Hierarchical structure parameters in three dimensional turbulence: She-Leveque model

Imtiaz Ahmad,Lamjed Hadj-Taieb,Muzamal Hussain,Mohamed A. Khadimallah,Muhammad Taj,Adil Alshoaibi 국제구조공학회 2022 Smart Structures and Systems, An International Jou Vol.29 No.5

Hierarchical structure parameters, proposed in She-Leveque model, are investigated for velocity components obtained from different flow types over a large range of Reynolds numbers 255 < < 720. The values of intermittency parameter , with respect to a fixed velocity component, are observed nearly same for all four types of turbulence. The parameter , for streamwise velocity components is nearly the same but significantly different for vertical components in different flows. It is also observed that for both parameters, an obvious relation between the longitudinal and transverse components < (and < ) always holds. However, the difference between and is found very small in all types of turbulent flows, we studied here. It is evidenced that at low Reynolds numbers, the deviations from K41 scaling are mainly due to the most intense structures and slightly because of more heterogeneous hierarchy of fluctuation structures. However, at higher Reynolds numbers the deviations seem as a consequence of the most intense structures only. Over all, the study suggests that the hierarchy parameter may be consider as a universal constant.

Band Gap Engineering of Cs₃Bi₂I₉ Perovskites with Trivalent Atoms Using a Dual Metal Cation

Hong, Ki-Ha,Kim, Jongseob,Debbichi, Lamjed,Kim, Hyungjun,Im, Sang Hyuk American Chemical Society 2017 The Journal of Physical Chemistry Part C Vol.121 No.1

<P>Ternary metal halides (A(3)X(2)I(9)) have attracted considerable interest because they have good:stability and reduced toxicity compared with Pb-based halide perovskites. The main issue with A(3)X(2)I(9) is their band gap, which is relatively large for use in a single junction solar cell (1.9-2.2 eV for the Cs3Bi2I9). This theoretical study found that the band gap of Cs3Bi2I9 can be successfully modulated by using dual metal cations, i.e., by forming. Cs3Bi2I9 (X: trivalent cation). Among the various trivalent atoms, investigated, In and Ga showed very promising band gap modulation behaviors. Additionally, the indirect band gap of Cs3Bi2I9 can be changed into a direct nand gap.</P>

Hepatoprotective and Renoprotective Effects of Lavender (Lavandula stoechas L.) Essential Oils Against Malathion-Induced Oxidative Stress in Young Male Mice

Slimen Selmi,Manel Jallouli,Najoua Gharbi,Lamjed Marzouki 한국식품영양과학회 2015 Journal of medicinal food Vol.18 No.10

We aimed in the present study to investigate the hepato- and nephroprotective effects of Lavandula stoechas essential oils (LSEO) against malathion-induced oxidative stress in young male mice as well as the possible mechanism implicated in such protection. Animals were divided into eight groups of 12 each: Control, malathion (200 mg/kg b.w.); Various doses of LSEO (10, 30, and 50 mg/kg b.w.), malathion + various doses of LSEO. Malathion and LSEO were daily per orally (p.o.) administered by intragastric gavage during 30 days. We initially found that malathion treatment induced body weight gain decrease as well as a clear nephro- and hepatotoxicity as assessed by significant relative liver and kidney weight increase and related hemodynamic parameters deregulation. Malathion exposure of mice also induced a considerable perturbation of metabolic parameters. On the other hand, we showed that malathion administration was accompanied by an oxidative stress status assessed by an increase of malondialdehyde (MDA) and hydrogen peroxide (H2O2) levels as well as a depletion of sulfhydril group content (-SH) and antioxidant enzyme activities such as catalase (CAT) and glutathione peroxidase (GPx), total superoxide dismutase (SOD), Cu/Zn-SOD, Mn-SOD, and Fe-SOD in the kidney and liver. More importantly, LSEO treatment abolished all malathion-induced body gain loss, liver and kidney relative weight increase, hemodynamic and metabolic disorders, as well as hepatic and renal oxidative stress. In conclusion, our data suggest that LSEO exerted potential hepato- and nephroprotective effects against malathion-induced oxidative stress in mice. The beneficial effect of LSEO might be related, in part, to its antioxidant properties.

Combination effect of three anti-HSV-2 active plant extracts exhibiting different modes of action

Benzekri Roudaina,Limam Ferid,Bouslama Lamjed 경희대학교 융합한의과학연구소 2020 Oriental Pharmacy and Experimental Medicine Vol.20 No.2

The emergence of multidrug-resistant viruses leads to discover a novel source of drugs or a new strategy to overcome this obstacle. Combined herbal therapies are becoming a promising approach for a better efficiency. In this study, Pistacia lentiscus and Peganum harmala were investigated for their anti HSV-2 activity. Twenty eight organic extracts from different organs were evaluated for their cytotoxicity on Vero cells and their anti HSV-2 activity using the MTT test and the plaque reduction assay, respectively. Peganum harmala methanol seeds extract, Pistacia lentiscus methanol stem and dichloromethane fruit extracts were active on HSV-2 with selectivity index values of 13.19, 51.23 and 10.23, respectively. These active extracts exhibited different mode of action: (1) Peganum harmala methanol seeds extract showed a virucidal action before virus adsorption and penetration, and on the newly formed virions before their release outside infected cells—(2) Pistacia lentiscus methanol stem extract exhibited virucidal effect only before virus adsorption and penetration—(3) Pistacia lentiscus dichloromethane fruit extracts demonstrated virus inhibition up to 7 h post infection. The binary combination of the three active extracts did not improve their individually activity. This report could contribute to prove that combination of active extracts do not necessary increase the initial activity.

In Vitro Scolicidal Effects of Salvadora persica Root Extract against Protoscolices of Echinococcus granulosus

Abdel-Azeem S. Abdel-Baki,Esam Almalki,Lamjed Mansour,Saleh Al-Quarishy 대한기생충학열대의학회 2016 The Korean Journal of Parasitology Vol.54 No.1

Continuous element method for aeroacoustics' waves in confined ducts

Khadimallah, Mohamed A.,Harbaoui, Imene,Casimir, Jean B.,Taieb, Lamjed H.,Hussain, Muzamal,Tounsi, Abdelouahed Techno-Press 2022 Advances in nano research Vol.13 No.4

The continuous elements method, also known as the dynamic stiffness method, is effective for solving structural dynamics problems, especially over a large frequency range. Before applying this method to fluid-structure interactions, it is advisable to check its validity for pure acoustics, without considering the different coupling parameters. This paper describes a procedure for taking wave propagation into account in the formulation of a Dynamic Stiffness Matrix. The procedure is presented in the context of the harmonic response of acoustic pressure. This development was validated by comparing the harmonic response calculations performed using the continuous element model with the analytical solution. In addition, this paper illustrates the application of this method to a simple compressible flow problem, since it has been applied solely to structural problems to date.

Protective Effect of Ceratonia siliqua L. Against a Dextran Sulfate Sodium-Induced Alterations in Liver and Kidney in Rat

Kais Rtibi,Slimen Selmi,Mohammed-Amine Jabri,Jamel El-Benna,Mohamed Amri,Lamjed Marzouki,Hichem Sebai 한국식품영양과학회 2016 Journal of medicinal food Vol.19 No.9

The aim of the present study is to investigate the potential protective role of Ceratonia siliqua L. against dextran sodium sulfate (DSS)-induced oxidative damage and inflammation in liver and kidney of rats. The hepatotoxicity and nephrotoxicity were induced in rats by oral administration of synthetic DSS (5%) in the drinking water for over 7 days. However, carob pods aqueous extract (CPAE; 50 and 100 mg/kg body weight) was given by oral administration for 21 days. Myeloperoxidase (MPO) activity, malondialdehyde, H2O2 content, as well as the levels of antioxidant enzymes in organs were measured to observe the possible mechanisms. As a result, the CPAE counteracted DSS-induced increase of MPO activity, lipoperoxidation, and the activity of antioxidant enzymes, such as superoxide dismutase and catalase (CAT). DSS administration increased also in the organs hydrogen peroxide (H2O2) and free iron levels, whereas the CPAE pretreatment reversed all intracellular mediator perturbations. It was concluded that the CPAE exerted a potential protective effect against DSSinduced inflammation and oxidative stress in the rat organs. Consequently, it is essential that adequate care is taken when we use carob pods for patients with hepatotoxicity and nephrotoxicity.

Gastroprotective and Antioxidant Properties of Trigonella foenum graecum Seeds Aqueous Extract (Fenugreek) and Omeprazole Against Ethanol-Induced Peptic Ulcer

Slimen Selmi,Dhouha Alimi,Kais Rtibi,Saber Jedidi,Dhekra Grami,Lamjed Marzouki,Karim Hosni 한국식품영양과학회 2022 Journal of medicinal food Vol.25 No.5

Trigonella foenum graecum (Fenugreek) is used in traditional phytomedicine for its anti-inflammatory, antiseptic, antidiabetic, and several other therapeutic virtues. The current study was intended to investigate the protecting effects of fenugreek seeds’ aqueous extract (FSAE) using experimentally ethanol (EtOH)-induced gastric peptic ulcer in rats, as immense alcohol consumption can lead to gastric ulcer. Sixty adult male Wistar rats were divided into 6 groups of 10 each: control, EtOH (4 g/kg body weight [b.w.]), EtOH + several doses of FSAE (50, 100, and 200 mg/kg b.w.), and EtOH + Omeprazole (OM, 20 mg/kg orally [p.o.]). Animals were p.o. pretreated with FSAE for 21 days and exposed to a single oral administration of EtOH (4 g/kg b.w.) for 2 h. Gastric ulcer in rats was induced with a single dose of EtOH. Ulcer index, malondialdehyde (MDA), hydrogen peroxide (H2O2), and thiol groups (-SH) content in stomach, and antioxidant enzymes superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) were measured. Our recorded results showed that EtOH induced gastric damage, evidenced by the level of oxidative stress markers such as MDA and H2O2 in rats exposed to EtOH. However, significant increases in the activities of antioxidant enzymes were recorded, such as SOD, CAT, and GPx, and a decrease in nonenzymatic antioxidants, such as (-SH). Moreover, histopathological examinations showed the presence of lesions associated with severe tissue damage in the untreated rats. Interestingly, FSAE meaningfully protects against all gastric damages caused by EtOH. We propose that FSAE exhibits protective effects in EtOH-induced peptic ulcer in rats. This protection might be related to its antioxidant and anti-inflammatory properties as well as its opposite effects on some studied intracellular mediators.

Opposite Effect of Opuntia ficus-indica L. Juice Depending on Fruit Maturity Stage on Gastrointestinal Physiological Parameters in Rat

Kais Rtibi,Slimen Selmi,Dhekra Grami,Mohamed Amri,Hichem Sebai,Lamjed Marzouki 한국식품영양과학회 2018 Journal of medicinal food Vol.21 No.6

The phytochemical composition and the effect of the green and ripe Opuntia ficus-indica juice on some gastrointestinal (GI) physiological parameters such as stomach emptying and small-intestinal motility and permeability were determined in rats administered multiple concentrations of the prickly pear juice (5, 10, and 20 mL kg−1, b.w., p.o.). Other separate groups of rats were received, respectively; sodium chloride (0.9%, b.w., p.o.), clonidine (α-2-adrenergic agonist, 1 mg kg−1, b.w., i.p.), yohimbine (α-2-adrenergic antagonist, 2 mg kg−1, b.w., i.p.), and loperamide (5 mg kg−1, b.w., p.o.). In vivo reverse effect of juice on GI physiological parameters was investigated using a charcoal meal test, phenol-red colorimetric method, loperamide-induced acute constipation, and castor oil-caused small-bowel hypersecretion. However, the opposite in vitro influence of juice on intestinal permeability homeostasis was assessed by the Ussing chamber system. Mature prickly pear juice administration stimulated significantly and dose dependently the GI transit (GIT; 8–26%) and gastric emptying (0.9–11%) in a rat model. Conversely, the immature prickly pear juice reduced gastric emptying (7–23%), GIT (10–28%), and diarrhea (59–88%). Moreover, the standard drugs have produced their antagonistic effects on GI physiological functions. The permeability of the isolated perfused rat small-intestine has a paradoxical response flowing prickly pear juices administration at diverse doses and maturity grade. Most importantly, the quantitative phytochemical analyses of both juices showed a different composition depending on the degree of maturity. In conclusion, the prickly pear juice at two distinct phases of maturity has different phytochemical characteristics and opposite effects on GI physiological actions in rat.

Coherent Lattice Vibrations in Mono- and Few-Layer WSe₂

Jeong, Tae Young,Jin, Byung Moon,Rhim, Sonny H.,Debbichi, Lamjed,Park, Jaesung,Jang, Yu Dong,Lee, Hyang Rok,Chae, Dong-Hun,Lee, Donghan,Kim, Yong-Hoon,Jung, Suyong,Yee, Ki Ju American Chemical Society 2016 ACS NANO Vol.10 No.5

<P>We report the observation of coherent lattice vibrations in mono- and few-layer WSe2 in the time domain, which were obtained by performing time-resolved transmission measurements. Upon the excitation of ultrashort pulses with the energy resonant to that of A excitons, coherent oscillations of the A(1g) optical phonon and longitudinal acoustic phonon at the M point of the Brillouin zone (LA(M)) were impulsively generated in monolayer WSe2. In multilayer WSe2 flakes, the interlayer breathing mode (B-1) is found to be sensitive to the number of layers, demonstrating its usefulness in characterizing layered transition metal dichalcogenide materials. On the basis of temperature-dependent measurements, we find that the Aig optical phonon mode decays into two acoustic phonons through the anharmonic decay process.</P>