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Diastereoselective Synthesis of Perfluoroalkylmethyl‐Substituted 1,2,3,4‐Tetrahydroquinolines Derivatives through 1‐Iodo‐1,3‐bis(acetoxy) Synthons
No full textInternational audienceNovel 2-perfluoroalkylmethyl,4-arylamino substituted tetrahydroquinolines (THQ) were expeditiously synthesized from perfluoroalkyl iodides RF–I and monosubstituted anilines. First, radical bis-addition of vinylacetate on RF–I afforded gem-iodoacetoxy derivatives (newly characterized by NMR and MS) being actually masked/activated aldol synthons. Their reaction in 1:4 ratio with arylamines afforded title THQ under mild conditions in good yields (60–95%) and diastereoselectivities (65:35 – 95:5 cis/trans isomer ratio); m-substituted anilines regiospecifically lead to 7-substituted THQ. Mechanistic investigation suggested the THQ formation to proceed through Michael then imine addition of two aniline units on an RF-substituted crotonaldehyde intermediate; then through the cyclization of the resulting bis(arylamino/imino) intermediate through electrophillic aromatic substitution. Various RF (C6, C2, C4) and arylamine substitutions (p-,o-,m- alkyl, alkoxyl, halogen…) were thus exemplified
Energy-Efficient Uplink Scheduling in Narrowband IoT
No full textInternational audienceThis paper presents a detailed study of uplink scheduling in narrowband internet of things (NB-IoT) networks. As NB-IoT devices need a long battery lifetime, we aim to maximize energy efficiency while satisfying the main requirements for NB-IoT devices. Also, as the NB-IoT scheduling problem is divided into link adaptation problem and resource allocation problem, this paper investigates the correlation between these two problems. Accordingly, we propose two scheduling schemes: the joint scheduling scheme, where the two problems are combined as one optimization problem, and the successive scheduling scheme that manages each problem separately but successively. Each scheme aims to maximize energy efficiency while achieving reliable transmission, satisfying delay requirements, and guaranteeing resource allocation specifications. Also, we investigate the impact of the selected devices to be served on the total energy efficiency. Accordingly, we propose two device selection techniques to maximize the total energy efficiency. The first technique exhaustively searches for the optimal devices, while the second sorts the devices based on a proposed priority score. The simulation results compare the successive and the joint scheduling schemes. The results show that the joint scheme outperforms the successive scheme in terms of energy efficiency and the number of served devices but with higher complexity. Also, the results highlight the impact of each proposed selection technique on the scheduling schemes’ performance
Effect of Intraoral Humidity on Dentin Bond Strength of Two Universal Adhesives: An In Vitro Preliminary Study
No full textAbstract: This study investigated the effect of intraoral humidity on microtensile bond strength (µTBS) to dentin of two universal adhesives applied in self-etch (SE) mode. Forty extracted human molars were selected for this study. Dentin specimens were allocated into four groups, standardized and then bonded with two commercial multimode adhesives, according to two humidity conditions (50% relative humidity (RH) and 90% RH). Following composite resin build-up and 24 h of water storage, the µTBS of the bonded interface was analyzed. The 50% RH was higher for Scotchbond Universal (SBU) than Prime&Bond Universal (PBU), while for 90% RH, SBU had significantly lower values than PBU. With PBU, the mean bond strength was not significantly different between both humidity settings tested (p > 0.05), while for SBU, the mean bond strength was significantly different between both conditions tested (p < 0.05); µTBS was significantly higher for 50% RH than for the other group. Within the limitation of this in vitro study, it can be concluded that: 1) the bonding performance of adhesives systems depends on the humidity settings; 2) increased RH exerts a detrimental effect on the bond strength of 2-hydroxyethyl methacrylate (HEMA)-containing adhesive tested. However, this phenomenon was not observed for HEMA-free adhesive tested; 3) further research in this area is needed to investigate different adhesive systems, temperatures and humidity settings
A Hybridized Mixed Approach for Efficient Stress Prediction in a Layerwise Plate Model
No full textInternational audienceBuilding upon recent works devoted to the development of a stress-based layerwise model for multilayered plates, we explore an alternative finite-element discretization to the conventional displacement-based finite-element method. We rely on a mixed finite-element approach where both stresses and displacements are interpolated. Since conforming stress-based finite-elements ensuring traction continuity are difficult to construct, we consider a hybridization strategy in which traction continuity is relaxed by the introduction of an additional displacement-like Lagrange multiplier defined on the element facets. Such a strategy offers the advantage of uncoupling many degrees of freedom so that static condensation can be performed at the element level, yielding a much smaller final system to solve. Illustrative applications demonstrate that the proposed mixed approach is free from any shear-locking in the thin plate limit and is more accurate than a displacement approach for the same number of degrees of freedom. As a result, this method can be used to capture efficiently strong intra- and inter-laminar stress variations near free-edges or cracks
La Finance Décentralisée et ses Solutions Mondiales Innovantes - Le Secteur de l'Assurance et l’Interruption des Activités pendant la Pandémie du Covid-19
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The Large and Diverse Family of Mediterranean Flat Breads: A Database
No full textInternational audienceAn in-depth survey was conducted by collecting information from web sources, supplemented by interviews with experts and/or bakers, to identify all the flat breads (FBs) produced in the nine Mediterranean countries involved in the FlatBreadMine Project (Croatia, Egypt, France, Greece, Italy, Jordan, Lebanon, Malta and Spain), and to have an insight into their technical and cultural features. A database with information on 143 FB types (51 single-layered, 15 double-layered, 66 garnished, 11 fried) was established. Flours were from soft wheat (67.4%), durum wheat (13.7%), corn (8.6%), rye, sorghum, chickpea, and chestnut (together 5.2%). The raising agents were compressed yeast (55.8%), sourdough (16.7%), baking powder (9.0%), but 18.6% of FBs were unleavened. Sixteen old-style baking systems were recorded, classified into baking plates and vertical ovens (tannur and tabun). Artisanal FBs accounted for 82%, while the industrial ones for 7%. Quality schemes (national, European or global) applied to 91 FBs. Fifteen FBs were rare, prepared only for family consumption: changes in lifestyle and increasing urbanization may cause their disappearance. Actions are needed to prevent the reduction of biodiversity related to FBs. Information in the database will be useful for the selection of FBs suitable to promotional activities and technical or nutritional improvement
Spine slenderness is not an early sign of progression in adolescent idiopathic scoliosis
No full textInternational audienceAdolescent idiopathic scoliosis (AIS) is a three-dimensional deformity of the spine. Spine slenderness, which represents its potential instability to buckling under compressive loads, was shown to be higher in AIS patients than non-scoliotic subjects, but it is not clear at what stage of the progression this difference appeared, nor if slenderness could be used as an early sign of progression. In this study, we hypothesized that slenderness could be an early sign of progression.One-hundred thirty-eight patients and 93 non-scoliotic subjects were included. They underwent standing biplanar radiography and 3D reconstruction of the spine, which allowed computing vertebra and disc slenderness ratio. Then, patients were followed until progression of the deformity or skeletal maturity (stable patients).Vertebral slenderness ratio in AIS patients varied between 2.9 [2.7; 3.0] (T9) and 3.4 [3.2; 3.6] (T1), while disc slenderness ranged from 0.6 [0.6; 0.7] at T6-T7 to 1.2 [1.1; 1.3] at L4-L5. Slenderness ratio increased with age, while disc slenderness tended to decrease with age and Cobb angle. Slenderness was similar between progressive and stable patients, and also between patients and non-scoliotic subjects.In conclusion, spinal slenderness does not appear to be an early sign of progression. Further studies should analyse the development of slenderness during growth, and how it could be affected by non-operative treatment
Parenting Culture(s): Ideal-Parent Beliefs Across 37 Countries
No full textInternational audienceWhat is it to be “an ideal parent”? Does the answer differ across countries and social classes? To answer these questions in a way that minimizes bias and ethnocentrism, we used open-ended questions to explore ideal-parent beliefs among 8,357 mothers and 3,517 fathers from 37 countries. Leximancer Semantic Network Analysis was utilized to first determine parenting culture zones (i.e., countries with shared ideal-parent beliefs) and then extract the predominant themes and concepts in each culture zone. The results yielded specific types of ideal-parent beliefs in five parenting culture zones: being “responsible and children/family-focused” for Asian parents, being “responsible and proper demeanor-focused” for African parents, and being “loving and responsible” for Hispanic-Italian parents. Although the most important themes and concepts were the same in the final two zones—being “loving and patient,” there were subtle differences: English-speaking, European Union, and Russian parents emphasized “being caring,” while French-speaking parents valued “listening” or being “present.” Ideal-parent beliefs also differed by education levels within culture zones, but no general pattern was discerned across culture zones. These findings suggest that the country in which parents were born cannot fully explain their differences in ideal-parent beliefs and that differences arising from social class or education level cannot be dismissed. Future research should consider how these differences affect the validity of the measurements in question and how they can be incorporated into parenting intervention research within and across cultures
Gender Equality and Maternal Burnout: A 40-Country Study
No full textInternational audienceIn Western countries, recent decades have witnessed a revolution toward gender equality. Inequalities have been greatly reduced in areas such as education or employment. Because inequalities lead to distress, this development has largely benefited women. One notable exception is the realm of parenting, which has remained rife with inequalities even in the most egalitarian countries. We hypothesized that experiencing inequality in parenting when one holds egalitarian values and raising a child in a country characterized by a high level of gender equality in other areas, increases mothers’ psychological distress in the specific area of parenting. Multilevel modeling analyses computed among 11,538 mothers from 40 countries confirmed this prediction: high egalitarian values at the individual level and high gender equality at the societal level are associated with higher burnout levels in mothers. The associations hold beyond differences in sociodemographic characteristics at the individual level and beyond economic disparities at the societal level. These findings show the importance of egalitarian values and gender equality and their paradoxical effect when inequalities are still present in specific areas as parenting. This study reveals the crucial need to act not only at the micro level but also at the macro level to promote gender equality in parenting and prevent parental burnout