生物法制备平台化合物乙偶姻的最新研究进展

乙偶姻(3-羟基-2-丁酮)作为一种应用广泛的食用香料和重要的平台化合物,具有广阔的工业应用前景。与传统的化学合成方法不同,高效、环保的乙偶姻生物制备方法,可以减轻资源和环境压力,促进我国低碳经济的发展。近来,生物法制备平台化学品乙偶姻取得了丰硕的研究成果。总结了最近几年国内外在该领域最新的研究热点及方向,简述了发酵法生产乙偶姻的优势菌株概况,重点综述了以糖类物质为底物生产乙偶姻的最新策略及研究成果、将微生物改造为生产手性乙偶姻的高效细胞炼制工厂以及将2,3-丁二醇或双乙酰作为发酵底物的研究趋势,并介绍了乙偶姻的分离纯化工艺。使用非致病性的安全菌株,高效率地利用廉价底物,并采用经济、简单、环保的分离纯化方式,从而生产具有高附加值的食品级或高手性纯度乙偶姻,是生物法制备乙偶姻产业化发展的可靠保障。     

人呼吸道合胞病毒截短F1重组蛋白包涵体的制备、纯化和复性

目的将前期在大肠埃希杆菌中获得表达的A型人呼吸道合胞病毒兰州分离株截短的F1重组蛋白进行纯化和复性,为后期动物免疫制备抗原。方法 37℃诱导重组菌体p ET-42b-F1J/Rossata,诱导完毕后离心收集菌体,高压破碎菌体并收集包涵体后用不同浓度的Triton X-100(细胞裂解液)洗涤包涵体3次。洗涤的包涵体用8 mol/L尿素进行溶解并用镍离子亲和层析方法进行初步纯化,用阳离子交换层析方法对初步纯化蛋白进行最终的纯化。亲和层析纯化蛋白用3种不同的复性液进行了稀释复性。结果 37℃诱导5 000 m L重组菌p ET-42b-F1J/Rossata共收获37 g湿菌体,经过不同浓度Triton X-100洗涤包涵体后纯度可达75%。包涵体用8 mol/L尿素溶解后经镍离子亲和层析纯化纯度约为40%,再用阳离子交换层析介质SP HP进一步纯化样品后纯度可达90%。纯化蛋白以3种不同的复性液都能得到复性,其中复性液3的复性效果相对较好。结论实验中探索了人呼吸道合胞病毒截短F1重组蛋白包涵体的纯化方法及步骤,为后期的蛋白制备及动物免疫奠定了基础。     

外周5-羟色胺在胰岛素抵抗中的作用研究进展

5-羟色胺（5-HT）作为一种神经递质在中枢神经系统中具有重要的作用,同时在外周组织系统中5-HT也发挥多种重要的生物功能, 如广泛参与机体的糖脂代谢、肝再生、胃肠运动等。综述外周5-HT诱导胰岛素抵抗的作用机制研究新进展,重点介绍5-HT对胰岛素信 号转导、糖脂代谢等方面的影响。     

Comparative mapping reveals similar linkage of functional genes to QTL of yield-related traits between <Emphasis Type="Italic">Brassica napus</Emphasis> and <Emphasis Type="Italic">Oryza sativa</Emphasis>

Oryza sativa and Brassica napus-two important crops for food and oil, respectively-share high seed yield as a common breeding goal. As a model plant, O. sativa genomics have been intensively investigated and its agronomic traits have been advanced. In the present study, we used the available information on O. sativa to conduct comparative mapping between O. sativa and B. napus, with the aim of advancing research on seed-yield and yield-related traits in B. napus. Firstly, functional markers (from 55 differentially expressed genes between a hybrid and its parents) were used to detect B. napus genes that co-localized with yield-related traits in an F(2:3) population. Referring to publicly available sequences of 55 B. napus genes, 53 homologous O. sativa genes were subsequently detected by screening, and their chromosomal locations were determined using silico mapping. Comparative location of yield-related QTL between the two species showed that a total of 37 O. sativa and B. napus homologues were located in similar yield-related QTL between species. Our results indicate that homologous genes between O. sativa and B. napus may have consistent function and control similar traits, which may be helpful for agronomic gene characterization in B. napus based on what is known in O. sativa.     

Intraspecific divergences of Rhodiola alsia (Crassulaceae) based on plastid DNA and internal transcribed spacer fragments

In the present study, we used two maternally inherited plastid DNA intergenic spacers, rpl20‐rps12 and trnS‐trnG, and the biparentally inherited nuclear ribosomal internal transcribed spacer (ITS) region to explore genetic variation and phylogeographical history of Rhodiola alsia, a herb endemic to the Qinghai‐Tibetan Plateau (QTP). Based on range‐wide sampling (18 populations and 227 individuals), we detected 45 plastid DNA haplotypes and 19 ITS sequence types. Only three plastid DNA haplotypes were widespread; most haplotypes were restricted to single sites or to neighbouring populations. Analysis of molecular variance revealed that most of the genetic variance was found within populations (51.24%) but that populations were also distinct (F_ST = 0.48759). We found three areas with relatively high plastid DNA diversity and these could further be recognized as potentially isolated divergence centres based on the ITS sequence type distribution. These represent three potentially isolated glacial refugia for R. alsia: one of them has long been recognized as an important refugium on the south‐eastern edge of the QTP, whereas the others are new and located in the north and south of the Tanggula Mountains on the plateau platform. Divergence time estimates based on ITS suggest that the main lineages of R. alsia diverged from each other 0.35–0.87 Mya, indicating that climatic oscillations during the Pleistocene may have been an important driver of intraspecific divergence in R. alsia. Rhodiola alsia probably experienced a phylogeographical history of retreat to isolated glacial refugia during Quaternary glaciations that led to different degrees of allopatric intraspecific divergence. © 2011 The Linnean Society of London, Botanical Journal of the Linnean Society, 2012, 168 , 204–215.     

两种广西特有报春苣苔属(苦苣苔科)植物传粉生物学研究

通过野外观察和室内试验,对两种广西特有的桂林小花苣苔和阳朔小花苣苔的传粉生物学进行比较研究。结果表明:两种报春苣苔属植物花期从7月底至8月初;单花花期内花粉具有较高的活性,最高可达92.6%和94.5%;柱头可授性最高时可达90%和95%;花粉/胚珠比率(P/O)分别为110.28±17.45和229.65±18.00;柱头与花药之间存在着空间隔离,可防止自花授粉;在单花花冠裂片张开后第3天,花药开始散粉,但雌蕊在花朵刚开始开放时已伸长,待第3天时柱头已伸长到位于花冠筒口部,高于花药,便于接受异花花粉;该两种植物均不存在无融合生殖现象;两种报春巨苔属植物均高度自交亲和,但很难发生自发的自花授粉,必须依靠外力,因此传粉媒介对于结实率有重要影响,自然条件下基本不发生自花授粉;在自然状态下结实率明显低于两种人工授粉的结实率;小蜂和淡脉隧蜂是目前已知仅见的两种传粉者。     

镉对尖紫蛤抗氧化酶活性及脂质过氧化的影响

为阐明镉(Cd2+)对尖紫蛤消化盲囊和鳃抗氧化酶的毒性影响程度,研究了不同浓度的Cd2+(0.005、0.05、0.5 mg/L)在不同暴露时间(24h、72h、120h)对尖紫蛤鳃和消化盲囊中超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、谷胱甘肽过氧化物酶(GSH-PX)的活性以及丙二醛(MDA)含量的影响。结果表明,在Cd2+浓度为0.005 mg/L时,在整个实验期间Cd2+对消化盲囊和鳃内的SOD、CAT、GSH-PX活性并无显著影响。在Cd2+浓度为0.05 mg/L和0.5 mg/L时,SOD、CAT、GSH-PX在鳃和消化盲囊中的活性都呈现出明显的时间剂量依赖关系。在0.05 mg/L暴露时,鳃和消化盲囊中的SOD、CAT和GSH-PX的活性随时间逐渐增强,在72h时达到最大值,但在120h时略有降低。在0.5 mg/L暴露时,消化盲囊中SOD、CAT及鳃中CAT活性在24h时上升达到最大值,但鳃中SOD直到72h才达到最大值,并均在120h下降到最低,其中消化盲囊中SOD和CAT活性在120h低于对照组,这可能与消化盲囊对Cd2+的敏感性高于鳃有关。在0.5 mg/L暴露的鳃中,GSH-PX在24h、72h活性并不上升,在120h甚至低于正常水平,0.5 mg/L暴露的消化盲囊中,24h时迅速增高,然后逐渐下降到正常值。这可能与Cd2+结合了GSH-PX的活性中心,降低了GSH-PX的活性有关。与3种酶活性随着时间延长和剂量的增加,酶活性会降低的变化趋势不同,鳃和消化盲囊中的MDA的含量随时间延长和剂量的增加而增加,并不出现下降,这表明尖紫蛤鳃和消化盲囊中的MDA含量可以灵敏的反映机体内的氧化损伤程度,但不能敏感的反映水体中Cd2+的污染情况。     

基于地统计学和CFI样地的浙江省森林碳空间分布研究

基于浙江省2009年CFI固定样地数据、森林资源规划设计调查林相图,利用地统计学方法对浙江省森林碳空间分布进行了模拟分析。结果表明,CFI固定样地数据用于省域范围的森林碳汇空间特征研究是合适的。数据显示,浙江森林植被平均碳密度为22.07Mg/hm2;与四川、福建、海南等地相比,平均碳密度较低。受人类活动、自然环境等因素影响,浙江省森林碳分布主要表现为:总体上森林碳密度空间变化趋势自西向东逐渐降低,与自然空间(海拔、地势等)趋势一致。基于地统计学和CFI固定样地,对省域范围的森林资源空间分布的研究,可以为省域森林碳汇管理提供依据,为我国特别是亚热带南方集体林区利用国家CFI数据进行大区域同类研究提供借鉴。     

常山县儿童2004-2010年交通伤害监测结果分析

目的 了解常山县儿童青少年交通伤害发生状况,为制定预防干预措施提供依据.方法 根据《全国伤害监测方案》,在常山县人民医院、招贤中心卫生院、辉埠卫生院建立医院急诊伤害监测系统,以首次在监测医院就诊的各类伤害病例作为监测对象,采用哨点监测方式,以年度为单位持续进行医院伤害监测.结果 常山县2004-2010年监测医院共报告交通伤害病人14 122例,其中儿童青少年交通伤害1 937例,占13.72％;以5～14岁在校学生为多,占14.71％;交通伤害中男、女之比为1.66:1;伤害发生原因机动车车祸比非机动车车祸多.伤害发生场所以公路/街道为主,占94.11％;伤害发生时活动以驾乘交通工具和休闲活动为多,分别占52.30％和32.32％.结论 5～14岁在校学生为伤害预防干预的重点.应有针对性地开展预防干预措施,减少伤害的发生.     

施肥对两种苋菜吸收积累镉的影响

通过盆栽试验,研究了生长在5 mg/kg镉(Cd)污染土壤中的两种苋菜(红苋(Amaranthus Paniculatus L.)和绿苋(Amaranthus Paniculatus L.))在3种施肥处理下(N、NP和NPK)的生长状况和对Cd的吸收积累情况。结果表明,两种苋菜能够在污染土壤中正常生长,各器官中叶Cd含量最高,范围为124.1—225.9 mg/kg;根中次之,范围为57.1—100.6 mg/kg;茎中最低,范围为56.2—87.6 mg/kg;富集系数高达22.4—40.2。施加N,NP,NPK肥对两种苋菜器官中的Cd含量和生物量有显著影响。其中,施加NPK肥使红苋和绿苋的生物量分别达到不施肥(对照)处理的3.5和3.2倍,单株提取Cd的总量是对照3.2和5.0倍。综上表明,两种苋菜(红苋和绿苋)具有生物量大、易栽培、施加NPK肥能够大幅增加生物量的同时不减少器官对Cd的吸收等优点,作为Cd污染土壤的修复植物有巨大应用前景。