997 research outputs found

    Accretion and photodesorption of CO ice as a function of the incident angle of deposition

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    Non-thermal desorption of inter- and circum-stellar ice mantles on dust grains, in particular ultraviolet photon-induced desorption, has gained importance in recent years. These processes may account for the observed gas phase abundances of molecules like CO toward cold interstellar clouds. Ice mantle growth results from gas molecules impinging on the dust from all directions and incidence angles. Nevertheless, the effect of the incident angle for deposition on ice photo-desorption rate has not been studied. This work explores the impact on the accretion and photodesorption rates of the incidence angle of CO gas molecules with the cold surface during deposition of a CO ice layer. Infrared spectroscopy monitored CO ice upon deposition at different angles, ultraviolet-irradiation, and subsequent warm-up. Vacuum-ultraviolet spectroscopy and a Ni-mesh measured the emission of the ultraviolet lamp. Molecules ejected from the ice to the gas during irradiation or warm-up were characterized by a quadrupole mass spectrometer. The photodesorption rate of CO ice deposited at 11 K and different incident angles was rather stable between 0 and 45^{\circ}. A maximum in the CO photodesorption rate appeared around 70^{\circ}-incidence deposition angle. The same deposition angle leads to the maximum surface area of water ice. Although this study of the surface area could not be performed for CO ice, the similar angle dependence in the photodesorption and the ice surface area suggests that they are closely related. Further evidence for a dependence of CO ice morphology on deposition angle is provided by thermal desorption of CO ice experiments

    A parallel-group, multicenter randomized, double-blinded, placebo-controlled, phase 2/3, clinical trial to test the efficacy of pyridostigmine bromide at low doses to reduce mortality or invasive mechanical ventilation in adults with severe SARS-CoV-2 infection: the Pyridostigmine In Severe COvid-19 (PISCO) trial protocol

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    © 2020, The Author(s). Background: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, the causative agent of coronavirus disease 2019 (COVID-19), may lead to severe systemic inflammatory response, pulmonary damage, and even acute respiratory distress syndrome (ARDS). This in turn may result in respiratory failure and in death. Experimentally, acetylcholine (ACh) modulates the acute inflammatory response, a neuro-immune mechanism known as the inflammatory reflex. Recent clinical evidence suggest that electrical and chemical stimulation of the inflammatory reflex may reduce the burden of inflammation in chronic inflammatory diseases. Pyridostigmine (PDG), an ACh-esterase inhibitor (i-ACh-e), increases the half-life of endogenous ACh, therefore mimicking the inflammatory reflex. This clinical trial is aimed at evaluating if add-on of PDG leads to a decrease of invasive mechanical ventilation and death among patients with severe COVID-19. Methods: A parallel-group, multicenter, randomized, double-blinded, placebo-controlled, phase 2/3 clinical trial to test the efficacy of pyridostigmine bromide 60 mg/day P.O. to reduce the need for invasive mechanical ventilation and mortality in hospitalized patients with severe COVID-19. Discussion: This study will provide preliminary evidence of whether or not -by decreasing systemic inflammation- add-on PDG can improve clinical outcomes in patients with severe COVID-19. Trial registration: ClinicalTrials.gov NCT04343963 (registered on April 14, 2020)

    The abundance of C18O and HDO in the envelope and hot core of the intermediate mass protostar NGC 7129 FIRS 2

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    NGC 7129 FIRS 2 is a young intermediate-mass (IM) protostar, which is associated with two energetic bipolar outflows and displays clear signs of the presence of a hot core. It has been extensively observed with ground based telescopes and within the WISH Guaranteed Time Herschel Key Program. We present new observations of the C18O 3-2 and the HDO 3_{12}-2_{21} lines towards NGC 7129 FIRS 2. Combining these observations with Herschel data and modeling their emissions, we constrain the C18O and HDO abundance profiles across the protostellar envelope. In particular, we derive the abundance of C18O and HDO in the hot core. The intensities of the C18O lines are well reproduced assuming that the C18O abundance decreases through the protostellar envelope from the outer edge towards the centre until the point where the gas and dust reach the CO evaporation temperature (~20-25 K) where the C18O is released back to the gas phase. Once the C18O is released to the gas phase, the modelled C18O abundance is found to be ~1.6x10^{-8}, which is a factor of 10 lower than the reference abundance. This result is supported by the non-detection of C18O 9-8, which proves that even in the hot core (T_k>100 K) the CO abundance must be 10 times lower than the reference value. Several scenarios are discussed to explain this C18O deficiency. One possible explanation is that during the pre-stellar and protostellar phase, the CO is removed from the grain mantles by reactions to form more complex molecules. Our HDO modeling shows that the emission of HDO 3_{12}-2_{21} line is maser and comes from the hot core (T_k>100 K). Assuming the physical structure derived by Crimier et al. (2010), we determine a HDO abundance of ~0.4 - 1x10^{-7} in the hot core of this IM protostar, similar to that found in the hot corinos NGC 1333 IRAS 2A and IRAS 16293-2422.Comment: 10 pages, 7 figure

    Persistence of anticancer activity in berry extracts after simulated gastrointestinal digestion and colonic fermentation

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    Fruit and vegetable consumption is associated at the population level with a protective effect against colorectal cancer. Phenolic compounds, especially abundant in berries, are of interest due to their putative anticancer activity. After consumption, however, phenolic compounds are subject to digestive conditions within the gastrointestinal tract that alter their structures and potentially their function. However, the majority of phenolic compounds are not efficiently absorbed in the small intestine and a substantial portion pass into the colon. We characterized berry extracts (raspberries, strawberries, blackcurrants) produced by in vitro-simulated upper intestinal tract digestion and subsequent fecal fermentation. These extracts and selected individual colonic metabolites were then evaluated for their putative anticancer activities using in vitro models of colorectal cancer, representing the key stages of initiation, promotion and invasion. Over a physiologically-relevant dose range (0–50 µg/ml gallic acid equivalents), the digested and fermented extracts demonstrated significant anti-genotoxic, anti-mutagenic and anti-invasive activity on colonocytes. This work indicates that phenolic compounds from berries undergo considerable structural modifications during their passage through the gastrointestinal tract but their breakdown products and metabolites retain biological activity and can modulate cellular processes associated with colon cancer

    Improving quality of care and clinical outcomes for rectal cancer through clinical audits in a multicentre cancer care organisation

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    Introduction: Colorectal cancer treatment requires a complex, multidisciplinary approach. Because of the potential variability, monitoring through clinical audits is advisable. This study assesses the effects of a quality improvement action plan in patients with locally advanced rectal cancer and treated with radiotherapy. Methods: Comparative, multicentre study in two cohorts of 120 patients each, selected randomly from patients diagnosed with rectal cancer who had initiated radiotherapy with a curative intent. Based on the results from a baseline clinical audit in 2013, a quality improvement action plan was designed and implemented; a second audit in 2017 evaluated its impact. Results: Standardised information was present on 77.5% of the magnetic resonance imaging (MRI) staging reports. Treatment strategies were similar in all three study centres. Of the patients whose treatment was interrupted, just 9.7% received a compensation dose. There was an increase in MRI re-staging from 32.5 to 61.5%, and a significant decrease in unreported circumferential resection margins following neoadjuvant therapy (ypCRM), from 34.5 to 5.6% (p < 0.001). Conclusions: The comparison between two clinical audits showed improvements in neoadjuvant radiotherapy in rectal cancer patients. Some indicators reveal areas in need of additional efforts, for example to reduce the overall treatment time

    Transcriptomal profiling of the cellular response to DNA damage mediated by Slug (Snai2)

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    Snai2-deficient cells are radiosensitive to DNA damage. The function of Snai2 in response to DNA damage seems to be critical for its function in normal development and cancer. Here, we applied a functional genomics approach that combined gene-expression profiling and computational molecular network analysis to obtain global dissection of the Snai2-dependent transcriptional response to DNA damage in primary mouse embryonic fibroblasts (MEFs), which undergo p53-dependent growth arrest in response to DNA damage. Although examination of the response showed that overall expression of p53 target gene expression patterns was similarly altered in both control and Snai2-deficient cells, we have identified and validated candidate Snai2 target genes linked to Snai2 gene function in response to DNA damage. This work defines for the first time the effect of Snai2 on p53 target genes in cells undergoing growth arrest, elucidates the Snai2-dependent molecular network induced by DNA damage, points to novel putative Snai2 targets, and suggest a mechanistic model, which has implications for cancer management

    Consensus statement on the diagnosis, management, and treatment of angioedema mediated by Bradykinin. Part. II: treatment, follow-up, and special situations

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    Background: There are no previous Spanish guidelines or consensus statements on bradykinin-induced angioedema. Aim: To draft a consensus statement on the management and treatment of angioedema mediated by bradykinin in light of currently available scientifi c evidence and the experience of experts. This statement will serve as a guideline to health professionals. Methods: The consensus was led by the Spanish Study Group on Bradykinin-Induced Angioedema, a working group of the Spanish Society of Allergology and Clinical Immunology. A review was conducted of scientifi c papers on different types of bradykinin-induced angioedema (hereditary and acquired angioedema due to C1 inhibitor defi ciency, hereditary angioedema related to estrogens, angioedema induced by angiotensin-converting enzyme inhibitors). Several discussion meetings were held to reach the consensus. Results: Treatment approaches are discussed, and the consensus reached is described. Specifi c situations are addressed, namely, pregnancy, contraception, travelling, blood donation, and organ transplantation. Conclusions: A review of and consensus on treatment of bradykinin-induced angioedema is presentedIntroducción: No existen guías previas españolas sobre el manejo del angioedema mediado por bradicinina. Objetivos: Alcanzar un consenso sobre el manejo y tratamiento del angioedema mediado por bradicinina a la luz de la evidencia científi ca disponible y la experiencia de los expertos, que sirva como guía para los profesionales de la salud. Métodos: SGBA/GEAB, un grupo de trabajo de la SEAIC dirigió el consenso. Se realizó una revisión de los documentos científi cos publicados sobre los diferentes tipos de angioedema mediado por bradicinina [angioedema hereditario o adquirido por defi ciencia de inhibidor de la C1 esterasa, angioedema hereditario relacionado con estrógenos (AEH tipo III, AEH-FXII), angioedema inducido por IECA (inhibidores del enzima convertidor de angiotensina]. Hubo varias reuniones del SGBA/GEAB para alcanzar el consenso. Resultados: Se revisan y discuten los diferentes tratamientos disponibles y se describe el consenso alcanzado. Se abordan situaciones específi cas (embarazo, anticoncepción, viajes, hemodonación, trasplante de órganos). Conclusiones: Se presenta una revisión del tratamiento del angioedema mediado por bradicinina y un consenso sobre su tratamiento en EspañaDr. Teresa Caballero is a researcher with the Hospital La Paz Health Research Institute (IdiPaz) program for promoting research activities (2009

    Charge separation relative to the reaction plane in Pb-Pb collisions at sNN=2.76\sqrt{s_{\rm NN}}= 2.76 TeV

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    Measurements of charge dependent azimuthal correlations with the ALICE detector at the LHC are reported for Pb-Pb collisions at sNN=2.76\sqrt{s_{\rm NN}} = 2.76 TeV. Two- and three-particle charge-dependent azimuthal correlations in the pseudo-rapidity range η<0.8|\eta| < 0.8 are presented as a function of the collision centrality, particle separation in pseudo-rapidity, and transverse momentum. A clear signal compatible with a charge-dependent separation relative to the reaction plane is observed, which shows little or no collision energy dependence when compared to measurements at RHIC energies. This provides a new insight for understanding the nature of the charge dependent azimuthal correlations observed at RHIC and LHC energies.Comment: 12 pages, 3 captioned figures, authors from page 2 to 6, published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/286

    A note on comonotonicity and positivity of the control components of decoupled quadratic FBSDE

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    In this small note we are concerned with the solution of Forward-Backward Stochastic Differential Equations (FBSDE) with drivers that grow quadratically in the control component (quadratic growth FBSDE or qgFBSDE). The main theorem is a comparison result that allows comparing componentwise the signs of the control processes of two different qgFBSDE. As a byproduct one obtains conditions that allow establishing the positivity of the control process.Comment: accepted for publicatio
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