Screening phytochimique et identification spectroscopique des flavonoïdes d’Asteriscusgraveolenssubsp. odorus

Ce travail s’intéresse à l’étude phytochimique d’une espèce du Sud du Maroc appartenant à la famille des Asteraceae : Asteriscusgraveolenssubsp. odorus. Le screening phytochimique des feuilles et des fleurs de cette plante, effectuée pour la première fois, a révélé la présence des alcaloïdes, des flavonoïdes, des tanins catéchiques, des terpènes, des coumarines et des composés cyanogénétiques. Quant aux saponines et les quinones libres, ils sont présents chez les fleurs et absents chez les feuilles. La caractérisation des molécules par spectrophotométrie UV a révélé la présence de l’acide caféique, névadensine, lutéoline et artemétine dans les feuilles d’Asteriscus graveolens subsp. odorus.Mots-clés : analyse spectrophotométrique, screening phytochimique, asteriscus graveolens subsp. odorus

Multi-Objective Optimization of Demand Side Management and Multi DG in the Distribution System with Demand Response

The optimal management of distributed generation (DG) enhances the efficiency of the distribution system; On the other hand, increasing the interest of customers in optimizing their consumption improves the performance of DG. This act is called demand side management. In this study, a new method based on the intelligent algorithm is proposed to optimal operate the demand side management in the presence of DG units and demand response. Firstly, the best location and capacity of different technologies of DG are selected by optimizing the technical index including the active and reactive loss and the voltage profile. Secondly, the daily performance of multi-DG and grid is optimized with and without considering the demand response. The economic and environmental indices are optimized in this step. In both steps, the non-dominated sorting firefly algorithm is utilized to multi-objective optimize the objective functions and then the fuzzy decision-making method is used to select the best result from the Pareto optimal solutions. Finally, the proposed method is implemented on the IEEE 33-bus distribution system and actual 101-bus distribution systems in Khoy-Iran. The obtained numerical results indicate the impact of the proposed method on improving the technical, economic and environmental indices of the distribution system

SWPT: An automated GIS-based tool for prioritization of sub-watersheds based on morphometric and topo-hydrological factors

© 2019 China University of Geosciences (Beijing) and Peking University The sub-watershed prioritization is the ranking of different areas of a river basin according to their need to proper planning and management of soil and water resources. Decision makers should optimally allocate the investments to critical sub-watersheds in an economically effective and technically efficient manner. Hence, this study aimed at developing a user-friendly geographic information system (GIS) tool, Sub-Watershed Prioritization Tool (SWPT), using the Python programming language to decrease any possible uncertainty. It used geospatial–statistical techniques for analyzing morphometric and topo-hydrological factors and automatically identifying critical and priority sub-watersheds. In order to assess the capability and reliability of the SWPT tool, it was successfully applied in a watershed in the Golestan Province, Northern Iran. Historical records of flood and landslide events indicated that the SWPT correctly recognized critical sub-watersheds. It provided a cost-effective approach for prioritization of sub-watersheds. Therefore, the SWPT is practically applicable and replicable to other regions where gauge data is not available for each sub-watershed

Using fibrincollagen composite hydrogel and silk for bio-inspired design of tympanic membrane grafts: a vibro-acoustic analysis

Tympanic membrane (TM) is vulnerable to a variety of middle ear diseases. In some cases, reconstruction or repair of the TM is essential for recovering the hearing. Although there are many kinds of materials and therapeutics for TM reconstruction, tissue engineering of the TM is still in its initial steps of advancement. Treatment of damaged TM is usually carried out by otology-related techniques such as myringoplasty and tympanoplasty. Most of the novel tympanoplasty methods employ artificial grafts made of biomaterials and polymers for scaffolds. One biomaterial candidate for design and fabrication of synthetic grafts is spider silk, which has excellent mechanical and acoustic characteristics. On the other hand, the structural function of the spider web is also one of the potential inspirations for designing tissue-engineered grafts on micro-scale explorations. In this study, a bio-inspired design and analysis of silky TM grafts are carried out employing finite element modeling and vibro-acoustic investigation. A comparative and statistical analysis is also performed with experimentally validated data to check the suitability of the materials and design. The numerical study shows that the proposed bio-inspired models are appropriate for TM graft design and fabrication. The effects of inspired architecture and materials on obtaining an optimum design for TM grafts are put into evidence via a parametric study, and pertinent conclusions are outlined

Unusual secondary metabolites of the aerial parts of dionysia diapensifolia bioss. (primulaceae) and their anti-inflammatory activity

The genus Dionysia, belonging to the Primulaceae family, encompasses more than 50 species worldwide with a center of diversity located in the arid Irano-Turanian mountains. In this study, a phytochemical investigation of the aerial parts of D. diapensifolia Bioss. led to the isolation of 24 phenolic compounds 1–7 and 9–25, and one sesquiterpenoid 8. Compound 1 was identified as new natural product, while isolation of 2 and 3, already known as synthetic products, from a natural source is reported for the first time in the present study. Isolation of compound 8 from a Dionysia species and indeed the whole Primulaceae family is reported for the first time too. Structure elucidation was performed by extensive spectroscopic analyses (1D-, 2D-NMR, and MS), and by comparison with reported literature data. Furthermore, DP4+ chemical shift probability calculations were performed to establish the relative configuration of compound 1. Additionally, subfractions obtained by liquid-liquid extraction of the methanolic extract of the plant, and subsequently the isolated new and selected known compounds 1–4, 6, 8–11 obtained from the diethyl ether subfraction were investigated for their inhibitory effect on NO release and iNOS and COX-2 expression in J774A.1 murine macrophages. The results showed a potential anti-inflammatory activity of the obtained subfractions, of which the diethyl ether subfraction was the most active one in inhibiting NO release and COX-2 expression (p < 0.001). Among the investigated isolated compounds, compound 4 significantly (p < 0.001) inhibited NO release and iNOS and COX-2 expression in a comparable manner like the used positive controls (L-NAME and indomethacin, respectively). Moreover, other isolated substances displayed moderate to high inhibitory activities, illustrating the potential anti-inflammatory activity of Dionysia diapensifolia

Nonlinear vibration behaviors of dielectric elastomer membranes under multi-frequency excitations

Dielectric elastomers (DEs) are electromechanical systems that play an essential role in designing soft robotic actuators. Due to their flexibility and lightweight, DEs mainly operate in nonlinear regimes and experience nonlinear vibrations in various applications. One of the newly developed stimuli in these actuators is the pumping deformation action due to vibratory response of DEs caused by the sound generation. In this study the nonlinear vibration behavior of a DE membrane under a multi-frequency voltage and a multi-frequency lateral tensile mechanical load is fundamentally investigated. The governing equations of motion are derived using Euler—Lagrange’s equation and solved using the Runge-Kutta method. Numerical calculations are presented in the form of time-history diagrams, phase-plane diagrams, Poincaré sections, and in the frequency domain using fast Fourier transforms. Results reveal that both electrical and mechanical multi-frequency excitations can cause chaos, quasiperiodicity, and torus-doubling phenomena in the system. The multi-frequency excitation can control the effects of the damping in the system. Results also show that multi-frequency excitations may improve the performance of dielectric elastomers, where a higher response amplitude is required. Moreover, the multi-frequency voltage may diminish the required high voltage in dielectric elastomers by adding an extra AC voltage. Torus-doubling bifurcation is also identified, which originated from the application of multi-mode frequency. Results also show that applying two low amplitude AC voltages can achieve a large amplitude vibration response compared to a single frequency high amplitude voltage. The results presented in this paper can thus provide an essential guidance in designing dielectric elastomer membranes under large vibratory deformation with low voltage requirement

Experimentally validated vibro-acoustic modeling of 3D bio-printed grafts for potential use in human tympanic membrane regeneration

Three-dimensional (3D) bioprinting is a pioneering field of tissue engineering obtaining a special role in most medical engineering fields. Otology is a medicine branch that needs bioprinting technology to receive aids for the reconstruction of aesthetic necessities of the ear and treating hearing loss diseases due to several pathological reasons such as tympanic membrane (TM) perforation. In this work, computational dynamic simulations of 3D printed TM grafts are presented. The main purpose of numerical modeling of these experimentally validated composite scaffolds is to demonstrate the worth of simulation in shortening the design time and decreasing testing costs of biomedical engineering projects. The simulated 3D printed TM grafts were fabricated in two main architectural categories using three different polymeric materials of polydimethylsiloxanes (PDMS), flex polylactic acid (PLA), and polycaprolactone (PCL) with uniform infilling of fibrincollagen composite hydrogels. As a numerical and dynamic validation study, firstly, a finite element (FE) simulation of the artificial TM grafts is carried out for a vibro-acoustic analysis by the COMSOL Multiphysics software package. Then a comparative study of results obtained from the dynamic modeling is performed with a set of existing data taken from experimental validation test results from digital optoelectronic holography (DOEH) and laser Doppler vibrometry (LDV). Observations show a good correlation between the acoustic behaviors of in vitro tested 3D printed TM grafts and computational models in both frequency domain motion and normalized velocity patterns. Satisfying correlation between acoustic properties of simulated TM grafts and experimental test results shows potential applications of printed TM grafts in tympanoplasty

Keratopigmentation: a comprehensive review

Corneal keratopigmentation (KTP) has a long history of use in management of patients suffering from disfiguring corneal opacities. Due to progresses and modifications in KTP surgical techniques and its low rate of complications, it is taken into consideration to be used in selected groups of patients for therapeutic or functional indications. In this paper we present an overview on clinical applications of KTP in both cosmetic and functional aspects and also, we discuss the outcomes of KTP and its characteristics in experimental and histopathological studies. © 2020, The Author(s), under exclusive licence to The Royal College of Ophthalmologists

Six new triterpenoids from the root of Potentilla reptans and their cardioprotective effects in silico

Tormentic acid ester glucosides derivatives (1, 2 and 4), 3-oxoursane ester glycoside (3) and 11-methoxy-ursane ester glycosides (5, 6) as six new triterpenoids, along with catechin were isolated from the ethyl acetate fraction of Potentilla reptans root (Et) methanolic extract. The structures of the compounds were elucidated by 1D, 2D NMR, IR and MS spectroscopy. Additionally, isolated triterpenoid compounds (1�6) and catechin were evaluated for their cardioprotective effects via glycogen synthase kinase 3β (GSK-3β) and glucocorticoid regulated kinase-1 (SGK1) protein kinase inhibition by Molecular Docking. Compound 1 and catechin (compound 7) exhibited significant inhibitory effects against GSK-3β and SGK1 protein kinases with a binding energy value �9.1 and �8.8 kcal/mol, respectively. Hence, Et can be a suitable natural candidate to protect cardiomyocytes injury. © 2021 Informa UK Limited, trading as Taylor & Francis Group

Six new triterpenoids from the root of Potentilla reptans and their cardioprotective effects in silico

Tormentic acid ester glucosides derivatives (1, 2 and 4), 3-oxoursane ester glycoside (3) and 11-methoxy-ursane ester glycosides (5, 6) as six new triterpenoids, along with catechin were isolated from the ethyl acetate fraction of Potentilla reptans root (Et) methanolic extract. The structures of the compounds were elucidated by 1D, 2D NMR, IR and MS spectroscopy. Additionally, isolated triterpenoid compounds (1�6) and catechin were evaluated for their cardioprotective effects via glycogen synthase kinase 3β (GSK-3β) and glucocorticoid regulated kinase-1 (SGK1) protein kinase inhibition by Molecular Docking. Compound 1 and catechin (compound 7) exhibited significant inhibitory effects against GSK-3β and SGK1 protein kinases with a binding energy value �9.1 and �8.8 kcal/mol, respectively. Hence, Et can be a suitable natural candidate to protect cardiomyocytes injury. © 2021 Informa UK Limited, trading as Taylor & Francis Group