Relationships between stability of Cu complexes and nitrification inhibition effects of corresponding ligands in soils

In order to investigate the relationships between the stability of Cu complexes and the nitrification inhibition effects of corresponding ligands, the effects of 22 kinds of Cu (II) ligands and eight kinds of Cu (I) ligands were evaluated in three types of soil on nitrification potentials (NPs) under short-term incubation (5 h) and nitrification inhibitory rates (NIRs) under long-term incubation (14 d). The results showed that the inhibitory effect of Cu (II) or Cu (I) ligands on nitrification exhibited significant linear relationships (P < 0.01) with the logarithms of the first stability constants (lgK₁) and the total stability constants (lgK_f) of corresponding complexes. Furthermore, lgK_f of Cu (II) complexes exhibited a greater linear correlation than the corresponding lgK₁ with the nitrification inhibition effects of the corresponding ligands; lgK_f of Cu (I) complexes exhibited a steeper linear relationship than that of Cu (II) complexes with NPs or NIRs, and hence, nitrification inhibition effects of Cu (I) ligands almost doubled that of Cu (II) ligands when the lgK_f values of Cu (I) and Cu (II) complexes have the same changes.     

The reversal effects of recombinant human augmenter of liver regeneration in immunocomplex induced liver fibrosis

AIM: To observe the anti-fibrosis activity of recombinant human augmenter of liver regeneration (hALR). METHODS: Albumin induced rat model of liver fibrosis was established and hALR was given peritoneally after the model production. Serum concentration of alanine aminotransferase(ALT),aspartic aminotransferase(AST),lactate dehydrogenase(LDH), hepatic collagen contents and pathological examination were selected as observing parameter. RESULTS: Recombinant human augmenter of liver regeneration (hALR) could decrease ALT, AST, LDH concentration of fibrotic rats. The measurements of hepatic collagen contents showed that hepatic collagen contents in hALR treatment group was much lower than those of model group and negative control group. Pathological examination also indicated that the degree of liver fibrosis in hALR treatment group was attenuated in comparison with those of model group and negative control group. CONCLUSION: Recombinant human augmenter of liver regeneration (hALR) had reversal effects on immunocomplex induced rat liver fibrosis.control group. CONCLUSION: Recombinant human augmenter of liver regeneration (hALR) had reversal effects on immunocomplex induced rat liver fibrosis.     

分子对接技术在昆虫化学感受研究中的应用进展

分子对接是利用生物信息分析手段预测配体和受体的结构模型,模拟出配体复合物的结构并通过结合自由能来判断结合强度的一种技术。分子对接包括蛋白质和小分子的前期准备,识别结合位点,搜索配体化合物的构象,评估对接结果四部分。昆虫的化学感受途径主要通过化感蛋白与小分子化合物的结合,实现对化学信息素的接收。分子对接可以精确模拟昆虫化感蛋白和信息化合物的结构以及二者的结合形式,可作为研究昆虫化学感受途径的有效技术手段,从而有利于研究开发昆虫抑制剂,用于农林病虫害的防治。本文综述了分子对接技术在昆虫化学感受研究中的应用进展,并详细介绍了分子对接的相关软件,举例说明了分子对接的过程,可为该领域的相关研究提供理论支持和方法指导。     

Oral bovine serum albumin immune‐stimulating complexes improve the immune responses and resistance of large yellow croaker (Pseudosciaena crocea,Richardson, 1846) against Vibrio alginolyticus

This study aimed to investigate effects of bovine serum albumin immune‐stimulating complexes (BSA ISCOMs) on immune‐related genes expression, serum nonspecific immunity and disease resistance of large yellow croaker (Pseudosciaena crocea). Fish were fed diets containing 3.5 ml of BSA ISCOMs per kg feed (experimental group) or 3.5 ml of phosphate‐buffered saline per kg feed (control group) for 1 week. The liver, spleen, head‐kidney tissues were sampled for determining gene expression of myxovirus‐resistant protein (Mx), major histocompatibility complex class II alpha chain (MHC II α), tumour necrosis factor‐alpha (TNF‐α) and interleukin‐10 (IL‐10) 30 and 90 days after feeding. Also, blood samples were collected for determining activities of serum superoxide dismutase (SOD), interferon alpha (IFN‐α), TNF‐α and alkaline phosphatase (ALP). TNF‐α and MHCⅡα gene expression in the liver, spleen, head‐kidney, as well as IFN‐α, TNF‐α and ALP activities in the serum, of experimental fish were significantly higher 30 days after feeding; while only TNF‐α and MHC II gene expression in the head‐kidney remained upregulated 90 days after feeding. The cumulative mortality of the experimental fish was significantly lower than control. This study indicated that BSA ISCOMs improved the immune response and induced protective immunity in large yellow croaker.     

Solubilization of iron by water‐extractable humic substances

The capability of water‐extractable humic substances (WEHS) to solubilize Fe from sparingly soluble Fe‐hydroxide was studied. Addition of WEHS (1.7 mmol organic C l^—1) to a dialysis tube containing labeled insoluble Fe‐hydroxide caused an increase in the amount of ⁵⁹Fe measured in the external solution. The humic fraction was also able to solubilize Fe from soil samples, with levels comparable to those obtained using a solution containing 100�μM DTPA. By measuring the amount of ⁵⁹Fe eluted from soil columns pre‐loaded with ⁵⁹Fe‐WEHS it was possible to evaluate the mobility of Fe complexed to the humic molecules. The recovery of ⁵⁹Fe varied from 2% to 25% in respect to the soil type used. The ability of Fe‐WEHS to serve as an Fe source for the phytosiderophore hydroxy‐mugineic acid (HMA) was also analyzed. The removal of ⁵⁹Fe from the Fe‐WEHS complex by HMA was demonstrated by adding the phytosiderophore to a dialysis tube containing the ⁵⁹Fe‐WEHS complex. The observations suggested a ligand exchange between the phytosiderophore and the humic fraction. The results indicate that WEHS is able to increase the amount of Fe present in the soil solution, possibly by forming mobile complexes with the micronutrient. These complexes could act as easily available Fe sources in Fe acquisition processes by both monocot and dicot plants, playing an important role particularly in soils with low available Fe.     

桑色素络合测定酸性土壤溶液中无机单核铝的方法比较

选择桑色素(Morin)作络合试剂,运用高效液相色谱(HPLC)和荧光分光光度计测定了酸性土壤溶液中的无机单核铝。由分析试剂与铝的比例、络合试剂的溶解介质及缓冲液的pH等的不同形成三种不同的方法。通过比较三种方法的线性范围、准确度和精密度及方法间的相关性,结果表明,采用乙醇溶解的桑色素(1.0×10-4mol L-1)在pH4.0的1.0 mol L-1乙酸铵-乙酸缓冲体系中反应后,荧光分光光度计(Ex=403.3 nm,Em=490 nm)测定酸性土壤溶液中无机单核铝更适宜。     

土壤有机矿质复合体研究Ⅷ.分离钙键有机矿质复合体的浸提剂─-硫酸钠

土壤中通过钙键结合的有机矿质复合体是一种外圈配合物,硫酸钠中的ＳＯ＾２－４作为金属离子的配位体可以与复合体中的Ｃａ＾２＋形成配合物,破坏钙键复合体,并使腐殖质转变为腐殖酸钠盐,从而与铁铝键复合体分离。本文论证了硫酸钠破坏钙键复合体和浸提腐歼击质的能力,证明硫酸钠是区分２钙键复合体和铁铝键复合体的优良试剂;研究了用硫酸钠液分离钙键复合体的方法,并提出了连续浸提铁铝键复合体的后续浸提剂种类。     

高CO2浓度对春兰叶片叶绿素·叶绿素蛋白质复合物含量的影响

[目的]为了研究春兰适应环境变化的方法。[方法]对自然状态（正常组,CO2浓度（370±50）μl/L）和高CO2浓度（试验组,CO2浓度（700±50）μl/L）春兰叶片的叶绿素及叶绿素蛋白质复合物含量进行研究。[结果]与正常组相比,试验组春兰叶片的叶绿素含量增高,叶绿素a/b降低;叶绿素蛋白质复合物的含量增加,经SDS-聚丙烯酰胺凝胶电泳得到6条叶绿素蛋白质复合物带和1条游离色素带,表明叶绿素蛋白质复合物种类未发生变化。从电泳结果可以看出,叶绿素蛋白质复合物聚合态如LHCⅡ3的量增多,单体态LHCⅡ1和LHCⅡ2的量减少。[结论]叶绿素、叶绿素蛋白质复合物含量的变化是春兰对高CO2浓度的一种适应效应,有利于提高其在光合作用中光能的吸收、传递和转换的效率,并且支持高效的光合碳素同化作用。     

水貂循环免疫复合物检测方法的建立及应用

本试验建立了检测水貂循环免疫复合物(CIC)的微量PEG沉淀比浊法和固相C_(1q)—SPA—ELISA.用这两种方法检测了38例健康水貂血清、126例阿留申病(AD)病貂血清.微量PEG沉淀比浊法的结果(OD值,(?)±S)为:健康水貂0.081±0.042,AD病貂0.198±0.066;固相C_(1q)—SPA—ELISA的结果(OD值,(?)±S)为:健康水貂0.245±0.057,AD病貂0.503±0.167,敏感性为0.25μg/mL.经统计学处理,健康水貂与AD病貂血清OD值之间呈极显著差异(P<0.01),表明水貂阿留申病的病理过程与CTC有关.建立的两种方法均具有快速、简便、重复性好和敏感性高等特点,两种方法的相关性显著.     

Immunostimulatory complexes containing Eimeria tenella antigens and low toxicity plant saponins induce antibody response and provide protection from challenge in broiler chickens

Immunostimulating complexes (ISCOMs) are unique multimolecular structures formed by encapsulating antigens, lipids and triterpene saponins and are one of the most successful antigen delivery systems for microbial antigens. In the current study, both the route of administration and the antigen concentration of ISCOMs, containing Eimeria tenella antigens and saponins from native plants, were evaluated in their ability to stimulate humoral immunity and to protect chickens against a challenge infection with E. tenella. Broiler chickens were immunized with ISCOM preparations containing E. tenella antigens and the purified saponins Gg6, Ah6 and Gp7 isolated from Glycyrrhiza glabra, Aesculus hippocastanum and Gipsophila paniculata, respectively. The effects of the route of administration, dose of antigen and type of saponin used for construction of ISCOMs were evaluated for ability to stimulate serum IgG and IgM and to protect chickens against a homologous challenge. A single intranasal immunization was the most effective route for administering ISCOMs although the in ovo route was also quite effective. Dose titration experiments demonstrated efficacy after single immunization with various ISCOM doses but maximum effects were observed when ISCOMs contain 5–10 μg antigen. Immunization of birds by any of the three routes with E. tenella antigens alone or antigens mixed with alum hydroxide adjuvant resulted in lower serum antibody and reduced protection to challenge relative to immunization with ISCOMs. Overall the results of this study confirm that significant immunostimulation and protection to challenge are achieved by immunization of chickens with ISCOMs containing purified saponins and native E. tenella antigens and suggest that ISCOMs may be successfully used to develop a safe and effective vaccine for prevention of avian coccidiosis.