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91.
Ryohei Sugita Natsuko I. Kobayashi Atsushi Hirose Yoshimi Ohmae Keitaro Tanoi Tomoko M. Nakanishi 《Journal of Radioanalytical and Nuclear Chemistry》2013,298(2):1411-1416
We have developed a real-time radioisotope imaging system (RRIS) that can nondestructively trace 14C-labeled chemicals in plants. In an experiment, after feeding 14CO2 to a plant, the plant was fixed inside a box where lighting was regulated, and beta rays emitted from the 14C in the plant were intermittently imaged using the developed system. As a first step, using a series of standard sources of 14C, the data depth and detection limits of the 14C images captured by the RRIS were evaluated for various integral times. As a result, the linearity between the 14C activity and signal intensity was determined for the range 103. Next, the linearity was validated using plant (Arabidopsis thaliana) organs, resulting that the linearity was shown in the case of young leaf, but was not maintained in the thick organs, such as a flower, mature leaf, siliques, and stem. Considering the good correlation between the intensity by RRIS and the PSL value by an imaging plate (IP) as well as the relative low energy of beta rays emitted from 14C, the thickness of the organs would easily affect the quantitativity of the RRIS as well as an IP. Our findings prove that sequential images of 14C in a living plant sample in a regulated light and air environment can be nondestructively analyzed using the developed system, whose quantitativity is similar to that of an IP. 相似文献
92.
93.
94.
C. Funayama T. Furukawa T. Sato Y. Ichikawa Y. Ohtomo Y. Sakamoto S. Kojima T. Suzuki C. Hirao M. Chikamori E. Hikota M. Tsuchiya A. Yoshimi C. P. Bidinosti T. Ino H. Ueno Y. Matsuo T. Fukuyama K. Asahi 《Hyperfine Interactions》2015,232(1-3):59-66
We demonstrate spin-exchange optical pumping of 129Xe atoms with our newly made laser system. The new laser system was prepared to provide higher laser power required for the stable operation of spin maser oscillations in the 129Xe EDM experiment. We studied the optimum cell temperature and pumping laser power to improve the degree of 129Xe spin polarization. The best performance was achieved at the cell temperature of 100 °C with the presently available laser power of 1 W. The results show that a more intense laser is required for further improvement of the spin polarization at higher cell temperatures in our experiment. 相似文献
95.
A redox-photosensitized reaction of indene 2 using a photosensitive surfactant 1a in an oil-in-water emulsion proceeded efficiently to give alcohol 3 as a major product and is strongly influenced by the oil droplet size and surfactant charge. 相似文献
96.
[reaction: see text] Aryl ketones were reduced to the corresponding alcohols with excellent enantioselectivity (up to 99.7% ee) by Cl3SiH in the presence of a catalytic amount of N-formyl-alpha'-(2,4,6-triethylphenyl)-L-proline as an activator. Both carboxyl group at the alpha-position of the activator and 2,4,6-triethylphenyl group at the alpha'-position were critical for the high enantioselectivity. 相似文献
97.
Sueishi Y Yoshioka D Yoshioka C Yamamoto S Kotake Y 《Organic & biomolecular chemistry》2006,4(5):896-901
Using a competitive spin trapping method, relative spin trapping rates were quantified for various short-lived radicals (methyl, ethyl, and phenyl radicals). High static pressure was applied to the competitive spin-trapping system by employing high-pressure electron spin resonance (ESR) equipment. Under high pressure (490 bar), spin trapping rate constants for alkyl and phenyl radicals increased by 10 to 40%, and the increase was dependent on the structure of nitrone spin traps. A maximum increase was obtained when tert-butyl(4-pyridinylmethylene)amine N-oxide (4-POBN) was used as a spin trap. Activation volumes (DeltaDeltaV(double dagger)) for the two spin trapping reactions were calculated to be -17-(-9) cm(3) mol(-1) for the 4-POBN system. 相似文献
98.
Toshio Morikawa Xuezheng Li Eriko Nishida Seikou Nakamura Kiyofumi Ninomiya Hisashi Matsuda Yoshimi Oda Osamu Muraoka Masayuki Yoshikawa 《Helvetica chimica acta》2010,93(3):573-586
The MeOH extract from the flowers of Bellis perennis was found to show pancreatic‐lipase inhibitory activity (IC50 455 μg/ml). From the extract, seven new triterpene saponins named perennisaponins G ( 1 ; IC50 163 μM ), H ( 2 ; 137 μM ), I ( 3 ; 147 μM ), J ( 4 ; 148 μM ), K ( 5 ; 223 μM ), L ( 6 ; 81.4 μM ), and M ( 7 ; 195 μM ) were isolated as pancreatic lipase inhibitors. The stereostructures of 1 – 7 were elucidated on the basis of chemical and spectroscopic evidence. 相似文献
99.
Using a competitive nitric oxide (NO)-trapping method between Fe–dithiocarbamate (DTC) complexes and liposome-encapsulated
2-[4-trimethylammonio]-4,4,5,5-tetramethyl-imidazoline-1-oxyl 3-oxide (TMAPTIO), NO-trapping rates of Fe–DTC complexes in
the presence of phosphatidylcholine liposomes were quantified for five kinds of Fe–DTC complexes. We investigated how the
DTC ligand structure influences the NO-trapping rates of Fe–DTC complexes. The negatively charged liposomes give a higher
NO-trapping rate of Fe–DTC complexes than do the positively charged ones, suggesting that the presence of a charge on the
liposome surface affects the NO-trapping rate processes of Fe–DTC complexes. In addition, on the basis of the pressure dependence
experiments for the competitive reaction, we evaluated the difference in activation volumes between the NO-trapping reactions
by Fe–DTC complexes and TMA-PTIO, which allowed us to consider possible reaction mechanisms for the NO-trapping processes. 相似文献
100.
Yoshimi Egawa Hikoe Enomoto Ralph J. Faudree Hao Li Ingo Schiermeyer 《Journal of Graph Theory》2003,43(3):188-198
It is shown that if G is a graph of order n with minimum degree δ(G), then for any set of k specified vertices {v1,v2,…,vk} ? V(G), there is a 2‐factor of G with precisely k cycles {C1,C2,…,Ck} such that vi ∈ V(Ci) for (1 ≤ i ≤ k) if or 3k + 1 ≤ n ≤ 4k, or 4k ≤ n ≤ 6k ? 3,δ(G) ≥ 3k ? 1 or n ≥ 6k ? 3, . Examples are described that indicate this result is sharp. © 2003 Wiley Periodicals, Inc. J Graph Theory 43: 188–198, 2003 相似文献