36 research outputs found

    SN 2020zbf: A fast-rising hydrogen-poor superluminous supernova with strong carbon lines

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    SN 2020zbf is a hydrogen-poor superluminous supernova at z=0.1947z = 0.1947 that shows conspicuous C II features at early times, in contrast to the majority of H-poor SLSNe. Its peak magnitude is MgM_{\rm g} = 21.2-21.2 mag and its rise time (24\lesssim 24 days from first light) place SN 2020zbf among the fastest rising SLSNe-I. Spectra taken from ultraviolet (UV) to near-infrared wavelengths are used for the identification of spectral features. We pay particular attention to the C II lines as they present distinctive characteristics when compared to other events. We also analyze UV and optical photometric data, and model the light curves considering three different powering mechanisms: radioactive decay of Ni, magnetar spin-down and circumstellar material interaction (CSM). The spectra of SN 2020zbf match well with the model spectra of a C-rich low-mass magnetar model. This is consistent with our light curve modelling which supports a magnetar-powered explosion with a MejM_{\rm ej} = 1.5 MM_\odot. However, we cannot discard the CSM-interaction model as it also may reproduce the observed features. The interaction with H-poor, carbon-oxygen CSM near peak could explain the presence of C II emission lines. A short plateau in the light curve, around 30 - 40 days after peak, in combination with the presence of an emission line at 6580 \r{A} can also be interpreted as late interaction with an extended H-rich CSM. Both the magnetar and CSM interaction models of SN 2020zbf indicate that the progenitor mass at the time of explosion is between 2 - 5 MM_\odot. Modelling the spectral energy distribution of the host reveals a host mass of 108.7^{8.7} MM_\odot, a star-formation rate of 0.240.12+0.41^{+0.41}_{-0.12} MM_\odot yr1^{-1} and a metallicity of \sim 0.4 ZZ_\odot.Comment: 26 pages, 22 figures, submitted to A&

    Cumulative incidence and risk factors for cutaneous squamous-cell carcinoma metastases in organ transplant recipients: the SCOPE-ITSCC metastases study, a prospective multi-center study.

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    Solid organ transplant recipients (SOTRs) are believed to have an increased risk of metastatic cutaneous squamous-cell carcinoma (cSCC), but reliable data are lacking regarding the precise incidence and associated risk factors. In a prospective cohort study, including 19 specialist dermatology outpatient clinics in 15 countries, patient and tumor characteristics were collected using standardized questionnaires when SOTRs presented with a new cSCC. After a minimum of 2 years of follow-up, relevant data for all SOTRs were collected. Cumulative incidence of metastases was calculated by the Aalen-Johansen estimator. Fine and Gray models were used to assess multiple risk factors for metastases. Of 514 SOTRs who presented with 623 primary cSCCs, 37 developed metastases with a 2-year patient-based cumulative incidence of 6.2%. Risk factors for metastases included location in the head and neck area, local recurrence, size >2cm, clinical ulceration, poor differentiation grade, perineural invasion and deep invasion. A high-stage tumor that is also ulcerated showed the highest risk of metastasis, with a 2-year cumulative incidence of 46.2% (31.9% - 68.4%). SOTRs have a high risk of cSCC metastases and well-established clinical and histological risk factors have been confirmed. High-stage, ulcerated cSCCs have the highest risk of metastasis. [Abstract copyright: Copyright © 2024. Published by Elsevier Inc.

    Global patient outcomes after elective surgery: prospective cohort study in 27 low-, middle- and high-income countries.

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    BACKGROUND: As global initiatives increase patient access to surgical treatments, there remains a need to understand the adverse effects of surgery and define appropriate levels of perioperative care. METHODS: We designed a prospective international 7-day cohort study of outcomes following elective adult inpatient surgery in 27 countries. The primary outcome was in-hospital complications. Secondary outcomes were death following a complication (failure to rescue) and death in hospital. Process measures were admission to critical care immediately after surgery or to treat a complication and duration of hospital stay. A single definition of critical care was used for all countries. RESULTS: A total of 474 hospitals in 19 high-, 7 middle- and 1 low-income country were included in the primary analysis. Data included 44 814 patients with a median hospital stay of 4 (range 2-7) days. A total of 7508 patients (16.8%) developed one or more postoperative complication and 207 died (0.5%). The overall mortality among patients who developed complications was 2.8%. Mortality following complications ranged from 2.4% for pulmonary embolism to 43.9% for cardiac arrest. A total of 4360 (9.7%) patients were admitted to a critical care unit as routine immediately after surgery, of whom 2198 (50.4%) developed a complication, with 105 (2.4%) deaths. A total of 1233 patients (16.4%) were admitted to a critical care unit to treat complications, with 119 (9.7%) deaths. Despite lower baseline risk, outcomes were similar in low- and middle-income compared with high-income countries. CONCLUSIONS: Poor patient outcomes are common after inpatient surgery. Global initiatives to increase access to surgical treatments should also address the need for safe perioperative care. STUDY REGISTRATION: ISRCTN5181700

    Spectroscopic observations of progenitor activity 100 days before a Type Ibn supernova ⋆

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    Obtaining spectroscopic observations of the progenitors of core-collapse supernovae is often unfeasible, due to an inherent lack of knowledge as to what stars experience supernovae and when they will explode. In this Letter we present photometric and spectroscopic observations of the progenitor activity of SN 2023fyq before the He-rich progenitor explodes as a Type Ibn supernova. The progenitor of SN 2023fyq shows an exponential rise in flux prior to core collapse. Complex He i emission line features are observed in the progenitor spectra, with a P Cygni-like profile, as well as an evolving broad base with velocities of the order of 10 000 km s-1. The luminosity and evolution of SN 2023fyq is consistent with a Type Ibn, reaching a peak r-band magnitude of-18:8 mag, although there is some uncertainty regarding the distance to the host, NGC 4388, which is located in the Virgo cluster. We present additional evidence of asymmetric He-rich material being present both prior to and after the explosion of SN 2023fyq, which suggests that this material survived the ejecta interaction. Broad [O i], C i, and the Ca ii triplet lines are observed at late phases, confirming that SN 2023fyq was a genuine supernova, rather than a non-Terminal interacting transient. SN 2023fyq provides insight into the final moments of a massive star's life, demonstrating that the progenitor is likely highly unstable before core collapse

    Atypical Trigeminal Trophic Syndrome: An Unusual Cause of Facial Ulceration

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    Metabolism of 2-acylglycerol in rabbit and human platelets. Involvement of monoacylglycerol lipase and fatty acid amide hydrolase

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    The endocannabinoids 2-arachidonoylglycerol (2-AG) and anandamide (N-arachidonoylethanolamine, AEA) are produced by neurons and other cells, including platelets, in a stimulus-dependent manner and act as signaling molecules; they are then inactivated through transport into cells followed by enzymatic degradation. A number of studies showed that monoacylglycerol lipase (MAGL) plays an important role in the degradation of 2-AG. In this study we investigated the enzymatic degradation of 2-acylglycerols in rabbit platelets and we characterized the responsible enzyme(s). [ 3H]2-AG and [ 3H]2-oleoylglycerol (2-OG) were both metabolized to [ 3H]glycerol and the respective fatty acid in a time and protein concentration-dependent manner, apparently by the action of MAGL activity. In the presence of the specific fatty acid amide hydrolase (FAAH) inhibitors URB597 and AM374, though, 2-OG hydrolysis was inhibited up to 55% in a concentration-dependent manner (Ic50 = 129.8 nM and 20.9 nM respectively). These results indicate the involvement of both MAGL and FAAH on 2-acylglycerol hydrolysis. MAGL was further characterized in the presence of URB597 and it was found that 2-monoacylglycerols were hydrolyzed in a time, pH and protein concentration-dependent manner and hydrolysis followed Michaelis-Menten kinetics, with an apparent KM of 0.11 μM and Vmax of 1.32 nmol/min*mg protein. Subcellular fractionation of platelet homogenate showed that MAGL activity was present in both the cytosolic and membrane fractions. In conclusion, the endocannabinoid 2-AG, as well as other 2-acylglycerols, are substrates of both FAAH and MAGL; the latter was characterized for the first time in platelets. In human platelets, under the same experimental conditions, the hydrolysis of 2-acylglycerols was higher and MAGL activity showed a different sensitivity against the inhibitors mentioned above. Finally, immunoblot analysis revealed the presence of MAGL, both in rabbit and human platelets, with a molecular mass of ∼ü33 kDa. © 2009 Informa UK Ltd All rights reserved

    Correction to: Molecular, biochemical and kinetic analysis of a novel, thermostable lipase (LipSm) from Stenotrophomonas maltophilia Psi‑1, the first member of a new bacterial lipase family (XIX)

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    We have recently (8th February 2018) published our article entitled “Molecular, biochemical and kinetic analysis of a novel, thermostable lipase (LipSm) from Stenotrophomonas maltophilia Psi-1, the first member of a new bacterial lipase family (XVIII)” [1]. While our manuscript was going through the final stages of publication, an article by Samoylova et al. [2] was published (12th January 2018) in the journal Extremophiles, entitled “Cloning, expression and characterization of the esterase estUT1 from Ureibacillus thermosphaericus which belongs to a new lipase family XVIII”. Since we could not have known of the work of Samoylova et al. [2] when we submitted our manuscript, and in order to avoid confusion in the scientific community, we propose to reclassify LipSm as the first characterized member of the new bacterial lipase family XIX. Therefore throughout our article [1] “lipase family XVIII” should read “lipase family XIX” (title included)
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