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91.
In the last few years, hybrid systems consisting of punctual sources and metallic nanostructures have been assembled and studied. Furthermore, the radiative coupling between the two counterparts has become a crucial aspect to be explored in nanophotonics and plasmonics. In this paper a numerical framework based on the Discrete Dipole Approximation is presented as a simple computational scheme to analyze the decay dynamics of an emitter when it is located in the near proximities of metallic nanoparticles. This approach allows to go beyond the analytically solved cases and to predict the optical response of more complex shaped nanoparticles. Here the excitation of dipole and higher-order modes is studied as a function of the applied radiation with a particular attention paid to the changes induced in the response by approaching the source to the metal. Numerical results, obtained for Ag spheroids and conically shaped nanoparticles, are explained by analyzing the charge density induced on the surface of the nanoparticles, this allowing to distinguish dark from radiative modes in a straightforward way. 相似文献
92.
93.
Santanu Kumar Padhi Nicoletta Baglieri Valentina Bonino Angelo Agostino Lorenza Operti Nicolae Dan Batalu Mariana Carmen Chifiriuc Marcela Popa Mihail Burdusel Mihai Alexandru Grigoroscuta Gheorghe Virgil Aldica Dana Radu Petre Badica Marco Truccato 《Molecules (Basel, Switzerland)》2021,26(16)
We report for the first time on the antimicrobial activity of MgB2 powders produced via the Reactive Liquid Infiltration (RLI) process. Samples with MgB2 wt.% ranging from 2% to 99% were obtained and characterized, observing different levels of grain aggregation and of impurity phases. Their antimicrobial activity was tested against Staphylococcus aureus ATCC BAA 1026, Enterococcus faecalis ATCC 29212, Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853, and Candida albicans ATCC 10231. A general correlation is observed between the antibacterial activity and the MgB2 wt.%, but the sample microstructure also appears to be very important. RLI-MgB2 powders show better performances compared to commercial powders against microbial strains in the planktonic form, and their activity against biofilms is also very similar. 相似文献
94.
G. Chiarello V. Formoso E. Infusino A. Marino R.G. Agostino E. Colavita 《Surface science》2007,601(1):104-111
We present the results of high-resolution electron energy loss experiments on (CO/O)/Ni(1 0 0) and (CO/H)/Ni(1 0 0) systems. Oxygen and hydrogen interact differently with Ni(1 0 0) surface, nevertheless, both species do not affect to a great extent the vibrational properties of CO. A phase of CO molecules weakly bonded to the surface and unaffected by coadsorbed oxygen and hydrogen, is found. Coverage of 0.5 ML of predosed oxygen chemically passivates the Ni(1 0 0) surface and inhibits any CO adsorption at room temperature. CO sites are unambiguously determined for each predosed Ni(1 0 0) surface. 相似文献
95.
T. Caruso C. Lenardi T. Mazza A. Policicchio R.G. Agostino E. Colavita K.C. Prince P. Piseri P. Milani 《Surface science》2007,601(13):2688-2691
Nanostructured titanium dioxide (ns-TiO2) films were grown by supersonic cluster beam deposition method. Transmission electron microscopy demonstrated that films are mainly composed by TiO2 nanocrystals embedded in an amorphous TiO2 phase while their electronic structure was studied by photoemission spectroscopy. The cluster assembled ns-TiO2 films are expected to exhibit several structural and chemical defects owing to the large surface to volume ratio of the deposited clusters. Ultraviolet photoemission spectra (hv = 50 eV) from the valence band unveil the presence of a restrained amount of surface Ti 3d defect states in the band gap, whereas Ti 2p core level X-ray photoelectron (hv = 630 eV) spectra do not manifestly disclose these defects. 相似文献
96.
Dr. Stefano Tommasone Dr. Carmen Talotta Prof. Carmine Gaeta Luigi Margarucci Dr. Maria Chiara Monti Prof. Agostino Casapullo Dr. Beatrice Macchi Dr. Salvatore Pasquale Prete Dr. Adriana Ladeira De Araujo Prof. Placido Neri 《Angewandte Chemie (International ed. in English)》2015,54(51):15405-15409
MS‐based chemical‐proteomics technology is introduced herein as a third general strategy to study the biomolecular recognition properties of given calixarene derivatives. In particular, we demonstrate that a simply designed calix[4]arene derivative 1 a bearing acetamido groups at the exo rim (pAC), when linked to a solid support, is able to fish out a specific protein (PDI protein) from a crude extract of HeLa cells. Western blot and surface plasmon resonance studies confirmed the direct interaction between PDI and the linker‐free pAC derivative 1 b with considerable affinity, and in vitro tests showed its inhibition of PDI chaperone activity. In accordance with the role of PDI in a variety of human cancers, biological tests showed that pAC 1 b was cytotoxic and cytostatic toward CAL‐27 and PC‐3 cancer cell lines in vitro. Docking studies showed that H bonds and hydrophobic interactions contribute to the stabilization of the PDI/pAC complex. 相似文献
97.
G Giardina P D’Agostino G Fazio M Herman AI Muninov A Nasirov G Oliva R Palamara R Ruggeri 《Pramana》1999,53(3):409-418
The fusion-fission reaction mechanism leading to the massive nucleus formation is studied. We investigate the superheavy nucleus
formation in heavy-ion induced reactions by analysing the evaporation residue (ER) production in order to study the fusion
dynamics and the decay properties of nuclei close to the stability island at Z=114. We consider the 61Ni+208Pb, 48Ca+238U and 48Ca+244Pu reactions that lead to the Z=110, 112 and 114 superheavy elements respectively.
By using the dinuclear system (DNS) concept of the two interacting nuclei we calculate the quasifission-fusion competition
in the entrance channel and the fission-evaporation competition along the de-excitation cascade of the compound nucleus. The
dynamics of the entrance channel allows us to determine the beam energy window which is favorable to the fusion, while the
dynamic evolution of the compound nucleus on the shell correction to the fission barrier and the dissipative effects influence
the fission-evaporation competition in order to obtain the residue nuclei from the superheavy nucleus formation. We also calculate
the τ
n
/τtot ratio at each step of the de-excitation cascade of the compound nucleus and we present a systematics of τ
n
/τtot (at first step of the cascade) for many reactions that lead to nuclei with Z=102–114. 相似文献
98.
P. M. Milazzo G. Vannini M. Bruno N. Colonna M. D’Agostino F. Gramegna G. V. Margagliotti P. F. Mastinu A. Moroni 《The European Physical Journal A - Hadrons and Nuclei》2000,7(3):355-360
The dependence of the nuclear temperatures of highly excited systems, extracted by means of the double ratios of the emitted
isotopes, on the experimental conditions is investigated. Experimental data obtained in the Xe+Cu 30 MeV/nucleon reaction
are used to study the sensitivity of the method and the effects of the energy thresholds on the obtained temperature values.
We find that the temperatures extracted using the He/Li ratios can be strongly influenced by the experimental energy thresholds
which are different for different elements. These distortions depend on the velocity of the emitting system and on the detection
angle and therefore particular care is needed in the choice of the detectors in those experiments in which velocities are
low and angles are large. The use of four isotopes of the same element make negligible such effects.
Received: 6 October 1999 / Accepted: 28 May 2000 相似文献
99.
Dr. Joanna Lazniewska Dr. Mark Agostino Dr. Shane M. Hickey Dr. Emma Parkinson-Lawrence Dr. Stefano Stagni Dr. Massimiliano Massi Dr. Douglas A. Brooks Dr. Sally E. Plush 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(44):11406-11417
Re(I) complexes have potential in biomedical sciences as imaging agents, diagnostics and therapeutics. Thus, it is crucial to understand how Re(I) complexes interact with carrier proteins, like serum albumins. Here, two neutral Re(I) complexes were used (fac-[Re(CO)3(1,10-phenanthroline)L], in which L is either 4-cyanophenyltetrazolate (1) or 4-methoxycarbonylphenyltetrazole ester (2) , to study the interactions with bovine serum albumin (BSA). Spectroscopic measurements, calculations of thermodynamic and Förster resonance energy transfer parameters, as well as molecular modelling, were performed to study differential binding between BSA and complex 1 and 2 . Induced-fit docking combined with quantum-polarised ligand docking were employed in what is believed to be a first for a Re(I) complex as a ligand for BSA. Our findings provide a basis for other molecular interaction studies and suggest that subtle functional group alterations at the terminal region of the Re(I) complex have a significant impact on the ability of this class of compounds to interact with BSA. 相似文献
100.
Gatto MT Firuzi O Agostino R Grippa E Borsò A Spinelli F Pavan L Petrolati M Petrucci R Marrosu G Saso L 《Biomedical chromatography : BMC》2002,16(6):404-411
A new assay for the screening of hypochlorite/hypochlorous acid (XOCl) scavengers, based on the reversed-phase high performance liquid chromatographic analysis of human serum albumin (HSA, 0.2% in 100 mM sodium phosphate, pH 7), before and after oxidation by XOCl (1.6 mM), was developed. XOCl induced a significant decrease of the area under the chromatographic peak of HSA at 280 nm due to the oxidation of the aromatic amino acids tryptophan and tyrosine, as suggested by the literature and by the chromatographic analyses and the electrochemical study performed here. The assay was validated by testing known XOCl scavengers such as ascorbic acid, cysteine, glutathione, S-methylglutathione and alpha-lipoic acid and other antioxidants such as carnosine and chlorogenic acid, which inhibited the oxidation of HSA. Quantitative activities were calculated using an original formula based on the changes of the area of the albumin peak. Electrochemical data collected here in a homogeneous medium showed that the anodic potentials of the antioxidants tested are less positive (ascorbic acid, chlorogenic acid and cysteine) or similar (alpha-lipoic acid) compared with those of the aromatic residues (tryptophan and tyrosine) of HSA oxidized by XOCl. However, as expected, carnosine, glutathione and S-methylglutathione were inactive at a glassy-carbon, gold or platinum electrode. 相似文献