167 research outputs found

    Impact of systemic diseases and tooth-based factors on outcome of root canal treatment.

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    Aim To investigate the impact of systemic health and tooth-based factors on the outcome of root canal treatment (RCT). Methodology The target population consisted of all patients receiving RCT at the Helsinki University Clinic in 2008-2011. The inclusion criteria were diagnosable pre- and postoperative (minimum 6 months after root filling) radiographs and adequate patient records of RCT available. Teeth extracted for nonendodontic reasons were excluded. Patient documents including digital radiographs of 640 permanent teeth in 504 patients were scrutinized. The radiographs were assessed by two examiners under standardized conditions. The Periapical Index was used to define radiographically 'healthy' and 'healing' cases as successful. Data included systemic health, technical quality of root fillings, type of restoration and level of alveolar bone loss. Statistical evaluation of differences between groups included chi-squared tests and Fisher's exact tests. Logistic regression modelling utilizing robust standard errors to allow for clustering within patients was applied to analyse factors related to the outcome of RCT. Results The mean age of patients was 51.5 years (standard deviation (SD) 15.0; range 10-83), and 49% were female. In 41 cases (6%), the patient had diabetes mellitus (DM), in 132 (21%) cardiovascular disease and in 284 (44%) no systemic disease. The follow-up period was 6-71 months (mean 22.7). In the primary analyses, the success rate of RCT was 73.2% in DM patients and 85.6% in patients with no systemic disease (P = 0.043); other systemic diseases had no impact on success. In the multifactorial analysis, the impact of DM became nonsignificant and RCTs were more likely to succeed in the absence of apical periodontitis (AP; odds ratio (OR) = 4.4; P <0.001), in teeth with optimal root filling quality (OR = 2.5; P <0.001), in teeth restored with indirect restorations (OR = 3.7; P = 0.002) and in teeth with none/mild alveolar bone loss (OR = 2.4; P = 0.003). Conclusions DM diminished the success of RCT, especially in teeth with apical periodontitis. However, tooth-based factors had a more profound impact on the outcome of RCT. This should be considered in clinical decision-making and in assessment of RCT prognosis.Peer reviewe

    Bayesian analysis of the radial velocities of HD 11506 reveals another planetary companion

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    We aim to demonstrate the efficiency of a Bayesian approach in analysing radial velocity data by reanalysing a set of radial velocity measurements. We present Bayesian analysis of a recently published set of radial velocity measurements known to contain the signal of one extrasolar planetary candidate, namely, HD 11506. The analysis is conducted using the Markov chain Monte Carlo method and the resulting distributions of orbital parameters are tested by performing direct integration of randomly selected samples with the Bulirsch-Stoer method. The magnitude of the stellar radial velocity variability, known as jitter, is treated as a free parameter with no assumptions about its magnitude. We show that the orbital parameters of the planet known to be present in the data correspond to a different solution when the jitter is allowed to be a free parameter. We also show evidence of an additional candidate, a 0.8 MJup planet with period of about 0.5 yr in orbit around HD 11506. This second planet is inferred to be present with a high level of confidence.Comment: 4 pages, 5 figures, to appear in A&

    Radiographic outcome of root canal treatment in general dental practice: tooth type and quality of root filling as prognostic factors

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    Objective:This study evaluated the radiographic outcome of root canal treatments (RCTs) performed by general dental practitioners (GDPs) with focus on tooth type and quality of root filling. Materials and methods:The target population included all patients receiving root filling by GDPs in City of Helsinki in 2010-2011. Equal numbers of each tooth type (anteriors, premolars, molars) by jaw were included, resulting in 426 teeth. Pre- and post-operative periapical radiographs were assessed to evaluate periapical status and quality of root filling. Statistical evaluation utilized Chi-squared tests, Cohen's kappa and logistic regression modelling. Results:The overall success rate of RCT was 67.4%, being 76.8%, 69.7% and 55.6% (p <.001) for anteriors, premolars and molars, respectively. The quality of root fillings varied by tooth type (p <.001); optimal fillings were least frequent (43%) in molars. In multifactorial analysis, RCTs were more likely to succeed in non-molars (OR = 1.8), in teeth with optimal root fillings (OR = 3.6) and in teeth without apical periodontitis (OR = 3.2). Conclusion:The quality of root fillings and radiographic outcome of RCTs varied considerably according to tooth type; success was least likely in molars. Improvement is needed in quality of RCTs by GDPs.Peer reviewe

    O K -edge and CuL23-edge XANES study on the concentration and distribution of holes in the (Pb2/3Cu1/3)3Sr2(Y ,Ca)Cu2O8+z superconductive phase

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    By means of high-resolution O K-edge and Cu L23-edge x-ray absorption near-edge-structure spectroscopy continuous increase of the CuO2-plane hole concentration with increasing Ca-substitution level has been established for the superconductive, oxygen-depleted (z≈0) (Pb2/3Cu1/3)3Sr2(Y1−xCax)Cu2O8+z [(Pb2/3Cu1/3)−3212] phase with a three-layer PbO-Cu-PbO charge-reservoir block. For the O K-edge absorption, a pre-edge peak at ∼528.3 eV is seen, originating from the excitation of the O 1s electron to the O 2p hole state located in the CuO2 plane. With increasing Ca-substitution level, the intensity of this peak continuously increases within the substitution range studied, i.e., 0<~x<~0.5. Consistently, with increasing x, the shoulder on the high-energy side of the main absorption peak at ∼932.0 eV in the Cu L23-edge spectra, i.e., a feature typically assigned to formally trivalent copper, enhances. From the Cu L23-edge spectra it was furthermore confirmed that the charge-reservoir copper remains in the monovalent state, indicating that the holes created through Ca substitution are directed solely into the superconductive CuO2 plane. In terms of increasing the CuO2-plane hole concentration, Ca substitution was found to work more efficiently in (Pb2/3Cu1/3)−3212 as compared to, e.g., the related Bi-2212 phase.Peer reviewe

    Wood-decaying Basidiomycetes Associated with Dwarf Siberian Pine in Northeast Siberia and the Kamchatka Peninsula

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    A survey of the biodiversity of wood-decaying Basidiomycetes associated with Pinus pumila (the dwarf Siberian pine), a highly characteristic woody plant of Northeast Siberia and the Kamchatka Peninsula, is presented for the first time. Thirty-two species of wood-decaying Basidiomycetes were recorded in the area for this tree, ofwhich twenty-seven were described the first time: 19 species in the Magadan region and 9 in the Kamchatka Peninsula. Communities of wood-decaying fungi associated with P. pumila have low biodiversity and consist of 16 species in the Kamchatka Peninsula and 21 species in the Magadan region, with only 5 of them being common to both areas. All fungi associated with dwarf Siberian pine belong to widespread species and are not specialized to this tree: they are extremely low in numbers and their composition strongly varies in different habitats. This shows that this tree does not have its own specialized and stable complex of wood-decaying Basidiomycetes. Keywords: biodiversity, Czekanowski-Sørensen index, host-specializatio

    The complementarity of astrometric and radial velocity exoplanet observations - Determining exoplanet mass with astrometric snapshots

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    We obtain full information on the orbital parameters by combining radial velocity and astrometric measurements by means of Bayesian inference. We sample the parameter probability densities of orbital model parameters with a Markov chain Monte Carlo (McMC) method in simulated observational scenarios to test the detectability of planets with orbital periods longer than the observational timelines. We show that, when fitting model parameters simultaneously to measurements from both sources, it is possible to extract much more information from the measurements than when using either source alone. We demonstrate this by studying the orbit of recently found extra-solar planet HD 154345 b.Comment: 6 pages, 9 figures. Accepted to A&

    Layered-specific hole concentrations in Bi2Sr2(Y1-xCax)Cu2O8+d as probed by XANES spectroscopy and coulometric redox analysis

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    Induction of holes not only in the superconductive CuO2 plane but also in the Bi2O2+d charge reservoir of the Bi2Sr2(Y1-xCax)Cu2O8+d superconductor upon CaII-for-YIII substitution is evidenced by means of two independent techniques, i.e., high-resolution x-ray-absorption near-edge structure (XANES) spectroscopy measurements and coulometric redox titrations. The absolute values derived for the CuO2-plane hole concentration from the Cu L2,3-edge XANES spectra are in good agreement with those obtained from the coulometric redox analysis. The CuO2-plane hole concentration is found to increase from 0.03 to 0.14 concomitantly with the increase in the BiO1+d/2-layer hole concentration from 0.00 to 0.13 as the Ca-substitution level, x, increases from 0 to 1. The threshold CuO2-plane hole concentration for the appearance of superconductivity is determined at 0.06, while the highest Tc is obtained at the hole concentration of 0.12. In the O K-edge XANES spectrum, the increases in the CuO2-plane and BiO1+d/2-layer hole concentrations with increasing x are seen as enhancement in the relative intensities of the pre-edge peaks at ~528.3 and \~530.5 eV, respectively.Comment: 12 pages, 6 figures, to appear in Phys. Rev.

    Layer-specific hole concentrations in Bi2Sr2(Y1-xCax)Cu208+[delta] as probed by XANES spectroscopy and coulometric redox analysis

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    Induction of holes not only in the superconductive CuO2 plane but also in the Bi2O2+δ charge reservoir of the Bi2Sr2(Y1-xCax)Cu2O8+δ superconductor upon CaII-for-YIII substitution is evidenced by means of two independent techniques, i.e., high-resolution x-ray-absorption near-edge structure (XANES) spectroscopy measurements and coulometric redox titrations. The absolute values derived for the CuO2-plane hole concentration from the Cu L2,3-edge XANES spectra are in good agreement with those obtained from the coulometric redox analysis. The CuO2-plane hole concentration is found to increase from 0.03 to 0.14 concomitantly with the increase in the BiO1+δ/2-layer hole concentration from 0.00 to 0.13 as the Ca-substitution level, x, increases from 0 to 1. The threshold CuO2-plane hole concentration for the appearance of superconductivity is determined at 0.06, while the highest Tc is obtained at the hole concentration of 0.12. In the O K-edge XANES spectrum, the increases in the CuO2-plane and BiO1+δ/2-layer hole concentrations with increasing x are seen as enhancement in the relative intensities of the pre-edge peaks at ∼528.3 and ∼530.5 eV, respectively.Peer reviewe
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