Absorption spectroscopy of complex rare earth ion doped hybrid materials over a broad wavelength range

In the present work we applied a measurement setup to determine several relevant properties of rare-earth doped nanoparticles dispersed in polymer slab waveguides in a single absorption measurement: background absorption of the polymer host material, water absorption, polymer composition (overtones), rare earth concentration, and ligand contribution (increase of exponential loss trend in the UV). Furthermore, nanoparticle size and concentration in case of a refractive index mismatch (1//spl lambda//sup 4/ and r/sup 6/ dependence of Rayleigh scattering losses in the UV) could be extracted

Optical gain of LaF3:Nd nanoparticle doped polymers for active integrated optical devices.

We report on rare earth doped LaF3 nanoparticles dispersed in PMMA and SU-8 photosensitive polymers. We observed optical gain after we applied these materials for waveguides. Experimental results on various samples will be discussed. We theoretically discuss the improvements that can be obtained and the possibilities of this new class of materials when applied to microring resonators

Risk and outcome in colorectal cancer surgery

Surgery always concerns the balance of risk and benefit. Both risk and benefit can vary immensely among patients. Outcome and prognosis are determined by several patient, tumour and treatment characteristics. In order to achieve the best possible outcomes for colorectal cancer patients, detailed and objective information on risk profiles is indispensible. For the individual patient it should guide clinical judgment and the administration of tailored care. On a hospital or population level knowledge of risk factors can lead to adjusted (better tailored) treatment protocols and better information on case mix influences adding to an improved care for colorectal cancer patients.UBL - phd migration 201

A novel photodefinable polymer containing rare-earth doped nanoparticles for optical amplification

We report on neodymium doped LaF3 nanoparticles dispersed in a photo definable polymer. Standard spin coating is used to deposit uniform thin films on a silicondioxide buffer layer, which can be photocured and developed to produce monomode active optical waveguides. Optical properties of the film are obtained using a prism coupling setup, showing low losses of the photosensitive polymer host material in both the visible and infrared. In addition, the absorption and emission due to the neodymium doped LaF3 nanoparticles have been determined for a range of particle concentrations

Indicator voor stikstofmineralisatie op gescheurd grasland = Indicator of nitrogen mineralisation on broken meadowland

This report addresses the results of an experiment with field trials with potatoes and silage maize onsandy soil in 2006 in order to obtain a suitable indicator for predicting N-mineralisation after ploughing the grassland. This study is part of a larger project with more field trials and a laboratory experiment. Ploughed grassland on the locations selected provided much nitrogen, due to which it was not possible to infer an indicator from the crop response for adjusting nitrogen recommendation. N-total seems to be the most promising parameter in predicting nitrogen mineralisatio

Clinical relevance of gallbladder polyps; is cholecystectomy always necessary?

Background: Gallbladder polyps are common incidental findings during abdominal ultrasonography. Cholecystectomy is recommended for polyps equal or greater than 10 mm on ultrasound due to their malignant potential. However, the majority of lesions appear to be pseudopolyps with no malignant potential. Our aim was to determine the correlation between ultrasonographic findings and histopathological findings after cholecystectomy for gallbladder polyps in two institutions. Method: A retrospective analysis was performed at two Dutch institutions of patients who underwent cholecystectomy. All cholecystectomies for suspected gallbladder polyps between January 2010 and August 2017 were included. Ultrasonographic and hist

Luttinger Parameter g for Metallic Carbon Nanotubes and Related Systems

The random phase approximation (RPA) theory is used to derive the Luttinger parameter g for metallic carbon nanotubes. The results are consistent with the Tomonaga-Luttinger models. All metallic carbon nanotubes, regardless if they are armchair tubes, zigzag tubes, or chiral tubes, should have the same Luttinger parameter g. However, a (10,10) carbon peapod should have a smaller g value than a (10,10) carbon nanotube. Changing the Fermi level by applying a gate voltage has only a second order effect on the g value. RPA theory is a valid approach to calculate plasmon energy in carbon nanotube systems, regardless if the ground state is a Luttinger liquid or Fermi liquid. (This paper was published in PRB 66, 193405 (2002). However, Eqs. (6), (9), and (19) were misprinted there.)Comment: 2 figure