306 research outputs found
Candida species in patients with oral dysesthesia: A comparison of carriage among oral disease states
OBJECTIVES: Oral dysesthesia (burning mouth syndrome) is characterized by a burning-like sensation of the oral mucosa. The etiology of this disorder is still unknown, however, associations with oral fungal carriage have been proposed and applied clinically. The aim of the this study was to compare oral Candida carriage in patients with oral dysesthesia with Candida carriage in patients with other commonly diagnosed oral diseases to clarify the relationship between Candida and oral dysesthesia. SUBJECTS AND METHODS: In total, 441 patients in total including 79 patients diagnosed with oral dysesthesia were included in this study. A retrospective analysis of mycological investigations undertaken in patients with clinically diagnosed oral dysesthesia compared with other oral conditions was undertaken. RESULTS: Oral carriage of Candida was found in 63.3% (50 of 79) of patients with oral dysesthesia. The frequency of carriage and oral load of Candida were not significantly increased in patients with oral dysesthesia relative to the other conditions assessed. Patients with clinical signs of fungal infection or xerostomia presented with increased carriage of Candida. CONCLUSION: There is no association between oral dysesthesia and the presence or load of oral Candida
Commercial window glass tested as possible high dose dosimeter. Electron and gamma irradiation
The use of commercial window glass as possible high dose routine dosimeter has been investigated. Glass samples have been irradiated with doses in the range of 1-50 kGy using 60Co γ source, 4 MeV and 12 MeV electron accelerators. The samples were given a post irradiation thermal treatment (150 oC for 20 min) in order to improve the post irradiation stability of the measured specific optical absorbance, since a rapid fading of the optical absorbance has been observed at room temperature immediately after irradiation. The optical absorbance measurements of the irradiated samples, kept in the dark and at room temperature, were carried on for several weeks. The samples submitted to heat treatment showed a decrease of about 10-15% of the specific optical absorbance that became much less pronounced after 10 days from the irradiation. The response of the window glass plates is energy and dose rate dependent. This study shows the feasibility of using commercial window glass as a routine dosimeter in a certain dose range after proper calibration in the irradiation plant where they are going to be used
Normal limits for oscillometric bronchodilator responses and relationships with clinical factors.
Introduction: We aimed to determine normal thresholds for positive bronchodilator responses for oscillometry in an Australian general population sample aged ≥40 years, to guide clinical interpretation. We also examined relationships between bronchodilator responses and respiratory symptoms, asthma diagnosis, smoking and baseline lung function. Methods: Subjects recruited from Sydney, Melbourne and Busselton, Australia, underwent measurements of spirometry, resistance (R rs6 ) and reactance (X rs6 ) at 6 Hz, before and after inhalation of salbutamol 200 μg. Respiratory symptoms and/or medication use, asthma diagnosis, and smoking were recorded. Threshold bronchodilator responses were defined as the fifth percentile of decrease in R rs6 and 95th percentile increase in X rs6 in a healthy subgroup. Results: Of 1318 participants, 1145 (570 female) were analysed. The lower threshold for ΔR rs6 was -1.38 cmH2O·s·L-1 (-30.0% or -1.42 Z-scores) and upper threshold for ΔX rs6 was 0.57 cmH2O·s·L-1 (1.36 Z-scores). Respiratory symptoms and/or medication use, asthma diagnosis, and smoking all predicted bronchodilator response, as did baseline oscillometry and spirometry. When categorised into clinically relevant groups according to those predictors, ΔX rs6 was more sensitive than spirometry in smokers without current asthma or chronic obstructive pulmonary disease (COPD), ∼20% having a positive response. Using absolute or Z-score change provided similar prevalences of responsiveness, except in COPD, in which responsiveness measured by absolute change was twice that for Z-score. Discussion: This study describes normative thresholds for bronchodilator responses in oscillometry parameters, including intra-breath parameters, as determined by absolute, relative and Z-score changes. Positive bronchodilator response by oscillometry correlated with clinical factors and baseline function, which may inform the clinical interpretation of oscillometry
Materiais didáticos no ensino e aprendizagem da matemática
O relatório final de estágio apresenta-se no âmbito do Mestrado em Educação Pré-Escolar e Ensino do 1.º Ciclo do Ensino Básico. Este inclui uma reflexão crÃtica relativamente à s unidades curriculares de Prática de Ensino Supervisionada (II e III), em contexto de estágio, no 1.º Ciclo do Ensino Básico e na Educação Pré-Escolar. O relatório contempla ainda uma investigação cuja temática se centra na área da Matemática.
Para a realização da primeira parte do relatório, foram utilizados diversos materiais construÃdos e implementados ao longo das PES II e III, bem como autores de referência, de forma a fundamentar o texto.
Relativamente à segunda parte do relatório final de estágio foi realizada uma investigação de caráter qualitativo, que teve como principal objetivo perceber de que forma a utilização de materiais didáticos, em aulas do 1.º Ciclo do Ensino Básico, influencia a aprendizagem da Matemática, num tópico muito particular: números racionais. Desta forma, foi realizado um teste diagnóstico de forma a perceber o conteúdo em que os alunos sentiam mais dificuldades. Posteriormente, foram desenvolvidas três tarefas diferentes, utilizando materiais didáticos distintos e, foi ainda realizada uma entrevista semiestruturada aos três participantes do estudo.
A análise dos dados recolhidos permitiu concluir, com alguma segurança, que a utilização de materiais didáticos, em conteúdos matemáticos, é benéfica para os alunos, pois revelam maior envolvimento nas tarefas propostas e uma melhor compreensão dos conteúdos abordados.The final apprenticeship report is related to the scope of the Masters Degree of Pre-schooling and Teaching the 1st Cycle of Basic School. It includes a critical reflection in relation to the curricular units of Supervised Teaching Practice (II and III), in the context of apprenticeship, in the 1st Cycle of Basic School and in Pre-school Education. The report also contemplates research whose theme concentrates on the fields of mathematics.
For the first part of the report several different materials were used, which had been built and implemented along STP II and III, as well as authors of reference, so as to support the text.
In relation to the second part of the apprenticeship final report, a qualitative research was carried out, which main purpose was to understand to which extent the use of didactic materials in the 1st cycle of Basic School classes influences the learning of mathematics, in a very particular topic: rational numbers. This way, a diagnosis was performed for a better understanding of the contents in which learners feel the most difficulties. Later on three tasks were developed, by using different didactic materials, and a semi-structured interview was held to the three participants in the study.
The analysis of the collected data allowed to conclude, with some certainty, that the use of didactic materials in mathematical contents is beneficial for learners, because they reveal a greater involvement in the proposed tasks and a better understanding of the addressed contents
Bacteria-Killing Type IV Secretion Systems
Bacteria have been constantly competing for nutrients and space for billions of years.
During this time, they have evolved many different molecular mechanisms by which
to secrete proteinaceous effectors in order to manipulate and often kill rival bacterial
and eukaryotic cells. These processes often employ large multimeric transmembrane
nanomachines that have been classified as types I–IX secretion systems. One of the
most evolutionarily versatile are the Type IV secretion systems (T4SSs), which have
been shown to be able to secrete macromolecules directly into both eukaryotic and
prokaryotic cells. Until recently, examples of T4SS-mediated macromolecule transfer
from one bacterium to another was restricted to protein-DNA complexes during
bacterial conjugation. This view changed when it was shown by our group that many
Xanthomonas species carry a T4SS that is specialized to transfer toxic bacterial effectors
into rival bacterial cells, resulting in cell death. This review will focus on this special
subtype of T4SS by describing its distinguishing features, similar systems in other
proteobacterial genomes, and the nature of the effectors secreted by these systems
and their cognate inhibitor
Enhanced virtual microscopy for collaborative education
<p>Abstract</p> <p>Background</p> <p>Curricular reform efforts and a desire to use novel educational strategies that foster student collaboration are challenging the traditional microscope-based teaching of histology. Computer-based histology teaching tools and Virtual Microscopes (VM), computer-based digital slide viewers, have been shown to be effective and efficient educational strategies. We developed an open-source VM system based on the Google Maps engine to transform our histology education and introduce new teaching methods. This VM allows students and faculty to collaboratively create content, annotate slides with markers, and it is enhanced with social networking features to give the community of learners more control over the system.</p> <p>Results</p> <p>We currently have 1,037 slides in our VM system comprised of 39,386,941 individual JPEG files that take up 349 gigabytes of server storage space. Of those slides 682 are for general teaching and available to our students and the public; the remaining 355 slides are used for practical exams and have restricted access. The system has seen extensive use with 289,352 unique slide views to date. Students viewed an average of 56.3 slides per month during the histology course and accessed the system at all hours of the day. Of the 621 annotations added to 126 slides 26.2% were added by faculty and 73.8% by students. The use of the VM system reduced the amount of time faculty spent administering the course by 210 hours, but did not reduce the number of laboratory sessions or the number of required faculty. Laboratory sessions were reduced from three hours to two hours each due to the efficiencies in the workflow of the VM system.</p> <p>Conclusions</p> <p>Our virtual microscope system has been an effective solution to the challenges facing traditional histopathology laboratories and the novel needs of our revised curriculum. The web-based system allowed us to empower learners to have greater control over their content, as well as the ability to work together in collaborative groups. The VM system saved faculty time and there was no significant difference in student performance on an identical practical exam before and after its adoption. We have made the source code of our VM freely available and encourage use of the publically available slides on our website.</p
Long-term effects of tongue piercing — a case control study
The aim of this study was to evaluate tooth and periodontal damage in subjects wearing a tongue piercing (TP) in comparison to matched control subjects without tongue piercing. Members of the German Federal Armed Forces who had TP (group TP) and a matched control group (group C) volunteered to take part in the study. The time in situ, localization and material of TP were documented. Dental examinations included DMF-T, oral hygiene, enamel fissures (EF), enamel cracks (EC) and recessions. Statistical analysis was determined by χ2 test and the t test. Both groups had 46 male subjects (mean age 22.1 years). The piercings had been in situ for 3.8 ± 3.1 years. Subjects in the TP group had a total of 1,260 teeth. Twenty-nine subjects had 115 teeth (9.1%) with EF (67% lingual). In group C (1,243 teeth), 30 subjects had 60 teeth with EF (4.8%, 78% vestibular) (p < 0.01). Thirty-eight subjects belonging to group TP had EC in 186 teeth (15%). In group C, 26 subjects with 56 teeth (4.5%) were affected by EC (p < 0.001). Twenty-seven subjects in group TP had 97 teeth (7.7%) with recessions. Lingual surfaces of anterior teeth in the lower jaw were affected most frequently (74%). In group C, 8 subjects had 19 teeth (1.5%) with recessions (65% vestibular). Differences between the two groups were statistically significant (p < 0.001). Tongue piercing is correlated with an increased occurrence of enamel fissures, enamel cracks and lingual recessions. Patients need better information on the potential complications associated with tongue piercing
Antibody reactivity against potato apyrase, a protein that shares epitopes with Schistosoma mansoni ATP diphosphohydrolase isoforms, in acute and chronically infected mice, after chemotherapy and reinfection
Schistosoma mansoni ATP diphosphohydrolase isoforms and potato apyrase share conserved epitopes. By enzyme-linked immunosorbent assays, elevated levels of IgM, IgG2a and IgG1 antibody reactivity against potato apyrase were observed in S. mansoni-infected BALB/c mice during the acute phase of infection, while only IgM and IgG1 antibody reactivity levels maintained elevated during the chronic phase of infection. Antibody reactivity against potato apyrase was monitored over an 11-month period in chronically-infected mice treated with oxamniquine. Eleven months later, the level of seropositive IgM decreased significantly (~30%) compared to the level found in untreated, infected mice. The level of seropositive IgG1 decreased significantly four months after treatment (MAT) (61%) and remained at this level even after 11 months. The IgG2a reactivity against potato apyrase, although unchanged during chronic phase to 11 MAT, appeared elevated again in re-infected mice suggesting a response similar to that found during the acute phase. BALB/c mouse polyclonal anti-potato apyrase IgG reacted with soluble egg antigens probably due to the recognition of parasite ATP diphosphohydrolase. This study, for the first time, showed that the IgG2a antibody from S. mansoni-infected BALB mice cross-reacts with potato apyrase and the level of IgG2a in infected mice differentiates disease phases. The results also suggest that different conserved-epitopes contribute to the immune response in schistosomiasis
Diagnostic aids in the screening of oral cancer
The World Health Organization has clearly indentified prevention and early detection as major objectives in the control of the oral cancer burden worldwide. At the present time, screening of oral cancer and its pre-invasive intra-epithelial stages, as well as its early detection, is still largely based on visual examination of the mouth. There is strong available evidence to suggest that visual inspection of the oral mucosa is effective in reducing mortality from oral cancer in individuals exposed to risk factors. Simple visual examination, however, is well known to be limited by subjective interpretation and by the potential, albeit rare, occurrence of dysplasia and early OSCC within areas of normal-looking oral mucosa. As a consequence, adjunctive techniques have been suggested to increase our ability to differentiate between benign abnormalities and dysplastic/malignant changes as well as to identify areas of dysplasia/early OSCC that are not visible to naked eye. These include the use of toluidine blue, brush biopsy, chemiluminescence and tissue autofluorescence. The present paper reviews the evidence supporting the efficacy of the aforementioned techniques in improving the identification of dysplastic/malignant changes of the oral mucosa. We conclude that available studies have shown promising results, but strong evidence to support the use of oral cancer diagnostic aids is still lacking. Further research with clear objectives, well-defined population cohorts, and sound methodology is strongly required
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