Search for Boosted Dark Matter in COSINE-100.

We search for energetic electron recoil signals induced by boosted dark matter (BDM) from the galactic center using the COSINE-100 array of NaI(Tl) crystal detectors at the Yangyang Underground Laboratory. The signal would be an excess of events with energies above 4 MeV over the well-understood background. Because no excess of events are observed in a 97.7 kg·yr exposure, we set limits on BDM interactions under a variety of hypotheses. Notably, we explored the dark photon parameter space, leading to competitive limits compared to direct dark photon search experiments, particularly for dark photon masses below 4 MeV and considering the invisible decay mode. Furthermore, by comparing our results with a previous BDM search conducted by the Super-Kamionkande experiment, we found that the COSINE-100 detector has advantages in searching for low-mass dark matter. This analysis demonstrates the potential of the COSINE-100 detector to search for MeV electron recoil signals produced by the dark sector particle interactions.

Search for a Dark Matter-Induced Annual Modulation Signal in NaI(Tl) with the COSINE-100 Experiment.

We present new constraints on the dark matter-induced annual modulation signal using 1.7 years of COSINE-100 data with a total exposure of 97.7 kg yr. The COSINE-100 experiment, consisting of 106 kg of NaI(Tl) target material, is designed to carry out a model-independent test of DAMA/LIBRA's claim of WIMP discovery by searching for the same annual modulation signal using the same NaI(Tl) target. The crystal data show a 2.7 cpd/kg/keV background rate on average in the 2-6 keV energy region of interest. Using a χ-squared minimization method we observe best fit values for modulation amplitude and phase of 0.0092±0.0067 cpd/kg/keV and 127.2±45.9 d, respectively.

First Direct Search for Inelastic Boosted Dark Matter with COSINE-100.

A search for inelastic boosted dark matter (IBDM) using the COSINE-100 detector with 59.5 days of data is presented. This relativistic dark matter is theorized to interact with the target material through inelastic scattering with electrons, creating a heavier state that subsequently produces standard model particles, such as an electron-positron pair. In this study, we search for this electron-positron pair in coincidence with the initially scattered electron as a signature for an IBDM interaction. No excess over the predicted background event rate is observed. Therefore, we present limits on IBDM interactions under various hypotheses, one of which allows us to explore an area of the dark photon parameter space that has not yet been covered by other experiments. This is the first experimental search for IBDM using a terrestrial detector.

Background model for the NaI(Tl) crystals in COSINE-100.

The COSINE-100 dark matter search experiment is an array of NaI(Tl) crystal detectors located in the Yangyang Underground Laboratory (Y2L). To understand measured backgrounds in the NaI(Tl) crystals we have performed Monte Carlo simulations using the Geant4 toolkit and developed background models for each crystal that consider contributions from both internal and external sources, including cosmogenic nuclides. The background models are based on comparisons of measurement data with Monte Carlo simulations that are guided by a campaign of material assays and are used to evaluate backgrounds and identify their sources. The average background level for the six crystals (70 kg total mass) that are studied is 3.5 counts/day/keV/kg in the (2-6) keV energy interval. The dominant contributors in this energy region are found to be 210 Pb and 3 H.

Sterile Neutrino Search at the NEOS Experiment.

An experiment to search for light sterile neutrinos is conducted at a reactor with a thermal power of 2.8 GW located at the Hanbit nuclear power complex. The search is done with a detector consisting of a ton of Gd-loaded liquid scintillator in a tendon gallery approximately 24 m from the reactor core. The measured antineutrino event rate is 1976 per day with a signal to background ratio of about 22. The shape of the antineutrino energy spectrum obtained from the eight-month data-taking period is compared with a hypothesis of oscillations due to active-sterile antineutrino mixing. No strong evidence of 3+1 neutrino oscillation is found. An excess around the 5 MeV prompt energy range is observed as seen in existing longer-baseline experiments. The mixing parameter sin^{2}2θ_{14} is limited up to less than 0.1 for Δm_{41}^{2} ranging from 0.2 to 2.3 eV^{2} with a 90% confidence level.

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}.

Placental deposition of C-reactive protein is a common feature of human pregnancy.

This study examined the occurrence of placental C-reactive protein (CRP) in normal pregnancy with term delivery, spontaneous preterm delivery (sPTD), preeclampsia, and miscarriage. CRP immunoreactivity was detected in the syncytiotrophoblast. The immunopositive rate was significantly higher in sPTD than preeclampsia. The CRP immunopositive rate was also higher in acute chorioamnionitis than those without and showed a good correlation with the maternal serum CRP concentration. CRP mRNA expression was not detected in human and mouse placentas or choriocarcinoma cells. CRP may play a role in the pathological and physiological states of pregnancy.

Pharmacokinetics of amoxicillin trihydrate in cultured olive flounder (Paralichthys olivaceus).

The study was aimed at investigating the pharmacokinetics of amoxicillin trihydrate (AMOX) in olive flounder (Paralichthys olivaceus) following oral, intramuscular, and intravenous administration, using high-performance liquid chromatography following. The maximum plasma concentration (Cmax ), following oral administration of 40 and 80 mg/kg body weight (b.w.), AMOX was 1.14 (Tmax , 1.7 h) and 0.76 µg/mL (Tmax , 1.6 h), respectively. Intramuscular administration of 30 and 60 mg/kg of AMOX resulted in Cmax values of 4 and 4.3 µg/mL, respectively, with the corresponding Tmax values of 29 and 38 h. Intravenous administration of 6 mg/kg AMOX resulted in a Cmax of 9 µg/mL 2 h after administration. Following oral administration of 40 and 80 mg/kg AMOX, area under the curve (AUC) values were 52.257 and 41.219 µg/mL·h, respectively. Intramuscular 30 and 60 mg/kg doses resulted in AUC values of 370.274 and 453.655 µg/mL·h, respectively, while the AUC following intravenous administration was 86.274 µg/mL·h. AMOX bioavailability was calculated to be 9% and 3.6% following oral administration of 40 and 80 mg/kg, respectively, and the corresponding values following intramuscular administration were 86% and 53%. In conclusion, this study demonstrated high bioavailability of AMOX following oral administration in olive flounder.

Feasibility of using auto Mod-MPI system, a novel technique for automated measurement of fetal modified myocardial performance index.

OBJECTIVES: To evaluate the reproducibility of measurement of the fetal left modified myocardial performance index (Mod-MPI) determined using a novel automated system. METHODS: This was a prospective study of 116 ultrasound examinations from 110 normal singleton pregnancies at 12 + 1 to 37 + 1 weeks' gestation. Two experienced operators each measured the left Mod-MPI twice manually and twice automatically using the Auto Mod-MPI system. Intra- and interoperator reproducibility were assessed using intraclass correlation coefficients (ICCs) and the manual and automated measurements obtained by the more experienced operator were compared using Bland-Altman plots and ICCs. RESULTS: Both operators successfully measured the left Mod-MPI in all cases using the Auto Mod-MPI system. For both operators, intraoperator reproducibility was higher when performing automated measurements (ICC = 0.967 and 0.962 for Operators 1 and 2, respectively) than when performing manual measurements (ICC = 0.857 and 0.856 for Operators 1 and 2, respectively). Interoperator agreement was also better for automated than for manual measurements (ICC = 0.930 vs 0.723, respectively). There was good agreement between the automated and manual values measured by the more experienced operator. CONCLUSIONS: The Auto Mod-MPI system is a reliable technique for measuring fetal left Mod-MPI and demonstrates excellent reproducibility.

Ultra-low gamma-ray measurement system for neutrinoless double beta decay.

An experiment for the detection of 0νß(+)/EC and 0νEC/EC in 92Mo nuclei has been carried out with a scintillating crystal, CaMoO4, in coincidence with the HPGe detector. We study the background events inside the event selection window for 0ν ß(+)/EC decays of CaMoO4 detector. For 51.2 days of data taking period, we didn't observe any event in the neutrinoless EC/EC decay event window. The (92)Mo 0νß(+)/EC decay half-life limit was set to 0.61×10(20) years with a 90% confidence by method of Feldman and Cousins. This ultra-low gamma ray measurement utilizing coincidence technique can be used for the resonant EC/EC decay process of some nuclei which is potentially important for neutrinoless double beta decay process.

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.

Influence of central glia on spiral ganglion neuron neurite growth.

Spiral ganglion neurons (SGNs) extend processes that interact with Schwann cells (SCs) and with oligodendrocytes (OLs) and astrocytes (ACs). We investigated the ability of these glial cells to support SGN neurite growth. In the presence of cultured ACs, OLs and SCs, SGN neurites tended to follow SCs and OLs and cross-over ACs. Most neurites initially followed the type of glial cell on which the neuronal cell body was found. To determine the influence of homogeneous populations of glia on neurite growth, SG explants were plated on cultured SCs, ACs or OLs. The number of neurites/explant extending onto SCs (463.89±16.25) was significantly greater than the number extending onto ACs (111.38±38.73) or OLs (6.75±2.21), indicating that populations of central glia inhibit SGN neurite growth. Treatment with cell-permeant cpt-cAMP or forskolin (FSK) each significantly increased the number of neurites on OLs (133.54±25.59 and 292.25±83.57, respectively). cpt-cAMP and FSK each also increased the number of neurites on ACs (213.19±36.06 and 208.64±59.25, respectively), however the difference was not significant compared with control. The neurites on ACs and OLs failed to grow radially in a well-fasciculated pattern as on SCs. In explants plated on the borders of cultured OL-SC or AC-SC groups, more neurites extended onto SCs compared with OLs and ACs. Conditioned media (CM) from OL or AC cultures did not reduce neurite length, implying that the inhibition of neurite growth by central glia is not due to soluble factors. Taken together, these results demonstrate that homogeneous populations of central glia inhibit SGN neurite growth.

Clinical characteristics and audiological significance of spontaneous otoacoustic emissions in tinnitus patients with normal hearing.

OBJECTIVE: To define the clinical and audiological features of normal-hearing tinnitus patients with spontaneous otoacoustic emissions, and to evaluate the role of spontaneous otoacoustic emissions in tinnitus generation. MATERIALS AND METHODS: Thirty-two patients with spontaneous otoacoustic emissions were compared with 29 patients without spontaneous otoacoustic emissions, regarding clinical and audiological aspects. RESULTS: The mean age of the study group subjects was significantly lower, and they experienced the kindling effect less frequently than the control group. The mean tinnitus handicap inventory score of the study group was considerably higher than that of the controls, although the difference was not statistically significant. The study group had significantly quieter tinnitus, and higher transient evoked and distortion product otoacoustic emission responses, compared with the control group. CONCLUSIONS: Normal-hearing tinnitus patients with spontaneous otoacoustic emissions have different clinical and audiological characteristics, compared with those without spontaneous otoacoustic emissions. Appropriate evaluation and treatment should be considered at an early stage in these patients.

Improved search for nu(mu) --> nu(e) oscillation in a long-baseline accelerator experiment.

We performed an improved search for nu(mu) --> nu(e) oscillation with the KEK to Kamioka (K2K) long-baseline neutrino oscillation experiment, using the full data sample of 9.2 x 10(19) protons on target. No evidence for a nu(e) appearance signal was found, and we set bounds on the nu(mu) --> nu(e) oscillation parameters. At Deltam(2)=2.8 x 10(-3) eV(2), the best-fit value of the K2Knu(mu) disappearance analysis, we set an upper limit of sin(2)2theta(mue) < 0.13 at a 90% confidence level.

Search for coherent charged pion production in neutrino-carbon interactions.

We report the result from a search for charged-current coherent pion production induced by muon neutrinos with a mean energy of 1.3 GeV. The data are collected with a fully active scintillator detector in the K2K long-baseline neutrino oscillation experiment. No evidence for coherent pion production is observed, and an upper limit of is set on the cross section ratio of coherent pion production to the total charged-current interaction at 90% confidence level. This is the first experimental limit for coherent charged pion production in the energy region of a few GeV.

Evidence for muon neutrino oscillation in an accelerator-based experiment.

We present results for nu(mu) oscillation in the KEK to Kamioka (K2K) long-baseline neutrino oscillation experiment. K2K uses an accelerator-produced nu(mu) beam with a mean energy of 1.3 GeV directed at the Super-Kamiokande detector. We observed the energy-dependent disappearance of nu(mu), which we presume have oscillated to nu(tau). The probability that we would observe these results if there is no neutrino oscillation is 0.0050% (4.0 sigma).

Search for electron neutrino appearance in a 250 km long-baseline experiment.

We present a search for electron neutrino appearance from accelerator-produced muon neutrinos in the K2K long-baseline neutrino experiment. One candidate event is found in the data corresponding to an exposure of 4.8 x 10(19) protons on target. The expected background in the absence of neutrino oscillations is estimated to be 2.4+/-0.6 events and is dominated by misidentification of events from neutral current pi(0) production. We exclude the nu(micro) to nu(e) oscillations at 90% C.L. for the effective mixing angle in the 2-flavor approximation of sin((2)2theta(microe)( approximately 1/2sin((2)2theta(13))>0.15 at Deltam(2)(microe)=2.8 x 10(-3) eV(2), the best-fit value of the nu(micro) disappearance analysis in K2K. The most stringent limit of sin((2)2theta(microe)<0.09 is obtained at Deltam(2)(microe)=6 x 10(-3) eV(2).

Indications of neutrino oscillation in a 250 km long-baseline experiment.

The K2K experiment observes indications of neutrino oscillation: a reduction of nu(mu) flux together with a distortion of the energy spectrum. Fifty-six beam neutrino events are observed in Super-Kamiokande (SK), 250 km from the neutrino production point, with an expectation of 80.1(+6.2)(-5.4). Twenty-nine one ring mu-like events are used to reconstruct the neutrino energy spectrum, which is better matched to the expected spectrum with neutrino oscillation than without. The probability that the observed flux at SK is explained by statistical fluctuation without neutrino oscillation is less than 1%.

Effect of inhibitor of tumor necrosis factor-alpha on experimental otitis media with effusion.

Tumor necrosis factor (TNF)-alpha is important in the pathogenesis of otitis media with effusion (OME). The purpose of this study was to determine the effect of TNF-alpha antagonist on the outcome of lipopolysaccharide (LPS)-induced OME in rats. Otitis media was induced by injecting Pseudomonas aeruginosa LPS transtympanically. Another (combination) group was pretreated with TNF-alpha antagonist, soluble TNF receptor type I (sTNF RI), before transtympanic injection of LPS. Saline and phosphate-buffered saline solutions were used as controls. Twelve hours after the transtympanic injection, otoscopic examination and aspiration of middle ear effusion (MEE) were done. The temporal bones in each group were examined histopathologically, and the vascular permeability of the middle ear mucosa was measured by the Evans blue vital dye technique. In the LPS and combination groups, MEE developed in 90% and 0% of ears, respectively. The combination group showed less inflammation, less mucosal thickening, and significantly decreased vascular permeability as compared to the LPS group. Transtympanic administration of sTNF RI appears to suppress the development of LPS-induced OME. This study suggests that TNF-alpha antagonist, along with antibiotics, may have an adjunctive role in the future treatment of MEE.

Effect of dietary restriction on age-related increase of liver susceptibility to peroxidation in rats.

Dietary restriction (DR) increases life span and decreases age-related diseases in experimental animals. It has received a great deal of attention in connection with the relationship between aging, nutrition, and oxidative stress because oxidative injury in several organ systems is a prominent feature in aging. We investigated the possibility that DR can protect vulnerable liver lipids against age-related increases of peroxidation. Male Fischer 344 rats fed ad libitum (AL) or dietarily restricted (maintained on 60% of AL food intake) were killed by decapitation at 4 (young) or 12 mon (adult) of age. Phosphatidylcholine hydroperoxide (PCOOH) concentration of liver was determined using a chemiluminescent high-performance liquid chromatographic method. Liver PCOOH increased with age in adult rats, but less of an increase of PCOOH was seen in DR rats, which is consistent with results on production of thiobarbituric acid-reactive substances and oxygen-derived free radicals. No significant differences were found in liver superoxide dismutase and catalase activity between AL and DR groups of young and adult rats. Liver triglyceride and cholesterol contents were lower in DR than AL rats at 12 mon. Fatty acid compositions of phosphatidylcholine and phosphatidylethanolamine indicated that the ratio of (20:3n-6 + 20:4n-6)/18:2n-6, an index of linoleic acid (18:2n-6) desaturation, was lower in DR than in AL rats. We concluded that DR suppresses age-related oxidative damage in liver by modulating the amount of lipid as well as fatty acid composition.