Vascular Smooth Muscle Cells (VSMCs) in Blood Vessel Tissue Engineering: The Use of Differentiated Cells or Stem Cells as VSMC Precursors

Vascular smooth muscle cells (VSMCs) play important roles in the physiology and pathophysiology of the blood vessels. In a healthy adult organism, VSMCs are quiescent, but after a blood vessel injury, they undergo phenotypic modulation from the contractile phenotype to the synthetic phenotype, characterized by high activity in migration, proliferation and proteosynthesis. This behavior of VSMCs can lead to stenosis or obliteration of the vascular lumen. For this reason, VSMCs have tended to be avoided in the construction of blood vessel replacements. However, VSMCs are a physiological and the most numerous component of blood vessels, so their presence in novel advanced vascular replacements is indispensable. Either differentiated VSMCs or stem cells as precursors of VSMCs can be used in the reconstruction of the tunica media in these replacements. VSMCs can be obtained from blood vessels (usually from subcutaneous veins) taken surgically from the patients and can be expanded in vitro. During in vitro cultivation, VSMCs lose their differentiation markers, at least partly. These cells should therefore be re-differentiated by seeding them on appropriate scaffolds by composing cell culture media and by mechanical stimulation in dynamic bioreactors. Similar approaches can also be applied for differentiating stem cells, particularly adipose tissue-derived stem cells, toward VSMCs for the purposes of vascular tissue engineering

Manufacturing and properties of biobased thermoplastic composites from poly(lactid acid) and hazelnut shell wastes

This is the peer reviewed version of the following article: Balart, J.F., Garcia-Sanoguera, David, Balart, Rafael, Boronat, Teodomiro, Sanchez-Nacher, Lourdes. (2018). Manufacturing and properties of biobased thermoplastic composites from poly(lactid acid) and hazelnut shell wastes.Polymer Composites, 39, 3, 848-857. DOI: 10.1002/pc.24007 , which has been published in final form at [Link to final article using the DOI]. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.[EN] Poly(lactic acid), PLA-based green composites were obtained with hazelnut shell flour (HSF) derived from the food industry thus leading to fully biodegradable materials with attracting properties. The hazelnut shell flour content varied in the 10-40wt% range. An increase in the degree of crystallinity with increasing HSF was detected, mainly due to the nucleating effect of lignocellulosic particles. The thermodimensional stability was noticeably improved with increasing HSF amount as evidenced by a remarkable decrease in the coefficient of thermal-linear expansion. Increasing HSF leads to stiffer materials as HSF particles act as interlock points that restrict polymer chain motion. Addition of hazelnut shell flour as filler in PLA-based green composites leads to fully biodegradable composites with balanced mechanical and thermal properties. Furthermore, it gives a solution to upgrade wastes from the hazelnut industry and contributes to lower the cost of PLA-based materials. POLYM. COMPOS., 39:848-857, 2018. (c) 2016 Society of Plastics EngineersContract grant sponsor: Ministerio de Economia y Competitividad-MINECO; contract grant number: MAT2014-59242-C2-1-R; contract grant sponsor: Conselleria d'Educacio, Cultura i Esport; contract grant number: GV/2014/008.Balart, J.; Garcia-Sanoguera, D.; Balart, R.; Boronat, T.; Sanchez-Nacher, L. (2018). Manufacturing and properties of biobased thermoplastic composites from poly(lactid acid) and hazelnut shell wastes. Polymer Composites. 39(3):848-857. doi:10.1002/pc.24007S84885739

A comprehensive overview of radioguided surgery using gamma detection probe technology

The concept of radioguided surgery, which was first developed some 60 years ago, involves the use of a radiation detection probe system for the intraoperative detection of radionuclides. The use of gamma detection probe technology in radioguided surgery has tremendously expanded and has evolved into what is now considered an established discipline within the practice of surgery, revolutionizing the surgical management of many malignancies, including breast cancer, melanoma, and colorectal cancer, as well as the surgical management of parathyroid disease. The impact of radioguided surgery on the surgical management of cancer patients includes providing vital and real-time information to the surgeon regarding the location and extent of disease, as well as regarding the assessment of surgical resection margins. Additionally, it has allowed the surgeon to minimize the surgical invasiveness of many diagnostic and therapeutic procedures, while still maintaining maximum benefit to the cancer patient. In the current review, we have attempted to comprehensively evaluate the history, technical aspects, and clinical applications of radioguided surgery using gamma detection probe technology

Expertises des centres d'enfouissement des déchets urbains dans les PED (contributions à l'élaboration d'un guide méthodologique et à sa validation expérimentale sur sites)

Ce travail de recherche a permis d élaborer des outils d expertise, de définir des paramètres analytiques de caractérisation des déchets et des paramètres spécifiques de suivi de l évolution du massif de déchets dans les pays en développement (PED). Ces outils constituent un guide qui se décline en deux parties : une partie organisation de suivi et une deuxième partie consacrée au protocole expérimental de suivi et peut être adapté selon les situations. Ce guide d expertise permet de définir les conditions minimales d enfouissement des déchets ménagers dans les PED, afin de limiter les impacts environnementaux. La méthodologie s appuie sur des dysfonctionnements rencontrés dans ces pays, sur des questionnaires types et sur des mesures de paramètres pertinents capables de renseigner sur les déchets et l évolution du massif. Trois expertises ont permis de valider le guide. La première est réalisée sur le site de Polesgo au Burkina Faso (en démarrage), la deuxième sur le site de Ouled Fayet en Algérie (en exploitation) et la troisième sur un site d enfouissement de type décharge sèche à Saaba au Burkina Faso (en fin d exploitation).This research permitted to work out tools for expertise, to define analytical parameters of waste characterization and specific parameters to follow-up of the evolution of the municipal solid waste in the landfill; it also allow us to settle an experimental guide of expertise for hiding waste s center in the developing countries. This guide includes an organization part of follow-up and a second part is consecrate to the experimental protocol of follow-up, which can be adapted according to situations'. This guide of expertise permits to define the minimal conditions of hiding domestic waste in the developing countries, in order to limit the environmental impacts. The methodology is based on dysfunctions met in these countries, on standard questionnaires and measurements of pertinents parameters able to inform about waste. Three expertises made possible to validate the guide. The first one, realized the site of Polesgo in Burkina Faso (in starting), the second one, on the site of Ouled Fayet in Algeria (in exploitation) and the third one, on a site of hiding of the type entombment or dry tomb in Saaba in Burkina Faso (at the end of the exploitation).LIMOGES-BU Sciences (870852109) / SudocSudocFranceF

Assessment of Respiratory System Resistance during High-Frequency Oscillatory Ventilation Based on In Vitro Experiment

High-frequency oscillatory ventilation (HFOV) is a type of mechanical ventilation with a protective potential characterized by a small tidal volume. Unfortunately, HFOV has limited monitoring of ventilation parameters and mechanical parameters of the respiratory system, which makes it difficult to adjust the continuous distension pressure (CDP) according to the individual patient’s airway status. Airway resistance Raw is one of the important parameters describing the mechanics of the respiratory system. The aim of the presented study was to verify in vitro whether the resistance of the respiratory system Rrs can be reliably determined during HFOV to evaluate Raw in pediatric and adult patients. An experiment was performed with a 3100B high-frequency oscillator, a physical model of the respiratory system, and a pressure and flow measurement system. The physical model with different combinations of resistance and compliance was ventilated during the experiment. The resistance Rrs was calculated from the impedance of the physical model, which was determined from the spectral density of the pressure at airway opening and the spectral cross-density of the gas flow and pressure at airway opening. Rrs of the model increased with an added resistor and did not change significantly with a change in compliance. The method is feasible for monitoring respiratory system resistance during HFOV and has the potential to optimize CDP settings during HFOV in clinical practice

Caractérisation physico-chimique de l'état de dégradation de déchets stockés dans une décharge sèche (zone semi-aride) : site expérimental de Saaba (Burkina Faso)

International audienceLes pratiques de gestion et de stockage des déchets sont un des problèmes majeurs des municipalités des pays en développement (PED). Il apparait nécessaire de ne plus seulement limiter les risques actuels de pollution, mais aussi d'intégrer la notion de l'exploitation, du temps, du comportement et de l'évolution des déchets sur le long terme en tenant compte des particularités locales.Ce travail a été réalisé dans un PED, dans le cadre d'un projet de l'Agence de l'environnement et de la maitrise de l'énergie (ADEME) intitule : « Etude des conditions minimales de stockage des déchets dans les PED pour limiter les impacts environnementaux ».L'objectif de cette étude est le suivi de la dégradation des déchets d'une décharge en zone semi-aride à longue saison sèche, par la caractérisation physique et chimique des déchets stockes depuis 2002 suivant des paramètres simples facilement mesurables dans les PED