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1.
Phys Rev Lett ; 130(10): 101001, 2023 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-36962014

RESUMO

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}.

2.
Phys Rev Lett ; 130(10): 101002, 2023 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-36962032

RESUMO

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.

3.
Eur Phys J C Part Fields ; 82(7): 618, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35859696

RESUMO

DUNE is a dual-site experiment for long-baseline neutrino oscillation studies, neutrino astrophysics and nucleon decay searches. ProtoDUNE Dual Phase (DP) is a 6  ×  6  ×  6 m 3 liquid argon time-projection-chamber (LArTPC) that recorded cosmic-muon data at the CERN Neutrino Platform in 2019-2020 as a prototype of the DUNE Far Detector. Charged particles propagating through the LArTPC produce ionization and scintillation light. The scintillation light signal in these detectors can provide the trigger for non-beam events. In addition, it adds precise timing capabilities and improves the calorimetry measurements. In ProtoDUNE-DP, scintillation and electroluminescence light produced by cosmic muons in the LArTPC is collected by photomultiplier tubes placed up to 7 m away from the ionizing track. In this paper, the ProtoDUNE-DP photon detection system performance is evaluated with a particular focus on the different wavelength shifters, such as PEN and TPB, and the use of Xe-doped LAr, considering its future use in giant LArTPCs. The scintillation light production and propagation processes are analyzed and a comparison of simulation to data is performed, improving understanding of the liquid argon properties.

4.
Eur Phys J C Part Fields ; 81(4): 322, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34720713

RESUMO

The Deep Underground Neutrino Experiment (DUNE) will be a powerful tool for a variety of physics topics. The high-intensity proton beams provide a large neutrino flux, sampled by a near detector system consisting of a combination of capable precision detectors, and by the massive far detector system located deep underground. This configuration sets up DUNE as a machine for discovery, as it enables opportunities not only to perform precision neutrino measurements that may uncover deviations from the present three-flavor mixing paradigm, but also to discover new particles and unveil new interactions and symmetries beyond those predicted in the Standard Model (SM). Of the many potential beyond the Standard Model (BSM) topics DUNE will probe, this paper presents a selection of studies quantifying DUNE's sensitivities to sterile neutrino mixing, heavy neutral leptons, non-standard interactions, CPT symmetry violation, Lorentz invariance violation, neutrino trident production, dark matter from both beam induced and cosmogenic sources, baryon number violation, and other new physics topics that complement those at high-energy colliders and significantly extend the present reach.

5.
Rhinology ; 59(1): 98-104, 2021 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-32830808

RESUMO

BACKGROUND: Pregnancy as an immunosuppressive condition and with the associated tendency for mucosal oedema can predis- pose women to acute rhinosinusitis. Our hypothesis was that pregnancy enhances opportunistic sinus infections. METHODOLOGY: We retrospectively collected data on pregnant women with acute rhinosinusitis treated at the Department of Otorhinolaryngology, Helsinki University Hospital, Finland in 2010-2015. Maxillary puncture was performed on all patients, and patients with purulent sinus secretions and bacterial culture were included in the study. Clinical data on patients and microbial findings of bacterial cultures were recorded and compared with those of non-pregnant controls. RESULTS: Ninety-five pregnant patients and 91 controls were included. The bacterial cultures of pregnant patients revealed bac- terial growth more often than control patients’ specimens (78.9% vs. 54.9%). The most common bacterial findings (pregnant vs. control patients) were Streptococcus pneumoniae 43.2% vs. 20.9%, Haemophilus influenzae 22.1% vs. 16.5%, and Moraxella catar- rhalis 10.5% vs. 2.2%. S. pneumoniae was the most frequent finding in all trimesters, and the proportion of S. pneumoniae sinusitis was highest during the last trimester of pregnancy. CONCLUSIONS: The pathogens of acute rhinosinusitis in pregnant patients are the same as in non-pregnant patients, however, the proportions differ; during pregnancy S. pneumoniae infection is more frequent.


Assuntos
Rinite , Sinusite , Doença Aguda , Antibacterianos/uso terapêutico , Feminino , Haemophilus influenzae , Humanos , Gravidez , Estudos Retrospectivos , Rinite/tratamento farmacológico , Sinusite/tratamento farmacológico , Streptococcus pneumoniae
6.
Phys Rev Lett ; 121(11): 111303, 2018 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-30265123

RESUMO

We present new constraints on sub-GeV dark-matter particles scattering off electrons based on 6780.0 kg d of data collected with the DarkSide-50 dual-phase argon time projection chamber. This analysis uses electroluminescence signals due to ionized electrons extracted from the liquid argon target. The detector has a very high trigger probability for these signals, allowing for an analysis threshold of three extracted electrons, or approximately 0.05 keVee. We calculate the expected recoil spectra for dark matter-electron scattering in argon and, under the assumption of momentum-independent scattering, improve upon existing limits from XENON10 for dark-matter particles with masses between 30 and 100 MeV/c^{2}.

7.
Phys Rev Lett ; 121(8): 081307, 2018 Aug 24.
Artigo em Inglês | MEDLINE | ID: mdl-30192596

RESUMO

We present the results of a search for dark matter weakly interacting massive particles (WIMPs) in the mass range below 20 GeV/c^{2} using a target of low-radioactivity argon with a 6786.0 kg d exposure. The data were obtained using the DarkSide-50 apparatus at Laboratori Nazionali del Gran Sasso. The analysis is based on the ionization signal, for which the DarkSide-50 time projection chamber is fully efficient at 0.1 keVee. The observed rate in the detector at 0.5 keVee is about 1.5 event/keVee/kg/d and is almost entirely accounted for by known background sources. We obtain a 90% C.L. exclusion limit above 1.8 GeV/c^{2} for the spin-independent cross section of dark matter WIMPs on nucleons, extending the exclusion region for dark matter below previous limits in the range 1.8-6 GeV/c^{2}.

8.
Phys Rev Lett ; 120(13): 132502, 2018 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-29694188

RESUMO

The Majorana Collaboration is operating an array of high purity Ge detectors to search for neutrinoless double-ß decay in ^{76}Ge. The Majorana Demonstrator comprises 44.1 kg of Ge detectors (29.7 kg enriched in ^{76}Ge) split between two modules contained in a low background shield at the Sanford Underground Research Facility in Lead, South Dakota. Here we present results from data taken during construction, commissioning, and the start of full operations. We achieve unprecedented energy resolution of 2.5 keV FWHM at Q_{ßß} and a very low background with no observed candidate events in 9.95 kg yr of enriched Ge exposure, resulting in a lower limit on the half-life of 1.9×10^{25} yr (90% C.L.). This result constrains the effective Majorana neutrino mass to below 240-520 meV, depending on the matrix elements used. In our experimental configuration with the lowest background, the background is 4.0_{-2.5}^{+3.1} counts/(FWHM t yr).

9.
J Environ Radioact ; 178-179: 28-35, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28755564

RESUMO

Pacific Northwest National Laboratory reports on the detection of 39Ar at the location of an underground nuclear explosion on the Nevada Nuclear Security Site. The presence of 39Ar was not anticipated at the outset of the experimental campaign but results from this work demonstrated that it is present, along with 37Ar and 85Kr in the subsurface at the site of an underground nuclear explosion. Our analysis showed that by using state-of-the-art technology optimized for radioargon measurements, it was difficult to distinguish 39Ar from the fission product 85Kr. Proportional counters are currently used for high-sensitivity measurement of 37Ar and 39Ar. Physical and chemical separation processes are used to separate argon from air or soil gas, yielding pure argon with contaminant gases reduced to the parts-per-million level or below. However, even with purification at these levels, the beta decay signature of 85Kr can be mistaken for that of 39Ar, and the presence of either isotope increases the measurement background level for the measurement of 37Ar. Measured values for the 39Ar measured at the site ranged from 36,000 milli- Becquerel/standard-cubic-meter-of-air (mBq/SCM) for shallow bore holes to 997,000 mBq/SCM from the rubble chimney from the underground nuclear explosion.


Assuntos
Argônio/análise , Armas Nucleares , Monitoramento de Radiação , Poluentes Radioativos/análise , Nevada
10.
J Vet Pharmacol Ther ; 38(6): 590-5, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25955782

RESUMO

The objective of this study was to describe the population pharmacokinetics (PK) of mosapride under fasting and fed conditions. A single 5-mg oral dose of mosapride was administered to fasted (n = 15) and fed (n = 12) beagle dogs. Plasma concentrations of mosapride were subsequently measured by liquid chromatography-tandem mass spectrometry. Data were analyzed using modeling approaches with the NONMEM 7.2 software. A one-compartment open PK model utilizing model event time (MTIME) with first-order absorption and first-order elimination was found to be more appropriate than all other PK models tested. The absorption rate constants of mosapride were significantly decreased under fed conditions, compared to fasting conditions. The observed bootstrap medians of PK parameters were generally consistent with the corresponding population mean estimates. Furthermore, with the exception of some mosapride concentrations, most of observed data fell into the range of the 5th and 95th percentiles of the simulated values. Overall, the final model was able to describe the observed mosapride concentrations reasonably well. These findings suggest that food intake affects both the rate and extent of absorption of mosapride and that the pharmacological effect of mosapride can differ significantly depending on food intake.


Assuntos
Benzamidas/farmacocinética , Ingestão de Alimentos , Morfolinas/farmacocinética , Agonistas do Receptor de Serotonina/farmacocinética , Administração Oral , Animais , Benzamidas/administração & dosagem , Benzamidas/sangue , Cromatografia Líquida , Cães , Jejum , Masculino , Modelos Biológicos , Morfolinas/administração & dosagem , Morfolinas/sangue , Agonistas do Receptor de Serotonina/administração & dosagem , Agonistas do Receptor de Serotonina/sangue , Espectrometria de Massas em Tandem
11.
Vet Parasitol ; 197(3-4): 580-5, 2013 Nov 08.
Artigo em Inglês | MEDLINE | ID: mdl-23993633

RESUMO

A case-control study was performed to investigate the association between colic of all types in Swedish horses and infection with the equine tapeworm Anoplocephala perfoliata. Colic cases were defined by clinical signs consistent with the presence of abdominal pain, and the control horses had no signs of colic within the last year but attended a clinic for other reasons. Blood and fecal samples were collected by veterinarian from 67 horses with signs of colic and 67 control horses. The sera were analyzed using serodiagnostic assay anti-12/13 kDa IgG(T) ELISA. The fecal samples, 30 g from each horse, were analyzed with a modified sugar salt flotation method with a density of 1.280. A significant association was found between the presence of A. perfoliata eggs in feces and colic with a 16 times higher risk of colic if eggs had been observed in fecal samples. However, there was no significant association between colic and the median OD-values in the serological diagnosis, nor when recommended cut-offs were used. The study concludes that A. perfoliata is a risk factor for colic in Swedish horses and it suggests that the modified flotation method can be used as a diagnostic tool for identifying horses at risk.


Assuntos
Cestoides/classificação , Infecções por Cestoides/veterinária , Cólica/veterinária , Doenças dos Cavalos/etiologia , Animais , Estudos de Casos e Controles , Infecções por Cestoides/complicações , Infecções por Cestoides/epidemiologia , Infecções por Cestoides/parasitologia , Cólica/etiologia , Fezes/parasitologia , Doenças dos Cavalos/epidemiologia , Doenças dos Cavalos/parasitologia , Cavalos , Suécia/epidemiologia
12.
Rev Sci Instrum ; 84(1): 013304, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23387639

RESUMO

In this paper, we describe the performance of the Los Alamos spallation-driven solid-deuterium ultra-cold neutron (UCN) source. Measurements of the cold neutron flux, the very low energy neutron production rate, and the UCN rates and density at the exit from the biological shield are presented and compared to Monte Carlo predictions. The cold neutron rates compare well with predictions from the Monte Carlo code MCNPX and the UCN rates agree with our custom UCN Monte Carlo code. The source is shown to perform as modeled. The maximum delivered UCN density at the exit from the biological shield is 52(9) UCN/cc with a solid deuterium volume of ~1500 cm(3).

13.
Indian J Pharm Sci ; 74(3): 211-6, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-23440938

RESUMO

Rubus coreanus fruits have been employed as a traditional medicine for centuries in the Asia-Pacific region. Its pharmacological action differs according to the different extraction methods utilized and the degree of fruit ripening. In this study, we determined the cellular effect of different ethanol extracts of mature and immature Rubus coreanus fruits in human hepatic cell line, HepG2 cells. The antioxidant activity, effect on superoxide dismutase activity and cholesterol biosynthesis efficiency was also evaluated. Immature Rubus coreanus extract showed higher antioxidant capability, compared with that of its mature fractions. Cellular antioxidant proteins including HO-1, Cu/Zn-superoxide dismutase and catalase were highly expressed in the presence of Rubus coreanus. Cholesterol levels in HepG2 cells treated with the water fraction of immature Rubus coreanus were significantly reduced. This antihyperlipidaemic action of Rubus coreanus is a consequence of cholesterol biosynthesis and extracellular secretion in HepG2 cells. These results indicate that among different ethanol fraction of mature and immature Rubus coreanus fruit extracts, water extract of immature fruit extract shows higher antioxidant as well as higher antihyperlipidaemic action.

14.
Phys Rev Lett ; 105(18): 181803, 2010 Oct 29.
Artigo em Inglês | MEDLINE | ID: mdl-21231098

RESUMO

A precise measurement of the neutron decay ß asymmetry A0 has been carried out using polarized ultracold neutrons from the pulsed spallation ultracold neutron source at the Los Alamos Neutron Science Center. Combining data obtained in 2008 and 2009, we report A0 = -0.119 66±0.000 89{-0.001 40}{+0.001 23}, from which we determine the ratio of the axial-vector to vector weak coupling of the nucleon g{A}/g{V}=-1.275 90{-0.004 45}{+0.004 09}.

15.
Phys Rev Lett ; 102(1): 012301, 2009 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-19257182

RESUMO

We report the first measurement of an angular correlation parameter in neutron beta decay using polarized ultracold neutrons (UCN). We utilize UCN with energies below about 200 neV, which we guide and store for approximately 30 s in a Cu decay volume. The interaction of the neutron magnetic dipole moment with a static 7 T field external to the decay volume provides a 420 neV potential energy barrier to the spin state parallel to the field, polarizing the UCN before they pass through an adiabatic fast passage spin flipper and enter a decay volume, situated within a 1 T field in a 2x2pi solenoidal spectrometer. We determine a value for the beta-asymmetry parameter A_{0}=-0.1138+/-0.0046+/-0.0021.

16.
Phys Rev Lett ; 101(9): 091302, 2008 Aug 29.
Artigo em Inglês | MEDLINE | ID: mdl-18851600

RESUMO

We report the direct measurement of the 7Be solar neutrino signal rate performed with the Borexino detector at the Laboratori Nazionali del Gran Sasso. The interaction rate of the 0.862 MeV 7Be neutrinos is 49+/-3stat+/-4syst counts/(day.100 ton). The hypothesis of no oscillation for 7Be solar neutrinos is inconsistent with our measurement at the 4sigma C.L. Our result is the first direct measurement of the survival probability for solar nu(e) in the transition region between matter-enhanced and vacuum-driven oscillations. The measurement improves the experimental determination of the flux of 7Be, pp, and CNO solar nu(e), and the limit on the effective neutrino magnetic moment using solar neutrinos.

17.
Artigo em Inglês | MEDLINE | ID: mdl-8899778

RESUMO

The first case of oral hairy leukoplakia in an HIV-negative patient with multiple myeloma is reported. The patient is a 56-year old man who has had monoclonal gammopathy of undetermined significance since 1986 and has been treated for a symptomatic multiple myeloma since 1993. The clinical and histopathologic findings are typical for oral hairy leukoplakia, and Epstein-Barr virus was demonstrated with polymerase chain reaction technique. Although a relatively large number of cases of oral hairy leukoplakia has been reported in HIV-negative patients, both immunocompromised and immunocompetent, only a few of these patients have had a malignant hematologic disease.


Assuntos
Leucoplasia Pilosa/complicações , Mieloma Múltiplo/complicações , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Antivirais/uso terapêutico , DNA Viral/análise , Dexametasona , Doxorrubicina/administração & dosagem , Soronegatividade para HIV , Herpesvirus Humano 4/isolamento & purificação , Humanos , Hospedeiro Imunocomprometido , Interferon alfa-2 , Interferon-alfa/uso terapêutico , Leucoplasia Pilosa/tratamento farmacológico , Leucoplasia Pilosa/virologia , Masculino , Pessoa de Meia-Idade , Mieloma Múltiplo/tratamento farmacológico , Mieloma Múltiplo/imunologia , Proteínas Recombinantes , Vincristina/administração & dosagem
19.
Br J Haematol ; 84(4): 746-8, 1993 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-8217837

RESUMO

Serum deoxythymidine kinase activity (S-TK) was determined in the diagnostic evaluation and follow-up of patients with monoclonal gammopathy of undetermined significance (MGUS). During a 4-year period 35 patients were included in the study. Normal concentrations of S-TK were found in 33. Patients with non-progressive monoclonal gammopathy kept a stable, and for the individual, a characteristic level of S-TK during several years of follow-up. A moderately elevated level of S-TK during observation did not indicate progression. Even in four out of five patients developing symptomatic multiple myeloma S-TK remained unchanged. Determination of S-TK does not give diagnostic or prognostic information in monoclonal gammopathy.


Assuntos
Biomarcadores Tumorais/sangue , Paraproteinemias/enzimologia , Lesões Pré-Cancerosas/enzimologia , Timidina Quinase/sangue , Idoso , Idoso de 80 Anos ou mais , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Mieloma Múltiplo/diagnóstico , Mieloma Múltiplo/enzimologia , Prognóstico
20.
Oecologia ; 91(3): 396-403, 1992 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28313548

RESUMO

Two "Bremerhaven caissons" were used to investigate the interactions of cadmium (Cd) with sea water, particulate matter, sediments, suspended particular matter (SPM), and organisms in enclosed sea water-sediment systems, on the tidal mud flats of Jade Bay (FRG). One caisson was artificially contaminated by continuously injecting cadmium (as a chloride) so as to maintain a Cd concentration of 100 µg/l in the inflowing water of each tidal cycle for 22 days. The other caisson was used as a control system. About 30% of the total Cd introduced into the caisson was transferred from the aqueous phase to the other phases during each tidal cycle. Cadmium appears to accumulate in elements of the system in the order SPM, organisms, sediments, water. SPM, initially low in Cd entering the system, rapidly accumulated Cd from solution after the first tidal cycle and the concentration continued to increase during the experiment. Particulate Cd transferred to the sediments results in the development of a Cd-rich layer that attained a depth of 4 cm over the course of the experiment. Among the biota, the blue mussel (Mytilus edulis) progressively accumulated the highest concentrations of Cd whereas other taxa, like polychaetes, accumulated less of the metal. Differnces in Cd accumulation appear to be due to the habitats of the different species and their ability to assimilate Cd from the dissolved and particulate phases. Together, the data indicate that in the contamination of tidal mud flats with aqueous cadmium most of the metal would remain available to the organisms in the aqueous phases and weakly bound to particulate matter. This would present the greatest environmental danger to filter feeders but not to animals living in the sediments.

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