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41.
42.
Six new β-carboline-type indole alkaloid glycosides, ophiorrhisides A–F (16), were isolated from Ophiorrhiza trichocarpon (Rubiaceae) collected in Thailand. Ophiorrhisides A (1) and B (2) possess a lactam function in the C ring and a unique biose residue in the molecule. Ophiorrhiside F (6) has a highly oxidized C ring with a 1,2-dicarbonyl function at C-5 and C-6 positions as well as a double bond between C-3 and C-14.  相似文献   
43.
Gas-flow ionization chambers for radioisotope (RI) monitoring systems at RI institutes throughout Japan are commonly used to measure RIs which leak from the RI institutes. Before the Japan’s 2011 Tohoku earthquake [11 March 2011, moment magnitude (M w) 9.0], ionization current data measured with a gas-flow ionization chamber at the RI institute of Fukushima Medical University were found to change. The question we must raise is whether the variation ionization current can be considered to the variation of outdoor radon concentration. The conversion factors (from ionization current to radon concentration in air) of the gas-flow ionization chamber can be obtained by measuring four levels of radon concentration (outdoor air, indoor air, high level and radon-free gas) with an AlphaGUARD monitor and the chamber itself. The two gas-flow ionization chambers consist of the air intake and terminal exhaust duct of the RI institute. It was found that the radon concentration in the exhaust air was the same as that in the air intake. This study provided evidence that variations of outdoor radon concentration could be determined using gas-flow ionization chambers for RI monitoring systems.  相似文献   
44.
The principal purpose of this study is to present some of the fundamental data which might be used in the prediction of soil trafficability. These data are based on some sets of random cone index measurements which were taken from the areas of interest. In all cases, it was assumed that the individual measurements of the cone index being investigated would be independent. It is shown that the cone indices at critical layer depth can be regarded as normal random variables. The discussion in this study may be valid for the probabilistic approach of soil trafficability  相似文献   
45.
The maximum axial trapping efficiency Qmax has been measured in water, ethanol, butanol and octanol for polystyrene latex spheres having a diameter of 2–15μm. The effects of the diameter of the particle as well as the refractive index and the viscosity of surrounding medium have been investigated. For particles of d≥7 μm, Qmax is almost independent of particle size, while it decreases as the diameters decrease to d≦5 μm. It is also noted that Qmax is affected by the viscosity rather than the refractive index of the surrounding medium.  相似文献   
46.
Phosphorus nuclear magnetic resonance with surface coils was used to investigate the regional metabolism of the rat brain in vivo under conditions of normoxia, severe hypoxemia, partial necrosis, and partial ischemia. The results show an increase in sugar phosphate and/or inorganic phosphate with injury in accordance with in vivo assays. The technique provides a powerful means of monitoring the metabolism of stroke and its response to therapy in vivo.  相似文献   
47.
Right on Q: The first asymmetric total synthesis of (-)-huperzine-Q, which possesses six stereogenic centers and a spiroaminal moiety, has been achieved in 19 steps and 16.4?% overall yield. This synthesis involved a novel stereoselective Pauson-Khand reaction, a vinyl Claisen rearrangement, and a biomimetic spiroaminal formation. TBDPS=tert-butyldiphenylsilyl.  相似文献   
48.
The shape of the precipitates on sol–gel derived SiO2–TiO2 coatings at the negative electrode changed from granular to ramiform by applying an electric field to the substrates during a hot water treatment, whereas such changes in the shape of titania nanocrystals with the electric field were not observed at the positive electrode. The granular and ramiform precipitates were identified as anatase (TiO2) and hydrated titania (n(TiO2) · mH2O), respectively. The ramiform shape of the titania precipitates became significant with increasing the applied voltage, while the coatings gradually became dark-colored due to the reduction of Ti4+ to Ti3+. The coatings with ramiform precipitates showed an excellent wettability for water.  相似文献   
49.
Anti-rheumatoid arthritis (RA) effects of α-tocopherol (α-T) have been shown in human patients in a double-blind trial. However, the effects of α-T and its derivatives on fibroblast-like synoviocytes (FLS) during the pathogenesis of RA remain unclear. In the present study, we compared the expression levels of genes related to RA progression in FLS treated with α-T, succinic ester of α-T (TS), and phosphate ester of α-T (TP), as determined via RT-PCR. The mRNA levels of interleukin (IL)-6, tumor necrosis factor-α (TNF-α), matrix metalloproteinase (MMP)-3, and MMP-13 were reduced by treatment with TP without cytotoxicity, while α-T and TS did not show such effects. Furthermore, intraperitoneal injection of TP ameliorated the edema of the foot and joint and improved the arthritis score in laminarin-induced RA model mice. Therefore, TP exerted anti-RA effects through by inhibiting RA-related gene expression.  相似文献   
50.
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