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      • KCI등재

        New ursane triterpenoids from Ficus pandurata and their binding affinity for human cannabinoid and opioid receptors

        Amgad I. M. Khedr,Sabrin R. M. Ibrahim,Gamal A. Mohamed,Hany E. A. Ahmed,Amany S. Ahmad,Mahmoud A. Ramadan,Atef E. Abd El-Baky,Koji Yamada,Samir A. Ross 대한약학회 2016 Archives of Pharmacal Research Vol.39 No.7

        Phytochemical investigation of Ficus pandurataHance (Moraceae) fruits has led to the isolation of two newtriterpenoids, ficupanduratin A [1b-hydroxy-3b-acetoxy-11a-methoxy-urs-12-ene] (11) and ficupanduratin B [21ahydroxy-3b-acetoxy-11a-methoxy-urs-12-ene] (17), alongwith 20 known compounds: a-amyrin acetate (1), a-amyrin(2), 3b-acetoxy-20-taraxasten-22-one (3), 3b-acetoxy-11amethoxy-olean-12-ene (4), 3b-acetoxy-11a-methoxy-12-ursene (5), 11-oxo-a-amyrin acetate (6), 11-oxo-b-amyrinacetate (7), palmitic acid (8), stigmast-4,22-diene-3,6-dione(9), stigmast-4-ene-3,6-dione (10), stigmasterol (12), b-sitosterol(13), stigmast-22-ene-3,6-dione (14), stigmastane-3,6-dione (15), 3b,21b-dihydroxy-11a-methoxy-olean-12-ene (16), 3b-hydroxy-11a-methoxyurs-12-ene (18), 6-hydroxystigmast-4,22-diene-3-one (19), 6-hydroxystigmast-4-ene-3-one (20), 11a,21a-dihydroxy-3b-acetoxy-urs-12-ene(21), and b-sitosterol-3-O-b-D-glucopyranoside (22). Compound21 is reported for the first time from a natural source. The structures of the 20 compounds were elucidated on thebasis of IR, 1D (1H and 13C), 2D (1H–1H COSY, HSQC,HMBC and NOESY) NMR and MS spectroscopic data, inaddition to comparison with literature data. The isolatedcompounds were evaluated for their anti-microbial, antimalarial,anti-leishmanial, and cytotoxic activities. In addition,their radioligand displacement affinity on opioid andcannabinoid receptors was assessed. Compounds 4, 11, and15 exhibited good affinity towards the CB2 receptor, withdisplacement values of 69.7, 62.5 and 86.5 %, respectively. Furthermore, the binding mode of the active compounds inthe active site of the CB2 cannabinoid receptors was investigatedthrough molecular modelling.

      • The Role of Genetic Polymorphisms in Nrf2 and P73 in Egyptian Women with Breast Cancer

        Azhary, Nevin M Al,Kamel, Mahmoud M,Ismail, Yahia M,Mahmoud, Amal A,Radwan, Enas M Asian Pacific Journal of Cancer Prevention 2016 Asian Pacific journal of cancer prevention Vol.17 No.11

        Background: Breast cancer is the commonest cancer in Egyptian females. Nrf2 is involved in oxidative stress while P73 functions in response to DNA damage. This study aimed to assess the role of Nrf2 promoter and P73 G4C14 to A4T14 SNPs in breast cancer in Egypt. Patients: Eighty-five female patients with breast tumours (41 malignant, 44 benign) were included. Nrf2 (rs6721961) and p73 (G4A) SNPs were determined by PCR- CTPP assay. Results: Genotype frequencies of the Nrf2 promoter SNP were 34.2% and 37.9% for AA in benign and malignant groups respectively, and 43.9% and 40.5% for CC and, 21.9 % and 21.6% for CA. Genotype frequencies for the P73 G4A SNP were 52.9% and 44.7% for GA in benign and malignant groups respectively, and 47.1% and 55.3% for GG. Discussion: Nrf2 genotypes in pre - and post-menopausal patients, showed significantly different distributions in the 2 patient groups, the AA genotype being significantly more common in pre-menopausal patients. The P73 G4A SNP showed no relation to age of disease onset. Conclusion: The Nrf2 (rs6721961) AA genotype might be related to early breast cancer onset. In contrast the P73 G4A polymorphism showed no relation to either disease risk or age at presentation.

      • KCI등재

        MgAl2O4-reinforced c-ZrO2 ceramics prepared by spark plasma sintering

        El-Amir Ahmed A. M.,Li Shufeng,Abdelgawad Mahmoud,Ewais Emad M. M. 한국세라믹학회 2021 한국세라믹학회지 Vol.58 No.5

        c-zirconia ceramic composites have been synthesized by spark plasma sintering (SPS) technique from commercial m-ZrO 2 , Y 2 O 3 and waste-derived magnesium aluminate spinel (MA) powders. In this study, eff ect of MA addition on stabilization and reinforcement of 5 mol% yttria-stabilized zirconia (YSZ) was carefully investigated. Spark plasma sintering of designed powder mixtures at 1400 °C for 30 min and 40 MPa produce fully dense compacts with an average grain size of 0.5–10 μm. The pressure was gradually increased up to 40 MPa using argon gas and was kept until the end of the sintering process. The refi ned microstructure (0.5–10 μm) obtained in this study has achieved superior compaction resistance values that are ten times more than strength values of conventionally sintered specimens. Such improvement in compaction resistance of the sintered specimens was attributed to particle size refi nement and grain boundary enhancement. What’s more, spark-plasma sintered composites containing 10–50 wt% MA revealed higher resistance to low temperature degradation (LTD) than the reference composite that doesn’t contain MA spinel; where about ~ 2.8% of t-ZrO 2 was converted into m-ZrO 2 in case of the latter composite while aging test didn’t infl uence at all on the structure of the former composites. The outcomes indicated that MA has a signifi cant eff ect on m-ZrO 2 stabilization into a cubic phase structure that concurrently owned an enhanced and comparable compression resistance to Yttrium-doped t-ZrO 2 (Y-TZP). In this respect, the ternary oxide ceramic composite systems prepared in this study present huge potential for development c-ZrO 2 -based industrial ceramics with a wide spectrum of mechanical characteristics for high-tech engineering applications of harsh-stress and humid environments.

      • SCIESCOPUSKCI등재

        Allelic variation of melanocortin-1 receptor locus in Saudi indigenous sheep exhibiting different color coats

        Mahmoud, Ahmed H.,Mashaly, Ashraf M.,Rady, Ahmed M.,Al-Anazi, Khalid M.,Saleh, Amgad A. Asian Australasian Association of Animal Productio 2017 Animal Bioscience Vol.30 No.2

        Objective: This study was designed to characterize the DNA polymorphisms of the melanocortin-1 receptor (MC1R) gene in indigenous Saudi Arabian sheep breeds exhibiting different color coats, along with individuals of the Sawaknee breed, an exotic sheep imported from Sudan. Methods: The complete coding region of MC1R gene including parts of 3' and 5' untranslated regions was amplified and sequenced from three the indigenous Saudi sheep; Najdi (generally black, n = 41), Naeimi (generally white with brown faces, n = 36) and Herri (generally white, n = 18), in addition to 13 Sawaknee sheep. Results: Five single nucleotide polymorphisms (SNPs) were detected in the MC1R gene: two led to nonsynonymous mutations (c.218 T>A, p.73 Met>Lys and c.361 G>A, p.121 Asp>Asn) and three led to synonymous mutations (c.429 C>T, p.143 Tyr>Tyr; c.600 T>G, p.200 Leu>Leu, and c.735 C>T, p.245 Ile>Ile). Based on these five SNPs, eight haplotypes representing MC1R $E^d$ and $E^+$ alleles were identified among the studied sheep breeds. The most common haplotype (H3) of the dominant $E^d$ allele was associated with either black or brown coat color in Najdi and Sawaknee sheep, respectively. Two other haplotypes (H6 and H7) of $E^d$ allele, with only the nonsynonymous mutation A218T, were detected for the first time in Saudi indigenous sheep. Conclusion: In addition to investigating the MC1R allelic variation in Saudi indigenous sheep populations, the present study supports the assumption that the two independent nonsynonymous Met73Lys and Asp121Asn mutations in MC1R gene are associated with black or red coat colors in sheep breeds.

      • KCI등재

        Gamma ray shielding characteristics and exposure buildup factor for some natural rocks using MCNP-5 code

        K.A. Mahmoud,M.I. Sayyed,O.L. Tashlykov 한국원자력학회 2019 Nuclear Engineering and Technology Vol.51 No.7

        The mass attenuation coefficient for eight rock samples having different chemical composition was simulated using the MCNP 5 code in energy range . Moreover, the for the studied rock samples was computed theoretically using XCOM database. The comparison between simulated and computed data for all selected rock samples showed a good agreement with differences varied between 0.01 and 8%. The highest was found for basalt rocks M2 and M1 and the lowest one is reported for limestone rocks Dike. The simulated values of the then were used to calculate other important shielding parameters such as the mean free path, effective electron density and effective atomic number. The exposure buildup factor was also computed for the selected rocks with the contribution of G-P fitting parameters and the highest EBF attended by the basalt sample Sill and varied between 1.022 and 744 in the energy range between but the lowest EBF achieved by basalt sample M2 and varied between 1.017 and 491 in the same energy range.

      • KCI등재

        Effect of magnesia rich spinel on densification and stabilization behavior of monoclinic zirconia

        Abdelgawad Mahmoud,El-Gamal S. M. A.,Ewais Emad M. M.,Li Shufeng 한국세라믹학회 2021 한국세라믹학회지 Vol.58 No.3

        Fully cubic-stabilized zirconia ceramic composites have been successfully fabricated by conventional sintering technique using commercial monoclinic zirconia, Yttrium oxide and waste-derived magnesia-rich spinel (MMA) powder mixtures. In this study, eff ect of MMA content and sintering temperature on stabilization and densifi cation properties of zirconia has been duly considered. The obtained results showed that m-ZrO 2 in MMA-free Z0 reference specimen is partially stabilized upon temperature rising into tetragonal phase by Y 3+ ions diff usion inside zirconia structure. MMA-free Z0 reference specimen sintered at 1600 ºC showed m- and t-ZrO 2 dual-phase structure with a relative density of 80.2%. Unlike, upon rising the sintering temperature, Z10–Z50 composites containing 10–50 wt% MMA demonstrated higher relative density of more than 99% and showed variant behavior, where their m-ZrO 2 is transformed and stabilized into cubic form by diff usion of Y 3+ , Mg 2+ and Al 3+ ions inside zirconia lattice structure. The outcomes indicate that MMA has significantly improved both the densification and stabilization behavior of m-ZrO 2 through facilitating Y 3+ diff usion inside zirconia lattice structure.

      • KCI등재

        Stem cell-derived exosomes for dentin-pulp complex regeneration: a mini-review

        Hammouda Dina A.,Mansour Alaa M,Saeed Mahmoud A.,Zaher Ahmed R.,Grawish Mohammed E. 대한치과보존학회 2023 Restorative Dentistry & Endodontics Vol.48 No.2

        This mini-review was conducted to present an overview of the use of exosomes in regenerating the dentin-pulp complex (DPC). The PubMed and Scopus databases were searched for relevant articles published between January 1, 2013 and January 1, 2023. The findings of basic in vitro studies indicated that exosomes enhance the proliferation and migration of mesenchymal cells, as human dental pulp stem cells, via mitogen-activated protein kinases and Wingless-Int signaling pathways. In addition, they possess proangiogenic potential and contribute to neovascularization and capillary tube formation by promoting endothelial cell proliferation and migration of human umbilical vein endothelial cells. Likewise, they regulate the migration and differentiation of Schwann cells, facilitate the conversion of M1 pro-inflammatory macrophages to M2 anti-inflammatory phenotypes, and mediate immune suppression as they promote regulatory T cell conversion. Basic in vivo studies have indicated that exosomes triggered the regeneration of dentin-pulp–like tissue, and exosomes isolated under odontogenic circumstances are particularly strong inducers of tissue regeneration and stem cell differentiation. Exosomes are a promising regenerative tool for DPC in cases of small pulp exposure or for whole-pulp tissue regeneration.

      • SCIESCOPUSKCI등재

        Effect of Transportation at High Ambient Temperatures on Physiological Responses, Carcass and Meat Quality Characteristics in Two Age Groups of Omani Sheep

        Kadim, I.T.,Mahgoub, O.,AlKindi, A.Y.,Al-Marzooqi, W.,Al-Saqri, N.M.,Almaney, M.,Mahmoud, I.Y. Asian Australasian Association of Animal Productio 2007 Animal Bioscience Vol.20 No.3

        The aim of this study was to determine the effects of short road transportation in an open truck during hot season on live weight shrink, physiological responses, and carcass and meat quality of Omani sheep at 6 and 12 months of age. Thirty-six male sheep, 18 of each age group, were used. Age groups were assigned randomly to transported and not-transported groups. The transported group was transported to the slaughterhouse the day of slaughter in an open truck covering a distance of approximately 100 km. The average temperature during transportation was $37^{\circ}C$. The not-transported group was kept in a lairage of a commercial slaughterhouse with ad libitum feed and water for 48 h prior to slaughter. Blood samples were collected from sheep before loading and prior to slaughter via jugular venipuncture to assess their physiological response to transport in relation to hormonal levels. Animals were weighed just before loading onto a truck and after transport to assess shrinkage. Muscle ultimate pH, expressed juice, cooking loss percentage, WB-shear force value, sarcomere length and colour L*, a*, b* were measured on samples from longissimus dorsi, biceps femoris and semitendinosus muscles collected at 24 h postmortem at $1-3^{\circ}C$. Live weight shrinkage losses were 1.09 and 1.52 kg for 6 and 12 month transported sheep, respectively. The transported sheep had significantly (p<0.05) higher cortisol, adrenaline, noradrenaline, and dopamine concentration levels prior to slaughter at both ages than the not-transported sheep. Transportation significantly influenced meat quality characteristics of three muscles. Muscle ultimate pH and shear force values were significantly higher, while CIE L*, a*, b*, expressed juice and cooking loss were lower in transported than not-transported sheep. Age had a significant effect on meat quality characteristics of Omani sheep. These results indicated that short-term pre-slaughter transport at high ambient temperatures can cause noticeable changes in physiological and muscle metabolism responses in sheep.

      • SCIESCOPUSKCI등재

        Effect of Feed Withdrawal and Heat Acclimatization on Stress Responses of Male Broiler and Layer-type Chickens (Gallus gallus domesticus)

        Mahmoud, Kamel Z.,Yaseen, A.M. Asian Australasian Association of Animal Productio 2005 Animal Bioscience Vol.18 No.10

        This experiment was conducted to evaluate the effect of feed withdrawal (F) and heat acclimatization (A) on malebroiler and -layer chickens responses to acute heat stress (AHS) at four weeks of age. Totals of ninety male chicks of broiler or layer type were randomly allocated into 30 pens of grower batteries with raised wire floors. Chicks were subjected to F and A three times a week through the first three weeks of age. At each time, feed withdrawal and heat acclimatization (T = $35^{\circ}C$) lasted for six and four hours, respectively. Feed consumption (FC), body weight (BW), and feed conversion ratio (FCR) were recorded weekly for broiler type chickens only. At four weeks of age, all groups of chickens were exposed to AHS (T = $39{\pm}1^{\circ}C$) for three hours. Before and after AHS challenge, body temperature (Tb), heterophil (H), and lymphocyte (L) counts were recorded, and H/L ratio was calculated. Antibody (Ab) response to sheep red blood cells (SRBC) was assessed from all treatments without being exposed to AHS. Group F of broiler-type chickens weighed less (p<0.05) compared to control group. Also, both A and F groups of broiler-type chickens consumed less (p<0.05) feed when compared to control group. Acute heat stress elevated Tb of all treatment groups, however the increase was more profound (p<0.001) in broiler chicks. Broiler chicks of both A and F groups showed a tendency to have higher (p = 0.08) Tb when compared to control group. Acute heat stress elevated (p<0.001) H/L ratio in both types of chickens. Broiler chicks maintained higher (p<0.001) H/L ratio. Both F and A groups reduced (p<0.01) the level of elevation in H/L ratio compared to control groups of both types of chickens. Neither A nor F group affected the Ab production in response to SRBC. However, there was a tendency towards higher Ab responses in F group when compared to other groups in both types of chickens. Results of the present study demonstrate that previous history of feed withdrawal or episodes of heat exposures improved chicks'physiological withstanding of AHS and a tendency to improved humoral immune response.

      • A Novel Online Controller for Tuning Shunt Active Power Filters Based Upon Switched-Capacitors

        Ossama M. Elgendy,Ahmed M. A. Mahmoud,A. Abass,A. D. Alkoshairy 전력전자학회 2007 ICPE(ISPE)논문집 Vol.- No.-

        This paper presents a novel online controller for tuning shunt active power filters (APF). The idea of the proposed controller is based upon using a low rating switched-capacitor circuit as online estimator to extract the fundamental reactive component of the nonlinear load current. This reactive component is shifted in appropriate phase using two phase-shifters to obtain a 3φ signal. The line current is sensed and compared instantaneously with this 3φ signal using three comparators. The outputs of the comparators represent each moment the profile of the harmonic current. This harmonic current is taken as a reference signal to drive a simple closed-loop P-I controller in order to produce the necessary modulating signals for the triggering module of the APF. In the case of balanced load, which is the case under investigation in this paper, one switched-capacitor circuit is needed. In spite of being simple and straightforward, the proposed controller will be able to solve the problems arising with the p-q algorithm based controllers.

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