控制光照条件下添加SO_4~（2-）对水稻土中Fe（Ⅲ）还原的影响

为探讨光照和硫酸盐对微生物Fe（Ⅲ）还原的影响,在光照和光暗转换条件下,采用厌氧泥浆恒温培育方法分别在四川和天津2种石灰性水稻土中添加不同浓度硫酸盐溶液（20、50、800mmol·kg-1）,培养过程中定期测定土壤泥浆的Fe（Ⅱ）、叶绿素a含量和pH值。结果表明：光照条件下,添加20mmol·kg-1和50mmol·kg-1硫酸盐能减缓光照培养中因为蓝细菌光合作用放氧引起的Fe（Ⅱ）氧化反应,Fe（Ⅱ）氧化反应启动时间与对照处理相比延迟3～7d;蓝细菌在光照培养5d后开始迅速繁殖生长,叶绿素a增长速率表现为随硫酸盐浓度增大而增加,其最终含量在四川和天津水稻土中分别为20mg·kg-1和16mg·kg-1;800mmol·kg-1硫酸盐则完全抑制了Fe（Ⅱ）的重新氧化,且在整个培养周期中没有发现光合细菌存在。pH值变化呈现先微弱下降后升高的趋势,但始终维持在弱碱性范围内。当由光照转入避光培养后,Fe（Ⅱ）累积量又重新回升,增长速率表现为对照〉20mmol·kg-1S处理〉50mmol·kg-1S处理。表明光照并非直接影响铁还原微生物,而是通过光合微生物繁殖间接影响铁还原过程。     

乙酰乙酸乙酯从盐酸介质中萃取铁的研究

用萃取法从盐酸溶液中分离Fe(Ⅲ ) ,采用常用的有机中间体乙酰乙酸乙酯为萃取剂 ,研究酸度、温度以及盐析剂等条件对萃取分配系数的影响 ,并对铁的反萃取进行讨论 ,从而确定最优萃取条件 ,为植物体内铁的萃取富集分离提供实验依据。     

埃及伊蚊免疫应答相关基因mapk-like的dsRNA原核表达及其饲喂后表达水平的变化

mapk-like是一种信号转导相关促有丝分裂激活蛋白激酶家族基因,与线虫(Caenorhabditis elegans)中参与抵御Cry毒素的p38 MAPK含有类似的模序,其是否参与埃及伊蚊(Aedes aegypti)抵御苏云金芽胞杆菌(Bacillus thuringiensis, Bt)过程有待验证。为简便并大量获得RNAi验证所需的dsRNA,本研究利用RNaseⅢ缺陷型大肠杆菌(Escherichia coli) HT115高效和廉价的优点,根据已测序的促有丝分裂激活蛋白激酶家族基因mapk-like基因序列,设计特异性引物,PCR扩增大小为361 bp的目的片段mapk-like (GenBank登录号：AAEL003728-RA),将其连接到克隆载体pMD18-T上,利用限制性内切酶XbaⅠ和XhoⅠ将其插入到原核表达载体pLitmus28i的2个T7启动子之间,成功构建可诱导形成目的双链RNA (dsRNA)的原核表达重组载体pLitmus28i-mapk-like,并转化大肠杆菌HT115,经IPTG诱导,1 mL菌液的dsRNA产量可达1.18μg,电泳检测条带清晰,质量良好。此外,利用壳聚糖包裹dsRNA形成纳米微粒,上清经电泳检测表明,壳聚糖的聚沉效率良好,纳米微球可有效防止dsRNA从饲料琼脂块中游离出来,提高dsRNA的稳定性。埃及伊蚊幼虫摄取mapk-like基因的dsRNA后,相对转录表达水平为65.55%,表达量明显下调,饲喂效果良好。研究结果将有利于进一步筛选获得相关抵御基因,为建立一个基于RNA沉默防治蚊媒病的研究体系提供了基础资料。     

水稻强化栽培不同因子对Ⅲ优98主要经济性状及产量的影响

为了探索在水稻强化栽培条件下不同密度、纯氮量、2,4-D控蘖试验三因子的最佳组合。采用三元二次旋转组合设计,研究"Ⅲ优98"在强化栽培条件下,移栽密度、纯氮量2、,4-D控蘖三因子对产量及主要经济性状的效应。建立了三因子对产量的二次多项回归效应模型,分析得出高产群体主要经济性状的量化指标。总结出"Ⅲ优98"在强化栽培条件下产量≥8 250 kg/hm2的栽培措施为:移栽密度16.5万~18.0万/hm2,纯氮量196.5~213.0 kg/hm2,2,4-D控蘖时间在群体茎蘖达到248.0万~255.0万/hm2时,三因子取平均值时产量为9 027.0 kg/hm2。在适宜的密度范围内,通过氮肥管理和2,4-D控蘖,使群体和个体各性状协调发展,是实现高产的重要途径。     

茶叶多糖铁的合成及其铁含量的测定

用热水浸泡法从粗老茶叶中提取茶叶多糖,在碱性条件下,茶叶多糖水溶液与三氯化铁反应合成茶叶多糖铁配合物(TPC),并用邻菲罗啉分光光度法和原子吸收光谱法测定TPC中铁(Ⅲ)的含量。实验结果表明:TPC是深棕红色无定型粉末,易溶于水,在pH值3~12范围内不沉淀,不水解。TPC中铁(Ⅲ)的含量:邻菲罗啉分光光度法测定结果为20.71%,原子吸收光谱法测定结果为20.13%。     

Effect of reconstitution and Na2Co3 on tannin content and in vitro protein digestibility of faba bean cultivars

Two faba bean cultivars (317/99/81 and Giaz/402) obtained from Shambat Research Station in Northern Sudan, were used for this study. Investigation showed that the tannin contents of untreated seeds were 0.077% and 0.067% for cultivars 317/99/81 and Giza/402. In vitro protein digestibility values were 80.68% and 81.48% for the two cultivars, respectively. The extractable tannin content of the faba bean cultivars was markedly reduced by imbibing water or Na₂CO₃ solution into whole seeds and incubating them at 30°C for 1, 3, 6, 12 or 24 hours, or at 100°C for 5, 10 or 20 minutes. The extent of reduction depended on time, temperature, and Na₂CO₃ concentration; the percent tannin extracted and percent in vitro protein digestibility increased with time or Na₂CO₃ concentration, while application of high temperature reduced the time.     

Changing rainfall,seasonality and erosivity in the hyper‐arid zone of Sudan

A primary cause of soil erosion is the impact of rain. Therefore, understanding the altering rainfall characteristics and their effect on soil erosion is an issue of main concern. This is of utmost importance to contribute to developing suitable adaptation and mitigation strategies for soil and water resources conservation and crop management practices. The rainfall seasonality index (SI), precipitation concentration index (PCI) and modified Fournier index (MFI) for rainfall erosivity have been calculated and analysed in this study for the hyper‐arid region of Sudan. The data used consist of monthly rainfall measurements spanning over 60 years for three index meteorological stations, two on the Nile corridor and one on the Red Sea coast. The region is characterized by high year‐to‐year variability in rainfall leading to extreme seasonality/irregular distribution of rainfall over the year. Although prevalent diminishing rainfall amounts have been witnessed, there are marked tendencies for some months to become wetter, indicating changing intra‐annual rainfall variability and thus monthly rainfall erosivity. No statistically significant trends were observed in rainfall seasonality and concentration during the common data period of 1945–2007. Cases of high and very high erosion powers were detected. A significant decreasing trend in erosivity is shown for one inland station. A brief discussion on the implications of these results for risk of soil erosion, freshwater quality and agriculture is also given. Copyright © 2010 John Wiley & Sons, Ltd.     

Change of antithrombin Ⅲ in patients with atherosclerotic cerebral infarction

AIM：To explore the change of antithrombin Ⅲ (AT-Ⅲ) in the patients with atherosclerotic cerebral infarction. METHODS：Chromogenic substrate assay was used to measure the activity of AT-Ⅲ in 55 patients with atherosclerotic cerebral infarction and 55 healthy controls, and the correlation analysis was applied to determine the AT-Ⅲ activity with the severity of damage in central nervous system and general biochemical parameters. The levels of TNF-α and IL-6 in the plasma were detected by ELISA. Immunocomplex in the plasma was measured by enzyme immunoassay （EIA）. The number and phenotype of the monocytes in peripheral blood were analyzed by flow cytometry. ELISA was also applied to determine the secretion of TNF-α and IL-6 from the monocytes after the stimulation of immunocomplex. The expression of AT-Ⅲ in human brain vascular endothelial cells after the stimulation of TNF-α and IL-6 was observed by Western blotting. RESULTS：The activity of AT-Ⅲ significantly decreased in the patients with atherosclerotic cerebral infarction, and negatively correlated with the damage degree of nervous system function, systolic pressure, diastolic pressure, glucose, cholesterol, triglyceride, low-density lipoprotein cholesterol and homocysteine, while positively correlated with high-density lipoprotein. In addition, the plasma levels of TNF-α and IL-6 increased significantly, accompanied with the enhancement of immunocomplex level. The numbers of CD14+ CD16+ and CD14+ CD32+ monocytes in peripheral blood were not changed, while CD14+ CD64+ monocytes increased obviously. The secretion of TNF-α and IL-6 by monocytes were significantly enhanced after stimulated with immunocomplex, while the protein expression of AT-Ⅲ in the human brain vascular endothelial cells was down-regulated after co-incubated with TNF-α or IL-6. CONCLUSION：Decreased AT-Ⅲ activity in the patients with atherosclerotic cerebral infarction is one of the risk factors of cerebral infarction, and related with the disease severity. The production of pro-inflammatory cytokines through immunocomplex from CD14+ CD64+ monocytes may be involved in the mechanism. Improvement of AT-Ⅲ activity may protect against cerebral ischemia.     

豫南地区杨树舟蛾类害虫飞机喷药防治试验

利用飞机喷洒25%阿维·灭幼脲3号悬浮剂,对添加不同比例高效氯氰菊酯和不同施药时期的防治效果进行研究,试验发现每架次添加1.5 kg 5%高效氯氰菊酯油剂(两种药剂的质量比为24∶1.5),能快速有效防治杨树舟蛾类害虫。6月中下旬豫南地区杨树舟蛾类害虫为二代2～3龄幼虫期,是施药防治该类害虫的最佳时期。     

迟钝爱德华氏菌Ⅲ型分泌系统基因的克隆及多重PCR检测方法的建立

采用PCR法扩增大菱鲆Scophthalmus maximus出血性败血症病原菌迟钝爱德华氏菌Edwardsiella tarda L-49231菌株Ⅲ型分泌系统(TTSS)的装置蛋白(esaC)、效应蛋白(eseB、eseC、eseD)和调节蛋白(esrA、esrB)6种基因,并将其克隆到载体PMD19-T中分别进行测序;通过优化反应条件,建立一次检出效应蛋白eseB、eseC和eseD 3种基因片段的多重PCR方法;采用所建立的多重PCR方法检测迟钝爱德华氏菌不同菌株(L-49231、GhAn080310、GhAn080313和GhAn080314)、沙门氏菌Salmonella enterica、大肠杆菌Escherichia coli和肠杆菌Enterobacter中效应蛋白基因的存在情况.结果表明:L-49231菌株中存在esaC、eseB、eseC、eseD、esrA和esrB 6种基因片段,大小分别为837、184、934、445、464、458 bp,与GenBank 中迟钝爱德华氏菌PPD130/91菌株的这6种基因的同源性分别为99％、97％、99％、99％、99％、98％;通过优化反应条件,在退火温度为54 ℃,基因eseB、eseC和eseD引物浓度(μmol/L)组合比为5∶10∶2,Mg2+浓度为1.5 mmol/L时,能够得到清晰、稳定且均一的多重PCR产物,并与目的条带分子量一致;采用所建立的多重PCR方法进行检测,迟钝爱德华氏菌L-49231菌株中存在eseB、eseC和eseD 3种基因片段,迟钝爱德华氏菌GhAn080310、GhAn080313、GhAn080314菌株中存在eseB和eseC基因片段,但未检出eseD基因片段;沙门氏菌、大肠杆菌和肠杆菌中均未检出eseB、eseC和eseD基因.表明所建立的多重PCR方法对迟钝爱德华氏菌具有较好的特异性,可检出具有Ⅲ型分泌系统效应蛋白的菌株.