969 resultados para Lignin contents
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IEECAS SKLLQG
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以甜高粱品种KFJT-CK及经过碳离子辐照选育出的早熟突变株KFJT-1为材料,用浓度分别为5%,10%和15%的聚乙二醇(PEG)6000模拟干旱对其进行胁迫处理,测定丙二醛(MDA)及脯氨酸(Pro)的含量。随着胁迫时间的延长和胁迫程度的增加,MDA含量持续升高;Pro含量在5%和10%PEG胁迫下持续升高,在15%PEG胁迫下先升高后降低。表明碳离子辐照可能使甜高粱膜脂过氧化特性发生改变,影响Pro的表达。为进一步研究碳离子束辐照对甜高粱的耐旱生理提供一定的基础,并为下一步的育种工作提供有用的参考。
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Ni0.65Zn0.35Cu0.1Fe1.9O4/SiO2 nanocomposites with different weight percentages of NiZnCu-ferrite dispersed in silica matrix were successfully fabricated by the sol-gel method using tetraethylorthosilicate (TEOS) as a precursor of silica, and metal nitrates as precursors of NiZnCu ferrite. The thermal decomposition process of the dried gel was studied by thermogravimetric analysis (TGA) and differential thermal analysis (DTA). The obtained Ni0.65Zn0.35Cu0.1Fe1.9O4/SiO2 nanocomposites were characterized by X-ray diffraction (XRD), transmission electron microscope (TEM), scanning electron microscope (SEM), Mossbauer spectroscopy and vibrating sample magnetometry (VSM). The formation of stoichiometric NiZnCu-ferrite dispersed in silica matrix is confirmed when the weight percentage of ferrite is not more than 30%. Samples with higher ferrite content have small amount of alpha-Fe2O3. The transition from the paramagnetic to the ferromagnetic state is observed as the ferrite content increases from 20 to 90wt%.
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Major, minor and trace elemental contents in northeast China soybeans were determined by using inductively, coupled plasma atomic emission spectrometry (ICP-AES). Three different sample digestion methods including two wet digestions, HNO3-HClO4 and HNO3-H2SO4 and a dry ash method were compared. Owing to the high oil content in soybeans, long time is needed and access acid should be added, with mixed acid digestion methods, which may result in higher sample blank. Therefore, the dry ask method would be more proper for the pre-treatment of soybean samples. Potassium and phosphorus are major elements in soybeans, so the effect of potassium and phosphorus on the other elements was investigated. Results showed that the potassium and phosphorus did not affect the determination. of other trace elements. There are not significant differences in trace elemental contents for the eleven northeast China soybeans.
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Multivariate classification methods were used to evaluate data on the concentrations of eight metals in human senile lenses measured by atomic absorption spectrometry. Principal components analysis and hierarchical clustering separated senile cataract lenses, nuclei from cataract lenses, and normal lenses into three classes on the basis of the eight elements. Stepwise discriminant analysis was applied to give discriminant functions with five selected variables. Results provided by the linear learning machine method were also satisfactory; the k-nearest neighbour method was less useful.
Changes in RNA, DNA, protein contents and growth of turbot Scophthalmus maximus larvae and juveniles
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The growth potential of turbot Scophthalmus maximus larvae and juveniles was studied using nucleic acid-based indices and protein variables. The experiment was carried out from 4 to 60 days post hatching (dph). A significant increase in instantaneous growth rate during metamorphosis and retarded growth rate during post-metamorphic phase were observed. Ontogenetic patterns of DNA, RNA and protein all showed developmental stage-specific traits. The RNA:DNA ratio decreased up to 12 dph, then increased rapidly till 19 dph and fluctuated until 35 dph followed by a decline to the end. The RNA:DNA ratio was positively correlated with growth rate of juveniles during the post-metamorphic phase, whereas this ratio was not a sensitive indicator of growth during the pre-metamorphic phase and metamorphosis. The protein:DNA ratio showed a similar tendency to the RNA:DNA ratio. Changes of DNA content and protein:DNA ratio revealed that growth of S. maximus performed mainly by hyperplasia from 4 to 12 dph and hypertrophy until 21 dph during the pre-metamorphic larval phase. Growth was dominantly hypertrophical from the early- to mid-metamorphosing phase and hyperplastic thereafter. The results show that the DNA content and protein:DNA ratio can evaluate growth rates of larval and juvenile S. maximus on a cellular level.
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To assess the medicinal value of cultural Anisodus tanguticus,the contents of four bioactive tropane alkaloids,anisodine,anisodamine,scopolamine and atropine,in cultural and wild materials were determined by the HPLC method.The results showed that content of each alkaloid in the aboveground parts of cultural and wild samples was lower than that in roots,and this explained why it was not the whole plant but the root that was used as medicinal materials.The content of each alkaloid in the roots of one-year cultural material was lower than that in the two-year plants.The discrepancy of the total of four alkaloids between one-year and wild plants is not significant.Moreover,the total of four alkaloids,and the contents of anisodine,scopolamine,and atropine in two-year plants were higher than those in wild plant.Thus there is medicinal value in the cultivated A.tanguticus as well as wild A.tanguticus,especially in the two-year cultural A.tanguticus.
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The effects of hypoxia on the levels of essential macroelements and trace elements (K, Na, Ca, Mg, Cu, Zn, Fe, and Mn) in the heart muscles of Wistar rats and plateau pikas (Ochotona curzoniae) were studied by atomic absorption spectrometry. Unlike the rat, the plateau pika is tolerant to hypoxia. The levels of K, Na, and the trace element Mn were not significantly changed in rat or pika hearts after exposure to hypoxia for 1, 10, or 25 d at simulated altitudes of 5000 and 7000 m. Other minerals (Ca, Mg, Cu, Zn, and Fe) were significantly affected by hypoxia and the levels followed different time-courses under different hypoxic regimes in these two animals. There were marked differences between the rat and pika in myocardial accumulation of essential elements such as Ca, which was increased to high levels in the rat but not affected in the pika. The results suggest that hypoxia affects animal physiological mechanisms by regulating the levels of essential elements.
The Studying of Washing of Arsenic and Sulfur from Coals Having Different Ranges of Arsenic Contents
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J. H. Macduff and A. K. Bakken. (2003). Diurnal variation in uptake and xylem contents of inorganic and assimilated N under continuous and interrupted N supply to Phleum pratense and Festuca pratensis. Journal of Experimental Botany, 54 (381) pp.431-444 Sponsorship: BBSRC / Norwegian Crop Research Institute RAE2008