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1.
Phys Rev Lett ; 130(5): 051802, 2023 Feb 03.
Artículo en Inglés | MEDLINE | ID: mdl-36800478

RESUMEN

The inclusive electron neutrino charged-current cross section is measured in the NOvA near detector using 8.02×10^{20} protons-on-target in the NuMI beam. The sample of GeV electron neutrino interactions is the largest analyzed to date and is limited by ≃17% systematic rather than the ≃7.4% statistical uncertainties. The double-differential cross section in final-state electron energy and angle is presented for the first time, together with the single-differential dependence on Q^{2} (squared four-momentum transfer) and energy, in the range 1 GeV≤E_{ν}<6 GeV. Detailed comparisons are made to the predictions of the GENIE, GiBUU, NEUT, and NuWro neutrino event generators. The data do not strongly favor a model over the others consistently across all three cross sections measured, though some models have especially good or poor agreement in the single differential cross section vs Q^{2}.

2.
Science ; 376(6588): 40, 2022 04.
Artículo en Inglés | MEDLINE | ID: mdl-35357942

RESUMEN

A new documentary capably navigates the life and legacy of Benjamin Franklin.

3.
Phys Rev Lett ; 127(20): 201801, 2021 Nov 12.
Artículo en Inglés | MEDLINE | ID: mdl-34860065

RESUMEN

This Letter reports results from the first long-baseline search for sterile antineutrinos mixing in an accelerator-based antineutrino-dominated beam. The rate of neutral-current interactions in the two NOvA detectors, at distances of 1 and 810 km from the beam source, is analyzed using an exposure of 12.51×10^{20} protons-on-target from the NuMI beam at Fermilab running in antineutrino mode. A total of 121 of neutral-current candidates are observed at the far detector, compared to a prediction of 122±11(stat.)±15(syst.) assuming mixing only between three active flavors. No evidence for ν[over ¯]_{µ}→ν[over ¯]_{s} oscillation is observed. Interpreting this result within a 3+1 model, constraints are placed on the mixing angles θ_{24}<25° and θ_{34}<32° at the 90% C.L. for 0.05 eV^{2}≤Δm_{41}^{2}≤0.5 eV^{2}, the range of mass splittings that produces no significant oscillations at the near detector. These are the first 3+1 confidence limits set using long-baseline accelerator antineutrinos.

4.
Phys Rev Lett ; 123(15): 151803, 2019 Oct 11.
Artículo en Inglés | MEDLINE | ID: mdl-31702305

RESUMEN

The NOvA experiment has seen a 4.4σ signal of ν[over ¯]_{e} appearance in a 2 GeV ν[over ¯]_{µ} beam at a distance of 810 km. Using 12.33×10^{20} protons on target delivered to the Fermilab NuMI neutrino beamline, the experiment recorded 27 ν[over ¯]_{µ}→ν[over ¯]_{e} candidates with a background of 10.3 and 102 ν[over ¯]_{µ}→ν[over ¯]_{µ} candidates. This new antineutrino data are combined with neutrino data to measure the parameters |Δm_{32}^{2}|=2.48_{-0.06}^{+0.11}×10^{-3} eV^{2}/c^{4} and sin^{2}θ_{23} in the ranges from (0.53-0.60) and (0.45-0.48) in the normal neutrino mass hierarchy. The data exclude most values near δ_{CP}=π/2 for the inverted mass hierarchy by more than 3σ and favor the normal neutrino mass hierarchy by 1.9σ and θ_{23} values in the upper octant by 1.6σ.

5.
Br Dent J ; 226(9): 635, 2019 05.
Artículo en Inglés | MEDLINE | ID: mdl-31076674
6.
Science ; 358(6370): 1574-1578, 2017 12 22.
Artículo en Inglés | MEDLINE | ID: mdl-29038374

RESUMEN

On 17 August 2017, Swope Supernova Survey 2017a (SSS17a) was discovered as the optical counterpart of the binary neutron star gravitational wave event GW170817. We report time-series spectroscopy of SSS17a from 11.75 hours until 8.5 days after the merger. Over the first hour of observations, the ejecta rapidly expanded and cooled. Applying blackbody fits to the spectra, we measured the photosphere cooling from [Formula: see text] to [Formula: see text] kelvin, and determined a photospheric velocity of roughly 30% of the speed of light. The spectra of SSS17a began displaying broad features after 1.46 days and evolved qualitatively over each subsequent day, with distinct blue (early-time) and red (late-time) components. The late-time component is consistent with theoretical models of r-process-enriched neutron star ejecta, whereas the blue component requires high-velocity, lanthanide-free material.

7.
Science ; 358(6370): 1570-1574, 2017 12 22.
Artículo en Inglés | MEDLINE | ID: mdl-29038375

RESUMEN

On 17 August 2017, gravitational waves (GWs) were detected from a binary neutron star merger, GW170817, along with a coincident short gamma-ray burst, GRB 170817A. An optical transient source, Swope Supernova Survey 17a (SSS17a), was subsequently identified as the counterpart of this event. We present ultraviolet, optical, and infrared light curves of SSS17a extending from 10.9 hours to 18 days postmerger. We constrain the radioactively powered transient resulting from the ejection of neutron-rich material. The fast rise of the light curves, subsequent decay, and rapid color evolution are consistent with multiple ejecta components of differing lanthanide abundance. The late-time light curve indicates that SSS17a produced at least ~0.05 solar masses of heavy elements, demonstrating that neutron star mergers play a role in rapid neutron capture (r-process) nucleosynthesis in the universe.

8.
Phys Rev Lett ; 118(23): 231801, 2017 Jun 09.
Artículo en Inglés | MEDLINE | ID: mdl-28644674

RESUMEN

Results are reported from an improved measurement of ν_{µ}→ν_{e} transitions by the NOvA experiment. Using an exposure equivalent to 6.05×10^{20} protons on target, 33 ν_{e} candidates are observed with a background of 8.2±0.8 (syst.). Combined with the latest NOvA ν_{µ} disappearance data and external constraints from reactor experiments on sin^{2}2θ_{13}, the hypothesis of inverted mass hierarchy with θ_{23} in the lower octant is disfavored at greater than 93% C.L. for all values of δ_{CP}.

9.
Phys Rev Lett ; 118(15): 151802, 2017 Apr 14.
Artículo en Inglés | MEDLINE | ID: mdl-28452513

RESUMEN

This Letter reports new results on muon neutrino disappearance from NOvA, using a 14 kton detector equivalent exposure of 6.05×10^{20} protons on target from the NuMI beam at the Fermi National Accelerator Laboratory. The measurement probes the muon-tau symmetry hypothesis that requires maximal θ_{23} mixing (θ_{23}=π/4). Assuming the normal mass hierarchy, we find Δm_{32}^{2}=(2.67±0.11)×10^{-3} eV^{2} and sin^{2}θ_{23} at the two statistically degenerate values 0.404_{-0.022}^{+0.030} and 0.624_{-0.030}^{+0.022}, both at the 68% confidence level. Our data disfavor the maximal mixing scenario with 2.6σ significance.

10.
Int J Stroke ; 12(1): 9-12, 2017 01.
Artículo en Inglés | MEDLINE | ID: mdl-27694315

RESUMEN

Systemic thrombolysis with rt-PA is contraindicated in patients with acute ischemic stroke anticoagulated with dabigatran. This expert opinion provides guidance on the use of the specific reversal agent idarucizumab followed by rt-PA and/or thrombectomy in patients with ischemic stroke pre-treated with dabigatran. The use of idarucizumab followed by rt-PA is covered by the label of both drugs.


Asunto(s)
Antitrombinas/uso terapéutico , Isquemia Encefálica/terapia , Dabigatrán/uso terapéutico , Accidente Cerebrovascular/terapia , Trombectomía , Terapia Trombolítica , Isquemia Encefálica/prevención & control , Humanos , Accidente Cerebrovascular/prevención & control
11.
Phys Rev Lett ; 116(15): 151806, 2016 04 15.
Artículo en Inglés | MEDLINE | ID: mdl-27127961

RESUMEN

We report results from the first search for ν_{µ}→ν_{e} transitions by the NOvA experiment. In an exposure equivalent to 2.74×10^{20} protons on target in the upgraded NuMI beam at Fermilab, we observe 6 events in the Far Detector, compared to a background expectation of 0.99±0.11(syst) events based on the Near Detector measurement. A secondary analysis observes 11 events with a background of 1.07±0.14(syst). The 3.3σ excess of events observed in the primary analysis disfavors 0.1π<δ_{CP}<0.5π in the inverted mass hierarchy at the 90% C.L.

12.
Neurocrit Care ; 24(1): 82-9, 2016 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-26156112

RESUMEN

BACKGROUND: The ability to predict outcomes in acutely comatose cardiac arrest survivors is limited. Brain diffusion-weighted magnetic resonance imaging (DWI MRI) has been shown in initial studies to be a simple and effective prognostic tool. This study aimed to determine the predictive value of previously defined DWI MRI thresholds in a multi-center cohort. METHODS: DWI MRIs of comatose post-cardiac arrest patients were analyzed in this multi-center retrospective observational study. Poor outcome was defined as failure to regain consciousness within 14 days and/or death during the hospitalization. The apparent diffusion coefficient (ADC) value of each brain voxel was determined. ADC thresholds and brain volumes below each threshold were analyzed for their correlation with outcome. RESULTS: 125 patients were included in the analysis. 33 patients (26%) had a good outcome. An ADC value of less than 650 × 10(-6) mm(2)/s in ≥10% of brain volume was highly specific [91% (95% CI 75-98)] and had a good sensitivity [72% (95% CI 61-80)] for predicting poor outcome. This threshold remained an independent predictor of poor outcome in multivariable analysis (p = 0.002). An ADC value of less than 650 × 10(-6) mm(2)/s in >22% of brain volume was needed to achieve 100% specificity for poor outcome. CONCLUSIONS: In patients who remain comatose after cardiac arrest, quantitative DWI MRI findings correlate with early recovery of consciousness. A DWI MRI threshold of 650 × 10(-6) mm(2)/s in ≥10% of brain volume can differentiate patients with good versus poor outcome, though in this patient population the threshold was not 100% specific for poor outcome.


Asunto(s)
Encéfalo/patología , Coma/diagnóstico , Imagen de Difusión por Resonancia Magnética/métodos , Paro Cardíaco/complicaciones , Evaluación de Resultado en la Atención de Salud , Adulto , Anciano , Muerte Encefálica , Coma/etiología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos
13.
AJNR Am J Neuroradiol ; 35(7): 1303-8, 2014 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-24675999

RESUMEN

BACKGROUND AND PURPOSE: Controversy exists about the role of perfusion imaging in patient selection for endovascular reperfusion therapy in acute ischemic stroke. We hypothesized that perfusion imaging versus noncontrast CT- based selection would be associated with improved functional outcomes at 3 months. MATERIALS AND METHODS: We reviewed consecutive patients with anterior circulation strokes treated with endovascular reperfusion therapy within 8 hours and with baseline NIHSS score of ≥8. Baseline clinical data, selection mode (perfusion versus NCCT), angiographic data, complications, and modified Rankin Scale score at 3 months were collected. Using multivariable logistic regression, we assessed whether the mode of selection for endovascular reperfusion therapy (perfusion-based versus NCCT-based) was independently associated with good outcome. RESULTS: Two-hundred fourteen patients (mean age, 67.2 years; median NIHSS score, 18; MCA occlusion 74% and ICA occlusion 26%) were included. Perfusion imaging was used in 76 (35.5%) patients (39 CT and 37 MR imaging). Perfusion imaging-selected patients were more likely to have good outcomes compared with NCCT-selected patients (55.3 versus 33.3%, P = .002); perfusion selection by CT was associated with similar outcomes as that by MR imaging (CTP, 56.; MR perfusion, 54.1%; P = .836). In multivariable analysis, CT or MR perfusion imaging selection remained strongly associated with good outcome (adjusted OR, 2.34; 95% CI, 1.22-4.47), independent of baseline severity and reperfusion. CONCLUSIONS: In this multicenter study, patients with acute ischemic stroke who underwent perfusion imaging were more than 2-fold more likely to have good outcomes following endovascular reperfusion therapy. Randomized studies should compare perfusion imaging with NCCT imaging for patient selection for endovascular reperfusion therapy.


Asunto(s)
Isquemia Encefálica/diagnóstico por imagen , Isquemia Encefálica/cirugía , Angiografía Cerebral/estadística & datos numéricos , Revascularización Cerebral/estadística & datos numéricos , Procedimientos Endovasculares/estadística & datos numéricos , Accidente Cerebrovascular/diagnóstico por imagen , Accidente Cerebrovascular/cirugía , Enfermedad Aguda , Anciano , Isquemia Encefálica/mortalidad , Revascularización Cerebral/mortalidad , Procedimientos Endovasculares/mortalidad , Femenino , Humanos , Illinois/epidemiología , Masculino , Prevalencia , Reproducibilidad de los Resultados , Estudios Retrospectivos , Factores de Riesgo , Sensibilidad y Especificidad , Accidente Cerebrovascular/mortalidad , Tasa de Supervivencia , Resultado del Tratamiento
14.
Phlebology ; 29(6): 397-400, 2014 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-23820117

RESUMEN

BACKGROUND: There are several endovenous methods to ablate the saphenous vein, all of which require tumescent anesthesia. This report was designed to evaluate the efficacy of a tumescent-free technique using mechanochemical ablation (MOCA). METHODS: This was a prospective observational multicenter report on the efficacy of MOCA in selected patients with lower extremity chronic venous disease. Demographic information, clinical and procedural data were collected on a customized database. The distribution and extent of venous reflux and the closure rate of the treated veins were assessed with duplex ultrasound. Pain was evaluated during the procedure and postoperatively using an analog scale. The presence and severity of complications were recorded. Patient improvement was assessed by clinical-etiology-anatomy-pathophysiology (CEAP) class and venous clinical severity score (VCSS). RESULTS: There were 126 patients that were included at baseline, 81% females, with a mean age of 65.5 ± 14 years. The average BMI was 30.5 ± 6. The mean diameter of the great saphenous vein in the upper thigh was 7.3 mm and the mean treatment length was 38 cm. Adjunctive treatment of the varicosities was performed in 11% of patients during the procedure. Closure rates were 100% at one week, 98% at three months, and 94% at six months. Post-procedure complications included hematoma 1%, ecchymosis 9%, and thrombophlebitis 10%. There were no cases of venous thromboembolism. There was significant improvement in VCSS (p < 0.001) for all time intervals. CONCLUSION: MOCA of the saphenous veins has the advantage of endovenous ablation without tumescent anesthesia, making it an almost pain-free procedure. High occlusion rates with significant clinical improvement can be achieved with this method at short term.


Asunto(s)
Vena Safena/cirugía , Várices/cirugía , Procedimientos Quirúrgicos Vasculares/métodos , Anciano , Enfermedad Crónica , Femenino , Humanos , Masculino , Persona de Mediana Edad , Manejo del Dolor , Dolor Postoperatorio/fisiopatología , Dolor Postoperatorio/terapia , Procedimientos Quirúrgicos Vasculares/efectos adversos
15.
AJNR Am J Neuroradiol ; 34(12): 2252-8, 2013 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-23828109

RESUMEN

BACKGROUND AND PURPOSE: Contrast enhancement of intracranial atherosclerotic plaques has recently been investigated using high field and high resolution MR imaging as a risk factor in the development of ischemic stroke. We studied the reliability of conventional MR imaging at 1.5T in evaluating intraplaque enhancement and its relationship with acute cerebrovascular ischemic presentations in patients with severe intracranial atherosclerotic disease. MATERIALS AND METHODS: We retrospectively identified and analyzed 19 patients with 22 high-grade intracranial atherosclerotic disease plaques (>70% stenosis) in vessels cross-sectionally visualized by neuroanatomic MR imaging. Atherosclerotic plaques were classified as asymptomatic or symptomatic. Two blinded neuroradiologists independently ranked each lesion for the presence of intraplaque enhancement by use of a 5-point scale (1-5). Furthermore, plaque enhancement was quantified as the relative change in T1WI spin-echo signal intensity (postcontrast/precontrast) in the vessel wall at the site of each intracranial atherosclerotic disease lesion. RESULTS: Intraplaque enhancement was observed in 7 of 10 (70%) symptomatic plaques, in contrast to 1 of 12 (8%) asymptomatic plaques. Interobserver reliability correlated well for intraplaque enhancement (κ = 0.82). The degree of relative plaque enhancement in symptomatic versus asymptomatic lesions (63% versus 23%) was statistically significant (P = .001, t test). CONCLUSIONS: In this pilot study, we determined that intraplaque enhancement could be reliably evaluated with the use of cross-sectional imaging and analysis of vessels/plaques by use of conventional neuroanatomic MR imaging protocols. In addition, we observed a strong association between intraplaque enhancement in severe intracranial atherosclerotic disease lesions and ischemic events with the use of conventional MR imaging. Our preliminary study suggests that T1 gadolinium-enhancing plaques may be an indicator of progressing or symptomatic intracranial atherosclerotic disease.


Asunto(s)
Isquemia Encefálica/etiología , Isquemia Encefálica/patología , Gadolinio , Arteriosclerosis Intracraneal/complicaciones , Arteriosclerosis Intracraneal/patología , Angiografía por Resonancia Magnética/métodos , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Masculino , Persona de Mediana Edad , Variaciones Dependientes del Observador , Reproducibilidad de los Resultados , Estudios Retrospectivos , Sensibilidad y Especificidad
16.
J Endocrinol ; 214(2): 121-31, 2012 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-22378920

RESUMEN

Adrenarche is most commonly defined as a prepubertal increase in circulating adrenal androgens, dehydroepiandrosterone (DHEA) and its sulfo-conjugate (DHEAS). This event is thought to have evolved in humans and some great apes but not in Old World monkeys, perhaps to promote brain development. Whether adrenarche represents a shared, derived developmental event in humans and our closest relatives, adrenal androgen secretion (and its regulation) is of considerable clinical interest. Specifically, adrenal androgens play a significant role in the pathophysiology of polycystic ovarian disease and breast and prostate cancers. Understanding the development of androgen secretion by the human adrenal cortex and identifying a suitable model for its study are therefore of central importance for clinical and evolutionary concerns. This review will examine the evidence for adrenarche in nonhuman primates (NHP) and suggest that a broader definition of this developmental event is needed, including morphological, biochemical, and endocrine criteria. Using such a definition, evidence from recent studies suggests that adrenarche evolved in Old World primates but spans a relatively brief period early in development compared with humans and some great apes. This emphasizes the need for frequent longitudinal sampling in evaluating developmental changes in adrenal androgen secretion as well as the tenuous nature of existing evidence of adrenarche in some species among the great apes. Central to an understanding of the regulation of adrenal androgen production in humans is the recognition of the complex nature of adrenarche and the need for more carefully conducted comparative studies and a broader definition in order to promote investigation among NHP in particular.


Asunto(s)
Adrenarquia/fisiología , Primates/fisiología , Terminología como Asunto , Adrenarquia/sangre , Adrenarquia/genética , Adrenarquia/metabolismo , Animales , Evolución Biológica , Endocrinología/métodos , Endocrinología/tendencias , Humanos , Estudios Longitudinales , Primates/clasificación , Primates/genética , Primates/metabolismo , Proyectos de Investigación
17.
J Neurol Neurosurg Psychiatry ; 82(11): 1201-5, 2011 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-21551473

RESUMEN

BACKGROUND AND AIM: Identification of ischaemic stroke subtype currently relies on clinical evaluation supported by various diagnostic studies. The authors sought to determine whether specific diffusion-weighted MRI (DWI) patterns could reliably guide the subsequent work-up for patients presenting with acute ischaemic stroke symptoms. METHODS: 273 consecutive patients with acute ischaemic stroke symptoms were enrolled in this prospective, observational, single-centre NIH-sponsored study. Electrocardiogram, non-contrast head CT, brain MRI, head and neck magnetic resonance angiography (MRA) and transoesophageal echocardiography were performed in this prespecified order. Stroke neurologists determined TOAST (Trial of Org 10172 in Acute Stroke Treatment) classification on admission and on discharge. Initial TOAST stroke subtypes were compared with the final TOAST subtype. If the final subtype differed from the initial assessment, the diagnostic test deemed the principal determinant of change was recorded. These principal determinants of change were compared between a CT-based and an MRI-based classification schema. RESULTS: Among patients with a thromboembolic DWI pattern, transoesophageal echocardiography was the principal determinant of diagnostic change in 8.8% versus 0% for the small vessel group and 1.7% for the other group (p<0.01). Among patients with the combination of a thromboembolic pattern on MRI and a negative cervical MRA, transoesophageal echocardiography led to a change in diagnosis in 12.1%. There was no significant difference between groups using a CT-based scheme. CONCLUSIONS: DWI patterns appear to predict stroke aetiologies better than conventional methods. The study data suggest an MRI-based diagnostic algorithm that can potentially obviate the need for echocardiography in one-third of stroke patients and may limit the number of secondary extracranial vascular imaging studies to approximately 10%.


Asunto(s)
Algoritmos , Imagen por Resonancia Magnética/métodos , Accidente Cerebrovascular/diagnóstico , Accidente Cerebrovascular/patología , Anciano , Encéfalo/patología , Isquemia Encefálica/patología , Diagnóstico por Computador/métodos , Imagen de Difusión por Resonancia Magnética/métodos , Electrocardiografía/métodos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Neurología/métodos , Estudios Prospectivos , Tromboembolia/patología , Tomografía Computarizada por Rayos X/métodos
18.
Maturitas ; 64(3): 193-5, 2009 Nov 20.
Artículo en Inglés | MEDLINE | ID: mdl-19783109

RESUMEN

This study tests the "adaptive onset" hypothesis (AOH) proposed by Kuhle and explores the potential adaptive origins of menopause (Kuhle (2007) [3]). The AOH posits that both menopause and the timing of its onset are adaptive, and that age at onset may be mediated according to the likelihood of successful continued reproduction. Twelve factors were hypothesized to predict whether continued reproduction would be successful. Eight factors were tested using data extracted from the NLS Mature Women cohort. Statistical analyses reveal no support for predictions of the AOH; in fact, a majority of analyses suggest trends opposite from those predicted.


Asunto(s)
Aptitud Genética , Menopausia , Adaptación Biológica , Factores de Edad , Femenino , Humanos , Persona de Mediana Edad , Modelos Teóricos
19.
Phys Rev Lett ; 103(26): 261802, 2009 Dec 31.
Artículo en Inglés | MEDLINE | ID: mdl-20366304

RESUMEN

This Letter reports on a search for nu(mu) --> nu(e) transitions by the MINOS experiment based on a 3.14x10(20) protons-on-target exposure in the Fermilab NuMI beam. We observe 35 events in the Far Detector with a background of 27+/-5(stat)+/-2(syst) events predicted by the measurements in the Near Detector. If interpreted in terms of nu(mu) --> nu(e) oscillations, this 1.5sigma excess of events is consistent with sin2(2theta(13)) comparable to the CHOOZ limit when |Delta m2|=2.43x10(-3) eV2 and sin2(2theta(23))=1.0 are assumed.

20.
Phys Rev Lett ; 101(22): 221804, 2008 Nov 28.
Artículo en Inglés | MEDLINE | ID: mdl-19113477

RESUMEN

We report the first detailed comparisons of the rates and spectra of neutral-current neutrino interactions at two widely separated locations. A depletion in the rate at the far site would indicate mixing between nu(mu) and a sterile particle. No anomalous depletion in the reconstructed energy spectrum is observed. Assuming oscillations occur at a single mass-squared splitting, a fit to the neutral- and charged-current energy spectra limits the fraction of nu(mu) oscillating to a sterile neutrino to be below 0.68 at 90% confidence level. A less stringent limit due to a possible contribution to the measured neutral-current event rate at the far site from nu(e) appearance at the current experimental limit is also presented.

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