93 research outputs found

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

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    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)

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    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

    Economic evaluation of Medically Assisted Reproduction: An educational overview of methods and applications for healthcare professionals

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    Economic evaluations of the value-for-money of Medically Assisted Reproduction (MAR) interventions are increasingly important due to growing pressure on healthcare budgets. Although such evaluations are commonplace in the published literature, the number/methodological complexity of different evaluations available, and the challenges specific to MAR interventions, can complicate the interpretation of such analyses for fertility treatments. This article aims to serve as an educational resource and provide context on the design/interpretation of economic analyses for MAR interventions. Several areas are relevant for first-line providers and decision makers: scope of analysis, comparator used, perspective/time horizon considered, outcomes used to measure success, and how results from cost-effectiveness studies can be summarised and used in clinical practice. We aim to help clinicians better understand the strengths/weaknesses of economic analyses, to enable the best use of the evidence in practice, so resources available for MAR interventions can provide maximum value to patients and society

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

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    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

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    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

    Diagnóstico, tratamento e seguimento do carcinoma medular de tireoide: recomendaçÔes do Departamento de Tireoide da Sociedade Brasileira de Endocrinologia e Metabologia

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    Economic evaluation of first-line and maintenance treatments for advanced non-small cell lung cancer: a systematic review

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    Christos Choua&iuml;d,1 Perinne Crequit,2 Isabelle Borget,3 Alain Vergnenegre4 1Service de Pneumologie et de Pathologie Professionnelle, Centre Hospitalier Intercommunal Cr&eacute;teil et Universit&eacute; de Paris Est Cr&eacute;teil, Paris, France; 2Service de Pneumologie, H&ocirc;pital Tenon, Assistance Publique-H&ocirc;pitaux de Paris, Paris, France; 3Service de Biostatistique et d&rsquo;Epid&eacute;miologie, Institut Gustave Roussy, Villejuif, France; 4Unit&eacute; d&rsquo;Oncologie Thoracique et Cutan&eacute;e, Centre Hospitalier Universitaire Limoges, Limoges, France Abstract: During these last years, there have been an increased number of new drugs for non-small cell lung cancer (NSCLC), with a growing financial effect on patients and society. The purpose of this article was to review the economics of first-line and maintenance NSCLC treatments. We reviewed economic analyses of NSCLC therapies published between 2004 and 2014. In first-line settings, in unselected patients with advanced NSCLC, the cisplatin gemcitabine doublet appears to be cost-saving compared with other platinum doublets. In patients with nonsquamous NSCLC, the incremental cost-effectiveness ratios (ICERs) per life-year gained (LYG) were 83,537,83,537, 178,613, and more than 300,000forcisplatin−pemetrexedcomparedwith,respectively,cisplatin−gemcitabine,cisplatin−carboplatin−paclitaxel,andcarboplatin−paclitaxel−bevacizumab.Forallprimarychemotherapyagents,useofcarboplatinisassociatedwithslightlyhighercoststhancisplatin.Inalltheanalysis,bevacizumabhadanICERgreaterthan300,000 for cisplatin-pemetrexed compared with, respectively, cisplatin-gemcitabine, cisplatin-carboplatin-paclitaxel, and carboplatin-paclitaxel-bevacizumab. For all primary chemotherapy agents, use of carboplatin is associated with slightly higher costs than cisplatin. In all the analysis, bevacizumab had an ICER greater than 150,000 per quality-adjusted life-year (QALY). In epidermal growth factor receptor mutated advanced NSCLC, compared with carboplatin-paclitaxel doublet, targeted therapy based on testing available tissue yielded an ICER of 110,644perQALY,andtherebiopsystrategyyieldedanICERof110,644 per QALY, and the rebiopsy strategy yielded an ICER of 122,219 per QALY. Compared with the triplet carboplatin-paclitaxel-bevacizumab, testing and rebiopsy strategies had ICERs of 25,547and25,547 and 44,036 per QALY, respectively. In an indirect comparison, ICERs per LYG and QALY of erlotinib versus gefitinib were 39,431and39,431 and 62,419, respectively. In anaplastic lymphoma kinase-positive nonsquamous advanced NSCLC, the ICER of first-line crizotinib compared with that of chemotherapy was 255,970perQALY.Formaintenancetherapy,gefitinibhadanICERof255,970 per QALY. For maintenance therapy, gefitinib had an ICER of 19,214 per QALY, erlotinib had an ICER of 127,343perLYG,andpemetrexedhadanICERvaryingbetween127,343 per LYG, and pemetrexed had an ICER varying between 183,589 and 205,597perLYG.MostrecentNSCLCstrategiesarebasedonapparentlynocost−effectivestrategiesifweconsideranICERbelow205,597 per LYG. Most recent NSCLC strategies are based on apparently no cost-effective strategies if we consider an ICER below 50,000 per QALY an acceptable threshold. We need, probably on a countrywide level, to have a debate involving public health organizations and pharmaceutical companies, as well as clinicians and patients, to challenge the rising costs of managing lung cancer. Keywords: lung cancer, costs, economics, cost-effectiveness, evaluatio
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