Low-Voltage CMOS Current Feedback Operational Amplifier and Its Application

Soliman A. Mahmoud,Ahmed H. Madian,Ahmed M. Soliman 한국전자통신연구원 2007 ETRI Journal Vol.29 No.2

A novel low-voltage CMOS current feedback operational amplifier (CFOA) is presented. This realization nearly allows rail-to-rail input/output operations. Also, it provides high driving current capabilities. The CFOA operates at supply voltages of ±0.75 V with a total standby current of 304 μA. The circuit exhibits a bandwidth better than 120 MHz and a current drive capability of ±1 mA. An application of the CFOA to realize a new all-pass filter is given. PSpice simulation results using 0.25 μm CMOS technology parameters for the proposed CFOA and its application are given.

Effect of chronic lead intoxication on the distribution and elimination of amoxicillin in goats

Ahmed M. Soliman,Ehab A. Abu-Basha,Salah A. H. Youssef,Aziza M. Amer,Patricia A. Murphy,Catherine C. Hauck,Ronette Gehring,Walter H. Hsu 대한수의학회 2013 Journal of Veterinary Science Vol.14 No.4

A study of amoxicillin pharmacokinetics was conducted in healthy goats and goats with chronic lead intoxication. The intoxicated goats had increased serum concentrations of liver enzymes (alanine aminotransferase and γ-glutamyl transferase),blood urea nitrogen, and reactivated δ-aminolevulinic acid dehydratase compared to the controls. Following intravenous amoxicillin (10 mg/kg bw) in control and lead-intoxicated goats,elimination half-lives were 4.14 and 1.26 h, respectively. The volumes of distribution based on the terminal phase were 1.19and 0.38 L/kg, respectively, and those at steady-state were 0.54and 0.18 L/kg, respectively. After intramuscular (IM)amoxicillin (10 mg/kg bw) in lead-intoxicated goats and control animals, the absorption, distribution, and elimination of the drug were more rapid in lead-intoxicated goats than the controls. Peak serum concentrations of 21.89 and 12.19 μg/mL were achieved at 1 h and 2 h, respectively, in lead-intoxicated and control goats. Amoxicillin bioavailability in the lead-intoxicated goats decreased 20% compared to the controls. After amoxicillin, more of the drug was excreted in the urine from lead-intoxicated goats than the controls. Our results suggested that lead intoxication in goats increases the rate of amoxicillin absorption after IM administration and distribution and elimination. Thus, lead intoxication may impair the therapeutic effectiveness of amoxicillin.

Impact of hydrophobic tails of new phospho-zwitterionic surfactants on the structure, catalytic, and biological activities of AgNPs

Ahmed H. Elged,Samy M. Shaban,M.M. Eluskkary,I. Aiad,E.A. Soliman,Asma M. Elsharif,김동환 한국공업화학회 2021 Journal of Industrial and Engineering Chemistry Vol.94 No.-

In this study, three anionic-cationic zwitterionic Gemini surfactants containing three differenthydrophobic tails were prepared and their chemical structures were confirmed by Fourier transforminfrared (FTIR) and 1H nuclear magnetic resonance (NMR) spectroscopy. The hydrophobic tail of thesynthesized phospho-zwitterionic Gemini surfactants significantly affected the morphological structureof silver nanoparticles (AgNPs) prepared using a photochemical reduction method, which utilizedsunlight as a surplus source of a reducing agent. Increasing the hydrophobic tail length of the surfactantpromoted the formation of AgNPs exhibiting smaller particle sizes with a uniform structure. Moreover, asconfirmed by ultraviolet-visible (UV-Vis) spectroscopy, dynamic light scattering (DLS), and transmissionelectron microscopy (TEM), these AgNPs displayed higher stability in solution than those synthesized inthe presence of Gemini surfactants with a shorter hydrocarbon tail. The impact of tail variation on thecatalytic and antimicrobial performance of AgNPs was also examined. The synthesized surfactant/AgNPsystems showed remarkable catalytic activity in the removal of certain toxic pollutants, including paranitrophenol(p-NP) and methylene blue (MB), which were converted into less toxic compounds in thepresence of NaBH4. Notably, the surfactant exhibiting the longest chain hydrocarbon, i.e., ZGH, producedAgNPs with the highest catalytic activity. This is thefirst study concerning the effects of the surfactant tailon the catalytic activity of NPs. The good biological performance of the synthesized Gemini surfactantsagainst sulfate-reducing bacteria (SRB) demonstrated their potential for application in mitigating thegrowth of SRB during petroleum treatment processes. The combination of the synthesized surfactantswith AgNPs significantly enhanced their biological performance.

Contribution of avoidance and tolerance strategies towards salinity stress resistance in eight C3 turfgrass species

Wagdi Saber Soliman,Shu-ichi Sugiyama,Ahmed M. Abbas 한국원예학회 2018 Horticulture, Environment, and Biotechnology Vol.59 No.1

Salinity is a potential environmental stress factor for plants. Improving plant growth under salinity stress requires an understandingof resistance mechanisms. Salinity stress resistance is related to both salinity avoidance and tolerance. In this study,interspecific differences in salinity stress resistance, avoidance, and tolerance were examined in eight C3turfgrass species,namely Agrostis alba, Agrostis tenius, Dactylis glomerata, Festuca ovina, Festuca rubra, Lolium perenne, Phleum pratense,and Poa pratensis. In a greenhouse experiment, plants were exposed to 50, 100, or 200 mM NaCl for 2 weeks supplied via ahydroponics system. We found that interspecific differences in salinity stress resistance were associated mainly with salinitytolerance. Salinity avoidance mechanisms also contributed significantly to stress resistance. The contribution of genotypetowards interspecific variation in salinity resistance and tolerance was higher than that of Na+concentration. Salinity stresshad negative effects on shoot dry mass, water status, and membrane stability. Relative water content was significantly correlatedwith salinity resistance, avoidance, and tolerance, whereas no significant correlation was observed for ion leakage. Mineral contents showed no clear contribution to salinity tolerance. Species varied in their proline content even in controlconditions, and there was a positive association between proline content and salinity resistance and tolerance, but a negativeassociation between proline content and salinity avoidance. F. ovina and P. pratense displayed the highest and lowest salinitystress resistance, respectively. The results of this study suggest that both salinity tolerance and avoidance mechanismscontribute towards salinity resistance, and that variation in salinity stress resistance among species is attributed to differencesin proline content.

Optimization, Purification, and Characterization of Haloalkaline Serine Protease from a Haloalkaliphilic Archaeon Natrialba hulunbeirensis Strain WNHS14

( Rania S Ahmed ),( Amira M Embaby ),( Mostafa Hassan ),( Nadia A Soliman ),( Yasser R Abdel-fattah ) 한국미생물생명공학회(구 한국산업미생물학회) 2021 한국미생물·생명공학회지 Vol.49 No.2

The present study addresses isolation, optimization, partial purification, and characterization of a haloalkaline serine protease from a newly isolated haloarchaeal strain isolated from Wadi El Natrun in Egypt. We expected that a two-step sequential statistical approach (one variable at a time, followed by response surface methodology) might maximize the production of the haloalkaline serine protease. The enzyme was partially purified using Hiprep 16/60 sephacryl S-100 HR gel filtration column. Molecular identification revealed the newly isolated haloarchaeon to be Natrialba hulunbeirensis strain WNHS14. Among several tested physicochemical determinants, casamino acids, KCl, and NaCl showed the most significant effects on enzyme production as determined from results of the One-Variable-At-A-time (OVAT) study. The Box- Behnken design localized the optimal levels of the three key determinants; casamino acids, KCl, and NaCl to be 0.5% (w/v), 0.02% (w/v), and 15% (w/v), respectively, obtaining 62.9 U/ml as the maximal amount of protease produced after treatment at 40℃, and pH 9 for 9 days with 6-fold enhancement in yield. The enzyme was partially purified after size exclusion chromatography with specific activity, purification fold, and yield of 1282.63 U/mg, 8.9, and 23%, respectively. The enzyme showed its maximal activity at pH, temperature, and NaCl concentration optima of 10, 75℃, and 2 M, respectively. Phenylmethylsulfonyl fluoride (PMSF, 5 mM) completely inhibited enzyme activity.

Synthesis and Characterization of New Transition Metal Complexes of Schiff-base Derived from 2-Aminopyrimidine and 2,4-Dihydroxybenzaldehyde and Its Applications in Corrosion Inhibition

Ouf, Abd El-Fatah M.,Ali, Mayada S.,Soliman, Mamdouh S.,El-Defrawy, Ahmed M.,Mostafa, Sahar I. Korean Chemical Society 2010 대한화학회지 Vol.54 No.4

New complexes cis-[$Mo_2O_5(Hapdhba)_2$], trans-[$UO_2(Hapdhba)_2$], [Pd(Hapdhba)Cl($H_2O$)], [Pd(bpy)(Hapdhba)]Cl, [Ag(bpy)(Hapdhba)], [$Ru(Hapdhba)_2(H_2O)_2$], [$Rh(Hapdhba)_2Cl(H_2O)$] and [Au(Hapdhba)$Cl_2$] are reported, where $H_2$apdhba is the Schiff-base derived from 2-aminopyrimidine and 2,4-dihydroxy benzaldehyde. The complexes were characterized by IR, electronic, $^1H$ NMR and mass spectra, conductivity, magnetic and thermal measurements. The inhibitive effect of $H_2$apdhba for the corrosion of copper in 0.5 M HCl was also determined by potentiodynamic polarization measurements. 새로운 착물인 cis-[$Mo_2O_3(Hapdhba)_2$], trans-[$UO_2(Hapdhba)_2$], [Pd(Hapdhba)Cl($H_2O$)], [Pd(bpy)(Hapdhba)]Cl, [Ag(bpy) (Hapdhba)], [$Ru(Hapdhba)_2(H_2O)_2$], [$Rh(Hapdhba)_2Cl(H_2O)$] 및 [Au(Hapdhba)$Cl_2$]를 보고한다. 여기서 $H_2$apdhba는 2-aminopyrimidine 및 2,4-dihydoxybenzaldehyde에서 비롯된 Schiff-염기이다. 이들 착물은 IR, UV-Vis 그리고 질량 스펙트럼을 비롯하여 전기전도도, 자기 및 열 분석을 통해 특성을 조사하였다. 구리의 부식에 대한 $H_2$apdhba의 방해효과는 0.5 M HCl에서 potiodynamic polarization 측정을 통해 조사하였다.

New CMOS Fully Differential Transconductor and Application to a Fully Differential Gm-C Filter

Mohamed Omran Shaker,Soliman A Mahmoud,Ahmed M Soliman 한국전자통신연구원 2006 ETRI Journal Vol.28 No.2

A new CMOS voltage-controlled fully-differential transconductor is presented. The basic structure of the proposed transconductor is based on a four-MOS transistor cell operating in the triode or saturation region. It achieves a high linearity range of ± 1 V at a 1.5 V supply voltage. The proposed transconductor is used to realize a new fully-differential Gm-C low-pass filter with a minimum number of transconductors and grounded capacitors. PSpice simulation results for the transconductor circuit and its filter application indicating the linearity range and verifying the analytical results using 0.35 μm technology are also given.

A novel technique for the removal of strontium from water using thermophilic bacteria in a membrane reactor

Omar Chaalal,Abdulrazag Y. Zekri,Ahmed M. Soliman 한국공업화학회 2015 Journal of Industrial and Engineering Chemistry Vol.21 No.1

Contamination in drinking water is the most common form of environmental problems encountered inwater resources management. Some contaminants, present accidentally in drinking water, are verydifficult to remove, such as heavy elements that are products of industrial waste. Strontium is one of themost difficult-to-remove elements. This paper proposes a novel process for removal of strontiumcompounds contaminants from water. The proposed method shows great efficiency. The technique usesthermophilic bacteria found in the United Arab Emirates near Al-Ain town located in Abu-DhabiEmirates. These bacteria were isolated and used in a reactor coupled with a membrane system. Thebacteria, the stirrer and the membrane housed in the reactor are arranged in a distinctive way to form thenovel bio-stabilization process proposed in this research. This proposed technique could be used at lowcost and with great confidence in the purification of drinking water. The system was found to beadequate for concentrations of strontium in the range of 5–30 ppm. At the end of the operation thestrontium concentration reaches the level allowed by the World Health Organization regulations.

Fuzzy inference systems based prediction of engineering properties of two-stage concrete

Manal F. Najjar,Moncef L. Nehdi,Tareq M. Azabi,Ahmed M. Soliman 사단법인 한국계산역학회 2017 Computers and Concrete, An International Journal Vol.19 No.2

Two-stage concrete (TSC), also known as pre-placed aggregate concrete, is characterized by its unique placement technique, whereby the coarse aggregate is first placed in the formwork, then injected with a special grout. Despite its superior sustainability and technical features, TSC has remained a basic concrete technology without much use of modern chemical admixtures, new binders, fiber reinforcement or other emerging additions. In the present study, an experimental database for TSC was built. Different types of cementitious binders (single, binary, and ternary) comprising ordinary portland cement, fly ash, silica fume, and metakaolin were used to produce the various TSC mixtures. Different dosages of steel fibres having different lengths were also incorporated to enhance the mechanical properties of TSC. The database thus created was used to develop fuzzy logic models as predictive tools for the grout flowability and mechanical properties of TSC mixtures. The performance of the developed models was evaluated using statistical parameters and error analyses. The results indicate that the fuzzy logic models thus developed can be powerful tools for predicting the TSC grout flowability and mechanical properties and a useful aid for the design of TSC mixtures.

E1/E2 of Hepatitis C Virus Genotype-4 and Apoptosis

Zekri, Abdel-Rahman N,Sobhy, Esraa,Hussein, Nehal,Ahmed, Ola S,Hussein, Amira,Shoman, Sahar,Soliman, Amira H,El-Din, Hanaa M Alam Asian Pacific Journal of Cancer Prevention 2016 Asian Pacific journal of cancer prevention Vol.17 No.7

Several studies have addressed the possible role of hepatitis C virus genotype-4 (HCV GT4) in apoptosis. However, this still not fully understood. In the current study a re-constructed clone of E1/E2 polyprotein region of the HCV GT4 was transfected into the Huh7 cell line and a human apoptotic PCR array of 84 genes was used to investigate its possible significance for apoptosis. Out of the 84 genes, only 35 showed significant differential expression, 12 genes being up-regulated and 23 down-regulated. The highest-up regulated genes were APAF1 (apoptotic peptidase-activating factor 1), BID (BH3 interacting domain death agonist) and BCL 10 (B-cell CLL/lymphoma protein 10) with fold regulation of 33.2, 30.1 and 18.9, respectively. The most down-regulated were FAS (TNF receptor super family), TNFRSF10B (tumor necrosis factor receptor super-family member 10b) and FADD (FAS-associated death domain) with fold regulation of -30.2, -27.7 and -14.9, respectively. These results suggest that the E1/E2 proteins may be involved in HCV-induced pathogenesis by modulating apoptosis through the induction of the intrinsic apoptosis pathway and disruption of the BCL2 gene family.