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1.
一秋龄性成熟中华绒螫蟹的生物学──1.外部形态特征及性腺变化 总被引：4，自引：0，他引：4
极大螺旋藻藻体ＳＯＤ聚丙烯酰胺梯度凝胶电泳呈现４条同工酶带,Ｈ２Ｏ２明显抑制该酶活性,ＫＣＮ对酶活性无影响,确认为Ｆｅ－ＳＯＤ。经硫酸铵分部盐析,离子交换柱层析及凝胶过滤,纯化到电泳单斑点均一程度。纯化的Ｆｅ－ＳＯＤ分子量为３９．３ＫＤ,亚基分子量为２０ＫＤ,金属元素分析表明,每个亚基含０．５５个Ｆｅ原子。该酶在紫外区最大吸收峰值为２７５．８ｎｍ,该酶氨基酸组成与蓝,绿藻和高等植物的Ｆｅ－ＳＯＤ相 相似文献
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对３个合成的含Ｆｅ~３＋的铁硅酸盐尖晶石γ－Ｆｅ_２ＳｉＯ_４进行了电子探针分析,并在２９８,１５０和９５Ｋ的温度下对它们进行了Ｍｏｓｓｂａｕｅｒ谱的测试．每个温度下的Ｍｏｓｓｂａｕｅｒ谱均由两个双峰组成．这两个双峰分别被指派给八面体位置上的Ｆｅ~２＋和四面体位置上的Ｆｅ~３＋,并且根据Ｍｏｓｓｂａｕｅｒ吸收面积给出了占位结果表明,Ｆｅ~３＋和少量的Ｓｉ~４＋分别占据在四面体和八面体位置上．根据Ｍｏｓｓｂａｕｅｒ分析所得到的占位,使用经过修正的公式,计算了八面体和四面体位置的平均键长．在此基础上,八面体和四面体的平均键长进而被用来计算含Ｆｅ~３＋的γ－Ｆｅ_２ＳｉＯ_４的晶胞参数和氧参数．此外,使用次近邻效应解释了含Ｆｅ~３＋的γ－Ｆｅ_２ＳｉＯ_４Ｍｏｓｓｂａｕｅｒ谱的Ｆｅ~３＋谱线的宽化现象。 相似文献
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对星叶石Ｋ_２Ｎａ（Ｆｅ,Ｍｎ,Ｍｇ,□）,［Ｔｉ_２（Ｓｔ_４Ｏ_（１２））_２｜ Ｏ_３］（ＯＨ,Ｆ）_４进行了晶体结构的精测, 求得晶胞参数：ａ＝０．５３５ ９（２）ｕｍ,ｂ＝１．１６１４（４）ｕｍ,ｃ＝１．１８６１（４）ｕｍ,α＝１１３．１６（２）°,β ＝１０３．０４（２）°,γ＝９４．５６（２）°．晶胞体积Ｖ＝０．６４９５（５）ｎｍ~３．单位晶胞中的分子数Ｚ＝１,空 间群为Ｐ１．结构测定的精度,其偏离因子为Ｒ＝０．０５７．根据其晶体结构的特征,与曾测 定的单斜星叶石 Ｋ_２ＮａＮａ（Ｆｅ,Ｍｎ）_４Ｍｇ_２Ｔｉ_２［Ｓｉ_４Ｏ_（１２）］_２（ＯＨ）_４（ＯＨ,Ｆ）_２对比,指出两者为不同种 矿物,建议单斜星叶石应重新命名．将星叶石、单斜星叶石、钡铁钛石及问叶石这一类 钛硅酸盐的结构与云母进行类比,提出了晶体化学中的功能性替代的概念 相似文献
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Wilhelm Bechteler 《国际泥沙研究》1996,(3)
ＳＥＤＩＭＥＮＴＡＴＩＯＮＩＮＬＯＷＨＥＡＤＲＩＶＥＲＲＥＳＥＲＶＯＩＲＳ￥ＷｉｌｈｅｌｍＢｅｃｈｔｅｌｅｒ（Ｐｒｏｆ．Ｄｒ．－Ｉｕｇ．ＩｎｓｔｉｔｕｔｅｏｆＨｙｄｒｏｓｃｉｅｎｃｅｓ，ＦｅｄｅｒａｌＡｒｍｅｄＦｏｒｃｅｓＵｎｉｖｅｒｓｉｔｙＭｕｎｉ... 相似文献
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O.K.Chedia 《内陆地震》1994,(2)
ＲＥＣＥＮＴＵＮＤＥＲＴＨＲＵＳＴＳＯＦＴＩＡＮＳＨＡＮＡＮＤＰＯＳＳＩＢＬＥＭＥＣＨＡＮＩＳＭＯＦＴＨＥＩＲＯＲＩＧＩＮ￥Ｏ．Ｋ．Ｃｈｅｄｉａ（ＩｎｓｔｉｔｕｔｅｏｆＳｅｉｓｍｏｌｏｇｙＡｃａｄｅｍｙｏｆＳｃｉｅｎｃｅｓＲｅｐｕｂｌｉｃｏｆＫｉｒｇ... 相似文献
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赣东北蛇绿混杂岩带中硅质岩的地球化学特征及构造意义 总被引：18，自引：0，他引：18
赣东北蛇绿混杂岩带中含晚古生代放射虫硅质岩的ＳｉＯ_２含量变化范围为 ７８．４０％～ ８９．２８％,Ｓｉ／Ａｌ＝ ６．３～２３,Ｓｉ／Ａｌ比和Ａｌ_２Ｏ_３呈很好的负相关关系,表明它们含有 较高比例的陆源泥质沉积物．硅质岩样品的Ａｌ_２Ｏ_３／（Ａｌ_２Ｏ_３＋Ｆｅ_２Ｏ_３）＝０．５１～０．９０,Ｃｅ／Ｃｅ~·＝ ０,９１～１．２２, Ｌａ_ｎ／Ｃｅ_ｎ＝ ０．７６～１．１１, Ｖ＜Ｍ２０μｇ／ｇ,Ｖ／Ｙ＜２．６,Ｔｉ／Ｖ＞４０,一致表明这些硅质 岩形成于与大陆地壳物质输入密切相关的大陆边缘环境,而与大洋盆地、洋中脊环境无 关．因此,这些晚古生代硅质岩既不属于～ １．０Ｇａ蛇绿岩套“三位一体”中的一部分,也 不支持晚古生代扬子和华夏两个块体之间存在深海大洋盆。 相似文献
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目的是探讨标记乳糖基白蛋白的超顺磁性氧化铁粒子（ＬＡＣ－ＨＳＡ－ＳＰＩＯ）作为配体与肝细胞膜去唾液酸糖蛋白受体（ＡＳＧ）特异性结合可能性;评价ＬＡＣ－ＨＳＡ－ＳＰＩＯ增强磁共振受体成像对大鼠微小肝癌灶的显示能力。方法：将Ｆｅ３＋Ｆｅ２＋混合液与ＬＡＣ－ＨＳＡ在碱性条件下制备出ＬＡＯ－ＨＳＡ－ＳＰＩＯ;应用 二乙基亚硝酸胺建立大鼠肝癌模型;电镜及Ｐｅｒｌｓ（普鲁士蓝）染色,观察ＬＡＣ－ＨＳＡ－ＳＰＩＯ在肝组织的颁;并比较ＬＡＣ－ＨＳＡ－ＳＰＩＯ增强前后大鼠肝癌的显示情况。得到结果是（１）Ｐｅｒｌｓ染色证实有ＬＡＣ－ＨＳＡ－ＳＰＩＯ分布到肝细胞浆内;电镜下也显示肝细胞膜表面及胞浆内有电子致密ＳＰＩＯ粒子分布;（２）注射小剂量ＬＡＣ－ＨＳＡ－ＳＰＩＯ可观察到明显明显肝脏强化效果,大鼠肝癌检出率由平扫３６．８％（７／１９）提高到７８％（１５／１９,Ｐ＜００１）。结论：ＬＡＣ－ＨＳＡ－ＳＰＩＯ是一种新型的具有肝细胞ＡＳＧ受体靶向性显影剂,对提高肝脏微小瘤灶检出率有章要价值。 相似文献
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This paper deals with the influence of different humic substances (HS) on the enzyme activity (EA) of the proteolytic enzyme pronase E. The EA was determined by analyzing the concentration of the amino acid valine hydrolyzed from caseine. For amino acid analysis, a flourescence detector was used after precolumn derivatization and HPLC-separation of the hydrolysis products. The data show that the presence of HS has no adverse effects on amino acid analysis. Based on this result, a decrease of EA was observed in the presence of HS acting as enzyme inhibitors. Clear inhibition effects could be seen for different fulvic acids (HO3 FA, FBR FA and FBR 1.0 FA) at concentrations of 150 mg/L. In case of FBI-2 FA, higher concentrations were necessary to decrease the EA significantly. At an inhibitor concentration of 1500 mg/L the EA was mostly found to be less than 50%. The standard deviations of the results don't allow a differentiation between the HS of different origin and treatment. Specifying HS according to their influence on EA has to remain uncertain. As shown in a kinetic study of the hydrolysis of L-Leucine-2-naphthylamide-hydrochloride, the inhibitor HO3 FA decreases the maximum velocity of the reaction but has no effect on the Michaelis constant. These results indicate that this HS acts as a noncompetitive inhibitor. 相似文献
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A method is described for the specific hydrolysis of amino acids from humic substances by using the proteolytic enzyme “Pronase E”. The amino acids are analyzed by a fluorescence detector after precolumn derivatization and HPLC-separation. The pattern and the concentration of amino acids after the enzymatic hydrolysis are set up for humic substances of different origin. Due to the results the enzymatic hydrolysis is suitable for the characterization of humic substances with a nitrogen content higher than 3%. As shown in a kinetic study of the hydrolysis of a fulvic acid the influence of humic substances on the enzyme activity increases in case of lower nitrogen content. Due to the specificity of the proteolytic enzyme the operationally defined method is limited as shown by a protein of a known amino acid content. The amino acids leucine, valine, tyrosine and histidine are released to the highest extent. The determined total extent for the hydrolysis of Insulin B is 26.34% and for Casein 38.37%. By comparison of the enzymatic hydrolysis with the classic acid hydrolysis the advantages of the biochemical method are the simple experimental handling and the mild reaction conditions. Amino acids which are very unstable like glutamine and asparagine can only be analyzed by the enzymatic hydrolysis. 相似文献
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Niimi S Watanabe MX Kim EY Iwata H Yasunaga G Fujise Y Tanabe S 《Marine pollution bulletin》2005,51(8-12):784-793
This study presents full-length cDNA sequences of CYP1A1 and 1A2, in common minke whale (Balaenoptera acutorostrata) from the North Pacific. Both CYP1A1 and CYP1A2 cDNAs had an open reading frame of 516 amino acid residues, and predicted molecular masses were 58.3 kDa and 58.1 kDa, respectively. The deduced full-length amino acid sequence of CYP1A1 revealed higher identities with those of sheep (86%) and pig (87%), and that of CYP1A2 was most closely related to human (82%) and monkey CYP1A2 (82%) among species from which CYP1A2 has been isolated so far. Differences in certain conserved and functional amino acid residues of CYP1A1 and 1A2 between common minke whale and other mammalian species indicate the possibility of their specific metabolic function. Concentrations of organochlorine compounds (OCs) including PCBs and DDTs analyzed in common minke whale liver showed no significant correlation with hepatic mRNA expression levels of CYP1A1 and CYP1A2, indicating no induction of these enzymes by such OCs. 相似文献
14.
Satoko Niimi Michio X. Watanabe Eun-Young Kim Hisato Iwata Genta Yasunaga Yoshihiro Fujise Shinsuke Tanabe 《Marine pollution bulletin》2005,51(8-12):784
This study presents full-length cDNA sequences of CYP1A1 and 1A2, in common minke whale (Balaenoptera acutorostrata) from the North Pacific. Both CYP1A1 and CYP1A2 cDNAs had an open reading frame of 516 amino acid residues, and predicted molecular masses were 58.3 kDa and 58.1 kDa, respectively. The deduced full-length amino acid sequence of CYP1A1 revealed higher identities with those of sheep (86%) and pig (87%), and that of CYP1A2 was most closely related to human (82%) and monkey CYP1A2 (82%) among species from which CYP1A2 has been isolated so far. Differences in certain conserved and functional amino acid residues of CYP1A1 and 1A2 between common minke whale and other mammalian species indicate the possibility of their specific metabolic function. Concentrations of organochlorine compounds (OCs) including PCBs and DDTs analyzed in common minke whale liver showed no significant correlation with hepatic mRNA expression levels of CYP1A1 and CYP1A2, indicating no induction of these enzymes by such OCs. 相似文献
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Microbial biodegradation of organic substances takes place during drinking water treatment, but also in the distribution net, if the drinking water still contains biodegradable organic substances. This phenomenon is called regrowth. The regrowth potential of a drinking water is high, when for instance ozonation is used as the last step of treatment. It was proved before, that ozonation increases the biodegradability of humic substances, which are the main fraction of organic carbon in drinking water. In this work the objective was to check, if chlorination has a similar effect on humic substances. Using the method developed by Werner of measuring the regrowth potential of a water it could be shown by dilution series with chlorinated and unchlorinated humic substances that the substrate quality of these organics is increased by chlorination. The better substrate quality is seen in the chlorinated solutions, which might contain also low molecular weight organic compounds, but also in the fulvic acid fraction after XAD-enrichment, which removes most of the low molecular weight organic compounds. The chlorination creates in the fulvic acid solutions a shift of molecular size to smaller molecules and higher polar substances, which might be the reasons for the better biodegradability. From these results it can be concluded, that chlorination produces substances, which are more easily biodegradable. But this will not produce regrowth problems as long as there is free chlorine present as a disinfectant. In contrast, when the chlorine demand is very high and no free chlorine is left, this might produce high colony counts in the distribution net. 相似文献
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Humic substances isolated from water, sediment, and soil were characterized by applying elemental analysis, spectroscopic analysis, and gelchromatographic molecular size distribution. In addition, the amounts and pattern of enzymatically released amino acids were determined. Depending on the origin of the humic substances, the percentage of released amino acid nitrogen related to the total nitrogen was in the range of 0.4 to 26.7%. The samples particularly differed in the content of leucine und tyrosine. The total amount of released amino acids was compared with the results obtained from the other characterization methods. This approach indicated that humic substances with a high content of hydrolysable amino acids had high N/C and O/C ratios and low molecular sizes. Beside this, the absorption of these substances in the UV and visible wavelength range was quite low, while the measured ratios of SAK(254)/SAK(436) showed high values. This work leads to the conclusion that the extent of enzymatically releasable amino acids is not only dependant on the nitrogen content of humic substances. Other physical and chemical properties have to be considered for the understanding of the results obtained by the described biochemical characterization method. 相似文献
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The variation in free amino acids concentration was examined in halophytes under salt stress conditions during spring and autumn in an arid environment, Jordan. The experiment was conducted in the southern region of the Jordan valley, using four different halophytes namely: Atriplex halimus, Atriplex nummularia, Tamarix aphylla L., and Portulaca oleracea L. Free amino acid concentrations showed changeable patterns under salinity stress conditions compared to the non‐stress (control) with respect to plant species and seasonal variation. In general, the amino acid pool during the spring experienced increases in A. halimus with increasing salinity; and decreased in A. nummularia, P. oleracea L., and T. aphylla L., respectively. Whereas, during the autumn, the overall amino acids decreased in A. halimus and A. nummularia, and increased in T. aphylla L. and P. oleracea with increasing salinity. The amino acid pool concentrations of A. halimus L. during the autumn was similar to that in spring under stress condition. Similarly, T. aphylla L. and P. oleracea showed higher rates in the autumn. In contrast, A. nummularia L. exhibited a slight increase in amino acid composition in the autumn under stress conditions. The plantation of salt tolerant plants such as halophytes in saline sodic soils showed an effective decline in soil salinity and can be recommended to be used as a bioreclamation method instead of the traditional leaching method, which requires large amount of fresh water. 相似文献
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The Pleistocene vermicular red earth in South China signaling the global climatic change: The molecular fossil record 总被引：11，自引：3，他引：8
The widespread (with a distribution area of 2.2?06 km2) Pleistocene red earth is believed to be one of the most detailed records of the environmental and climatic changes in South China. However, the previous research mainly covers the rough dating, pedo… 相似文献
20.
M. Feuillade J. Feuillade V. Fiala 《Aquatic Sciences - Research Across Boundaries》1990,52(4):345-359
The effect of light intensity on the release of dissolved organic carbon during photosynthesis on NaH14CO3 was investigated using the phytoplanktonic CyanobacteriumOscillatoria rubescens. The released products were fractionated by molecular size and chemical identifications attempted using combined thin-layer electrophoresis and chromatography, and high pressure liquid chromatography.Within the range of irradiances tested (from 6 to 60 µmole m–2 sec–1), though the upper one inhibited photosynthesis ofO. rubescens, light had little effect on the quantity and composition of the excreted products. The released carbon was always lower than 3% of the incorporated carbon, and mainly composed (62 to 86%) by small molecular weight compounds. The prevailing identified compounds were amino acids which represented more than 20% of the excreted carbon. Among organic acids, glycolic acid accounted for less than 2% of the recovered radioactivity. Glucose was the only identified sugar.Abbreviations EOC
excreted organic carbon
- DOC
dissolved organic carbon
- PER
percent extracellular release
- LMW
low molecular weight
- HMW
high molecular weight
- AA
amino acids
- µmoles
m–2 sec–1 = µEinsteins m–2 sec–1 相似文献