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Search for Dark-Matter-Nucleon Interactions via Migdal Effect with DarkSide-50. PHYSICAL REVIEW LETTERS 2023; 130:101001. [PMID: 36962014 DOI: 10.1103/physrevlett.130.101001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2022] [Revised: 12/23/2022] [Accepted: 02/07/2023] [Indexed: 06/18/2023]
Abstract
Dark matter elastic scattering off nuclei can result in the excitation and ionization of the recoiling atom through the so-called Migdal effect. The energy deposition from the ionization electron adds to the energy deposited by the recoiling nuclear system and allows for the detection of interactions of sub-GeV/c^{2} mass dark matter. We present new constraints for sub-GeV/c^{2} dark matter using the dual-phase liquid argon time projection chamber of the DarkSide-50 experiment with an exposure of (12 306±184) kg d. The analysis is based on the ionization signal alone and significantly enhances the sensitivity of DarkSide-50, enabling sensitivity to dark matter with masses down to 40 MeV/c^{2}. Furthermore, it sets the most stringent upper limit on the spin independent dark matter nucleon cross section for masses below 3.6 GeV/c^{2}.
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Search for Dark Matter Particle Interactions with Electron Final States with DarkSide-50. PHYSICAL REVIEW LETTERS 2023; 130:101002. [PMID: 36962032 DOI: 10.1103/physrevlett.130.101002] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2022] [Accepted: 01/06/2023] [Indexed: 06/18/2023]
Abstract
We present a search for dark matter particles with sub-GeV/c^{2} masses whose interactions have final state electrons using the DarkSide-50 experiment's (12 306±184) kg d low-radioactivity liquid argon exposure. By analyzing the ionization signals, we exclude new parameter space for the dark matter-electron cross section σ[over ¯]_{e}, the axioelectric coupling constant g_{Ae}, and the dark photon kinetic mixing parameter κ. We also set the first dark matter direct-detection constraints on the mixing angle |U_{e4}|^{2} for keV/c^{2} sterile neutrinos.
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Erratum: Constraints on dark matter-nucleon effective couplings in the presence of kinematically distinct halo substructures using the DEAP-3600 detector [Phys. Rev. D
102
, 082001 (2020)]. Int J Clin Exp Med 2022. [DOI: 10.1103/physrevd.105.029901] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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First Direct Detection Constraints on Planck-Scale Mass Dark Matter with Multiple-Scatter Signatures Using the DEAP-3600 Detector. PHYSICAL REVIEW LETTERS 2022; 128:011801. [PMID: 35061499 DOI: 10.1103/physrevlett.128.011801] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2021] [Revised: 10/15/2021] [Accepted: 11/16/2021] [Indexed: 06/14/2023]
Abstract
Dark matter with Planck-scale mass (≃10^{19} GeV/c^{2}) arises in well-motivated theories and could be produced by several cosmological mechanisms. A search for multiscatter signals from supermassive dark matter was performed with a blind analysis of data collected over a 813 d live time with DEAP-3600, a 3.3 t single-phase liquid argon-based detector at SNOLAB. No candidate signals were observed, leading to the first direct detection constraints on Planck-scale mass dark matter. Leading limits constrain dark matter masses between 8.3×10^{6} and 1.2×10^{19} GeV/c^{2}, and ^{40}Ar-scattering cross sections between 1.0×10^{-23} and 2.4×10^{-18} cm^{2}. These results are interpreted as constraints on composite dark matter models with two different nucleon-to-nuclear cross section scalings.
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Pulse-shape discrimination against low-energy Ar-39 beta decays in liquid argon with 4.5 tonne-years of DEAP-3600 data. THE EUROPEAN PHYSICAL JOURNAL. C, PARTICLES AND FIELDS 2021; 81:823. [PMID: 34720726 PMCID: PMC8550104 DOI: 10.1140/epjc/s10052-021-09514-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Accepted: 07/30/2021] [Indexed: 06/13/2023]
Abstract
The DEAP-3600 detector searches for the scintillation signal from dark matter particles scattering on a 3.3 tonne liquid argon target. The largest background comes from 39 Ar beta decays and is suppressed using pulse-shape discrimination (PSD). We use two types of PSD estimator: the prompt-fraction, which considers the fraction of the scintillation signal in a narrow and a wide time window around the event peak, and the log-likelihood-ratio, which compares the observed photon arrival times to a signal and a background model. We furthermore use two algorithms to determine the number of photons detected at a given time: (1) simply dividing the charge of each PMT pulse by the mean single-photoelectron charge, and (2) a likelihood analysis that considers the probability to detect a certain number of photons at a given time, based on a model for the scintillation pulse shape and for afterpulsing in the light detectors. The prompt-fraction performs approximately as well as the log-likelihood-ratio PSD algorithm if the photon detection times are not biased by detector effects. We explain this result using a model for the information carried by scintillation photons as a function of the time when they are detected.
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Search for
hep
solar neutrinos and the diffuse supernova neutrino background using all three phases of the Sudbury Neutrino Observatory. Int J Clin Exp Med 2020. [DOI: 10.1103/physrevd.102.062006] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Significant Excess of Electronlike Events in the MiniBooNE Short-Baseline Neutrino Experiment. PHYSICAL REVIEW LETTERS 2018; 121:221801. [PMID: 30547637 DOI: 10.1103/physrevlett.121.221801] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Revised: 09/28/2018] [Indexed: 06/09/2023]
Abstract
The MiniBooNE experiment at Fermilab reports results from an analysis of ν_{e} appearance data from 12.84×10^{20} protons on target in neutrino mode, an increase of approximately a factor of 2 over previously reported results. A ν_{e} charged-current quasielastic event excess of 381.2±85.2 events (4.5σ) is observed in the energy range 200<E_{ν}^{QE}<1250 MeV. Combining these data with the ν[over ¯]_{e} appearance data from 11.27×10^{20} protons on target in antineutrino mode, a total ν_{e} plus ν[over ¯]_{e} charged-current quasielastic event excess of 460.5±99.0 events (4.7σ) is observed. If interpreted in a two-neutrino oscillation model, ν_{μ}→ν_{e}, the best oscillation fit to the excess has a probability of 21.1%, while the background-only fit has a χ^{2} probability of 6×10^{-7} relative to the best fit. The MiniBooNE data are consistent in energy and magnitude with the excess of events reported by the Liquid Scintillator Neutrino Detector (LSND), and the significance of the combined LSND and MiniBooNE excesses is 6.0σ. A two-neutrino oscillation interpretation of the data would require at least four neutrino types and indicate physics beyond the three neutrino paradigm. Although the data are fit with a two-neutrino oscillation model, other models may provide better fits to the data.
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First Results from the DEAP-3600 Dark Matter Search with Argon at SNOLAB. PHYSICAL REVIEW LETTERS 2018; 121:071801. [PMID: 30169081 DOI: 10.1103/physrevlett.121.071801] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2017] [Revised: 05/17/2018] [Indexed: 06/08/2023]
Abstract
This Letter reports the first results of a direct dark matter search with the DEAP-3600 single-phase liquid argon (LAr) detector. The experiment was performed 2 km underground at SNOLAB (Sudbury, Canada) utilizing a large target mass, with the LAr target contained in a spherical acrylic vessel of 3600 kg capacity. The LAr is viewed by an array of PMTs, which would register scintillation light produced by rare nuclear recoil signals induced by dark matter particle scattering. An analysis of 4.44 live days (fiducial exposure of 9.87 ton day) of data taken during the initial filling phase demonstrates the best electronic recoil rejection using pulse-shape discrimination in argon, with leakage <1.2×10^{-7} (90% C.L.) between 15 and 31 keV_{ee}. No candidate signal events are observed, which results in the leading limit on weakly interacting massive particle (WIMP)-nucleon spin-independent cross section on argon, <1.2×10^{-44} cm^{2} for a 100 GeV/c^{2} WIMP mass (90% C.L.).
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SU-F-P-13: NRG Oncology Medical Physics Manpower Survey Quantifying Support Demands for Multi Institutional Clinical Trials. Med Phys 2016. [DOI: 10.1118/1.4955720] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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SU-F-T-599: Volume-Independent Conformity Index for Stereotactic Brain Tumors. Med Phys 2016. [DOI: 10.1118/1.4956784] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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SU-E-T-710: Study of Dosimetric Leaf Gap and Transmission Factor Variations Affecting Common Clinical QA Tools. Med Phys 2015. [DOI: 10.1118/1.4925074] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Case Studies Presenting Dosimetric Uncertainties Using Fuzzy Set Theory. Int J Radiat Oncol Biol Phys 2013. [DOI: 10.1016/j.ijrobp.2013.06.1839] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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SU-E-J-84: Use of Deformation Error Histogram as An Accuracy Indicator for Deformable Image Registration. Med Phys 2013. [DOI: 10.1118/1.4814296] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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SU-E-J-105: Applying Fuzzy Similarity Index and Ground Truth Fuzzy Contour to Evaluate the Segmentation Accuracy. Med Phys 2013. [DOI: 10.1118/1.4814317] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Evaluation of the anxiolytic properties of tetrahydropalmatine, a Corydalis yanhusuo compound, in the male Sprague-Dawley rat. AANA JOURNAL 2011; 79:S75-S80. [PMID: 22403971] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The purpose of this study was to investigate the anxiolytic effects of tetrahydropalmatine (THP) and its potential interaction with the benzodiazepine binding site on the gamma-aminobutyric acid (GABAA) receptor in the male Sprague-Dawley rat. Tetrahydropalmatine (THP), an active component isolated from the Chinese herbal plant Corydalis yanhusuo, is used in Asia for its analgesic, sedative, and hypnotic properties during herbal therapy. Fifty-five rats were assigned to 1 of 5 groups with 11 rats per group: 1) control (vehicle), 2) THP, 3) midazolam, 4) midazolam with THP, and 5) flumazenil with THP. In this study, the elevated plus-maze measured the behavioral components of anxiety and motor movements. The data were analyzed using a 2-tailed multivariate analysis of variance to determine if a significant difference existed followed by the least significant difference post hoc test. The findings suggest that THP, 25 mg/kg, given via intraperitoneal injection, results in significant anxiolysis and decreased motor movements. Furthermore, flumazenil, 3 mg/kg, does not fully antagonize the effects of THP.
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THE AUTHORS REPLY. Am J Epidemiol 2010. [DOI: 10.1093/aje/kwq414] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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A pooled analysis of extremely low-frequency magnetic fields and childhood brain tumors. Am J Epidemiol 2010; 172:752-61. [PMID: 20696650 DOI: 10.1093/aje/kwq181] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Pooled analyses may provide etiologic insight about associations between exposure and disease. In contrast to childhood leukemia, no pooled analyses of childhood brain tumors and exposure to extremely low-frequency magnetic fields (ELF-MFs) have been conducted. The authors carried out a pooled analysis based on primary data (1960-2001) from 10 studies of ELF-MF exposure and childhood brain tumors to assess whether the combined results, adjusted for potential confounding, indicated an association. The odds ratios for childhood brain tumors in ELF-MF exposure categories of 0.1-<0.2 μT, 0.2-<0.4 μT, and ≥0.4 μT were 0.95 (95% confidence interval: 0.65, 1.41), 0.70 (95% CI: 0.40, 1.22), and 1.14 (95% CI: 0.61, 2.13), respectively, in comparison with exposure of <0.1 μT. Other analyses employing alternate cutpoints, further adjustment for confounders, exclusion of particular studies, stratification by type of measurement or type of residence, and a nonparametric estimate of the exposure-response relation did not reveal consistent evidence of increased childhood brain tumor risk associated with ELF-MF exposure. These results provide little evidence for an association between ELF-MF exposure and childhood brain tumors.
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Altered regulation of beta-amylase activity in mutants of Arabidopsis with lesions in starch metabolism. Proc Natl Acad Sci U S A 2010; 86:5830-3. [PMID: 16594057 PMCID: PMC297724 DOI: 10.1073/pnas.86.15.5830] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Three classes of mutants of Arabidopsis thaliana (L.) Heynhold with alterations in starch metabolism were found to have higher levels of leaf amylase activity than the wild type when grown in a 12-hr photoperiod. This effect was dependent upon the developmental stage of the plants and was largely suppressed during growth in continuous light. The various amylolytic activities in crude extracts were separated by electrophoresis in nondenaturing polyacrylamide gels and visualized by activity staining. The increased amylase activity in the mutants was due to an up to 40-fold increase in the activity of an extrachloroplast beta-amylase (EC 3.2.1.2). These observations indicate the existence of a regulatory mechanism that controls the amount of beta-amylase activity in response to fluctuations in photosynthetic carbohydrate metabolism. It is paradoxical that beta-amylase appears to be a highly regulated enzyme, but as yet no physiologically relevant function can be assigned to this enzyme due to the absence of starch in the cytoplasmic compartment of leaf cells.
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Measurement of the ratio of the numu charged-current single-pion production to quasielastic scattering with a 0.8 GeV neutrino beam on mineral oil. PHYSICAL REVIEW LETTERS 2009; 103:081801. [PMID: 19792715 DOI: 10.1103/physrevlett.103.081801] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2009] [Indexed: 05/28/2023]
Abstract
Using high statistics samples of charged-current numu interactions, the MiniBooNE [corrected] Collaboration reports a measurement of the single-charged-pion production to quasielastic cross section ratio on mineral oil (CH2), both with and without corrections for hadron reinteractions in the target nucleus. The result is provided as a function of neutrino energy in the range 0.4 GeV<Enu<2.4 GeV with 11% precision in the region of highest statistics. The results are consistent with previous measurements and the prediction from historical neutrino calculations.
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Search for muon neutrino and antineutrino disappearance in MiniBooNE. PHYSICAL REVIEW LETTERS 2009; 103:061802. [PMID: 19792551 DOI: 10.1103/physrevlett.103.061802] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2009] [Indexed: 05/28/2023]
Abstract
The MiniBooNE Collaboration reports a search for nu_{micro} and nu[over]_{micro} disappearance in the Deltam;{2} region of 0.5-40 eV;{2}. These measurements are important for constraining models with extra types of neutrinos, extra dimensions, and CPT violation. Fits to the shape of the nu_{micro} and nu[over]_{micro} energy spectra reveal no evidence for disappearance at the 90% confidence level (C.L.) in either mode. The test of nu[over]_{micro} disappearance probes a region below Deltam;{2} = 40 eV;{2} never explored before.
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Measurement of numicro and nue events in an off-axis horn-focused neutrino beam. PHYSICAL REVIEW LETTERS 2009; 102:211801. [PMID: 19519094 DOI: 10.1103/physrevlett.102.211801] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2008] [Indexed: 05/27/2023]
Abstract
We report the first observation of off-axis neutrino interactions in the MiniBooNE detector from the NuMI beam line at Fermilab. The MiniBooNE detector is located 745 m from the NuMI production target, at 110 mrad angle (6.3 degrees) with respect to the NuMI beam axis. Samples of charged-current quasielastic numicro and nue interactions are analyzed and found to be in agreement with expectation. This provides a direct verification of the expected pion and kaon contributions to the neutrino flux and validates the modeling of the NuMI off-axis beam.
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Unexplained excess of electronlike events from a 1-GeV neutrino beam. PHYSICAL REVIEW LETTERS 2009; 102:101802. [PMID: 19392103 DOI: 10.1103/physrevlett.102.101802] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2008] [Indexed: 05/27/2023]
Abstract
The MiniBooNE Collaboration observes unexplained electronlike events in the reconstructed neutrino energy range from 200 to 475 MeV. With 6.46x10;{20} protons on target, 544 electronlike events are observed in this energy range, compared to an expectation of 415.2+/-43.4 events, corresponding to an excess of 128.8+/-20.4+/-38.3 events. The shape of the excess in several kinematic variables is consistent with being due to either nu_{e} and nu[over ]_{e} charged-current scattering or nu_{mu} neutral-current scattering with a photon in the final state. No significant excess of events is observed in the reconstructed neutrino energy range from 475 to 1250 MeV, where 408 events are observed compared to an expectation of 385.9+/-35.7 events.
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Independent measurement of the total active 8B solar neutrino flux using an array of 3He proportional counters at the Sudbury Neutrino Observatory. PHYSICAL REVIEW LETTERS 2008; 101:111301. [PMID: 18851271 DOI: 10.1103/physrevlett.101.111301] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2008] [Indexed: 05/26/2023]
Abstract
The Sudbury Neutrino Observatory (SNO) used an array of 3He proportional counters to measure the rate of neutral-current interactions in heavy water and precisely determined the total active (nu_x) 8B solar neutrino flux. This technique is independent of previous methods employed by SNO. The total flux is found to be 5.54_-0.31;+0.33(stat)-0.34+0.36(syst)x10(6) cm(-2) s(-1), in agreement with previous measurements and standard solar models. A global analysis of solar and reactor neutrino results yields Deltam2=7.59_-0.21;+0.19x10(-5) eV2 and theta=34.4_-1.2;+1.3 degrees. The uncertainty on the mixing angle has been reduced from SNO's previous results.
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Measurement of muon neutrino quasielastic scattering on carbon. PHYSICAL REVIEW LETTERS 2008; 100:032301. [PMID: 18232974 DOI: 10.1103/physrevlett.100.032301] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2007] [Indexed: 05/25/2023]
Abstract
The observation of neutrino oscillations is clear evidence for physics beyond the standard model. To make precise measurements of this phenomenon, neutrino oscillation experiments, including MiniBooNE, require an accurate description of neutrino charged current quasielastic (CCQE) cross sections to predict signal samples. Using a high-statistics sample of nu_(mu) CCQE events, MiniBooNE finds that a simple Fermi gas model, with appropriate adjustments, accurately characterizes the CCQE events observed in a carbon-based detector. The extracted parameters include an effective axial mass, M_(A)(eff)=1.23+/-0.20 GeV, that describes the four-momentum dependence of the axial-vector form factor of the nucleon, and a Pauli-suppression parameter, kappa=1.019+/-0.011. Such a modified Fermi gas model may also be used by future accelerator-based experiments measuring neutrino oscillations on nuclear targets.
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Search for electron neutrino appearance at the Delta m2 approximately 1 eV2 scale. PHYSICAL REVIEW LETTERS 2007; 98:231801. [PMID: 17677898 DOI: 10.1103/physrevlett.98.231801] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2007] [Indexed: 05/16/2023]
Abstract
The MiniBooNE Collaboration reports first results of a search for nu e appearance in a nu mu beam. With two largely independent analyses, we observe no significant excess of events above the background for reconstructed neutrino energies above 475 MeV. The data are consistent with no oscillations within a two-neutrino appearance-only oscillation model.
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SU-FF-T-139: Designing a Patient Identification System Using Bioinformatics - A Fingerprint Approach. Med Phys 2007. [DOI: 10.1118/1.2760797] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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SU-FF-J-39: Comparison of Patient Positioning Corrections For Prostate IMRT Patients Using Competing Image Guided Radiation Therapy Technologies. Med Phys 2006. [DOI: 10.1118/1.2240817] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Ifenprodil treatment is associated with a down-regulation of brain aquaporin 4 following cardiac arrest in rats. ACTA NEUROCHIRURGICA. SUPPLEMENT 2006; 95:415-9. [PMID: 16463893 DOI: 10.1007/3-211-32318-x_85] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
OBJECTIVES Ifenprodil, a NMDA receptor polyamine site antagonist, reduces experimental cardiac arrest (CA)-elicited brain edema, which is associated with an up-regulation of aquaporin 4 (AQP4), a brain water-selective channel. However, the interacting roles of NMDA receptors and AQP4 in CA-elicited brain edema are unknown. The objective of this study was to test our hypothesis that ifenprodil treatment is associated with a down-regulation of brain AQP4. METHODS Twenty-five rats were assigned to normal controls (group 1, n = 6) or subjected to eight minutes of asphyxial CA treated with placebo (group 2, n = 9) or ifenprodil (group 3, n = 10). Ifenprodil at 10 mg/kg or normal saline of equal volume was given intraperitoneally, 5 minutes before CA. The density of AQP4 protein and actin bands was scanned and expressed as the ratios of the optical density of AQP4 relative to that of actin. The ANOVA analysis was used to compare the group differences. RESULTS The ratios of the optical density of AQP4 to that of actin were 0.88 +/- 0.06 in group 1, 1.11 +/- 0.08 in group 2 (p < 0.05 vs. group 1), and 0.78 +/- 0.04 in group 3 (p < 0.01 vs. group 2; NS vs. group 1). CONCLUSION Ifenprodil given before CA is associated with a downregulation of brain AQP4 in rats.
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WE-D-I-6B-07: Human and System Error Analysis of a 3D Optical Laser Scanning System for Image-Guided Patient Positioning. Med Phys 2005. [DOI: 10.1118/1.1998543] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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SU-FF-T-314: Initial Monte Carlo Analysis of the Dosimetric Effects of Gold Nanoparticle Radiosensitizers. Med Phys 2005. [DOI: 10.1118/1.1998043] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Abstract
PURPOSE To report an uncommon complication of distal hamstring icing, cryotherapy-induced common peroneal nerve palsy. CASE SUMMARY A 22-year-old football player applied ice to his distal hamstring for 20 min because of soreness. This application of ice resulted in foot drop and sensory changes in the anterior lower leg and dorsum of the foot. Over the next year, full clinical neurologic function returned. DISCUSSION Previously reported cases of cryotherapy-induced common peroneal nerve palsy involved lateral knee or circumferential thigh icing with nerve injury at the fibular neck. This case involved distal hamstring icing, and nerve injury occurred more proximally. RELEVANCE This case demonstrates that caution should be used even when using a modality as common as ice. Ice exposure should be limited in patients with low body fat or in areas where a nerve is not well protected by subcutaneous tissue.
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Abstract
A monoclonal antibody, RS 5, was raised by injecting sieve elements isolated from tissue cultures of Streptanthus tortuosus (Brassicacae) into BALB/c mice and screening resultant hybridoma supernatants for the labeling of phloem using immunofluorescence microscopy. The RS 5 monoclonal antibody identifies a 57-kD protein on immunoblots, which is present in phloem-forming tissue cultures of S. tortuosus but is absent in cultures that lack phloem. Purified 57-kD protein of S. tortuosus is demonstrated to be a phloem-specific beta-amylase. Partial peptide sequences of the 57-kD protein of S. tortuosus are shown to be 96% identical with the corresponding portions of a deduced sequence reported for a major form of beta-amylase in Arabidopsis thaliana. The RS 5 antibody cross-reacts with the major form of A. thaliana beta-amylase on immunoblots, and the antibody also binds to the sieve elements of A. thaliana using immunofluorescence microscopy. The results suggest that the major form of A. thaliana beta-amylase is a phloem-specific enzyme.
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Inhibition of herpes simplex virus type 1 helicase-primase by (dichloroanilino)purines and -pyrimidines. J Med Chem 1995; 38:1820-5. [PMID: 7752206 DOI: 10.1021/jm00010a027] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Herpes simplex virus type 1 (HSV1) encodes a heterotrimeric helicase-primase comprised of the products of three of the seven DNA replication-specific genes. Several dihalo-substituted derivatives of N2-phenylguanines and 2-anilinoadenines weakly inhibited the intrinsic DNA-dependent NTPase activity of the HSV1 helicase-primase, and these compounds inhibited the DNA-unwinding activity of the enzyme. The primase activity of the enzyme was strongly inhibited by 3,4- and 3,5-dichloroanilino derivatives of adenine and 2-aminopyrimidines. These compounds and nucleoside analogs of 2-(3,5-dichloroanilino)purines inhibited viral DNA synthesis in HSV1-infected HeLa cells in culture but also inhibited cellular DNA synthesis, likely as a result of inhibition of cellular primase and/or DNA polymerases.
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Abstract
This is the second of 2 articles on a 3-year investigation of medial collateral ligament sprains of the knee to assess the effectiveness of prophylactic knee braces in NCAA Division I college football players. Position, string, type of session, and daily brace wear were recorded. The injury rates for braced and unbraced knees were used to create an incidence density ratio. The data were stratified and simultaneously controlled for position, string, and session and evaluated for their statistical significance. The 987 Big Ten players generated 155,772 knee exposures over the study period (50% braced). Noticeable differences existed in the rates of injury for the braced and unbraced knees in almost every position during practices, depending on player or nonplayer status. When the influential factors of position, string, and session are considered, there is a consistent but not statistically significant tendency for the players wearing preventive knee braces to experience a lower injury rate than for their unbraced counterparts. For starters and substitutes in the line positions, as well as the linebackers and tight ends, there was a consistent trend toward a lower injury rate in both practices and games. The braced players in the skill positions (backs/kickers), at least during games, exhibited a higher injury rate.
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Abstract
In this prospective, multiinstitutional analysis of medial collateral ligament sprains in college football players, we categorized 987 previously uninjured study subjects according to frequency of wearing preventive knee braces, studied the patterns by which 47 of 100 injuries occurred to unbraced knees, and identified several extrinsic, sport-specific risk factors shared for both braced and unbraced knees. The attendance, brace wear choice, position, string, and session of each participant were recorded daily; medial collateral ligament sprains were reported whenever tissue damage was confirmed. Both the likelihood of wearing braces and risk of injury without them was highly dependent on session (games/practices), position group (line, linebacker/tight end, skill), and string group (players/nonplayers). Subjects wearing braces often faced a high injury risk to their unbraced knees, a finding compatible with the opinion that braces were a necessary evil, best worn when concern over danger of injury outweighed desire for speed and agility. It is concluded that to avoid misinterpretations due to the confounding influence of brace wear selection bias, accurate investigation of daily brace wear patterns is required. Then, before considing the impact of preventive knee braces, a repartitioning of the data base is essential to assure that only similar groups will be compared.
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Abstract
A totally nurse-dependent charging system developed specifically for the labor and delivery suite at the University of Maryland Medical System is described in the article. This easy and effective method of charging was incorporated into an already existing patient census and classification system. The number of relative value units has increased by more than 30%, and the amount of revenue billed has increased by more than $800,000 in the first 10 months after implementation.
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A history of the Ray Brook State Tuberculosis Hospital. NEW YORK STATE JOURNAL OF MEDICINE 1990; 90:406-13. [PMID: 2205813] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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Abstract
ECG patterns observed during cardiac arrest were analyzed in 261 comatose cardiac arrest survivors. Forty-seven patients (18%) exhibited electromechanical dissociation (EMD) at some point before restoration of stable spontaneous circulation. These patients had a higher mortality (P = .05) and a lower rate of cerebral recovery (P = .01) during the one-year follow-up than study patients who did not exhibit EMD. Patients who developed EMD subsequent to defibrillation had better outcome than patients presenting with EMD. Multivariate analysis revealed that age more than 70 years old (P = .007), pulmonary disease (P less than .001), diabetes (P = .013, in-hospital arrests only), and prearrest hypoxemia (P = .013, outside-hospital arrests only) were independently predictive of the occurrence of EMD. Although the generalizability of these findings is limited, they may offer new clues to the pathophysiology of EMD.
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Federal resources for injury control. BULLETIN OF THE NEW YORK ACADEMY OF MEDICINE 1988; 64:857-63. [PMID: 2853641 PMCID: PMC1630602] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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Neurologic recovery after cardiac arrest: effect of duration of ischemia. Brain Resuscitation Clinical Trial I Study Group. Crit Care Med 1985; 13:930-1. [PMID: 4053643] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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T-cell ratios: sperm and asialo GM1 antibody levels in New York City prostitutes. Ann N Y Acad Sci 1984; 437:568-75. [PMID: 6242009 DOI: 10.1111/j.1749-6632.1984.tb37187.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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Continued contact and monitoring as follow-up strategies: a long-term study of obesity treatment. Addict Behav 1978; 3:139-47. [PMID: 717093 DOI: 10.1016/0306-4603(78)90038-2] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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50
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Metastatic glomus jugulare tumor. EAR, NOSE, & THROAT JOURNAL 1977; 56:50-4. [PMID: 189985] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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