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.

Fabrication and performance evaluation of ultraviolet photodetector based on organic /inorganic heterojunction

H. Abdel-Khalek,M.I. El-Samahi,Mohamed Abd- El Salam,Ahmed M. El-Mahalawy 한국물리학회 2018 Current Applied Physics Vol.18 No.12

Organic/inorganic ultraviolet photodetector was fabricated using thermal evaporation technique. Organic/inorganic heterojunction based on thermally evaporated copper (II) acetylacetonate thin film of thickness 200 nm deposited on an n-type silicon substrate is introduced. I–V characteristics of the fabricated heterojunction were investigated under UV illumination of intensity 65 mW/cm2. The diode parameters such as ideality factor, n, barrier height, ΦB, and reverse saturation current, Is, were determined using thermionic emission theory. The series resistance of the fabricated diode was determined using modified Nord's method. The estimated values of series resistance and barrier height of the diode were about 0.33 KΩ and 0.72 eV, respectively. The fabricated photodetector exhibited a responsivity and specific detectivity about 9 mA/W and 4.6×109 Jones, respectively. The response behavior of the fabricated photodetector was analyzed through ON-OFF switching behavior. The estimated values of rise and fall time of the present architecture under UV illumination were about 199 ms and 154 ms, respectively. Finally, enhancing the photoresponsivity of the fabricated photodetector, post-deposition plasma treatment process was employed. A remarkable modification of the device performance was noticed as a result of plasma treatment. These modifications are representative in a decrease of series resistance and an increase of photoresponsivity and specific detectivity. The process of plasma treatment achieved an increment of external quantum efficiency from 5.53% to 8.34% at −3.5 V under UV illumination.

Antioxidant Properties of Methanolic Extracts from Leaves of Rhazya stricta

Shahid Iqbal,M.I. Bhanger,Mubeena Akhtar,Farooq Anwar,Khawaja Raees Ahmed,Tabraz Anwer 한국식품영양과학회 2006 Journal of medicinal food Vol.9 No.2

Because of increased safety concerns about synthetic antioxidants, exploitation of cheaper and safer sourcesof antioxidants based on natural origin is the focus of research nowadays. Rhazya stricta is a medicinally important plant na-tive to South Asia. Extraction of antioxidants was carried out in different solvent systems, i.e., water, 80% methanol, 70%ethanol, and diethyl ether. The methanolic extract exhibited the highest total phenolic content among the extracts; thereforefor further studies the methanolic extract was employed. Antioxidant activity measurement in the linoleic acid system, metalchelating activity, reducing power, scavenging effect on 1,1-diphenyl-2-picrylhydrazyl free radical, and superoxide anion rad-ical scavenging activity were taken as the parameters for assessment of antioxidant potential of methanolic extracts. Resultswere compared with .-tocopherol and the synthetic antioxidant butylated hydroxyanisole. The antioxidant potential of methano-lic extracts of R. strictaleaves was comparable with previously exploited potent antioxidants and is strongly concentrationdependent.

SHIELD DESIGN OF CONCRETE WALL BETWEEN DECAY TANK ROOM AND PRIMARY PUMP ROOM IN TRIGA FACILITY

Khan, M J H,Rahman, M,Ahmed, F U,Bhuiyan, S I,Haque, A,Zulquarnain, A The Korean Association for Radiation Protection 2007 방사선방어학회지 Vol.32 No.4

The objective of this study is to recommend the radiation protection design parameters from the shielding point of view for concrete wall between the decay tank room and the primary pump room in TRIGA Mark-II Research Reactor Facility. The shield design for this concrete wall has been performed with the help of Point-kernel Shielding Code Micro-Shield 5.05 and this design was also validated based on the measured dose rate values with Radiation Survey Meter (G-M Counter) considering the ICRP-60 (1990) recommendations for occupational dose rate limit ($10{\mu}Sv/hr$). The recommended shield design parameters are: (i) thickness of 114.3 cm Ilmenite-Magnetite Concrete (IMC) or 129.54 cm Ordinary Reinforced Concrete (ORC) for concrete wall A (ii) thickness of 66.04 cm Ilmenite-Magnetite Concrete (IMC) or 78.74 cm Ordinary Reinforced Concrete (ORC) for concrete wall B and (iii) door thickness of 3.175 cm Mild Steel (MS) on the entrance of decay tank room. In shielding efficiency analysis, the use of I-M concrete in the design of this concrete wall shows that it reduced the dose rate by a factor of at least 3.52 times approximately compared to ordinary reinforced concrete.

Syntheses of 3-Pyrimidyl- and 3-Pyranyl-5,6-benzocoumarin Derivatives

El-Deen, Ibrahim M.,Al-Wakeel, El-Sayed I.,El-Mawla, Ahmed G. Korean Chemical Society 2002 Bulletin of the Korean Chemical Society Vol.23 No.4

A competitive enzyme-linked immunosorbent assay (ELISA) was developed for the quantitative detection of organophosphorus insecticide cyanophos. An analogue (hapten) of cyanophos was synthesized and was coupled to BSA to produce polyclonal antibodi es from rabbits. The antisera were screened against another hapten coupled to ovalbumin (OVA). Using the sera of highest specificity, an antigen-coated ELISA was developed, which showed an I50 of 310 ng/mL with the detection limit of 20 ng/mL. The antibodies showed negligible cross-reactivities with other organophosphorus pesticides except for parathion-methyl, which makes the assay suitable for the selective detection of cyanophos.

Effect of annealing treatment on the uniformity of CeO2/TiO2 bilayer resistive switching memory devices

M. Ismail,A.M. Rana,S.-U. Nisa,F. Hussain,M. Imran,K. Mahmood,I. Talib,E. Ahmed,D.H. Bao 한국물리학회 2017 Current Applied Physics Vol.17 No.10

Bilayer CeO2/TiO2 films with high-k dielectric property were prepared by rf magnetron sputtering technique at room temperature. Effect of annealing treatment on resistive switching (RS) properties of bilayer CeO2/TiO2 films in O2 ambient at different temperature in the range of 350e550 C was investigated. Our results revealed that the bilayer films had good interfacial property at 500 C and this annealing temperature is optimum for different RS characteristics. Results showed that bilayer CeO2/TiO2 film perform better uniformity and reliability in resistive switching at intermediate temperature (i.e. 450 C and 500 C) instead of low and high annealing temperature (i.e. 350 C and 550 C) at which it exhibits poor crystalline structure with more amorphous background. Less Gibbs free energy of TiO2 as compared to CeO2 results in an easier re-oxidation of the filament through the oxygen exchange with TaN electrode. However, the excellent endurance property (>2500 cycles), data retentions (105 s) and good cycle-to-cycle uniformity is observed only in 500 C annealed devices. The plots of cumulative probability, essential memory parameter, show a good distribution of Set/Reset voltage.

Elliptic flow of identified hadrons in Pb-Pb collisions at s N N = 2.76 $$ \sqrt{s_{\mathrm{NN}}}=2.76 $$ TeV

Abelev, B.,Adam, J.,Adamová,, D.,Aggarwal, M. M.,Agnello, M.,Agostinelli, A.,Agrawal, N.,Ahammed, Z.,Ahmad, N.,Ahmed, I.,Ahn, S. U.,Ahn, S. A.,Aimo, I.,Aiola, S.,Ajaz, M.,Akindinov, A.,Alam, S. Institute of Physics Pub 2015 The journal of high energy physics Vol.2015 No.6

<P>The elliptic flow coefficient (v(2)) of identified particles in Pb-Pb collisions at root s(NN) = 2.76 TeV was measured with the ALICE detector at the Large Hadron Collider (LHC). The results were obtained with the Scalar Product method, a two-particle correlation technique, using a pseudo-rapidity gap of |Delta eta| > 0.9 between the identified hadron under study and the reference particles. The v (2) is reported for pi(+/-), K-+/-, K-S(0), p+(p) over bar, phi, Lambda+(Lambda) over bar, Xi+(Xi) over bar (+) and Omega(-)+(Omega) over bar (+) in several collision centralities. In the low transverse momentum (p(T)) region, p(T) < 3 GeV/c, v(2)(p(T)) exhibits a particle mass dependence consistent with elliptic flow accompanied by the transverse radial expansion of the system with a common velocity field. The experimental data for pi (+/-) and the combined K-+/- and K-S(0) results, are described fairly well by hydrodynamic calculations coupled to a hadronic cascade model (VISHNU) for central collisions. However, the same calculations fail to reproduce the v(2)(p(T)) for p+(p) over bar, phi, Lambda+(Lambda) over bar, Xi+(Xi) over bar (+). For transverse momentum values larger than about 3 GeV/c, particles tend to group according to their type, i.e. mesons and baryons. The present measurements exhibit deviations from the number of constituent quark (NCQ) scaling at the level of +/- 20% for p(T) > 3 GeV/c.</P>

<i>Commiphora molmol</i> Modulates Glutamate-Nitric Oxide-cGMP and Nrf2/ARE/HO-1 Pathways and Attenuates Oxidative Stress and Hematological Alterations in Hyperammonemic Rats

Mahmoud, Ayman M.,Alqahtani, Sultan,Othman, Sarah I.,Germoush, Mousa O.,Hussein, Omnia E.,Al-Basher, Gadh,Khim, Jong Seong,Al-Qaraawi, Maha A.,Al-Harbi, Hanan M.,Fadel, Abdulmannan,Allam, Ahmed A. Hindawi 2017 Oxidative medicine and cellular longevity Vol.2017 No.-

<P>Hyperammonemia is a serious complication of liver disease and may lead to encephalopathy and death. This study investigated the effects of <I>Commiphora molmol</I> resin on oxidative stress, inflammation, and hematological alterations in ammonium chloride- (NH<SUB>4</SUB>Cl-) induced hyperammonemic rats, with an emphasis on the glutamate-NO-cGMP and Nrf2/ARE/HO-1 signaling pathways. Rats received NH<SUB>4</SUB>Cl and <I>C. molmol</I> for 8 weeks. NH<SUB>4</SUB>Cl-induced rats showed significant increase in blood ammonia, liver function markers, and tumor necrosis factor-alpha (TNF-<I>α</I>). Concurrent supplementation of <I>C. molmol</I> significantly decreased circulating ammonia, liver function markers, and TNF-<I>α</I> in hyperammonemic rats. <I>C. molmol</I> suppressed lipid peroxidation and nitric oxide and enhanced the antioxidant defenses in the liver, kidney, and cerebrum of hyperammonemic rats. <I>C. molmol</I> significantly upregulated Nrf2 and HO-1 and decreased glutamine and nitric oxide synthase, soluble guanylate cyclase, and Na<SUP>+</SUP>/K<SUP>+</SUP>-ATPase expression in the cerebrum of NH<SUB>4</SUB>Cl-induced hyperammonemic rats. Hyperammonemia was also associated with hematological and coagulation system alterations. These alterations were reversed by <I>C. molmol</I>. Our findings demonstrated that <I>C. molmol</I> attenuates ammonia-induced liver injury, oxidative stress, inflammation, and hematological alterations. This study points to the modulatory effect of <I>C. molmol</I> on glutamate-NO-cGMP and Nrf2/ARE/HO-1 pathways in hyperammonemia. Therefore, <I>C. molmol</I> might be a promising protective agent against hyperammonemia.</P>

Elucidating Molecular Structures of Nonalkylated and Short-Chain Alkyl (<i>n</i> < 5, (CH₂)_<i>n</i>) Aromatic Compounds in Crude Oils by a Combination of Ion Mobility and Ultrahigh-Resolution Mass Spectrometries and Theoretical Coll

Ahmed, Arif,Cho, Yunju,Giles, Kevin,Riches, Eleanor,Lee, Jong Wha,Kim, Hugh I.,Choi, Cheol Ho,Kim, Sunghwan American Chemical Society 2014 ANALYTICAL CHEMISTRY - Vol.86 No.7

<P>Ultrahigh-resolution mass spectrometry has allowed the determination of elemental formulas of the compounds comprising crude oils. However, elucidating molecular structures remains an analytical challenge. Herein, we propose and demonstrate an approach combining ion mobility mass spectrometry (IM-MS), ultrahigh-resolution mass spectrometry, and theoretical collisional cross-section (CCS) calculations to determine the molecular structures of aromatic compounds found in crude oils. The approach is composed of three steps. First, chemical structures are suggested based on the elemental formulas determined from ultrahigh-resolution mass spectra. Second, theoretical CCS values are calculated based on these proposed structures. Third, the calculated CCS values of the proposed structures are compared with experimentally determined CCS values from IM-MS data to provide proposed structures. For proof of concept, 31 nonalkylated and short-chain alkyl (<I>n</I> < 5, (CH<SUB>2</SUB>)<SUB><I>n</I></SUB>) aromatic compounds commonly observed in crude oils were analyzed. Theoretical and experimental CCS values matched within a 5% RMS error. This approach was then used to propose structures of compounds in selected <I>m</I>/<I>z</I> regions of crude oil samples. Overall, the combination of ion mobility mass spectrometry, ultrahigh-resolution mass spectrometry, and theoretical calculations was shown to be a useful tool for elucidating chemical structures of compounds in complex mixtures.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/ancham/2014/ancham.2014.86.issue-7/ac4032737/production/images/medium/ac-2013-032737_0004.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/ac4032737'>ACS Electronic Supporting Info</A></P>

Magnetic oxide thin solid films deposited at room temperature under ambient pressure using an electro-spray method

Ali, Ahmed I.,Kim, Yong Soo Elsevier 2017 Materials research bulletin Vol.96 No.3

<P><B>Abstract</B></P> <P>The deposition and characterization of magnetic metal-oxide, Eu<SUB>1−<I>x</I> </SUB>Sr<SUB> <I>x</I> </SUB>CoO<SUB>3</SUB> (<I>x</I> =0.2, 0.5) thin films using an electrostatic spray method are presented. The nano-sized particles were electro-sprayed from a colloidal suspension onto Pt/TiO<SUB>2</SUB>/SiO<SUB>2</SUB>/Si substrates at room temperature under ambient pressure. X-ray diffraction patterns showed a perovskite tetragonal structure with an <I>I</I>4/<I>mmm</I> space group. Optical and scanning electron microscopy of the thin films revealed their crack-free and uniform nature. The temperature-dependent magnetization showed a ferromagnetic-paramagnetic transition above 350K. Magnetic moments hysteresis loops demonstrate that the thin films exhibited a hard ferromagnetic state at 10K and a soft ferromagnetic one at room temperature. The Hall measurement revealed metallic behavior at room temperature, confirming the transition from a metallic state to an insulating one at <I>T</I> >300K. The correlation is explained based on the double exchange interaction and spin state transitions at both low and high temperatures.</P> <P><B>Highlights</B></P> <P> <UL> <LI> We grow magnetic metal-oxide Eu<SUB>1−<I>x</I> </SUB>Sr<SUB> <I>x</I> </SUB>CoO<SUB>3</SUB> (<I>x</I> =0.2, 0.5) thin films using an electrospray method in room temperature and ambient pressure. </LI> <LI> Eu<SUB>1−<I>x</I> </SUB>Sr<SUB> <I>x</I> </SUB>CoO<SUB>3</SUB> (<I>x</I> =0.2, 0.5) thin films exhibited a hard ferromagnetic state at 10K and a soft ferromagnetic one at room temperature. </LI> <LI> The magnetic measurements revealed ferromagnetic-paramagnetic transitions at Curie temperatures above 350K, which confirmed room temperature ferromagnetic states in Eu<SUB>1−<I>x</I> </SUB>Sr<SUB> <I>x</I> </SUB>CoO<SUB>3</SUB>. </LI> <LI> Electrical data measurements using Hall system shows room temperature metallic states in Eu<SUB>1−<I>x</I> </SUB>Sr<SUB> <I>x</I> </SUB>CoO<SUB>3</SUB>. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>Eu<SUB>1−<I>x</I> </SUB>Sr<SUB> <I>x</I> </SUB>CoO<SUB>3</SUB> (<I>x</I> =0.5) thin films deposited by electrostatic spray method at room temperature and ambient pressure have ferromagnetic–paramagnetic transitions at Curie temperatures above 350K and 40emu/cm<SUP>3</SUP> of saturated magnetic moments at 10K.▪</P>