首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 109 毫秒
1.
本文从培养基组成、通气量、培养温度及培养时间四个方面研究并提出了L-丙氨酸生产菌种PseudomonasIAM1152-A的最佳培养条件。  相似文献   

2.
本课题观察了低氧及血管紧张素Ⅱ(angiotensinⅡ,AngⅡ)对分离培养家兔肺内小动脉平滑肌细胞(PASM-Cs)膜Ca2+-ATPase活力的影响,同时用钙通道阻断剂维拉帕米(verapamil,VP)进行干预,进一步了解细胞内钙与Ca2+-ATPase活力的关系。结果表明:PASMCs膜Ca2+-ATPase活力对低氧具有短暂的耐受性,随低氧时间延长,Ca2+-ATPase活力呈时间依赖性抑制;低氧、ANGⅡ均能抑制Ca2+-ATPase活力(P<0.01)低氧+AⅡ对Ca2+-ATPase活力的抑制具叠加效应(P<0.05);VP可逆转低氧、AngⅡ、低氧+AngⅡ对Ca2+-ATPase活力的抑制(P<0.01)。结果提示:低氧,ANGⅡ可通过抑制肺血管平滑肌细胞膜Ca2+-ATPase活力而可能削弱肺血管平滑肌舒张功能也可能是低氧性肺动脉高压(HPH)形成的原因之一。  相似文献   

3.
马振国  董金泉 《菌物系统》2000,19(3):360-365
芸薹链格孢(Alternaria brassicae)在PD液体培养其中黑暗培养20d,过滤获得培养滤液,经乙酸乙酯萃取,45℃减压浓缩得AB-粗毒素。AB-粗毒素经HPLC分析,在λ=nm波长下具有Ⅰ、Ⅱ、Ⅲ和Ⅳ4个明显的吸收峰。组分Ⅲ的红外吸收光谱、FAB/MASS和^1H-NMR与已报道的腐败菌素B基本一致,由此确定组分Ⅲ为腐败菌素B。试验发现,芸薹链格孢的培养滤液,AB-粗毒素和毒素组分Ⅲ  相似文献   

4.
γGABA对大离体培养颗粒细胞生成雌二醇的影响及作用机制   总被引:1,自引:0,他引:1  
目的和方法:实验采用离体培养大颗粒细胞的方法,观察儿源性γ-GABA对其雌二醇生成影响。为进一步探讨其作用机制,还观察在γ-GABA受体激动剂蝇覃醇、蛋白质合成抑制剂放线菌酮、腺苷酸环化酶激动剂forskolin作用下,γ-GABA对颗粒细胞生成雌二醇的影响。结果:γ-GABA抑制大鼠颗粒细胞的雌二醇生成,蝇覃醇有同样γ-GABA减少forskolin作用下的大鼠颗粒细胞的雌二醇生成。结论:γ-G  相似文献   

5.
Liu D  Lu JS  Yin XL 《生理学报》2000,52(6):483-486
观察pp60c-src在血管紧张素Ⅱ(AngⅡ)诱导血管平滑肌细胞(VSMCs)内丝裂原活化蛋白激酶(MAPK)激活中的作用,以了解AngⅡ促VSMCs增殖的信号转导过程。将合成的反义c-src寡脱氧核苷酸(oligodeoxynucle-otides,ODNs)以脂质体包裹转染培养的大鼠VSMCs,用Western印迹测得细胞裂解液中pp60c-src含量明显下降,免疫沉淀方法测得pp60c-s  相似文献   

6.
本文报导国人睾丸、附睾和输精管的NSE,AChE,ChE,ALP,ACP,5'-Nase,G-6-Pase,β-GA,β-GR,AP-M,ATPase和TPPase水解酶的组织化学活性、结果显示:睾丸曲细精管的ALP,5'-Nase和ATPase;睾丸间质细胞的NSE,ALP,ATPase和ACP;睾丸间质中的NSE,ALP和AT-Pasc;睾丸输出小管和附睾管上皮的NSE,ALP,ACP,5’-Nase,β-GA,β-GR,ATPase和Tppase;附睾头部间质中的NSE,AChE,ALP,和ATPase;输精管上皮细胞的ATPase的酶活性均呈强阳性或极强阳性。说明人类睾丸、附睾和输精管含有丰富的水解酶,尤其是附睾头部的输出小管、附睾管和头质均含有种类多活性高的水解酶,在精子的功能成熟上起了重要的作用,提示其可能作为生育与不育诊治中的重要指标。  相似文献   

7.
过去所得的实验表明,植物中ATPase活性变化与耐冷性有关。春小麦和番茄对低温是非常敏感的,当将这两种植物的幼苗在低温下培养时,质膜ATPase活性下降甚至消失。相反,在冬小麦中,当幼苗在低温下处理时,质膜ATPase活性增加.为了研究ATPase同工酶变化与植物耐冷性之间的关系,以小麦等四种植物为材料,在0-1℃低温下处理2天、2周和4周,然后检测幼苗根系内的ATPase同工酶,结果发现,在0-1℃培养时,幼苗根系内ATPase同工酶谱带减少,ATPase同工酶谱带变化与植物幼苗耐冷性呈一定相关性。ATPase同工酶谱带变化可能是受冷害所致。  相似文献   

8.
抗真菌蛋白Rs—AFPs基因在大肠杆菌中的表达   总被引:3,自引:0,他引:3  
将抗真菌蛋白Rs-AFP1和Rs-AFP2全长cDNA插入表达质粒pET-22b/NcoI+SacI位点,构建成融合蛋白表达载体pRAF1和pRAF2.将不含信号肽编码序列的Rs-AFP1和Rs-AFP2cDNA分别插入pET-22b/Ncol+Sacl和pET-22b/Ndel+SacI位点,构建成不含信号肽序列的融合蛋白表达载体pRAF3、pRAF4和非融合蛋白表达载体pRAF5和pRAF6.将构建的上述各种表达载体转化E.coliBL21,挑菌落培养,IPTG诱导,使Rs-AFPs基因得到表达,并用体外抑菌试验检测表达产物的活性,结果表明,各种表达载体的表达产物均具有不同程度的抑菌活性,其中,pRAF3和pRAF4表达产物的抑菌活性较明显.  相似文献   

9.
本工作采用分离培养家兔肺内小动脉平滑肌细胞(PASMCs),观察了外源性血小板活化因子(plateletactivatingfactor,PAF)、BN52021(PAF受体拮抗剂)、吲哚美辛、维拉帕米对PASMCs产生血栓素A_2(TxA_2)、前列环素(PGI_2)及对细胞膜Ca~(2+)-ATPase活力的影响。结果表明:(1)基础状态下PASMCs存在花生四烯酸(AA)代谢。(2)外源性PAF通过受体后途径激活环加氧酶促进AA代谢致TXA_2及PGI-2增加,TXA_2/PGI_2比值无明显变化。(3)外源性PAF能直接抑制Ca~(2+)-ATPase活力。(4)维拉帕米可逆转PAF抑制PASMCs膜Ca~(2+)-ATPase活力的效应。  相似文献   

10.
聚羟基烷酸(PHAs)是微生物细胞在其营养不平衡的生长条件下积累的一类胞内聚酯。由于PHAs具有生物可降解性和生物可相容性,因而被认为是替代化学合成塑料最具潜力的多聚体,已受到广泛的重视。目前PHAs中研究和应用的最多的是聚β-羟基丁酸(PHB)和3-羟基丁酸与3-羟基戊酸的共聚物P(HB-co-HV)。流加发酵技术是提高聚合物生产速率和改进其质量的关键,具体表现在采用Pseudomonassp.k和Alcaligeneseutrophus,在适宜的流加培养条件下,可达到聚合物在细胞内的最大积累、控制共聚物适宜的聚合分率和得到平均分子量大且分布范围窄的产物。因此针对于某种特定的微生物,研究得到生物可降解多聚体的一套最佳流加培养策略至关重要。  相似文献   

11.
12.
The simple-septate basidiomycetes: a synopsis   总被引:1,自引:1,他引:0  
The simple-septate basidiomycetes comprise more than 8,000 species that show a high morphological and ecological heterogeneity. To gain insight in the phylogenetic relationships within this group, we compared several ultrastructural features such as septal pore apparatus, form, and behavior of the spindle pole bodies, types of host–parasite interaction, presence or absence of colacosomes, symplechosomes, atractosomes, and cystosomes as well as nuclear rDNA sequences coding for small- and large-subunit rRNA. Based on our integrated analysis, we propose a new classification system for the simple-septate basidiomycetes with the subphylum Pucciniomycotina and the classes Agaricostilbomycetes, Atractiellomycetes, Classiculomycetes, Cryptomycocolacomycetes, Cystobasidiomycetes, Microbotryomycetes, Mixiomycetes, and Pucciniomycetes. We also propose the pucciniomycotinous taxa Cystobasidiales, Erythrobasidiales, Helicobasidiales, Mixiales, Naohideales, Pachnocybales, Spiculogloeales, and Kondoaceae and the new subphyla Agaricomycotina (equivalent to the current Hymenomycetes) and Ustilaginomycotina (equivalent to the current Ustilaginomycetes).  相似文献   

13.
A review of the literature on unusual metals as carcinogens was carried out. The metals covered are some of the rare earths, copper, silver, gold, mercury, germanium, tin, antimony, lead, platinum, palladium, aluminum, titanium, niobium, manganese, scandium, yttrium, indium, rhodium, and gallium.  相似文献   

14.
At one spectrum extreme, Astrobiology conjectures that for exoplanets with Goldilocks conditions, terrestrial-like life is inevitable. Moreover, it is envisaged that via panspermia, terrestrial-like life and its precursors are transferred among galaxies, stars, and within solar systems via transiting comets, asteroids, and planetoids. In addition, expelled stars, which have solar systems, it is inferred, transfer life as well. However, at the other extreme, we propose a paradigm shift that on some planets, subject to non- Goldilocks conditions, metal machine life could arise, ab initio, and evolve viruses, intelligence, and civilizations, conjointly. Accordingly, intelligent mechanized civilizations could readily and efficiently commence space exploration. Furthermore, as a counter paradigm shift, such civilizations could experiment and produce non-metallic life, based on carbon and other non-metal elements, under suitable conditions, related to Goldilocks life. Even a single example of validated interstellar or intergalactic communication received on the Earth would support the existence of life elsewhere. However, the communication platform should not be restricted to electromagnetic radiation. Other platforms should be included as well - one such example, which would require sophisticated technology, is neutrino communication. This is the case for any advanced civilization, be it metal-machine based, biological-based, and carbon-based. In sum, civilizations based on machine life, would be highly productive due to the longevity and hardiness of machine life. However, significant caveats are raised in this brief report, because possibly dissimilar psychologies and intelligence may lead to conflicts between metal machine life and biological life, inter-paradigm conflict.  相似文献   

15.
The phylogeny of groups within Gobioidei is examined with molecular sequence data. Gobioidei is a speciose, morphologically diverse group of teleost fishes, most of which are small, benthic, and marine. Efforts to hypothesize relationships among the gobioid groups have been hampered by the prevalence of reductive evolution among goby species; such reduction can make identification of informative morphological characters particularly difficult. Gobies have been variously grouped into two to nine families, several with included subfamilies, but most existing taxonomies are not phylogenetic and few cladistic hypotheses of relationships among goby groups have been advanced. In this study, representatives of eight of the nine gobioid familes (Eleotridae, Odontobutidae, Xenisthmidae, Gobiidae, Kraemeriidae, Schindleriidae, Microdesmidae, and Ptereleotridae), selected to sample broadly from the range of goby diversity, were examined. Complete sequence from the mitochondrial ND1, ND2, and COI genes (3573 bp) was used in a cladistic parsimony analysis to hypothesize relationships among the gobioid groups. A single most parsimonious topology was obtained, with decay indices indicating strong support for most nodes. Major phylogenetic conclusions include that Xenisthmidae is part of Eleotridae, and Eleotridae is paraphyletic with respect to a clade composed of Gobiidae, Microdesmidae, Ptereleotridae, Kraemeriidae, and Schindleriidae. Within this five-family clade, two clades are recovered. One includes Gobionellinae, which is paraphyletic with respect to Kraemeriidae, Sicydiinae, Oxudercinae, and Amblyopinae. The other contains Gobiinae, also paraphyletic, and including Microdesmidae, Ptereleotridae, and Schindleriidae. Previous morphological evidence for goby groupings is discussed; the phylogenetic hypothesis indicates that the morphological reduction observed in many goby species has been derived several times independently.  相似文献   

16.
1. Acetylcholine receptors were initially defined as nicotinic or muscarinic, based on selective activation by two natural products, nicotine and muscarine. Several further nicotinic agonists have been discovered from natural sources, including cytisine, anatoxin, ferruginine, anabaseine, epibatidine, and epiquinamide. These have provided lead structures for the design of a wide range of synthetic agents.2. Natural sources have also provided competitive nicotinic antagonists, such as the Erythrina alkaloids, the tubocurarines, and methyllycaconitine. Noncompetitive antagonists, such as the histrionicotoxins, various izidines, decahydroquinolines, spiropyrrolizidine oximes, pseudophrynamines, ibogaine, strychnine, cocaine, and sparteine have come from natural sources. Finally, galanthamine, codeine, and ivermectin represent positive modulators of nicotinic function, derived from natural sources.3. Clearly, research on acetylcholine receptors and functions has been dependent on key natural products and the synthetic agents that they inspired.  相似文献   

17.
The phylogenetic relationships of the caryophyllidia-bearing dorids are studied, based on the examination of the type species of all the genera previously described. The phylogenetic hypothesis supports that the caryophyllidia-bearing dorids are a monophyletic group and the sister group of the clade formed by Astemnotus Ehrenberg, 1831 and Halgerda Bergh, 1880. Several genera previously considered as valid or regarded as uncertain are here synonymized: Peronodoris Bergh, 1904, Trippa Bergh, 1877, Phlegmodoris Bergh, 1878, Petelodoris Bergh, 1881, Kentrodoris Bergh, 1876, Audura Bergh, 1878, Centrodoris P. Fischer, 1883, Anisodoris Bergh, 1898, Awuka Er. Marcus, 1955, Rhabdochiia P. Fischer, 1883, Boreodoris Odhner, 1939, Dictyodoris Bergh, 1880, Gravieria Vayssiere, 1912, Aporodoris Ihering, 1886. The following genera are regarded as valid: Astemnotus, Atagema J.E. Gray, 1850, Jorunna Bergh, 1876, Platydoris Bergh, 1877, Diaulula Bergh, 1878, Rostanga Bergh, 1879, Halgerda Bergh, 1880, Baptodoris Bergh, 1884, Gargamella Bergh, 1894, Alloiodoris Bergh, 1904, Sclerodoris Eliot, 1904, Taringa Er. Marcus, 1955, Thorybopus Bouchet, 1977. The new genus Nophodoris is described based on two new species from New Caledonia deep waters. Two additional new species from New Caledonia belonging to the genera Atagema and Gargamella are also described. Nomenclatural and taxonomic problems are discussed, and several type species, neotypes and lectotypes are selected.  相似文献   

18.
This study describes a method for predicting and classifying oxygen-binding pro- teins. Firstly, support vector machine (SVM) modules were developed using amino acid composition and dipeptide composition for predicting oxygen-binding pro- teins, and achieved maximum accuracy of 85.5% and 87.8%, respectively. Sec- ondly, an SVM module was developed based on amino acid composition, classify- ing the predicted oxygen-binding proteins into six classes with accuracy of 95.8%, 97.5%, 97.5%, 96.9%, 99.4%, and 96.0% for erythrocruorin, hemerythrin, hemo- cyanin, hemoglobin, leghemoglobin, and myoglobin proteins, respectively. Finally, an SVM module was developed using dipeptide composition for classifying the oxygen-binding proteins, and achieved maximum accuracy of 96.1%, 98.7%, 98.7%, 85.6%, 99.6%, and 93.3% for the above six classes, respectively. All modules were trained and tested by five-fold cross validation. Based on the above approach, a web server Oxypred was developed for predicting and classifying oxygen-binding proteins(available from http://www.imtech.res.in/raghava/oxypred/).  相似文献   

19.
Foliar nutrient levels of broad-leaved tropical trees: A tabular review   总被引:1,自引:0,他引:1  
Foliar nutrient levels (N, P, S, K, Ca, Mg, Al, Fe, Mn, Zn, Cu, Mo, B), of about 40 tropical and subtropical broad-leaved trees, are listed and classified as deficient, low, intermediate, high, and toxic in each case according to the interpretation and evaluation of the reviewed author(s).  相似文献   

20.
Summary Concentration of N, P, K, Ca, Mg and S in summer groundnut crop was higher than in kharif while Zn, Fe, Mn and Cu contents were higher in summer crop. Kernel's N, P and Zn; Leaflet's Ca and Mn; Stem's K and Fe; Root's S and Cu and Petiole's Mg contents were highest. Shell's N, P, K, Mg, S, Zn and Cu; Kernel's Ca, Fe and Mn contents were the least. N, P, K, S, Zn and Cu concentrations decreased linearly as the crop grew. Ca, Mg, Fe and Mn concentrations did not display any distinct pattern. Ca concentration was positively correlated with pod yield in both the seasons.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号