Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1992. / Vita. Abstract. Includes bibliographical references (leaves 110-114). Also available via the Internet.

Thesis (Ph. D.)--University of Washington, 2001. / Vita. Includes bibliographical references (leaves 64-69).

This thesis presents the results of a study on the blends of an aliphatic crystallizable polyamide (nylon 6/6) and trace quantities of a polar non-crystallizable diluent (poly(vinylpyrrolidone)). This study is based on the preliminary findings of Keith et al. who reported striking morphological changes in nylon 6/6 upon addition of small amounts of poly(vinylpyrrolidone) (PVP). The melting behavior of pure nylon 6/6 was also studied during the course of this investigation. The melting behavior of nylon 6/6 was studied using a differential scanning calorimeter (DSC). Samples were isothermally crystallized at various temperatures from the melt. Subsequent DSC analysis showed the presence of three distinct melting endotherms. The behavior of these three endotherms was studied as a function of the crystallization temperature (T_C), annealing time, and DSC heating rate. X-ray studies (small and wide angle) and hot stage optical microscopy studies were also carried out to determine the cause of the multiple endotherms. The influence of addition of PVP on the crystal morphology of nylon 6/6 was studied using DSC, x-ray and hot stage photomicroscopy. The addition of PVP has a dramatic effect on the spherulitic morphology of nylon. The addition of PVP to nylon caused a striking reduction in the nucleation density of spherulites, modification of lamellar organization in spherulites (as evidenced by the occurrence of banding), and modification of interlamellar spacings. / Master of Science

Thesis (M.S.)--University of Wisconsin--Madison, 1981. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 45-49).

Orientador: José Benedito Oliveira Amorim / Banca: Maria Aparecida Neves Jardini / Banca: Luciene Cristina de Figueiredo / Resumo: O objetivo desse estudo foi avaliar o efeito do iodo-povidine (10%), irrigado subgengivalmente, como adjunto ao tratamento mecânico periodontal convencional (raspagem e alisamento radicular). Foram selecionados 29 indivíduos portadores de periodontite crônica, divididos aleatoriamente em dois grupos; Grupo Controle (RAR) - constituído de 15 pacientes que receberam tratamento periodontal manual e posterior irrigação com solução fisiológica (NaCl 0,9%) e; Grupo Experimental (RAR-I) - Constituído de 14 pacientes que receberam tratamento periodontal convencional e posterior irrigação com iodo-povidine (PVP-I 10%). Foram avaliados parâmetros clínicos (Índice Gengival (IG), Índice de Placa (IP), Sangramento à sondagem (SS), Supuração (Sup), Profundidade de Sondagem (PS), Nível de Inserção Clínico (NIC) e microbiológicos (método checkerboard DNA-DNA hybridization), no início e após 30 e 90 dias do tratamento periodontal. Observamos a melhora em todas as variáveis clínicas, pós-tratamento convencional, quando comparados aos dados iniciais da doença periodontal (p<0,05). A adição de iodo-povidine não mostrou ganho terapêutico significativo na maioria dos parâmetros clínicos utilizados quando comparados aos valores obtidos do Grupo Controle. Os resultados microbiológicos indicam que ambas as terapias reduziram a contagem e proporção dos patógenos periodontais, sendo que, aos 30 dias, o Grupo RAR-I exibiu maior redução na proporção do complexo vermelho (38%) comparado com o Grupo RAR (20%). Entretanto, aos 90 dias, não foram observadas diferenças significantes estatisticamente entre os grupos. Dessa forma, conclui-se que a adição do PVP-I como agente de irrigação subgengival não trouxe benefícios adicionais ao tratamento da periodontite crônica. / Abstract: The aim of the study was to evaluate the effect of povidone-iodine (10%), irrigated subgingivally as adjunct to periodontal mechanical treatment (scaling and root planning). We used 29 individuals with chronic periodontitis, randomly divided into two groups; Control Group (RAR) - consisting of 15 patients who received conventional periodontal treatment and later irrigation with saline solution (NaCl 0,9%) and; Experimental Group (RAR-I) - Consisting of 14 patients who received conventional periodontal treatment and later with irrigation-povidone-iodine (PVP-I 10%). We evaluated clinical parameters (Gingival Index (IG), Plaque Index (IP), Bleeding on Probing (SS), Suppuration (Sup), Probing depth (PS), Clinical Attachment Level (NCI) and Microbiological (method checkerboard DNA - DNA hybridization) at the beginning and after 30 and 90 days of periodontal treatment. Noticed the improvement in all clinical variables, post-conventional treatment, as compared to the initial data of periodontal disease (p <0.05). Even the addition of PVP-I did not showed significant therapeutic gain in most clinical parameters used when compared to levels obtained from the control group. The microbiological results indicate that both therapies reduced the proportion of counting and periodontal pathogens, and, at 30 days, the RAR-I Group showed further reduction in the proportion of the red complex (38%) compared with the RAR group (20%). Meanwhile, the 90 days, no statistically significant differences were found between the groups. Thus it appears that the addition of PVP-I as an agent of subgingival irrigation has not brought additional benefits in the treatment of chronic periodontitis. / Mestre

Orientadores: Antonio Wilson Sallum, Marcio Zaffalon Casati / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-04T05:21:56Z (GMT). No. of bitstreams: 1 Santos_SauloCabraldos_M.pdf: 822959 bytes, checksum: 370e71f36185b35afcdc9297b0e1d6bc (MD5) Previous issue date: 2005 / Resumo: O objetivo deste trabalho foi avaliar os níveis de compostos sulfurados voláteis (CSV¿s) após a descontaminação das mucosas orais com uma solução aquosa de iodo povidine a 10%. Concluíram o estudo 22 pacientes com doença periodontal crônica, apresentando no mínimo 6 bolsas periodontais (³ 5mm). Os pacientes foram divididos em 2 (dois) grupos, cada um com 13 pacientes aleatoriamente selecionados: Grupo 01 (Controle) e o Grupo 02 (Teste). Os CSV¿s foram medidos utilizando-se um monitor portátil de sulfetos (Halimeterâ). As regiões determinadas para a medição dos CSV¿s foram as seguintes: a) Narina direita; b) Narina esquerda; c) Entrada da boca; d) Dorso posterior da língua; e) Ar metabólico (dos pulmões). A desinfecção das mucosas orais foi executada usando-se um swab estéril saturado com água destilada para o grupo 01 ou iodo-povidine a 10% para o grupo 02. Foram executadas medições iniciais e, repetidas após o uso da substância, no período de 1 hora, 2, 10 e 20 dias após. Os resultados mostraram uma diminuição estatisticamente significante (p<0.05) nos níveis de CSV¿s do grupo teste (iodo) na medição de 1 hora, nas regiões da entrada da boca e dorso posterior da língua, quando comparados com a mesma região do grupo controle. As demais regiões não apresentaram nenhuma alteração. Concluiu-se que o uso tópico de iodo-povidine a 10% nas mucosas orais diminui temporariamente a produção dos CSV¿s quando medidos com um monitor portátil de sulfetos, nas regiões da entrada da boca e dorso posterior da língua, independentemente do tratamento periodontal ter sido realizado / Abstracts: The aim of this study was to evaluate the volatile sulphur compounds level (VSC) after oral mucous disinfection with 10% iodine-povidone aqueous solution. The study involved 26 patients with chronic periodontitis presenting a minimum of 6 periodontal pockets (³ 5mm). Patients were randomly assigned in two groups, each one with 13 patients: Group one (placebo-control) and Group two (iodine-test). Specific regions for VSC level measurements were: A) Nostril right; B) Nostril left; C) Mouth entrance; D) Tongue posterior dorsum; E) Metabolic air (lung air). The measurements were carried out with portable sulfide monitor (Halimeterâ). The oral mucous disinfections were performed using a sterile swab saturated with distilled water for group one or 10% iodine-povidone for group two. Prior application of substances, initial VSC measurements were taken. After application, the measurements were repeated 1 hour, 2, 10 and 20 days. The results showed a statistically significant decrease (p<0.05) for VSC level measurements in mouth entrance and tongue posterior dorsum after 1 hour to test group. The others assessed regions do not presented significant differences. It was concluded that the topic use of 10% iodine-povidone in the oral mucous temporarily decrease the VSC levels in mouth entrance and tongue posterior dorsum, independently of the periodontal treatment execution / Mestrado / Periodontia / Mestre em Clínica Odontológica

The advent of advanced modern nanotechnology techniques offers new and exciting opportunities to develop novel nanotech-derived antimalarial nanodrugs with enhanced selective and targeting abilities that allow for lower effective drug dosages, longer drug persistence and reduced drug degradation within the body. Using a nanodrug approach also has the advantage of avoiding drug resistance problems that plague reconfigured versions of already-existing antimalarial drugs. In this study recombinant triosephosphate isomerase enzymes from Plasmodium falciparum (PfTIM) and Humans (hTIM) were recombinantly expressed, purified and characterised. PfTIM was shown to have optimal pH stability at pH 5.0-5.5 and thermal stability at 25°C with Km 4.34 mM and Vmax 0.876 μmol.ml⁻ₑmin⁻ₑ. For hTIM, these parameters were as follows: pH optima of 6.5-7.0; temperature optima of 30°C, with Km 2.27 mM and Vmax 0.714 μmol.ml⁻ₑmin⁻ₑ. Recombinant TIM enzymes were subjected to inhibition studies using polyvinylpyrrolidone (PVP) stabilised silver nanoparticles (AgNPs) of 4-12 nm in diameter. These studies showed that the AgNPs were able to selectively inhibit PfTIM over hTIM with an 8-fold greater decrease in enzymatic efficiency (Kcat/Km) observed for PfTIM, as compared to hTIM, for kinetics tests done using 0.06 μM of AgNPs. Complete inhibition of PfTIM under optimal conditions was achieved using 0.25 μM AgNPs after 45 minutes while hTIM maintained approximately 31% of its activity at this AgNP concentration. The above results indicate that selective enzymatic targeting of the important, key metabolic enzyme TIM, can be achieved using nanotechnology-derived nanodrugs. It was demonstrated that the key structural differences, between the two enzyme variants, were significant enough to create unique characteristics for each TIM variant, thereby allowing for selective enzyme targeting using AgNPs. If these AgNPs could be coupled with a nanotechnology-derived, targeted localization mechanism – possibly using apoferritin to deliver the AgNPs to infected erythrocytes (Burns and Pollock, 2008) – then such an approach could offer new opportunities for the development of viable antimalarial nanodrugs. For this to be achieved further research into several key areas will be required, including nanoparticle toxicity, drug localization and testing the lethality of the system on live parasite cultures.

Objectives: Molecular iodine released from povidone-iodine formulations significantly enhances periodontal probing depth reductions when applied into human periodontitis sites during mechanical root debridement, largely due to its antimicrobial activity against periodontal bacterial pathogens. Since molecular iodine accounts for the antimicrobial effects of povidone-iodine, new commercial mouthrinses with higher levels of free molecular iodine may also exert antimicrobial properties against periodontal bacterial pathogens. To evaluate this issue, the purpose of this study was to measure and compare the in vitro bactericidal effects of two molecular iodine-based mouthrinses against subgingival biofilm samples from adults with severe periodontitis, and against a fresh clinical subgingival isolate of the periodontal pathogen, Prevotella nigrescens. Methods: Paper point subgingival biofilm samples from 32 adults with severeperiodontitis, and a clinical subgingival isolate identified as P. nigrescens, were secondarily used in this study after their initial microbiological analysis at the Oral Microbiology Testing Service Laboratory at Temple University School of Dentistry. In a subgingival biofilm eradication assay, dilution aliquots from each subgingival biofilm specimen were mixed for a 60-second in vitro contact time with either Iorinse(R) RTU mouthrinse (containing 100 ppm molecular iodine) or iClean(R) mouthrinse (containing 150 ppm molecular iodine), and then neutralized with 3% sodium thiosulfate. The mixtures were then inoculated onto enriched Brucella blood agar culture plates, and incubated anaerobically for 7 days at 37 °C. Bacterial species growing subsequent to a 60-second mouthrinse contact time were considered to be resistant to that mouthrinse. Total viable counts in mouthrinse-exposed subgingival specimens were quantitated, and established phenotypic criteria employed to identify the following red/orange complex periodontal pathogens: Porphyromonas gingivalis, Tannerella forsythia, Prevotella intermedia/nigrescens, Parvimonas micra, Campylobacter rectus, and Fusobacterium nucleatum group species. Subgingival sample dilution aliquots not exposed to the mouthrinses were similarly processed as controls for comparison with mouthrinse-exposed specimens, and were additionally inoculated onto enriched Brucella blood agar plates supplemented with either metronidazole at 16 mg/L, doxycycline at 4 mg/L, amoxicillin at 8 mg/L, or clindamycin at 4 mg/L, which represent recognized non-susceptible drug breakpoint concentrations for each of the antibiotics, followed by anaerobic incubation for 7 days at 37 ºC. In vitro antibiotic resistance was noted when any of the evaluated red/orange complex periodontal pathogens displayed growth on one or more of the antibiotic supplemented enriched Brucella blood agar plates. Nonparametric Wilcoxon signed-rank test analysis compared mean total subgingival viable counts, and mean total subgingival counts of the evaluated red/orange complex periodontal pathogens per patient, between subgingival biofilm samples exposed and not exposed in vitro to the molecular iodine mouthrinses, with a P-value of < 0.05 required for statistical significance. For in vitro susceptibility testing of the P. nigrescens subgingival isolate, aliquots of a 0.5 McFarland standard P. nigrescens cell suspension were mixed with each of the two molecular iodine mouthrinses, as well as with 10% and 0.1% solutions of povidone-iodine, and neutralized with sodium thiosulfate after a 60-second in vitro contact time. The mixtures were then plated onto enriched Brucella blood agar culture plates, and incubated in an anaerobic atmosphere for 7 days at 37 ºC, with total viable P. nigrescens counts on test solution-exposed plates compared to counts non-exposed P. nigrescens control plates. Results: Subgingival biofilms exposed in vitro to either the Iorinse(R) RTU oriClean(R) mouthrinses yielded significantly lower average total subgingival viable counts per patient, with reductions of 27.0% and 63.8%, respectively, than non-exposed control specimens (P < 0.0001). Similarly, both mouthrinses significantly reduced mean red/orange complex periodontal pathogen counts/patient by 74.4% and 97.4%, respectively, as compared to non-exposed control specimens (P < 0.0001). The iClean(R) mouthrinse better reduced average total subgingival viable counts and red/orange complex periodontal pathogen counts than the Iorinse(R) RTU mouthrinse (P-values < 0.0002 and < 0.0044, respectively). All evaluated red/orange complex periodontal pathogens were suppressed below detection by the Iorinse(R) RTU mouthrinse in 17 (53.1%) patient samples, and by the iClean(R) mouthrinse in 29 (90.6%) patient samples. Subgingival species resistant in vitro to the Iorinse(R) RTU mouthrinse were P. intermedia/nigrescens (8 of 25 patient strains), P. micra (7 of 32 patient strains), and F. nucleatum (6 of 30 patient strains), whereas species resistant to the iClean(R) mouthrinse were P. intermedia/nigrescens (1 of 25 patient strains), P. micra (2 of 32 patient strains), and F. nucleatum (2 of 30 patient strains). Relative to a clinical subgingival isolate of P. nigrescens, the Iorinse(R) RTU mouthrinse produced an 85% reduction, with the iClean(R) mouthrinse and both povidone-iodine concentrations (10% and 0.1%) attaining 100% reductions in total viable cell counts of P. nigrescens after 60 seconds of in vitro exposure. Conclusions: The Iorinse(R) RTU or iClean(R) mouthrinses both exhibited rapid invitro antimicrobial activity against human subgingival biofilm microorganisms, inducing 27.0% to 63.8% reductions, respectively, in total subgingival viable counts, and 74.4% to 97.4% reductions, respectively, in red/orange periodontal pathogen counts. The iClean(R) mouthrinse provided significantly better antimicrobial activity against subgingival biofilm bacteria in vitro than the Iorinse(R) RTU mouthrinse. These findings suggest merit in the clinical use of both molecular iodine-based mouthrinses in the treatment and prevention of bacterial biofilm-related human periodontal diseases.

The objective of this study was to determine if topical antimicrobials silver sulfadiazine and povidone-iodine ointment increase rates of healing of equine distal limb wounds that heal by second intention. Second, to determine the effect of bandaging with these topical antimicrobials. Six healthy adult horses were used to create thirty-six, 2.5 cm2 standardized full-thickness metacarpal/tarsal skin wounds. Each wound was exposed to a single treatment: 1.0 % silver sulfadiazine cream bandaged (SSD-B), 1.0 % silver sulfadiazine slow release matrix bandaged (SDX-B), 1.0% silver sulfadiazine slow release matrix not bandaged (SDX-NB), povidone-iodine ointment bandaged (PI-B), untreated control bandaged (C-B) and untreated control not bandaged (C-NB) until healing. Wound area, granulation tissue area and perimeter were measured with planimetry software from digital images obtained at each observation. Exuberant granulation tissue was excised when present. The days until healing, rate of healing parameter, rates of contraction and epithelialization were compared among groups using pair-wise analysis of least square means. The healing parameters and mean days to healing did not statistically differ between groups. Analysis of percent wound contraction and rate of epithelialization between groups was similar. Mean number of days to healing ranged from 83 (PI-B and C-B) to101 (SSD-B). All bandaged wounds produced exuberant granulation tissue requiring excision compared to none of the unbandaged. The identified rates of epithelialization and wound contraction found insignificant differences between antimicrobial treated versus untreated wounds. Similarly, rates of epithelialization and wound contraction found insignificant differences between bandaged versus unbandaged wounds. Topical povidone-iodine and silver sulfadiazine did not increase rates of healing under bandage. The 1.0% silver sulfadiazine slow release matrix not bandaged (SDX-NB) adhered well to dry wounds. Silver sulfadiazine slow-release matrix provides does not impede wound healing and provides good adherence to dry wounds not amenable to bandaging. / Master of Science

As infecções adquiridas durante cirurgias oftalmológicas podem ter efeitos devastadores. O objetivo do presente estudo foi de comparar a proporção de culturas bacterianas negativas no fundo de saco conjuntival inferior após uma ou três gotas sequenciais de iodopovidona a 5% (PVPI). Os voluntários foram aleatoriamente designados para receber uma gota de PVPI (grupo PVPI) (no tempo 28 minutos) ou três gotas de PVPI (grupo PVPI+) (nos tempos 0, 20 e 28 minutos) no saco conjuntival inferior em olhos selecionados aleatoriamente. Um cotonete conjuntival foi identicamente obtido cinco minutos antes e 30 minutos após o tempo 0. A espessura corneana central foi medida da mesma maneira antes do tempo 0 e após o tempo 30 minutos. Os esfregaços conjuntivais foram incubados aerobicamente em meio líquido de tioglicolato enriquecido (caldo de carne) e em três meios de cultura sólidos (ágar chocolate, ágar de tripticase-soja com 5% de sangue de ovelha e ágar Sabouraud). No grupo PVPI (n=59), a proporção de olhos com culturas bacterianas negativas após o uso do PVPI (79,7%) não diferiu significativamente do valor basal (76,3%; p=0,7539). No grupo PVPI+ (n=61), a proporção de olhos com culturas bacterianas negativas após instilação de PVPI (85,3%) foi significativamente maior do que antes da intervenção (70,5%) (p=0,0177). No entanto, a análise estatística intergrupos não detectou esta diferença. Não houve diferença significativa na média da espessura corneana central antes e após a intervenção em ambos os grupos. A instilação de três gotas sequenciais de PVPI foi associada ao aumento na proporção de olhos com culturas conjuntivais negativas, enquanto que a instilação de uma única gota de PVPI não demonstrou este aumento. É necessário um estudo mais aprofundado para determinar se a diferença entre os regimes de administração da PVPI está associada a diferentes taxas de infecções oculares pós-operatórias. / Infections acquired during ophthalmic surgery can be devastating. The purpose of the current study is to compare the proportion of negative bacterial cultures after one versus three sequential drops of povidone-iodine (PI) 5% into the inferior conjunctival fornix. Patients were randomly assigned to receive 1 (PI group) drop (at time 28 minutes) or three (PI plus group) sequential drops (at time 0, 20 and 28 minutes) of PI 5% into the inferior conjunctival sac of one randomly selected eye. A conjunctival swab was identically obtained 5 minutes before and 30 minutes after time 0. Central corneal thickness (CCT) was measured in the same way before time 0 and after time 30. Conjunctival swabs were incubated aerobically in enriched Thioglycolate liquid medium (meat broth) and in three solid culture media (chocolate agar, trypticase soy agar with 5% sheep blood, and Sabouraud agar). In the PI group (n=59), the proportion of eyes with negative bacterial cultures after PI (79.7%) did not differ significantly from baseline (76.3%; p=0.7539). In the PI plus group (n=61), the proportion of eyes with negative bacterial cultures after PI (85.3%) was significantly higher than before PI (70.5%) (p=0.0177). However, the intergroup statistical analysis did not detect this difference.There was no significant difference in mean CCT before and after the intervention in both groups. Instillation of three sequential drops of PI was associated with an increase in the proportion of eyes with negative conjunctival cultures, while instillation of a single drop of PI did not demonstrate this increase.Further study is warranted to determine whether the difference between the PI administration regimens is also associated with differences in the rates of postoperative ocular infections.