Search results for "Biomedical engineering"
showing 10 items of 2020 documents
Biotechnological and environmental microbiological research in the Baltic region
2014
New epicardial mapping electrode with warming/cooling function for experimental electrophysiology studies
2010
Cardiac electrical activity is influenced by temperature. In experimental models, the induction of hypothermia and/or hyperthermia has been used for the study of mechanisms of cardiac arrhythmia. A system that allows for localized, controlled induction, besides simultaneously recording electrical activity in the same induced area, needs to be developed ad hoc. This article describes the construction and application of a new system capable of locally modifying the epicardial temperature of isolated hearts and of carrying out cardiac mapping with sufficient spatial resolution. The system is based on a thermoelectric refrigerator and an array of 128 stainless steel unipolar electrodes in encap…
Réflexions sur l’identification du patient dans les systèmes d’information de santé
2008
Resume Objectif Le but de notre etude est de faire le point sur les concepts de base et les methodologies mises en œuvre dans les systemes d’informations de sante pour identifier le patient. Methodologie La methode utilisee est une analyse des contraintes intrinseques et extrinseques des systemes deja utilisees liees respectivement a leurs objectifs et aux exigences ethiques ; et une recherche d’assise methodologique ouverte, evolutive basee sur le constat illusoire d’identifiant unique et universel. Resultat Malgre de nombreuses contraintes notre analyse des differents travaux montre que certaines solutions sont envisageables. Celles-ci sont centrees sur un modele simple d’identification r…
Photoplethysmography for bovine heat detection: the preliminary results
2020
In this study, we applied photoplethysmography (PPG) as an alternative, convenient, and affordable method for bovine heat detection. Heat detection is an essential part of effective herd reproduction management. Currently, there are many different heat detection techniques, but they can be ineffective or impractical to use. Since heat affects local vulvar blood circulation (resulting in swelling and erythema), photoplethysmography could represent an affordable alternative to detect this bovine phenomenon. In this study, we enrolled 20 animals in heat and other stages of the bovine reproduction cycle. We analyzed the PPG signal in terms of baseline (DC component), power, kurtosis, and erythe…
Microwave-assisted synthesis of PHEA-oligoamine copolymers as potential gene delivery systems
2009
Aims - Copolymers bearing oligoamines and having buffering capacity in the endosomal pH range seems very promising as non viral vectors in gene delivery, due to the great importance of endosomal escaping for an efficient endocellular DNA release. Aim of this paper was to prepare new copolymers based on α,β-poly-(N-2-hydroxyethyl)-D,L-aspartamide (PHEA) as polymeric backbone and bearing an oligoamine, such as diethylentriamine (DETA) in the side chain and useful for gene delivery. Moreover in order to reduce solvent volume and to make faster the reaction, microwave-assisted has been used. Materials and methods - PHEA copolymers bearing different amount of DETA were prepared by using bis(4-ni…
New pegylated polyaspartamide-based polyplexes as gene delivery vectors
2010
Aims: To synthesize novel polyhydroxyethylaspartamide (PHEA) copolymers containing spermine (Spm) and polyethylene glycol (PEG) moieties in high yields, with the expectation that this material would show stealth properties and the ability to complex DNA by electrostatic interactions. Materials & methods: PHEA–PEG–Spm copolymer was prepared with a two-step reaction. Chemical, physicochemical and biological characterizations of PHEA–PEG–Spm copolymers and their obtained polyplexes with pDNA were performed. Results: The introduction of spermine in PHEA structure allows to obtain a copolymer bearing in the side chains polyamine moieties capable to interact with DNA. On the other hand, the …
Accurate single-shot quantitative phase imaging of biological specimens with telecentric digital holographic microscopy
2014
The advantages of using a telecentric imaging system in digital holographic microscopy (DHM) to study biological specimens are highlighted. To this end, the performances of nontelecentric DHM and telecentric DHM are evaluated from the quantitative phase imaging (QPI) point of view. The evaluated stability of the microscope allows single-shot QPI in DHM by using telecentric imaging systems. Quantitative phase maps of a section of the head of the drosophila melanogaster fly and of red blood cells are obtained via single-shot DHM with no numerical postprocessing. With these maps we show that the use of telecentric DHM provides larger field of view for a given magnification and permits more acc…
Alterations in the Microstructure of the Anterior Mitral Valve Leaflet Under Physiological Stress
2012
An improved understanding of mitral valve (MV) function remains an important goal for determining mechanisms underlying valve disease and for developing novel therapies. Critical to heart valve tissue homeostasis is the valvular interstitial cells (VICs), which reside in the interstitium and maintain the extracellular matrix (ECM) through both protein synthesis and enzymatic degradation [1]. There is scant quantitative experimental data on the alterations of the MV fiber network reorganization as a function of load, which is critical for implementation of computational strategies that attempt to link this meso-micro scale phenomenon. The observed large scale deformations experienced by VICs…
Exposure to radial extracorporeal shockwaves induces muscle regeneration after muscle injury in a surgical rat model
2019
The leading cause of training interruption in sport is a muscle injury, for which the standard treatment is nonsteroidal anti-inflammatory drugs (NSAIDs). To find alternative treatments, we investigated whether the radial extracorporeal shockwave application (rESWT) could stimulate muscle regeneration. A lesion with complete rupture (grade III muscle tear) was set in the musculus rectus femoris of 12-week-old Wistar rats, and the NSAID diclofenac, rESWT, or a combined therapy were applied on day 0, 3, and 5 directly following the surgery. Rats were euthanized at 2, 4, and 7 days after surgery and the area of muscle lesion was excised for histological and gene expression analysis to determin…
Expanding the Active Inference Landscape: More Intrinsic Motivations in the Perception-Action Loop
2018
Active inference is an ambitious theory that treats perception, inference and action selection of autonomous agents under the heading of a single principle. It suggests biologically plausible explanations for many cognitive phenomena, including consciousness. In active inference, action selection is driven by an objective function that evaluates possible future actions with respect to current, inferred beliefs about the world. Active inference at its core is independent from extrinsic rewards, resulting in a high level of robustness across e.g.\ different environments or agent morphologies. In the literature, paradigms that share this independence have been summarised under the notion of in…