野艾蒿挥发油对HeLa癌细胞形态与结构的影响

采用MTT法检测细胞活力,用倒置显微镜、荧光显微镜和扫描电子显微镜观察细胞形态与结构的变化,用激光共聚焦显微镜观察细胞微管的分布,从而研究了野艾蒿挥发油对HeLa人宫颈癌细胞形态与结构的影响。结果表明:(1)野艾蒿挥发油对HeLa癌细胞的增殖有明显的抑制作用,呈剂量和时间依赖性。(2)野艾蒿挥发油处理HeLa癌细胞24h后,100、200μg/mL实验组细胞体积缩小,核染色质凝集、微绒毛消失、细胞表面有泡状突起,微管解聚,呈现典型的凋亡特征;400μg/mL实验组细胞膜破裂、胞浆内含物外泄,呈明显的坏死特征。(3)野艾蒿挥发油具有抑制HeLa癌细胞增殖的作用,低、中浓度的野艾蒿挥发油诱导细胞凋亡,而高浓度的野艾蒿挥发油引起细胞坏死。     

野艾蒿化学成分和药理作用研究进展

野艾蒿(Artemisia lavandulifolia)为我国传统中药,属于菊科(Compositae)植物,广泛分布于我国东北、华北等地区,具有巨大的开发潜力和丰富的资源。近年来,从野艾蒿中成功分离出许多具有新颖结构和显著药理活性的化合物,相关研究取得了显著进展。该文对野艾蒿的主要化学成分、提取分离方法、结构鉴定技术以及药理作用等方面进行了综合归纳总结。野艾蒿主要化学成分包括79个萜类化合物和挥发油、17个黄酮类化合物、6个木脂素类化合物和2个咖啡酸类化合物,还富含微量元素、维生素和氨基酸。野艾蒿化学成分具有显著的抗肿瘤、抗炎、抗氧化、降血脂、抑菌和杀虫等药理作用,但相关机制仍需进一步阐明。在此基础上,该文侧重关注野艾蒿的化学成分和药理作用,以挖掘更多具有临床价值的成分和作用机制。此外,该文也指出了野艾蒿在药用价值和现有研究方面存在的不足之处,并提出了未来的研究方向和建议,以促进野艾蒿的合理药用开发和综合利用,为今后相关研究提供参考和指导。     

艾蒿提取物对菜青虫的生物活性

采用微波辅助提取、溶剂浸提 ,以正己烷、乙醇、正己烷 +乙醇 (体积比 1∶1 )为溶剂从艾蒿ArtemisiaargyiL啨ｖｌ.etVant茎叶得到了提取物。另外 ,还用水蒸气蒸馏法获得了精油。生物活性试验表明 ,它们对菜青虫PierisrapaeL .具有较强的拒食活性和一定的触杀活性。其中 ,正己烷为溶剂的微波辅助提取物的拒食活性和触杀活性最强。     

金鱼藻对铜绿微囊藻生长的抑制作用研究

研究了金鱼藻对铜绿微囊藻生长的抑制效应。结果表明：高浓度的金鱼藻种植水抽滤液和植株研磨水提液对铜绿微囊藻的生长有极明显的抑制作用;低浓度则几乎没有抑制作用。同一浓度下,金鱼藻植株研磨液的抑制效应比种植水更为明显,抑制效应持续时间也更长。20℃培养下的金鱼藻,其植株研磨液的抑制效应最明显。高浓度的嫩枝嫩叶部位的金鱼藻植株研磨液对铜绿微囊藻的生长有更明显的抑制作用,低浓度的老茎老叶部位的金鱼藻植株研磨液对其生长则表现出一定的促进作用。     

抑藻菌株Bacillus sp. hsn03分离鉴定及其对铜绿微囊藻的抑制效果与特征

【背景】蓝藻常形成水华,严重破坏水生环境及威胁水生生物。微生物能够专一性地抑制蓝藻的生长,从而可以被用于蓝藻水华的控制。【目的】分离筛选一株对有害水华藻——铜绿微囊藻(Microcystisaeruginosa)7806有高效抑藻能力的菌株,对其进行生理生化和分子鉴定,并研究其抑藻效果与特征。【方法】通过API试剂条确定其生理生化特征,对细菌的16SrRNA基因进行测序并构建系统进化树,通过探究细菌菌体、上清、发酵液的抑藻效果确定该菌的抑藻方式,通过测定不同温度、pH、蛋白酶K、有机溶剂萃取和透析条件下的抑藻效果及傅里叶红外光谱来确定胞外抑藻物质的性质。【结果】菌株hsn03与芽孢杆菌属(Bacillus sp.)的Bacillus sonorensis NBRC101234有最高相似性,达99.59%;通过分泌胞外抑藻物质对铜绿微囊藻生长表现出抑制效果,且最佳抑藻添加量为7.0%(体积比);胞外抑藻物质为一类分子量大于500 Da且小于1 kD,耐高温,耐酸碱,含有叁键和累积双键,非蛋白、多糖类的小分子物质。【结论】抑藻菌株的挖掘与鉴定对于丰富有害藻华藻的抑藻菌质资源有非常大的促进作用,通过对抑藻方式、效果和特征的研究为进一步将抑藻菌应用于铜绿微囊藻的治理奠定基础。     

三种柑橘类果皮提取物对铜绿微囊藻生长的影响

通过分析测定生物量、叶绿素a含量以及叶绿素荧光参数,研究了3种柑橘类果皮甲醇提取液对铜绿微囊藻生长的影响。结果表明,3种提取液都能有效抑制铜绿微囊藻的生长、叶绿素a合成与光合系统Ⅱ（PSⅡ）活性,并且抑制效果随着作用浓度增加而增强。3种提取液抑制作用强弱的顺序为：蜜橘〉西柚〉脐橙。当蜜橘皮提取液浓度大于1.10g/L时,抑藻效果显著（P〈0.05）,培养9d后对铜绿微囊藻生长的抑制率达到86.4%,且在实验期间抑制作用没有减弱。当脐橙皮与西柚皮提取液的浓度大于3.31g/L时,抑藻效果显著（P〈0.05）,但培养5d后抑制作用开始减弱。据此推测,3种柑橘类果皮提取液中存在一类或几类物质,能够抑制铜绿微囊藻的叶绿素a合成,降低PSⅡ活性,从而降低其光合作用效率,导致铜绿微囊藻的生长受到抑制。且这类物质能自然降解,随着作用时间的延长,其抑藻效果也逐渐消失。     

植物化感作用研究进展——以抑制铜绿微囊藻生长为例

水体富营养化引起的藻华问题依旧是当前世界共同面对的难题,其中植物释放化感物质应对藻华是高效低耗的手段,受到国内外研究者的青睐.综述了不同水生植物和陆生植物对铜绿微囊藻(Microcystis aeruginosa)的生长影响,总结了抑制铜绿微囊藻的植物种类、研究方法、化感作用效果以及化感作用机理,归纳了各种植物的化感作...     

凤眼莲浸出液对东海原甲藻生长的抑制作用

研究了凤眼莲浸出液对赤潮藻东海原甲藻生长的影响。浸出液浓度以单位体积溶液中所含凤眼莲鲜重表示。结果显示,在浸出液浓度大于2g·L^-1时,活体凤眼莲浸出液和干凤眼莲浸出液对东海原甲藻的生长都有明显的抑制作用。在浸出液浓度达到8g·L^-1时,活体凤眼莲浸出液和干凤眼莲浸出液对东海原甲藻都具有杀灭作用,东海原甲藻全部死亡出现的时间分别为培养后的第4t和第5t。经121℃高温处理20min后的活体凤眼莲浸出液对东海原甲藻的抑制作用仍然存在,抑制作用并没有显著减弱。研究结果表明凤眼莲的抑藻物质具有用来控制赤潮生物东海原甲藻的潜在价值。     

枯草芽孢杆菌fmb60菌株非核糖体肽类化合物对铜绿微囊藻生长的抑制作用

铜绿微囊藻是一种分布广泛的水华微藻,可对人类健康和生态环境造成严重危害,而枯草芽孢杆菌作为一种生防微生物可通过非核糖体肽合成酶合成多种生物活性物质.因此,枯草芽孢杆菌fmb60非核糖体肽(Non-ribosomal peptide,NRP)类产物对铜绿微囊藻生长抑制作用的研究在水华治理方面具有重要的意义.利用基因组挖掘...     

大漂提取物抑制铜绿微囊藻的试验研究

为了确定高效脱氮除磷的水生漂浮植物大漂的主要化感活性物质, 本文通过乙醇超声波提取获得大漂的化感粗提物, 利用溶剂萃取法从粗提物中分离得到4种能抑制铜绿微囊藻(FACHB-911)生长的化感萃取物,当其浓度均为0.1 g/L时共培养5d后抑藻率分别为40%、69%、40%、35%。将抑藻率最高的化感萃取物通过酸性氧化铝柱层析法进一步分离纯化, 分离得到4组抑藻作用较弱的(5d后抑藻率分别为12%、11%、33%、41%)和1组抑藻作用较强的化感层析流分(5d后抑藻率高达80%)。将抑藻作用最强的化感层析流分通过气相色谱-质谱联用(GC-MS)方法进行成分检测, 发现大漂提取物中含有对甲苯磺酸甲酯、硬脂酸酰胺两种具有化感潜力的化合物。     

艾的挥发性物质化感作用研究

艾是我国常见的菊科多年生杂草,也是草本药用植物。研究表明,艾的茎叶在密闭系统中产生的挥发性物质对稗草、三叶鬼针草和青葙的幼苗生长有显著抑制作用。稗草的根长、苗高和鲜重分别比对照减少43.3%、30.8%和35.7%,三叶鬼针草分别比对照减少29.2%、30.0%和29.5%,青葙分别比对照减少26.3%、15.4%和27.9%。水蒸汽蒸馏法所得的挥发油对稗草、三叶鬼针草和青葙的幼苗生长也有显著抑制作用。稗草的根长、苗高和鲜重分别比对照减少71.5%、54.8%和30.5%,三叶鬼针草根长、苗高和鲜重分别比对照减少40.9%、49.2%和39.1%,青葙根长、苗高和鲜重分别比对照减少78.8%、29.1%和34.1%。结果显示,艾挥发物对邻近植物可能产生化感作用。     

铜污染对野艾蒿生长发育的胁迫及伤害

通过水培试验,研究了Cu污染对野艾蒿生长发育的胁迫伤害.试验设Cu浓度为2.5、5、10、20和40 mg·L^-1,以植物生长指标及生理指标为测试指标,试验周期14 d.结果表明, 低浓度Cu处理(2.5 mg·L^-1)对野艾蒿生长有促进作用,但随Cu浓度增高(5～40 mg·LL^-1)则产生抑制效应.各项生长指标均与Cu浓度呈极显著负相关,叶绿素含量也产生类似变化.几种光合色素对Cu的敏感性顺序为：叶绿素a＞叶绿素a+b＞叶绿素b＞类胡萝卜素.叶细胞膜渗透性、O₂^-·产生速率和丙二醛(MDA)含量在Cu浓度为2.5 mg·L^-1时较对照略有下降,再随Cu浓度升高而不断上升.POD、SOD和CAT活性随Cu浓度升高先上升,后下降,与根系耐性指数变化一致.在Cu浓度不超过20 mg·L^-1情况下,根系耐性指数＞0.5;Cu浓度为40 mg·L^-1时,根系耐性指数降低为0.36.     

Ecological responses to nutrients in streams and rivers of the Colorado mountains and foothills

1. Abundance and composition of periphyton and benthic macroinvertebrates were treated as potential nutrient response variables for 74 streams in montane Colorado. The streams ranged from unenriched to mildly enriched with nutrients (N, P). 2. The study showed no meaningful relationship between periphyton biomass accumulation and concentrations of total or dissolved forms of nitrogen or phosphorus. Nutrient concentrations were also unrelated to periphyton and macroinvertebrate richness, diversity and community composition. Macroinvertebrate communities did, however, show a strong positive relationship to periphyton abundance. 3. A positive response of periphyton biomass to increasing nutrient concentrations has been well documented over large ranges of nutrient concentrations. Our study suggests that the nutrient response is suppressed by other controlling factors on the lower limb of the nutrient response curve (i.e. at low nutrient concentrations); a quantitatively significant response occurs only in excess of a threshold beyond which nutrients become dominant over other controlling factors. This interpretation of the results is consistent with published meta‐analyses showing lack of nutrient response for a high proportion of experimentally enriched periphyton communities, and division of responses between N and P for communities that do show growth in response to enrichment. 4. Grazing probably is not the key controlling variable for periphyton in Colorado mountain streams, given that the highest chlorophyll concentrations are associated with the highest abundances of macroinvertebrates. Modelling indicates that the initial amount of periphyton biomass at the start of the growing season, in conjunction with elevation‐related length of the growing season and water temperature, explains most of the variation in periphyton accumulation among these streams, but there is a yet unexplained suppression of periphyton growth rates across all elevations.     

Effects of nitrogen,phosphorus and carbon enrichment on planktonic and periphytic algae in a softwater,oligotrophic lake in Florida,USA

The objective of this study was to investigate nutrient limitation of algal abundance in Anderson-Cue Lake, a softwater clear oligotrophic lake in north-central Florida. Nutrient diffusing clay pots and cylindrical enclosures were used in the field to test effects of different combinations of nitrogen, phosphorus, silica, and carbon on algal standing crop and composition of periphytic and planktonic algae, respectively. Effects of nutrient enrichment on periphytic algae were examined in two studies conducted 31 May – 8 July and 10 June – 15 July 1991. Nutrient effects on planktonic algae were examined in one study from 13 June – 1 July 1991. Planktonic and periphytic algal biovolume was significantly higher (p<0.05) when nitrogen and carbon were added in combination than with treatments without nitrogen, carbon, or nitrogen and carbon. Treatments with nitrogen and carbon combined resulted in lower algal diversity and dominance by coccoid green algae andScenedesmus. Results indicate that carbon and nitrogen can be limiting factors to algal growth in Anderson-Cue Lake and possibly other lakes of similar water quality.     

Long-term Changes in Littoral Habitats and Communities in Lake Mikolajskie (Poland)

Lake Mikolajskie is seriously affected by Mikolajki town and tourism. The amount of sewage entering the littoral zone is increasing as also is the area of the artificially transformed shore. During the past 20 years the area occupied by macrophytes has decreased markedly. The decline of Phragmites australis, changes in species composition, and reductions in biomass and in the depth-range colonized by submerged plants have been observed. Simultaneously the biomass of algae has increased markedly. Animals characteristic of polluted sites have become more abundant. Changes in animal numbers result to a great extent from changes in the availability of natural substrates. Zonation of the occurrence of organisms has been observed for years on sites directly affected by sewage—quantitatively and qualitatively poor communities are found at sewage discharge points and the richer ones at a greater distance in the zone fertilized by diluted sewage.     

北京四校园人工湖浮游藻类与富营养化特征分析

浮游藻类作为重要的生物指标已被广泛运用于各种水体的富营养化监测与评价中.论文对北京市4个校园人工湖的浮游藻类群落组成及季节变化展开调查,探讨了浮游藻类生物指标和富营养化的关系及其季节变化规律.调查期间,镜鉴得到39个属,隶属于蓝藻,绿藻和硅藻门.4个水体生物密度的季节平均值均高于500 cell·mL^-1,多样性指数普遍介于2～3之间.TN,TP和COD显示各水体都已处于富营养化状态.综合生物指标和水质指标进行聚类分析,结果显示:4个人工湖不同季节的水体可分为绿藻型,蓝,绿藻型和硅藻型三大类富营养化水体:荷花池,荷塘浮游藻类群落相似性最高,而荷塘、未名湖夏季富营养化程度最接近.