Search for Sub-eV Sterile Neutrinos at RENO.

We report a search result for a light sterile neutrino oscillation with roughly 2200 live days of data in the RENO experiment. The search is performed by electron antineutrino (ν[over ¯]_{e}) disappearance taking place between six 2.8 GW_{th} reactors and two identical detectors located at 294 m (near) and 1383 m (far) from the center of the reactor array. A spectral comparison between near and far detectors can explore reactor ν[over ¯]_{e} oscillations to a light sterile neutrino. An observed spectral difference is found to be consistent with that of the three-flavor oscillation model. This yields limits on sin^{2}2θ_{14} in the 10^{-4}≲|Δm_{41}^{2}|≲0.5 eV^{2} region, free from reactor ν[over ¯]_{e} flux and spectrum uncertainties. The RENO result provides the most stringent limits on sterile neutrino mixing at |Δm_{41}^{2}|≲0.002 eV^{2} using the ν[over ¯]_{e} disappearance channel.

Fuel-Composition Dependent Reactor Antineutrino Yield at RENO.

We report a fuel-dependent reactor electron antineutrino (ν[over ¯]_{e}) yield using six 2.8 GW_{th} reactors in the Hanbit nuclear power plant complex, Yonggwang, Korea. The analysis uses 850 666 ν[over ¯]_{e} candidate events with a background fraction of 2.0% acquired through inverse beta decay (IBD) interactions in the near detector for 1807.9 live days from August 2011 to February 2018. Based on multiple fuel cycles, we observe a fuel ^{235}U dependent variation of measured IBD yields with a slope of (1.51±0.23)×10^{-43} cm^{2}/fission and measure a total average IBD yield of (5.84±0.13)×10^{-43} cm^{2}/fission. The hypothesis of no fuel-dependent IBD yield is ruled out at 6.6σ. The observed IBD yield variation over ^{235}U isotope fraction does not show significant deviation from the Huber-Mueller (HM) prediction at 1.3 σ. The measured fuel-dependent variation determines IBD yields of (6.15±0.19)×10^{-43} and (4.18±0.26)×10^{-43} cm^{2}/fission for two dominant fuel isotopes ^{235}U and ^{239}Pu, respectively. The measured IBD yield per ^{235}U fission shows the largest deficit relative to the HM prediction. Reevaluation of the ^{235}U IBD yield per fission may mostly solve the reactor antineutrino anomaly (RAA) while ^{239}Pu is not completely ruled out as a possible contributor to the anomaly. We also report a 2.9 σ correlation between the fractional change of the 5 MeV excess and the reactor fuel isotope fraction of ^{235}U.

Measurement of Reactor Antineutrino Oscillation Amplitude and Frequency at RENO.

The RENO experiment reports more precisely measured values of θ_{13} and |Δm_{ee}^{2}| using ∼2200 live days of data. The amplitude and frequency of reactor electron antineutrino (ν[over ¯]_{e}) oscillation are measured by comparing the prompt signal spectra obtained from two identical near and far detectors. In the period between August 2011 and February 2018, the far (near) detector observed 103 212 (850 666) ν[over ¯]_{e} candidate events with a background fraction of 4.8% (2.0%). A clear energy and baseline dependent disappearance of reactor ν[over ¯]_{e} is observed in the deficit of the measured number of ν[over ¯]_{e}. Based on the measured far-to-near ratio of prompt spectra, we obtain sin^{2}2θ_{13}=0.0896±0.0048(stat)±0.0047(syst) and |Δm_{ee}^{2}|=[2.68±0.12(stat)±0.07(syst)]×10^{-3} eV^{2}.

Observation of Energy and Baseline Dependent Reactor Antineutrino Disappearance in the RENO Experiment.

The RENO experiment has analyzed about 500 live days of data to observe an energy dependent disappearance of reactor ν[over ¯]_{e} by comparing their prompt signal spectra measured in two identical near and far detectors. In the period between August of 2011 and January of 2013, the far (near) detector observed 31 541 (290 775) electron antineutrino candidate events with a background fraction of 4.9% (2.8%). The measured prompt spectra show an excess of reactor ν[over ¯]_{e} around 5 MeV relative to the prediction from a most commonly used model. A clear energy and baseline dependent disappearance of reactor ν[over ¯]_{e} is observed in the deficit of the observed number of ν[over ¯]_{e}. Based on the measured far-to-near ratio of prompt spectra, we obtain sin^{2}2θ_{13}=0.082±0.009(stat)±0.006(syst) and |Δm_{ee}^{2}|=[2.62_{-0.23}^{+0.21}(stat)_{-0.13}^{+0.12}(syst)]×10^{-3} eV^{2}.

The competitive growth of cubic domains in Ti(1-x)AlxN films studied by diffraction anomalous near-edge structure spectroscopy.

Titanium and aluminium nitride films deposited by magnetron sputtering generally grow as columnar domains made of oriented nanocrystallites with cubic or hexagonal symmetry depending on Al content, which are embedded in more disordered grain boundaries. The substitution of Al atoms for Ti in the cubic lattice of the films improves their resistance to wear and oxidation, allowing their use as protective coatings. Ti K-edge X-ray absorption spectroscopy, which probes both crystallized and more disordered grain boundaries, and X-ray diffraction anomalous fine structure, which is sensitive to short- and long-range order within a given crystallized domain, are carried out on a set of Ti(1-x)AlxN films deposited by magnetron sputtering on Si substrates. Attention is paid to the shape of the pre-edge region, which is sensitive to the symmetry of the site occupied by Ti atoms, either octahedral in face-centred-cubic Ti-rich (TiN, Ti0.54Al0.46N) samples or tetrahedral in hexagonal-close-packed Al-rich (Ti0.32Al0.68N) films. In order to obain information on the titanium environment in the well crystallized areas, subtraction of the smooth part of the energy-dependent structure factor for the Bragg reflections is applied to the pre-edge region of the diffraction anomalous data in order to restore their spectroscopic appearance. A flat pre-edge is related to the typical octahedral environment of Ti atoms for cubic reflections. The difference observed between pre-edge spectra associated with face-centred-cubic 200 and 111 Bragg reflections of Ti0.54Al0.46N is assigned to Ti enrichment of 111 large well ordered domains compared with the more disordered 200 ones. The sharp peak observed in the spectrum recorded from the hexagonal 002 peak of Ti0.32Al0.68N can be regarded as a standard for the pure tetrahedral Ti environment in hexagonal-close-packed nitride.

Observation of reactor electron antineutrinos disappearance in the RENO experiment.

The RENO experiment has observed the disappearance of reactor electron antineutrinos, consistent with neutrino oscillations, with a significance of 4.9 standard deviations. Antineutrinos from six 2.8 GW(th) reactors at the Yonggwang Nuclear Power Plant in Korea, are detected by two identical detectors located at 294 and 1383 m, respectively, from the reactor array center. In the 229 d data-taking period between 11 August 2011 and 26 March 2012, the far (near) detector observed 17102 (154088) electron antineutrino candidate events with a background fraction of 5.5% (2.7%). The ratio of observed to expected numbers of antineutrinos in the far detector is 0.920±0.009(stat)±0.014(syst). From this deficit, we determine sin(2)2θ(13)=0.113±0.013(stat)±0.019(syst) based on a rate-only analysis.

High disease activity at baseline does not prevent a remission in patients with systemic lupus erythematosus.

OBJECTIVE: To evaluate the utility of systemic lupus erythematosus (SLE) initial clinical manifestations and the SLE Disease Activity Index (SLEDAI) for identifying patients who will have a remission. METHODS: We studied 100 SLE patients (85 females, 15 males) and identified all patients who had remission (defined as at least one continuous year during which lack of disease activity permitted withdrawal of all treatment to suppress general lupus activity of a particular clinical manifestation). Changes in laboratory parameters without clinical activity, thus not requiring treatment, did not invalidate remission. We did not include any patient who had never required treatment. We evaluated the SLEDAI values and the main SLE manifestations at the time of diagnosis of SLE, and also every 3 months during the first year of disease. RESULTS: Twenty-four of the 100 SLE patients achieved remission that occurred a mean of 64 months after the diagnosis. They remained in remission for a mean of 55 months. There were no statistical differences in SLEDAI values and the initial manifestations (including renal and cerebral) between patients who reached remission and those who did not. The patients who have a higher SLEDAI score take longer to achieve remission. CONCLUSION: SLE patients with severe initial clinical manifestations and higher SLEDAI values may achieve clinical remission.

Mild presentation of systemic lupus erythematosus in elderly patients assessed by SLEDAI. SLE Disease Activity Index.

OBJECTIVE: Systemic lupus erythematosus (SLE) predominantly affects young patients. SLE starting in later life has a clinical presentation different than in younger patients. We have used the SLE Disease Activity Index (SLEDAI) to explore the relationship between age of onset and disease activity. METHODS: We selected all patients controlled in our hospital at the moment of clinical diagnosis of SLE (100 patients; 85 females and 15 males). They were classified in two groups: those with early onset (>50 y) and those with late onset (>50 y) based on their age at the moment of clinical diagnosis of SLE. RESULTS: In 12 patients the onset of SLE was >50 y (10 females and two males; mean age 59 y). The early onset patients had significantly higher SLEDAI values at the presentation and during the first year of disease with respect to elderly patients. Antibodies to DNA and hypocomplementemia were detected more often in younger patients. CONCLUSION: Our results confirm using SLEDAI, that the lupus of the elderly patients is a distinct clinical subgroup with a milder course of disease.

Effect of hematocrit on blood pressure via hyperviscosity.

Increase in blood viscosity, defined as resistance to flow, is one factor in hypertension and atherosclerosis that contributes to the morbidity and mortality associated with tissue ischemia. In this research we evaluated the effect of hematocrit on increasing viscosity, and possible related changes in blood pressure, flow rate, and the equivalent physiologic compensation ratios. Blood samples were taken from 32 healthy individuals and centrifuged for 5 min at 3000 rpm to obtain 2.5 mL of erythrocyte mass from each. Then, at each step 0.5 mL of plasma was consecutively added in a total of 17 steps. The resultant hematocrit and viscosity changes were measured. Viscosity measurement was performed by capillary viscometer. The results were evaluated by the Student t test. It was observed that in the range of 60.16% and 25.32%, a 10.99% increase of hematocrit produced an increase of 1 unit relative viscosity, which means approximately a 20% increase in blood viscosity for a healthy individual. According to Poiseuille's equation, with a constant vessel length, if viscosity is increased by 20%, the decrease in blood flow rate will be 16.67% (100/120 = 83.33%; 100 - 83.33 = 16.67%). For the physiologic compensation of 20% increased viscosity, blood pressure increase will be 20% or vasodilation will be 4.66% in radius. Atherosclerotic and some healthy vessels with little vasodilatory capacities might benefit from treatment modalities to decrease the viscosity by hemodilution.

[Hepatitis A, B, and C in an occupational center for the mentally handicapped]. / Hepatitis A, B y C en un centro ocupacional para disminuidos psíquicos.

BACKGROUND: Estimation of prevalence of serologic markers of viral hepatitis A, B and C in students and staff of an occupational centre in Castellón (Spain). METHODS: Serologic markers of hepatitis A (IgG anti-HAV) and B (HBsAg, anti-HBe, anti-HBc, anti-HBs) were detected by radioimmunoassay (RIA) and serologic markers of hepatitis C (anti-HCV) by immunoradiometric assay (IRMA). Ninety per cent of students (54/60) and 80% of staff (8/10) participated. RESULTS: The prevalence of IgG anti-HVA was 55.6% in students and 75% in staff, increasing with age. Considering persons not vaccinated against hepatitis B, the prevalence of serologic markers hepatitis B was 18.5% in students, two HBsAg and anti-HBe positive, and nobody in staff. Serologic markers hepatitis B was associated with duration of stay institutions for mentally handicapped. None of the center was positive for anti-HCV. CONCLUSIONS: Viral hepatitis prevalences present notable differences. To maintain a serological surveillance of these diseases is important to control and prevention.

[Epidemic outbreaks of salmonellosis caused by eating eggs]. / Brotes epidémicos de salmonelosis por consumo de huevos.

BACKGROUND: Investigation of outbreaks of foodborne infections (OFI) by Salmonella associated with the consumption of hens' eggs from a same classification center of Castellón, and determination of origin, extension and to take measures of control and prevention. METHODS: Descriptive and case-control studies, microbiologic analysis of feces, suspicious foods, and eggs. Sampling of eggs in the classification center for estimation the prevalence of Salmonlla. RESULTS: In 1992, 5 OFI were detected, 4 collective (1 school, 2 restaurants, and 1 residence) and 1 at home, by the consumption of food prepared with eggs: fried or boiled eggs, omelette, soufflé, 2 times, and home-made russian salad. Five hundred and forty-five persons were exposed and 364 were studied, with 100 case patients and 16 hospitalized. The range of attack rates was 10.5-87.0%. Samonella enteritidis (3 OFI) and S. typhimurium (3 OFI) were the infectious agents. In February 1993, the prevalence of Salmonella in eggs from the center was 0.26% (4/1.524) (S. enteritidis, 2 isolates, and S. typhimurium, 2 isolate), three on the shell, and one in the yolk. Two farmhouses of the six supplied were infected. CONCLUSIONS: These outbreaks indicate that salmonellosis by egg's consumption are frequent here and investigation of infection sources is necessary.

Cardiac hydatid cyst causing massive pulmonary embolism.

Cardiac hydatid cyst is a rare parasitic disease. Since it may be associated with fatal complications, early diagnosis and treatment of a cardiac hydatid cyst is very important. We present a case with hydatid cyst localized in the right atrium and bilaterally in the lungs, and embolized pulmonary arteries bilaterally. The right atrial cyst localized on the interatrial septum was removed using cardiopulmonary bypass and the cyst in the right pulmonary artery was extracted by an embolectomy catheter. The patient died of pulmonary hypertension and pulmonary insufficiency three months postoperatively.

[Osteonecrosis in systemic lupus erythematosus. Report of 3 cases]. / Osteonecrosis en el lupus eritematoso sistémico. Presentación de tres casos.

We present three cases of patients with systemic lupus erythematosus (SLE) and osteonecrosis or avascular necrosis (AV). Although, the pathogenesis of osteonecrosis is controversial and multifactorial, the glucocorticoids therapy is the most important factor contributing to the lesion. We report the clinical presentation of the three patients. We comment the characteristics of AV, the diagnosis and the treatment of this uncommon complication in SLE patients.

[Antiphospholipid antibodies and epilepsy in patients with systemic lupus erythematosus]. / Anticuerpos antifosfolípido y epilepsia en los pacientes con lupus eritematoso sistémico.

OBJECTIVE: To verify the possible relationship between the presence of antiphospholipid antibodies (APLA) and the presence of epileptic seizures in patients with systemic lupus erythematosus (SLE). METHODS: A total of 168 patients with SLE were studied. Fifteen patients had antecedents of epilepsy which were non attributable to a cause other than SLE. Epilepsy was diagnosed on clinical and electroencephalographic grounds. Antibodies to cardiolipin (CLa) and lupus anticoagulant (LA) were measured. RESULTS: Epileptic seizures were generalized in 13 and partial in two patients. The lupus anticoagulant was positive in 40% of patients with epilepsy compared to 32% in the control group; CLa IgG in 53.5% compared to 65.6%, and CLa IgM in 40% compared to 35.2%. Differences were never statistically significant. Neither when patients with moderate/high CLa levels were studied. Seven patients (40%) had some of the classical manifestations of antiphospholipid syndrome. CONCLUSIONS: No association was found between positive APLA and epilepsy in patients with SLE.

[Epidemic outbreak of hepatitis B from the tattoo in gypsy families]. / Brote epidémico de hepatitis B por tatuaje en familias de étnia gitana.

BACKGROUND: To document an outbreak of Hepatitis B in a gypsy community in the Upper Aragón region, as well as the control measures adopted. METHODS: Documented study of Hepatitis B cases and families, including an epidemiological survey and the determining of hepatitis B viral indicators (MVHB) using immunoenzymatic methods. RESULTS: 84.8% participation (39/45). During the months of February and March 1988, 5 cases of Hepatitis B were detected in a gypsy community in the Upper Aragon region (12.8% attack rate, 5/39), with an average age of 13.0 + 7.3, (4 women and one man). Four of the cases detected had previously undergone tatooing. The fifth case was due to direct transmission from mother to a recently born child. The MVHB study of families showed a further two cases. MVHB rate being 17.9% (7/39). Vaccinations were given to all persons susceptible to the disease. CONCLUSIONS: It is suggested that tatooing could be a significant factor to be considered in relation to the transmission of Hepatitis B in gypsy communities. Due to the high rate of incidence of the disease in this ethnic group, general vaccination is prescribed.

[Herpes-zoster virus infection in patients with systemic lupus erythematosus]. / Infección por virus del herpes zoster en pacientes con lupus eritematoso sistémico.

The prevalence of infection with VZV in 145 patients with SLE was investigated, with a mean follow-up of 7.6 years; its relationship with different variables, particularly with therapy of the underlying disease, was analyzed. Twenty episodes of VZV infection in 19 patients were diagnosed (13.1%). In no case was the therapeutic regime changed nor was worsening of SLE observed. There was neither dissemination of herpes nor superinfection. An increase in the number of VZV infections was observed in patients with SLE under corticosteroid therapy (p = 0.04) and particularly when drug administration was on a daily basis (p = 0.00006). Cytotoxic agents also favored the infection (p = 0.0014). VZV infection is of a benign nature in SLE and its emergence is favored by immunosuppressive agents. The risk is lower if corticosteroid administration is on alternate days. There is no need to decrease therapy for SLE.