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.

Seismic performance of concrete frames reinforced with superelastic shape memory alloys

Youssef, M.A.,Elfeki, M.A. Techno-Press 2012 Smart Structures and Systems, An International Jou Vol.9 No.4

Reinforced concrete (RC) framed buildings dissipate the seismic energy through yielding of the reinforcing bars. This yielding jeopardizes the serviceability of these buildings as it results in residual lateral deformations. Superelastic Shape Memory Alloys (SMAs) can recover inelastic strains by stress removal. Since SMA is a costly material, this paper defines the required locations of SMA bars in a typical RC frame to optimize its seismic performance in terms of damage scheme and seismic residual deformations. The intensities of five earthquakes causing failure to a typical RC six-storey building are defined and used to evaluate seven SMA design alternatives.

레이저 스캐닝 기법을 이용한 도심지 굴착 계측

Youssef Hashash 東亞大學校 建設技術硏究所 2006 硏究論文集 Vol.30 No.1

도심지 굴착의 안정관리를 위하여 굴착벽체의 횡변 위, 굴착 배면지반 침하, 토압 등 많은 계측이 수행되고 있다. 그러나, 이러한 계측정보들은 굴착면 형상, 시공 상황 등 정확한 시공정보들과 결합되지 못하고 대략적인 시공기록만을 바탕으로 단편적으로 분석되는 실정이다. 정확한 시공 상황을 알지 못하면 계측정보의 분석을 제대로 수행하기 어렵다. 그러므로 정확한 시공 상황을 수집, 기록하여 단편적인 계측정보들과 결합분석하는 안정관리가 필요하다. 본 연구는 도심지 굴착 시 굴착단계별 굴착면 형상, 시공 상황 등을 정밀계측, 기록하기 위하여 레이저 스캐닝이라는 새로운 최신기법을 도입하였다. 이 방법은 레이저 파장을 목표체에 보낸 후 되돌아오는 벚을 감지하여 물체의 거리를 계측한다. 레이저 파장을 여러 위치에서 3차원적으로 계측함으로써 굴착면, 버팀보, 시공기계 등에 대한 3차원 형상정보를 얻을 수 있다. 이 방법을 이용하여 계측하는 방법을 그림 1에 나타내었다. 본 연구에 이용된 레이저 스캐너는 Cyrax 2500으로서 다음의 특징을 가지고 있다. 최대 측정거리는 100 m 이고 ±2 mm의 정밀도를 가지고 있다.

Traumatic cerebrospinal fluid leakage following septorhinoplasty

Youssef, Ahmed,Ahmed, Shahzad,Ibrahim, Ahmed Aly,Daniel, Mulvihill,Abdelfattah, Hisham M.,Morsi, Haitham Korean Society of Plastic and Reconstructive Surge 2018 Archives of Plastic Surgery Vol.45 No.4

Septoplasty/septorhinoplasty is a common ear, nose and throat procedure offered for those patients with deviated septum who are suffering from nasal obstruction and functional or cosmetic problems. Although it is a basic and simple procedure, it could lead to catastrophic complications including major skull base injuries which result in cerebrospinal fluid (CSF) leaks. We describe two different cases of traumatic CSF leaks following septoplasty/septorhinoplasty at two different sites. The first patient suffered a CSF leak following septoplasty and presented to Alexandria University Hospital. The leak was still active at presentation and identified as coming from a defect in the roof of the sphenoid sinus and was repaired surgically. The second patient presented 4 days after her cosmetic septorhinoplasty with a CSF leak and significant pneumocephalus. She was managed conservatively. Understanding the anatomical variations of the paranasal sinuses and implementing proper surgical techniques are crucial in preventing intracranial complications when performing either septoplasty or septorhinoplasty. A good quality computed tomography of the nose and paranasal sinuses is a valuable investigation to avoid major complications especially CSF leaks following either procedure.

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.

Micro-Structure Analysis of Quasi-Static Crushing and Low-Velocity Impact Behavior of Graded Composite Metallic Foam Filled Tube

Youssef Taraz Jamshidi,Ali Pourkamali Anaraki,Mojtaba Sadighi,Javad Kadkhodapour,Seyed Mohammad Hossein Mirbagheri,Behnaz Akhavan 대한금속·재료학회 2021 METALS AND MATERIALS International Vol.27 No.5

Foam filled tubes (FFT) are novel structures with high energy absorption, enhanced strength to weight ratio, and tailoringcapability. In the present paper, we have analyzed quasi-static uniaxial compression and low-velocity impact behavior of FFTwith closed-cell metallic foam cores and functionally graded densities both experimentally and numerically. Alporas foamswere manufactured using liquid state method with TiH2blowing agent. We prepared Specimens with graded compositionand densities by stacking of several layers of pure aluminum and A356 alloy Alporas foams with cubic geometry. We conductedseveral standard uniaxial compression experiments to determine the non-linear mechanical properties and hardening.Square aluminum tubes are manipulated to enhance the performance and tailoring specification of the structure. We generatedmicrostructural models using a hybrid 3D Voronoi diagram and CT-scan images to predict mechanical behavior numerically.Computed tomography is used to determine the inner cells morphological characterization. Also, the modified Kelvin cellwith a beam element in edge regions is manipulated to enhance accuracy. Comparing the quasi-static experiment and FEAresults show good accordance, and hence, we achieved the calibrated model. Finally, we used the numerical model in FFTtailoring and mechanical properties design.

CFD Simulation Tool for Anode-Supported Flat-Tube Solid Oxide Fuel Cell

Youssef M. Elsayed.,Lim, Tak-Hyoung,Song, Rak-Hyun,Lee, Seung-Bok,Shin, Dong-Ryul The Korean Electrochemical Society 2006 한국전기화학회지 Vol.9 No.4

A two-dimensional numerical model to study the performance of anode-supported flat-tube solid oxide fuel cell (SOFC) far the cross section of the cell in the flow direction of the fuel and air flows is developed. In this model a mass and charge balance, Maxwell-Stefan equation as well as the momentum equation by using, Darcy's law are applied in differential form. The finite element method using FEMLAB commercial software is used for meshing, discritization and solving the system of coupled differential equations. The current density distribution and fuel consumption as well as water production are analyzed. Experimental data is used to verify a predicted voltage-current density and power density versus current density to judge on the model accuracy.

Frenectomy for improvement of a problematic conventional maxillary complete denture in an elderly patient: a case report

Youssef S. Al Jabbari 대한치과보철학회 2011 The Journal of Advanced Prosthodontics Vol.3 No.4

Maxillary labial and buccal frena are considered as normal anatomic structures in the oral cavity. However, they may exist intraorally as a thick broad fibrous attachment and/or become located near the crest of the residual ridge, thus interfering with proper denture border extension resulting in inferior denture stability, retention and overall patient satisfaction. This case report highlights the importance of clinical examination and treatment planning which may mandate preprosthetic surgery prior to fabrication of a new conventional complete denture. Adequate patient satisfaction with conventional complete dentures can be significantly increased after frenectomy.

New Action Pattern of a Maltose-forming α-Amylase from Streptomyces sp. and its Possible Application in Bakery

( Youssef Ben Ammar ),( Takayoshi Matsubara ),( Kazuo Ito ),( Masaru Lizuka ) 생화학분자생물학회 2002 BMB Reports Vol.35 No.6

An α-amylase(EC 3.2.1.1) was purified that catalyses the production of a high level of maltose from starch without the attendant production of glucose. The enzyme was produced extracellularly by thermophilic Streptomyces sp. that was isolated from Thailand`s soil. Purification was achieved by alcohol precipitation, DEAE-Cellulose, and Gel filtration chromatographies. The purified enzyme exhibited maximum activity at PH 6-7 and 60℃. It had a relative molecular mass of 45 kDa, as determined by SDS-PAGE. The hydrolysis products from starch had α-anomeric forms, as determined by ^1H-NMR. This-maltose-forming α-amylase completely hydrolyzed the soluble starch to produce a high level of maltose, representing up to 90%. It hydrolyzed maltotetrose and maltotriose to primarily produce maltose (82% and 62%, respectively) without the attendant production of glucose. The high maltose level as a final end-product from starch and maltooligosaccharides, and the unique action pattern of this enzyme, indicate an unusual maltose-forming system. After the addition of the enzyme in the bread-baking process, the bread`s volume increased and kept its softness longer than when the bread had no enzyme.