Search results for " BIOMEDICAL"

A bio-imitating approach to fabricate an artificial matrix for cartilage tissue engineering using magnesium-polyphosphate and hyaluronic acid

2016

Here we describe an artificial cartilage-like material based on a hyaluronic acid-Mg/Ca-polyphosphate paste (HA-aMg/Ca-polyP-p) that is fabricated from a water-soluble Na-salt of energy-rich inorganic polyphosphate (polyP) and soluble hyaluronic acid in the presence of water-insoluble CaCO3. The resulting material, after conversion of Na-polyP into the less soluble Mg/Ca-salt consisting of amorphous Mg/Ca-polyP microparticles, was found to mimic the physiological cartilage tissue and to bind Ca2+ ions present in the synovial fluid. After the Mg2+/Ca2+ exchange and water extrusion, the polyP becomes more stable, but is still susceptible to hydrolytic cleavage by the alkaline phosphatase (ALP…

Interest of exome sequencing trio-like strategy based on pooled parental DNA for diagnosis and translational research in rare diseases.

2021

Abstract Background Exome sequencing (ES) has become the most powerful and cost‐effective molecular tool for deciphering rare diseases with a diagnostic yield approaching 30%–40% in solo‐ES and 50% in trio‐ES. We applied an innovative parental DNA pooling method to reduce the parental sequencing cost while maintaining the diagnostic yield of trio‐ES. Methods We pooled six (Agilent‐CRE‐v2–100X) or five parental DNA (TWIST‐HCE–70X) aiming to detect allelic balance around 8–10% for heterozygous status. The strategies were applied as second‐tier (74 individuals after negative solo‐ES) and first‐tier approaches (324 individuals without previous ES). Results The allelic balance of parental‐pool v…

Distributed and Lumped Parameter Models for the Characterization of High Throughput Bioreactors

2016

Next generation bioreactors are being developed to generate multiple human cell-based tissue analogs within the same fluidic system, to better recapitulate the complexity and interconnection of human physiology. The effective development of these devices requires a solid understanding of their interconnected fluidics, to predict the transport of nutrients and waste through the constructs and improve the design accordingly. In this work, we focus on a specific model of bioreactor, with multiple input/outputs, aimed at gen- erating osteochondral constructs, i.e., a biphasic construct in which one side is cartilagi- nous in nature, while the other is osseous. We next develop a general computat…

Mitochondrial DNA mutations in cancer--from bench to bedside.

2009

Mitochondria are cell organelles mostly known for their production of ATP through oxidative phosphorylation. As suggested over 70 years ago by O. Warburg and recently confirmed with molecular techniques, alterations in respiratory activity and mitochondrial DNA appear to be a common feature of malignant cells. Somatic mtDNA mutations have been reported in many types of cancer cells. MtDNA mutation pattern may enhance the specificity of cancer diagnostics, detection and prediction of tumor growth rate and patients' outcome. Therefore it may be used as a molecular cancer bio-marker. Nevertheless recently published papers list a large number of mitochondrial DNA mutations in many different can…

Comparison of region of interest segmentation methods for video-based heart rate measurements

2018

International audience; Conventional contact photoplethysmography (PPG) sensors are not suitable in situations of skin damage or when unconstrained movement is required. As a consequence, remote photoplethysmography (rPPG) has recently emerged because it provides remote physiological measurements without expensive hardware and improves comfort for long-term monitoring. RPPG estimation methods use the spatially averaged RGB values of pixels in a Region Of Interest (ROI) to generate a temporal RGB signal. The selection of ROI is a critical first step to obtain reliable pulse signals and must contain as many skin pixels as possible with a low percentage of non-skin pixels. In this paper, we ex…

Measuring the Rate of Information Transfer in Point-Process Data: Application to Cardiovascular Interactions

2021

We present the implementation to cardiovascular variability of a method for the information-theoretic estimation of the directed interactions between event-based data. The method allows to compute the transfer entropy rate (TER) from a source to a target point process in continuous time, thus overcoming the severe limitations associated with time discretization of event-based processes. In this work, the method is evaluated on coupled cardiovascular point processes representing the heartbeat dynamics and the related peripheral pulsation, first using a physiologically-based simulation model and then studying real point-process data from healthy subjects monitored at rest and during postural …

Quantifying multidimensional control mechanisms of cardiovascular dynamics during multiple concurrent stressors

2021

Heartbeat regulation is achieved through different routes originating from central autonomic network sources, as well as peripheral control mechanisms. While previous studies successfully characterized cardiovascular regulatory mechanisms during a single stressor, to the best of our knowledge, a combination of multiple concurrent elicitations leading to the activation of different autonomic regulatory routes has not been investigated yet. Therefore, in this study, we propose a novel modeling framework for the quantification of heartbeat regulatory mechanisms driven by different neural routes. The framework is evaluated using two heartbeat datasets gathered from healthy subjects undergoing p…

Remote Photoplethysmography measurement using constrained ICA

2017

Remote Photoplethysmography (rPPG) is a technique that consists in estimating physiological parameters such as heart rate from live or recorded video sequences taken by conventional camera or even webcams. This technique is increasingly used in many application fields thanks to its simplicity and affordability. The basic idea is that the arterial blood flow shows regularity due to the heartbeat. This regularity is manifested by very small periodic variations in the color of the skin, which can be isolated and quantified by signal and image processing methods. In this context, Independent Component Analysis (ICA) is largely used to separate the signal due to arterial flow from signals from o…

Does shoe heel-to-toe drop have an influence on performance in downhill trail running?

2019

Trail running (TR) is characterized by sequences of uphill and downhill performed in a natural environment. Recently, studies investigated performance factors specific to TR. During a full race of ...

2019

Despite substantial advances in many different fields of neurorobotics in general, and biomimetic robots in particular, a key challenge is the integration of concepts: to collate and combine research on disparate and conceptually disjunct research areas in the neurosciences and engineering sciences. We claim that the development of suitable robotic integration platforms is of particular relevance to make such integration of concepts work in practice. Here, we provide an example for a hexapod robotic integration platform for autonomous locomotion. In a sequence of six focus sections dealing with aspects of intelligent, embodied motor control in insects and multipedal robots-ranging from comp…