Mesh-like vascular changes in copper deficiency-induced rat cardiomyopathy

The pathological effects of copper deficiency (COD) are well known. However, the pathogenesis of cardiomyopathy resulting from COD remains unclear. In this study, aimed to elucidate the pathogenesis of COD-induced cardiomyopathy by examining the morphology of the cardiovascular system in copper-deficient rats using histopathology, immunohistochemistry, and scanning and transmission electron microscopy. Changes detected in the myocardium and interstitium were consistent with those reported for COD. Morphological changes included mesh-like changes in the capillary endothelial cells that appear to be a novel finding in COD-induced cardiomyopathy. These changes are hypothesized to result from abnormal vascular remodeling following damage to the basement membrane and due to the mechanical effects of myocardial contractions. Although cardiomyopathy may be associated with microcirculatory disorders arising from these lesions, further investigations are necessary to demonstrate a causal relationship between the pathogenesis of cardiomyopathy and the contribution of these lesions to disease progression.     

野生老芒麦种质资源鉴定与基部叶鞘绒毛变异分析

为更好地利用老芒麦(Elymus sibiricus L.)野生资源,本研究从我国青藏高原、西北、华北、东北地区以及国外部分地区共采集了1 723份野生披碱草属种质资源,通过表型特征观测和流式细胞仪检测,共鉴定出了990份野生老芒麦种质,246份垂穗披碱草种质,并测得老芒麦的DNA含量在5.86～7.30 Gb之间,平均DNA含量为6.66 Gb;垂穗披碱草材料的DNA含量在9.50～10.36 Gb之间,平均DNA含量为9.97 Gb。研究结果显示,在西北、华北以及东北地区的部分野生老芒麦材料在苗期基部叶鞘出现了绒毛,分析发现该表型出现的概率与经度和纬度呈极显著正相关关系(P<0.01),与海拔、年年均气温以及年平均降雨量呈极显著负相关关系(P<0.01)。表明老芒麦苗期基部叶鞘绒毛的有无与环境因子之间存在着必然的联系,可能是老芒麦种质应对不同环境类型的适应性机制之一。本研究为老芒麦的形态鉴定提供了新的依据,为老芒麦种质资源挖掘和育种应用提供了材料基础。     

Quinone Binding Sites of Membrane Proteins as Targets for Inhibitors

Quinones are a central component of most photosynthetic and respiratory electron transfer chains. The proteins that reduce and oxidise these quinones have quinone binding sites—Q sites—that are good targets for pesticides. This paper reviews the diversity of these sites, their possible structure, and the types of compounds that act upon them.     

不同增氧滴灌方式对蔬菜生长生理指标的影响

为了研究不同增氧方式对盆栽小白菜生长生理指标的影响,以小白菜为供试作物,采用盆栽地下滴灌的方式,以普通地下滴灌作为对照(CK),设置循环曝气(MAI)、双氧水(H₂O₂)、纯氧扩散器曝气(OC)及射流振荡器曝气(FO)4个增氧灌溉处理.结果表明,增氧地下滴灌显著提高了土壤呼吸速率,处理MAI,OC和FO较对照处理分别增大了65.87%,66.79%和111.62%.增氧地下滴灌促进了小白菜的根系生长、光合作用、蒸腾速率和气孔导度,进而提高了小白菜的物质量积累和产量.与对照相比,处理MAI的地下部鲜质量增大了42.03%,地下部干质量增大了79.85%;处理MAI,H₂O₂,OC和FO的光合速率分别增大了868.62%,794.14%,778.67%和650.19%;处理MAI,H₂O₂和OC的气孔导度较CK增大了157.14%,128.57%和85.71%,蒸腾速率增大了55.61%,32.38%和19.58%;处理MAI和H₂O₂的产量分别增大了56.36%和38.72%.综上,增氧地下滴灌可增强小白菜根区的土壤呼吸作用,改善光合作用、蒸腾速率和气孔导度,提高了产量及水分利用效率.其中,循环曝气处理的改善效果最为显著.     

Heat shock protein 70 expression in different tissues of Cirrhinus mrigala (Ham.) following heat stress

Members of heat shock protein 70 (HSP70) are highly conserved proteins of about 70 kDa and play important roles in protein folding. Levels of these proteins increase when cells are under stress. Environmental temperature influences both the basal and induced levels of HSPs. However, studies on HSPs in fishes from a tropical country such as India are lacking. In the present study, Indian major carp (IMC) Cirrhinus mrigala (Ham.) acclimatized at 25±2°C had high levels of HSP70, viz., 1.2–1.3 ng μg^?1 total protein in kidney and gill and 4.2–5.3 ng μg^?1 total protein in liver and brain tissues, indicating the presence of biochemically significant levels of stress. However, maintenance of acclimatized fish at 17°C for up to 48 h did not lead to a significant decrease in stress protein levels. A heat shock at 37°C for up to 48 h resulted in only two to threefold increase in HSP70 levels in these organs. Although the increase in HSP70 levels was apparent from the first hour of heat stress in all these tissues, the increase was significant from the second hour in the brain, the sixth hour in liver and kidney and the 20th hour in the gills.     

水涨龙眼结果母枝内源激素含量变化对花芽分化的影响

应用酶联免疫法（ＥＬＩＳＡ）,测定了涨龙眼花芽分化期间结果母枝内源激素ｉＰＡｓ、ＧＡｓ、ＡＢＡ及ＩＡＡ的含量变化。结果表明,生理分化期花芽内源激素含量：ＡＢＡ〉ｉＰＡｓ〉ＩＡＡ〉ＧＡｓ;形成分化期为：ＡＢＡ〉ＩＡＡ〉ｉＰＡｓ〉ＧＡｓ。生理分化期主形态分化期叶芽内源激素含量均为：ＡＢＡ〉ｉＰＡｓ〉ＧＡｓ〉ＩＡＡ。生理分化期：与叶芽相比,花芽的ｉＰＳｓ、ＧＡｓ和ＩＡＡ含量高,ＡＢＡ含量低。形态分化期：     

覆膜抑制土壤呼吸提高旱作春玉米产量

为从农田碳通量角度揭示地膜覆盖种植方式的增产增效机理,于2011年在山西寿阳旱作农业野外试验站对覆膜和露地春玉米田,进行了表层土壤温湿度、土壤呼吸和净碳交换规律及作物生长发育规律的研究和分析。结果表明:与露地处理相比较,覆膜处理全生育期表层土壤含水率提高了18.7%,前期可平均提高表层土壤温度1.67℃。覆膜和露地处理土壤呼吸变化规律总体一致,但前者的温度敏感系数Q10比后者低,且中后期前者排放的碳仅为后者的61.7%,说明采用覆盖地膜种植方式有利于农田土壤碳管理。前期和中期覆膜处理绿叶面积指数比露地处理平均高0.81 m2/m2,后期覆膜处理衰老较快,收获时比露地处理低1.00 m2/m2;露地处理在前期和中期日均净碳通量平均比覆膜处理大0.04 mg/(m2·s),而后期仅小0.02 mg/(m2·s),这是造成2处理最终生物产量和经济产量差异的根本原因。在地上干物质积累和地下干物质积累方面,覆膜处理始终比露地处理高,收获时差值分别为269.7和38.6 g/m2。露地处理每公顷少收春玉米籽粒1 348 kg。由此可见,覆膜种植可提高表层土壤温湿度,促进作物生长发育,抑制土壤呼吸,促进碳积累,增加农民收入的同时更有利于土壤碳管理。     

小麦-玉米-大豆轮作下黑土农田土壤呼吸与碳平衡

农田生态系统是陆地生态系统的重要组成部分,探讨农田生态系统的土壤呼吸与碳平衡对于科学评价陆地生态系统在全球变化下的源汇效应具有重要意义。基于中国科学院海伦农业生态实验站的长期定位试验,对不同施肥处理下黑土小麦-玉米-大豆轮作体系2005—2007年的作物固碳量与土壤CO2排放通量进行了观测,并对该轮作体系下黑土农田生态系统的碳平衡状况进行了估算。结果表明:在小麦-玉米-大豆轮作体系中,作物固碳量的高低表现为:玉米>大豆>小麦,平均值分别为6 513 kg(C).hm-2、4 025 kg(C).hm-2和3 655kg(C).hm-2。从作物生长季土壤CO2排放总量来看,3种作物以大豆农田生态系统的土壤CO2排放总量最高,平均值达4 062 kg(C).hm-2;其次为玉米,为3 813 kg(C).hm-2;而小麦最低,为2 326 kg(C).hm-2。3种作物轮作下NEP(净生态系统生产力)均为正值,表明黑土农田土壤-作物系统为大气CO2的"汇",不同作物系统的碳汇强度表现为玉米>小麦>大豆,三者的平均值分别为3 215 kg(C).hm-2、1 643 kg(C).hm-2和512 kg(C).hm-2。长期均衡施用氮、磷、钾化肥或氮、磷、钾化肥配施有机肥后,小麦、玉米和大豆农田生态系统的固碳量和土壤CO2排放总量均明显增加,并在氮、磷、钾配施有机肥处理下达到最高。不同的施肥管理措施将改变土壤-植物系统作为大气CO2"汇"的程度,总体表现为化肥均衡施用下NEP值较高,而化肥与有机肥配施下农田生态系统的NEP值较低。     

Microbial activity affected by lime in a long-term no-till soil

Under conventional farming practices, lime is usually applied on the soil surface and then incorporated into the soil to correct soil acidity. In no-till (NT) systems, where lime is surface applied or only incorporated into the soil to very shallow depth, lime will likely not move to where it is required within reasonable time. Consequently, lime may have to be incorporated into the soil by mechanical means. The objective of this laboratory study was to characterize the effect of lime, incorporated to different depths, on chemical and biological soil properties in a long-term NT soil. Soil samples taken from the 0–5, 0–10, and 0–20 cm depths were analyzed in incubation studies for soil pH, nitrate, CO₂ respiration, and microbial biomass-C (MBC). Lime (CaCO₃) was applied at rates equivalent to 0, 4.4, 8.8, and 17.6 Mg ha⁻¹. Application of lime to both 0–10 and 0–20 cm depths increased soil pH from about 4.9 by 1, 1.7, and 2.8 units for the low, medium, and high liming rates, respectively. Soil nitrate increased over time and in proportion to liming rate, suggesting that conditions were favorable for N-mineralization and nitrification. Greater respiration rates and greater MBC found in lime-treated than in non-limed soils were attributed to higher soil pH. Faster turnover rates and increased mineralization of organic matter were found in lime-treated than in non-limed soils. These studies show that below-surface lime placement is effective for correcting soil acidity under NT and that microbial activity and nitrification can be enhanced.     

不同品种鲜食核桃冷藏期间呼吸强度及品质变化

为探讨鲜食核桃冷藏期间品质变化规律,在(0±1)℃、相对湿度(RH)70%～80%的贮藏条件下,以辽河4号（L4）、西扶1号（X1）和西扶2 号（X2）核桃品种为试材,采用0.03 mm 厚聚乙烯（PE）袋包装,定期对其相关指标进行测定。结果显示,贮藏初期（15 d）呼吸强度迅速下降,之后维持在低且平稳的水平;3个品种之间水分、脂肪、蛋白质及氨基酸含量均呈现极显著差异;贮藏期间蛋白质含量变化不显著;脂肪、不饱和脂肪酸含量及维生素E含量总体呈现下降趋势;氨基酸含量30 d 时最高,之后保持下降趋势;酸价及过氧化值呈现上升趋势;贮藏中后期（60 d后）酸价、过氧化值、好果率及感官品质急剧下降。结果表明：鲜食核桃贮藏品质受品种影响很大,60 d 为鲜食核桃适宜贮藏期,以L4品质最好。