Search results for " Gold"

Physicochemical investigation of surfactant-coated gold nanoparticles synthesized in the confined space of dry reversed micelles

2006

Abstract Gold nanoparticle/surfactant composites have been synthesized by a novel reduction reaction in the confined space of dry sodium bis(2- ethylhexyl)sulfosuccinate (AOT) or lecithin reversed micelles dispersed in n-heptane and cyclohexane, respectively. The reaction was carried out by adding an opportune amount of anhydrous hydrazine/tetrahydrofuran solution to a suspension of HAuCl4-containing dry reversed micelles dispersed in organic solvent. UV–vis investigation ascertained the formation of stable metal gold nanoparticles and the analysis of FT-IR spectra highlighted the formation of an oriented surfactant monolayer at the nanoparticle surface. Simple evaporation under vacuum of t…

Excitation Energy-Transfer in the LH2 Antenna of Photosynthetic Purple Bacteria via Excitonic B800 and B850 States

2000

A newly developed CIEM method that uses a combination of semi-empirical or ab-initio configuration interaction methods and exciton theory to predict electronic energies, eigenstates, absorption and CD spectra of aggregated chromophoric systems with environmental interactions included is extended and used for estimation of excitation energy transfer rates. Excitonic energy levels of the two ring systems the B800 and the B850 of the light harvesting antenna LH2 of Rhodopseudomonas acidophila and the corresponding absorption spectrum were calculated by assuming inter-ring interactions to be zero. Excitation energy transfer rates were calculated by using the Fermi Golden rule with the dipole - …

Emotions and Technoethics

2020

The relationship between emotions and ethics has been debated for centuries. The act of understanding emotions through the framework of ethics involves accepting that emotions are to some extent culturally dependent. By linking emotions in design to larger ethical discussions, it may be accepted that ethics and design are both technological constructions designed to shape a collective worldview. While both are cultural constructions, they are in constant dialogue with one another through social discourse and individualistic cognitive–affective appraisal processes. This chapter presents an account of technoethics that challenges ideas of ethical values embedded within technology, drawing att…

Biodegradable Ultrasmall-in-Nano Gold Architectures: Mid-Period In Vivo Distribution and Excretion Assessment

2018

Polyphenols Epigallocatechin Gallate and Resveratrol, and Polyphenol-Functionalized Nanoparticles Prevent Enterovirus Infection through Clustering an…

2021

To efficiently lower virus infectivity and combat virus epidemics or pandemics, it is important to discover broadly acting antivirals. Here, we investigated two naturally occurring polyphenols, Epigallocatechin gallate (EGCG) and Resveratrol (RES), and polyphenol-functionalized nanoparticles for their antiviral efficacy. Concentrations in the low micromolar range permanently inhibited the infectivity of high doses of enteroviruses (107 PFU/mL). Sucrose gradient separation of radiolabeled viruses, dynamic light scattering, transmission electron microscopic imaging and an in-house developed real-time fluorescence assay revealed that polyphenols prevented infection mainly through clustering of…

Työkalu psyykkisten taitojen harjoitteluohjelmien optimoimiseen

2022

Contre la fausse objectivité, le perspectivisme assumé ? le reportage « gonzo » de Goldin, Clark, D’Agata, Tillmans contre la photographie « document…

2019

International audience; Après 1945, un certain nombre de praticiens de la « photographie plasticienne »privilégièrent le reportage « communautaire » : une plongée, sur le long terme, au sein d’ungroupe d’individus, souvent connus, voire intimes, du photographe, qui loin de se placercomme un témoin neutre, activait le mécanisme de l’observation participante chère àl’ethnographie. Larry Clark en fournit un exemple avec la série Tulsa (1971), la premièred’une longue lignée. Nan Goldin amplifia d’autant l’inclusion de l’autrice par la pratique del’autoportrait en situation dans The Ballad of Sexual Dependency (1981-1996). Plus tard desartistes comme Antoine d’Agata ou Wolfgang Tillmans poursuiv…

Representations of the Life-giving Spring feast in Romanian iconography

2021

This article explores the development of the theme of the Life-giving Spring in Byzantine iconography. The path towards its establishment was initiated at the moment when a representation rule, an original convention was set. Thereafter, because of its diffusion in time and space, the theme became enriched by particular mentalities and sensibilities of the epochs and the communities that adopted it as a form of devotion for the Virgin Theotokos. As a result, the representations we have known so far are extremely varied. Contribution: The final purpose of this approach, as well as its contribution, is to highlight the diverse unity of the iconographic tradition and illustrate both the evolut…