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1.
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.

2.
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.

3.
Int J Cancer ; 94(4): 527-30, 2001 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-11745439

RESUMEN

Epstein-Barr virus (EBV) has been associated with the most common form of stomach neoplasms, the gastric carcinoma (GC). The presence of EBV-encoded small RNAtype-1 (EBER-1), a marker for EBV infection was analyzed by in situ hybridization (ISH) in 185 formalin-fixed and paraffin-embedded cases of GC from a high risk region. We found 31 (16.8%) EBV-positive cases with no relationship to age. Although male predominance (19% in males and 12.5% in females) was observed, the gender difference did not achieve statistical significance. Odds ratio (OR) for cardia location was 5.4 (95% CI 1.7-17.3) when antrum was used as referent category and the effects of gender and age were taken into account. The proportion of EBV-positive cases in diffuse histology was higher than intestinal type (OR = 4.8, 95% CI = 2.0-11.1). Our findings are contrary to a previously accepted hypothesis, that high-risk countries for GC have low rates of EBV-associated GC. In addition, our findings regarding location, histology and weak male predominance are different from what has been described in Asian and European countries, but similar to those described in Mexico and Mexican descendants living in the U.S. suggesting unique characteristics of EBV-associated GC in Latin-America.


Asunto(s)
Cardias/metabolismo , Herpesvirus Humano 4/metabolismo , Neoplasias Gástricas/virología , Adulto , Factores de Edad , Anciano , Anciano de 80 o más Años , Cardias/patología , Chile , Femenino , Mucosa Gástrica/metabolismo , Humanos , Hibridación in Situ , Masculino , Persona de Mediana Edad , Oportunidad Relativa , ARN/metabolismo , ARN Viral/biosíntesis , Factores Sexuales
4.
J Ethnopharmacol ; 78(1): 27-31, 2001 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-11585684

RESUMEN

The antiinflammatory and antipyretic activities of the petroleum ether extract (PEE), dichloromethane extract (DME) and methanol extract (ME1) of the aerial part of Psoralea glandulosa L. (Papilionaceae) were studied. The bioactivity-guided fractionation of the active extracts yielded the isolation of bakuchiol (Bk) from the petroleum ether as the active compound, cyclobakuchiols A and B (Cbk), and angelicin (Ang) from DME.


Asunto(s)
Analgésicos no Narcóticos/química , Analgésicos no Narcóticos/farmacología , Antiinflamatorios no Esteroideos/química , Antiinflamatorios no Esteroideos/farmacología , Plantas Medicinales/química , Psoralea/química , Analgésicos no Narcóticos/aislamiento & purificación , Animales , Antiinflamatorios no Esteroideos/aislamiento & purificación , Edema/inducido químicamente , Edema/prevención & control , Éteres , Femenino , Cobayas , Espectroscopía de Resonancia Magnética , Masculino , Metanol , Extractos Vegetales/química , Extractos Vegetales/farmacología , Conejos , Solventes
5.
Rev Med Chil ; 127(7): 775-81, 1999 Jul.
Artículo en Español | MEDLINE | ID: mdl-10668284

RESUMEN

BACKGROUND: The traditional methods to distinguish Chronic Follicular Gastritis and Primary Gastric Lymphoma do not allow an adequate definitive diagnosis in a significant number of cases. The molecular Biology diagnostic methods are based on the rearrangement of immunoglobulin genes. The polymerase chain reaction (PCR) specifically amplifies this rearrangement and allows molecular analysis of minimal tissue samples obtained with endoscopical biopsies. AIM: To test the usefulness of this PCR method in the differential diagnosis between Chronic Follicular Gastritis and Primary Gastric Lymphoma. MATERIAL AND METHODS: We analyzed the endoscopical biopsies of six Chronic Follicular Gastritis cases and eight surgically treated Primary Gastric Lymphoma cases, six with the correct diagnosis in the endoscopical biopsies and two with a diagnosis of Chronic Follicular Gastritis. RESULTS: A policlonal immunoglobulin rearrangement was found in the six cases with Chronic Follicular Gastritis. A monoclonal arrangement was found in 5 of 6 biopsies with the diagnosis of Primary Gastric Lymphoma. The same monoclonal rearrangement was observed in the two biopsies incorrectly diagnosed as Chronic Follicular Gastritis. CONCLUSIONS: PCR analysis of immunoglobulin rearrangement is a useful method in the differential diagnosis between Chronic Follicular Gastritis and Primary Gastric Lymphoma.


Asunto(s)
Gastritis Hipertrófica/diagnóstico , Inmunoglobulinas/genética , Linfoma/diagnóstico , Neoplasias Gástricas/diagnóstico , Enfermedad Crónica , Diagnóstico Diferencial , Electroforesis en Gel de Agar , Gastritis Hipertrófica/genética , Gastritis Hipertrófica/inmunología , Humanos , Linfoma/genética , Linfoma/inmunología , Reacción en Cadena de la Polimerasa , Neoplasias Gástricas/genética , Neoplasias Gástricas/inmunología
6.
Rev Med Chil ; 124(2): 204-8, 1996 Feb.
Artículo en Español | MEDLINE | ID: mdl-9213889

RESUMEN

AIM: To analyze the clinical presentation, pathological aspect and treatment of gastric adenomas. PATIENTS AND METHODS: Retrospective analysis of 75 patients aged 26 to 88 years in whom a gastric adenoma was diagnosed. RESULT: Seventy one patients had elevated endoscopical lesions and two had depressed or flat lesions. Ninety percent of lesions were located in the gastric antrum. Pathological study detected 6 focal carcinomas within the adenomas and 5 concomitant carcinomas located elsewhere in the stomach. Fifty four patients were subjected to endoscopical resection. Among patients with focal carcinomas, a gastrectomy was performed in four and endoscopical resection in two. CONCLUSIONS: Gastric adenomas must be considered in the differential diagnosis of gastric elevated lesions and may be confused in early gastric cancer. There is a histological resemblance between adenomas and gastric dysplasia described by several authors though only in our cases and in the Japanese literature the adenoma is referred to as mostly a polypoid sessile lesion.


Asunto(s)
Adenoma/patología , Neoplasias Gástricas/patología , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos
7.
Rev Med Chil ; 121(8): 889-96, 1993 Aug.
Artículo en Español | MEDLINE | ID: mdl-8296096

RESUMEN

Isosorbide 5-mononitrate reduces portal pressure in acute conditions. The aim of this work was to assess its effects and tolerance development after 30 days of use in alcoholic cirrhotic patients without history of variceal bleeding. Nine patients with portal hypertension (7 with esophageal varices) were studied. Hepatic and systemic hemodynamic parameters were measured in basal conditions, after one hour and after 30 days of treatment (40 mg b i d). One patient was lost from control at 2 weeks. In the total group, portal pressure decreased from 15.1 +/- 3.7 mm Hg to 12.1 +/- 5 at one hour and 11.3 +/- 5.5 mm Hg at 30 days (p < 0.002). In two patients, portal pressure was not modified. Portal blood flow increased significantly at one hour in the 7 responder patients. Hepatic blood flow (indocyanine green clearance) was not modified; thus, estimated hepatic resistance decreases in both periods. Intrinsic indocyanine green clearance (a measure of hepatic function) did not change in any period. Systemic blood pressure decreased and cardiac rate increased only after one hour. The fall in portal pressure did not correlate with changes in portal or hepatic blood flow. It is concluded that isosorbide 5-mononitrate decreased portal pressure in 7 out of nine patients, even after 30 days of treatment, without untoward effects over hepatic function or perfusion.


Asunto(s)
Hipertensión Portal/tratamiento farmacológico , Dinitrato de Isosorbide/análogos & derivados , Cirrosis Hepática Alcohólica/fisiopatología , Adulto , Anciano , Femenino , Hemodinámica/efectos de los fármacos , Humanos , Hipertensión Portal/fisiopatología , Dinitrato de Isosorbide/farmacología , Dinitrato de Isosorbide/uso terapéutico , Hígado/irrigación sanguínea , Cirrosis Hepática Alcohólica/tratamiento farmacológico , Masculino , Persona de Mediana Edad
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