69 resultados para BM1958.631
Resumo:
Superoxide dismutase (SOD; EC 1.15.1.1) is an enzyme that protects against oxidative stress from superoxide radicals in living cells. This enzyme had been isolated, purified and partially characterized from muscle tissue of the shrimp Macrobrachium nipponense. The purification was achieved by heat treatment, ammonium sulfate fractionated precipitation and column chromatograph on DEAE-cellulose 32. Some physiological and biochemical characterization of it was tested. The molecular weight of it was about 21.7 kDa, as judged by SDS-polyacrylamide gel electrophoresis. The purified enzyme had an absorption peak of 278 nm in ultraviolet region, and the enzyme remained stable at 25-45 degreesC within 90 min. However, it was rapidly inactivated at higher temperature. Treatment of the enzyme with 1 mM ZnCl2, SDS and 1 mM or 10 mM mercaptoethanol showed some increasing activity. However, the enzyme activity was obviously inhibited by 10 mM CaCl2, CuSO4, ZnCl2 and 1 mM CaCl2 and 10 mM K2Cr2O7. SOD activity did not show significantly variation after incubated with 1 mM CaCl2, EDTA and 10 MM SDS. The enzyme was insensitive to cyanide and contained 1.03 +/- 0.14 atoms of manganese per subunit shown in atomic absorption spectroscopy, which revealed that purified SOD was Mn superoxide dismutase. (C) 2004 Elsevier B.V. All rights reserved.
Resumo:
针对目前栉孔扇贝Chlamys farreri养殖亟待解决的种质、病害、环境和产品质量等日趋严重的问题,从栉孔扇贝本身的防御机制和神经内分泌机制入手,较为系统地研究了环境胁迫,应激激素与血细胞免疫功能之间的相互作用机制;从生态免疫学角度,探讨了栉孔扇贝大规模死亡的原因,为栉孔扇贝病害防治和种质优化提供了一些理论依据。主要研究结果如下: 1.较为系统地综述了贝类生态免疫机制的研究进展。分析了应激激素对贝类细胞免疫活性的抑制作用,以及生态免疫过程中免疫成本的投入与其他生态因子之间的内在联系,分析了病原体与宿主之间的相互作用机制,提出了贝类生态免疫机制研究新见解和新思路。 2.筛选出一种较适用的抗凝剂配方:Glucose 20.8 gL-1,EDTA 20mM, Sodium chloride 20 gL-1,Tris-HCl 0.05M,pH=7.4。 3.模拟研究了栉孔扇贝养殖过程中的主要环境胁迫因子,包括露空胁迫(5°C,17°C和25°C露空最长持续24小时),急性温度胁迫(从17°C分别直接升至23°C和28°C或降至11°C),急性盐度胁迫(从盐度31直接升至盐度35或降至盐度25和20),饥饿胁迫(持续40天)和密度胁迫(分为低、中和高密度),对栉孔扇贝血细胞免疫功能的影响,养殖过程中的露空胁迫对栉孔扇贝的血细胞免疫功能具有抑制作用,从而削弱了扇贝胁迫后恢复的最初24小时中抗击病原体的能力。高温下(25°C)的露空胁迫能够显著地降低扇贝的成活率。急性升温胁迫(从17°C突变至28°C)会严重的破坏栉孔扇贝的内稳态,损伤其血细胞免疫功能,从而增加了扇贝对病原体的易感性。而扇贝对快速的降温胁迫(从17°C突变至11°C)则具有较高的耐受性。盐度20的低盐胁迫能够显著抑制栉孔扇贝的血细胞防御功能,同时低盐有利于许多病原体的繁殖,两方面的协同作用,将大大增加扇贝大规模死亡的几率。饥饿胁迫(40天)能够显著地抑制血细胞的免疫活性,然而在实验室饵料充足的条件下,养殖密度除了对血细胞的吞噬活性有一定的抑制作用外,对血细胞其他的免疫活性影响不明显。 4.揭示了环境胁迫因子,包括露空胁迫(17°C 露空24小时),温度胁迫(从17°C分别直接升至28°C或降至11°C持续7天),低盐胁迫(从盐度31直接降至盐度20持续7天)和饥饿40天胁迫,对栉孔扇贝血细胞超微结构的影响,露空胁迫(17°C 露空24小时),低盐胁迫(盐度20持续7天)和饥饿40天胁迫严重损伤了血细胞的膜系统及各种细胞器的结构。 5.利用酶联免疫法测定了栉孔扇贝血淋巴中应激激素(肾上腺素,去甲肾上腺素和多巴胺)的基础浓度,分别为0.088±0.11, 18.63±1.96 和 2.59±0.46ng/ml。研究了血淋巴中应激激素对环境胁迫(包括露空,急性升温和急性降盐)的响应水平,急性露空,升温和降盐能够显著提高血淋巴中肾上腺素和去甲肾上腺素的浓度,而多巴胺浓度变化却呈现出完全相反的趋势。 6.肾上腺素和去甲肾上腺素体外诱导栉孔扇贝血细胞研究结果表明:浓度为30ng/ml或50ng/ml的去甲肾上腺素能够显著抑制血细胞的吞噬活性,浓度为50ng/ml的去甲肾上腺素能够显著抑制血细胞的活性氧产物,而肾上腺素对血细胞免疫功能的影响则不显著。
Resumo:
Manila clams (Ruditapes philippinarum) and sediments were collected bimonthly during 2007 at five locations in Jiaozhou Bay near Qingdao, China, to determine heavy metal concentrations and to assess the validation of R. philippinarum as a metal biomonitor. Concentrations of heavy metals in clam soft tissues ranged between 0.75 and 3.31, 0.89 and 15.20, 5.70 and 26.03, 52.12 and 110.33, 10.30 and 72.34, 9.64 and 28.60, and 3.15 and 52.75 mu g g (-aEuro parts per thousand 1) dry weight for Cd, Pb, Cu, Zn, Mn, Cr, and Ni, respectively. Most of the highest values occurred at the northeast bay and the lowest values occurred at the western part. Regarding seasonal variation, relatively high tissue metal concentrations were observed during October or December. A similar pattern was also found in habitat sediments. There was a strong correlation between the concentrations of Cd, Pb, Zn, Mn, Cr, and Ni in soft tissues and surrounding sediments. It is indicated that R. philippinarum could be used as a biomonitor for heavy metal contamination in Jiaozhou Bay.
Resumo:
1植物名称唐古特大黄(Rheum tanguticum),又名鸡爪大黄.2材料类别无菌种子苗.3培养条件种子萌发培养基:(1)MS无激素培养基.前期分化培养基:(2)MS+2,4-D 1 mg?L-1(单位下同)+KT 1+ZT 0.5+6-BA 0.5.后期分化培养基:(3)MS+2,4-D 1+KT 2+ZT 0.5+6-BA 1.以上3种培养基均附加CH 300、肌醇200、3%蔗糖、5 g?L-1琼脂粉.生根培养基:(4)MS+NAA 1+3%蔗糖;(5)1/2MS+NAA 1+3%蔗糖;(6)1/2MS+NAA0.5+1.5%蔗糖;(7)1/2MS+NAA 0.5+3%蔗糖;(8)1/2MS+NAA 1+1.5%蔗糖.pH 5.8.培养温度为(25±1)℃,光源为日光灯,光照度为2 000~3 000 lx,光照时间12 h?-1
Resumo:
Increasing attentions have been paid to the subsurface geological storage for CO2 in view of the huge storage capacity of subsurface reservoirs. The basic requirement for subsurface CO2 storage is that the CO2 should be sequestrated as supercritical fluids (physical trapping), which may also interact with ambient reservoir rocks and formation waters, forming new minerals (chemical trapping). In order to the effective, durable and safe storage for CO2, enough storage space and stable sealing caprock with strong sealing capacity are necessitated, in an appropriate geological framework. Up till now, hydrocarbon reservoirs are to the most valid and appropriate CO2 storage container, which is well proven as the favorable compartment with huge storage capacity and sealing condition. The thesis focuses on two principal issues related to the storage and sealing capacity of storage compartment for the Qingshankou and Yaojia formations in the Daqingzijing block, Southern Songliao Basin, which was selected as the pilot well site for CO2-EOR storage. In the operation area, three facies, including deltaic plain, deltaic front and subdeep-deep lake facies associations, are recognized, in which 11 subfacies such as subaqueous distributary channel, river- mouth bar, interdistributary bay, sheet sandbody, crevasse splay and overflooding plain are further identified. These subfacies are the basic genetic units in the reservoir and sealing rocks. These facies further comprise the retrogradational and progradational depositional cycles, which were formed base- level rise and fall, respectively. During the regressive or lake lowstand stage, various sands including some turbidites and fans occurred mostly at the bottom of the hinged slope. During the progradation stage, these sands became smaller in size and episodically stepped backwards upon the slope, with greatly expanded and deeped lake. However, most of Cretaceous strata in the study area, localized in the basin centre under this stage, are mainly composed of grey or grizzly siltstones and grey or dark grey mudstones intercalated with minor fine sandstones and purple mudstones. On the base of borehole and core data, these siltstones are widespread, thin from 10 to 50 m thick, good grain sorting, and have relative mature sedimentary structures with graded bedding and cross- lamination or crossbeds such as ripples, which reflect strong hydrodynamic causes. Due to late diagenesis, pores are not widespread in the reservoirs, especially the first member of Qingshankou formation. There are two types of pores: primary pore and secondary cores. The primary pores include intergranular pores and micropores, and the secondary pores include emposieus and fracture pores. Throat channels related to pores is also small and the radius of throat in the first, second and third member of Qingshankou formation is only 0.757 μm, 0.802 μm and 0.631 μm respectively. In addition, based on analyzing the probability plot according to frequency of occurrence of porosity and permeability, they appear single- peaked distribution, which reflects strong hetero- geneity. All these facts indicate that the conditions of physical property of reservoirs are not better. One reason may be provided to interpret this question is that physical property of reservoirs in the study area is strong controlled by the depositional microfacies. From the statistics, the average porosity and permeability of microfacies such as subaqueous distributary channel, channel mouth bar, turbidites, is more than 9 percent and 1md respectively. On the contrary, the average porosity and permeability of microfacies including sand sheet, flagstone and crevasse splay are less than 9 percent and 0.2md respectively. Basically, different hydrodynamic environment under different microfacies can decide different physical property. According to the reservoir models of the first member of Qingshankou formation in the No. well Hei47 block, the character of sedimentary according to the facies models is accord to regional disposition evolution. Meantime, the parameter models of physical property of reservoir indicate that low porosity and low permeability reservoirs widespread widely in the study area, but the sand reservoirs located in the channels are better than other places and they are the main sand reservoirs. The distribution and sealing ability of fault- fractures and caprock are the key aspects to evaluate the stable conditions of compartments to store CO2 in the study area. Based on the core observation, the fractures widespread in the study area, especially around the wells, and most of them are located in the first and second member of Qingshankou formation, almost very few in the third member of Qingshankou formation and Yaojia formation instead. In addition, analyzing the sealing ability of eleven faults in the three-dimensional area in the study area demonstrates that most of faults have strong sealing ability, especially in the No. well Hei56 and Qing90-27. To some extent, the sealing ability of faults in the No. well Hei49, Qing4-6 and Qing84-29 are worse than others. Besides, the deposition environment of most of formations in the study area belongs to moderately deep and deep lake facies, which undoubtedly take advantage to caprocks composed of mudstones widespread and large scale under this deposition environment. In the study area, these mudstones distribute widely in the third member of Qingshankou formation, Yaojia and Nenjiang formation. The effective thickness of mudstone is nearly ~550m on an average with few or simple faults and fractures. In addition, there are many reservoir beds with widely- developed insulated interbeds consist of mudstones or silty mudstone, which can be the valid barrier to CO2 upper movement or leakage through diffusion, dispersion and convection. Above all, the closed thick mud caprock with underdeveloped fractures and reservoir beds can be taken regard as the favorable caprocks to provide stable conditions to avoid CO2 leakage.
Resumo:
CH4-CO2-O-2 reforming to syngas in a never Ba0.5Sr0.5Co0.8Fe0.2O3.delta oxygen-permeable membrane reactor using LiLaNiO/gamma-Al2O3 as catalyst was successfully reported. Excellent reaction performance was achieved with around 92% methane conversion efficiency, 95% CO2 conversion rate, and nearly 8.5mL/min.cm(2) oxygen permeation flux. In contrast to the oxygen permeation model with the presence of large concentration of CO2 (under such condition the oxygen permeation flux deteriorates with time), the oxygen permeation flux is really stable under the CH4CO2-O-2 reforming condition.