Chiral molecule formation in interstellar ice analogs: alpha-aminoethanol NH 2 CH(CH 3 )OH

International audienceAims. Aminoalcohol molecules such as alpha-aminoethanol NH 2 CH(CH 3)OH may be aminoacid precursors. We attempt to charac-terize and detect this kind of molecules which is important to establish a possible link between interstellar molecules and life as we know it on Earth. Methods. We use Fourier transform infrared (FTIR) spectroscopy and mass spectrometry to study the formation of alpha-aminoethanol NH 2 CH(CH 3)OH in H 2 O:NH 3 : CH 3 CHO ice mixtures. Isotopic substitution with 15 NH 3 and ab-initio calculation are used to confirm the identification of alpha-aminoethanol. Results. After investigating the thermal reaction of solid NH 3 and acetaldehyde CH 3 CHO at low temperature, we find that this reac-tion leads to the formation of a chiral molecule, the alpha aminoethanol NH 2 CH(CH 3)OH. For the first time, we report the infrared and mass spectra of this molecule. We also report on its photochemical behavior under VUV irradiation. We find that the main photo-product is acetamide (NH 2 COCH 3). Data provided in this work indicates that alpha-aminoethanol is formed in one hour at 120 K and suggests that its formation in warm interstellar environments such as protostellar envelopes or cometary environments is likely

Experimental investigation of aminoacetonitrile formation through the Strecker synthesis in astrophysical-like conditions: reactivity of methanimine (CH2NH), ammonia (NH3), and hydrogen cyanide (HCN)

International audienceAstronomy & Astrophysics Experimental investigation of aminoacetonitrile formation through the Strecker synthesis in astrophysical-like conditions: reactivity of methanimine (CH 2 NH), ammonia (NH 3), and hydrogen cyanide (HCN) ABSTRACT Context. Studing chemical reactivity in astrophysical environments is an important means for improving our understanding of the origin of the organic matter in molecular clouds, in protoplanetary disks, and possibly, as a final destination, in our solar system. Laboratory simulations of the reactivity of ice analogs provide important insight into the reactivity in these environments. Here, we use these experimental simulations to investigate the Strecker synthesis leading to the formation of aminoacetonitrile in astrophysical-like conditions. The aminoacetonitrile is an interesting compound because it was detected in SgrB2, hence could be a precursor of the smallest amino acid molecule, glycine, in astrophysical environments. Aims. We present the first experimental investigation of the formation of aminoacetonitrile NH 2 CH 2 CN from the thermal processing of ices including methanimine (CH 2 NH), ammonia (NH 3), and hydrogen cyanide (HCN) in interstellar-like conditions without VUV photons or particules. Methods. We use Fourier Transform InfraRed (FTIR) spectroscopy to monitor the ice evolution during its warming. Infrared spec-troscopy and mass spectroscopy are then used to identify the aminoacetonitrile formation. Results. We demonstrate that methanimine can react with − CN during the warming of ice analogs containing at 20 K methanimine, ammonia, and [NH + 4 − CN] salt. During the ice warming, this reaction leads to the formation of poly(methylene-imine) polymers. The polymer length depend on the initial ratio of mass contained in methanimine to that in the [NH + 4 − CN] salt. In a methanimine excess, long polymers are formed. As the methanimine is progressively diluted in the [NH + 4 − CN] salt, the polymer length decreases until the aminoacetonitrile formation at 135 K. Therefore, these results demonstrate that aminoacetonitrile can be formed through the second step of the Strecker synthesis in astrophysical-like conditions

Prognostic factors in stage III-IV adrenocortical carcinomas (ACC): an European Network for the Study of Adrenal Tumor (ENSAT) study.

BACKGROUND: The clinical course of advanced adrenocortical carcinoma (ACC) is heterogeneous. Our study aimed primarily to refine and make headway in the prognostic stratification of advanced ACC. PATIENTS AND METHODS: Patients with advanced ENSAT ACC (stage III or stage IV) at diagnosis registered between 2000 and 2009 in the ENSAT database were enrolled. The primary end point was overall survival (OS). Parameters of potential prognostic relevance were selected. Univariate and multivariate analyses were carried out: model 1 'before surgery'; model 2 'post-surgery'. RESULTS: Four hundred and forty-four patients with advanced ENSAT ACC (stage III: 210; stage IV: 234) were analyzed. After a median follow-up of 55.2 months, the median OS was 24 months. A modified ENSAT (mENSAT) classification was validated: stage III (invasion of surrounding tissues/organs or the vena renalis/cava) and stage IVa, IVb, IVc (2, 3 or >3 metastatic organs, including N, respectively). Two- or 5-year OS was 73%, 46%, 26% and 15% or 50%, 15%, 14% and 2% for stages III, IVa, IVb and IVc, respectively. In the multivariate analysis, mENSAT stages (stages IVa, IVb, or IVc, respectively) were significantly correlated with OS (P 6 and/or Ki67 ≥20%, P = 0.06) in model 2. CONCLUSION: The mENSAT classification and GRAS parameters (Grade, R status, Age and Symptoms) were found to best stratify the prognosis of patients with advanced ACC

Vandetanib for the Treatment of Advanced Medullary Thyroid Cancer Outside a Clinical Trial: Results from a French Cohort

BACKGROUND: A randomized phase III trial demonstrated that vandetanib treatment is effective in patients with metastatic medullary thyroid cancer (MTC), leading to regulatory approval, but its use may be associated with toxicities that require specific monitoring and management. The objective of the present study performed in France was to describe the toxicity profile and efficacy of vandetanib treatment when given outside any trial. METHODS: Sixty-eight patients were treated with vandetanib in the frame of a temporary use authorization (ATU) in France from August 2010 to February 2012, when the drug was available on request for patients with locally advanced or metastatic MTC. Patients were registered by the French health authorities, and characteristics, treatment parameters, toxicity profile, and efficacy were retrospectively reviewed. Eight patients were excluded from the analysis because vandetanib treatment was not administered (n=3), had been given in a trial before ATU (n=3), or was given for a non-MTC cancer (n=2). RESULTS: Data from the 60 MTC patients were analyzed. Mean age was 58 years (range 11-83 years), 39 patients were male, and six had hereditary MTC. Fifty-six (93%) had metastatic disease in the mediastinum (82%), bones (65%), liver (53%), or lung (53%), and four had only locally advanced disease. At the time of study evaluation, with a median follow-up of 20 months and a median duration of treatment of 9.7 months (range 0.3-36 months), 15 patients were continuing vandetanib treatment (range 18-36 months). Median progression-free survival was 16.1 months. Twenty-five patients discontinued treatment for disease progression (range 0.3-29 months). Best tumor response was a complete response in one patient, a partial response in 12 (20%), stable disease in 33 (55%), and progression in seven patients (12%). All patients had at least one adverse event (AE) during treatment. The main AEs were skin toxicity, diarrhea, and asthenia. Sixteen patients (27%) discontinued treatment for toxicity, and one patient died from vandetanib-induced cardiac toxicity. CONCLUSIONS: Vandetanib is an effective option for patients with advanced MTC. AEs should be monitored carefully and should be minimized by educating both patients and care providers and by applying symptomatic treatment and dose reduction

Scientific rationale for Uranus and Neptune <i>in situ</i> explorations

The ice giants Uranus and Neptune are the least understood class of planets in our solar system but the most frequently observed type of exoplanets. Presumed to have a small rocky core, a deep interior comprising ∼70% heavy elements surrounded by a more dilute outer envelope of H2 and He, Uranus and Neptune are fundamentally different from the better-explored gas giants Jupiter and Saturn. Because of the lack of dedicated exploration missions, our knowledge of the composition and atmospheric processes of these distant worlds is primarily derived from remote sensing from Earth-based observatories and space telescopes. As a result, Uranus's and Neptune's physical and atmospheric properties remain poorly constrained and their roles in the evolution of the Solar System not well understood. Exploration of an ice giant system is therefore a high-priority science objective as these systems (including the magnetosphere, satellites, rings, atmosphere, and interior) challenge our understanding of planetary formation and evolution. Here we describe the main scientific goals to be addressed by a future in situ exploration of an ice giant. An atmospheric entry probe targeting the 10-bar level, about 5 scale heights beneath the tropopause, would yield insight into two broad themes: i) the formation history of the ice giants and, in a broader extent, that of the Solar System, and ii) the processes at play in planetary atmospheres. The probe would descend under parachute to measure composition, structure, and dynamics, with data returned to Earth using a Carrier Relay Spacecraft as a relay station. In addition, possible mission concepts and partnerships are presented, and a strawman ice-giant probe payload is described. An ice-giant atmospheric probe could represent a significant ESA contribution to a future NASA ice-giant flagship mission