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A high-throughput deterministic lateral displacement device for rapid and sensitive field-diagnosis of sleeping sickness

We present a simple and rapid microfluidic device capable of extracting and concentrating the parasite causing the fatal disease sleeping sickness (SS) from blood. The device is based on deterministic lateral displacement (DLD) and constructed with a single inlet with flow induced by an ordinary syringe. The simplicity is crucial as the device is intended for use in the resource depraved areas whe

Sample preparation for single-cell whole chromosome analysis

In this work we present an integrated system for whole chromosome analysis of single bacterium. Using whole genome barcoding techniques, which offer direct and rapid microscopic visualization of the entire genome in one field-of-view, we aim to rapidly identify individual bacterium. We are developing our device to achieve the crucial, and difficult process of isolating a bacterium, removing the DN

Meandering nanochannels for imaging of ultra-long DNA molecules

A new chip design for handling and studying chromosomal DNA is described. Folding the nanochannels enables us to image an entire yeast chromosome in a single field of view. Together with existing mapping techniques our new design opens up the possibility of directly analyzing entire chromosomes in a single field of view using fluorescence microscopy. This would enable, for example, identification

Fluorescence microscopy of nanochannel-confined DNA

Stretching of DNA in nanoscale confinement allows for direct visualization of the genetic contents of the DNA on the single DNA molecule level. DNA stretched in nanoscale confinement also allows for studies of DNA-protein interactions and DNA polymer physics in confined environments. This chapter describes the basic steps to fabricate the nanostructures, to perform the experiments, and to analyze

Cell morphology and deformability in deterministic lateral displacement devices

Deterministic Lateral Displacement (DLD) devices have been used to separate particles based on size [1] and shape [2]. Here we show how DLD devices can also be used to separate particles based on their ability to deform under shear forces. Varying experimental conditions allows us to vary the relative contributions of size, morphology and deformability. The ability to distinguish between cells bas

Multiple depths in a deterministic lateral displacement device for field-diagnosis of sleeping-sickness

We present a simple and inexpensive device capable of extracting and concentrating the parasite causing sleeping sickness from blood. The device is aimed at being used in rural resource depraved areas where the disease is endemic; therefore simplicity is of paramount importance. The device is based on deterministic lateral displacement with a single inlet and flow induced by a syringe. Through an

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.