Polymer ligand binding to surface-immobilized gold nanoparticles: a fluorescence-based study on the adsorption kinetics.

We report on a simple, fluorescence-based method for the investigation of the binding kinetics of polystyrene ligands, dispersed in an organic solvent, to substrate supported gold nanoparticles. For this purpose, we develop a protocol for the immobilization of gold nanoparticles on glass substrates, that yields sub-monolayers of randomly distributed particles with excellent homogeneity and reproducibility. Using fluorescently labeled polystyrene, we monitor the ligand concentration in bulk dispersion in real time and follow the binding to the particle-decorated substrates.

Versatile Route toward Hydrophobically Polymer-Grafted Gold Nanoparticles from Aqueous Dispersions.

Stabilization of gold nanoparticles in organic solvents is a key challenge in making them available for a wider range of material applications. Polymers are often used as stabilizing ligands because they also allow for the introduction of new properties and functionalities. Many of the established synthesis protocols for gold nanoparticles are water-based.

From normal diffusion to superdiffusion: Photothermal heating of plasmonic core-shell microgels.

The motion of core-shell colloids during laser heating is studied using angle-dependent pump-probe dynamic light scattering. The cores consist of a single spherical gold nanoparticle whose localized surface plasmon resonance has a strong spectral overlap with the wavelength of the pump laser. They are homogeneously encapsulated in thick hydrogel shells composed of either chemically cross-linked poly-N-isopropylacrylamide or poly[2-(2-methoxyethoxy)ethyl methacrylate], both of which exhibit a temperature-dependent volume phase transition.

Silver Nanoparticle Gradient Arrays: Fluorescence Enhancement of Organic Dyes.

Noble metal nanoparticles show pronounced extinction peaks in the visible wavelength range due to their localized surface plasmon resonances. The excitation of these resonances leads to strong confinement of electromagnetic energy at nanometer scales, which is critical for ultrasensitive, fluorescence-based detection of analytes. The strength and spatial distribution of this near-field zone depend on particle size, shape, and composition.

Cost-control and medical specialist payment: the Dutch alternative.

The fee-for-service system is a growing problem for insurers and governments. The main reason for this is the open-ended character of this system which makes cost-control a very difficult task. The pressures on the fee-for-service system are becoming more pronounced, especially in countries such as Canada, Germany and the Netherlands which use budget restrictions on national health care expenditure (macro caps).

Long-term follow-up of two patients with metastatic neuroendocrine tumours treated with octreotide.

Two patients are described with metastatic neuroendocrine tumours of the pancreas head and region of Vater. After surgery, administration of the long-acting somatostatin analogue octreotide was started. In the first patient we found an IgG-lambda paraproteinaemia and a parathyroid hormone-related protein (PTHrP) driven hypercalcaemia.

Distribution of mesalazine enemas in active and quiescent ulcerative colitis.

Background: The efficacy of mesalazine enemas depends on intraluminal concentration of the drug and is therefore limited by the enema distribution in the colon. Active ulcerative colitis changes colon motility and this leads to uncertainty about enema spread.

Aim: To assess the influence of disease activity on enema distribution, we conducted a physician-blinded, longitudinal study of the retrograde spread of three mesalazine enemas.

Eosinophilic gastroenteritis--a disease with a wide clinical spectrum.

Two patients with eosinophilic gastroenteritis are described. The predominant eosinophilic infiltration of the mucosal layer of the upper gastrointestinal tract resulted in severe protein-losing enteropathy and peripheral eosinophilia in one patient and a malabsorption syndrome due to saccharose and lactose intolerance in another patient. There was a wide range of abdominal symptoms, depending on the site and extent of the disease.

Ultrastructural evidence for the presence of ferritin-iron in the biliary system of patients with iron overload.

Ferritin-like particles were observed in bile canaliculi of patients with iron overload. These particles have been further investigated by: a staining method enhancing the size and contrast of ferritin protein, and electron probe microanalysis detecting the presence of the elements iron and phosphorus. Morphological observation of coated vesicles in the cytoplasm adjacent to the bile canaliculi and coated pits in the canalicular membrane suggests a transport mechanism via membrane-bound organelles.

The amount of ferritin and hemosiderin in the livers of patients with iron-loading diseases.

Depot iron, ferritin iron, and ferritin protein were measured in 34 liver needle biopsy specimens obtained from patients with primary and secondary iron-loading diseases. The patients were classified as idiopathic hemochromatosis (14), porphyria cutanea tarda (4), and iron-loading anemias (16). With accumulation of depot iron, the amount of liver ferritin protein increased, however, the ratio of ferritin protein to depot iron fell at concentrations of depot iron in excess of 1,000 micrograms per gm of liver.