• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 696
  • 553
  • 150
  • 55
  • 31
  • 27
  • 24
  • 24
  • 24
  • 24
  • 24
  • 24
  • 18
  • 11
  • 6
  • Tagged with
  • 1677
  • 478
  • 450
  • 407
  • 326
  • 220
  • 151
  • 145
  • 132
  • 122
  • 116
  • 108
  • 105
  • 103
  • 103
  • 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.
381

Surface modification of pulp fibers with amino acids for Zwitterionic bonding /

López-Dellamary, Fernando A., January 1991 (has links)
Thesis (Ph. D.)--University of Washington, 1991. / Vita. Includes bibliographical references (leaves [102]-109).
382

Zahnmarkschädigungen und ihre unfallrechtliche Bedeutung

Lintz, Walter. January 1900 (has links)
Thesis (Ph. D.)--Universität München, 1933?
383

Development, degeneration and regeneration of nerve fibres in the feline inferior alveolar nerve and mandibular incisor pulps light and electron microscopic studies /

Fried, Kaj. January 1982 (has links)
Thesis (doctoral)--Karolinska Institutet, Stockholm, 1982. / Extra t.p. with thesis statement inserted. Includes bibliographical references (p. 20-28).
384

Development, degeneration and regeneration of nerve fibres in the feline inferior alveolar nerve and mandibular incisor pulps light and electron microscopic studies /

Fried, Kaj. January 1982 (has links)
Thesis (doctoral)--Karolinska Institutet, Stockholm, 1982. / Extra t.p. with thesis statement inserted. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (p. 20-28).
385

In-vitro evaluation of dye leakage of an MTA apical barrier after irrigation with 3% soldium hypochlorite, 2% chlorhexidine, MTAD, or 17% EDTA/3% sodium hypochlorite

Taylor, Nicholas Allen. January 2007 (has links)
Thesis (M.S.)--West Virginia University, 2007. / Title from document title page. Document formatted into pages; contains vii, 40 p. : ill. (some col.). Vita. Includes abstract. Includes bibliographical references (p. 30-34).
386

Análise do padrão de expressão de MMP-2, -9 e -8 em tecido humano pulpar normal e inflamado / Analysis of the expression perfile of MMP-2, -9 and -8 in normal and inflamed human pulp tissue

Maria Cecília Ribeiro de Mattos 19 October 2009 (has links)
As metaloproteinases da matriz (MMPs) foram relacionadas a diversas doenças inflamatórias como artrite e também ao câncer. O presente trabalho tem por objetivo estabelecer o papel da MMP-2, MMP-9 e MMP-8 no processo de inflamação pulpar. Foram adotadas as seguintes hipóteses nulas: (1) o padrão de expressão das MMP-2, MMP-9 e MMP-8 não sofre alteração nos diferentes estágios da polpa humana: normal, reversível, transição, irreversível ou necrose; (2) não há diferença de expressão das MMP-2, -9 e MMP-8, considerando-se um mesmo estágio de inflamação tecidual pulpar. Os métodos utilizados foram: (I) Obtenção dos espécimes, que foram divididos em grupos de acordo com critérios adotados de semiologia subjetiva e objetiva. Obtiveram-se os seguintes grupos: GI (Controle) dentes hígidos (n=7); GII (Pulpite Reversível n=4); GIII (Pulpite Transição n=4); GIV (Pulpite Irreversível/Necrose n=8). Logo após exodontia, os dentes obtidos foram cortados ligeiramente abaixo da junção amelodentinária e fixados em formol a 10% por 48h. Foram lavados em água corrente (24h) para então serem processados histologicamente. Foram obtidas secções de 4m, aderidas em lâminas silanizadas e submetidas à imunomarcação (Técnica da Peroxidase), utilizando os anticorpos anti MMP-2, MMP-9 e MMP-8 humanos. A presença de imunomarcação foi realizada através da análise semi-quantitativa por escores, sendo que a quantificação de marcação por corte seguiu o seguinte escore: 0= ausente; 1= leve; 2= moderada; 3= intensa. Realizou-se teste estatístico não paramétrico Kruskal-Wallis, p<0,05. As comparações intergrupos revelaram, para CO: (1)MMP-2 - GI=GII=GIII, GIII=GIV, GI>GIV (p<0,01) e GII>GIV (p<0,05); (2)MMP-9 GI=GII=GIV, GII=GIII e GIII>GI (p<0,01); (3)MMP-8 GI=GII=GIII=GIV. Na região central da polpa, obteve-se: (1)MMP-2 GI=GII=GIII, GIII=GIV, GI>GIV (p<0,001) e GII>GIV (p<0,01); (2)MMP-9 GI=GII=GIII, GIII=GIV, GIV>GI (p<0,001) e GIV>GII (p<0,01); (3)MMP-8 GI=GII, GIII=GIV, GIII>GI (p<0,05), GIV>GI (p<0,01), GIII>GII (p<0,05) e GIV>GII (p<0,05). Quanto às comparações intragrupos, na CO mostraram: (1)GI - MMP-2>MMP9 (p<0,001), MMP-2=MMP-8 e MMP-9=MMP-8; (2)GII MMP-2>MMP-9 (p<0,01); MMP-2=MMP-8 e MMP-9=MMP-8; (3)GIII e GIV MMP-2=MMP-9=MMP-8. Para a região mais central da polpa: (1)GI e GII MMP-2=MMP-9=MMP-8; (2)GIII MMP9>MMP-2 (p<0,05), MMP- 2=MMP-8 e MMP-9=MMP-8; (3)GIV MMP-9>MMP-2 (p<0,01), MMP-2=MMP-8 e MMP-9=MMP-8. Sendo assim, as duas hipóstese nulas foram rejeitadas. Conclui-se ainda que MMP-2, MMP-9 e MMP-8 atuam no processo de inflamação pulpar de maneira distinta na CO e polpa central; MMP-2 é mais expressa em polpa sadia; a maior expressão de MMP-9 relaciona-se à presença de inflamação pulpar; em polpas inflamadas, a expressão de MMP- 8 é maior quando comparadas a polpas normal, embora tal enzima seja também levemente expressada em tecido pulpar normal. / The matrix metalloproteinases (MMPs) have been related to various inflammatory diseases, such as arthritis, as well as to cancer. The aim of the present study was to establish the role of MMP-2, MMP-9 and MMP-8 in the process of dental pulp inflammation. The following null hypotheses were adopted: (1) the pattern of MMP-2, MMP-9 and MMP-8 expression does not undergo alteration in the following different stages of human pulp: normal, reversible, transition, irreversible or necrosis; (2) there is no difference in the expression of MMP-2, -9 and MMP-8, when considering the same stage of pulp tissue inflammation. The methods used were: (I) Obtainment of specimens, which were divided into groups according to the subjective and objective criteria of semiology adopted. The following groups were obtained: GI (Control) healthy teeth (n=7); GII (Reversible Pulpitis n=4); GIII (Transition Pulpitis n=4); GIV (Irreversible Pulpitis/Necrosis n=8). Soon after extraction the teeth obtained were cut slightly below the amelodentinal junction and fixed in 10% formol for 48h. They were washed under running water (24h) and were histologically processed afterwards. Sections of 4m were obtained, adhered to silanized slides, and submitted to immunomarking (Peroxidase Technique), using human anti MMP-2, MMP-9 and MMP- 8 antibodies. The presence of immunomarking was determined through semi-quantitative analysis by scores, and marking by cut was quantified using the following score: 0= absent; 1= slight; 2= moderate; 3= intense. The Kruskal-Wallis non-parametric statistical test was performed, p<0.05. Intergroup comparisons revealed the following: for CO: (1)MMP-2 - GI=GII=GIII, GIII=GIV, GI>GIV (p<0.01) and GII>GIV (p<0.05); (2)MMP-9 GI=GII=GIV, GII=GIII and GIII>GI (p<0,01); (3)MMP-8 GI=GII=GIII=GIV. In the central region of the pulp, the following results were obtained: (1)MMP-2 GI=GII=GIII, GIII=GIV, GI>GIV (p<0.001) and GII>GIV (p<0.01); (2)MMP-9 GI=GII=GIII, GIII=GIV, GIV>GI (p<0.001) and GIV>GII (p<0.01); (3)MMP-8 GI=GII, GIII=GIV, GIII>GI (p<0.05), GIV>GI (p<0.01), GIII>GII (p<0.05) and GIV>GII (p<0.05). With regard to intragroup comparisons, in CO the following were shown: (1)GI - MMP-2>MMP9 (p<0.001), MMP-2=MMP-8 and MMP-9=MMP-8; (2)GII MMP-2>MMP-9 (p<0.01); MMP-2=MMP-8 and MMP-9=MMP-8; (3)GIII and GIV MMP- 2=MMP-9=MMP-8. For the most central region of the pulp: (1)GI and GII MMP-2=MMP- 9=MMP-8; (2)GIII MMP9>MMP-2 (p<0.05), MMP-2=MMP-8 and MMP-9=MMP-8; (3)GIV MMP-9>MMP-2 (p<0.01), MMP-2=MMP-8 and MMP-9=MMP-8. Therefore, the two null hypotheses were rejected. Moreover, it was concluded that MMP-2, MMP-9 and MMP-8 act in the process of pulp inflammation in a distinct manner in CO and central pulp; more MMP-2 is expressed in healthy pulp; the highest expression of MMP-9 is related to the presence of pulp inflammation; in inflamed pulp, the expression of MMP-8 is higher when compared with that of normal pulp, although this enzyme is also slightly expressed in normal pulp tissue.
387

Avaliação de coprodutos da alimentação humana como fonte alternativa de fibras para cães: parâmetros digestivos e metabólicos / Evaluation of co-products human food as an alternative source of fiber for dogs: digestive and metabolic

Livia Rosa Folconi 08 September 2015 (has links)
As fibras de coprodutos da produção de sucos, néctar e refrescos possuem propriedade funcional, envolvidas no metabolismo fermentativo da microbiota intestinal, com benefícios potenciais á saúde dos cães. O emprego de coprodutos alimentícios humano no desenvolvimento de petfood apresentam vantagens de sustentabilidade ambiental e econômica. O estudo objetivou avaliar os efeitos de dietas extrusadas com inclusão fixa de 3,5% de celulose (CEL), farelo de arroz desengordurado (FAR), polpa cítrica (PCT) e polpa de maçã (PMA) como fontes de fibras dietéticas solúveis e insolúveis nos coeficientes de digestibilidade aparente dos nutrientes (CDA), respostas glicêmicas e insulinêmicas pós- prandiais e produtos de fermentação nas fezes. O experimento foi realizado com oito cães adultos hígidos, peso médio de 15,0&#177;5,0kg e idade média de 5,0&#177;2,0 anos, distribuídos em delineamento em dois quadrados latino 4x4. Após 7 dias de adaptação dos animais, realizou-se coleta de fezes nos dias 5&ordm;-10&ordm; para determinar CDA das dietas, entre 12&ordm; ao 15&ordm; dia mensurados pH, produção de ácido lático, AGCC, AGCR e aminas biogênicas (AB) das fezes, seguidos pelas coletas de sangue para determinação das respostas glicêmicas e insulinêmicas pós-prandiais nos 16&ordm; e 17&ordm; dias. Não houve efeito dos tratamentos (p>0,05) no CDA da matéria orgânica (MO) e matéria mineral (MM), entretanto, houve efeito (p<0,05) nos CDAs da proteína bruta (PB), extrato etéreo em hidrólise ácida (EEHA), fibra bruta (FB) e extrativos não nitrogenados (ENN). O tratamento CEL apresentou maior CDA da PB e menor CDA da FB. O CDA dos ENN não apresentou diferença entre PMA e CEL. Em relação às características fecais, observou-se maior MS no tratamento CEL. Os tratamentos PCT e PMA resultaram em pH das fezes inferior aos tratamentos CEL e FAR e sem diferenças entre si. O tratamento PMA resultou em maior escore fecal e menor produção de fezes por cão/dia na MS, contrário ao tratamento PCT, que resultou em maior produção de fezes cão/dia, na MO e MS. Não foi observado efeito dos tratamentos (p>0,05) nas concentrações fecais de lactato e AB. O tratamento PCT resultou em maior produção de acetato, propionato e butirato que o tratamento CEL (p<0,05), enquanto que os tratamentos PCT e PMA resultaram em produção de AGCR mais elevados que FAR (p<0,05). Não houve efeito das fontes de fibras estudadas nas respostas glicêmicas e insulinêmicas pós- prandiais (p<0,05). / The coproducts of fiber production of juice, nectar and soft drinks have functional property, involved in fermentative metabolism of intestinal microbiota, with potential benefits to health of dogs. The use of co-products of human food industry in the development of petfood has advantages of environmental and economic sustainability. The study aimed to evaluate the effects of extruded diets with fixed inclusion of 3.5% cellulose (CEL), defatted rice bran (FAR), citrus pulp (PCT) and apple pulp (PMA) as sources of soluble and insoluble dietary fibers on dog total tract apparent digestibility coefficient of nutrients (ADC), glycemic and insulin postprandial responses, and fermentation products in the stool. The experiment was carried out on eight healthy adult dogs of mean weight of 15.0 &#177; 5,0kg and a mean age of 5,0 &#177; 2,0 years allotted to a 4 x 4 Latin square two. After 7 days of adjustment of the animals to the diets, there was feces collection in the days 5th-10th to determine CDA diets, between 12th to 15th measured pH, lactic acid production, AGCC, AGCR and biogenic amines (BA) of the stool, followed by blood samples for determination of glucose and insulin responses postprandial in 16 and 17 days. There was no effect of the treatments (p> 0.05) in the ADC of organic matter (OM) and mineral matter (MM), however, was no effect (p <0.05) in CDAs of dry matter (DM), crude protein (CP), ether extract acid hydrolysis (EEHA), crude fiber (CF) and nitrogen free extract (NFE). The CEL treatment obtained higher ADC of CP and lower ADC of FB. The ACD of NFE no difference between PMA and CEL. For fecal characteristics, there was a higher DM in CEL treatment. PCT treatments and PMA resulted in fecal pH lower than the CEL and FAR treatments and without differences. The PMA treatment resulted in greater fecal score and lower production of faeces per dog / day in DM, contrary to the PCT treatment, which resulted in increased production of dog feces / day in MO and DM. There was no effect of the treatments (p> 0.05) in fecal concentrations of lactate and AB. The PCT treatment resulted in increased production of acetate, propionate and butyrate that CEL treatment (p <0.05), while the PCT and PMA treatments resulted in higher production AGCR that FAR (p <0.05). There was no effect (p <0.05) of sources of fiber studied for glycemic and insulin curves, area under the curve (AUC) of glucose and insulin, increasing blood glucose and insulin.
388

Matrix metalloproteinases (MMPs) and their specific tissue inhibitors (TIMPs) in mature human odontoblasts and pulp tissue:the regulation of expressions of fibrillar collagens, MMPs and TIMPs by growth factors, transforming growth factor-β1 (TGF-β1) and bone morphogenetic protein-2 (BMP-2)

Palosaari, H. (Heidi) 15 August 2003 (has links)
Abstract Dentin formation in physiological and pathological conditions has been widely studied, but the events and regulation are still not completely understood. Odontoblasts, terminally differentiated post-mitotic cells located in a single cell layer around pulp tissue, synthesize and mineralize dentin organic matrix. Growth factors, such as TGF-β1 and BMP-2, have been implicated in the regulation of the responses of odontoblasts and pulp tissue to external irritation. Matrix metalloproteinases (MMPs), a family of 28 endopeptidases collectively capable of degrading virtually all extracellular matrix components, and their specific tissue inhibitors (TIMPs) participate in the organo- and morphogenesis, physiological tissue turnover and pathological tissue destruction in many tissues, but very little is known about their presence, function, and regulation in the dentin-pulp complex cells and tissues. The aim of the work presented in this thesis was to analyze the expression and regulation of collagens, MMPs and TIMPs by TGF-β1 and BMP-2 in mature human odontoblasts and pulp tissue. Odontoblasts synthesize and secrete type I and type III collagens, with no clear effect of TGF-β1 on their expression levels. MMP-1, -2, -8, -9, -10, -11, -14, -15, -16, -19 and TIMP-1, -2, -3 and -4 were expressed by both odontoblasts and pulp tissue. MMP-3 and MMP-12 were not expressed in native odontoblasts or pulp tissue, and MMP-7, -24, and -25 were expressed only in odontoblasts. MMP-2, -10, -14, -20 and -23 were expressed more abundantly in odontoblasts, whereas pulp tissue expressed more MMP-13 and MMP-17. Growth factors differentially regulated the expression of different MMPs and TIMPs within and among the cells and tissues studied. In odontoblasts, MMP-1, -8 and -14 were down-regulated, but MMP-7, MMP-9, TIMP-1 and TIMP-3 up-regulated, by either TGF-β1 or BMP-2, alone or in combination. In pulp tissue, growth factors up-regulated the expression of MMP-1, -2, -10, -13, -17 and TIMP-3, but down-regulated TIMP-4. The widespread of expression of MMPs and TIMPs by mature human odontoblasts and pulp tissue suggests that they may participate in dentin matrix organization prior to mineralization, and that growth factors may further control dentin matrix modeling, not by regulating the synthesis of type I or III collagens as previously believed, but rather by differentially regulating each MMPs and TIMPs.
389

Mise au point d’un modèle tridimensionnel de culture d’odontoblastes. Application à l’évaluation in vitro de biomatériaux. / Development of a three-dimensional model of odontoblast culture. Application to an in vitro evaluation of biomaterials

Pérard, Matthieu 15 January 2015 (has links)
L’objectif de ce travail était de mettre au point un modèle de culture cellulaire, afin d’étudier in vitro l’incidence sur la physiologie des cellules pulpaires et en particulier de l’odontoblaste, de biomatériaux utilisés pour traiter les effractions de pulpes dentaires. Ce modèle repose sur l’utilisation de culture sphéroïdes dont la conformation spatiale reproduit plus fidèlement l’environnement in vivo que les cultures bidimensionnelles. Après avoir élaboré le modèle sphéroïde à partir de lignées murines, des expérimentations visant à déterminer la cytotoxicité des matériaux ont été effectuées. Leurs capacités à induire la biominéralisation ont également été évaluées. La dernière partie de ce travail avait pour objectif d’immortaliser des primocultures de cellules pulpaires humaines en transfectant les gènes SV40 et hTERT, afin d’établir une lignée cellulaire / The aim of this study was to develop a cell culture model to assess in vitro the effects on the physiology of pulp cells, in particular the odontoblasts, of biomaterials used to treat dental pulp exposures. This model is based on the use of spheroid culture whose spatial configuration reproduces the in vivo environment more faithfully than do two-dimensional cultures. After developing the spheroid model from mouse lines, experiments to determine the cytotoxicity of the materials were conducted. Their ability to induce bio-mineralisation was also assessed. The last part of this work aimed to immortalise primo-cultures of human pulp cells by transfecting hTERT and SV40 genes, in order to establish a new cell line
390

Einfluss verschiedener Bleichfolgen auf die Hemicellulosenzusammensetzung und -verteilung über den Querschnitt der Faserwand

Freese, Maren 13 April 2010 (has links)
Die Festigkeitseigenschaften des Papiers hängen vom Gehalt und der Verteilung der Hemicellulosen über den Querschnitt der Faserwand ab. Hemicellulosen werden durch verschiedene Bleichverfahren unterschiedlich stark angegriffen und herausgelöst. Durch Untersuchungen an einem Fichtensulfitzellstoff ist es gelungen, die Auswirkungen einzelner Bleichstufen [Peroxidverstärkte Sauerstoffstufe (EOP), Ozonstufe (Z) und Peressigsäurestufe (PAA)] und Bleichsequenzen (EOP-Z-P, EOP-PAA-P) auf Faseroberfläche, Hemicellulosenzusammensetzung und -verteilung sowie auf die optischen und mechanischen Eigenschaften des daraus gebildeten Papiers aufzuzeigen. Um die Verteilung der Hemicellulosen über den Querschnitt der Faser zu beschreiben, wird das Verfahren des chemischen Abschälens verwendet und schrittweise die Faserwand entfernt. Der gebleichte bzw. abgeschälte Zellstoff wird rasterelektronenmikroskopisch untersucht, hydrolysiert und anschließend die Hemicellulosenzusammensetzung quantitativ mittels Hochdruckflüssigkeitschromatographie (HPLC) unter Nutzung eines Flüssigkeitsmassenspektrometers (LCMS) als Detektor bestimmt. Zusätzlich erfolgt die Bestimmung der Papiereigenschaften. Diese Untersuchungen bestätigen, dass die verschiedenen Hemicellulosengehalte nach den Bleichstufen Unterschiede bei den Festigkeitseigenschaften bewirken. Die Untersuchungen zeigen den positiven Effekt der Peressigsäurestufe für die Papierherstellung im direkten Vergleich zur Ozonstufe. Zusätzlich wurde auch der Einfluss des Aufschlusses geprüft. Hierzu wurden die endgebleichten Sulfitzellstoffe mit einem endgebleichten Sulfatzellstoff verglichen. / The mechanical strength of paper pulp depends strongly on the hemicellulose content and the hemicellulose distribution across the cell wall layers. Hemicelluloses get differently attacked and dissolved by different bleaching methods. The investigations with a paper grade sulphite pulp show the influence of the separate bleaching steps [hydrogen peroxide reinforced oxygen stage (EOP), ozone (Z) und peracetic acid (PAA)] and bleaching sequences (EOP-Z-P, EOP-PAA-P) of the fibre surface, hemicellulose content and distribution as well as the optical and mechanical characteristics of paper. To describe the hemicellulose distribution across the cell wall layers a procedure of a precise chemical peeling was used in order to remove stepwise the cell wall. The bleached and peeled pulp was investigated by scanning electronic microscope (SEM) to get more information about the penetration of the bleaching chemicals into the fibre surface. The hemicelluloses were determined by high performance liquid chromatography (HPLC) using a liquid chromatography mass spectrometer (LCMS) after hydrolysing polysaccharides to monosaccharides. In addition to this paper properties were analysed. This research confirms the effect of different hemicellulose compositions of the mechanical strength. The analyses represent the positive effect for paper production of the peracetic acid step in contrast to the ozone step. Additional the influence of the pulping process was determined by a sulphate pulp comparing with the sulphite pulp.

Page generated in 0.0428 seconds