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Made available in DSpace on 2015-12-10T14:24:06Z (GMT). No. of bitstreams: 0 Previous issue date: 2015-06-09. Added 1 bitstream(s) on 2015-12-10T14:30:15Z : No. of bitstreams: 1 000852869.pdf: 540584 bytes, checksum: 876f75004ad5a8e7b7dbf74986332aea (MD5) Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) A assimetria temporal observada na física macroscópica se deve à configuração de entropia extremamente baixa do universo primordial. Apesar de a matéria estar muito quente e com uma temperatura uniforme naquele estágio, os graus de liberdade gravitacionais estavam em grande medida suprimidos, fato este que contribui para o baixo valor da entropia e está codificado no alto grau de simetria espacial (caráter aproximadamente Friedman-Lemaître-Robertson-Walker) da superfície de último espalhamento. Analisamos diferentes tentativas de explicar a origem de tal configuração especial. O paradigma inflacionário é testado com respeito a esse problema, e é concluído que a baixa entropia inicial não pode ser explicada dentro dele. Conclusões similares são obtidas com respeito a formulações estatísticas (i.e. antrópicas). Por outro lado, o paradigma conhecido como cosmologia cíclica conforme (CCC) se apresenta como uma nova alternativa que ultrapassa muitas das dificuldades enfrentadas pelos seus rivais, apesar de levantar suas próprias questões em aberto. Introduzimos o modelo juntamente com a estrutura matemática das geometrias de Cartan como um meio possível de atingir um melhor entendimento das condições de contorno cosmológicas. Um elemento que é crucial nessa análise é a modelagem de uma estrutura geométrica de Cartan sobre o espaço de de Sitter SOe(4,1)/SOe(3,1) com um parâmetro de comprimento variável. A introdução de um parâmetro de comprimento na cinemática é favorecida pela observação de uma constante cosmológica positiva e também desejável por motivos oriundos da gravitação quântica, devido à escala natural determinada pelo comprimento de Planck The observed T-asymmetry of macroscopic physics is traced back to the extremely low entropy configuration of the early universe. Although matter was very hot and with a uniform temperature at that stage, the gravitational degrees of freedom were largely suppressed, which fact contributes to the lowness of the entropy and is encoded in the high level of spatial symmetry (nearly Friedman-Lemître-Robertson-Walker character) of the last scattering surface. I analyze different attempts to explain the origin of such special configuration. The inflation paradigm is probed with respect to this problem, and it is concluded that the initial low entropy cannot be accounted for within it. Similar conclusions are reached with respect to statistical (i.e. anthropic) reasonings. On the other hand, the paradigm known as conformal cyclic cosmology (CCC) presents itself as a new alternative which surpasses many of the difficulties faced by its rivals, although raising its own open questions. I introduce the model together with the mathematical structure of Cartan geometries as a possible means of achieving a better understanding of cosmological boundary conditions. One element which is crucial in this analysis is the modeling of the Cartan geometric structure over a de Sitter space SOe(4,1)/SOe(3,1) with varying length parameter. The introduction of a length parameter in the kinematics is favored by the observation of a positive cosmological constant and also desirable for quantum gravity reasons, due to the natural scale set by Planck's constant

The objective of the study was to compare the efficacy and safety of frovatriptan and almotriptan in women with menstrually related migraine (IHS Classification of Headache disorders) enrolled in a multicenter, randomized, double-blind, cross-over study. Patients received frovatriptan 2.5 mg or almotriptan 12.5 mg in a randomized sequence: after treating 3 episodes of migraine in no more than 3 months with the first treatment, the patient was switched to the other treatment. 67 of the 96 female patients of the intention-to-treat population of the main study had regular menstrual cycles and were thus included in this subgroup analysis. 77 migraine attacks classified as related to menses were treated with frovatriptan and 78 with almotriptan. Rate of pain relief at 2 and 4 h was 36 and 53 % for frovatriptan and 41 and 50 % for almotriptan (p = NS between treatments). Rate of pain free at 2 and 4 h was 19 and 47 % with frovatriptan and 29 and 54 % for almotriptan (p = NS). At 24 h, 62 % of frovatriptan-treated and 67 % of almotriptan-treated patients had pain relief, while 60 versus 67 % were pain free (p = NS). Recurrence at 24 h was significantly (p

Background The cardiac left ventricle responds to pressure overloads with mechanisms culminating in irreversible structural/functional cardiac alterations (left ventricular hypertrophy and/or diastolic dysfunction), inducing myocardial cells to secrete natriuretic peptides (NT-proBNP) antagonists of the renin–angiotensin–aldosterone system. The aim of this study was to evaluate the diagnostic accuracy of serum NT-proBNP levels in order to detect structural/functional cardiac diseases assessed by echocardiography. Methods A total of 126 consecutive newly diagnosed, never before treated, hypertensive patients (30–67 years) were enrolled, and clinical, echocardiography parameters and biochemical data were collected. Our reference was the presence of structural/functional cardiac disease (CSFD) and our index text was the serum NT-proBNP levels. Results NT-proBNP levels in CSFD patients were ~ 2 times higher than in non-CSFD subjects (median 61 vs 29 ng/L, n = 50 and 76, respectively); in addition, 60% of CSFD subjects (only 14% of which with pathological levels, > 125 ng/L), and 30% without CSFD showed NT-proBNP concentrations higher than 50 ng/L. However, ROC curves demonstrated a low specificity (38%) (calculated at 90% sensitivity at a cut-off of 22.5 ng/L). Discussion NT-proBNP levels, as a screening tool for cardiac structural/functional disease, appear to be limited, because of the low specificity. However, the strong association between its concentration and the establishment of irreversible cardiac hypertrophy prompts successive studies aimed to ascertain the use of its serum levels as an early alert indicator of disease severity.

Blood pressure variability represents an independent risk factor for cardiovascular diseases. To detect possible blood pressure variability changes from fertile to menopausal status, we enrolled consecutively 219 women: 104 fertile women (46.6 +/- 3.4 years) and 115 menopausal women (53.9 +/- 3.98 years). We evaluated for each patient the body mass index (BMI), 24 h, daytime, night-time systolic and diastolic mean blood pressure values and blood pressure variability data by means of an Ambulatory Blood Pressure Monitoring device. We found a significant higher mean age, body mass index, systolic and diastolic 24 h, day and night-time blood pressure variability in menopausal women when compared to fertile women. Age and BMI were significantly correlated to most blood pressure variability data with the Spearman Rank test. The multivariate logistic regression with dichotomic variables showed that the menopausal status is independently correlated to 24 h systolic (p0.0005) and diastolic (p0.05) variability, systolic (p0.05) and diastolic (p0.05) daytime pressure variability and systolic night-time pressure variability (p0.05). Furthermore, we found independent correlations between age 24 h systolic (p0.05) and night-time diastolic blood pressure variability (p0.05), while the BMI was indepententely correlated to BMI 24h diastolic (p0.01), daytime systolic (p0.01) and diastolic (p0.05) blood pressure variability. These data show a significant increase of blood pressure variability in menopausal women when compared to fertile women, even after exclusion of confounding factors, such as aging and BMI. Menopausal status, aging and BMI increase may all, independently, contribute to the enhanced blood pressure variability we found in menopausal women.