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排序方式: 共有236条查询结果,搜索用时 15 毫秒
101.
Kazuhiro Toyoda Eri Yasunaga Masanobu Niwa Yuko Ohwatari Atsushi Nakashima Yoshishige Inagaki Yuki Ichinose Tomonori Shiraishi 《Journal of General Plant Pathology》2012,78(5):311-315
Blue native PAGE analysis for cell wall proteins from pea epicotyls demonstrated that cell wall-associated ecto-apyrase (ATPase) formed a large protein complex(es) ranging from 450 to 900?kDa; one of the components of the complex was copper amine oxidase (CuAO), which catalyzes the oxidation of amines with the subsequent generation of ammonia and hydrogen peroxide. CuAO activity was coordinately regulated in vitro with ATP-hydrolyzing activity by an elicitor and a suppressor from Mycosphaerella pinodes. Moreover, treatment of cell wall proteins with the suppressor caused the appearance of the apyrase monomer. On the basis of these results, M. pinodes may target the apyrase-containing protein complex(es) of the host to attenuate cell wall-based, extracellular defense(s) including the production of hydrogen peroxide. 相似文献
102.
Unno T Tamemoto K Yayabe F Kakuda T 《Journal of agricultural and food chemistry》2003,51(23):6893-6898
There is great interest in the nutritional potential of (-)-epicatechin, a common polyphenolic constituent of many foods and beverages, because of its potent antioxidant capacity. To better evaluate the biological role of (-)-epicatechin, we studied the urinary excretion of 5-(3',4'-dihydroxyphenyl)-gamma-valerolactone, a ring-fission metabolite of (-)-epicatechin by intestinal microflora, in rats as well as its antioxidant activity in vitro. The method for measuring the urinary levels of (-)-epicatechin and 5-(3',4'-dihydroxyphenyl)-gamma-valerolactone was based on the enzymatic hydrolysis of beta-glucuronidase and sulfatase, and was subsequently determined by HPLC coupled to an electrochemical detector. Following administration of (-)-epicatechin at doses of 0, 20, 40, and 80 mumol per rat, (-)-epicatechin and 5-(3',4'-dihydroxyphenyl)-gamma-valerolactone were excreted into the urine within 24 h in a dose-dependent manner. Urinary 5-(3',4'-dihydroxyphenyl)-gamma-valerolactone was mostly in the conjugated form, with a higher ratio of conjugation than (-)-epicatechin. We assessed the relative antioxidant potentials for scavenging radicals in the aqueous phase as expressed in the Trolox equivalent antioxidant capacity (TEAC). The results demonstrated that the degradation of (-)-epicatechin into 5-(3',4'-dihydroxyphenyl)-gamma-valerolactone attenuated the antioxidant ability of the former. However, 5-(3',4'-dihydroxyphenyl)-gamma-valerolactone showed stronger antioxidant activity than l-ascorbic acid. These results led us to suppose that 5-(3',4'-dihydroxyphenyl)-gamma-valerolactone, a microbial metabolite of (-)-epicatechin, circulating in the body may also at least be biologically active in terms of contributing to its combined antioxidant effect. 相似文献
103.
Yasuo Yamagiwa Yoshishige Inagaki Yuki Ichinose Kazuhiro Toyoda Mitsuro Hyakumachi Tomonori Shiraishi 《Journal of General Plant Pathology》2011,77(6):336-341
A plant-growth-promoting fungus (PGPF), Talaromyces sp. was isolated from an agricultural field in southwestern Japan. We found that this fungus emitted several terpenoid-like
volatiles including β-caryophyllene. Then we investigated the effect of β-caryophyllene on promoting the growth and inducing resistance of Brassica campestris L. var. perviridis. The compound significantly enhanced the growth of seedlings and their resistance to Colletotrichum higginsianum. On the basis of these results, we discuss the role of β-caryophyllene in the activities of PGPF. 相似文献
104.
Kohsaka Y Taylor C Fujita K Schmidt A Lupien C Hanaguri T Azuma M Takano M Eisaki H Takagi H Uchida S Davis JC 《Science (New York, N.Y.)》2007,315(5817):1380-1385
Removing electrons from the CuO2 plane of cuprates alters the electronic correlations sufficiently to produce high-temperature superconductivity. Associated with these changes are spectral-weight transfers from the high-energy states of the insulator to low energies. In theory, these should be detectable as an imbalance between the tunneling rate for electron injection and extraction-a tunneling asymmetry. We introduce atomic-resolution tunneling-asymmetry imaging, finding virtually identical phenomena in two lightly hole-doped cuprates: Ca(1.88)Na(0.12)CuO(2)Cl2 and Bi2Sr2Dy(0.2)Ca(0.8)Cu2O(8+delta). Intense spatial variations in tunneling asymmetry occur primarily at the planar oxygen sites; their spatial arrangement forms a Cu-O-Cu bond-centered electronic pattern without long-range order but with 4a(0)-wide unidirectional electronic domains dispersed throughout (a(0): the Cu-O-Cu distance). The emerging picture is then of a partial hole localization within an intrinsic electronic glass evolving, at higher hole densities, into complete delocalization and highest-temperature superconductivity. 相似文献
105.
Sapflow characteristics and climatic responses in three forest species in the semiarid Loess Plateau region of China 总被引:5,自引:0,他引:5
Sheng Du Yi-Long Wang Tomonori KumeJian-Guo Zhang Kyoichi OtsukiNorikazu Yamanaka Guo-Bin Liu 《Agricultural and Forest Meteorology》2011,151(1):1-10
In the semiarid Loess Plateau region of China, ecosystems are frequently affected by water shortages. Late spring and early summer are periods when forest communities tend to suffer from soil drought. To clarify the water-use strategies of the main species in this area, the xylem sap flow of trees from three species in the field was monitored for three successive periods in summer using Granier-type thermal dissipation probes. Vapor pressure deficit (VPD), solar radiation (Rs) and soil moisture had varying influences on sap flux density (Fd) in the species. Normalized Fd values could be fitted to VPD using an exponential saturation function, but the fit was better with a derived variable of transpiration (VT), an integrated index calculated from VPD and Rs. From differences in model coefficients, the species were roughly divided into two types with contrasting drought sensitivity. The exotic Robinia pseudoacacia was defined as drought-sensitive type. It showed higher sapflow increases in response to rainfall, suggesting a high water demand and high influence of soil water conditions on transpiration. This species showed relatively late stomatal response to increasing VPD. The wide-peak pattern of diurnal sapflow course also suggests relatively low stomatal regulation in this species. The drought-insensitive type consisted of the naturally dominant Quercus liaotungensis and an indigenous concomitant species, Armeniaca sibirica, in the forest. The sap flow of these species was not very sensitive to changes in soil water conditions. The results suggest that typical indigenous species can manage the water consumption conservatively under both drought and wet conditions. Variations in water use strategies within indigenous species are also detected. 相似文献
106.
Neurosecretory cell: capable of conducting impulse in rats 总被引:6,自引:0,他引:6
Electriic vtinulation of the rat neurohypophlysis in Situ evoked the unit action potentials. in the supraoptic nucleus. Compound and unit action potentials. were recorded from the isolated neurohypophysis stimulation. The applicaition of solutions high in potassium or devoid of sodium made the neurohypophysis inexcitable. Mammalian neurosecretsecretory cells have the neuronal properties generation and conduction of action potentials. 相似文献
107.
It has been hitherto indicated that the translocation of phosphorus has the biochemical response with carbohydrates in the plant. From that point of view, many workers have shown the variable effects of sucrose on the absorption and translocation of foliar applied phosphoric acid. Yatazawa et al. (1 and 2) found that in young wheat plants, phosphorus applied together with 5% sucrose on the leaf surface was absorbed about 3 times faster as that of the phosphorus without sucrose. Gustafson (3) has also obtained the same results when the absorption and translocation of cobalt from 60CoCl2 solution by leaves of beans kept in the dark was studied. The addition of sucrose to the applied solution promoted absorption and translocation considerably. Teubner et al. (4) indicated that 2% sucrose applied to plants grown in the light caused a marked depression of initial uptake of phosphorus, and this depression was not apparent after 12 hours of absorption, nor could it be seen with plants grown in the dark. 相似文献
108.
Shuichi Ishizawa Tatsuhiko Suzuki Tomonori Koda Osamu Sato 《Soil Science and Plant Nutrition》2013,59(1):113-128
Introduction Joffell described in his book “Pedology” that in the process of weathering, autotrophic organisms grow on the bare surface of rocks and their metabolic products contribute much to the weathering. Treub2) observed also that the surface of volcanic ash was covered by the vigorous growth of algae in less than three years after the eruption of Krakatoa. From these statements it appears evident that microorganisms play an important part through the production of organic matter at the early period of soil formation. As soil-forming-process advances, however, microBrganisms are replaced by the higher chlorophyllbearing plants with regards to organic matter production in land, and they become more important in the decomposition of than in the production of organic matter. 相似文献
109.
In previous papers (1–5), it was concluded that among the many organic acids produced in the mixed culture of R. capsulatus with ether heterotrophic bacteria, especially pyruvic acid is a hydrogen donor for the nitrogen fixation by R. capsulatus. All previous experiments were dove under a light condition. In this paper, the nitrogen fixation under a dank conditien is presented, and the difference between light and dark condition is discussed. 相似文献
110.
Keishi?MatsudaEmail author Shinsuke?Torisawa Tomonori?Hiraishi Katsuaki?Nashimoto Katsutaro?Yamamoto 《Fisheries Science》2005,71(5):1136-1142
ABSTRACT: In this study, the visual acuity, visual accommodation, and spectral sensitivity of the elkhorn sculpin were determined. The elkhorn sculpin Alcichthys alcicornis is a typical groundfish that has conspicuously large eyes. They are caught by bottom gillnets, trawl nets, bottom line angling, and other fishing methods. Although fish behavior arising from visual stimuli is important in these fishing methods, there is little information available regarding the visual sensitivity of the elkhorn sculpin . Three specimens, with total lengths of 300–310 mm, were studied. Visual acuity was calculated, from the maximum cone density in the retina, to be between 0.10 and 0.14. The minimum separable angles were calculated to be 7.14–10.37 min. Measurement of lens movement in five specimens indicated that the near-point distance was between 0.87 and 1.53 times the total length. Lens direction was estimated to be 11–22° in the downward visual axis. Spectral sensitivity was also determined electrophysiologically by recording S-potentials. Three types of response were obtained from 21 specimens, including L responses that showed hyperpolarization at all wavelengths of stimulating light, and two C responses that showed wavelength-dependent hyperpolarization and depolarization. Based on these results, the elkhorn sculpin has color vision and its sensitivity is most acute in light with a wavelength of 554 nm. 相似文献