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Buffer medium exchange in continuous cell and particle streams using ultrasonic standing wave focusing

A microfluidic strategy to perform buffer exchange of particle and cell suspensions in a continuous flow format on, chip is presented. Ultrasonic standing wave technology is utilized to confine particulate matter to the centre of a buffer exchange channel while particle free buffer is sequentially aspirated via capillaries that branch off from the buffer exchange channel. At each such branch, clea

Environment, social interaction, and physical activity as determinants of functional outcome after cerebral infarction in the rat

Rats housed in an enriched environment allowing both social interaction and physical activity improve more than rats housed in standard laboratory cages after focal brain ischemia. To determine the relative importance of social and physical activity, rats that sustained ligation of the middle cerebral artery were kept in an enriched environment with opportunities for various activities (group A),

Levels of bacterial endotoxin in air of animal houses determined with the use of gas chromatography - Mass spectrometry and Limulus test

Air samples were collected on glass fibre filters in 22 animal houses and 3 hay storage barns and examined for the presence of bacterial endotoxin with the Limulus (LAL) test and the gas chromatography - tandem mass spectrometry (GC-MSMS) technique, based on detection of 3-hydroxy fatty acids (3-OH-FAs) as chemical markers of the endotoxin lipopolysaccharide. The median concentrations of airborne

Pore size distribution and water uptake in hydrocarbon and perfluorinated proton-exchange membranes as studied by NMR cryoporometry

Sulfonated polysulfone (sPSU) membranes were analysed by nuclear magnetic resonance (NMR) cryoporometry, conventional gravimetric water uptake measurements as well as by differential scanning calorimetry (DSC). NMR cryoporometry is based on the relation between the pore size and the melting point depression of the pore-filling liquid, i.e. water in fuel cell membranes; thus providing a relation be

No Increased Occurrence of Ischemic Heart Disease Prior to the Onset of Rheumatoid Arthritis Results From Two Swedish Population-Based Rheumatoid Arthritis Cohorts

Objective. To investigate the relative importance of shared etiologies for rheumatoid arthritis (RA) and ischemic heart disease (IHD) in terms of the well-known increased risk of HID in patients with RA, by assessing the occurrence of IHD up until the time of the onset of the first symptoms of RA. Methods. We assessed the prevalence of a history of IHD, myocardial infarction (MI), and angina pecto

Fast delivery of meteorites to Earth after a major asteroid collision

Very large collisions in the asteroid belt could lead temporarily to a substantial increase in the rate of impacts of meteorites on Earth. Orbital simulations predict that fragments from such events may arrive considerably faster than the typical transit times of meteorites falling today, because in some large impacts part of the debris is transferred directly into a resonant orbit with Jupiter(1,

Anastomotic healing in the rat colon: comparison between a radiological method, breaking strength and bursting pressure.

Background and aims: While mechanical parameters (breaking strength, bursting pressure) are used to measure colonic anastomotic healing, reported values are inconsistent. This study developed a novel approach to study colonic anastomotic repair and compared it with mechanical methods. Methods and materials: We created standardized four- and eight-suture colonic anastomoses and performed contrast e

Increased plasma levels of serine proteinase inhibitors in lung cancer patients.

BACKGROUND: Tumor growth and invasiveness occur through infiltration of tumor cells into the host cells and by angiogenesis, which is modulated by proteinases and antiproteinases released from tumor cells that carry out tissue remodelling. A number of studies have revealed variations in the plasma levels of serine proteases and their inhibitors among tumor types. PATIENTS AND METHODS: By immunolog

Dynamic behaviour of the common femoral artery: age and gender of minor importance

The distensibility of elastic arteries has been extensively studied, while studies of muscular arteries are sparse. The influences of age and gender on the mechanical properties of the common femoral artery (CFA) were studied. The pulsatile diameter changes of the CFA were noninvasively measured using echo-tracking sonography in 173 healthy volunteers (95 females, 78 males, range 7-81 years). In c

Upregulation of endothelin ETB receptor-mediated vasoconstriction in rat coronary artery after organ culture

The aim of this study was to examine if endothelin ETB receptor-mediated contraction occurred in isolated segments of rat coronary arteries during organ culture. Presence of contractile endothelin ETB receptors was studied by measuring the change in isometric tension in rings of left anterior descending coronary arteries isolated from hearts of rats as response to application of the selective endo

Prototype hybrid couplings of macroscopic deterministic models and microscopic stochastic lattice dynamics

We study a class of model prototype hybrid systems comprised of a microscopic Arrhenius surface process describing adsorption/desorption and/or surface diffusion of particles coupled to an ordinary differential equation displaying bifurcations triggered by the microscopic process. The models proposed here are caricatures of realistic systems arising in diverse applications ranging from surface pro

The direct product permuting matrices

A new matrix product is defined and its properties are investigated. The commutatuion matrix which flips a left direct product of two matrices into a right direct one is derived as a composition of two identity matrices. The communication matrix is a special case of the direct product permuting matrices defined in this paper which are matrix representations of the permutation operators on tensor s

Quantitative proteomic analysis of fibroblast nuclear proteins after stimulation with mitogen activated protein kinase inhibiting heparan sulfate

Certain structures of heparan sulfate (HS) inhibit cell proliferation of fibroblasts. Whether this inhibition is dependent on inhibition of mitogenic signaling pathways or nuclear translocation of HS is unknown. In this study we investigated possible mechanism(s) and structural requirements by which antiproliferative glycosaminoglycans exert their effects on mitogen-activated protein kinase (MAP k

Process-based estimates of terrestrial ecosystem isoprene emissions: incorporating the effects of a direct CO2-isoprene interaction

In recent years evidence has emerged that the amount of isoprene emitted from a leaf is affected by the CO2 growth environment. Many - though not all - laboratory experiments indicate that emissions increase significantly at below-ambient CO2 concentrations and decrease when concentrations are raised to above-ambient. A small number of process-based leaf isoprene emission models can reproduce this

In situ crack growth studies of hydrided Zircaloy-4 on a single-edge notched tensile specimen

The strains in matrix and hydrides around a fatigue crack tip grown in situ in a single-edge notched specimen of hydrided Zircaloy-4 have been determined using synchrotron X-ray diffraction at various stages of loading. The hydride phase shows proportionally larger strains at full load compared to the matrix strain. The residual strains of the matrix ahead of the crack tip reveal the reverse plast

Retained heterodisomy for chromosome 12 in atypical lipomatous tumors: implications for ring chromosome formation.

Atypical lipomatous tumor (ALT) is an intermediate malignant mesenchymal tumor that is characterized by supernumerary ring chromosomes and/or giant rod-shaped marker chromosomes (RGMC). Fluorescence in situ hybridization ( FISH) and molecular genetic analyses have disclosed that the RGMCs always contain amplified sequences from the long arm of chromosome 12. Typically, RGMCs are the sole clonal ch

Ultrafiltration of kraft cooking liquors from a continuous cooking process

Two cooking liquors and a black liquor were fractionated by ultrafiltration. The liquors were withdrawn from different stages in a kraft pulp mill employing continuous digestion. The ultrafiltration was performed at 90 degrees C with two ceramic membranes with cut-offs of 5 kDa and 15 kDa. Only small differences in membrane performance were observed when concentrating the three liquors to 90% volu

Prognostic significance of chromosome aberrations in high-grade soft tissue sarcomas

Purpose To investigate whether previously observed correlations between tumor karyotype and risk of metastases could be reproduced in an independent set of high-grade soft tissue sarcomas (STSs). Patients and Methods In a previous study on high-grade STSs with clonal chromosome aberrations, we identified a number of cytogenetic variables, besides tumor grade and size, that were associated with sig

Human age and vehicle speeds affect on vehicle ingress motion pattern

The vehicle ingress and egress are important issues for the automotive industry, both for minimizing assembly work load and for maximizing end-users’ comfort. Digital human modeling tools are used for evaluating and visualizing these issues. The assembler and end-user are more or less performing the very same entering task if the vehicles have identical geometrical prerequisites. The major differe

Total heart volume variation throughout the cardiac cycle in man.

Variations in total heart volume (atria plus ventricles) during a cardiac cycle affect efficiency of cardiac pumping. The goals of this study were to confirm the presence, extent, and contributors of total heart volume variation during the cardiac cycle in healthy volunteers with the use of MRI. Eight healthy volunteers were examined by MRI at rest. Changes in total cardiac volume throughout the c