309 results match your criteria: "Lund Institute of Technology[Affiliation]"

PIXE-electrophoresis shows starving collembolan reallocates protein-bound metals.

Ecotoxicology

January 2016

Animal Physiological Ecology, Institute of Evolution and Ecology, University of Tübingen, Auf der Morgenstelle 5, 72076, Tübingen, Germany.

One of multiple functions of metalloproteins is to provide detoxification to excess metal levels in organisms. Here we address the induction and persistence of a range of low to high molecular weight copper- and zinc binding proteins in the collembolan species Tetrodontophora bielanensis exposed to copper- and zinc-enriched food, followed by a period of recovery from metal exposure, in absence and presence of food. After 10 days of feeding copper and zinc contaminated yeast, specimens were either moved to ample of leaf litter material from their woodland stand of origin or starved (no food offered).

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A two-dimensional model for stress driven diffusion in bone tissue.

Comput Methods Biomech Biomed Engin

December 2015

a Division of Solid Mechanics, Lund Institute of Technology, Lund University, SE-221 00 Lund , Sweden.

The growth and resorption of bone are governed by interaction between several cells such as bone-forming osteoblasts, osteocytes, lining cells and bone-resorbing osteoclasts. The cells considered in this study reside in the periosteum. Furthermore, they are believed to be activated by certain substances to initiate bone growth.

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Engineering processes in meat products and how they influence their biophysical properties.

Meat Sci

December 2013

Department of Food Technology, Engineering and Nutrition, Lund Institute of Technology, Lund, Sweden.

Food engineering aspects of cooking of meat products in relation to their biophysical properties, such as water- and fat-holding, have been reviewed. Moreover, some of the new emerging, mild cooking technologies, such as high pressure and electro-based heating (radio frequency cooking and ohmic heating) have been discussed in relation to the biophysical properties of the meat products treated. The holding of the bulk water (about 70% of the muscle weight) was discussed, arguing capillary forces to be one of the dominating mechanisms for this holding, whereas the losses of water and fat (the flow) within the meat are governed by Darcy's law.

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Volume flow calculations on gas leaks imaged with infrared gas-correlation.

Opt Express

August 2012

Department of Physics, Lund Institute of Technology, P.O. Box 18, SE-221 00 Lund, Sweden.

Two methods for volume flow calculation from images of methane leakages to the atmosphere are presented. The images contain calibrated gas concentration × path length pixel information, and are processed with a block matching method and a theoretical velocity field method. Results from known methane flow in two laboratory setups and one unknown real leakage from a gas processing plant are compared with the image processing methods.

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Quantitative 3D imaging of scattering media using structured illumination and computed tomography.

Opt Express

June 2012

Division of Combustion Physics, Lund Institute of Technology, Box 118, S-221 00 Lund University, Sweden.

An imaging technique capable of measuring the extinction coefficient in 3D is presented and demonstrated on various scattering media. The approach is able to suppress unwanted effects due to both multiple scattering and light extinction, which, in turbid situations, seriously hampers the performance of conventional imaging techniques. The main concept consists in illuminating the sample of interest with a light source that is spatially modulated in both the vertical and horizontal direction and to measure, using Structured Illumination, the correct transmission in 2D at several viewing angles.

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A measurement technique capable of recording three-dimensional laser induced images with a spatial resolution of 610x512x20 voxels over a volume of 29x24x15 mm(3) and at a frame rate of 1 kHz is presented. A novel approach for sweeping the illuminating laser sheet across the investigated volume is introduced as a key feature. The technique is applied to imaging nebulized water droplets with a nitrogen-jet central feature.

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The accuracy, precision and limitations of the imaging technique named Structured Laser Illumination Planar Imaging (SLIPI) have been investigated. SLIPI, which allows multiply scattered light to be diminished, has previously demonstrated improvements in image quality and contrast for spray imaging. In the current study the method is applied to a controlled confined environment consisting of a mixture of water and monodisperse polystyrene microspheres.

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Epidemiological and animal studies have shown that dietary fiber is protective against the development of colon cancer. Dietary fiber is a rich source of the hydroxycinnamic acids ferulic acid (FA) and p-coumaric acid (p-CA), which both may contribute to the protective effect. We have investigated the effects of FA and p-CA treatment on global gene expression in Caco-2 colon cancer cells.

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Extended staphylococcal enterotoxin D expression in ham products.

Food Microbiol

May 2011

Applied Microbiology, Lund Institute of Technology, Lund University, P.O. Box 124, SE-221 00 Lund, Sweden.

Staphylococcal enterotoxin D (SED) is one of the most frequently recovered enterotoxins in staphylococcal food poisoning (SFP) outbreaks. The expression and production of SED were investigated in three ham products, i.e.

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The aim of this study is to investigate the feasibility of using three-directional velocity encoded 3D gradient echo (GE) phase contrast (PC) imaging to assess cerebrospinal fluid (CSF) flow connectivity in the human brain. Five healthy volunteers were scanned using low velocity sensitivity (V(enc) = 0.04-0.

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We present an interferometric pump-probe technique for the characterization of attosecond electron wave packets (WPs) that uses a free WP as a reference to measure a bound WP. We demonstrate our method by exciting helium atoms using an attosecond pulse (AP) with a bandwidth centered near the ionization threshold, thus creating both a bound and a free WP simultaneously. After a variable delay, the bound WP is ionized by a few-cycle infrared laser precisely synchronized to the original AP.

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Decay of polarons and molecules in a strongly polarized Fermi gas.

Phys Rev Lett

July 2010

Mathematical Physics, Lund Institute of Technology, P.O. Box 118, SE-22100 Lund, Sweden.

The ground state of an impurity immersed in a Fermi sea changes from a polaron to a molecule as the interaction strength is increased. We show here that the coupling between these two states is strongly suppressed due to a combination of phase-space effects and Fermi statistics, and that it vanishes much faster than the energy difference between the two states, thereby confirming the first order nature of the polaron-molecule transition. In the regime where each state is metastable, we find quasiparticle lifetimes which are much longer than what is expected for a usual Fermi liquid.

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Flotation as a tool for indirect DNA extraction from soil.

Appl Microbiol Biotechnol

August 2010

Applied Microbiology, Lund Institute of Technology, Lund University, PO Box 124, 221 00 Lund, Sweden.

Nowadays, soil diversity is accessed at molecular level by the total DNA extraction of a given habitat. However, high DNA yields and purity are difficult to achieve due to the co-extraction of enzyme-inhibitory substances that inhibit downstream applications, such as PCR, restriction enzyme digestion, and DNA ligation. Therefore, there is a need for further development of sample preparation methods that efficiently can result in pure DNA with satisfactory yield.

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Background: The effects of acetic acid, a common food preservative, on the bacteriophage-encoded enterotoxin A (SEA) expression and production in Staphylococcus aureus was investigated in pH-controlled batch cultures carried out at pH 7.0, 6.5, 6.

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Wall shear stress variations in a 90-degree bifurcation in 3D pulsating flows.

Med Eng Phys

March 2010

Department of Energy Sciences, Lund Institute of Technology, P.O. Box 118, SE-221 00 Lund, Sweden.

The exact role of fluid mechanics in the patho-physiological process of atherosclerosis has been a research topic over many years, yet without clear conclusive result. One has observed that morphological manifestations of the disease are found at some well-defined locations: certain vessel bifurcations and in curvatures. The flow in these regions is characterized by unsteadiness and often separation.

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Increased recirculation of process water has given rise to problems with formation of calcium oxalate incrusts (scaling) in the pulp and paper industry and in forest biorefineries. The potential in using oxalate decarboxylase from Aspergillus niger for oxalic acid removal in industrial bleaching plant filtrates containing oxalic acid was examined and compared with barley oxalate oxidase. Ten different filtrates from chemical pulping were selected for the evaluation.

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In Part I of this study [1], good agreement between experimental measurements and results from Monte Carlo simulations were obtained for the spatial intensity distribution of a laser beam propagating within a turbid environment. In this second part, the validated Monte Carlo model is used to investigate spatial and temporal effects from distinct scattering orders on image formation. The contribution of ballistic photons and the first twelve scattering orders are analyzed individually by filtering the appropriate data from simulation results.

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Speciation and distribution of arsenic and localization of nutrients in rice grains.

New Phytol

November 2009

Institute of Biological and Environmental Sciences, University of Aberdeen, Cruickshank Boulevard, St Machar Drive, Aberdeen, AB24 3UU, UK.

Arsenic (As) contamination of rice grains and the generally low concentration of micronutrients in rice have been recognized as a major concern for human health. Here, we investigated the speciation and localization of As and the distribution of (micro)nutrients in rice grains because these are key factors controlling bioavailability of nutrients and contaminants. Bulk total and speciation analyses using high-pressure liquid chromatography (HPLC)-inductively coupled plasma mass spectrometry (ICP-MS) and X-ray absorption near-edge spectroscopy (XANES) was complemented by spatially resolved microspectroscopic techniques (micro-XANES, micro-X-ray fluorescence (micro-XRF) and particle induced X-ray emission (PIXE)) to investigate both speciation and distribution of As and localization of nutrients in situ.

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Structure and function of a novel type of ATP-dependent Clp protease.

J Biol Chem

May 2009

Department of Plant and Environmental Sciences, University of Gothenburg, Box 461, S-405 30 Göteborg, Sweden. Electronic address:

The Clp protease is conserved among eubacteria and most eukaryotes, and uses ATP to drive protein substrate unfolding and translocation into a chamber of sequestered proteolytic active sites. The main constitutive Clp protease in photosynthetic organisms has evolved into a functionally essential and structurally intricate enzyme. The model Clp protease from the cyanobacterium Synechococcus consists of the HSP100 molecular chaperone ClpC and a mixed proteolytic core comprised of two distinct subunits, ClpP3 and ClpR.

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Improved performance in silicon enzyme microreactors obtained by homogeneous porous silicon carrier matrix.

Talanta

February 2002

Department of Electrical Measurements, Lund Institute of Technology, University of Lund, P.O. Box 118, 22100 Lund, Sweden.

The catalytic performance of porous silicon (PS) micro enzyme reactors (muIMER) is strongly dependent on the PS matrix morphology for enzyme immobilisation. PS was achieved in the muIMER by anodisation in a HF-ethanol mixture. PS etching of structured silicon surfaces commonly results in an inhomogeneous pore formation.

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A novel approach to reduce the multiple light scattering contribution in planar laser images of atomizing sprays is reported. This new technique, named Structured Laser Illumination Planar Imaging (SLIPI), has been demonstrated in the dense region of a hollow-cone water spray generated in ambient air at 50 bars injection pressure. The idea is based on using an incident laser sheet which is spatially modulated along the vertical direction.

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Advanced oxidation of refractory organics in leachate--potential methods and evaluation of biodegradability of the remaining substrate.

Environ Technol

September 2008

Water and Environmental Engineering at Department of Chemical Engineering, Lund Institute of Technology, P.O. Box 124, SE-221 00 Lund, Sweden.

An assessment of potential methods suitable for degradation and/or reduction of refractory organics was performed on landfill leachate from SYSAV AB, Malmö, Sweden. Pretreatment of the leachate was performed in a sequence batch reactor designed for nitrification in activated sludge. Oxidation of the leachate was then O3, O3/pH adjustment (pH 9 and 10), H2O2, O3/H2O2 and performic acid in lab-scale reactors.

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By emphasising the involvement of elderly people in a project applying a mixed-method approach, the overriding objective of this study was to identify and prioritise concrete measures aimed at increasing accessibility and safety in the outdoor pedestrian environment within a residential area of a Swedish town. Measures generally given priority were: the separation of pedestrians/cyclists, lower speed limits, better maintenance and specific measures in pedestrian walkways such as wider sidewalks, curb levels and form and more even surfaces on pavements. Definition of these priorities offered knowledge to the highway department concerning the importance of small details in relation to the larger infrastructure.

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Spline-based cardiac motion tracking using velocity-encoded magnetic resonance imaging.

IEEE Trans Med Imaging

August 2008

Centre for Mathematical Sciences, Lund Institute of Technology and the Department of Clinical Physiology, Lund University Hospital, S-221 85 Lund, Sweden.

This paper deals with the problem of tracking cardiac motion and deformation using velocity-encoded magnetic resonance imaging. We expand upon an earlier described method and fit a spatiotemporal motion model to measured velocity data. We investigate several different spatial elements both qualitatively and quantitatively using phantom measurements and data from human subjects.

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A method for 3D mapping of scattering particle concentration in a gaseous medium based on the backscattered light in a single direction has been demonstrated. The technique is originally developed for microscopy but now implemented on larger-scale samples. The technique used is known as structured illumination, where a sinusoidal grid pattern is projected onto the medium, thus marking the in-focus plane.

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