205 research outputs found

    Evaluation of Proanthocyanidin-based dentifrices on dentin-wear after erosion and dental abrasion - In situ study

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    Proanthocyanidin has been considered as a preventive agent against erosion because of its properties, which involves remineralization, reduction of demineralization and matrix metalloproteinases (MMPs) inhibition. Thus, the aim of this in situ study was

    Indirect evaluation of pit and fissure sealants : a 3D-based method validation

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    The aim of the present study was to compare indirect methods to assess the clinical performance of pit and fissure sealants and validate the use of 3D scanners. Sample consisted of 58 plaster models of upper and lower first permanent molars, sealed with resin sealants, as well as photographs obtained during the 18-month follow-up. Pre-established criteria were applied to categorize the sealant presence/absence and marginal integrity. Two calibrated examiners performed the evaluations, independently, using Scanning Electron Microscopy (SEM; gold-standard), Photography, 3D (CEREC In Lab) and Stereomicroscope analysis. The intra-examiner Spearman correlation was 94% e 97%, respectively, and the inter-examiner was 96%. Data was submitted to Kappa test, Spearman correlation and Receiver Operating Characteristic Curve (ROC). 3D and SEM presented good concordance; Stereomicroscope showed regular concordance with SEM and 3D (p0.05). SEM had a significant positive correlation with 3D and Stereomicroscope (r=0.76 and 0.71, respectively; p<0.01). There was significant positive correlation (r=0.65) between 3D and Stereomicroscope (p<0.01). The ROC estimated curve areas for Stereomicroscope and 3D were 0.90 (IC:0.81-0.99) and 1.0 (IC:1.0-1.0), respectively (p<0.001). Photography presented lower sensitivity and specificity (area=0.59). 3D method showed the best performance when compared to gold standard, exhibiting high sensitivity and specificity, therefore, it was validated as a reliable method to evaluate pit and fissure sealants

    Soybean oil prevents hypothalamic N3 fatty acid composition but does not prevent peripheral tissue fatty acid disturbance in rats

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    Linoleic (LA) and alpha-linolenic (ALA) acids are the only truly essential N6 and N3 polyunsaturated fatty acids (PUFAs), and the precursors of arachidonicand docosahexaenoic (DHA) acids, the most prevalent PUFAs in the mammalian brain. Whilst main dietary sources of N6 are plant oils and red meat, the main sources of DHA include seawater fish. This issue becomes apparent when considering typical westernised diets. Furthermore, marine sources are currently threatened due to overfishing and no sustainability. Here we investigated the serum, hypothalamus, liver and white adipose tissues (WAT) fatty acid (FA) composition of rats fed a diet enriched with either fish oil (FO) or soybean oil (SO). Whilst FO contains abundant DHA, SO provides small amounts of ALA, alongside its important LAcontent. Fifteen 35-day old Wistar rats were fed a control chow, or a diet enriched with FO (FOD) or SO (SOD) for 8 weeks. Rats were sacrificed, trunk blood collected, hypothalamus, liver and WAT dissected, and their FA composition analysed by gas chromatography. FOD increased N3 content and SOD increased N6 content in all tissues. However, SOD significantly increased DHAin hypothalamus and serum, a result not observed in other SOD tissues. Whilst the SOD rats developed obesity, the FOD did not. SOD rats developed obesity and imbalanced N6/N3 peripherally, but their hypothalamic N3 content was increased. Such results further corroborate biomagnification and the preferential FAuptake by the brain. Additional studies are necessary to investigate how nutrient-unbalanced diets further affect brain metabolism

    BINGO: A code for the efficient computation of the scalar bi-spectrum

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    We present a new and accurate Fortran code, the BI-spectra and Non-Gaussianity Operator (BINGO), for the efficient numerical computation of the scalar bi-spectrum and the non-Gaussianity parameter f_{NL} in single field inflationary models involving the canonical scalar field. The code can calculate all the different contributions to the bi-spectrum and the parameter f_{NL} for an arbitrary triangular configuration of the wavevectors. Focusing firstly on the equilateral limit, we illustrate the accuracy of BINGO by comparing the results from the code with the spectral dependence of the bi-spectrum expected in power law inflation. Then, considering an arbitrary triangular configuration, we contrast the numerical results with the analytical expression available in the slow roll limit, for, say, the case of the conventional quadratic potential. Considering a non-trivial scenario involving deviations from slow roll, we compare the results from the code with the analytical results that have recently been obtained in the case of the Starobinsky model in the equilateral limit. As an immediate application, we utilize BINGO to examine of the power of the non-Gaussianity parameter f_{NL} to discriminate between various inflationary models that admit departures from slow roll and lead to similar features in the scalar power spectrum. We close with a summary and discussion on the implications of the results we obtain.Comment: v1: 5 pages, 5 figures; v2: 35 pages, 11 figures, title changed, extensively revised; v3: 36 pages, 11 figures, to appear in JCAP. The BINGO code is available online at http://www.physics.iitm.ac.in/~sriram/bingo/bingo.htm

    The exposure of the hybrid detector of the Pierre Auger Observatory

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    The Pierre Auger Observatory is a detector for ultra-high energy cosmic rays. It consists of a surface array to measure secondary particles at ground level and a fluorescence detector to measure the development of air showers in the atmosphere above the array. The "hybrid" detection mode combines the information from the two subsystems. We describe the determination of the hybrid exposure for events observed by the fluorescence telescopes in coincidence with at least one water-Cherenkov detector of the surface array. A detailed knowledge of the time dependence of the detection operations is crucial for an accurate evaluation of the exposure. We discuss the relevance of monitoring data collected during operations, such as the status of the fluorescence detector, background light and atmospheric conditions, that are used in both simulation and reconstruction.Comment: Paper accepted by Astroparticle Physic

    An Integrated TCGA Pan-Cancer Clinical Data Resource to Drive High-Quality Survival Outcome Analytics

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    For a decade, The Cancer Genome Atlas (TCGA) program collected clinicopathologic annotation data along with multi-platform molecular profiles of more than 11,000 human tumors across 33 different cancer types. TCGA clinical data contain key features representing the democratized nature of the data collection process. To ensure proper use of this large clinical dataset associated with genomic features, we developed a standardized dataset named the TCGA Pan-Cancer Clinical Data Resource (TCGA-CDR), which includes four major clinical outcome endpoints. In addition to detailing major challenges and statistical limitations encountered during the effort of integrating the acquired clinical data, we present a summary that includes endpoint usage recommendations for each cancer type. These TCGA-CDR findings appear to be consistent with cancer genomics studies independent of the TCGA effort and provide opportunities for investigating cancer biology using clinical correlates at an unprecedented scale. Analysis of clinicopathologic annotations for over 11,000 cancer patients in the TCGA program leads to the generation of TCGA Clinical Data Resource, which provides recommendations of clinical outcome endpoint usage for 33 cancer types

    Defective removal of ribonucleotides from DNA promotes systemic autoimmunity

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    Genome integrity is continuously challenged by the DNA damage that arises during normal cell metabolism. Biallelic mutations in the genes encoding the genome surveillance enzyme ribonuclease H2 (RNase H2) cause Aicardi-Goutières syndrome (AGS), a pediatric disorder that shares features with the autoimmune disease systemic lupus erythematosus (SLE). Here we determined that heterozygous parents of AGS patients exhibit an intermediate autoimmune phenotype and demonstrated a genetic association between rare RNASEH2 sequence variants and SLE. Evaluation of patient cells revealed that SLE- and AGS-associated mutations impair RNase H2 function and result in accumulation of ribonucleotides in genomic DNA. The ensuing chronic low level of DNA damage triggered a DNA damage response characterized by constitutive p53 phosphorylation and senescence. Patient fibroblasts exhibited constitutive upregulation of IFN-stimulated genes and an enhanced type I IFN response to the immunostimulatory nucleic acid polyinosinic:polycytidylic acid and UV light irradiation, linking RNase H2 deficiency to potentiation of innate immune signaling. Moreover, UV-induced cyclobutane pyrimidine dimer formation was markedly enhanced in ribonucleotide-containing DNA, providing a mechanism for photosensitivity in RNase H2-associated SLE. Collectively, our findings implicate RNase H2 in the pathogenesis of SLE and suggest a role of DNA damage-associated pathways in the initiation of autoimmunity

    Luminescence characteristics of quartz from Brazilian sediments and constraints for OSL dating

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    This study analyzes the optically stimulated luminescence (OSL) characteristics of quartz grains from fluvial, eolian and shallow marine sands of northeastern and southeastern Brazil, with especial focus on the applicability of the single-aliquot regenerative dose (SAR) dating protocol. All analyzed Brazilian sediments presented relatively high OSL sensitivity and good behavior regarding their luminescence characteristics relevant for radiation dose estimation. However, some samples from the Lençóis Maranhenses region in northeastern Brazil showed inadequate OSL sensitivity correction, hampering the implementation of the SAR protocol and their ability to behave as a natural dosimeter. While the shallow marine and eolian samples showed a narrow and reliable dose distribution, the fluvial sample had a wide dose distribution, suggesting incomplete bleaching and natural doses estimates dependent on age models
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