Search results for "Biomedical"

A granulometric analysis of specular microscopy images of human corneal endothelia

2005

The inner layer of the human cornea, called the corneal endothelium, plays an important role in the maintenance of corneal transparency. Specular microscopy is the most widely used technique to study the corneal endothelium in vivo. Improvements in technology have allowed us to obtain good quality specular images, but the detection and quantification of small size-shape cell changes is not obvious, specially when the physician wants to evaluate endothelial cell changes after some surgical procedures. This paper proposes a methodology to analyze specular microscopy images. Every corneal endothelium is described by means of different cumulative distribution functions or some moments (mean, st…

Digital holographic microscopy as a screening technology for diabetes

2019

Label-free quantitative phase imaging (QPI) is the hallmark of digital holographic microscopy (DHM). One of the most interesting medical applications of QPI-DHM is that it can be used to analyze illnesses in which the refractive index or/and the morphology of cells/tissues are distorted, from the acquisition of a single image. In this contribution, we obtain the phase maps of red blood cells (RBCs) samples of patients suffering from diabetes mellitus type 1 (DM1) by using a DHM. Our experimental results show that the measured phase values are significantly different between control non-diabetic and diabetic patients. The high correlation coefficient between the phase and the glycated hemogl…

Kognitive Prozesse und dynamische Zeitstrukturen. Vorstellung eines Meßgerätes zur Untersuchung der Mikro-Vigilanz-Shift-(MVS-)Hypothese. Cognitive P…

2003

The psychophysiological measuring method for the determination of the auditory order threshold (OT) is steadily gaining in importance, both for the diagnosis and treatment of speech disorders. Observed intraindividual variability of (macro-) vigilance led to the hypothesis of discontinuous cognitive processing in the central nervous system. The base for the variability of microvigilance is hypothesized to be in the phase difference of the alpha rhythm. To test for this hypothesis, we developed an EEG-comparator, which allows for a phase-dependent triggering of external stimuli. In direct comparison with stochastic (i.e. non-phase-dependent) stimulus presentation, the threshold in phase-depe…

Physiological Micromechanics of the Anterior Mitral Valve Leaflet

2011

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 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 could be imp…

Functionalization of Graphene with Molecules and/or Nanoparticles for Advanced Applications

2019

Graphene is considered the material of the third millennium, due to its extraordinary electronic and mechanical properties, and due to the possibility to modulate its conductivity, flexibility, elasticity, transparency, and biocompatibility by bottom-up approach. The possibility to gather the proper- ties of graphene and graphene oxide with those of functional moieties or nanoparticles is herein reviewed. The synthetic approaches proposed, either covalent or noncovalent, are aimed to tune appropriately graphene’s properties for the realization of materials for advanced uses, such as bio- medical applications, sensors, catalysis, and energy devices. In particular, methods based on covalent l…

Combined endoscopical treatments for tracheo‐esophageal fistula developed during V‐V ECMO for severe COVID‐19: A case series

2021

Fluorescent nanodiamonds encapsulated byCowpea Chlorotic Mottle Virus(CCMV) proteins for intracellular 3D-trajectory analysis

2021

Long-term tracking of nanoparticles to resolve intracellular structures and motions is essential to elucidate fundamental parameters as well as transport processes within living cells. Fluorescent nanodiamond (ND) emitters provide cell compatibility and very high photostability. However, high stability, biocompatibility, and cellular uptake of these fluorescent NDs under physiological conditions are required for intracellular applications. Herein, highly stable NDs encapsulated with Cowpea chlorotic mottle virus capsid proteins (ND-CP) are prepared. A thin capsid protein layer is obtained around the NDs, which imparts reactive groups and high colloidal stability, while retaining the opto-ma…

Psychometric properties of the French translation of the reduced KOOS and HOOS (KOOS-PS and HOOS-PS).

2009

Udgivelsesdato: 2009-Dec OBJECTIVE: To evaluate the psychometric properties of the French KOOS physical function (KOOS-PS) and HOOS physical function (HOOS-PS), specifically its feasibility, reliability, construct validity, and responsiveness. METHODS: Consecutive outpatients consulting for primary knee or hip osteoarthritis (OA) in a rheumatology department were included. During the initial assessment, patients were asked to complete the Knee injury and Osteoarthritis Outcome Score (KOOS) or Hip disability and Osteoarthritis Outcome Score (HOOS) questionnaire and the OsteoArthritis Knee and Hip Quality Of Life questionnaire (OAKHQOL). The patients were given a second KOOS or HOOS questionn…

A comparative study of mechanical properties of fresh and frozen-thawed porcine intervertebral discs in a bioreactor environment

2016

Abstract Limited availability of fresh intervertebral discs (IVDs) necessitates the use of frozen-thawed samples in biomechanical investigations. Several authors have reported the mechanical properties of frozen-thawed IVDs, but few studies have investigated the effects of storage temperature and cooling rate. The validity and reliability of the applied freezing-thawing procedures are still relatively unknown. The study aims to compare the mechanical responses of fresh porcine IVDs and porcine IVDs, which were frozen at different freezing temperatures with a controlled-rate cooling process and then thawed. The specimens were obtained from pigs aged 6 months. A total of 18 functional spine u…

Fabrication of quercetin and curcumin bionanovesicles for the prevention and rapid regeneration of full-thickness skin defects on mice

2013

In the present work biocompatible quercetin and curcumin nanovesicles were developed as a novel approach to prevent and restore skin tissue defects on chronic cutaneous pathologies. Stable and suitable quercetin- and curcumin-loaded phospholipid vesicles, namely liposomes and penetration enhancer-containing vesicles (PEVs), were prepared. Vesicles were made from a highly biocompatible mixture of phospholipids and alternatively a natural polyphenol, quercetin or curcumin. Liposomes were obtained by adding water, while PEVs by adding polyethylene glycol 400 and Oramix®CG110 to the water phase. Transmission electron microscopy, cryogenic-transmission electron microscopy and small- and wide-ang…