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      • KCI등재

        Efficacy of Nile tilapia (Oreochromis niloticus) juveniles and spinosyns bioinsecticides against aquatic stages of Culex pipiens: An experimental study

        Mohamed Ibrahim A.,Fathy Mohamed,Farghal Ahmed I.A.,Temerak Sobhy A.H.,Sayed Alaa El-Din H. 한국응용곤충학회 2021 Journal of Asia-Pacific Entomology Vol.24 No.1

        The mosquito Culex pipiens is the most widely distributed dipteran species in all regions of Egypt and the principal vector of Wuchereria bancrofti and certain arboviruses in human beings. For controlling C. pipiens vector, biological tools (e.g., larvivorous fish and bioinsecticides) are more potent and safer options to the environment, human beings, and beneficial organisms than chemical pesticides. The efficiency of O. niloticus juveniles as predatory fish species and two bioinsecticides, spinosad 24% and spinetoram 12%, was investigated against the C. pipiens developmental stages in the laboratory. The first trial evaluated the predatory efficacy of small-sized O. niloticus (2.1–2.6 cm; 250–315 mg) and large-sized O. niloticus (2.5–3.2 cm; 250–315 mg) against the 3rd larvae and pupae of C. pipiens. This is the first report in Egypt confirming the predation potential of O. niloticus as efficient predatory fish against the immature C. pipiens. Large-sized O. niloticus predated a greater number of 3rd of C. pipiens larvae and pupae than the small-sized ones. Furthermore, the daily consumption of C. pipiens larvae by small- and large-sized O. niloticus was significantly higher than the pupae. The second trial assessed the toxicity efficacy of spinosad 24% and spinetoram 12% against C. pipiens larvae and pupae. The results confirmed that the tested bioinsecticides showed higher potency toward C. pipiens larvae than pupae after exposure for 24 h and 48 h. Spinosad was more toxic toward 3rd C. pipiens larvae (LC 50 = 0.013 and 0.003 mg/L) and pupae (LC 50 = 320.69 and 44.28 mg/L) than spinetoram after 24 and 48 h. Herein, O. niloticus juveniles (as promising native predatory fish) and spinosyns bioinsecticides were more effective against C. pipiens in the larval stage than in the pupal stage. In conclusion, Nile tilapia juveniles and biorational compounds, spinosad 24% and spinetoram 12%, might be considered as promising and favorable environmental biological agents for controlling C. pipiens in Egypt. However, further trials are needed to investigate the potential of these agents in the control of this mosquito vector under field conditions.

      • Memory response in elasto-thermoelectric spherical cavity

        El-Attar, Sayed I.,Hendy, Mohamed H.,Ezzat, Magdy A. Techno-Press 2020 Coupled systems mechanics Vol.9 No.4

        A mathematical model of electro-thermoelasticity subjected to memory-dependent derivative (MDD) heat conduction law is applied to a one-dimensional problem of a thermoelectric spherical cavity exposed to a warm stun that is an element of time in the presence of a uniform magnetic field. Utilizing Laplace transform as an instrument, the issue has been fathomed logically within the changed space. Numerical inversion of the Laplace transform is carried for the considered distributions and represented graphically. Some comparisons are shown in the figures to estimate the effects of MDD parameters and thermoelectric properties on the behavior of all considered fields.

      • KCI등재

        Identification of Green Alga Chlorella vulgaris Isolated from Freshwater and Improvement Biodiesel Productivity via UV Irradiation

        ( Mohamed A. Gomaa ),( Mohamed H. Refaat ),( Tamer M. Salim ),( Abo El-khair B. El-sayed ),( Makhlouf M. Bekhit ) 한국미생물생명공학회(구 한국산업미생물학회) 2019 한국미생물·생명공학회지 Vol.47 No.3

        Chlorella vulgaris was isolated from the Nile River, Qalubia Governorate, Egypt, for possible use in biodiesel production. BG-II nutrient growth media was used for isolation and laboratory growth. Identification was performed via 18S rRNA gene amplification, followed by sequencing. The alga was exposed to UVC (254 nm) for 15, 30, and 45 s to improve dry weight accumulation and to increase the oil production. Daily measurements of dry weight (g·l<sup>-1</sup>) were performed; oil content and volumetric lipid productivity were also determined. UV-C exposure led to an increase in the volumetric lipid productivity by 27, 27.3, and 32.4 mg·l<sup>-1</sup>·d<sup>-1</sup> with 15, 30, and 45 s, respectively, as compared with the control, which resulted in 18 mg·l<sup>-1</sup>·d<sup>-1</sup>. Of the examined mutants, the one with the highest productivity was re-irradiated by UV-C (254 nm) for 15, 30, 45, and 60 s. For 15 s of exposure time, the oil content increased to 34%, while it was 31% at 30 s; further, it decreased to 22% at 45 and 60 s exposures. The fatty acid methyl ester profile was 82.22% in the first mutant at 45 s, compared with the wild strain that contained a total of 66.01% of FAs. Furthermore, the highest levels of polyunsaturated fatty acid methyl ester were observed in the mutant exposed for 45 s, and it reached 11.41%, which reduced the cetane number to 71.3.

      • KCI등재

        Antagonistic Potentiality of Actinomycete- Derived Extract with Anti-Biofilm, Antioxidant, and Cytotoxic Capabilities as a Natural Combating Strategy for Multidrug-Resistant ESKAPE Pathogens

        El-Sayed Mohamed H.,Alshammari Fahdah A.,Sharaf Mohammed H. 한국미생물·생명공학회 2023 Journal of microbiology and biotechnology Vol.33 No.1

        The global increase in multidrug-resistant (MDR) bacteria has inspired researchers to develop new strategies to overcome this problem. In this study, 23 morphologically different, soil-isolated actinomycete cultures were screened for their antibacterial ability against MDR isolates of ESKAPE pathogens. Among them, isolate BOGE18 exhibited a broad antibacterial spectrum, so it was selected and identified based on cultural, morphological, physiological, and biochemical characteristics. Chemotaxonomic analysis was also performed together with nucleotide sequencing of the 16S rRNA gene, which showed this strain to have identity with Streptomyces lienomycini. The ethyl acetate extract of the cell-free filtrate (CFF) of strain BOGE18 was evaluated for its antibacterial spectrum, and the minimum inhibitory concentration (MIC) ranged from 62.5 to 250 μg/ml. The recorded results from the in vitro anti-biofilm microtiter assay and confocal laser scanning microscopy (CLSM) of sub-MIC concentrations revealed a significant reduction in biofilm formation in a concentration-dependent manner. The extract also displayed significant scavenging activity, reaching 91.61 ± 4.1% and 85.06 ± 3.14% of 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), respectively. A promising cytotoxic ability against breast (MCF-7) and hepatocellular (HePG2) cancer cell lines was obtained from the extract with IC50 values of 47.15 ± 13.10 and 122.69 ± 9.12 μg/ml, respectively. Moreover, based on gas chromatography-mass spectrometry (GC-MS) analysis, nine known compounds were detected in the BOGE18 extract, suggesting their contribution to the multitude of biological activities recorded in this study. Overall, Streptomyces lienomycini BOGE18-derived extract is a good candidate for use in a natural combating strategy to prevent bacterial infection, especially by MDR pathogens.

      • KCI등재

        Rhizospheric-Derived Nocardiopsis alba BH35 as an Effective Biocontrol Agent Actinobacterium with Antifungal and Plant Growth-Promoting Effects: In Vitro Studies

        El-Sayed Mohamed H.,Kobisi  Abd El-Nasser A.,Elsehemy  Islam A.,El-Sakhawy and  Mohamed A. 한국미생물·생명공학회 2023 Journal of microbiology and biotechnology Vol.33 No.5

        The biocontrol approach using beneficial microorganisms to control crop diseases is becoming an essential alternative to chemical fungicides. Therefore, new and efficient biocontrol agents (BCA) are needed. In this study, a rhizospheric actinomycete isolate showed unique and promising antagonistic activity against three of the most common phytopathogenic fungi, Fusarium oxysporum MH105, Rhizoctonia solani To18, and Alternaria brassicicola CBS107. Identification of the antagonistic strain, which was performed according to spore morphology and cell wall chemotype, suggested that it belongs to the Nocardiopsaceae. Furthermore, cultural, physiological, and biochemical characteristics, together with phylogenetic analysis of the 16S rRNA gene (OP869859.1), indicated the identity of this strain to Nocardiopsis alba. The cell-free filtrate (CFF) of the strain was evaluated for its antifungal potency, and the resultant inhibition zone diameters ranged from 17.0 ± 0.92 to 19.5 ± 0.28 mm for the tested fungal species. Additionally, the CFF was evaluated in vitro to control Fusarium wilt disease in Vicia faba using the spraying method under greenhouse conditions, and the results showed marked differences in virulence between the control and treatment plants, indicating the biocontrol efficacy of this actinomycete. A promising plant-growth promoting (PGP) ability in seed germination and seedling growth of V. faba was also recorded in vitro for the CFF, which displayed PGP traits of phosphate solubilization (48 mg/100 ml) as well as production of indole acetic acid (34 μg/ml) and ammonia (20 μg/ml). This study provided scientific validation that the new rhizobacterium Nocardiopsis alba strain BH35 could be further utilized in bioformulation and possesses biocontrol and plant growth-promoting capabilities.

      • Lack of Any Relationship Between Circulating Autoantibodies and Interleukin-6 Levels in Egyptian Patients Infected with the Hepatitis C Virus

        Nasr, Mohamed Y,Deeb, Ammar S Ali,Badra, Gamal,Sayed, Ibrahim H El Asian Pacific Journal of Cancer Prevention 2016 Asian Pacific journal of cancer prevention Vol.17 No.11

        Introduction: Elevated serum interleukin (IL) 6 has been reported in patients infected with the hepatitis C virus (HCV), but it remains debatable whether this influences the production of autoantibodies and the biochemical profile of HCV disease. Therefore, this current study was conducted to evaluate the relationship between IL-6 and circulating autoantibody levels in HCV positive patients. Methods: Levels of IL-6 in serum samples from 102 patients with HCV and 103 normal controls were determined by enzyme linked immunosorbent assay (ELISA). Autoantibodies were detected by immunofluorescence. Results: Levels of IL-6 were significantly higher (p=0.028) in patients infected with (HCV) compared with normal group. Autoantibodies were noted in in 43.1% of the patients; of these, 23.5% featured anti-nuclear antibodies (ANA+), 16.7% anti-smooth muscle antibodies (ASMA+), 7.8% anti-mitochondrial antibodies (AMA+), 17.6% anti-parietal cell antibodies (APCA+), 7.8% anti canalicular antibodies, and 2.9% anti reticulin antibodies (ARA+). No patients were found to be positive for anti-brush border antibodies (ABBA) or anti-ribosomal antibodies. (ARiA). No links with IL-6 levels were apparent. Conclusions: IL-6 levels are increased in patients infected with HCV disease and could influence the production of autoantibodies. However, this study did not provide evidence of a specific relationship between IL6 and circulating autoantibodies in such cases.

      • SCOPUSKCI등재

        Identification of Green Alga Chlorella vulgaris Isolated from Freshwater and Improvement Biodiesel Productivity via UV Irradiation

        Gomaa, Mohamed A.,Refaat, Mohamed H.,Salim, Tamer M.,El-Sayed, Abo El-Khair B.,Bekhit, Makhlouf M. The Korean Society for Microbiology and Biotechnol 2019 한국미생물·생명공학회지 Vol.47 No.3

        Chlorella vulgaris was isolated from the Nile River, Qalubia Governorate, Egypt, for possible use in biodiesel production. BG-II nutrient growth media was used for isolation and laboratory growth. Identification was performed via 18S rRNA gene amplification, followed by sequencing. The alga was exposed to UV-C (254 nm) for 15, 30, and 45 s to improve dry weight accumulation and to increase the oil production. Daily measurements of dry weight ($g{\cdot}l^{-1}$) were performed; oil content and volumetric lipid productivity were also determined. UV-C exposure led to an increase in the volumetric lipid productivity by 27, 27.3, and $32.4mg{\cdot}l^{-1}{\cdot}d^{-1}$ with 15, 30, and 45 s, respectively, as compared with the control, which resulted in $18mg{\cdot}l^{-1}{\cdot}d^{-1}$. Of the examined mutants, the one with the highest productivity was re-irradiated by UV-C (254 nm) for 15, 30, 45, and 60 s. For 15 s of exposure time, the oil content increased to 34%, while it was 31% at 30 s; further, it decreased to 22% at 45 and 60 s exposures. The fatty acid methyl ester profile was 82.22% in the first mutant at 45 s, compared with the wild strain that contained a total of 66.01% of FAs. Furthermore, the highest levels of polyunsaturated fatty acid methyl ester were observed in the mutant exposed for 45 s, and it reached 11.41%, which reduced the cetane number to 71.3.

      • [論文] Application of Nonlinear Goal Programming to Structural Optimization

        장태사(T.S.Jang),모하메드 엘 세이드(Mohamed E.M.El-Sayed),김호룡(H.R.Kim) 한국자동차공학회 1992 오토저널 Vol.14 No.1

        본 논문은 비선형 goal Programming을 이용하여 구조 최적화 문제들의 해를 얻는 방법을 제시한다. 이 방법은 다기준 최적화의 도구로 사용되는데 그 까닭은 goal Programming 이 목적함수와 제한조건 등을 정의하는데 있어서 발생하는 난점들을 제거해 주며, 또한 설계목적의 우선 순위를 다루는 능력을 갖추고 있기 때문이다.<br/> 비선형 goal Programming에 대한 구조 최적화의 모델이 제시된다. Hooke-Jeeves의 patt-ern탐색, 수정된 Hooke-Jeeves의 Pattern 탐색, 그리고 Powell의 공액뱡향 탐색방향을 이용한 세 가지의 비선향 goal Programming들이 개발되고 토의된다. 설계 도구로서 이 방법의 유효성을 논증하기 위하여 사례의 해를 모색하며 이를 다른 연구결과와 비교 검토한다.

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