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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
211

Kultury léčivých rostlin in vitro - XII. / In vitro cultures of medicinal plants - XII.

Janoutová, Martina January 2012 (has links)
Martina Janoutová In vitro cultures of medicinal plants - XII. Abstract The effect of ultrasound (US) as abiotic elicitor on the flavonolignans production in Silybum marianum L suspension culture was investigated. The culture was cultivated in Murashige and Skoog nutritive medium with ( - NAO) (g/l) as growth regulator at 25o C and luminous period 16 h of light and 8 h of darkness. The elicitor - ultrasound by frequency 35kHz and intensity 0,1Wcm-3 for a period 1, 2, 3, 4 and 5 min has been used. The samples were taken in 0, 6, 12, 24, 48, 72 and 168 h after US exposition. The control samples were taken in 0 and 48 h. The quantity of flavonolignans was determined by High performance liquid chromatography (HPLC). The highest increase of taxifolin content was apparent after 5 min of US elicitation and 48 h sampling (0,04%) - 400%, other increase was apparent after 5 min of elicitation and 72 h sampling. The higher content of silychristin was found after 1 min of US elicitation and 72 h sampling, the same level was observed after 2 min of elicitation and 24 h sampling. The higher level of silydianin was detected after 2 min of US elicitation and 6 h sampling and the silybin B after 2 min of elicitation and 12 h sampling after exposition. Taxifolin and flavonolignans release to the nutrient medium was...
212

Kultury léčivých rostlin in vitro - XIII. / In vitro cultures of medicinal plants - XIII.

Kubeš, Jan January 2012 (has links)
Jan Kubeš Genista tinctoria in vitro - abiotická elicitace Cultures of medicinal plants in vitro - XIII. The plants cultures in vitro contain lesser amounts of secondary metabolites in compare with intact plants. The elicitors can affect these metabolites production. The effect of electric current (50mA) of different voltage (5, 7, 8, 10, 15, 20 and 24 V) and different time exposition (10, 30, and 60 minutes) on content of isoflavones was studied on (Genista tinctoria) suspension culture. The highest concentration of genistin (0.17 %) was measured in suspension culture after 30 min of elicitation by 10 V after 6 hours of cultivation. The highest concentration of daidzein (0.35 %) was found in suspension culture after 60 min of elicitation by 5 V after 24 hours of cultivation. The highest concentration of genistin (1.6 mg/100ml) was measured in medium after 30 min of elicitation by 5 V after 24 hours of cultivation. The highest concentration of daidzein (1.77 mg/100ml) was found in medium after 10 min of elicitation by 24 V after 6 hours of cultivation.
213

Caractérisation et toxicité de nanoparticules manufacturées de fer chez Physcomitrella patens (Hedw. Bruch & Schimp.) et sur cellules épithéliales bronchiques humaines (HBEC) : vers une utilisation en biosurveillance d’aérocontaminants nanoparticulaires / Characterization and toxicity of engineered iron nanoparticles on Physcomitrella patens (Hedw. Bruch & Schimp.) and human bronchial epithelial cells (HBEC) : towards use in biomonitoring of airborne nanoparticles contaminants

Canivet, Ludivine 13 December 2013 (has links)
De nombreux sites industriels émettent, non-intentionnellement, depuis des années des particules ultra-fines dans l’air. De nombreuses questions se posent sur leurs effets sur les écosystèmes et la santé humaine. Dans ce contexte, nous avons axé nos recherches autour de nanoparticules de fer manufacturées (Fe-NP), représentatives de celles que l’on retrouve dans les fumées des industries métallurgiques dunkerquoises et nous avons mené en parallèle des études d’écotoxicité et de toxicité. L’objectif principal de ces recherches était d’étudier l’impact de Fe-NP manufacturées exposées par voie aérienne sur deux modèles biologiques : Physcomitrella patens (Hedw.) Bruch & Schimp. et des cultures primaires de cellules épithéliales bronchiques humaines (HBEC). Pour répondre à ces objectifs, nous avons dû passer par l’étape indispensable qu’est la caractérisation fine de notre modèle de NP. En effet, la caractérisation physico-chimique doit être la plus complète possible (8 paramètres) de façon à déterminer, au préalable, leurs propriétés de surface. Puis, nous avons vérifié leur pénétration au sein de nos modèles biologiques. Puis, des biomarqueurs liés au stress oxydant ont été dosés chez la bryophyte, exposée à des concentrations faibles en Fe-NP. Premièrement, aucune perte de vitalité chez notre plante n’a pu être observée au cours du temps aux doses testées. Nos études n’ont pas permis de mettre en évidence une augmentation significative des espèces réactives de l’oxygène et du malondialdéhyde ; ainsi qu’une modulation significative du ratio GSSG/GSH, même si un phénomène de « sur-compensation » peut être évoqué sur le long terme, conduisant à la production de GSH au sein de notre plante témoignant d’une adaptation de la plante au stress. Enfin une analyse toxicogénomique a montré des modulations de l’expression (non significatives) de tous les isoformes des gènes d’intérêt étudiés aux doses testées. Dans le cadre d’études de toxicité, nous avons caractérisé notre modèle cellulaire par coloration immunocytologique. Puis, un test de viabilité nous a permis de choisir notre dose d’exposition : 2 μg.cm-2. Les travaux sur le stress oxydant et la modulation de l’expression génique ont été réalisés sur des cultures de cellules issues de trois patients différents pour prendre en compte la variabilité interindividuelle. Contrairement à certaines publications, nous n’avons pas montré une augmentation dose-dépendante des ROS. Puis, notre étude pangénomique, nous a permis de sélectionner 10 gènes d’intérêt dont l’étude approfondie a mis en évidence des effets précoces (dès 6 h d’exposition) sur des gènes impliquées dans des phénomènes inflammatoires. Néanmoins, les Fe-NP n'ont pas causé d’augmentation significative du MDA et du ratio GSSG/GSH après plusieurs jours d'exposition. Suite à ces résultats, il est maintenant envisageable de mener des recherches sur les impacts des nanoparticules d’origine environnementale à l’aide de nos deux modèles biologiques et d’améliorer les connaissances concernant leur danger potentiel pour l’environnement et la santé humaine. / Many industries emit, unintentionally, ultra-fine particles in the air, for many years. Many questions arise about their effects on ecosystems and human health. In this context, we focused our research on the iron-engineered nanoparticles (Fe-NP), representative of industrial smoke emitted by metallurgical industries and we conducted, in parallel, toxicity and ecotoxicity studies. The main objective of this work was to study the impact of Fe-NP exposed by air in two biological models: Physcomitrella patens (Hedw.) Bruch & Schimp. and primary cultures of human bronchial epithelial cells (HBEC). To meet these objectives, we had to characterize our NP model. Indeed, the physic-chemical characterization must be as complete as possible (8 parameters) to determine, firstly, their surface properties. Then, we checked their penetration within our biological models. And, oxidative stress biomarkers were measured in the bryophyte, exposed to low concentrations of Fe-NP. Firstly, any loss of vitality could be observed over time at the doses tested. Our studies have failed to demonstrate a significant increase of reactive oxygen species and malondialdehyde, and a significant modulation of the ratio GSSG/GSH, although the phenomenon of "over-compensation" can be discussed, over the long term, leading to the production of GSH in our plant showing a plant adaptation to stress. Finally a toxicogenomic analysis showed modulation of expression (not significant) of all isoforms of the genes of interest studied at the doses tested. For toxicity studies, we characterized our cellular model by immunocytological staining. Then, a viability test allowed us to choose the exposure dose: 2 μg.cm-2. The research on oxidative stress and the modulation of gene expression were performed on cells derived from three different patients to take into account individual variability. Unlike some publications, we did not show a dose-dependent increase of ROS. Then, the pangenomic study has allowed us to select 10 genes. A detailed study of this genes showed early effects (from 6 h of exposure) in genes involved in inflammation. However, Fe-NP did not cause any significant increase of MDA and GSSG/GSH ratio after several days of exposure. Following these results, it is now possible to conduct research on the impacts of ultra-fine particles using our two biological models and improve knowledge about their potential danger on the environment and human health.
214

Division parameters of aspartate-grown Escherichia coli 15T- following nutritional shift-up

Sloan, Janice Butin January 2011 (has links)
Digitized by Kansas Correctional Industries
215

Development of the double-tube system for the cultivation of anaerobic bacteria from foods

Anderson, Kevin Lee January 2011 (has links)
Typescript (photocopy). / Digitized by Kansas Correctional Industries
216

Attempts at axenic cultivation of Histomonas meleagridis

Hirsch, Diane S. January 2011 (has links)
Digitized by Kansas Correctional Industries
217

Alkaloid Production by Hairy Root Cultures

Zhao, Bo 01 May 2014 (has links)
In the present research, nicotine alkaloid production by Nicotiana tabacum (tobacco) hairy roots and tropane alkaloid production by Hyoscyamus niger hairy roots were investigated. The first objective of this research was to improve the oxygen mass transfer in hairy root cultures with microbubbles. Oxygen was shown as a critical nutrient for the growth of tobacco and H. niger hairy roots. In a 1-liter fermentor, microbubble dispersion improved the oxygen mass transfer, tobacco hairy root growth, and nicotine production in the medium. In a novel ground-joint column bioreactor, microbubbles enhanced the oxygen mass transfer and the growth of H. niger hairy roots. The second objective of this research was to enhance the release of alkaloids from the hairy roots into the culture medium. In a l-liter fermentor, nicotine concentration in medium was improved by adjusting the medium pH to 6. Unlike the nicotine alkaloid, hyoscyamine concentration in medium was not detectable at medium pH 6, whereas hyoscyamine in medium increased to 42 mg l-1 at medium pH 3. Similar to the hyoscyamine, scopolamine in medium increased from 0.1 to 11 mg l-1 when the medium pH was adjusted from 6 to 3. The release of alkaloids into culture medium provides opportunities to isolate a high-value alkaloid directly from the culture fluid, and reduces the cost of product recovery.
218

Aspects of the production of viscous capsular material by the yoghurt starter, Streptococcus thermophilus

Taylor, Darren P, mikewood@deakin.edu.au January 1996 (has links)
The technology of modern fermented milk production is not complicated and relies largely on the characteristics of the microorganisms used in its manufacture. Biochemical substances excreted by the starter cultures contribute to the chemical, physical and organoleptic properties of cultured milks. Chemical and organoleptic properties of yoghurt starter cultures have been widely studied over several decades. Conversely the biosynthetic processes and genetic control of the production of viscous extracellular material (slime) by selected thermophillic streptococci is still insufficiently understood. This study attempted to elucidate physiological aspects and the genetic control of slime production. An attempt to chemically induce ropiness was also preformed. Twenty strains of Gram positive, thermo-tolerant, milk dotting, catalase negative cocci were collected from a variety of sources. All strains were identified as Streptococcus thermophilus. Four of the isolates were identified as capable of producing an extracellular, ‘ropy’ capsular material. A negative staining method for highlighting capsular material under light microscopy was described. Ropy isolates displayed thick capsular zones of between 6-8 μm. The isolates graded as non-ropy produced only small capsular zones (less than 2 μm); two variants displayed no capsular material. Instability of the ropy phenotype during subculture and prolonged storage was described for all four ropy isolates at varied temperatures. Instability during transfer was reported as moderate with a loss of no more than 45% of ropy colonies after 15 subcultures at 48°C A significant increase in instability, during transfer, associated with an increase in incubation temperature (37-48°C) was also reported. Prolonged storage of ropy variants over ten days resulted in a drop in the number of ropy colonies. The loss was minimal when cultures were stored at 8°C, but excessive (approaching 100%) at 37°C This suggested the presence of capsular degradative substances. Analysis of the plasmid profiles of 20 strains identified only two strains harboured plasmid DNA. All plasmids were small, less than 23kilobases, and each strain possessed a single plasmid species. Only one ropy strain contained plasmid DNA that was shown, with the aid of curing experiments, not to be linked to production of the ropy phenotype. The amino acid analogue p-fluoro-DL-phenylalanine was unsuccessful in generating ropy colonies from non-ropy variants of Streptococcus thermophilus at low concentrations. Some technological considerations for the use of ropy variants of Streptococcus thermophilus in yoghurt starter cultures were made.
219

Coming through

Drew, Raymond, n/a January 1996 (has links)
Coming Through, a novel based on factual events, explores elements of the alternative sub-culture in Australia in the period between 1959 and 1980. Dual protagonists, Anna Martin and Jack Rose, personify aspects of the movement that would later be known as 'psychedelic romanticism.' The narrative follows Jack Rose's disenchantment with the prevailing social system and his efforts to achieve personal integration and his conflict with societal pressures to conform. Likewise, in a parallel narrative, it describes the events that surround Anna Martin's early institutionalisation and her attempt to achieve personal authenticity. When the protagonists finally encounter one another they find that a common and binding philosophy has drawn them together. The thesis looks at the prevailing social notions of'normality' at the time and the problems associated with alienation and the struggle to found alternative life styles in a society they deem to be repressive.
220

Relationships and identities as 'storied orders' : a study in three generations of Greek-Australian women

Petraki, E. Unknown Date (has links)
No description available.

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