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As a consequence of organophosphorus (OP) toxins posing a threat to human life globally, organophosphorus hydrolase (OPH) has become the enzyme of choice to detoxify such compounds. Organophosphorus hydrolase was covalently immobilized onto a quartz substrate for utilization in paraoxon detection. The substrate was cleaned and modified prior to chemical attachment. Each modification step was monitored by imaging ellipsometry as the thickness increased with each modification step. The chemically attached OPH was labeled with a fluorescent dye (7-isothiocyanato-4-methylcoumarin) for the detection of paraoxon in aqueous solution, ranging from [10.sup.-9] to [10.sup.-5] M. UV-visible spectra were also acquired for the determination of the hydrolysis product of paraoxon, namely p-nitrophenol.

We report genetic maps for diploid (D) and tetraploid (AtDt) Gossypium genomes composed of sequence-tagged sites (STS) that foster structural, functional, and evolutionary genomic studies. The maps include, respectively, 2584 loci at 1.72-cM (~600 kb) intervals based on 2007 probes (AtDt) and 763 loci at 1.96-cM (~500 kb) intervals detected by 662 probes (D). Both diploid and tetraploid cottons exhibit negative crossover interference; i.e., double recombinants are unexpectedly abundant. We found no major structural changes between Dt and D chromosomes, but confirmed two reciprocal translocations between At chromosomes and several inversions. Concentrations of probes in corresponding regions of the various genomes may represent centromeres, while genome-specific concentrations may represent heterochromatin. Locus duplication patterns reveal all 13 expected homeologous chromosome sets and lend new support to the possibility that a more ancient polyploidization event may have predated the A-D divergence of 6-11 million years ago. Identification of SSRs within 312 RFLP sequences plus direct mapping of 124 SSRs and exploration for CAPS and SNPs illustrate the 'portability' of these STS loci across populations and detection systems useful for marker-assisted improvement of the world's leading fiber crop. These data provide new insights into polyploid evolution and represent a foundation for assembly of a finished sequence of the cotton genome.

Efficacy of chlorine dioxide (CD) gas generated by two distinct generation systems, Sabre and ClorDiSys was evaluated for inactivation of Bacillus anthracis spores on six building interior surfaces. The results showed that the time required to achieve at least a 6-log reduction in viable spores is influenced by a function of the material type on which the spores are inoculated.

The X-ray structure characterization of the native organophosphate acid anhydrolase (OPAA) (58 kDa mass) from Alteromonas sp. strain JD6.5 and its cocrystal with the inhibitor mipafox [N,N'-diisopropyldiamidofluorophosphate (DDFP)], a close analogue of the nerve agent organophosphate substrate diisopropyl fluorophosphate (DFP) is reported. The findings for structures of both ligands provide new insight into the ligand recognition and the prolidase and organophosphorus hydrolase catalytic activities of OPAA.

The sporicidal efficacies of the two fumigants, chlorine dioxide gas and vaporous hydrogen peroxide sterilant, on six building structural materials are studied. A high-throughput quantitative method is developed for determining the efficacies of fumigants and the spore recoveries from five porous materials and on nonporous material.

A study was conducted to characterize the secondary structure of the organophosphorus acid anhydrolase (OPAA) Langmuir monolayer in the absence and presence of diisopropylfluorophosphate (DFP) in the subphase.

A novel biosensor for the detection of the paraoxon, based on (CdSe)ZnS core-shell quantum dots (QDs) and an organophosphorus hydrolase (OPH) biconjugate, was reported. The OPH was coupled to (CdSe)ZnS core-shell QDs through electrostatic interaction between negatively charged QDs surfaces and the positively charged protein side chain and ending groups.

The secondary structure of organophosphorus hydrolase (OPH) has been studied with circular dichroism spectroscopy. The effect of pH on the secondary structure of OPH solution has been examined over the pH range from 3.56 to 9.60.

The versatility of the layer-by-layer (LbL) system is explored where the multilayers of chitosan (CS), thioglycolic acid (TGA)-capped CdSe QDs, and OPH polyelectrolytes are incorporated into the LbL architecture. The fabricated LbL thin film showed an attractive alternative to using polyelectrolytes with optical properties for biosensing assembly use.

Chemical, biological, radiological, and explosive incidents produce immediate as well as delayed hazards as a result of reaerosolization of deposited particles from surfaces. Understanding reaerosolization mechanisms is important for hazard prediction and mitigation processes. A method to efficiently reaerosolize 1–5 µm particles (approximately the size of bacterial spores) has not been previously available; therefore, this study was conducted to test a simple and effective method to reaerosolize such particles. In this work, a high-speed vertical impinging jet was used to reaerosolize 1–5 µm polystyrene latex microspheres from a substrate, and measured removal efficiencies were compared with the performed numerical predictions. Experiments were conducted to determine the effect of location, number of pulsed air jets, particle size, aerosol generation methodology (wet and dry), and relative humidity (RH) on the amount of reaerosolization. The experimental results agreed with the numerical predictions and demonstrated that maximal reaerosolization efficiency (∼90% in several cases) occurs at a few millimeters from the jet center. At the peak removal location, reaerosolization increased with increasing particle size and with increasing number of pulsed air jets. Dry deposited particles exhibited significantly higher reaerosolization compared to wet deposited particles. Equilibration of samples at low (20%) RH showed higher reaerosolization compared to the high RH conditions for dry deposited particles. This study demonstrates the effectiveness of using a single vertical impinging jet for localized reaerosolization of bacteria-sized particles from surfaces. [ABSTRACT FROM AUTHOR]