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221.
Two novel estimation parameters are proposed for bio-speckle blood flow imaging in skin tissue with reducing effects of a
speckle contrast and random noises. Estimation parameters are introduced to reduce the effect of the speckle contrast on the
sensitivity of the blood flow sensing and to eliminate an offset component due to random noises superimposed on the speckle
images. Experiments were conducted for a sample model using ground-glass plates, human vein and finger to confirm the feasibility
of the proposed parameters. 相似文献
222.
Kyosuke Matsumoto Shunsuke Kusaba Yuya Tanaka Yoshihisa Sei Munetaka Akita Kazushi Aritani Masa‐aki Haga Michito Yoshizawa 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(25):8551-8555
Synthesis of molecular containers capable of incorporating multiple fullerenes remains challenging. Reported here is that room‐temperature mixing of metal ions with W‐shaped bispyridine ligands featuring polyaromatic panels results in the quantitative formation of a peanut‐shaped M2L4 capsule. The capsule reversibly converts into two molecules of an ML2 double tube in response to changes in the solvent. Notably, the capsule allows the incorporation of two fullerene molecules into the connected two spherical cavities at room temperature. The close proximity yet non‐contact of the encapsulated C60 molecules, with a separation of 6.4 Å, was revealed by X‐ray crystallographic analysis. The resultant, unusual fullerene dimer undergoes sequential reduction within the capsule to generate (C60.?)2, C60.??C602?, and (C602?)2 species. Furthermore, temperature‐controlled stepwise incorporation of two C60 molecules into the capsule is demonstrated. 相似文献
223.
Moghaddam S Yang C Rekharsky M Ko YH Kim K Inoue Y Gilson MK 《Journal of the American Chemical Society》2011,133(10):3570-3581
A dicationic ferrocene derivative has previously been shown to bind cucurbit[7]uril (CB[7]) in water with ultrahigh affinity (ΔG(o) = -21 kcal/mol). Here, we describe new compounds that bind aqueous CB[7] equally well, validating our prior suggestion that they, too, would be ultrahigh affinity CB[7] guests. The present guests, which are based upon either a bicyclo[2.2.2]octane or adamantane core, have no metal atoms, so these results also confirm that the remarkably high affinities of the ferrocene-based guest need not be attributed to metal-specific interactions. Because we used the M2 method to compute the affinities of several of the new host-guest systems prior to synthesizing them, the present results also provide for the first blinded evaluation of this computational method. The blinded calculations agree reasonably well with experiment and successfully reproduce the observation that the new adamantane-based guests achieve extremely high affinities, despite the fact that they position a cationic substituent at only one electronegative portal of the CB[7] host. However, there are also significant deviations from experiment, and these lead to the correction of a procedural error and an instructive evaluation of the sensitivity of the calculations to physically reasonable variations in molecular energy parameters. The new experimental and computational results presented here bear on the physical mechanisms of molecular recognition, the accuracy of the M2 method, and the usefulness of host-guest systems as test-beds for computational methods. 相似文献
224.
Michael Oelgemöller Rudolf Frank Peter Lemmen Dieter Lenoir Johann Lex Yoshihisa Inoue 《Tetrahedron》2012,68(21):4048-4056
Six cyclic stilbene derivatives with hindered free rotation around the C(vinyl)–C(phenyl) single bond were synthesized by McMurry coupling. The torsion angles around the double and the single bond, and the CC bond length were obtained for many of the compounds from their solid-state structures. The photochemical isomerization was subsequently investigated for all derivatives under various conditions. The parent 1-(1-tetralinylidene)tetralin underwent efficient oxidative electrocyclization. The 2,2,2′,2′-tetramethylated analogue was resistant towards photooxidation, however, its cis-isomer thermally reisomerized to the more stable trans-isomer. 相似文献
225.
Lu R Yang C Cao Y Wang Z Wada T Jiao W Mori T Inoue Y 《Chemical communications (Cambridge, England)》2008,(3):374-376
Enantiodifferentiating photoisomerization of (Z)-cyclooctene included and sensitized by m-methoxybenzoyl-beta-cyclodextrin gave chiral (E)-isomers in up to 46% enantiomeric excess, which is the highest value ever reported for supramolecular photochirogenesis with analogous hosts, thus demonstrating the crucial role of the sensitizer-spacer moiety in supramolecular photochirogenic systems. 相似文献
226.
The reaction of 16α-hydroxyestrone with hexacyanoferrate(III) and arginine in alkaline solution at 95°C produces a fluorescent compound that is measured at 490 nm (λ(ex) = 395 nm). Most other steroids do not interfere. The calibration is linear for 0.5–50 μg of analyte. 相似文献
227.
Ho Sik Kim Tong Eun Kim Sam Tag Kwag Yong Tae Park Young Seuk Hong Yoshihisa Okamoto Yoshihisa Kurasawa 《Journal of heterocyclic chemistry》1997,34(5):1539-1542
The reaction of the 6-chloro-2-(1-methyl-2-thiocarbamoylhydrazino)quinoxaline 4-oxides 3a-d with trifluoroacetic anhydride gave the 2-(N-aryl)trifluoroacetamido-8-chloro-4-methyl-4H-1,3,4-thiadiazino-[5,6-b]quinoxalines 7a-d , respectively, while the reflux of compounds 3a-c in N,N-dimethylformamide afforded the mesoionic triazolo[4,3-a]quinoxaline 4 . Hydrolysis of compounds 7a-d with triethylamine/water provided the 2-arylamino-8-chloro-4-methyl-4H-1,3,4-thiadiazino[5,6-b)]quinoxalines 8a-d , respectively. 相似文献
228.
Suzuki M Watanabe K Fujiwara S Kurasawa T Wakabayashi T Tsuzuki M Iguchi K Yamori T 《Chemical & pharmaceutical bulletin》2003,51(6):724-727
Two norcarotenoids, 1 and 2, related to peridinin (3) were isolated from the cultured dinoflagellate of the genus Symbiodinium, a symbiont of the Okinawan soft coral Clavularia viridis, which contains in abundance antitumor marine prostanoids such as clavulones. The structures of 1 and 2 were elucidated on the basis of spectroscopic analysis. These compounds showed significant growth-inhibitory activity in vitro toward cancer cells. Analysis of fatty acids of the dinoflagellate was also carried out, suggesting that the marine prostanoids are produced by the host soft coral itself. 相似文献
229.
Yoshihisa Takaishi 《中国化学快报》2008,19(4):450-452
A new iridoid glycoside,versibirioside(1),and a known iridoid glycoside,verbaspinoside(2),were isolated from the whole plant of Veronica sibirica L.Their structures were elucidated by spectroscopic methods,including 2D-NMR spectra. 相似文献
230.
The UV.-isomerisation of 11-oxo-14β,17α-pregnane 9 to the 11,19-cyclo-derivative 11 is described. In addition the Pb(OAc)4-fragmentation of photoproduct 11 was investigated. 11 yielded besides the expected 11-oxo-19-hydroxy-pregnane 18 the novel 9,11-seco-11,19-cyclosteroid 19 . The structure of 19 was established by chemical transformations and subsequently confirmed by X-ray analysis [2]. 相似文献