675 research outputs found
Mind-body relationships in elite apnea divers during breath holding: a study of autonomic responses to acute hypoxemia
The mental control of ventilation with all associated phenomena, from relaxation to modulation of emotions, from cardiovascular to metabolic adaptations, constitutes a psychophysiological condition characterizing voluntary breath-holding (BH). BH induces several autonomic responses, involving both autonomic cardiovascular and cutaneous pathways, whose characterization is the main aim of this study. Electrocardiogram and skin conductance (SC) recordings were collected from 14 elite divers during three conditions: free breathing (FB), normoxic phase of BH (NPBH) and hypoxic phase of BH (HPBH). Thus, we compared a set of features describing signal dynamics between the three experimental conditions: from heart rate variability (HRV) features (in time and frequency-domains and by using nonlinear methods) to rate and shape of spontaneous SC responses (SCRs). The main result of the study rises by applying a Factor Analysis to the subset of features significantly changed in the two BH phases. Indeed, the Factor Analysis allowed to uncover the structure of latent factors which modeled the autonomic response: a factor describing the autonomic balance (AB), one the information increase rate (IIR), and a latter the central nervous system driver (CNSD). The BH did not disrupt the FB factorial structure, and only few features moved among factors. Factor Analysis indicates that during BH (1) only the SC described the emotional output, (2) the sympathetic tone on heart did not change, (3) the dynamics of interbeats intervals showed an increase of long-range correlation that anticipates the HPBH, followed by a drop to a random behavior. In conclusion, data show that the autonomic control on heart rate and SC are differentially modulated during BH, which could be related to a more pronounced effect on emotional control induced by the mental training to BH
Acute Effects Of Triiodothyronine T. (T3) Replacement Therapy in Patients with Chronic Heart Failure and Low-T3 Syndrome: A Randomized, Placebo-Controlled Study
Context: Low-T3 syndrome is a predictor of poor outcome in patients with cardiac dysfunction. The
study aimed to assess the short-term effects of synthetic L-T3 replacement therapy in patients with
low-T3 syndrome and ischemic or nonischemic dilated cardiomyopathy (DC).
Design:Atotal of 20 clinically stable patients with ischemic (n12) or nonischemic (n8) DC were
enrolled. There were 10 patients (average age 72 yr, range 66–77; median, 25–75th percentile)
who underwent 3-d synthetic L-T3 infusion (study group); the other 10 patients (average age 68 yr,
range 64–71) underwent placebo infusion (control group). Clinical examination, electrocardiography,
cardiac magnetic resonance, and bio-humoral profile (free thyroid hormones, TSH, plasma
renin activity, aldosterone, noradrenaline, N-terminal-pro-B-Type natriuretic peptide, and IL-6)
were assessed at baseline and after 3-d synthetic L-T3 (initial dose: 20 g/m2 body surfaced) or
placebo infusion.
Results: After T3 administration, free T3 concentrations increased until reaching a plateau at 24–48
h (3.43, 3.20–3.84 vs. 1.74, 1.62–1.93 pg/ml; P 0.03) without side effects. Heart rate decreased
significantly after T3 infusion (63, 60–66 vs. 69, 60–76 beats per minute; P 0.008). Plasma noradrenaline
(347; 270–740 vs. 717, 413–808 pg/ml; P 0.009), N-terminal pro-B-Type natriuretic
peptide (3000, 438-4005 vs. 3940, 528-5628 pg/ml; P0.02), and aldosterone (175, 152–229 vs. 231,
154–324 pg/ml; P 0.047) significantly decreased after T3 administration. Neurohormonal profile
did not change after placebo infusion in the control group. After synthetic L-T3 administration,
left-ventricular end-diastolic volume (142, 132–161 vs. 133, 114–158 ml/m2 body surface; P 0.02)
and stroke volume (40, 34–44 vs. 35, 28–39 ml/m2 body surface; P 0.01) increased, whereas
external and intracardiac workload did not change.
Conclusions: In DC patients, short-term synthetic L-T3 replacement therapy significantly improved
neuroendocrine profile and ventricular performance. These data encourage further controlled
trials with more patients and longer periods of synthetic L-T3 administration
Association Between Increased Mortality and Mild Thyroid Dysfunction in Cardiac Patients
BACKGROUND: The effects of subclinical thyroid dysfunction on cardiac outcome are not well defined. METHODS: To assess the relationship between mild thyroid dysfunction and the incidence of death in cardiac patients, we evaluated 3121 cardiac patients. Cardiac and overall deaths were considered. Four groups were defined: euthyroidism, subclinical hypothyroidism (SCH), subclinical hyperthyroidism (SCT), and low triiodothyronine syndrome (low T3). RESULTS: After mean follow-up of 32 months, there were 65 and 140 cardiac and overall deaths (3.4% and 7.3%), respectively, in euthyroidism, 15 and 27 (7.2% and 13.0%) in SCH, 8 and 9 (8.2% and 9.2%) in SCT, and 59 and 119 (6.5% and 13.1%) in low T3. Survival rates for cardiac death were lower in SCH, SCT, and low T3 than in euthyroidism (log-rank test; chi2 = 19.46; P < .001). Survival rates for overall death were lower in SCH and low T3 than in euthyroidism (log-rank test; chi2 = 26.67; P < .001). After adjustment for several risk factors, hazard ratios (HRs) for cardiac death were higher in SCH (HR, 2.40; 95% confidence interval [CI], 1.36-4.21; P = .02), SCT (HR, 2.32; 95% CI, 1.11-4.85; P = .02), and low T(3) (HR, 1.63; 95% CI, 1.14-2.33; P = .007) than in euthyroidism; HRs for overall death were higher in SCH (HR, 2.01; 95% CI, 1.33-3.04; P < .001) and low T3 (HR, 1.57; 95% CI, 1.22-2.01; P < .001) but not in SCT. CONCLUSION: A mildly altered thyroid status is associated with an increased risk of mortality in patients with cardiac disease
Calcitization of aragonitic bryozoans in Cenozoic tropical carbonates from East Kalimantan, Indonesia
© The Author(s) 2016. Open Access. This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The file attached is the published version of the article
A wearable sensor to monitor localized sweat rate as support tool for monitoring athletes' performances
Objectives
We developed a wearable sensor for the real time measurement of sweat rate in localized areas of the human body. This sensor represents the first step in the development of a wearable sensor network capable to estimate the global sweat rate via an ad hoc algorithm. Such device would be used to monitor athletes' hydration status during training and improve their performances.
Equipment and Methods
For this study, we tested our sensor on thirteen football players during a cycling test on a cycle ergometer. The sweat rate sensor was compared to a medical device that, although measuring a different physiological process, provides discrete data based on the same working principle, i.e. the diffusion of the water vapour emitted from the skin.
Results
Our sensor has a working range up to 400 g/m2·h. The statistical analysis and the Bland-Altman plot proved that our sensor is comparable to the medical device used as gold standard. At low sweat rate, the bias is 3.4 g/m2·h with a standard deviation of 7.6 g/m2·h. At maximum sweat rates, the bias is 2.3 g/m2·h with a standard deviation 6.9 g/m2·h. The p values for the Bland-Altman plots at low and maximum sweat rate (0.1331 and 0.2477 obtained by Kolmogorov-Smirnov test, respectively) allow the hypothesis that there is a significant difference between our sweat rate sensor and the medical device to be rejected.
Conclusion
We presented a prototype of a wearable sweat rate sensor for localized measurements. The trials on thirteen athletes proved that the performance of our sensor is comparable to that of a commercial medical device. This sweat rate sensor can provide valuable information on athletes' hydration status
Cervelleite, Ag4TeS: solution and description of the crystal structure
Copyright: Springer-Verlag Wien 2015. This is the final, post refereeing version. You are advised to consult the publisher's version if you wish to cite from it, http://link.springer.com/article/10.1007%2Fs00710-015-0384-
Mortality for chronic-degenerative diseases in Tuscany: Ecological study comparing neighboring areas with substantial differences in environmental pollution
Objectives: Environmental pollution is associated with morbidity and mortality for chronic-degenerative diseases. Recent data points out a relationship between proximity to industrial plants and mortality due to neoplasms. The aim of this study has been to compare mortality due to chronic-degenerative diseases in the area of Tuscany (Bassa Val di Cecina), Italy, characterized by the presence of 2 neighboring municipalities similar in terms of size but with substantial differences in industrial activities: Rosignano (the site of chemical, energy production and waste processing industries) and Cecina (with no polluting activity). Material and Methods: Standardized mortality rates for the 2001–2010 decade were calculated; the data of the whole Tuscany was assumed as reference. Environmental levels of pollutants were obtained by databases of the Environmental Protection Agency of Tuscany Region (Agenzia Regionale per la Protezione Ambientale della Toscana – ARPAT). Maximum tolerated pollutant levels set by national laws were assumed as reference. Results: In the whole Bassa Val di Cecina, significantly elevated standardized mortality rates due to mesothelioma, ischemic heart diseases, cerebrovascular diseases and Alzheimer and other degenerative diseases of nervous system were observed. In the municipality of Rosignano, a significant excess of mortality for all these groups of diseases was confirmed. On the contrary, the municipality of Cecina showed only significantly higher mortality rates for ischemic heart diseases. Elevated levels of heavy metals in sea water and of particulate matter which contains particles of diameter ≤ 10 mm (PM10) and ozone in air were detected in Rosignano. Conclusions: This study shows an excess of mortality for chronic-degenerative diseases in the area with elevated concentration of polluting factories. Proximity to industrial plants seems to represent a risk factor for those diseases. Int J Occup Med Environ Health 2017;30(4):641–65
Authors' response (August 21, 2017) to the letter to the Editor concerning the paper "Mortality for chronic-degenerative diseases in Tuscany: Ecological study comparing neighboring areas with substantial difference in environmental pollution"
Critical finger ischemia and myocardial fibrosis development after sudden interruption of sildenafil treatment in a systemic sclerosis patient.
Systemic sclerosis (SSc) is a connective tissue disease frequently associated with Raynaud’s Phenomenon (RP). Among possible pharmacological treatments, phosphodiesterase 5 inhibitors are considered in cases of severe non -responsive RP. We present the case of a male SSc patient wh presented with critical finger ischemia and concomitant appearance of myocardial fibrosis after sudden interruption of sildenafil treatment
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