Microreactor technology has shown potential for optimizing synthetic efficiency, particularly in preparing sensitive compounds. We achieved the synthesis of an [ 18 F]fluoride-radiolabeled molecular imaging probe, 2-deoxy-2-[ 18 F]fluoro- d -glucose ([ 18 F]FDG), in an integrated microfluidic device. Five sequential processes—[ 18 F]fluoride concentration, water evaporation, radiofluorination, solvent exchange, and hydrolytic deprotection—proceeded with high radio-chemical yield and purity and with shorter synthesis time relative to conventional automated synthesis. Multiple doses of [ 18 F]FDG for positron emission tomography imaging studies in mice were prepared. These results, which constitute a proof of principle for automated multistep syntheses at the nanogram to microgram scale, could be generalized to a range of radiolabeled substrates.

An improved approach composed of an oxidation reaction in acidic H2O2 solution and a sequential silanization reaction using neat silane reagents for surface modification of poly(dimethylsiloxane) (PDMS) substrates was developed. This solution-phase approach is simple and convenient for some routine analytical applications in chemistry and biology laboratories and is designed for intact PDMS-based microfluidic devices, with no device postassembly required. Using this improved approach, two different functional groups, poly(ethylene glycol) (PEG) and amine (NH2), were introduced onto PDMS surfaces for passivation of nonspecific protein absorption and attachment of biomolecules, respectively. X-ray electron spectroscopy and temporal contact angle experiments were employed to monitor functional group transformation and dynamic characteristics of the PEG-grafted PDMS substrates; fluorescent protein solutions were introduced into the PEG-grafted PDMS microchannels to test their protein repelling characteristics. These analytical data indicate that the PEG-grafted PDMS surfaces exhibit improved short-term surface dynamics and robust long-term stability. The amino-grafted PDMS microchannels are also relatively stable and can be further activated for modifications with peptide, DNA, and protein on the surfaces of microfluidic channels. The resulting biomolecule-grafted PDMS microchannels can be utilized for cell immobilization and incubation, semiquantitative DNA hybridization, and immunoassay.

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The current prevalence of erosive esophagitis in Taiwan is 17.3%. Male sex, smoking, obesity, and hiatus hernia are four independent risk factors for the development of erosive esophagitis in the Taiwanese population.

Glycerol utilization is an important research topic because of recent surging biodiesel production through transesterification of vegetable oils and animal fats. One of the valuable products from glycerol is gained through esterification with acetic acid to produce triacetin. Hasabnis and Mahajani proposed an entrainer-based reactive column configuration with stoichiometric feed ratio to obtain high selectivity and conversion. This paper corrects the kinetic parameters in Hasabnis and Mahajani to better describe this reaction system. A more effective reactive entrainer for this reactive distillation system is also proposed to better carry water to the top of the column. The other modification is to assume feed compositions of the glycerol and acetic acid feed streams containing some water as impurity as opposed to idealistic pure feed assumptions. The operation and control of this system are also investigated. The proposed tray-temperature control strategy is able to maintain product purity despite disturbances from throughput and feed composition changes.

A Mach–Zehnder device is utilized in a nonzero‐order joint‐transform correlator system for aircraft pattern recognition. The Stokes relations, which involve the amplitudes of reflected and transmitted parts of a plane wave incident on a plane‐refracting surface, are cleverly utilized. The proposed method can directly remove the large zero‐order term in one step. The correlator also shows the advantage of the ability to detect distortion invariance. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 1290–1293, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21623

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