Search results for "Time course"
showing 10 items of 58 documents
Time course of human 40 Hz EEG activity accompanying P3 responses in an auditory oddball paradigm
1997
In order to quantify the time course of auditory P3-related gamma activity, root mean square (RMS) values were calculated from band-filtered (30-45 Hz) target and non-target responses in an auditory oddball experiment. Evoked (phase locked) gamma activity was evaluated from the time domain averages, whereas induced (not necessarily phase locked) activity was analyzed on the basis of single trials. Gamma RMS values were integrated across different time windows, namely the prestimulus, N50/P50, N100, pre P3, P3 and post P3 window. The single trial P3 window hereby was defined by a maximum amplitude criterion. In accordance with other studies, we found a pronounced increase of evoked gamma act…
A Simple Cardiovascular Model for the Study of Hemorrhagic Shock
2020
Hemorrhagic shock is the number one cause of death on the battlefield and in civilian trauma as well. Mathematical modeling has been applied in this context for decades; however, the formulation of a satisfactory model that is both practical and effective has yet to be achieved. This paper introduces an upgraded version of the 2007 Zenker model for hemorrhagic shock termed the ZenCur model that allows for a better description of the time course of relevant observations. Our study provides a simple but realistic mathematical description of cardiovascular dynamics that may be useful in the assessment and prognosis of hemorrhagic shock. This model is capable of replicating the changes in mean …
Characteristics of haloethylene-induced acetonemia in rats.
1980
A series of halogenated ethylenes (vinyl chloride, vinylidene fluoride,cis- andtrans-1,2-dichloroethylene, perchloroethylene) induces increased acetone exhalation in rats. Exposures of differently pre-treated rats to vinylidene fluoride suggest that a metabolite of the haloethylene must be envolved in eliciting this formation of acetone. This conclusion is based on (a) dependence of acetone exhalation on the concentration of vinylidene fluoride, (b) effect of inducing agents, (c) effect of pyrazol, a metabolic inhibitor, (d) effect of cysteine, (e) effect of hypoxia and (f) the time course of acetone exhalation.
Pharmacological preconditioning in global cerebral ischemia
2004
Single dose 3-nitropropionic acid (3-NPA) 24 hr before global ischemia improves neuronal survival in both, neocortex and hippocampus (‘chemical preconditioning’). Neuronal survival after transient global ischemia requires new protein synthesis during recovery, especially of those with anti-apoptotic function. Bcl-2-protein is expressed in neurons that survive cerebral ischemia and may parallel the time course of tolerance after ischemic preconditioning. With this study we examined whether differences in bcl-2-protein expression compared to baseline may be involved in the induction of ischemic tolerance using 3-NPA.
The week after running a marathon: Effects of running vs elliptical training vs resting on neuromuscular performance and muscle damage recovery
2021
Our aim was to compare the effects of two exercise modalities vs resting on the time course of neuromuscular performance and muscle damage recovery during the week after running a marathon. Sixty-four finishers from a road marathon completed the study (54 men and 10 women; 39 ± 4 years; 3 h 35 min ± 21 min). The day before the race, within 15 min after finishing the marathon and at 24, 48, 96, 144 and 192 h postrace, lactate dehydrogenase and creatine kinase were analysed. Participants also performed a squat jump (SJ) test before and after the marathon and at 48, 96 and 144 h postrace. On their arrival to the finish line, participants were randomized into one of the three intervention group…
Stress and Recovery Responses during a 105-day Ground-based Space Simulation
2014
The present study analysed the time course of the psychological process of stress and recovery in six healthy male volunteers during the Mars 105 experimentation, a 105-day ground-based space analogue. The multidimensional assessment of stress and recovery responses showed that stress levels decreased significantly throughout the 105-day isolated and confined extreme (ICE) experiment, especially on its social dimension. In line with previous studies, Fatigue showed a global and progressive reduction. The present results suggest that ICE exposure may not systematically induce stress overload and impaired psychological states. To optimize adaptation to ICE conditions, further improvements in …
Significant divergences between the temporal structure of the behavior in Wistar and in the spontaneously more anxious DA/Han strain of rats tested i…
2013
Abstract The aim of present research is to study the temporal structure of the behavior in two strains of rats with different basal level of emotionality. To this purpose, the temporal profile of the behavior in Wistar rat and in the spontaneously more anxious DA/Han strain was analyzed in the Elevated Plus Maze. Both quantitative and multivariate t-pattern analyses were carried out. In comparison with Wistar, DA/Han subjects showed a significant reduction of the permanence in open arm and a significant increase of the time spent in the central platform of the maze. Mean frequencies of each behavioral element showed significant modifications both in open and in closed arm. Multivariate t-pa…
3He-MRI-based measurements of intrapulmonarypO2 and its time course during apnea in healthy volunteers: first results, reproducibility, and technical…
2000
We applied a recently developed method of following the time course of the intrapulmonary oxygen partial pressure p(O2)(t) during apnea by (3)He MRI to healthy volunteers. Using two imaging series with different interscan times during two breathholds (double acquisition technique), relaxation of (3)He due to paramagnetic oxygen and depolarization by RF pulses were discriminated. In all four subjects, the temporal evolution of p(O2) was found to be linear, and was described by an initial partial pressure p(0) and a decrease rate R. Also, regional differences of both p(0) and R were observed. A correlation between p(0) and R was apparent. Finally, we discuss limitations of the double acquisit…
Serial assessments of microvascular obstruction by contrast-enhanced magnetic resonance predict contractile recovery and clinical outcome after reper…
2015
AIMS The purpose of the study was to investigate, using cardiac magnetic resonance (CMR), the presence and time course of microvascular obstruction (MO) in patients with acute myocardial infarction (AMI), and to test its relationship with cardiac remodeling and clinical outcomes. METHODS AND RESULTS 53 patients with AMI and successful percutaneous reperfusion underwent CMR examination at four separate timepoints: within the first 48 hours, at 10 days, at six and twelve months after infarction. MO was quantified immediately (early imaging) and 10 minutes (late imaging) after contrast administration in each session. The extent of MO decreased from early to late imaging at both the first and t…
Deterioration of organization in the first minutes of atrial fibrillation: A beat-to-beat analysis of cycle length and wave similarity
2007
Deterioration of AF Organization. Introduction: It has been recently suggested that many episodes of atrial fibrillation (AF) may be partially organized at the onset and thus more suitable for antitachycardia pacing therapy. Nevertheless, the time course of organization in the first minutes of AF has not been quantified yet. Methods and Results: Twenty episodes of paroxysmal AF were studied. Electrograms were recorded from the right atrium (RA), distal (CSd), and proximal coronary sinus (CSp). The time course of AF cycle length (AFCL) and the regularity of wave morphology (similarity index S) were beat-to-beat measured at each recording site during the first 7 minutes of AF. AFCL and S show…