Biomedical Engineering

Biomedical engineering is currently relatively wide scientific area which has been constantly bringing innovations with an objective to support and improve all areas of medicine such as therapy, diagnostics and rehabilitation. It holds a strong position also in natural and biological sciences. In the terms of application, biomedical engineering is present at almost all technical universities where some of them are targeted for the research and development in this area. The presented book brings chosen outputs and results of research and development tasks, often supported by important world or European framework programs or grant agencies. The knowledge and findings from the area of biomaterials, bioelectronics, bioinformatics, biomedical devices and tools or computer support in the processes of diagnostics and therapy are defined in a way that they bring both basic information to a reader and also specific outputs with a possible further use in research and development

Aerospace Medicine and Biology: 1983 cumulative index

This publication is a cumulative index to the abstracts contained in the Supplements 242 through 253 of Aerospace Medicine and Biology: A Continuing Bibliography. It includes six indexes--subject, personal author, corporate source, contract number, report number, and accession number

Développement de nouvelles technologies pour le suivi en temps réel du comportement des chromosomes

L'organisation à grande échelle des chromosomes à l'intérieur du noyau des cellules est complexe et reste encore mal comprise. Durant ma thèse, nous avons exploité les ressources technologiques du LAAS pour développer et optimiser une nouvelle méthode de visualisation en 3D rapide - à l'échelle de la dizaine de millisecondes - avec une résolution spatiale de ~20 nanomètres. Cette méthode est fondée sur la fabrication de micromiroirs en forme de V par gravure humide du silicium, et sur l'analyse d'images avec les techniques de stéréovision qui permettent de recombiner des vues collectées sous différents angles dans un environnement 3D. Ces micromiroirs ont ensuite été intégrés dans un laboratoire sur puce, et plusieurs versions de la technologie ont été proposées afin d'améliorer leurs propriétés. Nous avons démontré que cette technologie est adaptée pour le suivi des mouvements des chromosomes dans les cellules vivantes, que nous avons pu retracer avec les meilleures cadences de la littérature. Ces résultats nous ont ensuite permis d'explorer les mécanismes physiques à l'origine des fluctuations spatiales des chromosomes, et de montrer que les modèles de physique des polymères génériques peuvent être utilisés pour extraire des informations quantitatives décrivant l'organisation et la dynamique spatiale du génome.Understanding the details of how chromatin folds and the physical parameters governing chromatin behavior are among the most intriguing intellectual challenges in modern cell biology. Recent insights on chromosome conformation in yeast nuclei were gained owing to high-throughput molecular biology techniques, but the physical parameters governing chromosomes dynamics remain completely misunderstood. During my thesis, we have developed an original high speed 3D imaging technology for studying chromatin in living yeast, which allows accessing 3D dynamics with temporal resolutions of 15 ms and nanometer resolution by fluorescence microscopy. Our technology is based on the fabrication of V-shaped micromirrors by standard photolithography, and relies on stereovision methods for 3D reconstruction. These micromirrors were integrated into a lab on a chip, and several versions of the technology have been proposed to improve their properties. We demonstrated that this technology is suitable for tracking the movement of chromosomes in living cells, and we achieved among the best acquisition rates in the literature. Our technological developments were eventually used to explore the physical mechanisms behind the spatial fluctuations of chromosomes, and we observed that standard models of polymer physics can be used to extract quantitative information describing the organization and the spatial dynamics of genome

PRELIMINARY FINDINGS OF A POTENZIATED PIEZOSURGERGICAL DEVICE AT THE RABBIT SKULL

The number of available ultrasonic osteotomes has remarkably increased. In vitro and in vivo studies have revealed differences between conventional osteotomes, such as rotating or sawing devices, and ultrasound-supported osteotomes (Piezosurgery®) regarding the micromorphology and roughness values of osteotomized bone surfaces. Objective: the present study compares the micro-morphologies and roughness values of osteotomized bone surfaces after the application of rotating and sawing devices, Piezosurgery Medical® and Piezosurgery Medical New Generation Powerful Handpiece. Methods: Fresh, standard-sized bony samples were taken from a rabbit skull using the following osteotomes: rotating and sawing devices, Piezosurgery Medical® and a Piezosurgery Medical New Generation Powerful Handpiece. The required duration of time for each osteotomy was recorded. Micromorphologies and roughness values to characterize the bone surfaces following the different osteotomy methods were described. The prepared surfaces were examined via light microscopy, environmental surface electron microscopy (ESEM), transmission electron microscopy (TEM), confocal laser scanning microscopy (CLSM) and atomic force microscopy. The selective cutting of mineralized tissues while preserving adjacent soft tissue (dura mater and nervous tissue) was studied. Bone necrosis of the osteotomy sites and the vitality of the osteocytes near the sectional plane were investigated, as well as the proportion of apoptosis or cell degeneration. Results and Conclusions: The potential positive effects on bone healing and reossification associated with different devices were evaluated and the comparative analysis among the different devices used was performed, in order to determine the best osteotomes to be employed during cranio-facial surgery

Proceedings of the 4th international conference on disability, virtual reality and associated technologies (ICDVRAT 2002)

The proceedings of the conferenc

[¹⁸F]fluorination of biorelevant arylboronic acid pinacol ester scaffolds synthesized by convergence techniques

Aim: The development of small molecules through convergent multicomponent reactions (MCR) has been boosted during the last decade due to the ability to synthesize, virtually without any side-products, numerous small drug-like molecules with several degrees of structural diversity.(1) The association of positron emission tomography (PET) labeling techniques in line with the “one-pot” development of biologically active compounds has the potential to become relevant not only for the evaluation and characterization of those MCR products through molecular imaging, but also to increase the library of radiotracers available. Therefore, since the [18F]fluorination of arylboronic acid pinacol ester derivatives tolerates electron-poor and electro-rich arenes and various functional groups,(2) the main goal of this research work was to achieve the 18F-radiolabeling of several different molecules synthesized through MCR. Materials and Methods: [18F]Fluorination of boronic acid pinacol esters was first extensively optimized using a benzaldehyde derivative in relation to the ideal amount of Cu(II) catalyst and precursor to be used, as well as the reaction solvent. Radiochemical conversion (RCC) yields were assessed by TLC-SG. The optimized radiolabeling conditions were subsequently applied to several structurally different MCR scaffolds comprising biologically relevant pharmacophores (e.g. β-lactam, morpholine, tetrazole, oxazole) that were synthesized to specifically contain a boronic acid pinacol ester group. Results: Radiolabeling with fluorine-18 was achieved with volumes (800 μl) and activities (≤ 2 GBq) compatible with most radiochemistry techniques and modules. In summary, an increase in the quantities of precursor or Cu(II) catalyst lead to higher conversion yields. An optimal amount of precursor (0.06 mmol) and Cu(OTf)2(py)4 (0.04 mmol) was defined for further reactions, with DMA being a preferential solvent over DMF. RCC yields from 15% to 76%, depending on the scaffold, were reproducibly achieved. Interestingly, it was noticed that the structure of the scaffolds, beyond the arylboronic acid, exerts some influence in the final RCC, with electron-withdrawing groups in the para position apparently enhancing the radiolabeling yield. Conclusion: The developed method with high RCC and reproducibility has the potential to be applied in line with MCR and also has a possibility to be incorporated in a later stage of this convergent “one-pot” synthesis strategy. Further studies are currently ongoing to apply this radiolabeling concept to fluorine-containing approved drugs whose boronic acid pinacol ester precursors can be synthesized through MCR (e.g. atorvastatin)