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Mowafi Marwa M.,Elbeialy Marwa A. K.,Abusinna Rasha Gamal 대한마취통증의학회 2023 Korean Journal of Anesthesiology Vol.76 No.6
Background: Respiratory mechanics are often significantly altered in morbidly obese patients and magnesium sulfate (MgSO4) is a promising agent for managing several respiratory disorders. This study aimed to examine the effects of MgSO4 infusions on arterial oxygenation and lung mechanics in patients with morbid obesity undergoing laparoscopic bariatric surgery. Methods: Forty patients with morbid obesity aged 21–60 years scheduled for laparoscopic bariatric surgery under general anesthesia were randomly allocated to either the control (normal saline infusion) or MgSO4 group (30 mg/kg lean body weight [LBW] of 10% MgSO4 in 100 ml normal saline intravenously over 30 min as a loading dose, followed by 10 mg/kg LBW/h for 90 min). The primary outcome was intraoperative arterial oxygenation (ΔPaO2/FiO2). Secondary outcomes included intraoperative static and dynamic compliance, dead space, and hemodynamic parameters. Results: At 90 min intraoperatively, the Δ PaO2/FiO2 ratio and the Δ dynamic lung compliance were statistically significantly higher in the MgSO4 group (mean ± SE: 16.1 ± 1.0, 95% CI [14.1, 18.1] and 8.4 ± 0.5 ml/cmH2O, 95% CI [7.4, 9.4]), respectively), and the Δ dead space (%) was statistically significantly lower in the MgSO4 group (mean ± SE: −8.0 ± 0.3%, 95% CI [−8.6, −7.4]) (P < 0.001). No significant differences in static compliance were observed.Conclusions: Although MgSO4 significantly preserved arterial oxygenation and maintained dynamic lung compliance and dead space in patients with morbid obesity, the clinical relevance is minimal. This study failed to adequately reflect the clinical importance of these results.
Marwa H. Gouda,Noha A. Elessawy,Arafat Toghan 한국공업화학회 2021 Journal of Industrial and Engineering Chemistry Vol.100 No.-
A direct borohydride fuel cell (DBFC) is a type of low temperature fuel cell, and to commercialize this typeof fuel cell, it requires efficient and inexpensive proton exchange membranes. In this study, a binarypolymer blend is formulated from inexpensive and ecofriendly polymers such as iota carrageenan (IC)and polyvinyl alcohol (PVA). Zirconiam phosphate (ZrPO4) was synthesized from a simple impregnation— calcination method and later embedded as a doping agent into the polymeric matrix with percentage(1–7.5) wt.%. The novel nanocomposite membranes were evaluated by TGA, DSC, FTIR, XRD and SEM. Theoxidative stability and tensile strength of the obtained membranes were enhanced and achieved resultsbetter than those of Nafion117 due to an increase in the number of hydrogen bonds formed between thepolymer functional groups and oxygen functional groups of ZrPO4with increasing doping concentration. In addition, the borohydride permeability of the membranes decreased with increasing ZrPO4weightpercentage, while the ionic conductivity and power density increased to 25.5 mS cm 1 and 66 mW cm 2,respectively, for membrane with 5 wt.% of ZrPO4. The fabricated membrane with the optimum properties(PVA/IC/ZrPO45) can be efficient as a proton exchange membrane towards the development of greenand low cost DBFCs.
Agar-Carrageenan Hydrogel Blend as a Carrier for the Covalent Immobilization of β-D-Galactosidase
Marwa I. Wahba,Mohamed E. Hassan 한국고분자학회 2017 Macromolecular Research Vol.25 No.9
κ-Carrageenan (Car) was mixed with agar in order to improve the treated gel’s ability to covalently immobilize enzymes. The treatment process of the produced agar-Car gel involved reacting with both polyethyleneimine and glutaraldehyde so as to provide the functional groups necessary for the covalent binding of enzymes. The positive effect imparted by the addition of Car to agar was confirmed through the statistical Plackett-Burman design (PBD). The PBD was employed to investigate the effects of 11 factors on the preparation of the treated agar-Car gel disks, and the immobilization of β-D-galactosidase (β-gal) onto these disks. The PBD provided recommendations on the levels at which 10 of the tested factors should be employed in the future as these factors were shown to be insignificant. On the other hand, the significant factor, the loading enzyme’s activity, was optimized in order to attain the maximum observed activity of immobilized β-gal which amounted to 166.2 U/g gel. It was also shown that the agar-Car immobilized β-gal maintained 97.7% of its initial observed activity during its fifteenth reusability cycle.
Performance Limits of Three-Phase Self-Excited Induction Generator (SEIG) as a Stand Alone DER
Marwa Ben Slimene,Mohamed Arbi Khlifi 대한전기학회 2017 Journal of Electrical Engineering & Technology Vol.12 No.1
This paper present a unified method of steady state performance analysis and limits characteristics of an autonomous three-phase self-excited induction generator (SEIG) driven by a wind turbine under different types of loads and speeds. The proposed method is based on a new mathematical function to solve for the real and imaginary components of the complex equation of the mathematical model. Performances limits, regulation and characteristics of different configurations will be thoroughly examined and compared. The proposed system will be modeled and simulated and the performance limits characteristics will be compared with variable speed and variable capacity.
Marwa Batnini,Imen Haddoudi,Wael Taamali,Naceur Djebali,Mounawer Badri,Moncef Mrabet,Haythem Mhadhbi 한국식물병리학회 2021 Plant Pathology Journal Vol.37 No.4
Fusarium and Rhizoctonia genera are important patho- gens of many field crops worldwide. They are constant- ly evolving and expanding their host range. Selecting resistant cultivars is an effective strategy to break their infection cycles. To this end, we screened a collection of Medicago truncatula accessions against Fusarium oxysporum, Fusarium solani, and Rhizoctonia solani strains isolated from different plant species. Despite the small collection, a biodiversity in the disease response of M. truncatula accessions ranging from resistant phe- notypes to highly susceptible ones was observed. A17 showed relative resistance to all fungal strains with the lowest disease incidence and ratings while TN1.11 was among the susceptible accessions. As an initiation of the characterization of resistance mechanisms, the antioxidant enzymes’ activities, at the early stages of infections, were compared between these contrasting accessions. Our results showed an increment of the antioxidant activities within A17 plants in leaves and roots. We also analyzed the responses of a population of recombinant inbred lines derived from the crossing of A17 and TN1.11 to the infection with the same fungal strains. The broad-sense heritability of measured traits ranged from 0.87 to 0.95, from 0.72 to 0.96, and from 0.14 to 0.85 under control, F. oxysporum, and R. solani conditions, respectively. This high estimated heritability underlines the importance of further molecular analy- sis of the observed resistance to identify selection mark- ers that could be incorporated into a breeding program and thus improving soil-borne pathogens resistance in crops.
Experimental shear strengthening of GFRC beams without stirrups using innovative techniques
Marwa Hany,Mohamed H. Makhlouf,Gamal Ismail,Ahmed S. Debaiky 국제구조공학회 2022 Structural Engineering and Mechanics, An Int'l Jou Vol.83 No.4
Eighteen (18) (120×300×2200 mm) beams were prepared and tested to evaluate the shear strength of Glass Fiber Reinforced Concrete (GFRC) beams with no shear reinforcement, and evaluate the effectiveness of various innovative strengthening systems to increase the shear capacity of the GFRC beams. The test variables are the amount of discrete glass fiber (0.0, 0.6, and 1.2% by volume of concrete) and the type of longitudinal reinforcement bars (steel or GFRP), the strengthening systems (externally bonded (EB) sheet, side near-surface mounted (SNSM) bars, or the two together), strengthening material (GFRP or steel) links, different configurations of NSM GFRP bars (side bonded links, full wrapped stirrups, side C-shaped stirrups, and side bent bars), link spacing, link inclination angle, and the number of bent bars. The experimental results showed that adding the discrete glass fiber to the concrete by 0.6%, and 1.2% enhanced the shear strength by 18.5% and 28%, respectively in addition to enhancing the ductility. The results testified the efficiency of different strengthening systems, where it is enhanced the shear capacity by a ratio of 28.4% to 120%, and that is a significant improvement. Providing SNSM bent bars with strips as a new strengthening technique exhibited better shear performance in terms of crack propagation, and improved shear capacity and ductility compared to other strengthening techniques. Based on the experimental shear behavior, an analytical study, which allows the estimation of the shear capacity of the strengthened beams, was proposed, the results of the experimental and analytical study were comparable by a ratio of 0.91 to 1.15.
Marwa Khammassi,Maud Miguet,Valérie Julian,Charlotte Cardenoux,Yves Boirie,Martine Duclos,Bruno Pereira,David Thivel 대한비만학회 2020 The Korean journal of obesity Vol.29 No.4
Background: To evaluate the impact of 4 months of a high-intensity interval training (HIIT)-centered weight-management intervention on health-related quality of life (HR-QOL), health perception (HP) and physical self-perception (PSP) in adolescents with obesity. Methods: Fifty-six adolescents with obesity (28 girls; mean body mass index [BMI], 35±4.89 kg/m2; z-BMI, 2.3±0.3; 11–17 years) followed a multidisciplinary weight-management intervention composed of nutritional counseling, HIIT program, and health-related therapeutic education. Anthropometric parameters, body composition (dual X-ray absorptiometry), and maximal aerobic capacities (maximal oxygen consumption [VO2peak]) were assessed, and self-reported questionnaires were used to assess HR-QOL (36-item short form survey), HP and PSP at baseline (T0) and post-intervention (T1). Results: Body weight (92.6±18.9 to 85.9±16.2 kg), BMI (35.0±4.8 to 32.1±4.5 kg/m²), z-BMI (2.3±0.3 to 2.1±0.3) and fat mass percentage (36.0%±9.1% to 30.4%±7.8%) were significantly decreased (P<0.001) between T0 and T1. There was a tendency for VO2peak to increase from 26.35±5.81 mL/kg/min at T0 to 28.79±6.59 mL/kg/min at T1 (P=0.06). Physical functioning (P=0.002), physical limitation (P=0.048), general health (P<0.001) and bodily pain (P=0.030) were improved at T1. A significant improvement occurred in dimensions of HP such as physical condition (P=0.001), adiposity (P<0.001), alimentation (P<0.001), general health (P=0.038), and perceived general health (P=0.001). In addition, there was an improvement in items of PSP such as self-perceived coordination (P=0.022), endurance (P=0.001) and activity (P=0.001), global self-concept (P=0.015), and appearance (P=0.016). Physical but not mental HR-QOL domains, HP and PSP were associated with weight reduction. Conclusion: While HIIT favors improved HR-QOL, HP status and PSP in adolescents with obesity, physical but not mental HR-QOL, HP and PSP were associated with weight reduction.
Assessment of the partial and total replacement of feldspar by waste glass on porcelain properties
Marwa Marza Salman,Hussein Talab Nhabih 한양대학교 세라믹연구소 2020 Journal of Ceramic Processing Research Vol.21 No.3
In this study, soda-lime silica waste glass was used as partial and total replacement for feldspar in porcelain. The preparedsamples from feldspar, quartz, kaolin and different percentages of waste glass by powder technology technique were sinteredat 1,100 ºC and 1,200 ºC. The tests measured for samples involves mechanical, physical and thermal properties. A results ofthese tests indicated an increasing and decreasing in the samples properties with increasing of waste glass additive, and thatcontinues to 75% waste glass of feldspar. While X-ray diffraction analysis indicated a presence of tridymite phase SiO2, mullitephase 2SiO2.3Al2O3 and anorthite phase CaAl2Si2O8 in the sample contained 100% waste glass of feldspar and fired at1,200 ºC. This study showed possibility of replacement of feldspar used in porcelain industry by waste glass as flux, and apercent of waste glass additive, which gives the best properties of porcelain samples, is 75% wt. of feldspar.
Marwa Yousef,Şehrazat Kavraal,Ayşe Seda Artış,Cem Süer 대한정신약물학회 2019 CLINICAL PSYCHOPHARMACOLOGY AND NEUROSCIENCE Vol.17 No.2
Objective: Although, accumulating evidence is delineating a neuroprotective and neurotrophic role for lithium (Li), inconsistent findings have also been reported in human studies especially. Moreover, the effects of Li infusion into the hippocampus are still unknown. The aims of this work were (a) to assess whether basal synaptic activity and long-term potentiation (LTP) in the hippocampus are different in regard to intrahippocampal Li infusion; (b) to assess spatial learning and memory in rats chronically treated with LiCO3 in the Morris water maze. Methods: Field potentials were recorded form the dentate gyrus, stimulating perforant pathways, in rats chronically (20 mg/kg for 40 days) or acutely treated with LiCO3 and their corresponding control rats. In addition, performance of rats in a Morris water maze was measured to link behaviour of rats to electrophysiological findings. Results: LiCO3 infusion into the hippocampus resulted in enhanced LTP, especially in the late phases, but attenuated LTP was observed in rats chronically treated with Li as compared to controls. Li-treated rats equally performed a spatial learning task, but did spend less time in target quadrant than saline-treated rats in Morris water maze. Conclusion: Despite most data suggest that Li always yields neuroprotective effects against neuropathological conditions; we concluded that a 40-day treatment of Li disrupts hippocampal synaptic plasticity underlying memory processes, and that these effects of prolonged treatment are not associated with its direct chemical effect, but are likely to be associated with the molecular actions of Li at genetic levels, because its short-term effect preserves synaptic plasticity.
Marwa Souissi,Ramzi Khiari,Mounir Zaag,Nizar Meksi,Hatem Dhaouadi 한국섬유공학회 2022 Fibers and polymers Vol.23 No.10
Bicomponent polyesters filaments are increasingly used in the textile fields due to their technical and highperformances (mechanical, physical, and chemical properties) comparing to conventional polyethylene terephthalate andElasthaneTM thermoplastic polyether polyurethane used in denim fabrics. The purpose of this work is to evaluate the stabilityof the mechanical and physical properties of bicomponent filaments before and after dyeing with three disperse dyes havingdifferent molecular weights (low, medium, and high). Bicomponent filaments composed of two filaments extruded side byside with two unequal proportions 60 % polyethylene terephthalate (PET) and 40 % polytrimethylene terephthalate (PTT) areused in this study. A full factorial experimental design was established to analyze the dyeing parameters effect (temperatureand pH value of dye bath) and optimize the color strength (K/S) while maintaining the stability of the mechanical andphysical properties of bicomponent filaments. After dyeing, these properties were evaluated and their stability was provedusing several analysis techniques such as SEM, DSC, and XRD.