低氧胁迫对珍珠龙胆石斑鱼氧化应激及能量代谢的影响

【目的】探究保活运输中低氧胁迫对珍珠龙胆石斑鱼(Epinephelus fuscoguttatus♀×Epinephelus lanceolatus♂)氧化应激的影响。【方法】诱导体质量为(498.2±27.3)g的杂交石斑鱼进入休眠状态,并放置在溶解氧为(1.74±0.21)mg·L^?1的低氧环境下,低氧胁迫0、6、12、24、48、72 h后,取样测定血清应激指标,肌肉、肝脏、鳃组织氧化应激指标及肌肉、肝脏能量利用指标。【结果】低氧胁迫过程中,杂交石斑鱼血糖含量在胁迫6 h时最大,72 h时恢复胁迫前水平;皮质醇含量在胁迫过程均显著高于胁迫前;肌肉超氧化物歧化酶(SOD)活性随胁迫时间的增加而上升,肝脏、鳃SOD活性先上升后下降;肌肉、肝脏过氧化氢酶(CAT)活性呈先升后降的趋势,鳃CAT活性在胁迫12、72 h显著低于胁迫前;肌肉、肝脏丙二醛(MDA)含量在胁迫过程中均增加,鳃MDA含量先降后升;肌肉谷胱甘肽还原酶(GSH)含量在胁迫12 h达到最大值,肝脏GSH含量呈先上升后下降的趋势,鳃中GSH含量在12 h时显著高于胁迫前,之后逐渐升高;总抗氧化能力(T-AOC)在肌肉、肝脏、鳃中均呈上升的趋势;肌肉和肝脏中糖原的含量显著减少,肌肉乳酸脱氢酶(LDH)活性显著增加,肝脏LDH先降后升。显著性水平均为0.05。【结论】低氧胁迫会刺激珍珠龙胆石斑鱼产生应激反应,影响体内正常的氧化应激系统,并对不同组织造成不同程度的氧化损伤。     

The global metabolic transition: Regional patterns and trends of global material flows, 1950–2010

Since the World War II, many economies have transitioned from an agrarian, biomass-based to an industrial, minerals-based metabolic regime. Since 1950, world population grew by factor 2.7 and global material consumption by factor 3.7–71 Gigatonnes per year in 2010. The expansion of the resource base required by human societies is associated with growing pressure on the environment and infringement on the habitats of other species. In order to achieve a sustainability transition, we require a better understanding of the currently ongoing metabolic transition and its potential inertia. In this article, we present a long-term global material flow dataset covering material extraction, trade, and consumption of 177 individual countries between 1950 and 2010. We trace patterns and trends in material flows for six major geographic and economic country groupings and world regions (Western Industrial, the (Former) Soviet Union and its allies, Asia, the Middle East and Northern Africa, Latin America and the Caribbean, and Sub-Saharan Africa) as well as their contribution to the emergence of a global metabolic profile during a period of rapid industrialization and globalization. Global average material use increased from 5.0 to 10.3 tons per capita and year (t/cap/a) between 1950 and 2010. Regional metabolic rates range from 4.5 t/cap/a in Sub-Saharan Africa to 14.8 t/cap/a in the Western Industrial grouping. While we can observe a stabilization of the industrial metabolic profile composed of relatively equal shares of biomass, fossil energy carriers, and construction minerals, we note differences in the degree to which other regions are gravitating toward a similar form of material use. Since 2000, Asia has overtaken the Western Industrial grouping in terms of its share in global resource use although not in terms of its per capita material consumption. We find that at a sub-global level, the roles of the world regions have changed. There are, however, no signs yet that this will lead to stabilization or even a reduction of global resource use.     

糖原含量与糖原磷酸化酶基因(GPH)和己糖激酶基因(HK)的表达在福建牡蛎生殖周期中的相关性分析

Glycogen, a polymer of glucose, is an important means of storing energy. It is degraded by glycogen phosphorylase (GPH) and hexokinase (HK), glycogen phosphorylase, and hexokinase cDNAs (Ca-GPH andCa-H...     

脂肪营养对封闭循环水养殖道氏虹鳟生长、相关代谢酶及基因表达的影响

为探讨饲料脂肪营养对封闭循环水养殖道氏虹鳟(Oncorhynchus mykiss)生长、脂肪代谢及相关酶基因表达的影响,作者采用单因素设计,即4个脂肪水平——12%、15%、18%、21%(以Ⅰ、Ⅱ、Ⅲ、Ⅳ组表示),共4个处理组,每处理3重复,每重复25尾鱼。试验鱼为初始体质量(333.25±20.71)g的道氏虹鳟幼鱼,试验期77 d。结果表明,与后3组相比,Ⅰ组试验鱼增质量率显著提高17.20%~33.17%,Ⅰ和Ⅱ组饲料系数显著低于Ⅲ和Ⅳ组6.20%~20.56%(P0.05);脂肪合成酶类FAS活力随饲料脂肪水平升高而降低,脂肪分解酶类LPL、HL及L-CPTⅠ活力变化特征与之相反(P0.05)。其中,Ⅰ组FAS活力显著高于Ⅲ、Ⅳ组7.5%、8.7%;L-CPTⅠ活力显著低于后3组13.08%~16.35%;Ⅳ组LPL活力显著或极显著高于前3组18.8%~44.7%(P0.05或P0.01);I组肝脏FAS的mRNA表达量比后3组显著高48.29%~55.15%(P0.05);LPL呈相反特征,Ⅳ组显著高于前3组36.72%~113.59%(P0.05或P0.01);Ⅰ组肌肉FAS mRNA表达量显著高于Ⅳ组66.82%(P0.05);LPL表达丰度随脂肪水平升高先下降后显著上升(P0.05)。该结果特征与肝脏中该两种酶活力变化具有同步性。研究发现,随饲料脂肪水平变化,肌肉FAS mRNA表达量变化比肝脏更明显且规律性更强,而肝脏LPL mRNA表达量变化较肌肉更明显。本试验初步确定,在封闭循环水养殖模式下,330 g左右道氏虹鳟饲料蛋白水平在45%时,脂肪水平以不超过12%为宜。     

酵母海藻糖的代谢与调控研究进展

海藻糖(Trehalose)是化学性质稳定的非还原性二糖,由2个吡喃葡萄糖分子通过α-1,1-糖苷键连接而成,海藻糖独特的物理特性使其在细胞中可起到稳定生物大分子的作用,因而在化妆品、医药和食品等工业领域中有极好的应用前景。在酵母菌中海藻糖可作为储藏碳水化合物和细胞应激反应保护剂。当环境条件变化时细胞内海藻糖含量会发生显著变化,而海藻糖的积累已被证实在不同胁迫应答中起关键作用,海藻糖代谢途径仅有几个代谢物组成,却受到复杂的代谢调控机制的控制。此外,海藻糖代谢在酵母菌的糖代谢中还起了非常重要的调控作用。     

不同盐碱环境中宁夏枸杞叶生理特征和RAPD分析

调查了生长在不同盐碱地宁夏枸杞(Lycium barbarum L.)的生理特征。研究发现,次生盐碱地对枸杞的影响要大于原生盐碱地,光合色素含量、脯氨酸含量、蛋白质和核酸均表现为生长在次生盐碱地的枸杞体内含量高,但在幼株和成年植株体内的变化各不相同。可溶性蛋白凝胶电泳显示,对不同年龄的植株在同样的生境中谱带条数和着色深浅基本一样,但不同生境中有两条谱带的着色深浅有明显的不同。分析表明,光合色素含量、脯氨酸含量和蛋白质代谢的这种变化可能是植物的一种适应性反应,它有利于植物抵抗盐胁迫的伤害。RAPD分析表明宁夏枸杞在生长发育过程中,为了适应环境,在代谢发生了变化后,其遗传物质DNA也发生了一定的变异。     

Remote sensing-based geostatistical hot spot analysis of Urban Heat Islands in Dhaka,Bangladesh

Urban Heat Island (UHI) refers to a phenomenon whereby urban areas experience higher temperatures compared to the surrounding areas. Remote sensing-based Land Surface Temperature (LST) measurements can be utilized to measure UHI. This study emphasized on geostatistical remote sensing-based hot spot analysis ($G_i^{*}$) of UHI in Dhaka, Bangladesh as a way of examining the influences of Land Use Land Cover (LULC) on UHI from 1991 to 2015. Landsat 5 and 7 satellite-based remote sensing indices were used to explore LULC, UHI and environmental footprints during the study period. The Urban Compactness Ratio (C_oR) was used to calculate the urban form and augmented characteristics. The Surface Urban Heat Island (SUHI) intensity (ΔT) was also used to explore the effects of UHI on the surrounding marginal area. Based on our investigations into LULC, we discovered that around 71.34 per cent of water bodies and 71.82 percent of vegetation cover decreased from 1991 to 2015 in Dhaka city. Contrastingly, according to C_oR readings, 174.13 km² of urban areas expanded by 249.77 per cent. Our hot spot analysis also revealed that there was a 93.73 per cent increase in hot concentration zones. Furthermore, the average temperature of the study area had increased by 3.26°C. We hope that the methods and results of this study can contribute to further research on urban climate.