54 research outputs found

    Stability analysis of a hypothalamic-pituitary-adrenal axis model with inclusion of glucocorticoid receptor and memory

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    This paper analyzes a four-dimensional model of the hypothalamic-pituitary-adrenal (HPA) axis that includes the influence of the glucocorticoid receptor in the pituitary. Due to the spatial separation between the hypothalamus, pituitary and adrenal glands, distributed time delays are introduced in the mathematical model. The existence of the positive equilibrium point is proved and a local stability and bifurcation analysis is provided, considering several types of delay kernels. The fractional-order model with discrete time delays is also taken into account. Numerical simulations are provided to illustrate the effectiveness of the theoretical findings.Comment: 9 page

    Airway inflammation and inflammatory biomarkers

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    Universitatea Lucian Blaga Sibiu, Facultatea de Medicină, Spitalul Clinic de Pediatrie Sibiu, Centrul de Cercetări şi Telemedicină în Bolile Neurologice la copil, Universitatea de Stat de Medicină şi Farmacie „Nicolae Testemiţanu”, Departamentul PediatrieIntroduction. Airway inflammation is a common feature of many diseases. Its repercussions can be discovered in many aspects of the disease, therefore finding the biomarker or combination of biomarkers to define it continues to be challenging. The scientific material and methods used are the review of current literature data, controversies, discordances and peculiarities of respiratory tract inflammation and biomarkers capable to assess it. The results are centered on those biomarkers capable to capture inflammation from as many angles as possible, with impact not only on the pathogenesis of the disease but also with clinical, evolution, therapeutic and monitoring implications. Conclusions. For airway inflammation many biomarkers are useful, some define the disease as a whole, some are defining for certain aspects or endotypes. The winning combination proposed by many authors appears to be a panel of biomarkers which captures as many aspects as possible for each entity, but is usually difficult to find

    Individual alpha peak frequency, an important biomarker for live Z-Score training neurofeedback in adolescents with learning disabilities

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    Learning disabilities (LDs) have an estimated prevalence between 5% and 9% in the pediatric population and are associated with difficulties in reading, arithmetic, and writing. Previous electroencephalography (EEG) research has reported a lag in alpha-band development in specific LD phenotypes, which seems to offer a possible explanation for differences in EEG maturation. In this study, 40 adolescents aged 10–15 years with LDs underwent 10 sessions of Live Z-Score Training Neurofeedback (LZT-NF) Training to improve their cognition and behavior. Based on the individual alpha peak frequency (i-APF) values from the spectrogram, a group with normal i-APF (ni-APF) and a group with low i-APF (li-APF) were compared in a pre-and-post-LZT-NF intervention. There were no statistical differences in age, gender, or the distribution of LDs between the groups. The li-APF group showed a higher theta absolute power in P4 (p = 0.016) at baseline and higher Hi-Beta absolute power in F3 (p = 0.007) post-treatment compared with the ni-APF group. In both groups, extreme waves (absolute Z-score of ≥1.5) were more likely to move toward the normative values, with better results in the ni-APF group. Conversely, the waves within the normal range at baseline were more likely to move out of the range after treatment in the li-APF group. Our results provide evidence of a viable biomarker for identifying optimal responders for the LZT-NF technique based on the i-APF metric reflecting the patient’s neurophysiological individualit

    In silico study of PEI-PEG-squalene-dsDNA polyplex formation: the delicate role of the PEG length in the binding of PEI to DNA

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    Using a two step simulation protocol the atomistic interactions between PEG and b-PEI and the effect of these interactions on DNA binding were determined

    Enhancing the effects of neurofeedback training: the motivational value of the reinforcers

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    The brain activity that is measured by electroencephalography (EEG) can be modified through operant conditioning, specifically using neurofeedback (NF). NF has been applied to several disorders claiming that a change in the erratic brain activity would be accompanied by a reduction of the symptoms. However, the expected results are not always achieved. Some authors have suggested that the lack of an adequate response may be due to an incorrect application of the operant conditioning principles. A key factor in operant conditioning is the use of reinforcers and their value in modifying behavior, something that is not always sufficiently taken into account. This work aims to clarify the relevance of the motivational value versus the purely informational value of the reinforcer. In this study, 113 subjects were randomly assigned two different reinforcer conditions: a selected reinforcer—the subjects subjectively selected the reinforcers—or an imposed reinforcer— the reinforcers were assigned by the experimenter—and both groups undertook NF sessions to enhance the sensorimotor rhythm (SMR). In addition, the selected reinforcer group was divided into two subgroups: one receiving real NF and the other one sham NF. There were no significant differences between the groups at baseline in terms of SMR amplitude. After the intervention, only those subjects belonging to the selected reinforcer group and receiving real NF increased their SMR. Our results provide evidence for the importance of the motivational value of the reinforcer in Neurofeedback succes

    THE DETERMINANTS OF E-GOVERNMENT RELATIONAL MODELS CONSTRUCTION: INTERACTION, COMMUNICATION, PARTICIPATION AND COLLABORATION

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    In recent decades the integrating approach of new information and communication technologies in the public sector grew faster. Worldwide, most states have made and still make substantiate efforts towards the coherent strategies implementation in order to favor the complex process of integrating the new information and communication technologies. Regardless of the objectives - maximizing efficiency, increase transparency in the decision process, improve service quality or citizen participation in decision making - what we call today e-Government has become an essential mechanism in administrative reforms, independent of aggregation level. The article presents an analysis of the factors that define the outline of the e-government relational model

    PRACTICAL RECOMMENDATIONS OF DATA PREPROCESSING AND GEOSPATIAL MEASURES FOR OPTIMIZING THE NEUROLOGICAL AND OTHER PEDIATRIC EMERGENCIES MANAGEMENT

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    Time management, optimal and timed determination of emergency severity as well as optimizing the use of available human and material resources are crucial areas of emergency services. A starting point for achieving these optimizations can be considered the analysis and preprocess of real data from the emergency services. The benefits of performing this method consist in exposing more useful structures to data modelling algorithms which consequently will reduce overfitting and improves accuracy. This paper aims to offer practical recommendations for data preprocessing measures including feature selection and discretization of numeric attributes regarding age, duration of the case, season, period, week period (workday, weekend) and geospatial location of neurological and other pediatric emergencies. An analytical, retrospective study was conducted on a sample consisting of 933 pediatric cases, from UPU-SMURD Sibiu, 01.01.2014 – 27.02.2017 period

    Identification of Probiotic Strains from Human Milk in Breastfed Infants with Respiratory Infections

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    Isolation and industrial exploitation of probiotics from human milk is a goal for worldwide milk biotechnology centres because of their modulation effect on the immune system in infants and adults. In the proposed study we have analysed fermentation patterns of Lactobacilli isolated from human milk, the reliability of API 50 CH carbohydrate fermentation system and a possible link between lactose concentrations and fermentation profiles on carbohydrates. We had succesfully identified three species of Lactobacillus (paracasei ssp paracasei, fermentum, acidophilus) and one unsatisfactory identification of Lactoccocus lactis ssp lactis. These strains had different carbohydrate fermentation patterns but with common characteristics and showed no statistically significant correlations between their carbohydrate metabolic trends and lactose concentrations in the milk samples

    MATÉRIAUX COMPACTS MAGNÉTIQUES DOUX OBTENUS À L'ÉTAT NANOCRISTALLIN À PARTIR DE POUDRES D'ALLIAGES Ni-Fe-X ISSUES DE MÉCANOSYNTHÈSE

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    Cette thèse est consacrée à 1) la préparation d'alliages magnétiques base nickel à l'état nanocristallin 2) à l'élaboration de compacts nanocristallins 3) la caractérisation des propriétés physiques et particulièrement magnétiques douces des poudres et des compacts en fonction des paramètres d'élaboration. L'élaboration des alliages magnétiques doux a été réalisée par broyage mécanique de haute énergie à sec ou en utilisant le benzène comme agent de contrôle, conduisant à des matériaux nanocristallins. Les conditions optimales de synthèse des poudres ont été déduites pour les systèmes Ni3Fe, 79Ni16Fe5Mo et 77Ni14Fe5Cu4Mo et un protocole contenant broyage mécanique par voie humide suivi d'un traitement thermique est proposé. Ce protocole a permis de préparer des cristallites de taille ajustable de 12 à 30 nm selon la durée et le mode de broyage choisi. La taille des particules obtenues a pu être contrôlée par le choix de la quantité de benzène utilisée. Les propriétés intrinsèques des poudres tant microstructurales que structurales, magnétiques et thermiques ont été analysées en fonction des conditions d'élaboration. Une combinaison de techniques (DSC, TG, IR et MS) nous a permis d'expliquer la présence et la décomposition de benzène sur la surface des poudres broyées. Deux méthodes ont été mises en oeuvre pour élaborer des compacts nanocristallins magnétiques doux : le frittage plasma et la préparation de matériaux composites. Les conditions optimales de compactage de poudres magnétiques ont été déterminées en variant la pression de compactage, le taux de polymère, la méthode de polymérisation, la taille de particules, etc. Les propriétés physiques dynamiques ont été étudiées jusqu'à des fréquences de 100 kHz et une induction maximale de 0,05 et 0,1 T. Des valeurs typiques de la perméabilité relative initiale comprises entre 30 et 50 et des pertes comprises entre 300 et 7000 W/kg (f = 50 kHz et Bmax = 0,1 T) ont été obtenues et ont été discutées en fonction des paramètres de compactage. Pour les compacts obtenus par frittage plasma, des perméabilités relatives maximales comprises entre 200 et 900 ont été obtenues en variant la température et la durée du processus. Un traitement thermique post frittage (450 C/4 h) sous H2 conduit à une diminution du champ coercitif d'environ 50 % et une augmentation de la perméabilité de jusqu'à 600 % en conservant la structure nanocristalline de compacts. Les propriétés magnétiques des compacts composites ont été modélisées sur la base du modèle de Bruggemann.This thesis is devoted to 1) the preparation of magnetic nickel-based alloys in nanocrystalline state 2) the preparation of nanocrystalline compacts 3) the characterization of physical and in particularly soft magnetic properties of the powder and compacts as a functions of their elaboration parameters. The development of soft magnetic alloys has been achieved by dry or wet high energy milling using benzene as process control agent, leading to nanocrystalline materials. The optimum conditions for powder synthesis have been derived for systems Ni3Fe, 79Ni16Fe5Mo and 77Ni14Fe5Cu4Mo and a protocol containing mechanical milling followed by heat treatment is proposed. This protocol has allowed the preparation of powder having crystallite size tunable from 12-30 nm depending on the milling time and chosen milling method. The as obtained particles size could be controlled by choosing the amount of benzene used. The intrinsic properties of powders as microstructural and structural, magnetic and thermal have been analyzed according to the preparations conditions. A combination of (DSC, TG, IR and MS) techniques has allowed us to explain the presence and decomposition of benzene on the milled powders surface. Two methods have been implemented to develop nanocrystalline soft magnetic compact: spark plasma sintering and preparation of composite materials. The optimum conditions for compaction of magnetic powders were determined by varying the compaction pressure, the polymer quantity, the polymerization method, the particle size, etc.. The dynamic physical properties have been investigated up to frequencies of 100 kHz and a maximum induction level of 0.05 and 0.1 T. Typical values of initial relative permeability between 30 and 50 and core losses between 300 and 7000 W/kg (f = 50 kHz and Bmax = 0.1 T) were obtained and have been discussed in terms of compaction parameters. For the spark plasma sintered compacts, maximum relative permeability between 200 and 900 were obtained by varying the sintering temperature and process duration. A post sintering heat treatment (450 C/4 h) under H2 leads to a decrease in the coercive field of about 50% and increased permeability of up to 600 % conserving the nanocrystalline structure of the compacts. The magnetic properties of the composite compacts were modeled on the basis of the Bruggemann model.GRENOBLE1-BU Sciences (384212103) / SudocSudocFranceF

    Identification of Factors Associated with Mortality in the Elderly Population with SARS-CoV-2 Infection: Results from a Longitudinal Observational Study from Romania

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    The progression of SARS-CoV-2 infection has been linked to a hospitalization rate of 20%. The susceptibility of SARS-CoV-2 infection increases with age, resulting in severe and atypical clinical forms of the disease. The severity of SARS-CoV-2 infection in the elderly population can be attributed to several factors, including the overexpression of angiotensin-converting enzyme 2 (ACE2) receptors, immunosenescence, and alterations in the intestinal microbiota that facilitate the cytokine storm. In light of these observations, we conducted a retrospective analysis based on prospectively collected data between 23 December 2021 and 30 April 2022 (the fourth wave of SARS-CoV-2 infection). We analyzed patients aged over 60 years who were hospitalized in a county hospital in Romania. The primary objective of our study was to assess the risk factors for an unfavorable outcome, while the secondary objective was to assess the clinical and baseline characteristics of the enrolled patients. We included 287 cases with a complete electronic medical record from this available cohort of patients. We aimed to retrospectively evaluate a group of 127 patients that progressed, unfortunately, toward an unfavorable outcome versus 160 patients with a favorable outcome. We used the Combined Ordinal Scale of Severity that combines the WHO ordinal scale and the degrees of inflammation to assess the severity of the patients at the time of the initial assessment. The age group between 70 and 79 years had the highest percentage, accounting for 48.0%—61 patients, of the deceased patients. We noted statistically significant differences between groups related to other cardiovascular diseases, nutritional status, hematological diseases, other neurological/mental or digestive disorders, and other comorbidities. Regarding the nutritional status of the patients, there was a statistically significant unfavorable outcome for all the age groups and the patients with a BMI > 30 kg/m2, p = 0.004. The presence of these factors was associated with an unfavorable outcome. Our results indicate that with the presence of cough, there was a statistically significant favorable outcome in the age group over 80 years, p ≤ 0.049. In terms of the presence of dyspnea in all groups of patients, it was associated with an unfavorable outcome, p ≤ 0.001. In our study, we analyzed laboratory test results to assess the level of inflammation across various WHO categories, focusing on the outcome groups determined by the average values of specific biomarkers. Our findings show that, with the exception of IL-6, all other biomarkers tend to rise progressively with the severity of the disease. Moreover, these biomarkers are significantly higher in patients experiencing adverse outcomes. The differences among severity categories and the outcome group are highly significant (p-values < 0.001). CART algorithm revealed a specific cut-off point for the WHO ordinal scale of 4 to stand out as an important reference value for patients at a high risk of developing critical forms of COVID-19. The high death rate can be attributed to proinflammatory status, hormonal changes, nutritional and vitamin D deficiencies, comorbidities, and atypical clinical pictures
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