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Costs of COPD in Sweden according to disease severity

Objectives: COPD is a common and disabling disease that entails high costs for society. The objectives of this study were to measure the societal costs of COPD in Sweden, and to examine the relationship between severity of illness and costs. Methods: The costs of COPD were examined using a well-defined and representative cohort of subjects with mild, moderate, and severe COPD. Regular telephone in

Chimpanzees like to copy human visitors to the zoo - Ig Nobel prize

How good is your best chimpanzee impression? Go to the zoo and you probably wouldn’t be surprised to see people copying chimpanzees in order to grab their attention. But our latest research, which recently won the Ig Nobel Prize for Anthropology, suggests you are just as likely to see chimpanzees imitating the human visitors.

Changes in clinical characteristics, course, and prognosis of inflammatory bowel disease during the last 5 decades : A population-based study from Copenhagen, Denmark

Background: It remains uncertain whether the increasing incidence of inflammatory bowel disease (IBD) during the last decades has been accompanied by an alteration in the presentation, course, and prognosis of the disease. To answer this question, 3 consecutive population-based IBD cohorts from Copenhagen, Denmark (1962-2005), were assessed and evaluated. Methods: Phenotype, initial disease course

The Swedish cost burden of overweight and obesity - Evaluated with the PAR approach and a statistical modelling approach

The rising trend in the prevalence of obesity, which is a major risk factor for a number of diseases notably diabetes and cardiovascular diseases, has become a major public health concern in many countries during the past decades. This development has also led to an increased cost burden on the public health care delivery system that has been documented in many studies. The standard approach taken

Microfluidic connections to hollow nanowires

We have fabricated a device in which hollow nanowires (HNWs) lying on a glass surface are connected to microfluidic channels for the purpose of guiding DNA and to characterize the fluidic properties of our HNWs. The dimensions of our HNWs (inner diameter 10-80 nm, outer diameter 50-200 nm and length several μm) can be made on a scale much smaller than the size of a cell and on the same order of ma

Morphology-based sorting-blood cells and parasites

Morphology represents a hitherto unexploited source of specificity in microfluidic particle separation and may serve as the basis for label-free particle fractionation. There is a wealth of morphological changes in blood cells due to a wide range of clinical conditions, diseases, medication and other factors. Also, blood-borne parasites differ in morphology from blood cells. We present the use of

Fluorescence enhancement from single DNA molecules confined in SiO 2 nanochannels

We demonstrate that the detected emission intensity from YOYO-labeled DNA molecules confined in 180 nm deep Si/SiO2 nanofunnels changes significantly and not monotonically with the width of the funnel, an emission enhancement that is only detected for emitted light polarized parallel to the channel. We explain the enhancement effect as being due to optical phenomena in the channels. The enhancemen

Vertical nanotubes connected by a subsurface nanochannel

We have built an array of vertical nanotubes connected by a subsurface nanofluidic channel. The nanotube system is to be used for cell injections. By culturing cells on top of the nanotubes the cells will be pierced and molecules can enter the cells via the subsurface channel. Several channels can be made on the same sample and different molecules can be injected into different subpopulations of c

Capillary driven separation on patterned surfaces

Deterministic lateral displacement (DLD) is a powerful bimodal separation scheme [1] based on fluid flow through regular obstacle arrays that in its basic embodiment sends suspended particles in two different directions as a function of size. We show that without the need to seal devices and without the need for fluidic connections or pumps, particle separation can be achieved by the passive flow

Gravitationally driven deterministic lateral displacement devices

Deterministic lateral displacement (DLD) is a powerful bimodal separation scheme [1] based on regular obstacle arrays that in its basic embodiment sends particles in two different directions as a function of size. We add functionality to the technique by including gravitational forces, as a perturbation to particles transported by fluid flow, and as a way of transporting the particles through a st

Shape-based particle sorting - A new paradigm in microfluidics

Conventional fractionation techniques fail to fully benefit from the variety in morphology and shape that is found among biological particles. Although light scattering in conventional FACS gives some information on the size and morphology of a particle, it is generally not capable of giving a definite number on specified dimensions of a small object. We demonstrate an approach where we select whi

Throughput through thin-film fluidics

We demonstrate fluidics realized in thin film plastic foils patterned using roll-toroll nanoimprinting lithography (rrNIL). Realizing fluidics devices in thin plastic foils opens up for parallel operation in stacked devices. It also provides a convenient format for storage and distribution of the devices.

Tipping the balance with dielectrophoretic forces - An electric deterministic lateral displacement device

We present experimental results and simulations on a simple method for tunable particle separation based on a combination of Deterministic Lateral Displacement (DLD) and Insulator Based Dielectrophoresis (I-DEP). Rather than deriving its tunability from its elastic properties[1], our present device uses an applied AC field to perturb the particle trajectories in the pressure-driven flow and is the

Melting mapping in nanochannels

We demonstrate direct visualization of melting mapping of DNA stretched in nanoscale channels[1] using standard staining methods and epifluorescence microscopy to gain information on the local AT/GC ratio along large DNA molecules. Our development opens up a novel route to mapping of large-scale genomic variations.

Polarization anisotropy of DNA in nanochannels

The local alignment of DNA stretched in nanofluidic channels is measured using polarization sensitive detection. With increased degree of stretching the polarization anisotropy increases both in the deGennes and the Odijk regime. The technique is expected to find use in studies of, for example, local conformational changes in polymer physics in confined spaces, studies of protein-DNA interactions

Polarization dependence of light intensity distribution from nanometer metallic slits

In this work, the near-field and far-field electric magnetic (EM) wave distributions of metallic slits was observed using tapered fiber probe and modelled using finite difference time domain (FDTD) computer simulations. The EM wave field distribution from rectangular slits with widths 100 nm, 300 nm, and 500 nm was mapped with excitation wavelength λ = 532 nm. λ/2 can be considered a characteristi

Sacrificial polymers for nanofluidic channels in biological applications

Chip based bio/chemical analysis relies on networks of fluidic channels that are connected to reaction chambers and sensors. For sensitive detection it is important to scale down the size of the channels so that they approach the relevant length scales of the molecules of interest. Here we have made sealed channels on the 100 nm scale using nanoimprinting to pattern the sacrificial polymer polynor

A DNA prism : Physical principles for optimizing a microfabricated DNA separation device

Recently, we reported a microfabricated "DNA prism" device that continuously sorts large DNA molecules (61 kilobase pair to 209 kb) according to size in 15 seconds. In this paper, we develop models to understand and optimize the device. The device's complicated characteristics are explained poorly by a simple model based on the assumption that DNA molecules are fully stretched. Assuming DNA molecu