Polyoxovanadate fabricated gold nanoparticles: Application in SERS.

This article reports a surface modification of gold nanoparticles with water soluble polyoxometalate, V10O286- (decavanadate, V10). Two sizes of citrate-capped gold nanoparticles AuNP-Citrate-S (∼11nm) and AuNP-Citrate-L (∼46nm) were modified with V10 in aqueous media to form AuNP-V10-S and AuNP-V10-L, respectively. Both AuNP-V10-S and AuNP-V10-L were found to be significantly better than their citrate counterparts in strengthening Raman vibrational signals of analyte molecule. All the nanoparticles were characterized by UV-visible and Fourier transform infrared (FTIR) spectroscopies, dynamic light scattering (DLS), transmission electron microscopy (TEM) and energy dispersive X-ray (EDX) line analysis. We demonstrate that AuNP-V10-L is excellent surface-enhanced Raman scattering (SERS) substrate for a Raman-active analyte molecule at nanomolar concentrations.

Development of a fluorescence based flux sensor for thin film growth and nanoparticle deposition.

An optical flux sensor, based on the fluorescence properties of materials and nanoparticles, has been developed to control the deposition rate in thin film deposition systems. Using a simple diode laser and a photomultiplier tube with a light filter, we report the detection of gallium atoms and CdSe-ZnS quantum dots. This setup has a high sensitivity and reproducibility.

The role of incentive design, incentive value, communications strategy, and worksite culture on health risk assessment participation.

PURPOSE: To examine the impact of financial incentives, communications strategy, and worksite culture on health risk assessment (HRA) participation rates. DESIGN: A cross-sectional study design was used to examine factors that influence employee participation, including incentive value, incentive design, communications strategy, and worksite culture. SETTING: Large private-sector and public-sector employers. PARTICIPANTS: Thirty-six employers (n = 559,988 employees) that provided financial incentives to promote employee HRA participation. INTERVENTION: Organizations implemented the HRA as part of a more comprehensive worksite health promotion strategy that included follow-up interventions and a variety of other components. The primary outcome of interest was employee HRA participation. MEASURES: Information on program design and structure, as well as on HRA eligibility and participation, was collected for each organization via standard client report and semistructured interviews with account managers. General linear regression models were used to examine the extent to which factors influence HRA participation independently and when controlled for other factors. RESULTS: Incentive value (r2 = .433; p < .000), benefits-integrated incentive design (r2 = .184; p = .009), culture (r2 = .113; p = .045), and communications strategy (r = .300; p = .001) had positive bivariate associations with HRA participation rates. When all factors were included in the model, incentive value (p = .001) and communications strategy (p = .023) were significantly associated with HRA participation. Variance accounted for by all factors combined was R12 = .584. CONCLUSION: This study suggests that incentive value, incentive type, supportive worksite culture, and comprehensive communications strategy may all play a role in increasing HRA participation.

Abundant transcripts of malting barley identified by serial analysis of gene expression (SAGE).

Serial analysis of gene expression (SAGE) was applied to the major cereal crop barley (Hordeum vulgare) to characterize the transcriptional profile of grain during the malting process. Seven SAGE libraries were generated from seed at different time points during malting, in addition to one library from dry mature seed. A total of 155,206 LongSAGE tags, representing 41,909 unique sequences, was generated. This study reports an in-depth analysis of the most abundant transcripts from each of eight specific time points in a malting barley time course. The 100 most abundant tags from each library were analysed to identify the putative functional role of highly abundant transcripts. The largest functional groups included transcripts coding for stress response and cell defence, ribosomal proteins and storage proteins. The most abundant tag represented B22EL8, a barley metallothionein, which showed significant up-regulation across the malting time course. Considerable changes in the abundance profiles of some of the highly abundant tags occurred at 24 h post-steeping, indicating that it may be an important time point for gene expression changes associated with barley seed germination.

Genes associated with the end of dormancy in grapes.

A grape bud EST library was constructed and 4270 ESTs sequenced. The library clones were arrayed for the purpose of investigating the level of gene expression over time, particularly leading up to the buds' release from dormancy. The arrays were hybridized with P(33)-labeled probes produced from samples of buds collected at weekly intervals. These probes covered the time from 9 weeks prior to bud burst until just after the emergence of the shoots. Expression patterns from these genes have been examined. It was found that 74% of the genes in the data set were homologous to known proteins. Genes were then assigned to functional categories according to their primary BLAST match. Of these 13% were involved with photosynthesis, 13% with disease resistance and defense, 5% energy, 12% metabolism, 20% protein production and processing, 25% cell structure and plant growth and the remaining 12% were unclassified The expression pattern of a selection of "candidate" genes retrieved from literature previously reporting an association with dormancy changes was assessed. On closer examination most of these genes relate to the oxidative processes and stress responses within the cell. The results of this study show that even in the dormant state, gene expression in the buds is high.

Single-nucleotide polymorphism detection in plants using a single-stranded pyrosequencing protocol with a universal biotinylated primer.

Analysis of variations in plant genomes is increasingly focused on single-nucleotide polymorphism (SNP) analysis, increasing the need for fast yet reliable, simple, and cost-effective techniques to handle the large number of these polymorphisms within large plant genomes. Pyrosequencing technology offers a technique that takes advantage of the interaction of four enzymes in a single-tube assay to measure DNA synthesis in real time. Pyrosequencing provides a DNA sequence and an advantage over alternative techniques in poorly characterized genomes such as those of most plant species. Here we compare the use of both single-stranded and double-stranded template Pyrosequencing on plant tissue for SNP identification. Different enzymatic strategies for double-stranded template preparation were compared. Preparation of double-stranded template from plant tissue required labor-intensive purification to allow double-stranded Pyrosequencing. A more cost-effective and less labor-intensive alternative to double-stranded template preparation in plants has been developed using a universal biotinylated primer to improve the efficiency of single-stranded Pyrosequencing. This provides an efficient high-throughput method for SNP analysis by Pyrosequencing.