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1.
Rhinology ; 2024 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-39026455

RESUMO

BACKGROUND: Despite advances in techniques for olfactory neuroblastoma (ONB), such as unilateral cranial resection, preserving the patient's sense of smell remains a challenge. This study aimed to examine the effectiveness of post-operative olfactory training in patients who underwent unilateral resection of ONB. METHODS: This retrospective cohort study assessed the effect of post-operative olfactory training on olfactory preservation in patients with ONB undergoing unilateral cranial resection. Patients were divided into training intervention (n = 5) and non-intervention (n = 6) groups. Olfactory tests were conducted pre-operatively and at multiple post-operative intervals. RESULTS: Partial olfactory function was preserved in all cases in the training intervention group, whereas only 17% of cases in the non-intervention group maintained partial olfactory function. Significant improvements in olfactory test scores were observed in the training intervention group compared with the non-intervention group. CONCLUSIONS: Our findings suggest that post-operative olfactory training could aid in olfactory preservation for patients with ONB after unilateral cranial resection. However, these results should be interpreted with caution, and further research with larger cohorts and extended follow-up periods is needed to confirm these observations.

2.
Lett Appl Microbiol ; 74(4): 472-481, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-34978719

RESUMO

Emergence and rapid spread of multidrug-resistant (MDR) bacteria including Vibrio cholerae are a global public health issue. Much attention has been paid to natural compounds, such as spices and herbs to find novel antimicrobial compounds as they are considered to be cheaper alternatives to develop as a drug. Here, we show that methanol extract of white pepper could inhibit the growth of V. cholerae O1 El Tor variant, responsible for the recent outbreaks/epidemics. Furthermore, we demonstrate for the first time that piperine, the major component of white pepper, showed a dose-dependent bactericidal effect on V. cholerae growth irrespective of their biotypes and serogroups in the presence of 200 and 300 µg ml-1 of piperine, respectively. Piperine also inhibited the growth of MDR strains of Pseudomonas aeruginosa, Escherichia coli isolated from poultry and enterohemorrhagic/enteroaggregative E. coli O104 in the presence of 200 µg ml-1 . Interestingly, we did not observe any significant inhibitory effect of piperine on E. coli strains isolated from healthy person even up to 200 µg ml-1 . Our data suggest that piperine could be a novel antimicrobial agent in therapeutic and preventive applications against infections caused by pathogenic bacteria including MDR strains.


Assuntos
Cólera , Piper nigrum , Vibrio cholerae O1 , Vibrio cholerae , Alcaloides , Benzodioxóis , Cólera/microbiologia , Escherichia coli , Variação Genética , Humanos , Piperidinas , Alcamidas Poli-Insaturadas
3.
Clin Exp Immunol ; 200(3): 302-309, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32155293

RESUMO

Stroke can be a cause of death, while in non-fatal cases it is a common cause of various disabilities resulting from associated brain damage. However, whether a specific periodontal pathogen is associated with increased risk of unfavorable outcome after stroke remains unknown. We examined risk factors for unfavorable outcome following stroke occurrence, including serum antibody titers to periodontal pathogens. The enrolled cohort included 534 patients who had experienced an acute stroke, who were divided into favorable (n = 337) and unfavorable (n = 197) outcome groups according to modified ranking scale (mRS) score determined at 3 months after onset (favorable = score 0 or 1; unfavorable = score 2-6). The associations of risk factors with unfavorable outcome, including serum titers of IgG antibodies to 16 periodontal pathogens, were examined. Logistic regression analysis showed that the initial National Institutes of Health stroke scale score [odds ratio (OR) = 1·24, 95% confidence interval (CI) = 1·18-1·31, P < 0·001] and C-reactive protein (OR = 1·29, 95% CI = 1·10-1·51, P = 0·002) were independently associated with unfavorable outcome after stroke. Following adjustment with those, detection of the antibody for Fusobacterium nucleatum ATCC 10953 in serum remained an independent predictor of unfavorable outcome (OR = 3·12, 95% CI = 1·55-6·29, P = 0·002). Determination of the antibody titer to F. nucleatum ATCC 10953 in serum may be useful as a predictor of unfavorable outcome after stroke.


Assuntos
Anticorpos Antibacterianos/sangue , Fusobacterium nucleatum/metabolismo , Imunoglobulina G/sangue , Acidente Vascular Cerebral/sangue , Idoso , Idoso de 80 Anos ou mais , Anticorpos Antibacterianos/imunologia , Feminino , Fusobacterium nucleatum/imunologia , Humanos , Imunoglobulina G/imunologia , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Fatores de Risco , Acidente Vascular Cerebral/imunologia
4.
Phys Rev Lett ; 124(16): 161802, 2020 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-32383902

RESUMO

Electron antineutrino appearance is measured by the T2K experiment in an accelerator-produced antineutrino beam, using additional neutrino beam operation to constrain parameters of the Pontecorvo-Maki-Nakagawa-Sakata (PMNS) mixing matrix. T2K observes 15 candidate electron antineutrino events with a background expectation of 9.3 events. Including information from the kinematic distribution of observed events, the hypothesis of no electron antineutrino appearance is disfavored with a significance of 2.40σ and no discrepancy between data and PMNS predictions is found. A complementary analysis that introduces an additional free parameter which allows non-PMNS values of electron neutrino and antineutrino appearance also finds no discrepancy between data and PMNS predictions.

5.
Eur J Neurol ; 26(11): 1408-1416, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31136060

RESUMO

BACKGROUND AND PURPOSE: Whether the neuromelanin-positive substantia nigra pars compacta area (NM-SNc) on neuromelanin magnetic resonance imaging (NM-MRI) and the specific binding ratio (SBR) on 123 I-N-v-fluoropropyl-2b-carbomethoxy3b-(4-iodophenyl)nortropane single photon emission computed tomography (DaT-SPECT) can be correlated with motor fluctuations (MFs) in advanced Parkinson's disease (PD) was investigated. METHODS: Thirty-five PD patients (60 ± 13 years) and 23 healthy individuals as controls (59 ± 19 years) were enrolled. The relationships between NM-MRI and DaT-SPECT were prospectively examined in two subgroups divided according to the presence or absence of MFs. Multivariate analysis was performed using the Cox proportional hazard model to screen for association factors. RESULTS: The NM-SNc size was correlated with the SBR (Spearman's ρ = 0.43, P < 0.05). The NM-SNc size was significantly reduced in PD with MFs compared with the subgroup without (P < 0.001), whereas the SBR did not significantly differ between the groups. NM-SNc size was a significant association factor for MFs (hazard ratio 0.94, P = 0.04). In receiver operating characteristic analysis of the factors for MF occurrence, the area under the receiver operating characteristic curve of the NM-SNc size showed a significant difference of 0.89 (P < 0.05) but no significant difference was found in the SBR. CONCLUSIONS: NM-SNc size was significantly correlated with the SBR in PD, but several factors in advanced PD were more closely associated with NM-SNc size than the SBR. NM-MRI might reflect the status of advanced PD more accurately than DaT-SPECT. Therefore, NM-MRI appears to provide a better marker for discriminating advanced PD than DaT-SPECT.


Assuntos
Melaninas/análise , Doença de Parkinson/diagnóstico , Tomografia Computadorizada de Emissão de Fóton Único/métodos , Idoso , Idoso de 80 Anos ou mais , Biomarcadores , Encéfalo/diagnóstico por imagem , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Transtornos dos Movimentos/etiologia , Transtornos dos Movimentos/fisiopatologia , Estudos Prospectivos , Valores de Referência
6.
Phys Rev Lett ; 121(17): 171802, 2018 Oct 26.
Artigo em Inglês | MEDLINE | ID: mdl-30411920

RESUMO

The T2K experiment measures muon neutrino disappearance and electron neutrino appearance in accelerator-produced neutrino and antineutrino beams. With an exposure of 14.7(7.6)×10^{20} protons on target in the neutrino (antineutrino) mode, 89 ν_{e} candidates and seven anti-ν_{e} candidates are observed, while 67.5 and 9.0 are expected for δ_{CP}=0 and normal mass ordering. The obtained 2σ confidence interval for the CP-violating phase, δ_{CP}, does not include the CP-conserving cases (δ_{CP}=0, π). The best-fit values of other parameters are sin^{2}θ_{23}=0.526_{-0.036}^{+0.032} and Δm_{32}^{2}=2.463_{-0.070}^{+0.071}×10^{-3} eV^{2}/c^{4}.

7.
Phys Rev Lett ; 120(21): 211801, 2018 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-29883136

RESUMO

The OPERA experiment was designed to study ν_{µ}→ν_{τ} oscillations in the appearance mode in the CERN to Gran Sasso Neutrino beam (CNGS). In this Letter, we report the final analysis of the full data sample collected between 2008 and 2012, corresponding to 17.97×10^{19} protons on target. Selection criteria looser than in previous analyses have produced ten ν_{τ} candidate events, thus reducing the statistical uncertainty in the measurement of the oscillation parameters and of ν_{τ} properties. A multivariate approach for event identification has been applied to the candidate events and the discovery of ν_{τ} appearance is confirmed with an improved significance level of 6.1σ. |Δm_{32}^{2}| has been measured, in appearance mode, with an accuracy of 20%. The measurement of the ν_{τ} charged-current cross section, for the first time with a negligible contamination from ν[over ¯]_{τ}, and the first direct evidence for the ν_{τ} lepton number are also reported.

8.
J Clin Pharm Ther ; 43(5): 633-639, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-29981285

RESUMO

WHAT IS KNOWN AND OBJECTIVE: Roxadustat is a hypoxia-inducible factor prolyl hydroxylase inhibitor currently being investigated for the treatment of anemia in chronic kidney disease. Lanthanum carbonate is a phosphate binder that is commonly used to treat hyperphosphatemia in patients with chronic kidney disease. This study investigated the effect of lanthanum carbonate on the pharmacokinetics, safety and tolerability of a single oral dose of roxadustat in healthy non-elderly adult male subjects. METHODS: This was an open-label, randomized, two-period, two-sequence crossover study in non-elderly healthy adult males. Subjects randomized to Group 1 received roxadustat alone during Period 1 and roxadustat concomitantly with lanthanum carbonate during Period 2; subjects randomized to Group 2 received roxadustat concomitantly with lanthanum carbonate during Period 1 and roxadustat alone during Period 2. All subjects received a single oral dose of 100 mg roxadustat on Day 1 in both periods. Subjects receiving concomitant lanthanum carbonate received 750 mg lanthanum carbonate three times daily on Days 1 and 2. Pharmacokinetic assessments were conducted on Days 1-4 in both periods. The primary study outcomes were the area under the concentration-time curve from the time of dosing extrapolated to infinity (AUCinf ), and maximum concentration (Cmax ); the geometric least squares mean ratio (GMR; roxadustat + lanthanum carbonate/roxadustat alone) and corresponding 90% confidence interval (CI) was calculated for AUCinf and Cmax . Safety was assessed by the occurrence of treatment-emergent adverse events (TEAEs), laboratory test results, vital signs and standard 12-lead electrocardiogram. RESULTS AND DISCUSSION: A total of 18 subjects were enrolled (Group 1, n = 9; Group 2, n = 9); no subjects discontinued from the study. Roxadustat was rapidly absorbed, reaching maximum plasma concentration between 1 and 4 hours. The GMRs for AUCinf and Cmax were 88.00% (90% CI: 84.01, 92.17) and 98.58% (90% CI: 92.92, 104.58), respectively. The 90% CIs for both parameters were within the no-effect boundaries of 80% and 125%, indicating a lack of effect of lanthanum carbonate on roxadustat absorption. No deaths or serious TEAEs occurred. WHAT IS NEW AND CONCLUSIONS: Concomitant administration of a single oral dose of 100 mg roxadustat and 750 mg lanthanum carbonate three times daily did not impact the AUCinf or Cmax of roxadustat and was considered safe and well tolerated in non-elderly healthy adult male Japanese subjects.


Assuntos
Glicina/análogos & derivados , Isoquinolinas/farmacocinética , Lantânio/efeitos adversos , Administração Oral , Adulto , Anemia/tratamento farmacológico , Anemia/etiologia , Área Sob a Curva , Estudos Cross-Over , Glicina/farmacocinética , Glicina/uso terapêutico , Humanos , Isoquinolinas/uso terapêutico , Masculino , Insuficiência Renal Crônica/complicações , Adulto Jovem
9.
J Neuroradiol ; 45(3): 164-168, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29132939

RESUMO

BACKGROUND AND PURPOSE: Segmented brain tissue and myelin volumes can now be automatically calculated using dedicated software (SyMRI), which is based on quantification of R1 and R2 relaxation rates and proton density. The aim of this study was to determine the validity of SyMRI brain tissue and myelin volumetry using various in-plane resolutions. METHODS: We scanned 10 healthy subjects on a 1.5T MR scanner with in-plane resolutions of 0.8, 2.0 and 3.0mm. Two scans were performed for each resolution. The acquisition time was 7-min and 24-sec for 0.8mm, 3-min and 9-sec for 2.0mm and 1-min and 56-sec for 3.0mm resolutions. The volumes of white matter (WM), gray matter (GM), cerebrospinal fluid (CSF), non-WM/GM/CSF (NoN), brain parenchymal volume (BPV), intracranial volume (ICV) and myelin were compared between in-plane resolutions. Repeatability for each resolution was then analyzed. RESULTS: No significant differences in volumes measured were found between the different in-plane resolutions, except for NoN between 0.8mm and 2.0mm and between 2.0mm and 3.0mm. The repeatability error value for the WM, GM, CSF, NoN, BPV and myelin volumes relative to ICV was 0.97%, 1.01%, 0.65%, 0.86%, 1.06% and 0.25% in 0.8mm; 1.22%, 1.36%, 0.73%, 0.37%, 1.18% and 0.35% in 2.0mm and 1.18%, 1.02%, 0.96%, 0.45%, 1.36%, and 0.28% in 3.0mm resolutions. CONCLUSION: SyMRI brain tissue and myelin volumetry with low in-plane resolution and short acquisition times is robust and has a good repeatability so could be useful for follow-up studies.


Assuntos
Encéfalo/anatomia & histologia , Processamento de Imagem Assistida por Computador/métodos , Imageamento por Ressonância Magnética/mortalidade , Bainha de Mielina , Adulto , Encéfalo/diagnóstico por imagem , Feminino , Humanos , Masculino , Tamanho do Órgão , Software , Adulto Jovem
10.
Phys Rev Lett ; 118(15): 151801, 2017 Apr 14.
Artigo em Inglês | MEDLINE | ID: mdl-28452532

RESUMO

T2K reports its first results in the search for CP violation in neutrino oscillations using appearance and disappearance channels for neutrino- and antineutrino-mode beams. The data include all runs from January 2010 to May 2016 and comprise 7.482×10^{20} protons on target in neutrino mode, which yielded in the far detector 32 e-like and 135 µ-like events, and 7.471×10^{20} protons on target in antineutrino mode, which yielded 4 e-like and 66 µ-like events. Reactor measurements of sin^{2}2θ_{13} have been used as an additional constraint. The one-dimensional confidence interval at 90% for the phase δ_{CP} spans the range (-3.13, -0.39) for normal mass ordering. The CP conservation hypothesis (δ_{CP}=0, π) is excluded at 90% C.L.

12.
Clin Exp Obstet Gynecol ; 44(2): 190-194, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29746020

RESUMO

OBJECTIVES: The authors determined associations of maternal pre-pregnancy obesity with adverse pregnancy outcomes and evaluated how gestational weight gain affects risks for such outcomes in Japanese obese pregnant women. MATERIALS AND METHODS: Among women who delivered at the Perinatal Center for Maternity and Neonatal, Yokohama City University Medical Center, between January 2001 and December 2012, the authors ascertained adverse pregnancy outcome incidences in 207 pre-pregnancy obese (body mass index [BMI] = 30 kg/m², obese group), 661 pre-pregnancy overweight (BMI = 25-29.9 kg/m², overweight group), and 6,801 pre-pregnancy normal weight (BMI= 18.5-24.9 kg/m², normal group) women. Subjects were stratified by weekly weight gain during the second/third trimesters to investigate associations between gestational weight gain and adverse pregnancy outcomes. Optimal weight gain for obese pregnant women was also examined. RESULTS: In the obese and overweight groups, incidences of pregnancy induced hypertension (PIH), gestational diabetes mellitus (GDM), large for gestational age (LGA), preterm birth, preterm prelabor rupture of membranes (PPROM), and spontaneous preterm birth were significantly higher than in the normal group. Incidences of adverse pregnancy outcomes were ap- parently higher in the obese than in the overweight group. In the latter, the incidence of large for gestational age was significantly higher in women with weight gains of 0.5 kg/week, whereas no difference in pregnancy outcomes was observed in the obese group regardless of gestational weight gain. CONCLUSION: In obese women, incidences of adverse pregnancy outcomes were higher, and pregnancy out- comes were difficult to improve with gestational weight control. Thus, it.is important to reach an optimal weight before pregnancy.


Assuntos
Diabetes Gestacional/epidemiologia , Hipertensão Induzida pela Gravidez/epidemiologia , Obesidade , Complicações na Gravidez , Adulto , Índice de Massa Corporal , Feminino , Humanos , Incidência , Recém-Nascido , Japão/epidemiologia , Obesidade/complicações , Obesidade/diagnóstico , Gravidez , Complicações na Gravidez/diagnóstico , Complicações na Gravidez/epidemiologia , Resultado da Gravidez/epidemiologia , Nascimento Prematuro/epidemiologia , Estudos Retrospectivos , Medição de Risco , Aumento de Peso
13.
Clin Exp Obstet Gynecol ; 44(2): 216-219, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29746025

RESUMO

A short umbilical cord is associated with adverse pregnancy outcomes. However, there is no universally accepted definition of a short cord. OBJECTIVE: This study aimed to determine the umbilical cord length showing the highest correlation with adverse pregnancy outcomes. MATERIALS AND METHODS: The authors retrospectively analyzed the clinical data of women who attempted vaginal birth in the present institution. Umbilical cord lengths were categorized into three groups: less than the first percentile, from the first percentile to less than the tenth percentile, and others. Maternal and neonatal characteristics previously suggested to affect cord length were evaluated. The main outcome was the rate of cesarean delivery. The authors also evaluated the frequency of operative vaginal delivery, small-for-gestational-age (SGA) births, neonatal intensive care unit (NICU) admission, umbilical artery pH < 7.1, and abnormal bleeding during delivery. RESULTS: Cord lengths of 35 and 45 cm corresponded to the first and tenth percentiles, respectively. A short cord was an indi- cator of unplanned cesarean delivery and small-for-gestational-age births. CONCLUSION: An umbilical cord length of ≤ 45 cm is a clinically useful indicator of adverse pregnancy outcomes.


Assuntos
Cesárea/estatística & dados numéricos , Sangue Fetal/química , Complicações do Trabalho de Parto , Resultado da Gravidez/epidemiologia , Cordão Umbilical/patologia , Adulto , Feminino , Humanos , Concentração de Íons de Hidrogênio , Recém-Nascido , Recém-Nascido Pequeno para a Idade Gestacional , Unidades de Terapia Intensiva Neonatal/estatística & dados numéricos , Japão/epidemiologia , Complicações do Trabalho de Parto/diagnóstico , Complicações do Trabalho de Parto/epidemiologia , Complicações do Trabalho de Parto/etiologia , Tamanho do Órgão , Gravidez , Estudos Retrospectivos , Estatística como Assunto , Artérias Umbilicais/patologia
14.
Phys Rev Lett ; 117(19): 192501, 2016 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-27858422

RESUMO

We report the first measurement of the flux-averaged cross section for charged current coherent π^{+} production on carbon for neutrino energies less than 1.5 GeV, and with a restriction on the final state phase space volume in the T2K near detector, ND280. Comparisons are made with predictions from the Rein-Sehgal coherent production model and the model by Alvarez-Ruso et al., the latter representing the first implementation of an instance of the new class of microscopic coherent models in a neutrino interaction Monte Carlo event generator. We observe a clear event excess above background, disagreeing with the null results reported by K2K and SciBooNE in a similar neutrino energy region. The measured flux-averaged cross sections are below those predicted by both the Rein-Sehgal and Alvarez-Ruso et al.

15.
Phys Rev Lett ; 116(18): 181801, 2016 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-27203315

RESUMO

T2K reports its first measurements of the parameters governing the disappearance of ν[over ¯]_{µ} in an off-axis beam due to flavor change induced by neutrino oscillations. The quasimonochromatic ν[over ¯]_{µ} beam, produced with a peak energy of 0.6 GeV at J-PARC, is observed at the far detector Super-Kamiokande, 295 km away, where the ν[over ¯]_{µ} survival probability is expected to be minimal. Using a data set corresponding to 4.01×10^{20} protons on target, 34 fully contained µ-like events were observed. The best-fit oscillation parameters are sin^{2}(θ[over ¯]_{23})=0.45 and |Δm[over ¯]_{32}^{2}|=2.51×10^{-3} eV^{2} with 68% confidence intervals of 0.38-0.64 and 2.26-2.80×10^{-3} eV^{2}, respectively. These results are in agreement with existing antineutrino parameter measurements and also with the ν_{µ} disappearance parameters measured by T2K.

17.
Osteoarthritis Cartilage ; 23(11): 1858-64, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26028139

RESUMO

OBJECTIVE: The aim of this study was to examine the osteoarthritis (OA)-related structural changes associated with histological synovitis in end-stage knee OA patients. METHODS: Forty end-stage knee OA patients (female: 88%, mean age: 71.8 y) were enrolled. All participants underwent 3.0-T MRI. The structural changes, such as cartilage morphology, subchondral bone marrow lesion (BML), subchondral bone cyst (SBC), subchondral bone attrition (SBA), osteophytes, meniscal lesion and synovitis, were scored using the whole-organ MRI scoring (WORMS) method. Synovial samples were obtained from five regions of interest (ROIs) of the knee joint during total joint replacement surgery. The associations between the histological synovitis score (HSS) and WORMS or the synovial expression levels of cyclooxygenase (COX)-2, interleukin (IL)-1ß, IL-6 and transforming growth factor (TGF)-ß were examined using Spearman's correlation coefficient. RESULTS: Among the seven OA-related structural changes, the BML, SBC, SBA and synovitis were significantly associated with the HSS (r = 0.33, 0.35, 0.48 and 0.36, respectively), while other morphological changes were not. Although synovial COX-2, IL-1ß or IL-6 expression levels were not associated with the HSS, the synovial TGF-ß expression levels were associated with the HSS. CONCLUSION: The presence of BML, SBC and SBA was associated with histological synovitis in end-stage knee OA patients.


Assuntos
Cistos Ósseos/patologia , Doenças da Medula Óssea/patologia , Medula Óssea/patologia , Cartilagem Articular/patologia , Imageamento por Ressonância Magnética/métodos , Osteoartrite do Joelho/patologia , Sinovite/patologia , Idoso , Cistos Ósseos/complicações , Cistos Ósseos/metabolismo , Doenças da Medula Óssea/complicações , Doenças da Medula Óssea/metabolismo , Estudos Transversais , Citocinas/biossíntese , Feminino , Humanos , Imuno-Histoquímica , Masculino , Osteoartrite do Joelho/complicações , Osteoartrite do Joelho/metabolismo , Líquido Sinovial/metabolismo , Sinovite/etiologia , Sinovite/metabolismo
18.
Phys Rev Lett ; 115(12): 121802, 2015 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-26430986

RESUMO

The OPERA experiment was designed to search for ν_{µ}→ν_{τ} oscillations in appearance mode, i.e., by detecting the τ leptons produced in charged current ν_{τ} interactions. The experiment took data from 2008 to 2012 in the CERN Neutrinos to Gran Sasso beam. The observation of the ν_{µ}→ν_{τ} appearance, achieved with four candidate events in a subsample of the data, was previously reported. In this Letter, a fifth ν_{τ} candidate event, found in an enlarged data sample, is described. Together with a further reduction of the expected background, the candidate events detected so far allow us to assess the discovery of ν_{µ}→ν_{τ} oscillations in appearance mode with a significance larger than 5σ.

20.
Phys Rev Lett ; 112(6): 061802, 2014 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-24580687

RESUMO

The T2K experiment has observed electron neutrino appearance in a muon neutrino beam produced 295 km from the Super-Kamiokande detector with a peak energy of 0.6 GeV. A total of 28 electron neutrino events were detected with an energy distribution consistent with an appearance signal, corresponding to a significance of 7.3σ when compared to 4.92±0.55 expected background events. In the Pontecorvo-Maki-Nakagawa-Sakata mixing model, the electron neutrino appearance signal depends on several parameters including three mixing angles θ12, θ23, θ13, a mass difference Δm(32)(2) and a CP violating phase δ(CP). In this neutrino oscillation scenario, assuming |Δm(32)(2)|=2.4×10(-3) eV(2), sin(2)θ(23)=0.5, and Δm322>0 (Δm(32)(2)<0), a best-fit value of sin(2)2θ(13)=0.140(-0.032)(+0.038) (0.170(-0.037)(+0.045)) is obtained at δ(CP)=0. When combining the result with the current best knowledge of oscillation parameters including the world average value of θ(13) from reactor experiments, some values of δ(CP) are disfavored at the 90% C.L.

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