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51.
52.
Murugan Veerapandian Suk Kyung Lim Hyang Mi Nam Gobianand Kuppannan Kyusik S. Yun 《Analytical and bioanalytical chemistry》2010,398(2):867-876
We report the analytical and in vitro antibacterial activity of glucosamine-functionalized silver glyconanoparticles. Morphological
characterization ensured the surface topography and particle size distribution of both silver and glucosamine–silver nanoparticles.
Surface plasmon resonance of both types of nanoparticle was determined from UV–visible spectroscopy using four different sample
concentrations (10–40 μL). The resulting functionalized glyconanoparticles show maximum absorbance with a red shift of 30 ± 5 nm
(390–400 nm) from their initial absorbance (425–430 nm). FT-Raman and 1H-NMR spectroscopic measurement confirmed the surface functionalization of glucosamine on the silver surface through the carbonyl
group of a secondary amide linkage (–NH–CO–), elucidated by the conjugation of N-hydroxysuccinimide (NHS)-terminated silver nanoparticles and the amino group of glucosamine. Antimicrobial experiments with
well-characterized silver nanoparticles (AgNPs) and glucosamine-functionalized silver nanoparticles (GlcN-AgNPs) demonstrate
that GlcN-AgNPs have similar and enhanced minimum inhibitory concentration (MIC) against eight gram-negative and eight gram-positive
bacteria compared with AgNPs. MIC data shows that Klebsiella pneumoniae (ATCC 700603) and Bacillus cereus isolate express high levels of inhibition, with the quantity and magnitude of inhibition being higher in the presence of
GlcN-AgNPs. 相似文献
53.
A. I. Oreshkin R. Z. Bakhtizin P. Murugan V. Kumar N. Fukui T. Hashizume T. Sakurai 《JETP Letters》2010,92(7):449-452
Spatially resolved images of an individual C60F18 fluorofullerene molecule on Si(100) − 2 × 1 surface have been obtained using scanning tunneling microscopy. Scanning tunneling
microscopy results and ab initio calculations show that the fluorofullerene molecules interact with the Si(100) − 2 × 1 surface
with F atoms pointing down towards the surface. The adsorption energy of a C60F18 molecule on Si(100) − 2 × 1 surface is ∼12.1 eV, which is much higher than the adsorption energy of the same molecule on
Si(111) − 7 × 7 surface (6.65 eV). C60F18 molecules are located in the troughs in-between the dimer rows occupying the four-dimer site on Si(100) − 2 × 1 surface. 相似文献
54.
M. Thambidurai N. Muthukumarasamy S. Agilan N. Murugan N. Sabari Arul S. Vasantha R. Balasundaraprabhu 《Solid State Sciences》2010,12(9):1554-1559
Fe doped CdS quantum dots have been prepared using simple precursors by chemical precipitation technique. Fe doped CdS quantum dots have been synthesized by mixing cadmium nitrate, sodium sulfide and adding Fe under suitable conditions. X-ray diffraction analysis reveals that undoped and Fe doped CdS crystallizes in hexagonal structure. The lattice constants of Fe doped CdS nanoparticles decreased slightly with incorporation of Fe and no secondary phase was observed. The average grain size of the nanoparticles is found to lie in the range of 2.8–4.2 nm. HRTEM results show that undoped and 3.75% Fe doped CdS nanoparticles exhibit a uniform size distribution and average size of the nanoparticles is about 2–3 nm. Raman spectra show that 1LO and 2LO peaks of the Fe doped CdS samples are slightly red shifted compared with those of undoped CdS. Optical absorption spectra of Fe doped CdS nanoparticles exhibited red shift. 相似文献
55.
Eagambaram Murugan Rajmohan Rangasamy 《Journal of polymer science. Part A, Polymer chemistry》2010,48(12):2525-2532
We report here, the synthesis of two types of heterogeneous nanoparticle catalysts viz., polymer‐supported poly(propyleneimine)‐G2 dendrimer stabilized gold nanoparticle catalysts using crosslinked poly(4‐vinylpyridine) matrix (PSP4VP) as support material. The grafting of dendrimer on the surface of P4VP beads was characterized by FTIR spectrophotometer and CHN analyses. The immobilization of AuNPs was characterized by UV‐Vis spectrum, SEM, and HRTEM studies. The resultant polymer‐supported dendrimer stabilized AuNPs were used as a heterogeneous catalyst for the reduction of 4‐nitrophenol. The catalytic activity is found to be excellent and it can also be reused many times by simple filtration and activity remains maintained. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 2525–2532, 2010 相似文献
56.
Arul Murugan N 《The Journal of chemical physics》2005,123(24):244514
The effect of pressure on the structure and reorientational motion of molecules in orientationally disordered (OD) crystalline phase of cubane has been investigated in detail using variable shape molecular simulations in constant-pressure constant-temperature ensemble. Complete orientational ordering occurs at a pressure of 1.0 GPa and the OD phase transforms to an orientationally ordered phase at this pressure. The transition is associated with a kink in the variation of structural parameters such as cell parameters, unit-cell volume, and interaction energy. This transition is also associated with an anomaly in specific heat. Above this transition pressure, the structural quantities display only smaller changes with further increase in pressure. The structure of high-pressure orientationally ordered (HPOO) phase has been characterized using radial distribution functions and orientational distribution function. From detailed analysis of the structure of HPOO phase we conclude that it is isostructural with low-temperature orientationally ordered phase. The OD phase has four times larger compressibility than the HPOO phase. 相似文献
57.
Three different interaction potentials existing in the literature along with a model proposed here have been used to model p-terphenyl under standard conditions. Of these, the model that predicts the room-temperature crystal structure well has been used to understand the behavior of p-terphenyl under pressure. Lattice parameters show good agreement with the X-ray diffraction values reported by Puschnig et al. (Puschnig, P.; Heimel, G.; Weinmeier, K.; Resel, R.; Ambrosch-Draxl, C. High Pressure Res. 2002, 22, 105). The nonplanar structure of p-terphenyl transforms to a planar structure with gradual disappearance of disorder associated with ring flipping. We show that the transformation is accompanied by a change in the potential energy profile from W-shaped to a U-shaped form, which is associated with complete planarization between 1.0 and 1.5 GPa. Our results reported here are in excellent agreement with X-ray diffraction results which also suggest the existence of a similar transition as a function of pressure in polyphenyls such as biphenyl and p-hexaphenyl. Interestingly, the amplitude of the torsional motion is largest at an intermediate pressure of 1.0 GPa. This is attributed to the rather flat potential energy landscape which occurs during the transition from W- to U-shaped potential. 相似文献
58.
Katritzky AR Scriven EF Majumder S Akhmedova RG Vakulenko AV Akhmedov NG Murugan R Abboud KA 《Organic & biomolecular chemistry》2005,3(3):538-541
Nitration of pyridines 1a-o with nitric acid in trifluoroacetic anhydride, gave the corresponding 3-nitropyridines 6a-n in yields of 10-83%. 相似文献
59.
60.
Journal of Statistical Physics - We show that macro-molecular self-assembly can recognize and classify high-dimensional patterns in the concentrations of N distinct molecular species. Similar to... 相似文献