Search results for "Biomedical"
showing 10 items of 2328 documents
Textureless macula swelling detection with multiple retinal fundus images
2011
Retinal fundus images acquired with nonmydriatic digital fundus cameras are versatile tools for the diagnosis of various retinal diseases. Because of the ease of use of newer camera models and their relatively low cost, these cameras can be employed by operators with limited training for telemedicine or point-of-care (PoC) applications. We propose a novel technique that uses uncalibrated multiple-view fundus images to analyze the swelling of the macula. This innovation enables the detection and quantitative measurement of swollen areas by remote ophthalmologists. This capability is not available with a single image and prone to error with stereo fundus cameras. We also present automatic alg…
A study on the effect of contact pressure during physical activity on photoplethysmographic heart rate measurements
2020
Heart rate (HR) as an important physiological indicator could properly describe global subject&rsquo
Semi-automated and interactive segmentation of contrast-enhancing masses on breast DCE-MRI using spatial fuzzy clustering
2022
Abstract Multiparametric Magnetic Resonance Imaging (MRI) is the most sensitive imaging modality for breast cancer detection and is increasingly playing a key role in lesion characterization. In this context, accurate and reliable quantification of the shape and extent of breast cancer is crucial in clinical research environments. Since conventional lesion delineation procedures are still mostly manual, automated segmentation approaches can improve this time-consuming and operator-dependent task by annotating the regions of interest in a reproducible manner. In this work, a semi-automated and interactive approach based on the spatial Fuzzy C-Means (sFCM) algorithm is proposed, used to segme…
Synthesis of Silver Gallium Selenide (AgGaSe2) Nanotubes and Nanowires by Template-Based Electrodeposition
2020
In this work, a systematic investigation of the different parameters that control the electrodeposition processes was carried out at the aim to synthetizing AgGaSe₂ nanostructures. We found that pH is a key parameter to control both the morphology and composition of the nanostructures. Low pH favours mainly the formation of Ag2Se nanotubes with a scarce mechanical stability, while multi-phase nanowires well anchored to the substrate were obtained at higher pH. We also found that it was necessary to increase dramatically the concentration of the gallium precursor into the deposition bath in order to obtain AgGaSe₂ owing to lower redox potential of the Ga3+/Ga couple than Ag2+/Ag and Se4+/Se.…
Consensus report from the 9th International Forum for Liver Magnetic Resonance Imaging: applications of gadoxetic acid-enhanced imaging
2021
Abstract Objectives The 9th International Forum for Liver Magnetic Resonance Imaging (MRI) was held in Singapore in September 2019, bringing together radiologists and allied specialists to discuss the latest developments in and formulate consensus statements for liver MRI, including the applications of gadoxetic acid–enhanced imaging. Methods As at previous Liver Forums, the meeting was held over 2 days. Presentations by the faculty on days 1 and 2 and breakout group discussions on day 1 were followed by delegate voting on consensus statements presented on day 2. Presentations and discussions centered on two main meeting themes relating to the use of gadoxetic acid–enhanced MRI in primary l…
MRI-Visible Poly(ε-caprolactone) with Controlled Contrast Agent Ratios for Enhanced Visualization in Temporary Imaging Applications
2013
International audience; Hydrophobic macromolecular contrast agents (MMCAs) are highly desirable to provide safe and efficient magnetic resonance (MR) visibility to implantable medical devices. In this study, we report on the synthesis and evaluation of novel biodegradable poly(ε-caprolactone)-based MMCAs. Poly(α-propargyl-ε-caprolactone-co-ε-caprolactone)s containing 2, 5, and 10 mol % of propargyl groups have been prepared by ring-opening copolymerization of ε-caprolactone and the corresponding propargylated lactone. In parallel, a diazido derivative of the clinically used diethylenetriaminepentaacetic acid (DTPA)/Gd3+ complex has been synthesized. Finally, MRI-visible poly(ε-caprolactone)…
In vivo measurement of gastric fluid volume in anesthetized dogs
2020
Abstract The drug solubility is critical for the Biopharmaceutics Classification System (BCS), yet the criteria for solubility have not been precisely defined for dogs. In particular, the gastric fluid volume (GFV) of dogs which is used to measure the solubility has not been quantified in vivo. The aim of the work is to measure the GFV using magnetic resonance imaging (MRI) from 12 Beagle dogs weighing 9–12 kg (6 male and 6 female). We found that the average GFV within this weight range was 24.0 ± 4.2 mL. The result can be used for the BCS studies of canine drugs and also serves as a reference for other species.
Electrical stimulation with motility analysis of five parts of the gastrointestinal tract ; First evaluation of an experimental protocol in a porcine…
2018
Abstract Gastrointestinal (GI) motility disorders are frequent and clinically significant conditions with impairment of patient’s quality of life. Examples range from upper GI symptoms such as dysphagia and gastroparesis to lower GI manifestations, namely chronic-intestinal pseudo obstruction, diarrhea and constipation. Furthermore, postoperative motility disorders are common. Currently, available pharmacological or dietetic treatment options are limited. Since GI motility is based on myoelectric activity, electrical stimulation (ES) is a promising alternative. Numerous studies have demonstrated suitable pacing strategies and parameters in different GI segments. However, results of multiloc…
Photo-thermal effects in gold nanorods/DNA complexes
2015
An ingenious combination of plasmonic nanomaterials and one of the most relevant biological systems, deoxyribonucleic acid (DNA) is achieved by bioconjugating gold nanorods (GNRs) with DNA via electrostatic interaction between positively charged GNRs and negatively charged short DNA. The obtained system is investigated as a function of DNA concentration by means of gel electrophoresis, zeta-potential, DNA melting and morphological analysis. It turns out that the obtained bioconjugated systems present both effective electric charge and aggregate size that are particularly amenable for gene therapy and nanomedicine applications. Finally, the effect of the localized (photo-thermal heating) and…
Lipid chaperones and associated diseases: a group of chaperonopathies defining a new nosological entity with implications for medical research and pr…
2020
AbstractFatty acid–binding proteins (FABPs) are lipid chaperones assisting in the trafficking of long-chain fatty acids with functions in various cell compartments, including oxidation, signaling, gene-transcription regulation, and storage. The various known FABP isoforms display distinctive tissue distribution, but some are active in more than one tissue. Quantitative and/or qualitative changes of FABPs are associated with pathological conditions. Increased circulating levels of FABPs are biomarkers of disorders such as obesity, insulin resistance, cardiovascular disease, and cancer. Deregulated expression and malfunction of FABPs can result from genetic alterations or posttranslational mo…