The High Energy Modular Ensemble of Satellites (HERMES) project is aimed to realize a modular X/gamma-ray monitor for transient events, to be placed on-board of a nano-satellite bus (e.g. CubeSat). ...This expandable platform will achieve a significant impact on Gamma Ray Burst (GRB) science and on the detection of Gravitational Wave (GW) electromagnetic counterparts: the recent LIGO/VIRGO discoveries demonstrated that the high-energy transient sky is still a field of extreme interest. The very complex temporal variability of GRBs (experimentally verified up to the millisecond scale) combined with the spatial and temporal coincidence between GWs and their electromagnetic counterparts suggest that upcoming instruments require sub-microsecond time resolution combined with a transient localization accuracy lower than a degree. The current phase of the ongoing HERMES project is focused on the realization of a technological pathfinder with a small network (3 units) of nano-satellites to be launched in mid 2020. We will show the potential and prospects for short and medium-term development of the project, demonstrating the disrupting possibilities for scientific investigations provided by the innovative concept of a new “modular astronomy” with nano-satellites (e.g. low developing costs, very short realization time). Finally, we will illustrate the characteristics of the HERMES Technological Pathfinder project, demonstrating how the scientific goals discussed are actually already reachable with the first nano-satellites of this constellation. The detector architecture will be described in detail, showing that the new generation of scintillators (e.g. GAGG:Ce) coupled with very performing Silicon Drift Detectors (SDD) and low noise Front-End-Electronics (FEE) are able to extend down to few keV the sensitivity band of the detector. The technical solutions for FEE, Back-End-Electronics (BEE) and Data Handling will be also described.
Antibiotics for bacteriuria and urinary tract infection are commonly prescribed during pregnancy to avoid adverse pregnancy outcomes. The aim of this study was to evaluate the association between ...significant bacteriuria in pregnancy and any of the four pregnancy outcomes: preterm delivery; low birth weight; small for gestational age; and preterm labour.
Systematic review with meta-analysis of observational studies. We searched PubMed, EMBASE, the Cochrane CENTRAL library, and Web of Science for observational studies published before 1 March 2022. The risk of bias was assessed using the Newcastle-Ottawa scale. Study identification, data extraction and risk-of-bias assessment was performed by two independent authors. We combined the included studies in meta-analyses and expressed results as ORs with 95% CIs (Prospero CRD42016053485).
We identified 58 studies involving 421 657 women. The quality of the studies was mainly poor or fair. The pooled, unadjusted OR for the association between any significant bacteriuria and: (i) preterm delivery was 1.62 (95% CI: 1.30-2.01; 27 studies; I2 = 61%); (ii) low birth weight was 1.50 (95% CI: 1.30-1.72; 47 studies; I2 = 74%); (iii) preterm labour was 2.29 (95% CI: 1.53-3.43; 3 studies; I2 = 0%); and (iv) small for gestational age was 1.33 (95% CI: 0.88-2.02; 7 studies; I2 = 54%). Four studies provided an adjusted OR, but were too diverse to combine in meta-analysis.
This systematic review identified an association between significant bacteriuria in pregnancy and the three complications: preterm delivery; low birth weight; and preterm labour. However, the quality of the available evidence is insufficient to conclude whether this association is merely due to confounding factors. There is a lack of high-quality evidence to support active identification and treatment of bacteriuria in pregnancy.
Due to be launched in late 2021, the Imaging X-ray Polarimetry Explorer (IXPE) is a NASA Small Explorer mission designed to perform polarization measurements in the 2–8 keV band, complemented with ...imaging, spectroscopy and timing capabilities. At the heart of the focal plane is a set of three polarization-sensitive Gas Pixel Detectors (GPD), each based on a custom ASIC acting as a charge-collecting anode.
In this paper we shall review the design, manufacturing, and test of the IXPE focal-plane detectors, with particular emphasis on the connection between the science drivers, the performance metrics and the operational aspects. We shall present a thorough characterization of the GPDs in terms of effective noise, trigger efficiency, dead time, uniformity of response, and spectral and polarimetric performance. In addition, we shall discuss in detail a number of instrumental effects that are relevant for high-level science analysis—particularly as far as the response to unpolarized radiation and the stability in time are concerned.
Abstract
The eXTP (enhanced X-ray Timing and Polarimetry) mission is a major project of the Chinese Academy of Sciences (CAS) and China National Space Administration (CNSA) currently performing a ...phase B study and proposed for a launch in 2027. The eXTP scientific payload envisages a suite of instruments offering unprecedented simultaneous wide-band X-ray timing and polarimetry sensitivity. A large European consortium is contributing to the eXTP study and it is expected to provide key hardware elements, including the Large Area Detector (LAD) composed of 40 modules for a total effective area of 3.0 m
2
at 6.0 keV. In this paper, we describe the preliminary study that led to the design solutions adopted for the most important thermo-mechanical drivers of the LAD Module, which have been elaborated and used for the demonstration of compliance to the system requirements at spacecraft level. We report in particular the mechanical design for the Module and its components, the thermal analysis for each range temperature of the worst cases (coldest case) with the evaluation of the thermoelastic deformation of a reduced module and the results of a campaign of static and dynamic finite element analysis of a simplified parametric model with an accurate mesh processing and the preliminary optimization of the critical components.
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