Estima-se que metade das internações de pessoas vivendo com HIV/Aids (PVHA) em Unidade de Terapia Intensiva (UTI) estão relacionadas a causas não atribuídas ao HIV. No entanto, em países em ...desenvolvimento, os internamentos de PVHA ocorrem principalmente, por infecções oportunistas.
Analisar a evolução de pacientes HIV positivos, internados em um hospital de doenças infecciosas no Nordeste do Brasil. Métodos: Coorte retrospectiva, de pacientes HIV positivos internados na UTI do Hospital São José de Doenças Infecciosas (HSJ), no Estado do Ceará, no período de Janeiro de 2018 a Janeiro de 2019. Os dados foram coletados através da revisão de prontuários, e analisados através do STATA 13.0. O desfecho primário considerado foi a mortalidade.
No período do estudo, 86 pacientes foram incluídos. A densidade de incidência foi de 3,4 pacientes-dia. A maioria era do sexo masculino (73,3%), e a mediana de idade foi de 38,5 anos IIQ = 30-49; 62,8% dos pacientes tiveram o diagnóstico de infecção pelo HIV durante o internamento. As principais disfunções orgânicas na admissão à UTI observadas foram: respiratória (85,9%), neurológica (37,2%) e cardiovascular (10,5%). Em relação ao escore APACHE, foi observada uma mediana de 19,5 pontos IIQ = 14-24.Os diagnósticos mais frequentemente reportados na admissão foram sepse pulmonar (51,1%), pneumocistose (34,8%) e neurotoxoplasmose (30,2%). Insuficiência renal aguda (29,6%) e diarreia (12,4%) ocorreram como principais complicações na UTI; 43% dos pacientes foram a óbito, enquanto 57% receberam alta. A mediana em dias do tempo de permanência na UTI foi semelhante entre os pacientes que receberam alta e aqueles que foram a óbito (12 vs. 13; p = 0,746), assim como, a mediana da contagem de linfócitos T CD4+ (43 vs. 44 céls/mm3) e de carga viral do HIV (57.091 vs. 88.121 cópias/mm3). Não houve nenhum fator de risco relacionado à mortalidade quando se investigou fatores como comorbidades, disfunções orgânicas, tempo de ventilação mecância, e parâmetros laboratoriais. A sobrevida estimada em 28 dias foi de 40%.
Pacientes HIV positivos internados em UTI apresentam alto risco para uma evolução desfavorável, principalmente no contexto do diagnóstico tardio da infecção pelo HIV. A presença de disfunções orgânicas como a respiratória e neurológica, refletem a elevada prevalência de infecções oportunistas nestes pacientes.
Abstract
The blazar J1924–2914 is a primary Event Horizon Telescope (EHT) calibrator for the Galactic center’s black hole Sagittarius A*. Here we present the first total and linearly polarized ...intensity images of this source obtained with the unprecedented 20
μ
as resolution of the EHT. J1924–2914 is a very compact flat-spectrum radio source with strong optical variability and polarization. In April 2017 the source was observed quasi-simultaneously with the EHT (April 5–11), the Global Millimeter VLBI Array (April 3), and the Very Long Baseline Array (April 28), giving a novel view of the source at four observing frequencies, 230, 86, 8.7, and 2.3 GHz. These observations probe jet properties from the subparsec to 100 pc scales. We combine the multifrequency images of J1924–2914 to study the source morphology. We find that the jet exhibits a characteristic bending, with a gradual clockwise rotation of the jet projected position angle of about 90° between 2.3 and 230 GHz. Linearly polarized intensity images of J1924–2914 with the extremely fine resolution of the EHT provide evidence for ordered toroidal magnetic fields in the blazar compact core.
In April 2019, the Event Horizon Telescope (EHT) Collaboration reported the first-ever event-horizon-scale images of a black hole, resolving the central compact radio source in the giant elliptical ...galaxy M 87. These images reveal a ring with a southerly brightness distribution and a diameter of ∼42 μas, consistent with the predicted size and shape of a shadow produced by the gravitationally lensed emission around a supermassive black hole. These results were obtained as part of the April 2017 EHT observation campaign, using a global very long baseline interferometric radio array operating at a wavelength of 1.3 mm. Here, we present results based on the second EHT observing campaign, taking place in April 2018 with an improved array, wider frequency coverage, and increased bandwidth. In particular, the additional baselines provided by the Greenland telescope improved the coverage of the array. Multiyear EHT observations provide independent snapshots of the horizon-scale emission, allowing us to confirm the persistence, size, and shape of the black hole shadow, and constrain the intrinsic structural variability of the accretion flow. We have confirmed the presence of an asymmetric ring structure, brighter in the southwest, with a median diameter of 43.3
−3.1
+1.5
μas. The diameter of the 2018 ring is remarkably consistent with the diameter obtained from the previous 2017 observations. On the other hand, the position angle of the brightness asymmetry in 2018 is shifted by about 30° relative to 2017. The perennial persistence of the ring and its diameter robustly support the interpretation that the ring is formed by lensed emission surrounding a Kerr black hole with a mass ∼6.5 × 10
9
M
⊙
. The significant change in the ring brightness asymmetry implies a spin axis that is more consistent with the position angle of the large-scale jet.
Context.
The existence of warm (protoplanetary) disks around very young isolated planetary and brown dwarf mass objects is known based on near- and mid-infrared flux excesses and millimeter ...observations. These disks may later evolve into debris disks or rings, although none have been observed or confirmed so far. Little is known about circum(sub)stellar and debris disks around substellar objects.
Aims.
We aim to investigate the presence of debris disks around two of the closest (~20 pc), young substellar companions, namely G196-3 B and VHS J125601.92–125723.9 b (VHS J1256–1257 b), whose masses straddle the borderline between planets and brown dwarfs. Both are companions at wide orbits (≥100 au) of M-type dwarfs and their ages (50–100 Myr and 150–300 Myr, respectively) are thought to be adequate for the detection of second-generation disks.
Methods.
We obtained deep images of G196-3 B and VHS J1256–1257 b with the NOrthern Extended Millimeter Array (NOEMA) at 1.3 mm. These data were combined with recently published Atacama Large Millimeter Array (ALMA) and Very Large Array (VLA) data of VHS J1256–1257 b at 0.87 mm and 0.9 cm, respectively.
Results.
Neither G196-3 B nor VHS J1256–1257 b were detected in the NOEMA, ALMA, and VLA data. At 1.3 mm, we imposed flux upper limits of 0.108 mJy (G196-3 B) and 0.153 mJy (VHS J1256–1257 b) with a 3-
σ
confidence. Using the flux upper limits at the millimeter and radio wavelength regimes, we derived maximum values of 1.38×10
−2
M
Earth
and 5.46 × 10
−3
M
Earth
for the mass of any cold dust that might be surrounding G196-3 B and VHS J1256–1257 b, respectively.
Conclusions.
We put our results in the context of other deep millimeter observations of free-floating and companion objects with substellar masses smaller than 20
M
Jup
and ages between approximately one and a few hundred million years. Only two very young (2–5.4 Myr) objects are detected out of a few tens of them. This implies that the disks around these very low-mass objects must have small masses, and possibly reduced sizes, in agreement with findings by other groups. If debris disks around substellar objects scale down (in mass and size) in a similar manner as protoplanetary disks do, millimeter observations of moderately young brown dwarfs and planets must be at least two orders of magnitude deeper to be able to detect and characterize their surrounding debris disks.
Abstract The Event Horizon Telescope observed the horizon-scale synchrotron emission region around the Galactic center supermassive black hole, Sagittarius A* (Sgr A*), in 2017. These observations ...revealed a bright, thick ring morphology with a diameter of 51.8 ± 2.3 μ as and modest azimuthal brightness asymmetry, consistent with the expected appearance of a black hole with mass M ≈ 4 × 10 6 M ⊙ . From these observations, we present the first resolved linear and circular polarimetric images of Sgr A*. The linear polarization images demonstrate that the emission ring is highly polarized, exhibiting a prominent spiral electric vector polarization angle pattern with a peak fractional polarization of ∼40% in the western portion of the ring. The circular polarization images feature a modestly (∼5%–10%) polarized dipole structure along the emission ring, with negative circular polarization in the western region and positive circular polarization in the eastern region, although our methods exhibit stronger disagreement than for linear polarization. We analyze the data using multiple independent imaging and modeling methods, each of which is validated using a standardized suite of synthetic data sets. While the detailed spatial distribution of the linear polarization along the ring remains uncertain owing to the intrinsic variability of the source, the spiraling polarization structure is robust to methodological choices. The degree and orientation of the linear polarization provide stringent constraints for the black hole and its surrounding magnetic fields, which we discuss in an accompanying publication.
Abstract In a companion paper, we present the first spatially resolved polarized image of Sagittarius A* on event horizon scales, captured using the Event Horizon Telescope, a global very long ...baseline interferometric array operating at a wavelength of 1.3 mm. Here we interpret this image using both simple analytic models and numerical general relativistic magnetohydrodynamic (GRMHD) simulations. The large spatially resolved linear polarization fraction (24%–28%, peaking at ∼40%) is the most stringent constraint on parameter space, disfavoring models that are too Faraday depolarized. Similar to our studies of M87*, polarimetric constraints reinforce a preference for GRMHD models with dynamically important magnetic fields. Although the spiral morphology of the polarization pattern is known to constrain the spin and inclination angle, the time-variable rotation measure (RM) of Sgr A* (equivalent to ≈46° ± 12° rotation at 228 GHz) limits its present utility as a constraint. If we attribute the RM to internal Faraday rotation, then the motion of accreting material is inferred to be counterclockwise, contrary to inferences based on historical polarized flares, and no model satisfies all polarimetric and total intensity constraints. On the other hand, if we attribute the mean RM to an external Faraday screen, then the motion of accreting material is inferred to be clockwise, and one model passes all applied total intensity and polarimetric constraints: a model with strong magnetic fields, a spin parameter of 0.94, and an inclination of 150°. We discuss how future 345 GHz and dynamical imaging will mitigate our present uncertainties and provide additional constraints on the black hole and its accretion flow.
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