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Fatma M. Abdel Bar,Dina S. Ibrahim,Sahar R. Gedara,Mohammed S. Abdel-Raziq,Ahmed M. Zaghloul 한국생약학회 2018 Natural Product Sciences Vol.24 No.4
The root-knot nematode, Meloidogyne incognita caused a serious damage to many plants. The phenolic components of the leaves of Schinus terebinthifolius were investigated as potential nematicidal agents for M. incognita. Nine compounds were isolated and characterized as viz., 1,2,3,4,6-pentagalloyl glucose (1), kaempferol-3-O-a-L-rhamnoside (Afzelin) (2), quercetin-3-O-a-L-rhamnoside (Quercetrin) (3), myricetin (4), myricetin-3-O-a-L-rhamnoside (Myricetrin) (5), methylgallate (6), protocatechuic acid (7), quercetin (8), and gallic acid (9) using nuclear magnetic resonance (NMR) spectroscopy. Compound 1 showed pronounced nematicidal activity compared to Oxamyl as a positive control. It showed the lowest eggs-hatchability (34%) and the highest mortality in nematode population (21% after 72 hours of treatment) at a concentration of 200 mg/mL. It exhibited the best suppressed total nematode population, root galling and number of eggmasses in infected tomato plants. The total carbohydrates and proteins were also significantly induced by 1 with reduction in total phenolics and increase in defense-related proteins. Thus, compound 1 could be a promising, more safe and effective natural nematicidal agent for the control of root-knot nematodes.
Storage Proteins of Diamondback Moth, Plutella xylostella: Purification and Expression Profile
Ibrahim Ahmed M.A.,Lee Kee-Woo,Lee Hyuk-Soo,Kim Yong-Gyun Korean Society of Applied Entomology 2006 Journal of Asia-Pacific Entomology Vol.9 No.2
Storage proteins (SPs) were significantly detected in the hemolymph during the late instar larvae of diamondback moth, Plutella xylostella. These SPs were resolved into three proteins (SP1, SP2, and SP3) at 7% SDS-PAGE. Their apparent molecular sizes were around 80 kDa. SP1 was synthesized later than SP2 and SP3 during the development of the last instar. Total soluble proteins of last instar larvae were extracted and fractionated sequentially with ammonium sulfate, size-exclusion chromatography, and ion-exchange chromatography. The SPs were purified and their developmental expression was discussed.
Vibration analysis of cracked frame structures
Ibrahim, Ahmed M.,Ozturk, Hasan,Sabuncu, Mustafa Techno-Press 2013 Structural Engineering and Mechanics, An Int'l Jou Vol.45 No.1
In this study, the effects of crack depth and crack location on the in-plane free vibration of cracked frame structures have been investigated numerically by using the Finite Element Method. For the rectangular cross-section beam, a crack element is developed by using the principles of fracture mechanics. The effects of crack depth and location on the natural frequency of multi-bay and multi-store frame structures are presented in 3D graphs. The comparison between the present work and the results obtained from ANSYS shows a very good agreement.
Ahmed M.A. Ibrahim,Lamia A. ALRAKAN,Saleh Ahmed ALAIFAN 한국곤충학회 2015 Entomological Research Vol.45 No.5
Female mosquitoes feed on human blood, which can be collected to analyze human short tandem repeat (STR) sequences; these are specific to each human individual. Analysis of STRs might help in identification of a person found near a crime scene. Aedes aegypti and Culex pipiens mosquitoes fed on human blood were cultured at 18°C or 40°C (median temperature for summer and winter time in Riyadh governorate, Saudi Arabia) for 3, 6, 12, 24, 48 and 72 h. In A. aegypti, human DNA concentration was reduced with time at both temperatures. At 18°C, we obtained full STR profiles up to 48 h post feeding on human blood while none of the 16 loci were obtained at 72 h. At 40°C, we missed six sites at 12 h after blood sucking, 12 at 24 h, and 15 at 48 h and 72 h. In C. pipiens cultured at 18°C, full profiles were developed up to 48 h following blood feeding while we could not amplify five sites at 72 h. At 40°C, mortality among females was 50% at 24 h and 100% at both 48 h and 72 h; however, we had full profiles in all samples including dead insects. This research addressed the possibility of using mosquitoes in forensic research by DNA genotyping by changing the mosquito culturing temperature and mosquito genus. Our findings proved that different types of mosquito change the temporal pattern of STR analysis and showed that the mosquito culturing temperature affects the integrity of DNA for STR analysis.
Vibration analysis of cracked frame structures
Ahmed M. Ibrahim,Hasan Ozturk,Mustafa Sabuncu 국제구조공학회 2013 Structural Engineering and Mechanics, An Int'l Jou Vol.45 No.1
In this study, the effects of crack depth and crack location on the in-plane free vibration of cracked frame structures have been investigated numerically by using the Finite Element Method. For the rectangular cross-section beam, a crack element is developed by using the principles of fracture mechanics. The effects of crack depth and location on the natural frequency of multi-bay and multi-store frame structures are presented in 3D graphs. The comparison between the present work and the results obtained from ANSYS shows a very good agreement.
Ahmed Raza,Ibrahim M. Al-Shahwan,Omer A. Abdalla,Mohammed A. AL-Saleh,Mahmoud A. Amer 한국식물병리학회 2017 Plant Pathology Journal Vol.33 No.1
A survey was conducted to determine the status ofLucerne transient streak virus (LTSV) in three highyieldingalfalfa regions in central Saudi Arabia (Riyadh,Qassim, and Hail) during 2014. Three hundredand eight symptomatic alfalfa, and seven Sonchus oleraceussamples were collected. DAS-ELISA indicatedthat 59 of these samples were positive to LTSV. Twoisolates of LTSV from each region were selected formolecular studies. RT-PCR confirmed the presence ofLTSV in the selected samples using a specific primerpair. Percentage identity and homology tree comparisonsrevealed that all Saudi isolates were more closelyrelated to each other but also closely related to the Canadianisolate-JQ782213 (97.1–97.6%) and the NewZealand isolate-U31286 (95.8–97.1%). ComparingSaudi isolates of LTSV with ten other sobemovirusesbased on the coat protein gene sequences confirmedthe distant relationship between them. Eleven out offourteen plant species used in host range study werepositive to LTSV. This is the first time to documentthat Trifolium alexandrinum, Nicotiana occidentalis,Chenopodium glaucum, and Lathyrus sativus are newhost plant species for LTSV and that N. occidentalisbeing a good propagative host for it.
Ibrahim Hairul-Islam Mohamed,Ahmed Emad A.,Alzahrani Abdullah M.,Sayed Abdullah A.,Hanieh Hamza 한국응용생명화학회 2022 Applied Biological Chemistry (Appl Biol Chem) Vol.65 No.2
Multiple sclerosis (MS) is a degenerative autoimmune disease attacks the myelin sheath of the central nervous system (CNS) neurons causing different disabilities. According to recent evidence, the main bioactive component in Enicostema axillare , the Swrtiamarin (SM) has been found to exert anti-inflammatory and antioxidant activities against several diseases. However, SM activities in treatment of autoimmune diseases remain to be explored. Herein, we used a murine model of MS, to show that SM treatment ameliorates the severity of experimental autoimmune encephalomyelitis (EAE). This occurs through reducing the levels of pro-inflammatory cytokines and infiltration of CD4+CD45+ cells into CNS. That was associated with a reduction in the expression of STAT3 and NFkB in CD4+ T cells under Th17 and LPS-stimulated macrophages. Furthermore, in silico studies revealed that SM interacts with NF-E2-related factor 2 (NRF2), and therefore, suppressed oxidative stress by inducing formation NRF2-antioxidant response element (ARE) complex. We found that SM is an agonist of NRF2 complex regulating the total CD4 population and antioxidant markers in EAE mice. Molecular docking analysis showed a stable and higher binding affinity between SM and NRF2. Results revealed that SM treatment increased the complex formation between ARE and NRF2 where immunoprecipitation methods showed a higher binding affinity of ARE to NRF2 in SM treated animals. Complex formation triggered ARE cascade of antioxidant gene clusters and reduces the MS pathological alterations in EAE mice model. Current data proposed SM as an effective biomolecule in treatment of MS and controlling neuronal damage through inhibiting oxidative stress markers and targeting NRF2.
Precepitation and purification of amylase enzyme produced by streptomyces aureofaciens 77
Ibrahim, A.N.,Ahmed, F.H.,Ibrahim, M.M.K.,Arafa, M.A.I. The Pharmaceutical Society of Korea 1990 Archives of Pharmacal Research Vol.13 No.1
Precipitation and purification of amylase secreted by Streptomyces aureofaciens 77 in liquid inorganic salts-starch medium under the optimum conditions were carried out. Ammonium sulphate fractionation was used to precipitate amylase in cell free culture filtrate. (NH/sub 4/)/sub 2/ SO/sub 4/ at a concentration of 50-70% saturation gave the highest enzyme yield. The obtained precipitates were redissolved in phosphate buffer (pH 7.0) and subjected to dialysis. The dialyzed enzyme preparation was applied to DEAE-cellulose column chromatography which resulted in an increase of purification up to 59.48 fold. A further step of purification was done by applying the obtained purified sample to Sephadex-G200 column chromatography which resulted in ann increase of purification up to 73. 92 fold. The results clearly indicated that the isolated amylase from S. aureofaciens 77 was only on type.
Activity and stability of purified amylase produced by streptomyces aureofaciens 77
Ibrahim, A.N.,Ahmed, F.H.,Ibrahim, M.M.K.,Arafa, M.A.I. The Pharmaceutical Society of Korea 1990 Archives of Pharmacal Research Vol.13 No.1
The effects of pH values, temperature and some elements on the amylolytic activity and stability of the purified S. aureofacienc 77 amylase were studied in this investigation. The purified enzyme showed its maximum activity at pH 6 within 8 min incubation at $40^{\circ}C$. None of the tested 6 metals showed on stimulatory effect on the enzymatic activity, $Fe^{+++}$, $Cu^{++}$ and $Hg^{++}$ at high dose inhibited the enzyme activity to great extent as compared with $Zn^{++}$, $Mn^{++}$ and $Fe^{++}$ whih gave less effect in this respect. The enzyme liquor was found to be thermolabile, since it lost completely its activity after 4 days incubation under room temperature and showed maximum activity during this period as a result of additions of $Ca^{++}$and NaCl, Gradual reduction was however recorded until activity reached 30% after 60 days of incubation.