34 research outputs found
Adjuvant-induced autoimmune syndrome triggered by silicone breast implants: systematic review
Adjuvant-induced autoimmune syndrome (ASIA) and its diagnostic criteria were described by Shoenfeld in 2011, relating symptoms of autoimmunity to adjuvants, such as silicone, present in breast implants. This systematic review aimed to gather data from the literature on symptomatology, incidence and proposed treatments for ASIA caused by silicone breast implants (SBI). Searches were carried out in PubMed, LILACS, Embase and Cochrane databases, using the descriptors “Autoimmune Syndrome Induced by Adjuvants,” “Breast implant,” and “Silicone Implant Incompatibility Syndrome.” The search strategy generated 95 articles, of which 20 were included in the review. The authors suggest three main theories to explain the development of the syndrome: genetic predisposition, silicone bleeding and the formation of a periprosthetic capsule. The most frequently described clinical manifestations include chronic fatigue, arthralgia, myalgia, and cognitive and sleep disorders. There is no consensus on laboratory findings and associated risk factors; recent studies propose expanding the diagnostic criteria initially described. Adequate treatment remains controversial, ranging from medications to prosthesis explantation. Although the reviewed articles suggest the existence of ASIA related to SBI, its precise pathophysiology is unknown, the symptoms reported are nonspecific, and the time between exposure and the onset of manifestations is uncertain. This systematic review concludes that, to date, there is not enough scientific evidence to establish the causality of the development of adjuvant-induced autoimmune syndrome resulting from silicone breast implants
The Quiescent Intracluster Medium in the Core of the Perseus Cluster
Clusters of galaxies are the most massive gravitationally-bound objects in
the Universe and are still forming. They are thus important probes of
cosmological parameters and a host of astrophysical processes. Knowledge of the
dynamics of the pervasive hot gas, which dominates in mass over stars in a
cluster, is a crucial missing ingredient. It can enable new insights into
mechanical energy injection by the central supermassive black hole and the use
of hydrostatic equilibrium for the determination of cluster masses. X-rays from
the core of the Perseus cluster are emitted by the 50 million K diffuse hot
plasma filling its gravitational potential well. The Active Galactic Nucleus of
the central galaxy NGC1275 is pumping jetted energy into the surrounding
intracluster medium, creating buoyant bubbles filled with relativistic plasma.
These likely induce motions in the intracluster medium and heat the inner gas
preventing runaway radiative cooling; a process known as Active Galactic
Nucleus Feedback. Here we report on Hitomi X-ray observations of the Perseus
cluster core, which reveal a remarkably quiescent atmosphere where the gas has
a line-of-sight velocity dispersion of 164+/-10 km/s in a region 30-60 kpc from
the central nucleus. A gradient in the line-of-sight velocity of 150+/-70 km/s
is found across the 60 kpc image of the cluster core. Turbulent pressure
support in the gas is 4% or less of the thermodynamic pressure, with large
scale shear at most doubling that estimate. We infer that total cluster masses
determined from hydrostatic equilibrium in the central regions need little
correction for turbulent pressure.Comment: 31 pages, 11 Figs, published in Nature July
Hitomi (ASTRO-H) X-ray Astronomy Satellite
The Hitomi (ASTRO-H) mission is the sixth Japanese x-ray astronomy satellite developed by a large international collaboration, including Japan, USA, Canada, and Europe. The mission aimed to provide the highest energy resolution ever achieved at E > 2 keV, using a microcalorimeter instrument, and to cover a wide energy range spanning four decades in energy from soft x-rays to gamma rays. After a successful launch on February 17, 2016, the spacecraft lost its function on March 26, 2016, but the commissioning phase for about a month provided valuable information on the onboard instruments and the spacecraft system, including astrophysical results obtained from first light observations. The paper describes the Hitomi (ASTRO-H) mission, its capabilities, the initial operation, and the instruments/spacecraft performances confirmed during the commissioning operations for about a month
Hitomi X-Ray Studies of Giant Radio Pulses from the Crab Pulsar
To search for giant X-ray pulses correlated with the giant radio pulses (GRPs) from the Crab pulsar, we performed a simultaneous observation of the Crab pulsar with the X-ray satellite Hitomi in the 2300 keV band and the Kashima NICT radio telescope in the 1.41.7 GHz band with a net exposure of about 2 ks on 2016 March 25, just before the loss of the Hitomi mission. The timing performance of the Hitomi instruments was confirmed to meet the timing requirement and about 1000 and 100 GRPs were simultaneously observed at the main pulse and inter-pulse phases, respectively, and we found no apparent correlation between the giant radio pulses and the X-ray emission in either the main pulse or inter-pulse phase. All variations are within the 2 fluctuations of the X-ray fluxes at the pulse peaks, and the 3 upper limits of variations of main pulse or inter-pulse GRPs are 22% or 80% of the peak flux in a 0.20 phase width, respectively, in the 2300 keV band. The values for main pulse or inter-pulse GRPs become 25% or 110%, respectively, when the phase width is restricted to the 0.03 phase. Among the upper limits from the Hitomi satellite, those in the 4.510 keV and 70300 keV bands are obtained for the first time, and those in other bands are consistent with previous reports. Numerically, the upper limits of the main pulse and inter-pulse GRPs in the 0.20 phase width are about (2.4 and 9.3) 10(exp 11) erg cm(exp 2), respectively. No significant variability in pulse profiles implies that the GRPs originated from a local place within the magnetosphere. Although the number of photon-emitting particles should temporarily increase to account for the brightening of the radio emission, the results do not statistically rule out variations correlated with the GRPs, because the possible X-ray enhancement may appear due to a >0.02% brightening of the pulse-peak flux under such conditions
Viral RNA Degradation and Diffusion Act as a Bottleneck for the Influenza A Virus Infection Efficiency
The Astro-H High Resolution Soft X-Ray Spectrometer
We present the overall design and performance of the Astro-H (Hitomi) Soft X-Ray Spectrometer (SXS). The instrument uses a 36-pixel array of x-ray microcalorimeters at the focus of a grazing-incidence x-ray mirror Soft X-Ray Telescope (SXT) for high-resolution spectroscopy of celestial x-ray sources. The instrument was designed to achieve an energy resolution better than 7 eV over the 0.3-12 keV energy range and operate for more than 3 years in orbit. The actual energy resolution of the instrument is 4-5 eV as demonstrated during extensive ground testing prior to launch and in orbit. The measured mass flow rate of the liquid helium cryogen and initial fill level at launch predict a lifetime of more than 4 years assuming steady mechanical cooler performance. Cryogen-free operation was successfully demonstrated prior to launch. The successful operation of the SXS in orbit, including the first observations of the velocity structure of the Perseus cluster of galaxies, demonstrates the viability and power of this technology as a tool for astrophysics
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The ASTRO-H (Hitomi) x-ray astronomy satellite
The Hitomi (ASTRO-H) mission is the sixth Japanese X-ray astronomy satellite developed by a large international collaboration, including Japan, USA, Canada, and Europe. The mission aimed to provide the highest energy resolution ever achieved at E > 2 keV, using a microcalorimeter instrument, and to cover a wide energy range spanning four decades in energy from soft X-rays to gamma-rays. After a successful launch on 2016 February 17, the spacecraft lost its function on 2016 March 26, but the commissioning phase for about a month provided valuable information on the on-board instruments and the spacecraft system, including astrophysical results obtained from first light observations. The paper describes the Hitomi (ASTRO-H) mission, its capabilities, the initial operation, and the instruments/spacecraft performances confirmed during the commissioning operations for about a month
Search for thermal X-ray features from the Crab nebula with the Hitomi soft X-ray spectrometer
The Crab nebula originated from a core-collapse supernova (SN) explosion
observed in 1054 A.D. When viewed as a supernova remnant (SNR), it has an
anomalously low observed ejecta mass and kinetic energy for an Fe-core collapse
SN. Intensive searches were made for a massive shell that solves this
discrepancy, but none has been detected. An alternative idea is that the SN1054
is an electron-capture (EC) explosion with a lower explosion energy by an order
of magnitude than Fe-core collapse SNe. In the X-rays, imaging searches were
performed for the plasma emission from the shell in the Crab outskirts to set a
stringent upper limit to the X-ray emitting mass. However, the extreme
brightness of the source hampers access to its vicinity. We thus employed
spectroscopic technique using the X-ray micro-calorimeter onboard the Hitomi
satellite. By exploiting its superb energy resolution, we set an upper limit
for emission or absorption features from yet undetected thermal plasma in the
2-12 keV range. We also re-evaluated the existing Chandra and XMM-Newton data.
By assembling these results, a new upper limit was obtained for the X-ray
plasma mass of <~ 1Mo for a wide range of assumed shell radius, size, and
plasma temperature both in and out of the collisional equilibrium. To compare
with the observation, we further performed hydrodynamic simulations of the Crab
SNR for two SN models (Fe-core versus EC) under two SN environments (uniform
ISM versus progenitor wind). We found that the observed mass limit can be
compatible with both SN models if the SN environment has a low density of <~
0.03 cm-3 (Fe core) or <~ 0.1 cm-3 (EC) for the uniform density, or a
progenitor wind density somewhat less than that provided by a mass loss rate of
10-5 Mo yr-1 at 20 km s-1 for the wind environment.Comment: PASJ in press. Figures are now properly include