Search results for "physiologic"

Fine-tuning scaffolds for tissue regeneration: effects of formic acid processing on tissue reaction to silk fibroin

2010

Formic acid (FA) plays a key role in the preparation of silk fibroin (SF) scaffolds from cocoons of Bombyx mori and is used for fibre distribution. In this study, we used a subcutaneous implantation model in Wistar rats to examine SF scaffolds prepared by treating the degummed cocoon with FA for either 30 or 60 min. The tissue reaction and inflammatory response to SF was assessed by qualitative histology at intervals from 3 to 180 days. Additionally, dynamic biomaterial-induced vascularization and biomaterial degradation were quantified using a technique for analysing an image of the entire implanted biomaterial. Varying the FA treatment time led to different scaffold morphologies and resul…

34. Accomplishing the requirements within the new decree 159/2016: Comparative study of eddy currents induced in a human phantom moving near differen…

2018

Purpose In order to provide adequate risk-reducing procedures for MRI personnel (radiographers, anaesthetists, physicists, nurses, technicians, cleaners, etc.), different studies have been developed in the past years. Further to those, in the present work risk assessment concerned with currents induced by non-uniform static magnetic fields in MRI operators performing different tasks in proximity of the scanner has been investigated across a set of different 1.5 T MRI scanners. Methods The first step has been to empirically map the magnetic field around the different scanners and to select a proper adult human body as a heterogeneous volume conductor model. Then, upon observing the way tasks…

Separating mismatch negativity (MMN) response from auditory obligatory brain responses in school-aged children

2013

Mismatch negativity (MMN) overlaps with other auditory event-related potential (ERP) components. We examined the ERPs of 50 9- to 11-year-old children for vowels /i/, /y/ and equivalent complex tones. The goal was to separate MMN from obligatory ERP components using principal component analysis and equal probability control condition. In addition to the contrast of the deviant minus standard response, we employed the contrast of the deviant minus control response, to see whether the obligatory processing contributes to MMN in children. When looking for differences in speech deviant minus standard contrast, MMN starts around 112 ms. However, when both contrasts are examined, MMN emerges for …

The Role of Gender in Teachers’ Perceived Stress and Heart Rate

2008

Gender differences in cardiovascular variables in response to laboratory stressors have been described. In real situations, although occupational stress is considered one of the major causes of cardiovascular diseases, there are few studies that follow a psychophysiological approach, such as in a work context. In these settings, excessive environmental demands might produce nonadaptive emotional responses, depending on the way people perceive their work settings. Concretely, there are few published studies that take into account the changes of perceived stress (PS) and/or heart rate (HR) considering the ecological moment. Thus, our interest was to study the changes of both variables during…

Predictors of decline in self-assessments of health among older people--a 5-year longitudinal study.

2001

Within the framework of the Evergreen project we examined how changes in several indicators of health and functioning and physical activity predicted a decline in self-assessments of health evaluated over a 5-year period in older people by two different measurements: self-rated health (SRH) and self-assessed change in health (SACH). The study group comprised all 75-year-old persons born in 1914 (N = 382) and living in Jyvaskyla, a town in central Finland. At baseline in 1989, 91.6%, and at follow-up 5 years later in 1994, 87.3% of those eligible participated in the interview and 77.2 and 71.3%, respectively, in the examinations in the study centre, focusing on different domains of health an…

Synthetic lethal metabolic targeting of cellular senescence in cancer therapy.

2013

Activated oncogenes and anticancer chemotherapy induce cellular senescence, a terminal growth arrest of viable cells characterized by S-phase entry-blocking histone 3 lysine 9 trimethylation (H3K9me3). Although therapy-induced senescence (TIS) improves long-term outcomes, potentially harmful properties of senescent tumour cells make their quantitative elimination a therapeutic priority. Here we use the Eµ-myc transgenic mouse lymphoma model in which TIS depends on the H3K9 histone methyltransferase Suv39h1 to show the mechanism and therapeutic exploitation of senescence-related metabolic reprogramming in vitro and in vivo. After senescence-inducing chemotherapy, TIS-competent lymphomas but …

Relevance of Oxygen Concentration in Stem Cell Culture for Regenerative Medicine

2019

The key hallmark of stem cells is their ability to self-renew while keeping a differentiation potential. Intrinsic and extrinsic cell factors may contribute to a decline in these stem cell properties, and this is of the most importance when culturing them. One of these factors is oxygen concentration, which has been closely linked to the maintenance of stemness. The widely used environmental 21% O2 concentration represents a hyperoxic non-physiological condition, which can impair stem cell behaviour by many mechanisms. The goal of this review is to understand these mechanisms underlying the oxygen signalling pathways and their negatively-associated consequences. This may provide a rationale…

Sensory preconditioning in newborn rabbits: from common to distinct odor memories.

2013

Brief Communication; International audience; This study evaluated whether olfactory preconditioning is functional in newborn rabbits and based on joined or independent memory of odorants. First, after exposure to odorants A+B, the conditioning of A led to high responsiveness to odorant B. Second, responsiveness to B persisted after amnesia of A. Third, preconditioning was also functional with two overlapping pairs of odorants (A+B and B+C) and amnesia of one odorant did not affect memory of the others. Thus, incidental pairing of odorants allows reinforcement of one odorant to implicitly reinforce the others, the bond then vanishes, and the memory of each element becomes independent.

Corrigendum: Both attention and prediction are necessary for adaptive neuronal tuning in sensory processing

2017

Neurobiological foundations of multisensory processing integration in people with autism spectrum disorders: The role of the medial prefrontal cortex

2014

This review aims to relate the sensory processing problems in people with Autism spectrum disorders (ASD), especially Multisensory interaction (MSI), to the role of the medial prefrontal cortex (mPFC) by exploring neuroanatomical findings; brain connectivity and Default Network (DN); global or locally directed attention; and temporal multisensory binding. The mPFC is part of the brain’s DN, which is deactivated when attention is focused on a particular task and activated on rest when spontaneous cognition emerges. In those with ASD, it is hypoactive and the higher the social impairment the greater the atypical activity. With an immature DN, cross-modal integration is impaired, resulting in …