Thesis (M.Med.Sc.)--University of Hong Kong, 2000. / Includes bibliographical references (leaves 53-61). Also available in print.

In order to study quantitatively the acidity of very weak acids and at the same time the effect of a polar aprotic solvent on the basicity of hydroxide ion a Hammett H_ acidity function based on the ionization of 24 substituted anilines and diphenylamines has been established in the system dimethylsulfoxide-water-tetramethylammonium hydroxide. The basicity of hydroxide ion is increased dramatically as the solvent is changed from water to dimethylsulfoxide. The H_ of a 0.011 molar solution of tetramethylammonium hydroxide ranges from 12 in water to 26 in 99.6 mole % dimethylsul-foxide-water, an increase in basicity of fourteen powers of ten. The increase in basicity is due to the increased activity of the hydroxide ion brought about by the reduction in its solvation in the poor anion-solvating solvent, dimethyl sulfoxide and indicates the extensive solvation enjoyed by the hydroxide ion in water. The pKHA values of the indicator acids vary from 13.84 for 2,4-dinitrodiphenylamine to 25.63 for 3-chloroaniline. From a plot of log KHA versus Hammett substituent constants ( ϭ) for six monosubstituted diphenylamines a rho (ρ) value of 4.07 is found. The magnitude of substituent effects on the acidity of aniline appears to be quite similar. The acidities of all the substituted diphenylamines do not follow the above mentioned correlation with Hammett ϭconstants; the pKHA values of 4-amino-, 4-methoxy-, 4-methylsulfonyl-, and 4-nitrodiphenylamine are all less than expected from the Hammett ϭ constants for the substituents in these compounds. The 4-nitro substituent exerts a particularly large acid-strengthening effect on the acidities of aniline and diphenyl amine; the decreases in pKHA being approximately 8.4 and 6.8 pK units, respectively. The pKHA values of 17 compounds other than those indicators used to establish the H_ function have been determined with the aid of the H_ function. Most of these compounds are alkyl-substituted 4-nitroanilines. Alkyl groups ortho to the amino group of 4-nitroaniline cause a decrease in the pKHA (an increase in acidity). Similarly, N-methyl-, N-ethyl-, and N-isopropyl-4-mitro- aniline are all stronger acids than 4-nitroaniline itself. An explanation for the effects of alkyl substituents on the acidity of 4-nitroaniline in terms of the solvation of both the ionized and unionized amines is advanced. A Hammett Hₒ acidity function based on the protonation of 17 diphenylamines in 20 volume % ethanol-aqueous sulfuric acid has been established. The Hₒ value for the most acidic solution studied is -6.97 for 11.2 molar sulfuric acid. This acidity function differs from that based on the protonation of azobenzenes in the same solvent system; the latter acidity function diverges to more, negative Hₒ values as the sulfuric acid concentration increases. The pKBH+ values for the protonation of the diphenylamines vary from 1.36 for 4 methoxydiphenylamine to -6.21 for 4,4'-dinitrodiphenylamine. A plot, of log KBH+ versus Hammett ϭ constants for five mono-substituted diphenylamines yields a rho (ρ) value of.3.36. The pKBH+ values for 4-methoxy-, 4-methyl-, 4-methylsulfonyl-, and 4-nitro-diphenylamine are all less (morenegative) than expected from the Hammett substituent constants. Substituent effects on the basicities of aniline and diphenylamine are the same. This is evident from the fact, that a plot of the pKBH+ values of 11 diphenylamines versus the pKBH+ values of the corresponding anilines yields a good straight line with slope 1.01. The basicities of several nitro-substituted diphenylamines appear to vary regularly and do not reflect the presence of a strong interaction between the nitro group and sulfuric acid. A plot of the acidity versus the basicity (pKHA versus pKBH+) for nine diphenylamines yields, a straight line with slope 1.30. In a similar plot for 33 substituted anilines and diphenylamines two types of behaviour are observed. Those anilines and diphenylamines without an ortho or para hitro group fall about the line with slope 1.30 while those amines with at least one nitro group in the ortho or para position fall on a different, curved line with a slope of less than unity. / Science, Faculty of / Chemistry, Department of / Graduate

Akademisk avhandling--København. / Dansk resumé. Bibliography: p. [205]-228.

Akademisk avhandling--København. / Dansk resumé. Bibliography: p. [205]-228.

Orientador: Alessandro Moura Zagatto / Coorientador: Marcelo Papoti / Banca: Bruno Gualano / Banca: Bryan Saunders / Banca: Fúlvia de Barros Manchado Gobatto / Banca: Eduardo Zapaterra Campos / Resumo: O objetivo da presente tese foi verificar a influência da suplementação de β-Alanina associado ao treinamento intervalado de alta intensidade (HIIT) na performance de sprints repetidos. Participaram do estudo conduzido em caráter randomizado e duplo-cego, 20 jovens saudáveis alocados em dois grupos (Gβ [n = 10] - 6,4 g.dia-1 de β-Alanina; GP [n = 10] - 6,4 g.dia-1 de dextrose - placebo). Os participantes foram avaliados em três momentos distintos, previamente ao início, após quatro semanas de HIIT sem suplementação e após 6 semanas de suplementação + HIIT. As avaliações foram compostas por teste incremental até exaustão (TINC); séries de 12 sprints repetidos (RSA); e teste de tempo limite até exaustão a 115% da velocidade máxima atingida no TINC (TLIM). Previamente e imediatamente após TINC e RSA foram realizadas avaliações neuromusculares compostas por saltos verticais máximos, contrações isométricas máximas de extensão de joelho e estimulação elétrica periférica. O HIIT foi composto de dez corridas de 1 min a 90% da velocidade máxima atingida no TINC, com 1 min de recuperação passiva entre as corridas e frequência de 3 sessões semanais. Previamente ao início da suplementação + HIIT e ao final da intervenção, os participantes foram submetidos a biópsias musculares para determinação do conteúdo de carnosina intramuscular, capacidade de tamponamento in vitro e conteúdo de proteínas/enzimas chaves. Após a intervenção, ambos os grupos melhoraram o metabolismo oxidativo (i.e., co... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The aim of the present thesis was to verify the influence of β-Alanine supplementation associated with high intensity interval training (HIIT) on the performance of repeated sprints. The study was conducted in a randomized, double-blind design and 20 healthy young men were allocated in two groups (Gβ [n = 10] - 6.4 g.day-1 of β-Alanine; GP [n = 10] - 6.4 g.day-1 of dextrose - placebo). The participants were evaluated at three different moments, prior to beginning, after four weeks of HIIT without supplementation and after 6 weeks of supplementation + HIIT. The evaluations were composed by incremental test until exhaustion (TINC); set of 12 repeated sprints (RSA); and time-to-exhaustion test at 115% of the maximum velocity achieved in TINC (TLIM). Previously and immediately after TINC and RSA, neuromuscular evaluations were performed, consisting of maximum vertical jumps, maximal voluntary isometric contractions of knee extension and peripheral electrical stimulation. The HIIT was composed by ten runs of 1-min at 90% of the maximum velocity achieved in TINC, with 1-min of passive recovery between runs and frequency of 3 sessions per week. Prior to the initiation of supplementation + HIIT and at the end of the intervention, the participants underwent muscle biopsies to determine intramuscular carnosine content, muscle buffer capacity in vitro and key protein/enzyme content. After the intervention, both groups improved oxidative metabolism (i.e., maximal oxygen uptake), however, only Gβ significantly improved the intramuscular carnosine content and the RSA variables; in addition to presenting attenuation of the neuromuscular fatigue induced by the RSA. No significant differences were observed in anaerobic capacity, muscle buffer capacity in vitro and key protein/enzyme content. Thus, the association between β-Alanine supplementation and HIIT provided significant improvement in repeated sprints performan / Doutor

Thesis (doctoral)--University of Lund.

Thesis (Ph. D.)--Virginia Polytechnic Institute and State University, 1995. / Vita. Abstract. Includes bibliographical references. Also available via the Internet.

Thesis--University of Copenhagen. / Also published in Acta Physiologica Scandinavica, Supplementum, 324. Summary in Danish. Bibliography: p. 105-110.

Thesis--University of Wisconsin. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 89-93).

Orientador: Lizandra Amoroso / Resumo: A urolitíase é enfermidade com importância econômica para a ovinocultura, que causa a saída prematura de ovinos machos destinados à reprodução, custos com tratamento e morte. A associação entre avaliação hemogasométrica, pesquisa de proteínas de fase aguda (PFA) como biomarcadores precoces e o estudo morfométrico do trato urinário pode ser empregada como método de auxílio diagnóstico precoce para a doença. Com esse objetivo, foram utilizados 14 ovinos hígidos, machos (não castrados), da raça Santa Inês com idade aproximada de 90 dias. Os ovinos receberam dieta experimental hiperfosfórica durante todo o período experimental, foram examinados semanalmente e após desenvolvimento da urolitíase, reorganizados em dois grupos experimentais distintos D1 (sem urolitíase) e D2 (com urolitíase) para análise comparada dos dados. No período pré-experimental e no dia do abate foram coletadas amostras de sangue venoso para avaliação hemogasométrica. Para mensurar as imunoglobulinas (A e G) e as PFA, analisaram-se as amostras dos ovinos que desenvolveram a urolitíase (D2). As coletas de sangue foram realizadas semanalmente até a manifestação clínica da enfermidade, totalizando 16 amostras. Ao término do experimento foi realizado o abate e necropsia dos ovinos, para descrição das alterações patológicas e a análise morfométrica. Fragmentos do trato urinário e fígado foram coletados e submetidos à rotina histológica e as lâminas histológicas foram descritas, seguindo-se a histomorfometria. Embo... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Urolithiasis is an economically important disease for male sheep production that causes the premature calving of sheep for breeding, treatment costs and death. The association between hemogasometric evaluation, acute phase protein (APP) research as early biomarkers and urinary tract morphometric study can be employed as an early diagnostic aid for the disease. For this purpose, 14 healthy male (non-castrated) Santa Inês sheep, approximately 90 days old, were used. Sheep received a hyperphosphoric experimental diet throughout the experimental period, were examined weekly and after development of urolithiasis, reorganized into two distinct experimental groups D1 (without urolithiasis) and D2 (with urolithiasis) for comparative analysis of the data. In the pre-experimental period and on the day of slaughter, venous blood samples were collected for hemogasometric evaluation. To measure immunoglobulins (A and G) and APP, samples from sheep that developed urolithiasis (D2) were analyzed. Blood samples were collected weekly until the clinical manifestation of the disease, totaling 16 samples. At the end of the experiment, sheep were slaughtered and necropsied to describe the pathological changes and the morphometric analysis. Urinary tract and liver fragments were collected and submitted to histological routine and histological slides were described, followed by histomorphometry. Although blood pH was not different (P < 0.05) between groups, sheep that developed urolithiasis had com... (Complete abstract click electronic access below) / Doutor