62 research outputs found

    Numerical heat conduction in hydrodynamical models of colliding hypersonic flows

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    Hydrodynamical models of colliding hypersonic flows are presented which explore the dependence of the resulting dynamics and the characteristics of the derived X-ray emission on numerical conduction and viscosity. For the purpose of our investigation we present models of colliding flow with plane-parallel and cylindrical divergence. Numerical conduction causes erroneous heating of gas across the contact discontinuity which has implications for the rate at which the gas cools. We find that the dynamics of the shocked gas and the resulting X-ray emission are strongly dependent on the contrast in the density and temperature either side of the contact discontinuity, these effects being strongest where the postshock gas of one flow behaves quasi-adiabatically while the postshock gas of the other flow is strongly radiative. Introducing additional numerical viscosity into the simulations has the effect of damping the growth of instabilities, which in some cases act to increase the volume of shocked gas and can re-heat gas via sub-shocks as it flows downstream. The resulting reduction in the surface area between adjacent flows, and therefore of the amount of numerical conduction, leads to a commensurate reduction in spurious X-ray emission, though the dynamics of the collision are compromised. The simulation resolution also affects the degree of numerical conduction. A finer resolution better resolves the interfaces of high density and temperature contrast and although numerical conduction still exists the volume of affected gas is considerably reduced. However, since it is not always practical to increase the resolution, it is imperative that the degree of numerical conduction is understood so that inaccurate interpretations can be avoided. This work has implications for the dynamics and emission from astrophysical phenomena which involve high Mach number shocks.Comment: 14 pages, 10 figures, accepted for publication in MNRA

    A 3-biomarker 2-point-based risk stratification strategy in acute heart failure

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    [Abstract] Introduction and Objectives: Most multi-biomarker strategies in acute heart failure (HF) have only measured biomarkers in a single-point time. This study aimed to evaluate the prognostic yielding of NT-proBNP, hsTnT, Cys-C, hs-CRP, GDF15, and GAL-3 in HF patients both at admission and discharge. Methods: We included 830 patients enrolled consecutively in a prospective multicenter registry. Primary outcome was 12-month mortality. The gain in the C-index, calibration, net reclassification improvement (NRI), and integrated discrimination improvement (IDI) was calculated after adding each individual biomarker value or their combination on top of the best clinical model developed in this study (C-index 0.752, 0.715–0.789) and also on top of 4 currently used scores (MAGGIC, GWTG-HF, Redin-SCORE, BCN-bioHF). Results: After 12-month, death occurred in 154 (18.5%) cases. On top of the best clinical model, the addition of NT-proBNP, hs-CRP, and GDF-15 above the respective cutoff point at admission and discharge and their delta during compensation improved the C-index to 0.782 (0.747–0.817), IDI by 5% (p < 0.001), and NRI by 57% (p < 0.001) for 12-month mortality. A 4-risk grading categories for 12-month mortality (11.7, 19.2, 26.7, and 39.4%, respectively; p < 0.001) were obtained using combination of these biomarkers. Conclusion: A model including NT-proBNP, hs-CRP, and GDF-15 measured at admission and discharge afforded a mortality risk prediction greater than our clinical model and also better than the most currently used scores. In addition, this 3-biomarker panel defined 4-risk categories for 12-month mortality.Instituto de Salud Carlos III; RD06-0003-0000Instituto de Salud Carlos III; RD12/0042/000

    A 3-Biomarker 2-Point-Based Risk Stratification Strategy in Acute Heart Failure

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    Altres ajuts: ISCIII/RD06-0003-0000Altres ajuts: ISCIII/RD12/0042/0002Introduction and Objectives: Most multi-biomarker strategies in acute heart failure (HF) have only measured biomarkers in a single-point time. This study aimed to evaluate the prognostic yielding of NT-proBNP, hsTnT, Cys-C, hs-CRP, GDF15, and GAL-3 in HF patients both at admission and discharge. Methods: We included 830 patients enrolled consecutively in a prospective multicenter registry. Primary outcome was 12-month mortality. The gain in the C-index, calibration, net reclassification improvement (NRI), and integrated discrimination improvement (IDI) was calculated after adding each individual biomarker value or their combination on top of the best clinical model developed in this study (C-index 0.752, 0.715-0.789) and also on top of 4 currently used scores (MAGGIC, GWTG-HF, Redin-SCORE, BCN-bioHF). Results: After 12-month, death occurred in 154 (18.5%) cases. On top of the best clinical model, the addition of NT-proBNP, hs-CRP, and GDF-15 above the respective cutoff point at admission and discharge and their delta during compensation improved the C-index to 0.782 (0.747-0.817), IDI by 5% (p < 0.001), and NRI by 57% (p < 0.001) for 12-month mortality. A 4-risk grading categories for 12-month mortality (11.7, 19.2, 26.7, and 39.4%, respectively; p < 0.001) were obtained using combination of these biomarkers. Conclusion: A model including NT-proBNP, hs-CRP, and GDF-15 measured at admission and discharge afforded a mortality risk prediction greater than our clinical model and also better than the most currently used scores. In addition, this 3-biomarker panel defined 4-risk categories for 12-month mortality

    A simple validated method for predicting the risk of hospitalization for worsening of heart failure in ambulatory patients : the Redin-SCORE

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    Prevention of hospital readmissions is one of the main objectives in the management of patients with heart failure (). Most of the models predicting readmissions are based on data extracted from hospitalized patients rather than from outpatients. Our objective was to develop a validated score predicting 1-month and 1-year risk of readmission for worsening of in ambulatory patients. A cohort of 2507 ambulatory patients with chronic was prospectively followed for a median of 3.3 years. Clinical, echocardiographic, , and biochemical variables were used in a competing risk regression analysis to construct a risk score for readmissions due to worsening of . Thereafter, the score was externally validated using a different cohort of 992 patients with chronic ( registry). Predictors of 1-month readmission were the presence of elevated natriuretic peptides, left ventricular (LV) HF signs, and estimated glomerular filtration rate () 26 mm/m 2, heart rate >70 b.p.m., signs, and 5% event rate) for 1-month readmission. Likewise, low-risk (7.8%), intermediate-risk (15.6%) and high-risk groups (26.1%) were identified for 1-year readmission risk. The C-statistics remained consistent after the external validation (<5% loss of discrimination). The Redin- predicts early and late readmission for worsening of using proven prognostic variables that are routinely collected in outpatient management of chronic

    Counteranion-Dependent Reaction Pathways in the Protonation of Cationic Ruthenium−Vinylidene Complexes

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    The tetraphenylborate salts of the cationic vinylidene complexes [Cp*Ru=C=CHR(iPr2PNHPy)]+ (R = p-C6H4CF3 (1a-BPh4), Ph (1b-BPh4), p-C6H4CH3 (1c- BPh4), p-C6H4Br (1d-BPh4), tBu (1e-BPh4), H (1f-BPh4)) have been protonated using an excess of HBF4·OEt2 in CD2Cl2, furnishing the dicationic carbyne complexes [Cp*Ru≡CCH2R(iPr2PNHPy)]2+ (R = p-C6H4CF3 (2a), Ph (2b), p-C6H4CH3 (2c), p-C6H4Br (2d), tBu (2e), H (2f)), which were characterized in solution at low temperature by NMR spectroscopy. The corresponding reaction of the chloride salts 1a-Cl, 1b-Cl, 1c-Cl, and 1d-Cl followed a different pathway, instead affording the novel alkene complexes [Cp*RuCl(κ1(N),η2(C,C)-C5H4N-NHPiPr2CH=CHR)][BF4] (3a−d). In these species, the entering proton is located at the α- carbon atom of the former vinylidene ligand, which also forms a P−C bond with the phosphorus atom of the iPr2PNHPy ligand. To shed light on the reaction mechanism, DFT calculations have been performed by considering several protonation sites. The computational results suggest metal protonation followed by insertion. The coordination of chloride to ruthenium leads to alkenyl species which can undergo a P−C coupling to yield the corresponding alkene complexes. The noncoordinating nature of [BPh4]− does not allow the stabilization of the unsaturated species coming from the insertion step, thus preventing this alternative pathway

    Exploring Health Science Students’ Notions on Organ Donation and Transplantation: A Multicenter Study

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    The knowledge acquired during university education about organ donation and transplantation (ODT) decisively influences the information future health professionals transmit. This is important in ODT where the participation of the general public is essential to obtain organs. Objective: To determine notions of Spanish medicine and nursing students on ODT and its relationship with attitude toward ODT. Methods and Design: and design. We conducted a sociologic, multicenter, and observational study. The population for our study consisted of medical and nursing students in Spanish universities. Our database was the Collaborative International Donor Project, stratified by geographic area and academic course. A validated questionnaire (PCID-DTO-RIOS) was self-administered and completed anonymously. Our sample consisted of 9598 medical and 10, 566 nursing students (99% confidence interval; precision of ±1%), stratified by geographic area and year of study. Results: The completion rate for our study was 90%. Only 20% (n=3640) of students thought their notions on ODT were good; 41% (n=7531) thought their notions were normal; 36% (n=6550) thought their notions were scarce. Comparing groups, there were differences between those who believed that their notions on ODT were good (44% nursing vs 56% medical students; P < .000), and those who believed it scarce (54% nursing vs 46% medical students; P < .000). Notions on ODT were related with attitude toward the donation of one''s own organs: those who considered their notions were good were more in favor then those who considered it scarce (88% vs 72%; P < .000). Conclusion: Only 20% of Spanish medical and nursing students thought their notions on ODT were good. Having good knowledge is related to a favorable attitude towards ODT. Receiving specific information on the subject could improve their knowledge about ODT during their training

    Array-CGH in patients with Kabuki-like phenotype: Identification of two patients with complex rearrangements including 2q37 deletions and no other recurrent aberration

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    Background: Kabuki syndrome (KS) is a multiple congenital anomaly syndrome characterized by specific facial features, mild to moderate mental retardation, postnatal growth delay, skeletal abnormalities, and unusual dermatoglyphic patterns with prominent fingertip pads. A 3.5 Mb duplication at 8p23.1-p22 was once reported as a specific alteration in KS but has not been confirmed in other patients. The molecular basis of KS remains unknown. Methods: We have studied 16 Spanish patients with a clinical diagnosis of KS or KS-like to search for genomic imbalances using genome-wide array technologies. All putative rearrangements were confirmed by FISH, microsatellite markers and/or MLPA assays, which also determined whether the imbalance was de novo or inherited. Results: No duplication at 8p23.1-p22 was observed in our patients. We detected complex rearrangements involving 2q in two patients with Kabuki-like features: 1) a de novo inverted duplication of 11 Mb with a 4.5 Mb terminal deletion, and 2) a de novo 7.2 Mb-terminal deletion in a patient with an additional de novo 0.5 Mb interstitial deletion in 16p. Additional copy number variations (CNV), either inherited or reported in normal controls, were identified and interpreted as polymorphic variants. No specific CNV was significantly increased in the KS group. Conclusion: Our results further confirmed that genomic duplications of 8p23 region are not a common cause of KS and failed to detect other recurrent rearrangement causing this disorder. The detection of two patients with 2q37 deletions suggests that there is a phenotypic overlap between the two conditions, and screening this region in the Kabuki-like patients should be considered.This work was funded by grants from the Spanish Ministry of Health (FIS PI042063), Genome Spain and the European Commission (FP6-2005-037627). IC was supported by a Juan de la Cierva Postdoctoral fellowship

    Deep-sequencing reveals broad subtype-specific HCV resistance mutations associated with treatment failure

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    A percentage of hepatitis C virus (HCV)-infected patients fail direct acting antiviral (DAA)-based treatment regimens, often because of drug resistance-associated substitutions (RAS). The aim of this study was to characterize the resistance profile of a large cohort of patients failing DAA-based treatments, and investigate the relationship between HCV subtype and failure, as an aid to optimizing management of these patients. A new, standardized HCV-RAS testing protocol based on deep sequencing was designed and applied to 220 previously subtyped samples from patients failing DAA treatment, collected in 39 Spanish hospitals. The majority had received DAA-based interferon (IFN) a-free regimens; 79% had failed sofosbuvir-containing therapy. Genomic regions encoding the nonstructural protein (NS) 3, NS5A, and NS5B (DAA target regions) were analyzed using subtype-specific primers. Viral subtype distribution was as follows: genotype (G) 1, 62.7%; G3a, 21.4%; G4d, 12.3%; G2, 1.8%; and mixed infections 1.8%. Overall, 88.6% of patients carried at least 1 RAS, and 19% carried RAS at frequencies below 20% in the mutant spectrum. There were no differences in RAS selection between treatments with and without ribavirin. Regardless of the treatment received, each HCV subtype showed specific types of RAS. Of note, no RAS were detected in the target proteins of 18.6% of patients failing treatment, and 30.4% of patients had RAS in proteins that were not targets of the inhibitors they received. HCV patients failing DAA therapy showed a high diversity of RAS. Ribavirin use did not influence the type or number of RAS at failure. The subtype-specific pattern of RAS emergence underscores the importance of accurate HCV subtyping. The frequency of “extra-target” RAS suggests the need for RAS screening in all three DAA target regions

    Gaia Focused Product Release: Radial velocity time series of long-period variables

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    The third Gaia Data Release (DR3) provided photometric time series of more than 2 million long-period variable (LPV) candidates. Anticipating the publication of full radial-velocity (RV) in DR4, this Focused Product Release (FPR) provides RV time series for a selection of LPVs with high-quality observations. We describe the production and content of the Gaia catalog of LPV RV time series, and the methods used to compute variability parameters published in the Gaia FPR. Starting from the DR3 LPVs catalog, we applied filters to construct a sample of sources with high-quality RV measurements. We modeled their RV and photometric time series to derive their periods and amplitudes, and further refined the sample by requiring compatibility between the RV period and at least one of the GG, GBPG_{\rm BP}, or GRPG_{\rm RP} photometric periods. The catalog includes RV time series and variability parameters for 9\,614 sources in the magnitude range 6G/mag146\lesssim G/{\rm mag}\lesssim 14, including a flagged top-quality subsample of 6\,093 stars whose RV periods are fully compatible with the values derived from the GG, GBPG_{\rm BP}, and GRPG_{\rm RP} photometric time series. The RV time series contain a mean of 24 measurements per source taken unevenly over a duration of about three years. We identify the great most sources (88%) as genuine LPVs, with about half of them showing a pulsation period and the other half displaying a long secondary period. The remaining 12% consists of candidate ellipsoidal binaries. Quality checks against RVs available in the literature show excellent agreement. We provide illustrative examples and cautionary remarks. The publication of RV time series for almost 10\,000 LPVs constitutes, by far, the largest such database available to date in the literature. The availability of simultaneous photometric measurements gives a unique added value to the Gaia catalog (abridged)Comment: 36 pages, 38 figure

    Cuerpos y prácticas: una década de estudios ctg

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    Resumen En este trabajo presentamos algunas investigaciones realizadas en el área de estudios sociales de la ciencia bajo el enfoque denominado Ciencia, Tecnología y Género (CTG). La intersección de los estudios sociales de la ciencia con la teoría feminista y los estudios de género ha dado lugar a este campo de estudio interdisciplinar. En el Estado español, se han llevado a cabo múltiples trabajos en esta línea, de los que exponemos algunos de los realizados por nuestro grupo de investigación al menos en los últimos diez años. Se centran en estudios de caso, que implican diferentes tecnologías biomédicas, y en los que los cuerpos juegan un papel fundamental estableciendo alianzas, resistencias o cuestionando los marcos normativos en los que cuerpos y tecnologías se hayan inmersos
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