27 research outputs found

    A next-generation liquid xenon observatory for dark matter and neutrino physics

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    The nature of dark matter and properties of neutrinos are among the most pressing issues in contemporary particle physics. The dual-phase xenon time-projection chamber is the leading technology to cover the available parameter space for weakly interacting massive particles, while featuring extensive sensitivity to many alternative dark matter candidates. These detectors can also study neutrinos through neutrinoless double-beta decay and through a variety of astrophysical sources. A next-generation xenon-based detector will therefore be a true multi-purpose observatory to significantly advance particle physics, nuclear physics, astrophysics, solar physics, and cosmology. This review article presents the science cases for such a detector

    Decompressive craniotomy: prognostic factors and complications in 89 patients Craniotomia descompressiva: análise de fatores prognósticos e complicações em 89 pacientes

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    Decompressive craniotomy (DC) is applied to treat post-traumatic intracranial hypertension (ICH). The purpose of this study is to identify prognostic factors and complications of unilateral DC. Eighty-nine patients submited to unilateral DC were retrospectively analyzed over a period of 30 months. Qui square independent test and Fisher test were used to identify prognostic factors. The majority of patients were male (87%). Traffic accidents had occurred in 47% of the cases. 64% of the patients had suffered severe head injury, while pupillary abnormalities were already present in 34%. Brain swelling plus acute subdural hematoma were the most common tomographic findings (64%). Complications occurred in 34.8% of the patients: subdural effusions in 10 (11.2%), hydrocephalus in 7 (7.9%) and infection in 14 (15.7%). The admittance Glasgow coma scale was a statistically significant predictor of outcome ( p=0.0309).<br>A craniotomia descompressiva (CD) é técnica utilizada para tratamento da hipertensão intracraniana (HIC) pós-traumática. O objetivo do estudo foi determinar fatores prognósticos e complicações nos pacientes submetidos a esta técnica. Realizou-se estudo retrospectivo de 89 pacientes submetidos à CD unilateral para tratamento da HIC pós-traumática durante 30 meses. Utilizou-se testes do Qui-quadrado de independência e teste exato de Fisher para análise de fatores independentes de prognóstico. A maioria dos pacientes era do sexo masculino (87%). A causa mais comum foi o acidente de trânsito (47%). A maioria apresentava traumatismo cranioencefálico grave (64%), 34% já apresentavam anisocoria. O achado tomográfico mais comum foi a associação entre tumefação cerebral e hematoma subdural agudo (64%). Em 34,8% dos pacientes houve complicações inerentes à técnica: coleção subdural (11,2%), hidrocefalia (7,9%) e infecção (15,7%). A escala de coma de Glasgow à admissão correlacionou-se estatisticamente como fator prognóstico (p=0,0309)

    Propionic acid derivatives confined in mesoporous silica: monomers or dimers? The case of ibuprofen investigated by static and dynamic ab initio simulations

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    Confinement in mesoporous silica can greatly increase the solubility of pharmaceutical compounds. Propionic acid derivatives (a very popular class of drugs that include ibuprofen and ketoprofen) would greatly benefit from such technology, given their common apolar character. However, it is still debated whether, after confinement, these drugs are adsorbed on the pore walls as individual molecules or they keep the H-bonded dimeric structure that exists in their crystalline form. Their physical state inside the mesopores could have important consequences on the final performances of the drug delivery system. We employed accurate periodic density functional theory simulations, both static and dynamic, to investigate the issue. We simulated ibuprofen, as a model for all propionic acid derivatives, adsorbed both as a monomer and as a dimer inside a realistic model for the MCM-41 mesoporous silica. We found that adsorption is energetically favored in both cases, driven by both vdW and H-bond interactions. However, through ab initio molecular dynamics, we observed a continuous forming, breaking and reforming of these interactions. In the end, by comparing computed energetics, vibrational spectra and mobility, we were able to provide some important clues on the physical state of this class of drugs inside mesoporous silica, helping to define which drug family (monomer or dimer) is more probable after confinement
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