恒定磁场对大肠杆菌生长繁殖影响

目的:研究恒定磁场在静态处理和动态处理两种处理方式下对大肠杆菌生长繁殖的影响.方法:将处于对数生长期的大肠杆菌茵液置于磁场中(静态处理)或使菌液循环流动并通过磁场(动态处理),用平板法测定不同时刻菌液的活菌数,记录下菌落形成单位(CFU)的数目,并与相应时申刻对照样(无磁处理)的CFU作对比.结果:两种处理方式下,菌液的相对CFU的数目都有下降.且动态处理的下降幅度大于静态处理.结论:恒定磁场在两种处理方式下都对大肠杆菌起到明显的杀死或抑制作用.文章的讨论部分总结了产生这种作用的可能机理.     

动态磁场下微生物的生物学效应研究

磁场是一种普遍存在的环境因子,但其对微生物的影响尚不清楚.使用超导磁体产生的静态磁场,配以自制实验装置对所选菌株(枯草芽胞杆菌和鼠伤寒沙门氏菌)进行动态磁场处理,比较处理组与地磁场对照组之间包括生长曲线、酶活力等在内的各项生理生化指标,研究动态磁场对微生物的影响.研究发现,动态磁场下两株细菌的生长过程均受到影响.处理组枯草芽胞杆菌对数期提前,衰亡期菌体死亡速率受抑制,碱性蛋白酶活力增加,中性蛋白酶活力降低,而蛋白酶表达量无差异;鼠伤寒沙门氏菌动态磁场处理组对数期推迟,衰亡期菌体死亡亦受到抑制,细菌粘附实验与侵袭力实验表明,细菌毒力相对增强.以上结果表明,动态磁场可对微生物产生影响.并随着微生物种类的不同而异.     

磁场处理中草药穿心莲药液对小白鼠肠推进运动的影响

本文探讨了磁场处理中草药穿心莲药液对小白鼠肠推进运动的影响。结果表明:经0.1T和0.25T磁场处理中草药穿心莲药液与未经磁场处理的穿心莲药液相比较,具有显著促进小鼠小肠的炭末推进率。     

磁场对某些农作物生长影响的实验研究

用磁场处理种子和磁处理水浸种的方法,对小麦、玉米、大豆、黄瓜、茄子、辣椒、葱和芸豆等进行了实验研究。结果表明,效果是明显的。     

磁场处理山豆根药液对小白鼠肠推进运动的影响

用经0.1T和0.25T磁场处理山豆根药液灌小白鼠胃,分别测定它们对小白鼠肠推进运动的影响。实验结果显示:0.25T磁场处理山豆根药液对小白鼠肠推进活动有明显促进作用,而0.1T磁场处理山豆根药液对小白鼠肠推进活动不明显,实验表明达到一定强度磁场才影响山豆根药液的药效。     

微生物磁学研究现状述评

近年来,有关微生物磁学特性的研究成为一个热点,主要集中在磁场作用下微生物的生物活性和致基因突变性的研究,利用脉冲电磁场灭菌和趋磁性细菌在工业、医学等方面的应用,以及磁场在农业上提高微生物增肥效果和矿冶上细菌的浸矿效果。     

磁场处理中草药穿心莲药液对小白鼠肠推进运动的影响

本探讨了磁场处理中草药穿-心莲药液对小白鼠肠推进运动的影响。结果表明：经0.1T和0.25T磁场处理中草药穿-心莲药液与未经磁场处理的穿心莲药液相比较。具有显促进小鼠小肠的炭末推进率。     

细菌生物膜研究技术

细菌生物膜是细菌生长过程中为适应生存环境而在固体表面上生长的一种与游走态细胞相对应的存在形式。只要条件允许,绝大多数细菌都可以形成生物膜。一旦形成了生物膜细菌就具有极强的耐药性,在医疗、食品、工业、军事等诸多领域给人类社会带来了严重的危害,造成巨大的经济损失。因此,细菌生物膜已成为全球关注的重大难题,也是目前科学界研究的前沿和热点。本文结合细菌生物膜研究技术的最新进展,重点介绍了几种常用生物膜发生装置及检测量化技术,并对其原理及优缺点进行了讨论。     

磁场处理山豆根药液对小白鼠肠推进运动的影响

用经0.1T和0.25T磁场处理山豆根药液灌小白鼠胃,分别测定它们对小白鼠肠推进运动的影响,实验结果显示：0.25T磁场处理山豆根药液对小白鼠肠推进活动有明显促进作用,而0.1T磁场处理山豆根药液对小白鼠肠推进活动不明显,实验表明达到一定强度磁场才影响山豆根药液的药效。     

磁场对羊草过氧化物酶的激活效应及同工酶分析

利用外磁场处理羊草种子,并将羊草进行盐（ＮａＣｌ）碱（Ｎａ２ＣＯ３）混合胁迫处理,结果表明,磁场处理不仅促进了羊草的生长,而且提高了羊草的抗盐碱性。磁场使羊草过氧化物酶（ＰＯＤ）活性提高,并且诱发了一条新的同工酶带。根据羊草的长势及ＰＯＤ活性分析,确定羊草最佳的磁处理参数是３００ｍＴ处理,其次是２００ｍＴ。     

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.     

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.     

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.     

Physiological characteristics of various species of strains of carboxydobacteria

Seven strains of aerobic carbon monoxide-oxidizing bacteria (carboxydebacteria) when growing on CO as sole source of carbon and energy had doubling times which ranged from 12–42 h. The activity profiles obtained after discontinuous sucrose density gradient centrifugation indicated that the CO-oxidizing enzymes are soluble and the hydrogenases are membrane-bound in all strains examined. The CO-oxidizing enzymes of Pseudomonas carboxydohydrogena, Pseudomonas carboxydoflava, Comamonas compransoris, and the so far unidentified strains OM2, OM3, and OM4 had a molecular weight of 230,000; that of Achromobacter carboxydus amounted to 170,000. The molecular weights of the CO-oxidizing and H₂-oxidizing enzymes turned out to be identical. The cell sonicates were shown to catalyze the oxidation of both CO and H₂ with methylene blue, thionine, phenazine methosulfate, toluylene blue, dichlorophenolindophenol, cytochrome c or ferricyanide as electron acceptors. Methyl viologen, benzyl viologen, FAD⁺, FMN⁺, and NAD(P)⁺ were not reduced. The spectrum of electron acceptors was identical for all strains tested. Neither free formate, hydrogen nor oxygen gas were involved in the CO-oxidation reaction. Methylene blue was reduced by CO at a 1:1 molar ratio. The results indicate that CO-oxidation by carboxydobacteria is catalyzed by identical or similar enzymes and that the reaction obeys the equation CO+H₂OCO₂+2H⁺+2e^- as previously shown for Pseudomonas carboxydovorans.Dedicated to Otto Kandler remembering almost three decades of enjoyable cooperation     

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.