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Structural and electronic characteristics of pure and doped ZnO varistors

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Chinese Physics B 2012年第11期21卷 352-360页

作者： a.sedky E.El-Suheel Physics Department Faculty of ScienceKing Faisal University Physics Department Faculty of ScienceAssiut University

We report here the structural, surface morphology, mechanical, and current voltage characteristics of Zn1-xMxO ceramic samples with various x and M （0.00≤〈 x ≤ 0.20, M = Ni, Cu）. It is found that the considered dopants do not influence the well-known peaks related to the wurtzite structure of ZnO ceramics, while the shapes and the sizes of grains are clearly affected. The average crystalline diameters deduced from the SEM micrographs are between 2.06 μm and 4.8 μm for all samples. The oxygen element ratio is increased by both dopants. Interestingly, the potential barrier can be formed by adding Cu up to 0.20, while it is completely deformed by 0.025 Ni addition. The breakdown field can be enhanced up to 4138 V/cm by 0.025 Cu addition, followed by a decrease with further increase of Cu up to 0.20. On the other hand, a gradual decrease in Vickers microhardness is reported for both dopants, and the values in the Ni samples are higher compared to those in the Cu samples. The electricul conductivity is generally improved by Ni, while the addition of Cu improves it only in the over doped region （≥ 0.10）. These results are discussed in terms of the differences of valency and ferromagnetic ordering.

关键词： semiconductors chemical synthesis impurity electronic transport

The recent progress on the bioactive compounds from algal biomass for human health applications

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Food Bioscience 2023年第1期51卷 90-108页

作者： Yang Yang sedky HAHassan Mukesh Kumar Awasthi Babu Gajendran Monika Sharma Min-Kyu Ji El-Sayed Salama Department of Occupational and Environmental Health School of Public HealthLanzhou UniversityLanzhou City730000Gansu ProvincePR China Department of Biology College of ScienceSultan Qaboos UniversityMuscat123Oman Botany&Microbiology Department Faculty of ScienceNew Valley UniversityEl-Kharga72511Egypt College of Natural Resources and Environment Northwest A&F UniversityTaicheng Road 3#YanglingShaanxi712100PR China School of Pharmaceutical Sciences Guizhou Medical UniversityGuiyangGuizhou Province550025PR China Environmental Assessment Group Korea Environment InstituteYeongi-gun30147South Korea

The secondary metabolites produced by algae(including macroalgae and microalgae)possess several human health *** bioactive compounds in algae have potential to be used in the medical and pharmaceutical industries for drug *** rapid development of genetic tools and omics approaches has extended the understanding of algal metabolism along with enhanced productivity and improving the properties of bioactive ***,the focus of this review is to discuss the molecular progress on algae for bioactive compound production which includes genomics,transcriptomics,proteomics,and *** comprehensive discussion on multi-omics approaches provides the potential knowledge for future *** structural and functional genomics,application of genetic tools,molecular mechanisms of bioactive compound synthesis,protein modification,and the omics performance of algae at various levels under abiotic stress are *** annotation and identification of key functions are the basis of genomics which provides the comprehensive overview of genetic *** recent development of molecular modifications and their application in algae to produce high-yield bioactive compounds that meet human needs through the optimization of algal target strains are also *** exploration of the molecular mechanisms of bioactive compounds under abiotic stress is of great practical significance to guide the optimization of culture conditions.

关键词： Macroalgae Microalgae Bioactive compounds Omics Abiotic stress

Urodynamic Abnormalities in Patients with Relapsing Remitting Multiple Sclerosis

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World Journal of Neuroscience 2018年第4期8卷 423-431页

作者： Alaaeldin sedky Bekhit Mohammed Saber-Khalaf Department of Neuropsychiatry Sohag University Sohag Egypt Department of Urology Sohag University Sohag Egypt

Background: Multiple sclerosis (MS) is a disease with wide variability in clinical presentation. Bladder dysfunctions are very common in MS patients. Early detection of bladder abnormalities is important to improve the outcome in MS patients. Objectives: The aim of this study is to evaluate the urodynamic detected bladder dysfunctions in relapsing remitting MS patients with mild or without lower urinary tract symptoms. Methods: This is a prospective study for 32 patients with relapsing remitting Multiple Sclerosis from January 2017 to June 2018. We included patients with mild or without lower urinary tract symptoms (LUTS) who had mild to moderate disability. Urodynamic studies were performed for all patients. Results: Urodynamic abnormalities were detected in 22 patients (68.75%). Detrusor overactivity (DO) was present alone in 8 patients (25%);DO combined with detrusor external sphincter dyssynergia in 8 patients (25%);DO with low compliant bladder and impaired contractility in another 4 patients (13%) while DO with low complaint bladder in 2 patients (6%). Bladder dysfunction was correlated to high disability score;longer duration of illness;frequent relapses and the presence of LUTS. Conclusion: Urodynamic abnormalities were found in 68.75% of our patients. This highlights the importance of urodynamic studies in the early evaluation of relapsing remitting Multiple Sclerosis.

关键词： Urodynamic Bladder Dysfunction Multiple Sclerosis

Surface Roughness Modification of Free Standing Single Crystal Silicon Microstructures Using KrF Excimer Laser Treatment for Mechanical Performance Improvement

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Journal of Surface Engineered Materials and Advanced Technology 2015年第1期5卷 28-41页

作者： Mohamed Elwi Mitwally Toshiyuki Tsuchiya Osamu Tabata Sherif sedky Department of Micro Engineering Kyoto University Kyoto Japan Zewail City of Science and Technology Cairo Egypt

Single crystal silicon freestanding structures for tensile and fatigue testing were treated with KrF excimer laser to improve surface roughness and accordingly mechanical performance. Sample thickness was 5 μm. Localized laser treatment was successful in eliminating the scallops developed during Bosch process and in reducing surface roughness. Harsh irradiation at laser energies up to 4 J/cm2 was only possible due to localized treatment without significant vibrations occurring on the freestanding samples that led to fracture in preliminary experiments at energies as low as 0.16 J/cm2. Finite element analysis was used to investigate the temperature distribution on the irradiated structures. Atomic force microscopy (AFM) and Raman spectroscopy were also used to assess surface roughness, crystallinity changes and surface stresses developing on surfaces subjected to perpendicular laser irradiation. At a high energy (3.2 J/cm2) the top surface showed a decrease of roughness compared to fabricated samples. Raman spectroscopy showed the dominance of crystalline silicon after laser irradiation. The effects of laser energy, number of

关键词： Freestanding Mechanical Test Structures Harsh Laser Treatment Surface Roughness Improvement

Effect of Pulsed Laser on the Structure and Morphology of Alumina-Zirconia Coatings

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Journal of Surface Engineered Materials and Advanced Technology 2013年第3期3卷 249-256页

作者： Hala Omar Ahmed Ibrahim Hanadi Salem Sherif sedky Department of Mechanical and Manufacturing Engineering Farmingdale State College Farmingdale USA The American University in Cairo Yousef Jameel Science & Technology Center Cairo Egypt Zewail City of Science & Technology Cairo Egypt.

The effect of excimer laser annealing on the structure and morphology of ceramic coatings were investigated. Alumina-40% zirconia (AZ-40) coatings were sprayed with a water-stabilized plasma spray gun. The coated surface was treated by excimer laser having a wavelength of 248 nm and pulse duration of 24 ns. The surface structure of the treated coating was examined by field emission scanning electron microscope (FESEM) and X-ray diffraction (XRD). A detailed parametric study was performed to investigate the effects of different parameters such as laser energy density (fluence), pulse repetition rate (PRR), and the number of shots on the mechanical properties, surface morphology, and microstructure of the coatings. The results of this study indicated that laser energy and pulse repetition rate have significant effects on surface morphology, porosity, and microstructure of the coating.

关键词： Laser Annealing Alumina-Zirconia Coatings Surface Morphology Plasma Sprayed Coatings

Phytochemical studies and anti-ulcerative colitis effect of Moringa oleifera seeds and Egyptian propolis methanol extracts in a rat model

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Asian Pacific Journal of Tropical Biomedicine 2019年第3期9卷 98-108页

作者： Attia H.Atta Samar M.Mouneir Soad M.Nasr Doaa.sedky Amany M.Mohamed Shimaa A.Atta Hassan Mohamed Desouky Department of Pharmacology Faculty of Veterinary Medicine Cairo University Department of Parasitology & Animal Diseases National Research Centre Immunology Department Theodor Bilharz Research Institute Department of Animal Reproduction and Artificial Insemination National Research Centre

Objective: To analyze the phytochemical constituents, and to explore potential protective effect of the methanol extract of Moringa oleifera(M. oleifera) seeds and Egyptian propolis, each alone or concurrently administered on acetic acid-induced ulcerative colitis in rats. Methods: Eight groups of 5 rats each were used: normal control group with distilled water, model group, two groups with M. oleifera seeds(100 and 200 mg/kg), two groups with propolis(50 and 100 mg/kg), one group with concurrent administration of both, and one group with prednisolone(reference drug). Macro-and microscopic picture, ulcer index and lesion scores, oxidative markers, inflammatory mediators, in vitro activity of the inflammatory enzymes and 1, 1-diphenyl-2-picrylhydrazyl free radicals scavenging activity were evaluated. The phytochemical constituents of both extracts were explored by GC-MS analysis. Results: Both treatments modulated the macro-and microscopic picture, decreased the ulcerative index, lesion score, oxidative markers and inflammatory mediators, and inhibited the COX-1 and COX-2 enzymes. Propolis appeared to be powerful free radicals scavenger. A powerful synergistic effect of both treatments in modulating the course of the disease was reported. GCMS analysis of methanol extract of M. oleifera seeds and propolis revealed the presence of 50 and 34 compounds, respectively. Conclusions: M. oleifera seeds and propolis methanol extracts have modulated the course of acetic acid-induced ulcerative colitis. Moreover, both treatments induce a good synergistic effect against the disease. Isolation of the active constituents is recommended.

关键词： Moringa oleifera seeds Propolis Ulcerative colitis Phytochemical

Bisphosphonates Zoledronate and Alendronate for the Management of Postmenopausal Osteoporosis

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Case Reports in Clinical Medicine 2018年第5期7卷 324-342页

作者： IsraaIsraa Ahmed Radwan Nahed sedky Korany Bassant Adel Ezzat Department of Oral Biology Faculty of Oral and Dental Medicine Cairo University Cairo Egypt

Bisphosphonates are among the most frequently used antiresorptive drugs for the management of postmenopausal osteoporosis. We review here two of the commonly used bisphosphonates zoledronate and alendronate.

关键词： Bisphosphonates Alendronate Zoledronate Postmenopausal Osteoporosis

Phytochemical, antioxidant and hepatoprotective effects of different fractions of Moringa oleifera leaves methanol extract against liver injury in animal model

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Asian Pacific Journal of Tropical Medicine 2018年第7期11卷 423-429页

作者： Attia H.Atta Soad M.Nasr Abduljalil H.Almaweri Doaa.sedky Amany M.Mohamed Hassan M.Desouky Mostafa A.Shalaby Department of Pharmacology Faculty of Veterinary Medicine Cairo University Department of Parasitology & Animal Diseases National Research Centre(Egypt) Department of Animal Reproduction and Artificial Insemination National Research Centre(Egypt)

Objective: To evaluate the potential antioxidant and hepatoprotective effects of n-hexane, dichloromethane(DCM), ethyl acetate(EtOAc), n-butanol and aqueous fractions of Moringa oleifera(M. oleifera) leaves methanol extract against carbon tetrachloride(CCl_4)-induced liver injury in rats. Methods: These fractions were prepared from the M. oleifera leaves methanol extract by solubilization in water and partitioning in n-hexane, EtOAc, DCM and n-butanol. Their phyto-components were identified by GC-MS analysis. The in vitro antioxidant effect of these fractions was carried out by assessment of 1,1-diphenyl-2-picrylhydrazyl scavenging activity. A total of 40 Sprague Dawley rats were allocated into 8 equal groups: group 1 given olive oil(1 m L/kg ***.), group 2 injected with CCl_4, group 3 to 7 administered with n-hexane, DCM, EtOAc, n-butanol and aqueous fractions, respectively after CCl_4, group 8 administered with silymarin after CCl_4. The activities of aspartate aminotransferase, alanine aminotransferase, and the levels of total cholesterol, triglycerides, glucose, total proteins and albumin in serum were determined spectrophotometrically. Glutathione reduced, lipid peroxide by-products levels, glutathione-s-transferase and catalase enzyme activities in the liver homogenate were determined by spectrophotometer. Liver specimens were also examined for histopathological alterations under light microscope. Results: The GCMS analysis of different fractions of the M. oleifera leaves methanol extract revealed that n-hexane, DCM, EtOAc, n-butanol, and aqueous fractions contained 17, 22, 23, 19 and 32 compounds, respectively. The percent and the molecular structure of each component in each fraction were identified. The n-butanol and EtOAc fractions exhibited the strongest in vitro antioxidant activity against 1,1-diphenyl-2-picrylhydrazyl. CCl_4 significantly decreased glutathione reduced and total proteins concentration and glutathione-s-transferase and catalase activiti

关键词： Hepatoprotective Antioxidants Moringa oleifera Fractions Phytochemical

Contribution to the soil-based Egyptian mycobiota in Hypocreales(Sordariomycetes)from Egypt

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Studies in Fungi 2022年第1期7卷 52-57页

作者： Mohamed B.H.Mazen Ahmed M.Moharram sedky H.A.Hassan Salma M.Abdel-Latif Osama A.Al-Bedak Department of Botany and Microbiology Faculty of ScienceAssiut UniversityAssiut 71516Egypt Assiut University Mycological Centre Assiut UniversityAssiut 71515Egypt Department of Botany and Microbiology Faculty of ScienceNew Valley UniversityEl-Kharga 72511Egypt Biology Department College of ScienceSultan Qaboos UniversityMuscat123Oman

During soil fungal surveys in Egypt's New Valley Governorate,four significant fungal isolates from three different species have been *** of these strains were uncovered in Egypt for the first time,while the other two may be potential new *** four strains were identified as being Paramyrothecium spp.(two strains),Striaticonidium brachysporum,and Metarhizium pingshaense after the internal transcribed spacer(ITS)region of the isolates was sequenced and matched to the closest match strains in *** strains in this investigation are being documented for the first time in *** four strains are briefly described and microscopically displayed in the article.

关键词： soil fungal