Thesis--Karolinska Institute. / Errata slip inserted. Includes bibliographies.

Thesis (Ph. D.)--University of Texas at Austin, 2005. / Supervisors: Steven L. Bryant and James W. Jennings Jr. Vita. Includes bibliographical references.

Thesis (Ph. D.)--Oregon Graduate Center, 1987.

Thesis (Ph. D.)--University of Chicago, 1916. / "A Private edition distributed by the University of Chicago libraries." "Reprinted from the Botanical gazette, vol. LXIII, no. 5, May 1917." "Literature cited": p. 395-397. Also issued online.

No description available.

Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico / O exercÃcio prolongado e exaustivo induz uma disfunÃÃo da barreira intestinal. VÃrios estudos mostram que a suplementaÃÃo com alanil-glutamina (A/G) melhora a proliferaÃÃo das cÃlulas intestinais e absorÃÃo de eletrÃlitos. O objetivo deste trabalho foi investigar o efeito da suplementaÃÃo com A/G na permeabilidade intestinal em ratos treinados apÃs um exercÃcio prolongado e exaustivo de nataÃÃo. Utilizamos ratos Wistar, divididos em sete grupos: 1) SedentÃrio (S); 2) SedentÃrio A/G (S-A/G); 3) Treinado (T); 4) Treinado A/G (T-A/G); 5) ExaustÃo (E); 6) ExaustÃo A/G (E-A/G) e 7) Recuperado (R). Os animais dos grupos suplementados receberam o dipeptÃdeo A/G. Os animais foram treinados durante 12 semanas de nataÃÃo. Na metodologia realizamos anÃlises bioquÃmicas de pH, pCO2, pO2, SO2, excesso de bases (BE), pelo mÃtodo de gasometria e lactato e glicose. Analisamos a transcriÃÃo das junÃÃes firmes: ZO-1, Ocludina, Claudina-2 e PEPT-1 atravÃs de RT-PCR. A anÃlise da permeabilidade intestinal foi realizada pelo mÃtodo da ingestÃo de Lactulose/Manitol (L/M). Fizemos tambÃm anÃlise histolÃgica do duodeno, jejuno e Ãleo. O presente estudo foi aprovado pela CEPA-UFC, em protocolo de N 13/13. Nossos resultados mostraram que pCO2 e SO2 foram aumentados nos grupos E e E-A/G, mas houve queda nos parÃmetros de pH e BE para estes mesmos grupos. Encontramos queda dos Ãndices de glicose e aumento das concentraÃÃes de lactato. Houve aumento significativo no percentual de excreÃÃo de lactulose nos grupos E e E-A/G em relaÃÃo ao grupo S. Houve, no entanto, queda da excreÃÃo de lactulose com diferenÃa estatÃstica entre os grupos E e E-A/G, mostrando proteÃÃo da A/G frente ao aumento da permeabilidade intestinal promovida pelo exercÃcio exaustivo. O percentual de excreÃÃo do manitol foi aumentado nos grupos E e E-A/G em relaÃÃo ao grupo S. Entretanto, na anÃlise da relaÃÃo da permeabilidade dos dois carboidratos L/M observamos um aumento significativo no grupo E em relaÃÃo ao grupo S. Contudo, houve diferenÃa significativa entre os grupos E e E-A/G mostrando que a A/G conseguiu reverter os efeitos da atividade exaustiva na permeabilidade intestinal. Observamos aumento da ZO-1 e ocludina nos grupos S-A/G e T em relaÃÃo a S. Houve tambÃm aumento de ZO-1 no grupo E em relaÃÃo ao S. PorÃm, a A/G reverteu à transcriÃÃo destas junÃÃes firmes nos grupos T-A/G e E-A/G. A transcriÃÃo de claudina-2 foi reduzida no grupo S-A/G, mas obtivemos um aumento no grupo E em relaÃÃo ao S e uma diminuiÃÃo de E-A/G em relaÃÃo ao E. Em relaÃÃo ao PEPT-1, observamos aumento da transcriÃÃo nos grupos T e E em relaÃÃo ao S. Contudo, a A/G reverteu à transcriÃÃo deste peptÃdeo no grupo E-A/G em relaÃÃo ao E. Numa anÃlise de 72 horas apÃs o teste de exaustÃo encontramos valores para a permeabilidade intestinal similares aos grupos sedentÃrios. ConcluÃmos que o exercÃcio prolongado e exaustivo alterou a permeabilidade intestinal e a suplementaÃÃo crÃnica com alanil-glutamina teve efeito protetor contra este aumento. O possÃvel mecanismo da A/G no processo estudado refere-se a processos mecÃnicos de interaÃÃo cÃlula-cÃlula (ZO-1 e ocludina) e/ou eletrolÃticos (claudina-2). / The prolonged and exhaustive exercise induces intestinal barrier dysfunction. Several studies show that supplementation with alanyl-glutamine (A/G) improves the cell proliferation intestinal and electrolyte absorption. The aim of our study was to investigate the effect of supplementation with A/G in the intestinal permeability in rats trained after prolonged exercise and exhaustive swimming. We used Wistar rats that were divided into seven groups: 1) Sedentary (S); 2) Sedentary A/G (S-A/G); 3) Trained (T); 4) Trained A/G (T-A/G); 5) Exhaustion (E); 6) Exhaustion A/G (E-A/G); 7) Recovered (R). The animal supplemented groups received the dipeptide A/G. The animals were trained for twelve weeks. In the methodology we performed biochemical analysis of pH, pCO2, pO2, SO2, and bases excess (BE), by the method of gas analysis and lactate and glucose. We analyzed the transcription of tight junctions: ZO-1, Occludin, Claudin-2 and PEPT-1 by RT-PCR. The analysis of intestinal permeability was performed by the method of the ingestion of lactulose/mannitol (L/M). We also performed histological analysis of the duodenum, jejunum and ileum. This study was approved by the CEPA-UFC on Protocol N 13/2013. Our results showed that SO2 and pCO2 were higher in groups E and E-A/G, but decreased the parameters pH and BE for these same groups. We found falling glucose levels and increased concentrations of lactate. A significant increase in the percentage of excretion of lactulose in groups E and E-A/G than in group S. There was, however, fall of excretion of lactulose with statistical difference between groups E and E-A/G, showing protection against the alanyl-glutamine increased intestinal permeability promoted by exhaustive exercise. The percentage of excretion of mannitol was increased in groups E and E-A/G than in group S. However, in the analysis of the excretion of both carbohydrates lactulose/mannitol we observed a significant increase in group E than in group S. However, there was significant difference between groups E and E-A/G showing that Ala/Gln was able to reverse the effects of exhaustive activity in intestinal permeability. We observed an increase in ZO-1 and occludin in groups S-A/G and T with respect to S. There was also an increase of ZO-1 in the E group compared to S. However, Ala/Gln reversed the transcription of these tight junctions in groups T-A/G and E-A/G. Transcription of claudin-2 was reduced in the S-A/G, but we obtained and increase in the E group compared to a decrease of S and E-A/G against E. Regarding the PET-1 we showed increased transcription in groups T and E in relation to S. However, the Ala/Gln reversed the transcript of this dipeptide in group E-A/G with respect to E. An analysis 72 hours after the exhaustion test values found for intestinal permeability similar to sedentary group. The prolonged and exhaustive exercise altered intestinal permeability and chronic supplementation with Ala/Gln was protective against the increase. The possible mechanism of Ala/Gln refers to mechanical processes of cell-to-cell interaction (occludin and ZO-1) and/or electrolytic (claudin-2).

Longitudinal air permeability measurements of Douglas-fir [Pseudotsuga menziesii (Mirb.) Franco] outer sapwood from three trees of different seed sources and growth locations were determined on microsections about 500-700 microns thick, dried by air-seasoning and solvent-seasoning. The specimens were successively reduced in length from 3.6 to 0.4 cm. Darcy's law was found to be invalid with respect to specimen length. Sapwood earlywood longitudinal air permeability was found to be a sensitive barometer of seasoning effect on pit aspiration. The objective was to determine where the variations in margo porosity were significant, and hence applicable to problem of Douglas-fir permeability. The diameters of earlywood margo openings were measured directly from electron micrographs of un-aspirated (solvent-seasoned) pits. The margo measurement was assumed to represent one plane instead of the actual three dimensional structure, and the pores observed were the ones that controlled the rate of flow. Samples from the most, intermediately and least permeable specimens were selected and prepared for the evaluation of anatomical parameters of bordered pit membranes (margo area and margo porosity) as related to permeability. The effects of pit aspiration, tracheid length, total number of pits per tracheid, number of tracheids per square millimeter, and specific gravity on permeability were also assessed. Pit partial aspiration was found as the most important variable correlated with permeability. In an order of decreasing importance, pit partial aspiration, margo porosity and specific gravity together accounted for 94 per cent of total variability in permeability of solvent-seasoned earlywood. No statistical evaluations were made to compare the three trees with respect to their permeability and the measured parameters. / Forestry, Faculty of / Graduate

An apparatus was constructed to measure the longitudinal gas-permeability of wood microsections about 150 microns thick. This apparatus was used to examine low surface tension drying methods of wood (freeze-drying and alcohol-benzene extraction) believed to maintain the bordered pit tori of Douglas fir (Pseudotsuga menziesii (Mirb.) Franco) in the non-aspirated condition. Results were compared with drying methods believed to aspirate tori (air-drying, oven-drying and boiling-under-vacuum). Dry nitrogen gas-permeability measurements were made under "steady state" conditions. Similar drying techniques were used to prepare gross specimens which were subsequently subjected to “non-steady state" pressure treatment in end-penetration. Sapwood and heartwood specimens from impermeable interior-type and permeable coast-type Douglas fir were tested. With both gross sections and microsections, the two low surface tension drying methods provided more permeable wood than did air-drying. Boiling-under-vacuum was as effective as low surface tension methods in improving gas-permeability, but not creosote-permeability, whereas oven-drying was as effective as low surface tension methods in improving creosote-permeability, but not gas-permeability. The improvement was most striking in all sapwood samples, less in coast-type heartwood, and nil or not measurable in interior-type heartwood. Under the experimental conditions, latewood gas-permeability was about 2 darcies for all specimens and drying methods. Heartwood early-wood gas-permeability ranged from 0.02 to 2 darcies but was unaffected by drying methods. Sapwood earlywood gas-permeability was improved from 8 to 30 times by low surface tension drying. The greatest gas-permeability was found in the first-formed earlywood, which ranged from 2 to 100 darcies. The later-formed earlywood ranged from 0.02 to 100 darcies, depending on wood origin and drying method. Creosote-permeability of interior-type heartwood was uniformly low by all drying methods. Interior-type sapwood and coast-type sapwood and heartwood were much more permeable after low surface tension drying or oven-drying. By visual observations, after all drying methods, latewood was more permeable than earlywood. Low surface tension drying methods improve earlywood gas-permeability of sapwood, and latewood creosote-permeability of sapwood and coast-type heartwood. / Forestry, Faculty of / Graduate

No description available.

This study used petrographic thin sections, scanning electron microscopy, and confocal laser microscopy to document microbially mediated dissolution of carbonate reservoir rocks. The samples studied came from three carbonate units that are hydrocarbon reservoirs; the Salem, Sligo, and Smackover formations. These samples were inoculated with bacteria, and then treated with nutrient solutions followed by ethanol to promote generation of acetic acid by bacteria. Dissolution occurred in calcite-dominated rocks and in dolomitized rocks. Noticeable changes first occurred after nine weeks of ethanol treatment and significant change only occurred after twelve weeks of ethanol treatment. The size of the vuggy pores created increased from 1 µm or less to over 5 µm, and rarely over 10 µm, in length.