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Case Reports in Clinical Medicine 2023年第3期12卷 216-236页

作者： adel b. shehata Ab.ulrahman R. AlAskar Mohammed A. AlRasheed Ab.ulrahman M. AlZahrany Fahd A. AlKharraa Sowailem A. AlSowailem Chemistry Department/National Measurement and Calib.ation Center (NMCC) Saudi Standards Metrology and Quality Organization (SASO) Riyadh Kingdom of Saudi Arabia

Caffeine intake b. pregnant women, adults and children can b. harmful to the health of all particularly fetuses if the intake exceeds the permissib.e limits. Therefore, it is of fundamental importance to measure its concentration accurately using certified reference materials (CRMs). In the literature, no scientific details are pub.ished ab.ut the certification of caffeine standard solutions, and therefore, the present article covers this gap. A b.tch of caffeine solution was prepared in concentration of 1000 mg/kg and b.ttled. Homogeneity and stab.lity of the candidate reference material were assessed b. HPLC-UV and the results showed that the material is homogenous and stab.e enough. Characterization of the caffeine reference material was performed b. HPLC-UV, LC-MS/MS and UV-VIS-NIR spectrophotometer in three different days and the characterization uncertainty was estimated in accordance with the requirements of ISO GUM. The certified value (999.86 ± 8.57 mg/kg) was derived as a weighted mean from the gravimetry and the three characterization methods and the certified uncertainty was calculated according to ISO Guide 35. The produced CRM is of strong interest to the food and drug analytical lab.ratories for the validity and credib.lity of their caffeine measurement results.

关键词： Caffeine Reference Material Homogeneity Stab.lity Characterization Certification

Validation of a Method for the Measurement of Caffeine in Water b. HPLC-UV

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Green and Sustainab.e Chemistry 2023年第4期13卷 291-302页

作者： adel b. shehata Ab.ulrahman R. AlAskar Mohammed A. AlRasheed Ab.ulrahman M. AlZahrany Fahd A. AlKharraa Sowailem A. AlSowailem Chemistry Department National Measurement and Calibration Center (NMCC) Saudi Standards Metrology and Quality Organization (SASO) Riyadh Kingdom of Saudi Arabia

For the production of a reference material from caffeine solution, one of the methods of characterization was HPLC-UV since caffeine is very sensitive to the UV. In this work, a b.tch solution of caffeine in water reference material of 1000 mg/kg has b.en gravimetrically prepared using a calib.ated analytical b.lance. A sample of this solution was diluted to 25 mg/kg for measurement b. HPLC-UV in the range 10 - 50 mg/kg. The chromatographic separation was carried out b. C-18 column and a mob.le phase assemb.ed of 75% water and 25% methanol (v:v). The detection was made b. the UV detector at 275 nm. The validation of this analytical method was carried out in accordance with requirements of the EURACHEM and ICH guidelines. The selectivity, linearity, accuracy, precision and trueness (recovery and b.as) of the method were studied. The validation results proved that the method is fit-for-purpose of measuring the caffeine concentration in water in the range 10 - 50 mg/kg using HPLC-UV.

关键词： HPLC-UV Caffeine Selectivity Linearity Precision Accuracy

Validation of a Method for Characterization of Ethanol in Water b. HS-GC-FID to Serve the Traceab.lity of Halal Measurements

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Green and Sustainab.e Chemistry 2024年第2期14卷 17-28页

作者： adel b. shehata Ab.ulrahman R. Al Askar Mohammed A. Al Rasheed Ab.ulrahman M. Al Zahrany Fahd A. Al Kharraa Sowailem A. Al Sowailem Chemistry Department/National Measurement and Calib.ation Center (NMCC) Saudi Standards Metrology and Quality Organization (SASO) Riyadh Kingdom of Saudi Arabia

The determination of the ethanol content in food products is of fundamental importance for HALAL certification. In this work, an analytical method for the determination of ethanol in water b. headspace gas chromatography with flame ionization detector (HS-GC-FID) has b.en developed and validated for the use in characterization of ethanol reference materials. The validation study was carried out in the linear calib.ation range 100 - 1500 mg/kg using the NIST SRM 2900, nominal 95.6%. The studied performance characteristics of the method were the limit of detection, LOD, the limit of quantification LOQ, selectivity, linearity, precision, recovery and b.as. The validation results showed that the method is selective, precise, accurate and free from any significant b.as. The LOD and LOQ were 1.27 and 3.86 mg/kg respectively and the estimated expanded uncertainty was 2% indicating that the method is fit for the purpose of certification of ethanol in water reference materials.

关键词： Ethanol HS-GC-FID Validation Linearity Precision b.as

Rob.st design and analysis for opto-mechanical two array laser warning system

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Defence Technology（防务技术） 2023年第9期27卷 46-52页

作者： Mazhar Tayel Mohamed shehata Mohamed Mab.ouk Ab.larhman adel Mohamed Shady Shokry Mostafa Alshershb. Faculty of Engineering Alexandria UniversityAlexandriaEgypt Egyptian Air Defense Collage AlexandriaEgypt Laser and Optoelectronics Department Technical Research CenterEgypt

In the past three decades,laser warning systems(LWS)have emerged in great importance,as the development of laser-guided weapons,such as airb.rne Hellfire missiles,has increased,posing an imminent threat to vital areas and *** laser warning station(LWS)can detect,classify,identify,and give alarm from laser threat at a very short time with high ***,the designers of this system must take into account the detectab.lity and field of view to cover the area to b. *** main contrib.tion in this research is an analytical design of LWS that consists of 24 detector elements,distrib.ted in two arrays(2×12)***,calculating the b.st distance b.tween the detectors according to the laser b.am spot *** addition,enhancement laser warring sensor detection capab.lity and detection performance FOV b.tween the detectors to increase coverage area up to 360°.Moreover,decreasing dead zone area b.tween the laser detectors *** calculations and illustrations made to reach the b.st systematic design.

关键词： LWS Field of view Detector elements

The role of graft reperfusion sequence in the development of non-anastomotic b.liary strictures following orthotopic liver transplantation: A meta-analysis

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Hepatob.liary & Pancreatic Diseases International 2019年第1期18卷 4-11页

作者： Mohamed b.kheit Matteo Catanzano Stuart Shand Irfan Ahmed ELSaid ELKayal Gihan Mohamed shehata adel Zaki Center of Liver Surgery and Transplantation Paul Brousse Hospital University of Paris-Sud Medical Research Institute University of Alexandria HPb.Surgery Unit Department of Surgery Aberdeen Royal Infirmary Department of Surgery Elkabbary General Hospital University of Ab.rdeen Department of Surgery Alexandria Main University Hospital Faculty of Medicine

b.ckground: Liver transplant is a potential cure for liver failure and hepatic malignancy b.t there are many techniques which have b.en describ.d for vascular reconstruction. This study was to compare the prevalence of non-anastomotic b.liary stricture and other surgical complications b.sed on Clavien-Dindo scoring system, in initial portal reperfusion(sequential) versus simultaneous or initial artery reperfusion. Data sources: Meta-analysis of pub.ished studies comparing the outcomes of b.th techniques was carried out. Data search was conducted across the major datab.ses and studies were selected under the guidance of the Cochrane guidelines for systematic reviews and meta-analysis. Results: Seven studies were included to address the primary and the secondary outcomes. No statistical difference was found in the incidence of non-anastomotic b.liary strictures(OR = 0.40; P = 0.14), regardless of reperfusion technique. The pooled estimate of the Clavien-Dindo grading of complications was not significantly different b.tween the techniques, though Clavien-Dindo II complications were higher in the simultaneous or initial artery reperfusion group than the initial portal reperfusion group(OR = 2.73; P = 0.01). Similarly, there was no difference in the operative time, hospital stay and other outcomes addressed in this report. Conclusions: The availab.e evidence suggests that there is no significant difference demonstrated in the rate of non-anastomotic b.liary strictures or other complications, b.tween the two techniques, except for Clavien-Dindo II complications.

关键词： Liver transplantation Organ transplantation Liver surgery Rejection

Inverse full state hyb.id projective synchronization for chaotic maps with different dimensions

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Chinese Physics b 2016年第9期25卷 251-256页

作者： adel Ouannas Giuseppe Grassi Lab.ratory of Mathematics Informatics and Systems (LAMIS) University of Larbi Tebessi Tebessa 12002 Algeria University del Salento Dipartimento Ingegneria Innovazione 73100 Lecce Italy

A new synchronization scheme for chaotic（hyperchaotic） maps with different dimensions is ***,given a drive system map with dimension n and a response system with dimension m,the proposed approach enab.es each drive system state to b. synchronized with a linear response comb.nation of the response system *** method,b.sed on the Lyapunov stab.lity theory and the pole placement technique,presents some useful features：（i） it enab.es synchronization to b. achieved for b.th cases of n 〈 m and n 〉 m;（ii） it is rigorous,b.ing b.sed on theorems;（iii） it can b. readily applied to any chaotic（hyperchaotic） maps defined to ***,the capab.lity of the approach is illustrated b. synchronization examples b.tween the two-dimensional H′enon map（as the drive system） and the three-dimensional hyperchaotic Wang map（as the response system）,and the three-dimensional H′enon-like map（as the drive system） and the two-dimensional Lorenz discrete-time system（as the response system）.

关键词： chaotic map full state hyb.id projective synchronization inverse prob.em maps with different dimensions

Stab.lity and ergodicity of a stochastic under regime switching on Gilpin-Ayala model patches

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International Journal of b.omathematics 2017年第6期10卷 317-332页

作者： adel Settati Lab.ratory of Mathematics and Applications Department of Mathematics Faculty of Sciences and Techniques B.P. 416-Tanger Principale Tanger Morocco

The purpose of this work is to investigate the asymptotic properties of a stochastic Gilpin--Ayala population system under regime switching on patches. We estab.ish the glob.l stab.lity and the extinction of the trivial equilib.ium state of the model. Further- more, we show the existence of the stationary distrib.tion for our system model. The analytical results are illustrated b. computer simulations.

关键词： Gilpin-Ayala model Markov switching species dispersal extinction ergo-dicity.

An incommensurate fractional discrete macroeconomic system:b.furcation,chaos,and complexity

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Chinese Physics b 2023年第3期32卷 58-67页

作者： Ab.errahmane Ab.es adel Ouannas Nab.l Shawagfeh Department of Mathematics University of JordanAmman 11942Jordan Department of Mathematics and Computer Science University of Larbi Ben M'hidiOum El Bouaghi 04000Algeria

This study proposes a novel fractional discrete-time macroeconomic system with incommensurate *** dynamical b.havior of the proposed macroeconomic model is investigated analytically and *** particular,the zero equilib.ium point stab.lity is investigated to demonstrate that the discrete macroeconomic system exhib.ts chaotic *** using b.furcation diagrams,phase attractors,the maximum Lyapunov exponent and the 0–1 test,we verified that chaos exists in the new model with incommensurate fractional ***,a complexity analysis is carried out utilizing the approximation entropy(ApEn)and C_(0)complexity to prove that chaos ***,the main findings of this study are presented using numerical simulations.

关键词： chaos macroeconomic system discrete fractional calculus complexity

Enhancement in antinociceptive and anti-inflammatory effects of tramadol b. transdermal proniosome gel

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Asian Journal of Pharmaceutical Sciences 2020年第6期15卷 786-796页

作者： Jigar Shah Anroop b.Nair Hiral Shah Shery Jacob.Tamer M.shehata Mohamed Aly Morsy Institute of Pharmacy Nirma UniversityAhmedabad 382481India College of Clinical Pharmacy King Faisal UniversityAl-Ahsa 31982Saudi Arabia Arihant School of Pharmacy&b.I Gandhinagar 382421India College of Pharmacy Gulf Medical UniversityAjman 4184United Arab Emirates Faculty of Pharmacy University of ZagazigZagazig 44519Egypt Faculty of Medicine Minia UniversityEl-Minia 61511Egypt

Oral therapy of tramadol,an opiate analgesic,undergoes extensive hepatic metab.lism and requires frequent *** therapy b. virtue can overcome these issues and can improve the efficacy and reduce ab.se liab.lity of *** aim of this research was to investigate the possib.lity of transdermal delivery of tramadol b. formulating proniosome gel and evaluate its therapeutic potential in *** effect of formulation composition as well as amount of drug on physicochemical characteristics of prepared proniosomes were *** proniosome gel(F4)was selected and evaluated for drug release,stab.lity and transdermal efficacy b. ex vivo and in vivo *** vesicles demonstrated optimal properties including spherical shape,nanosize with good entrapment efficiency,adequate zeta potential,higher stab.lity and greater transdermal *** amorphization and dispersion of tramadol in the aqueous core of proniosome vesicles was confirmed b. differential scanning *** profile of F4 was distinct(Pb. Fickian *** therapy of F4 showed prominent reduction of induced twitches(Pb.erved improvement in antinociceptive and anti-inflammatory effects from proniosome carriers signifies its potential to b. a suitab.e alternative to oral therapy of tramadol with greater efficacy.

关键词： Tramadol Proniosomes Flux Edema Pharmacokinetics Rats

Certification of a Multicomponent Reference Material from Natural Gas Mixture b. Gravimetry and Dual GC-FID/TCD System

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Green and Sustainab.e Chemistry 2023年第4期13卷 269-290页

作者： adel b.ssuoni shehata Ab.ulrahman Rashed AlAskar Najjy Hamad AlYami Ab.ullah Suleiman AlOwaysi Chemistry Department National Measurement and Calibration Center (NMCC) Saudi Standards Metrology and Quality Organization (SASO) Riyadh Kingdom of Saudi Arabia

Natural gas (NG) is one of the most important sources of energy for industrial and domestic consumption in the present era b.cause it is cheap and free from sulfur impurities. Therefore, accurate and precise measurement of its composition is of fundamental importance for trade reasons. To improve the quality of NG gas measurements, certified reference materials (CRMs) should b. used for calib.ation of measuring equipment in order to ensure the traceab.lity of the measurement results to the SI units. For the traceab.lity purpose, a multicomponent natural gas mixture was prepared gravimetrically as a reference material according to ISO 6142 from pure helium, hydrogen, n-pentane, i-pentane, n-b.tane, i-b.tane, propane, ethane, hexane, methane and nitrogen. The preparation was done in two dilution steps in 5 L aluminum cylinders. The calculated mole fractions and associated uncertainties of natural gas components were verified b. a dual GC-FID/TCD system in accordance with ISO 6143 calib.ated b. a series of primary gas mixtures (CRMs) produced b. an NMI. The results ob.ained b. gravimetry and b. GC measurements have b.en checked for compatib.lity as required b. ISO 6142 and were found in very good agreement. Details of the preparation and calculation of the mole fractions and uncertainties of all gas components are explained in this article.

关键词： Pure Gases Gravimetry Reference Material Stab.lity GC Verification Uncertainty