Wearable estimation of central aortic blood pressure : Feasibility study.

http://revistasabi.fi.mdp.edu.ar/index.php/revista/article/view/291Introduction: Central aortic blood pressure (CABP) estimation from electrocardiogram (ECG) and ballistocardiogram (BCG) acquisitions might be feasible, according to previous research. The result is based on acquisitions with off-the-shelf equipment and some custom electronics. This work aims to evaluate whether a proposed wearable device is capable of achieving similar feasibility results on CABP estimation, but also the study aims to situate the scope of this method to predict CABP readings. Methods: The study used data from one healthy subject involving three days of intermittent CABP observations, and waveforms from ECG and BCG signals. The methodology was evaluated in two levels, from a simple perspective to evaluate feasibility of the method for the CABP estimation ( Evaluation level-1: CABP human-model (HM) is constructed and tested using the same data-sets); to moderate-hard by evaluating the capability of the calibrated CABP-HM to predict unseen CABP data accurately (Evaluation level-2). CABP variables were assessed non-invasively by the use of the SphygmoCor XCEL system (AtCor Medical, Sydney, Australia) during hemodynamic maneuvers. Results: Level-1 evaluation presented strong correlations of r ? 0.9, and strong agreement (linear regression parameters) m ? 0.8 and y ? 20mmHg between CABP measurements and estimations. Root mean square error of RMSE ? 2.3mmHg. The level-2 evaluation showed significantly degraded performances when the same figures of merit were assessed. A three-day calibration interval was considered for the level-2 evaluation. Conclusions: Findings in this paper showed that results achieved with off-the-shelf equipment could be replicated by using a proposed wearable device. CABP estimation from the proposed wearable device could be feasible by using three feature times studied in this work (RI, RJ, and IJ intervals) as CABP surrogates. CABP could be accurately predicted by the proposed methodology when (in the order of) daily calibrations are performed.Introducción: Recientemente se ha mostrado que la estimación de la presión aóortica central (PAc) a partir de electrocardiograma (ECG) y el balistocardiograma (BCG) podría ser factible, el resultado es basado en adquisición con equipos convencionales y electrónica custom. Este trabajo tiene como objetivo evaluar si el dispositivo vestíble que se propone es capaz de lograr resultados de factibilidad similares para la estimación Pac, adicionalemente se busca situar el alcance de este método para predecir con precisión PAc. Métodos: El estudio utilizó 67 datos de un sujeto saludable que incluyó tres días de observaciones intermitentes de PAc y formas de onda de se ñales de ECG y BCG. La metodología se evaluó en dos niveles. Evaluación nivel-1 (para estudiar la factibilidad del método): el modelo humano(HM) de PAc se construyó y testeó utilizando el mismo conjuntos de datos. La evaluación nivel-2 evaluó la capacidad del PAc-MH calibrado para predecir datos nuevos de PAc. Las variables PAc se midieron de forma no-invasiva utilizando el equipo SphygmoCor XCEL durante maniobras hemodinámicas. Resultados: la evaluación de nivel-1 presentó fuertes correlaciones de r ≈ 0.9, y una fuerte concordancia (parámetros de regresión lineal) m≈ 0.8 e y ≈ 20mmHg entre las mediciones y estimaciones de PAc. La evaluación de nivel-2 mostró rendimientos significativamente degradados cuando se evaluaron las mismas cifras de mérito. Se consideró un intervalo de calibración de tres días para la evaluacón de nivel-2. Conclusiones: los resultados logrados en el trabajo anterior podrían replicarse mediante el uso del dispositivo vestíble propuesto; y, la estimación CABP podría ser factible utilizando tres tiempos de características estudiados en este trabajo (intervalos RI, RJ e IJ). Además, si se considera un intervalo de calibración dentro del día, la metodología propuesta podría lograr estimaciones precisas de la Pac

Nonlinear Systems in Healthcare towards Intelligent Disease Prediction

Healthcare is one of the key fields that works quite strongly with advanced analytical techniques for prediction of diseases and risks. Data being the most important asset in recent times, a huge amount of health data is being collected, thanks to the recent advancements of IoT, smart healthcare, etc. But the focal objective lies in making sense of that data and to obtain knowledge, using intelligent analytics. Nonlinear systems find use specifically in this field, working closely with health data. Using advanced methods of machine learning and computational intelligence, nonlinear analysis performs a key role in analyzing the enormous amount of data, aimed at finding important patterns and predicting diseases. Especially in the field of smart healthcare, this chapter explores some aspects of nonlinear systems in predictive analytics, providing a holistic view of the field as well as some examples to illustrate such intelligent systems toward disease prediction

Fractal Analysis of Cardiovascular Signals Empowering the Bioengineering Knowledge

The cardiovascular system is composed of a complex network of vessels, where highly uniform hierarchical branching structures are regulated by the anatomy and local flow requirements. Arteries bifurcate many times before they become capillaries where the scaling factor of vessel length, diameter and angle between two children branches is established at each level of recurrence. This behaviour can be easily described using a fractal scaling principle. Moreover, it was observed that the basic pattern of blood distribution is also fractal, imposed both by the anatomy of the vascular tree and the local regulation of vascular tone. In this chapter, arterial physiology was analysed, where waveform complexity of arterial pressure time series was related to arterial stiffness changes, pulse pressure variations and the presence wave reflection. Fractal dimension was used as a nonlinear measure, giving place to a ‘holistic approach of fractal dimension variations throughout the arterial network’, both in health and disease

Dielectric spectroscopy of PP/MWCNT nanocomposites: Relationship with crystalline structure and injection molding condition

In this paper, we study the correlation between the dielectric behavior of polypropylene/multi-walled carbon nanotube (PP/MWCNT) nanocomposites and the morphology with regard to the crystalline structure, nanofiller dispersion and injection molding conditions. As a result, in the range of the percolation threshold the dielectric behavior shifts to a more frequency-independent behavior, as the mold temperature increases. Moreover, the position further from the gate appears as the most conductive. This effect has been associated to a modification of the morphology of the MWCNT clusters induced by both the flow of the molten polymer during the processing phase and the variation of the crystalline structure, which is increasingly constituted by γ-phase as the mold temperature increases. The obtained results allow one to understand the effect of tuning the processing condition in the frequency-dependent electrical behavior of PP/MWCNT injection-molded nanocomposites, which can be successfully exploited for an advanced process/product design

5-(carbamoylmethylene)-oxazolidin-2-ones as a promising class of heterocycles inducing apoptosis triggered by increased ROS levels and mitochondrial dysfunction in breast and cervical cancer

Oxazolidinones are antibiotics that inhibit protein synthesis by binding the 50S ribosomal subunit. Recently, numerous worldwide researches focused on their properties and possible involvement in cancer therapy have been conducted. Here, we evaluated in vitro the antiproliferative activity of some 5-(carbamoylmethylene)-oxazolidin-2-ones on MCF-7 and HeLa cells. The tested compounds displayed a wide range of cytotoxicity on these cancer cell lines, measured by MTT assay, exhibiting no cytotoxicity on non-tumorigenic MCF-10A cells. Among the nine tested derivatives, four displayed a good anticancer potential. Remarkably, OI compound showed IC50 values of 17.66 and 31.10 µM for MCF-7 and HeLa cancer cells, respectively. Furthermore, we assessed OI effect on the cell cycle by FACS analysis, highlighting a G1 phase arrest after 72 h, supported by a low expression level of Cyclin D1 protein. Moreover, mitochondrial membrane potential was reduced after OI treatment driven by high levels of ROS. These findings demonstrate that OI treatment can inhibit MCF-7 and HeLa cell proliferation and induce apoptosis by caspase-9 activation and cytochrome c release in the cytosol. Hence, 5-(carbamoylmethylene)-oxazolidin-2-ones have a promising anticancer activity, in particular, OI derivative could represent a good candidate for in vivo further studies and potential clinical use

Analysis of ischaemic crisis using the informational causal entropy-complexity plane

In the present work, an ischaemic process, mainly focused on the reperfusion stage, is studied using the informational causal entropy-complexity plane. Ischaemic wall behavior under this condition was analyzed through wall thickness and ventricular pressure variations, acquired during an obstructive flow maneuver performed on left coronary arteries of surgically instrumented animals. Basically, the induction of ischaemia depends on the temporary occlusion of left circumflex coronary artery (which supplies blood to the posterior left ventricular wall) that lasts for a few seconds. Normal perfusion of the wall was then reestablished while the anterior ventricular wall remained adequately perfused during the entire maneuver. The obtained results showed that system dynamics could be effectively described by entropy-complexity loops, in both abnormally and well perfused walls. These results could contribute to making an objective indicator of the recovery heart tissues after an ischaemic process, in a way to quantify the restoration of myocardial behavior after the supply of oxygen to the ventricular wall was suppressed for a brief period.Fil: Legnani, Walter. Universidad Tecnológica Nacional. Facultad Regional Buenos Aires; Argentina. Universidad Nacional de Lanús; ArgentinaFil: Traversaro Varela, Francisco. Instituto Tecnológico de Buenos Aires; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Redelico, Francisco Oscar. Hospital Italiano; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Quilmes; ArgentinaFil: Cymberknop, Leandro Javier. Instituto Tecnologico de Buenos Aires. Departamento de Bioingenieria; Argentina. Universidad Tecnológica Nacional. Facultad Regional Buenos Aires; ArgentinaFil: Armentano, Ricardo Luis. Universidad Tecnológica Nacional. Facultad Regional Buenos Aires; Argentina. Instituto Tecnologico de Buenos Aires. Departamento de Bioingenieria; ArgentinaFil: Rosso, Osvaldo Aníbal. Universidad de los Andes; Chile. Universidade Federal de Alagoas; Brasil. Hospital Italiano; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Diabetic retinopathy, oxidative stress and sirtuins: an in depth look in enzymatic patterns and new therapeutic horizons

Diabetic retinopathy (DR) is one of the leading causes of blindness in the world. DR represents the most common microvascular complication of diabetes, and its incidence is constantly rising. The complex interactions between inflammation, oxidative stress, and the production of free oxygen radicals caused by prolonged exposure to hyperglycemia determine the development of DR. Sirtuins (SIRTs) are a recently discovered class of 7 histone deacetylases involved in cellular senescence, regulation of cell cycle, metabolic pathways, and DNA repair. SIRTs participate in the progress of several pathologies such as cancer, neurodegenerative and metabolic diseases. In DR, sirtuins 1,3,5 and 6 play an important role as they regulate the activation of the inflammatory response, insulin sensibility, and both glycolysis and gluconeogenesis. A wide spectrum of direct and indirect activators of SIRTs pathways (e.g. antagomiR, resveratrol, or glycyrrhizin) is currently being developed to treat the inflammatory cascade occurring in DR. We focuse on the main metabolic and inflammatory pathways involving SIRTs and DR, as well as recent evidence on SIRTs activators that may be employed as novel therapeutic approaches to DR

Effect of injection molding conditions on crystalline structure and electrical resistivity of PP/MWCNT nanocomposites

Polypropylene (PP) / multi-walled carbon nanotube (MWCNT) nanocomposites were prepared by melt-mixing and used to manufacture samples by injection molding. The effect of processing conditions on the crystallinity and electrical resistivity was studied. Accordingly, samples were produced varying the mold temperature and injection rate, and the DC electrical resistivity was measured. The morphology of MWCNT clusters was studied by optical and electron microscopy, while X-ray diffraction was used to study the role of the crystalline structure of PP. As a result, an anisotropic electrical behavior induced by the process was observed, which is further influenced by the injection molding processing condition. It was demonstrated that a reduction of electrical resistivity can be obtained by increasing mold temperature and injection rate, which was associated to the formation of the γ-phase and the related inter-cluster morphology of the MWCNT conductive network

Quiescent neuronal progenitors are activated in the juvenile guinea pig lateral striatum and give rise to transient neurons

In the adult brain, active stem cells are a subset of astrocytes residing in the subventricular zone (SVZ) and the dentate gyrus (DG) of the hippocampus. Whether quiescent neuronal progenitors occur in other brain regions is unclear. Here, we describe a novel neurogenic system in the external capsule and lateral striatum (EC-LS) of the juvenile guinea pig that is quiescent at birth but becomes active around weaning. Activation of neurogenesis in this region was accompanied by the emergence of a neurogenic-like niche in the ventral EC characterized by chains of neuroblasts, intermediate-like progenitors and glial cells expressing markers of immature astrocytes. Like neurogenic astrocytes of the SVZ and DG, these latter cells showed a slow rate of proliferation and retained BrdU labeling for up to 65 days, suggesting that they are the primary progenitors of the EC-LS neurogenic system. Injections of GFPtagged lentiviral vectors into the SVZ and the EC-LS of newborn animals confirmed that new LS neuroblasts originate from the activation of local progenitors and further supported their astroglial nature. Newborn EC-LS neurons existed transiently and did not contribute to neuronal addition or replacement. Nevertheless, they expressed Sp8 and showed strong tropism for white matter tracts, wherein they acquired complex morphologies. For these reasons, we propose that EC-LS neuroblasts represent a novel striatal cell type, possibly related to those populations of transient interneurons that regulate the development of fiber tracts during embryonic life