Plastics are mixtures of organic polymers that play a major role in environmental contamination worldwide. One way to reduce the waste arising from the use of plastics, especially disposable ones, can be to produce environmentally friendly cutlery. The aim of the work was the production of biodegradable spoons and evaluation of their texture, antioxidant activities and total polyphenols content. The spoons were made from a combination of the following ingredients: water, grape, proso millet, wheat, xanthan and palm oil in different concentrations. The samples were baked at 180 or 240 °C, some spoons were dried in a fruit dehydrator. According to the results of the analysis, a spoon prepared from a mixture of all three flours and with the addition of xanthan appears to be the most suitable replacement for plastic cutlery. This spoon showed high strength and antioxidant activity. It was confirmed that the use of grape flour has a beneficial effect on the nutritional profile of the experimentally produced biodegradable spoons.
The cross-spectral analysis of heart rate (HR) and blood pressure (BP) variabilities provides "amplitude" and "phase" related measures. Compared to the amplitude measure, that is the baroreflex gain, the phase related measure characterizing the time lag between HR and BP oscillations has been studied to a much lesser extent. A population of 103 patients (73 men, 30 women, aged 53 +/- 12, range 20-82 years) referred for the management of coronary artery disease and/or hypertension were studied. In each subject, electrocardiogram and BP recordings were obtained in the supine and sitting positions of 5 minutes of rest (spontaneous respiration), 3 minutes of controlled respiration at 0.1 Hz (slow-controlled respiration), and 3 minutes of controlled respiration at 0.33 Hz (fast-controlled respiration). The frequency of maximum coherence (above the arbitrary threshold of 0.5) of BP and RR interval variabilities was searched between 0.033-0.133 Hz and 0.200-0.400 Hz to obtain baroreflex gain and phase shift in low and high frequency bands, respectively. Mean phase shifts of -79.1 and -67.0 degrees (-2.4 and -2.1 s) were found during slow-controlled respiration in the supine and sitting body positions, respectively. The mean phase shift between systolic BP and RR interval in the low frequency band was found between 83 and -109 degrees for body positions and respiration regimes. The actual baroreflex related time lag between systolic BP and RR variations was found between 3.5 and 5.1 seconds. The study concludes that the appropriate, and not always easy, selection of the frequency of maximum coherence between BP and HR oscillation is crucial for an accurate cross-spectral assessment of baroreflex sensitivity.
Aims The standard deviation of activation time (SDAT) derived from body surface maps (BSMs) has been proposed as an optimal measure of electrical dyssynchrony in patients with cardiac resynchronization therapy (CRT). The goal of this study was two-fold: (i) to compare the values of SDAT in individual CRT patients with reconstructed myocardial metrics of depolarization heterogeneity using an inverse solution algorithm and (ii) to compare SDAT calculated from 96-lead BSM with a clinically easily applicable 12-lead electrocardiogram (ECG). Methods and results Cardiac resynchronization therapy patients with sinus rhythm and left bundle branch block at baseline (n = 19, 58% males, age 60 ± 11 years, New York Heart Association Classes II and III, QRS 167 ± 16) were studied using a 96-lead BSM. The activation time (AT) was automatically detected for each ECG lead, and SDAT was calculated using either 96 leads or standard 12 leads. Standard deviation of activation time was assessed in sinus rhythm and during six different pacing modes, including atrial pacing, sequential left or right ventricular, and biventricular pacing. Changes in SDAT calculated both from BSM and from 12-lead ECG corresponded to changes in reconstructed myocardial ATs. A high degree of reliability was found between SDAT values obtained from 12-lead ECG and BSM for different pacing modes, and the intraclass correlation coefficient varied between 0.78 and 0.96 (P < 0.001). Conclusion Standard deviation of activation time measurement from BSM correlated with reconstructed myocardial ATs, supporting its utility in the assessment of electrical dyssynchrony in CRT. Importantly, 12-lead ECG provided similar information as BSM. Further prospective studies are necessary to verify the clinical utility of SDAT from 12-lead ECG in larger patient cohorts, including those with ischaemic cardiomyopathy.
Funding Acknowledgements Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Supported by the research grant of the AZV (Ministry of Health of the Czech Republic) Background Biventricular pacing (BVP) using multiple left ventricular (LV) sites may augment the hemodynamic effect of cardiac resynchronisation therapy (CRT) by engaging a greater mass of the myocardium. Purpose To evaluate the acute hemodynamic effect of a novel multi-site, multi-point BVP configuration. Methods The study investigated 18 patients with idiopathic dilated cardiomyopathy and left bundle-branch block during implantation of a BVP device (age: 59 ± 14 years, female gender: 7 [39%], LVEF: 27 ± 6%, native QRS: 171 ± 16 ms). Conventional leads were placed in the right atrium (RA) and ventricle (RV), one quadripolar LV lead (Quartet, Abbott, Abbott Park, IL, USA) was positioned in the posterolateral and another one in lateral or anterolateral coronary vein. Individual bipoles of all leads were connected through a splitter to separate external cardiac stimulators. Hemodynamics was evaluated using a micromanometer-tipped catheter (Micro-Cath, Millar, Tx, USA) located in the LV during RA pacing above sinus rate and five atrio-ventricular sequential pacing configurations at the same rate: 1.) RA+RV, 2.) RA + RV + distal bipole of the LV lead with greater dP/dT („conventional BVP"), 3.) RA + RV + distal and proximal bipoles of the LV lead with greater dP/dT („single-lead multi-point BVP"), 4.) RA + RV + distal bipoles of both LV leads („two-lead multi-site BVP"), and 5.) sequentional pacing RA + RV + all bipoles of both LV leads interconnected to a mesh („maximum BVP"). Results Compared to RA pacing, LV dP/dT was significantly greater during all BVP pacing configurations (RA pacing: 1940 ± 507 mmHg/s vs. conventional BVP: 2431 ± 855 mmHg/s, single-lead multi-point BVP: 2539 ± 740 mmHg/s, two-lead multisite BVP: 2517 ± 836 mmHg/s, and "maximum BVP": 2685 ± 893 mmHg/s, all p<0.001, Figure 1), but not during RA-RV pacing (2014 ± 721 mmHg/s, p=0.12). In addition, dP/dT was significantly greater during "maximum BVP" compared to conventional BVP (p=0.05). Conclusion Compared to RA pacing and conventional BVP, the greatest increase in LV contractility was achieved with a novel multi-site, multi-point "maximum BVP" configuration. These preliminary findings provide a rationale for designing new approaches to CRT.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.