Critical Aspects of Material Selection in the Packaging and Transporting of Returned Extraterrestrial Samples.

In the framework of the EU-funded EURO-CARES project, aimed at determining the actions to develop a European facility for curation of extraterrestrial samples returned by space missions, we identified the requirements (mainly in terms of materials selection) of the transportation containment facility which should contain the Sample Return Capsule (SRC), which in turn contains the extraterrestrial material returned to Earth. Transportation box design for restricted (i.e., possibly related to biological life) and unrestricted samples is different. Packaging and transport of restricted samples must guarantee the samples' preservation from the terrestrial environment and the safety of people performing these operations and, hence, must be done according to World Health Organization (WHO) rules. In the case of unrestricted samples, the only requirement is sample preservation. We propose a triple packaging as follows: (1) primary receptacle; (2) secondary package (plastic material), optional for unrestricted samples; (3) rigid, cushioned outer layer. Only for restricted samples, an additional layer is proposed, that is, the overpack. The primary receptacle coincides with the SRC. The plastic material of the secondary package must have a low outgassing rate (i.e., <10-7 torr/s) and preferably low permeability and cost. Teflon and Neoflon would be the best choices. The outer package must be rigid and resistant to breakage, and our trade-off analysis identified stainless steel and aluminum alloys as best options. The outer should be filled with an inert atmosphere to inhibit oxidation within the sample in case of leak: argon is more inert than nitrogen, but the latter is easily available. The overpack allows the box environment control (e.g., real-time contamination monitoring); ISO containers could be used to this end. Contamination of the environment inside the box can be monitored by different instruments, which should be selected on the basis of mission requirements. There are no mass limitations for box transport by ground or ship, but these solutions imply a long journey duration. Any aircraft might be used for transporting unrestricted samples. Only cargo aircraft may be used for transporting restricted samples, unless the total sample mass is lower than 50 g (WHO guidelines).

Influence of respiratory and inflammatory parameters preceding intubation on survival of patients with COVID-19 ARDS- A single centre retrospective analysis.

It remains unclear if intubation and ventilation earlier in the disease course confers a survival advantage in acute respiratory distress syndrome. Our objective was to determine whether patients with COVID-19 who died following mechanical ventilation were more advanced in their disease compared to survivors. Forty-seven patients admitted directly to our centre received ventilation, of who 26 (57%) patients died. The rate of fall in SpO2:FiO2 ratio (p = 0.478) and increasing respiratory rate (p = 0.948) prior to IMV were similar between survivors and non-survivors. Our data support a trial of continuous positive airway pressure prior to IMV in patients with moderate-to-severe COVID-19 ARDS.

Localized aliphatic organic material on the surface of Ceres.

Organic compounds occur in some chondritic meteorites, and their signatures on solar system bodies have been sought for decades. Spectral signatures of organics have not been unambiguously identified on the surfaces of asteroids, whereas they have been detected on cometary nuclei. Data returned by the Visible and InfraRed Mapping Spectrometer on board the Dawn spacecraft show a clear detection of an organic absorption feature at 3.4 micrometers on dwarf planet Ceres. This signature is characteristic of aliphatic organic matter and is mainly localized on a broad region of ~1000 square kilometers close to the ~50-kilometer Ernutet crater. The combined presence on Ceres of ammonia-bearing hydrated minerals, water ice, carbonates, salts, and organic material indicates a very complex chemical environment, suggesting favorable environments to prebiotic chemistry.

Distribution of phyllosilicates on the surface of Ceres.

The dwarf planet Ceres is known to host phyllosilicate minerals at its surface, but their distribution and origin have not previously been determined. We used the spectrometer onboard the Dawn spacecraft to map their spatial distribution on the basis of diagnostic absorption features in the visible and near-infrared spectral range (0.25 to 5.0 micrometers). We found that magnesium- and ammonium-bearing minerals are ubiquitous across the surface. Variations in the strength of the absorption features are spatially correlated and indicate considerable variability in the relative abundance of the phyllosilicates, although their composition is fairly uniform. These data, along with the distinctive spectral properties of Ceres relative to other asteroids and carbonaceous meteorites, indicate that the phyllosilicates were formed endogenously by a globally widespread and extensive alteration process.

Bright carbonate deposits as evidence of aqueous alteration on (1) Ceres.

The typically dark surface of the dwarf planet Ceres is punctuated by areas of much higher albedo, most prominently in the Occator crater. These small bright areas have been tentatively interpreted as containing a large amount of hydrated magnesium sulfate, in contrast to the average surface, which is a mixture of low-albedo materials and magnesium phyllosilicates, ammoniated phyllosilicates and carbonates. Here we report high spatial and spectral resolution near-infrared observations of the bright areas in the Occator crater on Ceres. Spectra of these bright areas are consistent with a large amount of sodium carbonate, constituting the most concentrated known extraterrestrial occurrence of carbonate on kilometre-wide scales in the Solar System. The carbonates are mixed with a dark component and small amounts of phyllosilicates, as well as ammonium carbonate or ammonium chloride. Some of these compounds have also been detected in the plume of Saturn's sixth-largest moon Enceladus. The compounds are endogenous and we propose that they are the solid residue of crystallization of brines and entrained altered solids that reached the surface from below. The heat source may have been transient (triggered by impact heating). Alternatively, internal temperatures may be above the eutectic temperature of subsurface brines, in which case fluids may exist at depth on Ceres today.

Exposed water ice on the nucleus of comet 67P/Churyumov-Gerasimenko.

Although water vapour is the main species observed in the coma of comet 67P/Churyumov-Gerasimenko and water is the major constituent of cometary nuclei, limited evidence for exposed water-ice regions on the surface of the nucleus has been found so far. The absence of large regions of exposed water ice seems a common finding on the surfaces of many of the comets observed so far. The nucleus of 67P/Churyumov-Gerasimenko appears to be fairly uniformly coated with dark, dehydrated, refractory and organic-rich material. Here we report the identification at infrared wavelengths of water ice on two debris falls in the Imhotep region of the nucleus. The ice has been exposed on the walls of elevated structures and at the base of the walls. A quantitative derivation of the abundance of ice in these regions indicates the presence of millimetre-sized pure water-ice grains, considerably larger than in all previous observations. Although micrometre-sized water-ice grains are the usual result of vapour recondensation in ice-free layers, the occurrence of millimetre-sized grains of pure ice as observed in the Imhotep debris falls is best explained by grain growth by vapour diffusion in ice-rich layers, or by sintering. As a consequence of these processes, the nucleus can develop an extended and complex coating in which the outer dehydrated crust is superimposed on layers enriched in water ice. The stratigraphy observed on 67P/Churyumov-Gerasimenko is therefore the result of evolutionary processes affecting the uppermost metres of the nucleus and does not necessarily require a global layering to have occurred at the time of the comet's formation.

Ammoniated phyllosilicates with a likely outer Solar System origin on (1) Ceres.

Studies of the dwarf planet (1) Ceres using ground-based and orbiting telescopes have concluded that its closest meteoritic analogues are the volatile-rich CI and CM carbonaceous chondrites. Water in clay minerals, ammoniated phyllosilicates, or a mixture of Mg(OH)2 (brucite), Mg2CO3 and iron-rich serpentine have all been proposed to exist on the surface. In particular, brucite has been suggested from analysis of the mid-infrared spectrum of Ceres. But the lack of spectral data across telluric absorption bands in the wavelength region 2.5 to 2.9 micrometres--where the OH stretching vibration and the H2O bending overtone are found--has precluded definitive identifications. In addition, water vapour around Ceres has recently been reported, possibly originating from localized sources. Here we report spectra of Ceres from 0.4 to 5 micrometres acquired at distances from ~82,000 to 4,300 kilometres from the surface. Our measurements indicate widespread ammoniated phyllosilicates across the surface, but no detectable water ice. Ammonia, accreted either as organic matter or as ice, may have reacted with phyllosilicates on Ceres during differentiation. This suggests that material from the outer Solar System was incorporated into Ceres, either during its formation at great heliocentric distance or by incorporation of material transported into the main asteroid belt.

Olivine in an unexpected location on Vesta's surface.

Olivine is a major component of the mantle of differentiated bodies, including Earth. Howardite, eucrite and diogenite (HED) meteorites represent regolith, basaltic-crust, lower-crust and possibly ultramafic-mantle samples of asteroid Vesta, which is the lone surviving, large, differentiated, basaltic rocky protoplanet in the Solar System. Only a few of these meteorites, the orthopyroxene-rich diogenites, contain olivine, typically with a concentration of less than 25 per cent by volume. Olivine was tentatively identified on Vesta, on the basis of spectral and colour data, but other observations did not confirm its presence. Here we report that olivine is indeed present locally on Vesta's surface but that, unexpectedly, it has not been found within the deep, south-pole basins, which are thought to be excavated mantle rocks. Instead, it occurs as near-surface materials in the northern hemisphere. Unlike the meteorites, the olivine-rich (more than 50 per cent by volume) material is not associated with diogenite but seems to be mixed with howardite, the most common surface material. Olivine is exposed in crater walls and in ejecta scattered diffusely over a broad area. The size of the olivine exposures and the absence of associated diogenite favour a mantle source, but the exposures are located far from the deep impact basins. The amount and distribution of observed olivine-rich material suggest a complex evolutionary history for Vesta.

Dark material on Vesta from the infall of carbonaceous volatile-rich material.

Localized dark and bright materials, often with extremely different albedos, were recently found on Vesta's surface. The range of albedos is among the largest observed on Solar System rocky bodies. These dark materials, often associated with craters, appear in ejecta and crater walls, and their pyroxene absorption strengths are correlated with material brightness. It was tentatively suggested that the dark material on Vesta could be either exogenic, from carbon-rich, low-velocity impactors, or endogenic, from freshly exposed mafic material or impact melt, created or exposed by impacts. Here we report Vesta spectra and images and use them to derive and interpret the properties of the 'pure' dark and bright materials. We argue that the dark material is mainly from infall of hydrated carbonaceous material (like that found in a major class of meteorites and some comet surfaces), whereas the bright material is the uncontaminated indigenous Vesta basaltic soil. Dark material from low-albedo impactors is diffused over time through the Vestan regolith by impact mixing, creating broader, diffuse darker regions and finally Vesta's background surface material. This is consistent with howardite-eucrite-diogenite meteorites coming from Vesta.

Auditory-evoked potentials in general anesthesia monitoring: baseline study of availability in relation to hearing function in awake status.

BACKGROUND: It has been confirmed that middle latency auditory-evoked potentials are good indicators of the hypnotic level in patients undergoing general anesthesia. The focal point for the evocation of auditory-evoked potentials is the presence of a serviceable hearing function. The aim of the study was to evaluate the limit of hearing loss above which the test could not be applied. METHODS: To determine the limit of applicability of the technique, 100 subjects were studied. Twenty of them were normally hearing and 80 were affected by sensorineural hearing loss of various degrees. Each subject was submitted to pure tone audiometry, to determine hearing threshold, and then, in awake status, to auditory-evoked potentials recording using acoustic stimuli of 85 dB HL. RESULTS: All the 20 normally hearing subjects showed a reliable auditory-evoked potentials. Among the 80 subjects affected by hearing loss, only five had no potentials. These five subjects presented a pure tone audiometry threshold greater than 85 dB HL. CONCLUSION: The study demonstrated that middle latency auditory-evoked potentials recorded using an A-Line (software version 1.4) AEP monitor (Danmeter, Odense, Denmark) can be carried out even in presence of hearing loss if the pure tone threshold is less than 85 dB HL.

Longitudinal survey of anticardiolipin antibodies in systemic lupus erythematosus. Relationships with clinical manifestations and disease activity in an Italian series.

One hundred and two patients suffering from systemic lupus erythematosus were observed over 5-140 months. IgG and IgM anticardiolipin antibodies (aCL) were searched for by ELISA in 448 serum samples, and were found in 88 (86.3%) patients on at least one occasion. Changes of aCL levels and isotypes were recorded in most patients. In patients with medium (20-80 U. GPL and/or MPL) and high (> 80 U. GPL and/or MPL) aCL levels associations with thrombosis, neurological manifestations, cerebrovascular disease, prolonged aPTT, and thrombocytopenia were found. A highly significant statistical association was found between IgG aCL and the occurrence of active disease (p < 0.0001).