Presence of surfactant proteins in the uteri and placentae of pregnant mares

Immunohistochemical investigations of the expression of surfactant protein A (SP-A) and surfactant protein D (SP-D) in the uterine and placental tissues of 13 pregnant mares were performed using anti-horse monoclonal primary antibodies. Strong positive reactions for both SP-A and SP-D were observed in the trophoblasts in the microcotyledons of the placentae at 182 to 314 days of gestation; in uterine glandular epithelial cells, faint-to-weak reactions were observed during gestation. This study describes, for the first time, the changes in the SP-A and SP-D expression levels in the endometrium of mares during gestation; the SP-A and SP-D expression levels increased after the second trimester of gestation.     

Mechanisms of Surfactant-Enhanced Air Sparging

The changing mechanisms of air saturation in groundwater in different air travelling modes during surfactant-enhanced air sparging were investigated using a series of one-dimensional column experiments with the media of medium sand (025～050 mm) and gravel (5～10 mm) respectively. The results demonstrate that when air travels in the form of discrete channels, air saturation increases gradually with surface tension decreasing. When the surface tension is 495 mN/m, air saturation would not increase but slightly decreases instead. The decrease of capillary pressure caused by surface tension reduction is the main cause of increase of air saturation. When air travels in the form of bubbles, the air saturation improves gradually as the surfactant concentration decreases when the SDBS concentration is lower than 1 000 mg/L, and air saturation in porous media is directly affected by foam stability.     

阴/非表面活性剂对菲污染砂土柱淋洗研究

采用玻璃土柱法比较研究了1000、2000、3000和4000mg·L^-1的阴离子表面活性剂十二烷基苯磺酸钠（SDBS）、非离子表面活性剂聚氧乙烯山梨糖醇酐单油酸酯（Tween80）及不同质量配比的混合表面活性剂（SDBS-Tween80）（S∶T=1∶1、1∶2和1∶4）对砂土中菲的柱淋洗。结果表明,SDBS对菲的淋洗曲线总体上呈现先上升到峰值而后下降的变化规律,且呈锯齿形波动;而Tween80与SDBS-Tween80对菲的淋洗曲线具有相似的规律,即淋出液中菲浓度随表面活性剂淋洗液孔隙体积数增大呈现急剧增大、达到峰值后逐渐降低的趋势。淋洗结束时（菲流出浓度接近于0时）,不同浓度的Tween80和SDBS-Tween80对菲的总去除率均可达90.5%以上,而4000mg·L^-1的SDBS对菲的总去除率则仅为76.4%。此外,随着Tween80或SDBS-Tween80浓度增大,菲浓度峰值增大,开始有菲淋出时,菲浓度峰值以及菲流出浓度接近于0时对应的孔隙体积数均减小。菲浓度峰值与表面活性剂浓度呈正相关,累积孔隙体积数与表面活性剂浓度呈负相关。在淋出液累计孔隙体积数相同时,同种表面活性剂对菲的去除率与表面活性剂浓度呈正相关。     

表面活性剂、喷液量及杂草叶角对普杀特喷后附着量的影响

表面活性剂、喷液量及杂草叶角对普杀特在非敏感杂草马唐叶片上的喷后附着量有明显的独立影响和交互影响,其中表面活性剂的影响最大。供试的6种非离子型表面活性剂均因显著降低了普杀特药液的表面张力从而显著提高了其在马唐叶片上的喷后附着量,其中ScOil和Silwet—L77对其提高幅度最大;普杀特在马唐叶片上的喷后附着量随着喷液量的减少逐步增加,但在0—90°范围内随着马唐叶角的减小而减少,其由于喷液量的增大或马唐叶角的减小而引起的下降量,可通过加入非离子型表面活性剂而得到补偿,加入非离子型表面活性剂配合下午微液量(90L/ha)喷施,可望最大限度地增加普杀特在其非敏感杂草叶片上的喷后附着量,进而提高其药效,降低其使用成本和减少其在土壤中的残留。     

Effects of surfactants and simulated rainfall on the efficacy of the Engame formulation of glyphosate in johnsongrass, prickly sida and yellow nutsedge

The effects of surfactants and simulated rain were investigated on the efficacy of Engame and Roundup Ultramax formulations of glyphosate on johnsongrass ( Sorghum halepense L.), prickly sida ( Sida spinosa L.) and yellow nutsedge ( Cyperus esculentus L.). Flame surfactant provided the greatest enhancement of Engame efficacy and the effect was species-dependent. Flame enhanced the activity of Engame on johnsongrass and yellow nutsedge but not on prickly sida. Engame and Engame plus Flame were more active than Roundup Ultramax on a glyphosate acid-equivalent basis on johnsongrass without rain, and on yellow nutsedge with or without rain. The Engame and Roundup Ultramax activities on johnsongrass were similar with rain, and rain occurring between five and 30 min after treatment diminished their activities to < 38% of the control. With the addition of Flame surfactant, Engame activity on johnsongrass increased, such that 50% and 80% of the control were realized, even with rain occurring between five and 15 min after treatment, respectively. Engame and Roundup Ultramax provided better control of prickly sida than of johnsongrass following a rain event. The addition of Flame surfactant to Engame did not enhance the activity on prickly sida. Yellow nutsedge control with Engame and Engame plus Flame was greater than with Roundup Ultramax and rain had little effect on control regardless of the length of the rain-free period. These results demonstrated that the activities of Engame, Engame plus Flame and Roundup Ultramax were species-dependent and surfactant-dependent.     

双氰胺和表面活性剂添加对沼液氮素形态变化的影响

为探究双氰胺和表面活性剂添加到沼液中对其氮素形态和含量的影响,通过室内模拟试验,设置单施沼液（对照）、沼液+8%双氰胺（DCD）、沼液+16% DCD、沼液+表面活性剂、沼液+8% DCD+表面活性剂、沼液+16% DCD+表面活性剂,共6个处理,在静置10、30 min和1、3、10、24、48 h时测定沼液中总氮（TN）、总凯氏氮（TKN）、铵态氮（NH₄⁺-N）、硝态氮（NO₃^--N）含量。结果表明：与对照单施沼液相比,沼液中添加8% DCD和16% DCD后,NH₄⁺-N浓度增加了0.74%~8.96%,TKN浓度增加了24.67~59.70 mg·L^-1,NO₃^--N浓度增加了13.42~145.88倍,且NH₄⁺-N、TKN、NO₃^--N浓度与DCD添加量呈正相关。表面活性剂添加对沼液氮素形态和浓度没有显著影响。研究结果可为提高抑制剂抑制效果和科学施用抑制剂提供数据支撑。     

除草剂单用与混用对土壤微生物活性的影响

在实验室条件下，通过观测投加农药土壤中的细菌、真菌数和土壤呼吸强度的变化，研究了灭草松、莠去津、灭草松 莠去津及灭草松 莠去津 表面活性剂对土壤微生物活性的影响。结果表明，莠去津、灭草松在10倍推荐用量下会使土壤细菌数略有减小，真菌数略有增加，细菌／真菌数之比减小；莠去津 灭草松与他们单用时对土壤呼吸的影响无显著差别，但添加表面活性剂后，土壤呼吸增强且持续时间延长。     

DDTs污染农田土壤的强化微生物修复研究

为了提高微生物对DDTs污染土壤的修复效率,利用混合菌[球形节杆菌(Arthrobacter globiformis)和甲基营养型芽孢杆菌(Bacillus methylotrophicus)]对沈阳市沈北新区设施农业DDTs污染土壤进行现场修复实验,研究定期添加血粉(3X)和阴-非离子混合表面活性剂SDBS-Tween 80(3H)对混合菌修复DDTs污染土壤的强化效果,分析修复过程对DDT同分异构体及初级代谢产物的影响。结果表明:接种混合菌可有效降低土壤中DDTs的残留,连续3次接种的修复效果(3PN-1)比1次(PN-1)好,90 d后DDTs降解率可达50.5%,比对照组提高了45.9%。在此基础上,添加血粉和SDBS-Tween 80均可显著降低土壤中DDTs的残留,其中SDBS-Tween 80的处理效果较好,DDTs降解率最高达到63.2%,比单独接种混合菌处理提高了12.8%。DDT同分异构体及初级代谢产物分析表明,SDBS-Tween 80强化修复对生态毒性较强的p,p′-DDE降解率达到了62.4%,有效降低了修复后的生态风险。因此,SDBS-Tween 80强化混合菌处理可以作为DDTs污染土壤微生物修复的适宜措施。     

Mobilities of Organic Compounds in Reconstituted Cuticular Wax of Barley Leaves: Effects of Monodisperse Alcohol Ethoxylates on Diffusion of Pentachlorophenol and Tetracosanoic Acid

Effects of monodisperse alcohol ethoxylates on mobilities of ¹⁴C-labelled pentachlorophenol (PCP) and tetracosanoic acid (C₂₄AC) in reconstituted cuticular wax of barley leaves were measured. Depending on the respective alcohol ethoxylate investigated, the diffusion coefficient (D) of PCP in barley wax was increased by factors ranging from 3·3 to 19·6, whereas D of C₂₄AC, was increased by factors varying between 22 and 315. In order to analyse the relationship between the concentration of surfactants in the wax and their effects on D, the amounts of alcohol ethoxylates dissolved in the wax at equilibrium with external concentrations well above the critical micelle concentration (CMC) were determined. Wax/water partition coefficients (K_ww) of the alcohol ethoxylates were about one order of magnitude lower than cuticle/water partition coefficients (K_cw), which is a consequence of the semi-crystalline structure of the wax compared with amorphous cutin. Correlations between effects on D and maximum amounts of alcohol ethoxylates dissolved in the wax were obtained indicating an unspecific wax/surfactant interaction. This was solely dependent on the amount of surfactant sorbed to the wax, leading to increased mobilities of pesticides in the wax. Applying ESR-spectroscopy, which gave an insight into the molecular structure of the wax, supported this interpretation of an unspecific plasticising effect of the alcohol ethoxylates on the molecular structure of the wax. The results obtained in this study are in good accordance with the results obtained in a recent study investigating the effects of the same group of alcohol ethoxylates on mobilities of pesticides in isolated, but intact, cuticular membranes of Citrus. This demonstrates that the investigation of isolated and subsequently reconstituted cuticular wax is a useful model system analysing the mechanisms of the surfactant interaction with the transport-limiting barrier of plant cuticles.