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Efeitos do envelhecimento e da atividade física regular em índices da variabilidade da freqüência cardíaca e da arritmia sinusal respiratória de homens saudáveis. / Effects of aging and physical activity on indices of the heart rate variability and respiratory sinus arrhythmia in healthy men.Melo, Ruth Caldeira 22 December 2004 (has links)
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Previous issue date: 2004-12-22 / Universidade Federal de Minas Gerais / The purpose of the present study was to evaluate the effects of the aging and the
regular physical activity on the autonomic control of heart rate (HR) at rest and during
deep breath test (DBT) in healthy men. Nine young sedentary (mean = 22.67 ±2.45
years), sixteen young active (mean = 22.38 ±2.13 years), eight sedentary older
(mean = 63.5 ±2.39 years) and eight older active (mean = 61 ±1.6 years) men were
studied. Electrocardiogram was continuously recorded during 15 minutes (rest), 4
minutes (DBT, with breath rate at 5 to 6 cycles/minute) and 1 minute (recovery) in
supine position. The HR (bpm) and the R-R intervals (RRi) (ms) were analyzed by
time (RMSSD index) and frequency domain methods. The power spectral
components were expressed as absolute (a) and normalized units (nu) at low (LF)
and high (HF), and as the LF/HF. The HR and the RRi were analyzed by the
respiratory sinus arrhythmia (RSA) indices: expiration/inspiration ratio (E/I) and
inspiration-expiration difference (∆IE). The HR was lower in the activity groups than
to the matched-age sedentary groups. The older sedentary group had lower heart
rate variability (HRV), E/I and ∆IE than young ones. The older active group showed
higher RMSSD and HF component than matched-age sedentary group (45.04 and
28.78 ms, 58,167 and 12,218 ms2/Hz, P<0.05; respectively). No differences were
found between young and older active groups for RMSSD (61.71 and 45.04 ms,
respectively) and HRV (TP:130,816 and 125,710, LFa:33,295 and 32,611,
HFa:84,346 and 58,167, ms2/Hz, respectively) and DBT indices (E/I: 1.40 and 1.35,
∆IE: 23 and 18, respectively). The results show that aging associates with inactivity
reduces the HRV. However, the regular physical activity increases the HRV,
independent of age, suggesting attenuation the effects of the aging in the autonomic
control of the heart rate. / O presente estudo teve como objetivo avaliar os efeitos da idade e da
atividade física regular sobre o controle autonômico da freqüência cardíaca (FC)
durante o repouso e durante a manobra para acentuar a arritmia sinusal respiratória
(MASR) em homens saudáveis. Participaram do presente estudo, 9 jovens
sedentários (média= 22,67 ±2,45 anos), 16 jovens ativos (média= 22,38 ±2,13 anos),
8 idosos sedentários (média= 63,5 ±2,39 anos) e 8 idosos ativos (média= 61 ±1,6
anos). O traçado eletrocardiográfico foi registrado durante 15 minutos (repouso com
respiração espontânea), 4 minutos (MASR, com freqüência respiratória mantida
entre 5 a 6 ciclos/minuto) e 1 minuto de recuperação. A freqüência cardíaca (FC),
em bpm, e os intervalos RR (iR-R), em ms, foram analisados pelo domínio do tempo
(índice RMSSD) e pelo domínio da freqüência. Os componentes da potência
espectral foram expressos em valores absolutos (a) e em unidades normalizadas
(un) para a densidade total de potência (DTP), as bandas de baixa freqüência (BF),
alta freqüência (AF) e razão BF/AF. A FC obtida durante a manobra MASR foi
analisada a partir dos índices: razão expiração/inspiração dos iR-R (E/I) e de sua
variação durante a inspiração-expiração (∆IE). Os grupos ativos apresentaram
valores inferiores de FC de repouso em comparação aos controles sedentários de
mesma idade. O grupo idoso sedentário apresentou menor variabilidade da
variabilidade da freqüência cardíaca (VFC), E/I e ∆IE que o grupo jovem sedentário.
O grupo idoso ativo mostrou valores superiores de RMSSD e da banda de HF em
relação ao grupo sedentário idoso (45,04 e 28,78 ms, 58.167 e 12.218 ms2/Hz,
p<0,05; respectivamente). Diferenças estatísticas não foram encontradas entre o
grupo jovem ativo e idoso ativo para o RMSSD (61,71 e 45,04 ms, respectivamente)
e para a VFC (DTP: 130.816 e 125.710, LFa: 33.295 e 32.611, HFa: 84.346 e
58.167, ms2/Hz, respectivamente) e para os índices da ASR (E/I: 1,40 e 1,35, ∆IE:
23 e 18, respectivamente). Para os grupos sedentários foi observado correlação
negativa entre os índices DTP, AFa, E/I e ∆IE e a idade (p<0,05), sendo que o
mesmo não pode ser observado nos grupos ativos. Os resultados sugerem que o
envelhecimento associado ao sedentarismo provoca reduções na VFC,
representadas pela diminuição da atividade vagal sobre o coração, determinada
tanto pela análise no domínio da freqüência como pelos índices da arritmia sinusal
respiratória. Entretanto, a atividade física regular aumenta a VFC,
independentemente da idade, e atenua as alterações, decorrentes do processo de
envelhecimento, no controle autonômico da freqüência cardíaca.
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Régulation de la fonction cardio-respiratoire au cours du cycle de vie de Nothobranchius furzeri : rôle de la température / Cardio-respiratory function during Nothobranchius furzeri life cycle : temperature impactDurollet, Marie 18 December 2015 (has links)
Le système cardio-respiratoire joue un rôle prépondérant au sein d’un organisme, en permettant notamment l’apport et la distribution du dioxygène et des nutriments à l’ensemble des cellules. Mieux comprendre les modifications du système cardio-respiratoire au cours de la vie est donc un élément central dans l’évaluation de la capacité de l’organisme à répondre à ses différents besoins énergétiques, ainsi que dans la compréhension du phénomène de mortalité naturelle liée à la sénescence. Cette étude a été réalisée sur un vertébré à durée de vie extrêmement courte (~6 mois), le poisson Nothobranchius furzeri. La température, en plus d’être considérée comme l’un des principaux facteurs environnementaux susceptibles d’influencer la physiologie des téléostéens, est connue pour son effet régulateur sur la longévité. Ainsi, les individus étaient acclimatés à deux températures, 26 °C considérée comme la température optimale chez cette espèce, et une température réduite de 22 °C. Au niveau individuel, les réponses biologiques ont été explorées au travers des performances physiologiques comme mesure indirecte de la fitness : la capacité métabolique aérobie (AS), la croissance, les performances de reproduction, de locomotion et de digestion. A l’échelle sub-individuelle, les mécanismes de régulation de la fonction cardiaque ont été examinés via une étude morpho-fonctionnelle des cardiomyocytes. Les résultats mettent en évidence la présence au cours de la vie de deux phases bien distinctes délimitées par un âge optimal : (1) une première phase d’élévation de l’AS des stades juvénile à adulte ; suivie (2) d’une seconde phase, synonyme de déclin de l’AS, des indicateurs cardiaques et des niveaux d’activités ciblés, associés probablement à l’entrée en sénescence. Une réduction de température accroit la longévité, et retarde les effets néfastes du vieillissement sur l’AS, et les performances cardiaques. Cette étude contribuera à établir une vision globale des effets du vieillissement sur la fonction cardio-respiratoire et à mieux comprendre les mécanismes mis en jeu lors d’un allongement de la longévité par une réduction de la température. / Cardio-respiratory system plays a key role in an organism by delivering oxygen and nutrients towards the cells. Exploring its age-dependant changes is therefore a corner stone for assessing the organism capacity to meet its energetic needs along its life cycle, and for the understanding of mechanisms involved in the mortality due to aging process. This study was realized in a vertebrate with an extremely short lifespan (~6 months), the fish Nothobranchius furzeri. Temperature is an external factor that regulates longevity. Here, fish were acclimatized at two temperatures, 26 °C considered as the optimal temperature for this species, and 22 °C. Biological responses of fish were evaluated at individual level through the assessment of aerobic metabolic scope (AS), growth, reproduction, locomotion and digestion, which are considered to be relevant indirect measurement of fitness. Furthermore, mechanisms involved in the cardiac function regulation were explored through a morpho-functional study of cardiomyocytes. Along the individual life cycle, two phases were emphasized: 1) the first corresponds to AS elevation from the juvenile to the adult stages, following by 2) a second phase reflecting the entrance in the senescent stage, characterized by the decline in AS, cardiac performances and in activity level. A temperature reduction increases the individual longevity and slows-down deleterious effect of aging on both AS and cardiac function. This study will contribute to provide a global vision of senescent effects on cardio-respiratory system, and a better understanding of the mechanisms involved in temperature-dependent increase in longevity.
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O Mestre em gerontologia e a perspectiva da própria velhiceCalderoni, Sila Zugman 09 October 2006 (has links)
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Previous issue date: 2006-10-09 / The contact with someone s old age mobilizes personal contents in middle-aged
professionals dealing with the elderly, which produces effects on these professionals´ own
lives. This research aimed at examining in what ways Masters in Gerontology conceive and
perceive their own ageing process and future old age in the light of their personal and
professional experiences.
Interviews were carried out with Masters from the Post-graduate Studies Program in Social
Gerontology, at PUC-SP, in the 40-60 age group and working in the area of Gerontology.
Through a qualitative approach, the interviews were open and organized in a matricial
reading for subsequent interpretation.
This study has shown that the interviewees contact with the ageing process and the
perspective of their own old age is a source of tension. Although they can already notice
signs of ageing in themselves, they have not yet fully realized any limitations in their daily
lives, despite half of the professionals interviewed having referred to a feeling of discomfort
as a result of the awareness that they will eventually move into the aged population group
themselves. Personal and professional experiences, all sorts of crises and suffering which
these Masters in Gerontology have been through play a major role in the views and feelings
they have towards their own ageing process. Paradoxically, they imagine themselves
growing old, but without the limitations that old age brings.
The knowledge acquired by the professionals interviewed associated with professional work
contributed not only to reduce anguish in relation to their own future but also to produce changes in
their daily practices, consequently helping improve their present life and future old age / O contato com a velhice do outro mobiliza conteúdos pessoais naqueles que se encontram
na meia-idade e trabalham com idosos, o que repercute sobre suas vidas. Esta pesquisa teve
como objetivo verificar como os Mestres em Gerontologia pensam e sentem o próprio
processo de envelhecimento e futura velhice à luz de seu percurso pessoal e profissional.
Entrevistei Mestres, titulados pelo Programa de Estudos Pós Graduados em Gerontologia
Social, da PUC-SP, que atuam profissionalmente na área da Gerontologia e se situam na
faixa etária entre 40 e 60 anos. Numa abordagem qualitativa, utilizei entrevistas abertas,
organizadas numa leitura matricial para posterior interpretação.
O estudo revelou que o contato dos entrevistados com o processo de envelhecimento e a
perspectiva da própria velhice constitui-se em fonte de tensão. Reconhecem em si sinais de
envelhecimento, mas ainda não percebem, em sua plenitude, restrições em seus cotidianos,
embora a metade dos entrevistados já refira a sensação de incômodo em face dessa
consciência. O percurso pessoal e profissional, as crises e os sofrimentos vividos, permeiam
as visões e sentimentos que os Mestres em Gerontologia, na meia-idade, têm em relação ao
seu próprio processo de envelhecimento e futura velhice. Paradoxalmente, sem perceber,
imaginam-se idosos, até longevos, mas sem as limitações da idade avançada.
Os conhecimentos adquiridos pelos estudos agregados ao trabalho profissional contribuíram
para acalmar angústias em relação ao próprio futuro e modificar práticas quotidianas, tendo a
função de contribuir para melhorar o presente e a futura velhice
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Alternating-Current Thin-Film Electroluminescent Device Characterization / Charakterizace tenkovrstvých elektroluminiscenčních součástekAhmed, Mustafa M. Abdalla January 2008 (has links)
Jádrem této disertační práce bylo studovat optické a elektrické charakteristiky tenkovrstvých elektroluminiscenčních součástek řízených střídavým proudem (ACTFEL) a zejména vliv procesu stárnutí luminiforů na jejich optické a elektrické vlastnosti. Cílem této studie měl být příspěvek ke zvýšení celkové účinnosti luminoforů, vyjádřené pomocí jasu, účinnosti a stability. Vzhledem k tomu, že současnou dominantní technologií plochých obrazovek je LCD, musí se další alternativní technologie plošných displejů porovnávat s LCD. Výhodou ACTFEL displejů proti LCD je lepší rozlišení, větší teplotní rozsah činnosti, větší čtecí úhel, či možnost čtení při mnohem vyšší intenzitě pozadí. Na druhou stranu je jejich nevýhodou vyšší energetická náročnost, problém s odpovídající barevností tří základních barev a podstatně vyšší napětí nutné pro činnost displeje. K dosažení tohoto cíle jsme provedli optická, elektrická a optoelektrická měření ACTFEL struktur a ZnS:Mn luminoforů. Navíc jsme studovali vliv dotování vrstvy pomocí KCl na chování mikrostruktury a na elektroluminiscenční vlastnosti (zejména na jas a světelnou účinnost) ZnS:Mn luminoforů. Provedli jsme i některá, ne zcela obvyklá, měření ACTFEL součástek. Vypočítali jsme i rozptylový poměr nabitých barevných center a simulovali transportní charakteristiky v ACTFEL součástkách. Studovali jsme vliv stárnutí dvou typů ZnS:Mn luminoforů (s vrstvou napařenou či získanou pomocí epitaxe atomových vrstev) monitorováním závislostí svítivost-napětí (L-V), velikost vnitřního náboje - elektrické pole luminoforu (Q-Fp) a kapacitance-napětí (C-V) ve zvolených časových intervalech v průběhu stárnutí. Provedli jsme krátkodobá i dlouhodobá měření a pokusili jsme se i o vizualizaci struktury luminoforu se subvlnovým rozlišením pomocí optického rastrovacího mikroskopu pracujícího v blízkém poli (SNOM). Na praktickém případu zeleného Zn2GeO4:Mn (2% Mn) ACTFEL displeje, pracujícího při 50 Hz, jsme také studovali stabilitu svítivosti pomocí měření závislosti svítivosti na napětí (L-V) a světelné účinnosti na napětí (eta-V). Přitom byl zhodnocen význam těchto charakteristik. Nezanedbatelnou a neoddělitelnou součástí této práce je i její pedagogický aspekt. Předložený text by mohl být využit i jako učebnice pro studenty na mé univerzitě v Lybii.
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