不同品种大果沙棘在山西引种栽培试验

为了解大果沙棘优良品种在山西的适应性,于2010年从辽宁引进9月黄、壮圆黄、杂1、杂3、杂4、西伯利亚红晕6个大果沙棘品种在山西进行栽培试验,观察存活情况、生长表现、初期结实情况,以评价不同品种大果沙棘在山西引种栽培初期的适应性。结果表明,6个引进沙棘品种均能正常生长、结实;不同品种大果沙棘的生长特性、适应性不同,其中,杂3品种生长旺盛、引种效果良好。     

盐胁迫下高粱幼苗生长及其对耐盐性评价的影响

以糖度及其它农艺性状差异较大的6个高粱株系为材料,研究不同浓度盐胁迫处理7天和14天后高粱幼苗的苗高、鲜重、饱和鲜重及干重的变化以及对苗期耐盐性鉴定评价的影响。结果表明:随着盐浓度的升高以及胁迫时间的延长幼苗生长受到的抑制增大,苗高、鲜重、饱和鲜重和干重均随盐浓度的升高而降低。在0、50、100 mmol/L NaCl浓度下,处理7天和14天的苗高差异显著;当NaCl浓度大于150 mmol/L时,各浓度间苗高均没有显著差异。处理14天后,50 mmol/L和100 mmol/L,150 mmol/L和200 mmol/L两个浓度间的苗鲜重、饱和鲜重及干重无显著差异,其它各浓度间差异显著。在4个盐浓度中,苗高、鲜重、饱和鲜重和干重的相关性均达显著性水平,但是仅在100 mmol/L和150 mmol/L浓度下,耐盐级别与盐害指数呈显著正相关。     

柠檬酸杆菌N10的分离及其溶藻特性

以铜绿微囊藻(Microcystis aeruginosa)为溶解对象,利用液体感染分离技术从浙江大学华家池校区湖水样品中分离到1株溶藻菌N10,对其生长及溶藻相关特性进行了研究.结果表明:经过16SrDNA核苷酸序列分析,该菌株属于柠檬酸杆菌属(Citrobacter sp.);当N10无细胞培养物(cell-free culture filtrate,CCF)与铜绿微囊藻液按照体积比为1∶5混合后,在24h内N10CCF对铜绿微囊藻的溶藻率可达到86.55%,并且溶藻率随着溶藻时间的延长而增强,在72h内溶藻率可达到97.08%;对N10生长量影响最大的是pH值,其次是NaCl质量分数,最后是温度,但N10菌株对铜绿微囊藻的溶藻率受培养温度和培养基中NaCl质量分数的影响很小;N10菌株通过分泌一种对高温(115℃)敏感但却能抗蛋白酶K的物质来溶解铜绿微囊藻;透射电子显微镜观察表明,经过N10CCF处理后的藻细胞出现了细胞膜、细胞壁破裂,伪空胞结构、细胞质中磷酸颗粒以及蓝色体等颗粒性物质消失,细胞中的光合片层排列趋于松散且混乱的现象.     

Licochalcone a inhibits lipopolysaccharide-induced inflammatory response in vitro and in vivo

Licochalcone A (Lico A), a flavonoid found in licorice root (Glycyrrhiza glabra), is known for its antimicrobial activity and its reported ability to inhibit cancer cell proliferation. In the present study, we found that Lico A exerted potent anti-inflammatory effects in in vitro and in vivo models induced by lipopolysaccharide (LPS). The concentrations of TNF-α, interleukin (IL)-6, and IL-1β in the culture supernatants of RAW 264.7 cells were determined at different time points following LPS administration. LPS (0.5 mg/kg) was instilled intranasally (i.n.) in phosphate-buffered saline to induce acute lung injury, and 24 h after LPS was given, bronchoalveolar lavage fluid was obtained to measure pro-inflammatory mediator and total cell counts. The phosphorylation of mitogen-activated protein kinases (MAPKs) and nuclear factor-κB (NF-κB) p65 protein was analyzed by Western blotting. Our results showed that Lico A significantly reduced the amount of inflammatory cells, the lung wet-to-dry weight (W/D) ratio, protein leakage, and myeloperoxidase activity and enhances oxidase dimutase activity in mice with LPS-induced acute lung injury (ALI). Enzyme-linked immunosorbent assay results indicated that Lico A can significantly down-regulate TNF-α, IL-6, and IL-1β levels in vitro and in vivo, and treatment with Lico A significantly attenuated alveolar wall thickening, alveolar hemorrhage, interstitial edema, and inflammatory cells infiltration in mice with ALI. In addition, we further demonstrated that Lico A exerts an anti-inflammation effect in an in vivo model of acute lung injury through suppression of NF-κB activation and p38/ERK MAPK signaling in a dose-dependent manner.     

Comparison of three DNA extraction methods for feed products and four amplification methods for the 5'-junction fragment of Roundup Ready soybean

Three methods of DNA extraction from feed products and four detection methods for the 5'-junction fragment of genetically modified (GM) Roundup Ready soybean (RRS) were compared and evaluated. The DNA extraction methods, including cetyltrimethylammonium bromide (CTAB), sodium dodecyl sulfate (SDS), and guanidine hydrochloride (Kit), were assessed for their yields and purity of DNA, extraction time, and reagent cost. The DNA yields of CTAB, SDS, and Kit were 52-694, 164-1750 and 23-105 ng/mg sample, and their extraction time was 2.5-3, 2-2.5, and 1.5-2 h with reagent cost about US dollar 0.24, 0.13, and 1.9 per extraction, respectively. The SDS method was generally well suited to all kinds of feed matrices tested. The limits of detection for the four amplification protocols, including loop-mediated isothermal amplification (LAMP), hyperbranched rolling circle amplification (HRCA), conventional polymerase chain reaction (PCR), and real-time PCR, were 48.5, 4.85, 485, and 9 copies of the pTLH10 plasmid, respectively. The ranked results of the four detection methods were based on multiattribute utility theory as follows (from best to worse): HRCA, LAMP, PCR, and real-time PCR. This comparative evaluation was specifically useful for selection of a highly efficient DNA extraction or amplification method for detecting different GM ingredients.     

石羊河流域农田休闲期耗水规律研究

通过微型蒸渗器和diviner2000土壤水分测定仪测定了不同耕作及储水灌溉条件下农田休闲期土壤水分动态变化规律,并结合气象数据比较不同耕作方式和灌水处理的优越性,分析了休闲期不同耕作方式及储水灌溉措施对土壤水分及降水利用的影响。研究结果表明,春耕可减少农田表层土壤蒸发,保水效果较好;低定额储水灌溉既没有造成深层渗漏,且蒸发损失小;冬季大定额储水灌溉产生43.86 mm的深层渗漏和121.11mm的土壤水分蒸发,形成了水资源的无效流失;而春耕+免储水灌溉只产生54.41 mm水分损失,节水效果显著。土壤蒸发和深层渗漏产生的土壤水分损失大小顺序为:传统冬季储水灌溉>低定额储水灌溉>秋耕+免储水灌溉>春耕+免储水灌溉,低定额储水灌、秋耕+免储水灌溉、春耕+免储水灌溉处理土壤水分损失较对照分别减少53.44 mm、97.52 mm和110.56 mm(土面蒸发+深层渗漏)。石羊河流域春耕+免储水灌溉处理可有效减少休闲期水分损失,提高休闲期水分利用效率。     

土壤中微量钒的分光光度测定方法研究 ——1 （2 吡啶偶氮） 2 萘酚-过氧化氢-十二烷基苯磺酸钠法

对钒(V)和1-(2-吡啶偶氮)-2-萘酚(PAN)-过氧化氢-十二烷基苯磺酸钠(SDBS)显色反应进行了试验,结果表明:在1 mol.L-1盐酸介质中,在SDBS存在下,钒与1-(2-吡啶偶氮)-萘酚和过氧化氢生成红色的多元络合物,络合物最大吸收波长为575 nm,表观摩尔吸收率为3.64×104L.mol-1.cm-1,钒的浓度在0.2～1.2μg.mL-1内符合比耳定律。络合物的组成比为n钒∶nPAN∶n过氧化氢=1∶1∶1。该方法用于土壤中钒的测定,测定值的相对偏差(n=20)均小于6%,回收率为100.4%～105.6%。     

轴流泵叶轮出口尾迹区非定常压力和速度场特性

为了分析轴流泵叶轮出口尾迹和势流交替干扰特性,基于RNGk-ε湍流模型和SIMPLE算法,对南水北调工程用轴流泵模型进行了数值计算。通过定常预测的外特性结果与试验值进行比较,验证了计算网格和湍流模型的适用性,并在此基础上计算了轴流泵叶轮出口尾迹区非定常流场特性。研究结果表明,通过轴流泵全流场数值计算结果与试验值对比,在最优工况下计算扬程相对误差为4.56%,效率相对误差为2.78%,较好反映了轴流泵内部流动特性;在小流量工况下,轴流泵叶轮出口圆周方向轴面速度存在与叶片数相同的3个主波峰和3个次波峰;随着流量增大,叶轮出口圆周方向速度分布图中的波峰与导叶叶片数相同。在小流量工况和设计工况下,叶轮出口尾迹区压力脉动时域图出现3个主波峰,随着流量增大,额外产生了3个次波峰。基于FFT变换发现不同流量工况下的压力脉动主频均以叶频为主,其他谐频以叶频为基频,呈倍数出现,且主频的幅值随着流量减小而迅速上升。     

云南红河烟区覆膜方式及移栽苗龄对烤烟产量和品质形成的影响

采用田间试验,分析不同覆膜方式与移栽苗龄对云南红河烟区烤烟成苗率、返苗期、农艺性状、主要病害发病率和病情指数、烟叶化学成分及经济性状的影响,以探索出适合该产区优质高产的烤烟种植技术。结果表明,从覆膜方式来看,膜下移栽要比膜上移栽效果好,成苗率较高,返苗期较短,发病率和病情指数较低,经济效益较高;从不同苗龄的烟株来看,除膜上中苗移栽处理外,其余处理均呈现苗龄越大,各指标表现越差的现象。因此,在膜下移栽适宜采用小苗（4叶1心）,烟株长势最好,农艺性状指标在所有处理中表现最优;而在膜上移栽适宜采用中苗（6叶1心）,其烟株田间生长发育最好。     

Determination of organochlorine pesticide residues in river sediments by soxhlet extraction with hexane-acetone

Soxhlet extraction with hexane + acetone (1 + 1 by volume) was used for the extraction of organochlorine pesticide residues from river sediments, followed by Florisil column chromatography clean-up and determination by gas chromatography with an electron-capture detector. Average recoveries exceeding 90 % were obtained using this technique. Organochlorine pesticide residue levels in sediment samples from two major rivers flowing through predominantly rice-growing areas were determined by this method. Relatively high residue levels of organochlorine pesticides such as HCH, heptachlor and endosulfan were found in the sediments.