of 199 terpenes consisting of 14 sesquiterpenes, 180 diterpenes, and 5 steroids have been reported to date. Xenicane diterpenes were reported to be the most common chemical skeleton biosynthesized by members of this genus. Most of the literature reported the chemical diversity of Xenia collected from the coral reefs in the South China Sea and the coastal waters of Taiwan. Although there was a brief review on the terpenoids of Xenia in 2015, the present review is a comprehensive overview of the structural diversity of secondary metabolites isolated from soft coral genus Xenia and their potent biological activity as reported between 1977 to 2019. 相似文献
998.
Yue Wang Koki Ogasahara Daisuke Tomihama Radomir Mysliborski Masatoshi Ishida Yongseok Hong Yusuke Notsuka Yoshihisa Yamaoka Tomotaka Murayama Atsuya Muranaka Masanobu Uchiyama Shigeki Mori Yuhsuke Yasutake Susumu Fukatsu Dongho Kim Hiroyuki Furuta 《Angewandte Chemie (International ed. in English)》2020,59(37):16161-16166
The synthesis of organometallic complexes of modified 26π‐conjugated hexaphyrins with absorption and emission capabilities in the third near‐infrared region (NIR‐III) is described. Symmetry alteration of the frontier molecular orbitals (MOs) of bis‐PdII and bis‐PtII complexes of hexaphyrin via N‐confusion modification led to substantial metal dπ–pπ interactions. This MO mixing, in turn, resulted in a significantly narrower HOMO–LUMO energy gap. A remarkable long‐wavelength shift of the lowest S0→S1 absorption beyond 1700 nm was achieved with the bis‐PtII complex, t ‐Pt2‐3 . The emergence of photoacoustic (PA) signals maximized at 1700 nm makes t ‐Pt2‐3 potentially useful as a NIR‐III PA contrast agent. The rigid bis‐PdII complexes, t ‐Pd2‐3 and c ‐Pd2‐3 , are rare examples of NIR emitters beyond 1500 nm. The current study provides new insight into the design of stable, expanded porphyrinic dyes possessing NIR‐III‐emissive and photoacoustic‐response capabilities. 相似文献
999.
Shintaro Takahashi Kazuki Nakaya María Frutos Antoine Baceiredo Nathalie Saffon‐Merceron Stphane Massou Norio Nakata Daisuke Hashizume Vicen Branchadell Tsuyoshi Kato 《Angewandte Chemie (International ed. in English)》2020,59(37):15937-15941
A novel N‐hetero‐RhI‐metallacyclic silanone 2 has been synthesized. The silanone 2 , showing an extremely large dimerization energy (ΔG=+86.2 kcal mol?1), displays considerable stability and persists in solution up to 60 °C. Above 120 °C, an intramolecular Csp3?H insertion occurs slowly over a period of two weeks leading to the bicyclic silanol 5 . The exceptional stability of 2 , related to the unusual electronic and steric effects of RhI‐substituent, should allow for a more profound study and understanding of these new species. Furthermore, the metallacyclic silanone 2 presents two reactive centers (Si=O and Rh), which can be involved depending upon the nature of reagents. Of particular interest, the reaction with H2 starts with the hydrogenation of RhI center leading to the corresponding RhIII‐dihydride complex 7 and it undergoes a cis/trans‐isomerization via a particular mechanism, demonstrating that addition‐elimination processes can also happen for silanones just like for their carbon analogues! 相似文献
1000.
Maki Komiya Miki Kato Daisuke Tadaki Teng Ma Hideaki Yamamoto Ryugo Tero Yuzuru Tozawa Michio Niwano Ayumi Hirano‐Iwata 《Chemical record (New York, N.Y.)》2020,20(7):730-742
An artificial cell membrane that is composed of bilayer lipid membranes (BLMs) with transmembrane proteins incorporated within them represents a well‐defined system for the analysis of membrane proteins, especially ion channel proteins that are major targets for drug design. Because the BLM system has a high compatibility with recently developed cell‐free expression systems, it has attracted attention as a next‐generation drug screening system. However, three issues associated with BLM systems, i. e., their instability, the need for non‐volatile organic solvents and a low efficiency of ion channel incorporation, have limited their use as a drug screening platform. In this personal account, we discuss our recent approaches to address these issues based on microfabrication. We also discuss the potential for using the BLM system combined with cell‐free expression systems as a drug screening system for future personalized medicine. 相似文献