21 research outputs found

    Star Formation Feedback and Metal Enrichment History Of The Intergalactic Medium

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    Using hydrodynamic simulations we compute the metal enrichment history of the intergalactic medium (IGM). We show that galactic superwind (GSW) feedback can transport metals to the IGM and that the properties of simulated metal absorbers match observations. The distance of influence of GSW is typically limited to >0.5Mpc and within regions of overdensity >10. Most CIV and OVI absorbers are located within shocked regions of elevated temperature (T>2x10^4K), overdensity (>10), and metallicity ([-2.5,-0.5]). OVI absorbers have typically higher metallicity, lower density and higher temperature than CIV absorbers. For OVI absorbers collisional ionization dominates over the entire redshift range z=0-6, whereas for CIV absorbers the transition occurs at moderate redshift z~3 from collisionally dominated to photoionization dominated. We find that the observed column density distributions for CIV and OVI in the range log N cm^2=12-15 are reasonably reproduced by the simulations. The evolution of mass densities contained in CIV and OVI lines, Omega_CIV and Omega_OVI, is also in good agreement with observations, which shows a near constancy at low redshifts and an exponential drop beyond redshift z=3-4. For both CIV and OVI, most absorbers are transient and the amount of metals probed by CIV and OVI lines of column log N cm^2=12-15 is only ~2% of total metal density at any epoch. While gravitational shocks from large-scale structure formation dominate the energy budget (80-90%) for turning about 50% of IGM to the warm-hot intergalactic medium (WHIM) by z=0, GSW feedback shocks are energetically dominant over gravitational shocks at z > 1-2. Most of the so-called "missing metals" at z=2-3 are hidden in a warm-hot (T=10^{4.5-7}K) gaseous phase, heated up by GSW feedback shocks. Their mass distribution is broadly peaked at δ=110\delta=1-10 in the IGM, outside virialized halos.Comment: 52 pages, 26 figures, published in the Astrophysical Journal, 2011, ApJ, 731, 1

    Energy viability study of Microgrides in non-interconnected areas of the department of Cauca (Colombia)

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    Trabajo de Grado (Profundización)The feasibility of implementing a hybrid renewable energy system as a single microgrid that supplies the energy needs of a region isolated from the conventional network is studied, taking as a case the township of San Isidro in the Municipality of López de Micay located in the Department of Cauca (Colombia).1. INTRODUCTION 2. PROBLEM STATEMENT 3. OBJECTIVES 4. CONCEPTUAL FRAMEWORK 5. THEORETICAL FRAMEWORK 6. STATE OF ART 7. METHODOLOGY FOR SELECTING THE BEST ENERGY SYSTEMS FOR THE ISOLATED MICROGRID 8. APPLICATION OF THE METHODOLOGY 9. RESULTS 10. VALIDATION OF RESULTS 11. DESCRIPTION OF RESULTS 12. CONCLUSIONS AND FUTURE WORK REFERENCES ANNEXESMaestríaMagister en Ingeniería y Gestión de la Innovació

    Visuo‐spatial processing is linked to cortical glutamate dynamics in Parkinson's disease – a 7 Tesla functional MRS study

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    Background and purpose: Cognitive decline is a frequent and debilitating non-motor symptom for patients with Parkinson's disease (PD). Metabolic alterations in the occipital cortex during visual processing may serve as a biomarker for cognitive decline in patients with PD.Methods: Sixteen patients with PD (Unified Parkinson's Disease Rating Scale Part 3, OFF, 38.69 ± 17.25) and 10 age- and sex-matched healthy controls (HC) underwent 7-T functional magnetic resonance spectroscopy (MRS) utilizing a visual checkerboard stimulation. Glutamate metabolite levels during rest versus stimulation were compared. Furthermore, correlates of the functional MRS response with performance in visuo-cognitive tests were investigated.Results: No differences in static MRS between patients with PD and HC were detected, but a dynamic glutamate response was observed in functional MRS in HC upon visual stimulation, which was blunted in patients with PD (F1,22 = 7.13, p = 0.014; η2p= 0.245). A diminished glutamate response correlated with poorer performance in the Benton Judgment of Line Orientation test in PD (r = -0.57, p = 0.020).Conclusions: Our results indicate that functional MRS captures even subtle differences in neural processing linked to the behavioral performance, which would have been missed by conventional, static MRS. Functional MRS thus represents a promising tool for studying molecular alterations at high sensitivity. Its prognostic potential should be evaluated in longitudinal studies, prospectively contributing to earlier diagnosis and individual treatment decisions.Keywords: biomarker; cognitive decline; functional magnetic resonance spectroscopy; visuo-cognition

    Pirtobrutinib (LOXO-305), a Next-Generation, Highly Selective, Non-Covalent Bruton’s Tyrosine Kinase Inhibitor in Previously Treated Mantle Cell Lymphoma and Other Non-Hodgkin Lymphomas: Phase 1/2 BRUIN Study

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    Presentation during EHA2021 : E-Poster Presentation - Session title: Aggressive Non-Hodgkin lymphoma - ClinicalBackgroundDespite the marked efficacy of covalent BTK inhibitors (BTKi) in MCL, WM, and MZL, the development of resistance and discontinuation for adverse events can lead to treatment failure. Moreover, pharmacological liabilities of these agents such as low oral bioavailability or short half-life, can lead to suboptimal BTK target coverage and ultimately result in acquired resistance in some patients (pts). To address these limitations, pirtobrutinib (LOXO-305), a highly selective, non-covalent BTKi that inhibits both WT and C481-mutated BTK with equal low nM potency was developed.AimsTo evaluate safety and efficacy of pirtobrutinib in previously treated MCL and other NHLs.MethodsBRUIN is a multicenter phase 1/2 trial (NCT03740529) enrolling pts with advanced B-cell malignancies who have received >2 prior therapies. Oral pirtobrutinib was dose escalated in a standard 3+3 design in 28-day cycles. The primary endpoint was MTD/RP2D identification. Efficacy evaluable pts included all dosed pts who underwent their first response evaluation or discontinued therapy. Safety was assessed in all pts (n=323). Response was assessed according to Lugano Classification or iWWM. ResultsAs of 27 September 2020, 323 pts with B-cell malignancies (170 CLL/SLL, 61 MCL, 26 WM, and 66 other B-cell lymphomas) were treated on 7 dose levels (25-300mg QD). Median age was 69 (range 50-87) years for MCL pts, 68 (42-84) for WM pts, and 68 (27-86) for other NHLs pts. Median number of prior lines of therapy was 3 (range, 1-8) for MCL, 3 (2-11) for WM, and 4 (2-10) for other NHLs. 93% of MCL, 70% of WM and 36% other NHL pts had received a prior BTKi. Pirtobrutinib demonstrated high oral exposures, with doses ≥100mg QD exceeding the BTK IC90 for the entirety of the dosing interval. No DLTs occurred. Consistent with pirtobrutinib’s selectivity, the only treatment emergent adverse events regardless of attribution or grade in >10% of pts (n=323) were fatigue (20%), diarrhea (17%) and contusion (13%). Grade 3 atrial fibrillation/flutter was not observed; 1 pt had grade 3 hemorrhage in the setting of mechanical trauma. Responses were observed at the first dose level of 25mg QD. A RP2D of 200mg QD was selected. At the efficacy cutoff date, 35 (57%) MCL pts, 18 (69%) WM pts and 34 (52%) other NHL pts remained on therapy. Among the 52 efficacy evaluable prior BTKi treated MCL pts, the ORR was 52% with 13 CR, 14 PR and 9 SD. Median follow up was 6 months (range 0.7-18.3+) for MCL. Responses in MCL were observed in 9/14 pts (64%) with prior autologous or allogeneic transplant, and 2 of 2 with prior CAR-T cell therapy. Among the 19 efficacy-evaluable pts with WM, the ORR was 68% (9 PR, 4 MR, 3 SD), and 69% in prior BTKi treated pts. 10 of 13 WM responders were ongoing (follow-up time from initial response: 0.8-9.2 months). For the 55 efficacy-evaluable other NHL pts, best response was as follows: DLBCL - 24% ORR (4 CR, 2 PR, 2 SD, 12 PD, 5 NE), FL - 50% ORR (2 CR, 2 PR, 1 SD, 3 PD), MZL - 22% ORR (2 PR, 7 SD), Richter’s transformation - 75% ORR (6 PR, 1 SD, 1 NE) and Other (2 B-PLL, 3 Low grade transformation) 1 SD, 2 PD, 2 NE.ConclusionPirtobrutinib demonstrated promising efficacy in MCL pts following multiple prior lines of therapy, including a covalent BTKi. Pirtobrutinib also showed efficacy in previously treated other NHLs. Pirtobrutinib was well tolerated and exhibited a wide therapeutic index
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