We have synthesized a new poly(imide) precursor for solution electrodeposition onto conducting surfaces. The new monomer, N,N‘-bis[p-phenylamino(phenyl)]-1,4,5,8-naphthalenetetracarboxylic diimide (DNTD), contains a central naphthalene diimide moiety flanked by two dimerizable diphenylamine groups. DNTD was oxidatively electrodeposited onto Au-, Pt-, and In-doped SnO2 surfaces from DMSO, CH3CN, and CH2Cl2. The cyclic voltammetry is consistent with initial radical cation formation of diphenylamine groups, and then para C−C coupling of radicals to form dimers and higher order oligomers. IR spectroscopy was used to determine the average degree of polymerization and confirm para coupling. The resulting material shows electrochemically reversible 1e-/ and 2e-/monomer unit reduction waves corresponding to the naphthalene tetracarboxylic diimide radical anion and dianion. Also a quasireversible 1e-/ and 2e-/monomer unit oxidation corresponding to the oxidation of diphenylbenzidine unit is shown. Visible−NIR spectroelectrochemistry shows low-energy absorptions in the NIR (∼1100 nm) corresponding to diphenylbenzidine radical cation π-dimer in CH2Cl2 whereas in DMSO and CH3CN at the same potential, no low-energy bands are observed. Variable-angle transmission spectroscopy on air-oxidized dry films prepared from CH2Cl2 shows band shifts from 1100 to 950 nm and almost no shift of the 845 nm band of films formed in DMSO. This is consistent with the anisotropic nature of the material from CH2Cl2. We interpret these spectra as arising from π-stacks parallel to the surface. Scanning electron micrographs show small domains (∼300−500 nm) for films composed mostly of dimers and smooth films for relatively higher molecular weight materials.

Poultry processing plants in the United States were surveyed on their current Campylobacter and Salmonella control practices. Following surveys, data were collected to develop a baseline for prevalence rates of Salmonella and Campylobacter; then changes in practices were implemented and evaluated for improvements in pathogen control. Surveys were sent to the plant Quality Assurance managers to determine production levels, antimicrobial interventions, and current pathogen testing practices. Initial sampling was performed at 6 plants with similar production volumes, at sites that included carcass samples before any pre-evisceration intervention, after exiting the inside-outside bird washer (IOBW), after exiting the pre-chiller, after exiting the primary chiller, and after exiting any post-chill intervention, as well as a water sample from each scalder, pre-chiller, primary chiller, and post-chill dip tank or finishing chiller. Enumerations and enrichments were performed for Campylobacter and Salmonella. Following the baseline sampling, changes in practices were suggested for each plant and a second sampling was conducted to determine their effectiveness. Results demonstrated that peracetic acid (PAA) was the most effective (P < 0.05) antimicrobial currently in use. The use of a post-chill antimicrobial immersion tank and/or use of a cetylpyridinium chloride (CPC) spray cabinet also displayed a further reduction in microbial levels (P < 0.05) when the primary chiller was not sufficient (P > 0.05). Microbial buildup in the immersion tanks demonstrates the need for effective cleaning, sanitation practices, and chiller maintenance to reduce contamination of poultry with Campylobacter and Salmonella.

The developed CRISPR-Cas9-based genome engineering tool will facilitate functional genomic studies in C. difficile as well as the elucidation of mechanisms related to host-bacteria interaction and pathogenesis of CDI. This will be highly beneficial for the development of innovative strategies for CDI diagnostics and therapies.

The strain rate dependence of freestanding, nanocrystalline gold films was evaluated by a microtensile technique with applied strain rates on the order of 10−4 to 10−6 s−1. Film thickness ranged from 0.25 to 1.00 μm with corresponding grain sizes of 40 to 100 nm. The plastic properties were found to be particularly sensitive to strain rate, film thickness, and grain size, while the elastic property remained relatively unchanged. The thinner films exhibited significant strain rate sensitivity, while the thicker film exhibited only marginal changes. Hall–Petch boundary hardening was observed and dominated plastic flow at larger strain rates, while diffusion-controlled deformation mechanisms appeared to be activated with increasing influence as strain rate decreased. Analysis of dislocation-based and grain-boundary diffusion-related creep suggested that the films were likely experiencing power-law creep as the dominant deformation mechanism in this grain size regime at lower strain rates.

Aims: The objectives of this study were to investigate the correlations between Shiga toxin-producing Escherichia coli (STEC) shedding and faecal microflora in beef cattle and to identify functional species that might be used for STEC control. Methods and Results: Faecal samples were collected from 110 calves and 92 dams. The number and prevalence of STEC were determined using CHROMagar TM STEC; denaturing gradient gel electrophoresis (DGGE) was employed to analyse faecal bacterial composition. Six-month-old calves had the highest STEC shedding levels (3Á03 AE 1Á41 Log CFU g À1 ) and prevalence (95Á5%). Both the number and prevalence decreased significantly as the calf age increased (P < 0Á05). The DGGE analysis showed that faecal bacterial diversity increased, while cattle ages increased and STEC shedding levels decreased. Significant correlations between STEC shedding, cattle age and bacterial compositions were observed by redundancy analysis (P < 0Á05). T-value biplots and sequencing results indicated that butyrate-producing bacteria (BPB) negatively correlated with STEC shedding. Conclusions: Higher STEC shedding levels and prevalence were associated with younger cattle age, lower faecal bacterial diversity and lower BPB levels. Significance and Impact of the Study: Butyrate-producing bacteria in GI tract might serve as an option for the future development of STEC shedding control strategy.