Comparison of two self-etching primers and effect of saliva contamination on shear bond strength of orthodontic brackets

Introduction: Saliva contamination during the bonding procedure is a common cause of bracket bond failure. By combining acid and primer in one component, self-etching primers (SEP) reduce the working time and the risk of contamination. Objectives: The purpose of this study was to investigate the effect of saliva contamination of the enamel surface on the shear bond strength of orthodontic brackets cemented with two self-etching primers. Materials and Methods: One hundred orthodontic brackets were bonded to human premolars with Transbond Plus Self-etching Primer (TPSEP, 3M Unitek, Monrovia, CA) or First Step (FS, Reliance Orthodontic Products, Itasca, IL) under the following enamel surface conditions: 1) dry enamel; 2) saliva contamination/ primer; 3) saliva contamination/ air drying/ primer; 4) primer/ saliva contamination; 5) primer/ saliva contamination/ air drying/ reapplication of the primer. Samples were stored for 7 days in water at 37ºC and submitted to 500 cycles of thermal stress. Bond failure sites were classified by an Adhesive Remnant Index score system. Results:Mean shear bond strengths were significantly higher in the TPSEP groups compared to the FS groups (p < .001). For the same adhesive, no significant differences were found between the enamel surface conditions. More adhesive failures were observed in the FS groups. Conclusions: Brackets bonded with TPSEP had the highest shear bond strength values, under the different enamel surface conditions. For both SEPs, bond strengths were not significantly affected by the enamel surface conditions. The FS groups failed more frequently at the enamel / resin interface.Introdução: A contaminação salivar é uma das principais causas de insucesso na cimentação de brackets. Os selfetching primers, recentemente introduzidos em ortodontia, reduzem o tempo de execução da técnica e a probabilidade de contaminação. Objectivos: Determinar o efeito da contaminação salivar na resistência adesiva a forças de corte de brackets ortodônticos, cimentados com dois self-etching primers. Materiais e Métodos: Foram cimentados 100 brackets em premolares humanos (10 amostras por grupo), utilizando 2 adesivos (Transbond Plus e First Step) e 5 condições de superfície: 1) Condição ideal, esmalte seco; 2) Contaminação salivar antes do primer; 3) Contaminação salivar e secagem antes do primer; 4) Contaminação salivar depois do primer; 5) Contaminação salivar depois do primer, secagem e reaplicação do primer. As amostras foram armazenadas 7 dias em água a 37ºC e sujeitas a 500 ciclos de termociclagem. A área de adesão foi observada ao microscópio óptico para determinar o tipo de falha adesiva. Resultados: A análise de variância demonstrou diferenças significativas entre as forças de resistência adesiva, sendo o Transbond Plus superior ao First Step. A contaminação não influenciou significativamente a resistência adesiva. Conclusões: 1) A resistência adesiva foi mais elevada com o Transbond Plus em comparação com o First Step, independentemente da condição. 2) Para ambos os selfetching primers, a adesão não foi significativamente afectada pela presença de saliva ou pelos procedimentos de descontaminação. 3) No grupo do First Step foi encontrado um maior número de falhas adesivas na interface dente / resina composta.info:eu-repo/semantics/publishedVersio

Influence of the storage in bottle on the antioxidant activities and related chemical characteristics of wine spirits aged with chestnut staves and micro-oxygenation

Different ageing technology of wine spirits (WSs) has been investigated, but little has been published on the chemical evolution of aged WS during storage in bottle. The purpose of this study was to examine how 12 months of storage in bottle affected the evolution of antioxidantactivity (DPPH, FRAP and ABTS assays), total phenolic index (TPI) and low molecular weight (LMW)compounds content of the WSs aged through alternative technology using three micro-oxygenationlevels (MOX) and nitrogen control (N). Results revealed the ability of phenolic compounds fromaged WSs to scavenge free radicals during storage in bottle. Among the in vitro antioxidant-activity methods, FRAP assay was the more effective to differentiate WSs according to the ageing technology.Concerning the overall influence of storage in bottle on antioxidant activity, and TPI and LMW compoundscontent, the higher results were obtained for the MOX modalities (O15, O30 and O60), whichshowed a similar evolution. In summary, this study provides innovative information, demonstratingthat the differences between the aged WSs imparted throughout the ageing process (resulting from different MOX levels) were mostly retained, and only slight modifications during storage in bottle were found.info:eu-repo/semantics/publishedVersio

Synchrotron X-ray studies on polyamide composites prepared by reactive injection molding

Semicrystalline polyamide 6 (PA6) and composites on its basis are among the most frequently used polymer materials for highly demanding applications. The performance of these composites depends on the crystalline structure of the PA6 matrix in which two crystalline forms most frequently coexist: α- and γ-polymorphs. This work reports on the crystalline structure of a variety of composite materials produced by in-mold reactive polymerization of caprolactam in specially designed semi-automatic equipment for reactive processing of nylons (NYRIM), carried out in the presence of particulate mineral reinforcements (natural or-ganically treated aluminum silicates and synthetic titanosilicates), PA6 oriented monofilaments and textile structures of glass fibers. The morphology and the crystalline structure of all composites were studied by syn-chrotron X-ray diffraction. Transcrystalline PA6 layer was observed in all fibrous PA6 laminates whose struc-ture fine crystalline structure was accessed.Fundação para a Ciência e Tecnologia; German Synchrotorn Radiation Source - DESY, Hambur

Optimal control for an irrigation planning problem: characterisation of solution and validation of the numerical results

In a previous study, the authors developed the planning of the water used in the irrigation systems of a given farmland in order to ensure that the field cultivation is in a good state of preservation. This planning was modelled and tackled as an optimal control problem: minimize the water flow (control) so that the extent water amount in the soil (trajectory) fulfils the cultivation water requirements. In this paper, we characterize the solution of our problem guaranteeing the existence of the solution and applying the necessary and sufficient conditions of optimality. We validate the numerical results obtained previously, comparing the analytical and numerical solutions.PEst-OE/MAT/UI0013/2014 and PEST-C/FIS/UI607/2013, European Union FP7 (FP7-PEOPLE-2010-ITN, Grant Agreement no. 264735- SADCO), FCT projects PTDC/EEA-CRO/116014/2009 and PTDC/EEI-AUT/1450/201

Upregulation of tRNA-Ser-AGA-2-1 promotes malignant behavior in normal bronchial cells

Serine tRNAs (tRNASer) are frequently overexpressed in tumors and associated with poor prognosis and increased risk of recurrence in breast cancer. Impairment of tRNA biogenesis and abundance also impacts proteome homeostasis, and activates protein quality control systems. Herein, we aimed at testing whether increasing tRNASer abundance could foster tumor establishment through activation of the UPR. In order to do so, firstly we confirmed that the expression of tRNA-Ser-AGA-2-1 [hereafter tRNASer(AGA)] was upregulated by 1.79-fold in Stage I NSCLC tumors when compared to normal adjacent tissue. To study the impact of tRNASer(AGA) in early stage tumorigenesis, we induced its upregulation in a non-tumoral bronchial cell line, BEAS-2B. Upregulation of this tRNA increased cellular proliferation and protein synthesis rate, driven by eIF2α dephosphorylation and ATF4 activation downstream of PERK signaling. Futhermore, tRNASer(AGA) enhanced transformation potential in vitro, and promoted the establishment of slow growing tumors with aggressive features in nude mice. Our work highlights the importance of studying tRNA deregulation on early stage tumorigenesis, as they may be potential malignancy and aggressiveness biomarkers.publishe

Isomerisation of pinene oxide in the presence of an indenyl Molybdenum carbonyl complex

Trabalho apresentado 18th IUPAC International Symposium on Organometallic Chemistry Directed Towards Organic Synthesis, 28 june - 2 july 2015, Barcelona, Spaininfo:eu-repo/semantics/publishedVersio

New potential antitumoral di(hetero)arylether derivatives in the thieno[3,2-b]pyridine series : synthesis and fluorescence studies in solution and in nanoliposomes

New fluorescent methoxylated di(hetero)arylethers in the thieno[3,2-b]pyridine series were prepared by a copper-catalyzed Ullmann-type C-O coupling of the methyl 3-amino-6-bromothieno[3,2-b]pyridine-2-carboxylate with ortho, meta and para-methoxyphenols, using N,N-dimethylglycine as the ligand and Cs2CO3 as the base. The compounds obtained were tested for their inhibitory growth activity in three human tumor cell lines MCF-7 (breast adenocarcinoma), A375-C5 (melanoma), NCI-H460 (non-small cell lung cancer). The di(hetero)arylethers bearing a methoxy group in the ortho and meta positions showed very low GI50 values (1.1 - 2.5 µM) in all the three tumor cell lines. Their fluorescence properties in solution and when encapsulated in different nanoliposome formulations, composed either by egg-yolk phosphatidylcholine (Egg-PC), dipalmitoyl phosphatidylcholine (DPPC), dimyristoyl phosphatidylglycerol (DMPG), dioctadecyldimethylammonium bromide (DODAB), distearoyl phosphatidylcholine (DSPC), with or without cholesterol (Ch), or distearoyl phosphatidylethanolamine-(polyethylene glycol)2000 (DSPE-PEG), were studied. All compounds can be carried in the hydrophobic region of the liposome membrane. The liposomes with incorporated compounds are nanometric in size (diameter lower than 150 nm) and have generally low polydispersity.Fundação para a Ciência e a Tecnologia (FCT) - Bruker Avance III 400-Univ. Minho).Fundo Europeu de Desenvolvimento Regional (FEDER)Research Centres, CQ/UM - PEstC/QUI/UI0686/2011, FCOMP-01-0124-FEDER-022716)] and CFUM [PEst-C/FIS/UI0607/2011, F-COMP-01-0124-FEDER-022711)], PTDC/QUI/81238/2006, (FCOMP-01-0124-FEDER-007467) (photophysical studies), PTDC/QUI-QUI/111060/2009 (F-COMP-01-0124-FEDER-015603) (organic synthesis and biological studies)COMPETE/QREN/EU

Social support in people with chronic respiratory diseases: an exploratory study

Objectives: Social support influences health status and manage-ment of people with chronic respiratory diseases (CRDs), but it is largely unexplored. Thus, the aim of this study was to explore the quantity, quality and network composition of social support in peo-ple with CRDs.Methods: An exploratory cross-sectional study was conducted in people with CRDs. Quantity (number of people), quality (level of satisfaction) and network composition (who provides support) of social support were assessed with the 6-item short form Social Su-pport Questionnaire (SSQ6). For each item, participants were asked to provide two answers: i) to list all people or institutions who fit the description of the question (range: 0 to 9 people; quantity and network composition); and ii) to indicate how satisfied they were with the support these people or institutions provided (range: 1 very dissatisfied to 6 very satisfied; quality). Total score for quantity and quality was computed using the mean of the scores from the 6 items. Descriptive statistics was used, and values were presented as median, minimum and maximum or frequencies.Results: Forty-eight people with CRDs (chronic obstructive pulmo-nary disease [COPD] n = 39, asthma n = 4, interstitial lung disease [ILD] n = 4 and lung cancer n = 1; 70 [51-84] years old, 32 [66.7%] male) were included. Participants had a median quantity and quality of social support of 1.66 [0.67-7.67] people and 6 [3.5-6] points, respectively. Their support network was mainly composed by close relatives (i.e., spouse and children) in all items of SSQ6 (Table).Conclusions: People with CRDs seem to have low quantity of social support but perceive it as high quality. The network composition of social support seems to lack support from the community (e.g., neighbours and/or institutions) in this population.publishe

Gap-analysis and annotated reference library for supporting macroinvertebrate metabarcoding in Atlantic Iberia

DNA metabarcoding provides a rapid and effective identification tool of macroinvertebrate species. The accuracy of species-level assignment, and consequent taxonomic coverage, relies on comprehensive DNA barcode reference libraries, which, due to incompleteness, are currently a recognized limitation for metabarcoding applications. In this study, we assembled a comprehensive reference library of DNA barcodes for Atlantic Iberia marine macroinvertebrate species, assessed gaps in species coverage and examined data ambiguities. Initially, an Iberian species checklist for the three dominant groups of marine macroinvertebrates was compiled, comprising 2827 species (926 Annelida, 638 Crustacea and 1263 Mollusca). A total of 18162 DNA sequences of the cytochrome c oxidase subunit I barcode region (COI-5P) matching the species checklist were compiled in a BOLD dataset, where taxonomic discordances were evaluated and cases of deep intraspecific divergence flagged. Gap-analysis showed that 63% of the Iberian macroinvertebrate species still lack a DNA barcode. Coverage gaps varied considerably across taxonomic groups with Mollusca displaying the highest sequence representation in the dataset (427 species, 49% of the total number of sequences), and Crustacea the highest species coverage with 338 species barcoded (53% of the checklist). In contrast, Polychaeta displayed the lower levels of completion (288 species, 16% of the total number of sequences). In total, 1545 Barcode Index Numbers (BINs) were assigned to 1053 barcoded species, of which 66% were taxonomically concordant, 26% displayed multiple BINs and 8% were discordant. Overall, results show that there is still a large portion of marine invertebrate taxa in this region of Europe pending barcode coverage, even considering only the dominant groups. However, the most notable finding was the relevant proportion of species flagged for significant intraspecific divergence and possible hidden diversity. The annotated reference library and gap-analysis here provided can therefore contribute to prioritize marine macroinvertebrate taxa for future research efforts and barcode coverage.Fundação para a Ciência e a Tecnologia | Ref. UIDB/04050/2020Fundação para a Ciência e a Tecnologia | Ref. PD/BD/127994/2016Fundação para a Ciência e a Tecnologia | Ref. SFRH/BD/131527/201

An integrated in vitro approach unveils the biocompetence and glutathiolomic profile of a human hepatocyte-like cell 3d model

Funding: This work was supported by FCT (Portugal) through the research grant PTDC/MED-TOX/29183/2017. Acknowledgments: The authors thank ECBio S.A. for providing the hnMSCs and F.A. Beland (NCTR, Jefferson, AR, USA) for the kind donation of nevirapine. FCT (UID/DTP/04138/2019, UID/QUI/00100/2019, RECI/QEQ-MED/0330/2012, SFRH/BD/144130/2019 to J.S.R., SFRH/BD/110945/2015 to P.F.P. and CEECIND/02001/2017 to A.M.M.A) are also acknowledged.The need for competent in vitro liver models for toxicological assessment persists. The differentiation of stem cells into hepatocyte-like cells (HLC) has been adopted due to its human origin and availability. Our aim was to study the usefulness of an in vitro 3D model of mesenchymal stem cell-derived HLCs. 3D spheroids (3D-HLC) or monolayer (2D-HLC) cultures of HLCs were treated with the hepatotoxic drug nevirapine (NVP) for 3 and 10 days followed by analyses of Phase I and II metabolites, biotransformation enzymes and drug transporters involved in NVP disposition. To ascertain the toxic effects of NVP and its major metabolites, the changes in the glutathione net flux were also investigated. Phase I enzymes were induced in both systems yielding all known correspondent NVP metabolites. However, 3D-HLCs showed higher biocompetence in producing Phase II NVP metabolites and upregulating Phase II enzymes and MRP7. Accordingly, NVP-exposure led to decreased glutathione availability and alterations in the intracellular dynamics disfavoring free reduced glutathione and glutathionylated protein pools. Overall, these results demonstrate the adequacy of the 3D-HLC model for studying the bioactivation/metabolism of NVP representing a further step to unveil toxicity mechanisms associated with glutathione net flux changes.publishersversionpublishe