营养水平对肉鸡肌肉组织学的影响

试验设计了 9种能量或蛋白质水平不同的饲粮 ,研究了不同营养水平对肉鸡胸肌组织学的影响。结果表明 :饲粮能量或蛋白质水平增加 ,肉鸡胸肌纤维密度减小、直径增大 (P <0 0 1 )。所有处理中 ,高能中蛋白组试鸡胸肌纤维密度最小、直径最大 ,低能低蛋白组试鸡胸肌纤维密度最大 ,高能低蛋白组试鸡胸肌纤维直径最小。     

IGF-1 receptor signaling pathways and effects of AMPK activation on IGF-1-induced progesterone secretion in hen granulosa cells

IGF-1 plays a key role in the proliferation and differentiation of granulosa cells. However, the molecular mechanism of IGF-1 action in avian granulosa cells during follicle maturation is unclear. Here, we first studied IGF-1 receptor (IGF-1R) expression, IGF-1-induced progesterone production and some IGF-1R signaling pathways in granulosa cells from different follicles. IGF-1R (mRNA and protein) was higher in fresh or cultured granulosa cells from the largest follicles (F1 or F2) than in those from smaller follicles (F3 or F4). In vitro, IGF-1 treatment (10(-8)M, 36h) increased progesterone secretion by four-fold in mixed F3 and F4 (F3/4) granulosa cells and by 1.5-fold in F1 granulosa cells. IGF-1 (10(-8)M, 30min)-induced increases in tyrosine phosphorylation of IGF-1R beta subunit and phosphorylation of ERK were higher in F1 than in F3/4 granulosa cells. Interestingly, IGF-1 stimulation (10(-8)M, 10min) decreased the level of AMPK Thr172 phosphorylation in F1 and F3/4 granulosa cells. We have recently showed that AMPK (AMP-activated protein kinase) is a protein kinase involved in the steroidogenesis in chicken granulosa cells. We then studied the effects of AMPK activation by AICAR (5-aminoimidazole-4-carboxamide ribonucleoside), an activator of AMPK, on IGF-1-induced progesterone secretion by F3/4 and F1 granulosa cells. AICAR treatment (1mM, 36h) increased IGF-1-induced progesterone secretion, StAR protein levels and decreased ERK phosphorylation in F1 granulosa cells. Opposite data were observed in F3/4 granulosa cells. Adenovirus-mediated expression of dominant negative AMPK totally reversed the effects of AICAR on IGF-1-induced progesterone secretion, StAR protein production and ERK phosphorylation in both F3/4 and F1 granulosa cells. Thus, a variation of energy metabolism through AMPK activation could modulate differently IGF-1-induced progesterone production in F1 and F3/4 granulosa cells.     

基于链接分析法的节能服务公司网站影响力评价研究

节能服务公司作为我国节能减排事业的重要力量,需充分发挥互联网的优势,扩大其网站影响力,推动行业健康发展。文章以41个节能服务公司网站作为研究样本,利用网页总数、总链接数、外链接数、内链接数、网络影响因子、外部网络影响因子、内部网络影响因子、PR值8个指标数据,运用链接分析法及灰色关联分析法对上述网站的网络影响力进行分析评价。指出我国节能服务公司网站建设的优点和不足,为网站自身优化提供思路。     

On the Analysis of EMCS and Its Application in the Project of Shenzhen Underground

In this paper, the selection of type, function and technological requirements of EMCS for Shenzhen Underground has been introduced.Based on the investigation for EMCS's worldwide applications and the analysis of practice in Shenzhen Underground, the comparison and selection of PLC and DDC have been done completely.At the same time,the introduction of EMCS is organized by the center level, station level and the spot level.     

不同熟期夏玉米品种生长发育特性与产量形成的关系

【目的】研究不同熟期夏玉米品种生长发育特性与产量形成的关系,以期为早熟、高产、适应机械粒收的玉米新品种的筛选提供理论依据。【方法】2017年以早熟玉米品种登海518（DH518）、衡早8号（HZ8）和中晚熟玉米品种登海605（DH605）、郑单958（ZD958）为试验材料,2018年以早熟玉米品种登海518（DH518）、京农科728（JNK728）和中晚熟玉米品种登海605（DH605）、郑单958（ZD958）为试验材料,种植密度为75 000株/hm²,研究玉米生长发育过程中的叶片建成规律、穗部发育特性以及各生育阶段对光温需求的差异。【结果】不同熟期夏玉米品种各生育阶段的光温需求大小表现为吐丝期（R1）—生理成熟期（R6）>出苗期（VE）—吐丝期（R1）>播种期（sowing）—出苗期（VE）。不同品种花后对积温的需求高于花前,中晚熟和早熟夏玉米品种对积温需求的差异主要在拔节期—吐丝期,具体表现为第9—16片叶建成期;花后对积温的需求品种间差异不显著。相关性分析表明,不同熟期夏玉米品种的产量与穗位高、穗高系数呈极显著正相关关系。不同熟期夏玉米品种的雄穗发育特性不同,晚熟品种的雄穗长度显著低于早熟品种,但晚熟品种的雄穗分枝数、雄穗总小花数、小花败育率、有效小花数显著高于早熟品种;而雌穗分化到籽粒形成受品种基因型影响较大。【结论】不同熟期夏玉米品种生长发育特性具有较大差异,在75 000株/hm²条件下,中晚熟品种的产量显著高于早熟品种;植株总叶片数较少,拔节期—吐丝期所需时间短,后期脱水速率快是早熟宜机收玉米品种的典型特征。     

Role of PPARα/PGC-1α in doxorubicin induced mouse dilated cardio-myopathy

AIM: To investigate the changes of peroxisome proliferator-activated receptors (PPAR)α/peroxisome proliferator activated receptor coactivator 1 alpha (PGC-1α) in doxorubicin (DOX) induced dilated cardiomyopathy (DCM) and its effect on the energy metabolism and myocardial function in mice. METHODS: Forty mice were randomly divided into 4 groups: control group, DOX group, PPARα inhibitor group and PPARα agonist group. The DCM model was established by injection of DOX. The protein levels of PPARα/PGC-1α were detected. The PPARα inhibitor and PPARα agonist were used 2 weeks beforeinjection of DOX. The contents of adenine acid and phosphocreatine (Pcr) in the mitochondria were measured by high-performance liquid chromatography (HPLC). The ANT activity was analyzed by the atractyloside-inhibitor stop technique. The changes of the echocardiography and hemodynamics were also observed. RESULTS: DOX induced DCM model was successfully established. The protein levels of PPARα and PGC-1α in control group were significantly higher than those in DOX group (P<0.05). Both of the high-energy phosphate contents and the transport activity of ANT were decreased in DOX group (P<0.05), and the hemodynamic parameters were disordered (P<0.01). Compared with DOX group, PPARα inhibitor pre-treatment significantly reduced the PPARα/PGC-1α expression. Meanwhile, high-energy phosphate contents in the mitochondria and the ANT transport activity of the mitochondria decreased, as well as the left ventricular function (P<0.05). On the other hand, PPARα agonist significantly increased the expression of PPARα and PGC-1α, and improved the transport activity of ANT. In addition, the hemodynamic parameters were ameliorated, but the high-energy phosphate contents of the mitochondria did not significantly change. CONCLUSION: PPARα/PGC-1α plays an important role in the regulation of ANT transport activity in dilated cardiomyopathy induced by DOX, and the activation of PPARα/PGC-1α has protective effects on the DCM induced by DOX.     

Seasonal variations of nitrous oxide emission in relation to nitrogen fertilization and energy crop types in sandy soil

Nitrous oxide (N₂O) is a greenhouse gas and agricultural soils are major sources of atmospheric N₂O. Its emissions from soils make up the largest part in the global N₂O budget. Research was carried out at the experimental fields of the Leibniz-Institute of Agricultural Engineering Potsdam-Bornim (ATB). Different types (mineral and wood ash) and levels (0, 75 and 150 kg N ha⁻¹) of fertilization were applied to annual (rape, rye, triticale and hemp) and perennial (poplar and willow) plants every year. N₂O flux measurements were performed 4 times a week by means of gas flux chambers and an automated gas chromatograph between 2003 and 2005. Soil samples were also taken close to the corresponding measuring rings. Soil nitrate and ammonium were measured in soil extracts.N₂O emissions had a peak after N fertilization in spring, after plant harvest in summer and during the freezing–thawing periods in winter. Both fertilization and plant types significantly altered N₂O emission. The maximum N₂O emission rate detected was 1081 μg N₂O m⁻² h⁻¹ in 2004. The mean annual N₂O emissions from the annual plants were more than twofold greater than those of perennial plants (4.3 kg ha⁻¹ vs. 1.9 kg ha⁻¹). During January, N₂O fluxes considerably increased in all treatments due to freezing–thawing cycles. Fertilization together with annual cropping doubled the N₂O emissions compared to perennial crops indicating that N use efficiency was greater for perennial plants. Fertilizer-derived N₂O fluxes constituted about 32% (willow) to 67% (rape/rye) of total soil N₂O flux. Concurrent measurements of soil water content, NO₃ and NH₄ support the conclusion that nitrification is main source of N₂O loss from the study soils. The mean soil NO₃-N values of soils during the study for fertilized soils were 1.6 and 0.9 mg NO₃-N kg⁻¹ for 150 and 75 kg N ha⁻¹ fertilization, respectively. This value reduced to 0.5 mg NO₃-N kg⁻¹ for non-fertilized soils.     

不同水平维生素A对意大利蜜蜂春繁阶段群势及幼虫抗氧化性的影响

【目的】研究日粮中添加不同水平维生素A对意大利蜜蜂春繁阶段群势和幼虫虫体抗氧化活性的影响。【方法】春繁开始时选用本地意大利蜜蜂25群（群内无花粉贮备）,随机分为5组,分别饲喂添加了不同水平维生素A的试验日粮,维生素A水平分别为0、5 000、10 000、15 000、20 000 IU•kg-1,并测定各组蜂群群势及幼虫抗氧化活性。【结果】春繁阶段饲粮中维生素A添加水平对意大利蜜蜂群势及取食量有显著影响。在试验期末,维生素A水平为10 000 IU•kg-1组群势显著高于对照组和其它试验组（P＜0.05）;饲喂维生素A水平为10 000和15 000 IU•kg-1饲料时5日龄幼虫虫体抗氧化活性（总抗氧化能力（T-AOC）、总超氧化物岐化酶（T-SOD）活性、过氧化氢酶（CAT）活性）显著高于对照组和其它试验组（P＜0.05）,丙二醛（MDA）含量显著低于对照组和其它试验组（P＜0.05）;除维生素A水平为15 000 IU•kg-1组外,10 000 IU•kg-1组工蜂初生重显著高于对照组和其它试验组（P＜0.05）。【结论】意大利蜜蜂春繁阶段适宜的维生素A添加水平（10 000—15 000 IU•kg-1）有利于蜂群群势的增长和抗氧化能力的提高。     

BMY公牛对不同能量蛋白比日粮的消化代谢试验

[目的]为了研究12月龄BMY公犊牛对不同日粮中各营养成分的代谢情况。[方法]采用12月龄BMY公犊9头,分成3组,分别饲喂低能低蛋、中能中蛋和高能高蛋比日粮。[结果]日粮中DM、N、ADF和NDF的表观消化率随着日粮中能量蛋白比水平的提高而增加,其中,三个试验组间DM和N的表观消化率之间无显著性差异（P〉0.05）,但低能量蛋白比日粮组的N表观存留率、ADF和NDF的表观消化率显著低于中、高两个试验组（P〈0.05）,而中和高蛋白能量比日粮组N的表观存留率、ADF和NDF的表观消化率之间无显著性差异（P〉0.05）。     

饲粮不同蛋白质、能量水平对大白鼠生长发育及体成分的影响

本试验所用动物为53—57日龄雄性大白鼠(sprague——Dawley品系),初始体重为121.73±3.95g,试验期为大白鼠生长发育旺期的21天。试验拟研究不同粗蛋白水平(10％、15％、20％、25％和30％)及两个能量水平(消化能:3.6和3.9kcal/g)的饲粮对大白鼠生长发育及各种体成分的影响。结果表明,当饲粮蛋白质供应充分时,大白鼠生长随饲粮能量浓度的提高而改善;而当饲粮蛋白质供应感觉不足时,提高能量浓度对生长无益。机体各项成分指杯中,以蛋白质、脂肪、水分沉积受饲粮蛋白质,能量浓度影响显著;而蛋白质、脂肪沉积在很大程度上受饲粮能朊比的影响,饲粮中添加脂肪可使大白鼠机体肥胖。