Antioxidant Activity of Intramolecularly Hydrogen Bonded 2-Aminophenol

The antioxidant activities of five classes of 2-aminophenol (model compound) and 2-aminophenols with substituent at the phenyl ring were studied in the oxidation of tetralin induced by an azo-initiator at 61℃. 2-Aminophenols with electron-donating groups at the 4-position exhibited higher antioxidant activity than that of the model compound. However, introduction of the methoxy group at the 4-position reduced the antioxidant activity by 8 % that of the model compound. 2-Aminophenols with electron-donating groups at the 5-position have little effect on the antioxidant activity. 2-Aminophenols with electron-donating groups at both the 4- and 6-positions showed remarkable antioxidant activity. These results were discussed in terms of the hydrogen bonding effect and bond dissociation energies of the O-H and NH-H bonds

De-tert-butylation of poly(N-tert-butyl-N-n-propylacrylamide) : Stereochemical analysis at the triad level

The stereochemical analysis of polymers derived from N,N-disubstituted acrylamides is usually difficult. The diad tacticity can be determined from the 1H NMR signals of the main-chain methylene groups. However, the splitting because of the configurational sequences is poor, even in 13C NMR, which does not allow determination of the tacticity at the triad level. In contrast, the stereochemical analysis of polymers derived from N-monosubstituted acrylamides is easily conducted and the triad tacticity can be determined from the 13C signals of the main-chain methine groups. Thus, stereochemical analysis of N,N-disubstituted polymers should be able to be conducted if the polymers are transformed into N-monosubstituted polymers with retention of the configurational sequence. Poly(N-tert-butyl-N-n-propylacrylamide) [poly(TBNPAAm)] was radically prepared, and de-tert-butylation was conducted by treatment with Sc(OTf)3 in a mixed solvent of CH3CN and 1,4-dioxane at 50, 80, and 110 °C. 1H NMR analysis of the resulting polymers indicated quantitative conversion after 72 h, regardless of the temperature. 13C NMR analysis of the transformed polymers confirmed that the configurational sequences were retained during the reaction. Thus, the triad stereochemical analysis of N,N-disubstituted polymers was successfully conducted by de-tert-butylation as a polymer reaction, followed by 13C NMR analysis of the transformed polymers

Introduction to Nuclear Reactor Experiments

This open access book is a pedagogical text on nuclear reactor experiments, covering almost all the experiments that can be carried out at the University Training Reactor, Kindai University (UTR-KINKI) with respect to reactor physics and radiation detection, and additionally including academic materials of test and research reactors, nuclear instrumentation, nuclear laws and regulations, in this main body. The book is an excellent primer for students who are interested in reactor physics, radiation detection, nuclear laws and regulations at universities, and the best textbook for students who have started to study the nuclear energy related fields to understand the basic theories and principles of the experiments in the fields of reactor physics and radiation detection. UTR-KINKI has been used for educational reactor experiments and basic research in a wide range of fields related to the use of radiation (neutrons, gamma-ray, beta-ray, alpha-ray, and X-ray), including reactor physics, radiation detection, radiation health physics, activation analysis, radiation biology, medical applications and archaeology. Also, UTR-KINKI has been actively engaged in nuclear education with its long history of operation, and has gained extensive experience in educational activities for undergraduate and graduate students, elementary, junior high and high school teachers, junior high and high school students, and general audiences

Benchmarks of subcriticality in accelerator-driven system at Kyoto University Critical Assembly

Basic research on the accelerator-driven system is conducted by combining U-235-fueled and Th-232-loaded cores in the Kyoto University Critical Assembly with the pulsed neutron generator (14 MeV neutrons) and the proton beam accelerator (100 MeV protons with a heavy metal target). The results of experimental subcriticality are presented with a wide range of subcriticality level between near critical and 10,000 pcm, as obtained by the pulsed neutron source method, the Feynman-alpha method, and the neutron source multiplication method

Fabrication and Fracture Toughness of CNTs/Alumina Composites with Fine Microstructures

ArticleKey Engineering Materials. 617: 205-208 (2014)journal articl

Deep intronic GPR143 mutation in a Japanese family with ocular albinism

Deep intronic mutations are often ignored as possible causes of human disease. Using whole-exome sequencing, we analysed genomic DNAs of a Japanese family with two male siblings affected by ocular albinism and congenital nystagmus. Although mutations or copy number alterations of coding regions were not identified in candidate genes, the novel intronic mutation c.659-131 T > G within GPR143 intron 5 was identified as hemizygous in affected siblings and as heterozygous in the unaffected mother. This mutation was predicted to create a cryptic splice donor site within intron 5 and activate a cryptic acceptor site at 41nt upstream, causing the insertion into the coding sequence of an out-of-frame 41-bp pseudoexon with a premature stop codon in the aberrant transcript, which was confirmed by minigene experiments. This result expands the mutational spectrum of GPR143 and suggests the utility of next-generation sequencing integrated with in silico and experimental analyses for improving the molecular diagnosis of this disease

Deposition of Apatite on Carbon Nanofibers in Simulated Body Fluid

Carbon nanofibers (CNFs) were soaked in 1.5 simulated body fluid (1.5 SBF) in which inorganic ion concentrations are 1.5 times as high as those in the standard SBF. The influence of the CNFs content in 1.5 SBF and pretreatment of the CNFs on the biomimetical deposition of apatite were investigated. The spherical bone-like apatite particles were deposited on the pristine CNFs soaked in 1.5 SBF. Amount of deposited apatite per a unit of CNFs increased with a decrease in the CNFs content in 1.5 SBF, and it decreased markedly when the CNFs were pretreated with concentrated sulfuric acid/nitric acid (3 : 1 v/v) mixture for longer periods. Such results suggest that too many nucleation sites of apatite, which were functional groups, such as carboxyl and hydroxyl groups, existed on the CNFs in the 1.5 SBF, and most embryos formed on the sites could not grow to critical nuclei and furthermore did not grow to apatite.ArticleJOURNAL OF NANOMATERIALS. 2011:935320 (2011)journal articl

Neutron Generation Time in Highly-Enriched Uranium Core at Kyoto University Critical Assembly

At the Kyoto University Critical Assembly experiments on kinetics parameters are carried out at near-critical configurations, supercritical and subcritical states, in the thermal neutron spectrum made with a highly enriched uranium fuel. The main calculated kinetics parameters, the effective delayed neutron fraction (βeff) and the neutron generation time (Ʌ), are used effectively for the estimation of experimental parameters, and the accuracy of experiments on prompt neutron decay constant (α) and subcriticality (ρ$) in dollar units is attained by the numerical results of βeff and Ʌ. Furthermore, the value of βeff/Ʌ is experimentally deduced with the use of the experimental results of α and ρ$, ranging between 250 and −80 pcm. Thus, the experimentally deduced values of βeff/Ʌ that reveal good accuracy through a comparison with those by the MCNP6.1 calculations with JENDL-4.0 are then taken as an index of Ʌ by introducing an acceptable assumption of βeff at near-critical configurations. From the results of experimental and numerical analyses, the experimental value of βeff/Ʌ is important for the validation of Ʌ since kinetics parameters are successfully obtained from the clean cores of near-critical configurations in the thermal neutron spectrum