225 research outputs found

    Standardisation of intestinal ultrasound scoring in clinical trials for luminal Crohn's disease

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    Background: Intestinal ultrasound (IUS) is a valuable tool for assessment of Crohn’s disease (CD). However, there is no widely accepted luminal disease activity index. / Aims: To identify appropriate IUS protocols, indices, items, and scoring methods for measurement of luminal CD activity and integration of IUS in CD clinical trials. / Methods: An expert international panel of adult and paediatric gastroenterologists (n = 15) and radiologists (n = 3) rated the appropriateness of 120 statements derived from literature review and expert opinion (scale of 1-9) using modified RAND/UCLA methodology. Median panel scores of 1 to ≤3.5, >3.5 to <6.5 and ≥6.5 to 9 were considered inappropriate, uncertain and appropriate ratings respectively. The statement list and survey results were discussed prior to voting. / Results: A total of 91 statements were rated appropriate with agreement after two rounds of voting. Items considered appropriate measures of disease activity were bowel wall thickness (BWT), vascularity, stratification and mesenteric inflammatory fat. There was uncertainty if any of the existing IUS disease activity indices were appropriate for use in CD clinical trials. Appropriate trial applications for IUS included patient recruitment qualification when diseased segments cannot be adequately assessed by ileocolonoscopy and screening for exclusionary complications. At outcome assessment, remission endpoints including BWT and vascularity, with or without mesenteric inflammatory fat, were considered appropriate. Components of an ideal IUS disease activity index were identified based upon panel discussions. / Conclusions: The panel identified appropriate component items and applications of IUS for CD clinical trials. Empiric evidence, and development and validation of an IUS disease activity index are needed

    Direct-acting antivirals are effective and safe in HCV/HIV-coinfected liver transplant recipients who experience recurrence of hepatitis C: A prospective nationwide cohort study.

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    Direct-acting antivirals have proved to be highly efficacious and safe in monoinfected liver transplant (LT) recipients who experience recurrence of hepatitis C virus (HCV) infection. However, there is a lack of data on effectiveness and tolerability of these regimens in HCV/HIV-coinfected patients who experience recurrence of HCV infection after LT. In this prospective, multicenter cohort study, the outcomes of 47 HCV/HIV-coinfected LT patients who received DAA therapy (with or without ribavirin [RBV]) were compared with those of a matched cohort of 148 HCV-monoinfected LT recipients who received similar treatment. Baseline characteristics were similar in both groups. HCV/HIV-coinfected patients had a median (IQR) CD4 T-cell count of 366 (256-467) cells/µL. HIV-RNA was <50 copies/mL in 96% of patients. The DAA regimens administered were SOF + LDV ± RBV (34%), SOF + SMV ± RBV (31%), SOF + DCV ± RBV (27%), SMV + DCV ± RBV (5%), and 3D (3%), with no differences between the groups. Treatment was well tolerated in both groups. Rates of SVR (negative serum HCV-RNA at 12 weeks after the end of treatment) were high and similar for coinfected and monoinfected patients (95% and 94%, respectively; P = .239). Albeit not significant, a trend toward lower SVR rates among patients with advanced fibrosis (P = .093) and genotype 4 (P = .088) was observed. In conclusion, interferon-free regimens with DAAs for post-LT recurrence of HCV infection in HIV-infected individuals were highly effective and well tolerated, with results comparable to those of HCV-monoinfected patients

    Effect of metal Ions (Ni2+, Cu2+ and Zn2+) and water coordination on the structure of L-phenylalanine, L-tyrosine, L-tryptophan and their zwitterionic forms

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    Methods of quantum chemistry have been applied to double-charged complexes involving the transition metals Ni2+, Cu2+ and Zn2+ with the aromatic amino acids (AAA) phenylalanine, tyrosine and tryptophan. The effect of hydration on the relative stability and geometry of the individual species studied has been evaluated within the supermolecule approach. The interaction enthalpies, entropies and Gibbs energies of nine complexes Phe•M, Tyr•M, Trp•M, (M = Ni2+, Cu2+ and Zn2+) were determined at the Becke3LYP density functional level of theory. Of the transition metals studied the bivalent copper cation forms the strongest complexes with AAAs. For Ni2+and Cu2+ the most stable species are the NO coordinated cations in the AAA metal complexes, Zn2+cation prefers a binding to the aromatic part of the AAA (complex II). Some complexes energetically unfavored in the gas-phase are stabilized upon microsolvation

    Grain Surface Models and Data for Astrochemistry

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    AbstractThe cross-disciplinary field of astrochemistry exists to understand the formation, destruction, and survival of molecules in astrophysical environments. Molecules in space are synthesized via a large variety of gas-phase reactions, and reactions on dust-grain surfaces, where the surface acts as a catalyst. A broad consensus has been reached in the astrochemistry community on how to suitably treat gas-phase processes in models, and also on how to present the necessary reaction data in databases; however, no such consensus has yet been reached for grain-surface processes. A team of ∼25 experts covering observational, laboratory and theoretical (astro)chemistry met in summer of 2014 at the Lorentz Center in Leiden with the aim to provide solutions for this problem and to review the current state-of-the-art of grain surface models, both in terms of technical implementation into models as well as the most up-to-date information available from experiments and chemical computations. This review builds on the results of this workshop and gives an outlook for future directions

    Seeds of Life in Space (SOLIS) VI. Chemical evolution of sulfuretted species along the outflows driven by the low-mass protostellar binary NGC1333-IRAS4A

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    Context: Low-mass protostars drive powerful molecular outflows that can be observed with millimetre and submillimetre telescopes. Various sulfuretted species are known to be bright in shocks and could be used to infer the physical and chemical conditions throughout the observed outflows. Aims: The evolution of sulfur chemistry is studied along the outflows driven by the NGC 1333-IRAS4A protobinary system located in the Perseus cloud to constrain the physical and chemical processes at work in shocks. Methods: We observed various transitions from OCS, CS, SO, and SO2 towards NGC 1333-IRAS4A in the 1.3, 2, and 3 mm bands using the IRAM NOrthern Extended Millimeter Array and we interpreted the observations through the use of the Paris-Durham shock model. Results: The targeted species clearly show different spatial emission along the two outflows driven by IRAS4A. OCS is brighter on small and large scales along the south outflow driven by IRAS4A1, whereas SO2 is detected rather along the outflow driven by IRAS4A2 that is extended along the north east–south west direction. SO is detected at extremely high radial velocity up to +25 km s−1 relative to the source velocity, clearly allowing us to distinguish the two outflows on small scales. Column density ratio maps estimated from a rotational diagram analysis allowed us to confirm a clear gradient of the OCS/SO2 column density ratio between the IRAS4A1 and IRAS4A2 outflows. Analysis assuming non Local Thermodynamic Equilibrium of four SO2 transitions towards several SiO emission peaks suggests that the observed gas should be associated with densities higher than 105 cm−3 and relatively warm (T > 100 K) temperatures in most cases. Conclusions: The observed chemical differentiation between the two outflows of the IRAS4A system could be explained by a different chemical history. The outflow driven by IRAS4A1 is likely younger and more enriched in species initially formed in interstellar ices, such as OCS, and recently sputtered into the shock gas. In contrast, the longer and likely older outflow triggered by IRAS4A2 is more enriched in species that have a gas phase origin, such as SO2

    Seeds of Life in Space (SOLIS). III. Zooming Into the Methanol Peak of the Prestellar Core L1544

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    Toward the prestellar core L1544, the methanol (CH3OH) emission forms an asymmetric ring around the core center, where CH3OH is mostly in solid form, with a clear peak at 4000 au to the northeast of the dust continuum peak. As part of the NOEMA Large Project SOLIS (Seeds of Life in Space), the CH3OH peak has been spatially resolved to study its kinematics and physical structure and to investigate the cause behind the local enhancement. We find that methanol emission is distributed in a ridge parallel to the main axis of the dense core. The centroid velocity increases by about 0.2 km s−1 and the velocity dispersion increases from subsonic to transonic toward the central zone of the core, where the velocity field also shows complex structure. This could be an indication of gentle accretion of material onto the core or the interaction of two filaments, producing a slow shock. We measure the rotational temperature and show that methanol is in local thermodynamic equilibrium (LTE) only close to the dust peak, where it is significantly depleted. The CH3OH column density, N tot(CH3OH), profile has been derived with non-LTE radiative transfer modeling and compared with chemical models of a static core. The measured N tot(CH3OH) profile is consistent with model predictions, but the total column densities are one order of magnitude lower than those predicted by models, suggesting that the efficiency of reactive desorption or atomic hydrogen tunneling adopted in the model may be overestimated; or that an evolutionary model is needed to better reproduce methanol abundance
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