离子液体[C_2mim][Val]对小麦幼苗生长及生理特性的影响

采用实验室营养液水培方法,主要研究了离子液体1-甲基-3-乙基-咪唑缬氨酸盐（[C2mim][Val]）对小麦幼苗生长及叶片保护酶活性的影响。结果表明,就小麦种子发芽这一生态毒理指标而言,[C2mim][Val]浓度为200～500mg·L-1时其发芽率显著降低;从生长角度来看,小麦幼苗对100～200mg·L-1浓度的处理不敏感,生长指标没有显著变化,在300～500mg·L-1处理下,小麦幼苗地上部及地下部生物量、株高、根长发生显著变化,均受到明显的抑制,且抑制效应具有典型的剂量依赖型特点。不同浓度[C2mim][Val]处理均致使超氧化物歧化酶（SOD）活性下降,且浓度越高抑制作用越明显;100～200mg·L-1浓度处理在8～13d过氧化物酶（POD）活性高于对照,后期不显著,300～500mg·L-1浓度胁迫后期（18d）,其活性均发生显著的变化,分别为对照的84%、83%、74%,并造成膜脂过氧化产物丙二醛（MDA）含量升高,表明300～500mg·L-1浓度胁迫使植物生长受到抑制。[C2mim][Val]的亲水性及亲脂特性可能是其对植物存在潜在毒性的2个主要原因。     

Molecular characterization of tetracycline- and quinolone-resistant Aeromonas salmonicida isolated in Korea

The antibiotic resistance of 16 Aeromonas (A.) salmonicida strains isolated from diseased fish and environmental samples in Korea from 2006 to 2009 were investigated in this study. Tetracycline or quinolone resistance was observed in eight and 16 of the isolates, respectively, based on the measured minimal inhibitory concentrations. Among the tetracycline-resistant strains, seven of the isolates harbored tetA gene and one isolate harbored tetE gene. Additionally, quinolone-resistance determining regions (QRDRs) consisting of the gyrA and parC genes were amplified and sequenced. Among the quinolone-resistant A. salmonicida strains, 15 harbored point mutations in the gyrA codon 83 which were responsible for the corresponding amino acid substitutions of Ser⁸³→Arg⁸³ or Ser⁸³→Asn⁸³. We detected no point mutations in other QRDRs, such as gyrA codons 87 and 92, and parC codons 80 and 84. Genetic similarity was assessed via pulsed-field gel electrophoresis, and the results indicated high clonality among the Korean antibiotic-resistant strains of A. salmonicida.     

30种中草药植物对尿素水解和硝化作用的抑制效果研究

采用室内培养实验,分别研究了21科30种中草药的植物浸提液对3种土壤中尿素水解和硝化作用的抑制效果。结果表明,中草药植物浸提液能够对尿素水解起抑制作用的有23种,其中8种的抑制效果优于脲酶抑制剂氢醌(HQ);浸提液能够抑制硝化作用的植物有25种,其中3种的硝化抑制效果优于双氰胺(DCD);唇形科植物夏枯草(Prunella vulgaris L.)和忍冬科植物金银花(Lonicera japonica Thunb.)既能有效抑制尿素水解,又能有效减缓NH+4的硝化,是尿基氮肥增效剂的最佳选择。研究还表明,夏枯草和金银花粉末在培养后的24~36 h脲酶抑制率最高,在培养后的14~21 d硝化抑制率最高,且抑制效果随粉末用量的增加而增强。     

酸马奶酒中微生物的分离鉴定及抗菌特性的研究

从内蒙古锡盟不同地区采集15份酸马奶酒样品,经分离纯化、归属种鉴定,并单菌发酵液经调pH值、蒸发酒精、浓缩后,对李斯特杆菌、金黄色葡萄球菌、大肠杆菌进行抑菌研究。结果表明,酸马奶酒是由多种乳酸菌和酵母菌共同发酵的乳饮料。其中乳酸菌中有球菌5个属,杆菌6个属,酵母菌6个属。乳酸菌中有9株乳球菌和12株乳杆菌对李斯特杆菌有抑制作用,对大肠杆菌和金黄色葡萄球菌无抑制作用。酵母菌中有4株对大肠杆菌有抑菌作用,其中有2株同时对金黄色葡萄球菌有抑制作用,对李斯特杆菌无抑制作用     

细胞外环境中分化抑制物对动物胚胎干细胞克隆率的影响

介绍了饲养层、条件培养基、分化抑制因子对哺乳动物胚胎干细胞分离与克隆的影响，并探讨了白血病抑制因子影响胚胎干细胞克隆的机理。     

Further data to the aetiology, pathogenesis and therapy of infectious bovine keratoconjunctivitis

Out of a total of 224 bovine eye secretions, 126 Moraxella bovis and 64 Neisseria ovis strains were isolated. The pathogenesis and histological lesions caused by Neisseria ovis have been studied on the eyes of three calves naturally affected with IBK, using electron microscopy.

Neisseria ovis caused in 1–12 weeks old calves acute, transient and mostly benign serous conjunctivitis with only slight affection of the cornea. More rarely erosions and even ulceration of the cornea have been observed.

Moraxella bovis and Neisseria ovis strains proved nearly unanimously sensitive in vitro to chloramphenicol, neomycin, oxytetracyclin, nitrofurantoin, erythromycin and cefoperazone. Other antibiotics and chemotherapeutics inhibited the growth of these agents only partly or were ineffective.

Experimental therapy has been carried out using a single i.m. injection of Terramycin/LA inj. (Pfizer) in a dose of 20 mg/kg body mass, repeated if necessary after 72–96 h. This formulation proved more effective and practical than treatments used earlier.     

Epitope identification and <Emphasis Type="Italic">in silico</Emphasis> prediction of the specificity of antibodies binding to the coat proteins of <Emphasis Type="Italic">Potato Virus Y</Emphasis> strains

A phage library containing 2.7 × 10⁹ randomly expressed peptides was used to determine the epitopes of three monoclonal antibodies that bind to the coat protein of potato virus Y. Construction of the consensus sequences for the peptides obtained after three selection rounds indicated that each antibody recognized a different epitope located within the first 50 N-terminal amino acids of the coat protein. The location of the epitopes was confirmed by heterologous expression of the N-terminal part of the coat protein in Escherichia coli, and, subsequently, by performing an immunological test with the three antibodies. The accuracy of the phage library was demonstrated by predicting in silico the cross-reactivity of the three antibodies with other potyvirus family members. ELISA and in silico predictions revealed the same results in almost every case. The potential of peptide phage libraries to optimize the use of antibodies in plant virology is discussed.     

牡丹叶及其不同溶剂提取物对生菜等幼苗生长的抑制效应

为了进一步明确牡丹叶及其不同溶剂提取物的化感活性大小,于室内采用琼脂混粉法测定了牡丹叶粉末在不同浓度下对生菜、小麦、黄瓜、稗、夏至草、播娘蒿和独行菜等7种受体植物幼苗生长的影响.结果表明,虽然在低浓度下牡丹叶粉末对各受体植物幼苗生长的影响差异较大,但在高浓度时均表现出了较高的抑制作用,且对胚根(或种子根)的抑制效果明显高于对胚轴或胚芽鞘的抑制.计算对各受体植物胚根或种子根、胚轴或胚芽鞘的有效中浓度(EC50),生菜为0.93～5.25 g/L、小麦为1.20 ～4.65 g/L)、黄瓜为3.58～＞10.0 g/L、稗为0.64～3.36 g/L、夏至草为1.09～5.27 g/L、播娘蒿为1.02 ～9.65 g/L、独行菜为0.79 ～6.84 g/L,以稗的敏感性最高,黄瓜最低.继而探索了牡丹叶乙醇、甲醇和蒸馏水3种溶剂提取物对生菜幼苗生长的抑制效果,发现乙醇提取物的活性最高,提取浓度以80％ (V/V)为宜.     

纳他霉素纳米乳的制备及其体外抑菌效果研究

【目的】制备纳他霉素纳米乳(NATA-NE),测定其对白色念珠菌（Candida albicans）、青霉菌（Penicillium）和酿酒酵母菌（Saccharomyces cerevisiae）的最小抑菌浓度（MIC）和最小杀菌浓度（MFC）,以指导临床合理用药。【方法】综合纳米乳和纳他霉素的优势,将纳他霉素制成水包油型NATA-NE,以酮康唑和特比萘芬作为阳性药物对照,根据美国临床实验室标准化委员会（NCCLS）制定的真菌体外药敏试验方法M27A和M-38P,测定药物对3种受试菌株的MIC,并研究了NATA-NE的杀菌效果。【结果】NATA-NE对青霉菌、白色念珠菌和酿酒酵母菌的MIC值为1,0.5,0.5 μg/mL;NATA原料药、酮康唑和特比萘芬对上述3种菌的MIC值分别为2,1,1 μg/mL;4,8,8 μg/mL和1,8,16 μg/mL,NATA-NE的MIC值均小于或等于其他3种药物。3种菌在2 μg/mL NATANE的作用下1.5 h后,均未见生长;NATA原料药则需要4 μg/mL、2 h才能达到同样效果,而酮康唑和特比萘芬分别需要16 μg/mL、4 h和32 μg/mL、4 h才能达到同样效果。【结论】临床使用NATA-NE治疗动物真菌病时,可适当降低给药剂量和用药次数,以降低成本和对动物不可预期的副作用。     

大蒜废弃物对农作物病原菌的抑制效果

我国大蒜废弃物资源丰富,为引导其合理化、资源化利用,测定了大蒜提取物对大豆尖孢镰刀菌(Fusarium oxysporum fsp.tracheiphilum)、油菜菌核病菌(Sclerotinia sclerotiorum(Lib.)d eBary)、大豆细菌性斑点病菌(Pseudomonas.s yringae pv.glycinea)和水稻白叶枯病菌(Xanthomonas oryzae pv.oryzae〔Ishiyama〕Dye,Xoo)4种植物病原菌的抑制作用,并通过大蒜提取物、大蒜渣、大蒜肥对土壤中大豆尖孢镰刀菌的抑制试验,测定了其在土壤中对土传病原菌的抑制效果。结果表明,高浓度的大蒜提取物对这4种植物病原菌有抑制作用,随着提取物浓度的升高,抑菌效果也更为明显。质量浓度为500mg.mL-1时对大豆尖孢镰刀菌、大豆细菌性斑点病菌和水稻白叶枯病菌的抑菌效果最好。培养基中提取物浓度达100mg.mL-1时对两种真菌的抑制达100%。同时,含大蒜提取物0.05mL.g-1、大蒜渣5%或大蒜肥25%的土壤能抑制土传病原菌大豆尖孢镰刀菌在土壤中的定殖。