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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
621

Associa????o entre anemia falciforme e a condi????o de sa??de bucal em crian??as e adolescentes

Brand??o, Carla Figueiredo 13 July 2018 (has links)
Submitted by Carla Santos (biblioteca.cp2.carla@bahiana.edu.br) on 2018-10-22T18:32:20Z No. of bitstreams: 1 Carla Brand??o.pdf: 11463955 bytes, checksum: 7b86dc1b9ca0bf79961564402a30e29b (MD5) / Approved for entry into archive by JOELMA MAIA (ebmsp-bibliotecacp2@bahiana.edu.br) on 2018-10-22T19:37:51Z (GMT) No. of bitstreams: 1 Carla Brand??o.pdf: 11463955 bytes, checksum: 7b86dc1b9ca0bf79961564402a30e29b (MD5) / Made available in DSpace on 2018-10-22T19:37:51Z (GMT). No. of bitstreams: 1 Carla Brand??o.pdf: 11463955 bytes, checksum: 7b86dc1b9ca0bf79961564402a30e29b (MD5) Previous issue date: 2018-07-13 / Anemia Falciforme (AF) ?? a doen??a heredit??ria monog??nica de maior preval??ncia no mundo. A presen??a de hemoglobina (Hb) S provoca altera????es sist??micas e face, causando defici??ncia na forma????o dos tecidos dent??rios e ??sseos, que podem levar a uma maior predisposi????o a desenvolver les??es de c??rie e outras ocorr??ncias. Objetivo: avaliar a condi????o bucal de crian??as e adolescentes com diagn??stico de AF. Metodologia: estudo de corte transversal com indiv??duos de 5 a 18 anos de idade provenientes do ambulat??rio de refer??ncia em Anemia Falciforme (Grupo AF) e sem hemoglobinopatias do col??gio p??blico do estado da Bahia, Brasil (Grupo Compara????o), totalizando 124 pessoas, 63 no grupo compara????o e 61 no grupo doen??a. Esta pesquisa foi aprovada pelo Comit?? de ??tica em Pesquisa da Escola Bahiana de Medicina e Sa??de P??blica ??? CAAE 54637816.7.0000.5544. Para o grupo AF foram utilizados como crit??rios de inclus??o: ser portador de AF e ter Hb S diagnosticado por eletroforese de Hb e/ou cromatografia l??quida de alta performance e estar na faixa et??ria estabelecida. Para o grupo compara????o: sem AF, aparentemente saud??veis. Estes dois grupos realizaram exame cl??nico bucal, anamnese, exame dos dentes, periodonto, oclus??o, verifica????o da cronologia de erup????o dent??ria, fluorose, avalia????o da capacidade tamp??o e fluxo salivar, al??m de responder question??rios sobre sua condi????o de sa??de, hist??ria da doen??a, desenvolvimento puberal e dieta. Resultados: Os indiv??duos com AF frequentavam mais as consultas odontol??gicas (p=0,040), apesar do CPO-D ter sido de 2,08 (?? 2,71) maior que o grupo compara????o (1,05 ??1,6) - p=0,013. O ceo-d foi de 2,3 (???2,6) e 0,88 (???1,2) respectivamente, com p=0,018. Foram encontradas presen??a de sangramento gengival e c??lculo dent??rio, sem diferen??as estatisticamente entre os grupos (p=0,984). Para fluxo salivar e capacidade tamp??o, n??o foram observadas diferen??as significativas para o fluxo (p= 0,334), entretanto o grupo AF apresentou uma menor capacidade tamponante (p=0,006). As m??s oclus??es mais encontradas foram sobressali??ncia maxilar, sendo 82% e 80%, desalinhamento anterior superior 36,1% e 30%, presen??a de diastema (31,04%) e (21,3%) para indiv??duos com AF e saud??veis respectivamente, por??m n??o houve diferen??as entre os grupos ao avaliar sua preval??ncia e ??ndice de necessidade de tratamento. A fluorose foi mais presente no grupo compara????o (70,3%) que nos indiv??duos com AF (36,1%) - (p=0,003). A cronologia de erup????o dos dentes permanentes foi semelhante entre os grupos (p=0,636). Os indiv??duos com AF apresentaram atraso no desenvolvimento puberal (p=0,003). Crian??as e adolescentes com AF consumiram menos carboidratos na sua dieta semanal e di??ria e tiveram um ??ndice de c??rie mais alto (ceo-d=2,0???2,9; CPOD=4,2???5,0) ??? (p= 0,906; p=0,989, respectivamente) que os do grupo compara????o (ceo-d=0,9???1,2; CPO-D=1,0???1,5) ??? (p=0,938; p=0,734, respectivamente). Conclus??o: crian??as e adolescentes com AF apresentaram uma condi????o bucal desfavor??vel quando comparadas as crian??as e adolescentes saud??veis, apresentando maior ??ndice de c??rie tanto na denti????o dec??dua como na permanente e menor capacidade tamp??o. Apesar de possu??rem uma dieta menos cariog??nica, frequentarem mais as consultas odontol??gicas de rotina em rela????o ao grupo compara????o, estes indiv??duos apresentaram a doen??a c??rie mais prevalente, e ?? poss??vel que esteja associado a outros fatores inerentes a AF como o uso de medica????es cont??nuas.
622

The role of salivary antimicrobial peptides in shaping Streptococcus mutans ecology

Phattarataratip, Ekarat 01 July 2010 (has links)
Antimicrobial peptides are among the repertoire of host innate immune defenses. In mucosal immunity, the health-disease balance can be greatly modulated by the interplay between host immune factors and colonized microflora. Microbial ecology within dental plaque is constantly shaped by environmental factors present within the oral cavity. Several antimicrobial peptides are detected in saliva and their bactericidal activities against oral bacteria, including Streptococcus mutans, the primary etiologic agent of dental caries, have been clearly demonstrated. However, the role of these antimicrobial peptides in S .mutans ecology and host caries experience is not well-defined. We hypothesized that various strains of S. mutans possess different inherent susceptibility/resistance profiles to host salivary antimicrobial peptides and that host-specific quantities of these peptides may influence plaque colonization by particular S. mutans strains. S. mutans strains from subjects with variable caries experience were tested for susceptibility to a panel of antimicrobial peptides, including HNP-1-3, HBD-2-3 and LL-37, revealing that the susceptibilities of S. mutans to these peptides were strain-specific. S. mutans strains from high caries subjects showed greater resistance to these peptides at varying concentrations than those from caries-free subjects. In addition, when combinations of these peptides were tested, they showed either additive or synergistic interaction against S. mutans. Determinations of the salivary levels of these peptides showed that their concentrations were highly variable among subjects with no correlation to host caries experience. However, positive relationships between the salivary concentrations of HNP-1-3 and MS in dental plaque were found. Additionally, the levels of a number of these peptides in saliva appeared to be positively correlated within an individual. An analysis of the salivary peptide concentrations and the susceptibility profiles of S. mutans strains showed that S. mutans strains obtained from subjects with higher concentration of HNP-1-3 in saliva appeared to be more resistant to HNP-1. Collectively, our findings showed that salivary antimicrobial peptides affect S. mutans ecology by restricting the overall growth of this bacterium within the oral cavity and that their activity may help select resistant strains of S. mutans to colonize within dental plaque. The relative ability of S. mutans to resist host salivary antimicrobial peptides may be considered a potential virulence factor for this species.
623

“Message in a Bottle”: Extracellular Vesicle microRNAs as Novel Biomarkers of Environmental Exposures and Health Outcomes

Comfort, Nicole January 2021 (has links)
Background: The physiological and pathophysiological roles of secreted membrane-enclosed vesicles known as extracellular vesicles (EVs) have become increasingly recognized, making the EV field a quickly evolving area of research. EVs and their encapsulated molecular material including microRNAs are key mediators of intercellular communication, making EVs analogous to a message in a bottle. This discovery has fundamentally changed the study of gene regulation, and understanding the central role of EVs and their cargo in health and disease will generate new opportunities for basic biology, diagnostics, and disease treatment. EV release and the packaging of molecular material into EVs can be altered by stressors such as air pollution exposure. Exposure to air pollution is associated with significant morbidity among individuals with asthma, especially children who participate in more frequent outdoor activities and are more susceptible to exposure due to their narrower airways and higher breathing rate. Thus, sensitive biomarkers of air pollution exposure are needed to identify children at risk of worsened symptoms and asthma exacerbations. Given their role in cell-to-cell communication, EVs also represent a plausible molecular mechanism in the etiology of disorders such as aging-related cognitive decline. Individuals with mild cognitive impairment and experiencing increased rates of cognitive decline are more likely to develop Alzheimer’s disease and other dementias, signifying the importance of identifying and treating cognitive impairment early. More precise identification of the neurobiological processes of cognitive decline in aging populations may provide critical insights into the precursors of late-life dementias and identify health interventions that can delay cognitive impairment or therapeutic targets for treatment. This dissertation evaluates the utility of EV-encapsulated microRNAs (EV-miRNAs) as biomarkers of environmental exposure (i.e., air pollution) and assesses their role in disease risk (i.e., cognitive decline) in two separate studies. First, in Chapters 2-3, using a cohort of children with asthma in the greater Boston area, we describe saliva EVs isolated from these children using a high-throughput method and explore the potential of salivary EV-miRNAs as easy-to-measure biomarkers of exposure to fine particulate matter (PM2.5), nitrogen dioxide (NO2), and ozone (O₃). Then, in Chapter 4, we evaluate the association between EV-miRNAs and cognitive function and rates of cognitive decline in a cohort of elderly men and discuss the utility of circulating EV-miRNAs as biomarkers of risk. Furthermore, we discuss the pathways that these EV-miRNAs target if they play a causal role in cognitive decline which could have implications for development of therapeutics. Methods: Drawing from the School Inner-City Asthma Study (SICAS), we isolated salivary EVs and EV-miRNA from children with asthma for analysis in relation to ambient exposure to PM₂.₅, NO₂, and O₃. In accordance with the recommended minimal experimental requirements for the definition of EVs, in Chapter 2 we employ multiple orthogonal methods to describe the EVs that were isolated from cell-free saliva using a high-throughput polymer-based reagent (ExoQuick-TC). In Chapter 3, we utilize EV-miRNA data generated via RNA sequencing and ambient air pollution data estimated using a validated spatiotemporal high-resolution model. We perform differential expression analyses to examine the effect of high exposure to PM₂.₅, NO₂, and O₃ on saliva EV-miRNA abundance. In Chapter 4, we leverage data from the Normative Aging Study, a longitudinal cohort of elderly men, to investigate whether circulating EV-miRNAs are associated with cognitive function and rates of cognitive decline. We used linear models to assess the relationship between plasma EV-miRNAs and cognitive function and linear mixed models to evaluate the relationship between plasma EV-miRNAs and rates of cognitive decline. We performed gene ontology functional enrichment and pathway enrichment analyses to identify the biological pathways that these EV-miRNAs would target if they play causal roles in cognitive decline. Results:In Chapter 2, we demonstrate that EVs can be isolated from human saliva using ExoQuick-TC. The saliva EVs isolated from ExoQuick (N=180) ranged in size but were mostly ~55 nm in diameter and expressed tetraspanins CD9 and CD63, canonical markers for EVs, but did not highly express the tetraspanin CD81. In Chapter 3, in a subset of the SICAS cohort (N=69), we show that relatively high (>19.37 parts per billion) short-term ambient NO2 exposure and relatively high (>38.38 parts per million) prior-day O3 exposure are associated with down-regulation of several saliva EV-miRNAs. We did not detect differential expression of any EV-miRNAs in relation to PM₂.₅ exposure over multiple time windows of exposure. Finally, in Chapter 4, multivariable linear and linear mixed models demonstrated a relationship between several plasma EV-miRNAs and global cognitive function and rates of global cognitive decline, measured by the Mini-Mental State Examination. Functional enrichment and pathway enrichment analyses revealed that the biological pathways targeted by these miRNAs are relevant in neurodegeneration, including pathways regulating synaptic function and plasticity and neuronal death. We found no association between EV-miRNAs and cognitive function or cognitive decline as assessed by cognitive tests measuring specific domains of cognitive function. Conclusion: This work demonstrates the opportunities that EV-miRNAs can create for advancing environmental health research. EV-miRNAs may serve as sensitive biomarkers of environmental exposures as well as biomarkers of risk and may play mechanistic roles in disease. We also make recommendations for integrating EV research into the field of environmental health. Future studies should continue to evaluate the potential of EV-miRNAs and seek to identify EV-miRNAs that can serve as mechanistic biomarkers between exposures and effect across all stages of life to (1) increase our understanding of the consequences of circulating miRNA changes and the contribution of the environment to heterogeneous disorders, (2) advance development of non-invasive diagnostics to allow for longitudinal monitoring, and (3) pave the way for new opportunities for disease prevention and treatment.
624

Critical Comparison of Total Vaporization- Solid Phase Microextraction vs Headspace- Solid Phase Microextraction

Train, Alexandra 05 1900 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / Solid Phase Microextraction (SPME) is a popular sampling technique that can be paired with Gas Chromatography/Mass Spectrometry (GC-MS). SPME-GC-MS is used in forensic chemistry due to its simplification of the sample preparation process. Headspace-Solid Phase Microextraction (HS-SPME) is a technique where the sample is heated to generate volatiles in the headspace of the vial. A SPME fiber is then inserted into the vial and the compounds in the headspace will bind to the fiber. Total Vaporization- Solid Phase Microextraction (TV-SPME) is a technique that is derived from the HS-SPME technique. In Chapter 1, the critical comparison of HS-SPME and TV-SPME is discussed. Samples including marijuana, essential oils, and CBD oil were utilized to compare the two techniques. The compounds of interest in marijuana are the three main cannabinoids: cannabinol (CBN), cannabidiol (CBD), and tetrahydrocannabinol (THC). The sample preparation and GC-MS parameters were kept the same for all samples to determine which SPME technique works best for these sample types and yielded the greatest sensitivity. It was found that HS-SPME shows greater sensitivity with CBN and equivalent sensitivity with essential oils, THC and CBD. In Chapter 2, the detection of synthetic cannabinoids utilizing liquid-liquid injection as well as HS-SPME and TV-SPME is discussed. The detection of these compounds is important because this type of drug has become more prevalent in the United States because they can be chemically altered slightly so they still have the effects of a drug but can evade drug legislation. The detection of synthetic cannabinoids using liquid injection was found to be successful but detection using HS-SPME and TV-SPME was found to be unsuccessful. In Chapter 3, the analyses of real and artificial saliva utilizing HS-SPME and TV-SPME is discussed. Determining the compounds present in real saliva and artificial saliva will be of importance for future research into determining if the presence of drugs in saliva can be analyzed with these techniques. The analyses of real and artificial saliva were found to be successful using HS-SPME, without derivatization, and TV-SPME, with and without derivatization. Many of the compounds present in the real saliva were detected and were confirmed to be compounds regularly found in saliva by other scientific literature.
625

MicroRNAs as salivary markers for periodontal diseases

Schmalz, Gerhard, Li, Simin, Burkhardt, Ralph, Rinke, Sven, Krause, Felix, Haak, Rainer, Ziebolz, Dirk January 2016 (has links)
The aim of this review is to discuss current findings regarding the roles of miRNAs in periodontal diseases and the potential use of saliva as a diagnostic medium for corresponding miRNA investigations. For periodontal disease, investigations have been restricted to tissue samples and five miRNAs, that is, miR-142-3p, miR-146a, miR-155, miR-203, and miR-223, were repeatedly validated in vivo and in vitro by different validation methods. Particularly noticeable are the small sample sizes, different internal controls, and different case definitions of periodontitis in in vivo studies. Beside of that, the validated miRNAs are associated with inflammation and therefore with various diseases. Furthermore, several studies successfully explored the use of salivary miRNA species for the diagnosis of oral cancer. Different cancer types were investigated and heterogeneous methodology was used; moreover, no overlap of resultswas found. In conclusion, fivemiRNAs have consistently been reported for periodontitis; however, their disease specificity, detectability, and expression in saliva and their importance as noninvasive markers are questionable. In principle, a salivary miRNA diagnostic method seems feasible.However, standardized criteria and protocols for preanalytics, measurements, and analysis should be established to obtain comparable results across different studies.
626

Comparative in vitro study of selected physical properties of activa, cention n and vitremer

Mohammed Khair, Ro'aa Mohammed Jafar Mohammed January 2021 (has links)
Magister Theologiae - MTh / This study aimed to determine the association between dimensional change and surface roughness (Ra) of Vitremer, Activa and Cention N after immersing them into two different media: acidic and artificial saliva media for the period of a year. Measurements were made at 10 time intervals during the observation period.
627

Obtaining Saliva From Toddlers for Cortisol Concentration Determination

Clements, Andrea D., Dixon, Wallace E., Jr., Salley, B. J. 01 June 2006 (has links)
No description available.
628

Importancia del pH, flujo y viscosidad salival sobre el desarrollo de caries dental en mujeres gestantes del primer trimestre

Jiménez Minaya, Rosario Isabel January 2004 (has links)
Durante el embarazo la mujer experimenta una serie de cambios fisiológicos algunos de éstos ocurren a nivel salival como son : pH, flujo y viscosidad salival que van a constituir un factor determinante en el desarrollo de la caries dental. Objetivo: Determinar la relación entre los cambios de pH, flujo y viscosidad salival con el desarrollo de caries dental en mujeres gestantes del primer trimestre. Material y Métodos: Se evaluaron muestras de saliva sin estimular a 30 gestantes del primer trimestre y 30, no gestantes que asistieron al consultorio de Dental del HONADOMANI San Bartolomé, cuyas edades estaban entre 20 a 35 años a las cuales se les determinó el pH mediante un Analizador, flujo mediante un recipiente milimetrado, viscosidad salival con la ayuda del viscosímetro de Ostwald y caries dental mediante el índice CPOD. Resultados: Para el grupo gestante fueron: pH = 6.44, flujo = 5.37 ml., viscosidad = 1.46cp., CPOD = 12.27 y para el grupo no gestante: pH = 7.20, flujo = 4.07ml., viscosidad = 1.48 cp. y CPOD 10.17. Conclusiones: Hay diferencia estadísticamente significativa en el pH, siendo los valores de las gestantes menores al de las no gestantes, Asimismo existe una correlación inversa entre pH salival y CPOD. Existe una diferencia significativa en el flujo salival ya que las mujeres gestantes presentaron un flujo salival mayor, que las mujeres no gestantes, no encontrándose una relación entre flujo salival y CPOD. No existe una diferencia significativa en la viscosidad salival en mujeres gestantes y no gestantes y no se encontró una relación entre viscosidad salival y CPOD. Existe una diferencia significativa en el CPOD, así las mujeres gestantes presentaron un CPOD mayor que el de las mujeres no gestantes. / During pregnancy women suffer a lot physiological changes, some of them occurs at salival aspect, like they are: pH, flow and salivary viscosity, that are going to be a determinant factor in the develop of dental caries. Objetive: To determine the relation ship between the changes of pH, flow and salivary viscosity against the develop of dental caries in first three month period pregnancy women. Material and Methods: lt was evaluated samples of saliva without stimulation from 30 first three-month period pregnants, and 30 no-pregnants that attended to the dental assistance of HONADOMANI San Bartolome, with ages between 20 to 35 years old, who were evaluated for pH through a analizer, flow using a milimeter beaker, for salivary viscosity whit the Ostwald viscosimeter, and dental caries by the DMFT index. Results: For the pregnant group it was presented: pH = 6.44, Flow = 5.37 ml. Viscosity = 1.46, DMFT = 12.27. and for the group no-pregnant :pH = 7.20, Flow = 4.07ml- viscosity = 1.48 and DMFT = 10.17. Conclusions: There was statistically significant difference in pH, being the pregnants scores lower than no-pregnants. Furthermore, there was a indirect correlation between salivary pH and DMFT. A significant difference exist between the salivary flow because pregnant women showed a higher salivary flow than the no - pregnant group, finding no correlation between salivary flow and DMFT. A significant difference exist in the DMFT, so the pregnant women showed a higher DMFT than the no-pregnant group. / Tesis
629

Susceptibility of restorations and adjacent enamel/dentin to erosion under different salivary flow conditions

Alghilan, Maryam Abdulkareem 12 1900 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / BACKGROUND: Dental erosion is a multifactorial condition that causes irreversible loss of dental hard tissues. Its development is highly influenced by saliva, with higher prevalence in hyposalivatory patients. There is no scientific consensus regarding the restorative treatment of choice for eroded teeth in such highly erosive conditions and to date, this has not been studied under in-vitro conditions. OBJECTIVES: To investigate the effect of erosion on direct tooth-colored restorations and adjacent enamel/dentin under different simulated salivary flow rates. METHODS: Bovine enamel and dentin specimens were prepared (n =16) and restored with the testing restorative materials, resin-composite (Filtek Z250), resin-modified glass ionomer (Fuji II LC), high viscosity glass ionomer cement (Fuji IX), and low viscosity glass ionomer cement (Fuji II).Then, submitted to an in-vitro erosion cycling model simulating different salivary flow rates (normal 0.5 ml/min and low 0.05 ml/min) and dental erosion protocols for 5 days. Surface loss of the restorative material and surrounding enamel/dentin surfaces were analyzed. A mixed-model ANOVAs and Sidak adjustment were used for statistical comparisons (p < 0.05). RESULTS: The surface loss was lower at 0.5 than at 0.05 ml/min, for all tested restorative materials except resin composite. Surface loss was higher in enamel and dentin adjacent to Filtek Z250 compared to Fuji II LC and Fuji IX, with no significant difference in enamel and dentin surface loss adjacent to Filtek Z250 and Fuji II. The restorations surface degradation was significantly lower for Filtek Z250 than for Fuji II, Fuji II LC, and Fuji IX, at both 0.5 and 0.05 ml/min; moreover, the surface loss was significantly lower for Fuji II LC than for Fuji II and Fuji IX, which did not differ from each other. CONCLUSION: Within the limitations of this study, it can be concluded that low salivary flow promoted higher erosive conditions. The use of Fuji II LC and Fuji IX may reduce erosive effects on enamel and dentin adjacent to restoration. Of the materials evaluated, resin-modified glass ionomer restoration may be the most suitable for restoration for patients at higher risk of erosion with low exposure to fluoride.
630

Studies in Applied Materials Science: Drug-Biofluid Interactions and Light-Emitting Polymer Films

Cornell, Ashley Lynn 12 May 2012 (has links)
Interactions of Asthma Drugs with Artificial Saliva and Mucus. Modeling pulmonary particulate transport requires related biofluid physicochemical properties. Aims included measuring the effects of common aerosol drugs on artificial saliva and diffusivities of asthma medications in mucus. Artificial saliva solutions doped with asthma medications were characterized by pH, interfacial tension, and rheology. To measure diffusion, drug concentration was monitored by time-dependent FTIR spectra, and diffusivity obtained using Fick¡¦s second law. Measured theophylline and albuterol diffusivities were ca. 10-6 cm2/s. Surface Modification of Polymer Films with Light-Emitting Chemicals. To develop a polymer film system that changed color in response to radiation, acid groups of poly(ethylene-co-acrylic acid) were used to attach two light-emitting polymers: 4„S-(octyloxy)-4-biphenylcarboxylic acid and 2,7-bis(bromomethyl)-9,9-dihexyl-9Hluorene. Each reaction step was confirmed using static contact angle goniometry, FTIR spectroscopy, and X-ray photoelectron spectroscopy. UV-Vis and fluorescence spectroscopy measured the absorption spectra. Modified films were irradiated (ƒÜ=254 nm) and produced blue emissions.

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