14 research outputs found
Thermodynamic Properties of Ternary Liquid Mixtures Containing <i>o</i>‑Chlorotoluene: Excess Molar Volumes and Excess Isentropic Compressibilities
Densities and speeds of sound of
ternary <i>o</i>-chlorotoluene
(1) + tetrahydropyran (2) + benzene or toluene or <i>o</i>-xylene (3) mixtures and their sub-binaries <i>o</i>-chlorotoluene
(1) + toluene or <i>o</i>-xylene (2) at (298.15, 303.15,
and 308.15) K have been measured, and of tetrahydropyran (1) + benzene
or toluene or <i>o</i>-xylene (2) mixtures at (298.15 and
303.15) K and 0.1 MPa. Excess molar volumes, <i>V</i><sub>123</sub><sup>E</sup> and <i>V</i><sup>E</sup>, and excess isentropic compressibilities,
(κ<sub>S</sub><sup>E</sup>)<sub>123</sub> and κ<sub>S</sub><sup>E</sup>, have been computed from experimental data. The <i>V</i><sub>123</sub><sup>E</sup> for <i>o</i>-chlorotoluene (1) + tetrahydropyran (2) + <i>o</i>-xylene (3) and (κ<sub>S</sub><sup>E</sup>)<sub>123</sub> for <i>o</i>-chlorotoluene
(1) + tetrahydropyran (2) + benzene or toluene or <i>o</i>-xylene (3) are negative over the entire mole fraction of 1 and 2.
However, the sign and magnitude of <i>V</i><sub>123</sub><sup>E</sup> for <i>o</i>-chlorotoluene (1) + tetrahydropyran (2) + benzene or toluene
(3) mixtures are dictated by the relative proportion of the constituents.
The excess functions have been analyzed in terms of Graph theory,
Prigogine–Flory–Patterson theory, and Sanchez and Lacombe’s
theories
Spatio-temporal changes in glutathione and thioredoxin redox couples during ionizing radiation-induced oxidative stress regulate tumor radio-resistance
<div><p></p><p>Ionizing radiation (IR)-induced oxidative stress in tumor cells is effectively managed by constitutive and inducible antioxidant defense systems. This study was initiated to understand the relative contribution of different redox regulatory systems in determining the tumor radio-resistance. In this study, human T-cell lymphoma (Jurkat) cells were exposed to IR (4 Gy) and monitored for the spatio-temporal changes in cellular redox regulatory parameters. We monitored the changes in the levels of reactive oxygen species (ROS) (total, mitochondrial, primary, and secondary), thiols (total, surface, and intracellular), GSH/GSSG ratio, antioxidant enzyme activity viz. thioredoxin (Trx), Trx reductase (TrxR), glutathione peroxidase, and glutathione reductase with respect to time. We have also measured protein glutathionylation. We observed that tumor cells mount a biphasic response after IR exposure which can be divided into early (0–6 h) and late (16–48 h) responses in terms of changes in cellular redox parameters. During early response, constitutively active GSH and Trx systems respond to restore cellular redox balance to pre-exposure levels and help in activation of redox-sensitive transcription factor Nrf-2. During late response, increase in the levels of antioxidants GSH and Trx rescue cells against IR-mediated damage. We observed that disruption of either glutathione or thioredoxin metabolism led to partial impairment of ability of cells to survive against IR-induced damage. But simultaneous disruption of both the pathways significantly increased radio sensitivity of Jurkat cells. This highlighted the importance of these two antioxidant pathways in regulating redox homeostasis under conditions of IR-induced oxidative stress.</p></div
Physiological fetal datas in time series (n = 8).
<p>Physiological fetal datas in time series (n = 8).</p
Correlation curve between FSI<sub>min</sub> and base deficit.
<p>Correlation curve between FSI<sub>min</sub> and base deficit.</p
FSI variation according to pH ranges during occlusion.
<p>FSI variation according to pH ranges during occlusion.</p
Correlation between hemodynamic, gazometric parameters and FSI<sub>min</sub> during occlusion.
<p>Correlation between hemodynamic, gazometric parameters and FSI<sub>min</sub> during occlusion.</p
Correlation curve between FSI<sub>min</sub> and arterial pH.
<p>Correlation curve between FSI<sub>min</sub> and arterial pH.</p
Fetal Stress Index according to pH.
<p>FSI<sub>min</sub> according to pH during occlusion (n = 8). The data are presented as median ± interquartile. *: p<0.05 versus pH> 7.20.</p
A new analysis of heart rate variability in the assessment of fetal parasympathetic activity: An experimental study in a fetal sheep model
<div><p>Analysis of heart rate variability (HRV) is a recognized tool in the assessment of autonomic nervous system (ANS) activity. Indeed, both time and spectral analysis techniques enable us to obtain indexes that are related to the way the ANS regulates the heart rate. However, these techniques are limited in terms of the lack of thresholds of the numerical indexes, which is primarily due to high inter-subject variability. We proposed a new fetal HRV analysis method related to the parasympathetic activity of the ANS. The aim of this study was to evaluate the performance of our method compared to commonly used HRV analysis, with regard to i) the ability to detect changes in ANS activity and ii) inter-subject variability. This study was performed in seven sheep fetuses. In order to evaluate the sensitivity and specificity of our index in evaluating parasympathetic activity, we directly administered 2.5 mg intravenous atropine, to inhibit parasympathetic tone, and 5 mg propranolol to block sympathetic activity. Our index, as well as time analysis (root mean square of the successive differences; RMSSD) and spectral analysis (high frequency (HF) and low frequency (LF) spectral components obtained via fast Fourier transform), were measured before and after injection. Inter-subject variability was estimated by the coefficient of variance (%CV). In order to evaluate the ability of HRV parameters to detect fetal parasympathetic decrease, we also estimated the effect size for each HRV parameter before and after injections. As expected, our index, the HF spectral component, and the RMSSD were reduced after the atropine injection. Moreover, our index presented a higher effect size. The %CV was far lower for our index than for RMSSD, HF, and LF. Although LF decreased after propranolol administration, fetal stress index, RMSSD, and HF were not significantly different, confirming the fact that those indexes are specific to the parasympathetic nervous system. In conclusion, our method appeared to be effective in detecting parasympathetic inhibition. Moreover, inter-subject variability was much lower, and effect size higher, with our method compared to other HRV analysis methods.</p></div
Blood gases before and after injection of atropine and propranolol, respectively.
<p>The results are presented as median values (1<sup>st</sup>–3<sup>rd</sup> quartiles).</p