Detection of non‐equilibrium contaminant release in soil columns: Delineation of experimental conditions by numerical simulations

Robust and reliable laboratory methods are required to assess the rate of release of pollutants from contaminated materials. A widely used approach to determine release parameters are soil column experiments. Release rates are thereby obtained by the analysis of the concentration time profile measured at the column outlet, the so called breakthrough curve. Insufficient experimental information as a consequence of simple experimental designs, however, results in the non‐unique identification of the release processes. This is due to the equifinality, i.e., different processes result in the same breakthrough behavior. We analyzed column outflow experiments for their suitability for the identification of non‐equilibrium conditions by means of numerical simulations. Results show that non‐equilibrium conditions can be detected only in a small range of release time scale to transport time scale. Most frequently, non‐equilibrium remains undetected due to unmatched experimental conditions. Flow interruptions and modulation of the flow velocity are an important means to allow for better detection of possible non‐equilibrium release processes. The efficiency of flow interruptions sensitively depends on the experimental conditions, such as point of time and duration of the interruption and the imposed flow velocity. Column experiments are a suitable experimental tool to investigate non‐equilibrium. However, the course of the experiment has to be designed very carefully.     

Surface distribution of pyrethroids following topical application to veterinary species: Implications for lateral transport

Pyrethroids like permethrin have been used as topical formulations for their ectoparasiticidal effects since the 1970s. There are numerous efficacy studies in dogs and livestock animals that indicate a fast spread of pyrethroids after topical administration onto rather confined areas of the skin. Some studies correlate the efficacy against ticks, fleas or lice with concentrations of pyrethroids in hair and, less frequently, stratum corneum samples. It is often stated that lateral transport is responsible for the distribution of the pyrethroids over the body surface. With this review, we attempt to demonstrate evidence for lateral transport of pyrethroids after topical administration in dogs, cattle and sheep and to present data gaps that should be addressed in follow‐up studies.     

The effect of vitamin E treatment on selected immune and oxidative parameters in Kivircik ewes suffering from transport stress

The study aimed to investigate the effects of vitamin E injection for the prevention of transport stress on ewes. Kivircik ewes (2–3 years old, n = 24) were randomly separated into three groups; G1 (Control) and G2 treated with 14 ml. saline as the placebo, G3 treated with 2100 IU/ind. DL-alpha-tocopherol acetate prior to transport. G2 and G3 were transported at 80 km/h for 4 h on a truck. Serum samples were obtained before (T0) and after (T1) transport. Serum cortisol, catalase, IgG, ceruloplasmin, C-reactive protein, complement component 4, interleukin-1 beta, tumour necrosis factor-alpha, glutathione peroxidase (GPx), superoxide dismutase, malondialdehyde analyses performed by ELISA, and serum alpha-tocopherol concentrations were evaluated by HPLC-UV. Wilcoxon and Kruskal–Wallis tests were used for statistical assessments (p < 0.05). Alpha-tocopherol concentrations were founded 1.22 ± 0.82, 0.27 ± 0.14 and 0.14 ± 0.07 µmol/L, respectively, in G1, G2 and G3 at T1. Alpha-tocopherol concentration decreased significantly in G2 between T0 and T1. GPx concentrations were increased twofold in G2 and G3 between T0 and T1 (p < 0.01). As a result, G2 alpha-tocopherol concentrations decreased but, the stress and oxidative parameters tested in this study were not affected by treating 2100 IU/ind. DL-alpha-tocopherol acetate before transport.     

中国鲷科鱼类分类和系统发育研究进展

为研究黑鲷(Sparus inacrocephalus)增殖放流最适宜运输密度及运输后生理生化变化情况,选取全长9~11.7 cm的黑鲷鱼苗为实验对象,设计5个密度组(10尾、15尾、20尾、25尾和30尾)采用塑料袋密封充氧运输方式,即塑料袋中充等量的海水并充氧至饱和,水体为育苗池海水,水温27.7 ℃,盐度29,pH 8.04,溶解氧8.8 mg·L^–1,运输2.75 h。分别于运输后暂养的第0、第6、第12、第24和第48小时取样,研究黑鲷鱼苗血清和肌肉中总蛋白(TP)、超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、丙二醛(MDA)等指标的变化情况。结果显示,不同密度的塑料袋密封充氧运输后,10尾组和15尾组血清和肌肉中的TP和MDA浓度低于30尾组(P<0.05),而SOD和CAT活性显著高于30尾组(P<0.05);从暂养后恢复水平上看,10尾组和15尾组肌肉和血清中各项指标恢复最快,20尾组和25尾组次之,30尾组的各项指标恢复较慢且至实验结束时未能全部恢复。综合经济因素分析,在水温27.7 ℃、盐度29、pH 8.04的条件下运输9~11.7 cm黑鲷鱼苗2.75 h时,用塑料袋密封充氧运输的最佳密度为每袋25尾。     

龙眼生长素受体基因TIR1密码子偏好性分析

为了解龙眼生长素受体基因TIR1密码子的使用特性,采用CodonW、SPSS软件及EMBOSS在线程序分析龙眼TIR1密码子的偏好性,并分别与龙眼基因组、其他29个物种TIR1以及模式生物基因组进行比较。结果显示,龙眼TIR1与龙眼基因组的密码子选择偏性较弱且较偏好以A/T结尾,而物种间TIR1密码子选择偏性则存在一定差异;进化树分析表明,基于TIR1编码序列聚类结果比密码子使用偏性分类结果能更准确地反映物种间的亲缘关系;密码子使用频率比较结果发现,酵母真核表达系统更适用于龙眼TIR1异源表达试验,而龙眼TIR1与模式植物基因组之间密码子使用偏性差异较小,尤其烟草和番茄可能为该基因转基因研究最为理想的受体。     

NO诱导IAA和O2.-积累于侧根尖端促进水稻侧根生长

为了探讨NO和超氧阴离子对水稻种子根侧根生长的影响,以DR5-GUS标记IAA的转基因水稻为材料,种子催芽萌发后,用含有不同浓度的NO供体、NO合成酶抑制剂和清除剂溶液来培养萌发3 d的水稻幼苗,在培养的第3 d和第5 d分别测量初生根长度和初生根上侧根数量,并通过DAF-2DA对NO、GUS对IAA和NBT对超氧阴离子（O₂·^-）染色后,在显微镜下观察NO、IAA和O₂·^-在侧根的定位,分析与NO合成相关的基因表达。结果表明,NO和IAA主要分布在根中柱的维管束部分以及侧根起始形成处和侧根根尖,O₂·^-只极性分布在侧根起始部位和侧根根尖。当NO合成受到抑制或清除时,NO、IAA和O₂·^-在侧根的积累量明显减少,侧根数量及初生根长度也均显著下降。荧光定量PCR分析发现,外源的NO供体SNP处理均能显著诱导水稻OsNIA1和OsNIA2基因表达,而NO合成酶抑制剂处理则抑制OsNIA1和OsNIA2基因表达。基于我...     

植物生长素受体蛋白研究现状

目的对大白菜生长素受体BrTIR1/AFBs基因家族进行系统分析,为大白菜BrTIR1/AFBs基因家族的功能挖掘和性状遗传改良提供理论依据。方法利用生物信息学方法,分析大白菜生长素受体基因家族的进化关系、编码蛋白、保守结构域和顺式作用元件。基于NCBI转录组测序(RNA-sep)数据,分析BrTIR1/AFBs基因家族在大白菜不同组织中的表达模式以及在根肿病入侵条件下的表达情况。结果从大白菜基因组数据库中鉴定得到10个BrTIR1/AFBs基因。拟南芥、茎瘤芥和大豆生长素受体基因家族多序列比对以及系统进化树分析结果显示：BrTIR1/AFBs基因分为6个亚家族(TIR1、AFB1、AFB2、AFB3、AFB4和AFB5),处于同一亚族的基因具有相似的结构。染色体定位结果显示：BrTIR1/AFBs基因家族成员分布在除Chr5、Chr6和Chr10号染色体之外的7条染色体上,呈现出不均匀分布。顺式作用元件分析结果显示：所有的BrTIR1/AFBs基因家族成员都含有响应生长素、防御和逆境胁迫的作用元件,预示着这些基因可能参与相应的生物学过程。组织表达模式分析发现：10个BrTIR1/AFBs基因的转录本在6个组织中被检测到,且不同组织中的表达量存在明显差异。大白菜BrTIR1/AFBs基因家族成员在根肿病病原菌入侵时表达量发生显著变化。结论大白菜生长素受体BrTIR1/AFBs基因家族成员具有保守的基因结构和功能结构域,在大白菜不同组织中发挥着特异的功能,且在抵御病害和干旱等逆境中发挥重要作用。     

The Biosynthesis and Transport of Carnitine and its Application in Animal Husbandry

Carnitine,an indispensable metabolite,was found in muscle in 1905.Carnitine plays an important role in the transport of long-chain fatty acids from cytosol to the mitochondrial matrix,where fatty acid β-oxidation takes place.In recent years,carnitine,an essential nutrient in improving livestock production and reproductive performance,has more and more widely application in animal production.In this review,we summarize the biosynthesis and transport of carnitine,as well as the application of animal production,which provides theoretical basis and insight into further research on carnitine.     

植物离体嫁接假酸浆/假酸浆的发育过程

通过光镜观察发现:在离体条件下,嫁接后3 d 在自体嫁接假酸浆/假酸浆愈伤组织细胞中分化出管状分子和筛分子;贯通接穗和砧木的维管组织桥在嫁接后5 d 形成,整个嫁接发育过程约在嫁接后15 d 完成。用~(14)C 标记的蔗糖检验了同化物自接穗向砧木的输导,发现在嫁接后5 d 自接穗进入砧木的输导量有一个飞跃,揭示韧皮部桥在此期产生对同化物的输导能力。     

蛋鸡离体小肠对Gly-L-Leu肽的吸收转运研究

本试验采用离体外翻肠囊法研究了蛋鸡小肠对Gly-L-Leu肽的吸收和转运.将6只206日龄的海兰褐蛋鸡的小肠分割为十二指肠、空肠前、中、后段和回肠5段,分别制备外翻肠囊.每3只鸡的肠囊为1个试验组,将灌注浆膜液(含Ca2+/Mg2+PBS缓冲液)的各肠囊置于相同的二肽培养液(含20mmoL/LGly-L-Leu的Ca2+/Mg2+PBS缓冲液)中进行培养.试验1组培养液添加了肽酶抑制剂(10μmoL/L Bestatin和Amastatin),试验2组浆膜液添加了等量的肽酶抑制剂.培养15分钟后测定培养液、浆膜液、肠组织匀浆液中二肽和游离氨基酸的含量.结果表明,鸡十二指肠、空肠前、中段对Gly-L-Leu有强烈的水解作用,空肠后段和回肠的水解能力相对较弱.鸡各肠段均能迅速吸收Gly-L-Leu,并将其转运到浆膜液中.吸收量和转运量有沿肠道延伸而增强的趋势.