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      • KCI등재

        Histological and Physiological Studies of the Effect of Bone Marrow-Derived Mesenchymal Stem Cells on Bleomycin Induced Lung Fibrosis in Adult Albino Rats

        Zakaria Dina Mohamed,Zahran Noha Mahmoud,Arafa Samia Abdel Aziz,Mehanna Radwa Ali,Abdel-Moneim Rehab Ahmed 한국조직공학과 재생의학회 2021 조직공학과 재생의학 Vol.18 No.1

        Background: Lung fibrosis is considered as an end stage for many lung diseases including lung inflammatory disease, autoimmune diseases and malignancy. There are limited therapeutic options with bad prognostic outcome. The aim of this study was to explore the effect of mesenchymal stem cells (MSCs) derived from bone marrow on Bleomycin (BLM) induced lung fibrosis in albino rats. Methods: 30 adult female albino rats were distributed randomly into 4 groups; negative control group, Bleomycin induced lung fibrosis group, lung fibrosis treated with bone marrow-MSCs (BM-MSCs) and lung fibrosis treated with cell free media. Lung fibrosis was induced with a single dose of intratracheal instillation of BLM. BM-MSCs or cell free media were injected intravenously 28 days after induction and rats were sacrificed after another 28 days for assessment. Minute respiratory volume (MRV), forced vital capacity (FVC) and forced expiratory volume 1 (FEV1) were recorded using spirometer (Power lab data acquisition system). Histological assessment was performed by light microscopic examination of H&E, and Masson’s trichrome stained sections and was further supported by morphometric studies. In addition, electron microscopic examination to assess ultra-structural changes was done. Confocal Laser microscopy and PCR were used as tools to ensure MSCs homing in the lung. Results: Induction of lung fibrosis was confirmed by histological examination, which revealed disorganized lung architecture, thickened inter-alveolar septa due excessive collagen deposition together with inflammatory cellular infiltration. Moreover, pneumocytes depicted variable degenerative changes. Reduction in MRV, FVC and FEV1 were recorded. BM-MSCs treatment showed marked structural improvement with minimal cellular infiltration and collagen deposition and hence restored lung architecture, together with lung functions. Conclusion: MSCs are promising potential therapy for lung fibrosis that could restore the normal structure and function of BLM induced lung fibrosis. Background: Lung fibrosis is considered as an end stage for many lung diseases including lung inflammatory disease, autoimmune diseases and malignancy. There are limited therapeutic options with bad prognostic outcome. The aim of this study was to explore the effect of mesenchymal stem cells (MSCs) derived from bone marrow on Bleomycin (BLM) induced lung fibrosis in albino rats. Methods: 30 adult female albino rats were distributed randomly into 4 groups; negative control group, Bleomycin induced lung fibrosis group, lung fibrosis treated with bone marrow-MSCs (BM-MSCs) and lung fibrosis treated with cell free media. Lung fibrosis was induced with a single dose of intratracheal instillation of BLM. BM-MSCs or cell free media were injected intravenously 28 days after induction and rats were sacrificed after another 28 days for assessment. Minute respiratory volume (MRV), forced vital capacity (FVC) and forced expiratory volume 1 (FEV1) were recorded using spirometer (Power lab data acquisition system). Histological assessment was performed by light microscopic examination of H&E, and Masson’s trichrome stained sections and was further supported by morphometric studies. In addition, electron microscopic examination to assess ultra-structural changes was done. Confocal Laser microscopy and PCR were used as tools to ensure MSCs homing in the lung. Results: Induction of lung fibrosis was confirmed by histological examination, which revealed disorganized lung architecture, thickened inter-alveolar septa due excessive collagen deposition together with inflammatory cellular infiltration. Moreover, pneumocytes depicted variable degenerative changes. Reduction in MRV, FVC and FEV1 were recorded. BM-MSCs treatment showed marked structural improvement with minimal cellular infiltration and collagen deposition and hence restored lung architecture, together with lung functions. Conclusion: MSCs are promising potential therapy for lung fibrosis that could restore the normal structure and function of BLM induced lung fibrosis.

      • SCIESCOPUSKCI등재

        Discrimination between demagnetization and eccentricity faults in PMSMs using real and imaginary components of stator current spectral analysis

        Gherabi, Zakaria,Toumi, Djilali,Benouzza, Noureddine,Boudinar, Ahmed Hamida,Koura, Mohamed Boudiaf The Korean Institute of Power Electronics 2021 JOURNAL OF POWER ELECTRONICS Vol.21 No.1

        Permanent magnet demagnetization and rotor eccentricity are the main faults in permanents magnet synchronous motors (PMSMs). To detect these faults, motor current signature analysis (MCSA) has become the most common method in the field due to its simplicity, low computation time, and remote monitoring capability. Unfortunately, this method has a major drawback relating to the frequency signatures of demagnetization and eccentricity faults, which appear in the same frequency locations. To avoid this drawback while retaining the main advantages of the MCSA method, this paper proposes a new approach for discrimination between demagnetization and eccentricity faults in PMSMs. The proposed approach is based on the simultaneous monitoring of the real and imaginary components of the characteristic harmonics of these faults, which are obtained from stator current spectral analysis. This monitoring is based on the evolution of the characteristic harmonic signs in these two components. The positive or negative signs, make it possible to accurately discriminate between the effects produced by eccentricity faults from the effects produced by demagnetization faults. Finally, several experiments have been presented in this paper to demonstrate the capability and effectiveness of the proposed approach.

      • KCI등재

        Highly Ammonia Sensing Using Direct In Situ Electro-Deposited Polypyrrole-Dodecylbenzene Sulfonic Acid Film on ITO Coated Flexible Substrates

        Fateh Merdj,Ahmed Mekki,Djamil Guettiche,Boualem Mettai,Zakaria Bekkar Djeloul Sayah,Zitouni Safidine,Abderrazak Abdi,Rachid Mahmoud,Mohamed M. Chehimi 한국고분자학회 2018 Macromolecular Research Vol.25 No.6

        Air quality monitoring is of major concern as it is directly linked to public health. It requires the development of high sensitive devices with fast response towards hazardous gas and volatile compounds. Such performances depend on the nature and quality of deposition of the sensing layer. Herein, adherent polypyrroledodecylbenzene sulfonic acid (PPy–DBSA) films were deposited on a N-(3-trimethoxysilylpropyl) pyrrole modified ITO coated polyethylene teraphtalate (PET) flexible substrate by facile direct electrochemical oxidation of pyrrole in an aqueous solution of sulfonic acid. The obtained PPy-DBSA films were subjected to various characterization techniques such as, FTIR, Raman, SEM and conductivity measurements. Chemiresistive gas sensing tests have demonstrated selectivity and sensitivity of films toward ammonia vapors over the other vapors (nitrogen dioxide, carbon dioxide, hydrogen sulfide, acetone, methanol and ethanol) with higher response at 20 ppm, reasonably fast response time of 3 min and reaching detection limit of 3ppm. The response of the sensor can reasonably be related to the strong electrostatic interactions between vapor molecules and the dopant agents within PPy films. In comparison PPy- DBSA films prepared on pristine ITO/PET has exhibited lower response at 20 ppm of ammonia exposure, which highlights the role of surface modification and the contribution from the dopant agent nature for ammonia sensing. Moreover, chemiresistive response performances have been tested in the presence of humidity, under varied temperatures, and finally their behaviors were featured by an impedance spectroscopy in both presence and absence of gas. This work conclusively shows that the sensing performances are not only driven by the molecular interactions between the sensor and the analyte but also by the quality of deposition and adhesion of the former to the transducer. The latter feature can be controlled by appropriate chemical surface modification.

      • KCI등재

        Calcium release and physical properties of modified carbonate apatite cement as pulp capping agent in dental application

        Myrna Nurlatifah Zakaria,Arief Cahyanto,Ahmed El-Ghannam 한국생체재료학회 2018 생체재료학회지 Vol.22 No.4

        Background: Carbonate apatite (CO3Ap) and silica-calcium phosphate composite (SCPC) are bone substitutes with good prospect for dental application. SCPC creates a hydroxyapatite surface layer and stimulate bone cell function while, CO3Ap induce apatite crystal formation with good adaptation providing good seal between cement and the bone. Together, these materials will add favorable properties as a pulp capping material to stimulate mineral barrier and maintain pulp vitality. The aim of this study is to investigate modification of CO3Ap cement combined with SCPC, later term as CO3Ap-SCPC cement (CAS) in means of its chemical (Calcium release) and physical properties (setting time, DTS and pH value). Methods: The study consist of three groups; group 1 (100% calcium hydroxide, group 2 CO3Ap (60% DCPA: 40% vaterite, and group 3 CAS (60% DCPA: 20% vaterite: 20% SCPC. Distilled water was employed as a solution for group 1, and 0.2 mol/L Na3PO4 used for group 2 and group 3. Samples were evaluated with respect to important properties for pulp capping application such as pH, setting time, mechanical strength and calcium release evaluation. Results: The fastest setting time was in CO3Ap cement group without SCPC, while the addition of 20% SCPC slightly increase the pH value but did not improved the cement mechanical strength, however, the mechanical strength of both CO3Ap groups were significantly higher than calcium hydroxide. All three groups released calcium ions and had alkaline pH. Highest pH level, as well as calcium released level, was in the control group. Conclusion: The CAS cement had good mechanical and acceptable chemical properties for pulp capping application compared to calcium hydroxide as a gold standard. However, improvements and in vivo studies are to be carried out with the further development of this material.

      • KCI등재

        Highly Ammonia Sensing Using Direct In Situ Electro-Deposited Polypyrrole-Dodecylbenzene Sulfonic Acid Film on ITO Coated Flexible Substrates

        Fateh Merdj,Ahmed Mekki,Djamil Guettiche,Boualem Mettai,Zakaria Bekkar Djeloul Sayah,Zitouni Safidine,Abderrazak Abdi,Rachid Mahmoud,Mohamed M. Chehimi 한국고분자학회 2018 Macromolecular Research Vol.26 No.6

        Air quality monitoring is of major concern as it is directly linked to public health. It requires the development of high sensitive devices with fast response towards hazardous gas and volatile compounds. Such performances depend on the nature and quality of deposition of the sensing layer. Herein, adherent polypyrroledodecylbenzene sulfonic acid (PPy–DBSA) films were deposited on a N-(3-trimethoxysilylpropyl) pyrrole modified ITO coated polyethylene teraphtalate (PET) flexible substrate by facile direct electrochemical oxidation of pyrrole in an aqueous solution of sulfonic acid. The obtained PPy-DBSA films were subjected to various characterization techniques such as, FTIR, Raman, SEM and conductivity measurements. Chemiresistive gas sensing tests have demonstrated selectivity and sensitivity of films toward ammonia vapors over the other vapors (nitrogen dioxide, carbon dioxide, hydrogen sulfide, acetone, methanol and ethanol) with higher response at 20 ppm, reasonably fast response time of 3 min and reaching detection limit of 3ppm. The response of the sensor can reasonably be related to the strong electrostatic interactions between vapor molecules and the dopant agents within PPy films. In comparison PPy- DBSA films prepared on pristine ITO/PET has exhibited lower response at 20 ppm of ammonia exposure, which highlights the role of surface modification and the contribution from the dopant agent nature for ammonia sensing. Moreover, chemiresistive response performances have been tested in the presence of humidity, under varied temperatures, and finally their behaviors were featured by an impedance spectroscopy in both presence and absence of gas. This work conclusively shows that the sensing performances are not only driven by the molecular interactions between the sensor and the analyte but also by the quality of deposition and adhesion of the former to the transducer. The latter feature can be controlled by appropriate chemical surface modification.

      • KCI등재

        Numerical modeling of the aging effects of RC shear walls strengthened by CFRP plates: A comparison of results from different “code type” models

        Redha Yeghnem,Hicham Zakaria Guerroudj,Lemya Hanifi Hachemi Amar,Sid Ahmed Meftah,Samir Benyoucef,Abdelouahed Tounsi,El Abbas Adda Bedia 사단법인 한국계산역학회 2017 Computers and Concrete, An International Journal Vol.19 No.5

        Creep and shrinkage are the main types of volume change with time in concrete. These changes cause deflection, cracking and stresses that affect durability, serviceability, long-term reliability and structural integrity of civil engineering infrastructure. Although laboratory test may be undertaken to determine the deformation properties of concrete, these are time-consuming, often expensive and generally not a practical option. Therefore, relatively simple empirically design code models are relied to predict the creep strain. This paper reviews the accuracy of creep and shrinkage predictions of reinforced concrete (RC) shear walls structures strengthened with carbon fibre reinforced polymer (CFRP) plates, which is characterized by a widthwise varying fibre volume fraction. This review is yielded by three commonly used international “code type” models. The assessed are the: CEB-FIP MC 90 model, ACI 209 model and Bazant & Baweja (B3) model. The time-dependent behavior was investigated to analyze their seismic behavior. In the numerical formulation, the adherents and the adhesives are all modelled as shear wall elements, using the mixed finite element method. Several tests were used to dem¬onstrate the accuracy and effectiveness of the proposed method. Numerical results from the present analysis are presented to illustrate the significance of the time-dependency of the lateral displacements and eigenfrequencies modes.

      • SCIESCOPUSKCI등재

        Diagnosis and discernment between eccentricity and demagnetization faults in PMSM drives

        Koura, Mohamed Boudiaf,Boudinar, Ahmed Hamida,Aimer, Ameur Fethi,Bendiabdellah, Azzedine,Gherabi, Zakaria The Korean Institute of Power Electronics 2021 JOURNAL OF POWER ELECTRONICS Vol.21 No.3

        This paper proposes a new approach that allows the diagnosis and the ability of discernment between the frequency signatures of eccentricity faults and those of demagnetization in a permanent magnet synchronous motor (PMSM). This approach is based on the application of a very selective band-pass filter in the stator current. A judicious calculation of the parameters of this filter makes it possible to extract only the frequency signatures of searched faults. The use of the relevant information on the magnitude and phase angle of the signatures, obtained by filtering, makes it possible to distinguish between both of the studied faults. The simple monitoring of the plotting in terms of polar coordinates of the combined information (magnitude/phase angle) of the signature's characteristic of these two faults allows for this discernment. Experimental results show the effectiveness of the proposed approach when it comes to the diagnosis reliability of demagnetization and the eccentricity faults in a PMSM.

      • KCI등재

        Assessment of Drag Prediction Techniques for a Flying Vehicle Based on Radar-Tracked Data

        M. Doso,M. Y. Zakaria,Mahmoud Y. M. Ahmed,Mostafa Khalil 한국항공우주학회 2024 International Journal of Aeronautical and Space Sc Vol.25 No.1

        As far as the aerodynamic characterization of a flying vehicle is concerned, flight testing is probably the most accurate approach as it perfectly resembles the real flight environment. Flight data are obtained by tracking the vehicle via radars if modifying the vehicle design is not recommended/attainable. In the open literature, different techniques are used to analyze radar data; the key issue is the computational demands of each technique and the quality of the resulting aerodynamic characteristics. In this paper, three techniques are considered namely, Least-Square (LS), Maximum-Likelihood Estimation (MLE), and Stepwise Regression (SR), with focus on the prediction of the drag coefficient of a case study vehicle. Features for each technique are addressed based on brief previous published data. A new variant of the MLE method is proposed based on the physical segmentation of the available dataset. Predicted point-mass trajectories are compared with own comprehensive flight test to assess the techniques in concern. It is concluded that Stepwise-regression outperforms with a large dataset, while Maximum-Likelihood Estimation is more feasible considering the lack of data. The proposed variant of the MLE method yields more accurate drag prediction compared to the basic one.

      • KCI등재후보

        Protective effect of rosemary on acrylamide motor neurotoxicity in spinal cord of rat offspring

        Marwa A. Al-Gholam,Hanaa Zakaria Nooh,Abeer E. El-Mehi,Abd El-Moneum El-Barbary,Ahmed Zo El Fokar 대한해부학회 2016 Anatomy & Cell Biology Vol.49 No.1

        The direct interactive effects of rosemary and acrylamide on the development of motor neurons in the spinal cord remains unknown. Our goal is to confirm the protective effects of rosemary against motor neuronal degeneration induced by acrylamide in the developing postnatal rat spinal cord using a postnatal rat model. We assigned the offspring of treated female rats into control, rosemary; acrylamide group; and recovery groups. This work depended on clinical, histopathological, morphometrically, immunohistochemical and genetic methods. In the acrylamide group, we observed oxidation, motor neuron degeneration, apoptosis, myelin degeneration, neurofilament reduction, reactive gliosis. Whoever, concomitant rosemary intake and withdrawal of acrylamide modulate these effects. These findings proof that dietary rosemary can directly protect motor neuron against acrylamide toxicity in the mammalian developing spinal cord.

      • KCI등재

        DFT and experimental study on adsorption of dyes on activated carbon prepared from apple leaves

        Abdel-Aziz Mohamed Helmy,El-Ashtoukhy Elsayed Zakaria,Bassyouni Mohamed,Al-Hossainy Ahmed Farouk,Fawzy Eman M.,Abdel-Hamid Shereen M. S.,Zoromba Mohamed Shafick 한국탄소학회 2021 Carbon Letters Vol.31 No.5

        This work reports utilization of apple leaves as a source of activated carbon. Activated carbon from apple leaves is prepared by two diferent methods, thermal activation where AC1 is obtained and chemical activation using H3PO4 and ZnCl2 where AC2 and AC3 are obtained, respectively. XRD analysis revealed that all types of prepared ACs have a semi-crystalline nature with a mean crystallite size of 13, 21.02, and 39.47 nm for AC1, AC2, and AC3, respectively. To identify the most suitable desorption temperature, the exothermic behavior was discovered for the three types of ACs by DSC. The exothermic onset temperatures are 340 °C, 200 °C, 400 °C, or AC1, AC2, and AC3, respectively. The point of zero charge for the three types of ACs is 8.6, 7.3, and 2.5 for AC1, AC2, and AC3, respectively. The BET surface area analysis data demonstrated that mesoporous structure was developed in AC1 and AC2, while a microporous structure was developed in AC3. Quantum chemical calculations for ACs is carried out using Density Functional Theory (DFT). Application of the prepared ACs in adsorption of basic dye C.I. base blue 47 is studied. The maximum removal efciency was 65.1%, 96% and 99% for AC1, AC2, and AC3, respectively under the infuence of diferent operating aspects. Adsorption data are modeled by Langmuir, Freundlich, and Temkin isotherms. The data revealed that adsorption of basic dye C.I. base blue 47 on AC1 follows Langmuir isotherm and adsorption on AC2 and AC3 follows Freundlich isotherm.

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