富碳条件下蛋白核小球藻的生长及其对油脂的积累

[目的]研究富碳条件下蛋白核小球藻的生长及其对油脂的积累.[方法]通过外加乙酸钠的方法形成小球藻生长的富碳环境,研究小球藻在富碳条件下的生长及其对油脂的积累.[结果]外加一定量的乙酸钠能明显促进蛋白核小球藻的生长(P＜0.01),显著提高小球藻中的油脂含量(P＜0.01).[结论]该研究可为小球藻的应用开发及富营养化废水的净化利用提供参考.     

Effect of chlorimuron-ethyl on Bradyrhizobium japonicum and its symbiosis with soybean

Possible side-effects of the acetolactate synthase (ALS)-inhibiting herbicide chlorimuron-ethyl on Bradyrhizobium japonicum (Kirchner & Jordan) in pure culture and on inoculated soybean plants growing under controlled conditions were investigated. Growth of B japonicum strain E109 was not affected by this herbicide even when exposed to concentrations 150 times higher than recommended field doses. However, nodulation of soybean plants treated 5 days after emergence with chlorimuron-ethyl at standard application rates was impaired: a 38% decrease in the number of nodules per plant was observed four weeks after treatment. Despite nodule number decrease, no changes in shoot nitrogen content could be detected. Total fresh biomass was diminished by 25% in herbicide-treated plants. Leghemoglobin content in nodules did not vary; nevertheless total nodule protein was diminished by 40% in the herbicide-treated group. ALS activity in different soybean tissues and their relative sensitivity to chlorimuron-ethyl were also investigated. Roots and bacteroids had the greatest specific ALS activities. On a fresh weight basis, the bacteroid fraction displayed the highest ALS activity and was also the most tolerant to in vitro chlorimuron addition: 72% of its activity was retained after including 10 microM chlorimuron-ethyl in the reaction mixture. These results indicate that standard application rates of chlorimuron-ethyl will have limited incidence on B japonicum survival, and effects on nodulation may have little long-term consequences on soybean nitrogen fixation potential. The differences found among soybean tissues not only in intrinsic ALS activity but also in their relative sensitivity to this herbicide suggests that, in leguminous plants living in symbiosis with rhizobia, nodules may contribute to an enhanced tolerance to ALS inhibitors.     

松根炭制维尼纶载体活性炭的研究

作为维尼纶合成中的载体活性炭，其强度和孔径分布要求十分严格，所以需要使用椰壳活性炭。本研究的目的就是制造一种活性炭来代替它。实验证明，松根炭制成的活性炭可以作为载体活性炭。其关键是粘结剂、辅助试剂和活化条件的选择。     

Effects of mutations in Drosophila nicotinic acetylcholine receptor subunits on sensitivity to insecticides targeting nicotinic acetylcholine receptors

Several strains of Drosophila melanogaster possess mutant alleles in nicotinic acetylcholine receptor (nAChR) subunits, Dα1 and Dβ2 that confer resistance to neonicotinoids such as imidacloprid and nitenpyram, and Dα6, that confers resistance to spinosyns. These mutant strains were bioassayed with a selected set of nAChR active insecticides including neonicotinoids, spinosad, and sulfoxaflor, a new sulfoximine insecticide. All of the neonicotinoids examined, except dinotefuran showed reduced insecticidal efficacy on larvae of the Dα1 mutant, suggesting that this subunit may be important in the action of these insecticides. All of the neonicotinoids, including dinotefuran, showed reduced insecticidal efficacy on larvae possessing the Dβ2 mutation. A similar pattern of broad neonicotinoid resistance to that of Dβ2 alone was also observed for larvae with both the mutations (Dα1 + Dβ2). The Dβ2 mutation exhibited a lower level of cross-resistance to sulfoxaflor (<3-fold) than to any of the neonicotinoids (>13-fold). In contrast, there was no cross-resistance for any of the neonicotinoids or sulfoxaflor in adult flies with the Dα6 mutation, which confers high levels of resistance to spinosad. Thus in the D. melanogaster strains studied, target site resistance observed for the neonicotinoids and the spinosyns does not translate directly to resistance towards sulfoxaflor.     

氯嘧磺隆降解菌降解效果研究

近年来除草剂在土壤中持续积累,对后茬敏感作物造成严重药害,导致作物减产甚至绝产,氯嘧磺隆就是其中一种广谱、超高效和残留期较长的磺酰脲类除草剂。该试验通过氯嘧磺隆降解菌的筛选并作用于受氯嘧磺隆药害的萌芽水稻种子,利用测定筛选出的氯嘧磺隆降解菌对氯嘧碘隆的降解作用来研究其对氯嘧磺隆的降解作用效果。结果表明:所筛选的氯嘧磺隆降解菌对氯嘧磺隆有一定的降解作用。在同一菌不同浓度下,氯嘧磺隆5μg.kg-1时降解效果最好。在同一氯嘧磺隆水平下,降解菌稀释倍数为100倍时降解效果最佳。     

花椒愈伤组织EMS诱变及变异研究

用EMS处理花椒韧皮部及叶片来源的愈伤组织,确定愈伤组织的适宜来源和EMS处理花椒愈伤组织LD50,在不同EMS浓度的半致死剂量下处理愈伤组织,组培获得花椒诱变植株。结果表明,EMS诱变花椒愈伤组织的LD50为0.3%EMS处理6h,0.5%EMS处理4h,0.7%EMS处理2h。诱变后愈伤组织经增殖和分化形成完整植株。通过对比再生植株形态学差异,筛选出变异植株340株。     

低取代度糯玉米淀粉醋酸酯的制备

以糯玉米淀粉为原料,醋酸酐为乙酰化试剂,氢氧化钠为催化荆,硫酸钠为膨胀抑制荆,制备了低取代度糯玉米淀粉醋酸酯。考察了醋酸酐用量、膨胀抑制刺用量、pH值、反应温度、反应时间等因素对糯玉米淀粉醋酸酯乙酰基含量和反应效率的影响。试验结果表明,醋酸酐用量、硫酸钠用量、pH值、反应温度和反应时间对糯玉米淀粉醋酸酯的取代度有影响。通过试验得到制备低取代度糯玉米淀粉醋酸酯的较佳工艺条件为：pH值9．0,反应温度30℃,反应时间60min,硫酸钠用量2％（以淀粉干基质量计）。     

Actinomyces bowdenii ulcerative keratitis in a dog

A 5‐year‐old spayed female diabetic mixed‐breed dog underwent phacoemulsification and intraocular lens implantation to correct bilateral hypermature cataracts. Two months postsurgery, the patient presented with ulcerative keratitis and multifocal stromal abscessation OD, which was controlled, but never resolved, with topical fluoroquinolone therapy. The patient re‐presented 2 months later with a new, raised, white gritty corneal opacity associated with hyperemia, chemosis, and blepharospasm OD. Cytology of the right cornea revealed filamentous bacteria, suggestive of Actinomyces spp. Actinomyces bowdenii was subsequently isolated in pure culture and identified via 16s rDNA sequencing. Actinomyces bowdenii has never before been described as a cause of ocular infection. An immunosuppressed corneal environment likely contributed to this opportunistic Actinomycosis. The infection was not controlled with fluoroquinolone therapy, and the isolate, in vitro, was resistant to three fluoroquinolones (ciprofloxacin, ofloxacin, and levofloxacin), which also has not been previously reported for this species of Actinomyces. A superficial keratectomy with conjunctival graft was employed to successfully manage the infection.     

乙酯类挥发物及诱剂对沙棘绕实蝇的引诱效果

【目的】沙棘绕实蝇Rhagoletis batava Hering是近年来在新疆阿勒泰地区新发现的沙棘果实重要害虫,研究沙棘绕实蝇监测和绿色防控的新途径。【方法】在田间悬挂黄板组合不同乙酯类挥发物及诱剂对沙棘绕实蝇进行诱捕试验。以黄板、三角形诱捕器、实蝇专用蘑菇形诱捕器、白色粘虫板作为载体测试其对沙棘绕实蝇的引诱剂效果。【结果】经单因素方差分析,黄板作为载体,与其他处理相比诱捕量具有极显著差异(P ＜ 0.01),平均诱捕量为18.33头/张;悬挂密度以每667 m²悬挂40张诱捕效果最佳,蛀果率为8.27%。沙棘绕实蝇引诱剂诱集数量主要集中在前4 d。不同乙酯类挥发物及诱剂对沙棘绕实蝇成虫诱捕效果为顺序为沙棘绕实蝇引诱剂＞RDKS＞月桂酸乙酯=十四酸乙酯=棕榈酸乙酯=桔小实蝇引诱剂。【结论】沙棘绕实蝇引诱剂组合黄板对沙棘绕实蝇成虫具有极好的引诱效果,并筛选出一种挥发物RDKS对沙棘绕实蝇两性成虫均有较好的引诱效果,可作为沙棘绕实蝇引诱剂的成分之一,这两种引诱剂结合黄板可作为沙棘绕实蝇监测和防治的有效手段之一。     

恩施产区湖北贝母乙酸乙酯组分挥发性成分与抗菌活性研究

为了研究恩施产区湖北贝母乙酸乙酯组分的抗菌活性和挥发性成分,以恩施产区湖北贝母乙酸乙酯组分为研究对象,运用滤纸片法测试对11株供试菌的抑菌活性;采用微量肉汤稀释法测定对供试菌的MIC值;运用GC-MS鉴定挥发性成分;运用气相色谱外标法测定贝母素乙含量。研究结果显示:湖北贝母乙酸乙酯组分对苏云金芽孢杆菌、溶藻弧菌、鲍曼不动杆菌有中度敏感抑制活性,其MIC值分别为2.37、5.93、11.86 mg·mL^-1;湖北贝母乙酸乙酯组分的抑菌活性与贝母素乙的抑菌活性存在显著性差异,推测贝母素乙不是湖北贝母乙酸乙酯组分中主要发挥抑菌活性的成分;从乙酸乙酯组分中共鉴定出16个挥发性代谢产物,主要成分为脂肪烃(4.55%)、脂肪酸(24.07%)、含氮生物碱(23.02%);湖北贝母乙酸乙酯组分中贝母素乙的含量为(16.19±0.16) mg·g^-1,加标回收率为96.58%,相对标准偏差为3.98%。湖北贝母乙酸乙酯组分的优良抑菌活性和抑菌广谱性,为开发优质植物来源的新型天然抗生素提供了重要参考。