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We measured the nuclear-recoil ionization yield in silicon with a cryogenic phonon-sensitive gram-scale detector. Neutrons from a monoenergetic beam scatter off of the silicon nuclei at angles corresponding to energy depositions from 4 keV down to 100 eV, the lowest energy probed so far. The results show no sign of an ionization production threshold above 100 eV. These results call for further investigation of the ionization yield theory and a comprehensive determination of the detector response function at energies below the keV scale.
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The Cryogenic Dark Matter Search low ionization threshold experiment (CDMSlite) achieved efficient detection of very small recoil energies in its germanium target, resulting in sensitivity to lightly ionizing particles (LIPs) in a previously unexplored region of charge, mass, and velocity parameter space. We report first direct-detection limits calculated using the optimum interval method on the vertical intensity of cosmogenically produced LIPs with an electric charge smaller than e/(3×10^{5}), as well as the strongest limits for charge ≤e/160, with a minimum vertical intensity of 1.36×10^{-7} cm^{-2} s^{-1} sr^{-1} at charge e/160. These results apply over a wide range of LIP masses (5 MeV/c^{2} to 100 TeV/c^{2}) and cover a wide range of ßγ values (0.1-10^{6}), thus excluding nonrelativistic LIPs with ßγ as small as 0.1 for the first time.
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We present limits on spin-independent dark matter-nucleon interactions using a 10.6 g Si athermal phonon detector with a baseline energy resolution of σ_{E}=3.86±0.04(stat)_{-0.00}^{+0.19}(syst) eV. This exclusion analysis sets the most stringent dark matter-nucleon scattering cross-section limits achieved by a cryogenic detector for dark matter particle masses from 93 to 140 MeV/c^{2}, with a raw exposure of 9.9 g d acquired at an above-ground facility. This work illustrates the scientific potential of detectors with athermal phonon sensors with eV-scale energy resolution for future dark matter searches.
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This corrects the article DOI: 10.1103/PhysRevLett.121.051301.
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We present the first limits on inelastic electron-scattering dark matter and dark photon absorption using a prototype SuperCDMS detector having a charge resolution of 0.1 electron-hole pairs (CDMS HVeV, a 0.93 g CDMS high-voltage device). These electron-recoil limits significantly improve experimental constraints on dark matter particles with masses as low as 1 MeV/c^{2}. We demonstrate a sensitivity to dark photons competitive with other leading approaches but using substantially less exposure (0.49 g d). These results demonstrate the scientific potential of phonon-mediated semiconductor detectors that are sensitive to single electronic excitations.
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We report the result of a blinded search for weakly interacting massive particles (WIMPs) using the majority of the SuperCDMS Soudan data set. With an exposure of 1690 kg d, a single candidate event is observed, consistent with expected backgrounds. This analysis (combined with previous Ge results) sets an upper limit on the spin-independent WIMP-nucleon cross section of 1.4×10^{-44} (1.0×10^{-44}) cm^{2} at 46 GeV/c^{2}. These results set the strongest limits for WIMP-germanium-nucleus interactions for masses >12 GeV/c^{2}.
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The CDMS low ionization threshold experiment (CDMSlite) uses cryogenic germanium detectors operated at a relatively high bias voltage to amplify the phonon signal in the search for weakly interacting massive particles (WIMPs). Results are presented from the second CDMSlite run with an exposure of 70 kg day, which reached an energy threshold for electron recoils as low as 56 eV. A fiducialization cut reduces backgrounds below those previously reported by CDMSlite. New parameter space for the WIMP-nucleon spin-independent cross section is excluded for WIMP masses between 1.6 and 5.5 GeV/c^{2}.
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The association between substance use and communicable diseases, and the need for substance user treatment services for patients treated for communicable diseases, is well documented. This study builds upon this knowledge in that it quantifies the need and demand for substance user treatment services in a large population of patients treated for communicable diseases, specifically, sexually transmitted diseases (STDs), an area in which there is insufficient research published in the literature, but which is essential for policy development. More than 1700 patients treated for STDs in publicly funded clinics in Michigan between 1994-1995 were interviewed about their substance use, consequences of use and demand for substance user treatment services. Results indicated that the rates of substance use and demand for substance user treatment services were significantly higher among persons encountered in the STD clinics compared to the Michigan general adult population; however, a large proportion of STD patients determined to need substance user treatment services according to DSM-III-R criteria for "substance dependence" and "abuse" did not report ever receiving it. These results are followed by a discussion of possible policy implications for planning for substance user treatment services for patients treated for STDs in publicly funded clinics and suggestions for further research.
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Infecções Sexualmente Transmissíveis/epidemiologia , Transtornos Relacionados ao Uso de Substâncias/epidemiologia , Adolescente , Adulto , Feminino , Acessibilidade aos Serviços de Saúde , Humanos , Drogas Ilícitas , Masculino , Michigan/epidemiologia , Pessoa de Meia-Idade , Avaliação das Necessidades , Vigilância da População , Infecções Sexualmente Transmissíveis/psicologia , Centros de Tratamento de Abuso de Substâncias , Transtornos Relacionados ao Uso de Substâncias/psicologiaRESUMO
The test-retest reliability of lifetime substance abuse and dependence diagnoses obtained by telephone interviewers was investigated. Trained personnel administered two identical interviews based on a modified Diagnostic Interview Schedule-Substance Abuse Module (DISSAM) approximately a week apart for 100 respondents, of whom 55 were receiving alcohol or other drug treatment and 45 and randomly selected from residential households in one Michigan county. The uncorrected agreement for all lifetime dependence diagnoses exceeded 93% for all six categories assessed and the more conservative chance corrected agreement (Cohen's Kappa coefficient kappa) was .92 (alcohol),.76 (marijuana),.87 (cocaine), and .71 (other opiates). Kappa coefficients for hallucinogens and heroin dependence could not be calculated due to low (i.e., 5% or less) base rates. Likewise, kappa was calculated only for a single abuse diagnosis, alcohol, with kappa = .42 and 95% agreement. In the interpretation of kappa, the standard applied was: kappa ranging from .41 to .60 represented moderate agreement, kappa ranging from .61 to .80 represented substantial agreement, and kappa ranging from .81 to 1.00 represented excellent agreement. Thus, test-retest reliability was excellent for lifetime alcohol and cocaine dependence and was substantial for lifetime marijuana and other opiates dependence. These results indicate that lifetime psychoactive substance abuse diagnoses can be obtained fairly reliably over the telephone using trained lay interviewers.
Assuntos
Entrevistas como Assunto , Psicotrópicos , Reprodutibilidade dos Testes , Transtornos Relacionados ao Uso de Substâncias/diagnóstico , Transtornos Relacionados ao Uso de Substâncias/psicologia , Adolescente , Adulto , Idoso , Alcoolismo/diagnóstico , Cocaína , Coleta de Dados , Estudos de Avaliação como Assunto , Feminino , Heroína , Humanos , Masculino , Abuso de Maconha/diagnóstico , Pessoa de Meia-Idade , Entorpecentes , Sensibilidade e EspecificidadeAssuntos
Estimulantes do Sistema Nervoso Central , Drogas Ilícitas , Propiofenonas , Transtornos Relacionados ao Uso de Substâncias/psicologia , Adolescente , Adulto , Feminino , Humanos , Legislação de Medicamentos , Masculino , Michigan/epidemiologia , Pessoa de Meia-Idade , Saúde Pública , Transtornos Relacionados ao Uso de Substâncias/epidemiologia , Transtornos Relacionados ao Uso de Substâncias/reabilitaçãoRESUMO
Computed tomography was performed in 24 patients with bladder carcinoma, 29 patients with prostate carcinoma, and one patient with simultaneous bladder and prostate carcinoma. In nine patients (16%), the stage of the carcinoma would have been underestimated based on CT alone. Six of these nine patients had only microscopic or laboratory evidence (elevated serum acid phosphatase level) of more widespread disease than what was demonstrated by CT. The overall accuracy of pelvic lymph node evaluation by CT was 79% in 34 patients. The 21% inaccuracy arises from five false-negative cass in which there was microscopic involvement within normal-sized nodes (4 patients) or only minimally enlarged (2.0 cm or less) nodes (1 patient), and two false-positive cases related to benign changes in nodes. CT was unable to differentiate Stage A, B1, and B2 bladder tumors. CT was used in planning portals for 16 patients who underwent external beam radiation therapy. CT was also used to measure the volume of the prostate prior to placement of 125I seeds for therapy, and to assess the positioning of the seeds.