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306 results on '"Salem, Ahmed M."'

53. Interspecies Comparison and Radiation Effect on Pharmacokinetics of BIO 300, a Nanosuspension of Genistein, after Different Routes of Administration in Mice and Non-Human Primates

Author

Salem, Ahmed M., primary, Jackson, Isabel L., additional, Gibbs, Allison, additional, Poirier, Yannick, additional, Newman, Diana, additional, Zodda, Andrew, additional, Vujaskovic, Zeljko, additional, Kaytor, Michael D., additional, Serebrenik, Artur A., additional, Gobburu, Jogarao, additional, and Gopalakrishnan, Mathangi, additional

Published
2022
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57. Reassessing the Pediatric Dosing Recommendations for Unfractionated Heparin Using Real‐World Data: A Pharmacokinetic–Pharmacodynamic Modeling Approach.

Author

Salem, Ahmed M., Niu, Tao, Li, Chao, Moffett, Brady S., Ivaturi, Vijay, and Gopalakrishnan, Mathangi

Subjects
*BIOLOGICAL models, *STATISTICS, *CONFIDENCE intervals, *PEDIATRICS, *PHARMACEUTICAL arithmetic, *DESCRIPTIVE statistics, *HEPARIN, *ELECTRONIC health records, *DATA analysis software, *BLOOD coagulation factors, *DATA analysis
Abstract

Optimal pediatric dosing of unfractionated heparin (UFH) is challenging because of the paucity of clinical outcome and pharmacokinetic–pharmacodynamic (PK/PD) studies in pediatrics. This study aimed to: (i) develop a PK/PD model for UFH, quantified by anti‐factor Xa assay, and the UFH effect, measured by activated partial thromboplastin time (aPTT); and (ii) use simulations to evaluate pediatric UFH infusions for achieving the anti‐factor Xa (0.3–0.7 IU/mL) therapeutic target. Electronic health record data were retrospectively collected from 633 patients aged <19 years admitted to Texas Children's Hospital. The PK/PD model was developed using a 70% (training)/30% (testing) split‐sample approach. A 1‐compartment PK model with linear elimination adequately described the UFH PK. An allometrically scaled body weight on clearance (CL) and volume of distribution (Vd) with an age‐dependent maturation function of extracellular water on Vd were the covariates identified. Comparable with literature, the typical values for CL and Vd were 3.28 L/(h·50 kg) and 8.83 L/50 kg, respectively. A linear model adequately described the UFH–aPTT relationship with an estimated slope of 150 seconds/(IU/mL). Simulations of the currently recommended starting infusions (28 IU/h/kg for pediatrics <1 year old or 20 IU/h/kg for pediatrics >1 year old) showed that the anti‐factor Xa therapeutic target was achieved only in 15.3%, 14.6%, 36.9%, and 45.11% of subjects in the age groups of <1 year, 1–6 years, 6–12 years, and 12–19 years, respectively. In conclusion, the UFH anti‐factor Xa target is not achieved initially, especially in young pediatrics, suggesting the need to optimize UFH dosing to achieve higher therapeutic success. [ABSTRACT FROM AUTHOR]

Published
2022
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60. MHD-mixed convection and mass transfer from a vertical stretching sheet with diffusion of chemically reactive species and space- or temperature-dependent heat source

Author

Abd El-Aziz, Mohamed and Salem, Ahmed M.

Subjects
Heat -- Convection, Sheet-metal -- Properties -- Evaluation, Differential equations -- Evaluation -- Thermal properties -- Chemical properties -- Research, Magnetohydrodynamics -- Research -- Chemical properties -- Thermal properties, Physics, Thermal properties, Evaluation, Chemical properties, Research, Properties
Abstract

Abstract: The influence of chemical reactions on the problem of coupled heat and mass transfer by natural convection from a vertical stretching surface in the presence of a space-or temperature-dependent [...]

Published
2007

68. Detailed Kinetic Modelling for Tar Species Evolution in a Downdraft Gasifier

Author

Salem, Ahmed M. and Paul, Manosh C.

Abstract

Biomass is being used widely for energy production in various ways. One of the main schemes for energy production from biomass is gasification, and a powerful tool for optimising the behaviour of biomass gasifiers and also obtaining the required design for specific working conditions is the modelling. An integrated kinetic model was built by the authors ( [1], and [2]), which enabled to simulate, design and optimise the processes of downdraft biomass gasifiers for the production of high quality syngas. In the current research presented in this paper, the kinetic code has been extended by including detailed chemical mechanisms for the tar evolution and formation inside the gasifier. The model incorporated the evolution of 4 main tar species from pyrolysis to combustion and gasification with the formation and kinetic reaction rates of benzene, naphthalene, toluene, and phenol tar compounds. The effect of varying moisture content (MC) and equivalence ratio (ER) is studied to find out the optimum working conditions leading to the reduction of tar amount in the producer gas from downdraft gasifiers. The results reveals that moderate ER of 0.3, with lower MC

Published
2019

77. Synthesis and Characterization of Cobalt(II) N,N′-Diphenylazodioxide Complexes

Author

Emhoff, Kylin A., primary, Balaraman, Lakshmi, additional, Simpson, Sydney R., additional, Stromyer, Michael L., additional, Kalil, Haitham F., additional, Beemiller, James R., additional, Sikatzki, Philipp, additional, Eshelman, Teya S., additional, Salem, Ahmed M. H., additional, DeBord, Michael A., additional, Panzner, Matthew J., additional, Youngs, Wiley J., additional, and Boyd, W. Christopher, additional

Published
2018
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80. Soluble egg antigen of Schistosoma Haematobium induces HCV replication in PBMC from patients with chronic HCV infection

Author

Tabll Ashraf A, Omran Moataza H, Youssef Samar S, El-Awady Mostafa K, El Garf Wael T, and Salem Ahmed M

Subjects
Infectious and parasitic diseases, RC109-216
Abstract

Abstract Background This study was conducted to examine, in vitro , the effect of soluble egg antigen (SEA) of S. haematobium on intracellular HCV RNA load in peripheral mononuclear cells (PBMC) as well as on cell proliferation in patients with chronic HCV infection. Methods PBMC from 26 patients with chronic HCV infection were cultured for 72 hours in presence and absence of 50 μg SEA/ml medium. Intracellular HCV RNA quantification of plus and minus strands was assessed before and after stimulation. PBMC from five healthy subjects were cultured for 7 days, flow cytometric analysis of DNA content was used to assess the mitogenic effect of SEA on PBMC proliferation compared to phytoheamaglutinine (PHA). Results Quantification of the intracellular viral load showed increased copy number/cell of both or either viral strands after induction with SEA in 18 of 26 patients (69.2%) thus indicating stimulation of viral replication. Flow cytometric analysis showed that mean ± S.D. of percent values of cell proliferation was induced from 3.2 ± 1.5% in un-stimulated cells to 16.7 ± 2.5 % and 16.84 ± 1.7 % in cells stimulated with PHA and SEA respectively. Conclusion the present study supports earlier reports on SEA proliferative activity on PBMC and provides a strong evidence that the higher morbidity observed in patients co-infected with schistosomiasis and HCV is related, at least in part, to direct stimulation of viral replication by SEA.

Published
2006
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81. Improving the catalytic efficiency of thermostable Geobacillus stearothermophilus xylanase XT6 by single-amino acid substitution.

Author

Azouz, Rasha A M, Hegazy, Usama M, Said, Mahmoud M, Bassuiny, Roqaya I, Salem, Ahmed M, and Fahmy, Afaf S

Subjects
GEOBACILLUS stearothermophilus, TURNOVER frequency (Catalysis), POLYMERASE chain reaction, RICE straw, HEMICELLULOSE, ARABINOXYLANS, SEQUENCE analysis
Abstract

Directed evolution using error-prone polymerase chain reaction was employed in the current study to enhance the catalytic efficiency of a thermostable Geobacillus stearothermophilus xylanase XT6 parent. High-throughput screening identified two variants with enhanced activity. Sequencing analysis revealed the presence of a single-amino acid substitution (P209L or V161L) in each variant. The maximum activity of mutant V161L and P209L was at 85°C and 70°C, respectively. Both mutants exhibited maximum activity at pH 7. The thermal and alkaline tolerance of mutant V161L only were markedly improved. The two mutants were more resistant to ethanol inhibition than the parent. Substrate specificity of the two mutants was shifted from beechwood xylan to birchwood xylan. The potential of the two mutants to hydrolyze rice straw and sugarcane bagasse increased. Both turnover number (k cat) and catalytic efficiency (k cat/ k M) increased 12.2- and 5.7-folds for variant P209L and 13- and 6.5-folds for variant V161L, respectively, towards birchwood xylan. Based on the previously published crystal structure of extracellular G. stearothermophilus xylanase XT6, V161L and P209L mutation locate on βα-loops. Conformational changes of the respective loops could potentiate the loop swinging, product release and consequently result in enhancement of the catalytic performance. [ABSTRACT FROM AUTHOR]

Published
2020
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92. FAS and FASL genetic polymorphisms impact on clinical outcome of malignant pleural mesothelioma

Author

El-Hamamsy,Manal, Ghali,Ramy R, Saad,Amr S, Shaheen,Sara M, Salem,Ahmed M, El-Hamamsy,Manal, Ghali,Ramy R, Saad,Amr S, Shaheen,Sara M, and Salem,Ahmed M

Abstract

Manal El-Hamamsy,1 Ramy R Ghali,2 Amr S Saad,2 Sara M Shaheen,1 Ahmed M Salem1 1Department of Clinical Pharmacy, Faculty of Pharmacy, Ain Shams University, Cairo, Egypt; 2Department of Clinical Oncology, Faculty of Medicine, Ain Shams University, Cairo, Egypt Background: FAS-670 A>G (rs1800682) and FASL-844 C>T (rs763110) polymorphisms have been previously correlated with clinical outcome of non-small cell lung cancer (NSCLC) and breast and bladder cancers. We investigated the influence of these polymorphisms on clinical outcome of malignant pleural mesothelioma (MPM) patients.Patients and methods: In this cohort study (NCT02269878), 68 epithelioid MPM Egyptian patients treated with first-line platinum-based chemotherapy were recruited in the period between April 2014 and May 2015. The genotype analysis was performed using TaqMan® single-nucleotide polymorphism genotyping assay. The association between the selected polymorphisms and response rate, progression-free survival (PFS) and overall survival (OS) at 18 months was evaluated.Results: The median age of patients was 55 years and 45.6% of them received platinum in combination with pemetrexed, while 54.4% received platinum in combination with gemcitabine. FASL-844 CC genotype was more common than expected in early-stage tumor (P=0.042). It was found that there was no association between the investigated polymorphisms and response rate or 18-month OS. However, the PFS rate at 18 months for FASL-844 CC genotype carriers was 45% versus 10.6% for FASL-844 CT/TT genotypes carriers (log-rank: 6.2; P=0.013). Also, the number of platinum-based cycles and tumor stage were found to be significant variables for PFS by univariate analysis (P≤0.001 and P=0.006, respectively). Stratified Cox regression showed that the carriers of FASL-844 CT/TT genotypes were still more susceptible to disease progression than carriers of FASL-844 CC genotype (adjusted HR =3.77, 95% CI: 1.34–10.62

Published
2016

93. The Airport Gate Assignment Problem: A Survey

Author

Bouras, Abdelghani, Ghaleb, Mageed A., Suryahatmaja, Umar S., and Salem, Ahmed M.

Subjects
Article Subject
Abstract

The airport gate assignment problem (AGAP) is one of the most important problems operations managers face daily. Many researches have been done to solve this problem and tackle its complexity. The objective of the task is assigning each flight (aircraft) to an available gate while maximizing both conveniences to passengers and the operational efficiency of airport. This objective requires a solution that provides the ability to change and update the gate assignment data on a real time basis. In this paper, we survey the state of the art of these problems and the various methods to obtain the solution. Our survey covers both theoretical and real AGAP with the description of mathematical formulations and resolution methods such as exact algorithms, heuristic algorithms, and metaheuristic algorithms. We also provide a research trend that can inspire researchers about new problems in this area.

Published
2014
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