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The objective of this study was to better understand the effect of micro/nanofibrils added as reinforcement on paper handsheets, their physical-mechanical performance and barrier properties, and to...

The objective of the present work was to evaluate the use of Raman microspectroscopy analysis to assess changes in cellulose micro/nanofibril structure from fibers subjected to different pre-treatments. Pulp fibers were pre-treated with 5 wt% NaOH for 2 h, 10 wt% NaOH for 1 h, and endoglucanase-type enzymes to improve nanofibrilation. After the pre-treatments, the fibers were mechanically fibrillated to produce cellulose micro/nanofibrils, which were made into films to be analyzed. Fibers pre-treated with 5 wt% NaOH produced 59% micro/nanofibrils with average diameter less than 30 nm, for Eucalyptus, and 46% of micro/nanofibrils, with the same diameter, for Pinus. However, the enzymatic pre-treatment was the most efficient, resulting in 83% of micro/nanofibrils for Eucalyptus and 78% for Pinus. This corroborates with the lowest values of the 1.096/2.896 ratio and degree of polymerization, indicating chain shortening in cellulose. X-ray diffraction and Raman microspectroscopy crystallinity results presented similar tendencies, with increased crystallinity caused by all pre-treatments, being 5 wt% NaOH for 2 h the highest, with 70%, for Eucalyptus and Pinus. Enzymatic pre-treatment has produced the best fibrillation and greater crystallinity. The present work has shown a reliable way of assessing cellulose structure using Raman microspectroscopy.

Obstructive sleep apnea (OSA) is one of the most common sleep disorders and affects nearly a billion people worldwide. Furthermore, it is estimated that many patients with OSA are underdiagnosed, which contributes to the development of comorbidities, such as cardiac autonomic imbalance, leading to high cardiac risk. Heart rate variability (HRV) is a non-invasive, widely used approach to evaluating neural control of the heart. This study evaluates the relationship between HRV indices and the presence and severity of OSA. We hypothesize that HRV, especially the nonlinear methods, can serve as an easy-to-collect marker for OSA early risk stratification. Polysomnography (PSG) exams of 157 patients were classified into four groups: OSA-free (N = 26), OSA-mild (N = 39), OSA-moderate (N = 37), and OSA-severe (N = 55). The electrocardiogram was extracted from the PSG recordings, and a 15-min beat-by-beat series of RR intervals were generated every hour during the first 6 h of sleep. Linear and nonlinear HRV approaches were employed to calculate 32 indices of HRV. Specifically, time- and frequency-domain, symbolic analysis, entropy measures, heart rate fragmentation, acceleration and deceleration capacities, asymmetry measures, and fractal analysis. Results with indices of sympathovagal balance provided support to reinforce previous knowledge that patients with OSA have sympathetic overactivity. Nonlinear indices showed that HRV dynamics of patients with OSA display a loss of physiologic complexity that could contribute to their higher risk of development of cardiovascular disease. Moreover, many HRV indices were found to be linked with clinical scores of PSG. Therefore, a complete set of HRV indices, especially the ones obtained by the nonlinear approaches, can bring valuable information about the presence and severity of OSA, suggesting that HRV can be helpful for in a quick diagnosis of OSA, and supporting early interventions that could potentially reduce the development of comorbidities.

In this study, the characteristics of jute fibers and cellulose nanofibrils (CNFs) and their impacts on mechanical strength were compared, particularly from the standpoint of their application as reinforcement in extruded fiber–cement composites. Raw jute fibers were subjected to an alkaline treatment before being fibrillated into CNFs. The fiber–cement composites were produced with jute fibers (0.5% and 2%) and CNFs (0.5% and 2%) via extrusion process. Both percentages of reinforcement were based on the cement mass. In addition, hybrid composites with a mixture of fibers and CNFs were produced. Hydroxypropyl methylcellulose and carboxylic polyether were used as additives to improve the mixture’s rheology. The composites were subjected to natural weathering for 5 months before being analyzed for their physical and mechanical properties. CNFs and jute fibers subjected to NaOH treatment presented a higher initial degradation temperature (Tonset). The apparent porosity decreased for all compositions studied, reaching a 75% reduction for the sample reinforced with 2% CNFs. Fiber–cement with a hybrid reinforcement of 1.5% CNFs + 0.5% fibers exhibited the strongest mechanical performance. All compositions showed a decrease in the modulus of elasticity after natural weathering. In contrast, the modulus of rupture and the limit of proportionality showed an average gain of 1 MPa for fiber–cement composites produced with hybrid reinforcements. The better mechanical performance of the hybrid formulations may be owing to the synergistic work of the fibers and CNFs, suggesting the potential of cellulose CNFs for use as reinforcement in cement-based composites.

We evaluated the effects of long-term (48 h) electrical stimulation of the carotid sinus (CS) in hypertensive rats. L-NAME-treated (10 days) Wistar rats were implanted with a catheter in the femoral artery and a miniaturized electrical stimulator attached to electrodes positioned around the left CS, encompassing the CS nerve. One day after implantation, arterial pressure (AP) was directly recorded in conscious animals for 60 min. Square pulses (1 ms, 3 V, 30 Hz) were applied intermittently (20/20 s ON/OFF) to the CS for 48 h. After the end of stimulation, AP was recorded again. Nonstimulated rats (control group) and rats without electrodes around the CS (sham-operated) were also studied. Next, the animals were decapitated, and segments of mesenteric resistance arteries were removed to study vascular function. After the stimulation period, AP was 16 ± 5 mmHg lower in the stimulated group, whereas sham-operated and control rats showed similar AP between the first and second recording periods. Heart rate variability (HRV) evaluated using time and frequency domain tools and a nonlinear approach (symbolic analysis) suggested that hypertensive rats with electrodes around the CS, stimulated or not, exhibited a shift in cardiac sympathovagal balance towards parasympathetic tone. The relaxation response to acetylcholine in endothelium-intact mesenteric arteries was enhanced in rats that underwent CS stimulation for 48 h. In conclusion, long-term CS stimulation is effective in reducing AP levels, improving HRV and increasing mesenteric vascular relaxation in L-NAME hypertensive rats. Moreover, only the presence of electrodes around the CS is effective in eliciting changes in HRV similar to those observed in stimulated rats.

To evaluate the heart rate fragmentation (HRF) of type 2 diabetes mellitus (T2DM) patients and its relationship with heart rate variability (HRV) indices.One hundred sixty-four men, aged 47-57 years were retrospectively analyzed from a database. Participants were T2DM (n=82) and apparently healthy (n=82). R-R interval time series recorded by electrocardiogram were collected at the supine position for 10 to 15 minutes. From HRF, the percentage of inflection points (PIP), percentage of words with zero, one, two, or three inflections points (WT2DM presented higher PIP, WT2DM have increased fragmentation patterns, and words grouped by inflection type are more closely related to HRV. The HRF approach might be useful to assess heart rate dynamic abnormalities in males with type 2 diabetes.

Introduction The pathogenesis of Chronic Chagas Cardiomyopathy (CCC) is not yet fully elucidated. However, dysautonomia is one of the factors involved, in addition to being the essential mechanism in the pathogenesis of the Digestive Form of Chagas Disease (DFCD). The prognostic value of dysautonomia remains speculative, and there are no correlative studies of dysautonomia in CCC and DFCD. Purpose This study has three aims: a) to investigate in patients with CCC the relationship between cardiac dysautonomia, indirectly studied by heart rate variability (HRV), and the prognostic stratification assessed by the Rassi score; b) to compare the HRV in groups with isolated CCC and with the mixed form, i.e. CCC associated with DFCD; c) to evaluate the power of combining HRV indices to predict the risk class of each patient, using machine learning. Methods Thirty-one patients with CCC were classified into three risk groups (low, intermediate and high) according to their Rassi score and had two electrocardiograms (ECG) recorded, i.e. the conventional 12-lead and a single lead, the latter for a period of 10 to 20 minutes. From the single lead ECG, two equally sized RR series were generated and 31 HRV indices were calculated from each. The HRV was then compared between the three risk groups and also regarding the presence or not of concomitant digestive impairment. Taking HRV indices as inputs, four machine learning models were compared in its ability to predict the risk class of each patient. A previous step of attribute selection (sequential feature selection) was applied to identify the most relevant HRV indices for each algorithm. Results Comparing the HRV indices in the three risk groups obtained with the Rassi score, the phase entropy is decreased [0.91 (0.90, 0.91) vs 0.87 (0.86, 0.89); p=0.039] and the percentage of inflection points is increased [66.4 (63.5, 71.2) vs 58.2 (53.4, 63.3); p=0.032] in patients in the high-risk group, compared to the low-risk group. Of the 31 patients with CCC, 14 had the mixed form of the disease, i.e. with associated digestive impairment. In the latter, the triangular interpolation of the RR interval histogram decreased significantly [78.1 (62.5, 101.6) vs 121.1 (80.1, 146.5), p=0.046], while the absolute power in the low-frequency band decreased with strong trend to statistical significance [28.5 (17.1, 97.5) vs 86.9 (44.1, 171.7), p=0.06]. The best predictive model for each risk group was obtained with the Support Vector Machine, reaching an overall F1-score of 0.61. Conclusions The worst prognosis, indicated by the Rassi score, is associated with increased heart rate fragmentation. The combination of HRV indices enhanced the accuracy of the risk stratification. Compared to CCC the mixed form of Chagas' disease displays a decrease in the components of slow heart rate oscillation, suggesting a higher degree of sympathetic autonomic denervation associated with parasympathetic impairment. Funding Acknowledgement Type of funding sources: Foundation. Main funding source(s): São Paulo Research Foundation (FAPESP)

OBJECTIVE: To assess the possible factors that influence sleep quality in adolescents with and without chronic immunosuppressive conditions quarantined during the coronavirus disease 2019 (COVID-19) pandemic. METHODS: This cross-sectional study included 305 adolescents with chronic immunocompromised conditions and 82 healthy adolescents. Online surveys were completed, which included questions on socio-demographic data and self-rated healthcare routine during COVID-19 quarantine and the following validated questionnaires: the Pittsburgh Sleep Quality Index (PSQI), Pediatric Quality of Life Inventory 4.0 (PedsQL4.0), and Pediatric Outcome Data Collection Instrument (PODCI). RESULTS: The median current age [14 (10-18) vs. 15 (10-18) years, p=0.847] and frequency of female sex (62% vs. 58%, p=0.571) were similar in adolescents with chronic conditions compared with healthy adolescents. The frequency of poor sleep quality was similar in both groups (38% vs. 48%, p=0.118). Logistic regression analysis, including both healthy adolescents and adolescents with chronic conditions (n=387), demonstrated that self-reported increase in screen time (odds ratio [OR] 3.0; 95% confidence interval [CI] 1.3-6.8; p=0.008) and intrafamilial violence report (OR 2.1; 95% CI 1.2-3.5; p=0.008) were independently associated with poor sleep quality in these adolescents. However, the PODCI global function score was associated with a lower OR for poor sleep quality (OR 0.97; 95% CI 0.94-0.99; p=0.001). Further logistic regression, including only adolescents with chronic conditions (n=305), demonstrated that self-reported increase in screen time (OR 3.1; 95% CI 1.4-6.8; p=0.006) and intrafamilial violence report (OR 2.0; 95% CI 1.2-3.4; p=0.011) remained independently associated with poor quality of sleep, whereas a lower PODCI global function score was associated with a lower OR for sleep quality (OR 0.96; 95% CI 0.94-0.98; p

Two-dimensional sample entropy (SampEn2D) is a recently developed method in the field of information theory for evaluating the regularity or predictability of images. SampEn2D, though powerful, has two key limitations: (1) SampEn2D values are undefined for small-sized images; and (2) SampEn2D is computationally expensive for several real-world applications. To overcome these drawbacks, we introduce the two-dimensional dispersion entropy (DispEn2D) measure. To evaluate the ability of DispEn2D, in comparison with SampEn2D, we use various synthetic and real datasets. The results demonstrate that DispEn2D distinguishes different amounts of white Gaussian and salt and pepper noise. The periodic images, compared with their corresponding synthesized ones, have lower DispEn2D values. The results for Kylberg texture dataset show the ability of DispEn2D to differentiate various textures. Although the results based on DispEn2D and SampEn2D for both the synthetic and real datasets are consistent in that they lead to similar findings about the irregularity of images, DispEn2D has three main advantages over SampEn2D: (1) DispEn2D, unlike SampEn2D, does not lead to undefined values; (2) DispEn2D is noticeably quicker; and (3) The coefficient of variations and Mann–Whitney U test-based p-values for DispEn2D are considerably smaller, showing the more stability of the DispEn2D results. Overall, thanks to its successful performance and low computational time, DispEn2D opens up a new way to analyze the uncertainty of images.

Background Lipopolysaccharide (LPS)-induced systemic inflammation (SI) is associated with neuroinflammation in the brain, hypotension, tachycardia, and multiple organs dysfunctions. Considering that during SI these important cardiovascular and inflammatory changes take place, we measured the sensitivity of the cardiovascular reflexes baroreflex, chemoreflex, and Bezold-Jarisch that are key regulators of hemodynamic function. We also evaluated neuroinflammation in the nucleus tractus solitarius (NTS), the first synaptic station that integrates peripheral signals arising from the cardiovascular and inflammatory status. Methods We combined cardiovascular recordings, immunofluorescence, and assays of inflammatory markers in male Wistar rats that receive iv administration of LPS (1.5 or 2.5 mg kg−1) to investigate putative interactions of the neuroinflammation in the NTS and in the anteroventral preoptic region of the hypothalamus (AVPO) with the short-term regulation of blood pressure and heart rate. Results LPS induced hypotension, tachycardia, autonomic disbalance, hypothermia followed by fever, and reduction in spontaneous baroreflex gain. On the other hand, during SI, the bradycardic component of Bezold-Jarisch and chemoreflex activation was increased. These changes were associated with a higher number of activated microglia and interleukin (IL)-1β levels in the NTS. Conclusions The present data are consistent with the notion that during SI and neuroinflammation in the NTS, rats have a reduced baroreflex gain, combined with an enhancement of the bradycardic component of Bezold-Jarisch and chemoreflex despite the important cardiovascular impairments (hypotension and tachycardia). These changes in the cardiac component of Bezold-Jarisch and chemoreflex may be beneficial during SI and indicate that the improvement of theses reflexes responsiveness though specific nerve stimulations may be useful in the management of sepsis.

Over the last few years, there has been a great interest in the production of cellulose nanofiber films. However, conventional casting and film with only one kind of nanofiber may give rise to brittle material. Furthermore, films formed by the mixture of cellulose nanocrystal (CNC) and cellulose nanofibril (CNF) by continuous casting have not been reported. In this way, this study aims to investigate the optical, thermal, mechanical, and physical properties of the mixture of CNC and CNF films obtained by continuous casting from curaua and eucalyptus fibers at the proportions of 0/100, 25/75, 50/50, 75/25, and 100/0 (% w/w). After continuous casting, neat CNC and neat CNF are cleared oriented, causing anisotropic mechanical properties. On the other hand, the mixture of CNC and CNF made the films mechanically more isotropic, even though some degree of orientation of the fibers. The films with a mixture of CNC/CNF 25/75 (% w/w) were more thermally stable. The addition of CNC in CNF films decreased their opacity. Thus, the type of nanofibers, the cellulose source, the process, and the mixture of CNC/CNF affect the properties of the films significantly. CNC/CNF blend films obtained by continuous casting.

Multiscale entropy (MSE) analysis is a fundamental approach to access the complexity of a time series by estimating its information creation over a range of temporal scales. However, MSE may not be accurate or valid for short time series. This is why previous studies applied different kinds of algorithm derivations to short-term time series. However, no study has systematically analyzed and compared their reliabilities. This study compares the MSE algorithm variations adapted to short time series on both human and rat heart rate variability (HRV) time series. The most used variations of MSE are studied: composite MSE (CMSE), refined composite MSE (RCMSE), modified MSE (MMSE), and their fuzzy versions. We also analyze the errors in MSE estimations for a range of incorporated fuzzy exponents. The results show that fuzzy MSE versions-as a function of time series length-present minimal errors compared to the non-fuzzy algorithms. The traditional multiscale entropy algorithm with fuzzy counting (MFE) has similar accuracy to alternative algorithms with better computing performance. For the best accuracy, the findings suggest different fuzzy exponents according to the time series length.

While the US nut industry is growing, markets for nut by-products, particularly nutshells and tree prunings, have not kept pace. Torrefaction is a thermochemical process used to improve physicochemical properties of biomass for energy and other applications. The goal of the paper was to characterize the effects of a range of torrefaction conditions on the properties of nut by-product feedstock. The process consists of thermal treatment of biomass at a temperature between 200 and 300°C in the absence of oxygen, where final material properties of the torrefied biomass depend on the temperature, heating rate, and residence time. In general, torrefied biomass exhibits higher hydrophobicity and calorific value with reduced moisture absorption compared to untreated biomass, making it an ideal fuel source for energy applications compared to raw biomass. In this study, almond shells of soft, semi-soft, and hardshell varieties, as well as walnut shells and almond wood, were torrefied at two different temperatures (230 and 290°C) and three different residence times (20, 40, and 60 min) in order to characterize the physicochemical properties. The thermal behavior of raw and heat-treated biomass was investigated by TGA analysis, elemental analysis, pH, helium pycnometry, FTIR spectroscopy, and dynamic vapor sorption analysis.

Background: The objective of the present work was to investigate the influence of a pre-treatment of microbial-rich digestate (liquid mesophilic anaerobic digestate - AD-supernatant) on the morphology, crystallinity, and thermal stability of cellulose pulp fiber. Results: The six most abundant bacteria in the AD-supernatant were determined by 16S analysis. The bacteria population was comprised mostly of Bacteroides graminisolvens (66%) and Parabacteroides chartae (28%). Enzymatic activity from the bacteria partially removed the amorphous components and increased the crystallinity and crystallite size of the cellulose substrate. The fiber pulp was incubated in AD-supernatant for 5, 10, and 20 days. The X-ray diffraction data provided evidence that the amorphous portion of the cellulose was more readily and quickly hydrolyzed than the crystalline portion. The longest incubation times (20 days) resulted in substantial deconstruction of the cellulose fiber structure and decreased the thermal degradation temperature. Conclusion: The anaerobic digestate is inexpensive and could be used to effectively aid in the pre-treatment of cellulose on large scale transformation processes, e.g. for making biofuels, cellulose micro/nanofiber production or engineered fiber-based materials.

International audience; Multiscale entropy (MSE) analysis is a fundamental approach to access the complexity of a time series by estimating its information creation over a range of temporal scales. However, MSE may not be accurate or valid for short time series. This is why previous studies applied different kinds of algorithm derivations to short-term time series. However, no study has systematically analyzed and compared their reliabilities. This study compares the MSE algorithm variations adapted to short time series on both human and rat heart rate variability (HRV) time series using long-term MSE as reference. The most used variations of MSE are studied: composite MSE (CMSE), refined composite MSE (RCMSE), modified MSE (MMSE), and their fuzzy versions. We also analyze the errors in MSE estimations for a range of incorporated fuzzy exponents. The results show that fuzzy MSE versions—as a function of time series length—present minimal errors compared to the non-fuzzy algorithms. The traditional multiscale entropy algorithm with fuzzy counting (MFE) has similar accuracy to alternative algorithms with better computing performance. For the best accuracy, the findings suggest different fuzzy exponents according to the time series length.

Objective Investigate whether heart rate variability (HRV) indices can be used to predict morpho-functional parameters obtained from the echocardiogram in a population of patients with Chagas disease (CD). Methods Sixty-three patients with CD and a recent echocardiogram had their ECG and respiratory signals recorded for 15 min. The cardiac interval series were generated from the ECG and 27 HRV indices, plus the respiratory frequency, were calculated. The correlation between HRV and echocardiographic variables was estimated. The HRV indices were also utilized as inputs in four machine learning schemes to create predictive models for numeric and categorical echocardiographic parameters. Attribute selection schemes were also performed to identify the subset of HRV indices that best represent each parameter for each machine learning algorithm. Results Only three echocardiographic parameters had no HRV index significantly correlated to them. The most frequently selected HRV index in the attribute selection process was the fractal short-term scaling exponent. The regression models (numeric parameters) reached reasonable performance (R > 0.5) for all except two parameters, while the classification models (categorical variables) achieved better performance, with precision and recall values higher than 0.74. Conclusion HRV indices, both isolated and combined, are associated with cardiac morpho-functional properties in patients with CD, and may be used to predict echocardiographic parameters. Significance The possibility of modeling the cardiac morpho-functional parameters in patients with CD using HRV indices opens the possibility to use HRV for risk assessment in patients with CD, especially those harboring the indeterminate form of the disease.

Although rapid oscillations in heart rate (HR) are commonly attributed to vagal modulation of the heart, an ultra-rapid pattern of HR variation has recently been studied and named heart rate fragmentation (HRF). Objective Considering that the underlying mechanisms of HRF are unknown, this study aims to evaluate the influence of the autonomic nervous system on HRF in rats. Methods Electrocardiogram recordings were performed in awake rats at baseline conditions and after selective or combined pharmacological autonomic blockade. Series of RR intervals were calculated and HRF indices were computed, namely percentage of inflection points (PIP), percentage of patterns with zero (W0), one (W1), two (W2) or three (W3) inflection points, and percentage of patterns with only hard (WH), soft (WS) or mixed (WM) inflection points. Moreover, the correlations between HRF indices and several important heart rate variability (HRV) indices were estimated. Results PIP and W3 increased while W1 decreased after autonomic blockade (sympathetic, parasympathetic or combined). In contrast, the parasympathetic blockade noticeably decreased hard (WH) and increased soft (WS) HR transitions. Except for W0, HRF patterns grouped by the number of inflection points were not correlated to any studied HRV index. In contrast, patterns grouped by the type of inflection points are highly correlated to magnitude-dependent HRV indices. Conclusion Cardiac sympathetic and parasympathetic influences similarly decrease HRF, while the parasympathetic control markedly increases the hard HR inflection points. Further studies should be conducted to verify whether the autonomic nervous system plays a different role in diseases marked by autonomic imbalance.

Monitoring of markers reflecting cardiac autonomic activity before and during stressful situations may be useful for identifying the physiological state of an athlete and may have medical or performance implications. The study aimed to determine group and individual changes in short-term (5 min) and ultra-short-term (1 min) heart rate (HR), respiratory rate (RespRate), and time-domain heart rate variability (HRV) parameters during sympathetic nervous system activity (SNSa) stimulation among professional endurance athletes. Electrocardiographic recordings were performed in stable measurement conditions (Baseline) and during SNSa stimulation via isometric handgrip in 12 elite modern pentathlonists. Significant increases in short-term HR and decreases in time-domain HRV parameters with no changes in RespRate were observed during SNSa stimulation. Significant differences were observed between Baseline (all minutes) and the last (i.e., 5th) minute of SNSa stimulation for ultra-short-term parameters. Analysis of intra-individual changes revealed some heterogeneity in responses. The study provides baseline responses of HR, RespRate, and time-domain HRV parameters to SNSa stimulation among elite pentathlonists, which may be useful for identifying abnormal responses among fatigued or injured (e.g., concussed) athletes. More attention to individual analysis seems to be necessary when assessing physiological responses to sympathetic stimuli in professional endurance athletes.

Research on reliability of heart rate variability (HRV) parameters in athletes has received increasing attention. The aims of this study were to examine the inter-day reliability of short-term (5 min) and ultra-short-term (1 min) heart rate (HR), respiratory rate (RespRate) and HRV parameters, agreement between short-term and ultra-short-term parameters, and association between differences in HR, RespRate and HRV parameters in elite modern pentathletes. Electrocardiographic recordings were performed in stable measurement conditions with a week interval between tests. Relative reliability was evaluated by intra-class correlation coefficients, absolute reliability was evaluated by within-subject coefficient of variation, and agreement was evaluated using Bland–Altman (BA) plot with limits of agreement and defined a priori maximum acceptable difference. Short-term HR, RespRate, log transformed (ln) root mean square of successive normal-to-normal interval differences (lnRMSSD), ln high frequency (lnHF) and SD2/SD1 HRV indices and ultra-short-term HR, RespRate and lnRMSSD presented acceptable, satisfactory inter-day reliability. Although there were no significant differences between short-term and ultra-short-term HR, RespRate and lnRMSSD, no parameter showed acceptable differences with BA plots. Differences in time-domain and non-linear HRV parameters were more correlated with differences in HR than with differences in RespRate. Inverse results were observed for frequency-domain parameters. Short-term HR, RespRate, lnRMSSD, lnHF, and SD2/SD1 and ultra-short-term HR, RespRate and lnRMSSD could be used as reliable parameters in endurance athletes. However, practitioners should interpret changes in HRV parameters with regard to concomitant differences in HR and RespRate and caution should be taken before considering 5 min and 1 min parameters as interchangeable.

Beyond the regulation of cardiovascular function, baroreceptor afferents play polymodal roles in health and disease. Sepsis is a life-threatening condition characterized by systemic inflammation (SI) and hemodynamic dysfunction. We hypothesized that baroreceptor denervation worsens lipopolysaccharide (LPS) induced-hemodynamic collapse and SI in conscious rats. We combined: (a) hemodynamic and thermoregulatory recordings after LPS administration at a septic-like non-lethal dose (b) analysis of the cardiovascular complexity, (c) evaluation of vascular function in mesenteric resistance vessels, and (d) measurements of inflammatory cytokines (plasma and spleen). LPS-induced drop in blood pressure was higher in sino-aortic denervated (SAD) rats. LPS-induced hemodynamic collapse was associated with SAD-dependent autonomic disbalance. LPS-induced vascular dysfunction was not affected by SAD. Surprisingly, SAD blunted LPS-induced surges of plasma and spleen cytokines. These data indicate that baroreceptor afferents are key to alleviate LPS-induced hemodynamic collapse, affecting the autonomic control of cardiovascular function, without affecting resistance blood vessels. Moreover, baroreflex modulation of the LPS-induced SI and hemodynamic collapse are not dependent of each other given that baroreceptor denervation worsened hypotension and reduced SI.

Chagas disease (CD) is caused by the protozoan Trypanosoma cruzi and chronic cardiomyopathy (CC) is its most frequent and ominous consequence. The risk of death of patients with CD has been related to demographic, electrocardiographic-radiological-ultrasonographic and Holter parameters. Cardiac dysautonomia has also been demonstrated and may contribute to the pathogenesis of CC. We hypothesize that heart rate variability (HRV) indices are related to cardiac dysfunction as evaluated with echocardiography, and may configure a noninvasive prognostic marker in patients with CD. Short-term (15 min) cardiac interval series of 23 patients with CD were analyzed using 15 HRV indices and correlated to 7 morpho-functional echocardiographic parameters. Results showed that echocardiographic parameters are correlated with HRV indices, and that distribution entropy seems to be an important index for noninvasive prognostication of CD.

Symbolic dynamics is one of the most relevant heart rate variability approaches to evaluate sympatho-vagal cardiac modulation in health and disease. Distinct symbolization methods have been developed recently to overcome the influence of spurious extreme values, often present in time series of RR intervals. We evaluated the influence of the length of the RR series of rats in basal condition on three distinct symbolization methods, namely sigma, man-mix, and equal probability approaches. Sigma was the only symbolization strategy where the length of the series used did not affect the results. The symbolization results based on the max-min and equal probability approaches returned different results according to the size of the series used. Moreover, results also showed differences in the distribution percentage of symbolic indices according to the symbolization approach applied.

Cardiac autonomic dysfunction has been reported in patients with cerebral palsy (CP). The aim of this study was to assess the existing literature on heart rate variability (HRV) in pediatric patients with CP and a special attention was paid to the compliance of the studies with the current HRV assessment and interpretation guidelines. A systematic review was performed in PubMed, Web of Science, and Cumulative Index to Nursing and Allied Health Literature (CINAHL) databases searched for English language publications from 1996 to 2019 using Medical Subject Headings (MeSH) terms “heart rate variability” and “cerebral palsy” in conjunction with additional inclusion criteria: studies limited to humans in the age range of 0–18 years and empirical investigations. Out of 47 studies, 12 were included in the review. Pediatric patients with CP presented a significantly higher resting heart rate and reduced HRV, different autonomic responses to movement stimuli compared to children with normal development, but also reduced HRV parameters in the children dependent on adult assistance for mobility compared to those generally independent. None of the included studies contained the necessary details concerning RR intervals acquisition and HRV measurements as recommended by the guidelines. Authors of HRV studies should follow the methodological guidelines and recommendations on HRV measurement, because such an approach may allow a direct comparison of their results.

In microscopy, morphological characteristic of the axon are the most common features assessed in histological images of nerves. Although morphometric indexes are widely used to describe histological data, the calculation of those indexes is a highly time-consuming task that demands great manual effort from the specialist. Recently, two-dimensional sample entropy (SampEn2D) was proposed to quantify the degree of irregularity present in an image, based on the spatial patterns of pixels. Here, we propose the use of SampEn2D as a suitable metric for classifying diabetic status of rats from histological images of the phrenic nerve. Microscopy images of three different Wistar rats groups (untreated diabetic (N = 24), insulin-treated diabetic (N = 9), and non-diabetic control (N = 11)) were analysed. The results show that for the optimal SampEn2D parameters (m = 1, r = 0.1), control rats have significantly (p

A wide variety of new green materials such as curaua leaf fibers (CLFs) has potential applications in nanotechnology. This study aims to investigate the thermomechanical properties and morphological structure of cellulose nanocrystals (CNCs) and cellulose nanofibrils (CNFs) films obtained by continuous casting. The CNCs were obtained by acid hydrolysis and CNFs by mechanical shearing from bleached CLFs and eucalyptus pulp. The morphology after continuous casting resulted in oriented nanofibers, and as a consequence there was mechanical anisotropy. CNCs films showed the greatest values of tensile strength (36 ± 4 MPa) and the more effective fibrillation provided better mechanical strength of eucalyptus CNFs films than curaua CNFs films. Sulfur groups and mechanical shear degradation affected the stability of CNCs and CNFs films, respectively. Thus, the type of nanostructure, the way they interact to each other, the cellulose source and the process interfere significantly on the properties of the films.

Heart rate variability (HRV) has been extensively explored by traditional linear approaches (e.g., spectral analysis); however, several studies have pointed to the presence of nonlinear features in HRV, suggesting that linear tools might fail to account for the complexity of the HRV dynamics. Even though the prevalent notion is that HRV is nonlinear, the actual presence of nonlinear features is rarely verified. In this study, the presence of nonlinear dynamics was checked as a function of time scales in three experimental models of rats with different impairment of the cardiac control: namely, rats with heart failure (HF), spontaneously hypertensive rats (SHRs), and sinoaortic denervated (SAD) rats. Multiscale entropy (MSE) and refined MSE (RMSE) were chosen as the discriminating statistic for the surrogate test utilized to detect nonlinearity. Nonlinear dynamics is less present in HF animals at both short and long time scales compared with controls. A similar finding was found in SHR only at short time scales. SAD increased the presence of nonlinear dynamics exclusively at short time scales. Those findings suggest that a working baroreflex contributes to linearize HRV and to reduce the likelihood to observe nonlinear components of the cardiac control at short time scales. In addition, an increased sympathetic modulation seems to be a source of nonlinear dynamics at long time scales. Testing nonlinear dynamics as a function of the time scales can provide a characterization of the cardiac control complementary to more traditional markers in time, frequency, and information domains.NEW & NOTEWORTHY Although heart rate variability (HRV) dynamics is widely assumed to be nonlinear, nonlinearity tests are rarely used to check this hypothesis. By adopting multiscale entropy (MSE) and refined MSE (RMSE) as the discriminating statistic for the nonlinearity test, we show that nonlinear dynamics varies with time scale and the type of cardiac dysfunction. Moreover, as complexity metrics and nonlinearities provide complementary information, we strongly recommend using the test for nonlinearity as an additional index to characterize HRV.

KEY POINTS The integrity of the baroreflex control of sympathetic activity in heart failure (HF) remains under debate. We proposed the use of the sequence method to assess the baroreflex control of renal sympathetic nerve activity (RSNA). The sequence method assesses the spontaneous arterial pressure (AP) fluctuations and their related changes in heart rate (or other efferent responses), providing the sensitivity and the effectiveness of the baroreflex. Effectiveness refers to the fraction of spontaneous AP changes that elicits baroreflex-mediated variations in the efferent response. Using three different approaches, we showed that the baroreflex sensitivity between AP and RSNA is not altered in early HF rats. However, the sequence method provided evidence that the effectiveness of baroreflex in changing RSNA in response to AP changes is markedly decreased in HF. The results help us better understand the baroreflex control of the sympathetic nerve activity. ABSTRACT In heart failure (HF), the reflex control of the heart rate is known to be markedly impaired; however, the baroreceptor control of the sympathetic drive remains under debate. Applying the sequence method to a series of arterial pressure (AP) and renal sympathetic nerve activity (RSNA), we demonstrated a clear dysfunction in the baroreflex control of sympathetic activity in rats with early HF. We analysed the baroreflex control of the sympathetic drive using three different approaches: AP vs. RSNA curve, cross-spectral analysis and sequence method between AP and RSNA. The sequence method also provides the baroreflex effectiveness index (BEI), which represents the percentage of AP ramps that actually produce a reflex response. The methods were applied to control rats and rats with HF induced by myocardial infarction. None of the methods employed to assess the sympathetic baroreflex gain were able to detect any differences between the control and the HF group. However, rats with HF exhibited a lower BEI compared to the controls. Moreover, an optimum delay of 1 beat was observed, i.e. 1 beat is required for the RSNA to respond after AP changing, which corroborates with the findings related to the timing between these two variables. For delay 1, the BEI of the controls was 0.45 ± 0.03, whereas the BEI of rats with HF was 0.29 ± 0.09 (P

Analysis of heart rate variability (HRV) by nonlinear approaches has been gaining interest due to their ability to extract additional information from heart rate (HR) dynamics that are not detectable by traditional approaches. Nevertheless, the physiological interpretation of nonlinear approaches remains unclear. Therefore, we propose long-term (60 min) protocols involving selective blockade of cardiac autonomic receptors to investigate the contribution of sympathetic and parasympathetic function upon nonlinear dynamics of HRV. Conscious male Wistar rats had their electrocardiogram (ECG) recorded under three distinct conditions: basal, selective (atenolol or atropine), or combined (atenolol plus atropine) pharmacological blockade of autonomic muscarinic or β1-adrenergic receptors. Time series of RR interval were assessed by multiscale entropy (MSE) and detrended fluctuation analysis (DFA). Entropy over short (1 to 5, MSE1–5) and long (6 to 30, MSE6–30) time scales was computed, as well as DFA scaling exponents at short (αshort, 5 ≤ n ≤ 15), mid (αmid, 30 ≤ n ≤ 200), and long (αlong, 200 ≤ n ≤ 1,700) window sizes. The results show that MSE1–5 is reduced under atropine blockade and MSE6–30 is reduced under atropine, atenolol, or combined blockade. In addition, while atropine expressed its maximal effect at scale six, the effect of atenolol on MSE increased with scale. For DFA, αshort decreased during atenolol blockade, while the αmid increased under atropine blockade. Double blockade decreased αshort and increased αlong. Results with surrogate data show that the dynamics during combined blockade is not random. In summary, sympathetic and vagal control differently affect entropy (MSE) and fractal properties (DFA) of HRV. These findings are important to guide future studies. NEW & NOTEWORTHY Although multiscale entropy (MSE) and detrended fluctuation analysis (DFA) are recognizably useful prognostic/diagnostic methods, their physiological interpretation remains unclear. The present study clarifies the effect of the cardiac autonomic control on MSE and DFA, assessed during long periods (1 h). These findings are important to help the interpretation of future studies.

Background Denture-related stomatitis (DS) is chronic multifactorial inflammation, strongly related to the presence of the biofilm that is the complex structure formed by microorganisms held together by a mucus-like matrix of carbohydrate that adheres to different surfaces, including the denture surface. DS has recently been correlated with deleterious cardiovascular alterations. The potential effect of hygiene protocols in the control of DS and randomized clinical trials that address this oral condition with cardiovascular complications are important in clinical decision-making. Material/design A clinical trial, randomized, double-blind, and with parallel groups, will be conducted in Brazil The sample will consist of 100 patients without teeth in both arches, users of at least maxillary complete dentures, and diagnosed with DS, who will be allocated to groups (n = 25 per group) according to the different hygiene protocols: (1) brushing of the palate and immersion of the prosthesis in 0.25% sodium hypochlorite solution (positive control); (2) brushing of the palate and immersion of the prosthesis in 0.15% triclosan solution; (3) brushing of the palate and immersion of the prosthesis in lactose monohydrate; or (4) brushing the palate with citric acid and immersing the prosthesis in lactose monohydrate. The response variables will be heart rate variability and alteration of blood pressure (systemic level), remission of DS, removal of biofilm, reduction of microbial load (colony-forming units (CFU)), mouth and prosthesis odor level, expression of MUC1, proinflammatory cytokines, C-reactive protein (CRP), viscosity, pH and salivary flow (locally); patient-centred qualitative analysis will also be undertaken. Measurements will be performed at baseline and 10 days after the interventions. The results obtained will be statistically analyzed as pertinent, with a level of significance of 0.05. Discussion This study will provide a guideline for clinical practice regarding the use of hygiene protocols in the treatment of oral diseases (DS) mediated by biofilm. Also, it may provide evidence of correlation of oral manifestation with cardiac risk. Trial registration Brazilian Registry of Clinical Trials, RBR-4hhwjb. Registered on 9 November 2018.

Denture-related stomatitis (DRS) has recently been associated with harmful cardiovascular effects, including arterial hypertension. This study evaluated salivary parameters, blood pressure (BP) and heart rate variability (HRV), before and after the DRS treatment in edentulous patients (n=14). Collection of unstimulated and stimulated saliva, as well as blood pressure BP measurements and electrocardiogram recordings, were performed before and after ten days of DRS treatment. The salivary flow (mL/min) was found similar at both times while the pH was smaller (more neutral) after the treatment (7.3±2.2 vs. 7.1±0.24). The systolic BP (mmHg) showed a trend, but not a significant reduction after the DRS treatment (158±25.68 vs. 148±16,72, p=0,062) while diastolic BP was found similar in both times (86±13.93 and 84±9.38). Overall, the HRV measured by the standard deviation of RR intervals was not affected by DRS treatment (24±4 vs. 18±2 ms); but the differences of successive RR intervals (an index of parasympathetic cardiac modulation) increased after the treatment (26±4 vs. 19±2 ms). Moreover, another index of vagal modulation of the heart, i.e., the power of RR interval spectra at high-frequency, was also markedly higher after the DRS treatment (236±63 vs. 135±32 ms 2 ). Overall, these findings strongly suggest that the DRS is associated with an autonomic imbalance, particularly with sympathetic overactivity. Therefore, the DRS may be significantly harmful, increasing cardiovascular risk and the incidence of several diseases, for instance, arterial hypertension.

Background and aims Consumption of a high caloric diet induces autonomic imbalance, which can lead to cardiovascular disease. Impaired arterial baroreflex control is suggested to play an important role in cardiovascular autonomic imbalance, often seen in obesity. We previously demonstrated that cafeteria diets increase the sympathetic drive to white and brown adipose tissue. Methods and results After feeding a cafeteria diet to rats for 26 days, we evaluated: (i)heart rate (HR) and arterial pressure (AP); (ii)baroreflex and chemoreflex function; and (iii) autonomic modulation of the heart and vessels, measured through pulse interval (PI) and systolic arterial pressure (SAP) variability analyses and following administration of autonomic blockers. The cafeteria diet increased body fat mass and serum insulin, leptin, triacylglycerol and cholesterol levels. Baseline HR (15%) was also increased, accompanied by increased power in the low frequency band (60%) and in the low frequency/high frequency ratio (104%) in the PI spectra. Nonlinear analysis revealed an increased occurrence of 0V (39%) and decreased occurrence of 2UV (18%) patterns. Following administration of autonomic blockers, we observed an increase in cardiac sympathetic tone (425%) in cafeteria diet-fed rats. The cafeteria diet had no effect on AP, SAP variability, baroreflex and chemoreflex control. Conclusion Our findings suggest that consumption of a cafeteria diet increases sympathetic drive to the heart but not to the blood vessels, independent of impairment in baroreflex and chemoreflex functions. Other mechanisms may be involved in the increased cardiac sympathetic drive, and compensatory vascular mechanisms may prevent the development of hypertension in this model of obesity.

There is a body of evidence that supports the notion that gut dysbiosis plays a role in the pathogenesis of cardiovascular diseases. Decreased cardiac function can reduce intestinal perfusion, resulting in morphological alterations, which may contribute to changes in the gut microbiota composition in patients with heart failure (HF). In this regard, a germane question is whether changes in gut microbiota composition are a cause or consequence of the cardiovascular disturbance. We tested the hypothesis that the development of HF, after myocardial infarction, would cause gut dysbiosis. Fecal samples were collected before and 6 wk after myocardial infarction or sham surgery. Gut microbiota were characterized by sequencing the bacterial 16S ribosomal DNA. The composition of bacterial communities in the fecal samples was evaluated by calculating three major ecological parameters: 1) the Chao 1 richness, 2) the Pielou evenness, and 3) the Shannon index. None of these indices was changed in either sham or HF rats. The Firmicutes/Bacteroidetes ratio was not altered in HF rats. The number of species in each phylum was also not different between sham and HF rats. β-Diversity analysis showed that the composition of gut microbiota was not changed with the development of HF. Bacterial genera were grouped according to their major metabolic end-products (acetate, butyrate, and lactate), but no differences were observed in HF rats. Therefore, we conclude that HF induced by myocardial infarction does not affect gut microbiota composition, at least in rats, indicating that the dysbiosis observed in patients with HF may precede cardiovascular disturbance. NEW & NOTEWORTHY Our study demonstrated that, following myocardial infarction in rats, heart failure (HF) development did not affect the intestinal microbiota despite distinct differences reported in the gut microbiota of humans with HF. Our finding is consistent with the notion that dysbiosis observed in patients with HF may precede cardiovascular dysfunction and therefore offers potential for early diagnosis and treatment.

Lipopolysaccharide (LPS)-induced systemic inflammation (SI) is associated with hypotension, tachycardia, and multiple organs dysfunctions. SI, a hallmark of sepsis can lead to cardiovascular impair...

Cdc42, a member of the Rho GTPase family, is an intracellular signaling protein known for its roles in cytoskeleton rearrangements and, more recently, in apoptosis/senescence triggered by genotoxic stress. In some tumor cells, the overactivation of Cdc42 through the expression of constitutively active mutants (G12V or Q61L), GEF activation, or GAP downregulation functions as an antiproliferative or pro-aging mechanism. In this study, human cell lines with different P53 protein profiles were exposed to UV radiation, and the interactions between Cdc42 and proteins that are putatively involved in the DNA damage response and repair mechanisms were screened. The affinity-purified proteins obtained through pull-down experiments of the cell lysates using the recombinant protein baits GST, GST-Cdc42-WT, or GST-Cdc42-G12V were identified by mass spectrometry. The resulting data were filtered and used for the construction of protein-protein interaction networks. Among several promising proteins, three targets, namely, PAK4, PHB-2, and 14-3-3η, which are involved in the cell cycle, apoptosis, DNA repair, and chromatin remodeling processes, were identified. Biochemical validation experiments showed physical and proximal interactions between Cdc42 and the three targets in the cells, particularly after exposure to UV. The results suggest that the molecular mechanisms coordinated by overactivated Cdc42 (with the G12V mutation) to increase the cellular sensitivity to UV radiation and the susceptibility to cell death are collectively mediated by these three proteins. Therefore, the Cdc42 GTPase can potentially be considered another player involved in maintenance of the genomic stability of human cells during exposure to genotoxic stress.

The sequence method is an important approach to assess the baroreflex function, mainly because it is based on the spontaneous fluctuations of beat-by-beat arterial pressure (for example, systolic arterial pressure or SAP) and pulse interval (PI). However, some studies revealed that the baroreflex effectiveness index (BEI), calculated through the sequence method, shows an intriguing oscillatory pattern as function of the delay between SAP and PI. It has been hypothesized that this pattern is related to the respiratory influence on SAP and/or PI variability, limiting the SAP ramps to 3 or 4 beats of length. In this study, this hypothesis was tested by assessing the sequence method using raw (original) and filtered series. Results were contrasted to the well-established transfer function, estimated between SAP and PI. Continuous arterial pressure recordings were obtained from healthy rats (N = 61) and beat-by-beat series of SAP and PI were generated. Low-pass (LP) and high-pass (HP) filtered series of SAP and PI were created by filtering the original series with a cutoff frequency of 0.8 Hz. Original series were analyzed by either the sequence method or cross-spectral analysis (transfer function) at low- (LF) and high- (HF) frequency bands, while filtered series were evaluated only by the sequence method. Baroreflex sensitivity (BRS) and BEI of original series, calculated by sequence method, was highly (85–90%) determined by HP series, with no significant association between original and LP series. A high correlation (>0.7) was found between the BRS estimated from original series (sequence method) and HF band (transfer function), as well as for LP series (sequence method) and LF band (transfer function). These findings confirmed the hypothesis that the sequence method quantifies only the high-frequency components of the baroreflex, neglecting the low-frequency influences, such as the Mayer waves. Therefore, we propose using both the original and LP filtered time series for a broader assessment of the baroreflex function using the sequence method.

Geopolymers are presented as a new developing construction material and a potential alternative to ordinary binders, but there is a lack of data about several of their properties and behavior – joint-effect with cellulose is one example. The present study investigated the influence of Microcrystalline Cellulose (MCC) addition on the mechanical and microstructural properties of Portland cement and geopolymer pastes. The use of MCC increases compressive strength and stiffness at 7 days to both studied binders. After 28 days, the mechanical properties of the geopolymer paste are reduced due to MCC degradation. On the other hand, MCC addition accelerated geopolymer setting time by 15%, whereas on the cement paste yield a considerable delay effect.

The classical small Rho GTPase (Rho, Rac, and Cdc42) protein family is mainly responsible for regulating cell motility and polarity, membrane trafficking, cell cycle control, and gene transcription. Cumulative recent evidence supports important roles for these proteins in the maintenance of genomic stability. Indeed, DNA damage response (DDR) and repair mechanisms are some of the prime biological processes that underlie several disease phenotypes, including genetic disorders, cancer, senescence, and premature aging. Many reports guided by different experimental approaches and molecular hypotheses have demonstrated that, to some extent, direct modulation of Rho GTPase activity, their downstream effectors, or actin cytoskeleton regulation contribute to these cellular events. Although much attention has been paid to this family in the context of canonical actin cytoskeleton remodeling, here we provide a contextualized review of the interplay between Rho GTPase signaling pathways and the DDR and DNA repair signaling components. Interesting questions yet to be addressed relate to the spatiotemporal dynamics of this collective response and whether it correlates with different subcellular pools of Rho GTPases. We highlight the direct and indirect targets, some of which still lack experimental validation data, likely associated with Rho GTPase activation that provides compelling evidence for further investigation in DNA damage-associated events and with potential therapeutic applications in translational medicine.

This experimental investigation aims to study the influence of temperature on natural fibers mechanical performance and on its interface to cement based systems. Natural sisal fiber was used on this study. Temperatures of 20, 100, 150, 200, 250 and 300 °C were used as conditions for this research. The influence of temperature on this fiber was evaluated by scanning electron microscopy (SEM), x-ray diffraction patterns (XRD), thermogravimetric analysis (TGA). The mechanical properties were evaluated by tensile test. Pullout test were performed in order to evaluate bonding on cement-based matrix after exposition to higher temperatures. The results indicate a minor modification on sisal morphology after temperature exposition until 200 °C. At 250 °C a few microcracks were observed on fiber surface, indicating a debonding of sisal fibercells and microfibrils. Sisal mechanical behavior was improved until 150 °C. This may happen due the water evaporation and shrinkage, promoting a closed and densified fiber structure. Cement main component degradation was observed before degradation of the natural fiber (around 250 °C). Bonding to cement matrix decreased after 100 °C and was maintained stable until 150 °C, and resulted in pullout forces reduction of 75% in comparison to fiber tested at 20 °C.

Commercializing dried microfibrillated cellulose (MFC) has always been a challenge mainly due to the tendency of MFC to aggregate. In this study MFC samples were submitted to drying/redispersion cycles at different temperatures. Morphology, crystallinity and mechanical performance of films were analyzed throughout the cycles. Microscopy images, particle size and stability in water showed that aggregation happens more severely with 5 drying/redispersion cycles and at drying temperatures of 75 and 100 °C. Particles once-dried at 20 °C formed the same size and web-like structure as the MFC-control. Crystallinity and crystallite sizes increased with drying/redispersion cycles especially when dried at 75 and 100 °C, however drying/redispersion cycles also led to a reduction in mechanical performance due to aggregation. While oven-drying is not the most suitable method, milder action at room temperature once-drying led to suspension stability in water, morphology and mechanical properties close to never-dried MFC, which makes this treatment a feasible option to maintain cellulose quality.

Background and Objective Several software applications have been proposed in the past years as computational tools for assessing biomedical signals. Many of them are focused on heart rate variability series only, with their strengths and limitations depending on the necessity of the user and the scope of the application. Here, we introduce new software, named PyBioS, intended for the analysis of cardiovascular signals, even though any type of biomedical signal can be used. PyBioS has some functionalities that differentiate it from the other software. Methods PyBioS was developed in Python language with an intuitive, user-friendly graphical user interface. The basic steps for using PyBioS comprise the opening or creation (simulation) of signals, their visualization, preprocessing and analysis. Currently, PyBioS has 8 preprocessing tools and 15 analysis methods, the later providing more than 50 metrics for analysis of the signals’ dynamics. Results The possibility to create simulated signals and save the preprocessed signals is a strength of PyBioS. Besides, the software allows batch processing of files, making the analysis of a large amount of data easy and fast. Finally, PyBioS has plenty of analysis methods implemented, with the focus on nonlinear and complexity analysis of signals and time series. Conclusions Although PyBioS is not intended to overcome all the necessities from users, it has useful functionalities that may be helpful in many situations. Moreover, PyBioS is continuously under improvement and several simulated signals, tools and analysis methods are still to be implemented. Also, a new module is being implemented on it to provide machine learning algorithms for classification and regression of data extracted from the biomedical signals.