Effect of external tooth bleaching on the surface of resin composites – An in vitro study

AbstractObjectivesTo evaluate the effects of external tooth whitening on the surface of two types of resin composites, by scanning electron microscopy (SEM).MethodsEighteen (N=18) specimens were assigned into six groups using two composites: a nanohybrid (Tetric EvoCeram®) and a nanofill (Filtek Supreme XT®); and three protocols: 10% carbamide peroxide (CP) whitening (TW10 and FW10); 22% CP whitening (TW22 and FW22); control group (TC and FC). For each group, the resin composite was introduced into a silicon mold and light-cured according to manufacturer's instructions. Specimens were stored in distilled water (37°C, 24h), polished, and then randomly divided into the mentioned groups. Specimens from the whitening groups were exposed to the CP gels (White Dental Beauty®) for 6h per day. TC and FC specimens were exposed to distilled water. All specimens were stored in an incubator (37°C, 14 days) and observed by SEM. It was measured the hydrogenionic potential (pH) of the CP gels.ResultsSEM analysis of both composites exposed to the CP gels showed surface changes, namely superficial cracks and numerous porous, highlighting a real separation between the resin matrix and the composite fillers, regardless of the gel concentration. These changes were more notorious in the nanohybrid composite. 10% and 22% CP gels have a pH value of 6.71 and 7.42, respectively.ConclusionThe 10% and 22% CP led to changes on both surface composites. These alterations are pronounced in the nanohybrid composite and are independent of the concentrations used

Flower development and sex specification in wild grapevine

Background: Wild plants of Vitis closely related to the cultivated grapevine (V. v. vinifera) are believed to have been first domesticated 10,000 years BC around the Caspian Sea. V. v. vinifera is hermaphrodite whereas V. v. sylvestris is a dioecious species. Male flowers show a reduced pistil without style or stigma and female flowers present reflexed stamens with infertile pollen. V. vinifera produce perfect flowers with all functional structures. The mechanism for flower sex determination and specification in grapevine is still unknown.Results: To understand which genes are involved during the establishment of male, female and complete flowers, we analysed and compared the transcription profiles of four developmental stages of the three genders. We showed that sex determination is a late event during flower development and that the expression of genes from the ABCDE model is not directly correlated with the establishment of sexual dimorphism. We propose a temporal comprehensive model in which two mutations in two linked genes could be players in sex determination and indirectly establish the Vitis domestication process. Additionally, we also found clusters of genes differentially expressed between genders and between developmental stages that suggest a role involved in sex differentiation. Also, the detection of differentially transcribed regions that extended existing gene models (intergenic regions) between sexes suggests that they may account for some of the variation between the subspecies.Conclusions: There is no evidence of differences of expression levels in genes from the ABCDE model that could explain the shift from hermaphroditism to dioecy. We propose that sex specification occurs after floral organ identity has been established and therefore, sex determination genes might be having an effect downstream of the ABCDE model genes. For the first time a full transcriptomic analysis was performed in different flower developmental stages in the same individual. Our experimental approach enabled us to create a comprehensive catalogue of transcribed genes across developmental stages and genders that will contribute for future work in sex determination in seed plants.This work was supported by the funded project PTDC/AGR-GPL/119298/2010 from Fundacao para a Ciencia e Tecnologia and MRocheta, JLCoito and JCunha by the fellowships FRH/BPD/64905/2009, SFRH/BD/85824/2012 and SFRH/BPD/74895/2010, respectively. We are also grateful to Eng. Eiras- Dias, curator from Portuguese Ampelographic Collection (property of Instituto Nacional de Investigacao Agraria e Veterinaria, Dois Portos), for the collaboration in this work allowing the access to the Vitis collection

Portuguese wild grapevine genome re-sequencing (Vitis vinifera sylvestris)

Supplementary information is available for this paper at https://doi.org/10.1038/s41598-020-76012-6.The first genome of Vitis vinifera vinifera (PN40024), published in 2007, boosted grapevine related studies. While this reference genome is a suitable tool for the overall studies in the field, it lacks the ability to unveil changes accumulated during V. v. vinifera domestication. The subspecies V. v. sylvestris preserves wild characteristics, making it a good material to provide insights into V. v. vinifera domestication. The difference in the reproductive strategy between both subspecies is one of the characteristics that set them apart. While V. v. vinifera flowers are hermaphrodite, V. v. sylvestris is mostly dioecious. In this paper, we compare the re-sequencing of the genomes from a male and a female individual of the wild sylvestris, against the reference vinifera genome (PN40024). Variant analysis reveals a low number but with high impact modifications in coding regions, essentially non-synonymous single nucleotide polymorphisms and frame shifts caused by insertions and deletions. The sex-locus was manually inspected, and the results obtained are in line with the most recent works related with wild grapevine sex. In this paper we also describe for the first time RNA editing in transcripts of 14 genes in the sex-determining region, including VviYABBY and VviPLATZ.Tis work was supported by Fundação para a Ciência e Tecnologia (FCT) through the Research Center LEAF (UIDP/04129/2020). Authors JLCoito, MJNRamos, MRocheta, were funded by FCT fellowships SFRH/ BD/85824/2012 and CEECIND2017, SFRH/BD/110274/2015, SFRH/BPD/64905/2009, respectively

RNA editing in inflorescences of wild grapevine unveils association to sex and development

RNA editing challenges the central dogma of molecular biology, by modifying the genetic information at the transcription level. Recent reports, suggesting increased levels of RNA editing in plants, raised questions on the nature and dynamics of such events during development. We here report the occurrence of distinct RNA editing patterns in wild Vitis flowers during development, with twelve possible RNA editing modifications observed for the first time in plants. RNA editing events are gender and developmental stage specific, identical in subsequent years of this perennial species and with distinct nucleotide frequencies neighboring editing sites on the 5' and 3' flanks. The transcriptome dynamics unveils a new regulatory layer responsible for gender plasticity enhancement or underling dioecy evolution in Vitis

Relembrar o sindrome de realimentação

The Refeeding Syndrome was described in adult survivors of concentration camps in 1945, and regained attention following introduction of total parenteral nutrition in the 1970s. Refeeding syndrome is characterized by severe fluid and electrolytes shifts especially phosphate), associated with metabolic abnormalities in malnourished patients undergoing refeeding, whether orally, enterally, or parenterally. Clinical features involve cardiac, neurologic, hematologic events and even sudden death. It is not an uncommon entity and may be seen in 0,8 % of all hospitalized adult patients. It is very important to be aware of the syndrome to prevent this potentially lethal condition: recognize those at risk; laboratory data must be monitored and abnormal values corrected accordingly; and finally, a slow increase in caloric delivery is recommended. Not all clinics and institutions have nutritional support teams. So it is important to educate heath care practitioners to the potential danger of too aggressively refeeding a chronically malnourished patient – and so remember Refeeding Syndrome. A síndrome de Realimentação foi descrita em adultos sobreviventes dos campos de concentração em 1945 e voltou a ganhar a atenção da comunidade médica após a introdução da alimentação parentérica total na década de 1970. Esta síndrome é caracterizada por alterações de fluidos e electrólitos (especialmente fósforo) associada a alterações metabólicas em doentes desnutridos, nos quais se inicia suporte nutricional por via oral, entérica ou parentérica. A clínica inclui manifestações cardíacas, neurológicas, hematológicas e mesmo morte súbita. Ocorre em 0,8 % dos adultos hospitalizados. É fundamental conhecer esta síndrome de forma a prevenir uma condição potencialmente letal: reconhecer doentes em risco; proceder à monitorização laboratorial e à correcção de anomalias e, finalmente, recomenda-se um aumento progressivo do aporte calórico. Nem todos os hospitais têm grupos de suporte nutricional, pelo que é importante relembrar a Síndrome de Realimentação para que os profissionais de saúde conheçam o perigo potencial de realimentar de forma agressiva um doente desnutrido.

Deep analysis of wild Vitis flower transcriptome reveals unexplored genome regions associated with sex specification

RNA-seq of Vitis during early stages of bud development, in male, female and hermaphrodite flowers, identified new loci outside of annotated gene models, suggesting their involvement in sex establishment. The molecular mechanisms responsible for flower sex specification remain unclear for most plant species. In the case of V. vinifera ssp. vinifera, it is not fully understood what determines hermaphroditism in the domesticated subspecies and male or female flowers in wild dioecious relatives (Vitis vinifera ssp. sylvestris). Here, we describe a de novo assembly of the transcriptome of three flower developmental stages from the three Vitis vinifera flower types. The validation of de novo assembly showed a correlation of 0.825. The main goals of this work were the identification of V. v. sylvestris exclusive transcripts and the characterization of differential gene expression during flower development. RNA from several flower developmental stages was used previously to generate Illumina sequence reads. Through a sequential de novo assembly strategy one comprehensive transcriptome comprising 95,516 non-redundant transcripts was assembled. From this dataset 81,064 transcripts were annotated to V. v. vinifera reference transcriptome and 11,084 were annotated against V. v. vinifera reference genome. Moreover, we found 3368 transcripts that could not be mapped to Vitis reference genome. From all the non-redundant transcripts that were assembled, bioinformatics analysis identified 133 specific of V. v. sylvestris and 516 transcripts differentially expressed among the three flower types. The detection of transcription from areas of the genome not currently annotated suggests active transcription of previously unannotated genomic loci during early stages of bud development.funded project PTDC/AGR-GPL/119298/2010 from Fundação para a Ciência e Tecnologia (FCT, Portugal). MRocheta, JLCoito, JCunha, MCosta, MRamos and HGSilva are supported by FCT fellowships SFRH/BPD/64905/2009, SFRH/BD/85824/2012, SFRH/BPD/74895/2010, SFRH/BSAB/113781/2015, SFRH/BD/110274/2015 and SFRH/BD/111529/2015, respectively. We are also grateful to Eng. Eiras-Dias, curator from Portuguese Ampelographic Collection (property of Instituto Nacional de Investigação Agrária e Veterinária, Dois Portos) where sampling was performed, for the collaboration in this work allowing the access to the Vitis collectioninfo:eu-repo/semantics/publishedVersio