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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.
21

Uso de paclobutrazol na produção de mudas, no crescimento, produção e qualidade de frutos de tomateiro em ambiente protegido

Seleguini, Alexsander [UNESP] 05 November 2007 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:35:17Z (GMT). No. of bitstreams: 0 Previous issue date: 2007-11-05Bitstream added on 2014-06-13T19:24:51Z : No. of bitstreams: 1 seleguini_a_dr_ilha.pdf: 1010511 bytes, checksum: eb32bdc0873ccf57c670095c19e87ff7 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O objetivo do presente trabalho foi avaliar os efeitos de três concentrações (0, 50 e 100 mg L-1) e dois métodos de aplicação (embebição de sementes e rega de plântulas) de paclobutrazol (PBZ) na produção de mudas, no desenvolvimento e produção de plantas, bem como na qualidade físico-química e vida de prateleira de frutos de tomateiro, híbrido longa vida AF 7631. O trabalho foi conduzido na Universidade Estadual Paulista (UNESP), campus de Ilha Solteira, Estado de São Paulo, Brasil, de setembro de 2006 a março de 2007. As embebições de sementes com 50 e 100 mg L-1 de PBZ inibiram e atrasaram a emergência de plântulas, mas foram ineficientes na redução da altura das plântulas. Entretanto, a aplicação do regulador, via rega, nas mesmas concentrações, aos 15 dias após a semeadura, controlou o desenvolvimento da parte aérea, como demonstrado pelos menores valores médios de altura, área foliar e massa de matéria seca de parte aérea das plântulas, determinando, ainda, o aumento do diâmetro da haste e do desenvolvimento do sistema radicular das plântulas. Após o transplantio das mudas em ambiente protegido, observou-se que os métodos de aplicação e o incremento das concentrações de PBZ não influenciaram significativamente a produtividade. O tratamento das mudas via rega, com concentrações crescentes de PBZ, reduziu linearmente a altura das plantas, a taxa de crescimento absoluto, a altura de inserção da primeira inflorescência e a massa de matéria seca de folhas e hastes. Independentemente do método de aplicação de PBZ, o aumento das concentrações reduziu significativamente o vigor das brotações laterais e aumentou a produção de frutos pequenos. Ainda, as regas das mudas com 50 e 100 mg L-1 de PBZ, aos 15 dias após a semeadura, não alteraram a vida de prateleira dos frutos, porém, com o aumento... / The aim of the present work was to evaluate the effects of three solution concentrations (0, 50, 100 mg L-1) and two methods of application (seed imbibition and drench of seedlings) of paclobutrazol (PBZ), on seedlings production, plant development and yield, as well as physico-chemical quality and shelf-life of tomato fruits, hybrid AF 7631. The experiment was conducted out at São Paulo State University, UNESP, campus of Ilha Solteira, São Paulo State, Brazil, from September of 2006 to March of 2007. It was found that the seeds imbibitions with PBZ, at 50 and 100 mg L-1, inhibited or delayed the seedlings emergence, as well as it was ineffective in reducing the height of the seedlings. However, the use of growth regulator drenches, in the same concentrations, at the 15th day after the sowing, was effective in controlling the plant development, as showed by the lowest means of seedlings height, leaf area and dry mass, and it still contributed to the increase in the stem diameter, measured at the base of the hypocotyls, and in the development of seedlings roots of tomatoes. After the seedlings transplant to the greenhouse, it was observed that the methods of application, as well as plant growth regulator concentration, did not affected significantly the yield. The seedling drenches, with increasing PBZ concentrations, induced linear decrease in the plant height, in the absolute growth rate, in the height of the first inflorescence and in the dry matter mass of leaves, shoots and stem. It was also observed that, independently of the method of application, the increase in PBZ solution concentrations significantly reduced the side shoots vigour and increased the yield of fruits classifield as small size. Further more, the drenches of PBZ on tomato seedlings, in concentrations of 50 and 100 mg L-1, did not ...(Complete abstract click electronic access below)
22

Uso de paclobutrazol na produção de mudas, no crescimento, produção e qualidade de frutos de tomateiro em ambiente protegido /

Seleguini, Alexsander. January 2007 (has links)
Orientador: Max José de Araújo Faria Júnior / Banca: Shizuo Seno / Banca: Jacira dos Santos Isepon / Banca: Arlete Marchi Tavares de Melo / Banca: Marie Yamamoto Reghim / Resumo: O objetivo do presente trabalho foi avaliar os efeitos de três concentrações (0, 50 e 100 mg L-1) e dois métodos de aplicação (embebição de sementes e rega de plântulas) de paclobutrazol (PBZ) na produção de mudas, no desenvolvimento e produção de plantas, bem como na qualidade físico-química e vida de prateleira de frutos de tomateiro, híbrido longa vida AF 7631. O trabalho foi conduzido na Universidade Estadual Paulista (UNESP), campus de Ilha Solteira, Estado de São Paulo, Brasil, de setembro de 2006 a março de 2007. As embebições de sementes com 50 e 100 mg L-1 de PBZ inibiram e atrasaram a emergência de plântulas, mas foram ineficientes na redução da altura das plântulas. Entretanto, a aplicação do regulador, via rega, nas mesmas concentrações, aos 15 dias após a semeadura, controlou o desenvolvimento da parte aérea, como demonstrado pelos menores valores médios de altura, área foliar e massa de matéria seca de parte aérea das plântulas, determinando, ainda, o aumento do diâmetro da haste e do desenvolvimento do sistema radicular das plântulas. Após o transplantio das mudas em ambiente protegido, observou-se que os métodos de aplicação e o incremento das concentrações de PBZ não influenciaram significativamente a produtividade. O tratamento das mudas via rega, com concentrações crescentes de PBZ, reduziu linearmente a altura das plantas, a taxa de crescimento absoluto, a altura de inserção da primeira inflorescência e a massa de matéria seca de folhas e hastes. Independentemente do método de aplicação de PBZ, o aumento das concentrações reduziu significativamente o vigor das brotações laterais e aumentou a produção de frutos pequenos. Ainda, as regas das mudas com 50 e 100 mg L-1 de PBZ, aos 15 dias após a semeadura, não alteraram a vida de prateleira dos frutos, porém, com o aumento...(Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The aim of the present work was to evaluate the effects of three solution concentrations (0, 50, 100 mg L-1) and two methods of application (seed imbibition and drench of seedlings) of paclobutrazol (PBZ), on seedlings production, plant development and yield, as well as physico-chemical quality and shelf-life of tomato fruits, hybrid AF 7631. The experiment was conducted out at São Paulo State University, UNESP, campus of Ilha Solteira, São Paulo State, Brazil, from September of 2006 to March of 2007. It was found that the seeds imbibitions with PBZ, at 50 and 100 mg L-1, inhibited or delayed the seedlings emergence, as well as it was ineffective in reducing the height of the seedlings. However, the use of growth regulator drenches, in the same concentrations, at the 15th day after the sowing, was effective in controlling the plant development, as showed by the lowest means of seedlings height, leaf area and dry mass, and it still contributed to the increase in the stem diameter, measured at the base of the hypocotyls, and in the development of seedlings roots of tomatoes. After the seedlings transplant to the greenhouse, it was observed that the methods of application, as well as plant growth regulator concentration, did not affected significantly the yield. The seedling drenches, with increasing PBZ concentrations, induced linear decrease in the plant height, in the absolute growth rate, in the height of the first inflorescence and in the dry matter mass of leaves, shoots and stem. It was also observed that, independently of the method of application, the increase in PBZ solution concentrations significantly reduced the side shoots vigour and increased the yield of fruits classifield as small size. Further more, the drenches of PBZ on tomato seedlings, in concentrations of 50 and 100 mg L-1, did not ...(Complete abstract click electronic access below) / Doutor
23

Controlled molecular beam deposition of hybrid inorganic/organic semiconductor structures

Sparenberg, Mino 21 June 2018 (has links)
Zentrales Thema dieser Dissertation ist die Untersuchung anorganisch/organischer Hybridsysteme (HIOS) mit besonderem Fokus auf den speziellen Prozessen an der Grenzfläche beider Materialklassen. Organische Moleküle, in Verbindung mit anorganischen Halbleitern haben ein großes Potenzial für Anwendungen in zukünftigen optoelektronischen Hybridbauteilen, indem sie Vorteile zweier unterschiedlicher Welten kombinieren. Entscheidend für die Herstellung von hybriden Strukturen ist das Verständnis der Wechselwirkungen an der Grenzfläche zwischen organischem und anorganischem Material. In dieser Arbeit werden diese Wechselwirkungen analysiert, um eine Wachstumskontrolle an der Grenzfläche zwischen konjugierten organischen Molekül und anorganischem Halbleiter zu ermöglichen. Hierfür werden unterschiedliche Ansätze verfolgt: Im ersten Teil der Arbeit wird die Wechselwirkung des Modellsystems Sexiphenyl (6P) an der Grenzfläche zu ZnO untersucht, sowie das Wachstum des Moleküls mittels verschiedener Methoden kontrolliert. Das daraus gewonnene Wissen kann im zweiten Teil dazu verwendet werden einen hybriden ZnO/6P/ZnO-Stapel zu realisieren, bei dem die organische Schicht ohne Beeinträchtigung der Kristallstruktur, mit definierten Grenzflächen bis hin zur atomaren/molekularen Ebene, überwachsen werden kann. Der letzte Teil der Arbeit befasst sich mit der optischen Echtzeit-Beobachtung während des organischen Wachstums verschiedener Moleküle. Dadurch ist es möglich Veränderungen von Struktureigenschaften und Wechselwirkungen zwischen Molekülen und dem Substrat zerstörungsfrei zu bestimmen, während diese aufgewachsen werden. Hierdurch können schlussendlich mögliche Mechanismen aufgezeigt werden, um elektronische und optische Wechselwirkung an der Grenzfläche zwischen organischem Molekül und anorganischen Halbleitern zu analysieren, sowie Wachstumsprozesse weiter zu verstehen und kontrollieren. / The central subject of this thesis are hybrid inorganic/organic systems (HIOS) with a focus on the specific processes at the interface between the two material classes. Organic molecules used together with inorganic semiconductors, have a great potential for future optoelectronic applications in hybrid components, by combining the advantages of two dissimilar worlds. Decisive for the production of hybrid structures is the understanding of the interactions at the interface between organic and inorganic material. In this thesis, the interactions are analyzed to enable growth control at the interface between conjugated organic molecules and inorganic semiconductors. In the first part of the thesis, the interaction of the model system sexiphenyl (6P) at the interface with ZnO, as well as approaches to control the growth of the molecule are being investigated. The knowledge gained here is used in the second part to realize a hybrid ZnO/6P/ ZnO stack, in which the organic layer can be overgrown without affecting the crystal structure, exhibiting defined interfaces down to the atomic/molecular level. The last part of the thesis deals with real time optical observation during organic growth of different molecules. By this changes in structural properties and interactions between molecules and the substrate can be non-destructively determined as they are growing. Ultimately, a comprehensive insight into the optical and electronic interactions at the interface between organic molecules and inorganic semiconductors can be gained and possible control mechanisms are shown.
24

Androgen controlled regulatory systems in prostate cancer : potential new therapeutic targets and prognostic markers

Hammarsten, Peter January 2008 (has links)
BACKGROUND: Prostate cancer is by far the most common cancer among Swedish men. Some patients have an aggressive lethal disease, but the majority of affected men have long expected survival. Unfortunately, the diagnostic tools available are insufficient in predicting disease aggressiveness. Novel prognostic markers are therefore urgently needed. Furthermore, metastatic prostate cancer is generally treated with castration, but the long-term effects are insufficient. Additional studies are therefore needed to explore how the effects of this therapy can be enhanced. Prostate growth and regression is beside testosterone controlled by locally produced regulators. Vascular endothelial growth factor (VEGF) and epidermal growth factor receptor (EGFR) are two of the major regulators in the normal prostate and in prostate tumours. MATERIALS AND METHODS: VEGF and EGFR were explored in the prostate, by treating rats with either anti-VEGF or anti-EGFR treatment during castration and testosterone-stimulated prostate growth. Rats with implanted androgen-independent prostate tumours were treated with an inhibitor of both VEGF receptor-2 (VEGFR-2) and EGFR. Stereological techniques, immunohistochemistry, western blotting and quantitative real-time PCR were used to evaluate these experiments. Furthermore, prostate tissue from untreated prostate cancer patients was used to retrospectively explore the expression of phosphorylated-EGFR (pEGFR) in relation to outcome. RESULTS: Anti-VEGF treatment during testosterone-stimulated prostate growth, inhibited vascular and prostate growth. Anti-EGFR treatment during castration and testosterone-stimulated prostate growth resulted in enhanced castration effects and inhibited prostate growth. Anti-vascular treatment of androgen-independent prostate cancer with an inhibitor of VEGFR-2 and EGFR, that targets the normal and tumour vasculature, enhanced the effects of castration. Low immunoreactivity for pEGFR in prostate epithelial cells, both in the tumour and also in the surrounding non-malignant tissue, was associated with good prognosis. CONCLUSIONS: Anti-vascular treatment, with an inhibitor of VEGFR-2 and EGFR, in combination with castration could be an effective way to treat androgen-insensitive prostate tumours. VEGF and EGFR signalling are necessary components in testosterone-stimulated prostate growth. Phosphorylation of EGFR could be a useful prognostic marker for prostate cancer patients. Tumours may affect the surrounding non-malignant tissue and pEGFR immunoreactivity in the morphologically normal prostate tissue can be used to retrieve prognostic information.
25

Self-organized Growth in Developing Epithelia

Mumcu, Peer 19 October 2011 (has links)
The development of a multicellular organism, such as a human or an animal, begins with the fertilization of an egg cell. Thereupon the organism grows by repeated cell divisions until the adult size is reached and growth stops. Although it is known that intrinsic mechanisms determine the final size of developing organs and organisms, the basic principles of growth control are still poorly understood. However, there is strong evidence that certain morphogens, which are a special class of signaling molecules, act as growth factors and play a key role in growth control. In this work, growth control is studied from a mainly theoretical viewpoint. A discrete vertex model describing the organization of cells by a network of polygons is used, including a description of the cell cycle and a description of dynamical morphogen distributions. Self-organized growth is studied by introducing growth rules that govern cell divisions based on the local morphogen level. This discrete description is complemented by a continuum theory to gain further insight into the dynamics of self-organized growth processes. The theoretical description is applied to the developing wing of the fruit fly Drosophila melanogaster. In the developing wing, which is an epithelium consisting of single-layered cell sheets, the morphogen Decapentaplegic (Dpp) acts as a key growth factor. Experimental data shows that the Dpp distribution is dynamic and adapts to the size of the developing wing. Two mechanisms that rely on a regulatory molecule species and lead to such a dynamic behaviour of the Dpp distribution are studied. Several growth rules are tested and the resulting growth behaviour is quantitatively compared to experimental data of the developing wing. A particular growth rule, that triggers a cell division when the local morphogen level has increased by a certain relative amount, is found to be consistent with experimental observations under normal and several perturbed conditions. It is shown that mechanical stresses that arise due to spatial growth inhomogeneities can have a stabilizing effect on the growth process.
26

On the role of external stimuli to tailor growth of organic thin films

Pithan, Linus 13 April 2017 (has links)
In dieser Arbeit werden neue Strategien zur Wachstumskontrolle funktionaler organischer Dünnschichtmaterialien aufgezeigt, mit denen sich die Eigenschaften molekularer Schichtsysteme gezielt beeinflussen lassen. Ein Fokus liegt dabei auf der Untersuchung des Einflusses von optischen Feldern auf das Wachstumsverhalten. Ein weiterer Schwerpunkt wird auf das Grundlagenverständnis von thermisch aktivierten, kinetischen Prozessen, die die Morphologie während und nach dem Schichtwachstum beeinflussen, gelegt. Zuerst wird am Beispiel des molekularen Halbleiters Sexithiophen (6T) gezeigt, wie sich Kontrolle über das Kristallphasengleichgewicht während des Wachstums auf Kaliumchlorid (KCl) erzielen lässt. Im zweiten Teil der Arbeit wird eine neue Herangehensweise zur direkten Ausrichtung von Molekülkristallen im optischen Feld während ihrer Entstehung studiert. Am Beispiel von Tetracene wird gezeigt wie sich so optische anisotrope Absorptionseigenschaften von Molekülen dazu nutzen lassen den Brechungsindex eines polykristallinen Films lokal durch ein photolitographisches Verfahren zu beeinflussen. Im dritten Teil wird der Einfluss von dynamisch variierenden Wachstumsbedingungen während des Schichtwachstums von PTCDI-C8 studiert. Es wird gezeigt, dass sich die Oberflächenrauigkeit stark reduzieren lässt, indem zu Beginn des Wachstums jeder individuellen molekularen Monolage die Nukleationsdichte stark erhöht und in den darauf folgenden Wachstumsphasen die Diffusivität gezielt gesteigert wird. Im vierten Teil wird das Diffusionsverhalten von n-Alkan Schichten unter thermischen Einflüssen betrachtet. Es wird gezeigt, dass die inhärente molekulare Anisotropie von C44H90 Molekülen (TTC) sowie die sehr geringe, stark anisotrope, Oberflächenenergie dieses Materials ein ungewöhnliches Diffusionsverhalten auslöst. / The research performed in the framework of this thesis focuses on new strategies to effectively control the growth of crystalline thin films of functional organic molecules and attributes the quest for additional growth control parameters in organic molecular beam deposition (OMBD). First the influence of light on the growth process of the sexithiophene (6T) is studied. We find that 6T thin films deposited as conventional in dark environments on KCl exhibit a bimodal growth with phase coexistence of two crystal polymorphs. In contrast, films grown under illumination with 532 nm light show increased phase purity. Further, we establish light-directed molecular self-assembly (LDSA) to generate permanently aligned thin films of tetracene (C18H12) and demonstrate direct patterning with light. Polarized light illumination leads to azimuthally photoaligned films on isotropic, amorphous substrates. Thus, LDSA can be regarded as a new degree of freedom in the quest for control-parameters in organic thin film growth. Next the impact of dynamic temperature oscillations on the time scales of molecular monolayer growth during organic molecular beam deposition is discussed. We strongly increase the island density during nucleation and selectively increase interlayer diffusion at later stages of monolayer growth. We analyse the interplay between molecular interlayer transport and island sizes to understand kinetic processes during growth. In a fourth experiment we show how thermal annealing can be used to improve smoothness and to increase the lateral size of crystalline islands of n-alkane (TTC, C44H90) films. We employ real-time optical phase contrast microscopy to track the diffusion across monomolecular step edges which causes the unusual smoothing during annealing. We rationalise the smoothing behaviour with the highly anisotropic attachment energies and low surface energies of TTC.

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