珠三角河网初级生产力时空差异及其影响因素

为评价珠三角河网初级生产力,于2015年3月、6月、9月、12月对其进行取样调查,采用多元统计方法研究初级生产力时空差异及其与环境因素关系。结果表明,珠三角河网初级生产力(碳,C)为98.81~927.21mg·(m~2·d)~(-1),均值为346.51 mg·(m~2·d)~(-1)。调查区域初级生产力季节变化明显,总体上表现为春季冬季夏季秋季。各站位初级生产力均值以珠江桥站位最高[600.61 mg·(m~2·d)~(-1)],市桥站位最低[232.60 mg·(m~2·d)~(-1)]。初级生产力与透明度、氮磷营养盐、叶绿素a呈正相关关系(P0.01,n=52),与硅酸盐呈负相关关系(P0.01,n=52),与水体富营养化综合指数(EI)呈线性相关关系。珠三角河网以中营养、富营养为主体,与其他水域相比,初级生产力较低,污染程度较严重,需防止其向富养化发展。     

Air-drying changes the distribution of Hedley phosphorus pools in forest soils

Hedley labile phosphorus(P)pools in soil tend to be several times larger than annual forest requirements,even in highly weathered soils characterized by P limitation.The discrepancy between plant and soil P status could be partly attributable to the frequently adopted air-drying pretreatment that tends to increase soil P solubility.In this study,the effects of air-drying on the distribution of Hedley P fractions were examined using soils collected under 4 forest types at Gongga Mountain,southwestern China.The results showed that the microbial biomass P(Pmic)in the organic horizon decreased markedly after air-drying.The concentrations of Hedley labile P in the air-dried samples were 31%–73%more than those in the field-moist samples.Consequently,the air-drying-induced increments of Hedley labile P pools in the surface soil horizons were 0.8–3.8 times the annual plant P requirements.The organic horizon was more susceptible to the air-drying-induced increases in Hedley labile P than the mineral horizon,probably because of the stronger release of Pmicand disruption of soil organic matter.The quality of P,indexed by the ratio of Hedley labile P to slowly cycling P,shifted in favor of the Hedley labile fractions after air-drying,further revealing that air-drying changed the distribution of Hedley P pools in forest soils.These indicated that the effects of air-drying could not be ignored when interpreting the discrepancy between the P status of plants and the Hedley labile P pools in forest soils.To more efficiently evaluate the P status in forest soils via the Hedley fractionation procedure,the use of field-moist soils is recommended.     

能量溢出与储备碳水化合物合成对瘤胃微生物生长效率影响的研究进展

瘤胃微生物将一些ATP用来维持代谢,剩余的ATP用来进行储备碳水化合物合成和能量溢出（进行无效循环并产热）,因此,瘤胃微生物蛋白质合成效率较低。瘤胃原虫贮存的碳水化合物占绝大部分。在一些细菌纯培养实验中发现有能量溢出,最近研究发现在混合瘤胃菌群中也能发生能量溢出。通过精确测定碳水化合物贮存和能量溢出的量,以及二者对微生物生长效率的影响,可以预测微生物蛋白质产量,制定提高瘤胃微生物蛋白质生产效率的措施。综述了瘤胃微生物能量溢出和糖原储备规律方面的研究进展,以期为估测微生物蛋白质合成量,提高饲料蛋白质利用效率提供参考。     

基于现场总线思想的分布式温室智能控制系统

温室自动控制系统是提高温室生产经济效益的关键之一。参照自动控制系统的发展趋势，开发了基于现场总线思想的分布式温室自动控制系统；系统硬件由上位机、智能控制器和智能节点3层组成，采用485总线作为层间通信网络。系统软件应用了实时数据库、智能控制、开放的通信协议、实时决策及模型更新和双向看门狗技术。大约1年多的实际运行效果显示，系统功能完善、可靠性高，适合在温室生产中推广应用。     

18种中草药煎液对温和气单胞菌的抑、杀菌效果

采用琼脂扩散法(打孔法)测定了五倍子等18种中草药对2株病原温和气单胞菌(Aerom onas sobria)的抑制作用,并采用试管2倍稀释法测定抑菌效果较强的中草药对这2株温和气单胞菌的抑菌和杀菌浓度。结果显示:五倍子、苏木、地锦草、石榴皮、黄芩、虎杖和山楂对病原温和气单胞菌的抑菌效果较强;苏木、五倍子、地锦草和石榴皮4种中药对2株温和气单胞菌的最小抑菌浓度(M IC)为1.56～6.25 mg/mL之间,最小杀菌浓度(MBC)为3.12～12.5 mg/mL之间,其中五倍子的抑菌和杀菌浓度最低,分别为1.56 mg/mL和3.12 mg/mL;而金银花等11种中草药抑菌作用较小。结果表明,所选取的18种中草药中五倍子对防治由温和气单胞菌感染引起的水产动物疾病最为有效。     

PPARγ agonist pioglitazone attenuates cortical neuron lesion and gliosis in rat brain of post-traumatic injury

AIM: To investigate the neuroprotective effect of pioglitazone (Pio), a potent agonist of peroxisome proliferator-activated receptor gamma (PPARγ), on the traumatic brain injury (TBI) in rats. METHODS: SD rats were randomly divided into 4 groups: sham group, vehicle+TBI group, Pio+TBI group and Pio+T0070907+TBI group. TBI was induced by the method of controlled cortical impact (CCI) injury. Neutral red staining technique was used to determine the cortical lesion volume. NeuN, GFAP and OX-42 were measured by immunohistochemical technique to evaluate the morphology of neurons, activation and infiltration of astrocytes and microglia at the edge of cortical lesion. RESULTS: CCI injury in rat elicited activation and proliferation of the astrocytes and microglia. The glial scar wall formation at the edge of cortical lesion, which was accompanied by the loss of neurons, was observed. Pio significantly reduced the cortical lesion volume, the activation and infiltration of the astrocytes and microglia, and the loss of pyramidal neurons at the edge of cortical lesion. T0070907, an antagonist of PPARγ, reversed the effects of Pio. CONCLUSION: Pioglitazone exerts a neuroprotective efficacy, attenuates the loss of neurons and cortical lesion volume following CCI injury by inhibiting the activation and infiltration of astrocytes and microglia, especially glial scar formation.     

多功能直流比较仪式校验装置在校准中的应用

多功能直流比较仪式校验装置结构简单、原理明确.介绍多功能直流比较仪式校验装置测量电阻的工作原理,详细说明使用该校验装置校准电阻的操作步骤.相比于传统方法,使用该校验装置校准电阻更为准确.     

白藜芦醇通过激活去乙酰化酶1/腺苷一磷酸激活的蛋白激酶信号通路影响牛脂肪细胞凋亡

本试验旨在研究植物提取物白藜芦醇(RES)对牛皮下脂肪细胞凋亡率以及去乙酰化酶1(SIRT1)/腺苷一磷酸激活的蛋白激酶(AMPK)信号通路关键因子的mRNA和蛋白质表达量的影响。选取18月龄鲁西黄牛的皮下前体脂肪细胞,在细胞分化的第0天,更换为RES浓度分别为0(对照)、100、200和400μmol/L的培养液处理48 h,每组设3个重复。应用Hoechst33342染色检测细胞凋亡的形态学变化,流式细胞分析仪检测细胞凋亡率,荧光定量PCR(q PCR)和免疫印迹试验(Western-blot)分别检测SIRT1/AMPK信号通路上的关键因子SIRT1、A MPKα、叉头转录因子1(Fox O1)、B细胞淋巴瘤/白血病-2(Bcl-2)、半胱氨酸天冬氨酸蛋白酶-3(caspase-3)、促凋亡蛋白Bcl-2相关X蛋白(Bax)的mRNA和蛋白质表达量,并利用油红O染色鉴定脂肪细胞。结果表明,与对照组相比:不同浓度RES处理后的牛皮下脂肪细胞凋亡率均极显著增高(P0.01);不同浓度RES处理后的SIRT1、AMPKα、caspase-3、Bax的mRNA表达量均显著或极显著提高(P0.05或P0.01),Bcl-2的mRNA表达量极显著降低(P0.01);不同浓度RES处理后的SIRT1、AMPKα、caspase-3的蛋白质表达量均显著或极显著提高(P0.05或P0.01);200和400μmol/L RES处理后,Fox O1的mRNA和蛋白质表达量显著或极显著提高(P0.05或P0.01),Bax的蛋白质表达量极显著提高(P0.01),Bcl-2的蛋白质表达量极显著降低(P0.01)。100μmol/L RES处理后时,Fox O1的mRNA和蛋白质表达量以及Bcl-2、Bax的蛋白质表达量均与对照组差异不显著(P0.05)。由此可见,RES通过激活SIRT1/AM PK信号通路,同时激活通路下游的Fox O1,促进了牛皮下脂肪细胞的凋亡,为通过营养调控技术降低牛皮下脂肪沉积提供了一定的理论基础。     

生地黄提取物的制备及其卷烟应用

为开发新型天然烟用香料,采用热回流提取工艺制备生地黄提取物。以提取物得率、感官品质为评价指标,利用单因素试验结合Box-Behnken响应面分析方法对热回流提取工艺中关键参数进行优化,并对其在卷烟中的应用效果进行评价。结果表明,最佳提取工艺条件为提取温度85℃,提取时间55 min,提取溶剂为50%乙醇,料液比1∶12,此时提取物得率为42.0%,且添加量为0.1%~0.4%时感官品质最佳,可丰富烟香,改善余味,增甜增润。     

PrGV多角体膜蛋白（PEP）的分析

【目的】对菜粉蝶颗粒体病毒(Pieris rapae Granulovirus,PrGV)多角体膜蛋白(polyhedron envelope protein,PEP)进行研究,为揭示PEP的功能及其在病毒生命过程中的作用提供参考。【方法】以PrGV PEP为对象,通过序列分析、原核表达、抗体制备、Western blotting、胶体金免疫定位、实时荧光定量PCR等方法初步确认该基因定位和表达时相。【结果】PrGV PEP与其他鳞翅目昆虫颗粒体病毒的PEP同源性达到50%左右,但未在核型多角体病毒(Nucleo polyhedro virus,NPV)中发现同源序列。定量PCR分析表明,菜青虫感染PrGV后24h可检测到PEP的存在,随后该基因的表达水平逐渐升高,并在72h达到峰值。通过Western blotting可以在感染PrGV的菜青虫体内检测到大小分别为23ku和15ku的清晰条带,说明制备的多克隆抗体具有较好的特异性。免疫金标记将PEP定位于椭圆型的颗粒体,证明PEP是GV包涵体的重要组成部分。【结论】PrGV PEP在颗粒体病毒中较为保守,可能是PrGV晚期表达的重要基因,参与病毒侵染后期颗粒体结构的形成。