Complex organic molecules in comets C/2012 F6 (Lemmon) and C/2013 R1 (Lovejoy): detection of ethylene glycol and formamide

A spectral survey in the 1 mm wavelength range was undertaken in the long-period comets C/2012 F6 (Lemmon) and C/2013 R1 (Lovejoy) using the 30 m telescope of the Institut de radioastronomie millim\'etrique (IRAM) in April and November-December 2013. We report the detection of ethylene glycol (CH$_2$OH)$_2$ (aGg' conformer) and formamide (NH$_2$CHO) in the two comets. The abundances relative to water of ethylene glycol and formamide are 0.2-0.3% and 0.02% in the two comets, similar to the values measured in comet C/1995 O1 (Hale-Bopp). We also report the detection of HCOOH and CH$_3$CHO in comet C/2013 R1 (Lovejoy), and a search for other complex species (methyl formate, glycolaldehyde).Comment: Accepted for publication as a Letter in Astronomy and Astrophysic

Feasibility of Double-Blind Clinical Trials with Oral Diacetylmorphine: A Randomized Controlled Phase II Study in an Inpatient Setting

The aim of this study was to evaluate the feasibility of conducting double-blind controlled randomized clinical trials using twice-a-day immediate-release oral diacetylmorphine (DAM) in heroin-dependent patients, by means of measuring the capacity of oral DAM to block opiate withdrawal and clinicians' ability to distinguish it from morphine and methadone. This was a randomized, phase II, double-blind, multicenter pilot study comparing immediate-release oral DAM, slow-release oral morphine and oral methadone administered twice a day during 10 days. Forty-five heroin-dependent patients were randomly assigned to these three treatment groups in an inpatient regime. Patients were stabilized with a mean of 350 mg (SD = 193) of immediate-release oral DAM, 108 mg (SD = 46.2) of slow-release oral morphine and 40 mg (SD = 17.9) of methadone. No statistically significant differences were found between any studied medication in clinical outcome. Neither patients nor clinicians were able to identify the administered medication. This study shows the feasibility of double-blind clinical trials using b.i.d. immediate-release oral DAM allowing further phase III clinical trials in the process of introducing oral DAM as a medication for heroin-dependent patients not responding to standard maintenance treatments

Optimal interactions of light with magnetic and electric resonant particles

This work studies the limits of far and near-field electromagnetic response of sub-wavelength scatterers, like the unitary limit and of lossless scatterers, and the ideal absorption limit of lossy particles. These limit behaviors are described in terms of analytic formulas that approximate finite size effects while rigorously including radiative corrections. This analysis predicts the electric and/or magnetic limit responses of both metallic and dielectric nanoparticles while quantitatively describing near-field enhancements.Comment: 9 pages, 8 figures, 2 table

Large excess of heavy nitrogen in both hydrogen cyanide and cyanogen from comet 17P/Holmes

From millimeter and optical observations of the Jupiter-family comet 17P/Holmes performed soon after its huge outburst of October 24, 2007, we derive 14 N/15N = 139 +/- 26 in HCN, and 14N/15N = 165 +/- 40 in CN, establishing that HCN has the same non-terrestrial isotopic composition as CN. The same conclusion is obtained for the long-period comet C/1995 O1 (Hale-Bopp) after a reanalysis of previously published measurements. These results are compatible with HCN being the prime parent of CN in cometary atmospheres. The 15N excess relative to the Earth atmospheric value indicates that N-bearing volatiles in the solar nebula underwent important N isotopic fractionation at some stage of Solar System formation. HCN molecules never isotopically equilibrated with the main nitrogen reservoir in the solar nebula before being incorporated in Oort-cloud and Kuiper-belt comets. The 12C/13C ratios in HCN and CN are measured to be consistent with the terrestrial value.Comment: Accepted for publication in the Astrophysical Journal (Letters) 4 page

Ethylene glycol in comet C/1995 O1 (Hale-Bopp)

We report the detection of ethylene glycol (HOCH_2CH_2OH) in comet C/1995 O1 (Hale-Bopp) from the analysis of archival radio spectra. Its production rate is ≈0.25% that of water, making it one of the most abundant organic molecules in cometary ices. This detection strengthens the similarity between interstellar and cometary material