三种金属氧化物纳米颗粒的水生态毒性

参考国际经济合作与发展组织(OECD)化学品生态毒性测试标准方法,以绿藻(Scenedesmus oblignus)和大型蚤(Daphnia magna)为受试生物,研究了3种金属氧化物纳米颗粒(纳米氧化锌nZnO、纳米二氧化钛nTiO2、纳米氧化铝nAl2O3)水悬浮液的水生生态毒性.结果发现,不同的纳米颗粒具有不同的毒性:nZnO、nTiO2和nAl2O3对斜生栅藻生长的 96 h半效应浓度(EC50)值分别为1.049、15.262、>1000 mg · L-1,而对大型蚤活动抑制的 48 h EC50 值则分别为0.622、35.306 mg · L-1和114.357 mg · L-1.据此可得到3 种金属氧化物纳米颗粒水悬浮液的毒性大小顺序为:nZnO ＞nTiO2 ＞ nAl2O3.此外,不同的生物对金属氧化物纳米颗粒的敏感性也不同,除nTiO2以外,大型蚤对另外2种纳米颗粒的敏感性强于斜生栅藻.实验结果表明,人工纳米材料的生态毒性和环境效应不容忽视,应重视并深入研究此类纳米材料的毒性作用机制和影响因子,以便能对其进行更好的风险管理.     

Al2O3纳米颗粒对梨形四膜虫细胞毒性机理研究

采用模式生物梨形四膜虫为研究对象,探讨了Al2O3纳米颗粒对生物细胞的毒性。分别研究了纳米Al2O3对梨形四膜虫生长繁殖、乙酰胆碱酯酶(True choline esterase,TChE)活性、琥珀酸脱氢酶(Succinatedehydrogenase,SDH)活性以及对热激蛋白70(HSP70)和多药耐药(MDR1)基因的表达活性的影响。结果表明:Al2O3纳米颗粒对梨形四膜虫的生长繁殖具有显著的抑制作用,并延长了传代时间,减少了繁殖代数;Al2O3纳米颗粒对梨形四膜虫TChE的活力表现为中低浓度(10 mg/L与100 mg/L)激活,高浓度(500 mg/L)抑制的趋势,而对SDH的活力具有抑制作用,浓度越高作用越明显,尤其在500 mg/L浓度下抑制作用极显著(p<0.01);Al2O3纳米颗粒对梨形四膜虫HSP70及MDR1基因表达均有显著作用,HSP70表现为低浓度抑制、高浓度诱导,而MDR1表现为低浓度诱导、高浓度抑制。可知,Al2O3纳米颗粒对梨形四膜虫是具有毒性的,但是其机制还需要更进一步的研究探索以及验证。     

以叶酸偶联纳米Fe_3O_4颗粒的合成和标记肿瘤实验研究

目的:研究叶酸偶联的超顺磁Fe3O4纳米颗粒对活体肝癌标记效果和MRI成像功能。方法:以铁盐、十二烷基苯磺酸和3-氨基丙基3-乙氧基硅烷为原料,通过共沉淀法合成了APTES修饰的超顺磁Fe3O4纳米颗粒,通过酰胺化法合成了叶酸偶联的超顺磁Fe3O4纳米颗粒,以X射线衍射仪、透射电镜、红外光谱仪、振动样品磁强计、动态光散射仪对合成材料进行表征,采用SRB法对叶酸偶联的超顺磁Fe3O4纳米颗粒细胞进行安全性检测,同时建立活体瘤鼠动物模型,对其在叶酸偶联的超顺磁Fe3O4纳米颗粒标记前后进行MRI成像对比检测,每个肿瘤组织块各取2套切片,分别行苏木素-伊红染色和普鲁士蓝染色,观察肿瘤组织光镜下形态及组织内含Fe情况。结果:所制备的叶酸偶联的Fe3O4纳米颗粒为立方相的Fe3O4,粒径约8 nm左右,水合直径25.7nm,呈近似球形,表面分布有羧基等功能基团,呈超顺磁特性,饱和磁化强度为51 emu/g Fe。叶酸偶联的超顺磁Fe3O4纳米颗粒对人皮肤成纤维细胞(HSF)的生长与生理盐水对照组的影响一样,无明显抑制细胞生长的表现。同时,磁共振成像和染色结果均显示肿瘤的存在。结论:叶酸偶联的超顺磁Fe3O4纳米颗粒,不仅细胞毒性小,而且因其表面的叶酸与叶酸受体之间的高强结合力。同时,它能通过这种结合作用被高效介导进入肿瘤细胞内,增强MRI成像中肿瘤组织与周围正常组织的对比度,有利于肿瘤细胞的标记、示踪和靶向检测,是一种很有应用前景的肿瘤细胞靶向检测物质。     

一株胞内合成纳米磁性颗粒菌株的筛选及鉴定

【目的】从聊城东昌湖湖水中分离纯化出一株可合成纳米磁性颗粒的菌株,将其命名为TZ-1。【方法】对该菌株进行形态学研究、分子生物学鉴定,将TZ-1菌株合成的纳米磁性颗粒进行提取纯化,并对菌体和纳米磁性颗粒进行透射电镜(transmission electron microscope,TEM)观察、扫描电镜(Scanning electron microscope,SEM)元素分析,对纳米磁性颗粒进行X射线衍射(X-ray diffraction,XRD)分析。【结果】经鉴定TZ-1属于伯克霍尔德氏菌属(Burkholderia sp.)。透射电镜下菌体为杆状,易聚集,有明显的单生鞭毛,有荚膜,在TEM下观察菌体内部有两种电子致密颗粒,较小颗粒分布在菌体细胞膜附近,近似多边形,大小约为60 nm,较大颗粒分布在菌体内部,大小约为180 nm,表面有膜包裹。扫描电镜(SEM)下细胞为杆状,大小与TEM下测量结果一致。SEM下对磁性颗粒进行元素分析,主要为Fe、P、O。根据TEM、SEM、XRD结果推测菌体可合成纳米磁性颗粒。【结论】分离纯化出的菌株TZ-1可合成纳米磁性颗粒,磁性颗粒X射线衍射结果分析知TZ-1合成的纳米磁性颗粒为单斜晶体,主要成分为Fe3(PO4)2·8H2O和Fe3O4。     

掺铁TiO2纳米颗粒与恒定磁场对HL60白血病肿瘤细胞的灭活效果

通过研究不同浓度、不同磁场作用下TiO2、掺铁TiO2纳米颗粒对HL60白血病细胞活性的影响,以及在接受光照和不接受光照条件下的细胞活性,探讨基于TiO2、掺铁TiO2纳米颗粒作为光敏剂的光动力疗法(PDT)灭活白血病肿瘤细胞的可行性.实验结果表明,纳米颗粒对细胞具有一定的抑制/毒性作用,纳米浓度越大,抑制/毒性作用越明显;磁场对细胞的毒性/抑制作用跟掺铁的浓度以及磁感应强度有关,掺铁纳米组在强磁场作用下对细胞抑制/毒性作用明显;此外,添加了纳米颗粒的PDT灭杀效率要比不添加纳米颗粒的PDT灭杀效率高.     

羟基喜树碱纳米颗粒超声反溶剂法制备工艺及表征

为提高羟基喜树碱的水溶性及其制剂在体内稳定性,运用超声反溶剂法对羟基喜树碱进行初级颗粒制备。本文根据羟基喜树碱在不同有机溶剂中的溶解度与其在去离子水中的溶解度的不同进行对比,对各项指标进行检测。筛选出制备羟基喜树碱初级颗粒的最佳条件为:HCPT-DMSO浓度为5 mg·mL-1、H2O∶DMSO=1∶1、H2O滴速为4 mL·min-1,超声时间为10 min。对羟基喜树碱初级纳米颗粒进行检测,SEM扫描结果显示其形貌规则,粒径为746 nm,与羟基喜树碱原粉颗粒相比,粒径明显减小并在其水溶液中分布更为均匀。     

纳米氧化锌对斑马鱼鳃组织的氧化损伤

正纳米颗粒是指粒径在1—100 nm,表面积较大,具有块状颗粒所没有的特有性质。由于纳米颗粒具有独特的理化性质,近年来合成和生产纳米颗粒的产量大大增加[1]。纳米氧化物颗粒在科研和工业产品的应用正在逐年增加,科学家预测依靠纳米技术创造的产品产生的价值,到2015年可能达到1万亿美元[2]。随着纳米颗粒的使用,它对人类健康和环境的风险也随之增加。因此了解纳米颗粒的不利影响,确定对生物的影响,确保纳米材料的安全使用是十分必要的[3]。     

相互作用对纳米颗粒跨生物膜输运的影响

纳米颗粒与生物膜之间的相互作用,对于纳米颗粒在细胞成像、生物传感器设计、药物输送及疾病诊断和治疗等方面的应用有着重要的影响.本文采用自洽场理论,考察了不同相互作用条件下,纳米颗粒跨膜输运过程中生物膜的形变情况,以及系统自由能的变化情况.结果表明,在纳米颗粒跨膜输运的过程中,随着纳米颗粒与生物膜之间相互作用的改变,生物膜...     

基于Fe-TiO_2和Ni-TiO_2的PDT体外灭活HL60细胞的试验研究

本文通过溶胶-凝胶法制备了Fe-TiO_2和Ni-TiO_2纳米颗粒,并研究这两种纳米颗粒体外光动力疗法(PDT)对HL60细胞的灭活效果。通过透射电镜(TEM)、能谱仪(EDS)、X射线衍射(XRD)、紫外-可见光(UVVis)吸收光谱等方法对纳米颗粒进行表征。使用CCK-8法分别测定Fe-TiO_2和Ni-TiO_2对HL60细胞的灭活效果。结果表明,不同终值浓度及掺杂量的Fe-TiO_2和Ni-TiO_2纳米颗粒对HL60细胞的暗毒性较低,但是PDT效率均显著高于未掺杂的TiO_2。在各自的最佳作用参数下,PDT灭活效率分别达到72. 5%±1. 6%和56. 4%±1. 2%。此外,还对这两种纳米颗粒灭活效果的差异进行了探讨。     

壳聚糖纳米磁性微球固定脂肪氧合酶的研究

实验采用溶胶凝胶法制备了纳米磁性Fe3O4,并用壳聚糖对颗粒2四川大学,生命科学学院,四川成都表面进行了表面修饰得到壳聚糖纳米磁性微球复合载体,再以戊二醛为交联剂将脂肪氧合酶固定在复合载体上,并测定了不同因素对游离酶和固定化酶活性的影响;实验表明,微粒在电镜观察下呈亮黑色球状,直径约为150nm,并具有良好的磁性,固定在载体上酶的含量约为7.6%,游离酶的最适温度为30℃,最适p H8.0,而固定化酶的最适温度为30℃,最适p H9.0,当H2O2浓度为12.0 g/L时,游离酶和固定化酶的活性最强;实验结果表明通过交联的方法成功将脂肪氧合酶固定在了纳米磁性四氧化三铁颗粒上,并表现出了较好的活性。     

六种藓类植物茎的比较解剖学研究

通过对6种藓类植物,即褶叶青藓(Brachythecium salebrosum(Web.et Mohr.)B.S.G.)、湿地匐灯藓(Plagiomnium acutum(Lindb.)Kop.)、侧枝匐灯藓(Plagiomnium maximoviczii(Lindb.)Kop.)、大凤尾藓(Fissidensnobilis Griff.)、大羽藓(Thuidium cymbifolium(Doz.et Molk.)B.S.G.)和大灰藓(Hypnum plumaeforme Wils.)嫩茎和老茎的石蜡切片和显微观察发现,同一藓类植株的嫩茎和老茎,茎结构稳定,不同种藓类植物茎横切面具有不同特征.植物体茎横切面形状、表层细胞的层数、细胞大小和细胞壁厚薄、皮层细胞大小和形状、中轴的有无以及比例等特征可以作为藓类植物的分科分类依据之一.     

Photoregulation of seed germination of wild-type and of an aurea-mutant of tomato

Seed germination of an aurea mutant of tomato ( Lycopersicon esculentum Mill.) is promoted by continuous irradiation with red, far-red or long-wavelength far-red (758 nm) light as well as by cyclic irradiations (5 min red or 5 min far-red/25 min darkness). Far-red light applied immediately after each red does not change the germination behaviour. Seed germination of the isogenic wild-type, cv. UC-105, is promoted by continuous and cyclic red light while it is inhibited by continuous and cyclic far-red light and by continious 758 nm irradiation. Far-red irradiation reverses almost completely the promoting effect of red light. The promoting effect (in the aurea mutant) and the inhibitory effect (in the wild-type) of continuous far-red light do not show photon fluence rate dependency above 20 nmol m⁻² s⁻¹. It is concluded that phytochrome controls tomato seed germination throgh low energy responses in both the wild type and the au mutant. The promoting effect of continuous and cyclic far-red light in the au mutant can be attributed to a greater sensitivity to P_fr.     

Cause of Senescence of Nine Sorts of Flowers

The levels of endogenous phytohormones and respiratory rate in nine sorts of flowers such as Cymbidium faberi Rolfe, Nopalxochia ackermannii Kunth and others were investigated both at full bloom and senescence and meanwhile the effect of exogenous phytohormones on prolonging the blossoms and promoting ethylene production were tested. There is a high content of endogenous ethylene in all the long-lived flowere, about 3–16 folds higer than the short-lived ones. There is a high level of ABA at full blooming flowers of short-lived flowers, in which there is no or only some cytokinins in it, but the ratio of CTK (6BA+zeatin)/ABA is smaller(l.7). The endogenous ABA reached a much higher level at senescence in all nine sorts of flowers, so it is reasonable to consider that it is ABA which plays an important role of regulation in controlling flower's senescence. There is a much higher level of GA3 and zeatin in the long-lived flowers which is not demonstrated in the shortlived ones. The respiratory rate is one of the factors controtling the longevity of flowers, but it does not play a decided role. Application of 6BA and zeatin prolongs distinctly orchid’s longevity, however exogenous IAA through the promotive action on ethylene production, evidently extends the longevity of the flowers of the Nopalxochia ackermannii Kunth.     

真菌类遗传学分析的知识结构教学

本文以认知结构理论为指导,讨论了真菌类遗传分析与高等动植物遗传分析的内在联系,认为利用这种内在联系进行教学可收到好的效果并说明了作者的具体教学过程。 Abstract:In the paper, the relationship between genetic analysis of Fungi and genetic analysis of high animal and plant was discussed.A good results were obtained when we adopted this method in the teaching.     

龙胆科药用植物化学成分的研究现状

龙胆科植物在我国的分布范围很广,且多数为药用植物,其多数种属的药用植物,至今其化学成分尚未被系统研究。综述了目前龙胆科药用植物的化学成分的研究现状及一般提取方法,对近年来发现的环烯醚萜及裂环烯醚萜类化合物进行了总结,为本科药用植物的更深入研究提供了参考。     

Interconnection of parameters of regulation system of lipid peroxidation and of morphophysiological parameters of mouse liver

A complex analysis of seasonal fluctuations of the mean group parameters of the system of regulation of lipid peroxidation has been performed in liver of Balb/c mice. Association of lipid characteristics and morphophysiological parameters is studied in the Balb/c mouse liver. An inter-connection is revealed between the liver index and the amount of lysoforms of phospholipids, the scale and character of the interconnection differing essentially depending on proportion of phos-phatidylcholine in mouse liver phospholipids.     

The effects of glutamine of the maintenance of embryogenic cultures of Cryptomeria japonica

Summary Embryogenic tissues of sugi (Cryptomeria japonica) were induced on a modified Campbell and Durzan (CD) medium containing 1 μM 2,4-dichlorophenoxyacetic acid (2,4-D) and 600 mg l⁻¹ glutamine, and subcultured in the medium of the same composition for over 1 yr. This resulted in a mixed culture of embryogenic and non-embryogenic cells. When embryogenic cells were isolated and cultured independently, their capacity to form embryogenic aggregates was lost. Thus, the non-embryogenic cells present within a mixed culture system were essential to the formation of embryogenic aggregates. When embryogenic tissues were isolated and cultured independently on a high glutamine-containing (2400 mg l⁻¹) medium, dry weights and endogenous levels of glutamine increased, and the tissue could generate a large number of embryogenic aggregates. Amino acid analysis of embryogenic and non-embryogenic cells from the maintenance culture indicated a higher level of glutamine was present in the latter. The high endogenous level of glutamine in the non-embryogenic portion of mixed cell masses may be the supplier of glutamine for maintaining the embryogenic property of the tissues.     

Specificity of action of piperidylcholine derivatives as substrates of cholinesterases of various origin

The review deals with study of enzymologic properties of a novel highly specific acetylcholinesterase substrate, N-(β-acetoxyethyl) piperidinium iodomethylate (“piperidylcholine”), and its 30 derivatives that were tested as effectors of cholinesterases of mammals and various species of Pacific squids. It was proven for the first time that responsible for specificity of action was structure of cyclic ammonium grouping of the alcohol part of molecule of the ester substrate. Analysis of specificity is performed based on enzymatic hydrolysis parameters—activity of catalytic center of cholinesterases and bimolecular constant of the reaction rate that are determined at optimal and low substrate concentrations. Among the specially synthesized group of thioester compounds there is revealed one more highly specific acetylcholinesterase substrate—N-(β-acetoxyethyl) piperidinium.