Delayed Severe Drug Induced Cholestasis After Anabolic Steroids Exposure

Anabolic steroids therapy is linked to a distinctive form of acute cholestasis that generally arises within 1 to 4 months of starting therapy but may be delayed to as long as 6 to 24 months in some reported cases. We are presenting an unusual case where acute cholestasis happened 5 weeks after discontinuing short course (7 days) of anabolic steroids. A 20-year-old African American male without significant past medical history presented with jaundice, mild nausea and generalized pruritis. He admitted to self-initiation of oral Stanozolol 40 mg daily for 7-days about 5 weeks before his admission. No prior incidence and no significant alcohol use. Vitals signs unremarkable and physical exam was unremarkable except for jaundice and sclera icterus. No hepatosplenomegaly. Liver function profile with ALT 44 IU/L, AST 72 IU/L, ALP 266 IU/L, & total bilirubin of 21.4 mg/Dl. Extensive hepatitis workup was negative and a CT-guided liver biopsy was performed which showed marked hepatocanalicular cholestasis. This is reflective of drug induced cholestasis. Our case highlights the possibility of delayed liver injury even after a short anabolic steroids course which typically happen while taking the medication for an extended period (more than 1 month)

Source apportionment of submicron organic aerosols at an urban site by linear unmixing of aerosol mass spectra

International audienceSubmicron ambient aerosol was characterized in summer 2005 at an urban background site in Zurich, Switzerland, during a three-week measurement campaign. Highly time-resolved samples of non-refractory aerosol components were analyzed with an Aerodyne aerosol mass spectrometer (AMS). Positive matrix factorization (PMF) was used for the first time for AMS data to identify the main components of the total organic aerosol and their sources. The PMF retrieved factors were compared to measured reference mass spectra and were correlated with tracer species of the aerosol and gas phase measurements from collocated instruments. Six factors were found to explain virtually all variance in the data and could be assigned either to sources or to aerosol components such as oxygenated organic aerosol (OOA). Our analysis suggests that at the measurement site only a small (1 originates from freshly emitted fossil fuel combustion. Other primary sources identified to be of similar or even higher importance are charbroiling (10?15%) and wood burning (~10%), along with a minor source interpreted to be influenced by food cooking (6%). The fraction of all identified primary sources is considered as primary organic aerosol (POA). This interpretation is supported by calculated ratios of the modelled POA and measured primary pollutants such as elemental carbon (EC), NOx, and CO, which are in good agreement to literature values. A high fraction (60?69%) of the measured organic aerosol mass is OOA which is interpreted mostly as secondary organic aerosol (SOA). This oxygenated organic aerosol can be separated into a highly aged fraction, OOA I, (40?50%) with low volatility and a mass spectrum similar to fulvic acid, and a more volatile and probably less processed fraction, OOA II (on average 20%). This is the first publication of a multiple component analysis technique to AMS organic spectral data and also the first report of the OOA II component

Assessment of the Current Frequency Calculation Methods Used in the Determination of the Dynamic Modulus Value in Pavement Design and Analysis

The dynamic modulus |E*| is used in the Mechanistic-Empirical Pavement Design Guide (MEPDG) to express the viscoelasticity of asphalt material at a range of temperatures and loading frequencies. As a result, the current MEPDG method assumes that frequency is calculated as the opposite of vehicular loading pulse time. In addition, the loading pulse time can be calculated using the Odemark thickness equivalency method according to the MEPDG. On the other hand, the loading frequency as per Qatar Highway Design Manual (QHDM 2021) is estimated based on the average vehicle speed using Losa and Di Natale formula. However, studies found major inadequacies in the adopted method of MEPDG, which might affect the accuracy of the loading frequency and |E*| accordingly which leads to an impact on the pavement design and performance analysis. Hence, it was recommended that alternative frequency determination approaches like the Fast Fourier Transform (FFT) be used rather than traditional time-domain techniques. Therefore, this paper compares the results of the MEPDG and QHDM loading frequency procedure with the dominant frequencies (DF) obtained using the FFT. On the other hand, the loading time pulses are estimated using the Odemark approach and, compared to the ones simulated using 3D Move Analysis software that accurately considers the tire contact pressure, viscoelastic properties, & vehicle speed. It was found that the used frequency determination approach in the pavement design in Qatar, overestimates the frequency values by about 30% to 88%. Furthermore, the findings showed that the MEPDG method for determining loading time and frequency is not conservative

Size and composition measurements of background aerosol and new particle growth in a Finnish forest during QUEST 2 using an Aerodyne Aerosol Mass Spectrometer

International audienceThe study of the growth of nucleation-mode particles is important, as this prevents their loss through diffusion and allows them to reach sizes where they may become effective cloud condensation nuclei. Hyytiälä, a forested site in southern Finland, frequently experiences particle nucleation events during the spring and autumn, where particles first appear during the morning and continue to grow for several hours afterwards. As part of the QUEST 2 intensive field campaign during March and April 2003, an Aerodyne Aerosol Mass Spectrometer (AMS) was deployed alongside other aerosol instrumentation to study the particulate composition and dynamics of growth events and characterise the background aerosol. Despite the small mass concentrations, the AMS was able to distinguish the grown particles in the <100 nm regime several hours after an event and confirm that the particles were principally organic in composition. The AMS was also able to derive a mass spectral fingerprint for the organic species present, and found that it was consistent between events and independent of the mean particle diameter during non-polluted cases, implying the same species were also condensing onto the accumulation mode. The results were compared with those from offline analyses such as GC-MS and were consistent with the hypothesis that the main components were alkanes from plant waxes and the oxidation products of terpenes

Estudio aplicación del modelo de madurez capacidad de ingeniería. En seguridad de los sistemas (SSE-CMM) por áreas de proyecto y organización

<p>Secondary organic aerosol (SOA) particles have been found to be efficient ice-nucleating particles under the cold conditions of (tropical) upper-tropospheric cirrus clouds. Whether they also are efficient at initiating freezing under slightly warmer conditions as found in mixed-phase clouds remains undetermined. Here, we study the ice-nucleating ability of photochemically produced SOA particles with the combination of the Manchester Aerosol Chamber and Manchester Ice Cloud Chamber. Three SOA systems were tested resembling biogenic and anthropogenic particles as well as particles of different phase state. These are namely <i>α</i>-pinene, heptadecane, and 1,3,5-trimethylbenzene. After the aerosol particles were formed, they were transferred into the cloud chamber, where subsequent quasi-adiabatic cloud activation experiments were performed. Additionally, the ice-forming abilities of ammonium sulfate and kaolinite were investigated as a reference to test the experimental setup. <br/><br/> Clouds were formed in the temperature range of &minus;20 to &minus;28.6 °C. Only the reference experiment using dust particles showed evidence of ice nucleation. No ice particles were observed in any other experiment. Thus, we conclude that SOA particles produced under the conditions of the reported experiments are not efficient ice-nucleating particles starting at liquid saturation under mixed-phase cloud conditions.</p

A method for extracting calibrated volatility information from the FIGAERO-HR-ToF-CIMS and its experimental application

The Filter Inlet for Gases and AEROsols (FIGAERO) is an inlet specifically designed to be coupled with the Aerodyne High-Resolution Time-of-Flight Chemical Ionization Mass Spectrometer (HR-ToF-CIMS). The FIGAERO-HR-ToF-CIMS provides simultaneous molecular information relating to both the gas- and particle-phase samples and has been used to extract vapour pressures (VPs) of the compounds desorbing from the filter whilst giving quantitative concentrations in the particle phase. However, such extraction of vapour pressures of the measured particle-phase components requires use of appropriate, well-defined, reference compounds. Vapour pressures for the homologous series of polyethylene glycols (PEG) ((H-(O-CH2CH2)n-OH) for n = 3 to n = 8), covering a range of vapour pressures (VP) (10-1 to 10-7 Pa) that are atmospherically relevant, have been shown to be reproduced well by a range of different techniques, including Knudsen Effusion Mass Spectrometry (KEMS). This is the first homologous series of compounds for which a number of vapour pressure measurement techniques have been found to be in agreement, indicating the utility as a calibration standard, providing an ideal set of benchmark compounds for accurate characterization of the FIGAERO for extracting vapour pressure of measured compounds in chambers and the real atmosphere. To demonstrate this, single-component and mixture vapour pressure measurements are made using two FIGAERO-HR-ToF-CIMS instruments based on a new calibration determined from the PEG series. VP values extracted from both instruments agree well with those measured by KEMS and reported values from literature, validating this approach for extracting VP data from the FIGAERO. This method is then applied to chamber measurements, and the vapour pressures of known products are estimated

Emissions of biogenic volatile organic compounds and subsequent photochemical production of secondary organic aerosol in mesocosm studies of temperate and tropical plant species

Silver birch (Betula pendula) and three Southeast Asian tropical plant species (Ficus cyathistipula, Ficus benjamina and Caryota millis) from the pantropical fig and palm genera were grown in a purpose-built and environment-controlled whole-tree chamber. The volatile organic compounds emitted from these trees were characterised and fed into a linked photochemical reaction chamber where they underwent photo-oxidation under a range of controlled conditions (relative humidity or RH ~65–89%, volatile organic compound-to-NOx or VOC / NOx ~3–9 and NOx ~2 ppbV). Both the gas phase and the aerosol phase of the reaction chamber were monitored in detail using a comprehensive suite of on-line and off-line chemical and physical measurement techniques. Silver birch was found to be a high monoterpene and sesquiterpene but low isoprene emitter, and its emissions were observed to produce measurable amounts of secondary organic aerosol (SOA) via both nucleation and condensation onto pre-existing seed aerosol (YSOA 26–39%). In contrast, all three tropical species were found to be high isoprene emitters with trace emissions of monoterpenes and sesquiterpenes. In tropical plant experiments without seed aerosol there was no measurable SOA nucleation, but aerosol mass was shown to increase when seed aerosol was present. Although principally isoprene emitting, the aerosol mass produced from tropical fig was mostly consistent (i.e. in 78 out of 120 aerosol mass calculations using plausible parameter sets of various precursor specific yields) with condensation of photo-oxidation products of the minor volatile organic compounds (VOCs) co-emitted; no significant aerosol yield from condensation of isoprene oxidation products was required in the interpretations of the experimental results. This finding is in line with previous reports of organic aerosol loadings consistent with production from minor biogenic VOCs co-emitted with isoprene in principally isoprene-emitting landscapes in Southeast Asia. Moreover, in general the amount of aerosol mass produced from the emissions of the principally isoprene-emitting plants was less than would be expected from published single-VOC experiments, if co-emitted species were solely responsible for the final SOA mass. Interpretation of the results obtained from the fig data sets leaves room for a potential role for isoprene in inhibiting SOA formation under certain ambient atmospheric conditions, although instrumental and experimental constraints impose a level of caution in the interpretation of the results. Concomitant gas- and aerosol-phase composition measurements also provide a detailed overview of numerous key oxidation mechanisms at work within the systems studied, and their combined analysis provides insight into the nature of the SOA formed