Flipped Classroom Approach of Teaching Chemistry in Higher Education

The flipping classroom method has been increasing steadily in acceptance and approval worldwide. In fact, there is a global agreement on the benefits of flipping courses at all levels and different majors. This approach has been largely adopted, specifically at the level of higher education. Our findings revealed an amelioration of the mean student’s success percentage with the use of Edmodo and Moodle during the environmental chemistry course taught with the flipped approach. This paper reviews the flipped classroom method as an advantageous active learning method and counsels its combination with modern information and communication technology (ICT) for better profit as well

Application of response surface methodology in the design of functionally graded plasma sprayed hydroxyapatite coatings

The highly complex process-property-structure relationship poses a major challenge in the optimization of plasma sprayed hydroxyapatite coatings. In addition, contradictions in relation to the ideal coating properties exist; a dense, highly crystalline coating is required for long term coating stability, whereas coatings with lower crystallinity dissolve more rapidly but have an improved osteogenic response in vivo. In this study, response surface methodology (RSM) is utilized to investigate the influences and interaction effects of current, gas flow rate, powder feed rate, spray distance and carrier gas flow rate on the roughness, crystallinity, purity, porosity and thickness of plasma sprayed HA coatings. Roughness related to the particle velocity and particle melting, and was highest at low gas flow rates and, due to the quadratic effect of current, at the central current value. High crystallinity resulted at high current and low spray distance due to the presence of bulk crystalline material and recrystallization of amorphous material. Purity was highest at low carrier gas flow rate and high gas flow rate, where particle temperature was reduced. Porosity was dependent on the degree of particle melting and was highest at low gas flow rate and powder feed rate and at high current and spray distance. Coating thickness was determined by the number of particles and the degree of flattening on impact, and was highest at high current, low gas flow rate, high powder feed rate and low spray distance. From this in-depth analysis, predictive process equations were developed and optimized to produce two distinct coatings; a stable coating and a bioactive coating, designed to form the base and surface layers of a functionally graded coating respectively, to provide enhanced osteogenesis, while maintaining long-term stability. Culture of osteoblast-like cells on the coatings demonstrated an increased osteogenic response on the bioactive coating compared to the other groups. Overall, this study identifies parameter effects and interactions leading to the development of optimized coatings with the potential to enhance the functional life of HA coated implants in vivo

Expression of Toll-like Receptor 9 Increases with Progression of Cervical Neoplasia in Tunisian Women - A Comparative Analysis of Condyloma, Cervical Intraepithelial Neoplasia and Invasive Carcinoma

International audienceToll-like receptors (TLRs) are expressed in immune and tumor cells and recognize pathogen-associated molecular patterns. Cervical cancer (CC) is directly linked to a persistent infection with high risk human papillomaviruses (HR-HPVs) and could be associated with alteration of TLRs expression. TLR9 plays a key role in the recognition of DNA viruses and better understanding of this signaling pathway in CC could lead to the development of novel immunotherapeutic approaches. The present study was undertaken to determine the level of TLR9 expression in cervical neoplasias from Tunisian women with 53 formalin-fixed and paraffin-embedded specimens, including 22 samples of invasive cervical carcinoma (ICC), 18 of cervical intraepithelial neoplasia (CIN), 7 of condyloma and 6 normal cervical tissues as control cases. Quantification of TLR9 expression was based on scoring four degrees of extent and intensity of immunostaining in squamous epithelial cells. TLR9 expression gradually increased from CIN1 (80% weak intensity) to CIN2 (83.3% moderate), CIN3 (57.1% strong) and ICC (100% very strong). It was absent in normal cervical tissue and weak in 71.4% of condyloma. The mean scores of TLR9 expression were compared using the Kruskall-Wallis test and there was a statistical significance between normal tissue and condyloma as well as between condyloma, CINs and ICC. These results suggest that TLR9 may play a role in progression of cervical neoplasia in Tunisian patients and could represent a useful biomarker for malignant transformation of cervical squamous cells

Implementation of autonomous navigation and mapping using a laser line scanner on a tactical unmanned aerial vehicle

The objective of this thesis is to investigate greater levels of autonomy in unmanned vehicles. This is accomplished by reviewing past literature about the developing of components of software architecture that are necessary for unmanned systems to achieve greater autonomy. The thesis presents implementation studies of existing sensor-based robotic navigation and mapping algorithms in both software and hardware, including a laser range finder, on a quadrotor unmanned aerial vehicle platform for real-time obstacle detection and avoidance. This effort is intended to lay the groundwork to begin critical evaluation of the strengths and weaknesses of the MOOS-IVP autonomy architecture and provide insight into what is necessary to achieve greater levels of intelligent autonomy in current and future unmanned systems.http://archive.org/details/implementationof1094510728Tunisian Army autho

Acylation des flavonoïdes par la lipase de candida antarctica (influence du donneur d'acyle sur la sélectivité et la cinétique de biotransformation)

L'objectif général de ce travail est l'étude et l'optimisation des réactions de synthèse enzymatique de nouveaux esters de flavonoide. Ce travail a été réalisé en présence de la lipase immobilisée de Candida antarctica et dans un milieu organique à faible teneur en eau (<300 ppm). Dans une première étape, une étude préliminaire des paramètres clef de la réaction a montré que la transestérification est moins performante que l'estérification directe car l'hydrolyse du donneur d'acyle prédomine la synthèse d'ester de flavonoide. La quantité d'eau du milieu présente au cours de la synthèse joue un rôle essentiel. Elle provoque un déplacement de l'équilibre vers l'hydrolyse, ce qui conduit à une diminution du rendement. Parmi les différents solvants testés, le méthyl-2-butanol 2 donne les meilleurs résultats. L'étude de l'effet de structure du donneur d'alcool et d'acyle sur la performance d'acylation montre que les meilleures vitesses initiales et rendements de conversion ont été obtenus avec la rutine (71 %, 3.1 [mu]mole.h-1) et l'estuline (80%,8. 7 [mu]mole.h-1) et les acides gras ayant une chaîne carbonée supérieure à C12 (87%, 15 [mu]mole.h-1). L'acylation des flavonoides mène uniquement à de monoesters et l'acylation a lieu au niveau du 6"-OH primaire de l'egcutine etdu 4"'-OH secondaire de la rutine. Cette étude a montré aussi que la synthèse d'ester aromatique de flavonoïde est faisable et le rendement d'acylation peut atteindre 75%. Une optimisation par la méthode de plan d'expériences a montré que la vitesse initiale de conversion et la séléctivité de la réaction dépend de la nature du solvant et des concentrations initiales des substratsThe general objective of this work is to study and to optimise the enzymatic synthesis of new esters of tlavonoide. Immobilized lipase of Candida antarctica was used as biocatalyst in an organic medium with low waler content (< 300 ppm). The obtained results showed that trans-esterification is less performant than direct esterification due to the fact that the hydrolytic reaction is predominant compared to the flavonoids ester synthesis. The water content of the medium along the time course of the reaction plays an essential role. Even if at a low level It provokes a drastic decrease of the conversion yield. Among, the various sol vents tested methyl- 2-butanol 2 gives the best results. The study of the effect of structure of the donors of alcohol and acyl on the performance of acylation shown that best initial rates and conversion yields were obtained with rutin (71 %, 3.1.[mu]ole.h-1 and the esculin (80%, 8.7 [mu]ole.h-1) in the presence of fatty acids with carbon chain higher than C12 (87%, 15 [mu]ole.h-1). The acylation of the flavonoides leads only to monoesters and the it takes place on the primary 6''-OH of the esculin and secondary 4''-OH of rotin. This study showed also that the aromatic ester synthesis of flavonoide is feasible and the conversion yield of this acylation can reach in some cases 75 %. The use of an experimental design showed that the initial rates of substrates conversion and the selectivity of the reaction depends on the nature ofsolvent and the initial concentrations of the substratesNANCY/VANDOEUVRE-INPL (545472102) / SudocSudocFranceF