Alicyclobacillus acidoterrestris is a spore-forming food spoilage bacterium. Its spore is problematic to the juice industry because of its ability to grow in low pH environments and survive pasteurization processes. The purpose of this study was to investigate the effect of the non-thermal technology, high pressure homogenization (HPH) and the antimicrobial compound, dimethyl dicarbonate (DMDC), on inactivation of A. acidoterrestris, in a broth system. Vegetative cells and spores of five strains of A. acidoterrestris (N-1100, N-1108, N-1096, SAC and OS-CAJ) were screened for their sensitivity to HPH (0, 100, 200 and 300 MPa) in Bacilllus acidoterrestris thermophilic (BAT) broth. Strain SAC (most resistant) and OS-CAJ (least resistant) were further tested for their sensitivity to 250 ppm DMDC. This was followed by evaluation of combined effects of HPH and DMDC against strain SAC. Effects of HPHand DMDC treatment combinations (no DMDC, 250 ppm DMDC added 12 h before, 2 h before, immediately before, and immediately after 300 MPa HPH treatment) on spores of SAC over a 24-h period were evaluated. After all treatments, samples were serially diluted and surface plated onto BAT agar, and the populations were determined after incubation at 44 &degC for 48 h. All HPH and DMDC treatments significantly (P<0.05) inhibited growth of vegetative cells, spores were less affected by these treatments. HPH caused a 1-to 2-log reduction in vegetative cell populations at 300 MOa for four strains, but only about 0.5-log reduction of SAC strain. Spores of all five strains were not significantly reduced by HPH. DMDC also slowed growth of vegetative cells significantly. For vegetative cells of SAC and OS-CAJ, 250 ppm DMDC reduced the population by about 2 log whereas spore population was reduced by less than 0.5 log. The addition of DMDC together with HPH slightly enhanced the inactivation effect over a 24-h period as compared with treatment with HPH alone. These results demonstrate that HPH and DMDC show promise for aiding in control of growth of vegetative cells of A. acidoterrestris. However, neither treatment alone or in combination, is very effective against spores.

Optical-electrical, rendering, paper-making, and sewage treatment plants emit odorous waste gases containing dimethyl sulfide (DMS) as one of the major odorous compounds. For the protection of ambient air quality and prevention of odor complaints, DMS should be eliminated from the gases before venting them into the atmosphere. This study aimed to develop a process for eliminating DMS in the waste gases by introducing an enough amount of chlorine gas to oxidize DMS therein to non-odorous dimethyl sulfone (DMSO2). The vented gas from the oxidation step is then contacted with a bed of granular activated carbon (GAC) to convert the residual chlorine to GAC-adsorbed hydrochloric acid and get a nearly odor-free gas. Both lab-scale and field tests were performed in this study. Results from the lab test indicate that the GAC had only an equilibrium DMS adsorption capacity of 4.30 mg/g GAC with 15-30 ppm DMS and no chlorine in the test gas. With an empty-bed gas-GAC contact time (EBCT) of around 0.49 s and no DMS in the test gas, 42 ppm gaseous chlorine could completely be reduced to HCl and the reduction product adsorbed to the GAC. The GAC had a minimum chlorine elimination capacity of around 110 mg/g GAC. Lab tests also indicate that with a molar Cl2/DMS ratio (R) of around 0.9 and a gas-phase reaction time of 5 s, and an EBCT of 0.58 s, the influent 22 ppm DMS could be removed to below detectable limits. Results from field tests in an optical-electrical wastewater plant show that by the developed process, < 1 ppm DMS in the plant¡¦s waste gas could be treated to an odor-free degree with a chlorine dose of 4-10 ppm.

No description available.

Thesis (Ph. D.)--Auburn University, 2006. / Abstract. Vita. Includes bibliographical references.

Oncolytic viruses (OV) are an emerging class of anticancer bio-therapeutics that induce antitumor immunity through selective replication in cancer cells. However, the efficacy of OVs as single agents remains limited. We postulate that resistance to oncolytic virotherapy results in part from the failure of tumor cells to be sufficiently infected. In this study, we provide evidence that in the context of sarcoma, a highly heterogeneous malignancy, the infection of tumors by different oncolytic viruses varies greatly. Similarly, for a given oncolytic virus, productive infection of tumors across patient samples varies by many orders of magnitude. To overcome this issue, we hypothesize that the infection of resistant tumors can be achieved through the use of selected small molecules. Here, we have identified two novel drug classes with the ability to improve the efficacy of OV therapy: fumaric and maleic acid esters (FMAEs) and vanadium compounds. FMAEs are enhancing infection of cancer cells by several oncolytic viruses in cancer cell lines and human tumor biopsies. The ability of FMAEs to enhance viral spread is due to their ability to inhibit type I IFN production and response, which is associated with their ability to block nuclear translocation of transcription factor NF-κB. Vanadium-based phosphatase inhibitors enhance OV infection of RNA viruses in vitro and ex vivo, in resistant cancer cell lines. Mechanistically, this involves subverting the antiviral type I IFN response towards a death-inducing and proinflammatory type II IFN response, leading to improved OV spread, increased bystander killing of cancer cells, and enhanced anti-tumor immune-stimulation. Both FMAEs and vanadium compounds improve therapeutic outcomes of OV treatment in syngeneic tumor models, leading to durable responses, even in models otherwise refractory to OV and drug alone. Overall, we showcased novel avenues for the development of improved immunotherapy strategies.

No description available.

The adhesion of poly(dimethyl siloxane) (PDMS) to silica substrates was measured by 90 degree peel testing of PDMS strips cast on silica substrates. The objective of this work was to investigate the effects of silica surface chemistry on the adhesion between PDMS and silica substrate. Silica substrates with different surface chemistry were prepared by both chemical modification and physical adsorption. Silane coupling agents were used to provide octyl chains and primary amino groups on the silica surfaces. Also silica surfaces were coated with cetyltrimethylammonium bromide (CTAB), polyvinylamine (PVAm) or poly(N-isopropylacrylamide) (PNIPAM) by physical adsorption. The adhesion samples were prepared by casting Sylgard® 184 silicone elastomers on silica surfaces followed by thermal curing. Water contact angle measurements, scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared microscopy (FTIR) were performed to measure the surface properties of the peel test samples. It is believed that hydrogen bonding between siloxane bonds in PDMS and silanol groups on silica substrate contributes to the strong adhesion of PDMS and silica surface. The adhesion forces significantly reduced by the adsorption of PVAm and PNIPAM onto silica surfaces. In addition, the introduction of primary amino groups on silica surface would poison the catalyst during the curing of PDMS, which causes the formation of low crosslinking PDMS in the outer surface and is expected to decline the adhesion force. Lastly, the slightly reduce of adsorbed PVAm (340 kDa) on the silica substrate after peel test is considered to be useful for long-term lubrication. / Thesis / Master of Applied Science (MASc)

Organophosphonates have been used as simulants of highly toxic compounds such as chemical warfare agents in the study of the decomposition reactions that occur on the surface of hafnium dioxide. Metal oxide and metal-oxide nanoparticles have been shown to decompose organophosphonate molecules. In this study, high surface area hafnium oxide nanoparticles are synthesized via laser ablation. This creates nanoparticles that are free of contaminants and have a narrow size distribution. The particles are characterized by atomic force microscopy and scanning electron microscopy to determine particle size and thin film morphology. Once characterized, they are exposed to dimethyl methylphosphonate and the surface reaction is analyzed by reflection-absorption infrared spectroscopy. / Master of Science

The acid which is analogous to the next member of the diphenylpolyenes, 1,4-diphenylbutadiene, is muconic acid. This acid has been chosen to be investigated in an effort to isolate all the stereoisomers of a set containing more than two isomers.

Abstract DMSO (dimethyl sulfoxide) has merits of a high boiling point and high solution power to most photo-resistant materials used in semiconductor and LCD (liquid crystal displayers) industries. Wastewaters originated from the industries contain hundreds of grams of DMSO per cubic mater. DMSO is easily decomposed to DMS (dimethyl sulfide) and DMSO2 (dimethyl sulfone) by microorganisms in biological reactors. Malodorous DMS has a relatively low water solubility and can easily emit into the atmosphere thus causes nuisance problems. The fraction of conversion of DMSO to DMS is possibly related to the volumetric DMSO loading (F/V) to an aerobic wastewater treatment pond. This study aimed to investigate the volumetric DMSO loading which minimize the DMS production. Sequencing batch reaction tests indicate that with F/V of less than 0.45 kg DMSO-S/m3.day, there was no DMS detected in the treating mixed liquor and the vented gas from the liquor. It was also observed that with sulfate-S of higher than 0.55 kg/m3 in the mixed liquor which corresponded to F/V of 0.55 kg DMSO-S/m3.day, a high conversion of DMSO to DMS resulted in the system failure.