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321.
The relativistic correction to the QCD static interquark potential at O(1/m) is investigated nonperturbatively for the first time by using lattice Monte Carlo QCD simulations. The correction is found to be comparable with the Coulombic term of the static potential when applied to charmonium, and amounts to one-fourth of the Coulombic term for bottomonium. 相似文献
322.
[Structure: see text] A trichloroacetamide group was converted to an isocyanate, which was in situ captured by a variety of alcohols in the presence of CuCl and n-BuN4Cl to afford the corresponding carbamates. The scope and limitation of this transformation are also described. 相似文献
323.
Eight alkenes reacted with 1,1′-dithiobis(1H-1,2,4-triazole) 4 at −15 °C to form the corresponding thiiranes in moderate to good yields. The thiiranations of anti- and syn-9,9′-bibenzonorbornenylidenes and cis- and trans-cyclooctenes with 4 proceeded with retention of configuration of the starting alkenes. 相似文献
324.
Miho Noguchi Ryoichi Hirayama Sergey Druzhinin Ryuichi Okayasu 《Radiation Physics and Chemistry》2009,78(12):1184-1187
Herbimycin A (HA), as in Geldanamycin, binds to conserved pockets of heat shock protein 90 (Hsp90) and inhibits its chaperone functions. Hsp90 plays an integral role in cancer cell growth and survival, because it maintains the stability of several key proteins by its chaperone's activity. It is known that some of the proteins associated with radiation responses are functionally stabilized by Hsp90. In this study, we investigated the effect of HA on radiosensitivity in human cancer cells and the mechanism related to the sensitization. In order to gain a mechanistic insight of this sensitization, we examined repair of DNA double-strand breaks (DSBs) in irradiated human cancer cells pre-treated with HA, as unrepaired DSBs are thought to be the main cause of radiation-induced cell death. Cellular radiosensitivity was determined by clonogenic assay, and the DSB rejoining kinetics was examined by constant field gel electrophoresis. SQ-5, a lung squamous carcinoma cell line, showed synergistic increase in radiosensitivity when cells were pre-treated with HA. In addition, HA significantly inhibited repair of radiation-induced DSBs. These results suggest that the combination of HA and ionizing radiation may be a useful therapeutic strategy for treating certain cancer cells. 相似文献
325.
The hydrogen storage properties of metal nanoparticles change with particle size. For example, in a palladium–hydrogen system, the hydrogen solubility and equilibrium pressure for the formation of palladium hydride decrease with a decrease in the particle size, whereas hydrogen solubility in nanoparticles of platinum, in which hydrogen cannot be stored in the bulk state, increases. Systematic studies of hydrogen storage in Pd and Pt nanoparticles have clarified the origins of these nanosize effects. We found a novel hydrogen absorption site in the hetero‐interface that forms between the Pd core and Pt shell of the Pd/Pt core/shell‐type bimetallic nanoparticles. It is proposed that the potential formed in the hetero‐interface stabilizes hydrogen atoms rather than interstitials in the Pd core and Pt shells. These results suggest that metal nanoparticles a few nanometers in size can act as a new type of hydrogen storage medium. Based on knowledge of the nanosize effects, we discuss how hydrogen storage media can be designed for improvement of the conditions of hydrogen storage. 相似文献
326.
Akiko Nagata Kazuto Iijima Ryota Sakamoto Yuka Mizumoto Miho Iwaki Masaki Takiwaki Yoshikuni Kikutani Seketsu Fukuzawa Minami Odagi Masayuki Tera Kazuo Nagasawa 《Molecules (Basel, Switzerland)》2022,27(8)
Blood levels of the vitamin D3 (D3) metabolites 25-hydroxyvitamin D3 (25(OH)D3), 24R,25-dihydroxyvitamin D3, and 1α,25-dihydroxyvitamin D3 (1,25(OH)2D3) are recognized indicators for the diagnosis of bone metabolism-related diseases, D3 deficiency-related diseases, and hypercalcemia, and are generally measured by liquid-chromatography tandem mass spectrometry (LC-MS/MS) using an isotope dilution method. However, other D3 metabolites, such as 20-hydroxyvitamin D3 and lactone D3, also show interesting biological activities and stable isotope-labeled derivatives are required for LC-MS/MS analysis of their concentrations in serum. Here, we describe a versatile synthesis of deuterium-labeled D3 metabolites using A-ring synthons containing three deuterium atoms. Deuterium-labeled 25(OH)D3 (2), 25(OH)D3-23,26-lactone (6), and 1,25(OH)2D3-23,26-lactone (7) were synthesized, and successfully applied as internal standards for the measurement of these compounds in pooled human serum. This is the first quantification of 1,25(OH)2D3-23,26-lactone (7) in human serum. 相似文献
327.
Yohei SAWAYA Miho SATO Masahiro ISHIZAKA Takahiro SHIBA Akira KUBO Tomohiko URANO 《Physical Therapy Research》2022,25(1):35
Objective: The maximum phonation time (MPT) is used to assess simple respiratory functions and can be performed anywhere without special instruments. We investigated the association between MPT and respiration, considering the future utilization of simple respiratory assessments during home-based physical therapy. Method: This cross-sectional study included 140 older adults enrolled in Japanese long-term care insurance (77 men, 63 women; mean age, 77.9±8.0 years). The participants performed the MPT, followed by spirometry. We analyzed the MPT of the three age groups, relative reliability of the MPT values, and the association between MPT and respiratory function. Results: We found that the MPT of older men requiring long-term care or support was related to age. The intraclass correlation coefficient of MPT was >0.8 for all groups. Only forced vital capacity was associated with MPT in the partial correlation and multiple regression analyses. Conclusion: MPT could be an alternative assessment of respiratory function in home-based physical therapy for older adults requiring long-term care or support. 相似文献
328.