Search results for "Light scatter"

Biogenic iron-silver nanoparticles inhibit bacterial biofilm formation due to Ag+ release as determined by a novel phycoerythrin-based assay

2020

Silver nanoparticles (Ag-NPs) can be considered as a cost-effective alternative to antibiotics. In the presence of Fe(III)-citrate and Ag+, Klebsiella oxytoca DSM 29614 produces biogenic Ag-NPs embedded in its peculiar exopolysaccharide (EPS). K. oxytoca DSM 29614 was cultivated in a defined growth medium–containing citrate (as sole carbon source) and supplemented with Ag+ and either low or high Fe(III) concentration. As inferred from elemental analysis, transmission and scanning electron microscopy, Fourier transform infrared spectrometry and dynamic light scattering, Ag-EPS NPs were produced in both conditions and contained also Fe. The production yield of high-Fe/Ag-EPS NPs was 12 times …

Orthogonal functionalisation of upconverting NaYF4 nanocrystals.

2013

A simple and straightforward method for the orthogonal functionalisation of upconverting NaYF4 nanocrystals (UCNCs)-doped withYb(3+) and Er(3+)-based on N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide/N-hydroxysuccinimide (EDC/NHS) selective reactions between two dyes and two different reactive groups present at the periphery of the upconverting nanocrystals is reported. Organic-soluble UCNCs of 10 and 50 nm in size are encapsulated efficiently in a 1:1 mixture of two commercial 3000 Da poly(ethylene glycol) derivatives with two different reactive groups (amino and carboxylic groups). The water-dispersible UCNCs are non-cytotoxic, stable in the physiological environment, and present free ami…

Solid lipid nanoparticles from amphiphilic calixpyrroles

2016

Abstract Hypothesis Macrocyclic amphiphiles form interesting self-assembling structures, including solid lipid nanoparticles, which have potential applications in drug encapsulation. Aryl-extended calixpyrroles, which act as anion binding hosts, are expected to form solid lipid nanoparticles, even though the alkyl chains have unusual perpendicular geometry with respect to the hydrophilic head group. The preparation conditions and the alkyl chain length should affect the size and stability of the particles. Experiments Solid lipid nanoparticles of two aryl-extended calixpyrroles with resorcinol walls and either meso-dodecyl or meso-methyl alkyl chains were compared. Ethanolic solutions of th…

Single Out-of-Resonance Dielectric Nanoparticles as Molecular Sensors.

2021

Light scattering from single nanoparticles and nanostructures is a commonly used readout method for nanosensors. Increasing the spectral sensitivity of resonant nanosensors to changes in their local surrounding has been the focus of many studies. Switching from spectral to intensity monitoring allows one to investigate nonresonant or out-of-resonance dielectric nanoparticles. Here, we systematically compared such dielectric silica nanoparticles with plasmonic gold nanorods by deriving analytical expressions and by performing experiments. The experiments show a similar sensitivity for the detection of an adsorbate layer for both particle types, which is in good agreement with theory. The fla…

Time response of the vision binocularity by use of dynamic suppression of retinal images

1999

We present a novel technique for determination the stereopsis dynamic response, using as stimulus a random dot stereopair. Stereopsis can be evoked or depressed by continuous or flash illumination of the stimulus with simultaneous control of a special light scattering obstacle build in the visual path of one eye. The obstacle--a thin plate of electrooptical PLZT ceramics-- exposes (by applying of the voltage to semitransparent gold electrodes deposited on both surfaces of the plate) light scattering so blurring the retinal image, similar as for an eye with a cataract, depressing stereopsis. The random dot stereopair contains contours of images with a different stereodisparity. The PLZT plat…

Measurements of the 90,91,92,94,96 Zr n, gamma cross-sections at n_TOF

2005

Neutron capture cross sections of the 90,91,92,94,96Zr have been measured over the energy range from 1 eV to 1 MeV at the spallation neutron facility n TOF at CERN in 2003. The innovative features of the neutron beam, in particular the high instantaneous flux, the high energy resolution and low background, together with improvements of the neutron sensitivity of the capture detectors make this facility unique for neutron-induced reaction cross section measurements with much improved accuracy. The preliminary results of the Zr measurements show capture resonance strengths generally smaller than in previous measurements. Peer Reviewed

A neutron spectrometer for studying giant resonances with (p, n) reactions in inverse kinematics

2014

A neutron spectrometer, the European Low-Energy Neutron Spectrometer (ELENS), has been constructed to study exotic nuclei in inverse-kinematics experiments. The spectrometer, which consists of plastic scintillator bars, can be operated in the neutron energy range of 100 keV to 10 MeV. The neutron energy is determined using the time-of-flight technique, while the position of the neutron detection is deduced from the time-difference information from photomultipliers attached to both ends of each bar. A novel wrapping method has been developed for the plastic scintillators. The array has a larger than 25% detection efficiency for neutrons of approximately 500 keV in kinetic energy and an angul…

Nucleation kinetics in deionized charged colloidal suspension

2011

A systematic experimental study on the nucleation, crystallization and crystal-growth of one-componentcharged colloidal particles (122 nm diluted in pure water with densities between 0.5 μm−3bnpb5 ...

Nucleation mechanism of Lysozyme at physiological pH

2010

Stability of parenteral nutrition admixtures containing organic phosphates

1995

The use of organic phosphates to avoid calcium phosphate precipitation in parenteral nutrition mixtures has been proposed. The purpose of this study was to evaluate the stability of total parenteral nutrition admixtures containing glucose-1-phosphate or glycerol phosphate as the phosphate source over 3 days. Three parenteral nutrition admixtures, each containing glucose-1-phosphate (30.0 mmol), glycerol phosphate (31.4 mmol) or inorganic phosphate (30.0 mmol), and their corresponding aqueous phases were prepared in 3-L ethylene vinyl acetate plastic bags and infusion bottles, and stored at 5 +/- 1 degrees C or 22 +/- 3 degrees C without light protection. Physical stability analysis and samp…