改性尿素对土壤N2O排放的影响

N2O是仅次于CO2和CH4的第三种温室气体,改性尿素是减少农田N2O排放的一种重要途径。通过室内瓶培养试验,研究几种改性尿素对旱田和稻田土壤N2O排放的影响,结果表明:当旱田土壤含水量较低(23%)时,NI(尿素 硝化抑制剂)的N2O减排效果最好,其次为FL(尿素 HQ DCD)。当旱田土壤含水量较高(34%)时,FL的N2O减排效果最好,其次为NI。当稻田土壤处于淹水状态时,MEI(包被尿素)的N2O减排效果最好,其次为FL。结果对农田选用优良改性尿素、环境保护和可持续发展具有指导意义。     

Histological, digestive, metabolic, hormonal and some immune factor responses in Atlantic salmon, Salmo salar L., fed genetically modified soybeans

The paper reports the second and final part of an experiment aiming to study physiological and health-related effects of genetically modified (GM) soybean meal (SBM) type Roundup Ready soybean (RRS) in diets for post-smolt Atlantic salmon. For 3 months salmon were fed diets containing 172 g kg(-1) full-fat SBM from RRS (GM-soy) or an unmodified, non-isogenic line (nGM-soy), or a reference diet with fishmeal as the sole protein source (FM). Slight differences in anti-nutrient levels were observed between the GM and nGM-soy. Histological changes were observed only in the distal intestine of the soy-fed fish. The incidence of moderate inflammation was higher in the GM-soy group (9 of 10 sampled fish) compared with the nGM-soy group (7 of 10). However, no differences in the concomitant decreases in activities of digestive enzymes located in the brush border (leucine aminopeptidase and maltase) and apical cytoplasm (acid phosphatase) of enterocytes or in the number of major histocompatibility complex class II+ cells, lysozyme activity, or total IgM of the distal intestine were observed. GM compared with nGM-soy fed fish had higher head kidney lysozyme (11,856 vs. 10,456 units g(-1) tissue) and a tendency towards higher acid phosphatase (0.45 vs. 0.39 micromol h(-1) kg(-1) body mass in whole tissue) activities, respectively. Plasma insulin and thyroxin levels, and hepatic fructose-1,6-bisphosphatase and ethoxyresorufin-O-deethylase activities were not significantly affected. It is not possible, however, to conclude whether the differences in responses to GM-soy were due to the genetic modification or to differences in soy cultivars in the soy-containing diets. Results from studies using non-modified, parental line soybeans as the control group are necessary to evaluate whether genetic modification of soybeans in diets poses any risk to farmed Atlantic salmon.     

土壤富里酸对镉的吸附特征与影响因素的研究

采用改进的连续电位滴定法,研究了土壤富里酸对重金属镉吸附量的主要影响因素。结果表明：富里酸溶液的pH值升高,吸附量增加;富里酸浓度升高,吸附量降低;pH值升高、富里酸浓度增大,吸附率增大。吸附量和pH值之间的关系可用自然对数方程进行拟合．同时富里酸浓度越小、镉离子浓度越高,方程的斜率越大,说明吸附量的大小同时与二者密切相关。分别用Linear方程、Fruendlich方程和Langmiur方程对富里酸一镉的吸附等温线进行拟合,结果发现,pH值大于5．0时,上述方程拟合均较好;pH值小于5．0时,只能用Langmiur方程拟合。富里酸对镉的吸附系数随着pH值的升高而降低。     

基于网络药理学探究乌梅散加减方治疗猪传染性胃肠炎的作用机制

【目的】借助网络药理学手段探究乌梅散加减方治疗猪传染性胃肠炎(TGE)的作用机制。【方法】利用中药系统药理学数据库与分析平台(TCMSP)、Swiss TargetPrediction获取乌梅散加减方的活性成分与作用靶点,应用公共比较毒理基因组学数据库(CTD)获取TGE的相关靶点,使用STRING数据库绘制乌梅散加减方与TGE交集靶点的蛋白互作(PPI)网络图,利用DAVID对交集靶点进行GO功能和KEGG通路富集分析,探究乌梅散加减方治疗TGE的作用机制。【结果】从乌梅散加减方中共筛选到槲皮素、山柰酚、芒柄花素等125种活性成分和JUN原癌基因(JUN)、肿瘤坏死因子(TNF)、信号传导与转录激活因子3(STAT3)等58个作用靶点。GO功能富集分析显示,共得到生物过程138个条目,涉及免疫反应、血管内皮因子生成、RNA聚合酶Ⅱ启动子对pri-miRNA转录的正调控等;细胞组分13个条目,涉及胞外区、细胞外空间、膜筏等;分子功能32个条目,涉及细胞因子活性、生长因子活性、白细胞介素2(IL2)受体活性等。KEGG通路富集分析显示,共得到135条信号通路,其中IL17信号通路、Th1...     

转基因作物的生态环境安全性

转基因作物是一把“双刃剑”,既带来了巨大的经济效益,也给自然生态环境带来了一些不利影响。一是对非靶标生物的影响;二是基因逃逸问题;三是转基因作物生存优势的影响。但是,种植转基因作物可以减少农药对人畜的伤害,可以进行保护地耕作,可以利用转基因作物消除环境中的重金属等污染物。为此,必须对转基因作物的研究和利用采取一种系统的思维方式,对其过程要进行严格管理和监控。     

应用多重荧光PCR快速筛查作物中转基因成分研究

通过对我国批准进口的和获得农业转基因生物安全证书的转基因玉米转化体的序列分析发现,除DAS40278-9和BLVA430101外,CaMV35s启动子、NOS终止子、CrylAb/Ac基因和pat基因覆盖了 21种玉米转基因转化体.通过引物组合筛选、反应体系优化、灵敏度测试、适用性测试等实验,建立了基于4个通用筛选元件...     

Analysis of the seed dispersal patterns of wild soybean as a reference for vegetation management around genetically modified soybean fields

There are concerns that genetically modified soybean might threaten the genetic diversity of the wild soybean populations that are distributed in East Asia because genetically modified soybean has no crossing barrier with wild soybean. A simple and effective method to prevent hybridization via pollen flow is spatial separation between the two species because their hybridization occurs only when they grow in close proximity. Therefore, the invasiveness of wild soybean needs to be known in order to secure the appropriate distances. As wild soybean seeds are dispersed mechanically by pod dehiscence, an experiment was conducted in which white sheets were placed on the ground, concentric circles were drawn around the parent plants, and the number of dispersed seeds within each 0.5 m‐wide zone were counted. About 40% of the produced seeds were dispersed and the number of dispersed seeds gradually declined as the distance from the parent plants increased. The model that explained the relationship between the number and distance of the dispersed seeds was produced by using a generalized linear model procedure. More than 95, 99, and 99.9% of the produced seeds stayed within 3.5, 5.0, and 6.5 m after natural pod dehiscence. Knowing these values is useful for evaluating the level of invasive risk by mechanical seed dispersal. The goal of the work is to efficiently and deliberately prevent hybridization by isolating genetically modified soybean fields and wild soybean populations by vegetation management, including weeding and setting up specific‐width buffer zones.     

磁性纳米粒子的制备及在转基因大豆检测中的应用

利用热分解法和表面4-羧基苯硼酸修饰,制备了用于转基因大豆提取基因组DNA的纳米粒子。制备的纳米粒子分散性好,磁响应性高。对比磁性纳米粒子和植物基因组DNA提取试剂盒提取转基因大豆基因组DNA的提取效果,结果表明,磁性纳米粒子提取转基因大豆基因组DNA的浓度明显高于试剂盒,实时荧光PCR检测转基因大豆的Ct值低于植物基因组提取试剂盒。     

兽用基因工程生物制品的安全控制对策与措施( II )——生物安全性评价

本文阐述了与兽用基因工程生物制品的生物安全性评价有关的动物病原体的危害性分类与生物安全等级、安全性评价的内容和要求及制品的安全性复核检验等内容     

感官剖面分析法在调制乳感官分析技术中的应用研究

以麦香调制乳的感官剖面分析为例,通过描述词的收集和删减、使用描述词培训感官评价小组、建立感官剖面图来分析说明感官剖面分析法在调制乳的感官分析技术中的应用。通过分析比较说明,感官剖面分析法可以量化感官特征,建立行之有效的感官分析控制体系,为调制乳产品的研发和质量控制提供感官分析技术。