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51.
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Bang JK Naka H Teruya K Aimoto S Konno H Nosaka K Tatsumi T Akaji K 《The Journal of organic chemistry》2005,70(25):10596-10599
[reaction: see text] The solid-phase Horner-Emmons reaction was successfully applied for the convenient syntheses of olefin-containing protease inhibitors. The isomerization during the solid-phase Horner-Emmons reaction can be minimized simply by the use of an appropriate amount of the base. The synthesized olefin peptides, which have an olefin gamma-amino acid at the scissile site, were found to act as effective inhibitors for the HTLV-1 protease for the first time. 相似文献
53.
Tetraalkylphosphonium-based amino-acid ionic liquids show lower viscosities and higher decomposition temperatures (>300 degrees C) than previously reported ammonium-based amino-acid ionic liquids. 相似文献
54.
Shimada T Kondoh H Iwasaki M Nakai I Nagasaka M Amemiya K Orita H Ohta T 《The journal of physical chemistry. B》2006,110(41):20507-20512
The adsorption structure of NO on the reconstructed Pt(110)-(1 x 2) surface was studied with X-ray photoelectron spectroscopy (XPS), X-ray photoelectron diffraction (XPD), low-energy scanned-angle photoelectron diffraction (LESA-PD), and near-edge X-ray absorption fine structure (NEXAFS) spectroscopy. The experiments were performed at 180 K, where no surface lifting from (1 x 2) to (1 x 1) takes place after NO adsorption. XPS indicates that the (1 x 2) unit cell of the Pt(110) surface contains 1.5 NO molecules at the saturated coverage. XPD and LESA-PD analyses allow us to propose a structural model for the NO adlayer, where two-thirds of the NO molecules in the (1 x 2) unit cell are adsorbed on the atop site of the close-packed Pt rows (ridges) along the [10] direction with an inclined geometry and one-third of the NO molecules adsorb on the bridge site between the Pt ridges with an upright configuration. This model is supported by the N K-edge NEXAFS experiments and is consistent with the recently reported model based on the density functional theory (Orita, H.; Nakamura, I.; Fujitani, T. J. Phys. Chem. B 2005, 109, 10312). 相似文献
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56.
Background
The purpose of this study was to examine task-related changes in prefrontal cortex (PFC) activity during a dual-task in both healthy young and older adults and compare patterns of activation between the age groups. We also sought to determine whether brain activation during a dual-task relates to executive/attentional function and how measured factors associated with both of these functions vary between older and younger adults.Results
Thirty-five healthy volunteers (20 young and 15 elderly) participated in this study. Near-infrared spectroscopy (NIRS) was employed to measure PFC activation during a single-task (performing calculations or stepping) and dual-task (performing both single-tasks at once). Cognitive function was assessed in the older patients with the Trail-making test part B (TMT-B). Major outcomes were task performance, brain activation during task (oxygenated haemoglobin: Oxy-Hb) measured by NIRS, and TMT-B score. Mixed ANOVAs were used to compare task factors and age groups in task performance. Mixed ANOVAs also compared task factors, age group and time factors in task-induced changes in measured Oxy-Hb. Among the older participants, correlations between the TMT-B score and Oxy-Hb values measured in each single-task and in the dual-task were examined using a Pearson correlation coefficient. Oxy-Hb values were significantly increased in both the calculation task and the dual-task within patients in both age groups. However, the Oxy-Hb values associated with there were higher in the older group during the post-task period for the dual-task. Also, there were significant negative correlations between both task-performance accuracy and Oxy-Hb values during the dual-task and participant TMT-B scores.Conclusions
Older adults demonstrated age-specific PFC activation in response to dual-task challenge. There was also a significant negative correlation between PFC activation during dual-task and executive/attentional function. These findings suggest that the high cognitive load induced by dual-task activity generates increased PFC activity in older adults. However, this relationship appeared to be strongest in participants with better baseline attention and executive functions. 相似文献57.
Hiroki Kanda Brian Beckford Takeji Fujibayashi Takao Fujii Yu Fujii Kenta Futatsukawa Toshiyuki Gogami Yun-Cheng Han Osamu Hashimoto Kentaro Hirose Ryotaro Honda Kenji Hosomi Alan Iguchi Takatsugu Ishikawa Yusuke Kaneko Masashi Kaneta Yuma Kasai Daisuke Kawama Taito Kawasaki Chigusa Kimura Shogo Kiyokawa Takeshi Koike Kazushige Maeda Tomofumi Maruta Nayuta Maruyama Masao Matsubara Koji Miwa Yohei Miyagi Sho Nagao Satoshi N. Nakamura Akira Okuyama Kotaku Suzuki Tadaaki Tamae Hirokazu Tamura Nobuhiro Terada Kyo Tsukada Tie-Shang Wang Fumiya Yamamoto Takeshi O. Yamamoto Hirohito Yamazaki 《Few-Body Systems》2013,54(7-10):1175-1178
Photoproduction of the neutral kaon on the deuteron has been investigated at the Research Center for Electron Photon Science, Tohoku University. We constructed the Neutral Kaon Spectrometer-2 for the detection of charged particles from the decay of the neutral kaon and the hyperon. We obtained a momentum distribution of K 0 with the inclusive measurement. It was consistent with the previous measurement. The total cross section of γ + d → K 0 + Λ + p was estimated from the measured integral cross section of γ + d → Λ + X. The total cross section with respect to the photon energy was compared with the theoretical calculations. It favored the Saclay-Lyon A model calculation with the ratio of the neutral to charged coupling constants of the axial-vector meson, K 1, as ~ ?1.5. The energy dependence and the magnitude of the total cross section were similar to the total cross section of γ + p → K + Λ. 相似文献
58.
Halichonic acid,a new rearranged bisabolene-type sesquiterpene from a marine sponge Halichondria sp.
Kenta Raiju Yuki Hitora Hikaru Kato Yuji Ise Esther D. Angkouw Remy E.P. Mangindaan Sachiko Tsukamoto 《Tetrahedron letters》2019,60(15):1079-1081
A new compound, halichonic acid (1), was isolated from a marine sponge Halichondria sp., together with (6R,7S)-7-amino-7,8-dihydro-α-bisabolene (2). The structure of 1 was elucidated by spectroscopic analysis and ECD spectrum calculation to be a rearranged bisabolene-type sesquiterpene having a 3-azabicyclo[3.3.1]nonene moiety. Compound 2 was cytotoxic against HeLa cells with an IC50 value of 50?μM, whereas 1 did not show cytotoxicity even at 50?μM. It is possible that 1 is biosynthesized from farnesyl pyrophosphate and glycine, with rearrangement. 相似文献
59.
Yuki Matsumoto Takafumi Yamamoto Kousuke Nakano Hiroshi Takatsu Taito Murakami Kenta Hongo Ryo Maezono Hiraku Ogino Dongjoon Song Craig M. Brown Cdric Tassel Hiroshi Kageyama 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(3):766-769
Square‐planar coordinate Ni2+ ions in oxides are exclusively limited to a low‐spin state (S=0) owing to extensive crystal field splitting. Layered oxychalcogenides A2NiIIO2Ag2Se2 (A=Sr, Ba) with the S=1 NiO2 square lattice are now reported. The structural analysis revealed that the Ni2+ ion is under‐bonded by a significant tensile strain from neighboring Ag2Se2 layers, leading to the reduction in crystal field splitting. Ba2NiO2Ag2Se2 exhibits a G‐type spin order at 130 K, indicating fairly strong in‐plane interactions. The high‐pressure synthesis employed here possibly assists the expansion of NiO2 square lattice by taking the advantage of the difference in compressibility in oxide and selenide layers. 相似文献
60.
Kenta Nagamine Keita Hirose Tsuyoshi Honma Takayuki Komatsu 《Solid State Ionics》2008,179(13-14):508-515
The glasses with the composition of 37.5Li2O–(25 − x)Fe2O3–xNb2O5–37.5P2O5 (mol%) (x = 5,10,15) are prepared, and it is found that the addition of Nb2O5 is effective for the glass formation in the lithium iron phosphate system. The glass–ceramics consisting of Nasicon-type Li3Fe2(PO4)3 crystals with an orthorhombic structure are developed through conventional crystallization in an electric furnace, showing electrical conductivities of 3 × 10− 6 Scm− 1 at room temperature and the activation energies of 0.48 eV (x = 5) and 0.51 eV (x = 10) for Li+ ion conduction in the temperature range of 30–200 °C. A continuous wave Nd:YAG laser (wavelength: 1064 nm) with powers of 0.14–0.30 W and a scanning speed of 10 μm/s is irradiated onto the surface of the glasses, and the formation of Li3Fe2(PO4)3 crystals is confirmed from XRD analyses and micro-Raman scattering spectra. The crystallization of the precursor glasses is considered as new route for the fabrication of Li3Fe2(PO4)3 crystals being candidates for use as electrolyte materials in lithium ion secondary batteries. 相似文献