Search results for "Colloid"

Novel yeast extract is superior to colloidal oatmeal in providing rapid itch relief

2020

Background Approximately, 13.5% of the population suffers from chronic itch. Many cosmetic and pharmaceutical treatments for itch are available; however, cosmetic treatments are not reliably effective and most pharmaceutical formulations carry the risk of adverse events with chronic use. Aims Previously, we have reported a novel extraction process of Saccharomyces cerevisiae, that is, Baker's yeast. The extract obtained from the novel process demonstrates superior anti-itch properties compared to other yeast extracts. In our previous study, we demonstrated that, after 30 minutes, the extract significantly reduced itch when compared to a placebo lotion (P = .002). Methods In the present stud…

Influence of drug polarity upon the solid-state structure and release properties of self-emulsifying drug delivery systems in relation with water aff…

2009

To overcome low oral bioavailability of poorly water-soluble drugs, self-emulsifying drug delivery systems (SEDDS) have been noted as a promising strategy. However, incorporation of drugs into SEDDS composed of Gelucire44/14 could induce interactions not yet well understood. The aim of this study was to investigate the influence of drug polarity upon the solid-state structure of SEDDS formulation, particularly in terms of wettability, thermal behaviour and microscopic aspects and their effect upon the release properties of the SEDDS. Model drugs were naproxen and sodium naproxen (10% w/w), two drugs with similar chemical structure but different water solubilities. Both drugs had an effect o…

Solid lipid nanoparticles containing tamoxifen characterization and in vitro antitumoral activity.

2005

Solid lipid nanoparticles (SLNs) containing tamoxifen, a nons- teroidal antiestrogen used in breast cancer therapy, were prepared by microemulsion and precipitation techniques. Tamoxifen loaded SLNs seem to have dimensional properties useful for parenteral administration, and in vitro plasmatic drug release studies demon- strated that these systems are able to give a prolonged release of the drug in the intact form. Preliminary study of antiproliferative ac- tivity in vitro, carried out on MCF-7 cell line (human breast cancer cells), demonstrated that SLNs, containing tamoxifen showed an antitumoral activity comparable to free drug. The results of char- acterization studies and of in vitro …

Fluoride Complexation of Element 104, Rutherfordium

2004

Fluoride complexation of element 104, rutherfordium (Rf), produced in the 248Cm(18O,5n)261Rf reaction has been studied by anion-exchange chromatography on an atom-at-a-time scale. The anion-exchange chromatographic behavior of Rf was investigated in 1.9-13.9 M hydrofluoric acid together with those of the group-4 elements Zr and Hf produced in the 18O-induced reactions on Ge and Gd targets, respectively. It was found that the adsorption behavior of Rf on anion-exchange resin is quite different from those of Zr and Hf, suggesting the influence of relativistic effects on the fluoride complexation of Rf.

First Ionization Potentials of Fm, Md, No, and Lr

2018

We report the first ionization potentials (IP1) of the heavy actinides, fermium (Fm, atomic number Z = 100), mendelevium (Md, Z = 101), nobelium (No, Z = 102), and lawrencium (Lr, Z = 103), determined using a method based on a surface ionization process coupled to an online mass separation technique in an atom-at-a-time regime. The measured IP1 values agree well with those predicted by state-of-the-art relativistic calculations performed alongside the present measurements. Similar to the well-established behavior for the lanthanides, the IP1 values of the heavy actinides up to No increase with filling up the 5f orbital, while that of Lr is the lowest among the actinides. These results clear…

Redox-Tunable Defects in Colloidal Photonic Crystals

2005

Interaction of ionic compounds with multilamellar liposomes. An electrokinetic model

1998

Abstract We have proposed a theoretical model of interaction of ionic compounds (ionic adsorbate or ionic drugs), with multilamellar-liposomes, by means of their electrokinetic property variation with the ionic compound concentration. In this work, we show the complete development of the model proposed. Its theoretical results have been analysed to study the influence on the zeta-potential value of the following: number of membranes, size, shear-plane situation, critical concentration of formation (ccf), and the ionic compound concentration which annuls the zeta-potential value of the multilamellar-liposomes formed.

Partial Reduction and Selective Transfer of Hydrogen Chloride on Catalytic Gold Nanoparticles

2017

© 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim HCl in solution accepts electron density from Au NPs and partially reduces at room temperature, as occurs with other simple diatomic molecules, such as O2 and H2. The activation can be run catalytically in the presence of alkynes to give exclusively E-vinyl chlorides, after the regio- and stereoselective transfer of HCl. Based also on this method, vinyl chloride monomer (VCM) can be produced in a milder and greener way than current industrial processes.

Structural and vibrational study of the tautomerism of histamine free-base in solution.

2003

Infrared and Raman spectroscopy in H(2)O and D(2)O and quantum Density Functional calculations were used to determine the structure of histamine free-base in aqueous solution. A quantum mechanical study of the tautomeric equilibrium of histamine free-base in solution was performed at the 6-311G level. Electronic correlation energies were included by using the hybrid functional B3LYP. The solvent was simulated as a continuum characterized by a dielectric constant, and the quantum system (solute) was placed in an ellipsoidal cavity. Solute-solvent electrostatic interaction was calculated by means a multipolar moment expansion introduced in the Hamiltonian. Four relevant histamine conformation…

Electrophoresis of model colloidal spheres in low salt aqueous suspension

2004

We report on comprehensive measurements of the electrophoretic mobility μ of a highly charged spherical colloid in deionized or low salt aqueous suspensions, where fluid and crystalline order develops with increased packing fraction Φ. We propose the existence of a 'universal' shape of the μ(Φ) showing three distinct regimes: a logarithmic increase, a plateau and a logarithmic decrease. The position and the height of the plateau are found to be influenced by the particle surface properties and the electrolyte concentration. In particular, it starts once the counter-ion concentration becomes equal to the concentration of background electrolyte. This coincides only loosely with the range of Φ…