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71.
Vajiravelu Sivamurugan Velayutham Murugesan Valiyaveettil Suresh Muthaiyahpillai Palanichamy Ajayan Vinu 《Journal of heterocyclic chemistry》2007,44(4):973-977
72.
Effects of La-doping on structural,electrical and multiferroic properties of Bi6Fe2Ti3O18 thin films
Raghavan Chinnambedu Murugesan Kim Jin Won Choi Ji Ya Kim Sang Su Kim Jong-Woo 《Journal of Sol-Gel Science and Technology》2015,73(1):83-90
Journal of Sol-Gel Science and Technology - Bi6Fe2Ti3O18 (BFTO) and La-doped Bi6?xLaxFe2Ti3O18 (BLFT) (x = 0.03; BLFT3, x = 0.06; BLFT6 and 0.09; BLFT9)... 相似文献
73.
The goal of nanomaterials' surface modification using a biomaterial is to preserve the materials' bulk properties while modifying only their surface to possess desired recognition and specificity. Here, we have developed a phase-assisted, modified Brust-Schiffrin methodological synthesis of metallo nanocomplexes anchored by a peptide, N,N'-(1,3-propylene)-bis-hippuricamide. The spectral, thermal and morphological characterizations assure the formation of nanocomplexes. Therapeutic behavior of all the nanocomplexes has been well sighted by evaluating their DNA unpacking skills. In addition, we demonstrate their biological inspiration by targeting few bacterial and fungal strains. The in vitro antimicrobial investigation reports that all the nanocomplexes disrupt microbial cell walls/membranes efficiently and inhibit the growth of microbes. These sorts of nanocomplexes synthesized in large quantities and at low cost, deliver versatile biomedical applications, and can be used to treat various diseases which may often cause high mortality. 相似文献
74.
Murugesan Vairalakshmi Veerian Raj Ponnusamy Sami Kasi Rajasekaran 《Transition Metal Chemistry》2011,36(8):875-882
The kinetics of oxidation of phenol and a few ring-substituted phenols by heteropoly 11-tungstophosphovanadate(V), [PVVW11O40]4− (HPA) have been studied spectrophotometrically in aqueous acidic medium containing perchloric acid and also in acetate buffers
of several pH values at 25 °C. EPR and optical studies show that HPA is reduced to the one-electron reduced heteropoly blue
(HPB) [PVIVW11O40]5−. In acetate buffers, the build up and decay of the intermediate biphenoquinone show the generation of phenoxyl radical (ArO·) in the rate-determining step. At constant pH, the reaction shows simple second-order kinetics with first-order dependence
of rate on both [ArOH] and [HPA]. At constant [ArOH], the rate of the reaction increases with increase in pH. The plot of
apparent second-order rate constant, k
2, versus 1/[H+] is linear with finite intercept. This shows that both the undissociated phenol (ArOH) and the phenoxide ion (ArO−) are the reactive species. The ArO−–HPA reaction is the dominant pathway in acetate buffer and it proceeds through the OH− ion triggered sequential proton transfer followed by electron transfer (PT-ET) mechanism. The rate constant for ArO−–HPA reaction, calculated using Marcus theory, agrees fairly well with the experimental value. The reactivity of substituted
phenoxide ions correlates with the Hammett σ+ constants, and ρ value was found to be −4.8. In acidic medium, ArOH is the reactive species. Retardation of rate for the
oxidation of C6H5OD in D2O indicates breaking of the O–H bond in the rate-limiting step. The results of kinetic studies show that the HPA-ArOH reaction
proceeds through a concerted proton-coupled electron transfer mechanism in which water acts as proton acceptor (separated-CPET). 相似文献
75.
Gounder MK Lin H Stein M Goodin S Bertino JR Kong AN DiPaola RS 《Biomedical chromatography : BMC》2012,26(5):650-654
2‐Deoxyglucose (2‐DG), an analog of glucose, is widely used to interfere with glycolysis in tumor cells and studied as a therapeutic approach in clinical trials. To evaluate the pharmacokinetics of 2‐DG, we describe the development and validation of a sensitive HPLC fluorescent method for the quantitation of 2‐DG in plasma. Plasma samples were deproteinized with methanol and the supernatant was dried at 45°C. The residues were dissolved in methanolic sodium acetate–boric acid solution. 2‐DG and other monosaccharides were derivatized to 2‐aminobenzoic acid derivatives in a single step in the presence of sodium cyanoborohydride at 80°C for 45 min. The analytes were separated on a YMC ODS C18 reversed‐phase column using gradient elution. The excitation and emission wavelengths were set at 360 and 425 nm. The 2‐DG calibration curves were linear over the range of 0.63–300 µg/mL with a limit of detection of 0.5 µg/mL. The assay provided satisfactory intra‐day and inter‐day precision with RSD less than 9.8%, and the accuracy ranged from 86.8 to 110.0%. The HPLC method is reproducible and suitable for the quantitation of 2‐DG in plasma. The method was successfully applied to characterize the pharmacokinetics profile of 2‐DG in patients with advanced solid tumors. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
76.
Murugesan Velayudham Subramanian Singaravadivel Seenivasan Rajagopal Perumal Ramamurthy 《Journal of organometallic chemistry》2009,694(25):4076-4083
Six new homobimetallic and heterobimetallic complexes of rhenium(I) and ruthenium(II) bridged by ethynylene spacer [(CO)3(bpy)Re(BL)Re(bpy)(CO)3]2+ [Cl(bpy)2Ru(BL)Ru(bpy)2Cl]2+ and [(CO)3(bpy)Re(BL)Ru(bpy)2Cl]2+ (bpy = 2,2′-bipyridine, BL = 1,2-bis(4-pyridyl)acetylene (bpa) and 1,4-bis(4-pyridyl)butadiyne (bpb) are synthesized and characterized. The electrochemical and photophysical properties of all the complexes show a weak interaction between two metal centers in heterobimetallic complexes. The excited state lifetime of the complexes is increased upon introduction of ethynylene spacer and the transient spectra show that this is due to delocalization of electron in the bridging ligand. Also, intramolecular energy transfer from *Re(I) to Ru(II) in Re–Ru heterobimetallic complexes occurs with a rate constant 4 × 107 s−1. 相似文献
77.
Basic knowledge on the hydrodynamics in the spacer-filled spiral wound membrane (SWM) channel is vital for the understanding of the formation of concentration polarization at the membrane interface. In the present study, a 3D laminar transient hydrodynamics modeling approach was used to study and optimize the spacer mesh angle for the SWM feed spacer. Based on the simulated results, the optimal spacer mesh angle that yields the minimum effective concentration polarization factor, was found to be α120β30. Under this optimal mesh angles, spacer α120β30 also demonstrated the highest magnitude of unsteady hydrodynamics (which adjacent to the membrane wall) at a moderate degree of pressure loss. 相似文献
78.
Kalpana Murugesan Govindan Kadarkarai Selvasekarapandian Subramanian Premalatha Manavalan Senthil Kumar Parthasarathy 《Ionics》2017,23(10):2621-2629
Modified Pechini-type polymerizable precursor method has been used to prepare nanosized Li1-xTbxNiPO4 (x = 0, 0.03, 0.05, and 0.07) solid solutions to obtain homogeneous with controlled stoichiometry and smaller particle size. The reaction temperature was determined by thermogravimetric (TG/DTA) analysis. X-ray diffraction analysis reveals the formation of orthorhombic structure and the calculated crystallite sizes are found to be in the range of 75–89 nm. Morphological, compositional, and vibrational properties were performed by SEM, EDAX, and FTIR, respectively. Conductivity measurements were carried out at room temperature by AC impedance analysis. The Li0.97Tb0.03Ni0.99PO4 sample shows one order of higher conductivity than pure LiNiPO4. Higher concentration of terbium samples such as Li0.95Tb0.05Ni0.99PO4 and Li0.93Tb0.07Ni0.99PO4 lead to decrease of conductivity. The frequency dependency of dielectric permittivity, dielectric loss, and electric modulus of Li1-x TbxNiPO4 solid solutions are studied. The frequency-dependent plot of modulus reveals that the conductivity relaxation is of non-Debye type. 相似文献
79.
Benial AM Ichikawa K Murugesan R Yamada K Utsumi H 《Journal of magnetic resonance (San Diego, Calif. : 1997)》2006,182(2):273-282
DNP parameters relevant to Overhauser-enhanced magnetic resonance imaging (OMRI) are reported for a few nitroxyl radicals and their corresponding (15)N and (2)H enriched analogues, used in simultaneous imaging by OMRI. DNP enhancement was measured at 14.529 mT, using a custom-built scanner operating in a field-cycled mode, for different concentrations, ESR irradiation times and RF power levels. DNP enhancements increased with agent concentration up to 2.5 mM and decreased above 3 mM, in tune with ESR line broadening measured at X-band as a function of the agent concentration. The proton spin-lattice relaxation times (T(1)) measured at very low Zeeman field (14.529 mT) and the longitudinal relaxivity parameters were estimated. The relaxivity parameters were in good agreement with those independently computed from the linear region of the concentration dependent enhancement. The leakage factor showed an asymptotic increase with increasing agent concentration. The coupling parameters of (14)N- and (15)N-labeled carbamoyl-PROXYL showed the interaction between the electron and nuclear spins to be mainly dipolar in origin. Upon (2)H labeling, about 70% and 40% increases in enhancement for (15)N- and (14)N-labeled nitroxyl agents were observed, respectively. It is envisaged that the results reported here may enable better understanding of the factors determining DNP enhancement to design suitable 'beacons' for simultaneous molecular imaging by OMRI. 相似文献
80.
In the present report, ionic transport properties and microstructural investigations of superionic materials in a cost-effective glassy system xCuI–(100 ? x)[2Ag2O–0.7V2O5–0.3B2O3], where x = 30, 40, 45, 50 and 60, have been described. The temperature dependent electrical conductivity studies were carried out by ac impedance analysis. The microstructure of the materials studied by SEM indicated the presence of dispersed CuO and AgI micro-crystals in the silver oxysalt glass matrix. High room temperature electrical conductivity of 3.58 × 10?3 S cm?1 and low activation energy of 0.24 eV were obtained for the best conducting composition. The ac impedance data were analyzed using impedance and modulus formalisms. These materials show extremely high ti value of 0.999 and the ionic conductivity is apparently due to Ag+ ions only. The use of two glass formers helped to form materials with higher Tg, higher thermal stability and better ionic transport properties. 相似文献