327 research outputs found

    Gingival Recession, Oral Hygiene and Associated Factors Among Tanzanian Women.

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    Females are generally more motivated with regard to oral hygiene practices and thus brush their teeth more frequently than males. To determine the prevalence of gingival recession, oral hygiene status, oral hygiene practices and associated factors in women attending a maternity ward in Tanzania. Cross-sectional descriptive study. Maternity ward of Muhimbili National Hospital, Tanzania. Four hundred and forty six women were interviewed on oral hygiene practices and maternal factors, and a full-mouth examination was done to determine the presence of plaque, calculus, gingival bleeding and gingival recession at six sites per tooth. The prevalence of gingival recession (GR) > or =1 mm was 33.6%, calculus 99.3%, plaque 100%, and gingival bleeding 100%. Oral hygiene practices included toothbrushing (98.9%), brushing frequency > or =2 times/day (61.2%), horizontal brushing method (98%), and using a plastic toothbrush (97.8%). Factors that were significantly associated with gingival recession were age (OR = 2.0, 95% CI = 1.3-3.2), presence of calculus (OR(a) = 3.8, 95% CI=2.5-7.1), and gingival bleeding on probing (OR = 4.2, 95% CI = 2.5-7.1). Tooth cleaning practices and maternal factors, especially the number of pregnancies or deliveries were not significantly associated with gingival recession. In this study population, oral hygiene was poor and gingival recession was associated with age, calculus and gingival inflammation rather than with tooth cleaning practices

    The effect of surface relaxation on the N-2 dissociation rate on stepped Ru: A Transition State Theory Study

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    van Harrevelt R, Honkala K, Norskov JK, Manthe U. The effect of surface relaxation on the N2 dissociation rate on stepped Ru: A Transition State Theory Study. Journal of Chemical Physics. 2006;124(2):026102: 026102

    The reaction rate for dissociative adsorption of N-2 on stepped Ru(0001): Six-dimensional quantum calculations

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    van Harrevelt R, Honkala K, Norskov JK, Manthe U. The reaction rate for dissociative adsorption of N2 on stepped Ru(0001): Six-dimensional quantum calculations. Journal of Chemical Physics. 2005;122(23): 234702.Quantum-mechanical calculations of the reaction rate for dissociative adsorption of N-2 on stepped Ru(0001) are presented. Converged six-dimensional quantum calculations for this heavy-atom reaction have been performed using the multiconfiguration time-dependent Hartree method. A potential-energy surface for the transition-state region is constructed from density-functional theory calculations using Shepard interpolation. The quantum results are in very good agreement with the results of the harmonic transition-state theory. In contrast to the findings of previous model calculations on similar systems, the tunneling effect is found to be small. (C) 2005 American Institute of Physics

    GINGIVAL RECESSION, ORAL HYGIENE AND ASSOCIATED FACTORS AMONG TANZANIAN WOMEN

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    Background: Females are generally more motivated with regard to oral hygiene practices andthus brush their teeth more frequently than males.Objective: To determine the prevalence of gingival recession, oral hygiene status, oral hygienepractices and associated factors in women attending a maternity ward in Tanzania.Design: Cross-sectional descriptive study.Setting: Maternity ward of Muhimbili National Hospital, Tanzania.Subjects: Four hundred and forty six women were interviewed on oral hygiene practicesand maternal factors, and a full-mouth examination was done to determine the presence ofplaque, calculus, gingival bleeding and gingival recession at six sites per tooth.Results: The prevalence of gingival recession (GR) > 1mm was 33.6%, calculus 99.3%,plaque 100%, and gingival bleeding 100%. Oral hygiene practices included toothbrushing(98.9%), brushing frequency >2 times/day (61.2%), horizontal brushing method (98%), andusing a plastic toothbrush (97.8%). Factors that were significantly associated with gingivalrecession were age (ORa=2.0, 95% CI=1.3-3.2), presence of calculus (ORa=3.8, 95% CI=2.5-7.1),and gingival bleeding on probing (ORa=4.2, 95% CI=2.5-7.1). Tooth cleaning practices andmaternal factors, especially the number of pregnancies or deliveries were not significantlyassociated with gingival recession.Conclusion: In this study population, oral hygiene was poor and gingival recession wasassociated with age, calculus and gingival inflammation rather than with tooth cleaningpractices

    Enumeration and Decidable Properties of Automatic Sequences

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    We show that various aspects of k-automatic sequences -- such as having an unbordered factor of length n -- are both decidable and effectively enumerable. As a consequence it follows that many related sequences are either k-automatic or k-regular. These include many sequences previously studied in the literature, such as the recurrence function, the appearance function, and the repetitivity index. We also give some new characterizations of the class of k-regular sequences. Many results extend to other sequences defined in terms of Pisot numeration systems

    Don't be rejected, how can we help authors, reviewers and editors?:Report of a Symposium for Editors Publishers and Others with an Interest in Scientific Publication, Held in Boston on Wednesday, 11 March 2015, during the Annual Meeting of the International Association for Dental Research

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    This satellite symposium was the fifth in a series for editors, publishers, reviewers and all those with an interest in scientific publishing. It was held on Wednesday, 11 March 2015 at the IADR meeting in Boston, Massachusetts. The symposium attracted more than 210 attendees. The symposium placed an emphasis on strategies to ensure that papers are accepted by peer reviewed journals. The speaker, representing the Journal of Dental Research gave a history of peer review and explained how to access material to advise new authors. The speaker from India outlined the problems that occur when there is no culture for dental research and it is given a low priority in dental education. He outlined remedies. The speaker from SAGE publications described the help that publishers and editors can provide authors. The final speaker suggested that in developing countries it was essential to create alliances with dental researchers in developed countries and that local conferences to which external speakers were invited, stimulated research both in terms of quantity and quality. A wide ranging discussion then took place

    Predicting Catalysis: Understanding Ammonia Synthesis from First-Principles Calculations

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    Here, we give a full account of a large collaborative effort toward an atomic-scale understanding of modern industrial ammonia production over ruthenium catalysts. We show that overall rates of ammonia production can be determined by applying various levels of theory (including transition state theory with or without tunneling corrections, and quantum dynamics) to a range of relevant elementary reaction steps, such as N2 dissociation, H2 dissociation, and hydrogenation of the intermediate reactants. A complete kinetic model based on the most relevant elementary steps can be established for any given point along an industrial reactor, and the kinetic results can be integrated over the catalyst bed to determine the industrial reactor yield. We find that, given the present uncertainties, the rate of ammonia production is well-determined directly from our atomic-scale calculations. Furthermore, our studies provide new insight into several related fields, for instance, gas-phase and electrochemical ammonia synthesis. The success of predicting the outcome of a catalytic reaction from first-principles calculations supports our point of view that, in the future, theory will be a fully integrated tool in the search for the next generation of catalysts.http://dx.doi.org/10.1021/jp056982

    Cross-cultural differences of self-reported oral health behaviour in Japanese and Finnish dental students

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    Objective: To determine whether any differences existed in dental health behaviour between Japanese and Finnish dental students. Setting: Hiroshima University School of Dentistry and the University of Helsinki. Design: Comparison of cross-cultural differences of self-reported oral health behaviour. Subjects: Dental students, 337 in Japan and 113 in Finland. Method: Subjects were surveyed using the Japanese and Finnish versions of a 20-item questionnaire entitled Hiroshima University-Dental Behavioural Inventory (HU-DBI). Results: Only 2 per cent of Finnish students reported that they put off going to the dentist until they had toothache, compared to 56 per cent of Japanese students. Similarly, significantly more Japanese students thought that their teeth were getting worse despite their daily brushing, compared to their Finnish peers. The mean HU-DBI score of Year 1 Finnish students was higher than that of their Japanese peers, which suggested a higher level of dental health awareness in Finnish students upon entry into dental school. The mean scores of the Japanese students were lower than those of their Finnish peers until Year 3. The mean scores of Year 5 and Year 6 Japanese students were higher than that of Year 1 students, indicating raised self-care levels influenced by the course in preventive dentistry. The gender difference of the HU-DBI score was not a major feature in either country. Conclusions: Self-reported oral health behaviours seemed to be very different between the two countries, which reflected different culture and/or health education systems of the students

    Understanding the electrocatalysis of oxygen reduction on platinum and its alloys

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    Mycobacterium w - a promising immunotherapeutic intervention for diseases

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    Immunomodulating agents interact with the immune system and alter the outcome of specific immune processes. As our understanding of the immune system continues to evolve, there is a growing effort to identify agents with immunomodulating applications to use therapeutically to treat various diseases. Mycobacterium w (Mw), a heat-killed mycobacterium, is an atypical mycobacterial species that possesses strong immunomodulatory properties. Mw was initially evaluated as an immune-therapeutic against leprosy, but since then Mw has generated a lot of interest and been studied for therapeutic applications across a host of diseases, such as pulmonary tuberculosis, tuberculous pericarditis, sepsis, lung cancer, and more. This article summarizes a large body of work published in the past five decades, describing various aspects of Mw and its potential for further therapeutic development
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