Effective microchip extraction of deoxyribonucleic acid (DNA) from crude biological matrixes has been demonstrated using silica beads or hybrid phases composed of beads and sol-gel. However, the use of monolithic sol-gels alone for extraction of human genomic DNA has been more difficult to define. Here we describe, for the first time, the successful use of monolithic tetramethyl orthosilicate-based sol-gels for effective micro-solid-phase extraction (muSPE) of DNA in a glass microchip format. A functional monolithic silica phase with micrometer-scale pores in the silica matrix resulted from addition of poly(ethylene glycol), a poragen, to the precursor mixture. This allowed a monolithic sol-gel bed to be established in a microchip channel that provided large surface area for DNA extraction with little flow-induced back pressure. DNA extraction efficiencies for simple systems (lambda-phage DNA) were approximately 85%, while efficiencies for the reproducible extraction of human genomic DNA from complex biological matrixes (human blood) were approximately 70%. Blockage of the sol-gel pores by components in the lysed blood was observed in repeat extraction on a single device as a decrease in the extraction efficiency. The developed muSPE protocol was further evaluated to show applicability to clinical samples and bacterial cultures, through extraction of PCR-amplifiable DNA.

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The purpose of the present study was to investigate the effect of the A(2A) receptor antagonist (SCH 442416) on the mRNA expression of glutamate aspartate transporter (GLAST) and glutamine synthetase (GS) in rat retinal Müller cells under hypoxic conditions in vitro. Immunofluorescent staining of GS and GFAP was used for the identification of Müller cells. The GLAST and GS mRNA expression of Müller cells treated with 0.1, 1 and 10 μM SCH 442416 under hypoxic conditions was examined by real-time PCR. Müller cells increased the mRNA expression of GLAST under hypoxic conditions; those treated with 0.1 μM SCH 442416 showed a further significant increase in the mRNA expression of GLAST in vitro. Although the mRNA expression of GS was decreased under hypoxic conditions, the mRNA expression was increased when Müller cells were treated with 0.1 μM SCH 442416. A(2A) receptor antagonist increased the GLAST and GS expression of Müller cells and accelerated the clearance of extracellular glutamate under hypoxic conditions in vitro.

Coal is still a major energy source, mostly used in power plants. However, the coal combustion emits harmful SO 2 and fly ash. Wet flue gas desulfurization (WFGD) technology is extensively used to control SO 2 emissions in power plants. However, only limited studies have investigated the synergistic dust removal by the WFGD system. Spray scrubbers and sieve-tray spray scrubbers are often used in WFGD systems to improve the SO 2 removal efficiency. In this study, the synergistic dust removal of WFGD systems for a spray scrubber and a sieve-tray spray scrubber was investigated using the experimental and modelling approaches, respectively. For the spray scrubber, the influence of parameters, including dust particle diameters and inlet concentrations of dust particles, and the flow rates of flue gas and slurry of limestone/gypsum on the dust removal efficiency, was investigated. For the sieve-tray spray scrubber, the influence of parameters such as the pore diameter and porosity of sieve trays on the dust removal efficiency was examined. The study found that the dust removal efficiency in the sieve-tray spray scrubber was approximately 1.1–10.6% higher than that of the spray scrubber for the same experimental conditions. Based on the parameters investigated and geometric parameters of a scrubber, a novel droplets swarm model for dust removal efficiency was developed from the single droplet model. The enhanced dust removal efficiency of sieve tray was expressed by introducing a strength coefficient to an inertial collision model. The dust removal efficiency model for the sieve-tray spray scrubber was developed by combining the droplets swarm model for the spray scrubber with the modified inertial collision model for the sieve tray. The results simulated using both models are consistent with the experimental data obtained.

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