2,042 research outputs found
Origin of Gamma Frequency Power during Hippocampal Sharp-Wave Ripples
Hippocampal sharp-wave ripples (SPW-Rs) support consolidation of recently acquired episodic memories and planning future actions by generating ordered neuronal sequences of previous or future experiences. SPW-Rs are characterized by several spectral components: a slow (5–15 Hz) sharp-wave, a high-frequency “ripple” oscillation (150–200 Hz), and a slow “gamma” oscillation (20–40 Hz). Using laminar hippocampal recordings and optogenetic manipulations, we dissected the origin of these spectral components. We show that increased power in the 20–40 Hz band does not reflect an entrainment of CA1 and CA3 neurons at gamma frequency but the power envelope of overlapping ripples. Spike-local field potential coupling between unit firing in CA1 and CA3 regions during SPW-Rs is lowest in the gamma band. Longer SPW-Rs are preceded by increased firing in the entorhinal cortex. Thus, fusion of SPW-Rs leads to lengthening of their duration associated with increased power in the slow gamma band without the presence of true oscillation
Effects of an outpatient education program in patients with uncontrolled asthma
OBJECTIVE: To evaluate the effects of an outpatient education program in patients with uncontrolled asthma. METHODS: This was an uncontrolled study evaluating an educational intervention and involving patients with uncontrolled asthma ≥ 14 years of age. The participants completed a questionnaire designed to assess the level of asthma control, the inhalation technique, and quality of life. All of the patients underwent pulmonary function testing, after which they participated in an education program consisting of one 45-min face-to-face session, followed by phone interviews at two, four, and eight weeks. The participants were reevaluated after three months. RESULTS: Sixty-three patients completed the study. There was a significant improvement in the level of asthma control (p < 0.001). Of the 63 patients, 28 (44.4%) and 6 (9.5%) were classified as having partially controlled asthma and controlled asthma, respectively. The mean FEV1 was 63.0 ± 20.0% and 68.5 ± 21.2% of the predicted value prior to and after the educational intervention, respectively (p = 0.002), and all of the quality of life scores improved (p < 0.05 for all). The same was true for the proportion of patients prior to and after the educational intervention using the proper inhalation technique when using metered dose inhalers (15.4% vs. 46.2%; p = 0.02) and dry powder inhalers (21.3% vs. 76.6%; p < 0.001). The logistic regression analysis revealed that an incorrect inhalation technique identified during the first evaluation was independently associated with a favorable response to the educational intervention. CONCLUSIONS: This study suggests that an outpatient education program for asthma patients improves the level of asthma control, lung function parameters, and quality of life. An incorrect inhalation technique identified during the first evaluation was predictive of a favorable response to the educational intervention
Enhancement of nematic order and global phase diagram of a lattice model for coupled nematic systems
We use an infinite-range Maier-Saupe model, with two sets of local
quadrupolar variables and restricted orientations, to investigate the global
phase diagram of a coupled system of two nematic subsystems. The free energy
and the equations of state are exactly calculated by standard techniques of
statistical mechanics. The nematic-isotropic transition temperature of system A
increases with both the interaction energy among mesogens of system B, and the
two-subsystem coupling . This enhancement of the nematic phase is manifested
in a global phase diagram in terms of the interaction parameters and the
temperature . We make some comments on the connections of these results with
experimental findings for a system of diluted ferroelectric nanoparticles
embedded in a nematic liquid-crystalline environment.Comment: 11 pages, 3 figures, to appear in Volume 42 of the Brazilian Journal
of Physic
CIRURGIA PRÉ PROTÉTICA COM INSTALAÇÃO DE PRÓTESE TOTAL IMEDIATA
Introdução: Com Intuito de mostrar o quanto o sorriso é importante para a vida do paciente nesse estudo relatamos um caso clinico de cirurgia Pré- protética para instalação de prótese total imediata. Após uma extração múltipl
High Levels of Heavy Metal(loid)s Related to Biliary Hyperplasia in Hedgehogs (Erinaceus europaeus)
Simple Summary Heavy metal(loid)s are hazardous substances for humans, animals and ecosystems. The liver is one of the most affected organs, presenting lesions after being acutely or chronically exposed to these substances. In this study, hepatic metal(loid)s' concentrations were associated with biliary hyperplasia, which was the most common hepatic lesion found in a group of western-European hedgehogs from rescue centres in Portugal. With exception of arsenic (As), all metal(loid)s were present in higher concentrations in animals with biliary hyperplasia. Further research is necessary to support these results and clarify the molecular mechanisms that lead to hepatic lesions provoked by these compounds. Heavy metal(loid) pollution of ecosystems is a current One Health problem. The liver is one of the most affected organs in cases of acute or chronic exposure to abnormal amounts of these substances, inducing histopathologic lesions. In order to assess the influence of heavy metal(loids), forty-five European hedgehogs (Erinaceus europaeus) were submitted to necropsy, and liver samples were collected for a routine histopathology exam and metal(loid)s determination (As, Cd, Co, Cr, Cu and Pb) by ICP-MS. Age was estimated during the necropsy exam. Biliary hyperplasia was the most frequent lesion observed (16/45; 35.56%). No statistically significant associations were found between biliary hyperplasia and age or sex. Metal(loid)s' concentrations were higher in animals with biliary hyperplasia (except for As). There was a statistically significant difference for both Cd and Co. For As, Cd and Co, cubs and juveniles animals showed significantly lower concentrations than elder individuals. Only for Pb were significant differences found between females and males. As described in the literature, exposure to metal(loid)s may be a cause of biliary hyperplasia, although further research (including the use of biochemical methods) is needed to support these results. To the authors' knowledge, this is the first report of this association in hedgehogs.This work was supported by National Funds by the Portuguese Foundation for Science and Technology (FCT). The authors of the research unit CITAB (CJB and PAO) received funding from FCT-reference of the project: UIDB/04033/2020. The author of the research unit CECAV (FS) received funding from FCT-reference of the project: UIDB/CVT/00772/2020. CJB was supported by FCT due to the phD scholarship 2021.04520.BD. TLM was supported by UIDB/CVT/00772/2020 and LA/P/0059/2020 funded by FCT
Cardiac evaluation after experimental intoxication by Amorimia rigida (Malpighiaceae) extracts in rabbits
Clinical and laboratory changes were evaluated in rabbits after intoxication by Amorimia rigida, a plant that causes sudden death. Nine New Zealand male rabbits, averaging 3.54 kg, were categorized into three groups (n = 3) and received, for eight consecutive days, the equivalent of 30 g/kg dry matter of A. rigida water-soluble (SG) and water-insoluble (IG) extracts via nasoesophageal route. The control group received water. There were no alterations in creatine kinase enzyme (CK), CK myocardial fraction (CKMB) or troponine I (cTnI). None of the animals had clinical or electrocardiographic (conventional and Holter) alterations. There were progressive decreases in the left ventricular ejection fraction and systolic fractional shortening. Doppler echocardiography alterations suggested a systolic dysfunction in the SG and IG groups and diastolic dysfunction in IG group. It was concluded that the soluble and insoluble extracts of A. rigida cause deficit of cardiac function
Application of amorphous carbon based materials as antireflective coatings on crystalline silicon solar cells
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)We report on the investigation of the potential application of different forms of amorphous carbon (a-C and a-C:H) as an antireflective coating for crystalline silicon solar cells. Polymeric-like carbon (PLC) and hydrogenated diamond-like carbon films were deposited by plasma enhanced chemical vapor deposition. Tetrahedral amorphous carbon (ta-C) was deposited by the filtered cathodic vacuum arc technique. Those three different amorphous carbon structures were individually applied as single antireflective coatings on conventional (polished and texturized) p-n junction crystalline silicon solar cells. Due to their optical properties, good results were also obtained for double-layer antireflective coatings based on PLC or ta-C films combined with different materials. The results are compared with a conventional tin dioxide (SnO(2)) single-layer antireflective coating and zinc sulfide/magnesium fluoride (ZnS/MgF(2)) double-layer antireflective coatings. An increase of 23.7% in the short-circuit current density, J(sc), was obtained using PLC as an antireflective coating and 31.7% was achieved using a double-layer of PLC with a layer of magnesium fluoride (MgF(2)). An additional increase of 10.8% was obtained in texturized silicon, representing a total increase (texturization + double-layer) of about 40% in the short-circuit current density. The potential use of these materials are critically addressed considering their refractive index, optical bandgap, absorption coefficient, hardness, chemical inertness, and mechanical stability. (C) 2011 American Institute of Physics. [doi:10.1063/1.3622515]1104Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Brazilian financial research agency MCTConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq
Analysis of the Performance of a Standardized Method for the Polishing of Methacrylic Resins
Adhesion of micro-organisms to resin surface may be caused by inadequate polishing. Most of the studies published in literature are relative to manually prepared samples and do not take into account that test repeatability is not guaranteed a priori since skills may change from one operator to another and the quality of the work done by the same expert operator may depend on “human” factors such as the level of attention, wrist trembling, etc
- …