南方鲇卵母细胞和滤泡细胞中线粒体的类型与变化

南方鲇卵母细胞和滤泡细胞发育过程中共出现6种形态的线粒体.椭圆形板状嵴线粒体在卵母细胞和滤泡细胞中同时存在,细条状线粒体、球形线粒体主要存在于卵母细胞中,长条形板状嵴线粒体、锯齿状线粒体和巨型线粒体主要存在于滤泡细胞中,尤以颗粒细胞中丰富.巨型线粒体是一种即将退化的线粒体,其衰退过程可以分为前期、衰退早期、衰退中期和晚期.线粒体在卵子发生过程中起着十分重要的作用,尤其与卵黄的发生和形成关系密切.     

南方鲇卵母细胞和滤泡细胞中线粒体的类型与变化

南方鲇卵母细胞和滤泡细胞发育过程中共出现6种形态的线粒体．椭圆形板状嵴线粒俸在卵母细胞和滤泡细胞中同时存在,细条状线粒体、球形线粒体主要存在于卵母细胞中,长条形板状嵴线粒体、锯齿状线粒体和巨型线粒体主要存在于滤泡细胞中,尤以颗粒细胞中丰富．巨型线粒体是一种即将退化的线粒体,其衰退过程可以分为前期、衰退早期、衰退中期和晚期．线粒体在卵子发生过程中起着十分重要的作用,尤其与卵黄的发生和形成关系密切．     

线粒体损伤对山羊-绵羊异种核移植胚早期发育的影响

【目的】研究线粒体损伤对核移植胚早期发育的影响。【方法】用经光敏化染料罗丹明-123损伤的山羊胎儿成纤维细胞和绵羊卵母细胞,构建山羊-绵羊异种体细胞核移植胚,于38.5℃、相对湿度100%、体积分数5%CO2条件下培养,统计其2-细胞期、8-细胞期和囊胚期的发育率。【结果】山羊核供体线粒体损伤并不影响囊胚期前核移植胚的发育率(P0.05);绵羊卵母细胞线粒体损伤,使核移植胚2-细胞期的发育率下降(P0.05),但不影响8-细胞期和囊胚期的发育率(P0.05);核供体和卵母细胞线粒体都损伤的核移植胚发育率的变化规律与卵胞质受体线粒体损伤的核移植胚一致。【结论】在异种核移植胚的早期发育中,核供体线粒体损伤不影响核移植胚的发育,但卵母细胞受体线粒体损伤明显影响核移植胚的发育率。     

Ca2+诱导损伤线粒体超微结构的原子力显微镜研究

采用Ca²⁺急性诱导构建线粒体损伤模型,分别通过透射电子显微镜和原子力显微镜观测线粒体内部结构和表面形貌的变化,用以探究线粒体损伤过程中结构变化的规律性。结果显示,线粒体在Ca²⁺诱导下的损伤过程依照内部结构的变化规律可分为前后2个阶段：前期以嵴有序结构的破坏为特征,线粒体内部特异性结构逐步被破坏,无明显肿胀趋势;后期以线粒体嵴间隙膨胀、嵴囊泡化为特征,线粒体迅速膨胀并向球形变化,线粒体的最终裂解应存在临界条件,决定于线粒体外膜的张力特性。     

葛根提取物对肝线粒体损伤的保护作用(英文)

[目的]研究葛根提取物对肝线粒体损伤的保护作用。[方法]用Vc-Fe2+诱导线粒体损伤,测定葛根提取物对ATP酶的活性、线粒体肿胀度和蛋白质羰基含量的影响;用H2O2-Fe2+诱导线粒体脂质过氧化,测定葛根提取物对丙二醛含量的影响;用NBT法测定葛根提取物抑制线粒体产生超氧阴离子的作用。[结果]葛根提取物能显著地抑制线粒体的氧化损伤,并能防止线粒体肿胀和ATP酶活力下降,降低蛋白质羰基化水平,以及具有有效清除线粒体产生的超氧阴离子自由基的作用。[结论]该试验为葛根药理作用的研究提供了理论依据。     

模拟酸雨对青菜叶片若干显微结构和生理变化影响的初步研究

本文描述了模拟酸雨(pH2.0、3.0、3.5、4.0、5.6)处理的田间种植青菜叶片若干生理特性如叶绿素含量、细胞膜透性、叶片活力等的变化并使用扫描电子显微镜和透析电子显微镜的方法观察了叶片的微观损伤、气孔开度及叶绿体、线粒体等细胞器。结果表明:暴露于模拟酸雨的青菜叶片的微观损伤出现在宏观损伤之前,而所测定的若干特性均有某种程度的变化。气孔开度受到了降雨酸度的影响,细胞内层的叶绿体、线粒体等结构发生了一些变化。     

L-肉碱对NEFA致肝细胞氧化应激损伤的保护作用

奶牛酮病时引起非酯化脂肪酸(NEFA)增加,造成肝细胞线粒体损伤,引发氧化应激反应.L-肉碱作为一种抗氧化剂,是否对NEFA导致的肝脏氧化应激损伤具有保护作用仍然未知.为探讨L-肉碱对NEFA致细胞氧化应激损伤的保护效果,通过建立NEFA诱导小鼠肝细胞AML12氧化应激损伤模型,运用试剂盒检测氧化应激相关指标和线粒体分布及线粒体膜电位.结果表明,与对照组相比,NEFA极显著升高AML12细胞丙二醛和活性氧水平(P<0.01),降低总超氧化物歧化酶、过氧化氢酶、谷胱甘肽过氧化物酶活性(P<0.01),导致线粒体异常分布(P<0.01),降低线粒体膜电位(P<0.01);但在NEFA中添加L-肉碱处理后,与NEFA组相比,极显著降低丙二醛和活性氧水平(P<0.01),升高总超氧化物歧化酶、过氧化氢酶、谷胱甘肽过氧化物酶活性(P<0.01),极显著降低线粒体异常分布率(P<0.01),升高线粒体膜电位(P<0.05).试验结果表明,L-肉碱可减轻NEFA引起的小鼠肝细胞氧化应激损伤,为奶牛酮病治疗提供一种新思路.     

一氧化氮对低温贮藏桃果实线粒体氧化损伤的影响

【目的】分析一氧化氮(NO)对冷藏过程中桃果实线粒体氧化损伤的影响。【方法】分别用15 μmol/L NO、5 μmol/L c-PTIO (NO清除剂)、对照(去离子水)浸泡30 min处理桃果实。测定0℃下桃果实的线粒体完整性、活性氧含量、抗氧化酶的活性及相关品质指标。【结果】在桃果实低温冷藏过程中,NO处理可以维持桃果实硬度、色差L值及可溶性固形物含量,降低线粒体耗氧量和减少活性氧的积累,调节线粒体呼吸控制率(RCR)、线粒体膜电势,线粒体细胞色素C含量以及线粒体抗氧化酶活性。【结论】NO通过减少线粒体氧化损伤,维持线粒体的完整性,延长桃果实的贮藏期。     

醋粉的体外抗氧化活性研究

通过测定醋粉的·OH(羟自由基)和DPPH·(二苯基苦味酰基苯肼自由基)的清除率、总抗氧化能力等指标,研究醋粉的体外抗氧化活性;通过将离体的小鼠肝线粒体和红细胞作为氧化损伤模型,研究醋粉对小鼠红细胞和肝线粒体氧化应激损伤的保护作用。结果表明,醋粉具有较强的清除·OH和DPPH·的能力,其还原力和总抗氧化能力也很强;醋粉可以明显抑制红细胞的氧化溶血和丙二醛的产生,对肝线粒体的氧化损伤也具有很好的保护作用,说明醋粉的抗氧化活性较强,是天然抗氧化剂的良好来源。     

电离辐射与线粒体DNA的变异

线粒体DNA(mitchondrial DNA,mtDNA)是裸露的双链环状DNA分子结构．缺少组蛋白外衣的保护,复制快速．缺乏校读功能以及缺乏有效的DNA修复系统,极易发生突变。而电离辐射作为一种致DNA损伤的因素．现已发现它可以诱导线粒体DNA的突变,其中包括4977bp的缺失、点突变、插入突变等。在凋亡调节诸多通路中,线粒体在电离辐射诱导的细胞凋亡通路中起中心调控作用。各种死亡信号通过Bcl-2家族蛋白或直接诱导线粒体膜的通透性的改变、细胞色素C释放和caspases激活,最终引起细胞凋亡。线粒体膜的通透性改变的机制．目前还未完全明了。本文就电离辐射与线粒体DNA的变异以及线粒体DNA变异与凋亡的关系作一简要综述。     

Gulf stream cold-core rings: their physics, chemistry, and biology

Cyclonic Gulf Stream rings are energetic eddies in the warm Sargasso Sea consisting of a ring of Gulf Stream water surrounding a core of cold Slope Water. Initially a ring core has the characteristics of the Slope Water; it is rich in plants, animals, and nutrients. As a ring decays the Slope Water properties of its core are gradually replaced by those of the Sargasso Sea, where standing crops of plants, animals, and nutrients generally are low. Although the decay rate suggests a rather long lifetime (2 to 4 years), the usual death of a ring comes when it rejoins the Gulf Stream after 6 to 12 months.     

Molecular pathways of neurodegeneration in Parkinson's disease

Parkinson's disease (PD) is a complex disorder with many different causes, yet they may intersect in common pathways, raising the possibility that neuroprotective agents may have broad applicability in the treatment of PD. Current evidence suggests that mitochondrial complex I inhibition may be the central cause of sporadic PD and that derangements in complex I cause alpha-synuclein aggregation, which contributes to the demise of dopamine neurons. Accumulation and aggregation of alpha-synuclein may further contribute to the death of dopamine neurons through impairments in protein handling and detoxification. Dysfunction of parkin (a ubiquitin E3 ligase) and DJ-1 could contribute to these deficits. Strategies aimed at restoring complex I activity, reducing oxidative stress and alpha-synuclein aggregation, and enhancing protein degradation may hold particular promise as powerful neuroprotective agents in the treatment of PD.     

水稻田使用秸秆腐熟剂试验效果分析

选用3种秸秆腐熟剂进行田间试验,研究秸秆腐熟剂对秸秆腐熟、土壤养分及水稻产量性状的影响。结果表明,秸秆腐熟剂加速了秸秆腐烂,增加了土壤养分含量,提高了水稻产量。     

福建酸竹笋防霉防虫保鲜技术研究

竹笋特别是富有营养的福建酸竹笋,挖出后容易进一步老化、腐烂,而且容易产生虫害,严重影响鲜笋保鲜加工乃至直接上市,用其制作价格较高的净菜上市尤其困难;本试验用杀青、低盐、高能γ射线辐照、冷藏对其进行防霉防虫保鲜试验发现：经杀青、低盐、辐照综合处理的竹笋,可在３～５℃下冷藏４４ｄ不霉变、不长虫,比鲜笋直接冷藏延长保鲜期３０ｄ;鲜笋不宜直接辐射处理;为福建酸竹笋的保藏、加工和远销提供了科学依据．     

红景天苷对神经退行性疾病作用的研究进展

红景天苷（Salidroside,Sal）是景天科植物红景天的主要活性成分之一。研究显示,Sal在帕金森病（Parkinson''s disease,PD）、阿尔茨海默病（Alzheimer''s disease,AD）和亨丁顿舞蹈症（Huntington''s disease,HD）中的氧化和抗氧化系统起到双向调节作用。此外,Sal在PD和AD中可通过维持线粒体功能、减少ROS生成和增加抗凋亡蛋白和凋亡蛋白的比例以抑制细胞凋亡,进而促进神经元存活。但其在神经退行性疾病中的具体机制,如Sal通过哪种机制调控线粒体形态和功能的稳定以及Sal在疾病模型中的体内代谢分布改变等,仍有待进一步深入研究和临床验证。本文仅就Sal对神经退行性疾病的作用研究进展进行综述,为进一步研究提供参考。     

海藻酸复混肥对夏玉米产量及养分吸收利用的影响

为明确夏玉米施用海藻酸复混肥的增产效果,通过田间试验,以浚单29为材料,利用数理统计、对比分析方法,研究了海藻酸包膜BB肥、常规BB肥、海藻酸包膜复合肥、常规复合肥4种肥料对鹤壁和许昌两地夏玉米产量、地上部生物量、养分积累量、SPAD值等的影响。结果表明,鹤壁和许昌夏玉米施肥分别显著增产8.80%~15.41%和21.21%~35.85%,海藻酸包膜BB肥较等养分常规BB肥分别增产5.70%和5.22%;海藻酸包膜复合肥较常规复合肥产量显著增加5.98%和13.37%,施海藻酸复混肥提高了夏玉米叶绿素含量,促使氮磷钾养分积累量分别增加3.76%~17.03%、6.29%~27.14%和3.70%~9.33%,协同提高了千粒重与穗粒数,且减量施肥20%产量差异不显著。综合考虑产量、肥料投入与环境压力,豫北和豫中地区夏玉米推荐施用海藻酸复合肥600 kg/hm2。     

早稻秸秆还田添加腐熟剂对晚稻产量及土壤养分的影响

[目的]研究秸秆还田添加腐熟剂对晚稻生长发育及土壤养分含量的影响。[方法]以协优46为供试晚稻品种,以秸秆不还田为对照,在秸秆还田的情况下添加家农、金葵子、鱼米香秸秆腐熟剂,研究秸秆腐熟剂对晚稻产量及土壤养分的影响。[结果]与秸秆不还田相比,秸秆还田可使晚稻穗粒数、实粒数、结实率及千粒重分别提高1.1~7.5粒、3.0~6.6粒、1.0个百分点~5.2个百分点、0.2~0.9 g,明显提高晚稻产量,平均增产357.5 kg/hm~2,增幅为5.8%;可使土壤容重减少0.03~0.06 g/cm3,pH降低0.20,土壤有机质、全氮、速效钾、阳离子交换量(CEC)分别增加0.15~0.26 g/kg、0.04~0.11 g/kg、5.00~10.00 mg/kg、0.18~1.04 cmol/kg;添加秸秆腐熟剂对早稻秸秆腐解比自然情况下的腐解时间缩短15 d。[结论]秸秆还田添加腐熟剂可提高晚稻产量和土壤养分含量,3种腐熟剂增产和改善土壤养分的效果从好到差依次为金葵子、家农、鱼米香。     

Impacts of silicon on biogeochemical cycles of carbon and nutrients in croplands

Crop harvesting and residue removal from croplands often result in imbalanced biogeochemical cycles of carbon and nutrients in croplands, putting forward an austere challenge to sustainable agricultural production. As a beneficial element, silicon (Si) has multiple eco-physiological functions, which could help crops to acclimatize their unfavorable habitats. Although many studies have reported that the application of Si can alleviate multiple abiotic and biotic stresses and increase biomass accumulation, the effects of Si on carbon immobilization and nutrients uptake into plants in croplands have not yet been explored. This review focused on Si-associated regulation of plant carbon accumulation, lignin biosynthesis, and nutrients uptake, which are important for biogeochemical cycles of carbon and nutrients in croplands. The tradeoff analysis indicates that the supply of bioavailable Si can enhance plant net photosynthetic rate and biomass carbon production (especially root biomass input to soil organic carbon pool), but reduce shoot lignin biosynthesis. Besides, the application of Si could improve uptake of most nutrients under deficient conditions, but restricts excess uptake when they are supplied in surplus amounts. Nevertheless, Si application to crops may enhance the uptake of nitrogen and iron when they are supplied in deficient to luxurious amounts, while potassium uptake enhanced by Si application is often involved in alleviating salt stress and inhibiting excess sodium uptake in plants. More importantly, the amount of Si accumulated in plant positively correlates with nutrients release during the decay of crop biomass, but negatively correlates with straw decomposability due to the reduced lignin synthesis. The Si-mediated plant growth and litter decomposition collectively suggest that Si cycling in croplands plays important roles in biogeochemical cycles of carbon and nutrients. Hence, scientific Si management in croplands will be helpful for maintaining sustainable development of agriculture.     

Diffusible signals, not autonomous mechanisms, determine the main proximodistal limb subdivision

Vertebrate limbs develop three main proximodistal (PD) segments (upper arm, forearm, and hand) in a proximal-to-distal sequence. Despite extensive research into limb development, whether PD specification occurs through nonautonomous or autonomous mechanisms is not resolved. Heterotopic transplantation of intact and recombinant chicken limb buds identifies signals in the embryo trunk that proximalize distal limb cells to generate a complete PD axis. In these transplants, retinoic acid induces proximalization, which is counteracted by fibroblast growth factors from the distal limb bud; these related actions suggest that the first limb-bud PD regionalization results from the balance between proximal and distal signals. The plasticity of limb progenitor cell identity in response to diffusible signals provides a unifying view of PD patterning during vertebrate limb development and regeneration.     

南疆冬枣的营养及挥发性成分分析

[目的]客观揭示南疆地区鲜食冬枣的品质。[方法]采用HPLC、GC-MS等方法对冬枣的营养及挥发性成分进行分析。[结果]冬枣含有VC含量（161.859 3±13.509 2）mg/100 g鲜枣,总糖（55.384 5±2.539 2）%,总酸（1.384 7±0.115 5）%,粗脂肪（4.275±0.191）%,cAMP（0.228±0.020）mg/g,检出15种氨基酸（包含6种必需氨基酸）。挥发性成分中鉴定出40种化合物,其主要成分为酯类、烷烃类、醇类和胺类。[结论]冬枣是一种有较高营养价值的水果。