Executive function in patients with obstructive sleep apnea treated with continuous positive airway pressure

Obstructive sleep apnea (OSA) is characterized by disrupted breathing and hypoxemia during sleep, daytime sleepiness, and changes in cognition and mood. One important question is regarding the reversibility of cognitive deficits after treatment with continuous positive airway pressure (CPAP). Here, we report the outcomes of CPAP treatment as measured by tests of attention and executive function. Thirty-seven individuals with moderate to severe OSA and compliant on CPAP treatment were studied with working memory tasks, neuropsychological testing, and overnight polysomnographic sleep study and compared to 27 healthy controls. CPAP improved the respiratory disturbance index, minimum and mean oxygen saturation (SpO2), subjective sleep quality, and daytime sleepiness ratings compared to pre-treatment values. In terms of current neurocognitive function, treated individuals with OSA performed at a comparable level to controls on basic working memory storage functions but still showed a significant reduction on tests of working memory requiring the central executive. The OSA group also performed worse on neuropsychological measures of complex attention, executive function, and psychomotor speed. While CPAP is an effective treatment for OSA in terms of ameliorating breathing disruption and oxygen desaturation during sleep, as well as daytime sleepiness, some cognitive deficits may be more resistant to treatment. (JINS, 2010, 16, 1077-1088.) Copyright © The International Neuropsychological Society 2010.published_or_final_versio

The Role of Daytime Sleepiness in Psychosocial Outcomes after Treatment for Obstructive Sleep Apnea

published_or_final_versio

The Hubbard model within the equations of motion approach

The Hubbard model has a special role in Condensed Matter Theory as it is considered as the simplest Hamiltonian model one can write in order to describe anomalous physical properties of some class of real materials. Unfortunately, this model is not exactly solved except for some limits and therefore one should resort to analytical methods, like the Equations of Motion Approach, or to numerical techniques in order to attain a description of its relevant features in the whole range of physical parameters (interaction, filling and temperature). In this manuscript, the Composite Operator Method, which exploits the above mentioned analytical technique, is presented and systematically applied in order to get information about the behavior of all relevant properties of the model (local, thermodynamic, single- and two- particle ones) in comparison with many other analytical techniques, the above cited known limits and numerical simulations. Within this approach, the Hubbard model is shown to be also capable to describe some anomalous behaviors of the cuprate superconductors.Comment: 232 pages, more than 300 figures, more than 500 reference

World Society of Emergency Surgery (WSES) guidelines for management of skin and soft tissue infections

Peer reviewe

DOPING DEPENDENCE OF HIGH-ENERGY SPECTRAL WEIGHTS FOR THE HIGH-TC CUPRATES

In this paper we present calculation of the photo- and inverse photoemission spectra, and the O 1s and Cu 2p core-level spectra for the high-T(c) materials, using a multiband Hubbard Hamiltonian. The spectra are obtained for small clusters containing two Cu atoms (Cu2O7 and Cu2O8) for the undoped, electron-doped, and hole-doped cases. In order to investigate the sensitivity of the spectra to cluster size and localized versus delocalized oxygen levels, a comparison is made with a (K-dependent) impurity approach and results from a CuO4 cluster. Special attention is paid to the doping dependence of the spectra and low-energy states and to the redistribution of spectral weights upon doping

STRONG NONLOCAL CONTRIBUTIONS TO CU 2P PHOTOELECTRON-SPECTROSCOPY

Calculations of Cu 2p photoelectron spectra for a Cu3O10 cluster with a reduced basis set show that the introduction of more Cu sites leads to a revised interpretation of the Cu 2p spectrum. Besides the usual peaks of mainly 3d9 and 3d10Lunderbar character another peak appears at lower binding energy. This peak is of mainly 3d10 character. The hole has moved away from the core hole potential and has formed a Zhang-Rice singlet on a neighboring CuO4 unit. This effect explains the asymmetric line shape of the main line in the Cu 2p spectra of CuO and the high-T(c) compounds. For formally trivalent copper compounds, such as NaCuO2, this effect disappears and a narrow line shape is observed. The consequences of hole doping (33%) on the Cu 2p spectra have also been studied. The peak assignment turns out to be very similar to that of the undoped system

SPECTRAL-WEIGHT TRANSFER - BREAKDOWN OF LOW-ENERGY-SCALE SUM-RULES IN CORRELATED SYSTEMS

In this paper we study the spectral-weight transfer from the high- to the low-energy scale by means of exact diagonalization of finite clusters for the Mott-Hubbard and charge-transfer model. We find that the spectral-weight transfer is very sensitive to the hybridization strength as well as to the amount of doping. This implies that the effective number of low-energy degrees of freedom is a function of the hybridization and therefore of the volume and temperature. In this sense it is not possible to define a Hamiltonian which describes the low-energy-scale physics unless one accepts an effective nonparticle conservation