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.

The diurnal cycle of water ice on comet 67P/Churyumov-Gerasimenko.

Observations of cometary nuclei have revealed a very limited amount of surface water ice, which is insufficient to explain the observed water outgassing. This was clearly demonstrated on comet 9P/Tempel 1, where the dust jets (driven by volatiles) were only partially correlated with the exposed ice regions. The observations of 67P/Churyumov-Gerasimenko have revealed that activity has a diurnal variation in intensity arising from changing insolation conditions. It was previously concluded that water vapour was generated in ice-rich subsurface layers with a transport mechanism linked to solar illumination, but that has not hitherto been observed. Periodic condensations of water vapour very close to, or on, the surface were suggested to explain short-lived outbursts seen near sunrise on comet 9P/Tempel 1. Here we report observations of water ice on the surface of comet 67P/Churyumov-Gerasimenko, appearing and disappearing in a cyclic pattern that follows local illumination conditions, providing a source of localized activity. This water cycle appears to be an important process in the evolution of the comet, leading to cyclical modification of the relative abundance of water ice on its surface.

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.

Constraining the Rosalind Franklin Rover/Ma_MISS Instrument Capability in the Detection of Organics.

The Mars Multispectral Imager for Subsurface Studies (Ma_MISS) instrument is a miniaturized visible and near-infrared spectrometer that is integrated into the drilling system of the ESA Rosalind Franklin rover, which is devoted to subsurface exploration on Mars. Ma_MISS will acquire spectral data on the Martian subsurface from excavated borehole walls. The spectral data collected by Ma_MISS on unexposed rocks will be crucial for determination of the composition of subsurface rocks and optical and physical properties of materials (i.e., grain size). Ma_MISS will further contribute to a reconstruction of the stratigraphic column and acquire data on subsurface geological processes. Ma_MISS data may also inform with regard to the presence of potential biomarkers in the subsurface, given the presence of organic matter that may affect some spectral parameters. In this framework, we performed a wide range of measurements using the laboratory model of the Ma_MISS to investigate mineral/organic mixtures in different proportions. We prepared mixtures by combining kaolinite and nontronite with glycine, asphaltite, polyoxymethylene, and benzoic acid. These organic compounds show different spectral characteristics in the visible and near-infrared; therefore their presence can be detected by the Ma_MISS instrument. Our results indicate that the Ma_MISS instrument can detect organic material down to abundances of around 1 wt %. In particular, the data collected on low-concentration mixtures show that, by analyzing sediments with a grain size smaller than the Ma_MISS spatial resolution, the instrument can still discern those points where organic matter is present from points with exclusive mineral composition. The results also show that a collection of multiple contiguous measurements on a hypothetical borehole wall could help indicate the presence of organic matter in clay-rich soils if present.

The pre-launch on-ground characterization of Ma_MISS spectrometer for ExoMars-Rosalind Franklin Rover mission. II. Radiometric calibration.

The Ma_MISS miniaturized spectrometer is integrated within the Drilling System of the ExoMars Rosalind Franklin Rover for Mars exploration. Here we focus on the on ground calibration campaign to obtain radiometric and linearity calibrations of the Ma_MISS instrument, while the first paper dealt with the spectral calibration [De Angelis et al., Rev. Sci. Instrum. 93, 123704 (2022)]. The experimental setup used to carry out radiometric calibration is described, as are the methods used for data processing and key parameter retrieval. In particular, the Spectrometer Transfer Function (Responsivity), Signal-to-Noise Ratio, and detector linearity are determined. In a third paper [De Sanctis et al., Planet. Sci. J. 3, 142 (2022)], validation of the Ma_MISS calibration results through spectral measurements performed on rock and synthetic targets during the radiometric calibration campaign is described.

The pre-launch on-ground characterization of Mars Multispectral Imager for Subsurface Studies (Ma_MISS) spectrometer for ExoMars rover mission: Spectral calibration.

The Ma_MISS spectrometer is integrated within the drilling system of the Rosalind Franklin ExoMars rover. This paper reports the on-ground calibration campaign performed on the spectrometer. Here, we focus on the spectral calibration of the instrument. The experimental setup used to carry out calibration is described, and the methods used for data processing and key parameters retrieval are explained. In particular, the spectral parameters such as (i) pixel central wavelengths, (ii) spectral response function, (iii) spectral resolution, (iv) sampling, and (v) range are determined. In a follow-up paper, the linearity and radiometric calibrations are described, while in De Sanctis et al. [Planet. Sci. J. 3, 142 (2022)], the validation of spectral measurements performed on synthetic and natural rock targets is presented.

Unusual case of enlarged choroidal vessels in neurofibromatosis type 1 observed with near-infrared reflectance and spectral domain optical coherence tomography.

ABSTRACT: The cardinal diagnostic signs of neurofibromatosis type 1 (NF1) are Lisch nodules of the iris and optic pathway gliomas. Retinal mi-crovascular alterations have been described but with uncertain signi-ficance. Choroidal nodules, detectable with near-infrared reflectance (NIR) imaging, are present in most cases and have been proposed as a new diagnostic criterion. Recently, a study reported the presence of unusual dilated choroidal vessels, visible through NIR examination. We report a case of a 65-year-old patient with NF1. Best-corrected visual acuity was 20/20 with a refractive error of +2.75 diopters in both eyes. Anterior segment examination revealed Lisch nodules in both eyes. At NIR imaging the patient presented typical choroidal alterations in both eyes. No retinal vessel anomalies were detected. The patient presented enlarged choroidal vessels in the left eye, first detected by NIR and then analyzed through enhanced depth imaging spectral domain optical coherence tomography (EDI-SDOCT). These vessels extended from the choroidal-scleral junction to the outer border of the retinal pigment epithelium/Bruch's layer. The choriocapillaris layer was absent above the dilated vessels. The presence of enlarged choroidal vessels may be considered as a novel distinctive ophthalmologic aspect of NF1, but further studies are necessary.

Design, development, and testing of an environmental P-T cell for infrared spectroscopy measurements.

Water absorption bands due to superficially adsorbed molecules often dominate the near-infrared spectra of particulate minerals and rocks, when measured in the laboratory in the reflectance mode. In order to remove this, the spectral effect is thus necessary to acquire spectra of samples in vacuum and at higher temperatures. With the aim to accomplish this task, we developed an environmental cell to perform infrared spectroscopic measurements at controlled pressure-temperature conditions. Currently the cell allows one to measure reflectance spectra in the temperature range from room values up to 300 °C (573 K), in the pressure range of 103-10-6 mbar. The acquisition of spectra continuously in two distinct phases, namely, during a preliminary pumping stage (at room T) and subsequently during a heating stage (in vacuum), permits to highlight and characterize separately the effect of pressure and temperature on infrared spectra.

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.

[Reappearance of alopecia areata in a coeliac patient during an unintentional challenge with gluten]. / Ricomparsa di alopecia areata in una paziente celiaca durante un challenge involontario con glutine.

A patient with coeliac disease presenting alopecia areas as the only symptom is described. Alopecia disappeared completely after a few months of strict gluten free diet and reappeared after an unintentional prolonged introduction of gluten. After a severe gluten free diet, a new and persistent hair growth in the alopecia areas was observed. The possibility a direct relationship in some cases, between coeliac disease and alopecia areata is confirmed.

[Gastroesophageal reflux in children]. / Reflusso gastroesofageo nel bambino.

Gastroesophageal reflux (GER) is the return of gastric content from stomach to esophagus. The above phenomenon takes place for sphincter insufficiency of lower esophagus. RGE causes are various. RGE disease must be suspected when a children or an infant shows symptoms such as regurgitation and/or after lunch vomit, poor weight growth, anorexia, pyrosis, etc. In the last years dietetic and pharmacologic therapy have brought an improvement and/or a remission of the GER disease.

[Celiac disease and autoimmunity: state of the art]. / Malattia celiaca ed autoimmunità: stato attuale dell'arte.

Coeliac disease is probably an immunologic disease of the small intestine which is caused by a gluten intake as promoting agent in genetically predisposed persons. Many authors described this autoimmune assumption: most of coeliac patients carry the HLA type, HLA-DQ (alpha 1 x 0501, beta 1 x 0201) etherodimer; it was found a correlation between disease specific antibodies antigliadin (AGA), antireticulin (ARA) and antiendomysium (AEA). Therefore an increase of autoantibodies and lymphocytes in the blood of coeliacs suggest the autoimmune nature of coeliac disease.

[Chronic intestinal inflammatory diseases]. / Malattie infiammatorie croniche intestinali.

In the last years the research on the etiopathogenesis of the inflammatory bowel disease (IBD) is focused around immunological aspects. Many authors consider that the intestinal inflammation is due to an inappropriate immunological response to normally present antigens in the gut. Two aspects must to be considered between IBD: Crohn's disease and ulcerative colitis. IBD's diagnosis is based on the symptomatology, (cramps, liquid feces with mucus and blood, anorexia and weight loss), hemato-clinical tests (ESR, PCR, blood platelet, mucoprotein, sideremia) and radiological tests (tenuis Rx, abdominal echography, fibro endoscophy and scintigraphy). Principal aim of the therapy is the clinical remission. Following the remission starts a maintenance protocol. Parenteral nutrition is used in paediatric and adolescent age. Diets have been used to provide a convenient nutritious contribution with growth improvement and partial remission of activity index of the disease. Pharmacology therapy represents a valid instrument to obtain the remission. Colectomy is performed on unsuccessful medical therapy. Early studies on IBD's pathogenesis bring to the use of biological therapies that show beneficial effects on the disease.

Value of antigliadin antibodies (AGA) in latent coeliac disease (CD).

BACKGROUND: The term latent coeliac disease (CD) is applied to patients who were previously shown to have a normal jejunal mucosa on a free diet. The aim of this study was to determine whether a high AGA value in the serum of patients with coeliac symptoms can also be regarded by itself, without typical mucosal atrophy, as a marker of latent CD, as some authors suggest in relatives of celiac patients. METHODS: We observed 31 patients with suspected CD and pathological values of serum IgA ang IgG AGA. In all we performed intestinal biopsy, assayed antiendomisium antibodies (AEA) in serum, AGA IgA, IgG, and IgM in duodenal jejunal fluid and in some of the lymphocytcs CD3+ gamma/delta+ in the lamina propria of the intestinal mucosa. RESULTS: In this study only pathological values of serum AGA without mucosa atrophy don't seem to be markers of latent CD, but an aspecific allergic response. CONCLUSIONS: As shown by other authors serum AEA, intestinal fluid AGA IgM and lamina propria lymphocytes CD3+ gamma/delta+ seem markers of latent CD.