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The majority of massive disk galaxies in the local Universe show a stellar barred structure in their central regions, including our Milky Way1,2. Bars are supposed to develop in dynamically cold stellar disks at low redshift, as the strong gas turbulence typical of disk galaxies at high redshift suppresses or delays bar formation3,4. Moreover, simulations predict bars to be almost absent beyond z = 1.5 in the progenitors of Milky Way-like galaxies5,6. Here we report observations of ceers-2112, a barred spiral galaxy at redshift zphot ≈ 3, which was already mature when the Universe was only 2 Gyr old. The stellar mass (Mâ = 3.9 × 109 Mâ) and barred morphology mean that ceers-2112 can be considered a progenitor of the Milky Way7-9, in terms of both structure and mass-assembly history in the first 2 Gyr of the Universe, and was the closest in mass in the first 4 Gyr. We infer that baryons in galaxies could have already dominated over dark matter at z ≈ 3, that high-redshift bars could form in approximately 400 Myr and that dynamically cold stellar disks could have been in place by redshift z = 4-5 (more than 12 Gyrs ago)10,11.
RESUMO
A decisão de se recomendar exames, medidas cardioprotetoras ou terapêuticas para um paciente que irá ser submetido a uma cirurgia não cardíaca, em última análise, se torna um ato de equilíbrio entre as probabilidades estimadas de eficácia versus risco. Exemplo disso é a redução do número de exames pedidos no pré-operatório após a implementação das recomendações do American Callege af Cardiology (ACC) FaundatianlAmerican Heart Assaciatian (AHA). Nos pacientes candidatos à cirurgia de aorta, 88% eram submetidos a teste de estresse com imagem nuclear, 24% a cateterismo cardíaco e 24% à revascularização do miocárdio (CRVM) no pré-operatório. Com a implementação das recomendações, estes números caíram para 47, 11 e 2%, respectiva- mente. Os custos gerais da avaliação pré-operatória reduziram-se de U$ 1.087 para U$ 171. Ao mesmo tempo, o desfecho perioperatório foi melhor. O índice de morte/infarto do miocárdio caiu de 11 para 4%1. O objetivo deste artigo de atualização é discutir as principais recomendações da AHA/ACC e destacar a importância de sua aplicação no dia-a-dia do anestesiologista...
The decisian to recommend exams, heart-protective or therapeutic measures for a patient who will be submitted to a non-cardiac surgery, in the final analysis, becomes an act af balance between estimated probabilities af effectiveness versus risk. An example is the reduced number ot exams required in the preoperative period after implementing the recommendatians af the American Callege af Cardialagy (ACC) Foundation/American Heart Associatian (AHA). In patients candidates for aortic surgeries, 88% were submitted to nuclear image stress test, 24% to cardiac catheterism and 24% were submitted to myocardial revascularizatian (MR) in the preoperative period. By implementing the recommendations, these numbers dropped to 47%, 11% and 2% respectively. General costs of preoperative evaluatians reduced from U$I087 to U$171. At the same time, the perioperative outcame was better. The death/myocardial infarction rate dropped from 11% to 4%1. The purpase af this updating paper is to discuss the main recommendations af AHAIACC and to highlight the importance of their implementation the day-by-day af the anesthesiologist...
Assuntos
Humanos , Exame Físico , Procedimentos Cirúrgicos Operatórios/métodos , Eletrocardiografia , Teste de Esforço , Técnicas de Diagnóstico CardiovascularRESUMO
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