Tesi sul tema "Stems. leaves"
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Nellvecia, Madike Lerato. "Cytotoxic and genotoxic studies of crude extracts from the leaves, stems and roots of Tulbaghia Violacea". Thesis, Vaal University of Technology, 2017. http://hdl.handle.net/10352/364.
Tulbaghia violacea Harv. (wild garlic) has been used in traditional medicine in Southern Africa for the treatment of various ailments. Despite the widespread use and popularity of this medicinal plant as a herbal medicine, there is contradictory evidence regarding the safety and toxicity of the plant. The phytochemical profiling of the plant has also been neglected in research. The determination of chemical constituents present in plant material as well as the potential toxicity found in plants are preliminary steps necessary for the discovery and development of novel therapeutic agents with improved efficacy. The aim of this study was to evaluate the cytotoxic and genotoxic potential of crude extracts from the leaves, stems and roots of T. violacea. This was performed in vitro using aqueous and ethanol extracts of the leaves, stems and roots. The aim of the study was achieved by three major objectives; (1) to identify the active phytocompounds present in the leaves, stems and roots, (2) to assess the cytotoxicity using the MTT (3-(4, 5-dimethylthiazolyl-2)-2, 5-diphenyltetrazolium bromide) cell proliferation assay, and (3) to evaluate the genotoxic potential of the leaf, stem and root water extracts using the Allium cepa assay. A total of 14 phytochemicals were each extracted separately with distilled water and 70% ethanol by maceration from the leaves, stem and roots of T. violacea. The results of the qualitative phytochemical analysis showed that pharmacologically active compounds such as tannins, terpenoids, flavonoids, saponins, proteins, steroids, cardiac glycosides, phenols and coumarins were present in some organs of T. violacea. However, phlobatannins, leucoanthocyanins, alkaloids, carbohydrates and anthocyanins were absent in all plant parts. Overall, the leaves of the plant contained more active compounds than those present in the stems and roots when both water and 70% ethanol were used as the extractants. The quantitative phytochemical analysis for the Total Flavonoids Content (TFC) and Total Phenolic Contents (TPC) was also assessed. The water (0.027 mg/g) and 70% ethanol (0.053 mg/g) were most effective in extracting flavonoids from the leaves while the least amounts were obtained from the stems and roots. This observation was similar to the TFC were the water extracts of the leaves were the most effective in extracting phenols followed by the stems and roots. The MTT assay was conducted using two cell lines RAW 264.7 and C2C12. The experiment was conducted in triplicates for the leaf, stem and root extracts (water and ethanol) of T. violacea. The experimental design employed a 23 factorial design where three independent variables (concentration, incubation time and type of extracts) were selected using two levels for each variable (high (+) and low (-)). The results illustrated that both the water and ethanol vi extracts only showed a significant reduction in the number of viable cells at the concentration higher than 250 μg/ml treatment for both RAW 264.7 and C2C12 cells. The ethanol extracts from the leaves, stems and roots were found to be toxic towards the RAW 264.7 cells even at lower concentrations at both 24 and 48 h incubation periods (% cell viability < 50%). The water extracts were non-toxic to RAW 264.7 cells except for the water stem extract which showed toxicity after 48 h incubation (IC50 = 9.475 (4.061 to 23.39)). For the C2C12 cells, the lowest potent toxic concentration was 250 μg/ml for the ethanol extract of the stem after 48 h incubation. Overall, the T. violacea plant extracts were non-toxic as percentage cell viability greater than 50% was noted for both extraction solvents in all the plant parts of T. violacea. No cytotoxic activity was observed in all T. violacea plant parts with the C2C12 cell line (IC50 > 30 μg/ml). For the Allium cepa assay, only the water crude extracts of the leaves, stems and roots of T. violacea were used. A similar trend of potent genotoxic activity in the water stem extracts compared to the leaf and root extracts at the concentration ranges studied. Similar to the MTT assay, it is clear from the study that at higher concentrations, the water crude extracts from the leaves, stems and roots of T. violacea is toxic. From this study, it can be concluded that the extraction of compounds using water is more efficient than using ethanol. Overall, the T. violacea leaf extracts extracted the most phytocompounds and showed the highest percentage of viable cells as well as desirable IC50 values. However, preparation of herbal remedies using T. violacea plant extracts should be done with caution due to their possible genotoxic and cytotoxic potential at higher concentrations. This study raises a need to further conduct in vivo cytogenetic studies to ascertain the possible toxic effects of T. violacea crude extracts.
Ellery, Julie. "The biology, ecology and pathology of potential fungal canker and leaf blight pathogen Auambalaria species on leaves and stems of Corymbia calophylla". Thesis, Ellery, Julie (2005) The biology, ecology and pathology of potential fungal canker and leaf blight pathogen Auambalaria species on leaves and stems of Corymbia calophylla. Honours thesis, Murdoch University, 2005. https://researchrepository.murdoch.edu.au/id/eprint/32599/.
Bujor, Oana-Crina. "Extraction, identification and antioxidant activity of the phenolic secondary metabolites isolated from the leaves, stems and fruits of two shrubs of the Ericaceae family". Thesis, Avignon, 2016. http://www.theses.fr/2016AVIG0261/document.
Bilberry and lingonberry, two shrubs of the Ericaceae family, are consumed as food, beverage and dietary supplements due to their nutritional value and richness in antioxidant polyphenols. In plants, the quality and quantity of phenolic compounds are influenced by the parts of the plant to be used. In particular, plant phenolic compounds provide antioxidant activity in the protection of dietary lipids from oxidation and the gastric compartment has been proposed as a major site for diet-related oxidative stress. The aim of this thesis is to simultaneously assess the seasonal variations of phenolic compounds in leaves, stems, and fruits of bilberry and lingonberry extracts, as well as their antioxidant activity. For this study, aqueous and hydroethanolic (only fruits) extracts of bilberry and lingonberry samples collected in May, July and September during the years 2013-2014 were obtained under microwave-assisted extraction.In bilberry extracts, qualitative and quantitative analyses by UPLC/MS showed the presence of caffeoyl derivatives, p-coumaroyl derivatives, and flavonol glycosides in leaves whereas in stems, flavanol oligomers were additionally identified in significant amounts. Thioacidolysis revealed low degrees of polymerization (2-4) and (-)-epicatechin as the main flavan-3-ol unit. The sum of the phenolic compounds by UPLC was highly correlated with the Total Polyphenol Content and the antioxidant activity in the DPPH test for all the extracts except those of May leaves. The latter were relatively richer in p-coumaric acid derivatives. Seasonal effects were more marked for leaves which exhibited higher antioxidant activities and phenolic contents in July and September when these parameters were maximum in July for bilberry stems. The harvest period can be refined based on the desired phenolic structures. For lingonberry, the predominant presence of monomers and oligomers of flavanols and quercetin glycosides was found in all the morphological parts. Proanthocyanidins contain (+)-catechin and (-)-epicatechin as both extension and terminal units. The sum of the phenolic compounds by UPLC was less correlated with the Total Polyphenol Content and the antioxidant activity in the DPPH test than in bilberry. Furthermore, the total phenolic content (Folin method, UPLC) showed a slight but significant increase from May to September for both leaves and stems. This increase was confirmed for the antioxidant activity by the DPPH test for both leaves and stems in 2014.The antioxidant activity of bilberry and lingonberry extracts against lipid oxidation (formation of lipid-derived conjugated dienes) was evaluated under in vitro simulated digestion conditions. Firstly, the inhibition of lipid oxidation was performed using sunflower oil-in-water emulsions stabilized by bovine serum albumin (BSA) or egg yolk phospholipids (PL), both emulsifiers mimicking dietary components. Oxidation was initiated by metmyoglobin, a form of dietary iron from red meat. In both emulsion models, aqueous extracts from stems and leaves and the hydroethanolic fruit extract of bilberry proved to be more efficient inhibitors of lipid oxidation in the early phase of digestion (pH 5) than during the second phase (pH 3). Secondly, a bilberry leaf extract was tested in the inhibition of lipid oxidation in a complete static in vitro digestion model (oral, gastric and intestinal phases). The fast lipid oxidation in the gastric step (BSA and PL systems) and the slower lipid oxidation in the intestinal step (PL system) were totally inhibited by the bilberry leaf extract
Bensaid, Aicha. "Propriétés anti-oxydants, anti-inflammatoires et antispasmodiques d’Ocimum basilicum". Electronic Thesis or Diss., Université de Montpellier (2022-....), 2022. http://www.theses.fr/2022UMONG091.
Basil Ocimum basilicum L is an herbaceous, aromatic, and food crop, which is used fresh or processed in some culinary preparations, thus in traditional medicine. The different parts of this plant present very important biological properties for human health due to their richness in bioactive compounds. The objective of this work is based on the differential characterization of the phytochemical profile of the stems and leaves of Ocimum basilicum and the evaluation of its antioxidant, anti-inflammatory, and antispasmodic properties. The basil extracts showed different phytochemical profiles, and the evaluation of these antioxidant effects by DPPH and ORAC assay showed that the ethanolic extracts had a higher activity compared to the aqueous extracts. The study of the anti-inflammatory effects of ethanolic extracts of basil stems and leaves in vitro in a macrophage J774 cell model stimulated by LPS/IFNγ showed that both extracts had an inhibitory effect on the production of inflammatory mediators (nitric oxide, interlukin-6, prostaglandin E2, Monocyte chemoattractant protein-1), but increased the production of the pro-inflammatory cytokine TNFα (Tumour necrosis factor-alpha). Subsequently, the aqueous extracts showed a relaxing effect on rat intestinal smooth muscle. The results of this study indicated that both parts of basil leaves and stems have interesting biological effects that can be valorized in terms of nutrition and health
Saad, Houda. "Développement de bio-composites à base de fibres végétales et de colles écologiques". Thesis, Pau, 2013. http://www.theses.fr/2013PAUU3039/document.
The integration of natural cellulosic fibers from annual plants and agricultural residues and agro-industrial materials in the development of composite structures and the development of new bio-based adhesives, are now a research field with growing interest. The thesis was conducted within the framework of "Eco-panels" program, which its two main objectives were firstly, to enhance plant fibers of Tunisian origin as alfa, rush and palm leaflets and then to evaluate the potential of Tunisian plant species whose bark is rich in tannins (pomegranate fruit, sumac roots and Aleppo pine trunk). The characterization studies of fibers showed that their densities are less than 1. The calculation of the fiber saturation point (FSP) shows values mostly between 60 and 100 %. We were also able to characterize the impregnation kinetics of water for each of these fibers. The impregnation stabilizes after 24 h of immersion. Rich in minerals (concentrations greater than 1 %), the fibers showed levels of cellulose, lignin and hemicellulose comparable to those generally encountered with wood fibers. The thermogravimetric analysis (TGA) shows that the plant matrices are thermally stable for temperatures below 200 ° C. The colorimetric assay of the polyphenolic composition of tanniferous matrices, the infrared analysis and the structural study of the tannins extract, as well as the calculation of "Stiasny number" show the high content in hydrolysable tannins for pomegranate barks and richness of Aleppo pine trunk barks and sumac roots barks in condensed tannins. The study by TGA of the thermal properties of tannins extracts shows that Aleppo pine and sumac tannins are thermally more stable than those of pomegranate. The formulation made from hexamine and Aleppo pine tannins has the greatest elasticity modulus. While the formulation prepared from pomegranate tannins forms the least dense network. These results were confirmed by the study of the shear strength. The study conducted on fiber-plaster composites (implementation and physico-mechanical characterization of composites) showed that local fiber could be an alternative to imported fibers used currently. A first characterization of the thermal conductivity of insulation panels made from local plant fibers and tannins adhesives shows an average conductivity of 0,106 W / Km
Neumann, John A. P. "Variability in the relationship between leaf area and selected stem measures in Douglas fir". Thesis, University of British Columbia, 1990. http://hdl.handle.net/2429/28819.
Forestry, Faculty of
Graduate
Lechthaler, Silvia. "The hydraulic architecture of the plants: study of the allometric relations in stem and leaves". Doctoral thesis, Università degli studi di Padova, 2019. http://hdl.handle.net/11577/3426838.
Lo xilema nelle piante è formato da cellule morte interconnesse che consentono il flusso di acqua dalle radici alle foglie. L'ascesa della linfa è principalmente passiva ed è guidata dall'evaporazione dell'acqua dalle pareti cellulari del mesofillo nella foglia. L'evaporazione dell'acqua genera un'aspirazione capillare sui menischi a livello dei micro-pori delle pareti cellulari, causando una pressione idrostatica negativa che si propaga lungo la colonna d'acqua nello xilema. A causa dell’aumento in altezza delle piante, la lunghezza del percorso idrico aumenta progressivamente ponendo la domanda se la resistenza idraulica aumenta di conseguenza. Vi è evidenza che le piante hanno evoluto strutture xilematiche che compensano il possibile aumento della resistenza idraulica imposta dall'aumento della lunghezza del percorso, come ad esempio l'allargamento dei condotti dalla punta alla base. L’allargamento dei condotti è stato osservato in diverse specie, sia angiosperme sia conifere, dimostrando che il grado di allargamento dalla punta alla base dello stelo è molto simile tra le specie, o in altre parole, che le piante convergono verso una struttura xilema universale. Tuttavia, restano da chiarire diversi punti sull'architettura idraulica delle piante. Un punto largamente dibattuto è se tratti anatomici dello xilema (ad esempio la dimensione assoluta delle cellule) cambiano con le condizioni climatiche. Inoltre, se e come i condotti che si allargano nello stelo possano influenzare l'anatomia dello xilema della foglia non è ancora completamente compreso. Il progetto di questo dottorato mira ad ampliare la nostra comprensione delle relazioni allometriche nello xilema delle foglie e del fusto, considerando come le condizioni ambientali e l'altezza della pianta possano influenzare l'architettura idraulica del sistema di trasporto dell'acqua. Uno studio metodologico (Studio 1) è stato eseguito sul tessuto xilematico di fusti di alberi di acacia cresciuti in diverse condizioni di disponibilità idrica. Il risultato principale è stato che, una volta che i dati anatomici sono stati standardizzati per l'altezza dell'albero, l'architettura idraulica dello xilema non è cambiata in relazione alle condizioni ambientali. Sono stati eseguiti due studi sull'architettura idraulica delle foglie. L'obiettivo principale degli studi riguardava i tratti anatomici dei condotti dello xilema in relazione alle dimensioni della foglia e / o alla posizione nella chioma dell'albero (altezza dalla base del fusto). Dai risultati si evince che i tratti dello xilema si ridimensionano in base all'area fogliare indipendentemente dalla posizione nella chioma (Studio 2). Un'analisi fine della nervatura principale della foglia ha mostrato una rigida architettura idraulica e la coordinazione dei tessuti (Studio 3), ben predetta dalla distanza dalla punta della foglia. Entrambi gli studi hanno dimostrato che le dimensioni delle vene terminali sono conservate tra le foglie e all'interno della stessa foglia, suggerendo che l'architettura idraulica dello xilema si è evoluta in modo da garantire distribuzione omogenea delle resistenze idrauliche (e quindi dell'acqua) tra le foglie e lungo la lamina fogliare. Infine, abbiamo implementato i dati anatomici di fusto e foglia in un modello idraulico per stimare la distribuzione delle resistenze lungo il percorso idraulico per valutare in che modo l'anatomia del sistema di trasporto influisca sulla fisiologia dell'intero albero (Studio 4). Questa tesi ha evidenziato che la lunghezza del percorso (vale a dire l'altezza della pianta e le dimensioni della foglia) è il fattore principale che influenza l'architettura idraulica dell'albero. La dimensione del condotto sia nel fusto che nella foglia è determinata dalla distanza dalle parti terminali, rispettivamente l'apice del fusto o la punta della foglia. Le condizioni climatiche risultano avere un effetto marginale (non significativo) sui tratti anatomici del fusto e nella foglia, le dimensioni dei condotti dello xilema sono statisticamente indipendenti rispetto alle variazioni nelle dimensioni della pianta. Questa rigida architettura idraulica dell'albero, dal fusto alla foglia, consente di minimizzare l'effetto della lunghezza del percorso sulla resistenza idraulica, confinando quasi l'intero gradiente del potenziale idrico all'interno delle foglie.
Onyekwelu, Cindy. "WHY DO UNDERREPRESENTED MINORITIES LEAVE SCIENCE AND ENGINEERING?" Scholarship @ Claremont, 2018. http://scholarship.claremont.edu/pitzer_theses/89.
Sublette, Heidi. "An effective model of developing teacher leaders in STEM education". Thesis, Pepperdine University, 2013. http://pqdtopen.proquest.com/#viewpdf?dispub=3600294.
In the last 5 years, industries have begun to recognize a growing gap in the production of college graduates in areas of STEM. Researchers in various industries believe this gap will create a significant loss of competitive edge in the STEM fields, which will leave the United States pursuing STEM graduates from foreign countries and may ultimately leave the US behind in the industry of science, technology and innovation. This qualitative study analyzes the value and impact of STEM teacher leaders in secondary education. A phenomenological study was conducted with 10 secondary school science and math teacher leaders in order to gain a better understanding of teacher leaders' perceptions, classroom practices and the role of a STEM teacher leader. This study addresses the following research questions: 1) What attributes define effective STEM teacher leaders, according to teacher leaders who have completed the Center for Math and Science Teaching system? 2) What success strategies, among teacher leaders of the Center for Math and Science Teaching program, have enabled further development of teacher leadership? 3) What is the best model in developing teacher leaders, according to literature from 2005 to present? 4) What is an optimal model of developing STEM (science, technology, engineering, and math) teacher leaders within secondary education? This research aims to explore teacher leaders' perceptions of their role as a teacher leader based on strategies learned from CMAST and past experiences. Findings from this study provide critical data for making informed decisions on including important elements when implementing an effective STEM teacher leader system or program, and the impact it can create on science and math teaching and learning in secondary education. The investigator concludes this study with the development of a STEM teacher leader model that merges these findings with existing research.
Filho, Sérgio Gil de Toledo. "Avaliação da dinâmica da população de microrganismos em plantas de cana-de-açúcar IAC (93-3046)". Universidade de São Paulo, 2010. http://www.teses.usp.br/teses/disponiveis/11/11139/tde-22102010-083440/.
The numbe of microbial species in forages during the ensiling is responsible for the silage fermentation, and the numbeof colony forming units (cfu) changes during the crop cycle and environmental conditions. It suggests that the initial microbial profile strongly influences the effectiveness of additives used in the process. In this context, we propose three trials to characterize the microbial population in plants of sugarcane. The first trial evaluated the microbial population in plants of sugarcane by the technique of pour plating. The treatment consisted of two levels of fertilization (NPK and NPK associated with solid manure - 120kg N / ha) applied immediately after sugarcane was harvested by hand. The objective was quantify the number of lactic acid bacteria, yeasts and molds, as well as relating their frequencies with environmental effects, fertilization and stage of maturation, with samples taken at 10, 12, 14 and 18 months, corresponding to the months of March, May, July and November 2009. The second trial measured the biometric variables, morphological, the accumulation of dry matter and nutrients in sugarcane subjected the sources of fertilization, as mensioned. The third trial performed chemical assessments of sugarcane subjected to the sources of fertilization. The trials consisted of a completely randomized design with six blocks sub-divided into two plots. Data were analyzed by the procedure Proc Mixed and Proc NLIN of SAS program. There was no effect of treatment in any trial. The fresh yield ranged from 162 to 188tGM/ha which can be considered high. The number of green leaves was increased from 9.5 to 10 to 10 to 18, which is expected, since there is an increase of plant biomass across the time. The same was observed for dead leaves, from about 0 leaves per plant up to 3 leaves. The weight of the leaves was also increased. The weight and length of the stem increased from March to May, and became more intensive from July with increasing rainfall. However, during the dry season (May - July) there was a decreased growing rate.The sugarcane oBrix was 10 at 10 months, 17 oBrix at 12 months and 20oBrix to 20 months. The maturity index increased, from 33.46 to 10 months reaching 88.5 at 18 months. At 12 months the sugarcane showed dry matter content of 24% and 28% at 18 month. The NDF and ADF of the whole plant decreased over time from 10 months (61% and 38.4% NDF and ADF, respectively) for 12 months and remained constant until 18 months (55% and 35 6% NDF and ADF, respectively). A is positive correlation between IVDMD and oBrix was observed, and the equation, IVDMD = 41.35 + oBrix, with R2 = 0.73 and P <0.01 is an important tool to estimate IVDMD. Over time, the counts of lactic acid bacteria were increased. In general, all plant fractions showed similar counts, starting from 4 log cfu/gGM to 10 months and reaching about 5.5 log cfu/gGM to 18 months. At 10 months the whole plant sugarcane had yeast count of 4 log cfu/gGM remaining constant until 18 months, when it reached 5.7 log cfu / g MV. The source of fertilizer, whether chemical or organic, does not interfere in the population of microorganisms, however, varies depending on the experimental period and climatic conditions.
Бодня, Оксана Юріївна. "Мутаційна мінливість індукована хімічними мутагенами в М2 у редьки сорту Факел". Магістерська робота, ЗНУ, 2020. https://dspace.znu.edu.ua/jspui/handle/12345/1399.
UA : Дипломна робота виконана на 75 сторінки друкованого тексту, містить 2 таблиці та 9 рисунків. Під час написання роботи було використано 50 літературних джерел, одне з них іноземною мовою. Об'єктом дослідження був сорт редьки олійної Факел, оброблений хімічним мутагеном та його вихідна форма. Актуальність проблеми – шляхом індукованого мутагенезу був отриманий цінний генетичний матеріал у багатьох сільськогосподарських культур. Окрім інших були отримані мутації, що проявляються на ранніх стадіях росту та розвитку, у тому числі з різним проявом на сім'ядольних листках. Ці мутації можуть бути використані як маркерні ознаки в селекції культури. Так як тема стосовно редьки олійної мало досліджена, то дослідження у вказаному напрямку являються необхідними і актуальними. Мета даної роботи полягала у спостереженні та виділенні нових груп мутацій під впливом етилметансульфонату під час проходження основних фаз вегетації культури та встановлення частоти виділених мутацій. В результаті дослідів у другому мутантному поколінні були отримані такі мутації: мутації з порушенням синтезу хлорофілу, мутації сім’ядольних та справжніх листків, мутації структури стебла та гілок, мутації квітки, мутації фізіологічних ознак. У 10 сімей контролю мутаційні зміни не виявлені. Загальна частота виділених мутацій склала 28,2 %. Слід зазначити, що ця частота мутацій є попередньою, оскільки остаточну частоту мутацій у другому мутантному поколінні можна встановити лише після перевірки успадкування виділених мутацій у наступному поколінні. Отже, використання хімічного мутагену етилметансульфонату у концентрації 0,01% було ефективним для одержання мутацій різного типу, у тому числі тих, що виявляються на ранніх стадіях росту та розвитку редьки олійної. У сучасному рослинництві редька олійна є відносно новою культурою, але вже активно починає використовуватись в сільському господарстві. Найбільше поширення культура отримала як сидерат. Але також знайшла своє місце застосування в харчовій промисловості, косметології, фармакології, кулінарії, виробництві біопалива. Тому будь-які досліди, пов’язані з отриманням цінного генетичного матеріалу, являються дуже необхідними. Саме в цьому і є значущість і новизна даної роботи.
EN : The Degree work is completed on 75 pages of printed text, contains 2 tables and 9 figures. During the writing were used 50 literary sources, one of them in a foreign language. The object of the research was a sort of oilseed radish Torch treated with a chemical mutagen and its original form. The topicality of the problem - by induced mutagenesis has been obtained valuable genetic material in many agricultural crops. Among others were obtained mutations that appear themselves in the early stages of growth and development, including various manifestations on cotyledons leaves. These mutations can be used as marker features in culture selection. As the topic of oilseed radish is poorly explored, research in this direction is necessary and relevant. The purpose of this work was to observe and selection new groups of mutations under the influence of ethyl methanesulfonate during the main phases of vegetation. In the second mutant generation as a result of experiments were received the following mutations: mutations with impaired chlorophyll synthesis, mutations of cotyledons leaves and true leaves, mutations of the structure of the stem and branches, mutations of the flower, mutations of physiological features. In 10 control families mutational changes were not detected. The overall frequency of isolated mutations was 28.2%. It should be noted that this mutation frequency is preliminary, because the final mutation frequency in the second generation can be established only after checking the inheritance of isolated mutations in the next generation. Therefore, the use of a chemical mutagen of ethyl methanesulfonate at a concentration of 0.01% was effective for obtaining mutations of various types, including those found in the early stages of growth and development of oil radish. In modern plant growing, oilseed radish is a relatively new crop, but it is already actively used in agriculture. Culture was most widely used as a siderate. But it has also found its application in food, cosmetology, pharmacology, cooking and production of biofuel. Therefore, any experiments related to obtaining valuable genetic material are very necessary. That is the significance and novelty of this work.
Hutchinson, Anna E. "Perceptions of Teacher Leadership: The Influence of Organizational Structure on the Professional Identity of Urban STEM Teacher Leaders". University of Cincinnati / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1581333163812174.
Brown, Arogeanae Ronterria Dinita. "Reframing AgriCULTURAL Experiences, Narratives, and Careers for African American Youth: A Study of Community-based Programs Leaders' Motivations and Educational Space". Thesis, Virginia Tech, 2018. http://hdl.handle.net/10919/84495.
Master of Science in Life Sciences
Bowers, Sharon W. "Supporting Elementary Education In-Service Teachers' Proficiency in Planning STEM-Centric Lessons". Diss., Virginia Tech, 2015. http://hdl.handle.net/10919/64380.
Ed. D.
Sapian, A. S. "How to create a brand for 3 steps? Building successful sales funnels in business". Thesis, Київський національний університет технологій та дизайну, 2019. https://er.knutd.edu.ua/handle/123456789/14356.
Ziller, Michael [Verfasser]. "Overexpression of HoxA9 in CD150- hematopoietic stem cells leads to rapid progression of acute myeloid leukemia / Michael Ziller". Berlin : Medizinische Fakultät Charité - Universitätsmedizin Berlin, 2021. http://d-nb.info/1228859671/34.
Garrett, Dawn. "A quantitative study of STEM goal and role alignment across stakeholder leaders in California| Advocacy for application of a systems solution approach". Thesis, Pepperdine University, 2013. http://pqdtopen.proquest.com/#viewpdf?dispub=3587844.
Both the nation and California are faced with a critical threat to our long term strength and welfare due to an acknowledged deficit in STEM ready students and workers as we head into the 21st century. The STEM workforce gap requires integrated conversations and solutions as it impacts multiple stakeholder groups who do not necessarily fully comprehend each other's needs and challenges. There is a broad consensus that increasing the STEM workforce is critical to the U.S., impacting standard of living, as well as national security in areas such as international competitiveness, combating terrorism and addressing global warming, to name just a few. Historically, the world has looked to the U.S. as the globe's preeminent source of innovation. However, critical indicators have caused industry, educators, policy makers, and communities to take a deeper look at some alarming trends. For example, a U.S. Department of Commerce study noted that the U.S. has made no progress in its competiveness since 1999, and is beginning to lose ground to other countries that are actively building their scientific and technological infrastructures.
This study utilized the literature review to explore the power of applying system's thinking to this complex social problem. In addition, the study quantitatively demonstrated the current state of alignment in California across two key stakeholder group's leaders, industry and education by exploring the following areas: 1. Are the perceptions of two respondent stakeholder leader groups aligned relative to nine identified California STEM goals? 2. Are the perceptions of the assignment of roles across the California STEM stakeholders related to the two respondent group leaders' affiliation? 3. What is the current state of collaboration in California based on the perceptions of the two respondent groups' leaders?
The quantitative research demonstrated alignment of the key stakeholder leaders around what is important relative to the goals of California's STEM workforce gap as well as alignment around which stakeholder leaders should be executing specific tasks. The research also underscored an aligned understanding of the current lack of collaboration that exists across stakeholder leaders in California.
FURIA, SIMONE. "VALUE NOT DUMP". Doctoral thesis, Università degli Studi di Milano, 2013. http://hdl.handle.net/2434/217616.
ABSTRACT Introduction. Repair damaged tissue to prevent postoperative complications and save healthy tissue to ensure good respiratory function are two of the objectives of the thoracic surgeon. Over the years have been introduced in clinical practice numerous synthetic products that are able to simulate the mechanical and physiological characteristics of the damaged tissue, but in the face of high costs, do not always guarantee stable results. The autologous adipose stem cells (ASC) is proposed as a new strategy to promote the repair of tissues after surgery. Research Project. The lipocentrifugated with the ASC has been subjected to a pre-clinical evaluation using in vitro and in vivo assays to test the reparative potential on lung tissue and to clarify the supposed tumorigenic effect of any residual neoplastic. The clinical study was performed on 20 pulmonary metastasectomies performed using last generation laser (wavelength 2010nm). The main endpoints of the study were: 1) the feasibility of pulmonary metastasectomy with Thulium laser (2010nm), 2) incidence of postoperative prolonged air leak (> 7 days) 3) feasibility of the harvesting of stem cells at the level of thoracotomy on the basis the cell count stem 4) impact of this type of procedure on respiratory function. Clinical Results. We had no perioperative death. After removal of lesions located deep in the parenchyma, 4 patients developed prolonged air leaks. In one patient the pleural drain was removed in POD 13 and 3 patients were discharged with a chest tube connected to the valve Heimlich. Redo surgery to improve the aerostasis was not required. One patient developed a hematoma at the site of collection of adipose tissue and 4 cases of fever have been resolved with antibiotic therapy. The mesenchymal stem cells were detected in concentrations> 1% in 13 cases. Age, sex, preoperative chemotherapy and body mass index did not affect the number of stem cells. No significant reduction in terms of lung function was measured after surgery. No synthetic materials were used. Conclusions. Our study shows that the fat tissue collected at the level of the subcutaneous layer of the thoracotomy is a useful source of stem cells. The advantages brought by this technique can be measured in terms of respiratory function. With a median follow-up of 16 months no recurrence was observed at the site of application of centrifuged fat graft.
Bray, Ross. "Evaluating the impacts of a STEM research placement program between a secondary school and a science research institute". Thesis, Queensland University of Technology, 2021. https://eprints.qut.edu.au/212449/1/Ross_Bray_Thesis.pdf.
Lima, Débora Cristina da Silva. "Avaliação das atividades genotóxica e antigenotóxica do extrato etanólico de Lafoensia pacari A. St-Hil em bactérias e camundongos". Universidade Federal de Goiás, 2012. http://repositorio.bc.ufg.br/tede/handle/tede/7410.
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Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq
Lafoensia pacari A. St. Hil. (Lythraceae), popularly known in Brazil as “pacari”, is a species native of Cerrado. In folk medicine, the leaves and stem bark are used to treat cancer and as an anti-inflammatory and cicatrizant agent. Due to the wide use of this plant as a therapeutic resource, the present study evaluated the genotoxic, cytotoxic, antigenotoxic, and anticytotoxic activities of the ethanolic extract from L. pacari stem bark and leaves using the Ames test and the mouse bone marrow micronucleus test. Our results demonstrated that the ethanolic extract from L. pacari leaves, presented no mutagenic activity in bacteria, but presented a mild genotoxicity in the highest concentration at 24 h in mice bone marrow cells. Exhibited moderate cytotoxic effect on bacteria and a mild cytotoxic action in the highest concentration by micronucleus test. The extract showed antimutagenic activity by Ames test and in the micronucleus test demonstrated antigenotoxic action in all concentrations at 24 h, and in the lowest concentration at 48 h. Showed anticytotoxic effect in all concentrations and times tested. In the evaluation of the genotoxic, cytotoxic, antigenotoxic and anticytotoxic activities of the ethanolic extract from L. pacari stem bark, the results demonstrated that the extract exhibited no mutagenic activity in bacteria, however showed a mild genotoxicity in the highest concentration in mice. Exhibited moderate cytotoxic effect in bacteria and a mild cytotoxicity at 24 h by micronucleus test. Showed strong antimutagenic activity by Ames test, as well as antigenotoxic and anticytotoxic activities in the mouse bone marrow micronucleus test, demonstrating to be a strong protective agent against DNA damage.
Lafoensia pacari A. St-Hil, (Lythraceae) popularmente conhecida no Brasil como pacarí, é uma espécie nativa do Cerrado. Na medicina popular, suas folhas e casca do caule são utilizadas para tratar câncer, como um agente cicatrizante e antiinflamatório. Devido à grande utilização dessa planta como recurso terapêutico, o presente trabalho avaliou as atividades genotóxica, citotóxica, antigenotóxica e anticitotóxica do extrato etanólico das folhas e da casca do caule de L. pacari, utilizando o teste de mutagenicidade de Ames e o teste do micronúcleo em medula óssea de camundongos. Nossos resultados demonstraram que o extrato etanólico das folhas de L. pacarí, não apresentou atividade mutagênica em bactérias, mas apresentou uma leve genotoxicidade na concentração mais elevada em células de medula óssea de camundongos no tempo de 24 h. Exibiu efeito citotóxico moderado em bactérias e uma leve ação citotóxica, na concentração mais elevada no teste de micronúcleo. O extrato apresentou atividade antimutagênica pelo teste de Ames e no teste do micronúcleo demonstrou ação antigenotóxica em todas as concentrações no tempo de 24 h e na concentração mais baixa no tempo de 48 h. Apresentou efeito anticitotóxico em todas as concentrações e tempos testados. Na avaliação das atividades genotóxica, citotóxica, antigenotóxica e anticitotóxica do extrato etanólico da casca do caule de L. pacarí os resultados provaram que este extrato não exibiu atividade mutagênica em bactérias, no entanto apresentou uma genotoxicidade fraca na maior concentração em camundongos. Exibiu um efeito citotóxico moderado em bactérias e uma leve citotoxicidade, somente no tempo de 24 h pelo teste de micronúcleo. Apresentou forte atividade antimutagênica pelo teste Ames, bem como atividade antigenotóxica e anticitotoxica no teste de micronúcleo em medula óssea de camundongos, demonstrando ser um forte agente protetor contra danos no DNA.
Makwinya, Noel Mark. "Managing science teachers’ adoption of the 2005 Tanzanian Inquiry and Student-Centred Curriculum: Revealing schoolbased leaders’ practices and achievements". Thesis, Edith Cowan University, Research Online, Perth, Western Australia, 2020. https://ro.ecu.edu.au/theses/2289.
Rakotonandrasana, Jean. "Modélisation de la décharge négative dans les longs intervalles d'air - Application à la foudre". Phd thesis, Ecole Centrale de Lyon, 2008. http://tel.archives-ouvertes.fr/tel-00372671.
Le modèle permet de déterminer les caractéristiques spatio-temporelles de la décharge telles que le courant du leader (canal principal), la charge correspondante, des trajectoires plausibles, sa vitesse instantanée, le gradient de potentiel et le rayon thermique du leader négatif d'électrode, la puissance et l'énergie injectées dans l'intervalle, l'instant et la tension d'amorçage ainsi que l'évolution de l'arc en retour. Il permet également, pour une configuration d'électrodes donnée, de déterminer la tension de claquage U50, constituant ainsi un outil appréciable pour le dimensionnement des structures isolantes. Les résultats issus de ce modèle sont en bon accord avec ceux obtenus expérimentalement.
Un modèle de foudre négatif a été également établi en se basant sur la grande similarité observée entre les grandes étincelles de laboratoire et les décharges atmosphériques. Les caractéristiques obtenues à partir de ce modèle ont été trouvées conformes aux mesures effectuées lors des décharges naturelles. L'environnement électromagnétique associé au précurseur de foudre a été ensuite caractérisé et les champs électriques et magnétiques obtenues sont aussi en bon accord avec celles relevées expérimentalement.
Génevé, Thomas. "Méthodes de diagnostic des piles à combustible". Phd thesis, Toulouse, INPT, 2016. http://oatao.univ-toulouse.fr/15589/1/TGENEVE.pdf.
Cavallin, Mara. "Physiopathologie moléculaire et cellulaire des anomalies du développement du cortex cérébral : le syndrome d'Aicardi WDR81 mutations cause extreme microcephaly and impair mitotic progression in human fibroblasts and Drosophila neural stem cells TLE1, a key player in neurogenesis, a new candidate gene for autosomal recessive postnatal microcephaly Mutations in TBR1 gene leads to cortical malformations and intellectual disability Aicardi syndrome: Exome, genome and RNA-sequencing of a large cohort of 19 patients failed to detect the genetic cause Recurrent RTTN mutation leading to severe microcephaly, polymicrogyria and growth restriction Recurrent KIF2A mutations are responsible for classic lissencephaly Recurrent KIF5C mutation leading to frontal pachygyria without microcephaly Rare ACTG1 variants in fetal microlissencephaly De novo TUBB2B mutation causes fetal akinesia deformation sequence with microlissencephaly: An unusual presentation of tubulinopathy A novel recurrent LIS1 splice site mutation in classic lissencephaly Further refinement of COL4A1 and COL4A2 related cortical malformations Prenatal and postnatal presentations of corpus callosum agenesis with polymicrogyria caused By EGP5 mutation Delineating FOXG1 syndrome from congenital microcephaly to hyperkinetic encephalopathy Delineating FOXG1 syndrome: From congenital microcephaly to hyperkinetic encephalopathy". Thesis, Sorbonne Paris Cité, 2019. https://wo.app.u-paris.fr/cgi-bin/WebObjects/TheseWeb.woa/wa/show?t=2213&f=18201.
Malformations of cortical development (MCD) are a major cause of intellectual disability and drug-resistant epilepsy. Next Generation Sequencing (NGS) has considerably improved the identification of the molecular basis of non-syndromic MCD. However, certain forms, including complex MCD, remain unexplained. My PhD project aimed to improve the understanding of complex MCD using two disorders: Microlissencephaly (MLIS) and Aicardi Syndrome (AIC), the latter associating brain and eye malformations and only reported in girls. Trio Whole Exome Sequencing (WES) performed in 16 MLIS families allowed me to identify and functionally characterize a new MLIS gene, WDR81, in which mutations lead to cell cycle alteration. Moreover, using the same strategy, I was able to identify a pathogenic homozygous variant in TLE1 in a patient from consanguineous family with a postnatal microcephaly, suggestive of a FOXG1-like presentation. Interestingly, TLE1 is a major partner of FOXG1, a gene involved in maintaining the balance between progenitor proliferation and differentiation. In parallel, my work allowed me to redefine the phenotypic spectrum associated with RTTN, EPG5, COL4A1 and COL4A2, TBR1, KIF5C, KIF2A and FOXG1. The second part of my PhD program was aimed at identifying the genetic basis of AIC in an international cohort of 19 patients. After excluding a skewed X chromosome inactivation and the presence of chromosomal rearrangements, I performed WES in trios. The analysis of the data from WES did not allow me to identify any recurrent variants. I therefore tested a new approach combining Whole Genome Sequencing (WGS) and RNA-Sequencing (RNA-Seq) on fibroblast cells. I identified a number of deregulated transcripts implicated in brain and eye development. I compared the results of this analysis with the WGS analysis in order to find variants in these candidate genes. In conclusion, these studies have improved the knowledge of the molecular basis of complex MCD, such as TLE1 in postnatal microcephaly, and revealed the pathogenic mechanisms such as WDR81 in cell cycle progression and EPG5 in endosomes and autophagy. My work has also generated a collection of NGS data (WES, WGS and RNA-Seq) that will be shared in an international consortium to develop new analytical strategies, in particular for the non-coding DNA regions. This novel strategy provides opportunities to improve understanding of the cellular mechanisms involved in brain and eye development
Chen, Chien-Ting, e 陳建廷. "Chemical Constituents of the Leaves and Stems of Gelonium aequoreum". Thesis, 2012. http://ndltd.ncl.edu.tw/handle/00115344314177833181.
高雄醫學大學
天然藥物研究所
100
Gelonium, a genus of shrubs and small trees belonging to the Euphorbiaceae family, is distributed in the tropical and subtropical parts of Asia and Africa. This genus contains about 25 species, but only G. aequoreum is native to Taiwan. We had previously reported the isolation of gelomulide K from G. aequoreum, which acted as a caspase-independent cell death inducing agent that possesses synergic effect with paclitaxel in breast cancer cells and has low toxicity towards normal cells. Treatment with gelomulide K induced PARP-1 hyperactivation, AIF nuclear translocation, and cytoprotective autophagy, together with increased ROS production and decreased cellular GSH levels in MDA-MB-231 cancer cell line. In the present study, the dichloromethane-soluble extract of G. aequoreum leaves was chromatographed using silica gel to obtain gelomulide K (GK) and triterpenoids rich fractions. Bioguided fractionation of the triterpenoids-rich and GK-rich fractions yielded ten compounds, including one lupane-type triterpene: lupeol (1), one taraxerane-type triterpene: taraxerol (2), two oleanane-type triterpenes: germanicol (3), and ??-amyrin (4), one urasane-type triterpene: ??-amyrin (5), two D:C-friedourasane-type triterpenes: bauerenol (6), and multiflorenol (7), one novel triterpene: cyclogelonian-3??-ol (8) one fernane-type triterpene: fernenol (9), and one ent-abietane diterpenoid: gelomulide K (10). Among them, cyclogelonian-3??-ol (8) has a new skeleton of triterpenoid with a 13??,18??-cyclopropane function. The EtOAc and the n-BuOH layers of G. aequoreum stems were also investigated. Chromatographic separation of those layers yielded twenty compounds, including one lupane-type triterpene: lupenone (11), two oleanane-type triterpenes: olean-18-en-3-one (12), and olean-12-en-3-one (13), one urasane-type triterpene: ??-amyrenone (14), two D:C-friedourasane-type triterpenes: D:C-friedours-7-en-3-one (15), and multiflorenone (16), one new triterpene: cyclogelonian-3-one (17), one fernane-type triterpene: fernenone (18), three benzenoid: chrysophanol (19), halorosellin C (20), and baisubenzene (22). Among these isolates, 17 possesses a new chemical skeleton as that of compound 8, and compounds 20 and 22 are new. The biological activities of the isolates are currently under investigation.
Chen, Ting-ting, e 陳亭亭. "Studies on the Chemical Constituents in the Leaves and Stems of Mucuna macrocarpa WALLICH". Thesis, 2005. http://ndltd.ncl.edu.tw/handle/38427495344257098828.
中國醫藥大學
中國藥學研究所
93
Mucuna macrocarpa WALLICH is a native plant of Taiwan belonging to the Leguminosae family. It is a folk medicine being used for blood circulation, activating meridians and collaterals, moisten dryness, release stagnated lung-energy. This plant was also used in Taiwan folk medicine for diabetes mellitus. In the assay for DPPH scavenging effect, the fractions of crude extract, water layer, n-butanol layer, ethyl acetate layer and precipitates showed good free radical scavenging effects. In the phytochemical study, five compounds were isolated from M. macrocarpa and were identified as the mixture of -sitosterol and stigmasterol (H-1), betulin (C-1), medicarpin (E-1), sucrose (B-1), D-pinitol (B-2), -sitosterol-3-O--D-glucoside (N-1) and tetracosanoic acid 2,3-dihydroxypropyl ester (N-2)。 We also carried out the HPLC quantitative analysis of genistein in M. macrocarpa , in order to find out the composition of M. macrocarpa and its dependence of the efficiency. Content percentage of genistein was 0.001% in M. macrocarpa. This may suggest that the activities of M. macrocarpa was resulted together from many kinds of flavonoids and other constituents. Since this plant is rather common in Taiwan, further study and investigation of its active constituents may prove its potential biological activities and medicinal values.
Chung, Yu-ling, e 鍾玉玲. "Comparison of Antioxidative Activity of Crude Extracts from Leaves, Stems and Fruits of Morinda citrifolia (Noni)". Thesis, 2004. http://ndltd.ncl.edu.tw/handle/56447932507810300280.
嘉南藥理科技大學
生物科技研究所
92
Morinda citrifolia(Rubiaceae), commonly known as Noni, is a plant typically found in the Hawaiian, Tahitian and tropical Asia. The bark, stem, roots, leaves, and fruits have been used traditionally as a folk remedy for many diseases including diabetes, hypertension, and cancer. The first purpose of this study was focused on the antioxidative properties of various crude extracts from leaves, stems and fruits of Noni. With the results of antioxidative analysis, the optimal material of Noni plant and extract condition would be defined. Hot water (80℃), 50% aqueous or absolute ethanol, ethyl acetate and supercritical fluid carbon dioxide (SF-CO2) were used as solvents to extract. The antioxidative activity of crude extracts were measured by Trolox equivalent antioxidant capacity (TEAC) assay, the reducing power assay, the bleaching of 2,2-diphenyl-1-picrylhydrazyl hydrate (DPPH) free radical, the scavenging ability of reactive oxygen species (superoxide ion, hydroxyl radical and hydrogen peroxides) and the chelating activity on ferrous ions. The results suggested that antioxidative activity of Noni’s extracts might be due to both polar and non-polar compounds. Hot water and 50 % aqueous ethanol extracts from leaves and stems exhibited higher chelating activity on ferrous ions. Ethyl acetate extracts from leaves showed the highest scavenging ability of superoxide ion, and SF-CO2(1500 psi)extracts from leaves displayed significantly the scavenging ability of hydrogen peroxides. On the other hand, the absolute ethanol extracts of Noni’s leaves and green stems, and the SF-CO2 (3500 psi) extracts of brown stems had higher scavenging ability to hydroxyl free radical. However, fruits extracts were showed very poor as antioxidants. To sum up, leaves of Noni exhibited higher and variety of antioxidative activity, which is comparable to that of both stems and fruits. Noni leaf is worth further research in purification and identification of active compounds. As for extraction condition, ethanol extracts had higher total antioxidative activity, especially in scavenging of hydroxyl radical. The second purpose was to study the relationship between the antioxidative activities and chemical constituents in the crude extracts of Noni. The data showed that ethanolic extracts of Noni’s leaves had higher total polyphenolic and flavonoid contents and revealed that these compounds played a part in antioxidative activities. However, SF-CO2 extraction of Noni generally had lower total polyphenolic contents. The third study was to prove the Noni’s extracts in the protection ability of biological cell membrane and DNA which were attacted by oxidative damage. The results indicated that the absolute ethanol extracts of Noni’s leaves display significantly the inhibition ability of lipid peroxidation of microsomes from LYD pig liver. The scavenging mechanism of the absolute ethanol extracts of Noni’s leaves might have relation with hydroxyl radical. The antioxidant components might be attributed to higher content of polyphenolic compounds. On the other hand, the hot water and 50% ethanolic extracts of Noni’s leaves display the better protection ability from hydroxyl radical-induced, DNA damage in human lymphocyte without cell membrane. The antioxidant mechanism may be attributed to a strong metal-chelating ability and their effectiveness as good scavengers of hydroxyl radicals. By contrast, the absolute ethanol and ethyl acetate extracts of Noni’s leaves showed the pro-oxidative activity in the higher dosage extracts (10-100 μg/mL). The higher reducing power, which reduced the ferric ion to ferrous ion, appeared to be responsible for the pro-oxidative activity of the absolute ethanol and ethyl acetate extracts of Noni’s leaves.
Wang, Yao-Ting, e 王耀霆. "Studies on the Bioactive Cucurbitane-Type Triterpenoids and Saponins from the Stems and Leaves of Momordica chanrantia". Thesis, 2018. http://ndltd.ncl.edu.tw/handle/uh98bu.
國立高雄大學
生命科學系碩士班
106
Momordica charantia, belonging to the genus Momordica (Cucurbitaceae), is an annual herbaceous plant originated in tropical areas in Asia. It is widely grown and used in Southeast Asia, China and Taiwan. It tastes extremely bitter, and possesses the traits of cool natured and functions of relieving summer-heat, clearing liver, improving vision and detoxifying. It has been proved that bitter melon exhibits many bioactivities, including anti-diabetic, anti- bacterial, antiviral and anti-cancer activities.The purpose of this study is looking for the new bioactive compounds from the stems and leaves of Momordica charantia. Chromatographic separation of the EtOAc extract of M. charantia using Si-60, ODS, HW40F columns and semi-preparative reverse-phase C18 HPLC resulted in the purification of 25 compounds, comprising twelve new triterpenoids 1–12, designated as 3β-hydroxy-9α-hydroperoxy-19- norcucurbita-5,24-dienyl-7β,23R-diacetate (1), 3β,7β-dihydroxycucurbita-5,24-dien-19-al (2), (23E) 3β,7β-dihydroxycucurbita-5,23-dien-19-al (3), (19R,23E) 5β,19-epoxy-25-hydro- peroxy-19-methoxycucurbita-6,23-dien-3β-ol (4), (19S,23E) 5β,19-epoxy-25-hydroperoxy- 19-methoxycucurbita-6,23-dien-3β-ol (5), (19R) 5β,19-epoxy-19-methoxycucurbita-6,24- dien-3β-ol (6), (19S) 5β,19-epoxy-19-methoxycucurbita-6,24-dien-3β-ol (7), (19R, 23E) 5β,19-epoxy-19-methoxycucurbita-6,23-dien-3β-ol (8), (19S,23E) 5β,19-epoxy-19-methoxy- cucurbita-6,23-dien-3β-ol (9), (19R) 5β,19-epoxy-19-methoxycucurbita-6-en-3β-ol (10), (23E) 3β-hydroxycucurbita-6,23-dien-5β,19-olide (11) and (19S,23R) 5β,19-epoxy- 19-methoxycucurbita-6-en-3β,23-diol (12), together with thirteen known compounds 13–25. The structures of these isolated metabolites were determined on the basis of their spectroscopic data including, NMR, ESIMS and IR data as well as comparison of the physical and spectroscopic data with those of the related known compounds. The in vitro cytotoxicity against triple negative breast cancer cell lines (MDA-MB-231) of all isolates were evaluated. Compounds 2, 3, 9, 12, 15 and 16 showed good cytotoxicity against MDA-MB-231 with IC50 values of 4.6, 8.2, 4.7, 9.5, 8.8 and 9.5 μM, respectively.
Nisoli, Cristiano. "Leaves and stems, rotons and solitons, magnets and arrays, one ground state lost, many found, and two fields". 2007. http://www.etda.libraries.psu.edu/theses/approved/WorldWideIndex/ETD-1851/index.html.
Mbugua, David M. "Effect of maturity on rumen degradation of tropical and temperate forage cell wall polysaccharides from leaves and stems". Thesis, 1993. http://hdl.handle.net/2429/2416.
Huang, Tsung-Hsien, e 黃宗賢. "Studies on the Constituents and Their Antiplatelet and Anti- inflammatory Activities from the Stems and Leaves of Pogostemon cablin". Thesis, 1996. http://ndltd.ncl.edu.tw/handle/67911912168537548229.
中國醫藥學院
藥物化學研究所
84
Six known compound: carvacrol (Ⅰ), mixture of α-amyrin and β-amyrin (Ⅱ), 4',5-dihydroxy-6,7-dimethoxyflavone (Ⅲ), 4',5,7-trihydroxy-3'-methoxy-flavone (Ⅳ), methyl caffeate (Ⅴ) and 5-hydroxy-6,7-dimethoxy-4'-O-β-D-glucoside (Ⅵ) have been isolated from the n-hexane, chloroform and ethyl acetate fractions of the methanolic crude extract. And, these compounds are isolated for the first time from the herb. The biological activities of carvacrol, mixture of α-amyrin and β-amyrin, 4',5-dihydroxy-6,7-dimethoxyflavone, methyl caffeate and 5-hydroxy-6,7-dimethoxy-flavone-4'-O-β-D-glucoside have been evaluated.The result shows that AA and collagen-induced platelet aggregation couldbe inhibited strongly by carvacrol and methyl caffeate, and 4',5-dihydroxy-6,7-dimethoxy-flavone-4'-O-β-D- glucoside exhibited the anti-inflammatoryactivity.
Wu, Chin-Yi, e 吳致怡. "Antimicrobial activities and distribution of the carvacrol and thymol in roots ,stems and leaves of Plectranthus amboinicus (Lour.) Spreng". Thesis, 2011. http://ndltd.ncl.edu.tw/handle/85533669892228638685.
國立東華大學
生命科學系
99
Plecteanthus amboinicus is a Lamiaceae perennial herbal plant.It contains some bioactive substances based on several researches,mainly focusing on carvacrol and thymol, for its anti-inflannatory and analgesic activities. This thesis study intented to determine the distribution of carvacrol and thymol in P. amboinicus.Assay of carvacrol and thymol in different parts of P. amboinicus,such as roots, stems and leaves, by HPLC (high-performance liquid chromatography) with the comparison between dried and fresh samples showing a significant difference in their distribution. The results indicated both compounds in leaves were more than those in roots and stems with or without dessication. Analysis of extracts from the P. amboinicus for its antimicrobial activities indicated P. amboinicus extracts did not inhibit the growth of E.coli KRX,but inhibited the growth of Arthrobacter ilicis D50. The results showed that the root extract had the highest inhibition activity.
Lo, Wen-Li, e 羅文利. "Studies on the Chemical Constituents and Biological Activities of the Mixture of Roots and Stems and Leaves of Euchresta formosana". Thesis, 2003. http://ndltd.ncl.edu.tw/handle/wsa264.
高雄醫學大學
藥學研究所
91
Euchresta formosana (Hayata) Ohwi (Leguminosae) is an evergreen and perennial shrub occurring in shady and humid places, especially distributed in Taiwan, Java, and Philippines. The roots of this plant have been used in folk medicine as a pain killer, particularly for the throat and snake wounds in Taiwan. As a part of our research on the biologically active components from Chinese medicinal plants, the roots and leaves of E. formosana were chosen to be investigated. Forty four compounds including eighteen coumaronochromones 、euchretins A-N (1-14), formosanatins A-D (15-18)]; two isoflavones [formononetin (27), retusin 8-methyl ether (33)]; one flavonol [quercetin (35)]; nine flavanones [euchrestaflavanones A-C (36-38), glabrol (39), euchrenones a1-a2 (40-41), euchrenone a11 (42), euchrenones a16-a17 (43-44)]; two pterocarpan [maackiain (45), trifolirhizin (46)]; two lupin alkaloids [(-)-cytisine (48), (+)-matrine (49)]; one cyclohex-2-en-1-one [blumenol A (51)]; and three benzenoids [vanillin (52), p-hydroxybenzoic acid (53), 3-(4-hydroxy-3-methoxyphenyl)-acrylic acid octadecyl ester (54)]; one coumestan [medicagol (55)]; one lignan [(+)-syringaresinol (56)], and four steroids [-sitosteryl D-glucoside (57), stigmasteryl D-glucoside (58), -sitosterol (59), and stigmasterol (60)] were isolated from the mixture of roots and stems of E. formosana. Seven coumaronochromones [euchretin A (1), euchretin C (3), euchretins F-I (6-9), euchretin N (14)]; sixteen isoflavones [tectorigenin (19), genistein (20), 7-hydroxy-3-(3- hydroxy-4-methoxyphenyl)chromen-4-one (21), biochanin A (22), 5,7,8-trihydroxy-3-(4-methoxyphenyl)chromen-4-one (23), euchrenones b1-b2 (24-25), flemiphyllin (26), formononetin (27), 6,7,4'- trihydroxyisoflavone (28), daidzein (29), 7-methoxy-2',4'- dihydroxyisoflavone (30), 3-(3,4-dimethoxyphenyl)-7,8-dihydroxy- chromon-4-one (31), 2'-hydroxylgenistein (32), retusin 8-methyl ether (33), euchrenone b16 (34)]; one flavonol [quercetin (35)]; two pterocarpans [maackiain (45), 2-methoxymaackiain (47)]; one chlorophyll [pheophytin-a (50)]; one cyclohex-2-en-1-one [blumenol A (51)]; two benzenoids [vanillin (52), p-hydroxybenzoic acid (53), 3-(4-hydroxy-3-methoxyphenyl)-acrylic acid octadecyl ester (54)]; one coumestan [medicagol (55)], and four steroids [-sitosteryl D-glucoside (57), stigmasteryl D-glucoside (58), -sitosterol (59), and stigmasterol (60)] from the leaves of E. formosana, had been isolated and characterized by spectral data and chemical related derivatives. Among these 60 compounds, 10-18 and 43-44 are new compounds. Among them, 6-9, 19-32, 34-35, 40-41, 46, 48-54, and 56-58, 60 are isolated for the first time from this plant. On antitumor bioassay, compounds 1, 10, and 13 were demonstrated to have moderate cytotoxicity against 59T cell line (human hepatoma cell, 52.0% , 87.5%, and 71.5% inhibition at the concentration of 10 μg/ml), and compound 10 was also found to be slightly active against SCM-1 cell line (stomach adencarcinoma cell, 53.0% inhibition at the concentration of 10 μg/ml). The rest of compounds exhibited no cytotoxic effect to Hone-1 (nasopharyngeal carcinoma), DLD1(human colon cancer cell), AGS (human gastric cancer cell), SKHep1 (human hepatocellular carcinoma cell), HepG2 (human hepatocellular carcinoma cell) and NUGC (human gastric carcinoma cell ) cell lines. On anti-HIV bioassay, compounds 13, 17, and 26 inhibited HIV replication in H9 lymphocyte cells with EC50 values of < 0.1, < 0.1, and 0.627μg/mL and therapeutic indexes (TI) of > 2.22, > 2.18, and 3.90, respectively. The biological evaluation of the flavonoids from this plant doesn’t demonstrate powerful effect with respect to their anti-HIV activities. On antiplatelet aggregation bioassay, compounds 19 (100μM) showed complete inhibition and 21 displayed strong effects toward the platelet aggregation induced by AA and collagen. Only compounds 20 and 28 (100μM) completely inhibited the collagen-induced platelet aggregation. Compound 6 (100μM) also displayed significant inhibition of the platelet aggregation induced by AA, collagen, especially the action induced by PAF. Compounds 25, 27, 45, and 50 (100μM) were remarkable inhibitors of platelet aggregation induced by collagen. Compounds 6, 19, and 21 was the most effective antiplatelet aggregation compounds. From the results obtained, the following structure-activity relationships can be drawn in terms of antiplatelet effects: 1. In general, isoflavones from this plant are significantly active against AA- and collagen-induced aggregation, while compounds of other types are not. 2. Aspirin is a cyclooxygenase inhibitor, and can prevent AA- or collagen- induced platelet aggregation except that caused by other inducers. Meanwhile, compound 19 exhibited the same inhibitory pattern as aspirin on platelet aggregation induced by AA- and collagen. Thus, the mechanism(s) of action for 19 may be the same as aspirin. However, the precise mechanism requires further investigation.
Marques, Mário Pedro da Silva. "Monitoring of ripening-derived composition and morphology modifications in Arbutus unedo L. fruits, and characterization of vitrified tissues". Master's thesis, 2019. http://hdl.handle.net/10316/88099.
A familía Ericaceae é constítuida por várias espécies economicamente importantes, tais como as pertencentes ao género Rhododendron and Vaccinium. Entre elas, o arbusto mediterrânico Arbutus unedo L. destaca-se do ponto de vista pomológico e ornamental. Para aprofundar o conhecimento sobre esta espécie, analisaram-se as alterações morfológicas e composicionais que ocorrem na ontogenia dos frutos, com o objetivo de identificar fatores e eventos relacionados com a sua maturação. Deste modo, os resultados da execução de FTIR revelaram alterações ao nível dos polissacarídeos estruturais da parede celular, entre frutos imaturos e maduros. Investigações espetroscópicas adicionais com biomassa intacta dos frutos, revelaram que existem variações composicionais, principalmente decorrentes de polissacarídeos da matriz, tais como as pectinas e hemicelulloses, e também celulose. No decorrer da maturação verificou-se também um aumento no teor de sólidos solúveis totais (˚Brix), e um decréscimo na acidez dos frutos. Por outro lado, a degradação de açúcares estruturais que advém da hidrólise e/ou do processo oxidativo, resulta num decréscimo acentuado da firmeza dos frutos, que leva ao seu amolecimento, e também a variações do seu diâmetro polar e equatorial. Além disso, traçou-se um perfil fenólico preliminar dos frutos recorrendo a RP-HPLC-PDA, concluindo-se que ocorrem poucas variações desses compostos durante a maturação. Por sua vez, no que diz respeito à vitrificação de tecidos, decorrente da sua cultura em meio líquido, investigou-se a parede celular de folhas e caules vitrificados, comparando depois com tecidos não vitrificados. As diferenças nos teores de celulose, polissacarídeos da matriz e lenhina, entre material in vitro não vitrificado e vitrificado, foram reveladas através de técnicas como FTIR., lenhina solúvel em brometo de acetil e quantificação de carbohidratos totais. Contrariamente ao que poderia ser expectável e ao que é normalmente indicado na literatura, os resultados obtidos mostraram, de forma consistente, um teor de lenhina mais elevado nas folhas do que nos caules. Por outro lado, através de microscopia ótica de campo claro, fluorescência e varrimento, revelaram-se informações meticulosas sobre a anatomia de A. unedo, através de comparações entre folhas e caules de um arbusto e de material in vitro, vitrificado e não vitrificado. Em comparação com folhas normais, as vitrificadas evidenciaram uma epiderme desorganizada e fina, com imensos complexos estomáticos anormais presentes na página inferior da folha. O mesófilo apresentava grandes espaços lacunares e não existia um parênquima em paliçada bem definido. No que diz respeito aos caules, as principais diferenças estão relacionadas com as células corticais muito espaçadas devido à presença de pronunciados espaços intercelulares. A presente dissertação contribui para um melhor conhecimento desta espécie economicamente importante, mas pouco conhecida, não só pelo melhor conhecimento do processo de maturação dos frutos, mas também por ajudar a perceber as alterações morfológicas e químicas num fenótipo vitrificado.
The Ericaceae family comprises a wide number of economic relevant species, such as the plants belonging to the Rhododendron and Vaccinium genera. Among them, the Mediterranean evergreen shrub Arbutus unedo L. outstands from the pomological and ornamental point of view. For an in-depth knowledge of this plant, the ripening-derived composition and morphology was monitored, aiming at identifying factors and events related with fruit maturation. Accordingly, to explore the ripening-derived compositional differences, FTIR spectroscopy was performed, founding chemical variations related to the structural polysaccharides of the cell wall, between immature and fully ripen fruits. Further spectroscopic investigations using the fruits intact biomass, revealed more variations, mainly due to matrix polysaccharides like pectins and hemicelluloses, and cellulose. The process of maturation was also found to be related to an increase of total soluble solids content (˚Brix), and a decrease in fruits acidity. Notwithstanding, the hydrolysis and/or oxidative derived-degradation of structural sugars, results in an extreme decline of fruit firmness, leading to fruit softening, and variations in the polar and equatorial diameters. Furthermore, a preliminary phenolic profile of the fruits was also investigated by RP-HPLC-PDA, and only slight variations of the phenolic compounds were observed during fruit maturation. On the other hand, concerning the vitrification (hyperhydricity) phenomenon that outcomes through the culture of axillary shoots in liquid medium, the cell wall of non-vitrified and vitrified in vitro shoots of A. unedo was evaluated, comparing leaves and stems. Regarding on the differences in the amounts of cellulose, matrix polysaccharides and lignin, compositional differences were uncovered in leaves and stems from in vitro shoots, using FTIR spectroscopy, acetyl-bromide soluble lignin method and total carbohydrates estimation. Unexpectedly, our results showed higher amounts of lignin in leaves, comparing to stems. Additionally, meticulous information about the A unedo anatomy was assessed by light, fluorescence and scanning electron microscopy, making comparisons between leaves and stems of non-vitrified and vitrified in vitro shoots, and tissues from a strawberry tree. Comparing with normal leaves, the vitrified ones showed to have a delicate and disorganized epidermis, with many abnormal stomata present in the abaxial surface. The mesophyll has wide lacunar spaces, and lack of palisade parenchyma. Concerning vitrified stems, the major differences relied on the the broad-spaced cortical cells. In the end, the present dissertation contributed to better characterization of this economic relevant species but largely unknown, not only for a better understanding on the fruits ripening events, but also by helping to unveil the chemical and anatomy-related factors of the vitrified phenotype.
Outro - This master thesis was supported by the Project “RENATURE – Valorization of the Natural Endogenous Resources of the Centro Region” (CENTRO-01-0145-FEDER-000007), funded by the Comissão de Coordenação da Região Centro (CCDR-C) and subsidized by the European Regional Developmental Fund (FEDER)
Cleemput, Stijn. "Breeding for a reduced glucosinolate content in the green mass of rapeseed to improve its suitability for biogas production". Doctoral thesis, 2011. http://hdl.handle.net/11858/00-1735-0000-0006-AB34-8.
Botha, Lynette Elizabeth. "Investigating the production of secondary metabolites effective in lowering blood glucose levels in Euclea Undulata Thunb. Var Myrtina (Ebenaceae)". Diss., 2016. http://hdl.handle.net/10500/21927.
Environmental Sciences
M. Sc. (Environmental Science)
Huang, Shiow-chyn, e 黃秀琴. "Chemical and Biological Investigation of Stem Bark of Citrus grandis f. buntan and Stem Bark and Leaves of Clausena excavata". Thesis, 1993. http://ndltd.ncl.edu.tw/handle/73093601490298139354.
Chou, En-tzu, e 周恩慈. "Studies on the chemical constituents and biological activities from the stem and leaves of Beilschmiedia tsangii". Thesis, 2006. http://ndltd.ncl.edu.tw/handle/33044322881364055640.
大仁科技大學
製藥科技研究所
94
Abstract Beilschmiedia tsangii Merr. (Lauraceae)1) is an evergreen tree, distributed in forests at low altitudes throughout southern Taiwan. Andiandric acids7), aporphine alkaloids4), bisbenzylisoquinoline alkaloids6), and arylpropanoids are widely distributed in plants of the genus Beilschmiedia. Some isolates exhibit biological activities, including antibacterial7) and antimalarial6) properties. However, the chemical constituents and biological activities of this plant have never been studied. Approximately 1000 species of Formosan plants have been screened for cytotoxicity, and B. tsangii was shown to be one of the active species. Investigation of CHCl3-soluble fraction of the stem of B. tsangii has led to the isolation of two new tetrahydrofuran-type lignans, beilschmin A (1) and beilschmin B (2), two new dihydrofuran-type lignan, beilschmin C (3) and beilschmin D (4), two new 1-phenylbutyl benzoates, tsangin A (5) and tsangin B (6), together with thirteen known compounds, including a tetrahydrofuran-type lignan, rel-(7S,8S,7’R,8’R)- 3,3’,4,4’,5,5’-hexamethoxylignan (7), seven steroids, β-sitosterol (8), β-sitostenone (9), 6α-hydroxystigmast-4-en-3-one (10), 6β-hydroxystigmast-4-en-3-one (11), 3β-hydroxystigmast-5-en-7-one (12), stigmast-4-en-3,6-dione (13) and ergosta-4,6,8(14),22-tetraen-3-one (14), a sesquiterpenoid, 2,6,11-tri- methyldodeca-2,6,10-triene (15), two benzaldehydes, vanillin (16) and 4-hydroxybenzaldehyde (17), a benzoquinone, α-tocopheryl quinone (18), and α-tocospiro B (19). In addition, investigation on the CHCl3-soluble fraction of the leaves of B. tsangii has led to the isolation of two new tetrahydrofuran-type lignans, beilschmin A (1) and beilschmin B (2), together with seven known compounds, including a tetrahydroxyfuran-type lignan, rel-(7S,8S,7’R,- 8’R)-3,3’,4,4’,5,5’-hexamethoxylignan (7), two steroids, β-sitosterol (8) and β-sitostenone (9), a benzoquinone, α-tocopheryl quinone (18), a triterpenoid, squalene (20), a tocopherone, α-tocopherol trimer B (21) and a aliphatic ester derivative, methyl linoleate (22). The structures of these new compounds were determined through spectral analyses. Among the isolates, compounds 1-3, 5, 6, 15, 18 and 19 exhibited cytotoxicities (IC50 values < 4 μg/mL) against P-388 and/or HT-29 cell lines in vitro. Compounds 1 and 2 also showed significant antitubercular activities in vitro (MIC = 2.5 and 7.5 μg/mL, respectively).
Blakewood, Amanda Marie. "Testing the Fit of a Model of Faculty Departure Intentions for Women Faculty in STEM and Non-STEM Disciplines". 2011. http://trace.tennessee.edu/utk_graddiss/1060.
Huang, Shi-Yu, e 黃士俞. "Studies on the Chemical Constituents and Cytotoxic Activities from the Stem Wood and Leaves of Hibiscus tiliaceus and the Stem Wood of Zanthoxylum integrifoliolum". Thesis, 2006. http://ndltd.ncl.edu.tw/handle/33476255725275823555.
大仁科技大學
製藥科技研究所
94
As a series of studies on the cytotoxic constituents of Formosan plants, many species have been screened for in vitro cytotoxic test. Among them, the MeOH extract of the stem wood and leaves of Hibiscus tiliaceus and the stem wood of Zanthoxylum integrifoliolum exhibited cytotoxic activities. Investigation of an EtOAc-soluble fraction of the stem wood of H. tiliaceus has led to the isolation of thirteen compounds, including hibiscusin (1), hibiscusamide (2), vanillic acid (3), p-hydroxybenzoic acid (4), syringic acid (5), p-hydroxybenzaldehyde (6), scopoletin (7), N- trans-feruloyltyramine (8), N-cis-feruloyltyramine (9), β-sitosterol (10), stigmasterol (11), β-sitostenone (12), and stigmasta-4,22-dien-3-one (13). In addition, seven compounds have been isolated from an EtOAc-soluble fraction of the leaves of Hibiscus tiliaceus, and the isolates included friedelan-3-one (14), epi-friedelinol (15), trans-phytol (16),α-tocopherol (17),α-tocopheryl quinone (18), β-sitosterol (10), and stigmasterol (11). Among them, 1 and 2 are new compounds. Investigation of an EtOAc-soluble fraction of the stem wood of Z. integrifoliolum has led to the isolation of seventeen compounds, including γ-fagarine (19), skimmianine (20), haplopine (21), robustine (22), tetracosyl ferulate (23), vanillin (24), canthin-6-one (25), 4-methoxy-1- methyl-2-quinolone (26), 6,7-dimethoxycoumarin (27), trans-coniferyl aldehyde (28), parthenin (29), evofolin-C (30), p-hydroxybenzaldehyde (6),β-sitosterol (10), stigmasterol (11), β-sitostenone (12), and stigmasta -4,22-dien-3-one (13). The structures of these isolates were determined through spectral analyses. Among them, 2, 8, 9, 18, 19, 20 and 25 showed significant cytotoxicities (IC50 values < 4 μg/mL) against P-388 cell line. In addition, 2, 19 and 21 also show significant cytotoxicities (IC50 values < 4 μg/mL) against HT-29 cell line.
Chen, Po-Hou, e 陳柏豪. "Studies on the Chemical Constituents and Biological Activities from the Stem Wood and Leaves of Zanthoxylum integrifoliolum". Thesis, 2007. http://ndltd.ncl.edu.tw/handle/06816690293777478352.
大仁科技大學
製藥科技研究所
95
Zanthoxylum integrifoliolum (Merr.) Merr (Rutaceae) is an evergreen tree distributed in northern Philippine and on Lanyu Island in Taiwan. In our studies on the anti-inflammatory constituents of Formosan plants, many species have been screened for in vitro anti-inflammatory activity to date and Z. integrifoliolum has been found to be one of the active species. Continuing investigation of an EtOAc-soluble fraction of the stem wood of Zanthoxylum integrifoliolum has led to the isolation of twenty-two compounds, including (R,E)-1-[4-(3-hydroxyprop-1 -enyl)phenoxy]-3-methylbutane-2,3-diol (1), 4-hydroxy-3-(3-methyl-2- butenyl)cinnamyl alcohol (2), 2,6-bis(1-phenylethyl)phenol (3), 2,4-bis(1-phenylethyl)phenol (4), 18-demethylparaensidimerin C (5), 4-[4-(3-hydroxypropenyl)phenoxy]-2-meyhylbut-2-en-1-ol (6), 1-[(3-methylbut-2-enyl)oxyl]-2-methoxy-4-(prop-1-en-3-ol)benzene (7), 1-(2-hydroxyphenyl)-1-(1-phenyl)ethane (8), paraensidimerin C (9), syringaldehyde (10), trans-p-coumaryl aldehyde (11), isoscopoletin (12), 6,7,8-trimethoxycoumarin (13), (-)-sesamin (14), (-)-syringaresinol (15), (-)-simulanol (16), (-)-5-methoxybalanophonin (17), (-)-balanophonin (18), (-)-dehydrodiconiferyl alcohol (19), N-methylflindersine (20), (R)-(+)-platydesmine (21) and decarine (22) . In addition, fifteen compounds have been isolated from an EtOAc-soluble fraction of the leaves of Zanthoxylum integrifoliolum, and the isolates included decarine (22), 1-hydroxyrutaecarpine (23), rutaecar- pine (24), (-)-sesamin (14), (+)-piperitol (25), ergosta-4,6,8(14),22- tetraen-3-one (26), β-sitosterol (27), β-sitostenone (28), stigmasta-4,22- dien-3-one (29), 3��-hydroxystigmast-5-en-7-one (30), methyl 4-hydroxy- benzoate (31), ��-tocopheryl quinone (32), (2E,4E)-N-isobutyl- 2,4-tetradecadienamide (33), squalene (34) and luvangetin (35). The structures of all isolates were determined through spectral analyses and comparison of their physical and spectral data with literature. Among them, 1-5 are new compounds. Compounds 16 and 20 exhibited potent inhibition against fMLP-induced superoxide production with IC50 = 11.83 ± 5.23 and 4.28 ± 0.89 �嵱, respectively. Compound 22 showed marked antitubercular activities (MIC = 12.5 �慊/mL) against Mycobac- terium tuberculosis H37Rv.
Lee, Hsinn-Hsing, e 李信興. "Studies on the Chemical and Cytotoxic Constituents from the Leaves of Muntingia calabura and the Stem Woods of Zanthoxylum pistaciiflorum". Thesis, 2005. http://ndltd.ncl.edu.tw/handle/26272677681905925041.
大仁科技大學
製藥科技研究所
93
As a series of studies on the chemical constitutents and cytotoxic activities of Formosan plants, the leaves of Muntingia calabura (Tiliaceae) and the stem wood of Zanthoxylum pistaciiflorum (Rutaceae) were investigated. Investigation on the leaves of Muntingia calabura has led to the isolation of forty compounds including: tectochrysin (1), 3,7-dimethoxy-5-hydroxyflavone (2), 5-hydroxy-3,6,7-trimethoxyflavone (3), 6,7-dimethoxy-5-hydroxyflavone (4), guaphaliin (5), 8-methoxy-3,5,7-trihydroxyflavone (6), izalpinin (7), 5,7-dihydroxy-3,8-dimethoxyflavone (8), galangin (9), chrysin (10), 5,4''-dihydroxy-3,7-dimethoxyflavone (11), 7-methoxyflavone (12), 5,7-dihydroxy-3-methoxyflavone (13), 5,7-dihydroxy-6-methoxyflavone (14), muntingone (15), (2S)-7-hydroxy-8-methoxyflavanone (16), (2S)-7-hydroxyflavanone (17), (2S)-5''-hydroxy-7,3'',4''-trimethoxyflavanone (18), (2R,3R)-(-)-3,5-dihydroxy-6,7-dimethoxyflavanone (19), (2S)-4''- hydroxy-7-methoxyflavanone (20), (2S)-5''-hydroxy-7,8,3'',4''-tetramethoxyflavan (21), (2S)-7,8,3'',4'',5''-pentamethoxyflavan (22), 2'',4''-dihydroxychalcone (23), larrein (24), 2'',4''-dihydroxy-3''-methoxydihyrochalcone (25), 2'',4''-dihydroxydihydrochalcone (26), (-)-3''-methoxy-2'',4'',β-trihydroxydihydrochalcone (27), 2,3-dihydroxy-4,3'',4'',5''-tetramethoxydihydrochalcone (28), methyl 4-hydroxybenzoate (29), Isovanillic acid (30), p-nitrophenol (31), methyl gallate (32), trans-methyl Ρ-coumarate (33), β-sitostenone (34), β-sitosterol (35), stigmasterol (36), β-amyrenone (37),α-tocopheryl quinone (38), δ-tocopherol (39) and α-tocospiro B (40). Fifteen compounds have been isolated from the stem woods of Zanthoxylum pistaciiflorum. The isolates included trans-methyl p-coumarate (33), β-sitostenone (34), β-sitosterol (35), robustine (41), dictamnine (42), γ-fagarine (43), skimmianine (44), syringaresinol (45), (-)-hinokinin (46), xanthoxylol 3,3-dimethylallyl ether (47), 5,5''-dimethoxy-7-oxolariciresinol (48), wutaiensal (49), glycocitridine (50), 3-(4-hydroxyphenyl)propionic acid methyl ester (51), and 3β-hydroxystigmast-5-en-7-one (52). The structures were elucidated by spectral analyses and comparison of their physical and spectral data with literature. Among them, 15, 18, 19, 25, 27 and 28 are new compounds. Compounds 18, 20, 23, 25 and 38 showed significant cytotoxicities (ED50 values < 4 g/mL) against P-388 cell line. In addition, compounds 23 and 25 also show significant cytotoxicities (ED50 values < 4 g/mL) against HT-29 cell line.
Köcher, Paul. "Hydraulic traits and their relevance for water use strategies in five broad-leaved tree species of a temperate mixed forest". Doctoral thesis, 2012. http://hdl.handle.net/11858/00-1735-0000-0001-BC4A-8.
Morton, Dawn Renee. "The correlation between church leaders' understanding of the issue of child sexual abuse and preventive steps taken within their churches". Thesis, 2005. http://hdl.handle.net/10392/388.
This item is only available to students and faculty of the Southern Baptist Theological Seminary. If you are not associated with SBTS, this dissertation may be purchased from http://disexpress.umi.com/dxweb or downloaded through ProQuest's Dissertation and Theses database if your institution subscribes to that service.
Vinas, Keila L. "Narratives of women's leadership identity development: an assessment of senior-level information technology (IT) leaders following participation in a women-only training program". Thesis, 2017. https://hdl.handle.net/2144/20896.
Bates, Philip David. "Re-examining the initial steps of membrane and storage lipid assembly in pea leaves and soybean embryos the dominant flux of newly synthesized fatty acid incorporation into extra-plastidic glycerolipids is through phosphatidylcholine acyl editing /". Diss., 2008. http://proquest.umi.com/pqdweb?did=1681946151&sid=1&Fmt=2&clientId=3552&RQT=309&VName=PQD.
Title from PDF t.p. (Proquest, viewed on Aug. 17, 2009) Includes bibliographical references (p. 187-203). Also issued in print.
Bean, Lynne. "The morphological revisions of freshwater fish from Late Jurassic - Early Cretaceous sites in Australia and other Gondwanan continents leads to new phylogenetic hypotheses of relationships among stem teleosts". Phd thesis, 2021. http://hdl.handle.net/1885/235247.
Shouqiang, Li. "The moderating role of leader-member exchange as a moderating variable on the relationship between perceived stress and burnout in clincians". Doctoral thesis, 2019. http://hdl.handle.net/10071/21298.
Sob a influência do meio envolvente e interno, os profissionais das saúdes chineses encontram-se sob grande pressão. Tomando por base o modelo das exigências de recursos (JD-R) e a teoria da troca social, este estudo explora o efeito moderador da LMX (Troca Líder-Membro) na gestão do burnout causado pelo stress percebido pelos profissionais das saúdes na China. Com base numa revisão extensa de literatura sobre stress percebido, burnout e LMX, este estudo discute primeiro o impacto do stress percebido e das suas três dimensões entre profissionais das saúdes, e examina os efeitos da LMX no burnout e nas suas três dimensões, e finalmente, estuda o papel mediador da LMX entre o stress percebido e o burnout. Realizou-se um inquérito por questionário junto de três hospitais em Cantão e recolheram-se 434 respostas válidas. Testaram-se as hipóteses por via de análise de dados utilizando o IBM SPSS 19-0 e o AMOS 21.0. As análises de regressão mostraram que o stress percebido exerce um impacto positivo no burnout e nas suas três dimensões; nomeadamente na exaustão emocional, na despersonalização e desempenho reduzido. Em acréscimo, a LMX modera a relação entre o stress percebido e o burnout e as suas três dimensões de tal forma que a relações se tornam mais fracas para os profissionais das saúdes que têm maior LMX. Os resultados deste estudo facultam um entendimento complementar útil para a investigação sobre o stress percebido nas profissionais da saúde e para melhor gerir o burnout profissionais da saúde na China.