2 research outputs found
Cape Town solution in prolonged myocardial preservation: structural and ultrastructural study
This study deals with myocardial preservation after 24 hours of continuous, hypothermic and
oxygenated perfusion with Cape Town (CT) solution,
focusing on the morphological changes produced by
preservation and reperfusion, and their possible
relationship to the composition of the solution and the
immediate hemodynamic findings after orthotopic heart
transplantation in dogs. After preservation, aside from
mild or moderate mitochondrial changes, the most
relevant lesions included edema and vasoconstriction.
Reperfusion was followed by the development of areas
of necrosis forming contraction bands and an increment
in the mitochondrial damage ; the intercalated disks
conserved their normal structure; edema became more
prominent and was in variably accompanied by
hemorrhage; vasoconstriction was very pronounced and
was accompanied on occasion by evidence of capillary
rupture; and inflammatory cells were observed in the
interstitium. These results indicate that colloid must be
added to Cape Town solution and that reperfusion
probably requires selective approaches to deal with
vasoconstriction and inflammation
Preliminary wind analysis regarding different speed ranges in the city of La Plata, Argentina
La Plata city (approximately 800 000 inhabitants) has intense traffic and industrial activity; nevertheless, the city has no governmental air monitoring network for air pollutants and winds have been scarcely studied. Wind observations provided here (covering 1998- 2007) belong to a weather station that was contrasted against the unique governmental site in the city area (the Airport). The present preliminary study analyses wind direction frequencies according to wind speeds and emphasizes wind patters within the first hour after calm occurrences. Results show that independently of the wind speed, wind direction frequency roses are in general similar to each other. Low wind speeds may occur most of the time (on average 58.2 %) and together with calm occurrences (on average 17.1% ) constitute an important factor for the accumulation of air pollutants. The proposed "outgoing of calm" wind direction frequency roses were found to be appropriate to gain knowledge in the structure of winds that transport pollutants towards exposed population after calm occurrences. Long term systematic meteorological fieldworks should be encouraged in the future so as to provide better tools for environmental modeling.A cidade de La Plata (aproximadamente 800.000 habitantes) tem tráfego e atividade industrial intensos. Contudo, não tem uma rede oficial de monitoramento para os contaminantes do ar e os ventos têm sido pouco estudados. As observações dos ventos aqui apresentadas (desde 1998 até 2007) correspondem a uma estação meteorológica que foi comparada com o único sitio oficial de registros de ventos na área urbana (o Aeroporto). O presente estudo preliminar analisa as frequências das direções do vento, segundo as suas velocidades, e coloca ênfase nos padrões de vento na primeira hora após as ocorrências calmarias. Os resultados mostram que as rosas de frequências de direções de ventos são em geral similares entre elas independentemente das velocidades. Velocidades baixas de ventos são factíveis de acontecer na maior parte do tempo (na média 58,2%), e, junto com as ocorrências de calmarias (na média 17,1%), constitui um fator importante para acumulação dos contaminantes. As rosas de frequência de direções de ventos propostas, nomeadas "saída de calmarias", resultaram ser apropriadas para o conhecimento da estrutura dos ventos que transportam os contaminantes acumulados em direção à população exposta, após períodos de calmaria. Na meteorologia deveriam se incentivados os trabalhos de campo sistemáticos, de longo prazo, de forma a prover melhores ferramentas para a modelagem de meio ambiente