Electronic Properties of Small Particles

Kubo, Ryōgo; Kawabata, Arisato; Kobayashi, Shun–ichi

doi:10.1146/annurev.ms.14.080184.000405

Cited by 193 publications

(113 citation statements)

References 1 publication

Supporting

Mentioning

107

Contrasting

Order By: Relevance

“…We also found that ERW contains a small amount of platinum (Pt) nanoparticles (Pt nps) (Shirahata 2004). In general, metal nanoparticles of less than 2 nm exhibit strong catalysis activity because of their high surface reactivity (Kubo et al 1984). Synthesized Pt nps of 2 nm or less can disperse in aqueous solutions for a long time and convert hydrogen molecules to active hydrogen (atomic hydrogen) on the surface.…”

Section: Introductionmentioning

confidence: 99%

Electrolyzed Reduced Water Supplemented with Platinum Nanoparticles Suppresses Promotion of Two-stage Cell Transformation

et al. 2005

View full text Add to dashboard Cite

In the two-stage cell transformation theory, cancer cells first receive initiation, which is mainly caused by DNA damage, and then promotion, which enhances transformation. Murine Balb/c 3T3 cells are widely used for transformation experiments because they lose contact inhibition ability when transformed. Electrolyzed reduced water (ERW), which is produced near a cathode during electrolysis of water, is an alkaline drinking water that is beneficial to health. ERW contains a high concentration of dissolved hydrogen and scavenge reactive oxygen species (ROS), along with a small amount of platinum (Pt) nanoparticles (Pt nps) derived from Pt-coated titanium electrodes. Pt nps stably disperse in aqueous solution for a long time, and convert hydrogen molecules to active hydrogen (atomic hydrogen) that can scavenge ROS. Therefore, ERW supplemented with synthesized Pt nps is a model strong reduced water. This is the first report that ERW supplemented with synthesized Pt nps strongly prevents transformation of Balb/c 3T3 cells. ERW was prepared by electrolysis of 0.002 M NaOH solution using a batch-type electrolysis device. Balb/c 3T3 cells were treated with 3-methyl cholanthrene (MCA) as an initiation substance, followed by treatment with phorbol-12-myristate-13-acetate (PMA) as a promotion substance. MCA/PMA-induced formation of a transformation focus was strongly suppressed by ERW supplemented with Pt nps but not by ERW or Pt nps individually. ERW supplemented with Pt nps suppressed transformation at the promoter stage, not at initiation, suggesting that ERW supplemented with Pt nps suppressed the PMA-induced augmentation of intracellular ROS. ERW supplemented with Pt nps is a potential new antioxidant against carcinogenesis.Abbreviations: ASA-2P -ascorbic acid 2-phosphate; ERW -electrolyzed reduced water; FBS -fetal bovine serum; HEPES -2-[4-(2-hydroxyethyl)-1-piperazinyl]ethanesulfonic acid; MCA -3-methyl cholanthrene; MEM -minimum essential medium; PMA -phorbol-12-myristate-13-acetate; Pt nanoparticles -Pt nps; ROS -reactive oxygen species Cytotechnology (2005)

show abstract

Section: Introductionmentioning

confidence: 99%

Electrolyzed Reduced Water Supplemented with Platinum Nanoparticles Suppresses Promotion of Two-stage Cell Transformation

et al. 2005

View full text Add to dashboard Cite

show abstract

“…According to Kubo's criterion [13] a cluster that has metallic character when the average level spacing becomes smaller than the thermal energy k B T and the discrete energy levels begins to form a quasi-continuous band, or formulated in terms of the density of states (DOS) D(E), when…”

Section: Methodsmentioning

confidence: 99%

“…How about the nonmetal to metal transition in Ba cluster? Second, it has been found that the magic numbers in Ba clusters are 13,19,23,26,29, and 32 [12]; which magic cluster is in the metallic state in the room temperature?…”

Section: Introductionmentioning

confidence: 99%

Nonmetal–metal transition in Ban clusters

Wang

Sun

2001

Solid State Communications

View full text Add to dashboard Cite

Understanding the development of metallic behavior with increasing cluster size has been one of the important questions in cluster science. Based on Kubo's criterion and optimized structures with ab initio calculations, the nonmetal to metal transition in Ba clusters is studied. It has been found that the critical size for this transition is around 32, in agreement with the mass spectra experiment. q

show abstract

“…This calls for a statistical analysis of the level spectrum [27,28]. In the atomic clusters the distribution of the single particle levels in the immediate vicinity of the Fermi level is important in determining the thermodynamical properties.…”

Section: Surface Roughnessmentioning

confidence: 99%

Effects of the cluster surface on the electronic shell structure: faceting, roughness and softness

Mansikka-aho

Manninen

Hammarén

1994

Z Phys D - Atoms, Molecules and Clusters

View full text Add to dashboard Cite

Abstract. Several simple models have been used to study the effects of the surface on the electronic shell structure in metal clusters. The main results are as follows: The icosahedral clusters have the same electronic shell structure as the sphere up to about 1000 atoms. The surface roughness causes the distribution of the level spacings to be a Wigner distribution. By varying the softness of the potential we can obtain potentials where the simplest classical orbits are the 'five-point star' or even the 'threepoint star'.

show abstract

Electronic Properties of Small Particles

Cited by 193 publications

References 1 publication

Electrolyzed Reduced Water Supplemented with Platinum Nanoparticles Suppresses Promotion of Two-stage Cell Transformation

Electrolyzed Reduced Water Supplemented with Platinum Nanoparticles Suppresses Promotion of Two-stage Cell Transformation

Nonmetal–metal transition in Ban clusters

Effects of the cluster surface on the electronic shell structure: faceting, roughness and softness

Contact Info

Product

Resources

About