Cloning and Expression of Two Protein Tyrosine Phosphatase Genes Encoded in Cotesia plutellae Bracovirus Genome

Ibrahim Ahmed M. A.,Je Yeon-Ho,Kim Yong-Gyun 한국응용곤충학회 2005 한국응용곤충학회 학술대회논문집 Vol.2005 No.05

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.

Behaviour and design of guyed pre-stressed concrete poles under downbursts

Ahmed M. Ibrahim,Ashraf A. El Damatty 한국풍공학회 2019 Wind and Structures, An International Journal (WAS Vol.29 No.5

Pre-stressed concrete poles are among the supporting systems used to support transmission lines. It is essential to protect transmission line systems from harsh environmental attacks such as downburst wind events. Typically, these poles are designed to resist synoptic wind loading as current codes do not address high wind events in the form of downbursts. In the current study, the behavior of guyed pre-stressed concrete Transmission lines is studied under downburst loads. To the best of the authors’ knowledge, this study is the first investigation to assess the behaviour of guyed pre-stressed concrete poles under downburst events. Due to the localized nature of those events, identifying the critical locations and parameters leading to peak forces on the poles is a challenging task. To overcome this challenge, an in-house built numerical model is developed incorporating the following: (1) a three-dimensional downburst wind field previously developed and validated using computational fluid dynamics simulations; (2) a computationally efficient analytical technique previously developed and validated to predict the non-linear behaviour of the conductors including the effects of the pretension force, sagging, insulator’s stiffness and the non-uniform distribution of wind loads, and (3) a non-linear finite element model utilized to simulate the structural behaviour of the guyed pre-stressed concrete pole considering material nonlinearity. A parametric study is conducted by varying the downbursts locations relative to the guyed pole while considering three different span values. The results of this parametric study are utilized to identify critical downburst configurations leading to peak straining actions on the pole and the guys. This is followed by comparing the obtained critical load cases to new load cases proposed to ASCE-74 loading committee. A non-linear failure analysis is then conducted for the three considered guyed pre-stressed concrete transmission line systems to determine the downburst jet velocity at which the pole systems fail.

Temporal analysis of 16 STR loci in human blood drawn from two culicid mosquitoes cultured at different temperatures

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.

Mineralogical studies and extraction of some valuable elements from sulfide deposits of Abu Gurdi area, South Eastern Desert, Egypt

Ibrahim A. Salem,Gaafar A. El Bahariya,Bothina T. El Dosuky,Eman F. Refaey,Ahmed H. Ibrahim,Amr B. ElDeeb 한국분석과학회 2024 분석과학 Vol.37 No.1

Abu Gurdi area is located in the South-eastern Desert of Egypt which considered as volcanic massivesulfide deposits (VMS). The present work aims at investigating the ore mineralogy of Abu Gurdi region inaddition to the effectiveness of the hydrometallurgical route for processing these ores using alkaline leachingfor the extraction of Zn, Cu, and Pb in the presence of hydrogen peroxide, has been investigated. The factorsaffecting the efficiency of the alkaline leaching of the used ore including the reagent composition, reagentconcentration, leaching temperature, leaching time, and Solid /Liquid ratio, have been investigated. It was notedthat the sulfide mineralization consists mainly of chalcopyrite, sphalerite, pyrite, galena and bornite. Gold isdetected as rare, disseminated crystals within the gangue minerals. Under supergene conditions, secondary copperminerals (covellite, malachite, chrysocolla and atacamite) were formed. The maximum dissolution efficienciesof Cu, Zn, and Pb at the optimum leaching conditions i.e., 250 g/L NaCO3 - NaHCO3 alkali concentration,for 3 hr., at 250℃, and 1/5 Solid/liquid (S/L) ratio, were 99.48 %, 96.70 % and 99.11 %, respectively. Anapparent activation energy for Zn, Cu and Pb dissolution were 21.599, 21.779 and 23.761 kJ.mol−1, respectively,which were between those of a typical diffusion-controlled process and a chemical reaction-controlled process. Hence, the diffusion of the solid product layer contributed more than the chemical reaction to control the rateof the leaching process. High pure Cu(OH)2, Pb(OH)2, and ZnCl2 were obtained from the finally obtained leachliquor at the optimum leaching conditions by precipitation at different pH. Finally, highly pure Au metal wasseparated from the mineralized massive sulfide via using adsorption method.

Evolution of Diastolic Dysfunction in Patients with Coronary Slow Flow Phenomenon and Acute Non-ST Segment Elevation Myocardial Infarction

Ahmed El Zayat,Mahmoud Abdelaziz,Ahmed Yousry,Ismail Ibrahim 한국심초음파학회 2021 Journal of Cardiovascular Imaging (J Cardiovasc Im Vol.29 No.4

BACKGROUND: Diastolic function has been reported to be impaired in many patients with coronary slow flow phenomenon (CSFP). CSFP has broad spectrum of clinical presentations, including non-ST elevation myocardial infarction (NSTEMI). We sought to study the short-term evolution of diastolic function in CSFP patients presenting with NSTEMI. METHODS: This study included 92 patients with CSFP and acute NSTEMI. Conventional echocardiography Doppler imaging and tissue Doppler echocardiography imaging were used to evaluate diastolic function during index NSTEMI and after 3 months. RESULTS: Mean age of study patients was 45.7 ± 6.8 years. The prevalence of diastolic dysfunction (DD) at baseline was 69 patients (75%) and 28 patients (30.4%) at 3 months, p < 0.001. Various diastolic function indices showed significant improvement from baseline to 3 months follow-up. E/Em was 17.32 ± 3.41 at baseline compared to 12.41 ± 5.58 at 3 months, p = 0.039. Septal e′ velocity was 5.67 ± 4.56 cm/s at baseline compared to 7.78 ± 3.22 cm/s at 3 months, p = 0.023. Medications used were not significantly different between those with improved versus unimproved DD. CONCLUSIONS: Diastolic function seems to improve over short-term follow-up in patients with CSFP presenting with NSTEMI. This could reflect a transient worsening during acute NSTEMI.

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.

Structure and Expression Profiles of Two Putative Cotesia plutellae Bracovirus Genes (CpBV-H4 and CpBV-E94α) in Parasitized Plutella xylostella

Ahmed M. A. Ibrahim,최재영,Yeon Ho Je,Yonggyun Kim 한국응용곤충학회 2005 Journal of Asia-Pacific Entomology Vol.8 No.4

Endoparasitoid wasp, Cotesia plutellae, parasitizes diamondback moth, Plutella xylostella, and interrupts host development and immune processes. Its obligate symbiotic virus, C. plutellae bracovirus (CpBV), has been regarded as a major source of interrupting the physiological alteration during the parasitization. On the process of genome sequencing of CpBV, two putative genes were detected and homologous to E94 of baculovirus and histone H4 subunit of a nucleosome, respectively. The open reading frame of CpBV-E94α was 642 bp encoding 214 amino acid residues, while that of CpBV-H4 was 423 bp encoding 141 amino acid residues. Both genes were on the same segment of CpBV genome. They were expressed only in the P. xylostella parasitized by C. plutellae in which all three tissues of hemocytes, fat body, and gut expressed both genes. Quantitative RT-PCR analyses indicated that their expression patterns in the parasitized host were similar and exhibited bimodal peaks at early and late parasitization periods. We discussed their physiological functions based on the gene structures.

Structure and Expression Profiles of Two Putative Cotesia plutellae Bracovirus Genes (CpBV-H4 and CpBV-$E94{\alpha}$) in Parasitized Plutella xylostella

Ibrahim Ahmed M.A.,Choi, Jae-Young,Je, Yeon-Ho,Kim, Young-Gyun Korean Society of Applied Entomology 2005 Journal of Asia-Pacific Entomology Vol.8 No.4

Endoparasitoid wasp, Cotesia plutellae, parasitizes diamondback moth, Plutella xylostella, and interrupts host development and immune processes. Its obligate symbiotic virus, C. plutellae bracovirus (CpBV): has been regarded as a major source of interrupting the physiological alteration during the parasitization. On the process of genome sequencing of CpBV, two putative genes were detected and homologous to E94 of baculovirus and histone H4 subunit of a nucleosome, respectively, The open reading frame of CpBV-$E94{\alpha}$ was 642 bp encoding 214 amino acid residues, while that of CpBV-H4 was 423 bp encoding 141 amino acid residues. Both genes were on the same segment of CpBV genome. They were expressed only in the p. xyiostella parasitized by C, plutellae in which all three tissues of hemocytes, fat body, and gut expressed both genes. Quantitative RT-PCR analyses indicated that their expression patterns in the parasitized host were similar and exhibited bimodal peaks at early and late parasitization periods. We discussed their physiological functions based on the gene structures.

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.