http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Influence of Skull Anisotropic Mechanical Properties in Low-Intensity Focused Ultrasound
Metwally, M. K.,Han, H.-S.,Jeon, H. J.,Nam, S. B.,Han, S. M.,Kim, T.-S. WORLD SCIENTIFIC PUBLISHING 2016 Vol.24 No.1
<P>Low-intensity focused ultrasound (LIFU) is a new noninvasive brain stimulation technique where ultrasound is applied with low frequency and intensity to focus at a target region within the brain in order to exhibit or inhibit neuronal activity. In applying LIFU to the human brain, the skull is the main barrier due to its well-known high anisotropic mechanical properties which will affect the ultrasound focusing thereby affecting the neuromodulation or brain stimulation. This study aims at investigating the influence of the anisotropic mechanical properties of the skull on ultrasound propagation and focusing in LIFU. In this study, we used 2D finite element (FE) head models incorporating the isotropic and anisotropic properties of the skull. Three kinds of stresses were examined and shown within the skull: namely the normal stress in the direction of wave propagation (x-stress), normal stress in the transverse direction to the wave propagation (y-stress), and shear stress. Our analysis show that although most of the pressure that reaches to the brain is due to the longitudinal wave propagation through the skull, the stress in the transverse direction to the wave propagation direction (y-stress) has the main influence on the pressure profile inside the brain. The results also show that the anisotropic properties of the skull broaden the focal size about 19% and 13% in the longitudinal and transverse directions, respectively more than the case of considering the isotropic properties in the realistic 2D FE head model. The results indicate the importance of considering the anisotropic properties of the skull in practicing LIFU to achieve accurate targeting within the brain.</P>
Kraidees, M.S.,Al-Haidary, I.A.,Mufarrej, S.I.,Al-Saiady, M.Y.,Metwally, H.M.,Hussein, M.F. Asian Australasian Association of Animal Productio 2009 Animal Bioscience Vol.22 No.8
A trial was conducted to study the effect of supplemental chromium (Cr) levels from a Cr-yeast source on performance, digestibility and carcass characteristics of transport-stressed lambs. Forty-eight Naemi lambs (avg. BW 31.7 kg) were transported by truck for a distance of 1,450 km. On arrival day, the lambs were randomly allocated to four groups receiving diets supplemented with 0.0, 0.3, 0.6 or 0.9 ppm Cr. Each group consisted of four separately housed replicates of three lambs each. The lambs were fed their respective diets ad libitum for 84 d (21 d stress period, followed by 63 d growing period). Road transit of lambs resulted in a decreased (p<0.001) live body weight of 8.5%. Supplementation of Cr-yeast did not alter the performance of lambs during the stress period. Linear and quadratic increases (p<0.05) were observed in DMI and ADG, respectively, with increasing supplemental Cr levels in the diets during the growing period. Values were greater (p<0.05) by 14.7% and 20.8%, respectively, for lambs fed 0.3 ppm Cr compared to control, while those fed on the other two levels were intermediate. Over the 84-d feeding period, a trend was noted towards a slight increase in loin eye area and a decrease in body wall fat thickness for lambs fed Cr supplementation compared to the control group. This study suggests that the supplementation of Cr-yeast, especially at 0.3 ppm level, is beneficial for improving the performance of growing lambs whether the animals are stressed or not.
M.A. bedair,S.A. Soliman,M.S. Metwally 한국공업화학회 2016 Journal of Industrial and Engineering Chemistry Vol.41 No.-
Synthesis, adsorption and corrosion inhibiting effect of three surfactants consist of Schiff bases ashydrophobic part and poly ethylene glylcol (poly ethylene oxide) as hydrophilic part on steel in 1.0 MHCl was investigated using weight loss, Electrochemical Impedance, potentiodynamic polarizationtechniques and computational methods. The experimental findings revealed that these compoundsinhibited the corrosion reaction in 1.0 M HCl environment. Polarization curves revealed that the usedinhibitors represent mixed-type inhibitors. There was a good correlation between the experimentalresults and quantum chemical parameters of the surfactants. Molecular dynamic simulation indicatedthat these surfactants were adsorbed on the metal surface
M.K. Awad,M.S. Metwally,S.A. Soliman,A.A. El-Zomrawy,M.A. bedair 한국공업화학회 2014 Journal of Industrial and Engineering Chemistry Vol.20 No.3
The corrosion inhibition of poly ethylene glycol (PEG) toward the aluminum surface in 1.0 M HCl hasbeen studied by weight loss and polarization techniques. The results showed that the PEG acts as a goodinhibitor and the inhibition efficiency is due to the anodic and cathodic inhibition (mixed type). Thethermodynamic functions were calculated to find a good correlation with the inhibition efficiency. Quantum chemical parameters were calculated using ab initio and DFT methods to find a goodcorrelation with the inhibition efficiency. A good correlation was found between the theoreticalcalculations and experimental observations.
S.A. Soliman,M.S. Metwally,S.R. Selim,M.A. bedair,Mohamed A. Abbas 한국공업화학회 2014 Journal of Industrial and Engineering Chemistry Vol.20 No.6
Synthesis, adsorption and corrosion inhibiting effect of new Schiff base surfactant named 4-hydroxy-3-(3-phenyl-allylideneamino)-benzene sulphonic acid2-[2-(2-{2-[2-(2-hydroxy-ethoxy)-ethoxy]-ethoxy}-ethoxy)-ethoxy]-ethyl ether (abbreviated as PAAB) on mild steel in 1.0 M HCl were investigatedusing weight loss, and potentiodynamic polarization techniques. The results revealed that thiscompound inhibited the corrosion reaction in HCl environment. The results indicated that this inhibitorwas adsorbed on the metal/solution interface. Theoretical study of the adsorption behavior of thiscompound was carried out in the framework of the semiempirical (SE) and molecular dynamics (MD).
Metwally, M.A.,Bondock, S.A.,El-Desouky, S.I.,Abdou, M.M. Korean Chemical Society 2012 대한화학회지 Vol.56 No.1
Novel azopyrazolin-5-one dyes 4a-f were synthesized by the regioselective reaction of phenylhydrazine with 2,3,4-chromantrione-3-arylhydrazones 2a-f. The acid dissociation constants $pK_a$ for the series prepared were determined and correlated by the Hammett equation. The results of such correlation together with the spectral data indicated that the studied compounds exist predominantly in the hydrazone keto structure, (D) as the Z-configuration. The dyes were applied to polyester fabrics, affording orange-yellow shades and assessments of their dyeing performance are considered. Further, the compounds 4a-f were screened for their antimicrobial activity against various microorganisms.
Metwally, M.A.,Bondock, S.,El-Desouky, S.I.,Abdou, M.M. Korean Chemical Society 2012 대한화학회지 Vol.56 No.3
In an attempt to find a new class of bisazo disperse dyes with better dyeing properties, a series of novel bisazo dyestuffs based on 4-arylhydrazono-3-(2'-hydroxyphenyl)-1-phenyl-2-pyrazolin-5-ones $\mathbf{3a-f}$ were prepared by diazocoupling of p-nitrophenyl diazonium chloride with 4-arylhydrazono-3-(2'-hydroxyphenyl)-1-phenyl-2-pyrazolin-5-ones $\mathbf{2a-f}$. Compounds $\mathbf{3a-f}$ were subsequently reacted with acetic anhydride in the presence of p-toluenesulfonic acid afford the corresponding O-acetyl derivatives $\mathbf{4a-f}$. The latter products as well as spectral data indicated that compounds $\mathbf{3a-f}$ exist predominantly in the azo-hydrazone tautomeric form (H) as the ZE-configuration. Additionally, two series of the synthesized dyes $\mathbf{3a-f}$ and $\mathbf{4a-f}$ were applied as disperse dyes for dyeing polyester fabrics and their fastness properties were evaluated. Also the position of color in CIELAB coordinates ($L^*$, $a^*$, $b^*$, $H^*$, $C^*$*) was assessed.
M.M. El-Nahass,H.S. Metwally,H.E.A. El-Sayed,A.M. Hassanien 한국물리학회 2014 Current Applied Physics Vol.14 No.2
The JeV characteristics of the Au/5,10,15, 20-tetraphenyl-21H, 23H-porphine iron (III) chloride (FeTPPCl)/ ITO device exhibits rectifying behavior in the dark which can be explained due to the formation of Schottky barrier at ITO/FeTPPCl junction and the typical junction parameters were estimated in temperatures from 302 to 368 K. The temperature dependence of DC electrical conductivity showed that FeTPPCl films behave as semiconducting materials. These results indicate that the DC electrical conduction is through an activated process having three conduction mechanisms in the investigated range of temperatures. A variable range hopping model, a polaron model and band to band transitions have been used to explain the conduction mechanisms for FeTPPCl films.
Walash, M.I.,El-Brashy, A.M.,Metwally, M.S.,Abdelal, A.A. Korean Chemical Society 2004 Bulletin of the Korean Chemical Society Vol.25 No.4
Two simple and sensitive spectrophotometric methods were developed for the determination of carbocisteine, penicillamine, ethionamide and thioctic acid in bulk and in their pharmaceutical preparations using alkaline potassium permanganate as an oxidizing agent. The first one involves determination of ethionamide and thioctic acid by spectrophotometric investigation of the oxidation reaction of the two drugs. The second method involves determination of carbocisteine and penicillamine by kinetic studies of the oxidation reaction of these two drugs at room temperature for a fixed time of 20 minutes. The absorbance of the colored manganate ions was measured at 610 nm in both methods. 1-10 ${\mu}$g/mL of ethionamide and thioctic acid could be etermined by the spectrophotometric method with detection limits of 0.11 and 0.089 ${\mu}$g/mL for the two drugs respectively. 2-10 ${\mu}$g/mL of carbocisteine and penicillamine could be determined by the kinetic method with detection limits of 0.14 and 0.21 ${\mu}$g/mL respectively. The two methods were successfully applied for the determination of these drugs in their dosage forms.