Solid deuterated water in space: detection constraints from laboratory experiments

The comparison between astronomical spectra and laboratory experiments is fundamental to spread light on the structure and composition of ices found in interstellar dense molecular clouds and in Solar system bodies. Water is among the most abundant solid-phase species observed in these environments, and several attempts have been made to investigate the presence of its solid-phase isotopologues. In particular, the detection of the O-D stretching mode band at 4.1 μm due to both D2O and HDO within icy grain mantles is still under debate, and no detection has been reported about the presence of these species within icy bodies in the Solar system yet. In the near future, an important contribution could derive from the data acquired in the O-D stretching mode spectral range by the sensitive instruments on board the James Webb Space Telescope. With this in mind, we performed several laboratory experiments to study the O-D stretching mode band in solid mixtures containing water and deuterated water deposited in the temperature range between 17 and 155 K, in order to simulate astrophysical relevant conditions. Furthermore, samples have been studied at various temperature and irradiated with energetic ions (200 keV H^+) in order to study the effects induced by both thermal and energetic processing. Our results provide some constraints on the detection of the 4.1 μm band in astronomical environments

Ion irradiation triggers the formation of the precursors of complex organics in space - The case of formaldehyde and acetaldehyde

Context. Cosmic rays and solar energetic particles induce changes in the composition of compounds frozen onto dust grains in the interstellar medium (ISM), in comets, and on the surfaces of atmosphere-less small bodies in the outer Solar System. This induces the destruction of pristine compounds and triggers the formation of various species, including the precursors of complex organics. Aims. We investigate the role of energetic ions in the formation of formaldehyde (H2CO) and acetaldehyde (CH3CHO), which are observed in the ISM and in comets, and which are thought to be the precursors of more complex compounds such as hexamethylenete-tramine (HMT), which is found in carbonaceous chondrites and in laboratory samples produced after the irradiation and warm-up of astrophysical ices. Methods. We performed ion irradiation of water, methanol, and ammonia mixtures at 14–18 K. We bombarded frozen films with 40–200 keV H+ that simulate solar energetic particles and low-energy cosmic rays. Samples were analysed by infrared transmission spectroscopy. Results. Among other molecules, we observe the formation of H2CO and CH3CHO, and we find that their abundance depends on the dose and on the stoichiometry of the mixtures. We find that the H2CO abundance reaches the highest value after a dose of 10 eV/16u and then it decreases as the dose increases. Conclusions. The data suggest that surfaces exposed to high doses are depleted in H2CO. This explains why the amount of HMT in organic residues and that formed after irradiation of ices depends on the dose deposited in the ice. Because the H2CO abundance decreases at doses higher than 10 eV/16u, a lower quantity of H2CO is available to form HMT during the subsequent warm-up. The H2CO abundances caused by ion bombardment are insufficient to explain the ISM abundances, but ion bombardment can account for the abundance of CH3CHO towards the ISM and comets

Infrared study on the thermal evolution of solid state formamide

Laboratory experiments have shown that the energetic processing, i.e. ion bombardment and UV photolysis, of interstellar grain mantles and cometary surfaces is efficient in the production of formamide. To explain its presence in the gas-phase in these astrophysical environments, a desorption mechanism has to be taken into account. In this work we show experimental results on the thermal evolution of formamide when deposited at 17 K as pure and in mixture with water or carbon monoxide. In these samples, we observed formamide desorption at 220 K. Moreover, we discuss its synthesis in a mixture containing molecular nitrogen, methane and water (N2:CH4:H2O) deposited at 17 K and bombarded with 200 keV H+. Heating the sample, we observed that the newly formed formamide remains trapped in the refractory residue produced after the ion bombardment up to 296 K. To analyse the samples we used Fourier transform-infrared spectroscopy (FT-IR) that allowed us to study the infrared spectra between the deposition and the complete desorption of formamide. Here we discuss the experimental results in view of their astrophysical relevance

Future space experiment platforms for astrobiology and astrochemistry research

Space experiments are a technically challenging but a scientifically important part of astrobiology and astrochemistry research. The International Space Station (ISS) is an excellent example of a highly successful and long-lasting research platform for experiments in space, that has provided a wealth of scientific data over the last two decades. However, future space platforms present new opportunities to conduct experiments with the potential to address key topics in astrobiology and astrochemistry. In this perspective, the European Space Agency (ESA) Topical Team Astrobiology and Astrochemistry (with feedback from the wider scientific community) identifies a number of key topics and summarizes the 2021 “ESA SciSpacE Science Community White Paper” for astrobiology and astrochemistry. We highlight recommendations for the development and implementation of future experiments, discuss types of in situ measurements, experimental parameters, exposure scenarios and orbits, and identify knowledge gaps and how to advance scientific utilization of future space-exposure platforms that are either currently under development or in an advanced planning stage. In addition to the ISS, these platforms include CubeSats and SmallSats, as well as larger platforms such as the Lunar Orbital Gateway. We also provide an outlook for in situ experiments on the Moon and Mars, and welcome new possibilities to support the search for exoplanets and potential biosignatures within and beyond our solar system

Double role of HMTA in ZnO nanorods grown by chemical bath deposition

ZnO nanorods (NRs) grown by chemical bath deposition (CBD) are among the most promising semiconducting nanostructures currently investigated for a variety of applications. Still, contrasting experimental results appear in the literature on the microscopic mechanisms leading to high aspect ratio and vertically aligned ZnO NRs. Here, we report on CBD of ZnO NRs using Zn nitrate salt and hexamethylenetetramine (HMTA), evidencing a double role of HMTA in the NRs growth mechanism. Beyond the well-established pH buffering activity, HMTA is shown to introduce a strong steric hindrance effect, biasing growth along the c-axis and ensuring the vertical arrangement. This twofold function of HMTA should be taken into account for avoiding detrimental phenomena such as merging or suppression of NRs, which occur at low HMTA concentration

Formation and Alteration of Complex Organics Induced by Energetic Processing

The frozen surface of small bodies in the outer Solar System are exposed to energetic charged particles that alter their chemical composition. Laboratory experiments allow to simulate the interaction between cosmic rays and solar particles with frozen surfaces, showing the formation of complex organic compounds. However, irradiation also determines the destruction of both simple and complex molecules. We here report about recent laboratory experiments to simulate the irradiation and heating of surfaces in the outer Solar System and the detection of complex organics. We also present experiments that will be held on the International Space Station (OREOCube and Exocube) and a new facility to study the alteration induced on such complex organics, as well as on prebiotic species and biosignatures

Comparing the use of ERA5 reanalysis dataset and ground-based agrometeorological data under different climates and topography in Italy

Study region: The study region is represented by seven irrigation districts distributed under different climate and topography conditions in Italy. Study focus: This study explores the reliability and consistency of the global ERA5 single levels and ERA5-Land reanalysis datasets in predicting the main agrometeorological estimates commonly used for crop water requirements calculation. In particular, the reanalysis data was compared, variable-by-variable (e.g., solar radiation, R-s; air temperature, T-air; relative humidity, RH; wind speed, u(10); reference evapotranspiration, ET0), with in situ agrometeorological obser-vations obtained from 66 automatic weather stations (2008-2020). In addition, the presence of a climate-dependency on their accuracy was assessed at the different irrigation districts. New hydrological insights for the region: A general good agreement was obtained between observed and reanalysis agrometeorological variables at both daily and seasonal scales. The best perfor-mance was obtained for T-air, followed by RH, R-s, and u(10) for both reanalysis datasets, especially under temperate climate conditions. These performances were translated into slightly higher accuracy of ET0 estimates by ERA5-Land product, confirming the potential of using reanalysis datasets as an alternative data source for retrieving the ET0 and overcoming the unavailability of observed agrometeorological data

VizieR Online Data Catalog: C2O and C3O in low-mass star-forming region

Data reported in Figure 1 correspond to newly detected C2O and lines towards: L1544 (panels A, B, C, D, E and F); L1498 (panels G and H); and Elias 18 (panels I and J). Each panel reports the molecule and its transition. The detection reported in panel G (performed with the Noto-32m telescope) was acquired with a lower resolution than that used for the observations reported in the other panels (IRAM-30m telescope). For clarity we give a larger VLSR scale that allows a better evaluation of the baseline. Table 1 and Table 2 in the paper report information on the spectroscopic parameters and telescope used. Further details are given in Section 2 in the paper. Files are given in FITS and ASCII format for each panel. (3 data files)

Association between preoperative evaluation with lung ultrasound and outcome in frail elderly patients undergoing orthopedic surgery for hip fractures: study protocol for an Italian multicenter observational prospective study (LUSHIP)

Hip fracture is one of the most common orthopedic causes of hospital admission in frail elderly patients. Hip fracture fixation in this class of patients is considered a high-risk procedure. Preoperative physical examination, plasma natriuretic peptide levels (BNP, Pro-BNP), and cardiovascular scoring systems (ASA-PS, RCRI, NSQIP-MICA) have all been demonstrated to underestimate the risk of postoperative complications. We designed a prospective multicenter observational study to assess whether preoperative lung ultrasound examination can predict better postoperative events thanks to the additional information they provide in the form of "indirect" and "direct" cardiac and pulmonary lung ultrasound signs

Acute diverticulitis management: evolving trends among Italian surgeons. A survey of the Italian Society of Colorectal Surgery (SICCR)

Acute diverticulitis (AD) is associated with relevant morbidity/mortality and is increasing worldwide, thus becoming a major issue for national health systems. AD may be challenging, as clinical relevance varies widely, ranging from asymptomatic picture to life-threatening conditions, with continuously evolving diagnostic tools, classifications, and management. A 33-item-questionnaire was administered to residents and surgeons to analyze the actual clinical practice and to verify the real spread of recent recommendations, also by stratifying surgeons by experience. CT-scan remains the mainstay of AD assessment, including cases presenting with recurrent mild episodes or women of child-bearing age. Outpatient management of mild AD is slowly gaining acceptance. A conservative management is preferred in non-severe cases with extradigestive air or small/non-radiologically drainable abscesses. In severe cases, a laparoscopic approach is preferred, with a non-negligible number of surgeons confident in performing emergency complex procedures. Surgeons are seemingly aware of several options during emergency surgery for AD, since the rate of Hartmann procedures does not exceed 50% in most environments and damage control surgery is spreading in life-threatening cases. Quality of life and history of complicated AD are the main indications for delayed colectomy, which is mostly performed avoiding the proximal vessel ligation, mobilizing the splenic flexure and performing a colorectal anastomosis. ICG is spreading to check anastomotic stumps' vascularization. Differences between the two experience groups were found about the type of investigation to exclude colon cancer (considering the experience only in terms of number of colectomies performed), the size of the peritoneal abscess to be drained, practice of damage control surgery and the attitude towards colovesical fistula