5 research outputs found

    Postoperative sensitivity associated with low shrinkage versus conventional composites

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    Introduction. Postoperative sensitivity in restorative dentistry can be related to preparation trauma, dentin adhesives' ability to seal open dentinal tubules, deformation of restorations under occlusal stresses and microleakage. Objective. The study assessed possible reduction in postoperative sensitivity with low shrinkage compared to conventional composites using different bonding agents and the influence of the operator skill on the incidence of postoperative sensitivity. Methods. Nine hundred and sixty permanent premolars and molars with primary carious lesions from patients 21 to 40 years old were used. Cavities 2 to 3 mm deep and with margins in enamel were prepared by four operators. Two operators had five years (A and B) and two had over 20 years (C and D) of clinical experience. Teeth were divided into eight groups each contained 120 restorations: (1) Els®+James-2 (original formula), (2) Els®+James-2 (new formula), (3) Els®+Excite, (4) InTenSe®+James-2 (original formula), (5) InTenSe®+James-2 (new formula), (6) InTenSe®+Excite, (7) Tetric Ceram®+Excite, and (8) Point 4®+OptiBond Solo Plus. At 14 days postoperatively, two independent operators, who did not take part in the clinical procedure, assessed postoperative teeth sensitivity using special questionnaires. Data were analyzed using non-parametric chi-square, Mann-Whitney and ANOVA tests. Results. Group 8 showed significantly higher score than the other groups. Less postoperative sensitivity was reported with two low-shrinkage composites (groups 2, 3, and 5) but with no significant difference. There was no statistical difference between groups 1, 2, 3, 4, 5, 6 and 7. Operator A had the highest postoperative sensitivity score compared to the other three. Conclusion. Conventional composite material Point 4® with its bonding agent caused significantly more postoperative sensitivity than low shrinkage composites combined with different adhesives. Operator skill influenced the incidence of postoperative sensitivity.Uvod. Posle postavljanja kompozitnih ispuna može da se javi postoperaciona osetljivost izazvana preparacionom traumom, sposobnošću adhezivnog sistema da hermetički zatvori dentinske kanaliće, deformacijom pod okluzalnim opterećenjem ili prodorom bakterijskih toksina. Cilj rada. Cilj istraživanja je bio da se ispita da li je osetljivost zuba manja kod kompozita s malom kontrakcijom u poređenju s konvencionalnim kompozitima i odgovarajućim adhezivnim sistemima, kao i uticaj veštine stomatologa na incidenciju postoperacione osetljivosti zuba. Metode rada. Na 960 premolara i molara stalne denticije s primarnim karijesom, pacijenata starosti od 21 godine do 40 godina, preparisani su kaviteti dubine 2-3 mm s rubovima u gleđi. Čitavu proceduru su obavila četiri specijalista stomatologije, od kojih su dva imala pet (A i B), a druga dva više od 20 godina kliničkog iskustva (C i D). Zubi su svrstani u osam grupa od po 120 uzoraka prema korišćenom kompozitnom i adhezivnom sistemu: 1) Els®+James-2; 2) Els®+James-2 (nova formula); 3) Els®+Excite; 4) InTenSe®+James-2; 5) InTenSe®+James-2 (nova formula); 6) InTenSe®+Excite; 7) Tetric Ceram®+Excite; i 8) Point 4®+OptiBond Solo Plus. Dve nedelje posle intervencije dva nezavisna stomatologa (koja nisu učestvovala u kliničkoj proceduri) ocenjivala su posebnim upitnicima postoperacionu osetljivost zuba. Podaci su analizirani neparametrijskim c2, Man-Vitnijevim (Mann-Whitney) i ANOVA testom. Rezultati. U osmoj grupi utvrđena je statistički značajno češća postoperaciona osetljivost nego u ostalim grupama zuba. Nije bilo statistički značajne razlike između grupa 1, 2, 3, 4, 5, 6 i 7. Kompoziti sa nižom polimerizacionom kontrakcijom izazvali su manju postoperacionu ostetljivost, ali bez statističke značajnosti razlika (grupe 2, 3 i 5). Kod stomatologa A javljala se statistički značajno češće postoperaciona osetljivost nego kod ostala tri. Zaključak. Tip kompozitnog materijala s odgovarajućim adhezivnim sistemom i spretnost stomatologa utiču na učestalost pojave osetljivosti zuba posle restauracija srednje dubokih kaviteta II klase

    Transesterification of used cooking sunflower oil catalyzed by hazelnut shell ash

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    Hazelnut shell ash was investigated as a new base catalyst for the transesterification of used cooking sunflower oil to biodiesel. To understand its catalytic properties, the prepared ash was characterized by EDX, XRD, TGA/DTA, Hg porosimetry, N-2 physisorption, FE-SEM, and basic strength measurements. The effects of the catalyst loading in the range of 1-5% of the oil weight and the methanol-to-oil molar ratio of 6:1-18:1 on the kinetics of the fatty acid methyl esters synthesis were established. Moreover, the leaching and reusability of the catalyst were assessed. The obtained results revealed that hazelnut shell ash was mostly composed of K, Ca, and Mg. The highest ester content (98%) was achieved at the catalyst loading of 5%, the methanol-to-oil molar ratio of 12:1, and the reaction time of 10 min. The contribution of homogeneous catalysis because of the catalyst leaching was confirmed but did not determine the overall reaction rate. The catalyst can be reused after the recalcination at 800 degrees C for 2 h achieving the high methyl esters content (>96%) in 30 min after three subsequent runs. The overall reaction followed the pseudo-first-order kinetics with respect to triacylglycerols. A linear relationship between the apparent reaction rate constant and the catalyst loading and the methanol-to-oil molar ratio was determined. The determined value of the reaction rate constant was 0.0576 dm(6)/(min.mol(2))

    AusTraits: a curated plant trait database for the Australian flora

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    INTRODUCTION AusTraits is a transformative database, containing measurements on the traits of Australia’s plant taxa, standardised from hundreds of disconnected primary sources. So far, data have been assembled from > 250 distinct sources, describing > 400 plant traits and > 26,000 taxa. To handle the harmonising of diverse data sources, we use a reproducible workflow to implement the various changes required for each source to reformat it suitable for incorporation in AusTraits. Such changes include restructuring datasets, renaming variables, changing variable units, changing taxon names. While this repository contains the harmonised data, the raw data and code used to build the resource are also available on the project’s GitHub repository, http://traitecoevo.github.io/austraits.build/. Further information on the project is available in the associated publication and at the project website austraits.org. Falster, Gallagher et al (2021) AusTraits, a curated plant trait database for the Australian flora. Scientific Data 8: 254, https://doi.org/10.1038/s41597-021-01006-6 CONTRIBUTORS The project is jointly led by Dr Daniel Falster (UNSW Sydney), Dr Rachael Gallagher (Western Sydney University), Dr Elizabeth Wenk (UNSW Sydney), and Dr Hervé Sauquet (Royal Botanic Gardens and Domain Trust Sydney), with input from > 300 contributors from over > 100 institutions (see full list above). The project was initiated by Dr Rachael Gallagher and Prof Ian Wright while at Macquarie University. We are grateful to the following institutions for contributing data Australian National Botanic Garden, Brisbane Rainforest Action and Information Network, Kew Botanic Gardens, National Herbarium of NSW, Northern Territory Herbarium, Queensland Herbarium, Western Australian Herbarium, South Australian Herbarium, State Herbarium of South Australia, Tasmanian Herbarium, Department of Environment, Land, Water and Planning, Victoria. AusTraits has been supported by investment from the Australian Research Data Commons (ARDC), via their “Transformative data collections” (https://doi.org/10.47486/TD044) and “Data Partnerships” (https://doi.org/10.47486/DP720) programs; fellowship grants from Australian Research Council to Falster (FT160100113), Gallagher (DE170100208) and Wright (FT100100910), a grant from Macquarie University to Gallagher. The ARDC is enabled by National Collaborative Research Investment Strategy (NCRIS). ACCESSING AND USE OF DATA The compiled AusTraits database is released under an open source licence (CC-BY), enabling re-use by the community. A requirement of use is that users cite the AusTraits resource paper, which includes all contributors as co-authors: Falster, Gallagher et al (2021) AusTraits, a curated plant trait database for the Australian flora. Scientific Data 8: 254, https://doi.org/10.1038/s41597-021-01006-6 In addition, we encourage users you to cite the original data sources, wherever possible. Note that under the license data may be redistributed, provided the attribution is maintained. The downloads below provide the data in two formats: austraits-3.0.2.zip: data in plain text format (.csv, .bib, .yml files). Suitable for anyone, including those using Python. austraits-3.0.2.rds: data as compressed R object. Suitable for users of R (see below). Both objects contain all the data and relevant meta-data. AUSTRAITS R PACKAGE For R users, access and manipulation of data is assisted with the austraits R package. The package can both download data and provides examples and functions for running queries. STRUCTURE OF AUSTRAITS The compiled AusTraits database has the following main components: austraits ├── traits ├── sites ├── contexts ├── methods ├── excluded_data ├── taxanomic_updates ├── taxa ├── definitions ├── contributors ├── sources └── build_info These elements include all the data and contextual information submitted with each contributed datasets. A schema and definitions for the database are given in the file/component definitions, available within the download. The file dictionary.html provides the same information in textual format. Full details on each of these components and columns are contained within the definition. Similar information is available at http://traitecoevo.github.io/austraits.build/articles/Trait_definitions.html and http://traitecoevo.github.io/austraits.build/articles/austraits_database_structure.html. CONTRIBUTING We envision AusTraits as an on-going collaborative community resource that: Increases our collective understanding the Australian flora; and Facilitates accumulation and sharing of trait data; Builds a sense of community among contributors and users; and Aspires to fully transparent and reproducible research of the highest standard. As a community resource, we are very keen for people to contribute. Assembly of the database is managed on GitHub at traitecoevo/austraits.build. Here are some of the ways you can contribute: Reporting Errors: If you notice a possible error in AusTraits, please post an issue on GitHub. Refining documentation: We welcome additions and edits that make using the existing data or adding new data easier for the community. Contributing new data: We gladly accept new data contributions to AusTraits. See full instructions on how to contribute at http://traitecoevo.github.io/austraits.build/articles/contributing_data.html

    AusTraits, a curated plant trait database for the Australian flora

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    International audienceWe introduce the austraits database-a compilation of values of plant traits for taxa in the Australian flora (hereafter AusTraits). AusTraits synthesises data on 448 traits across 28,640 taxa from field campaigns, published literature, taxonomic monographs, and individual taxon descriptions. Traits vary in scope from physiological measures of performance (e.g. photosynthetic gas exchange, water-use efficiency) to morphological attributes (e.g. leaf area, seed mass, plant height) which link to aspects of ecological variation. AusTraits contains curated and harmonised individual-and species-level measurements coupled to, where available, contextual information on site properties and experimental conditions. This article provides information on version 3.0.2 of AusTraits which contains data for 997,808 trait-by-taxon combinations. We envision AusTraits as an ongoing collaborative initiative for easily archiving and sharing trait data, which also provides a template for other national or regional initiatives globally to fill persistent gaps in trait knowledge
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