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      • Cytotoxicity of Trichoderma spp. Cultural Filtrate Against Human Cervical and Breast Cancer Cell Lines

        El-Rahman, Atef Abd El-Mohsen Abd,El-Shafei, Sally Mohamed Abd El-Aziz,Ivanova, Elena Vladimirovna,Fattakhova, Alfia Nurlimanovna,Pankova, Anna Victorovna,El-Shafei, Mohamed Abd El-Aziz,El-Morsi, El-M Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.17

        Trichoderma spp. are known as a rich source of secondary metabolites with biological activity belonging to a variety of classes of chemical compounds. These fungi also are well known for their ability to produce a wide range of antibiotic substances and to parasitize other fungi. In search for new substances, which might act as anticancer agents, the overall objective of this study was to investigate the cytotoxic effects of Trichoderma harzianum and Trichoderma asperellum cultural filtrates against human cervical and breast cancer cell lines (HeLa and MCF-7 cells respectively). To achieve this objective, cells were exposed to 20, 40, 60, 80 and 100 mg/ml of both T. harzianum cultural filtrate (ThCF) and T. asperellum cultural filtrate (TaCF) for 24h, then the cell viability and the cytotoxic responses were assessed by using trypan blue and 3-(4,5-dimethylthiazol-2yl)-2,5-biphenyl tetrazolium bromide (MTT) assays. Morphological changes in cells were investigated by phase contrast inverted microscopy. The results showed that ThCF and TaCF significantly reduce the cell viability, have cytotoxic effects and alter the cellular morphology of HeLa and MCF-7 cells in a concentration dependent manner. A concentration of 80 and 100mg/ml of ThCF resulted in a sharp decline in the cell viability percent of HeLa and MCF-7 respectively (25.2%, 26.5%) which was recorded by trypan blue assay. The half-maximal inhibitory concentrations ($IC_{50}$) of ThCF and TaCF in HeLa and MCF-7 were recorded as 16.6, 12.0, 19.6 and 0.70mg/ml respectively by MTT assay. These results revealed that ThCF and TaCF have a substantial ability to reduce the viability and proliferation of human cervical and breast cancer cells.

      • SCIESCOPUS

        Effect of Phosphoric Acid on the Electronic and Diffusion Properties of the Anodic Passive Layer Formed on Pb-1.7%Sb Grid of Lead-acid Batteries

        El-Rahman, H.A. Abd,Salih, S.A.,El-Wahab, A.M. Abd The Korean Electrochemical Society 2011 Journal of electrochemical science and technology Vol.2 No.2

        Potentiostatic oxidation of Pb-1.7%Sb alloy used in the manufacture of grids of lead-acid batteries over the potential range from -1.0V to 2.3V in 5M $H_2SO_4$ in the absence and the presence of 0.4M $H_3PO_4$ and the self-discharge characteristics of the oxide layer formed is studied by electrochemical impedance spectroscopy (EIS). Depending on the potential value, sharp variations in resistance and capacitance of the alloy are recorded during the oxidation and they can be used for identification of the various substances involved in passive layer. Addition of $H_3PO_4$ is found to deteriorate the insulating properties of the passive layer by the retardation of the formation of $PbSO_4$. $H_3PO_4$ completely inhibits the current and impedance fluctuations recorded in $H_3PO_4$-free solutions in the potential range 0.5 V-1.7 V. These fluctuations are attributed to the occurrence of competitive redox processes that involve the formation of $PbSO_4$, $PbOSO_4$, PbO and $PbO_2$ and the repeated formation and breakdown of the passive layer. Self-discharge experiments indicate that the amount of $PbO_2$ formed in the presence of $H_3PO_4$ is lesser than in the $H_3PO_4$-free solutions. The start of transformation of $PbSO_4$ into $PbO_2$ is greatly shortened. $H_3PO_4$ facilitates the diffusion process of soluble species through the passive layer ($PbSO_4$ and basic $PbSO_4$) but impedes the diffusion process through $PbO_2$.

      • SCOPUSKCI등재

        Synthesis and Antiviral Activity of 3-Aminoindole Nucleosides of 2-Acetamido-2-deoxy-D-glucose

        Abdel-Rahman, Adel A.H.,El-Latif, Mona M. Abd,El-Essawy, Farag A.,Barakat, Yousif A. Korean Chemical Society 2012 Bulletin of the Korean Chemical Society Vol.33 No.10

        A new method for the construction of 3-aminoindole nucleosides of 2-acetamido-2-deoxy-D-glucose based is presented. Nitration and acetylation of the indole nucleosides by acetic anhydride-nitric acid mixture followed by reduction using silver catalyst (SNSM) impregnated on silica gel, afforded the corresponding amino indole nucleosides. The nucleosides were tested for antiviral activity against hepatitis B virus (HBV) to show different degrees of antiviral activities or inhibitory actions.

      • SCIESCOPUS

        Evaluation of Tolerance of Some Elemental Impurities on Performance of Pb-Ca-Sn Positive Pole Grids of Lead-Acid Batteries

        Abd El-Rahman, H.A.,Gad-Allah, A.G.,Salih, S.A.,Abd El-Wahab, A.M. The Korean Electrochemical Society 2012 Journal of electrochemical science and technology Vol.3 No.3

        The electrochemical performance of positive pole grids of lead-acid batteries made of Pb-0.08%Ca-1.1%Sn alloys without and with 0.1 wt% of each of Cu, As or Sb and with 0.1 wt% of Cu, As and Sb combined was investigated by electrochemical methods in 4.0 M $H_2SO_4$. The corrodibility of alloys under open-circuit conditions and constant current charging of the positive pole, the positive pole gassing and the self-discharge of the charged positive pole were studied. All impurities (Cu, As, Sb) were found to decrease the corrosion resistance, $R_{corr}$ after 1/2 hour corrosion, but after 24 hours an improvement in $R_{corr}$ was recorded for Sb containing alloy and the alloy with the three impurities combined. While an individual impurity was found to enhance oxygen evolution reaction, the impurities combined significantly inhibition this reaction and the related water loss problem was improved. Impedance results were found helpful in identification of the species involved in the charging/discharging and the self-discharge of the positive pole. Impurities individually or combined were found to increase the self-discharge during polarization (33-68%), where Sb containing alloy was the worst and impurities combined alloy was the least. The corrosion of the positive pole grid in the constant current charging was found to increase in the presence of impurities by 5-10%. Under open-circuit, the self-discharge of the charged positive grids was found to increase significantly (92-212%) in the presence of impurities, with Sb-containing alloy was the worst. The important result of the study is that the harmful effect of the studied impurities combined was not additive but sometimes lesser than any individual impurity.

      • Disease Progression from Chronic Hepatitis C to Cirrhosis and Hepatocellular Carcinoma is Associated with Increasing DNA Promoter Methylation

        Zekri, Abd El-Rahman Nabawy,Nassar, Auhood Abdel-Monem,El-Rouby, Mahmoud Nour El-Din,Shousha, Hend Ibrahim,Barakat, Ahmed Barakat,El-Desouky, Eman Desouky,Zayed, Naglaa Ali,Ahmed, Ola Sayed,Youssef, A Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.11

        Background: Changes in DNA methylation patterns are believed to be early events in hepatocarcinogenesis. A better understanding of methylation states and how they correlate with disease progression will aid in finding potential strategies for early detection of HCC. The aim of our study was to analyze the methylation frequency of tumor suppressor genes, P14, P15, and P73, and a mismatch repair gene (O6MGMT) in HCV related chronic liver disease and HCC to identify candidate epigenetic biomarkers for HCC prediction. Materials and Methods: 516 Egyptian patients with HCV-related liver disease were recruited from Kasr Alaini multidisciplinary HCC clinic from April 2010 to January 2012. Subjects were divided into 4 different clinically defined groups - HCC group (n=208), liver cirrhosis group (n=108), chronic hepatitis C group (n=100), and control group (n=100) - to analyze the methylation status of the target genes in patient plasma using EpiTect Methyl qPCR Array technology. Methylation was considered to be hypermethylated if >10% and/or intermediately methylated if >60%. Results: In our series, a significant difference in the hypermethylation status of all studied genes was noted within the different stages of chronic liver disease and ultimately HCC. Hypermethylation of the P14 gene was detected in 100/208 (48.1%), 52/108 (48.1%), 16/100 (16%) and 8/100 (8%) among HCC, liver cirrhosis, chronic hepatitis and control groups, respectively, with a statistically significant difference between the studied groups (p-value 0.008). We also detected P15 hypermethylation in 92/208 (44.2%), 36/108 (33.3%), 20/100 (20%) and 4/100 (4%), respectively (p-value 0.006). In addition, hypermethylation of P73 was detected in 136/208 (65.4%), 72/108 (66.7%), 32/100 (32%) and 4/100 (4%) (p-value <0.001). Also, we detected O6MGMT hypermethylation in 84/208 (40.4%), 60/108 (55.3%), 20/100 (20%) and 4/100 (4%), respectively (p value <0.001. Conclusions: The epigenetic changes observed in this study indicate that HCC tumors exhibit specific DNA methylation signatures with potential clinical applications in diagnosis and prognosis. In addition, methylation frequency could be used to monitor whether a patient with chronic hepatitis C is likely to progress to liver cirrhosis or even HCC. We can conclude that methylation processes are not just early events in hepatocarcinogenesis but accumulate with progression to cancer.

      • Serum Biomarkers for Early Detection of Hepatocellular Carcinoma Associated with HCV Infection in Egyptian Patients

        Zekri, Abdel-Rahman,Youssef, Amira Salah El-Din,Bakr, Yasser Mabrouk,Gabr, Reham Mohamed,El-Rouby, Mahmoud Nour El-Din,Hammad, Ibtisam,Ahmed, Entsar Abd El-Monaem,Marzouk, Hanan Abd El-Haleem,Nabil, M Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.3

        Background: Early detection of hepatocellular carcinoma using serological markers with better sensitivity and specificity than alpha fetoprotein (AFP) is needed. Aims: The aim of this study was to evaluate the diagnostic value of serum sICAM-1, ${\beta}$-catenin, IL-8, proteasome and sTNFR-II in early detection of HCC. Materials and Methods: Serum levels of IL-8, sICAM-1, sTNFR-II, proteasome and ${\beta}$-catenin were measured by ELISA assay in 479 serum samples from 192 patients with HCC, 96 patients with liver cirrhosis (LC), 96 patients with chronic hepatitis C (CHC) and 95 healthy controls. Results: Serum levels of proteasome, sICAM-1, ${\beta}$-catenin and ${\alpha}FP$ were significantly elevated in HCC group compared to other groups (P-value<0.001), where serum level of IL-8 was significantly elevated in the LC and HCC groups compared to CHC and control groups (P-value <0.001), while no significant difference was noticed in patients with HCC and LC (P-value=0.09). Serum level of sTNFR-II was significantly elevated in patients with LC compared to HCC, CHC and control groups (P-value <0.001); also it was significantly higher in HCC compared to CHC and control groups (P-value <0.001). ROC curve analysis of the studied markers between HCC and other groups revealed that the serum level of proteasome had sensitivity of 75.9% and specificity of 73.4% at a cut-off value of $0.32{\mu}g/ml$ with AUC 0.803 sICAM-1 at cut off value of 778ng/ml, the sensitivity was 75.8% and the specificity was 71.8% with AUC 0.776. ${\beta}$-catenin had sensitivity and specificity of 70% and 68.6% respectively at a cut off value of 8.75ng/ml with an AUC of 0.729. sTNFR-II showed sensitivity of 86.3% and specificity of 51.8% at a cut off value of 6239.5pg/ml with an AUC of 0.722. IL-8 had sensitivity of 70.4% and specificity of 52.3% at a cut off value of 51.5pg/ml with AUC 0.631. Conclusions: Our data supported the role of proteasome, sICAM-1, sTNFR-II and ${\beta}$-catenin in early detection of HCC. Also, using this panel of serological markers in combination with ${\alpha}FP$ may offer improved diagnostic performance over ${\alpha}FP$ alone in the early detection of HCC.

      • KCI등재

        Short and Long RC Columns with Internal WWM Reinforcement under Concentric and Eccentric Compression

        Ahmed M. El-Kholy,Safaa F. Abd El-Rahman,Mohamed M. El-Assaly 한국콘크리트학회 2023 International Journal of Concrete Structures and M Vol.17 No.3

        Recently, various types of steel meshes were used as additional internal reinforcement for improving the confinement, ductility, and strength of the reinforced concrete (RC) columns. In this experimental study, a welded wire mesh (WWM) layer was used as an internal reinforcement in addition to the traditional steel reinforcement (longitudinal bars and transverse ties) for short and long RC columns under concentric and eccentric compression. Thirty-six square RC columns with two slenderness ratios λ (height to width ratio) of 9 and 18 were tested under compression with eccentricity ratios e/t (eccentricity to section thickness ratio) of 0, 0.13, and 0.26. The reference columns were traditionally reinforced with longitudinal steel bars and transverse ties with a reference volumetric ratio ρr of 0.44%. The other columns comprised a WWM layer wrapped outside the ties whose volumetric ratio ranged from 0.22% to 0.44%. The results demonstrated that the columns reinforced with a WWM layer in addition to traditional reinforcement showed an improvement in ductility and strength compared to those reinforced with longitudinal bars and transverse ties only. A WWM layer increased the ultimate load of the columns comprising ρr ties by approximately 16% and 9% for short and long columns, respectively. These improvements were proportional to the ties volumetric ratio.

      • KCI등재

        Immunohistochemical expression of programmed death-ligand 1 and CD8 in glioblastomas

        Dina Mohamed El Samman,Manal Mohamed El Mahdy,Hala Sobhy Cousha,Zeinab Abd El Rahman Kamar,Khaled Abdel Karim Mohamed,Hoda Hassan Abou Gabal 대한병리학회 2021 Journal of Pathology and Translational Medicine Vol.55 No.6

        Background: Glioblastoma is the most aggressive primary malignant brain tumor in adults and is characterized by poor prognosis. Immune evasion occurs via programmed death-ligand 1 (PD-L1)/programmed death receptor 1 (PD-1) interaction. Some malignant tumors have responded to PD-L1/PD-1 blockade treatment strategies, and PD-L1 has been described as a potential predictive biomarker. This study discussed the expression of PD-L1 and CD8 in glioblastomas.Methods: Thirty cases of glioblastoma were stained immunohistochemically for PD-L1 and CD8, where PD-L1 expression in glioblastoma tumor tissue above 1% is considered positive and CD-8 is expressed in tumor infiltrating lymphocytes. The expression of each marker was correlated with clinicopathologic parameters. Survival analysis was conducted to correlate progression-free survival (PFS) and overall survival (OS) with PD-L1 and CD8 expression.Results: Diffuse/fibrillary PD-L1 was expressed in all cases (mean expression, 57.6%), whereas membranous PD-L1 was expressed in six of 30 cases. CD8-positive tumor-infiltrating lymphocytes (CD8+ TILs) had a median expression of 10%. PD-L1 and CD8 were positively correlated (p = .001). High PD-L1 expression was associated with worse PFS and OS (p = .026 and p = .001, respectively). Correlation of CD8+ TILs percentage with age, sex, tumor site, laterality, and outcomes were statistically insignificant. Multivariate analysis revealed that PD-L1 was the only independent factor that affected prognosis.Conclusions: PD-L1 expression in patients with glioblastoma is robust; higher PD-L1 expression is associated with lower CD8+ TIL expression and worse prognosis.

      • KCI등재

        A Systems Engineering Approach to Multi-Physics Load Follow Simulation of the Korean APR1400 Nuclear Power Plant

        Mahmoud, Abd El Rahman,Diab, Aya The Korean Society of Systems Engineering 2020 시스템엔지니어링학술지 Vol.16 No.2

        Nuclear power plants in South Korea are operated to cover the baseload demand. Hence they are operated at 100% rated power and do not deploy power tracking control except for startup, shutdown, or during transients. However, as the contribution of renewable energy in the energy mix increases, load follow operation may be needed to cover the imbalance between consumption and production due to the intermittent nature of electricity produced from the conversion of wind or solar energy. Load follow operation may be quite challenging since the operators need to control the axial power distribution and core reactivity while simultaneously conducting the power maneuvering. In this paper, a systems engineering approach for multi-physics load follow simulation of APR1400 is performed. RELAP5/SCDAPSIM/MOD3.4/3DKIN multi-physics package is selected to simulate the Korean Advanced Power Reactor, APR1400, under load follow operation to reflect the impact of feedback signals on the system safety parameters. Furthermore, the systems engineering approach is adopted to identify the requirements, functions, and physical architecture to provide a set of verification and validation activities that guide this project development by linking each requirement to a validation or verification test with predefined success criteria.

      • KCI등재

        Fabrication and electrical characterization of p-Sb_2S_3/n-Si heterojunctions for solar cells application

        K.F. Abd-El-Rahman,A.A.A. Darwish 한국물리학회 2011 Current Applied Physics Vol.11 No.6

        Antimony trisulphide (Sb_2S_3) films were prepared by thermal evaporation technique on n-type single crystal Si substrates to fabricate p-Sb_2S_3/n-Si heterojunctions. The electrical transport properties of the peSb_2S_3/n-Si heterojunctions were investigated by currentevoltage (I―V) and capacitance―voltage (C―V) measurements. The temperature-dependent I―V characteristics revealed that the forward conduction was determined by multi-step tunnelling current and the activation energy of saturation current was about 0.54 eV. The 1/C^2―V plots indicated the junction was abrupt and the junction built-in potential was 0.6 V at room temperature and decreased with increasing temperature. The solar cell parameters have been calculated for the fabricated cell as V_oc = 0.50 V, J_sc = 14.53 mA cm^-2, FF = 0.32 and η = 4.65% under an illumination of 50 mW cm^-2.

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