RESUMO
Since their discovery in 20071, much effort has been devoted to uncovering the sources of the extragalactic, millisecond-duration fast radio bursts (FRBs)2. A class of neutron stars known as magnetars is a leading candidate source of FRBs3,4. Magnetars have surface magnetic fields in excess of 1014 gauss, the decay of which powers a range of high-energy phenomena5. Here we report observations of a millisecond-duration radio burst from the Galactic magnetar SGR 1935+2154, with a fluence of 1.5 ± 0.3 megajansky milliseconds. This event, FRB 200428 (ST 200428A), was detected on 28 April 2020 by the STARE2 radio array6 in the 1,281-1,468 megahertz band. The isotropic-equivalent energy released in FRB 200428 is 4 × 103 times greater than that of any radio pulse from the Crab pulsar-previously the source of the brightest Galactic radio bursts observed on similar timescales7. FRB 200428 is just 30 times less energetic than the weakest extragalactic FRB observed so far8, and is drawn from the same population as the observed FRB sample. The coincidence of FRB 200428 with an X-ray burst9-11 favours emission models that describe synchrotron masers or electromagnetic pulses powered by magnetar bursts and giant flares3,4,12,13. The discovery of FRB 200428 implies that active magnetars such as SGR 1935+2154 can produce FRBs at extragalactic distances.
RESUMO
ECG and central hemodynamic parameters were examined in 24 patients with chronic ischemia of lower extremities under the effect of a course of hyperbaric oxygenation, and were shown to be improved in 67% of the cases. Deteriorating ECG pattern in combination with unfavorable central hemodynamic changes, seen in 29%, suggest that electrocardiographic monitoring is essential during the hyperbaric oxygenation course, so that treatment regimen could be timely adjusted.
Assuntos
Circulação Coronária , Hemodinâmica , Oxigenoterapia Hiperbárica , Isquemia/fisiopatologia , Perna (Membro)/irrigação sanguínea , Adulto , Idoso , Doença Crônica , Humanos , Isquemia/cirurgia , Pessoa de Meia-Idade , Cuidados Pré-OperatóriosRESUMO
A comparison is made of results of conservative treatment of 123 patients with ischemia of lower extremities of atherosclerotic genesis. It was shown that the maximum efficiency of the treatment was achieved by an associated application of pharmacological drugs and HBO. An analysis of angiograms has shown that the absence of collaterals is one of the causes of the HBO being inefficient.