Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 3 de 3
Filtrar
Mais filtros

Base de dados
Tipo de documento
Intervalo de ano de publicação
1.
Nature ; 464(7287): 384-7, 2010 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-20237564

RESUMO

Of the over 400 known exoplanets, there are about 70 planets that transit their central star, a situation that permits the derivation of their basic parameters and facilitates investigations of their atmospheres. Some short-period planets, including the first terrestrial exoplanet (CoRoT-7b), have been discovered using a space mission designed to find smaller and more distant planets than can be seen from the ground. Here we report transit observations of CoRoT-9b, which orbits with a period of 95.274 days on a low eccentricity of 0.11 +/- 0.04 around a solar-like star. Its periastron distance of 0.36 astronomical units is by far the largest of all transiting planets, yielding a 'temperate' photospheric temperature estimated to be between 250 and 430 K. Unlike previously known transiting planets, the present size of CoRoT-9b should not have been affected by tidal heat dissipation processes. Indeed, the planet is found to be well described by standard evolution models with an inferred interior composition consistent with that of Jupiter and Saturn.

2.
J Neonatal Perinatal Med ; 10(1): 63-70, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28304314

RESUMO

OBJECTIVE: To evaluate the duration of catheter stay, incidence of non-elective removal and rates of complications associated with peripherally inserted central catheters (PICCs) in relation to different catheter positions in extremely preterm infants (EPT, <28 weeks of gestation). METHODS: A retrospective analysis of Peripherally Inserted Central Catheters (PICCs) inserted in EPT infants over a 10-year period, from January 2004 through December 2013 (mean gestational age, 25.2 weeks; mean birth weight, 727 g). RESULTS: Of the 379 PICCs analyzed, the majority of lines (68%) were placed in the central position, and 259 PICCs (56%) were removed electively after fulfilment of the treatment. Significantly more PICCs in the lower extremities compared to the upper extremities were in central positions (86% vs 61%, p < 0.001, respectively). Significantly more PICCs that were removed electively after fulfilment of the treatment were in a central position compared to a non-central position (p < 0.001). Of the 166 catheters that were removed because of complications, most (71%) of them had mechanical problems, and 13% had sepsis resulting in an incidence rate of 4.4/1000 catheter days. CONCLUSION: PICCs inserted in the lower extremity were more likely to have a centrally placed tip position compared to PICC lines inserted in the upper extremities.


Assuntos
Infecções Relacionadas a Cateter/epidemiologia , Cateterismo Periférico/métodos , Remoção de Dispositivo/estatística & dados numéricos , Sepse/epidemiologia , Infecções Relacionadas a Cateter/etiologia , Cateterismo Periférico/efeitos adversos , Cateteres Venosos Centrais , Feminino , Idade Gestacional , Humanos , Incidência , Lactente Extremamente Prematuro , Recém-Nascido , Masculino , Estudos Retrospectivos , Sepse/etiologia
3.
Astrobiology ; 9(1): 1-22, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19203238

RESUMO

The discovery of extrasolar planets is one of the greatest achievements of modern astronomy. The detection of planets that vary widely in mass demonstrates that extrasolar planets of low mass exist. In this paper, we describe a mission, called Darwin, whose primary goal is the search for, and characterization of, terrestrial extrasolar planets and the search for life. Accomplishing the mission objectives will require collaborative science across disciplines, including astrophysics, planetary sciences, chemistry, and microbiology. Darwin is designed to detect rocky planets similar to Earth and perform spectroscopic analysis at mid-infrared wavelengths (6-20 mum), where an advantageous contrast ratio between star and planet occurs. The baseline mission is projected to last 5 years and consists of approximately 200 individual target stars. Among these, 25-50 planetary systems can be studied spectroscopically, which will include the search for gases such as CO(2), H(2)O, CH(4), and O(3). Many of the key technologies required for the construction of Darwin have already been demonstrated, and the remainder are estimated to be mature in the near future. Darwin is a mission that will ignite intense interest in both the research community and the wider public.


Assuntos
Exobiologia/métodos , Meio Ambiente Extraterreno , Origem da Vida , Planetas , Voo Espacial , Astronomia , Teorema de Bayes , Processamento de Imagem Assistida por Computador , Astronave , Espectrofotometria Infravermelho , Astros Celestes
SELEÇÃO DE REFERÊNCIAS
Detalhe da pesquisa