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91.
Cationic antimicrobial peptides are potent inhibitors of growth of a broad spectrum of micro-organisms but often have large cytotoxic effects. We prepared some novel sugar amino acid containing cyclic cationic peptides and their Au nanoparticle attached counterparts and studied their antimicrobial activities and cytotoxic behaviour, including an investigation of the mechanism of the cytotoxicity. 相似文献
92.
A new probe (Z)-3-((naphthalen-1-ylmethylene)amino)phenol has been synthesized by condensation reaction between 1-naphthaldehyde and 3-aminophenol for the fluorescent sensing of Ce3+ by “on” mode and dichromate (Cr2O72?) by “off” mode. Metal ions—Ag+, Al3+, As3+, Ba2+, Ca2+, Cd2+, Ce4+, Co2+, Cr3+, Cr6+, Cu2+, Fe2+, Fe3+, Hg2+, K+, La+, Li+, Mg2+, Mn2+, Na+, Ni2+, Pb2+, Zn2+and anions Br?, C2O42?, CH3COO?, Cl?, CO32?, F?, H2PO4?, HCO3?, HF2?, HPO42?, I?, MnO4?, NO3?, OH?, S2?, S2O32?, SCN?, SO42? do not interfere. The limit of detection (LOD) for sensing Ce3+ and Cr2O72? ions are 1.286?×?10–7 M and 6.425?×?10–6 M, respectively.
相似文献93.
Arenes, heteroarenes, 1,3-dicarbonyls and organosilicon nucleophiles undergo highly efficient alkylation with allylic, propargylic and benzylic alcohols in the presence of a new 'Pd-Sn' bimetallic catalyst in nitromethane; water being the sole byproduct. The plausible mechanism of alkylation and the intermediacy of ether has been enumerated. 相似文献
94.
Abhijit Pal Bhaskar Biswas Sunil Kanti MondalChia-Her Lin Rajarshi Ghosh 《Polyhedron》2012,31(1):671-675
The synthesis and X-ray structural characterisation of a new Cu(II) complex, [Cu(L1)Cl](ClO4)·CH3OH (1) [L1 = N,N′-bis((pyridine-2-yl)phenylidene)-1,3-diaminopropan-2-ol], has been described in this work. The structural study reveals that the Cu(II) centre in 1 has a square pyramidal geometry with a trigonality index τ = 0.43, being coordinated by the organic ligand and a chloro group. The interaction of complex 1 and another complex previously reported by our group, [Cu(L2)](ClO4)2 (2) [L2 = N-(1-pyridin-2-yl-phenylidene)-N′-[2-({2-[(1-pyridin-2-ylphenylidene)amino]ethyl}amino)ethyl]ethane-1,2diamine], with calf thymus DNA (CT-DNA) has been investigated using absorption and emission spectral studies. The binding constant (Kb) and the linear Stern-Volmer quenching constant (Ksv) have been determined. 相似文献
95.
Sahana A Banerjee A Guha S Lohar S Chattopadhyay A Mukhopadhyay SK Das D 《The Analyst》2012,137(7):1544-1546
An indole based naphthalene derivative is reported as a highly selective fluorescent probe for azide ion in aqueous ethanol. The probe is applied for cell imaging of the N(3)(-) ion in contaminated living cells. Both experimental and theoretical studies have been performed to figure out the plausible mechanism of fluorescence enhancement of the probe upon binding with N(3)(-). 相似文献
96.
A new easy-to-synthesize chemosensor, 3,3'-bis(indolyl)-4-chlorophenylmethane (hereafter S), was designed, synthesized and employed as a selective optical chemosensor for fluoride ions.(1)H NMR and density functional studies on the system have been carried out to determine the nature of the interaction between S and X(-) (X = inorganic anions) responsible for the significant fluoride-induced changes in the absorption properties of S. The experimental results reveal that abstraction of an acidic proton of S by the fluoride ion, leading to the formation of anionic species, is responsible for the spectral changes. These changes allow signaling for the fluoride ion to detect and estimate the concentration of fluoride ion present even at the submicromolar level, accurate up to 2 μM. Calculations of the transition energies of S, S(-), and S···F(-) (hydrogen bonded complex) show that only S(-) is responsible for the long-wavelength absorption band in the presence of F(-). 相似文献
97.
Sourav Kanti Jana Alessia Le Donne Simona Binetti 《Journal of Physics and Chemistry of Solids》2012,73(2):143-147
Photovoltaics is the most promising technology for the future of green energy production. To fully realize the potential use of photovoltaic technology, low manufacturing cost and high working photoconversion efficiency must be obtained. Light trapping by metal nanoparticles is an attractive strategy in thin film as well as in bulk silicon solar cells aimed to confine light within the active layer to promote the photon absorption and therefore achieving higher efficiency. In this paper, we tested the deposition of silver and gold nanoparticles on bulk silicon solar cells by colloidal technique in order to enhance their photovoltaic conversion efficiency by means of Plasmonic Light Scattering by metal nanoparticles. The feasible Plasmonic Light Scattering related enhancement was examined using spectral response and I–V measurements. Relative increases of the total delivered power under simulated solar irradiation were observed for cells both with and without antireflection coating using silver and gold nanoparticles. 相似文献
98.
Mrinal Kanti Roychowdhury 《Israel Journal of Mathematics》2012,192(1):473-488
The quantization dimension function for a probability measure supported on the limit set generated by a set of contractive bi-Lipschitz mappings is determined. The relationship between the quantization dimension function and the temperature function of the thermodynamic formalism arising in multifractal analysis is established. 相似文献
99.
The present paper discusses magnetic confinement of the Dirac excitations in graphene in the presence of inhomogeneous magnetic fields. In the first case a magnetic field directed along the z axis whose magnitude is proportional to 1/r is chosen. In the next case we choose a more realistic magnetic field which does not blow up at the origin and gradually fades away from the origin. The magnetic fields chosen do not have any finite/infinite discontinuity for finite values of the radial coordinate. The novelty of the two magnetic fields is related to the equations which are used to find the excited spectra of the excitations. It turns out that the bound state solutions of the two-dimensional hydrogen atom problem are related to the spectra of graphene excitations in the presence of the 1/r (inverse-radial) magnetic field. For the other magnetic field profile one can use the knowledge of the bound state spectrum of a two-dimensional cutoff Coulomb potential to dictate the excitation spectra of graphene. The spectrum of the graphene excitations in the presence of the inverse-radial magnetic field can be exactly solved while the other case cannot be. In the later case we give the localized solutions of the zero-energy states in graphene. 相似文献
100.
We study the electrical transport properties of a two-dimensional electron gas (2DEG) with the Rashba spin-orbit interaction in the presence of a constant perpendicular magnetic field (B(0)( ?z) which is weakly modulated by B1 = B1 cos(qx) ?z, where B(1) ? B(0) and q = 2π/a with a the modulation period. We obtain the analytical expressions of the diffusive conductivities for spin-up and spin-down electrons. The conductivities for spin-up and spin-down electrons oscillate with different frequencies and produce beating patterns in the amplitude of the Weiss and Shubnikov-de Haas oscillations. We show that the Rashba strength can be determined by analyzing the beating pattern in the Weiss oscillation. We find a simple equation which determines the Rashba spin-orbit interaction strength if the number of Weiss oscillations between any two successive nodes is known from the experiment. We compare our results with the electrically modulated 2DEG with the Rashba interaction. For completeness, we also study the beating pattern formation in the collisional and the Hall conductivities. 相似文献