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1.
Phys Rev Lett ; 128(9): 091803, 2022 Mar 04.
Artículo en Inglés | MEDLINE | ID: mdl-35302807

RESUMEN

We report the measurement of sub-MeV solar neutrinos through the use of their associated Cherenkov radiation, performed with the Borexino detector at the Laboratori Nazionali del Gran Sasso. The measurement is achieved using a novel technique that correlates individual photon hits of events to the known position of the Sun. In an energy window between 0.54 to 0.74 MeV, selected using the dominant scintillation light, we have measured 10 887_{-2103}^{+2386}(stat)±947(syst) (68% confidence interval) solar neutrinos out of 19 904 total events. This corresponds to a ^{7}Be neutrino interaction rate of 51.6_{-12.5}^{+13.9} counts/(day·100 ton), which is in agreement with the standard solar model predictions and the previous spectroscopic results of Borexino. The no-neutrino hypothesis can be excluded with >5σ confidence level. For the first time, we have demonstrated the possibility of utilizing the directional Cherenkov information for sub-MeV solar neutrinos, in a large-scale, high light yield liquid scintillator detector. This measurement provides an experimental proof of principle for future hybrid event reconstruction using both Cherenkov and scintillation signatures simultaneously.

2.
Phys Rev Lett ; 129(25): 252701, 2022 Dec 16.
Artículo en Inglés | MEDLINE | ID: mdl-36608219

RESUMEN

We present an improved measurement of the carbon-nitrogen-oxygen (CNO) solar neutrino interaction rate at Earth obtained with the complete Borexino Phase-III dataset. The measured rate, R_{CNO}=6.7_{-0.8}^{+2.0} counts/(day×100 tonnes), allows us to exclude the absence of the CNO signal with about 7σ C.L. The correspondent CNO neutrino flux is 6.6_{-0.9}^{+2.0}×10^{8} cm^{-2} s^{-1}, taking into account the neutrino flavor conversion. We use the new CNO measurement to evaluate the C and N abundances in the Sun with respect to the H abundance for the first time with solar neutrinos. Our result of N_{CN}=(5.78_{-1.00}^{+1.86})×10^{-4} displays a ∼2σ tension with the "low-metallicity" spectroscopic photospheric measurements. Furthermore, our result used together with the ^{7}Be and ^{8}B solar neutrino fluxes, also measured by Borexino, permits us to disfavor at 3.1σ C.L. the "low-metallicity" standard solar model B16-AGSS09met as an alternative to the "high-metallicity" standard solar model B16-GS98.

3.
Phys Rev Lett ; 106(24): 242302, 2011 Jun 17.
Artículo en Inglés | MEDLINE | ID: mdl-21770567

RESUMEN

We report on an exclusive and kinematically complete high-statistics measurement of the basic double-pionic fusion reaction pn→dπ(0)π(0) over the full energy region of the ABC effect, a pronounced low-mass enhancement in the ππ-invariant mass spectrum. The measurements, which cover also the transition region to the conventional t-channel ΔΔ process, were performed with the upgraded WASA detector setup at COSY. The data reveal the Abashian-Booth-Crowe effect to be uniquely correlated with a Lorentzian energy dependence in the integral cross section. The observables are consistent with a narrow resonance with m=2.37 GeV, Γ≈70 MeV and I(J(P))=0(3(+)) in both pn and ΔΔ systems. Necessary further tests of the resonance interpretation are discussed.

4.
Rev. ADM ; 78(6): 309-313, nov.-dic. 2021.
Artículo en Español | LILACS | ID: biblio-1354275

RESUMEN

Introducción: El SARS-CoV-2 afecta el sistema respiratorio en diferentes grados. La cavidad oral es el lugar más colonizado por bacterias, por lo tanto, al no tener una adecuada higiene pueden presentarse diferentes enfermedades secundarias, lo que ha causado alerta en el gremio odontológico, ya que puede contribuir a complicaciones posteriores en los pacientes. Material y métodos: El estudio fue conformado por 47 pacientes voluntarios recuperados de SARS-CoV-2, residentes de Montemorelos, Nuevo León, México, donde fueron atendidos en Bucalia Dent, consultorio dental. Después del consentimiento informado de cada paciente, se realizó una historia clínica para conocer los síntomas, enfermedades sistémicas, ausencia de dientes y nivel de inflamación gingival de acuerdo al índice de Loe y Silness. A continuación, se tomó una muestra de biofilm microbiano (placa dentobacteriana), la cual se suspendió en una solución buffer de fosfato, posteriormente fue llevada al Centro de Investigación y Desarrollo en Ciencias de la Salud (CIDICS), Monterrey, N.L, México. Se extrajo DNA y se purificó, después se realizó PCR para detectar los patógenos orales; la PCR se visualizó en gel de agarosa (1.5%) por tinción de bromuro de etidio. Resultados: Se detectó 80.85% Porphyromona gingivalis y 68.09% Fusobacterium nucleatum en pacientes recuperados de SARS-CoV-2; 23.4% presentaron inflamación leve de acuerdo al índice de Loe y Silness, 54.5% fueron masculinos y 45.5% femeninos. Por otro lado, 36.4% de los pacientes con inflamación leve tenían de cuatro a seis dientes ausentes. En estos pacientes se detectó 18.18% únicamente con Fusobacterium nucleatum y 27.27% sólo con Porphyromona gingivalis; el sexo masculino tuvo predisposición en 66.6% y el femenino en 33.33%. Se observó infección con los dos patógenos presentes en 45.45%; y 60% de estos pacientes fueron masculinos. Conclusiones: Los pacientes recuperados de SARSCoV- 2 analizados en esta investigación mostraron mala higiene oral y alta prevalencia de los patógenos mencionados altamente relacionados a inflamación gingival o enfermedad periodontal, lo que nos indica que es indispensable la intervención del odontólogo al finalizar el periodo de infección de cada paciente (AU)


Introduction: SARS-CoV-2 affects the respiratory system to different degrees. The oral cavity is a colonized place by bacterias, therefore, by not having good hygiene, different secondary diseases can occur; this has caused an alert in the dental industry, since it can contribute to later complications in patients. Material and methods: The study was conducted in 47 SARS-CoV-2 recovered volunteers from the Montemorelos city of the Nuevo León state, Mexico, who were attended at the Bucalia Dent dental clinic. An informed consent was obtained from each of the patients, then their clinical history was documented in order to know the symptoms, previous systemic diseases, absence of teeth and degree of gingival inflammation, as suggested by Loe and Silness. Subsequently, a dental plaque sample was taken from all patients, which was suspended in a phosphate buffered solution and shipped to The Center for Research and Development in Health Sciences (CIDICS), Monterrey, NL, Mexico for storage. DNA extraction and purification was performed and PCR was carried out for the oral pathogens detection. All PCR products were visualized on 1.5% agarose gel by ethidium bromide staining. Results: Porphyromona gingivalis and Fusobacterium nucleatum were detected in 80.85% and 68.09% of SARS-CoV-2 recovered patients, respectively. 23.4% showed mild inflammation based on the Loe and Silness criteria, 54.5% were male and 45.5% female. On the other hand, 36.4% of patients with mild inflammation had between 4 to 6 missing teeth. A single infection by Fusobacterium nucleatum was detected in 18.18% and by Porphyromona gingivalis in 27.27%; the male sex had a predisposition with 66.66% and 33.33% female; coinfection of both pathogens was observed in 45.45% where 60% were male. Conclusions: SARS-CoV-2 recovered patients show poor oral hygiene and a high prevalence of oral pathogens related to the development of inflammatory gingival or periodontal disease, this suggests the need for an odontological clinical intervention at the end of the course of infection or disease caused by SARS-CoV-2 (AU)


Asunto(s)
Humanos , Masculino , Femenino , Adulto , Higiene Bucal , Fusobacterium nucleatum , Porphyromonas gingivalis , SARS-CoV-2 , ADN , Índice de Higiene Oral , Índice Periodontal , Reacción en Cadena de la Polimerasa , Placa Dental/microbiología , Electroforesis en Gel de Agar , Distribución por Edad y Sexo , Gingivitis/epidemiología , México
5.
Dig Liver Dis ; 35(8): 557-65, 2003 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-14567460

RESUMEN

BACKGROUND: Cyclooxygenase (COX)-2 is up-regulated in most colorectal cancers. Chronic use of non-steroidal anti-inflammatory drugs, which target cyclooxygenases, have been shown to reduce the risk of these cancers. However, the mechanisms underlying this protective effect remain unclear. AIMS: The aim of our study was to characterize the effects of two COX-2 selective inhibitors, NS-398 and nimesulide, on colorectal cancer cell proliferation, and to describe the molecular mechanisms involved. MATERIALS AND METHODS: HT-29 and SW-1116 cell lines were cultured with either NS-398 or nimesulide. Cell proliferation was assessed by staining DNA with crystal violet. Cell cycle repartition and apoptosis were analysed by flow cytometry. The expression of COX-1 and COX-2. and of two cyclin dependent kinase inhibitors, p21Cip1 and p27Kip1, was analysed by Western blotting and RT-PCR. RESULTS: Both drugs dose-dependently inhibited cell proliferation and induced G1 cell cycle blockade. HT-29 cells were more sensitive to both drugs than SW-1116 cells. p21Cip1 and p27Kip1 were induced on both cell lines. Concomitant induction of p21Cip1 mRNA indicates transcriptional modulation, whereas induction of p27Kip1 only at the protein level suggests post-translational modulation. CONCLUSION: NS-398 and nimesulide inhibit colorectal cell proliferation through induction of p21Cip1 and p27Kip1.


Asunto(s)
Adenocarcinoma/metabolismo , División Celular/efectos de los fármacos , Neoplasias Colorrectales/metabolismo , Inhibidores de la Ciclooxigenasa/farmacología , Nitrobencenos/farmacología , Sulfonamidas/farmacología , Apoptosis , Western Blotting , Proteínas de Ciclo Celular/biosíntesis , Inhibidor p21 de las Quinasas Dependientes de la Ciclina , Inhibidor p27 de las Quinasas Dependientes de la Ciclina , Quinasas Ciclina-Dependientes/antagonistas & inhibidores , Ciclinas/biosíntesis , Ciclooxigenasa 2 , Inhibidores de la Ciclooxigenasa 2 , Inhibidores Enzimáticos/metabolismo , Citometría de Flujo , Fase G1/efectos de los fármacos , Humanos , Isoenzimas/metabolismo , Proteínas de la Membrana , Prostaglandina-Endoperóxido Sintasas/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Células Tumorales Cultivadas , Proteínas Supresoras de Tumor/biosíntesis
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