1,727 research outputs found

    Effectiveness of Educational Poster on Knowledge of Emergency Management of Dental Trauma - Part 2: Cluster Randomised Controlled Trial for Secondary School Students

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    Objective To investigate the effectiveness of educational poster on improving secondary school students' knowledge of emergency management of dental trauma. Methods A cluster randomised controlled trial was conducted. 16 schools with total 671 secondary students who can read Chinese or English were randomised into intervention (poster, 8 schools, 364 students) and control groups (8 schools, 305 students) at the school level. Baseline knowledge of dental trauma was obtained by a questionnaire. Poster containing information of dental trauma management was displayed in a classroom for 2 weeks in each school in the intervention group whereas in the control group there was no display of such posters. Students of both groups completed the same questionnarie after 2 weeks. Results Two-week display of posters improved the knowledge score by 1.25 (p-value = 0.0407) on average. Conclusion Educational poster on dental trauma management significantly improved the level of knowledge of secondary school students in Hong Kong.published_or_final_versio

    Finite element model with continuous transverse shear stress for composite laminates in cylindrical bending

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    In the double superposition hypothesis, the global inplane displacement, which applies to the whole laminate, is enriched by local displacements which are restricted to each individual ply. To avoid the number of d.o.f.s growing with the number of plies, the transverse shear stress continuity is enforced as usual whereas the inplane displacement continuity is "doubly" constrained for two different groups of the local displacement. Based on the hypothesis, a two-node beam element is attempted. The element has the deflection and its derivative as its nodal d.o.f.s. Despite the fact that interpolated deflection is a cubic function of the longitudinal coordinate, the element yields poor accuracy. The cause is sorted out to be an algebraic constraint in the transverse shear. To overcome the constraint, a heterosis node is added. Remarkable improvement of the element accuracy is noted. © 1998 Elsevier Science B.V. All rights reserved.postprin

    On discovery of extremely low-dimensional clusters using semi-supervised projected clustering

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    Recent studies suggest that projected clusters with extremely low dimensionality exist in many real datasets. A number of projected clustering algorithms have been proposed in the past several years, but few can identify clusters with dimensionality lower than 10% of the total number of dimensions, which are commonly found in some real datasets such as gene expression profiles. In this paper we propose a new algorithm that can accurately identify projected clusters with relevant dimensions as few as 5% of the total number of dimensions. It makes use of a robust objective function that combines object clustering and dimension selection into a single optimization problem. The algorithm can also utilize domain knowledge in the form of labeled objects and labeled dimensions to improve its clustering accuracy. We believe this is the first semi-supervised projected clustering algorithm. Both theoretical analysis and experimental results show that by using a small amount of input knowledge, possibly covering only a portion of the underlying classes, the new algorithm can be further improved to accurately detect clusters with only 1% of the dimensions being relevant. The algorithm is also useful in getting a target set of clusters when there are multiple possible groupings of the objects. © 2005 IEEE.published_or_final_versio

    The developmental roles of the extracellular matrix: Beyond structure to regulation

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    Cells in multicellular organisms are surrounded by a complex three-dimensional macromolecular extracellular matrix (ECM). This matrix, traditionally thought to serve a structural function providing support and strength to cells within tissues, is increasingly being recognized as having pleiotropic effects in development and growth. Elucidation of the role that the ECM plays in developmental processes has been significantly advanced by studying the phenotypic and developmental consequences of specific genetic alterations of ECM components in the mouse. These studies have revealed the enormous contribution of the ECM to the regulation of key processes in morphogenesis and organogenesis, such as cell adhesion, proliferation, specification, migration, survival, and differentiation. The ECM interacts with signaling molecules and morphogens thereby modulating their activities. This review considers these advances in our understanding of the function of ECM proteins during development, extending beyond their structural capacity, to embrace their new roles in intercellula signaling. © 2009 Springer-Verlag.postprin

    Complete genomic sequence of Epstein-Barr virus in nasopharyngeal carcinoma cell line C666-1

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    Emergency management of dental trauma: knowledge of Hong Kong primary and secondary school teachers.

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    HARP: A practical projected clustering algorithm

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    In high-dimensional data, clusters can exist in subspaces that hide themselves from traditional clustering methods. A number of algorithms have been proposed to Identify such projected clusters, but most of them rely on some user parameters to guide the clustering process. The clustering accuracy can be seriously degraded If incorrect values are used. Unfortunately, in real situations, it is rarely possible for users to supply the parameter values accurately, which causes practical difficulties in applying these algorithms to real data. In this paper, we analyze the major challenges of projected clustering and suggest why these algorithms need to depend heavily on user parameters. Based on the analysis, we propose a new algorithm that exploits the clustering status to adjust the internal thresholds dynamically without the assistance of user parameters. According to the results of extensive experiments on real and synthetic data, the new method has excellent accuracy and usability. It outperformed the other algorithms even when correct parameter values were artificially supplied to them. The encouraging results suggest that projected clustering can be a practical tool for various kinds of real applications.published_or_final_versio

    Predictor-corrector procedures for analysis of laminated plates using standard Mindlin finite element models

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    This paper introduces predictor-corrector methods for finite element analysis of laminated composite plates. The predictor stress, strain and deflection are directly computed from Mindlin finite element models without using shear correction factors. The corrector transverse shear stress is determined from the homogeneous stress equilibrium condition and the predictor in-plane stress by least-square fit. Shear correction factor for each element is estimated as the ratio of the transverse shear energies computed by the predictor transverse shear strain and the corrector transverse shear stress. The corrector deflection is calculated by incorporating the shear correction factor. First-, second- and third-order Mindlin nine-node plate elements are employed for testing the proposed procedure. Its accuracy is demonstrated by a large number of examples. © 2000 Elsevier Science Ltd.postprin

    Evaluating the prognostic factors associated with cancer-specific survival of differentiated thyroid carcinoma presenting with distant metastasis

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    BACKGROUND: Because patients with differentiated thyroid carcinoma (DTC) presenting with distant metastasis (DM) have a particularly poor prognosis, examining the prognostic factors in this group is essential. We aimed to evaluate the prognostic factors affecting cancer-specific survival (CSS) in DTC patients presenting with DM. METHODS: Of the 1227 DTC patients, 51 (4.2 %) presented with DM at diagnosis. All patients underwent a total thyroidectomy, followed by radioiodine (RAI) ablation and postablation whole body scan (WBS). Patients were considered to have an osseous metastasis if one of the metastatic sites involved a bone, while RAI avidity was determined by any visual uptake in a known metastatic site on the first WBS. Factors predictive of CSS were determined by univariate and multivariate analyses by the Cox proportional hazard model. RESULTS: In univariate analysis, older age (relative risk [RR] 1.050, 95 % confidence interval [CI] 1.010-1.091, P = 0.014), DM discovered before WBS (RR 3.401, 95 % CI 1.127-10.309, P = 0.030), follicular thyroid carcinoma (RR 3.095, 95 % CI 1.168-8.205, P = 0.025), osseous metastasis (RR 4.695, 95 % CI 1.379-15.873, P = 0.013), non-RAI avidity (RR 3.355, 95 % CI 1.280-8.772, P = 0.014), and external beam radiotherapy to DM (RR 3.241, 95 % CI 1.093-9.614, P = 0.034) were significant poor prognostic factors for CSS. In the multivariate analysis, after adjusting for other factors, osseous metastasis (RR 6.849, 95 % CI 1.495-31.250, P = 0.013) and non-RAI avidity (RR 7.752, 95 % CI 2.198-27.027, P = 0.001) were the two independent poor prognostic factors for CSS. Older age almost reached statistically significance (RR 1.055, 95 % CI 0.996-1.117, P = 0.068). CONCLUSIONS: DTC patients presenting with DM accounted for 4.2 % of all patients. Because osseous metastasis and RAI avidity were independent prognostic factors, future therapy should be directed at improving the treatment efficacy of osseous and/or non-RAI-avid metastases.published_or_final_versio
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