ATRC PROCESSES AND ARCHITECTURES AS TOOLS FOR ADVANCING THE COMPLEXITY OF SINGLE-CHAIN POLYMERIC NANOPARTICLES

Atom transfer radical coupling (ATRC) is gaining recognition for its utility in building complex polymeric architectures because it features efficiency, a wide range of compatible substrates, and a lack of byproducts. These qualities are especially desirable in applications requiring intramolecular cross-linking as in the synthesis single-chain nanoparticles (SCNP). This dissertation aims to (I) provide motivation and context for developing ATRC technology for intramolecular cross-linking, (II) provide guidance into the impact of catalyst selection and substrate on reaction efficiency and morphology, and (III) demonstrate the possibility to sequence intrachain ATRC with ATRP to create advanced SCNP architectures. Chapter II describes the preparation of SCNP from parent polymers containing alkyl or benzyl bromide ester pendants using ATRC catalyzed by copper halides complexes. Tri- or tetradentate alkyl or pyridyl amines (PMDETA, TPEN, and TPMA), which tune the redox potential of the Cu(I)/Cu(II) system, were directly compared. Coupling efficiency was positively correlated with the kATRP of the respective catalyst systems. However, PMDETA complexes afforded greater control as evidenced by lower polydispersity. In the case of alkyl halide pendants, selectivity for coupling over disproportionation systematically decreased under conditions designed to increase the concentration of CuI/L. Polymers with benzyl bromide pendants, which cannot disproportionate, tended to produce high molecular weight products, even in ultradilute solutions (0.25 –1.0 mg/mL). Chapter III describes the preparation of SCNP from parent polymers capable of initiating intra-chain polymerization by ATRP under conditions favoring termination by coupling. Because of the wide variety of compatible monomers that have been well-established for ATRP systems, the ATRP/C framework both simplifies reaction procedures (one pot polymerization and coupling strategies are feasible) and imparts handles with which to control both architecture and functionality. To demonstrate this potential, model simple brushes and hyperbranched examples were prepared. SCNP with the hyperbranched motif were remarkably dense, a result which demonstrates the potential to facilitate more globular SCNP structures using modifications of intrachain polymerizations. Methacrylic brush arms, which are not non-ATRC active, could be induced to couple by adding 5 equivalents of styrene under the shared ATRP/C conditions. In addition, it was determined that hyperbranched SCNP retain “living” ω-ends which may be initiated to perform post-collapse polymerizations. A model styrene example is presented; despite occurring in an ultradilute solution, the polymerization maintains fidelity to pseudo-first order kinetics. In sum, there is currently a great impetus for pushing the boundaries of structural and functional complexity that can be designed using the single-chain nanoparticle motif. Atom transfer radical chemistry is a particularly versatile example and it is my hope that this work facilitates the creation of new creative and functional designs

An analysis of the methods used by John William De Forest in translating his personal war experiences into realistic fiction as shown in Miss Ravenel\u27s conversion.

During the last half of the nineteenth century, novels, short stories, articles and poems written by John William De Forest appeared in the pages of such popular magazines as Harper\u27s, The Atlantic Monthly, and The Galaxy, along with literary contributions from Mark Twain, Whittier, Longfellow. Henry James. and William Dean Howells. De Forest, however, has been forgotten by both the reading public and the literary historians since that time, while the literary reputations of the other men have increased; yet it is to this obscure writer that modern critics such as Carl Van Doren, Alexander Cowie, Arthur Quinn. and Van Wyck Brooks have turned in attempting to trace the growth of realism in the American novel. De Forest, born in 1826 and privately educated, travelled widely throughout Europe and the Near East, returning to his native Connecticut to record his experiences in two travel books. Besides these two books he had written prior to the Civil War two novels and a history of the Indians of his state. Unlike the other writers of this period, De Forest took an active part in the war. serving as a captain in the Union army for three years and an officer of the Freedmen\u27s Bureau in South Carolina for three more. He recorded his military experiences and impressions in the letters which he wrote to his wife and to other members of his family with the intention of collecting these letters and papers later and publishing them. He also found time to write articles describing his experiences which were published in the various literary magazines of the day

Indwelling Bowel Management System as a Cause of Life-Threatening Rectal Bleeding

A 79-year-old male was transferred to the intensive care unit for postoperative respiratory support. An indwelling bowel management system was inserted for containment of noninfective diarrhoea. Following only 11 days of continual use the patient developed life-threatening rectal bleeding. Preoperative normal rectal mucosa and anatomy were documented. There was no evidence of postoperative coagulopathy. Mesenteric angiography identified bleeding from a branch of the superior rectal artery. Rectal mucosa pressure necrosis secondary to the indwelling Flexi-Seal® Fecal Management System was diagnosed. The patient required an 11-unit transfusion of packed red cells. Following intraarterial coil embolization of the superior rectal artery the bleeding abated. Indwelling bowel management systems are commonly used in immobile and critically ill patients with diarrhoea or faecal incontinence. This is the first report of this important complication in the literature

Analysis of novel biomarkers in the pathobiology of prostate cancer

The process of developing a greater understanding of the fundamental molecular mechanisms involved in prostate carcinogenesis will provide insights into the questions that still plague the field of prostate cancer research. The goal of this study was to identify altered genes that may have utility either as biomarkers, for improved diagnostic or prognostic application, or as novel targets important in the pathobiology of prostate cancer. We hypothesize that an improved understanding of the genomic and proteomic alterations associated with prostate cancer will facilitate the identification of novel biomarkers and molecular pathways critical to prostate carcinogenesis. In order to enhance our knowledge of the molecular alterations associated with prostate cancer, our laboratory performed microarray analysis comparing gene expression in healthy normal prostate to that in prostate cancer tissue. Of the greater than 400 genes with significantly altered expression identified in our study, MT2A, Tacc2, Nell2, FosB, PCP4, and Cyr61 were selected for further evaluation to confirm expression changes and evaluate their potential impact in prostate cancer. Analysis of MT2A, Tacc2, and Nell2 expression patterns failed to demonstrate significant changes between prostate cancer and donor prostate tissue and, therefore, these results do not support their further development as prostate cancer biomarkers. We demonstrated that PCP4 was expressed predominently in the stromal compartment of the prostate and was expressed at similar levels in the stroma of normal and prostate cancer tissue. Interestingly, protein expression of PCP4 in a panel of colon cancer tissues was dramatically higher in adenoma and adenocarcinoma tissues compared to donor and benign colon tissue and, consequently, we feel that PCP4 has more potential as a biomarker in colon cancer than in prostate cancer. We also demonstrated that FosB and Cyr61 were upregulated in prostate cancer tissues over donor prostate tissues. Based on expression analysis of FosB and expression and functional analysis of Cyr61, we believe that these two targets have the greatest potental to be functionally significant in the etiology of prostate cancer

Environmental Issues of Livestock Production in Developing Countries: Need for Government Intervention Using the Truck Based Approach

Globally, the natural environment faces a range of unprecedented challenges which are require a well-structured strategic approach in solving it. One of these challenges is the ever-increasing greenhouse gas emission. Currently majority of our daily activities directly or indirectly contributes to greenhouse gas emission. An effort was taken to understand better the principal function of livestock production in the pollution of the natural environment and to ascertain mitigation policies to curb the effects on human life.Theories such as the Enforcement Strategic Theory, Utilitarian Commitment Theory, Deterrence Theory, and the Social factors Commitment Based theory were used in this study. Already processed statistics, policy strategies, laws in economics as well as authors intuitive proposals and ideas were used in this study. It was ascertained that population growth, fluctuating economies, food preferences, and urbanization had imposed pressure on livestock production and the agricultural sector, thereby leading to the release of odor, ammonia, pathogens, excess phosphorus and nitrogen harming the natural environment and also contribute to greenhouse gas emission. A more significant proportion of the growth in crop production is anticipated because of a rise in the demand for livestock feed. It was found that most livestock farmers do not have a well-regulated operation in most developing countries. To reduce or eliminate these effects, the “truck-based approach” was therefore propounded and proposed to enhance the smooth movement of the livestock droppings to either the crop farm or to the processing house or to the storage room to reduce or prevent unnecessary dumping. Keywords: Livestock Production, Environmental Issues, Green House Gas, Truck Based Approach, Government Regulation, and Developing Countries. DOI: 10.7176/JBAH/10-22-04 Publication date: November 30th 202

GIS Use in Oral Rabies Vaccine Programs

Frequent human and domestic animal exposures to rabid wildlife have raised the public\u27s awareness, leading to an increase in the number of wildlife submissions for rabies testing as well as an increase in the number of people requiring post exposure prophylaxis treatment. During 1998 and 1999, the Health and Human Services Department of a densely populated urban/suburban county in Virginia received a total of 955 animal submissions for rabies testing. Wildlife accounted for 714 of the submissions. Seventy-nine of the submitted wildlife were found dead, 445 were killed or euthanized for testing (190 unknown). Of the wildlife submissions,152 (21%) were positive, including 100 of 178 raccoons submitted. Human exposure, potentially requiring post-exposure prophylaxis, was recorded in 22 positive and 334 negative rabies submissions. Information was not available for 9 positive and 135 negative submissions; human exposure did not occur with the remaining submissions. To reduce the public\u27s risk of exposure to rabid animals, the County is developing a program to distribute oral rabies vaccine to raccoons. To increase the precision of vaccine delivery to raccoons, we propose the use of geographical information systems (GIS) as a method for selecting vaccination sites. Results from trapping and tracking studies, along with hydrographic and vegetation data, were utilized in the development of GIS generated vaccine distribution maps. Also factored in was human activity, commerce, residential housing density, competition by companion animals for vaccine bait, the location of refuse facilities, and property ownership. It is expected that this GIS supported approach will improve the efficiency of the program by lessening the cost while increasing the number of raccoons immunized. The resulting decrease in the incidence of rabies will lead to fewer human exposures to rabid wildlife, a decrease in the number of healthy wildlife euthanized for testing, and a decrease in the number of people requiring post-exposure prophylaxis treatment