BACKGROUND Direct sputum smear microscopy is the mainstay of TB diagnosis in most low and middle income countries, and is highly specific for Mycobacterium tuberculosis in such settings. However it is limited by low sensitivity, particularly in HIV co-infected patients. Concentration by centrifugation has been reported to be more sensitive than direct smear preparation, but is only suitable for...

This paper presents work on the development of a microfluidic device using super-paramagnetic beads for sampling and mixing. The beads are manipulated via an external rotating permanent magnet in a microfluidic channel. Efficient mixing is achieved in a short distance with this method. Modeling shows the variables which influence the mixing are flow rate, bead rotation speed and the bead number...

It is shown how the phase-space kinetic theory of polymeric liquid mixtures leads to a set of extended Maxwell-Stefan equations describing multicomponent diffusion. This expression reduces to standard results for dilute solutions and for undiluted polymers. The polymer molecules are modeled as flexible bead-spring structures. To obtain the Maxwell-Stefan equations, the usual expression for the ...

We have developed a miniaturized bead-beating device to automate nucleic acids extraction from Gram-positive bacteria for molecular diagnostics. The microfluidic device was fabricated by sandwiching a monolithic flexible polydimethylsiloxane (PDMS) membrane between two glass wafers (i.e., glass-PDMS-glass), which acted as an actuator for bead collision via its pneumatic vibration without additi...

B-Mode, linear array ultrasonography was used to evaluate the site of semen deposition in live cows. The insemination sheath was modified to hold a brass bead that was deposited at the simulated site of semen deposition. The position of the bead was identified by ultrasonography and the bead was recovered by pulling a nylon line that was attached to the bead. An ultrasound technician identified...

Golgi complex beads are 10-nm particles arranged in rings on the smooth surface of rough endoplasmic reticulum (ER) makind the forming face of the Golgi complex (GC). In arthropod cells they stain specifically with bismuth. Their morphology has been studied after treatment with reagents known to interfere with GC function. Inhibitors of oxidative phosphorylation (antimycin A, cyanide, and anoxi...

This paper presents a deterministic bead-in-droplet ejection (BIDE) technique that regulates the precise distribution of microbeads in an ejected droplet. The deterministic BIDE was realized through the effective integration of a microfluidic single-particle handling technique with a liquid dispensing system. The integrated bead dispenser facilitates the transfer of the desired number of beads ...

The tethered-particle method is a single-molecule technique that has been used to explore the dynamics of a variety of macromolecules of biological interest. We give a theoretical analysis of the particle motions in such experiments. Our analysis reveals that the proximity of the tethered bead to a nearby surface (the microscope slide) gives rise to a volume-exclusion effect, resulting in an en...

A number of welding parameters are responsible for the quality of welds. The modeling of weld bead shape is important for predicting the quality of welds. In this paper, an attempt has been made to develop a back-propagation neural network (BPNN) model for the prediction of reinforcement height and width of bead in GTA bead-on plate welding process. The experimental results were used as testing...

The aim of this study is to investigate the optimization process parameters for Metal inert gas welding (MIG). In the present work, bead-on -plate welds were carried out on MS 5986 Fe 410 carbon steel sheets using Gas Metal Arc Welding (GMAW) process. In this present investigation ER70S-6 solid wire having 1.2 mm diameter was used as an electrode with direct current electrode positive polarity....