| 1. |
- Watts, Anna L., et al.
(författare)
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Dense matter with eXTP
- 2019
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Ingår i: Science China Physics, Mechanics & Astronomy. - : Science Press. - 1674-7348 .- 1869-1927. ; 62:2
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Forskningsöversikt (refereegranskat)abstract
- In this White Paper we present the potential of the Enhanced X-ray Timing and Polarimetry (eXTP) mission for determining the nature of dense matter; neutron star cores host an extreme density regime which cannot be replicated in a terrestrial laboratory. The tightest statistical constraints on the dense matter equation of state will come from pulse profile modelling of accretion-powered pulsars, burst oscillation sources, and rotation-powered pulsars. Additional constraints will derive from spin measurements, burst spectra, and properties of the accretion flows in the vicinity of the neutron star. Under development by an international Consortium led by the Institute of High Energy Physics of the Chinese Academy of Sciences, the eXTP mission is expected to be launched in the mid 2020s.
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| 2. |
- Mongodi, Silvia, et al.
(författare)
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Quantitative Lung Ultrasound : Technical Aspects and Clinical Applications
- 2021
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Ingår i: Anesthesiology. - : LIPPINCOTT WILLIAMS & WILKINS. - 0003-3022 .- 1528-1175. ; 134:6, s. 949-965
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Forskningsöversikt (refereegranskat)abstract
- Lung ultrasound is increasingly used in emergency departments, medical wards, and critical care units-adult, pediatric, and neonatal. In vitro and in vivo studies show that the number and type of artifacts visualized change with lung density. This has led to the idea of a quantitative lung ultrasound approach, opening up new prospects for use not only as a diagnostic but also as a monitoring tool. Consequently, the multiple scoring systems proposed in the last few years have different technical approaches and specific clinical indications, adaptable for more or less time-dependent patients. However, multiple scoring systems may generate confusion among physicians aiming at introducing lung ultrasound in their clinical practice. This review describes the various lung ultrasound scoring systems and aims to clarify their use in different settings, focusing on technical aspects, validation with reference techniques, and clinical applications.
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| 3. |
- Doroshenko, Victor, et al.
(författare)
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Luminosity dependence of the cyclotron line and evidence for the accretion regime transition in V 0332+53
- 2017
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Ingår i: Monthly notices of the Royal Astronomical Society. - : Oxford University Press. - 0035-8711 .- 1365-2966. ; 466:2, s. 2143-2150
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Tidskriftsartikel (refereegranskat)abstract
- We report on the analysis of NuSTAR observations of the Be-transient X-ray pulsar V 0332+ 53 during the giant outburst in 2015 and another minor outburst in 2016. We confirm the cyclotronline energy-luminosity correlation previously reported in the source and the line energy decrease during the giant outburst. Based on 2016 observations, we find that a year later the line energy has increased again essentially reaching the pre-outburst values. We discuss this behaviour and conclude that it is likely caused by a change of the emission region geometry rather than previously suggested accretion-induced decay of the neutron stars magnetic field. At lower luminosities, we find for the first time a hint of departure from the anticorrelation of line energy with flux, which we interpret as a transition from super-to sub-critical accretion associated with the disappearance of the accretion column. Finally, we confirm and briefly discuss the orbital modulation observed in the outburst light curve of the source.
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| 4. |
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| 5. |
- Santangelo, Gloria, et al.
(författare)
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Role of cardiac and lung ultrasound in the COVID-19 era
- 2023
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Ingår i: Minerva cardiology and angiology. - : Edizioni Minerva Medica. - 2724-5772. ; 71:4, s. 387-401
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Tidskriftsartikel (refereegranskat)abstract
- INTRODUCTION: The primary diagnostic method of Coronavirus disease 2019 is reverse transcription polymerase chain reaction of the nucleic acid of severe acute respiratory syndrome coronavirus 2 in nasopharyngeal swabs. There is growing evidence regarding the 2019 coronavirus disease imaging results on chest X-rays and computed tomography but the accessibility to standard diagnostic methods may be limited during the pandemic.EVIDENCE ACQUISITION: Databases used for the search were MEDLINE (PubMed), Scopus Search, and Cochrane Library. The research took into consideration studies published in English until March 2022 and was conducted using the following research query: ((((sars cov [MeSH Terms])) OR (COVID-19)) OR (Sars-Cov2)) OR (Coronavirus)) AND (((((2d echocardiography [MeSH Terms]) OR (doppler ultrasound imaging [MeSH Terms]))) OR (echography [MeSH Terms])) OR (LUS)) OR ("LUNG ULTRASOUND")).EVIDENCE SYNTHESIS: Pulmonary and cardiac ultrasound are cost-effective, widely available, and provide information that can influence management.CONCLUSIONS: Point-of-care ultrasonography is a method that can provide relevant clinical and therapeutic information in patients with COVID-19 where other diagnostic methods may not be easily accessible.
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| 6. |
- Soffitta, Paolo, et al.
(författare)
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A polarized view of the hot and violent universe
- 2021
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Ingår i: Experimental astronomy. - : Springer Nature. - 0922-6435 .- 1572-9508. ; 51:3, s. 1109-1141
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Tidskriftsartikel (refereegranskat)abstract
- X-ray polarimetry has long been considered the 'holy grail' of X-ray astronomy. Fortunately, after a silence of more than 40 years, the field is now rejuvenating. In fact, an X-ray polarimeter onboard a Cube-sat nano-satellite has been recently successfully operated. IXPE, the Imaging X-ray Polarimetry Explorer, will be launched in 2021 while eXTP, containing a larger version of IXPE, is expected to be launched in 2027. Although at present it is difficult to predict the discoveries that, given their exploratory nature, IXPE and eXTP will obtain, the path for a follow-up mission can already be envisaged. In this paper we describe the scientific goals of such a follow-up mission, and present a medium-size mission profile that can accomplish this task.
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| 7. |
- Soffitta, Paolo, et al.
(författare)
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XIPE : the X-ray imaging polarimetry explorer
- 2013
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Ingår i: Experimental astronomy. - : Springer Science and Business Media LLC. - 0922-6435 .- 1572-9508. ; 36:3, s. 523-567
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Tidskriftsartikel (refereegranskat)abstract
- X-ray polarimetry, sometimes alone, and sometimes coupled to spectral and temporal variability measurements and to imaging, allows a wealth of physical phenomena in astrophysics to be studied. X-ray polarimetry investigates the acceleration process, for example, including those typical of magnetic reconnection in solar flares, but also emission in the strong magnetic fields of neutron stars and white dwarfs. It detects scattering in asymmetric structures such as accretion disks and columns, and in the so-called molecular torus and ionization cones. In addition, it allows fundamental physics in regimes of gravity and of magnetic field intensity not accessible to experiments on the Earth to be probed. Finally, models that describe fundamental interactions (e.g. quantum gravity and the extension of the Standard Model) can be tested. We describe in this paper the X-ray Imaging Polarimetry Explorer (XIPE), proposed in June 2012 to the first ESA call for a small mission with a launch in 2017. The proposal was, unfortunately, not selected. To be compliant with this schedule, we designed the payload mostly with existing items. The XIPE proposal takes advantage of the completed phase A of POLARIX for an ASI small mission program that was cancelled, but is different in many aspects: the detectors, the presence of a solar flare polarimeter and photometer and the use of a light platform derived by a mass production for a cluster of satellites. XIPE is composed of two out of the three existing JET-X telescopes with two Gas Pixel Detectors (GPD) filled with a He-DME mixture at their focus. Two additional GPDs filled with a 3-bar Ar-DME mixture always face the Sun to detect polarization from solar flares. The Minimum Detectable Polarization of a 1 mCrab source reaches 14 % in the 2-10 keV band in 10(5) s for pointed observations, and 0.6 % for an X10 class solar flare in the 15-35 keV energy band. The imaging capability is 24 arcsec Half Energy Width (HEW) in a Field of View of 14.7 arcmin x 14.7 arcmin. The spectral resolution is 20 % at 6 keV and the time resolution is 8 mu s. The imaging capabilities of the JET-X optics and of the GPD have been demonstrated by a recent calibration campaign at PANTER X-ray test facility of the Max-Planck-Institut fur extraterrestrische Physik (MPE, Germany). XIPE takes advantage of a low-earth equatorial orbit with Malindi as down-link station and of a Mission Operation Center (MOC) at INPE (Brazil). The data policy is organized with a Core Program that comprises three months of Science Verification Phase and 25 % of net observing time in the following 2 years. A competitive Guest Observer program covers the remaining 75 % of the net observing time.
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| 8. |
- Spinelli, Angela, et al.
(författare)
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Prevalence of Severe Obesity among Primary School Children in 21 European Countries
- 2019
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Ingår i: Obesity Facts. - : S. Karger. - 1662-4025 .- 1662-4033. ; 12:2, s. 244-258
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The World Health Organization (WHO) European Childhood Obesity Surveillance Initiative (COSI) was established more than 10 years ago to estimate prevalence and monitor changes in overweight and obesity in children aged 6-9 years. Since then, there have been five rounds of data collection in more than 40 countries involving more than half a million children. To date, no comparative studies with data on severe childhood obesity from European countries have been published.OBJECTIVES: The aim of this work was to present the prevalence of severe obesity in school-aged children from 21 countries participating in COSI.METHOD: The data are from cross-sectional studies in 21 European WHO member states that took part in the first three COSI rounds of data collection (2007/2008, 2009/2010, 2012/2013). School-aged children were measured using standardized instruments and methodology. Children were classified as severely obese using the definitions provided by WHO and the International Obesity Task Force (IOTF). Analyses overtime, by child's age and mother's educational level, were performed in a select group of countries.RESULTS: A total of 636,933 children were included in the analysis (323,648 boys and 313,285 girls). The prevalence of severe obesity varied greatly among countries, with higher values in Southern Europe. According to the WHO definition, severe obesity ranged from 1.0% in Swedish and Moldovan children (95% CI 0.7-1.3 and 0.7-1.5, respectively) to 5.5% (95% CI 4.9-6.1) in Maltese children. The prevalence was generally higher among boys compared to girls. The IOTF cut-offs lead to lower estimates, but confirm the differences among countries, and were more similar for both boys and girls. In many countries 1 in 4 obese children were severely obese. Applying the estimates of prevalence based on the WHO definition to the whole population of children aged 6-9 years in each country, around 398,000 children would be expected to be severely obese in the 21 European countries. The trend between 2007 and 2013 and the analysis by child's age did not show a clear pattern. Severe obesity was more common among children whose mother's educational level was lower.CONCLUSIONS: Severe obesity is a serious public health issue which affects a large number of children in Europe. Because of the impact on educational, health, social care, and economic systems, obesity needs to be addressed via a range of approaches from early prevention of overweight and obesity to treatment of those who need it.
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| 9. |
- Tsygankov, Sergey S., et al.
(författare)
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The unusual behavior of the young X-ray pulsar SXP 1062 during the 2019 outburst
- 2020
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Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 637
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Tidskriftsartikel (refereegranskat)abstract
- We present the results of the first dedicated observation of the young X-ray pulsar SXP 1062 in the broad X-ray energy band obtained during its 2019 outburst with the NuSTAR and XMM-Newton observatories. The analysis of the pulse-phase averaged and phase-resolved spectra in the energy band from 0.5 to 70 keV did not reveal any evidence for the presence of a cyclotron line. The spin period of the pulsar was found to have decreased to 979.48 +/- 0.06 s implying a similar to 10% reduction compared to the last measured period during the monitoring campaign conducted about five years ago, and is puzzling considering that the system apparently has not shown major outbursts ever since. The switch of the pulsar to the spin-up regime supports the common assumption that torques acting on the accreting neutron star are nearly balanced and thus SXP 1062 likely also spins with a period close to the equilibrium value for this system. The current monitoring of the source also revealed a sharp drop in its soft X-ray flux right after the outburst, which is in drastic contrast to the behavior during the previous outburst when the pulsar remained observable for years with only a minor flux decrease after the end of the outburst. This unexpected off state of the source lasted for at most 20 days after which SXP 1062 returned to the level observed during previous campaigns. We discuss this and other findings in context of the modern models of accretion onto strongly magnetized neutron stars.
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| 10. |
- Zane, Silvia, et al.
(författare)
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The on-board calibration system of the X-ray Imaging Polarimetry Explorer (XIPE)
- 2016
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Ingår i: SPACE TELESCOPES AND INSTRUMENTATION 2016. - : SPIE - International Society for Optical Engineering. - 9781510601895
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Konferensbidrag (refereegranskat)abstract
- The calibration system for XIPE is aimed at providing a way to check and correct possible variations of performance of the Gas Pixel Detector during the three years of operation in orbit (plus two years of possible extended operation), while facilitating the observation of the celestial sources. This will be performed by using a filter wheel with a large heritage having a set of positions for the calibration and the observation systems. In particular, it will allow for correcting possible gain variation, for measuring the modulation factor using a polarized source, for removing non interesting bright sources in the field of view and for observing very bright celestial sources. The on-board calibration system is composed of three filter wheels, one for each detector and it is expected to operate for a small number of times during the year. Moreover, since it operates once at a time, within the observation mode, it allows for simultaneous calibration and acquisition from celestial sources on different detectors. In this paper we present the scope and the requirements of the on-board calibration system, its design, and a description of its possible use in space.
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