http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
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.
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.
( 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.
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.
Water Vapor Adsorption and Hydrogen Peroxide Decomposition on Date Pit Carbonization Products
Youssef, A.M.,El-Nabarawy, Th.,Ahmed, S.A. Sayed,Rashwan, W.E. Korean Carbon Society 2005 Carbon Letters Vol.6 No.4
Carbonization products C1, C2, C3, C4 and C5 were prepared by the carbonization of date pit in limited air, at 500, 600, 700, 800 and $1000^{\circ}C$, respectively. C1-V-600, C3-V-600, C1-V-1000 and C3-V-1000 were prepared by thermal treatment of C1 and C3 under vacuum at 600 and $1000^{\circ}C$. The textural properties were determined from nitrogen adsorption at 77 K and from carbon dioxide adsorption at 298 K. The surface pH, the FTIR spectra and the acid and base neutralization capacities of some carbons were investigated. The amounts of surface oxygen were determined by out-gassing the carbon-oxygen groups on the surface as $CO_2$ and CO. The adsorption of water vapor at 308 K on C1, C2, C3 and C4 was measured and the decomposition of $H_2O_2$ at 308 K was also investigated on C1, C2, C3, C4 and C5. The surface area and the total pore volume decreased with the rise of the carbonization temperature from 500 to $1000^{\circ}C$. The adsorption of water vapor is independent on the textural properties, while it is related to the amount of acidic carbon-oxygen groups on the surface. The catalytic activity of $H_2O_2$ decomposition does not depend on the textural properties, but directly related to the amount of basic carbon-oxygen complexes out-gassed as CO, at high temperatures.
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.
Positive Periodic Solutions of Systems of Functional Differential Equations
Youssef N. Raffoul 대한수학회 2005 대한수학회지 Vol.42 No.4
We apply a cone theoretic fixed point theorem and obtainconditions for the existence of positive periodic solutions of thesystem of functional differential equations $$ x'(t) = A(t)x(t) + \lambda f(t, x(t-\tau(t))
A variant of Wilson's functional equation on semigroups
Youssef Aserrar,Abdellatif Chahbi,Elhoucien Elqorachi 대한수학회 2023 대한수학회논문집 Vol.38 No.4
Let $S$ be a semigroup. We determine the complex-valued solutions of the following functional equation \[f(xy)+\mu (y)f(\sigma (y)x) = 2f(x)g(y),\ x,y\in S,\] where $\sigma:S\rightarrow S$ is an automorphism, and $\mu :S\rightarrow \mathbb{C}$ is a multiplicative function such that $\mu (x\sigma (x))=1$ for all $x\in S$.
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.