Electric surface properties of Delrin used for high voltage insulation.

In this study surface properties of Delrin have been investigated. Delrin is a homopolymer of acetal resin. To study the degradation and the effect of the environment on the surface of this material, samples of Delrin were immersed in saline water with salinities of 0.005-100 mS/cm at 0, 23, 60 and 98 °C. Specimens were also placed in air at these four temperatures. The contact angle of a 4 mu1 sessile droplet of distilled water on the surface of Delrin as a measure of the surface wetability or the hydrophobicity has been measured in this study. Increasing the parameters of temperature, salinity (up to certain level), and the length of time of immersion decreased the contact angle until it reached saturation. The dc and ac breakdown, water absorption and surface roughness of Delrin were also measured and were found to have correlations with the hydrophobicity of Delrin. After the reduction of hydrophobicity had reached saturation, the specimens were removed from the saline solutions. The effects of volume of the droplet of distilled water and the time to measure the contact angle after placing the droplet on the surface were also studied. (Abstract shortened by UMI.)Dept. of Electrical and Computer Engineering. Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis2005 .T35. Source: Masters Abstracts International, Volume: 44-03, page: 1466. Thesis (M.A.Sc.)--University of Windsor (Canada), 2005

Spatial differences in corneal electroretinogram potentials measured in rat with a contact lens electrode array

PURPOSE: It has been known for several decades that the magnitude of the corneal electroretinogram (ERG) varies with position on the eye surface, especially in the presence of focal or asymmetric stimuli or retinal lesions. However, this phenomenon has not been well-characterized using simultaneous measurements at multiple locations on the cornea. This work provides the first characterization of spatial differences in the ERG across the rat cornea. METHODS: A contact lens electrode array was employed to record ERG potentials at 25 corneal locations simultaneously following brief full-field flash stimuli in normally sighted Long-Evans rats. These multi-electrode electroretinogram (meERG) responses were analyzed for spatial differences in a-wave and b-wave amplitudes and implicit times. RESULTS: Spatially distinct ERG potentials could be recorded reliably. Comparing relative amplitudes across the corneal locations suggested a slight non-uniform distribution when using full-field, near-saturating stimuli. Amplitudes of a- and b-waves were approximately 3 % lower in the inferior quadrant than in the superior quadrant of the cornea. CONCLUSIONS: The present results comprise the start of the first normative meERG database for rat eyes and provide a basis for comparison of results from eyes with functional deficit. Robust measures of spatial differences in corneal potentials will also support optimization and validation of computational source models of the ERG. To fully utilize the information contained in the meERG data, a detailed understanding of the roles of the many determinants of local corneal potentials will eventually be required

Overall Survival and Functional Results of Prostate-Sparing Cystectomy

Purpose: To compare two matched groups of men with bladder transitional cell carcinoma (TCC) who underwent prostate-sparing cystectomy (PSC) or conventional radical cystoprostatectomy (CRC). Materials and Methods: Twenty-three men who have undergone PSC with the diagnosis of EODGGHU�7&&��7D±7���IURP������WR������LQ�7HKUDQ��,UDQ�ZHUH�LQFOXGHG�LQ�WKH�VWXG\�DV�WKH�H[- perimental group. The control group composed of 27 men with comparable tumor characteristics and age range, who had non-nerve-sparing radical cystoprostatectomy and orthotopic ileal W pouch reconstruction in the same center. All the procedures were performed by the same surgical group under the supervision of different attending staff. Results: Mean follow-up period was 39 months in PSC and 35 months in CRC group. The 5-year overall survival was 47% and 30% in PSC and CRC groups, respectively. Median survival was 48 months in PSC and 36 months in CRC group, using Kaplan-Meier survival analysis (P > .05). Impotence was observed in 16.6% in PSC and in 83.3% in CRC group (P� ��������0HDQ�,QWHUQDWLRQDO�,QGH[�RI�(UHFWLOH�)XQFWLRQ���VFRUH�RI�WKH�36&�JURXS�ZDV� 19.8 compared with 5.7 in the CRC group (P = .003). Only one patient in each group was completely incontinent. Urethral anastomosis stricture occurred in 2 patients in CRC group. Conclusion: Patients who underwent PSC did not show decreased overall survival compared to CRC, which provided better functional results. Keywords: urinary bladder neoplasms, transitional cell carcinoma, cystectomy, male, prognosis, adverse effect

A novel antifungal property for the Bacillus licheniformis ComX pheromone and its possible role in inter-kingdom cross-talk

Quorum sensing molecules (QSMs) regulate, through a chemical communication process, multiple complex systems in bacterial and some fungal populations on the basis of cell density. The bacterial QSMs involved in inter-kingdom cross-talk may exhibit antagonistic activity against fungi. This provides an important opportunity for biocontrol of fungal invasion in plants. It has been shown that cultures of Bacillus spp. inhibit fungal growth. Here, we explore the inhibitory potential of the industrial workhorse Bacillus licheniformis NCIMB-8874 and its QSM (ComX pheromone) on the growth of Aspergillus flavus, a cereal, legume, and nut crop pathogen. Our studies show that ComX filtered extracts from cultures of B. licheniformis can cause a significant reduction in the growth of A. flavus NRRL 3357 and ESP 15 at a concentration as low as 13 μg ml−1. This work evidences, for the first time, the inter-kingdom utility of the bacterial quorum sensing ComX pheromone indicating potential antifungal food security against A. flavus