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排序方式: 共有99条查询结果,搜索用时 218 毫秒
1.
Antoine LF Gady Freddy WK Hermans Marion HBJ Van de Wal Eibertus N van Loo Richard GF Visser Christian WB Bachem 《Plant methods》2009,5(1):13-14
Background
The establishment of mutant populations together with the strategies for targeted mutation detection has been applied successfully to a large number of organisms including many species in the plant kingdom. Considerable efforts have been invested into research on tomato as a model for berry-fruit plants. With the progress of the tomato sequencing project, reverse genetics becomes an obvious and achievable goal. 相似文献2.
3.
试验结果表明,发光网线应用于被动性张网渔具时,增产效果不明显,而且还必须考虑资源保护和解决光源激发问题。在拖网渔具上应用时,能提高渔获效率,夜间生产效果高于白天,而且调整方便。 相似文献
4.
Lee AW Chen TL Shih CM Huang CY Tsao NW Chang NC Chen YH Fong TH Lin FY 《Journal of agricultural and food chemistry》2010,58(24):12941-12949
Ursolic acid (UA), a triterpenoid compound found in plants, is used in the human diet and in medicinal herbs and possesses a wide range of biological benefits including antioxidative, anti-inflammatory, and anticarcinogenic effects. Endothelial expression of allograft inflammatory factor-1 (AIF-1) mediates vasculogenesis, and nitric oxide (NO) produced by endothelial NO (eNOS) represents a mechanism of vascular protection. It is unclear whether UA affects the neovascularization mediated by AIF-1 and eNOS expression. This study investigated the effects and mechanisms of UA on angiogenesis in vivo in hind limb ischemic animal models and in vitro in human coronary artery endothelial cells (HCECs). This study explored the impact of UA on endothelial cell (EC) activities in vitro in HCECs, vascular neovasculogenesis in vivo in a mouse hind limb ischemia model, and the possible role of AIF-1 in vasculogenesis. The results demonstrate that UA enhances collateral blood flow recovery through induction of neovascularization in a hind limb ischemia mouse model. In vitro data showed that UA increases tube formation and migration capacities in human endothelial cells, and exposing HCECs to UA increased AIF-1 expression through a NO-related mechanism. Moreover, UA administration increased capillary density and eNOS and AIF-1 expression in ischemic muscle. These findings suggest that UA may be a potential therapeutic agent in the induction of neovascularization and provide a novel mechanistic insight into the potential effects of UA on ischemic vascular diseases. 相似文献
5.
本文对40个云南高原甘薯地方品种种薯萌芽特性进行了比较研究,结果表明:“易门黄皮”、“蒙自黄心”、“卷叶”、“紫红皮”、“普洱黄山芋”、“红鸡窝”、“路南红皮”、“樱枝”、东川白花”等一批云南甘薯地方品种种薯萌芽能力强,出苗较早,幼苗生长状况较好,是选育甘薯新品种的重要亲本材料,亦可在生产上直接利用。 相似文献
6.
7.
Teaching reasoning 总被引:1,自引:0,他引:1
Twentieth-century psychologists have been pessimistic about teaching reasoning, prevailing opinion suggesting that people may possess only domain-specific rules, rather than abstract rules; this would mean that training a rule in one domain would not produce generalization to other domains. Alternatively, it was thought that people might possess abstract rules (such as logical ones) but that these are induced developmentally through self-discovery methods and cannot be trained. Research suggests a much more optimistic view: even brief formal training in inferential rules may enhance their use for reasoning about everyday life events. Previous theorists may have been mistaken about trainability, in part because they misidentified the kind of rules that people use naturally. 相似文献
8.
Bourges P Sidis Y Fong HF Regnault LP Bossy J Ivanov A Keimer B 《Science (New York, N.Y.)》2000,288(5469):1234-1237
A comprehensive inelastic neutron scattering study of magnetic excitations in the near optimally doped high-temperature superconductor YBa(2)Cu(3)O(6.85) is presented. The spin correlations in the normal state are commensurate with the crystal lattice, and the intensity is peaked around the wave vector characterizing the antiferromagnetic state of the insulating precursor, YBa(2)Cu(3)O(6). Profound modifications of the spin excitation spectrum appear abruptly below the superconducting transition temperature T(c), where a commensurate resonant mode and a set of weaker incommensurate peaks develop. The data are consistent with models that are based on an underlying two-dimensional Fermi surface, predicting a continuous, downward dispersion relation connecting the resonant mode and the incommensurate excitations. The magnetic incommensurability in the YBa(2)Cu(3)O(6+)(x) system is thus not simply related to that of another high-temperature superconductor, La(2-)(x)Sr(x)CuO(4), where incommensurate peaks persist well above T(c). The temperature-dependent incommensurability is difficult to reconcile with interpretations based on charge stripe formation in YBa(2)Cu(3)O(6+x) near optimum doping. 相似文献
9.
Fong DD Stephenson GB Streiffer SK Eastman JA Auciello O Fuoss PH Thompson C 《Science (New York, N.Y.)》2004,304(5677):1650-1653
Understanding the suppression of ferroelectricity in perovskite thin films is a fundamental issue that has remained unresolved for decades. We report a synchrotron x-ray study of lead titanate as a function of temperature and film thickness for films as thin as a single unit cell. At room temperature, the ferroelectric phase is stable for thicknesses down to 3 unit cells (1.2 nanometers). Our results imply that no thickness limit is imposed on practical devices by an intrinsic ferroelectric size effect. 相似文献
10.
试验以核桃仁和脱脂奶粉为原料,对核桃仁预处理、发酵剂的制备、酸奶原料配比及发酵时间等工艺进行了探讨,确定合理的制作工艺.研制出芳香浓郁,口感细腻的核桃酸奶。 相似文献