3-아미노-1H-피라졸-4-카르복실산 에틸의 디아조화와 결합반응;피라졸로아진의 합성

Youssef, Ayman M.S.,Faty, Rasha A.M.,Youssef, Mohamed M. 대한화학회 2001 대한화학회지 Vol.45 No.5

피라졸로아진은 농업이나 의약품에서 매우 유용한 화합물등이다. 본 논문에서는 몇 가지 새로운 피라졸로아진의 합성을 보고하고자 한다. 표제 화합물인 3-아미노-1H-피라졸-4-카복실산 에틸을 다이아조화한 후 활성화된 메틸렌 화합물들과 반응시키고 고리화하여 피라졸로[5,1-c][1,2,4]트라이아진 유도체들을 합성하였다. 또한 표제 화합물을 $\alpha$-치환된 신남나이트릴과 반응시켜 피라졸로[1,5-a]피리미딘 유도체들을 합성하였다. 새로 합성된 화합물들의 구조는 화학적 방법과 분광학적 방법을 사용하여 확립하였다. Pyrazoloazines are extremely useful in agriculture and medicine. The main objective of this article is to synthesize some new pyrazoloazines. Ethyl 3-amino-1H-pyrazole-4-carboxylate undergoes diazotization, couples with activated methylene compounds and cyclizes to form pyrazolo[5,1-c][1,2,4]tri-azine derivatives. The title compound also reacts with $\alpha$-substituted cinnamonitriles to produce pyrazolo[1,5-a]pyrimidine derivatives. Structures of newly synthesized compounds are established via chemical and spectral methods.

Isolated Sudden Bilateral Neurosensory Hearing Loss as a Presentation of Lyme Neuroborreliosis: A Case Study

Rochd Sara,Benhoummad Othmane,Salhi Salma,Lakhdar Youssef,Rochdi Youssef,Raji Abdelaziz,Oualhadj Hamza,Kamouni Youssef El,Zouhair Said 대한청각학회 2024 Journal of Audiology & Otology Vol.28 No.1

Lyme neuroborreliosis (LNB) is a rare but potentially serious manifestation of Lyme disease, caused by the spirochete <i>Borrelia burgdorferi</i>. Although LNB can affect various neurological systems, neurosensory hearing loss as the sole presentation is uncommon. We report a case of a 23-year-old woman who presented with a 2-month history of temporal headache, tinnitus, and instability, which was followed by sudden bilateral hearing loss without any other associated symptoms. Pure-tone audiometry revealed profound bilateral hearing loss. Serological testing for various pathogens was negative, except for <i>B. burgdorferi</i> IgM, which was confirmed using Western blot analysis. The patient received doxycycline treatment; unfortunately, no recovery of hearing was observed. This case report highlights the importance of considering LNB as a potential cause of neurosensory hearing loss, particularly in areas where Lyme disease is endemic, as well as the need for timely diagnosis and treatment to prevent potential complications.

Removal of Pb(II) and Cd(II) From Aqueous solution Using Oxidized Activated Carbons Developed From Pecan Shells.

Youssef, A.M.,EL-Khouly, Sahar M.,El-Nabarawy, Th. Korean Carbon Society 2008 Carbon Letters Vol.9 No.1

Oxidized activated carbons were prepared by reacting steam-activated carbon developed from pecan shells with nitric acid of varying strength (15, 30, 45 and 60%). The textural properties and the chemistry of the surface of the non-oxidized and of the oxidized carbons were determined from nitrogen adsorption and base neutralization capacities. The uptake of Pb(II) and Cd(II) from aqueous solution by these carbons was determined by kinetic and equilibrium experiments as well as by the column method. Treatment with nitric acid brought about drastic decrease in surface area and remarkable increase in the pore size of the carbon with these changes depending on the strength of nitric acid. Nitric acid increased the surface acidity by developing new surface oxygen functional groups of acidic nature. $HNO_3$-oxidized carbons exhibited high adsorption capacities for Pb(II) and Cd(II). The adsorption of these ions increased with the decrease of the surface pH of the carbon and with the increase of the solution pH from 2.5 to 6 and 7. The amount adsorbed from lead and cadmium was also related to the amount of surface acidity, the pH of the point of zero charge and on some metal ion parameters. Cadmium and lead uptake by the investigated carbons followed pseudo-second order model and the equilibrium sorption data fitted Langmuir adsorption model.

On the Nonlinear Impact of Oil Price Shocks on the World Food Prices Under Different Markets Conditions

Youssef Manel,Mokni Khaled 한국국제경제학회 2021 International Economic Journal Vol.35 No.1

This paper investigates the impact of oil price shocks on the world food prices. We use the structural VAR model to disentangle oil price shocks into supply, aggregate demand, and oil-specific demanddriven shocks. Moreover, we employ a new approach based on the Markov regime-switching quantile regression (MRS-QR) model to investigate the response of food prices to different oil price shocks. Based on monthly data from 1992 to 2018, results show that the reaction of food prices to different structural oil shocks depends on the oil price regimes and varies in significance, sign, and size throughout the food market conditions. Besides, the increases in regression coefficients and smoothed probability during food and oil crisis periods confirm the existence of contagion effects between oil and food markets. Moreover, we find that the supply and aggregate demand shocks do not show a strong contribution to the presence of this phenomenon. Conversely, oil-specific demand shocks represent the main factor that contributes to contagion between oil and food markets.

Multimodal Biometric Using a Hierarchical Fusion of a Person`s Face, Voice, and Online Signature

( Youssef Elmir ),( Zakaria Elberrichi ),( Reda Adjoudj ) 한국정보처리학회 2014 Journal of information processing systems Vol.10 No.4

Biometric performance improvement is a challenging task. In this paper, a hierarchical strategy fusion based on multimodal biometric system is presented. This strategy relies on a combination of several biometric traits using a multi-level biometric fusion hierarchy. The multi-level biometric fusion includes a pre-classification fusion with optimal feature selection and a post-classification fusion that is based on the similarity of the maximum of matching scores. The proposed solution enhances biometric recognition performances based on suitable feature selection and reduction, such as principal component analysis (PCA) and linear discriminant analysis (LDA), as much as not all of the feature vectors components support the performance improvement degree.

Modified Activated Carbons from Olive Stones for the Removal of Heavy Metals

Youssef, A.M.,El-Nabarawy, Th.,El-Shafey, E.I. Korean Carbon Society 2006 Carbon Letters Vol.7 No.1

The activated carbon "C" was obtained by carbonization followed by activation with steam at 40% of burn-off. Oxidized carbons C-N, C-P and C-H were obtained by oxidizing the activated carbon C with concentrated nitric acid, ammonium peroxysulfate and hydrogen peroxide, respectively. The textural properties of the carbons were determined from nitrogen adsorption at 77 K. The acidic surface functional groups were determined by pH titration, base neutralization capacity and electrophoretic mobility measurements. The cation exchange capacities of un-oxidized and oxidized carbons were determined by the removal of Cu(II) and Ni(II) from their aqueous solutions. The surface area and the total pore volume decreased but the pore radius increased by the treatment of activated carbon with oxidizing agents. These changes were more pronounced in case of oxidation with $HNO_3$. The surface pH of un-oxidized carbon was basic whereas those of the oxidized derivative were acidic. The removal of Cu(II) and Ni(II) was pH dependent and the maximum removal of the both ions was obtained at pH of 5-6. Cu(II) was more adsorbed, a phenomenon which was ascribed to its particular electronic configuration.

The Effect of Three Different Surface Treatments on the Retention of Composite Core Material on Prefabricated Post-heads

Youssef S. Al Jabbari 대한치과재료학회 2011 대한치과기재학회 학술대회 Vol.2011 No.5

Soil Water Content Estimation Using Visible and Near Infrared Spectroscopy

Youssef Fouad,Didier Michot,Zahra Thomas,Raphael Viscarra Rossel 한국토양비료학회 2014 한국토양비료학회 학술발표회 초록집 Vol.2014 No.6

Hazard identification and scenario selection of ship grounding accidents

Youssef, Samy Adly Mansour,Paik, Jeom Kee Elsevier 2018 Ocean engineering Vol.153 No.-

<P><B>Abstract</B></P> <P>The objectives of the present paper are to identify the hazard of ship grounding; where a ship runs on a rock with a forward speed, and to select a set of credible scenarios with a limited number that can still represent all possible situations of the accidents. For this purpose, the statistics of ship grounding accidents recorded by authorities for the period of 46 years during 1970–2016 are collated. An extensive analysis is undertaken to examine the statistical characteristics in association with random variables influencing the consequence of grounding. A total of six parameters, namely ship's forward speed, ship's trim angle, rock tip eccentricity, rock length, rock width and rock height are considered as random variables where the displacement or mass of the grounded ship is fixed. Each of the random variables is then formulated with a probability density function. A sampling technique is applied to the probabilistic selection of the grounding scenarios which are to be used for the consequence analysis within the framework of quantitative risk assessment. Important insights developed from the present study are discussed. Details of the analyses are documented.</P> <P><B>Highlights</B></P> <P> <UL> <LI> This article aims to identify the hazard of ship grounding to select a set of scenarios represent all possible situations. </LI> <LI> Statistics of ship grounding accidents recorded by authorities are collated. </LI> <LI> Extensive analyses are performed to examine the statistical characteristics with random variables of grounding. </LI> <LI> A sampling technique is applied to the probabilistic selection of the grounding scenarios. </LI> <LI> Selected credible scenarios are essential within the framework of quantitative grounding risk assessment and management. </LI> </UL> </P>

Gastric Duplication Cyst Presenting as Massive Gastrointestinal Bleeding

Youssef, Alexey,Ibrahim, Alexander,AlShehabi, Zuheir,Omran, Ammar,Sharara, Ala I. The Korean Society of Pediatric Gastroenterology 2019 Pediatric gastroenterology, hepatology & nutrition Vol.22 No.2

Gastric duplication cysts (GDCs) are rare congenital anomalies. Presentation of GDCs varies from an asymptomatic abdominal mass to fulminant or massive gastrointestinal (GI) bleeding. Herein, we describe a case of a GDC in a 10-month-old infant presenting with unexplained massive GI hemorrhage and hematemesis. An abdominal ultrasound was negative, while computerized tomography was, initially, inaccessible. Through a series of repeated esophagogastroduodenoscopies, we documented penetration of the GDC into the gastric cavity that was later confirmed by computerized tomography. The patient was treated successfully with surgical resection.