Thiamine deficiency disorders: diagnosis, prevalence, and a roadmap for global control programs.

Thiamine is an essential micronutrient that plays a key role in energy metabolism. Many populations worldwide may be at risk of clinical or subclinical thiamine deficiencies, due to famine, reliance on staple crops with low thiamine content, or food preparation practices, such as milling grains and washing milled rice. Clinical manifestations of thiamine deficiency are variable; this, along with the lack of a readily accessible and widely agreed upon biomarker of thiamine status, complicates efforts to diagnose thiamine deficiency and assess its global prevalence.

A novel portable filtration system for sampling and concentration of microorganisms: Demonstration on marine microalgae with subsequent quantification using IC-NASBA.

This paper presents a novel portable sample filtration/concentration system, designed for use on samples of microorganisms with very low cell concentrations and large volumes, such as water-borne parasites, pathogens associated with faecal matter, or toxic phytoplankton. The example application used for demonstration was the in-field collection and concentration of microalgae from seawater samples. This type of organism is responsible for Harmful Algal Blooms (HABs), an example of which is commonly referred to as "red tides", which are typically the result of rapid proliferation and high biomass accumulation of harmful microalgal species in the water column or at the sea surface.

Open-Source Potentiostat for Wireless Electrochemical Detection with Smartphones.

This paper describes the design and characterization of an open-source "universal wireless electrochemical detector" (UWED). This detector interfaces with a smartphone (or a tablet) using "Bluetooth Low Energy" protocol; the smartphone provides (i) a user interface for receiving the experimental parameters from the user and visualizing the result in real time, and (ii) a proxy for storing, processing, and transmitting the data and experimental protocols. This approach simplifies the design, and decreases both the size and the cost of the hardware; it also makes the UWED adaptable to different types of analyses by simple modification of the software.

Handheld isothermal amplification and electrochemical detection of DNA in resource-limited settings.

This paper demonstrates a new method for electrochemical detection of specific sequences of DNA present in trace amounts in serum or blood. This method is designed for use at the point-of-care (particularly in resource-limited settings). By combining recombinase polymerase amplification (RPA)- an isothermal alternative to the polymerase chain reaction - with an electroactive mediator, this electrochemical methodology enables accurate detection of DNA in the field using a low-cost, portable electrochemical analyzer (specifically designed for this type of analysis).

Sliding-strip microfluidic device enables ELISA on paper.

This article describes a 3D microfluidic paper-based analytical device that can be used to conduct an enzyme-linked immunosorbent assay (ELISA). The device comprises two parts: a sliding strip (which contains the active sensing area) and a structure surrounding the sliding strip (which holds stored reagents-buffers, antibodies, and enzymatic substrate-and distributes fluid). Running an ELISA involves adding sample (e.

Detection and quantification of the toxic microalgae Karenia brevis using lab on a chip mRNA sequence-based amplification.

Now and again, the rapid proliferation of certain species of phytoplankton can give rise to Harmful Algal Blooms, which pose a serious threat to marine life and human health. Current methods of monitoring phytoplankton are limited by poor specificity or by the requirement to return samples to a highly resourced, centralised lab. The Lab Card is a small, microfluidic cassette which, when used in tandem with a portable Lab Card Reader can be used to sensitively and specifically quantify harmful algae in the field, from nucleic acid extracts using RNA amplification; a sensitive and specific method for the enumeration of potentially any species based on their unique genetic signatures.

Rapid and sensitive detection of antibiotic resistance on a programmable digital microfluidic platform.

The widespread dissemination of CTX-M extended spectrum β-lactamases among Escherichia coli bacteria, both in nosocomial and community environments, is a challenge for diagnostic bacteriology laboratories. We describe a rapid and sensitive detection system for analysis of DNA containing the blaCTX-M-15 gene using isothermal DNA amplification by recombinase polymerase amplification (RPA) on a digital microfluidic platform; active matrix electrowetting-on-dielectric (AM-EWOD). The devices have 16,800 electrodes that can be independently controlled to perform multiple and simultaneous droplet operations.

A fluorogenic heterogeneous immunoassay for cardiac muscle troponin cTnI on a digital microfluidic device.

We describe a fluorogenic two-site noncompetitive heterogeneous immunoassay with magnetic beads on a low-voltage digital microfluidic platform using closed electrowetting-on-dielectric (EWOD). All the steps of an enzyme-linked immunosorbent assay (ELISA) were performed on the device using 9H-(1, 3-dichloro-9, 9-dimethylacridin-2-one-7-yl) phosphate as the fluorogenic substrate for the enzyme alkaline phosphatase. The performance of the system was demonstrated with cardiac marker Troponin I (cTnI) as a model analyte in phosphate-buffered saline samples.

Real-time isothermal RNA amplification of toxic marine microalgae using preserved reagents on an integrated microfluidic platform.

Quantitation of specific RNA sequences is a useful technique in marine biology that can elucidate cell abundance, speciation and viability, especially for early detection of harmful algal blooms. We are thus developing an integrated microfluidic system for cell concentration and lysis, RNA extraction/purification and quantitative RNA detection for environmental applications. The portable system is based on a microfluidic cartridge, or "lab-card", using a low-cost injection moulded device, with a laminated lid.

The effect of lipids on the enzymatic activity of 6-phosphofructo-1-kinase from B. stearothermophilus.

6-Phosphofructo-1-kinase (PFK-1), a major regulatory enzyme in the glycolysis pathway, is a cytoplasmic enzyme with complicated allosteric kinetics. Here we investigate the effects of lipids on the activity of PFK from Bacillus stearothermophilus (BsPFK), to determine whether BsPFK shares any of the membrane binding or lipid binding properties reported for some mammalian PFKs. Our results show that large unilamellar vesicles (LUVs) composed of either the phospholipid 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) or of 1:1 (mole ratio) DOPC and the fatty acid, oleic acid (OA), cause a three-fold increase in V(max), depending on the lipid concentration and vesicle composition, but no change in K(m).