RISS 학술연구정보서비스

검색
다국어 입력

http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.

변환된 중국어를 복사하여 사용하시면 됩니다.

예시)
  • 中文 을 입력하시려면 zhongwen을 입력하시고 space를누르시면됩니다.
  • 北京 을 입력하시려면 beijing을 입력하시고 space를 누르시면 됩니다.
닫기
    인기검색어 순위 펼치기

    RISS 인기검색어

      검색결과 좁혀 보기

      선택해제
      • 좁혀본 항목 보기순서

        • 원문유무
        • 원문제공처
          펼치기
        • 등재정보
        • 학술지명
          펼치기
        • 주제분류
        • 발행연도
          펼치기
        • 작성언어
        • 저자
          펼치기

      오늘 본 자료

      • 오늘 본 자료가 없습니다.
      더보기
      • 무료
      • 기관 내 무료
      • 유료
      • In vitro Evaluation of Cytotoxic Activities of Essential Oil from Moringa oleifera Seeds on HeLa, HepG2, MCF-7, CACO-2 and L929 Cell Lines

        Elsayed, Elsayed Ahmed,Sharaf-Eldin, Mahmoud A.,Wadaan, Mohammad Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.11

        Moringa oleifera Lam. (Moringaceae) is widely consumed in tropical and subtropical regions for their valuable nutritional and medicinal characteristics. Recently, extensive research has been conducted on leaf extracts of M. oleifera to evaluate their potential cytotoxic effects. However, with the exception of antimicrobial and antioxidant activities, little information is present on the cytotoxic activity of the essential oil obtained from M. oleifera seeds. Therefore, the present investigation was designed to investigate the potential cytotoxic activity of seed essential oil obtained from M. oleifera on HeLa, HepG2, MCF-7, CACO-2 and L929 cell lines. The different cell lines were subjected to increasing oil concentrations ranging from 0.15 to 1 mg/mL for 24h, and the cytotoxicity was assessed using MTT assay. All treated cell lines showed a significant reduction in cell viability in response to the increasing oil concentration. Moreover, the reduction depended on the cell line as well as the oil concentration applied. Additionally, HeLa cells were the most affected cells followed by HepG2, MCF-7, L929 and CACO-2, where the percentages of cell toxicity recorded were 76.1, 65.1, 59.5, 57.0 and 49.7%, respectively. Furthermore, the $IC_{50}$ values obtained for MCF-7, HeLa and HepG2 cells were 226.1, 422.8 and $751.9{\mu}g/mL$, respectively. Conclusively, the present investigation provides preliminary results which suggest that seed essential oil from M. oleifera has potent cytotoxic activities against cancer cell lines.

      • SCIESCOPUSKCI등재

        Simulation Study of a New Approach for Field Weakening Control of PMSM

        Elsayed, Mohamed Taha,Mahgoub, Osama Ahmed,Zaid, Sherif Ahmed The Korean Institute of Power Electronics 2012 JOURNAL OF POWER ELECTRONICS Vol.12 No.1

        In this paper, the different techniques for the field weakening, also known as constant power speed range (CPSR) operation, for permanent magnet synchronous motor (PMSM) will be introduced and analysed. Field weakening of PMSM, can be done using either vector control (VC) or conventional phase in advance (CPA). Implementation of these techniques depending on some features and constrains. Most of these features and constrains came from the motor parameters. One of these constrains is the motor inductance which determining whether the motor can be driven in the CPSR or not. A new approach for the field weakening will be discussed and to be verified to overcome this constrain. The new approach will be verified through both techniques VC and CPA.

      • SCOPUSSCIEKCI등재

        Infantile Dural Arteriovenous Fistula of the Transverse Sinus Presenting with Ocular Symptoms, Case Reports and Review of Literature

        Sultan, Ahmed Elsayed,Hassan, Tamer The Korean Neurosurgical Society 2016 Journal of Korean neurosurgical society Vol.59 No.3

        Dural arteriovenous fistula (DAVF) of the transverse sinus with ophthalmic manifestations in young children are rare. We reviewed two cases of direct AVF of the transverse sinus with ocular manifestations managed at our institution. The first, a 2.5 years old male child presented with left exophthalmos. Angiography revealed AVF between the occipital artery and the transverse sinus. The second, a 2 years old female child, complained of left exophthalmos. Imaging studies showed bilateral direct AVFs of the transverse sinus with bilateral dysmaturation of the sigmoid sinus. Transarterial embolization was done in both cases. Clinical and radiological follow up revealed complete cure. This report suggests that DAVF of the transverse sinus supplied by the external carotid branches can present with ophthalmic manifestations especially if there is distal venous stenosis or obliteration involving sigmoid sinus. Transarterial embolization using coils and liquid embolic agents could be safe and feasible to obliterate the fistula.

      • KCI등재

        Simulation Study of a New Approach for Field Weakening Control of PMSM

        Mohamed Taha Elsayed,Osama Ahmed Mahgoub,Sherif Ahmed Zaid 전력전자학회 2012 JOURNAL OF POWER ELECTRONICS Vol.12 No.1

        In this paper, the different techniques for the field weakening, also known as constant power speed range (CPSR) operation, for permanent magnet synchronous motor (PMSM) will be introduced and analysed. Field weakening of PMSM, can be done using either vector control (VC) or conventional phase in advance (CPA). Implementation of these techniques depending on some features and constrains. Most of these features and constrains came from the motor parameters. One of these constrains is the motor inductance which determining whether the motor can be driven in the CPSR or not. A new approach for the field weakening will be discussed and to be verified to overcome this constrain. The new approach will be verified through both techniques VC and CPA.

      • SCOPUSKCI등재SCIE

        Using nano-magnesium oxide/bentonite composite for cadmium removal from industrial wastewater

        Elsayed A. Elkhatib,Mohamed L. Moharem,Ahmed F. Saad,Farida A. Attia 대한환경공학회 2023 Environmental Engineering Research Vol.28 No.2

        Nowadays, the removal of toxic heavy metals from industrial wastewater is a long standing problem due to the industrial progress worldwide. This study mainly focused on the production of a novel nMgO-bentonite nanocomposite using sol–gel method to enhance Cd ions removal from industrial wastewater. The nMgO-bentonite nano-composite was characterized for structural morphology and presence of functional groups using SEM/EDS, XRD and FTIR analysis. Cadmium sorption equilibrium and kinetic data were well fitted to Langmuir and power function models respectively as confirmed by the highest R² (0.965), and the lowest SE (38<SUP>*</SUP>10<SUP>-6</SUP>) values among other studied models. The Langmuir removal capacity of the nanocomposite is 200 ㎎/g which is 60 times greater than that of bentonite. Increased Cd sorption on nano-composite with increased temperature from 287 to 307K and the thermodynamic results revealed that Cd adsorption process was endothermic and spontaneous. The data also showed highly repetitive application of nano-composite during six cycles of adsorption/ desorption experiment. The final results pointed out that nMgO-bentonite nano-composite has great adsorption affinity for Cd and could potentially employ as a cost-effective, ecofriendly and efficient sorbent for Cd removal from contaminated wastewater.

      • Resistin and Insulin Resistance: A Link Between Inflammation and Hepatocarcinogenesis

        Elsayed, Engy Yousry,Mosalam, Nesreen Ahmed,Mohamed, Noha Refaat Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.16

        Background: Hepatocellular carcinoma (HCC) is the sixth most common cancer and the third leading cause of cancer related death overall. The role of insulin resistance in the development of HCC associated with chronic HCV infection has not been established. Resistin is a polypeptide hormone belonging to the adipokine family which could contribute to tumorigenesis and angiogenesis. Our aim was to study serum resistin and insulin resistance as risk factors for HCC in HCV cirrhotic patients. Materials and Methods: This prospective case controlled study included 100 patients with HCV related liver cirrhosis and HCC, 100 patients with HCV related liver cirrhosis without HCC and 50 apparently healthy participants as controls. For all subjects, liver profile, serologic markers for viral hepatitis, lipid profile, alpha-fetoprotein level (AFP), homeostasis model assessment (HOMA) were examined along with resistin. Results: HCC patients had higher mean values of HOMA-IR and resistin than cirrhotic patients and the control subjects (p<0.01). HOMA and resistin were considered independent risk factors in development of HCC, those patients with resistin > 12 ng/ml and HOMA > 4 being 1.6 times more likely to have HCC. Conclusions: HOMA and serum resistin allow for early identification of patients with cirrhosiswho are at substantially increased risk of HCC. Recommendation: HOMA and serum resistin could represent novel markers to identify HCV cirrhotic patients at greater risk of development of HCC.

      • New Cellular Neural Networks Template for Image Halftoning based on Bayesian Rough Sets

        Elsayed Radwan,Basem Y. Alkazemi,Ahmed I. Sharaf International Journal of Computer ScienceNetwork S 2023 International journal of computer science and netw Vol.23 No.4

        Image halftoning is a technique for varying grayscale images into two-tone binary images. Unfortunately, the static representation of an image-half toning, wherever each pixel intensity is combined by its local neighbors only, causes missing subjective problem. Also, the existing noise causes an instability criterion. In this paper an image half-toning is represented as a dynamical system for recognizing the global representation. Also, noise is reduced based on a probabilistic model. Since image half-toning is considered as 2-D matrix with a full connected pass, this structure is recognized by the dynamical system of Cellular Neural Networks (CNNs) which is defined by its template. Bayesian Rough Sets is used in exploiting the ideal CNNs construction that synthesis its dynamic. Also, Bayesian rough sets contribute to enhance the quality of the halftone image by removing noise and discovering the effective parameters in the CNNs template. The novelty of this method lies in finding a probabilistic based technique to discover the term of CNNs template and define new learning rules for CNNs internal work. A numerical experiment is conducted on image half-toning corrupted by Gaussian noise.

      • KCI등재

        THE EXPRESSIONS OF SOLUTIONS AND THE PERIODICITY OF SOME RATIONAL DIFFERENCE EQUATIONS SYSTEMS

        AHMED, A.M.,ELSAYED, E.M. The Korean Society for Computational and Applied M 2016 Journal of applied mathematics & informatics Vol.34 No.1

        In this paper we deal with the expressions of solutions and the periodicity nature of some systems of nonlinear difference equations with order three with nonzero real numbers initial conditions.

      • KCI등재

        Preparation of Polyurethane Silicon Oxide Nanomaterials as a Binder in Leather Finishing

        Hamed Elsayed,Rasha Attia,Ola Mohamed,Ahmed Haroun,Nabil El-Sayed 한국섬유공학회 2018 Fibers and polymers Vol.19 No.4

        Leather finishing processes using toxic organic solvent based produce volatile organic compounds (VOC), chronic exposure to this chemicals effect on workers' health causing many diseases especially lung cancer. So, polyurethane waterbased was synthesized for application in leather finishing instead of organic solvent based because it’s economic and safety for industry and workers. Preparation of water-based polyurethane (PU) depends on the reaction of polyethylene glycol (PEG, 300) with isophorone diisocyanate (IPDI) and the reaction of IPDI-1,4-butanediol (BDO) together with dimethylolpropionic acid (DMPA), was synthesized by poly-addition polymerization reaction. PU was then modified with different amounts of silicon dioxide nanoparticles (1-5 % SiO2), used as a binder in leather finishing. Leather coated was characterized physically, chemically and thermally by FTIR, GPC, DLS, TEM, SEM and TGA. The results revel that, water vapor permeability (WVP) of leather coated with PU modified with SiO2 showed improvement due to the existence of SiO2 particles which increases the interspaces of the polyurethane coating. SEM showed that when the amount of SiO2 nanoparticles increases, there is uniform nanoparticles accumulated can be observed. EDX prove the presence of Si and O2 elements and the formation of SiO2 nanoparticles. Mechanical properties discussed that tensile strength; tear strength and elongation at break % increase with increase SiO2 concentration until 3 % SiO2 nanoparticles. TGA showed an improvement of thermal stability of coated leather modified with SiO2. Therefore, this study succeeded in preparation of safe, ecofriendly of water-based polyurethane binders which modified with SiO2 for using in leather finishing.

      • KCI등재

        The expressions of solutions and the periodicity of some rational difference equations systems

        A.M. Ahmed,E.M. Elsayed 한국전산응용수학회 2016 Journal of applied mathematics & informatics Vol.34 No.1

        In this paper we deal with the expressions of solutions and the periodicity nature of some systems of nonlinear difference equations with order three with nonzero real numbers initial conditions.

      연관 검색어 추천

      이 검색어로 많이 본 자료

      활용도 높은 자료

      해외이동버튼