In this Paper, we describe how we use stellar dynamics information to constrain the shape of the stellar initial mass function (IMF) in a sample of 27 early-type galaxies from the CALIFA survey. We ...obtain dynamical and stellar mass-to-light ratios, ... and ..., over a homogenous aperture of 0.5 R sub( e). We use the constraint ... to test two IMF shapes within the framework of the extended MILES stellar population models. We rule out a single power-law IMF shape for 75 per cent of the galaxies in our sample. Conversely, we find that a double power-law IMF shape with a varying high-mass end slope is compatible (within ...) with 95 per cent of the galaxies. We also show that dynamical and stellar IMF mismatch factors give consistent results for the systematic variation of the IMF in these galaxies. (ProQuest: ... denotes formulae/symbols omitted.)
In 1976, the Viking landers carried out the most comprehensive search for organics and microbial life in the martian regolith. Their results indicate that Mars' surface is lifeless and, surprisingly, ...depleted in organics at part-per-billion levels. Several biology experiments on the Viking landers gave controversial results that have since been explained by the presence of oxidizing agents on the surface of Mars. These oxidants may degrade abiotic or biological organics, resulting in their nondetection in the regolith. As several exploration missions currently focus on the detection of organics on Mars (or will do so in the near future), knowledge of the oxidative state of the surface is fundamental. It will allow for determination of the capability of organics to survive on a geological timescale, the most favorable places to seek them, and the best methods to process the samples collected at the surface. With this aim, we review the main oxidants assumed to be present on Mars, their possible formation pathways, and those laboratory studies in which their reactivity with organics under Mars-like conditions has been evaluated. Among the oxidants assumed to be present on Mars, only four have been detected so far: perchlorate ions (ClO
) in salts, hydrogen peroxide (H
O
) in the atmosphere, and clays and metal oxides composing surface minerals. Clays have been suggested as catalysts for the oxidation of organics but are treated as oxidants in the following to keep the structure of this article straightforward. This work provides an insight into the oxidizing potential of the surface of Mars and an estimate of the stability of organic matter in an oxidizing environment. Key Words: Mars surface-Astrobiology-Oxidant-Chemical reactions. Astrobiology 16, 977-996.
The deuterium-to-hydrogen (D/H) ratio in strongly bound water or hydroxyl groups in ancient martian clays retains the imprint of the water of formation of these minerals. Curiosity's Sample Analysis ...at Mars (SAM) experiment measured thermally evolved water and hydrogen gas released between 550° and 950°C from samples of Hesperian-era Gale crater smectite to determine this isotope ratio. The D/H value is 3.0 (±0.2) times the ratio in standard mean ocean water. The D/H ratio in this ∼3-billion-year-old mudstone, which is half that of the present martian atmosphere but substantially higher than that expected in very early Mars, indicates an extended history of hydrogen escape and desiccation of the planet.
Summary
Background
We have observed an increase in hepatotoxicity (DILI) reporting related to the use of anabolic androgenic steroids (AAS) for bodybuilding.
Aim
To characterise phenotype ...presentation, outcome and severity of AAS DILI.
Methods
Data on 25 cases of AAS DILI reported to the Spanish (20) and Latin‐American (5) DILI Registries were collated and compared with previously published cases.
Results
AAS DILI increased from representing less than 1% of the total cases in the Spanish DILI Registry in the period 2001–2009 to 8% in 2010–2013. Young men (mean age 32 years), requiring hospitalisation, hepatocellular injury and jaundice were predominating features among the AAS cases. AAS DILI caused significantly higher bilirubin values independent of type of damage when compared to other drug classes (P = 0.001). Furthermore, the cholestatic AAS cases presented significantly higher mean peak bilirubin (P = 0.029) and serum creatinine values (P = 0.0002), compared to the hepatocellular cases. In a logistic regression model, the interaction between peak bilirubin values and cholestatic damage was associated with the development of AAS‐induced acute kidney impairment (AKI) OR 1.26 (95% CI: 1.035–1.526); P = 0.021, with 21.5 ×ULN being the best bilirubin cut‐off point for predicting AKI risk (AUCROC 0.92). No fatalities occurred.
Conclusions
Illicit recreational AAS use is a growing cause of reported DILI that can lead to severe hepatic and renal injury. AAS DILI is associated with a distinct phenotype, characterised by considerable bilirubin elevations independent of type of damage. Although hepatocellular injury predominates, acute kidney injury develops in cholestatic cases with pronounced jaundice.
The quadrupole mass spectrometer of the Sample Analysis at Mars (SAM) instrument on Curiosity rover has made the first high‐precision measurement of the nonradiogenic argon isotope ratio in the ...atmosphere of Mars. The resulting value of 36Ar/38Ar = 4.2 ± 0.1 is highly significant for it provides excellent evidence that “Mars” meteorites are indeed of Martian origin, and it points to a significant loss of argon of at least 50% and perhaps as high as 85–95% from the atmosphere of Mars in the past 4 billion years. Taken together with the isotopic fractionations in N, C, H, and O measured by SAM, these results imply a substantial loss of atmosphere from Mars in the posthydrodynamic escape phase.
Key Points
First high‐precision measurement of primordial argon isotopes in Martian air
This measurement definitively ties the“martian” meteorites to Mars”
Requires massive loss of Martian atmosphere after the hydrodynamic escape phase
Thermochemolysis of seven nucleobases—adenine, thymine, uracil, cytosine, guanine, xanthine, and hypoxanthine—in tetramethylammonium hydroxide (TMAH) was studied individually by pyrolysis gas ...chromatography mass spectrometry in the frame of the Mars surface exploration. The analyses were performed under conditions relevant to the Sample Analysis at Mars (SAM) instrument of the Mars Curiosity Rover and the Mars Organic Molecule Analyzer (MOMA) instrument of the ExoMars Rover. The thermochemolysis products of each nucleobase were identified and the reaction mechanisms studied. The thermochemolysis temperature was optimized and the limit of detection and quantification of each nucleobase were also investigated. Results indicate that 600°C is the optimal thermochemolysis temperature for all seven nucleobases. The methylated products trimethyl-adenine, 1, 3-dimethyl-thymine, 1, 3-dimethyl-uracil, trimethyl-cytosine, 1, 3, 7-trimethyl-xanthine (caffeine), and dimethyl-hypoxanthine, respectively, are the most stable forms of adenine, thymine, uracil, cytosine, guanine, and xanthine, and hypoxanthine in TMAH solutions. The limits of detection for adenine, thymine, and uracil were 0.075 nmol; the limits of detection for guanine, cytosine, and hypoxanthine were higher, at 0.40, 0.55, and 0.75 nmol, respectively. These experiments allowed to well constrain the analytical capabilities of the thermochemolysis experiments that will be performed on Mars to detect nucleobases.
Display omitted
•Seven nucleobases were detected by GC-MS under conditions relevant to in situ operating instruments on Mars: SAM and MOMA.•The TMAH thermochemolysis products coming from seven nucleobases were determined.•The LOD and LOQ values of seven nucleobases in TMAH were determined after GC-MS analysis.•Results of the nucleobases thermochemolysis will help to identify those compounds on Mars with SAM and MOMA.
•Hydrothermal synthesis of TiO2-Ni(SO4)0.3(OH)1.4 nanocomposite.•Use of Graphite|TiO2-Ni(SO4)0.3(OH)1.4 as electrocatalytic anode in alkaline medium.•Electrochemical determination of kinetic ...parameters for meglumine oxidation.•Facile meglumine electrooxidation revealed by UHPLC-ESI-Q-TOF-MS analysis.•Effective electrooxidation of meglumine also in a commercial formulation.
The electrocatalytic oxidation of meglumine and gadoterate meglumine (Gd-DOTA) on a TiO2-Ni(SO4)0.3(OH)1.4 composite anode was investigated in alkaline medium (5 M KOH) using cyclic voltammetry and chronoamperometry. The composite was prepared by hydrothermal method and the morphology and structure of the produced nanoparticles were studied by scanning electron microscopy with energy-dispersive X-ray spectroscopy, X-ray diffraction, atomic force microscopy, BET surface area analysis and Fourier transform infrared spectroscopy. The characterization revealed the formation of Ni(SO4)0.3(OH)1.4 nanobelts dispersed on TiO2 nanoaggregates. The composite was coated onto a porous graphite rod, showing good adherence without requiring any binder (according to their anodic and cathodic charges). The supported composite was electrocatalytic, allowing the oxidation of meglumine, either as pure reagent or contained in gadoterate meglumine solutions. Electrochemical methods allowed determining the kinetic parameters, such as the electron transfer coefficient α, the total number of electrons n and the standard heterogeneous rate constant k0 for the reaction of meglumine. The chronoamperometric tests informed about the good stability of the composite anode upon meglumine oxidation at +0.6 V for 10 h. The electrochemical oxidation of meglumine in a commercial pharmaceutical formulation (Dotarem®) was corroborated via ultra-high performance liquid chromatography coupled to electrospray ionization and quadrupole time-of-flight mass spectrometry.
Abstract Objectives We aimed to determine whether body mass index (BMI) is a prognostic indicator for long-term, all-cause mortality in patients undergoing transcatheter aortic valve implantation ...(TAVI). Background Obesity in patients with established cardiovascular disease has previously been identified as an indicator of good prognosis, a phenomenon known as the “obesity paradox”. The prognostic significance of BMI in patients with severe aortic stenosis (AoS) undergoing TAVI is a matter of current debate, as published studies are scarce and their results conflicting. Methods This is an observational, retrospective study involving 770 patients who underwent TAVI for AoS. The cohort was divided into three groups based on their BMI: normal weight (≥ 18.5 to < 25 kg/m2 ), overweight (≥ 25 to < 30 kg/m2 ) and obese (≥ 30 kg/m2 ). The predictive effect of BMI on all-cause mortality 3 years following TAVI intervention was analysed using a Cox regression. Results 155 patients died during follow-up. The overweight group ( n = 302, 38.97%), experienced a lower mortality rate compared to the normal weight and obese groups (15.9% vs 25.7% and 21.0%, respectively log-rank p -value = 0.036). After adjustment by logistic EuroSCORE, being overweight was found to be an independent protective factor against mortality (HR: 0.63 95% CI: 0.42 to 0.94, p = 0.024). This was not the case for obesity (HR: 0.92 95% CI: 0.63 to 1.35, p = 0.664). We therefore describe for the first time, a “J-shaped” regression curve describing the relationship between BMI and mortality. Conclusions BMI is a predictive factor of all-cause mortality in AoS patients undergoing TAVI. This relationship takes the form of a “J-shaped” curve in which overweight patients are associated with the lowest mortality rate at follow-up.
The first results obtained by the ACP experiment onboard Huygens probe revealed that the main products obtained after thermolysis of Titan's collected aerosols, were ammonia (NH3) and hydrogen ...cyanide (HCN). Titan's aerosols, and their laboratory analogues named tholins, have been the subject of experimental or theoretical studies during the last four decades. These studies have been mainly devoted to understanding their origin and formation mechanisms, their physical, chemical and optical properties, and their role in the radiative equilibrium of the satellite. Before the arrival of the Cassini–Huygens mission, the dense layer of aerosols hid many aspects of the satellite's surface and precious information about its composition.
If Titan's aerosols have been in the eye and mind of planetary scientists during such a long time, it is not surprising that a literature survey displays a good quantity of papers on aerosol analogues. With aerosol analogues we mean any material produced in a terrestrial laboratory under conditions that try to represent those of Titan's atmosphere. We present here a study aimed to understand the particularities of aerosol analogues synthesized in different laboratories around the world in order to determine some of their most representative chemical fingerprints and in some cases, to perform a direct comparison of the volatiles produced after a thermal treatment done in conditions similar to the ones used by the ACP experiment. From the information collected, we propose a broad classification of aerosol analogues highlighting the materials that can be more representative of Titan's aerosols in terms of their content of organic volatiles. We identify the laboratory analogs that best suit the ACP results; such identification is of prime importance to correctly predict the optical properties of Titan's aerosol and to accurately estimate their contribution in radiative equilibrium models and/or to assess their role in chemical reactions of astrobiological importance at Titan's surface.
► Final exploitation of Huygens mission Data. ► Intercomparison between in situ results and laboratory investigations. ► Titan's chemistry complexity confirmed. ► Orientation of future laboratory simulations of Titan's gas/particulate chemistry.
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