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排序方式: 共有358条查询结果,搜索用时 15 毫秒
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353.
Ohta K Onoda S Hirose K Sinmyo R Shimizu K Sata N Ohishi Y Yasuhara A 《Science (New York, N.Y.)》2008,320(5872):89-91
Recent discovery of a phase transition from perovskite to post-perovskite suggests that the physical properties of Earth's lowermost mantle, called the D' layer, may be different from those of the overlying mantle. We report that the electrical conductivity of (Mg0.9Fe0.1)SiO3 post-perovskite is >10(2) siemens per meter and does not vary greatly with temperature at the conditions of the D' layer. A post-perovskite layer above the core-mantle boundary would, by electromagnetic coupling, enhance the exchange of angular momentum between the fluid core and the solid mantle, which can explain the observed changes in the length of a day on decadal time scales. Heterogeneity in the conductivity of the lowermost mantle is likely to depend on changes in chemistry of the boundary region, not fluctuations in temperature. 相似文献
354.
The extract of the sea hare, Aplysia kurodai, showed neurotrophic activity toward rat pheochromocytoma (PC-12) cells. Bioassay-guided purification afforded two active compounds, which were subsequently identified to be parguerol and isoparguerol by spectroscopic analysis. It was found that both parguerol and isoparguerol induced neurite outgrowth in PC-12 cells at concentrations of 25 and 50 μM, respectively. 相似文献
355.
Doi H Touhata Y Shibata H Sakai S Urisu A Akiyama H Teshima R 《Journal of agricultural and food chemistry》2008,56(17):7625-7630
Among food allergens of tree nuts, walnuts are a frequent cause of adverse food reactions in allergic patients. A novel sandwich enzyme-linked immunosorbent assay (ELISA) for the detection and quantification of walnut soluble proteins in processed foods was developed. The sandwich ELISA is highly specific for walnut soluble proteins. The recovery ranged from 83.4 to 123%, whereas the intra- and interassay coefficients of variation were less than 8.8 and 7.2%, respectively. This study showed that the proposed method is a reliable tool for detection in the presence of hidden walnut proteins in processed foods. 相似文献
356.
Ryota Konda Seiichi Ohta Shigehiro Ishizuka Seiko Arai Saifuddin Ansori Nagaharu Tanaka Arisman Hardjono 《Soil biology & biochemistry》2008,40(12):3021-3030
We investigated spatial structures of N2O, CO2, and CH4 fluxes during a relatively dry season in an Acacia mangium plantation stand in Sumatra, Indonesia. The fluxes and soil properties were measured at 1-m intervals in a 1 × 30-m plot (62 grid points) and at 10-m intervals in a 40 × 100-m plot (55 grid points) at different topographical positions of the upper plateau, slope, and valley bottom in the plantation. Spatial structures of each gas flux and soil property were identified using geostatistical analysis. The means (±SD) of N2O, CO2, and CH4 fluxes in the 10-m grids were 0.54 (±0.33) mg N m−2 d−1, 2.81 (±0.71) g C m−2 d−1, and −0.84 (±0.33) mg C m−2 d−1, respectively. This suggests that A. mangium soils function as a larger source of N2O than natural forest soils in the adjacent province on Sumatra during the relatively dry season, while CO2 and CH4 emissions from the A. mangium soils were less than or consistent with those in the natural forest soils. Multiple spatial dependence of N2O fluxes within 3.2 m (1-m grids) and 35.0 m (10-m grids), and CO2 fluxes within 1.8 m (1-m grids) and over 65 m (10-m grids) was detected. From the relationship among N2O and CO2 gas fluxes, soil properties, and topographic elements, we suggest that the multiple spatial structures of N2O and CO2 fluxes are mainly associated with soil resources such as readily mineralizable carbon and nitrogen in a relatively dry season. The soil resource distributions were probably controlled by the meso- and microtopography. Meanwhile, CH4 fluxes were spatially independent in the A. mangium soils, and the water-filled pore space appeared to mainly control the spatial distribution of these fluxes. 相似文献
357.
Atsushi Ohta Kyoko Yamane Taihachi Kawahara 《Genetic Resources and Crop Evolution》2017,64(5):889-899
This study examines the relationship between spike morphology and natural habitat for 84 accessions of four Aegilops species, belongs to section Sitopsis, Ae. bicornis, Ae. longissima, Ae. searsii, and Ae. sharonensis in genus Aegilops, section Sitopsis, wild relatives of Triticum aestivum L. These species are considered valuable genetic resources for future cultivation and breeding of domesticated wheat. The goals of the study were to: (1) document variation in spike morphology among these four species; (2) examine the relationship between spike morphology and native habitat; (3) document geographical distribution of distinct spike morphology; and (4) examine the relationship between spike morphology and heading time and value for these four species. The results reveal significant differences in spike morphology among species of section Sitopsis. The most noteworthy variation involved the absence/presence of lateral awn, such that species with lateral awn were restricted in coastal, though species without lateral awn were mainly distributed in inland. This suggests that local climate may be a determinant of variation in lateral awn, and that this trait may be subject to convergent evolution. Differences in heading time in sympatric area were also observed. The differences may enhance species divergence and could represent a lead speciation event. The results of this study will facilitate identification of populations or accessions of wild wheat with favorable traits and/or novel adaptive genes. 相似文献
358.
Effects of mycoplasmal pneumonia of swine (MPS) lung lesion‐selected Landrace pigs on MPS resistance and immune competence in three‐way crossbred pigs
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Liushiqi Borjigin Tomoyuki Shimazu Yuki Katayama Kouichi Watanabe Haruki Kitazawa Sang‐gun Roh Hisashi Aso Kazuo Katoh Masahiro Satoh Yoshihito Suda Akiko Sakuma Mituru Nakajo Keiichi Suzuki 《Animal Science Journal》2017,88(4):575-585
To clarify the genetic influence of mycoplasmal pneumonia of swine (MPS) lesion‐selected Landrace (La) on MPS resistance and immune characteristics in three‐way crossbred pigs (LaWaDa), the LaWaDa pigs were compared with the non‐selected crossbred (LbWbDb) and purebred (La) pigs. The MPS lesion score in the three lines was as follows: La line < LaWaDa line < LbWbDb line, with significant differences among the lines. The proportions of myeloid cells and T cells were lower and higher, respectively, in the LaWaDa pigs compared with those in the other two lines. Messenger RNA (mRNA) expression of interleukin (IL)‐6, IL‐10, transforming growth factor‐β, and interferon‐γ in peripheral blood was significantly increased after vaccination in the La and LaWaDa lines. IL‐4 mRNA expression in the LaWaDa line was intermediate to the La and LbWbDb lines. Furthermore, principal component analysis for immune traits and MPS lesions was executed to clarify the characteristics of each pig line. These findings suggest that the immune responses in the three pig lines are genetically distinct and that MPS resistance and some immunity characteristics from the La line were transmitted to the three‐way crossbred pigs. 相似文献