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91.
Sanjay K. Bharti Saurabh K. Patel Gopal Nath Ragini Tilak Sushil K. Singh 《Transition Metal Chemistry》2010,35(8):917-925
Six Cu(II) complexes of Schiff base ligands of arylidene-2-(4-(4-bromo/methoxy-phenyl)thiazol-2-yl) hydrazines have been synthesized,
characterized and screened for DNA cleavage and antimicrobial activities. The chemical structures of the complexes were deduced
by physicochemical and spectroscopic methods. Elemental analyses indicated that the stoichiometry of the complexes is CuL2 (L = Schiff base ligand). The DNA cleavage activities of the complexes were evaluated by agarose gel electrophoresis in the
presence and absence of oxidant (H2O2) and free radical scavenger (DMSO). All the six complexes showed significant nuclease activity in the presence of H2O2, and two of the complexes showed moderate nuclease activity even in the absence of oxidant. The complexes did not show nuclease
activity in the presence of free radical scavenger. The compounds were tested for activity against selected bacteria and fungi. 相似文献
92.
Kinsuk Das Tarak Nath Mandal Somnath Roy Samik Gupta Anil Kumar Barik Partha Mitra Arnold L. Rheingold Susanta Kumar Kar 《Polyhedron》2010
The varying coordination modes of the title ligand, L [5-methyl-1-(pyridin-2-yl)-N′-[pyridin-2-ylmethylidene]pyrazole-3-carbohydrazide] towards the different metal centers is reported by preparation and characterization of Cu(II), Zn(II) and Cd(II) complexes, [Cu(L)NO3.H2O](NO3) (1) [Zn(L)2](ClO4)2·2DMF (2) and [Cd(L)(I)2] (3) respectively. In 1, the neutral ligand serves as tetradentate 4 N donor where both pyridine and pyrazole nitrogen atoms of pyridyl–pyrazole part are coordinatively active, leaving the carbonyl oxygen of the carbohydrazide part inactive. The same pyridine and pyrazole N atoms remain abstained from the coordination process towards the Zn(II) and Cd(II) metal centers. For 2 and 3 the ligand behaves as a tridentate NNO donor where the two nitrogen atoms come from azomethine, pyridine of pyridine-2-carbaldehyde parts and O from carbonyl oxygen atoms (carbohydrazide part). The complex 1 and 2 are distorted octahedral while complex 3 adopts distorted square pyramidal geometry. All the complexes are X-ray crystallographically characterized. 相似文献
93.
94.
Tri-state logic plays a significant role in carry free arithmetical operation. Design of all-optical scheme of three basic tri-state logical operation (NOT, AND, OR) with the help of polarization encoded semiconductor optical amplifier (SOA)-assisted Sagnac interferometric switch has been studied and investigated in this present paper. Numerical simulation is also presented, which verifies the theoretical results. Insertion loss, contrast ratio, extinction ratio, amplitude modulation, bit error rate and signal to noise ratio values have also been analyzed. 相似文献
95.
Kumar Nagesh Varma G. D. Nath R. Srivastava A. K. 《Applied Physics A: Materials Science & Processing》2011,104(4):1169-1174
In this paper we report a simple method that enables the easy fabrication of ordered ZnO nanowire arrays using Anodic Aluminium
Oxide (AAO) template. We have used a vacuum injection technique to fill solution into the pores of an AAO template. The AAO
template has been fabricated by a two-step anodization process using 0.3 M oxalic acid (H2C2O4) solution under a constant voltage of 40 V. The AAO template formed through this process has been detached from Al substrate
via an anodic voltage pulse using perchloric acid (HClO4) solution (70%). The nanowires of ZnO have been synthesized by injecting the saturated Zn(NO3)2 solution into the pores of the detached AAO template using a vacuum pump. The ZnO nanowires synthesized by this technique
have been found dense & continuous with uniform diameter throughout the length of the wire. The structural characteristics
of AAO template and ZnO nanowires have been studied by Field Emission Scanning Electron Microscope (FESEM), Atomic force microscope
(AFM) and Transmission Electron Microscope (TEM). 相似文献
96.
Sukanta Kumar DashAmar Nath Samanta Syamalendu S. Bandyopadhyay 《Fluid Phase Equilibria》2011,307(2):166-174
In this work, new experimental results of the vapour-liquid equilibrium (VLE) of CO2 in aqueous 2-amino-2-methyl-1-propanol (AMP) and piperazine (PZ) have been presented in the temperature range of 298-328 K and PZ concentration range of 2-8 mass%, keeping the total amine concentration in the solution at 30 mass%. The partial pressures of CO2 were in the range of 0.1-1450 kPa. A thermodynamic model was developed to correlate and predict the VLE of CO2 in aqueous AMP + PZ. The electrolyte nonrandom two liquid (ENRTL) theory has been used to develop the VLE model for the quaternary system (CO2 + AMP + PZ + H2O) to describe the equilibrium behaviour of the solution. The experimental data from this work and data available in the literature were used to regress the ENRTL interaction parameters. The model predictions are in good agreement with the experimental data of CO2 solubility in aqueous blends of this work as well as those reported in the literature. The current model can also predict speciation, heat of absorption, pH of the CO2 loaded solution, and amine volatility. 相似文献
97.
The degradation of neurotransmitters is a hallmark feature of Alzheimer''s disease (AD). Copper bound Aβ peptides, invoked to be involved in the pathology of AD, are found to catalyze the oxidation of serotonin (5-HT) by H2O2. A combination of EPR and resonance Raman spectroscopy reveals the formation of a Cu(ii)–OOH species and a dimeric, EPR silent, Cu2O2 bis-μ-oxo species under the reaction conditions. The Cu(ii)–OOH species, which can be selectively formed in the presence of excess H2O2, is the reactive intermediate responsible for 5-HT oxidation. H2O2 produced by the reaction of O2 with reduced Cu(i)–Aβ species can also oxidize 5-HT. Both these pathways are physiologically relevant and may be involved in the observed decay of neurotransmitters as observed in AD patients.The mononuclear copper hydroperoxo species (Cu(ii)–OOH) of Cu–Aβ is the active oxidant responsible for serotonin oxidation by Cu–Aβ in the presence of physiologically relevant oxidants like O2 and H2O2, which can potentially cause oxidative degradation of neurotransmitters, a marker of Alzheimer''s disease. 相似文献
98.
99.
Amar Nath Vladimir Chechersky Robert Butterick Jr.III Steve Preite 《Solid State Communications》2006,138(5):224-228
The magnetic behavior of the Sr0.3 manganite is studied using a local microprobe, 57Co. In contrast with Ca substituted manganites, a much larger fraction of the material exhibits short-range order with superparamagnetic-like behavior even at 80 K. The differences in behavior are attributed to the large mismatch between the ionic radii of La+3 and the divalent substituent Sr+2, which introduces anharmonicity in local vibrations. In common with all other compounds exhibiting negative bulk magnetoresistivity, the Sr0.3 compound also exhibits very marked softening of lattice as one approaches Tc from below. Application of an external magnetic field results in coalescing of nanosized magnetic clusters to form larger ones with better alignment of spins. 相似文献
100.
An analysis is carried out to study the effects of localized heating (cooling), suction (injection), buoyancy forces and magnetic field for the mixed convection flow on a heated vertical plate. The localized heating or cooling introduces a finite discontinuity in the mathematical formulation of the problem and increases its complexity. In order to overcome this difficulty, a non-uniform distribution of wall temperature is taken at finite sections of the plate. The nonlinear coupled parabolic partial differential equations governing the flow have been solved by using an implicit finite-difference scheme. The effect of the localized heating or cooling is found to be very significant on the heat transfer, but its effect on the skin friction is comparatively small. The buoyancy, magnetic and suction parameters increase the skin friction and heat transfer. The positive buoyancy force (beyond a certain value) causes an overshoot in the velocity profiles.A
mass transfer constant
- B
magnetic field
- Cfx
skin friction coefficient in the x-direction
- Cp
specific heat at constant pressure, kJ.kg–1.K
- Cv
specific heat at constant volume, kJ.kg–1.K–1
- E
electric field
- g
acceleration due to gravity, 9.81 m.s–2
- Gr
Grashof number
- h
heat transfer coefficient, W.m2.K–1
- Ha
Hartmann number
- k
thermal conductivity, W.m–1.K
- L
characteristic length, m
- M
magnetic parameter
- Nux
local Nusselt number
- p
pressure, Pa, N.m–2
- Pr
Prandtl number
- q
heat flux, W.m–2
- Re
Reynolds number
- Rem
magnetic Reynolds number
- T
temperature, K
- To
constant plate temperature, K
- u,v
velocity components, m.s–1
- V
characteristic velocity, m.s–1
- x,y
Cartesian coordinates
-
thermal diffusivity, m2.s–1
-
coefficient of thermal expansion, K–1
- ,
transformed similarity variables
-
dynamic viscosity, kg.m–1.s–1
- 0
magnetic permeability
-
kinematic viscosity, m2.s–1
-
density, kg.m–3
-
buoyancy parameter
-
electrical conductivity
-
stream function, m2.s–1
-
dimensionless constant
-
dimensionless temperature, K
- w,
conditions at the wall and at infinity 相似文献