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Nahla H. Barakat,Sana H. Barakat,Nadia Ahmed 대한의료정보학회 2019 Healthcare Informatics Research Vol.25 No.3
Objectives: The aim of this study is to develop an intelligent diagnostic system utilizing machine learning for data cleansing, then build an intelligent model and obtain new cutoff values for APRI (aspartate aminotransferase-to-platelet ratio) and FIB- 4 (fibrosis score) for the prediction and staging of fibrosis in children with chronic hepatitis C (CHC). Methods: Random forest (RF) was utilized in this study for data cleansing; then, prediction and staging of fibrosis, APRI and FIB-4 scores and their areas under the ROC curve (AUC) have been obtained on the cleaned dataset. A cohort of 166 Egyptian children with CHC was studied. Results: RF, APRI, and FIB-4 achieved high AUCs; where APRI had AUCs of 0.78, 0.816, and 0.77; FIB- 4 had AUCs of 0.74, 0.828, and 0.78; and RF had AUCs of 0.903, 0.894, and 0.822, for the prediction of any type of fibrosis, advanced fibrosis, and differentiating between mild and advanced fibrosis, respectively. Conclusions: Machine learning is a valuable addition to non-invasive methods of liver fibrosis prediction and staging in pediatrics. Furthermore, the obtained cutoff values for APRI and FIB-4 showed good performance and are consistent with some previously obtained cutoff values. There was some agreement between the predictions of RF, APRI and FIB-4 for the prediction and staging of fibrosis.
Barakat, Assem,Al-Majid, Abdullah Mohammed,Al-Qahatany, Faisal M.,Islam, Mohammad Shahidul,Al-Agamy, Mohamed H.M. Korean Chemical Society 2014 Bulletin of the Korean Chemical Society Vol.35 No.2
In this work, synthesis, characterization and antimicrobial activity of series of imidazolines-oxazolines scaffolds 5a-f and 10a-d have been investigated. All the imidazolines-oxazolines derivatives were prepared from acid derivatives 1 and 6a-c, and enantiomerically pure (S)-2-amino-3-methyl-1-butanol in four steps with excellent optical purity. The structures of all newly synthesized compounds have been elucidated by $^1H$, $^{13}C$ NMR, GCMS, and IR spectrometry. Their purity was confirmed using elemental analysis. Some newly synthesized compounds were examined to in-vitro antimicrobial activity. Among the prepared products 10d was found to exhibits the most active against all tested bacteria and fungi with minimal inhibitory concentration (MIC) ranged between 21.9 and $42.6{\mu}g/mL$.
Barakat, N.A.M.,Motlak, M.,Ghouri, Z.K.,Yasin, A.S.,El-Newehy, M.H.,Al-Deyab, S.S. Elsevier 2016 Journal of molecular catalysis Chemical Vol.421 No.-
<P>Among the various carbonaceous materials, graphene is highly considered to provide the optimum support for the electrocatalytic materials due to its excellent electrical conductivity and extremely large surface area. In literature, based on our best knowledge, few studies have been reported to introduce effective electrocatalysts for urea oxidation. In this study, Ni-decorated graphene sheets are introduced as effective and stable electrocatalyst for urea oxidation. The introduced composite was prepared by reflux of graphene oxide with nickel acetate at 120 degrees C for 10h followed by calcination in argon atmosphere at 850 degrees C for 2 h. X-ray diffractometer (XRD), transmission electron microscope (TEM) and Raman spectroscopy techniques confirmed formation of graphene sheets decorated by nickel nanoparticles. The synthesized Ni-decorate graphene shows distinct electrocatalytic activity toward urea oxidation. Numerically, using 2 M urea solution (in 1 M KOH) the corresponding current density was 150 mAcm(-2) (2100 mAcm(-2) g(-1)) with clear urea oxidation peaks in the forward and reverse scans. Study the influence of metal loading indicated that the amount of nickel nanoparticles should be optimized as the best performance has been observed when equal amounts of nickel acetate and graphene oxides were utilized during the preparation process. The introduced decorated graphene reveals good stability at various applied voltages. Overall, the study emphasizes the advantage of using graphene as support to distinctly enhancing urea electrooxidation. (C) 2016 Elsevier B.V. All rights reserved.</P>
A NOTE ON THE CONVERGENCE OF TRIVARIATE EXTREME ORDER STATISTICS AND EXTENSION
BARAKAT, H. M.,NIGM, E. M.,ASKAR, M. M. 한국전산응용수학회 2005 Journal of applied mathematics & informatics Vol.18 No.1
Necessary and sufficient conditions, under which there exists (at least) a sequence of vectors of real numbers for which the distribution function (d.f.) of any vector of extreme order statistics converges to a non-degenerate limit, are derived. The interesting thing is that these conditions solely depend on the univariate marginals. Moreover, the limit splits into the product of the limit univariate marginals if all the bivariate marginals of the trivariate d.f., from which the sample is drawn, is of negative quadrant dependent random variables (r.v.'s). Finally, all these results are stated for the multivariate extremes with arbitrary dimensions.
Asymptotic behavior of the record value sequence
Barakat, H.M. 한국통계학회 2012 Journal of the Korean Statistical Society Vol.41 No.3
The class of limit distribution functions of the random record model is fully characterized. Necessary and sufficient conditions as well as the domains of attraction of the limit distribution functions are obtained.
CONTINUATION THEOREMS OF THE EXTREMES UNDER POWER NORMALIZATION
Barakat, H.M.,Nigm, E.M.,El-Adll, M.E. 한국전산응용수학회 2002 Journal of applied mathematics & informatics Vol.10 No.1
In this paper an important stability property of the extremes under power normalizations is discussed. It is proved that the restricted convergence of the Power normalized extremes on an arbitrary nondegenerate interval implies the weak convergence. Moreover, this implication, in an important practical situation, is obtained when the sample size is considered as a random variable distributed geometrically with mean n.
Barakat Mohamed,Donkol Ahmed,Hamed Hesham F. A.,Salama Gerges M. 대한전기학회 2021 Journal of Electrical Engineering & Technology Vol.16 No.4
This paper presents a new optimization tool-based population parameter called Harris hawks optimizer (HHO) and its application study to fi ne-tune the gains of well-designed proportional-derivative proportional-integral (PD-PI) cascade control to suppress the load frequency control (LFC) issues. The HHO based PID and PD-PI controllers are broadly implemented at two models with many circumstances for each model to ensure the eff ectiveness and the robustness of the proposed scheme at a high load disturbance, nonlinearity, and some critical parameters associated with the interconnected power system. First, a two-area non-reheat power plant is implemented, and the gains of PID and PD-PI controllers are adjusted using the proposed algorithm. In order to introduce extra realistic challenges, the governor-dead band is also modeled to ensure the robustness of the HHO/PD-PI in handling nonlinearity properties. Furthermore, to guarantee the suitability of the proposed HHO/PD-PI, a model with a mixture of power plants is carried out with and without the HVDC link, which is raised for the practical problems of LFC. Simulation results proved that; the proposed techniques HHO/PID and HHO/PD-PI provide superior performance compared to other reported strategies such as DE/PID, TLBO/PID, IGWO/PID, multi-objective/PID, and TLBO/2DOF-PID controllers. Finally, the dynamic investigation has also been completed using the random load pattern in system model-2, which shows the superior performance of HHO/PID and HHO/PD-PI schemes.
Barakat, N.A.M.,Park, S.J.,Khil, M.S.,Kim, H.Y. Elsevier 2009 Materials science and engineering B. Advanced Func Vol.162 No.3
In the present study, manganese monoxide (MnO) which is hard to prepare because of the chemical activity of the manganese metal has been synthesized in nanofibrous form. An electrospun manganese acetate/poly(vinyl alcohol) nanofiber mats have been hydrothermally treated by novel strategy. The treatment process was based on producing of water gas (Co and H<SUB>2</SUB>) to eliminate the polymer and reduced the manganese acetate to manganese monoxide. The process was carried out by heating the dried nanofiber mates at 400<SUP>o</SUP>C for 3h in an especial designed reactor in which a stream of water vapor was passing through a bed of an activated carbon. The obtained physiochemical characterization results indicated that the proposed hydrothermal treatment process does have the ability to produce pure MnO nanofibers with good crystallinity.
Barakat, Heba H.,Nada, Somaia A. The Korean Society of Pharmacognosy 1996 Natural Product Sciences Vol.2 No.2
A new natural product, 3,4,8-trihydroxybenzopyranopyran-6,9-dione was isolated from the aqueous ethanolic gall extract of Tamarix aphylla (Tamaricaceae) along with the known phenolics, monodecarboxyellagic acid and brevifolin carboxylic acid as well. The structures have been established by ESI-MS, $^1H$ and $^{13}C$ NMR spectral analysis. Antiinflammatory, antipyretic and ulcerogenic activities determination for both plant (Tamarix aphylla and Phragmites australis) were carried out on aq. ethanolic of extracts.